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Biomedical subjects

M Szklo

Publications and source records attributed to M Szklo.

At least 109 records · Page 6Linked to original sources
PubMed1986

Estrogen receptors and breast cancer.

The literature indicates that relationships between epidemiologic variables and estrogen receptor activity are not clearly defined. Conflicting and unconfirmed results have been published. Most studies have been based on clinical case series rather than on carefully conducted population-based epidemiologic investigations. In addition, previous reports have not generally considered the potential role of confounding and interaction in the interpretation of the associations reported between estrogen receptor status and risk factors for breast cancer. Given these considerations, the need for further research in this area is obvious. Application of an estrogen receptor scheme (positive vs. negative) for defining breast cancer may allow delineation of cases that may appear quite similar but that represent two different types of disease. Estrogen receptor-positive and estrogen receptor-negative breast cancer behave differently biologically, have different treatment and prognostic implications, and thus may also possibly have different risk factor patterns. Moreover, the extent to which receptor status reflects effects associated with exposure, the disease process, or host influences is not clearly understood. There is some evidence that estrophilin is a biochemical marker of tumor differentiation. Moolgavkar et al. suggested that all breast cancers are initially estrogen receptor-positive, but that as the tumor undergoes clonal evolution and becomes more undifferentiated, the ability to express estrophilin is lost in some cases. If this is true, estrogen receptor results may reflect temporal changes in the biologic characteristics of the tumor as it progresses from a well differentiated to a poorly differentiated state. Receptor status could also reflect changes in host resistance and tumor aggressiveness. This concept is consistent with previous observations that anaplastic, rapidly growing cancers are less likely to be receptor-positive. It has not been established whether estrogen receptor-negative tumors represent an advanced stage of the disease or arise de novo. Clinical studies have failed to demonstrate a relationship between extent of disease at diagnosis and receptor results. Estrophilin concentrations also are apparently not related to stage of disease, lending no support for the notion that receptor level declines with progression of the disease. It is possible that certain etiologic factors lead to the natural selection and growth of receptor-negative cells and that receptor negativity is an early, inherent characteristic of some breast cancers.(ABSTRACT TRUNCATED AT 400 WORDS)

Breast Neoplasms↗
PubMed1986

Determination of blood pressure in children.

The present paper reviews the epidemiologic patterns of blood pressure in children by demographic variables such as age, race, sex, education and social class. Other possible determinants for high blood pressure in both adults and children are also discussed, including obesity and salt intake. Special attention is given to the phenomenon of tracking and to genetic influences in blood pressure, the latter discussed in the context of the strengths and limitations of twin and familial aggregation studies.

Blood Pressure↗
PubMed1986

Chronic lymphocytic leukemia and acquired disorders affecting the immune system: a case-control study.

The relationship of a number of subacute or chronic infectious diseases, connective tissue or autoimmune disorders, allergic conditions, and surgical excision of lymphoid tissue with chronic lymphocytic leukemia (CLL) was examined in a case-control study involving 342 cases and 342 matched controls. In both analyses of all matched pairs and those pairs in which both subjects were respondents, no statistically significant association was found between a history of subacute viral infections or subacute and chronic bacterial infections and CLL. Connective tissue or autoimmune disorders also were found not to be associated with CLL. Examination of the association between several allergic conditions and CLL suggested a protective effect as did a "dose-response" analysis, although none of the individual disorders showed a statistically significant relationship; however, a test for linear trend was significant (P = .04). Similarly, examination of the relationship between surgical excision of lymphoid tissue in several anatomic locations and CLL showed a protective effect, statistically significant for tonsillectomy-adenoidectomy (odds ratio = 0.69; 95% confidence interval = 0.48, 0.98). A statistically significant negative dose-response relationship, substantiating the protectiveness of the effect, was found.

Aged↗
PubMed1986

Incidence of aplastic anemia in a three county area in South Carolina.

