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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 62 (1984), S. 183-186 
    ISSN: 1432-1440
    Keywords: Glutathione ; GSH-peroxidase ; GSH S-aryltransferase ; Human gastric mucosa ; Gastric carcinoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The γ-glutamyl-transferase activity, the total glutathione content, the GSH-peroxidase activity, and the GSH S-transferase activity using an aryl substrate were estimated in the S9 fraction of gastric biopsy specimens taken from patients with normal stomach morphology (n=24), acute gastritis (n=15), chronic-atrophic gastritis (n=10), gastric ulcer (n=9), and carcinoma of the stomach (n=12). The total glutathione content of normal gastric mucosal specimens was significantly higher than that of human liver biopsy specimens, whereas the GSH-peroxidase and the GSH S-aryltransferase activities were much lower than those found in the liver. Specimens of gastric ulcer had significantly lower enzyme activities of GSH-peroxidase and GSH-aryltransferase, whereas gastric cancer tissue had significantly lower concentrations of total glutathione. The intraindividual comparison of tumorous and non-tumorous tissue showed a consistent decrease of total glutathione as well as of GSH-aryltransferase activity in carcinomatous tissue.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0738
    Keywords: Bromobenzene ; Diethyl dithiocarbamate ; Dimethyl sulfoxide ; Irreversible binding ; Rat liver microsomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The irreversible binding of [14C]-bromobenzene to rat liver microsomal protein in vitro was inhibited by dithiocarb and DMSO. Dithiocarb suppressed this binding in a time- and concentration-dependent manner (I50 = 4.5 10−5 M). DMSO reduced the degree of covalent binding by 61% from 5 x 10−5 M to 8 × 10−4 M. Dithiocarb was also effective in inhibiting irreversible binding of bromobenzene to liver protein in vivo. Our results are consistent with the hypothesis that dithiocarb exerts its antihepatotoxic efficacy by depressing microsomal mixed-function oxidase activity.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Archives of toxicology 41 (1978), S. 79-88 
    ISSN: 1432-0738
    Keywords: Diethyldithiocarbamate ; Cysteine ; Cysteamine ; d-Penicillamine ; Dimercaprol ; Thiazolidine carbonic acid ; Thioctic acid ; Carbontetrachloride ; Allyl alcohol ; Bromobenzene ; Thioacetamide ; Dimethylnitrosamine ; Hepatitis, toxic ; Aminotransferases ; Mixed function oxidases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In mice, diethyldithiocarbamate (dithiocarb, 100 mg/kg i.p.) completely prevented the increments of serum enzyme activities (GOT, GPT, SDH) induced by oral administration of carbon tetrachloride (0.1 ml/kg), allyl alcohol (0.05 ml/kg), bromobenzene (0.25 ml/kg), and thioacetamide (50 mg/kg). In this respect, cysteine (200 mg/kg i.p.) was active against CCl4 and bromobenzene, cysteamine (100 mg/kg i.p.) against CCl4 and allyl alcohol, penicillamine (100 mg/kg i.p.) against allyl alcohol, thiazolidine carbonic acid (100 mg/kg i.p.) against bromobenzene, and thioctic acid (100 mg/kg i.p.) against allyl alcohol and thioacetamide. Dimercaprol (100 mg/kg i.p.) had a weak antidotal effect only against allyl alcohol poisoning. None of the tested antidotes inhibited serum enzyme elevations evoked by dimethyl nitrosamine (100 mg/kg p.o.). These findings prove the antihepatotoxic activity of diethyldithiocarbamate to be superior to that of all other thio compounds under observation. The lowest dose of dithiocarb active against carbon tetrachloride was 25 mg/kg i.p. The dose-response curves for serum-enzyme elevations induced by carbon tetrachloride (0.1–4 ml/kg p.o.) were shifted to the right under the influence of dithiocarb indicating a competitive antagonism. Dithiocarb (100 mg/kg i.p.) depressed the p-hydroxylation of aniline in the 9000 x g liver homogenate supernatant of mice by about 55%. Thus, the antihepatotoxic activity of dithiocarb seems to be the consequence of a decreased oxidase activity.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Archives of toxicology 48 (1981), S. 293-297 
    ISSN: 1432-0738
    Keywords: Intoxication ; Paraquat ; Ethanol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Ein 44 jähriger Patient mit bekanntem chronischen Alkoholabusus verstarb 24 Std. nach oraler Einnahme von 80 ml einer 20% igen Paraquatlösung (Gramoxone) im akuten Lungenödem. Behandlung mit Glucocorticoiden, forcierter Diurese, Kohle-Hämoperfusion und Hämodialyse konnten den akuten letalen Ausgang dieser Paraquat-Vergiftung nicht verhindern. Die hohe initiale Plasmakonzentration von 2.56 mg/1 fiel unter der Hämoperfusion und Hämodialyse rasch auf 1.19 mg/l ab. Bei Mäusen, denen 1 Woche lang 5% Alkohollösung anstelle von Trinkwasser angeboten wurde, nahm die LD50 von Paraquat auf 80 (63–102) mg/kg p.o. gegenüber 170 (126–229) mg/kg p.o. bei Kontrollen ab. Der klinische Vergiftungsfall sowie die Tierversuche lassen vermuten, daß Alkohol in der Lage ist, die akute Toxizität von Paraquat zu verstärken.
