Changes in cell shape and desmin intermediate filament distribution are associated with down-regulation of desmin expression in C2C12 myoblasts grown in the absence of extracellular Ca2+

Desmin is the main intermediate filament (IF) protein of muscle cells. In skeletal muscle, desmin IFs form a scaffold that interconnects the entire contractile apparatus with the subsarcolemmal cytoskeleton and cytoplasmic organelles. The interaction between desmin and the sarcolemma is mediated by a number of membrane proteins, many of which are Ca2+-sensitive. In the present study, we analyzed the effects of the Ca2+ chelator EGTA (1.75 mM) on the expression and distribution of desmin in C2C12 myoblasts grown in culture. We used indirect immunofluorescence microscopy and reverse transcription polymerase chain reaction (RT-PCR) to analyze desmin distribution and expression in C2C12 cells grown in the presence or absence of EGTA. Control C2C12 myoblasts showed a well-spread morphology after a few hours in culture and became bipolar when grown for 24 h in the presence of EGTA. Control C2C12 cells showed a dense network of desmin from the perinuclear region to the cell periphery, whereas EGTA-treated cells showed desmin aggregates in the cytoplasm. RT-PCR analysis revealed a down-regulation of desmin expression in EGTA-treated C2C12 cells compared to untreated cells. The present results suggest that extracellular Ca2+ availability plays a role in the regulation of desmin expression and in the spatial distribution of desmin IFs in myoblasts, and is involved in the generation and maintenance of myoblast cell shape.

Distribution of microglial cells in the cerebral hemispheres of embryonic and neonatal chicks

The distribution, morphology and morphometry of microglial cells in the chick cerebral hemispheres from embryonic day 4 (E4) to the first neonatal day (P1) were studied by histochemical labeling with a tomato (Lycopersicon esculentum) lectin. The histochemical analysis revealed lectin-reactive cells in the nervous parenchyma on day E4. Between E4 (5.7 ± 1.35 mm length) and E17 (8.25 ± 1.2 mm length), the lectin-reactive cells were identified as ameboid microglia and observed starting from the subventricular layer, distributed throughout the mantle layer and in the proximity of the blood vessels. After day E13, the lectin-reactive cells exhibited elongated forms with small branched processes, and were considered primitive ramified microglia. Later, between E18 (5.85 ± 1.5 mm cell body length) and P1 (3.25 ± 0.6 mm cell body length), cells with more elongated branched processes were observed, constituting the ramified microglia. Our findings provide additional information on the migration and differentiation of microglial cells, whose ramified form is observed at the end of embryonic development. The present paper focused on the arrangement of microglial cells in developing cerebral hemispheres of embryonic and neonatal chicks, which are little studied in the literature. Details of morphology, morphometry and spatial distribution of microglial cells contributed to the understanding of bird and mammal central nervous system ontogeny. Furthermore, the identification and localization of microglial cells during the normal development could be used as a morphological guide for embryonic brain injury researches.

Spatial variability of soil fertility and its relationship with seed physiological potential in a soybean production area

The correlation of soil fertility x seed physiological potential is very important in the area of seed technology but results published with that theme are contradictory. For this reason, this study to evaluate the correlations between soil chemical properties and physiological potential of soybean seeds. On georeferenced points, both soil and seeds were sampled for analysis of soil fertility and seed physiological potential. Data were assessed by the following analyses: descriptive statistics; Pearson's linear correlation; and geostatistics. The adjusted parameters of the semivariograms were used to produce maps of spatial distribution for each variable. Organic matter content, Mn and Cu showed significant effects on seed germination. Most variables studied presented moderate to high spatial dependence. Germination and accelerated aging of seeds, and P, Ca, Mg, Mn, Cu and Zn showed a better fit to spherical semivariogram: organic matter, pH and K had a better fit to Gaussian model; and V% and Fe showed a better fit to the linear model. The values for range of spatial dependence varied from 89.9 m for P until 651.4 m for Fe. These values should be considered when new samples are collected for assessing soil fertility in this production area.

