Showing papers by "Prabhat Jha published in 2015"

Biochemistry and genetics of ACC deaminase: a weapon to "stress ethylene" produced in plants.

Abstract: 1-aminocyclopropane-1-carboxylate deaminase (ACCD), a pyridoxal phosphate-dependent enzyme, is widespread in diverse bacterial and fungal species. Owing to ACCD activity, certain plant associated bacteria help plant to grow under biotic and abiotic stresses by decreasing the level of "stress ethylene" which is inhibitory to plant growth. ACCD breaks down ACC, an immediate precursor of ethylene, to ammonia and α-ketobutyrate, which can be further metabolized by bacteria for their growth. ACC deaminase is an inducible enzyme whose synthesis is induced in the presence of its substrate ACC. This enzyme encoded by gene AcdS is under tight regulation and regulated differentially under different environmental conditions. Regulatory elements of gene AcdS are comprised of the regulatory gene encoding LRP protein and other regulatory elements which are activated differentially under aerobic and anaerobic conditions. The role of some additional regulatory genes such as AcdB or LysR may also be required for expression of AcdS. Phylogenetic analysis of AcdS has revealed that distribution of this gene among different bacteria might have resulted from vertical gene transfer with occasional horizontal gene transfer (HGT). Application of bacterial AcdS gene has been extended by developing transgenic plants with ACCD gene which showed increased tolerance to biotic and abiotic stresses in plants. Moreover, distribution of ACCD gene or its homolog's in a wide range of species belonging to all three domains indicate an alternative role of ACCD in the physiology of an organism. Therefore, this review is an attempt to explore current knowledge of bacterial ACC deaminase mediated physiological effects in plants, mode of enzyme action, genetics, distribution among different species, ecological role of ACCD and, future research avenues to develop transgenic plants expressing foreign AcdS gene to cope with biotic and abiotic stressors. Systemic identification of regulatory circuits would be highly valuable to express the gene under diverse environmental conditions.

Exposure to second-hand smoke and the risk of tuberculosis in children and adults: a systematic review and meta-analysis of 18 observational studies.

Abstract: Background According to WHO Global Health Estimates, tuberculosis (TB) is among the top ten causes of global mortality and ranks second after cardiovascular disease in most high-burden regions. In this systematic review and meta-analysis, we investigated the role of second-hand smoke (SHS) exposure as a risk factor for TB among children and adults. Methods and Findings We performed a systematic literature search of PubMed, Embase, Scopus, Web of Science, and Google Scholar up to August 31, 2014. Our a priori inclusion criteria encompassed only original studies where latent TB infection (LTBI) and active TB disease were diagnosed microbiologically, clinically, histologically, or radiologically. Effect estimates were pooled using fixed- and random-effects models. We identified 18 eligible studies, with 30,757 children and 44,432 adult non-smokers, containing SHS exposure and TB outcome data for inclusion in the meta-analysis. Twelve studies assessed children and eight studies assessed adult non-smokers; two studies assessed both populations. Summary relative risk (RR) of LTBI associated with SHS exposure in children was similar to the overall effect size, with high heterogeneity (pooled RR 1.64, 95% CI 1.00–2.83). Children showed a more than 3-fold increased risk of SHS-associated active TB (pooled RR 3.41, 95% CI 1.81–6.45), which was higher than the risk in adults exposed to SHS (summary RR 1.32, 95% CI 1.04–1.68). Positive and significant exposure–response relationships were observed among children under 5 y (RR 5.88, 95% CI 2.09–16.54), children exposed to SHS through any parent (RR 4.20, 95% CI 1.92–9.20), and children living under the most crowded household conditions (RR 5.53, 95% CI 2.36–12.98). Associations for LTBI and active TB disease remained significant after adjustment for age, biomass fuel (BMF) use, and presence of a TB patient in the household, although the meta-analysis was limited to a subset of studies that adjusted for these variables. There was a loss of association with increased risk of LTBI (but not active TB) after adjustment for socioeconomic status (SES) and study quality. The major limitation of this analysis is the high heterogeneity in outcomes among studies of pediatric cases of LTBI and TB disease. Conclusions We found that SHS exposure is associated with an increase in the relative risk of LTBI and active TB after controlling for age, BMF use, and contact with a TB patient, and there was no significant association of SHS exposure with LTBI after adjustment for SES and study quality. Given the high heterogeneity among the primary studies, our analysis may not show sufficient evidence to confirm an association. In addition, considering that the TB burden is highest in countries with increasing SHS exposure, it is important to confirm these results with higher quality studies. Research in this area may have important implications for TB and tobacco control programs, especially for children in settings with high SHS exposure and TB burden.

