Toxicokinetics of tetrabromoethylcyclohexane (TBECH) in juvenile brown trout (Salmo trutta) and effects on plasma sex hormones

Technical 1,2-dibromo-4-(1,2 dibromoethyl)cyclohexane or tetrabromoethylcyclohexane (TBECH) used primarily as an additive flame retardant in polystyrene foams, contains two diastereoisomers, α- and β- present in equimolar amounts. At temperatures in excess of 125 °C, isomerization to two other isoforms, δ- and γ- is possible. The recent detection of TBECH in the environment and studies suggesting that isomers are androgenic prompted us to examine the toxicokinetics and biochemical effects of one of the isomers, β-, in a controlled laboratory environment. Juvenile brown trout (Salmo trutta) were exposed to three different amounts of the β-isomer (low, medium and high) via the food followed by a period in which they were exposed to unfortified food. A fourth group of fish was exposed to unfortified food for the duration of the experiment. On days 0, 7, 14, 21, 35, 49, 56, 63, 77, 91, 105, and 133, eight fish from each treatment group were euthanized and liver, plasma, lower jaw (i.e., thyroid tissue) and gonad were collected and the remaining tissue (‘whole-fish’) was retained. β-Isomer content was measured in whole-fish and in liver while estradiol (E2), 11-ketotestosterone (11-KT) and testosterone (T) were measured in plasma. Based on liver and gonad somatic indices, no apparent effects on liver or gonad development in fish from any of the treatment groups were observed. The bioaccumulation of β-isomer was similar in fish from all treatment groups with steady-state occurring before the end of the uptake phase. Depuration of the β-isomer from fish obeyed first order kinetics and there were no statistically significant differences in the depuration half life (t_1/2) among the treatment groups: 22.5 ± 10.4 (low), 13.5 ± 5.9 (med) and 13.8 ± 2.2 (high) days. Steady-state biomagnification factors were much smaller than 1 for fish in all treatment groups. Debrominated metabolites were not detected in composite liver or whole-fish extracts and there was no evidence of isomerization of the β-isomer to other isoforms in vivo. While there were occasional differences among treatment groups in circulating plasma E2, T and 11-KT levels there was no clear, temporal trend or dose-response.     

Studies for the application of boron neutron capture therapy to the treatment of differentiated thyroid cancer

The aim of these studies was to evaluate the possibility of treating differentiated thyroid cancer by BNCT. These carcinomas are well controlled with surgery followed by therapy with ¹³¹I; however, some patients do not respond to this treatment. BPA uptake was analyzed both in vitro and in nude mice implanted with cell lines of differentiated thyroid carcinoma. The boron intracellular concentration in the different cell lines and the biodistribution studies showed the selectivity of the BPA uptake by this kind of tumor.     

The uptake of PLGA micro or nanoparticles by macrophages provokes distinct in vitro inflammatory response

Biodegradable micro/nanoparticles generated from PLGA have recently attracted attention due to their clinically proven biocompatibility, especially for immunization purposes. These polymeric particulate delivery systems are able to present antigens and activate both humoral and cellular responses. Many studies have discussed the ideal size of these particles in contributing to the generation of the different types of immune response. However, these studies do not demonstrate the effect of micro or nanoparticles, without any encapsulated bioactive, on phagocytic cells after the uptake process. In this context, the aim of this study was to analyze the in vitro inflammatory behavior of J774 murine macrophages after particles' uptake, since nano/microparticles per se can differently activate phagocytic cells, using or not appropriate receptors, inducing distinct inflammatory responses. An o/w emulsion solvent extraction–evaporation method was chosen to prepare the particles. We determined their diameters, zeta potential and morphology. Fluorescent particles' uptake by J774 murine “macrophage-like” cells was also analyzed. To evaluate the in vitro inflammatory profile of these cells after micro or nanoparticles' uptake, we conducted NF-κB translocation assay by confocal microscopy and also determined the pro-inflammatory cytokines production provoked by the particles.     

人结肠癌Caco-2细胞对自组装海藻酸钠纳米粒摄取的体外研究

目的:研究人结肠癌Caco-2细胞对异硫氰基荧光素(FITC)标记的自组装海藻酸钠纳米粒(sSAN-FITC)的摄取及影响因素。方法:Caco-2细胞加入sSAN-FITC孵育后采用荧光显微镜检测细胞对sSAN-FITC的摄取情况;通过采用荧光酶标仪检测细胞内FITC的荧光强度,观察sSAN浓度、作用时间、环境pH值对细胞摄入sSAN的影响,并与空白对照组比较。结果:sSAN可以被Caco-2细胞摄入;与空白对照组比较,3种影响因素中,随着sSAN浓度升高及作用时间延长,荧光强度增强(P<0.01),当pH值低于或高于7.0时,荧光强度均增强(P<0.01或P<0.05)。结论:sSAN可被Caco-2细胞摄取,且呈浓度、时间依赖性,并受pH值的影响。     

Determinants of stages of smoking uptake among secondary school students

With the uptake of cigarette smoking hypothesised to occur through a series of contemplation and action stages, we sought to investigate what factors are associated with the contemplation of smoking among secondary school students in Queensland, Australia. A series of four cross-sectional surveys were conducted among secondary schools in Queensland in 1993, 1996, 1999 and 2002. Respondents (n = 9993) were asked about the stages of smoking. Nearly half (43%) of secondary school students reported some contemplation of smoking. Increased levels of smoking contemplation were observed among females, earlier survey years, Junior level students, students with average or below average scholastic ability, those prepared to go out with a smoker, those with recent alcohol experience, those who had influenced other students to smoke or had not discouraged other students smoking. The results of this study provide further information about the factors relevant to stages of smoking uptake among secondary school students and the influence that students may have on their peers.     

