927 resultados para INHIBITOR NAMI-A
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Background-The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial in 2368 patients with stable ischemic heart disease assigned before randomization to percutaneous coronary intervention or coronary artery bypass grafting strata reported similar 5-year all-cause mortality rates with insulin sensitization versus insulin provision therapy and with a strategy of prompt initial coronary revascularization and intensive medical therapy or intensive medical therapy alone with revascularization reserved for clinical indication(s). In this report, we examine the predefined secondary end points of cardiac death and myocardial infarction (MI). Methods and Results-Outcome data were analyzed by intention to treat; the Kaplan-Meier method was used to assess 5-year event rates. Nominal P values are presented. During an average 5.3-year follow-up, there were 316 deaths (43% were attributed to cardiac causes) and 279 first MI events. Five-year cardiac mortality did not differ between revascularization plus intensive medical therapy (5.9%) and intensive medical therapy alone groups (5.7%; P = 0.38) or between insulin sensitization (5.7%) and insulin provision therapy (6%; P = 0.76). In the coronary artery bypass grafting stratum (n = 763), MI events were significantly less frequent in revascularization plus intensive medical therapy versus intensive medical therapy alone groups (10.0% versus 17.6%; P = 0.003), and the composite end points of all-cause death or MI (21.1% versus 29.2%; P = 0.010) and cardiac death or MI (P = 0.03) were also less frequent. Reduction in MI (P = 0.001) and cardiac death/MI (P = 0.002) was significant only in the insulin sensitization group. Conclusions-In many patients with type 2 diabetes mellitus and stable ischemic coronary disease in whom angina symptoms are controlled, similar to those enrolled in the percutaneous coronary intervention stratum, intensive medical therapy alone should be the first-line strategy. In patients with more extensive coronary disease, similar to those enrolled in the coronary artery bypass grafting stratum, prompt coronary artery bypass grafting, in the absence of contraindications, intensive medical therapy, and an insulin sensitization strategy appears to be a preferred therapeutic strategy to reduce the incidence of MI. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00006305. (Circulation. 2009;120:2529-2540.)
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Background The protease-activated receptor 1 (PAR-1), the main platelet receptor for thrombin, represents a novel target for treatment of arterial thrombosis, and SCH 530348 is an orally active, selective, competitive PAR-1 antagonist. We designed TRA.CER to evaluate the efficacy and safety of SCH 530348 compared with placebo in addition to standard of care in patients with non-ST-segment elevation (NSTE) acute coronary syndromes (ACS) and high-risk features. Trial design TRA.CER is a prospective, randomized, double-blind, multicenter, phase III trial with an original estimated sample size of 10,000 subjects. Our primary objective is to demonstrate that SCH 530348 in addition to standard of care will reduce the incidence of the composite of cardiovascular death, myocardial infarction (MI), stroke, recurrent ischemia with rehospitalization, and urgent coronary revascularization compared with standard of care alone. Our key secondary objective is to determine whether SCH 530348 will reduce the composite of cardiovascular death, MI, or stroke compared with standard of care alone. Secondary objectives related to safety are the composite of moderate and severe GUSTO bleeding and clinically significant TIMI bleeding. The trial will continue until a predetermined minimum number of centrally adjudicated primary and key secondary end point events have occurred and all subjects have participated in the study for at least I year. The TRA.CER trial is part of the large phase III SCH 530348 development program that includes a concomitant evaluation in secondary prevention. Conclusion TRA.CER will define efficacy and safety of the novel platelet PAR-1 inhibitor SCH 530348 in the treatment of high-risk patients with NSTE ACS in the setting of current treatment strategies. (Am Heart J 2009; 158:327-34.)
