267 resultados para structure factor


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Adult rats submitted to perinatal salt overload presented renin-angiotensin system (RAS) functional disturbances. The RAS contributes to the renal development and renal damage in a 5/6 nephrectomy model. The aim of the present study was to analyze the renal structure and function of offspring from dams that received a high-salt intake during pregnancy and lactation. We also evaluated the influence of the prenatal high-salt intake on the evolution of 5/6 nephrectomy in adult rats. A total of 111 sixty-day-old rat pups from dams that received saline or water during pregnancy and lactation were submitted to 5/6 nephrectomy (nephrectomized) or to a sham operation (sham). The animals were killed 120 days after surgery, and the kidneys were removed for immunohistochemical and histological analysis. Systolic blood pressure (SBP), albuminuria, and glomerular filtration rate (GFR) were evaluated. Increased SBP, albuminuria, and decreased GFR were observed in the rats from dams submitted to high-sodium intake before surgery. However, there was no difference in these parameters between the groups after the 5/6 nephrectomy. The scores for tubulointerstitial lesions and glomerulosclerosis were higher in the rats from the sham saline group compared to the same age control rats, but there was no difference in the histological findings between the groups of nephrectomized rats. In conclusion, our data showed that the high-salt intake during pregnancy and lactation in rats leads to structural changes in the kidney of adult offspring. However, the progression of the renal lesions after 5/6 nephrectomy was similar in both groups.

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Epidermal growth factor (EGF) plays an important role in cancer. A functional single nucleotide polymorphism (SNP) in the 5`-untranslated region of the EGF gene (+61 A>G) may influence its expression and contribute to cancer predisposition and aggressiveness. Aiming to investigate the role of EGF +61 A>G in the susceptibility to glioma and its prognosis, we performed a case-control study with 165 patients and 200 healthy controls from Brazil. Comparisons of genotype distributions and allele frequencies did not reveal any significant differences between the groups. The mean overall survival was 9.2 months for A/A, 8.2 months for A/G, and 7.7 months for GIG. When survival curves were plotted we found that the +61G allele is associated with poor overall survival (p=0.023) but not with disease-free survival (p=0.527). Our data suggest that, although there is no association between the EGF +61 A>G genotype and glioma susceptibility, this SNP is associated with shorter overall survival of glioma patients in the Brazilian population. Nevertheless, future studies utilizing a larger series are essential for a definitive conclusion. (Int J Biol Markers 2009; 24: 277-81)

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Objective: Cannabidiol is a chemical constituent from Cannabis sativa and it has multiple mechanisms of action, including antidepressant effects. The main objective of the present study was to evaluate behavioural and molecular effects induced by administration of cannabidiol and imipramine in rats. Methods: In the present study, rats were acutely or chronically treated for 14 days once a day with saline, cannabidiol (15, 30 and 60 mg/kg) or imipramine (30 mg/kg) and the animals behaviour was assessed in forced swimming and open-field tests. Afterwards, the prefrontal cortex, hippocampus and amygdala brain-derived neurotrophic factor (BDNF) levels were assessed by enzyme-linked immunosorbent sandwich assay. Results: We observed that both acute and chronic treatments with imipramine at the dose of 30 mg/kg and cannabidiol at the dose of 30 mg/kg reduced immobility time and increased swimming time; climbing time was increased only with imipramine at the dose of 30 mg/kg, without affecting locomotor activity. In addition, chronic treatment with cannabidiol at the dose of 15 mg/kg and imipramine at the dose of 30 mg/kg increased BDNF levels in the rat amygdala. Conclusion: In conclusion, our results indicate that cannabidiol has an antidepressant-like profile and could be a new pharmacological target for the treatment of major depression.

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This study examined the psychometric properties of the Brazilian versions of the Fagerstrom Test for Nicotine Dependence (FTND) and the Heaviness of Smoking Index (HSI). The test-retest reliability of the FTND was assessed in a sample of 61 smoking university students, with a 15-day interval between assessments. The interrater reliability was examined in 30 smoking patients of a psychosocial care center for alcohol and drug users (PCC-AD). The reliability coefficient was estimated by the kappa and intraclass correlation coefficients. The predictive validity, internal consistency, and factor structure of the FTND and the HSI were evaluated by factor analysis in 271 smokers treated at an emergency unit and at the PCC-AD. The gold standard was the nicotine dependence criteria of DSM-IV, as assessed by the Structured Clinical Interview for DSM-IV. The FTND showed high reliability, with correlation coefficients of .92 for test-retest reliability and .99 for interrater reliability. Both the FTND and the HSI presented high levels of sensitivity and specificity. The internal consistency evaluation yielded a Cronbach`s alpha coefficient of .83 for the FTND and of .56 for the HSI. An exploratory factor analysis found 2 factors in the FTND, which were validated by a confirmatory factor analysis. The results obtained in this study confirm the validity and reliability of the Brazilian versions of the FTND and the HSI.

