210 research outputs found
Assessing the practicalities of joint snakebite and dog rabies control programs:Commonalities and potential pitfalls
Both rabies and snakebite primarily affect underserved and impoverished communities globally, with an estimated 200,000 people dying from these diseases annually, and the greatest burden being in Africa and Asia. Both diseases have been neglected and have thus been denied appropriate prioritization, support, and interventions, and face many of the challenges common to all neglected tropical diseases (NTDs). In line with the call for integrated approaches between NTDs in the recent NTD Roadmap, we sought to build upon previous conceptualizations for an integrated approach by identifying the commonalities between snakebite and rabies to explore the feasibility of an integrated approach. While multiple areas for potential integration are identified, we highlight the potential pitfalls to integrating rabies and snakebite programs, considering the nuances that make each disease and its intervention program unique. We conclude that health system strengthening, and capacity building should be the focus of any integrated approach among NTDs, and that by strengthening overall health systems, both rabies and snakebite can advocate for further support from governments and stakeholders
Polymorphisms of TNF-enhancer and gene for FcγRIIa correlate with the severity of falciparum malaria in the ethnically diverse Indian population
<p>Abstract</p> <p>Background</p> <p>Susceptibility/resistance to <it>Plasmodium falciparum </it>malaria has been correlated with polymorphisms in more than 30 human genes with most association analyses having been carried out on patients from Africa and south-east Asia. The aim of this study was to examine the possible contribution of genetic variants in the <it>TNF </it>and <it>FCGR2A </it>genes in determining severity/resistance to <it>P. falciparum </it>malaria in Indian subjects.</p> <p>Methods</p> <p>Allelic frequency distribution in populations across India was first determined by typing genetic variants of the <it>TNF </it>enhancer and the <it>FCGR2A </it>G/A SNP in 1871 individuals from 55 populations. Genotyping was carried out by DNA sequencing, single base extension (SNaPshot), and DNA mass array (Sequenom). Plasma TNF was determined by ELISA. Comparison of datasets was carried out by Kruskal-Wallis and Mann-Whitney tests. Haplotypes and LD plots were generated by PHASE and Haploview, respectively. Odds ratio (OR) for risk assessment was calculated using EpiInfo™ version 3.4.</p> <p>Results</p> <p>A novel single nucleotide polymorphism (SNP) at position -76 was identified in the <it>TNF </it>enhancer along with other reported variants. Five <it>TNF </it>enhancer SNPs and the <it>FCGR2A </it>R131H (G/A) SNP were analyzed for association with severity of <it>P. falciparum </it>malaria in a malaria-endemic and a non-endemic region of India in a case-control study with ethnically-matched controls enrolled from both regions. <it>TNF </it>-1031C and -863A alleles as well as homozygotes for the TNF enhancer haplotype CACGG (-1031T>C, -863C>A, -857C>T, -308G>A, -238G>A) correlated with enhanced plasma TNF levels in both patients and controls. Significantly higher TNF levels were observed in patients with severe malaria. Minor alleles of -1031 and -863 SNPs were associated with increased susceptibility to severe malaria. The high-affinity IgG2 binding FcγRIIa AA (131H) genotype was significantly associated with protection from disease manifestation, with stronger association observed in the malaria non-endemic region. These results represent the first genetic analysis of the two immune regulatory molecules in the context of <it>P. falciparum </it>severity/resistance in the Indian population.</p> <p>Conclusion</p> <p>Association of specific <it>TNF </it>and <it>FCGR2A </it>SNPs with cytokine levels and disease severity/resistance was indicated in patients from areas with differential disease endemicity. The data emphasizes the need for addressing the contribution of human genetic factors in malaria in the context of disease epidemiology and population genetic substructure within India.</p
Galactic googly : the rotation-metallicity bias in the inner stellar halo of the Milky Way
