Metabolic abnormalities associated with ketamine-associated bladder toxicity based on metabolomics / 药学学报

The aim of the present study was to determine the metabolic changes and possible toxic mechanisms of ketamine-associated bladder toxicity. Twenty-four male Sprague-Dawley (SD) rats were randomly allocated into a control group, a low-dose group and a high-dose group. The behavior of these rats was observed every day. In addition, the weight, 2 h urinary frequency and organ coefficient of the bladder were measured. Serum IL-6 and TNF-α levels were measured using an enzyme-linked immunosorbent assay (ELISA). Urinary metabolites were analyzed using gas chromatography-mass spectrometry (GC-MS). This research was approved by the Ethics Committee of the Animal Experiment Center of Southwest Medical University (No. 201901-98). After 12 weeks of administration, the frequency of 2 h urination and the bladder mass index were significantly different in the low-dose and high-dose groups compared with the control group. Serum IL-6 and TNF-α levels were higher than those of the control group (P<0.05). Bladder HE staining showed that long-term administration of ketamine could induce cystitis. The concentrations of the three common differential metabolites, including 3-aminoisobutyric acid, citric acid and uric acid in the low-dose and the high-dose groups were increased compared with those in the control group. This study indicates that 3-aminoisobutyric acid, citric acid and uric acid and their related metabolic pathways may be closely related to ketamine-associated bladder toxicity.

Estimation of Early Postmortem Interval of Asphyxial Death Rats at Different Ambient Temperatures by GC-MS-Based Metabolomics / 法医学杂志

Objective To establish the orthogonal partial least square （OPLS） model for the estimation of early postmortem interval （PMI） of asphyxial death rats in four ambient temperatures based on gas chromatography-mass spectrometry （GC-MS） metabolomics. Methods The 96 rats were divided into four temperature groups （5 ℃, 15 ℃, 25 ℃ and 35 ℃）. Each temperature group was further divided into 3 h, 6 h, 12 h and 24 h after death, and 6 other rats were taken as the control group. The cardiac blood was collected at the set time points for the four temperature groups and 0 h after death for the control group for the metabolomics analysis by GC-MS. By OPLS analysis, the variable importance in projection （VIP）>1 and the result of Kruskal-Wallis test P<0.001 were used to screen out the differential metabolite related to PMIs in the cardiac blood of rats of different temperature groups. Then OPLS regression models of different temperature groups were established with these metabolites. At the same time, a prediction group for investigating the prediction ability of these models was set up. Results Through the analysis of OPLS, 18, 15, 24 and 30 differential metabolites （including organic acids, amino acids, sugars and lipids） were screened out from the rats in groups of 5 ℃, 15 ℃, 25 ℃ and 35 ℃, respectively. The prediction results of the four temperature group models showed that the prediction deviation of 5 ℃ model was larger than that of other groups. The prediction results of other temperature groups were satisfactory. Conclusion There are some differences in the changes of metabolites in cardiac blood of rats at different ambient temperatures. The influence of ambient temperature should be investigated in the study of PMI estimation by metabolomics, which may improve the accuracy of PMI estimation.

Relationship between Blood Acetaldehyde Concentration and Psychomotor Function of Individuals with Different ALDH2 Genotypes after Alcohol Consumption / 法医学杂志

