Ionized calcium in the effluent from ventriculo-cisternal perfusion in the rabbit

Zusammenfassung Es wird am Kaninchen gezeigt, dass die Konzentration ionisierten Kalziums im Ausfluss eines ventriculo-cisternalen Perfusionssystems nur wenig von der Plasmakonzentration beeinflusst ist. pH-Erniedrigung im Blut erhöhte die Konzentration erheblich.     

Haemopoietic stem cell concentration and CFUs in DNA synthesis in bone marrow from different bone regions

Summary The concentration of colony-forming cells (CFUs) is about 40% less in sternal marrow than in the marrow of lumbar vertebrae and femora. Marrow of trabecular bones in lumbar vertebrae contains fewer mitotically active CFUs than marrow of trabecular bones in the femoral distal epiphysis and metaphysis, or the peripheral marrow near the cortical bone in the femoral diaphysis. Only a minor part of the variability of the results in the CFU-assay is due to differences in CFU-concentrations between individual donor mice; pooling of the cell suspensions does not substantially decrease variability. Specific pathogen-free mice yield the same results as BALB/c mice from conventional breeding.Acknowledgments. This work was performed with support of Euratom contract No. 233-771 BIO B. We thank L. Tessens for his excellent technical assistance.     

Lipoperoxidation rates and drug-oxidizing enzyme activities in the liver and placenta of some mammal species during the perinatal period

Summary Lipoperoxidation and drug-metabolizing enzymes were measured in livers and placentas of different mammal species during the perinatal period. In placentas and fetal livers of rat, rabbit and guinea-pig, cofactor-supported lipoperoxidation was negligible, as were the activities of drug-oxidizing enzymes. Human fetal liver contained an intact drug-oxidizing electron transport chain, and lipoperoxidation activity was accordingly observed. It is suggested that lesions mediated by lipoperoxidation may be possible in human fetus, but they are less probable in animal fetuses.The skillful technical assistance of Ms.Liisa Tuhkanen and Ms.Vuokko Väisänen is gratefully acknowledged.     

The effect on the onset of puberty of whole body irradiation of infant female rats with and without hypothalamic lesions

Résumé Les résultats obtenus suggèrent que la lésion de l'hypothalame provoquée par la microcoagulation accélère l'apparition de la puberté des rats totalement irradiés aux rayons X, ce qui est le cas aussi chez des rats normaux. Mais l'apparition de la puberté est retardée proportionnellement aux doses de rayons X appliquées, indépendamment de la microcoagulation.