992 resultados para PCR-restriction fragment length polymorphism (RFLP)


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Objective: To investigate the prevalence of infection, disease and eventual institutional outbreak of tuberculosis in a psychiatric hospital using the PPD test, as well as testing for mycobacteria in material collected from the respiratory tree and using molecular tracking technique based on insertion sequence 6110 (IS6110). Methods: Between February and August of 2002, PPD tests were given to 74 inpatients and 31 staff members at a psychiatric hospital in the city of Rio Verde, located in the state of Goiás, Brazil. In addition, respiratory tree material collected from the inpatients was submitted to testing for Mycobacterium tuberculosis. Results: Among the patients analyzed, mycobacteria were isolated from five (6.8%): four identified as M. tuberculosis and one as M. chelonae. The M. tuberculosis isolates were sensitive to isoniazid and rifampicin, and, when submitted to the restriction fragment length polymorphism/IS6110 technique, presented unique genetic profiles, totally distinct from one another, suggesting that all of the tuberculosis cases were due to endogenous reactivation. It was not possible to characterize this group of cases as an institutional outbreak. Performing the two-step tuberculin test in the patients, the infection rates were 23% and 31%, compared with 42% among staff members, who were submitted to the one-step test. Conclusion: The results indicate a high incidence of tuberculosis infection among inpatients and hospital staff, as well as a high occurrence of the disease among inpatients.

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Malaria is an endemic parasitosis and its causitive agent, Plasmodium, has a metabolism linked to iron supply. HFE is a gene with the polymorphisms C282Y and H63D, which are associated with a progressive iron accumulation in the organism leading to a disease called hereditary hemochromatosis. The aim of the present study was to determine the allelic and genotypic frequencies of the HFE gene polymorphisms in malaria patients and blood donors from the Brazilian Amazon region. We screened 400 blood donors and 400 malaria patients for the HFE C282Y and H63D polymorphisms from four states of the Brazilian Amazon region by polymerase chain reaction and restriction fragment length polymorphism analysis. We did not find any C282Y homozygous individuals, and the only five heterozygous individuals detected were from Pará State. The most frequent genotype in the North region of Brazil was the H63D heterozygote, in both study groups. Our results contribute to the concept that the Brazilian Amazon region should not be regarded as a single entity in South America. These polymorphisms did not influence the symptoms of malaria in the population studied, as neither severe signs nor high parasitemia were observed. Therefore, different hereditary hemochromatosis diagnostic and control measures must be developed and applied within its diverse locations. Investigations are currently being carried out in our laboratory in order to determine the importance of the coexistence of hereditary hemochromatosis in patients affected by parasitic diseases, such as malaria. ©FUNPEC-RP.

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Sickle cell disease is an inflammatory condition with a pathophysiology that involves vaso-occlusive episodes. Mutations of the methylenetetrahydrofolate reductase (MTHFR) and cystathionine beta-synthase (CBS) genes are risk factors for vascular disease. Due to the importance of identifying risk factors for vaso-occlusive events in sickle cell patients, we investigated the frequencies of the C677T and 844ins68 mutations of the MTHFR and CBS genes, respectively. Three hundred patients with Hb SS, HB SC and HbS/Beta thalassemia, from Brasília, Goiânia, Rio de Janeiro, São Jose do Rio Preto and São Paulo were evaluated. Samples of 5 mL of venous blood were collected in EDTA after informed consent was received from patients. Classical diagnostic methods were used to confirm the hemoglobin phenotypes. The hemoglobin genotypes and polymorphisms studied were evaluated by Restriction Fragment Length Polymorphism and Allele Specific amplification. The results showed that 93 patients (31.00%) were heterozygous and 13 (4.33%) homozygous for the C677T mutation and 90 were heterozygotes (30.00%) and 8 homozygous (2.66%) for the 844ins68 mutation, both with significant differences for genotype frequency between the localities. The allelic frequencies are in Hardy-Weinberg equilibrium for both polymorphisms. The frequency of mutations was significant and the presence of related vaso-occlusive events was more common in patients with Hb SS (p = 0007). The 844ins68 mutation was approximately three times more frequent in patients with vaso-occlusive complications (p = 0011). The C677T mutation did not prove to be associated with risk of vaso-occlusive events (p = 0.193). A C677T-844ins68 interaction occurred in 12.08% of the patients, doubling the risk of vaso-occlusive manifestations. The frequencies of the polymorphisms are consistent with those expected in the Brazilian population. The presence of the 844ins68 mutation of the CBS gene proved to be a potential risk factor for vaso-occlusive events in sickle cell patients.

