14 research outputs found

    Association between NS3 and NS5 Proteins of Dengue Virus Type 2 in the

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    Dengue virus type 2, a member of the family Flaviviridae, encodes a single polyprotein precursor consisting of 3391 amino acid residues that is processed to at least 10 mature proteins by host and viral proteases. The NS3 protein contains a domain commonly found in cellular serine proteinases that in cooperation with NS2B is involved in polyprotein processing. In addition, NS3 and NS5 proteins contain conserved motifs found in several RNA helicases and RNA-dependent RNA polymerases, respectively. Both enzymatic activities have been suggested to be involved in viral RNA replication. In this report, we demonstrate that the NS3 and NS5 proteins interact in vivo in dengue virus type 2-infected monkey kidney (CV-1) cells and in HeLa cells coinfected with recombinant vaccinia viruses encoding these proteins as shown by coimmunoprecipitations and immunoblotting methods. We also show by immunofluorescence, metabolic labeling, and two-dimensional peptide mapping that NS5 is a nuclear phosphoprotein and that phosphorylation occurs on serine residues at multiple sites. Furthermore, NS5 exists in differentially phosphorylated states in the nuclear and the cytoplasmic fractions, and only the cytoplasmic form of NS5 is found to coimmunoprecipitate with NS3, suggesting that differential phosphorylation may control the interaction between these proteins and its function in the viral RNA replicase

    Differential susceptibility of a few members of nasuta-albomicans complex of drosophila to paraquat-induced lethality and oxidative stress

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    The evolution of karyotypically stabilized short-lived (SL) and long-lived (LL) cytoraces in the laboratory have been established and validated through our previous lifespan studies. In the present investigation, we examined the possible reason(s) for the differential longevity among selected members of SL and LL cytoraces, employing the well known paraquat (PQ) resistance bioassay. Exposure of these races to varying concentrations of PQ revealed relatively higher resistance among LL cytoraces than SL cytoraces, as evident by the lower incidence of mortality. Biochemical analysis for endogenous markers of oxidative stress revealed that LL-2 cytorace exhibited lower reactive oxygen species (ROS) and lipid peroxidation (LPO) levels, higher activity levels of superoxide dismutase (SOD), and coupled with higher levels of reduced glutathione (GSH) compared with the levels found in SL-2 cytorace. These findings suggest that the higher susceptibility of SL cytoraces to PQ challenge may be, at least in part, related to the higher endogenous levels of oxidative stress markers. Although the precise mechanisms responsible for the longer longevity among LL cytoraces of the nasuta-albomicans complex of Drosophila merits further investigation, our data suggest that the relatively longer lifespan may be related to the status of endogenous markers that renders them more resistant towards oxidative-stress-mediated lethality, as evident in the PQ assay

    Status of Tuberculosis services in Indian Prisons

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    Introduction: Prisons are known to be a high risk environment for tuberculosis (TB) due to overcrowding, low levels of nutrition, poor infection control and lack of accessible healthcare services. India has nearly 1400 prisons housing 0.37 million inmates. However, information on, availability of diagnostic and treatment services for TB in the prison settings is limited. This study examined the availability of TB services in prisons of India. Simultaneously, prison inmates were screened for tuberculosis. Method: The study was conducted in 157 prisons across 300 districts between July-December 2013. Information on services available and practices followed for screening, diagnosis and treatment of TB was collected. Additionally, the inmates and prison staff were sensitised on TB using interpersonal communication materials. The inmates were screened for cough ≥2 weeks as a symptom of TB. Those identified as presumptive TB patients (PTBP) were linked with free diagnostic and treatment services. Results: Diagnostic and treatment services for TB were available in 18% and 54% of the prisons respectively. Only half of the prisons screened inmates for TB on entry, while nearly 60% practised periodic screening of inmates. District level prisons (OR, 6.0; 95% CI, 1.6-22.1), prisons with more than 500 inmates (OR, 52; 95% CI, 1.4-19.2), and prisons practising periodic screening of inmates (OR, 2.7; 95% CI, 1.0-7.2) were more likely to diagnose TB cases. 19% of the inmates screened had symptoms of TB (cough ≥2 weeks) and 8% of the PTBP were diagnosed with TB on smear microscopy. Conclusion: The TB screening, diagnostic and treatment services are sub-optimal in prisons in India and need to be strengthened urgently

    Determination of size-independent specific fracture energy of concrete mixes by the tri-linear model

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    The methods proposed by Elices and co-workers [1], [2] and [3] and by Hu and Wittmann [4] are commonly used to determine the size-independent specific fracture energy (GF) of concrete by correcting the size-dependent specific fracture energy (Gf) measured by the RILEM work-of-fracture method. In the boundary effect model of Hu and Wittmann [4], the change in the local fracture energy (gf) is approximated by a bilinear function, whereas the method of Elices et al. [1] consists in determining the non-measured work-of-fracture by adjusting the tail of the P-δ curve that corresponds to the final part of the test. Acoustic emission (AE) experiments on notched specimens (Muralidhara et al. [5] and [6]) have revealed that under loading the AE events follow approximately a tri-linear distribution; initially the number of events increases almost linearly reaching an extended plateau when the number of events remains nearly constant and eventually the number reduces as the crack approaches the back stress free boundary of the specimen, reminiscent of the development of R-curve in a finite size specimen. This paper exploits this observation and proposes a tri-linear model for the determination of the size-independent specific fracture energy for three different concrete mixes ranging in compressive strength from 57 to 122 MPa. Remarkably, it is found that the resulting size-independent specific fracture energy GF determined by this tri-linear model and by the bi-linear model of Hu and Wittmann [4] is very nearly the same and independent of the size of the specimen
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