Search PubMed⌕ Search

Biomedical subjects

W W Stead

Publications and source records attributed to W W Stead.

At least 37 records · Page 2Linked to original sources
PubMed1996

Strand displacement amplification and the polymerase chain reaction for monitoring response to treatment in patients with pulmonary tuberculosis.

Specific amplification of Mycobacterium tuberculosis DNA was investigated as an alternative to conventional microbiologic follow-up in 31 cases of smear- and culture-positive pulmonary tuberculosis. Strand displacement amplification (SDA) and the polymerase chain reaction (PCR) were applied to 438 sequential sputum specimens: 67 (15%) were positive by culture, 248 (57%) by SDA, and 231 (53%) by PCR (chi2=3.94, P=.05). Of 200 specimens collected >180 days after treatment started, none yielded positive cultures, while 50 (25%), representing 16 patients, were positive by both DNA assays. A weak correlation was demonstrated between DNA persistence in sputum and duration of culture positivity (r=0.45, P=.01), although no correlation was found with the radiographic extent of disease. The inability to distinguish live and dead organisms precludes DNA amplification from use in therapeutic monitoring. For this purpose, quantitative RNA assays are needed if such techniques are to supplant conventional microbiology.

Base Sequence↗
PubMed1996

Integrating health sciences librarians into biomedicine.

Vanderbilt University Medical Center (VUMC) developed a model training program to prepare current and future health sciences librarians for roles that are integrated into the diverse fabric of the health care professions. As a complement to the traditional and theoretical aspects of a librarian's education, this mixture of supplemental coursework and intensive practical training emphasizes active management of information, problem-solving skills, learning in context, and direct participation in research, while providing the opportunity for advanced academic pursuits. The practical training will take place under the auspices of an established Integrated Advanced Information Management Systems (IAIMS) library that is fully integrated with the Health Center Information Management Unit and Academic Biomedical Informatics Unit. During the planning phase, investigators are analyzing the model's aims and requirements, concentrating on (a) refining the current understanding of the roles health sciences librarians occupy; (b) developing educational strategies that prepare librarians to fulfill expanded roles; and (c) planning for an evaluation process that will support iterative revision and refinement of the model.

Certification↗
PubMed1995

Management of health care workers after inadvertent exposure to tuberculosis: a guide for the use of preventive therapy.

OBJECTIVE: To quantify the protection of previously infected persons from developing tuberculosis after intense exposure. SETTING: 6 hospitals and 22 nursing homes in which heavy tuberculosis exposure had occurred. MEASUREMENTS: Results of tuberculin skin tests before and after exposure and the development of tuberculosis among known reactors, both converters and nonconverters. INTERVENTION: All converters were given preventive therapy with isoniazid as soon as they could be identified. Nonconverters and previously known reactors were not treated. RESULTS: In 6 hospital outbreaks, largely aborted by prompt preventive therapy, 98 of 336 nonreactors (29%) showed skin test conversion, and, before therapy could be started, 19 (19% [95% CI, 12% to 29%]) had developed tuberculosis. No tuberculosis developed among the 238 nonconverters (0% [CI, 0% to 1.5%]) or the 76 known reactors who were not treated (0% [CI, 0.5% to 2%]). Tuberculosis developed in 5 of 209 known reactors (2.4% [CI, 0.8% to 5.5%]) in 22 nursing homes with heavy exposure, little more than 10 of 921 known reactors (1.1% [CI, 0.5% to 2%]) in 76 homes where there was no exposure (P = 0.17). CONCLUSIONS: Healthy persons who remain nonreactive to tuberculin after heavy exposure have escaped infection and require no chemotherapy. However, if exposure is discovered immediately, it is wise to start preventive therapy in particularly heavily exposed non-reactors and discontinue it if the skin test result is still negative at 3 months. Persons who react after exposure fall into three groups: 1) converters, in whom the risk for tuberculosis warrants preventive chemotherapy, regardless of age; 2) reactors with no preexposure test results, who should be treated as converters; and 3) previously known reactors, in whom the risk for tuberculosis generally is too slight to warrant therapy. However, those who are younger than age 35 years, have human immunodeficiency virus infection, are receiving cancer chemotherapy or long-term corticosteroid therapy, or are otherwise immunocompromised should be considered for preventive therapy, regardless of the exposure.

Clinical Protocols↗
PubMed1995

The risk for transmission of Mycobacterium tuberculosis at the bedside and during autopsy.

OBJECTIVE: To emphasize the differing infectious potentials of a patient with tuberculosis. SETTING: Hospital ward and autopsy room. DESIGN: An epidemiologic investigation of tuberculin skin test conversions in a clinical setting and during autopsy when results of tuberculin tests done before exposure were available for all participants. MEASUREMENTS: Tuberculin skin test results after the discovery of tuberculosis exposure from a patient with unsuspected tuberculosis for comparison with the test results before exposure; culture of sputum and autopsy material for Mycobacterium tuberculosis; and DNA fingerprinting of organisms. INTERVENTION: Preventive therapy for persons with skin test conversion. RESULTS: None of the 40 skin test-negative health care workers caring for the patient for 3 weeks on an open medical ward showed a skin test conversion, even though they had not used respiratory precautions. By contrast, among personnel present during the 3-hour autopsy, the test results of all five nonreactors converted from negative to positive (mean reaction, 24 mm). Two of these persons had a positive sputum culture 8 weeks later. The DNA fingerprints of all three isolates were identical. CONCLUSIONS: A patient who did not transmit tuberculosis before death released a prodigious number of tubercle bacilli during autopsy.

Air Microbiology↗
PubMed1995

Building a data foundation for tomorrow's healthcare information management systems.

