538 resultados para Vítor Alves
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Annexin A1 (ANXA1) is a soluble cytoplasmic protein, moving to membranes when calcium levels are elevated. ANXA1 has also been shown to move to the nucleus or outside the cells, depending on tyrosine-kinase signalling, thus interfering in cytoskeletal organization and cell differentiation, mostly in inflammatory and neoplastic processes. The aim was to investigate subcellular patterns of immunohistochemical expression of ANXA1 in neoplastic and non-neoplastic samples from patients with laryngeal squamous cell carcinomas (LSCC), to elucidate the role of ANXA1 in laryngeal carcinogenesis. Serial analysis of gene expression experiments detected reduced expression of ANXA1 gene in LSCC compared with the corresponding non-neoplastic margins. Quantitative polymerase chain reaction confirmed ANXA1 low expression in 15 LSCC and eight matched normal samples. Thus, we investigated subcellular patterns of immunohistochemical expression of ANXA1 in 241 paraffin-embedded samples from 95 patients with LSCC. The results showed ANXA1 down-regulation in dysplastic, tumourous and metastatic lesions and provided evidence for the progressive migration of ANXA1 from the nucleus towards the membrane during laryngeal tumorigenesis. ANXA1 dysregulation was observed early in laryngeal carcinogenesis, in intra-epithelial neoplasms; it was not found related to prognostic parameters, such as nodal metastases.
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Background/Aims: Hepatocellular carcinoma (HCC) is a well recognized complication of advanced NASH (non-alcoholic steatohepatitis). We sought to produce a rat model of NASH, cirrhosis and HCC. Methods: Adult Sprague-Dawley rats, weighing 250-300 g, were fed a choline-deficient, high trans-fat diet and exposed to DEN in drinking water. After 16 weeks, the animals underwent liver ultrasound (US), sacrifice and assessment by microscopy, immunohistochemistry and transmission electron microscopy (TEM). Results: US revealed steatosis and focal lesions in 6 of 7. All had steatohepatitis defined as inflammation, advanced fibrosis and ballooning with Mallory-Denk bodies (MDB) with frank cirrhosis in 6. Areas of more severe injury were associated with anti-CK19 positive ductular reaction. HCC, present in all, were macro-trabecullar or solid with polyhedral cells with foci of steatosis and ballooned cells. CK19 was positive in single or solid nests of oval cells and in neoplastic hepatocytes. TEM showed ballooning with small droplet fat, dilated endoplasmic reticulum and MDB in non-neoplastic hepatocytes and small droplet steatosis in some cancer cells. Conclusions: This model replicated many features of NASH including steatohepatitis with ballooning, fibrosis, cirrhosis and hepatocellular carcinoma. Oval cell proliferation was evident and the presence anti-CK 19 positivity in the cancer suggests oval cell origin of the malignancy. (C) 2008 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
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Objective: We correlated dietary profile and markers of visceral and somatic obesities in nonalcoholic fatty liver disease. Methods: Patients with histologically proven fatty infiltration of the liver (n = 25, 52 +/- 11 y of age, 64% women) underwent abdominal computed tomography, bioelectrical impedance, and anthropometric measurements. Insulin resistance was evaluated (homeostasis model assessment) and dietary intake of macronutrients was estimated by 24-h recall. Main outcome measurements were correlation of carbohydrate and fat ingestion with liver histology. Results: Metabolic syndrome was present in 72% of the population, and increased waist circumference and low high-density lipoprotein cholesterol occurred in 66%. Total body fat (bioimpedance) and dietary intake of lipids were higher in patients with non-alcoholic steatohepatitis (P < 0.05), but not in diabetic subjects who exhibited more steatosis than non-alcoholic steatohepatitis. Waist circumference exhibited a good correlation with homeostasis model assessment, total energy intake, and ingestion of specific fatty acids. Body mass index correlated well with somatic and visceral adiposities. Conclusion: Energy intake and visceral adiposity were predisposing factors for fatty liver disease. Lipid input correlated with non-alcoholic steatohepatitis in the entire group and after stratification for diabetes. These findings suggest that lipid intake may play a greater role in non-alcoholic steatohepatitis than hitherto suspected. (C) 2008 Elsevier Inc. All rights reserved.
