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Biomedical subjects

B A Rosner

Publications and source records attributed to B A Rosner.

At least 73 records · Page 4Linked to original sources

Relation of meat, fat, and fiber intake to the risk of colon cancer in a prospective study among women.

BACKGROUND: The rates of colon cancer in various countries are strongly correlated with the per capita consumption of red meat and animal fat and, to a lesser degree, inversely associated with the consumption of fiber. METHODS: We conducted a prospective study among 88,751 women 34 to 59 years old and without a history of cancer, inflammatory bowel disease, or familial polyposis who completed a dietary questionnaire in 1980. By 1986, during 512,488 person-years of follow-up, 150 incident cases of colon cancer had been documented. RESULTS: After adjustment for total energy intake, animal fat was positively associated with the risk of colon cancer (P for trend = 0.01); the relative risk for the highest as compared with the lowest quintile was 1.89 (95 percent confidence interval, 1.13 to 3.15). No association was found for vegetable fat. The relative risk of colon cancer in women who ate beef, pork, or lamb as a main dish every day was 2.49 (95 percent confidence interval, 1.24 to 5.03), as compared with those reporting consumption less than once a month. Processed meats and liver were also significantly associated with increased risk, whereas fish and chicken without skin were related to decreased risk. The ratio of the intake of red meat to the intake of chicken and fish was particularly strongly associated with an increased incidence of colon cancer (P for trend = 0.0005); the relative risk for women in the highest quintile of this ratio as compared with those in the lowest quintile was 2.49 (95 percent confidence interval, 1.50 to 4.13). A low intake of fiber from fruits appeared to contribute to the risk of colon cancer, but this relation was not statistically independent of meat intake. CONCLUSIONS: These prospective data provide evidence for the hypothesis that a high intake of animal fat increases the risk of colon cancer, and they support existing recommendations to substitute fish and chicken for meats high in fat.

Adult↗

A comparison of two automated monitors in the measurement of blood pressure reactivity. Trials of Hypertension Prevention Collaborative Research Group.

Cardiovascular reactivity is the change in blood pressure, pulse, and other parameters of cardiovascular function in response to a challenging task. During the conduct of cardiovascular reactivity protocols, researchers frequently use automated blood pressure devices to measure blood pressure reactivity. However, the accuracy of automated devices in measuring blood pressure reactivity is unknown. To investigate the accuracy and precision of the Dinamap 1846 SXP and the VitaStat 2600B in the measurement of blood pressure reactivity, we compared blood pressure reactivity recorded by the VitaStat and Dinamap with that obtained by observers using a conventional mercury sphygmomanometer. At three sites, 159 normotensive subjects performed the same task twice, once with blood pressure reactivity measured by the manual observers and once by the VitaStat (n = 79) or Dinamap (n = 80), with the order determined at random. Ratios (VitaStat/Dinamap) of aggregate within-person variance for baseline and task, systolic and diastolic blood pressures ranged from 1.53 to 4.93 (all P < 0.01), suggesting that the Dinamap has better precision than the VitaStat. For both diastolic and systolic blood pressure reactivity and for both types of automated devices, the mean differences in blood pressure reactivity between manual and automated measurements were small (range, -1.8 to 0.8 mm Hg). However, the VitaStat versus manual scatter plot of diastolic blood pressure reactivity showed greater dispersion (correlation coefficient r = 0.16, P = 0.15) than the Dinamap versus manual scatter plot (r = 0.36, P = 0.001). For systolic blood pressure reactivity, the VitaStat versus manual and Dinamap versus manual scatter plots were similar. Our data indicate that the Dinamap is superior to the VitaStat in the measurement of blood pressure reactivity. The substantial performance differences between the VitaStat and Dinamap suggest that other automated blood pressure monitors must be evaluated prior to use in cardiovascular reactivity studies.

Adult↗

Otitis media in infancy and intellectual ability, school achievement, speech, and language at age 7 years. Greater Boston Otitis Media Study Group.

