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oai:open-archive.highwire.org:amjepid:145/7/5712015-05-11HighWireOUPamjepid:145:7
Breast Size in Relation to Endogenous Hormone Levels, Body Constitution, and Oral Contraceptive Use in Healthy Nulligravid Women Aged 19-25 Years
Jemström, Helena
Olsson, Hakan
ORIGINAL CONTRIBUTIONS
In 1993 and 1994, the relation between breast size and hormonal factors and body constitution was studied in 65 healthy nulligravid women aged 19–25 years. Twenty-five women were current oral contraceptive users, 20 women were former users, and 20 women had never used oral contraceptives. Breast size was strongly positively correlated with current oral contraceptive use during menstrual cycle days 5–10, as well as days 18–23. No significant effect of former oral contraceptive use was seen on breast size. A significant increase in breast size between cycle days 5–10 and days 18–23 was seen among current oral contraceptive users. Breast size was significantly positively correlated with body mass index (weight (kg)/height (m)2), height, and weight in nonusers (i.e., former and never users combined) but not in current users. In nonusers, during the follicular phase, breast size was significantly positively associated with insulin-like growth factor 1. During the luteal phase, larger breast sizes were significantly associated with higher 17β-estradiol and progesterone levels and lower testosterone levels among nonusers. In models for current users, large breast sizes were significantly associated with high prolactin and luteinizing hormone levels and low follicle-stimulating hormone levels during cycle days 5–10. During cycle days 18–23, larger breast sizes correlated with low endogenous progesterone levels.
Oxford University Press
1997-04-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/145/7/571
http://dx.doi.org/10.1093/oxfordjournals.aje.a009153
en
Copyright (C) 1997, Oxford University Press
oai:open-archive.highwire.org:amjepid:145/7/5812015-05-11HighWireOUPamjepid:145:7
Familial and Personal Medical History of Cancer and Nervous System Conditions among Adults with Glioma and Controls
Wrensch, Margaret
Lee, Marion
Miike, Rei
Newman, Beth
Bargar, Geoffrey
Davis, Richard
Wiencke, John
Neuhaus, John
ORIGINAL CONTRIBUTIONS
The causes of glioma, the most common type of primary malignant brain tumor, are poorly understood. This study compared the personal and first-degree familial medical histones of 462 adults newly diagnosed with glioma in the San Francisco Bay Area between August 1, 1991, and March 31, 1994, with those of 443 controls who were frequency-matched on age, sex, and ethnicity. Cases and controls had equivalent personal histones of cancers other than brain cancer and most nervous system conditions, but they differed significantly regarding histories of epilepsy, seizures, or convulsions 3 or more years prior to diagnosis (odds ratio = 3.3, 95% confidence interval (CI) 1 4–7.9), chickenpox (odds ratio = 0.4, 95% CI 0.3–0.6), and shingles (odds ratio = 0.5, 95% CI 0.3–0.8). Four cases (less than 1%) and no controls had known genetic disorders (three had neurofibromatosis and one had tuberous sclerosis). Cases and controls had similar family histories of cancer and seizures. However, the odds ratio for a validated family history of primary brain tumor was 2 3 (95% CI 1.0–5.8). These results suggest that although family history of any cancer probably is not an important risk factor for adult glioma, a family history of brain tumors may play a role. Variation in exposure to or biologic response to common viral infections might play a greater role in the etiology of adult glioma than family history.
Oxford University Press
1997-04-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/145/7/581
http://dx.doi.org/10.1093/oxfordjournals.aje.a009154
en
Copyright (C) 1997, Oxford University Press
oai:open-archive.highwire.org:amjepid:145/7/5942015-05-11HighWireOUPamjepid:145:7
Does Prior Infection with Varicella-Zoster Virus Influence Risk of Adult Glioma?