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Purpose: Erlotinib, an oral tyrosine kinase inhibitor, is active against head-and-neck squamous cell carcinoma (HNSCC) and possibly has a synergistic interaction with chemotherapy and radiotherapy. We investigated the safety and efficacy of erlotinib added to cisplatin and radiotherapy in locally advanced HNSCC. Methods and Materials: In this Phase I/II trial 100 mg/m(2) of cisplatin was administered on Days 8, 29, and 50, and radiotherapy at 70 Gy was started on Day 8. During Phase I, the erlotinib dose was escalated (50 mg, 100 mg, and 150 mg) in consecutive cohorts of 3 patients, starting on Day 1 and continuing during radiotherapy. Dose-limiting toxicity was defined as any Grade 4 event requiring radiotherapy interruptions. Phase 11 was initiated 8 weeks after the last Phase I enrollment. Results: The study accrued 9 patients in Phase I and 28 in Phase II; all were evaluable for efficacy and safety. No dose-limiting toxicity occurred in Phase I, and the recommended Phase 11 dose was 150 mg. The most frequent nonhematologic toxicities were nausea/vomiting, dysphagia, stomatitis, xerostomia and in-field dermatitis, acneiform rash, and diarrhea. Of the 31 patients receiving a 150-mg daily dose of erlotinib, 23 (74%; 95% confidence interval, 56.8%-86.3%) had a complete response, 3 were disease free after salvage surgery, 4 had inoperable residual disease, and 1 died of sepsis during treatment. With a median 37 months` follow-up, the 3-year progression-free and overall survival rates were 61% and 72%, respectively. Conclusions: This combination appears safe, has encouraging activity, and deserves further studies in locally advanced HNSCC. (C) 2010 Elsevier Inc.
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Stromal cells from pediatric myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) associated with MDS(MDS-AML) present high expression of leukemia inhibitor factor (LIF). We demonstrated using mitogen-activated protein kinase ( MAPK) inhibitors that in stromal cells from pediatric MDS and MDS-AML, p38MAPK was critical in serum-induced secretion of LIF. The serum induction of phosphorylated p38MAPK form was observed only in stromal cells from healthy children, whereas in MDS and MDS-AML basal levels were maintained suggesting constitutive p38MAPK activation. Our study suggested the possible importance in pediatric MDS of p38MAPK signaling pathway which may be a future therapeutic target. (C) 2009 Elsevier Ltd. All rights reserved.
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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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Albicidin phytotoxins are pathogenicity factors in a devastating disease of sugarcane known as leaf scald, caused by Xanthomonas albilineans. A gene (albD) from Pantoea dispersa has been cloned and sequenced and been shown to code for a peptide of 235 amino acids that detoxifies albicidin, The gene shows no significant homology at the DNA or protein level to any known sequence, but the gene product contains a GxSxG motif that is conserved in serine hydrolases, The AlbD protein, purified to homogeneity by means of a glutathione S-transferase gene fusion system, showed strong esterase activity on p-nitrophenyl butyrate and released hydrophilic products during detoxification of albicidins. AlbD hydrolysis of p-nitrophenyl butyrate and detoxification of albicidins required no complex cofactors, Both processes were strongly inhibited by phenylmethylsulfonyl fluoride, a serine enzyme inhibitor, These data strongly suggest that AlbD is an albicidin hydrolase, The enzyme detoxifies albicidins efficiently over a pH range from 5.8 to 8.0, with a broad temperature optimum from 15 to 35 degrees C, Expression of albD in transformed X. albilineans strains abolished the capacity to release albicidin toxins and to incite disease symptoms in sugarcane, The gene is a promising candidate for transfer into sugarcane to confer a form of disease resistance.