Accurate, timely data are a necessary foundation for an effective healthcare information management system. Today's systems do not achieve their potential because they lack this essential ingredient. Technology can reduce the problem by making the data entry task easier, but a complete solution will require new strategies for system implementation and use. Functions must be implemented in a sequence that allows the initial functions to establish a data foundation for subsequent functions. Each atomic data item must be collected separately, with a consistent definition. Data capture strategies must permit data to be collected once, at the source. Finally, the data must be used, reused, and corrected by all members of the healthcare team.

Decision Making, Computer-Assisted↗
PubMed1995

Strategic planning for information management: what are the deliverables?

This paper describes the deliverables framework developed by Vanderbilt University Medical Center (VUMC) in its IAIMS planning process. The key deliverables include: visions for the future; mission, goals, and objectives for the information management function; critical functions for IAIMS; categorized projects; priority recommendations; and a straw man project sequence reflecting dependencies. The paper also discusses how the plan will be used and how it interacts with direction-setting for the Medical Center.

Academic Medical Centers↗
PubMed1994

Smear-negative pulmonary tuberculosis.

Diagnostic difficulties arise when sputum smears are negative for acid-fast bacilli in tuberculin-positive patients with compatible symptoms and chest radiographs for tuberculosis. Many of these smear-negative patients yield positive cultures for M tuberculosis, whereas others remain culturally negative. Several studies have shown that many smear-negative/culture-negative patients will develop bacteriologically positive disease later. Often, physicians are unable to decide whether to initiate chemotherapy or to wait for the culture results. Also, if treatment is initiated in smear negative patients, what should be the drug regimen and duration of therapy. A positive smear signifies a very large bacterial population in the lung lesions whereas several negative smears suggest a smaller bacterial load. Such smear-negative cases do not require the same intensity and duration of treatment as smear-positive cases. Therapy should be initiated for tuberculosis after other causes for abnormal chest x-ray have been excluded. However, duration of therapy may be shortened in these cases. The British Medical Research Council (BMRC) study has shown that intensive treatment of smear-negative/culture-positive disease with streptomycin (SM), isoniazid (INH), rifampin (RIF), and pyrazinamide (PZA) for 4 months was uniformly successful. This regimen is routinely recommended in Hong Kong. Because primary drug resistance is low (< 3%) in Arkansas, we treated these cases with INH and RIF for 6 months with good results. This is now a routine drug regimen. For smear-negative/culture-negative cases, the BMRC study has shown that daily or thrice weekly treatment with SM, INH, RIF, and PZA for 4 months is effective.(ABSTRACT TRUNCATED AT 250 WORDS)

Antitubercular Agents↗
PubMed1993

The history of tuberculosis as a global epidemic.

TB should be thought of as a slowly progressing worldwide epidemic. Initially it was a disease of lower mammals, and the etiologic agent probably preceded the development of man on earth. It became an uncommon endemic disease in man about the time man began to settle in villages and develop agriculture. Crowding in European cities, and later the industrial revolution in Europe, provided the necessary environmental conditions for the endemic disease to become epidemic. For the next 400 years, the disease was spread by European empire-building and colonization. It came late to sub-Saharan Africa and to the Pacific Islands, and still later to the highlands of New Guinea. The epidemic gradually wanes within a large population group as resistant individuals survive and reproduce. This natural resistance is reflected in the ability of the macrophage to control intracellular growth of the organism. The resistant host shows a chronic infection primarily affecting the lungs, whereas the highly susceptible host shows a rapidly fatal illness with generalized spread of disease to many organs. Survivors of the initial infection then show another type of resistance to reinfection that is based on sensitized T cells. When this system is only partially successful, the host becomes infectious and capable of spreading the infection widely. The study of the epidemiology of TB and the evaluation of various public health measures to prevent or contain the disease requires that the investigator have an understanding of the nature and duration of the TB epidemic in the particular population under study. This factor is a much greater determinant of the course of an epidemic than any public health measure that man can institute, just as the currents in a river can have a more powerful effect on the course of a canoe than the most vigorous paddler.

Disease Outbreaks↗
PubMed1993

Tuberculosis in the elderly.

Elderly persons of today are survivors of a time when most adults were infected with tuberculosis. Although many people died at that time, others survived the initial infection but continued to harbor viable bacilli in dormant caseous and calcified lesions. This article discusses the tuberculin test in the elderly, transmission and risk of infection in nursing homes, clinical manifestations, diagnosis, management considerations, preventive therapy, and surveillance of tuberculosis in nursing homes.

Aged↗
PubMed1993

Building an information management infrastructure in the 90s: the Vanderbilt experiment.

The course that an organization takes to create a competitive information management infrastructure is determined by a series of decisions, each of which balances tradeoffs. Key success factors include sequencing projects to reflect data requirements; obtaining benefits as cost is incurred; establishing an architecture that permits integration of applications; managing project scope; and establishing a data friendly culture.

Academic Medical Centers↗
PubMed1993

A planning process for a fast track to IAIMS.

The strategic planning process that is part of Vanderbilt University's fast track to IAIMS is evolving based on feedback from the process itself. Led by a committee of VUMC's top management, broad-based sub-committees for administration, education, patient care, and research worked initially on the following strategic issues: identifying key external pressures that constrain and provide opportunities, visioning how VUMC might operate in the future, and establishing a mission and high-level goals for information management. Next steps include identifying the critical mass of function that will prompt daily use of the IAIMS by everyone at VUMC and adding groups to focus on information and technology architectures and developing academic informatics. This manuscript gives detailed, practical information about the evolution of the planning process, committees' responsibilities, working relationships, and lessons learned.

Academic Medical Centers↗