879 resultados para mediators


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Recent research advances in understanding the cellular and molecular mechanisms that underlie the processes of hypertrophy and atrophy. This may contribute to development of effective therapeutic strategies to attenuate or block the loss of muscle tissue associated with aging and pathological conditions. In this context, myogenic factors that control the activity of satellite cells have been studied to better understand the events involved in the recovery of muscle mass. Among them, we highlight the Myogenic Regulatory Factors (MRFs), which have been described as potential mediators of muscle growth. The objectives of this study evaluated the morphofunctional adaptations and gene expression of MRFs (MyoD and myogenin) in skeletal muscle (soleus) subjected to an atrophic stimulus followed by physical training. It was used 64 male Wistar rats (80 days, 250 to 300 g), divided into 8 groups (n = 8): C: control animals a week, I: Animals immobilized a week, C3: control animals 3 days; R3: Animals immobilized and recovered for 3 days, T3: Animals immobilized and submitted to exercise for 3 days; C7: Animals controls 7 days; R7: Animals immobilized and subsequently recovered by 7 days, T7: Animals immobilized and subsequently subjected to exercise for 7 days. Initially, the animals in groups I, R3, R7, T3 and T7, were submitted to 7 days of immobilization of the hind limb. Muscle atrophy was confirmed after a direct statistical comparison of the values of cross-sectional area (CSA) of muscle fibers studied in animals in groups I and C, sacrificed immediately after the immobilization period. Then, the groups T3 and T7 were submitted a rehabilitation program with muscle aerobic exercise (swimming) for 3 and 7 days respectively. The groups C, C3 and C7 were kept without stimulus atrophic and were not subjected to exercise. At the end of the experiment, the animals were sacrified and the soleus muscle removed. The quantitative analysis of gene expression ...

