171 resultados para Amplified fragment length polymorphism (AFLP)
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Social wasp diversity in Semideciduous Seasonal Forests of the northeast of Sao Paulo State is poorly known, causing a lack of information on the diversity of these wasps from these areas which have been degraded. The objective of this work was to evaluate the social wasp (Vespidae, Polistinae) diversity in a Semideciduous Seasonal Forest of the northeast of Sao Paulo State and to compare three different kinds of sampling methodology. Surveys were conducted from August 2005 to September 2006 in the interior, edge and matrix of a Semideciduous Seasonal Forest fragment in Patrocinio Paulista city, Sao Paulo State. Three methodologies were used: 1. Active collection in flowers, 2. Searching for nests, 3. Active collection with attractive liquid. Thirty species of social wasps were collected in the fragment, but the diversity was highest in the edge. Active collection with attractive liquid was the most efficient methodology. Despite the high levels of deforestation, forest fragments in Sao Paulo State have a high diversity of social wasps, reinforcing the importance of their preservation.
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Precis Women with recurrent vulvovaginal candidiasis (RVC) due to a polymorphism in codon 54 of the MBL2 gene respond better to fluconazole maintenance therapy than do women with other underlying causes. Objective To explain differences in response rates to maintenance therapy with fluconazole in women suffering from RVC by evaluating associations with a polymorphism in the gene coding for mannose-binding lectin (MBL). Design Follow-up study, neted case-control group. Setting Women attending vulvoginitis clinic for RVC. Population Women participating in a multicentric study in Belgium with a degressive dose of fluconazole for RVC (the ReCiDiF trial) were divided into good responders, intermediate responders and nonresponders according to the number of relapses they experienced during therapy. From 109 of these women with adequate follow-up data, vaginal lavage with 2 ml of saline were performed at the moment of a proven acute attack at inclusion in the study, before maintenance treatment was started. A buccal swab was obtained from 55 age-matched women without a history of Candida infections, serving as a control group. Methods Extracted DNA from buccal or vaginal cells was tested for codon 54 MBL2 gene polymorphism by polymerase chain reaction and endonuclease digestion. Main outcome measures Frequency of MBL2 condon 54 allele B in women with optimal or poor response to maintenance therapy in composition with controls. Results Women (n = 109) suffering from RVC were more likely to carry the variant MBL2 codon 54 allele B than control women (20 versus 6.6%, OR 3.4 [95% CI 1.3-8.2], P = 0.01). B alleles were present in 25% of the 36 women not suffering from any recurrence during the maintenance therapy with decreasing doses of fluconazole (OR 4.9 [95% CI 1.9-12.5], P = 0.0007 versus controls), in 20% of the 43 women with sporadic recurrences (OR 3.6 [95% CI 1.4-9.2], P = 0.007 versus controls) and in 15% of the 30 women who had to interrupt the treatment regimen due to frequent relapses (P = 0.097 versus controls). Conclusions The MBL2 codon 54 gene polymorphism is more frequent in Belgian women suffering from RVC than in controls. The presence of the B allele is associated with a superior response to fluconazole maintenance therapy as compared with RVC patients without this polymorphism. We conclude that RVC due to deficient MBL production is more easily helped with antifungal medication than is RVC due to some other mechanism.
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Hepatitis C virus (HCV) is a major cause of hepatic disease and of liver transplantation worldwide. Mannan-binding lectin (MBL), encoded by the MBL2 gene, can have an important role as an opsonin and complement activating molecule in HCV persistence and liver injury. We assessed the MBL2 polymorphism in 102 Euro-Brazilian patients with moderate and severe chronic hepatitis C, paired for gender and age with 102 HCV seronegative healthy individuals. Six common single nucleotide polymorphisms in the MBL2 gene, three in the promoter (H/L, X/Y and P/Q) and three in exon 1 (A, the wild-type, and B, C or D also known as O) were evaluated using real-time polymerase chain reaction with fluorescent hybridization probes. The concentration of MBL in plasma was measured by enzyme-linked immunosorbent assay. The frequency of the YA/YO genotype was significantly higher in the HCV patients compared with the controls (P = 0.022). On the other hand, the genotypes associated with low levels of MBL (XA/XA, XA/YO and YO/YO) were decreased significantly in the patients with severe fibrosis (stage F4), when compared with the patients with moderate fibrosis (stage F2) (P = 0.04) and to the control group (P = 0.011). Furthermore, MBL2 genotypes containing X or O mutations were found to be associated with non-responsiveness to pginterferon and ribavirin treatment (P = 0.023). MBL2 polymorphisms may therefore be associated not only with the development of chronic hepatitis C, but also with its clinical evolution and response to treatment.
