183 resultados para Beta-adrenoceptor Blockade
Resumo:
Substance P (SP) is a neuropeptide that can modulate inflammatory mediator release through activation of NK(1) receptors (NK(1)R). Some studies have also suggested the involvement of SP in lipopolysaccharide (LPS)-induced fever. However, the precise contribution of this neuropeptide to the pathways activated during fever is unknown. In this study we investigated the effect of a selective NK(1)R antagonist, SR140333B, on the febrile response induced by LPS and cytokines. Our results show that the systemic injection of SR140333B did not modify the fever induced by LPS at a dose that is able to reduce protein extravasation induced by SP in the skin. On the other hand, intracerebroventricular administration of 5R140333B significantly reduced the fever induced by peripheral injection of LPS. These data emphasize an important role for SP in the central nervous system during the febrile response to LPS, and are reinforced by the fact that intracerebroventricular injection of SP also induced fever in a dose-dependent manner in captopril-treated rats. Considering that the febrile response can result from the generation of several endogenous pyrogens, among them interleukin (IL)-1 beta and macrophage inflammatory protein-1 alpha (CCL3/MIP-1 alpha), we also examined the effect of SR140333B on the fever induced by these cytokines which act through prostaglandin-dependent and independent mechanisms, respectively. Surprisingly, SR140333B did not modify the febrile response to IL-1 beta or CCL3/MIP-1 alpha. Altogether these data suggest that the central action of SP is essential for LPS-, but not for IL-1 beta- or CCL3/MIP-1 alpha-induced fever. (C) 2011 Elsevier B.V. All rights reserved.
Resumo:
Introduction: Prune belly syndrome (PBS) presents with large-capacity bladders, high compliance and post-void residual volumes. Operative and conservative treatments are controversial. When histologically compared to normal bladder, bladder outlet obstruction results in an up- or down-regulation of adrenoceptors. Our goal was to study the immunoexpression of adrenoceptors in detrusor from patients with PBS. Materials and methods: Bladder domes from PBS patients (n = 14) were studied (PBG). For normal controls, bladder specimens were obtained at adult surgery (n = 13) (CG1) and at child autopsy (n = 5) (CG2). Staining was performed using antibodies to alpha 1a, alpha 1b, alpha 1d and beta 3 adrenoceptors. Five to 10 images were captured on an optic microscope with a digital camera and analysed with Photoshop(R). The immunocyhistochemical index with arbitrary units was calculated and compared. Results: Mean age was 1.28, 64 and 1.41 years for PBG, CG1 and CG2, respectively. The immunohistochemical index with arbitrary units of alpha 1a receptors was 0.06 in PBG, 0.16 in CG1 and 0.14 in CG2 (p = 0.008); of alpha 1b 0.06, 0.06 and 0.07 (p = 0.781); and of alpha 1d 0.04, 0.04 and 0.05 (p = 0.618). Regarding beta 3 the respective values were 0.07, 0.14 and 0.10 (p = 0.378). Conclusion: Our results show a decrease in ala-adrenoceptor immunostaining intensity in detrusor from children with PBS. Further in vitro studies are needed to determine whether these observations are physiologically significant. (C) 2009 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
Resumo:
Although a new protocol of dobutamine stress echocardiography with the early injection of atropine (EA-DSE) has been demonstrated to be useful in reducing adverse effects and increasing the number of effective tests and to have similar accuracy for detecting coronary artery disease (CAD) compared with conventional protocols, no data exist regarding its ability to predict long-term events. The aim of this study was to determine the prognostic value of EA-DSE and the effects of the long-term use of beta blockers on it. A retrospective evaluation of 844 patients who underwent EA-DSE for known or suspected CAD was performed; 309 (37%) were receiving beta blockers. During a median follow-up period of 24 months, 102 events (12%) occurred. On univariate analysis, predictors of events were the ejection fraction (p <0.001), male gender (p <0.001), previous myocardial infarction (p <0.001), angiotensin-converting enzyme inhibitor therapy (p = 