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Biomedical subjects

L Bernstein

Publications and source records attributed to L Bernstein.

At least 163 records · Page 9Linked to original sources
PubMed1989

AIDS-related secular trends in cancer in Los Angeles County men: a comparison by marital status.

Data from the population-based cancer registry for Los Angeles County, an area with high risk of AIDS, were used to evaluate secular trends of Kaposi's sarcoma (KS), non-Hodgkin's lymphoma, and other possibly AIDS-related cancers in men aged 18 to 54. Marital status was used as a surrogate for homosexual behavior to compare the proportional incidence rates for the pre-AIDS era, 1972 to 1979, to those for 1980 to 1982 and 1983 to 1985. Both absolute incidence and proportional incidence of KS continue to increase sharply, although in absolute numbers, KS is making a smaller contribution to the total number of AIDS cases as the Los Angeles County epidemic progresses. For never-married men the proportional incidence rate of KS in 1983 to 1985 was nearly 100-fold greater than that of 1972 to 1979 and 7-fold greater than that of 1980 to 1982. High-grade lymphomas show statistically significant secular increases in both never-married and ever-married men, but only the rates of Burkitt's lymphomas have increased to a greater extent in never-married men. A small but significant increase of central nervous system lymphomas is seen in both marital status groups. There is no evidence of any AIDS-related increases in Hodgkin's disease, leukemia, testicular cancer, anal cancer, liver cancer, oral cancer, multiple myeloma, or malignant melanoma. As of 1985, cancer, as a manifestation of AIDS, is still apparently limited to KS and high-grade lymphomas (particularly Burkitt's) in Los Angeles County.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Fatal occupational injuries in California, 1972-1983.

Prior reports have indicated that the crude incidence of fatal occupational accidents in California has substantially declined since at least 1972. We tested the hypothesis that this observation was an artifact of demographic shifts in the workforce towards lower-risk age groups and industries. Review of worker's compensation data from 1972 to 1983 identified 2,483 fatal injuries among males. Crude rates declined by an average of 7.0% annually (p less than .005). Age and industry adjustment reduced this decline to 6.7% annually, but the trend was still significant (p less than .005). Thus, the decline in fatal injury rates is not artifactual and will require further study to explain. In a separate analysis, age-specific death rates were found to follow a bimodal pattern in most industries with the highest rates observed at the extremes of age. These results conflict with those of several previous studies. However, these studies did not adjust for the prevalence of part-time work schedules among younger employees.

Accidents, Occupational↗
PubMed1989

Case-control study of lung cancer in Los Angeles county welders.

A case-control study of lung cancer in white male welders was undertaken to investigate possible environmental and occupational causes of a 50% excess of lung cancer observed in this occupational group. The subjects were identified from a population-based cancer registry in Los Angeles County. A standardized questionnaire was administered to either subjects or proxy informants of 90 lung cancer cases and 116 non-lung-cancer controls. Significantly increased risks of lung cancer were associated with tobacco smoking (odds ratio 7.6, p less than .005) and shipyard welding with at least a 10-year latency since first exposure (odds ratio 1.7, p less than .05). Although there were elevated risks associated with some specific welding processes, none were statistically significant. Control subjects were more likely to have had exposure to confined-space welding (odds ratio 0.6, 95% CI = 0.3-1.2), and this association was greatest where there had been at least a 20-year latency since first exposure (0.5, 95% CI = 0.3-1.0). We conclude that the excess of lung cancer in this welding population is contributed to by a higher frequency of smoking and probable exposure to asbestos in shipyards. Other factors may be important, but probably because of limited power and reliance on proxy information, this study failed to detect other statistically significant risks.

Adult↗
PubMed1989

Cigarette smoking in pregnancy results in marked decrease in maternal hCG and oestradiol levels.

We have examined serum levels of oestradiol (E2), sex-hormone binding globulin (SHBG) and human chorionic gonadotrophin (hCG) during early pregnancy in relation to smoking status at the time of sampling in a series of 147 women. Smoking was associated with significantly depressed serum levels of E2, SHBG and hCG: in smokers, E2 levels were on average 17.6% lower (P = 0.037), SHBG levels were 12.4% lower (P = 0.15), and hCG levels were 21.5% lower (P = 0.044). There appeared to be a steady decline in these values with increasing cigarette consumption. These lower hormone levels in smokers may explain certain adverse effects of smoking in pregnancy.

Adult↗
PubMed1989

Summary of carcinogenic potency and positivity for 492 rodent carcinogens in the carcinogenic potency database.

A tabulation of carcinogenic potency (TD50) by species for 492 chemicals that induce tumors in rats or mice is presented. With the use of the Carcinogenic Potency Database, experimental results are summarized by indicating in which sex-species groups the chemical was tested and the respective evaluations of carcinogenicity. A comparison of three summary measures of TD50 for chemicals with more than one positive experiment per species shows that the most potent TD50 value is similar to measures that average values or functions of values. This tabulation can be used to investigate associations between rodent potency and other factors such as mutagenicity, teratogenicity, chemical structure, and human exposure.

