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Biomedical subjects

E Dorken

Publications and source records attributed to E Dorken.

17 recordsLinked to original sources
PubMed1987

Significance of the tuberculin test in the elderly.

Nine hundred thirty-three persons over 65 years of age, residing in long-term or extended-care facilities in Vancouver, Canada, had tuberculin tests. In addition to PPD-tuberculin, 5 TU and 250 TU, we used PPD-Battey, Candida albicans, mumps, and Trichophyton antigens. Twenty-five percent reacted to 5 TU of tuberculin with reactions of 10 mm or more. There was a progressive, substantial loss of reactivity with advancing age. Reactions to PPD-Battey greater than to PPD-T 5 TU were infrequent, suggesting that atypical mycobacterial infections were uncommon and that positive reactions to PPD-T, 250 TU, were predominantly caused by infections with Mycobacterium tuberculosis. Based on the results of both 5 TU and 250 TU, the prevalence of tuberculous infection exceeded 60 percent. Waning of tuberculin sensitivity appears to be an integral part of the aging process. Testing with nonmycobacterial antigens used in this study shed no further light on the problem of anergy in the elderly, as the number of reactors was smaller than that obtained with PPD-tuberculin.

Aged↗
PubMed1986

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↗
PubMed1984

Ten year evaluation of a trial of chemoprophylaxis against tuberculosis in Frobisher Bay, Canada.

A trial of chemoprophylaxis to prevent tuberculosis in Canadian Inuit (Eskimos) was carried out in Frobisher Bay, Canada during 1971-1974. A completely supervised regimen of isoniazid and ethambutol thrice weekly for 18 months was administered. A 10-year evaluation of 370 treated persons and 217 control subjects demonstrates the sustained value of adequate chemoprophylaxis in reducing the risk of developing active tuberculosis in the 3 groups under study--1, those with a previous episode of active tuberculosis, 2, positive tuberculin reactors with normal chest X-ray and 3, BCG vaccinated individuals with large tuberculin reactions. There were 3 cases of active disease in the treated group, a risk of 0.1% per annum, and 13 cases among the controls, a risk of 1.0% per annum.

Adolescent↗
PubMed1984

Host factors affecting longitudinal decline in lung spirometry among grain elevator workers.

The host factors affecting the longitudinal decline in lung function among 267 white male grain elevator workers who were still working in the industry and did not change their smoking habits over a period of six years were studied. Spirometric measures declined more rapidly in older grain handlers as compared with younger workers. Smokers had slightly greater decline in spirometry compared to nonsmokers, but the differences failed to reach the level of statistical significance. Acute changes in lung function over the course of one work week during the initial study were also positively correlated with subsequent decline in lung function, as was bronchial hyperreactivity determined during the follow-up study. Positive immediate skin reactivity to common allergens, presence and absence of respiratory symptoms, and initial lung function did not appear to influence the subsequent decline in lung function in this group.

Adult↗
PubMed1983

Tuberculosis in Inuit.

Tuberculous infection was first introduced to the majority of the Inuit (Eskimos) in the first half of this century. In the 1950s tuberculosis became a grave problem with the mortality rate approaching 1% per annum and the incident rate almost 3%. The annual risk of infection has been estimated at 25% per annum. These are probably the highest rates recorded anywhere in the world in the 20th century. Some 20-30 years ago, an intensive case-finding programme as well as a treatment programme began in all three jurisdictions where the Inuit live (northern Canada, Alaska and Greenland). The preventive measures differed; Alaska relying mainly on chemoprophylaxis and Greenland on BCG vaccination, while Canada adopted both measures. Over the last 20 years, the rates fell rapidly with the mortality rate approaching zero, and the morbidity (incidence) rate falling (Canadian Inuit) by the record 14% per annum. The high rates in the Inuit were, in part, an expression of the lack of 'natural' resistance acquired by other races through the exposure to tubercle bacilli for many generations. Over-crowding in igloos and frequent starvation among those Inuit who relied on cariboo meat, undoubtedly contributed a great deal to the gravity of the problem. The rapid decline of the rates is without doubt primarily caused by the intensive tuberculosis programme and the compliance of the Inuit with the demands of this programme; better housing and in some cases, improved nutrition doubtlessly also played a part.

Cross-Sectional Studies↗
PubMed1982

Tuberculous pleurisy.

A review of the records for all cases of tuberculous pleurisy notified in Canada from 1970 through 1974 and in British Columbia from 1967 through 1976 showed that in the periods studied the annual incidence of this condition was low, just under nine cases per million population, and was declining. The disease commonly occurred a few months after a primary infection with tubercle bacilli. Bacteriologic confirmation of the diagnosis was possible in only 40% of the cases since biopsy specimens were not consistently cultured.

