The function of one or more heat shock proteins (HSPs) may be to confer protection of cells against thermal damage. We examined the induction kinetics of thermotolerance and the synthesis of HSPs in murine tumor models. Squamous cell carcinomas (SCC VII/SF) or radiation-induced fibrosarcomas (RIF) were implanted in the flanks of C3H mice. These flank tumors were first exposed to an elevated tem...

The effects of 2-(4-Morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002), an inhibitor of mammalian phosphatidylinositol 3-OH kinase, was tested on an insulin signaling-like pathway in the nematode Caenorhabditis elegans. Populations of C. elegans were treated with LY294002 at different stages of the life cycle, and its effects on development, thermotolerance and longevity were assessed. At c...

The effect of prior heat shock (48 degrees C for 15 min) on the thermotolerance of Listeria monocytogenes at the minimal high-temperature, short-time (71.7 degrees C for 15 s) parameters required by the Pasteurized Milk Ordinance was examined. The mean D71.7 degrees C value for heat-shocked L. monocytogenes was 4.6 +/- 0.5 s (control D = 3.0 +/- 1.0 s); the ratio of D to control D was 1.5. The ...

Tradeoffs in performance or fitness across environments have important implications regarding the nature of evolutionary constraints. It remains controversial whether tradeoffs such as these reflect genetic correlations that are genuine evolutionary constraints. However, if such long-term genetic constraints do exist, they must be due to underlying pleiotropy such that alleles that confer high ...

The current status and needs of thermal biology and physiol ogy as related to clinical hyperthermia are summarized. Empha sis is placed on heat-induced modification of blood flow and microenvironment in tissues, on the biological effects of heat and X-rays, and on the relationship between drug resistance, heat resistance, and thermotolerance in thermochemotherapy. Re sults from recent studies i...

The current status and needs of thermal biology and physiology as related to clinical hyperthermia are summarized. Emphasis is placed on heat-induced modification of blood flow and microenvironment in tissues, on the biological effects of heat and X-rays, and on the relationship between drug resistance, heat resistance, and thermotolerance in thermochemotherapy. Results from recent studies inve...

Superoxide dismutase (SOD) activity in Chinese hamster ovary (CHO) and ovarian carcinoma (OvCa) cells was measured after exposure to hyperthermia and correlated with the development of thermotolerance. The SOD activity of each cell type was largely copper- and zinc-containing SOD activity. Both cell types had similar but low levels of SOD activity when the cells were grown at 37 degrees C. Afte...

Five mutants of Trichophyton mentagrophytes with changed optimum cultivation temperature and the wild strain were used in this study. The growth rates, the keratinolytic activities and the 1-D electrophoretic patterns of these mutants were examined repeatedly. The differences among the individual mutants and the wild strain can be useful for a better understanding of the participating individua...