Facility Delivery, Postnatal Care and Neonatal Deaths in India: Nationally-Representative Case-Control Studies.

Abstract: Objective Clinical studies demonstrate the efficacy of interventions to reduce neonatal deaths, but there are fewer studies of their real-life effectiveness. In India, women often seek facility delivery after complications arise, rather than to avoid complications. Our objective was to quantify the association of facility delivery and postnatal checkups with neonatal mortality while examining the “reverse causality” in which the mothers deliver at a health facility due to adverse perinatal events. Methods We conducted nationally representative case-control studies of about 300,000 live births and 4,000 neonatal deaths to examine the effect of, place of delivery and postnatal checkup on neonatal mortality. We compared neonatal deaths to all live births and to a subset of live births reporting excessive bleeding or obstructed labour that were more comparable to cases in seeking care. Findings In the larger study of 2004–8 births, facility delivery without postnatal checkup was associated with an increased odds of neonatal death (Odds ratio = 2.5; 99% CI 2.2–2.9), especially for early versus late neonatal deaths. However, use of more comparable controls showed marked attenuation (Odds ratio = 0.5; 0.4–0.5). Facility delivery with postnatal checkup was associated with reduced odds of neonatal death. Excess risks were attenuated in the earlier study of 2001–4 births. Conclusion The combined effect of facility deliveries with postnatal checks ups is substantially higher than just facility delivery alone. Evaluation of the real-life effectiveness of interventions to reduce child and maternal deaths need to consider reverse causality. If these associations are causal, facility delivery with postnatal check up could avoid about 1/3 of all neonatal deaths in India (~100,000/year).

Cancer: Disease Control Priorities, Third Edition (Volume 3)

Abstract: Volume 3, Cancer, presents the complex patterns of cancer incidence and death around the world and evidence on effective and cost-effective ways to control cancers. The DCP3 evaluation of cancer will indicate where cancer treatment is ineffective and wasteful, and offer alternative cancer care packages that are cost-effective and suited to low-resource settings. Main messages from the volume include:-Quality matters in all aspects of cancer treatment and palliation.-Cancer registries that track incidence, mortality, and survival paired with systems to capture causes of death are important to understanding the national cancer burden and the effect of interventions over time.-Effective interventions exist at a range of prices. Adopting ‘resource appropriate’ measures which allow the most effective treatment for the greatest number of people will be advantageous to countries.-Prioritizing resources toward early stage and curable cancers is likely to have the greatest health impact in low income settings.-Research prioritization is no longer just a global responsibility.Providing cancer treatment requires adequate numbers of trained healthcare professionals and infrastructure beyond what is available in most LMICs, especially low income countries. Careful patient monitoring is a requirement of good quality cancer care and this often involves laboratory tests in addition to clinical examination. Even if financing were immediately available to build or expand a cancer control system, reaching capacity will take many years.

Naive Bayes classifiers for verbal autopsies: comparison to physician-based classification for 21,000 child and adult deaths

Abstract: Verbal autopsies (VA) are increasingly used in low- and middle-income countries where most causes of death (COD) occur at home without medical attention, and home deaths differ substantially from hospital deaths. Hence, there is no plausible “standard” against which VAs for home deaths may be validated. Previous studies have shown contradictory performance of automated methods compared to physician-based classification of CODs. We sought to compare the performance of the classic naive Bayes classifier (NBC) versus existing automated classifiers, using physician-based classification as the reference. We compared the performance of NBC, an open-source Tariff Method (OTM), and InterVA-4 on three datasets covering about 21,000 child and adult deaths: the ongoing Million Death Study in India, and health and demographic surveillance sites in Agincourt, South Africa and Matlab, Bangladesh. We applied several training and testing splits of the data to quantify the sensitivity and specificity compared to physician coding for individual CODs and to test the cause-specific mortality fractions at the population level. The NBC achieved comparable sensitivity (median 0.51, range 0.48-0.58) to OTM (median 0.50, range 0.41-0.51), with InterVA-4 having lower sensitivity (median 0.43, range 0.36-0.47) in all three datasets, across all CODs. Consistency of CODs was comparable for NBC and InterVA-4 but lower for OTM. NBC and OTM achieved better performance when using a local rather than a non-local training dataset. At the population level, NBC scored the highest cause-specific mortality fraction accuracy across the datasets (median 0.88, range 0.87-0.93), followed by InterVA-4 (median 0.66, range 0.62-0.73) and OTM (median 0.57, range 0.42-0.58). NBC outperforms current similar COD classifiers at the population level. Nevertheless, no current automated classifier adequately replicates physician classification for individual CODs. There is a need for further research on automated classifiers using local training and test data in diverse settings prior to recommending any replacement of physician-based classification of verbal autopsies.

