1.Application of DNA extraction automation workstation in the forensic area
Qiongyu ZHANG ; Mei DING ; Baojie WANG ; Hao PANG ; Wei HE
Chinese Journal of Forensic Medicine 2010;25(1):40-42
Automation workstation refers to a kind of fully automatic platform,which use the automatic technology to analysis,processe batches of biological samples.It can finish liquid handling,transfering,mixing and other operatious in short time,particularly suitable for PCR templates'preparation of large amount of biological samples.This article mainly discusses the basic patterns,methods and forensic applications of automated DNA extraction workstation,aimed at making the technology more widely applied in forensic DNA analysis.
2.The development of research on determination methods of buprenorphine
Zhonghui ZHANG ; Ruihua WANG ; Zhongshan YU
Chinese Journal of Forensic Medicine 2010;25(1):36-39
Buprenorphine,one kind of new drugs,is abused in recent years.In this review,some determination and extraction methods for buprenorphine are introduced.The relative merits of liquid-liquid extraction,solid phase extraction,hydrolysis and derivatization methods are compared.The analytical methods such as TLC,GC,GC/MS and LC,LC/MS are discussed.
3.Progress in mechanisms of methamphetamine-induced dopaminergic neurotoxicity
Xiaofeng ZENG ; Gang LU ; Zhen LI
Chinese Journal of Forensic Medicine 2010;25(1):33-36
Methamphetamine is a powerful stimulant of amphetamine type in the central nervous system (CNS),and recently it has become the major drugs of abuse.A lot of research results show that MA may induce dopaminergic neurotoxicity in the animal and human striatum.The mechanisms include effects on dopaminergic signaling and dopamine oxidation,glutamate induced excitotoxicity,oxidative stress and inflammatory cytokines,disruption of mitochondfia,apoptosis,activation of glial cells and hyperthermia.However the mechanisms by the MA-induced dopaminergic neurotoxicity are not completely understood.The paper reviewed recent progress of study on them to provide reference materials for related research.
4.Estimation of postmortem interval by determination of K~+ concentration in aqueous humor
Guoli LV ; Yaping ZHOU ; Zhigang LI ; Xinshu XU ; Licong YU ; Xin WANG ; He SHI ; Chuanchao XU
Chinese Journal of Forensic Medicine 2010;25(1):24-26
Objective To investigate the applicability of the K~+ concentration in aqueous humor to estimate postmortem interval(PMI).Methods 30 White New-Zealand rabbit were sacrificed by air embolism and divided into 10 groups.Aqueous humor and vitreous humor were sampled at 0.5h,1h,3h,6h,8h,12h,16h,20h,and 24h after death.The concentration of potassium,sodium and calcium were analyzed by an autoanalyzer and the data were statistically processed by SPSS software for Windows.Results Increase in potassiam concentration in aqueous humor was correlated with the postmortem interval(R~2=0.956).Conclusion Measurement of potassium concentration in aqueous humor may be used for PMI estimation.
5.Determination of ganciclover in human plasma by reversed-phase high performance liquid chromatography
Ming JIN ; Qiangfeng LI ; Fei HUANG ; Liwei GAO ; Jin LIU
Chinese Journal of Forensic Medicine 2010;25(1):30-32
Objective To develop a method for the determination of ganciclover in human plasma by RPHPLC.Methods Plasma containing ganciclover was extracted with methanol and methylene chloride,qualitative and quantitative analysis was carried out directly.Working curve,linear range,recovery,precision and so on was obtained according to the sample pre-processing method and analysis state.The HPLC method has been taken to investigate the plasma concentration of ganciclover for 12 volunteers.Results The relationship of the peak area of ganciclover concentration in plasma linear within the range of 0.05 μg/mL~1.60 μg/mL(r=0.9999).The lowest detection limit was 0.01 μg/mL(S/N≥13).The intra and inter-day RSD were less than 5.1%respectively.The recovery is about 90.0%~95.4%.Conclusion The established method in the article was shown to be sensitive,accurate and simple for the determination of ganciclover level.It is suitable for clinical detection of ganciclover and forensic medicine and toxicology analysis.
6.A study on the effect of preservatives on the stability of carboxyhemoglobin in the blood samples
Gaoqin ZHANG ; Daming ZHANG ; Chaojin SONG ; Keming YUN ; Ai WANG
Chinese Journal of Forensic Medicine 2010;25(1):20-23
Objective To investigate the effect of conventional preseratives on the stability of carboxyhemoglobin(HbCO)in the stored blood samples.Methods Blood samples with 30%~40% and 60%~70% of HbCO were established,respectiviely.The samples were stored with the commomly used preseratives including formaldehyde,sodium fluoride,EDTA-Na_2,sodium nitrite,potassium oxalate,heparin sodium,sodium citrate and the mixture of sodium fluoride and sodium citrate(1:3).Saturation of HbCO in the preserved blood samples were determined at 0h,2h,8h,24h,3d,and 7d after treatment with the addictives,respectively.The data were evaluated statistically.Results The stability of HbCO was significantly affected in the formaldehyde and sodium nitrite-treated samples,but no significant effects of the other preseratives on the blood samples were detected.Conclusion The stability of HbCO in the blood samples conserved varies with the type of the preseratives used.The samples taken from cases with suspected death from carbon monoxide poisoning should be kept with proper preseratives.Blood samples preserved with formaldehyde and sodium nitrite are not suitable for HbCO determination.
