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Biomedical subjects

J Ribak

Publications and source records attributed to J Ribak.

At least 127 records · Page 7Linked to original sources
PubMed1985

The association of age, flying time, and aircraft type with hearing loss of aircrew in the Israeli Air Force.

Exposure to aircraft (A/C) noise is considered to be one of the factors which causes permanent hearing threshold shifts among military aircrew. Consequently most studies, dealing with this field of evaluation, fail to focus on the contribution of other elements, especially biological (physiological) ones. We, therefore, decided to evaluate the effect of the subject's age on this process. Audiometric records of 777 aircrew members within the Israeli Air Force were examined. The average age was 27.2 +/- 5.2 years. The individual files were composed of all yearly audiograms from time of recruitment to present, personal information, recorded flight time and type of A/C flown (i.e., rotary-wing and fighter, transport and light fixed-wing aircraft). Hearing loss was studied using two criteria (a. USAF criteria; b. acoustic trauma criteria we devised). The significance of each of the factors was analysed by using uni- and multivariate analysis (Pearson correlation and stepwise multiple regression). A progressive linear correlation between age and hearing loss was exhibited (p less than 0.001). The results suggest that the age of the subject is strongly correlated with values of hearing threshold shift, while A/C type and accumulated time played a minor role.

Adolescent↗
PubMed1984

Significance of microhaematuria in young adults.

The medical records of 1000 asymptomatic male air force personnel were examined retrospectively for the results of 15 yearly examinations of urinary sediment. The study covered the period 1968-82, beginning with the subjects aged 18-33 years. The cumulative incidence of two to four or more red blood cells per high power field found at one or more examinations was 38.7% after an average of 12.2 yearly examinations per person. In 161 subjects two to four or more red blood cells per high power field were found at two or more yearly examinations within a five year period. Intravenous pyelography in 58 cases disclosed asymptomatic nephrolithiasis in six. Cystoscopy performed in 11 cases identified one patient with urethritis, one with a vesical calculus, and one with transitional cell carcinoma of the bladder. Two years before diagnosis the patient with carcinoma had had a single transient finding of 10-12 red blood cells per high power field which was not investigated further. Cystoscopy was performed after an episode of macroscopic haematuria. Renal biopsy in one subject with recurrent microhaematuria and trace proteinuria disclosed focal glomerulonephritis. None of the remaining subjects with microhaematuria developed hypertension or proteinuria, and at the end of the study period all were active and free of urinary symptoms. The observed cumulative incidence of urological neoplasms at 15 years (0.1%) was consistent with that expected in Israeli men aged 18-40 (0.09%). Hence microhaematuria detected during a screening examination probably should not be regarded as a specific sign of a significant lesion and does not of itself warrant urological investigation in adults aged 40 or less.

Adolescent↗
PubMed1984

Lytic spondylolisthesis in helicopter pilots.

Trauma to the back from the force of chronic stress is thought to be an etiologic factor in isthmic spondylolisthesis (SLL). The relationship of first degree spondylolisthesis to low back pain (LBP) is controversial. We compare the prevalence of SLL in helicopter pilots who are subject to strong vibrational forces, with other airforce personnel. Helicopter pilots had more than a four times higher prevalence of SLL (4.5%) than did cadets (1.0%) and transport pilots (0.9%). Low back pain was more frequent in pilots with SLL than in those without this lesion but in no case was the pain disabling or the defect progressive. We conclude that SLL may be induced by vibrational forces and although SLL is associated with LBP, the pain was little clinical significance.

Adolescent↗
PubMed1984

Transdermal therapeutic system scopolamine (TTSS), dimenhydrinate, and placebo--a comparative study at sea.

The efficacy of transdermally administered scopolamine was compared with the efficacy of oral dimenhydrinate and placebo therapy in the prevention of motion sickness at sea. Medication was administered on a controlled double blind basis to 140 subjects. A placebo effect reduced the motion sickness incidence (MSI) from 57.69% in the control group to 43.47%. Administration of dimenhydrinate reduced the MSI to 22.22% and the use of Transdermal Therapeutic System Scopolamine (TTSS) further reduced the MSI to 16.66%. TTSS afforded 61.67% protection against motion sickness at sea, compared to 48.88% protection with dimenhydrinate.

