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Search Results: 1 - 10 of 16618 matches for " Silvia Helena Barem Rabenhosrt "
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Presence of the Genes cagA, cagE, virB11 and Allelic Variation of vacA of Helicobacter pylori Are Associated with the Activity of Gastritis  [PDF]
Pedro Pinheiro de Negreiros Bessa, Francivandi Coelho Barbosa, Ana Paula Santos do Carmo, Gildo Barreira Furtado, Fernanda Capelo Barroso, Silvia Helena Barem Rabenhosrt
Open Journal of Gastroenterology (OJGas) , 2014, DOI: 10.4236/ojgas.2014.411049
Abstract: Non-atrophic active chronic gastritis (ACG) is characterized by the presence of H. pylori in the gastric epithelium, known to be one of the first steps that precede progression to gastric adenocarcinoma. Inactive chronic gastritis (ICG) suggests that the patient has H. pylori gastritis, but this diagnosis is rarely made in routine histopathology. Clinical manifestations associated with H. pylori infection are potentially due to differences in virulence between strains; however, it is unclear if the progression of ACG to ICG depends on the H. pylori strain. The aim of this study was to compare the prevalence of the virulence factors of H. pylori found in patients with ACG and ICG, and its influence on the development of ICG. A significant association was observed between H. pylori detection by histological examination and the activity of gastritis (p < 0.01). Long-term use of proton pump inhibitors (PPI) (>1 year) was reported by 28.6% of the ACG group and 42.5% of the ICG, while no evidence of association between long-term use of PPI and decreased inflammation was found in the patients studied. The genes cagA, cagE and virB11 were statistically associated with ACG (p = 0.01, p < 0.001 and p = 0.002, respectively). In the vacAs1 allele groups, ACG was associated with the most virulent group (p = 0.0015), while ICG was associated with the less virulent group (p < 0.001). The rate of co-infection was significantly higher in ICG than in ACG cases (p = 0.02). In conclusion, this study points to the role of virulent strains of H. pylori in the non-resolution of gastritis.
Estratégias auxiliares para gradua??o dos tumores astrocíticos segundo os critérios histopatológicos estabelecidos pela OMS
Faria, Mário Henrique Gir?o;Patrocínio, Régia Maria do Socorro Vidal do;Rabenhorst, Silvia Helena Barem;
Jornal Brasileiro de Patologia e Medicina Laboratorial , 2006, DOI: 10.1590/S1676-24442006000500012
Abstract: background: despite recent discoveries concerning molecular alterations involved in astrocytoma tumorigenesis, the conventional histological analysis remains the best diagnostic method and a reasonable prognostic indicator for astrocytic tumors. however, the histopathological routine recommended by the world health organization (who) is laborious and marked by low reproducibility. objective: the present study aimed to develop auxiliary strategies for astrocytic tumor graduation according to histological criteria established by who. material and method: a clinical and epidemiological analysis and a histopathological evaluation were performed in 55 astrocytomas of different graduations (13 grade i, 14 grade ii, seven grade iii, 21 grade iv) and five samples of non-tumor tissue (control group). results: the distribution by age, sex, and tumor localization of astrocytomas in patients reproduced, in a general way, worldwide trends. the presence of multinucleated cells and gemistocytes was associated with tumoral malignancy. the histopathological findings evaluated through semi-quantitative criteria and cart modeling confirmed the primary classification, reaffirming their applicability and reproducibility. conclusion: these results indicate the cart decision tree and the totality of semi-quantitative scores as practical and auxiliary strategies for astrocytoma graduation as stated by who criteria.
Express?o das proteínas BCL-2 e BAX em tumores astrocíticos humanos
Faria, Mário Henrique Gir?o;Patrocínio, Régia Maria do Socorro Vidal do;Moraes Filho, Manoel Odorico de;Rabenhorst, Silvia Helena Barem;
Jornal Brasileiro de Patologia e Medicina Laboratorial , 2006, DOI: 10.1590/S1676-24442006000400008
Abstract: background: astrocytomas represent the most frequent primary tumors of the central nervous system. admittedly, part of tumor growth is due to inhibition of programmed cell death: the apoptosis. this phenomenon is basically regulated by the balance between anti-apoptotic (e.g.: b-cell lymphoma protein 2 [bcl-2]) and pro-apoptotic (e.g.: bcl-2 associated protein x [bax]) molecules. objective: the present study aimed to evaluate the expression of bcl-2 and bax in human astrocytic tumors of different histopathological grades. material and method: an immunohistochemical study of those proteins using the avidin-biotin-peroxidase method was performed in 55 astrocytomas (13 grade i, 14 grade ii, seven grade iii and 21 grade iv) and five samples of non-tumor brain tissue (control group). results: the bcl-2 and bax positive indices tended to increase according to astrocytomas graduation, with general positivity of 43.26% and 24.67%, respectively. these proteins were not detected among non-tumor specimens. bcl-2 labeling scores demonstrated a tendency to increase in accordance with histopathological advancing, while bax values were similar in all graduations. the combined analyses of these proteins expression presents a significant correlation with tumor grade (p < 0.05; h test), witch is more evident among glioblastomas (grade iv) in comparison with low-grade astrocytomas (i and ii) (p < 0.05; u test). bcl-2/bax ratio denoted increasing of cellular survival orientation of the astrocytic tumors according to malignant progression. conclusions: the results indicate alterations in bcl-2 and bax proteins expression as resultant of the tumorigenic process in astrocytomas, with increasing predominance of the anti-apoptotic profile in consonance of malignant transformation. in this way, we propose that bcl-2 overexpression in astrocytic tumors may be indicative of more aggressive phenotypes, furthermore configuring a potential therapeutic target.
