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Biomedical subjects

G Block

Publications and source records attributed to G Block.

At least 127 records · Page 7Linked to original sources
PubMed1987

Dietary fat and breast cancer in the National Health and Nutrition Examination Survey I Epidemiologic Follow-up Study.

The relationship between dietary fat intake and breast cancer incidence was examined in the National Health and Nutrition Examination Survey I (NHANES I) Epidemiologic Follow-up Study cohort. This cohort is derived from adults (greater than or equal to 25 yr) examined in the NHANES I (1970-75) cross-sectional survey of the U.S. population and provides a mean follow-up time of 10 years. An analytic sample of 5,485 women, including 99 breast cancer cases (34 premenopausal and 65 postmenopausal at NHANES I baseline), was examined for associations with dietary intake of fat, percent energy from fat, total energy, saturated fat, polyunsaturated fat, monounsaturated fat, and cholesterol on the basis of a 24-hour recall administered at the baseline NHANES I examination. No significant differences in dietary fat intake between cases and noncases were evident when mean intakes for each group were compared. For total fat (g) and saturated fat (g), a significant inverse association was indicated in proportional hazards analyses. Adjustment of fat for total energy intake resulted in a smaller effect that was no longer statistically significant. Adjustment for accepted breast cancer risk factors did not change these findings. This prospective study of a sample from the U.S. population does not support the hypothesis that high dietary fat intake increases breast cancer risk. Indeed, some lower risk associated with high fat intake may be indicated, although this result may be influenced by methodologic problems with the dietary assessment.

Adult↗
PubMed1986

A data-based approach to diet questionnaire design and testing.

A self-administered diet history questionnaire has been developed for epidemiologic and clinical use. Both the food list and the nutrient values to be associated with it were developed using dietary data from 11,658 adult respondents to the Second National Health and Nutrition Examination Survey (NHANES II). Food items were selected on the basis of their contribution to total population intake of energy and each of 17 nutrients in the NHANES II data, and represent over 90% of each of those nutrients. Associated nutrient composition values were determined from the NHANES II database using frequency of consumption data in that survey. Portion sizes to be associated with each food item were derived from observed portion size distributions in NHANES II, based on three-dimensional models. The resulting food list and its corresponding brief data base, when used to calculate nutrients from a diet record, yielded correlations of r greater than 0.70 with the more detailed method. Field administration produced mean values comparable to national data.

Adult↗
PubMed1986

Locus of control and smokeless tobacco use among adolescents.

Seventh-grade students from two school districts in rural North Carolina were surveyed to determine the prevalence and correlates of smokeless tobacco use. The survey was carried out as part of a larger project intended to study prevalence of "risky" behaviors, specifically alcohol and tobacco use. Data were collected from 322 students: 49% male, 36.6% nonwhite. Of those reporting use of smokeless tobacco (11.4%), virtually all were male; most reported weekly use, with a small proportion (1.3%) reporting daily use. Locus of control of "occasional" users was significantly more internal than those reporting "regular" use (p less than .05).

Adolescent↗
PubMed1985

Nutrient sources in the American diet: quantitative data from the NHANES II survey. I. Vitamins and minerals.

Dietary data from 11,658 adult respondents in the second National Health and Nutrition Examination Survey were used to provide quantitative information regarding the contribution of specific foods to the total population intake of the following 10 nutrients: vitamin A, thiamine, riboflavin, niacin, vitamin C, iron, phosphorus, calcium, sodium, and potassium. Data are reported in the companion paper regarding the number of adults in the US population consuming each of 147 food items, representing all foods reported by these respondents. The percentage of total nutrient intake which each food provides is presented for the top 50 contributors of each of the nutrients listed above. Foods sometimes overlooked as important sources are found in some instances to be quantitatively important to population intake, such as spaghetti dishes as an independent source of carotenoids. These data should be useful to epidemiologists with a substantive interest in dietary etiologies or a methodological interest in the development of dietary assessment instruments. In addition, they may be useful to health care planners or nutrition educators.

Adult↗
PubMed1985

Nutrient sources in the American diet: quantitative data from the NHANES II survey. II. Macronutrients and fats.

Dietary data from 11,658 adult respondents in the second National Health and Nutrition Examination Survey were used to provide quantitative information regarding the contribution of specific foods to the total population intake of the following nutrients: calories, protein, carbohydrate, total fat, saturated fat, oleic acid, linoleic acid, and cholesterol. The percentage of total nutrient intake which each food provides is presented for the top 50 contributors of each of these nutrients, as well as the proportion of the population consuming them. These data may provide a basis for the selection of foods to be included in dietary assessment instruments. They may also be useful to health care planners or nutrition educators.

Adult↗
PubMed1984

Baker's asthma. Studies of the cross-antigenicity between different cereal grains.

Specific IgE antibodies were demonstrated in the sera of six bakers with respiratory symptoms of asthma or bronchitis by the radioallergosorbent (RAST) assay. The specificity of the antibodies was found to be directed not only against the common flours (rye, wheat) used in the bakeries but also against triticale, barley, oat, corn and rice in some of the bakers. By using the RAST inhibition tests, cross-antigenicity was shown to exist between different cereal grains. The degree of cross-reactivity closely paralleled their taxonomic relationship and appeared to be in the following order of decreasing closeness: wheat, triticale, rye, barley, oat, rice and corn. The allergenic activity in the rye and wheat extracts was found to be distributed among various fractions of different molecular weights.