Morphological and phytochemical characterization of Piper hispidinervum DC. and Piper aduncum L. populations in the state of Acre

Because of the increasing demand of the industry for the production of essential oils, studies highlight the genetic variability of Piper hispidinervum and P. aduncum species according to their patterns of spatial distribution, showing the Amazon region as the source of superior genetic material in the production of safrole and dillapiole. Thus, the objective this study was to characterize the morphology and the phytochemistry of Piper hispidinervum and P. aduncum populations in the Active Germplasm Bank of Embrapa Acre to generate subsidies for the genetic improvement of these species. The results showed that the average values for leaf width and length were 141.67 and 48.04 mm, and petioles length and diameter measurements were 2.83 and 1.78 mm for P. hispidinervum and 189.22; 67.74; 6.03 and 2.22 mm for P. aduncum respectively. The average height and canopy volume measurements were 2.39 m and 6.30 m3 and 2.70 m and 7.78 m3 respectively for each species. For P. hispidinervum, the population with higher performance indried yield and content of safrole was population 02, with 3.9%, and the population 04 showed 94.3% safrole content, both with genetic material from the region of Acrelândia and Plácido de Castro. To P. aduncum, the populations with better performance were 207, 208 and 209, forming a homogeneous group with dried yield average of 3.8% and dillapiol content of 84-85%. Such populations are indicated for selection in breeding program of these species due to better performance.

Aedes albopictus in an area of Misiones, Argentina

Until early 1998 the presence of Aedes albopictus had never been detected in Argentina. During April of the same year, few individuals of this species were recorded in 33 breeding sites found in 25 out of 161 inspected houses in the city of Eldorado, Province of Misiones. The homogeneous spatial distribution of the proliferation foci suggests the existence of a generalized infestation in this locality during the study period.

Drug abuse among workers in Brazilian regions

OBJECTIVE: Many business organizations in Brazil have adopted drug testing programs in the workplace since 1992. Rehabilitation, rather than layoff and disciplinary measures, has been offered as part of the Brazilian employee assistance programs. The purpose study is to profile drug abuse among company workers of different Brazilian geographical regions. METHODS: Urine samples of 12,700 workers from five geographical regions were tested for the most common illicit drugs of abuse in the country: marijuana, cocaine, and amphetamine. Enzyme multiplied immunoassay technique (EMIT) and gas chromatography coupled with mass spectrometry (GC/MS) were the techniques utilized for urine testing. The distribution of collected urine samples according to geographical regions was: 72.0% southeast, 13.8% northeast, 7.9% south, 5.7% central west and 0.6% north. RESULTS: Of all samples analyzed, 1.8% was found to be positive for drugs: 0.5% from the south region, 1.1% from northeast, 1.2% from central west, 1.3% from north, and 2.2% from southeast. Of these, 59.9% was marijuana, 17.7% cocaine, 14.6% amphetamine, and 7.7% associated drugs. CONCLUSIONS: The distribution of drugs found in the samples shows a regional variation. Marijuana, however, was found in all regions. Cocaine was seen only in central west and southeast regions. Amphetamine was found in northeast, central west, and southeast regions.

Aedes aegypti entomological indices in an endemic area for dengue in Sao Paulo State, Brazil

