Is motor perseveration in unilateral neglect 'driven' by the presence of neglected left-sided stimuli?

Unilateral spatial neglect refers to a difficulty in detecting or acting on information in a particular region of space. When asked to cross out stimuli distributed across a page, patients with neglect may miss many targets on the left. In addition, they have a tendency to return to, and re-mark, right-sided targets that they have already cancelled. A recent retrospective study has shown this effect to be specific to unilateral neglect rather than a consequence of right hemisphere damage in general. Here, a consecutive group of seven right-hemisphere neglect patients performed five versions of a standard cancellation task, each version differing in the quantity of left-sided information presented. All of the participants showed perseveration on right-sided targets in the basic task. A highly significant and linear reduction in perseverative behaviour was observed as left-sided information was removed. In a second study, left-sided targets were again progressively removed but, in this case, were replaced with an additional distractor item, keeping the total quantity of stimuli presented in each condition constant. Again, a significant reduction in right-sided perseveration was observed, indicating a high degree of selectivity to the effect. The results show that a difficulty in perceiving existing cancellation marks, or a non-spatially specific motoric perseveration, are unlikely to fully account for this behaviour. As the patients omitted almost all targets on the left side of the basic cancellation task, the results suggest a striking influence on apparently intentional behaviour from un-cancelled information within the neglected field.     

Delta Opioid activation of the Mitogen-activated protein kinase cascade does not require transphosphorylation of Receptor Tyrosine Kinases

Background

The peroxisome proliferator-activated receptor α (PPARα) plays an important role in the metabolism of lipoproteins and fatty acids, and seems to protect against the development of atherosclerosis. To evaluate the possible protective role of PPARα on cardiovascular function, the effect of the PPARα agonist, fenofibrate was assessed with respect to ischaemia/reperfusion injury and endothelial function in mice.

Results

Fenofibrate treatment reduces myocardial infarction size and improves post-ischaemic contractile dysfunction. Hearts from PPARα null mice exhibit increased susceptibility to ischaemic damages and were refractory to protection by fenofibrate treatment suggesting that the beneficial effects of fenofibrate were mediated via PPARα. Furthermore, fenofibrate improves endothelium- and nitric oxide-mediated vasodilatation in aorta and mesenteric vascular bed. A decreased inhibitory effect of reactive oxygen species in the vessel wall accounts for enhanced endothelial vasodilatation. However, the latter cannot be explained by an increase in nitric oxide synthase expression nor by an increase sensitivity of the arteries to nitric oxide.

Conclusions

Altogether the present data suggest that fenofibrate exerts cardioprotective effect against ischaemia and improves nitric oxide-mediated response probably by enhancing antioxidant capacity of the vessel wall. These data underscore new therapeutic perspectives for PPARα agonists in ischaemic myocardial injury and in cardiovascular diseases associated with endothelial dysfunction.     

Breaking up the tie: disintegrin-like metalloproteinases as regulators of cell migration in inflammation and invasion

Cell adhesion and cell migration are essential for a variety of important events in both embryonic development and in the adult organism. Cell adhesion molecules (CAM) like selectins, immunoglobulin superfamily members, integrins, and cadherins undergo diverse mechanisms of regulation. Dysregulation of adhesion can lead to pathological processes, including inflammatory diseases or tumor metastasis either by disrupting the normal anchorage, thereby altering cell movement and regulatory signalling, or by promoting inappropriate temporal and spatial adhesion. An increasing body of evidence has emerged showing that members of the a disintegrin and metalloproteinase (ADAM) family critically contribute to the regulation of CAM functions. While the disintegrin domain can interact with integrins and mediate adhesion, the metalloproteinase domain can mediate anti-adhesive functions by cleaving the membrane bound adhesion molecules. This "shedding" process leads to the release of often still functional soluble ectodomains and can additionally influence intracellular cell signalling pathways. Several soluble CAMs have been detected in vitro and in vivo. Some of them are strongly increased in inflammatory diseases or in the serum of cancer patients. Therefore the level of soluble CAMs but also the expression of the metalloproteinases responsible for their release might provide prognostic information. It could also be useful for monitoring malignant disease stages and for evaluating the effectiveness of various therapeutic approaches. Moreover, metalloproteases of the ADAM family are emerging as promising targets for new therapeutic options.     

