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Biomedical subjects

J Fierro

Publications and source records attributed to J Fierro.

7 recordsLinked to original sources
PubMed2005

Helicobacter pylori vacA s1a and s1b alleles from clinical isolates from different regions of Chile show a distinct geographic distribution.

AIM: To establish the most common vacA alleles in Helicobacter pylori (H pylori) strains isolated from Chilean patients and its relationship with gastritis and gastroduodenal ulcers. METHODS: Two hundred and forty five H pylori clinical isolates were obtained from 79 biopsies from Chilean infected patients suffering from gastrointestinal diseases. An average of 2-3 strains per patient was isolated and the vacA genotype was analyzed by PCR and 3% agarose electrophoresis. Some genotypes were checked by DNA sequencing. RESULTS: The most prevalent vacA genotype in Chilean patients was s1b m1 (76%), followed by s1a m1 (21%). In contrast, the s2 m2 genotype was scarcely represented (3%). The s1b m1 genotype was found most frequently linked to gastropathies (P<0.05) rather than ulcers. Ulcers were found more commonly in male and older patients. Curiously, patients living in cities located North and far South of Santiago, the capital and largest Chilean city, carried almost exclusively strains with the s1b m1 genotype. In contrast, patients from Santiago and cities located South of Santiago carried strains with either one or both s1a m1 and s1b m1 genotypes. Regarding the s2 m2 genotype, comparison with GenBank sequences revealed that Chilean s2 sequence was identical to those of Australian, American, and Colombian strains but quite different from those of Alaska and India. CONCLUSION: Differences in geographic distribution of the s and m vacA alleles in Chile and a relationship of s1b m1 genotype with gastritis were found. Sequence data in part support a hispanic origin for the vacA genotype. Asymmetric distribution of genotypes s1b m1 and s2 m2 recedes H Pylori strain distribution in Spain and Portugal.

Adolescent↗
PubMed2001

Computational method to assign microbial genes to pathways.

We present techniques that mine fully sequenced microbial genomes for functional relationships between genes. We show that genes related by one of four techniques are more likely to belong to the same cellular pathways. Furthermore, we demonstrate that the pathway of an uncharacterized gene may be inferred from those of its functionally related partners. Therefore, we are now able to assign most of the genes within bacteria to cellular pathways.

Computational Biology↗
PubMed1997

The natural history of Apis-specific IgG and IgG4 in beekeepers.

BACKGROUND: Most published studies on changes of specific IgG or its subclasses as a response to stimuli by allergens have been performed on patients under immunotherapy. There are few reports analysing the response to immunoglobulins in patients exposed to allergens in their natural habitats. OBJECTIVE: The aim of this work was to discover the natural history of Apis specific IgG (IgG-ap) and IgG4 (IgG4-ap) levels in beekeepers from the Canary Islands. METHODS: We studied 242 beekeepers (Bks). We used a questionnaire and measured total IgE and seric Apis specific IgE (IgE-ap), IgG-ap and IgG4-ap against Apis mellifera venom. RESULTS: All Bks had IgG-ap and IgG4-ap. IgE-ap was positive in 160 Bks (65.6%), but only 92 (37.6%) Bks were considered sensitized. IgG-ap and IgG4-ap showed significant correlation (r = 0.84); IgE did not correlate with IgG-ap or IgG4-ap. There was no seasonal variation in IgG-ap or IgG4-ap. The group of sensitized Bks had significantly lower IgG-ap and IgG4-ap levels (P < 0.05). The groups with longer beekeeping activity showed significantly higher levels of IgG-ap and IgG4-ap (P < 0.001). Bks with locals reactions had significantly higher IgG-ap and IgG4-ap than Bks who reported systemic reactions (P < 0.05). CONCLUSION: Our study showed that IgG-ap and IgG4-ap appear to increase in Bks, either according to their beekeeping experience or in subjects with local reactions after bee stings.

Adult↗
PubMed1992

[Hydatidosis in the IXth Region of Chile. A regional problem and challenge].

Infection by Echinococcus granulosus is the main zoonosis affecting the human population of the IXth Region in southern Chile. Prevalence rates vary from 18.2 to 48 per 100,000. Animals are affected with prevalence rates of 40% for bovines, 39.5% for sheep and 14.8% for pork as estimated at the central meat processing plant in the city of Temuco. A cost of approximately $300,000 is estimated to treat affected individuals. Much greater losses may be estimated from unnotified meat processing in rural areas and from reduced yield of animal products such as wool an milk. Accordingly, a regional program for control of this zoonosis is urgently required.

Animals↗
PubMedDate not supplied

Epidemiology of allergic reactions in beekeepers: a lower prevalence in subjects with more than 5 years exposure.

Beekeepers (Bks) represent a high allergic risk population against Hymenoptera because of their frequent exposure to bee stings. Most published studies show different percentage of sensitization and systemic reactions with to another groups of population. With the aim to know the prevalence and type of allergic reaction in Bks from the Canary Islands, 246 subjects were studied prospectively. A questionnaire was developed and skin test and specific IgE determination against Apis mellifera, Vespula and Polistes venom were performed. One hundred and twenty eight subjects had presented at least one reaction greater than merely local. In 83.5% of these subjects subsequent stings caused reactions of lesser intensity. Specific IgE in serum for Apis mellifera was positive in 126 BKs, for Vespula in 27 and for Polistes in 9. We found that the group of BKs sensitized to Apis was significantly higher among atopics BKs (p < 0.001) and with fewest years of working experience in beekeeping (p = 0.0134). This study showed that sensitization to Hymenoptera is higher in beekeepers with less than 5 years working experience and who are sensitized to another allergens.

Adult↗