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  • 1985-1989  (207)
  • 1965-1969
  • 1985  (207)
  • Ultrastructure  (112)
  • pharmacokinetics  (95)
  • 101
    Electronic Resource
    Electronic Resource
    Clinical pharmacokinetics of 6-hour infusion of high-dose methotrexate. Preliminary trial of monitoring high infusion doses (1985)
    Springer
    European journal of clinical pharmacology 28 (1985), S. 457-462 
    Details
    ISSN: 1432-1041
    Keywords: methotrexate ; osteosarcoma ; high parenteral dose ; pharmacokinetics ; drug monitoring ; computer prediction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Methotrexate (MTX) in serum was measured by RIA in 12 cancer patients receiving high doses of MTX (2 to 8 g/m2) in 6 hour infusions 69 treatments were studied. The peak serum level was proportional to the dose administered and was always greater than 10−4 M. 2 elimination phases were seen: the first had a mean half-life of 2.36 h and the second a mean half-life of 16.14 h. 24 hours after beginning the infusions there were very large variations in individual serum concentrations of MTX, from 2.4 10−6 M to 1.9 10−5 M by 24 h after 8 g/m2. To control these variations, a mathematical model for prediction of the individual pharmacokinetic pattern of a 6 hour-infusion of high-dose MTX by kinetic analysis of a low-test dose is proposed. A program was created for an Apple III computer using toxic and therapeutic serum levels of MTX selected by the clinician. The computer program is adaptable to any infused substance for variable infusion times, thus introducing new advances over existing methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00544367
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  • 102
    Electronic Resource
    Electronic Resource
    The influence of ascites on the pharmacokinetics of piretanide in cirrhotic patients (1985)
    Springer
    European journal of clinical pharmacology 28 (1985), S. 581-583 
    Details
    ISSN: 1432-1041
    Keywords: piretanide ; liver cirrhosis ; ascites ; bioavailability ; pharmacokinetics ; diuretic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of piretanide, a new loop diuretic, were studied in seven patients with severe liver disease before and after resolution of ascites. The time to maximum concentration was significantly prolonged by the presence of ascites. Tmax after relief of ascites was similar to that seen for normal volunteers. Area under the curves, bioavailability, volumes of distribution and elimination half-lives did not change after resolution of the ascites: two patients in whom diuretic resistant ascites occurred showed similar pharmacokinetics to that of the diuretic responders. Reduced responsiveness to piretanide therapy in patients with gross ascites does not appear to be the result of decreased bioavailability.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00544070
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  • 103
    Electronic Resource
    Electronic Resource
    Acute and subacute effects on psychomotor performance of femoxetine alone and with alcohol (1985)
    Springer
    European journal of clinical pharmacology 28 (1985), S. 641-647 
    Details
    ISSN: 1432-1041
    Keywords: Femoxetine ; alcohol interaction ; psychomotor performance ; pharmacokinetics ; amitriptyline ; plasma 5HT
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effects on human psychomotor performance of femoxetine (FEMO), a 5-hydroxytryptamine-selective antidepressant, alone and in combination with alcohol (EtOH) were compared with those of amitriptyline (AMI) and placebo in a controlled double-blind crossover trial in 11 student volunteers. Objective measurements (body sway, choice reaction, flicker fusion, tracking, nystagmus, digit symbol substitution, backwards recall) and subjective self-assessment (visual analogue scales, reporting of side-effects) were done after single doses of FEMO, AMI and placebo, and subacute administration of FEMO and placebo. Single doses of 200 mg FEMO did not impair psychomotor performance, but 50 mg AMI did so in several respects. AMI but not FEMO increased the objective and subjective effects of EtOH. After FEMO 600 mg/d for 10 days almost no objective difference from placebo was noted, although mild sedation at home was reported as a side-effect. FEMO either did not increase or slightly decreased the effect of EtOH on reactive and co-ordination skills. The plasma concentrations of FEMO varied widely from 0 to 156 ng/ml, as in previous clinical trials but reduced a blood 5-hydroxytryptamine concentration in each subject indicating an effect of FEMO on serotoninergic mechanisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00607908
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  • 104
    Electronic Resource
    Electronic Resource
    Disopyramide pharmacokinetics in patients with acute myocardial infarction (1985)
    Springer
    European journal of clinical pharmacology 28 (1985), S. 45-51 
    Details
    ISSN: 1432-1041
    Keywords: disopyramide ; myocardial infarction ; antiarrhythmic agent ; pharmacokinetics ; protein binding ; intravenous administration ; oral administration ; gastro-intestinal absorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary To study the effects of acute myocardial infarction on the pharmacokinetics of disopyramide a single oral dose of disopyramide base (200 mg) was administered to 6 patients with myocardial infarction both in the acute (Study I) and recovery (Study II) phases. An intravenous tracer dose of14C-disopyramide (2.5 µg/0.3 mg) was given simultaneously with the oral dose. On the basis of the intravenous tracer data, the volume of distribution, binding to plasma proteins, total plasma clearance, renal clearance and elimination half-life of disopyramide and mono-N-dealkyl disopyramide were the same in Studies I and II. The peak serum concentrations of disopyramide after oral dosing in Studies I and II were 2.6±1.2 (SEM) and 6.4±1.9 µg/ml, respectively (p〈0.05), the peak times 3.29±1.22 and 1.21±0.39 h (N.S.) and the AUCINF 38.0±7.7 and 60.7±9.9 µg·h·ml−1 (p〈0.05). The recovery of disopyramide in urine over 3 days averaged 46% and 47% of dose, and that of mono-N-dealkyl disopyramide 22% and 16% of the dose, respectively. Thus, the gastrointestinal absorption of disopyramide was disturbed, resulting in low plasma concentrations after oral dosing, whereas the elimination of disopyramide was unaltered in the acute phase of myocardial infarction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00635707
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  • 105
    Electronic Resource
    Electronic Resource
    Atenolol inhibits the elimination of disopyramide (1985)
    Springer
    European journal of clinical pharmacology 28 (1985), S. 41-43 
    Details
    ISSN: 1432-1041
    Keywords: disopyramide ; atenolol ; pharmacokinetics ; drug interaction ; ischaemic heart disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effect of atenolol on the total elimination of disopyramide and its main dealkylated metabolite was studied in 6 patients and 3 volunteers. During administration of 50 mg atenolol b.i.d. the clearance of disopyramide decreased significantly (p〈0.02) from 1.90±0.71 (X±SD) to 1.59±0.68 ml/kg/min, while its half-life, concentration of the metabolite, and the volume of distribution remained unchanged. The reduction in the clearance of disopyramide by atenolol might contribute to the alleged pharmacodynamic interaction between disopyramide and β-blocking drugs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00635706
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  • 106
    Electronic Resource
    Electronic Resource
    Pharmacokinetics and pharmacodynamics of procyclidine in man (1985)
    Springer
    European journal of clinical pharmacology 28 (1985), S. 73-78 
    Details
    ISSN: 1432-1041
    Keywords: procyclidine ; Kemadrin ; pharmacokinetics ; pharmacodynamics ; humans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics and pharmacodynamics of procyclidine (10 mg) after oral and intravenous administration were studied in six healthy volunteers. Treatment order was randomised and the study was placebo-controlled and conducted blind. After oral dosing the mean peak plasma concentration was 116 ng/ml and mean bioavailability was 75%. After both oral and intravenous dosing the mean values for the volume of distribution, total body clearance and plasma elimination half-life of procyclidine were in the order of 1 l/kg, 68 ml/min and 12 h respectively. Autonomic effects were maximal within 0.5 h of intravenous administration and at about 1–2 h after oral dosing. Significant effects on pupil diameter, visual near point, salivary secretion and heart rate occurred after intravenous treatment and similar but less marked effects occurred after the oral dose. Significant autonomic effects were still detectable 12 h after both forms of treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00635711
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  • 107
    Electronic Resource
    Electronic Resource
    Pharmacokinetics of oral moclobemide in healthy human subjects and effects on MAO-activity in platelets and excretion of urine monoamine metabolites (1985)
    Springer
    European journal of clinical pharmacology 28 (1985), S. 89-95 
    Details
    ISSN: 1432-1041
    Keywords: moclobemide ; Ro 11-1163 ; pharmacokinetics ; bioavailability ; MAO activity in platelets ; monoamine metabolites in urine ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The plasma concentrations of the MAO-inhibitor moclobemide (Ro 11-1163) were determined in six healthy male subjects after oral (tablets) administration. Effects on MAO activity in platelets and excretion of monoamine metabolites in urine were investigated. The design of the study was a double-blind cross-over study with single oral doses of placebo, 50, 100 and 200 mg of moclobemide. The elimination profile of the drug showed that the half life of the unchanged drug ranged between 1 and 2 h except in one subject with a half-life of about 4 h. The mean bioavailability calculated using flow model concepts was F=0.43 after 50 mg, F=0.47 after 100 mg and F=0.59 after 200 mg. The outlier with a t1/2 of 4 h was found to have a bioavailability of more than 0.80 after all 3 doses. The slightly increasing bioavailability with higher doses was interpreted as evidence of saturable hepatic first-pass elimination of the drug. MAO activity in platelets was measured before and 2, 6 and 24 h after drug administration. No inhibition of platelet MAO was obtained at any point in time or dose level, as to be expected since moclobemide preferentially inhibits MAO A. Urine excretion of the monoamine metabolites homovanillic acid (HVA), dihydroxyphenylacetic acid (DOPAC), 3-methoxy-4-hydroxy-phenylglycol (MOPEG) and 5-hydroxyindoleacetic acid (5-HIAA) was followed during 48 h after placebo, 50 and 200 mg of moclobemide. Time but not dose contributed significantly to the variability in excretion of the monoamine metabolites. An apparent reduction of HVA and DOPAC levels was obtained in the early phase after the administration of 200 mg of moclobemide. In 1 subject with a mild drug reaction a pronounced decrease in the levels of all the metabolites was obtained. In the other 5 subjects, the compound was very well tolerated with a few reported side-effects like increased activity, somnolence or sweatings. There was a slight but significant increase in blood pressure following 50 and 100 mg but not 200 mg of moclobemide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00635714
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  • 108
    Electronic Resource
    Electronic Resource
    Pharmacokinetics of sulphinpyrazone and its major metabolites after a single dose and during chronic treatment (1985)
    Springer
    European journal of clinical pharmacology 28 (1985), S. 97-103 
    Details
    ISSN: 1432-1041
    Keywords: sulphinpyrazone ; metabolism ; single dose ; chronic treatment ; pharmacokinetics ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of sulphinpyrazone and its major metabolites (sulfide, sulfone, p-hydroxysulfone and p-hydroxy-sulphinpyrazone) were investigated in 9 volunteers after a single oral dose as well as after chronic treatment for 23 days. Chronic administration of sulphinpyrazone, in comparison with a single oral dose, led to significant changes in plasma AUC (115.86 to 42.90 mg/l·h), in renal clearance (1.06 to 1.80l/h), in hepatic intrinsic clearance (319.0 to 598.0l/h), and in the unbound fraction in plasma 1.15 to 1.69%) and in tissue (2.73 to 1.31%). The volume of distribution changed from 20.24 to 52.041. The steady state concentrations predicted from the single dose were significantly higher than the values found after chronic treatment. The results suggest that sulphinpyrazone induces its own metabolism. The metabolism of the sulfone, p-hydroxysulfone and the p-hydroxy-sulphinpyrazone to further degradation products was also induced. Chronic treatment with sulphinpyrazone reduced the plasma AUC of the sulfide and caused a decrease in its elimination half-life (20.9 to 14.3 h). Since considerable amounts of the sulfide are formed in the G.I. tract, it is suggested that besides the induction of metabolism, bacteria which reduce sulphinpyrazone to the sulfide may also be responsible for the observed pharmacokinetic changes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00635715
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  • 109
    Electronic Resource
    Electronic Resource
    Deconvolution applied to the kinetics of extracorporal drug removal. Haemodialysis of cefsulodin (1985)
    Springer
    European journal of clinical pharmacology 29 (1985), S. 503-509 
    Details
    ISSN: 1432-1041
    Keywords: deconvolution ; haemodialysis ; cefsulodin ; extracorporal drug removal ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A novel approach to the evaluation of the kinetics of drug removal by an extracorporal device (ECD), e.g., haemodialysis, haemofiltration, and haemoperfusion, is presented. The rate and extent of extracorporal drug removal (ECR) are determined by deconvolution. The proposed method is model independent in the sense that no specific models of corporal or extracorporal disposition are required. The estimation of various derived functions and parameters useful for describing ECR such as clearance and fractional drug removal are facilitated by the technique. The kinetics of cefsulodin elimination by haemodialysis in 3 patients were evaluated using the deconvolution approach. The results indicated that cefsulodin was dialyzable with ∼50% of the drug in the body removed by haemodialysis over 3–4 h.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00613469
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  • 110
    Electronic Resource
    Electronic Resource
    A case of lipogranulomatosis Farber: some clinical and ultrastructural aspects (1985)
    Springer
    European journal of pediatrics 143 (1985), S. 203-208 
    Details
    ISSN: 1432-1076
    Keywords: Farber disease ; Lipogranulomatosis ; Acid ceramidase deficiency ; Arthropathy ; Hoarseness ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A 20-month-old girl showed typical clinical signs of Farber disease: hoarseness since birth, and periarticular subcutaneous painful nodules. Complete deficiency of acid ceramidase activity was found in cultured skin fibroblasts. An electron microscopic examination of a dermal nodule disclosed pathognomonic tubular inclusions in histiocytes. In epidermal cells zebra-body-like and needle-like lysosomal inclusions were found. Their ultrastructure is different from that of the intrahistiocytic lysosomal inclusions. Probably three clinical types of Farber disease may be distinguished according to the symptomatology and the course of the discase: a severe type, an intermediate type and a relatively mild type. The activity of acid ceramidase does not correlate with prognosis of the disease, while a correlation between first appearance of dermal nodules and clinical course appears likely.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00442139
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  • 111
    Electronic Resource
    Electronic Resource
    Study on the micromorphology of Mycobacterium leprae (1985)
    Springer
    Archives of dermatological research 277 (1985), S. 220-224 
    Details
    ISSN: 1432-069X
    Keywords: Mycobacterium leprae ; Ultrastructure ; Fixation methods
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The micromorphology of Mycobacterium leprae is described. After fixation with osmium tetroxide supplemented with calcium ions, the cell wall was seen to be composed of three layers; the cytoplasmic membrane exhibited the architecture of an elementary membrane. The mesosomes were best visualized after fixation with glutaraldehyde; they were sometimes in contact with the nuclear equivalent. Only one sort of phosphate body was found. The nucleoid was best visualized after fixation with osmium tetroxide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00404320
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  • 112
    Electronic Resource
    Electronic Resource
    Ultrastructural identification of somata and neural processes immunoreactive to antibodies against glutamic acid decarboxylase (GAD) in the dorsal lateral geniculate nucleus of the cat (1985)
    Springer
    Experimental brain research 59 (1985), S. 151-165 
    Details
    ISSN: 1432-1106
    Keywords: Lateral geniculate nucleus ; GAD ; GABA ; Inhibition ; Immunocytochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cat dorsal lateral geniculate nucleus (LGN) was examined at the light- and electron-microscopic level after immunocytochemistry for GAD (the synthesizing enzyme of the inhibitory neurotransmitter GABA), to identify cells and processes with GAD-like immunoreactivity. GAD-positive perikarya were distributed throughout the A and C laminae, constituting a moderate proportion of cells in the LGN. Labeled cells were characterized by small size, scant cytoplasm, relatively large nuclei with common indentations, small mitochondria, few organelles and few strands of rough endoplasmic reticulum. Unlabeled cells were of large, medium and small size. GAD-positive terminals were identified as F1 and F2 types (Guillery's nomenclature) on the basis of their synaptic relations and ultrastructure. Labeled F2 terminals were postsynaptic to retinal (RLP) boutons and presynaptic to unlabeled dendrites in synaptic glomeruli. Labeled F1 terminals made synapses on unlabeled somata and dendrites, and on labeled dendrites and F2 terminals. Presumably, most labeled F1 terminals originate from GABAergic perigeniculate axons. Retinal (RLP) and cortico-geniculate (RSD) boutons remained unlabeled in the reative zone. These terminals made synapses with labeled and unlabeled dendrites and with labeled F2 boutons. In conjunction with previous studies on GAD-positive cells in the perigeniculate nucleus, these results provide immunocytochemical and morphological evidence suggesting that the GABAergic intrinsic and extrinsic (perigeniculate) interneurons mediate the different inhibitory phenomena which occur in relay cells of the cat LGN. The ultrastructural features and synaptic relations of GABAergic cells and processes in the cat LGN are similar to those of equivalent neural elements in the LGN of rat and monkey, suggesting general principles of organization and morphology for GABAergic neurons in the thalamus of different mammals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237675
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  • 113
    Electronic Resource
    Electronic Resource
    Axonal and myelin lesions inβ-mannosidosis: Ultrastructural characteristics (1985)
    Springer
    Acta neuropathologica 65 (1985), S. 293-299 
    Details
    ISSN: 1432-0533
