Perestroika, fashion, and the universal glue.
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History, 20th Century↗
Biomedical subjects
D A Enarson
Publications and source records attributed to D A Enarson.
Validation of the smoking habits of a sample of the patient population seen in a pulmonary function laboratory.
From a structured history of 32 current smokers seen in the pulmonary function laboratory of a community hospital, we determined the number of cigarettes they smoked in 24 h. We also asked them to estimate their cigarette butt lengths from a visual model and to collect all cigarette butts over the next 24 h and mail them to us. We counted the butts, individually measured their lengths, and compared these with their previous estimates in order to validate their claims. While in the laboratory, we determined the level of carboxyhemoglobin in the peripheral blood of each patient. Patients tended to estimate the numbers of cigarettes that they smoked in units of five. Light smokers returned more butts and heavy smokers returned fewer butts than the numbers they reported as usually smoking. All patients were able to precisely estimate the average length of their cigarette butts, and they left butts of consistent lengths. There was no association between the numbers of cigarettes smoked and the butt lengths. Carboxyhemoglobin levels were positively associated with the numbers of cigarettes smoked in 24 h and negatively associated with the butt length and the time elapsed since the last cigarette was smoked, but these were not associated with the amount of tar in the cigarettes or with the number of years the person had smoked.
Adult↗
Clinical features of abdominal tuberculosis.
The clinical features of 81 cases of abdominal tuberculosis (TB) are presented. The peritoneum was involved in 41 patients, the ileocecal area in 17, the anorectal area in 16, and mesenteric glands in 8. There was one case each involving the liver and sigmoid colon. Most patients were young women. The tuberculin reaction was significant in 83% of patients tested, and 54% had evidence of TB elsewhere. Tuberculous peritonitis was more common in native North American Indians and presented as an acute abdomen, abdominal tumor, or cirrhosis. Asians developed the majority of ileocecal and mesenteric lymph node disease and were frequently diagnosed as having Crohn's disease, appendicitis, or cancer. Anorectal cases presented with fistulae or abscesses and usually had concomitant pulmonary TB. The disease was fatal in five patients (6%), four of whom were diagnosed only after death. One noncompliant patient had a relapse. All other patients were cured after receiving treatment.
Adult↗
Respiratory health in chrysotile asbestos miners in British Columbia: a longitudinal study.
A respiratory survey was undertaken in chrysotile asbestos miners in British Columbia consisting of a questionnaire, spirometry, chest radiography, and physical examination. The tests were performed in 1977 and again in 1983. The population groups studied included 63 "exposed" (working in the plant more than nine years), 52 "controls" (working in the plant less than five years), and 38 residents of the village at the minesite. A subset of 39 was identified with high exposure (worked in the mill more than five years). Measured levels of environmental particulates were similar over the entire period of operation of the plant (1.4 to 14.0 million particles per cubic foot and 0.7-88.0 fibres/cc in the mill; 0.2 to 2.7 mpcf and 0.6 to 9.3 f/cc in the mine). The exposed groups were more likely to report cough and breathlessness than the two other groups and were also more likely to have abnormal FVC and chest x ray films (the latter not significant, p greater than 0.05) and to be more likely to have a combination of these abnormalities. There was no trend to progression in the combination of abnormalities associated with exposure on follow up. The heavily exposed group showed a significantly worse trend in FVC. This adverse trend was confined to those with initial abnormalities. Tobacco smoking did not increase the trend to progression in this group.
Adult↗
A longitudinal study of the occurrence of bronchial hyperresponsiveness in western red cedar workers.
Two hundred twenty-seven workers in a western red cedar sawmill underwent methacholine bronchoprovocation testing at least 2 times during 3 surveys over a 2-yr period. At the first survey, workers completed a respiratory and occupational questionnaire, performed spirometry, gave serum for measurement of plicatic acid-specific IgE antibodies by radioallergosorbent testing, and had skin prick tests to detect atopy. Bronchial hyperresponsiveness was present initially in 18% of the workers. Approximately 15% of those with initially no hyperresponsiveness developed hyperresponsiveness during the follow-up period; 15% of those with initial hyperresponsiveness also lost it during follow-up. Development of hyperresponsiveness tended to coincide with a decrease in level of pulmonary function, whereas loss of hyperresponsiveness was associated with improvement in pulmonary function. Workers with either persistent bronchial hyperresponsiveness or with varying responsiveness had a higher prevalence of plicatic acid IgE antibodies and lower levels of initial pulmonary function than did workers with persistent nonresponsiveness. Workers with persistent hyperresponsiveness had higher initial estimated total airborne dust exposure than did other workers. Age, duration of sawmill employment, atopy, race, and cigarette smoking did not influence the occurrence of hyperresponsiveness. Levels of plicatic-acid-specific IgE antibodies did not change substantially over the 2 yr. These results indicate that immunologic sensitivity to plicatic acid and change in airway caliber are associated with the occurrence of bronchial hyperresponsiveness in cedar workers.
