Physician based surveillance system for occupational respiratory diseases: the experience of PROPULSE, Québec, Canada.

OBJECTIVE: To evaluate the feasibility of implementing a physician based surveillance system of occupational respiratory diseases (PROPULSE) in Québec with regard to physician participation rate, characteristics of reported cases, and comparison with official statistics from the Workers' Compensation Board (WCB). METHODS: All chest physicians and allergists in Québec were asked to report suspected new cases of occupational respiratory diseases, on a monthly basis, between October 1992 and September 1993. For each case, personal information was collected and the physician's opinion on whether the condition was related to work was categorised as highly likely, likely, and unlikely. RESULTS: Of the 161 physicians initially approached, 68% participated. Physicians rated 48% of suspected cases as highly likely, 29% as likely, and 20% as unlikely. The most often reported diagnosis was asthma (63%), followed by diseases related to asbestos (16%). Silicosis was less frequent (5%) but it was reported for six workers under 40 of whom five were involved in sandblasting activities. The high proportion of cases of asthma probably reflects the increasing importance of this disease but may also reflect the different patterns of reporting among physicians with different expertise. The distribution of cases by diagnostic category is quite different between the PROPULSE system and that of the WCB (annual mean number of compensated cases during a four year period). Asthma and allergic alveolitis are more frequent in PROPULSE, reactive airways dysfunction syndrome are about the same in both systems, and other diseases are more frequent among compensated cases. The most frequent sensitising agents reported for asthma were the same in both systems (isocyanates, flour, and wood dust). 15% of the PROPULSE cases were not covered by the WCB, and therefore would not be found in the board's official statistics. CONCLUSIONS: A physician based reporting procedure can be implemented as part of a surveillance system to supplement data from other sources and thus provide a better understanding of the occurrence of occupational respiratory diseases.     

Obstructive and restrictive ventilatory impairment in polyvinylchloride fabrication workers

Responses to a standardized respiratory symptom questionnaire, spirometry, and cross-shift decreases in lung function between 70 current employees of a polyvinylchloride (PVC) fabrication plant and a control group consisting of 48 men employed in a vegetable packing plant were compared. FEV1/FVC was significantly lower in the PVC workers. Cross-shift drops in Vmax75 of 15% or more were also more prevalent in the exposed group (p = .01). When examining the association between months of work within the exposed workforce and spirometric indices of airway obstruction, no relationship could be demonstrated. However, an inverse dose-response relationship was seen between level of FVC and duration of employment, suggesting a restrictive impairment. While the specific exposures have not been identified, it appears that employment in PVC fabrication may be associated with both obstructive and restrictive ventilatory effects.     

Radioimmunoassay of paralytic shellfish toxins in clams and mussels

Bulletin of Environmental Contamination and Toxicology -     

Comparison of continuous ambulatory peritoneal dialysis and hemodialysis patient survival with evaluation of trends during the 1980s.

To evaluate the mortality of continuous ambulatory peritoneal dialysis (CAPD) patients relative to hemodialysis (HD) patients, all Michigan residents 20 to 59 yr of age who initiated therapy for ESRD during the 1980s (N = 4,288) were studied. The study population was stratified by primary renal diagnosis (glomerulonephritis, hypertension, diabetes, other), and analyses were conducted within each group by Cox proportional hazards methods controlling for age, race, sex, and year in which chronic dialysis was initiated. Intent-to-treat (ITT) and treatment history (RxHx) censoring criteria were used. For patients with hypertension or other reported causes of ESRD, there was no significant difference in CAPD and HD patient mortality (relative risk (RR) = 0.99 and 1.05, respectively). In the ITT analysis, both glomerulonephritic (RR = 0.73; P = 0.10) and diabetic patients using CAPD experienced mortality rates lower than their HD counterparts. Among diabetics, this difference ranged from a RR of 0.40 to 0.70, being lowest for younger diabetics and statistically significant (P < or = 0.05) for ages 20 to 52 yr. Evaluation of mortality trends showed a significant (P < 0.01) decrease in diabetic CAPD mortality rates during the decade, whereas diabetic HD mortality rates increased (P = 0.06). Among diabetics, men had higher mortality rates than women (ITT--RxHx; RR = 1.22 to 1.27; P < 0.001) and white patients had higher mortality rates than black patients (ITT--RxHx, RR = 1.34 to 1.44; P < 0.001). Differences in mortality by sex and race were not found among nondiabetics, but mortality did increase significantly with age in all groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Patterns of cognitive change over time and relationship to age following successful treatment of Cushing's disease.

