Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • 1985-1989  (398)
  • 1980-1984
  • 1988  (191)
  • 1985  (207)
  • pharmacokinetics  (216)
  • Nuclear reactions
  • Ultrastructure
Datenquelle
Materialart
Erscheinungszeitraum
  • 1985-1989  (398)
  • 1980-1984
Jahr
Schlagwörter
  • 101
    Digitale Medien
    Digitale Medien
    Clinical pharmacokinetics of clozapine in chronic schizophrenic patients (1988)
    Springer
    European journal of clinical pharmacology 34 (1988), S. 445-449 
    Details
    ISSN: 1432-1041
    Schlagwort(e): clozapine ; schizophrenics ; pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The clinical pharmacokinetics of clozapine, an atypical neuroleptic, was evaluated in 10 chronic schizophrenic male patients after intravenous and oral administration. The mean equilibrium-state concentration ratio between blood and plasma was experimentally determined to be 0.87. The average values for blood clearance, hepatic extraction ratio and oral bioavailability were 250 ml/min, 0.2 and 0.27, respectively. Plasma concentration peaked on average at 3 h. The mean volume of distribution at steady-state and the terminal half-life was 1.6 l/kg and 10.3 h, respectively. A large fraction of the dose is most probably metabolized by some extrahepatic presystemic routes. The large inter-individual variability in the bioavailability and clearance is probably the main reason for large variation in the steady-state plasma level in patients receiving the same oral dosage regimen.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01046700
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 102
    Digitale Medien
    Digitale Medien
    Relative bioavailability of oral low dose methotrexate (1988)
    Springer
    European journal of clinical pharmacology 34 (1988), S. 517-519 
    Details
    ISSN: 1432-1041
    Schlagwort(e): methotrexate ; pharmacokinetics ; oral low dose formulation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary In 39 patients the bioavailability of methotrexate from the two tablets Emthexat 2.5 mg and Methotrexate 2.5 mg was assessed in a double-blind study after a single oral dose of 30 mg/m2 Methotrexate. There was a considerable inter-individual variation of the serum pharmacokinetics in regard to Cmax and tmax, independent on the MTX formulation. Emthexat 2.5 mg tablets and Methotrexate 2.5 mg tablets were bioequivalent according to the definition (AUCE≥AUCM×80%).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01046713
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 103
    Digitale Medien
    Digitale Medien
    Dosage regimen of cimetidine reviewed. Possible drug accumulation after multiple oral doses (1988)
    Springer
    European journal of clinical pharmacology 34 (1988), S. 539-542 
    Details
    ISSN: 1432-1041
    Schlagwort(e): cimetidine ; dosage regimen ; multiple oral doses ; accumulation ; pharmacokinetics ; children
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The doses of cimetidine recommended differ in children, especially those with cystic fibrosis. These dosage regimens were derived from single-dose pharmacokinetic studies of the drug. Some authors showed, however, that after administration of repeated oral doses of cimetidine in healthy adults and children with cystic fibrosis, the elimination half-life of the drug was markedly prolonged. In view of the ability of cimetidine to inhibit metabolism of other drugs, it is suggested that the parent compound and/or its metabolite(s) may inhibit its own metabolism during a prolonged course of treatment. Enterohepatic recirculation of the drug and/or its metabolite(s) may also contribute to prolongation of its elimination. One should therefore be cautious in using single-dose pharmacokinetic parameters to calculate repeated dose regimens and expected plasma steady-state concentrations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00615214
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 104
    Digitale Medien
    Digitale Medien
    Use of mannitol during neurosurgery: Interpatient variability in the plasma and CSF levels (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 643-649 
    Details
    ISSN: 1432-1041
    Schlagwort(e): mannitol ; neurosurgery ; pharmacokinetics ; interpatient variability ; CSF kinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary An i.v. infusion of mannitol was given over 15 min to 12 patients before they underwent intracranial surgery under general anesthesia. Samples of blood, CSF and urine were taken over 4 h. Mannitol disappeared from plasma in a bi-exponential manner. The mean maximal plasma concentration was 4.08 mg/ml at 15 min, and at 4 h it had declined to 0.53 mg/ml. The mean distribution rate constant was 11.2 h−1, corresponding to a plasma distribution half-life of 0.11 h. The mean elimination rate constant was 0.41 h−1, the plasma half-life was 2.2 h, the central distribution volume was 16.31, and total plasma clearance was 100.4 ml/min. The mean concentration of mannitol in CSF during the 4 h period increased up to 0.10 mg/ml. There were marked interindividual differences in the concentration ratio blood/CSF, and the CSF concentration varied 7.5 fold between patients. Optimal use of mannitol during neurosurgery requires further prolonged study of its pharmacokinetics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00637601
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 105
    Digitale Medien
    Digitale Medien
    Dosage guidelines for the use of vancomycin based on its pharmacokinetics in infants (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 637-642 
    Details
    ISSN: 1432-1041
    Schlagwort(e): vancomycin ; pharmacokinetics ; dosage guidelines ; infants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The purpose of this study was to characterize the pharmacokinetics of vancomycin and to develop optimal dosage guidelines in infants. Thirteen infants between the ages of 13 to 183 days were enrolled. All had been born prematurely, and average gestational age, postconceptional age, and actual body weight were 29.8 weeks, 38.2 weeks, and 2.1 kg respectively. Multiple blood samples were obtained from each patient after 72 h of therapy. Serum inhibitory and bactericidal titres were determined for peak and trough samples. There were good correlations between total body clearance of vancomycin and both postconceptional age (r=0.86) and actual body weight (r=0.87). This information was used to develop vancomycin dosage guidelines in premature infants. The regression line for vancomycin daily dosage requirements vs postconceptional age may be useful for determining initial dosage recommendations. There were also good correlations between vancomycin serum concentrations and serum inhibitory and cidal titres. Peak and trough concentrations in the therapeutic range (peak, 25–35 µg/ml; trough, 5–10 µg/ml) corresponded to titres of ≥ 1:8 and 1:2 to 1:8 respectively. Based on these data we suggest the following dosage guidelines for vancomycin: 10 mg/kg 12 hourly for 30–34 weeks postconceptional age and 〈1.2 kg actual body weight; 10 mg/kg 8 hourly for 30–42 weeks postconceptional age and 〉1.2 kg actual body weight; 10 mg/kg 6 hourly for 〉42 weeks postconceptional age and 〉2.0 kg actual body weight. Thus, doses which are lower than currently recommended are needed for infants born prematurely. Furthermore, the initial dose of vancomycin can easily be determined using an infant's postconceptional age.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00637600
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 106
    Digitale Medien
    Digitale Medien
    4-quinolones inhibit biotransformation of caffeine (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 651-656 
    Details
    ISSN: 1432-1041
    Schlagwort(e): caffeine ; quinolones ; paraxanthine ; enoxacin ; ciprofloxacin ; pipemidic acid ; norfloxacin ; drug interaction ; pharmacokinetics ; drug metabolism ; ofloxacin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The pharmacokinetics of caffeine, including formation of its major metabolite paraxanthine in plasma, has been investigated in 12 healthy males (age 20–40 years) alone and during co-administration of the 4-quinolones ofloxacin, norfloxacin, pipemidic acid, ciprofloxacin, and enoxacin; ciprofloxacin and enoxacin were given in 3 different dose levels. The naphthyridine derivative enoxacin and the pyrido-pyrimidine derivative pipemidic acid had caused marked inhibition of caffeine and paraxanthine metabolism, whereas the genuine quinolone derivatives norfloxacin and ciprofloxacin had little effect, and the pyrido-benzoxacine derivative ofloxacin had no detectable effect. The different molecular and spatial structures of the compounds appear to be responsible for the differences in inhibitory potency.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00637602
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 107
    Digitale Medien
    Digitale Medien
    Creation of four consecutive instantaneous steady-state plasma concentration plateaus of theophylline and enprofylline by repeated infusions with exponentially decreasing delivery rates (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 657-661 
    Details
    ISSN: 1432-1041
    Schlagwort(e): theophylline ; enprofylline ; asthma ; pharmacokinetics ; intravenous infusion ; plateau levels
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Repeated exponentially decreasing influsions have been used to administer theophylline and enprofylline to show whether it would be feasible to create consecutive plasma concentration plateaus within a few hours. The infusions were carried out on two separate days in 8 stable asthmatics. Before the infusion experiments, the pharmacokinetics of the substances in the individual subjects were determined on a separate day. Plasma concentration rose to the desired level within 5 min after the start of the infusion at each dose level and a stable plasma concentration plateau was maintained during the following 90 min of the infusion. It was possible to achieve 4 subsequent concentration plateaus within a 6 h period. Use of this infusion method resulted in predictable plasma concentrations at all levels and so the method appears safe when the required plasma concentrations are below the toxic level. Apart from clinical situations where effective dosages of drugs must be administered rapidly, the method showed be useful in pharmacological dose-response studies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00637603
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 108
    Digitale Medien
    Digitale Medien
    Influence of repeated administration of cimetidine on the pharmacokinetics and pharmacodynamics of adinazolam in healthy subjects (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 59-64 
    Details
    ISSN: 1432-1041
    Schlagwort(e): adinazolam ; cimetidine ; pharmacokinetics ; pharmacodynamics ; healthy volunteers ; adverse effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Adinazolam is a new triazolobenzodiazepine bearing an alkyl-amino side chain. A cross-over double-blind placebo controlled study was carried out in 12 healthy volunteers, in order to check the possible interaction between cimetidine and adinazolam after repeated co-administration. Cimetidine or placebo were given during 17 days. Beginning on Day 8 of each treatment, adinazolam was given in the increasing doses following sequence of doses for 3 days: 10 mg b.i.d., 20 mg b.i.d. and 20 mg t.i.d. A pharmacokinetic and pharmacodynamic study was performed on the third day at each dose. A wash-out of three weeks was included between the two treatments. Cimetidine increased significantly the AUC values of both adinazolam and N-desmethyladinazolam, reduced the oral clearance of adinazolam, and prolonged adinazolam's half-life. The digit symbol substitution test was significantly affected at each dose level while the manual dexterity was marginally impaired by adinazolam plus cimetidine. Saftee-up interview and Clyde mood scale indicated an increased sedation under adinazolam plus cimetidine in four subjects.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00555508
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 109
    Digitale Medien
    Digitale Medien
    Do nizatidine and cimetidine interact with ibuprofen? (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 85-88 
    Details
    ISSN: 1432-1041
    Schlagwort(e): ibuprofen ; nizatidine ; cimetidine ; drug interaction ; pharmacokinetics ; healthy volunteers ; H2-antagonists
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The potential for interaction between ibuprofen and two histamine H2-receptor blocking drugs — nizatidine and cimetidine — was investigated in six healthy male volunteers aged 20 to 25 years. Each subject received placebo, nizatidine 300 mg and cimetidine 800 mg orally at 9.00 p.m. daily for six doses in three randomised treatment periods separated by eight days. On the third day of each treatment period ibuprofen 400 mg was administered at the same time and venous blood samples were taken at intervals throughout the night and subsequently up to 84 h after administration. There was no difference in the area under the plasma concentration-time curve, rate of absorption or half-life of elimination of ibuprofen between the three treatments. The elimination half-life of ibuprofen on placebo was 2.04 h. The elimination half-life of nizatidine on ibuprofen was 1.72 h and that of cimetidine was 3.54 h. The latter is higher than previously reported in normal subjects. It is concluded that neither H2-blocker affects the kinetics of ibuprofen in man.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00555513
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 110
    Digitale Medien
    Digitale Medien
    Pharmacokinetics of oxaprozin in women receiving conjugated estrogen (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 105-108 
    Details
    ISSN: 1432-1041
    Schlagwort(e): oxaprozin ; NSAIA ; conjugated estrogens ; drug interaction ; pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The kinetics of a single 1200 mg oral dose of oxaprozin, a nonsteroidal antiinflammatory agent of the propionic acid class, was studied in 22 healthy female volunteers aged 21 to 64 years. Eleven subjects had been taking a conjugated estrogen preparation for at least 3 months; the other 11 subjects served as control women who were not taking conjugated estrogens. Mean pharmacokinetic variables in control and conjugated estrogen groups were: volume of distribution, 15.1 vs 14.11; elimination half-life, 59.8 vs 54.2 h; clearance, 3.2 vs 3.1 ml/min; peak plasma concentration, 84.8 vs 90.7 µg/ml, respectively. None of the differences were significant. However, the time of peak concentration (8.9 vs 4.0 h) was significantly longer in the control group than in the conjugated estrogen group, respectively (p〈0.05). Oxaprozin clearance, accomplished by a combination of oxidation and conjugation, is unimpaired by coadministration of conjugated estrogens.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00555518
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 111
    Digitale Medien
    Digitale Medien
    Plasma and synovial fluid meclofenamic acid concentrations in patients with rheumatoid arthritis of the knee (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 199-202 
    Details
    ISSN: 1432-1041
    Schlagwort(e): meclofenamic acid ; synovial fluid ; rheumatoid arthritis ; pharmacokinetics ; protein binding
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary We have measured plasma and synovial fluid concentrations of meclofenamic acid at 2, 4, 8, and 12 h during steady-state administration (100 mg three times daily for 4–7 days). Paired plasma and synovial samples were obtained pre-treatment and at one of the above times in twelve patients with a diagnosis of rheumatoid arthritis. In addition, the extent of protein binding of meclofenamic acid was assessed in vitro in the pre-treatment plasma and synovial fluid specimens. Peak total concentrations of 1.73 and 0.86 µg·ml−1 were observed in plasma (at 2 h) and synovial fluid (at 4 h) respectively. The extent of protein binding was 99.7 and 99.6% (not significantly different) in plasma and synovial fluid respectively. The results of this study are compared to those from similar reported studies of other nonsteroidal anti-inflamatory compounds.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00609253
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 112
    Digitale Medien
    Digitale Medien
    Pharmacokinetics of pefloxacin and amikacin administered simultaneously to intensive care patients (1988)
    Springer
    European journal of clinical pharmacology 34 (1988), S. 637-643 
    Details
    ISSN: 1432-1041
    Schlagwort(e): pefloxacin ; amikacin ; pharmacokinetics ; drug interaction ; severe infections
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Ten adult patients with severe infections in an intensive care unit were treated simultaneously with 6 mg/kg pefloxacin and 7.5 mg/kg amikacin, infused i.v. over 1 h every 12 h for 5 days. Twelve h after the last infusion, pefloxacin alone was administered orally (400 mg tablet) every 12 h for 10 days. The pharmacokinetics of pefloxacin and its main metabolites, norfloxacin and pefloxacin N-oxide, were determined after the first (Day 1) and last (Day 5) infusions and after the last oral dose (Day 15). The kinetics of amikacin was determined after the first and the last infusion. The maximal and minimal steady-state plasma concentrations of amikacin were 27.3 and 3.3 mg/l. The total plasma clearance was 83.1 and 67.0 ml/min after the first and the last infusions, respectively, and the half-life was 3.9 and 5.0 h. The maximal and minimal steady-state plasma concentrations of pefloxacin were 13.1 and 7.9 mg/l after i.v. infusion and 13.4 and 9.0 mg/l after oral administration. Pefloxacin elimination (t1/2) increased from 11.3 h after the first infusion to 19.4 h after the last infusion and 21.1 h after the last oral dose. Total body clearance decreased from 90.8 (Day 1) to 51.9 (Day 5) and 56.4 ml/min (Day 15). The volume of distribution did not change significantly over the course of pefloxacin. Mean steady-state plasma concentrations of norfloxacin and pefloxacin N-oxide were respectively 0.5–0.6 mg/l and 0.9–1.3 mg/l after intravenous and oral administration of pefloxacin. There were no pharmacokinetic interaction between the drugs. The dosage regimen led to plasma concentrations of pefloxacin and amikacin within their therapeutic range.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00615230
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 113
    Digitale Medien
    Digitale Medien
    Digoxin-felodipine interaction in patients with congestive heart failure (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 461-465 
    Details
    ISSN: 1432-1041
    Schlagwort(e): digoxin ; felodipine ; pharmacokinetics ; drug interaction ; congestive heart failure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary A possible interaction between felodipine and digoxin was studied in 23 patients with congestive heart failure before and after 8 weeks treatment with both drugs. A modest, non-significant increase in serum digoxin level 2 h postdose (+15%) was found in the felodipine group (n=11) compared to placebo (n=12), with no change in the trough and 6 h postdose levels. There was a bimodal distribution of the observed changes in serum digoxin level 2 h postdose: a significant increase (p〈0.001) was observed only in patients with a high plasma felodipine level, which may have been caused by changes in the absorption rate in those patients. Changes in the elimination of digoxin after felodipine therapy appeared unlikely, since the trough and 6 h post-dose levels were unchanged. Analysis of the clinical characteristics, haemodynamics and laboratory values revealed no significant differences between the subgroups. The observed increase in serum digoxin warrants monitoring the trough and peak levels digoxin in patients with congestive heart failure who are also being treated with felodipine.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00558239
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 114
    Digitale Medien
    Digitale Medien
    The pharmacokinetics of oxybutynin in man (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 515-520 
    Details
    ISSN: 1432-1041