Animals↗
PubMed1989

Interspecies extrapolation in carcinogenesis: prediction between rats and mice.

Interspecies extrapolation in carcinogenesis is studied by evaluating prediction from rats to mice and from mice to rats. The Carcinogenic Potency Database, which includes 3500 cancer tests conducted in rats or mice on 955 compounds, is used for the analysis. About half of the chemicals tested for carcinogenicity are positive in at least one test, and this proportion is similar when rats and mice are considered separately. For 392 chemicals tested in both species, 76% of the rat carcinogens are positive in the mouse, and 70% of mouse carcinogens are positive in the rat. When compounds composed solely of chlorine, carbon, hydrogen, and, optionally, oxygen are excluded from the analysis, 75% of mouse carcinogens are positive in the rat. Overall concordance (the percentage positive in both species plus the percentage negative in both) is 76%. Three factors that affect prediction between rats and mice are discussed: chemical class, mutagenicity in the Salmonella assay, and the dose level at which a chemical is toxic. Prediction is more accurate for mutagens than non-mutagens and for substances that are toxic at low (versus only at high) doses. Species differences are not the result of failure in the bioassay to attain the maximum tolerated dose in the negative species or of more frequent testing in the positive species. An analysis of the predictive value of positivity for the 10 most common target sites indicates that most sites are good predictors of carcinogenicity at some site in the other species; the poorest predictors among these common sites are the rat urinary bladder and the mouse liver.

Animals↗
PubMed1989

Focus groups improve billing practices, patient relations.

The billing process plays a key role in maintaining good patient relations. Recognizing this, one California hospital conducted focus groups to discover how recently discharged patients viewed its billing process. The former patients gave patient accounts staff high marks, but found the bills themselves difficult to understand. Another source of irritation was receiving separate bills from outside specialists for treatment provided in-house. The hospital is using the participants' suggestions to enhance its billing process.

Accounting↗
PubMed1989

[Determination of N-acetylneuraminic acid for the differential diagnosis of cystic ovarian tumors].

The concentrations of N-acetylneuraminic acid (NANA) were determined in the fluid of cystic ovarian tumors and in the blood serum from a total of 95 patients. The estimation of NANA was based on the method of Svennerholm. It was found that the mean content of NANA in the cystic fluid is more than 3.0 mmol/l in serous and more than 5.5 mmol/l in mucinous malignant ovarian tumors. The mean value of NANA in the serum of patients is mostly more than 3.5 mmol/l if there is an ovarian cancer. The estimation of NANA is useful for the preoperative diagnosis of cystic ovarian tumors.

Adolescent↗
PubMed1988

Mechanisms of innate resistance to thymidylate synthase inhibition after 5-fluorouracil.

Fifty-four patients with metastatic adenocarcinoma received i.v. bolus 5-fluorouracil, 500 mg/m2, prior to surgical biopsy of tumor at 20-400 min, for analysis of biochemical parameters of resistance to thymidylate synthase (TS) inhibition. The majority of patients, 37, had colon or rectal adenocarcinoma, five had breast cancer, five had gastric primary disease, four had pancreatic adenocarcinoma, and three had hepatocellular adenocarcinoma. Fluorodeoxyuridylate (FdUMP) was assayed by isotope dilution of [3H]FdUMP binding to bacterial TS; free and total TS was determined by [3H]FdUMP binding; and deoxyuridylate (dUMP) was assayed by conversion to [14C]thymidylate. Free levels of TS were lower in breast cancers, 0.08 +/- 0.06 pmol/g, than in other histologies (overall average, 1.41 +/- 2.25), associated with significantly greater percentages of TS inhibition (88.6% versus 62.0% overall). Colorectal tumors showed significantly greater FdUMP levels than other gastrointestinal malignancies, associated with somewhat lower free TS values. Plots of FdUMP levels, or (FdUMP/dUMP) x 100 values versus percentages of TS inhibition suggested minima of 75 pmol/g and 0.10, respectively, for achieving maximal enzyme inhibition. Analyses of normal tissues showed: poor TS inhibition in liver and normal colonic mucosa, related to low FdUMP levels; and very high dUMP levels in bone marrow leukocytes suggestive of reactive increases in dUMP as an important mechanism of recovery in this tissue. Among the 30 of the 37 colorectal tumors that showed suboptimal (less than 85%) inhibition of TS, 16 (53%) showed FdUMP levels less than 75 pmol/g, 8 (27%) showed relatively high dUMP levels (over 35 nmol/g), and 16 (53%) showed poor efficiency of inhibition of TS, with the major overlap between these mechanisms of resistance being high dUMP and poor binding in 6 (20%). These data provide a strong rationale for administration of leucovorin to the majority of patients receiving 5-fluorouracil, since increased intratumoral reduced folates potentially can overcome multiple mechanisms of resistance including low FdUMP, high dUMP, and high total TS levels, in addition to that caused by isolated folate deficiency.

