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Of Stresses (of + stress)

Distribution by Scientific Domains
Life Sciences57%
Medical Sciences28%

Kinds of Of Stresses

  • variety of stress
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    Selected Abstracts

    Differential stress-induced alterations of colonic corticotropin-releasing factor receptors in the Wistar Kyoto rat

    NEUROGASTROENTEROLOGY & MOTILITY, Issue 3 2010
    D. O'malley
    Abstract Background, A growing body of data implicates increased life stresses with the initiation, persistence and severity of symptoms associated with functional gut disorders such as irritable bowel syndrome (IBS). Activation of central and peripheral corticotropin-releasing factor (CRF) receptors is key to stress-induced changes in gastrointestinal (GI) function. Methods, This study utilised immunofluorescent and Western blotting techniques to investigate colonic expression of CRF receptors in stress-sensitive Wistar Kyoto (WKY) and control Sprague Dawley (SD) rats. Key Results, No intra-strain differences were observed in the numbers of colonic CRFR1 and CRFR2 positive cells. Protein expression of functional CRFR1 was found to be comparable in control proximal and distal colon samples. Sham levels of CRFR1 were also similar in the proximal colon but significantly higher in WKY distal colons (SD: 0.38 ± 0.14, WKY: 2.06 ± 0.52, P < 0.01). Control levels of functional CRFR2 were similar between strains but sham WKYs samples had increased CRFR2 in both the proximal (SD: 0.88 ± 0.21, WKY: 1.8 ± 0.18, P < 0.001) and distal (SD: 0.18 ± 0.08, WKY: 0.94 ± 0.32, P < 0.05) regions. Exposure to open field (OF) and colorectal distension (CRD) stressors induced decreased protein expression of CRFR1 in SD proximal colons, an effect that was blunted in WKYs. CRD stimulated decreased expression of CRFR2 in WKY rats alone. Distally, CRFR1 is decreased in WKY rats following CRD but not OF stress without any apparent changes in SD rats. Conclusions & Inferences, This study demonstrates that psychological and physical stressors alter colonic CRF receptor expression and further support a role for local colonic CRF signalling in stress-induced changes in GI function. [source]

    Comparative genome analysis of a Saccharomyces cerevisiae wine strain

    FEMS YEAST RESEARCH, Issue 7 2008
    Anthony R. Borneman
    Abstract Many industrial strains of Saccharomyces cerevisiae have been selected primarily for their ability to convert sugars into ethanol efficiently despite exposure to a variety of stresses. To begin investigation of the genetic basis of phenotypic variation in industrial strains of S. cerevisiae, we have sequenced the genome of a wine yeast, AWRI1631, and have compared this sequence with both the laboratory strain S288c and the human pathogenic isolate YJM789. AWRI1631 was found to be substantially different from S288c and YJM789, especially at the level of single-nucleotide polymorphisms, which were present, on average, every 150 bp between all three strains. In addition, there were major differences in the arrangement and number of Ty elements between the strains, as well as several regions of DNA that were specific to AWRI1631 and that were predicted to encode proteins that are unique to this industrial strain. [source]

    The stress response is repressed during fermentation in brewery strains of yeast

    JOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2000
    M.P. Brosnan
    Yeast cells encounter a variety of environmental stresses during brewing and must respond to ensure cell survival. Cells can respond to stress by inducing a Heat Shock Response in which heat shock proteins (Hsps) are synthesized. In laboratory strains of Saccharomyces cerevisiae, the heat shock protein, Hsp104, plays a major role in the acquisition of tolerance to a variety of stresses such as heat, ethanol and sodium arsenite, and as such acts as an excellent stress indicator. The induction of Hsp104 in bottom-and top-fermenting brewery strains was examined when grown under laboratory and industrial fermentation conditions, and it was found that each brewing strain exhibits its own unique pattern of Hsp104 expression. During industrial fermentations, brewery strains are capable of mounting a stress response at the early stages of fermentation. However, as the fermentation proceeds, the response is repressed. The results suggest that conditions experienced in industrial brewing prevent the activation of the stress response. This study increases our understanding of alterations in gene expression patterns during the brewing process, and yields information that will aid in the definition of best practice in yeast management. [source]

    Involvement of the INK4a/Arf gene locus in senescence

    AGING CELL, Issue 3 2003
    Carol J. Collins
    Summary The INK4a/ARF locus encodes two proteins whose expression limits cellular proliferation. Whilst the biochemical activities of the two proteins appear very different, they both converge on regulating the retinoblastoma and p53 tumour suppressor pathways. Neither protein is required for normal development, but lack of either predisposes to the development of malignancy. Both proteins have also been implicated in the establishment of senescence states in response to a variety of stresses, signalling imbalances and telomere shortening. The INK4a/Arf regulatory circuits appear to be partially redundant and show evidence of rapid evolution. Especially intriguing are the large number of biological differences documented between mice and man. We review here the brief history of INK4a/Arf and explore possible links with organismal aging and the evolution of longevity. [source]