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Este trabalho objetivou a caracterização molecular do vírus linfotrópico de células T humanas infectando doadores de sangue atendidos na Fundação Centro de Hemoterapia e Hematologia do Pará. Amostras de DNA de 79 indivíduos soropositivos para o vírus linfotrópico de células T humanas foram analisadas por meio da reação em cadeia da polimerase para as regiões genômicas pX, env e 5'LTR, de polimorfismos de comprimento de fragmentos de restrição e do seqüenciamento da região 5LTR, com posterior análise filogenética, definindo o tipo e o subtipo do HTLV circulante na população estudada. Observou-se uma maior prevalência de HTLV-1 (71%) em relação ao HTLV-2 (29%). As amostras de HTLV-1 sequenciadas foram classificadas como pertencentes ao subtipo Cosmopolita, subgrupo Transcontinental, sendo as de HTLV-2 identificadas como HTLV-2c. A análise de polimorfismos de comprimento de fragmentos de restrição da região env e do sequenciamento da região 5'LTR, identificou, pela primeira vez na Amazônia Brasileira, uma amostra de HTLV-2b, enfatizando a necessidade de estudos moleculares contínuos na região para melhor entendimento da epidemiologia de transmissão do HTLV na população e permitir a vigilância epidemiológica da emergência de novos tipos e subtipos.

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A distribuição geográfica da infecção pelo Vírus Linfotrópico de Células T HTLV 1/2 humanas 1 e 2 é ampla, porém existem áreas de maior endemicidade e também particularidades de acordo com o tipo de HTLV. O HTLV-1 apresenta maior soroprevalência no sudoeste do Japão, no Caribe, na América Central, nas diferentes regiões da América do Sul e nas porções centrais e ocidentais da África e Melanésia. Enquanto o HTLV-2 parece acometer grupos populacionais distintos, como as populações nativas de indígenas das Américas do Norte, Central e Sul, pigmeus da África Central, mongóis na Ásia e também usuários de drogas injetáveis. O trabalho realizado teve como objetivo descrever a epidemiologia molecular do HTLV em três populações distintas do estado do Amapá, que foram: pacientes HIV/AIDS infectado, população afro-descendente e finalmente indivíduos atendidos no Laboratório Central de Saúde Pública do Amapá (LACEN-AP), encaminhados para diagnóstico de HTLV. As amostras foram avaliadas para a presença do vírus por métodos sorológicos (ELISA e Western blot) e moleculares (amplificação gênica e caracterização de segmentos das regiões pX e env pela análise de polimorfismo de fragmentos de restrição por ação de endonuclease. Os resultados obtidos nas diferentes populações foram na população de indivíduos infectados pelo HIV/AIDS, todas as amostras foram negativas, na população afro-descendente, apenas uma amostra apresentou positividade na sorologia pelo método de ELISA, porém foi negativa no Western blot e quando submetida ao método molecular, não houve amplificação. No entanto, entre os indivíduos encaminhados para diagnóstico de HTLV, 06 (seis) amostras foram positivas, e dessas, 05 (cinco) foram confirmadas por Western blot e pelo método molecular. O resultado molecular demonstrou a presença de HTLV-1.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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We compared the microbial community composition in soils from the Brazilian Amazon with two contrasting histories; anthrosols and their adjacent non-anthrosol soils of the same mineralogy. The anthrosols, also known as the Amazonian Dark Earths or terra preta, were managed by the indigenous pre-Colombian Indians between 500 and 8,700 years before present and are characterized by unusually high cation exchange capacity, phosphorus (P), and calcium (Ca) contents, and soil carbon pools that contain a high proportion of incompletely combusted biomass as biochar or black carbon (BC). We sampled paired anthrosol and unmodified soils from four locations in the Manaus, Brazil, region that differed in their current land use and soil type. Community DNA was extracted from sampled soils and characterized by use of denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism. DNA bands of interest from Bacteria and Archaea DGGE gels were cloned and sequenced. In cluster analyses of the DNA fingerprints, microbial communities from the anthrosols grouped together regardless of current land use or soil type and were distinct from those in their respective, paired adjacent soils. For the Archaea, the anthrosol communities diverged from the adjacent soils by over 90%. A greater overall richness was observed for Bacteria sequences as compared with those of the Archaea. Most of the sequences obtained were novel and matched those in databases at less than 98% similarity. Several sequences obtained only from the anthrosols grouped at 93% similarity with the Verrucomicrobia, a genus commonly found in rice paddies in the tropics. Sequences closely related to Proteobacteria and Cyanobacteria sp. were recovered only from adjacent soil samples. Sequences related to Pseudomonas, Acidobacteria, and Flexibacter sp. were recovered from both anthrosols and adjacent soils. The strong similarities among the microbial communities present in the anthrosols for both the Bacteria and Archaea suggests that the microbial community composition in these soils is controlled more strongly by their historical soil management than by soil type or current land use. The anthrosols had consistently higher concentrations of incompletely combusted organic black carbon material (BC), higher soil pH, and higher concentrations of P and Ca compared to their respective adjacent soils. Such characteristics may help to explain the longevity and distinctiveness of the anthrosols in the Amazonian landscape and guide us in recreating soils with sustained high fertility in otherwise nutrient-poor soils in modern times.