Wrensch, Margaret
Weinberg, Adriana
Wiencke, John
Masters, Helen
Miike, Rei
Barger, Geoffrey
Lee, Marion
ORIGINAL CONTRIBUTIONS
To evaluate a possible association between varicella-zoster virus infection and glioma, the authors asked adults with glioma (<it>n</it> = 462) whose tumors were diagnosed between August 1, 1991, and March 31, 1994, and age-, sex-, and ethnicity-matched controls (<it>n</it> = 443) about their histories of chickenpox or shingles. Cases were significantly less likely than controls to report a history of either chickenpox (odds ratio = 0.4, 95% confidence interval (CI) 0.3–0.6) or shingles (odds ratio = 0.5, 95% CI 0.3–0.8). To obtain serologic support for these findings, the authors conducted double-blind enzyme-linked immunosorbent assays for immunoglobulin G antibodies to varicella-zoster virus among 167 self-reporting subjects for whom blood samples were available. Cases and controls reporting no history of chickenpox were equally likely to test positive (73% vs. 75%), but among those reporting a positive history, cases were less likely than were controls to test positive (71% vs. 85%). Despite the misclassification, an odds ratio of 0.6 was obtained using either serologic data (95% CI 0.3–1.3) or reported history of chickenpox (95% CI 0.3–1.1) in this subgroup of subjects. This suggests that adults with glioma were less likely than controls either to have had prior varicella-zoster virus infection or to have an immunoglobulin G antibody response adequate to indicate positivity. Since either explanation suggests novel mechanisms for brain tumor pathogenesis, these findings require corroboration and elaboration.
Oxford University Press
1997-04-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/145/7/594
http://dx.doi.org/10.1093/oxfordjournals.aje.a009155
en
Copyright (C) 1997, Oxford University Press
oai:open-archive.highwire.org:amjepid:145/7/5982015-05-11HighWireOUPamjepid:145:7
Serum Potassium, Cigarette Smoking, and Mortality in Middle-aged Men
Wannamethee, S. Goya
Lever, Anthony F.
Shaper, A. Gerald
Whincup, Peter H.
ORIGINAL CONTRIBUTIONS
The relation between serum potassium level and all-cause mortality was examined in a prospective study of 7,636 middle-aged British men followed for 11.5 years (1978–1991). Men being treated for hypertension had a significantly lower mean (± standard error) potassium level than men not in treatment (4.24 ± 0.03 mmol/liter vs. 4.32 ± 0.01 mmol/liter; <it>p</it> < 0.01). During the follow-up period of 11.5 years, after exclusion of the 374 men under antihypertensive treatment, there were 771 deaths from all causes in the remaining 7,262 men. A low potassium level (<3.7 mmol/liter) was not associated with increased mortality. Elevated potassium levels ≥5.2 mmol/liter were associated with a significant increase in mortality, particularly noncardiovascular deaths, even after adjustment for potentially confounding factors. However, serum potassium was strongly related to smoking, and the increased nsk of mortality associated with elevated potassium was seen only among current smokers. In current smokers with raised potassium levels (≥5.2 mmol/liter) compared with smokers with levels under 5.2 mmol/liter, the relative risks of mortality were 1.7 (95% confidence interval (CI) 1.2–2.5) for deaths from all causes, 1.8 (95% CI 1.0–3.2) for all cancer deaths, and 2.5 (95% CI 1.1–5.6) for lung cancer deaths. In the 374 men receiving regular antihypertensive treatment, a low potassium level was not associated with excess mortality; those with raised potassium levels had excess risks for both cardiovascular and noncardiovascular deaths. The findings suggest that either raised potassium levels in association with smoking have an influence on the risk of death from noncardiovascular disease, particularly lung cancer, or a raised serum potassium level is a marker for some other risk factor associated with smoking. The prognostic and therapeutic implications of these observations warrant further exploration.
Oxford University Press
1997-04-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/145/7/598
http://dx.doi.org/10.1093/oxfordjournals.aje.a009156
en
Copyright (C) 1997, Oxford University Press
oai:open-archive.highwire.org:amjepid:145/7/6072015-05-11HighWireOUPamjepid:145:7
Hypertension, Diuretics, and Antihypertensive Medications as Possible Risk Factors for Renal Cell Cancer
Heath, Clark W.
