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Biomedical subjects

L Bernstein

Publications and source records attributed to L Bernstein.

At least 91 records · Page 5Linked to original sources
PubMed1995

Spinal meningiomas in women in Los Angeles County: investigation of an etiological hypothesis.

A series of 3 studies explored the hypothesis that the preponderance of spinal meningiomas among postmenopausal women relates to their higher prevalence of spinal osteoporosis: (a) medical records showed that meningiomas in women, unlike other spinal tumors, usually arise in the mid thoracic spine where osteoporotic vertebral fractures predominate; (b) radiographic evidence of osteoporosis was seen commonly with meningiomas but not with other spinal tumors; and (c) age-adjusted multivariate analysis of data from an interview study of 81 women with spinal meningioma and 155 random digit dial controls showed 6 factors related to risk. Four factors were protective: (a) current use (at diagnosis) of estrogen replacement therapy [odds ratio (OR) = 0.2; 95% confidence interval (CI) = 0.1-0.6]; (b) past use of oral contraceptives (P trend < 0.01); (c) past participation in sports (OR = 0.5; CI = 0.2-0.9); and (d) premenopausal status (OR = 0.2; CI = 0.1-0.7). Risk increased among women who had ever smoked cigarettes (OR = 1.7; CI = 0.9-3.1) or had a history of high dose radiography (> 500 mrad exposure to active marrow/examination; includes upper or lower gastrointestinal series and/or cardiac angiography; OR = 2.9, and CI = 1.6-5.3), although no association was seen with prior radiotherapy. Other results that did not support the hypothesis include findings that cases and controls were similar in mean body weight and in the proportion who had postmenopausal fractures or height loss. In conclusion, these studies lend some support to our hypothesis, but other known meningioma risk factors such as ionizing radiation also appear important.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Physical exercise and reduced risk of breast cancer in young women.

BACKGROUND: Epidemiologic evidence strongly suggests that cumulative exposure to ovarian hormones is a determinant of breast cancer risk. Because physical activity can modify menstrual cycle patterns and alter the production of ovarian hormones, it may reduce breast cancer risk; yet few epidemiologic studies have assessed this relationship. PURPOSE: The major objective of this study was to determine whether young women (aged 40 and younger) who regularly participated in physical exercise activities during their reproductive years had a reduced risk of breast cancer. METHODS: Using a case-control design, we conducted personal interviews of a total of 545 women (aged 40 and younger at diagnosis) who had been newly diagnosed with in situ or invasive breast cancer between July 1, 1983, and January 1, 1989, and a total of 545 control subjects. Case patients and control subjects were individually matched on date of birth (within 36 months), race (white), parity (nulliparous versus parous), and neighborhood of residence. Lifetime histories of participation in physical exercise activities on a regular basis were obtained during the personal interview. RESULTS: After adjustment for potential confounding factors, we found that the average number of hours spent in physical exercise activities per week from menarche to 1 year prior to the case patient's diagnosis was a significant predictor of reduced breast cancer risk (two-sided P for trend < .0001). The odds ratio (OR) of breast cancer among women who, on average, spent 3.8 or more hours per week participating in physical exercise activities was 0.42 (95% confidence limits [CLs] = 0.27, 0.64) relative to inactive women. The effect was stronger among women who had had a full-term pregnancy. Comparing most active (> or = 3.8 hours/wk of exercise) women to inactive women, the ORs were 0.28 (95% CL = 0.16, 0.50) for parous and 0.73 (95% CL = 0.38, 1.41) for nulliparous women. CONCLUSIONS: Most previously identified risk factors for breast cancer are reproductive and menstrual events that cannot be readily altered. The protective effect of exercise on breast cancer risk in the women whom we studied suggests that physical activity offers one modifiable lifestyle characteristic that may substantially reduce a woman's lifetime risk of breast cancer. IMPLICATIONS: Whether the protective effects of exercise on breast cancer risk are due to alterations in ovarian function and whether they extend into women's menopausal years need to be established. Our results suggest that implementation of regular physical exercise programs as a critical component of a healthy lifestyle should be a high priority for adolescent and adult women.

