Neurotransmitter and endocrine modulation of aggressive behavior and its components in normal humans.

Correlations between aggressiveness and its components and plasma concentrations of norepinephrine (NE), epinephrine (EPI), testosterone (T), cortisol (Cort) and prolactin (Prl) were studied in 158 physically and psychologically healthy male volunteers. Global aggressiveness, examined directly in the probands by the Buss-Durkee Hostility Inventory (BDHI), was not correlated with any of the biochemical parameters investigated, but reports by first-degree relatives and spouses showed positive correlations between global aggressiveness and NE and T levels. The BDHI scores for 'irritability' and 'resentment' were positively correlated with NE, T and Cort.

Flumazenil effects on growth hormone response to gamma-hydroxybutyric acid.

Gamma-hydroxybutyric acid (GHBA) has been recently introduced for alcohol detoxication but few data are available concerning the central mechanism of action of this gamma-aminobutyric acid (GABA) catabolite. GHBA ability to stimulate growth hormone (GH) and prolactin (PRL) secretion has been reported: the involvement of GABA, dopamine or serotonin systems acting on pituitary hormones has been hypothesized. In the present study we investigated GH and PRL responses to GHBA with or without flumazenil (a benzodiazepine receptor antagonist) i.v. pretreatment. Our study included nine male healthy volunteers (aged 23.2 +/- 2.5 years) who were submitted to three tests in random order: (1) oral GHB administration; (2) oral GHBA and i.v. flumazenil administration; (3) oral placebo and i.v. saline administration. Blood samples for GH and PRL assays were collected during the three tests at -15, 0, 15, 30, 45, 60 and 90 min. GHBA induced a significant increase in GH plasma levels; flumazenil pretreatment antagonized GHBA action on GH secretion. No changes were obtained with placebo and saline administration. A subpopulation of GABA receptors or GHBA-specific receptors seems to be involved in GHBA action. The benzodiazepine receptor antagonist flumazenil was able to influence the sensitivity and the neuroendocrine consequences of GHBA binding site stimulation.

A multicentre study to evaluate the effect of sulbactam/ampicillin combination on anaerobic micro-organisms.

Ampicillin combined with the beta-lactamase inhibitor sulbactam was compared with ampicillin alone, cefoxitin and metronidazole against 569 clinical strains of anaerobic organisms. The strains included 289 species of Bacteroides, 160 strains of Clostridium and 120 strains of various species of Streptococcus/Peptostreptococus, Fusobacterium, Veillonella, Eubacterium, Bifidobacterium, Actinomyces and Propionibacterium. Sulbactam/ampicillin was as effective as cefoxitin and metronidazole against all anaerobic species tested, inhibiting more than 90% of strains at the breakpoints (16, 32 and 32 mg/l, respectively). Sulbactam/ampicillin was also significantly more active than ampicillin against strains of Bacteroides, the minimal inhibitory concentration being at least four-fold lower. In contrast, the activity of the combination did not differ from that of ampicillin alone against Fusobacterium species and Gram-positive rods and cocci.

The diagnosis of small bowel bacterial overgrowth. Reliability of jejunal culture and inadequacy of breath hydrogen testing.

The reliability of a single jejunal culture in the diagnosis of small bowel bacterial overgrowth has recently been questioned. Seventy-seven patients thought to have bacterial overgrowth, defined as a jejunal culture yielding at least 10(6) organisms per milliliter of aspirate, took part in the study. Bacterial overgrowth was found in 74% of the patients with predisposing conditions and in 32% of those with no clear causes of bacterial colonization. The intestinal juice of some patients was taken at two different levels of the proximal jejunum, using both the closed- and open-tube systems. Highly significant correlations (rs = 0.90, p less than 0.001) were found between the numbers of bacteria per milliliter at the 2 jejunal levels and between the numbers of bacteria per milliliter of jejunal aspirate obtained from the closed and open tubes (rs = 0.84, p less than 0.001). Compared with the jejunal culture, the gas chromatography of volatile fatty acids in jejunal aspirate and the glucose- and lactulose-hydrogen breath tests showed sensitivities of 56%, 62%, and 68% and specificities of 100%, 83%, and 44%, respectively. This work demonstrates the reliability of jejunal cultures and the inadequacy of breath hydrogen testing in the prediction of positive jejunal cultures. When results of testing for volatile fatty acids in jejunal aspirates are positive, this always indicates the presence of bacterial overgrowth; thus, this procedure would avoid the more complicated, time-consuming, and costly bacteriological analysis of jejunal samples.

Incidence of anti-hepatitis C virus antibodies in non-A, non-B post-transfusion hepatitis in an area of northern Italy.

A total of 210 patients consecutively submitted to heart surgery at the Parma University Hospital and transfused with 1,898 units of blood were followed after transfusion in order to evaluate both the incidence of anti-hepatitis C virus (HCV) seroconversion in non-A, non-B post-transfusion hepatitis (PTH-NANB) cases and the usefulness of the screening for anti-HCV in comparison with that for serum glutamic pyruvic transaminase (SGPT) values in preventing PTH-NANB transmission. Fifteen recipients developed PTH-NANB (group A); ten of them (66.6%) showed anti-HCV seroconversion within 3-12 months. Eight of the ten anti-HCV positive patients developed chronic hepatitis, but none of the five PTH-NANB anti-HCV negative did. None of the 15 controls (group B) randomly chosen among the patient population showed anti-HCV seroconversion. A close correlation with the transmission of PTH was showed by anti-HCV positivity but not by SGPT elevation in blood donors. Eleven of 172 blood products transfused to group A but none of 139 products transfused to group B were anti-HCV positive. The incidence of elevated SGPT values was similar between the two groups of the transfused blood products. Nevertheless, the correlation observed between anti-HCV positivity and SGPT levels in the blood products involved in PTH confirms the need to exclude blood donors with abnormal SGPT values. On the whole, anti-HCV screening of donors showed a predictive value higher than that of SGPT (100% vs. 53.3%), allowing a minor blood donation exclusion.(ABSTRACT TRUNCATED AT 250 WORDS)