    Schlagwort(e): oxybutynin ; pharmacokinetics ; health volunteers ; debrisoquine ; genetic polymorphism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary We have studied the pharmacokinetics of oxybutynin (Ditropan) after single oral (5 mg) and intravenous administration (1 and 5 mg), and after repeated oral administration in healthy volunteers. Oxybutynin was rapidly absorbed, maximum plasma concentrations (8 ng·ml−1) being reached in less than 1 h. The absolute systemic availability averaged 6% and the tablet and solution forms displayed similar relative systemic availability. Plasma concentrations of oxybutynin fell biexponentially, the elimination half-life being about 2 h. There was a large interindividual variation in oxybutynin plasma concentrations. Almost no intact drug could be recovered in the urine. During repeated oral administration steady-state was reached after eight days of treatment. The low absolute systemic availability of oxybutynin, the large interindividual variability in its plasma concentrations, and the apparent absence of intact oxybutynin in the urine suggest that its major pathway of elimination is hepatic metabolism.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00558247
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 115
    Digitale Medien
    Digitale Medien
    Single and multiple dose pharmacokinetics of enteric coated ketoprofen: Effect of cimetidine (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 521-527 
    Details
    ISSN: 1432-1041
    Schlagwort(e): ketoprofen ; cimetidine ; enteric coated formulation ; pharmacokinetics ; co-administration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The effect of cimetidine on the single and multiple dose pharmacokinetics of enteric coated ketoprofen was studied in 12 healthy volunteers. Each subject completed two 8-day study treatment periods: either ketoprofen alone (100 mg p.o. twice daily), or co-administered with cimetidine (600 mg twice daily). tlag, Cmax, tmax, t1/2, and k for ketoprofen were not significantly different between single and multiple dose administration. AUC of ketoprofen was slightly but significantly larger following multiple (21.2 µg·h·ml−1) as compared to single dose administration (19.0 µg·h· ml−1). As a result, plasma clearance of ketoprofen was slightly but significantly reduced following multiple dose administration (80.6 ml/min vs 89.3 ml/min). Cimetidine had no effect on the single or multiple dose pharmacokinetics of enteric coated ketoprofen. Total 12-h urinary recovery of ketoprofen (mostly in the form of ketoprofen glucuronide) was 83.5% of the dose following single dose administration and was significantly greater following multiple dose administration (93.1%). Again cimetidine co-administration had no effect on the single and multiple dose urinary recovery. The results of this study show that cimetidine is not affecting the oral pharmacokinetics of enteric coated ketoprofen.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00558248
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 116
    Digitale Medien
    Digitale Medien
    Differential effect of food on kinetics of bromocriptine in a modified release capsule and a conventional formulation (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 535-541 
    Details
    ISSN: 1432-1041
    Schlagwort(e): bromocriptine ; pharmacokinetics ; food interaction ; modified release formulation ; prolactin inhibition ; pharmacodynamics ; side-effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The influence of food on release of drug from a modified release capsule of bromocriptine 5 mg (Parlodel SRO) and a conventional formulation of bromocriptine 5 mg has been studied in 8 healthy male volunteers. Both formulations produced objective and subjective effects, such as orthostatic reactions, nausea, dizziness, vomiting and nasal congestion. The modified release capsule caused fewer side-effects than the normal capsule. Both formulations had less cardiovascular effect in the fed than in the fasting state. There was no significant difference between the normal and the modified release capsules taken fasting or after a meal in terms of the AUC extrapolated to infinity. The relative bioavailability of the 5 mg modified release capsule was 84.6% of the normal capsule under fasting conditions and 107.5% after food. In contrast to the virtually unchanged extent of absorption, the rate of absorption was markedly affected by food, especially from the conventional capsule. The mean time of 50% absorption increased from 1.06 h (fasting) to 3.2 h (fed), whereas for the modified release capsule food mainly resulted in an increased lag time of absorption. The almost instantaneous dissolution of bromocriptine from the normal capsule in vitro (both in HCl and fasting human gastric juice) and the delay of absorption after a meal in vivo suggest that the rate limiting step in absorption of the normal capsules is delivery of released drug from the stomach to the small intestine, which is delayed by food. Both the modified release 5-mg capsule and the normal 5-mg capsule showed extended suppression of prolaction over 36 h, in all subjects, both fasted and after a meal.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00558250
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 117
    Digitale Medien
    Digitale Medien
    Inter- and intraindividual differences in oral chlorambucil pharmacokinetics (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 551-554 
    Details
    ISSN: 1432-1041
    Schlagwort(e): lymphocytic leukaemia ; chlorambucil ; phenylacetic acid mustard ; pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Inter- and intraindividual variation in the pharmacokinetics of oral chlorambucil was investigated in patients with chronic lymphocytic leukaemia. Five patients were given in randomized order 15, 40, 60 and 70 mg chlorambucil p.o. and plasma was analyzed for chlorambucil and its cytotoxic metabolite phenyl acetic acid mustard. The area under the plasma concentration-time curve of chlorambucil varied two- to fourfold between patients at each dose level. The AUC of the metabolite was higher and showed twofold interindividual variation. The intraindividual dose-corrected AUCcs also varied twofold. No dose dependency of the dose corrected AUC was seen either for chlorambucil or the metabolite. Elimination of both compounds form plasma was rapid, with half-lives of 1.01 and 1.94, respectively.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00558252
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 118
    Digitale Medien
    Digitale Medien
    Pharmacokinetics and tissue concentrations of ceftazidime in burn patients (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 543-549 
    Details
    ISSN: 1432-1041
    Schlagwort(e): ceftazidime ; pharmacokinetics ; tissue concentrations ; burn patients
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The pharmacokinetics and tissue concentrations of ceftazidime have been investigated in 8 patients with severe burns (20–80% of body surface area) undergoing skin transplantation 2 to 21 days after injury. Two prophylactic doses of ceftazidime were administered as 1 g i.v. bolus injections with an 8 h interval. Blood, urine, burn blister fluid and tissue were frequently sampled and drug concentrations were analyzed by HPLC. The kinetics of ceftazidime was the same after each dose. In these patients the pharmacokinetics of ceftazidime was greatly altered from that in other patients and there was much interindividual variation. The mean ceftazidime elimination half-life, apparent volume of distribution and total clearance were: 2.7 h, 30.91 (0.38 l·kg−1) and 139 ml·min−1, respectively. A linear correlation was found between creatinine clearance and the renal clearance of the ceftazidime, the mean values being 108 and 95 ml·min−1, respectively. No correlation was found between creatinine clearance and the total clearance of ceftazidime. The mean percentage urine recovery was 69% of the dose. Tissue and burn blister fluid concentrations were above the MIC, and ranged from 40.0 to 3.1 mg·kg−1. A substantial increase in the apparent volume of distribution and non-renal clearance of ceftazidime was observed, probably due to increased capillary permeability and drug loss through the wound surface replacement of prior to surgery and subsequently to lost and blood fluid.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00558251
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 119
    Digitale Medien
    Digitale Medien
    Influence of renal function on the elimination of morphine and morphine glucuronides (1988)
    Springer
    European journal of clinical pharmacology 34 (1988), S. 353-357 
    Details
    ISSN: 1432-1041
    Schlagwort(e): morphine ; morphine glucuronides ; renal function ; pharmacokinetics ; radioimmunoassay
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The influence of renal function, measured by 51Cr-EDTA clearance, on morphine and morphine glucuronide kinetics has been studied in 13 patients after a single i.v. injection of morphine. Unconjugated morphine and morphine glucuronides were measured by a sensitive, specific RIA after extraction from plasma. No significant correlation was found between total body clearance of unconjugated morphine and 51Cr-EDTA clearance. However, patients with renal insufficiency had impaired elimination of morphine glucuronides, and the apparent clearance was significantly correlated with the 51Cr-EDTA clearance (r=0.94, p〈0.001). A relatively long terminal elimination half-life of morphine was found in all patients (mean±SD: 9.2±2.5 h), irrespective of glomerular function.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00542435
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 120
    Digitale Medien
    Digitale Medien
    Differential effect of Type I and Type II diabetes on antipyrine disposition in man (1988)
    Springer
    European journal of clinical pharmacology 34 (1988), S. 369-375 
    Details
    ISSN: 1432-1041
    Schlagwort(e): diabetes mellitus ; antipyrine ; drug disposition ; pharmacokinetics ; Type I-/Type II diabetics ; cytochrome P-450
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary As the influence of diabetes on drug metabolism in patients is controversial, a study was performed to assess antipyrine (AP) disposition in controlled Type I and Type II diabetics and 2 age-and sex-matched control groups. In Type I diabetics, the half-life of AP was significantly reduced from 12.0 (controls) to 7.9 h, and the volume of distribution (V) was lowered from 733 to 569 ml·kg−1. The resulting plasma clearance and cumulative urinary excretion of AP and its metabolites over 24 h did not differ from controls. In Type II diabetics, the AP half-life (14.5 h) and V (568 ml·kg−1) did not differ from their age- and sex-matched controls (11.1 h and 643 ml·kg−1, respectively), but the plasma clearance of AP was significantly reduced by 30%, and urinary excretion was significantly reduced to 44% of controls. The differential effects of Types I and II diabetes on AP metabolism may explain, at least in part, the controversial data in the literature.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00542438
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 121
    Digitale Medien
    Digitale Medien
    Penbutolol: Pharmacokinetics, effect on exercise tachycardia, and in vitro inhibition of radioligand binding (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 613-623 
    Details
    ISSN: 1432-1041
    Schlagwort(e): penbutolol ; beta-adrenoceptor blockade ; pharmacokinetics ; pharmacodynamics ; in vitro/in vivo correlation ; radioreceptor assay ; active metabolites
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The pharmacokinetics of penbutolol 40 mg, its reduction in exercise-induced tachycardia, and the in vitro inhibition of radioligand binding to beta-adrenoceptors by plasma have been investigated in 7 healthy volunteers. The peak penbutolol concentration of 285 ng/ml was observed 1.2 h after administration, and the maximum of 4′-OH-penbutolol of 4.76 ng/ml was found after 1.64 h. Penbutolol was detected for up to 48 h, and 4′-OH-penbutolol dropped below the limit of detection after about 10 h. The terminal plasma concentration of penbutolol declined with an average half-life of 19 h. The maximum reduction in exercise-induced tachycardia was 33 beats/min 2.6 h after taking penbutolol. There was still a significant reduction of about 7 beats/min after 48 h. This effect could be adequately explained by the concentration-time course of penbutolol in combination with Clark's model of the concentration-effect relationship. Antagonist activity in plasma caused 91% inhibition of radioligand binding in vitro to beta2-adrenoceptors on rat reticulocyte membranes 1.6 h after intake of penbutolol. By 48 h after intake, radioligand binding was still significantly inhibited (23%). The in vitro inhibition of radioligand binding by plasma showed a linear correlation with the reduction in exercise-induced tachycardia for all phases of the workload. The time course of the reduction in heart rate was completely explained by the in vitro inhibition of radioligand binding. However, it was not possible to explain the in vitro inhibition of radioligand binding by the concentration-time course of penbutolol using a simple competition model, although both variables were based on the same sampling site. When the in vitro inhibition of radioligand binding was plotted against the penbutolol concentration at the same sampling times (with both variables transformed to multiples of the apparent inhibition constant) the discrepancy became even more apparent as time-related counterclockwise hysteresis. None of the known metabolites of penbutolol can explain the discrepancy between the penbutolol concentration and the inhibition of radioligand binding in vitro. It appears that an other active metabolite is formed, which contributes to the effect in vitro and in vivo and so can explain the observed discrepancy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00637597
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 122
    Digitale Medien
    Digitale Medien
    The pharmacokinetics of flutamide and its major metabolites after a single oral dose and during chronic treatment (1988)
    Springer
    European journal of clinical pharmacology 34 (1988), S. 633-636 
    Details
    ISSN: 1432-1041
    Schlagwort(e): flutamide ; prostate carcinoma ; 2-hydroxyflutamide ; pharmacokinetics ; antiandrogen ; first-pass metabolism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Flutamide is a nonsteroidal antiandrogen used in the treatment of prostatic carcinoma. We have investigated the disposition of flutamide and its two major metabolites in ten urological in-patients without significant liver or renal disease. After oral administration flutamide is absorbed from the gastrointestinal tract with a tmax of about 2 h. Flutamide undergoes extensive first-pass metabolism, and its major metabolites are 2-hydroxyflutamide and the hydrolysis product 3-trifluoromethyl-4-nitroaniline. After the oral administration of a single dose of 250 mg or 500 mg maximum flutamide plasma concentrations of 0.02 and 0.1 µg·ml−1 respectively were observed. Maximum plasma concentrations of 2-hydroxylfutamide for the same flutamide doses were 1.3 and 2.4 µg·ml−1 (mean ofn=2 orn=3). Steady-state concentrations of the biologically active metabolite 2-hydroxyflutamide (0.94±0.23 µg·ml−1, mean±SD,n=5) were found at 2–4 days after the administration of 250 mg every 8 h. The area under the plasma concentration time curve for 2-hydroxyflutamide averaged 11.4 (10.6 and 12.1) and 24.3 (21.5–29.4,n=3) µg·ml−1·h for 250 mg and 500 mg flutamide orally. 2-Hydroxyflutamide and 3-trifluoromethyl-4-nitroaniline were eliminated monoexponentially with half-times of 4.3–21.9 and 4.3–17.2 h (n=5) respectively.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00615229
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 123
    Digitale Medien
    Digitale Medien
    Multi-variate analysis of factors governing the pharmacokinetics of exogenous factor VIII in haemophiliacs (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 663-668 
    Details
    ISSN: 1432-1041
    Schlagwort(e): haemophilia-A ; factor VIII ; pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The pharmacokinetics of Factor VIII was evaluated by mathematical modeling in a large-scale study in 62 haemophilia-A subjects, in whom 137 plasma Factor VIII-time curves were measured during single dose (n=87) and repeated-dose (n=47) treatments for prophylaxis or minor bleeding episodes. The pharmacokinetic parameters [mean (SD)] estimated from single-dose curves were: clearance 3.85 ml·h−1·kg−1, volume of distribution 58.2 ml·kg−1, mean residence time 15.9 h. Parameters calculated from repeated-dose curves were: clearance 3.93 ml·h−1·kg−1, volume of distribution 61.8 ml·kg−1, and half-life 12.2 h. In patients with mild haemophilia, pharmaco-statistical analysis revealed that the endogenous synthesis of Factor VIII was constant and was not influenced by the administration of exogenous Factor VIII. The coefficient of variation for intra-individual variability of Factor VIII kinetics (estimated according to the Standard Two-Stage method) was 20.7% in single-dose curves and 23.2% in repeated-dose curves.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00637604
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 124
    Digitale Medien
    Digitale Medien
    A comparison of the pharmacokinetics of mefloquine in healthy Thai volunteers and in Thai patients with falciparum malaria (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 677-680 
    Details
    ISSN: 1432-1041
    Schlagwort(e): mefloquine ; falciparum malaria ; Thai subjects ; pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary We have studied the kinetics of a single oral dose of mefloquine (750 mg) in 12 Thai patients with falciparum malaria and have compared the results with those of a previous study in 12 healthy Thai volunteers [6]. All the patients responded to treatment with a mean parasite clearance time of 66.6 h and a mean fever clearance time of 54.1 h. There was no significant difference in peak plasma concentration, time to peak, area under the curve or apparent volume of distribution between patients and controls. However, the terminal half-life (t1/2) and mean residence time (MRT) were shorter in the patients (12.2 vs 16.7 days for t1/2 and 15.5 vs 21.4 days for MRT). We conclude that there are changes in the disposition of mefloquine related to malaria, although the exact basis of the changes is not clear.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00637607
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 125
    Digitale Medien
    Digitale Medien
    The relative systemic availability of ivermectin after administration as capsule, tablet, and oral solution (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 681-684 
    Details
    ISSN: 1432-1041
    Schlagwort(e): ivermectin ; bioavailability ; pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Administration of 12-mg doses of ivermectin (H2B1a) to 12 healthy volunteers in the form of tablets, capsules, and alcoholic oral solution showed the solution to have approximately twice the systemic availability as either of the solid forms, as evidence both by the maximum concentrations of drug attained in plasma and by the corresponding areas under the plasma concentration vs time curves. However, the two solid formulations showed similar systemic availability.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00637608
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 126
    Digitale Medien
    Digitale Medien
    Safety and pharmacokinetics of mifentidine after increasing oral doses in healthy subjects (1988)
    Springer
    European journal of clinical pharmacology 35 (1988), S. 673-676 
    Details
    ISSN: 1432-1041
    Schlagwort(e): mifentidine ; H2-antagonism ; pharmacokinetics ; half-life
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Eight healthy men were each given single oral doses of mifentidine 20, 40 and 80 mg, a new H2-receptor antagonist, in a four-way, double-blind, placebo-controlled, cross-over, dose-proportionality study. No significant objective or subjective effects were noted. Mifentidine showed unusual pharmacokinetic behaviour, producing a significant secondary peak in the drug concentration profile. The plasma AUC of mifentidine increased linearly with dose (r=0.983). The apparent plasma clearance was 38.11·h−1, 31.01·h−1, and 47.41·h−1 for the 20, 40 and 80 mg doses, respectively, and the corresponding terminal plasma half-lives were 10.3 h, 12.0 h, and 8.6 h. About 20% of the parent drug was excreted in urine over 24 h. The renal clearance (9.41/h for 20 mg, 9.5 l/h for 40 mg, and 12.8 l/h for 80 mg mifentidine) indicates that some of the drug was excreted by active tubular secretion. The results indicate that mifentidine is safe after single oral doses up to 80 mg. The pharmacokinetics of the 20 and 40 mg doses were similar, but after 80 mg the total body and renal clearances were significantly greater than after the two lower doses. As the terminal plasma half-life of mifentidine is longer than of other available H2-receptor antagonists, it may have clinical implications for once-a-day therapy of peptic ulcer diseases.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00637606