Adolescent↗
PubMed1994

Relationship of leukemia risk to radiation dose following cancer of the uterine corpus.

BACKGROUND: Radiotherapy has been linked infrequently to secondary leukemia despite extensive exposure of the active bone marrow to ionizing radiation. Few studies include substantial numbers of elderly patients. PURPOSE: We evaluated women with cancer of the uterine corpus, the majority of whom were treated at older ages, to gain additional information on cancer risk following partial-body radiotherapy and to examine differences in risk between external-beam therapy and brachytherapy. METHODS: A cohort of 110,000 women with invasive cancer of the uterine corpus who survived at least 1 year following their initial cancer was assembled from nine population-based cancer registries. Cancer diagnoses occurred from 1935 through 1985, and most patients were diagnosed during the 1960s and 1970s. Radiation doses were computed to 17 sections of the active bone marrow for 218 women who developed leukemia and for 775 matched control subjects. RESULTS: Radiotherapy did not increase the risk of chronic lymphocytic leukemia (CLL) (relative risk [RR] = 0.90; 95% confidence interval [CI] = 0.4-1.9). However, for all leukemias except CLL, a significant risk was identified (RR = 1.92; 95% CI = 1.3-2.9). Overall, the pattern of risk in relation to dose was erratic and was most consistent with a constant increased risk across the entire dose range. The risk following continuous exposures from brachytherapy at comparatively low doses and low dose rates (RR = 1.80; 95% CI = 1.1-2.8; mean dose = 1.72 Gy) was similar to that after fractionated exposures at much higher doses and higher dose rates from external-beam treatment (RR = 2.29; 95% CI = 1.4-3.7; mean dose = 9.88 Gy), indicating a large difference in the estimated risk per unit dose. Risk did not vary by age at first exposure; increased risks were apparent for irradiated patients aged 65 years or older (RR = 1.77; 95% CI = 0.9-3.5). CONCLUSION: The leukemia risk associated with partial-body radiotherapy for uterine corpus cancer was small; about 14 excess leukemia cases were due to radiation per 10,000 women followed for 10 years. Women aged 65 years or older had a radiation risk comparable with that found in younger women. The relationship of leukemia risk to radiation dose was found to be complex due to the competing processes of cell killing, transformation, and repair. At very high doses delivered at high rates, destruction of cells likely dominates, and the risk per unit dose is low. In the low dose range, where dose was protracted and delivered at relatively low dose rates, the leukemia risk appears lower than that projected from risk estimates derived from the instantaneous whole-body exposures of atomic bomb survivors.

Aged↗
PubMed1994

Exposure to magnetic fields among electrical workers in relation to leukemia risk in Los Angeles County.

To address the hypotheses that electrical workers are exposed to higher magnetic fields and are at higher risk of leukemia than nonelectrical workers, we performed a registry-based case-control study among men aged 20-64 years with known occupation who were diagnosed with cancer in Los Angeles County between 1972 and 1990. Controls were men with cancers other than those of the central nervous system or leukemia. Magnetic field measurements on workers in each electrical occupation and in a random sample of occupations presumed to be nonelectrical were used to estimate magnetic field exposures for each occupation. Among men in electrical occupations, 121 leukemias were diagnosed. With the exception of electrical engineers, magnetic field exposures were higher among workers in electrical occupations than in nonelectrical occupations. A weakly positive trend in leukemia risk across average occupational magnetic field exposure was observed (odds ratio [OR] per 10 milligauss increase in average magnetic field = 1.2, 95% confidence interval [CI] 1.0-1.5). A slightly stronger association was observed for chronic myloid leukemia, although only 28 cases occurred among electrical workers (OR 10 milligauss increase = 1.6, 95% CI = 1.2-2.0). The results were not materially altered by adjustment for exposure to several agents known or suspected to cause leukemia. Although not conclusive, these results are consistent with findings from studies based on job title alone that electrical workers may be at slightly increased risk of leukemia.

