Although methamphetamine remains a problem, new psychoactive substances (NPS) have become an emerging issue in both Taiwan and South Korea, though their patterns differ. Taiwan seizes much larger quantities of NPS, particularly ketamine, despite having far fewer controlled NPS items than Korea. These differences suggest the NPS come from different sources. Factors beyond geographical proximity, including drug policy and drug availability and accessibility, help explain the current status of illegal drug use in the two countries.
Antibodies that detect MDMA (ecstasy) often also recognize its chemical analogue methamphetamine (METH), but two antibodies, 1bB11 and 1bF12, were identified that bind MDMA specifically without binding METH. The crystal structure of 1bB11 bound to MDMA, solved at 3.2 Å resolution, shows that key interactions involve the epoxide moiety of MDMA with residues S34 and Y36 of the antibody's light chain, and an additional interaction with E33 of the heavy chain. Mutagenesis confirmed these residues are important for binding. Comparing this structure to another antibody that binds both drugs revealed opposite binding orientations, providing a structural basis for developing a highly specific antibody for MDMA diagnosis.