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 127
    Digitale Medien
    Digitale Medien
    Plasma drug and antiplatelet profiles of the original acetylsalicylic acid preparations used in the AMIS, PARIS and German-Austrian trials for secondary prevention of myocardial infarction (1988)
    Springer
    European journal of clinical pharmacology 33 (1988), S. 541-547 
    Details
    ISSN: 1432-1041
    Schlagwort(e): acetylsalicylic acid ; infarct prevention ; platelet aggregation ; pharmacokinetics ; healthy volunteers ; secondary heart attack prevention ; AMIS ; PARIS ; German-Austrian trials
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary In a cross-over study 6 healthy male subjects were given for 9 days the acetylsalicylic acid (ASA) preparations used in the Aspirin Myocardial Infarction Study (AMIS), Persantine-Aspirin Reinfarction Study (PARIS) and German-Austrian secondary heart attack prevention trials, exactly according to the original study protocols. Plasma concentrations of ASA and its main metabolites salicylic acid (SA) and salicyluric acid (SUA), as well as platelet function (collagen-induced platelet aggregation; tissue extract-induced change in platelet shape) were studied repeatedly on the first day of each medication period and were again examined on the sixth and ninth days. Differences in the plasma concentrations of ASA and its metabolites were found only on the first day, probably as a result of different absorption rates. Collagen-induced platelet aggregation was more rapidly inhibited the faster the preparation was absorbed. Each ASA preparation inhibited tissue extract-induced platelet shape change from the first dose, although statistically significant inhibition was seen only with the AMIS preparation. It is concluded that differences in the antithrombotic efficiency of ASA cannot be explained by differences in the pharmacokinetic and antiplatelet profiles of the various ASA preparations tested.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00542484
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 128
    Digitale Medien
    Digitale Medien
    Ultrastructural and cytochemical examination of the nuclear crystalloid inclusions of Olea europaea L. mesophyll cells (1988)
    Springer
    Trees 2 (1988), S. 261-266 
    Details
    ISSN: 1432-2285
    Schlagwort(e): Nuclear crystalloid inclusions ; Olea europaea ; Cytochemistry ; Ultrastructure ; Glycoprotein
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The nuclei of mesophyll cells of olive trees contain numerous sizeable crystalloid inclusions. Cytochemical examination using epoxy resin-embedded, semithin-sectioned tissue indicated the presence of proteins and oligoor polysaccharides in these inclusions. Their electron microscopical analysis revealed a crystalline substructure consisting of intersected subunits of high order. The spacing of the lattice fibrils and the angles of intersection were determined and used to establish a model of the unit cell of crystallization. It is suggested that the nuclear crystalloids of olive trees consist of glycoprotein molecules. They differ from the intranuclear crystalloids observed in other species predominantly in the high density of their subunit arrangement.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00202381
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 129
    Digitale Medien
    Digitale Medien
    Primary malignant astrocytoma of the cerebellum in children (1988)
    Springer
    Child's nervous system 4 (1988), S. 306-309 
    Details
    ISSN: 1433-0350
    Schlagwort(e): Malignant astrocytoma ; Glioblastoma ; Cerebellum ; Children ; Cytofluorometric DNA analysis ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The case of a 1-year-old girl with primary malignant astrocytoma of the cerebellum is presented with special reference to ultramicroscopic study and cytofluorometric DNA analysis. The routine light microscopic study was not pathognomonic because of the immaturity of the composing cells. The glial fibrillary microfilaments characteristic of astroglial cells were confirmed by means of electron microscopy. Cytofluorometrically, the DNA histogram of this case revealed a prominent peak in the 4C region, with considerable dispersion to the 8C region, indicating the polyploidic and heterogeneic pattern of malignant tumors.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00271931
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 130
    Digitale Medien
    Digitale Medien
    Effects of chronic diabetes mellitus on the electrical and contractile activities,45Ca2+ transport, fatty acid profiles and ultrastructure of isolated rat ventricular myocytes (1988)
    Springer
    Pflügers Archiv 411 (1988), S. 564-572 
    Details
    ISSN: 1432-2013
    Schlagwort(e): Isolated cardiac myocytes ; Electrical activity ; Contraction ; Fatty acids ; Ultrastructure ; Diabetes mellitus, experimental ; Streptozotocin ; Electrophysiology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The effects of chronic experimental diabetes on electrophysiological properties, contractile behavior,45Ca2+ transport, fatty acid profiles and ultrastructural characteristics were studied in enzymatically dissociated ventricular myocytes. Diabetes was induced in rats by streptozotocin administration and animals were killed 8–10 weeks later. Myocytes from diabetic rats exhibited electrical behavior similar to that of myocytes from control rats, but their contractile properties were altered. Their sensitivity of the twitch contractions to various positive and negative inotropic agents (isoproterenol, norepinephrine, phenylephrine, acetylcholine, ouabain and veratridine) was greatly diminished. However, a part of the contractile response (the tonic, sustained contractions) were increased in the diabetic myocytes, indicating that the changes are not caused by a decreased sensitivity of myofilaments. Furthermore, the diabetic myocytes exhibited also significant decrease in total Ca2+ content. The fatty acid profile in the diabetic group was changed mainly in that there were slightly elevated levels of docosahexaenoic acid and diminished levels of palmitic acid. The ultrastructure of the diabetic myocytes was affected only slightly. These investigations offer for the first time a comprehensive picture of changes related to diabetic cardiomyopathy as they occur at the level of cardiomyocytes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00582379
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 131
    Digitale Medien
    Digitale Medien
    Electron microscope localisation of insulin-like immunoreactivity of conventionally processed human insulinomas (1988)
    Springer
    Virchows Archiv 412 (1988), S. 443-450 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Insulin ; Insulinomas ; Ultrastructure ; Immunogold technique
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Localisation of insulin-like immunoreactivity has been studied using the immunogold staining procedure on thin sections of 6 human insulinomas, conventionally processed for electron microscopy. The labelling was restricted to the secretory granules. Depending on their morphology, these either resembled B-cell granules of human adult pancreas or belonged to the atypical (non-diagnostic) group. Within the former group, those with a crystalloid core or an amorphous dense or moderately dense core were strongly immunoreactive, whereas others, filled with a pale material, were poorly labelled. Most granules of this type were stored together within the heavily granulated cells of 3 insulinomas, presenting the classical features of clinical and biological behaviour and a typical light microscopic staining pattern. In contrast, the non-diagnostic granules, characterized by their smaller size, a very dense core and a thin halo, were mainly found within the poorly granulated cells making up the other tumours, and showed a very uneven labelling. Strongly labelled granules were found in one insulinoma that also belonged to the classical type; these were stored together with a few diagnostic granules within the same cells. Only poorly labelled atypical granules were present in two cases revealing a number of unusual features; these included moderate elevation of insulinaemia, uncertain tumour histology, as well as weak immunostaining for insulin/proinsulin and variable argyrophilia of the tumour in paraffin sections. These findings suggest that human insulinomas differ not only in storage capacity but also in their degree of granule maturation. This may involve some deficiency of either the prohormone conversion or the subsequent processing of the cleavage products.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00750578
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 132
    Digitale Medien
    Digitale Medien
    Lipid detection by malachite green-aldehyde in the dental basement membrane in the rat incisor (1988)
    Springer
    Cell & tissue research 253 (1988), S. 685-687 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Basement membrane ; Lipids ; Ultrastructure ; Rat (Sprague-Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Developing rat incisors were treated with malachite green-aldehyde fixative solution (MGA), which retains and stains lipids. We observed positive staining occurring as dots in the basement membrane. Most of these dots (2–3.5 nm in diameter) were grouped in the lamina densa but some were also present in the lamina lucida and the lamina fibroreticularis. These data provide evidence for the existence of lipids in the dental basement membrane and suggest that they are distributed together with the various groups of proteins so far detected.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00219762
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 133
    Digitale Medien
    Digitale Medien
    Catecholaminergic nerves in the embryonic chick ovary: co-localization with β2-adrenoceptor-bearing steroidogenic cells (1988)
    Springer
    Cell & tissue research 254 (1988), S. 1-9 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Adrenergic nerves ; Steroidogenic cells ; Embryonic ovary ; β 2Adrenoceptors ; Cytochemistry ; Ultrastructure ; Chicken
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The present study investigates the innervation of the embryonic chick ovary with regard to (i) development and compartmentalization of catecholaminergic nerves, and (ii) presence of adrenoceptors on steroidogenic target cells of catecholaminergic nerve terminals. Catecholaminergic nerve fibers visualized by glyoxylic acid-induced histofluorescence first appeared at embryonic day (E) 13. From E15 through E21 the density of fluorescent aminergic nerves increased markedly in parallel with the concentration of catecholamines and numbers of nerve bundles and single axons seen at the electron-microscopic level. Catecholaminergic nerves were confined to the ovarian medulla and closely associated with interstitial cells. Nerve terminals approached interstitial cells up to a distance of 20 nm and, in their majority, exhibited uptake of the false adrenergic transmitter 5-hydroxydopamine. Although adrenaline amounted to 14% of the total catecholamine content at E21, adrenaline immunoreactivity was only detected in adrenal chromaffin cells, but not in nerve fibers or cell bodies within the ovary. Interstitial cells structurally matured between E15 and E21 as documented by an increase of smooth endoplasmic reticulum and tubular mitochondria. Monoclonal antibodies mAB 120 and BRK 2 raised against avian β 1 and mammalian β 2-adrenergic receptors revealed the presence of β 2-adrenoceptor-like immunoreactivity on the surface of interstitial cells, but not on any other cell type. The results are consistent with the notion of a dense adrenergic innervation of the embryonic chick ovarian medulla and its steroidogenic interstitial cells, and suggest the chick ovary as an excellent model for elucidating the functional role of a neural input to steroidogenic cells during development.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220010
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 134
    Digitale Medien
    Digitale Medien
    The pattern of organization of intermediate filaments and their asymmetrical association with dense bodies in smooth muscle of an ascidian Halocynthia roretzi (1988)
    Springer
    Cell & tissue research 252 (1988), S. 23-32 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Smooth muscle ; Intermediate filaments ; Dual network ; Ultrastructure ; Ascidian ; Halocynthia roretzi
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary An extensive network of intermediate filaments that interconnected cytoplasmic dense bodies and connected the dense bodies to the cell surface was revealed in double-fixed, tannic acid-stained preparations of ascidian smooth muscle. The filament network ran through spaces in the continuous network of myofibrils, connecting them longitudinally, obliquely and transversely to form an intimately associated, dual network. In their transverse passage, the intermediate filaments ran across myofibrils along I-zones exclusively, interconnecting successive dense bodies. The pattern of attachment of intermediate filaments to dense bodies was predominantly “one-sided.” The filaments, which themselves were not incorporated into the contractile apparatus, remained folded or unfolded between myofibrils and between sarcomere-like structures in synchrony with the contraction-relaxation cycles. These results suggest that the intermediate filaments mechanically maintain the organization and arrangement of myofibrils via an intimate association with the myofibrils in the regions of the dense bodies, in such a way that the filaments do not impede muscle function. Based on these observations, a new model for the network of intermediate filaments in smooth muscle cells is proposed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213822
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 135
    Digitale Medien
    Digitale Medien
    Ultrastructure of the tentacles of the apodous holothurian Leptosynapta spp (Holothurioidea: Echinodermata) with special reference to the epidermis and surface coats (1988)
    Springer
    Cell & tissue research 251 (1988), S. 387-397 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Tentacles ; Ultrastructure ; Adhesion ; Leptosynapta spp (Holotheorie) ; Echinodermata
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The tentacles of the apodous holothurian Genus Leptosynapta have been studied by use of transmission and scanning electron microscopy. The gross anatomy, water vascular system, fibre systems and ectoneural nerve ring are described. A fuzzy coat of attenuated filaments covers the surface of the tentacle, broken only by secretory ducts. A cuticle underlies the fuzzy coat. Bacteria are common in the subcuticular space. Fixation without osmium gives poor preservation of the surface coats. The epidermis consists of a single layer of columnar cells consisting of Type-1, Type-2, support, goblet and uniciliated cells. Type-1 cells secrete electron-dense material and appear to be homologous to adhesive cells of the tentacles of other holothurians. The support cells contain large, granular vesicles not found in other holothurians. Goblet cells contain flocculent mucus and have an apical cilium. Goblet cells are not found in other holothurian tentacles and may function to lubricate and wrap adhering particles to aid their ingestion. The uniciliated cells are rare, poorly developed and the cilium does not extend past the cuticle. The ultrastructure of the tentacles is discussed in relation to those of other holothurians.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215848
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 136
    Digitale Medien
    Digitale Medien
    The ultrastructure of the lung of two newborn marsupial species, the northern native cat, Dasyurus hallucatus, and the brushtail possum, Trichosurus vulpecula (1988)
    Springer
    Cell & tissue research 252 (1988), S. 683-685 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Lung ; Ultrastructure ; Marsupial ; Newborn ; Surfactant ; Dasyurus hallucatus, Trichosurus vulpecula
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The lungs of newborn northern native cats, Dasyurus hallucatus and newborn brushtail possums, Trichosurus vulpecula were examined by both light and electron microscopy. The native cat has a birth weight of 18 mg after a gestation of about 21 days, whereas the brushtail possum weights 200 mg at birth and has a gestation period of 17.5 days. The lungs of the native cat are two large respiratory sacs, with a respiratory lining of squamous cells and surfactant-secreting cells. The capillaries are located within the connective tissue just below this respiratory epithelium. The visceral covering of the lung is formed by squamous cells. The lungs of the possum are composed of numerous large respiratory sacs which are separated by connective tissue septa in which the capillaries are located. The sacs, as in other species, are lined with squamous cells and surfactant secreting cells. It is proposed that the structure of the lung of the newborn marsupial is related more to the size of the newborn rather than to the length of the gestation period.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216657
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 137
    Digitale Medien
    Digitale Medien
    Vascular response in a non-uterine site to implantation-stage embryos in the rat and guinea-pig: in vivo and ultrastructural studies (1988)
    Springer
    Cell & tissue research 254 (1988), S. 217-224 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Implantation ; Embryo ; Ultrastructure ; Vasculature ; Rat (Sprague-Dawley) ; Guinea pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Preimplantation-stage embryos were transferred to the anterior eye chamber of recipient rats and guinea-pigs. After implantation had occurred the influence of the embryo on the iris vasculature was examined ultrastructurally. In both species, the earliest effect of embryonic implantation was an increased stromal oedema. Under increasing embryonic influence the vascular endothelial cells showed an increased number of projections into the vascular lumen, while in the rat, endothelial projections were also found pushing back into the basement membrane. In the rat, the endothelium became very irregular in thickness prior to complete disintegration and loss during more advanced stages of implantation. Rat embryonic trophoblast was found invading iris vasculature, particularly in areas where the iridial endothelium was partially or completely missing. Other cells in the iris, including the stroma, appeared to be less affected. In the guinea-pig, however, trophoblast cells appeared to be capable of invading the vasculature by displacing endothelial cells that still appeared morphologically normal.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220037
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 138
    Digitale Medien
    Digitale Medien
    Morphological, histochemical, and ultrastructural characterization of the accessory cells of neuromasts in the salamander Pleurodeles waltlii (1988)
    Springer
    Cell & tissue research 254 (1988), S. 233-240 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Lateral-line sense organs ; Mechanoreceptors ; Supporting cells ; Ultrastructure ; Pleurodeles waltlii (Urodela)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructural and histochemical features of the accessory cells of the neuromast of the salamander P. waltlii have been examined. Three types of accessory cells, supporting, mantle, and basal, were found, but only the first 2 are considered in this article. Supporting cells characterized by a highly dilated endoplasmic reticulum occur among and surrounding sensory cells. Mantle cells, morphologically different from the supporting cells, surround the remainder of the neuromast. Both types of accessory cells exhibit histochemically different secretory materials. Our morphological results suggest that both accessory cells contribute to the formation of cupular material.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220039
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 139
    Digitale Medien
    Digitale Medien
    Influence of a short light pulse at night on the ultrastructure of the rat pinealocyte: a quantitative study (1988)
    Springer
