The approximate entropy of the electromyographic signals of tremor correlates with the osmotic fragility of human erythrocytes

<p>Abstract</p> <p>Background</p> <p>The main problem of tremor is the damage caused to the quality of the life of patients, especially those at more advanced ages. There is not a consensus yet about the origins of this disorder, but it can be examined in the correlations between the biological signs of aging and the tremor characteristics.</p> <p>Methods</p> <p>This work sought correlations between the osmotic fragility of erythrocytes and features extracted from electromyographic (EMG) activity resulting from physiological tremor in healthy patients (N = 44) at different ages (24-87 years). The osmotic fragility was spectrophotometrically evaluated by the dependence of hemolysis, provided by the absorbance in 540 nm (<it>A</it>_<it>54</it><it>o)</it>, on the concentration of NaCl. The data were adjusted to curves of sigmoidal regression and characterized by the half transition point (<it>H</it>_<it>50</it>), amplitude of lysis transition (<it>dx</it>) and values of <it>A</it>_{<it>540 </it>}in the curve regions that characterize the presence of lysed (<it>A</it>_<it>1</it>) and preserved erythrocytes (<it>A</it>_<it>2</it>). The approximate entropy was estimated from EMG signals detected from the extensor carpi ulnaris muscle during the movement of the hand of subjects holding up a laser pen towards an Archimedes spiral, fixed in a whiteboard. The evaluations were carried out with the laser pen at rest, at the center of the spiral, and in movement from the center to the outside and from outside to the center. The correlations among the parameters of osmotic fragility, tremor and age were tested.</p> <p>Results</p> <p>Negative correlations with age were found for <it>A</it>_{<it>1 </it>}and <it>dx</it>. With the hand at rest, a positive correlation with <it>H</it>_{<it>50 </it>}was found for the approximate entropy. Negative correlations with <it>H</it>_{<it>50 </it>}were found for the entropy with the hand in movement, as from the center to the outside or from the outside to the center of the spiral.</p> <p>Conclusion</p> <p>In healthy individuals, the increase in the erythrocyte osmotic fragility was associated with a decrease in the approximate entropy for rest tremor and with an increase of the entropy for movement tremor. This suggests that the neuromuscular degeneration associated with tremor entails also the mechanisms involved in the breakdown of structural homeostasis of the erythrocyte membrane.</p

Elemental hydrochemistry assessment on its variation and quality status in Langat River, Western Peninsular Malaysia.

This paper discusses the hydrochemistry variation and its quality status in Langat River, based on the chemistry of major ions, metal concentrations and suitability for drinking purposes. Water samples were collected from 30 different stations to assess their hydrochemical characteristics. The physico-chemical parameters selected were temperature, electrical conductivity, total dissolved solids (TDS), salinity, dissolved oxygen , pH, redox potential, HCO3, Cl, SO4, NO3, Ca, Na, K, Mg, 27Al, 138Ba, 9Be, 111Cd, 59Co, 63Cu, 52Cr, 57Fe, 55Mn, 60Ni, 208Pb, 80Se and 66Zn to investigate the variation of the constituents in the river water. Most of the parameters comply with the Drinking Water Quality Standard of the World Health Organization and the Malaysian National Standard for Drinking Water Quality by the Malaysia Ministry of Health except for EC, TDS, Cl, HCO3, SO4, Na, Mg, Al, Fe and Se. The results show that the Langat River is unsuitable for drinking purposes directly without treatment