Immunoexpression of tumor suppressor genes p53, p21WAF1/CIP1 and p27KIP1 in humam astrocystic tumors
Faria, Mário Henrique Gir?o;Patrocínio, Régia Maria do Socorro Vidal do;Moraes Filho, Manoel Odorico de;Rabenhorst, Silvia Helena Barem;
Arquivos de Neuro-Psiquiatria , 2007, DOI: 10.1590/S0004-282X2007000700004
Abstract: the aim of the present study was to evaluate the tumor suppressor genes p53, p21waf1/cip1 and p27kip1 expression in astrocytic tumors, correlating the findings with the histopathological grade (who). an immunohistochemical study of the p53, p21 and p27 proteins using the streptavidin-biotin-peroxidase method was performed in fifty-five astrocytomas (13 grade i, 14 grade ii, 7 grade iii and 21 grade iv) and five samples of non-tumor brain tissue (negative control). p53 positive indices (pi) and labeling indices (li) showed tendency to increase according to malignant progression. the nuclear expression of p27 presented similar inclination, except for the pi reduction verified in grade iv tumors. otherwise, the cytoplasmic p27 staining was more evident between high-grade tumors (iii and iv). p53 and nuclear p27 expression was correlated with the histological classification (p<0.01; test h). on the other hand, p21 indices revealed a propensity to reduction in agreement with malignant evolution of the astrocytic tumors, except for high scores observed in grade iv tumors. the non-tumor samples did not show any expression of these proteins. these results indicated the p53 mutation as an initial, relevant and potentially predictor of tumor progression event in astrocytomas, with the detection of p21 protein as an important resource for the deduction of functional situation of this gene. moreover, the activation of p27kip1 was preserved in the astrocytic tumors and its cytoplasmic manifestation seems to be resultant of its nuclear expression, not demonstrating a direct impact in astrocytomas tumorigenesis.
Candidemia in a Brazilian hospital: the importance of Candida parapsilosis
Medrano, Delia Jessica Astete;Brilhante, Raimunda Samia Nogueira;Cordeiro, Rossana de Aguiar;Rocha, Marcos Fábio Gadelha;Rabenhorst, Silvia Helena Barem;Sidrim, José Júlio Costa;
Revista do Instituto de Medicina Tropical de S?o Paulo , 2006, DOI: 10.1590/S0036-46652006000100004
Abstract: the aim of this study was to perform a retrospective analysis of cases of candidemia in a brazilian hospital in the city of fortaleza, ceará. a total of 50 blood cultures were analyzed from 40 candidemic patients. the mycological diagnosis was based on the phenotypical analysis and the patients' data were recorded in appropriate files. the most frequent species were candida parapsilosis (n = 18), followed by c. albicans (n = 14), c. tropicalis (n = 8), c. guillermondii (n = 6), c. glabrata (n = 2), and candida spp. (n = 2). a detailed descriptive study was undertaken with 21 patients whose medical records were complete. the candidemia episodes occurred in eight male patients and 13 female patients. the most representative risk factors implicated in candidemia were prior antibiotic therapy, central venous catheters, parenteral nutrition, gastric probes and mechanical ventilation. death occurred in 13 of the 21-candidemic patients. this study demonstrated the emergence of candidemia caused by c. parapsilosis in a brazilian hospital in the city of fortaleza, ceará.
