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Psilocybin is a classical serotoninergic psychedelic that induces cognitive disruptions similar to psychosis. Gamma activity is affected in psychosis and is tightly related to cognitive processing. The 40 Hz auditory steady-state responses (ASSR) are frequently used as indicators to test the ability to generate gamma activity. Based on previous literature, we studied the impact of psilocybin on 40 Hz ASSR in healthy volunteers. The study was double blind and placebo controlled with a crossover design. A sample of 20 healthy subjects (10M/10F) received psilocybin orally 0.26 mg/kg or placebo. Participants were measured four times in total, one time before ingestion of psilocybin/placebo and one time after ingestion, during the peak of intoxication. A series of 500 ms click trains were used for stimulation. Psilocybin induced a psychedelic effect and decreased 40 Hz ASSR phase-locking index compared to placebo. The extent of the attenuation was related to Cognition and Affect on the Hallucinogen Rating Scale. The current study shows that psilocybin lowers the synchronization level and the amplitude of 40 Hz auditory steady-state responses, which yields further support for the role of gamma oscillations in cognitive processing and its disturbance.

Serotonergic agonist psilocybin is a psychedelic with antidepressant potential. Sleep may interact with psilocybin's antidepressant properties like other antidepressant drugs via induction of neuroplasticity. The main aim of the study was to evaluate the effect of psilocybin on sleep architecture on the night after psilocybin administration. Regarding the potential antidepressant properties, we hypothesized that psilocybin, similar to other classical antidepressants, would reduce rapid eye movement (REM) sleep and prolong REM sleep latency. Moreover, we also hypothesized that psilocybin would promote slow-wave activity (SWA) expression in the first sleep cycle, a marker of sleep-related neuroplasticity. Twenty healthy volunteers (10 women, age 28-53) underwent two drug administration sessions, psilocybin or placebo, in a randomized, double-blinded design. Changes in sleep macrostructure, SWA during the first sleep cycle, whole night EEG spectral power across frequencies in non-rapid eye movement (NREM) and REM sleep, and changes in subjective sleep measures were analyzed. The results revealed prolonged REM sleep latency after psilocybin administration and a trend toward a decrease in overall REM sleep duration. No changes in NREM sleep were observed. Psilocybin did not affect EEG power spectra in NREM or REM sleep when examined across the whole night. However, psilocybin suppressed SWA in the first sleep cycle. No evidence was found for sleep-related neuroplasticity, however, a different dosage, timing, effect on homeostatic regulation of sleep, or other mechanisms related to antidepressant effects may play a role. Overall, this study suggests that potential antidepressant properties of psilocybin might be related to changes in sleep., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 Dudysová, Janků, Šmotek, Saifutdinova, Kopřivová, Bušková, Mander, Brunovský, Zach, Korčák, Andrashko, Viktorinová, Tylš Bravermanová, Froese, Páleníček and Horáček.)

Rationale: Disruption of auditory event-related evoked potentials (ERPs) P300 and mismatch negativity (MMN), electrophysiological markers of attentive and pre-attentive cognitive processing, is repeatedly described in psychosis and schizophrenia. Similar findings were observed in a glutamatergic model of psychosis, but the role of serotonergic 5-HT 2A receptors in information processing is less clear., Objectives: We studied ERPs in a serotonergic model of psychosis, induced by psilocybin, a psychedelic with 5-HT 2A/C agonistic properties, in healthy volunteers., Methods: Twenty subjects (10M/10F) were given 0.26 mg/kg of psilocybin orally in a placebo-controlled, double-blind, cross-over design. ERPs (P300, MMN) were registered during the peak of intoxication. Correlations between measured electrophysiological variables and psilocin serum levels and neuropsychological effects were also analyzed., Results: Psilocybin induced robust psychedelic effects and psychotic-like symptoms, decreased P300 amplitude (p = 0.009) but did not affect the MMN. Psilocybin's disruptive effect on P300 correlated with the intensity of the psychedelic state, which was dependent on the psilocin serum levels. We also observed a decrease in N100 amplitude (p = 0.039) in the P300 paradigm and a negative correlation between P300 and MMN amplitude (p = 0.014)., Conclusions: Even though pre-attentive cognition (MMN) was not affected, processing at the early perceptual level (N100) and in higher-order cognition (P300) was significantly disrupted by psilocybin. Our results have implications for the role of 5-HT 2A receptors in altered information processing in psychosis and schizophrenia.

