Optimising care of acute coronary syndromes in three Australian hospitals

Objective. To improve quality of in-hospital care of patients with acute coronary syndromes using a multifaceted quality improvement program. Design. Prospective, before and after study of the effects of quality improvement interventions between October 2000 and August 2002. Quality of care of patients admitted between 1 October 2000 and 16 April 2001 (baseline) was compared with that of those admitted between 15 February 2002 and 31 August 2002 (post-intervention). Setting. Three teaching hospitals in Brisbane, Australia. Study participants. Consecutive patients (n = 1594) admitted to hospital with acute coronary syndrome [mean age 68 years (SD 14 years); 65% males]. Interventions. Clinical guidelines, reminder tools, and educational interventions; 6-monthly performance feedback; pharmacist-mediated patient education program; and facilitation of multidisciplinary review of work practices. Main outcome measures. Changes in key quality indicators relating to timing of electrocardiogram (ECG) and thrombolysis in emergency departments, serum lipid measurement, prescription of adjunctive drugs, and secondary prevention. Results. Comparing post-intervention with baseline patients, increases occurred in the proportions of eligible patients: (i) undergoing timely ECG (70% versus 61%; P = 0.04); (ii) prescribed angiotensin-converting enzyme inhibitors (70% versus 60%; P = 0.002) and lipid-lowering agents (77% versus 68%; P = 0.005); (iii) receiving cardiac counselling in hospital (57% versus 48%; P = 0.009); and (iv) referred to cardiac rehabilitation (17% versus 8%; P < 0.001). Conclusions. Multifaceted approaches can improve care processes for patients hospitalized with acute coronary syndromes. Care processes under direct clinician control changed more quickly than those reliant on complex system factors. Identifying and overcoming organizational impediments to quality improvement deserves greater attention.

Role of Diadegma semiclausum (Hymenoptera: Ichneumonidae) in controlling Plutella xylostella (Lepidoptera: Plutellidae): Cage exclusion experiments and direct observation

We evaluated the role of the larval parasitoid, Diadegma semiclausum Hellen (Hymenoptera: Ichneumonidae), in controlling Plutella xylostella (L.) (Lepidoptera: Plutellidae) by cage exclusion experiments and direct field observation during the winter season in southern Queensland, Australia. The cage exclusion experiment involved uncaged, open cage and closed cage treatments. A higher percentage (54-83%) of P. xylostella larvae on sentinel plants were lost in the uncaged treatment than the closed (4-9%) or open cage treatments (11-29%). Of the larvae that remained in the uncaged treatment, 72-94% were parasitized by D. semiclausum , much higher than that in the open cage treatment (8-37% in first trial, and 38-63% in second trial). Direct observations showed a significant aggregation response of the field D. semiclausum populations to high host density plants in an experimental plot and to high host density plots that were artificially set-up near to the parasitoid source fields. The degree of aggregation varied in response to habitat quality of the parasitoid source field and scales of the manipulated host patches. As a result, density-dependence in the pattern of parasitism may depend on the relative degree of aggregation of the parasitoid population at a particular scale. A high degree of aggregation seems to be necessary to generate density-dependent parasitism by D. semiclausum . Integration of the cage exclusion experiment and direct observation demonstrated the active and dominant role of this parasitoid in controlling P. xylostella in the winter season. A biologically based IPM strategy, which incorporates the use of D. semiclausum with Bt, is suggested for the management of P. xylostella in seasons or regions with a mild temperature.

Uncertainty during organizational change: Is it all about control?

Uncertainty is a major source of psychological strain during organizational change. This study tested a model of change-related communication, uncertainty, and control and their relationship with psychological strain, job satisfaction, and turnover intentions. Self-report data were obtained from staff at a psychiatric hospital undergoing restructuring. Results indicated that uncertainty had a direct and an indirect (via feelings of lack of control) relationship with psychological strain. Partialling out common method variance led to a complete mediation of this relationship by control. Other predictions about the relationship of these variables with psychological strain, job satisfaction, and turnover intentions were supported. Implications for future research and practice of change communication are discussed.

