Long latency event-related potentials in rats: response of amygdala, nucleus accumbens, dorsal hippocampus and frontal cortex to changes in reward characteristics of conditioned stimuli

Circuits involving major afferents to the ventral striatum from the frontal cortex, amygdala and hippocampus have been implicated in the selective processing of conditioned stimuli predictive of ‘important events' or reward-related processes. We utilized an animal model of event-related potentials (ERPs) to explore the relationship between these brain areas during the performance of a conditioning/extinction task. Significant reductions in the N1 component in cortex and P2 component in amygdala of the rat ERP were found as a consequence of removal of the food reward previously associated with the stimuli. Lesions of the nucleus basalis magnocellularis were without effect on the pattern of ERP morphology changes associated with the removal of the reward. Since the N1 component of the ERP has been linked to attentional processes, these studies suggest that elimination of reward characteristics of conditioning stimuli can lead to a specific reductions in ‘attention' and or ‘sensory reaction' in frontal cortex and amygdala but not to general habituation to these stimuli or in other areas of the CNS.     

Identification of second malignancies on effusions and fine-needle aspirates using a panel of monoclonal antibodies.

The longer survival of neoplastic patients achieved through improvements of therapeutic regimens has increased the relative risk of developing a second primary tumour (SPT). In this context, conventional cytopathology can define tumour histotype only in a small fraction of cases. In this study, we have evaluated whether selected combinations of monoclonal antibodies (MAbs) to tumour-associated antigens (TAAs) can increase the accuracy of conventional morphology in detecting second primary tumours (SPTs) in two particularly difficult areas of cytodiagnosis, namely that of effusions and pulmonary fine-needle aspirates (FNAs). The immunocytochemical (ICC) analysis of 334 cytological specimens demonstrated that the use of our selected panel of MAbs could allow a more efficient identification of SPTs in comparison with conventional morphology. This diagnostic improvement was statistically significant (P < 0.0001). The present findings show that the immunophenotyping of effusions and FNAs, providing a more accurate and objective identification of SPTs, may have significant therapeutic and epidemiological relevance.     

Risk factors for oxacillin/methicillin resistance in coagulase-negative staphylococci

The clinical variables associated with isolation of oxacillin- and methicillin-resistant, coagulase-negative staphylococci (CNS) from blood cultures of hospitalized patients were studied. One hundred CNS strains (49 oxacillin-susceptible; 51 oxacillin-resistant) isolated consecutively from one of two or more sets of blood cultures were collected. Only two variables were independently associated with recovery of oxacillin/methicillin-resistant strains by a multivariate analysis: length of hospital stay >10 days (OR 5·2, 95% CI = 1·7–15·7), and administration of antimicrobial agents in the previous 14 days (OR 4·5, 95% CI = 1·7–11·7). Analysis of the antibiotics administered indicated that only β-lactams were associated with a statistically significant risk of resistance to oxacillin/methicillin (OR of β-lactams vs no antibiotics = 6·94, 95% CI = 1·9–25·3; OR of non-β-lactams vs no antibiotics = 2·64, 95% CI = 0·8–8·3). Length of hospital stay (especially >10 days) and prior administration of antimicrobial agents (mainly β-lactams) independently predicted the presence of oxacillin/methicillin-resistant CNS in blood cultures.     

Factors associated with the appropriate use of preoperatory hospital stays: historical cohort study

Background  

To ensure the highest efficiency, health services should be provided with the least possible complexity. The aim of this study is to quantify the degree of appropriateness in preoperatory hospital stays and to analyse those factors associated with a greater inappropriate use.     

In vitro contamination of "piggyback/heparin lock" assemblies: prevention of contamination with a closed, positive locking device (Click-Lock)

Direct contact and airborne transmission are established modes of microbial contamination of standard intravenous (iv) assemblies such as piggyback and heparin lock. In this study, 60% of the standard iv assemblies inoculated with Staphylococcus aureus (S. aureus) at the barrel of their exposed needle grew these organisms when cultured in a Soy Casein Digest Broth (SCDB). Also, 40 closed, positive locking iv assemblies (Click-Lock) were inoculated at possible contamination sites, and none of these assemblies grew S. aureus in a SCDB. These in vitro studies suggest that a closed, positive locking iv assembly such as the Click-Lock device may substantially reduce, and potentially prevent contamination of iv systems.     

Reduction in urinary free cortisol during benzodiazepine treatment of panic disorder

Urinary free cortisol (UFC) levels were measured at baseline and at four and eight weeks after initiation of treatment in 66 patients who met DSM-III-R criteria for primary panic disorder (PD). Thirty-seven normal control subjects also had UFC levels measured three times at monthly intervals. Patients were randomly assigned to treatment with alprazolam, diazepam, or placebo. At baseline, complicated PD patients (those with agoraphobia and secondary depression) had significantly higher UFC levels than did normal controls. At four and eight weeks, complicated PD patients receiving alprazolam and diazepam had significant reductions in UFC excretion compared to baseline. Patients with uncomplicated PD maintained UFC levels comparable to controls at each sampling period. Treatment with benzodiazepines did not lower UFC levels in this group. These findings suggest that patients with complicated PD demonstrate hyperactivity of the hypothalamo-pituitary-adrenal axis that is decreased by treatment with benzodiazepines.