    Cell & tissue research 254 (1988), S. 247-249 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pinealocyte ; Light exposure ; Ultrastructure ; Rat (Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Although it is generally known that light strongly influences N-acetyltransferase activity and melatonin production in the pineal gland, little information is available concerning morphological changes following light exposure. As exposure of rats to a short light pulse at night rapidly depresses melatonin synthesis, we decided to determine whether this experimental condition produces rapid changes in the pinealocyte organelles. A 30-min light pulse at night (six hours after lights out) provoked rapid changes in the relative volumes of some pinealocyte organelles. The volume fractions of mitochondria, Golgi apparatus and lipid droplets, and the numbers of dense-core vesicles and “synaptic” ribbons decreased, whereas the volume fraction of lysosomes increased. There were no differences in the volumes of granular endoplasmic reticulum and vacuoles containing flocculent material in those animals exposed to light compared with control animals. These results indicate that a short light pulse at night causes ultrastructural changes that can be interpreted as morphological features of diminished activity of pinealocytes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220041
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 140
    Digitale Medien
    Digitale Medien
    Neurosecretory centers from the eyestalk of Siriella armata M. Edw. (Crustacea: Mysidacea): ultrastructural variations during normal and experimentally inhibited molt cycle (1988)
    Springer
    Cell & tissue research 254 (1988), S. 381-391 
    Details
    ISSN: 1432-0878
    Schlagwort(e): X-organ ; Sinus gland ; Ultrastructure ; Cyclic activity ; Siriella armata (Crustacea)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of the medulla interna-medulla externa X-organ (MI-ME Xo)-sinus gland (SG) complex in the eyestalk of Siriella armata is described during the normal and the experimentally inhibited molt cycle. In the normal SG, four types of neurosecretory axon terminals, each containing distinguishable neurosecretory granules, can be described. Thus, type-2 granules are synthesized by G1 neurons forming the MI-ME Xo. The cell bodies and axonal endings of these cells in the sinus gland have been examined at the following molt stages: intermolt (stage C4), premolt (D0 and D2), and postmolt (A1, A2 and B). Changes in ultrastructure of the G1 cells have been monitored and correlated to inhibitions of the molt-and reproductive cycle produced by electrocauterization of the MI-ME Xo. The results obtained suggest that the neurosecretion from the G1 cells exerts a positive influence on molt and brood preparation. The occurrence of a distal group of G1 cells whose axons terminate at a different site from the SG suggests that the neural factors of the MI-ME Xo are diverse and control different physiological activities.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00225810
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 141
    Digitale Medien
    Digitale Medien
    Study of neuropeptide Y-containing nerve fibers in the human penis (1988)
    Springer
    Cell & tissue research 254 (1988), S. 69-74 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Neuropeptide Y (NPY) ; Penis erection ; Perivascular nerve fibers immunocytochemistry ; Ultrastructure ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Neuropeptide Y 1–36 (IR-NPY) immunoreactive nerve-fiber processes have been observed in tunicae of veins and arteries and in smooth muscles of the human penis taken at autopsy or during surgery by use of light-and electron-microscopic immunohistochemical techniques. Numerous IR-NPY nerve fibers were mostly concentrated in the inner part of the adventitia close to the media of the arterial and venous vessels and among the intracavernous smooth muscle cells. IR-NPY nerve fibers were less abundant in veins than in arteries. Positive somata were not observed in the penises. At the ultrastructural level, IR-NPY were localized exclusively in large, dense granules of nerve terminals by means of the postembedding immunogold technique. In the deep dorsal vein, IR-NPY nerve fibers were also located in the media formed by an outer circular and an inner longitudinal layer. In the intracavernous and dorsal arteries, they showed the highest density in the inner part of the adventitia. In the corpora cavernosa and in the corpus spongiosum, IR-NPY nerve processes were intermingled between the smooth-muscle fibers around the sinusoid spaces. IR-NPY nerve fibers were present in the cavernous nerves close to the central arteries. The urethra did not show any IR-NPY-positive nerve fibers. This peculiar distribution of IR-NPY nerve fibers suggested that they could participate in regulating arterial and venous blood flow and intracavernous smooth-muscle tone. NPY may therefore be of importance in some of the mechanisms of penile erection especially during detumescence.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220018
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 142
    Digitale Medien
    Digitale Medien
    Implantation of cultured thymic fragments in congenitally athymic (nude) rats (1988)
    Springer
    Cell & tissue research 254 (1988), S. 283-294 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Thymus ; Cultured thymic fragments ; Epithelial cells ; Microenvironment ; Ultrastructure ; Rat (nude)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Cultured thymic fragments correspond to the thymic microenvironment depleted of lymphocytes and dendritic cells. When these fragments are implanted under the kidney capsule of congenitally athymic rats, lymphocytes and dendritic cells of host origin enter the graft and induce thymus-dependent immunity in the recipient. This paper describes the ultrastructure of the fragments and the changes that occur during the restoration of normal thymic architecture. At the end of the culture period of 6–9 days and in the early stages after implantation, the grafts consist of keratin-containing epithelial cells of unusual morphology that can be labelled with antibodies raised against the epithelium of the mid/deep cortex and the subcapsule/medulla. Normal thymic architecture develops, including nerves and blood vessels, as lymphocytes populate the environment, and by 4–6 weeks the epithelial cells are the same phenotypically and ultrastructurally as those found in normal rat thymus. However, some areas without lymphocytes still contain the atypical epithelial cells seen before implantation. Large multinucleated giant cells are also present with a few associated epithelial cells of subcapsular/medullary phenotype. In conclusion, the cultured thymic fragments contain a hitherto unknown precursor epithelial cell with an atypical ultrastructure and phenotype that is not seen in normal development.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00225801
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 143
    Digitale Medien
    Digitale Medien
    An ultrastructural study of mitosis and cytokinesis in normal ‘resting’ human breast (1988)
    Springer
    Cell & tissue research 252 (1988), S. 581-587 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Normal resting breast ; Ultrastructure ; Mitosis ; Cytokinesis ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The parenchyma of the normal “resting” human breast was examined by electron microscopy to characterize the cells undergoing mitosis and the mechanism by which the normal tissue architecture is maintained during this process. In this study of 112 mitotic cells, it was found that the mitotic cells were luminally positioned, polarised epithelial cells with no evidence of myoepithelial cell division. Ultrastructurally, the nuclear and cytoplasmic changes were consistent with previous reports of mitosis in other tissues. However, unlike all previous reports, two specific orientations of the nuclear spindle and thus the planes of cytokinesis were observed. In a few cases the spindle formed parallel to the lumen and division resulted in two luminally positioned daughter cells. However, in the majority of mitotic cells the spindle was approximately at right angles to the lumen and this orientation resulted in a luminally and a basally positioned daughter cell. It is proposed that the abnormally positioned basal daughter cell could develop into a myoepithelial cell or undergo deletion (apoptosis). Thus the two orientations of mitosis may explain the mechanism by which the epithelial and myoepithelial cell populations were maintained by a single progenitor cell without disrupting the integrity of the tissue architecture.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216645
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 144
    Digitale Medien
    Digitale Medien
    Ultrastructure of the ovarian medulla in the newly hatched chick treated with human chorionic gonadotropin (1988)
    Springer
    Cell & tissue research 253 (1988), S. 665-670 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Ovary ; Steroid-secreting cells ; Ultrastructure ; Chorionic gonadotropin ; Chicken
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructural characteristics of the ovarian medulla of the newly hatched white leghorn chick were studied in control animals and compared with chicks that were treated with human chorionic gonadotropin during embryonic development. The ovarian medulla was mainly occupied by epithelial cells which formed cords or islets surrounded by a basal lamina. Within this epithelial compartment, steroidogenic cells, poorly differentiated cells and a lacunary system could be recognized. When chicks were treated with human chorionic gonadotropin, steroidogenic cells became discernible; there was an increment in the amount of cytoplasm and the area of mitochondria. Poorly differentiated cells exhibited signs of stimulation, and transitional images suggested the transformation of these cells into steroidogenic cells. The epithelial cells of the lacunar system also displayed stimulated cytoplasmic organelles. Evidence was supplied suggesting that relatively undifferentiated cells persist in the ovarian medulla until hatching and can develop into steroidogenic cells under gonadotropic stimulation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00219758
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 145
    Digitale Medien
    Digitale Medien
    Electron-microscopic immunocytochemistry of 5-hydroxytryptamine in the ascidian endostyle (1988)
    Springer
    Cell & tissue research 253 (1988), S. 137-143 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Endostyle ; Ultrastructure ; Immunocytochemistry ; 5-Hydroxytryptamine ; Granules ; Ciona intestinalis ; Corella parallelogramma, (Tunicata) ; Ascidia mentula (Tunicata)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The cellular and subcellular distribution of serotonin (5-hydroxytryptamine, 5-HT) in the endostyle of three species of ascidians, Ciona intestinalis, Corella parallelogramma, Ascidia mentula, was studied by light-(immunoperoxidase) and electron-microscopic (immunogold) immunocytochemistry. At the light-microscopic level 5-HT-like immunoreactivity (5-HT-LI) was exclusively found in cells located in the lateral portion of the endostyle, between zone 7, known to have iodinating capacity, and zone 8, which consists of ciliated cells. At the electron-microscopic level, the 5-HT-immunoreactive cells were found to correspond to cells containing polymorphous, dense granules, 100–300 nm in diameter. The granules were located in the supranuclear cytoplasm facing the endostyle lumen as well as in the infranuclear cytoplasm facing the extracellular space. Quantification showed that the 5-HT-LI was considerably higher (13–67 times) in cytoplasmic areas containing granules as compared to areas devoid of granules. Most, but not all, of the 5-HT-LI was associated with the dense core of the granules. In conclusion, serotonin-containing cells are located in the peripheral portion of the endostyle, between zones 7 and 8. Serotonin is stored in cytoplasmic granules that are present both in the apical and basal cytoplasm. This suggests the possibility that the cells are bipolar and secrete serotonin both in a basal direction to the extracellular space, and in an apical direction to the pharyngeal lumen.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00221748
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 146
    Digitale Medien
    Digitale Medien
    Effect of live and heat-killed bacteria on the secretory activity of Paneth cells in germ-free mice (1988)
    Springer
    Cell & tissue research 251 (1988), S. 87-93 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Paneth cells ; Ultrastructure ; Morphometry ; Facultative anaerobes ; Germ-free mice
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Germ-free mice were given live or heat-killed facultative anaerobes, and the ultrastructure of ileal Paneth cells was quantitatively examined with special reference to secretory granules showing a bipartite substructure (central core and peripheral halo). After administering live or heatkilled bacteria, there was a decrease in the area occupied by the cores of secretory granules in Paneth cells, and exocytosed core material was observed in the crypt lumen. There were no changes in the area occupied by the halo of secretory granules. None of the examined Paneth cells phagocytosed bacteria. It is concluded that certain bacteria may affect the secretion of antibacterial agents contained in the secretory granules of Paneth cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215451
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 147
    Digitale Medien
    Digitale Medien
    Three-dimensional organization of the plasmalemmal vesicular system in directly frozen capillaries of the rete mirabile in the swim bladder of the eel (1988)
    Springer
    Cell & tissue research 254 (1988), S. 17-24 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Endothelium ; Swim bladder ; Capillaries ; Vesicles ; Ultrastructure ; Cryofixation ; Anguilla rostrata (Teleostei)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Several recent studies comparing chemically fixed and cryofixed endothelium have indicated that glutaraldehyde fixation may result in increases in the population of “vesicles” in the cytoplasm. Other reports based on ultrathin serial-section reconstruction of chemically fixed endothelium have revealed that the vesicular system is comprised of interconnected membranous compartments, which are ultimately continuous with either cell surface but do not extend across the endothelial cell. In this study, we have investigated the three-dimensional organization of the vesicular system in directly frozen, freeze-substituted capillaries of the rete mirabile from the swim bladder of the eel, specifically using the same block of embedded capillaries in which frozen capillaries had previously been found to contain less “vesicles” than chemically fixed capillaries. The results show that essentially all vesicles remain inter-connected with each other and are part of two separate sets of invaginations from the luminal and abluminal cell surface like in chemically fixed tissue. Any increase in vesicle number resulting from glutaraldehyde fixation does not affect the overall three-dimensional organization of the vesicular system in these endothelial cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220012
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 148
    Digitale Medien
    Digitale Medien
    Changes in proteins synthesized by rabbit endometrial epithelial cells following primary culture (1988)
    Springer
    Cell & tissue research 252 (1988), S. 123-132 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Uterine epithelium ; Cell culture ; Proteins ; Ultrastructure ; Rabbit
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Morphological and biochemical changes occurring in rabbit endometrial epithelial cells when placed in culture were investigated. Cells were examined by scanning- and transmission electron microscopy and freeze-fracture. Morphologically, cultured cells are shorter and broader than the columnar epithelial cells in vivo, but retain their polarity as indicated by the presence of apical microvilli and a well-developed junctional belt. To study changes in biochemical function, proteins synthesized by cells in primary culture were analyzed by two-dimensional gel electrophoresis. Proteins were labeled during a 24-h incubation with 35S-methionine and gels examined by fluorography. The pattern of proteins changed after cells had been in culture for 48 h. On day 3 new proteins were synthesized and several protein species labeled during days 1 or 2 of culture, including uteroglobin, no longer appeared. On days 3–8 of culture the protein patterns were similar. Addition of progesterone, estradiol, prolactin, or combinations of these hormones to the culture medium for 24–144 h failed to elicit consistent changes in the pattern of labeled proteins established after 3 days of culture. Minor differences in protein patterns among unrelated cultures appear to have been derived from the original cells of the culture. These results indicate that after 48 h in primary culture, cells grown in vitro resemble endometrial epithelial cells morphologically, but no longer reflect functionally the character of epithelial cells in the uterus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213833
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 149
    Digitale Medien
    Digitale Medien
    Formation of desmosomes and other contact specializations in cultured skin of the frog (Rana esculenta) (1988)
    Springer
    Cell & tissue research 252 (1988), S. 157-163 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Frog skin culture ; Desmogenesis ; Interdigitations ; Lamellipodia ; Ultrastructure ; Rana esculenta
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Small trypsinized explants from ventral skin of frogs (Rana esculenta) were maintained in culture for 4 days during which a newly formed epithelium differentiated along the cut edges of the dermis. During the first 6 h adjacent cells produced numerous interdigitating lamellipodia. After 2 days, epithelial polarity was restored by the formation of zonulae occludentes and the epithelial cells were joined by a few small newly formed desmosomes and by numerous interdigitations. Bipartite junctional complexes consisting of a zonula occludens, followed by a series of typical desmosomes, and characteristic of adult frog epidermis were formed only after 4 days. When cultured in the presence of an inhibitor of protein synthesis (cycloheximide) the trypsinized epidermis no longer formed desmosomes. Therefore pools of one or more crucial desmosomal proteins must be very low or non-existent. However, cycloheximide did not prevent the formation of cell contact specializations, consisting of a highly developed system of complex lamellar interdigitations, between adjacent cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213837
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 150
    Digitale Medien
    Digitale Medien
    Morphology of smooth muscle cells in the rat thoracic duct (1988)
    Springer
    Cell & tissue research 251 (1988), S. 243-248 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Thoracic duct ; Smooth muscle cell ; Ultrastructure ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The three-dimensional cytoarchitecture and ultrastructure of the smooth muscle cells in the wall of the rat thoracic duct were investigated by scanning and transmission electron microscopy. The muscle layer basically consists of a single layer of circularly arranged cells. The smooth muscle cell is fusiform or ribbon-like in shape, as in veins or venules with a similar or smaller diameter. Connections by spinous processes are observed between adjacent muscle cells along their length. Spot-like membrane contacts frequently occur in areas where facing membranes are closely apposed. These are thought to be gap junctions and may be responsible for electrical coupling and mechanical attachment. Large invaginations arranged regularly in rows on the surface of the smooth muscle cells can be observed. These invaginations are closely associated with a flattened sarcoplasmic reticulum, and caveolae tend to open into the invaginations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215831
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 151
    Digitale Medien
    Digitale Medien
    Atropine inhibits the degranulation of Paneth cells in ex-germ-free mice (1988)
    Springer