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Context: The expression of sodium iodide symporter (NIS) is required for iodide uptake in thyroid cells. Benign and malignant thyroid tumors have low iodide uptake. However, previous studies by RT-PCR or immunohistochemistry have shown divergent results of NIS expression in these nodules. Objective: The objective of the study was to investigate NIS mRNA transcript levels, compare with NIS and TSH receptor proteins expression, and localize the NIS protein in thyroid nodules samples and their surrounding nonnodular tissues (controls). Design: NIS mRNA levels, quantified by real-time RT-PCR, and NIS and TSH receptor proteins, evaluated by immunohistochemistry, were examined in surgical specimens of 12 benign and 13 malignant nodules and control samples. Results: When compared with controls, 83.3% of the benign and 100% of the malignant nodules had significantly lower NIS gene expression. Conversely, 66.7% of the benign and 100% of malignant nodules had stronger intracellular NIS immunostaining than controls. Low gene expression associated with strong intracellular immunostaining was most frequently detected in malignant (100%) than benign nodules (50%; P = 0.005). NIS protein was located at the basolateral membrane in 24% of the control samples, 8.3% of the benign, and 15.4% of the malignant nodules. The percentage of benign nodules with strong TSH receptor positivity (41.6%) was higher than malignant (7.7%). Conclusion: We confirmed that reduced NIS mRNA expression in thyroid malignant nodules is associated with strong intracellular protein staining and may be related to the inability of the NIS protein to migrate to the cellular basolateral membrane. These results may explain the low iodide uptake of malignant nodules.
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The aim of this study was to evaluate the effect of the pulsed ultrasound therapy (PUT) in stimulating myoregeneration and collagen deposition in an experimental model of lacerative gastrocnemius muscle lesion in 30 Wistar rats. Fifteen rats were treated (TG) daily with 1 MHz pulsed ultrasound (50%) at 0.57 W/cm(2) for 5 min, and 15 were control animals (CG). Muscle samples were analyzed on postoperative days 4, 7 and 14 through H&E, Picrosirius-polarization and immunohistochemistry for desmin. The lesions presented similar inflammatory responses in both treated and control groups. The areal fraction of fibrillar collagen was larger in the TG at 4 days post-operatively (17.53 +/- 6.2% vs 6.79 +/- 1.3%, p = 0.0491), 7 days (31.07 +/- 7.45% vs 12.57 +/- 3.6%, p = 0.0021) and 14 days (30.39 +/- 7.3% vs 19.13 +/- 3.51%, p = 0.0118); the areal fraction of myoblasts and myotubes was larger in the TG at 14 days after surgery (41.66 +/- 2.97% vs 34.83 +/- 3.08%, p = 0.025). Our data suggest that the PUT increases the differentiation of muscular lineage cells, what would favor tissue regeneration. On the other hand, it is also suggested that there is a larger deposition of collagenous fibers, what could mean worse functional performance. However, the percentage of fibers seems to have stabilized at day 7 in TG and kept increasing in CG. Furthermore, the collagen supramolecular organization achieved by the TG is also significant according to the Sirius red staining results. (C) 2008 Elsevier B.V. All rights reserved.
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Objective: To evaluate the effectiveness of acupuncture for fibromyalgia. Methods: Fifty-eight women with fibromyalgia were allocated randomly to receive either acupuncture together with tricyclic antidepressants and exercise (n = 34), or tricyclic antidepressants and exercise only (n=24). Patients rated their pain on a visual analogue scale. A blinded assessor evaluated both the mean pressure pain threshold value over all 18 fibromyalgia points and quality of life using SF-36. Results: At the end of 20 sessions, patients who received acupuncture were significantly better than the control group in all measures of pain and in 5 of the SF-36 subscales. After 6 months, the acupuncture group was significantly better than the control group in numbers of tender points, mean pressure pain threshold at the 18 tender points and 3 subscales of SF-36. After one year, the acupuncture group showed significance in one subscale of the SF-36; at 2 years there were no significant differences in any outcome measures. Conclusion: Addition of acupuncture to usual treatments for fibromyalgia may be beneficial for pain and quality of life for 3 months after the end of treatment. Future research is needed to evaluate the specific effects of acupuncture for fibromyalgia.