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Background Women with 21-hydroxylase deficiency present much variability in external genitalia virilization, even among those with similar impairments of 21-hydroxylase (21OH) activity. Objective To evaluate if the number of CAG (nCAG) repeats of the androgen receptor gene influences the degree of external genitalia virilization in women with CYP21A2 mutations, grouped according to impairment of 21OH activity. Patients The nCAG was determined in 106 congenital adrenal hyperplasia (CAH) patients and in 302 controls. The patients were divided, according to their CYP21A2 genotypes, into Groups A and B, which confer total and severe impairment of 21OH activity, respectively. Methods The inactivation pattern of the X-chromosome was studied through genomic DNA digestion with Hpa II. The CAG repeat region was amplified by polymerase chain reaction (PCR) and analysed by GeneScan. Results The nCAG and the frequency of severe skewed X-inactivation did not differ between normal women and patients. The nCAG median in genotype A was 20.7 (IQR 2.3) for Prader I + II, 22.5 (3.6) for Prader III and 21 (2.9) for Prader IV + V (P < 0.05 for Prader III and Prader IV + V). The nCAG median in genotype B was 21.3 (1.1) for Prader I + II, 20.5 (2.9) for Prader III and 22 (2.8) for Prader IV + V (P > 0.05). A significant difference was found regarding the nCAG median in patients presenting Prader III from genotypes A and B. Conclusions We observed great variability in the degree of external genitalia virilization in both CYP21A2 genotypes, and we showed that the CAG repeats of the androgen receptor gene influences this phenotypic variability.
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Background: The potential involvement of SRY in abnormal gonadal development in 45,X/46,X,der(Y) patients was proposed following the identification of SRY mutations in a few patients with Turner syndrome (TS). However, its exact etiological role in gonadal dysgenesis in patients with Y chromosome mosaicisms has not yet been clarified. Aims: It was the aim of this study to screen for allelic variation in SRY in a large cohort of patients with disorders of sex development due to chromosomal abnormalities with 45, X/46, X, der(Y) karyotype. Patients: Twenty-seven patients, 14 with TS and 13 with mixed gonadal dysgenesis (MGD), harboring 45, X/46, X, der(Y) karyotypes were selected. Methods: Genomic DNA was extracted from peripheral blood leukocytes of all patients and from gonadal tissue in 4 cases. The SRY coding region was PCR amplified and sequenced. Results: We identified only 1 polymorphism (c.561C -> T) in a 45,X/46,XY MGD patient, which was detected in blood and in gonadal tissue. Conclusion: Our results indicate that mutations in SRY are rare findings in patients with Y chromosome mosaicisms. Therefore, a significant role of mutated SRY in the etiology of gonadal dysgenesis in patients harboring 45, X/46, XY karyotype and variants seems very unlikely. Copyright (C) 2010 S. Karger AG, Basel
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Context: Although numerous reports of mutations in GH1 and GHRHR (GHRH receptor) causing isolated GH deficiency (IGHD) have been published, mutations in GHRH itself have not been hitherto reported but are obvious candidates for GH deficiency. Objective: The aim of this study was to identify mutations in GHRH in a large cohort of patients with IGHD. Patients and Methods: DNA was isolated from 151 patients diagnosed with IGHD at national and international centers. Seventy-two patients fulfilled all the following criteria: severe short stature (height SD score <= -2.5), low peakGHafter stimulation (peak <= 5 ng/ml), eutopic posterior pituitary lobe, and absence of mutations in GH1 and GHRHR and therefore were strong candidates for GHRH mutations. The coding sequence and splice sites of GHRH were amplified by PCR with intronic primers and sequenced. Results: In five of 151 patients (four of 42 from Brazil), the GHRH c. 223 C>T, p. L75F change was identified in heterozygosity. This variant has been previously reported as a polymorphism and is more frequent in African than European and Asian populations. Six allelic variants (five novel) that do not predict change of amino acids or splice sites were identified in five patients: c. 147 C>T, p.S49S, IVS1 -70 G>A, IVS1 -74 T>C, IVS3 -47 del1, and IVS3 +7 G>A/IVS3 + 41 G>A. No functional mutations were found in this cohort. Conclusions: GHRH mutations were not identified in a selected cohort of patients with IGHD, suggesting that, if they exist, they may be an extremely rare cause of IGHD. Other, as-yet-unidentified genetic factors may be implicated in the genetic etiology of IGHD in our cohort. (J Clin Endocrinol Metab 96: E1457-E1460, 2011)
