Relative contribution of diet and physical activity to increased adiposity among rural to urban migrants in India: A cross-sectional study.

BACKGROUND: In common with many other low- and middle-income countries (LMICs), rural to urban migrants in India are at increased risk of obesity, but it is unclear whether this is due to increased energy intake, reduced energy expenditure, or both. Knowing this and the relative contribution of specific dietary and physical activity behaviours to greater adiposity among urban migrants could inform policies for control of the obesity epidemic in India and other urbanising LMICs. In the Indian Migration Study, we previously found that urban migrants had greater prevalence of obesity and diabetes compared with their nonmigrant rural-dwelling siblings. In this study, we investigated the relative contribution of energy intake and expenditure and specific diet and activity behaviours to greater adiposity among urban migrants in India. METHODS AND FINDINGS: The Indian Migration Study was conducted between 2005 and 2007. Factory workers and their spouses from four cities in north, central, and south of India, together with their rural-dwelling siblings, were surveyed. Self-reported data on diet and physical activity was collected using validated questionnaires, and adiposity was estimated from thickness of skinfolds. The association of differences in dietary intake, physical activity, and adiposity between siblings was examined using multivariable linear regression. Data on 2,464 participants (median age 43 years) comprised of 1,232 sibling pairs (urban migrant and their rural-dwelling sibling) of the same sex (31% female) were analysed. Compared with the rural siblings, urban migrants had 18% greater adiposity, 12% (360 calories/day) more energy intake, and 18% (11 kilojoules/kg/day) less energy expenditure (P < 0.001 for all). Energy intake and expenditure were independently associated with increased adiposity of urban siblings, accounting for 4% and 6.5% of adiposity difference between siblings, respectively. Difference in dietary fat/oil (10 g/day), time spent engaged in moderate or vigorous activity (69 minutes/day), and watching television (30 minutes/day) were associated with difference in adiposity between siblings, but no clear association was observed for intake of fruits and vegetables, sugary foods and sweets, cereals, animal and dairy products, and sedentary time. The limitations of this study include a cross-sectional design, systematic differences in premigration characteristics of migrants and nonmigrants, low response rate, and measurement error in estimating diet and activity from questionnaires. CONCLUSIONS: We found that increased energy intake and reduced energy expenditure contributed equally to greater adiposity among urban migrants in India. Policies aimed at controlling the rising prevalence of obesity in India and potentially other urbanising LMICs need to be multicomponent, target both energy intake and expenditure, and focus particularly on behaviours such as dietary fat/oil intake, time spent on watching television, and time spent engaged in moderate or vigorous intensity physical activity.

Combining host-derived biomarkers with patient characteristics improves signature performance in predicting tuberculosis treatment outcomes.

Tuberculosis (TB) is a global health concern. Treatment is prolonged, and patients on anti-TB therapy (ATT) often experience treatment failure for various reasons. There is an urgent need to identify signatures for early detection of failure and initiation of a treatment switch.We investigated how gene biomarkers and/or basic patient characteristics could be used to define signatures for treatment outcomes in Indian adult pulmonary-TB patients treated with standard ATT. Using blood samples at baseline, a 12-gene signature combined with information on gender, previously-diagnosed TB, severe thinness, smoking and alcohol consumption was highly predictive of treatment failure at 6 months. Likewise a 4-protein biomarker signature combined with the same patient characteristics was almost as highly predictive of treatment failure. Combining biomarkers and basic patient characteristics may be useful for predicting and hence identification of treatment failure at an early stage of TB therapy.

Identification of subclinical tuberculosis in household contacts using exposure scores and contact investigations.

