Arizona Telemedicine Program: implementing a statewide health care network.

The Arizona Telemedicine Program was established in July 1996 by the Arizona state legislature. The organizational center for the program is the Arizona Health Sciences Center in Tucson. Key goals for the program include increased access to specialty services for rural, underserved populations; development of cost-effective telemedicine services; and expansion of opportunities for education of health professionals in rural areas. The program provides several levels of services based on both store-and-forward and real-time interactive applications. The telecommunication infrastructures is provided by two methods: The first is a private asynchronous transfer mode network established and operated by program personnel. The second is dial-up access via the public switched telephone network. After an extensive period of organization and vendor evaluations, most of the private network was implemented between June and December 1997. This paper describes experiences establishing the asynchronous transfer mode network.

Gametocyte production in cloned lines of Plasmodium falciparum.

Gametocyte production by cloned lines of Plasmodium falciparum and their parental isolates has been studied in culture over periods of several months. Many isolates differed significantly from each other in their capacity for gametocyte production. Clones derived from an individual isolate were also widely different in capacity for gametocyte production. Consistent differences in gametocyte production were observed between clones which had always been grown concurrently and thus had identical culture histories. Levels of gametocytogenesis characteristic of individual clones, although subject to transient fluctuations under environmental influence, were stable over several months.

Evaluation of the ACR-NEMA standard for communications in digital radiology.

An implementation and evaluation of a prototype multivendor communications system which complies with the American College of Radiology (ACR) and the National Electrical Manufacturers Association (NEMA) standard for communications in digital radiology is discussed. The system allows communications between interfaces from different manufacturers within a networked environment. The implementation includes network software compatible with the International Standards Organization's Open Systems Interconnect standard. The experience of the implementation effort and the evaluation of the system provide the basis for a critique of the ACR-NEMA standard. It is concluded that the ACR-NEMA standard is not well suited for application to the networked environment of picture archiving and communications systems. Two possible solutions are recommended for this problem. The first is a major revision of the existing standard. The second is the development of a family of network communications standards for digital radiology.

Standardization of network addressing in picture archiving and communications systems utilizing the ISO OSI protocols.

The establishment of a communications network requires the definition of addressing schemes to identify systems attached to the network. When it is anticipated that such a network will interconnect to, or communicate with, other similar networks it is beneficial to define standardized addressing schemes. This paper discusses the need for the standardization of network service access point (NSAP) addresses in picture archiving and communications systems (PACS) which use the open systems interconnect (OSI) communications protocols. Possible methods for establishing the necessary hierarchy of address registration authorities are discussed, along with the corresponding address formats.

The operational impact of architectural alternatives for radiological imaging workstations.

Characteristics of workstations for use in digital radiological imaging have been investigated for many years. However, much of this investigation has focused on the workstation in isolation, and has often been directed almost entirely at user interface issues. Certainly these issues are critical, but with the increasing use of commercial workstations it is important to look at the workstation in the context of the medical information environment and examine some important underlying characteristics required to meet the demands of digital radiology. This article examines the role of storage components in these workstations both architecturally and operationally. Both aspects are viewed with consideration of their impact on the internals of the workstation and its interaction with the external information system. By considering these aspects of the workstation it is apparent that local storage and image preloading are required to support diagnostic viewing. Additional operational and architectural strategies are required to efficiently manage information within the workstation.

Bacterial endocarditis: an analysis of factors affecting long-term survival.

The records of 108 patients treated for bacterial endocarditis were reviewed. Six were diagnosed at autopsy and had not been treated for endocarditis. Of the 102 treated patients, 32 died during the first 30 days and 32 more were dead by 365 days. Although some reports indicate a much greater survival rate, our findings are more in keeping with those reports giving a rather poor long-term outlook for patients with endocarditis.

Digital distribution of chest radiographs to intensive care units.

This paper describes the implementation of the Medical Image Access System for Intensive Care Units (MIAS/ICU). MIAS/ICU is a distributed computer system that integrates the collection of computed radiography images with information from the Hospital Information System (HIS) to allow caregivers in two Intensive Care Units (ICUs) at University Medical Center (Tucson, AZ, USA) to view digital chest radiographs on dual-monitor workstations within minutes of the time the exposures are made. The system uses entirely "off-the-shelf" hardware components and software based on widely followed standards. MIAS/ICU is based on an innovative modular software architecture that allows simple incremental expansion of the system, along with enhanced portability among platforms.

Epidemic spread of adenovirus type 4-associated acute respiratory disease between U.S. Army installations.

A large outbreak of adenovirus type 4-associated acute respiratory disease (ARD) occurred at Fort Jackson, South Carolina, in 1997. A laboratory-based ARD surveillance program was initiated at Fort Gordon, Georgia, where advanced individual training was heavily populated with Fort Jackson soldiers. Adenovirus type 4 was isolated from 50% of 147 trainees hospitalized with ARD. Most (88%) introduced cases were in trainees from Fort Jackson.

Splenomegaly in Baringo District, Kenya, an area endemic for visceral leishmaniasis and malaria.

The relationship between splenomegaly and visceral leishmaniasis (VL) was investigated during a cross-sectional study in 2,941 individuals in Baringo District, Kenya, where both malaria and VL are endemic. Spleen size was correlated with presence of malaria parasites in thick blood films and with evidence of present or past Leishmania donovani infection as determined by serology and history. Marked splenomegaly (Hackett grade 3 or greater) significantly correlated with present or previous leishmanial infection (chi 2 = 53.5; p < 0.001) whereas moderate splenomegaly (Hackett grade 1 or 2) significantly correlated with malaria parasitaemia (chi 2 = 73.03; p < 0.001). The presence of antimalarial antibodies did not contribute to the differentiation of the cause of splenomegaly. The diagnostic significance of splenomegaly in this population is discussed.

An efficacy trial of doxycycline chemoprophylaxis against leptospirosis.

Because leptospirosis has been an important cause of morbidity in U.S. soldiers training in the Republic of Panama, we conducted a randomized, double-blind, placebo-controlled field trial during the fall of 1982 to determine whether doxycycline was an effective chemoprophylactic agent against this infection. Doxycycline (200 mg) or placebo was administered orally on a weekly basis and at the completion of training to 940 volunteers from two U.S. Army units deployed in Panama for approximately three weeks of jungle training. Twenty cases of leptospirosis occurred in the placebo group (an attack rate of 4.2 per cent), as compared with only one case in the doxycycline group (attack rate, 0.2 per cent, P less than 0.001), yielding an efficacy of 95.0 per cent. This study demonstrated the value of doxycycline as a prophylactic drug against leptospirosis.