Potential significance of airborne fiber dimensions measured in the U.S. refractory ceramic fiber manufacturing industry.

BACKGROUND: To determine dimensions of airborne fibers in the U.S. refractory ceramic fiber (RCF) manufacturing industry, fibers collected through personal air sampling for employees at RCF manufacturing and processing operations have been measured. METHODS: Data were derived from transmission electron microscopy analyses of 118 air samples collected over a 20-year period. RESULTS: Characteristics of sized fibers include: diameter measurements of <60; 0.19 to 1.0 micron, m of which 75% are less than 0.6 micron and length ranging from < 0.6 to > 20 micron, with 68% of fibers between 2.4 and 20 micron. CONCLUSIONS: Exposures in RCF manufacturing include airborne fibers with dimensions (diameter < 0.1-0.4 micron, length < 10 micron) historically associated with biological effects in pleural tissues. Air sampling data and a review of studies relating fiber size to pleural effects in animals and humans support the belief that information on fiber dimensions is essential for studies with synthetic vitreous fibers.     

Quantifying the disease impact of cigarette smoking with SAMMEC II software

Smoking-Attributable Mortality, Morbidity, and Economic Costs Software, Release II (SAMMEC II) has been developed for the Office on Smoking and Health, Public Health Service, to permit rapid calculation of deaths, years of potential life lost, direct health-care costs, indirect mortality costs, and disability costs associated with cigarette smoking. For the mortality-related measures, age-specific and age-adjusted rates are also calculated. The pivotal epidemiologic measure in these calculations is the smoking-attributable fraction, and attributal risk measure. A multiple-measure approach (attributable mortality and economic costs) to quantifying a health problem is termed "disease impact estimation." Previously, national and State-specific estimates of smoking-attributable mortality and economic costs were calculated using SAMMEC software, the predecessor of SAMMEC II. SAMMEC II is completely menu-driven and operates within the Lotus 1-2-3 software as a set of linked spreadsheets. SAMMEC II adapts national epidemiologic methods for use by State and local health departments. Increased exposure of public health professionals to disease impact estimation techniques, as demonstrated by SAMMEC II, will lead to improvements in both methodology and the quality of smoking-related health data. The primary purpose of SAMMEC II, however, is to provide State or locality-specific data on the health consequences of smoking to policymakers and public health professionals in these jurisdictions.     

Z's, P's, and double blinds: making sense of published research

Most nurses are inadequately prepared for critically analyzing research. Gastrointestinal "nursing" encompasses a diverse group which includes registered nurses, licensed practical and vocational nurses and trained technicians. The parameters of practice sometimes overlap within this group regardless of formal educational background. It is imperative to the safety of ourselves and our patients and to the advancement of gastrointestinal nursing practice that we are capable of making intelligent, informed decisions regarding the research and reports we are offered. This paper discusses the key elements of research methodology to enhance the interpretive skills of the reader.     

Psychosocial disability during the long-term course of unipolar major depressive disorder

BACKGROUND: The goal of this study was to investigate psychosocial disability in relation to depressive symptom severity during the long-term course of unipolar major depressive disorder (MDD). METHODS: Monthly ratings of impairment in major life functions and social relationships were obtained during an average of 10 years' systematic follow-up of 371 patients with unipolar MDD in the National Institute of Mental Health Collaborative Depression Study. Random regression models were used to examine variations in psychosocial functioning associated with 3 levels of depressive symptom severity and the asymptomatic status. RESULTS: A progressive gradient of psychosocial impairment was associated with a parallel gradient in the level of depressive symptom severity, which ranges from asymptomatic to subthreshold depressive symptoms to symptoms at the minor depression/dysthymia level to symptoms at the MDD level. Significant increases in disability occurred with each stepwise increment in depressive symptom severity. CONCLUSIONS: During the long-term course, disability is pervasive and chronic but disappears when patients become asymptomatic. Depressive symptoms at levels of subthreshold depressive symptoms, minor depression/ dysthymia, and MDD represent a continuum of depressive symptom severity in unipolar MDD, each level of which is associated with a significant stepwise increment in psychosocial disability.     

Cost and health related quality of life consequences of multiple sclerosis

Objectives: To (i) quantify the cost of multiple sclerosis (MS) to the Canadian health care system and society; (ii) measure health utility in MS patients, and (iii) examine the influence of disability on patient utility and health care costs. Materials and methods: A comprehensive patient survey and chart review of relapsing MS patients in remission, relapse and recalling a relapse. Results: Annual remission costs increased with EDSS level ($7596 at EDSS 1, $33 206 at EDSS 6). At all EDSS levels the largest costs were due to inability to work, which increased with EDSS. The average relapse cost for all EDSS levels was $1367. An inverse correlation was found between EDSS level and patient utility for patients in remission and relapse. The decrease in remission health utility from EDSS 1 to 6 was 0.24, which is 25% greater than the difference in health status between an average 25 and 85 year-old. Conclusions: This study demonstrates that MS produces substantial health care costs and reductions in patient quality of life and ability to work, losses that can be avoided or delayed if disease progression is slowed. These data provide health-care decision-makers with the opportunity to consider the full impact of MS when faced with budget allocation decisions.     

Abrin Poisoning

Abrin is a toxic protein obtained from the seeds of Abrus precatorius (jequirity bean), which is similar in structure and properties to ricin. Abrin is highly toxic, with an estimated human fatal dose of 0.1–1 µg/kg, and has caused death after accidental and intentional poisoning. Abrin can be extracted from jequirity beans using a relatively simple and cheap procedure. This satisfies one criterion of a potential chemical warfare agent, although the lack of large scale production of jequirity seeds means that quantity is unavailable for ready mass production of abrin for weapons. This contrasts with the huge cultivation of Ricinus seeds for castor oil production. At the cellular level, abrin inhibits protein synthesis, thereby causing cell death. Many of the features observed in abrin poisoning can be explained by abrin-induced endothelial cell damage, which causes an increase in capillary permeability with consequent fluid and protein leakage and tissue oedema (the so-called vascular leak syndrome). Most reported cases of human poisoning involve the ingestion of jequirity beans, which predominantly cause gastrointestinal toxicity. Management is symptomatic and supportive. Experimental studies have shown that vaccination with abrin toxoid may offer some protection against a subsequent abrin challenge, although such an approach is unlikely to be of benefit in a civilian population that in all probability would be unprotected.