399 resultados para human source


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Oligodendrogliomas are the second most common malignant brain tumor in adults and exhibit characteristic losses of chromosomes 1p and 19q. To identify the molecular genetic basis for this alteration, we performed exomic sequencing of seven tumors. Among other changes, we found that the CIC gene (homolog of the Drosophila gene capicua) on chromosome 19q was somatically mutated in six cases and that the FUBP1 gene [encoding far-upstream element (FUSE) binding protein] on chromosome 1p was somatically mutated in two tumors. Examination of 27 additional oligodendrogliomas revealed 12 and 3 more tumors with mutations of CIC and FUBP1, respectively, 58% of which were predicted to result in truncations of the encoded proteins. These results suggest a critical role for these genes in the biology and pathology of oligodendrocytes.

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Mitochondrial DNA (mtDNA) alterations and their clinical and pathological implications have been analyzed in several human malignancies. A marked decrease in mtDNA copy number along with the increase in malignancy was observed in diffusely infiltrating astrocytomas (24 WHO grade II, 18 grade III, and 78 grade IV or GBM) compared to non-neoplastic brain tissues, being mostly depleted in GBM. Although high relative gene expression levels of mtDNA replication regulators (mitochondrial polymerase catalytic subunit (POLG), transcription factors A (TFAM), B1 (TFB1M) and B2 (TFB2M)) were detected, it cannot successfully revert the mtDNA depletion observed in our samples. On the other hand, a strong correlation among the expression levels of mitochondrial transcription factors corroborates with the TFAM role in the direct control of TFB1M and TFB2M during initiation of mtDNA replication. POLG expression was related to decreased mtDNA copy number, and its overexpression associated with TFAM expression levels also have an impact on long-term survival among GBM patients, interpreted as a potential predictive factor for better prognosis. (C) 2010 Elsevier B.V. and Mitochondria Research Society. All rights reserved.

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The ability of mesenchymal stem cells to generate functional neurons in culture is still a matter of controversy. In order to assess this issue, we performed a functional comparison between neuronal differentiation of human MSCs and fetal-derived neural stem cells (NSCs) based on morphological, immunocytochemical, and electrophysiological criteria. Furthermore, possible biochemical mechanisms involved in this process were presented. NF200 immunostaining was used to quantify the yield of differentiated cells after exposure to CAMP. The addition of a PKA inhibitor and Ca(2+) blockers to the differentiation medium significantly reduced the yield of differentiated cells. Activation of CREB was also observed on MSCs during maturation. Na(+)-, K(+)-, and Ca(2+)-voltage-dependent currents were recorded from MSCs-derived cells. In contrast, significantly larger Na(+) currents, firing activity, and spontaneous synaptic currents were recorded from NSCs. Our results indicate that the initial neuronal differentiation of MSCs is induced by CAMP and seems to be dependent upon Ca(2+) and the PKA pathway. However, compared to fetal neural stem cells, adult mesenchymal counterparts are limited in their neurogenic potential. Despite the similar yield of neuronal cells, NSCs achieved a more mature functional state. Description of the underlying mechanisms that govern MSCs` differentiation toward a stable neuronal phenotype and their limitations provides a unique opportunity to enhance our understanding of stem cell plasticity. (C) 2009 Elsevier Inc. All rights reserved.

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Cell surface proteins are excellent targets for diagnostic and therapeutic interventions. By using bioinformatics tools, we generated a catalog of 3,702 transmembrane proteins located at the surface of human cells (human cell surfaceome). We explored the genetic diversity of the human cell surfaceome at different levels, including the distribution of polymorphisms, conservation among eukaryotic species, and patterns of gene expression. By integrating expression information from a variety of sources, we were able to identify surfaceome genes with a restricted expression in normal tissues and/or differential expression in tumors, important characteristics for putative tumor targets. A high-throughput and efficient quantitative real-time PCR approach was used to validate 593 surfaceome genes selected on the basis of their expression pattern in normal and tumor samples. A number of candidates were identified as potential diagnostic and therapeutic targets for colorectal tumors and glioblastoma. Several candidate genes were also identified as coding for cell surface cancer/testis antigens. The human cell surfaceome will serve as a reference for further studies aimed at characterizing tumor targets at the surface of human cells.

