167 research outputs found

    Toxic effects of chromium on the aquatic cyanobacterium Oscillatoria sp and removal of chromium by biosorption

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    “Chromium” is a non-essential metal for microorganisms and plants and a serious pollutant in diverse environment conditions. The hexavalent form of the metal Cr (IV) is considered to be more toxic than relatively harmless Cr(III) form. Certain microorganisms in the environment are able to tolerate high levels of Cr due to their resistance mechanism. In the present work we report the toxic effect of chromium on Oscillatoria sp and the removal of hexavalent using the cyanobacterium Oscillatoria sp., by biosorption method. Oscillatoria sp., was grown in BG-11 medium containing different concentration of Cr. Effect of Cr on cellular metabolism was studied by estimating the amount of chlorophyll a, carotenoids,  c. phycocyanin, allophycocyanin, sugars, free amino acids and proteins at various metal concentration. An increase in metal concentration caused a decrease in the growth of the Oscillatoria sp., and also decreased the cellular contents like chlorophyll a, carotenoids, c.phycocyanin, allophycocyanin, sugars, free amino acids and proteins. Biosorption of chromium by Oscillatoria sp., was carried out using living cells, heat killed cells and pre-treated cells. Results showed that high amount of metal were adsorbed by heat killed and living cells of Oscillatoria sp. The experimental conditions used in the present work are simple and have low operational cost. The proposed biosorption method is economically feasible and eco-friendly in nature

    Seaweed extract as a biostimulant for legume crop, green gram

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    The aim of this research is to investigate the effect of seaweed extracts obtained from the marine green algae, Ulva lactuca Linnaeus, Caulerpa scalpelliformis (R. Brown ex Turner) C. Agardh, brown algae Sargassum plagiophyllum C. Agardh, Turbinaria conoides (J. Agardh) Kutzing, Padina tetrastromatica Hauck, Dictyota dichotama (Hudson) J. V. Lamouroux on the stimulate germination, growth parameters of the Vigna radiata. The present study reveals the seeds germination, fresh weight and dry weight of shoots and roots. These results suggested that seaweed extracts stronger induce seed germination and growth parameters

    Prevalence and genotype distribution of human papilloma virus in cervical samples of young married women: a hospital based prospective cross-sectional study

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    Background: The aim of the study was to determine the prevalence and genotypes of human papillomavirus (HPV) infection in the cervical samples of young married women at a tertiary care hospital in Chhattisgarh. A prospective cross-sectional observational study was performed in married women, aged 18 to 30 years.Methods: Relevant history was noted and cervical samples were collected and tested for HPV deoxyribonucleic acid (DNA) by polymerase chain reaction (PCR). Data was compiled to calculate the prevalence of HPV and the genotypic distribution.Results: The overall prevalence of HPV in this study was 22.73% and that of type 16 and 18 either alone or in combination with other subtypes was 17.26%. They were the commonest subtypes. HPV positivity was inversely related to education levels (Chi square, p=0.05). There was a significant difference in parity of women testing positive for HPV versus those negative for HPV (one tailed Pr (t<t)=0.03, 95% CI=1.445 to 1,865 at 108 degrees of freedom). No difference was observed between education and socio economic levels of positive versus negative women. Type 16 and 18 accounted for 76% of all HPV subtypes detected.Conclusions: The prevalence of HPV infection is high in Indian women. The high risk oncogenic types are the commonest subtypes. There is an urgent need to screen for the presence of high risk HPV infections in younger women so that they may be followed up more closely to prevent cervical cancers

    Sodium-coupled Monocarboxylate Transporters in Normal Tissues and in Cancer

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    SLC5A8 and SLC5A12 are sodium-coupled monocarboxylate transporters (SMCTs), the former being a high-affinity type and the latter a low-affinity type. Both transport a variety of monocarboxylates in a Na+-coupled manner. They are expressed in the gastrointestinal tract, kidney, thyroid, brain, and retina. SLC5A8 is localized to the apical membrane of epithelial cells lining the intestinal tract and proximal tubule. In the brain and retina, its expression is restricted to neurons and the retinal pigment epithelium. The physiologic functions of SLC5A8 include absorption of short-chain fatty acids in the colon and small intestine, reabsorption of lactate and pyruvate in the kidney, and cellular uptake of lactate and ketone bodies in neurons. It also transports the B-complex vitamin nicotinate. SLC5A12 is also localized to the apical membrane of epithelial cells lining the intestinal tract and proximal tubule. In the brain and retina, its expression is restricted to astrocytes and MΓΌller cells. SLC5A8 also functions as a tumor suppressor; its expression is silenced in tumors of colon, thyroid, stomach, kidney, and brain. The tumor-suppressive function is related to its ability to mediate concentrative uptake of butyrate, propionate, and pyruvate, all of which are inhibitors of histone deacetylases. SLC5A8 can also transport a variety of pharmacologically relevant monocarboxylates, including salicylates, benzoate, and Ξ³-hydroxybutyrate. Non-steroidal anti-inflammatory drugs such as ibuprofen, ketoprofen, and fenoprofen, also interact with SLC5A8. These drugs are not transportable substrates for SLC5A8, but instead function as blockers of the transporter. Relatively less is known on the role of SLC5A12 in drug transport

    The Cebpd (C/EBPΞ΄) Gene Is Induced by Luteinizing Hormones in Ovarian Theca and Interstitial Cells But Is Not Essential for Mouse Ovary Function