Detec??o do vírus Epstein-Barr (EBV) em adenocarcinomas gástricos procedentes dos estados do Ceará e de S?o Paulo
Lima, Marcos Antonio Pereira de;Ferreira, Márcia Valéria Pitombeira;Barros, Marcos Aurélio Pessoa;Pardini, Maria Inês de Moura Campos;Ferrasi, Adriana Camargo;Rabenhorst, Silvia Helena Barem;
Jornal Brasileiro de Patologia e Medicina Laboratorial , 2011, DOI: 10.1590/S1676-24442011000200013
Abstract: introduction: the epstein-barr virus (ebv) has been associated with approximately 10% of gastric adenocarcinomas, which represents more than 50,000 cases/year worldwide. despite the studies undertaken in several countries, some clinical-pathological aspects remain contentious. objective: the objective of this study was to analyze clinical-pathological features of gastric adenocarcinomas from two brazilian states, s?o paulo and ceará, by correlating them with ebv detection. materials and methods: one hundred ninety-two gastric adenocarcinoma cases were selected from hospitals in s?o paulo and ceará, of which 160 were submitted to rna in situ hybridization for ebv detection. results: eleven (6.9%) out of 160 cases were ebv-positive with intense nuclear staining in tumor cells. among these, two cases also showed stained infiltrating lymphocytes. there was no staining in normal or preneoplastic tissue. s?o paulo and ceará yielded the respective results: 3/60 (5%) and 8/100 (8%). in both states, ebv was more prevalent among elder male patients with little to moderately differentiated intestinal tumors in advanced stage. ceará cases substantiated a relative increase in ebv(+) tumors located in the cardia, whereas s?o paulo cases presented an increase in the gastric corpus. conclusion: the frequency of ebv(+) tumors is similarly described in the literature. among our findings, the elevated percentage of ebv(+) tumors in the gastric corpus, which was observed in s?o paulo cases, is unprecedented in the literature.
Epstein-Barr virus-associated gastric carcinoma in Brazil: comparison between in situ hybridization and polymerase chain reaction detection
Lima, Marcos Antonio Pereira de;Ferreira, Márcia Valéria Pitombeira;Barros, Marcos Aurélio Pessoa;Pardini, Maria Inês de Moura Campos;Ferrasi, Adriana Camargo;Rabenhorst, Silvia Helena Barem;
Brazilian Journal of Microbiology , 2012, DOI: 10.1590/S1517-83822012000100048
Abstract: epstein-barr virus (ebv) has been associated with 10% of gastric carcinomas. the aim of this study was to determine the frequency of ebv in gastric carcinomas in brazil assessed by in situ hybridization (ish) and pcr, which would contribute to the characterization of the clinical and pathological aspects of ebv-associated gastric carcinomas. one hundred and ninety-two gastric carcinoma cases were collected at hospitals in two brazilian states. seventy-three out of 151 cases were pcr(+), while 11/160 cases were ish(+). nine out of eleven ish(+) cases displayed a diffuse staining pattern and 2 out of 11 a focal pattern. both techniques showed that the ebv(+) cases were characterized by their association with males, older patients, lower gastric region, intestinal type, advanced stage and poorly to moderately differentiated tumors. the concordance between the two techniques was 55.8% (cohen's kappa index = 0.034). four cases were ish(+)/pcr(-), while 49 cases were pcr(+)/ish(-). only two cases showed stained lymphocytes by ish and one of them was pcr(-). the observed discrepancy between the two techniques could not be explained just by the elevated accuracy of pcr. ish(+)/pcr(-) carcinomas may be encountered if ebv is not present in the whole tumor tissue or if there are polymorphisms in the sequences of the viral genome amplified. on the other hand, the high frequency of pcr(+) results associated with the absence of ish staining in lymphocytes and/or tumors cells suggests that the virus may be present in tumor cells or other cell types without expressing eber1, the target of the ish technique.
Helicobacter pylori and EBV in gastric carcinomas: Methylation status and microsatellite instability
Adriana Camargo Ferrasi, Nídia Alice Pinheiro, Silvia Helena Barem Rabenhorst, Otávia Luisa Caballero, Maria Aparecida Marchesan Rodrigues, Fabrício Carvalho, Celso Vieira Souza Leite, Marcia Valéria Pitombeira Ferreira, Marcos Aurélio Pessoa Barros, Mar
World Journal of Gastroenterology , 2010,
Abstract: AIM: To verify the methylation status of CDH1, DAPK, COX2, hMLH1 and CDKN2A genes and to evaluate their association with Helicobacter pylori (H. pylori)-cagA+ and Epstein Barr virus (EBV) infections in gastric adenocarcinomas.METHODS: Methylation-specific PCR (MSP) assay was performed in 89 primary gastric carcinomas (intestinal and diffuse types). Microsatellite instability (MSI) analysis was performed using the BAT26 primer set and PCR products were analyzed with the ABI PRISM 3100 Genetic Analyzer using Genescan 3.7 software (Applied Biosystems). Detection of H. pylori and genotyping were performed by PCR, using specific primers for ureaseC and cagA genes. The presence of EBV was assessed by in situ hybridization. Statistical analyses were performed using the χ2 or Fisher’s exact test.RESULTS: The most frequent hypermethylated gene was COX-2 (63.5%) followed by DAPK (55.7%), CDH1 (51%), CDKN2A (36%) and hMLH1 (30.3%). Intestinal and diffuse adenocarcinomas showed different methylation profiles and there was an association between methylation of E-CDH1 and H. pylori-cagA+ in the intestinal adenocarcinoma type. MSI was correlated with hMLH1 methylation. There was an inverse correlation between DAPK hypermethylation and MSI.CONCLUSION: We found a strong association between CDH1 methylation and H. pylori-cagA+ in intestinal-type gastric cancer, association of MSI and better prognosis and an heterogeneous COX-2 overexpression.
