162 resultados para Perinatal androgen blockade

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)


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Nos últimos 20 anos, houve uma melhoria de praticamente todos os indicadores da saúde materna no Brasil, assim como grande ampliação do acesso aos serviços de saúde. Paradoxalmente, não há qualquer evidência de melhoria na mortalidade materna. Este texto tem como objetivo trazer elementos para a compreensão deste paradoxo, através do exame dos modelos típicos de assistência ao parto, no SUS e no setor privado. Analisaremos as propostas de mudança para uma assistência mais baseada em evidências sobre a segurança destes modelos, sua relação com os direitos das mulheres, e com os conflitos de interesse e resistências à mudança dos modelos. Examinamos os pressupostos de gênero que modulam a assistência e os vieses de gênero na pesquisa neste campo, expressos na superestimação dos benefícios da tecnologia, e na subestimação ou na negação dos desconfortos e efeitos adversos das intervenções. Crenças da cultura sexual não raro são tidas como explicações 'científicas' sobre o corpo, a parturição e a sexualidade, e se refletem na imposição de sofrimentos e riscos desnecessários, nas intervenções danosas à integridade genital, e na negação do direito a acompanhantes. Esta 'pessimização do parto' é instrumental para favorecer, por comparação, o modelo da cesárea de rotina. Por fim, discutimos como o uso da categoria gênero pode contribuir para promover direitos e mudanças institucionais, como no caso dos acompanhantes no parto

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BACKGROUND: Ambient levels of air pollution may affect the health of children, as indicated by studies of infant and perinatal mortality. Scientific evidence has also correlated low birth weight and preterm birth, which are important determinants of perinatal death, with air pollution. However, most of these studies used ambient concentrations measured at monitoring sites, which may not consider differential exposure to pollutants found at elevated concentrations near heavy-traffic roadways. OBJECTIVES: Our goal was to examine the association between traffic-related pollution and perinatal mortality. METHODS: We used the information collected for a case-control study conducted in 14 districts in the City of Sao Paulo, Brazil, regarding risk factors for perinatal deaths. We geocoded the residential addresses of cases (fetal and early neonatal deaths) and controls (children who survived the 28th day of life) and calculated a distance-weighted traffic density (DWTD) measure considering all roads contained in a buffer surrounding these homes. RESULTS: Logistic regression revealed a gradient of increasing risk of early neonatal death with higher exposure to traffic-related air pollution. Mothers exposed to the highest quartile of the DWTD compared with those less exposed exhibited approximately 50% increased risk (adjusted odds ratio = 1.47; 95% confidence interval, 0.67-3.19). Associations for fetal mortality were less consistent. CONCLUSIONS: These results suggest that motor vehicle exhaust exposures may be a risk factor for perinatal mortality.

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The aim of the present study was to examine the impact of polymorphisms in prostate-specific antigen (PSA) and androgen-related genes (AR, CYP17, and CYP19) on prostate cancer (PCa) risk in selected high-risk patients who underwent prostate biopsy. Blood samples and prostate tissues were obtained for DNA analysis. Single-nucleotide polymorphisms in the 50-untranslated regions (UTRs) of the PSA (substitution A > G at position -158) and CYP17 (substitution T > C at 50-UTR) genes were detected by polymerase chain reaction (PCR)-restriction fragment length polymorphism assays. The CAG and TTTA repeats in the AR and CYP19 genes, respectively, were genotyped by PCR-based GeneScan analysis. Patients with the GG genotype of the PSA gene had a higher risk of PCa than those with the AG or AA genotype (OR = 3.79, p = 0.00138). The AA genotype was associated with lower PSA levels (6.44 +/- 1.64 ng/mL) compared with genotypes having at least one G allele (10.44 +/- 10.06 ng/mL) (p = 0.0687, 95% CI - 0.3146 to 8.315, unpaired t-test). The multivariate analysis confirmed the association between PSA levels and PSA genotypes (AA vs. AG+GG; chi(2) = 0.0482) and CYP19 (short alleles homozygous vs. at least one long allele; chi(2) = 0.0110) genotypes. Genetic instability at the AR locus leading to somatic mosaicism was detected in one PCa patient by comparing the length of AR CAG repeats in matched peripheral blood and prostate biopsy cores. Taken together, these findings suggest that the PSA genotype should be a clinically relevant biomarker to predict the PCa risk.