BACKGROUND: The goal of tuberculosis elimination put forward in the End TB Strategy prioritizes diagnosis and treatment of incipient and subclinical TB, recently defined by key stakeholders as "asymptomatic, early pre-clinical disease during which pathology evolves". Regarded as indicative of a high risk of TB progression, considerable efforts have been made to identify these cases through exploration of biomarkers. The present study aimed to evaluate simple scoring systems for TB exposure as screening tools for subclinical TB, the only identifiable of the incipient and subclinical disease states, in a contact investigation (CI) setting of low HIV-prevalence. METHODS: Nested within a large prospective study in household contacts (HHCs) of smear positive pulmonary TB cases in South-India conducted 2010-2012, we assessed 1) the association between the Tuberculosis Contact Score (TCS) and the Infectivity Score, with established tools for Mycobacterium tuberculosis (Mtb) infection, corrected for established TB risk factors, and 2) the capability of the TB exposure scores to identify subclinical TB defined by Mtb-culture positivity in sputum or gastric aspirate (subjects < 5 years) specimen. RESULTS: Of 525 HHCs, 29 were Mtb-culture positive and 96.6% of these asymptomatic. The TCS and the Infectivity Score associated with positive Tuberculin Skin Test and QuantiFeron TB-Gold In-tube assay (QFT) results in multivariate analyses (TCS: ORTST 1.16, 95% CI: 1.01, 1.33; ORQFT 1.33 95% CI: 1.16, 1.51. Infectivity Score: ORTST 1.39, 95% CI: 1.10, 1.76; ORQFT 1.41 95% CI: 1.16, 1.71). The Infectivity Score showed a moderate capability to identify subclinical TB (AUC of 0.61, 95% CI: 0.52, 0.70). CONCLUSIONS: Although our results did not identify an easily applicable screening tool for subclinical TB, the present study indicates that focusing on TB-related symptoms in CI settings may be of limited value for early identification of HHCs with high risk for TB progression.

Effect of non-tuberculous Mycobacteria on host biomarkers potentially relevant for tuberculosis management.

BACKGROUND: Non-tuberculous mycobacteria (NTM) are different from Mycobacterium tuberculosis (MTB) both in their ubiquitous environmental distribution and in their reduced capacity to cause disease. While often neglected in favour of other infectious diseases, NTM may interfere with important aspects of TB control and management, namely the efficacy of new anti-tuberculosis (TB) vaccines; the immuno-diagnostic Tuberculin skin test (TST) and QuantiFERON TB Gold In Tube assay (QFTGIT); and immune biomarkers explored for their diagnostic and/or predictive potential. Our objective was therefore to explore host immune biomarkers in children who had NTM isolated from respiratory and/or gastric specimens. METHODOLOGY AND PRINCIPLE FINDINGS: The present study was nested within a prospective cohort study of BCG-vaccinated neonates in Southern India. In this setting, immune biomarkers from peripheral blood were analyzed in 210 children aged <3 years evaluated for TB using dual-colour-Reverse-Transcriptase-Multiple-Ligation-dependent-Probe-Amplification (dcRT-MLPA) and Bio-Plex assays. The children were classified based on clinical examination, chest X-rays and mycobacterial culture reports as either: 1) TB disease, 2) NTM present and 3) controls. The study shows a down-regulation of RAB33A (p<0.001) and up-regulation of TGFß1, IL-2 and IL-6 (all p<0.05) in children with TB disease, and that RAB33A, TGFBR2 and IL-10 (all p<0.05) were differentially expressed in children with NTM present when compared to children that were culture negative for MTB and NTM (controls). CONCLUSIONS AND SIGNIFICANCE: Carriage of NTM may reduce the specificity of future diagnostic and predictive immune biomarkers relevant to TB management.

The frequencies of IFNγ+IL2+TNFα+ PPD-specific CD4+CD45RO+ T-cells correlate with the magnitude of the QuantiFERON® gold in-tube response in a prospective study of healthy indian adolescents.

BACKGROUND: QuantiFERON-TB Gold In-Tube (QFT) is an IFNγ-release assay used in the diagnosis of Mycobacterium tuberculosis (MTB) infection. The risk of TB progression increases with the magnitude of the MTB-specific IFNγ-response. QFT reversion, also associated with low Tuberculin Skin Test responses, may therefore represent a transient immune response with control of M. tuberculosis infection. However, studies at the single cell level have suggested that the quality (polyfunctionality) of the T-cell response is more important than the quantity of cytokines produced. OBJECTIVE: To explore the quality and/or magnitude of mycobacteria-specific T-cell responses associated with QFT reversion and persistent QFT-positivity. METHODS: Multi-color flowcytometry on prospectively collected peripheral blood mononuclear cells was applied to assess mycobacteria-specific T-cell responses in 42 QFT positive Indian adolescents of whom 21 became QFT negative (reverters) within one year. Ten QFT consistent negatives were also included as controls. RESULTS: There was no difference in the qualitative PPD-specific CD4+ T-cell response between QFT consistent positives and reverters. However, compared with QFT consistent positives, reverters displayed lower absolute frequencies of polyfunctional (IFNγ+IL2+TNFα+) CD4+ T-cells at baseline, which were further reduced to the point where they were not different to QFT negative controls one year later. Moreover, absolute frequencies of these cells correlated well with the magnitude of the QFT-response. CONCLUSION: Whereas specific polyfunctional CD4+ T-cells have been suggested to protect against TB progression, our data do not support that higher relative or absolute frequencies of PPD-specific polyfunctional CD4+ T-cells in peripheral blood can explain the reduced risk of TB progression observed in QFT reverters. On the contrary, absolute frequencies of these cells correlated with the QFT-response, suggesting that this readout reflects antigenic load.

