144 research outputs found
Competitive and Cooperative Interactions Mediate RNA Transfer from Herpesvirus Saimiri ORF57 to the Mammalian Export Adaptor ALYREF
The essential herpesvirus adaptor protein HVS ORF57, which has homologs in all other herpesviruses, promotes viral mRNA
export by utilizing the cellular mRNA export machinery. ORF57 protein specifically recognizes viral mRNA transcripts, and
binds to proteins of the cellular transcription-export (TREX) complex, in particular ALYREF. This interaction introduces viral
mRNA to the NXF1 pathway, subsequently directing it to the nuclear pore for export to the cytoplasm. Here we have used a
range of techniques to reveal the sites for direct contact between RNA and ORF57 in the absence and presence of ALYREF. A
binding site within ORF57 was characterized which recognizes specific viral mRNA motifs. When ALYREF is present, part of
this ORF57 RNA binding site, composed of an a-helix, binds preferentially to ALYREF. This competitively displaces viral RNA
from the a-helix, but contact with RNA is still maintained by a flanking region. At the same time, the flexible N-terminal
domain of ALYREF comes into contact with the viral RNA, which becomes engaged in an extensive network of synergistic
interactions with both ALYREF and ORF57. Transfer of RNA to ALYREF in the ternary complex, and involvement of individual
ORF57 residues in RNA recognition, were confirmed by UV cross-linking and mutagenesis. The atomic-resolution structure
of the ORF57-ALYREF interface was determined, which noticeably differed from the homologous ICP27-ALYREF structure.
Together, the data provides the first site-specific description of how viral mRNA is locked by a herpes viral adaptor protein in
complex with cellular ALYREF, giving herpesvirus access to the cellular mRNA export machinery. The NMR strategy used
may be more generally applicable to the study of fuzzy protein-protein-RNA complexes which involve flexible polypeptide
regions
Mapping of variations in child stunting, wasting and underweight within the states of India: the Global Burden of Disease Study 2000–2017
Background
To inform actions at the district level under the National Nutrition Mission (NNM), we assessed the prevalence trends of child growth failure (CGF) indicators for all districts in India and inequality between districts within the states.
Methods
We assessed the trends of CGF indicators (stunting, wasting and underweight) from 2000 to 2017 across the districts of India, aggregated from 5 × 5 km grid estimates, using all accessible data from various surveys with subnational geographical information. The states were categorised into three groups using their Socio-demographic Index (SDI) levels calculated as part of the Global Burden of Disease Study based on per capita income, mean education and fertility rate in women younger than 25 years. Inequality between districts within the states was assessed using coefficient of variation (CV). We projected the prevalence of CGF indicators for the districts up to 2030 based on the trends from 2000 to 2017 to compare with the NNM 2022 targets for stunting and underweight, and the WHO/UNICEF 2030 targets for stunting and wasting. We assessed Pearson correlation coefficient between two major national surveys for district-level estimates of CGF indicators in the states.
Findings
The prevalence of stunting ranged 3.8-fold from 16.4% (95% UI 15.2–17.8) to 62.8% (95% UI 61.5–64.0) among the 723 districts of India in 2017, wasting ranged 5.4-fold from 5.5% (95% UI 5.1–6.1) to 30.0% (95% UI 28.2–31.8), and underweight ranged 4.6-fold from 11.0% (95% UI 10.5–11.9) to 51.0% (95% UI 49.9–52.1). 36.1% of the districts in India had stunting prevalence 40% or more, with 67.0% districts in the low SDI states group and only 1.1% districts in the high SDI states with this level of stunting. The prevalence of stunting declined significantly from 2010 to 2017 in 98.5% of the districts with a maximum decline of 41.2% (95% UI 40.3–42.5), wasting in 61.3% with a maximum decline of 44.0% (95% UI 42.3–46.7), and underweight in 95.0% with a maximum decline of 53.9% (95% UI 52.8–55.4). The CV varied 7.4-fold for stunting, 12.2-fold for wasting, and 8.6-fold for underweight between the states in 2017; the CV increased for stunting in 28 out of 31 states, for wasting in 16 states, and for underweight in 20 states from 2000 to 2017. In order to reach the NNM 2022 targets for stunting and underweight individually, 82.6% and 98.5% of the districts in India would need a rate of improvement higher than they had up to 2017, respectively. To achieve the WHO/UNICEF 2030 target for wasting, all districts in India would need a rate of improvement higher than they had up to 2017. The correlation between the two national surveys for district-level estimates was poor, with Pearson correlation coefficient of 0.7 only in Odisha and four small north-eastern states out of the 27 states covered by these surveys.
Interpretation
CGF indicators have improved in India, but there are substantial variations between the districts in their magnitude and rate of decline, and the inequality between districts has increased in a large proportion of the states. The poor correlation between the national surveys for CGF estimates highlights the need to standardise collection of anthropometric data in India. The district-level trends in this report provide a useful reference for targeting the efforts under NNM to reduce CGF across India and meet the Indian and global targets.