The role of the board in firm strategy: Integrating agency and organisational control perspectives

The role of the board of directors in firm strategy has long been the subject of debate. However, research efforts have suffered from several deficiencies: the lack of an overarching theoretical perspective, reliance on proxies for the strategy role rather than a direct measure of it and the lack of quantitative data linking this role to firm financial performance. We propose a new theoretical perspective to explain the board's role in strategy, integrating organisational control and agency theories. We categorise a board's approach to strategy according to two constructs: strategic control and financial control. The extent to which either construct is favoured depends on contextual factors such as board power, environmental uncertainty and information asymmetry.

Hip strategy for balance control in quiet standing is reduced in people with low back pain

Study Design. Quiet stance on supporting bases with different lengths and with different visual inputs were tested in 24 study participants with chronic low back pain (LBP) and 24 matched control subjects. Objectives. To evaluate postural adjustment strategies and visual dependence associated with LBP. Summary of Background Data. Various studies have identified balance impairments in patients with chronic LBP, with many possible causes suggested. Recent evidence indicates that study participants with LBP have impaired trunk muscle control, which may compromise the control of trunk and hip movement during postural adjustments ( e. g., hip strategy). As balance on a short base emphasizes the utilization of the hip strategy for balance control, we hypothesized that patients with LBP might have difficulties standing on short bases. Methods. Subjects stood on either flat surface or short base with different visual inputs. A task was counted as successful if balance was maintained for 70 seconds during bilateral stance and 30 seconds during unilateral stance. The number of successful tasks, horizontal shear force, and center-of-pressure motion were evaluated. Results. The hip strategy was reduced with increased visual dependence in study participants with LBP. The failure rate was more than 4 times that of the controls in the bilateral standing task on short base with eyes closed. Analysis of center-of-pressure motion also showed that they have inability to initiate and control a hip strategy. Conclusions. The inability to control a hip strategy indicates a deficit of postural control and is hypothesized to result from altered muscle control and proprioceptive impairment.

ROR alpha regulates the expression of genes involved in lipid homeostasis in skeletal muscle cells - Caveolin-3 and CPT-1 are direct targets of ROR

The staggerer mice carry a deletion in the RORalpha gene and have a prolonged humoral response, overproduce inflammatory cytokines, and are immunodeficient. Furthermore, the staggerer mice display lowered plasma apoA-I/-II, decreased plasma high density lipoprotein cholesterol and triglycerides, and develop hypo-alpha-lipoproteinemia and atherosclerosis. However, relatively little is known about RORalpha in the context of target tissues, target genes, and lipid homeostasis. For example, RORalpha is abundantly expressed in skeletal muscle, a major mass peripheral tissue that accounts for similar to40% of total body weight and 50% of energy expenditure. This lean tissue is a primary site of glucose disposal and fatty acid oxidation. Consequently, muscle has a significant role in insulin sensitivity, obesity, and the blood-lipid profile. In particular, the role of RORalpha in skeletal muscle metabolism has not been investigated, and the contribution of skeletal muscle to the ROR-/- phenotype has not been resolved. We utilize ectopic dominant negative RORalpha expression in skeletal muscle cells to understand the regulatory role of RORs in this major mass peripheral tissue. Exogenous dominant negative RORalpha expression in skeletal muscle cells represses the endogenous levels of RORalpha and -gamma mRNAs and ROR-dependent gene expression. Moreover, we observed attenuated expression of many genes involved in lipid homeostasis. Furthermore, we show that the muscle carnitine palmitoyltransferase-1 and caveolin-3 promoters are directly regulated by ROR and coactivated by p300 and PGC-1. This study implicates RORs in the control of lipid homeostasis in skeletal muscle. In conclusion, we speculate that ROR agonists would increase fatty acid catabolism in muscle and suggest selective activators of ROR may have therapeutic utility in the treatment of obesity and atherosclerosis.

