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Suthat Fucharoen

Publications and source records attributed to Suthat Fucharoen.

At least 19 recordsLinked to original sources
PubMed2007

Characterization of a novel deletion causing (deltabeta)0-thalassemia in a Thai family.

A novel deletion of the human beta-globin gene cluster associated with the increased level of fetal hemoglobin (Hb F) in adult life has been demonstrated in a Thai family. A Thai girl who was mistakenly diagnosed as beta-thalassemia/HbE is found to be the compound heterozygote of this mutation and Hb E. The heterozygous father had mild hypochromic and microcytic red blood cells and a high level of Hb F (23.2%). Polymorphic restriction sites in the beta-globin gene cluster identified the homozygous alleles, which localized the deletion region between the psibeta-globin and the 3' beta-globin genes. DNA polymerase that can amplify a long DNA template was employed to examine DNA fragment encompassing this deletion. A 11.3 kilobases (kb) of DNA deletion, beginning approximately 3.1 kb 5' to the delta-globin gene and end in the intron 2 of the beta-globin gene was detected. DNA analysis revealed that this is a case of (deltabeta)(0)-thalassemia with a novel mutation, which can lead to a mild form of beta-thalassemia upon interaction with Hb E.

Adult↗
PubMed2006

Effects of combined UDP-glucuronosyltransferase (UGT) 1A1*28 and 1A6*2 on paracetamol pharmacokinetics in beta-thalassemia/HbE.

In addition to pathophysiological changes, genetic variations can alter drug pharmacokinetics in patients with thalassemia. Numerous drugs are metabolized by UDP-glucuronosyltransferases (UGT) including paracetamol (PCM), a widely used analgesic. Co-occurrence of the UGT1A1 polymorphism (UGT1A1*28) and the UGT1A6 polymorphism (UGT1A6*2) may affect PCM glucuronidation. To elucidate the effect of these combined polymorphisms on the PCM metabolism in thalassemic patients, 15 beta-thalassemia/hemoglobin E subjects with three different UGT1A genotypes received a single oral dose of 1,000 mg PCM. Drug disposition was determined by HPLC. Patients who have UGT1A6*2 without UGT1A1*28 showed a significant, lower area under concentration-time curve (AUC(0)-->infinity) of PCM, PCM-glucuronide and PCM-sulfate than those of the patients with wild-type UGT1A1 and UGT1A6 (p < 0.05). In addition, a high elimination rate constant and clearance of PCM and its metabolites were also found in these patients (p < 0.05). Ourstudy suggests that a subtherapeutic level of PCM may occur in patients who have UGT1A6*2 without UGT1A1*28.

Acetaminophen↗
PubMed2006

Lipid fluidity at different regions in LDL and HDL of beta-thalassemia/Hb E patients.

Atherosclerosis-related vascular complications in beta-thalassemia/hemoglobin E (beta-thal/Hb E) patients may result from iron induced oxidation of lipoproteins. To identify the specific site of oxidative damage, changes in lipid fluidity at different regions in LDL and HDL particle were investigated using two fluorescence probes and two ESR spin probes. The magnitude of increased lipid fluidity in thalassemic lipoproteins was dependent on the location of the probes. In hydrophobic region, the rotational correlation times for 16-doxyl stearic acid and DPH anisotropy were markedly changed in LDL and HDL of the patients. In the surface region, there was only a slight change in the order parameter (S) for 5-doxyl stearic acid and TMA-DPH anisotropy. Lipid fluidity at the core of LDL and HDL showed good correlation with oxidative stress markers, the ratio of CL/CO, and the level of alpha-tocopherol, suggesting that hydrophobic region of thalassemic lipoprotein was a target site for oxidative damage.

Adult↗
PubMed2006

A pharmacokinetic study of paracetamol in Thai beta-thalassemia/HbE patients.