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Adjuvant cisplatin-based chemoradiation improves survival in HNSCC patients presenting with risk features. ERCC1 (excision repair cross-complementation group 1) is associated with resistance to chemo- and radiation therapy and may have a prognostic value in HNSCC patients. Here we studied ERCC1 expression and the polymorphism T19007C as prognostic markers in these patients. This is a retrospective and translational analysis, where ERCC1 protein expression was evaluated by immunohistochemistry, using an H-score, and mRNA expression was determined by RT-PCR. T 19007C genotypes were detected by PCR-RFLP carried out using DNA template extracted from normal lymph nodes. A high H-score was seen in 32 patients (54%), who presented better 5-year overall survival (5-y OS: 50% vs. 18%, HR 0.43, p=0.026). Fifteen out of 45 patients (33%), with high mRNA expression, presented better 5-year overall survival (OS) (86% vs. 30%, HR 0.26, p=0.052). No OS difference was detected among T 19007C genotypes. High H-score and mRNA expression remained significant as favorable prognostic factors in a multivariate analysis. Collectively, our results suggest that high ERCC1 expression seems to be associated with better OS rates in HNSCC patients submitted to adjuvant cisplatin-based chemoradiation.
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Mucosal leishmaniasis (ML) follows localized cutaneous leishmaniasis (CL) caused by Leishmania braziliensis. Proinflammatory responses mediate CL self-healing but are exaggerated in ML Proinflammatory monocyte chemoattractant protein 1 (MCP-1; encoded by CCL2) is associated with CL We explore its role in CL/ML through analysis of the regulatory CCL2 -2518 bp promoter polymorphism in CL/ML population samples and families from Brazil. Genotype frequencies were compared among ML/CL cases and control groups using logistic regression and the family-based association test (FBAT). MCP-1 was measured in plasma and macrophages. The GG recessive genotype at CCL2 -2518 bp was more common in patients with ML (N = 67) than in neighborhood control (NC; N = 60) subjects (OR 1.78; 95% Cl 1.01-3.14; P = 0.045), than in NC combined with leishmanin skin-test positive (N = 60) controls (OR 4.40; 95% CI 1.42-13.65; P = 0.010), and than in controls combined with CL (N = 60) patients (OR 2.78; 95% CI 1.13-6.85; P = 0.045). No associations were observed for CL compared to any groups. FBAT (91 ML and 223 CL cases in families) confirmed recessive association of ML with allele G (Z = 2.679; P = 0.007). Higher levels of MCP-1 occurred in plasma (P = 0.03) and macrophages (P < 0.0001) from GG compared to AA individuals. These results suggest that high MCP-1 increases risk of ML (C) 2010 Elsevier B.V. All rights reserved.
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Objective. To evaluate whether the A/G polymorphism at position 2518 in the regulatory region of the monocyte chemoattractant protein-1 (MCP-1) or the V/I polymorphism at position 64 of the receptor. CCR2, are associated with lupus nephritis (LN) or any clinical characteristics of the disease or with renal survival in a patient population. Methods. We selected 197 patients with lupus nephritis and 220 matched healthy controls for study. MCP-1 and CCR2 genotyping was performed by polymerase chain reaction. Clinical and laboratory data were compiled from patients` charts over followup that ranged from 6 months to 10 years. Results. The GIG genotype of MCP-1 was more common in LN patients (p = 0.019), while the A allele was associated with healthy controls (p = 0.007) as was the V allele of CCR2 (p = 0.046) compared to LN patients. Clinical index measures [SLE Disease Activity Index (SLEDAI)], immunological markers, renal histology, renal function at enrollment, and renal survival were not influenced by these polymorphisms. A less aggressive renal disease, measured by renal SLEDAI index, was associated with the V allele of the CCR2 gene polymorphism. Conclusion. These findings support that MCP-1 2518 GIG is associated with LN but there was no association of this genotype with renal function or renal survival. When studying CCR2 64 V/I polymorphism we showed a positive association of the V allele with healthy controls but no association of the genotype with LN patients. (First Release March 152010; J Rheumatol 2010;37:776-82; doi:10.3899/jrheum.090681)