How expert are the experts? An exploration of the concept of 'expert' within Delphi panel techniques

The use of the term 'expert' occurs widely in healthcare research, in the context of national guidelines and consensus methods for the development of clinical protocols. Within consensus methods of research, especially Delphi panel techniques, the use of 'experts' is fundamental to reliability. Yet literature fails to debate the practicalities of defining 'experts' for use within Delphi panel research. This paper, by John Baker and colleagues, draws on methodological literature and discusses the concepts and elements of 'experts'. It concludes with recommendations for researchers to ensure experts for future Delphi research.     

The progression of cognition, psychiatric symptoms, and functional abilities in dementia with Lewy bodies and Alzheimer disease

BACKGROUND: Although dementia with Lewy bodies (DLB) may be one of most common forms of dementia, relatively little is known about its cognitive and functional course. OBJECTIVE: To compare change over time in general cognitive status, memory test performance, psychiatric symptoms, neurological signs, and functional abilities in patients with probable DLB and probable Alzheimer disease (AD). DESIGN: Twenty-eight patients who met diagnostic criteria for DLB were recruited into the study from 3 sites. Patients with AD (n = 55) were selected from a larger cohort and matched 2 to 1 to the patients with DLB on age and baseline global cognitive status. Patients were followed up at 6-month intervals for an average of 6.2 visits and assessed at each visit with tests of global cognitive functioning and verbal learning and memory and measures of psychiatric, neurological, and functional status. RESULTS: At the baseline evaluation, patients with DLB performed more poorly on a measure of constructional praxis and all measures of functional status. They also had more severe psychiatric symptoms and neurological signs than the AD group. Despite these initial differences, generalized estimating equations applied to regression analyses with repeated measures determined that the only difference between the 2 groups in change in cognitive test performance was on a measure of recognition memory; patients with AD declined, while patients with DLB remained relatively stable. Patients with DLB had relatively stable behavioral symptoms and visual illusions, whereas patients with AD had a significant increase in these symptoms over time. Neurological and functional changes over time were similar in the 2 groups. CONCLUSIONS: Both baseline and longitudinal differences between patients with DLB and patients with AD were noted; these have implications for clinical diagnosis and treatment.     

Care practices on the resuscitation of newborns in the context of a delivery center

Approximately 10 to 15% of the neonates present difficulties in adapting to extra uterine life, which requires ability and readiness from the professional to intervene properly. This is an observational, cross-sectional study aimed at describing the care practices on the resuscitation of the newborn in the Delivery Center of a public hospital in the city of S?o Paulo. Data were obtained from the observation of 100 assistances given by health care professional staff and were recorded on a check-list instrument. Meconium-amniotic fluid was found in 24 (24.0%) births and 47 (47.0%) newborns were submitted to respiratory airways aspiration. Of these, 6.4% (3) had their trachea aspirated. 26 (26.0%) newborns were ventilated, 5 (19.2%) of which by mask plus positive pressure; 1 (1.0%) newborn was submitted to a chest compression. After the initial resuscitation procedures, 6 (6.0%) newborns were referred to the neonatal intensive care unit.     

Comparison of lifestyle and health among Danish nurses and the Danish female population: is it possible to generalize findings from nurses to the general female population?

AIMS: To generalize findings from a nursing population to the general female population, the aim of this study was to compare lifestyle and health among Danish female nurses with that among Danish women. Furthermore, the aim was to compare lifestyle and health among Danish female nurses with women belonging to the same socio-economic group as nurses. METHODS: Danish females above the age of 44 in 1999 (n = 22,715) were compared with a group of women from the Danish Health and Morbidity Survey conducted in 2000 (n = 4,445). Age standardized risk ratios (SRR) with 95% confidence intervals were calculated to compare the two groups. RESULTS: Nurses smoke less (SRR 0.74, CI: 0.70-0.78) and are more physically active (SRR 2.53, CI: 2.31-2.77) when compared with the general female population. A higher percentage of nurses consume five drinks or more on a weekday compared with the general female population (SRR 2.68, CI: 2.25-3.19). When comparing nurses with women belonging to the same socio-economic group, these differences are also found to be statistically significant, but no differences are found according to overweight/obesity, self-reported health and limitations in daily activities when nurses are compared with women belonging to the same socio-economic group. CONCLUSIONS: In general, Danish nurses have a healthier lifestyle than other Danish women. In future studies, differences and similarities in lifestyle and health between nurses and other women should be considered when generalizing findings from Danish nurses to the Danish female population.