Neurophysiology of prehension. III. Representation of object features in posterior parietal cortex of the macaque monkey

Neurons in posterior parietal cortex (PPC) may serve both proprioceptive and exteroceptive functions during prehension, signaling hand actions and object properties. To assess these roles, we used digital video recordings to analyze responses of 83 hand-manipulation neurons in area 5 as monkeys grasped and lifted objects that differed in shape (round and rectangular), size (large and small spheres), and location (identical rectangular blocks placed lateral and medial to the shoulder). The task contained seven stages -- approach, contact, grasp, lift, hold, lower, relax -- plus a pretrial interval. The four test objects evoked similar spike trains and mean rate profiles that rose significantly above baseline from approach through lift, with peak activity at contact. Although representation by the spike train of specific hand actions was stronger than distinctions between grasped objects, 34% of these neurons showed statistically significant effects of object properties or hand postures on firing rates. Somatosensory input from the hand played an important role as firing rates diverged most prominently on contact as grasp was secured. The small sphere -- grasped with the most flexed hand posture -- evoked the highest firing rates in 43% of the population. Twenty-one percent distinguished spheres that differed in size and weight, and 14% discriminated spheres from rectangular blocks. Location in the workspace modulated response amplitude as objects placed across the midline evoked higher firing rates than positions lateral to the shoulder. We conclude that area 5 neurons, like those in area AIP, integrate object features, hand actions, and grasp postures during prehension.     

Current assessments of quality and safety education in nursing

Concerns about the quality and safety of health care have changed practice expectations and created a mandate for change in the preparation of health care professionals. The Quality and Safety Education for Nurses project team conducted a survey to assess current levels of integration of quality and safety content in pre-licensure nursing curricula. Views of 195 nursing program leaders are presented, including information about satisfaction with faculty expertise and student competency development related to 6 domains that define quality and safety content: patient-centered care, teamwork and collaboration, evidence-based practice, quality improvement, safety, and informatics. With competency definitions as the sole reference point, survey respondents indicated that quality and safety content was embedded in current curricula, and they were generally satisfied that students were developing the desired competencies. These data are contrasted with work reported elsewhere in this issue of Nursing Outlook and readers are invited to consider a variety of interpretations of the differences.     

Comparing hand washing to hand sanitizers in reducing elementary school students' absenteeism

PURPOSE: To compare the efficacy of an alcohol-based hand sanitizer to standard hand washing in reducing illness and subsequent absenteeism in school-age children. METHOD: A randomized cross-over design was used with 18 classrooms of 2nd and 3rd grade students (n = 383) from 4 elementary schools. Half of the classes from each school used an anti-microbial gel hand sanitizer while the other half used soap and water for regular hand hygiene for 2 months, then, the students switched cleaning methods for the following 2 months. RESULTS: No significant differences in absenteeism rates were demonstrated. A follow-up focus group comprised of teachers and school nurses indicated that hand sanitizers were preferred over soap and water. CONCLUSION: Hand sanitizers are an appropriate alternative to hand washing for hand cleansing and may offer additional benefits in the school setting.     

Phosphoinositide 3-kinase(p110alpha) plays a critical role for the induction of physiological, but not pathological, cardiac hypertrophy

An unresolved question in cardiac biology is whether distinct signaling pathways are responsible for the development of pathological and physiological cardiac hypertrophy in the adult. Physiological hypertrophy is characterized by a normal organization of cardiac structure and normal or enhanced cardiac function, whereas pathological hypertrophy is associated with an altered pattern of cardiac gene expression, fibrosis, cardiac dysfunction, and increased morbidity and mortality. The elucidation of signaling cascades that play distinct roles in these two forms of hypertrophy will be critical for the development of more effective strategies to treat heart failure. We examined the role of the p110alpha isoform of phosphoinositide 3-kinase (PI3K) for the induction of pathological hypertrophy (pressure overload-induced) and physiological hypertrophy (exercise-induced) by using transgenic mice expressing a dominant negative (dn) PI3K(p110alpha) mutant specifically in the heart. dnPI3K transgenic mice displayed significant hypertrophy in response to pressure overload but not exercise training. dnPI3K transgenic mice also showed significant dilation and cardiac dysfunction in response to pressure overload. Thus, PI3K(p110alpha) appears to play a critical role for the induction of physiological cardiac growth but not pathological growth. PI3K(p110alpha) also appears essential for maintaining contractile function in response to pathological stimuli.     

