External quality assessment (EQA) trials of conventional newborn screening tests for phenylketonuria, galactosemia, congenital adrenal hyperplasia, maple syrup urine disease, homocystinuria, and congenital hypothyroidism, as well as extended newborn screening tests using tandem mass spectrometry, were performed twice in 2016 and 2017. A total of 44 specimens in the form of dried blood spots were distributed in each trial to 16 laboratories. The response rate of these laboratories was 100%. The mean, standard deviation, coefficient of variation, median, and cut-offs were evaluated for each analyte in the newborn screening tests. EQA trials for the analyses of methylmalonic acid, vanillylmandelic acid, catecholamines, metanephrines, organic acids, and amino acids were also performed. A well-designed EQA program and continuous education would improve the performance of metabolite testing.
Adrenal Hyperplasia, Congenital ; Amino Acids ; Catecholamines ; Congenital Hypothyroidism ; Education ; Galactosemias ; Homocystinuria ; Humans ; Infant, Newborn ; Korea* ; Maple Syrup Urine Disease ; Mass Screening ; Methylmalonic Acid ; Phenylketonurias ; Tandem Mass Spectrometry ; Vanilmandelic Acid

BACKGROUND: To evaluate the value of random urinary vanillylmandelic acid (VMA) as a surrogate marker for monitoring tumor response and predicting outcome in patients with neuroblastoma (NB). METHODS: Medical records of 91 patients newly diagnosed with NB at the Samsung Medical Center between June 2014 and August 2017 were reviewed. Clinical associations and other prognostic factors, including age at diagnosis, stage, pathologic subtype, MYCN amplification, and other cytogenetic aberrations, were analyzed. Furthermore, the significance of random urinary VMA level in predicting outcome and tumor response was also evaluated. RESULTS: The median random urinary VMA level at diagnosis was 27.9 (range: 1.7–600) mg/g creatinine. Abdominal primary site, male sex, advanced stage, less differentiated pathology (poorly differentiated, undifferentiated), 11q deletion, and high-risk tumor were associated with a higher VMA level at diagnosis. The VMA level decreased during chemotherapy (28.4%, 16.9%, and 9.6% of the VMA level at diagnosis after 3, 6, and 9 cycles of chemotherapy, respectively). A higher VMA level at diagnosis tends to be associated with a better overall survival in high-risk patients with borderline significance (58.3±18.6% vs. 76.5±13.4%, P=0.050). However, in the multivariate analysis, the VMA level was not a significant predictor of survival. A slower reduction in VMA level during chemotherapy was not associated with a worse overall survival. However, event free survival was significantly better in the rapid responder group. CONCLUSION: A higher VMA level was associated with high-risk features at diagnosis of NB. Random urinary VMA is a valuable marker for monitoring NB response during chemotherapy.
Biomarkers ; Chromosome Aberrations ; Creatinine ; Diagnosis ; Disease-Free Survival ; Drug Therapy ; Humans ; Male ; Medical Records ; Multivariate Analysis ; Neuroblastoma* ; Pathology ; Prognosis ; Vanilmandelic Acid*