Global Hazards of Tobacco and the Benefits of Smoking Cessation and Tobacco Taxes

Abstract: Tobacco use kills approximately five million people annually worldwide, accounting for over 20 percent of all deaths of adult men and 5 percent of deaths of adult women. As death rates from causes not attributed to tobacco are falling, the proportion of all adult deaths due to smoking will rise. In the 20th century, 100 million tobacco deaths occurred; nearly 70 percent were in high-income countries (HICs) and the former socialist economies of Europe. In contrast, in the 21st century, tobacco is expected to kill about one billion people, mostly in low- and middle-income countries (LMICs).Widespread use of a few powerful interventions affecting tobacco price, information, and regulations could prevent tens of millions of premature deaths over the next few decades.This chapter starts with the epidemiology of smoking-related diseases, focusing on contemporary estimates of the hazards of smoking and the benefits of cessation, and then describes current and future smoking patterns, including the rapid emergence of electronic cigarettes. We next turn to interventions to rapidly raise cessation rates in LMICs, in particular, higher excise taxes on tobacco products. We discuss the cost-effectiveness, cost-benefit, and poverty considerations of tobacco control and conclude by reviewing the current state of global tobacco control implementation.

Corrigendum: Biochemistry and genetics of ACC deaminase: a weapon to "stress ethylene" produced in plants.

Abstract: We mistakenly did not cite the reference Gontia-Mishra et al. (2014) in the text. Please find the following corrected paragraph with the given citation in the appropriate place. The full citation is also written below for inclusion in the reference list. As reviewed in Gontia-Mishra et al. (2014), among eukaryotes, production of ACCD is well evident in some fungi, which include a few species of yeast such as Hansenula saturnus (Minami et al., 1998), Issatchenkia occidentalis (Palmer et al., 2007), other fungal species namely Penicillium citrinum and Trichoderma asperellum, and a stramnopile, Phytophthora sojae (Jia et al., 1999; Viterbo et al., 2010; Singh and Kashyap, 2012). Recently, ACCD activity has also been observed in certain plants such as Arabidopsis thaliana, poplar, and tomato plant (McDonnell et al., 2009; Plett et al., 2009).

Click chemistry inspired synthesis of piperazine-triazole derivatives and evaluation of their antimicrobial activities

Abstract: A series of novel piperazine-1,2,3-triazole derivatives, which entailed the bioisosteric replacement of the imidazole moiety and hybridization of two drug scaffolds was prepared by employing the regioselective copper (I)-catalysed azide-alkyne 1,3-dipolar cycloaddition reaction. The synthesized compounds were evaluated for antibacterial activities against Gram-negative (E. Coli and P. Putida), Gram-positive S. Aureus bacteria and fungicidal activities against F. oxysporum, F. gramillarium and F. monalliforme fungi. Compound 7ac′ exhibited moderate but promising antibacterial activity against Gram-negative bacteria and fungicidal activity against F. oxysporum and F. gramillarium.

Estimates of the economic contributions of the bidi manufacturing industry in India

Abstract: Background Bidis, the most common smoking tobacco product in India, remain largely untaxed and are subject to very few regulations to discourage their use. A major argument against tax increases is the large potential loss of economic activity and employment in the bidi industry from reduced consumption. Methods We used a nationally representative survey of unorganised bidi manufacturing firms (n=2841) in India to estimate the economic contribution of the industry. Results We find that of the 35 states and union territories of India, the bidi industry operated across 17 states, with over 95% of its production concentrated in 10 states. Bidi manufacturing firms contributed 0.50% of total sales and 0.6% of the gross value added by the manufacturing economy in 2005–2006. The industry employed approximately 3.4 million full-time workers, which comprise about 0.7% of employment in all sectors. A further 0.7 million were part-time workers. Bidi workers were also among the lowest paid employees in India. The industry offered only 0.09% of all compensation provided in the manufacturing sector (organised and unorganised). Conclusions Considering the relatively small economic footprint of the bidi industry in India, higher excise taxes and regulations on bidis are unlikely to disrupt economic growth at an aggregate level, or lead to mass unemployment and economic hardship among small bidi workers. On average, the economic annual output per bidi worker is about US$143, which is an order of magnitude smaller than the large economic losses from the several hundred thousand deaths due to bidi smoking per year.