Associations between active travel to work and overweight, hypertension, and diabetes in India: a cross-sectional study.

BACKGROUND: Increasing active travel (walking, bicycling, and public transport) is promoted as a key strategy to increase physical activity and reduce the growing burden of noncommunicable diseases (NCDs) globally. Little is known about patterns of active travel or associated cardiovascular health benefits in low- and middle-income countries. This study examines mode and duration of travel to work in rural and urban India and associations between active travel and overweight, hypertension, and diabetes. METHODS AND FINDINGS: Cross-sectional study of 3,902 participants (1,366 rural, 2,536 urban) in the Indian Migration Study. Associations between mode and duration of active travel and cardiovascular risk factors were assessed using random-effect logistic regression models adjusting for age, sex, caste, standard of living, occupation, factory location, leisure time physical activity, daily fat intake, smoking status, and alcohol use. Rural dwellers were significantly more likely to bicycle (68.3% versus 15.9%; p<0.001) to work than urban dwellers. The prevalence of overweight or obesity was 50.0%, 37.6%, 24.2%, 24.9%; hypertension was 17.7%, 11.8%, 6.5%, 9.8%; and diabetes was 10.8%, 7.4%, 3.8%, 7.3% in participants who travelled to work by private transport, public transport, bicycling, and walking, respectively. In the adjusted analysis, those walking (adjusted risk ratio [ARR] 0.72; 95% CI 0.58-0.88) or bicycling to work (ARR 0.66; 95% CI 0.55-0.77) were significantly less likely to be overweight or obese than those travelling by private transport. Those bicycling to work were significantly less likely to have hypertension (ARR 0.51; 95% CI 0.36-0.71) or diabetes (ARR 0.65; 95% CI 0.44-0.95). There was evidence of a dose-response relationship between duration of bicycling to work and being overweight, having hypertension or diabetes. The main limitation of the study is the cross-sectional design, which limits causal inference for the associations found. CONCLUSIONS: Walking and bicycling to work was associated with reduced cardiovascular risk in the Indian population. Efforts to increase active travel in urban areas and halt declines in rural areas should be integral to strategies to maintain healthy weight and prevent NCDs in India. Please see later in the article for the Editors' Summary.

Evaluation of the Indian Migration Study Physical Activity Questionnaire (IMS-PAQ): a cross-sectional study.

BACKGROUND: Socio-cultural differences for country-specific activities are rarely addressed in physical activity questionnaires. We examined the reliability and validity of the Indian Migration Study Physical Activity Questionnaire (IMS-PAQ) in urban and rural groups in India. METHODS: A sub-sample of IMS participants (n = 479) was used to examine short term (≤ 1 month [n = 158]) and long term (> 1 month [n = 321]) IMS-PAQ reliability for levels of total, sedentary, light and moderate/vigorous activity (MVPA) intensity using intraclass correlation (ICC) and kappa coefficients (k). Criterion validity (n = 157) was examined by comparing the IMS-PAQ to a uniaxial accelerometer (ACC) worn ≥ 4 days, via Spearman's rank correlations (ρ) and k, using Bland-Altman plots to check for systematic bias. Construct validity (n = 7,000) was established using linear regression, comparing IMS-PAQ against theoretical constructs associated with physical activity (PA): BMI [kg/m2], percent body fat and pulse rate. RESULTS: IMS-PAQ reliability ranged from ICC 0.42-0.88 and k = 0.37-0.61 (≤ 1 month) and ICC 0.26 to 0.62; kappa 0.17 to 0.45 (> 1 month). Criterion validity was ρ = 0.18-0.48; k = 0.08-0.34. Light activity was underestimated and MVPA consistently and substantially overestimated for the IMS-PAQ vs. the accelerometer. Criterion validity was moderate for total activity and MVPA. Reliability and validity were comparable for urban and rural participants but lower in women than men. Increasing time spent in total activity or MVPA, and decreasing time in sedentary activity were associated with decreasing BMI, percent body fat and pulse rate, thereby demonstrating construct validity. CONCLUSION: IMS-PAQ reliability and validity is similar to comparable self-reported instruments. It is an appropriate tool for ranking PA of individuals in India. Some refinements may be required for sedentary populations and women in India.

