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1.
medRxiv ; 2023 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-37066213

RESUMO

Background: Tracking the emergence and spread of antimalarial drug resistance has become critical to sustaining progress towards the control and eventual elimination of malaria in South Asia, especially India. Methods: An amplicon sequencing protocol was used for high-throughput molecular surveillance of antimalarial drug resistance in a total of 158 isolates at three sites in India: Chennai, Nadiad and Rourkela. Five genes of the Plasmodium falciparum implicated in antimalarial resistance were investigated here; Pfcrt for chloroquine resistance, Pfdhfr for pyrimethamine resistance, Pfdhps for sulfadoxine resistance, Pfk13 for artemisinin resistance and Pfmdr1 for resistance to multiple antimalarials. Results: Mutations in the propeller domain of PfK13 were observed in two samples only, however these mutations are not validated for artemisinin resistance. A high proportion of parasites from the P. falciparum dominant site Rourkela showed wild-type Pfcrt and Pfdhfr haplotypes, while mutant Pfcrt and Pfdhfr haplotypes were fixed at the P. vivax dominant sites Chennai and Nadiad. The wild-type PfDHPS haplotype was predominant across all study sites. Finally, we observed the largest proportion of suspected multi-clonal infections at Rourkela, which has the highest transmission of P. falciparum among our study sites. Conclusion: This is the first simultaneous high-throughput next generation sequencing of five complete P. falciparum genes from infected patients in India.

2.
J Biomol Struct Dyn ; 40(15): 6880-6888, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-33627036

RESUMO

Aldose reductase (AR) is an NADPH-dependent oxidoreductase that is well-studied for its role in Diabetes Mellitus. Glutathione conjugated aldehydes are efficiently catalysed by AR. We have employed molecular dynamics simulations to investigate the dynamics of a glutathione analog, γ-glutamyl-S-(1,2-di-carboxyethyl)-cysteinyl-glycine (DCEG), into the binding pocket of AR. Study revealed that backbone nitrogens of Ala-299 and Leu-300 form a tiny pocket gated by thiol group of Cys-298. The glycine moiety of DCEG was able to displace the thiol group of Cys-298 to make hydrogen bond interactions with backbone of Ala-299, Leu-300, and Leu-301. This study provides the details of the dynamic interactions of DCEG in the binding pocket of AR, and shall aid in the design/discovery of differential inhibitors against AR.Communicated by Ramaswamy H. Sarma.


Assuntos
Aldeído Redutase , Glutationa , Aldeído Redutase/química , Aldeídos/química , Aldeídos/metabolismo , Glutationa/metabolismo , Modelos Moleculares , Compostos de Sulfidrila
3.
Cell Microbiol ; 23(5): e13311, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33486886

RESUMO

The spread of infection is directly determined by the ability of a pathogen to invade and infect host tissues. The process involves adherence due to host-pathogen interactions and traversal into deeper tissues. Mycobacterium tuberculosis (Mtb) primarily infects the lung but is unique in its ability to infect almost any other organ of the human host including immune privileged sites such as the central nervous system (CNS). The extreme invasiveness of this bacterium is not fully understood. In the current study, we report that cell surface Mtb glyceraldehyde-3-phosphate dehydrogenase (GAPDH) functions as a virulence factor by multiple mechanisms. Firstly, it serves as a dual receptor for both plasminogen (Plg) and plasmin (Plm). CRISPRi-mediated silencing of this essential enzyme confirmed its role in the recruitment of Plg/Plm. Our studies further demonstrate that soluble GAPDH can re-associate on Mtb bacilli to promote plasmin(ogen) recruitment. The direct association of plasmin(ogen) via cell surface GAPDH or by the re-association of soluble GAPDH enhanced bacterial adherence to and traversal across lung epithelial cells. Furthermore, the association of GAPDH with host extracellular matrix (ECM) proteins coupled with its ability to recruit plasmin(ogen) may endow cells with the ability of directed proteolytic activity vital for tissue invasion.


