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Methamphetamine (MA) is an illicit stimulant that affects the central nervous system. Cytochrome P450 2D6 (CYP2D6) plays an important role in MA metabolism. Numerous allelic variants confer substantial variation in CYP2D6 activity among individuals. In the present study, we examined the frequencies of CYP2D6 alleles, including CYP2D6*1, *2, *4, *5, *10, *14A, *14B, *18, and *36, and multiplication, in 82 forensic autopsy cases of MA abusers and 567 autopsy cases in which MA was not detected (controls). Ultrarapid metabolizer (UM), extensive metabolizer (EM), intermediate metabolizer (IM), and poor metabolizer (PM) phenotypes were predicted from CYP2D6 genotypes. Of MA abusers, 64 subjects were predicted to be EM, 17 were IM, and 1 was UM. No MA abuser had the predicted PM phenotype. No significant differences in CYP2D6 phenotype frequencies were found between MA abusers and controls. MA and amphetamine (AMP) concentrations were measured in the right heart blood, left heart blood, peripheral external iliac blood, urine, pericardial fluid, and bone marrow of MA abusers. MA concentrations in urine and bone marrow were significantly higher in IM than in EM. AMP concentration was not associated with CYP2D6 phenotype in any body fluid. These results suggest that the MA concentration in body fluids is influenced by CYP2D6 phenotypes in the Japanese population., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Methamphetamine (MA) is an illicit psychostimulant that stimulates the release of catecholamines from sympathetic nerve terminals and is widely abused worldwide. Since catechol-O-methyltransferase (COMT) metabolizes catecholamines and mediates adrenergic, noradrenergic, and dopaminergic signaling responses, we investigated the effects of the COMT polymorphisms rs4633 and rs4680 on cerebrospinal fluid (CSF) catecholamine concentrations in autopsies of subjects who died of drug intoxication. 28 MA abusers and 22 fatal psychotropic drug intoxication cases were evaluated. No correlations were identified between rs4633 or rs4680 polymorphisms and CSF concentrations of adrenaline (Adr), noradrenaline (Nad), or dopamine (DA) in fatal psychotropic cases. However, among MA abusers, DA concentrations in the CSF were significantly higher in those with the T allele (CT and TT) of rs4633 than in CC genotype carriers (p=0.004). Moreover, among MA abusers, DA concentrations were significantly higher in those with the A allele (GA and AA) of rs4680 than in GG genotype carriers (p=0.017). In subsequent haplotype analyses of MA abusers, a strong correlation was identified between two COMT haplotypes and CSF DA concentrations (p=0.002). However, the CSF concentrations of Adr and Nad were not associated with COMT genotypes or haplotypes. The present results indicate that rs4633 and rs4680 polymorphisms influence CSF DA concentrations and MA toxicity in MA abusers., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Methamphetamine (MA) use sometimes causes rhabdomyolysis, which has been associated with mortality. We analyzed potential rhabdomyolysis-susceptibility genes from autopsy samples of 18 methamphetamine abusers. We examined mutations in the ryanodine receptor 1 (RYR 1), carnitine palmitoyltransferase II (CPT II), very long-chain acyl-CoA dehydrogenase (VLCAD), and cytochrome P450 (CYP) 2D6 genes. Different RYR1 mutations that caused amino acid substitutions ((612)Ala>Thr and (4295)Ala>Val) were identified in 2 cases. In the CPT II gene, there was a new mutation ((545)Glu>Ala) in 1 case and there were mutations that did not change activity in 17 cases. In the VLCAD gene, there were mutations that did not change activity in 6 cases. In the CYP2D6 gene, homozygosity for CYP2D6∗10, which is associated with significantly reduced metabolic activity, was found in 3 cases, while 2 cases carried a different previously unreported missense mutation ((344)Arg>Gln and (48)His>Tyr). RYR1 mutations and the new CPT II mutation identified in this study were not observed in a control group. Eighteen cases that were genetically analyzed were also investigated immunohistochemically to diagnose the possibility of rhabdomyolysis. However, there were no significant mutations that reduced enzyme activity in the suspected cases of rhabdomyolysis. These data suggested no obvious relationship between the genetic mutations observed in this study and rhabdomyolysis., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

