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P Winichagoon

Publications and source records attributed to P Winichagoon.

At least 19 recordsLinked to original sources
PubMed2006

Risk of zinc, iodine and other micronutrient deficiencies among school children in North East Thailand.

INTRODUCTION: Micronutrient deficiencies during childhood can contribute to impairments in growth, immune competence, and mental and physical development, and the coexistence of several such deficiencies can adversely affect the efficacy of single micronutrient interventions. OBJECTIVE: To assess the prevalence of zinc and iodine deficiency and their interrelationships with vitamin A deficiency and anemia and associations with socio-economic status, hemoglobin type, and anthropometry in a cross-sectional study. SETTING: A total of 10 primary schools in North East Thailand. METHODS: Non-fasting venipuncture blood samples and casual urine samples were collected from 567 children aged 6-13 years. Anthropometric measures and serum zinc, albumin, C-reactive protein and urinary iodine, are reported here and integrated with published data on vitamin A, anemia, and socio-economic status. RESULTS: Of the children, 57% had low serum zinc and 83% had urinary iodine levels below the 100 microg/l cutoff. Suboptimal serum zinc and urinary iodine concentrations may result from low intakes of zinc and iodized salt. Significant risk factors for low serum zinc were serum retinol <1.05 micromol/l and being male. Those for urinary iodine <100 microg/l were height-for-age score>median and being female. For serum retinol <1.05 micromol/l, risk factors were low hemoglobin, low serum zinc, and <9 years, and for low hemoglobin indicative of anemia risk factors were <9 years, AE hemoglobinopathy, and serum retinol <1.05 micromol/l. Of the children, 60% were at risk of two or more coexisting micronutrient deficiencies, most commonly suboptimal urinary iodine and low serum zinc. CONCLUSION: The findings emphasize the need for multimicronutrient interventions in North East Thailand.

Age Factors↗
PubMed2005

Role of NF-kappa B in regulation of apoptosis of erythroid progenitor cells.

Erythropoietin (EPO) and interferon-gamma (IFN-gamma) added to human erythroid progenitor cells purified from peripheral blood (erythroid colony-forming cells; ECFC) significantly reduces apoptosis as assessed by flow cytometry (FCM) using annexin V. To clarify the role of NF-kappaB in the regulation of the apoptosis of erythroid progenitor cells, cyclosporin A (CsA), which blocks dissociation of the NF-kappaB complex, was added to serum-free cultures of ECFC. CsA induced the apoptosis of ECFCs in the presence of EPO or IFN-gamma, but at different magnitudes. In the presence of a relatively low concentration of CsA (10 microm), apoptosis was induced only in cultures with EPO. The direct involvement of NF-kappaB was then assessed by Western blotting and confocal microscopy. In the presence of EPO, NF-kappaB was abundant both in the cytoplasm and in the nucleus, and nuclear expression was diminished after adding CsA. In contrast, NF-kappaB was undetectable in the nucleus in the presence of IFN-gamma. The effect of CsA on mitochondrial function was investigated by determining the DeltaPsim and reactive oxygen species production. CsA disturbed the transmembrane potential in the presence of either EPO or IFN-gamma, although the viability of the cells was maintained in the presence of IFN-gamma plus CsA. These results indicate that IFN-gamma reduced the apoptosis of erythroid progenitor cells through a unique signaling pathway that is independent of NF-kappaB translocation, and which is not mediated by modulating mitochondrial function, whereas EPO reduced apoptosis through NF-kappaB translocation to the nucleus.

Apoptosis↗
PubMed2002

Screening for the carriers of thalassemias and abnormal hemoglobins at the community level.

Thalassemia and abnormal hemoglobins are common genetic disorders in Southeast Asia. Thalassemia is not only an important public health problem but also a socio-economic problem of many countries in the region. The approach to deal with the thalassemic problem is to prevent and control births of the new cases. This requires an accurate identification of couple at high risk to have a thalassemic child. The diagnosis of thalassemia carriers need several tests that are not practical for screening the population at large. In this study we used two simple laboratory tests to screen for potential thalassemia carriers and hemoglobin E individuals. Three-hundred pregnant women and 40 spouses were recruited in this study. The methods were the red cell osmotic fragility (OF) screening test with 0.36% NaCl and the dichlorophenolindophenol (DCIP) precipitation test to detect Hb E and unstable hemoglobins. Standard methods for red cell indices, hemoglobin analysis and detection of alpha-thalassemia by immunological method were also performed to confirm genotypes of thalassemia. The results showed that 98 women (32.7%) were carriers of thalassemias and hemoglobin E. The number of false positive by OF test was 3.2% and by DCIP test was 0.6%. Sensitivity and specificity of OF test were 89.5% and 93.3%, respectively whereas those of DCIP test were 100%. Of the 40 couples investigated, one was found to be at risk of having beta-thalassemia/Hb E fetus. Screening techniques including one tube osmotic fragility and DCIP precipitation tests are sensitive and specific for the detection of thalassemia and unstable hemoglobins such as Hb E. The techniques are also simple, economic, rapid, and give minimal false negative result.