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Altered matrix metalloproteinases (MMPs) levels are involved in cardiovascular diseases and increased MMP-9 levels enhance the cardiovascular risk in apparently healthy subjects. We investigated the effects of MMP-9 gene polymorphisms and haplotypes on the circulating MMP-9 levels in healthy black subjects and the effects of an MMP-2 polymorphism on the plasma MMP-2 concentrations. We studied 190 healthy subjects, nonsmokers, self-reported as blacks (18-63 years). Genotypes for the MMP-2 C-1306T polymorphism and the MMP-9 C-1562T, 90(CA)(14-24) and Q279R polymorphisms (rs243865, rs3918242, rs2234681, and rs17576, respectively) were determined by TaqMan (R) Allele Discrimination assay and real-time polymerase chain reaction or restriction fragment length polymorphism. Alleles for the 90(CA)(14-24) polymorphism were grouped as low (L) when there were < 21 and high (H) when there were >= 21 CA repeats. The plasma levels of MMP-2 and MMP-9 were determined by gelatin zymography. The software PHASE 2.1 was used to estimate the haplotypes frequencies. Although we found no effects of the MMP-9 C-1562T or the Q279R polymorphisms on MMP-9 levels, higher MMP-9 levels were associated with the HH genotype for the -90(CA)(14-24) polymorphism compared with the HL or LL genotypes. Lower MMP-9 levels were found in carriers of the CRL haplotype (combining the C, R, and L alleles for the MMP-9 polymorphisms) compared with the CRH haplotype. Consistent with this finding, the CRL haplotype was more commonly found in subjects with low MMP-9 levels. The MMP-2 C-1306T polymorphism had no effects on the plasma MMP-2 levels. Our results show that MMP-9 genetic variations modify MMP-9 levels in black subjects and may offer biochemical evidence implicating MMP-9 in the pathogenesis of cardiovascular diseases in blacks.

