993 resultados para visible region
Resumo:
We present filaria-nested polymerase chain reaction (PCR), which is based on amplification of first internal transcribed spacer rDNA to distinguish three parasitic filarial species (Onchocerca volvulus, Mansonella ozzardiand Mansonella perstans) that can be found in the Amazon Region. Nested PCR-based identifications yielded the same results as those utilizing morphological characters. Nested PCR is highly sensitive and specific and it detects low-level infections in both humans and vectors. No cross-amplifications were observed with various other blood parasites and no false-positive results were obtained with the nested PCR. The method works efficiently with whole-blood, blood-spot and skin biopsy samples. Our method may thus be suitable for assessing the efficacy of filaria control programmes in Amazonia by recording parasite infections in both the human host and the vector. By specifically differentiating the major sympatric species of filaria, this technique could also enhance epidemiological research in the region.
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As in humans, sub-clinical infection by arboviruses in domestic animals is common; however, its detection only occurs during epizootics and the silent circulation of some arboviruses may remain undetected. The objective of the present paper was to assess the current circulation of arboviruses in the Nhecolândia sub-region of South Pantanal, Brazil. Sera from a total of 135 horses, of which 75 were immunized with bivalent vaccine composed of inactive Eastern equine encephalitis virus (EEEV) and Western equine encephalitis virus(WEEV) and 60 were unvaccinated, were submitted to thorough viral isolation, reverse transcriptase polymerase chain reaction (RT-PCR) and neutralization tests for Saint Louis encephalitis virus (SLEV), EEEV, WEEV and Mayaro virus (MAYV). No virus was isolated and viral nucleic-acid detection by RT-PCR was also negative. Nevertheless, the prevalence of neutralizing antibodies in horses older than seven months was 43.7% for SLEV in equines regardless of vaccine status, and 36.4% for WEEV and 47.7% for EEEV in unvaccinated horses. There was no evidence of MAYV infections. The serologic evidence of circulation of arboviruses responsible for equine and human encephalitis, without recent official reports of clinical infections in the area, suggests that the Nhecolândia sub-region in South Pantanal is an important area for detection of silent activity of arboviruses in Brazil.
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A new species of the Culicoides reticulatus species group, Culicoides kuripako Felippe-Bauer, is described and illustrated based on females and male specimens from the states of Amazonas and Pará, Brazil. The new species is compared with its similar sympatric congener, Culicoides paucienfuscatus Barbosa.
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An understanding of the taxonomic status and vector distribution of anophelines is crucial in controlling malaria. Previous phylogenetic analyses have supported the description of six species of the Neotropical malaria vector Anopheles (Nyssorhynchus) albitarsis s.l. (Diptera: Culicidae): An. albitarsis, Anopheles deaneorum, Anopheles marajoara, Anopheles oryzalimnetes, Anopheles janconnae and An. albitarsis F. To evaluate the taxonomic status of An. albitarsis s.l. mosquitoes collected in various localities in the Colombian Caribbean region, specimens were analyzed using the complete mitochondrial DNA cytochrome oxidase I (COI) gene, the ribosomal DNA (rDNA) internal transcribed spacer 2 (ITS2) region and partial nuclear DNA white gene sequences. Phylogenetic analyses of the COI gene sequences detected a new lineage closely related to An. janconnae in the Caribbean region of Colombia and determined its position relative to the other members of the complex. However, the ITS2 and white gene sequences lacked sufficient resolution to support a new lineage closely related to An. janconnae or the An. janconnae clade. The possible involvement of this new lineage in malaria transmission in Colombia remains unknown, but its phylogenetic closeness to An. janconnae, which has been implicated in local malaria transmission in Brazil, is intriguing.
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Parasites remain competent invaders of host immunity. Their invasion strategies have proven to impact immunorelevant genes leading to diversity among gene families. We focussed on signal transducer and activator of transcription (STAT6) factor that plays a fundamental role in signal transduction and activation of transcription. Recent studies have highlighted the role of STAT6 variants in control of infection levels. We identified and investigated regulatory single nucleotide polymorphisms (SNPs) in the promoter regions of the STAT6 gene in a group of Gabonese individuals exposed to a variety of parasitic infections. Three promoter variants were identified in 40 individual subjects. We further validated these promoter variants for their allelic gene expression using transient transfection assays. One promoter variant, rs3024944 (G/C), revealed an altered expression of the marker gene. The identification of function-altering SNPs in the promoter may facilitate studying parasite susceptibility in association studies.
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Streblidae flies are specialised parasites of bat hosts, mainly phyllostomids. There is a high richness of streblids in the savannah-like Cerrado region; however, there is little quantitative data available in parasitological indices. Here, we describe the component community, prevalence and intensity of a streblid infestation on a phyllostomid bat assemblage in Serra da Bodoquena, a Cerrado region in Southwest Brazil. We conducted surveys by capturing and inspecting bat hosts during the seven-month period between October 2004-December 2005. All the ectoparasites found on the bats were collected in the field and then counted and identified in the laboratory. We captured 327 bats belonging to 13 species, of which eight species were parasitized by 17 species of streblids. Carollia perspicillata and Glossophaga soricina were infested with seven streblid species, whereas the other bat species were infested with four or fewer streblid species. Megistopoda proxima and Aspidoptera falcata flies were found on Sturnira lilium, and Trichobius joblingi was the most prevalent fly on C. perspicillata. Megistopoda aranea and Aspidoptera phyllostomatis were highly prevalent and had a high intensity of infestation on Artibeus planirostris. Overall comparisons of the available data suggest that the component communities of streblids vary more between the Cerrado and Atlantic Forest phytogeographical regions than between localities within the same phytogeographical region.
