46 research outputs found

    The ISWI Chromatin Remodeler Organizes the hsrω ncRNA–Containing Omega Speckle Nuclear Compartments

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    The complexity in composition and function of the eukaryotic nucleus is achieved through its organization in specialized nuclear compartments. The Drosophila chromatin remodeling ATPase ISWI plays evolutionarily conserved roles in chromatin organization. Interestingly, ISWI genetically interacts with the hsrω gene, encoding multiple non-coding RNAs (ncRNA) essential, among other functions, for the assembly and organization of the omega speckles. The nucleoplasmic omega speckles play important functions in RNA metabolism, in normal and stressed cells, by regulating availability of hnRNPs and some other RNA processing proteins. Chromatin remodelers, as well as nuclear speckles and their associated ncRNAs, are emerging as important components of gene regulatory networks, although their functional connections have remained poorly defined. Here we provide multiple lines of evidence showing that the hsrω ncRNA interacts in vivo and in vitro with ISWI, regulating its ATPase activity. Remarkably, we found that the organization of nucleoplasmic omega speckles depends on ISWI function. Our findings highlight a novel role for chromatin remodelers in organization of nucleoplasmic compartments, providing the first example of interaction between an ATP-dependent chromatin remodeler and a large ncRNA

    Axillary lymph node dissection for breast cancer utilizing Harmonic Focus®

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    <p>Abstract</p> <p>Background</p> <p>For patients with axillary lymph node metastases from breast cancer, performance of a complete axillary lymph node dissection (ALND) is the standard approach. Due to the rich lymphatic network in the axilla, it is necessary to carefully dissect and identify all lymphatic channels. Traditionally, these lymphatics are sealed with titanium clips or individually sutured. Recently, the Harmonic Focus<sup>®</sup>, a hand-held ultrasonic dissector, allows lymphatics to be sealed without the utilization of clips or ties. We hypothesize that ALND performed with the Harmonic Focus<sup>® </sup>will decrease operative time and reduce post-operative complications.</p> <p>Methods</p> <p>Retrospective review identified all patients who underwent ALND at a teaching hospital between January of 2005 and December of 2009. Patient demographics, presenting pathology, treatment course, operative time, days to drain removal, and surgical complications were recorded. Comparisons were made to a selected control group of patients who underwent similar surgical procedures along with an ALND performed utilizing hemostatic clips and electrocautery. A total of 41 patients were included in this study.</p> <p>Results</p> <p>Operative time was not improved with the use of ultrasonic dissection, however, there was a decrease in the total number of days that closed suction drainage was required, although this was not statistically significant. Complication rates were similar between the two groups.</p> <p>Conclusion</p> <p>In this case-matched retrospective review, there were fewer required days of closed suction drainage when ALND was performed with ultrasonic dissection versus clips and electrocautery.</p

    Network Compression as a Quality Measure for Protein Interaction Networks

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    With the advent of large-scale protein interaction studies, there is much debate about data quality. Can different noise levels in the measurements be assessed by analyzing network structure? Because proteomic regulation is inherently co-operative, modular and redundant, it is inherently compressible when represented as a network. Here we propose that network compression can be used to compare false positive and false negative noise levels in protein interaction networks. We validate this hypothesis by first confirming the detrimental effect of false positives and false negatives. Second, we show that gold standard networks are more compressible. Third, we show that compressibility correlates with co-expression, co-localization, and shared function. Fourth, we also observe correlation with better protein tagging methods, physiological expression in contrast to over-expression of tagged proteins, and smart pooling approaches for yeast two-hybrid screens. Overall, this new measure is a proxy for both sensitivity and specificity and gives complementary information to standard measures such as average degree and clustering coefficients

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Hepatic microsomal bile acid biotransformation : identification of metabolites and cytochrome p450 enzymes involved

