Preoptic BRS3 neurons increase body temperature and heart rate via multiple pathways

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Developmental Changes in the in Vitro Activated Regenerative Activity of Primitive Mammary Epithelial Cells

Many normal adult tissues contain rare stem cells with extensive self-maintaining regenerative potential. During development, the stem cells of the hematopoietic and neural systems undergo intrinsically specified changes in their self-renewal potential. In the mouse, mammary stem cells with transplantable regenerative activity are first detectable a few days before birth. They share some phenotypic properties with their adult counterparts but are enriched in a subpopulation that displays a distinct gene expression profile. Here we show that fetal mammary epithelial cells have a greater direct and inducible growth potential than their adult counterparts. The latter feature is revealed in a novel culture system that enables large numbers of in vitro clonogenic progenitors as well as mammary stem cells with serially transplantable activity to be produced within 7 days from single fetal or adult input cells. We further show that these responses are highly dependent on novel factors produced by fibroblasts. These findings provide new avenues for elucidating mechanisms that regulate normal mammary epithelial stem cell properties at the single-cell level, how these change during development, and how their perturbation may contribute to transformation.     

Blocking NMDA receptors prevents the oxidative stress induced by acute ammonia intoxication

Acute ammonia intoxication diminishes the activities of antioxidant enzymes and increases superoxide formation in brain. These effects could play a role in the mechanism of ammonia toxicity. It has been shown that ammonia toxicity is mediated by activation of NMDA receptors. The aim of this work was to assess whether ammonia-induced changes in antioxidant enzymes and in superoxide formation are mediated by activation of NMDA receptors. It is shown that MK-801, an antagonist of NMDA receptors prevents ammonia-induced changes in superoxide dismutase, glutathione peroxidase and catalase. Ammonia intoxication also induces a depletion of glutathione and an increase in lipid peroxidation. Both effects, as well as ammonia-induced increase in superoxide formation are prevented by MK-801. These results indicate that ammonia-induced oxidative stress in brain is mediated by excessive activation of NMDA receptors and support the idea that oxidative stress can play a role in the mechanism of ammonia toxicity.     

Absence of chromosomal damage in human lymphocytes exposed to microwave radiation with hyperthermia

Specimens of human blood were exposed to 0, 4, 40, 100, and 200 Wkg-1 of 2.45 GHz microwave radiation for 20 minutes. The blood temperature was carefully controlled so that it rose from 37 to 40 degrees C. Cultured lymphocytes were examined for induced chromosomal damage but no effect in excess of background was observed.     

A hyperefficient process for enzymatic cellulose hydrolysis in the intensive mass transfer reactor

Summary A new type of bioreactor, the intensive mass transfer reactor (IMTR), has been developed for enzymatic hydrolysis of cellulose. Using T. reesei cellulases (2 FPU/ml), 3.5–6% of sugars were obtained in the IMTR after 0.5–2 h of cellulose hydrolysis with a productivity of 30–73 g/l.h.     

C9orf72 deficiency promotes microglial-mediated synaptic loss in aging and amyloid accumulation

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