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Osteoarticular diseases are very frequent in small animals, especially dogs. Osteoarthritis is the most common degenerative arthropathy in cats and dogs. It is one of the most important skeletal disease in small animals and it is divided into two broad classes: secondary and genetics. The secondary is originated from situations that can cause joint instability like as trauma, ligament problems and obesity among others. The gene for osteoarthritis comes from hereditary problems such as hip dysplasia, elbow dysplasia and other diseases that can cause articular instability. The hereditary osteoarticular diseases are important only because they can result in the osteoarthritis. It is important to prevent the joint instability and consequently the clinical signs that affect the quality of life of the animals. The most common clinical signs are intermittent claudication, a decrease in performance, reluctance to jump and climb ladders among others. To prevent the clinical signs or mitigate them, the treatments need to be focused on pain control and especially restoration of the affected joint. The treatments most used are the medical and surgery. Anti-inflammatory and analgesics are used in large scale for pain control and to inhibit inflammatory mediators. Furthermore, medical treatment includes weight reduction, physiotherapy and proper nutrition along with anti-inflammatory and analgesics. Surgical treatments are indicated if there is an inadequate response to medical treatment. Physiotherapy is often used in conjunction with other treatments. Besides the reduction of weight is essential and obesity is unacceptable. Cats also suffer from osteoarthritis, but the diagnosis is rarer than in dogs. Usually the cat’s owners relate the reluctance to jump and drop in performance with senility, and when the disease is diagnosed is already in... (Complete abstract click electronic access below)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Sickle cell anemia (SCA) shows a pathophysiology that involves multiple changes in sickle cell erythrocytes, vaso-occlusive episodes, hemolysis, activation of inflammatory mediators, endothelial cell dysfunction, and oxidative stress. These events complicate treatment and culminate in the development of manifestations such as anemia, pain crises and multiorgan dysfunction. The aim of this study was to evaluate, in SCA patients, oxidative stress and antioxidant capacity markers, correlating them to treatment with hydroxyurea (HU), β-globin haplotypes and glutathione S-transferase polymorphisms (GSTT1, GSTM1 and GSTP1), in comparison to a control group (CG). The study groups were composed of 48 individuals without hemoglobinopathies (CG), SCA patients treated with HU [AF (+HU), N = 13] and untreated SCA patients [AF (-HU), N = 15], after informed consent. The groups were analyzed using cytological, electrophoretic, chromatographic and molecular methods and information from medical records. The GSTM1 and GSTT1 polymorphisms were determined by multiplex PCR, while the GSTP1 polymorphism by PCR-RFLP. Biochemical parameters were measured using spectrophotometric methods [TBARS, TEAC and catalase (CAT) and GST activities] and a chromatographic method [glutathione (GSH)]. The fetal Hb (Hb F) levels observed in the SCA (+HU) group (10.9%) confirmed the already well-described pharmacological effect of HU, but the SCA (-HU) group also had high Hb F levels (6.1%), which may have been influenced by genetic factors not targeted in this study. We found a higher frequency of the Bantu haplotype (48.2%), followed by the Benin (32.1%) and also Cameroon haplotypes, rare in our population, and 19.7% of atypical haplotypes. The presence of Bantu haplotype was related to higher lipid peroxidation levels in patients, but also, it conferred a differential response to HU treatment, raising Hb F levels in 52.6% (P = 0.03). The protective effect of Hb F was confirmed, because the increase in their levels resulted in a 41.3% decrease in lipid peroxidation levels (r = -0.74, P = 0.0156). The genotypic frequency of the GST polymorphisms observed was similar to that of other studies in the Brazilian population, and its association with biochemical markers revealed a significant difference only for the GSTP1 polymorphism, where patients with genotype V/V showed higher GSH and TEAC levels (P = 0.04 and P = 0.03, respectively) compared to patients with genotype I/I. The TBARS levels were about five to eight times higher in the SCA (+HU) and SCA (-HU) groups, respectively, compared to controls, and HU produced a 35.2% decrease in lipid peroxidation levels in the SCA (+HU) group (P < 0.0001). Moreover, the SCA (+HU) group showed higher TEAC levels when compared to CG (P = 0.002). We did not find any significant difference in GST activity between the groups studied (P = 0.76), but CAT activity was about 17 and 30% lower in SCA (+HU) and SCA (-HU) groups, respectively (P < 0.00001). Plasma GSH levels were ~2 times higher in SCA patients than in the control group (P = 0.0005) and showed a positive correlation with TBARS levels, confirming its antioxidant function. HU treatment contributed to higher CAT activity and TEAC levels and lower lipid peroxidation, and its pharmacological effect showed a “haplotype-dependent” response. These findings may contribute to elucidating the potential of HU in ameliorating oxidative stress in SCA subjects.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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In the present paper, it is presented a general view about who they are and the activities science centers and museums mediators develop. The literature points out to the diverse roles attributed to these actors and that the presence of this type of professional is a consolidated practice in non-formal educational institutions. Data obtained among the mediators of a science center during mediated school visits are also presented and discussed, focusing in the role attributed to these professionals, with the objective of characterizing their actions during these visits. The data obtained and analyzed showed that during school visits, the roles that are attributed to the mediators are: (a) mediation of the knowledge involved in the expositions; (b) explanation of the scientific concepts involved in the expositions; (c) presentation of the thematic spaces; (d) reception and organization of groups of visitors; (e) preservation of the physical and moral integrity of the visitors, and the integrity of the physical spaces and their equipments; (f) complementation of the school knowledge, and (g) diffusion of the scientific knowledge.

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Aim To assess the initial cytotoxicity and the late phenotype marker expression of odontoblast-like cells (MDPC-23) subjected to less aggressive in-office bleaching therapies. Methodology A 17.5% hydrogen peroxide (H2O2) gel was applied for 45, 15 or 5 min to enamel/dentine discs adapted to trans-wells positioned over cultured MDPC-23 cells. No treatment was performed on the negative control. Immediately after bleaching, the cell viability, gene expression of inflammatory mediators and quantification of H2O2 diffusion were evaluated. The ALP activity, DSPP and DMP-1 gene expression and mineralized nodule deposition (MND) were assessed at 7, 14 or 21 days post-bleaching and analysed statistically with Mann–Whitney U-tests (α = 5%). Results H2O2 diffusion, proportional to treatment time, was observed in all bleached groups. Reductions of approximately 31%, 21% and 13% in cell viability were observed for the 45-, 15- and 5-min groups, respectively. This reduction was significant (P < 0.05) for the 45- and 15-min groups, which also presented significant (P < 0.05) over-expression of inflammatory mediators. The 45-min group was associated with significant (P < 0.05) reductions in DMP-1/DSPP expression at all periods, relative to control. The ALP activity and MND were reduced only in initial periods. The 15-min group had less intense reduction of all markers, with no difference to control at 21 days. Conclusions The 17.5% H2O2 applied to tooth specimens for 5 min caused no alteration in the odontoblast-like cells. When this gel was applied for 45 or 15 min, a slight cytotoxicity, associated with alterations in phenotypic markers, was observed. However, cells were able to recover their functions up to 21 days post-bleaching.

