RESUMO
Diseases resulting from Helicobacter pylori infection appear to be dependent on a host of genetic traits and virulence factors possessed by this microorganism. This paper aimed to investigate the association between the ABO histo-blood groups and H. pylori cagA infections. Genomic DNA samples (n = 110) of gastric biopsies obtained from patients with endoscopic diagnosis of peptic ulcers (n = 25) and chronic active gastritis (n = 85) were analyzed by PCR using specific primers for the cagA gene. Of the samples, 66.4 percent (n = 73) tested positive and 33.6 percent (n = 37) negative for the gene. The cagA strain was predominant in peptic ulcers (n = 21; 84.0 percent) compared with chronic active gastritis (n = 52; 61.2 percent) (p = 0.05; OR 3.332; 95 percent CI: 1.050-10.576). Additionally, the cagA strain was prevalent in the type O blood (48/63; 76.2 percent) compared with other ABO phenotypes (25/47; 53.2 percent) (p = 0.01; OR 2.816; 95 percent CI: 1.246-6.364). These results suggest that H. pylori cagA infection is associated with the O blood group in Brazilian patients suffering from chronic active gastritis and peptic ulcers.
Assuntos
Humanos , Masculino , Feminino , Sistema ABO de Grupos Sanguíneos , Gastrite/sangue , Helicobacter pylori , Infecções por Helicobacter/genética , Úlcera Péptica/sangueRESUMO
Diseases resulting from Helicobacter pylori infection appear to be dependent on a host of genetic traits and virulence factors possessed by this microorganism. This paper aimed to investigate the association between the ABO histo-blood groups and H. pylori cagA infections. Genomic DNA samples (n = 110) of gastric biopsies obtained from patients with endoscopic diagnosis of peptic ulcers (n = 25) and chronic active gastritis (n = 85) were analyzed by PCR using specific primers for the cagA gene. Of the samples, 66.4 percent (n = 73) tested positive and 33.6 percent (n = 37) negative for the gene. The cagA strain was predominant in peptic ulcers (n = 21; 84.0 percent) compared with chronic active gastritis (n = 52; 61.2 percent) (p = 0.05; OR 3.332; 95 percent CI: 1.050-10.576). Additionally, the cagA strain was prevalent in the type O blood (48/63; 76.2 percent) compared with other ABO phenotypes (25/47; 53.2 percent) (p = 0.01; OR 2.816; 95 percent CI: 1.246-6.364). These results suggest that H. pylori cagA infection is associated with the O blood group in Brazilian patients suffering from chronic active gastritis and peptic ulcers.(AU)
Assuntos
Humanos , Masculino , Feminino , Helicobacter pylori , Infecções por Helicobacter/genética , Gastrite/sangue , Úlcera Péptica/sangue , Sistema ABO de Grupos SanguíneosRESUMO
PURPOSE: Considering the importance of type beta thalassaemias as hereditary syndromes of high significance in different populations of Mediterranean origin and, by extension, in the Brazilian population, the objective of the present study was to determine by PCR/DGGE the gene structures responsible for neutral polymorphisms (frameworks) observed in the human beta globin gene associated with the mutations responsible for type beta thalassaemias in a sample of the Brazilian population and, more specifically, of the population of the State of São Paulo. PATIENTS AND METHODS: Thirty individuals with beta thalassaemic mutations were analyzed: 22 mutations were in codon 39 (C-->T), 5 in IVS1-110 (G-->A), 2 in IVS1-6 (T-->C) and 1 in IVS1-1 (G-->A). DNA was extracted and selective amplification was performed by PCR extending from position IVS1 nt 46 to IVS2 nt 126 (474 pb). The product was then analyzed by polyacrylamide gel electrophoresis on a denaturing 10-60% urea/formamide gradient. RESULTS: The results demonstrated that, as expected, the mutations responsible for type beta thalassaemia observed in this population are of Mediterranean origin, with 73% distribution represented by codon 39, 17% by IVS1-110, 7% by IVS1-6 and 3% by IVS1-1. In turn, framework distribution seems to indicate a higher frequency of Fr 1-1 in codon 39 and IVS1-110, of Fr 1-3 in IVS1-6 and of Fr 1-2 in IVS1-1. CONCLUSIONS: These results permit us to conclude that gene amplification by PCR followed by DGGE is an appropriate method for the separation of DNA molecules that differ even by a single base change and therefore can be utilized to detect the alterations observed in the human beta globin gene. This methodology shows that, using only a pair of primers, it is possible to define the frameworks that are observed in the beta globin gene.
Assuntos
Ditiotreitol/farmacologia , Globinas/genética , Papaína/farmacologia , Reação em Cadeia da Polimerase , Polimorfismo Genético , Talassemia beta/genética , Adolescente , Adulto , Brasil/epidemiologia , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Itália/etnologia , Masculino , Pessoa de Meia-Idade , Desnaturação de Ácido Nucleico , Portugal/etnologia , Espanha/etnologia , Talassemia beta/etnologiaRESUMO
OBJECTIVES: This paper was meant to analyse distribution of HbS carriers in Brazil, comprising its regional prevalence and the relationship with racial settlement and age groups. MATERIAL AND METHODS: 67,667 blood samples from 48 Brazilian towns were analysed from 1976 to 1988. Such samples were classified as Caucasoid and Negroid. The diagnosis was defined by means of qualitative electrophoresis in alkaline and acid pH, quantification of haemoglobin fractions, cytological studies and some cases were confirmed after examination of the parents. RESULTS: The study of those 67,667 samples allowed us to detect 1,492 HbS carriers (2.2%). That frequency is higher among Negroids (5.16%) than among Caucasoids (1.22%): Z = 22.1397 (Zcritical; 0.05 = 1.9600). Taking the HbS carrier distribution into consideration, we noticed that it is relatively homogeneous among Negroids and higher than 5% in 9 out of the 16 areas involved in the study. By classifying the age group of the areas in the general sample and by comparing the proportions, we found out that there are significant differences (chi 2 = 50.88; chi 2 critical; 0.05; 5 gl = 11.070). CONCLUSIONS: Sickle-cell anaemia diseases play an important role among the pathologies found in several countries, including Brazil. This paper shows that the carriers prevalence varies in the several areas under study and is higher among Negroids in almost all of them. The decreasing frequency occurring from North to South in the general samples and among Caucasoids may be assigned to the contribution of the Negroes in the interracial crossing, particularly in the Northeast.
Assuntos
População Negra , Hemoglobina Falciforme , População Branca , Distribuição por Idade , Brasil/epidemiologia , Humanos , PrevalênciaRESUMO
Haptoglobin types were determined in 626 individuals living in the State of São Paulo (Brazil). Of these, 484 had Hb AA, 31 major beta thalassemia, 43 minor beta thalassemia, 14 Hb SS, and 54 Hb AS. Frequency distribution of the three most common types observed among patients with type beta thalassemia differed significantly from that observed in the Caucasian group with Hb AA. There was a significant increase in Hp 1-1, which led us to assume that these disorders participate in a selective process acting on haptoglobins and altering the equilibrium of their frequencies. This relationship was not observed when we compared patients with Hb SS and Hb AS with Black patients with Hb AA, although the type most often observed among patients with Hb SS was Hp 1-1. The distributions of Hp groups observed among Caucasian and Black patients with Hb AA were similar to those obtained by other investigators for the South and Southeast regions of Brazil, with the exception of Rio de Janeiro.