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Biomedical subjects

H B Bosmann

Publications and source records attributed to H B Bosmann.

At least 55 records · Page 3Linked to original sources
PubMed1979

Increased specific binding of [3H]diazepam in rat brain following chronic diazepam administration.

Male rats (175 g) were given 30 mg of diazepam in their food daily for 35 days. The animals became drowsy and ataxic from this high dose of drug. After the 35-day dosing, the rats were killed daily, and specific binding of [3H]diazepam and [3H]flunitrazepam was determined in synaptosomal preparations from these and corresponding control rats. On days 3, 4, 6, and 7 after the treatment period the specific binding and specific binding of [3H]diazepam was double that of the control binding and specific binding of [3H]flunitrazepam was 1.67 times that of control. The data indicate that very high doses of diazepam, given for long periods, cause increased specific binding of radiolabeled ligand to brain subfractions. The possible mechanisms and implications are discussed. When lower doses or shorter dosage regimens are used, increased binding is not observed.

Animals↗
PubMed1978

The inhibitory effect of heparin and warfarin treatments on the intravascular survival of B16 melanoma cells in syngeneic C57 mice.

Heparin and warfarin inhibit the intravascular survival of B16 melanoma cells in syngeneic C57B1/6J mice in a dose-related manner. The anticoagulant properties of these drugs appear to mediate their inhibitory effects on the survival of intravascular tumor cells. Despite the administration of large doses of heparin, a constant fraction of tumor cells survive to form lung tumors. These data indicate that coagulation dependent and coagulation independent populations of B16 cells normally survive following the intravenous injection of tumor cells.

Animals↗
PubMed1978

Quantitative relationship between volume of tumour cell units and their intravascular survival.

The derivation of the median volume (MV) and the geometric standard deviation (SDg) for a suspension of tumour cells quantifies the size and distribution of tumour cell aggregates in the suspension. Data collected in a group of 14 experiments shwoed a significant correlation of 0.80 (P less than 0.001) between the number of lung tumours formed by a suspension of B16 melanoma cells injected i.v. into C57BL/6J mice and the product of the MV and SDg of each cell suspension. These data define a size parameter of tumour cell suspensions that correlates with the intravascular survival properties of tumour cells.

Animals↗
PubMed1978

Competitive inhibition of benzodiazepine binding by fractions from porcine brain.

Fractions of porcine cerebral cortex extract separated by molecular weight on a Sephadex G-75 column were tested for their activities and potencies to inhibit [3H]benzodiazepine binding to rat brain homogenates. The fractions spanned molecular weights from 500 to 100,000. A potent inhibitor (benzodiazepine-competitive factor I, BCF-I) was discovered in the fraction containing substances with molecular weights from 40,000 to 70,000. Equilibrium binding studies indicated that BCF-I was a competitive inhibitor, making it a candidate as a benzodiazepine endogenous factor or profactor. BCF-I was heat stable, but trypsin digestion destroyed its activity. Another inhibitory fraction (BCF-II) was 1/5th as active as BCF-I and contained substances with molecular weights from 1000 to 2000.

Animals↗
PubMed1978

Biochemical, morphologic and physiologic changes in the adrenal glands of rats chronically treated with phenobarbital.

Biochemical and ultrastructural changes in the adrenal glands of rats were observed after long-term phenobarbital treatment. At the fine structural level, the parenchymal cells of the phenobarbital-treated rats resembled cortical cells that had been stimulated by adrenocorticotropin. A significant finding was the presence of very large hollow mitochondria characterized by loss of vesicles and cristae with retention of the double outer membrane. Arylesterase (EC 3.1.1.2) activity, the marker used for rough endoplasmic reticulum, was significantly diminished. Since rough endoplasmic reticulum is present primarily in the adrenal medulla and not the cortex, the relative decrease in arylesterase activity is consistent with the morphologic adrenal cortical hyperplasia. Trypsin-like (EC 3.4.4.4) enzyme activity was increased. The plasma corticosterone response to adrenocorticotropin injection was not significantly different in treated and control rats. The similarity of the observed mitochondrial changes to the reported mitochondrial cavitation in the adrenal glands of rats treated with aminoglutethimide is discussed.

Adrenal Glands↗
PubMed1977

Glycosyltrasferase activity in developing sea-urchin embryos.

The developmental course of activity changes of 4 endogenous membrane glycosyltransferases: UDP-glucose : glycosyltrasferase, UDP-galactose : glycosyltransferase, GDP-mannose: glycosyltransferase, and UD-PN-acetylglucosamine : glycosyltransferase was determined in various stages of developing sea-urchin embryos from unfertilized eggs up to the 16-cell stage. The results show that there is a 2-fold increase in glycosyltransferase activity after fertilization. These results are discussed in relation to the postulated role of glycosyltransferases in mediating adhesion, recognition, and agglutination of cells and embryos.

Animals↗