A 9-year-old boy presented with increased sweating and abdominal pain. His mother and uncle had been diagnosed with bilateral pheochromocytoma and medullary thyroid carcinoma. Magnetic resonance imaging of the boy's abdomen revealed a 7.5 cm×7.0 cm×6.0 cm mass with a thick peripheral enhancing wall and fluid-fluid level at the right suprarenal region. His ¹²³I-meta-iodobenzylguanidine (MIBG) scan showed a large mass with increased MIBG uptake in the right adrenal gland. The levels of serum norepinephrine, urine epinephrine/norepinephrine, metanephrine, and vanillylmandelic acid were elevated. He, his mother, and two sisters tested positive for the known mutation of multiple endocrine neoplasia type 2A, Cys634Tyr in RET proto-oncogene. Laparoscopic tumor excision and right adrenalectomy were performed. Final diagnosis was pheochromocytoma with malignant behavior, based on adrenal gland scoring scale. However, there was no overt metastasis. After surgery, his symptoms resolved and abnormal laboratory tests were normalized.
3-Iodobenzylguanidine ; Abdomen ; Abdominal Pain ; Adrenal Glands ; Adrenalectomy ; Child ; Diagnosis ; Humans ; Magnetic Resonance Imaging ; Male ; Metanephrine ; Mothers ; Multiple Endocrine Neoplasia Type 2a ; Multiple Endocrine Neoplasia ; Neoplasm Metastasis ; Norepinephrine ; Pheochromocytoma ; Proto-Oncogenes ; Siblings ; Sweat ; Sweating ; Thyroid Neoplasms ; Vanilmandelic Acid

Two external quality assessment (EQA) trials of conventional newborn screening tests for phenylketonuria, galactosemia, congenital adrenal hyperplasia, maple syrup urine disease, homocystinuria, and congenital hypothyroidism, as well as newborn screening tests using tandem mass spectrometry, were performed in 2015. A total of 44 specimens in the form of dried blood spots were distributed to 16 laboratories and the response rate of these laboratories was 100%. The mean, standard deviation, coefficient of variation, median, and cut-offs were evaluated for each analyte in the newborn screening tests. Two EQA trials for the analyses of methylmalonic acid, vanillylmandelic acid, catecholamines, metanephrines, organic acids, and amino acids were also performed. A well-designed EQA program and continuous education would improve the performance of biochemical genetics tests.
Adrenal Hyperplasia, Congenital ; Amino Acids ; Catecholamines ; Congenital Hypothyroidism ; Education ; Galactosemias ; Homocystinuria ; Humans ; Infant, Newborn ; Korea* ; Maple Syrup Urine Disease ; Mass Screening ; Methylmalonic Acid ; Molecular Biology* ; Phenylketonurias ; Tandem Mass Spectrometry ; Vanilmandelic Acid

OBJECTIVETo develop a method for determination of mandelic acid (MA) and phenylglyoxylic acid (PGA) in urine by reagent-free ion chromatography.

METHODSIon chromatography was performed on an AS19 column with a gradient elution solution containing 10-35 mmoL/L KOH at a flow rate of 1.00 ml/min, and MA and PGA were detected at ultraviolet wavelengths of 225 nm and 254 nm, respectively. The samples were diluted 10 times with purified water, then purified on a silver column to remove high concentrations of chloride ion, and injected after being filtered through a 0.2-µm m filter membrane.

RESULTSThe recoveries of standard addition of MA and PGA were 96.5% and 99.3%, respectively, with both relative standard deviations less than 5.0%. Good linear relationships were noted in the range of 1.0-100.0 mg/L for both MA and PGA (r >0.9995). The detection limits of MA and PGA were 0.02 mg/L and 0.05 mg/L, respectively; the minimum detectable concentrations of MA and PGA were 0.2 mg/L and 0.5 mg/L (when the sampling amount was 5.0 ml and diluted to 50.0 ml with water, and the injection volume was 300 µL).

CONCLUSIONSThis method is fast, convenient, and highly sensitive and selective. It can be used for the analysis of MA and PGA in the urine of styrene-exposed workers.

