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Biomedical subjects

R Plass

Publications and source records attributed to R Plass.

At least 37 records · Page 2Linked to original sources

[The effect of ethylenethiurea on hematopoesis in rats].

The influence of single and repeated oral administration of ethylenethiourea (ETU) on hematologic parameters of the peripheral blood and the bone marrow was studied in male and female rats. Effects of single treatment on the erythrocytic system were initially indicated by increase in red blood cell count, hemoglobin concentration and hematocrit of the peripheral blood. The initial polyglobulia was followed by a decrease in the blood hemoglobin concentration and the number of erythroblasts of the bone marrow. Continuous administration of ETU resulted in hyporegenerative anemia. The white blood picture showed leukopenia after single and continuous administration of the substance. This effect resulted from a decline in lymphocyte numbers which occurred both in the peripheral blood and in the bone marrow. The hematologic changes were induced with 50 mg ETU/kg body weight and more using single treatment and 600 ppm (= 70 mg ETU/kg body weight) and more under dietary administration.

Animals↗

Short-term toxicity study of allyl isothiocyanate in rats.

Allyl isothiocyanate (AITC) was given in doses of 0, 10, 20, or 40 mg/kg (5 days/week) by oral intubation to male rats for up to 6 weeks. The highest dosage level caused a decrease in body weight, thymus weight, blood glucose and serum globulin levels. Haematological examination revealed an increased percentage of neutrophils and a decreased percentage of lymphocytes after treatment for 2 weeks. Increased liver and adrenal weights were found in all test groups. Renal dysfunction was indicated by increased urinary aspartate amino-transferase activity, reduced urine volume and changes in the specific gravity of the urine. Histopathological changes were observed in the kidneys of animals at dosages of 20 and 40 mg/kg and in the livers of animals at the highest dosage level.

Animals↗

[The effect of azoxybenzene on microsomal liver enzymes in the rat].

Oral administrations of azoxybenzene (0, 25, 50 and 100 mg/kg b.w.) over a period up to 7 days caused a time and dose dependent decrease in the amount of cytochrome P-450 as well as in the ability of aminopyrine-N-demethylation and aniline hydroxylation in the hepatic microsomes of male and female rats. In both sexes there were retardations in the body weight gain and increases in the relative weight of the liver. The amount of the microsomal cytochrome b5 was increased.

Aminopyrine N-Demethylase↗

Activation of leukocytes during prolonged physical exercise.

Previous studies have demonstrated an increment of circulating leukocytes and enhanced secretion of interleukin-1 by monocytes and macrophages during physical exercise. In the present study the effect of physical exertion on the activity of polymorphonuclear (PMN) leukocytes was investigated. Following both short-term (running 2,000 meters) and long-term (running 10,000 meters) exertion, phorbol-stimulated chemiluminescence, as an indicator of leukocytic oxygen radical formation and release of leukocytic elastase, as a parameter of degranulation, were determined immediately after running. The number of circulating leukocytes increased both after short-term (+21%) and long-term (+61%) exercise. There was a minor release of PMN elastase following short-term activity causing plasma levels of this compound to rise from 100 +/- 4.0 ng/ml to 116 +/- 12.3 ng/ml. Long-term exercise, on the other hand, induced a significant increase of elastase plasma levels from 107 +/- 9.1 ng/ml to 300 +/- 23.4 ng/ml, suggesting a remarkable release of this proteinase from neutrophils. Based on these findings we conclude that during physical exercise degranulation of PMN leukocytes occurs. Moreover, the fact that phorbol-stimulated chemiluminescence is decreased after running demonstrates an impaired capability of white cells to generate oxygen radicals.

Adult↗

Effect of allyl isothiocyanate on hepatic monooxygenases and serum transferases in rats.

The effect of allyl isothiocyanate (AITC) on the activities of liver monooxygenases and serum transferases was investigated in male rats. AITC was given in oral doses of 0, 50, 100 or 150 mg/kg bw for 3 consecutive days. Increased relative liver weights and decreased activities of hepatic aminopyrine-N-demethylase, p-nitroanisole-O-demethylase and aniline-p-hydroxylase were observed in all treatment groups. The administration of AITC at dose levels of 100 and 150 mg/kg caused a statistically significant increase in the serum aspartate aminotransferase activity.

Alanine Transaminase↗

[Comparison of the distribution and toxicity of alpha-, beta-, and gamma-hexachlorocyclohexane (HCH) following 30 days of administration to rats].

Administration of 1000 ppm alpha-HCH, 600 ppm beta-HCH and greater than or equal to 125 ppm gamma-HCH to rats caused a growth retardation. alpha-HCH and beta-HCH led to livermass enlargement. beta-HCH caused a decrease of absolute brain-mass. In case of alpha-HCH and gamma-HCH fat tissue, kidneys and adrenals had a high burden in residues. Fat tissue and adrenals had high residues of beta-HCH. The level of HCH-residues during the test period was gamma much less than beta less than alpha. The results are discussed taking into account the contradictory knowledge from literature.

Animals↗

Transluminal closure of patent ductus arteriosus: long-term results of 208 cases treated without thoracotomy.

Patent ductus arteriosus was the first inborn cardiac defect ever eliminated by percutaneous transvascular therapy. The method, results, and complications of Ivalon plugging of the ductus in 208 patients between 5 and 62 years old and treated between 1967 and 1985 are described. Permanent closure was accomplished in 197 patients (94.7%). The following particular benefits are obtainable from the method: no need for thoracotomy; local anesthesia applicable to 65% of all cases; 30 mm average time of intervention; only moderate invasiveness to the patients; only 7 days of hospitalization; good cost-benefit ratio.

Adolescent↗

[The enzymatic degradation of DDT. 3. Metabolism of DDT].

DDT orally given to rats is converted into DDD by reductive dechlorination in the liver within 30 min. 6 h after a single application of 10 mg DDT per rat a quantity of 60 mg DDD/kg was indicated in the liver. DDT is stored in the adrenal glands; in the other organs an equilibrium comes up obviously, even with further application. The quantitative ratios are reported. Information on the experimental details of DDT determination and--anticipatory to the following publications--on the analysis of the most relevant metabolites is given.

Animals↗

[The influence of lindane and lindane metabolites on microsomal and mitochondrial ATPase in vitro].

In vitro investigations of the influence of lindane and its metabolites were performed on microsomal and mitochondrial ATPases from liver, kidney and brain of rat and mouse. The microsomal Na+-K+-ATPases in rat liver were inhibited by the tested substances. An increase of activity was observed only with 2.5 X 10(-5) M gamma-HCH. Effects on the microsomal Na+-K+-ATPase from kidney and brain of rat were also indicated. The mitochondrial enzyme in rat liver was stimulated by all the compounds tested at concentrations of 10(-4) M - 10(-2) M. The effects on mitochondrial enzymes from kidney and brain varied in dependence on the tested substances. In the microsomes and mitochondria of mouse an influence on the Na+-K+-ATPases similar to the effects on the preparations from organs of rat was evident.

Animals↗