Costs and benefits of connecting community physicians to a hospital WAN.

The Washington Heights-Inwood Community Health Management Information System (WHICHIS) at the Columbia-Presbyterian Medical Center (CPMC) provides 15 community physician practices with seamless networking to the CPMC Wide-Area Network. The costs and benefits of the project were evaluated. Installation costs, including hardware, office management software, cabling, network routers, ISDN connection and personnel time, averaged $22,902 per office. Maintenance and support costs averaged $6,293 per office per year. These costs represent a "best-case" scenario after a several year learning curve. Participating physicians were interviewed to assess the impact of the project. Access to the CPMC Clinical Information System (CIS) was used by 87%. Other resource usage was: non-CPMC Web-based resources, 80%; computer billing, 73%; Medline and drug information databases, 67%; and, electronic mail, 60%. The most valued feature of the system was access to the CPMC CIS. The second most important was the automatic connection provided by routed ISDN. Frequency of access to the CIS averaged 6.67 days/month. Physicians reported that the system had significantly improved their practice of medicine. We are currently exploring less expensive options to provide this functionality.

Encoding a post-operative coronary artery bypass surgery care plan in the Arden Syntax.

The Arden Syntax for medical logic modules (Arden) was used to test the feasibility of encoding large, complex care plans. The critical portions of an existing paper-based care plan for the management of patients following coronary artery bypass graft (CABG) surgery were encoded in Arden and an X-windows user-interface was developed. The Arden Syntax proved adequate for encoding all of the necessary functions of the care plan. The limitations of the current Arden Syntax and possible additions to Arden are discussed.

Three-dimensional display of positron emission tomography of the heart.

A method for producing images of 82Rb myocardial perfusion and 11C carbon monoxide gated blood pool images is described. In the case of 82Rb images, cylindrical projection displaying myocardial activity as viewed from the side is presented to complement the polar projection. Cubic display of the conventional short- and long-axis slices is described that permits interactive selection of any desired slices. A three-dimensional cine display of the left ventricle rotating about its long axis is produced that gives a very realistic presentation of myocardial activity. Very similar processing techniques are applied to gated carbon-11 blood-pool studies to yield beating images of the surface of the blood pool in multiple projections.

Ir gene-controlled response to haptenated hen ovomucoid: isotypic specificity and dominant nonresponsiveness.

We have examined the isotypic pattern of the response of mice to the Ir gene-controlled antigen, dinitrophenyl-ovomucoid (DNP-OM). H-2 kappa mice are high responders (HR); (H-2b,d mice are low responders (LR). The isotype patterns of HR and LR strains differ both quantitatively and qualitatively. In the primary response to doses of 20-100 micrograms DNP-OM, HR strains produce IgM and IgG antibodies, whereas LR strains produce only IgM. Background genes modify the kinetics of the IgGl primary response in HR strains, but no background was found which allowed an IgG response in a LR strain. In secondary responses, priming with 0.2 microgram DNP-OM increases secondary responses in HR strains, and decreases them in LR strains. Control of this response maps to I-A, and is not altered by the bm 12 I-Ab mutation. The LR phenotype is dominant in (HR X LR)F1 mice.