Search

The need for security protection in Internet-based healthcare applications is generally acknowledged. Most healthcare applications that use the Internet have at least implemented some kind of encryption. Most applications also enforce user authentication and access control policies, and many audit user actions. However, most fall short on providing strong assurances that the security mechanisms are behaving as expected and that they cannot be subverted. While no system can claim to be totally "bulletproof," PCASSO provides assurance of correct operation through formal, disciplined design and development methodologies, as well as through functional and penetration testing. Through its security mechanisms, backed by strong system assurances, PCASSO is demonstrating "safe" use of public data networks for health care.

Few kinds of technology have had as broad an impact on the recent affairs of humanity as have information technologies. The appearance and rapid spread in the past several years of innovations such as the Internet's World Wide Web and the emergence of computer networks connecting tens to hundreds of millions of people worldwide have occurred with startling rapidity. These global events portend substantial changes in the delivery of health care, the conduct of biomedical research, and the undergraduate, graduate, and continuing education of health professionals. This report will attempt to succinctly review the following: (1) the characteristics of modern information technologies and recent trends that are most relevant to medical education and to the world in which future practitioners, researchers, and educators will live and work; (2) the implications of these technologies for the development of educational goals (in other words, the specific information technology skills that future health professionals will need); (3) the issues associated with the use of these technologies in the process of education; and (4) implications for near-term action by University of California medical schools and academic medical centers.

The ubiquity and ease of use of the Web have made it an increasingly popular medium for communication of health-related information. Web interfaces to commercially available clinical information systems are now available or under development by most major vendors. To the extent that such interfaces involve the use of unprotected operating systems, they are vulnerable to security limitations of Web client software environments. The Patient Centered Access to Secure Systems Online (PCASSO) project extends the protections for person-identifiable health data on Web client computers. PCASSO uses several approaches, including physical protection of authentication information, execution containment, graphical displays, and monitoring the client system for intrusions and co-existing programs that may compromise security.

Patient Centered Access to Secure Systems Online (PCASSO) is a National Information Infrastructure research project funded by the US National Library of Medicine (NLM). PCASSO is specifically designed to address the problem of enabling secure access to health information over the Internet, not just for healthcare providers and medical researchers, but also for patients to view their own medical records. The project is using familiar Web technologies to support the search and retrieval of information, including patient demographics, medications, lab tests, and transcription reports. State-of-the-art security technologies protect patient privacy and the integrity of patient information. This paper describes the security architecture of the PCASSO system.

The Internet's World-Wide Web (WWW) provides an appealing medium for the communication of health related information due to its ease of use and growing popularity. But current technologies for communicating data between WWW clients and servers are systematically vulnerable to certain types of security threats. Prominent among these threats are "Trojan horse" programs running on client workstations, which perform some useful and known function for a user, while breaching security via background functions that are not apparent to the user. The Patient-Centered Access to Secure Systems Online (PCASSO) project of SAIC and UCSD is a research, development and evaluation project to exploit state-of-the-art security and WWW technology for health care. PCASSO is designed to provide secure access to clinical data for healthcare providers and their patients using the Internet. PCASSO will be evaluated for both safety and effectiveness, and may provide a model for secure communications via public data networks.

Health care in the United States has entered a period of economic upheaval. Episodic, fee-for-service care financed by indemnity insurance is being replaced by managed care financed by fixed-price, capitated health plans. The resulting focus on reducing costs, especially in areas where there is competition fueled by oversupply of health services providers and facilities, poses new threats to the livelihood of medical libraries and medical librarians but also offers new opportunities. Internet services, consumer health education, and health services research will grow in importance, and organizational mergers will provide librarians with opportunities to assume new roles within their organizations.