To determine intellectual and linguistic sequelae of middle ear disease, 207 children were randomly selected from a cohort of 498 followed prospectively from birth until age 7 years. After controlling for confounding variables, estimated time spent with middle ear effusion (MEE) during the first 3 years of life was significantly associated with lower scores on tests of cognitive ability, speech and language, and school performance at age 7 years. The adjusted mean full-scale WISC-R were 113.1 for those with least time with MEE, 107.5 for those with moderate time, and 105.4 for those with most time. Similar significant differences were found for verbal and performance IQ scores. For the Metropolitan Achievement Test, we found that middle ear disease in the first 3 years of life was associated with significantly lower scores in mathematics and reading. Similar differences were found for articulation and use of morphologic markers. After considering time spent with MEE during the first 3 years of life, time spent after age 3 years was not a significant predictor of scores on any of the tests administered.

Child↗

Lactation and risk of breast cancer in a cohort of US women.

The relation between lactation and risk of breast cancer was examined in a cohort of 89,413 parous female US registered nurses aged 30-55 years and free from cancer in 1976 who provided information on total duration of lactation in 1986. Between 1976 and 1986, 1,262 cases of breast cancer occurred during 785,958 person-years of follow-up. There was no independent association between lactation and the risk of breast cancer. After adjustment for age and parity, compared with women who had never lactated, the relative risks (and 95% confidence intervals (CI] were 0.95 (95% CI 0.84-1.08) for women with less than 7 months of lactation, 0.87 (95% CI 0.71-1.08) for 7-11 months, 0.94 (95% CI 0.77-1.14) for 12-23 months, and 0.98 (95% CI 0.76-1.28) for greater than or equal to 24 months (test for trend: z = -0.80, p = 0.42). The association did not differ by age or menopausal status. These results do not confirm reports that relatively short durations of lactation reduce the risk of breast cancer among younger women.

Adult↗

Prospective study of smoking and the risk of breast cancer.

In 1976, 117,557 women in the United States aged 30-55 years and without a history of cancer provided detailed information on current smoking habits. By 1986, 1,788 cases of breast cancer had been documented during 1,133,682 person-years. There was no association between current smoking and risk of breast cancer (multivariate-adjusted relative risk for smokers of greater than or equal to 25 cigarettes/day compared to nonsmokers: 1.02, 95% confidence interval, 0.96-1.22). Past smoking also was unrelated to breast cancer risk (relative risk, 1.08; 95% confidence interval, 0.96-1.20). The results did not differ by menopausal status. Tumor size and the presence of nodal metastases were unrelated to smoking. Smoking was weakly associated with estrogen receptor-positive tumors (relative risk for smokers of greater than or equal to 25 cigarettes/day compared with never smokers, 1.38; 95% confidence interval, 1.04-1.84), but there was no dose-response relationship across categories of current smoking. These results suggest that smoking and breast cancer are not materially related.

Adult↗

Moderate alcohol consumption and the risk of breast cancer.

In 1980, 89,538 U.S. women 34 to 59 years of age, with no history of cancer, completed an independently validated dietary questionnaire that included the use of beer, wine, and liquor. During the ensuring four years, 601 cases of breast cancer were diagnosed among cohort members. Among the women consuming 5 to 14 g of alcohol daily (about three to nine drinks per week), the age-adjusted relative risk of breast cancer was 1.3 (95 percent confidence limits, 1.1 and 1.7). Consumption of 15 g of alcohol or more per day was associated with a relative risk of 1.6 (95 percent confidence limits, 1.3 and 2.0; Mantel extension chi for linear trend = +4.2; P less than 0.0001). Adjustment for known breast cancer risk factors and a variety of nutritional variables did not materially alter this relation. Significant associations were observed for beer and liquor when considered separately. Among women without risk factors for breast cancer who were under 55 years of age, the relative risk associated with consumption of 15 g of alcohol or more per day was 2.5 (95 percent confidence limits, 1.5 and 4.2). These prospective data derived from measurements of alcohol intake recorded before the diagnosis of breast cancer confirm the findings of several previous case-control studies. Viewed collectively, they suggest that alcohol intake may contribute to the risk of breast cancer.

Adult↗

Dietary fat and the risk of breast cancer.