Chromatography, Ion Exchange ; Glyoxylates ; urine ; Humans ; Mandelic Acids ; urine ; Styrene

Two trials of external quality assessment (EQA) of conventional newborn screening tests for phenylketonuria, galactosaemia, congenital adrenal hyperplasia, maple syrup urine disease, homocystinuria, and congenital hypothyroidism, as well as newborn screening tests were performed using tandem mass spectrometry in 2014. A total of 39 specimens in the form of dried blood spots were distributed to 16 laboratories and the response rate of these laboratories was 100%. Screening tests for phenylketonuria and congenital hypothyroidism did not meet the accepted performance criteria in some laboratories. The mean, standard deviation, coefficient of variation, median, and cut-offs were evaluated for each analyte in the newborn screening tests. Two trials of EQA for the analyses of methylmalonic acid, vanillylmandelic acid, catecholamines, metanephrines, organic acids, and amino acids were also performed. A well-designed EQA program and continuous education would improve the performance of biochemical genetic testing.
Adrenal Hyperplasia, Congenital ; Amino Acids ; Catecholamines ; Congenital Hypothyroidism ; Education ; Homocystinuria ; Humans ; Infant, Newborn ; Korea ; Maple Syrup Urine Disease ; Mass Screening ; Methylmalonic Acid ; Molecular Biology* ; Phenylketonurias ; Tandem Mass Spectrometry ; Vanilmandelic Acid

Two trials of external quality assessment (EQA) of conventional newborn screening tests for phenylketonuria, galactosaemia, congenital adrenal hyperplasia, maple syrup urine disease, homocystinuria, and congenital hypothyroidism, as well as of newborn screening tests using tandem mass spectrometry were performed in 2013. A total of 32 specimens in the form of dried blood spots were distributed to 16 laboratories and the response rate of these laboratories was 100%. Total T4, free T4, 17-hydroxyprogesterone, leucine, isoleucine, galactose, methionine, alanine, C8/C2, C8/C10, and C5-OH did not meet the accepted performance criteria. The mean, standard deviation, coefficient of variation, median, and cut-offs were evaluated for each analyte in the newborn screening tests. Two trials of EQA for the analyses of methylmalonic acid, vanillylmandelic acid, very long fatty acids, organic acids, and amino acids were also performed. A well-designed EQA program and continuous education would improve the performance of biochemical genetic tests.
17-alpha-Hydroxyprogesterone ; Adrenal Hyperplasia, Congenital ; Alanine ; Amino Acids ; Congenital Hypothyroidism ; Education ; Fatty Acids ; Galactose ; Homocystinuria ; Humans ; Infant, Newborn ; Isoleucine ; Korea ; Leucine ; Maple Syrup Urine Disease ; Mass Screening ; Methionine ; Methylmalonic Acid ; Molecular Biology* ; Phenylketonurias ; Tandem Mass Spectrometry ; Vanilmandelic Acid

OBJECTIVETo establish a method for simultaneously determining vanilmandelic acid (VMA), 5-hydroxyindoleacetic (5-HIAA), 3, 4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) in urine by high-performance liquid chromatography (HPLC).

METHODSAfter being filtered with a 0.45 µm membrane syringe filter, the urinary samples were injected directly into the HPLC system using a C18 chromatographic column and a fluorescence detector. The excitation and emission wavelengths were chose as 280 nm and 315 nm, respectively, and the urinary samples were carried with a mobile phase of methanol-0.1 mol/L phosphate buffered solution (V/V = 20:80) at a flow rate of 1.0 ml/min and an injection volume of 20 µl.

RESULTSUsing the method reported here, the correlation coefficients of VMA, 5-HIAA, DOPAC, and HVA were 0.9999, 0.9998, 0.9997, 0.9999, respectively, over linear ranges of 0-2.5, 0-2.0, 0-2.0, and 0-2.5 µg/ml, the minimum detectable concentrations were 0.006, 0.008, 0.012, and 0.0082 µg/ml, the average precisions were 4.2%, 3.7%, 4.9%, and 3.6%, and the recovery rates were 91%∼102%, 93%∼101%, 94%∼101%, and 89%∼ 102%.

CONCLUSIONThis determination method is simple, efficient, accurate, and sensitive for the simultaneous detection of VMA, 5-HIAA, DOPAC, and HVA in urine.

