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Biomedical subjects

L Bernstein

Publications and source records attributed to L Bernstein.

At least 181 records · Page 10Linked to original sources
PubMed1988

Vasectomy, cigarette smoking, and age at first sexual intercourse as risk factors for prostate cancer in middle-aged men.

A population-based case-control study was conducted in men aged 60 or less to assess the risk of prostate cancer associated with vasectomy and other factors. Data were obtained from 216 case-control pairs by telephone interviews; this number represented 55% of all eligible cases. The matched pairs relative risk (RR) for vasectomy in ever married men was 1.4 with a 95% confidence interval (CI) of 0.9-2.3. There was a positive association between the number of years since vasectomy and prostate cancer risk (1-sided P = 0.01). Early age at first sexual intercourse was associated with increased prostate cancer risk (age less than 17 vs. 21+, RR = 2.3, 95% CI = 1.3, 4.0) but there were no consistent associations with number of sexual partners or frequency of sexual intercourse. Cigarette smoking was also associated with increased risk of prostate cancer (RR = 1.9, 95% CI = 1.2, 3.0) and there was a positive dose-response relationship with years of smoking (1-sided P = 0.001). We discuss the possible implication of the low response rate on each of these findings. To determine whether the association with vasectomy might have a hormonal basis, we compared levels of testosterone (T) and testosterone binding globulin-binding capacity (TeBG-bc) in 33 of the vasectomized control men with levels in 33 non-vasectomized controls of the same age, weight and height. T levels were higher in vasectomized than in non-vasectomized controls (1-sided P = 0.06). The ratio of T to TeBG-bc (an index of bioavailable T) was 13.5% higher in vasectomized men (1-sided P = 0.03).

Adenocarcinoma↗
PubMed1988

Adenocarcinoma of the stomach and exposure to occupational dust.

The authors studied 1,342 cases of adenocarcinoma of the stomach identified by a population-based cancer registry in Los Angeles County, California. The cases were males aged 20-64 years first diagnosed between 1972 and 1982. To determine whether exposure to occupational dust increased the risk of developing stomach cancer, occupational titles were rated for the likelihood of exposure to various kinds of dust. Men who worked in dusty jobs had a risk for developing stomach cancer 1.3 times that of unexposed men (95% confidence interval = 1.2-1.4). The association of exposure to dust with stomach cancer was stronger at higher levels of exposure. The risk was not uniform throughout the stomach: the highest risk (1.8 times that of unexposed men) was found for the antrum/pylorus. At that site, exposure to mineral dust carried the greatest risk for cancer (3.7 times the risk for unexposed men). The highest risks from dust exposure were observed in blacks. Risk was related to race, socioeconomic status, and immigrant status, but these factors did not entirely explain the association with dust exposure. The observed relation between dust exposure and stomach cancer is consistent with results of previous mortality and case-control studies of cancer in men who worked in dusty occupations. Ingested dust may be one factor in the etiology of adenocarcinoma of the stomach.

Adenocarcinoma↗
PubMed1988

Avoidable nondietary risk factors for cancer.

Smoking cessation has the greatest potential for reducing cancer mortality. Moderate physical activity may prevent colon cancer by modifying bowel peristalsis patterns and may prevent breast cancer by modifying ovulatory frequency. Radiation therapy and the use of certain drugs may increase the risk of some cancers. Liver cancer may be the most preventable major cancer.

Adult↗
PubMed1988

Acquired circulating anticoagulants in children with acquired immunodeficiency syndrome.

The mechanism underlying the prolonged activated partial thromboplastin time (APTT) seen in some pediatric patients with acquired immunodeficiency syndrome (AIDS) and opportunistic infections was studied. A circulating inhibitor of coagulation was demonstrated in three patients. The inhibitor appears to be an immunoglobulin that interferes with some of the phospolipid-dependent coagulation reactions of the intrinsic pathway. This "AIDS anticoagulant" does not predispose the patient to clinical bleeding despite its ability to cause a marked prolongation of the APTT. As such, careful laboratory diagnosis of the cause of abnormal coagulation test results is necessary for children with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Respiratory effects of cotton dust exposure in the cotton garnetting industry.