    Keywords: β-mannosidosis ; Axonal spheroids ; Myelin deficit ; Oligodendrocytes ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural changes in central nervous system (CNS) white matter of three goats affected withβ-mannosidosis were analyzed to further define characteristics and pathogenesis of axonal and myelin abnormalities. The variations in myelin association and contents of axonal spheroids were delineated. The occurrence of spheroids in a 96/150-day fetus documented the early development of these axonal lesions. In regions of severe myelin deficits, the presence of apparently normal axons and a reduction in the number of oligodendrocytes were confirmed. Many remaining cells in myelin-deficient regions were characterized by dark, vacuolated cytoplasm. The occurrence of internodes with myelin sheaths adjacent to internodes without myelin sheaths suggested that an axonal defect is not primarily responsible for the absence of myelin sheaths. A mild myelin deficit in the spinal cord was indicated by the presence of unmyelinated axons. Except for occasional mild cytoplasmic vacuolation, the spinal cord glial cells appeared relatively normal. The findings presented here are consistent with the hypothesis that an oligodendrocyte defect, expressed by regional differences, is a major factor in the pathogenesis of myelin deficiency inβ-mannosidosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687011
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  • 114
    Electronic Resource
    Electronic Resource
    Ultrastructural and ultracytochemical identification of the small granules in basophils from human and animals (1985)
    Springer
    Annals of hematology 51 (1985), S. 385-392 
    Details
    ISSN: 1432-0584
    Keywords: Ultrastructure ; Ultracytochemistry ; Basophils ; Small granules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The small granules in the basophils obtained from humans and animals were compared ultrastructurally and cytochemically. Cytochemically, there were no qualitative differences among the small granules in the species examined. The small granules in humans, guinea pigs and rabbits were approximately 0.16–0.22 μm, 0.15–0.17 μm, and 0.12–0.16 μm, in diameter, respectively. In all species small granules had a single unit membrane and contained some amorphous material. In immature cells many of the small granules were distributed near the Golgi apparatus, while in the mature cells many of them were found around the periphery of the cell. There were no morphological or cytochemical differences between the small granules of the immature cells and those of the mature cells. The negative reaction in the dialysed iron and high iron diamine methods showed that the small granules did not have acid mucopolysaccharides or sulfated glycoconjugates. The strong reaction of the small granules of all species to the periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) test, which was especially prominent in rabbit, showed that the small granules have many periodate-reactive neutral glycoconjugates but no acidic glycoconjugates. Enzyme cytochemistry revealed that the small granules are negative for peroxidase and catalase but positive for acid phosphatase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00320724
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  • 115
    Electronic Resource
    Electronic Resource
    Severe polyneuropathy in tangier disease mimicking syringomyelia or leprosy (1985)
    Springer
    Journal of neurology 232 (1985), S. 283-294 
    Details
    ISSN: 1432-1459
    Keywords: Tangier disease ; Polyneuropathy ; Ultrastructure ; Biopsy findings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Polyneuropathy in Tangier disease can be divided into three clinical types. The most severe form (type III) with a syringomyelia-like syndrome has been described in three cases only. Here, a fourth case of this type is presented. Because of unusual trophic disturbances even leprosy was suspected. Electrodiagnostic findings, including evoked cerebral potentials in this case, were suggestive of a generalized neuropathy with some degree of primary or secondary demyelination and implied possible impairment of central structures. Sural nerve biopsy, including electron microscopy and quantitative analysis, revealed a predominant reduction of smaller myelinated and unmyelinated fibres. The main morphological feature was the abundance of abnormal non-membrane-bound vacuoles in Schwann cells, mostly of the unmyelinated type, and in some endoneurial fibroblasts, macrophages and perineurial cells. There was no inverse relationship between lipid vacuoles and axons in Schwann cell complexes as supected by others. An excess of endoneurial collagen as well as an increased fascicular area were obvious. In five skin biopsy specimens of different regions typical vacuoles were noted in Schwann cells, histiocytes, nevus cells, and rarely in perineurial cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00313867
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  • 116
    Electronic Resource
    Electronic Resource
    Binding and disposition of sulfisoxazole in alcoholic cirrhosis (1985)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 13 (1985), S. 1-12 
    Details
    ISSN: 1573-8744
    Keywords: sulfisoxazole ; cirrhosis ; pharmacokinetics ; volume of distribution protein binding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The disposition of sulfisoxazole was studied in six male patients hospitalized with biopsy-proven Laennec's alcoholic cirrhosis and six normal, healthy volunteers. Four of the patients were restudied at a time their liver disease had improved clinically. On the average, compared to the normal group, the metabolism of sulfisoxazole (clearance values with respect to unbound concentration values) appears to be unaltered for the cirrhotic patients. For patients with alcoholic cirrhosis having normal renal function for age and weight, the renal elimination of sulfisoxazole was normal For those subjects with decreased renal function, the renal clearance of sulfisoxazole appeared to be disproportionately decreased, as evidenced by a lower-than-normal sulfisoxazole renal clearance-to-creatinine clearance values. The apparent steady-state volume of distribution of unbound sulfisoxazole was not altered in cirrhotic patients when compared to normal subjects, while the apparent volume of distribution of total drug increased by more than what could be expected from protein binding changes alone. The elimination rate constant did not differ from values found in normals. These data suggest that the total binding capacity of sulfisoxazole in cirrhotic patients is not different from that of normal subjects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01073653
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  • 117
    Electronic Resource
    Electronic Resource
    A quantitative study of blood-brain barrier permeability ultrastructure in a new rat glioma model (1985)
    Springer
    Acta neuropathologica 67 (1985), S. 96-102 
    Details
    ISSN: 1432-0533
    Keywords: Blood-brain barrier ; Morphometry ; Ultrastructure ; Experimental glioma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cerebral edema, a major complication of tumors in the brain, is the result of an alteration in the blood-brain barrier (B-BB). The vascular ultrastructural changes that underlie edema formation have been described in a variety of tumors. Interendothelial junction abnormalities, fenestrations, and large numbers of tubulo-vesicular profiles in the tumor vascular endothelium have been presumed to represent permeability routes that permit the escape of serum constituents into the tumor, from where they flow into the surrounding brain. Descriptive studies do not provide information on the relative frequency of these presumptive permeability routes. In the study reported here we have quantified ultrastructural features associated with the B-BB in the vessels of an experimental glioma in rat. We found that approximately 60% of the tumor vessel profiles have junctional abnormalities and 30% have one or more fenestrations. The density of tubulo-vesicular profiles, however, was not increased. In addition, tumor vessel walls were thicker than normal vessels of the same caliber and the mitochondrial density was in the range of that for non-barrier vessels. Vessels in peritumoral regions were not altered in any of the parameters measured.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688129
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  • 118
    Electronic Resource
    Electronic Resource
    Ultrastructure of cerebellar hemangioblastoma (1985)
    Springer
    Acta neuropathologica 67 (1985), S. 6-12 
    Details
    ISSN: 1432-0533
    Keywords: Cerebellar hemangioblastoma ; Ultrastructure ; Stromal cells ; Cytoplasmic process ; Adjacent brain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Five cases of hemangioblastoma were studied by electron microscopy with particular attention to the stromal cells and their surrounding structures. Most of the stromal cells of the tumor had abundant clear cytoplasm containing rough endoplasmic reticulum, mitochondria, scattered fibrils, and large lipid inclusions. They were usually aggregated without intervening cells. In the perivascular areas, their sufaces facing the perivascular collagen were surrounded by basal lamina. Their apposed cell membranes had occasional adhesive devices. Occasional, long, apparently cylindrical processes of the stromal cell cytoplasm were observed in some cases. These processes contained intermediate filaments of undetermined nature and microtubules. In the border zone between the tumor and the surrounding brain, the stromal cells were occasionally surrounded by narrow sheets of dark cell processes containing fibrils and glycogen granules, consistent with astrocytic processes. Altered neuronal elements were also observed inthis area.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688119
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  • 119
    Electronic Resource
    Electronic Resource
    Blood vessel ultrastructure in the chick optic tectum developing under chronic hypoxia conditions (1985)
    Springer
    Acta neuropathologica 67 (1985), S. 242-246 
    Details
    ISSN: 1432-0533
    Keywords: Chick embryo ; Optic tectum ; Blood vessels ; Ultrastructure ; Hypoxia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The maturation process of blood vessels has been ultrastructurally investigated in the optic tectum of chick embryos kept in a condition of aerogenic hypoxia and of chickens born from fertilized eggs incubated under hypoxia but kept in the open air after hatching. By comparing the fine structure of the intratectal vessels of chick embryos exposed to hypoxia to that of embryos developed under normal conditions, the conclusion has been drawn that O2 deprivation does not prevent the temporal sequence of appearance and/or differentiation of the various vascular wall components (endothelium, endothelial basement lamina, pericytes, perivascular glia), but it produces, at least in a part of the latter, modifications, the type and degree of which apparently depend upon hypoxia duration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687808
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  • 120
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    Gliosarcomas: Histological, immunohistochemical, ultrastructural, and tissue culture studies (1985)
    Springer
    Acta neuropathologica 67 (1985), S. 201-210 
    Details
    ISSN: 1432-0533
    Keywords: Gliosarcoma ; GFAP ; Factor VIII/RAg ; Ulex europaeus I agglutinin ; Ultrastructure ; Weibel-Palade bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thirty-nine cases of gliosarcomas, two initiating as fibrosarcomas, 25 as mixed gliomas and sarcomas, and 12 as anaplastic gliomas with secondary sarcomas, were studied by light microscopy, immunohistochemistry, using GFAP, factor VIII/RAg, andUlex europaeus I agglutinin (UEA I), electron microscopy and tissue culture. GFAP was found variably positive in the glial areas; F VIII/RAg and UEA I, markers of both normal and neoplastic endothelial cells and their derivatives, were found in vessels of both gliomatous and sarcomatous parts of GS, less intensive in hyperplastic glomeruloid structures and, with decreasing intensity, in adjacent fibrosarcomatous areas, while UEA I, giving stronger reaction than F VIII/RAg, was occasionally demonstrated in sarcomatous cells. In vitro studies confirmed previous data of a separate growth of glial and mesenchymal cells with a divergent migratory speed. Electron microscopy demonstrated the frequent close admixture of glial and mesenchymal tumor cells, which showed the feature of either fibrosarcoma or angiosarcoma. The frequent resemblance of the latter with endothelial cells was supported by the occasional demonstration of Weibel-Palade-like bodies in both vascular endothelial and adjacent sarcomatous cells. These observations confirm the hypothesis that at least part of the sarcomatous components in many GS originate from vascular endothelial proliferation and obviously represent the final stage of a process starting with the endothelial hyperplasia in anaplastic gliomas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687802
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  • 121
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    Retinal ultrastructure of neuronal ceroid-lipofuscinosis in the Dalmatian dog (1985)
    Springer
    Acta neuropathologica 68 (1985), S. 224-229 
    Details
    ISSN: 1432-0533
    Keywords: Dalmatian dogs ; Lipopigments ; Retina ; Retinopathy ; Ultrastructure ; Ceroidlipofuscinosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural studies of the retinae in two NCL-affected Dalmatian dogs revealed ubiquitous accumulation of lipopigments in numerous cell types of the retina, the fine structure of which closely resembled that seen in NCL-affected English setters. Photoreceptors and other retinal cell types were largely intact. These findings show that the retinal involvement in NCL of our Dalmatian dogs is identical to that of NCL-affected English setters. It also shows that in canine NCL a severe retinopathy, regularly encountered in human childhood NCL, does not develop. Thus, the NCL of Dalmatian dogs —and English setters — represents a reliable model to study human NCL, but for human retinopathia pigmentosa perhaps only at its earliest stage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690199
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  • 122
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    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
    Keywords: Lamellar ichthyosis ; Autosomal-dominant inheritance ; Ultrastructure ; Transforming cells ; Genetic counselling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00412487
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  • 123
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    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
    Keywords: Congenital nevocytic nevi ; Nevus cells ; Blood vessels ; Lymphatics ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00412496
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  • 124
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    Pharmacokinetics of serum phosphocreatine in man, dog, and rabbit (1985)
    Springer
    Bulletin of experimental biology and medicine 100 (1985), S. 1558-1560 
    Details
    ISSN: 1573-8221
    Keywords: phosphocreatine ; pharmacokinetics ; man ; experimental animals ; intravenous infusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00836165
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  • 125
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    Early ultrastructural adaptive changes of ileal enterocytes after proximal small bowel resection as determined morphometrically (1985)
    Springer
    Research in experimental medicine 185 (1985), S. 259-268 
    Details
    ISSN: 1433-8580
    Keywords: Small bowel resection ; Ultrastructure ; Morphometry ; Intestinal adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The aim of the present study was to evaluate in terms of quantitative measurements whether the well-known histomorphological and functional adaptive changes in the intestinal mucosa after small bowel resection are accompanied by alterations on the ultrastructural level. Therefore, samples of the ileal remnants after a 60% proximal resection were processed for ultrastructural evaluation and analyzed employing point counting planimetry and direct measurements. Microvillus surface area increased from the bottom of the crypts to the villus tips in both resected and sham-operated animals. This increase in microvillus surface area from the crypt to the villus was significantly less pronounced after proximal resection, while there were no changes in the crypt compartment. No significant differences of the relative areas of the nuclei, mitochondria, and the rough endoplasmic reticulum were observed when comparing the different positions along the villus crypt axis in normal and hyperplastic mucosa. In agreement with functional and enzyme histochemical results, these ultrastructural findings provide further evidence for an altered pattern of enterocyte maturation after proximal resection, which is most probably due to an increase in the migration rate of the enterocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01851950
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  • 126
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    Massive ribonucleoprotein bodies in gametophyte vegetative cells of the mossTimmiella barbuloides (Brid.) Moenk (1985)
    Springer
    Protoplasma 127 (1985), S. 204-211 
    Details
    ISSN: 1615-6102
    Keywords: Biogenesis ; Cytochemistry ; Ribonucleoprotein bodies ; Ribosomes ; Timmiella barbuloides (Musci) ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Vegetative cells of the gametophyte phase of the mossTimmiella barbuloides (Pottiales) are characterized by large cytoplasmic bodies of spherical shape (SBs) whose ribonucleoprotein composition is cytochemically demonstrated. SBs seem to be derived from massive aggregation of cytoplasmic ribosomes, with possible participation by rough endoplasmic reticulum elements. SBs have been found in stereids, parenchymatous cells and young hydroids of the gametophyte stem, and in euricysts of the leaf nerve. The SBs develop early in the course of cell differentiation and, once formed, persist until advanced stages of cell senescence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01276264
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  • 127
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    Ultrastructural aspects of cytoplasmic male sterility inPetunia hybrida (1985)
    Springer
    Protoplasma 127 (1985), S. 230-240 
    Details
    ISSN: 1615-6102
    Keywords: Cytoplasmic male sterility ; Mitochondria ; Petunia hybrida ; Tapetum ; Ultrastructure ; Vacuoles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Anther development of isogenic male fertile and cytoplasmic male sterile types ofPetunia hybrida cv. Blue Bedder is studied by electron microscopy. First deviation in sporogenesis of the sterile type, is observed during leptotene stage of the meiocytes. Initial aberration is represented by the presence of large vacuoles in the cytoplasm of the tapetal cells. These vacuoles reveal the first aspects of degeneration; no other ultrastructural differences are observed. Vacuolation is accompanied by the condensation of cytoplasmic organelles. The tapetal cells become distorted and ultrastructural aberrations in mitochondria do occur. The mitochondria elongate and contain several tubular cristae. Substantial evidence suggests, that cytoplasmic male sterility in petunia is encoded by the mitochondrial genome (Boeshore el al. 1983). However, before degeneration becomes manifest, no consistent ultrastructural differences in mitochondrial organization are observed. Abortion of the tapetum and the sporogenous tissue in cytoplasmic male sterile plants, generally follows a corresponding pattern. Ultimately, the cells are highly distorted, the nucleus is disrupted and the cytoplasm disorganized. Mitochondria and plastids degenerate and many lipid droplets are present.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01276267