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In visceral leishmaniasis, phlebotomine vectors are targets for control measures. Understanding the ecosystem of the vectors is a prerequisite for creating these control measures. This study endeavours to delineate the suitable locations of Phlebotomus argentipes with relation to environmental characteristics between endemic and non-endemic districts in India. A cross-sectional survey was conducted on 25 villages in each district. Environmental data were obtained through remote sensing images and vector density was measured using a CDC light trap. Simple linear regression analysis was used to measure the association between climatic parameters and vector density. Using factor analysis, the relationship between land cover classes and P. argentipes density among the villages in both districts was investigated. The results of the regression analysis indicated that indoor temperature and relative humidity are the best predictors for P. argentipes distribution. Factor analysis confirmed breeding preferences for P. argentipes by landscape element. Minimum Normalised Difference Vegetation Index, marshy land and orchard/settlement produced high loading in an endemic region, whereas water bodies and dense forest were preferred in non-endemic sites. Soil properties between the two districts were studied and indicated that soil pH and moisture content is higher in endemic sites compared to non-endemic sites. The present study should be utilised to make critical decisions for vector surveillance and controlling Kala-azar disease vectors.
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Myxidium volitans sp. nov. (Myxozoa: Myxidiidae) parasitizing the hypertrophied green-brownish gallbladder of the teleost Dactylopterus volitans, collected in the Atlantic coast near Niterói, Brazil was described based on ultrastructural studies. The spores were fusiform, sometimes slightly crescent-shaped on average 21.7 ± 0.3 µm (mean ± standard deviation) (n = 50) long and 5.6 ± 0.4 µm (n = 30) wide. The spore wall was thin and smooth, comprising two equally-sized valves joined by a hardly visible sutural ridge. Spores containing two pyriform polar capsules (PC) (5.0 ± 0.4 × 2.3 ± 0.3 µm) (n = 30) are situated in each extremity of the spore. The PC wall was composed of hyaline layer (0.20-0.29 µm thick) and by a thin external granular layer. Each PC contains a polar filament (PF) with irregular arrangements that was projected from its apical region to the bases of PC and coiled laterally from bases to the tip of PC. Some regular striations and S-like structures in the periphery of the PFs with four-five irregular sections were observed. Based on the spore morphology, ultrastructural differences and the specificity of the host we describe this parasite as a new myxosporidian, named M. volitans sp. nov.
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We report two ciprofloxacin and ofloxacin-resistant Neisseria gonorrhoeae strains that were isolated from the urethral discharge of male patients at the sexually transmitted diseases outpatient clinic of the Alfredo da Matta Foundation (Manaus, state of Amazonas, Brazil). The gonococci displayed minimal inhibitory concentrations (> 32.00 µg/mL) and three mutations in the quinolone resistance-determining region (S91F and D95G in GyrA and S87R in ParC). Both isolates were genotyped using N. gonorrhoeae multi-antigen sequence typing and the analysis showed that the ST225 which represented an emerging widespread multi-resistant clone that has also been associated with reduced susceptibility to ceftriaxone. We recommend continued surveillance of this pathogen to assess the efficacy of anti-gonococcal antibiotics in Brazil.
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Leprosy and hepatitis B virus (HBV) are highly endemic in some regions of the state of Mato Grosso, in central Brazil. The association of leprosy with HBV and hepatitis C virus (HCV) was assessed using a seroprevalence study and 191 leprosy outpatients were included. Demographic data and the clinical classification of leprosy were recorded. Evidence of previous HBV infection was present in 53 patients (27.7%, 95% confidence interval: 21.9-34.5) and two (1%) were HBsAg positive. Five (2.6%) had antibodies to HCV. The prevalence of previous exposure to HBV was higher than expected for an adult population in central Brazil. In contrast, the prevalence of anti-HCV antibodies was not much higher regarding the age range of participants. HBV markers were associated with a higher number of sex partners and the use of injections without proper sterilisation of the syringes. The number of HBV carriers was small, suggesting that there was no increased likelihood of chronification among these patients.
