Junghan Song

Monitoring of anti-tuberculosis drug concentrations and dose adjustment can be helpful in cases that show poor response to treatment. Here, we describe a method that can rapidly and simultaneously measure the blood concentrations of four anti-tuberculosis drugs (isoniazid, rifampicin, pyrazinamide, and ethambutol) and two major metabolic ratios (acetylisoniazid/isoniazid and 25-desacetylrifampicin/rifampicin) using high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS). A C

BACKGROUND: The results of studies on the association of ecNOS polymorphisms and vascular diseases are inconsistent. To explore the nature of this interaction in the absence of confounding factors, such as smoking, we measured ecNOS mRNA, protein, and enzyme activity in cultured human umbilical vein endothelial cells (HUVECs) with and without ecNOS polymorphisms. METHODS: We identified a T(-786)-->C polymorphism in the promoter region, the intron 4 variable number of tandem repeats (VNTR), the E

To assess the clinical efficacy of short-course doxycycline in the treatment of scrub typhus, we compared conventional 7-day tetracycline therapy with 3-day doxycycline therapy in 116 patients. Patients were randomized to receive either tetracycline (500 mg four times daily; n = 50) or doxycycline (100 mg twice daily; n = 66) and were followed for 4 weeks after the completion of treatment. The cure rate was 100% in the tetracycline group and 93.9% in the doxycycline group (P > .05). The two grou

An increased risk for arterial thrombosis is associated with high plasma levels of coagulation and fibrinolytic factors such as PAI-1 and FVII. In this study, the 4G/5G polymorphism in the promoter of PAI-1 gene and Arg353-->Gln polymorphism in the FVII gene were analysed in 139 normal adults and 158 patients with coronary artery disease (CAD), and their association with plasma lipid traits was investigated. There were no significant differences in the allele frequencies of PAI-1 and FVII polymo

Our findings reaffirm that the prevalence of sitosterolemia is probably much higher than previously reported, which also indicates the significant risk of misdiagnosis of sitosterolemia with familial hypercholesterolemia. Special lipid testing including sitosterol, especially in children with uncontrolled hypercholesterolemia, is recommended in children in order to identify potential sitosterolemia patients that would otherwise be neglected.

BACKGROUND: Galactosemia is one of the most important inherited disorders detected by newborn screening tests. Abnormal results in screening tests should be confirmed by enzyme activity assays, but existing methods are time and labor intensive. We developed a novel multiplex enzyme assay for galactosemia using ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). METHODS: [(13)C6]-galactose, [(13)C2]-galactose-1-phosphate, and UDP-glucose were used as substrates for 3 gal

BACKGROUND: Quantification of glycated hemoglobin (HbA1c) is a challenge in patients with hemoglobin (Hb) variants. We evaluated the impact of various Hb variants on five routine HbA1c assays by comparing with the IFCC reference measurement procedure (RMP). METHODS: Whole blood samples showing warning flags or no results on routine HPLC HbA1c assays were confirmed for Hb variants and were submitted to HbA1c quantification using Sebia Capillarys 2 Flex Piercing, Roche Tina-quant HbA1c Gen. 2, Bio

RATIONALE: Metachromatic leukodystrophy (MLD) is a genetic autosomal recessive disease caused by a deficiency in arylsulfatase A. Accumulated sulfatides can be detected in the urine and detection of sulfatiduria is a useful test for diagnosis and monitoring. To our knowledge, no studies have explored the accumulation of sulfatides in dried blood spots (DBSs). We developed an ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) method for measuring sulfatides in DBSs from

OBJECTIVES: Rifampicin is known to be deacetylated in vivo, resulting in its metabolite 25-desacetyl rifampicin, but the enzyme metabolizing rifampicin and the association of this process with any genetic variation have not yet been elucidated. In this study, genetic variations of a surrogate enzyme, carboxylesterase 2 (CES2), and their association with the metabolism of this drug, were investigated. METHODS: Plasma concentrations of rifampicin and 25-desacetyl rifampicin were measured in 35 pat

Theophylline is metabolized to 1,3-dimethyluric acid (1,3-DMU), 3-methylxanthine (3MX), and 1-methylxanthine (1MX) mainly by CYP1A2, and 1MX is rapidly converted to 1-methyluric acid (1MU) by xanthine oxidase (1)(2)(3). Individuals differ in terms of their rates of theophylline metabolism and the resulting serum concentrations (1); moreover, some theophylline metabolites, such as 3MX, are known to have bronchodilator activity. Thus, we need to determine the plasma concentrations of theophylline