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Resident, non-immune cells express various pattern-recognition receptors and produce inflammatory cytokines in response to microbial antigens, during the innate immune response. Alveolar bone resorption is the hallmark of destructive periodontitis and it is caused by the host response to bacteria and their mediators present on the biofilm. The balance between the expression levels of receptor activator of nuclear factorkappa B ligand (RANKL) and osteoprotegerin (OPG) is pivotal for osteoclast differentiation and activity and has been implicated in the progression of bone loss in periodontitis. To assess the contribution of resident cells to the bone resorption mediated by innate immune signaling, we stimulated fibroblasts and osteoblastic cells with LPS from. Escherichia coli (TLR4 agonist), Porphyromonas gingivalis (TLR2 and -4 agonist), and interleukin-1 beta (as a control for cytokine signaling through Toll/IL-1receptor domain) in time-response experiments. Expression of RANKL and OPG mRNA was studied by RT-PCR, whereas the production of RANKL protein and the activation of p38 MAPK and NF-kB signaling pathways were analyzed by western blot. We used biochemical inhibitors to assess the relative contribution of p38 MAPK and NF-kB signaling to the expression of RANKL and OPG induced by TLR2, -4 and IL1β in these cells. Both p38 MAPK and NFkB pathways were activated by these stimuli in fibroblasts and osteoblasts, but the kinetics of this activation varied in each cell type and with the nature of the stimulation. E. coli LPS was a stronger inducer of RANKL mRNA in fibroblasts, whereas LPS from P. gingivalis downregulated RANKL mRNA in periodontal ligament cells but increased its expression in osteoblasts. IL-1β induced RANKL in both cell types and without a marked effect on OPG expression. p38 MAPK was more relevant than NF-kB for the expression of RANKL and OPG in these cell types.

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Periodontitis is an infectious disease characterized by the secretion of a variety of inflammatory mediators that lead to destruction of tooth supporting tissues, including the possible loss of alveolar bone, in association with infection with multiple species of bacteria. It is estimated that more than 400 species colonize the biofilm and some oral species related to periodontal disease is present in the subgingival including P. gingivalis, T. forsythia and T. denticola. However, other organisms may be related of this disease, as Filifactor allocis and Prevotella tannerae. These microorganisms and subproducts such as endotoxins released into the extracellular lead to the stimulation of metalloproteinase inducer glycoprotein (EMMPRIN, CD-147), which stimulates the release of MMPs by host cells, like fibroblasts and endothelial cells, thus leading to tissue destruction. The objective of this study was to detect F. allocis, P. tannerae, T. denticola and the glycoprotein EMMPRIN (CD-147) and its correlation with MMP-2 and MMP-9 in subgingival fluid samples of patients with chronic periodontitis. Fluids were collected from healthy and disease subgingival sites of 20 healthy individuals before basic periodontal treatment and after of 60 days of treatment. Their DNAs were extracted and portions of the 16S gene were amplified and performed conventional PCR. For immunological analysis and quantification of EMMPRIN (CD-147), MMP-2 and MMP-9 was used ELISA-Sandwich. Results demonstrated that the disease group showed significantly high amounts of T. denticola, F. alocis and P. tannerae when compared with health sites. MMP-2 and MMP-9 were detected in high concentrations with statistically significantly reduction after periodontal treatment to MMP-2, but without correlation with EMMPRIN.

