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S Fucharoen

Publications and source records attributed to S Fucharoen.

At least 19 recordsLinked to original sources
PubMed2001

Molecular characterization of hemoglobin C in Thailand.

We describe hematologic and DNA characterization of 12 hemoglobin C heterozygotes and three compound heterozygotes for hemoglobin C and hemoglobin E found in Thailand. Amplification and DNA analysis of genomic DNA by the polymerase chain reaction procedure permitted the identification of the beta(C) mutation at codon 6 of beta-globin gene (beta 6; GAG-AAG). beta-Globin gene haplotype analysis demonstrated that all beta(C) globin genes detected in these Thai individuals were associated with the haplotype (+ - - - - - +), indicating a non-African origin of this abnormal hemoglobin in Thailand. On routine hemoglobin typing, hemoglobin C is usually mistakenly identified as hemoglobin E because of theirs similar mobilities on cellulose acetate electrophoresis. The simple DNA assay for hemoglobin C based on an allele-specific polymerase chain reaction for accurate diagnosis of hemoglobin C was therefore developed.

Adult↗
PubMed2001

Mitochondrial DNA polymorphisms in Thailand.

Nucleotide sequences of the D-loop region of human mitochondrial DNA from six small ethnic groups of Thailand i.e., Hill tribes (Lisu and Mussur), Phuthai, Lao Song, Chong, and aboriginal Sakai, were analyzed. The sequences were compared with those of native Thai populations from two provinces, Chiang Mai and Khon Kaen. Based on a comparison of the 563-bp sequences in 215 Thai individuals, 137 different sequence types were observed. Of these, 124 were unique to their respective populations, whereas 13 were shared between two to five populations. The intergenic COII/tRNALys 9-bp deletion was observed in every Thai population examined, except for the Sakai, with varying frequencies ranging from 18% to 40%. The D-loop sequences variation, and phylogenetic analysis, suggested that the 9-bp deletion had occurred in a very ancient ancestry of Southeast Asians, although multiple origins of the deletion cannot be ruled out. Genetic distances, based on net nucleotide diversities, between populations revealed that the Sakai were distantly related to the other Thai populations, while the Lao Song and Chong were closely related to each other. Close genetic affinities were also observed among the Hill tribes, Phuthai, and native northeast Thai (Khon Kaen), indicating that they may share some degree of the common ancestral maternal lineages.

Base Sequence↗
PubMed2001

Simultaneous PCR detection of beta - thalassemia and alpha - thalassemia 1 (SEA type) in prenatal diagnosis of complex thalassemia syndrome.

OBJECTIVE: To establish a rapid PCR method for simultaneous detection of beta-thalassemia and alpha-thalassemia 1 genes for diagnosis of complex alphabeta-thalassemia syndrome. DESIGN AND METHODS: Using multiplex allele specific PCR approach, we evaluated a simultaneous detection of the SEA type alpha-thalassemia 1 and the common Southeast Asian beta-thalassemia and hemoglobin E genes. The system was tested on known cases of double heterozygote for alpha- and beta-thalassemias and in a prenatal diagnosis of complex alphabeta-thalassemia syndrome. RESULTS: Co-inheritance of alpha-thalassemia 1 (SEA type) with each of the common beta-thalassemia genes in Southeast Asian and with hemoglobin E could be identified in a single PCR reaction. A successful application of this simultaneous detection system in prenatal diagnosis of a complex thalassemia syndrome caused by an EFBart's disease was demonstrated in a Thai family. CONCLUSION: We have shown that correct diagnosis of double heterozygosity for alpha-thalassemia 1 and beta-thalassemia or hemoglobin E could be obtained using a simultaneous multiplex PCR. These rapid PCR assays would facilitate characterization and prenatal diagnosis of complex thalassemia syndromes in the regions where both alpha- and beta-thalassemias and hemoglobin E are common.

Chorionic Villi Sampling↗
PubMed2001

Clinical and hematological features of codon 17, A-T mutation of beta-thalassemia in Thai patients.

Forty-one patients with codon 17, A-T mutation of beta-thalassemia, which is commonly found in Thailand, were studied to determine whether it is possible to predict phenotypic severity from genetic factors. The clinical phenotype of homozygotes for codon 17, A-T and compound heterozygotes for codon 17, A-T and beta+-thalassemia may be used to predict a severe phenotype with TM. However, the clinical phenotype of compound heterozygotes for codon 17, A-T and beta+-thalassemia or Hb E were variable and could not be accurately predicted. The association of alpha-thalassemia2 and milder disease was and was not evident in patients with codon 17, A-T and Hb E. The association between Hb CS gene or the presence of XmnI-Ggamma polymorphism and a mild clinical phenotype is not apparent, indicating the involvement of other ameliorating determinants or genetic modifications.