The first and second moments of stellar velocities encode important information about the formation history of the Galactic halo. However, due to the lack of tangential motion and inaccurate distances of the halo stars, the velocity moments in the Galactic halo have largely remained ‘known unknowns’. Fortunately, our off-centric position within the Galaxy allows us to estimate these moments in the galactocentric frame using the observed radial velocities of the stars alone. We use these velocities coupled with the hierarchical Bayesian scheme, which allows easy marginalization over the missing data (the proper motion, and uncertainty-free distance and line-of-sight velocity), to measure the velocity dispersions, orbital anisotropy (β) and streaming motion (vrot) of the halo main-sequence turn-off (MSTO) and K-giant (KG) stars in the inner stellar halo (r ≲ 15 kpc). We study the metallicity bias in kinematics of the halo stars and observe that the comparatively metal-rich ([Fe/H] > −1.4) and the metal-poor ([Fe/H] ≤ −1.4) MSTO samples show a clear systematic difference in vrot ∼ 20-40 km s−1, depending on how restrictive the spatial cuts to cull the disc contamination are. The bias is also detected in KG samples but with less certainty. Both MSTO and KG populations suggest that the inner stellar halo of the Galaxy is radially biased i.e. σr > σθ or σϕ and β ≃ 0.5. The apparent metallicity contrariety in the rotation velocity among the halo sub-populations supports the co-existence of multiple populations in the galactic halo that may have formed through distinct formation scenarios, i.e. in situ versus accretion.Publisher PDFPeer reviewe
Variations in host genes encoding adhesion molecules and susceptibility to falciparum malaria in India
<p>Abstract</p> <p>Background</p> <p>Host adhesion molecules play a significant role in the pathogenesis of <it>Plasmodium falciparum </it>malaria and changes in their structure or levels in individuals can influence the outcome of infection. The aim of this study was to investigate the association of SNPs of three adhesion molecule genes, <it>ICAM1</it>, <it>PECAM1 </it>and <it>CD36</it>, with severity of falciparum malaria in a malaria-endemic and a non-endemic region of India.</p> <p>Methods</p> <p>The frequency distribution of seven selected SNPs of <it>ICAM1</it>, <it>PECAM1 </it>and <it>CD36 </it>was determined in 552 individuals drawn from 24 populations across India. SNP-disease association was analysed in a case-control study format. Genotyping of the population panel was performed by Sequenom mass spectroscopy and patient/control samples were genotyped by SNaPshot method. Haplotypes and linkage disequilibrium (LD) plots were generated using PHASE and Haploview, respectively. Odds-ratio (OR) for risk assessment was estimated using EpiInfo™ version 3.4.</p> <p>Results</p> <p>Association of the ICAM1 rs5498 (exon 6) G allele and the CD36 exon 1a A allele with increased risk of severe malaria was observed (severe versus control, OR = 1.91 and 2.66, P = 0.02 and 0.0012, respectively). The CD36 rs1334512 (-53) T allele as well as the TT genotype associated with protection from severe disease (severe versus control, TT versus GG, OR = 0.37, P = 0.004). Interestingly, a SNP of the <it>PECAM1 </it>gene (rs668, exon 3, C/G) with low minor allele frequency in populations of the endemic region compared to the non-endemic region exhibited differential association with disease in these regions; the G allele was a risk factor for malaria in the endemic region, but exhibited significant association with protection from disease in the non-endemic region.</p> <p>Conclusion</p> <p>The data highlights the significance of variations in the <it>ICAM1</it>, <it>PECAM1 </it>and <it>CD36 </it>genes in the manifestation of falciparum malaria in India. The <it>PECAM1 </it>exon 3 SNP exhibits altered association with disease in the endemic and non-endemic region.</p
The accretion origin of the Milky Way's stellar halo
We have used data from the Sloan Digital Sky Survey (SDSS) Data Release 5 to
explore the overall structure and substructure of the stellar halo of the Milky
Way using about 4 million color-selected main sequence turn-off stars. We fit
oblate and triaxial broken power-law models to the data, and found a `best-fit'
