18 research outputs found

    H. pylori-infection and antibody immune response in a rural Tanzanian population

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    BACKGROUND: Helicobacter pylori (H. pylori) infection is ubiquitous in sub-Saharan Africa, but paradoxically gastric cancer is rare. METHODS: Sera collected during a household-based survey in rural Tanzania in 1985 were tested for anti-H. pylori IgG and IgG subclass antibodies by enzyme immunoassay. Odds ratios (OR) and confidence intervals (CI) of association of seropositivity with demographic variables were computed by logistic regression models. RESULTS: Of 788 participants, 513 were aged ≤17 years. H. pylori seropositivity increased from 76% at 0–4 years to 99% by ≥18 years of age. Seropositivity was associated with age (OR 11.5, 95% CI 4.2–31.4 for 10–17 vs. 0–4 years), higher birth-order (11.1; 3.6–34.1 for ≥3(rd )vs. 1(st )born), and having a seropositive next-older sibling (2.7; 0.9–8.3). Median values of IgG subclass were 7.2 for IgG1 and 2.0 for IgG2. The median IgG1/IgG2 ratio was 3.1 (IQR: 1.7–5.6), consistent with a Th2-dominant immune profile. Th2-dominant response was more frequent in children than adults (OR 2.4, 95% CI 1.3–4.4). CONCLUSION: H. pylori seropositivity was highly prevalent in Tanzania and the immunological response was Th2-dominant. Th2-dominant immune response, possibly caused by concurrent bacterial or parasitic infections, could explain, in part, the lower risk of H. pylori-associated gastric cancer in Africa

    A Polymorphism in the Human UGRP1 Gene Promoter That Regulates Transcription Is Associated with an Increased Risk of Asthma

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    Several traits associated with asthma phenotypes, such as high total serum immunoglobulin E and bronchial hyperresponsiveness, have been linked by numerous genome-screen studies and linkage analyses to markers on human chromosome 5q31-q34. In the present article, we describe UGRP1 (encoding uteroglobin-related protein 1) as one of asthma-susceptibility genes that is located on chromosome 5q31-q32. UGRP1 is a homodimeric secretory protein of 17 kDa and is expressed only in lung and trachea. The G→A polymorphism was identified at −112 bp in the human UGRP1 gene promoter. The −112A allele is responsible for a 24% reduction in the promoter activity in relation to the −112G allele, as examined by transfection analysis. Electrophoretic mobility-shift analysis revealed that an unknown nuclear factor binds to the region around −112 bp. The binding affinity with the −112A oligonucleotide was reduced by approximately one half, as compared with the −112G oligonucleotide. In a case-control study using 169 Japanese individuals (84 patients with asthma and 85 healthy control individuals), those with a −112A allele (G/A or A/A) were 4.1 times more likely to have asthma than were those with the wild-type allele (G/G)
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