Predictive value of bilirubin and serum γ-glutamyltranspeptidase levels in type-2 diabetes mellitus patients with acute coronary syndrome.

BACKGROUND: Cardiovascular disease is a major complication of diabetes mellitus (DM). Type-2 DM (T2DM) is associated with an increased risk of cardiovascular events and mortality, while serum biomarkers may facilitate the prediction of these outcomes. Early differential diagnosis of T2DM complicated with acute coronary syndrome (ACS) plays an important role in controlling disease progression and improving safety. AIM: To investigate the correlation of serum bilirubin and γ-glutamyltranspeptidase (γ-GGT) with major adverse cardiovascular events (MACEs) in T2DM patients with ACS. METHODS: The clinical data of inpatients from January 2022 to December 2022 were analyzed retrospectively. According to different conditions, they were divided into the T2DM complicated with ACS group (T2DM + ACS, n = 96), simple T2DM group (T2DM, n = 85), and simple ACS group (ACS, n = 90). The clinical data and laboratory indices were compared among the three groups, and the correlations of serum total bilirubin (TBIL) levels and serum γ-GGT levels with other indices were discussed. T2DM + ACS patients received a 90-day follow-up after discharge and were divided into event (n = 15) and nonevent (n = 81) groups according to the occurrence of MACEs; Univariate and multivariate analyses were further used to screen the independent influencing factors of MACEs in patients. RESULTS: The T2DM + ACS group showed higher γ-GGT, total cholesterol, low-density lipoprotein cholesterol (LDL-C) and glycosylated hemoglobin (HbA1c) and lower TBIL and high-density lipoprotein cholesterol levels than the T2DM and ACS groups (P < 0.05). Based on univariate analysis, the event and nonevent groups were significantly different in age (t = 3.3612, P = 0.0011), TBIL level (t = 3.0742, P = 0.0028), γ-GGT level (t = 2.6887, P = 0.0085), LDL-C level (t = 2.0816, P = 0.0401), HbA1c level (t = 2.7862, P = 0.0065) and left ventricular ejection fraction (LEVF) levels (t=3.2047, P = 0.0018). Multivariate logistic regression analysis further identified that TBIL level and LEVF level were protective factor for MACEs, and age and γ-GGT level were risk factors (P < 0.05). CONCLUSION: Serum TBIL levels are decreased and γ-GGT levels are increased in T2DM + ACS patients, and the two indices are significantly negatively correlated. TBIL and γ-GGT are independent influencing factors for MACEs in such patients.

[Determination of 2, 4-toluenediamine in urine by gas chromatography].

OBJECTIVE: To establish a method for determining the content of 2,4-toluenediamine, a urinary metabolite of toluene diisocyanate, by gas chromatography. METHODS: Urine samples were collected, and acidification, extraction, derivatization, separation with a capillary column, and detection with an electron capture detector were performed. The target compound was qualified by retention time and quantified by peak area. RESULTS: The concentration of 2, 4-toluenediamine showed a linear relationship with peak area within 0.0∼40 ng/ml, with a correlation coefficient 0.9995; the limit of detection was 0.44 ng/ml, the lower limit of quantification was 1.47 ng/ml, the relative standard deviation was 1.85%∼4.05%; the recovery rate was 97.98%∼99.28%. CONCLUSION: The method has the advantages of high sensitivity and high accuracy and can be used for determination of 2, 4-toluenediamine in urine.

[Detecting 2-butoxy ethanol in the air of workplaces by gas chromatography].

OBJECTIVE: To establish a gas chromatographic method for detecting 2-butoxy ethanol in the air of workplaces. METHODS: After the air samples were collected with activated carbon tubes and desorbed with methylene chloride/methanol, the target toxicant was separated with FFAP capillary columns and detected with flame ionization detector, qualified by retention time and quantified by peak area. RESULTS: The linear range of 2-butoxy ethanol in air of workplace was 56.3 ∼ 901.0 µg/ml, the correlation coefficient was 09999. The limit of detection was 2.0 µg/ml. The limit of quantity was 5.0 µg/ml. The minimal detecting concentration was 0.27 mg/m(3) in the condition of 7.5L sampling volume and 1ml desorbed volume. Relative standard deviation was 3.04% ∼ 7.93% and the recovery was 92.7% ∼ 95.5%. CONCLUSION: In present study the detecting method with high sensitivity, precision and accuracy can be used to determine 2-butoxy ethanol in the air of workplaces.

[Determination of phosphorus oxychloride in the air of workplace by ion chromatography].

OBJECTIVE: To establish a ion chromatography method for determination of phosphorus oxychloride in the air of workplace. METHOD: The phosphorus oxychloride in the air of workplace was collected by absorb liquid and turned into hydrochloric acid, then separated in column and detected with conductivity detector, qualified by elution time and quantified by peak height or peak area. RESULTS: The linear range of phosphorus oxychloride in air of workplace was 0.72 ∼ 5.76 µg/ml with its correlation coefficient 0.9999. The detecting limit of the method was 0.12 µg/ml. The smallest detecting concentration of the method was 0.08 mg/m(3) for 15 L sampling air. Relative standard deviation was 3.3% ∼ 6.2% and the recovery was 97.8% ∼ 103.8%. The sample could be resaved at room temperature at least for seven days. CONCLUSION: The indicators of the method correspond GBZ/T 210.4-2008«Guide for establishing occupational health standards-Part 4: Determination methods of air chemicals in workplace¼. It is a good method to determine phosphorus oxychloride in the air of workplace.

[Evaluating the uncertainty in urinary fluoride measurement by ion selective electrode method].

OBJECTIVE: To evaluate the uncertainty of measurement result of urinary fluoride and to provide quality assurance for determinations. METHOD: The investigation was conducted, according with principles and methods for uncertainty evaluation. RESULTS: The uncertainty of the combined standard of present method was 2.86 %. For the sample containing 4.47 mg/L urinary fluoride, the expanded uncertainty was 0.26 mg/L. CONCLUSION: The uncertainty of the present method was mainly from the sample repeatability, the preparation of standard solution, the linearity of the calibration curve and instruments and so on.