Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 86
Filtrar
1.
Matern Child Health J ; 23(Suppl 1): 29-45, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30506126

RESUMEN

Objectives Since the 1990s, programs for the control of micronutrient deficiencies became a public health priority for many governments, including the countries partnering the project "Sustainable Micronutrient Interventions to Control Deficiencies and Improve Nutritional Status and General Health in Asia" (SMILING): Cambodia, Indonesia, Laos-PDR, Thailand and Vietnam. The aim of this study was to map which micronutrient deficiencies have been addressed and which interventions were in place in the SMILING countries. Methods The mapping covered the period up to 2012. Updated information from relevant surveys after 2012 is included in this paper after the completion of the SMILING project. The mapping of micronutrient status was limited to either national or at least large-scale surveys. Information on nutrition interventions obtained through a systematic mapping of national programs combined with a snowball collection from various sources. Results Among the five SMILING countries, Thailand differed historically by an early implementation of a nationwide community-based nutrition program, contributing to reductions in undernutrition and micronutrient deficiencies. For Cambodia, Indonesia, Laos PDR, and Vietnam, some national programs addressing micronutrients have been implemented following adjusted international recommendations. National surveys on micronutrient status were scattered and inconsistent across the countries in design and frequency. Conclusion for practice In conclusion, some micronutrient deficiencies were addressed in national interventions but the evidence of effects was generally lacking because of limited nationally representative data collected. Improvement of intervention programs to efficiently reduce or eliminate micronutrient deficiencies requires more systematic monitoring and evaluation of effects of interventions in order to identify best practices.


Asunto(s)
Anemia/etiología , Hierro , Desnutrición/prevención & control , Micronutrientes/deficiencia , Estado Nutricional , Deficiencia de Vitamina A , Deficiencia de Vitamina B 12 , Adolescente , Adulto , Anemia/metabolismo , Anemia Ferropénica , Asia Sudoriental , Niño , Femenino , Deficiencia de Ácido Fólico/complicaciones , Humanos , Hierro/metabolismo , Deficiencias de Hierro , Masculino , Persona de Mediana Edad , Evaluación de Programas y Proyectos de Salud , Deficiencia de Vitamina A/complicaciones , Deficiencia de Vitamina B 12/complicaciones , Adulto Joven
2.
Int J Lab Hematol ; 34(6): 559-65, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22762348

RESUMEN

Thalassemia and abnormal hemoglobin are the most common genetic disorders and are considered health problems in many developing countries. In the last few years, there has been much progress in laboratory diagnosis, treatment and control of thalassemia. The variation in the clinical severity in both α- and ß-thalassemia reflects a genotype-phenotype interaction. This is important for future therapeutic intervention and should be well characterized in each population. The quality of life of the patients is much improved with regular blood transfusion and novel iron chelators. The cure for thalassemia is possible by stem cell transplantation and future gene therapy. It is expected that under multinational collaboration the prevention of thalassemia will happen worldwide.


Asunto(s)
Hemoglobinopatías/diagnóstico , Hemoglobinopatías/terapia , Calidad de Vida , Transfusión Sanguínea/métodos , Terapia Genética/métodos , Terapia Genética/tendencias , Genotipo , Hemoglobinopatías/genética , Humanos , Quelantes del Hierro/uso terapéutico , Fenotipo , Trasplante de Células Madre/métodos , Trasplante de Células Madre/tendencias , Talasemia/diagnóstico , Talasemia/genética , Talasemia/terapia
3.
Med Chem ; 7(1): 62-9, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21235521

RESUMEN

Non-transferrin bound iron (NTBI) is found in plasma of ß-thalassemia patients and causes oxidative tissue damage. Cardiac siderosis and complications are the secondary cause of death in ß-thalassemia major patients. Desferrioxamine (DFO), deferiprone (DFP) and deferasirox (DFX) are promising chelators used to get negative iron balance and improve life quality. DFP has been shown to remove myocardial iron effectively. Curcuminoids (CUR) can chelate plasma NTBI, inhibit lipid peroxidation and alleviate cardiac autonomic imbalance. Effects of CUR on cardiac iron deposition and function were investigated in iron-loaded mice. Wild type ((mu)ß(+/+) WT) and heterozygous ß-knockout ((mu)ß(th-3/+) BKO) mice (C57BL/6) were fed with ferrocene-supplemented diet (Fe diet) and coincidently intervened with CUR and DFP for 2 months. Concentrations of plasma NTBI and malondialdehyde (MDA) were measured using HPLC techniques. Heart iron concentration was determined based on atomic absorption spectrophotometry and Perl's staining methods. Short-term electrocardiogram (ECG) was recorded with AD Instruments Power Lab, and heart rate variability (HRV) was evaluated using MATLAB 7.0 program. Fe diet increased levels of NTBI and MDA in plasma, nonheme iron and iron deposit in heart tissue significantly, and depressed the HRV, which the levels were higher in the BKO mice than the WT mice. CUR and DFP treatments lowered plasma NTBI as well as MDA concentrations (p <0.05), heart iron accumulation effectively, and also improved the HRV in the treated mice. The results imply that CUR would be effective in decreasing plasma NTBI and myocardial iron, alleviating lipid peroxidation and improving cardiac function in iron-loaded thalassemic mice.