Adult↗
PubMed1994

Effect of prophylactic antibiotics on morbidity associated with IUD insertion: results of a pilot randomized controlled trial. IUD Study Group.

The efficacy of administering an antibiotic prior to IUD insertion to reduce the risk of introducing an upper genital tract infection during the procedure has not yet been established. Two double-blind randomized studies conducted in Africa comparing a 200 mg prophylactic dose of doxycycline with a placebo did not conclusively identify a reduced risk of post-insertion pelvic inflammatory disease (PID). A clinical trial of comparable design is currently under way in the US. This multi-site trial will evaluate whether use of an antibiotic prior to insertion reduces the risk of IUD removal for all medical reasons, including upper genital tract infection, within the first three months after insertion. This paper reports on the pilot phase of this study, which was designed to test the protocols and data collection instruments in advance of the full-scale clinical trial. A total of 447 prospective IUD (TCu-380A) users were randomly assigned to receive either a 200 mg dose of doxycycline or a placebo one hour before IUD insertion. 3.6% (8/219) of participants who received the antibiotic had the device removed for medical reasons (infection, bleeding, cramping, etc.) within three months post-insertion compared to 4.5% (10/223) of participants who received the placebo. This reduction in the removal rate was not statistically significant given the limited size of the pilot study (RR = 0.81; 95% CI 0.28-2.29). Only two subjects, one from each treatment group, met the diagnostic criteria for acute PID. The overall three-month retention rate was 91.8% for the antibiotic group and 89.7% for the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Familial risk in oral and pharyngeal cancer.

We examined the relationship between a family history of cancer and risk of oral and pharyngeal cancer using epidemiological data from a large case-control investigation of these tumours. 487 (45.7%) of the cases and 485 (41.0%) of the controls reported cancer in a parent or a sibling. After controlling for age, race, sex, study location, respondent status and smoking and alcohol use, the OR associated with any cancer in the family was 1.1 [95% confidence interval (CI) 0.9-1.3]. Risks were non-significantly elevated among those with a history of cancers arising from the oral cavity/pharynx (OR = 1.2, 95% CI 0.7-2.3), oesophagus/larynx (OR = 1.6, 95% CI 0.7-3.8) and lung (OR = 1.2, 95% CI 0.8-1.8), with the excess risk primarily among those for whom a male relative, particularly a brother, was affected with these smoking-related cancers. In addition, an elevated risk of oral/pharynx cancer was found among those whose sisters developed other cancers (OR = 1.6, 95% CI 1.1-2.2). Subsite analyses revealed stronger elevated risks of smoking-related cancers in relatives of pharyngeal cancer cases (OR = 1.7, 95% CI 1.1-2.8) than of oral cancer patients. The data indicate that there is at most a weak familial aggregation of oral/pharynx cancers. Furthermore, since the excess familial risk of oral/pharynx cancer was associated with smoking-related cancers among male but not female relatives, it seems likely that environmental factors (notably smoking and drinking) contribute to the familial tendency observed in this study.(ABSTRACT TRUNCATED AT 250 WORDS)

Case-Control Studies↗
PubMed1994

Bartholin's duct abscess and cyst: a case-control study.

Little is known about the epidemiology of Bartholin's duct abscess and cyst. We did an emergency department-based case-control study to examine demographic risk factors for this condition. We found that risk varied by age. After adjustment for pregnancy status, the relative odds (odds ratio [OR]) of occurrence of Bartholin's duct abscess for women 20 to 29 years old, compared to women younger than 20 years, was 2.3. The association was weaker among women in their 30s and 40s (OR = 1.4 and 1.1, respectively). The majority of patients were Hispanic whites (66% of cases and 79% of control subjects). Risk of Bartholin's duct abscess was greater among non-Hispanic white women (OR = 1.9) and black women (OR = 2.4). At lowest risk of this condition were women with high parity (> or = 4) or high gravidity (> or = 5). These findings suggest that the risk factor profile of this condition is similar to that of most sexually transmitted diseases. The advisability of presumptive antibiotic treatment of these patients and examination and treatment of their sexual partners should be considered.