Dietary fat has been suggested as a risk factor for breast cancer in women, but the available data on humans are sparse and inconsistent. In 1980, 89,538 U.S. registered nurses who were 34 to 59 years of age and had no history of cancer completed a previously validated dietary questionnaire designed to measure individual consumption of total fat, saturated fat, linoleic acid, and cholesterol, as well as other nutrients. In a subsample of 173 participants studied in detail, those in the highest quintile of fat intake consumed a mean of 44 percent of calories from fat, as compared with 32 percent for those in the lowest quintile. During four years of follow-up, 601 cases of breast cancer were diagnosed among the 89,538 nurses in the study. After adjustment for known determinants in multivariate analyses, the relative risk of breast cancer among women in the highest quintile of calorie-adjusted total fat intake, as compared with women in the lowest quintile, was 0.82 (95 percent confidence limits, 0.64 and 1.05). The corresponding relative risks were 0.84 (confidence limits, 0.66 and 1.08) for saturated fat, 0.88 (0.69 and 1.12) for linoleic acid, and 0.91 (0.70 and 1.18) for cholesterol intake. Similar results were found for both postmenopausal and premenopausal women. These data are based on a limited period of follow-up and do not exclude a possible influence of fat intake before adulthood or at levels lower than 30 percent of calories. They suggest, however, that a moderate reduction in fat intake by adult women is unlikely to result in a substantial reduction in the incidence of breast cancer.

Adult↗

Enhanced proliferation of WI38 cells in the presence of glucocorticoid-conditioned medium.

The addition of hydrocortisone (HC) or dexamethasone (DEX) to WI38 cells at subcultivation is known to result in increased saturation densities (20-40%). We report that maximal increases in saturation density are, however, only observed if HC is added to the culture shortly after subcultivation. We have found that the proliferative response of WI38 cells to glucocorticoids is mediated by a secondary stimulatory factor(s) present in medium-conditioned by cells in the presence of the hormone. Control cultures refed with medium conditioned in the presence of HC for the first 24 h after seeding (24 h HC-CM) achieve saturation densities 20-40% higher than cultures refed with either medium conditioned in the absence of the hormone (24 h CM) or 24 h CM supplemented with fresh HC. Furthermore, WI38 cultures remain responsive to the stimulatory activity present in 24 h HC-CM throughout the growth cycle. The stimulatory effects of 24 h HC-CM are enhanced by repeatedly refeeding cultures; WI38 cells refed every 2 days with 24 h HC-CM demonstrate an extended period of logarithmic growth and achieve densities 2-3 times higher than controls. A preliminary characterization of this activity shows it to be of low molecular weight (MW) (dialyzable using 12 000 MW cut-off tubing) and heat-stable (75 degrees C).

Cell Division↗

Otitis media with effusion during the first three years of life and development of speech and language.

To determine the association between time spent with middle ear effusion and development of speech and language, 205 three-year-old children were studied. Each child had been followed prospectively from birth to record the number of episodes of middle ear disease and to document time spent with middle ear effusion. Standardized tests of speech and language were administered at age 3 years to children who had spent much time with middle ear effusion and to children who had spent little or no time with middle ear effusion. Children who had spent prolonged periods of time with middle ear effusion had significantly lower scores when compared with those who had spent little time with middle ear disease. The correlation was strongest in children from higher socioeconomic strata. Time spent with middle ear effusion in the first 6 to 12 months of life was most strongly associated with poor scores.

Acute Disease↗

Changes in specific dexamethasone binding during aging in WI-38 cells.

Normal human diploid cell line WI-38, which shows enhanced proliferation in the presence of glucocorticoids, was found to contain high affinity binding sites for dexamethasone (DEX) and hydrocortisone. Hormone binding studies carried out in intact cell monolayers showed rapid uptake and binding of the [3H]DEX, which was independent of cell density at 37 C. The number of binding sites per cell decreased with increased age in vitro. Competition studies with several unlabeled steroids demonstrated high molecular specificity and a strong correlation between the ability of a steroid to compete for specific DEX binding sites and its ability to stimulate cell proliferation. Our observation that the number of specific glucocorticoid binding sites per cell decreased 40% without any significant change in affinity is similar to observations made in target tissues in aged animals. This finding may explain the previously reported decrease in responsiveness to these glucocorticoids in aging WI-38 cells.

Biological Transport↗

Hydrocortisone: a specific modulator of in vitro cell proliferation and aging.