Social support and common mental disorder among medical students

INTRODUÇÃO:Diferentes formas de sofrimento psíquico têm sido identificadas em estudantes da área da saúde, em especial no curso de Medicina.OBJETIVO:Estimar a prevalência de sofrimento psíquico entre estudantes de Medicina em uma faculdade no Sudeste do Brasil e avaliar sua associação com apoio social.MÉTODO:Trata-se de um estudo transversal. Foram aplicados questionários para alunos do 1º ao 6º ano do curso de Medicina da Universidade Estadual Paulista Júlio de Mesquita Filho, investigando-se características demográficas relacionadas ao curso e à adaptação à cidade. Sofrimento psíquico foi investigado na forma de Transtorno Mental Comum (TMC), avaliado por meio do Self-Reporting Questionnaire (SRQ-20). Apoio social foi avaliado com a Escala de Apoio Social (EAS). As associações entre o desfecho e as variáveis explanatórias foram analisadas por meio do teste do χ2 e, na análise multivariada, por meio da Regressão Logística, com p < 0,05.RESULTADOS:A taxa de resposta foi de 80,7%, não havendo diferença estatística entre a mostra e a população-alvo no que diz respeito ao gênero (p = 0,78). A média de idade foi de 22 anos (desvio padrão - DP = 2,2) com predomínio de mulheres (58,2%) e estudantes que vivem com amigos (62%). A prevalência de TMC foi de 44,9% (IC95% 40,2 - 49,6). Após a análise multivariada, mantiveram-se associados a TMC: sentir-se rejeitado no último ano (p < 0,001), ter pensado ou pensar em abandonar o curso (p < 0,001) e interação, avaliada pela EAS (p = 0,002).CONCLUSÕES:A prevalência de TMC entre estudantes de Medicina mostrou-se elevada, identificando-se o apoio social insuficiente como fator de risco. Esses achados sugerem que intervenções voltadas para propiciar melhores condições de interação social entre estudantes poderiam ser benéficas, diminuindo a prevalência de TMC nesse grupo.INTRODUCTION:Different kinds of psychological distress have been identified for students in the health field, especially in the medical school.OBJECTIVE:To estimate the prevalence of mental suffering among medical students in the Southeastern Brazil and asses its association with social support.METHODS:It is a cross-sectional study. Structured questionnaires were applied for students from the 1st up to the 6th years of the medical school of Universidade Estadual Paulista Júlio de Mesquita Filho, assessing demographic variables related to aspects of graduation and adaptation to the city. Psychological suffering was defined as a common mental disorder (CMD) assessed by the Self Reporting Questionnaire (SRQ-20). Social support was assessed by the social support scale of the Medical Outcomes Study (MOS). The association between the outcome and explanatory variables was assessed by the χ2 test and Logistic Regression, for the multivariate analyses, using p < 0.05.RESULTS:The response rate was of 80.7%, with no differences between sample and the population regarding gender (p = 0.78). The average age was 22 years old (standard deviation - SD = 2.2), mainly women (58.2%) and students who were living with friends (62%). The prevalence of CMD was 44.9% (95%CI 40.2 - 49.6). After the multivariate analyses, the explanatory variables that were associated with CMD were: feeling rejected in the past year (p < 0.001), thinking about leaving medical school (p < 0.001) and interaction in the MOS scale (p = 0.002).CONCLUSIONS:The prevalence of CMD among medical students was high and insufficient social support was an important risk factor. Our findings suggest that interventions to improve social interaction among those students could be beneficial, decreasing the prevalence of CMD in this group.Hospital das Clínicas de Ribeirão PretoUniversidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Medicina de Botucatu Departamento de Neurologia, Psicologia e PsiquiatriaUniversidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Medicina de Botucatu Departamento de Neurologia, Psicologia e Psiquiatri

EBV renders B cells susceptible to HIV-1 in humanized mice

HIV and EBV are human pathogens that cause a considerable burden to worldwide health. In combination, these viruses are linked to AIDS-associated lymphomas. We found that EBV, which transforms B cells, renders them susceptible to HIV-1 infection in a CXCR4 and CD4-dependent manner in vitro and that CXCR4-tropic HIV-1 integrates into the genome of these B cells with the same molecular profile as in autologous CD4+ T cells. In addition, we established a humanized mouse model to investigate the in vivo interactions of EBV and HIV-1 upon coinfection. The respective mice that reconstitute human immune system components upon transplantation with CD34+ human hematopoietic progenitor cells could recapitulate aspects of EBV and HIV immunobiology observed in dual-infected patients. Upon coinfection of humanized mice, EBV/HIV dual-infected B cells could be detected, but were susceptible to CD8+ T-cell–mediated immune control.</jats:p

Produtividade e teor de sólidos solúveis de frutos de cultivares de morangueiro em ambiente protegido Yield and soluble solids contents of fruits of strawberry cultivars in protected cultivation

O cultivo protegido é uma alternativa para controlar variações climáticas em diferentes locais e épocas de plantio, entretanto, seus efeitos e interações com a cultura do morangueiro ainda são pouco conhecidos. O objetivo desse trabalho foi avaliar a influência de três sistemas de cultivo (túnel alto, túnel baixo e a campo) na produtividade, massa média de frutos e no teor de sólidos solúveis dos frutos das cultivares de morango Dover, Camarosa, Sweet Charlie e Oso Grande em Guarapuava-PR. Quanto à produtividade e massa média de frutos, a cultivar Camarosa foi a melhor nos cultivos em túnel, tanto alto quanto baixo, pelo seu excelente desempenho. Os frutos da cultivar Sweet Charlie apresentaram o maior teor de sólidos solúveis nos três ambientes de cultivo. A produtividade e a massa média dos frutos foram significativamente superiores nos cultivos em túneis, alto e baixo, quando comparados ao cultivo a campo. O ambiente que propiciou maior acúmulo de sólidos solúveis nos frutos foi o túnel alto, diferindo significativamente dos demais ambientes de cultivo.<br>Protected cultivation is an alternative to control the climatic effects in different places and times of planting, however, its effects and interactions with the strawberry crop are little known. The goal of this study was to evaluate the effects of three cropping systems (high tunnel, low tunnel and field) on yield, mean fruit mass and the soluble solids contents of strawberry cultivars Dover, Camarosa, Sweet Charlie and Oso Grande in Guarapuava. Camarosa cultivar presents an excellent performance regarding yield and mean fruit mass in high and low tunnel cultivation; hence, these cropping system can be indicated. Fruits of Sweet Charlie cultivar had the highest content of soluble solids in all the cultivation environments. Yield and mean fruit mass obtained from high and low tunnels were significantly higher than in the field. The environment high tunnel allowed greater accumulation of soluble solids, differing significantly from other evaluated environments