929 resultados para Arthritis rheumatoid
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In this work, we investigated the effects of He-Ne laser irradiation on the inflammatory process induced in the articular cartilage of the right knee of guinea pigs. Through electron microscopy analysis it was possible to identify the induced arthritis in the articular cartilage and its modification after the laser treatment. The laser radiation promoted a reduction in the proliferation of the inflammatory cells in the damaged tissue and also induced the formation of cartilage bridges that tied the destroyed parts favoring the formation of a repaired tissue in the injured cartilage. (C) 2000 Elsevier B.V. B.V. All rights reserved.
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We described a prophylactic and therapeutic effect of a DNA vaccine encoding the Mycobacterium leprae 65- kDa heat shock protein (DNA-hsp65) in experimental murine tuberculosis. However, high homology of the vaccine to the corresponding mammalian hsp60, together with the CpG motifs in the plasmidial vector, could trigger or exacerbate an autoimmune disease. In the present study, we evaluate the potential of DNA- hsp65 vaccination to induce or modulate arthritis in mice genetically selected for acute inflammatory reaction (AIR), either maximal (AIRmax) or minimal (AIRmin). Mice immunized with DNA-hsp65 or injected with the corresponding DNA vector (DNAv) developed no arthritis, whereas pristane injection resulted in arthritis in 62% of AIRmax mice and 7.3% of AIRmin mice. Administered after pristane, DNA- hsp65 downregulated arthritis induction in AIRmax animals. Levels of interleukin (IL)- 12 were significantly lower in mice receiving pristane plus DNA- hsp65 or DNAv than in mice receiving pristane alone. However, when mice previously injected with pristane were inoculated with DNA- hsp65 or DNAv, the protective effect was significantly correlated with lower IL-6 and IL-12 levels and higher IL-10 levels. Our results strongly suggest that DNA-hsp65 has no arthritogenic potential and is actually protective against experimentally induced arthritis in mice.
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Matrix metalloprotease-13 (MMP-13) or collagenase-3 is involved in a number of pathologic processes such as tumor metastasis and angiogenesis, osteoarthritis, rheumatoid arthritis and periodontal diseases. These conditions are associated with extensive degradation of both connective tissue and bone. This report examines gene regulation mechanisms and signal transduction pathways involved in Mmp-13 expression induced by proinflammatory cytokines in periodontal ligament (PDL) fibroblasts. Mmp-13 mRNA expression was increased 10.7 and 9.5 fold after stimulation with IL-1 beta (5 ng/mL) and TNF-alpha (10 ng/mL), respectively. However, inhibition of p38 MAPKinase with SB203580 resulted in significant (p < 0.001) induction (23.2 and 18.1 fold, respectively) of Mmp-13 mRNA as assessed by real time PCR. Negative regulation of IL-1 induced Mmp-13 expression was confirmed by inhibiting p38 MAPK gene expression with siRNA. Transient transfection of dominant negative forms of MKK3 and MKK6 also resulted in increased levels of Mmp-13 mRNA after IL-1 beta stimulation. Mmp-13 mRNA expression induced by TNF-alpha was decreased by JNK and ERK inhibition. Western blot and zymogram analysis indicated that Mmp-13 protein expression induced by the proinflammatory cytokines were also upregulated by inhibition of p38 MAPK. Reporter gene experiments using stable cell lines harboring 660-bp sequence of the murine Mmp-13 proximal promoter indicated that transcriptional mechanisms were at least partially involved in this negative regulation of Mmp-13 expression by p38 MAPK and upstream MKK3/6. These results suggest a negative transcriptional regulatory mechanism mediated by p38 MAPK and upstream MKK3/6 on Mmp-13 expression induced by proinflammatory cytokines in PDL fibroblasts. (c) 2005 Elsevier B.V./International Society of Matrix Biology. All rights reserved.