Assuntos
Adesinas Bacterianas/metabolismo , Fibrinolisina/metabolismo , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Mycobacterium tuberculosis/enzimologia , Mycobacterium tuberculosis/patogenicidade , Plasminogênio/metabolismo , Fatores de Virulência/metabolismo , Células A549 , Adesinas Bacterianas/genética , Aderência Bacteriana , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Gliceraldeído-3-Fosfato Desidrogenases/genética , Humanos , Ligação Proteica , Virulência , Fatores de Virulência/genética
4.
J Environ Manage ; 272: 111067, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32736232

RESUMO

Subsurface denitrification plays a key role in the reduction or 'attenuation' of nitrate contamination of groundwater and surface waters. We investigated subsurface denitrification characteristics in the vadose zone and shallow groundwater at four sites under pastoral farming in the Manawatu River catchment, located in the lower part of North Island, New Zealand. The denitrification potential of the vadose zone was determined by the laboratory incubation assays measuring the denitrifying enzyme activity (DEA) in soil samples collected from different soil horizons (up to 2.1 m below ground surface), whereas denitrification rates in shallow groundwaters were measured in situ by single-well, push-pull tests conducted in piezometers installed at multiple depths at the study sites. Soils and underlying geology, defining hydrogeologic settings, appear to influence the spatial variability of subsurface denitrification characteristics at the study sites. Where the vadose zone is thin and composed of coarse-textured soils, percolation of nitrate was evident in observed high nitrate-nitrogen concentrations (>5 mg L-1) in oxic and young shallow groundwaters, but low nitrate-nitrogen concentrations (<0.05 mg L-1) were observed in the reduced shallow groundwater found underneath the fine textured soils and/or a thick vadose zone. This was confirmed by the push-pull tests measuring denitrification rates from 0.08 to 1.07 mg N L-1 h-1 in the reduced shallow groundwaters (dissolved oxygen or DO < 0.5 mg L-1), while negligible in the oxic groundwaters (DO > 5 mg L-1) found at the study sites. These contrasting subsurface denitrification characteristics determine the ultimate delivery of nitrate losses from agricultural soils to receiving waters, where the fine textured thick vadose zone and reducing groundwater conditions offer nitrate reduction in the subsurface environment.


Assuntos
Água Subterrânea , Poluentes Químicos da Água/análise , Agricultura , Desnitrificação , Monitoramento Ambiental , Nova Zelândia , Nitratos/análise , Nutrientes
5.
Virulence ; 11(1): 730-738, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32490754

RESUMO

The mounting evidence supporting the capacity of Plasmodium vivax to cause severe disease has prompted the need for a better characterization of the resulting clinical complications. India is making progress with reducing malaria, but epidemics of severe vivax malaria in Gujarat, one of the main contributors to the vivax malaria burden in the country, have been reported recently and may be the result of a decrease in transmission and immune development. Over a period of one year, we enrolled severe malaria patients admitted at the Civil Hospital in Ahmedabad, the largest city in Gujarat, to investigate the morbidity of severe vivax malaria compared to severe falciparum malaria. Patients were submitted to standard thorough clinical and laboratory investigations and only PCR-confirmed infections were selected for the present study. Severevivax malaria (30 patients) was more frequent than severe falciparum malaria (8 patients) in our setting, and it predominantly affected adults (median age 32 years, interquartile range 22.5 years). This suggests a potential age shift in anti-malarial immunity, likely to result from the recent decrease in transmission across India. The clinical presentation of severe vivax patients was in line with previous reports, with jaundice as the most common complication. Our findings further support the need for epidemiological studies combining clinical characterization of severe vivax malaria and serological evaluation of exposure markers to monitor the impact of elimination programmes.


Assuntos
Malária Vivax/epidemiologia , Índice de Gravidade de Doença , Adolescente , Adulto , Antimaláricos/uso terapêutico , Criança , Pré-Escolar , Feminino , Humanos , Índia/epidemiologia , Malária Vivax/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Plasmodium vivax/patogenicidade , Estudos Prospectivos , Adulto Jovem
6.
Ground Water ; 58(4): 622-637, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31605495