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Background Acral lentiginous melanoma (ALM) is a clinicopathologic subtype of cutaneous malignant melanoma. ALM is the most common type of melanoma amongst Asians, Africans, and patients with mixed ancestry. In Brazil, ALM comprises 10% of cutaneous melanoma. ALM develops on palmar, plantar, and subungual skin, and its biology is different from that of other cutaneous melanomas, where sunlight is the major known environmental determinant. Alterations and inactivation of the p16INK4 gene that encodes a specific inhibitor of cyclin-dependent kinase have been related to melanoma genesis and progression. Few studies, however, have addressed p16 expression in ALM. Methods In order to verify and compare p16 protein expression, 32 paraffin-embedded ALM specimens were subjected to a immunohistochemical technique using a monoclonal anti-p16 antibody. The tumors were classified according to thickness (up to 1.0 mm and thicker than 1.0 mm) and the presence of ulceration. Results Twenty-five (78%) ALMs displayed positive p16 protein expression: 21 of the 25 (84%) with a thickness of more than 1.0 mm, and four of the seven (57%) with a thickness of 1.0 mm or less. Thirteen of the 17 (76%) nonulcerated lesions and 12 of the 15 (80%) ulcerated lesions displayed positive p16 protein expression. Conclusion The data obtained suggest that p16 protein expression per se may not represent a marker of retinoblastoma protein (pRb) pathway disturbance in ALM tumorigenesis.
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Pemphigus foliaceus is a life threatening skin disease that is associated with autoimmunity to desmoglein, a skin protein involved in the adhesion of keratinocytes. This disease is endemic in certain areas of South America, suggesting the mediation of environmental factors triggering autoimmunity. Among the possible environmental factors, exposure to bites of black flies, in particular Simulittm nigrimanum has been suggested. In this work, we describe the sialotranscriptome of adult female S. nigrimanum flies. It reveals the complexity of the salivary potion of this insect, comprised by over 70 distinct genes within over 30 protein families, including several novel families, even when compared with the previously described sialotranscriptome of the autogenous black fly, S. vitiation. The uncovering of this sialotranscriptome provides a platform for testing pemphigus patient sera against recombinant salivary proteins from S. nigrimanum and for the discovery of novel pharmacologically active compounds.
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The present study aimed to evaluate the role of nitric oxide (NO) on hyperpnea-induced bronchoconstriction (HIB) and airway microvascular hyperpermeability (AMP). Sixty-four guinea pigs were anesthetized, tracheotonnized, cannulated, and connected to animal ventilator to obtain pulmonary baseline respiratory system resistance (Rrs). Animals were then submitted to 5 minutes hyperpnea and Rrs was evaluated during 15 minutes after hyperpnea. AMP was evaluated by Evans blue dye (25 mg/kg) extravasation in airway tissues. Constitutive and inductible NO was evaluated by pretreating animals with N(G)-nitro-1-arginine methyl ester (I-NAME) (50 mg/kg), aminoguadinine (AG) (50 mg/kg), and I-arginine (100 mg/kg) and exhaled NO (NOex) was evaluated before and after drug administration and hyperpnea. The results show that I-NAME potentiated (57%) HIB and this effect was totally reversed by I-arginine pretreatment, whereas AG did not have effect on HIB. I-NAME decreased basal AMP (48%), but neither I-NAME nor AG had any effect on hyperpnea-induced AMP. NOex levels were decreased by 50% with I-NAME, effect that was reversed by I-arginine treatment. These results suggest that constitutive but not inducible NO could have a bronchoprotective effect on HIB in guinea pigs. The authors also observed that neither constitutive nor inducible NO seems to have any effect on hyperpnea-induced AMP.