    Notes: Abstract Oral ingestion of about 80 ml of a 20% solution of paraquat (Gramoxone) by a 44 years-old male alcoholic was followed by an acute edema of the lungs and death within 24 hrs. The administration of corticosteroids as well as the employment of forced diuresis charcoal hemoperfusion and hemodialysis did not prevent this acute lethal outcome. The very high initial plasma concentration of 2.56 mg/l dropped quickly after hemoperfusion and dialysis to 1.19 mg/1. In mice ingesting a 5% ethanol solution for one week the LD of paraquat was diminished to 80 (63–102) mg/kg p.o. as compared to 170 (126–229) mg/kg p.o. in controls indicating that alcohol is able to enhance the acute toxicity of paraquat.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 10 (1976), S. 273-282 
    ISSN: 1432-1041
    Keywords: Pharmacokinetics ; ascorbic acid ; sustained release form ; protein binding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetic characteristics of ascorbic acid have been investigated in normal adult volunteers, using a two-compartment open model. After oral administration in a normal gelatine capsule the bioavailability of ascorbic acid was 69%. It was 98% when a sustained-release preparation was given in an identical capsule. During daily oral intake of ascorbic acid 1 g in the sustained-release form blood levels reached the equilibrium state within 3 days. Daily doses of ascorbic acid 1 g resulted in tissue saturation in 7 days, with a profound change in the pharmacokinetics of the vitamin. The binding of ascorbic acid to plasma proteins was low (≃24%). Its significance for the pharmacokinetic behaviour of the drug is discussed.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    British journal of dermatology 145 (2001), S. 0 
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background While great efforts have been made in recent years to develop in vitro methods for assessing skin irritation potential, there are relatively few data that correlate in vitro data with in vivo data. Objectives To expand our previously reported investigations on in vitro vs. in vivo correlation of a series of homologous N-alkyl sulphates of different alkyl chain length to include primary skin irritants of different chemical classes. Methods Anionic surfactants (three different sodium alkyl sulphonates and sodium lauryl sulphate), cationic surfactants (three alkyl trimethyl ammonium bromides), non-ionic surfactants (polyoxyethylene-20-cetyl ether and Tween 20), benzoic acid, dimethyl sulphoxide and phenol were chosen as model irritants. A spontaneously immortalized human keratinocyte line, HaCaT, was used as an in vitro model to predict the cutaneous irritation. The end-point used to assess toxicity was uptake of the vital dye neutral red (NR) 24 h after dosing. The cytotoxicity data from these assays were compared with the irritant responses (as evaluated by measurement of erythema and transepidermal water loss) obtained after 24-h application of the same compounds (100 µL of 20 mmol L−1 aqueous solution) to the volar forearm of human volunteers. Results All tested irritants had cytotoxic effects as demonstrated by a decreased NR uptake, which showed a clear dose–response relationship. Concentrations resulting in 50% inhibition of NR uptake (IC50) ranged from 8 µmol L−1 (hexadecyl trimethyl ammonium bromide) to 328 mmol L−1 (dimethyl sulphoxide). We found a good overall correlation between in vitro cytotoxicity (NR uptake IC50 values) and in vivo irritation potential in humans. Only the high molecular weight compounds Tween 20 and polyoxyethylene-20-cethyl ether were problematic, as their irritation potential was overestimated by the in vitro assay. This non-conformity of these high molecular weight (〉 1000) compounds was expected, and can be largely attributed to the epidermal permeability barrier. The epidermal barrier, which greatly limits the percutaneous penetration of xenobiotics in vivo, does not exist in cell culture models. Conclusions The in vitro cytotoxicity model is a useful screening tool, but data should be interpreted critically and require confirmation by appropriate in vivo studies.