Age of Onset↗
PubMed2001

Atypical hemoglobin H disease in a Thai patient resulting from a combination of alpha-thalassemia 1 and hemoglobin Constant Spring with hemoglobin J Bangkok heterozygosity.

A case of hemoglobin H disease in combination with hemoglobin Constant Spring and a beta-globin chain variant is reported in a 3-yr-old Thai girl. On routine cellulose acetate electrophoresis, one abnormal band in addition to the hemoglobins A, A2, H, Bart's and Constant Spring was detected. The amount of this abnormal band movement towards more anodic to the hemoglobin A was 35.7%. DNA analysis of the alpha-globin gene cluster by polymerase chain reaction (PCR) revealed a combination of defects caused by the SEA-type alpha-thalassemia 1 and the alpha-Constant Spring gene. Analysis of beta-globin gene by PCR and DNA sequencing also detected the heterozygosity for the GGC-GAC mutation at codon 56, leading to a substitution of aspartic acid for glycine resulting in the hemoglobin J Bangkok. The hematologic data of this unusual case of hemoglobin H disease are presented and compared with two compound heterozygotes for hemoglobin J Bangkok and alpha-thalassemia 1 found in the patient's father and grandfather. A simple DNA assay based on an allele-specific PCR for rapid diagnosis of the hemoglobin J Bangkok is also described.

Child, Preschool↗
PubMed2001

Clinical and hematological features of beta(+)-thalassemia (IVS-1 nt 5, G-C mutation) in Thai patients.

Seventy-eight patients with IVS-1 nt 5, G-C, which is the common mutation of beta+-thalassemia found in the southern part of Thailand, were studied to determine whether it is possible to predict phenotypic severity from genetic factors. The clinical phenotype of homozygotes for IVS-1 nt 5, G-C and compound heterozygotes for IVS-1 nt 5, G-C and beta(0) - or beta(+)-thalassemia were variable and could not be accurately predicted. The associations between concomittant alpha-thalassemia or Hb CS or the presence of XmnI-Ggamma polymorphism and a mild clinical phenotype are not apparent, indicating the involvement of other ameliorating determinants or genetic modifications.

Adolescent↗
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

Rapid differentiation of five common alpha-thalassemia genotypes by polymerase chain reaction.

The alpha-thalassemias are common genetic disorders that arise from reduced synthesis of the alpha-globin chains. At present, large-scale carrier screening and clinically valuable antenatal detection programs have not been established for the congenital disorder alpha-thalassemia (alpha-thal). We have developed a simple nonradioactive polymerase chain reaction (PCR) approach that can detect and differentiate several common alpha-globin gene deletional alpha-thals regardless of the break points. When three primer sets were used--two gene-specific sets for the alpha1- and alpha2-globin genes and one set for the beta-actin gene (serving as an internal control)--PCR products from genomic DNA were simultaneously amplified and analyzed after coamplification and gel electrophoresis. The number of alpha-globin genes present in the subjects was determined by the intensity of alpha1 and alpha2 bands normalized with that of beta-actin when using densitometry. Our results demonstrate that five common genotypes of deletional alpha-thal are differentiated by the ratios of alpha1/beta-actin and alpha2/beta-actin. We also examined the feasibility of coupling this allele-specific amplification to a color-complementary assay. This easy and reproducible PCR assay is suitable for identifying alpha-thal carriers in screenings of large populations and improving genetic counseling.

Actins↗
PubMed2001

Major hematologic diseases in the developing world- new aspects of diagnosis and management of thalassemia, malarial anemia, and acute leukemia.

The three presentations in this session encompass clinical, pathophysiological and therapeutic aspects of hematologic diseases which impact most heavily on developing world countries. Dr. Victor Gordeuk discusses new insights regarding the multi-faceted pathogenesis of anemia in the complicated malaria occurring in Africa. He describes recent investigations indicating the possible contribution of immune dysregulation to this serious complication and the implications of these findings for disease management. Dr. Surapol Issaragrisil and colleagues describe epidemiologic and clinical characteristics of the thalassemic syndromes. In addition to being considered a major health problem in Southeast Asia, the migration throughout the world of people from this region has caused the disease to have global impact. A unique thalassemia variant, Hb Ebeta-thalassemia, with distinctive clinical features, has particular relevance for this demographic issue. Special focus will be reported regarding recent prenatal molecular screening methods in Thailand which have proven useful for early disease detection and disease control strategies. Dr. Raul Ribeiro describes a clinical model for providing effective treatment for a complex malignancy (childhood acute lymphoblastic leukemia) in countries with limited resources. With the multidisciplinary approach in Central American of the joint venture between St. Jude Children's Research Hospital International Outreach Program and indigenous health care personnel, major therapeutic advances for this disease have been achieved. Given the major demographic population shifts occurring worldwide, these illnesses also have important clinical implications globally. These contributions demonstrate that lessons learned within countries of disease prevalence aid our understanding and management of a number of disorders prominently seen in developed countries. They will show how effective partnerships between hematologists in more and less developed nations may work together to produce important advances for treating major hematologic diseases in less developed regions. A major focus relates to the socio-economic and medical burden of these diseases in developing countries with limited resources. As such, these problems provide a challenge and an opportunity for collaborative interaction between hematologists and policy makers worldwide.