Allergens↗
Isoniazid for the tuberculin reactor: take it or leave.
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Decision Making↗
Airway size and the rate of pulmonary function decline in grain handlers.
Tracheal diameter and chest dimensions were measured from postero-anterior chest radiographs in grain handlers to prospectively identify airway size and chest size-related predictors of the rate of pulmonary function decline. A total of 634 grain workers were studied at the initial survey, of whom 239 satisfied the following inclusion criteria: (1) had a satisfactory chest radiograph taken at the initial survey in 1975, (2) performed spirometry at the 1975, 1978, and 1981 surveys, and (3) had no change in smoking status from 1975 to 1981. Radiographic measurements consisted of height of the right lung, transverse diameter of the chest at the level of the right diaphragm and at a level two-thirds up the right lung, and tracheal diameter (Tr). Areas of both lungs were measured by planimetry. Tr was only weakly related to height (r = 0.24). Increasing age was strongly associated with faster rates of FEV1 decline. After adjusting for the effects of age and cigarette smoking, Tr was the only radiographic measurement associated with FEV1 decline. Workers with Tr of 16 mm or less lost an average of 0.2% of their FEV1 per year compared to 0.9% per year for those with larger tracheas. This association was not modified by dust exposure estimates based on measurements of total dust. However, the strength of the association did depend upon smoking status, being strongest in current cigarette smokers (Tr less than or equal to 16 mm lost 0.2% annually and Tr greater than or equal to 21 mm lost 1.4% annually).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Fate of grainhandlers with bronchial hyperreactivity.
Bronchial reactivity to methacholine and to grain dust were determined in a group of grainhandlers whose spirometry was being studied prospectively. Six workers showed specific bronchial responses to grain dust (indicative of occupational asthma), 21 did not show reactivity to grain dust but had bronchial hyperreactivity to methacholine and 40 had neither. Those with hyperreactivity were older, had lower FEV1 at initial examination and were more likely to experience a significant decline in FEV1 over a single working shift. Over 6 years of follow-up, those with hyperreactivity were not more likely to leave work and although they showed a more rapid decline in lung function over the period, because of the small number of individuals studied the difference between those with and without bronchial hyperreactivity was not significant. Among those with hyperreactivity to methacholine, there was a significant positive association between change in FEV1 over a single workshift and change in FEV1 over six years of followup, not seen in those without hyperreactivity to methacholine. Moreover, reactivity to methacholine was a stable observation over 6 years in the majority of studied individuals. We conclude that in the presence of bronchial hyperreactivity to methacholine, change in FEV1 over a single workshift more precisely predicts the trend in FEV1 over time in grainhandlers.
Adult↗
Active abdominal tuberculosis in Canada in 1970-81.
We reviewed all 341 cases of abdominal tuberculosis reported in Canada between 1970 and 1981. Over the study period abdominal tuberculosis accounted for a stable proportion (0.8%) of all reported cases of tuberculosis in Canada. Its incidence declined steadily. It was more common in women, in native Indians and in people born in Asia. Detailed records of the 55 cases reported to Statistics Canada from British Columbia and of an additional 31 cases not reported to Statistics Canada (usually because they involved concomitant disease elsewhere, notably the lungs) were studied. Five of the 55 cases reported to Statistics Canada had been reported incorrectly. Of the 81 cases in British Columbia 51% involved peritonitis, 21% ileocecal disease, 20% anorectal disease, 10% mesenteric lymphadenitis, 1% disease of the sigmoid colon and 1% disease of the liver. The rate of bacteriologic confirmation was low (51%).
Abdomen↗
An analysis of pulmonary tuberculosis data in Taiwan and Korea.
An analysis is carried out on pulmonary tuberculosis survey data from Taiwan and Korea. A mathematical model based on a Markov process is developed and used to estimate transition rates between various disease states, as well as certain 'infection parameters', which measure the strength of the relative contributions of different disease states and of endogenous reactivation to the incidence of tuberculosis in the population. It is found that endogenous reactivation plays a primary role in generating cases, followed by chronic sources of infection, particularly those with drug-sensitive organisms. Some recommendations are made with regard to optimizing treatment regimens. The methodology can easily be applied to other countries.
