170 resultados para DENV-4


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Background and Aims: Submucosal injection of a viscoelastic solution prolongs submucosal lift, thus, facilitating endoscopic mucosal resection. Our objective was to assess the safety and clinical effectiveness of 0.4% hydroxypropyl methylcellulose (HPMC) as a submucosal injectant for endoscopic mucosal resection. Patients and Methods: A prospective, open-label, multicenter, phase 2 study was conducted at 2 academic institutions in Brazil. Eligible participants included patients with early gastrointestinal tumors larger than 10 mm. Outcomes evaluated included complete resection rates, volume of HPMC injected, duration of the submucosal cushion as assessed visually, histology of the resected leisons, and complication rates. Results: Over a 12-month period, 36 eligible patients with superficial neoplastic lesions (stomach 14, colon 11, rectum 5, esophagus 3, duodenum 3) were prospectively enrolled in the study. The mean size of the resected specimen was 20.4 mm (10 to 60 mm). The mean volume of 0.4% HPMC injected was 10.7 mL (range 4 to 35 mL). The mean duration of the submucosal fluid cushion was 27 minutes (range 9 to 70 min). Complete resection was successfully completed in 89%. Five patients (14%) developed immediate bleeding requiring endoclip and APC application. Esophageal perforation occurred in 1 patient requiring surgical intervention. There were no local or systemic adverse events related to HPMC use over the follow-up period (mean 2.2 mo). Conclusion: HPMC solution (0.4%) provides an effective submucosal fluid cushion and is safe for endoscopic resection of early gastrointestinal neoplastic lesions.

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Substantial experimental evidence indicates that PAWR gene (PKC apoptosis WT1 regulator; also named PAR-4, prostate apoptosis response-4) is a central player in cancer cell survival and a potential target for cancer-selective targeted therapeutics. However, little is known about the role of PAR-4 in breast cancer. We investigated the possible role of PAR-4 expression in breast cancer. IHC results on tissue microarrays containing 1,161 primary breast tumor samples showed that 57% (571/995) of analyzable cases were negative for PAR-4 nuclear staining. Down-regulation of nuclear PAR-4 protein expression predicted a poor prognosis for breast cancer patients (OS; P=0.041, log-rank test). PAR-4 down-regulation also correlates with poor survival in the group of patients with luminal A subtype breast cancer (P=0.028). Additionally, in this large series of breast cancer patients, we show that ERBB2/HER2, EGFR and pAKT protein expression are significantly associated with shorter disease-free survival and overall survival, but the prognosis was even worse for HER2-positive, EGFR-positive or pAKT-positive breast cancer patients with tumors negative for nuclear PAR-4 expression. Furthermore, using three-dimensional (3D) cell culture we provide preliminary results showing that PAR-4 is highly expressed in the MCF10A cells inside the acini structure, suggesting that PAR-4 might have a role in the lumen acini formation. Taken together, our results provide, for the first time, evidence that PAR-4 may have a role in the process of the mammary eland morphogenesis and its functional inactivation is associated with tumor aggressive phenotype and might represent an additional prognostic and predictive marker for breast cancer.

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Phosphodiesterase (PDE) inhibition reduces skeletal muscle atrophy, but the underlying molecular mechanism remains unclear. We used microdialysis to investigate the effects of different PDE inhibitors on interstitial tyrosine concentration as well as proteolytic activity and atrogenes expression in isolated rat muscle. Rolipram, a PDE-4-selective inhibitor, reduced the interstitial tyrosine concentration and rates of muscle protein degradation. The rolipram-induced muscle cAMP increase was accompanied by a decrease in ubiquitin proteasome system (UPS) activity and atrogin-1 mRNA, a ubiquitin-ligase involved in muscle atrophy. This effect was not associated with Akt phosphorylation but was partially blocked by a protein kinase A inhibitor. Fasting increased atrogin-1, MuRF-1 and LC3b expression, and these effects were markedly suppressed by rolipram. Our data suggest that activation of cAMP signaling by PDE-4 blockade leads to inhibition of UPS activity and atrogenes expression independently of Akt. These findings are important for identifying novel approaches to attenuate muscle atrophy. Muscle Nerve 44: 371-381, 2011

