Large-scale brain networks account for sustained and transient activity during target detection

Target detection paradigms have been widely applied in the study of human cognitive functions, particularly those associated with arousal, attention, stimulus processing and memory. In EEG recordings, the detection of task-relevant stimuli elicits the P300 component, a transient response with latency around 300 ms. The P300 response has been shown to be affected by the amount of mental effort and learning, as well as habituation. Furthermore, trial-by-trial variability of the P300 component has been associated with inter-stimulus interval, target-to-target interval or target probability; however, understanding the mechanisms underlying this variability is still an open question. In order to investigate whether it could be related to the distinct cortical networks in which coherent intrinsic activity is organized, and to understand the contribution of those networks to target detection processes, we carried out a simultaneous EEG-fMRI study, collecting data from 13 healthy subjects during a visual oddball task. We identified five large-scale networks, that largely overlap with the dorsal attention, the ventral attention, the core, the visual and the sensory-motor networks. Since the P300 component has been consistently associated with target detection, we concentrated on the first two brain networks, the time-course of which showed a modulation with the P300 response as detected in simultaneous EEG recordings. A trial-by-trial EEG-fMRI correlation approach revealed that they are involved in target detection with different functional roles: the ventral attention network, dedicated to revealing salient stimuli, was transiently activated by the occurrence of targets; the dorsal attention network, usually engaged during voluntary orienting, reflected sustained activity, possibly related to search for targets.     

Costs of Bloodstream Infections Caused by Escherichia coli and Influence of Extended-Spectrum-β-Lactamase Production and Inadequate Initial Antibiotic Therapy

Escherichia coli is the leading cause of bloodstream infections (BSIs) caused by Gram-negative bacteria. The increasing prevalence of antibiotic-resistant E. coli strains, particularly those producing extended-spectrum β-lactamases (ESBLs), increases the odds that empirically prescribed antimicrobial therapy for these infections will be inadequate, but the economic impact of this risk has not been fully evaluated. In the present retrospective 1-year analysis of 134 consecutive E. coli BSIs in our hospital, we explored the clinical and economic impacts of (i) inadequate initial antimicrobial treatment (IIAT) (i.e., empirical treatment with drugs to which the isolate had displayed in vitro resistance) of these infections and (ii) ESBL production by the bloodstream isolate. Cost data were obtained from the hospital accounting system. Compared with the 107 (79.8%) adequately treated patients, the 27 (20.1%) who received IIAT had a higher proportion of ESBL BSIs (74.0% versus 15.8%), longer (+6 days) and more costly (+EUR 4,322.00) post-BSI-onset hospital stays, and higher 21-day mortality rates (40.7% versus 5.6%). Compared with the 97 non-ESBL infections, the 37 (27.6%) ESBL BSIs were also associated with longer (+7 days) and more costly (+EUR 5,026.00) post-BSI-onset hospital stays and increased 21-day mortality (29.7% versus 6.1%). These findings confirm that the hospital costs and mortality associated with E. coli BSIs are significantly increased by ESBL production and by IIAT.Escherichia coli is the leading cause of bloodstream infections (BSIs) involving Gram-negative bacteria (16, 37). The last 20 years have witnessed a striking increase in the number of infections caused by antibiotic-resistant strains of E. coli, and this has had an important impact on the outcomes of BSIs (24). Multidrug-resistant (MDR) E. coli strains and particularly those that produce extended-spectrum β-lactamases (ESBL) not only are endemic in many health care settings but also have become an important cause of community-acquired infections (1, 27, 28). These organisms are resistant to many of the antimicrobial agents usually recommended for the treatment of infections caused by E coli, so the odds are quite high that empirically prescribed antimicrobial therapy will be ineffective against these infections (4, 9, 18, 22, 23, 25, 26, 29, 32, 35).Our previous studies showed that failure to provide prompt, effective antimicrobial therapy for BSIs caused by ESBL-producing E. coli is associated with increased mortality and longer hospital stays (35, 36). Similar findings have been reported by others (15, 18, 20, 24, 31, 32). Length of stay (LOS) has been identified as the single most important determinant of costs related to inpatient care for bacteremia (3). Inadequate initial antimicrobial therapy (IIAT) has been shown to increase hospitalization costs related to intra-abdominal and other sterile-site infections caused by methicillin-resistant Staphylococcus aureus (33), but this issue has not been specifically explored with reference to BSIs caused by E. coli. This information is essential for identifying/developing cost-effective measures for curbing the spread of antimicrobial-resistant isolates (7). We conducted a retrospective cohort study to explore the clinical and economic impacts of ESBL production and IIAT of E. coli BSIs.     

