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Biomedical subjects

D W MacPherson

Publications and source records attributed to D W MacPherson.

27 records · Page 2Linked to original sources
PubMed1994

Morphological diversity of Blastocystis hominis in sodium acetate-acetic acid-formalin-preserved stool samples stained with iron hematoxylin.

The objective of this investigation was to study the morphological characteristics of Blastocystis hominis in sodium acetate-acetic acid-Formalin-preserved stool samples. Routinely processed samples were examined for morphological detail, including size, shape, nuclear detail, and central body characteristics. Morphological findings revealing the importance of recognizing B. hominis in the diagnostic laboratory are described.

Animals↗
PubMed1993

Cryptosporidiosis: multiattribute evaluation of six diagnostic methods.

Six diagnostic methods (Giemsa staining, Ziehl-Neelsen staining, auramine-rhodamine staining, Sheather's sugar flotation, an indirect immunofluorescence procedure, and a modified concentration-sugar flotation method) for the detection of Cryptosporidium spp. in stool specimens were compared on the following attributes: diagnostic yield, cost to perform each test, ease of handling, and ability to process large numbers of specimens for screening purposes by batching. A rank ordering from least desirable to most desirable was then established for each method by using the study attributes. The process of decision analysis with respect to the laboratory diagnosis of cryptosporidiosis is discussed through the application of multiattribute utility theory to the rank ordering of the study criteria. Within a specific health care setting, a diagnostic facility will be able to calculate its own utility scores for our study attributes. Multiattribute evaluation and analysis are potentially powerful tools in the allocation of resources in the laboratory.

Adult↗
PubMed1993

Ethical concerns in HIV testing.

I conducted a retrospective chart review of all HIV antibody test requests received in the laboratory of a community hospital. Despite guidelines calling for pre-test counseling and informed consent, only one test request noted patient consent. Less than 40% documented a physician's order. This article reviews guidelines and suggests ways to improve practice.

AIDS Serodiagnosis↗
PubMed1993

Testing for HIV antibodies. Guide for obtaining informed consent.

Testing for HIV and such issues as test accuracy, informed consent, reporting requirements, and confidentiality related to testing are reviewed. Pre-test and posttest counseling is discussed, and a sample form to guide family physicians in obtaining informed consent is provided.

AIDS Serodiagnosis↗
PubMed1992

Cholera vaccination: a decision analysis.

OBJECTIVE: To examine the clinical impact and financial cost of a vaccination program for the prevention of cholera in North Americans travelling to endemic and epidemic regions by means of the principles of decision analysis and a decision tree as well as to illustrate the effect of case attack rates on the cost per case prevented by vaccination. DESIGN: Review of the scientific literature to establish the probabilities of each significant outcome as well as a decision analysis and partial economic evaluation. OUTCOME MEASURES: Clinical impact (attack rates for cholera among vaccinated and nonvaccinated travellers), rates of death associated with cholera and vaccine-associated adverse events (VAAEs), and the number of VAAEs and the vaccine cost per case prevented. MAIN RESULTS: On the basis of our assumptions (including a rate of one case of cholera per 500,000 journeys to endemic regions), to prevent one case of cholera a vaccination program would cost $28.67 million and be associated with 105 VAAEs. CONCLUSION: Routine vaccination of travellers to endemic areas cannot be recommended; however, for people travelling to regions with a high transmission rate vaccination should be considered.

Cholera↗
PubMed1986

Inability of the Chemstrip LN compared with quantitative urine culture to predict significant bacteriuria.

The Chemstrip LN (Boehringer Mannheim Biochemicals, Indianapolis, Ind.), designed to detect pyuria and bacteriuria, was compared with culture of 1,020 unselected, consecutive midstream urine specimens and evaluated on its ability to predict colony counts at three levels. At the level of greater than or equal to 10(5) CFU/ml, the combined test (detection of leukocyte esterase and nitrite) had sensitivity of 82.3%, specificity of 67.9%, positive predictive value of 41.3%, and negative predictive value of 93.3% at prevalence rate of 21.6%. The test would have rejected 9.4% of the specimens with significant bacteriuria if the Chemstrip alone had been used.

Bacteria↗
PubMedDate not supplied

Arrest and detention in international travelers.

BACKGROUND: Our objective was to examine the characteristics of international travelers from Canada who have been arrested or detained while abroad, and to review the health implications of incarceration. METHOD: An EpiInfo 6 program was created to analyse all of the Consular reports received in 1995 via the Secure Integrated Global Network (SIGNET) which provides communications and computerization services to the Department of Foreign Affairs and International Trade, Canada. The Consular Management and Operations System was designed to support the delivery of consular services by the Department, and to link Headquarters in Ottawa with missions in other countries through case management files, including a "Prisoners" file. Information obtained included personal demographics (age, gender), date, country, and reason for arrest or detention, and outcome of judicial process. RESULTS: There were 1, 086 arrest or detention reports received from Consular services via SIGNET in 1995. Males outnumbered females 5.6:1. Most individuals arrested were young: 57.5% were less than 40 years, and 79% were less than 50 years. Drug related charges were cited in 33.1% of all cases, with 52.8% of arrested females charged with drug related offenses. The documented conviction rate was 96%. The majority of detained Canadian travelers were held in countries within the Americas (791 cases - 69.2%), with 642 (59.1%) being detained in the USA. CONCLUSIONS: Arrest and detention is an unusual occurrence for international travelers but relative youth, male gender, and female drug couriers were identifiable risk characteristics. Public awareness campaigns can be targeted to specific population demographics, but all international travelers need to be counseled on the consequences of transgressing laws in foreign countries.

Adolescent↗
PubMedDate not supplied

Death and dying abroad: the Canadian experience.

BACKGROUND: The objective was to examine the characteristics of international travelers from Canada, who have died while abroad, and to review the health protection and promotion strategies for prevention of adverse health outcomes associated with travel, which may have prevented these deaths. METHOD: An EpiInfo 6 program was created to analyse all of the Consular reports received in 1995 via the Secure Integrated Global Network, which provides communications and computerization services to the Department of Foreign Affairs and International Trade, Canada. The Consular Management and Operations System was designed to support the delivery of consular services by the Department, and to link Headquarters in Ottawa with missions in other countries, through case management files, including a "Death Abroad" file. The type of data collected included personal demographics (age, gender), date, country, and cause of death. RESULTS: In 1995, consular services received 309 reports of Canadians dying abroad. Two hundred and twenty deaths were males (71.2%), and 69 were females (22.3%). The average age (56 years) and median age (43 years) were similar for males and females (age range 0.3-86 years). Recorded causes of death were: natural (62.1%), accidents (24.9%), murder (7.8%), and suicide (5.2%). Cardiovascular disease and trauma were the two most commonly specified causes of death. CONCLUSIONS: At least 36% of the deaths occurring in Canadian travelers would be considered preventable. Pretravel medical interventions for travelers with known preexisting medical problems, may have prevented many more deaths. International travelers need to be aware of the health risks associated with travel. Access to appropriate health risk assessment, prior to exposure, in many cases, would have prevented death abroad.

Adolescent↗