0.021), calcium channel blocker therapy (p = 0.034), and abnormal results on EA-DSE (p <0.001). On multivariate analysis, the independent predictors of events were male gender (relative risk [RR] 1.78, 95% confidence interval [CI] 1.13 to 2.81, p = 0.013) and abnormal results on EA-DSE (RR 4.45, 95% CI 2.84 to 7.01, p <0.0001). Normal results on EA-DSE with P blockers were associated with a nonsignificant higher incidence of events than normal results on EA-DSE without beta blockers (RR 1.29, 95% CI 0.58 to 2.87, p = 0.54). Abnormal results on EA-DSE with beta blockers had an RR of 4.97 (95% CI 2.79 to 8.87, p <0.001) compared with normal results, while abnormal results on EA-DSE without beta blockers had an RR of 5.96 (95% CI 3.41 to 10.44, p <0.001) for events, with no difference between groups (p = 0.36). In conclusion, the detection of fixed or inducible wall motion abnormalities during EA-DSE was an independent predictor of long-term events in patients with known or suspected CAD. The prognostic value of EA-DSE was not affected by the long-term use of beta blockers. (C) 2008 Elsevier Inc. All rights reserved. (Am J Cardiol 2008;102:1291-1295)
Resumo:
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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Although administration of 17 beta-estradiol (estrogen) following trauma-hemorrhage attenuates the elevation of cytokine production and mitogen-activated protein kinase (MAPK) activation in epidermal keratinocytes, whether the salutary effects of estrogen are mediated by estrogen receptor (ER)-alpha. or ER-beta is not known. To determine which estrogen receptor is the mediator, we subjected C3H/HeN male mice to trauma-hemorrhage (2-cm midline laparotomy and bleeding of the animals to a mean blood pressure of 35 mmHg and maintaining that pressure for 90 min) followed by resuscitation with Ringer`s lactate (four times the shed blood volume) At the middle of resuscitation we subcutaneously injected ER-alpha agonist propyl pyrazole trial (PPT; 5 mu g/kg), ER-beta agonist diarylpropionitrile (DPN; 5 mu g/kg), estrogen (50 mu g/kg), or ER antagonist ICI 182,780 (150 mu g/kg). Two hours after resuscitation, we isolated keratinocytes, stimulated them with lipopolysaccharide for 24 In (5 mu g/mL for maximum cytokine production), and measured the production of interleukin (IL)-6, IL-10, IL-12, and INF-alpha and the activation of MAPK. Keratinocyte cytokine production markedly increased and MAPK activation occurred following trauma-hemorrhage but were normalized by administration of estrogen, PPT and DPN. PPT and DPN administration were equally effective in normalizing the inflammatory response of keratinocytes, indicating that both ER-alpha. and ER-beta mediate the salutary effects of estrogen on kerotinocytes after trauma-hemorrhage.
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The goal of this study was to investigate how the Arg386Pro mutation prolongs KiSS-1 receptor (KISS1R) responsiveness to kisspeptin, contributing to human central precocious puberty. Confocal imaging showed colocalization of wild-type (WT) KISS1R with a membrane marker, which persisted for up to 5 h of stimulation. Conversely, no colocalization with a lysosome marker was detected. Also, overnight treatment with a lysosome inhibitor did not affect WT KISS1R protein, whereas overnight treatment with a proteasome inhibitor increased protein levels by 24-fold. WT and Arg386Pro KISS1R showed time-dependent internalization upon stimulation. However, both receptors were recycled back to the membrane. The Arg386Pro mutation did not affect the relative distribution of KISS1R in membrane and internalized fractions when compared to WT KISS1R for up to 120 min of stimulation, demonstrating that this mutation does not affect KISS1R trafficking rate. Nonetheless, total Arg386Pro KISS1R was substantially increased compared with WT after 120 min of kisspeptin stimulation. This net increase was eliminated by blockade of detection of recycled receptors, demonstrating that recycled receptors account for the increased responsiveness of this mutant to kisspeptin. We therefore conclude the following: 1) WT KISS1R is degraded by proteasomes rather than lysosomes; 2) WT and Arg386Pro KISS1R are internalized upon stimulation, but most of the internalized receptors are recycled back to the membrane rather than degraded; 3) the Arg386Pro mutation does not affect the rate of KISS1R trafficking-instead, it prolongs responsiveness to kisspeptin by decreasing KISS1R degradation, resulting in the net increase on mutant receptor recycled back to the plasma membrane.(Endocrinology 152: 1616-1626,2011)
