996 resultados para ANTIGEN LEVEL


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To determine the intra-individual (physiological) variation of prostate-specific antigen (PSA) measurements in men after a benign prostatic biopsy. Sixty-four men were prospectively assessed, all of whom had a benign prostatic biopsy within the preceding 13 months. The degree of intra-individual variability was established by calculating the coefficient of variation on four PSA levels obtained from each patient weekly over a month. Six patients were subsequently diagnosed with prostate cancer and their data are presented separately. In the remaining 58 patients the median (range) individual mean PSA value was 6.3 (0.5-34.1) ng/mL. The median (range) coefficient of variation within the group was 9.5 (2.4-76.1)%. There was a clear linear relationship between mean PSA level and the standard deviation. In 48 of the 63 patients analysed, the coefficient of variation for serum PSA values in the group as a whole was greater than the variation claimed for the assay technique. The significance of the linear relationship between PSA and the standard deviation is discussed, with particular reference to those men who had a benign prostate biopsy.

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Nitric oxide synthase (NOS) inhibitors are largely used to evaluate the NO contribution to pulmonary allergy, but contrasting data have been reported. In this study, pharmacological, biochemical and pharmacokinetic assays were performed to compare the effects of acute and long-term treatment of BALB/C mice with the non-selective NOS inhibitor L-NAME in ovalbumin (OVA)-challenged mice. Acute L-NAME treatment (50 mg/kg, gavage) significantly reduced the eosinophil number in bronchoalveolar lavage fluid (BALF). The inducible NOS (iNOS) inhibitor aminoguanidine (20 mg/kg/day in the drinking water) also significantly reduced the eosinophil number in BALF In contrast, 3-week L-NAME treatment (50 and 150 mg/kg/day in the drinking water) significantly increased the pulmonary eosinophil influx. The constitutive NOS (cNOS) activity in brain and lungs was reduced by both acute and 3-week L-NAME treatments. The pulmonary iNOS activity was reduced by acute L-NAME (or aminoguanidine), but unaffected by 3-week L-NAME treatment. Acute L-NAME (or aminoguanidine) treatment was more efficient to reduce the NO(x) levels compared with 3-week L-NAME treatment. The pharmacokinetic study revealed that L-NAME is not bioavailable when given orally. After acute L-NAME intake, serum concentrations of the metabolite N(omega)-nitro-L-arginine decreased from 30 min to 24 h. In the 3-week L-NAME treatment, the N(omega)-nitro-L-arginine concentration was close to the detection limit. In conclusion, 3-week treatment with L-NAME yields low serum N(omega)-nitro-L-arginine concentrations, causing preferential inhibition of cNOS activity. Therefore, eosinophil influx potentiation by 3-week L-NAME treatment may reflect removal of protective cNOS-derived NO, with no interference on the ongoing inflammation due to iNOS-derived NO. (c) 2008 Elsevier Ltd. All rights reserved.

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O presente trabalho estudou um ensaio imunoenzimático (ELISA) indireto para a detecção de anticorpos anti-Babesia canis no soro de cães, tendo a Reação de Imunofluorescência Indireta (RIFI), como teste de referência O antígeno utilizado no ELISA do presente estudo consistiu em uma preparação antigênica solúvel de merozoítas B. canis e as diluições ótimas do antígeno, soros e conjugado foram determinadas por titulação em bloco, utilizando soros de referência positivos e negativos. A preparação antigênica solúvel de B. canis ótima foi de 10 µg.mL-1, com soros de referência positivos e negativos em uma única diluição de 1:100, e conjugado a 1:4.000. Um total de 246 amostras séricas foram colhidas em cães, durante a campanha de vacinação anti-rábica em Jaboticabal, São Paulo, Brasil e a presença de anticorpos anti-B. canis foi avaliada pelo ELISA e RIFI. Nestas condições, a média de absorbância dos soros de referência negativos foi de 0,129 ± 0,025, resultando em um ponto de corte de 0,323 (Nível de ELISA 3) e a média da absorbância dos soros de referência positivos foi de 2,156 ± 1,187. As amostras com sorologia positiva para B. canis por ELISA e RIFI foram 67,89% (n = 167) e 59,35% (n = 146), respectivamente. Os resultados obtidos sugerem que o ELISA descrito revelou-se um teste sorológico eficaz no diagnóstico da babesiose canina.