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Introduction: The mechanisms by which severe cholestatic hepatitis develops after liver transplantation are not fully understood. Reports on immunohistochemical distribution of hepatitis C virus (HCV) antigens are still scarce, but recently, HCV immunostaining was suggested for early diagnosis of cholestatic forms of recurrent hepatitis C in liver grafts. After purification, Rb246 pab anticore (aa1-68) yielded specific, granular cytoplasmic staining in hepatocytes. Signal amplification through the Envision-Alkaline Phosphatase System avoided endogenous biotin and peroxidase. Aims/Methods: Rb246 was applied to liver samples of explants of 12 transplant recipients, six with the most severe form of post-transplantation recurrence, severe cholestatic hepatitis (group 1) and six with mild recurrence (group 2). We also assessed immuno-reactivity at two time-points post-transplantation (median 4 and 22 months) in both groups. HCV-core Ag was semiquantified from 0 to 3+ in each time point. Serum HCV-RNA was also measured on the different time points by branched DNA. Results: In the early post-transplant time point, one patient had a mild staining (1+), two patients had a moderate staining (2+) and the other three had no staining in group 1, compared with five patients with no staining (0) and one patient with mild staining (1+) in group 2. Late post-transplant liver samples were available in nine patients, and two out of four samples in group 1 showed a mild staining, compared with no staining patients in five patients in group 2. Strikingly, on the explant samples, HCV immunostaining was strongly positive in group 1, and mildly positive in group 2. Two out of five samples showed 3+ staining, and three samples showed 2+ staining in group 1; two out of five samples showed no staining, two samples showed 1+ staining and one sample showed 2+ staining in group 2. Serum HCV-RNA was significantly higher in group 1, on both time-points post-transplantation. HCV-core Ag was not directly associated with serum HCV-RNA on the different time points. Conclusion: These preliminary results suggest that strong HCV immunostaining in the explant is predictive of more severe disease recurrence.
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Objective: To evaluate the role oral administration of S-nitroso-N-acetylcysteine (SNAC), a NO donor drug, in the prevention and reversion of NASH in two different animal models. Methods: NASH was induced in male ob/ob mice by methionine-choline deficient (MCD) and high-fat (H) diets. Two animal groups received or not SNAC orally for four weeks since the beginning of the treatment. Two other groups were submitted to MCD and H diets for 60 days receiving SNAC only from the 31(st) to the 60(th) day. Results: SNAC administration inhibited the development of NASH in all groups, leading to a marked decrease in macro and microvacuolar steatosis and in hepatic lipid peroxidation in the MCD group. SNAC treatment reversed the development of NASH in animals treated for 60 days with MCD or H diets, which received SNAC only from the 31(st) to the 60(th) day. Conclusions: Oral administration of SNAC markedly inhibited and reversed NASH induced by MCD and H diets in ob/ob mice.
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To evaluate whether lymphatic vessel density (LVD) and lymphatic vessel invasion (LVI) are useful markers of worse outcome in colorectal carcinoma and if LVD and LVI correlate to the classical clinical-pathological parameters, we analysed 120 cases of colorectal carcinomas selected from the files of Division of Pathology, Hospital das Clinicas, Sao Paulo University, Brazil. Assessment of LVD and LVI was performed by immunohistochemical detection of lymphatic vessels, using the monoclonal antibody D2-40. Higher LVD was found in the intratumoural area, when comparing with normal and peritumoural areas (p < 0.001). However, peritumoural LVD, but not intratumoural, correlated with both colonic-wall-invasion depth (p=0.037) and liver metastasis (p=0.012). Remarkably, LVI was found associated with local invasion (p=0.016), nodal metastasis (p=0.022) and hepatic metastasis (p < 0.001). Peritumoural LVD and LVI are directly related to histopathological variables indicative of poor outcome such as lymph-node status and liver metastasis.