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In type 2 diabetes (DM2) there is progressive deterioration in beta-cell function and mass. It was found that islet function was about 50% of normal at the time of diagnosis and reduction in beta-cell mass of about 60% at necropsy (accelerated apoptosis). Among the interventions to preserve the beta-cells, those to lead to short-term improvement of beta-cell secretion are weight loss, metformin, sulfonylureas, and insulin. The long-term improvement was demonstrated with short-term intensive insulin therapy of newly diagnosed DM2, the use of antiapoptotic drugs such as glitazones, and the use of glucagon-like peptide-1 receptor agonists (GLP-1 mimetics), not inactivated by the enzyme dipeptidyl peptidase 4 and/or to inhibit that enzyme (GLP-1 enhancers). The incretin hormones are released from the gastrointestinal tract in response to nutrient ingestion to enhance glucose-dependent insulin secretion from the pancreas and overall maintenance of glucose homeostasis. From the two major incretins, GLP-1 and GIP (glucose-dependent insulinotropic polypeptide), only the first one or its mimetics or enhancers can be used for treatment. The GLP-1 mimetics exenatide and liraglutide as well as the DPP4 inhibitors (sitagliptin and vildagliptin) were approved for treatment of DM2.
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Background/Aim: Galectin-3 has been associated with activated Wnt pathway, translocating beta-catenin into the nucleus. However, it is still unknown whether this lectin drives the Wnt signaling activation in lesions from galectin-3-deficient (Gal3(-/-)) mice. The purpose was to study beta-catenin expression in tongue lesions from Gal3(-/-) and wildtype (Gal3(+/+)) mice and the status of Wnt signaling. Materials and Methods: Twenty Gal3(-/-) and Gal3(+/+) male mice were challenged with 4-nitroquinolin-1-oxide and killed at week 16 and 32. Tongues were processed and stained with H&E to detect dysplasias and carcinomas. An imunohistochemical assay was performed to evaluate beta-catenin expression. Results: Carcinomas were more evident in Gal3(+/+) than Gal3(-/-) mice (55.5% vs. 28.5%, respectively; p>0.05). Elevated expression of non-membranous beta-catenin was observed in dysplasias and carcinomas from both groups (p>0.05). Conclusion: Absence of galectin-3 does not interfere in the pattern of beta-catenin expression and therefore in the mediation of the Wnt signaling pathway.
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The PKC apoptosis WTI regulator gene, also named prostate apoptosis response-4 (PAR-4), encodes a pro-apoptotic protein that sensitizes cells to numerous apoptotic stimuli. Insulin-like growth factor-1 (IGF-1) and 17 beta-estradiol (E2), two important factors for breast cancer development and progression, have been shown to down-regulate PAR-4 expression and inhibit apoptosis induced by PAR-4 in neuronal cells. In this study, we sought to investigate the mechanisms of regulation of PAR-4 gene expression in MCF-7 cells treated with E2 or IGF-1. E2 (10 nM) and IGF-1 (12.5 nM) each down-regulated PAR-4 expression in MCF-7 cells after 24 h of treatment. The effect of E2 was dependent on ER activation, as demonstrated by an increase in PAR-4 expression when cells were pretreated for 1 h with 1 mu M ICI-182,780 (ICI) before receiving E2 plus ICI. The effect of IGF-1 was abolished by pre-treatment for 1 h with 30 mu M LY294002 (a specific PI3-K inhibitor), and significantly inhibited by 30 mu M SB202190 (a specific p38MAPK inhibitor). We also demonstrated that E2 acts synergistically with IGF-1, resulting in greater down-regulation of PAR-4 mRNA expression compared with E2 or IGF-1 alone. Our results show for the first time that E2 and IGF-1 inhibit PAR-4 gene expression in MCF-7 cells, suggesting that this down-regulation may provide a selective advantage for breast cancer cell survival.