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  • 128
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    Myoendothelial junctions in blood vessels of a teleost (Prochilodus scrofa) pancreas and caeca (1985)
    Springer
    Protoplasma 128 (1985), S. 224-226 
    Details
    ISSN: 1615-6102
    Keywords: Blood vessels ; Myoendothelial junctions ; Teleosts ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Close contacts between endothelial and smooth muscle cells in teleost (Prochilodus scrofa) blood vessels are described for the first time in the present study. More frequently are seen finger-like, club-shaped or foot-like endothelial processes that come into close contact with the plasma membrane of a smooth muscle cell. Rarely, some myoendothelial contacts occur between the finger-like protrusions that arise from both the endothelial and from the smooth muscle cells. The functional significance of the myoendothelial connection is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01276345
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  • 129
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    Cytochemical and X-ray microanalysis studies of intracellular calcium pools in scale-bearing cells of the coccolithophoridEmiliania huxleyi (1985)
    Springer
    Protoplasma 124 (1985), S. 1-9 
    Details
    ISSN: 1615-6102
    Keywords: Calcium localization ; Coccolithophorids ; Emiliania huxleyi ; Pyroantimonate ; Ultrastructure ; X-ray microanalysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Emiliania huxleyi is a coccolithophorid with a life cycle including a stage characterized by the occurrence of a scale-bearing cell type. The scales are composed of organic material and are produced in the cisternae of the Golgi apparatus. The present report deals with the ultrastructural calcium localization in scale-bearing cells using cation-precipitating agents. Cations were precipitated either with potassium pyroantimonate alone or according to a combined procedure in which cells are treated first with potassium oxalate, or potassium carbonate, or potassium phosphate, and then with potassium pyroantimonate. The distribution of electron-opaque deposits was the same when visualized by all four techniques. The most extensive deposits occurred in the Golgi apparatus, the “peripheral space” (a cellular compartment totally encompassing the protoplast), the multivesicular bodies, and the cell vacuole. X-ray microanalysis revealed that calcium was a constituent of the electron-opaque deposits. The uptake and transport of calcium, as universal functions of the Golgi apparatus, are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01279719
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  • 130
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    Ultrastructural studies on plastids of generative and vegetative cells inLiliaceae 3. Plastid distribution during the pollen development inGasteria verrucosa (Mill.) Duval (1985)
    Springer
    Protoplasma 124 (1985), S. 123-129 
    Details
    ISSN: 1615-6102
    Keywords: First pollen mitosis ; Gasteria verrucosa ; Male plastid inheritance ; Pollen development ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This paper describes the development of pollen grains ofGasteria verrucosa from the late microspore to the mature two-cellular pollen grain. Ultrastructural changes and the distribution of plastids as a result of the first pollen mitosis have been investigated using light and electron microscopy. The microspores as well as the generative and the vegetative cell contain mitochondria and other cytoplasmic organelles during all of the observed developmental stages. In contrast, the generative cell and the vegetative cell show a different plastid content. Plastids are randomly distributed within the microspores before pollen mitosis. During the prophase of the first pollen mitosis the plastids become clustered at the proximal pole of the microspore. The dividing nucleus of the microspore is located at the distal pole of the microspore. Therefore, the plastids are not equally distributed into both the generative and the vegetative cell. The possible reasons for the polarization of plastids within the microspore are briefly discussed. The lack of plastids in the generative cell causes a maternal inheritance of plastids inGasteria verrucosa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01279731
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  • 131
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    Structure and histochemistry of the extrafloral nectary ofAcacia terminalis (Salisb.) MacBride (Leguminosae, Mimosoideae) (1985)
    Springer
    Protoplasma 127 (1985), S. 21-30 
    Details
    ISSN: 1615-6102
    Keywords: Acacia terminalis ; Extrafloral nectary ; Histochemistry ; Secretion ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The extrafloral nectary ofAcacia terminalis is of the flat type and is located on the adaxial surface of the petiole of the bipinnate leaf. The secretory area is restricted to the base of the trough and no gaps or pores were detected by staining with vital dyes. Between the vascular bundles beneath the nectary and the surface cuticle there were three cell types. The cells of the flanking zone adjacent to the vascular bundles did not appear to be producing secretion whereas the cells of the glandular and secretory zones were secreting. The cells of the glandular zone were elongated whereas those of the surface secretory zone were spherical. Both had endoplasmic reticulum and Golgi bodies with secretory vesicles which were observed in close association with the plasmalemma. Secretion accumulated in the intercellular spaces of the glandular zone cells and forced the cells of the secretory zone apart. Symplastic contact was maintained in all cell types by plasmodesmata which were often associated with endoplasmic reticulum. Secretion accumulated beneath the cuticle which was distended but remained intact on the surface of the secretion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01273698
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  • 132
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    Structure and function in the grass ligule: The membranous ligule ofLolium temulentum L. as a secretory organ (1985)
    Springer
    Protoplasma 127 (1985), S. 128-132 
    Details
    ISSN: 1615-6102
    Keywords: Ligule ; Lolium temulentum L. ; Poaceae ; Polysaccharide cytochemistry ; Secretion ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Using phosphotungstic acid and periodic acid/thiocarbohydrazide/silver proteinate (Thiéry test) aspects of polysaccharide ultracytochemistry were studied in the membranous ligule ofLolium temulentum L. Staining results are presented for all three tissues-abaxial and adaxial epidermes and mesophyll-but discussed only for the epidermes. PTA- and PATAg-staining of the adaxial epidermis suggested synthesis of a conjugated polysaccharide material in this tissue, its accumulation in the periplasmic space and its subsequent secretion to the outside of the ligule via gaps in the cuticle. The ligule of this grass is considered to be a secretory organ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01273709
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  • 133
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    Ultrastructural ontogeny of leaf cavity trichomes inAzolla implies a functional role in metabolite exchange (1985)
    Springer
    Protoplasma 129 (1985), S. 10-27 
    Details
    ISSN: 1615-6102
    Keywords: Azolla ; Anabaena ; Symbiosis ; Nitrogen fixation ; Trichome ; Transfer cell ; Ontogeny ; Ultrastructure ; Gland ; Metabolite exchange
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Anabaena azollae is associated with two types of multicellular epidermal trichomes inAzolla leaf cavities, the simple and branched hairs. The observation of transfer cell ultrastructure in some hair cells led to speculation that the cavity hairs might participate in metabolite exchange between the symbionts. The developmental ontogeny of cavity trichomes is described here, using transmission electron microscopy, with a goal of improving our understanding of possible functions of these structures in the symbiosis. The observations have established that all cells of simple and branched hairs develop the structural characteristics of transfer cells, but not simultaneously. Rather, there is an acropetal succession of transfer cell ultrastructure beginning in terminal cells, moving to body cells where present, and ending in stalk cells. The transfer cell stage is followed immediately by senescence in all hair cells. The timing of transfer cell differentiation, considered together with information from other studies, suggests that branched hairs may be involved in exchange of fixed nitrogen between the symbionts, while simple hairs may participate in exchange of fixed carbon fromAzolla toAnabaena.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01282301
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  • 134
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    Formation of the plasma membrane during regeneration ofParamecium caudatum (1985)
    Springer
    Protoplasma 125 (1985), S. 94-102 
    Details
    ISSN: 1615-6102
    Keywords: Biogenesis ; Plasma membrane ; Regeneration ; Ultrastructure ; Paramecium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Fragments ofParamecium caudatum cells obtained by merotomy were fixed in 1% OsO4 within 5 seconds after cutting. The ultrastructure of the damaged area of the fragment was studied in oriented ultrathin sections and by scanning electron microscopy. The cytoplasm exposed by merotomy was covered during a few seconds with a new membrane. This was a typical trilaminar membrane continuous with the plasma membrane covering the undamaged surface of the cell. The surface over the wound was wrinkled into irregular grooves and ridges. The cytoplasm, mitochondria and trichocysts in the injured region were electron translucent. The cytoplasm under the new membrane contained an unusually high amount of small membrane vesicles, 20–90 nm in diameter. These were probably the remnants of subpellicular alveoli and the plasma membrane destroyed by microsectioning. The possibility that the exposed cytoplasm would be covered by mere shifting of the existing plasma membrane can be excluded. The complex structure of the cortex with its subpellicular alveoli and regularly distributed cilia provide a strong argument against this notion. It seems probable that the new membrane was built up from the available molecular material,e.g., phospholipids and proteins present in the cytoplasm. Fragments of the membrane and alveolar membranes in the form of small vesicles may have also been included into the new membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01297354
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  • 135
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    Vascular permeability to lanthanum in the rat incisor pulp (1985)
    Springer
    Cell & tissue research 239 (1985), S. 131-136 
    Details
    ISSN: 1432-0878
    Keywords: Capillary permeability ; Lanthanum ; Peripheral nerves ; Tooth pulp ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Experiments were performed to compare the permeability of capillaries supplying the endoneurial environment, which is invested by perineurium, with vascular permeability in the pulp where perineurium is absent. Anaesthetised rats were perfused through the aorta with physiological solutions containing lanthanum nitrate at 37° C. Pieces of inferior alveolar nerve and segments of mandibular incisors were immersion-fixed and transverse sections were examined electron microscopically for the distribution of lanthanum. In the pulp the nerve fibres pass between lanthanum-impermeable arterioles and venules en route to the incisal end. In the peripheral pulp a few capillaries were permeable but the most permeable capillaries lay between the odontoblasts. Pulpal capillary permeability was attributed to the fenestrated endothelium and contrasted with the unfenestrated endoneurial capillaries which were impermeable to lanthanum. Whereas the tight junctions of endoneurial capillaries are known to prevent certain blood-borne substances from entering the endoneurium, it was not clear whether the permeability of the pulpal capillaries, which are distant from the nerve fibres, could affect the nerve fibre environment. No extravasated lanthanum reached the pulpal nerve fibres suggesting that they are not affected. Technically it was not possible to examine the incisal third of the tooth where the situation could be different because the volume of the pulp decreases and capillaries lie closer to the nerve fibres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214912
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  • 136
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    Stimulatory effect of follicle-stimulating hormone on rat Leydig cells (1985)
    Springer
    Cell & tissue research 239 (1985), S. 405-415 
    Details
    ISSN: 1432-0878
    Keywords: Testis ; Leydig cell ; FSH ; Morphometry ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of FSH on the testicular interstitial tissue of immature hypophysectomized rats were studied by comparing morphological changes in Leydig cells with quantitative changes in interstitial tissue histology using morphometric analysis. Three groups of rats received subcutaneous injections of 0.5 ml saline vehicle or 10 μg rFSH or 20 ng oLH (equivalent to the amount of LH known to contaminate the FSH), twice daily for 7 days. Administration of FSH significantly increased testis weight and stimulated more advanced spermatogenesis compared to saline or LH. Morphometric analysis of testes of LH-treated rats showed a small but significant increase in total interstitial cell volume compared to saline treatment. FSH caused much greater increases in the total volume of interstitial tissue and interstitial cells than either saline or LH and significantly increased the total volume of interstitial fluid by comparison with the other groups. FSH but not saline or LH treatment resulted in a striking hypertrophy of Leydig cells, to produce cells ultrastructurally identical to Leydig cells from adults. Since the target tissue of FSH is the seminiferous epithelium, the observed effects on Leydig cells by FSH treatment suggest that the secretion of factors by the seminiferous tubules may mediate the maturation of Leydig cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218021
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  • 137
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    Demonstration of the granular layer and the fate of the hyaline layer during the development of a sea urchin (Lytechinus variegatus) (1985)
    Springer
    Cell & tissue research 239 (1985), S. 455-458 
    Details
    ISSN: 1432-0878
    Keywords: Development ; Sea urchin ; Hyaline layer ; Granular layer ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Employing electron-microscopic methods that help retain polyanionic materials, we describe the extracellular coverings of a sea urchin (Lytechinus variegatus) throughout ontogeny. The surface of the embryo is covered by a two-layered cuticle (commonly called the hyaline layer), which in turn is covered by a granular layer. The granular layer is retained after addition of alcian blue to the fixative solutions, and has not been previously described for any sea urchin. After hatching, the granular layer disappears, but the hyaline layer continues to cover most of the larval surface until settlement and metamorphosis. A few days before metamorphosis, the hyaline layer lining the vestibular invagination of the competent pluteus larva is replaced by a three-layered cuticle resembling that of the adult sea urchin. The hyaline layer covering the rest of the larva is evidently lost at metamorphosis during the involution of the general epidermis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218028
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  • 138
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    Nerve cells and synaptic connections in the intestinal nerve of the snail, Helix pomatia L. (1985)
    Springer
    Cell & tissue research 239 (1985), S. 611-620 
    Details
    ISSN: 1432-0878
    Keywords: Synapses ; Intestinal nerve ; Ultrastructure ; Helix pomatia ; Horseradish peroxidase technique
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of nerve cells and the finestructural organization of synaptic contacts have been investigated in the intestinal nerve in the snail Helix pomatia. Three types of nerve cells, occurring singly or in groups, can be distinguished on the basis of the ultrastructure of their perikaryon and content of granules. The peripheral output of these nerve cells has been verified by retrograde CoCl2 and NiCl2 staining. Both axosomatic and axo-axonic specialized synaptic contacts occur in the intestinal nerve. Presynaptic elements of these synaptic contacts contain 100–120 nm granular vesicles or 120–200 nm neurosecretory-like granules. Following intracellular horseradish peroxidase (HRP) labelling of identified central neurons responsible for peripheral regulatory processes, several labelled axons running toward the periphery can be followed throughout the branches of the intestinal nerve. These labelled axon processes (either primary axon or small collaterals) form specialized synaptic contacts, inside the intestinal nerve, and are always in a postsynaptic position. The occurrence of peripheral axo-somatic and axo-axonic synapses provides a morphological basis for integrative processes taking place in the intestinal nerve (peripheral nervous system) of Helix pomatia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219239
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  • 139
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    Electronic Resource
    Structure of tendon organs of the rat after neonatal de-efferentation (1985)
    Springer
    Cell & tissue research 241 (1985), S. 229-236 
    Details
    ISSN: 1432-0878
    Keywords: Tendon organs, rat ; Neonatal de-efferentation ; Development ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The number, size and structure of tendon organs were examined in leg muscles of the rat 3–19 weeks after de-efferentation performed in newborn animals by removal of the lumbosacral spinal cord. After this operation, tendon organs differentiated and grew in disused muscles and were innervated by primary sensory neurons, the dorsal roots of which had been disrupted. Three weeks after de-efferentation extensor digitorum longus muscles contained 14.1±1.0 (mean±standard error) and soleus muscles had 14.2±1.6 tendon organs, which corresponds to the mean number of tendon organs in the respective control muscles. The mean size of tendon organs was, however, changed. Tendon organs became on the average by 53% longer and by 35% thinner in de-efferented extensor digitorum longus muscles that were prolonged due to immobilization, as compared with shorter and wider tendon organs in de-efferented soleus muscle that remained in the shortened position. The ultrastructural differentiation of tendon organs was completed after the operation as under normal conditions. Thus it can be concluded that elimination of muscle function during the period of postnatal development indirectly affects the mean size of these receptors, but does not otherwise interfere with their morphogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214645
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  • 140
    Electronic Resource
    Electronic Resource
    The fine structure of the tarsal glands of the honeybee Apis mellifera L. (Hymenoptera) (1985)
