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Biomedical subjects

S Melamed

Publications and source records attributed to S Melamed.

143 records · Page 8Linked to original sources
PubMedDate not supplied

Molteno implant surgery in refractory glaucoma.

In recent years aqueous drainage implants have become a useful adjuvant in the treatment of refractory glaucomas. The Molteno implant is one of the most widely used devices for providing a permanent channel of aqueous flow from the anterior chamber to a collecting reservoir in the posterior subconjunctival space. Recently, modifications in design and surgical technique of the Molteno implant have enhanced its success rate, with a reduction in complications such as prolonged hypotony, anterior chamber flattening, and tube-corneal touch. These modifications include intracamerally injecting hyaluronic acid, using a needle track to provide an opening into the anterior chamber for the tube, performing the operation in two stages, using a double plate, temporarily ligating the tube, using a donor scleral patch, and giving adjunctive antifibrotic therapy. The rationale for application of the Molteno implant, the indications, techniques, results, and complications are described.

Aqueous Humor↗
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Acute and chronic effects of noise exposure on blood pressure and heart rate among industrial employees: the Cordis Study.

The effects of industrial noise on resting heart rate and blood pressure were studied in 3,105 blue-collar workers. Heart rate and blood pressure were measured in different workers at various times during the workday. After controlling for several possible confounders, we found that resting heart rate in females was associated positively with noise intensity (p = .036) and with time of day (p = .054). In males, resting heart rate was associated with noise intensity; however, such association was related to time of day (p = .046). No such associations were found for blood pressure in either sex. We plotted the mean resting heart rate by time of day for workers exposed to high [ > or = 80 db(A)] and low noise, and no difference was evident with respect to morning heart rate in either sex. After 4 h of noise exposure for males (and less time for females), individuals who were exposed to high noise had higher heart rates; however, in females this was not observed at the end of the workday. Thus, recurrent daily exposure to high noise at work has an acute, though not residual, effect on resting heart rate.

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

Emotional reactivity and elevated blood pressure.

Following findings of cardiovascular hyperactivity to stressful stimuli among hypertensive patients, a psychologic construct of Emotional Reactivity (ER) was formulated as a possible intervening variable. ER was conceived as a tendency to enter an emotional state characterized largely by the extension of psychologic representation of stressful stimuli after their actual termination. The emotionally reactive person was defined as one who experiences intrusive-repetitive images and thoughts following emotional events, lacks control over the tendency to become emotionally aroused despite conscious attempts to do so, becomes emotionally aroused in anticipation of forthcoming emotional events, and experiences excessive magnitude and/or duration of emotional response following an emotional event. Based on these features, a scale measuring ER was developed. The scale was found to be reliable and showed test-retest stability over 1 year. The study population included 837 subjects, divided into controls and those with elevated blood pressure (BP), either systolic (greater than or equal to 140 mm Hg) or diastolic (greater than or equal to 90 mm Hg), on the basis of site measures conducted in the workplace; subjects already receiving antihypertensive medication were included in both the latter groups. The results showed that subjects with elevated systolic BP (SBP) scored significantly higher on the ER scale than the controls and this was true for both sexes. Females with elevated SBP had higher ER scores than males, and this was particularly true for those over 40. Control subjects with a history of familial hypertension scored higher on the ER scale than controls without such a history.

Adult↗
PubMedDate not supplied

Type A behavior, tension, and ambulatory cardiovascular reactivity in workers exposed to noise stress.

Recent negative findings regarding differences in blood pressure (BP) and heart rate (HR) reactivity at work between Type A and Type B workers may stem from the failure to note the stressors to which they were exposed. In this naturalistic study, an objective work stressor--varying levels of ambient noise--was individually monitored among 123 normotensive males. We examined the relationship of Type A behavior (assessed by the Thurstone Temperament Schedule) to ambulatory BP and HR reactivity under high and low noise conditions. We also tested the hypothesized mediating function of tension arousal. Results of multiple regression analyses indicated that when workers were exposed to high noise levels (> or = 80 dB(A)), Type A behavior was positively related to diastolic BP (p = 0.029) and HR reactivity (p = 0.0001), even after adjusting for clinic values, time of measurement, worker activities, and body position during measurement. When the same workers were exposed to low noise levels, the results were not significant. This suggests that noise constitutes a stressor for Type A individuals, and highlights the importance of noting the actual stressor-exposure condition. In addition, Type A individuals reported high tension, noted concurrently with the ambulatory measurements. Tension arousal was also related to BP and HR reactivity. Adding the tension variable to the above regressions weakened the relationship between Type A behavior and BP and HR reactivity. Thus, the tension experienced by Type A workers exposed to noise stress may have served as a mediator of cardiovascular reactivity.