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Objectives: The human antimicrobial peptide cathelicidin (LL-37) possesses anti-inflammatory properties that may contribute to attenuating the inflammatory process associated with chronic periodontitis. Plant polyphenols, including those from cranberry and green tea, have been reported to reduce inflammatory cytokine secretion by host cells. In the present study, we hypothesized that A-type cranberry proanthocyanidins (AC-PACs) and green tea epigallocatechin-3-gallate (EGCG) act in synergy with LL-37 to reduce the secretion of inflammatory mediators by oral mucosal cells. Methods: A three-dimensional (3D) co-culture model of gingival epithelial cells and fibroblasts treated with non-cytotoxic concentrations of AC-PACs (25 and 50 mg/ml), EGCG (1 and 5 mg/ml), and LL-37 (0.1 and 0.2 mM) individually and in combination (AC-PACs + LL-37 and EGCG + LL-37) were stimulated with Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS). Multiplex ELISA assays were used to quantify the secretion of 54 host factors, including chemokines, cytokines, growth factors, matrix metalloproteinases (MMPs), and tissue inhibitors of metalloproteinases (TIMPs). Results: LL-37, AC-PACs, and EGCG, individually or in combination, had no effect on the regulation of MMP and TIMP secretion but inhibited the secretion of several cytokines. ACPACs and LL-37 acted in synergy to reduce the secretion of CXC-chemokine ligand 1 (GRO-a), granulocyte colony-stimulating factor (G-CSF), and interleukin-6 (IL-6), and had an additive effect on reducing the secretion of interleukin-8 (IL-8), interferon-g inducible protein 10 (IP-10), and monocyte chemoattractant protein-1 (MCP-1) in response to LPS stimulation. EGCG and LL-37 acted in synergy to reduce the secretion of GRO-a, G-CSF, IL-6, IL-8, and IP-10, and had an additive effect on MCP-1 secretion. Conclusion: The combination of LL-37 and natural polyphenols from cranberry and green tea acted in synergy to reduce the secretion of several cytokines by an LPS-stimulated 3D coculture model of oral mucosal cells. Such combinations show promising results as potential adjunctive therapies for treating inflammatory periodontitis.

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The association between platelets, angiogenesis and progression or repair of periodontal disease has been little explored and, consequently, the results are inconclusive. The pathogenic bacteria present in the periodontal pocket release endotoxins that affect the endothelial integrity and are able to induce the production of chemical mediators derived from plasma proteins and blood clotting while altering platelet function. There is great interest in the modulation of platelet activity in vascular disorders, especially cardiovascular diseases. For this reason, antiplatelet drugs, that are commonly used in the prevention of thromboembolic diseases, such as myocardial infarction, ischemic stroke and peripheral arterial disease, have been used. Aspirin is the only non-steroidal antiinflammatory agent with antiplatelet activity. In the periodontium, instead of only reduces levels of inflammatory cytokines, also significantly affects bleeding on probing, suggesting a dose-dependent modulation of periodontitis. In contrast, clopidogrel and ticlopidine are thienopyridine drugs with no known antiinflammatory action, suggesting that this benefit is related to an antiinflammatory effect indirectly correlated to their antiplatelet activity already established. In the literature there is limited information about the effect of these drugs on periodontium and periodontal disease development. Antiplatelet drugs hypothetically can change both the pathogenesis of periodontitis and subsequent periodontal tissue repair by blocking the secretion of chemical mediators which in general are important in modulating inflammation and tissue repair.

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Hospitalization is usually steeped in fantasies that generate high levels of anxiety, especially for children. Therefore, the hospital psychotherapeutic process must propose actions to enable them to develop internal resources to cope with situation that causes anxiety. This article aims to demonstrate the importance of psychological intervention through drawings as mediators in the pre-surgical context of orthopedic correction in the hospital. This patient made seven drawings that at first expressed her anguish towards the surgery and at the end showed her attempt to elaborate. We conclude that drawing is an important therapeutic tool in the hospital.

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Purpose: Angiogenesis involves many mediators including integrins, and the tripeptide RGD is a target amino acid recognition sequence for many of them. Hindlimb ischemia is a simple and convenient animal model however standardization of the injection procedures in the devascularized and control limb is lacking, thus rendering difficult the interpretation of results. The aim of this investigations was to evaluate neovascularization in a hindlimb murine model by means of 99mTc-HYNIC-ß-Ala-RGD. Methods: 99mTc-HYNIC-RGD analog was prepared using coligands. Ischemia was induced in Wistar rats by double- ligation of the common femoral artery. Radiolabeled RGD was injected after 2h, as well as 1, 3, 5, 7, 10 and 14 days. Uptake was evaluated by planar imaging and biodistribution studies. Results: The highest ratio between ischemia and control was achieved at the 7th day (2.62 ± 0.95), with substantial decrease by the 14th day. For pertechnetate the 7th day ratio was 0.87 ± 0.23. Scintigraphic image confirmed different uptakes. Conclusion: 99mTc-HYNIC-RGD analog concentrated in ischemic tissue by the time of widespread angiogenesis and pertechnetate confirmed reduction in blood flow. In this sense, the protocol can be recommended for ischemic models.