    Cell & tissue research 253 (1988), S. 397-402 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Paneth cells ; Ultrastructure ; Morphometry ; Atropine ; Germ-free/Ex-germ-free ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Previous studies have shown that the secretory products of Paneth cells contain antibacterial agents (lysozyme, IgA) that are affected by the bacterial milieu in the intestine. To investigate whether Paneth-cell secretion is controlled via cholinergic mechanisms, the ultrastructure of Paneth cells was studied in four animal groups: (1) germfree (GF) control mice (Jcl: ICR [GN], male, 13 weeks old), (2) GF mice injected subcutaneously with atropine sulfate (200 mg/kg body weight, dissolved in physiological saline 20 mg/ml), (3) ex-GF mice inoculated with feces from specific-pathogen-free (SPF) mice, and (4) ex-GF mice injected with atropine and inoculated with feces from SPF mice. In ex-GF mice inoculated with feces, 70–90% of the Paneth cells showed fewer secretory granules than those from GF mice (p〈0.01). Approximately 30% of the Paneth cells had a large vacuole (3–10 μm diameter) in the apical cytoplasm. Exocytosed electron-dense material from secretory granules was observed in a few crypt lumens. In ex-GF mice inoculated with feces and given atropine, about 90% of the Paneth cells contained numerous secretory granules, like those in GF control mice, but vacuolated Paneth cells and exocytotic figures were rare; thus the secretion of Paneth cells was blocked by atropine. It is therefore possible that the bacterial milieu in the intestine affects the secretory activity of Paneth cells via cholinergic mechanisms.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00222296
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 152
    Digitale Medien
    Digitale Medien
    Lymphocytes of the intestinal mucosa of chickens (1988)
    Springer
    Cell & tissue research 251 (1988), S. 189-195 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Lymphocytes ; Epithelium ; Mast cells ; Granular leukocytes ; Basophils ; Ultrastructure ; Chicken
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Examination, by light and electron microscopy, of the morphology and the staining properties of intraepithelial lymphocytes from the intestine of the chicken revealed a population of lymphoid cells, of which a proportion (up to 20%) is granulated. The majority of cells were immunoreactive with anti-T cell serum and can therefore be considered to be related to T-lymphocytes, but they did not proliferate when cultured with phytohaemagglutinin. The granulated cells were identical to those previously designated globule-containing leukocytes, but were distinct from mast cells in their morphology, staining reactions and the stability of the granules in different fixatives and buffers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215464
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 153
    Digitale Medien
    Digitale Medien
    Structural changes produced in Kupffer cells in the rat liver by injection of lipopolysaccharide (1988)
    Springer
    Cell & tissue research 251 (1988), S. 205-214 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Kupffer cells ; Granulocytes ; Ultrastructure ; Lipopolysaccharide ; Liver ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The fine structure of Kupffer cells has been studied at various times after an intravenous injection of lipopolysaccharide of Salmonella abortus equii. The most prominent effects were: an increase in the number and dimensions of phagocytic vacuoles (often containing ingested LPS and neutrophilic granulocytes); mitochondrial damage, including disintegration of the matrix and cristae; an increase in the amount of dilated, lucent rough endoplasmic reticulum; presence of fat droplets in the cytoplasm. Five days after injection of lipopolysaccharide, the Kupffer cells had resumed their normal ultrastructure. Several minutes after injection of lipopolysaccharide, platelets adhered to the Kupffer and endothelial cells. Between one and six hours, neutrophilic granulocytes accumulated in the liver sinusoids. The resulting obstruction of the hepatic microcirculation most probably affected cellular ultrastructure by ischaemia. At three days, the number of Kupffer cells was doubled, and increased further at later time intervals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215466
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 154
    Digitale Medien
    Digitale Medien
    Melanophore death and disappearance produces color metamorphosis in the polychromatic Midas cichlid (Cichlasoma citrinellum) (1988)
    Springer
    Cell & tissue research 253 (1988), S. 9-14 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Chromatophores ; Color change ; Ultrastructure ; Melanophores ; Macrophages ; Xanthophores ; Cichlasoma citrinellum (Teleostei: Cichlidae)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary We describe the histological basis of color metamorphosis in the polychromatic Midas cichlid, Cichlasoma citrinellum. Eight percent of the individuals in a natural population transform from gray with black markings to orange, simultaneously losing their ability to adjust coloration in response to background and social context. This trait is inherited. Light- and electron microscopy revealed that this transformation is a two-step process. First, the melanophores die, then macrophage-like cells remove the debris. As a result of this initial process, the underlying xanthophores become visible, producing the orange coloration. A similar process may occur in individuals that further transform to white, or go directly from gray to white.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00221733
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 155
    Digitale Medien
    Digitale Medien
    Cortical cytoskeleton of the flagellateProteromonas lacertae: Interrelation between microtubules, membrane and somatonemes (1988)
    Springer
    Protoplasma 142 (1988), S. 46-54 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Cytoskeleton ; Plasma membrane ; Microtubules ; Ultrastructure ; Freeze-fracture ; Flagellates ; Proteromonas lacertae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The anterior half of the cell surface of the parasitic flagellateProteromonas lacertae is corrugated while the posterior half is covered by hair-like appendages, called somatonemes. In the anterior part, the cortical microtubules are lined by a zig-zag shaped microfibril. Here, these two structures seem to be separated from the plasma membrane. In the posterior half of the cell the somatonemes, analogous to the mastigonemes of chrysophytes, are anchored to the cortical microtubules by paired small deposits of dense material. This was clearly demonstrated by Triton X 100 treatment which solubilized the plasma membrane but left the somatonemes attached to the cortical microtubules. Freeze-fracture images revealed the alignment of clustered intramembrane particles on the P-face of the plasma membrane which correspond to the attachment sites of the somatonemes, seen as dots in thin sections. The ER-derived membrane-associated somatonemes are probably linked to the cortical microtubules by anchoring proteins which are part of the plasma membrane.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01273225
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 156
    Digitale Medien
    Digitale Medien
    Observations of soybean root meristematic cells in response to heat shock (1988)
    Springer
    Protoplasma 144 (1988), S. 1-9 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Heat shock ; Soybean root ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Soybean seedlings (Glycine max) were incubated in narrow temperature regimes to study the effects of heat shock on cell structures. The incubation temperatures used were as follows: 1. 28 °C (2h); 2. 40 °C (2h); 3. 45 °C (2h); 4. 40 °C (2h)→45 °C (2h); 5. 47. 5 °C (10 min); 6. 40 °C (2h)→47. 5 °C (10 min). Both optical and electron micrographs were taken of the different tissues of root meristems as they responded to heat shock. Cells of roots heated to 45 °C (2h) or 47.5 °C (10 min) with lethal treatment showed drastic heat injuries:e.g., membrane damage, coagulated plasmolysis, protoplasmic contraction, and leakage of cell content. Nucleolar segregation occurred in cells treated at both lethal and supraoptimal temperatures. Seedlings preincubated at 40 °C (2 h) became thermo-tolerant to lethal temperature treatment of 45 °C (2 h) or 47.5 °C (10 min), by protecting the plasmalemma, mitochondria, plastids and nuclei from heat damage. Without preincubation, however, these structures were destroyed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01320274
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 157
    Digitale Medien
    Digitale Medien
    Metabolism of P-particles (polysaccharide particles) in mature pollen grains ofEryngium campestre L. (Apiaceae) (1988)
    Springer
    Protoplasma 146 (1988), S. 65-71 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Apiaceae ; Eryngium campestre ; Metabolism ; Pollen grain ; P-particle ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The metabolism of P-particles (polysaccharide particles) was investigated in mature pollen grains ofEryngium campestre L. Numerous P-particles, originating from dictyosome activity, are found to be accumulated near the apertures, followed by mitochondria. A single layer of ER profiles seems to prevent the fusion of the P-particles with the intine. Instead of this, they fuse with each other forming nonmembrane-bounded polysaccharide-aggregates, which subsequently change their granulated structure to an amorphous. Mitochondria together with small vesicles are involved in the conversion-process. The so formed wall precursors pass through the ER and fuse into the intine.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01405914
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 158
    Digitale Medien
    Digitale Medien
    Preliminary observations on the formation of the male germ unit in pollen tubes ofCyphomandra betacea sendt. (1988)
    Springer
    Protoplasma 147 (1988), S. 55-63 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Generative cell ; Sperm cell ; Treetomato ; Ultrastructure ; Vegetative nucleus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The structure of the generative cell and its association with the vegetative nucleus in the pollen tube ofCyphomandra betacea Sendt. were observed with the electron microscope. The generative cell, bounded by its own plasma membrane and the inner plasma membrane of the vegetative cell, possesses the cytoplasmic extension which lies within the embayments of a vegetative nucleus. The generative cell contains the normal complement of organelles and, especially, microtubules which cluster into several groups adjacent to the plasma membrane, oriented along the longitudinal axis of the cell. In the pollen tube reaching the lower end of the style aftersemivivo pollination, both of the sperm cells are elongated and polyribosomes and microtubules are the outstanding feature in the cytoplasm. The two sperm cells are connected by a common transverse cell wall, while cytoplasmic channels exist in both the periplasm of the two sperm cells and the transverse wall. The leading sperm cell (Svn) is closely associated with the vegetative nucleus. Thus the present study demonstrates the existence of the male germ unit in the pollen tube ofC. betacea. The possible cytoplasmic continuity between the sperm cells and between the gametes and vegetative cell is considered.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01403877
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 159
    Digitale Medien
    Digitale Medien
    Morphology ofEntomophthora muscae protoplasts grownin vitro (1988)
    Springer
    Protoplasma 146 (1988), S. 166-173 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Entomophthorales ; Entomophthora muscae ; Ultrastructure ; Cytochemistry ; Protoplast ; in vitro growth
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Entomophthora muscae (C.) Fres. can be grownin vitro as protoplasts. Light and electron microscopical studies of thein vitro developed protoplasts have demonstrated the absence of an organized wall over the protoplasmic Con A-positive membrane at all stages of growth. The cytological organization is typical of the Entomophthorales with condensed chromatin in the interphase nuclei and small eccentric metaphase spindles. Long strands of endoplasmic reticulum, microubules and vesicles surrounding the plasmalemma may be involved in maintaining the precise shape ofE. muscae protoplast. Starvation of the fungus induces the formation of hyphal bodies after deposition of Con A- and WGA-positive wall material at the plasmalemma surface.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01405926
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 160
    Digitale Medien
    Digitale Medien
    Effects ofl-propionylcarnitine on electrical and mechanical alterations induced by amphiphilic lipids in isolated guinea pig ventricular muscle (1988)
    Springer
    Heart and vessels 4 (1988), S. 197-206 
    Details
    ISSN: 1615-2573
    Schlagwort(e): l-Propionylcarnitine ; Amphiphile ; Action potential ; Ultrastructure ; Guinea pig ventricular muscle
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We examined the effects ofl-propionyl-carnitine (Prop.C), a short-chain acylcarnitine, on amphiphile (l-lysophosphatidylcholine orl-palmitoylcarnitine)-induced electrophysiological and ultrastructural changes in isolated guinea pig ventricular papillary muscles, under acidic conditions (pH 6.9). Conventional microelectrode, tension-recording, and electron microscope techniques were used. Both amphiphiles, at a concentration of 10−4 M, significantly decreased the resting membrane potential, action potential amplitude, and action potential duration, but increased the developed and resting tension. Such amphiphile-induced electrical changes were not observed in muscles pretreated with the beta-blocker, atenolol, although the mechanical changes remained unaffected. The application of Prop.C (10−2 M), in the continued presence of the amphiphiles caused a return of the action potential duration and the developed tension to the control level. However, the resting potential and action potential amplitude remained unaffected; in fact, the maximum upstroke velocity ( $$\dot V_{max} $$ ) of the action potential tended to decrease further. Pretreatment with Prop.C prevented all the amphiphile-induced electrophysiological and mechanical changes, except for $$\dot V_{max} $$ . Electron microscopic studies revealed that amphiphile-induced ultrastructural changes were prevented, at least in part, in the presence of Prop.C. Thus, Prop.C antagonizes some of deleterious effects of amphiphiles, such as lysophosphatidylcholine and palmitoylcarnitine, upon the electrical and mechanical activities of the ventricular muscle, under acidic conditions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02058587
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 161
    Digitale Medien
    Digitale Medien
    Dynamics of the microtubular cytoskeleton in the green algaAphanochaete magna (Chlorophyta). I. Late mitotic stages and the origin and development of the phycoplast (1988)
    Springer
    Protoplasma 142 (1988), S. 176-187 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Aphanochaete ; Astral microtubules ; Immunofluorescence ; Phycoplast ; Spindle breakdown ; 3-D reconstruction ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The spatial and temporal organization of the microtubular cytoskeleton at the transitional stage of mitosis and cytokinesis has been studied in the chaetophoralean green algaAphanochaete magna using indirect immunofluorescence light microscopy and transmission electron microscopic analysis of serial sections including computer-aided three-dimensional reconstruction. At late mitosis, elaborate asterlike microtubule systems including bundles interconnecting both centriolar regions are present. These systems disappear a the onset of interzonal spindle disintegration. The incipient phycoplast consists of a star-shaped microtubule assemblage projecting from the intact interzonal spindle. It develops strongly at the time of spindle disintegration, later on it becomes compressed by daughter nuclei movement. Cell plate formation is associated with a two-dimensional phycoplast. Phycoplast microtubules remain for a while associated with the completed cross wall but finally they depolymerize. The general occurrence of astral microtubule systems (includingA. magna) is evaluated. The subsequent developmental stages of the phycoplast, formation, maturation and depolymerization, are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01290874
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 162
    Digitale Medien
    Digitale Medien
    Ultrastructural aspects of the hyphal tip ofSclerotium rolfsii preserved by freeze substitution (1988)
    Springer
    Protoplasma 146 (1988), S. 143-149 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Hyphal tip ; Ultrastructure ; Freeze substitution ; Sclerotium rolfsii
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The hyphal tip ofSclerotium rolfsii was examined after fixation by freeze substitution. The Spitzenkörper consisted of a dense mass of apical vesicles and microvesicles surrounding a vesicle-free zone. Linear arrangements of microvesicles were occasionally observed within the Spitzenkörper. Abundant microfilaments were seen within the Spitzenkörper region, often in close association with apical vesicles and microvesicles. Microtubules passed through the Spitzenkörper and terminated at the plasmalemma at the extreme hyphal apex. Filasomes were mostly observed within the apical region and were in close proximity to the plasmalemma. Rough ER, mitochondria, microtubules, and vacuoles were abundant in the subapical region and were usually oriented parallel to the long axis of the hypha. Ribosomes were aligned on the outer surfaces of mitochondria. Golgi body equivalents were observed throughout the subapical region and appeared as inflated cisternae of varying shapes and electron opacities. Relationships to other basidiomycetous hyphal tip cells are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01405923
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 163
    Digitale Medien
    Digitale Medien
    Sublethal muscle fibre injuries after high-tension anaerobic exercise (1988)
    Springer
    European journal of applied physiology 57 (1988), S. 360-368 
    Details
    ISSN: 1439-6327
    Schlagwort(e): Humans ; Skeletal muscles ; Anaerobic exercise ; Histocytochemistry ; Ultrastructure ; Muscle cell injury
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The vastus lateralis muscles of eleven male elite sprinters (17–28 years) were investigated in order to examine the impact of high tension anaerobic muscular work on muscle fibre fine structure. In an attempt to reproduce the training regimen six subjects ran 20 repetitions of 25 s on a treadmill with 2 min 35 s in between, at a speed corresponding to 86% of their personal best 200 m time. PAS-stained sections of biopsies taken approximately 2 h after training generally indicated glycogen depletion in type 1 and type 2B fibres. At the light microscopic level, no signs of inflammation or fibre rupture were observed. However, at the ultrastructural level, frequent abnormalities of the contractile material and the cytoplasmic organelles were detected. Z-band streaming, autophagic vacuoles and abnormal mitochondria were the most conspicuous observations. Control specimens from sprinters who did not perform the acute exercise routine also displayed structural deviations, although to a lesser degree. It is hypothesized that during sprint training the leg musculature is put under great mechanical and metabolic stress which causes the degenerative response reported here.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00635996
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 164
    Digitale Medien
    Digitale Medien
    Intrathecal ACNU — a new therapeutic approach against malignant leptomeningeal tumors (1988)
    Springer
    Journal of neuro-oncology 6 (1988), S. 221-226 
    Details
    ISSN: 1573-7373
    Schlagwort(e): leptomeningeal tumor ; intrathecal chemotherapy ; ACNU ; nitrosourea ; pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Pharmacokinetics, toxicity and therapeutic efficacy of intrathecal ACNU, 3-((4-amino-2-methyl-5-pyrimidinyl)methyl)-1-(2-chloroethyl)-1-nitrosourea, were studied in rats to determine if it is a new and effective method for the treatment of malignant leptomeningeal tumors. Pharmacokinetics of intracisternally administered ACNU was studied by macroscopial autoradiography using 14C-labeled ACNU. It was demonstrated that intracisternally administered ACNU distributed in the subarachnoid space and subpial layer of the brain in high concentration and was rapidly eliminated into the systemic circulation. The diffusional transport of ACNU into the deeper part of the brain was limited. More than 3.0 mg/kg of intracisternal ACNU induced progressive loss of the weight of body in normal rats, and 80% of the rat given 6.0 mg/kg died. Increase of capillary permeability, neuronal loss and gliosis were observed in the marginal layer of the brain facing to the subarachnoid space in the rat given more than 3.0 mg/kg of ACNU. Systemic and local toxicity was not observed in the rat given less than 1.5 mg/kg. Therapeutic effect of intrathecal ACNU against leptomeningeal tumors was evaluated in the rat with meningeal carcinomatosis induced by intracisternal inoculation of Walker 256 carcinosarcoma cells. The median survival time of the rat treated with 1.5 mg/kg of intracisternal ACNU once on day 2 or on day 5 after tumor inoculation was significantly prolonged by 173%, and 214% at maximum, respectively, as compared with that of the untreated animal. These findings suggest that intrathecal ACNU may be of value for clinical trial against leptomeningeal tumors.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00163704
