997 resultados para antigen binding


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Nuclear fluorescence in keratinocytes is an occasional phenomenon, often present in autoimmune diseases, especially in connective-tissue disease (CTD); however, its clinical significance remains unclear. To investigate the profile of patients with positive nuclear staining on direct immunofluorescence (DIF) of skin samples. A retrospective analysis of 28 patient records from our immunodermatology laboratory was performed between May 2003 and June 2006. Inclusion criteria were the presence of autoantibodies (IgG, IgA or IgM) or complement (C3) binding keratinocyte nuclei on DIF. The most prevalent diseases related to the nuclear keratinocyte DIF staining were systemic lupus erythematosus (n = 9), mixed CTD (n = 3), overlap syndrome (n = 3), Sjogren`s syndrome (n = 1), and CREST (calcinosis, Raynaud`s phenomenon, oesophageal dysmotility, sclerodactyly and telangiectasia) syndrome (n = 1). Serum antinuclear antibody (ANA) was positive in 20 of 28 patients, with titres varying from 1 : 160 to 1 : 1280. Of the 20 patients with positive anti-nuclear antibodies (ANA), 17 were positive for anti-extractable nuclear antigen antibodies, 12 had anti-SSA/Ro, 11 had anti-SSB/La and 8 had anti-ribonucleoprotein. Eight patients were negative for ANA. Positive predictive value of in vivo ANA for systemic CTDs was 75%. The present data suggest that in vivo ANA evaluation is an additional and feasible auxiliary tool for diagnosing CTDs.

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Sustained virologic suppression is a primary goal of therapy for chronic hepatitis B (CHB). In study entecavir (ETV)-022, 48 weeks of entecavir 0.5 mg was superior to lamivudine for virologic suppression for hepatitis B e antigen (HBeAg)-positive CHB. A total of 183 entecavir-treated patients from ETV-022 subsequently enrolled in study ETV-901. We present the results after up to 5 years (240 weeks) of continuous entecavir therapy. The entecavir long-term cohort consists of patients who received >= 1 year of entecavir 0.5 mg in ETV-022 and then entered ETV-901 with a treatment gap <= 35 days. In ETV-901 the entecavir dose was 1.0 mg daily. For patients with samples available at Year 5, proportions with hepatitis B virus (HBV) DNA <300 copies/mL, normal alanine aminotransferase (ALT) levels, HBeAg loss, and HBeAg seroconversion were determined. In all, 146 patients met criteria for inclusion in the entecavir long-term cohort. At Year 5, 94% (88/94) had HBV DNA <300 copies/mL and 80% (78/98) had normal ALT levels. In addition to patients who achieved serologic responses during study ETV-022, 23% (33/141) achieved HBeAg seroconversion and 1.4% (2/145) lost hepatitis B surface antigen (HBsAg) during study ETV-901. Through 5 years, entecavir resistance emerged in one patient. The safety profile of entecavir was consistent with previous reports. Conclusion: Extended therapy with entecavir through 5 years maintained or increased rates of HBV DNA suppression and ALT normalization. Additional patients also achieved HBeAg loss and seroconversion. Entecavir provides sustained viral suppression with minimal resistance during long-term treatment of HBeAg-positive CHB. (HEPATOLOGY 2010;51:422-430.)

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PURPOSE: Carcinoembriogenic antigen (CEA) is the most frequently used tumor marker in rectal cancer. A decrease in carcinoembriogenic antigen after radical surgery is associated with survival in these patients. Neoadjuvant chemoradiotherapy may lead to significant primary tumor downstaging, including complete tumor regression in selected patients. Therefore, we hypothesized that a decrease in CEA after neoadjuvant chemoradiotherapy could reflect tumor response to chemoradiotherapy, affecting final disease stage and ultimately survival. METHODS: Patients with distal rectal cancer managed by neoadjuvant chemoradiotherapy and available pretreatment and postchemoradiotherapy levels of CEA were eligible for the study. Outcomes studied included final disease stage, relapse, and survival, and these were compared according to initial CEA level, postchemoradiotherapy CEA level, and the reduction in CEA. RESULTS: Overall 170 patients were included. Postchemoradiotherapy CEA levels < 5 ng/ml were associated with increased rates of complete clinical response and pathologic response. Additionally, postchemoradiotherapy CEA levels < 5 ng/ml were associated with increased overall and disease-free survival (P = 0.01 and P = 0.03). There was no correlation between initial CEA level or reduction in CEA and complete response or survival. CONCLUSION: A postchemoradiotherapy CEA level < 5 ng/ml is a favorable prognostic factor for rectal cancer and is associated with increased rates of earlier disease staging and complete tumor regression. Postchemoradiotherapy CEA levels may be useful in decision making for patients who may be candidates for alterative treatment strategies.

