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Biomedical subjects

L Bernstein

Publications and source records attributed to L Bernstein.

At least 217 records · Page 12Linked to original sources
PubMed1985

Respiratory effects of borax dust.

The relation of respiratory symptoms, pulmonary function, and abnormalities of chest radiographs to estimated exposures of borax dust has been investigated in a cross sectional study of 629 actively employed borax workers. Ninety three per cent of the eligible workers participated in the study and exposures ranged from 1.1 mg/m3 to 14.6 mg/m3. Symptoms of acute respiratory irritation such as dryness of the mouth, nose, or throat, dry cough, nose bleeds, sore throat, productive cough, shortness of breath, and chest tightness were related to exposures of 4.0 mg/m3 or more, and were infrequent at exposures of 1.1 mg/m3. Symptoms of persistent respiratory irritation meeting the definition of chronic simple bronchitis were related to exposure among non-smokers. Decrements in the FEV1 as a percentage of predicted were seen among smokers who had heavy cumulative borax exposures (greater than or equal to 80 mg/m3 years) but were not seen among less exposed smokers or among non-smokers. Radiographic abnormalities were uncommon and were not related to dust exposure. Borax dust appears to act as a simple respiratory irritant and perhaps causes small changes in the FEV1 among smokers who are heavily exposed.

Acute Disease↗
PubMed1985

Influence of coronary collateral blood flow on the development of exertional ischemia and Q wave infarction in patients with severe single-vessel disease.

The functional significance of coronary collateral flow from a nonobstructed supply artery was studied in 121 patients with severe (greater than or equal to 80%) single-vessel disease, 64 with and 57 without Q wave infarction. All patients underwent exercise thallium imaging and coronary angiography. On angiography, collateral flow was present in 85% of 74 occluded arteries compared with only 17% of 47 arteries with subtotal obstruction (p less than .001). Collateral flow was not seen in arteries with lesions of less than 90% obstruction. Collateral flow was present in 100% of 29 occluded arteries in patients without Q wave infarction compared with only 76% of 45 occluded arteries with Q wave infarction (p less than .005). Clinical variables did not correlate with collateral flow. Collateral flow did not prevent ischemia on exercise thallium imaging in patients without Q wave infarction: 30 of 33 (91%) with collateral flow had reversible thallium defects compared with 24 of 24 (100%) without collateral flow (p = NS). In patients with Q wave infarction, partially reversible exercise thallium defects (peri-infarctional ischemia) were more common with flow to the area from either subtotal obstruction (73%) or collateral flow (45%) than with no flow from total occlusion (27%; p = .05). In patients with severe single-vessel disease the presence of collateral flow is principally determined by coronary occlusion. Collateral flow may protect from Q wave infarction but does not prevent exercise ischemia on thallium imaging.

Adult↗
PubMed1985

Uses of a cancer registry in the assessment of occupational cancer risks.

Five approaches for the evaluation of occupational factors in cancer etiology are described. These approaches, based on one's having access to cancer registry data, are for examining cancer profiles for industry and occupation, evaluating information on occupation and industry to infer exposure, observing time trends in incidence to evaluate tumors of occupational interest, using cases of interest to form the basis for case-control studies, and linking cohorts with known exposure to the tumor registry to ascertain cancer incidence in that cohort.

Adult↗
PubMed1985

Medical and dental x rays as risk factors for recently diagnosed tumors of the head.

We used epidemiologic data on 2 tumor sites, the intracranial meninges and the parotid gland, to evaluate the importance of medical and dental x rays as risk factors for radiogenic tumors of the head diagnosed among residents of Los Angeles County in recent years. Exposures to x-ray treatment to the head and to full-mouth dental x-ray series before 1960 appear to be risk factors for both meningiomas and parotid tumors. Evidence from both descriptive and analytic studies suggests that the female over male excess of meningiomas, which is greatest from ages 25 to 54 years, may be partially explained by the excess exposure of young women to dental x rays. Study participants' ability to recall diagnostic x rays accurately is also evaluated by our comparisons of interview data to those available from dental charts. Recall of these events appears to be unbiased and accurate enough to justify the use of interview data in investigations of these risk factors.

Adult↗
PubMed1985

Religion and cancer in Los Angeles County.

The patterns of cancer risk by religion in the large multidenominational population of Los Angeles County were examined with the method of proportional incidence. Risk estimates for individual cancers by religion were screened and those extreme but stable estimates found were reexamined in light of relative socioeconomic class, nativity, and ethnicity. Within Protestant denominations, gradients which can still best be attributed to religious preference were observed for leukemia, stomach, and cervix cancer. Roman Catholics tend to have high risks of stomach and gallbladder and a low risk of prostate cancer, whereas Eastern Orthodox women trade high risk of stomach cancer for low risk of endometrial and lung cancer. The most extreme pattern of risk, that for Jews, is comprised of lowered risk for cervical cancer and for most sites usually associated with smoking, plus consistently higher risk for lymphomas, thyroid cancer, and bladder cancer among males. Like Jews, Seventh-Day Adventists experience high risk for lymphoma and low risk for cervical and respiratory cancers. Risk to Mormons in Los Angeles differs from that of the standard Protestant population in only minor and inconsistent ways. Neither Mormons nor Adventists showed the previously reported deficits of colorectal or breast cancer. Although the method of proportional incidence may be partly responsible for our failure to confirm previous findings, nonreligious cultural or methodologic factors in the original investigations also provide plausible explanations. More generally, associations of the modest magnitude observed between cancer risk and religion in American populations should probably not be attributed to religious life-style, unless extraordinary circumstances permit the exclusion of other determinants.