Adult↗
Asthma, asthmalike symptoms, chronic bronchitis, and the degree of bronchial hyperresponsiveness in epidemiologic surveys.
Measurement of bronchial hyperresponsiveness has been suggested to be a useful test in identifying subjects with asthma in epidemiologic groups. We explored the association between the degree of bronchial hyperresponsiveness, respiratory symptoms suggestive of asthma, chronic bronchitis, and various definitions of asthma based upon information obtained from a questionnaire. We determined bronchial hyperresponsiveness by methacholine inhalation test, administered a standardized respiratory questionnaire, and performed spirometry on 1,392 male workers in various industries: 229 (16.5%) had PC20 less than 8 mg/ml, 66 (4.7%) had PC20 less than 2 mg/ml, and 8 (0.6%) had PC20 less than 0.5 mg/ml. Only 760 workers had no respiratory symptoms; no workers with PC20 less than or equal to 0.5 mg/ml, 31.0% of workers with PC20 greater than 0.5 but less than or equal to 2 mg/ml, and 38.0% of workers with PC20 greater than 2 but less than or equal to 8 mg/ml had no chest symptoms. Those reporting wheeze or breathlessness, and especially those with both symptoms, were significantly more likely to have bronchial hyperresponsiveness with a low PC20. The reporting of chest tightness did not influence this relationship, and there was no difference between the occurrence of "wheeze without a cold" and "persistent wheeze." Although there was a stronger association of PC20 less than or equal to 2 mg/ml with asthma than with chronic bronchitis, the association of PC20 greater than 2 and less than or equal to 8 mg/ml was not different with asthma than with chronic bronchitis. Bronchial hyperresponsiveness was more closely associated with asthma than with any asthmalike symptoms ascertained by a questionnaire developed for the study of chronic bronchitis.(ABSTRACT TRUNCATED AT 250 WORDS)
Asthma↗
Inner-city survey for tuberculosis: evaluation of diagnostic methods.
A total of 1,271 persons living in a socially and economically depressed, inner-city area of Vancouver, British Columbia, voluntarily attended a tuberculosis case-finding campaign. Chest x-ray, on-the-spot specimen of sputum, and tuberculin skin test were offered at the time of the first attendance. All 3 diagnostic methods were found to be well accepted, with 93% of the participants having an x-ray, over 95% producing a sputum specimen, and almost 95% having a tuberculin test (a quarter of these did not, however, report for reading of the test). Eight cases of bacteriologically confirmed pulmonary tuberculosis were found: 6 suspected on x-ray (the remaining 2 films were abnormal but not diagnostic of tuberculosis), and 6 being positive on smear and/or culture of the initial on-the-spot sputum specimen. Examination of a second specimen of sputum diagnosed all of the 8 active cases identified by the survey. These results suggest that, in this particular setting, a chest radiogram taken by a transportable chest x-ray apparatus or examination of 2 sputum specimens might be equally successful at detecting all cases of active pulmonary tuberculosis within the time required for sputum culture. Examination of the sputum smear immediately identifies all the more infectious cases of pulmonary tuberculosis. The prevalence rate of 629 per 100,000 among those presenting themselves to this campaign illustrates the high-yield which might be achieved by active case-finding projects in known high-incidence segments of a generally low-incidence population.
Adult↗
Incidence of active tuberculosis in the native population of Canada.
We analysed the incidence rates of active tuberculosis reported between 1970 and 1981 in three groups of people born in Canada: Inuit, registered Indians and others (mainly of European origin). While the rates of tuberculosis were quite low in the last group, which constitutes about 82% of the population of Canada, they were 16 times higher among Indians and 24 times higher among Inuit. Some 20 to 30 years ago the Inuit had the highest recorded rate of tuberculosis in the world; with an intensive program the rate decreased sharply. Such a program has not been implemented among the Indian population, and the incidence rate has not decreased as rapidly. A major effort is required to satisfactorily control tuberculosis among Indians. In addition, we must not allow our efforts to slacken in the control of tuberculosis among the Inuit.
BCG Vaccine↗
Plicatic acid-specific IgE and nonspecific bronchial hyperresponsiveness in western red-cedar workers.