The Information Sources Map (ISM) is a component of the National Library of Medicine's Unified Medical Language System (UMLS) project. The ISM is intended to provide both human-readable and machine-interpretable information about the content, scope, and access conditions for various information sources such as databases, expert systems, and the organizations which make these information sources available. Automated source selection is supported by three types of indexing in the ISM: Medical Subject Heading (MeSH) terms and subheadings; Semantic Types from the UMLS Semantic Network; and Semantic Type Relations, which depict pairs of semantic types joined by a relationship chosen from the Semantic Network. This paper reports a study of the recall and precision of the source selection elements in the prototype version of the ISM.

Since its founding in 1937, the National Cancer Institute (NCI) has supported a substantial program of information dissemination. Two peer-reviewed journals, begun in 1940 and 1959, are supplemented by a congressionally mandated International Cancer Research Data Bank (ICRDB), established in 1972. The NCI has made available online databases of published cancer literature and cancer research in progress for the past decade, using the National Library of Medicine (NLM) MEDLARS system. Recently, a clinical-practice-oriented cancer-information system called Physician Data Query (PDQ) has been developed for access at the NLM, as well as through commercial database vendors. The impact of the NCI information programs is currently under prospective evaluation.

Heretofore, pseudomembranous enterocolitis, or more specifically typhlitis, occurring as a complication of the cytotoxic chemotherapy of acute leukemia has nearly always resulted in a fatal outcome. Recent surgical literature states that if cecitis is found as a consequence of therapy for leukemia, the surgeon should refrain from operating because standard procedures, including hemicolectomy, have not improved survival. This paper reports two patients with acute typhlitis resulting from induction therapy of acute leukemia with cytosine arabinoside and hydroxydaunorubicin. Both patients underwent subtotal colectomy, while their marrows were aplastic from therapy, and survived their surgery. Both are living and well in maintained remission, 1 year from surgery. We review the pathogenesis of this disorder and discuss its clinical, x-ray, and laboratory features. Close oncologic/surgical teamwork is stressed as the patient is followed closely into the time frame when the decision is made whether to operate. Factors contributing to this decision are discussed. Preoperative recommendations are made in order to bring the patient into a state of physiologic stability. The operative procedure is described along with the postoperative complications encountered. We strongly recommend that laparotomy be considered in selected patients with typhlitis occurring as a complication of treated leukemia.

Factor VII clotting activity increases about five-fold when blood is clotted in glass. Prior studies suggested that this results from activation induced by activated factor IX (IXa). However, in purified systems containing phospholipid and calcium, activated factor X (Xa) is known to activate factor VII rapidly. Therefore, we studied activation of factor VII by IXa and X, in systems using purified human factors. Concentrations of IXa and Xa were calculated from total activated protein concentrations rather than from active site concentrations. In the presence of phospolipid and calcium, both IXa and Xa activated factor VII 25-fold; however, Xa was roughly 800 times more efficient than IXa. Without added phospholipid, activation of factor VII by both Xa and IXa was markedly slowed, and Xa was roughly 20 times more efficient than IXa. When both phospholipid and calcium were omitted, activation of factor VII by either enzyme was negligible. Adding normal prothrombin, but not decarboxylated prothrombin, substantially slowed activation of factor VII by both Xa and IXa. Adding thrombin-activated factor VIII and antithrombin-III did not change rates of factor VII activation by either enzyme. These results from purified systems do not provide an explanation for the prior data from plasma systems.

PDQ is an online database that provides information about the prognosis and treatment of all major types of cancer. It represents a major effort by the NCI to communicate advances in cancer treatment using computer technology, and serves as a major component of the Institute's program to reduce cancer mortality nationwide. PDQ utilizes a modern large-scale computer to provide processing speed, a general purpose database management system to provide retrieval and display functions, and commercial telecommunication networks to provide online access to up-to-date information on cancer treatment. A series of user-friendly menus allow searching, browsing, and displaying without having to learn a specialized search language. PDQ is accessible through the National Library of Medicine's computer system via a computer terminal or personal computer and is available to the medical community at over 2000 medical libraries and centers and through individual access codes. PDQ is also available as an online database under a special license agreement with NCI through two medical information systems produced by commercial database vendors: BRS/Saunders' COLLEAGUE and Mead Data Central's MEDIS.