California↗
PubMed1985

Cancer in Hispanics in Los Angeles County.

Using ethnicity of surname, nativity, residential social class, and inferred age at migration to characterize and subdivide Hispanics in Los Angeles, we compared risk ratios and proportional incidence ratios to examine the patterns of occurrence of selected neoplasms within the Hispanic community. Common neoplasms for which Hispanics have high, low, and intermediary risk were examined in detail. Although the patterns expected on the basis of current concepts of etiology were generally found and served to reinforce presumptions about the biologic significance of the risk factors, a number of observations cannot be explained easily with current knowledge. The risks for stomach and bowel cancers do not conform to the mirror-image patterns to be expected on the basis of inverse patterns of dietary acculturation. Incidence of cancer of the breast, in contrast to that of cervix, does not appear to reflect early cultural practice. Consistent details in the patterns of cancers of the bladder, rectum, ovary, prostate, and possibly pancreas imply unrecognized determinants of disease. Gallbladder cancer in Hispanic women is the disease most closely tied to Hispanic origin or culture, or both, but the ethnic pattern in women differs greatly from that in men.

California↗
PubMed1985

Estrogen and sex hormone-binding globulin levels in nulliparous and parous women.

The hormone profiles of nulliparous and parous women on day 11 of their menstrual cycle have been studied in an attempt to seek evidence for the hormonal basis of the protective effect of first birth on breast cancer risk. A previous publication reported that there were significantly lower (26%) early morning prolactin levels in parous women as compared to those levels in nulliparous women but that there were no differences in plasma and urinary estrogen levels. The present study shows, however, that parous women had significantly shorter cycle lengths than nulliparous women of the same age, and the data were reevaluated with this difference being taken into account. After adjustment for cycle length (within the range of 24-32 days) and age, estrogen levels were significantly lower (22%) in parous women compared to those in nulliparous women. Two further aspects of estrogen metabolism were measured in the plasma samples of these women: the binding capacity of sex hormone-binding globulin (SHBG) and the percentage of free estradiol (E2). SHBG levels were 12% higher in parous women, but there was no difference in percentage of free E2. In the previous publication it was suggested that the protective effect of first birth on breast cancer risk was mediated in part by permanently lowering prolactin levels. The current findings suggest that changes in estrogen metabolism also are a factor.

Adult↗
PubMed1985

Asymptotically efficient two-step estimators of the hazards ratio for follow-up studies and survival data.

Asymptotically efficient estimators of a common hazard rate ratio (for follow-up studies) and the proportional hazards ratio (for survival studies) are obtained by a single iteration of the "Mantel-Haenszel" estimator appropriate for each setting. Estimators of their variance are also developed. The two-step estimator for survival data and its variance estimator are shown by simulation to be minimally biased and the estimator is shown to be efficient relative to the Cox partial likelihood estimator in small samples.

Biometry↗
PubMed1984

A randomised controlled trial of hospice care.

Terminally ill cancer patients at a Veterans Administration hospital were randomly assigned to receive hospice or conventional care. The hospice care was provided both in a special inpatient unit and at home. 137 hospice patients and 110 control patients and their familial care givers (FCGs) were followed until the patient's death. No significant differences were noted between the patient groups in measures of pain, symptoms, activities of daily living, or affect. Hospice patients expressed more satisfaction with the care they received; and hospice patients' FCGs showed somewhat more satisfaction and less anxiety than did those of controls. Hospice care was not associated with a reduced use of hospital inpatient days or therapeutic procedures and was at least as expensive as conventional care.

Activities of Daily Living↗
PubMed1984

Surgical anatomy of the extraparotid distribution of the facial nerve.

The peripheral, extraparotid distribution of the clinically important branches of the facial nerve is described, with common variations, based on the anatomical dissection of 35 cadaver half heads. Methods are suggested for avoiding, isolating, and protecting the facial nerve branches during surgical procedures.

Cadaver↗
PubMed1984

A comparison of Class II treatment changes noted with the light wire, edgewise, and Fränkel appliances.

