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Variation in heat-shock proteins among species of desert fishes (Poeciliidae, Poeciliopsis) 总被引:4,自引:0,他引:4
Analysis of the heat-shock proteins (hsps) of six closely related species
of Poeciliopsis demonstrated the existence of biochemical diversity in the
hsp100, hsp70, hsp60, and hsp30 protein families among species. Each
species expressed five to seven hsp70-related isoforms. Constitutive 70-kD
isoforms were identical among species, but four different patterns of
heat-inducible isoforms were seen in these six species. Members of the
hsp70 family of molecular chaperones are included among the most highly
conserved proteins known, and the possibility of variation in hsp70 among
closely related species has rarely been addressed. The hsp30 family is
known to be less conserved than the hsp70 family, and, as expected, the
Poeciliopsis hsp30 patterns showed more variation. Most of the hsp30
isoforms characteristic of a particular species were unique to that
species. Hsp100 and hsp60 were identical in five of the species, but
alternate isoforms were found in P. monacha. The small size and limited
geographical distribution of the P. monacha population have probably
contributed to the uniqueness of the monacha pattern. Two of the species
were shown to acquire thermotolerance, the ability to withstand normally
lethal temperatures when subjected to a gradual temperature increase.
Rapid-heating protocols commonly used to establish critical thermal maxima
of organisms do not include this inducible component of thermoresistance
and therefore do not adequately assess an organism's capacity to withstand
thermal stress.
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In clinical neurology, a comprehensive understanding of consciousness has been regarded as an abstract concept - best left
to philosophers. However, times are changing and the need to clinically assess consciousness is increasingly becoming a real-world,
practical challenge. Current methods for evaluating altered levels of consciousness are highly reliant on either behavioural
measures or anatomical imaging. While these methods have some utility, estimates of misdiagnosis are worrisome (as high as
43%) - clearly this is a major clinical problem. The solution must involve objective, physiologically based measures that
do not rely on behaviour. This paper reviews recent advances in physiologically based measures that enable better evaluation
of consciousness states (coma, vegetative state, minimally conscious state, and locked in syndrome). Based on the evidence
to-date, electroencephalographic and neuroimaging based assessments of consciousness provide valuable information for evaluation
of residual function, formation of differential diagnoses, and estimation of prognosis. 相似文献
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Huiming Xu Kam Sze Tsang Yonghui Wang Juliana CN Chan Gang Xu Wei-Qiang Gao 《The Journal of biological chemistry》2014,289(38):26290-26301
Tremendous efforts have been made to elucidate the molecular mechanisms that control the specification of definitive endoderm cell fate in gene knockout mouse models and ES cell (ESC) differentiation models. However, the impact of the unfolded protein response (UPR), because of the stress of the endoplasmic reticulum on endodermal specification, is not well addressed. We employed UPR-inducing agents, thapsigargin and tunicamycin, in vitro to induce endodermal differentiation of mouse ESCs. Apart from the endodermal specification of ESCs, Western blotting demonstrated the enhanced phosphorylation of Smad2 and nuclear translocation of β-catenin in ESC-derived cells. The inclusion of the endoplasmic reticulum stress inhibitor tauroursodeoxycholic acid to the induction cultures prevented the differentiation of ESCs into definitive endodermal cells even when Activin A was supplemented. Also, the addition of the TGF-β inhibitor SB431542 and the Wnt/β-catenin antagonist IWP-2 negated the endodermal differentiation of ESCs mediated by thapsigargin and tunicamycin. These data suggest that the activation of the UPR appears to orchestrate the induction of the definitive endodermal cell fate of ESCs via both the Smad2 and β-catenin signaling pathways. The prospective regulatory machinery may be helpful for directing ESCs to differentiate into definitive endodermal cells for cellular therapy in the future. 相似文献
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MR Scrochi CN Zanuzzi N Fuentealba F Nishida ME Bravi ME Pacheco 《Biotechnic & histochemistry》2017,92(8):560-568
Many viruses alter different stages of apoptosis of infected cells as a strategy for successful infection. Few studies have addressed mechanisms of equine herpesvirus 1 (EHV-1) strain-induced cell death. We investigated the effect of an abortigenic strain (AR8 strain) on heterologous Madin–Darby bovine kidney cells and homologous equine dermis (ED) cells cell lines. We compared morphologic and biochemical features of early and late apoptosis at different postinfection times. We investigated translocation of phosphatidylserine to the cell surface, nuclear fragmentation and changes in the cytoskeleton using flow cytometry and annexin V/propidium iodide staining, DNA laddering, terminal deoxynucleotidyl transferase UTP nick-end labeling assay and immunofluorescence staining of cytokeratin 18 cleavage. AR8 EVH-1 strain interfered with apoptosis in both cell lines, particularly during the middle stage of the replication cycle; this was more evident in ED cells. Although this antiapoptotic effect has been reported for other alpha herpesviruses, our findings may help elucidate how EHV-1 improves its infectivity during its cycle. 相似文献
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CHARLES PEABODY 《American anthropologist》1909,11(2):202-216
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The abnormalities disclosed by the usual laboratory diagnostic procedures (blood cell count and hemoglobin determination, sedimentation rate determination, urinalysis, and serologic test for syphilis) are compared with the number revealed by stereophotoroentgen chest examination in a series of 951 patients. The number of significant abnormalities uncovered by the routine stereophotoroentgen examination of the chest was comparable to the number disclosed by the usual laboratory procedures used in patient evaluation. Some form of radiologic examination of the chest should be included in the routine laboratory procedures required for patient evaluation. 相似文献