RESUMO

Groundwater flow and contaminant transport are strongly influenced by hydrogeological spatial variation. Understanding the textural heterogeneity of aquifer and aquitard units is critical for predicting preferential flow pathways, but is often hindered by sparse hydrogeological data, widely spaced data points, and complex stratigraphy. Here, we demonstrate the application of a relatively new air permeameter technology, providing a cost-effective, rapid alternative for characterizing hydrostratigraphic units in the field. The aim of this research is to (1) characterize the variation of saturated hydraulic conductivity across shallow-marine hydrostratigraphic units of the Whanganui Basin, New Zealand, and (2) assess the variation of saturated hydraulic conductivity within individual hydrostratigraphic units and relate these changes to facies and depositional environments. Results suggest heterogeneity within fine-grained aquitard units is controlled by bioturbation, whereby burrowing, ingestion and defecation results in grain size segregation and differential micrite cementation. Coarse-grained heterolithic aquifer facies display sharp changes in permeability across planar to cross-bedded sets, related to current and wave energy fluctuations within shallow-marine depositional settings. Bedding plane orientation creates high permeability zones that promotes down dip subsurface flow. Down dip gradation of coarse-grained nearshore facies into fine-grained shelf facies along the paleo shoreline-shelf transect is suggested to promote lateral and vertical groundwater flow within the basin fill. Air permeameter techniques have potential for application within groundwater basins around the world, providing datasets that facilitate greater understanding of groundwater systems, informing practices and policies for targeted water quality management.


Assuntos
Água Subterrânea , Condutividade Elétrica , Nova Zelândia , Movimentos da Água , Qualidade da Água
7.
Sci Rep ; 9(1): 17095, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31745160

RESUMO

Malaria in India, while decreasing, remains a serious public health problem, and the contribution of submicroscopic and asymptomatic infections to its persistence is poorly understood. We conducted community surveys and clinic studies at three sites in India differing in their eco-epidemiologies: Chennai (Tamil Nadu), Nadiad (Gujarat), and Rourkela (Odisha), during 2012-2015. A total of 6,645 subject blood samples were collected for Plasmodium diagnosis by microscopy and PCR, and an extensive clinical questionnaire completed. Malaria prevalence ranged from 3-8% by PCR in community surveys (24 infections in Chennai, 56 in Nadiad, 101 in Rourkela), with Plasmodium vivax dominating in Chennai (70.8%) and Nadiad (67.9%), and Plasmodium falciparum in Rourkela (77.3%). A proportional high burden of asymptomatic and submicroscopic infections was detected in community surveys in Chennai (71% and 71%, respectively, 17 infections for both) and Rourkela (64% and 31%, 65 and 31 infections, respectively). In clinic studies, a proportional high burden of infections was identified as submicroscopic in Rourkela (45%, 42 infections) and Chennai (19%, 42 infections). In the community surveys, anemia and fever were significantly more common among microscopic than submicroscopic infections. Exploratory spatial analysis identified a number of potential malaria hotspots at all three sites. There is a considerable burden of submicroscopic and asymptomatic malaria in malarious regions in India, which may act as a reservoir with implications for malaria elimination strategies.


Assuntos
Malária/epidemiologia , Malária/transmissão , Microscopia/métodos , Plasmodium/patogenicidade , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Índia/epidemiologia , Lactente , Malária/parasitologia , Masculino , Pessoa de Meia-Idade , Plasmodium/classificação , Prevalência , Adulto Jovem
8.
F1000Res ; 8: 564, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31723418

RESUMO

Background: Human aldose reductase (hAR) is the first and rate-limiting enzyme of the polyol pathway. For the development of secondary complications of diabetes in chronic hyperglycemic conditions, one of the critical factors is the increased flux of glucose through the polyol pathway.  Due to this clinical implication, hAR attracted considerable attention from the drug discovery perspective. In spite of extensive characterization in the context of biochemical and structural aspects, we know very little about the unfolding behavior of hAR. This study reports equilibrium unfolding studies of hAR. Methods: We carried out thermal denaturation and chemical-induced equilibrium unfolding studies of hAR monitored by circular dichroism and fluorescence spectroscopy.  Results: Thermal denaturation studies presented a classical picture of two-state unfolding from native to the denatured state. The data was used to derive thermodynamic parameters and study the thermostability of hAR. Chemical induced equilibrium unfolding studies led us to discover an intermediate state, which gets populated at 3.5-4.0 M and 0.7-2.0 M of urea and GuHCl, respectively. Thermodynamic parameters derived from chemical-induced unfolding are in agreement with those obtained from thermal denaturation of hAR. Conclusion: This study revealed that aldose reductase unfolds from native to the unfolded state via an intermediate. Assessment of the thermodynamic stability of native, intermediate, and unfolded states shows that significant energy barriers separate these states, which ensures the cooperativity of unfolding. As hAR functions in cells that are under osmotic and oxidative stress, these in vitro findings may have implications for its native conformation under the physiological state.


