Antidepressant drugs can slow or dissociate circadian rhythms

Summary The circadian rest-activity cycle of female hamsters was lengthened by chronic administration of the monoamineoxidase inhibitor antidepressant drug clorgyline. Chronic treatment with clorgyline or the tricyclic antidepressant drug imipramine also induced dissociation of circadian activity rhythm components. Thus these drugs may be added to the very small group of substances (including the prophylactic antidepressant and antimanic drug lithium) that modify circadian frequency and/or coupling between circadian rhythms.A preliminary analysis of these results was presented at the 18th Annual Meeting of the American College of Neuropsychopharmacology, Puerto Rico 1979²⁸.Neuropharmacology Branch, National Institute of Mental Health.     

Deficiency of the 50K dystrophin-associated glycoprotein in severe childhood autosomal recessive muscular dystrophy.

X-linked recessive Duchenne muscular dystrophy (DMD) is caused by the absence of dystrophin, a membrane cytoskeletal protein. Dystrophin is associated with a large oligomeric complex of sarcolemmal glycoprotein. The dystrophin-glycoprotein complex has been proposed to span the sarcolemma to provide a link between the subsarcolemmal cytoskeleton and the extracellular matrix component, laminin. In DMD, the absence of dystrophin leads to a large reduction in all of the dystrophin-associated protein. We have investigated the possibility that a deficiency of a dystrophin-associated protein could be the cause of severe childhood autosomal recessive muscular dystrophy (SCARMD) with a DMD-like phenotype. Here we report the specific deficiency of the 50K dystrophin-associated glycoprotein (M(r) 50,000) in sarcolemma of SCARMD patients. Therefore, the loss of this glycoprotein is a common denominator of the pathological process leading to muscle cell necrosis in two forms of muscular dystrophy, DMD and SCARMD.     

Photosensitization and feeding deterrence ofEuxoa messoria (Lepidoptera: Noctuiidae) by α-terthienyl,a naturally occurring thiophene from the Asteraceae

Summary Alpha-terthienyl, a phototoxic thiophene derivative from species in the Asteraceae reduced feeding and growth of the phytophagous lepidopteran,Euxoa messoria, when incorporated into artificial diets at a concentration of 100 ppm. The effects of this substance were substantially enhanced by including photosensitizing near-UV radiation in the trials. The results suggest that the phototoxic properties of this secondary substance provide significant protection to the plants containing it.This work was supported by NSERC and Agriculture Canada.     

Thein vivo effect of some peroxides upon the mouse ascites carcinoma of ehrlich

Zusammenfassung Die Lebensdauer von mit Ehrlich-Ascites-Karzinom injizierten Mäusen wird durch Wasserstoffsuperoxyd und Harnstoffperoxyd auffallend verlängert. Der Tumor wird dabei von der Ascites- in die solide Form umgewandelt.

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This work was supported by a grant from the United States Public Health Service (C-3538).     

Association of dystrophin and an integral membrane glycoprotein

Duchenne muscular dystrophy (DMD) is caused by a defective gene found on the X-chromosome. Dystrophin is encoded by the DMD gene and represents about 0.002% of total muscle protein. Immunochemical studies have shown that dystrophin is localized to the sarcolemma in normal muscle but is absent in muscle from DMD patients. Many features of the predicted primary structure of dystrophin are shared with membrane cytoskeletal proteins, but the precise function of dystrophin in muscle is unknown. Here we report the first isolation of dystrophin from digitonin-solubilized skeletal muscle membranes using wheat germ agglutinin (WGA)-Sepharose. We find that dystrophin is not a glycoprotein but binds to WGA-Sepharose because of its tight association with a WGA-binding glycoprotein. The association of dystrophin with this glycoprotein is disrupted by agents that dissociate cytoskeletal proteins from membranes. We conclude that dystrophin is linked to an integral membrane glycoprotein in the sarcolemma. Our results indicate that the function of dystrophin could be to link this glycoprotein to the underlying cytoskeleton and thus help either to preserve membrane stability or to keep the glycoprotein non-uniformly distributed in the sarcolemma.