Tracheal instillation of urban PM2.5 suspension promotes acute cardiac polarization changes in rats

The mechanisms by which PM2.5 increases cardiovascular mortality are not fully identified. Autonomic alterations are the current main hypotheses. Our objective was to determine if PM2.5 induces acute cardiac polarization alterations in healthy Wistar rats. PM2.5 samples were collected on polycarbonate filters. Solutions containing 10, 20, and 50 µg PM2.5 were administered by tracheal instillation. P wave duration decreased significantly at 20 µg (0.99 ± 0.06, 0.95 ± 0.06, and 0.96 ± 0.07; P < 0.001), and 50 µg (0.98 ± 0.06, 0.98 ± 0.07, and 0.96 ± 0.08; 60, 90 and 120 min, respectively) compared to blank filter solution (P < 0.001). PR interval duration decreased significantly at 20 µg (0.99 ± 0.06, 0.98 ± 0.07, and 0.97 ± 0.08) and 50 µg (0.99 ± 0.05, 0.97 ± 0.0, and 0.95 ± 0.05; 60, 90, and 120 min, respectively) compared to blank filter and 10 µg (P < 0.001). QRS interval duration decreased at 20 and 50 µg in relation to blank filter solution and 10 µg (P < 0.001). QT interval duration decreased significantly (P < 0.001) with time in animals receiving 20 µg (0.94 ± 0.12, 0.88 ± 0.14, and 0.88 ± 0.11) and 50 µg (1.00 ± 0.13; 0.97 ± 0.11 and 0.98 ± 0.16; 60, 90 and 120 min, respectively) compared to blank filter solution and 10 µg (P < 0.001). PM2.5 induced reduced cardiac conduction time, within a short period, indicating that depolarization occurs more rapidly across ventricular tissue.

Detection of caliciviruses associated with acute infantile gastroenteritis in Salvador, an urban center in Northeast Brazil

Acute gastroenteritis caused by viruses is one of the leading causes of infantile morbidity. The aim of the present study was to investigate the presence of human caliciviruses of the genera norovirus and sapovirus in children up to 3 years of age with acute gastroenteritis from low-income communities in the city of Salvador, Brazil. This study is an extension of previous work carried out to establish the profile of the most prevalent enteric pathogens present in these communities. In this report, 139 fecal samples, collected from July 2001 to January 2002 were analyzed by RT-PCR and 13 (9%) were positive for human caliciviruses. By sequencing, seven isolates were characterized as norovirus genogroup GII and one as sapovirus genotype GII/1. Sequencing of the previously detected group-A rotaviruses and human astroviruses was also performed and revealed the circulation of rotavirus group A genotypes G1P[8] and G9P[8], and human astrovirus genotypes 6, 7, and 8. No mixed infection was observed. Community-based studies provide geographically representative information on disease burden. However, there are only a few reports in developing countries concerning the genotypes of the most important gastroenteric viruses detected in such communities. The present findings demonstrate the wide diversity of genotypes of the most important viruses responsible for acute gastroenteritis circulating in low-income communities.

Raising awareness of chronic kidney disease in a Brazilian urban population

The incidence and prevalence of chronic kidney disease have been increasing in recent years in developing countries. The aim of this study was to report the results of a general chronic kidney disease awareness program applied to an urban population in a large Brazilian city. From January 2002 to January 2005 a total of 8883 individuals in the city of Curitiba (PR, Brazil) were screened for hypertension, body mass index, hematuria, and proteinuria. A family history and previous medical diagnosis of hypertension and diabetes mellitus (DM) were also recorded. Of the 8883 individuals assessed, 56% were women, subject median age was 47 years (range: 17-93 years) and more than 90% were Caucasian. Thirty percent had signs of hematuria, 6% had proteinuria, and 3% had hematuria and proteinuria. The median of mean arterial pressure values was 93 mmHg (range: 71-135 mmHg) and 16% of the population screened had a history of hypertension. A significant positive family history of both hypertension or DM was present in 42% (P < 0.0001; chi-square = 83.18) and 7% (P < 0.0001; chi-square = 161.31) of the hypertensive group, respectively. Finally, the prevalence of hypertension and DM was significantly higher in older individuals with proteinuria. In the present study, a higher prevalence of hematuria and proteinuria was found in older individuals with hypertension and diabetes compared to the general population. These data confirm the need for public awareness of renal disease in high-risk individuals.

