• Journal of Preventive Medicine and Public Health
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• v.51 no.1
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• pp.23-32
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• 2018

Objectives: To identify the associations of characteristics of the neighborhood environment with substance abuse among clients receiving treatment for drug abuse in Thailand. Methods: A cross-sectional study was conducted of 1128 drug addicts from 28 neighborhoods who were receiving treatment at all 7 compulsory drug detention centers in Thailand. A trained interviewer conducted structured interviews with the subjects about substance use and the perceived neighborhood environment in their community. A multilevel logistic regression model was applied to estimate the effects of the neighborhood environment on substance use. Results: The majority of participants, 53.8% only used methamphetamine pills, 31.3% used other illicit drugs as well as methamphetamine pills, and 14.9% used an illicit drug other than methamphetamine. Three neighborhood characteristics were associated with substance use. A 1-unit increase in the perceived neighborhood cohesion score was associated with a 15% reduction in methamphetamine pill use and an 11% reduction of the use of both methamphetamine pills and another illicit drug. Conversely, a 1-unit increase in perceived neighborhood crime predicted 19 and 14% increases in the use of methamphetamine pills and the use of both methamphetamine pills and another illicit drug, respectively. In addition, a 1-unit increase in the scores for stigma surrounding addiction corresponded to a 25% increase of the use of methamphetamine pills and a 12% increase in the use of both methamphetamine pills and another illicit drug. Conclusions: Substance use among drug addicts was influenced by characteristics of the neighborhood environment. Therefore, prevention and intervention strategies should be designed based on a consideration of the impact of neighborhood context on substance use behaviors.

• YAKHAK HOEJI
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• v.42 no.1
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• pp.101-107
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• 1998

The antiparkinsonian agent l-deprenyl, a selective monoamine oxidase (MAO)-B inhibitor, is metabolized in part to l-methamphetamine and l-amphetamine. l< /I>-Deprenyl was evaluated for amphetamine and methamphetamine-like discriminative stimulus effects in rats and its mechanism of action was investigated. Rats were trained under a 5-response, fixed ratio schedule of stimulus-shock termination or a 10-response. Fixed-ratio schedule of food-presentation which discriminate between d-amphetamine (1mg/kg, i.p.) and saline or d-methamphetamine (1mg/kg, i.p.) and saline in a two-lever, operant conditioning procedure. Full generalization was obtained to d-amphetamine (1~3mg/kg). d-methamphetamine (1~3mg/kg) and l-deprenyl (17~30mg/kg) under both the food presentation and stimulus shock termination schedule. l-Deprenyl has dose-dependent amphetamine-and methamphetamine-like discriminative stimulus properties in rats only at doses of 17 and 30mg/kg. Reversible MAO-B inhibitor, RO 16-6491 didn`t show any amphetamine-like discriminative properties. Aromatic amino acid decarboxylase inhibitor, NSD 1015 decreased % responding of l-deprenyl in the methamphetamine-trained rats under the stimulus-shock termination schedule. SKF-525A produced partial inhibition of methamphetamine-like discriminative effects of l-deprenyl under the food presentation schedule. These results suggest that l-deprenyl has no abuse liability at the therapeutic range but there needs some caution at high doses and furthermore, drug discrimination studies under the food presentation and shock termination schedule are useful for the assessment of abuse liability of psychostimulants.

• The Korean Journal of Pharmacology
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• v.20 no.1 s.34
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• pp.33-39
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• 1984

The present study was undertaken to elucidate the chracteristics in behavioral changes of chronic doses of methamphetamine on open-field activity in rats. On the other hand, the nucleus accumbens septi(NAB), one of the major areas containing mesolimbic dopaminergic terminals, has been considered to be an important site of action for dopaminergic agonists. Therefore, it also designed to investigated influence of NAB lesions. on behavioral effects of chronic-methamphetamine. Caudal and rostral areas of NAB(cr-NAB) were lesioned by applying DC of 3.0 mA for 15 sec., simultaneously. The results were as follows: 1) The rats exhibited hyperactivity after chronic administration of methamphetamine 2) The cr-NAB-lesioned rats showed a significant increase in locomotor activity only at 2 days after NAB lesions 3) Methamphetamine-induced hyperactivity was significantly decreased in the NAB-lesioned rats, and stereotyped behavior was induced instead by the drug. 4) Dopamine content of striatum was significantly decreased and serotonin content of olfactory bulb was significantly increased in NAB-lesioned rats. These results suggest that NAB plays an important role in locomotor activity and methamphetamine-induced hyperactivity.