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Objective. To investigate the proxy-reported health-related quality of life (HRQOL) and its determinants in patients with juvenile idiopathic arthritis (JIA).Methods. In this multinational, multicenter, cross-sectional study, HRQOL of patients with JIA was assessed through the Child Health Questionnaire (CHQ) and was compared with that of healthy children of similar age from the same geographic area. of joint inflammation, Childhood Health Assessment Questionnaire (CHAQ), and erythrocyte sedimentation rate.Results. A total of 6,639 participants (3,324 with JIA and 3,315 healthy) were enrolled from 32 countries. The mean SD physical and psychosocial summary scores of the CHQ were significantly lower in patients with JIA than in healthy children (physical: 44.5 +/- 10.6 versus 54.6 +/- 4.0, P < 0.0001; psychosocial: 47.6 +/- 8.7 versus 51.9 +/- 7.59 P < 0.0001), with the physical well-being domain being most impaired. Patients with persistent oligoarthritis had better HRQOL compared with other subtypes, whereas HRQOL was similar across patients with systemic arthritis, polyarthritis, and extended oligoarthritis. A CHAQ score > 1 and a pain intensity rating > 3.4 cm on a 10-cm visual analog scale were the strongest determinants of poorer HRQOL in the physical and psychosocial domains, respectively.Conclusion. We found that patients with JIA have a significant impairment of their HRQOL compared with healthy peers, particularly in the physical domain. Physical well-being was mostly affected by the level of functional impairment, whereas the intensity of pain had the greatest influence on psychosocial health.
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Matrix metal loprotease-13 (MMP-13) is induced by pro-inflammatory cytokines and increased expression is associated with a number of pathological conditions such as tumor metastasis, osteoarthritis, rheumatoid arthritis and periodontal diseases. MMP-13 gene regulation and the signal transduction pathways activated in response to bacterial LPS are largely unknown. In these studies, the role of the mitogen-activated protein kinase (MAPK) pathways in the regulation of MMP-13 induced by lipopolysaccharide was investigated. Lipopolysaccharide from Escherichia coli and Actinobacillus actinomycetemcomitans significantly (P < 0.05) increased MMP-13 steady-state mRNA (average of 27% and 46% increase, respectively) in murine periodontal ligament fibroblasts. MMP-13 mRNA induction was significantly reduced by inhibition of p38 MAP kinase. Immunoblot analysis indicated that p38 signaling was required for LPS-induced MMP-13 expression. Lipopolysaccharide induced proximal promoter reporter (-660/+32 mMMP-13) gene activity required p38 signaling. Collectively, these results indicate that lipopolysaccharide-induced murine MMP-13 is regulated by p38 signaling through a transcriptional mechanism.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Background Some children with juvenile idiopathic arthritis either do not respond, or are intolerant to, treatment with disease-modifying antirheumatic drugs, including anti-tumour necrosis factor (TNF) drugs. We aimed to assess the safety and efficacy of abatacept, a selective T-cell costimulation modulator, in children with juvenile idiopathic arthritis who had failed previous treatments.Methods We did a double-blind, randomised controlled withdrawal trial between February, 2004, and June, 2006. We enrolled 190 patients aged 6-17 years, from 45 centres, who had a history of active juvenile idiopathic arthritis; at least five active joints; and an inadequate response to, or intolerance to, at least one disease-modifying antirheumatic drug. All 190 patients were given 10 mg/kg of abatacept intravenously in the open-label period of 4 months. of the 170 patients who completed this lead-in course, 47 did not respond to the treatment according to predefined American College of Rheumatology (ACR) paediatric criteria and were excluded. of the patients who did respond to abatacept, arthritis, and 62 were randomly assigned to receive placebo at the same dose and timing. The primary endpoint was time to flare of arthritis. Flare was defined as worsening of 30% or more in at least three of six core variables, with at least 30% improvement in no more than one variable. We analysed all patients who were treated as per protocol. This trial is registered, number NCT00095173.Findings Flares of arthritis occurred in 33 of 62 (53%) patients who were given placebo and 12 of 60 (20%) abatacept patients during the double-blind treatment (p=0.0003). Median time to flare of arthritis was 6 months for patients given placebo (insufficient events to calculate IQR); insufficient events had occurred in the abatacept group for median time to flare to be assessed (p=0.0002). The risk of flare in patients who contined abatacept was less than a third of that for controls during that double-blind period (hazard ratio 0.31, 95% CI 0.16-0.95). During the double-blind period, the frequency of adverse events did not differ in the two treatment groups, Adverse events were recorded in 37 abatacept recipients (62%) and 34 (55%) placebo recipients (p=0.47); only two serious adverse events were reported, bouth in controls (p=0.50).Interpretation Selective modulation of T-cell costimulation with abatacept is a rational alternative treatment for children with juvenile idiopathic arthritis.Funding Bristol-Myers Squibb.
