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Biomedical subjects

Michele Boniotto

Publications and source records attributed to Michele Boniotto.

25 records · Page 2Linked to original sources
PubMed2002

Variant mannose-binding lectin alleles are associated with celiac disease.

In this study, we investigated the role of mannose-binding lectin (MBL) in celiac disease, by performing genotype analysis for the three point mutations in the first exon of the gene in 117 Italian celiac patients (characterized by flat biopsy and positive for anti-endomysium antibody and human transglutaminase antibodies) and 130 pan-ethnic healthy controls. The frequency of homozygous mutant 0/ 0 was significantly higher in the 117 Italian celiac patients (0.13) than in the 130 pan-ethnic healthy controls (0.05; P=0.0405). An increased frequency of homozygous 0/0 allele was found among patients with celiac disease compared with controls. These results suggest an involvement of MBL in the pathophysiology of celiac disease.

Alleles↗
PubMed2002

Prognostic value of the stromal cell-derived factor 1 3'A mutation in pediatric human immunodeficiency virus type 1 infection.

A mutation of the stromal cell-derived factor 1 gene (SDF-1 3'A) was shown to protect adults exposed to human immunodeficiency virus type 1 (HIV-1) from infection and to affect HIV disease progression in adults. The presence of this mutation in HIV-1-infected Kenyan children did not predict mother-to-child virus transmission. The SDF-1 3'A polymorphism was studied in 256 HIV-1-infected, 118 HIV-1-exposed but uninfected, and 170 unexposed and uninfected children of Italian origin, and the frequency of SDF-1 3'A heterozygosity and homozygosity in each of the 3 groups was similar. Of the 256 HIV-1-infected children, 194 were regularly followed up and were assigned to groups according to disease progression. The frequency of the SDF-1 3'A allele was substantially lower among children with long-term nonprogression than among children with rapid (P =.0329) or delayed (P =.0375) progression. We show that the presence of the SDF-1 3'A gene correlates with accelerated disease progression in HIV-1-infected children born to seropositive mothers but does not protect against mother-to-child HIV-1 transmission.

Adolescent↗
PubMed2002

Beta-defensin 1 gene variability among non-human primates.

Defensins are a recently described family of peptides that play an important role in innate immunity. Recent studies have shown that defensins exhibit a broad spectrum of antimicrobial activities against bacteria and fungi. Three families have been identified so far in mammals, alpha-defensins, beta-defensins and theta-defensins, presumably derived from a common ancestral defensin. A long-term study on the evolution of these multigene families among primates has been undertaken to investigate: (1) the degree of interspecific differentiation; (2) the genetic mechanisms responsible for the variability of these molecules; and (3) the possible role of different environmental factors in their evolution. Nucleotide sequences have been obtained from great and lesser apes, several African and Asian catarrhine monkeys and one New World monkey. A comparison of rates of synonymous and nonsynonymous (amino-acid changing) nucleotide substitution indicates that the primate beta-defensin 1 gene evolved under a pattern of random nucleotide substitution as predicted by the neutral theory of molecular evolution. These results are not consistent with the hypothesis that the primate beta-defensin 1 gene has diversified in response to changes in the microbial species to which a given host is exposed. Analyses of interpecific variability have yielded some insights about the pattern of molecular evolution of the gene among primates. Humans and great apes present high levels of sequence similarity, differing in only one amino acid residue in the mature peptide. Compared with these taxa, hylobatids and cercopithecids exhibit 3-4 amino acid substitutions, some of which increase the net charge of the active molecule.

Animals↗
PubMed2002

Localization of a new highly repeated DNA sequence of Lemur cafta (Lemuridae, Strepsirhini).

We have isolated and cloned an 800-bp highly repeated DNA (HRDNA) sequence from Lemur catta (LCA) and described its localization on LCA chromosomes. Lemur catta HRDNA sequences were localized by performing FISH experiments on standard and elongated metaphasic chromosomes using an LCA HRDNA probe (LCASAT). A complex hybridization pattern was detected. A strong pericentromeric hybridization signal was observed on most LCA chromosomes. Chromosomes 7 and 13 were lit in pericentromeric regions, as well as in the interspersed heterochromatin. Chromosomes 1, 3, 4, 17, 19, X, and microchromosomes (20, 25, 26, and 27) showed no signals in the pericentromeric region, but chromosomes 3 and 4 showed a positive hybridization in heterochromatic regions. The 800-bp L catta HRDNA was species specific. We performed FISH experiments with the LCASAT probe on Eulemur macaco macaco (EMA) and Eulemur fulvus fulvus (EFU) metaphases and no positive signal of hybridization was detected. These findings were also confirmed by Southern blot analysis and PCR.

Animals↗
PubMed2001

AGXT gene mutations and their influence on clinical heterogeneity of type 1 primary hyperoxaluria.

Primary hyperoxaluria type 1 (PH1) is an autosomal recessive disorder that is caused by a deficiency of alanine: glyoxylate aminotransferase (AGT), which is encoded by a single copy gene (AGXT). Molecular diagnosis was used in conjunction with clinical, biochemical, and enzymological data to evaluate genotype-phenotype correlation. Twenty-three unrelated, Italian PH1 patients were studied, 20 of which were grouped according to severe form of PH1 (group A), adult form (group B), and mild to moderate decrease in renal function (group C). All 23 patients were analyzed by using the single-strand conformation polymorphism technique followed by the sequencing of the 11 AGXT exons. Relevant chemistries, including plasma, urine and dialyzate oxalate and glycolate assays, liver AGT activity, and pyridoxine responsiveness, were performed. Both mutant alleles were found in 21 out of 23 patients, and 13 different mutations were recognized in exons 1, 2, 4, and 10. Normalized AGT activity was lower in the severe form than in the adult form (P < 0.05). Double heterozygous patients presented a lower age at the onset of the disease (P = 0.025), and they were more frequent in group A (75%) than in the group B (14%; P = 0.0406). The T444C mutation was more frequent in the severe form (P < 0.05), and the opposite was observed for G630A (P < 0.05). G630A mutation homozygotes had a higher AGT residual activity (P = 0.00001). This study confirms the allelic heterogeneity of the AGXT, which could to some extent be responsible for the phenotypic heterogeneity in PH1.

Adolescent↗