83 resultados para region-based algorithms


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17 of 20 adult sera from the Amapa region of Brazil were active in the inhibition of P. falciparum sporozoite invasion (ISI) assay which has been correlated with protective antibodies. In contrast 11 sera were positive in IFA tests and 6 were positive in CSP tests. These results suggest that the ISI assay will be useful for evaluating naturally acquired protective anti-sporozoite antibodies in endemic areas, particularly during vaccine efficacy studies using sporozoite-based vaccines.

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DNA amplification techniques are being used increasingly in clinical laboratories to confirm the identity of medically important bacteria. A PCR-based identification method has been in use in our centre for 10 years for Burkholderia pseudomallei and was used to confirm the identity of bacteria isolated from cases of melioidosis in Ceará since 2003. This particular method has been used as a reference standard for less discriminatory methods. In this study we evaluated three PCR-based methods of B. pseudomallei identification and used DNA sequencing to resolve discrepancies between PCR-based results and phenotypic identification methods. The established semi-nested PCR protocol for B. pseudomallei 16-23s spacer region produced a consistent negative result for one of our 100 test isolates (BCC #99), but correctly identified all 71 other B. pseudomallei isolates tested. Anomalous sequence variation was detected at the inner, reverse primer binding site for this method. PCR methods were developed for detection of two other B. pseudomallei bacterial metabolic genes. The conventional lpxO PCR protocol had a sensitivity of 0.89 and a specificity of 1.00, while a real-time lpxO protocol performed even better with sensitivity and specificity of 1.00, and 1.00. This method identified all B. pseudomallei isolates including the PCR-negative discrepant isolate. The phaC PCR protocol detected the gene in all B. pseudomallei and all but three B. cepacia isolates, making this method unsuitable for PCR-based identification of B. pseudomallei. This experience with PCR-based B. pseudomallei identification methods indicates that single PCR targets should be used with caution for identification of these bacteria, and need to be interpreted alongside phenotypic and alternative molecular methods such as gene sequencing.

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The transmission of malaria in Brazil is heterogeneous throughout endemic areas and the presence of asymptomatic Plasmodium sp. carriers (APCs) in the Brazilian Amazon has already been demonstrated. Malaria screening in blood banks is based on the selection of donors in respect to possible risks associated with travel or residence, clinical evidence and/or inaccurate diagnostic methods thereby increasing the probability of transfusion-transmitted infection. We evaluated the frequency of APCs in four blood services in distinct areas of the Brazilian Amazon region. DNA was obtained from 400 human blood samples for testing using the phenol-chloroform method followed by a nested-PCR protocol with species-specific primers. The positivity rate varied from 1 to 3% of blood donors from the four areas with an average of 2.3%. All positive individuals had mixed infections for Plasmodium vivax and Plasmodium falciparum. No significant differences in the results were detected among these areas; the majority of cases originated from the transfusion centres of Porto Velho, Rondônia State and Macapá, Amapá State. Although it is still unclear whether APC individuals may act as reservoirs of the parasite, efficient screening of APCs and malaria patients in Brazilian blood services from endemic areas needs to be improved.

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Jorge Lobo's disease is a cutaneous and subcutaneous mycosis that affects patients in the Amazon region. The number of patients is relatively small, but the real situation of the disease as public health problem is not known, because Jorge Lobo's disease is not a notifiable disease. This study aims to report the clinical evolution in patients affected and to determine the prevalence and areas of occurrence of the disease. A retrospective study was carried out based on the analysis of the clinical records, which included a collection of photographs of patients in the Department of Sanitary Dermatology, in Rio Branco, and patients seen in the interior of the state. In a decade, in Rio Branco, 249 cases of the disease were reported, 30 were females and 219 males. Of these patients, 153 had localized lesions, 94 of them were on one ear, 55 had multifocal lesions and 41 had disseminated lesions. The average time between the onset of symptoms and diagnosis was 19 years. The average age at the time of diagnosis was 53 years, and ages ranged from 14 to 96 years.

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A cross-sectional study on prevalence, associated factors and genotype distribution of HCV infection was conducted among 848 HIV-infected patients recruited at reference centers in the Midwest Region of Brazil. The prevalence rate of HIV-HCV coinfection was 6.9% (95% CI: 5.2 to 8.6). In multivariable analysis, increasing age, use of illicit drugs (injection and non-injection), a history of blood transfusion before 1994, and the absence of a steady partnership were significant independent associated factors for HIV-HCV coinfection. The phylogenetic analysis based on the NS5B region revealed the presence of two major circulating genotypes of HCV: genotypes 1 (58.3%) and 3 (41.7%). The prevalence of HIV-HCV coinfection was lower than those reported in studies conducted with HIV-infected patients in different regions of Brazil, due to the fact that illicit drug use is not a frequent mode of HIV transmission in this region of Brazil. Serologic screening of HIV-patients for HCV before initiating antiretroviral treatment, a comprehensive identification of associated factors, and the implementation of effective harm reduction programs are highly recommended to provide useful information for treatment and to prevent HCV coinfection in these patients.