Discovering mammography-based machine learning classifiers for breast cancer diagnosis.

This work explores the design of mammography-based machine learning classifiers (MLC) and proposes a new method to build MLC for breast cancer diagnosis. We massively evaluated MLC configurations to classify features vectors extracted from segmented regions (pathological lesion or normal tissue) on craniocaudal (CC) and/or mediolateral oblique (MLO) mammography image views, providing BI-RADS diagnosis. Previously, appropriate combinations of image processing and normalization techniques were applied to reduce image artifacts and increase mammograms details. The method can be used under different data acquisition circumstances and exploits computer clusters to select well performing MLC configurations. We evaluated 286 cases extracted from the repository owned by HSJ-FMUP, where specialized radiologists segmented regions on CC and/or MLO images (biopsies provided the golden standard). Around 20,000 MLC configurations were evaluated, obtaining classifiers achieving an area under the ROC curve of 0.996 when combining features vectors extracted from CC and MLO views of the same case.

Sociodemographic patterning of non-communicable disease risk factors in rural India: a cross sectional study.

OBJECTIVES: To investigate the sociodemographic patterning of non-communicable disease risk factors in rural India. DESIGN: Cross sectional study. SETTING: About 1600 villages from 18 states in India. Most were from four large states due to a convenience sampling strategy. PARTICIPANTS: 1983 (31% women) people aged 20-69 years (49% response rate). MAIN OUTCOME MEASURES: Prevalence of tobacco use, alcohol use, low fruit and vegetable intake, low physical activity, obesity, central adiposity, hypertension, dyslipidaemia, diabetes, and underweight. RESULTS: Prevalence of most risk factors increased with age. Tobacco and alcohol use, low intake of fruit and vegetables, and underweight were more common in lower socioeconomic positions; whereas obesity, dyslipidaemia, and diabetes (men only) and hypertension (women only) were more prevalent in higher socioeconomic positions. For example, 37% (95% CI 30% to 44%) of men smoked tobacco in the lowest socioeconomic group compared with 15% (12% to 17%) in the highest, while 35% (30% to 40%) of women in the highest socioeconomic group were obese compared with 13% (7% to 19%) in the lowest. The age standardised prevalence of some risk factors was: tobacco use (40% (37% to 42%) men, 4% (3% to 6%) women); low fruit and vegetable intake (69% (66% to 71%) men, 75% (71% to 78%) women); obesity (19% (17% to 21%) men, 28% (24% to 31%) women); dyslipidaemia (33% (31% to 36%) men, 35% (31% to 38%) women); hypertension (20% (18% to 22%) men, 22% (19% to 25%) women); diabetes (6% (5% to 7%) men, 5% (4% to 7%) women); and underweight (21% (19% to 23%) men, 18% (15% to 21%) women). Risk factors were generally more prevalent in south Indians compared with north Indians. For example, the prevalence of dyslipidaemia was 21% (17% to 33%) in north Indian men compared with 33% (29% to 38%) in south Indian men, while the prevalence of obesity was 13% (9% to 17%) in north Indian women compared with 24% (19% to 30%) in south Indian women. CONCLUSIONS: The prevalence of most risk factors was generally high across a range of sociodemographic groups in this sample of rural villagers in India; in particular, the prevalence of tobacco use in men and obesity in women was striking. However, given the limitations of the study (convenience sampling design and low response rate), cautious interpretation of the results is warranted. These data highlight the need for careful monitoring and control of non-communicable disease risk factors in rural areas of India.

Assessment of physical activity using accelerometry, an activity diary, the heart rate method and the Indian migration study questionnaire in south Indian adults.