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To investigate the relationship between NF-kappa B activation and hepatic stellate cell (HSC) apoptosis in hepatosplenic schistosomiasis, hepatic biopsies from patients with Schistosoma mansoni-induced periportal fibrosis, hepatitis C virus-induced cirrhosis, and normal liver were submitted to alpha-smooth muscle actin (alpha-SMA) and NF-kappa B p65 immunohistochemistry, as well as to NF-kappa B Southwestern histochemistry and TUNEL assay. The numbers of alpha-SMA-positive cells and NF-kappa B- and NF-kappa B p65-positive HSC nuclei were reduced in schistosomal fibrosis relative to liver cirrhosis. In addition, increased HSC NF-kappa B p65 and TUNEL labeling was observed in schistosomiasis when compared to cirrhosis. These results suggest a possible relationship between the slight activation of the NF-kappa B complex and the increase of apoptotic HSC number in schistosome-induced fibrosis, taking place to a reduced HSC number in schistosomiasis in relation to liver cirrhosis. Therefore, the NF-kappa B pathway may constitute an important down-regulatory mechanism in the pathogenesis of human schistosomiasis mansoni, although further studies are needed to refine the understanding of this process. (C) 2009 Elsevier B.V. All rights reserved.

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Background Porphyria cutanea tarda (PCT) is a metabolic disease characterized by vesicles and blisters in sun-exposed areas and scleroderma-like lesions in sun-exposed and non-sun-exposed areas. Mast cells participate in the pathogenesis of bullous diseases and diseases that show sclerosis, including PCT. Moreover, transforming growth factor-beta (TGF-beta) is the main cytokine in the development of tissue sclerosis. The correlation of mast cells and TGF-beta with the lesions of PCT has not been examined, however. The possible role of mast cells and TGF-beta (and the relationship between them) in the development of PCT lesions is discussed. Methods To quantify mast cells and cells expressing TGF-beta in skin samples from patients with PCT and controls, immunohistochemical studies were performed in tissue sections allied to morphometric analyses. Results The numbers of mast cells and cells expressing TGF-beta per square millimiter were increased in the PCT group relative to controls, and there was a direct and significant correlation between the mast cell number and cells expressing TGF-beta in PCT. Conclusions The results suggest that the increased number of mast cells and of cells expressing TGF-beta, as well as their direct correlation, may contribute to the pathogenesis of the skin lesions in PCT.

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Topoisomerases are ubiquitous nuclear enzymes that regulate DNA structure in eukaryotic cells. The role of topoisomerase III beta, the newest member of the topoisomerase family, in the clinical outcome of breast cancer is still poorly understood. This study aims to investigate the immunoexpression of topoisomerase III beta in breast cancer and its relationships with clinicopathologic features and immunohistochemical markers of prognostic significance in breast pathology. Using tissue microarrays containing 171 cases of primary invasive breast cancer, we analyzed the immunoexpression of topoisomerase III beta, estrogen receptor, progesterone receptor, HER-2, BRCA-1, p53, and Ki67. Immunostaining for topoisomerase III beta was found in 33.9% of breast carcinomas, and immunopositivity was correlated with distant metastasis (P = .036) and death (P = .006). Decreased expression of topoisomerase III beta correlated with low expression of Ki67 (P < .001) and negativity for HER-2 (P < .001), BRCA-1 (P = .001), and p53 (P < .001). In the multivariate analysis, topoisomerase Hip expression was a significant predictor of survival (hazard ratio, 3.006 [95% confidence interval, 1.582-5.715]; P = .001). In conclusion, topoisomerase III beta expression can be a useful marker in assessing the prognosis of patients with breast cancer and is an independent predictor of survival. (C) 2010 Elsevier Inc. All rights reserved.