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The aims of this study were to characterize the recently cloned rat norepinephrine transporter (NET) in more detail and in particular to study possible species differences in its pharmacological properties compared with the human and bovine NETs. The study was carried out by measuring the uptake of [3H]norepinephrine in COS-7 cells expressing the NET after transient transfection with rat, human, or bovine NET cDNA. There were small but significant differences between the rat NET and the human or bovine NETs with respect to the affinities of sodium ions (greater for rat than for bovine) of the substrates norepinephrine, epinephrine, and 1-methyl-4-phenylpyridinium (greater for human than for rat), and of the inhibitor cocaine (greater for human and bovine than for rat), whereas the affinities of dopamine and of most inhibitors, including tricyclic antidepressants, showed no species differences. The fact that the affinities for some substrates, cocaine and sodium ions exhibited small but significant interspecies differences among the rat, human, and bovine NETs suggests that ligand recognition, the translocation process, and sodium ion dependence are influenced differentially by just a few amino acid exchanges in the primary sequences of the transporters. On the other hand, the lack of any major differences in the pharmacological properties of the rat, human, and bovine NETs in this study suggests that data obtained in previous studies on rat tissues and bovine cells can be extrapolated, in all except the most quantitative analyses, to the properties of the human NET.
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We have previously shown that human leukaemia inhibitory factor (hLIF) inhibits perivascular cuff-induced neointimal formation in the rabbit carotid artery. Since nitric oxide (NO) is a known inhibitor of smooth muscle growth, NO synthase (NOS) activity in the presence of hLIF was examined in vivo and in vitro. In rabbit aortic smooth muscle cell (SMC) culture, significant NOS activity was observed at 50 pg/ml hLIF, with maximal activity at 5 ng/ml. In the presence of the NOS inhibitor L-NAME, hLIF-induced activation of NOS was greatly decreased, however it was still 63-fold higher than in control (p < 0.05). SMC-DNA synthesis was significantly reduced (-47%) following incubation with hLIF plus L-arginine, the substrate required for NO production (p < 0.05), with no effect observed in the absence of L-arginine. Silastic cuff placement over the right carotid artery of rabbits resulted in a neointima 19.3 +/- 5.4% of total wall cross-sectional area, which was increased in the presence of L-NAME (27.0 +/- 2.0%; p < 0.05) and reduced in the presence of L-arginine (11.3 +/- 2.0%; p < 0.05). The effect of L-arginine was ameliorated by co-administration of L-NAME (16.4 +/- 1.5%). However, administration of L-NAME with hLIF had no effect on the potent inhibition of neointimal formation by hLIF (3.2 +/- 2.5 vs. 2.1 +/- 5.4%, respectively). Similarly, with hLIF administration, NOS activity in the cuffed carotid increased to 269.0 +/- 14.0% of saline-treated controls and remained significantly higher with coadministration of L-NAME (188.5 +/- 14.7%). These results indicate that hLIF causes superinduction of NO by SMC, and that it is, either partially or wholly, through this mechanism that hLIF is a potent inhibitor of neointimal formation in vivo and of smooth muscle proliferation in vitro.
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Introduction: Pancreas susceptibility to alcohol is variable and only 5-10% of chronic alcohol abusers develop chronic pancreatitis; the role of genetic factors in this process is unknown. The CFTR gene encodes a protein that acts on epithelial cells and plays a key role in normal exocrine pancreatic function. Methods: This study investigated the frequency of polymorphisms in intron 8 of the CFTR gene in patients with alcoholic chronic pancreatitis. Three groups of patients were studied: group A-68 adult alcoholics with a diagnosis of chronic pancreatitis; group B-68 adult alcoholics without pancreatic disease or liver cirrhosis and group C-104 healthy nonalcoholic adults. Results: T5/T7 genotype was more frequent in group A (11.8%) than in group B (2.9%) (p = 0.0481), and there was no statistical difference when groups A and C (5.8%) were compared (p = 0.1317). The haplotype combination (TG) 10-T7/(TG) 11-T7 was more frequent in groups B (23.5%) and C (20.2%) than in group A (7.3%) (p = 0.0080 and 0.0162). Conclusion: There are differences when these three groups are compared and individuals with T5/T7 genotype might have a greater risk of developing chronic pancreatitis when they become chronic alcoholics. Copyright (C) 2008 S. Karger AG, Basel and IAP
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Mobile Lipids detected using H-1-NMR in stimulated lymphocytes were correlated with cell cycle phase, expression of the interleukin-2 receptor alpha and proliferation to assess the activation status of the lymphocytes. Mobile lipid levels, IL-2R alpha expression and proliferation increased after treatment with PMA and ionomycin. PMA or ionomycin stimulation alone induced increased IL-2R alpha expressiom but not proliferation, PMA- but not ionomycin-stimulation generated mobile lipid, Treatment with anti-CD3 antibody did not increase IL-2R alpha expression or proliferation but did generate increased amounts of mobile lipid, The cell cycle status of thymocytes treated with anti-CD3, PMA or ionomycin alone indicated an. accumulation of the cells in the G(1) phase of the cell cycle, The generation of mobile lipid was abrogated in anti-CD3 antibody-stimulated thymic lymphocytes but not in splenic lymphocytes, using a phosphatidylcholine-specific phospholipase C (PC-PLC) inhibitor which blocked cells in the G(1)/S phase of the cell cycle, This suggests that the H-1-NMR-detectable mobile Lipid may be generated in anti-CD3 antibody-stimulated thymic lymphocytes by the action of PC-PLC activity via the catabolism of PC, in the absence of classical signs of activation. (C) 1997 Academic Press.