    Springer
    Cell & tissue research 240 (1985), S. 153-158 
    Details
    ISSN: 1432-0878
    Keywords: Tarsal glands ; Ultrastructure ; Apis mellifera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Tarsal glands are located in the 6th tarsomere of adult honeybee queens, workers and drones. Their structural features are not cast or sex specific. The glandular epithelium is lined by a thin endocuticular layer. A cuticular pocket is formed from a postimaginal delamination of the cuticle secreted by the glandular epithelium. The apical plasma membrane of the glandular cells shows numerous cristae and microvilli lining large crypts that communicate with the subcuticular space. Pinocytotic vesicles, multivesicular bodies and residual dense bodies are present in the apical part of the glandular cells. The RER is well developed in perinuclear and basal parts of the glandular cells, but the Golgi apparatus is a discrete organelle without secretory granules. No exocytotic secretory structures were observed. To reach the glandular pocket, the non-proteinaceous secretory product must pass across the subcuticular space, the cuticular intima, the space between the intima and the cuticular wall, and the cuticular wall of the glandular pocket.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217569
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  • 141
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    Electronic Resource
    Differentiation of the rat epididymis after withdrawal of androgen (1985)
    Springer
    Cell & tissue research 241 (1985), S. 657-662 
    Details
    ISSN: 1432-0878
    Keywords: Epididymis ; Differentiation ; Organ culture ; Castration ; Ultrastructure ; Morphometry ; Cell types ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The differentiation capacity of the rat epididymis after depletion of androgen was studied in organ culture and in castrated rats. The differentiation of ‘narrow cells’ in 5- and 10-day-old explants and in 10-day-old castrated rats suggests that: (i) the testicular androgens are not essential for their differentiation, (ii) a differential androgen dependence exists among the epididymal cell types, (iii) the undifferentiated epithelial cells are the precursors of the narrow cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214588
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  • 142
    Electronic Resource
    Electronic Resource
    Lamellar to tubular conformational changes in the endoplasmic reticulum of the retinal pigment epithelium of the newt, Notophthalmus viridescens (1985)
    Springer
    Cell & tissue research 241 (1985), S. 629-637 
    Details
    ISSN: 1432-0878
    Keywords: Retinal pigment epithelium ; Ultrastructure ; Endoplasmic reticulum ; Lipid phase transitions ; Metamorphic mosaic model ; Myeloid bodies ; Urodeles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The retinal pigment epithelium (RPE) of the newt (Notophthalmus viridescens) was examined ultrastructurally under both in-vivo and in-vitro conditions. Five distinct conformations of smooth endoplasmic reticulum (SER), two lamellar and three tubular, were observed. The two lamellar conformations included myeloid bodies, which have previously been described (Yorke and Dickson 1984), and fenestrated SER. The latter appeared as layers of flattened or curved cisternae which were penetrated by fenestrations. Fenestrated SER became indistinguishable from the highly branched and convoluted random-tubular SER through the formation of an intermediate configuration (“tubular sheets”). The remaining tubular SER conformations appeared to arise from random-tubular SER through a progressive reduction in branching and a straightening of individual tubules. Fascicular SER was represented by the hexagonal organization of straight, unbranched tubules into bundles (fascicles). Spiral SER consisted of a similar hexagonal arrangement, but the unbranched tubules spiralled about one another. Neighbouring tubules in areas of spiral SER were also joined together by pairs of electrondense bars. Although lamellar (especially myeloid bodies) and random-tubular configurations of the SER were common features in vivo, fascicular and spiral SER were primarily conformations encountered in vitro. Conditions favouring bilayer lipid phases also appear to facilitate the formation of both myeloid bodies and fascicular SER. These conditions included increased duration of incubation, low (〈20° C) incubation temperatures, and Ca2+-free incubations with EGTA. Random-tubular SER was most prevalent in media supplemented with fetal calf serum and also after warmer (30° C) incubation temperatures. We speculate that the different conformations of SER observed in the newt RPE may be due, in part, to lipid phase transitions within the membranes of this organelle. However, the specific formation of fascicular and spiral SER may also involve some additional factor, possibly a protein.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214585
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  • 143
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    Electronic Resource
    Three-day continuous drainage of pancreatic juice in the cortisone-treated conscious rat: Analysis of enzyme activities and ultrastructural changes (1985)
    Springer
    Cell & tissue research 242 (1985), S. 191-196 
    Details
    ISSN: 1432-0878
    Keywords: Exocrine pancreas ; Rat ; Cortisone ; Ultrastructure ; Enzyme secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary We have investigated the short-term effects of hydrocortisone (60 mg/kg per day) and placebo on basal and stimulated pancreatic secretion in the conscious rat. Volume and enzyme secretion were determined; fine structural changes were examined simultaneously. The pancreatic and bile ducts were cannulated separately; pancreatic juice was drained via an isolated fistula, and bile was recirculated into the duodenum. The application of hydrocortisone led to an almost complete inhibition of the secretory response of the exocrine pancreas when stimulated with 0.25 U secretin in combination with 5 × 10-8 g caerulein per h. It strongly affected the secretion rates of volume, protein, lipase, chymotrypsin, trypsin and carboxypeptidase, whereas the secretion rate of alpha-amylase continued to show a slight increase after stimulation. After stimulation with secretin and caerulein, the hydrocortisone-treated animals showed a higher density of zymogen granules in the acinar cell and an increase in the number of autophagic vacuoles in comparison to the equally stimulated placebo-treated rats. It is concluded that the short-term inhibition of pancreatic secretion by hydrocortisone occurs largely as a result of an inhibition of cellular enzyme discharge.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225576
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  • 144
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    Electronic Resource
    Heart structure and ventricular ultrastructure of hemoglobin- and myoglobin-free icefish Channichthys rhinoceratus (1985)
    Springer
    Cell & tissue research 242 (1985), S. 669-676 
    Details
    ISSN: 1432-0878
    Keywords: Heart ; Myocardium ; Ultrastructure ; Antarctic fish ; Icefish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structural and ultrastructural characteristics of the heart of Channichthys rhinoceratus, an antarctic teleost devoid of respiratory pigments, are described and compared with those obtained from the red-blooded related species Notothenia rossii. The heart of the icefish is characterized by a spongy myocardium supplied with a highly developed arterial coronary system. This vasculature includes a subepicardial system and an extensive intratrabecular capillary network. Arterial hilar network and Thebesian vessels may also be present. The bulbus arteriosus shows unusually large spheroid structures located in the middle layer of the wall. Both white- and red-blooded species display comparable myocardial cell morphology and organelle distribution. However, the mitochondrial cristae of the former are more densely packed and the sarcolemma possesses numerous caveolae. A large proportion of non-contractile cells is also found in the icefish ventricular wall.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225436
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  • 145
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    Electronic Resource
    The pharmacokinetics and metabolism of mitoxantrone in man (1985)
    Springer
    Investigational new drugs 3 (1985), S. 109-116 
    Details
    ISSN: 1573-0646
    Keywords: pharmacokinetics ; metabolism ; mitoxantrone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary An HPLC method using paired-ion chromatography on RP C-18 material was developed. After sample clean up on XAD columns, mitoxantrone (Novantrone®; dihydroxyanthracenedione) in concentrations below 1 ng/ml in serum and 0.2 ng/ml in urine were measurable with a coefficient of variation 〈9.3% at a wavelength of 658 nm. Four metabolites were separated in urine. The major metabolite cochromatographed with the synthesized dicarboxylic acid of mitoxantrone. Within 48 hours 4.4% of the administered dose was excreted in urine as mitoxantrone, 0.5% as metabolite 1 and 0.3% as metabolite 2. The pharmacokinetic parameters are adequately described by a three-compartment model with a terminal half-life of 214.8 hours, and a volume of distribution (ss) of 3792 litres. The total body clearance was 358 ml/min and the renal clearance was 26.2 ml/min.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00174157
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  • 146
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    Electronic Resource
    Plasma kinetics and effects of 5,6-dihydro-5-azacytidine in mice and L1210 tumor (1985)
    Springer
    Investigational new drugs 3 (1985), S. 35-41 
    Details
    ISSN: 1573-0646
    Keywords: 5,6-dihydro-5-azacytidine ; leukemia (L1210) ; infusions (in vivo) ; clonogenic assays (in vitro) ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The plasma kinetics of 5,6-dihydro-5-azacytidine (DHAC) was determined in mice using an HPLC method following an intravenous dose of 2000 mg/kg (LD10). Pharmacokinetic parameters calculated from these single dose data were sufficient to predict steady state plasma concentrations produced by s.c. infusion of DHAC. Lethal toxicity (LD66) occurred at an infusion rate of 37 mg/kg/h (111mg/m2/h), corresponding to a plasma steady-state DHAC concentration 38 ± 14 μg/ml when the infusion time was 96 h; no lethality occurred at infusion times of 72 h or less. In vitro clonogenic assays and in vivo therapeutic experiments with L1210 tumor indicated that increasing the exposure time at concentrations near 25 μg/ml from 24 to 72 h increased the cell kill only slightly. The maximum log cell kill of L1210 estimated from either in vitro or in vivo data was 1.5 logs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00176822
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  • 147
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    Electronic Resource
    Human pharmacokinetics of esorubicin (4′ -deoxydoxorubicin) (1985)
    Springer
    Investigational new drugs 3 (1985), S. 361-368 
    Details
    ISSN: 1573-0646
    Keywords: 4′-deoxydoxorubicin ; esorubicin ; anthracycline ; anticancer agent ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of esorubicin, a new anthracycline antibiotic, was investigated in conjunction with a phase I clinical trial. The drug was administered to 12 patients as an intravenous bolus at a dose of 20 to 40mg/m2. All patients had normal renal and hepatic functions and no third space fluid accumulation. Plasma and urine samples were assayed by HPLC. The peak plasma concentration of esorubicin was 0.74 ± 0.57 μM (mean ± SE). Esorubicin disappeared from plasma according to a tri-exponential pattern with a terminal half-life of 20.4 ± 7.3 hr. The area under the plasma concentration versus time curve was 0.64 ± 0.31 μMxhr. Total body plasma clearance was 45.5 ± 26.8 liter/min/m2 and the apparent volume of the central compartment, 41.0 ± 24.8 L. A single metabolite, 4′-deoxydoxorubicinol, was detected in plasma. This metabolite was observed in 5 patients only and its mean peak concentration was 0.029 ± 0.017 μM. The area under the plasma versus concentration time curve for 4′-deoxydoxorubicinol was 0.02 ± 0.014 μMxhr. The urinary excretion of total fluorescence within 5 days of therapy was 7.3 ± 1.3% of the administered dose. Esorubicin represented more than 80% of the excreted anthracyclines. As in plasma, 4′ -deoxydoxorubicinol was the only metabolite detectable in urine. No correlation between the various pharmacokinetic parameters and drug-induced toxicity was observed in this small group of patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00170759
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  • 148
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    Electronic Resource
    Human pharmacokinetics of 1-[2-[2-(4 pyridyl)-2-imidazolinyl-(1)]-ethyl]-3-(4-carboxyphenyl) urea (CGP 15720A) (1985)
    Springer
    Investigational new drugs 3 (1985), S. 375-381 
    Details
    ISSN: 1573-0646
    Keywords: CGP 15720A ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Pharmacokinetics of CGP 15720A have been studied in patients receiving this drug in a short I.V. infusion during its phase I clinical trial. Plasma decay was biphasic with a mean t1/2β of 4.9 ± 2.47h. The drug was cleared rapidly from plasma (7.02 ± 5.95 L/h). Renal clearance (4.13 ± 1.65 L/h) appears to be the major clearance pathway. The steady state volumes of distribution of the drug indicate limited tissue distribution for the drug. Studies with plasma and urine of patients receiving 14[C] GCP 15720A indicate that the drug is not metabolized. CGP 15720A could be measured in cerebrospinal fluid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00170761
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  • 149
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    Electronic Resource
    Pharmacology of mitoxantrone: mode of action and pharmacokinetics (1985)
    Springer
    Investigational new drugs 3 (1985), S. 101-107 
    Details
    ISSN: 1573-0646
    Keywords: mitoxantrone ; pharmacokinetics ; mode of action ; elimination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Although a number of investigators have established that mitoxantrone (Novantrone®; dihydroxyanthracenedione) inhibits RNA and DNA synthesis and intercalates with DNA in vitro, its exact mechanism of action is unclear. Mitoxantrone is structurally related to a series of substituted anthraquinones and has features known to be essential for DNA intercalation; however, we have determined recently that mitoxantrone binds DNA in intact L1210 leukemia cells by a non-intercalative, electrostatic interaction and induces both protein associated and non-protein associated DNA strand scissions. The difference between mitoxantrone and doxorubicin with respect to their interactions with DNA could account for their relative lack of cross-resistance in the treatment of lymphoma and acute leukemia. Distribution and half-life data provide a pharmacological rationale for the use of mitoxantrone on an intermittent dosing schedule. Considerable evidence exists to suggest that mitoxantrone undergoes extensive metabolism, probably in the liver. Preliminary data show that abnormal liver function leads to decreased rates of total body mitoxantrone clearance, suggesting a possible need for dose reduction in patients with severe liver dysfunction. The most important route of mitoxantrone elimination appears to be fecal. Because of the relatively low urinary excretion it is unlikely that the standard drug dose must be reduced in the presence of compromised renal function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00174156
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  • 150
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    Electronic Resource
    Ultrastructure of corpora allata of known activity during the vitellogenic cycle in the cockroach Diploptera punctata (1985)
    Springer
    Cell & tissue research 239 (1985), S. 317-327 
    Details
    ISSN: 1432-0878
    Keywords: Corpora allata ; Ultrastructure ; Juvenile hormone ; Rates of synthesis ; Reproductive cycle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructure was correlated with rates of juvenile hormone synthesis in corpora allata from females of the viviparous cockroach Diploptera punctata at seven daily intervals during the first vitellogenic cycle. Synthetic activity of the glands was determined by in vitro radiochemical assay before the glands were fixed for electron microscopic analysis. The cycle in rates of juvenile hormone synthesis progressed from about 20 pmol h-1 per gland pair (oocytes 0.60 mm long) to a maximum mean rate of 140 pmol h-1 per pair (oocytes 1.40–1.47 mm long) and declined to about 20 pmol h-1 per pair at ovulation (oocytes about 1.65 mm long). Conspicuous ultrastructural changes occurred with changing synthetic rates. In glands with increasing rates of synthesis, mitochondria showed less electron-dense matrix, greater diameter and more irregular shape. Smooth endoplasmic reticulum changed from easily seen to obscure tubules, networks, and vesicles. Rough endoplasmic reticulum appeared in longer, more curved segments. Newly formed autophagic vacuoles appeared in all glands of highest activity rates. In glands with decreasing rates of synthesis, the mitochondrial matrix became denser, width smaller, and shapes less irregular. Smooth endoplasmic reticulum again appeared tubular and distinct. Golgi complexes were more conspicuous. Rough endoplasmic reticulum in whorls and large numbers of autophagic vacuoles continued to be present.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218010
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  • 151
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    Electronic Resource
    Electron-microscopic studies on the physiological cell loss in the gastric mucosa of the golden hamster (1985)
    Springer
    Cell & tissue research 239 (1985), S. 343-347 
    Details
    ISSN: 1432-0878
    Keywords: Gastric mucosa ; Surface mucous cell ; Physiological cell loss ; Cell renewal ; Ultrastructure ; Golden hamster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Fine-structural aspects of physiological cell loss in the gastric mucosa of the golden hamster were observed. As the surface mucous cell ascends along the gastric pit, the cell becomes taller and funnel-like in shape. The interfoveolar cell located at the superficial portion of the gastric pit has many lysosomes and a few lipid droplets in the cytoplasm. The nucleus moves toward the upper region of the cytoplasm, while the Golgi apparatus moves downward toward the infranuclear region. After the rupture of the apical plasma membrane takes place, the lateral and basal plasma membranes of this cell remain in spite of loss of the cell contents. Between the basal plasma membrane of the interfoveolar cell and the capillary endothelium is a thick connective tissue layer characterized by densely packed collagen fibrils. The remaining basal and lateral plasma membranes of the ruptured cell and the thick underlying collagenous layer might play a role in protecting the tissue from potential damage induced by the physiological cell loss.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218013
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  • 152
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    Electronic Resource
    The ultrastructural and biosynthetic characteristics of steroidogenic cells in the gonad of Monopterus albus (Teleostei) during natural sex reversal (1985)
    Springer
    Cell & tissue research 239 (1985), S. 383-394 
    Details
    ISSN: 1432-0878
