52 research outputs found

    Identification and Molecular Characterization of YsaL (Ye3555): A Novel Negative Regulator of YsaN ATPase in Type Three Secretion System of Enteropathogenic Bacteria Yersinia enterocolitica

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    Type Three Secretion (T3S) ATPases are involved in delivery of virulent factors from bacteria to their hosts (through injectisome) in an energy (ATP) dependent manner during pathogenesis. The activities of these ATPases are tightly controlled by their specific regulators. In Yersinia enterocolitica, YsaN was predicted as a putative ATPase of the Ysa-Ysp Type Three Secretion System (T3SS) based on sequence similarity with other T3S ATPases. However detailed study and characterization of YsaN and its regulation remains largely obscure. Here, in this study, we have successfully cloned, overexpressed,purified and characterized the molecular properties of YsaN from Yersinia enterocolitica. YsaN acts as a Mg2+ dependent ATPase and exists in solution as higher order oligomer (dodecamer). The ATPase activity of oligomeric YsaN is several fold higher than the monomeric form. Furthermore, by employing in silico studies we have identified the existence of a negative regulator of YsaN- a hypothetical protein YE3555 (termed ‘YsaL’). To verify the functionality of YsaL, we have evaluated the biochemical and biophysical properties of YsaL. Purified YsaL is dimeric in solution and strongly associates with YsaN to form a stable heterotrimeric YsaL-YsaN complex (stoichiometry- 2:1). The N terminal 6–20 residues of YsaN are invariably required for stable YsaL-YsaN complex formation. YsaL inhibited the ATPase activity of YsaN with a maximum inhibition at the molar ratio 2:1 (YsaL: YsaN). In short, our studies provide an insight into the presence of YsaN ATPase in Yersinia enterocolitica and its regulator YsaL. Our studies also correlate the functionality of one of the existing protein interaction networks that possibly is indispensable for the energy dependent process of Ysa-Ysp T3SS in pathogenic Yersinia enterocolitic

    One Health research and training and government support for One Health in South Asia

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    Introduction: Considerable advocacy, funding, training, and technical support have been provided to South Asian countries to strengthen One Health (OH) collaborative approaches for controlling diseases with global human pandemic potential since the early 2000s. It is essential that the OH approach continues to be strengthened given South Asia is a hot spot for emerging and endemic zoonotic diseases. The objectives of this article are to describe OH research and training and capacity building activities and the important developments in government support for OH in these countries to identify current achievements and gaps. Materials and methods: A landscape analysis of OH research, training, and government support in South Asia was generated by searching peer-reviewed and grey literature for OH research publications and reports, a questionnaire survey of people potentially engaged in OH research in South Asia and the authors’ professional networks. Results: Only a small proportion of zoonotic disease research conducted in South Asia can be described as truly OH, with a significant lack of OH policy-relevant research. A small number of multisectoral OH research and OH capacity building programmes were conducted in the region. The governments of Bangladesh and Bhutan have established operational OH strategies, with variable progress institutionalising OH in other countries. Identified gaps were a lack of useful scientific information and of a collaborative culture for formulating and implementing integrated zoonotic disease control policies and the need for ongoing support for transdisciplinary OH research and policy-relevant capacity building programmes. Discussion: Overall we found a very small number of truly OH research and capacity building programmes in South Asia. Even though significant progress has been made in institutionalising OH in some South Asian countries, further behavioural, attitudinal, and institutional changes are required to strengthen OH research and training and implementation of sustainably effective integrated zoonotic disease control policies

    Identifying sources, pathways and risk drivers in ecosystems of Japanese Encephalitis in an epidemic-prone north Indian district

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    Japanese Encephalitis (JE) has caused repeated outbreaks in endemic pockets of India. This study was conducted in Kushinagar, a highly endemic district, to understand the human-animal-ecosystem interactions, and the drivers that influence disease transmission. Utilizing the ecosystems approach, a cross-sectional, descriptive study, employing mixed methods design was employed. Four villages (two with pig-rearing and two without) were randomly selected from a high, a medium and a low burden (based on case counts) block of Kushinagar. Children, pigs and vectors were sampled from these villages. A qualitative arm was incorporated to explain the findings from the quantitative surveys. All human serum samples were screened for JE-specific IgM using MAC ELISA and negative samples for JE RNA by rRT-PCR in peripheral blood mononuclear cells. In pigs, IgG ELISA and rRT-PCR for viral RNA were used. Of the 242 children tested, 24 tested positive by either rRT-PCR or MAC ELISA; in pigs, 38 out of the 51 pigs were positive. Of the known vectors, Culex vishnui was most commonly isolated across all biotopes. Analysis of 15 blood meals revealed human blood in 10 samples. Univariable analysis showed that gender, religion, lack of indoor residual spraying of insecticides in the past year, indoor vector density (all species), and not being vaccinated against JE in children were significantly associated with JE positivity. In multivariate analysis, only male gender remained as a significant risk factor. Based on previous estimates of symptomatic: asymptomatic cases of JE, we estimate that there should have been 618 cases from Kushinagar, although only 139 were reported. Vaccination of children and vector control measures emerged as major control activities; they had very poor coverage in the studied villages. In addition, lack of awareness about the cause of JE, lack of faith in the conventional medical healthcare system and multiple referral levels causing delay in diagnosis and treatment emerged as factors likely to result in adverse clinical outcomes

    Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

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    Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations

    Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017

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    A double burden of malnutrition occurs when individuals, household members or communities experience both undernutrition and overweight. Here, we show geospatial estimates of overweight and wasting prevalence among children under 5 years of age in 105 low- and middle-income countries (LMICs) from 2000 to 2017 and aggregate these to policy-relevant administrative units. Wasting decreased overall across LMICs between 2000 and 2017, from 8.4% (62.3 (55.1–70.8) million) to 6.4% (58.3 (47.6–70.7) million), but is predicted to remain above the World Health Organization’s Global Nutrition Target of <5% in over half of LMICs by 2025. Prevalence of overweight increased from 5.2% (30 (22.8–38.5) million) in 2000 to 6.0% (55.5 (44.8–67.9) million) children aged under 5 years in 2017. Areas most affected by double burden of malnutrition were located in Indonesia, Thailand, southeastern China, Botswana, Cameroon and central Nigeria. Our estimates provide a new perspective to researchers, policy makers and public health agencies in their efforts to address this global childhood syndemic

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    Mapping inequalities in exclusive breastfeeding in low- and middle-income countries, 2000–2018

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    Exclusive breastfeeding (EBF)—giving infants only breast-milk for the first 6 months of life—is a component of optimal breastfeeding practices effective in preventing child morbidity and mortality. EBF practices are known to vary by population and comparable subnational estimates of prevalence and progress across low- and middle-income countries (LMICs) are required for planning policy and interventions. Here we present a geospatial analysis of EBF prevalence estimates from 2000 to 2018 across 94 LMICs mapped to policy-relevant administrative units (for example, districts), quantify subnational inequalities and their changes over time, and estimate probabilities of meeting the World Health Organization’s Global Nutrition Target (WHO GNT) of ≥70% EBF prevalence by 2030. While six LMICs are projected to meet the WHO GNT of ≥70% EBF prevalence at a national scale, only three are predicted to meet the target in all their district-level units by 2030

    Induction of brain tubulin by triidothyronine: dual effect of the hormone on the synthesis and turnover of the protein

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    The relative effects of triiodothyronine (T<SUB>3</SUB>) on the synthesis and turnover of tubulin in the developing rat and chick brain have been examined. Measurements of rates of turnover of radiolabeled tubulin in the hormone-sensitive tissues show that the half-life of tubulin turnover is 4-6 h in the absence of T<SUB>3</SUB> and 10-12 h in the presence of the hormone. Analysis of short-term kinetic data on the stimulation of tubulin by T<SUB>3</SUB> in the chick brain show that the rapid induction is due to a dual effect of the hormone on the metabolism of tubulin -an increase in the rate of synthesis as well as a decline in its rate of turnover

    Comparative analysis of the membrane proteins and their specificities in neurons, protoplasmic astrocytes, and oligodendrocytes from rat brain

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    Plasma membranes from neuronal perikarya (N), protoplasmic astrocytes (A) and oligodendrocyies (O) of rat brains were analysed with respect to their protein and glycoprotein contents and specificities. SDS-polyacrylamide gel electrophoresis revealed a total number of 23, 17, and 17 major proteins in N, A, and O respectively. Periodate-Schiff''s staining showed that approximately 40-60% of these proteins were glycoproteins. The reactivity of these glycoproteins to Con A and WGA was also studied. Selective iodination of whole cells followed by electrophoresis and autoradiography indicated that of the major proteins, only 25% of neuronal and 60% of astroglial and oligodendroglial membrane proteins were exposed outside the cell surface. The overall results suggest that membrane proteins of each of the three cell types studied here have characteristically different internal and external markers differing in size, glycoprotein content, and reactivity of the glycoproteins to lectins
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