Lally, Cathy A.
Calle, Eugenia E.
McLaughlin, Joseph K.
Thun, Michael J
ORIGINAL CONTRIBUTIONS
The authors examined the relation of hypertension, use of diuretics, and use of antihypertensive medications to the risk of fatal renal cell cancer in a prospective cohort study of 998,904 adult Americans followed for 7 years (1982–1989). Analysis included 335 renal cell cancer deaths (123 in women and 212 in men). Cox proportional hazards modeling was used to calculate rate ratios. Increased rate ratios were present for cigarette smoking in men and for elevated body mass index in both sexes. Significantly increased age-matched rate ratios, independent of smoking and body mass index, were present for hypertension, use of diuretics, and use of hypertension medications, but only for women. Multivariate testing confined these risks to hypertensive women who were using hypertension medications alone (rate ratio = 2.2, 95% confidence interval 1.4–3.5) or with diuretics (rate ratio = 2.5, 95% confidence interval 1.5–4 3). Risk was not significantly increased for either men or women who had untreated hypertension or who used diuretics alone with or without hypertension. These findings partly support those of earlier studies suggesting that medications related to treatment of hypertension, or the seventy of hypertension itself, may contribute to the etiology of renal cell cancer.
Oxford University Press
1997-04-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/145/7/607
http://dx.doi.org/10.1093/oxfordjournals.aje.a009157
en
Copyright (C) 1997, Oxford University Press
oai:open-archive.highwire.org:amjepid:145/7/6142015-05-11HighWireOUPamjepid:145:7
Body Fat Distribution and Risk of Non-Insulin-dependent Diabetes Mellitus in Women: The Nurses' Health Study
Carey, Vincent J.
Walters, Ellen E.
Colditz, Graham A.
Solomon, Caren G.
Willet, Walter C.
Rosner, Bernard A.
Speizer, Frank E.
Manson, JoAnn E.
ORIGINAL CONTRIBUTIONS
Obesity is an established risk factor for non-insulin-dependent diabetes mellitus (NIDDM). Anthropometric measures of overall and central obesity as predictors of NIDDM risk have not been as well studied, especially in women. Among 43,581 women enrolled in the Nurses' Health Study who in 1986 provided waist, hip, and weight information and who were initially free from diabetes and other major chronic diseases, NIDDM incidence was followed from 1986 to 1994. After adjustment for age, family history of diabetes, smoking, exercise, and several dietary factors, the relative risk of NIDDM for the 90th percentile of body mass index (BMI) (weight (kg)/height (m)2) (BMI = 29.9) versus the 10th percentile (BMI = 20.1) was 11.2 (95% confidence interval (CI) 7.9–15.9). Controlling for BMI and other potentially confounding factors, the relative risk for the 90th percentile of waist: hip ratio (WHR) (WHR = 0.86) versus the 10th percentile (WHR = 0.70) was 3 1 (95% CI 2.3–4.1), and the relative risk for the 90th percentile of waist circumference (36.2 inches or 92 cm) versus the 10th percentile (26.2 inches or 67 cm) was 5.1 (95% CI 2.9–8.9). BMI, WHR, and waist circumference are powerful independent predictors of NIDDM in US women. Measurement of BMI and waist circumference (with or without hip circumference) are potentially useful tools for clinicians in counseling patients regarding NIDDM risk and risk reduction.
Oxford University Press
1997-04-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/145/7/614
http://dx.doi.org/10.1093/oxfordjournals.aje.a009158
en
Copyright (C) 1997, Oxford University Press
oai:open-archive.highwire.org:amjepid:145/7/6202015-05-11HighWireOUPamjepid:145:7
Relation between Body Mass Index and Body Fat in Black Population Samples from Nigeria, Jamaica, and the United States
Luke, Amy
Durazo-Arvizu, Ramón
Rotimi, Charles
Prewitt, T. Elaine
Forrester, Terrence
Wilks, Rainford
Ogunbiyi, Olufemi J.
