The excretion of ammonia is dependent upon several factors: the amount and duration of acid intake, presumably affecting variations in intracellular enzyme activity (1-3), the availability of precursors from which ammonia can be formed (4-6), and the pH of the urine (7-9). With respect to the effect of urine pH, the excretion of ammonia resembles that of a number of organic bases, such as quini...

Xylene is a commonly used toxic volatile organic solvent. Diagnosis of acute xylene poisoning is limited by the lack of a readily available analytic assay. Methylhippuric acid, a metabolite of xylene excreted in the urine, is used for biomonitoring occupational exposures to xylene. We report two cases of acute occupational poisoning from xylene inhalation suggested by determination of high urin...

Although metabolic acidosis from a variety of causes is very frequent in infancy, congenital acidosis appears to be extremely rare. Two unrelated cases of a new syndrome are now described with a congenital metabolic acidosis resulting from a block in the conversion of methylmalonic acid to succinic acid. The first had persistent mild acidosis with acute episodes of severe metabolic acidosis dur...

Ogata, M., Yoshiko, T., and Tomokuni, K. (1971). Brit. J. industr. Med., 28, 386-391. Excretion of organic chlorine compounds in the urine of persons exposed to vapours of trichloroethylene and tetrachloroethylene. Male volunteers were exposed to 170 p.p.m. of trichloroethylene vapour either for 3 hours or for 7 hours with one break of 1 hour; or to 87 p.p.m. of tetrachloroethylene vapour for 3...

This work describes a new extraction method with hollow-fiber liquid-phase microextraction based on facilitated pH gradient transport for analyzing hippuric acid and mandelic acid in aqueous samples. The factors affecting the metabolites extraction were optimized as follows: the volume of sample solution was 10 mL with pH 2 containing 0.5 mol·L-1 sodium chloride, liquid membrane containing 1-oc...

A linear correlation exists between the trichloroethylene concentration in the work environments and the level of total trichloro compounds in the urine of the workers, as expressed by the equation: Gamma = 7.25=chi + 5.5, where Gamma is trichloroethylene in air (ppm) is Chi is total trichloro compounds in urine (mg/l). Trichloroethanol level is also linearly related to trichloroethylene concen...

Diabetic kidney disease is the leading cause of ESRD, but few biomarkers of diabetic kidney disease are available. This study used gas chromatography-mass spectrometry to quantify 94 urine metabolites in screening and validation cohorts of patients with diabetes mellitus (DM) and CKD(DM+CKD), in patients with DM without CKD (DM-CKD), and in healthy controls. Compared with levels in healthy cont...

BACKGROUND Reversed-phase HPLC (RP-HPLC) has become an alternative to ion-exchange chromatography for amino acid analysis in biological fluids. However, validation studies for its urine application are limited, and the corresponding reference values have not been reported extensively. We studied the long-term performance of a commercial HPLC method for urine amino acid analysis and established ...

The separation and on-line concentrations of lysergic acid diethylamide (LSD), iso-lysergic acid diethylamide (iso-LSD) and lysergic acid N,N-methylpropylamide (LAMPA) in human urine were investigated by capillary electrophoresis-fluorescence spectroscopy using sodium dodecyl sulfate (SDS) as an anionic surfactant. A number of parameters such as buffer pH, SDS concentration, Brij-30 concentrati...

The effects of mangiferin on uric acid excretion, kidney function and related renal transporters were investigated in hyperuricemic mice induced by potassium oxonate. Mice were divided into normal control group, and 5 hyperuricemic groups with model control, 50, 100, and 200 mg x kg(-1) mangiferin, and 5 mg x kg(-1) allopurinol. Mice were administered by gavage once daily with 250 mg x kg(-1) p...