Larvicidal effect of Hemidesmus indicus, Gymnema sylvestre, and Eclipta prostrata,/i> against Culex qinquifaciatus mosquito larvae

The larvicidal effect of aqueous extracts of Hemidesmus indicus roots, Gymnema sylvestre and Eclipta prostrata leaves were tested against Culex quinquefasciatus larvae at the concentrations of 1, 2, 3, 4and 5% up to three days. All extracts showed larval mortality. Larval mortality was 100% with the use of 5% concentration of root extract of H. indicus, leaves extracts of G. sylvestre and E. prostrata after 2days. Qualitative analysis of the phytochemicals of aqueous extracts revealed the presence of carbohydrates, saponins, phytosterols, phenols, flavonoids and tannins in all the plants. Quantitative analysis showed that the crude saponin was the major phytochemical constituent present in highest percentage followed by crude tannin in all three plants. It is suggested that all the three plants possess larvicidal properties that could be developed and used as natural insecticides for mosquito control

The association between histamine 2 receptor antagonist use and Clostridium difficile infection: a systematic review and meta-analysis.

Background Clostridium difficile infection (CDI) is a major health problem. Epidemiological evidence suggests that there is an association between acid suppression therapy and development of CDI. Purpose We sought to systematically review the literature that examined the association between histamine 2 receptor antagonists (H2RAs) and CDI. Data source We searched Medline, Current Contents, Embase, ISI Web of Science and Elsevier Scopus from 1990 to 2012 for all analytical studies that examined the association between H2RAs and CDI. Study selection Two authors independently reviewed the studies for eligibility. Data extraction Data about studies characteristics, adjusted effect estimates and quality were extracted. Data synthesis Thirty-five observations from 33 eligible studies that included 201834 participants were analyzed. Studies were performed in 6 countries and nine of them were multicenter. Most studies did not specify the type or duration of H2RAs therapy. The pooled effect estimate was 1.44, 95% CI (1.22–1.7), I2 = 70.5%. This association was consistent across different subgroups (by study design and country) and there was no evidence of publication bias. The pooled effect estimate for high quality studies was 1.39 (1.15–1.68), I2 = 72.3%. Meta-regression analysis of 10 study-level variables did not identify sources of heterogeneity. In a speculative analysis, the number needed to harm (NNH) with H2RAs at 14 days after hospital admission in patients receiving antibiotics or not was 58, 95% CI (37, 115) and 425, 95% CI (267, 848), respectively. For the general population, the NNH at 1 year was 4549, 95% CI (2860, 9097). Conclusion In this rigorous systematic review and meta-analysis, we observed an association between H2RAs and CDI. The absolute risk of CDI associated with H2RAs is highest in hospitalized patients receiving antibiotics

Mosquito larvicidal activities of Solanum villosum berry extract against the dengue vector Stegomyia aegypti

<p>Abstract</p> <p>Background</p> <p>Vector control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. Although several plants have been reported for mosquitocidal activity, only a few botanicals have moved from the laboratory to field use, because they are poorly characterized, in most cases active principals are not determined and most of the works are restricted to preliminary screening. <it>Solanum villosum </it>is a common weed distributed in many parts of India with medicinal properties, but the larvicidal activity of this plant has not been reported so far.</p> <p>Methods</p> <p>Aqueous and polar/non-polar solvent extract of fresh, mature, green berries of <it>S. villosum </it>was tested against <it>Stegomyia aegypti</it>, a common vector of dengue fever. A phytochemical analysis of chloroform:methanol extract was performed to search for the active toxic ingredient. The lethal concentration was determined (log probit analysis) and compared with Malathion. The chemical nature of the active substance was also evaluated following ultraviolet-visual (UV-Vis) and infrared (IR) analysis.</p> <p>Results</p> <p>In a 72 hour bioassay experiment with the aqueous extract, the highest mortality was recorded in 0.5% extract. When the mortality of different solvent extracts was compared, the maximum (<it>p </it>< 0.05) mortality was recorded at a concentration of 50 ppm of chloroform:methanol extract (1:1, v/v). The larvicidal activity was lower when compared with the chemical insecticide, Malathion (<it>p </it>< 0.05). Results of regression analysis revealed that the mortality rate (<it>Y</it>) was positively correlated with the period of exposure (<it>X</it>) and the log probit analysis (95% confidence level) recorded lowest value (5.97 ppm) at 72 hours of exposure. Phytochemical analysis of the chlororm:methanol extract reported the presence of many bioactive phytochemicals. Two toxic compounds were detected having <it>R</it>_f= 0.82 (70% and 73.33% mortality in 24 and 48 hours, respectively) and <it>R</it>_f= 0.95 (40% and 50% mortality in 24 and 48 hours, respectively). IR analysis provided preliminary information about the steroidal nature of the active ingredient.</p> <p>Conclusion</p> <p><it>S. villosum </it>offers promise as potential bio control agent against <it>S. aegypti </it>particularly in its markedly larvicidal effect. The extract or isolated bioactive phytochemical could be used in stagnant water bodies for the control of mosquitoes acting as vector for many communicable diseases.</p