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Egr-1 and related proteins are inducible transcription factors within the brain recognizing the same consensus DNA sequence. Three Egr DNA-binding activities were observed in regions of the naive rat brain. Egr-1 was present in all brain regions examined. Bands composed, at least in part, of Egr-2 and Egr-3 were present in different relative amounts in the cerebral cortex, striatum, hippocampus, thalamus, and midbrain. All had similar affinity and specificity for the Egr consensus DNA recognition sequence. Administration of the convulsants NMDA, kainate, and pentylenetetrazole differentially induced Egr-1 and Egr-2/3 DNA-binding activities in the cerebral cortex, hippocampus, and cerebellum. All convulsants induced Egr-1 and Egr-2 immunoreactivity in the cerebral cortex and hippocampus. These data indicate that the members of the Egr family are regulated at different levels and may interact at promoters containing the Egr consensus sequence to fine tune a program of gene expression resulting from excitatory stimuli.

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Background: Versutoxin (delta-ACTX-Hv1) is the major component of the venom of the Australian Blue Mountains funnel web spider, Hadronyche versuta. delta-ACTX-Hv1 produces potentially fatal neurotoxic symptoms in primates by slowing the inactivation of voltage-gated sodium channels; delta-ACTX-Hv1 is therefore a useful tool for studying sodium channel function. We have determined the three-dimensional structure of delta ACTX-Hv1 as the first step towards understanding the molecular basis of its interaction with these channels. Results: The solution structure of delta-ACTX-Hv1, determined using NMR spectroscopy, comprises a core beta region containing a triple-stranded antiparallel beta sheet, a thumb-like extension protruding from the beta region and a C-terminal 3(10) helix that is appended to the beta domain by virtue of a disulphide bond. The beta region contains a cystine knot motif similar to that seen in other neurotoxic polypeptides. The structure shows homology with mu-agatoxin-l, a spider toxin that also modifies the inactivation kinetics of vertebrate voltage-gated sodium channels. More surprisingly, delta-ACTX-Hv1 shows both sequence and structural homology with gurmarin, a plant polypeptide. This similarity leads us to suggest that the sweet-taste suppression elicited by gurmarin may result from an interaction with one of the downstream ion channels involved in sweet-taste transduction. Conclusions: delta-ACTX-Hv1 shows no structural homology with either sea anemone or alpha-scorpion toxins, both of which also modify the inactivation kinetics of voltage-gated sodium channels by interacting with channel recognition site 3. However, we have shown that delta-ACTX-Hv1 contains charged residues that are topologically related to those implicated in the binding of sea anemone and alpha-scorpion toxins to mammalian voltage-gated sodium channels, suggesting similarities in their mode of interaction with these channels.

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Cancer/testis Antigens (CTAs) are immunogenic proteins with a restricted expression pattern in normal tissues and aberrant expression in different types of tumors being considered promising candidates for immunotherapy. We used the alignment between EST sequences and the human genome sequence to identify novel CT genes. By examining the EST tissue composition of known CT clusters we defined parameters for the selection of 1184 EST clusters corresponding to putative CT genes. The expression pattern of 70 CT gene candidates was evaluated by RT-PCR in 21 normal tissues, 17 tumor cell lines and 160 primary tumors. We were able to identify 4 CT genes expressed in different types of tumors. The presence of antibodies against the protein encoded by 1 of these 4 CT genes (FAM46D) was exclusively detected in plasma samples from cancer patients. Due to its restricted expression pattern and immunogenicity FAM46D represents a novel target for cancer immunotherapy. (c) 2009 Elsevier Inc. All rights reserved.