7.A study on the influence of ethanol on the toxicokinetics of ketamine in rabbits
Yujin WANG ; Juan JIA ; Ling LIU ; Zhiwen WEI
Chinese Journal of Forensic Medicine 2010;25(1):13-16
Objective To investigate the influence of ethanol on the toxicokinetic profiles of ketamine and its main metabolite norketamine in rabbits.Methods Ketamine hydroehloride Wills administered orally to the rabbits at a dose of 15mg/kg in the ketamine-treated group.Ketamine hydrochloride combined with ethanol at a dose of 15 mg/kg and 3.0g/kg respectively was administered orally to those of the ethanol-coadministration group.The serum and urine samples were collected before administration and at different time points after drug delivery.The concentrations of ketamine and norketamine were determined by GC and GC/MS.Compartment model and toxicokinetics parameters were assessed by WinNorLin program.Results The mean serum concentration-time profile of ketamine after oral administration was fitted to a two-compartment open model with first order kinetics and not affected by ethanol.The K_(10),AUC and β of ketamine in rabbits of ethanol-coadministration group increased as compared with those of ketamine-treated rabbits,while T_(1/2K_(10)),T_(1/2β),A and C_(max)decreased(P<0.05).Meanwhile,the K01,A,B and C_(max) of norketamine,the metabolite of ketamine increased in ethanol-coadministration group and T_(1/2K01) and Tmax were lowered than those in ketaminetreated group(P<0.05).Difference of the other toxicokinetics parameters including V/F,K_(10),K_(12),K_(21),AUC,T_(1/2K_(10)),T_(1/2α),T_(1/2β) and β were not statistically significant between two groups(P>0.05).Conclusion Ethanol may accelerate elimination of ketamine and the metabolism of ketamine to norketamine and has little effect on the absorption of ketamine,suggesting that interaction between ethanol and ketamine should be considered in cases of co-abuse of the two drugs.
8.The extraction of sperm DNA from mixed stain using DNase-Ⅰ purification combined with alkaline lysis method
Zichuang YUAN ; Hongnian JING ; Yue LAI ; Huijun WANG ; Hongying CHEN
Chinese Journal of Forensic Medicine 2010;25(1):10-12
Objective To establish a method of sperm DNA extraction in mixed stain by using DNase-Ⅰ purificationcombined with alkaline lysis method in forensic science.Methods 79 mixed stain samples of criminal cases were collected.Sperm DNA was extracted using the purification of DNase-Ⅰ binding alkaline lysis method.16 STR loci were genotyped with fluorescent multiplex amplification system.The typing results were compared with that of extracted using two-step differential extraction procedure.Results Of all 79 mixed stain samples,64 samples were genotyped successfully by using DNase-Ⅰ purification combined with alkaline lysis method while 57 samples were genotyped successfully with two-step differential extraction procedure.There was significant difference between two methods(P=0.039).The purification of DNase-Ⅰ binding alkaline lysis method had a higher success rate and lower cost than that of two-step differential extraction procedure.Conclusion Purification of DNase-Ⅰ binding alkaline lysis method can increase the typing success rate of the mixed stain samples.The method is simple,rapid and easy to be automated,and suitable for forensic identification test.
9.Selection and evaluation of forensic application value of 48 X-SNP loci
Jingjing CHANG ; Li LI ; Suhua ZHANG
Chinese Journal of Forensic Medicine 2010;25(1):6-10
Objective To analyze and evaluate the 48 selected highly polymorphic SNP loci in Chinese Han population on genetic and forensic aspects.Methods Samples from 200 unrelated Han individuals in East China were collected.48 X-SNP polymorphic genetic markers were selected according to the information providedby NCBI and HapMap,and then were typed by SNPlex~(TM) System for establishing genetic data.Results The 48 X-SNP loci were highly polymorphic markers in East China Han population except rs6527549,and their polymorphism information contents(PIC)were all above 0.32,the discrimination power(DP)in females and males were above 0.56 and 0.40 respectively,the probability of exclusion(PE)in duos and trios were above 0.20 and 0.32 respectively.In addition,linkage disequilibriums were observed among some loci.Conclusion The 48 X-SNP loci union is suitable for developing high-throughout automated research and also useful for special parentage testing.
10.The detectable time limit of intact STR profile for human tissues in unbuffered formalin
Yan LIU ; Li LI ; Zhenmin ZHAO ; Yuan LIN ; Tingzhi QUE
Chinese Journal of Forensic Medicine 2010;25(1):1-5
Objective To evaluate the STR profiling availability of formalin-fixed tissues and the detectable time limit of intact STR profile.Methods The different human tissues were fixed with 10-fold diluted commercial 40%formalin fixative for different duration under 15~20℃,and then DNA was extracted using the method of QIAamp~(R)DNA and IQ~(TM) DNA System.The extracted DNA was quantified with QuantifilerTM kit and amplified by both AmpFSTR identifiler kit and AmpFSTR MiniFiler kit.The STR profile was analyzed by GeneMapper ID v3.2 on 3100-Avant.Resuls The STR profiling availability of formalin-fixed tissues was relevant to the formalin fixing duration mainly.as well as the type of tissues and the template concentration and protocol of DNA extracting.The optimal ranges of template concentration is 1~3ng/μL and the QIAamp extracting method was preferable.There are differences in the degradation rate between various types of tissues in the unbuffered formalin fixative,and the lung tissue showed the slowest rate and liver and intestine tissues the fastest.Intact miniSTR profile of all the tissues detected could be obtained within 15 days duration of formalin fixing while intact STR profile could be obtained within 4 days.Conclusion The major factor that impact the availability of STR profiling of formalin-fixed tissues is the fixing duration in unbuffered formalin,as well as the type of tissues,method of extraction,concentration of PCR template and the kinds of STR loci.