76 research outputs found

    Presence of antigenic and specific heat shock protein(s) of shigella flexneri and shigella sonnei

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    Shigellosis caused by Shigella spp. is a public health concern in developing countries. Due to global emergence of drug resistance to Shigella spp., the choice of antimicrobial agents to treat shigellosis is limited. Current identification of this pathogen is by conventional culture method and biochemical tests, which takes about 2 to 7 days to produce result. Hence, there is a need for a rapid and reliable test that would allow rapid management of shigellosis infections. Development of a specific and sensitive diagnostic test requires discovery of biomarker(s), which does not cross react with other bacteria and are specific only to Shigella spp .Heat shock proteins (HSP) are proteins expressed in bacteria during stress environment and these proteins have potential as biomarker in diagnostic field. Thus the aim of this study is to detect the presence of HSPs and biomarker(s) in the outer membrane proteins (OMPs) of S. flexneri and S. sonnei. Protein profiles of OMPs from the ATCC strain and clinical isolate of S. flexneri and S. sonnei were demonstrated using the technique of Sodium Dodecyl Sulfate-Poly Acrylamide Gel Electrophoresis (SDS-PAGE). The OMPs profiles of S. flexneri and S. sonnei expressed at 37°C was compared with the profiles of 38.5°C and 40°C (temperature in patients with fever during shigellosis) to assess the effect of temperature on the expression of the OMPs. This study demonstrated that the expression level of OMPs of S. flexneri and S. sonnei varies with increasing temperatures. The protein electrophoretograms were subjected to Western blot using serum from patients infected with S. sonnei and S. flexneri as well other related infections. Result of this study demonstrated 11 antigenic bands were detected when probed with sera from patients with S. flexneri infection against both anti-human IgA and IgG isotypes. A total of 14 and 11 antigenic bands were obtained against anti-human IgA and IgG respectively when probed with sera from S. sonnei infection. All the antigenic bands were checked for cross reactivity using sera from patients infected with Salmonella spp., Enteropathogenic Escherichia coli, Salmonella Typhi, Aeromonas hydrophila and Campylobacter jejuni. Three protein bands (33.3, 43.8 and 100.3 kDa) of the S. sonnei and 2 protein bands (25.6 and 63.2 kDa) of the S. flexneri did not cross reacted with sera from other infections, suggesting that these proteins are specific biomarker for S. flexneri and S. sonnei. The identified HSPs showing prominent increased in expression were further identified by MALDI-ToF-ToF analysis. The HSPs of 18.4, 25.6 and 57.0 kDa in size from S. flexneri were identified as Dps, WrbA and PepA respectively. Whereas, the HSPs of 43.8 and 100.3 kDa in size from S. sonnei were identified as Pbp and AceE. The increased expression of these proteins probably is a mechanism of survival of the bacterium at higher temperatures in the host body and could be potential diagnostic biomarkers. Therefore these identified specific proteins for S. flexneri and S. sonnei can be used as biomarkers for development of diagnostic test which would allow rapid and accurate diagnosis of shigellosis to control the disease outbreak

    Perception of the Indian Working Women considering Equity as an Investment Avenue: An Empirical Study

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    This long-lasting volatility in the stock market since the global financial crisis has been disappointing issue for the retail investors to invest in equity markets. Due to high volatility, new clients are scared to burn their fingers and existing investors are uncomfortable in roiling their portfolios

    Expression of Snail2 in long bone osteosarcomas correlates with tumour malignancy

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    Snail2 is a marker of malignancy in epithelial tumours; however, in sarcomas, it is not known if this protein is present. Here we examine the expression of Snail2 in one type of sarcoma, osteosarcoma, and explore its relationship to tumour grade, subtype and anatomical location in cases of long bone and cranial bone osteosarcoma. Long bone osteosarcomas typically have a much greater metastatic capability and a poorer prognosis. We find that Snail2 is expressed in the three main subtypes of long bone osteosarcoma—osteoblastic, chondroblastic and fibroblastic. Regression analysis showed that Snail 2 expression was statistically correlated with tumour grade (p = 0.014) in all of these subtypes. Snail2 was only expressed in high-grade cranial bone osteosarcomas, suggesting a link between Snail2 expression and metastasis. This is the first time Snail2 has been associated with any sarcoma, and this study shows that Snail2 may be a useful prognostic marker for this disease

    The E-cadherin repressor slug and progression of human extrahepatic hilar cholangiocarcinoma

