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Debarun Roy Souvik Dey Gopal Chandra Majumder Debdas Bhattacharyya 《Glycoconjugate journal》2014,31(4):281-288
Effects of several bivalent metal ions on the autoagglutination event in mature caprine epididymal sperm cells have been investigated using a chemically defined medium. This study demonstrates for the first time that Copper (Cu2+) ion (300 μM) has high specificity for autoagglutination of mature cauda-epididymal sperm. Head-to-head interaction of the male gametes is responsible for this event. Studies on the effect of various sugars reveal that the autoagglutinated cells can be dissociated specifically with neutralized sialic acid (50 mM), which also inhibits the sperm cell autoagglutination phenomenon. Blood serum protein fetuin, that contains terminal sialic acid residue, showed high efficacy for inhibiting this autoagglutination event at 4 μM concentration. However, asialofetuin is not capable of inhibiting this Cu2+-dependent cellular event. Mature sperm cells bound with caprine erythrocytes at their head region in presence of Cu2+ ion. The purified sperm membrane fraction isolated by aqueous two phase polymer method showed high efficacy to agglutinate erythrocytes. These sperm-erythrocyte interactions as well as sperm membrane induced haemagglutination were strongly blocked by neutralized sialic acid (50 mM). The results confirm the occurrence of unique Cu2+ dependent, sialic acid-specific lectin on the outer surface of a mammalian cell using caprine sperm as the model. The observed Cu2+-mediated cellular autoagglutination is caused by the interaction of the cell surface lectin with the lectin receptor on the surface of the neighboring homologous cell. 相似文献
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Sergey Malchenko Jianping Xie Maria de Fatima Bonaldo Elio F. Vanin Bula J. Bhattacharyya Abdelhak Belmadani Guifa Xi Vasily Galat William Goossens Richard E.B. Seftor Tadanori Tomita John Crispino Richard J. Miller Martha C. Bohn Mary J.C. Hendrix Marcelo B. Soares 《Gene》2014
In vitro neural differentiation of human embryonic stem cells (hESCs) is an advantageous system for studying early neural development. The process of early neural differentiation in hESCs begins by initiation of primitive neuroectoderm, which is manifested by rosette formation, with consecutive differentiation into neural progenitors and early glial-like cells. In this study, we examined the involvement of early neural markers – OTX2, PAX6, Sox1, Nestin, NR2F1, NR2F2, and IRX2 – in the onset of rosette formation, during spontaneous neural differentiation of hESC and human induced pluripotent stem cell (hiPSC) colonies. This is in contrast to the conventional way of studying rosette formation, which involves induction of neuronal differentiation and the utilization of embryoid bodies. Here we show that OTX2 is highly expressed at the onset of rosette formation, when rosettes comprise no more than 3–5 cells, and that its expression precedes that of established markers of early neuronal differentiation. Importantly, the rise of OTX2 expression in these cells coincides with the down-regulation of the pluripotency marker OCT4. Lastly, we show that cells derived from rosettes that emerge during spontaneous differentiation of hESCs or hiPSCs are capable of differentiating into dopaminergic neurons in vitro, and into mature-appearing pyramidal and serotonergic neurons weeks after being injected into the motor cortex of NOD-SCID mice. 相似文献
205.
Baiju R. Shah Onil Bhattacharyya Catherine H. Y. Yu Muhammad M. Mamdani Janet A. Parsons Sharon E. Straus Merrick Zwarenstein 《PLoS medicine》2014,11(2)
Background
Printed educational materials for clinician education are one of the most commonly used approaches for quality improvement. The objective of this pragmatic cluster randomized trial was to evaluate the effectiveness of an educational toolkit focusing on cardiovascular disease screening and risk reduction in people with diabetes.Methods and Findings
All 933,789 people aged ≥40 years with diagnosed diabetes in Ontario, Canada were studied using population-level administrative databases, with additional clinical outcome data collected from a random sample of 1,592 high risk patients. Family practices were randomly assigned to receive the educational toolkit in June 2009 (intervention group) or May 2010 (control group). The primary outcome in the administrative data study, death or non-fatal myocardial infarction, occurred in 11,736 (2.5%) patients in the intervention group and 11,536 (2.5%) in the control group (p = 0.77). The primary outcome in the clinical data study, use of a statin, occurred in 700 (88.1%) patients in the intervention group and 725 (90.1%) in the control group (p = 0.26). Pre-specified secondary outcomes, including other clinical events, processes of care, and measures of risk factor control, were also not improved by the intervention. A limitation is the high baseline rate of statin prescribing in this population.Conclusions
The educational toolkit did not improve quality of care or cardiovascular outcomes in a population with diabetes. Despite being relatively easy and inexpensive to implement, printed educational materials were not effective. The study highlights the need for a rigorous and scientifically based approach to the development, dissemination, and evaluation of quality improvement interventions.Trial Registration
http://www.ClinicalTrials.gov and NCT01411865 Please see later in the article for the Editors'' Summary NCT01026688相似文献206.