We measured exposures to total dust, vertically elutriated dust, and endotoxin and studied acute pulmonary responses among 128 workers in the cotton garnetting and mattress assembly industries. Previous studies in this segment of industry have not characterized endotoxin exposures or related them to pulmonary responses. The median 8-hour time-weighted average total dust was 0.72 mg/m3, the median vertically elutriated dust was 0.22 mg/m3, and the median endotoxin concentration was 5.2 ng/m3. Ten percent of the subjects reported chest tightness or dyspnea on Mondays. Thirteen percent of the subjects reported symptoms of chronic bronchitis. Although there was no relationship between changes in pulmonary function across the workshift and either total dust, vertically elutriated dust, or endotoxin exposure, 13% of the subjects had greater than 5% decrements in FEV1 over the workshift.

Adult↗
PubMed1987

Examination of the correlation of serum metoclopramide levels with antiemetic efficacy in patients receiving cisplatin.

The existence of a threshold serum metoclopramide level above which total protection from cisplatin-induced vomiting is more likely to occur has been proposed. We monitored serum metoclopramide levels prior to the third metoclopramide dose in the first cisplatin treatment cycle in patients receiving metoclopramide 2 mg/kg x 4 as part of a randomized double-blind cross-over study comparing single-agent metoclopramide with combination metoclopramide and dexamethasone. Serum samples from 35 patients (17 receiving single-agent metoclopramide and 18 receiving the combination) were analyzed using reverse-phase high-pressure liquid chromatography (HPLC). A wide variation in metoclopramide levels was observed (range 273-3380 ng/ml). Serum levels obtained from the same patient on multiple treatment cycles were well correlated, and the addition of dexamethasone did not alter serum metoclopramide levels. No threshold level could be identified for the two groups (single-agent or combination antiemetic therapy) considered individually or considered together. However, significantly more vomiting episodes and a lower incidence of total protection were noted in patients with metoclopramide levels above 1469 ng/ml receiving metoclopramide alone. This effect was nullified in the combination antiemetic group. Our data do not support a directly proportional relationship between serum metoclopramide level and antiemetic protection. However, a non-linear relationship with a possible agonist/antagonist effect is suggested.

Adult↗
PubMed1987

Hyperemesis gravidarum in relation to estradiol levels, pregnancy outcome, and other maternal factors: a seroepidemiologic study.

Two studies were conducted to assess factors associated with increased risk of hyperemesis gravidarum during pregnancy with data and serum samples collected from participants in the Collaborative Perinatal Study. In the case-control study, 419 pregnant women with hyperemesis gravidarum were matched on medical center, date of study registration, and race with 836 pregnant women who did not vomit during the index pregnancy. Younger age, nulliparity, and high body weight were significantly associated with increased risk of hyperemesis. Women with hyperemesis had significantly reduced risk of fetal loss; however, their infants had higher risk of central nervous system malformations. In the second study, first-trimester pregnancy hormones were measured in the serum of 35 women with hyperemesis and 35 control women who were individually matched to cases on age, parity, and medical center. After adjusting for length of gestation, mean levels of total estradiol were 26% higher and mean levels of sex hormone binding-globulin binding capacity were 37% higher in patients with hyperemesis gravidarum than in control subjects. These differences were statistically significant. Although human chorionic gonadotropin concentrations were higher in control pregnancies, the differences were not statistically significant. The average amount of estradiol that was nonprotein bound (adjusted for length of gestation) was also higher in patients than in control subjects. These results are consistent with the hypothesis that elevated estrogen levels are responsible for excessive vomiting in pregnancy.

Adult↗
PubMed1987

Chylomicrons and chylomicron remnants in coronary artery disease: a case-control study.