Adult↗
PubMed2001

Detection of haemoglobin variants and inference of their functional properties using complete oxygen dissociation curve measurements.

Complete oxygen dissociation curves for red cell suspensions of three haemoglobinopathies, namely haemoglobin (Hb) H, Hb Köln and Hb Tak/beta thalassaemia diseases, were measured using automatic recording methods. These curves were left-shifted compared with the normal red cell curve and showed a biphasic shape as a result of co-existence of the high and normal affinity haemoglobin components. Computer-assisted simulation of these biphasic curves enabled us to infer the curves for the pure abnormal haemoglobins and their fraction in the total haemoglobin of the red cell. The inferred values of fraction agreed with those determined by haemoglobin type analysis or the literature values. The curve for Hb Köln red cells deviated from the normal red cell curve in the whole range of oxygen saturation, whereas the curve for Hb H was close to the normal curve at the middle and upper portions. This difference in deviation was ascribed to a possible interaction between Hb Köln and Hb A through subunit exchange, and its absence between Hb H and Hb A. The present results indicate that measurement of the complete oxygen dissociation curve is important for the detection of non-interacting variants such as Hb H and is useful for inferring the functional properties of haemoglobin components that are not easily isolated.

Chromatography, High Pressure Liquid↗
PubMed2001

A multi-center study in order to further define the molecular basis of beta-thalassemia in Thailand, Pakistan, Sri Lanka, Mauritius, Syria, and India, and to develop a simple molecular diagnostic strategy by amplification refractory mutation system-polymerase chain reaction.

The spectrum of the beta-thalassemia mutations of Thailand, Pakistan, India, Sri Lanka, Mauritius and Syria has been further characterized by a multi-center study of 1,235 transfusion-dependent patients, and the mutations discovered used to assess the fidelity of a simple diagnostic strategy. A total of 44 beta-thalassemia mutations were identified either by allele-specific oligonucleotide hybridization, amplification with allele-specific primers, or DNA sequencing of amplified product. The results confirm and extend earlier findings for Thailand, Pakistan, India, Mauritius and Syria. This is the first detailed report of the spectrum of mutations for Sri Lanka. Two novel mutations were identified, codon 55 (-A) and IVS-I-129 (A-->C), both found in Sri Lankan patients. Two beta-thalassemia mutations were found to coexist in one beta-globin gene: Sri Lankan patients homozygous for the beta0 codon 16 (-C) frameshift were also homozygous for the beta+ codon 10 (C-->A) mutation. Studies of Sri Lankan, Pakistani, and Indian carriers suggest the codon 10 (C-->A) mutation is just a rare polymorphism on an ancestral allele, on which the beta0 codon 16 (-C) mutation has arisen. Each country was found to have only a few common mutations accounting for 70% or more of the beta-thalassemia alleles. A panel of primers to diagnose the majority of the mutations by the amplification refractory mutation system was developed, enabling a simple molecular diagnostic strategy to be introduced for each country participating in the multi-center study.

Asia↗
PubMed2000

Clinical and hematologic aspects of hemoglobin E beta-thalassemia.

Hemoglobin E beta-thalassemia is an important cause of childhood chronic disease in Southeast Asia. It is characterized by the presence of hemoglobin E and F, and the amount of hemoglobin E ranges from 35% to 75%. The patients are generally classified as having thalassemia intermedia because they have inherited a beta-thalassemia allele and hemoglobin E, which acts as a mild beta+-thalassemia. However, a remarkable variability in the clinical expression, ranging from a mild form of thalassemia intermedia to transfusion-dependent conditions, is observed. Severe hemoglobin E beta-thalassemia may have clinical features of thalassemia major. Phenotypes of thalassemia major can be predicted from the early onset of clinical symptoms and the requirement of regular blood transfusion from infancy for survival. Coinheritance of alpha-thalassemia alleviated the severity of beta-thalassemia disease in patients with at least one allele of mild beta-thalassemia genotype.

