Opioid use disorder is a major global-scale social issue affecting public health. Opioid use is a major concern due to its high potential for addiction and dependence, contributing to substancerelated disorders. Genetic and environmental factors contribute to the predisposition to opioid use disorders (OUD). The opioidergic, dopaminergic, and GABAergic systems are the primary systems involved in the onset of OUD. Consequently, this narrative review aims to document the association between the genes and their variants identified through the studies related to these key systems, along with current epigenetic interventions in OUD. Genetic associations play a prominent role in OUD, with single-nucleotide variants identified in OUD-affected populations. Previous research indicates that the OPRM1, OPRD1, OPRK1, PDYN, OPRL1 and POMC genes from the opioidergic system; the DRD1, DRD2, DRD3, DRD4, ANKK1 and COMT genes from the dopaminergic system, and the GABRA2, GABRB3, GABRG2, GAD1 and GAD2 genes from the GABAergic system are associated with the phenotypes of OUD in different ethnicities. In addition, the accumulated evidence suggests that chronic opioid use is associated with epigenetic changes in the DNA through post-translational histone modifications and DNA methylation processes. Although many candidate-gene associations have been proposed for OUD, a considerable number of studies have small sample sizes,

Background: Haemolysis – one of the major limiting factors of red cell concentrate quality – must be measured as a quality-monitoring requirement. According to international quality standards, percentage haemolysis must be monitored in 1.0% of red cell concentrates produced monthly and maintained under 0.8%.Objective: This study assessed three alternative methods for determining plasma haemoglobin concentration in peripheral blood banks that lack a plasma or low haemoglobin photometer – the gold-standard method – in Sri Lanka.Methods: A standard haemolysate was prepared using an unexpired whole blood pack of normal haemoglobin concentration. A concentration series from 0.1 g/dL to 1.0 g/dL was prepared by diluting portions of standard haemolysate with saline. The alternative methods, namely visual haemoglobin colour scale, spectrophotometric calibration graph, and standard haemolysate capillary tube comparison, were designed using this concentration series and were used to test red cell concentrates received at the Quality Control Department of the National Blood Center, Sri Lanka, from February 2021 to May 2021.Results: A strong correlation was observed between the haemoglobin photometer method and the alternative methods (R = ~0.9). Based on the linear regression model, the standard haemolysate capillary tube comparison method was the best of the three alternative methods (R2 = 0.974).Conclusion: All three alternative methods are recommended for use in peripheral blood banks. The standard haemolysate capillary tube comparison method was the best model.

Methamphetamine is a highly addictive stimulant with severe health and psychosocial consequences. Over recent decades, genetic and molecular research on methamphetamine use disorders has expanded considerably, yet a comprehensive synthesis of this growing body of literature is lacking. This study conducted a bibliometric analysis to map the scientific landscape of genetic and molecular biology research on methamphetamine use, identifying key contributors, influential publications, publication trends, and co-occurring keywords and citations. A systematic search of the Scopus database retrieved 1550 documents. After applying the inclusion criteria and manual screening, 449 peer-reviewed articles published between 1993 and 2025 were included. Performance analysis and scientific mapping were conducted using VOSviewer software through bibliographic coupling and keyword co-occurrence. The study followed the BIBLIO checklist for reporting bibliometric reviews in biomedical literature. Publication output increased markedly after 2005, peaking in 2022, followed by a decline that may reflect a shift in research priorities. The United States, China, and Japan emerged as leading contributors, underscoring their significant investment in addiction and molecular research. Keyword co-occurrence revealed strong emphasis on addiction, dopamine, neurotoxicity, gene expression, and genetic polymorphisms, highlighting their central role in the pathophysiology of methamphetamine use disorders. This bibliometric analysis demonstrates substantial growth and influence of genetic research on methamphetamine use. Despite a recent decline in publications, the field provides a solid foundation for future interdisciplinary research and funding priorities in addiction genetics.