Epidemiologic studies of coronary artery disease have largely overlooked the role of triglyceride-rich lipoproteins circulating in the post-prandial state. We have conducted a case-control study in males which examined fasting plasma lipoproteins and lipoproteins circulating 4 h after ingestion of a test meal containing fat and cholesterol. The cases were 82 subjects with coronary artery disease confirmed by angiography, while there were two control groups: one group of 38 'hospital controls' free of significant coronary disease by angiography, and a second group of 61 'workforce controls' free of coronary disease on historical grounds. Mean plasma and LDL cholesterol levels were significantly higher and HDL cholesterol levels were significantly lower in cases than in controls. The apo-B48/apo-B100 ratio in lipoproteins Sf greater than 60 obtained 4 h post-prandially, a relative measure of chylomicron and remnant presence, was significantly higher in cases than in controls. After pooling of all data, the prevalence of coronary artery disease was found to increase progressively with the concentration of plasma cholesterol and triglycerides, total cholesterol/HDL cholesterol ratio and the apo-B48/apo-B100 ratio in Sf greater than 60, the relative risk being highest for total cholesterol/HDL cholesterol ratio. After controlling for the confounding effects of age and other lipid factors via multiple logistic regression, apo-B48/apo-B100 ratio was still a significant predictor of coronary artery disease presence (z = 1.97, P less than 0.05) in a 'dose-response' fashion. The risk of coronary artery disease in the top quartile of apo-B48/apo-B100 distribution was 2.2-fold greater than that for the bottom quartile, after adjustment for the effects of other risk factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Stress processes and the misuse of drugs in older adults.

There is increasing concern about the misuse of drugs among the elderly. We assessed misuse, including drug usage, drug interactions across pharmacologic classes, and multiple drugs in the same pharmacologic class, in a community sample of 65 to 74-year-olds, and evaluated its relation to stress and coping processes and psychological and somatic health. Assessments were made repeatedly over a 6-month period. Results indicated that misuse was multidimensional and widespread. Misusers did not differ from nonmisusers on antecedent psychosocial variables, nor did they report more hassles or cope differently than nonmisusers. However, misusers and nonmisusers differed on their subjective experience of stressful encounters; misusers experienced their hassles as more intense, and they experienced more threat emotions and more dissatisfaction with their coping than did nonmisusers. Misuse was also associated with long-term psychological satisfaction, psychological symptoms, and somatic health.

Adaptation, Psychological↗
PubMed1987

The effects of moderate physical activity on menstrual cycle patterns in adolescence: implications for breast cancer prevention.

Girls who engage in strenuous physical activity are often amenorrheic and have recently been reported to be at a reduced risk of breast cancer. To determine whether moderate amounts of exercise affect menstrual cycle patterns and ovulatory frequency in young postmenarcheal girls, the menstrual cycles and physical activity patterns of 168 high school girls were monitored for a 6 month period. Anovulatory cycles were associated with later age at menarche, fewer elapsed years since menarche and greater levels of energy expended per week in physical activity. After adjusting for age at menarche and years since menarche, there was a significant dose-related trend in the risk of anovular menstrual cycles associated with increasing levels of physical activity (1-sided P = 0.03). Major determinants of average cycle length were weekly average energy expenditure (less than or equal to 750 kcal wk-1 associated with cycles that were on average 2.4 days longer), age at menarche (an increase of 0.7 days per year of age) and race (Asians having cycles about 1.9 days longer than Caucasians). Because a major determinant of breast cancer risk may be the cumulative number of ovulatory cycles, these data suggest that regular participation in moderate physical activity, by reducing the frequency of ovulatory cycles in adolescence, may provide an opportunity for the primary prevention of breast cancer.

Adolescent↗
PubMed1987

Thyroid cancer among young women related to prior thyroid disease and pregnancy history.