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Tumour cells are known to be highly glycolytic, thus producing high amounts of lactic acid. Monocarboxylate transporters (MCTs), by promoting the efflux of the accumulating acids, constitute one of the most important mechanisms in the maintenance of tumour intracellular pH. Since data concerning MCT expression in colorectal carcinomas (CRC) are scarce and controversial, the present study aimed to assess the expressions of MCT1, 2, and 4 in a well characterized series of CRC and assess their role in CRC carcinogenesis. CRC samples (126 cases) were analyzed for MCT1, MCT2, and MCT4 immunoexpression and findings correlated with clinico-pathological parameters. Expression of all MCT isoforms in tumour cells was significantly increased when compared to adjacent normal epithelium. Remarkably, there was a significant gain of membrane expression for MCT1 and MCT4 and loss of plasma membrane expression for MCT2 in tumour cells. Plasma membrane expression of MCT1 was directly related to the presence of vascular invasion. This is the larger study on MCT expression in CRC and evaluates for the first time its clinico-pathological significance. The increased expression of these transporters suggests an important role in CRC, which might justify their use, especially MCT1 and MCT4, as targets in CRC drug therapy.
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This study was conducted to analyze the participation of tenascin and fibronectin, components of the extracellular matrix. in different types of carcinoma ex pleomorphic adenoma (CXPA). Seventeen cases of CXPA, classified according to the presence of epithelial and myoepithelial cells and the degree of invasion-intracapsular, minimally, and frankly invasive carcinoma-were immunohistochemically labeled for tenascin and fibronectin. Normal salivary gland included in the specimens showed tenascin only around the excretory duct, and fibronectin slightly expressed all over the stroma of the gland. In reminiscent pleomorphic adenoma, tenascin and fibronectin were observed around tubular structures and in the stroma. Both tenascin and fibronectin were expressed in all the CXPA studied. In areas of in situ carcinoma of the intracapsular type, the expression of these extracellular matrix proteins was enhanced compared with areas of residual pleomorphic adenoma. In intracapsular and minimally invasive types of CXPA, some areas of the tumor border presented tenascin and no fibronectin, pattern that may represent the real invasive front. In frankly invasive CXPA type with only epithelial component, fibronectin was strongly observed in a fibrillar network pattern, and tenascin was only focal. In frankly invasive type with myoepithelial component, tenascin staining was very strong and diffuse. This study showed different patterns of expression of tenascin and fibronectin along the process of tumorigenesis and tumor progression in CXPA, a fact that might play a role in invasion properties of these tumors.
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Vaccines capable of inducing mucosal immunity in early postnatal life until adulthood, protecting early sexual initiation, should be considered as strategies to vaccination against HIV. The HIV-1 GAG protein as a chimera with the lysosome-associated membrane protein (LAMP/gag), encoded by a DNA vaccine, is targeted to the endosomal/lysosomal compartment that contains class II MHC molecules and has been shown to be immunogenic in adult mice. Assuming that one such strategy could help to overcome the immunological immaturity in the early postnatal period, we have evaluated the systemic and mucosal immunogenicity of LAMP/gag immunization in neonatal mice. Intranasal immunization with LAMP/gag vaccine induced higher levels of sIgA and IgG anti-GAG antibodies in intestinal washes than did the gag vaccine. The combination of ID injections and the IN protocol with the chimeric vaccine promoted the increase of Ab levels in sera. Both vaccines induced splenic IFN-gamma- secreting cells against GAG peptide pools, as well as in vivo cytotoxic T lymphocyte (CTL) function, and increased the percentage of CD8+ T cells to the immunodominant class I peptide in gut and spleen. However, only the chimeric vaccine was able to enhance Th1/Th2 cytokine secretion in response to class II GAG peptide and to enhance IL-4-secreting cells against GAG peptides and p24 protein stimuli. Long-lasting humoral and cellular responses were detected until adult age, following neonatal immunization with the chimeric vaccine. The LAMP/gag vaccination was able to induce potent GAG-specific T and B cell immune responses in early life which are essential to elicit sustained and long-lasting mucosal and systemic humoral response. (C) 2010 Elsevier GmbH. All rights reserved.
