Physiological state of submitochondrial particles and their susceptibility to Triton X-100

Summary The solubilizing effect of Triton X-100 on beef heart submitochondrial particles (ETP_H) has been studied under various physiological conditions. Coupled, uncoupled and azide-inhibited ETP_H particles have been studied. Quantitative and qualitative differences are found in the proteins solubilized by the detergent from ETP_H particles under the various conditions tested.Acknowledgments: This work was supported in part by a grant from a Spanish Comisión Asesora para la Investigación Cientifica y Técnica. M.C. Barbero was recipient of a scholarship from the Basque Government.     

Isoelectric focusing of mosquito esterases in the presence of Triton X-100

Summary Triton X-100 improves nonspecific esterase solubilization from mosquito samples and also leads to increased resolution in an isoelectric focusing electrophoresis.Acknowledgments. This research was supported by a US Army contract/grant DAMD 17-77-C-7018, US Army Medical Research and Development Command, Washington, DC and by the Office of Naval Research.     

A disc-electrophoresis investigation of certain characteristics of Triton X-100 solubilized proteins from malePeriplaneta americana

Resumen Un agregado de proteínas solubilizadas en Triton X-100 fue resuelto como una banda por electroforesis a un pH de 8.5. En un pH de 7.1 estas fracciones no demuestran el efecto de agregación. Solamente electroforesis conTris/glicina como amortiguador y concentraciones del detergente menor de 0.6% dieron resultados.     

Cytoplasmic contaminants in Triton X-100 washed rat liver nuclei - a possible way of further purification.

The presence of cytoplasmic contaminants is demonstrated in preparations of rat liver nuclei, even after washing with Triton X-100. They can be removed by incubation at 37 degrees C in a medium of low-salt concentration.     

Direct electric measurement of the functioning of adenosine triphosphatase of submitochondrial particles of beef heart]

A direct potential measurement of the activity of bound ATPase has been achieved with beef heart submitochondrial particles adhering to a thick phospholipidic membrane. Electric signals (90 mV amplitude) were found to be fully sensitive to ATPase inhibitors and uncouplers.     

Are some interactions between NADH oxidase and succinate oxidase in beef heart non-phosphorylating submitochondrial particles artifacts?

Summary Critical review of literature and experiments by the authors are suggestive that some interactions between mitochondrial respiratory complexes could be due to a minimal matrix enzymes contamination.Acknowledgments. The authors are grateful to Dr Wanda De Luca for technical assistance.     

Correlation between the susceptibility of E. coli to phagocytosis and their ability to invade HeLa cells in vitro

Summary The susceptibility of several strains of E. coli to phagocytic killing by polymorphonuclear leucocytes and the ability of the same strains to invade HeLa cells were studied. It was found that only the strains resistant to killing by leucocytes were able to penetrate and multiply within HeLa cells.Acknowledgments. We thank Dr Bianca Pani who supplied us with HeLa cells. Supported by grant No. 75.00695.04 from the National Research Council of Italy (CNR).     

Measurement of phosphatase activity in the cell wall obtained with the help of a nonionic detergent (Triton X 100)

The phosphatase activity of cell walls isolated by treating the intact roots with Triton X 100 is very steady. It is similar to that of living roots and that of cell walls isolated by centrifugation after the grinding of the tissues.     

Correlation between the susceptibility of E. coli to phagocytosis and their ability to invade HeLa cells in vitro.

The susceptibility of several strains of E. coli to phagocytic killing by polymorphonuclear lencocytes and the ability of the same strains to invade HeLa cells were studied. It was found that only the strains resistant to killing by leucocytes were able to penetrate and multiply within HeLa cells.     

Sex difference in susceptibility of mice to pneumococcus

Résumé L'injection deDiplococcus pneumoniae (type 12) par voie intrapéritonéale à des souris albinos provoque un taux de mortalité significativement plus élevé chez les mâles que chez les femelles. Ce fait pourrait servir de modèle à l'étude des différences sexuelles dans la résistance à l'infection.     

Circadian fluctuation of susceptibility to haloperidol under constant conditions

An endogenous circadian rhythm of the sedative and antiapomorphine effects of haloperidol was observed under constant conditions for 7 days as well as under an entrained light-dark cycle.     

Increased susceptibility of riboflavin deficient rats to galactose cataract

Zusammenfassung Bei riboflavinarm ernährten Albinoratten beträgt die Aktivität der Erythrocyten-Glutathionreduktase nur 40% und diejenige der Augenlinsen-Glutathionreduktase 75% der Aktivität normaler Kontrolltiere und es kommt zu vorzeitigem Auftreten von Katarakten.     

Circadian fluctuation of susceptibility to haloperidol under constant conditions

Summary An endogenous circadian rhythm of the sedative and antiapomorphine effects of haloperidol was observed under constant conditions for 7 days as well as under an entrained light-dark cycle.     

Chromosome fragility and susceptibility of Bloom's syndrome fibroblasts to SV40 transformation

Summary A comparison of the frequencies of chromosomal aberrations and the rates of SV40 transformation was made using fibroblasts obtained from 2 patients with Bloom's syndrome (BS) and from a normal individual. BS cells were found to be more susceptible to chromosome damage, in confirmation of earlier reports, but surprisingly, BS cells were distinctly less prone to transformation.Supported in part by the Michael J. Connell Foundation Medical Genetics Fund, and Health, Education and Welfare, MCH project 422.     

Chromosome fragility and susceptibility of Bloom's syndrome fibroblasts to SV40 transformation

A comparison of the frequencies of chromosomal aberrations and the rates of SV40 transformation was made using fibroblasts obtained from 2 patients with Bloom's syndrome (BS) and from a normal individual. BS cells were found to be more susceptible to chromosome damage, in confirmation of earlier reports, but surprisingly, BS cells were distinctly less prone to transformation.     

Physiological and nutritional importance of selenium

Summary The essential trace element selenium has recently attracted attention because of its potentialities in the maintenance of human health. Selenium forms part of the active site of the peroxide-destroying enzyme glutathione peroxidase, and it also has other functions, for example in biotransformation, detoxification and the immune response. Functional and clinical consequences of selenium deficiency states have been described, and the selenium requirement, which is influenced by the usual selenium exposure, has been discussed. Wide variations have been found in selenium status in different parts of the world, and populations or groups of patients exposed to marginal deficiency are more numerous than was previously thought.Current research activities in the field of human medicine and nutrition are devoted to the possibilities of using selenium for the prevention or treatment of degenerative or free radical diseases such as neurological disorders, inflammatory diseases or cancer. Pharmacological selenium doses are also recommended as an adjuvant in some treatments.