We conducted an epidemiologic case-control study of thyroid cancer in women aged 40 and under to test the hypothesis that endogenous hormones may relate to the development of this disease, since the only known cause of thyroid cancer, ionizing radiation, does not account for the striking female over male excess. When compared to neighbour controls women with thyroid cancer more often had a history of benign hyperplastic thyroid disease (Relative Risk (RR) = 14.5; P less than 0.01) and more often had ever been pregnant (RR = 2.1; P = 0.04). Both these findings were consistent with findings of previous studies. After eliminating women with a history of hyperplastic thyroid disease from the analysis we found a strong association with miscarriage as the outcome of the first pregnancy (RR = 11.5; P less than 0.01), and we suspect that this factor may be another indicator of thyroid abnormality. An independent and increasing risk was observed with an increase in the total number of pregnancies after excluding women with prior thyroid disease and those whose first pregnancy ended in a miscarriage. The RR for 4 or more pregnancies was 6.3 (P = 0.03). Prior exposure to radiation therapy was not an important factor in our study of young women; this suggests that the emphasis in future studies of thyroid cancer must shift to study other types of risk factors.

Abortion, Spontaneous↗
PubMed1987

Correlation of meningioma hormone receptor status with hormone sensitivity in a tumor stem-cell assay.

Several investigators have detected progesterone receptors in a high percentage of meningioma specimens and have noted progesterone receptors to be more common than estrogen receptors in these specimens. However, a functional significance of such hormone receptor positivity in control of meningioma growth has not been described. This paper describes a paired test of the estrogen and progesterone receptor assay as the biochemical assay and of the human tumor stem-cell clonogenic assay (HTSCCA) as the functional assay in 17 meningioma specimens. Only one (6%) of the 17 specimens was estrogen receptor-positive, while 11 (69%) of 16 specimens were progesterone receptor-positive. The HTSCCA revealed that only two (15%) of 13 specimens were sensitive to estradiol while five (31%) of 16 specimens were sensitive to progesterone. Comparison of progesterone results for the 15 specimens on which both hormone receptor assay and HTSCCA were performed revealed correlation in a majority of cases; four specimens were positive for both assays and five specimens were negative for both assays. No specimen that was negative for progesterone receptors was sensitive to progesterone by HTSCCA. These results suggest that the hormone receptor and sensitivity pattern of meningiomas may differ from that of breast cancer, and that progesterone addition or ablation may be a reasonable therapeutic approach for meningiomas.

Female↗
PubMed1987

Abnormalities of pulmonary function and pleural disease among titanium metal production workers.

The authors conducted a cross-sectional survey of respiratory disease among 209 titanium metal production workers. Work in areas where there was exposure to titanium tetrachloride and titanium dioxide particulates was associated with reductions in ventilatory capacity. Pleural disease (plaques and diffuse thickening) was present in the chest radiographs of 17% of the subjects and was associated with the duration of work in titanium manufacturing. It was also associated with past asbestos exposure. After control for asbestos exposure, it remained associated with titanium manufacturing. The findings are consistent with the hypothesis that titanium tetrachloride and titanium dioxide particulates may be associated with a reduction in ventilatory capacity and that the overall process of titanium manufacturing may be associated with unexpected pleural disease.

Adult↗
PubMed1987

Reproducibility of results in "near-replicate" carcinogenesis bioassays.

Reproducibility of results was examined in 70 "near-replicate" comparisons consisting of 2 or more long-term carcinogenesis bioassays of the same chemical administered by the same route and using the same sex and strain of rodent. Overall, there was good reproducibility of positivity, target site, and carcinogenic potency in hamsters, mice, and rats. The published authors' opinions about whether the test was positive disagreed in only 9 of the 70 comparisons. Among the 35 comparisons in which all tests of the chemical were positive, 33 of the near-replicates had at least 1 identical target site. The carcinogenic potency values estimated from near-replicate tests in these 35 comparisons were within a factor of 2 of each other in 40% of the comparisons, within a factor of 5 in 80%, and within a factor of 10 in 90%. For the few cases in which the carcinogenic response was not reproduced, analyses suggest two explanations: In mice the discrepant cases tended to have shorter experiment times than average; in both rats and mice the discrepant results tended to be tests of weakly active compounds.