Schoeller, Dale A.
McGee, Daniel
Cooper, Richard S.
ORIGINAL CONTRIBUTIONS
Body mass index (BMI) is the most commonly used measure of obesity. Recently, some investigators have advocated direct measurement of adiposity rather than use of the BMI. This study was undertaken to determine the ability of BMI to predict body fat levels in three populations of West African heritage living in different environments. A total of 1,054 black men and women were examined in Nigeria, Jamaica, and the United States during 1994 and 1995. A standardized protocol was used to measure height, weight, waist and hip circumferences, and blood pressure at all sites; percentage of body fat was estimated using bioelectrical impedance analysis. Percentage of body fat and BMI were highly correlated within site- and sex-specific groups, and the resulting <it>r</it>2 ranged from 0.61 to 0.85. The relation was quadratic in all groups except Nigerian men, in whom it was linear. The regression coefficients were similar across sites, yet the mean body fat levels differed significantly (<it>p</it> < 0.001) as estimated by the intercept, making intersite comparison difficult. Compared with BMI, percentage of body fat was not a better predictor of blood pressure or waist or hip circumference.
Oxford University Press
1997-04-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/145/7/620
http://dx.doi.org/10.1093/oxfordjournals.aje.a009159
en
Copyright (C) 1997, Oxford University Press
oai:open-archive.highwire.org:amjepid:145/7/6292015-05-11HighWireOUPamjepid:145:7
Progression to Acquired Immunodeficiency Syndrome Is Influenced by CD4 T-Lymphocyte Count and Time Since Seroconversion
Begtrup, Kamilla
Melbye, Mads
Biggar, Robert J.
Goedert, James J.
Knudsen, Kim
Anderson, Per Kragh
ORIGINAL CONTRIBUTIONS
Progression to acquired immunodeficiency syndrome (AIDS) among persons infected with human immunodeficiency virus (HIV) varies considerably and may be influenced by factors such as age, smoking, number of male partners per year, and CD4 T-lymphocyte count. The loss of CD4 lymphocytes is known to be the dominant factor in the progression to AIDS. However, it is unclear whether the effect of the CD4 lymphocyte count is of such importance that persons with similar CD4 cell counts who have been infected for widely different lengths of time have the same risk of AIDS. While a CD4 count is easily obtainable, the precise amount of time since HIV infection is in most circumstances difficult to assess. In the present analysis, 259 Danish and 245 American homosexual men were followed for up to 14 years from 1981 to 1995. Two hundred and one persons seroconverted during the study period, and 112 had developed AIDS before the end of follow-up. CD4 lymphocyte count was highly correlated with the risk of developing AIDS (<it>p</it> < 0.001), but AIDS risk was not affected significantly by either age at infection, smoking, or number of male partners per year (<it>p</it> > 0.20 in all cases). Controlled for CD4 lymphocyte count, time since seroconversion was significant in explaining the risk of AIDS (<it>p</it> = 0.018), with a lower risk being seen during the first 3 years after seroconversion but no effect thereafter. These data confirm the central importance of CD4 lymphocyte level in the progression of HIV disease to AIDS, and suggest that rapid progression within 3 years of infection may be related to factors other than CD4 cell count.
Oxford University Press
1997-04-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/145/7/629
http://dx.doi.org/10.1093/oxfordjournals.aje.a009160
en
Copyright (C) 1997, Oxford University Press
oai:open-archive.highwire.org:amjepid:145/7/6362015-05-11HighWireOUPamjepid:145:7
Frequency of Sexual Partner Change in a Norwegian Population: Data Distribution and Covariates
Stigum, Hein
Magnus, Per
Harns, Jennifer R.
Samuelsen, Sven Ove
Bakketeig, Leiv S.