Molecular identification and characterization of rhizospheric bacteria for plant growth pro- moting ability

Abstract: The objective of this study was to isolate and characterize a rhizospheric bacterium from Sorgastrum nutans, growing around the desert region of Rajasthan (India). Plant growth promoting rhizobacteria (PGPR) are known to influence plant growth by various direct or indirect mechanisms. Isolated strain was tested for various PGP traits like 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, phosphate solubilization, indole acetic acid production, production of siderophore, nitrogen fixation and ammonia production. Bio-control ability of isolate was screened by antagonistic activity against certain fungal/bacterial pathogens as well as Hydrogen cyanide HCN production. Isolated test organism was also biochemically characterized. Further identification of isolate was performed by PCR based 16S rRNA gene sequencing. Moreover evaluation of the isolate SNP-18 exhibiting multiple plant growth promoting (PGP) traits on soil/plant system is on-going to uncover their efficacy as effective PGPR.

Are Global and Regional Improvements in Life Expectancy and in Child, Adult and Senior Survival Slowing?

Abstract: Improvements in life expectancy have been considerable over the past hundred years. Forecasters have taken to applying historical trends under an assumption of continuing improvements in life expectancy in the future. A linear mixed effects model was used to estimate the trends in global and regional rates of improvements in life expectancy, child, adult, and senior survival, in 166 countries between 1950 and 2010. Global improvements in life expectancy, including both child and adult survival rates, decelerated significantly over the study period. Overall life expectancy gains were estimated to have declined from 5.9 to 4.0 months per year for a mean deceleration of -0.07 months/year2; annual child survival gains declined from 4.4 to 1.6 deaths averted per 1000 for a mean deceleration of -0.06 deaths/1000/year2; adult survival gains were estimated to decline from 4.8 to 3.7 deaths averted per 1000 per year for a mean deceleration of -0.08 deaths/1000/year2. Senior survival gains however increased from 2.4 to 4.2 deaths averted per 1000 per year for an acceleration of 0.03 deaths/1000/year2. Regional variation in the four measures was substantial. The rates of global improvements in life expectancy, child survival, and adult survival have declined since 1950 despite an increase in the rate of improvements among seniors. We postulate that low-cost innovation, related to the last half-century progress in health–primarily devoted to children and middle age, is reaping diminishing returns on its investments. Trends are uneven across regions and measures, which may be due in part to the state of epidemiological transition between countries and regions and disparities in the diffusion of innovation, accessible only in high-income countries where life expectancy is already highest.

Screening of potential PGPR candidates as future biofertilizers-A strategic approach from lab to field

Abstract: A vast increase in population, urbanization and industrialization has shrunken agriculture land and thus, affected demand vs. food supply ratio. Exploitation and manipulation of beneficial bacteria-plant association can be most effective and eco-friendly to enhance plant growth and productivity in sustainable manner. Various bioinoculants tested in several crops are found to be effective under laboratory conditions but showed inconsistencies in field studies. Therefore, present study aimed to adopt a systematic approach from lab to natural conditions for providing better and stable bioinoculants. In addition, to broaden the application of selected bacterial inoculants, cross infection studies were performed. Ability of endophytic bacteria to promote growth of pearl millet plant was tested at laboratory, greenhouse and field condition. They were screened and sorted out for various levels on the basis of various plant growth parameters. Bioinoculants of field trial were inoculated to wheat plants to confirm their endophytic nature and cross-infection capability using species-specific PCR. Most of the bio-inoculants promoted plant growth better in sterilized than unsterilized soil. In microcosm studies, some of the isolates showed synergistic effect on plant growth. In field studies, PM10461 was the best and consistent inoculant followed by PM9404 and PM9426. Cross-infection capability and endophytic colonization of these strains in wheat broaden the application to other crops. In future studies, various formulations (consortia) which showed better plant growth promotion in microcosm studies, can be tested at field level and efficient inoculants can be converted into commercial biofertilizer for wide usage and industrial production.

Plant-Microbe Partnerships for Enhanced Biodegradation of Polychlorinated Biphenyls

Abstract: Our modern civilization rests on synthetic organic compounds Some of these compounds which have become indispensable for human society are termed as persistent organic pollutants (POPs) They enter into the food chain where they bioaccumulate in fat tissues of organisms at various trophic levels and usually biomagnify the physiological effects at higher levels resulting in severe health hazards Civil and mechanical engineering remediation methods deployed to clean such environmental contaminants have serious shortcomings of being expensive and environmentally invasive Thus, there is an urgent need to search for alternative strategy(ies) which does not suffer from abovementioned shortcomings The past decade has witnessed a momentum in the use of plants and its associated microflora partnerships as an alternative option Plant and associated bacteria interact synergistically to lower down the levels of contaminants present in the immediate vicinity of root systems Plants modulate root secretions and exudations to orchestrate recruitment of catabolically active bacteria in their rhizosphere This recruitment in turn biodegrades contaminant(s) present in the rhizospheric soil by bacterial communities which subsequently reduces environmental stress on the plant Thus, it is highly recommended to explore novel plant microbe pairs naturally operating in organic contaminated ecosystems and study the members of microbial communities to get more insight into a phenomenon of phytoremediation so that the technology may be optimized and extended from lab to land The present review highlights the synergistic effects of plant-microbe interactions in the phytoremediation of organic pollutants with special reference to polychlorinated biphenyls (PCBs) Also, the state-of-the-art techniques used to study microbial diversity within PCB contaminated environments are discussed