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Our data suggest that serum concentrations of insulin-like growth factor I and insulin-like growth factor binding protein 3 do not correlate with breast cancer development. (Fertil Steril (R) 2011;95:2753-5. (C)2011 by American Society for Reproductive Medicine.)

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Follistatin is an activin-binding protein produced by several tissues, including endometrium and endometriotic implants. We aimed to quantify follistatin in patients with ovarian endometriosis and investigate its value as a diagnostic marker. Women undergoing laparoscopic excision of ovarian endometrioma (n = 52) or other benign ovarian cysts (n = 52) were studied, plus women with non-ovarian endometriosis (n = 11) and healthy controls (n = 27). Serum was collected from all subjects, and peritoneal and cystic fluid from a subset with endometrioma. Follistatin was measured by enzyme-linked immunosorbent assay. The diagnostic accuracy of follistatin to detect endometrioma was evaluated by receiver operating characteristic (ROC) curve and compared with cancer antigen (CA)-125. Serum follistatin was increased in women with ovarian endometrioma (2080 +/- 94 pg/ml) compared with controls (545 +/- 49 pg/ml, P < 0.001), other benign ovarian cysts (795 +/- 60 pg/ml, P < 0.001) or non-ovarian endometriosis (1271 +/- 115 pg/ml, P < 0.001). Cystic fluid showed a higher concentration of follistatin (9850 +/- 4461 pg/ml) than peritoneal fluid (1885 +/- 261 pg/ml, P < 0.001) and serum (P < 0.001). Follistatin levels detected 48/52 cases of endometrioma (92% sensitivity) at 1433 pg/ml cut-off, corresponding to 92% specificity. CA-125 detected only 44% of endometriomas with 90% specificity. ROC curve comparison showed follistatin was more accurate than CA-125 to discriminate women with endometrioma either from controls or women with other benign ovarian cysts (P < 0.0001). Serum follistatin is increased in women with endometriosis and allows clear distinction between endometrioma and other benign ovarian cysts. Follistatin has the sensitivity and specificity to become a useful clinical marker of ovarian endometrioma.

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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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The present study aimed to evaluate the effects of immunization with soluble amastigote (AmaAg) and promastigote (ProAg) antigens from Leishmania (Viannia) shawi on the course of infection in BALB/c mice. After immunization with AmaAg, the challenged group showed greater lesion size and parasite load in the skin and lymph nodes, associated with diminished interleukin (IL)-2, IL-4, IL-10, interferon (IFN)-gamma and nitrate levels in the supernatant of lymph node cell cultures, together with increases in transforming growth factor (TGF)-beta concentrations and humoral immune response. In contrast, immunization with ProAg led to smaller lesion size with reduced numbers of viable parasites in the skin. Protection was associated with increases in IL-12, IFN-gamma, TGF-beta and nitrates and decreases in IL-4 and IL-10 levels. Concerning humoral immune response, a significant reduction in anti-leishmania immunoglobulin G was verified in the ProAg-challenged group. Analysis of these results suggests that AmaAg induced a suppressive cellular immune response in mice, favouring the spread of infection, whereas ProAg induced partial protection associated with increased cellular immune response.

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A flow cytometry-adapted fluorescent antibody to membrane antigen (FAMA) assay to detect IgG antibodies against varicella-zoster virus (VZV) was developed and tested in 62 serum samples, showing 90.32% accuracy obtained from a receiver operating characteristic (ROC) curve with a 0.9125 (95% confidence interval [CI], 0.829 to 1.00) area below the curve compared to the result with standard FAMA.

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The objective of this study was to verify the possible association between the Sp1-binding site polymorphism and genital prolapse. A case-control study was conducted in 107 patients with stages III and IV genital prolapse. The control group included 209 women with stages 0 and I. The polymorphism of type I collagen Sp1-binding site was identified by amplification of the first intron of the COL1A1 gene. We did not find differences in the prevalence of the GT and TT genotypes between the groups (p=0.34), even when we grouped patients with at least one polymorphic allele (GT and TT) and compared them with patients without the polymorphic allele (GG; p=0.17) The presence of at least one vaginal delivery, family history for prolapse, and macrosomatic fetus were independent risk factors for prolapse. In conclusion, the COL1A1 Sp1-binding site was not significantly associated with genital prolapse among our study subjects.