An apparent cluster of four aplastic anemia (AA) cases in teenagers residing in a small South Carolina town was further investigated. Incidence of AA in all age groups in a surrounding three county area (TCA) over a 12-year time interval was determined and compared with AA incidence rates in Baltimore, representing the only known population based United States incidence data. The same general age-specific incidence pattern (based on 27 cases in the TCA and 118 in Baltimore) was found in the two areas, both overall and for the four race-sex groups. Although based on small numbers, nonwhite average annual age-adjusted rates for males and females were higher in the TCA (6.8 and 13.7 per million) than in Baltimore (4.7 and 7.3). For whites, TCA rates were 11.7 and 5.4 (for males and females) and Baltimore rates were 7.1 and 5.4. The differences for non-whites in the two areas may indicate a greater prevalence of risk factors for AA in the TCA than in Baltimore, but the small numbers of cases and the lack of comparable data from other areas of the country, together with the possibility of misdiagnosis of the disease, make definitive conclusions impossible.

Age Factors↗
PubMed1985

An apparent cluster of aplastic anemia in a small population of teenagers.

Four teenagers with severe aplastic anemia, initially diagnosed and evaluated over a seven-year period at The Johns Hopkins Bone Marrow Transplant Unit, Baltimore, were residents of the same small town in South Carolina. Estimated annual incidence for that age group in the town, based on the four cases, was 100 times the expected rate. All four of the teenagers had attended one of two junior high schools. An exploratory survey of all high-school students, comparing risk factors of those who had attended the "affected" junior high school with those who had attended the "unaffected" junior high school, showed no associations with exposure to glue, paint or varnishes, pesticides, history of hepatitis or infectious mononucleosis, or use of chloramphenicol or other suspected drugs. Weak associations were found between the affected junior high school and employment in the textile industry and in agriculture (specifically peach orchards).

Adolescent↗
PubMed1985

Incidence of aplastic anemia in metropolitan Baltimore: a population-based study.

Incidence rates for aplastic anemia (AA) so far have been unavailable for defined populations in the United States. A study was carried out in the Baltimore Standard Metropolitan Statistical Area (SMSA) to examine the incidence rates for aplastic anemia from 1970 through 1978. Cases of AA (N = 118) were identified through medical records (N = 77) in SMSA hospitals and death certificates (N = 41). All medical charts were reviewed by an oncologist-hematologist for validation purposes. Among whites, average annual age-adjusted incidence rates per million were higher in males (7.1) than in females (5.4), whereas in nonwhites, females had a higher rate (7.3) than males (4.7). None of the sex differences was statistically significant. Age-specific incidence rates were consistently low in young ages, with an exponential increase after age 40. Examination of time trends did not suggest changes in whites, although in blacks, mainly in males, there was a suggestion of a temporal increase. However, rates in blacks were based on small numbers, and trends were not statistically significant. An inconsistent sex differential, as well as the relative stability of rates over time at least in whites, suggests that although sexes may have different types of exposures, occupational exposures and changes in environmental factors over time cannot entirely explain the occurrence of AA in the population. In addition, the age pattern suggests that future studies should examine etiologic agents separately for the younger and the older subjects with AA.

Adolescent↗
PubMed1984

Estrogen use and myocardial infarction risk: a case-control study.

A case-control study was conducted to examine the relationship of estrogen use to myocardial infarction in postmenopausal white women. After exclusion of proxy responses and of controls with discharge diagnoses of gynecologic or gallbladder diseases, there remained 39 matched sets (33 pairs and 6 triplets). The unadjusted relative odds ratio (RO) for past estrogen use was found to be 0.83. However, after simultaneous adjustment for cardiovascular diseases, smoking, education, and type of menopause, the net RO was 0.61. Type of menopause was found to interact with estrogen use, in that the protective effect was seen mainly in surgical menopause women, in whom the net RO for estrogen use was 0.37. Although none of the results reached statistical significance, they are consistent with recent results indicating a protective effect for estrogen therapy in regard to coronary heart disease, mainly among women undergoing surgical menopause.

