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Biomedical subjects

J Bauer

Publications and source records attributed to J Bauer.

At least 631 records · Page 35Linked to original sources
PubMed1978

The role of vanadium in green plants. IV. Influence on the formation of delta-aminolevulinic acid in Chlorella.

In a series of experiments, it is demonstrated that the trace element vanadium (4.10(-7) g-at/1 as NH4VO3) has a considerable positive influence on the synthesis of delta-aminolevulinic acid(delta-ALA) in the autotrophically growing green alga Chlorella pyrenoidosa, the effect being visible by an enhanced output of the amino acid into the culture medium in presence of levulinic acid (LA). The level of intracellularly accumulated delta-ALA, however, is not changed in presence of the metal. The V-effect on exogenous found delta-ALA is suppressed, when LA is added to the nutrient medium at low pH (pH5), although V-uptake into the algal cells is not disturbed by LA. As demonstrated in culture media with various nitrogen sources (urea, partially hydrolized urea, ammonium salts), the development of the pH during the cultivation time is important for the presentation of the V-effect on delta-ALA. It is suggested that vanadium acts as a catalyst in the conversion of 4,5-dioxovaleric acid to delta-ALA by transamination.

Aminolevulinic Acid↗
PubMed1978

The effect of pregnancy on the metabolism of [14C]phenytoin in the isolated perfused rat liver.

The metabolism of [14C]phenytoin (DPH) was measured in isolated perfused livers from non-pregnant female rats and rats at 13, 15, 17, 19 and 21 days of gestation. The half-life of [14C]phenytoin in the perfusate was not significantly altered by pregnancy in livers perfused with 20% blood at 2 ml/min/g of liver but was increased from 38 min in control livers to 158 min in livers from rats at 21 days of gestation when livers were perfused with 10% blood at 1 ml/min/g of liver. Secretion of the glucuronide conjugate of 5-[14C]phenyl-5-parahydroxy-phenylhydantoin into the bile was markedly inhibited during the latter stages of pregnancy such that a 4-fold decrease in the cumulative secretion into the bile was present at 21 days of gestation. The bile/perfusate concentration ratio of the glucuronide after 30 min was 148 in control livers but decreased to 6 in livers from rats at 21 days gestation.

Animals↗
PubMed1977

Prostaglandin influence on pulmonary intravascular leukocytic aggregation during cardiopulmonary bypass.

A variety of pharmacologic agents have been infused during cardiopulmonary bypass in an attempt to prevent intravascular leukocytic aggregation in the lung. To date corticosteroids have been advocated because of their ability to stabilize lysosomes. We have studied two additional agents, prostaglandin E1 (PGE1) and dipyramidole (DIPYR) and compared their effects with those of methylprednisolone sodium succinate (MPSS) and a control group. The drugs were infused into the dog during perfusion and lung biopsies obtained before, during, and at the end of 2 hours of cardiopulmonary bypass using whole blood prime of the Bentley bubble oxygenator. The biopsies were interpreted by a pathologist who was unaware of the modality of treatment. Our results indicate that PGE1 provides more protection from intravascular pulmonary leukocytic aggregation than DIPYR and MPSS.

Animals↗
PubMed1977

The metabolism of d-, l- and dl-methadone in the isolated perfused rat liver.

Five-milligram doses of d-, l- and dl-methadone were added to the perfusate of the isolated perfused rat liver and the disposition of each compound was monitored over a period of 120 minutes. There was an initial rapid decline in concentration of each drug in the perfusate, with approximately 70% disappearing in the first 10 minutes of the perfusion. Thereafter, the rate of decline of each compound slowed and the apparent half-life was about 100 minutes. In experiments with d- l- and dl-methadone the mean hepatic extraction from the perfusate at 10 minutes was 72, 66 and 69%, respectively. A comparison of the rate of disappearance of the d- and the l-isomers from the perfusate showed that the concentration of the d-isomer at each sampling time was lower than the concentration of the l-isomer and this concentration ratio ranged between 68 and 79%. A study of the disposition of dl-methadone in the isolated perfused liver indicated that the initial rapid decline of the drug in the perfusate in the first 10 minutes was caused primarily by the uptake of the unchanged drug into the liver. Thereafter, the concentration of methadone in the perfusate and liver declined slowly with time and was paralleled by an increase in the concentration of the primary mono-N-demethylated metabolite, which appeared in the liver, perfusate and bile. Smaller quantities of more polar metabolites, including hydroxylated compounds and conjugates, were also present in the liver and bile. Addition of SKF 525-A retarded the rate of decline of methadone from the perfusate and pretreatment of the rat with phenobarbital increased the rate of biotransformation of methadone in the isolated perfused liver.

Animals↗
PubMed1977

Bilateral optic canal meningioma.

A case of bilateral optic canal meningiomas which presented with progressive visual deterioration and optic atrophy is described. Complete neurologic investigation was negative, only surgical exploration disclosed the tumors.

Adult↗