Chronically elevated levels of cortisol have been associated with changes in cognitive functioning and brain morphology. Using Cushing's disease as a model to assess the effects of high levels of cortisol on cognitive functioning, 27 patients with Cushing's disease were examined at baseline and three successive follow-up periods up to 18 months after successful surgical treatment. At all follow-up periods, patients were administered cognitive tests as well as measures of plasma and urinary free cortisol. Structural MRIs and a depression measure were taken at baseline and one-year follow-up. Results showed that there is a specific pattern of significant cognitive and morphological improvement following successful treatment. Verbal fluency and recall showed recovery, although brief attention did not. Age of participants was a significant factor as to when recovery of function occurred; younger patients regained and sustained their improvement in cognitive functioning more quickly than older participants. Improvement in verbal recall also was associated with a decrease in cortisol levels as well as an increase in hippocampal formation volume one year after treatment. Overall, these findings suggest that at least some of the deleterious effects of prolonged hypercortisolemia on cognitive functioning are potentially reversible, up to at least 18 months post treatment.     

Comparing social learning and family systems correlates of adaptation in youths with IDDM.

Evaluated social learning and family systems theoretical models to determine (a) whether illness-specific family relations (based on social learning theory) and general family behaviors (based on family systems theory) relate uniquely to the youths' illness-specific and psychosocial adaptation, and (b) whether these types of family relations covary or whether they represent distinct aspects of family functioning. Participants included 95 youths with insulin-dependent diabetes mellitus (IDDM) and their parents. Positive and supportive family relations (illness-specific family support, general family affection, general family adaptability) as well as conflictual and nonsupportive relations (i.e., illness-specific family nonsupport, general family conflict) were assessed. Results suggest that both illness-specific and general family relations uniquely predict the youths' dietary adherence and general psychosocial adaptation. Because illness-specific and general family relations also covary, broad-based models that include both types of family functioning seem warranted.     

A prenatal intervention study to improve timeliness of immunization initiation in Latino infants

This was a prospective randomized cohort study to assess the effectiveness of an educational immunization intervention with pregnant Latinas on timely initiation of infant immunization. Study participants were recruited from two community clinics in north San Diego County. A total of three hundred and fifty-two Latinas in the third trimester of pregnancy were recruited and randomly assigned to intervention or control groups. Participants received either a culturally and linguistically appropriate session on infant immunization (intervention) or a session on prevention of Sudden Infant Death Syndrome (control). The main outcome measures were pre-post immunization knowledge change and infant immunization status at 92 days. Immunization knowledge increased significantly in the intervention group [p < .0001, 95%CI (1.76, 2.47)]. No difference was found between groups in immunization series initiation: 95 percent of the children in the intervention group were up-to-date by 92 days from birth, and 93 percent of the control group was up-to-date at 92 days. The lack of significant association between receiving immunization education and infant immunization series initiation suggests that parent education may be necessary but not sufficient for timely immunization, particularly in clinics with effective well-child programs. Given the significant increase in immunization knowledge, the broader and perhaps more important implication is that language- and culturally specific infant health education messages in the prenatal period may have a positive long-term impact on the child's health and promote well-child care overall. Future studies should assess the role of prenatal well-child education in the context of clinics with low immunization levels     

Low oxygen delivery produced by anemia, hypoxia, and low cardiac output.