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Glioblastoma multiforme ( GBM) is the most common and lethal type of brain cancer. To identify the genetic alterations in GBMs, we sequenced 20,661 protein coding genes, determined the presence of amplifications and deletions using high- density oligonucleotide arrays, and performed gene expression analyses using next- generation sequencing technologies in 22 human tumor samples. This comprehensive analysis led to the discovery of a variety of genes that were not known to be altered in GBMs. Most notably, we found recurrent mutations in the active site of isocitrate dehydrogenase 1 ( IDH1) in 12% of GBM patients. Mutations in IDH1 occurred in a large fraction of young patients and in most patients with secondary GBMs and were associated with an increase in overall survival. These studies demonstrate the value of unbiased genomic analyses in the characterization of human brain cancer and identify a potentially useful genetic alteration for the classification and targeted therapy of GBMs.

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Animal studies in mice, rats, rabbits, pigs and hens demonstrated that anterior keratocytes undergo programmed cell death or apoptosis after corneal epithelial injury. Many other wound healing changes subsequently follow the keratocyte apoptosis response. This study evaluated early keratocyte apoptosis after corneal epithelial scrape injury in human eyes scheduled for enucleation for malignancy. Two eyes had corneal epithelial scrape 1 h prior to the enucleation and another eye served as a control and had no corneal scrape prior to enucleation. One additional eye was enucleated, washed with balanced salt solution, and then had the corneal epithelium scraped 1 h prior to processing for analysis. Apoptosis was identified by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay and confirmed by transmission electron microscopy (TEM). Anterior keratocyte apoptosis was detected in the three corneas that had epithelial scrape injury, but not in the control unwounded cornea. This study confirmed that keratocyte apoptosis is also an early response to corneal epithelial injury in humans and showed that tears are not essential for keratocyte apoptosis to occur in response to epithelial injury. (C) 2009 Elsevier Ltd. All rights reserved.

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The human endometrium is a dynamic tissue that undergoes cycles of growth and regression with each menstrual cycle. Adult progenitor stem cells are likely responsible for this remarkable regenerative capacity; these same progenitor stem cells may also have an enhanced capacity to generate endometriosis if shed in a retrograde fashion. The progenitor stem cells reside in the uterus; however, less-committed mesenchymal stem cells may also travel from other tissues such as bone marrow to repopulate the progenitor population. Mesenchymal stem cells are also involved in the pathogenesis of endometriosis and may be the principle source of endometriosis outside of the peritoneal cavity when they differentiate into endometriosis in ectopic locations. Finally, besides progenitor stem cells, recent publications have identified multipotent stem cells in the endometrium. These multipotent stem cells are a readily available source of cells that are useful in tissue engineering and regenerative medicine. Endometrial stem cells have been used to generate chondrocytes, myocytes, neurons, and adiposites in vitro as well as to replace dopaminergic neurons in a murine model of Parkinson`s disease.

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Objective: To assess the association between the depth of trophoblastic penetration into the tubal wall with serum concentrations of vascular endothelial growth factor (VEGF) and beta-hCG and to assess its predictive value. Design: Prospective study. Setting: Tertiary care university hospital. Patient(s): Thirty patients with ampullary pregnancy undergoing salpingectomy were analyzed. Intervention(s): Trophoblastic invasion was histologically classified as stage I when limited to the tubal mucosa, stage II when extending to the muscle layer, and stage III in the case of complete tubal wall infiltration. Main Outcome Measure(s): The relation between depth of trophoblastic infiltration into the tubal wall with VEGF and beta-hCG serum concentrations on the day of surgery. Result(s): An association between the depth of trophoblastic invasion and maternal serum concentrations of VEGF and beta-hCG was observed. VEGF levels of 297.2 pg/mL showed 100.0% sensitivity and 90.0% specificity for stage I, and levels of 440.1 pg/mL showed 81.8% sensitivity and 88.8% specificity for stage III. Beta-hCG levels of 2590.0 mIU/mL showed 88.9% sensitivity and 80.0% specificity for stage I, and levels of 10,827.0 mUI/mL showed 72.7% sensitivity and 88.9% specificity for stage III. Conclusion(s): Maternal serum VEGF and beta-hCG concentrations are associated with depth of trophoblastic penetration into the tubal wall. (Fertil Steril (R) 2010;94:1595-600. (C) 2010 by American Society for Reproductive Medicine.)