Administration, Topical↗
PubMed1983

Predictive value of systolic blood pressure in young men for elevated systolic blood pressure 12 to 15 years later.

Systolic blood pressure (SBP) was determined annually for 12 to 15 years in 719 men, 18 to 30 years old at entry into the study. SBP values at entry were compared with those measured in the same individuals at the end of the follow-up period. The cutoff point separating "normal" from "elevated" SBP was arbitrarily set at 140 mm Hg. The highest SBP recorded at entry was 170 mm Hg. Elevated SBP on follow-up was 2.3 times more common among subjects with elevated SBP at entry. Yet, 89.2% of the subjects with elevated SBP at entry had a normal SBP on follow-up. A normal SBP at entry did not reduce the risk of elevated SBP on follow-up.

Adolescent↗
PubMed1983

Timolol maleate: side effects on healthy nonglaucomatous volunteers.

As the number of military pilots over the age of 40 increases, open-angle glaucoma becomes an important aeromedical problem. Epinephrine ophthalmic solution is the only antiglaucomatotic agent in use among flying personnel. Timolol maleate, a new antiglaucomatotic agent, is a nonselective beta-blocker. This drug has a potent hypotensive effect on intraocular pressure with a minimal effect on visual functions. Our data show that it significantly decreases the pulse rate and may eventually be a basis for cardiac dysrythmias.

Adrenergic beta-Antagonists↗
PubMed1983

Diurnal rhythmicity and Air Force flight accidents due to pilot error.

In order to evaluate the possible role of an endogenous rhythmic factor in Air Force flight accidents a retrospective study was carried out. The study included all Air Force (aircraft) flying accidents which have been attributed to pilot's error and which occurred, in peace time missions, over a period of 12 years (1968-1980). The frequency of hourly accidents was computed separately, for each year, for each month, for each day of the week, and for each calendar day. Identical computations were carried out for the frequency of hourly flights. When the hourly ratios of these two parameters were computed, by dividing the value of one parameter to the other at each hour, a rhythmic (rather than constant) diurnal pattern was obtained. The pattern was defined as the "Hourly Accident Coefficient (HAC)". The HAC values ranged from 1.58 to 0.68 (pooled data for all surveyed aircrafts) and from 4.12 to 0.74 (data for fighter planes). The pattern, which exhibited a diurnal rhythm, was independent of the frequency of flights and appeared to be related to the sleep-wake cycle of the pilots, especially to the time of waking from the night sleep. The results are used as a directive for a progressive study aimed at evaluating the practical implications of the presented observations.

Accidents, Aviation↗
PubMed1982

Altitude and hypoxia as phase shift inducers.

The daily fluctuations in the levels of some physiological and performance parameters have been assessed in three young subjects. The assessment was carried out before and after exposing them to the combined effect of two stressors, reduced barometric pressure and hypoxia. The exposure was effectuated by a simulated flight in a low pressure chamber for 30 min. The measured altitude in the chamber was 25000 ft (7620 m). During the simulated flight, each of the individuals experienced 2-3 min of hypoxia. The examined parameters (oral temperature, peak expiratory flow, grip strength, 2 and 6 digits recognition test, addition, counting backward, and odd-even addition test) exhibited circadian rhythms whose acrophases shifted significantly after exposure to the combined effect of the two stressors. The phases continued to shift for 4 d in a concordantly synchronized pattern. On the fourth day, they exhibited a tendency to resume their original phase.

Adult↗
PubMed1976

Risk factors in ulcerative colitis.

In 504 Jewish patients with ulcerative colitis the following risk factors were evaluated: sex, age at onset of disease, community group, extent of disease, and duration of disease. The disease was more severe in females. Severe attacks, weight loss, iron deficiency, liver disease and arthritis were significantly more frequent in females than in mles. Mortality was higher in patients who contracted the disease above age 50. The disease appeared to be more severe in patiets of Ashkenazi origin as compared to Orientals. The difference failed to reach statistical signifcance except for mortality. We confirmed the well-known adverse effect of extensive colonic involvement. Severe attacks, a severe course of the disease and extensive colonic involvement are more frequent with increasing duration of the disease.