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AIM: To evaluate effects of pre- and postnatal protein deprivation and postnatal recovery on the myenteric plexus of the rat esophagus. METHODS: Three groups of young Wistar rats (aged 42 d) were studied: normal-fed (N42), protein-deprived (D42), and protein-recovered (R42). The myenteric neurons of their esophagi were evaluated by histochemical reactions for nicotinamide adenine dinucleotide (NADH), nitrergic neurons (NADPH)-diaphorase and acetylcholinesterase (AChE), immunohistochemical reaction for vasoactive intestinal polypeptide (VIP), and ultrastructural analysis by transmission electron microscopy. RESULTS: The cytoplasms of large and medium neurons from the N42 and R42 groups were intensely reactive for NADH. Only a few large neurons from the D42 group exhibited this aspect. NADPH detected in the D42 group exhibited low reactivity. The AChE reactivity was diffuse in neurons from the D42 and R42 groups. The density of large and small varicosities detected by immunohistochemical staining of VIP was low in ganglia from the D42 group. In many neurons from the D42 group, the double membrane of the nuclear envelope and the perinuclear cisterna were not detectable. NADH and NADPH histochemistry revealed no group differences in the profile of nerve cell perikarya (ranging from 200 to 400 mu m(2)). CONCLUSION: Protein deprivation causes a delay in neuronal maturation but postnatal recovery can almost completely restore the normal morphology of myenteric neurons. (C) 2010 Baishideng. All rights reserved.

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Aims: The clinical benefits of angiotensin II type 1 (AT1) receptor blockers (ARB) in heart failure (HF) include cardiac anti-remodeling and improved ventricular function. However, the cellular mechanisms underlying the benefits of ARB on ventricular function need to be better clarified. In the present manuscript, we evaluated the effects of AT1 receptor blockade on the net balance of Ca(2+) handling proteins in hearts of mice lacking alpha(2A) and alpha(2C) adrenoceptors (alpha(2A)/alpha(2C)ARKO), which develop sympathetic hyperactivity (SH) induced-HF. Main methods: A cohort of male wild-type (WT) and congenic alpha(2A)/alpha(2C)ARKO mice in a C57BL6/J genetic background (5-7 mo of age) was randomly assigned to receive either placebo or ARB (Losartan, 10 mg/kg for 8wks). Ventricular function (VF) was assessed by echocardiography, and cardiac myocyte width and ventricular fibrosis by a computer-assisted morphometric system. Sarcoplasmic reticulum Ca(2+) ATPase (SERCA2), phospholamban (PLN), phospho-Ser(16)-PLN, phospho-Thr(17)-PLN, phosphatase 1 (PP1), Na(+)-Ca(2+) exchanger (NCX), Ca(2+)/calmodulin-dependent protein kinase 11 (CaMKII) and phospho-Thr(286)-CaMKII were analyzed by Western blot. Key findings: alpha(2A)/alpha(2C)ARKO mice displayed ventricular dysfunction, cardiomyocyte hypertrophy and cardiac fibrosis paralleled by decreased SERCA2 and increased phospho-Thr(17)-PLN, CaMKII, phospho-Thr(286)-CaMKII and NCX levels. ARB induced anti-cardiac remodeling effect and improved VF in alpha(2A)/alpha(2C)ARKO associated with increased SERCA2 and phospho-Ser(16)-PLN levels, and SERCA2:NCX ratio. Additionally, ARB decreased phospho-Thr(17)-PLN levels as well as reestablished NCX, CaMKII and phospho-Thr(286)-CaMKII toward WT levels. Significance: Altogether, these data provide new insights on intracellular Ca(2+) regulatory mechanisms underlying improved ventricular function by ARB therapy in HF. (c) 2011 Elsevier Inc. All rights reserved.

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The purpose of this work was to evaluate the effects of ethylene action blockade and cold storage on the ripening of `Golden` papaya fruit. Papayas harvested at maturity stage 1 (up to 15% yellow skin) were evaluated. Half of the fruits, whether treated or not treated with 100 nL L(-1) of 1-methylcyclopropene (1-MCP), were stored at 23A degrees C, while the other half were stored at 11A degrees C for 20 days prior to being stored at 23A degrees C. Non-refrigerated fruits receiving 1-MCP application presented a reduction in respiratory activity, ethylene production, skin color development and pectinmethylesterase activity. Even with a gradual increase in ethylene production at 23A degrees C, fruits treated with 1-MCP maintained a high firmness, but presented a loss of green skin color. Cold storage caused a decrease in ethylene production when fruits were transferred to 23A degrees C. The results suggest that pulp softening is more dependent on ethylene than skin color development, and that some processes responsible for loss of firmness do not depend on ethylene.