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C. Larralde et al. (1990, Arch. Pathol. Lab. Med., 114:926-928) demonstrated that heterologous antigen from the laboratory-adapted murine Taenia crassiceps metacestode may substitute those from Taenia solium in the immunodiagnosis of human cysticercosis by the indirect enzyme-linked immunosorbent assay (IE). ?This antigen is easily obtained at a laboratory level and solves the problem of T. solium cysticerci collection from naturally or experimentally infected swine. In this study an IE employing a heterologous antigen from the T. crassiceps metacestode was evaluated for the immunodiagnosis of swine cysticercosis. Sera from 300 swine free of T. solium cysticerci by post-mortem examination were employed to determine two IE cut- off values: 1) Mean ELISA values + 2 standard deviations (2 sigma cut-off) and 2) - Mean ELISA values + 3 standard deviations (3 sigma cut-off). The specificity of IE was 97% with the 2 sigma cut-off and 100% with the 3 sigma cut-off. When applied to ten sera from swine infected by cysticerci of T. solium by post-mortem examination, the sensitivity of IE was 100% independent of the cut off.

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This study evaluated the influence of bone marrow aspirate (BMA), low-level laser therapy (LLLT) and their combination on bone healing in surgically created critical-size defects (CSDs) in rat calvaria. 40 rats were divided into four groups: C (control), BMA, LLLT and BMA/LLLT. A 5 mm diameter CSD was created in the calvarium of each animal. In Group C, the defect was filled by blood clot only. In Group BMA, the defect was filled with BMA. In groups LLLT and BMA/LLLT, the defect received laser irradiation (InGaAlP laser), was filled with blood clot or BMA respectively, and irradiated again. Animals were euthanized 30 days postoperatively. Histomorphometric and immunohistochemical analyses were performed. Newly formed bone area (NFBA) was calculated as percentage of the total area of the original defect. Proliferating cell nuclear antigen (PCNA), runt-related transcription factor 2 (Runx2) and osteocalcin (OCN) immunohistochemical staining were performed. PCNA-positive, Runx2-positive and OCN-positive cells were quantified. Data were statistically analyzed. Group BMA/LLLT had significantly greater NFBA than groups C, BMA or LLLT. Group BMA presented significantly greater NFBA than control, while group LLLT did not. Group BMA/LLLT presented a significantly higher number of PCNA-positive and OCN-positive cells than any of the other groups. Groups BMA/LLLT and BMA showed a significantly lower number of Runx2-positive cells than groups C or LLLT. The combination of BMA/LLLT yielded significantly greater bone formation in surgically created CSD in rat calvaria when compared to control, or either treatment alone. © 2013 Elsevier B.V. All rights reserved.

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

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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In the last several years, the use of dendritic cells has been studied as a therapeutic strategy against tumors. Dendritic cells can be pulsed with peptides or full-length protein, or they can be transfected with DNA or RNA. However, comparative studies suggest that transfecting dendritic cells with messenger RNA (mRNA) is superior to other antigen-loading techniques in generating immunocompetent dendritic cells. In the present study, we evaluated a new therapeutic strategy to fight tuberculosis using dendritic cells and macrophages transfected with Hsp65 mRNA. First, we demonstrated that antigen-presenting cells transfected with Hsp65 mRNA exhibit a higher level of expression of co-stimulatory molecules, suggesting that Hsp65 mRNA has immunostimulatory properties. We also demonstrated that spleen cells obtained from animals immunized with mock and Hsp65 mRNA-transfected dendritic cells were able to generate a mixed Th1/Th2 response with production not only of IFN-γ but also of IL-5 and IL-10. In contrast, cells recovered from mice immunized with Hsp65 mRNA-transfected macrophages were able to produce only IL-5. When mice were infected with Mycobacterium tuberculosis and treated with antigen-presenting cells transfected with Hsp65 mRNA (therapeutic immunization), we did not detect any decrease in the lung bacterial load or any preservation of the lung parenchyma, indicating the inability of transfected cells to confer curative effects against tuberculosis. In spite of the lack of therapeutic efficacy, this study reports for the first time the use of antigen-presenting cells transfected with mRNA in experimental tuberculosis.

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Human endogenous retroviruses (HERVs) arise from ancient infections of the host germline cells by exogenous retroviruses, constituting 8% of the human genome. Elevated level of envelope transcripts from HERVs-W has been detected in CSF, plasma and brain tissues from patients with Multiple Sclerosis (MS), most of them from Xq22.3, 15q21.3, and 6q21 chromosomes. However, since the locus Xq22.3 (ERVWE2) lack the 5' LTR promoter and the putative protein should be truncated due to a stop codon, we investigated the ERVWE2 genomic loci from 84 individuals, including MS patients with active HERV-W expression detected in PBMC. In addition, an automated search for promoter sequences in 20 kb nearby region of ERVWE2 reference sequence was performed. Several putative binding sites for cellular cofactors and enhancers were found, suggesting that transcription may occur via alternative promoters. However, ERVWE2 DNA sequencing of MS and healthy individuals revealed that all of them harbor a stop codon at site 39, undermining the expression of a full-length protein. Finally, since plaque formation in central nervous system (CNS) of MS patients is attributed to immunological mechanisms triggered by autoimmune attack against myelin, we also investigated the level of similarity between envelope protein and myelin oligodendrocyte glycoprotein (MOG). Comparison of the MOG to the envelope identified five retroviral regions similar to the Ig-like domain of MOG. Interestingly, one of them includes T and B cell epitopes, capable to induce T effector functions and circulating Abs in rats. In sum, although no DNA substitutions that would link ERVWE2 to the MS pathogeny was found, the similarity between the envelope protein to MOG extends the idea that ERVEW2 may be involved on the immunopathogenesis of MS, maybe facilitating the MOG recognizing by the immune system. Although awaiting experimental evidences, the data presented here may expand the scope of the endogenous retroviruses involvement on MS pathogenesis