Assuntos
Aldeído Redutase , Dobramento de Proteína , Aldeído Redutase/fisiologia , Guanidina , Humanos , Concentração de Íons de Hidrogênio , Desnaturação Proteica
9.
Heliyon ; 5(9): e02483, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31687577

RESUMO

Ayurveda based nanomaterials are recently conceptualized phenomena for biomedical applications especially for imaging and treatment of in vitro cancer cell. Wide range florescent (blue to red emission) quantum dots are versatile materials for imaging and sensing applications. Various procedures and precursors of fluorescent carbon quantum dots (CQDs) are well established and documented in the literature. However, expensive precursors and production, and time consuming process limit their economical design that need to be addressed. Herein, we report a cost effective simple route for fluorescent CQDs by using affordable ayurvedic plant's precursors such as Azadirachta Indica, OcimumTenuiflorum and Tridax Procumbens. Obtained quantum dots from ayurvedic plant leaves namely CQDs-1 (AzadirachtaIndica), CQDs-2 (OcimumTenuiflorum) and CQDs-3 (TridaxProcumbens) showed homogeneous size distribution (∼6-12 nm) and green fluorescent nature, average photo-stability, biocompatibility (more than 85 %), cancer cell imaging and promising phototherapy for cancer and bacterial cell lines.

10.
Front Public Health ; 7: 239, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31544099

RESUMO

In the past 200 years, urban spaces have been imagined as neatly laid out, well-planned, sanitised and civilised places of dense human habitation with regulated economic activity, where political power, financial capital, the frontiers of knowledge and technology thrive. This has been the urban planners dream, even while it does not reflect the full reality, whether of cities in the LMICs or the HICs. In the face of such homogenising visions arising from Euro-American models, formal urban systems fail to provide adequately for residents' needs, who then carve out their own resources and processes for meeting them, largely within the domain of urban "informality." While large part of literature presents urban informality as reflected in the slum, others have shown how it is found in relation to all classes (1). The concept of informality has largely been applied to the core dimensions of economic life of the city. Applied to people's "ways of life," intermingling of the formal and informal becomes distinctly evident in everyday practices in locations such as the peri-urban, and in activities such as health care. This paper opens up the sphere of health care for urban planning that has, in recent decades, left it largely untouched. It uses data from a rapid assessment of health seeking behaviour of three socioeconomic groups-the middle class, slum-dwellers, and homeless- in Delhi, the capital city of India. The findings, relevant beyond the specific location, reveal that people of all sections resort to myriad informal arrangements for their health care, challenging the dominant connotation of the formal-informal denoting a legitimate-illegitimate dichotomy. This provides potential directions to bridge the formal-informal divide, to re-configure urban planning towards more sustainable futures with plural visions of land use and urban greening for healthier urban conditions and for health care provisioning. The analysis posits that, besides the economic and political relations shaping the formal and informal, the politics of knowledge must be factored in if the informal has to be adequately understood for building sustainable futures.

11.
J Family Med Prim Care ; 8(6): 1971-1975, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31334164

RESUMO

BACKGROUND: In the world, helminthiasis is the major public health problem in school-age children. More than 60 million school-age children live in intensively transmitted areas and they need immediate treatment and preventive interventions. METHODOLOGY: The study was conducted in the rural government schools of Block Beri, District Jhajjar (Haryana), India, and the study was descriptive and cross-sectional in design. The study recruited 300 school-going children in the age group of 6-10 years. RESULTS: In this study, the mean age of subjects was 7.68 ± 1.467 years and prevalence of soil-transmitted helminths was 28.7%. The association between practice of hand washing and practice of washing fruits and vegetables with helminthic children were found statistically significant. CONCLUSION AND RECOMMENDATION: Impart health education among community through primary care physician about wash hands before eating food and after defecation, washed thoroughly raw and uncooked food before eating.

