Validation of high concentrated thrombin time assay for unfractionated heparin monitoring.

Background: The high concentrated thrombin time (hcTT), a thrombin time modified by increasing the thrombin concentration, is a possible alternative assay to activated partial thromboplastin time (aPTT) in unfractionated heparin (UFH) monitoring. This study aimed to determine the optimal thrombin concentration used in the hcTT assay for UFH monitoring.

Methods: A total of 30 blood samples obtained from healthy volunteers were included in this study.

The hypoferremic response to acute inflammation is maintained in thalassemia mice even under parenteral iron loading.

Background: Hepcidin controls iron homeostasis by inducing the degradation of the iron efflux protein, ferroportin (FPN1), and subsequently reducing serum iron levels. Hepcidin expression is influenced by multiple factors, including iron stores, ineffective erythropoiesis, and inflammation. However, the interactions between these factors under thalassemic condition remain unclear.

Iron homeostasis in a mouse model of thalassemia intermedia is altered between adolescence and adulthood.

Background: Iron overload is one of common complications of β-thalassemia. Systemic iron homeostasis is regulated by iron-regulatory hormone, hepcidin, which inhibits intestinal iron absorption and iron recycling by reticuloendothelial system. In addition, body iron status and requirement can be altered with age.

Prevalence of Thalassemia and Glucose-6-Phosphate Dehydrogenase Deficiency in Newborns and Adults at the Ramathibodi Hospital, Bangkok, Thailand.

Thalassemias and glucose-6-phosphate dehydrogenase (G6PD) deficiency are the most common inherited blood disorders. They are distributed among populations living in malaria endemic regions resulting in survival advantage from severe malaria disease. The aims of this study were to analyze the prevalence of thalassemias and G6PD deficiency at the Ramathibodi Hospital, Bangkok, Thailand.

Molecular Epidemiology of Hemoglobinopathies in Cambodia.

Determining the magnitude of the thalassemia problem in a country is important for implementing a national prevention and control program. In order to acquire accurate thalassemia prevalence data, the gene frequency of α- and β-thalassemia (α- and β-thal) in different regions of a country should be determined. The molecular basis of thalassemia in Cambodia was performed by polymerase chain reaction (PCR)-based techniques in a community-based cross-sectional survey of 1631 unrelated individuals from three regions, Battambang, Preah Vihear and Phnom Penh.

Identification of Hb Constant Spring (HBA2: c.427T > C) by an Automated High Performance Liquid Chromatography Method.

Laboratory investigation of hemoglobinopathies includes complete blood count (CBC), hemoglobin (Hb) typing by high performance liquid chromatography (HPLC) and DNA analysis. DNA analysis is the most reliable method but requires a manually laborious procedure and is time consuming. A more practical method of detecting abnormal Hbs is the HPLC technique, because it is more rapid and easier to interpret.

Vascular leakage in dengue hemorrhagic Fever is associated with dengue infected monocytes, monocyte activation/exhaustion, and cytokines production.

The vascular leakage was shown by the increment of hematocrit (Hct), dengue viral infected monocyte, monocyte status, and cytokines production in patients infected with dengue virus. Dengue viral antigens were demonstrated in monocytes (CD14+) from peripheral blood mononuclear cells. The increased levels of Hct, interleukin- (IL-) 10, and tumor necrosis factor-alpha (TNF-α) were detected in dengue fever (DF), dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) patients as compared with other febrile illnesses (OFIs).

Elevated erythropoietin and cytokines levels are related to impaired reticulocyte maturation in thalassemic patients.

Serum EPO concentration is related primarily to the rate of erythrocyte production and, under the stimulation of hypoxia, increases exponentially as hemoglobin (Hb) decreased. The level of EPO was determined in 141 subjects including 43 normal, 44 thalassemic patients and 54 thalassemic trait subjects. The EPO level was significantly higher in the thalassemic patients (54.

Comparison of a simple-probe real-time PCR and multiplex PCR techniques for HPA-1 to HPA-6 and HPA-15 genotyping.

Background: We aimed to compare HPA-1 to HPA-6 and HPA-15 genotyping results obtained by a simple-probe real-time polymerase chain reaction (PCR) technique with the multiplex PCR technique.