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 165
    Digitale Medien
    Digitale Medien
    The use of mass balance principles to describe regional drug distribution and elimination (1988)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 16 (1988), S. 13-29 
    Details
    ISSN: 1573-8744
    Schlagwort(e): pharmacokinetics ; mass balance ; regional distribution ; regional elimination
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Mass balance principles were used to derive a number of terms that are helpful in describing the rate and extent of regional drug uptake. Regional drug uptake was defined as the net movement of drug from the blood perfusing a region into the extravascular space of the region due to the distribution and/or elimination of the drug. By analogy with the traditional physiological definition of flux, net drug flux was defined as the difference in mass per unit time of drug respectively entering and leaving a region via the arterial and venous blood vessels. The timeintegral of net drug flux, net drug mass, was defined as the mass of drug that has entered a region via the arterial blood vessels but has not left the region via the venous blood vessels. For regions in which no drug elimination occurs, the mean regional drug concentration was defined as the net drug mass divided by the mass of the region. When a number of criteria are satisfied, the net drug flux is approximately the rate of drug uptake and the net drug mass is approximately the extent of drug uptake. Several examples are given to demonstrate the broad range of applications of mass balance principles. First, the method was used to characterize the differences between drug distribution and elimination in a hypothetical region using drug concentrations simulated from compartmental models of either distribution alone or distribution with elimination. Second, the whole body distribution net flux was described during a constant rate infusion of iodohippurate (IOH) into a sheep from the difference between the whole body net flux and renal net flux of IOH. Third, the time course of the mean myocardial lignocaine (lidocaine) concentrations in a sheep after an intravenous bolus of lignocaine were described. The time course of the lignocaine-induced depression of myocardial contractility followed more closely the mean myocardial lignocaine concentrations than that of either the arterial or coronary sinus blood concentrations. It is concluded that the use of mass balance principles provides a simple, empirical, and physiologically based method for the determination of the rate and extent of both drug distribution and elimination in regions as simple as single organs or as complex as the whole body.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01061860
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 166
    Digitale Medien
    Digitale Medien
    The uptake and elution of lignocaine and procainamide in the hindquarters of the sheep described using mass balance principles (1988)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 16 (1988), S. 31-40 
    Details
    ISSN: 1573-8744
    Schlagwort(e): lignocaine ; procainamide ; pharmacokinetics ; mass balance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Mass balance principles were used to describe the uptake and elution of lignocaine (lidocaine) and procainamide in the hindquarters of the sheep. Each of four sheep received a right atrial infusion of either lignocaine · HCl (2.7 mg/min) or procainamide · HCl (5.5mg/min) for 180 min. Paired arterial and inferior vena cava (draining the hindquarters) blood samples were taken at 20-min intervals during the infusion and for 180 min after the infusion. Lignocaine and procainamide mean total body clearances were 2.9 L/min (SD 1.1) and 1.3 L/min (SD 0.2), respectively. An index of the uptake and elution of these drugs in the hindquarters was estimated from the net drug mass per unit hindquarter blood flow;indirect evidence suggested that hindquarter blood flow was constant. All the net mass/flow of procainamide that was taken into the hindquarters during the infusion also eluted after the infusion, demonstrating reversible distribution into the tissues. However, uptake of procainamide was still occurring when blood concentrations were constant, indicating that the concentrations of procainamide in the hindquarters were not in equilibrium with the inferior vena cava concentrations. Lignocaine did not reach constant blood concentrations during the infusion and showed no tendency to reach arteriovenous equilibration; an arteriovenous difference of 22%(SD5%) across the hindquarters was measured during the last 60 min of the infusion. By 180 min after the lignocaine infusions, 79% (SD 8%) of the lignocaine net mass/flow had not eluted from the hindquarters when arterial and venous lignocaine concentrations were not significantly different. This drug could remain uneluted due to metabolism and/or avid tissue binding, and presents difficulties in the interpretation of pharmacokinetic data whether based on arterial or venous blood sampling.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01061861
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 167
    Digitale Medien
    Digitale Medien
    On the dose dependency of Cyclosporin a absorption and disposition in healthy volunteers (1988)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 16 (1988), S. 331-353 
    Details
    ISSN: 1573-8744
    Schlagwort(e): Cyclosporin A ; pharmacokinetics ; dose dependency ; oral absorption ; disposition ; healthy subjects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The pharmacokinetics of Cyclosporin A (CyA, SandimmuneR) was studied in 12 healthy male volunteers after oral dosing of 350 mg, 700 mg, and 1400 mg as a drinking solution. Blood samples were collected over 96 hr and analyzed by high pressure liquid chromatography. Concentration data were evaluated with model-independent and model-based linear pharmacokinetic concepts. Individual CyA concentration-time profiles in whole blood were well described by a two-compartment open model with zero-order absorption for all three doses. Comparison of pharmacokinetic parameters across doses indicates that both absorption and disposition are dose-dependent. Nonlinear disposition is suggested by the significant increase of the terminal half-life from 8.9±4.9hr to 11.9±4.9hr (mean±SD) after a 350 mg and a 1400 mg dose, respectively. Changes in the metabolic activity of the liver with concentration might be responsible for this phenomenon. In addition, the modeling approach indicated that bioavailability decreases with increasing dose. Moreover, the dependence of the rate of CyA absorption (zero-order rate constant) versus dose was well described by a hyperbola. The limited solubility of the drug in the gastrointestinal tract might be responsible for this behavior. The lag time (0.2–0.8 hr) was independent of dose. This value is similar to the time of gastric emptying in fasting volunteers. The duration of absorption for 11 of 12 subjects was in the range 2.5–3.5 hr over all doses and agrees well with the small intestine transit time. Some subjects showed a marked secondary peak at one or two doses, which could be adequately fitted by a model with two successive zero-order inputs. This double-peak behavior was ascribed to the influence of the food on gastric emptying. Dose dependency of disposition and absorption counterbalance each other in the usual dose range. This leads to an almost proportional increase of area under the blood CyA concentration-time profile with increasing dose.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01062550
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 168
    Digitale Medien
    Digitale Medien
    Pharmacokinetic modeling of the anticonvulsant response of oxazepam in rats using the pentylenetetrazol threshold concentration as pharmacodynamic measure (1988)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 16 (1988), S. 203-228 
    Details
    ISSN: 1573-8744
    Schlagwort(e): oxazepam ; pharmacokinetics ; pharmacodynamics ; anticonvulsant response ; pentylenetetrazol threshold ; kinetic-dynamic model
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract This investigation developed strategies along which the anticonvulsant effect of oxazepam in the rat could be pharmacokinetically modeled. After determination of the pharmacokinetics of oxazepam, which could be described with a two-compartment model (halflives of distribution and elimination 6 and 52 min, respectively), the drug was administered iv to groups of animals to achieve a serum concentration range of 0.1–2.5 mg/L at 10, 45, and 120 min after administration. At these time points pentylenetetrazol (PTZ) was infused slowly until the first myoclonic jerk occurred. The anticonvulsant response, expressed as the elevation of the serum or brain threshold concentration of PTZ, was modeled versus the serum (both total and free) and brain oxazepam concentration, according to the sigmoid E max model. The total serum and brain oxazepam EC50 values are about 0.5 mg/L and 1.1 mg/kg, respectively, and E max 120 mg/L PTZ. No marked differences in pharmacodynamic parameters between the three time groups were found, which indicates that serum and brain are pharmacokinetically indistinguishable from the effect compartment, that there is no (inter) activity of oxazepam metabolites and absence of development of acute tolerance during the investigated time frame. An interfering role of metabolites was also excluded by a direct radioreceptor assay of oxazepam, yielding very similar results as the specific Chromatographic assay. It is concluded that the concentration-anticonvulsant effect relationship of oxazepam can satisfactorily be described by the sigmoid E max model, when utilizing the employed experimental strategies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01062261
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 169
    Digitale Medien
    Digitale Medien
    An Implantable Pump for Intrarenal Infusion of Immunosuppressants in a Canine Autotransplant Model (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 781-785 
    Details
    ISSN: 1573-904X
    Schlagwort(e): pharmacokinetics ; 6-mercaptopurine ; targeted drug delivery ; renal transplantation ; intraarterial infusion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract We developed a canine renal allograft model utilizing implantable infusion pumps and biocompatible catheters to investigate the pharmacokinetics of local immunosuppressive drug administration. Seven mongrel dogs underwent bilateral nephrectomy and autotransplantation of one kidney to the iliac vessels. The proximal end of an infusion catheter directed into the iliac artery was tunneled to a subcutaneously placed programmable pump. A second, sampling catheter was placed with its tip in the iliac vein. Simultaneous regional (iliac vein) and systemic (jugular vein) venous concentrations of 6-mercaptopurine (6-MP), the immunosuppressive metabolite of azathioprine, were determined during a continuous 24-h intraarterial infusion (10 mg/kg/24 hr). The gradient between regional and systemic 6-MP concentrations was maximal initially when the pump was turned on, continuously decreased until steady state was reached, and disappeared immediately after the pump was turned off. The mean ratio of steady-state iliac vein to systemic 6-MP concentrations was 5.0 ± 1.4, demonstrating a pharmacokinetic advantage of continuous intraarterial 6-MP infusion to the autotransplanted kidney. The novel canine renal allograft model described herein overcomes the technical limitations of earlier models and represents a foundational step in the design of intrarenal infusion patterns of immunosuppressive agents which we expect to prolong survival of the allotransplanted kidney with minimal systemic drug exposure and side effects.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1015940802451
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 170
    Digitale Medien
    Digitale Medien
    Liquid Chromatographic Analysis of Di(2-ethylhexyl) Phthalate: Application to Pharmacokinetic Studies in the Mongrel Dog (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 10-15 
    Details
    ISSN: 1573-904X
    Schlagwort(e): di(2-ethylhexyl) phthalate ; liquid chromatographic (LC) analysis ; pharmacokinetics ; renal failure ; mongrel dog
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract A high-performance liquid chromatographic (HPLC) assay was developed for the determination of di(2-ethylhexyl) phthalate (DEHP) in serum or plasma. Plasma DEHP concentrations that were measured by HPLC in specimens obtained from hemodialysis patients were in good agreement with corresponding concentrations that were measured by gas chromatography with selected ion monitoring (GC-SIM) (r 2 = 0.996). Plasma DEHP concentrations were measured after intravenous DEHP administration (1.2–4.4 mg DEHP/kg body weight) to determine the effect of bilateral ureteral ligation on DEHP elimination in the mongrel dog. DEHP plasma clearance (∼6.3 ml/min/kg), steady-state distribution volume (∼0.2l/kg), and terminal half-life (∼50 min) were unchanged in two dogs following bilateral ureteral ligation. DEHP terminal half-life and steady-state distribution volume were substantially smaller (25- to 70-fold) than reported previously in the rat or dog.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1015872309411
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 171
    Digitale Medien
    Digitale Medien
    The effect of low pH and aluminum on the olfactory organ of rainbow trout, Salmo gairdneri (1988)
    Springer
    Environmental biology of fishes 22 (1988), S. 69-77 
    Details
    ISSN: 1573-5133
    Schlagwort(e): Acid ; Metals ; Ultrastructure ; Olfaction ; Electrical response ; Pollution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Synopsis The effects of acid ((H2SO4) and aluminum AIKSO4 in acidified water on rainbow trout, Salmo gairdneri, olfactory organ were examined using scanning electron microscopy and electrophysiology. Exposure to pH 4.7 resulted in an increase in the number of mucus droplets over parts of the olfactory epithelium, primarily along the ridges of the secondary folds. The addition of aluminum (5.0, 9.5, 20.0 µmol · 1−1) at pH 4.7 resulted in loss of receptor cell cilia, irregularly shaped olfactory knobs, clumped microvilli and swellings on microridge cells. Electrical responses recorded from the olfactory nerve in response to the amino acid L-serine were similar to controls in fish exposed to acidified water. When fish were exposed to acidified water and aluminum the response was depressed. These morphological and electrophysiological changes could be used to indicate metal-induced stress in fish from natural ecosystems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00000544
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 172
    Digitale Medien
    Digitale Medien
    Mucus-producing adenopapillary carcinoma of minor salivary gland origin with signet ring cells and intracytoplasmic lumina (1988)
    Springer
    European archives of oto-rhino-laryngology and head & neck 245 (1988), S. 145-150 
    Details
    ISSN: 1434-4726
    Schlagwort(e): Salivary gland tumor ; Adenocarcinoma ; Ultrastructure ; Signet-ring cell ; Intracytoplasmic lumen
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A histological and subcellular study of a mucus-producing adenopapillary carcinoma of a minor salivary gland is presented. The tumor was located on the buccal mucosa of a 36-year-old white man. Microscopic examination showed that the tumor was an invasive papillary growth with numerous signet-ring cells and mucous production. When viewed under the electron microscope, the tumor exhibited clusters of cells showing intracellular lumina and finely dispersed chromatin.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00464016
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 173
    Digitale Medien
    Digitale Medien
    The basement membrane and associated structures in the murine endolymphatic sac (1988)
    Springer
    European archives of oto-rhino-laryngology and head & neck 245 (1988), S. 266-272 
    Details
    ISSN: 1434-4726
    Schlagwort(e): Murine endolymphatic sac ; Basement membrane ; Fluid transport ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructure of the basement membrane of the murine endolymphatic sac was studied under various experimental conditions in labyrinthectomized and ethacrynic acid-treated animals and was compared with normal anatomy. The basement membrane was clearly visualized after staining with ruthenium red or dialyzed iron. The basement membrane of the murine sac consists of two different layers: the lamina rara and the lamina densa. It demarcates the border between the epithelial cells and the subepithelial connective tissue. Our findings suggest that the basement membrane acts as a physical support to the epithelium in the endolymphatic sac. The basement membrane also shows a dynamic capacity to form a new basement membrane, with the result that the lateral intercellular space between contiguous epithelial cells may be integrated with the subepithelial space. This system is believed to act as a macromolecular and bulk water transport system. In the subepithelial space, collagen, reticular and elastic fibrils are found having a close relationship to the basement membrane. The elastic fibres are presumed to play a role in the pressure-regulating mechanism in the endolymphatic sac.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00464628
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 174
    Digitale Medien
    Digitale Medien
    Ciliated mucous cells found in the nasal mucosa of a patient with Kartagener's syndrome (1988)
    Springer
    European archives of oto-rhino-laryngology and head & neck 244 (1988), S. 360-362 
    Details
    ISSN: 1434-4726
    Schlagwort(e): Nasal mucosa ; Kartagener's syndrome ; Ciliated mucous cells ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Transmission electron microscopy revealed the presence of ciliated cells containing many mucous secretory granules in the nasal surface epithelium of a 13-year-old patient suffering from Kartagener's syndrome. In these cells, mucous secretory granules were accumulated in the apical cytoplasm, and the Golgi apparatus was well developed in the supranuclear region. Mucous secretory granules were discharged infrequently through the apical cell membranes by single or compound exocytosis. The cells were considered to be ciliated mucous cells, which have already been reported to be present in the lower respiratory tract but not in the upper respiratory tract.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00497465
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 175
    Digitale Medien
    Digitale Medien
    Peripheral pharmacokinetic parameters of levodopa/carbidopa and the on-off phenomenon in parkinsonian patients (1988)
    Springer
    Neurological sciences 9 (1988), S. 255-259 
    Details
    ISSN: 1590-3478
    Schlagwort(e): Parkinson disease ; levodopa ; pharmacokinetics ; on-off phenomenon
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Sommario I principali parametri farmacocinetici periferici della associazione levodopa/carbidopa sono stati studiati in 11 volontari sani ed in 16 pazienti affetti da morbo di Parkinson in differenti stadi di malattia, con e senza fluttuazioni delle performances motorie. Dopo somministrazione per via orale di una dose standard del farmaco (levodopa 250 mg., carbidopa 25 mg.), i valori della concentrazione plasmatica massima, del tempo di comparsa del picco e dell'area sotto la curva concentrazione/tempo sono risultati simili in tutti i gruppi esaminati. La farmacocinetica periferica dell'associazione levodopa/carbidopa non è risultata essere differente nei parkinsoniani che presentavano delle fluttuazioni delle performances motorie in confronto ai pazienti con stabile risposta clinica alla terapia.