Asia, Southeastern↗
PubMed2000

Relative quantitation of mRNA in beta-thalassemia/Hb E using real-time polymerase chain reaction.

beta-Thalassemia and Hb E patients, with seemingly identical genotypes, have a remarkable variability in severity. Reduction in red cell survival in beta-thalassemia is correlated with the amount of intracellular unmatched alpha-globin chains. However, it was only recently realized that mRNA, whose translation is prematurely terminated, is also unstable. No systematic attempts have been made to investigate mRNA stability in beta-thalassemia arising from nonsense mutations located upstream from the normal termination codon. In this study, one-step real-time polymerase chain reaction has been employed to compare the levels of alpha- and beta-globin mRNA in reticulocytes from beta-thalassemia/Hb E subjects. The results showed the highest alpha/beta-globin mRNA ratio (median = 5.70, n = 13) in frameshift codons 41/42 (-TTCT)/Hb E individuals compared to normal subjects (median = 1.02, n = 6), or those with Hb E trait (median = 2.15, n = 8). In addition, there was a concomitant increase in the alpha/beta-globin mRNA ratio with decrease in hemoglobin level, i.e., increase in severity. The difference in the ratio among beta-thalassemia/Hb E patients with the same genotype may be attributed to individual variations of efficiency in betaE-globin mRNA splicing and in the destruction of prematurely terminated mRNA.

Adult↗
PubMed1999

Prenatal diagnosis of beta-thalassaemia by reverse dot-blot hybridization.

Thalassaemia is the most common genetic disease and is a public health problem of Thailand. Prevention and control of beta-thalassaemia diseases need accurate diagnosis of carriers and proper genetic counselling. Prenatal diagnosis is needed to prevent birth of the thalassaemic offspring in the couple at risk. This can be performed in the first trimester of pregnancy by DNA analysis using the polymerase chain reaction (PCR). Since there are more than 20 mutations causing beta-thalassaemia in Thailand, the point mutation detection by reverse dot-blot allele-specific oligonucleotide (ASO) hybridization was developed using two sets of ASO probes. The first battery of ASO probes has been designed to detect 10 common beta-globin gene mutations including codon 26, G->A (Hb E): codons 41/42, -TCTT; codon 17, A->T; IVS 2 nt 654, C->T; IVS 1 nt 1, G->T; IVS 1 nt 5. G->C; codon 19, A->G (Hb Malay); codon 35, C->A; codons 71/72, +A and -28 ATA, A->G. The second set of ASO probes detect 14 uncommon beta-thalassaemia mutations. We applied this reverse dot-blot hybridization technique to perform prenatal diagnosis in 105 pregnancies at risk of having severe beta-thalassaemia diseases. 36 fetuses (34 per cent) were found to be affected with homozygous beta-thalassaemia or beta-thalassaemia/Hb E disease in which one was twin pregnancy. The others included 31 fetuses with heterozygous beta-thalassaemia, 22 heterozygous Hb E, 1 homozygous Hb E and 16 normal fetuses. The common set of ASO probes detected about 95 per cent of cases which suggests that prenatal diagnosis for beta-thalassaemia disease can be easily carried out by this approach.

DNA Primers↗
PubMed1999

Standardization on laboratory diagnosis of thalassemia and abnormal hemoglobin.

Thalassemia is one of the most common single gene disorders. The geographic distribution of thalassemia and abnormal hemoglobin has been known for many years. A worldwide significant spread of these abnormal genes, especially from Southeast Asia, occurred in the last two decades. This has resulted in a dramatic increase of Hb E disorders and various Southeast Asian thalassemia genotypes, which means that requests for hemoglobinopathy investigations are likely to increase in many laboratories worldwide. Hemoglobinopathy screening and diagnosis may need to be undertaken antenatally, neonatally and in certain hematological situations. The introduction of automation for hemoglobinopathy screening, including the automated cell counting and HPLC system, is an important advance in technology for hematology laboratories. The instruments need to be calibrated and standardized to get an accurate data for interpretation. Internal and external control samples are also needed. Combination of test results is usually required to achieve a proper diagnosis, which in turn, provide a self-check for each laboratory test.

Adult↗
PubMed1999

Detection and structural analysis of abnormal hemoglobins found in Thailand.

In Thailand, some 20 different abnormal hemoglobins have been found in the last 30 years. Most are rare except for Hb E and Hb Constant Spring, found with frequencies of 10-53% and 1-8% respectively in different parts of the country. Most mutations are point mutations, but C-terminal elongations and crossing-over are also found. Most mutations do not cause clinical problems, but some can give rise to mild thalassemia syndromes, or cause problems in association with thalassemia. Abnormal hemoglobins may often be diagnosed by electrophoresis, but some variants have the same mobility, so that other techniques are required, such as HPLC and the use of allele-specific polymerase reaction or oligonucleotide probes. Novel variants, not previously described in Thailand, require structural analysis at the protein and DNA level.