oblateness of the stellar halo 0.5<c/a<0.8, and halo stellar masses between
Galactocentric radii of 1 and 40kpc of (3.7+/-1.2)x10^8 M_sun. The density
profile of the stellar halo is approximately r^{-3}; it is possible that the
power law slope is shallower inside 20kpc and steeper outside that radius. Yet,
we found that all smooth and symmetric models were very poor fits to the
distribution of stellar halo stars because the data exhibit a great deal of
spatial substructure. We quantified deviations from a smooth oblate/triaxial
model using the RMS of the data around the model profile on scales >~100pc,
after accounting for the (known) contribution of Poisson uncertainties. The
fractional RMS deviation of the actual stellar distribution from any smooth,
parameterized halo model is >~40%: hence, the stellar halo is highly
structured. We compared the observations with simulations of galactic stellar
halos formed entirely from the accretion of satellites in a cosmological
context by analysing the simulations in the same way as the data. While the
masses, overall profiles, and degree of substructure in the simulated stellar
halos show considerable scatter, the properties and degree of substructure in
the Milky Way's halo match well the properties of a `typical' stellar halo
built exclusively out of the debris from disrupted satellite galaxies. Our
results therefore point towards a picture in which an important fraction of the
Milky Way's stellar halo has been accreted from satellite galaxies.Comment: Submitted to the Astrophysical Journal. 14 pages; 11 figure
Trichosanthes dioica root extract induces tumor proliferation and attenuation of antioxidant system in albino mice bearing Ehrlich ascites carcinoma
Trichosanthes dioica Roxb. (Cucurbitaceae), called pointed gourd in English, is a dioecious climber grown widely in the Indian subcontinent. The present study assessed the influence of treatment of hydroalcoholic extract of Trichosanthes dioica root (TDA) on Ehrlich ascites carcinoma (EAC) in Swiss albino mice with effects on antioxidant systems. Twenty-four hours after intraperitoneal inoculation of tumor (EAC) cells in mice, TDA was administered at 25 and 50 mg/kg for 8 consecutive days. On the 9th day, half of the mice were sacrificed for estimation of tumor proliferation, hematological, and hepatic antioxidative parameters. The rest were kept for assessment of survival parameters. TDA exhibited dose dependent and significant increase in tumor weight, tumor volume, packed cell volume and viable cells and reduced non-viable cells and life span of EAC bearing animals. Hematological parameters were significantly worsened in TDA-treated mice. TDA treatment significantly aggravated the hepatic antioxidative parameters. The present study demonstrated that T. dioica root possessed tumor promoting activity in EAC bearing albino mice, plausibly mediated by attenuation of endogenous antioxidant systems
The GALAH survey: relative throughputs of the 2dF fibre positioner and the HERMES spectrograph from stellar targets
We present an analysis of the relative throughputs of the 3.9-m Anglo-Australian Telescope’s 2dF/HERMES (High Efficiency and Resolution Multi-Element Spectrograph) system, based upon spectra acquired during the first two years of the Galactic Archaeology with HERMES survey. Averaged spectral fluxes of stars were compared to their photometry to determine the relative throughputs of fibres for a range of fibre position and atmospheric conditions. We find that overall the throughputs of the 771 usable fibres have been stable over the first two years of its operation. About 2.5 per cent of fibres have throughputs much lower than the average. There are also a number of yet unexplained variations between the HERMES bandpasses, and mechanically and optically linked fibre groups known as retractors or slitlets related to regions
of the focal plane. These findings do not impact the science that HERMES will produce
Frailty and outcomes in heart failure patients from high-, middle-, and low-income countries
Background and Aims:
There is little information on the incremental prognostic importance of frailty beyond conventional prognostic variables in heart failure (HF) populations from different country income levels.
