Biomedical subjects

T Tatu

Publications and source records attributed to T Tatu.

4 recordsLinked to original sources

PubMed2001

Automated genotyping for accurate assignment of the (AT)xNz(AT)y motif within the beta-globin locus control region-hypersensitive site 2.

Within the core region of hypersensitive site 2 of the beta-globin locus control region is the (AT)xNz(AT)y motif, which comprises two short tandem repeats of dinucleotide (AT) interrupted by a short variable DNA sequence (Nz). The motif is usually investigated using direct sequence analysis of specifically amplified DNA, but without family studies, phase alignment of the two tandem repeats, occasionally confounded by a variable N sequence in between, can be erroneous. We combined the technique of automated genotyping with direct sequence analysis to demonstrate that it is possible to overcome this problem; the approach should be applicable for the investigation of other sequence repeats of this nature.

Alleles↗

PubMed2000

Genetic influences on F cells and other hematologic variables: a twin heritability study.

To assess the relative contribution of genetic factors in the variation of F cells (FC) and other hematologic variables, we conducted a classical twin study in unselected twins. The sample included 264 identical (monozygotic [MZ]) twin pairs and 511 nonidentical (dizygotic [DZ]) same-sex twin pairs (aged 20 to 80 years) from the St. Thomas' UK Adult Twin Register. The FC values were distributed continuously and positively skewed, with values ranging from 0.6% to 22%. FC values were higher in women than in men and decreased with age, with the variables accounting for 2% of the total FC variance. The intraclass correlations of FC values were higher in MZ (rMZ = 0.89) than in DZ (rDZ = 0.49) twins. The XmnI-(G)gamma polymorphism in the beta-globin gene cluster had a significant effect on FC levels, accounting for approximately 13% of the total FC variance. Variance components analysis showed that the FC values were accounted for predominantly by additive genetic and nonshared environmental influences, with an estimate of heritability of 0.89. Hemoglobin levels and red blood cell, white blood cell, and platelet numbers were also substantially heritable, with heritability estimates of 0.37, 0.42, 0.62, and 0.57, respectively. Previously, studies of sib pairs with sickle cell disease and isolated family studies showed that high levels of Hb F and FC tend to be inherited. Here, our classical twin study demonstrated that the variance of FC levels in healthy adults is largely genetically determined. (Blood. 2000;95:342-346)

Adult↗

PubMed1997

Hemoglobin typing by high performance liquid chromatography.

To evaluate the potential application of high performance liquid chromatography or HPLC in performing hemoglobin typing, comparison between this technique and routine methods was carried out. Blood specimens from Pediatric Hematology Unit, Research Center, Faculty of Medicine, Ramathibodi Hospital were examined by these methods. The level of Hb A2, Hb E and Hb F were compared. Hb A2 level determined by HPLC and electrophoresis was statistically significantly different but correlated well. Good correlation was found between Hb A2 level from HPLC compared with microcolumn chromatography although there was a statistical difference. No difference but very good correlation was found between the level of Hb E from HPLC compared with electrophoresis. Statistical difference was encountered when Hb F level determined by HPLC was compared to that determined by Betke alkaline denaturation test. However, good correlation was observed when the level of Hb F was greater than 2.0%. In conclusion, HPLC could be an alternative way of performing hemoglobin typing provided that Hb F is 10% or more, by calculating from the equation: Alk F = (0.83 x Hb F by HPLC) - 0.98.

Blood Grouping and Crossmatching↗

PubMed1997

Zinc and copper status of thalassemic children.

We investigated the amount of both zinc and copper in plasma, erythrocytes and hair in 11 patients with hemoglobin H disease, 59 patients with beta-thalassemia/HbE disease and 20 patients with homozygous beta-thalassemia. Plasma and hair zinc levels were found to be much lower, but erythrocyte zinc levels were higher, in thalassemic patients than in controls. The levels of copper in both plasma and erythrocytes were higher in the patients than in the controls. The mechanism with respect to the increase of the amount of both zinc and copper in erythrocytes was not clear; this result may reflect the impairment of zinc and copper utilization in tissues in the pathogenesis of these thalassemic patients.

Adolescent↗