OBJECTIVE: To validate questionnaire-based physical activity level (PAL) against accelerometry and a 24 h physical activity diary (24 h AD) as reference methods (Protocol 2), after validating these reference methods against the heart rate-oxygen consumption (HRVO2) method (Protocol 1). DESIGN: Cross-sectional study. SETTING: Two villages in Andhra Pradesh state and Bangalore city, South India. SUBJECTS: Ninety-four participants (fifty males, forty-four females) for Protocol 2; thirteen males for Protocol 1. RESULTS: In Protocol 2, mean PAL derived from the questionnaire (1.72 (sd 0.20)) was comparable to that from the 24 h AD (1.78 (sd 0.20)) but significantly higher than the mean PAL derived from accelerometry (1.36 (sd 0.20); P < 0.001). Mean bias of PAL from the questionnaire was larger against the accelerometer (0.36) than against the 24 h AD (-0.06), but with large limits of agreement against both. Correlations of PAL from the questionnaire with that of the accelerometer (r = 0.28; P = 0.01) and the 24 h AD (r = 0.30; P = 0.006) were modest. In Protocol 1, mean PAL from the 24 h AD (1.65 (sd 0.18)) was comparable, while that from the accelerometer (1.51 (sd 0.23)) was significantly lower (P < 0.001), than mean PAL obtained from the HRVO2 method (1.69 (sd 0.21)). CONCLUSIONS: The questionnaire showed acceptable validity with the reference methods in a group with a wide range of physical activity levels. The accelerometer underestimated PAL in comparison with the HRVO2 method.

Stress analysis of cantilever-fixed partial denture connector design using the finite element method / Análise de tensões de desenhos de conectores de pontes cantilever pelo método dos elementos finitos

Purpose: To analyze the stress distribution on a cantilever-fixed partial denture after simulation of maximum mastication loads in order to optimize its design. Methods: A cantilever-fixed partial denture framework was designed in the CAD-CAM system Everest®Kavo v2.0 using two materials, titanium and zirconium, with connectors of 5.28 mm² and 9.05 mm², respectively. A finite element model was built for stress analysis using simulations of mastication load. Results: For zirconia, only the molar cantilever with the smaller connector area and a 0.5-mm fillet exceeded the considered threshold resistance value of 575 MPa. All the other designs yielded resistances below this value. For titanium, only cantilevers with 9.05 mm² connector area and fillets of 1 or 1.4 mm presented stress values inferior to titanium yield strengh. Conclusion: Within the limitations of this study, it can be concluded that titanium cantilever-fixed partial denture frameworks with a 5.28 mm² connector area cannot support maximum mastication loads; frameworks of this material require larger connectors with fillets introduced in the gingival embrasure. Zirconia, however, supports maximum bite forces in most situations with both molar and premolar design cantilevers. Precaution should be taken when dealing with smaller connectors of 5.28 mm².

Objetivo: Analisar a distribuição de tensões em próteses parciais fixas em cantilever após aplicação de cargas simuladoras da mastigação, de forma a otimizar o seu desenho. Metodologia: Obteve-se a infra-estrutura de uma prótese parcial fixa em cantilever no sistema CAD-CAM Everest®Kavo v2.0, considerando dois materiais: titânio e zircônia, com conectores de 5,28 mm² e 9,05 mm², respectivamente. Gerou-se um modelo de elementos finitos, onde foram efetuadas análises de tensões com cargas simuladoras da mastigação. Resultados: Para zircônia, apenas o cantilever molar com área de conector mais reduzida, e concordância de 0,5 mm, excedeu o valor de resistência 575 MPa. Para o titânio, apenas o cantilever de 9,05 mm², com concordâncias de 1 e 1,4 mm, apresentou valores inferiores à tensão do titânio. Conclusão: Dentro das limitações deste estudo pode-se concluir que as infra-estruturas de titânio em cantilever não suportam cargas mastigatórias máximas com uma área de conector de 5,28 mm² e requerem conectores de áreas superiores, com concordâncias introduzidas na embrasura gengival. A zircônia geralmente suporta forças mastigatórias máximas com cantilever molar ou pré-molar. Deve-se ter precaução quando a área dos conectores é reduzida para 5,28 mm².

The Prospective Urban Rural Epidemiology (PURE) study: examining the impact of societal influences on chronic noncommunicable diseases in low-, middle-, and high-income countries.

