Possible role of PGD2 in malaria infections.

Objective: To preliminarily investigate the possible role of prostaglandin D2 (PGD2) in malaria infections.

Methods: Blood and urinary samples (n = 120 each) were collected from Thai patients with Plasmodium falciparum (P. falciparum) with moderate (n = 26) and high (n = 4) parasitemia, patients with Plasmodium vivax (P.

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.

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.

Four years' monitoring of in vitro sensitivity and candidate molecular markers of resistance of Plasmodium falciparum to artesunate-mefloquine combination in the Thai-Myanmar border.

Background: The decline in efficacy of artesunate (AS) and mefloquine (MQ) is now the major concern in areas along the Thai-Cambodian and Thai-Myanmar borders.

Methods: The correlation between polymorphisms of pfatp6, pfcrt, pfmdr1 and pfmrp1 genes and in vitro sensitivity of Plasmodium falciparum isolates to the artemisinin-based combination therapy (ACT) components AS and MQ, including the previously used first-line anti-malarial drugs chloroquine (CQ) and quinine (QN) were investigated in a total of 119 P. falciparum isolates collected from patients with uncomplicated P.

Molecular analysis of pfatp6 and pfmdr1 polymorphisms and their association with in vitro sensitivity in Plasmodium falciparum isolates from the Thai-Myanmar border.

The association between pfatp6, pfmdr1 polymorphisms (gene mutation and amplification) and in vitro susceptibility to mefloquine (MQ), artesunate (AS), quinine (QN), and chloroquine (CQ) was investigated in a total of sixty-three Plasmodium falciparum isolates collected from the Thai-Myanmar border. The mutations of pfatp6 at codons R37K, G639D, S769N, and I898I and of pfmdr1 at codons N86Y, Y184F, N1042D, and D1246Y were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Pfatp6 and pfmdr1 gene copy numbers were analyzed by quantitative real time-polymerase chain reaction (qRT-PCR).

Confutation of the existence of sequence-conserved cytochrome P450 enzymes in Plasmodium falciparum.

The aim of the present study was to find evidence for a homologous protein of the mammalian cytochrome P450 family member CYP2B1/B2 in Plasmodium falciparum at the nucleic acid level. Prior research had demonstrated enzyme activity in the parasite comparable to mammalian CYP1A, 2A, 2B and 2E enzymes and presence of CYP enzymes by spectrophotometric and electrophoretic analyses. In recent years, the transcriptome/proteome data of P.

Monitoring of in vitro susceptibilities and molecular markers of resistance of Plasmodium falciparum isolates from Thai-Myanmar border to chloroquine, quinine, mefloquine and artesunate.

Malaria is one of the major causes of morbidity and mortality worldwide. The major factor which has aggravated the situation is the emergence of multidrug resistant Plasmodium falciparum malaria. To successfully deal with the problem, thorough understanding of the molecular bases for reduced parasite sensitivity to existing antimalarial drugs is of considerable importance.

In vitro antimalarial interactions between mefloquine and cytochrome P450 inhibitors.

The treatment and control of malaria is becoming increasingly difficult due to resistance of Plasmodium falciparum strains resistance to commonly used antimalarials. Combination therapy is currently the strategy for combating multi-drug resistant falciparum malaria, through exploiting phamacodynamic synergistic effect and delaying the emergence of drug resistance. The objective of the present study was to investigate antimalarial activity of inhibitors of cytochrome P450 (CYP) enzyme including their interactions with the antimalarial mefloquine against chloroquine-resistant (K1) and chloroquine-sensitive (3D7) P.

Prostaglandin D2 induces heme oxygenase-1 mRNA expression through the DP2 receptor.

Prostaglandin (PG) D(2) exerts multiple actions through interaction with distinct receptors, DP1 and DP2. We have shown that PGD(2) induces the expression of heme oxygenase-1 (HO-1) in the retinal pigment epithelium (RPE) that is essential for survival of photoreceptors. HO-1 is a key enzyme in physiological heme degradation.

Prevention of cadmium accumulation in retinal pigment epithelium with manganese and zinc.