ORIGINAL CONTRIBUTIONS
The number of new sexual partners per year (partner frequency) is a key factor in the spread of sexually transmitted diseases. Data from two Norwegian population-based surveys conducted in 1987 and 1992 were used to estimate recent (in the previous 3 years) and earlier partner frequency and to examine covariates affecting the distribution of partner frequency. Seventy-two percent of respondents reported having no new partners per year, and 2% reported having more than three new partners per year. Results from a Poisson regression model indicated that a low partner frequency was associated with being married or cohabiting, being female, greater age, and late sexual debut. Partner frequency was lower in 1992 than in 1987 (rate ratio = 0.8, 95% confidence interval 0.7–0.9). In comparison with earlier life, there was a large reduction in partner frequency for married/cohabiting individuals. In contrast, there was either no change or some increase in partner frequency for single persons.
Oxford University Press
1997-04-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/145/7/636
http://dx.doi.org/10.1093/oxfordjournals.aje.a009161
en
Copyright (C) 1997, Oxford University Press
oai:open-archive.highwire.org:amjepid:145/7/6442015-05-11HighWireOUPamjepid:145:7
Effect of Changing Partnership Formation Rates on the Spread of Sexually Transmitted Diseases and Human Immunodeficiency Virus
Stigum, Hein
Magnus, Per
Bakketeig, Leiv S.
ORIGINAL CONTRIBUTIONS
Core population groups play an important role in the spread of sexually transmitted diseases. Subjects in a core group may change their behavior over time and “migrate” to the noncore. The authors examined the effects of such migration on the prevalence of gonorrhea, chlamydia, and human immunodeficiency virus (HIV) using a mathematical model. The size of the core and the migration rate from the core to the noncore were estimated from population-based sexual survey data on 8,445 Norwegians collected in 1987 and 1992. Sixty-four percent of the sample was considered without risk of contracting a sexually transmitted disease. The core group made up 2.5% of the remaining sample. The migration rate from the core was estimated at 12% per year. The three types of infections analyzed exemplify three different patterns of the effect of migration on infection prevalence in the core/noncore groups: gonorrhea = no effect–no effect, chlamydia = no effect/increase, and HIV = decreas/increase. Migration affects the basic reproductive ratio of diseases with a long infectious period more than that of diseases with a short infectious period. For HIV, this means that the later stages of infection contribute less to the basic reproductive ratio in the presence of migration. The results are qualitative and show that detailed knowledge about mixing, migration, transmission rates, and duration of infectiousness is necessary to make accurate predictions.
Oxford University Press
1997-04-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/145/7/644
http://dx.doi.org/10.1093/oxfordjournals.aje.a009162
en
Copyright (C) 1997, Oxford University Press
oai:open-archive.highwire.org:amjepid:145/7/6532015-05-11HighWireOUPamjepid:145:7
Hospital Controls versus Community Controls: Differences in Inferences Regarding Risk Factors for Hip Fracture
Moritz, Deborah J.
Kelsey, Jennifer L.
Grisso, Jeanne Ann
ORIGINAL CONTRIBUTIONS
In case-control studies using cases identified from persons admitted to hospitals, two types of controls are most often used: persons from the communities served by the hospitals and persons admitted to the same hospitals as those to which the cases were admitted. It is often unclear which is the more appropriate choice, and whether the use of one or the other type of control group will lead to biased conclusions. The purpose of the present analysis was to determine whether the choice of hospital controls versus community controls would influence conclusions regarding risk factors for hip fracture. Cases (<it>n</it> = 425), hospital controls (<it>n</it> = 312), and community controls (<it>n</it> = 454) were drawn from a case-control study of risk factors for hip fracture in women. Study participants were white and black women aged 45 years or older and living in New York City or Philadelphia, Pennsylvania, who were selected between September 1987 and July 1989. Using community controls but not hospital controls, investigators would have concluded that having a fall during the previous 6 months, current smoking, and moving during the previous year were associated with an increased risk of hip fracture. Associations of hip fracture risk with stroke and prior use of ambulatory aids were stronger using community controls, but associations with estrogen use and body mass index were not influenced by choice of control group. Community controls were quite similar to representative samples of community-dwelling elderly women, whereas hospital controls were somewhat sicker and more likely to be current smokers. The authors conclude that community controls comprise the more appropriate control group in case-control studies of hip fracture in the elderly.