Keywords
Child growth failureDistrict-levelGeospatial mappingInequalityNational Nutrition MissionPrevalenceStuntingTime trendsUnder-fiveUndernutritionUnderweightWastingWHO/UNICEF target
Subnational mapping of under-5 and neonatal mortality trends in India: the Global Burden of Disease Study 2000–17
Randomized Clinical Trial of High-Dose Rifampicin With or Without Levofloxacin Versus Standard of Care for Pediatric Tuberculous Meningitis: The TBM-KIDS Trial
Background. Pediatric tuberculous meningitis (TBM) commonly causes death or disability. In adults, high-dose rifampicin may reduce mortality. The role of fluoroquinolones remains unclear. There have been no antimicrobial treatment trials for pediatric TBM.
Methods. TBM-KIDS was a phase 2 open-label randomized trial among children with TBM in India and Malawi. Participants received isoniazid and pyrazinamide plus: (i) high-dose rifampicin (30 mg/kg) and ethambutol (R30HZE, arm 1); (ii) high-dose rifampicin
and levofloxacin (R30HZL, arm 2); or (iii) standard-dose rifampicin and ethambutol (R15HZE, arm 3) for 8 weeks, followed by 10 months of standard treatment. Functional and neurocognitive outcomes were measured longitudinally using Modified Rankin Scale (MRS) and Mullen Scales of Early Learning (MSEL).
Results. Of 2487 children prescreened, 79 were screened and 37 enrolled. Median age was 72 months; 49%, 43%, and 8% had stage I, II, and III disease, respectively. Grade 3 or higher adverse events occurred in 58%, 55%, and 36% of children in arms 1, 2, and 3, with 1 death (arm 1) and 6 early treatment discontinuations (4 in arm 1, 1 each in arms 2 and 3). By week 8, all children recovered to MRS score of 0 or 1. Average MSEL scores were significantly better in arm 1 than arm 3 in fine motor, receptive language, and expressive language domains (P < .01).
Conclusions. In a pediatric TBM trial, functional outcomes were excellent overall. The trend toward higher frequency of adverse events but better neurocognitive outcomes in children receiving high-dose rifampicin requires confirmation in a larger trial.
Clinical Trials Registration. NCT02958709
Nations within a nation: variations in epidemiological transition across the states of India, 1990–2016 in the Global Burden of Disease Study
18% of the world's population lives in India, and many states of India have populations similar to those of large countries. Action to effectively improve population health in India requires availability of reliable and comprehensive state-level estimates of disease burden and risk factors over time. Such comprehensive estimates have not been available so far for all major diseases and risk factors. Thus, we aimed to estimate the disease burden and risk factors in every state of India as part of the Global Burden of Disease (GBD) Study 2016
AC-AC Matrix Converter-based Grid-Side Power Converter for EV Wireless Charging
The need for efficient power transfer at lower cost is a common requisite for any power converter system. When considering the application of wireless power transfer for Electric Vehicle(EV) charging, higher efficiency and lower cost can be achieved by reducing the number of stages of the system at the grid side. This thesis explores the feasibility of an AC/AC matrix converter for wireless power transfer application. To begin with, different existing topologies of the converter module are discussed and qualitatively compared to the matrix converter. Subsequently, the plausibility of single stage matrix converter is verified through simulation. Due to the converter’s high switching frequency, this configuration results in injection of higher than permitted harmonic content into the grid. Furthermore, the feasibility of three phase matrix converter and its advantages are studied. The converter working is verified through simulation. To make the grid current less distorted, closed loop control is introduced. This control consists of an inner current loop and an outer voltage loop which are both implemented using a PI controller. To conclude, three phase matrix converter acts as a plausible solution for the desired application. Furthermore, the control ensures balanced grid current and desired output power
Epstein-Barr Virus SM Protein Functions as an Alternative Splicing Factor ▿
Alternative splicing of RNA increases the coding potential of the genome and allows for additional regulatory control over gene expression. The full extent of alternative splicing remains to be defined but is likely to significantly expand the size of the human transcriptome. There are several examples of mammalian viruses regulating viral splicing or inhibiting cellular splicing in order to facilitate viral replication. Here, we describe a viral protein that induces alternative splicing of a cellular RNA transcript. Epstein-Barr virus (EBV) SM protein is a viral protein essential for replication that enhances EBV gene expression by enhancing RNA stability and export. SM also increases cellular STAT1 expression, a central mediator of interferon signal transduction, but disproportionately increases the abundance of the STAT1β splicing isoform, which can act as a dominant-negative suppressor of STAT1α. SM induces splicing of STAT1 at a novel 5′ splice site, resulting in a STAT1 mRNA incapable of producing STAT1α. SM-induced alternative splicing is dependent on the presence of an RNA sequence to which SM binds directly and which can confer SM-dependent splicing on heterologous RNA. The cellular splicing factor ASF/SF2 also binds to this region and inhibits SM-RNA binding and SM-induced alternative splicing. These results suggest that viruses may regulate cellular gene expression at the level of alternative mRNA splicing in order to facilitate virus replication or persistence in vivo
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