    Notizen: Abstract The principal peripheral pharmacokinetic parameters of the levodopa/carbidopa association were investigated in 11 healthy volunteers and in 16 patients at various stages of Parkinson disease, with and without the on-off phenomenon. After oral administration of a standard dose of drug (levodopa 250 mg + carbidopa 25 mg) the peak plasma concentrations, peak onset time and area under the curve/time proved to be similar across the groups. There was no difference in peripheral pharmacokinetics of the association between parkinsonian patients with swings in response and those without.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02334049
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 176
    Digitale Medien
    Digitale Medien
    Quantitative Structure–Activity Study on Human Pharmacokinetic Parameters of Benzodiazepines Using the Graph Theoretical Approach (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 201-208 
    Details
    ISSN: 1573-904X
    Schlagwort(e): quantitative structure–activity analysis (QSAR) ; topological approach ; benzodiazepines ; pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The graph theoretical indices for a series of 13 benzodiazepines were calculated using a graph-path topological method. The total molecule, the ring fragments, and combinations of ring fragments were subjected to a quantitative structure–activity analysis using eight pharmacokinetic parameters. The metabolic clearance and the blood-to-plasma concentration ratios were most highly correlated with the graph theoretical indices, with R values of 0.975 and 0.938, respectively. These correlations were found when the diazepine + benzo fragment and phenyl fragment were used to calculate the graph-path indices. Terminal disposition half-life was correlated with the benzo + diazepine fragment, with R = 0.969. Truncating the graph-path codes by eliminating cycles in the total molecule markedly improved the correlation coefficients. When compared to the graph-path indices for the total molecule, the correlation coefficients for the terminal disposition half-life and metabolic clearance data rose from 0.721 to 0.935 and from 0.770 to 0.968, respectively, using the graph-path indices of the truncated molecule. Intrinsic clearance of unbound drug also was poorly correlated with the total molecule (r 〈 0.7) but rose significantly using the graph-path indices of the truncated moleucle (r = 0.971 and 0.975 for the well-stirred and parallel-tube models, respectively.)
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1015933527583
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 177
    Digitale Medien
    Digitale Medien
    Stereoselective Binding of Disopyramide to Plasma Proteins (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 316-318 
    Details
    ISSN: 1573-904X
    Schlagwort(e): disopyramide ; pharmacokinetics ; plasma proteins ; stereoisomers
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1015986906627
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 178
    Digitale Medien
    Digitale Medien
    Cimetidine Elimination from the Cerebrospinal Fluid of the Rat (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 628-633 
    Details
    ISSN: 1573-904X
    Schlagwort(e): cimetidine ; cerebrospinal fluid ; clearance ; choroid plexus ; pharmacokinetics ; transport
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The major goal of this study was to develop a small animal model that could be used to assess quantitatively the clearance of cimetidine from the cerebrospinal fluid (CSF) under relatively physiologic conditions. In addition, we addressed questions related to the pathways involved in the elimination of cimetidine from the CSF. We administered high and low bolus doses of cimetidine together with inulin, as a marker of bulk flow, into the lateral ventricle of anesthetized rats and sampled CSF from the cisterna magna. Principles of linear pharmacokinetic systems were applied to the data to obtain clearances from the CSF. The clearance of inulin was 2.02 ± 0.22 µl/min, which is in excellent agreement with the CSF production rate of 2.2 µl/min in anesthetized rats. The clearance of cimetidine from the CSF following the administration of a low dose was 11.8 ± 3.1 µl/min, which is in good agreement with the cimetidine CSF clearance in the rat obtained previously in studies using the technique of ventriculocisternal perfusion. A 32% decrease in the CSF clearance of cimetidine (P 〈 0.05) was observed when the high dose was administered, suggesting that CSF elimination is saturable. The clearance of inulin was unaffected by the high dose of cimetidine. This study demonstrates that the technique of lateral ventricle injection and sampling from the cisterna magna is useful in quantitatively assessing the elimination of compounds from the CSF in the rat under relatively physiologic conditions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1015918802935
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 179
    Digitale Medien
    Digitale Medien
    Liquid Chromatographic Assay and Pharmacokinetics of Quazepam and Its Metabolites Following Sublingual Administration of Quazepam (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 365-368 
    Details
    ISSN: 1573-904X
    Schlagwort(e): quazepam ; metabolites ; reversed phase ; high-performance liquid chromatography ; solid-phase extraction ; plasma ; sublingual ; pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract A reverse-phase liquid chromatographic method is described for simultaneous quantification of quazepam, and two of its metabolites, 2-oxoquazepam and N-desalkyl-2-oxoquazepam. The method uses a solid-phase extraction procedure to prepare plasma samples. After extraction, the methanolic extract is evaporated; the residue is then reconstituted in a small volume of mobile phase and chromatographed. The total chromatography time for a single sample is about 20 min. A sensitivity of 1 ng/ml for quazepam and its metabolites is attained when 1 ml of plasma is extracted. Analytical recovery of quazepam and its metabolites added to plasma ranged from 87 to 96%. The maximum within-day and day-to-day coefficients of variation for each compound at concentrations of 20 and 60 ng/ml were 7.6 and 11.2%, respectively. The method was applied to sublingual pharmacokinetic studies of quazepam in healthy volunteers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1015907611170
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 180
    Digitale Medien
    Digitale Medien
    Comparative Pharmacokinetics of Methylprednisolone Phosphate and Hemisuccinate in High Doses (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 509-513 
    Details
    ISSN: 1573-904X
    Schlagwort(e): methylprednisolone phosphate ; methylprednisolone hemisuccinate ; pharmacokinetics ; saliva analysis ; endogenous hydrocortisone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The pharmacokinetics of methylprednisolone and two methylprednisolone esters, the phosphate and the hemisuccinate, were investigated after intravenous administration of the esters to 12 healthy male subjects in two different doses (250 and 1000 mg). Methylprednisolone was formed more rapidly from phosphate than from hemisuccinate. During the first 30 min methylprednisolone levels were three to four times higher after phosphate administration than after hemisuccinate. The mean residence time of the hemisuccinate was significantly longer and the total-body clearance lower than those of the phosphate. Whereas very little of the phosphate (mean, 1.7%) was eliminated unchanged into the urine, there were significant amounts of hemisuccinate (mean, 14.7%) excreted renally and therefore not bioavailable. Methylprednisolone saliva levels paralleled plasma levels; the average saliva/plasma ratio was 0.22. Neither phosphate nor hemisuccinate could be detected in saliva. An average of 7.2% of the administered dose was eliminated in the form of methylprednisolone in urine. Renal clearance was 24 ml/min and not dose or prodrug dependent. For both doses endogenous hydrocortisone levels were lowered after 24 hr. For the 1000-mg dose the depression was still significant after 48 hr. The results indicate that methylprednisolone phosphate results in a faster and more efficient conversion to its active form, methylprednisolone, than methylprednisolone hemisuccinate.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1015921408870
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 181
    Digitale Medien
    Digitale Medien
    Pharmacokinetics and Bioavailability of Hydromorphone: Effect of Various Routes of Administration (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 718-721 
    Details
    ISSN: 1573-904X
    Schlagwort(e): hydromorphone ; intranasal ; transdermal ; pharmacokinetics ; bioavailability
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The pharmacokinetics and bioavailability of hydromorphone following various routes of administration, i.e., intravenous, oral, intranasal, and transdermal, were investigated in rabbits. Hydromorphone plasma concentrations were determined by reverse-phase high-performance liquid chromatography (HLPC). Comparison of area under the concentration versus time curve (AUC) between intravenous and oral administrations showed a low bioavailability of hydromorphone after oral administration. The nasal absorption of hydromorphone was studied by the in situ nasal recirculation technique, and the results showed that hydromorphone is well absorbed from the nasal mucosa. The transdermal permeation of hydromorphone was also evaluated for 24 hr and a steady-state plasma concentration (0.135 µg/ml) was achieved during the 6- to 24-hr periods following the application of a transdermal patch on the inner pinna of the rabbit's ear.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1015959912021
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 182
    Digitale Medien
    Digitale Medien
    Exogenous Methemoglobin as a Cyanide Antidote in Rats (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 749-752 
    Details
    ISSN: 1573-904X
    Schlagwort(e): methemoglobin ; cyanide antidote ; cyanide poisoning ; pharmacokinetics ; rats
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The effects of the administration of methemoglobin (MetHb) prepared in vitro were evaluated in Sprague–Dawley rats given increasing doses of potassium cyanide (KCN). Median lethal dose (LD50) studies were conducted by giving intraperitoneal injections of KCN (in 0.3- to 0.5-ml volumes), then 2 min later administering intravenous (iv) doses of 1000, 1500, or 2500 mg/kg of MetHb through the tail vein. Control rats received an equivalent volume of saline. The resulting LD50 values for KCN were 7.4 ± 1.1, 11.7 ± 1.1, 13.9 ± 1.0, and 14.2 ± 1.0 mg/kg (mean ± SD) for the control (no MetHb) and 1000-, 1500-, and 2500-mg/kg dose groups, respectively. Additional groups of rats were given 1000, 1500, or 2500 mg/kg MetHb and submitted for necropsy. The gross finding of darkened kidneys was present in both dose groups, but became consistent and more prominent in the 2500-mg/kg dose group. Evidence of pathologic changes was not present in other organs. Single-dose pharmacokinetic studies were conducted using iv doses of 1600 and 2500 mg/kg MetHb. The elimination half-life was similar in both doses (62.6 min), but the volume of distribution (95.3 ± 7.2 and 126.3 ± 5.2 ml/kg, mean ± SE) and clearance (1.1 ± 0.1 and 1.5 ± 0.1 ml/min/kg) were significantly different (P 〈 0.05) for the 1600-and 2500-mg/kg dose groups, respectively. From these data we conclude that although MetHb is cleared from the vascular system rapidly, it may be an effective and nontoxic antidote for doses of cyanide up to twice that of the control LD50.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1015928432494
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 183
    Digitale Medien
    Digitale Medien
    Capillary Gas Chromatography and Thermionic N-P-Specific Detection of 13-Bis(2-chloroethyl)-l-nitrosourea (BCNU) or l-(2-Chloroethyl)-3-cyclohexyl-l-nitrosourea (CCNU) in Stability and Pharmacokinetic Studies (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 220-225 
    Details
    ISSN: 1573-904X
    Schlagwort(e): capillary gas chromatography ; analysis ; stability ; pharmacokinetics ; carmustine ; lomustine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract An expedient, rapid, and sensitive capillary gas chromatographic method for the analysis of l,3-bis(2-chloroethyl)-l-nitrosourea (BCNU) or l-(2-chloroethyl)-3-cyclohexyl-l-nitrosourea (CCNU) in plasma is described. Separation of the underivatized nitrosourea compounds was performed on a 0.33-mm-i.d., 25-m fused-silica, SE-30 capillary column, and detection was carried out using a thermionic N–P-specific detector. The compounds were extracted from plasma with benzene with a yield of 〉87%. The assay was linear in the ranges of 0.001 to 0.5 and 0.5 to 25 µg/ml for CCNU or 0.003 to 0.50 and 0.5 to 25 µg/ml for BCNU, with correlation coefficients from 0.9914 to 0.9999 and coefficients of variation (CV) of 〈3.3%. Other antineoplastic agents did not interfere in the assay. The method was employed to study the pharmacokinetics of BCNU in rabbits. The plasma concentration-time curves were fit to a two-compartment model with a mean (SE) α, β, and total-body clearance of 2.898 (0.913) hr−1, 0.1228 (0.0179) hr−1, and 7.211 (2.862) liters/hr · kg, respectively. Further, the stability of BCNU and CCNU in solution was examined at different temperatures. Both compounds were stable in benzene or acetone (4 to 37°C) but labile in plasma even if refrigerated. The apparent rate constants for degradation of BCNU and CCNU were 0.09921 and 0.02853 hr−1 at 4°C and 5.998 and 2.553 hr−1 at 37°C, respectively.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1015989612562
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 184
    Digitale Medien
    Digitale Medien
    Dextromethorphan Pretreatment Induces Antipyrine Clearance in the Rat (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 437-439 
    Details
    ISSN: 1573-904X
    Schlagwort(e): antipyrine ; dextromethorphan ; drug metabolism ; enzyme induction ; pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Numerous agents that undergo extensive first-pass metabolism have been shown to inhibit oxidative drug metabolism. To examine whether this effect is related to the chemical structure or pharmacokinetic characteristics of the inhibiting agent, we determined the effect of dextromethorphan (a compound which exhibits pharmacokinetic similarities to, but is chemically dissimilar from, previously studied agents) on the disposition of antipyrine. A single oral dose of dextromethorphan hydrobromide, 100 mg/kg, 1 hr prior to antipyrine administration had no significant effect on the pharmacokinetics of this model substrate. The administration of dextromethorphan at the same dose twice daily for 3 days and an additional dose 1 hr prior to antipyrine administration resulted in a 33% increase in the clearance of antipyrine. These data indicate that dextromethorphan is capable of inducing hepatic microsomal enzymes. Studies are needed to determine if this effect also occurs upon chronic administration in humans. These data suggest that the pharmacokinetic characteristic of extensive first-pass metabolism is not necessarily associated with inhibition of drug metabolism.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1015940518439
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 185
    Digitale Medien
    Digitale Medien
    Mean Residence Time Concepts for Pharmacokinetic Systems with Nonlinear Drug Elimination Described by the Michaelis–Menten Equation (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 156-164 
    Details
    ISSN: 1573-904X
    Schlagwort(e): mean residence time ; moment analysis ; pharmacokinetics ; Michaelis–Menten elimination ; compartmental models
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Equations for the mean residence time (MRT) of drug in the body and related functions are derived for drugs which are intravenously administered into a one- or two-compartment system with Michaelis–Menten elimination. This MRT is a function of the steady-state volume of distribution and time-average clearance obtained from the dose and area under the curve (dose/AUC). The differences between the MRT calculated by the proposed method and by using the moment theory method (AUMC/AUC) are demonstrated both mathematically and by computer simulations. The validity of the proposed method for calculation of MRT and its relationship to the moment theory result have also been assessed by examining the percentage of the administered dose eliminated and the percentage of the total area attained at MRT and at AUMC/AUC in relation to the dose. The equations evolved should be helpful in clarifying residence time derivations and in defining the disposition characteristics and differences between linear and nonlinear systems. Direct methods are provided for calculation of Michaelis–Menten parameters based on the relationship between MRT and dose.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1015960806202
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 186
    Digitale Medien
    Digitale Medien
    Calculations and Application of Mean Residence Times for Drugs Which Demonstrate One-Compartment Distribution and Michaelis-Menten Elimination (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 196-196 
    Details
    ISSN: 1573-904X
    Schlagwort(e): mean residence time ; pharmacokinetics ; Michaelis-Menten elimination ; one-compartment model
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1015977209836
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 187
    Digitale Medien
    Digitale Medien
    Pharmacokinetics, behavioral, and neurophysiological aspects of the action of 2-ethyl-6-methyl-3-hydroxypyridine in rats (1988)
    Springer
    Bulletin of experimental biology and medicine 106 (1988), S. 1104-1107 
    Details
    ISSN: 1573-8221
    Schlagwort(e): nootropic drugs ; pharmacokinetics ; behavior ; rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00840370
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 188
    Digitale Medien
    Digitale Medien
    Ultrastructural investigation of renal biopsies: A discussion of artifacts and special methodology (1988)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 9 (1988), S. 283-291 
    Details
    ISSN: 0741-0581
    Schlagwort(e): Ultrastructure ; Kidney ; Artifacts ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: The aim of this presentation is to draw attention to the problems inherent in evaluating the ultrastructure of percutaneous renal biopsies and to discuss some of the special techniques which are useful in this area. It is important to realize that the ultrastructure as it appears in this kind of material does not necessarily reflect conditions in vivo. Comparison with suitable reference material may, however, permit reliable conclusions in terms of pathological diagnosis and pathogenesis. It is advocated that purely qualitative methods, which until now have predominated in ultrastructure work with renal biopsies, be replaced by morphometry and semiquantitative methods when it is possible and practical to do so in any research situation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1060090305
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 189
    Digitale Medien
    Digitale Medien
    Synaptic organization of the globus pallidus (1988)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 10 (1988), S. 247-263 
    Details
    ISSN: 0741-0581
    Schlagwort(e): Ultrastructure ; Corpus striatum ; Pallidum ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: The synaptic organization of the globus pallidus is reviewed with respect to present knowledge about neurons, fibers, axon terminals, and their intrinsic synaptic relationships. Information derived from studies employing Nissl stains, Golgi impregnations, lesion degeneration techniques, immunohistochemistry, and anterograde axonal labeling in various species are presented along with ultrastructural data. Studies indicate that the globus pallidus contains a principal efferent neuron with smooth or spiny dendrites and simple or complex terminal dendritic arborizations. This cell type receives convergent inputs from intrinsic and extrinsic sources and uses γ-aminobutyric acid as a transmitter. A smaller and separate population of pallidal projection neurons contains acetylcholine. Two other less frequent neuronal types, of small and medium size, have also been recognized. Three to six types of axonal boutons forming synaptic contacts with pallidal neurons have been recognized in various studies. Among these, three types (types I, II, and III) are the most prevalent. Studies indicate that the most frequent category (type I) originates from neostriatal neurons via radial fiber projections and contains immunoreactive GABA and enkephalins. The synaptic architecture of the globus pallidus is dominated by a mosaic-like arrangement of long dendrites that are ensheathed by longitudinally oriented axons making synapses en passant. Triadic synapses involving dendrites that are pre- and postsynaptic are encountered infrequently. Because both striatopallidal and pallidothalamic connections are inhibitory, pallidal target neurons in the thalamus may be “disinhibited” when the neostriatum is activated.