Chromatography, High Pressure Liquid↗
PubMed1998

Detection of zeta-globin chains in the cord blood by ELISA (enzyme-linked immunosorbent assay): rapid screening for alpha-thalassemia 1 (Southeast Asian type).

Fetuses with homozygous alpha-thalassemia 1, in which the deletion of all four alpha-globin genes results in the absence of any alpha-globin chains, are severely anemic with clinical features of hydrops fetalis. Definitive diagnosis of alpha-thalassemia 1 carriers is difficult since there are few red cell abnormalities. Recently Chui et al. found that minute amounts of embryonic zeta-globin chains are present in adult hemoglobin of the Southeast Asian type of alpha-thalassemia 1 carriers. In this study, we screened 521 cord bloods for alpha-thalassemia 1. Hemoglobin analysis, including quantitation of Hb Bart's, was performed using the automated HPLC, alpha-thalassemia short program (VARIANT, Bio-Rad, Hercules, CA). Of these, 200 cord blood samples in which Hb Bart's was demonstrated were tested for the presence of zeta-globin chains by ELISA using labeled anti-zeta monoclonal antibody. Zeta-globin ranged between 0.21 and 0.83% in 19 specimens carrying alpha-thalassemia 1 gene. In the remaining 90 out of 109 specimens in which Hb Bart's was greater than 1.2%, zeta-globin was less than 0.17%. DNA analysis revealed the presence of normal alpha-genotype and other types of alpha-thalassemia including alpha-thalassemia 2 and Hb Constant Spring. One false positive was found in which the zeta-globin was 0.25% by ELISA but in which PCR indicated an alpha-thalassemia 2 heterozygote. Ninety-one samples with Hb Bart's of less than 1.2% by HPLC are most likely normal with a zeta-globin range between 0 and 0.14%. This study also showed that the frequency of alpha-thalassemia 1 in Bangkok is 3.65%.

Adult↗
PubMed1998

Molecular basis of beta-thalassemia in the Maldives.

We have systematically analyzed beta-thalassemia genes using polymerase chain reaction-related techniques, dot-blot hybridization with oligonucleotide probes, allele specific-polymerase chain reaction, and sequencing of amplified DNA fragments from 41 unrelated patients, including 37 beta-thalassemia homozygotes, three with beta-thalassemia/Hb E, and one with beta-thalassemia/Hb S. Four different beta-thalassemia mutations were detected in 78 alleles. These are the IVS-I-5 (G-->C), codon 30 (AGG-->ACG) [also indicated as IVS-I (-1)], IVS-I-1 (G-->A), and codons 41/42 (-TTCT) mutations. The distribution of the beta-thalassemia mutations in the Maldives is 58 alleles (74.3%) with the IVS-I-5 (G-->C) mutation, 12 (15.4%) with the codon 30 (AGG-->ACG) mutation, seven (9%) with the IVS-I-1 (G-->A) mutation, and one with the codons 41/42 (-TTCT) mutation. The first three mutations account for 98.7% of the total number of beta-thalassemia chromosomes studied. These mutations are clustered in the region spanning 6 bp around the junction of exon 1 and the first intervening sequence of the beta-globin gene. These observations have significant implications for setting up a thalassemia prevention and control program in the Maldives. Analysis of haplotypes and frameworks of chromosomes bearing each beta-thalassemia mutation suggested that the origin and spread of these mutations were reflected by the historical record.

Algeria↗
PubMed1998

Prenatal and postnatal diagnoses of thalassemias and hemoglobinopathies by HPLC.

The conventional approach to qualitative and quantitative analyses of hemoglobin (Hb) molecules for the diagnoses of hemoglobinopathies requires a combination of tests. We used an automated HPLC (VARIANT) system to study alpha-thalassemia and beta-thalassemia syndromes in Thailand. The beta-thalassemia short program is applicable to the diagnosis of alpha-thalassemia and beta-thalassemia disorders, including Hb H, EA Bart's disease, and EF Bart's disease, in adults, newborns, and fetuses. The system cannot quantify accurately certain Hb molecules, such as Hb H and Hb Bart's. The alpha-thalassemia short program was therefore developed and used to quantify Hb Bart's to detect alpha-thalassemia genotypes in cord blood. This automated HPLC system is an alternative approach to the diagnosis of complicated thalassemia syndromes in Thailand and Southeast Asia.

Adult↗