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Biomedical subjects

R E Hauser

Publications and source records attributed to R E Hauser.

15 recordsLinked to original sources
PubMed1985

Osteomas in OF-1 mice: no alteration in biologic behavior during long-term treatment with cyclosporine.

During the course of a long-term oral study in OF-1 mice for the assessment of any carcinogenic potential of the immunosuppressive agent cyclosporine (CS-A), a high incidence of osteomas was found in all treatment groups as well as in controls. The incidences of osteoma-bearing mice were 20% in control male and 30% in control female mice; the respective incidences in all treated mice were 14.7% for males and 38% for females. The osteomas were found to occur in multiple sites in 70% of control males, in 73.3% of control females, and from all treated groups in 54.5% of males and 64.9% of females. The pelvis and sacrum were most frequently involved (42%), followed by the hindlimbs (32%), the skull (14.5%), the vertebral column (6.5%), the forelimbs (4%), and the sternum and ribs (1%) in control animals. The distribution of osteomas was similar in treated mice and did not differ significantly from controls. Histologic and ultrastructural analysis confirmed benign osteomas with abundant C-type viral particles. Thus a previously unobserved spontaneous high incidence of osteomas was reported in OF-1 mice. Immunosuppressive treatment with CS-A did not change the incidence or the biologic behavior of these osteomas.

Animals↗
PubMed1980

Correlations between chanelled Na+ entry, Ca2 + fluxes and insulin release in pancreatic beta-cells.

The results of ion flux measurements and insulin release studies performed on isolated rat islets of Langerhans using veratridine and tetrodotoxin show that Na+ channels exist in the outer membrane of pancreatic beta-cells. From a pharmacological point of view these channels appear very similar, if not identical, to those present in nerve. The consequences of opening such channels are described and their possible involvement in the physiological regulation of insulin release discussed.

Animals↗
PubMedDate not supplied

Effects of cyproheptadine on the rat yolk sac membrane and embryonic development in vitro.

Electron-microscopic examinations of rat embryonic yolk sacs treated in vitro with 1.5 X 10(-5) M cyproheptadine showed proliferation of the lysosomal structures; other organelles remained unaffected, and also overall yolk-sac growth and vascularization were comparable to non-treated samples. Radioactive measurements with 125I-labelled albumin showed that yolk sacs and embryos of the cyproheptadine-treated group incorporated less radioactivity than the controls. Embryos inside the yolk sacs, treated either for 24 or 48 h, were severely retarded in growth and differentiation (approximately 50% of the controls). It is suggested that the specific action of cyproheptadine on yolk-sac lysosomal structures, combined with reduced macromolecular transport, is the cause of inhibited embryonic development.

Animals↗