Asunto(s)
Curcumina/análogos & derivados , Corazón/efectos de los fármacos , Quelantes del Hierro/farmacología , Sobrecarga de Hierro/tratamiento farmacológico , Peroxidación de Lípido/efectos de los fármacos , Transferrina/metabolismo , Talasemia beta/tratamiento farmacológico , Animales , Curcumina/química , Curcumina/farmacología , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Hierro/sangre , Quelantes del Hierro/química , Sobrecarga de Hierro/complicaciones , Hierro de la Dieta/metabolismo , Masculino , Malondialdehído/sangre , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Talasemia beta/metabolismo
4.
Malays J Nutr ; 16(1): 137-48, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22691861

RESUMEN

Spices and herbs are rich in polyphenols and widely used in habitual diets in the tropical regions. To elucidate their effects on human health, intake of the portion of spices and herbs from habitual diets should be determined. Consumption patterns were determined from 24-hour records or recalls of 181 men and 370 women in Khonkaen and Ubon Ratchathani provinces, representing upper and lower northeast Thailand. There was a slight variation in dishes, but twelve spices/herbs were commonly used in the two areas. The amounts of spices/ herbs in the four most common dishes (Somtum, Jaew, Pon and Kang-Nor-Mai) were estimated by weighing ingredients before and after cooking. The average amount of spices/herbs consumed was 4.9, 26.1, 14 and 11 g/meal, contributing 36.6, 43.1, 20.6 and 29.8 mg polyphenols/meal for Somtum, Jaew, Pon and Kang- Nor-Mai, respectively. Chili was common in all recipes, with an average amount of 8.3-27.5 mg polyphenols/meal. In conclusion, habitual northeast Thai diets contain several spices/herbs and a substantial amount of polyphenols was commonly consumed.

5.
Int J Obes (Lond) ; 32(7): 1098-104, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18427564

RESUMEN

BACKGROUND: Overweight is increasing in transition countries, while iron deficiency remains common. In industrialized countries, greater adiposity increases risk of iron deficiency. Higher hepcidin levels in obesity may reduce dietary iron absorption. Therefore, we investigated the association between body mass index (BMI) and iron absorption, iron status and the response to iron fortification in populations from three transition countries (Thailand, Morocco and India). METHODS: In Thai women (n=92), we examined the relationship between BMI and iron absorption from a reference meal containing approximately 4 mg of isotopically labeled fortification iron. We analyzed data from baseline (n=1688) and intervention (n=727) studies in children in Morocco and India to look for associations between BMI Z-scores and baseline hemoglobin, serum ferritin and transferrin receptor, whole blood zinc protoporphyrin and body iron stores, and changes in these measures after provision of iron. RESULTS: In the Thai women, 20% were iron deficient and 22% were overweight. Independent of iron status, a higher BMI Z-score was associated with decreased iron absorption (P=0.030). In the Indian and Moroccan children, 42% were iron deficient and 6.3% were overweight. A higher BMI Z-score predicted poorer iron status at baseline (P<0.001) and less improvement in iron status during the interventions (P<0.001). CONCLUSIONS: Adiposity in young women predicts lower iron absorption, and pediatric adiposity predicts iron deficiency and a reduced response to iron fortification. These data suggest the current surge in overweight in transition countries may impair efforts to control iron deficiency in these target groups. Interactions of the 'double burden' of malnutrition during the nutrition transition may have adverse consequences.


Asunto(s)
Adiposidad , Anemia Ferropénica/metabolismo , Países en Desarrollo , Hierro/metabolismo , Adolescente , Adulto , Biomarcadores/sangre , Índice de Masa Corporal , Niño , Femenino , Ferritinas/sangre , Alimentos Fortificados , Encuestas Epidemiológicas , Hemoglobinas/análisis , Humanos , India , Absorción Intestinal , Trastornos del Metabolismo del Hierro/sangre , Hierro de la Dieta/administración & dosificación , Marcaje Isotópico , Masculino , Persona de Mediana Edad , Marruecos , Análisis Multivariante , Protoporfirinas/análisis , Receptores de Transferrina/sangre , Tailandia
6.
Clin Genet ; 72(6): 497-505, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17894837