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alpha(5)beta(1) integrin from both wild-type CHO cells (CHO-K1) and deficient in proteoglycan biosynthesis (CHO-745) is post-translationally modified by glycosaminoglycan chains. We demonstrated this using [(35)S]sulfate metabolic labeling of the cells, enzymatic degradation, immunoprecipitation reaction with monoclonal antibody, fluorescence microscopy, and flow cytometry. The alpha(5)beta(1) integrin heterodimer is a hybrid proteoglycan containing both chondroitin and heparan sulfate chains. Xyloside inhibition of sulfate incorporation into alpha(5)beta(1) integrin also supports that integrin is a proteoglycan. Also. cells grown with xyloside adhered on fibronectin with no alteration in alpha(5)beta(1) integrin expression. However, haptotactic motility on fibronectin declined in cells grown with xyloside or chlorate as compared with controls. Thus, alpha(5)beta(1) integrin is a proteoglycan and the glycosaminoglycan chains of the integrin influence cell motility on fibronectin. Similar glycosylation of alpha(5)beta(1) integrin was observed in other normal and malignant cells, suggesting that this modification is conserved and important in the function of this integrin. Therefore, these glycosaminoglycan chains of alpha(5)beta(1) integrin are involved in cellular migration on fibronectin.
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The ADAM23 gene is frequently silenced in different types of tumors, and, in breast tumors, silencing is correlated with tumor progression, suggesting that it might be associated with the acquisition of a metastatic phenotype. ADAM23 exerts its function mainly through the disintegrin domain, because its metalloprotease domain is inactive. Analysis of ADAM23 binding to integrins has revealed a specific interaction with alpha(v)beta(3) integrin mediated by the disintegrin domain. Altered expression of alpha(v)beta(3) integrin has been observed in different types of tumors, and expression of this integrin in the activated form has been shown to promote metastasis formation. Here, we investigated the possibility that interaction between ADAM23 and alpha(v)beta(3) integrin might negatively modulate alpha(v)beta(3) activation during metastatic progression. ADAM23 expression was knocked down using short hairpin RNA in the MDA-MB-435 cell line, which has been extensively used as a model for alpha(v)beta(3) integrin activation. Ablation of ADAM23 enhanced alpha(v)beta(3) integrin activation by at least 2- to 4-fold and ADAM23 knockdown cells showed enhanced migration and adhesion to classic alpha(v)beta(3) integrin ligands. Ablation of ADAM23 expression also enhanced pulmonary tumor cell arrest in immunodeficient mice. To complement our findings with clinical evidence, we showed that silencing of ADAM23 gene by DNA promoter hypermethylation in a collection of 94 primary breast tumors was significantly associated with lower distant metastases-free and disease-specific survivals and was an independent prognostic factor for poor disease outcome. Our results strongly support a functional role of ADAM23 during metastatic progression by negatively modulating alpha(v)beta(3) integrin activation. [Cancer Res 2009;69(13):5546-52]
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Background and Aim: Although prophylaxis with beta-blockers has been shown to decrease variceal pressure and wall tension in cirrhotic patients, this has not been demonstrated in non-cirrhotic portal hypertension caused by Schistosoma mansoni infection. Methods: Thirteen patients without history of previous gastrointestinal bleeding were included. All of them had high-risk esophageal varices at endoscopy. An endoscopic gauge and a high-frequency endoscopic ultrasonography miniprobe were used to assess transmural variceal pressure and wall tension before and after achieving beta-blockade with propranolol. Results: Baseline variceal pressure decreased from 13.3 +/- 3.5 to 8.2 +/- 2.0 mmHg (P < 0.0001) and wall tension from 500.2 +/- 279.8 to 274.0 +/- 108.3 mg.mm-1. The overall effect of propranolol on decreasing variceal pressure and wall tension expressed in percentage change in relation to baseline values was 35.7 +/- 18.4% and 35.9 +/- 26.7%, respectively (P = 0.9993). Conclusion: Propranolol significantly reduced variceal pressure and wall tension in schistosomiasis.