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Culture filtrate proteins (CFP) are potential targets for tuberculosis vaccine development. We previously showed that despite the high level of gamma interferon (IFN-gamma) production elicited by homologous immunization with CFP plus CpG oligodeoxynucleotides (CFP/CpG), we did not observe protection when these mice were challenged with Mycobacterium tuberculosis. In order to use the IFN-gamma-inducing ability of CFP antigens, in this study we evaluated a prime-boost heterologous immunization based on CFP/CpG to boost Mycobacterium bovis BCG vaccination in order to find an immunization schedule that could induce protection. Heterologous BCG-CFP/CpG immunization provided significant protection against experimental tuberculosis, and this protection was sustained during the late phase of infection and was even better than that conferred by a single BCG immunization. The protection was associated with high levels of antigen-specific IFN-gamma and interleukin-17 (IL-17) and low IL-4 production. The deleterious role of IL-4 was confirmed when IL-4 knockout mice vaccinated with CFP/CpG showed consistent protection similar to that elicited by BCG-CFP/CpG heterologous immunization. These findings show that a single dose of CFP/CpG can represent a new strategy to boost the protection conferred by BCG vaccination. Moreover, different immunological parameters, such as IFN-gamma and IL-17 and tightly regulated IL-4 secretion, seem to contribute to the efficacy of this tuberculosis vaccine.

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The NO donor trans-[Ru(NO)(NH(3))(4)(py)](BF(4))(3).H(2)O (py = pyridine) was loaded into poly-lactic-co-glycolic acid (PLGA) microparticles using the double emulsification technique. Scanning electron microscopy (SEM) and dynamic light scattering revealed that the particles are spherical in shape, have a diameter of 1600 nm, and have low tendency to aggregate. The entrapment efficiency was 25%. SEM analysis of the melanoma cell B16-F10 in the presence of the microparticles containing the complex trans-[Ru(NO)(NH(3))(4)(py)](BF(4))(3).H(2)O (pyMP) showed that the microparticles were adhered to the cell surface after 2 h of incubation. The complex with concentrations lower than 1 x 10(-4) M did not show toxicity in B16-F 10 murine cells. The complex in solution is toxic at higher concentrations (> 1 x 10(-3) M), with cell death attributed to NO release following the reduction of the complex. pyMP is not cytotoxic due to the lower bioavailability and availability of the entrapped complex to the medium and its reducing agents. However, pyMP is phototoxic upon light irradiation. The phototoxicity strongly suggests that cell death is due to NO release from trans-[Ru(NO)(NH(3))(4)(py)](3+). This work shows that pyMP can serve as a model for a drug delivery system carrying the NO donor trans-[Ru(NO)(NH(3))(4)(py)](BF(4))(3).H(2)O, which can release NO locally at the tumor cell by radiation with light only. (c) 2007 Elsevier Inc. All rights reserved.

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Background Disease management programs (DMPs) are developed to address the high morbi-mortality and costs of congestive heart failure (CHF). Most studies have focused on intensive programs in academic centers. Washington County Hospital (WCH) in Hagerstown, MD, the primary reference to a semirural county, established a CHF DMP in 2001 with standardized documentation of screening and participation. Linkage to electronic records and state vital statistics enabled examination of the CHF population including individuals participating and those ineligible for the program. Methods All WCH inpatients with CHF International Classification of Diseases, Ninth Revision code in any position of the hospital list discharged alive. Results Of 4,545 consecutive CHF admissions, only 10% enrolled and of those only 52.2% made a call. Enrollment in the program was related to: age (OR 0.64 per decade older, 95% CI 0.58-0.70), CHF as the main reason for admission (OR 3.58, 95% CI 2.4-4.8), previous admission for CHF (OR 1.14, 95% CI 1.09-1.2), and shorter hospital stay (OR 0.94 per day longer, 95% CI 0.87-0.99). Among DMP participants mortality rates were lowest in the first month (80/1000 person-years) and increased subsequently. The opposite mortality trend occurred in nonenrolled groups with mortality in the first month of 814 per 1000 person-years in refusers and even higher in ineligible (1569/1000 person-years). This difference remained significant after adjustment. Re-admission rates were lower among participants who called consistently (adjusted incidence rate ratio 0.62, 95% CI 0.52-0.77). Conclusion Only a small and highly select group participated in a low-intensity DMP for CHF in a community-based hospital. Design of DMPs should incorporate these strong selective factors to maximize program impact. (Am Heart J 2009; 15 8:459-66.)