BACKGROUND: Marked changes in the prevalence of noncommunicable diseases such as obesity, diabetes, and cardiovascular disease have occurred in developed and developing countries in recent decades. The overarching aim of the study is to examine the relationship of societal influences on human lifestyle behaviors, cardiovascular risk factors, and incidence of chronic noncommunicable diseases. METHODS: The Prospective Urban Rural Epidemiology (PURE) study is a large-scale epidemiological study that plans to recruit approximately 140,000 individuals residing in >600 communities in 17 low-, middle-, and high-income countries around the world. Individual data collection includes medical history, lifestyle behaviors (physical activity and dietary profile), blood collection and storage for biochemistry and future genetic analysis, electrocardiogram, and anthropometric measures. In addition, detailed information is being collected with respect to 4 environmental domains of interest-the built environment, nutrition and associated food policy, psychosocial/socioeconomic factors, and tobacco environment. A minimum follow-up of 10 years is currently planned. RESULTS: This report describes the design, justification, and methodology of the PURE study. The PURE study has been recruiting since 2002 and has enrolled 139,506 individuals by March 31, 2009. CONCLUSIONS: The PURE study builds on the work and experience gained through conduct of the INTERHEART study. Its design and extensive data collection are geared toward addressing major questions on causation and development of the underlying determinants of cardiovascular disease in populations at varying stages of epidemiologic transition.

The repeatability of self reported physical activity patterns in rural South India.

The objective of this study was to develop a physical activity assessment questionnaire for use in poorly educated and low socio-economic rural communities in developing countries and assess the repeatability of the measurements over a one-year duration. Physical Activity Level, as a composite measure of daily physical activity (PAL = estimated 24 hour energy expenditure / estimated basal metabolic rate) was derived from the semi-pictorial, interviewer based questionnaire assessing physical activity over the previous 1 week. PAL of both men and women was unchanged across the different seasons of the year. Correlations between the first physical activity questionnaire and the mean of at least 4 questionnaires administered during the course of one year were generally high (males: PAL 'r' = 0.69, individual domains 'r' between 0.57 and 0.82; females: PAL 'r' = 0.7, individual domains 'r' between 0.41 and 0.76, all p < 0.05). Within- individual % coefficient variations (CV) across 4 physical activity questionnaires were low for sleep duration and PAL (< 14%) but high for the other domains of physical activity (77-100%). The data, at least in this community, suggest that while within-individual variations in specific domains of physical activity may be considerable, the questionnaire that we designed can rank individuals in terms of their PAL or individual domains of physical activity fairly consistently. A single physical activity assessment using this instrument may therefore be adequate to rank individuals.

Finite element analysis of the mechanical behavior of a partially edentulous mandible as a function of cancellous bone density / Análise por elementos finitos do comportamento mecânico de uma mandíbula humana parcialmente edêntula em função da densidade óssea trabecular

Purpose: To present a methodological procedure to obtain the geometric and discrete models of a human mandible for numerical simulation of the biomechanical behavior of a partially edentulous mandible as a function of cancellous bone density. Methods: A 3D finite element method was used to assess the model of a partially edentulous mandible, Kennedy Class I, with dental implants placed at the region of teeth 33 and 43. The geometric solid model was built from CT-scan images and prototyping. In the discrete model a parametric analysis was performed to analyze the influence of cancellous bone density (25 %, 50 %, 75 %) on the development of mandibular stress and strain during simulation of masticatory forces in the anterior region. Results: Maximum von Mises stress and equivalent strain values in cancellous bone were found close to the loading area (masticatory forces). The peak stress and strain values occurred in the mandibular anterior region, and for the same masticatory force the equivalent stresses increased with bone density. Conclusion: The results suggest that the stresses and strains developed in the mandibular model were affected by cancellous bone density during the simulation of masticatory activity.