Adenoviral-mediated correction of methylmalonyl-CoA mutase deficiency in murine fibroblasts and human hepatocytes

<p>Abstract</p> <p>Background</p> <p>Methylmalonic acidemia (MMA), a common organic aciduria, is caused by deficiency of the mitochondrial localized, 5'deoxyadenosylcobalamin dependent enzyme, methylmalonyl-CoA mutase (MUT). Liver transplantation in the absence of gross hepatic dysfunction provides supportive therapy and metabolic stability in severely affected patients, which invites the concept of using cell and gene delivery as future treatments for this condition.</p> <p>Methods</p> <p>To assess the effectiveness of gene delivery to restore the defective metabolism in this disorder, adenoviral correction experiments were performed using murine <it>Mut </it>embryonic fibroblasts and primary human methylmalonyl-CoA mutase deficient hepatocytes derived from a patient who harbored two early truncating mutations, E224X and R228X, in the <it>MUT </it>gene. Enzymatic and expression studies were used to assess the extent of functional correction.</p> <p>Results</p> <p>Primary hepatocytes, isolated from the native liver after removal subsequent to a combined liver-kidney transplantation procedure, or <it>Mut </it>murine fibroblasts were infected with a second generation recombinant adenoviral vector that expressed the murine methylmalonyl-CoA mutase as well as eGFP from distinct promoters. After transduction, [1-¹⁴C] propionate macromolecular incorporation studies and Western analysis demonstrated complete correction of the enzymatic defect in both cell types. Viral reconstitution of enzymatic expression in the human methylmalonyl-CoA mutase deficient hepatocytes exceeded that seen in fibroblasts or control hepatocytes.</p> <p>Conclusion</p> <p>These experiments provide proof of principle for viral correction in methylmalonic acidemia and suggest that hepatocyte-directed gene delivery will be an effective therapeutic treatment strategy in both murine models and in human patients. Primary hepatocytes from a liver that was unsuitable for transplantation provided an important resource for these studies.</p

Nf2/Merlin: a coordinator of receptor signalling and intercellular contact

This review explores possible mechanisms by which the neurofibromatosis type-2 tumour suppressor Merlin regulates contact-dependent inhibition of proliferation. Starting from an evolutionary perspective, the concurrent emergence of intercellular contacts and proliferation control in multicellular organisms is first considered. Following a brief survey of the molecular and subcellular milieus in which merlin performs its function, the importance of different cellular and biological contexts in defining the function of merlin is discussed. Finally, an integrated model for merlin and the Ezrin, Radixin, and Moesin (ERM) proteins functioning in the regulation of cellular interfaces is proposed

Separation of Recombination and SOS Response in Escherichia coli RecA Suggests LexA Interaction Sites

RecA plays a key role in homologous recombination, the induction of the DNA damage response through LexA cleavage and the activity of error-prone polymerase in Escherichia coli. RecA interacts with multiple partners to achieve this pleiotropic role, but the structural location and sequence determinants involved in these multiple interactions remain mostly unknown. Here, in a first application to prokaryotes, Evolutionary Trace (ET) analysis identifies clusters of evolutionarily important surface amino acids involved in RecA functions. Some of these clusters match the known ATP binding, DNA binding, and RecA-RecA homo-dimerization sites, but others are novel. Mutation analysis at these sites disrupted either recombination or LexA cleavage. This highlights distinct functional sites specific for recombination and DNA damage response induction. Finally, our analysis reveals a composite site for LexA binding and cleavage, which is formed only on the active RecA filament. These new sites can provide new drug targets to modulate one or more RecA functions, with the potential to address the problem of evolution of antibiotic resistance at its root

Sourcing Technological Knowledge Through Foreign Inward Licensing to Boost the Performance of Indian Firms: The Contingent Effects of Internal R&D and Business Group Affiliation

Sourcing technological knowledge from abroad is becoming a popular strategy among emerging market firms (EMFs). Combining the Knowledge-Based View and the Resource Dependence Theory, we argue that augmenting technological knowledge through foreign licensing enables EMFs to access state-of-the-art technological knowledge, reduce operational costs and risks associated to the innovation process, and develop a knowledge-based competitive advantage, ultimately boosting their financial performance. Using data about Indian firms observed from 2001 to 2013, we find that firms with a higher share of foreign inward technology licenses report better financial performance. However, the positive impact of technological knowledge accessed through inward licensing on firm performance is contingent upon: (1) the internal knowledge developed through R&D activity, and (2) the affiliation with business groups. While Indian firms with higher level of internal R&D are able to better leverage the value of foreign technological knowledge, thus reaching higher performance, firms affiliated to business groups gain fewer benefits from licensed foreign technological knowledge than non-business-group affiliated firms

WSES guidelines for management of Clostridium difficile infection in surgical patients

In the last two decades there have been dramatic changes in the epidemiology of Clostridium difficile infection (CDI), with increases in incidence and severity of disease in many countries worldwide. The incidence of CDI has also increased in surgical patients. Optimization of management of C difficile, has therefore become increasingly urgent. An international multidisciplinary panel of experts prepared evidenced-based World Society of Emergency Surgery (WSES) guidelines for management of CDI in surgical patients.Peer reviewe