Interleukin-3 treatment of rhesus monkeys leads to increased production of histamine-releasing cells that express interleukin-3 receptors at high levels

To understand the hematopoietic and nonhematopoietic responses to interleukin-3 (IL-3), expression of cell-surface IL-3 receptors (IL-3R) was examined on bone marrow (BM) cells and peripheral blood (PB) cells of rhesus monkeys during the course of in vivo IL-3 treatment. Whereas IL-3R expression is low in untreated monkeys, IL-3 administration led to a gradual increase in both low- and high-affinity binding sites for IL-3. This increase reflected the total number of cells expressing IL- 3Rs, as detected by flow cytometry using biotinylated IL-3. Most of these IL-3R+ cells in both BM and PB could be characterized as basophilic granulocytes that contained high levels of histamine. In contrast to the effect on these differentiated cells, IL-3 administration did not significantly alter the low level IL-3R expression on immature, CD34+ cells. Further flow cytometric analysis using biotinylated growth factors showed that the IL-3R+ basophils also expressed receptors for granulocyte-macrophage colony-stimulating factor (GM-CSF), but not for IL-6 or Kit ligand. These findings indicated that the IL-3R+ cells included neither monocytes, which express GM-CSFRs and IL-6Rs abundantly, nor mast cells, which express c- kit. By combining flow cytometric and Scatchard data, it was calculated that the basophils contain as many as 1 to 2 x 10(3) high-affinity IL- 3Rs and 15 to 30 x 10(3) low-affinity sites. The finding that in vivo IL-3 treatment leads to the production of large numbers of cells that express high levels of IL-3R and are capable of producing histamine provides an explanation for the often severe allergic reactions that occur during prolonged IL-3 administration. It also indicates that IL- 3, in addition to its direct effects on hematopoietic cells, may also stimulate hematopoiesis through the release of secondary mediators such as histamine by IL-3-responsive mature cells.     

Fractional Exhaled Nitric Oxide in the Interpretation of Specific Inhalational Challenge Tests for Occupational Asthma

Purpose

Fractional exhaled nitric oxide (FE_NO) measurements are recommended for the assessment of eosinophilic airway inflammation in asthma. Clinically relevant increases in FE_NO have been reported 24 h after positive specific inhalational challenge (SIC) tests in occupational asthma. We aimed to determine whether positive SICs could be discriminated from control tests, on the basis of change in FE_NO.

Methods

We reviewed all positive SICs to a variety of agents performed at our institution 2008–2012 and gathered data on age, sex, asthmatic response (immediate/dual/late), smoking status, inhaled corticosteroid usage, and FE_NO pre- and 24-h postcontrol and positive SIC from each worker. Changes in FE_NO after positive SICs were compared with control SICs from each worker, by using paired Student’s t tests.

Results

In 16 workers, negative control challenges were associated with mean changes in FE_NO of 9 % (95 % CI ?1.14 to 19.01) or 1.1 ppb (95 % CI ?3.59 to 5.84); 2 of 16 (13 %) workers tested showed increases in FE_NO that were clinically relevant based on recent guidelines. Subsequent positive SICs were associated with mean changes in FE_NO of 7 % (95 % CI ?15.73 to 29.6) or 2.1 ppb (95 % CI ?6.07 to 10.19), which were not significantly different to controls; only 2 of 16 (13 %) workers had FE_NO changes that were clinically relevant.

Conclusions

FE_NO changes above the upper confidence limits of ≥20 % or ≥6 ppb may be considered to be outside the range of normality. However, the majority of workers who had clearly positive SICs to common low molecular weight agents also had no statistically or clinically relevant increase in FE_NO. Therefore, change in FE_NO does not predict a positive SIC in this group.