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Objective: To assess the association between the depth of trophoblastic penetration into the tubal wall with serum concentrations of vascular endothelial growth factor (VEGF) and beta-hCG and to assess its predictive value. Design: Prospective study. Setting: Tertiary care university hospital. Patient(s): Thirty patients with ampullary pregnancy undergoing salpingectomy were analyzed. Intervention(s): Trophoblastic invasion was histologically classified as stage I when limited to the tubal mucosa, stage II when extending to the muscle layer, and stage III in the case of complete tubal wall infiltration. Main Outcome Measure(s): The relation between depth of trophoblastic infiltration into the tubal wall with VEGF and beta-hCG serum concentrations on the day of surgery. Result(s): An association between the depth of trophoblastic invasion and maternal serum concentrations of VEGF and beta-hCG was observed. VEGF levels of 297.2 pg/mL showed 100.0% sensitivity and 90.0% specificity for stage I, and levels of 440.1 pg/mL showed 81.8% sensitivity and 88.8% specificity for stage III. Beta-hCG levels of 2590.0 mIU/mL showed 88.9% sensitivity and 80.0% specificity for stage I, and levels of 10,827.0 mUI/mL showed 72.7% sensitivity and 88.9% specificity for stage III. Conclusion(s): Maternal serum VEGF and beta-hCG concentrations are associated with depth of trophoblastic penetration into the tubal wall. (Fertil Steril (R) 2010;94:1595-600. (C) 2010 by American Society for Reproductive Medicine.)
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Objective: To assess the serum levels of interleukin 1 beta (IL-1 beta) in elderly depressed patients in comparison with nondepressed healthy elderly subjects. Design: Cross-sectional study. Setting: Tertiary memory clinic. Participants: Twenty-three antidepressant-free elderly depressed patients and 44 nondepressed healthy elderly comparison group were enrolled to this study. Measurement: Serum IL-1 beta levels were determined with highly sensitive colorimetric sandwich enzyme-linked immunosorbent assay. Severity of the depressive episode was determined by scores on the Hamilton Depression Scale-21 item and cognitive performance by the scores on the Cambridge Cognition Examination, Mini Mental State Examination clock drawing test, and verbal fluency. Results: IL-1 beta serum levels were increased in elderly patients versus nondepressed elderly (t = 2.21, df = 65, p = 0.04). After categorizing elderly depressed subjects into late onset (LOD) versus early onset (EOD), patients with EOD had the highest IL-1 beta levels, when compared with nondepressed elderly patients and patients with LOD in analysis of variance (F = 4.9, df = 2, 64, p < 0.01). Conclusions: Late-life depression is associated with higher IL-1 beta levels suggesting that increased proinflammatory state may play a role in the physiopathology of depression in the elderly. The authors further show that this might be more prominent in those patients with EOD geriatric depression. (Am J Geriatr Psychiatry 2010; 18: 172-176)
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Carcinoma ex-pleomorphic adenoma (CXPA) is an aggressive salivary gland malignancy, usually derived from a long-standing or a recurrent benign tumor, the pleomorphic adenoma (PA). In the context of dynamic reciprocity, changes in the composition and structure of extracellular matrix proteins and cell surface receptors have been frequently associated with dysfunctional adhesion and invasive behavior of tumor cells. It is not fully understood if these changes are involved in the conversion of PA to CXPA. In this study, different progression stages of CXPA were investigated regarding the expression of the major extracellular matrix proteins, collagen type I, and of E-cadherin and beta-catenin, the components of adherens junctions. By immunohistochemical analysis, we have demonstrated that direct contact of tumor cells with fibrillar type I collagen, particularly near the invasive front and in invasive areas prevailing small nests of CXPA cells, could be associated with reduced expression of the E-cadherin and beta-catenin adhesion molecules and with invasive behavior of epithelial; but not of CXPA with myoepithelial component. Our results also suggested that this association could depend on the organization of collagen molecules, being prevented by high-order polymeric structures. These findings could implicate the local microenvironment in the transition from the premalignant PA to invasive CXPA.