Effects of droperidol on the biosynthesis and release of endogenous opioid peptides in guinea-pig ileum

Acute administration of droperidol 2 or 5 mg kg-1 induced an increase in the inhibitory response obtained by stimulation at 10 Hz of the myenteric plexus longitudinal muscle preparation of the guinea-pig ileum. The increase in the response induced by droperidol was markedly reduced by naloxone which suggests that it is mediated by endogenous opioid release. Cycloheximide treatment significantly reduced the increase of the inhibitory response induced by droperidol, indicating that the biosynthesis and the release of endogenous opioid are increased by droperidol.

Pharmacological evidence for the existence of interactions between dopaminergic and opioid peptidergic systems in guinea-pig ileum myenteric plexus

Apomorphine or bromocriptine treatment at doses that act on dopamine autoreceptors resulted in a significant elevation of the release of opioid peptides from the myenteric plexus of guinea-pig, since these drugs produced an increase of the inhibitory response which was reversed by naloxone. 6-Hydroxydopamine treatment also resulted in an increase in opioid peptide release. These findings would indicate that the interruption of dopaminergic transmission in the myenteric plexus produces an increase in the release of opioid peptides and suggest an inhibitory modulation of opioid peptidergic neurons by dopamine systems at this level.

Opportunistic infection of the spleen caused by Aureobasidium pullulans

The mold Aureobasidium pullulans was isolated on several nutrient media from a splenic abscess in a patient with disseminated lymphoma. Examination of stained smears and paraffin sections revealed fungal structures characteristic of this organism. This is the first reported association of A. pullulans with an opportunistic visceral infection.

The effect of lactation on the fractional synthetic rate of protein in the liver and muscle of rats

Protein synthesis in muscle and liver were studied in rats in early and peak lactation. While the fractional synthetic rate of liver was greatly enhanced there were no significant changes in muscle. No evidence was obtained for a marked contribution of muscle protein for the demand of lactation.

Identification of an altered elongation factor in temperature-sensitive mutant ts 7'-14 of Saccharomyces cerevisiae

Postpolysomal extracts from wild-type (wt A364A) and temperature-sensitive (ts 7'-14) yeast cells were preincubated for short periods of time at the nonpermissive temperature (37-41 degrees C) prior to incubations for protein synthesis at 20 degrees C. Whereas wt A364A extracts were relatively unaffected by preincubation at the elevated temperature, mutant extracts lost their ability to translate exogenous natural mRNA and poly(U). Phe-tRNA synthetase and ribosomes from ts 7'-14 cells were not inactivated by preincubation at 37-41 degrees C, but a cytosolic component required for chain elongation, as measured by poly(U) translation, was extensively inactivated. The three elongation factors (EF-1, EF-2, and EF-3) required for chain elongation in yeast were resolved chromatographically. Only one factor, EF-3, was able to restore the poly(U)-translational activity of mutant extracts inactivated at the elevated temperature. Heat-inactivated yeast cytosols, which did not support protein synthesis with yeast ribosomes, were perfectly able to translate poly(U) with rat liver ribosomes, which require only EF-1 and EF-2. These and other experiments indicated that the genetically altered component in 7'-14 mutant cells is EF-3.

The mode of action of anabolic agents: the effect of testosterone on muscle protein metabolism in the female rat

Testosterone (1 mg/kg body-weight per d) given subcutaneously to female rats increased their growth rate and food conversion efficiency but not their food intake compared with that of the placebo-oil controls. A higher dose of testosterone (10 mg/kg body-weight per d) failed to increase the daily weight gain. The increased growth rate of the testosterone-treated rats appeared to occur in the whole body and not specifically in muscle. There were no significant changes in body composition. The fractional synthetic rate of gastrocnemius muscle protein was higher in the hormone-treated rats than in controls. This contrasts with previous results for the anabolic agent trenbolone acetate and reflects differences in the mode of action of these two different steroids, both with androgenic properties.

Dissimilar atrial rhythms. A patient with triple right atrial rhythm

A patient with complete A-V block and atrial fibrillation was analyzed by multiple intra-atrial electrograms. Three areas were recorded in the right atrium, each of them with different electrophysiological properties: (1) persistent atrial standstill, (2) irregular atrial activity with a rate of 50/minute, and (3) fibrilloflutter waves with a rate of 450/minute. The latter were also registered in the left atrium. This case illustrates another form of dissimilar atrial rhythms, and provides additional evidence of the importance of recording multiple electrograms from each atrium in the evaluation of the atrial events in atypical atrial arrhythmias.