    Characterization of antibody aggregation: Role of buried, unpaired cysteines in particle formation

    JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 2 2010
    Stephen R. Brych
    Abstract Proteins are susceptible to degradation upon exposure to a variety of stresses during product manufacturing, transportation and storage. In this study, we investigated the aggregation properties of a monoclonal antibody during agitation stress. Agitation exclusively led to insoluble aggregates, or particle formation. Removal or modification of the air,liquid interface with a surfactant (e.g., polysorbate) abrogated particle formation. The supernatant postagitation was analyzed using SE-HPLC, FTIR, and AUC analyses and revealed no changes in conformation and aggregation profile when compared to the nonagitated antibody sample. The antibody particles were comprised of a combination of nonnative intermolecular disulfide-linked covalent as well as noncovalent interactions. Analysis of the antibody's unpaired cysteines revealed that the nonnative intermolecular disulfide bonds were formed through buried cysteines, which suggested at least partial unfolding of the antibody domains. FTIR analysis indicated that the particulated antibody maintained significant native-like secondary structure suggesting that particle formation led to minimal structure changes, but capable of exposing free cysteines to solvent to form the nonnative intermolecular disulfide bonds. The results presented in this study indicate the importance of the interactions between the antibody and the air,liquid interface during agitation in the formation of particles and suggests that reduced disulfide bonds may play a significant role in the particulation reaction. This phenomenon can be applicable to other proteins with similar free cysteine and structural characteristics. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:764,781, 2010 [source]

    Segregation patterns of AFLP markers in F1 hybrids of a cross between tetraploid and diploid species in the genus Malus

    PLANT BREEDING, Issue 4 2004
    Y. H. Li
    Abstract Malus xiaojinensis, one of the most important wild genotypes in the genus Malus, is resistant to a variety of stresses such as Fe deficiency chlorosis, drought and cold. However, lack of knowledge of its genetic background prevents using genetic analysis to study those agronomic traits and corresponding gene functions. Here, as the first step towards construction of the linkage map of M. xiaojinensis, genetic analysis of the F1 triploid hybrids (M. xiaojinensis × M. baccata) was performed with amplified fragment length polymorphism (AFLP) markers. Using 15 EcoRI- MseI primer combinations, 1110 AFLPs were identified, with 31.3% of M. xiaojinensis -, 12.7% of M. baccata-specific markers, 54.9% of common markers, and 1.2% of non-parental markers; 93.3% of the AFLP markers exhibit the expected segregation ratio. Thirty-two M. xiaojinensis -specific markers and 47 common markers display a 5 : 1 and 11:1 segregation ratios, respectively, suggesting that M. xiaojinensis is an autotetraploid, or at least an isosyndetic allotetraploid. [source]

    ESE-3, an Ets family transcription factor, is up-regulated in cellular senescence

    CANCER SCIENCE, Issue 9 2007
    Makoto Fujikawa
    Normal cells irreversibly stop dividing after being exposed to a variety of stresses. This state, called cellular senescence, has recently been demonstrated to act as a tumor-suppressing mechanism in vivo. A common set of features are exhibited by senescent cells, but the molecular mechanism leading to the state is poorly understood. It has been shown that p38, a stress-induced mitogen-activated protein kinase (MAPK), plays a pivotal role in inducing cellular senescence in diverse settings. To better understand the senescence-inducing pathway, microarray analyses of normal human fibroblasts that ectopically activated p38 were performed. It was found that five genes encoding ESE-3, inhibin ,A, RGS5, SSAT and DIO2 were up-regulated in senescent cells induced by RasV12, H2O2 and telomere shortening, but not in quiescent or actively growing cells, suggesting that these genes serve as molecular markers for various types of cellular senescence. The ectopic expression of ESE-3 resulted in retarded growth, up-regulation of p16INK4a but not of p21, and increased levels of SA-,-gal activity. In contrast, RGS5, SSAT and the constitutive active form of the inhibin ,A receptor gene did not induce such senescence phenotypes when ectopically expressed. ESE-3 expression increased the activity of the p16INK4a promoter in a reporter assay, and recombinant ESE-3 protein bound to the Ets-binding sequences present in the promoter. These results suggest that ESE-3 plays a role in the induction of cellular senescence as a downstream molecule of p38. (Cancer Sci 2007; 98: 1468,1475) [source]