43 research outputs found

    Finding connections in the unexpected detection of Plasmodium vivax and Plasmodium falciparum DNA in asymptomatic blood donors: a fact in the Atlantic Forest

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    Abstract\ud A recent paper in Malaria Journal reported the observation of unexpected prevalence rates of healthy individuals carrying Plasmodium falciparum (5.14%) or Plasmodium vivax (2.26%) DNA among blood donors from the main transfusion centre in the metropolitan São Paulo, a non-endemic area for malaria. The article has been challenged by a group of authors who argued that the percentages reported were higher than those found in blood banks of the endemic Amazon Region and also that that paper had not considered the literature on the classical dynamics of malaria transmission in the Atlantic Forest, which involves Anopheles (Kerteszia) cruzii and bromeliad malaria, due to P. vivax and Plasmodium malariae parasites, but not P. falciparum. The present commentary paper responds to this challenge and brings evidence and literature data supporting that the observed prevalence ratios may indicate a proportion of individuals that are exposed to Plasmodium transmission in permissive environments; that blood carrying parasite DNA may not be necessarily infective if used in transfusion; and that in the literature, there are examples supporting the circulation of P. falciparum in the area.FAPES

    Plasmodium falciparum in the southeastern Atlantic forest: a challenge to the bromeliad-malaria paradigm?

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    Abstract\ud \ud Background\ud Recently an unexpectedly high prevalence of Plasmodium falciparum was found in asymptomatic blood donors living in the southeastern Brazilian Atlantic forest. The bromeliad-malaria paradigm assumes that transmission of Plasmodium vivax and Plasmodium malariae involves species of the subgenus Kerteszia of Anopheles and only a few cases of P. vivax malaria are reported annually in this region. The expectations of this paradigm are a low prevalence of P. vivax and a null prevalence of P. falciparum. Therefore, the aim of this study was to verify if P. falciparum is actively circulating in the southeastern Brazilian Atlantic forest remains.\ud \ud \ud Methods\ud In this study, anophelines were collected with Shannon and CDC-light traps in seven distinct Atlantic forest landscapes over a 4-month period. Field-collected Anopheles mosquitoes were tested by real-time PCR assay in pools of ten, and then each mosquito from every positive pool, separately for P. falciparum and P. vivax. Genomic DNA of P. falciparum or P. vivax from positive anophelines was then amplified by traditional PCR for sequencing of the 18S ribosomal DNA to confirm Plasmodium species. Binomial probabilities were calculated to identify non-random results of the P. falciparum-infected anopheline findings.\ud \ud \ud Results\ud The overall proportion of anophelines naturally infected with P. falciparum was 4.4% (21/480) and only 0.8% (4/480) with P. vivax. All of the infected mosquitoes were found in intermixed natural and human-modified environments and most were Anopheles cruzii (22/25 = 88%, 18 P. falciparum plus 4 P. vivax). Plasmodium falciparum was confirmed by sequencing in 76% (16/21) of positive mosquitoes, whereas P. vivax was confirmed in only 25% (1/4). Binomial probabilities suggest that P. falciparum actively circulates throughout the region and that there may be a threshold of the forested over human-modified environment ratio upon which the proportion of P. falciparum-infected anophelines increases significantly.\ud \ud \ud Conclusions\ud These results show that P. falciparum actively circulates, in higher proportion than P. vivax, among Anopheles mosquitoes of fragments of the southeastern Brazilian Atlantic forest. This finding challenges the classical bromeliad-malaria paradigm, which considers P. vivax circulation as the driver for the dynamics of residual malaria transmission in this region.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP Grant 2011/20397-7), (Grant 2009/53141-5), (Grant 012/09939-5) e (Grant 2014/09774-1)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq no. 301666/2011-3

    Uncommon allele in APO AI-CIII-AIV gene cluster in a family with congenital generalized lipodystrophy

