Reinforcing properties of fencamfamine: Involvement of dopamine and opioid receptors

Fencamfamine (FCF) is a psychostimulant classified as an indirect dopamine agonist. The conditioning place preference (CPP) paradigm was used to investigate the reinforcing properties of FCF. After initial preferences had been determined, animals were conditioned with FCF (1.75, 3.5, or 7.0 mg/kg; IP). Only at the dose of 3.5 mg/kg FCF produced a significant place preference. Pretreatment with SCH23390 (0.05 mg/kg, SC) or naloxone (1.0 mg/kg SC) 10 min before FCF (3.5 mg/kg; IP) blocked both FCF-induced hyperactivity and CPP. Pretreatment with metoclopramide (10.0 mg/kg; IP) or pimozide (1.0 mg/kg, IP), respectively, 30 min or 4 h before FCF (3.5 mg/kg; IP), which blocked the FCF-induced locomotor activity, failed to influence place conditioning produced by FCF. In conclusion, the present study suggests that dopamine D 1 and opioid receptors are related to FCF reinforcing effect, while dopamine D 2 subtype receptor was ineffective in modifying FCF-induced CPP.

Um transtorno delirante somático atípico

This paper describes the case of a 38 year-old single man with a previous history of social phobia and alcoholism, who presented an unusual pathological belief during the last 9 years. He believe that the muscles of his arms were loose, separated from the bones, and that a green fluid flowed from his shoulders, running under the skin towards his fingers, and returning to the shoulders. He also reported pain, weakness and sensations of loose and fluffy muscles, besides having visual and kinesthetic hallucinations and judgement impairment. No other psychopathological manifestations were observed. There was a worsening of the complaints and depressive symptoms with the use of pimozide and no improvement with fluoxetine, venlafaxine or risperidone. He is presently taking sulpiride. Psychopathological issues and difficulties in diagnosis and treatment are discussed.

Brachioradial pruritus - Descriptive analysis of Brazilian case series

Background The epidemiology and clinical features of brachioradial pruritus are variably described in the literature. We sought to analyze these features in a large group of Brazilian patients. Patients and Methods In a descriptive, observational study, we identified all patients with a final diagnosis of brachioradial pruritus seen over a one-year period and re-trospectively reviewed their records. The diagnosis was made after clinical-laboratory investigation had ruled out other causes of chronic pruritus. Demographic and clinical variables were collected along with pruritus characteristics, and analyzed using des-criptive statistics. Results Forty-three patients were identified; their mean age was 55.9 years, with predominance of women (81.4%) and Caucasians (86%). In 52%, the pruritus worsened with heat and sun exposure; 58.1% had intermittent complaints; the ice-pack sign was present only in 20.9%. The arms involving dermatomes C5-C6-C7-C8 (62.8%) were the most affected sites, while psychoactive drugs were the most frequently prescribed therapy. Conclusions Although uncommon, brachioradial pruritus should not be neglected in dermatological diagnosis. This case series analysis indicated that Brazilian patients from a tropical climate show characteristics similar to those described in other series from more temperate regions. © Blackwell Verlag GmbH, Berlin.

Activation of mouse sperm T-type Ca2+ channels by adhesion to the egg zona pellucida

The sperm acrosome reaction is a Ca2+-dependent exocytotic event that is triggered by adhesion to the mammalian egg’s zona pellucida. Previous studies using ion-selective fluorescent probes suggested a role of voltage-sensitive Ca2+ channels in acrosome reactions. Here, whole-cell patch clamp techniques are used to demonstrate the expression of functional T-type Ca2+ channels during mouse spermatogenesis. The germ cell T current is inhibited by antagonists of T-type channels (pimozide and amiloride) as well as by antagonists whose major site of action is the somatic cell L-type Ca2+ channel (1,4-dihydropyridines, arylalkylamines, benzothiazapines), as has also been reported for certain somatic cell T currents. In sperm, inhibition of T channels during gamete interaction inhibits zona pellucida-dependent Ca2+ elevations, as demonstrated by ion-selective fluorescent probes, and also inhibits acrosome reactions. These studies directly link sperm T-type Ca2+ channels to fertilization. In addition, the kinetics of channel inhibition by 1,4-dihydropyridines suggests a mechanism for the reported contraceptive effects of those compounds in human males.