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Histoplasma capsulatum (Hc) is a facultative, intracellular parasite of worldwide significance. Infection with Hc produces a broad spectrum of diseases and may progress to a life-threatening systemic disease, particularly in individuals with HIV infection. Resolution of histoplasmosis is associated with the activation of cell-mediated immunity, and leukotriene B(4) plays an important role in this event. Lipid bodies (LBs) are increasingly being recognized as multifunctional organelles with roles in inflammation and infection. In this study, we investigated LB formation in histoplasmosis and its putative function in innate immunity. LB formation in leukocytes harvested from Hc-infected C57BL/6 mice peaks on day 2 postinfection and correlates with enhanced generation of lipid mediators, including leukotriene B(4) and PGE(2). Pretreatment of leukocytes with platelet-activating factor and BLT1 receptor antagonists showed that both lipid mediators are involved in cell signaling for LB formation. Alveolar leukocytes cultured with live or dead Hc also presented an increase in LB numbers. The yeast alkali-insoluble fraction 1, which contains mainly beta-glucan isolated from the Hc cell wall, induced a dose- and time-dependent increase in LB numbers, indicating that beta-glucan plays a signaling role in LB formation. In agreement with this hypothesis, beta-glucan-elicited LB formation was inhibited in leukocytes from 5-LO(-/-), CD18(low) and TLR2(-/-) mice, as well as in leukocytes pretreated with anti-Dectin-1 Ab. Interestingly, human monocytes from HIV-1-infected patients failed to produce LBs after beta-glucan stimulation. These results demonstrate that Hc induces LB formation, an event correlated with eicosanoid production, and suggest a role for these lipid-enriched organelles in host defense during fungal infection. The Journal of Immunology, 2009, 182: 4025-4035.

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Cardoso CR, Provinciatto PR, Godoi DF, Ferreira BR, Teixeira G, Rossi MA, Cunha FQ, Silva JS. IL-4 regulates susceptibility to intestinal inflammation in murine food allergy. Am J Physiol Gastrointest Liver Physiol 296: G593-G600, 2009. First published January 8, 2009; doi:10.1152/ajpgi.90431.2008.-Allergies involve a state of immediate hypersensitivity to antigens, including food proteins. The mechanism underlying the initiation and development of allergic responses involves IL-4 that directly induces the differentiation of committed effector Th2 lymphocytes. Although it is clear that Th2 responses play a pivotal role in the development of allergic responses, it remains unclear which mechanisms are involved in the development of the intestinal damages observed in food allergy. Accordingly, this work aimed to study the role of Th2/IL-4-dependent responses in the development of food allergy and intestinal pathology. C57BL/6 wild-type (WT) and IL-4(-/-) mice were sensitized with peanut proteins, challenged with peanut seeds, and followed for the development of food allergy and intestinal inflammation. Results demonstrated that exposure to peanut seeds led to weight loss in WT but not in IL-4(-/-) mice that preserved gut integrity with no signs of mucosal inflammation. These animals presented increased levels of IgG2a in sera, suggesting a role for allergic antibodies in the pathogenesis of WT animals. Most importantly, results also showed that lack of IL-4 modulated gut mucosal response in food allergy through diminished expression of TNF-alpha mRNA, increased Th1 IFN-gamma, IL-12p40, regulatory cytokines, and Foxp3, demonstrating their relevance in the control of allergic inflammatory processes, especially in the intestine. Finally, this study highlighted some of the complex mechanisms involved in the pathogenesis of allergic responses to food antigens in the gut, thereby providing valuable tools for directing novel therapeutic or preventive strategies to the control of allergic enteropathy.

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Background and purpose: We investigated the effect of nitric oxide synthase (NOS) inhibition on polymorphonuclear cell (PMN) influx in zymosan or lipopolysaccharide (LPS)-induced arthritis and peritonitis. Experimental approach: Wistar rats received intra-articular (i.art.) zymosan (30-1000 mu g) or LPS (1-10 mu g). Swiss C57/Bl6 mice genetically deficient in intercellular adhesion molecule-1 (ICAM-1(-/-)) or in beta(2)-integrin (beta(2)-integrin(-/-)) received zymosan either i.art. or i.p. PMN counts, leukotriene B(4) (LTB(4)), tumour necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) levels were measured in joint and peritoneal exudates. Groups received the NOS inhibitors N(G)-nitro-L-arginine methyl ester (LN), nitro-L-arginine, N-[3-(aminomemethyl) benzyl] acetamide or aminoguanidine, prior to zymosan or LPS, given i.p. or s.c. in the arthritis and peritonitis experiments respectively. A group of rats received LN locally (i.art. or i.p.), 30 min prior to 1 mg zymosan i.art. Key results: Systemic or local NOS inhibition significantly prevented PMN migration in arthritis while increasing it in peritonitis, regardless of stimuli, concentration of NOS inhibitors and species. NOS inhibition did not alter TNF-alpha and IL-10 but decreased LTB(4) in zymosan-induced arthritis. LN administration significantly inhibited PMN influx into the joints of ICAM-1(-/-) and beta(2)-integrin(-/-) mice with zymosan-arthritis, while not altering PMN influx into the peritoneum of mice with zymosan-peritonitis. Conclusions and implications: Nitric oxide has a dual modulatory role on PMN influx into joint and peritoneal cavities that is stimulus-and species-independent. Differences in local release of LTB(4) and in expression of ICAM-1 and beta(2)-integrin account for this dual role of NO on PMN migration.