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Background: Angiogenesis has been shown as an important process in hematological malignancies. It consists in endothelial proliferation, migration, and tube formation following pro-angiogenic factors releasing, specially the vascular endothelial growth factor (VEGF), which angiogenic effect seems to be dependent on nitric oxide (NO). We examined the association among functional polymorphism in these two angiogenesis related genes: VEGF (-2578C>A, -1154G>A, and -634G>C) and NOS3 (-786T>C, intron 4 b>a, and Glu298Asp) with prognosis of childhood acute lymphoblastic leukemia (ALL). Methods: The genotypes were determined and haplotypes estimated in 105 ALL patients that were divided in 2 groups: high risk (HR) and low risk of relapse (LR) patients. In addition, event-free survival curves according to genotypes were assessed. Results: The group HR compared to the LR showed a higher frequency of the alleles -2578C and -634C and the haplotype CGC for VEGF (0.72 vs. 0.51, p<0.008; 0.47 vs. 0.26, p<0.008; and 42.1 vs. 14.5, p<0.006; respectively) and a lower frequency of the haplotype CbGlu (0.4 vs. 8.8, p<0.006), for NOS3. Conclusion: Polymorphisms of VEGF and NOS3 genes are associated with high risk of relapse, therefore may have a prognostic impact in childhood ALL. (C) 2010 Elsevier B.V. All rights reserved.

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The incidence of cerebral edema during therapy of diabetic ketoacidosis (DKA) in children remains unacceptably high-this suggests that current treatment may not be ideal and that important risk factors for the development of cerebral edema have not been recognized. We suggest that there are two major sources for an occult generation of osmole-free water in these patients: first, fluid with a low concentration of electrolytes that was retained in the lumen of the stomach when the patient arrived in hospital; second, infusion of glucose in water at a time when this solution can be converted into water with little glucose. In a retrospective chart review of 30 patients who were admitted with a diagnosis of DKA and a blood sugar > 900 mg/dL (50 mmol/L), there were clues to suggest that some of the retained fluid in the stomach was absorbed. To minimize the likelihood of creating a dangerous degree of cerebral edema in patients with DKA, it is important to define the likely composition of fluid retained in the stomach on admission, to look for signs of absorption of some of this fluid during therapy, and to be especially vigilant once fat-derived brain fuels have disappeared, because this is the time when glucose oxidation in the brain should increase markedly, generating osmole-free water.

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Association between insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD) has been reported. This prompted us to evaluate the power of the insulin sensitivity index (ISI) in association with IGFBP-1 to identify IR early in obese children/adolescents. OGTT was performed in 34 obese/overweight children/adolescents. Glucose, insulin and IGFBP-1 were measured in serum samples and ISI was calculated. Considering the presence of three or more risk factors for IR as a criterion for IR, ISI <4.6 showed 87.5% sensitivity and 94.5% specificity in diagnosing IR. IGFBP-1 was lower in the group with ISI <4.6 (p <0.01). In this group, three patients had higher than expected IGFBP-1, suggesting hepatic IR, while three patients with ISI >4.6 showed very low IGFBP-1 levels. Conclusion: ISI <4.6 is a good indicator of early peripheral IR and, associated with IGFBP-1, can identify increased risk of hepatic IR. Low IGFBP-1 levels among non-IR children may indicate increased portal insulin levels.

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Context: Genetic factors that influence the response to recombinant human GH (rhGH) therapy remain mostly unknown. To date, only the GH receptor gene has been investigated. Objective: The aim of the study was to assess the influence of a polymorphism in the IGF-binding protein-3 (IGFBP-3) promoter region (-202 A/C) on circulating IGFBP-3 levels and growth response to rhGH therapy in children with GH deficiency (GHD). Design and Patients: -202 A/C IGFBP3 genotyping (rs2854744) was correlated with data of 71 children with severe GHD who remained prepubertal during the first year of rhGH treatment. Main Outcome Measures: We measured IGFBP-3 levels and first year growth velocity (GV) during rhGH treatment. Results: Clinical and laboratory data at the start of treatment were indistinguishable among patients with different -202 A/C IGFBP3 genotypes. Despite similar rhGH doses, patients homozygous for the A allele presented higher IGFBP-3 SD score levels and higher mean GV in the first year of rhGH treatment than patients with AC or CC genotypes (first year GV, AA = 13.0 +/- 2.1 cm/yr, AC = 11.4 +/- 2.5 cm/yr, and CC = 10.8 +/- 1.9 cm/yr; P = 0.016). Multiple linear regression analyses demonstrated that the influence of -202 A/C IGFBP3 genotype on IGFBP-3 levels and GV during the first year of rhGH treatment was independent of other variables. Conclusion: The -202 A allele of IGFBP3 promoter region is associated with increased IGFBP-3 levels and GV during rhGH treatment in prepubertal GHD children. (J Clin Endocrinol Metab 94: 588-595, 2009)