Methods: Five hundred DNA samples from the Thai National Stem Cell Donor Registry (TSCDR) of the National Blood Centre, Thai Red Cross Society were included. Human platelet antigen (HPA) genotyping was performed by simple-probe real-time PCR and multiplex PCR techniques.

Cardiomyocyte ultrastructural damage in β-thalassaemic mice.

β-thalassaemia is a hereditary anaemia resulting from the absence or reduction in β-globin chain production. Heart complications related to iron overload are the most serious cause of death in these patients. In this report cardiac pathology of β-thalassaemic mice was evaluated by light and electron microscopy.

Tumour necrosis factor gene polymorphism in dengue infection: association with risk of bleeding.

Background: A single nucleotide polymorphism located at the promoter -308A of tumour necrosis factor-alpha (TNF-α) gene may affect transcription and increase cytokine production, leading to the severe manifestation of dengue virus infection.

Aim: To study the association of the TNF-α -308A allele and the severity of patients with dengue infection.

Methods: 112 patients suspected of having dengue infection and 106 normal controls were enrolled in the study.

Alteration of cytokines and chemokines during febrile episodes associated with endothelial cell damage and plasma leakage in dengue hemorrhagic fever.

Background: The leakage of plasma during febrile episodes in dengue-infected patients is a severe condition leading to dengue shock syndrome. Alteration of cytokines/chemokines is suspected to be a major cause of endothelial cell damage in these patients. The study was designed to demonstrate the alteration of cytokines and chemokines in dengue-infected patients during febrile episodes.

Nondeletional Hb Queens Park [α32(B13)Met→Lys]/Hb H (β4) disease.

A rare nondeletional α-thalassemia-2 (α-thal-2) allele was identified in a Thai boy with Hb H (β4) disease. The proband has α-thal-1 (- -(SEA) type) together with a non productive Hb Queens Park (HBA1:c.98T>A) [α32(B13)Met→Lys] α1-globin variant.

A rare Hb H disease due to the - -(SEA) and 16.6 kb α-thalassemia-2 deletions.

A large deletional α-thalassemia-2 (α-thal-2) allele was identified in a Thai woman with Hb H disease. The proband has α-thal-1 (SEA type) in conjunction with a 16.6 kb deletion affecting the α2-globin allele.

Clinical practice guidelines for children with cancer presenting with fever to the emergency room.

Background: Patients with febrile neutropenia (FN) may develop severe infection, septic shock, and death. To improve the outcome of pediatric oncology patients with suspected FN, clinical practice guidelines were developed for these patients at the emergency room (ER). The objective of the present study was to evaluate compliance of the clinical practice guidelines for children with cancer presenting with fever to the ER and adverse outcomes after using the guidelines.

Quantitative analysis of Hb Bart's in cord blood by capillary electrophoresis system.

It has long been recognized that the presence of hemoglobin (Hb) Bart's in newborn's blood is associated with α-thalassemia. However, the automated high-performance liquid chromatography or low-performance liquid chromatography system is unable to quantify the amount of Hbs Bart's and H, which are eluted at the retention time close to 0 min. This study used automatic capillary electrophoresis (CE) system to diagnose various types of α-thalassemia in 587 cord blood samples, including 429 normal α-globin genotype, 120 cases of thalassemia with one α-globin gene defect, 34 cases with two α-globin genes defect, and four cases with three α-globin genes defect.

Molecular screening of the Hbs Constant Spring (codon 142, TAA>CAA, α2) and Paksé (codon 142, TAA>TAT, α2) mutations in Thailand.

Hb Constant Spring [Hb CS, α142(H19)Term] and Hb Paksé [α142(H19)Term] occur from the mutation in the termination codon of the α2-globin gene, TAA>CAA (→Gln) and TAA>TAT (→Tyr), respectively. They are the most common nondeletional α-thalassemia (α-thal) variants causing Hb H disease in Southeast Asia. In this study, 587 cord blood samples were screened for the Hb CS and Hb Paksé mutations by a dot-blot hybridization technique using oligonucleotide probes specific for each mutation.

Activation of mononuclear phagocytes and its relationship to asplenia and phosphatidylserine exposing red blood cells in hemoglobin E/β-thalassemia patients.

