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Biomedical subjects

J Ribak

Publications and source records attributed to J Ribak.

At least 19 recordsLinked to original sources
PubMed1992

[Occupational scleroderma due to organic solvent exposure].

Progressive systemic sclerosis (PSS; scleroderma) is a multisystem disease characterized by inflammation, fibrosis and degeneration of the integument, with similar changes and vascular lesions in the heart, lungs, kidneys, gastrointestinal tract and synovia. Its etiology is not clear. Several occupational exposures have been implicated as potential causes of PSS and scleroderma-like diseases. Among them are vinyl chloride monomer, silica dust, epoxy resin, and benzene and other solvents, aromatic and aliphatic, specifically chlorinated (trichloroethylene, perchloroethylene and trichloromethane). We present a patient whose illness was diagnosed as occupationally induced PSS. During 13 years of work renovating carburetors he was heavily exposed to trichloromethane. To the best of our knowledge this is the first reported case of PSS due to exposure to organic solvents in Israel; very few cases have been reported from abroad.

Adult↗
PubMed1992

Adverse health effects in workers exposed to cadmium.

One hundred fifty-two workers who had been exposed to different levels of cadmium (Cd) absorption (blood Cd mean 16.34 micrograms/L, median 11.0 micrograms/L) in a factory making nickel-cadmium batteries were studied. A physical evaluation, as well as blood and urine cadmium and N-acetyl-beta-D-glucosaminidase (NAG), and other routine laboratory tests were performed in order to assess the relationship between different levels of exposure to occupational cadmium and potential cadmium-induced renal damage and other adverse health effects. We found significant correlation between levels of cadmium exposure and a selected group of symptoms and signs. The best predictor of this group of symptoms and signs was an indicator called internal dose index (Cd x exposure time). This indicator appears as the strongest, even after control by confounding factors, such as age and smoking. It is concluded that this index can be used for biological monitoring.

Adult↗
PubMed1992

Survival of asbestos insulation workers with mesothelioma.

Malignant mesothelioma is a lethal disease. It is rare in the general population; however, workers exposed to asbestos suffer significant burdens of the neoplasm. The survival time of 457 consecutive fatal cases of pleural and peritoneal mesothelioma that occurred among 17,800 asbestos insulation workers observed prospectively from 1 January 1967 to 1 January 1987 was studied. Mean survival time from initial presentation of the disease to death was 11.4 months for the pleural mesothelioma patients compared with 7.4 months for the peritoneal group. This difference was statistically significant. Mean survival time from diagnosis to death was shorter for both groups of patients: 8.4 months for pleural mesothelioma v 5.8 months for the peritoneal cases. In conclusion, survival time in mesothelioma patients is short; most die within a year from the onset of the initial symptoms. No effective therapy is yet available.

Age Factors↗
PubMed1992

Personal determinants of leisure-time exercise activities.

This study investigated the importance of personal determinants such as self-efficacy, beliefs about the contribution of exercise, health locus of control, and dispositional optimism for leisure-time exercise in a working population. The main predictors of such exercise were beliefs and self-efficacy with the generalization of the latter to eat correctly. Beliefs and efficacy expectations were highly correlated. Neither health locus of control nor dispositional optimism was related to leisure-time exercise; however, optimism was related to the positive belief that exercise contributes to health. Ramifications of the findings were carefully described.

Adolescent↗
PubMed1992

[Passive smoking: clinical aspects and workers' awareness].

Tobacco smoke contains a wide range of toxic vapors and particles which when inhaled are injurious both to the smoker himself (active smoking) and to those around him (passive smoking). It is extremely difficult to define precisely the harmful effects of passive smoking on the individual's health because of problems in quantifying the extent of exposure. A number of epidemiological studies indicate that exposure to passive smoking in public places is circumstantially, but marginally, linked to cardiovascular morbidity and mortality, as well as to pulmonary morbidity. both benign and malignant. Many clinical conditions are further aggravated by exposure to a combination of tobacco smoke and other industrial materials, including cadmium, and radon daughters. Passive smoking during pregnancy constitutes a health hazard for both mother and fetus. Exposure to passive smoking during childhood may predispose to benign and malignant pulmonary morbidity in adulthood. For many the workplace is the main site of exposure. In a pilot study during the past year on 1197 white and blue-collar workers, we found that the proportion of nonsmokers exposed to tobacco smoke at work is very high, almost 80%, and that workers are bothered by it. 2/3 are aware of the serious adverse health effects of tobacco smoke. 98% of the passive smokers and 75% of the active smokers considered legislation to limit smoking in public places justified.

Attitude to Health↗
PubMed1991

Death certificate categorization of malignant pleural and peritoneal mesothelioma in a cohort of asbestos insulation workers.

Accuracy of diagnosis of malignant mesothelioma (pleural and peritoneal) was studied in a cohort of asbestos insulation workers in the United States and Canada. Initial clinical diagnosis, clinical diagnosis at death and death certificate diagnosis were compared with the diagnosis of malignant mesothelioma ascertained by full data review at the Division of Environmental and Occupational Medicine, Mount Sinai Medical Center, New York ('best evidence'). In both groups the death certificate diagnosis was somewhat less frequently accurate than clinical diagnosis at death. Knowledge of the patients' occupational history by the attending physician and its relation to accuracy of diagnosis of malignant mesothelioma is considered.