BACKGROUND: Thalassemia may alter the pharmacokinetics of several drugs in thalassemic patients. Paracetamol is a commonly used analgesic and antipyretic drug which is extensively metabolized in the liver via glucuronidation. The aim of this study was to compare the pharmacokinetics of paracetamol (PCM) and its metabolites [paracetamol glucuronide (PCM-G), paracetamol sulfate (PCM-S), and paracetamol cysteine (PCM-C)] in 16 patients with 16 normal subjects. METHOD: Following an overnight fast, a single dose of paracetamol (1,000 mg of Tylenol(R)) was given and blood samples were obtained at predose, 0.5, 1, 1.5, 2, 3, 4, 5, 7, and 9 h after dosing for determination of the plasma levels of PCM and its metabolites by high-performance liquid chromatography. RESULTS: There was no significant difference in maximum concentration of PCM between groups. However, a significantly shorter elimination half-life of PCM was observed in the thalassemic subjects (p<0.001). Total apparent clearance of PCM was significantly faster in thalassemic subjects (p<0.01) while the apparent volume of distribution of PCM did not change. The area under the concentration time curve (AUC(0->infinity)) of PCM-G and PCM-S increased in thalassemic subjects (p<0.05) whereas this parameter for PCM-C was slightly lower in the patients. The half-lives of PCM metabolites were significantly shorter (p<0.01) in thalassemic subjects. CONCLUSION: The results indicate that the elimination of PCM and its metabolites in thalassemic subjects is faster than that in normal subjects. Our pharmacokinetic data provide additional evidence that plasma PCM-G is higher in thalassemic patients with hyperbilirubinemia, which could be a casual relationship in regulating the UDP-glucuronosyltransferase expression.

Acetaminophen↗
PubMed2006

A humanized BAC transgenic/knockout mouse model for HbE/beta-thalassemia.

Hemoglobin E (HbE) is caused by a G-->A mutation at codon 26 of the beta-globin gene, which substitutes Glu-->Lys. This mutation gives rise to functional but unstable hemoglobin and activates a cryptic splice site causing mild anemia. HbE reaches a carrier frequency of 60-80% in some Southeast Asian populations. HbE causes serious disease when co-inherited with a beta-thalassemia mutation. In this study, we report the creation and evaluation of humanized transgenic mice containing the beta(E) mutation in the context of the human beta-globin locus. Developmental expression of the human beta(E) locus transgene partially complements the hematological abnormalities in heterozygous knockout mice ((mu)beta(th-3/+)) and rescues the embryonic lethality of homozygous knockout mice ((mu)beta(th-3/th-3)). The phenotype of rescued mice was dependent on the transgene copy number. This mouse model displays hematological abnormalities similar to HbE/beta-thalassemia patients and represent an ideal in vivo model system for pathophysiological studies and evaluation of novel therapies.

Animals↗
PubMed2006

Hydroxyurea responses and fetal hemoglobin induction in beta-thalassemia/HbE patients' peripheral blood erythroid cell culture.

Due to genetic heterogeneity of beta-thalassemia (beta-thal) patients, several efforts have been undertaken to determine the efficacy of hydroxyurea treatment. The aim of this work is to determine the responder and nonresponder for hydroxyurea treatment in beta-thal intermedia based on gamma-globin mRNA and fetal hemoglobin (HbF) induction in human erythroid progenitor cells purified from a patient's peripheral blood. Eighteen beta-thal/hemoglobin E patients [13 beta(E)/codon41/42(-TCTT), 4 beta(E)/codon17, and 1 beta(E)/IVS-654], requiring blood transfusion occasionally, with Hb levels of 5.20-8.50 g/dl were studied. The relative levels of gamma-globin mRNA was measured by real-time reverse-transcription polymerase chain reaction and HbF by high-performance liquid chromatography. The results indicated that erythroid progenitor cells treated with 30 mumol/l hydroxyurea for 96 h preferentially enhanced (G)gamma-and (A)gamma-globin mRNA. The mean values of (G)gamma-globin mRNA fold induction were higher than (A)gamma-globin mRNA (12+/-4 vs 4+/-0.30), the Pearson's correlation of (G)gamma-and (A)gamma-globin mRNA was r=0.80. Induction of (G)gamma/(A)gamma globin mRNA is up to ninefold. A 30% increase in the proportion of HbF out of the total Hb was found in cultures derived from four patients, 20-30% in cultures from nine patients, and less than 20% in cultures from five patients. In cultures from only two patients, increase in the proportion of HbF was less than 3%, and (G)gamma/(A)gamma globin mRNA is less than 0.50.

Blood Transfusion↗
PubMed2006

Iron-chelating and free-radical scavenging activities of microwave-processed green tea in iron overload.