    Keywords: Steroid cell ; Ultrastructure ; Steroidogenesis ; Intersexual fish ; Monopterus albus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructural and biosynthetic characteristics of the steroid cells in the gonad of Monopterus albus have been studied. Ultrastructural features related to steroidogenesis have been identified in the interstitial Leydig cells, Sertoli cells, granulosa cells and thecal cells, and are especially abundant in the Leydig cells during the mid-intersexual phase. Steroidogenic ultrastructures in the Sertoli cells develop only during the maturation of the spermatogenic cysts, whereas in the granulosa and thecal cells, these features become obvious only during the maturation of the large oocytes. EM evidence also suggests a nutritive function for the Sertoli cells and the granulosa cells. Results of in vitro steroidogenic studies, using either testosterone or progesterone as a precursor, show a predominant conversion to androstenedione and 5α-reduced compounds, and suggest a change in biosynthesis from 5α-reduced products to androstenedione during sex reversal. 11-Ketotestosterone (11KT) has been identified, but not 11 β-hydroxytestosterone. Production of 11 KT is high in the late intersexual and the male phases, but a lack of a marked variation in 11KT production between the early and the mid-intersexual phase suggests that this steroid is not a trigger for natural sex reversal in Monopterus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218019
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  • 153
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    Acetylcholinesterase activity in nerve endings of tails of Rana japonica and R. catesbeiana during metamorphosis (1985)
    Springer
    Cell & tissue research 239 (1985), S. 511-517 
    Details
    ISSN: 1432-0878
    Keywords: Nerve ending ; Tadpole tail ; Ultrastructure ; Acetylcholinesterase ; Metamorphosis ; Rana japonica ; R. catesbeiana
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In anuran tadpole tails, the myelinated motor nerve fibers branch in the myoseptum to innervate both red and white muscle fibers at, or near, their ends. There are no significant ultrastructural differences between the nerve endings of the two types of muscle fibers. Intense acetylcholinesterase reaction product was observed in synaptic clefts and junctional folds, as well as in transverse tubules. As metamorphosis proceeded, the junctional folds of the nerve endings disappeared, however, acetylcholinesterase reaction product was still observed in the synaptic clefts. As muscle fibers began to degenerate, nerve endings began to separate from them. However, after nerve endings were completely separated from the surfaces, degenerated muscle fibers, synaptic and cored vesicles were still well preserved although no acetylcholinesterase reaction product was found. It seems clear that the mechanism of the muscle degeneration in the tadpole tail during metamorphosis is not the result of the degeneration of its nerve endings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219229
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  • 154
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    Electronic Resource
    Evidence for tight junctions between odontoblasts in the rat incisor (1985)
    Springer
    Cell & tissue research 239 (1985), S. 137-140 
    Details
    ISSN: 1432-0878
    Keywords: Lanthanum ; Odontoblasts ; Tight junctions ; Tooth pulp ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Odontoblasts are known to be involved in the process of dentinogenesis but it is not clear whether substances may also be deposited in predentine and dentine by passing between these cells. Although tight junctions have been described, it is not clear if they are macular or “leaky” as opposed to continuous or “tight”. In this study use has been made of the permeability of fenestrated capillaries amongst the odontoblasts to deposit the penetrative tracer lanthanum in the interodontoblastic space. This was done by perfusion of anaesthetized rats with physiological solutions containing lanthanum nitrate at 37° C. Immersion fixation of transverse segments of mandibular incisors and examination with an electron microscope showed that lanthanum could permeate 40–50 μm between the odontoblasts to reach the peripheral pulp. Towards the predentine, often less than 10 μm from the capillaries, its progress was abruptly and completely halted by the junctions at the apical ends of the odontoblast cell bodies. Lanthanum was not found in the predentine. The mature secretory odontoblasts in the rat incisor have therefore been shown to be joined by continuous tight junctions. In the process of dentinogenesis this means that all substances deposited in predentine and dentine must arrive by passing through the odontoblasts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214913
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  • 155
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    Ultrastructural changes in the spleen of the natterjack, Bufo calamita, after antigenic stimulation (1985)
    Springer
    Cell & tissue research 239 (1985), S. 435-441 
    Details
    ISSN: 1432-0878
    Keywords: Spleen ; Dendritic cells ; Ultrastructure ; Immunization ; Bufo calamita
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the present study comparative aspects of the ultrastructure of the spleen were analyzed in non-immunized and T-dependent antigen-challenged natterjacks, Bufo calamita. Special attention is focused on the role of the non-lymphoid components in the splenic immunoreactivity. Ten days after primary immunization with sheep erythrocytes, splenic lymphoid follicles increase considerably in number and size. By that time, lymphoblasts, medium and large lymphocytes abound in the periphery of the white pulp near the marginal zone. Meanwhile, in the red pulp numerous monocytes migrating across the sinusoidal walls apparently transform into giant, dendritic-like cells. Twenty days after immunization the splenic lymphoid follicles decrease in number, although certain reactivity persists and numerous plasma cells occur in the cell cords and sinusoids of the red pulp. These results are discussed comparatively with those reported in other lower vertebrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218024
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  • 156
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    Heterogeneity among macrophages cultured from mouse bone marrow (1985)
    Springer
    Cell & tissue research 239 (1985), S. 693-701 
    Details
    ISSN: 1432-0878
    Keywords: Macrophage ; Bone marrow culture ; Heterogeneity ; Ultrastructure ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of macrophages in culture from mouse bone marrow was followed for 14 days by light and electron microscopy, ultrastructural cytochemistry, and flow cytometric analysis. By 10 days greater than 97% of the cells in culture were mononuclear phagocytes, and by 12 days greater than 99% were identifiable as macrophages. Ultrastructurally, three subpopulations of mononuclear phagocytes were distinguished based on the appearance of cytoplasmic structures. Early in culture, cells containing large, membrane-bounded vesicles predominated. With increasing time in culture these cells were replaced to varying degrees first by cells that contained vesicles filled with relatively dense, osmiophilic material and, finally, by macrophages that contained granules of various sizes, shapes and staining densities. Cytochemical (peroxidase and acid phosphatase) and colloidal gold uptake studies at the ultrastructural level suggested that many, if not all, of these cytoplasmic structures arose by pinocytosis and subsequent fusion of pinocytic vesicles with lysosomes. Analysis of DNA content of propidium iodide-stained nuclei by flow cytometry, coupled with the examination of cells treated with colchicine to arrest mitosis in metaphase, suggested that cell cycling was a negligible contributor to heterogeneity within cultured populations. Thus, by waiting until 12–14 days after bone marrow cultures were initiated, with partial replenishment of the culture medium at 7 days, heterogeneity could be greatly reduced in cultured macrophage populations. Taking this fact into consideration could help to reduce the variability seen in functional studies of macrophage populations that are less homogeneous.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219251
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  • 157
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    Pharmacokinetics of theobromine and its metabolites in rabbits (1985)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 13 (1985), S. 41-53 
    Details
    ISSN: 1573-8744
    Keywords: theobromine ; pharmacokinetics ; metabolism ; urinary data ; rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pharmacokinetics of theobromine (3, 7-DMX) and its metabolites was investigated in detail in four male rabbits after bolus intravenous injection (4 mg/kg) of the compound. Apparent first-order rate constants for the metabolic processes involved in the formation of 3,7-DMX metabolites and their excretion in urine were calculated. Theobromine, 7-methylxanthine (7-MX) and 3-methylxanthine (3-MX) were measured in blood and urine, and the other metabolites were determined only in urine. An appropriate model of 14 compartments is formulated to describe the disposition of 3,7-DMX and its metabolites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01073655
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  • 158
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    Pharmacokinetic approaches to drug distribution in the cerebrospinal fluid based on ventricular administration in beagle dogs (1985)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 13 (1985), S. 387-403 
    Details
    ISSN: 1573-8744
    Keywords: cerebrospinal fluid ; pharmacokinetics ; ACNU ; DFMO ; MGBG ; beagle dogs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Two mathematical approaches are described to approximate the distribution of compounds (e.g., drugs) in the cerebrospinal fluid (CSF) downstream of or distal to both the ventricular injection site and the cisterna magna sampling site. The first approach uses a graphic representation and is, in essence, model independent;the second approach considers the geometry and physiology of CSF distribution and clearance. In all studies, radiolabeled inulin was used as an “internal standard” since it is not metabolized and is eliminated from the CSF primarily by bulk flow. Temporal comparison of the study compound to radiolabeled inulin in the cisternal CSF allowed testing of these models in beagle dogs. One use of this data is in the estimation of the drug exposure integral for antineoplastic drugs administered in the CSF to treat leptomeningeal neoplasia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01061476
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  • 159
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    The pharmacokinetics of chlortetracycline orally administered to turkeys: Influence of citric acid andPasteurella multocida infection (1985)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 13 (1985), S. 243-264 
    Details
    ISSN: 1573-8744
    Keywords: chlortetracycline (aureomycin) ; citric acid ; pharmacokinetics ; physiological ; turkeys ; fowl cholera ; disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A physiologically based pharmacokinetic model was developed to describe the absorption and disposition of chlortetracyline (CTC) in the healthy and diseased (fowl cholera) turkey. The CTC was given (with and without citric acid) as an oral (15 mg/kg) or i.v. (1 mg/kg) dose. When minerals (0.3 g/LCa2+, 0.1 g/LMg2+) were dissolved in the bird's drinking water, the model indicated that the addition of citric acid (mass ratio of 10 citrate:1 CTC) increased the fraction of dose absorbed from 0.06 to 0.16; once absorbed, the fractions of drug eliminated by renal excretion, biliary secretion, and chemical decomposition were 50, 46, and 4%, respectively. The presence of fowl cholera appeared to increase plasma levels by increasing the intestinal permeability and lowering the hepatic and/or renal clearance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01065655
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  • 160
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    The determination of mean residence time using statistical moments:It is correct (1985)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 13 (1985), S. 549-554 
    Details
    ISSN: 1573-8744
    Keywords: mean residence time ; statistical moments ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The present communication seeks to end a controversy created by a recent publication regarding the applicability of statistical moment principles for determination of mean residence time of drug in the body ¯tb.It is shown that the equation ¯tb=AUMC/AUC iscorrect when applied to pharmacokinetic systems in which the total drug elimination rate is directly proportional to the drug concentration in the systemic circulation, i.e., firstorder central elimination. More general equations for ¯tb in terms of elimination rate, amount eliminated, and amount in the body are presented along with demonstrations of their utility.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01059336
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  • 161
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    The pharmacokinetics of α-methyldopa in dogs (1985)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 13 (1985), S. 405-423 
    Details
    ISSN: 1573-8744
    Keywords: pharmacokinetics ; methyldopa ; first-pass effect ; enterohepatic recirculation ; apparent bioavailability ; dogs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract α-Methyldopa was intraarterially and orally administered to dogs at two dose levels in a randomized complete crossover design. The appearance of secondary peaks in the plasma concentration-time profiles indicated the presence of enterohepatically recycled methyldopa. This was established by the absence of a secondary peak following readministration of a dose after biliary cannulation and the detection of methyldopa in the bile of a cannulated dog. Enterohepatic recirculation was estimated to account for a mean of 16.2% of the area under the plasma concentration—time profile after intraarterial administration. Total systemic clearance, defined as the sum of elimination by all routes from the general circulation of the administered dose, and corrected for enterohepatic recirculation, averaged (±SD) 99.4 ±24.6 ml/min in the dog. An extended average apparent terminal half-life of 6.0±5.2hr was exhibited after oral administration compared to an average half-life of 3.1 ±1.8 hr following intraarterial administration. Elimination kinetics were linear in the dose range studied. Oral plasma concentration data suggest that the apparent bioavailable fraction may be dose dependent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01061477
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  • 162
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    The human pharmacokinetics of cefotaxime and its metabolites and the role of renal tubular secretion on their elimination (1985)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 13 (1985), S. 121-142 
    Details
    ISSN: 1573-8744
    Keywords: cefotaxime ; pharmacokinetics ; metabolites ; probenecid interaction ; renal tubular secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pharmacokinetics of cefotaxime were investigated in human volunteers given constant intravenous infusions, intravenous bolus, and intramuscular doses of the drug. After intravenous dosing, the plasma levels of cefotaxime declined in a biphasic manner with a terminal half-life varying between 0.92 and 1.65 hr. Moreover, the pharmacokinetics were linear up to at least a 2.0 g dose for volume of distribution based on area (23.3–31.31), plasma clearance (249–288 ml/min), and renal clearance (151–177 ml/min). Renal tubular secretion of intact cefotaxime and each of its metabolites was demonstrated by its interaction with probenecid, although the ratio of drug to metabolites ultimately excreted in urine after probenecid was similar to that seen normally (54±6, 19±4, 6.5±0.7 and 5.5±0.7% for cefotaxime, DACM, M2, and M3, respectively, when calculated as a percentage of the dose). The observed half-lives of DACM, M2, and M3 were 2.3±0.4, 2.2 ±0.1 and 2.2 hr, respectively. However, when the true half-life of DACM was calculated (0.83±0.23 hr) it was not only significantly shorter than that observed but also shorter than that for intact cefotaxime. The plasma clearance of DACM (744 ±226 ml/min) was much higher than that of cefotaxime while the volume of distribution was of a similar order (56 ±241). When administered intramuscularly, there was good absorption of cefotaxime from the site of injection (92–94%) giving maximum plasma levels of the drug of between 30 and 35 mg/l at approximately 40 min after dosing. Thereafter, the plasma levels of cefotaxime declined in a monophasic manner with a half-life (1.0–1.2 hr) similar to that of the terminal half-life seen after intravenous administration. Lidocaine had no significant effect on either its absorption or elimination kinetics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01059394
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  • 163
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    Negative power functions of time in pharmacokinetics and their implications (1985)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 13 (1985), S. 309-346 
    Details
    ISSN: 1573-8744
    Keywords: clearance curves ; pharmacokinetics ; tracer kinetics ; homogeneous compartments ; multiexponentials ; negative powers of time ; gamma functions ; random walks with drift ; distributions of time intervals ; Inverse Gaussian distributions ; convolutions ; models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract When a clearance curve in pharmacokinetic studies- and in tracer kinetics in general — is well fitted by a sum of negative exponentials of time, in very many cases the data would also be well fitted over much or all of the same period by a function of time consisting mainly of a negative power or by a gamma function. There are also instances where two such power functions can be observed in the same clearance curve. Examples are given from numerous reanalyses of published results. These facts have not been explained, except as being fortuitous, by any existing theory or model based on two or more homogeneous compartments. Theoretical and practical implications are outlined and some general recipes are put forward with a view to replacing multicompartmental analysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01065658
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  • 164
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    Estimation of area under the curve for drugs subject to enterohepatic cycling (1985)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 13 (1985), S. 589-608 
    Details
    ISSN: 1573-8744
    Keywords: enterohepatic recirculation ; pharmacokinetics ; hepatic extraction ; area under the curve ; model ; bile ; simulated concentration-time curves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A physiologically realistic model is used to provide insight into the design of sampling protocols for accurate determination of AUC(0– ∞) for drugs subject to enterohepatic cycling. Through simulation of plasma concentration- time curves for such drugs it is found that (1) more than one peak is predicted after oral and intravenous administration of a single dose of drug, (2) the relative magnitude of peaks is dependent on the hepatic extraction ratio for both oral and intravenous drug administration, (3) the percent of the AUC(0– ∞) in later time intervals is also a function of the hepatic extraction ratio, and (4) present methods for the design of sampling protocols may not provide accurate estimates of AUC(0– ∞) (especially for highly extracted drugs), because (a) peaks are only evident at later times after intravenous administration when plasma sampling is less frequent, (b) much of the area occurs at later times, and (c) the amount of drug in the sampling compartment after oral administration is much lower than that after intravenous administration of drug and could be incorrectly interpreted as low bioavailability if sampling is not carried out for a long period of time. The types of oral and intravenous profiles predicted for highly extracted drugs are exemplified by data for naltrexone in the monkey.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01058903