• Biomolecules & Therapeutics
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• v.12 no.2
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• pp.101-107
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• 2004

Repeated administration of psychostimulants such as amphetamines increases locomotor activity in rodents. These drugs, including methamphetamine, enhance dopaminergic neurotransmission and result in hyper-locomotion and behavioral sensitization. It is well known that the existence of a complex balance between the cholinergic and dopaminergic systems in the central nervous system. Thus, behavioral sensitization by methamphetamine may be related to the expression of the M1 muscarinic acetylcholine receptors gene. The present study investigated the changes of M1R mRNA in hyperlocomotor activity and behavioral sensitization by methamphetamine (2 mg/kg) in mice. Our results showed that M1R mRNA expression was increased in the frontal cortex and the hippocampus region (the CA2 region) in the acute methamphetamine administered group compared to the saline administered group. In the chronic group, M1R mRNA expression was increased in the frontal cortex ill1d the hippocampus regions (CA2 and DG regions) in melt1amphetamine administered group compared to saline control group. These results indicate that acute or chronic treatment of mathamphetamine leads to the region-specific changes in mRNA expression levels of M1R. Therefore, Therefore, the present result suggests that M1R may play a role in modulating of methamphetamine-induced behavioral sensitization in mice.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.102-102
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• 1995

The present study was undertaken to investigate the behavioral and biochemical effects of ginseng total sponin (GTS) on methamphetamine-treated mice. GTS (50 or 100 mg/kg) was administered intraperitoneally two times with 2 hour interval. Two hours after the second injection of GTS, methamphetamine (2 mg/kg) was administered subcutaneously. The ambulatory activity of mice was measured by the ti1ting-type ambulometer every 10 min. for 1 hour. Methamphetamine-induced hyperactivity was reduced by GTS. in a dose-dependent manner. To study the neurochemical mechanism underlying the GTS effects, monoamine contents were measured from brain tissues. After 45 min. of methamphetamine injection. mice were sacrificed and monoamine contents were determined from the striatum. Biochemical analysis revealed that GTS reduced the methamphetamine- induced increase in striatal dopamine contents. These observations indicate that inhibition of methamphetamine-induced hyperactivity by GTS is mediated by the modulation of dopaminergic nervous system, and it could be helpful for the therapy of hyperactivity.

• Korean Journal of Biological Psychiatry
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• v.19 no.2
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• pp.99-105
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• 2012

Objectives : This study aims to identify temperament and characteristics of cannabis and methamphetamine abusers for elucidating psycho-biological variables related to certain substance abuse. Methods : A total of 320 patients who registered in the 'Hepatitis C cohorts study of intravenous drug users' between March 2006 and March 2010 participated in this study. Data on demographic variables were obtained and the Temperament and Character Inventory (TCI) and measures for nicotine dependence, alcohol dependence, depression and anxiety were assessed. After comparing TCI between cannabis, methamphetamine, and co-abusers, correlations between TCI and other clinical variables were examined. Results : The methamphetamine abuser group showed significantly higher scores in Novelty Seeking (NS2) and Harm Avoidance (HA3) in temperament than the cannabis abuser and co-abuser groups, whereas the cannabis abuser group had higher scores in purposefulness (SD2), congruent second nature (SD5), and self-directedness (SD) in character than the methamphetamine abuser group. In addition, temperaments and characters correlated with various psychiatric symptoms. Conclusions : We found the differences in temperament and characters among cannabis abusers, methamphetamine abusers. These findings might contribute to further understanding of mechanisms of cannabis and methamphetamine abuse.

• YAKHAK HOEJI
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• v.42 no.6
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• pp.627-633
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• 1998

Impurity profiling analysis of methamphetamine seized in Korea was investigated for the evidential and intelligent purpose. Samples were extracted with ethylacetate which contai ns internal standard of dioctylsebacate under basic condition and extracts were analyzed by GC-FID. Ephedrine, chloroephedrine & 1,2-dimethyl-3-phenylaziridine were identified impurities in illicit methamphetamine by GC-MS. These impurities revealed that most of abused methamphetamine in Korea were synthesized from ephedrine as a starting material. For the classification of samples. firstly, 24 impurity peaks were selected after inspection of every peak in 50 samples as the specific markers of impurities. Secondly, corresponding peak retention time and area ratio to the internal standard were calculated and database was created with values of 24 peaks by in-house program. Finally, cluster analysis was attempted with the resultant profiles using the STAR plot, which was based on the Euclidian distance for evaluating similarity among samples. A total of 76 samples were divided into 8 different groups within 90% statistical similarity and inter-batch samples showed similar impurity patterns by this procedure. In conclusion, the analysis of impurities is a suitable index for estimation the common or different origin of methamphetamine sample.

