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151.
Salmonella faces a variety of stresses including acid and heat, in the natural environment whether in the gastrointestinal tract of mammalian host or in the external environment during transmission where survival and multiplication is a priority for the pathogen. In the present study, Salmonella enterica serovar Typhi was grown under acid (inorganic and organic) as well as heat stress and the outermembrane protein (OMP) profiles were compared. A 55 kDa OMP was found to be expressed with high intensity under the selected stress conditions in comparison to normal conditions. The protein expressed under acidic stress reacted with antibodies raised against heat shock protein indicating the similarity of atleast some of the epitopes. In vivo immunogenicity (reactivity with typhoid patient sera) revealed that the 55kDa protein under each stress condition was reactive with 83% of the typhoid sera. In the light of role of the stress induced proteins in pathogenesis of microbial infections and their immunogenic potential, these findings may be relevant for a better understanding of the host-microbe interactions and for future development of diagnostic and preventive strategies. 相似文献
152.
Yong H Gu YG Clark RF Marron T Ma Z Soni N Stone GG Nilius AM Marsh K Djuric SW 《Bioorganic & medicinal chemistry letters》2005,15(10):2653-2658
A novel series of 6-O-arylpropargyl diazalides was synthesized and evaluated for their antibacterial activity. Members of this series exhibited potent activity against erythromycin-resistant respiratory tract pathogens. 相似文献
153.
Jitendra A. Sattigeri Malvika Garg Pragya Bhateja Ajay Soni Abdul Rehman Abdul Rauf Mahendrakumar Gupta Mahesh S. Deshmukh Tarun Jain Nidhi Alekar Tarani Kanta Barman Paras Jha Tridib Chaira Ramesh B. Bambal Dilip J. Upadhyay Takahide Nishi 《Bioorganic & medicinal chemistry letters》2018,28(17):2993-2997
FimH is a type I fimbrial lectin located at the tip of type-1 pili of Gram-negative uropathogenic Escherichia coli (UPEC) guiding its ability to adhere and infect urothelial cells. Accordingly, blocking FimH with small molecule inhibitor is considered as a promising new therapeutic alternative to treat urinary tract infections caused by UPEC. Herein, we report that compounds having the S-glycosidic bond (thiomannosides) had improved metabolic stability and plasma exposures when dosed orally. Especially compound 5h showed the potential to inhibit biofilm formation and also to disrupt the preformed biofilm. And compound 5h showed prophylactic effect in UTI model in mice. 相似文献
154.
Summary The steady-state concentration of M. trichosporium OB3b increased about two-fold in the continuous culture when the feeding medium was supplemented by ferrous sulphate (50mg/L) and citric acid (100mg/L) at a steady state. In batch and continuous cultures, the cell growth was significantly inhibited by excess N-sources (NH4OH, NH4Cl, NH4NO3, HNO3, and NaNO3) and ammonium N-sources were more inhibitory. Both volumetric O2 transfer coefficient and specific O2 uptake rate increased monotonously in an extensive range of air flow rate (0.1–7 vvm) and the methane interfered with the O2 transfer even at very low flow rates (0.01–0.1 vvm). 相似文献
155.
A family of cyclin D homologs from plants differentially controlled by growth regulators and containing the conserved retinoblastoma protein interaction motif. 总被引:21,自引:2,他引:19 下载免费PDF全文
A new family of three related cyclins has been identified in Arabidopsis by complementation of a yeast strain deficient in G1 cyclins. Individual members show tissue-specific expression and are conserved in other plant species. They form a distinctive group of plant cyclins, which we named delta-type cyclins to indicate their similarities with mammalian D-type cyclins. The sequence relationships between delta and D cyclins include the N-terminal sequence LXCXE. This motif was originally identified in certain viral oncoproteins and is strongly implicated in binding to the retinoblastoma protein pRb. By analogy to mammalian cyclin D, these plant homologs may mediate growth and phytohormonal signals into the plant cell cycle. In support of this hypothesis, we show that, on restimulation of suspension-cultured cells, cyclin delta 3 is rapidly induced by the plant growth regulator cytokinin and cyclin delta 2 is induced by carbon source. 相似文献
156.
Sachin Patel Deepti Joshi Rani Soni Drista Sharma 《Journal of biomolecular structure & dynamics》2016,34(6):1330-1344
Millions of deaths occur every year due to malaria. Growing resistance against existing drugs for treatment of malaria has exaggerated the problem further. There is an intense demand of identifying drug targets in malaria parasite. PfPRL-PTP protein is PRL group of phosphatase, and one of the interesting drug targets being involved in three important pathways of malaria parasite (secretion, phosphorylation, and prenylation). Therefore, in this study, we have modeled three-dimensional structure of PfPRL-PTP followed by validation of 3D structure using RAMPAGE, verify3D, and other structure validation tools. We could identify 12 potential inhibitory compounds using in silico screening of NCI library against PfPRL-PTP with Glide. The molecular dynamics simulation was also performed using GROMACS on PfPRL-PTP model alone and PfPRL-PTP-inhibitor complex. This study of identifying potential drug-like molecules would add up to the process of drug discovery against malaria parasite. 相似文献
157.