Animals↗
PubMed1987

Childhood leukemia and parents' occupational and home exposures.

A case-control study of children of ages 10 years and under in Los Angeles County was conducted to investigate the causes of leukemia. The mothers and fathers of acute leukemia cases and their individually matched controls were interviewed regarding specific occupational and home exposures as well as other potential risk factors associated with leukemia. Analysis of the information from the 123 matched pairs showed an increased risk of leukemia for children whose fathers had occupational exposure after the birth of the child to chlorinated solvents [odds ratio (OR) = 3.5, P = .01], spray paint (OR = 2.0, P = .02), dyes or pigments (OR = 4.5, P = .03), methyl ethyl ketone (CAS: 78-93-3; OR = 3.0, P = .05), and cutting oil (OR = 1.7, P = .05) or whose fathers were exposed during the mother's pregnancy with the child to spray paint (OR = 2.2, P = .03). For all of these, the risk associated with frequent use was greater than for infrequent use. There was an increased risk of leukemia for the child if the father worked in industries manufacturing transportation equipment (mostly aircraft) (OR = 2.5, P = .03) or machinery (OR = 3.0, P = .02). An increased risk was found for children whose parents used pesticides in the home (OR = 3.8, P = .004) or garden (OR = 6.5, P = .007) or who burned incense in the home (OR = 2.7, P = .007). The risk was greater for frequent use. Risk of leukemia was related to mothers' employment in personal service industries (OR = 2.7, P = .04) but not to specified occupational exposures. Risk related to fathers' exposure to chlorinated solvents, employment in the transportation equipment-manufacturing industry, and parents' exposure to household or garden pesticides and incense remains statistically significant after adjusting for the other significant findings.

Acute Disease↗
PubMed1987

Smoking as a risk factor in noise-induced hearing loss.

We studied the relationship between cigarette smoking and hearing loss among 2,348 noise-exposed white male participants in a hearing conservation program at an aerospace company. Comparisons of risk factors were based on two definitions of hearing loss. In the first, cases were defined as those subjects in the top third of the hearing loss distribution (at 3, 4, and 6 kHz) for their age category, and controls were those subjects in the lowest third of the distribution. The crude relative risks for smokers were significantly elevated (ever smoker: odds ratio = 1.27, p = .02; present smoker: odd ratio = 1.39, P = .002) compared with never smokers. Simultaneous evaluation of several risk factors using multiple logistic regression methods indicated that the effects of smoking, having a noisy hobby, and years worked at the plant were independent factors for hearing loss. Statistically significant trends in risk were observed for the number of pack-years of smoking (P = .007) and current packs per day consumption in present smokers (P = .009). In the second definition, hearing loss cases were defined according to National Institute for Occupational Safety and Health criteria for beginning impairment. By using multiple logistic regression, present smoking was a statistically significant independent predictor of impairment. These results suggest that smokers are at increased risk of noise-induced hearing loss.

Adolescent↗
PubMed1986

Solitary colonic ulcer in a spinal cord injured patient.

Bleeding from the lower gastrointestinal tract is rarely reported in spinal cord injured patients. A case is reported of such bleeding in a quadriplegic man with a solitary colonic ulcer diagnosed by flexible sigmoidoscopy and biopsy. The diagnosis of solitary colonic ulcers is difficult to make in spinal cord injured persons because presenting features may be masked by the neurologic deficits caused by the injury or may be falsely attributed to problems associated with the injury or to iatrogenic trauma. Solitary colonic ulcer should be included in the differential diagnosis of gastrointestinal bleeding in persons with spinal cord injury. Flexible sigmoidoscopy or colonoscopy is recommended for visualization and biopsy of the bleeding lesion.

Adult↗