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  • 7
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    British journal of dermatology 130 (1994), S. 0 
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Summary A spontaneously immortalized human keratinocyte line, HaCaT, was used as an in vitro model to predict the cutaneous irritation of anionic surfactants. For this purpose, a number of sodium salts of N-alkyl sulphates with hydrocarbon chain lengths varying between C8 and C16 were studied for possible cytotoxic effects. The endpoints used to assess toxicity were uptake of the vital dye neutral red (NR) and cell morphology criteria 24 h after dosing. A linear proportionality between keratinocyte number and NR uptake was established. All tested surfactants had cytotoxic effects as demonstrated by a decreased NR uptake, which showed a clear dose–response relationship. Concentrations resulting in 50% inhibition of NR uptake (IC-50) ranged from 0·15 mmol (sodium lauryl sulphate, C12) to 1·23 mmol (sodium octyl sulphate, C8). The in vitro cytotoxicity data were highly reproducible when the test was repeated after several weeks. The cytotoxicity data from these assays were compared with the irritant responses (as evaluated by measurement of erythema and transepidermal water loss) obtained after 24 h application of the same compounds (300 μ1 of 20 mmol aqueous solution) to the volar forearm of human volunteers. There were significant linear correlations between the IC-50 values and both barrier damage (transepidermal water loss) and erythema (as evaluated by skin colour reflectance measurements). For the test substances, however, the sensitivity of the in vitro system was between 10 and 100 times higher than that observed in human skin in vivo. This quantitative difference can largely be ascribed to the effective permeability barrier of normal human skin in vivo, which protects living keratinocytes from the cytotoxic effects of surfactant molecules.The results indicate that normal human keratinocytes in culture are a promising screening method for predicting the irritation potential of anionic surfactants. Confirmation, however, has still to be obtained by appropriate in vivo testing in human volunteers.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Journal of cancer research and clinical oncology 107 (1984), S. 238-241 
    ISSN: 1432-1335
    Keywords: Colon ; Rectum ; Adenocarcinoma ; Glutathione ; GSH S-transferase ; GSH peroxidase-γ-Glutamyltranspeptidase ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A high content of total glutathione and high activities of both GSH S-aryltransferase (CDNB) and GSH peroxidase were found in different segments of the human intestinal mucosa comparable to findings in human gastric mucosa. Intraindividual comparisons of tumorous and nontumorous tissue specimens in patients with adenocarcinomas of the colon and rectum revealed no marked differences in their glutathione content and enzyme activities except in the sigma, where we found significantly lower GSH concentrations and higher GSH S-aryltransferase activities in the carcinomatous tissue. γ-Glutamyl-transpeptidase activity, a marker of neoplastic cell growth in experimental hepatocarcinogenesis, did not differ between tumorous and nontumorous tissue areas. The presence and high activity of the GSH-dependent enzyme system in different segments of the human intestinal mucosa may reflect its role in the defense against toxic and putative carcinogenic xenobiotics entering the body via the gastrointestinal tract.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Archives of toxicology 27 (1970), S. 53-66 
    ISSN: 1432-0738