Aged or abnormal red blood cells with exposed phosphatidylserine (PSRBCs) are cleared from the circulation by splenic macrophages. In asplenic patients, other mononuclear phagocytic cells in tissues and in circulation may function in this capacity. To better understand these changes and the relationship among splenic status, PS-RBCs, blood monocytes, and serum tumor necrosis factor (TNF-α), a product of mononuclear phagocyte activation, patients with hemoglobin E/β-thalassemia (E/β-Thal) were studied.

Laboratory predictors of dengue shock syndrome during the febrile stage.

The clinical manifestations of dengue hemorrhagic fever (DHF) consist of three successive stages: febrile, toxic and convalescent. The toxic stage is the critical period, which may manifestas circulatory disturbance or even profound shock in some patients. We attempted to determine predictors for the risk of dengue shock syndrome (DSS) during the febrile stage.

Hb Tak and Hb Q-Thailand in Thai patients are S-window hemoglobin variants revealed by high performance liquid chromatography.

The S-window hemoglobin (Hb) variants revealed by high performance liquid chromatography (HPLC) were studied in 12 Thai individuals. The variants were identified, using DNA sequencing and multiplex amplification refractory mutation system-polymerase chain reaction (ARMS-PCR), to be six cases of Hb Tak [beta147 (+AC)], and six cases of Hb Q-Thailand [alpha74(EF3)Asp-->His], respectively. By using the Capillarys 2-capillary zone electrophoresis (CE), Hb Tak and Hb Q-Thailand co-migrated with Hb F in zone 7.

Early diagnosis of dengue virus infection by detection of dengue viral antigen in peripheral blood mononuclear cell.

Background: An essential requirement related to treatment of dengue-infected patients is a rapid and accurate detection of dengue virus during febrile stage of the disease.

Objective: The study examined using direct immunofluorescence staining the presence of dengue viral antigen in peripheral blood mononuclear cells (PBMCs).

Methods: Four hundred forty-five blood samples from 164 patients with dengue fever, dengue hemorrhagic fever, and other febrile illnesses were collected daily from the day of admission until discharge and also at convalescent stage.

Altered vascular homeostasis in type 2 diabetic nephropathy.

Type 2 diabetic nephropathy is a primary cause of ESRD worldwide. Therapeutic strategy in patients with microalbuminuric or macroalbuminuric type 2 diabetic nephropathy usually fails to restore renal function but merely slows the renal disease progression. In contrast, a recent study implies that the restoration of renal function as well as renal perfusion can be accomplished in early stage of type 2 diabetic nephropathy (normoalbuminuria) by correcting the hemodynamic maladjustment in renal microcirculation with vasodilators.

A defective angiogenesis in chronic kidney disease.

Background: A progressive reduction in peritubular capillary flow is observed in chronic kidney disease (CKD) patients as the disease severity progresses. This suggests an altered vascular homeostasis in CKD patients, but such a defective mechanism needs to be verified.

Methods: To study the vascular injury as reflected by circulating endothelial cell (CEC), the balance between angiogenic factor, vascular endothelial growth factor (VEGF), and antiangiogenic factor, endostatin.

Altered vascular homeostasis in chronic kidney disease.

Current treatments of chronic kidney disease (CKD) patients frequently result in progressive decline in renal perfusion, leading to the end-stage renal disease. Such renal failures may be a reflection of the progressive nature of renal microvascular disease. The aim of the present study is to elucidate the mechanism of microvascular homeostasis in CKD patients with moderately impaired renal function.

Improvement of renal function in type 2 diabetic nephropathy.

Background: Therapeutic failure in preventing renal disease progression in type 2 diabetic nephropathy (DN) is due to a failure in the early detection of DN by microalbuminuria and the inappropriate correction of renal hemodynamic maladjustment secondary to glomerular endothelial dysfunction.

Methods: Thirty patients associated with normoalbuminuric type 2 DN were subject to the following studies: tubular function by means of fractional excretion of magnesium (FE Mg), vascular function by means of determining the circulating endothelial cell, VEGF, VEGF/TGF B ratio, and intrarenal hemodynamic studies.

Results: FE Mg, circulating endothelial cells, and TGF B were abnormally elevated, and VEGF/TGF B ratio was decreased in these normoalbuminuric patients.