Adult↗
PubMedDate not supplied

Emotional reactivity, defensiveness, and ambulatory cardiovascular response at work.

OBJECTIVE: To examine whether individual differences in dispositional emotional reactivity (ER), denoting a proneness to sustained emotional arousal in the face of stressful events, are associated with tension arousal and cardiovascular (CV) response at work, and whether this association is modified by defensive coping. METHOD: Eighty-two male normotensive industrial workers participated in the study. ER was measured by the Emotional Reactivity Scale (Melamed, 1994). Defensive coping was identified by high scores on the Marlowe-Crowne Social Desirability Scale. Ambulatory blood pressure (BP) was recorded concurrently with tension feelings during a typical workday. RESULTS: ER was positively associated with systolic BP (p = .04) and diastolic BP (p = .0009) response at work, whereas defensiveness was negatively associated with both systolic BP (p = .0001) and diastolic BP (p = .04) response. This was true even after controlling for several potent determinants of ambulatory BP. No interactive effect was found between ER and defensiveness on BP response at work. High emotional reactives (ERS) had a higher proportion of tension reports during work than low ERS (p < .0001); this also applied to low defensive compared to high defensive individuals (p < .0001). ER and defensiveness interacted to affect baseline (clinic) diastolic BP. The lowest values were observed in true low (nondefensive) emotional reactives (ERS). Defensive/low ERS (repressors) had elevated BP, similar to the high (nondefensive)/ERS. Defensive/ high ERS had an intermediate BP level. CONCLUSIONS: Both high ER and low defensiveness were independently shown to be effective in identifying persons who might display recurrent tension arousal and pressure responses at work as well as high baseline BP values. When considering both baseline and ambulatory BP values, nondefensive/high ERS appear to be at greatest CV risk.

Adaptation, Psychological↗
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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

Association between burnout at work and leukocyte adhesiveness/aggregation.

OBJECTIVE: This study examined whether burnout at work is associated with leukocyte adhesiveness/aggregation (LAA), a phenomenon known to be affected by stress. METHODS: The LAA levels of 179 employees (68 men and 111 women) of Tel Aviv University were determined when the employees underwent their annual routine medical checkup. Blood pressure and toxic chemical exposure were also measured, and background data were retrieved from medical records. Information on burnout and somatic complaints (known to be a general marker of stress) was collected through a self-report questionnaire. RESULTS: Total burnout and each of its subcomponents, emotional exhaustion, chronic fatigue, and cognitive weariness, was significantly associated with LAA levels, even after controlling for age, sex, and educational level. Burnout and somatic complaints intercorrelated positively, but somatic complaints were not significantly associated with LAA levels before or after controlling for the above possible confounders. CONCLUSIONS: Burnout was positively associated with LAA levels. This finding is consistent with the growing evidence of the negative impact of burnout on physical health. The lack of an association between somatic complaints and LAA levels reinforces the claim that burnout and stress are two different concepts.

Adult↗
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Acceptance of disability, work involvement and subjective rehabilitation status of traumatic brain-injured (TBI) patients.

A follow-up of 78 TBI patients one to two years after discharge from rehabilitation hospital supported hypothesized correspondence between work involvement and subjective rehabilitation status (SRS). Subjective rehabilitation was defined as the gratification of basic needs: physical well-being, emotional security, and family, social, economic, and vocational needs. Highest SRS was found among patients employed in the open market. Lower SRS was found in patients employed under protected conditions who also reported their work to be much less congruent with their expectations. Unemployed patients living active lives reported higher SRS than unemployed patients living passive lives, but both showed lower SRS than employed patients. Both work involvement and SRS were found to be related to acceptance of disability (AD). However, longitudinal data are needed to ascertain whether AD precedes or follows the other two variables. Both possibilities may be correct.

Activities of Daily Living↗
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Personal determinants of health promoting behavior.

This paper describes the personal determinants in health promoting behavior, and, in particular, life style changes. A review is made of internal factors, including personality factors, health beliefs, and health attitudes. Environment factors are also taken into account. Suggestions for future research are proposed.

Attitude to Health↗
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Noise exposure, noise annoyance and their relation to psychological distress, accident and sickness absence among blue-collar workers--the Cordis Study.