Abscess↗
PubMed1994

Malignant mesothelioma: attributable risk of asbestos exposure.

OBJECTIVES: To evaluate a case-control study of malignant mesothelioma through patterns of exposure to asbestos based upon information from telephone interviews with next of kin. METHODS: Potential cases, identified from medical files and death certificates, included all people diagnosed with malignant mesothelioma and registered during 1975-1980 by the Los Angeles County Cancer Surveillance Program, the New York State Cancer Registry (excluding New York City), and 39 large Veterans Administration hospitals. Cases whose diagnosis was confirmed in a special pathology review as definite or probable mesothelioma (n = 208) were included in the analysis. Controls (n = 533) had died of other causes, excluding cancer, respiratory disease, suicide, or violence. Direct exposure to asbestos was determined from responses to three types of questions: specific queries as to any exposure to asbestos; occupational or non-vocational participation in any of nine specific activities thought to entail exposure to asbestos; and analysis of life-time work histories. Indirect exposures were assessed through residential histories and reported contact with family members exposed to asbestos. RESULTS: Among men with pleural mesothelioma the attributable risk (AR) for exposure to asbestos was 88% (95% confidence interval (95% CI) 76-95%). For men, the AR of peritoneal cancer was 58% (95% CI 20-89%). For women (both sites combined), the AR was 23% (95% CI 3-72%). The large differences in AR by sex are compatible with the explanations: a lower background incidence rate in women, lower exposure to asbestos, and greater misclassification among women. CONCLUSIONS: Most of the pleural and peritoneal mesotheliomas in the men studied were attributable to exposure to asbestos. The situation in women was less definitive.

Adult↗
PubMed1994

Type-specific immune response to human T cell lymphotropic virus (HTLV) type I and type II infections in Nigeria.

Type-specific antibody responses to human T cell lymphotropic virus type I (HTLV-I) and type II (HTLV-II) were studied in blood samples collected from 25 different locations in Nigeria between 1985 and 1991 and stored at the University College Hospital in Ibadan. A total of 4,153 sera were collected from participants in the National Immunity Survey of Viral Infections (n = 1,640), patients with tuberculosis (TB) (n = 140), patients with sexually transmitted diseases (STDs) (n = 876), patients with other medical conditions (n = 1,285), female prostitutes (n = 60), and health care workers (n = 152). The overall seroprevalence of HTLV was 5.6%, with similar rates among males and females. Using enzyme immunoassays that differentiated between antibodies to the two viruses, the seroprevalence rates were 2.5% for HTLV-I and 1.9% for HTLV-II, with an additional 1.2% of the samples dually reactive for both HTLV-I and HTLV-II. The seroprevalence rates for HTLV were low among children (0.8%) and adolescents (1.7%), with substantially higher rates among adults (range 5.0-7.4%). Age-specific patterns among adults appears to differ for HTLV-I and HTLV-II, with HTLV-I rates peaking above age 50 and HTLV-II rates peaking below age 50. The highest overall HTLV prevalence rates were observed for STD patients (16.3%), followed by female prostitutes (8.3%), TB patients (6.4%), health care workers (3.3%), patients with other medical conditions (3.2%), and immunity survey participants (1.8%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Breast cancer.

There is a four to fivefold variation in breast cancer incidence rates across different countries. The lowest rates are observed in Asia, and the highest rates are observed in western Europe and North America. The incidence of breast cancer has increased in all countries since 1960. We studied in detail (whenever possible) the changes in incidence and mortality between 1955 and 1990 in four age groups (35-44, 45-54, 55-64 and 65-74) for 11 "representative" countries (USA, England and Wales, Norway, Hungary, Yugoslavia, Spain, Colombia, Singapore, Japan, India and China). The largest increase in incidence took place in Japan and Singapore. The incidence rate for women aged 35-44 in Japan doubled between 1960 and 1985 and by 1985 was roughly two thirds the USA rate. There has been essentially no change in mortality rates in the USA, England and Wales or Norway, whereas there has been a 50-60% increase in Japan, Singapore and Hungary. Most of the observed increase in incidence rates in the USA, England and Wales and Norway may be "artefactual", that is, due to changes in screening patterns. Screening may also have contributed to the rate increase in other countries, but outside western Europe and North America the major part of the increase is likely to be due to changes in known and suspected breast cancer risk factors.