Oxford University Press
1997-04-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/145/7/653
http://dx.doi.org/10.1093/oxfordjournals.aje.a009163
en
Copyright (C) 1997, Oxford University Press
oai:open-archive.highwire.org:amjepid:145/7/6612015-05-11HighWireOUPamjepid:145:7
Biologic Synergism and Parallelism
Darroch, John
ORIGINAL CONTRIBUTIONS
In epidemiologic studies of two binary exposure factors, much attention has been given to the concept of synergism of the factors. The leading dictionary of epidemiology offers two definitions of synergism, one of which this author labels statistical and the other biologic. The epidemiologic literature has been largely concerned with statistical synergism, which is typically measured using additive or multiplicative interaction. This paper focuses on biologic synergism, on the related concept of biologic parallelism, and on the question of how much information can be gleaned about population amounts of biologic synergism and parallelism— information which is of vital interest to epidemiologists. A fundamental identity equates the difference between the amounts of biologic synergism and parallelism to the additive interaction. Two biologic models, the multistage model and the no-hit or immunity model, enhance the interpretation of multiplicative interaction as a measure of statistical synergism, but it is pointed out here that, unfortunately, both models incorporate the strong assumption that there is no parallelism. A third model, the single–hit or vulnerability model, makes the even stronger assumption that there is no biologic synergism and consequently that the additive interaction is equal to minus the amount of parallelism A consequence of this fact is that a link which has been perceived in the literature to exist between the single-hit model and the additive interaction is false.
Oxford University Press
1997-04-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/145/7/661
http://dx.doi.org/10.1093/oxfordjournals.aje.a009164
en
Copyright (C) 1997, Oxford University Press
oai:open-archive.highwire.org:amjepid:145/7/669-a2015-05-11HighWireOUPamjepid:145:7
THE AUTHORS REPLY
Swanson, Christine A.
Potischman, Nancy
Brinton, Louise A.
LETTERS TO THE EDITOR
Oxford University Press
1997-04-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/145/7/669-a
http://dx.doi.org/10.1093/oxfordjournals.aje.a009166
en
Copyright (C) 1997, Oxford University Press
oai:open-archive.highwire.org:amjepid:145/7/6692015-05-11HighWireOUPamjepid:145:7
RE: "BODY SIZE AND BREAST CANCER RISK AMONG WOMEN UNDER AGE 45 YEARS"
Gerber, Mariette
LETTERS TO THE EDITOR
Oxford University Press
1997-04-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/145/7/669
http://dx.doi.org/10.1093/oxfordjournals.aje.a009165
en
Copyright (C) 1997, Oxford University Press
oai:open-archive.highwire.org:amjepid:145/7/670-a2015-05-11HighWireOUPamjepid:145:7
THE AUTHORS REPLY
Ford, Earl S.
Freedman, David S.
Byers, Tim
LETTERS TO THE EDITOR
Oxford University Press
1997-04-01 00:00:00.0
TEXT
text/html
http://aje.oxfordjournals.org/cgi/content/short/145/7/670-a
http://dx.doi.org/10.1093/oxfordjournals.aje.a009168
en
Copyright (C) 1997, Oxford University Press
oai:open-archive.highwire.org:amjepid:145/7/6702015-05-11HighWireOUPamjepid:145:7
RE: "BALDNESS AND ISCHEMIC HEART DISEASE IN A NATIONAL SAMPLE OF MEN"
Sheikh, Kazim
LETTERS TO THE EDITOR
Oxford University Press
1997-04-01 00:00:00.0
TEXT
text/html
http://aje.oxfordjournals.org/cgi/content/short/145/7/670
http://dx.doi.org/10.1093/oxfordjournals.aje.a009167
en
Copyright (C) 1997, Oxford University Press