13.
Environ Manage ; 62(4): 740-755, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29947967

RESUMO

Altered hydrological, sediment, and nutrient regimes can lead to dramatic increases in periphyton abundance in rivers below impoundments. Flushing flows are a commonly adopted strategy to manage the excess periphyton that can accumulate, but in practice they often prove ineffective. Designing hydrological regimes that include flushing flows may be overlooking key processes in periphyton removal, particularly the role of abrasion and molar action induced by substrate movement. Setting flow targets which aim to initiate substrate movement are likely to improve periphyton removal, but an understanding of the site-specific thresholds for substrate entrainment and periphyton removal is required. Despite decades of entrainment studies accurate and consistent measurement and prediction of substrate entrainment remains elusive, making it challenging to study the relationship between substrate movement and periphyton removal, and to set flow targets. This paper makes a case for using substrate entrainment and transport thresholds as the target metric for flushing flows to manage excess periphyton accrual. This paper critically reviews the determinants of periphyton accrual and associated management methods. This paper also aims to provide a reference for interdisciplinary research on periphyton removal by summarising the geomorphic and hydraulic literature on methods for estimating and measuring substrate entrainment and transport. This will provide a basis for ecologists to identify tools for quantifying entrainment and transport thresholds so they are better placed to explore the direct linkages between phases of sediment transport and periphyton accrual. These linkages need to be identified in order for river managers to set effective flushing flow targets.


Assuntos
Conservação dos Recursos Hídricos/métodos , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Perifíton , Rios/química , Movimentos da Água , Hidrologia
14.
Environ Monit Assess ; 190(2): 78, 2018 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-29327177

RESUMO

Better management of water quality in streams, rivers and lakes requires precise and accurate estimates of different contaminant loads. We assessed four sampling frequencies (2 days, weekly, fortnightly and monthly) and five load calculation methods (global mean (GM), rating curve (RC), ratio estimator (RE), flow-stratified (FS) and flow-weighted (FW)) to quantify loads of nitrate-nitrogen (NO3--N), soluble inorganic nitrogen (SIN), total nitrogen (TN), dissolved reactive phosphorus (DRP), total phosphorus (TP) and total suspended solids (TSS), in the Manawatu River, New Zealand. The estimated annual river loads were compared to the reference 'true' loads, calculated using daily measurements of flow and water quality from May 2010 to April 2011, to quantify bias (i.e. accuracy) and root mean square error 'RMSE' (i.e. accuracy and precision). The GM method resulted into relatively higher RMSE values and a consistent negative bias (i.e. underestimation) in estimates of annual river loads across all sampling frequencies. The RC method resulted in the lowest RMSE for TN, TP and TSS at monthly sampling frequency. Yet, RC highly overestimated the loads for parameters that showed dilution effect such as NO3--N and SIN. The FW and RE methods gave similar results, and there was no essential improvement in using RE over FW. In general, FW and RE performed better than FS in terms of bias, but FS performed slightly better than FW and RE in terms of RMSE for most of the water quality parameters (DRP, TP, TN and TSS) using a monthly sampling frequency. We found no significant decrease in RMSE values for estimates of NO3-N, SIN, TN and DRP loads when the sampling frequency was increased from monthly to fortnightly. The bias and RMSE values in estimates of TP and TSS loads (estimated by FW, RE and FS), however, showed a significant decrease in the case of weekly or 2-day sampling. This suggests potential for a higher sampling frequency during flow peaks for more precise and accurate estimates of annual river loads for TP and TSS, in the study river and other similar conditions.


Assuntos
Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , Monitoramento Ambiental/estatística & dados numéricos , Lagos , Nova Zelândia , Nitratos/análise , Nitrogênio/análise , Fósforo/análise , Rios/química , Qualidade da Água/normas
15.
Indian J Surg ; 79(4): 349-353, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28827911

RESUMO

Short bowel syndrome (SBS), one of the commonest types of intestinal failure, usually secondary to extensive bowel resection, traditionally has been associated with a high mortality rate and hence a big challenge for the treating surgeons. It requires comprehensive clinical care to minimise the morbidities and mortality associated with the condition. We report a retrospective review of a series of seven patients with SBS, who presented at our surgical emergency within a period of 1 year and their outcome so as to encourage others in managing such a challenge with more positive mindsets. A retrospective analysis of seven patients with SBS admitted from January 2014 to January 2015 with a follow-up of 1 year has been done in terms of their demographic characteristics, underlying pathology and clinical outcome. A rising incidence of SBS in the younger age group (71.4%) has been observed in this analysis. Majority of patients (57.1%) had mesenteric ischemia as the underlying cause followed by each case of small bowel volvulus, internal herniation and blunt trauma abdomen. A discharge rate of 71.4% and mortality rate of 28.5% were observed. With this analysis, we believe that SBS is no more an uncommon condition. A structured clinical approach, timely surgical intervention and multidisciplinary postoperative management are essential for managing such frail patients to achieve best possible results. This will encourage others in managing such a critically challenged condition with a more positive approach and thus beneficial for both the patients and the treating surgeon.