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Insect bite hypersensitivity (IBH) is an IgE-mediated seasonal dermatitis of the horses associated with bites of Simulium (black fly) and Culicoides (midge) species. Although cross-reactivity between Simulium and Culicoides salivary gland extracts has been demonstrated, the molecular nature of the allergens responsible for the observed cross-reactivity remains to be elucidated. In this report we demonstrate for the first time in veterinary medicine that a homologous allergen, present in the salivary glands of both insects, shows extended IgE cross-reactivity in vitro and in vivo. The cDNA sequences coding for both antigen 5 like allergens termed Sim v 1 and Cul n 1 were amplified by PCR, subcloned in high level expression vectors, and produced as [His](6)-tagged proteins in Escherichia coli. The highly pure recombinant proteins were used to investigate the prevalence of sensitization in IBH-affected horses by ELISA and their cross-reactive nature by Western blot analyses, inhibition ELISA and intradermal skin tests (IDT). The prevalence of sensitization to Sim v 1 and Cul n 1 among 48 IBH-affected horses was 37% and 35%, respectively. In contrast, serum IgE levels to both allergens in 24 unaffected horses did not show any value above background. Both proteins strongly bound serum IgE from IBH-affected horses in Western blot analyses, demonstrating the allergenic nature of the recombinant proteins. Extended inhibition ELISA experiments clearly showed that Sim v 1 in fluid phase is able to strongly inhibit binding of serum IgE to solid phase coated Cul n 1 in a concentration dependent manner and vice versa. This crucial experiment shows that the allergens share common IgE-binding epitopes. IDT with Sim v 1 and Cul n 1 showed clear immediate and late phase reactions to the allergen challenges IBH-affected horses, whereas unaffected control horses do not develop relevant immediate hypersensitivity reactions. In some horses, however, mild late phase reactions were observed 4h post-challenge, a phenomenon reported to occur also in challenge experiments with Simulium and Culicoides crude extracts probably related to lipopolysaccaride contaminations which are also present in E. coli-expressed recombinant proteins. In conclusion our data demonstrate that IgE-mediated cross-reactivity to homologous allergens, a well-known clinically relevant phenomenon in human allergy, also occurs in veterinary allergy.

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Anti-sperm antibodies (ASA) have been described to be involved in immunological infertility. A possible antigen for ASA is the human cysteine-rich secretory protein 2 (CRISP-2), a sperm surface protein important in sperm-oocyte interaction. Furthermore, anti-CRISP-2 antibodies were shown to decrease fertility rates in vitro. Recently, we have reported cross-reacting antibodies recognizing CRISP-2 and antigen 5 from yellow jacket venom (Ves v 5) in human serum.

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The major route of transmission of Neospora caninum in cattle is transplacentally from an infected cow to its progeny. Therefore, a vaccine should be able to prevent both the horizontal transmission from contaminated food or water and the vertical transmission. We have previously shown that a chimeric vaccine composed of predicted immunogenic epitopes of NcMIC3, NcMIC1 and NcROP2 (recNcMIC3-1-R) significantly reduced the cerebral infection in BALB/c mice. In this study, mice were first vaccinated, then mated and pregnant mice were challenged with 2×10(6)N. caninum tachyzoites at day 7-9 of pregnancy. Partial protection was only observed in the mice vaccinated with a tachyzoite crude protein extract but no protection against vertical transmission or cerebral infection in the dams was observed in the group vaccinated with recNcMIC3-1-R. Serological and cytokine analysis showed an overall lower cytokine level in sera associated with a dominant IL-4 expression and high IgG1 titers. Thus, the Th2-type immune response observed in the pregnant mice was not protective against experimental neosporosis, in contrary to the mixed Th1-/Th2-type immune response observed in the non-pregnant mouse model. These results demonstrate that the immunomodulation that occurs during pregnancy was not favorable for the protection against N. caninum infection conferred by vaccination with recNcMIC3-1-R.