Experimental Gastric Carcinogenesis in Cebus apella Nonhuman Primates
Joana de Fátima Ferreira Borges da Costa,Mariana Ferreira Leal,Tanielly Cristina Raiol Silva,Edilson Ferreira Andrade Junior,Alexandre Pingarilho Rezende,José Augusto Pereira Carneiro Muniz,Antonio Carlos Cunha Lacreta Junior,Paulo Pimentel Assump??o,Danielle Queiroz Calcagno,Samia Demachki,Silvia Helena Barem Rabenhorst,Marília de Arruda Cardoso Smith,Rommel Rodriguez Burbano
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0021988
Abstract: The evolution of gastric carcinogenesis remains largely unknown. We established two gastric carcinogenesis models in New-World nonhuman primates. In the first model, ACP03 gastric cancer cell line was inoculated in 18 animals. In the second model, we treated 6 animals with N-methyl-nitrosourea (MNU). Animals with gastric cancer were also treated with Canova immunomodulator. Clinical, hematologic, and biochemical, including C-reactive protein, folic acid, and homocysteine, analyses were performed in this study. MYC expression and copy number was also evaluated. We observed that all animals inoculated with ACP03 developed gastric cancer on the 9th day though on the 14th day presented total tumor remission. In the second model, all animals developed pre-neoplastic lesions and five died of drug intoxication before the development of cancer. The last surviving MNU-treated animal developed intestinal-type gastric adenocarcinoma observed by endoscopy on the 940th day. The level of C-reactive protein level and homocysteine concentration increased while the level of folic acid decreased with the presence of tumors in ACP03-inoculated animals and MNU treatment. ACP03 inoculation also led to anemia and leukocytosis. The hematologic and biochemical results corroborate those observed in patients with gastric cancer, supporting that our in vivo models are potentially useful to study this neoplasia. In cell line inoculated animals, we detected MYC immunoreactivity, mRNA overexpression, and amplification, as previously observed in vitro. In MNU-treated animals, mRNA expression and MYC copy number increased during the sequential steps of intestinal-type gastric carcinogenesis and immunoreactivity was only observed in intestinal metaplasia and gastric cancer. Thus, MYC deregulation supports the gastric carcinogenesis process. Canova immunomodulator restored several hematologic measurements and therefore, can be applied during/after chemotherapy to increase the tolerability and duration of anticancer treatments.
hTERT, MYC and TP53 deregulation in gastric preneoplastic lesions
Tanielly Cristina Raiol Silva, Mariana Ferreira Leal, Danielle Queiroz Calcagno, Carolo Rosal Teixeira de Souza, André Salim Khayat, Ney Pereira Carneiro dos Santos, Raquel Carvalho Montenegro, Silvia Helena Barem Rabenhorst, Mayara Quaresma Nascimento, Paulo Pimentel Assump??o, Marília de Arruda Cardoso Smith, Rommel Rodríguez Burbano
BMC Gastroenterology , 2012, DOI: 10.1186/1471-230x-12-85
Abstract: We evaluated 19 superficial gastritis, 18 atrophic gastritis, and 18 intestinal metaplasia from cancer-free individuals of Northern Brazil. Quantitative reverse transcription PCR was used to analyze the mRNA expression and immunohistochemical methods were used to assess protein immunoreactivity in tissue samples. The number of TP53 gene copies was investigated in gastric diseases by quantitative PCR.We observed hTERT, MYC, and p53 immunoreactivity only in intestinal metaplasia samples. The immunoreactivity of these proteins was strongly associated with each other. A significantly higher MYC mRNA expression was observed in intestinal metaplasia compared to gastritis samples. Loss of TP53 was also only detected in intestinal metaplasia specimens.We demonstrated that hTERT, MYC, and TP53 are deregulated in intestinal metaplasia of individuals from Northern Brazil and these alterations may facilitate tumor initiation.
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