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Vaping has become more popular and different brands and types of vaping devices have rapidly emerged. However, little is known about the potential health risks of human inhalation exposures to the volatile chemicals in the vapour, which includes both directly vaporised components of vaping liquid and their reaction products formed during vaping processes. This study investigated reaction products of two monoterpenes (α-pinene and terpinolene) that are used as flavouring agents in vaping liquids with a focus on the identification of reaction products and their formation pathways. The thermal desorption was conducted under an in situ condition that is in the range of heating coil temperature in vaping by thermally desorbing the chemicals at a temperature range of 100-300 °C. Additional clean air was introduced during the thermal desorption. 36 and 29 reaction products were identified from α-pinene and terpinolene, respectively, at a relative concentration of 0.01% and greater in the desorbed mixture. 3-Carene was the dominant reaction product of α-pinene, while reaction products of terpinolene was dominated by p-isopropenyltoluene. Several reaction pathways including ring opening, allylic oxidation, cyclo-etherification, Wagner-Meerwein rearrangement, epoxidation, cleavage and removal of partial structure, and dehydration were involved in the formation of various reaction products. These pathways and resulting relative concentrations of residual parent compound and reaction products were influenced by both temperature and amount of air present during thermal desorption. The study results demonstrate possible existence of reaction products from thermally labile chemicals like monoterpenes in vaping aerosols and can help inform policies regulating vaping devices and products to protect public health., (© 2023. Crown.)

Vaping is gaining in popularity. However, there is still much that remains unknown about the potential risk and harms of vaping. Formation of oxidative products is one of such areas that are not well understood. In this study, we used an in-situ thermal desorption GC/MS method to investigate the formation of oxidative products of several monoterpenes at or below typical vaping temperatures. Among the five tested monoterpenes, the unchanged portion of the parent compound in the vapour varied from 97 to 98% for myrcene to 11-28% for terpinolene. The majority of formed oxidative products in the vapour have a molecular weight of 134 (loss of two hydrogens), 150 (insertion of one oxygen and loss of two hydrogen atoms) or 152 (insertion of one oxygen atom). Three products, likely to be p-(1-propenyl)-toluene, β-pinone and fenchol were also observed. This is the first in-situ thermal desorption GC/MS study to investigate the possible formation of oxidative products of monoterpenes, one of the major components in vaping liquids, at temperatures that are relevant to the vaping process. Although the toxicity of inhaling these oxidative products is not clear yet, allergic and irritation reactions associated with oxidized monoterpene oils are well documented. Therefore, potential adverse effects of inhaling these oxidative products during vaping could be investigated to help support human risk assessment., (© 2022. Crown.)

Chronic infection with Hepatitis B virus (HBV) is a major risk factor for the development of advanced liver disease including fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). The relative contribution of virological factors to disease progression has not been fully defined and tools aiding the deconvolution of complex patient virus profiles is an unmet clinical need. Variable viral mutant signatures develop within individual patients due to the low-fidelity replication of the viral polymerase creating 'quasispecies' populations. Here we present the first comprehensive survey of the diversity of HBV quasispecies through ultra-deep sequencing of the complete HBV genome across two distinct European and Asian patient populations. Seroconversion to the HBV e antigen (HBeAg) represents a critical clinical waymark in infected individuals. Using a machine learning approach, a model was developed to determine the viral variants that accurately classify HBeAg status. Serial surveys of patient quasispecies populations and advanced analytics will facilitate clinical decision support for chronic HBV infection and direct therapeutic strategies through improved patient stratification.

The innate immunity gene mannose-binding lectin2 (MBL2) has played an important role in hepatitis B virus (HBV) infection, and the relationship between MBL2 variants and hepatocellular carcinoma (HCC) risk has not yet been identified. In total, 315 HCC cases and 315 healthy controls were enrolled and blood samples were acquired. High resolution melt analysis (HRM) was employed to genotype 6 polymorphisms in MBL2 gene. Increased HCC risk in carriers of LL genotype of -550 polymorphism with an adjusted OR (AOR) of 1.61 (95%CI = 1.00-2.57) was observed but no significant association detected in HL genotype. Both YX and XX genotype demonstrated a significantly elevated HCC risk in the analysis of -221 polymorphism. The B variants in codon 54 was also significantly associated with elevated HCC risk. HYB was identified as the protective factor of HCC while LXB was significantly associated with increase HCC risk. ELISA technique revealed that the MBL2 protein was significantly reduced in HCC cases. Moreover, both IL-1β and IL-6 were inversely associated with plasma MBL2 level.The mutations in MBL2 could lead to compromised innate immunity, and possibly lead to elevated HCC risk, and a novel haplotype HXB has been identified with a rate of 12.5%.