The objectives of this study were to develop optimal analytic methods for detecting urinary 2-thiothiazolidine-4-carboxylic acid (TTCA) and thiocarbamide simultaneously and to evaluate the usefulness of these metabolites to a biological exposure index (BEI) for carbon disulfide (CS2) exposure. For this experiment, synthesized TTCA and thiocarbamide were used. The synthesized TTCA was identified by infrared spectrophotometer, nuclear magnetic resonance spectrometer and thin layer chromatography. The recovery rates of both metabolites were calculated to find the optimum analytical method. The amounts of urinary TTCA and thiocarbamide were measured by using an ultraviolet detector connected to high performance liquid chromatography (HPLC) after the administration of CS2 (350, 700 mg/kg) into Sprague-Dawley rats intraperitoneally. The maximum absorbance wave lengths for TTCA and thiocarbamide were 272 and 236 nm, respectively. Ethyl acetate extraction with NaCl as a salting-out reagent was used as a simultaneous extraction method for these metabolites. HPLC conditions for these metabolites included using a NH2 column, 50 mM KH2PO4: acetonitrile (85:15) and pH 3. Excreted amounts of urinary TTCA and thiocarbamide were increased significantly following CS2 administration. TTCA, which was already adopted as a BEI for CS2 by the American Conference of Governmental Industrial Hygienists (ACGIH), seems to be a more useful BEI for CS2 exposure than thiocarbamide. However further studies are needed to increase analytical efficiency before thiocarbamide can be adopted as a BEI and to apply this analytic method for simultaneous analysis of these metabolites in workers exposed to CS2.
Animal ; Carbon Disulfide/pharmacology* ; Environmental Exposure* ; Rats ; Rats, Sprague-Dawley ; Thiazoles/urine* ; Thiourea/urine* ; Urea/urine*

Objective: To establish a high performance liquid chromatography method for the determination of 2-thioxothiazolidine-4-carboxylic acid (TTCA) in urine. Methods: After acidification with hydrochloric acid, TTCA in urine was first extracted by ethyl acetate with excessive sodium chloride, then gradient separated by a symmetry C18 column and then detected by a diode array detector. The quantification was based on a working curve of external standard method. Results: The linear relationship of TTCA in urine was good in the range of 0.03-10.00 mg/L, and the correlation coefficient was 0.9999. The detection limit and minimum quantitative concentration of TTCA in urine were 0.008 mg/L and 0.027 mg/L. The intra-assay precision of the method was 0.9%-1.4%, the inter-assay precision was 1.3%-3.5%, and the average recovery was 85.0%-92.7% while the concentrations of TTCA in urine was 0.8, 2.0 and 8.0 mg/L, respectively (n=6) . Conclusion: The gradient elution high performance liquid chromatography method has simple operation and high sensitivity, and it is suitable for the determination of TTCA on a low level in urine for occupational workers exposure to carbon disulfide.
Carbon Disulfide ; Chromatography, High Pressure Liquid/methods* ; Humans ; Thiazoles/urine* ; Thiazolidines ; Thiones

OBJECTIVETo study the urinary excretion pattern for of 2-thio-thiazolidine-4-carboxylic acid (TTCA) in workers exposed to CS2, so as to provide experimental basis for working out biomonitoring measures for short-term exposure to CS2.

METHODSSixty-nine subjects were divided into three groups: (1) fourteen volunteers who had not been exposed to CS2 before were exposed to CS2 for 2 hours, their urine samples were collected and analyzed at different time points; (2) The urine samples of 15 occupational exposure workers were collected on pre-shift, mid-shift, post-shift; (3) The relationship between 8 h time weighted average CS2 exposure concentrations (PC-TWA) and TTCA levels of post-shift urine was studied among 40 workers chronically exposed to CS2.