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Disorders of androgen production can occur in all steps of testosterone biosynthesis and secretion carried out by the foetal Leydig cells as well as in the conversion of testosterone into dihydrotestosterone (DHT). The differentiation of Leydig cells from mesenchymal cells is the first walk for testosterone production. In 46,XY disorders of sex development (DSDs) due to Leydig cell hypoplasia, there is a failure in intrauterine and postnatal virilisation due to the paucity of interstitial Leydig cells to secrete testosterone. Enzymatic defects which impair the normal synthesis of testosterone from cholesterol and the conversion of testosterone to its active metabolite DHT are other causes of DSD due to impaired androgen production. Mutations in the genes that codify the enzymes acting in the steps from cholesterol to DHT have been identified in affected patients. Patients with 46,XY DSD secondary to defects in androgen production show a variable phenotype, strongly depending of the specific mutated gene. Often, these conditions are detected at birth due to the ambiguity of external genitalia but, in several patients, the extremely undervirilised genitalia postpone the diagnosis until late childhood or even adulthood. These patients should receive long-term care provided by multidisciplinary teams with experience in this clinical management. (C) 2009 Elsevier Ltd. All rights reserved.

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Suppression of the renin-angiotensin system during lactation causes irreversible renal structural changes. In this study we investigated 1) the time course and the mechanisms underlying the chronic kidney disease caused by administration of the AT(1) receptor blocker losartan during lactation, and 2) whether this untoward effect can be used to engender a new model of chronic kidney disease. Male Munich-Wistar pups were divided into two groups: C, whose mothers were untreated, and L(Lact), whose mothers received oral losartan (250 mg.kg(-1).day(-1)) during the first 20 days after delivery. At 3 mo of life, both nephron number and the glomerular filtration rate were reduced in L(Lact) rats, whereas glomerular pressure was elevated. Unselective proteinuria and decreased expression of the zonula occludens-1 protein were also observed, along with modest glomerulosclerosis, significant interstitial expansion and inflammation, and wide glomerular volume variation, with a stable subpopulation of exceedingly small glomeruli. In addition, the urine osmolality was persistently lower in L(Lact) rats. At 10 mo of age, L(Lact) rats exhibited systemic hypertension, heavy albuminuria, substantial glomerulosclerosis, severe renal interstitial expansion and inflammation, and creatinine retention. Conclusions are that 1) oral losartan during lactation can be used as a simple and easily reproducible model of chronic kidney disease in adult life, associated with low mortality and no arterial hypertension until advanced stages; and 2) the mechanisms involved in the progression of renal injury in this model include glomerular hypertension, glomerular hypertrophy, podocyte injury, and interstitial inflammation.

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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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In recent years, beta-blocker therapy has become a primary pharmacologic intervention in patients with heart failure by blocking the sympathetic activity. To compare the exercise training`s sympathetic blockade in healthy subjects (athletes) and the carvedilol`s sympathetic blockade in sedentary heart failure patients by the evaluation of the heart rate dynamic during an exercise test. A total of 26 optimized and 49 nonoptimized heart failure patients in a stable condition (for, at least, 3 months), 15 healthy athletes and 17 sedentary healthy subjects were recruited to perform a cardiopulmonary exercise test. The heart rate dynamic (rest, reserve, peak and the peak heart rate in relation to the maximum predicted for age) was analyzed and compared between the four groups. The heart rate reserve was the same between optimized (48 +/- 15) and nonoptimized (49 +/- 18) heart failure patients (P < 0.0001). The athletes (188 +/- 9) showed a larger heart rate reserve compared to sedentary healthy subjects (92 +/- 10, P < 0.0001). Athletes and healthy sedentary reached the maximum age-predicted heart ratefor their age, but none of the heart failure patients did. The carvedilol`s sympathetic blockade occurred during the rest and during the peak effort in the same proportion, but the exercise training`s sympathetic blockade in healthy subjects occurred mainly in the rest.

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One of the main obstacles for understanding biological events involved in cancer is the lack of experimental models for in vitro studies especially for prostate cancer (PC).There are a limited number of PC cell lines being the majority originated from metastatic tumors mostly acquired from American Tissue Cell Culture which demands importation an expensive and bureaucratic process. Also it is well known that there are ethnic differences between populations concerning the behavior of tumors and the research based on cell lines derived from Brazilians should be interesting. Our aim was to develop tumor cell lines from primary PC.