    Keywords: Norepinephrine ; Carbon Tetrachloride ; Allyl Alcohol ; Liver Damage ; Serum Transaminases ; Noradrenalin ; Tetrachlorkohlenstoff ; Allylalkohol ; Leberschädigung ; Serumtransaminasen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An Ratten kam es nach CCl4 (0,1 und 0,5 ml/kg i.p.) und Allylalkohol (0,01 und 0,02 ml/kg i.p.) zu Aktivitätssteigerungen der Serumfermente GOT, GPT und GLDH, zu einer Bromsulfaleinretention, einer Erhöhung der Lebertriglyceride und zu Nekrosen der Leber. Noradrenalin (0,025–1,0 mg/kg i.m.) erhöhte ebenfalls die Aktivität der Serumtransaminasen; diese Wirkung war dosisabhängig und begann im Falle der SGOT bei 0,025 mg/kg, im Falle der SGPT bei 0,25 mg/kg Noradrenalin. Histologisch fanden sich nach Noradrenalin, beginnend bei 0,025 mg/kg, Nekrosen des Myokards, deren Schwere mit der Dosis zunahm. Aktivitätserhöhungen der GLDH, Einschränkungen der Bromsulfaleinprobe und lichtoptisch nachweisbare Schädigungen der Leber traten dagegen erst nach 1 mg/kg Noradrenalin auf; diese Dosis war bereits für 42% der Tiere tödlich. Der Quotient SGOT/SGPT (De Ritis), der in den Kontrollversuchen 5,8±0,5 betrug, war nach CCl4 sowie Allylalkohol erniedrigt, in den Versuchen mit Noradrenalin dagegen auf das Doppelte bis Dreifache erhöht. Dieser Befund spricht ebenso wie das histologische Untersuchungsergebnis dafür, daß die durch Noradrenalin freigesetzten Transaminasen aus dem Herzen stammen. Ein Anstieg der Serumtransaminasen allein ist also kein ausreichender Beweis für eine Schädigung der Leber. Nach 0,1 und 0,25 mg/kg Noradrenalin kam es zu keiner Verstärkung der Hepatotoxicität von CCl4 bzw. Allylalkohol; bei allen Parametern fanden sich höchstens additive Wirkungen. Durch 1 mg/kg Noradrenalin wurden dagegen einige Wirkungen der Lebergifte potenziert (Transaminasenanstieg nach CCl4 und Allylalkohol, Erhöhung der GLDH sowie histologische Leberveränderungen nach Allylalkohol). Noradrenalin verstärkt also an Ratten die Wirkung hepatotoxischer Agentien erst in einer Dosis, in der es selbst bereits die Leber schädigt.
    Notes: Abstract In rats, treatment with CCl4 (0.1 and 0.5 ml/kg i.p.) or allyl alcohol (0.01 and 0.02 ml/kg i.p.) leads to elevated serum levels of GOT, GPT and GLDH, retention of serum bromsulfalein, an increase in liver triglycerides, and hepatic necroses. Norepinephrine (0.025 to 1.0 mg/kg i.m.) also produces an increase in serum transaminase activity. This effect is dose dependent. In this regard, the lowest effective dose of norepinephrine was found to be 0.025 mg/kg for SGOT and 0.25 mg/kg for SGPT. Furthermore, dose dependent myocardial necroses occured after norepinephrine treatment (lowest effective dose 0.025 mg/kg). Elevations in GLDH activity, retention of bromsulfalein, and light-optically detectable liver damage appeared only after doses of 1 mg/kg norepinephrine. However, 42% of the animals died after receiving this dose. The quotient SGOT/SGPT (De Ritis) which was 5.8±0.5 in the control rats decreased after administration of CCl4 or allyl alcohol, but was doubled or tripled in the norepinephrine experiments. This result, as well as the results of histo-pathologic evaluation, support the view that the serum transaminases liberated after the administration of norepinephrine originate from the heart. Therefore, an increase in serum transaminase activity alone is not sufficient evidence of liver damage. Norepinephrine in doses of 0.1 and 0.25 mg/kg did not augment the hepatotoxicity of CCl4 or allyl alcohol; all parameters indicated only additive effects. A dose of 1 mg/kg norepinephrine, however, potentiated some actions of these liver toxins (increase in serum transaminases after CCl4 or allyl alcohol; increase in GLDH and the severity of liver necroses after allyl alcohol). Thus, norepinephrine potentiates in rats the activity of hepatotoxic agents only at a dose which in itself leads to liver damage.
