95 research outputs found

    Mycobacterium tuberculosis DosR Regulon Gene Rv0079 Encodes a Putative, ‘Dormancy Associated Translation Inhibitor (DATIN)’

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    Mycobacterium tuberculosis is a major human pathogen that has evolved survival mechanisms to persist in an immune-competent host under a dormant condition. The regulation of M. tuberculosis metabolism during latent infection is not clearly known. The dormancy survival regulon (DosR regulon) is chiefly responsible for encoding dormancy related functions of M. tuberculosis. We describe functional characterization of an important gene of DosR regulon, Rv0079, which appears to be involved in the regulation of translation through the interaction of its product with bacterial ribosomal subunits. The protein encoded by Rv0079, possibly, has an inhibitory role with respect to protein synthesis, as revealed by our experiments. We performed computational modelling and docking simulation studies involving the protein encoded by Rv0079 followed by in vitro translation and growth curve analysis experiments, involving recombinant E. coli and Bacille Calmette Guérin (BCG) strains that overexpressed Rv0079. Our observations concerning the interaction of the protein with the ribosomes are supportive of its role in regulation/inhibition of translation. We propose that the protein encoded by locus Rv0079 is a ‘dormancy associated translation inhibitor’ or DATIN

    Identification of Mannose Interacting Residues Using Local Composition

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    BACKGROUND: Mannose binding proteins (MBPs) play a vital role in several biological functions such as defense mechanisms. These proteins bind to mannose on the surface of a wide range of pathogens and help in eliminating these pathogens from our body. Thus, it is important to identify mannose interacting residues (MIRs) in order to understand mechanism of recognition of pathogens by MBPs. RESULTS: This paper describes modules developed for predicting MIRs in a protein. Support vector machine (SVM) based models have been developed on 120 mannose binding protein chains, where no two chains have more than 25% sequence similarity. SVM models were developed on two types of datasets: 1) main dataset consists of 1029 mannose interacting and 1029 non-interacting residues, 2) realistic dataset consists of 1029 mannose interacting and 10320 non-interacting residues. In this study, firstly, we developed standard modules using binary and PSSM profile of patterns and got maximum MCC around 0.32. Secondly, we developed SVM modules using composition profile of patterns and achieved maximum MCC around 0.74 with accuracy 86.64% on main dataset. Thirdly, we developed a model on a realistic dataset and achieved maximum MCC of 0.62 with accuracy 93.08%. Based on this study, a standalone program and web server have been developed for predicting mannose interacting residues in proteins (http://www.imtech.res.in/raghava/premier/). CONCLUSIONS: Compositional analysis of mannose interacting and non-interacting residues shows that certain types of residues are preferred in mannose interaction. It was also observed that residues around mannose interacting residues have a preference for certain types of residues. Composition of patterns/peptide/segment has been used for predicting MIRs and achieved reasonable high accuracy. It is possible that this novel strategy may be effective to predict other types of interacting residues. This study will be useful in annotating the function of protein as well as in understanding the role of mannose in the immune system

    Purification and Characterization of a Sperm Motility Inhibiting Factor from Caprine Epididymal Plasma

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    Several studies have been reported on the occurrence of sperm motility inhibiting factors in the male reproductive fluids of different mammalian species, but these proteins have not been adequately purified and characterized. A novel sperm motility inhibiting factor (MIF-II) has been purified from caprine epididymal plasma (EP) by Hydroxylapatite gel adsorption chromatography, DEAE-Cellulose ion-exchange chromatography and chromatofocusing. The MIF-II has been purified to apparent homogeneity and the molecular weight estimated by Sephacryl S-300 gel filtration is 160 kDa. MIF-II is a dimeric protein, made up of two subunits each having a molecular mass of 80 kDa as shown by SDS-PAGE. The isoelectric point of MIF-II is 5.1 as determined by chromatofocusing and isoelectric focusing. It is a heat labile protein and maximal active at the pH 6.9 to 7.5. The sperm motility inhibiting protein factor at 2 µg/ml (12.5 nM) level showed maximal motility-inhibiting activity. The observation that the epididymal plasma factor lowered the intracellular cAMP level of spermatozoa in a concentration-dependent manner suggests that it may block the motility of caprine cauda spermatozoa by interfering the cAMP dependent motility function. The results revealed that the purified protein factor has the potential of sperm motility inhibition and may serve as a vaginal contraceptive. The antibody raised against the MIF-II has the potential for enhancement of forward motility of cauda-spermatozoa. This antibody may thus be useful for solving some of the problems of male infertility due to low sperm motility