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  • 165
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    Pharmacokinetics of diminazene in sheep (1985)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 13 (1985), S. 173-184 
    Details
    ISSN: 1573-8744
    Keywords: diminazene ; pharmacokinetics ; protein binding ; plasma/rbc partition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pharmacokinetic behavior of diminazene in plasma after administration of 2 mg/kg i.v. and 3.5 mg/kg i.m. was studied in four healthy Dala × Ryggja rams. Following i.v. injection, the data were satisfactorily described by a triexponential equation; the apparent volume of distribution at the steady-state was 0.56±0.04 L/Kg (X±sd; n=4); total body clearance averaged 1.1±0.09 ml/kg/min and elimination half-life was 9.30±1.40 hr. After intramuscular administration peak plasma levels of 6.30–7.57 μg/ml were reached in 20 to 45 min and the mean absorption time averaged 5.83±1.61 hr. Systemic availability relative to the intravenous dose was 95.10±23.21% and mean residence time averaged 14.16±1.55hr. The partition of diminazene between erythrocytes and plasma averaged 0.64±0.10; plasma protein binding was high (65–85%) and concentration-dependent. Based on the experimental data obtained, an initial i.m. dose of 2.5 mg/kg followed by 2 mg/kg 24 hr later should be safe and effective in cases of babesiosis and trypanosomiasis sensitive to diminazene. A preslaughter withdrawal period of 14–26 days was estimated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01059397
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  • 166
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    Fractions metabolized in a triangular metabolic system: Cinromide and two metabolites in the rhesus monkey (1985)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 13 (1985), S. 373-386 
    Details
    ISSN: 1573-8744
    Keywords: Metabolite ; pharmacokinetics ; fraction metabolized ; cinromide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A previous study of the metabolic fate of cinromide (3-bromo-N-ethylcinnamamide) in rhesus monkey established that half of a dose is metabolized byN-deethylation to an active metabolite, 3-bromocinnamamide. Both cinromide and its proximal metabolite can be metabolized by amide hydrolysis to a second metabolite, 3-bromocinnamic acid, resulting in a triangular metabolic problem. This investigation was undertaken to distinguish between these two nonexclusive possibilites. A preliminary study was carried out to characterize the pharmacokinetics of 3-bromocinnamic acid. In the main study, six monkeys received an intravenous dose of cinromide, 3-bromocinnamamide, and 3-bromocinnamic acid in a randomized order. The time courses of compound administered and corresponding metabolites were followed. The following fractions of dose metabolized (mean±SD) were obtained: cinromide to 3-bromocinnamide: 0.53 ±0.24; 3-bromocinnamamide to 3-bromocinnamic acid: 0.53 ±0.21; cinromide to 3-bromocinnamic acid directly: 0.48 ±0.32. Thus, it was found that 3-bromocinnamic acid is formed directly from cinromide and from 3-bromocinnamamide. Also, as primary metabolites, 3-bromocinnamic acid and 3-bromocinamamide account for all of a cinromide dose with a mean value of 1.00±0.34. The observed variability in these fractions metabolized was explained by the fact that in the solution of the triangular metabolic problem, three clearances are assumed to remain constant over three studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01061475
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  • 167
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    Analysis of methadone disposition in the pregnant rat by means of a physiological flow model (1985)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 13 (1985), S. 355-372 
    Details
    ISSN: 1573-8744
    Keywords: methadone ; rat ; pregnancy ; physiological flow model ; pharmacokinetics ; scaleup ; opiates ; GC-MS analytical method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A physiological flow model simulating the pregnant rat is constructed for methadone. The model includes brain, fetal, hepatic, intestinal, muscular, pulmonar, and renal tissues. Since methadone kinetics may provide valuable information for optimal therapy, an attempt is made to describe methadone kinetics in brain and other tissues simultaneously. The concentration-time profiles of methadone in various tissues after an i.v. bolus dose of 2 rng/kg are reasonably described by the model. The role of the different organs in the disposition of methadone is further explored by simulations. It is found that methadone is initially sequestered in lung tissues immediately after intravenous administration. Therefore, both venous and arterial blood pools are included in the model. Rapid uptake then takes place into vascular-rich organs, including kidneys, liver, and muscle, followed by redistribution into less penetrable organs, such as brain, fetal, and intestinal tissues. Data indicate that diffusional resistance governs the transfer of drug into brain, fetal, and intestinal tissues. Simulations suggest that muscular tissues play an important role in the rat and in man, becoming the major methadone reservoir. The tissue-to-blood partition coefficients derived from equilibrium conditions in this study are generally higher than those reported hitherto. The model is scaled up to a human to investigate whether it can be used to predict the concentration of methadone in different organs after a certain dose. Volume of distribution (Vdss) and biological half-life are consistent with earlier findings in man. The study is done by means of the GC-MS method with selected ion-monitoring where deuterated methadone is used as an internal standard.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01061474
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  • 168
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    Mitosis in the basidiomycete fungusTulasnella araneosa (1985)
    Springer
    Protoplasma 126 (1985), S. 1-18 
    Details
    ISSN: 1615-6102
    Keywords: Mitosis ; Ultrastructure ; Phylogeny ; Basidiomycotina ; Tulasnella araneosa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This is a report of a light and electron microscopic study of mitosis in the basidiomycetous fungusTulasnella araneosa. The study employs serial section analyses of nuclei preselected with fluorescence microscopy. It is the first such study of nuclear division in theTulasnellaceae and the first of conjugately dividing nuclei in basidiomycetous hyphal segments lacking clamp connections. Mitosis inT. araneosa is unusual in that the spindle pole body (SPB) develops asymmetrically; the SPB middle piece is large and transversely curved; and the nuclear envelopes of adjacent late anaphase nuclei fuse. Analyses of mitotic characteristics used for phylogenetic purposes indicate that, of the many characters available, only SPB characteristics are presently valuable. Available evidence indicates that the SPB ofT. araneosa is more different from that ofUredinales than it is from representatives of the other four orders ofBasidiomycotina that have been thoroughly studied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01287668
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  • 169
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    An efficient procedure for isolation of nuclei from plant protoplasts (1985)
    Springer
    Protoplasma 128 (1985), S. 184-189 
    Details
    ISSN: 1615-6102
    Keywords: Nuclear isolation ; pH ; Protoplasts ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The present communication describes an easy, efficient and rapid method for isolation of nuclei from plant protoplasts. Release of nuclei is accomplished by disruption of protoplasts in an appropriate buffer containing a very low concentration (0.01%) of the detergent Triton X-100. The pH of the nuclei isolation buffer (5.3) played a critical role in the recovery of stable nuclei in large numbers. Supplementation of buffer (10 mM MES) with spermine (0.1 mM), dithiothreitol (2.5 mM), ethylenediaminetetraacetic acid (2.5 mM) and Nad and KCl (10 mM each) improved nuclear yield and quality. With the method developed it is possible to routinely recover 95% nuclei from the protoplasts within 30 minutes. The nuclear preparations are of high purity with little detectable cytoplasmic contamination and no clumping of the nuclei. The structural integrity of the nuclei has been assessed and confirmed by Nomarski differential interference contrast optics and ultrastructural observations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01276340
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  • 170
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    An ultrastructural approach to the adaptive role of the cell wall in the intertidal algaFucus virsoides (1985)
    Springer
    Protoplasma 128 (1985), S. 208-217 
    Details
    ISSN: 1615-6102
    Keywords: Cation exchange ; Cell wall ; Fucus virsoides ; Intertidal seaweeds ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructure of the cell wall and the distribution of alginate, cellulose and fucoidans were studied in the intertidal algaFucus virsoides. Microanalysis and precipitation with KPA revealed a cation localization in the wall, mainly corresponding with sulphated polysaccharide distribution. Thus, the adaptive resistance to changes in ionic environment seems to take place through a cation binding to the cell wall polysaccharides, principally at the thallus surface, employing an avoidance mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01276343
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  • 171
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    The ultrastructure of the plasmodesmata of the salt glands ofTamarix as revealed by transmission and freeze-fracture electron microscopy (1985)
    Springer
    Protoplasma 125 (1985), S. 13-23 
    Details
    ISSN: 1615-6102
    Keywords: Plasmodesmata ; Ultrastructure ; Freeze-fracture ; Salt glands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Numerous plasmodesmata occur in the walls between the secretory cells ofTamarix salt glands. The plasmalemma bounds the plasmodesmata and is continuous from cell to cell. In freeze-fracture, the e-face of the plasmalemma within the plasmodesmata is virtually devoid of intramembranous particles while, in contrast, the p-face is decidedly enriched with particles. The axial components appear to be a tightly curved membrane bilayer, as judged from measurements and their appearance in freeze-fracture, and the e-face of this membrane is also devoid of particles. Observations from both thin sections and freeze-fracture replicas indicate the presence of a circular cluster of six particles around the axial component near the cytoplasmic termini of the plasmodesmata. These particles extend from the p-face of the axial component to the p-face of the plasmalemma. These observations are summarized in a model.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01297346
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  • 172
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    The ultrastructure of mitosis inIsochrysis galbana parke (Prymnesiophyceae) (1985)
    Springer
    Protoplasma 125 (1985), S. 140-151 
    Details
    ISSN: 1615-6102
    Keywords: Mitosis ; Cytokinesis ; Alga ; Isochrysis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mitosis and cytokinesis have been studied in the flagellate algaIsochrysis galbana Parke (Prymnesiophyceae). Nuclear division is preceded by replication of the flagella and haptonema, the Golgi body and the chloroplast; fission in the chloroplast occurs in the region of the pyrenoid. During prophase, spindle microtubules radiating from two ill-defined poles are formed. The nuclear envelope breaks down and the chromatin condenses. At metaphase the spindle is fully developed, some pole-to-pole microtubules passing through the well-defined chromatin plate, others terminating at it. No kinetochores or individual chromosomes were observed. By late metaphase, many Golgi-derived vesicles may be seen against the two poleward faces of the metaphase plate. During anaphase, the two daughter masses of chromatin move towards the poles. In early telophase, the nuclear envelope of each daughter nucleus is complete only on the side towards the adjacent chloroplast, remaining open on the interzonal side. However, during telophase each nucleus becomes reorientated so that it lies lateral to the long axis of the spindle and with its open side towards the chloroplasts. By late telophase, each new nuclear envelope is complete and confluence with the adjacent chloroplast ER established. Cytokinesis and subsequent segregation of the daughter cells are effected by the dilation of Golgi- and ER-derived vesicles in the interzonal region. No microtubular structures are involved. Comparisons with the results from other studies of mitosis in members of thePrymnesiophyceae show that they all have a number of features in common, but that there are differences in detail between species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01297359
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  • 173
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    The influence of lignification on the development of vascular tissue inVigna radiata L. (1985)
    Springer
    Protoplasma 124 (1985), S. 87-95 
    Details
    ISSN: 1615-6102
    Keywords: L-α-aminooxy-β-phenylpropionic acid ; Lignification ; Secondary cell wall ; Ultrastructure ; Vigna radiata ; Xylem
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary During the early development of mungbean seedlings, treatment with L-α-aminooxy-β-phenylpropionic acid (AOPP), a potent specific inhibitor of phenylalanine ammonia-lyase, results in an inhibition of anthocyanin and lignin synthesis. The xylem vessels of the hypocotyl and root of AOPP treated seedlings collapse, and the cellulose microfibrils of the unlignified secondary wall are separated from one another and lie disorganized in the lumen of the mature xylem cell. The differentiation of the secondary cell wall appears unaffected by AOPP treatment, as does the ultrastructure of the wall of the mature phloem fibers of the root which is also lignified in untreated tissue. The results are discussed in the light of current thinking on the role and development of lignification in the xylem vessel.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01279727
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  • 174
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    Preprophasic establishment of division polarity in monoplastidic mitosis of hornworts (1985)
    Springer
    Protoplasma 124 (1985), S. 175-183 
    Details
    ISSN: 1615-6102
    Keywords: Division polarity ; Hornworts ; Microtubules ; Mitosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Preprophase in the monoplastidic mitotic cells ofPhaeoceros andNotothylas is characterized by the establishment of a division site in the absence of a typical preprophase band. The future cytokinetic plane is predicted by plastid orientation and development of an elaborate preprophasic microtubule system perpendicular to the division plane. Division of the single plastid is initiated early in preprophase and the constricting plastid migrates to a position perpendicular to the future plane of division. Plastid orientation assures that division of the plastid by mid-constriction will result in distribution of a plastid to each daughter cell. Microtubules parallel the long axis of the plastid and are most numerous adjacent to the nucleus which becomes elongated in the future spindle axis. We conclude that the division site is a fundamental component of the cytokinetic apparatus involved in the determination of cleavage plane prior to nuclear division.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01290768
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  • 175
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    Ultrastructure of freeze-substitutedFrankia strain HFPCcI 3, the actinomycete isolated from root nodules ofCasuarina cunninghamiana (1985)
    Springer
    Protoplasma 127 (1985), S. 64-72 
    Details
    ISSN: 1615-6102
    Keywords: Actinomycete ; Casuarina ; Frankia ; Freeze-substitution ; Quick-freezing ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Frankia strain HFPCcI 3 is an actinomycete isolated from root nodules ofCasuarina cunninghamiana. In culture it exhibits typicalFrankia morphology and may produce three distinct morphological forms: branching septate hyphae, terminal or intercalary sporangia, and specialized structures termed vesicles which are the purported site of nitrogenase activity. An examination of the ultrastructure of all three morphological forms using both conventional chemical fixation (CF) and quick-freezing followed by freeze-substitution (FS) reveals some interesting differences between the two fixation methods. Unique to FS material are: 1. smooth membrane profiles; 2. lack of mesosomes; 3. lack of discernible nucleoid regions with condensed chromatin; 4. clarity of cytoplasmic elements such as ribosomes and granular bodies; 5. large cytoplasmic tubules in hyphae and young sporangia; 6. outer wall layer not widely separated from the spherical portion of the vesicle, and 7. bundles of microfilaments in vesicles. The quality of preservation after FS appears to be far superior to that obtained with CF. Accordingly the structures observed after FS are thought to represent more faithfully the structure of the living cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01273702
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  • 176
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    Ultrastructure of endopolyploid antipodals inAconitum vulparia Rchb. (1985)
    Springer
    Protoplasma 127 (1985), S. 163-170 
    Details
    ISSN: 1615-6102
    Keywords: Aconitum vulparia ; Antipodals ; Endopolyploid cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructure of the antipodals ofAconitum vulparia Rchb. was studied in mature embryo sacs. Antipodal cell wall thickness varies in different parts of the cells. The antipodals resemble transfer cells with distinctly marked wall ingrowths which are particularly well developed in the chalazal part and between the antipodals. A few plasmodesmata occur in the cell wall between the antipodals and the central cell. The cytoplasm is rich in ribosomes which occur free or bound to the membranes of the well developed endoplasmic reticulum. Only in the micropylar region of the cells are some larger vacuoles found. The antipodals contain numerous mitochondria, plastids and apparently active dictyosomes. Vesicles with electron dense contents, microbodies, multivesicular bodies as well as lipid droplets and small multiple concentric cisternae are also present in the cytoplasm. The giant endopolyploid nuclei have lobed outlines, especially at the chalazal side of the nuclei. Ultrastructural features, especially the occurrence of numerous free ribosomes and the development of extensive rough endoplasmic reticulum, suggest high metabolic activity in the growing and differentiating antipodals of this species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01276260
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  • 177
