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Transepithelial electrical resistance measurements on Madrin-Darby canine kidney epithelial cells reveal that physiological heat stress results in a reversible increase in paracellular heat conductance, which is independent of cell numbers. Conditioning heat stress attenuates temperature-induced epithelial permeability and results in increased levels of inducible heat-shock proteins (HSP). Elevated cellular HSP70 helps restore impaired microfilaments and cytoskeletal proteins. Heat-induced cellular changes in intracellular calcium diglyceride and oxidant levels and microfilament changes increase permeability across the epithelial cells.

The synthesis of a group of proteins, called heat shock proteins (HSP), by cells, enable the cells to respond to different kinds of stresses. The posttranscriptional regulation of protein production involves the 3'-untranslated regions (UTR's) for the mRNAs. Through the HSP7O 3'-UTR, the heat regulates the HSP7O production, in addition to the known effects on transcription. Plasmids containing sequences, encoding the human HSP70 or beta globin 3'-UTR, were used in the transfection of the cells. The transfection identifies a heat induced mechanism of posttranscriptional control of HSP70 synthesis.

Effect of heat stress on LPS-induced febrile response in D-galactosamine-sensitized rats. Am J Physiol Regulatory Integrative Comp Physiol 280: R338-R344, 2001.--We have previously reported that heat conditioning augments lipopolysaccharide (LPS)-induced fewer in rats, which is accompanied by an accumulation of heat shock protein (HSP) in the liver and the reduction of the plasma level of tumor necrosis factor (TNF-[Alpha]) (Kluger MJ, Rudolph K, Soszynski D, Conn CA, Leon LR, Kozak W, Wallen ES, and Moseley PL. Am J Physiol Regulatory Integrative Comp Physiol 273: R858-R863, 1997). In the present study we have tested whether inhibition of protein synthesis in the liver can reduce the effect of this heat conditioning on the LPS-induced febrile response in the rat. D-galactosamine (D-gal) was used to selectively inhibit liver protein synthesis, D-gal (500 mg/kg) or PBS as control was administered intraperitoneally 1 h before heat stress. LPS (50 [micro]g/kg ip) was injected 24 h post-heat exposure. Treatment with D-gal blunted the febrile response to LPS. Moreover, heat-conditioned rats treated first with D-gal and subsequently with LPS demonstrated a profound fall in core temperature 10-18 h post-LPS. A significant increase of serum TNF-[Alpha] accompanied this effect of D-gal on fever. Heat-conditioned animals receiving D-gal showed an inhibition in inducible HSP-70 in the liver. These data support the role of hepatic function in modulating the febrile response to LPS. heat shock proteins; liver; heart; kidney; tumor necrosis factor-[Alpha], interleukin-6, temperature regulation; fever; lipopolysaccharide

The article presents the study which examines whether theories of learning from computer-based multimedia might also be applied to safety training applications for working adults in the U.S. Participants of the study viewed either computer-based multimedia training with concurrent narration or narration prior to the animation, then took a five-item transfer test to measure their ability. The study suggested that design guidelines developed for younger learners may be effective for training.