    Health state utilities associated with attributes of treatments for hepatitis C

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    BACKGROUND: Cost-utility analyses are frequently conducted to compare treatments for hepatitis C, which are often associated with complex regimens and serious adverse events. Thus, the purpose of this study was to estimate the utility associated with treatment administration and adverse events of hepatitis C treatments. DESIGN: Health states were drafted based on literature review and clinician interviews. General population participants in the UK valued the health states in time trade-off (TTO) interviews with 10- and 1-year time horizons. The 14 health states described hepatitis C with variations in treatment regimen and adverse events. RESULTS: A total of 182 participants completed interviews (50 % female; mean age = 39.3 years). Utilities for health states describing treatment regimens without injections ranged from 0.80 (1 tablet) to 0.79 (7 tablets). Utilities for health states describing oral plus injectable regimens were 0.77 (7 tablets), 0.75 (12 tablets), and 0.71 (18 tablets). Addition of a weekly injection had a disutility of −0.02. A requirement to take medication with fatty food had a disutility of −0.04. Adverse events were associated with substantial disutilities: mild anemia, −0.12; severe anemia, −0.32; flu-like symptoms, −0.21; mild rash, −0.13; severe rash, −0.48; depression, −0.47. One-year TTO scores were similar to these 10-year values. CONCLUSIONS: Adverse events and greater treatment regimen complexity were associated with lower utility scores, suggesting a perceived decrease in quality of life beyond the impact of hepatitis C. The resulting utilities may be used in models estimating and comparing the value of treatments for hepatitis C. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10198-014-0649-6) contains supplementary material, which is available to authorized users

    EXIT Llyod Davies

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    The EXIT (Ex utero intrapartum treatment) procedures have been, with a high degree of success, employed to treat a myriad types of fetal airway obstruction most commonly neck masses such as cystic hygroma and lymphangioma with ample plan including prenatal diagnosis by ultrasound scan or MRI. Before the advent of EXIT, formal documentations had been published with descriptions of intubation during intrapartum period and fetal airway protection either during normal or operative delivery. We report a 28-year-old gravida 2 para 1 who was referred to our Maternal Fetal Medicine (MFM) unit at 26 weeks and 3 days gestation with a foetal neck mass. We present a case of an successful EXIT procedure performed in the Lloyd Davies position with the hips abducted and flexed at 15 degrees as is employed during gynecologic laparoscopy surgery minus the Trendelenburg tilt. Both mother and baby are well. The benefits of this position are discussed

    Effect of strain on the thermomechanical behavior of epoxy based shape memory polymers

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    The effect of deformation strain on the thermomechanical (TM) behavior of a commercially available bifunctional epoxy resin modified with 5 % carboxyl-terminated butadiene acrylonitrile (CTBN) was studied. The results were compared with those for the unmodified epoxy SMP. The glass transition temperatures (Tg) as well as the moduli of these SMPs were determined. Static tensile tests were carried out at both 25 °C and 115 °C to study the effect of CTBN addition on the failure strain. TM cycling tests were conducted for two prescribed strain values: 15 % and 25 %. Further, the effect of the prescribed strain values and TM cycling on the shape-frozen and recovery responses of these SMPs were studied. In addition, microstructure studies were carried out in order to examine the dispersion of the CTBN and the fracture behavior of the CTBN-epoxy SMP. The results show that adding CTBN to the epoxy matrix leads to a slight reduction in storage modulus and Tg. Static tensile tests revealed that there was a noticeable improvement in the failure strain of the CTBNepoxy SMP when it was tested at 115 °C rather than at 25 °C. The cyclic thermomechanical tests performed here prove that the CTBN-epoxy SMP has a better endurance than the unmodified epoxy SMP, as well as enhanced shape-recovery characteristics
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