• Journal of The Korean Society of Clinical Toxicology
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• v.16 no.1
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• pp.25-32
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• 2018

Purpose: Methamphetamine is an ongoing illegal drug problem worldwide, and its use in South Korea has spread over the last few years. In this study, a clinical review of patients who visited emergency medical centers with positive methamphetamine tests was conducted. Methods: Patients underwent methamphetamine screening based on physician suspicion over a period of 13 years. Their patient characteristics, clinical features, and drug administration properties were described. Results: A total of 297 patients were included, with 19 positive methamphetamine results. Patient age ranged from 21 to 84, with a mean of 37.52. Additionally, 13 were male and 6 were female. The mean BP, PR, RR were 131/82 mmHg, 94/min, 20/min. Saturation levels were all over 95%. Five patients had a psychiatric history. Patient showed varied symptoms ranging from mental changes to chest discomfort. In addition, seven showed abnormal electrocardiography findings and one showed elevated cardiac enzyme levels. Other laboratory results revealed no significantly abnormal results. Six patients also suffered from related trauma. The majority of patients consumed the methamphetamine orally, with unknown motivation at unknown locations. Most were transported by 119 and six patients co-ingested other drugs. Conclusion: Patients who showed positive results to a methamphetamine screening test in Korea visited the emergency medical center mostly by 119 and were unaware of or reluctant to reveal the fact that they had ingested methamphetamine. Emergency physicians should be more aware of the possibility that a patient may have consumed methamphetamine.

• BMB Reports
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• v.40 no.4
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• pp.475-485
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• 2007

Methamphetamine is an illicit drug that is often abused and can cause neuropsychiatric and neurotoxic damage. Repeated administration of psychostimulants such as methamphetamine induces a behavioral sensitization. According to a previous study, Bax was involved in neurotoxicity by methamphetamine, but the function of Bax in rewarding effect has not yet been elucidated. Therefore, we have studied the function of Bax in a rewarding effect model. In the present study, we treated chronic methamphetamine exposure in a Bax-deficient mouse model and examined behavioral change using a conditioned place preference (CPP) test. The CPP score in Bax knockout mice was decreased compared to that of wild-type mice. Therefore, we screened for Bax-related genes that are involved in rewarding effect using microarray technology. In order to confirm microarray data, we applied the RT-PCR method to observe relative changes of Bcl2, a pro-apoptotic family gene. As a result, using our experiment microarray, we selected genes that were associated with Bax in microarray data, and eventually selected the Tgfbr2 gene. Expression of the Tgfbr2 gene was decreased by methamphetamine in Bax knockout mice, and the gene was overexpressed in Bax wild-type mice. Additionally, we confirmed that Creb, FosB, and c-Fos were related to rewarding effect and Bax using immunohistochemistry.

• Journal of The Korean Society of Clinical Toxicology
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• v.1 no.1
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• pp.21-26
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• 2003

Methamphetamine (MA) is a major drug of abuse in Korea. Currently preliminary evidence suggests that MA dependence may cause long-term neural damage in human. Repeated exposure to psychostimulants such as methamphetamine results in behavioral sensitization, a paradigm thought to be relevant to drug craving and addiction in human. Sensitization alters neural circuitry involved in normal processes of incentrive, motivation, and reward. However the precise mechanism of this behavioral sensitization has not yet been fully elucidated. Repeated use of high dose MA causes neurotoxicity which is characterized by a long-lasting depletion of striatal dopamine (DA) and tyrosin hydroxylase activity of DA, DA-transporter binding sites in the striatum. The loss of DA transporters correlates with memory problems and lack of motor coordination. DA fuels motivation and pleasure, but it' s also crucial for learning and movement. This selective review provides a summary of studies that assess the neurobiological mechanisms of MA.