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排序方式: 共有417条查询结果,搜索用时 15 毫秒
1.
R A Rathod L J Bhagia G L Pandya V L Katagade D J Parikh B B Chatterjee 《European journal of applied physiology and occupational physiology》1987,56(1):58-63
A preliminary survey of the few units of the small-scale glass bangle industry in Firozabad, Agra District, Uttar Pradesh, indicated that the workers were exposed to severe degrees of heat stress during various operations in the manufacturing processes. A more detailed study in eight glass bangle units was therefore undertaken to make quantitative estimates of heat stress on exposed workers in the summer season. The thermal data collected confirmed that the heat stress on the workers was severe but measurement of certain physiological indicators revealed relatively low levels of strain amongst the exposed workers. The findings could be attributable to high degrees of acclimatization, but further observations in the field supplemented by studies on simulated exposures of volunteers in a climatic chamber seem to be warranted. 相似文献
2.
A path from mitochondria to the yeast nucleus 总被引:2,自引:0,他引:2
3.
Mitogen-like monoclonal anti-actin antibodies 总被引:1,自引:0,他引:1
H M Rosenblatt N Parikh J E McClure I Meza S Y Hwo J Bryan W T Shearer 《Journal of immunology (Baltimore, Md. : 1950)》1985,135(2):995-1000
Monoclonal antibodies (IgM kappa) have been produced to actin isolated electrophoretically from L cell extracts. These monoclonal anti-actin antibodies bind to intact L cells and modulate DNA synthesis and cell proliferation, much like affinity-purified polyclonal rabbit antibody to the same Mr 42,000 actin. In addition, monoclonal antibodies specific for actin from Entamoeba histolytica also bound to and modulated the growth of L cells. A monoclonal antibody directed against a neuroblastoma surface antigen did not produce stimulation of L cells, and the binding activity of anti-actin monoclonal antibody to L cells was removed by absorption with actin covalently coupled to Sepharose. These observations demonstrate the specificity of interaction between the anti-actin monoclonal antibodies and the surface of intact L cells. We conclude that a surface actin-like molecule on the L cell, when bound by specific monoclonal antibody, initiates a stimulatory signal which results in enhanced cellular metabolism. 相似文献
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6.
John D. Loike Anna Plitt Komal Kothari Jona Zumeris Sadna Budhu Kaitlyn Kavalus Yonatan Ray Harold Jacob 《PloS one》2013,8(8)
Biofilms are structured communities of bacteria that play a major role in the pathogenicity of bacteria and are the leading cause of antibiotic resistant bacterial infections on indwelling catheters and medical prosthetic devices. Failure to resolve these biofilm infections may necessitate the surgical removal of the prosthetic device which can be debilitating and costly. Recent studies have shown that application of surface acoustic waves to catheter surfaces can reduce the incidence of infections by a mechanism that has not yet been clarified. We report here the effects of surface acoustic waves (SAW) on the capacity of human neutrophils to eradicate S. epidermidis bacteria in a planktonic state and within biofilms. Utilizing a novel fibrin gel system that mimics a tissue-like environment, we show that SAW, at an intensity of 0.3 mW/cm2, significantly enhances human neutrophil killing of S. epidermidis in a planktonic state and within biofilms by enhancing human neutrophil chemotaxis in response to chemoattractants. In addition, we show that the integrin CD18 plays a significant role in the killing enhancement observed in applying SAW. We propose from out data that this integrin may serve as mechanoreceptor for surface acoustic waves enhancing neutrophil chemotaxis and killing of bacteria. 相似文献
7.
Komal Raina Chapla Agarwal Ritambhara Wadhwa Natalie J. Serkova Rajesh Agarwal 《Autophagy》2013,9(5):697-713
Small molecules with the potential to initiate different types of programmed cell death could be useful ‘adjunct therapy’ where current anticancer modalities fail to generate significant activity due to a defective apoptotic machinery or resistance of cancer cells to the specific death mechanism induced by that treatment. The current study identified silibinin, for the first time, as one such natural agent, having dual efficacy against colorectal cancer (CRC) cells. First, silibinin rapidly induced oxidative stress in CRC SW480 cells due to reactive oxygen species (ROS) generation with a concomitant dissipation of mitchondrial potential (ΔΨm) and cytochrome c release leading to mild apoptosis as a biological effect. However, with increased exposure to silibinin, cytoplasmic vacuolization intensified within the cells followed by sequestration of the organelles, which inhibits the further release of cytochrome c. Interestingly, this decrease in apoptotic response correlated with increased autophagic events as evidenced by tracking the dynamics of LC3-II within the cells. Mechanistic studies revealed that silibinin strongly inhibited PIK3CA-AKT–MTOR but activated MAP2K1/2-MAPK1/3 pathways for its biological effects. Corroborating these effects, endoplasmic reticulum stress was generated and glucose uptake inhibition as well as energy restriction were induced by silibinin, thus, mimicking starvation-like conditions. Further, the cellular damage to tumor cells by silibinin was severe and irreparable due to sustained interference in essential cellular processes such as mitochondrial metabolism, phospholipid and protein synthesis, suggesting that silibinin harbors a deadly ‘double-edged sword’ against CRC cells thereby further advocating its clinical effectiveness against this malignancy. 相似文献
8.