This study examined the impact of chronic industrial noise exposure on psychological distress symptoms, accident involvement and sickness absence among male and female workers. It also examined whether workers expressing high noise annoyance were more adversely affected by it. Subjects were blue-collar workers, 1,680 males and 688 females, who participated in the Cordis Study. Noise exposure levels were: low [< 75 dB(A)], moderate [75-84 dB(A)], and high [> or = 85 dB(A)]. For males, noise exposure level affected job dissatisfaction and post-work irritability, while for females it also intensified somatic complaints, anxiety and depression. All the distress symptoms were higher for females. Further analysis showed that the significant increase of symptoms with noise exposure level was only for workers reporting high annoyance. Higher noise exposure levels were associated with increased accidents and sickness absence for both sexes. Noise-annoyed males had a significantly higher percentage of accidents when exposed to moderate noise levels and a marked increase in sick leave at high noise levels. Finally, the nonauditory effects studied here were already prevalent at moderate noise exposure levels, especially among noise-annoyed workers. This indicates the importance of reducing even moderately high levels of industrial noise not usually considered harmful to hearing.

Absenteeism↗
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Association of silent ST-segment depression on one-hour ambulatory ECGs with exposure to industrial noise among blue-collar workers in Israel examined at different levels of ambient temperature--the CORDIS Study.

BACKGROUND: Epidemiologic studies on the effects of ambient temperature or industrial noise on the cardiovascular system have usually focused on blood pressure. However, the ambulatory ECG may be a sensitive instrument for evaluating transient changes in the myocardium associated with exposure to such environmental stressors. In particular, the presence of silent ST-segment depression would strongly suggest transient myocardial ischemia. AIM: To evaluate a possible association between exposure to ambient noise and temperature in the workplace and silent ST-segment depression on short-term ambulatory ECGs. METHODS: Between 1985 and 1987, approximately 6,000 factory workers in Israel were examined in the framework of the CORDIS study. Each worker underwent ambulatory ECG monitoring for one hour. Measurements were taken of the average exposure to noise and the ambient temperature. Complete data including analysis of the ST-segment on the ambulatory ECG were available for 3,747 blue-collar workers. RESULTS: After excluding subjects with a history of heart disease, among men, silent ST-segment depression was found to be most prevalent in those workers exposed to more than 80 dBA compared with those exposed to less than 70 dBA. (RR = 2,4, p = .1 for men and RR = 1.3, p = .37 for women. Silent ST-segment depression was more prevalent at ambient temperatures up to 20 degrees C than over 25 degrees C (RR = 1.4, p = .22 for men and RR = 2.0, p = .005 for women). These trends persisted after controlling for possible confounding variables, such as age, type of work, smoking, and relative weight; however, only the temperature effects in women remained statistically significant. CONCLUSIONS: These findings suggest that silent ST-segment depression on ambulatory monitoring may be a sensitive measure of the cardiovascular response to exposure to physical stressors in the workplace. Exposures to noise and varying ambient temperature appear to have different effects on men and women.

Adult↗
PubMedDate not supplied

Retinal involvement in tuberous sclerosis.

In two infants hospitalized at the ages of three and one-half months and 11 months because of epileptic seizures, the diagnosis of tuberous sclerosis was reached upon the basis of retinal astrocytomas found in the fundus examination. It is recommended that indirect ophthalmoscopy be performed in all infants and young children referred with signs possibly related to this disease.

Astrocytoma↗
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Use of the giant-pulse Nd:YAG laser for ab-externo sclerostomy in rabbits and humans.

The giant-pulse Neodymium:YAG laser, a recently developed laser source, delivers up to 200 W of peak power at pulse widths of 20 or 40 msec. The instrument can create a sclerostomy with minimal surrounding damage and, consequently, relatively little postsurgical inflammation and scarring. We tested its efficacy in performing ab-externo sclerostomy in 10 adult pigmented rabbits and in five patients with end-stage glaucoma. All of the animal eyes were hypotonus immediately after the procedure. However, the intraocular pressure increased gradually, and by the third day, returned to presurgical levels in all of the eyes. All five of the glaucoma patients treated had patent sclerostomies following the procedure. They all had early hypotony, but after 3 months, four of the five sclerostomies apparently failed. The giant-pulse Nd:YAG laser appears useful for performing sclerostomy, but modifications are needed to solve the problems of early hypotony and late closure of the fistulula.

Animals↗