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    <p>Abstract</p> <p>Objectives</p> <p>This study explored the expression and function of Slug in human extrahepatic hilar cholangiocarcinoma (EHC) to identify its role in tumor progression.</p> <p>Methods</p> <p>The expression of Snail and Slug mRNA in 52 human tissue samples of EHC was investigated. The mRNA of Snail and Slug were quantified using reverse transcriptase-PCR, and correlations with E-cadherin expression and clinicopathological factors were investigated. We then investigated transfection of Slug cDNA in endogenous E-cadherin-positive human EHC FRH0201 cells, selectively induced the loss of E-cadherin protein expression, and then small interfering RNA (siRNA) for inhibition of Slug expression in endogenous Slug-positive human EHC QBC939 cells, selectively induced the loss of Slug protein expression. A Boyden chamber transwell assay was used for invasion.</p> <p>Results</p> <p>Slug mRNA was overexpressed in 18 cases (34.6%) of EHC compared with adjacent noncancerous tissue. E-Cadherin protein expression determined in the same 52 cases by immunohistochemistry was significantly down-regulated in those cases with Slug mRNA overexpression (P = 0.0001). The tumor and nontumor ratio of Slug mRNA was correlated with nodal metastasis(p = 0.0102), distant metastasis (p = 0.0001)and Survival time(p = 0.0443). However, Snail mRNA correlated with neither E-cadherin expression nor tumor invasiveness. By inhibiting Slug expression by RNA interference, we found that reduced Slug levels upregulated E-cadherin and decreased invasion in QBC939 cell. When the QBC939 cells was infected with Slug cDNA,, significant E-cadherin was downregulated and increased invasion in QBC939 cell.</p> <p>Conclusions</p> <p>The results suggested that Slug expression plays an important role in both the regulation of E-cadherin expression and in the acquisition of invasive potential in human EHC. Slug is possibly a potential target for an antitumor therapy blocking the functions of invasion and metastasis in human EHCs.</p

    Differential cell reaction upon Toll-like receptor 4 and 9 activation in human alveolar and lung interstitial macrophages

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    BACKGROUND: Investigations on pulmonary macrophages (M&#934;) mostly focus on alveolar M&#934; (AM) as a well-defined cell population. Characteristics of M&#934; in the interstitium, referred to as lung interstitial M&#934; (IM), are rather ill-defined. In this study we therefore aimed to elucidate differences between AM and IM obtained from human lung tissue. METHODS: Human AM and IM were isolated from human non-tumor lung tissue from patients undergoing lung resection. Cell morphology was visualized using either light, electron or confocal microscopy. Phagocytic activity was analyzed by flow cytometry as well as confocal microscopy. Surface marker expression was measured by flow cytometry. Toll-like receptor (TLR) expression patterns as well as cytokine expression upon TLR4 or TLR9 stimulation were assessed by real time RT-PCR and cytokine protein production was measured using a fluorescent bead-based immunoassay. RESULTS: IM were found to be smaller and morphologically more heterogeneous than AM, whereas phagocytic activity was similar in both cell types. HLA-DR expression was markedly higher in IM compared to AM. Although analysis of TLR expression profiles revealed no differences between the two cell populations, AM and IM clearly varied in cell reaction upon activation. Both M&#934; populations were markedly activated by LPS as well as DNA isolated from attenuated mycobacterial strains (M. bovis H37Ra and BCG). Whereas AM expressed higher amounts of inflammatory cytokines upon activation, IM were more efficient in producing immunoregulatory cytokines, such as IL10, IL1ra, and IL6.CONCLUSION: AM appear to be more effective as a non-specific first line of defence against inhaled pathogens, whereas IM show a more pronounced regulatory function. These dissimilarities should be taken into consideration in future studies on the role of human lung M&#934; in the inflammatory response

    The putative Tumor Suppressor VILIP-1 Counteracts Epidermal Growth Factor-Induced Epidermal-Mesenchymal Transition in Squamous Carcinoma Cells

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    Epithelial-mesenchymal transition (EMT) is a crucial step for the acquisition of invasive properties of carcinoma cells during tumor progression. Epidermal growth factor (EGF)-treatment of squamous cell carcinoma (SCC) cells provokes changes in the expression of lineage markers, morphological changes, and a higher invasive and metastatic potential. Here we show that chronic stimulation with EGF induces EMT in skin-derived SCC cell lines along with the down-regulation of the epithelial marker E-cadherin, and of the putative tumor suppressor VILIP-1 (visinin-like protein 1). In esophageal squamous cell carcinoma and non-small cell lung carcinoma the loss of VILIP-1 correlates with clinicopathological features related to enhanced invasiveness. VILIP-1 has previously been shown to suppress tumor cell invasion via enhancing cAMP-signaling in a murine SCC model. In mouse skin SCC cell lines the VILIP-1-negative tumor cells have low cAMP levels, whereas VILIP-1-positive SCCs possess high cAMP levels, but low invasive properties. We show that in VILIP-1-negative SCCs, Snail1, a transcriptional repressor involved in EMT, is up-regulated. Snail1 expression is reduced by ectopic VILIP-1-expression in VILIP-1-negative SCC cells, and application of the general adenylyl cyclase inhibitor 2′,3′-dideoxyadenosine attenuated this effect. Conversely, EGF-stimulation of VILIP-1-positive SCC cells leads to the down-regulation of VILIP-1 and the induction of Snail1 expression. The induction of Snail is inhibited by elevated cAMP levels. The role of cAMP in EMT was further highlighted by its suppressive effect on the EGF-induced enhancement of migration in VILIP-1-positive SCC cells. These findings indicate that VILIP-1 is involved in EMT of SCC by regulating the transcription factor Snail1 in a cAMP-dependent manner

