Limbic system mGluR5 availability in cocaine dependent subjects: a high-resolution PET [(11)C]ABP688 study.

Cocaine self-administration decreases type 5 metabotropic glutamate receptor (mGluR5) tissue concentrations in laboratory rats during early abstinence. These changes are thought to influence the drug's reinforcing properties and the ability of drug-related cues to induce relapse. Here, our goal was to measure brain regional mGluR5 availability in recently abstinent cocaine dependent humans. Participants meeting DSM-IV diagnostic criteria for current cocaine dependence (n=9) were recruited from the general population. mGluR5 availability (binding potential, non-displaceable; BPND) was measured with high-resolution positron emission tomography (PET HRRT) and [(11)C]ABP688. Compared to age- and sex-matched healthy controls (n=9), cocaine dependent subjects showed significantly lower BPND values in the ventral (bilateral: -28.2%, p=0.011), associative (right: -21.4%, p=0.043), and sensorimotor striatum (bilateral: -21.7%, p=0.045), amygdala (left: -26%, p=0.046) and insula (right: -23.3%, p=0.041). Among the cocaine users, receptor availabilities were related to abstinence (range: 2 to 14days). The longer the duration of abstinence, the lower the BPND values in the sensorimotor striatum (r=-0.71, p=0.034), left amygdala (r=-0.73, p=0.026) and right insula (r=-0.67, p=0.046). Compared to healthy controls, BPND values were significantly reduced in those who tested negative for cocaine on the PET test session in the ventral (p=0.018) and sensorimotor striatum (p=0.017), left amygdala (p=0.008), and right insula (p=0.029), but not in those who tested positive. Together, these results provide evidence of time-related mGluR5 alterations in striatal and limbic regions in humans during early cocaine abstinence.

E-learning course improves knowledge in tobacco dependence, electronic nicotine delivery systems and heat-not-burn products in Medical School students.

BACKGROUND: Adequate training in tobacco, nicotine dependence and treatment is lacking in Medical School education. With the rise in popularity of electronic alternatives to cigarettes, future physicians should also be provided with the more recent scientific evidence on these products during their undergraduate studies. We introduced an e-learning course for Medical School students and assessed its effec-tiveness of increasing knowledge on these topics. METHODS: We developed 16 didactic modules divided in 3 courses: tobacco dependence (TDI), treating tobacco dependence (TDII) and electronic products and tobacco control (TDIII). The course was offered to 4th, 5th, and 6th year Medical School students in Italy. To assess learning outcomes, we examined the pre- to post- changes in knowledge scores associated with each course. Paired and independent samples t-tests were performed overall, and among smokers and non-smokers separately. RESULTS: A total of 1318 students completed at least one of the courses; 21% were self-reported smokers. A significant increase in knowledge was observed at the end of TDI (pre-course: 52.1±15.9, post-course: 79.9±13.5, p<0.001), TDII (pre-course: 52.5±13.0, post-course: 66.5±12.0, p<0.001) and TDIII (pre-course: 52.2±15.3, post-course: 76.1±17.7, p<0.001). Smokers showed significantly lower improvements compared to non-smokers. CONCLUSIONS: The e-learning course was effective in increasing knowledge about tobacco dependence, treatments, and electronic ni-cotine products in advanced medical students. Given the fundamental role for healthcare practitioners in encouraging and assisting people in quitting smoking, e-learning may be a useful tool in providing up-to-date and standardized training in the area during Medical School.

Thyroid disrupting effects of low-dose dibenzothiophene and cadmium in single or concurrent exposure: New evidence from a translational zebrafish model.

Thyroid hormones (THs) are major regulators of biological processes essential for correct development and energy homeostasis. Although thyroid disruptors can deeply affect human health, the impact of exogenous chemicals and in particular mixture of chemicals on different aspects of thyroid development and metabolism is not yet fully understood. In this study we have used the highly versatile zebrafish model to assess the thyroid axis disrupting effects of cadmium (Cd) and dibenzothiophene (DBT), two environmental endocrine disruptors found to be significantly correlated in epidemiological co-exposure studies. Zebrafish embryos (5hpf) were exposed to low concentrations of Cd (from 0.05 to 2 µM) and DBT (from 0.05 to 1 µM) and to mixtures of them. A multilevel assessment of the pollutant effects has been obtained by combining in vivo morphological analyses allowed by the use of transgenic fluorescent lines with liquid chromatography mass spectrometry determination of TH levels and quantification of the expression levels of key genes involved in the Hypothalamic-Pituitary-Thyroid Axis (HPTA) and TH metabolism. Our results underscore for the first time an important synergistic toxic effect of these pollutants on embryonic development and thyroid morphology highlighting differences in the mechanisms through which they can adversely impact on multiple physiological processes of the HPTA and TH disposal influencing also heart geometry and function.