Secondary iron overload is found in beta-thalassemia (thal) patients because of increased dietary iron absorption and multiple blood transfusions. Excessive iron catalyzes free-radical generation, leading to oxidative damage and vital organ dysfunction. Non-transferrin-bound iron (NTBI) detected in thalassemic plasma is highly toxic and chelatable. Though used to treat iron overload, desferrioxamine (DFO) and deferiprone (L1) also have adverse effects. Green tea (GT) shows many pharmacological effects, particularly antioxidative and iron-chelating capacities. This study was performed to investigate the ability of GT extracts to reduce plasma NTBI concentration and oxidative stress in vitro. The Fe(3+) was found to bind to GT crude extract and form a complex. Green tea crude extract time- and dose-dependently decreased plasma NTBI concentration and counteracted the increase of oxidative stress in both Fe(2+)-EDTA-treated human plasma and erythrocytes. Green tea is a bifunctional natural product that could be relevant for management of iron overload and oxidative stress.

Antioxidants↗
PubMed2006

Single nucleotide polymorphisms and haplotypes of protein C and protein S genes in the Thai population.

Protein C (PC) and protein S (PS) play key roles in an anticoagulant pathway in order to control the haemostatic system. We identified single nucleotide polymorphisms (SNPs) and/or haplotypes in the promotor and exons of the whole PC and PS genes and in the 3'-untranslated region of the PS gene in 55 Thai individuals. The PC gene revealed 10 haplotypes. One synonymous SNP at 2196 was found in the normal Thai population with a minor allele frequency of 4.90%. One homozygous mutation in exon 7, R147W, co-segregated with the synonymous SNP 2196 (homozygote) of the PC gene, resulting in decreased PC activity and antigenic levels. The PS gene revealed three haplotypes with two frequent dimorphisms in exon 15 and the 3'-untranslated region. The most frequent haplotype in the PS gene was H3 (wild type). There was no correlation between the haplotypes of PC and PS genes with functional and antigenic levels of PC and PS.

Adult↗
PubMed2006

The reduction of cholesteryl linoleate in lipoproteins: an index of clinical severity in beta-thalassemia/Hb E.

BACKGROUND: Oxidative modification of lipoproteins has been reported in beta-thalassemia and has been suggested to relate to atherogenesis-risk. This study focused on the change in cholesteryl esters in plasma lipoproteins under oxidative stress resulting from iron overload in beta-thalassemia/hemoglobin E (beta-thal/Hb E) patients. METHODS: Markers of oxidative damage and cholesteryl esters (CEs) were measured in plasma and lipo-proteins from 30 beta-thal/Hb E patients and compared to those from 10 healthy volunteers. CEs in plasma, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) were separated and identified using HPLC. RESULTS: beta-Thal/Hb E patients presented iron overload, a precipitous decrease in alpha-tocopherol and increased lipid peroxidation (thiobarbituric acid-reactive substances; TBARs) in both plasma and lipoproteins. Cholesteryl linoleate, the most abundant CE in lipoproteins, showed a reduction of 70% in LDL, while other CEs showed a lower reduction (50%). An inverse relationship between the cholesteryl linoleate/cholesteryl oleate ratio (CL/CO) and the degree of clinical severity suggested that the CL/CO ratio is an index of damaged lipoproteins and could be used as a pathologic marker of underlying iron overload. Good correlation of non-transferrin-bound iron (NTBI) and TBARs (r=0.8, p<0.01) in LDL strongly supported the contention that iron overload is responsible for initiating the lipid peroxidation in beta-thal/Hb E. CONCLUSIONS: This study suggests that cholesteryl linoleate is the primary target of oxidative modification induced by NTBI in beta-thal/Hb E patients and that reduction in cholesteryl linoleate in lipoproteins could be used as a severity index for beta-thal/Hb E.

Adolescent↗
PubMed2006

Chicken egg yolk antibodies specific for the gamma chain of human hemoglobin for diagnosis of thalassemia.

