GMP-compliant radiosynthesis of [18F]altanserin and human plasma metabolite studies

[(18)F]altanserin is the preferred radiotracer for in-vivo labeling of serotonin 2A receptors by positron emission tomography (PET). We report a modified synthesis procedure suited for reliable production of multi-GBq amounts of [(18)F]altanserin useful for application in humans. We introduced thermal heating for drying of [(18)F]fluoride as well as for the reaction instead of microwave heating. We furthermore describe solid phase extraction and HPLC procedures for quantitative determination of [(18)F]altanserin and metabolites in plasma. The time course of arterial plasma activity with and without metabolite correction was determined. 90 min after bolus injection, 38.4% of total plasma activity derived from unchanged [(18)F]altanserin. Statistical comparison of kinetic profiles of [(18)F]altanserin metabolism in plasma samples collected in the course of two ongoing studies employing placebo, the serotonin releaser dexfenfluramine and the hallucinogen psilocybin, revealed the same tracer metabolism. We conclude that metabolite analysis for correction of individual plasma input functions used in tracer modeling is not necessary for [(18)F]altanserin studies involving psilocybin or dexfenfluramine treatment

Modern trends of the development of excursion tourism in Belarus

экскурсионный туризм, экскурсионные маршруты, туристская индустрия, инновации в экскурсионном туризме = excursion tourism, excursion routes, tourism industry, innovations in excursion tourism.Статья посвящена анализу современного состояния и особенностей развития экскурсионного туризма в Беларуси. Выявлены основные тенденции развития и инновационной деятельности в сфере экскурсионного туризма.The article is devoted to the analysis of the current state and the most important features in the development of the excursion tourism in Belarus. The basic trends and areas of innovation in the field of excursion tourism were identified

Acute Effects of Lysergic Acid Diethylamide in Healthy Subjects.

BACKGROUND: After no research in humans for >40 years, there is renewed interest in using lysergic acid diethylamide (LSD) in clinical psychiatric research and practice. There are no modern studies on the subjective and autonomic effects of LSD, and its endocrine effects are unknown. In animals, LSD disrupts prepulse inhibition (PPI) of the acoustic startle response, and patients with schizophrenia exhibit similar impairments in PPI. However, no data are available on the effects of LSD on PPI in humans. METHODS: In a double-blind, randomized, placebo-controlled, crossover study, LSD (200 μg) and placebo were administered to 16 healthy subjects (8 women, 8 men). Outcome measures included psychometric scales; investigator ratings; PPI of the acoustic startle response; and autonomic, endocrine, and adverse effects. RESULTS: Administration of LSD to healthy subjects produced pronounced alterations in waking consciousness that lasted 12 hours. The predominant effects induced by LSD included visual hallucinations, audiovisual synesthesia, and positively experienced derealization and depersonalization phenomena. Subjective well-being, happiness, closeness to others, openness, and trust were increased by LSD. Compared with placebo, LSD decreased PPI. LSD significantly increased blood pressure, heart rate, body temperature, pupil size, plasma cortisol, prolactin, oxytocin, and epinephrine. Adverse effects produced by LSD completely subsided within 72 hours. No severe acute adverse effects were observed. CONCLUSIONS: In addition to marked hallucinogenic effects, LSD exerts methylenedioxymethamphetamine-like empathogenic mood effects that may be useful in psychotherapy. LSD altered sensorimotor gating in a human model of psychosis, supporting the use of LSD in translational psychiatric research. In a controlled clinical setting, LSD can be used safely, but it produces significant sympathomimetic stimulation