Manish Sharma Sankar Bhattacharyya Minu Nain Manpreet Kaur Vikas Sood Vishal Gupta Renu Khasa Malik Z Abdin Sudhanshu Vrati Manjula Kalia 《Autophagy》2014,10(9):1637-1651
Autophagy is a lysosomal degradative pathway that has diverse physiological functions and plays crucial roles in several viral infections. Here we examine the role of autophagy in the life cycle of JEV, a neurotropic flavivirus. JEV infection leads to induction of autophagy in several cell types. JEV replication was significantly enhanced in neuronal cells where autophagy was rendered dysfunctional by ATG7 depletion, and in Atg5-deficient mouse embryonic fibroblasts (MEFs), resulting in higher viral titers. Autophagy was functional during early stages of infection however it becomes dysfunctional as infection progressed resulting in accumulation of misfolded proteins. Autophagy-deficient cells were highly susceptible to virus-induced cell death. We also observed JEV replication complexes that are marked by nonstructural protein 1 (NS1) and dsRNA colocalized with endogenous LC3 but not with GFP-LC3. Colocalization of NS1 and LC3 was also observed in Atg5 deficient MEFs, which contain only the nonlipidated form of LC3. Viral replication complexes furthermore show association with a marker of the ER-associated degradation (ERAD) pathway, EDEM1 (ER degradation enhancer, mannosidase α-like 1). Our data suggest that virus replication occurs on ERAD-derived EDEM1 and LC3-I-positive structures referred to as EDEMosomes. While silencing of ERAD regulators EDEM1 and SEL1L suppressed JEV replication, LC3 depletion exerted a profound inhibition with significantly reduced RNA levels and virus titers. Our study suggests that while autophagy is primarily antiviral for JEV and might have implications for disease progression and pathogenesis of JEV, nonlipidated LC3 plays an important autophagy independent function in the virus life cycle. 相似文献
207.
In a recent work (Basu et al., in EPL 105:28007, 2014) it was pointed out that the link-weight distribution of microRNA co-target network of a wide class of species are universal up to scaling. The number cell types, widely accepted as a measure of complexity, turns out to be proportional to these scale-factor. In this article we discuss additional universal features of these networks and show that, this universality splits if one considers distribution of number of common targets of three or more number of microRNAs. These distributions for different species can be collapsed onto two distinct set of universal functions, revealing the fact that the species which appeared in early evolution have different complexity measure compared to those appeared late. 相似文献
208.
Subodh K. Srivastava Xiaoqiu Huang Hargeet K. Brar Ahmad M. Fakhoury Burton H. Bluhm Madan K. Bhattacharyya 《PloS one》2014,9(1)
Fusarium virguliforme causes sudden death syndrome (SDS) of soybean, a disease of serious concern throughout most of the soybean producing regions of the world. Despite the global importance, little is known about the pathogenesis mechanisms of F. virguliforme. Thus, we applied Next-Generation DNA Sequencing to reveal the draft F. virguliforme genome sequence and identified putative pathogenicity genes to facilitate discovering the mechanisms used by the pathogen to cause this disease.
Methodology/Principal Findings
We have generated the draft genome sequence of F. virguliforme by conducting whole-genome shotgun sequencing on a 454 GS-FLX Titanium sequencer. Initially, single-end reads of a 400-bp shotgun library were assembled using the PCAP program. Paired end sequences from 3 and 20 Kb DNA fragments and approximately 100 Kb inserts of 1,400 BAC clones were used to generate the assembled genome. The assembled genome sequence was 51 Mb. The N50 scaffold number was 11 with an N50 Scaffold length of 1,263 Kb. The AUGUSTUS gene prediction program predicted 14,845 putative genes, which were annotated with Pfam and GO databases. Gene distributions were uniform in all but one of the major scaffolds. Phylogenic analyses revealed that F. virguliforme was closely related to the pea pathogen, Nectria haematococca. Of the 14,845 F. virguliforme genes, 11,043 were conserved among five Fusarium species: F. virguliforme, F. graminearum, F. verticillioides, F. oxysporum and N. haematococca; and 1,332 F. virguliforme-specific genes, which may include pathogenicity genes. Additionally, searches for candidate F. virguliforme pathogenicity genes using gene sequences of the pathogen-host interaction database identified 358 genes.Conclusions
The F. virguliforme genome sequence and putative pathogenicity genes presented here will facilitate identification of pathogenicity mechanisms involved in SDS development. Together, these resources will expedite our efforts towards discovering pathogenicity mechanisms in F. virguliforme. This will ultimately lead to improvement of SDS resistance in soybean. 相似文献209.
210.