Development Of A Balb/c Mouse Model Of Helicobacter Pylori Infection With Fresh And Frozen Bacteria.

An experimental model for H. pylori infection was established by intragastrically challenging BALB/c mice with 1 ml (10(8) CFU/ml) of suspension for two consecutive days. Animals were divided into three groups. GA: mice inoculated with fresh bacteria; GB: mice inoculated with frozen bacteria, and GC: mice inoculated with brucella broth (control group). Animals were killed at 7, 14, 21, 28, 35 and 60 days pi and fragments of stomach and duodenum were collected, paraffin embedded and stained by hematoxylin-eosin and Giemsa. The results showed that challenged mice exhibited mild duodenitis and gastritis. In group GA, infiltration in the duodenum was lymphoplasmacytic until day 35; in group GB, it was lymphomonocytic for 60 days pi. In the stomach, H. pylori induced lymphomonocytic infiltration that was present from days 7 to 60 in group GA. In group GB, it was only present from days 14 to 35. In conclusion, our data suggested that freezing altered pathogenic properties of H. pylori and probably inhibited expression of bacterial antigens and consequently the establishment and maintenance of infection. Although the animals developed mild duodenitis and gastritis, the BALB/c mouse is not susceptible to developing peptic ulcers during H. pylori infection.38101-

Análise comparativa de mapas de eletroforese bidimensional (2-DE) de Helicobacter pylori de pacientes brasileiros com úlcera duodenal e gastrite crônica: relato preliminar

O Helicobacter pylori é uma bactéria reconhecida como a principal causa de úlcera péptica e gastrite crônica. Recentemente, o proteoma do H. pylori tem sido desenvolvido visando identificar fatores patogênicos relacionados ao microorganismo. Neste estudo preliminar, cepas de H. pylori foram isoladas de fragmento de mucosa gástrica de pacientes com úlcera duodenal e gastrite crônica. Posteriormente, realizou-se uma análise proteômica parcial dessas cepas, através da lise bacteriana e da separação de proteínas através da eletroforese de duas dimensões (2-DE). Por análise comparativa, foi possível verificar a expressão protéica diferencial entre os dois mapas 2-DE obtidos. Os dados poderão ser úteis para esclarecer a importância de diferentes proteínas relacionadas à patogênese da bactéria. Este estudo será complementado utilizando um maior número de amostras e a identificação protéica do H. pylori através da espectrometria de massa do tipo MALDI-TOF.Helicobacter pylori is a bacterium recognized as the major cause of peptic ulcer and chronic gastritis. Recently, a proteome-based approach was developed to investigate pathogenic factors related to H. pylori. In this preliminary study, H. pylori strains were isolated from gastric biopsies of patients with chronic gastritis and duodenal ulcers. A partial proteomic analysis of H. pylori strains was performed by bacterial lyses and proteins were separated by two-dimensional gel electrophoresis (2-DE). A comparative analysis was performed to verify a differential protein expression between these two 2-DE maps. These data should be useful to clarify the role of different proteins related to bacterial pathogenesis. This study will be completed using a larger number of samples and protein identification of H. pylori by MALDI-TOF mass spectrometry

Development of a BALB/c mouse model of Helicobacter pylori infection with fresh and frozen bacteria

An experimental model for H. pylori infection was established by intragastrically challenging BALB/c mice with 1 ml (10(8) CFU/ml) of suspension for two consecutive days. Animals were divided into three groups. GA: mice inoculated with fresh bacteria; GB: mice inoculated with frozen bacteria, and GC: mice inoculated with brucella broth (control group). Animals were killed at 7, 14, 21, 28, 35 and 60 days pi and fragments of stomach and duodenum were collected, paraffin embedded and stained by hematoxylin-eosin and Giemsa. The results showed that challenged mice exhibited mild duodenitis and gastritis. In group GA, infiltration in the duodenum was lymphoplasmacytic until day 35; in group GB, it was lymphomonocytic for 60 days pi. In the stomach, H. pylori induced lymphomonocytic infiltration that was present from days 7 to 60 in group GA. In group GB, it was only present from days 14 to 35. In conclusion, our data suggested that freezing altered pathogenic properties of H. pylori and probably inhibited expression of bacterial antigens and consequently the establishment and maintenance of infection. Although the animals developed mild duodenitis and gastritis, the BALB/c mouse is not susceptible to developing peptic ulcers during H. pylori infectio

Grading and staging chronic hepatitis C and its relation to genotypes and epidemiological factors in brazilian blood donors

Progression of chronic hepatitis C is known to be associated with some factors, but influence of HCV genotypes is still controversial. Association between HCV genotypes and other risk factors was examined to determine which factors are associated with progression of infection. One hundred consecutive anti-HCV positive volunteer blood donors were evaluated for several risk factors, examined for HCV genotypes, and submitted to hepatic biopsy and biochemical exams.HCV genotyping were carried out in 89 patients and hepatic biopsy in 78. Transmission routes were found to be illicit intravenous drug use (26%), Gluconergan® use in a non-safe manner (48%) and blood transfusion (15%). HCV genotype was 1 in 45%, 3 in 40%, and it was not associated with the stage of fibrosis or with inflammatory activity. There was no significant association of factors related to infection, chronic alcohol use, or duration of illness, with progression of the lesion. There was a significant association of aminotransferase levels and the fibrosis stage. Univariate analysis showed that the age at contamination, patient's age, GT-gamma, and aminotransferase levels over three times the upper normal limits, were associated with fibrosis stages 2 to 4. Multivariate analysis detected age (odds ratio=1.19), and GT-gamma (odds ratio=2.02) as independent factors

Progression of liver fibrosis in blood donors infected with hepatitis C virus

Background/Aims. Chronic hepatitis by HCV is progressive towards cirrhosis, with variable rate. We evaluated the rate of fibrosis progression (RFP), risk factors associated with advanced fibrosis (F3 and F4), and estimated the evolution time to cirrhosis. Methods. We transversely selected 142 blood donors infected only with HCV, with a known route of infection, submitted to liver biopsy at admission. RFP= ratio between stage of fibrosis (METAVIR)/estimated duration of infection in years. Non-parametric tests and logistic regression analysis, with significance level of 5% were used. Results. Median RFP was 0.086 U/year (0.05 - 0.142). Ten patients had F4 and 25 had F3. Median RFP values were significantly different (p=0.001) from one age group at contamination to the others and ALT and AST levels. There were no differences in the expected evolution to cirrhosis between intermediate fibrosers (F2) and the rapid fibrosers (F3 and F4). The independent variables associated with advanced fibrosis were ALT (OR 7.2) and GGT (OR 6.4) and age at inclusion (OR 1.12). Conclusion. This study suggests that RFP is extremely variable, it is exponential with age, and mainly influenced by host characteristics, especially age at contamination and possibly ethnical group. These asymptomatic patients had high percentage of fibrosis F2, F3 and F4