Objective To explore the change rules of blood ethanol and blood acetaldehyde concentration, the impairment of psychomotor functions of different acetaldehyde dehydrogenase （ALDH） 2 genotype individuals after alcohol consumption and the relationship among them. Methods The ALDH2 genotypes in seventy-nine healthy volunteers were obtained by SNaPshotTM method, then divided into ALDH2*1/*1 （wild type） and ALDH2*1/*2 （mutant type） group. After volunteers consumed 1.0 g/kg of alcohol, blood ethanol concentration and blood acetaldehyde concentration at a series of time points before and after alcohol consumption and psychomotor functions, such as, visual selective response time, auditory simple response time and tracking experiment were detected. Biphasic alcohol response questionnaires were collected. Results After alcohol consumption, ALDH2*1/*2 group's blood ethanol and blood acetaldehyde concentration reached the peak earlier than ALDH2*1/*1 group. Its blood acetaldehyde concentration was higher than that of ALDH2*1/*1 group, 1-6 h after alcohol consumption. The psychomotor functions, such as visual selective response time and auditory simple response time in ALDH2*1/*2 group were more significantly impaired than those in ALDH2*1/*1 group after alcohol consumption. There was no statistical significance between the two groups in excitement or sedation reactions （P>0.05）. Pearson correlation coefficient test showed that blood acetaldehyde concentration was related with psychomotor function. Conclusion There are significant differences between the psychomotor function of ALDH2 wild type and mutant type individuals after alcohol consumption estimated to be related to the difference in blood acetaldehyde concentration after alcohol consumption.

Correlation of Genetic Polymorphism, Alcoholic Beverage Type and Ethanol Metabolism / 法医学杂志

Objective To explore the effects of A DH1B and A LDH2 gene polymorphism and type of al-coholic beverage on ethanol metabolism, to provide data support for cases involving the interpretation of ethanol metabolism or back calculation of blood ethanol concentration in forensic practice. Methods A total of 81 volunteers were selected. The genotypes of A DH1B, A DH1C and A LDH2 were obtained by a multiplex SNaPshot genotyping method. Each subject was administered with 1.0 g/kg of alcohol. About 1 mL venous blood was collected before and after the alcohol consumption at 30 min, 45 min, 1 h, 1.5 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h and 8 h, respectively. The concentrations of ethanol and acetaldehyde in blood were determined by headspace gas chromatography. The peak times of blood ethanol concentration (Tmax), the peak mass concentrations of ethanol (Cmax), the area under curve (AUC) of ethanol (AUCethanol), AUCacetaldehyde and ethanol elimination rates (β) were calculated. In order to eliminate the influence of A DH1C, the A DH1C*1/*1 carriers were grouped based on the genotype of A DH1B and A LDH2. The data of each group were evaluated by one-way analysis of variance and pairwise comparison tests were performed by least significant difference method. The gene interactions were evaluated by two-way analysis of variance. Each parameter of three kinds of alcoholic beverage (white wine, red wine and beer) among groups was analysed by variance analysis with randomized block design. Results There were no differences in the value of Tmax and Cmax between the groups with different A DH1B and A LDH2 genotype. The differences in the values of AUCethanol, β and AUCacetaldehyde among some groups carrying different A DH1B and A LDH2 geno-type had statistical significance, while no significant difference was observed in these parameters when one individual taking same dose of different alcoholic beverage type. Conclusion The ethanol metabolism is associated with the related gene polymorphism, which is barely affected by alcoholic beverage type.

Relationship among ALDH2 gene polymorphism, alcohol metabolism and acetaldehyde level in peripheral blood / 法医学杂志

OBJECTIVE@#To explore alcohol pharmacokinetics as well as acetaldehyde level in peripheral blood in human subjects with different ALDH2 genotypes after drinking.@*METHODS@#Venous blood samples of 14 unrelated volunteers were collected. Polymerase chain reaction-restriction fragment length polymorphism technology was adopted for DNA extraction and ALDH2 genotyping. The volunteers were asked to drink beer at certain doses. The concentration of alcohol and acetaldehyde were assayed by headspace gas chromatography method at different time. The pharmacokinetic parameters were calculated.@*RESULTS@#According to the results of electrophoresis, 5 people carried ALDH2*1/*1 as wild group and 9 people carried ALDH2*1/*2 as mutation group. The good linear range of alcohol and acetaldehyde were 0-1 570.7 microg/mL and 0-5.1772 microg/mL, respectively. The AUC values of alcohol and acetaldehyde and the t1/2Z value of alcohol were higher in the mutation group than that in the wild group. But the CL/F value of alcohol was lower in the mutation group than that in the wild group (P<0.05).@*CONCLUSION@#After the consumption of alcohol, alcohol and acetaldehyde metabolism in blood slow down in ALDH2*1/*2 mutation group influenced by the inhibition of enzyme activity, leading to the accumulation of acetaldehyde in peripheral blood, thus reinforcing their effects in the body.