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    Bile acids are end-products of cholesterol metabolism and essential for absorption of dietary lipids in the body. Impaired bile flow leads to hepatic bile acid accumulation and liver damage. Hepatic microsomal oxidation offers a potential mechanism for efficient elimination of bile acids. The present study investigated the cytochrome P450 (P450)-mediated hepatic microsomal biotransformation profiles of lithocholic acid, cholic acid and chenodeoxycholic acid using a liquid chromatography-mass spectrometry (LCIMS) based assay. Incubation of lithocholic acid with rat hepatic microsomes resulted in the formation of a major 6β-hydroxylated metabolite, murideoxycholic acid, followed by isolithocholic acid and 3-ketocholanoic acid. Ursodeoxycholic acid, hyodeoxycholic acid and 6-ketolithocholic acid were identified as minor metabolites. Studies using P450-specific antibodies, chemical inducers, and rat recombinant enzymes showed that formation of murideoxycholic acid and 3-ketocholanoic acid were mediated by CYP3A2 and CYP2C 11. Similar metabolite profiles were obtained by incubation of lithocholic acid with mouse hepatic microsomes generating murideoxycholic acid as the major metabolite. Studies using P450 inducers and chemical inhibitors suggested the involvement of murine CYP3A in murideoxycholic acid and 3-ketocholanoic acid formation, and CYP1A, CYP2B and CYP3A enzymes in ursodeoxycholic acid, hyodeoxycholic acid and 6-ketolithocholic acid formation by mouse liver microsomes. Biotransformation of lithocholic acid by human hepatic microsomes generated 3-ketocholanoic acid as the major metabolite, and hyodeoxycholic acid, ursodeoxycholic acid, 6-ketolithocholic acid and murideoxycholic acid, as minor metabolites. Studies with chemical inhibitors and human recombinant enzymes demonstrated that CYP3A4 catalyzed the formation of all five metabolites. The biotransformation of cholic acid and chenodeoxycholic acid by human hepatic microsomes revealed the formation of a single cholic acid metabolite, 3-dehydrocholic acid. Chenodeoxycholic acid biotransformation generated 7α-hydroxy-3 -oxo-5β-cholan-24-oic acid as the major metabolite followed by у-muricholic acid, 7-ketolithocholic acid and cholic acid, respectively. CYP3A4 was found to be the major enzyme involved in the biotransformation of cholic acid and chenodeoxycholic acid in human liver microsomes. A comparison of metabolite profiles demonstrated the dominant role of human CYP3A4 in the oxidation of bile acids at the C-3 position. In contrast, 6β-hydroxylation catalyzed by multiple P450 (CYP1A, CYP2B, CYP2C and CYP3A) enzymes was the preferred biotransformation pathway in rodent liver microsomes.Pharmaceutical Sciences, Faculty ofGraduat

    Hepatic biotransformation of lithocholic acid : role of cytochrome P450 enzymes

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    The purpose of the present study was to investigate the in vitro biotransformation of lithocholic acid (3α-hydroxy-5β-cholanoic acid, LCA). A validated and optimized method to analyze metabolite formation was developed using liquid chromatography-electrospray mass spectrometry (LC/MS). LCA (0.5-300 μM) was incubated with 0.5 mg/ml of hepatic microsomal protein (untreated male Wistar rats) for 30 min in a reaction mixture consisting of 1 mM NADPH and 46.5 mM potassium phosphate buffer at pH 7.4. LCA metabolites were resolved using a LC/MS and XTerra™ MS C₁₈ (2.1 mm ∗ 150 mm, 3.5 mm) column. The major metabolites were murideoxycholic acid (MDCA), isolithocholic acid (ILCA), and 3-ketocholanic acid (3KCA). Minor metabolites were β-muricholic acid (β-MCA), 6-ketolithocholic acid (6KLCA) and ursodeoxycholic acid (UDCA) and also included, M-1 to M-5, which were not identified. Recovery of all metabolite standards, except for 3KCA (60%), was between 80-100%. Metabolite formation was not observed in the absence of NADPH, with boiled microsomes, or following carbon monoxide treatment. Formation of MDCA, ILCA, UDCA and 6KLCA followed typical Michaelis-Menten kinetics. To identify the cytochrome P450 (CYP) enzymes involved in the formation of LCA metabolites, hepatic microsomes prepared from rats (Long Evans) treated with inducers including 3-methylcholanthrene (MC, 25 mg/kg bw/day ∗ 4 days), phenobarbital (PB, 75 mg/kg bw/day ∗ 4 days) and dexamethasone (DEX, 100 mg/kg bw/day x 4 days) were used. Formation of MDCA and ILCA was decreased with all three inducer treatments and formation of 3KCA was increased with DEX treatment suggesting that CYP3A is involved in formation of 3KCA, and non-inducible CYP enzymes catalyze formation of MDCA and ILCA. Metabolite formation was greater with male than female rat liver microsomes. Rabbit polyspecific anti-rat CYP2C IgG inhibited MDCA formation by 50% and polyspecific anti-rat CYP3A IgG inhibited 3KCA formation by 50%. Anti-rat CYP3A IgG inhibited MDCA, ILCA and 6KLCA formation partially, but inhibited M-1 and M-3 formation completely. Monospecific anti-rat CYP2C11 IgG was not effective in inhibiting the formation of any metabolites. In summary, the results demonstrate the involvement of CYP2C and CYP3A enzymes in rat hepatic LCA biotransformation.Pharmaceutical Sciences, Faculty ofGraduat

