Search PubMed⌕ Search

Biomedical subjects

J Cairns

Publications and source records attributed to J Cairns.

At least 55 records · Page 3Linked to original sources
PubMed1996

Sudden unexplained death in Asian immigrants: recognition of a syndrome in metropolitan Toronto.

OBJECTIVE: To determine the number of Southeast Asians in Ontario who died of the sudden unexplained death syndrome in Asian immigrants. DESIGN: Retrospective review. SETTING: Ontario. CASES: All deaths reported to the Office of the Chief Coroner for Ontario from 1992 to 1995. OUTCOME MEASURES: Age, residence and country of origin of people who died of sudden unexplained death syndrome in Asian immigrants, as defined by standard criteria, autopsy findings and social history of cases. RESULTS: Eight cases of sudden unexplained death in Asian immigrants were reported during the study period. All involved men, and the mean age at death was 34 (standard error of the mean 7) years (range 23 to 44 years). All of the people were residents of metropolitan Toronto. Four were from Vietnam, three from China and one from the Philippines. Seven people lived with family members; the eighth was unemployed and lived alone. Death occurred during sleep or in the waking hours of the morning in six cases; in two of these cases the person's spouse was awakened by loud, laboured breathing. Two men experienced chest pain, and one of them also had sudden-onset dyspnea. There was no prodromal illness in any case. The only consistent autopsy finding was acute nonspecific pulmonary edema and congestion. Analysis of heart weights failed to reveal signs of significant cardiomegaly. CONCLUSION: Men from Southeast Asia aged 20 to 45 years are at risk of sudden unexplained death, which usually occurs during sleep. No specific factors have been found that could be used to identify people at risk.

Adult↗
PubMed1996

Toxicity testing with communities: microcosms, mesocosms, and whole-system manipulations.

Present ecotoxicological methodology is not adequate for providing evidence for decisions on sustainable use of the planet, maintenance of ecosystem services, or ecosystem health. However, particularly in the area of ecosystem health, promising beginnings have been made. Presumably, if ecosystems are maintained in robust health, then sustainability and reliable delivery of ecosystem services should result. On the other hand, one cannot ignore either human population size or expectations of affluence. Whether the number of ecosystems in robust health will be adequate for appropriate delivery of ecosystem services not only for existing generations but for future generations still has very unacceptably high levels of uncertainty. All ecosystems are dynamic, and one of the problems will be distinguishing normal cyclical or successional changes from trends away from established norms. Furthermore, toxicity tests are extremely useful for determining deleterious effects and those concentrations at which no-observable-deleterious effects occur. They are not suitable for determining how successfully various materials are being reincorporated into natural systems without disturbing ecological integrity. In a very real sense, however, this is a toxicological problem because, like vitamins and other essential materials for humans, excessive amounts of at least some types can be deleterious as can other materials such as ordinary table salt. It seems inevitable that different criteria, standards, endpoints, and methodologies that revolve around sustainability, ecosystem services, and reincorporating extracted and manufactured materials into natural systems following their use by human society will be required. Furthermore, ecosystems are different, both structurally and functionally, in different climatic zones, different altitudes, different soil conditions, and the like. Therefore, widespread uniform standards seem unlikely to function well, particularly for toxic materials. Prescriptive legislation, as opposed to that requiring site-specific professional judgment, is not likely to serve well under these circumstances. How success will be determined, how deleterious effects will be supported by evidence, and how effective extrapolations from one system to another will be are just a few of the many questions that need resolution. Finally, both temporal and spatial scales of systems under examination must increase, as will the diversity of information used as a basis for professional judgment. All of these factors are occurring in other areas of human societies, increasing globalization, and entry into the information age. Thus, the trends for ecotoxicology are in many ways quite similar to those in other professions as well.

Animals↗
PubMed1996

Evaluating the benefits of antenatal screening: an alternative approach.

This paper presents an alternative method of valuing the benefits of antenatal screening programmes based on individual preferences. The methods of benefit measurement used to date, namely averted costs, QALYs, and willingness to pay, are critically reviewed. The alternative method assumes that screening can be regarded as an investment in improved information, and that the benefits of screening can be measured by the value placed upon this information. The information is valued by presenting individuals with standard gamble questions framed in terms of a prenatal diagnostic choice. The approach is developed in the context of antenatal screening for Down's syndrome and for cystic fibrosis carrier status. Some empirical testing of the approach is reported for the latter.

Cost-Benefit Analysis↗
PubMed1996

The modification of human society by natural systems: discontinuities caused by the exploitation of endemic species and the introduction of exotics.