RESULTS(1) In the 1st group, urine TTCA level reached the peak [(1.03 +/- 0.72) mg/gCr] 4 h after exposure; (2) In the 2nd group, urine TTCA level on pre-shift [(0.37 +/- 0.28) mg/gCr] was lower than that on mid-shift [(1.23 +/- 0.71) mg/gCr, P<0.01] and post-shift [(1.31 +/- 0.78) mg/gCr, P<0.01]; (3) In the 3rd group, there was a linear relationship between the post-shift urine TTCA level and 8 h CS2 exposure concentrations dose (PC-TWA). The regression equation is Y(TTCA mg/gCr)=1.163 6X(CS2 mg/m3)-5.411 6.

CONCLUSIONThe post-shift urine TTCA levels may be regarded as a bio-monitoring index for workers exposed to CS2.

Adult ; Carbon Disulfide ; metabolism ; Environmental Monitoring ; Humans ; Male ; Middle Aged ; Occupational Exposure ; Thiazoles ; urine ; Thiazolidines

Drug-induced interstitial nephritis is one cause of acute kidney injury. Although traditional remedies have been widely used in South Korea, Corni fructus-induced interstitial nephritis has not been reported in the general population. A 65-year-old female patient was admitted with sudden onset of gross hematuria after ingesting Corni fructus tea for 2 weeks. Her initial lab findings showed a blood urea nitrogen level of 35.1 mg/dL, creatinine level of 1.7 mg/dL, albumin level of 4.5 g/dL, and hemoglobin level of 10.3 g/dL. Urinalysis revealed SG (1.025), blood (many), protein (+), and WBC (0-3/HPF). Her 24-hour total protein level was 1,120 mg/day. No specific abnormalities were found on serum and urine protein electrophoresis. Kidney biopsy demonstrated severe mononuclear cell infiltration into the renal interstitium with mild tubular atrophy and pericapsular fibrosis. Immediate withdrawal of Corni fructus, appropriate education, and conservative management resulted in gradual restoration of her renal function. This case implies that Corni fructus may be a causative allergen that induces acute interstitial nephritis in some patients.
Acute Kidney Injury ; Aged ; Atrophy ; Biopsy ; Blood ; Blood Urea Nitrogen ; Cornus ; Creatinine ; Education ; Electrophoresis ; Female ; Fibrosis ; Hematuria ; Hemoglobins ; Humans ; Kidney ; Nephritis, Interstitial* ; Pyridines ; Republic of Korea ; Tea ; Thiazoles ; Urinalysis ; Urine

Drug-induced interstitial nephritis is one cause of acute kidney injury. Although traditional remedies have been widely used in South Korea, Corni fructus-induced interstitial nephritis has not been reported in the general population. A 65-year-old female patient was admitted with sudden onset of gross hematuria after ingesting Corni fructus tea for 2 weeks. Her initial lab findings showed a blood urea nitrogen level of 35.1 mg/dL, creatinine level of 1.7 mg/dL, albumin level of 4.5 g/dL, and hemoglobin level of 10.3 g/dL. Urinalysis revealed SG (1.025), blood (many), protein (+), and WBC (0-3/HPF). Her 24-hour total protein level was 1,120 mg/day. No specific abnormalities were found on serum and urine protein electrophoresis. Kidney biopsy demonstrated severe mononuclear cell infiltration into the renal interstitium with mild tubular atrophy and pericapsular fibrosis. Immediate withdrawal of Corni fructus, appropriate education, and conservative management resulted in gradual restoration of her renal function. This case implies that Corni fructus may be a causative allergen that induces acute interstitial nephritis in some patients.
Acute Kidney Injury ; Aged ; Atrophy ; Biopsy ; Blood ; Blood Urea Nitrogen ; Cornus ; Creatinine ; Education ; Electrophoresis ; Female ; Fibrosis ; Hematuria ; Hemoglobins ; Humans ; Kidney ; Nephritis, Interstitial* ; Pyridines ; Republic of Korea ; Tea ; Thiazoles ; Urinalysis ; Urine