    An NF-κB and Slug Regulatory Loop Active in Early Vertebrate Mesoderm

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    BACKGROUND: In both Drosophila and the mouse, the zinc finger transcription factor Snail is required for mesoderm formation; its vertebrate paralog Slug (Snai2) appears to be required for neural crest formation in the chick and the clawed frog Xenopus laevis. Both Slug and Snail act to induce epithelial to mesenchymal transition (EMT) and to suppress apoptosis. METHODOLOGY & PRINCIPLE FINDINGS: Morpholino-based loss of function studies indicate that Slug is required for the normal expression of both mesodermal and neural crest markers in X. laevis. Both phenotypes are rescued by injection of RNA encoding the anti-apoptotic protein Bcl-xL; Bcl-xL's effects are dependent upon IκB kinase-mediated activation of the bipartite transcription factor NF-κB. NF-κB, in turn, directly up-regulates levels of Slug and Snail RNAs. Slug indirectly up-regulates levels of RNAs encoding the NF-κB subunit proteins RelA, Rel2, and Rel3, and directly down-regulates levels of the pro-apopotic Caspase-9 RNA. CONCLUSIONS/SIGNIFICANCE: These studies reveal a Slug/Snail–NF-κB regulatory circuit, analogous to that present in the early Drosophila embryo, active during mesodermal formation in Xenopus. This is a regulatory interaction of significance both in development and in the course of inflammatory and metastatic disease

    HER-2 overexpression differentially alters transforming growth factor-β responses in luminal versus mesenchymal human breast cancer cells

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    INTRODUCTION: Amplification of the HER-2 receptor tyrosine kinase has been implicated in the pathogenesis and aggressive behavior of approximately 25% of invasive human breast cancers. Clinical and experimental evidence suggest that aberrant HER-2 signaling contributes to tumor initiation and disease progression. Transforming growth factor beta (TGF-β) is the dominant factor opposing growth stimulatory factors and early oncogene activation in many tissues, including the mammary gland. Thus, to better understand the mechanisms by which HER-2 overexpression promotes the early stages of breast cancer, we directly assayed the cellular and molecular effects of TGF-β1 on breast cancer cells in the presence or absence of overexpressed HER-2. METHODS: Cell proliferation assays were used to determine the effect of TGF-β on the growth of breast cancer cells with normal or high level expression of HER-2. Affymetrix microarrays combined with Northern and western blot analysis were used to monitor the transcriptional responses to exogenous TGF-β1 in luminal and mesenchymal-like breast cancer cells. The activity of the core TGF-β signaling pathway was assessed using TGF-β1 binding assays, phospho-specific Smad antibodies, immunofluorescent staining of Smad and Smad DNA binding assays. RESULTS: We demonstrate that cells engineered to over-express HER-2 are resistant to the anti-proliferative effect of TGF-β1. HER-2 overexpression profoundly diminishes the transcriptional responses induced by TGF-β in the luminal MCF-7 breast cancer cell line and prevents target gene induction by a novel mechanism that does not involve the abrogation of Smad nuclear accumulation, DNA binding or changes in c-myc repression. Conversely, HER-2 overexpression in the context of the mesenchymal MDA-MB-231 breast cell line potentiated the TGF-β induced pro-invasive and pro-metastatic gene signature. CONCLUSION: HER-2 overexpression promotes the growth and malignancy of mammary epithelial cells, in part, by conferring resistance to the growth inhibitory effects of TGF-β. In contrast, HER-2 and TGF-β signaling pathways can cooperate to promote especially aggressive disease behavior in the context of a highly invasive breast tumor model

    Household, community, sub-national and country-level predictors of primary cooking fuel switching in nine countries from the PURE study

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    Introduction. Switchingfrom polluting (e.g. wood, crop waste, coal)to clean (e.g. gas, electricity) cooking fuels can reduce household air pollution exposures and climate-forcing emissions.While studies have evaluated specific interventions and assessed fuel-switching in repeated cross-sectional surveys, the role of different multilevel factors in household fuel switching, outside of interventions and across diverse community settings, is not well understood. Methods.We examined longitudinal survey data from 24 172 households in 177 rural communities across nine countries within the Prospective Urban and Rural Epidemiology study.We assessed household-level primary cooking fuel switching during a median of 10 years offollow up (∼2005–2015).We used hierarchical logistic regression models to examine the relative importance of household, community, sub-national and national-level factors contributing to primary fuel switching. Results. One-half of study households(12 369)reported changing their primary cookingfuels between baseline andfollow up surveys. Of these, 61% (7582) switchedfrom polluting (wood, dung, agricultural waste, charcoal, coal, kerosene)to clean (gas, electricity)fuels, 26% (3109)switched between different polluting fuels, 10% (1164)switched from clean to polluting fuels and 3% (522)switched between different clean fuels

    Household, community, sub-national and country-level predictors of primary cooking fuel switching in nine countries from the PURE study

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