Adolescent↗
PubMed1980

Non-respiratory tuberculosis in Canada. Epidemiologic and bacteriologic features.

Of the total cases of tuberculosis reported in Canada between 1970-1974, approximately one-sixth (3671 cases) involved primarily non-respiratory organs. Common diagnostic entities were genitourinary tuberculosis (1516 cases), lymphadenitis (1083 cases), bone and joint tuberculosis (555 cases), gastrointestinal tuberculosis (155 cases) and meningitis (138 cases). The remainder (224 cases) involved a wide variety of organs. Between 1967 and 1977 the morbidity rates of most non-respiratory manifestations steadily declined, the decline in meningitis being particularly marked. In contrast, lymphadenitis did not decline to the same extent, reflecting changing immigration patterns. The major diagnostic entities differed in their age and sex patterns and in their contribution to total cases by birthplace and ethnic group. In particular, the preponderance of lymphadenitis in females, and in the Asian-born was striking. Mycobacterium bovis was isolated infrequently and bacillary resistance to antituberculosis drugs was also uncommon. In a substantial proportion of cases, active tuberculosis was present concurrently at another site, or there was historical or radiologic evidence of previous active tuberculosis. Despite this additional evidence, delay and failure of diagnosis were common. An increased clinical awareness of tuberculosis is required, particularly in view of the often enigmatic presentation of non-respiratory disease.

Age Factors↗
PubMed1978

Failure of diagnosis as a factor in tuberculosis mortality.

In British Columbia between January 1970 and December 1974 active tuberculosis was diagnosed only after death in 69 cases; this was more frequent for miliary tuberculosis (31% of reported cases) than for advanced pulmonary tuberculosis (3% of cases). Although 28% of the patients were more than 75 years old, some were much younger, and 38% of the latter were alcoholics. More than 50% of the patients had been hospitalized before death, for a mean of 14.5 days; they were most frequently thought to have pneumonia or cancer at the time of death. Clearly, increased awareness of the continuing presence of tuberculosis in our society is needed.

Aged↗
PubMed1978

A respiratory survey of cedar mill workers. I. Prevalence of symptoms and pulmonary function abnormalities.

A respiratory-occupational questionnaire and spirometry were used to compare the prevalence of symptoms and pulmonary function abnormalities in 405 workers exposed to red cedar dust and 252 control workers exposed to other wood dusts. Compared with controls, the cedar workers were found to have a significantly higher prevalence of respiratory symptoms, cough, phlegm, wheeze and breathlessness, as well as more rhinitis and conjunctivitis. While, as expected, there was a clear relationship between respiratory symptoms and cigarette smoking, there was also evidence to suggest a synergistic effect between exposure to cedar dust and smoking. There was no difference in the lung function between cedar workers and controls. Sixty-five workers in the control group previously had worked in red cedar mills; they had a higher prevalence of respiratory symptoms than other workers in this group. Red cedar asthma was found in only 1.1% of the cedar workers. This condition usually develops in the early months of exposure, and workers who are affected tend to leave the industry. The probable incidence of red cedar asthma was estimated to be higher, around 4-5%.

Adult↗
PubMed1976

Chemoprophylaxis trial in Canadian Eskimos.

One hundred and two cases of inactive tuberculosis, 165 positive tuberculin reactors and 103 previous BCG vaccinated individuals showing large tuberculin reactions were placed on the completely supervised regimen consisting of isoniazid and ethambutol given three times a week. Over 90% of these individuals completed 18 months' treatment. There were no active cases of tuberculosis among the treated groups during the observation period averaging 34.8 months. The control groups consisting of 217 individuals had 9 cases of active tuberculosis giving an annual risk of developing the disease of 1.8 per 1000.

Adult↗
PubMed1972

Rifampin.

Rifampin is a potent antituberculous drug. In the treatment of drug-resistant tuberculosis it is highly effective provided it is given in combination with other drugs to which the patient's organisms are sensitive. Rifampin and ethambutol is a particularly powerful combination and will achieve almost 100% sputum conversion. It seems likely that rifampin will replace streptomycin, and ethambutol will replace PAS in first-treatment cases. Optimum first-line treatment will thus consist of rifampin, INH and ethambutol, with the probability of almost 100% success and the possibility also that the total duration of treatment may be considerably reduced. Rifampin is well tolerated but it may give rise to liver dysfunction and thrombocytopenia in a small proportion of patients. Patients treated with rifampin must be kept under close supervision because of the risk of side effects and, more important, because irregular treatment may lead to the development of rifampin-resistant organisms.

Adult↗