The effects of hydrocortisone on the proliferative activity of various vertebrate fibroblast-like cell lines have been measured. The proliferative activity of human fetal lung-derived cell lines, such as WI-38, and those of human fetal foreskin origin were always enhanced by the hormone. The addition of hydrocortisone to a number of other vertebrate cell lines grown under identical conditions showed growth inhibition. We also determined that the stimulation of WI-38 cell growth by hydrocortisone was a specific steroid-cell interaction by testing the growth promoting activity of several steroids with molecular structures similar to that of hydrocortisone. This observation was further supported by the presence of high effinity glucocorticoid binding sites in WI-38 cells whose concentration per cell was found to decrease with increased in vitro age. The results suggest that the proliferative response to hydrocortisone shows a cell-type specificity as well as a steroid-molecular structure specificity. The response appears to be mediated by high affinity glucocorticoid binding sites.

Cell Division↗

Adverse effects of nosocomial infection.

The effects of noscomial infection on duration of hospital stay and outcome of hospitalization were measured by matching two control patients to each of 85 patients found to have qctive nosocomial infection during a prevalence survey at Boston City Hospital in 1973. The control patients were selected from all patients discharged from this hospital during the same time period; they were matched by exact primary discharge diagnosis, similar operative procedure, and age. Patients with a single infection remained in hospital on average 13.0 days longer than their matched controls, and those with two such infections stayed on average 35.4 days longer. This effect of extra stay associated with nosocomial infection was consistent when data were stratified by primary discharge diagnosis, hospital service, site of infection, or outcome of hospitalization. The outcome of hospitalization for these infected patients was slightly, but not significantly, worse than for their matched controls.

Boston↗

Modulation of cell proliferation and senescence of WI-38 cells by hydrocortisone.

The specific binding of glucocorticoid hormones has been studied in the normal diploid human cell line WI-38. These cells were found to contain high affinity glucocorticoid binding sites whose molecular specificity showed a high correlation to that required for the stimulation of cell growth. When hydrocortisone (HC) was selectively added to or removed from parasynchronously dividing cultures, we observed that HC -enhanced stimulation of cell growth was associated with the hormone's presence in the pre-DNA synthetic period of the cell cycle. Similarly, the specific binding of [3H]dexamethasone in stimulated quiescent cells was found to increase significantly in the pre-DNA synthetic period. The concentration of specific binding sites per cell achieved in stimulated cell cultures was found to decrease with increasing in vitro age. These results suggest that the stimulation of WI-38 cell proliferation by HC involves specific glucocorticoid receptors whose concentration per cell is under cell cycle control. The age-associated decrease in specific glucocorticoid binding sites may explain, in part, our previously observed loss of responsiveness to HC in aging cell cultures.

Cell Cycle↗

Stereospecificity of the hydrogen transfer catalyzed by human placental aldose reductase.

Placental aldose reductase (EC 1.1.1.21) was incubated with glucose in the presence of [4A-2H] NADPH prepared in the oxidation of [2-2H] isocitrate by isocitrate dehydrogenase (EC 1.1.1.42) or [4B-2H] NADPH prepared in the oxidation of [1-2H] glucose-6-phosphate dehydrogenase (EC 1.1.1.49). The sorbitol formed from [4A-2H] NADPH contained deuterium and from [4B-2H] NADPH it did not. Therefore, aldose reductase in an A-type enzyme.

Alcohol Oxidoreductases↗

Epidemiology of otitis media in children.

To determine the epidemiology of otitis media (OM) during the first three years of life, physicians participating in the Greater Boston Collaborative Otitis Media Program followed prospectively from birth 2,565 children. At every visit we recorded results of pneumatic otoscopy and epidemiology data. By three years of age 71% of the children had had one or more episodes of acute otitis media including 33% who had three or more episodes. Features associated significantly with first episode of OM were: sibling with recurrent OM, race (white > black), and sex (male > female). Having a sibling with allergy disposed propositi to first episode. Features associated significantly with recurrent OM (greater than or equal to three episodes) were those noted above. A parent with recurrent OM disposed propositi to recurrent OM. Middle ear effusion (MEE) persisted for prolonged periods after OM; after the first episode of OM, 70% of children still had MEE at two weeks, 40% had fluid at one month, 20% had fluid at two months, and 10% had fluid at three months. The sole feature associated significantly with persistent effusion in the middle ear after the first episode of OM was the practice of giving a child a bottle in bed.

Boston↗