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Myofibroblast development and haze generation in the corneal stroma is mediated by cytokines, including transforming growth factor-beta (TGF-beta), and possibly other cytokines. This study examined the effects of stromal PDGF-beta blockade on the development of myofibroblasts in response to -9.0 diopter photorefractive keratectomy in the rabbit. Rabbits that had haze generating photorefractive keratectomy (PRK, for 9 diopters of myopia) in one eye were divided into three different groups: stromal application of plasmid pCMV.PDGFRB.23KDEL expressing a subunit of PDGF receptor b (domains 2-3, which bind PDGF-B), stromal application of empty plasmid pCMV, or stromal application of balanced salt solution (BSS). The plasmids (at a concentration 1000 ng/mu l) or BSS was applied to the exposed stroma immediately after surgery and every 24 h for 4-5 days until the epithelium healed. The group treated with pCMV.PDGFRB.23KDEL showed lower alpha SMA+ myofibroblast density in the anterior stroma compared to either control group (P <= 0.001). Although there was also lower corneal haze at the slit lamp at one month after surgery, the difference in haze after PDGF-B blockade was not statistically significant compared to either control group. Stromal PDGF-B blockade during the early postoperative period following PRK decreases stromal alpha SMA+ myofibroblast generation. PDGF is an important modulator of myofibroblast development in the cornea. (C) 2008 Elsevier Ltd. All rights reserved.

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CAPES/PRODOC, FAPESP[98/15013-9]

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Pires-Oliveira M, Maragno AL, Parreiras-E-Silva LT, Chiavegatti T, Gomes MD, Godinho RO. Testosterone represses ubiquitin ligases atrogin-1 and Murf-1 expression in an androgen-sensitive rat skeletal muscle in vivo. J Appl Physiol 108: 266-273, 2010. First published November 19, 2009; doi:10.1152/japplphysiol.00490.2009.-Skeletal muscle atrophy induced by denervation and metabolic diseases has been associated with increased ubiquitin ligase expression. In the present study, we evaluate the influence of androgens on muscle ubiquitin ligases atrogin-1/MAFbx/FBXO32 and Murf-1/Trim63 expression and its correlation with maintenance of muscle mass by using the testosterone-dependent fast-twitch levator ani muscle (LA) from normal or castrated adult male Wistar rats. Gene expression was determined by qRT-PCR and/or immunoblotting. Castration induced progressive loss of LA mass (30% of control, 90 days) and an exponential decrease of LA cytoplasm-to-nucleus ratio (nuclear domain; 22% of control after 60 days). Testosterone deprivation induced a 31-fold increase in LA atrogin-1 mRNA and an 18-fold increase in Murf-1 mRNA detected after 2 and 7 days of castration, respectively. Acute (24 h) testosterone administration fully repressed atrogin-1 and Murf-1 mRNA expression to control levels. Atrogin-1 protein was also increased by castration up to 170% after 30 days. Testosterone administration for 7 days restored atrogin-1 protein to control levels. In addition to the well known stimulus of protein synthesis, our results show that testosterone maintains muscle mass by repressing ubiquitin ligases, indicating that inhibition of ubiquitin-proteasome catabolic system is critical for trophic action of androgens in skeletal muscle. Besides, since neither castration nor androgen treatment had any effect on weight or ubiquitin ligases mRNA levels of extensor digitorum longus muscle, a fast-twitch muscle with low androgen sensitivity, our study shows that perineal muscle LA is a suitable in vivo model to evaluate regulation of muscle proteolysis, closely resembling human muscle responsiveness to androgens.

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The dorsal premammillary nucleus (PMd) is a hypothalamic structure that plays a pivotal role in the processing of predatory threats. Lesions of this nucleus virtually eliminate the expression of defensive responses to predator exposure. However, little is known about the neurotransmitters responsible for these behavioral responses. Since PMd neurons express ionotropic glutamate receptors and exposure to predators have been shown to activate nitric oxide (NO) producing cells in this region, the aim of this study was to verify the involvement of glutamate and NO-mediated neurotransmission in defensive reactions modulated by the PMd. We tested in male Wistar rats the hypothesis that intra-PMd injection of the NMDA receptor antagonist, AP7, or the NO synthase inhibitor, N-propyl-L-arginine (NP), would attenuate behavioral responses induced by cat exposure. Our results showed that both AP7 and NP significantly attenuated the behavioral responses induced by the live cat. These results suggest that the NMDA/NO pathway plays an important role in the behavioral responses mediated by the PMd. (C) 2011 Elsevier Inc. All rights reserved.