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Subcutaneous heat-coagulated egg white implants (EWI) induce chronic, intense local eosinophilia in mice, followed by asthma-like responses to airway ovalbumin challenge. Our goal was to define the mechanisms of selective eosinophil accumulation in the EWI model. EWI carriers were challenged i.p. with ovalbumin and the contributions of cellular immunity and inflammatory mediators to the resulting leukocyte accumulation were defined through cell transfer and pharmacological inhibition protocols. Eosinophil recruitment required Major Histocompatibility Complex Class It expression, and was abolished by the leukotriene B4 (LTB4) receptor antagonist CP 105.696, the 5-lipoxygenase inhibitor BWA4C and the 5-lipoxygenase activating protein inhibitor MK886. Eosinophil recruitment in EWI carriers followed transfer of: a) CD4(+) (but not CD4(-)) cells, harvested from EWI donors and restimulated ex vivo; b) their cell-free supernatants, containing LTB4. Restimulation in the presence of MK886 was ineffective. CC chemokine receptor ligand (CCL)5 and CCL2 were induced by ovalbumin challenge in vivo. mRNA for CCL17 and CCL11 was induced in ovalbumin-restimulated CD4(+) cells ex vivo. MK886 blocked induction of CCL17 Pretreatment of EWI carriers with MK886 eliminated the effectiveness of exogenously administered CCL11, CCL2 and CCL5. In conclusion, chemokine-producing, ovalburnin-restimulated CD4(+) cells initiate eosinophil recruitment which is strictly dependent on LTB4 production. (C) 2008 Elsevier Inc. All rights reserved.

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Objective. To investigate the mechanism underlying neutrophil migration into the articular cavity in experimental arthritis and, by extension, human-inflammatory synovitis. Methods. Antigen-induced arthritis (AIA) was generated in mice with methylated bovine serum albumin (mBSA). Migration assays and histologic analysis were used to evaluate neutrophil recruitment to knee joints. Levels of inflammatory mediators were measured by enzyme-linked immunosorbent assay. Antibodies and pharmacologic inhibitors were used in vivo to determine the role of specific disease mediators. Samples of synovial tissue and synovial fluid from rheumatoid arthritis (RA) or osteoarthritis patients were evaluated for CXCL1 and CXCL5 expression. Results. High levels of CXCL1, CXCL5, and leukotriene B-4 (LTB4) were expressed in the joints of arthritic mice. Confirming their respective functional roles, repertaxin (a CXCR1/CXCR2 receptor antagonist), anti-CXCL1 antibody, anti-CXCL5 antibody, and MK886 (a leukotriene synthesis inhibitor) reduced mBSA-induced neutrophil migration to knee joints. Repertaxin reduced LTB4 production in joint tissue, and neutrophil recruitment induced by CXCL1 or CXCL5 was inhibited by MK886, suggesting a sequential mechanism. Levels of both CXCL1 and CXCL5 were elevated in synovial fluid and were released in vitro by RA synovial tissues. Moreover, RA synovial fluid neutrophils stimulated with CXCL1 or CXCL5 released significant amounts of LTB4. Conclusion. Our data implicate CXCL1, CXCL5, and LTB4, acting sequentially, in neutrophil migration in AIA. Elevated levels of CXCL1 and CXCL5 in the synovial compartment of RA patients provide robust comparative data indicating that this mechanism plays a role in inflammatory joint disease. Together, these results suggest that inhibition of. CXCL1, CXCL5, or LTB4 may represent a potential therapeutic strategy in RA.

