2.Spectrophotometric determination of trimethylamine-nitrogen in cadaver tissues for the estimation of late postmortem interval: a pilot study.
Qian, LIU ; Xiangyang, CAI ; Yan, LIU ; Lan, ZHOU ; Shaohua, YI ; Liang, LIU
Journal of Huazhong University of Science and Technology (Medical Sciences) 2008;28(6):630-3
To study the relationship between the late postmortem interval (PMI) and trimethylamine-nitrogen (TMA-N) in postmortem tissues of cadaver, TMA-N in muscles, livers and kidneys of rats was measured at different postmortem intervals (PMI) by using a modified spectrophotometric method. The results indicated that the detection sensitivity of TMA-N was 1 mg/L, and there was a good linear correlation between the value of absorbance (A value) and TMA-N at the concentration of 1-10 mg/L (R (2) = 0.9991). Although TMA variation in muscles was different from that in inner organs during the time since death, TMA-N changes in cadaver tissues was positively correlated with PMI. During 2 to 7 d since death, the best correlation between PMI and TMA-N concentration was found in muscles. With PMI as an independent variable, the cubic polynomial regression equation was y= -0.457x(3)+6.519x(2)-24.574x+27.207 (R (2)=0.969). During 3 to 8 days since death, PMI was best correlated with TMA-N concentration in inner organs. With PMI as the independent variable, the cubic polynomial regression equation was y=0.509x(3)-9.153x(2)+55.727x-95.819 (R (2)=0.953). It was concluded that TMA-N in tissues could be used as a new estimator for late PMI. The method used in this study offered advantages such as accuracy, sensitivity, little samples required and wide PMI estimation.
Cadaver
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Forensic Pathology
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Methylamines/*analysis
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Nitrogen/*analysis
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Pilot Projects
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Postmortem Changes
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Random Allocation
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Rats, Sprague-Dawley
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Spectrophotometry
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Time Factors
3.Study on influence of glucoside Tripterygium total tablets on metabolism in rats by NMR metabonomic technique.
Mengxiang SU ; Xuan GAO ; Min SONG ; Taijun HANG ; Wenbin SHEN ; Zhe SONG
China Journal of Chinese Materia Medica 2011;36(11):1449-1453
OBJECTIVETo investigate the toxic effects of Glucoside Tripterygium total on rats with nuclear magnetic resonance (NMR)-based metabonomic method.
METHODThe influence of intragastric administration of Glucoside Tripterygium total suspension at two different doses on endogenetic metabolites in normal rat urine was determined with bio-NMR method then analyzed by pattern recognition technique and partial least-squares discriminant analysis (PLS-DA). Histopathological analysis was carried out.
RESULTEscalations of concentrations of urinary taurine, TMAO and glucose as well as reductions of concentrations of urinary citrate and 2-oxoglutarate were found by analysis of the 1H-NMR spectra, which was coincident with the result of histopathological analysis. The result of pathological examination indicated that pathologic change was not observed in nephridial tissue, but there were obvious changes in hepatic tissue.
CONCLUSIONThe urinary metabomic spectra were closely associated with the hepatic toxicity, which manifested the mitochondrial dysfunctions, the abnormal energy metabolism in TCA cycle as well as the abnormal glucose metabolism.
Animals ; Citric Acid ; urine ; Enteral Nutrition ; Glucose ; metabolism ; Glucosides ; administration & dosage ; Ketoglutaric Acids ; urine ; Least-Squares Analysis ; Liver ; drug effects ; metabolism ; pathology ; Magnetic Resonance Spectroscopy ; methods ; Metabolomics ; Methylamines ; urine ; Plant Extracts ; administration & dosage ; Rats ; Tablets ; administration & dosage ; Taurine ; urine ; Tripterygium ; chemistry