To diagnose the cause of death in autopsy cases, systematic examinations, such as macroscopic, pathological, biochemical, and toxicological are important. In this case report, drug examinations also gave very useful information to diagnose the cause of death, fatal diabetic ketoacidosis (DKA). A female methamphetamine abuser in her forties was found dead lying on a hotel bed. Diagnosing her cause of death was difficult only from the macroscopic findings because there was no fatal and/or serious injury or disease. On toxicological examination, acetone was detected at a high concentration (682 microg/mL in blood, 887 microg/mL in urine) using gas chromatography (GC). Using gas chromatography-mass spectrometry (GC-MS), methamphetamine was detected in the blood, urine, hair, and visceral organs; however, these concentrations were low. At the same time, GC-MS examination revealed a high glucose peak. From the results of the biochemical examination of urine, acetoacetic acid was 1940 micromol/L, beta-hydroxybutyric acid was 14,720 micromol/L, and glucose was 4620 mg/dL. Histologically, Langerhans' islets in the pancreas were fibrotic and atrophic, and no insulin-immunoreactive cells were observed. The subsequent police investigation also revealed that she had contracted diabetes mellitus type 1; therefore, we concluded that her cause of death was DKA, due to a lack of insulin injection., (Copyright 2010 Elsevier Ireland Ltd. All rights reserved.)

Dopamine D2 receptor/ankyrin repeat and kinase domain containing 1 ( DRD2/ANKK1 ) gene polymorphisms have been associated with responses to psychotropic drugs and addiction. We analyzed two DRD2/ANKK1 polymorphisms, Taq1A and –141C Ins/Del, in 37 fatal methamphetamine (MA) intoxication cases and 235 control cases in which MA and psychotropic drugs were not detected. The association among polymorphism, cause of death, and cerebrospinal fluid (CSF) dopamine concentration was evaluated. The Taq1A polymorphism distribution in the fatal MA intoxication cases differed from in the controls ( P  = 0.030) with a significantly high A1/A1 + A1/A2 genotype frequency. No significant associations were observed between –141C Ins/Del polymorphisms and MA intoxication cases or between DRD2/ANKK1 polymorphisms and CSF dopamine concentrations. Our findings suggest that the DRD2/ANKK1 Taq1A polymorphism is associated with susceptibility to fatal MA intoxication. [ABSTRACT FROM AUTHOR]

Forensic laboratories are often faced with cases in which methamphetamine hydrochloride-mixed blood is unable to be identified as human blood by immunochromatography against human hemoglobin A0. The application of mRNA expression analysis to samples that showed a false-negative with immunochromatography was investigated as an alternative approach that did not depend on the antigen-antibody reaction. Real-time PCR was used to examine the expression levels of blood markers such as glycophorin A, spectrin beta, and hemoglobin beta. Hemoglobin beta was the only marker that was specifically detected in blood, while glycophorin A was useful for determining human specificity. Hemoglobin beta showed good detection sensitivity and was detectable in 37-year-old blood stains. Hemoglobin beta was exclusively detectable in methamphetamine hydrochloride-mixed blood stains. Detergents and disinfectants did not significantly influence mRNA markers. The proposed mRNA expression analysis was suitable for human blood identification as an alternative method to immunochromatography. [ABSTRACT FROM AUTHOR]

Methamphetamine (MA) is an illicit psychostimulant that stimulates the release of catecholamines from sympathetic nerve terminals and is widely abused worldwide. Since catechol-O-methyltransferase (COMT) metabolizes catecholamines and mediates adrenergic, noradrenergic, and dopaminergic signaling responses, we investigated the effects of the COMT polymorphisms rs4633 and rs4680 on cerebrospinal fluid (CSF) catecholamine concentrations in autopsies of subjects who died of drug intoxication. 28 MA abusers and 22 fatal psychotropic drug intoxication cases were evaluated. No correlations were identified between rs4633 or rs4680 polymorphisms and CSF concentrations of adrenaline (Adr), noradrenaline (Nad), or dopamine (DA) in fatal psychotropic cases. However, among MA abusers, DA concentrations in the CSF were significantly higher in those with the T allele (CT and TT) of rs4633 than in CC genotype carriers (p=0.004). Moreover, among MA abusers, DA concentrations were significantly higher in those with the A allele (GA and AA) of rs4680 than in GG genotype carriers (p=0.017). In subsequent haplotype analyses of MA abusers, a strong correlation was identified between two COMT haplotypes and CSF DA concentrations (p=0.002). However, the CSF concentrations of Adr and Nad were not associated with COMT genotypes or haplotypes. The present results indicate that rs4633 and rs4680 polymorphisms influence CSF DA concentrations and MA toxicity in MA abusers. [ABSTRACT FROM AUTHOR]