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BACKGROUND: The deletion of three adjacent nucleotides in an exon may cause the lack of a single amino acid, while the protein sequence remains otherwise unchanged. Only one such in-frame deletion is known in the two RH genes, represented by the RHCE allele ceBP expressing a "very weak e antigen." STUDY DESIGN AND METHODS: Blood donor samples were recognized because of discrepant results of D phenotyping. Six samples came from Switzerland and one from Northern Germany. The molecular structures were determined by genomic DNA nucleotide sequencing of RHD. RESULTS: Two different variant D antigens were explained by RHD alleles harboring one in-frame triplet deletion each. Both single-amino-acid deletions led to partial D phenotypes with weak D antigen expression. Because of their D category V-like phenotypes, the RHD(Arg229del) allele was dubbed DVL-1 and the RHD(Lys235del) allele DVL-2. These in-frame triplet deletions are located in GAGAA or GAAGA repeats of the RHD exon 5. CONCLUSION: Partial D may be caused by a single-amino-acid deletion in RhD. The altered RhD protein segments in DVL types are adjacent to the extracellular loop 4, which constitutes one of the most immunogenic parts of the D antigen. These RhD protein segments are also altered in all DV, which may explain the similarity in phenotype. At the nucleotide level, the triplet deletions may have resulted from replication slippage. A total of nine amino acid positions in an Rhesus protein may be affected by this mechanism.

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OX7 monoclonal antibody F((ab')2) fragments directed against Thy1.1 antigen can be used for drug targeting by coupling to the surface of drug-loaded liposomes. Such OX7-conjugated immunoliposomes (OX7-IL) were used recently for drug delivery to rat glomerular mesangial cells, which are characterized by a high level of Thy1.1 antigen expression. In the present study, the relationship between OX7-IL tissue distribution and target Thy1.1 antigen localization in different organs in rat was investigated. Western blot and immunohistofluorescence analysis revealed a very high Thy1.1 expression in brain cortex and striatum, thymus and renal glomeruli. Moderate Thy1.1 levels were observed in the collecting ducts of kidney, lung tissue and spleen. Thy1.1 was not detected in liver and heart. There was a poor correlation between Thy1.1 expression levels and organ distribution of fluorescence- or (14)C-labeled OX7-IL. The highest overall organ density of OX7-IL was observed in the spleen, followed by lung, liver and kidney. Heart and brain remained negative. With respect to intra-organ distribution, a localized and distinct signal was observed in renal glomerular mesangial cells only. As a consequence, acute pharmacological (i.e. toxic) effects of doxorubicin-loaded OX7-IL were limited to renal glomeruli. The competition with unbound OX7 monoclonal antibody F((ab')2) fragments demonstrated that the observed tissue distribution and acute pharmacological effects of OX7-IL were mediated specifically by the conjugated OX7 antibody. It is concluded that both the high target antigen density and the absence of endothelial barriers are needed to allow for tissue-specific accumulation and pharmacological effects of OX7-IL. The liposomal drug delivery strategy used is therefore specific toward renal glomeruli and can be expected to reduce the risk of unwanted side effects in other tissues.

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Many hepatitis C virus (HCV) infections worldwide are with the genotype 1 and 3 strains of the virus. Cellular immune responses are known to be important in the containment of HCV genotype 1 infection, and many genotype 1 T cell targets (epitopes) that are presented by host human leukocyte antigens (HLAs) have been identified. In contrast, there is almost no information known about the equivalent responses to genotype 3. Immune escape mechanisms used by HCV include the evolution of viral polymorphisms (adaptations) that abrogate this host-viral interaction. Evidence of HCV adaptation to HLA-restricted immune pressure on HCV can be observed at the population level as viral polymorphisms associated with specific HLA types. To evaluate the escape patterns of HCV genotypes 1 and 3, we assessed the associations between viral polymorphisms and specific HLA types from 187 individuals with genotype 1a and 136 individuals with genotype 3a infection. We identified 51 HLA-associated viral polymorphisms (32 for genotype 1a and 19 for genotype 3a). Of these putative viral adaptation sites, six fell within previously published epitopes. Only two HLA-associated viral polymorphisms were common to both genotypes. In the remaining sites with HLA-associated polymorphisms, there was either complete conservation or no significant HLA association with viral polymorphism in the alternative genotype. This study also highlights the diverse mechanisms by which viral evasion of immune responses may be achieved and the role of genotype variation in these processes. CONCLUSION: There is little overlap in HLA-associated polymorphisms in the nonstructural proteins of HCV for the two genotypes, implying differences in the cellular immune pressures acting on these viruses and different escape profiles. These findings have implications for future therapeutic strategies to combat HCV infection, including vaccine design.