Development of a LC-MS/MS method for determination of propofol-glucuronide in hair and preliminary study on relationships between dose and hair concentration.

Propofol abuse has been reported worldwide, suggesting the need to establish analytical methods for human biological samples to investigate the abuse of propofol. This study aimed to investigate the relationship between dose and hair concentration using a simple and rapid analytical method developed and validated in this study. In the sample preparation, hair samples were washed with distilled water and methanol and extracted in methanol during 16h at room temperature. After centrifugation and evaporation, the residue was reconstituted and filtered through a 0.22µm membrane filter before LC-MS/MS analysis. The precursor-to-product ion transitions were 353 → 175, 113 for propofol glucuronide and m/z 370 → 175, 113 for internal standard(propofol glucuronide-d17). The calibration curves were satisfactory (R2=0.9997) and the limits of detection and quantification were 2 and 5pg/mg, respectively. In addition, this study collected the history of propofol use from subjects using a questionnaire and analyzed subjects' hair samples using a validated analytical method. As a result, the concentrations of propofol glucuronide ranged from 7 to 122pg/mg (mean : 51pg/mg). There were cases of positive relationships, but generally there was no correlation between dose and hair concentration.

Web-based Korean maximum residue limit evaluation tools: an applied example of maximum residue limit evaluation for trichlorfon in fishery products.

To ensure public safety against veterinary drug residues in food products from animal sources, maximum residue limits (MRLs) should be established by scientific evidence and a transparent estimation process. The Joint Food and Agriculture Organization (FAO)/World Health Organization (WHO) Expert Committee on Food Additives (JECFA) developed an Excel workbook-based tool for MRLs evaluation in 2003. In this study, we developed a web-based tool for MRL evaluation, called Korean MRL evaluation tools (KMET). While KMET used algorithms of JECFA workbook, it added some databases (e.g., Korean food consumption database) and provided additional functions (e.g., selection of target marker residue). Web-based KMET enabled regulatory policy makers to update the database. All input data and output results related to MRL evaluation based on residue depletion and food consumption datasets were archived and provided overall processes from the initial depletion data entry to MRL establishment with user-friendly interface. Our results demonstrated the stepwise processes whereby MRL for trichlorfon in the muscle of Paralichthys olivaceus was established with functional descriptions of KMET. MRL for trichlorfon derived from KMET was proposed and notified by the Ministry of Food and Drug Safety in 2018.

A review on the abuse of three NPS (synthetic cannabinoids, kratom, poppers) among youths in Asia.

Abuse of new psychoactive substances (NPSs) among youths is increasing at an unprecedented rate all over the world. In Asia, abuse of synthetic cannabinoids (SCs), kratom, and poppers has been reported, but up to date information related to abuse of these three NPSs is lacking. This literature review focuses on the recent abuse of these three NPS among Asian youth. Many studies have been conducted to investigate the abuse statuses of SCs in Asian youth in Turkey, Japan, and Korea, and many cases of kratom abuse have been reported in Malaysia and Thailand. In addition, concerns have been expressed about the use of kratom in combination with other substances by teenagers. Popper abuse has been reported among many young people in Asia, including Korea and China, and many studies on popper abuse have focused on men who have sex with men in China and Malaysia. Since NPS abuse can have severe adverse effects and create social problems, there is a continuing need to investigate NPS abuse status continuously among young people.

Development of nutritional risk assessment platform in Korea.

Risk assessment has been used to prevent health problems associated with eating habits in response to increased interest in a balanced diet. For nutritional risk assessment (NRA), it is important to 1) consider personal nutrition status based on year-round dietary intake, 2) organize core datasets such as food composition, intake, and health based guidance value (HBGV) datasets with public confidence, and 3) assess and predict the effects by using the computerized NRA tool. Our research staff constructed an integrated database system by compiling and organizing core datasets produced sporadically by different organizations and with different formats and developed a nutritional exposure and risk assessment system called Nutri-Risk (NUTRItional RISK assessment platform), which contained the database. Nutri-Risk is not only capable of NRA, but also contains additional data service functions. Here, the compilations and organization of an integrated database are outlined. In addition, the overall architectures of Nutri-Risk and dietary modeling are described and predictive simulation functions to support the regulatory decisions related to nutritional fortification or reduction policy were demonstrated.

A commentary on the effects of methamphetamine and the status of methamphetamine abuse among youths in South Korea, Japan, and China.

Methamphetamine (MA) abuse continues in East Asia and shows an increasing trend among youths in South Korea, Japan, and China. Although the negative effects of MA abuse on youth are considered as significant problems, few studies have been conducted on the topic in these countries. This paper focuses on the effects of MA on the human body and current MA abuse among youths in South Korea, Japan, and China. To investigate the negative effects of MA on the human body, we searched the keywords "MA," "human," and "effect" for studies published from 2013 to 2017. MA activates the neurotransmitter system and the central nervous system, and when used at high dosage or for long term, MA can cause severe neurotoxicity and cardiovascular problems. Online networks contribute to MA abuse by sharing methods for preparing synthetic MA. Despite efforts to reduce MA abuse, social crimes associated with its abuse continue and numbers of illegal MA users are increasing steadily in Korea, Japan, and China. In young users, diverse factors associated with drug addiction, such as curiosity and peer effect, lead to MA abuse and its attendant personal and social problems.

Illegal use patterns, side effects, and analytical methods of ketamine.

In Asian countries, such as China, Taiwan, and Hong Kong, ketamine (KT) is one of the most prevalent illicit use drugs. KT is regulated by various drug-related laws in many countries, such as Korea, Taiwan, China, U.S.A, Netherlands, UK, Australia, Mexico, and Canada. This review research explored pharmacology and side effects of KT, the illicit use patterns of KT, the analytical methods of KT in biological samples, and the concentrations of KT from abusers and non-abusers. Many side effects of KT have been reported mental and physical problems. Although many studies conducted various analytical methods for KT, this research focused on the urine and hair analysis and compared some parameters of samples, instruments, columns, extraction methods, internal standards, LOD/LOQ levels, metabolites, NK/K ratio, cut off values, and m/z values. Our research also compared the concentrations of KT in biological samples from abusers and non-abusers. Many rapid and precise analytical methods for illegal KT use are needed to be developed and applied to real samples. To minimize and prevent harm from KT, the authorities and appropriate agencies require a careful assessment, evaluation, early identification, and surveillance of KT users in both clinical and social settings. In addition, there is a need to construct a stricter legislative management and provide preventive education to younger individuals because illegal KT use is relatively common among the young populations.