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    Congenital generalized lipodystrophy is a rare inherited disease. One of its features is a disturbance in lipid metabolism characterized by hypercholesterolemia and hypertriglyceridemia. A brother and a sister with congenital generalized lipodystrophy, an 8-year old male and a 12-year old female were studied. The mother and a 6-year old brother were healthy. The genetic analysis of Sstl RFLP of the apo Al-CIII-AIV gene cluster showed the presence of the rare Sstl allele (S2) in the patients but not in the healthy mother and brother. As this uncommon allele has been reported to be related to high plasma triglyceride levels, this association could be relevant in explaining in part the hypertriglyceridemia observed in these patients

    Gametic phase disequilibrium between the syntenic multiallelic HTG4 and HMS3 markers widely used for parentage testing in Thoroughbred horses

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    Validation of parentage and horse breed registries through DNA typing relies on estimates of random match probabilities with DNA profiles generated from multiple polymorphic loci. Of the twenty-seven microsatellite loci recommended by the International Society for Animal Genetics for parentage testing in Thoroughbred horses, eleven are located on five chromosomes. An important aspect in determining combined exclusion probabilities is the ascertainment of the genetic linkage status of syntenic markers, which may affect reliable use of the product rule in estimating random match probabilities. In principle, linked markers can be in gametic phase disequilibrium (GD). We aimed at determining the extent, by frequency and strength, of GD between the HTG4 and HMS3 multiallelic loci, syntenic on chromosome 9. We typed the qualified offspring (n (1) = 27; n (2) = 14) of two Quarter Bred stallions (registered by the Brazilian Association of Quarter Horse Breeders) and 121 unrelated horses from the same breed. In the 41 informative meioses analyzed, the frequency of recombination between the HTG4 and HMS3 loci was 0.27. Consistent with genetic map distances, this recombination rate does not fit to the theoretical distribution for independently segregated markers. We estimated sign-based D' coefficients as a measure of GD, and showed that the HTG4 and HMS3 loci are in significant, yet partial and weak, disequilibrium, with two allele pairs involved (HTG4*M/HMS3*P, D'(+) = 0.6274; and HTG4*K/HMS3*P, D'(-) = -0.6096). These results warn against the inadequate inclusion of genetically linked markers in the calculation of combined power of discrimination for Thoroughbred parentage validation.CNPqCNPqFAPERJFAPERJFAPESPFAPESPNucleo de Diagnostico e Investigacao Molecular of the Universidade Estadual do Norte Fluminense Darcy RibeiroNucleo de Diagnostico e Investigacao Molecular of the Universidade Estadual do Norte Fluminense Darcy Ribeir

    HEXOSAMINE CONTENT OF THE ARTERIAL-WALL AND PLASMA IN RATS SUBJECTED TO RECOVERY FROM PROTEIN UNDERNOURISHMENT - INFLUENCE OF DIETETIC CHOLESTEROL

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    SCH MED SAO PAULO,SAO PAULO,SP,BRAZILESCOLA PAULISTA MED,SAO PAULO 04023,SP,BRAZILESCOLA PAULISTA MED,SAO PAULO 04023,SP,BRAZILWeb of Scienc

    Snake Venom Extracellular vesicles (SVEVs) reveal wide molecular and functional proteome diversity

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    Abstract Proteins constitute almost 95% of snake venom’s dry weight and are produced and released by venom glands in a solubilized form during a snake bite. These proteins are responsible for inducing several pharmacological effects aiming to immobilize and initiate the pre-digestion of the prey. This study shows that proteins can be secreted and confined in snake venom extracellular vesicles (SVEVs) presenting a size distribution between 50 nm and 500 nm. SVEVs isolated from lyophilized venoms collected from four different species of snakes (Agkistrodon contortrix contortrix, Crotalus atrox, Crotalus viridis and Crotalus cerberus oreganus) were analyzed by mass spectrometry-based proteomic, which allowed the identification of proteins belonging to eight main functional protein classes such as SVMPs, serine proteinases, PLA2, LAAO, 5′nucleotidase, C-type lectin, CRISP and Disintegrin. Biochemical assays indicated that SVEVs are functionally active, showing high metalloproteinase and fibrinogenolytic activity besides being cytotoxic against HUVEC cells. Overall, this study comprehensively depicts the protein composition of SVEVs for the first time. In addition, the molecular function of some of the described proteins suggests a central role for SVEVs in the cytotoxicity of the snake venom and sheds new light in the envenomation process
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