Methods:
A total of 3429 adults with HF (age 61 ± 14 years, 33% women) from 27 high-, middle- and low-income countries were prospectively studied. Baseline frailty was evaluated by the Fried index, incorporating handgrip strength, gait speed, physical activity, unintended weight loss, and self-reported exhaustion. Mean left ventricular ejection fraction was 39 ± 14% and 26% had New York Heart Association Class III/IV symptoms. Participants were followed for a median (25th to 75th percentile) of 3.1 (2.0–4.3) years. Cox proportional hazard models for death and HF hospitalization adjusted for country income level; age; sex; education; HF aetiology; left ventricular ejection fraction; diabetes; tobacco and alcohol use; New York Heart Association functional class; HF medication use; blood pressure; and haemoglobin, sodium, and creatinine concentrations were performed. The incremental discriminatory value of frailty over and above the MAGGIC risk score was evaluated by the area under the receiver-operating characteristic curve.
Results:
At baseline, 18% of participants were robust, 61% pre-frail, and 21% frail. During follow-up, 565 (16%) participants died and 471 (14%) were hospitalized for HF. Respective adjusted hazard ratios (95% confidence interval) for death among the pre-frail and frail were 1.59 (1.12–2.26) and 2.92 (1.99–4.27). Respective adjusted hazard ratios (95% confidence interval) for HF hospitalization were 1.32 (0.93–1.87) and 1.97 (1.33–2.91). Findings were consistent among different country income levels and by most subgroups. Adding frailty to the MAGGIC risk score improved the discrimination of future death and HF hospitalization.
Conclusions:
Frailty confers substantial incremental prognostic information to prognostic variables for predicting death and HF hospitalization. The relationship between frailty and these outcomes is consistent across countries at all income levels
Snake Bite in South Asia: A Review
Snake bite is one of the most neglected public health issues in poor rural communities living in the tropics. Because of serious misreporting, the true worldwide burden of snake bite is not known. South Asia is the world's most heavily affected region, due to its high population density, widespread agricultural activities, numerous venomous snake species and lack of functional snake bite control programs. Despite increasing knowledge of snake venoms' composition and mode of action, good understanding of clinical features of envenoming and sufficient production of antivenom by Indian manufacturers, snake bite management remains unsatisfactory in this region. Field diagnostic tests for snake species identification do not exist and treatment mainly relies on the administration of antivenoms that do not cover all of the important venomous snakes of the region. Care-givers need better training and supervision, and national guidelines should be fed by evidence-based data generated by well-designed research studies. Poorly informed rural populations often apply inappropriate first-aid measures and vital time is lost before the victim is transported to a treatment centre, where cost of treatment can constitute an additional hurdle. The deficiency of snake bite management in South Asia is multi-causal and requires joint collaborative efforts from researchers, antivenom manufacturers, policy makers, public health authorities and international funders
The sixth data release of the Radial Velocity Experiment (RAVE). I. Survey description, spectra and radial velocities
The Radial Velocity Experiment (RAVE) is a magnitude-limited (9<I<12)
spectroscopic survey of Galactic stars randomly selected in the southern
hemisphere. The RAVE medium-resolution spectra (R~7500) cover the Ca-triplet
region (8410-8795A). The 6th and final data release (DR6 or FDR) is based on
518387 observations of 451783 unique stars. RAVE observations were taken
between 12 April 2003 and 4 April 2013. Here we present the genesis, setup and
data reduction of RAVE as well as wavelength-calibrated and flux-normalized
spectra and error spectra for all observations in RAVE DR6. Furthermore, we
present derived spectral classification and radial velocities for the RAVE
targets, complemented by cross matches with Gaia DR2 and other relevant
catalogs. A comparison between internal error estimates, variances derived from
stars with more than one observing epoch and a comparison with radial
velocities of Gaia DR2 reveals consistently that 68% of the objects have a
velocity accuracy better than 1.4 km/s, while 95% of the objects have radial
velocities better than 4.0 km/s. Stellar atmospheric parameters, abundances and
distances are presented in subsequent publication. The data can be accessed via
the RAVE Web (http://rave-survey.org) or the Vizier database.Comment: 32 pages, 11 figures, accepted for publication to A
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