Differential scanning calorimetry of rat liver mitochondria

Summary Differential scanning calorimetry was employed for studying rat liver mitochondria and extracted mitochondrial lipids. Endothermic transition in the range 15–40°C was detected for the whole mitochondria and between 10–20°C for the extracted lipids.Acknowledgment. This work was supported in part by Volkswagen Foundation A.Z. 11-2711.     

Changes in red blood cell choline and choline-bound lipids with oral lithium

Summary The influence of oral lithium on the concentration of red blood cell choline (Ch), lecithin, glycerophosphorylcholine (GPCh) and phosphorylcholine (PCh) was studied. The concentration of RBC Ch was significantly elevated and the concentration of lecithin, GPCh and PCh significantly depressed in 16 patients on oral lithium compared to 9 age-matched controls. We conclude that lithium markedly depletes the red blood cell of choline containing compounds including lecithin. These changes may be responsible for both the therapeutic efficacy and the toxicity of lithium.     

Significant differential gene duplication without ancestral tetraploidy in a genus of mexican fish

Summary A comparison of the protein products of 20–25 structural gene loci among the known species of the goodeid fish genusSkiffia suggests that at least 4 loci (16–20%) have undergone species-specific duplications (or, in 1 case, apparent loss) during the evolution of the genus. The species are clearly diploids, and the data therefore indicate that even a large proportion of differentially duplicated loci within a group of related fish species is not critical evidence of common tetraploid ancestry. Differential duplication of structural gene loci may be an important component of the genetic differences that separate congeneric conventional diploid species.Supported by NSF grants DEB76-20958 (BJT), DEB77-03257 (EMR) and DEB77-17315 (RRM).     

Modified in vitro assay for melanocyte-stimulating hormone

Résumé L'activité de l'MSH dans du sérum de rat peut être mesurée maintenant grâce à une méthode nouvelle, très sensitive, de test biologique in vitro. Cette méthode a été modifiée de façon à réduire à un minimum acceptable des variations expérimentales.     

Changes in red blood cell choline and choline-bound lipids with oral lithium

The influence of oral lithium on the concentration of red blood cell choline (Ch), lecithin, glycerophosphorylcholine (GPCh) and phosphorylcholine (PCh) was studied. The concentration of RBC Ch was significantly elevated and the concentration of lecithin, GPCh and PCh significantly depressed in 16 patients on oral lithium compared to 9 age-matched controls. We conclude that lithium markedly depletes the red blood cell of choline containing compounds including lecithin. These changes may be responsible for both the therapeutic efficacy and the toxicity of lithium.     

The fate and effects ofSalmonella flagellin in neonatal rat intestine

Zusammenfassung Nachweis, dass intestinal appliziertes I¹²⁵ markiertesSalmonella Flagellin in Ratten, bis zum Alter von 5 Tagen, antigen wirkt. Die Aufnahme des Flagellins im Ileum erfolgt über vakuoläre Zellen der Mucosa.

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Supported by grants from the U.S.P.H.S., No. AI-08490, and John A. Hartford Foundation.     

The origin of mutants

Nucleic acids are replicated with conspicuous fidelity. Infrequently, however, they undergo changes in sequence, and this process of change (mutation) generates the variability that allows evolution. As the result of studies of bacterial variation, it is now widely believed that mutations arise continuously and without any consideration for their utility. In this paper, we briefly review the source of this idea and then describe some experiments suggesting that cells may have mechanisms for choosing which mutations will occur.