In a cross-sectional survey of 652 workers in a western red-cedar sawmill, we obtained data on symptoms, pulmonary function, immediate skin reactivity to common allergens, nonspecific bronchial responsiveness, total IgE level, and sensitization to plicatic acid conjugated with human serum albumin as measured by RAST. Dust exposure was estimated by personal and area sampling for total dust during a work shift and cumulative exposure by duration of employment. Seven percent of the workers had an elevated RAST, and 20% had nonspecific bronchial hyperresponsiveness. Elevation in RAST was associated with bronchial hyperresponsiveness. Almost half (46%) of the workers with RAST elevation had bronchial hyperresponsiveness compared to 18% in workers with no RAST elevation. The association was unaffected by total IgE level or by limiting the analysis to workers without respiratory symptoms and was most apparent in younger workers. Bronchial hyperresponsiveness was associated with increased prevalence of respiratory symptoms as well as with lower levels of pulmonary function. The likelihood of bronchial hyperresponsiveness increased with increasing age but was unrelated to the dust-exposure concentration. RAST elevation was unrelated to employment duration or dust exposure and was not associated with an increased prevalence of symptoms or lower levels of pulmonary function independent of bronchial hyperresponsiveness. We conclude that plicatic acid-specific IgE and nonspecific bronchial hyperresponsiveness are associated in western red-cedar workers and that this association may reflect a causal connection.
Adult↗
Occupational exposure to chlorophenates. Renal, hepatic and other health effects.
A group of 71 chlorophenate-exposed sawmill workers were identified as part of a group undergoing an extensive health and environmental evaluation in a pulp mill. This group was compared with a group (N = 351) with no physical proximity to the area in which chlorophenates were used. Exposure was higher for those directly handling the wood and lower for those working in the area but not handling the wood. Those with chlorophenate exposure were not significantly more likely to report a history of jaundice or liver, kidney or heart disease. Moreover, the serum creatinine, bilirubin, glutamic oxaloacetic transaminase (GOT), and alkaline phosphatase values did not differ from those of the reference group. The hemoglobin level was similar in the three groups. But the peripheral blood leukocyte count was marginally lower in the exposed groups and their hematocrit was reduced, significantly so for the heavily exposed group. Urinalysis showed an increased prevalence of microscopic hematuria, especially with lower cell counts. No unequivocal explanation is available for the reduced hematocrit or the low level of hematuria.
Adult↗
Tuberculosis in female nurses in British Columbia: implications for control programs.
All 57 cases of active tuberculosis in women in nursing and related assisting occupations (henceforth called nurses) notified in British Columbia between 1969 and 1979 were reviewed. This represented a mean annual incidence of active tuberculosis of 2.6/10 000, similar to that in other women, adjusted for age and birthplace. The rate varied according to birthplace: among nurses born in Canada the rate was 2.0, almost twice that of other women born in Canada, and among those born in Asia it was 24.8, less than half that of other women born in Asia. The nurses born in Canada who had received BCG (bacille Calmette-Guérin) during their training were least likely to contract tuberculosis, the incidence rate being comparable to that among other women. Those whose results of tuberculin testing were negative but who were not vaccinated were twice as likely to contract tuberculosis, whereas those whose results were positive at the start of training were four times as likely to contract tuberculosis. The feasibility and implications of a tuberculosis screening and surveillance program are discussed.
Adolescent↗
Determinants of changes in FEV1 over a workshift.
Measurement of workshift change in FEV1 is a useful predictor of respiratory disease among cotton workers and grainhandlers. Certain factors affect this measurement and must be considered in the analysis. Response varies with the time of day at which the measurement is taken. Tobacco smoking, immediate skin reactivity to common allergens, age, and initial level of FEV1 are other factors that must be considered when this measurement is used to study effects of occupational exposure to respiratory hazards.
Adult↗
Rapid decline in FEV1 in grain handlers. Relation to level of dust exposure.
We have prospectively studied the respiratory health of a cohort of grain elevator workers in the Canadian west coast terminal elevators, beginning in 1975 and following them for 6 yr. We have used a "nested" case-control model to identify determinants of the worst trend in FEV1 over this period. The 10% of participants in this category had a mean decline of greater than 100 ml/yr. They were significantly more likely to have had a decline in FEV1 over a work week and to have nonspecific bronchial hyperreactivity. There was a significant relationship between the odds ratio of being a case and the mean level of dust exposure associated with the job and location at the work site; cases were associated with mean total dust levels greater than 5 mg/m3. We found no relationship between the odds ratio of being a case and a number of host factors, such as immediate skin reactivity to common allergens, history of asthma, bronchitis, or hay fever, or presence of respiratory symptoms. We conclude that exposure to grain dust at levels greater than 5 mg/m3 is associated with a serious adverse trend in FEV1.
Adult↗