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Recent in vitro data have suggested that the flavonoid quercetin (1) does not affect the functioning of neutrophils. Therefore, we evaluated in vivo and in vitro whether or not 1 affects neutrophil function, focusing on recruitment. The in vivo treatment with 1 inhibited in a dose-dependent manner the recruitment of neutrophils to the peritoneal cavity of mice induced by known chemotatic factors such as CXCL1, CXCL5, LTB(4), and fMLP. Further-more, 1 also inhibited in a concentration-dependent manner the chemoattraction of human neutrophils induced by CXCL8, LTB(4), and fMLP in a Boyden chamber. In vitro treatment with 1 did not affect human neutrophil surface expression of CXCR1, CXCR2, BLT1, or FLPR1, but rather reduced actin polymerization. These results suggest that 1 inhibits actin polymerization, hence, explaining the inhibition of neutrophil recruitment in vivo and in vitro and highlighting its possible usefulness to diminish excessive neutrophil migration during inflammation.

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BACKGROUND AND PURPOSE Lipoxin A(4) (LXA(4)) is a lipid mediator involved in the resolution of inflammation. Increased levels of LXA(4) in synovial fluid and enhanced expression of the formyl peptide receptor 2/lipoxin A(4) receptor (FPR2/ALX) in the synovial tissues of rheumatoid arthritis patients have been reported. Endothelins (ETs) play a pivotal pro-inflammatory role in acute articular inflammatory responses. Here, we evaluated the anti-inflammatory role of LXA(4), during the acute phase of zymosan-induced arthritis, focusing on the modulation of ET-1 expression and its effects. EXPERIMENTAL APPROACH The anti-inflammatory effects of LXA(4), BML-111 (agonist of FPR2/ALX receptors) and acetylsalicylic acid (ASA) pre- and post-treatments were investigated in a murine model of zymosan-induced arthritis. Articular inflammation was assessed by examining knee joint oedema; neutrophil accumulation in synovial cavities; and levels of prepro-ET-1 mRNA, leukotriene (LT)B(4), tumour necrosis factor (TNF)-alpha and the chemokine KC/CXCL1, after stimulation. The direct effect of LXA(4) on ET-1-induced neutrophil activation and chemotaxis was evaluated by shape change and Boyden chamber assays respectively. KEY RESULTS LXA(4), BML-111 and ASA administered as pre- or post-treatment inhibited oedema and neutrophil influx induced by zymosan stimulation. Zymosan-induced preproET-1 mRNA, KC/CXCL1, LTB(4) and TNF-alpha levels were also decreased after LXA(4) pretreatment. In vitro, ET-1-induced neutrophil chemotaxis was inhibited by LXA4 pretreatment. LXA(4) treatment also inhibited ET-1-induced oedema formation and neutrophil influx into mouse knee joints. CONCLUSION AND IMPLICATION LXA(4) exerted anti-inflammatory effects on articular inflammation through a mechanism that involved the inhibition of ET-1 expression and its effects.

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Melanocortin system and corticotropin releasing hormone (CRH) are implicated in the control of feeding behavior. Besides its anorexigenic effect on food intake, CRH is one of the most important regulators of hypothalamic-pituitary-adrenal (HPA) axis activity. Therefore, there could be an interplay between HPA axis activity and melanocortin system. We investigated the expression of melanocortin-4 receptor (MC4-R) mRNA in the hypothalamus of rats after 14 days of food restriction or after a fasting-refeeding regimen, in sham or adrenalectomized rats. Male Wistar rats were subjected to free access to food or food ingestion restricted for 2 h a day (8-10 AM) during 14d, when plasma corticosterone, ACTH, insulin, leptin concentrations, and MC4-R mRNA expression were determined before and after refeeding. Another set of rats was fasted for 48 h, followed by refeeding during 2 or 4 h on the seventh day after adrenalectomy (ADX) or sham surgery. On the day of the experiment, rats were anesthetized and perfused and the brain processed for MC4-R mRNA by in situ hybridization. Long-term reduction of food intake, either secondary to food restriction or adrenalectomy, reduced body weight gain and also leptin and insulin plasma concentrations. Food ingestion reduced MC4-R expression in the paraventricular nucleus in naive rats subjected to food restriction and also in sham rats fasted for 48 h. However, after ADX, MC4-R expression was not changed by refeeding. In conclusion, the present data indicate that MC4-R expression is downregulated by food ingestion and this response could be modulated by glucocorticoid withdrawal.

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Huntington`s disease-like 2 (HDL2) is a neurodegenerative disorder found in people of African ancestry with clinical, radiological, and neuropathological manifestations similar to Huntington`s disease (HD). HDL2 is caused by a pathological expansion of CAG/CTG triplets in exon 2A of the JPH3 gene. We describe four cases of HDL2 from four unrelated families, and discuss their clinical findings. HDL2 should be considered in every patient with an HD-like phenotype who tests negative for the HD mutation, even if African ancestry is not immediately apparent. (C) 2008 Movement Disorder Society