Sense of place, organizational context and the strategic management of publicly funded hospitals.

An era of managerialism in health care delivery systems is now well ensconced throughout the nations of the OECD. This development has occurred, in large part, as a response to funding pressures in institutionally based health care delivery imposed by principal third party insurers. In the case of publicly funded hospitals, the more traditional concerns for stewardship and appeasement of professional groups is being replaced by a greater emphasis on cost consciousness and corporate-style leadership as these organizations seek to reposition themselves in new funding and regulatory environments. While institutional theory and strategic management perspectives help illuminate these issues, this paper argues that a place-based perspective is also needed to understand the changes currently underway in health care delivery and publicly funded human services more generally. This is illustrated with reference to developments in the strategic management of public hospitals in the province of Ontario. Evidence from a survey of senior administrators of public hospitals, distributed at the height of these policy reform initiatives, is examined to shed light on local level management responses to changing policy and fiscal pressures. The data suggest that the latest policy directions in the province of Ontario will 'encourage' hospital executives in particular community settings to steer their organizations in very unfamiliar directions. The findings suggest a need for greater attention to context and setting in health services research and policy.

Phosphoprotein-protein interactions revealed by the crystal structure of kinase-associated phosphatase in complex with phosphoCDK2.

The CDK-interacting protein phosphatase KAP dephosphorylates phosphoThr-160 (pThr-160) of the CDK2 activation segment, the site of regulatory phosphorylation that is essential for kinase activity. Here we describe the crystal structure of KAP in association with pThr-160-CDK2, representing an example of a protein phosphatase in complex with its intact protein substrate. The major protein interface between the two molecules is formed by the C-terminal lobe of CDK2 and the C-terminal helix of KAP, regions remote from the kinase-activation segment and the KAP catalytic site. The kinase-activation segment interacts with the catalytic site of KAP almost entirely via the phosphate group of pThr-160. This interaction requires that the activation segment is unfolded and drawn away from the kinase molecule, inducing a conformation of CDK2 similar to the activated state observed in the CDK2/cyclin A complex.

Glucose isomerase: insights into protein engineering for increased thermostability.

Thermostable glucose isomerases are desirable for production of 55% fructose syrups at >90 degrees C. Current commercial enzymes operate only at 60 degrees C to produce 45% fructose syrups. Protein engineering to construct more stable enzymes has so far been relatively unsuccessful, so this review focuses on elucidation of the thermal inactivation pathway as a future guide. The primary and tertiary structures of 11 Class 1 and 20 Class 2 enzymes are compared. Within each class the structures are almost identical and sequence differences are few. Structural differences between Class 1 and Class 2 are less than previously surmised. The thermostabilities of Class 1 enzymes are essentially identical, in contrast to previous reports, but in Class 2 they vary widely. In each class, thermal inactivation proceeds via the tetrameric apoenzyme, so metal ion affinity dominates thermostability. In Class 1 enzymes, subunit dissociation is not involved, but there is an irreversible conformational change in the apoenzyme leading to a more thermostable inactive tetramer. This may be linked to reversible conformational changes in the apoenzyme at alkaline pH arising from electrostatic repulsions in the active site, which break a buried Arg-30-Asp-299 salt bridge and bring Arg-30 to the surface. There is a different salt bridge in Class 2 enzymes, which might explain their varying thermostability. Previous protein engineering results are reviewed in light of these insights.

The structure of the protein phosphatase 2A PR65/A subunit reveals the conformation of its 15 tandemly repeated HEAT motifs.

The PR65/A subunit of protein phosphatase 2A serves as a scaffolding molecule to coordinate the assembly of the catalytic subunit and a variable regulatory B subunit, generating functionally diverse heterotrimers. Mutations of the beta isoform of PR65 are associated with lung and colon tumors. The crystal structure of the PR65/Aalpha subunit, at 2.3 A resolution, reveals the conformation of its 15 tandemly repeated HEAT sequences, degenerate motifs of approximately 39 amino acids present in a variety of proteins, including huntingtin and importin beta. Individual motifs are composed of a pair of antiparallel alpha helices that assemble in a mainly linear, repetitive fashion to form an elongated molecule characterized by a double layer of alpha helices. Left-handed rotations at three interrepeat interfaces generate a novel left-hand superhelical conformation. The protein interaction interface is formed from the intrarepeat turns that are aligned to form a continuous ridge.

Purification and crystallization of the CDK-associated protein phosphatase KAP expressed in Escherichia coli.

The kinase associated phosphatase (KAP) is a human dual specificity protein phosphatase that dephosphorylates the cell cycle control protein, cyclin dependent kinase-2 on Thr 160 in a cyclin dependent manner (Poon & Hunter, 1995). We report here the over-expression of KAP in Escherichia coli as an N-terminal His-tagged protein using a modified pET-28a T7-expression vector. The recombinant protein was purified to homogeneity and crystallized. The crystals diffract to 2.3 A resolution when exposed to synchrotron radiation and belong to space group P6(1)22, or its enantiomorph P6(5)22, with unit cell dimensions a = b = 74.5 A, c = 139.5 A.

Access and utilization: a continuum of health service environments.

Birch and Abelson [1] argue that non-income based barriers might explain differences in utilization of health services within and between income groups. Databases which contain utilization data rarely allow for the modelling of geographic variation. In the Ontario Health Survey (OHS), individual observations are georeferenced at the Public Health Unit (PHU) scale, but PHUs cannot easily be used because of the large coefficients of variation. To overcome this problem, a cluster analysis is performed to create a service environment variable, which reflects differences in service availability, population size and rurality. Utilization of health services is then modelled as a logistic regression equation where the independent variables are age, sex, service environment and income to test the Birch and Abelson argument. This argument is then extended by controlling for age, health and income status. Based on the modelling results, the importance of geography to access and utilization is assessed.