Adolescent↗
PubMed1976

Ulcerative colitis in the Jewish population of Tel-Aviv Yafo. III. Clinical course.

The clinical course of ulcerative colitis has been studied and analyzed in 504 Jewish patients in the Tel Aviv area. The length of follow-up was 1 to 46 years, with a mean of 7.8 years. The data are compared with other published series of the disease in different geographical areas. Differences in the incidence of serveral complications are noted. The trend in recent years toward a lesser mortality associated with the disease is discussed.

Colitis, Ulcerative↗
PubMedDate not supplied

Relationship of blood lead levels to blood pressure in battery workers.

The effect of lead exposure on blood pressure in the modern industrial setting is controversial. In this study, we followed 67 workers in a lead-battery plant for 6-10 y, and blood pressure and blood lead levels were measured every 6 mo. Weight, height, alcohol intake, cigarette smoking, and age were recorded. Partial correlation coefficients showed that initial systolic blood pressure, age, and body mass index (i.e., weight/height squared) accounted for 25%, 30.9%, and 20.2%, respectively, of the variance in systolic blood pressure (p < .001 in all cases). Conversely, average blood lead levels (13 +/- 3 tests/worker) accounted for only 0.4% of the variance (not significant). Repeated-measures analysis of variance showed a small--but significant--association between blood lead levels and systolic blood pressure. There was a negative correlation between blood lead levels and diastolic blood pressure. There were 18 men with average blood lead levels that were less than 30 micrograms/dl (average = 25 +/- 3 micrograms/dl), and 32 men had levels of 40 micrograms/dl or more (average = 47 +/- 6 micrograms/dl). The mean final systolic blood pressure, adjusted for age, and initial systolic blood pressure were 117 +/- 13 mm Hg and 114 +/- 11 mm Hg, respectively. We concluded that blood lead levels had no clinically significant effect on blood pressure in lead-battery workers. The main predictors of the follow-up systolic blood pressure were age, body mass index, and initial systolic blood-pressure measurements.

Adult↗
PubMedDate not supplied

Industrial noise exposure, noise annoyance, and serum lipid levels in blue-collar workers--the CORDIS Study.

Chronic noise exposure may constitute a risk factor for cardiovascular disease, but the exact mechanism is unclear. The authors studied the association between industrial noise exposure, noise annoyance, and serum lipid/lipoprotein levels in male (n = 1,455) and female (n = 624) blue-collar workers. The authors found that young men (i.e., < or = 44 y of age) exposed to high noise levels (> or = 80 dB[A]) had higher total levels of cholesterol (p = .023) and triglycerides (p = .001), as well as a higher cholesterol ratio (p = .038), than men exposed to low noise levels, even after controlling for confounding variables. In women or in older (> 45 y) men, noise did not affect serum lipid/lipoprotein levels. The authors found no interaction between noise exposure level and noise annoyance (except for high-density lipoprotein in women). However, noise annoyance covaried independently with total cholesterol (p = .022) and high-density lipoprotein (p = .0039) levels in young men and with total cholesterol (p = .035), triglyceride (p = .035), and high-density lipoprotein levels in women (under high noise exposure conditions)(p = .048) levels in women. Noise annoyance and noise exposure levels had an additive effect on cholesterol levels. Young men who scored high on both variables had a 15-mg/dl higher mean cholesterol level (95 % confidence interval [CI] = 7.2, 22.8; p = .0003) than those who scored low on both variables; in women, the corresponding difference was 23 mg/dl (95% CI = 1.5, 42.9; p = .019). The authors concluded that the examination of serum lipid/lipoprotein levels may be useful in studies of the health effects of noise, and particular attention should be paid to noise-annoyed individuals.