Direct continuities between cisternae at different levels of the Golgi complex in glucose-stimulated mouse islet beta cells

Direct continuity between the membranes of cisternae in the Golgi complex in mammalian cells rarely has been observed; when seen, its documentation has been equivocal. Here we have used dual-axis electron microscope tomography to examine the architecture of the Golgi in three dimensions at approximate to6-nm resolution in rapidly frozen, freeze-substituted murine cells that make and secrete insulin in response to glucose challenge. Our data show three types of direct connections between Golgi cisternae that are normally distinct from one another. These connections all bypass interceding cisternae. We propose that when pancreatic beta cells are stimulated to synthesize and secrete insulin rapidly in vivo, such connections provide a continuous lumen that facilitates the rapid transit of large amounts of newly made protein for secretion. The heterotypic fusion of cisternae, even transiently, raises important questions about the molecular mechanisms that (i) facilitate the fusion/fission of cisternal membranes and control the directionality and specificity of such events, and (it) retain Golgi processing enzymes at specific places within individual cisternae when two cisternae at different levels in the Golgi have fused, maintaining the sequential processing hierarchy that is a hallmark of Golgi organization.

Job uncertainty and personal control during downsizing: A comparison of survivors and victims

This study developed and tested a model of job uncertainty for survivors and victims of downsizing. Data were collected from three samples of employees in a public hospital, each representing three phases of the downsizing process: immediately before the announcement of the redeployment of staff, during the implementation of the downsizing, and towards the end of the official change programme. As predicted, levels of job uncertainty and personal control had a direct relationship with emotional exhaustion and job satisfaction, In addition, there was evidence to suggest that personal control mediated the relationship between job uncertainty and employee adjustment, a pattern of results that varied across each of the three phases of the change event. From the perspective of the organization's overall climate, it was found that levels of job uncertainty, personal control and job satisfaction improved and/or stabilized over the downsizing process. During the implementation phase, survivors experienced higher levels of personal control than victims, but both groups of employees reported similar levels of job uncertainty. We discuss the implications of our results for strategically managing uncertainty during and after organizational change.

Neuromuscular adaptation during skill acquisition on a two degree-of-freedom target-acquisition task: Isometric torque production

In this study we attempted to identify the principles that govern the changes in neural control that occur during repeated performance of a multiarticular coordination task. Eight participants produced isometric flexion/extension and pronation/supination torques at the radiohumeral joint, either in isolation (e.g., flexion) or in combination (e.g., flexion - supination), to acquire targets presented by a visual display. A cursor superimposed on the display provided feedback of the applied torques. During pre- and postpractice tests, the participants acquired targets in eight directions located either 3.6 cm (20% maximal voluntary contraction [MVC]) or 7.2 cm (40% MVC) from a neutral cursor position. On each of five consecutive days of practice the participants acquired targets located 5.4 cm (30% MVC) from the neutral position. EMG was recorded from eight muscles contributing to torque production about the radiohumeral joint during the pre- and posttests. Target-acquisition time decreased significantly with practice in most target directions and at both target torque levels. These performance improvements were primarily associated with increases in the peak rate of torque development after practice. At a muscular level, these changes were brought about by increases in the rates of recruitment of all agonist muscles. The spatiotemporal organization of muscle synergies was not significantly altered after practice. The observed adaptations appear to lead to performances that are generalizable to actions that require both greater and smaller joint torques than that practiced, and may be successfully recalled after a substantial period without practice. These results suggest that tasks in which performance is improved by increasing the rate of muscle activation, and thus the rate of joint torque development, may benefit in terms of the extent to which acquired levels of performance are maintained over time.