The effects of continuous positive airway pressure on plasma brain natriuretic peptide concentrations in patients presenting with acute cardiogenic pulmonary edema with preserved left ventricular systolic function

Background

It has been established that plasma brain natriuretic peptide (BNP) concentrations in patients with acute cardiogenic pulmonary edema (ACPE) increase in proportion to heart failure.

Objectives

The aim of this study is to assess the effects of continuous positive airway pressure (CPAP) treatment on plasma BNP concentrations in patients presenting with ACPE with preserved left ventricular (LV) systolic function.

Methods

This was a prospective, observational single-center study in the emergency unit of Valduce Hospital. Twelve patients (group A) presenting with ACPE and preserved LV ejection fraction and 14 patients (group B) with systolic heart dysfunction (LV ejection fraction <45%) underwent CPAP (10 cm H₂O) through a face mask and standard medical therapy. Plasma BNP concentrations were collected immediately before CPAP and 3, 6, and 24 hours after treatment. All patients underwent a morphological echocardiographic investigation shortly before CPAP.

Results

Three hours after admission, BNP significantly decreased in patients with ACPE and preserved LVEF (from 998 ± 467 pg/mL to 858 ± 420 pg/mL; P < .05), whereas in those with systolic dysfunction, BNP was higher than during baseline (from 1352 ± 473 pg/mL to 1570 ± 595 pg/mL; P < .05).

Conclusions

The preliminary results of the present study show that CPAP, after 3 hours, lowers BNP levels in patients with ACPE and preserved LV systolic function compared with patients affected by systolic ACPE dysfunction where BNP levels do not change significantly.     

Quantifying the role of PSA screening in the US prostate cancer mortality decline

OBJECTIVE: To quantify the plausible contribution of prostate-specific antigen (PSA) screening to the nearly 30% decline in the US prostate cancer mortality rate observed during the 1990s. METHODS: Two mathematical modeling teams of the US National Cancer Institute's Cancer Intervention and Surveillance Modeling Network independently projected disease mortality in the absence and presence of PSA screening. Both teams relied on Surveillance, Epidemiology, and End Results (SEER) registry data for disease incidence, used common estimates of PSA screening rates, and assumed that screening, by shifting disease from distant to local-regional clinical stage, confers a corresponding improvement in disease-specific survival. RESULTS: The teams projected similar mortality increases in the absence of screening and decreases in the presence of screening after 1985. By 2000, the models projected that 45% (Fred Hutchinson Cancer Research Center) to 70% (University of Michigan) of the observed decline in prostate cancer mortality could be plausibly attributed to the stage shift induced by screening. CONCLUSIONS: PSA screening may account for much, but not all, of the observed drop in prostate cancer mortality. Other factors, such as changing treatment practices, may also have played a role in improving prostate cancer outcomes.     

Sodium hyaluronate in treatment of diffuse nephrogenic adenoma of the bladder in a child

Nephrogenic adenoma is a rare, benign lesion of the bladder, occurring as an epithelial response to chronic infection or trauma, probably arising from nephrogenic metaplasia. In contrast to nephrogenic adenomas in adults, who present with this tumor in the entire ureteral tract, it has been observed exclusively in the bladder of children thus far. We report and discuss here the case of a 12-year-old boy with diffuse calculus-producing nephrogenic adenoma successfully treated with sodium hyaluronate.