Adult↗
PubMed1994

Relationship of serum levels of oncostatin M to AIDS-related and classic Kaposi's sarcoma.

Serum levels of circulating oncostatin-M (OM) were compared among cases of Kaposi's sarcoma associated with acquired immune deficiency syndrome (AIDS-KS) and multiple controls, including a homosexual man infected with human immunodeficiency virus type 1 (HIV-1), an HIV-1-uninfected homosexual man, and a heterosexual man; and among classic KS cases and heterosexual controls. Cases were selected from abstracts collected by a population-based cancer registry and from local AIDS clinics. Controls for the AIDS-KS cases were matched to the cases by age, sex, and race and were either friends of the cases or residents from the cases' neighborhoods; controls for the classic KS cases were similarly matched, but were obtained solely from neighborhood residents. Blood samples were obtained from participants, serum levels of OM were determined by enzyme-linked immunosorbent assay (ELISA), and CD4 cell counts were obtained by flow cytometry. Geometric mean levels of OM were compared among the risk groups adjusted for age and CD4 cell count. No differences in adjusted OM levels were found between AIDS-KS cases and HIV-1-infected homosexual controls (8.4 pg/ml vs. 10.2) or between classic KS cases and controls (13.3 pg/ml vs. 9.6); however the HIV-1-infected controls (both homosexual and heterosexual) matched to the AIDS-KS cases had higher levels than did the HIV-1-infected cases and controls. Among the HIV-1-infected groups, an inverse correlation between OM and CD4 cell count was observed and was statistically significant for the cases. Among all heterosexual controls (matched to either case group), serum OM was inversely related to age.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1994

Heterotopic ossification following operative treatment of acetabular fracture. An analysis of risk factors.

A total of 237 patients with surgically treated acetabular fractures were analyzed to identify the risk factors predisposing to development of heterotopic ossification (HO) following operative treatment, and to evaluate both clinical significance of HO and the clinical outcome of operative excision of ectopic bone. All patients had a minimum of 1 year followup time. The degree of HO was determined from anteroposterior radiographs of the pelvis at the 1 year followup and was classified as Grade 0 or Grade 1 according to the amount of ectopic bone present. Forty patients (17%) who developed a moderate to severe amount of ectopic bone were classified as Grade 1. Nine who developed significant ectopic bone resulting in 20% or greater loss of hip motion underwent excision of the ectopic bone; all six available for followup showed an improvement in range of motion. A significant correlation was found between poor clinical results at the 1 year followup and Grade 1 ectopic bone formation (p < 0.001). Four factors found to highly correlate with Grade 1 ectopic bone formation were: (1) the iliofemoral surgical approach; (2) multiple (2 or more) operative findings; (3) T type fractures; and (4) the presence of associated injuries to the abdomen and chest.

Acetabulum↗
PubMed1993

Patterns of care.

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Adolescent↗
PubMed1993

Trends in patterns of treatment of childhood cancer in Los Angeles County.

To assess the proportion of children with cancer who have been managed by mainstream pediatric cancer programs, population-based cancer incidence data for Los Angeles County (LAC) children (under 20 years of age) for the years 1972 through 1987 were linked with patient records of children registered with the two national cooperative pediatric oncology groups, Children's Cancer Study Group and Pediatric Oncology Group. The proportion of children with cancer who were registered by cooperative groups increased markedly over time: 9% of LAC children younger than 15 years of age who were diagnosed with cancer in 1972 were registered with cooperative groups, compared to 52% of those diagnosed in 1980 and 62% of those diagnosed in 1987. Registration rates decreased with increasing age at cancer diagnosis. In the most recent time period, 1984-1987, 66% of LAC children diagnosed with cancer under age 5 years were registered with cooperative groups compared to 62% of those who were 5 to 9 years old and 49% of those who were 10 to 14 years old; although they were frequently diagnosed with tumors considered to be childhood cancers, only 19% of older adolescents (aged 15-19 years) were registered. In LAC, there was no apparent bias in registration rates with regard to gender or racial-ethnic background. Among patients diagnosed in the period 1984-1987, children in the highest of five socioeconomic status categories were underrepresented among registrants. Registration rates were highest (70% or greater) for patients with acute lymphocytic and acute nonlymphocytic leukemia, medulloblastoma, hepatoblastoma, Wilms tumor, and rhabdomyosarcoma. Fewer than 50% of patients with other brain and central nervous system tumors, retinoblastoma, other soft tissue sarcomas, and bone tumors were registered with the cooperative groups.