Adult↗
PubMedDate not supplied

Health responsibility and workplace health promotion among women: early detection of cancer.

The importance of health responsibility as one aspect of a health-promoting lifestyle has been emphasized repeatedly. Yet there are only a few empirical studies of its role in preventive behavior. We examined the relationship between health responsibility and early-detection practices for breast and cervical cancer. A group of 253 women employees of a large industrial company participated in a cancer screening program subsidized by the employer. They completed questionnaires assessing health responsibility and reported early-detection practices: frequency of breast self-examination and physician breast examinations, frequency of Pap tests, and time lapsed since last Pap test and breast examinations. Health responsibility was a significant independent predictor of breast examination indicators but not of Pap tests. Education level was an important predictor for Pap tests, and age predicted most early-detection practices. The findings lend some support to the role of health responsibility in initiating breast examinations. Better prediction of early-detection practices could be achieved by adding cognitive and emotional components to the existing responsibility scale and by distinguishing between retrospective and prospective responsibility.

Adult↗
PubMedDate not supplied

Association between somatic symptoms and 24-hour ambulatory blood pressure levels.

OBJECTIVE: To clarify whether somatic complaints in healthy normotensive men are associated with differential 24-hour blood pressure and heart rate measures. METHOD: Twenty-four-hour ambulatory systolic and diastolic blood pressure was monitored in 114 healthy normotensive men, aged 28 to 63 years, engaged in similar physical work. Means were calculated for each hour, for the whole 24-hour period, and for daytime, nighttime, and work time. Subjects were interviewed about somatic complaints, demographic data, and health habits, and body mass index was measured. RESULTS: After controlling for possible confounders, a positive association was found between the somatic complaint score and 24-hour, diurnal, and work-time systolic blood pressure (p = .014, p = .007, and p = .008, respectively). The association with casual systolic blood pressure was of borderline significance (p = .089). There was a positive trend, which did not reach statistical significance, in the relationship between somatic complaint score and all measures of diastolic blood pressure. Diurnal, 24-hour, and work-time heart rates were highest in the subjects with the highest somatic scores (p < .01 for all trends). CONCLUSIONS: In healthy normotensive men, somatic complaints are associated with an increased cardiovascular load. The effects of this increase on long-term cardiovascular morbidity and mortality are uncertain and warrant additional study.

Adult↗
PubMedDate not supplied

Smoking, diet, and health behaviors among lead-exposed blue-collar workers.

The objectives of the study were to compare dietary intake by smoking levels in blue-collar Israeli workers occupationally exposed to lead and thus identify additional areas for health-enhancing intervention in addition to smoking cessation. One hundred and eighty-seven male industrial employees who were exposed to lead through their work were screened at the worksite to evaluate health status and dietary intake. Smokers had higher intakes of fat, cholesterol, calcium, riboflavin, and vitamin E per day. They were consuming more meat and high-fat dairy products. Dose-response relationships were shown for fat and energy intake by smoking level. Thus, smoking is associated with other adverse health behaviors. When conducting epidemiologic or occupational studies, analyses should include adjustment for the fact that the lifestyles of smokers may also be unhealthy in other ways.

Adult↗
PubMedDate not supplied

The consequences of passive smoking: an overview.

Tobacco smoke contains a wide range of toxic vapors and particles that when inhaled are injurious 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 the problems involved 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 benign and malignant pulmonary morbidity. There is an increased risk of cardiovascular and lung diseases among people living with spouses who smoke due to the exposure to tobacco smoke in the home. Passive smoking during pregnancy constitutes a health hazard for mother and fetus alike. Exposure to passive smoking during childhood may predispose the individual to benign and malignant pulmonary morbidity in both childhood and adulthood. For many people the worksite comprises the main exposure source. Many clinical conditions are further aggravated by exposure to a combination of tobacco smoke and industrial chemicals, mineral dust, or other carcinogens (asbestos, cadmium, radon daughters). Tobacco smoke exposure and the resultant morbidity can be reduced by regulations and legislation prohibiting smoking in public places and worksites.

Cardiovascular Diseases↗