The physical state of alkali ions in a Halobacterium: Some NMR results

Summary Nuclear magnetic relaxation measurements of the ions Na⁺, Rb⁺ and Cs⁺ in a Halobacterium sp. are described. The results support a theoretical model which involves the binding of intracellular alkali ions.We wish to thank the European Molecular Biology Organization (EMBO) and the Nederlandse Stichting voor Zuiver Wetenschappelijk Onderzoek (ZWO) for the financial support that made our stay in Groningen possible.     

Estrogens in 2-chloroethylphosphonic acid induced femaleness ofCucurbita pepo L.

Résumé L'acide 2-chloroéthylphosphonique (un substitut de l'éthylène) augmente la féminité deCucurbita pepo L. On observe en même temps une augmentation des strogènes endogènes. Il est possible que ces derniers participent à la différenciation du sexe chez les plantes.

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Acknowledgments: We are grateful to Amchem Products, Inc., Ambler (Pa., USA) for a gift sample of 2-chloroethylphosphonic acid (Ethrel formulation 68–250).     

Some effects of radiation on the free amino acids of adult female Mediterranean fruit fly,Ceratitis capitata Wied

Summary Ceratitis capitata pupae, 2–3 days before adult emergence, were treated with gamma irradiation from a⁶⁰Co source. The female fruit flies were extracted and analyzed for free amino acids.     

On the binding of steroid sulfates to albumin

3H-Labeled steroid sulfates, sulfate of estrone (E1S) or dehydroepiandrosterone (DHAS), were dialyzed against delipidated human serum albumin or human plasma in the presence of increasing amounts of competing non-labeled sulfates (DHAS or E1S). The apparent equilibrium constants (K) of the tracers did not measurably change at concentrations of the non-radioactive sulfates below 10(-5) mol/l. At higher concentrations, K decreased gradually. The apparent equilibrium constant of 3H-E1S was diminished by plasma in a similar fashion. It may be concluded that albumin possesses one strong, non-specific binding site. This site, however, does not seem to be utilized for the binding of E1S in vivo, because of its preferential occupation by other ligands. This may be true for other steroid sulfates as well, depending on their relative abundance in plasma.     

The ultrastructure of thiosomes of the mouse brain

Zusammenfassung Nachweis, dass die chromhämatoxylinen, Gomori-positiven Granula in periventrikulären Gliazellen des Säugetiergehirns grosse Organellen mit hohem Schwefelgehalt (Thiosomen) und charakteristischer lamellärer Binnenstruktur darstellen.

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Acknowledgments. I thank Mr.J. Godula, M. Sc., for excellent technical asistance.     

Mechanism of urea nitrogen binding by proposed oxidized starch gastrointestinal absorbents.

By use of 14-C label it was demonstrated that apparent binding of urea N to polyaldehyde starch was probably preceeded by hydrolysis to ammonium ion. Thus direct urea binding was not the mechanism through which ingested polyaldehyde starch might increase fecal N excretion in uremic patients.