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BACKGROUND: Among the various occupations which necessarily require long-term and chronic sun exposure is that of a fisherman. However, clinical experience in dermatology earned over several years of medical practice does not seem to confirm this hypothesis. OBJECTIVE: To evaluate clinical, histological and immunological effects of long-term and chronic exposure to ultraviolet radiation in fishermen. METHODS: A prospective, cross-sectional and observational study characterized skin lesions, immunological markers and histological alterations in fishermen, as well as lymphocyte subpopulations compared to a control group. Mann-Whitney, Fisher`s and Wilcoxon statistical tests were used at a significance level of 0.05. RESULTS: There were significant differences between the exposed group and the group protected due to elastosis (p = 0.03), ectasia of dermal vessels (p = 0.012) and number of cells in the epidermal layers between cones (p = 0.029). Most common among fishermen were CD45RO, CD68 + and mastocytes in the skin (p = 0.040, p < 0.001, p = 0.001) and CD3CD8CD45RO in the blood (p = 0.016). CONCLUSION: The alterations suggest that long-term and chronic sun exposure promotes tolerance to ultraviolet radiation, which protects against immunosuppression.
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Background/aim Regulation of apoptosis in non-alcoholic fatty liver disease (NAFLD) has been a theme of growing debate. Although no other study assessed the role of survivin in NAFLD, its expression has been reported in hepatic carcinogenesis because of other aetiological factors with relevant discrepancies. The aim of this study was to assess the pattern of survivin immunoexpression by tissue microarray along the whole spectrum of NAFLD, including non-alcoholic steatohepatitis (NASH)-related hepatocelular carcinoma (HCC). Methods Liver biopsies from 56 patients with NAFLD were evaluated: 18 with steatosis, 21 non-cirrhotic NASH, 10 NASH-related cirrhosis, seven NASH-related HCC, as compared with 71 HCC related to other causes and with 12 normal livers. Results Survivin immunoexpression in NAFLD was restricted to cytoplasm and was found to be progressively lower in advanced stages, including cirrhosis and HCC: steatosis vs NASH-related cirrhosis (P=0.0243); steatosis vs NASH-related HCC (P=0.0010); NASH vs NASH-related cirrhosis (P=0.0318); and NASH vs NASH-related HCC (P=0.0007), thus suggesting a deregulation of apoptosis from NAFLD towards HCC. Interestingly, survivin immunoreactivity in NASH-related HCC was also found to be significantly lower than in HCC related to other causes (P < 0.05). Remarkably, nuclear staining for survivin was not detected in any case of NAFLD, contrasting to its presence in all other cases of HCC. Conclusions Survivin immunoexpression in NASH-related HCC is herein originally found substantially different than in HCC related to other causes, thus requiring further studies to elucidate the role of survivin in human NAFLD progression.
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Objective: Superoxide dismutase-2 (SOD2) is considered one of the most important antioxidant enzymes that regulate cellular redox state in normal and tumorigenic cells. Overexpression of this enzyme may be involved in carcinogenesis, particularly in lung, gastric, colorectal and breast cancer. Methods: In the present study, we have evaluated SOD2 protein levels by immunohistochemistry (IHC) in 331 cervical histological samples including 31 low-grade cervical intraepithelial neoplasia (LSIL), 51 high-grade cervical intraepithelial neoplasia (HSIL), 197 squamous cervical carcinomas (SCC) and 52 cervical adenocarcinomas (ADENO). Results: We observed that SOD2 staining increases with cervical disease severity. Intense SOD2 staining was found in 13% of LSIL, 25.5% of HSIL and 40% of SCC. Moreover, 65.4% of ADENO exhibited intense SOD2 staining. Conclusions: Differences in the expression of SOD2 could potentially be used as a biomarker for the characterization of different stages of cervical disease.