16.
J Environ Manage ; 197: 476-489, 2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-28412619

RESUMO

A sound understanding of the effects of hydrogeological factors on loss, transport and transformation of farm nutrients is essential for predicting their impacts on ecosystem health of receiving waters. We assessed the potential of groundwater to attenuate nitrate through denitrification, and the distribution of this potential across the Tararua Groundwater Management Zone (GWMZ) in the Manawatu River catchment, New Zealand. We combined a number of methods in an unprecedented manner to confirm findings and obtain supporting evidence for the features that determine the subsurface denitrification characteristics. Our results showed that the denitrification characteristics of groundwater varied considerably in the Tararua GWMZ. The southern part of the Tararua GWMZ contained mainly oxic groundwater with low potential to denitrify, whereas the middle and northern parts of the Tararua GWMZ contained reduced groundwater with high denitrification potential. The hydrogeological features that influence denitrification potential in groundwater were identified as soil texture and drainage class, and the aquifer material or rock type. Low dissolved oxygen levels and nitrate concentrations were found in groundwater where the combinations of soil and rock types had poor drainage characteristics as opposed to higher concentrations in groundwater under well-drained soils and rocks (e.g. gravels). Intensive pastoral farming over well-drained soils and rocks showed high nitrate concentration in groundwater. This spatial variability in denitrification potential of groundwater offers a targeted management of nutrients runoff and leaching from pastoral lands to reduce their impacts on receiving surface waters.


Assuntos
Desnitrificação , Poluentes Químicos da Água , Monitoramento Ambiental , Água Subterrânea , Nova Zelândia , Nitratos , Rios
17.
Mol Cell Biochem ; 430(1-2): 21-30, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28190170

RESUMO

In order to understand the molecular basis of cold adaptation, we have used directed evolution to transform a thermophilic lipase LipR1 into its psychrophilic counterpart. A single round of random mutagenesis followed by screening for improved variants yielded a mutant with single-point mutation LipR1M1 (S130T), with optimum activity at 20 °C. Its activity at 50 °C is only 20% as compared to wild type (100%). It showed catalytic rate constant (k cat) 3 times higher and a catalytic efficiency (k cat/K m) 4 times that of wild type. Circular dichroism and fluorescence studies also supported our observation of mutant structural flexibility. Structure analysis using homology models showed that Threonine 130 is exposed to solvent and has lost H-bond interaction with neighboring amino acid, thereby increasing flexibility of this lipase structure.


Assuntos
Evolução Molecular Direcionada , Lipase/química , Lipase/genética , Mutação Puntual , Estabilidade Enzimática/genética , Temperatura Alta
18.
Int J Med Microbiol ; 307(2): 126-138, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28161108

RESUMO

Tuberculosis, one of the leading cause of death from infectious diseases, is caused by Mycobacterium tuberculosis. The genome of M. tuberculosis has been sequenced and nearly 40% of the whole genome sequence was categorized as hypothetical. Rv0774c was annotated as membrane exported hypothetical protein in TB database. In silico analysis revealed that Rv0774c is a paralog of PE-PGRS multi gene family with 100 aa N-terminal domain similar to PE domain of PE-PGRS proteins. Its C-terminal domain is quite different from PGRS domain, having characteristic lipase signature GXSXG & HG and catalytic residues predicted for lipolytic activity. Therefore, DNA coding for Rv0774c (303 aa), its N-terminal (1-100 aa) and C- terminal domain (100-303 aa) were separately cloned from M. tuberculosis and were over expressed in E. coli. Rv0774c gene and its C-terminal lipolytic domain preferably hydrolyzed short chain esters. Though no enzyme activity was observed in N-terminus PE like domain, it was demonstrated to enhance the thermostability of full length Rv0774c. Tetrahydrolipstatin inhibited the enzyme activity and predicted catalytic residues (Ser-185, Asp-255 and His-281) were confirmed by site directed mutagenesis. Rv0774c was secreted out in culture media by M. tuberculosis and was up-regulated in iron limiting conditions. Treatment of THP-1 cells with rRv0774c resulted in a decline in the LPS induced production of NO and expression of iNOS. rRv0774c treated THP-1 cells also showed an enhanced expression of IL-10 and TLR2. On contrary, it suppressed the LPS induced production of IL-12, chemokines MCP-1 and IL-8. Rv0774c inhibited the LPS induced phosphorylation of p38. These observations suggested that Rv0774c could modulate the pro-inflammatory immune response to support intracellular survival of the mycobacterium.