Asbestos↗
PubMed1991

Physicians' detection of psychological distress in primary-care clinics.

This study investigated the amount of psychological distress reported by 182 soldiers in the Israeli military and compared soldiers' self-ratings of distress with ratings by military physicians of observed distress. Comparisons indicated a low detection rate by physicians with only 13% of self-reported cases of emotional distress identified. This and several related findings were taken to indicate shortcomings in medical care. Possible remedies include additional psychiatric training for military physicians, less frequent rotation of physicians to allow for more stable care, and the initiation of mental health education among soldiers.

Adult↗
PubMed1991

Measuring psychological stress in primary care military medical clinics.

In this study, the amount of psychological distress reported by soldiers is investigated and measured over time. The soldiers--enlisted and career--were randomly chosen while visiting five different military primary care clinics (for ostensible somatic problems) and administered the General Health Questionnaire (Goldberg and Huxley, 1980). A third of the subjects were given the GHQ a year later. Fifty-two percent showed psychological stress: combat soldiers showed considerably less distress than technical/maintenance and administrative soldiers, and the psychological stress findings remained relatively stable over time. Possible explanations for these findings are discussed.

Adult↗
PubMed1990

The effect of repeated doses of 30 mg pyridostigmine bromide on pilot performance in an A-4 flight simulator.

The effect of repeated doses of 30 mg pyridostigmine bromide every 8 h on flight skills in an A-4 simulator was tested in this crossover double-blind placebo-controlled study on 10 pilots experienced in actual and simulated A-4 flights. The pilots flew two test simulator flights 2 h after the fourth dose of pyridostigmine or placebo. The flight profile included navigation, rapid ascent, 360 degrees turns, and instrument landing. Each flight lasted approximately 20 min. Flight parameters measured included indicated air speed, true heading, barometric altitude, vertical velocity, and bank. The mean whole blood cholinesterase inhibition level was 29%. There was no decrement in performance under treatment with pyridostigmine in the percent of deviation time from the prescribed limits or in the average duration or magnitude of the deviation in each of the flight parameters. We conclude that pyridostigmine bromide in repeated doses of 30 mg every 8 h does not appear to influence pilot performance during short A-4 missions.

Adult↗
PubMed1990

Blood pressure response to exercise in normotensive and hypertensive young men.

We attempted to determine the optimal cut-off value of blood pressure defining a hypertensive response to exercise testing in 90 asymptomatic Israeli candidates for flight training with casual resting blood pressure of 140/90 mm Hg or more, and 72 age-matched normotensive controls tested in the Israel Air Force Aeromedical Center. Exercise testing (Bruce protocol) was performed using a calibrated Quinton Treadmill and a Hewlett Packard 151711-A three-channel ECG recording system. Recordings were made at 3-min intervals. At 3 min of exercise 12/87 (14%) of the hypertensive subjects had a SBP of greater than or equal to 210, compared to only 1/71 (1%) of the control group (relative risk 14). At 12 min of exercise 27/51 (53%) of the hypertensives and 9/55 (16%) of the controls had similar elevations of SBP (relative risk 3.3). At 6 min of exercise 11/87 (13%) of hypertensives had SBP greater than or equal to 220, whereas none of the normal controls had SBPs elevated to that degree. We concluded that an increase in SBP to 210 mm Hg or more after 3 min or to 220 mm Hg after 6 min of exercise testing by the Bruce protocol best separates the hypertensive group from the control group. This occurs at the expense of sensitivity. Only appropriate longitudinal studies can compare the degree to which various definitions of the hypertensive response to exercise will predict future hypertension.

Adolescent↗
PubMed1989

Mitral leaflet motion: age and implications for the diagnosis of mitral valve prolapse.

The extent of posterior mitral leaflet motion (PMLM) during systole in relation to age was studied in 300 asymptomatic men aged 18-42 years. PMLM of 4 mm or more on two-dimensional directed M-mode echocardiography was found in 8% (16/200) of subjects under age 35 years, but in only 2% (2/100) of those aged 35 years or more (p less than 0.05). On two-dimensional echocardiography, 16% (31/200) of men under 35 years old had PMLM greater than or equal to 0.40 mm2 compared with 1% (1/100) of those 35 years or more (p less than 0.001). The findings were not related to differences in left ventricular cavity dimensions or in the extent of systolic ventricular contraction. Body mass index (BMI) increased with age, but there was a significant and independent negative correlation of age with PMLM after controlling for BMI. The data are compatible with the hypothesis that the aging process is associated with decreased mobility of the mitral valve or annulus with lesser degrees of backward bowing or billowing of the leaflets during systole. Age should be taken into account in determining "normal" values for mitral leaflet motion.

Adolescent↗
PubMed1989

Systolic tricuspid leaflet prolapse in asymptomatic young men.