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The ability of mesenchymal stem cells to generate functional neurons in culture is still a matter of controversy. In order to assess this issue, we performed a functional comparison between neuronal differentiation of human MSCs and fetal-derived neural stem cells (NSCs) based on morphological, immunocytochemical, and electrophysiological criteria. Furthermore, possible biochemical mechanisms involved in this process were presented. NF200 immunostaining was used to quantify the yield of differentiated cells after exposure to CAMP. The addition of a PKA inhibitor and Ca(2+) blockers to the differentiation medium significantly reduced the yield of differentiated cells. Activation of CREB was also observed on MSCs during maturation. Na(+)-, K(+)-, and Ca(2+)-voltage-dependent currents were recorded from MSCs-derived cells. In contrast, significantly larger Na(+) currents, firing activity, and spontaneous synaptic currents were recorded from NSCs. Our results indicate that the initial neuronal differentiation of MSCs is induced by CAMP and seems to be dependent upon Ca(2+) and the PKA pathway. However, compared to fetal neural stem cells, adult mesenchymal counterparts are limited in their neurogenic potential. Despite the similar yield of neuronal cells, NSCs achieved a more mature functional state. Description of the underlying mechanisms that govern MSCs` differentiation toward a stable neuronal phenotype and their limitations provides a unique opportunity to enhance our understanding of stem cell plasticity. (C) 2009 Elsevier Inc. All rights reserved.
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To investigate the luteal phase endometrial expression of leukemia inhibitor factor (LIF), insulin-like growth factor 1 (IGF-1), progesterone receptor (PR), claudin 4 (CLDN4), vascular-endothelial growth factor receptor 3 (VEGFR-3), bone morphogenetic protein 4 (BMP-4) and citokeratin 7 (CK-7), we obtained luteal phase endometrial samples from 52 women. Samples were dated and integrated using a tissue microarray (TMA). Samples were immunostained for LIF, IGF-1, PR, CLDN4, VEGFR-3, BMP-4 and CK-7. Frequencies of positive expressions at the early, mid and late luteal phases were compared by two proportions test. Concomitant expression of these proteins was assessed with Chi-square or Fischer`s test. The frequency of LIF was positively correlated to the frequency of IGF-1 (r = 0.99; p < 0.05) and PR (r = 0.99; p < 0.05), and the correlation between IGF-1 and PR tended to be significant (r = 0.98; p < 0.1). The expression of PR was associated with the absence of CLDN4 (p < 0.001). Thus, expression of LIF, IGF-1 and PR are correlated during the luteal phase, and immunohistochemistry for these proteins might be used to assist in the assessment of endometrial maturation. In addition, the expression of CLDN4 and PR was not concomitant, warranting further investigation on the relationship of their endometrial expression.