Acute Disease↗
PubMed2001

Clinical and hematologic features of beta0-thalassemia (frameshift 41/42 mutation) in Thai patients.

BACKGROUND AND OBJECTIVES: Frameshift 41/42 mutation is the most common mutation of beta0-thalassemia found in Thailand. We studied clinical and hematologic features in 84 patients and relatives with frameshift 41/42 to determine whether it is possible to predict phenotypic severity from genetic factors. DESIGN AND METHODS: The clinical phenotypes and hematologic data of Thai patients with frameshift 41/42 were studied. Alpha-thalassemia, Hb Constant Spring (HbCS) genes and the presence of Xmnl-Ggamma polymorphism were studied in patients who had mild symptoms. RESULTS: Homozygotes for frameshift 41/42 and compound heterozygotes for frameshift 41/42 and beta0-thalassemia produced severe symptoms and have a thalassemia major phenotype. Combination of frameshift 41/42 and beta0-thalassemia or Hb E produced mild to moderate symptoms with thalassemia intermedia phenotype and severe symptoms with thalassemia major phenotype. The co-inheritance of beta-thalassemia or HbCS gene or the presence of Xmnl-Ggamma polymorphism was not associated with mild disease in patients with frameshift 41/42 and HbE. INTERPRETATION AND CONCLUSIONS: The clinical phenotype of homozygotes for frameshift 41/42 and compound heterozygotes for frameshift 41/42 and beta0-thalassemia could be used to predict a severe phenotype with thalassemia major. However, the clinical phenotype of compound heterozygotes of frameshift 41/42 and beta0-thalassemia or Hb E were variable and could not be accurately predicted. Associations between concomitant alpha-thalassemia or HbCS of the presence of Xmnl-Ggamma polymorphism and a mild clinical phenotype are not apparent, indicating the involvement of other ameliorating determinants or genetic modifications.

Alleles↗
PubMed2000

Restoration of hemoglobin A synthesis in erythroid cells from peripheral blood of thalassemic patients.

Mononuclear cells from peripheral blood of thalassemic patients were treated with morpholino oligonucleotides antisense to aberrant splice sites in mutant beta-globin precursor mRNAs (pre-mRNAs). The oligonucleotides restored correct splicing and translation of beta-globin mRNA, increasing the hemoglobin (Hb) A synthesis in erythroid cells from patients with IVS2-654/beta(E), IVS2-745/IVS2-745, and IVS2-745/IVS2-1 genotypes. The maximal Hb A level for repaired IVS2-745 mutation was approximately 30% of normal; Hb A was still detectable 9 days after a single treatment with oligonucleotide. Thus, expression of defective beta-globin genes was repaired and significant level of Hb A was restored in a cell population that would be targeted in clinical applications of this approach.

Cell Nucleus↗
PubMed2000

Lymphocyte subsets and specific T-cell immune response in thalassemia.

Infection is very common in thalassemia and is one of the major causes of death. To date, it is not quite clear why these patients are susceptible to infection. In this study, lymphocyte immunophenotyping for CD3(+) (T-cells), CD3(+)CD4(+) (T-helper/inducer cells), CD3(+)CD8(+) (T-suppressor/cytotoxic cells), CD3(-)CD19(+) (B-cells), and CD3(-)CD16/56(+) (natural killer cells) subsets and expression of the activation antigen CD69 on CD3(+)CD4(+) and CD3(+)CD8(+) T-cells were determined in the whole blood of thalassemia patients, using a three-color flow cytometric technique. Results showed that only splenectomized beta-thalassemia/hemoglobin (Hb) E patients displayed a marked increase in absolute number of all lymphocytes. In addition, splenectomized beta-thalassemia/Hb E showed a significantly lower percentage of CD3(+) cells, with a corresponding increase in CD19(+) cells. These differences, when compared with normal subjects and other thalassemia patients, may be attributed to splenectomy. alpha-thalassemia patients, on the other hand, showed no significant difference from the normal group. While lymphocyte subsets in splenectomized beta-thalassemia/Hb E patients showed an abnormal distribution, T-cell activation in these patients was not different from the activation seen in normal subjects. This implies that thalassemia patients, during the steady state of disease, appear to have normal T-lymphocyte function with only moderate abnormalities of T- and B-lymphocyte subsets.