OBJECTIVE: To evaluate the most productive types of properties and containers for Aedes aegypti and the spatial distribution of entomological indices.METHODS: Between December 2006 and February 2007, the vector's immature forms were collected to obtain entomological indices in 9,875 properties in the Jaguare neighborhood of Sao Jose do Rio Preto, SP, Southeastern Brazil. In March and April 2007, a questionnaire about the conditions and characteristics of properties was administered. Logistic regression was used to identify variables associated with the presence of pupae at the properties. Indices calculated per block were combined with a geo-referenced map, and thematic maps of these indices were obtained using statistical interpolation.RESULTS: The properties inspected had the following Ae. aegypti indices: Breteau Index = 18.9, 3.7 larvae and 0.42 pupae per property, 5.2 containers harboring Ae. aegypti per hectare, 100.0 larvae and 11.6 pupae per hectare, and 1.3 larvae and 0.15 pupae per inhabitant. The presence of yards, gardens and animals was associated with the presence of pupae.CONCLUSIONS: Specific types of properties and containers that simultaneously had low frequencies among those positive for the vector and high participation in the productivity of larvae and pupae were not identified. The use of indices including larval and pupal counts does not provide further information beyond that obtained from the traditional Stegomyia indices in locations with characteristics similar to those of São José do Rio Preto. The indices calculated per area were found to be more accurate for the spatial assessment of infestation. The Ae. aegypti infestation levels exhibited extensive spatial variation, indicating that the assessment of infestation in micro areas is needed.

Inequalities in health: living conditions and infant mortality in Northeastern Brazil

OBJECTIVE To analyze the variation of infant mortality as per condition of life in the urban setting.METHODS Ecological study performed with data regarding registered deaths of children under the age of one who resided in Aracaju, SE, Northeastern Brazil, from 2001 to 2010. Infant mortality inequalities were assessed based on the spatial distribution of the Living Conditions Index for each neighborhood, classified into four strata. The average mortality rates of 2001-2005 and 2006-2010 were compared using the Student’s t-test.RESULTS Average infant mortality rates decreased from 25.3 during 2001-2005 to 17.7 deaths per 1,000 live births in 2006-2010. Despite the decrease in the rates in all the strata during that decade, inequality of infant mortality risks increased in neighborhoods with worse living conditions compared with that in areas with better living conditions.CONCLUSIONS Infant mortality rates in Aracaju showed a decline, but with important differences among neighborhoods. The assessment based on a living condition perspective can explain the differences in the risks of infant mortality rates in urban areas, highlighting health inequalities in infant mortality as a multidimensional issue.

Phlebotominae sand flies associated with a tegumentary leishmaniasis outbreak, Tucumán Province, Argentina

The distribution of sand flies and cases of tegumentary leishmaniasis in the area surrounding JB Alberd city, and the proximities of Catamarca province were studied, after an increase of reported cases from JB Alberdi, Tucumán province, in 2003. Of 14 confirmed cases, 57% were females and 57% were less than 15 years old, suggesting peridomestic transmission. However, 86% of them lived close to the Marapa river forest gallery and related wooded areas. Over 1,013 sand flies were collected; Lutzomyia neivai (Pinto, 1926) was prevalent at all the sites (92.3%), while Lutzomyia migonei (França, 1920) (6.7%) and Lu. cortelezzii (Brèthes, 1923) (1%) were also found. The spatial distribution of Lu. neivai overlapped that of the cases, with higher abundance in microfocal hot spots close to the river in stable vegetated habitats or modified habitats with shadow and animal blood sources. The cumulative outcome of anthropic, ecological and climatic factors could have contributed to the onset of the outbreak.

Malacological survey of Biomphalaria snails in municipalities along the Estrada Real in the southeast of the State of Minas Gerais, Brazil

