ABSTRACT
A sensitive determination method for sulfur mustard ( HD ) metabolites thiodiglycol ( TDG ) in rabbit urine was established and validated using isotope dilution negative ion chemical ionization ( NICI) gas chromatography-mass spectrometry ( GC-MS ) , in which deuterated thiodiglycol ( TDG-d8 ) was used as internal standard. Two solid-phase extraction ( SPE) steps were established and optimized in order to reduce the interfering backgrounds, one was used to extract thiodiglycol ( TDG ) from urine with self-assemblied Florisil SPE cartridges, another cleaning treatment of the by-products after pentafluorobenzoyl chloride (PFBZ) derivatization. The results showed that the limits of detection quantitation of this method were 0. 1 and 0. 3 μg/L, respectively. The exposure time-response relationship and exposure dose-response relationship of TDG in rabbit urine were studied after rabbit skin exposure to sulfur mustard (HD, 0. 02-0. 15 LD50). The TDG levels in the rabbit urine increased rapidly during the first day after application and then decreased over time for all dosage groups. A secondary release was also noted for the high-dose group, and the duration of high TDG excretion levels was correlated positively with the HD dosage levels. We thus concluded that abnormally high levels of TDG in urine could be used as a clear diagnostic indicator of HD exposure.
ABSTRACT
Objective To investigate the influence of different carbon dioxide (CO2) absorbents (Dr(a)gersorb 800 plus , Sodasorb,Sodasorb LF) on the production of compound A during low-flow sevoflurane anesthesia.Methods Twenty-seven ASA Ⅰ or Ⅱ patients aged 20-64 years were randomly assigned to three groups according to different CO2 absorbents: Dr(a)gersorb 800 plus' group (group D, n = 10), Sodasorb group (group S, n = 10) and Sodasorb LF group (group LF, n = 7). Anesthesia was maintained with low-flow (500 ml/min) sevoflurane inhalation (with the end-tidal sevoflurane concentration of approximately 2% ). At 2 h after low-flow sevoflurane anesthesia, gas samples were taken from the expiratory limb of the circuit. Compound A was detected by gas chromatography. Serum alanine transaminase (ALT), aspartate aminotransferase (AST), bilirubin (BR), urea nitrogen (BUN) and creatinine (Cr) levels were measured before (T0 ) and 24 h after operation (T1).Results The three groups were comparable with respect to age, body weight and height. After 2 h of low-flow sevoflurane anesthesia, compound A concentrations in the expiratory limb of the circuit were 11.6 ± 5.8 (group D), 2.1 ± 1.9 (group S)and ＜ 0.1 ppm (group LF), respectively. There were no significant changes in the serum ALT, AST, BR, BUN and Cr levels at 24 h after operation as compared with the preoperative baseline values in the three groups.Conclusion After 2 h of low-flow (500 ml/min) sevoflurane anesthesia, compound A concentrations within the circuit with different CO2 absorbents ( Dr(a)gersorb 800 plus' , Sodasorb, Sodasorb LF) are less than 50 ppm, with the lowest in Sodasorb LF.However, they have no significant effects on hepatic or renal function.
ABSTRACT
Objective: To determine the long-term prognostic value of ~(99m)Tc-sestamibi (MIBI) Gated myocardial perfusion imaging(G-MPI)in patients with coronary artery disease.Methods: A total of 1345 consecutive symptomatic coronary artery disease patients who underwent ~(99m)Tc-MIBI G-MPI were studied.1250 patients were followed-up by telephone interview, the median follow-up time was 26.7±13.6 months.Events were defined as cardiac death, nonfatal myocardial infarction and revascularization by coronary artery bypass graft or percutaneous coronary artery intervention.Results: Cox regression analysis indicated that summed stress score (3.8±6.1,χ~2=67.25), summed different score (1.1±3.0,χ~2=21.09) and left ventricular ejection fraction (LVEF) (0.667±0.097,χ~2=42.26) were independent predictive factors of cardiac events (P<0.01).Kaplan-Meier analysis indicated that cardiac event free survival was significantly lower in the patient with LVEF≤50%.Conclusion: In Patients with symptomatic coronary artery disease, the summed stress score, summed rest score, summed different score and LVEF had prognostic value, and low LVEF indicated worse prognosis.