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Geological research on the Mediterranean region is presently characterized by the transition from disciplinary to multidisciplinary research, as well as from national to international investigations. In order to synthesize and integrate the vast disciplinary and national datasets which are available, it is necessary to implement maximum interaction among geoscientists of different backgrounds. The creation of project-oriented task forces in universities and other research institutions, as well as the development of large international cooperation programs, is instrumental in pursuing such a multidisciplinary and supranational approach. The TRANSMED Atlas, an official publication of the 32nd International Geological Congress (Florence 2004), is the result of an international scientific cooperation program which brought together for over two years sixty-three structural geologists, geophysicists, marine geologists, petrologists, sedimentologists, stratigraphers, paleogeographers, and petroleum geologists coming from eighteen countries, and working for the petroleum industry, academia, and other institutions, both public and private. The TRANSMED Atlas provides an updated, synthetic, and coherent portrayal of the overall geological-geophysical structure of the Mediterranean domain and the surrounding areas. The initial stimulus for the Atlas came from the realization of the extremely heterogeneous nature of the existing geological-geophysical data about such domain. These data have been gathered by universities, oil companies, geological surveys and other institutions in several countries, often using different procedures and standards. In addition, much of these data are written in languages and published in outlets that are not readily accessible to the general international reader. By synthesizing and integrating a wealth of preexisting and new data derived from surficial geology, seismic sections at various scales, and mantle tomographies, the TRANSMED Atlas provides for the first time a coherent geological overview of the Mediterranean region and represents an ideal springboard for future studies.
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The histo-blood group ABH antigens were first described in humans. These antigens are only present on erythrocytes from great apes and humans, while in more primitive animals they are found in tissues and body fluids. The ABH antigens are mainly distributed in tissues exposed to the external environment and potentially serve as ligands for pathogens or inhibitors of tissue connections. The objective of this paper was two-fold: (i) to determine the presence of Helicobacter sp. in the gastric mucosa of 16 captive and 24 free-living New World monkeys and (ii) to evaluate the presence of histopathological alterations related to bacterial infection and the associated expression of ABH antigens in the tissue. Stomach tissues from 13 species of monkey were assessed using haematoxylin-eosin and modified Gram staining (Hucker) methods. An immunohistochemical analysis of the tissue revealed the presence of infectious bacteria that were characteristic of the genus Helicobacter sp. The results demonstrate that various species of monkey might be naturally infected with the Helicobacter sp. and that there is an increased susceptibility to infection. This study serves as a comparative analysis of infection between human and non-human primates and indicates the presence of a new species of Helicobacter.
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Internet it is a powerful interactive communication channel with world scope, through which can be multiplied the visibility of the research of the professionals whose scientific production has a difficult diffusion by the conventionals media. It is presented an analysis of the scientific publications observed in the web in order to understand the different communication processes accomplished by the superior corps of environmental health technical of the Andalusian Health Service. Using the nominal relationship of the professionals, we used Google ‘search engine’ for all scientific publications located in the internet; we were made different bibliometric indicators as of the recovered records and was analyzed the time evolution of the scientific production, documental categories, geografic distribution, language, coauthors and institutional collaboration. It was identified a growing trend in the productivity of the publications in the last decade, mainly through communications to congresses (70.4%) and journals articles (16.9%). The publications mainly are located in spanish journals, that they are indexed on national and international databases. In all the Andalusian provinces was identified some published scientific communication. The indicator of coauthors is very high (95.77%) although the institutional participation is limited mainly to the primary attention districts, occupational centers of each professional (85.21%). The scientific publication patterns visualized in the web represent an important contribution for the knowledge of the characteristics of the environmental health professionals of the Andalusian health service, what provides avaluable information for the support of the information systems in public health.
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BACKGROUND: The human herpes simplex virus-associated host cell factor 1 (HCF-1) is a conserved human transcriptional co-regulator that links positive and negative histone modifying activities with sequence-specific DNA-binding transcription factors. It is synthesized as a 2035 amino acid precursor that is cleaved to generate an amino- (HCF-1(N)) terminal subunit, which promotes G1-to-S phase progression, and a carboxy- (HCF-1(C)) terminal subunit, which controls multiple aspects of cell division during M phase. The HCF-1(N) subunit contains a Kelch domain that tethers HCF-1 to sequence-specific DNA-binding transcription factors, and a poorly characterized so called "Basic" region (owing to a high ratio of basic vs. acidic amino acids) that is required for cell proliferation and has been shown to associate with the Sin3 histone deacetylase (HDAC) component. Here we studied the role of the Basic region in cell proliferation and G1-to-S phase transition assays. METHODOLOGY/PRINCIPAL FINDINGS: Surprisingly, much like the transcriptional activation domains of sequence-specific DNA-binding transcription factors, there is no unique sequence within the Basic region required for promoting cell proliferation or G1-to-S phase transition. Indeed, the ability to promote these activities is size dependent such that the shorter the Basic region segment the less activity observed. We find, however, that the Basic region requirements for promoting cell proliferation in a temperature-sensitive tsBN67 cell assay are more stringent than for G1-to-S phase progression in an HCF-1 siRNA-depletion HeLa-cell assay. Thus, either half of the Basic region alone can support G1-to-S phase progression but not cell proliferation effectively in these assays. Nevertheless, the Basic region displays considerable structural plasticity because each half is able to promote cell proliferation when duplicated in tandem. Consistent with a potential role in promoting cell-cycle progression, the Sin3a HDAC component can associate independently with either half of the Basic region fused to the HCF-1 Kelch domain. CONCLUSIONS/SIGNIFICANCE: While conserved, the HCF-1 Basic region displays striking structural flexibility for controlling cell proliferation.