Adult↗
PubMed1983

Epidemiologic study of insect allergy in children. II. Effect of accidental stings in allergic children.

One hundred eighty-one children with non-life-threatening reactions to insect stings and positive venom skin tests were randomized to treatment (53) or no-treatment (128) groups and followed up clinically and immunologically for at least two years to assess the results of accidental stings. Twenty-eight stings in 17 treated patients and 74 stings in 47 untreated children occurred, leading to one mild reaction in a treated patient, and eight in the no-treatment group (P = NS). No reaction was more serious than the original. Based on IgE antibody changes and skin test results, 87% of the untreated children were stung by an insect to which they had clinical sensitivity by skin test. Vespid skin test sensitivity decreased 10-fold or more in both treated (72%) and untreated (44%) children. Of those with increased sensitivity, congruent to 70% had been stung. These data indicate that the incidence of severe reactions on resting is low in insect-allergic children, and that the majority show decreased skin test sensitivity over time.

Adolescent↗
PubMed1983

The impact of marital status on survival after an acute myocardial infarction: a population-based study.

A nonconcurrent prospective study was conducted in the metropolitan Baltimore, Maryland, area to examine the influence of marital status on the in-hospital and long-term survival rate of 1401 patients who experienced an acute myocardial infarction. Patients were classified as "married" or "unmarried" at the time of their myocardial infarction and any later change in the marital history was not considered. For married males the adjusted in-hospital case fatality rate was 19.7 per cent, whereas for unmarried males the rate was 26.7 per cent (p less than 0.05); similarly, the case fatality rate for married and unmarried females was 23.3 per cent and 37.4 per cent, respectively (p less than 0.05). A 10-year follow-up of 888 subjects who were discharged alive after an acute myocardial infarction also showed a significantly better survival rate for the married compared to the unmarried for both males (p less than 0.0001) and females (p less than 0.025). The results of this study indicate that married men and women who experience an acute myocardial infarction have a significantly better survival prospect, both in-hospital and after discharge, independent of other factors.

Female↗
PubMed1982

An epidemiologic study of insect allergy in children. I. Characteristics of the disease.

Of 235 children with a history of allergic reactions to insect stings studied, 59 had severe life-threatening systemic reactions, 123 had mild, non-life-threatening systemic reactions, and 53 had large local reactions. The overall male-female ratio was 2:1. Venom skin tests were positive in approximately 89% of each group. Prior whole body extract therapy increased the likelihood of venom skin test reactivity to multiple insect venoms from 51 to 78%. Venom skin test results did not correlate with the severity of previous allergic reactions. One hundred and nine children with NLTR and positive venom skin tests were entered into one of two groups--venom immunotherapy or observation only. During the first six months the treatment group had the expected fourfold rise in venom-specific IgE antibody titers, whereas the observation group had a decline of the mean IgE titer. Patients in the observation group who were accidentally stung had a transient rise in IgE antibody titers. The small number of accidental stings which occurred in both groups resulted in reactions milder than the original reactions. Although based on preliminary data, venom immunotherapy may not be necessary for some children with previously mild systemic symptoms.

Adolescent↗
PubMed1982

Oral contraceptives and breast cancer.

A case-control interview study, conducted among participants in the Breast Cancer Detection Demonstration Project and involving 963 breast cancer cases and 858 controls, allowed evaluation of the risk of breast cancer associated with use of oral contraceptives. Overall, there was no association between use and risk of disease (RR = 1.1). In addition, there was no indication of increasing risk with years of use or years since initial use, despite slight excess risks observed among users of high-dose preparations. Premenopausal women who used the pill after the age of 40 demonstrated approximately a 50% increased risk, possibly as a result of artificial prolongation of a premenopausal rate of disease incidence. Non-significant excess risks associated with pill use were also seen among premenopausal women who reported a family history of breast cancer in a sister (RR = 3.6) or previous biopsies for benign breast disease (RR = 3.2). The latter excess was limited to women whose use of the pill preceded a first biopsy, suggesting that the types of lesions requiring biopsy among current long-term pill users may be those that predispose to breast cancer.