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We report the cross-cultural adaptation and validation into Brazilian-Portuguese of the parent's version of two health related quality of life instruments. The Childhood Health Assessment Questionnaire (CHAQ) is a disease specific health instrument that measures functional ability in daily living activities in children with juvenile idiopathic arthritis (JIA). The Child Health Questionnaire (CHQ) is a generic health instrument designed to capture the physical and psychosocial well-being of children regardless the underlying disease. The Brazilian CHAQ was revalidated, while the CHQ has been derived from the Portuguese version. A total of 471 subjects were enrolled: 157 patients with JIA (27% systemic onset, 38% polyarticular onset, 9% extended oligoarticular subtype, and 26% persistent oligoarticular subtype) and 314 healthy children. The CHAQ discriminated clinically healthy subjects from JIA patients, with the systemic, polyarticular and extended oligoarticular subtypes having a higher degree of disability, pain, and lower overall well-being scores when compared to their healthy peers. Also the CHQ discriminated clinically healthy subjects from JIA patients, with the systemic onset, polyarticular onset and extended oligoarticular subtypes having a lower physical and psychosocial well-being score when compared to their healthy peers. In conclusion the Brazilian versions of the CHAQ-CHQ are reliable and valid tools for the combined physical and psychosocial assessment of children with JIA. © Copyright Clinical and Experimental Rheumatology 2001.
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Purine nucleoside phosphorylase (PNP) catalyzes the phosphorolysis of the N-ribosidic bonds of purine nucleosides and deoxynucleosides. A genetic deficiency due to mutations in the gene encoding for human PNP causes T-cell deficiency as the major physiological defect. Inappropriate activation of T-cells has been implicated in several clinically relevant human conditions such as transplant tissue rejection, psoriasis, rheumatoid arthritis, lupus, and T-cell lymphomas. Human PNP is therefore a target for inhibitor development aiming at T-cell immune response modulation. In addition, bacterial PNP has been used as reactant in a fast and sensitive spectrophotometric method that allows both quantitation of inorganic phosphate (Pi) and continuous assay of reactions that generate P i such as those catalyzed by ATPases and GTPases. Human PNP may therefore be an important biotechnological tool for P i detection. However, low expression of human PNP in bacterial hosts, protein purification protocols involving many steps, and low protein yields represent technical obstacles to be overcome if human PNP is to be used in either high-throughput drug screening or as a reagent in an affordable P i detection method. Here, we describe PCR amplification of human PNP from a liver cDNA library, cloning, expression in Escherichia coli host, purification, and activity measurement of homogeneous enzyme. Human PNP represented approximately 42% of total soluble cell proteins with no induction being necessary to express the target protein. Enzyme activity measurements demonstrated a 707-fold increase in specific activity of cloned human PNP as compared to control. Purification of cloned human PNP was achieved by a two-step purification protocol, yielding 48 mg homogeneous enzyme from 1 L cell culture, with a specific activity value of 80 U mg -1. © 2002 Elsevier Science (USA). All rights reserved.