Neuromuscular adaptation during skill acquisition on a two degree-of-freedom target-acquisition task: Dynamic movement

In this experiment, we examined the extent to which the spatiotemporal reorganization of muscle synergies mediates skill acquisition on a two degree-of-freedom (df) target-acquisition task. Eight participants completed five practice sessions on consecutive days. During each session they practiced movements to eight target positions presented by a visual display. The movements required combinations of flexion/extension and pronation/supination of the elbow joint complex. During practice sessions, eight targets displaced 5.4 cm from the start position ( representing joint excursions of 54) were presented 16 times. During pre- and posttests, participants acquired the targets at two distances (3.6 cm [36 degrees] and 7.2 cm [72 degrees]). EMG data were recorded from eight muscles contributing to the movements during the pre- and posttests. Most targets were acquired more rapidly after the practice period. Performance improvements were, in most target directions, accompanied by increases in the smoothness of the movement trajectories. When target acquisition required movement in both dfs, there were also practice-related decreases in the extent to which the trajectories deviated from a direct path to the target. The contribution of monofunctional muscles ( those producing torque in a single df) increased with practice during movements in which they acted as agonists. The activity in bifunctional muscles ( those contributing torque in both dfs) remained at pretest levels in most movements. The results suggest that performance gains were mediated primarily by changes in the spatial organization of muscles synergies. These changes were expressed most prominently in terms of the magnitude of activation of the monofunctional muscles.

Muscle synergies at the elbow in static and oscillating isometric torque tasks with dual degrees of freedom

This study's aim was to identify the effect of oscillation of torques in isometric tasks under identical mechanical conditions on the muscle synergies used. It was hypothesized that bi-functional muscles would play a lesser role in torque oscillation, because they would also generate an undesired oscillation. Thus, changes in muscle synergies were expected as a consequence of oscillation in torque generation. The effect of the trajectory of torque generation was investigated in dual-degrees-of-freedom submaximal isometric oscillation torque tasks at the elbow. The torques were flexion-extension and supination-pronation. Oscillation torques were compared with static torque generations at four torque positions during oscillation. Muscle activity was determined with surface electromyography. Compared with the static torque tasks, the oscillation tasks showed an overall increased muscle activity. The oscillation tasks, however, showed similar activity patterns and muscle synergies compared to the static composite tasks. It was found that the motor system is well able to control different orthogonal combinations of slow torque oscillations and constant torques by employing a single oscillating muscle synergy.

Medial prefrontal cortex control of the Paraventricular hypothalamic nucleus response to psychological stress: Possible role of the bed nucleus of the stria terminalis

The medial prefrontal cortex (mPFC) has been strongly implicated in control of the paraventricular nucleus of the hypothalamus (PVN) response to stress. Because of the paucity of direct projections from the mPFC to the PVN, we sought to investigate possible brain regions that might act as a relay between the two during psychological stress. Bilateral ibotenic acid lesions of the rat mPFC enhanced the number of Fos-immunoreactive cells seen in the PVN after exposure to the psychological stressor, air puff. Altered neuronal recruitment was seen in only one of the candidate relay populations examined, the ventral bed nucleus of the stria terminalis (vBNST). Furthermore, bilateral ibotenic acid lesions of the BNST caused a significant attenuation of the PVN response to air puff. To better characterize the structural relationships between the mPFC and PVN, retrograde tracing studies were conducted examining Fos expression in cells retrogradely labeled with cholera toxin b subunit (CTb) from the PVN and the BNST. Results obtained were consistent with an important role for both the mPFC and BNST in the mpPVN CRF cell response to air puff. We suggest a set of connections whereby a direct PVN projection from the ipsilateral vBNST is involved in the mpPVN response to air puff and this may, in turn, be modulated by an indirect projection from the mPFC to the BNST. (C) 2004 Wiley-Liss, Inc.