Adult↗
PubMed1982

Causes of death in a widowed population.

Causes of death of widowed and married were compared in a nonconcurrent prospective study in Washington County, Maryland, which identified 4032 white persons aged 18 years and over who were enumerated in a 1963 nonofficial census and who became widowed between 1963 and 1974, and an equal number of married persons, each matched to a widowed person as to race, sex, year of birth, and geography of residence. Underlying causes of death were obtained from the death certificates of those who had died. Deaths from infectious diseases, accidents, and suicide were significantly higher than expected among widowed males, and deaths from cirrhosis of the liver were significantly higher than expected among widowed females. The similarity in causes of death of the widowed and their predeceased spouses was no greater than expected to occur by chance. There was no indication that widowed males or females suffering from chronic diseases, as defined by duration of underlying causes of death being two years or more, suffered earlier mortality after bereavement than others.

Adolescent↗
PubMed1982

Parental occupations and cancer in children--a case-control study and review of the methodologic issues.

The findings of a number of published reports have been conflicting with regard to the role of parental occupation in the occurrence of cancer in children. In the present study, the occupations and occupational exposures of parents before and after the birth of a child who later developed leukemia or a brain tumor (cases) were compared with the occupational experience of parents of children with other cancers and of normal children. Forty-three children diagnosed with leukemia from 1969 through 1974 and 70 children diagnosed with brain tumors from 1965 through 1974 in the Baltimore Standard Metropolitan Statistical Area were ascertained. The findings of the present study do not demonstrate a relationship between parental occupation and occurrence of leukemia or brain tumors in the offspring. The results of this and other studies are evaluated in the context of a number of important but difficult methodologic issues that arise in studies of this potentially significant subject area.

Brain Neoplasms↗
PubMed1981

An apparent increase in the incidence of acute nonlymphocytic leukemia in black children.

A community-wide study was conducted to examine time trends in incidence rates of leukemia in children. Cases of acute leukemia, both lymphocytic (ALL) and nonlymphocytic (ANLL), newly diagnosed in children ages 0-19 years in the Baltimore area from 1960 to 1974 were ascertained. Over the 15 years, 286 children with acute leukemia were identified, of whom 77% had ALL. Incidence rates of ALL were two to three times as high in whites as in blacks, and remained virtually unchanged over time. However, the picture was quite different for ANLL. Initially, incidence rates were higher in whites than in blacks, but during the final five years the incidence increased dramatically in blacks so that it actually exceeded the rate among whites. The increase of ANLL in black children occurred primarily in blacks of high socioeconomic status. This suggests that the increase may have resulted from environmental influences associated with upward socioeconomic mobility in the black population in recent years.

Adolescent↗
PubMed1981

Menopausal estrogen use and risk of breast cancer.

To assess the relationship of menopausal estrogens to breast cancer risk, the authors conducted a case-control study among 881 cases and 863 controls identified through the Breast Cancer Detection Demonstration Project (BCDDP). Use of estrogens was associated with a relative risk (RR) of 1.24 (95% C.I. 1.0-1.5), with higher risks observed among users of high-dose preparations. Hormone effects predominated among women who received them following bilateral oophorectomy (RR = 1.54), obliterating the protective effect normally associated with the operation. In this group, risk increased with years of estrogen use, reaching risks of 2-3 for users of ten or more years. High risks were also observed among oophorectomized women who used hormones in the presence of other risk factors, including nulliparity, family history of breast cancer, and benign breast disease. These results suggest a possible, although complex, relationship between estrogen use and risk of breast cancer.

Adult↗