In pentobarbital-anesthetized dogs, oxygen delivery (DO2) was measured by thermodilution cardiac output and cooximeter determined oxygen content, while oxygen consumption (VO2) was measured independently by spirometry. Oxygen delivery was decreased by isovolemic dilutional anemia, breathing hypoxic gas mixtures, or cardiac tamponade to reduce cardiac output. Baseline VO2 (cc/kg/min) for the three groups was 5.9 +/- 0.7 (anemia), 5.4 +/- 0.4 (hypoxia), and 5.6 +/- 0.1 (low C.O.) (NS). A critical level of oxygen delivery (DO2crit) was found at 9-10 cc/kg/min (anemia), 10-11 cc/kg/min (hypoxia), and 9-10 cc/kg/min (low C.O.) (NS.). Below this level, VO2 fell (became supply dependent) and lactic acidosis occurred, regardless of the mechanism of impaired oxygen delivery.     

Correlation of visual field with quality-of-life measures at diagnosis in the Collaborative Initial Glaucoma Treatment Study (CIGTS).

PURPOSE: To examine the relationship between various clinical measures of visual field and patient-reported measures of symptoms and health status in a large cohort of patients with glaucoma at the time of diagnosis. PATIENTS AND METHODS: The 607 patients in the Collaborative Initial Glaucoma Treatment Study received standardized examinations of visual field at enrollment. In addition, they completed a telephone-administered, health-related quality-of-life questionnaire, which included the Visual Activities Questionnaire (VAQ) and a symptom and health problem checklist. RESULTS: The Visual Activities Questionnaire total and subscale scores, particularly the peripheral vision subscale, correlated weakly but significantly with global visual field scores. Symptoms attributed to glaucoma also correlated weakly but significantly to visual field scores. Correlations with other visual field measures, including only central and pericentral test locations in the scores, did not strengthen the association, and simulating binocular visual field scores produced only slightly stronger correlations. CONCLUSIONS: At diagnosis, most patients were relatively free of glaucoma-related impairments. Various visual field measures derived from clinical visual field test data were only modestly associated with patients' perceptions of health-related quality of life. As the Collaborative Initial Glaucoma Treatment Study population is followed up longitudinally, it will be important to see whether these pertinent associations become stronger.     

Thyroid autoantibodies in black and in white children and adolescents with type 1 diabetes mellitus and their first degree relatives

Genetic susceptibility is an important issue in understanding the mechanism of the autoimmune endocrinopathies and in assessing the risk of these conditions in pediatric patients. To this end, we evaluated autoantibodies to thyroid antigens, thyroglobulin (TgA) and microsomal antigen (TMA), in white and in American black juvenile patients with Type I diabetes mellitus (DM) to determine the predictive value of thyroid autoantibodies for the development of autoimmune thyroid disease. Sera from 159 patients (77 black and 82 white) with Type I DM were evaluated. A greater number of whites (41/82 or 50%) than blacks (12/72 or 16%) had thyroid autoantibodies (p less than 0.01). Fourteen patients (4 black and 10 white) exhibited hypothyroidism, and all had both TgA and TMA. Three patients (all black) had Graves' disease, one of whom had both TgA and TMA. Families of each racial group that had a diabetic child (proband) with thyroid autoantibodies (seropositive) or without thyroid autoantibodies (seronegative) were assessed for TgA and TMA as well as autoimmune thyroid disease. The prevalence of thyroid autoantibodies among siblings of seropositive probands was significantly greater than among the siblings of seronegative probands (p less than 0.01). The white sibling population showed a closer association of thyroid autoantibody prevalence with increasing age (p less than 0.05) than the blacks. Significantly more parents of probands than control parents exhibited thyroid autoantibodies (p less than 0.01). The general pattern of inheritance of either racial group showed that if one or both parents had thyroid autoantibodies, their progeny developed a significantly higher prevalence of thyroid autoantibodies than those of the seronegative parents. While there was no increase in overt thyroid disease among siblings of seropositive probands, a risk of developing autoimmune thyroid disease is probably imparted to these siblings by virtue of the thyroid autoantibodies.