Uptake of Mpox vaccination among transgender people and gay,bisexual and other men who have sex with men among sexually-transmitted infection clinic clients in Vancouver,British Columbia

ObjectivesAs the primary public health strategy for controlling the 2022 Mpox outbreak, it is critical to evaluate the impact of Mpox vaccination campaigns for transgender people and gay, bisexual and other men who have sex with men (T/GBM). We measured vaccine uptake and associated factors among T/GBM clients of an urban STI clinic in British Columbia (BC).MethodsWe conducted a cross-sectional online survey between August 8–22, 2022 of clients who had attended the STI clinic, 5–7 weeks following the first-dose Mpox vaccination campaign in BC. We drew on a systematic review of factors associated with vaccine uptake to develop survey questions, and measured vaccine uptake among vaccine-eligible T/GBM.ResultsOverall, 51% of T/GBM had received the first dose of the vaccine. The sample (331 participants) was majority White and university educated, identified as a man and gay, 10% had trans experience, and 68% met eligibility criteria for vaccination. Among vaccine-eligible participants identifying as T/GBM, 66% had been vaccinated; being unvaccinated was more common among participants identifying as bisexual or heteroflexible/mostly straight, and who spent less time with other T/GBM. Eligible yet unvaccinated participants had lower perceived susceptibility, and reported fewer cues to action (e.g., fewer saw information promoting the vaccine), and increased constraints to vaccine access; vaccine barriers related to accessing clinics and privacy were common. The majority (85%) of those eligible and unvaccinated at time of survey were willing to receive the vaccine.ConclusionIn this sample of STI clinic clients, vaccine uptake among eligible T/GBM was high in the initial weeks following a Mpox vaccination campaign. However, uptake was patterned on social gradients with lower uptake among T/GBM who may be less effectively engaged by available promotion channels. We recommend early, intentional and diverse engagement of T/GBM populations in Mpox and other targeted vaccination programs.     

EANM guidelines for PET-CT and PET-MR routine quality control

We present guidelines by the European Association of Nuclear Medicine (EANM) for routine quality control (QC) of PET-CT and PET-MR systems. These guidelines are partially based on the current EANM guidelines for routine quality control of Nuclear Medicine instrumentation but focus more on the inherent multimodal aspect of the current, state-of-the-art PET-CT and PET-MR scanners. We briefly discuss the regulatory context put forward by the International Electrotechnical Commission (IEC) and European Commission (EC) and consider relevant guidelines and recommendations by other societies and professional organizations. As such, a comprehensive overview of recommended quality control procedures is provided to ensure the optimal operational status of a PET system, integrated with either a CT or MR system. In doing so, we also discuss the rationale of the different tests, advice on the frequency of each test and present the relevant MR and CT tests for an integrated system. In addition, we recommend a scheme of preventive actions to avoid QC tests from drifting out of the predefined range of acceptable performance values such that an optimal performance of the PET system is maintained for routine clinical use.     

COVID-19 vaccine hesitancy among people living with HIV in a low-resource setting: A multi-center study of prevalence,correlates and reasons

BackgroundHesitancy to COVID-19 vaccine may worsen the burden of COVID-19 among people living with HIV (PLHIV), who are at a higher risk of COVID-19-related hospitalization and death, compared to HIV non-infected individuals. Therefore, we evaluate the predictors and reasons for COVID-19 vaccine hesitancy among unvaccinated PLHIV in six antiretroviral therapy (ART) clinics across northern Nigeria.MethodologyIn this cross-sectional study, conducted between October 2021 and February 2022 in six hospitals across two geopolitical regions of Nigeria, we utilized interviewer-administered questionnaires to assess COVID-19 vaccine hesitancy among a convenience sample of 790 eligible adult PLHIV. Hesitancy was defined as answering ‘no' or ‘maybe’ to a question asking participants their willingness to accept the COVID-19 vaccine. A multivariate logistic regression model was used to estimate the adjusted odds ratio (aOR) and 95% confidence interval (CI) of the factors associated with COVID-19 vaccine hesitancy among PLHIV.ResultsOf the total 660 unvaccinated participants included in the analysis (61.82% female, mean age [SD] of 39.76 [10.75]), 381 (57.72%) were hesitant to COVID-19 vaccine. Being 50 years and older (aOR: 0.43; 95% CI: 0.21–0.89), being unemployed (aOR: 0.57; 95% CI: 0.34–0.95), experiencing the adverse effects of ART (aOR: 0.36; 95% CI: 0.15–0.86), and perception of being at high risk of contracting COVID-19 (aOR: 0.22; 95% CI: 0.13–0.37) were associated with significantly lower odds of hesitancy. Conversely, being female (aOR: 1.64; 95% CI: 1.02–2.61) and attending ART clinics at state administrative capital cities (IIDH Kano [aOR: 2.40; 95% CI: 1.10–5.25], MMSH Kano [aOR: 5.59; 95% CI: 1.97–10.66], YSSH Damaturu [aOR: 9.88; 95% CI: 4.02–24.29] vs. GH Gashua) were associated with significantly higher odds of hesitancy. The most common reasons for hesitancy include fear of potential adverse effects, skepticism about vaccine efficacy, the rapid development of the COVID-19 vaccine, and the perceived lack of effort to develop a cure or vaccine for HIV/AIDS.ConclusionInterventions aimed at combating misperceptions and misinformation regarding the COVID-19 vaccination program may reduce the prevalence of COVID-19 vaccine hesitancy among unvaccinated PLHIV.