Immunoglobulin Y (IgY) technology was used to generate anti-hemoglobin Bart's (Hb Bart's) IgY antibodies (Abs) for development into an enzyme-linked immunosorbent assay (ELISA) test for thalassemia diagnosis. Hb Bart's purified from the hemolysate of a patient with Hb Bart's hydrops fetalis (homozygous alpha-thalassemia) was used to immunize a chicken via the pectoralis muscle. After water dilution and sodium sulfate precipitation, 40 to 70 mg of IgY could be extracted from an egg. IgY, first detected in sera 2 weeks after immunization, reached the highest titer at week 4, and the titer remained stable for at least 2 weeks before declining. The pattern of Ab response in the yolk was the same as in the serum but was somewhat delayed. The IgY Abs produced reacted with gamma globin, Hb Bart's, Hb F, normal cord hemolysate (Hbs F plus A), and Hb Bart's hydrops fetalis (Hbs Bart's plus Portland) and to a lesser degree with beta globin, Hb A, Hb A2 and adult hemolysate (Hbs A plus A2), but the Abs did not react with alpha globin. Immunoaffinity purification with Hb A coupled to Sepharose was used to isolate an unbound IgY that reacted with Hb F, Hb Bart's, and gamma globin, and this IgY was used to develop an ELISA test for thalassemia diagnosis. The results of direct ELISA analyses of 336 hemolysate samples from individuals with various known thalassemia genotypes and phenotypes and from healthy individuals confirmed the specificity of the polyclonal Abs for Hbs containing Hb F and Hb Bart's. This specificity, which was due to the Abs' strong reactivity in cases of pathologic thalassemic diseases and weak reactivity in cases of nonpathologic thalassemic diseases, depended on the levels of Hb Bart's and Hb F.

Animals↗
PubMed2006

Molecular mechanism of high hemoglobin F production in Southeast Asian-type hereditary persistence of fetal hemoglobin.

Hereditary persistence of fetal hemoglobin (HPFH) is associated with a high level of hemoglobin F (HbF) synthesis in adult heterozygotes. In this study, 2 of 6 unrelated HPFH Thai families were found to be Southeast Asian-type HPFH (SEA-HPFH) by analyses of the hematologic data and Southern blot hybridization with polymerase chain reaction-amplified DNA probes. DNA mapping with a probe for a delta-globin fragment showed a 27-kb deletion of DNA that included the beta-globin gene and the 3' deoxyribonuclease I hypersensitive site 1 (3'HS1) sequence downstream. Deletion of the insulator, 3'HS1, and the juxta-position of the HPFH-3 core enhancer downstream to the 3' breakpoint have been postulated to be the cause of high HbF production in these individuals. To test this hypothesis, we transfected K562 cells with 4 different bacterial artificial chromosome constructs containing the enhanced green fluorescent protein (EGFP) gene at the position of the Agamma-globin gene (pEBAC/148beta:EGFP). Flow cytometry was used to compare EGFP expression from the pEBAC/148beta:EGFP construct with the HPFH-3 core enhancer immediately 5' to the SEA-HPFH breakpoint (pEnH), from the pEBAC/148beta:EGFP construct with 8 kb of the breakpoint sequence and the HPFH-3 core enhancer (pSEA-HPFH), and from the construct with 3'HS1 followed by the pSEA-HPFH sequence (pSEA-HPFH_3pHS1). The results show that high HbF production in SEA-HPFH occurs from a deletion of the 3'HS1 sequence and the juxtaposition of the HPFH-3 enhancer downstream to the delta-globin gene.

Adolescent↗
PubMed2005

Effect of coenzyme Q10 as an antioxidant in beta-thalassemia/Hb E patients.

Thalassemia is a group of genetic disorders resulting from different mutations in the globin gene complex and leading to an imbalance in globin synthesis. Unmatched globin chains are less stable and susceptible to oxidation. Patients with beta-thalassemia/HbE are prone to increased oxidative stress as indicated by increased lipid peroxidation product, malondialdehyde (MDA), partly because of the presence of iron in the form of heme and hemichromes released from excess globin chains and excess iron deposition in various tissues. The level of antioxidant such as glutathione is markedly decreased while activities of antioxidant enzymes including superoxide dismutase (SOD), catalase, and glutathione peroxidase (GSH-Px) are increased. We have recently found that the levels of coenzyme Q(10) (CoQ(10)) are also very low in thalassemia. We therefore evaluated the oxidative stress and the antioxidants in these patients before and after supplementation with 100 mg CoQ(10) daily for 6 months. The results showed that the plasma level of CoQ(10) significantly increased and the oxidative stress decreased as the level of MDA declined. The administration of CoQ(10) led to significant improvement of biochemical parameters of antioxidant enzymes. The antioxidant supplementation will be beneficial for thalassemia patients as adjunct therapy to increase their quality of life.

Adenosine Triphosphate↗
PubMed2005

In vivo and in vitro studies of fetal hemoglobin induction by hydroxyurea in beta-thalassemia/hemoglobin E patients.