    Zusätzliches Material: 23 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1060100304
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 190
    Digitale Medien
    Digitale Medien
    Malignancies in the acquired immunodeficiency syndrome (1988)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 8 (1988), S. 137-158 
    Details
    ISSN: 0741-0581
    Schlagwort(e): Kaposi's sarcoma ; Lymphoma ; Histology ; Ultrastructure ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Malignancies frequently arise in patients infected with human immunodeficiency virus (HIV), including those patients classified as having the acquired immunodeficiency syndrome (AIDS). Currently, Kaposi's sarcoma and certain types of lymphoma are considered to develop as a result of HIV infection, and other cancers have also been reported in these patients. For the most part, ultrastructural study of HIV-associated malignancies has been limited to Kaposi's sarcoma; the ultrastructural features of the epidemic form of this disease are generally the same as those of the classical form. The occurrence of these cancers in HIV-infected individuals appears to be related to the immunodeficiency caused by this virus, but the basic etiologic mechanisms remain unknown. In general, only palliative treatments are presently available for HIV-associated malignancies.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1060080110
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 191
    Digitale Medien
    Digitale Medien
    Morphology of synapses in the autonomic nervous system (1988)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 10 (1988), S. 187-204 
    Details
    ISSN: 0741-0581
    Schlagwort(e): Sympathetic nervous system ; Parasympathetic nervous system ; Enteric nervous system ; Ultrastructure ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: The ultrastructure of synapses in the autonomic nervous system is reviewed. The synaptic organization of the parasympathetic ganglia is relatively simple. Preganglionic axons form synapses either on the soma or on short perikaryal processes of the ganglionic neurons. The presynaptic terminals have a cholinergic morphology and contain mainly small clear vesicles with a few large dense cored vesicles. A few neuropeptides have been localized to the large dense cored vesicles of these terminals. The postganglionic parasympathetic axons ramify within their target tissues where they form close associations, but not true synaptic contacts. Sites of release of transmitter are recognized morphologically as varicosities along the length of the axon that contain clusters of small clear vesicles with a few large dense cored vesicles. The organization of the sympathetic nervous system is somewhat more complex. In addition to acetylcholine, enkephalin also exists in these terminals, probably in the large dense cored vesicles. There are at least three types of ganglion cell neurons in the paravertebral portion of the sympathetic nervous system: those that contain norepinephrine alone, those that contain norepinephrine along with neuropeptide Y, and those that contain acetylcholine and vasoactive intestinal polypeptide. The first type provides innervation to the parenchyma of the target tissues, while the second mainly innervates blood vessels. The third type innervates the sweat glands. In the prevertebral ganglia, a fourth type of neuron exists that contains norepinephrine and somatostatin. This neuron probably innervates the gut. Preganglionic terminals of the cholinergic type form synaptic connections mainly with the dendrites of the sympathetic ganglion neurons. In addition to the types of synapses described for the paravertebral ganglia, neurons in the prevertebral ganglia receive synaptic connections from dorsal root ganglia and from the enteric nervous system. The sympathetic ganglia also contain interneurons that receive preganglionic synapses and form efferent synapses with some of the principal ganglion cells. The interneurons have been shown to contain a variety of transmitters, including norepinephrine, epinephrine, dopamine, serotonin, and a number of neuropeptides. The postganglionic sympathetic axons have a similar morphology to the parasympathetic axons. They form networks in their targets, and the axons display varicosities with concentrations of both small and large vesicles. After appropriate fixation, these vesicles are seen to possess dense cores. The morphology of the enteric nervous system has the greatest complexity. There are sensory neurons, interneurons and motor neurons of various types. In addition, it receives extrinsic connections from both the sympathetic and parasympathetic nervous system. The synaptic ultrastructure is correspondingly complex, with a large number of different, morphologically disticnt types of synaptic terminals. The function and transmitter content of these terminals is beginning to be elucidated.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1060100205
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 192
    Digitale Medien
    Digitale Medien
    Das Rückstandsverhalten von Chloramphenicol nach intramuskulärer Applikation beim Schwein (1985)
    Springer
    European journal of nutrition 24 (1985), S. 113-119 
    Details
    ISSN: 1436-6215
    Schlagwort(e): Chloramphenicol ; pharmacokinetics ; residue ; pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft , Medizin
    Beschreibung / Inhaltsverzeichnis: Summary Residues of Chloramphenicol (CAP) were examined in 24 pigs after intramuscular injection of 30 mg CAP/kg body weight. Two pigs were slaughtered after 3, 6, 12,18, 24, 36 hours, 2, 3, 6, 10, 21 and 30 days, respectively. CAP-concentrations were determined in muscle, blood, urine, liver, kidney, bile, and fat. Methods used were gas-liquid chromatography and radioimmunoassay. Detection limits reached were 1−5 ppb. The concentration-time curves obtained reflected a long elimination phase and allowed only calculation of this half-life. Elimination half-life was estimated to be for muscle, blood and urine 160–170 hours, for kidney 310 and for bile 250 hours. Significant correlations were found to exist between CAP-concentrations in plasma and muscle. It appears that blood would be a good body fluid for monitoring CAP-residues in tissue.
    Notizen: Zusammenfassung Zur Untersuchung des Rückstandsverhaltens von Chloramphenicol (CAP) wurden 24 Mastschweine, 24–28 Wochen alt, intramuskulär mit 30 mg CAP/kg Körpergewicht behandelt und je 2 Tiere nach 3, 6, 12, 18, 24, 36 Stunden, 2, 3, 6, 10, 21 und 30 Tagen geschlachtet. Die CAP-Gehalte in Muskulatur, Blut, Urin, Leber, Niere, Galle und Fett wurden gaschromatographisch und radioimmunologisch bestimmt. Die Nachweisgrenze beider Methoden liegt in Abhängigkeit von der Matrix zwischen 1 und 5 ppb. Die erhaltenen Kinetiken weisen eine terminale Elimination auf, deren Halbwertszeiten für Muskulatur, Blut und Urin ca. 160–170 Stunden, für Niere 310 Stunden und für Galle 250 Stunden betragen. Die CAP-Konzentration in Muskulatur und Blut weisen eine signifikante, lineare Korrelation auf. Blutuntersuchungen könnten deshalb als Screening-Methode bei umfangreichen Rückstandskontrollen eingesetzt werden.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02020458
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 193
    Digitale Medien
    Digitale Medien
    An ultrastructural analysis of abnormal otic development in exencephalic mutant mice (1985)
    Springer
    European archives of oto-rhino-laryngology and head & neck 241 (1985), S. 203-208 
    Details
    ISSN: 1434-4726
    Schlagwort(e): Inner ear ; Loop-tail mouse ; Ultrastructure ; Development
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Homozygous loop-tail (Lp/Lp) mice exhibit defects in the otocyst as well as extensive neural dysraphism. At 9 days of gestation, cells in the otic pit of abnormal embryos are flattened and lack the rounded luminal contours characteristic of otic cells in their normal littermates. Apical filaments also are not as prominent as in normal embryos, and there is an increase in densely stained globular material in cells at the ventral lip of the otic pit. With glutaraldehyde-tannic acid fixation, the basal lamina of the otic pit cells shows differences from that of the normal otic pit. In abnormal specimens, the lamina densa is irregular and clumped, and the adjacent less dense area is spotty and lacks the more uniformly arranged and delicate fibrils characteristic of the normal basal lamina. These defects may reflect faulty developmental interactions between the dysraphic neural tube, mesenchymal cells, and otic anlage.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00454355
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 194
    Digitale Medien
    Digitale Medien
    Autosomal-dominant lamellar ichthyosis: Ultrastructural characteristics of a new type of congenital ichthyosis (1985)
    Springer
    Archives of dermatological research 278 (1985), S. 1-5 
    Details
    ISSN: 1432-069X
    Schlagwort(e): Lamellar ichthyosis ; Autosomal-dominant inheritance ; Ultrastructure ; Transforming cells ; Genetic counselling
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Recently, autosomal-dominant lamellar ichthyosis (ADLI) has been shown to be a new genetic trait with clinical and histologic features similar to those of autosomal-recessive lamellar ichthyosis. In two patients affected with ADLI, the malpighian keratinocytes showed ultrastructural signs of increased cellular metabolism. The tonofilaments and keratohyaline granules were regular in structure and number. However, as a distinctive ultrastructural feature, a prominent transforming zone was found between the granular and horny layers. Moreover, a normal keratin pattern and only a limited number of lipid inclusions were observed in the stratum corneum. Thus, ADLI can be distinguished from the autosomal-recessive forms of lamellar ichthyosis, permitting a correct diagnosis when genetic counselling has to be given in sporadic cases.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00412487
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 195
    Digitale Medien
    Digitale Medien
    The ultrastructure of congenital nevocytic nevi. I. Nevus cells in walls of blood vessels and lymphatics (1985)
    Springer
    Archives of dermatological research 278 (1985), S. 49-56 
    Details
    ISSN: 1432-069X
    Schlagwort(e): Congenital nevocytic nevi ; Nevus cells ; Blood vessels ; Lymphatics ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary As congenital nevocytic nevi have an increased risk of malignant degeneration, nevus-cell involvement in blood vessels and lymphatics is of particular interest. The present histological and ultrastructural studies revealed nevus-cell nests in the walls of venules in 1 out of 11 patients with medium-sized nevi, and in subcutaneous veins in 3 out of 8 patients with garment nevi. In all cases, the nests histologically consisted of benign-appearing subendothelial B-type cells. Ultrastructurally, the features of these nevocytes essentially corresponded to those of nevocytes in the surrounding area. In 1 patient with a garment nevus, in whom affected vessels of the lumbar area as well as of the neck were examined, the nevus-cell nests were exclusively situated between the endothelium and its basal lamina. These nevocytes appeared to be more electron dense, but had no unequivocally atypical features. In the region of these nests, the endothelium was often discontinuous; thus, the nevus-cells were in direct contact with the lumen. Some of these cells exhibited slight degenerative changes. The lymphatics were affected in 6 of the 18 cases of garment nevi and in 2 of the 11 cases of medium-sized nevi. The morphological findings were comparable to those for blood vessels. It is concluded that, in garment nevi, morphologically benign nevocytes may be carried off hematogenously as well as lymphogenously.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00412496
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 196
    Digitale Medien
    Digitale Medien
    The antral gastrin-producing cells in duodenal ulcer patients (1985)
    Springer
    Virchows Archiv 406 (1985), S. 271-277 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Cimetidine ; Duodenal ulcer ; Gastrin producing cells ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Ultrastructural examination of the antral G cells has been carried out on 11 patients with chronic duodenal ulcer, before and after treatment with a histamine H-2 - receptor antagonist (cimetidine 1 g/ day) for 8 weeks. The study demonstrated an increased area of the Golgi complex, rough endoplasmic reticulum and electron-dense granules, indicating increased G cell activity during treatment. An increased number of lysosomes was a constant feature during treatment. As an hypothesis we suggest that these lysosomes may participate in the secretory mechanism of human G cells, by destroying superfluous (Gastrin) components produced during hyperactivity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00704296
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 197
    Digitale Medien
    Digitale Medien
    Localisation of C-terminal gastrin immunoreactivity in gastrinoma cells (1985)
    Springer
    Virchows Archiv 406 (1985), S. 223-236 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Gastrin ; Gastrinomas ; Ultrastructure ; Immunogold technique
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Localisation of C-terminal gastrin immunoreactivity has been studied, using the immunogold staining procedure, on ultrathin sections of 6 human gastrinomas conventionally processed for electron microscopy. The specific labelling, whose density depended on the mean diameter of the gold marker, was restricted to endocrine secretory granules. However, in poorly differentiated cells from malignant tumours, a number of granules remained unreactive. The labelling pattern depended also on the functional state of each cell. The immunoreactive granules showed various morphological features. A moderate number of gold particles was demonstrated over the floccular content of the infrequent diagnostic G-type granules. Non-diagnostic round granules of varying size and electron density were prevalent in most cells; their usually strong immunostaining allowed immediate recognition of cell specificity. Dense granules which were large in size and angular in shape and present in one case, were also intensely labelled. In the same tumour, unequal labelling occurred over polymorphous, often elongated granules, of varying size. Granules of different types, including intermediate forms, could be found in the same cell, indicating a spectrum of granule maturation towards well-defined types of the fetal or adult normal tissues. The present methodology would help to identify gastrin-producing cells in prospective or retrospective electron microscopy studies of multihormonal endocrine tumours.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00737088
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 198
    Digitale Medien
    Digitale Medien
    Malignant peripheral neuroectodermal tumours of childhood and adolescence (1985)
    Springer
    Virchows Archiv 406 (1985), S. 351-365 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Neuroepithelioma ; Histology ; Immunohistochemistry ; Neuron-specific enolase ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Seventeen cases of malignant peripheral neuroectodermal tumour (MPNT) were studied by means of light microscopy, immunohistochemistry and electron microscopy. There were nine males and eight females. The mean age of the 17 patients was 10 years with a range of seven months to 20 years. The vast majority of tumours was located in the trunk. Histologically, they closely resembled Ewing's sarcoma, although minor differences were obvious. Special findings included ganglion cells and Flexner rosettes. In 10/11 cases positive staining for neuron-specific enolase (NSE) was obtained. Five of 10 tumours were positive for protein S-100. Three contained vimentin, two neurofilaments and one vimentin, neurofilaments and GFAP. Neurosecretory granules were noted in the three cases studied. Five patients died, three are alive with disease and five patients are alive without evidence of disease. It is concluded that these tumours form a homogeneous group, although the grade of differentiation varies. The prognosis in most cases is poor. Distinction from Ewing's sarcoma is possible by staining for NSE and by electron microscopy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00704304
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 199
    Digitale Medien
    Digitale Medien
    Ultrastructural study of glycogen-rich oxyphilic adenoma of the nasopharyngeal minor salivary gland (1985)
    Springer
    Virchows Archiv 407 (1985), S. 151-158 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Glycogen-rich adenoma ; Salivary gland ; Epithelial cell ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A glycogen-rich adenoma occurring in the minor salivary gland of the nasopharynx in a 41-year-old woman was studied ultrastrucrurally. The cytoplasm of the tumour cells was abundantly filled with glycogen particles. The tumour cells possessed many mitochondria, a great number of microvillous processes and microvilli and were joined to each other by desmosomes. These findings suggest that this adenoma is of salivary duct epithelial origin most probably from storing striated ductal cells, and is a variant of monomorphic oxyphilic adenoma.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00737072
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 200
    Digitale Medien
    Digitale Medien
    Multicentric angiosarcoma (Kaposi's sarcoma) (1985)
    Springer
    Virchows Archiv 408 (1985), S. 29-41 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Kaposi's sarcoma ; AIDS ; Ultrastructure ; Immunohistology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Comparison of idiopathic Kaposi's sarcoma in Europe and Africa and Kaposi's sarcoma in connection with AIDS shows an identical morphological appearance in all three types. Ultrastructural and immunohistological investigations indicate that the tumour originates from the endothelial cells of proliferating capillaries and is therefore a vascular tumour. The clinical course and the sites of manifestation differ slightly in idiopathic cases and those occurring in connection with AIDS. This effect may be determined by the general condition of the patient, the state of immune deficiency and the influence of opportunistic infections.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00739960
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...