Drastic reductions in Earth's biodiversity, old growth forests, top soil, clean water and air, and truly wild areas are occurring during a period when discussions of sustainable growth and sustainable production are becoming common. Using such terms as sustainable growth and sustainable production rather than the more accurate sustainable use of the planet leaves the impression that, with a little more skill, society can continue its present practices indefinitely. A number of explanations are possible for this desire to maintain two conflicting beliefs (i.e., severe environmental destruction occurs but society can continue its basic practices indefinitely): 1) the idea that a technological solution can be found for every problem; 2) an addiction to present behavioral norms, which is so strong that the consequences of continuing such behavior are irrelevant; and 3) the concept that, while human society can alter natural systems to suit its own needs, natural systems are incapable of altering human society. This last issue is the focus of this discussion: if human society eliminates all species on the planet that are incapable of tolerating human society's present practices, the only species remaining will be those that human society is unable to control successfully or eliminate; these species are called pests. Another hypothesis could be stated: a world of pests that human society cannot control effectively will inevitably reshape human society through disease and famine, technological breakdown, and interference with domesticated and wild species upon which the integrity of human societal structure depends.

Animals↗
PubMed1996

Unstable angina--report from a Canadian expert roundtable.

Unstable angina is generally considered to encompass a spectrum of symptomatic manifestations of ischemic heart disease, intermediate between stable angina and acute myocardial infarction. Approximately 75,000 Canadians are hospitalized yearly with unstable angina. The pathophysiology of unstable angina is still imperfectly understood, but is related to the same pathophysiological factors underlying myocardial infarction and sudden cardiac death. In March 1995 a group of Canadian cardiologists met to review the current understanding of unstable angina and to define a Canadian approach to this common problem. Important issues and questions regarding the diagnosis and management of unstable angina were defined. The objective was to outline approaches to the management of unstable angina that would be appropriate in Canada. Topics discussed included definition, incidence, clinical presentations, pathophysiology, initial diagnostic and risk stratification approaches, acute medical management, role of invasive interventions and long term management.

Angina, Unstable↗
PubMed1995

Maximizing the benefits of thrombolytic therapy for acute myocardial infarction.

Thrombolytic therapy is a huge advance in the management of acute myocardial infarction (AMI). The results of large clinical trials over the past 9 years have unequivocally demonstrated its benefit: of every 1000 patients treated 30 will be saved, at a cost of two cases of nonfatal cerebral hemorrhage and seven of noncerebral major hemorrhage. The concurrent use of acetylsalicylic acid increases the benefit of thrombolytic therapy. Sales figures for thrombolytic agents indicate that their use in Canada is less than optimal and lags behind that in several European countries. Major educational efforts are needed to promote awareness of the efficacy of thrombolytic therapy and of optimal approaches for maximizing its potential benefit for patients with AMI.

Clinical Trials as Topic↗
PubMed1995

Restoration of urban waterways and vacant areas: the first steps toward sustainability.

Increased population pressure and human activities have significantly altered the effectiveness of functions of ecosystems ("ecosystem services") at the local and regional scale. Of primary importance is the decrease in water quality due to urban storm water runoff. A number of communities have initiated restoration strategies to improve water quality standards. One such strategy is the incorporation of riparian walkways with native flora. As a result of such restoration efforts, habitats for native fauna have improved, and the number and diversity of wildlife have increased in urban settings. Restoration of urban habitats also provides social and economic benefits to the surrounding community. Efforts to mitigate the loss of ecological resources by restoring native habitats on lots that cannot be developed or on abandoned lots hold a high, unrealized potential. Habitat restoration not only provides natural diversions to urban surroundings, but also enlightens and educates individual citizens about the importance of balanced ecosystems and the role of humans within ecosystems. Education is the primary step toward creating ecologically sustainable communities.

Animals↗
PubMed1994

The occurrence of heritable Mu excisions in starving cells of Escherichia coli.

A strain of Escherichia coli constructed by Shapiro has a segment of Mu bacteriophage DNA inserted between the araC and lacZ genes. Excision events that produce an in-frame fusion of lacZ to araB result in a cell (here designated Ara-Lac+) that can grow on lactose if arabinose is present as an inducer. Whether or not these excision events occur in the absence of selection for the Ara-Lac+ phenotype has figured prominently in the debate of the phenomenon known as 'directed' or 'adaptive' mutation. In an attempt to settle the issue, we have used classic fluctuation tests to show that cells capable of producing a clone of descendants that are phenotypically Ara-Lac+ do, indeed, arise in stationary phase cultures kept starving in depleted minimal medium. We found that Ara-Lac+ progenitors arise rapidly under these conditions, in contrast to the delayed appearance of Ara-Lac+ mutants when cells are incubated on lactose-arabinose minimal plates. Similar results are reported in the accompanying paper by Maenhaut-Michel and Shapiro, who used indirect selection to isolate Ara-Lac+ cells in the absence of selection. However, their sequencing data have introduced a new unexpected complication to the interpretation of all such experiments, and it is no longer clear exactly when the fusions arise.

Arabinose↗