Objetivo: Apresentar uma metodologia para modelamento geométrico de uma mandíbula humana e obtenção de um modelo discreto para simular numericamente o comportamento biomecânico de uma mandíbula parcialmente edêntula em função de diferentes densidades do osso trabecular. Metodologia: Utilizou-se o método de elementos finitos 3D para realizar um estudo numérico sobre um modelo de mandíbula humana, desdentada parcial tipo Classe I de Kennedy, com implantes nas regiões dos dentes 33 e 43. O modelo sólido geométrico foi determinado por tomografia computorizada e prototipagem. No modelo discretizado foi realizada uma análise paramétrica para verificar a influência da densidade óssea do osso trabecular (25 %, 50 %, 75 %) no desenvolvimento de tensões e deformações da mandíbula durante a aplicação de forças mastigatórias na região anterior. Resultados: As tensões máximas de von Mises e deformações equivalentes no osso trabecular foram desenvolvidas próximo às regiões de aplicação das forças de mordida. Os picos de valores de tensões/deformações localizaram-se na região anterior da mandíbula, sendo que, para o mesmo valor de esforço de mordida, as tensões equivalentes aumentaram com a densidade óssea. Conclusão: Os resultados sugerem que as tensões e deformações desenvolvidas no modelo mandibular testado foram afetadas pelo grau de densidade do osso trabecular durante simulação de atividade mastigatória.

The relationship between maternal physical activity during pregnancy and birth weight.

INTRODUCTION: Earlier studies in India have demonstrated an inverse relationship between physical activity and birth weight in rural women who had high levels of physical activity related to agricultural and domestic activities. There are no data on urban Indian women from a wide range of socio-economic backgrounds with varying levels of physical activity. This study assessed the role of different domains of physical activity during pregnancy and its relation to birth weight. METHODS: Data on maternal anthropometry and maternal physical activity level were collected at the 1st trimester (baseline), the 2nd trimester and the 3rd trimester of pregnancy. Birth weight for 546 live born babies was measured immediately after delivery. RESULTS: The time spent in sedentary activities (median "cut-off" of 165 min/d) was significantly associated with maternal body weight in the first trimester of pregnancy (51.2 kg vs. 54.1 kg, p < 0.001). Women in the highest tertile of physical activity level in the 1st trimester were 1.58 times (95% CI: 1.02-2.44) more likely of having a baby in the lowest tertile of birth weight with reference to the first tertile. This significant association continued after adjustment for maternal weight and energy intake. CONCLUSION: The present study shows that physical activity in the first trimester is associated with low birth weight in Indian babies.

A study of stress and autonomic nervous function in first year undergraduate medical students.

Psychological stress is a risk factor for hypertension and coronary artery disease. The purpose of this study was to assess the impact of real life stressor, that of stress among first year medical students on cardiac autonomic regulation. Stress levels in 36 non-smoking, healthy first year medical students of either gender were assessed on a self-rating scale. Cardiac autonomic regulation was tested using both conventional tests and spectral analysis of heart rate variability (HRV). Nine subjects who obtained scores on the stress scale in the upper quartile were classified as the "stress" group and the rest constituted the "no stress" group (n = 27). There were no significant differences between the two groups on any of the conventional tests of autonomic nervous activity. The low frequency power in normalized units and low frequency high frequency ratio of heart rate variability in supine posture was significantly higher in the "stress" group compared to the "no stress" group. The low frequency power in normalized units was significantly positively correlated with total stress score. The changes were suggestive of a tilt in the resting cardiac autonomic balance towards increased sympathetic activity.

Use of rice bran oil in patients with hyperlipidaemia.

BACKGROUND: The quantity and type of dietary fat is known to affect plasma lipid concentration and hence the choice of cooking oil is important to lower the risk of coronary heart disease. Rice bran oil, which was not popular worldwide, is slowly being recognized as a 'healthy' oil in India. We assessed if rice bran oil had hypolipidaemic effects in subjects with elevated lipid levels. METHODS: The study had a cross-over design with subjects (n = 14) randomly assigned to consume either rice bran oil or refined sunflower oil in their homes, for a period of 3 months (period 1). After a washout period of 3 weeks, they were crossed over to the other oil (period 2). The serum lipid values were estimated at the beginning, on day 45 and day 90 of each phase. Additional parameters assessed included anthropometry, dietary and physical activity patterns. RESULTS: The use of rice bran oil significantly reduced plasma total cholesterol and triglyceride levels compared with sunflower oil. The reduction in plasma LDL-cholesterol with rice bran oil was just short of statistical significance (p = 0.06). HDL-cholesterol levels were unchanged. CONCLUSION: The use of rice bran oil as the main cooking oil significantly reduced serum cholesterol and triglyceride levels. The use of rice bran oil together with dietary and lifestyle modifications may have implications for reducing the risk of cardiovascular disease.