Adolescent↗
PubMed1993

Patterns of enrollment on cooperative group studies. An analysis of trends from the Los Angeles County Cancer Surveillance Program.

To assess the proportion of children diagnosed with cancer who are enrolled on studies conducted by the two national pediatric cooperative groups, population-based cancer incidence data for Los Angeles county children younger than age 20 for the years 1980 through 1987 were linked with patient records of children registered with the Childrens Cancer Group (CCG) or the Pediatric Oncology Group (POG). For patients not enrolled on a protocol, demographic and disease characteristics were compared with summary eligibility requirements for CCG protocols that were open for enrollment during 1980-1987. The proportion of patients enrolled on studies conducted by the cooperative groups varied with tumor type and age at diagnosis. When patients younger than the age of 10 were diagnosed at an institution affiliated with one of the groups, the majority of those evaluated by our review as eligible for a study were enrolled on a protocol. The proportion of young patients entered on study among those whose diagnosis was not made at a cooperative group institution was generally smaller. Seventy-three percent of all potentially eligible patients with acute leukemia diagnosed between 1980-1987 were entered on a pediatric group protocol. Approximately 50% of all potentially eligible patients with brain tumors were entered on protocol. In contrast to this, less than 50% of patients older than the age of 14 and likely to be eligible for a study were entered on a pediatric group protocol, regardless of the tumor type. Indeed, bone tumors constituted the category of patients most likely to be enrolled, with 39% of all potentially eligible patients entered on a study in the period examined. If the patient's diagnosis was made at a cooperative group institution, the individual was more likely to be entered on a protocol than if the diagnosis was made at a center outside the cooperative group network. It was not possible to determine the precise reason for this trend from the data available. Some explanations include policies at cooperative group institutions regarding admission of patients older than age 14 and the availability of protocols from cooperative groups primarily focused on the treatment of cancers of adults.

Adolescent↗
PubMed1993

The descriptive epidemiology of malignant cystosarcoma phyllodes tumors of the breast.

BACKGROUND: Malignant cystosarcoma phyllodes tumors of the breast are rare fibroepithelial tumors. The epidemiologic features of these malignancies in a defined population have not previously been described. METHODS: Incidence data were collected from 1972-1989 by the Cancer Surveillance Program, the population-based cancer registry for Los Angeles County. RESULTS: The average annual age-adjusted incidence rate of malignant cystosarcoma phyllodes is 2.1 per 1 million women. Latina whites have a higher risk of this cancer than other racial-ethnic groups. The age-incidence curve shows that risk of cystosarcoma phyllodes peaks in the 45-49-year-old age group, but the age patterns vary by race-ethnicity, with Asian and Latina patients significantly younger, on average, than non-Latina white patients. The incidence rates of malignant cystosarcoma phyllodes were substantially higher in the 1980s than in the 1970s, particularly among Latina whites and Asians. For Latina whites, birthplace is a significant predictor of risk. Women born in Mexico and Central and South America are at threefold to fourfold greater risk of malignant cystosarcoma phyllodes tumors than Latina whites born in the United States. CONCLUSIONS: The epidemiology of malignant cystosarcoma phyllodes tumors of the breast is strikingly different from that of the more common histologic types of breast cancer. The high risk in Latina immigrants may offer an important clue as to the cause of this rare tumor.

Adult↗