RESUMEN

We evaluated the contribution of 67 single nucleotide polymorphisms (SNPs) within the beta-globin gene cluster to disease severity in groups of 207 mild- and 305 severe unrelated patients from Thailand with Hemoglobin E (HbE)/beta(0)-thalassemia and normal alpha-globin genes. Our analysis showed that these SNPs comprise two distinct linkage disequilibrium blocks, one containing the beta-globin gene and the other extending from the locus control region (LCR) to the delta gene, which are separated by a recombination hotspot in the narrow region of the beta-globin gene promoter. Forty-five SNPs within the interval including the LCR region and the delta gene showed strong association with disease severity. The strongest association was observed with the XmnI polymorphism located 158-bp upstream to the G gamma gene (p = 4.6E-12). Carriers of the T allele of XmnI were more likely to have a milder disease course and higher level of fetal hemoglobin (HbF) in both the mild (p = 0.005) and severe (p = 8.7E-06) patient groups. Haplotype analysis revealed that the T allele of XmnI was nearly always in cis with the HbE allele. The high frequency of this haplotype may be favored by positive selection against malarial infection. Further studies are needed to validate this hypothesis and determine whether XmnI or another closely linked variant modulates severity and HbF levels in patients with beta(0)-thalassemia/HbE disease.


Asunto(s)
Globinas/genética , Hemoglobina E/genética , Familia de Multigenes , Polimorfismo de Nucleótido Simple , Talasemia beta/genética , Hemoglobina Fetal/metabolismo , Haplotipos , Humanos , Desequilibrio de Ligamiento , Región de Control de Posición , Fenotipo , Tailandia , Talasemia beta/sangre
7.
Eur J Clin Nutr ; 60(5): 623-32, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16391573

RESUMEN

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.


Asunto(s)
Yodo/deficiencia , Micronutrientes , Zinc/deficiencia , Factores de Edad , Anemia Ferropénica/sangre , Anemia Ferropénica/epidemiología , Antropometría , Niño , Estudios Transversales , Países en Desarrollo , Suplementos Dietéticos , Femenino , Hemoglobinas/análisis , Humanos , Yodo/administración & dosificación , Yodo/orina , Masculino , Micronutrientes/administración & dosificación , Micronutrientes/sangre , Micronutrientes/deficiencia , Factores Sexuales , Clase Social , Tailandia/epidemiología , Deficiencia de Vitamina A/sangre , Deficiencia de Vitamina A/complicaciones , Deficiencia de Vitamina A/epidemiología , Zinc/administración & dosificación , Zinc/sangre
8.
Eur J Haematol ; 74(4): 315-23, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15777344

RESUMEN

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.


Asunto(s)
Apoptosis/fisiología , Células Precursoras Eritroides/citología , Células Precursoras Eritroides/metabolismo , FN-kappa B/metabolismo , Apoptosis/efectos de los fármacos , Transporte Biológico Activo/efectos de los fármacos , Proteína Reguladora de Apoptosis Similar a CASP8 y FADD , Ensayo de Unidades Formadoras de Colonias , Ciclosporina/farmacología , Células Precursoras Eritroides/efectos de los fármacos , Eritropoyetina/farmacología , Humanos , Técnicas In Vitro , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Potenciales de la Membrana/efectos de los fármacos , FN-kappa B/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Proteínas Recombinantes , Proteína bcl-X
9.
Southeast Asian J Trop Med Public Health ; 33 Suppl 2: 145-50, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12755285

RESUMEN

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.


Asunto(s)
Hemoglobinopatías/diagnóstico , Tamizaje Masivo/métodos , Talasemia/diagnóstico , Adulto , Portador Sano , Femenino , Hemoglobinas Anormales/análisis , Humanos , Masculino , Valor Predictivo de las Pruebas , Embarazo , Reproducibilidad de los Resultados
10.
Br J Haematol ; 112(2): 483-7, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11167851

RESUMEN

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.


Asunto(s)
Hemoglobinas Anormales/metabolismo , Oxígeno/metabolismo , Talasemia/sangre , Cromatografía Líquida de Alta Presión , Procesamiento Automatizado de Datos , Índices de Eritrocitos , Hemoglobina Fetal/análisis , Hemoglobina A2/análisis , Hemoglobina H/análisis , Hemoglobinas Anormales/genética , Humanos , Talasemia/genética
11.
Hemoglobin ; 25(4): 397-407, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11791873

RESUMEN

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.