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Immune thrombocytopenic purpura (ITP) is a common hematological disorder in the childhood, and it is one of the most common forms of autoimmune disease in pediatric patients. The ITP basis is a primary dysfunction of the immune system. This study aimed to analyze the genetic polymorphisms of the Fc gamma receptors IIA and IIIA. The genetic polymorphisms of the Fc receptors gamma IIA (131H/R) and gamma RIIIA (158V/F) were analyzed by polymerase chain reaction-restriction fragment length polymorphism technique. Odds ratio and 95% confidence interval were calculated by chi(2) test. Homozygous polymorphic genotype for the Fc gamma RIIIA was significantly more frequent among patients compared with controls (odds ratio = 0.27; 95% confidence interval, 0.09-0.80; P = 0.03). There was no statistical difference between the ITP group and the controls in the analysis of combinations of alleles of the high-affinity Fc receptor, but the ITP individuals with this combination had a lower duration of disease (P = 0.01). Genetic polymorphisms in immune system genes can be important for ITP pathogenesis and disease outcome.

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The first autochthonous case of American cutaneous leishmaniasis was reported in the Federal District in 1980, and the species involved in this type of leishmaniasis was unknown. This study aimed to identify the species that causes the disease in the Federal District and to investigate its clinical and epidemiological aspects. Between 2000 and 2007, 71 autochthonous cases of leishmaniasis were reported in the Federal District. Leishmania species were identified by means of direct immunofluorescence reactions using monoclonal antibodies and restriction fragment length polymorphism. The species of 40 (56.33%) out of 71 samples were identified. Thirty-six (90%) were identified as Leishmania (Viannia) braziliensis and four (10%) were identified as Leishmania (Leishmania) amazonensis. In this area, the disease had clinical and epidemiological characteristics similar to those found in other Brazilian regions.

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Hypertension is the most common medical disorder in pregnancy, and a leading cause of maternal and neonatal morbidity and mortality. Vitamin D endocrine system has important influence on immune modulation and endothelial function, which play a role in preeclampsia (PE) and gestational hypertension (GH). Vitamin D receptor (VDR) is present in a large variety of cell types, including placental cells. We examined whether there is an association between VDR polymorphisms (FokI, ApaI and BsmI) with PE or with GH. Restriction fragment length polymorphism techniques were used to genotype 529 pregnant (154 with GH, 162 with PE, and 213 healthy pregnant-HP). VDR haplotype frequencies were inferred using the PHASE 2.1 program. We found similar genotype distributions for the three VDR polymorphisms in both PE and GH groups compared with the HP group (all P > 0.05). In parallel with these findings, the VDR haplotype frequency distribution was similar in both PE and GH groups compared with the HP group (all P > 0.05). Our results showing no significant association between VDR polymorphisms or haplotypes with PE or GH suggest that genetic variations in VDR do not predispose to hypertensive disorders of pregnancy.

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OBJECTIVE: Endostatin is a potent endogenous inhibitor of angiogenesis. It is derived from the proteolytic cleavage of collagen XVIII, which is encoded by the COL18A1 gene. A polymorphic COL18A1 allele encoding the functional polymorphism p.D104N impairs the activity of endostatin, resulting in a decreased ability to inhibit angiogenesis. This polymorphism has been previously analyzed in many types of cancer and has been considered a phenotype modulator in some benign and malignant tumors. However, these data are controversial, and different results have been reported for the same tumor types, such as prostate and breast cancer. The purpose of this study was to genotype the p.D104N variant in a cohort of pediatric and adult patients with adrenocortical tumors and to determine its possible association with the biological behavior of adrenocortical tumors. METHODS: DNA samples were obtained from 38 pediatric and 56 adult patients (0.6-75 yrs) with adrenocortical tumors. The DNA samples were obtained from peripheral blood, frozen tissue or paraffin-embedded tumor blocks when blood samples or fresh frozen tissue samples were unavailable. Restriction fragment length polymorphism analysis was used to genotype the patients and 150 controls. The potential associations of the p.D104N polymorphism with clinical and histopathological features and oncologic outcome (age of onset, tumor size, malignant tumor behavior, and clinical syndrome) were analyzed. RESULTS: Both the patient group and the control group were in Hardy-Weinberg equilibrium. The frequencies of the p.D104N polymorphism in the patient group were 81.9% (DD), 15.9% (DN) and 2.2% (NN). In the controls, these frequencies were 80.6%, 17.3% and 2.0%, respectively. We did not observe any association of this variant with clinical or histopathological features or oncologic outcome in our cohort of pediatric and adult patients with adrenocortical tumors.

