Hyperosmolar coma as etiological factor in the CNS radiation syndrome of rats

Summary Supralethal dose of whole-body or trunk but not head-irradiation in rats induced hyperosmolar coma accompanied by hypernatremia and hyperkalemia. This clinical entity has presented the symptoms of the CNS radiation syndrome with a characteristic short survival time.     

Hyperosmolar coma as etiological factor in the CNS radiation syndrome of rats.

Supralethal dose of whole-body or trunk but not head-irradiation in rats induced hyperosmolar coma accompanied by hypernatremia and hyperkalemia. This clinical entity has presented the symptoms of the CNS radiation syndrome with a characteristic short survival time.     

Pharmacogenetic factor in the convulsive responses of mice to flurothyl

Résumé La sensibilité convulsive a été determinée dans 6 groupes de souris par les réactions de l'ether hexafluorodiéthyle, convulsivant chimique. La lignée DBA/2 fut très sensible, tandis que les lignées C57BL/6 et BALB/c se montrèrent les moins sensibles. La sensibilité convulsive ne présenta pas de corrélation positive avec l'activité locomotrice.     

Morphological counterparts of the genetically determined resistance of mice to chloroform poisoning

Résumé L'intoxication au chloroforme des souris mâles C57BL/6JN, BN et de la génération F1 des souches C3H/He et C57BL/6JN entraîne une nécrose tubulaire rénale suivie par la régénération de l'épithélium tubulaire rénal. Tous les animaux survivent.     

Refeeding of mice after fasting stimulates cell renewal in the gall bladder epithelium

Summary The effect of refeeding of mice after a fasting period on the uptake of 3H-thymidine and on mitotic activity in the gall bladder epithelium was studied by histoautoradiography. A significant increase in both DNA synthesis and mitotic activity was observed after 12 h of refeeding.Acknowledgments. This work was supported by the Fonds voor Geneeskundig Wetenschappelijk Onderzoek and by the Algemeene Spar-en Lijfrentekas.     

Increase in the survival time of mice exposed to ionizing radiation by a new class of free radical scavengers

Summary N-acyl dehydroalanines react with and scavenge mainly superoxide radical and hydroxyl radical (HO^.). The ortho-methoxyphenylacetyl dehydroalanine derivative, indexed as AD-20, protects mice against damage resulting from total body X-irradiation, as measured by the increase in their survival time. AD-20 increases the LD₅₀ at 30 days from 6.1 to 7.3 Gy in animals exposed to a wide range of X-rays (6 to 10 Gy). The dose reduction factor (D R F) of AD-20 is 1.20. We postulate that such radioprotective effect may result from its free radical scavenging activity.     

Increase in the survival time of mice exposed to ionizing radiation by a new class of free radical scavengers

N-acyl dehydroalanines react with and scavenge mainly superoxide radical (O-2.) and hydroxyl radical (HO.). The ortho-methoxyphenylacetyl dehydroalanine derivative, indexed as AD-20, protects mice against damage resulting from total body X-irradiation, as measured by the increase in their survival time. AD-20 increases the LD50 at 30 days from 6.1 to 7.3 Gy in animals exposed to a wide range of X-rays (6 to 10 Gy). The dose reduction factor (D R F) of AD-20 is 1.20. We postulate that such radioprotective effect may result from its free radical scavenging activity.     

Soft versus hard water as a factor in the incidence of anencephalic foetuses in litters from trypan blue treated mice

Summary In an experiment designed to test the possible correlation between hard water and neural tube anomalies, high calcium intake was found to increase the number of exencephalic foetuses in litters from trypan blue treated mice. This is a reversal of the suggested trend in man where soft water and anencephaly may be correlated.     

Asymmetrical responses to directional selection for radiation resistance and sensitivity inDrosophila

Zusammenfassung Es wurde eine Selektion auf Strahlenresistenz nach Bestrahlung vonDrosophila melanogaster mit⁶⁰Co--Strahlen während 5 Generationen mit gutem Erfolg erzielt, nicht aber eine solche auf erhöhte Strahlensensibilität. Der asymmetrische Selektionseffekt dürfte somit auf dominanter Vererbung der Resistenz beruhen. Familienselektion kann auch ohne Besthralung zu resistenten Stämmen führen.     

Hyperlactacidemia as a factor of thrombocyte adhesiveness

Résumé Les auteurs, après avoir montré le rôle probable de l'hyperlactacidémie dans l'apparition du sludge, du blocage du SRE, de l'dème des cellules endothéliales des vaisseaux et de l'dème intraglial, montrent dans le présent travail sa responsabilité probable dans l'agrégation des plaquettes sanguines de l'homme et du rat, en dehors de toute influence de pH.     

Survival enhanced by skin-wound trauma in mice exposed to60Co radiation

Summary A 4%-body-surface skin wound given 24 h before exposure of mice to⁶⁰Co radiation raised the LD 50/30 from 825 to 975 rads, resulting in a dose reduction factor of 1.2. Enhanced survival of mice wounded before radiation was independent of extramedullary splenic myelocytopoiesis.Supported by the Armed Forces Radiobiology Research Institute, Defense Nuclear Agency, under research work unit 8324-60406. The views presented in this paper are those of the authors. No endorsement by the Defense Nuclear Agency has been given or should be inferred.Research was conducted according to the principles enunciated in the Guide for the Care and Use of Laboratory Animals prepared by the Institute of Laboratory Animal Research, National Research Council.