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Abalo Chango

Publications and source records attributed to Abalo Chango.

5 recordsLinked to original sources
PubMed2006

Quantitative methylation-sensitive arbitrarily primed PCR method to determine differential genomic DNA methylation in Down Syndrome.

Relative levels of DNA hypermethylation were quantified in DS individuals using a new method based on a combination of methylation-sensitive arbitrarily primed polymerase chain reaction (MS-AP-PCR) and quantification of DNA fragments with the Agilent 2100 bioanalyzer. Four of the DS individuals had low plasma total homocysteine (tHcy) level (4.3 +/- 0.3 micromol/l) and 4 other had high-tHcy level (14.1 +/- 0.9 micromol/l). Eight healthy control individuals were matched to the DS cases for age, sex, and tHcy levels. We have identified and quantified six hypermethylated fragments. Their sizes ranged from 230-bp to 700-bp. In cases and controls, low-tHcy did not affect methylation level of identified fragments, mean methylation values were 68.0 +/- 39.7% and 52.1 +/- 40.3%, respectively. DNA methylation in DS individuals did not change significantly (59.7+/-34.5%) in response to high-tHcy level in contrast to controls (23.4 +/- 17.7%, P = 0.02). Further, the quantitative MS-AP-PCR using this microfludic system is a useful method for determining differential genomic DNA methylation.

Adolescent↗
PubMed2005

Toxicokinetics and toxicodynamics of ochratoxin A, an update.

Ochratoxin A (OTA) is a mycotoxin produced by fungi of two genera: Penicillium and Aspergillus. OTA has been shown to be nephrotoxic, hepatotoxic, teratogenic and immunotoxic to several species of animals and to cause kidney and liver tumours in mice and rats. Because of differences in the physiology of animal species, wide variations are seen in the toxicokinetic patterns of absorption, distribution and elimination of the toxin. Biotransformation of OTA has not been entirely elucidated. At present, data regarding OTA metabolism are controversial. Several metabolites have been characterized in vitro and/or in vivo, whereas other metabolites remain to be characterized. Several major mechanisms have been shown as involved in the toxicity of OTA: inhibition of protein synthesis, promotion of membrane peroxidation, disruption of calcium homeostasis, inhibition of mitochondrial respiration and DNA damage. The contribution of metabolites in OTA genotoxicity and carcinogenicity is still unclear. The genotoxic status of OTA is still controversial because contradictory results were obtained in various microbial and mammalian tests, notably regarding the formation of DNA adducts. More recent studies are focused on the OTA ability to disturb cellular signalling and regulation, to modulate physiological signals and thereby to influence cells viability and proliferation. The present paper offers an update on these different issues. In addition since humans and animals are likely to be simultaneously exposed to several mycotoxins, especially through their diet, the little information available on the combined effects of OTA and other mycotoxins has also been reviewed.

Animals↗
PubMed2005

No association between common polymorphisms in genes of folate and homocysteine metabolism and the risk of Down's syndrome among French mothers.

The cause of the non-disjunction leading to trisomy 21 remains unclear. Recent evidence has suggested that 5,10-methylenetetrahydrofolate reductase (MTHFR) and/or methionine synthase reductase (MTRR) might contribute to the maternal risk of trisomy 21. The purpose of the present study was to analyse these findings among the French population and to investigate whether common polymorphisms in genes of the folate and homocysteine pathway, including the MTHFR 677C > T, MTHFR 1298A > C, the methionine synthase (MTR) 2756A > G, the cystathionine beta-synthase (CBS) 844Ins68 and the reduced folate carrier (RFC-1) 80G > A polymorphisms, contribute to the risk of trisomy 21. The risk was studied by analysing independent and combined genotypes in 119 case mothers and 119 control mothers. The MTHFR 677T, MTHFR 1298C, MTR2756G, MTRR66G, CBSIns68+ and the RFC-1 80G allele frequencies were not significantly different among French case mothers, compared with control mothers. The risk of having a child with trisomy 21 did not appear to be linked to polymorphisms in genes associated with folate and homocysteine metabolism.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed2004

Homocysteine concentrations in adults with trisomy 21: effect of B vitamins and genetic polymorphisms.

BACKGROUND: The effects of supplementation with B vitamins and of common polymorphisms in genes involved in homocysteine metabolism on plasma total homocysteine (tHcy) concentrations in trisomy 21 are unknown. OBJECTIVES: We aimed to determine the effects of orally administered folic acid and of folic acid combined with vitamin B-12, vitamin B-6, or both on tHcy in adults with trisomy 21. The study was also intended to analyze the possible influence of gene polymorphisms. DESIGN: One hundred sixty adults with trisomy 21 and 160 healthy, unrelated subjects aged 26 +/- 4 y were included. Plasma tHcy, red blood cell folate, serum folate, and vitamin B-12 were measured. Genotyping for the common methylenetetrahydrofolate reductase (MTHFR) 677C-->T, MTHFR 1298A-->C, cystathionine beta-synthase 844Ins68, methionine synthase 2756A-->C, methionine synthase reductase 66A-->G, and reduced folate carrier 80G-->A polymorphisms was carried out. RESULTS: The mean tHcy concentration (9.8 +/- 0.7 micromol/L) of cases who did not use vitamins was not significantly different from that of controls (9.4 +/- 0.3 micromol/L). Plasma tHcy concentrations (7.6 +/- 0.3 mmol/L) in cases who used folic acid were significantly lower than in cases who did not. Folic acid combined with vitamin B-12 did not significantly change tHcy concentrations compared with those in cases who used only folic acid. Folic acid combined with vitamins B-6 and B-12 significantly lowered tHcy (6.5 +/- 0.5 micromol/L). The difference in tHcy according to MTHFR genotype was not significant. However, tHcy concentrations were slightly higher in TT homozygotes among the controls but not among the cases. CONCLUSION: This study provides information on the relation between several polymorphisms in genes involved in homocysteine and folate metabolism in adults with trisomy 21.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