Siddarth Srinivasan Ioana D. Vladescu Stephan A. Koehler Xiaoling Wang Madhav Mani Shmuel M. Rubinstein 《Biophysical journal》2018,114(6):1490-1498
Bacterial biofilms are surface-attached microbial communities encased in self-produced extracellular polymeric substances. Here we demonstrate that during the development of Bacillus subtilis biofilms, matrix production is localized to an annular front propagating at the periphery and sporulation to a second front at a fixed distance at the interior. We show that within these fronts, cells switch off matrix production and transition to sporulation after a set time delay of ~100 min. Correlation analyses of fluctuations in fluorescence reporter activity reveal that the fronts emerge from a pair of gene-expression waves of matrix production and sporulation. The localized expression waves travel across cells that are immobilized in the biofilm matrix in contrast to active cell migration or horizontal colony spreading. Our results suggest that front propagation arises via a local developmental program occurring at the level of individual bacterial cells, likely driven by nutrient depletion and metabolic by-product accumulation. A single-length scale and timescale couples the spatiotemporal propagation of both fronts throughout development. As a result, gene expression patterns within the advancing fronts collapse to self-similar expression profiles. Our findings highlight the key role of the localized cellular developmental program associated with the propagating front in describing biofilm growth. 相似文献
158.
OBJECTIVE--To examine the levels of general practitioner consultations among the different ethnic groups resident in Britain. DESIGN--The study was based on the British general household surveys of 1983-5 and included 63,966 people aged 0-64. Odds ratios were derived for consultation by ethnic group by using logistic regression analysis adjusting for age and socioeconomic group. SETTING--The results relate to people living in private households in England, Scotland, and Wales. RESULTS--After adjustment for age and socioeconomic class, consultation among adults aged 16-64 was highest among people of Pakistani origin with odds ratios of 2.82 (95% confidence interval 1.86 to 4.28) for men and 1.85 (1.22 to 2.81) for women. Significantly higher consultations were also seen for men of West Indian and Indian origin (odds ratios 1.65 and 1.53 respectively). Ethnic differences were greatest at ages 45-64, when consultation rates in people of Pakistani, Indian, and West Indian origin were much higher in both sexes compared with white people. CONCLUSIONS--The ethnic composition of inner cities is likely to influence the workload and case mix of general practitioners working in these areas. 相似文献
159.
The effect of pH (between 4.4 and 6.6) on butyrate uptake by the mutant strain of Clostridium acetobutylicum was studied using the fermentation broth from fermentor-2 (solventogenic stage) of a two-fermentor continuous system. Low pH (4.6) adversely affected the overall metabolic activity as observed by low solvent production and carbohydrate consumption. Uptake of 4.0?±?0.5?g l?1 butyrate, under batch incubation at 30?°C, was not inhibited at pH?>?5.2, however, at pH?5.2, a marked inhibition in butyrate uptake was noticed. A higher pH (e.g. pH 5.4) was required for the uptake of elevated concentration of externally added butyrate at 8.5?±?1.0?g l?1. Batch incubation at relatively higher temperatures (35° and 37?°C) indicated a similar trend i.e., a pH of >5.5 was required for uptake of >8?g l?1 butyrate. Optimization studies for butyrate uptake by C. acetobutylicum suggested a direct correlation between minimum pH and butyrate concentration or temperature. The role of undissociated butyric acid appears to be critical in regulation of butyrate uptake. 相似文献
160.
Functional tissue engineering of connective tissues such as the anterior cruciate ligament (ACL) remains a significant clinical challenge, largely due to the need for mechanically competent scaffold systems for grafting, as well as a reliable cell source for tissue formation. We have designed an aligned, polylactide-co-glycolide (PLGA) nanofiber-based scaffold with physiologically relevant mechanical properties for ligament regeneration. The objective of this study is to identify optimal tissue engineering strategies for fibroblastic induction of human mesenchymal stem cells (hMSC), testing the hypothesis that basic fibroblast growth factor (bFGF) priming coupled with tensile loading will enhance hMSC-mediated ligament regeneration. It was observed that compared to the unloaded, as well as growth factor-primed but unloaded controls, bFGF stimulation followed by physiologically relevant tensile loading enhanced hMSC proliferation, collagen production and subsequent differentiation into ligament fibroblast-like cells, upregulating the expression of types I and III collagen, as well as tenasin-C and tenomodulin. The results of this study suggest that bFGF priming increases cell proliferation, while mechanical stimulation of the hMSCs on the aligned nanofiber scaffold promotes fibroblastic induction of these cells. In addition to demonstrating the potential of nanofiber scaffolds for hMSC-mediated functional ligament tissue engineering, this study yields new insights into the interactive effects of chemical and mechanical stimuli on stem cell differentiation. 相似文献