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Introduction The aim of this study was to establish the incidence rates of congenital syphilis in the South Region of Brazil from 2001 to 2009. Methods Temporal ecological and descriptive study based on the cases recorded by the System of Information of Notifiable Diseases. Results The incidence of congenital syphilis has been increasing in the South Region of Brazil since 2004; the highest incidence rates were in women who received prenatal care (113.5 new cases per 100,000 births, p<0.001), who were diagnosed with syphilis at pregnancy (69.8 new cases per 100,000 births, p=0.001), and whose partner did not undergo treatment for syphilis (53.1 new cases per 100,000 births, p=0.001). Conclusions The population of the present study mostly consisted of adult black women with low educational levels who attended prenatal care, who were diagnosed with syphilis during pregnancy, and whose partners were not treated for syphilis. Based on these results, actions are recommended to reduce the incidence of this disease, which is preventable by early diagnosis and appropriate treatment. The present was merely an ecological study; therefore, further investigations are necessary to elucidate the causes of these findings.

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Larval development of the freshwater shrimp Pseudopalaemon amazonensis Ramos-Porto was studied in the laboratory based on the offspring of ovigerous females collected in a small “terra-firme” forest stream near Manaus, Brazil. Ovigerous females with a mean total length of 36.5 ± 1.9 mm carried 13-19 eliptical, yolk-rich eggs measuring 2.55 ± 0.16 x 1.64 ± 0.11 mm. The larval period consisted of 3 benthie stages and the larvae accomplished metamorphosis after 7-8 days without feeding. The newly-hatched larva had sessile eyes and all appendages, except for the uropods; chelipeds were present as uniramous buds, but walking legs were fully developed and functional. Descriptions and illustrations of the 3 larval and first juvenile stages are presented.

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With this work, the authors wish to show some of the alterations in the pattern of relations between society and nature, which have taken place throughout the 20th century in the Parauapebas and Itacaiúnas river valleys, as well as in parts of the Tocantins River valley, in southeastern Pará. This is accomplished through descriptions based on Coudreau's first-hand accounts (1889), transcribed in "Voyage a Itaboca et a L'Itacayuna", published in 1897, which depicts an area almost totally covered by forest. This is followed by a counter view made possible through the LandSat 5 satellite sensors, with images of those valleys in 2001, showing the consequences of society transformations and pressure on natural resources, and above all the dramatic decrease in the size of the forest, reduced to 52 percent of the 63,000 square kilometers analyzed herein.

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ABSTRACTIn the Amazon, river navigation is very important due to the length of navigable rivers and the lack of alternative road networks. Boats usually operate in unfavorable conditions, since there is no hydrodynamic relation among propellers, geometry, and the dimensions of the boat hull. Currently, there is no methodology for propeller hydrodynamic optimization with low computational cost and easy implementation in the region. The aim of this work was to develop a mathematical approach for marine propeller design applied to boats typically found on Amazon rivers. We developed an optimized formulation for the chord and pitch angle distributions, taking into account the classical model of Glauert. A theoretical analysis for the thrust and torque relationships on an annular control volume was performed. The mathematical model used was based on the Blade Element Momentum Theory (BEMT). We concluded that the new methodology proposed in this work demonstrates a good physical behavior when compared with the theory of Glauert and the experimental data of the Wageningen B3-50 propeller.

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OBJECTIVE: To describe echocardiographic measurements and left ventricular mass in a population sample of healthy adults inhabitants of the urban region of Porto Alegre. METHODS: An analytical, observational, population-based, cross-sectional study was done. Through a multi-stage probability sample, 114 individuals were selected to be submitted to a M-mode and two-dimensional echocardiogram with color Doppler. The analyses were restricted to healthy participants. Echocardiographic measurements were described by mean, standard deviation, 95 percentile and 95% confidence limits. RESULTS: A total of 100 healthy participants, with several characteristics similar to those from the original population, had a complete and reliable echocardiographic examination. The measurements of aorta, left atrium, interventricular septum, left ventricle in systole and diastole, left posterior wall and left ventricular mass, adjusted or not for body surface area or height, were significantly higher in males. The right ventricle size was similar among the genders. Several echocardiographic measurements were within standard normal limits. Interventricular septum, left posterior wall and left ventricular mass, adjusted or not for anthropometric measurements, and aortic dimensions had lower mean and range than the reference limits. CONCLUSION: The means and estimates of distribution for the measurements of interventricular septum, left posterior wall and left ventricular mass found in this survey were lower than those indicated by the international literature and accepted as normal limits.