Determination of cinobufagin and resibufogenin in liver tissue by HPLC-MS/MS / 法医学杂志

OBJECTIVE@#To develop a sensitive and accurate assay for detecting cinobufagin and resibufogenin in liver tissue using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).@*METHODS@#The homogenization of liver tissue with internal standard dexamethasone was extracted with dichloromethane. The extracts with methanol were purified through ProElut C18 solid phase extraction and tested in positive electrospray ionization with multiple reaction monitoring of HPLC-MS/MS.@*RESULTS@#The good linear relationship of cinobufagin and resibufogenin in liver tissue were 1-204 ng/g and 1-206 ng/g, respectively. The minimal detection threshold (S/N > or = 3) of this method was 0.3 ng/g for both cinobufagin and resibufogenin. The matrix effect was 96.5%-126.7%. The extraction recovery coefficient was 70.0%-82.3%. The precision of intra-day and inter-day was less than 10%.@*CONCLUSION@#This method is sensitive and reliable, and can be used in forensic toxicological analysis.

LC-MS/MS analysis of determination of strychnine and brucine in formaldehyde fixed tissue / 法医学杂志

OBJECTIVE@#To establish a method for determination of strychnine and brucine in formaldehyde fixed tissue by LC-MS/MS analysis.@*METHODS@#The samples were pretreated with solid phase extraction using SCX cartridges and separated on SB-C18 column with mobile phase 0.1% formic acid : 0.1% formic acid-acetonitrile (75:25). Electrospray ionization (ESI) source was utilized and operated in positive ion mode. Multiple reactions monitoring (MRM) mode was applied. External standard method was applied for quantitation.@*RESULTS@#The chromatographic separation of strychnine and brucine in formaldehyde fixed nephritic and hepatic tissues resulted successfully. The standard curve was linear in the range of 0.002-2.0 microg/g for strychnine and brucine in formaldehyde fixed tissues, and the correlation coefficient was more than 0.996. The limits of detection (LOD) of strychnine and brucine in nephritic tissues were 0.06ng/g and 0.03 ng/g, respectively. The LOD of both chemicals were 0.3 ng/g in hepatic tissues. The extraction recovery rate was more than 74.5%. The precision of intra-day and inter-day were both less than 8.2%.@*CONCLUSION@#Strychnine and brucine can be sensitive to be determined in formaldehyde fixed tissue by LC-MS/MS analysis. It can be applied in the forensic toxicological analysis.

Analysis of multiple cephalosporins in blood and urine by HPLC / 法医学杂志

OBJECTIVE@#To establish a new high performance liquid chromatography (HPLC) method for determining the concentration of cefazolin, cefradine, cefoperazone and cefotaxime in blood and urine, as well as to investigate its applicability.@*METHODS@#Protein in blood and urine was precipitated directly by acetonitrile with acetanilide was used as the internal standard using Agilent Zorbax SB-Aq column (250 mm x 4.6 mm, 5 microm). The mixed solvents of water (triethylamine 0.12%, acetic acid 0.12%) and acetonitrile were used as the mobile phase to separate cephalosporins using gradient elution method at 1 mL/min (flow rate) and 254 nm (detection wavelength).@*RESULTS@#The working curve of four cephalosporins showed a good correlation (r = 0.9993), with the detection limit up to 0.01 microg/mL. The recovery rate was more than 81.2%.@*CONCLUSION@#This method is fast, easy and accurate. It is suitable for biological analysis of the 4 cephalosporins of the blood and urine in practical cases.