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    Relationships between structure and motility ofAlbizzia motor organs: Changes in ultrastructure of cortical cells during dark-induced closure (1985)
    Springer
    Protoplasma 128 (1985), S. 72-79 
    Details
    ISSN: 1615-6102
    Keywords: Albizzia ; Cytoskeleton ; Membranes ; Motility ; Pulvinus ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Paired leaflets ofAlbizzia julibrissin spread apart (open) in the daytime and fold together (close) at night. We examined the structure of cells in open and closedAlbizzia motor organs (pulvini) to identify reversible changes in structure associated with motility. Pulvini were fixed in glutaraldehyde and stained using conventional methods. The pulvinus has a central vascular cylinder bordered by thick-walled collenchyma cells, in turn surrounded by an endodermis and many layers of cortical parenchyma. Cortical cells in the extensor undergo large changes in shape during leaflet closure linked with: formation of wall infoldings, development of a large periplasmic space filled with fibrils and membranes, development of lobes on the nucleus, evagination of the nuclear outer envelope membrane, break-up of the large central vacuole to form many small vacuoles, and linking of the plasmalemma to inner regions of the cytoplasm by microfilaments. Cortical cells in the flexor, by contrast, remain relatively stable during leaflet movement. Microtubules are present near the plasmalemma in both extensor and flexor cells; in the extensor, spherical coated vesicles are located near the microtubules. The possible function of these structures in regulating intracellular shuttling processes is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01273238
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  • 178
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    The initiation, development and structure of root nodules inElaeagnus angustifolia L. (Elaeagnaceae) (1985)
    Springer
    Protoplasma 128 (1985), S. 107-119 
    Details
    ISSN: 1615-6102
    Keywords: Actinorhizal root nodules ; Development ; N2 fixation ; Elaeagnus ; Frankia ; Symbiosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A correlated light and electron microscopic study was undertaken of the initiation and development of root nodules of the actinorhizal tree species,Elaeagnus angustifolia L. (Elaeagnaceae). Two pure culturedFrankia strains were used for inoculation of plants in either standing water culture or axenic tube cultures. Unlike the well known root hair infection of other actinorhizal genera such asAlnus orMyrica the mode of infection ofElaeagnus in all cases was by direct intercellular penetration of the epidermis and apoplastic colonization of the root cortex. Root hairs were not involved in this process and were not observed to be deformed or curled in the presence of the actinomyceteFrankia. In response to the invasion of the root, host cells secreted a darkly staining material into the intercellular spaces. The colonizingFrankia grew through this material probably by enzymatic digestion as suggested by clear dissolution zones around the hyphal strands. A nodule primordium was initiated from the root pericycle, well in advance of the colonizingFrankia. No random division of root cortical cells, indicative of prenodule formation was observed inElaeagnus. As the nodule primordium grew in size it was surrounded by tanninised cells of a protoperiderm. The endophyte easily traversed this protoperiderm, and once inside the nodule primordium cortex ramified within the intercellular spaces at multiple cell junctions. Invasion of the nodule cortical cells occurred when a hyphal branch of the endophyte was initiated and grew through the plant cell wall, again by apparent enzymatic digestion. The plant cell plasmalemma of invaded cells always remained intact and numerous secretory vesicles fused with it to encapsulate the advancingFrankia within a fibrous cell wall-like material. Once within the host cell some endophyte cells began to differentiate into characteristic vesicles which are the presumed site of nitrogen fixation. This study clearly demonstrates that alternative developmental pathways exist for the development of actinorhizal nitrogen-fixing root symbioses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01276333
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  • 179
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    Ultrastructure of the flagellar apparatus inPleurochrysis (classPrymnesiophyceae) (1985)
    Springer
    Protoplasma 125 (1985), S. 24-35 
    Details
    ISSN: 1615-6102
    Keywords: Coccolithophorid ; Flagellar apparatus:Pleurochrysis ; Prymnesiophyceae ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructure of the flagellar apparatus of aPleurochrysis, a coccolithophorid was studied in detail. Three major fibrous connecting bands and several accessory fibrous bands link the basal bodies, haptonema and microtubular flagellar roots. The asymmetrical flagellar root system is composed of three different microtubular roots (referred to here as roots 1,2, and 3) and a fibrous root. Root 1, associated with one of the basal bodies, is of the compound type, constructed of two sets of microtubules,viz. a broad sheet consisting of up to twenty closely aligned microtubules, and a secondary bundle made up of 100–200 microtubules which arises at right angles to the former. A thin electron-dense plate occurs on the surface of the microtubular sheet opposite the secondary bundle. The fibrous root arises from the same basal body and passes along the plasmalemma together with the microtubular sheet of root 1. Root 2 is also of the compound type and arises from one of the major connecting bands (called a distal band) as a four-stranded microtubular root and extends in the opposite direction to the haptonema. From this stranded root a secondary bundle of microtubules arises at approximately right angle. Root 3 is a more simple type, composed of at least six microtubules which are associated with the basal body. The flagellar transition region was found to be unusual for the classPrymnesiophyceae. The phylogenetic significance of the flagellar apparatus in thePrymnesiophyceae is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01297347
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  • 180
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    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
    Keywords: Inner ear ; Loop-tail mouse ; Ultrastructure ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00454355
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  • 181
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    293. Die Struktur des normalen und entziindlich veränderten Peritoneums des Menschen — eine elektronenmikroskopische Studie (1985)
    Springer
    Langenbeck's archives of surgery 366 (1985), S. 703-703 
    Details
    ISSN: 1435-2451
    Keywords: Ultrastructure ; Peritoneum ; Bacterial peritonitis ; Ultrastruktur ; Peritoneum ; Bakterielle Peritonitis ; Rasterelektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Studienergebnisse über eine dreijährige rasterelektronenmikroskopische and transmissionselektronenmikroskopische Untersuchung des Peritoneums ergaben, daß bei Patienten mit bakterieller Peritonitis die Mesothelzellen abgerundet sind, keine langen Mikrovilli im Peritoneum parietale ausgebildet werden, jedoch auf der Oberfläche Fibrinablagerungen, Epithelaufbrüche und Kollagenfasern feststellbar sind. Die Abwehrmechanismen bei Peritonitis beginnen mit Kontraktion der Mesothelzellen and Bildung von Intercellularspalten Bowie Stomata. Bei fortgeschrittener Peritonitis kommt es zur Destruktion des Mesothels mit Epithelaufbrüchen and Mobilisation von Epithelzellen zum Zwecke der Phagocytose.
    Notes: Summary The human peritoneum was studied by transmission and scanning electron microscopy, which demonstrated oval-shaped mesothelial cells, disappearance of the long microvilli at the parietal peritoneum, fibrinous membranes, collagenous fibrillae, and epithelial cracks in cases of bacterial peritonitis. The defense mechanism begins with mesothelial cell contractions and then formation of intercellular gaps and stomata. In advanced peritonitis, the mesothelial cells disintegrate with cracks and are finally mobilized for phagocytosis. After continuous peritoneal lavage, the cellular structures of the human peritoneum appear almost normal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01836891
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  • 182
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    Das Rückstandsverhalten von Chloramphenicol nach intramuskulärer Applikation beim Schwein (1985)
    Springer
    European journal of nutrition 24 (1985), S. 113-119 
    Details
    ISSN: 1436-6215
    Keywords: Chloramphenicol ; pharmacokinetics ; residue ; pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: 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.
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02020458
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  • 183
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    Effect of brief vascular perfusion on the ultrastructure and activity of mitochondria isolated from the rat heart (1985)
    Springer
    Cell & tissue research 240 (1985), S. 247-249 
    Details
    ISSN: 1432-0878
    Keywords: Heart ; Mitochondria ; Perfusion ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Mitochondria isolated from heart tissue after a 1-min perfusion with Hanks medium were found to have significantly lower rates of State-3 respiration and respiratory control ratios compared to mitochondria isolated from non-perfused hearts. Examination of the mitochondrial preparations by electron microscopy revealed that a large proportion of the mitochondria isolated from perfused heart tissue were swollen and broken compared to mitochondria from non-perfused hearts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217581
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  • 184
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    Effects of temperature and bright light on myeloid bodies in the retinal pigment epithelium of the newt, Notophthalmus viridescens (1985)
    Springer
    Cell & tissue research 241 (1985), S. 623-628 
    Details
    ISSN: 1432-0878
    Keywords: Retinal pigment epithelium ; Myeloid bodies ; Morphometry ; Ultrastructure ; Endoplasmic reticulum ; Lighting effects ; Temperature effects ; Urodeles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Myeloid bodies (MBs) are specialized regions of endoplasmic reticulum which occur in the retinal pigment epithelium of a number of vertebrate species. In the newt, Notophthalmus viridescens, the effects of temperature and brief exposure to bright flashed-light on myeloid bodies have been studied. Morphometric analysis has shown that in animals sampled at 06.30 h, myeloid body sectional area remained unchanged in animals maintained in the cold (1°C), compared with control animals at 15°C, whereas phagosome area was significantly increased. At higher temperatures (30° C), myeloid body area was observed to decline from control values, while phagosome area was substantially increased. During the first 2 h of the light phase of a normal (15° C) 12:12 LD lighting cycle, myeloid-body sectional area dropped significantly from values recorded in the latter part of the dark phase. This reduction of MB area at the normal time of “lights-on” was greatly reduced when animals experienced an extended period of darkness. When animals experiencd a bright flashed-light at the normal time of “lights-on”, followed by a period of extended darkness, reduction in MB area was less pronounced when compared to cycled control animals. These results are discussed in the context of the hypothesis (Yorke and Dickson 1984) that MBs represent a temporary storage site for lipids entering the pigment epithelium after phagocytosis of shed outer segment tips, prior to their permanent storage in lipid droplets. These results are consistent with the proposal that myeloid bodies are removed from the cytoplasm of the newt pigment epithelium by metabolic processes which are active over time, but accelerated by increased temperatures or the presence of light.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214584
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  • 185
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    Ultrastructural and immunohistochemical studies on non-ciliated cells of the tracheal epithelium of normal, phenobarbital-treated, and 3-methylcholanthrene-treated mice (1985)
    Springer
    Cell & tissue research 240 (1985), S. 501-504 
    Details
    ISSN: 1432-0878
    Keywords: Non-ciliated tracheal cell ; Smooth endoplasmic reticulum ; Ultrastructure ; Cytochrome P-450 ; Immunohistochemistry ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Non-ciliated SER-rich cells of the tracheal epithelium of normal, phenobarbital-treated and 3-methylcholanthrene-treated mice were studied ultrastructurally and immunohistochemically. The apical portion of these cells protrudes into the tracheal lumen, especially in the mice treated with the two compounds, and the apical cytoplasm is filled with numerous tubular elements of SER. Besides, the non-ciliated cells of 3-methylcholanthrene-treated mice show a strong positive reaction to the antiserum against microsomal cytochrome P-450 of liver. These findings support the concept that the non-ciliated tracheal cell may be involved in the metabolism of endogeneous and exogeneous chemical compounds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222368
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  • 186
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    Electron-microscopic study of the collagen fibrils of the rat tail tendon as revealed by freeze-fracture and freeze-etching techniques (1985)
    Springer
    Cell & tissue research 240 (1985), S. 529-534 
    Details
    ISSN: 1432-0878
    Keywords: Collagen fibril ; Freeze-fracture ; Tail tendon ; Rat ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the collagen of rat tail tendon was investigated by the freeze-fracture technique. Collagen fibers were pretreated with the digestive enzymes, α-amylase, elastase and collagenase to remove matrix substances. Some of the samples were etched for 20 min. Fibrils had an average diameter of 318±12 nm and a banded structure with a mean periodicity of 64.2±0.9 mm; the banding was most marked in α-amylase/elastase-treated specimens, although the periodicity was independent of pretreatment. Microfibrils were well-displayed following α-amylase/elastase and collagenase pretreatments. A difference in the diameters of microfibrils was, however, observed between etched specimens (8.3±0.3 nm) and those prepared by other experimental methods (11.4±0.5 nm). In replicas of collagenase-treated and etched specimens, the interconnecting filaments in the interfibrillar region formed a network that was continuous with the microfibrils of collagen fibrils. The diameter of the interconnecting filaments was the same as that of microfibrils. Microfibrillar bundles were observed in the interfibrillar region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00216341
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  • 187
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    Functional differences between two structurally distinct types of steroidogenic cell in the avian adrenal gland (1985)
    Springer
    Cell & tissue research 240 (1985), S. 561-567 
    Details
    ISSN: 1432-0878
    Keywords: ACTH ; Adrenal zonation ; Birds ; Corticosterone ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary There are two regions of steroidogenic cells in the duck adrenal gland. An outer, subcapsular zone (SCZ), consisting of cells with irregularly shaped nuclei, shows relatively little smooth endoplasmic reticulum and mitochondria with shelf-like cristae. This region surrounds the inner zone (IZ) of the gland which is comprised of smaller cells with rounded nuclei, a more abundant smooth endoplasmic reticulum and mitochondria with tubular cristae. When samples of tissue from these distinct regions of the gland are superfused in vitro with media containing concentrations of 1–24 ACTH ranging from 100 to 1000 ng per ml (0.034 to 0.34 μM) the steroidogenic cells in both zones release corticosterone in a dose-dependent manner. The dose-responsiveness of both the SCZ and the IZ cells over this range is a complex quadratic function of the 1–24 ACTH concentration in the medium and the semilogarithmic linear portions of the dose-response curves are restricted to a narrow midrange of ACTH concentrations. Throughout the dose-response range, however, the steroidogenic cells of the IZ are more responsive to corticotropic stimulation than are the cells of the SCZ. The cells of the two zones are further distinguished by their responses to a challenge for a second time with medium containing 1–24 ACTH; the responses of the IZ cells to a second challenge were greater than those of the SCZ cells, and at a high concentration of ACTH the SCZ slices showed no significant second response.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00216345
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  • 188
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    Electron-microscopic observations of the gravity receptor epithelia of normal and spinner juvenile Octopus maya (1985)
    Springer
    Cell & tissue research 240 (1985), S. 701-704 
    Details
    ISSN: 1432-0878
    Keywords: Maculae ; Cephalopods ; Statolith defects ; Ultrastructure ; Spinner octopus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Light and electron microscopy of the gravity receptor epithelia (maculae) of statocysts of normal and “spinner” juvenile Octopus maya showed differences between the structures of the hair cells, supporting cells, and afferent neurons of these cephalopods. The maculae of spinner animals were approximately 30% smaller in their surface area and had 40% fewer hair cells. Moreover, the average distance between randomly-chosen hair bundles in scanning electron micrographs of maculae of normal animals was significantly greater (4.33±6.47 μm) than those of maculae of spinner animals (3.38±4.90 μm; P〈0.0001). The sectional area of the supporting cell's microvilli in spinners maculae was larger (0.16±0.18 μm) than those of normal (0.10±0.10 μm; P〈0.0001) O. maya. The morphological differences observed between certain structural components of the maculae of normal and spinner O. maya may be related to the absence and/or malformation of the neuroepithelial suprastructures in spinners. This may have direct or indirect effects related to their inability to orient to gravity with these organs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00216358
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  • 189
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    Quantitative analysis of estradiol-17β-induced changes in the ultrastructure of the liver of the male zebrafish, Brachydanio rerio (1985)
    Springer
    Cell & tissue research 242 (1985), S. 377-382 
    Details
    ISSN: 1432-0878
    Keywords: Liver ; Hepatocytes ; Ultrastructure ; Estradiol ; Vitellogenesis ; Teleosts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Hepatocytes of male zebrafish, Brachydanio rerio, were studied by means of light- and electron-microscopy, following a period of maximally 16 days of in-vivo treatment with estradiol-17β. The responsiveness of the male hepatocytes to this female sex steroid was investigated by use of morphometric methods. The results of this investigation show that the responsiveness was most obvious between 2 and 16 days, as revealed by an increase in cell size, accompanied by a proliferation of the granular endoplasmic reticulum and the Golgi complex. In addition, accumulations of glycogen granules, which are characteristic of hepatocytes in untreated males, had disappeared and lipid droplets had accumulated. These experimentally induced changes in the morphology of the male hepatocyte closely resemble those described for the female hepatocyte during the sexual cycle. It is concluded that the hepatocytes of male zebrafish can be stimulated by estradiol-17β to produce vitellogenin and that in female zebrafish this steroid is a key sex hormone responsible for vitellogenin production by the liver during the natural sexual cycle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214551