A time series analysis of meteorological factors and hospital outpatient admissions for cardiovascular disease in the Northern district of Guizhou Province, China

Findings on the effects of weather on health, especially the effects of ambient temperature on overall morbidity, remain inconsistent. We conducted a time series study to examine the acute effects of meteorological factors (mainly air temperature) on daily hospital outpatient admissions for cardiovascular disease (CVD) in Zunyi City, China, from January 1, 2007 to November 30, 2009. We used the generalized additive model with penalized splines to analyze hospital outpatient admissions, climatic parameters, and covariate data. Results show that, in Zunyi, air temperature was associated with hospital outpatient admission for CVD. When air temperature was less than 10°C, hospital outpatient admissions for CVD increased 1.07-fold with each increase of 1°C, and when air temperature was more than 10°C, an increase in air temperature by 1°C was associated with a 0.99-fold decrease in hospital outpatient admissions for CVD over the previous year. Our analyses provided statistically significant evidence that in China meteorological factors have adverse effects on the health of the general population. Further research with consistent methodology is needed to clarify the magnitude of these effects and to show which populations and individuals are vulnerable.

ATIVIDADE ENZIMÁTICA DE MICRORGANISMOS ISOLADOS DO JACATUPÉ (Pachyrhizus erosus L. Urban)

O isolamento e a identificação de microrganismos produtores de enzimas de interesse comercial, utilizando tubérculos de jacatupé (Pachyrhizus erosus L. Urban), foi o objetivo principal deste trabalho. Isolaram-se microrganismos endofíticos e epifíticos identificados por observação micromorfológica. A avaliação da atividade enzimática das linhagens foi determinada pelo método de difusão em ágar. As sessenta e oito linhagens isoladas dos tubérculos de jacatupé foram cultivadas em meio sólido específico para amilase, lipase, protease e celulase por 96h a 280 C. Os microrganismos epifíticos encontrados foram Pithomyces (7,3%), Aspergillus (19,2%), Fusarium (5,9%) e Trichoderma (5,8%), e os endofíticos foram Mucor (7,3%), Rhizopus (10,3%), Bacillus (19,0%), Staphylococcus (10,3%) e Nocardiopsis (15%). As linhagens de Nocardiopsis sp. apresentaram atividade lipolítica superior à do padrão, porém a atividade amilolítica não apresentou diferença significativa comparada com o padrão. As linhagens de Mucor sp., Pithomyces sp. e Staphylococcus sp. produziram atividade proteolítica abaixo do padrão. Nenhum isolado apresentou atividade celulolítica.

Germinação de sementes de Operculina macrocarpa (L.) Farwel e Operculina alata (Ham.) Urban

Várias espécies vegetais nativas produzem sementes que, mesmo vivas, apresentam dificuldades para germinar. Assim, foram conduzidos dois experimentos com o objetivo de identificar métodos para a superação da dormência de sementes de Operculina macrocarpa e para a germinação de sementes de O. macrocarpa e Operculina alata. No primeiro, sementes de O. macrocarpa foram submetidas a oito tratamentos visando a superação de dormência: frio seco, calor úmido, imersão em água oxigenada, água quente e em ácido sulfúrico, frio úmido, escarificação mecânica, embebição em nitrato de potássio, além da testemunha, determinando-se os percentuais de germinação, de sementes duras e de mortas. No segundo ensaio, sementes de O. macrocarpa e O. alata, após escarificadas, foram semeadas em substratos de areia e de papel e colocadas para germinar sob cinco combinações de luz e temperatura: luz contínua a 25ºC constante; luz contínua com temperaturas alternadas (20ºC/16h-35ºC/8h); escuro contínuo a 25ºC constante; escuro contínuo com temperaturas alternadas (20ºC/16h-35ºC/8h) e alternância de luz e temperaturas (luz/35ºC/8h-escuro/20ºC/16h). Determinaram-se o percentual e o índice de velocidade de germinação. Concluiu-se que Operculina macrocarpa apresenta sementes dormentes, destacando-se a escarificação mecânica como o método mais eficiente para a sua superação; o substrato papel, associado à temperatura de 20-35ºC e em ausência de luz, é o mais indicado para a germinação de sementes de Operculina macrocarpa e Operculina alata.