    Anti obesity mechanism of Curcuma longa L.: An Over view

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    Chronic low grade inflammation is one important reason for the development of obesity and the inflammation is initiated by excess nutrient from metabolic cell and is characterized by increasing TNFα, interlukins, cytokinines, etc. Besides this, genetic, social, behavioural and environmental factors alone or interaction with each other influences diet, physical activity by affecting complex hypothalamic neuro-circuitry. These increase leptin level, inflammatory mediators and reactive oxygen species (ROS), which positively correlate with obesity. Curcuma longa L., commonly known as Haridra have been used for treatment of obesity and diabetes since ancient time in Ayurveda, the Indian traditional system of medicine. From current research, it has been observed that C. longa inhibit secretion of leptin, pro-inflammatory mediators and over production of ROS, whereas it increases secretion of insulin, adiponectin in plasma. Increased serum adiponectin insulin and decreased production of ROS negatively correlate with obesity. In addition to these, C. longa inhibit early growth response (Egr-1) gene, which is related to development of obesity. It is clear that by affecting leptin, adiponectin, inflammatory mediators, ROS, regulating nutritional environment and Egr-1 gene, lipogenic gene and ob gene, C. longa may be affirmative for management of obesity

    <span style="font-size:15.0pt;font-family: "Times New Roman","serif";mso-fareast-font-family:"Times New Roman";color:black; mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:HI" lang="EN-US">Anti-obesity mechanism of <i>Curcuma longa</i><span style="mso-bidi-font-style:italic"> L. - An over view</span></span>

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    99-106Chronic low grade inflammation is one important reason for the development of obesity and the inflammation is initiated by excess nutrient from metabolic cell and is characterized by increasing TNFα, interlukins, cytokinines, etc. Besides this, genetic, social, behavioural and environmental factors alone or interaction with each other influences diet, physical activity by affecting complex hypothalamic neuro-circuitry. These increase leptin level, inflammatory mediators and reactive oxygen species (ROS), which positively correlate with obesity. Curcuma longa L., commonly known as Haridra have been used for treatment of obesity and diabetes since ancient time in Ayurveda<span style="mso-bidi-font-style: italic">, the Indian traditional system of medicine. From current research, it has been observed that <i style="mso-bidi-font-style: normal">C. longa inhibit secretion of leptin, pro-inflammatory mediators and over production of ROS, whereas it increases secretion of insulin, <span style="background:white;mso-bidi-font-weight: bold" lang="EN-GB">adiponectin in plasma. Increased serum <span style="background:white; mso-bidi-font-weight:bold" lang="EN-GB">adiponectin<span style="mso-ansi-language: EN-US" lang="EN-US"> insulin and decreased production of ROS negatively correlate with obesity. In addition to these, C. longa inhibit early growth response (Egr-1) gene, which is related to development of obesity. It is clear that by affecting leptin,<span style="background:white;mso-bidi-font-weight: bold"> adiponectin, inflammatory mediators, ROS, regulating nutritional environment and Egr-1 gene, lipogenic gene and ob gene, <i style="mso-bidi-font-style: normal">C. longa may be affirmative for management of obesity. </span
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