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Background: Forearm blood flow responses during mental stress are greater in individuals homozygous for the Glu27 allele. A high-fat meal is associated with impaired endothelium-dependent dilatation. We investigated the impact of high-fat ingestion on the muscle vasodilatory responses during mental stress in individuals with the Glu27 allele and those with the Gln27 allele of the beta(2)-adrenoceptor gene. Methods: A total of 162 preselected individuals were genotyped for the Glu27Gln beta(2)-adrenoceptor polymorphism. Twenty-four individuals participated in the study. Fourteen were homozygous for the Gln27 allele (Gln27Gln, 40 +/- 2 years; 64 +/- 2 kg), and 10 were homozygous for the Glu27 allele (Glu27Glu, 40 +/- 3 years; 65 +/- 3 kg). Forearm blood flow was evaluated by venous occlusion plethysmography before and after ingestion of 62 g of fat. Results: The high-fat meal caused no changes in baseline forearm vascular conductance (FVC, 2.2 +/- 0.1 vs. 2.4 +/- 0.2; P = 0.27, respectively), but reduced FVC responses to mental stress (1.5 +/- 0.2 vs. 0.8 +/- 0.2 units; P = 0.04). When volunteers were divided according to their genotypes, baseline FVC was not different between groups (Glu27Glu = 2.4 +/- 0.1 vs. Gln27Gln = 2.1 +/- 0.1 units; P = 0.08), but it was significantly greater in Glu27Glu individuals during mental stress (1.9 +/- 0.4 vs. 1.0 +/- 0.3 units; P = 0.04). High-fat intake eliminated the difference in FVC responses between Glu27Glu and Gln27Gln individuals (FVC, 1.3 +/- 0.4 vs. 1.2 +/- 0.4; P = 0.66, respectively). Conclusion: These findings demonstrate that a high-fat meal impairs muscle vasodilatation responses to mental stress in humans. However, this reduction can be attributed to the presence of the homozygous Glu27 allele of the beta(2)-adrenoceptor gene.
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Background: The angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism gene contributes to the genesis of hypertension (HTN) and may help explain the relationship between obstructive sleep apnea (OSA) and HTN. However, ACE is a pleiotropic gene that has several influences, including skeletal muscle and control of ventilation. We therefore tested the hypothesis that ACE polymorphism influences OSA severity. Methods: Male OSA patients (apnea-hypopnea index [AHI] > 5 events/h) from 2 university sleep centers were evaluated by polysomnography and ACE I/D polymorphism genotyping. Results: We studied 266 males with OSA (age = 48 +/- 13y, body mass index = 29 5kg/m(2), AHI = 34 +/- 25events/h). HTN was present in 114 patients (43%) who were older (p < 0.01), heavier (p < 0.05) and had more severe OSA (p < 0.01). The I allele was associated with HTN in patients with mild to moderate OSA (p < 0.01), but not in those with severe OSA. ACE I/D polymorphism was not associated with apnea severity among normotensive patients. In contrast. the only variables independently associated with OSA severity among patients with hypertension in multivariate analysis were BMI (OR = 1.12) and 11 genotype (OR = 0.27). Conclusions: Our results indicate reciprocal interactions between OSA and HTN with ACE I/D polymorphism, suggesting that among hypertensive OSA males, the homozygous ACE I allele protects from severe OSA. (C) 2009 Elsevier B.V. All rights reserved.
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The contribution of kinins to the beneficial effects in cardiovascular risk reductions remains unclear. In this context, the present study examined whether the +9bp/-9 bp polymorphism in bradykinin type 2 receptor gene, predicts hypertension risk in a large urban Brazilian population. Our finding indicated that the -9 bp allele may contribute to hypertension because of increased diastolic pressure.