Biogenic Amines ; urine ; Chromatography, High Pressure Liquid ; Homovanillic Acid ; urine ; Humans ; Hydroxyindoleacetic Acid ; urine ; Vanilmandelic Acid ; urine

PURPOSE: Anticholinergics are a key element in treating neurogenic detrusor overactivity, but only limited data are available in the pediatric population, thus limiting the application to children even for oxybutynin chloride (OC), a prototype drug. This retrospective study was designed to provide data regarding the efficacy, tolerability, and safety of OC in the pediatric population (0-15 years old) with spinal dysraphism (SD). MATERIALS AND METHODS: Records relevant to OC use for neurogenic bladder were gathered and scrutinized from four specialized clinics for pediatric urology. The primary efficacy outcomes were maximal cystometric capacity (MCC) and end filling pressure (EFP). Data on tolerability, compliance, and adverse events (AEs) were also analyzed. RESULTS: Of the 121 patient records analyzed, 41 patients (34%) received OC at less than 5 years of age. The range of prescribed doses varied from 3 to 24 mg/d. The median treatment duration was 19 months (range, 0.3-111 months). Significant improvement of both primary efficacy outcomes was noted following OC treatment. MCC increased about 8% even after adjustment for age-related increases in MCC. Likewise, mean EFP was reduced from 33 to 21 cm H2O. More than 80% of patients showed compliance above 70%, and approximately 50% of patients used OC for more than 1 year. No serious AEs were reported; constipation and facial flushing consisted of the major AEs. CONCLUSIONS: OC is safe and efficacious in treating pediatric neurogenic bladder associated with SD. The drug is also tolerable and the safety profile suggests that adjustment of dosage for age may not be strictly observed.
Adolescent ; Child ; Child, Preschool ; Drug Evaluation/methods ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Mandelic Acids/adverse effects/*therapeutic use ; Muscarinic Antagonists/adverse effects/*therapeutic use ; Retrospective Studies ; Spinal Dysraphism/*complications ; Treatment Outcome ; Urinary Bladder, Neurogenic/*drug therapy/etiology/physiopathology ; Urological Agents/adverse effects/*therapeutic use

OBJECTIVETo investigate the role of genetic polymorphisms of epoxide hydrolase 1 (EPHX1) in the metabolism of styrene in vivo.

METHODSFifty-six styrene-exposed workers, who worked in the painting workshop of an enterprise for manufacturing glass fiber-reinforced plastic yachts in Shandong Province, China for over one year and were protected in approximately the same way, were selected as study subjects. The 8-hour time-weighted average concentration (8 h-TWA) of styrene and the concentrations of mandelic acid (MA) and phenyl glyoxylic acid (PGA) as urinary metabolites were measured. The genetic polymorphisms of EPHX1 were detected by polymerase chain reaction-restriction fragment length polymorphism analysis.

RESULTSThe urinary concentrations of MA and PGA were 177.25±82.36 mg/g Cr and 145.91±69.73 mg/g Cr, respectively, and the 8 h-TWA of styrene was 133.28±95.81 mg/m3. Urinary concentrations of MA and PGA were positively correlated with 8 h-TWA of styrene (R=0.861, P < 0.05; R=0.868, P < 0.05). The subjects were divided into high-exposure group (8 h-TWA >50 mg/m(3)) and low-exposure group (8 h-TWA ≤ 50 mg/m(3), and in the two groups, the urinary concentrations of MA and PGA were significantly higher in the individuals carrying high-activity genotypes of EPHX1 than in those carrying low-activity genotypes of EPHX1 (P < 0.05).

CONCLUSIONGenetic polymorphisms of EPHX1 play an important role in the metabolic process of styrene in vivo.

Adult ; Air Pollutants, Occupational ; pharmacokinetics ; China ; Epoxide Hydrolases ; genetics ; Glyoxylates ; urine ; Humans ; Male ; Mandelic Acids ; urine ; Occupational Exposure ; Polymorphism, Genetic ; Styrene ; pharmacokinetics