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  • 10
    ISSN: 1432-0738
    Keywords: Alcohol, Ethyl ; Injections, Intraperitoneal ; Hepatitis, Toxic ; Transaminases ; Glutamate Dehydrogenase ; Äthylalkohol ; Intraperitoneale Injektion ; Leberschädigung ; Transaminasen ; Glutamatdehydrogenase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Männliche Wistarratten erhielten einmalig 4,8 g/kg Äthanol entweder per Schlundsonde in Form einer 10, 20, 40 bzw. 60 %igen (v/v) Mischung mit Aqua dest. oder intraperitoneal in Form einer 10, 20 bzw. 30%igen (v/v) Mischung mit 0,9%iger NaCl-Lösung. 4, 8 und 16 Std später wurden die Serumaktivitäten der GOT, GPT und GLDH sowie der Blutalkoholspiegel bestimmt. Sowohl nach oraler wie intraperitonealer Applikation bestand eine negative Korrelation zwischen der Konzentration der zugeführten Alkohollösungen und der Höhe der Blutalkoholspiegel. Nach oraler Gabe von Äthanol kam es in 4 der 12 Versuchsgruppen zu leichten Aktivitätserhöhungen der Transaminasen, während die Aktivität der GLDH im Serum nicht beeinflußt wurde. Die intraperitoneale Injektion von 4,8 g/kg Äthanol führte demgegenüber zu wesentlich stärkeren Aktivitätserhöhungen der Serumtransaminasen sowie auch zu einem Anstieg der GLDH. Dieser Aktivitätsanstieg der Serumfermente war am stärksten nach der Injektion der 30 %igen, am geringsten nach der Injektion der 10 %igen Alkohollösung, obwohl die applizierte Gesamtdosis an Alkohol die gleiche war. Die Bromsulfaleinprobe wurde durch intraperitoneal injizierten Alkohol jedoch nicht beeinträchtigt. Nach intraperitonealer Injektion von Äthanol traten entzündliche Reaktionen des Peritoneums auf, deren Ausmaß von der Konzentration der Lösungen abhing. Histologisch waren ausgedehnte Nekrosen des Leberparenchyms nachzuweisen; diese fanden sich ausschließlich subkapsulär an der Oberfläche der Leber, während die tiefer gelegenen Parenchymschichten lichtoptisch normal waren. Die besonders starke hepatotoxische Wirkung des Alkohols bei intraperitonealer Applikation beruht auf einer unspezifischen lokalen Schädigung der Leber. Für Untersuchungen zur Frage der generalisierten spezifisch-hepatotoxischen Wirkung des Alkohols ist die intraperitoneale Injektion somit ungeeignet.
    Notes: Abstract Male rats received ethanol in a single dose of 4.8 g/kg either by stomach tube as a 10, 20, 40 or 60 % (v/v) solution in distilled water, or by intraperitoneal injection as a 10, 20, or 30% (v/v) solution in saline. 4, 8 and 16 h later we determined serum enzyme activities of GOT, GPT and GLDH and blood alcohol levels. There was a negative correlation between the concentration of the ethanol solutions administered orally or intraperitoneally and blood levels of ethanol. Oral application of ethanol led to slight increments of serum transaminase activities in 4 out of 12 groups, but did not influence the activity of serum GLDH. Intraperitoneal injection of 4.8 g/kg ethanol, on the other hand, produced strong increments of serum transaminase activities, as well as an increase of serum GLDH. This increase of serum enzyme activities was highest after injection of the 30 % solution and smallest after injection of the 10% solution, though the total dose of ethanol was the same. Bromsulfalein clearance, however, was not impaired after intraperitoneal injection of ethanol. Intraperitoneal injection of the ethanol solutions led to peritoneal inflammation, the severity of which corresponded to the concentration of ethanol. Furthermore, extensive necroses of the liver occurred in the surface area of the liver, whereas the parenchyma underneath was free from light-optically detectable damage. The severe hepatotoxic action of ethanol when injected intraperitoneally is due to an unspecific local injury. Intraperitoneal injection, therefore, is no suitable method for investigation of the generalized specific hepatotoxic activity of ethanol.
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