Nimra Akram Naheed Khan Mehreen Ameen Shahmeera Mahmood Komal Shamim Marium Amin 《Chronobiology international》2013,30(9):1262-1268
ABSTRACTSeveral studies have focused on determining the effect of chronotype and learning approach on academic achievement separately indicating that morning types have an academic advantage over the evening types and so have the deep learners over the surface learners. But, surprisingly none have assessed the possible relationship between chronotype and learning approach. So, the current study aimed to evaluate this association and their individual influence on academic performance as indicated by the Cumulative Grade Point Average (CGPA) as well as the effect of their interaction on academic performance. The study included 345 undergraduate medical students who responded to reduced Morningness-Eveningness Questionnaire and Biggs Revised Two-Factor Study Process Questionnaire. Morning types indulged in deep learning while evening types in surface learning. Morning and evening types did not differ on academic performance but deep learners had better academic outcomes than their counterparts. The interaction between chronotype and learning approach was significant on determining academic achievement. Our findings gave the impression that chronotype could have an impact on academic performance not directly but indirectly through learning approaches. 相似文献
9.
Biomineralization in heterogeneous aqueous systems results from a complex association between pre-existing surfaces, bacterial cells, extracellular biomacromolecules, and neoformed precipitates. Fourier transform infrared (FTIR) spectroscopy was used in several complementary sample introduction modes (attenuated total reflectance [ATR], diffuse reflectance [DRIFT], and transmission) to investigate the processes of cell adhesion, biofilm growth, and biological Mn-oxidation by Pseudomonas putida strain GB-1. Distinct differences in the adhesive properties of GB-1 were observed upon Mn oxidation. No adhesion to the ZnSe crystal surface was observed for planktonic GB-1 cells coated with biogenic MnO x , whereas cell adhesion was extensive and a GB-1 biofilm was readily grown on ZnSe, CdTe, and Ge crystals prior to Mn-oxidation. IR peak intensity ratios reveal changes in biomolecular (carbohydrate, phosphate, and protein) composition during biologically catalyzed Mn-oxidation. In situ monitoring via ATR-FTIR of an active GB-1 biofilm and DRIFT data revealed an increase in extracellular protein (amide I and II) during Mn(II) oxidation, whereas transmission mode measurements suggest an overall increase in carbohydrate and phosphate moieties. The FTIR spectrum of biogenic Mn oxide comprises Mn-O stretching vibrations characteristic of various known Mn oxides (e.g., “acid” birnessite, romanechite, todorokite), but it is not identical to known synthetic solids, possibly because of solid-phase incorporation of biomolecular constituents. The results suggest that, when biogenic MnO x accumulates on the surfaces of planktonic cells, adhesion of the bacteria to other negatively charged surfaces is hindered via blocking of surficial proteins. 相似文献
10.
Dong Hyun Kim Nitin Puri Komal Sodhi John R. Falck Nader G. Abraham Joseph Shapiro Michal L. Schwartzman 《Journal of lipid research》2013,54(3):786-793
20-Hydroxy-5,8,11,14-eicosatetraenoic acid (20-HETE), a product of the cytochrome
P450 (CYP)-catalyzed ω-hydroxylation of arachidonic acid, induces
oxidative stress and, in clinical studies, is associated with increased body
mass index (BMI) and the metabolic syndrome. This study was designed to examine
the effects of exogenous 20-HETE on mesenchymal stem cell (MSC)-derived
adipocytes. The expression levels of CYP4A11 and CYP4F2 (major 20-HETE synthases
in humans) in MSCs decreased during adipocyte differentiation; however,
exogenous administration of 20-HETE (0.1–1 μM) increased adipogenesis
in a dose-dependent manner in these cells (P < 0.05). The
inability of a 20-HETE analog to reproduce these effects suggested the
involvement of a metabolic product of 20-HETE in mediating its pro-adipogenic
effects. A cyclooxygenase (COX)-1 selective inhibitor enhanced, whereas a COX-2
selective or a dual COX-1/2 inhibitor attenuated adipogenesis induced by
20-HETE. The COX-derived metabolite of 20-HETE, 20-OH-PGE2, enhanced
adipogenesis and lipid accumulation in MSCs. The pro-adipogenic effects of
20-HETE and 20-OH-PGE2 resulted in the increased expression of the
adipogenic regulators PPARγ and β-catenin in MSC-derived adipocytes.
Taken together we show for the first time that 20-HETE-derived COX-2-dependent
20-OH-PGE2 enhances mature inflamed adipocyte hypertrophy in MSC
undergoing adipogenic differentiation. 相似文献