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701.
The role of Hsp90 in cell response to hyperthermia   总被引:1,自引:0,他引:1  
(1) Preincubation of SKOV3 human ovarian carcinoma cells with a non-toxic dose of Geldanamycin resulted in exacerbation of hyperthermia-induced cytotoxicity and re-distribution of dying cells toward necrosis. (2) Exposure of primary human ovarian carcinoma cells to mild hyperthermia (42 °C for 2 h) led, after a recovery period of 16 h, to several-fold increase in the levels of Hsp90 and ErbB2, to a moderate decrease in the levels of phospho-Erk1/2, whereas the level of β-catenin appeared to be unchanged. (3) The inhibitors of Hsp90 (Geldanamycin and Novobiocin) significantly affected the cell signaling of heat-pretreated cultures. (4) The results suggest that Hsp90 plays a pivotal role in cell response to hyperthermia. (5) A combination of Hsp90 inhibitors with hyperthermia may considerably increase the efficacy of thermotherapy.  相似文献   
702.
The buccal and lingual roots of 1077 teeth from 100 mandibles of South African Negroes were examined for the presence of dehiscences and fenestrae. All specimens were obtained from cadavers of known sex, tribe, and stated age; 10.5% of teeth were affected. Canines and first premolars were the most common teeth associated with dehiscences and fenestrae. Dehiscences occurred more commonly than fenestrae (1:0.49). The defects were found exclusively in the buccal plate of the alveolar process.  相似文献   
703.
Sandhill Cranes Antigone canadensis exhibit delayed sexual maturity and breeding, and therefore juvenile Cranes searching for suitable territories to occupy have different ecological constraints on movements than adults, which must defend a territory and raise young. We used fine-scale GPS telemetry data to characterize and compare movements of adult and juvenile Cranes near the boundary between two populations in Minnesota, USA, from arrival on natal areas in the spring until staging prior to autumn migration. Juvenile and adult Cranes had marked differences in movement patterns throughout the breeding season. Juveniles were more likely than adults to display long-distance movements: they revisited areas less frequently throughout the breeding season and they had lower average residence times.  相似文献   
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705.
Cucurbitacins I and D and two new cucurbitacins, isocucurbitacin D and 3-epi-isocucurbitacin D, were isolated from Phormium tenax. A new cucurbitacin, dihydroisocucurbitacin B, was isolated from Marah oreganus. The acid sensitivity of the 2β-hydroxy-3-keto system found in cucurbitacin D was demonstrated.  相似文献   
706.
Normal rat kidney cells, infected with Moloney murine leukemia virus, were treated with 3-methylcholanthrene at passage 5 postinfection. Foci of transformed cells appeared after 9-11 passages following this treatment. Characterization of four different randomly isolated foci revealed a striking diversity with respect to various tested phenotypic parameters. Remarkable differences were observed among these transformed clones regarding their cell morphology, growth rate, saturation density, serum requirements, virus release and its response to rat and mouse fibroblast interferons. This study demonstrates that cell transformation by chemical-retroviral co-carcinogenesis may lead to the formation of phenotypically heterogeneous tumor cells.  相似文献   
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709.
Daily rhythms of nonshivering thermogenesis NST were studied in common spiny mice Acomys cahirinus, acclimated to different photoperiod regimes (16L:8D and 8L:16D) at a constant ambient temperature of 26°C. Noradrenaline NA (1.5 mg/kg subcutaneous) was injected at: 06:00, 12:00, 18:00 and 24:00 h (±15 min). NST was measured as the ratio between the maximal oxygen consumption (VO2) as response to NA — VO2NA and VO2 measured at 26°C — VO2 min. Rectal temperatures TbNA and Tb min respectively were recorded at the end of VO2 measurements. Significant variations in Tb min, TbNA, and NST were revealed, under the two different photoperiod regimes. Significant differences in VO2 min, NST, Tb min and TbNA were also recorded within each photoperiod acclimation group. These results suggest that daily and photoperiod depended variations in the brown adipose tissue activity, presumably emerge from amount of unoccupied receptors or changes in the receptors affinity to NA.  相似文献   
710.
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