Analysis of paraquat in blood and urine by sodium borohydride/nickel chloride chemical reduction-gas chromatography/thermionic specific detector / 法医学杂志

OBJECTIVE@#To establish a new method for the analysis of paraquat in blood and urine by sodium borohydride/nickel chloride chemical reduction-gas chromatography/thermionic specific detector.@*METHODS@#An initial procedure of precipitation was performed by adding hydrochloric solution with sodium chloride and a mixture of chloroform and ethanol. Then the analyte contained in supernatant was reduced by a reduction system of sodium borohydride and nickel chloride and extracted by acetic ether. Ethyl paraquat (EPQ) was used as internal standard. GC/TSD was used to identify and quantify the analyte.@*RESULTS@#The limits of detection (S/N=3) in blood and urine were 0.002 and 0.004 microg/mL, respectively. The linear ranges were 0.050-30.0 microg/mL. Correlation coefficients in blood and urine were 0.999 and 0.998, respectively. The recoveries exceeded 80% both in blood and urine.@*CONCLUSION@#This method is applicable for quantification of paraquat in biological fluids.

Comparison of the contents of ATP, ADP, and AMP in the cardiac muscle of rat killed by different manners / 法医学杂志

OBJECTIVE@#The content changes of energy substances in the cardiac muscle of rat killed by different manners were investigated to elucidate evidence that can be used to determine the modes of death and postmortem interval.@*METHODS@#One hundred and eighty rats were randomly allocated into 3 groups and killed by bleeding, suffocating, and neck breaking, respectively. The contents of ATP, ADP, and AMP in the cardiac muscle of rats killed by the different manners at different death intervals (0, 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12, 18, and 24 h) were measured by HPLC.@*RESULTS@#There were significant differences observed in the contents of ATP and AMP in the rats' cardiac muscle in different groups at most of the intervals (P < 0.05) and at all of the intervals within the same group (P < 0.01), but no differences were found in the ADP contents in any of the group at most of the intervals.@*CONCLUSION@#The content changes of energy substances (ATP and AMP) in the cardiac muscle of dead rats may provide a basis for determination of the death manners and postmortem intervals.

Determination of ketamine and its metabolites in biological samples / 法医学杂志

The abuse of ketamine has gained popularity in recent years. It is important to develop rapid and accurate methods to determine ketamine and its metabolites in biological samples. The metabolites of ketamine are norketamine and dehydronorketamine in vivo. At present, there are blood, urine, hair and so on as specimens for detection, while the methods include GC, GC/MS, HPLC, LC/MS, HPCE etc. In this paper, these methods used for ketamine and its metabolites were reviewed in order to provide some preference for the study in relative fields.

A study on the effect of methanal during determination of carbon monoxide in blood / 法医学杂志

OBJECTIVE@#To confirm whether formaldehyde disturb detecting carbon monoxide in blood. To give an evidence that can be used for detecting carboxyhemoglobin more accurately in carbon monoxide posioning appraises.@*METHODS@#Blood samples came from carbon monoxide poisoning and the health were collected. Regular methods for detecting carboxyhemoglobin were used. Observing and comparing the detection results between which were spiked with methanal and no spiked one were performed.@*RESULTS@#Methanal will affect the result of following experiments such as heating, adding NaOH, absorbed by PdCl2 and spectrophotometry.@*CONCLUSION@#The samples which contaminated by formaldehyde couldn't be used for detecting carboxyhemoglobin.

The research of the heroin and its metabolites analysis in clinical samples / 法医学杂志

Heroin can be metabolized easily in body and the mail metabolites are 6-MAM, morphine and so on. At present, there are urine, blood, hair and so on as specimens for detection, while the analytical technology conclude TLC, GC, HPLC, GC/MS, LC/MS, IA, CE etc. In this paper, these technologies used for heroin's metabolites were viewed in order to provide some reference to the study in relative field.