Novel Grinding Synthesis of Pyranopyrazole Analogues and Their Evaluation as Antimicrobial Agents

Abstract: The paper describes the results of a new four-component synthesis of pyranopyrazole heterocycles by solvent-free one-pot grinding of malononitrile, hydrazine, ethyl acetoacetate, and various aldehydes in the presence of a base. The reaction proceeded smoothly at room temperature with good yields in very short reaction time. The synthesised compounds were evaluated for their in vitro antibacterial activity against three different bacterial and three different fungal strains. The highlight of this work is that the synthesis was activity-driven. The brief SAR correlation found that the tested compounds showed better activity against fungal strains.

Effective global tobacco control in the next decade

Abstract: In the decade since the World Health Organization (WHO) adopted the Framework Convention on Tobacco Control, more than 170 countries have signed the agreement.[1][1] The framework, and its specific protocols, has mobilized nearly every country to control tobacco more stringently and to report on

Disease Control Priorities, Third Edition

Abstract: From its inception, the Disease Control Priorities series has focused attention on delivering efficacious health interventions that can result in dramatic reductions in mortality and disability at relatively modest cost The approach has been multidisciplinary, and the recommendations have been evidence-based, scalable, and adaptable in multiple settings Better and more equitable health care is the shared responsibility of governments and international agencies, public and private sectors, and societies and individuals, and all of these partners have been involved in the development of the series Volume 3, Cancer, presents the complex patterns of cancer incidence and death around the world and evidence on effective and cost-effective ways to control cancers The DCP3 evaluation of cancer will indicate where cancer treatment is ineffective and wasteful, and offer alternative cancer care packages that are cost-effective and suited to low-resource settings

Creating a pandemic of health: Big ideas for a new initiative on global health equity and innovation

Abstract: Outcomes & Evaluation: The outlines and content of all modules have been finalized, and online media and material is currently being constructed. In order to prepare for online release, the modules will initially be piloted by global health experts. Once modules have been released online and are available to all residencies, data can be collected tracking completion, performance, and corresponding ACGME milestone levels for residents and medical students. Going Forward: The modules will be piloted in early 2015; the final product will be available soon thereafter. Input from participants and program directors will be gathered to track use, efficacy, and impact on training and to inform future improvements. Funding: Partially funded by a grant from the American College of Emergency Physicians. Abstract #: 02ETC041

HPV‐avertable cancer risks in India: A pooled analysis of 9 observational studies

Abstract: Dear Sir, We read with great interest the article by Michaud et al. “Highrisk HPV types and head and neck cancer.” Their research presents the associations between infections with high-risk HPV subtypes and head and neck cancer risk in the US. In addition to HPV16, HPV18/33, and HPV52 emerged as important risk factors for oropharyngeal and oral cancers, respectively. Oral cancer is the most common form of malignant cancers in the Indian subcontinent; it accounts for one-third of the global burden of oral cancer incidence and mortality. Despite extensive improvements in diagnosis and therapy in recent decades, the prognosis of oral cancers remains poorly understood. In the Indian sub-populations, oral cancer is primarily associated with commonly known risk factors such as tobacco chewing and bidi or cigarette smoking. However, additional risk factors may be at play, as suggested by the incidence of oral cancer in approximately 20% of the patients, who develop this malignancy without a definite etiology of risk factors. Similarly, cervical cancer in India constitutes a quarter of the global burden with 132,000 new cases and 74,000 deaths every year. It is the leading malignancy in our region with age standardized rates of 14.3 and 7.7 per 100,000 individuals from urban and rural areas, respectively. Mixed claims have been made regarding the association of HPV infection with the development of both cervical and oral cancers in different regions of India. In addition, limited information is available on the distribution of HPV types in the country. This makes it important to further explore the association between HPV types, and cervical and oral cancers. Based on the existing literature from the Indian context, we conducted a meta-analysis on the association of HPV and high-risk HPV types on head and neck, and cervical cancer