OBJECTIVE: Some, but not all, beta-thalassemia/hemoglobin E (beta-thal/HbE) patients respond to hydroxyurea treatment. It would be helpful if patient responses to hydroxyurea could be screened in vitro to identify responders and nonresponders before beginning in vivo treatment. MATERIALS AND METHODS: Thirteen beta-Thal/HbE patients were treated with hydroxyurea orally for 2 years at a starting dose of 5 mg/kg/day for 5 days/week with escalation to a maximum of 10 mg/kg/day. For comparison, erythroid cells obtained from peripheral blood of the same patients 1 year after they had stopped hydroxyurea treatment were treated with hydroxyurea in vitro. The gamma-globin mRNA was measured by real-time reverse-transcription polymerase chain reaction, fetal hemoglobin (HbF) by high-performance liquid chromatography, (G)gamma- and (A)gamma-globin chains by Triton X-100 acid urea polyacrylamide gel electrophoresis. RESULTS: Treatment of cells in primary culture with 30 microM hydroxyurea for 96 hours significantly increased the fractional HbF content in beta-Thal/HbE patients. The (G)gamma:(A)gamma-globin mRNA was induced 0.30- to 8-fold in vitro and 0.30- to 6-fold in vivo (r(2) = 0.51, p = 0.16 by paired t-test); the fractional HbF content was induced 0.50- to 19-fold in vitro and 0.30- to 12-fold in vivo (r(2) = 0.61, p = 0.20) and the (G)gamma:(A)gamma-globin chain ratio was increased 0.80- to 1.40-fold in vitro and 1- to 1.20-fold in vivo (r(2) = 0.62, p = 0.13). CONCLUSION: The correlation of in vivo and in vitro results of HbF synthesis and globin mRNA suggest that in vitro testing may predict the in vivo response.

Adult↗
PubMed2005

A humanized mouse model for a common beta0-thalassemia mutation.

Accurate animal models that recapitulate the phenotype and genotype of patients with beta-thalassemia would enable the development of a range of possible therapeutic approaches. Here we report the generation of a mouse model carrying the codons 41-42 (-TTCT) beta-thalassemia mutation in the intact human beta-globin locus. This mutation accounts for approximately 40% of beta-thalassemia mutations in southern China and Thailand. We demonstrate a low level of production of gamma-globins from the mutant locus in day 18 embryos, as well as production of mutant human beta-globin mRNA. However, in contrast to transgenic mice carrying the normal human beta-globin locus, 4-bp deletion mice fail to show any phenotypic complementation of the knockout mutation of both murine beta-globin genes. Our studies suggest that this is a valuable model for gene correction in hemopoietic stem cells and for studying the effects of HbF inducers in vivo in a "humanized" thalassemic environment.

Animals↗
PubMed2005

Rescued mice with Hb E transgene-developed red cell changes similar to human beta-thalassemia/HbE disease.

A novel C57BL/6 transgenic murine model of HbE has been developed, and the heterotetrameric ((m)alpha2(h)beta(E)2) hemoglobin shows significant complementation of mild thalassemia phenotype in double heterozygous (beta(m+)beta(m-), beta(hE)) and homozygous knockout (beta(m-)beta(m-), beta(hE)) mice with 100% heterotetrameric hemoglobin. Lethal homozygous beta-thalassemic mice rescued by HbE transgenes mimic beta-thalassemia/HbE phenotype in human. Although anemia was not pronounced, other hematologic parameters were abnormally similar to beta-knockout mice. Flow cytometric study revealed a highly oxidative status in the red cells, but there were no marked changes in PS red cells and RBC vesicles. RBC life span and half-time of rescued red cells were shortened, indicating a rapid RBC destruction.

Animals↗
PubMed2005

Genetic analysis of candidate modifier polymorphisms in Hb E-beta 0-thalassemia patients.

Hemoglobin E (Hb E)-beta-thalassemia patients display a range of clinical severities, from nearly asymptomatic to transfusion-dependent thalassemia major. Given this clinical heterogeneity, additional genetic factors modifying disease severity remain to be discovered. Association studies are being conducted to elucidate the role of genetic polymorphisms as disease severity modifiers in Hb E-beta-thalassemia patients. Using strict scoring criteria, 1060 Hb E-beta-thalassemia patients were categorized into mild, moderate, and severe groups. Taking a candidate gene approach, we found no statistically significant differences between the mild and severe patients groups in allelic or genotypic frequencies for single nucleotide polymorphisms within five genes known to influence globin gene expression and erythropoiesis.

Adolescent↗