Asunto(s)
Pruebas Genéticas/métodos , Talasemia beta/genética , Asia/epidemiología , Secuencia de Bases , Análisis Mutacional de ADN/métodos , Cartilla de ADN , Humanos , Cooperación Internacional , Mutación , Reacción en Cadena de la Polimerasa/métodos , Talasemia beta/epidemiología
13.
J Pediatr Hematol Oncol ; 22(6): 573-80, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11132233

RESUMEN

PURPOSE: Heterogeneity in the clinical manifestation of beta-thalassemic diseases may occur from the nature of beta-globin gene mutations, alpha-thalassemia gene interaction, or differences in the amount of hemoglobin (Hb) F production. This study was conducted to determine whether these genetic determinant factors can predict phenotypic severity of patients with beta-thalassemia and to assess the relationship between the genotype and phenotype of the disease. MATERIALS AND METHODS: A total of 144 patients with beta-thalassemia were divided into mild (46 patients), intermediate (55 patients), and severe groups (43 patients). DNA analysis based on polymerase chain reaction technique was performed to characterize types of beta-thalassemia mutation, interaction of alpha-thalassemia, and XmnI polymorphism 5' to Ggamma-globin gene. RESULTS: Two alleles of mild beta-thalassemia mutation (beta+/beta+-thalassemia or beta+-thalassemia/Hb E) resulted in a mild clinical symptom whereas two alleles of severe beta-thalassemia mutation (betao/betao) produced a severe clinical phenotype. Compound heterozygosity for mild and severe alleles of beta-thalassemia (betao/ beta+-thalassemia or betao-thalassemia/Hb E) led to variable severity of anemia. Coinheritance of alpha-thalassemia alleviated the severity of beta-thalassemia disease in those patients with at least one allele of the mild beta-thalassemia genotype. DNA polymorphism at position-158 nt 5' to the Ggamma-globin gene was demonstrated by XmnI restriction enzyme. Homozygote of the XmnI site, +/+, was found to have a strong linkage with high Hb F levels and high hemoglobin production in two patients who had mild clinical symptoms. However, some patients who had XmnI site -/- also had mild clinical symptoms because the XmnI- was found to be associated with beta+-thalassemia mutation. CONCLUSION: Types of beta-thalassemia mutation and coinheritance of alpha-thalassemia in the patient who has at least one allele of the mild beta-thalassemia genotype are predictive for the clinical severity of the disease. However, a mild clinical symptom in some patients with betao/beta+-thalassemia or betao-thalassemia/Hb E who do not have a detectable alpha-thalassemia haplotype and no linkage with XmnI++ suggests that there are other confounding factors responsible for the severity differences of the disease.


Asunto(s)
Globinas/genética , Mutación , Talasemia beta/genética , Talasemia beta/fisiopatología , Edad de Inicio , Niño , Preescolar , Genotipo , Humanos , Polimorfismo Genético
14.
Hemoglobin ; 24(2): 105-16, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10870881

RESUMEN

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.


Asunto(s)
Hemoglobina E/genética , Reacción en Cadena de la Polimerasa/métodos , ARN Mensajero/análisis , Talasemia beta/genética , Adulto , Mutación del Sistema de Lectura , Globinas/genética , Hemoglobinas/metabolismo , Humanos , Modelos Lineales , Estabilidad del ARN , ARN Mensajero/sangre , Reticulocitos
16.
Curr Opin Hematol ; 7(2): 106-12, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10698297

RESUMEN

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.


Asunto(s)
Hemoglobina E/genética , Talasemia beta , Asia Sudoriental/epidemiología , Genotipo , Humanos , Fenotipo , Diagnóstico Prenatal , Talasemia beta/diagnóstico , Talasemia beta/epidemiología , Talasemia beta/genética
17.
Prenat Diagn ; 19(5): 428-35, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10360511

RESUMEN

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.


Asunto(s)
Enfermedades Fetales/diagnóstico , Diagnóstico Prenatal , Talasemia beta/diagnóstico , Cartilla de ADN , Femenino , Enfermedades Fetales/embriología , Enfermedades Fetales/genética , Humanos , Immunoblotting , Reacción en Cadena de la Polimerasa , Valor Predictivo de las Pruebas , Embarazo , Talasemia beta/embriología , Talasemia beta/genética
20.
Artículo en Inglés | MEDLINE | ID: mdl-10926267

RESUMEN

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.


Asunto(s)
Pruebas Hematológicas/normas , Hemoglobinopatías/diagnóstico , Hemoglobinas Anormales/análisis , Garantía de la Calidad de Atención de Salud , Talasemia/diagnóstico , Adulto , Índices de Eritrocitos , Eritrocitos/citología , Femenino , Hemoglobina A2/metabolismo , Hemoglobinometría , Hemoglobinopatías/genética , Hemoglobinas/análisis , Heterocigoto , Humanos , Recién Nacido , Embarazo , Estándares de Referencia , Reproducibilidad de los Resultados , Tailandia , Talasemia/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...