The degree of systolic movement of the tricuspid valve (TV) leaflets was measured in 100 consecutive apparently healthy men 18-20 years old at the time of maximum posterosuperior motion toward or into the right atrium. Backward bowing of greater than 0.20 mm2 of the anterior leaflet, and greater than 0.15 mm2 of either the posterior or septal leaflets beyond the plane of the tricuspid annulus was found in 5% or less of the cohort irrespective of the echocardiographic view in which it was recorded. The upper 5% of these young men had greater than 0.80 mm2 of backward bowing when the leaflet motion was summed from all three views. The anterior leaflet demonstrated more bowing than either the septal or posterior leaflets. The systolic TV prolapse area correlated highly with the degree of mitral leaflet prolapse (r = 0.654, p less than 0.001). We conclude that there is a wide continuous spectrum of tricuspid valve leaflet prolapse area in healthy young men. This quantitative approach may help standardize the echocardiographic evaluation of tricuspid leaflet motion.

Adolescent↗
PubMed1989

Retirement of fighter pilots with incidentally detected illnesses: a decision analytic model.

Decisions regarding professional fitness after an incidental detection of a clinical disorder are often problematic. The added risk of an occupational error related to the detected disorder may be smaller than the risk of an error due to lack of experience if a veteran is replaced by a novice. In this paper, we examine the choice between grounding or granting a waiver to an experienced fighter pilot with an incidental finding of premature ventricular contractions. The decision considers the probability of sudden incapacitation during flight and of pilot error-related air accidents in novices and veterans. Although deliberately biased in favor of grounding the veteran, the analysis indicates that the risk of sudden death or incapacitation in an experienced fighter pilot with an incidentally detected illness should be increased ten-fold to 46-fold to justify his or her replacement by a novice. In the specific case considered, the analysis suggests that the risk of an air accident due to sudden death or incapacitation of a veteran with incidentally detected premature ventricular contractions is similar to the estimated added risk of an error-related air accident if she or he is grounded and replaced by a novice. When reliable data on the frequency of human error by age and experience become available, the proposed model may be applied to other situations in which trained professionals develop a potentially disabling disease.

Accidents, Aviation↗
PubMed1989

Amosite mesothelioma in a cohort of asbestos workers.

A cohort of 820 asbestos workers with a short duration of exposure to amosite between 1941 and 1945 was followed. These men were alive five years after starting work and were observed until 1988. Seventeen cases of malignant mesothelioma (eight pleural, nine peritoneal) were found. The mean age at the onset of exposure was 33 years for men with pleural mesothelioma and 30 years for those with peritoneal mesothelioma. Chest pain was the main symptom in pleural mesothelioma and abdominal pain in peritoneal mesothelioma. Open lung biopsy was the most useful diagnostic approach for pleural mesothelioma, whereas for peritoneal mesothelioma it was exploratory laparotomy. Pleural patients died of pulmonary insufficiency, and peritoneal patients of wasting and inanition. In both groups the death certificate diagnosis was less accurate than the clinical diagnosis at death. The mean survival was 12.5 months from first symptom to death for the pleural group and 5.4 months for the peritoneal group.

Adult↗
PubMed1988

Malignant mesothelioma in a cohort of asbestos insulation workers: clinical presentation, diagnosis, and causes of death.

Malignant mesothelioma has been rare in the general population. In recent decades its incidence has risen dramatically, parallel to the increasing use of asbestos in industry since 1930. Altogether 17,800 asbestos insulation workers, members of the International Association of Heat and Frost Insulators and Asbestos Workers (AFL-CIO-CLC) in the United States and Canada, were enrolled for prospective study on 1 January 1967 and followed up to the present. Every death that occurs is investigated by our laboratory. One hundred and seventy five deaths from mesothelioma occurred among the 2221 men who died in 1967-76 and 181 more such deaths in the next eight years. Altogether, 356 workers had died of malignant mesothelioma (pleural or peritoneal) by 1984. Diagnosis of mesothelioma was accepted only after all available clinical, radiological, and pathological material was reviewed by our laboratory and histopathological confirmation by the pathology unit made in each case. One hundred and thirty four workers died of pleural and 222 of peritoneal mesothelioma. Age at onset of exposure, age at onset of the disease, and age at death were similar in both groups of patients. Significant difference was noted only in the time elapsed from onset of exposure to the development of first symptoms, which was longer in the group with peritoneal mesothelioma. Shortness of breath, either new or recently increased, and chest pain were the most frequent presenting symptoms in the group with pleural mesothelioma; abdominal pain and distension were frequent in the patients with peritoneal mesothelioma. Pleural effusion or ascites were found in most patients. The most effective approach to the diagnosis of malignant pleural mesothelioma in these cases was by open lung biopsy; exploratory laparotomy was best for diagnosing peritoneal mesothelioma. Patients with pleural mesothelioma died principally from pulmonary insufficiency whereas those with peritoneal mesothelioma succumbed after a period of pronounced wasting.

Adult↗
PubMed1988

Isolated tricuspid valve prolapse.

Tricuspid valve prolapse is commonly associated with mitral valve prolapse or other heart abnormalities and is rarely found as an isolated finding. A patient with isolated tricuspid valve prolapse is described which was discovered on routine examination of an asymptomatic pilot.

Adult↗