The role of the magnocellular and parvocellular systems in the redundant target effect

The redundant target effect (RTE) consists in the speeding of reaction time with single versus multiple targets and can be explained either by a neural coactivation or by a race model. To try to understand the role of the magnocellular and parvocellular systems in the determination of the RTE we carried out three experiments using onset or feature singletons. The former are likely to be mainly processed by the magnocellular system while the latter are mainly processed by the parvocellular system. In experiment 1 we found an RTE both when the target (red disk) was presented in isolation and when it was surrounded by equiluminant green distractors. Thus, the RTE occurred both with onset and feature singletons. However, with the former, the RTE could be accounted for by neural coactivation while with the latter it could be accounted for by a probabilistic explanation. In experiment 2 we tried to ascertain the role of distractors in yielding a probabilistic RTE: we used either targets in isolation or surrounded by distractors of lower luminance and found an RTE that could be explained by neural coactivation for both kinds of targets. This ruled out an effect of distractors per se in determining a probabilistic RTE. Finally, in experiment 3 we used targets of lower luminance than either the background or the distractors. We found that the RTE could be accounted for by neural coactivation with targets alone while it was probabilistic with distractors. Overall, these results show that stimuli presumably processed by the magnocellular system yield redundancy gains that result from a neural coactivation mechanism. In contrast, stimuli presumably processed by the parvocellular system are compatible with a probabilistic redundancy gain.     

Candesartan cilexetil protects cavernous tissue in spontaneously hypertensive rats

In previous experiments, our group demonstrated morphological changes in erectile tissue from male spontaneously hypertensive rats (SHR). The present study was performed to determine whether an angiotensin II receptor blocker could protect cavernous tissue (CT) from these structural alterations in SHR. Male SHR and Wistar-Kyoto (WKY) rats were studied during 4 months. Rats were divided into three groups: SHR (n=10), SHR with candesartan cilexetil (n=10) and WKY rats (n=10). Candesartan cilexetil 7.5 mg/kg/day was administered orally throughout the study. CT was processed for pathology studies. The amount of (1) cavernous smooth muscle (CSM), (2) vascular smooth muscle (VSM), (3) collagen type III, and the rat endothelial cell antibody (RECA-1)/tunica media ratio in cavernous arteries were evaluated. SHR with candesartan cilexetil showed a lower blood pressure, a lower percentage of CSM, smaller VSM area, with a higher RECA-1/media ratio, and a lower percentage of collagen type III, when compared to untreated SHR. In addition, SHR showed a positive correlation between systolic blood pressure (SBP) and CSM amount (r=0.91; P<0.01), and SBP and the percentage of collagen type III (r=0.88; P<0.01); these correlations were not observed either in SHR treated with candesartan cilexetil or in WKY rats. We conclude that candesartan cilexetil provides a significant protective role against morphologic changes in vessels as well as in cavernous spaces of the erectile tissue, caused by high blood pressure, in SHR.     

Prevalence of sexual dysfunctions in Argentina

The objective of this study consisted in assessing the prevalence of erectile dysfunction (ED) and other sexual dysfunctions in a group of men who attended a prostate awareness week campaign. In total, 2715 men attended to 'Semana de la Prostata 2001' campaign and received an additional questionnaire on sexual health. The prevalence of ED, desire and ejaculatory disorders was of 41.7, 33.8 and 49.3%, respectively; however, not all of them lived these difficulties as a real sexual problem because only 918 men (37.8%) acknowledged having 'any sexual difficulty'. Only 13.7% of the attendees consulted a physician for this reason in the past. This first Argentinean study proves the high prevalence of sexual dysfunctions in our population.     

Non-invasive diagnosis of Helicobacter pylori infection: simplified 13C-urea breath test, stool antigen testing, or DNA PCR in human feces in a clinical laboratory setting?

OBJECTIVES: (1) To compare two stool antigen EIAs (HpSA, FemtoLab) and PCR of ureaseA and cagA in feces, with (13)C-urea breath test (UBT). (2) To ascertain whether a simplified UBT (breath collection time = 10 min) is as reliable as the standard assay (30 min). DESIGN AND METHODS: Helicobacter pylori status was recorded in Group 1 (n = 187) by UBT, H. pylori stool antigen, ureA and cagA PCR in feces. UBT with 10, 20 and 30 min sampling was performed in Group 2 patients (n = 283). RESULTS: The sensitivity and specificity of HpSA, FemtoLab, and ureA were 67% and 99%, 90% and 96%, 35% and 98%, respectively. cagA results were positive in 16/48 H. pylori-positive, and in 5/100 H. pylori-negative patients. The results of UBT with a 10- and 30-min sampling strictly overlapped. CONCLUSION: UBT with 10 min breath collection and FemtoLab stool antigen assay are the most reliable non-invasive tests to diagnose H. pylori infection.     

Epilepsy and depression: risk factors for suicide?

Compared to the general population, the suicide rate in epilepsy is 5-fold increased. In particular, patients with temporal lobe epilepsy have a 25-fold increased risk of suicide. Certain psychiatric disorders, including primary mood disorders, also increase the risk for suicide. Among people with epilepsy, psychiatric comorbidity is common, with an elevated rate of Major Depression. A review of the literature about the association between epilepsy, depression and suicide highlights the lack of evaluation of intensity, pervasiveness and characteristics of suicidal ideation in epileptic patients compared with patients with a diagnosis of Major Depression.     

A ten-year risk evaluation study in Catania hospital operating rooms

Previous studies conducted in Catania hospitals have revealed a high burden of contamination in the air of operating rooms and have recommended measures to improve air quality. In this study we verified the effectiveness of the undertaken measures. Furthermore we evaluated the possibility of using microclimatic parameters as "markers" of operating room contamination. Changes made to ventilation systems and to waste gas scavenging systems in the monitored operating rooms were remarkably effective. Microclimatic conditions and degree of chemical contamination improved over time; nevertheless airflow velocity values were found to be insufficient and nitrous oxide values, in some cases, remained slightly elevated. A significant correlation was observed only between some nitrous oxide values and relative humidity. Monitoring important marker levels is useful for correctly evaluating operating room thermal, chemical and microbiological air quality.     

Theory of mind,social development,and psychosis

The difficulty in interpreting other people’s mental states found in children with autism and in people affected by schizophrenia may be explained in terms of a unique mental process called Theory of Mind. The paper discusses the main operational issues of such a peculiar aspect of social cognition, the Theory of Mind, and its implication in schizophrenia, including a review of its related neural structures. Theory of Mind abilities may be a relevant aspect of social interaction involving people affected by schizophrenia, and they need to be further investigated in clinical research.