Age-related macular degeneration (AMD) is a leading cause of irreversible blindness in the elderly. Risk factors include old age, female gender, obesity, smoking, low dietary intakes of antioxidants and increased exposure to the toxic metal cadmium (Cd(2+)). Supplementation with high-dose zinc (80 mg) provides some protection, but the mechanism(s) underlying such protection has not been fully elucidated.

Haemoglobin Hope in a northern Thai family: first identification of homozygous haemoglobin Hope associated with haemoglobin H disease.

Haemoglobin (Hb) Hope [beta136(H14)Gly-->Asp(GGT-->GAT)] is one of the unstable haemoglobin variants of the beta-globin chain, which is demonstrated in people of various ethnic backgrounds. Here we report a Thai female patient with clinical thalassaemia intermedia since childhood. This patient had experienced neither blood transfusion nor hospitalisation.

Hemoglobin H disease induced by the common SEA deletion and the rare hemoglobin Quong Sze in a Thai female: longitudinal clinical course, molecular characterization, and development of a PCR/RFLP-based detection method.

We report on a Thai female patient who presented with hypochromic microcytic anemia, hepatosplenomegaly, and failure to thrive since 3 years of age. Hematological and hemoglobin (Hb) analysis were consistent with a clinical diagnosis of Hb H disease. However, no abnormal Hb fraction had ever been detected.

Reticulocyte analysis in systemic lupus erythematosus and chronic renal failure using flow cytometry.

The number and maturation of circulating reticulocytes were measured in patients with systemic lupus erythematosus (SLE) and chronic renal failure (CRF) using an automated hematological analyzer (Technicon H*3 RTX) for their erythropoietic activities. Both SLE and CRF patients had increased reticulocyte numbers with a low degree of maturation. The SLE patients had no changes in mean reticulocyte corpuscular volume (MCVr) as compared to normal subjects (110.

Increased circulating activated endothelial cells, vascular endothelial growth factor, and tumor necrosis factor in thalassemia.

An increased number of circulating endothelial cells (CECs) was demonstrated in alpha- and beta-thalassemic patients, beta-thalassemia/hemoglobin E (BE), both splenectomized (BE[S]) and non-splenectomized (BE[NS]), had higher numbers of CECs than alpha-thalassemia, both HbH (alpha-thal l/alpha-thal 2; H) and HbH with hemoglobin Constant Spring (alpha-thal 1/CS; H/CS). CECs were also increased in heterozygous HbE (EA) and homozygous HbE (EE). The highest level of tumor necrosis factor-alpha (TNF-alpha) was found in HbH/CS patients, whereas the highest levels of vascular endothelial growth factor (VEGF) was observed in BE[S] patients.

Different reticulocyte volume in diabetes mellitus patients with and without hypercholesterolemia and/or hypertriglyceridemia.

Red cells and reticulocytes from patients with diabetes mellitus (DM) were analysed using laser and computer technology of H*3 hematology analyzer. Four groups of diabetes mellitus patients: diabetes with normolipemia (DM) (n = 12) and DM patients with excess triglyceride (DM-T) (n = 7) or cholesterol (DM-C) (n = 21) or both (DM-TC) (n = 21) were studied. Mean corpuscular volume of mature red cells (Mean +/- SD = 93.

Reticulocyte analysis in iron deficiency anemia and hemolytic anemia.

Reticulocyte analysis was studied in 28 anemic patients, 15 with iron deficiency anemia (IDA), and 13 with hemolytic anemia including 9 glucose 6 phosphate dehydrogenase deficiency (G6PD def.), and 4 with G6PD def. combined with HbE trait or alpha thalassemia trait (alpha thal trait).

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.

Red cell parameters in alpha-thalassemia with and without beta-thalassemia trait or hemoglobin E trait.

Eighty-five patients who attended at Ramathibodi Hospital during November 1994 to June 1996 were investigated for thalassemia genotype, hemoglobin (Hb) typing and blood cell parameters. All patients were screened primarily for complete blood count using the Technicon H*3 automated hematology analyzer and Hb typing using the automated HPLC. Their genotypes were evaluated by in vitro gene amplification using primers for detection of common alpha-thalassemic genes found in the Thai population.