Adenocarcinoma↗
PubMed1988

Smoking and drinking in relation to oral and pharyngeal cancer.

A case-control study of oral and pharyngeal cancer conducted in four areas of the United States provided information on the tobacco and alcohol use of 1114 patients and 1268 population-based controls. Because of the large study size, it could be shown that the risks of these cancers among nondrinkers increased with amount smoked, and conversely that the risks among nonsmokers increased with the level of alcohol intake. Among consumers of both products, risks of oropharyngeal cancer tended to combine more in a multiplicative than additive fashion and were increased more than 35-fold among those who consumed two or more packs of cigarettes and more than four alcoholic drinks/day. Cigarette, cigar, and pipe smoking were separately implicated, although it was shown for the first time that risk was not as high among male lifelong filter cigarette smokers. Cessation of smoking was associated with a sharply reduced risk of this cancer, with no excess detected among those having quit for 10 or more years, suggesting that smoking affects primarily a late stage in the process of oropharyngeal carcinogenesis. The risks varied by type of alcoholic beverage, being higher among those consuming hard liquor or beer than wine. The relative risk patterns were generally similar among whites and blacks, and among males and females, and showed little difference when oral and pharyngeal cancers were analyzed separately. From calculations of attributable risk, we estimate that tobacco smoking and alcohol drinking combine to account for approximately three-fourths of all oral and pharyngeal cancers in the United States.

Black or African American↗
PubMed1988

Mortality of aircraft manufacturing workers in southern California.

A retrospective cohort mortality study was conducted among men and women employed for four or more years, between 1958 and 1982, at an aircraft manufacturing company in San Diego County. Specific causes of death under investigation included cancer of the brain and nervous system, malignant melanoma, and cancer of the testicle, which previous reports have suggested to be associated with work in aircraft manufacturing. Follow-up of the cohort of 14,067 subjects for a mean duration of 15.8 yr from the date of first employment resulted in successful tracing of 95% of the cohort and found 1,804 deaths through 1982. Standardized mortality ratios (SMRs) were calculated based on U. S. national mortality rates and separately based on San Diego County mortality rates. Mortality due to all causes was significantly low (SMR = 75), as was mortality due to all cancer (SMR = 84). There was no significant excess of cancer of the brain, malignant melanoma, cancer of the testicle, any other cancer site, or any other category of death. Additional analyses of cancer sites for which at least ten deaths were found and for which the SMR was at least 110 showed no increase in risk with increasing duration of work or in any specific calendar period. Although this study found no significant excesses in cause-specific mortality, excess risks cannot be ruled out for those diseases that have latency periods in excess of 20 to 30 yr, or for exposures that might be restricted to a small proportion of the cohort.

Aircraft↗
PubMed1988

A comparative study of perioperative complications with Kock pouch urinary diversion in highly irradiated versus nonirradiated patients.

To define the nature and risk of complications associated with Kock pouch urinary diversion after high dose radiation (more than 4,500 rad), we analyzed the clinical course of 44 irradiated patients and a comparable group of 42 selected retrospectively from the nonirradiated patient cohort. Of the 42 patients in the irradiated group 18 had received 4,500 to 5,700 rad and 24 had received 6,000 to 8,700 rad. With standard statistical methods we found no difference between the irradiated and control groups when compared for age, sex ratio, followup interval, surgical procedure, operative time or estimated blood loss. There were 2 operative mortalities in the irradiated and 1 in the control groups. In the immediate postoperative period there was no difference between the irradiated and control groups when compared for hospital stay, incidence of urine leak or fascial dehiscence. The irradiated group had 8 urine leaks (20 per cent) and 3 patients (7.5 per cent) required surgical repair. The control group had 5 urine leaks and 1 patient (2.3 per cent) required repair. Diarrhea severe enough to require further hospitalization or medication was significantly more frequent in the irradiated group (18 versus 2 per cent) but the postoperative stay was not significantly different (13 versus 11 days). We conclude that Kock pouch urinary diversion may be performed safely in highly irradiated patients.

Combined Modality Therapy↗
PubMed1988

Maternal hormone levels in early gestation of cryptorchid males: a case-control study.

A case-control study was conducted to assess maternal hormonal factors associated with increased risk of bearing a cryptorchid son. Serum samples were collected during the first trimester of pregnancy from participants in the US Collaborative Perinatal Study. Twenty-five mothers of normal offspring (controls) were individually matched on medical center, age, parity, weight and length of gestation at the time of sampling to women bearing sons who had a diagnosis of cryptorchidism at one year of age or older. Compared with controls, mothers of cryptorchid sons (cases) had significantly greater percentages of non-protein bound (P = 0.010) and albumin-bound (P = 0.014) estradiol during the first trimester of the index pregnancy. On average, cases had 16% more bioavailable oestradiol than controls. Levels of human chorionic gonadotropin, testosterone, non-protein bound testosterone and sex-hormone binding globulin did not differ between the two groups. The data presented support the hypothesis that cryptorchidism results from elevated maternal oestrogen levels early in pregnancy.

Adult↗