INTRODUCTION: The increasing practice of ecotourism and rural tourism in the State of Minas Gerais, Brazil, highlights the importance of studies concerning the occurrence of potential intermediate hosts of Schistosoma mansoni. This study aimed to identify species of Biomphalaria snails in municipalities along the Estrada Real, an important Brazilian tourism project. METHODS: The specimens were collected in different water collections of 36 municipalities along the Estrada Real in the southeast of the State of Minas Gerais. Biomphalaria species were characterized using both morphological and molecular approaches. The research was conducted between August 2005 and September 2009 and all the sites visited were georeferenced using GPS. RESULTS: Six Biomphalaria species were found in 30 of the 36 municipalities studied: glabrata, tenagophila, straminea, peregrina, occidentalis and schrammi. The first three species of Biomphalaria, recognized as intermediate hosts of S. mansoni, were present in 33.3%, 47.2% and 8.3% of the municipalities studied, respectively. The mollusks were found in different types of water collections and no infection by S. mansoni was detected. The highest occurrence of Biomphalaria concentration was verified in the area covered by the Caminho Novo route (Diamantina/MG to Rio de Janeiro/RJ). CONCLUSIONS: Considering the occurrence of schistosomiasis in the State of Minas Gerais and the socioeconomic repercussions involved in the Estrada Real Project, this work focuses on the vulnerability of water collections due to the presence of Biomphalaria mollusks and emphasizes the need for epidemiological surveillance and sanitary and educational measures integrated with the local community and tourism sectors.

Epidemiological aspects of human and canine visceral leishmaniasis in Montes Claros, State of Minas Gerais, Brazil, between 2007 and 2009

INTRODUCTION: Visceral leishmaniasis (VL) is an expanding zoonosis in Brazil and is becoming urbanized in several Brazilian regions. This study aims to describe the epidemiological features of human and canine VL in the municipality of Montes Claros, State of Minas Gerais, by focusing on their spatial distribution. METHODS: Data concerning human cases and reactive dogs for VL from 2007 to 2009 were obtained from the Information System for Disease Notification (SINAN) and from reports of the local Centro de Controle de Zoonoses (CCZ), respectively. The addresses of human and canine cases have been georeferenced and localized in thematic maps, allowing their spatial visualization as well as the identification of areas at risk of VL transmission. RESULTS: Ninety-five cases of human VL were reported in the period. The 0-9-year-old age group (48.4%) was the most affected, within which the majority consisted of male patients (64%). Of the samples collected for the canine serological survey, 2,919 (6.3%) were reactive to VL. The spatial localization of these cases shows that the disease was scattered in the urban area of the municipality. Areas showing a higher dissemination risk were concentrated in the central, northwestern, and southern regions of the city. CONCLUSIONS: Identifying the areas most at risk in urban Montes Claros may help guide actions toward local epidemiological vigilance and control.

Geographic analysis on the occurrence of human and canine leptospirosis in the city of Maringá, state of Paraná, Brazil

INTRODUCTION: Leptospirosis is a zoonotic disease, the primary hosts of which are wild, synanthropic, and household animals. Humans behave as terminal and accidental hosts. The prevalence of leptospirosis depends on carrier animals that disseminate the agent, on the environmental survival of this agent, and on the contact of susceptible individuals. Each serovar has one or more hosts with different adaptation levels. The focuses of leptospirosis are infected, sick, and asymptomatic animals, which are considered to be sources of environmental infection. This study aimed to determine the risk areas for leptospiral infection in stray dogs and patients diagnosed with leptospirosis from 2006 to 2008 in Maringá, State of Paraná, Brazil. METHODS: Three hundred and thirty-five stray dogs and 25 patients were studied. Serum from both animals and patients was examined by the microscopic serum agglutination test to study anti-leptospiral antibodies. To determine the risk areas and the spatial distribution of the disease, thematic maps were designed. RESULTS: Forty-one (12.2%) dogs positive for one or more leptospire serovars were observed, the most frequent serovars being Pyrogenes (43.9%), Canícola (21.9%), and Copennhageni (19.5%). Among the humans, 2 (8%) were positive for serovars Pyrogenes and Hardjo Prajitno and for Pyrogenes and Cynopteri. CONCLUSIONS: Spatial analysis showed that the risk for dogs and humans in the City of Maringá to become infected with leptospires exists in both the central and the peripheral areas, a fact that reinforces the relevance of this study and of continuous epidemiological and environmental surveillance actions to control the disease in animals and in humans.