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Introduction: Data on epidemiology of HPV infection are needed for the development of human papillomavirus (HPV) vaccine recommendations, especially in countries where HPV vaccination is not yet included in public vaccination programs. The aim of this study was to determine the prevalence of serum antibodies to HPV types 6, 11, 16, and 18 and associated factors among young women after birth of the first child. Methods: This cross-sectional study was carried out in a large public maternity hospital in Sao Paulo, Brazil. Three hundred one women aged 15 to 24 years who gave birth to their first child were recruited between 43 and 60 days after delivery. Seroprevalence was performed using a type-specific enzyme-linked immunosorbent assay based on HPV Late protein 1 viruslike particles. The association of seroreactivity with these 4 HPV types with selected demographic and behavioral factors was assessed by Generalized Linear Model analysis. Results: Fifty-eight (19.3%) women (95% confidence interval, 15.0%-24.2%) had antibodies to any of the 4 viruslike particles tested. The overall seroprevalence rates of the HPV types were: HPV16, 9.0%; HPV18, 7.0%; and HPV 6+11, 7.7%, which are targeted by the HPV prophylactic vaccines. In the multivariate analysis, only age (inversely, P = 0.044 for trend) and previous sexually transmitted disease (P = 0.008) were 2 factors independently associated with HPV seropositivity. Conclusions: These data offer additional information on the epidemiology of HPV in a group of young Brazilian women after first delivery and contribute to establish a baseline of HPV seroprevalence against which post-HPV vaccine era seroprevalence can be compared.

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Human biomonitoring (HBM) of environmental contaminants plays an important role in estimating exposure and evaluating risk, and thus it has been increasingly applied in the environmental field. The results of HBM must be compared with reference values ( RV). The term ""reference values"" has always been related to the interpretation of clinical laboratory tests. For physicians, RV indicate ""normal values"" or ""limits of normal""; in turn, toxicologists prefer the terms ""background values"" or ""baseline values"" to refer to the presence of contaminants in biological fluids. This discrepancy leads to the discussion concerning which should be the population selected to determine RV. Whereas clinical chemistry employs an altered health state as the main exclusion criterion to select a reference population ( that is, a ""healthy"" population would be selected), in environmental toxicology the exclusion criterion is the abnormal exposure to xenobiotics. Therefore, the choice of population to determine RV is based on the very purpose of the RV to be determined. The present paper discusses the concepts and methodology used to determine RV for biomarkers of chemical environmental contaminants.

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Background Recent studies support an important role for human papillomavirus (HPV) in a subgroup of head and neck squamous cell carcinomas (HNSCC). We have evaluated the HPV deoxyribonucleic acid (DNA) prevalence as well as the association between serological response to HPV infection and HNSCC in two distinct populations from Central Europe (CE) and Latin America (LA). Methods Cases (n = 2214) and controls (n = 3319) were recruited from 1998 to 2003, using a similar protocol including questionnaire and blood sample collection. Tumour DNA from 196 fresh tissue biopsies was analysed for multiple HPV types followed by an HPV type-specific polymerase chain reaction (PCR) protocol towards the E7 gene from HPV 16. Using multiplex serology, serum samples were analysed for antibodies to 17 HPV types. Statistical analysis included the estimation of adjusted odds ratios (ORs) and the respective 95% confidence intervals (CIs). Results HPV16 E7 DNA prevalence among cases was 3.1% (6/196), including 4.4% in the oropharynx (3/68), 3.8% in the hypopharynx/larynx (3/78) and 0% among 50 cases of oral cavity carcinomas. Positivity for both HPV16 E6 and E7 antibodies was associated with a very high risk of oropharyngeal cancer (OR = 179, 95% CI 35.8-899) and hypopharyngeal/laryngeal cancer (OR = 14.9, 95% CI 2.92-76.1). Conclusions A very low prevalence of HPV DNA and serum antibodies was observed among cases in both CE and LA. The proportion of head and neck cancer caused by HPV may vary substantially between different geographical regions and studies that are designed to evaluate the impact of HPV vaccination on HNSCC need to consider this heterogeneity.

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Background Infective dermatitis (ID) is a rare dermatologic condition of childhood that has been linked to human T-cell lymphotropic virus type 1 (HTLV-1). Objective To analyze the clinical and laboratory features associated with adult-onset ID linked to HTLV-1. Methods From December 1995 to December 2007, four patients with ID were followed in the dermatology outpatient clinic of the ""Hospital das Clinicas"" of the University of Sao Paulo Medical School, Sao Paulo, Brazil. Epidemiologic data were collected and dermatologic examination was performed. Patients were submitted to histopathologic, hematologic, virologic, and immunologic investigations. Results All patients had a diagnosis of ID according to previously established criteria, despite being adults. HTLV-1 infection was demonstrated by enzyme-linked immunosorbent assay, Western blotting assays, and polymerase chain reaction. The male to female ratio was 1 : 3 and the median age at diagnosis was 42 years. The cutaneous manifestations were erythematous, scaly, and crusted lesions in all patients, and ichthyosis in three of the four cases. Histopathologic study showed lymphocytic epidermotropism in two cases. The median proviral load was 281 copies/10,000 peripheral blood mononuclear cells. Immunodeficiency was not observed in any case. The therapies used were antimicrobials, corticosteroids, and phototherapy. Conclusions Although many authors have considered ID to be a form of childhood dermatitis, we have described four cases that fulfilled the major criteria for ID, except for onset in adulthood.