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    The CCAAT/enhancer binding protein (CEBP) family of transcription factors includes five genes. In the ovary, both Cebpa and Cebpb are essential for granulosa cell function. In this study we have explored the role of the Cebpd gene in ovarian physiology by expression and functional studies. Here we report that Cebpd (C/EBPΞ΄) is expressed in the mouse ovary in a highly restricted temporal and spatial pattern. In response to luteinizing hormone (LH/hCG), CEBPD expression is transiently induced in interstitial cells and in theca cells of follicles from the primary to pre-ovulatory stage, and overlaps in part with expression of the alpha-smooth muscle actin protein. Efficient down-regulation of CEBPD was dependent on a functional Cebpb gene. Proliferating human theca cells in culture also express Cebpd. Cells from patients with polycystic ovarian syndrome (PCOS) exhibited higher Cebpd expression levels. However, deletion of Cebpd in mice had no overt effect on ovarian physiology and reproductive function. Very little is known at present about the molecular mechanisms underlying theca/interstitial cell functions. The expression pattern of CEBPD reported here identifies a novel functional unit of mouse theca cells of primary through tertiary follicles responding to LH/hCG together with a subset of interstitial cells. This acute stimulation of CEBPD expression may be exploited to further characterize the hormonal regulation and function of theca and interstitial cells

    The effects of aromatase inhibitors on lipids and thrombosis

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    Oestrogen is known to influence blood lipid levels and though its cardioprotective effects are less clear than once thought, there remains concern that reduction of oestrogen levels during hormonal treatment for breast cancer may have an adverse effect on cardiovascular risk. While tamoxifen has been shown to improve lipid profiles, the aromatase inhibitors have a very different mode of action and do not possess the oestrogen-agonistic effects of tamoxifen. At present, there are few data on the effects of these agents on lipid profiles. Available data are mixed, but suggest that the different aromatase inhibitors have different effects on lipid profiles. Some studies show anastrozole as generally having little effect on lipids, while others have indicated adverse effects on lipid profiles/increased hypercholesterolaemia. Letrozole has been associated with adverse effects on lipid profiles in some studies, including BIG 1-98, but short-term data from randomised trials do not show increased cardiovascular morbidity. By contrast, exemestane, which has been studied in slightly more detail, may either have little effect or may be associated with slightly improved lipid profiles. In general, the changes have been small and are likely to be of little relevance in women with advanced breast cancer, but if these agents come to be used in early breast cancer, their impact on lipid profiles may become more important. Many studies are currently underway with the aromatase inhibitors, with safety assessments including monitoring lipid levels. The results of these studies are keenly awaited

    An integrative approach to identifying cancer chemoresistance-associated pathways

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    <p>Abstract</p> <p>Background</p> <p>Resistance to chemotherapy severely limits the effectiveness of chemotherapy drugs in treating cancer. Still, the mechanisms and critical pathways that contribute to chemotherapy resistance are relatively unknown. This study elucidates the chemoresistance-associated pathways retrieved from the integrated biological interaction networks and identifies signature genes relevant for chemotherapy resistance.</p> <p>Methods</p> <p>An integrated network was constructed by collecting multiple metabolic interactions from public databases and the k-shortest path algorithm was implemented to identify chemoresistant related pathways. The identified pathways were then scored using differential expression values from microarray data in chemosensitive and chemoresistant ovarian and lung cancers. Finally, another pathway database, Reactome, was used to evaluate the significance of genes within each filtered pathway based on topological characteristics.</p> <p>Results</p> <p>By this method, we discovered pathways specific to chemoresistance. Many of these pathways were consistent with or supported by known involvement in chemotherapy. Experimental results also indicated that integration of pathway structure information with gene differential expression analysis can identify dissimilar modes of gene reactions between chemosensitivity and chemoresistance. Several identified pathways can increase the development of chemotherapeutic resistance and the predicted signature genes are involved in drug resistant during chemotherapy. In particular, we observed that some genes were key factors for joining two or more metabolic pathways and passing down signals, which may be potential key targets for treatment.</p> <p>Conclusions</p> <p>This study is expected to identify targets for chemoresistant issues and highlights the interconnectivity of chemoresistant mechanisms. The experimental results not only offer insights into the mode of biological action of drug resistance but also provide information on potential key targets (new biological hypothesis) for further drug-development efforts.</p

    Lineage-Specific Restraint of Pituitary Gonadotroph Cell Adenoma Growth

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    Although pituitary adenomas are usually benign, unique trophic mechanisms restraining cell proliferation are unclear. As GH-secreting adenomas are associated with p53/p21-dependent senescence, we tested mechanisms constraining non-functioning pituitary adenoma growth. Thirty six gonadotroph-derived non-functioning pituitary adenomas all exhibited DNA damage, but undetectable p21 expression. However, these adenomas all expressed p16, and >90% abundantly expressed cytoplasmic clusterin associated with induction of the Cdk inhibitor p15 in 70% of gonadotroph and in 26% of somatotroph lineage adenomas (pβ€Š=β€Š0.006). Murine LΞ²T2 and Ξ±T3 gonadotroph pituitary cells, and Ξ±GSU.PTTG transgenic mice with targeted gonadotroph cell adenomas also abundantly expressed clusterin and exhibited features of oncogene-induced senescence as evidenced by C/EBPΞ² and C/EBPΞ΄ induction. In turn, C/EBPs activated the clusterin promoter ∼5 fold, and elevated clusterin subsequently elicited p15 and p16 expression, acting to arrest murine gonadotroph cell proliferation. In contrast, specific clusterin suppression by RNAis enhanced gonadotroph proliferation. FOXL2, a tissue-specific gonadotroph lineage factor, also induced the clusterin promoter ∼3 fold in Ξ±T3 pituitary cells. As nine of 12 pituitary carcinomas were devoid of clusterin expression, this protein may limit proliferation of benign adenomatous pituitary cells. These results point to lineage-specific pathways restricting uncontrolled murine and human pituitary gonadotroph adenoma cell growth
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