Hypothalamic control of bone formation: Distinct actions of leptin and Y2 receptor pathways

Leptin and Y2 receptors on hypothalamic NPY neurons mediate leptin effects on energy homeostasis; however, their interaction in modulating osteoblast activity is not established. Here, direct testing of this possibility indicates distinct mechanisms of action for leptin anti-osteogenic and Y2(-/-) anabolic pathways in modulating bone formation. Introduction: Central enhancement of bone formation by hypothalamic neurons is observed in leptin-deficient oblob and Y2 receptor null mice. Similar elevation in central neuropeptide Y (NPY) expression and effects on osteoblast activity in these two models suggest a shared pathway between leptin and Y2 receptors in the central control of bone physiology. The aim of this study was to test whether the leptin and Y2 receptor pathways regulate bone by the same or distinct mechanisms. Materials and Methods: The interaction of concomitant leptin and Y2 receptor deficiency in controlling bone was examined in Y2(-/-) oblob double mutant mice, to determine whether leptin and Y2 receptor deficiency have additive effects. Interaction between leptin excess and Y2 receptor deletion was examined using recombinant adeno-associated viral vector overproduction of NPY (AAV-NPY) to produce weight gain and thus leptin excess in adult Y2(-/-) mice. Cancellous bone volume and bone cell function were assessed. Results: Osteoblast activity was comparably elevated in oblob, Y2(-/-), and Y2(-/-) oblob mice. However, greater bone resorption in oblob and Y2(-/-) oblob mice reduced cancellous bone volume compared with Y2(-/-). Both wildtype and Y2(-/-) AAV-NPY mice exhibited marked elevation of white adipose tissue accumulation and hence leptin expression, thereby reducing osteoblast activity. Despite this anti-osteogenic leptin effect in the obese AAV-NPY model, osteoblast activity in Y2(-/-) AAV-NPY mice remained significantly greater than in wildtype AAV-NPY mice. Conclusions: This study suggests that NPY is not a key regulator of the leptin-dependent osteoblast activity, because both the leptin-deficient stimulation of bone formation and the excess leptin inhibition of bone formation can occur in the presence of high hypothalamic NPY. The Y2(-/-) pathway acts consistently to stimulate bone formation; in contrast, leptin continues to suppress bone formation as circulating levels increase. As a result, they act increasingly in opposition as obesity becomes more marked. Thus, in the absence of leptin, the cancellous bone response to loss of Y2 receptor and leptin activity can not be distinguished. However, as leptin levels increase to physiological levels, distinct signaling pathways are revealed.

Patient self-efficacy and health locus of control: relationships with health status and arthritis-related expenditure

Objective. To explore the relationship between measures of self-efficacy, health locus of control, health status and direct medical expenditure among community-dwelling subjects with rheumatoid arthritis (RA) and osteoarthritis (OA). Methods. This analysis is part of a larger ongoing study of the costs and outcomes of arthritis and its treatments. Community-dwelling RA and OA respondents completed questionnaires concerning arthritis-related expenditure, health status, arthritis related self-efficacy and health locus of control. Results. Data were obtained from 70 RA respondents and 223 OA respondents. The majority of respondents were female with a mean age of 63 yr for RA respondents and 68 yr for OA respondents. Among the RA respondents, those with higher self-efficacy reported better health status and lower overall costs. Health locus of control was not consistently correlated with health status. OA respondents with higher self-efficacy reported better health status and lower costs. Health locus of control had more influence. OA respondents with higher external locus of control reported worse pain and function. A higher belief in chance as a determinant of health was correlated with more visits to general practitioners and a higher cost to both the respondent and the health system. Conclusion. Higher self-efficacy, which is amenable to change through education programmes, was associated with better health status and lower costs to the respondent and the health system in this cross-sectional study. Locus of control had less of an influence; however, the tendency was for those with higher external locus of control to have higher costs and worse health status. As the measurement of these constructs is simple and the outcome potentially affects health status, these results have implications for future intervention studies to improve quality of life and reduce the financial impact of arthritis on both the health-care system and patients.