Adult↗
PubMed2000

Molecular analysis of alpha-thalassemia in Nepal: correlation with malaria endemicity.

Thalassemia is a prevalent hereditary disorder characterized by impaired synthesis of globin chains. It has been suggested that the high frequency of thalassemia might reflect heterozygote advantage due to reduced susceptibility to malaria. In Nepal, malaria has often occurred in places below the altitude of 1,200m. We carried out a microepidemiological study on thalassemia in two neighboring populations in Nepal, the Danuwar and the Tamang. Settlements of the Danuwar are located below the limit of the malarial zone (1,200m in altitude), whereas those of the Tamang are found in malaria-free uplands. Three heterozygotes for hemoglobin E (HbE) were observed in the Danuwars. We detected one type (-alpha3.71) of alpha+-thalassemia that involves a deletion of 3.7kb, leading to a loss of one of two alpha-globin genes, in the Danuwars, at a high gene frequency of 63%, while the gene frequency in the Tamangs was only 5%. Analysis of the alpha-globin gene cluster revealed that four different haplotypes were associated with the type of alpha+-thalassemia in the Danuwars. Nucleotide sequences of the D-loop region in the mitochondrial DNA of the two populations indicated a similar nucleotide diversity in each population. The fixation index, FST, representing the degree of genetic differentiation estimated from mitochondrial DNA diversities (FST, 0.05), was smaller than that obtained from the gene frequencies of alpha-thalassemia (FST, 0.55). If we assume neutral molecular evolution in the D-loop region of mitochondrial DNA, these results suggest that the high frequency of alpha+-thalassemia may be due to biological adaptation to the malarial environment rather than to events such as a bottleneck.

DNA, Mitochondrial↗
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↗
PubMed1999

Impairment of Plasmodium falciparum growth in thalassemic red blood cells: further evidence by using biotin labeling and flow cytometry.

Certain red blood cell (RBC) disorders, including thalassemia, have been associated with an innate protection against malaria infection. However, many in vitro correlative studies have been inconclusive. To better understand the relationship between human RBCs with thalassemia hemoglobinopathies and susceptibility to in vitro infection, we used an in vitro coculture system that involved biotin labeling and flow cytometry to study the ability of normal and variant RBC populations in supporting the growth of Plasmodium falciparum malaria parasites. Results showed that both normal and thalassemic RBCs were susceptible to P falciparum invasion, but the parasite multiplication rates were significantly reduced in the thalassemic RBC populations. The growth inhibition was especially marked in RBCs from alpha-thalassemia patients (both alpha-thalassemia1/alpha-thalassemia2 and alpha-thalassemia1 heterozygote). Our observations support the contention that thalassemia confers protection against malaria and may explain why it is more prevalent in malaria endemic areas.

Animals↗
PubMed1999

Role of FcgammaRI (CD64) in erythrocyte elimination and its up-regulation in thalassaemia.

To examine any role of the high affinity Fcgamma class I receptor (FcgammaRI) (CD64) in erythrocyte elimination by mononuclear phagocytes (MP) in thalassaemia (thal), we investigated the in vitro interaction of beta-thalassaemic erythrocytes with monocytes (Mo) whose FcgammaR expression had been modulated by cytokines. Treatment of Mo with interferon (IFN)-gamma or interleukin (IL)-10 which up-regulate FcgammaRI, caused a dose-dependent increase in binding of beta-thalassaemic erythrocytes, whereas stimulation with IL-4 which down-regulates the receptor, reduced this interaction, in a dose-dependent manner, to that of normal erythrocytes. Binding of thalassaemic erythrocytes by IFN-gamma or IL-10-treated Mo was inhibited by FcgammaRI-specific reagents. In addition, Mo expression of FcgammaRI and HLA class II DR was determined by flow cytometry in Thai patients with HbH disease (alpha1/alpha2 or alpha1/Hb Constant Spring) (n = 15) or beta degrees -thal/HbE (n = 16). In both groups of patients FcgammaRI expression was increased as compared to normal controls (n = 14): mean fluorescence intensity (+/-SD) 124.79 +/- 38. 77 in HbH disease and 121.86 +/- 18.23 in beta degrees -thal/HbE versus 91.94 +/- 17.36 in normal controls (P < 0.01 and P < 0.001, respectively). In contrast, HLA class II DR expression was similar in patients and controls. The results suggest that, in thalassaemia, up-regulated FcgammaRI on mononuclear phagocytes plays a role in their interaction with erythrocytes and that this process can be modified by cytokines.

Dose-Response Relationship, Drug↗