Antibodies, Anti-Idiotypic↗
PubMed1983

A method for estimating year of birth using social security number.

A method for estimating year of birth using only Social Security number is described. The method relies on estimating the year of issue of the Social Security number, using either precise information from a Social Security Administration table (for numbers issued since 1950) or extrapolation (for numbers issued before 1951). Age at issue was estimated using data from individuals in an occupationally defined population for whom both birth date and Social Security number were known. Year of birth is then year of issue minus age at issue. A highly statistically significant correlation of 0.91 for known vs. estimated year of birth was observed. Predictions correct within +/- 5 years were achieved for 78 per cent of the entire study population. For individuals born after approximately 1934, predictions within +/- 5 years of the correct year were achieved 95 per cent of the time, and within +/- 2 years 77 per cent of the time. The method may be useful in epidemiologic research in situations in which date of birth is missing. Some applications are discussed.

Adolescent↗
PubMed1983

Baker's asthma. Clinical and immunological studies.

Seven bakers with respiratory symptoms were evaluated by skin tests, RAST assay for specific IgE antibodies to rye and wheat, inhalation challenge with methacholine for the determination of non-specific bronchial reactivity, and bronchoprovocation with rye and wheat extracts for the determination of antigen-specific bronchial reactivity. An immediate asthmatic response to antigen challenge was observed in four subjects and all of them had a high level of flour-specific IgE antibodies. The serum RAST values provided a more accurate predictive value than the degree of cutaneous sensitivity determined by skin testing with respect to the bronchial response to antigenic challenge. Among those who reacted positively to antigenic bronchoprovocation, a much lower antigen dose was required to elicit a positive reaction if the subject also had an increased degree of non-specific bronchial reactivity. An elevated RAST value was not found in thirty-eight asymptomatic bakers or in ten asthmatics who had no occupational exposure to flour. Thus, baker's asthma appears to be a form of allergic asthma to cereal flours mediated by specific IgE antibodies. Both the level of serum IgE antibodies and the degree of non-specific bronchial reactivity are important factors which may influence a baker's bronchial response upon inhalation of cereal flours.

Adult↗
PubMedDate not supplied

Insulin-like growth factor-1 and growth hormone (GH) levels in canine cerebrospinal fluid are unaffected by GH or GH secretagogue (MK-0677) administration.

Elevation in circulating GH levels results in a dose-related increase in serum insulin-like growth factor-1 (IGF-1) levels in dogs. However, it is not known whether elevations in systemic IGF-1 and GH levels contribute to the cerebrospinal fluid (CSF) levels of these hormones. Therefore, a study was designed in dogs to determine if elevated circulating GH levels was a result of a GH secretagogue (MK-0677) or if exogenous GH administration resulted in increased IGF-1 and GH levels in the CSF of dogs. A total of 12 normal, young adult male dogs were randomized to three treatment groups (4 dogs/group) based on body weight. There were 4 vehicle control dogs. A group of 4 dogs were dosed orally with MK-0677 (5 mg/kg/day) dissolved in deionized water. A third group of 4 dogs received subcutaneous injections of porcine GH (pGH) at a dose of 0.1 IU/kg/day. From all dogs, blood and CSF samples were collected prior to the initiation of treatment and on days 7 and 15 of treatment. All samples were assayed using a validated radioimmunoassay. Administration of MK-0677 or pGH resulted in a statistically significant (P < or = 0.05) increased body weight gain and increased serum IGF-1 and GH levels. In contrast, administration of MK-0677 resulted in no significant (P > 0.05) increase in CSF IGF-1 or GH levels on days 7 or 15 of the study. The CSF IGF-1 values ranged from 1.2 to 2.0 ng/ml with minimal variation among three separate samples taken during the course of the study from each dog. Similarly, the CSF GH levels were very low (< 0.98 ng/ml to 2.4 ng/ml) in all dogs irrespective of treatment group. This study has demonstrated that there is no correlation between the circulating levels of IGF-1 or GH and the levels of these hormones in the CSF of normal dogs. An approximately 100-fold difference between serum and CSF IGF-1 levels in vehicle control dogs suggest that there is a blood-brain barrier for the circulating IGF-1. Similarly, failure to see an elevation in CSF GH levels despite increases in serum GH levels shows that there is a blood-brain barrier for GH in normal dogs. These results suggest that the likely source of GH and IGF-1 in the CSF of dogs is from the CNS.

Animals↗
PubMedDate not supplied

Respiratory health at a pulpmill in British Columbia.

The respiratory parameters of 392 white male pulpmill workers were measured by standardized procedures and compared with those of 310 white male rail yard workers. The pulpmill workers complained more frequently of wheezing and chest tightness and missed work more commonly because of chest illness as compared with the rail yard workers. Significant airflow obstruction was noted in nonsmokers who worked in the bleach plant, and it was most striking in the younger members of this group. The principal environmental contaminant in this area was chlorine at levels generally below current permissible concentrations. Members of the maintenance group--especially older members--demonstrated significantly lower forced vital capacity compared to the rail yard workers.

Absenteeism↗