Cannabis consumption has individual influence to cognitive and psychomotor functions of drivers and it has been generally accepted that driving under influence is risky in the perspective of traffic safety. However, rules how to assess fitness to drive are not quite clear. The psychoactive compound delta-9-tetrahydrocannabinol (THC) impairs cognition, psychomotor behaviour and driving performance in a dose-related manner approximately. After a single drug dose, THC blood concentration peaks within minutes, before the end of smoking, with a subsequent rapid decrease to the analytical limit of detection. Peak euphoria is delayed compared to THC peak blood concentration and physiological and behavioural effects return to baseline within 3-5 hours. In chronic users, the lipophilic THC accumulates in fat tissues, where its slow redistribution into blood is the rate limiting process in its terminal elimination. In our experimental study we have attempted to contribute to this discussion with results obtained from human volunteers - cannabis consumers in Czech Republic. Aim of our study was to document the time profile of serum THC level in occasional and chronic cannabis users. The observational interval covered the time immediately after the drug consumption (an own cigarette/joint) till 24 hours after. Our preliminary results have shown that in occasional users, THC serum levels cannot be detected already 4 hours after usual cannabis dose, whereas in chronic users measurable THC concentrations in serum persist longer. Moreover, some chronic consumers were practically with permanent THC detection during our observation period and also the chronic users consumed higher THC doses significantly related to doses in occasional ones. Presented results of the experimental study with human volunteers confirm a great individual variability of the kinetic profile of THC in blood due to complicated redistribution. The practical forensic question is how long the psychotropic effects of THC can persist after the last drug dose. In chronic users there are well documented indications of long term adverse effects to neurocognitive functions. THC blood level itself can not directly document the intensity of impairment of a driver. Moreover, the concentration of THC in blood at the time of driving is probably substantially higher than at the time of blood sampling. Therefore due to the prevention of traffic risk, some countries adopted per se traffic legislation based on analytical principle with minimum tolerance to illegal drugs in blood of drivers at driving. Low blood concentrations of THC close to the limit of detection of a specific toxicological method (GC-MS or LC-MS) are justified in an effective traffic legislation.

Mycobacterium (M.) marinum is a human opportunistic pathogen, capable of causing skin infections and possibly also affecting deeper tissues. The authors describe a case of skin infection caused by M. marinum in a female patient with an appropriate case history. They emphasize the need of close cooperation of the clinician with a microbiologist when establishing the diagnosis.

The authors present the results of the URVAKOL vaccine use in clinical practice. The vaccine was administered in the treatment of recurrent cystitis, persistent lower urinary tract infection, chronic pyelonephritis and prostatovesiculitis. The clinical efficacy of the vaccine was assessed by detection of bacteria and leukocytes in the urine, subjective complaints, skin tests and the assessment of selected specific and nonspecific immunity parameters in the urine and saliva. Significantly positive clinical and laboratory responses were observed in patients with uncomplicated cystitis. In the group of persistent urinary tract infections excellent responses were detected in one half of the patients. The remainder half stated disappearance of subjective complaints, but with persistence of pyuria or bacteriuria. Similar results of "improvement" were observed in 10 patients with chronic pyelonephritis. There were no changes of the clinical state observed in patients with chronic prostatitis. (Tab. 5, Fig. 2, Ref. 7.)

In a group of 691 patients with different dermatoses the therapeutic effect of two forms of lyophilized vaccines administered orally according to a desensitization (drops) and immunization (tablets) plan. Their effect was as a rule marked already during the third week of treatment. During the final evaluation no signs of the disease were present or great improvement was recorded in 89-100% of the patients suffering from acne, chronic staphylococcal pyoderma or microbial eczema and 62% (drops) or 65% (tablets) of patients with atopic eczema. During treatment the authors did not observe with rare exceptions of focal reactions any undesirable effects. No significant differences were found between the two forms of the drugs as regards therapeutic effects. Contrary to antibiotics, which can cause remission of dermatosis, while early relapses cannot be prevented, oral vaccine treatment leads to long-term (extending over several years) favourable effects on the course of the disease. The immunization pattern used in tablet form vaccines is simpler, packing and storage is simpler, dosage is more accurate and more convenient for the patient.