Assuntos
Proteínas de Bactérias/metabolismo , Citocinas/antagonistas & inibidores , Esterases/metabolismo , Terapia de Imunossupressão , Mycobacterium tuberculosis/enzimologia , Mycobacterium tuberculosis/fisiologia , Receptor 2 Toll-Like/antagonistas & inibidores , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Domínio Catalítico , Linhagem Celular , Clonagem Molecular , Análise Mutacional de DNA , Estabilidade Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Esterases/química , Esterases/genética , Expressão Gênica , Interações Hospedeiro-Patógeno , Humanos , Lipopolissacarídeos/metabolismo , Monócitos/efeitos dos fármacos , Monócitos/imunologia , Mutagênese Sítio-Dirigida , Especificidade por Substrato , Temperatura
19.
PLoS Negl Trop Dis ; 11(1): e0005323, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28118367

RESUMO

Understanding naturally acquired immune responses to Plasmodium in India is key to improving malaria surveillance and diagnostic tools. Here we describe serological profiling of immune responses at three sites in India by probing protein microarrays consisting of 515 Plasmodium vivax and 500 Plasmodium falciparum proteins with 353 plasma samples. A total of 236 malaria-positive (symptomatic and asymptomatic) plasma samples and 117 malaria-negative samples were collected at three field sites in Raurkela, Nadiad, and Chennai. Indian samples showed significant seroreactivity to 265 P. vivax and 373 P. falciparum antigens, but overall seroreactivity to P. vivax antigens was lower compared to P. falciparum antigens. We identified the most immunogenic antigens of both Plasmodium species that were recognized at all three sites in India, as well as P. falciparum antigens that were associated with asymptomatic malaria. This is the first genome-scale analysis of serological responses to the two major species of malaria parasite in India. The range of immune responses characterized in different endemic settings argues for targeted surveillance approaches tailored to the diverse epidemiology of malaria across the world.


Assuntos
Anticorpos Antiprotozoários/sangue , Formação de Anticorpos , Malária Falciparum/sangue , Malária Vivax/sangue , Adolescente , Adulto , Idoso , Antígenos de Protozoários/imunologia , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Índia , Malária Falciparum/epidemiologia , Malária Falciparum/imunologia , Malária Vivax/epidemiologia , Malária Vivax/imunologia , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Plasmodium falciparum/imunologia , Plasmodium vivax/imunologia , Análise Serial de Proteínas , Adulto Jovem
20.
J Family Med Prim Care ; 6(3): 554-557, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29417007

RESUMO

BACKGROUND: Globally, approximately, one billion people lack access to safe drinking water and 1.59 million deaths per year are because of contaminated water, primarily in children age <5 years. WHO reported that more than 90% of diarrhea cases can be prevented by enhancing the availability of clean water and improving hygiene measures. METHODOLOGY: The study was conducted in an urban slum of Rohtak district. Investigator interviewed the mothers at their home having children age less than 5 years using study tools in their vernacular language. STUDY DESIGN: The study was a community based epidemiological study with cross-sectional design. STUDY PARTICIPANTS: 400 mothers having children less than 5 years. RESULTS: Most of subjects (59%) were in the age group of 15-25 years followed by in 25-35 years. One third of subjects belonged to upper caste and 29% of subjects from backward class. The study found that 80% of mother store water in earthen pitcher followed by plastic jug (14%). 78% of mothers said that their source of drinking water was tap while 12% had Hand pump. 83.5% of subjects said that they drink water as such ie without filtering, boiling or chlorination. CONCLUSION AND RECOMMENDATIONS: The study concluded that the prevalence of diarrhea is more among children < 5 years this is because of poor knowledge, poor attitude and inadequate storage water practices of water. The study recommends creating awareness how to diminish contamination of water at household level, creating community groups for women to learn about treatment of water at household level.

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