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Living cells are continuously exposed to a variety of challenges that exert oxidative stress and are directly related with senescence and the onset of various pathological conditions such as coronary heart disease, rheumatoid arthritis and cancer. Nevertheless, living organisms have developed a complex antioxidant network to counteract reactive species that are detrimental to life. With the aim of bio-prospecting plant species from the Brazilian Cerrado and Atlantic Forest, we have established a methodology to detect secondary antioxidant metabolites in crude extracts and fractions obtained from plant species. Combining HPLC with an electrochemical detector allowed us to detect micromolecules that showed antioxidant activities in Chimarrhis turbinata (DC) leaf extracts. Comparison with purified flavonoid standards led us to identify the compounds in their natural matrices giving valuable information on their antioxidant capacity.
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Objective: to study the impact of chronic arthritis on health related quality of life by means of two self-reported tools: the parents' version of the Childhood Health Assessment Questionnaire (CHAQ) and the Childhood Health Questionnaire PF50® (CHQ). Methods: both tools were filled in after proper instructions by 36 parents, during 1-2 clinic visits. The Disability Index (CHAQ) and the Physical and Psychosocial scores (CHQ) were compared to the core set of outcome measures, namely 1) physician's global assessment, 2) parents' global assessment, both scored by 10 cm visual analogue scale, 3) number of joints with active arthritis, 4) number of joints with limited range of motion, 5) erythrocyte sedimentation rate. Results: there was significant difference for all measures of disease activity, being higher in the polyarticular as compared to oligoarticular except for erythrocyte sedimentation rate, parents' global assessment, and psychosocial score. This leads to different parents' perceptions of disease activity and outcome. The responsiveness of the outcome measures during two follow-up visits of patients receiving active treatment indicated better responsiveness of physicians' global assessment among the subjective measures, and intermediate responsiveness of the self-reported measures in comparison to the number of active and limited joints, and erythrocyte sedimentation rate. Conclusions: the responsiveness of two health related quality of life tools indicates their relative sensitivity for assessing clinical improvement during active treatment in Juvenile Idiopathic Arthritis patients. Copyright © 2003 by Sociedade Brasileira de Pediatria.
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The background of prodrug design is presented herein as the basis for introducing new and advanced latent systems, taking into account mainly the versatility of polymers and other macromolecules as carriers. PDEPT (Polymer-Directed Enzyme Prodrug Therapy); PELT (Polymer-Enzyme Liposome Therapy); CDS (Chemical Delivery System); ADEPT(Antibody-Directed Enzyme Prodrug Therapy); GDEPT/VDEPT (Gene-Directed Enzyme Prodrug Therapy/Virus-Directed Enzyme Prodrug Therapy); ODDS (Osteotropic Drug Delivery System) and LEAPT (Lectin-directed enzyme-activated prodrug therapy) are briefly described and some examples are given. © 2005 Bentham Science Publishers Ltd.
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The risk for venous thromboembolism (VTE) in medical patients is high, but risk assessment is rarely performed because there is not yet a good method to identify candidates for prophylaxis. Purpose: To perform a systematic review about VTE risk factors (RFs) in hospitalized medical patients and generate recommendations (RECs) for prophylaxis that can be implemented into practice. Data sources: A multidisciplinary group of experts from 12 Brazilian Medical Societies searched MEDLINE, Cochrane, and LILACS. Study selection: Two experts independently classified the evidence for each RF by its scientific quality in a standardized manner. A risk-assessment algorithm was created based on the results of the review. Data synthesis: Several VTE RFs have enough evidence to support RECs for prophylaxis in hospitalized medical patients (eg, increasing age, heart failure, and stroke). Other factors are considered adjuncts of risk (eg, varices, obesity, and infections). According to the algorithm, hospitalized medical patients ≥40 years-old with decreased mobility, and ≥1 RFs should receive chemoprophylaxis with heparin, provided they don't have contraindications. High prophylactic doses of unfractionated heparin or low-molecular-weight-heparin must be administered and maintained for 6-14 days. Conclusions: A multidisciplinary group generated evidence-based RECs and an easy-to-use algorithm to facilitate VTE prophylaxis in medical patients. © 2007 Rocha et al, publisher and licensee Dove Medical Press Ltd.