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This was a longitudinal study carried out during a period over 2 years with a cohort of 946 individuals of both sexes, aged 1 year and older, from an endemic area of American visceral leishmaniasis (AVL) in Para State, Brazil. The object was to analyze the transmission dynamics of human Leishmania (Leishmania) infantum chagasi infection based principally on the prevalence and incidence. For diagnosis of the infection, the indirect fluorescent antibody test (IFAT) and leishmanin skin test (LST) were performed with amastigote and promastigote antigens of the parasite, respectively. The prevalence by LST (11.2%) was higher (p < 0.0001) than that (3.4%) by IFAT, and the combined prevalence by both tests was 12.6%. The incidences by LST were also higher (p < 0.05) than those by IFAT at 6 (4.7% A- 0.6%), 12 (4.7% A- 2.7%), and 24 months (2.9% A- 0.3%). Moreover, there were no differences (p > 0.05) between the combined incidences by both tests on the same point surveys, 5.2%, 6.3%, and 3.6%. During the study, 12 infected persons showed high IFAT IgG titers with no LST reactions: five children and two adults developed AVL (2,560-10,120), and two children and three adults developed subclinical oligosymptomatic infection (1,280-2,560). The combined tests diagnosed a total of 231 cases of infection leading to an accumulated prevalence of 24.4%.

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Mast cells (MCs) are associated with chronic inflammatory diseases. However, there is no study evaluating the importance of MCs in the mucosal leishmaniasis (ML). The aim of this study was to quantify the most important cytokines associated with mucosal leishmaniasis, before and after disease treatment, correlating with the healing. A cohort of 12 patients with ML was evaluated, and biopsies were taken before and after the treatment. A quantitative estimation of MCs and some cytokines was analysed by density of the labelled cells through immunohistochemistry. The MCs count in the tissue from patients with ML before treatment showed a mean of 29.3 +/- 37.9 cells/mm(2). The MCs count in patients with ML after healing decreased to 14.8 +/- 23.9 cells/mm(2). There was an inverse relation of MCs with IFN-gamma and IL-4 expression (r(2) = 29.4 and r(2) = 22.3 with P < 0.05). The expression of IL-10 and TNF-alpha was not related with MCs count. MCs decrease after treatment associated with decrease of IL-4 and IFN-gamma. The explanations of cytokine correlation are discussed in the article.

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Human immunodeficiency virus type 1 (HIV-1) and human T-cell lymphotropic virus types 1 and 2 (HTLV-1 and -2) are retroviruses that share similar routes of transmission and some individuals may have a dual infection. These co-infected subjects may be at increased risk for tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM)-like. To study the prevalence of tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM) among coinfected HIV-1/HTLV-1 subjects. Since July 1997, our group has been following a cohort to study the interaction of HTLV with HIV and/or hepatitis C virus (HCV), as well as HTLV-1-only infected asymptomatic carriers or those already presenting with TSP/HAM. During these 9 years, 296 HTLV-1-infected individuals were identified from a total of 538 patients who were referred to our clinic at the Institute of Infectious Diseases ""Emilio Ribas,"" in Sao Paulo, Brazil. All subjects were evaluated by two neurologists, blinded to the HTLV status. TSP/HAM diagnosis was based on Kagoshima diagnostic criteria. Results: A total of 38 HIV-1/HTLV-1 co-infected subjects were identified in this cohort: Twenty-six had already been diagnosed with AIDS and 12 remained asymptomatic. Six of 38 co-infected subjects (18%) were diagnosed as having TSP/HAM and also AIDS, and for 5 of them TSP/HAM was their first illness. One additional incident case was diagnosed after 2 years of follow-up. No modifications on HIV-1 viral load was seen. In contrast, the co-infected with TSP/HAM-like group showed higher HTLV-1 proviral load (505 +/- 380 vs. 97 +/- 149 copies/10(4) PBMC, P= 0.012) than asymptomatic co-infected subjects, respectively. The incidence of myelopathy among HIV-1/HTLV-1 co-infected subjects is probably higher than among patients infected only with HTLV-1, and related to a higher HTLV-1 proviral load. Thus, HTLV-1/2 screening should be done for all HIV-1-infected patients in areas where HTLV-1 infection is endemic.