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K Callan

Publications and source records attributed to K Callan.

6 recordsLinked to original sources

Preparing for a decision support system.

The increasing pressure to reduce costs and improve outcomes is driving the health care industry to view information as a competitive advantage. Timely information is required to help reduce inefficiencies and improve patient care. Numerous disparate operational or transactional information systems with inconsistent and often conflicting data are no longer adequate to meet the information needs of integrated care delivery systems and networks in competitive managed care environments. This article reviews decision support system characteristics and describes a process to assess the preparedness of an organization to implement and use decision support systems to achieve a more effective, information-based decision process. Decision support tools included in this article range from reports to data mining.

Decision Support Systems, Management↗

Molecular and biochemical characterization of tomato farnesyl-protein transferase.

The prenylation of membrane-associated proteins involved in the regulation of eukaryotic cell growth and signal transduction is critically important for their subcellular localization and biological activity. In contrast to mammalian cells and yeast, however, the function of protein prenylation in plants is not well understood and only a few prenylated proteins have been identified. We partially purified and characterized farnesyl-protein transferase from tomato (Lycopersicon esculentum, LeFTase) to analyze its biochemical and molecular properties. Using Ras- and G gamma-specific peptide substrates and competition assays we showed that tomato protein extracts have both farnesyl-protein transferase and geranylgeranyl-protein transferase 1 activities. Compared with the heterologous synthetic peptide substrates, the plant-specific CaaX sequence of the ANJ1 protein is a less efficient substrate for LeFTase in vitro. LeFTase activity profiles and LeFTase beta-subunit protein (LeFTB) levels differ significantly in various tissues and are regulated during fruit development. Partially purified LeFTase requires Zn2+ and Mg2+ for enzymatic activity and has an apparent molecular mass of 100 kD Immunoprecipitation experiments using anti-alpha LeFTB antibodies confirmed that LeFTB is a component of LeFTase but not of tomato geranylgeranyl-protein transferase 1. Based on their conserved bio-chemical activities, we expect that prenyltransferases are likely integrated with the sterol biosynthesis pathway in the control of plant cell growth.

Alkyl and Aryl Transferases↗