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A new species of Thaumastus (Thaumastus) Martens, 1860, from Minas Gerais State, Brazil, is described and illustrated, based on the morphology of the shell, jaw, radula and soft parts.

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Based on field observations and pitfall sampling, we determined the species richness, relative abundance, and reproductive habitat of terrestrial frogs in three municipalities in the Triângulo Mineiro region, south Cerrado biome, in southeastern Brazil. We found thirty-two species of terrestrial frogs, belonging to the families Brachycephalidae, Bufonidae, Cycloramphidae, Dendrobatidae, Leiuperidae, Leptodactylidae and Microhylidae. Most of the species were found in open areas and reproduced in human-generated environments, such as artificial lakes (10 species) and ponds (14 species). Dominance was high, with Physalaemus cuvieri Fitzinger, 1826 (Leiuperidae) representing 48% of sampled frogs. A larger number of individuals was captured in the wet season, when most of the species were reproducing. Compared to other areas of Cerrado biome, the Triângulo Mineiro sites presented a larger number of species, which may be attributed to the larger sampled area and greater sampling effort, lower altitude and presence of human generated habitats. The richness of terrestrial frogs was also larger than that in some forested localities in southeastern Brazil, indicating that the number of species cannot be explained only by precipitation and type of vegetation cover. The greater abundance of individuals during the wet season may be related to a greater movement of adults to breeding sites and to juvenile recruitment/dispersion. The heterogeneity of environments in the Cerrado biome, including its several isolated highlands, contributes to its high (local and regional) diversity of frogs.

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The aim of the present study was to determine the size at sexual maturity in the freshwater crab Dilocarcinus pagei Stimpson, 1861, from a population located in Mendonça, state of São Paulo, Brazil. The crabs were sampled monthly (July 2005 to June 2007), at Barra Mansa reservoir. The specimens were captured manually or in sieves passed through the aquatic vegetation. The crabs were captured and separated by sex based on morphology of the pleon and on the number of pleopods. The following dimensions were measured: carapace width (CW); carapace length (CL); propodus length (PL); and abdomen width (AW). The morphological analysis of the gonads was used to identify and categorize individuals according to their stage of development. The morphological maturity was estimated based on the analysis of relative growth based on the allometric equation y = ax b. The gonadal maturity was based on the morphology of the gonads by the method CW50 which indicates the size at which 50% of the individuals in the population showed gonads morphologically mature to reproduction. The biometric relationships that best demonstrated the different patterns of growth for the juvenile and adult stages were CW vs. PL for males and CW vs. AW for females (p<0.001). Based on these relationships, the estimated value to morphological sexual maturity was 21.5 mm (CW) in males and 19.7 mm (CW) in females. The determination of the size at sexual maturity and the adjustment of the data based on the logistic curve (CW50) resulted in a size of 38.2 mm for males and 39.4 mm for females (CW). Based on the data obtained for sexual maturity for D. pagei, we can estimate a minimum size for capture of 40 mm (CW). This minimum size allows at least half of the population to reproduce and retains the juveniles and a portion of the adults in the population.

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This paper discusses current evidence for the relationship between polyclonal lymphocyte activation, specific immunossupression with decreased resistance, and autoimmune pathology, that are all often found associated with infections by a variety of virus, bacteria and parasites . The central question of class determination of immune effector activities is considered in the context of the cellular targets for nonspecific mitogenic activities associated with infection. A model is presented to integrate these findings: mitogenens produced by the microorganism or the infected cells are preferentially active on CD5 B cells, the resulting over-production of IL-10 will tend to bias all immune activities in to a Th-2mode of effector functions, with high titers of polyclonal antibodies and litle or no production of gamma IFN and other "inflamatory"lymphokines that often mediate resistance. In turn these conditions allow for parasite persistence and the corresponding long-term disregulation of self-directed immune reactivities, resulting in autoimmunity in the chronic phase. This model would predict that selective immunization with the mitogenic principles involved in desregulation, could stand better chances than strategies of vaccination based on immunopotentiation against othere, functionally neutral antigenic epitopes. It is argued, however, that the complexity of immune responses and their regulation together with our ignorance on the genetic controls of class-determination, offer poor prospects for a scientifically-based, rational development of vaccines in the near future. It is suggested that empirically-based and technologically developed vaccines might suceed, while basic scientific approaches are reinforced and given the time provide a better understanding of those process.

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A new Neotropical species of biting midge Culicoides (Haematomyidium), C. kampa Felippe-Bauer, Veras & Castellon, is described and illustrated based on female specimens from the Amazonian Region.