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  • 190
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    The effect of clomiphene citrate on blastocyst development and implantation in the rabbit (1985)
    Springer
    Cell & tissue research 241 (1985), S. 495-503 
    Details
    ISSN: 1432-0878
    Keywords: Embryo transfer ; Ultrastructure ; Implantation ; Clomiphene citrate, effects ; Blastocyst, development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The induction of ovulation with clomiphene citrate (CC) in human patients results in a high ovulation rate but achieves a relatively low pregnancy rate. To clarify the possible role of CC in interfering with the normal reproductive physiology and embryology, we have used our rabbit model and transferred 4-day-old blastocysts from untreated donors to CC-treated pseudopregnant recipients and from CC-treated donors to untreated pseudopregnant recipients to study embryonic development and implantation. Each group was further subdivided into two subgroups, one receiving CC before and the other after ovulation. CC was administered subcutaneously in three consecutive doses of 10 mg/kg body weight. Ovulation was induced with pregnant mare serum gonadotropin (PMS) and human chorionic gonadotropin (hCG). The implantation rate of the control group, evaluated on day 8 of pregnancy, reached 62.0%. When recipients were treated with CC before ovulation, implantation rate was reduced to 18.8% (P 〈 0.0002), and to 20.0% (P 〈 0.003) when CC was administered after ovulation. The implantation rate of blastocysts transferred from donors, treated before ovulation, is 22.2% (P 〈 0.0055), however, reached 70.8% when treatment was started after ovulation. All implantations were analysed microscopically and showed normal morphological features. Our results demonstrate a potential multiple effect of CC, first on the endometrium by altering its receptivity for the implanting conceptus, second, on tubal physiology by altering egg transport, and finally on ovum maturation before ovulation interfering with development of blastocysts. These parameters may all result in rapid decrease in establishment of implantations and in turn in very low pregnancy rates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214568
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  • 191
    Electronic Resource
    Electronic Resource
    Effects of colchicine on the ultrastructure of mouse taste buds (1985)
    Springer
    Cell & tissue research 242 (1985), S. 409-416 
    Details
    ISSN: 1432-0878
    Keywords: Taste bud ; Colchicine ; Ultrastructure ; Microtubules ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Effect of colchicine on the ultrastructure of taste bud cells was studied in the mouse. In untreated mice microtubules were abundant throughout the entire cytoplasm of type-III cells, but only in the apical cytoplasm of type-I cells. After 2 h of colchicine treatment, no microtubules were observed in any taste bud cells; dense secretory granules in the apical cytoplasm of type-I cells mostly disappeared, and instead, numerous phagosomes appeared. It is suggested that colchicine causes an interruption of the transport of the secretory granules in type-I cells from the Golgi apparatus to the membrane of the apical surface, from which release occurs. In type-III cells, after 4 or 5 h of treatment, dense-cored vesicles scattered throughout the cytoplasm tended to increase in number; they were often observed to accumulate in the vicinity of the Golgi apparatus. Five hours after treatment with 5-hydroxy-l-tryptophan (5-HTP) following colchicine pretreatment, monoamine specific fluorescent cells and vesicles with highly electron-dense cores of type-III cells were still present. On the other hand, 5 h after 5-HTP treatment alone both fluorescent cells and vesicles with highly electron-dense cores had already disappeared. These observations suggest that the treatment with colchicine interrupts the transport of densecored vesicles of type-III cells to synaptic areas, in which those vesicles are presumed to discharge the neurotransmitter substance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214555
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  • 192
    Electronic Resource
    Electronic Resource
    Characterization of dendritic cells, isolated from normal and stimulated lymph nodes of the rat (1985)
    Springer
    Cell & tissue research 242 (1985), S. 469-474 
    Details
    ISSN: 1432-0878
    Keywords: Lymph node ; Antigen stimulation ; Dendritic cells ; Enzyme- and immunocytochemistry ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Non-lymphoid dendritic cells were isolated from normal and paratyphoid vaccine-stimulated lymph nodes draining the rat skin. They were studied using enzymecytochemical, immunocytochemical and electron-microscopical methods. These cells had an irregular outline and an eccentrically situated nucleus. All showed acid phosphatase activity in a central area and expressed Ia antigen on the plasma membrane. Birbeck granules were exclusively present in dendritic cells isolated from lymph nodes in the induction phase of the immune response. This observation concurs with the presence of Birbeck granules in interdigitating cells in situ during the same period of the immune response. It is concluded that the dendritic cells are the in-vitro equivalents of the non-actively phagocytizing population of interdigitating cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225411
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  • 193
    Electronic Resource
    Electronic Resource
    Organization of lymphoid tissue in the tonsilla lingualis (1985)
    Springer
    Cell & tissue research 240 (1985), S. 233-242 
    Details
    ISSN: 1432-0878
    Keywords: Lymphoid tissue ; Tonsilla lingualis ; Ultrastructure ; B- and T-lymphocytes ; Macaca fascicularis (Primates, Cercopithecoidea)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Lymphoid organs are highly organized structures made up of different tissue compartments, each with its own specific cell populations. However, the cellular elements of the lingual tonsil, which forms a significant part of Waldeyer's pharyngeal ring, are not yet documented. This study, therefore, describes the fine structure and tissue organization of tonsilla lingualis in Macaca fascicularis. Ten selected crypto-lymphatic units originating from five perfusion-fixed animals were analysed ultrastructurally. Based on the fine-structural elements contained within, the lymphoid tissue of tonsillar units could be subdivided into follicular (germinal centre) and parafollicular areas. The latter contained predominantly small lymphocytes, lymphoblasts resembling T-blasts, plasma cells, macrophages, occasional neutrophils and many reticular cells resembling fibroblasts. A distinct feature of the parafollicular area was the presence of numerous high endothelial (HEV)or postcapillary venules (PCV). The follicular areas contained many small and large lymphoid cells, mitotic cells, plasmablasts, macrophages and specialised reticular cells resembling follicular dendritic cells (FDC) with distinct desmosomal junctions. These observations show that the crypto-lymphatic units of the lingual tonsil are, in fact, organised into distinct B- and T-cell compartments with their own specific lymphoid and accessory cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217579
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  • 194
    Electronic Resource
    Electronic Resource
    Architecture of associations of minor salivary gland ducts and lymphoid follicles in Macaca fascicularis (1985)
    Springer
    Cell & tissue research 240 (1985), S. 223-232 
    Details
    ISSN: 1432-0878
    Keywords: Oral mucosa, simian ; Local mucosal immunity ; Minor salivary glands ; Duct/lymphoid follicle assemblies ; Ultrastructure ; Macaca fascicularis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Previous light-microscopic and ultra-immunohistochemical tracer studies revealed the existence of an independent local immune response of the simian oral mucosa. This local response is attributed to the presence of minor salivary gland (MSG) duct-related lymphoid tissue. Semithin sections from a total of 263 Epon-embedded tissue blocks from the labial and buccal mucosae of seven monkeys, Macaca fascicularis, were analysed light-microscopically, and 10 suitable MSG duct/follicle assemblies were investigated ultrastructurally. These duct/follicle assemblies include follicular and parafollicular compartments with distinct fine-structural elements. The follicular area or germinal centre contains numerous small and large lymphoid cells, mitotic figures, plasmablasts, macrophages, and cells resembling the follicular dendritic cells with distinct desmosomal junctions. The parafollicular area, which includes the heavily infiltrated duct wall, contains numerous small lymphocytes, T-lymphoblasts, plasma cells and reticular cells resembling fibroblasts. A distinct feature of this compartment is the presence of high endothelial venules (HEV). The presence of HEV and numerous blast cells, resembling blast-forming T-lymphocytes activated in vitro, in a specific area of the duct/follicle assembly strongly suggests that this area is structurally and physiologically identical to the thymus-dependent area of other lymphoid tissues. In other words, the duct/follicle assemblies of simian MSG contain the various specific fine-structural elements that are suitable for antigen recognition and processing. These elements are distributed in discrete compartments comparable to the B- and T-cell areas of “classical” lymphoid tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217578
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  • 195
    Electronic Resource
    Electronic Resource
    A cytochemical study of myeloid bodies in the retinal pigment epithelium of the newt Notophthalmus viridescens (1985)
    Springer
    Cell & tissue research 240 (1985), S. 641-648 
    Details
    ISSN: 1432-0878
    Keywords: Retinal pigment epithelium ; Myeloid bodies ; Ultrastructure ; Lipid metabolism ; Endoplasmic reticulum ; Cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary It has been suggested (Yorke and Dickson 1984) that myeloid bodies (MBs) in the retinal pigment epithelium (RPE) of the newt, Notophthalmus viridescens, may represent areas of endoplasmic reticulum where lipids, such as 11-cis retinal derived from phagocytized outer segment tips, accumulate prior to esterification. Experiments in which an artificial ester substrate was added during in-vitro incubations have shown that esterase activity is represented in all areas of the newt RPE endoplasmic reticulum, including sites adjacent to all MBs. In related tests in which the localization of enzyme activity was restricted to areas of the cell where there had been accumulations of naturally-occurring (endogenous) esters, the products of ester hydrolysis were restricted to profiles of endoplasmic reticulum associated with lipid droplets, and with the interior of about 20% of those MBs that appeared completely circular in sections. This enzyme activity was not associated with other MB configurations. Results from endogenous-ester hydrolysis were identical to those obtained after staining with ZIO. This ZIO-reactivity was not affected by pre-incubation with agents that blocked or protected sulphydryl groups, and ZIO-reactive sites associated with MBs did not form complexes with digitonin. These observations suggest that MBs are a site of lipid-ester formation, but that they do not represent unique intracellular areas for this activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00216352
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  • 196
    Electronic Resource
    Electronic Resource
    Morphometry of muscle fibre types in the carp (Cyprinus carpio L.) (1985)
    Springer
    Cell & tissue research 241 (1985), S. 193-201 
    Details
    ISSN: 1432-0878
    Keywords: Fish ; Muscle fibre types ; Ultrastructure ; Morphometry ; Twitch characteristics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural parameters of muscle fibre types of the carp (Cyprinus carpio L.) were measured and compared with their contractile properties. In red fibres, which are slower than pink fibres, the relative length of the junction between the T system and the sarcoplasmic reticulum (T-SR junction) is smaller and the Z lines are thicker than in pink fibres. Pink fibres have a smaller relative length of T-SR junction than white fibres from the axial muscles. The two types of red fibres present in carp muscle also differ in their relative lengths of T-SR junction. Significant differences in the relative areas of the SR were not found. The relative volume of myofibrils in red fibres is two-thirds that in pink fibres, a difference that is not reflected in the maximal isometric tetanic tensions of these types. Red fibres, which are less easily fatigued than pink fibres, have larger relative volumes of subsarcolemmal and intermyofibrillar mitochondria. Small pink fibres have a larger relative volume of subsarcolemmal mitochondria than large pink fibres, but have a similar relative volume of intermyofibrillar mitochondria. Small and large pink fibres differ in the relative volumes of their membrane systems, but have similar relative lengths of T-SR junction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214641
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  • 197
    Electronic Resource
    Electronic Resource
    Ultrastructural localization of the iodination centre in the endostyle of the adult amphioxus (Branchiostoma lanceolatum) (1985)
    Springer
    Cell & tissue research 241 (1985), S. 267-273 
    Details
    ISSN: 1432-0878
    Keywords: Endostyle ; Autoradiography ; Ultrastructure ; Iodination ; Amphioxus, adult (Branchiostoma lanceolatum)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The site of iodination in the endostyle of the adult amphioxus was examined by light-and electron-microscopic autoradiography. In accordance with previous studies, light-microscopic autoradiography showed a distinct accumulation of autoradiographic grains at the apical end of epithelial cells in the lateral part of the endostyle. In the electron microscope two distinct cellular zones were identified in an approximate position of the light-microscopic zone 5. Zone 5a, not previously recognized, was adjacent to zone 4 and consisted of six to nine rows of cells free of characteristic granules. Cells in zone 5b contained large “mucous” granules and had, in previous ultrastructural studies, been identified as belonging to the typical zone 5. Four or less incomplete rows of granule-containing cells, not observed in previous studies, marked the border between zones 5b and 6. After incubation in 125I for 5 min, electron-microscopic autoradiography showed a selective concentration of label to zone 5a, which, thus, corresponds to the iodination centre seen in the light microscope. The grains were associated with cilia and microvilli in the lumen. After longer incubation times (30, 60, 90 min) grains were still concentrated at the surface of zone 5a but were also associated with the surface of zones 5b and 6. Grains were also located over the cytoplasm of all three zones. They were associated with vesicles and lysosome-like structures, suggesting secondary uptake of labelled products by endocytosis. Methimazole, an inhibitor of peroxidase, abolished the autoradiographic reaction. In conclusion, the site of iodination in the endostyle of amphioxus is located in zone 5a, which has not previously been ultrastructurally defined. Iodination in the endostyle is an extracellular process, but secondary uptake by endocytosis appears to occur.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217170
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  • 198
    Electronic Resource
    Electronic Resource
    Ultrastructural autoradiographic localization of serotonin in the pituitary of a teleost fish, Poecilia latipinna (1985)
    Springer
    Cell & tissue research 240 (1985), S. 489-492 
    Details
    ISSN: 1432-0878
    Keywords: Serotonin ; Pituitary ; Autoradiography ; Ultrastructure ; Teleosts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Light- and electron-microscopic autoradiographic studies of pituitaries of the molly Poecilia latipinna, after their incubation with tritiated serotonin, revealed the presence of labelled cells in the proximal pars distalis, together with cell processes or nerve fibres throughout all regions of the gland except the prolactin cell zone. The serotonincon-centrating cells and most of the fibres contained small dense-cored vesicles, but some labelled fibres contained larger granules similar in ultrastructure to those of vasotocinergic fibres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222365
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  • 199
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    Electronic Resource
    Ultrastructural changes associated with K+-evoked peptide secretion from a neurohemal organ of the crab, Cardisoma carnifex (1985)
    Springer
    Cell & tissue research 242 (1985), S. 67-73 
    Details
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Sinus gland ; Ultrastructure ; Potassium stimulation ; Crustacea ; Hormone release
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron-microscopic comparison of K+-stimulated and unstimulated crab sinus glands reveals significant differences in neurosecretory terminal morphology. Sinus glands exposed to elevated K+ saline for increasing periods of time show increasing numbers of exocytotic release profiles, vacuoles, and multilamellate bodies, and a decrease in the number of microvesicles within 10 μm of release sites. These morphological changes are well correlated with secretion of red-pigment-concentrating hormone, as determined by bioassay of perfusate from the individual preparations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225564
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  • 200
    Electronic Resource
    Electronic Resource
    Implementation of periodic acid-thiosemicarbazide-silver proteinate staining for ultrastructural assessment of muscle glycogen utilization during exercise (1985)
    Springer
    Cell & tissue research 242 (1985), S. 229-232 
    Details
    ISSN: 1432-0878
    Keywords: Skeletal muscles ; Ultrastructure ; Exercise ; Glycogen ; Humans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Distribution of glycogen particles in semithin and ultrathin sections of biopsy samples from human muscles subjected to either short- or long-term running were investigated using PAS and Periodic Acid-ThioSemiCarbazide-Silver Proteinate (PA-TSC-SP) staining methods. Glycogen particles were predominantly found immediately under the sarcolemma or aligned along the myofibrillar Iband. After long-term exhaustive exercise type-1 fibers with a few or no glycogen particles in the core of the fibers were frequently observed. The subsarcolemmal glycogen stores of these “depleted” type-1 fibers were about three times as large as after exhaustive short-time exercise. Another indication of utilization of subsarcolemmal glycogen stores during anaerobic exercise was that many particles displayed a pale, rudimentary shape. This observation suggests fragmental metabolization of glycogen. Thus, depending on type of exercise and type of fiber differential and sequential glycogen utilization patterns can be observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225582
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