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Chronic alcohol consumption is associated with an increased risk for upper aerodigestive tract cancer and hepatocellular carcinoma. Increased acetaldehyde production via alcohol dehydrogenase (ADH) has been implicated in the pathogenesis. The allele ADH1C*1 of ADH1C encodes for an enzyme with a high capacity to generate acetaldehyde. So far, the association between the ADH1C*1 allele and alcohol-related cancers among heavy drinkers is controversial. ADH1C genotypes were determined by polymerase chain reaction and restriction fragment length polymorphism in a total of 818 patients with alcohol-associated esophageal (n=123), head and neck (n=84) and hepatocellular cancer (n=86) as well as in patients with alcoholic pancreatitis (n=117), alcoholic liver cirrhosis (n=217), combined liver cirrhosis and pancreatitis (n=17) and in alcoholics without gastrointestinal organ damage (n=174). The ADH1C*1 allele and genotype ADH1C*1/1 were significantly more frequent in patients with alcohol-related cancers than that in individuals with nonmalignant alcohol-related organ damage. Using multivariate analysis, ADH1C*1 allele frequency and rate of homozygosity were significantly associated with an increased risk for alcohol-related cancers (p<0.001 in all instances). The odds ratio for genotype ADH1C*1/1 regarding the development of esophageal, hepatocellular and head and neck cancer were 2.93 (CI, 1.84-4.67), 3.56 (CI, 1.33-9.53) and 2.2 (CI, 1.11-4.36), respectively. The data identify genotype ADH1C*1/1 as an independent risk factor for the development of alcohol-associated tumors among heavy drinkers, indicating a genetic predisposition of individuals carrying this genotype.

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In Switzerland, a national database with 1028 Campylobacter isolates from poultry, pigs, cats, dogs, cattle, humans, zoo animals and water has been created. The database contains the genetic fingerprint and background information of each Campylobacter isolate. Dominant species could be identified in the different sources with a majority of Campylobacter jejuni in poultry (73%), humans (79%), cattle (95%), zoo animals (40%) and water (100%), of Campylobacter coli in pigs (72%), and of Campylobacter upsaliensis/helveticus in cats and dogs (55%). The comparison of three genotyping methods, amplified fragment length polymorphism (AFLP), pulsed field gel electrophoresis and restriction fragment length polymorphism, revealed that AFLP allows discrimination between the different Campylobacter species and is the most appropriate method to distinguish specific strains within the same species. Genotyping analysis demonstrated that the Campylobacter population is heterogeneous among the different sources and that no dominant clone is spread in the country. Genotyping and the resulting database are useful tools to trace back future Campylobacter infections.

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Chronic alcohol consumption is a major risk factor for the development of chronic pancreatitis. However, chronic pancreatitis occurs only in a minority of heavy drinkers. This variability may be due to yet unidentified genetic factors. Several enzymes involved in the degradation of reactive oxidants and xenobiotics, such as glutathione-S-transferase P1 (GSTP1) and manganese-superoxide dismutase (MnSOD) reveal functional polymorphisms that affect the antioxidative capacity and may therefore modulate the development of chronic pancreatitis and long-term complications like endocrine and exocrine pancreatic insufficiency. Two functional polymorphisms of the MnSOD and the GSTP1 gene were assessed by polymerase chain reaction and restriction fragment length polymorphism in 165 patients with chronic alcoholic pancreatitis, 140 alcoholics without evidence of pancreatic disease and 160 healthy control subjects. The distribution of GSTP1 and MnSOD genotypes were in Hardy-Weinberg equilibrium in the total cohort. Genotype and allele frequencies for both genes were not statistically different between the three groups. Although genotype MnSOD Ala/Val was seemingly associated with the presence of exocrine pancreatic insufficiency, this subgroup was too small and the association statistically underpowered. None of the tested genotypes affected the development of endocrine pancreatic insufficiency. Polymorphisms of MnSOD and GSTP1 are not associated with chronic alcoholic pancreatitis. The present data emphasize the need for stringently designed candidate gene association studies with well-characterized cases and controls and sufficient statistical power to exclude chance observations.