Bacterial meningitis and living conditions

INTRODUCTION: Bacterial meningitis has great social relevance due to its ability to produce sequelae and cause death. It is most frequently found in developing countries, especially among children. Meningococcal meningitis occurs at a high frequency in populations with poor living conditions. This study describes the temporal evolution of bacterial meningitis in Salvador, Brazil, 1995-2009, and verifies the association between its spatial variation and the living conditions of the population. METHODS: This was an ecological study in which the areas of information were classified by an index of living conditions. It examined fluctuations using a trend curve, and the relationship between this index and the spatial distribution of meningitis was verified using simple linear regression. RESULTS: From 1995-2009, there were 3,456 confirmed cases of bacterial meningitis in Salvador. We observed a downward trend during this period, with a yearly incidence of 9.1 cases/100,000 population and fatality of 16.7%. Children aged <5 years old and male were more affected. There was no significant spatial autocorrelation or pattern in the spatial distribution of the disease. The areas with the worst living conditions had higher fatality from meningococcal disease (β = 0.0078117, p < 0.005). CONCLUSIONS: Bacterial meningitis reaches all social strata; however, areas with poor living conditions have a greater proportion of cases that progress to death. This finding reflects the difficulties for ready access and poor quality of medical care faced by these populations.

Genetic diversity in rosewood saplings (Aniba rosaeodora ducke, Lauraceae): an ecological approach

This article takes an ecological approach to the genetic diversity of Rosewood (Aniba rosaeodora Ducke) in a central Amazonian terra firme forest north of Manaus. Planted Rosewood setting, under partial shaded canopy, were assessed in terms of fruiting production, frugivory, and seed dispersal. Using RAPD molecular analysis procedures, the influence of the spatial distribution of adult trees on the genetic diversity (polymorphism) of saplings was assessed with genetic samples from 34 reproductive trees and 60 saplings. The density and distribution patterns the reproductive trees did not modify the sapling"s diversity (1.86%, AMOVA). Two types of adult tree dispersion were identified; i) clumped and ii) more widely dispersed. Polymorphism (77.5%) and gene flow were high between these. Although more sapling genetic variability in areas with a higher density of mature plants was not as high as expected, density did not affect the genetic diversity of samplings, indicating a high incidence of gene flow amongst trees. In planted Rosewood population (surrounded by low disturbed forest), fruiting trees experienced a high level of removal of seeds by toucans (Rhamphastidae), about of 50%. The high gene flow found among native trees suggested that toucans, promoting seed rain at short and long distances from maternal trees, actively contribute to the maintenance of genetic diversity within wild rosewood populations.

Soil CO2 efflux in central Amazonia: environmental and methodological effects

Soil respiration plays a significant role in the carbon cycle of Amazonian rainforests. Measurements of soil respiration have only been carried out in few places in the Amazon. This study investigated the effects of the method of ring insertion in the soil as well as of rainfall and spatial distribution on CO2 emission in the central Amazon region. The ring insertion effect increased the soil emission about 13-20% for sandy and loamy soils during the firsts 4-7 hours, respectively. After rainfall events below 2 mm, the soil respiration did not change, but for rainfall greater than 3 mm, after 2 hours there was a decrease in soil temperature and respiration of about 10-34% for the loamy and sand soils, with emissions returning to normal after around 15-18 hours. The size of the measurement areas and the spatial distribution of soil respiration were better estimated using the Shuttle Radar Topographic Mission (SRTM) data. The Campina reserve is a mosaic of bare soil, stunted heath forest-SHF and tall heath forest-THF. The estimated total average CO2 emissions from the area was 3.08±0.8 µmol CO2 m-2 s-1. The Cuieiras reserve is another mosaic of plateau, slope, Campinarana and riparian forests and the total average emission from the area was 3.82±0.76 µmol CO2 m-2 s-1. We also found that the main control factor of the soil respiration was soil temperature, with 90% explained by regression analysis. Automated soil respiration datasets are a good tool to improve the technique and increase the reliability of measurements to allow a better understanding of all possible factors driven by soil respiration processes.