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The HLA-G gene is predominantly expressed at the maternal-fetal interface. It has been associated with maternal-fetal tolerance and in the inhibition of cytotoxic T lymphocyte and natural killer cytolytic functions. At least two variations in the 3` untranslated region (UTR) of HLA-G locus are associated with HLA-G expression levels, the 14-bp deletion/insertion polymorphism and the +3142 single-nucleotide polymorphism (SNP). However, this region has not been completely characterized yet. The variability of the 3`UTR of HLA-G gene and its haplotype structure were characterized in 155 individuals from Brazil, as well as HLA-G alleles associated with each of the 3`UTR haplotype. The following eight variation sites were detected: the 14-bp polymorphism and SNPs at the positions +3003T/C, +3010C/G, +3027A/C, +3035C/T, +3142G/C, +3187A/G and +3196C/G. Similarly, 11 different 3`UTR haplotypes were identified and several HLA-G alleles presented only one 3`UTR haplotype. In addition, a high linkage disequilibrium among the variation sites was detected, especially among the 14-bp insertion and the alleles +3142G and +3187A, all previously associated with low mRNA availability, demonstrating that their effects are not independent. The detailed analyses of 3`UTR of the HLA-G locus may shed some light into mechanisms underlying the regulation of HLA-G expression. Genes and Immunity (2010) 11, 134-141; doi: 10.1038/gene.2009.74; published online 1 October 2009

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This study evaluates the mRNA expression profile of genes TIMP1, TIMP2, MMP2 and MMP9 in diagnostic bone marrow samples from 134 consecutive ALL children by real-time quantitative PCR. A significant association was observed between higher expression levels of MMP9 and low risk group and absence of extramedullary infiltration and higher expression levels of TIMP2 and MMP2 with T-ALL. TIMP1 gene expression values higher than the median were associated with a significantly lower 5-year event free-survival in univariable (P = 0.04) and multivariable analysis (P = 0.01). Our data address new information in the complex interaction of the migration/adhesion genes and childhood ALL. (c) 2009 Elsevier Ltd. All rights reserved.

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Brain derived neurotrophic factor (BDNF) has been related to neuroprotection in a series of central nervous system diseases, although its role in multiple sclerosis (MS) was only partially investigated. In this work, we aimed to evaluate the plasma levels of BDNF from 29 MS patients and 24 control subjects. MS patients had decreased levels of BDNF in comparison with healthy controls. BDNF levels increased significantly after MS relapse. Our results provide some evidence for the involvement of BDNF in the pathogenesis of MS and suggest a role for this neurotrophin during the recovery of acute demyelinating inflammatory lesion. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

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Background: The tumor necrosis factor (TNF) gene is located within the highly polymorphic major histocompatibility complex region, exhibiting the -308 CA promoter region polymorphism and six microsatellites (TNFa-f) spanning the region nearby the TNF locus. Objective: In the present Study, we evaluated the frequency of -308 CA and TNFa-e polymorphisms and respective haplotypes (in chromosomal sequence: TNFd-TNFe-308GA-TNFc-TNFa-TNFb), in 222 patients with AIDS, 52 of whom exhibited cytomegalovirus retinitis, and in 202 healthy HIV-negative individuals. Method: TNF microsatellite and single nucleotide polymorphism typings were performed by PCR followed by polyacrylamide gel electrophoresis. Results: The TNF-308A allele and the 4-3-C-2-7-1 haplotype were associated with susceptibility to AIDS, whereas the TNFb4 allele and the 3-3-C-1-11-4 haplotype were associated with protection against AIDS development. The TNFc2 allele and the 4-1-G-2-2-1 haplotype, which contains the TNFc2 allele, were associated with cytomegalovirus retinitis. Conclusion: This study highlights that polymorphic sites spanning the region nearby the TNF locus are associated with AIDS per se and with cytomegalovirus retinitis in AIDS patients. (C) 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins