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B Case

Publications and source records attributed to B Case.

35 records · Page 2Linked to original sources

Mesothelioma and asbestos fiber type. Evidence from lung tissue analyses.

Lung tissue samples from 78 cases from autopsy of mesothelioma in Canada, 1980 through 1984, and from matched referents were examined by optical and analytical transmission electron microscopic study. Concentrations of amosite, crocidolite, and tremolite fibers, and of typical asbestos bodies discriminated sharply between cases and referents. The distributions of chrysotile and anthophyllite/talc fibers and of all other natural and man-made inorganic fibers (greater than or equal to 8 microns) in the two series were quite similar. Relative risk was related to the concentration of long (greater than or equal to 8 microns) amphibole fibers with no additional information provided by shorter fibers. The proportion of long fibers was much higher for amphiboles than chrysotile and, except for chrysotile, systematically higher in cases than referents. Amphibole asbestos fibers could explain most mesothelioma cases in Canada and other inorganic fibers, including chrysotile, very few. Fibrous tremolite, contaminant of many industrial minerals including chrysotile, probably explained most cases in the Quebec mining region and perhaps 20% elsewhere.

Asbestos↗

Hypogammaglobulinemia in children undergoing continuous ambulatory peritoneal dialysis.

Humoral immunity was evaluated in seven children undergoing continuous ambulatory peritoneal dialysis (CAPD). Five children (71%) had serum immunoglobulin levels which were more than 2 SD below the mean for age. One mechanism contributing to hypogammaglobulinemia was loss via the peritoneal membrane. Daily losses of IgG into peritoneal dialysis effluents represented 7%-29% of normal daily IgG synthesis, and losses increased with duration of CAPD therapy. Despite the observed hypogammaglobulinemia, all children had protective antibody responses to immunization.

Body Fluids↗

Respiratory cancer in chrysotile textile and mining industries: exposure inferences from lung analysis.

In an attempt to explain the much greater risk of respiratory cancer at the same cumulative exposure in asbestos textile workers in Charleston, South Carolina, than in Quebec miners and millers, both exposed to chrysotile from the same source, 161 lung tissue samples taken at necropsy from dead cohort members were analysed by transmission electron microscopy. Altogether 1828 chrysotile and 3270 tremolite fibres were identified; in both cohorts tremolite predominated and fibre dimensions were closely similar. Lung fibre concentrations were analysed statistically (a) in 32 paired subjects matched for duration of employment and time from last employment to death and (b) in 136 subjects stratified by the same time variables. Both analyses indicated that the Quebec/Charleston ratios for chrysotile fibre concentration in lung tissue were even higher than the corresponding ratios of estimated exposure intensity (mpcf). After allowance for the fact that regression analyses suggested that the proportion of tremolite in dust was probably 2.5 times higher in Thetford Mines, Quebec, than in Charleston, the results from both matched pair and stratification analyses of tremolite fibre concentrations in lung were almost the same as for chrysotile. It is concluded that neither fibre dimensional differences nor errors in estimation of exposure can explain the higher risks of lung cancer observed in asbestos textile workers. The possible co-carcinogenic role of mineral oil used in the past in asbestos textile plants to control dust provides an alternative hypothesis deserving consideration.

Adult↗

Disseminated coccidioidomycosis: clinical, immunologic and therapeutic aspects.

A patient with disseminated coccidioidomycosis initially had pulmonary and skin manifestations and survived for 14 years before dying of meningitis due to Coccidioides immitis. In addition to several courses of amphotericin B therapy the patient received injections of transfer factor derived from appropriate donors and miconazole nitrate therapy. The immunologic defence mechanisms of the patient during the course of his disease were studied and the possibility of a cell-mediated immunologic defect, potentially reversible by transfer factor, was demonstrated.

Adult↗

Lung mineral fibers of former miners and millers from Thetford-Mines and asbestos regions: a comparative study of fiber concentration and dimension.

Fiber dimension and concentration may vary substantially between two necropsy populations of former chrysotile miners and millers of Thetford-Mines and Asbestos regions. This possibility could explain, at least in part, the higher incidence of respiratory diseases among workers from Thetford-Mines than among workers from the Asbestos region. The authors used a transmission electron microscope, equipped with an x-ray energy-dispersive spectrometer, to analyze lung mineral fibers of 86 subjects from the two mining regions and to classify fiber sizes into three categories. The most consistent difference was the higher concentration of tremolite in lung tissues of workers from Thetford-Mines, compared with workers from the Asbestos region. Amosite and crocidolite were also detected in lung tissues of several workers from the Asbestos region. No consistent and biologically important difference was found for fiber dimension; therefore, fiber dimension does not seem to be a factor that accounts for the difference in incidence of respiratory diseases between the two groups. The greater incidence of respiratory diseases among workers of Thetford-Mines can be explained by the fact that they had greater exposure to fibers than did workers at the Asbestos region. Among the mineral fibers studied, retention of tremolite fibers was most apparent.

Aged↗

Walking around the elephant: a critical-thinking strategy for decision making.

The parable of the blind men and the elephant provides a metaphor for emphasizing important characteristics of critical thinking and strategies for decision making. The article describes critical thinking as a process and cognitive skill that functions in identifying and defining problems and opportunities for improvement; generating, examining and evaluating options; reaching conclusions and decisions, and creating and using criteria to evaluate decisions. Critical thinking improves the quality of professional and personal decisions. Critical thinking also contributes to the effectiveness of group decision making by creating synergy and collaboration. The article presents evidence of the crucial nature of critical thinking in nursing practice, management, and executive roles, and in the practice of continuing education and staff development. The article identifies and develops the major defining characteristics of critical thinking. Illustrating the characteristics in practical examples, the article suggests ways to foster critical thinking for ourselves, with our learners, with managers, and with our colleagues.

Decision Making↗

Breathing AIR into adult learning.

This article summarizes adult learning principles using the acronym AIR: Active involvement, Individual differences, Relevance and motivation. Highlighted are practical strategies to operationalize each of the AIR concepts for professional development. Revisiting adult learning principles can assist continuing education and staff development personnel to face challenges effectively and "walk the talk" in adult learning endeavors.

Adult↗

[Could the Quebec Tumor Registry be used to identify risks of occupational cancers?].

Many countries have used their tumor registries to conduct studies on cancer and occupation. In the past, the Quebec Tumor Registry (QTR) has collected information on occupation of cases. The form currently in use has a space to include this information but it is not mandatory to do so. Among male cases of naso-sinusal, pleural and ocular cancer, diagnosed between 1975 and 1979, and aged 16 to 64, 72% had information on occupation. The occupation registered at the QTR and the occupation given by the case himself during epidemiological studies on bladder cancer and leukemia are respectively the same in 64% and 69% of cases. The association between mesothelioma and work in asbestos related industries was not found in the present study. Explanations and recommendations are given.

Adolescent↗

Critical thinking: challenging assumptions and imagining alternatives.

Critical thinking skills are currently a focus for clinical and school settings because they help challenge current assumptions and lead to innovative changes. Today, with the need to restructure health care and promote positive outcomes for patients, nurses are encouraged to consider new alternatives for nursing delivery systems and patient care. Critical care nurses can expand their critical thinking skills to be leaders in this field.

Critical Care↗