The purpose of this study was to determine if selected cephalometric changes noted in groups of growing patients with Class II, Division 1 malocclusions treated with the Fränkel function regulator (FR-2), the edgewise technique, and the light-wire (Begg) mechanism were different and characteristic of a specific technique. To this end, the changes in the SNA, SNB, N-S-Gn, and the SN-GoGn angles, face height (N-M), the anterior movement of pogonion, and the annualized mandibular growth increment (AR-Gn) in a group of patients treated with the FR-2 were compared to the changes noted in similar groups of patients treated by the edgewise technique and the light-wire mechanism. The methods used to compare the groups were an analysis of variance and a discriminant analysis. A reduction in the SNA angle was observed in all groups. It was -0.37 degrees with light wire treatment, -0.60 degrees with Fränkel appliance use, and -1.47 degrees with edgewise therapy. The SNB angle increased in all three groups, ranging from 0.29 degrees in the edgewise group to 0.56 degrees in the Fränkel group. In the light-wire group it was 0.34 degrees. The N-S-Gn angle in the Fränkel group remained essentially the same (0.06 degrees), while in the light-wire and edgewise groups it increased 0.81 degrees and 0.82 degrees. The SN-GoGn angle opened slightly in all groups, ranging from a low of 0.46 degrees with Fränkel therapy to 0.58 degrees with edgewise treatment to 1.25 degrees with the use of the light-wire appliance.(ABSTRACT TRUNCATED AT 250 WORDS)

Activator Appliances↗
PubMed1984

Job activity and colon cancer risk.

The authors studied 2,950 population-based colon cancer cases in males in Los Angeles County, California, that were diagnosed between 1972 and 1981. To determine if colon cancer risk is reduced by physical activity on the job in males aged 20-64 years, the authors first rated each occupation by judging the activity level as high, moderate, or sedentary. Men with sedentary jobs had a colon cancer risk at least 1.6 times that of men whose jobs required a high level of activity. Risk increased in a stepwise manner as activity level decreased. This gradient was consistently seen within each socioeconomic stratum, among whites, blacks, immigrant and native Hispanics, and for each subsection of the colon from the hepatic flexure to the sigmoid. The protective effect of physical activity was very strong in the descending colon and diminished in a gradient both proximally and distally. There was no such relationship between physical activity and risk for rectal cancer. Physical activity may play a major, previously unrecognized role in colon cancer etiology. Such a role is consistent with the known pattern of colon cancer occurrence and with our understanding of colon physiology and colon cancer pathogenesis. In addition to the implications for prevention, understanding the effects of physical activity on colon cancer risk may allow future studies to evaluate more accurately the role played by diet.

Adult↗
PubMed1984

Respiratory and eye irritation from boron oxide and boric acid dusts.

Boron oxide has been shown in animals to irritate the respiratory mucosa and conjunctiva. The present study was undertaken to determine whether exposures to boron oxide and its hydration product, boric acid, cause respiratory and eye irritation in humans. One hundred thirteen workers exposed to these materials and 214 unexposed workers were interviewed regarding symptoms. Statistically significant associations were found between eye irritation, dryness of the mouth, nose, or throat, sore throat, and productive cough and mean exposures of 4.1 mg/m3 (which probably did not exceed 8.5 mg/m3).

Adult↗
PubMed1984

Pulmonary effects of exposures in silicon carbide manufacturing.

Chest x rays, smoking histories, and pulmonary function tests were obtained for 171 men employed in the manufacturing of silicon carbide. A lifetime exposure to respirable particulates (organic and inorganic fractions) and sulphur dioxide was estimated for each worker. Chest x ray abnormalities were related to respirable particulates (round opacities) and to age and smoking (linear opacities). Pulmonary function was affected by respirable particulates (FVC) and by sulphur dioxide and smoking (FEV1). Pleural thickening was related to age. No exposures exceeded the relevant standards; we therefore conclude that the current standards do not provide protection against injurious pulmonary effects, at least in this industry.

Adult↗
PubMed1984

Malignant mesothelioma: incidence, asbestos exposure, and reclassification of histopathology.

The Los Angeles County Cancer Surveillance Program abstracts records on almost all cases of cancer occurring in the county. In a study of those cases of pleural and peritoneal malignant mesothelioma (MM) that occurred from 1972 to 1979 occupational histories were obtained during interviews, and histopathology of the tumours was reviewed and classified by a member of a mesothelioma reference panel who was unaware of the exposure histories. About half the cases reviewed had likely exposure to asbestos at work. The greatest proportion of cases designated as MM by the pathologist occurred among individuals likely to have had the heaviest exposure of asbestos (42%). No upward trend of incidence over time was apparent among cases designated as MM. The age adjusted incidence rates for designated MM were lower than in other studies. The well recognised interobserver variability in diagnosing MM apparently produces raised estimates of incidence and an overestimate of trends of incidence. The interobserver variability may result from different awareness of MM occurrence, a lack of precise histopathological criteria for the diagnosis, or the influence of a history of exposure to asbestos on the interpretation. A history of exposure to asbestos may bias interpretation of histopathology and should not be used to make the histological diagnosis.

Asbestos↗
PubMed1984

Evaluation of the parotid gland. Comparison of sialography, non-contrast computed tomography, and CT sialography.

Sialography, non-contrast computed tomography (NCCT), and CT sialography (CTS) were compared in 40 patients with parotid disease. While NCCT and CTS proved to be superior to sialography in most cases, with NCCT being as good as CTS for demonstration of parotid masses, sialography was preferred over both NCCT and CTS for evaluation of inflammatory disease. The role of percutaneous needle aspiration is discussed, and protocols for evaluation of both parotid masses and inflammatory disease are presented.

Adenolymphoma↗