The comprehensive in vitro proarrhythmia assay (CiPA) initiative, led by the U.S. Food and Drug Administration (FDA), provides a framework for predicting drug-induced arrhythmia risk. To support domestic CiPA implementation, we evaluated the proarrhythmic risk of sildenafil, a phosphodiesterase type 5 (PDE5) inhibitor. Sildenafil has been misused recreationally, with reports of highdose non-medical intake. To simulate misuse, in vitro assays were conducted using concentrations up to 100× the maximum therapeutic plasma concentration (Cmax). The assessment followed the three core components of the CiPA paradigm. Patch clamp assays were conducted in Human Embryonic Kidney 293 (HEK293) and Chinese hamster ovary (CHO) cells transiently expressing Nav1.5, Cav1.2, and hERG ion channels. In silico modeling was performed using the CiPAORdv1.0 model based on IC₅₀ and Hill coefficient values. Functional evaluation included multi-electrode array (MEA) recordings in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), and in vivo electrocardiography (ECG) analysis in rats was performed to observe QT interval prolongation. Sildenafil significantly inhibited hERG currents by 40.5% at 100× Cmax. In silico modeling predicted a low Torsades de Pointes (TdP) risk based on qNet biomarkers. In contrast, MEA recordings showed a concentration-dependent prolongation of corrected field potential duration (FPDc), with a significant 13.3% increase at 100× Cmax. The TdP risk estimated from MEA modeling was 64%. In vivo ECG analysis revealed significant QT prolongation at 50× Cmax. Despite low in silico TdP predictions, functional assays suggest that high concentrations of sildenafil as in misuse may pose a clinically relevant risk of QT prolongation and arrhythmia.

The Second Meeting of the National Control Laboratories for Vaccines and Biologicals in the Western Pacific, was jointly organized by the National Institute of Food and Drug Safety Evaluation of the Ministry of Food and Drug Safety in the Republic of Korea, and by the World Health Organization Regional Office for the Western Pacific. In the National Lot Release Systems session countries including Canada, China, Japan, Malaysia, Vietnam, and the Republic of Korea, all shared information on their current Lot Release Systems, including current practices and developments in risk-based official lot release of vaccines. In the session on Quality Control of Blood Products, experts from the National Institute for Biological Standards and Control shared quality control and research results for; blood coagulation factor VIII products, and the measurement of procoagulant activity in immunoglobulin products. Representatives from Japan proposed a regional collaborative study to test aggregated immunoglobulin free from complement activity. A cell-based Japanese encephalitis vaccine potency assay was proposed by representatives from Korea and they also called for voluntary participation of other National Control Laboratories in a collaborative study, on the first Korean Gloydius anti-venom standard. Participants agreed in general to continue communicating, and coordinate presentation of the study results.
Blood Coagulation Factors ; Canada ; China ; Complement System Proteins ; Encephalitis, Japanese ; Factor VIII ; Immunoglobulins ; Japan ; Korea ; Malaysia ; Quality Control ; Republic of Korea ; Vaccine Potency ; Vaccines* ; Vietnam ; World Health Organization

Synthetic cannabinoids are one of most abused new psychoactive substances. The recreational use of abused drug has aroused serious concerns about the consequences of these drugs on infection. However, the effects of synthetic cannabinoid on resistance to tetanus toxin are not fully understood yet. In the present study, we aimed to determine if the administration of synthetic cannabinoids increase the susceptibility to tetanus toxin-induced motor behavioral deficit and functional changes in cerebellar neurons in mice. Furthermore, we measured T lymphocytes marker levels, such as CD8 and CD4 which against tetanus toxin. JWH-210 administration decreased expression levels of T cell activators including cluster of differentiation (CD) 3ε, CD3γ, CD74p31, and CD74p41. In addition, we demonstrated that JWH-210 induced motor impairment and decrement of vesicle-associated membrane proteins 2 levels in the cerebellum of mice treated with tetanus toxin. Furthermore, cerebellar glutamatergic neuronal homeostasis was hampered by JWH-210 administration, as evidenced by increased glutamate concentration levels in the cerebellum. These results suggest that JWH-210 may increase the vulnerability to tetanus toxin via the regulation of immune function.
Animals ; Cannabinoids ; Cerebellar Diseases* ; Cerebellum ; Glutamic Acid ; Homeostasis ; Immunosuppression* ; Mice* ; Neurons ; R-SNARE Proteins ; T-Lymphocytes ; Tetanus ; Tetanus Toxin

The first meeting of the National Control Laboratories for Vaccines and Biologicals in the Western Pacific Region was held on September 1–2, 2016 in Seoul, the Republic of Korea. The meeting objectives were to share results of current research and to promote collaboration between the National Control Laboratories. To this end, we first discussed each country’s current status of research on quality control of biologicals. Next, we reviewed quality control of snake venom and antivenom production and the progress of a collaborative study on the Korean reference standard candidate for snake venom. We also discussed the establishment of the second regional reference standard antivenom and the characterization of the Vero cell genome landscape and its application to quality control. Moreover, we also reflected on the importance of collaboration among interested parties participating in this meeting. In conclusion, the meeting initiated networking between the national control laboratories in the Western Pacific region and paved the way to continue collaboration, which will eventually improve the region’s capacity for quality control of biologicals.
Cooperative Behavior ; Genome ; Quality Control ; Republic of Korea ; Seoul ; Snake Venoms ; Vaccines* ; Vero Cells