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Dias RG, Alves MJ, Pereira AC, Rondon MU, dos Santos MR, Krieger JE, Krieger MH, Negrao CE. Glu298Asp eNOS gene polymorphism causes attenuation in nonexercising muscle vasodilatation. Physiol Genomics 37: 99-107, 2009. First published January 21, 2009; doi:10.1152/physiolgenomics.90368.2008.-The influence of Glu298Asp endothelial nitric oxide synthase (eNOS) polymorphism in exercise-induced reflex muscle vasodilatation is unknown. We hypothesized that nonexercising forearm blood flow (FBF) responses during handgrip isometric exercise would be attenuated in individuals carrying the Asp298 allele. In addition, these responses would be mediated by reduced eNOS function and NO-mediated vasodilatation or sympathetic vasoconstriction. From 287 volunteers previously genotyped, we selected 33 healthy individuals to represent three genotypes: Glu/Glu [n = 15, age 43 +/- 3 yr, body mass index (BMI) 22.9 +/- 0.3 kg/m(2)], Glu/Asp (n = 9, age 41 +/- 3 yr, BMI 23.7 +/- 1.0 kg/m(2)), and Asp/Asp (n = 9, age 40 +/- 4 yr, BMI 23.5 +/- 0.9 kg/m(2)). Heart rate (HR), mean blood pressure (MBP), and FBF (plethysmography) were recorded for 3 min at baseline and 3 min during isometric handgrip exercise. Baseline HR, MBP, FBF, and forearm vascular conductance (FVC) were similar among genotypes. FVC responses to exercise were significantly lower in Asp/Asp when compared with Glu/Asp and Glu/Glu (Delta = 0.07 +/- 0.14 vs. 0.64 +/- 0.20 and 0.57 +/- 0.09 units, respectively; P = 0.002). Further studies showed that intra-arterial infusion of N(G)-monomethyl-L-arginine (L-NMMA) did not change FVC responses to exercise in Asp/Asp, but significantly reduced FVC in Glu/Glu (Delta = 0.79 +/- 0.14 vs. 0.14 +/- 0.09 units). Thus the differences between Glu/Glu and Asp/Asp were no longer observed (P = 0.62). L-NMMA + phentolamine increased similarly FVC responses to exercise in Glu/Glu and Asp/Asp (P = 0.43). MBP and muscle sympathetic nerve activity increased significant and similarly throughout experimental protocols in Glu/Glu and Asp/Asp. Individuals who are homozygous for the Asp298 allele of the eNOS enzyme have attenuated nonexercising muscle vasodilatation in response to exercise. This genotype difference is due to reduced eNOS function and NO-mediated vasodilatation, but not sympathetic vasoconstriction.
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Arg72Pro is a common polymorphism in TP53, showing differences in its biological functions. Case-control studies have been performed to elucidate the role of Arg72Pro in cancer, although the results are conflicting and heterogeneous. Here, we analyzed pooled data from case-control studies to determine the role of Arg72Pro in different cancer sites. We performed a systematic review and meta-analysis of 302 case-control studies that analyzed Arg72Pro in cancer susceptibility. Odds ratios were estimated for different tumor sites using distinct genetic models, and the heterogeneity between studies was explored using I(2) values and meta-regression. We adopted quality criteria to classify the studies. Subgroup analyses were done for tumor sites according to ethnicity, histological, and anatomical sites. Results indicated that Arg72Pro is associated with higher susceptibility to cancer in some tumor sites, mainly hepatocarcinoma. For some tumor sites, quality of studies was associated with the size of genetic association, mainly in cervical, head and neck, gastric, and lung cancer. However, study quality did not explain the observed heterogeneity substantially. Meta-regression showed that ethnicity, allelic frequency and genotyping method were responsible for a substantial part of the heterogeneity observed. Our results suggest ethnicity and histological and anatomical sites may modulate the penetrance of Arg72Pro in cancer susceptibility. This meta-analysis denotes the importance for more studies with good quality and that the covariates responsible for heterogeneity should be controlled to obtain a more conclusive response about the function of Arg72Pro in cancer.
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Background Basal cell carcinomas (BCCs) are the most frequent human cancer that results from malignant transformation of basal cells in the epidermis. Gorlin syndrome is a rare inherited autosomal dominant disease that predisposes with multiple BCCs and other birth defects. Both sporadic and inherited BCCs are associated with mutations in the tumor suppressor gene PTCH1, but there is still uncertainty on the role of its homolog PTCH2. Objectives To search for mutations and genomic instability in sporadic and inherited BCCs. Methods DNA obtained from leukocytes and tumor cells was amplified by polymerase chain reaction regarding five exons of PTCH1 and PTCH2 and neighboring microsatellites. Exons were sequenced and compared with the GenBank database. Results Only D9S180, of six microsatellites, showed loss of heterozygosity in three BCCs (two sporadic and one inherited). One sporadic BCC presented the mutation g. 2885G>C in exon 17 of PTCH1, which predicts the substitution p.R962T in an external domain of the protein. In addition, the leukocytes and tumor cells of one patient with Gorlin syndrome showed the mutation g. 2839T>G in the same exon and gene, which predicts a p.E947stop and truncated protein. All control and tumor samples presented IVS9 + 217T in intron 9 of PTCH1. Conclusion Mutations found in the PTCH1 gene and neighboring repetitive sequences may have contributed to the development of the studied BCCs.