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L Sampson

Publications and source records attributed to L Sampson.

At least 37 records · Page 2Linked to original sources
PubMed1988

Energy intake and other determinants of relative weight.

The relationships of relative weight to energy intake and to physical activity were studied among 141 females aged 34-59 y. As observed in previous studies Quetelet index (wt/ht2) was inversely related to energy intake (r = -0.11). However, obese women tended to be older (r = 0.16), exercise less (r = -0.30), and drink less alcohol (r = -0.16) than nonobese women. Older women had lower energy intake (r = -0.23) and exercised less (r = -0.12) than younger women. Energy intake and physical activity were positively related (r = 0.23). After adjustment for age, physical activity, alcohol, and smoking, the inverse correlation between relative weight and energy intake was significantly reduced (p = 0.04) from r = -0.11 to r = -0.02. Obese women reported higher intakes of total fat, and relative weight was significantly correlated with intakes of total fat (r = 0.20) and saturated fatty acids (r = 0.16). These data highlight the importance of considering factors that may confound the relationship between energy intake and obesity, and they suggest that fat intake may play a role in obesity that is independent of total energy intake.

Adult↗
PubMed1988

The use of a self-administered questionnaire to assess diet four years in the past.

The use of a mailed, self-administered, semiquantitative food frequency questionnaire to describe past dietary intake was evaluated in 1984 among a group of 150 Boston-area women who had completed four one-week diet records three to four years previously. Correlation coefficients comparing calorie-adjusted nutrient intakes computed from the questionnaire with those obtained from a compressed version of the questionnaire completed during diet record keeping ranged from 0.44 for total carbohydrate to 0.62 for vitamin C including supplements. Coefficients comparing calorie-adjusted nutrient intakes measured by questionnaire with those assessed by the diet records completed three to four years previously ranged from 0.28 for iron without supplements to 0.61 for total carbohydrate. An evaluation of the incremental contribution provided by several open-ended sections of the questionnaire to the estimation of nutrient intake suggested that in this population most of these items might be eliminated without material loss of information. These findings demonstrate that useful estimates of nutrient intake several years previously can be obtained by a relatively inexpensive, mailed, self-administered questionnaire.

Adult↗
PubMed1988

Variability in portion sizes of commonly consumed foods among a population of women in the United States.

The use of food frequency questionnaires for measuring dietary intake has become widespread in epidemiologic studies. It has been suggested that inquiring about a person's usual serving size of each food, in addition to the frequency of consumption, will improve the accuracy of this method. This approach implies that individuals characteristically eat a specific amount of any particular food, and that this amount can be reported with reasonable accuracy. To investigate the variability of portion sizes, the authors analyzed data for 68 commonly consumed foods, based on four one-week weighed diet histories recorded by 194 Boston-area women aged 34-59 years during 1980 and 1981. For each food, total population variance in portion size was partitioned into within-person (intraindividual) and between-person (interindividual) components. For all but seven food items (yogurt, liver, mixed vegetables, watermelon, pancakes/waffles, cold cereal, and cooked cereal) the within-person variance in portion size exceeded the between-person variance. The mean of the within-person to between-person variance ratios, after exclusion of two outlying foods, was 3.4 for untransformed portion sizes, and 3.2 after portion sizes were loge-transformed. Foods with a high within-person variance also tended to have a high between-person variance. The dominance of within-person variance in portion sizes suggests that the concept of usual portion size is complex, and that subjects may experience substantial difficulty in specifying their "usual" portion size. The smaller contribution of between-person variance to the total variance in portion size suggests that specification of a standard portion size by the investigator may not introduce a large error in the estimation of food and nutrient intake.

Adult↗
PubMed1987

The influence of age, relative weight, smoking, and alcohol intake on the reproducibility of a dietary questionnaire.

To evaluate factors that affect the reproducibility of a semi-quantitative food frequency questionnaire used in a large prospective study we compared an extended 99-item questionnaire with a shorter, 61-item form completed by 1497 women with an interval of nine months between. Correlation coefficients for individual items assessed by the two questionnaires were highest for beverages (Spearman r = 0.70). For other foods, coefficients ranged from 0.60 to 0.70 for items eaten frequently (or habitually), to values between 0.34 and 0.45 for foods, such as sweet potatoes and ready made pie, that were eaten less frequently. For food items, the correlation between mean frequency of consumption and the reproducibility coefficient (Spearman r) was 0.51 (p less than 0.01), formally confirming that the reproducibility of measurements was positively associated with frequency of use. Pearson correlation coefficients for calorie-adjusted intakes of nutrients between the two questionnaires ranged from 0.40 for trans-fatty acids to 0.71 for vitamin E (including supplements). These correlation coefficients did not vary materially between subjects in different categories of smoking status or tertiles of age or relative weight. Moderate alcohol use had minimal effect on correlation coefficients, but reproducibility was slightly reduced among heavier drinkers. These data indicate that this self-administered dietary questionnaire can provide reproducible information about individual food and nutrient intakes which is not altered materially by age and a number of important health habits.

Adult↗
PubMed1987

Rocky IV.

Explore the source record for details and available documents.

Athletic Injuries↗
PubMed1987

Validation of a semi-quantitative food frequency questionnaire: comparison with a 1-year diet record.

The validity of a self-administered semi-quantitative food frequency questionnaire was evaluated for a group of 27 men and women aged 20 to 54. Intakes of 18 nutrients computed from the questionnaire were compared with those derived from 1-year diet records completed approximately 18 months earlier. The questionnaire estimates of mean nutrient intake were within 10% of the mean diet record measurements for 11 of the 18 nutrients evaluated, and the difference was less than 25% for all but one nutrient (total vitamin A). Correlation coefficients comparing unadjusted nutrient intakes measured by the two methods ranged from 0.38 (vitamin C) to more than 0.65 (total calories, total fat, saturated fat, polyunsaturated fat, oleic acid, and cholesterol). The overall mean of correlation coefficients comparing intakes of the 18 nutrients measured by questionnaire and by diet record was 0.60. Coefficients for macronutrients decreased somewhat after adjustment for age and gender or caloric intake. The data provide further evidence that a simple and relatively inexpensive questionnaire can provide useful information on dietary intake over an extended period.

Adult↗
PubMed1986

Plasmid vectors useful in the study of translation initiation signals.

The construction and characterization of plasmid vectors useful in the analysis of translation initiation signals in Escherichia coli and in the construction of lacZ gene hybrids are described. Transcription on the vectors proceeds from a cAMP-independent lac promoter through several restriction sites into a truncated lacZ structural gene lacking its first eight codons. Because this gene has no translation initiation signal, its level of expression is extremely low. A DNA fragment containing a translation start signal can be inserted between the promoter and truncated lacZ gene to produce a hybrid protein with functional beta-galactosidase activity. The vectors described here differ in sequence between the EcoRI cloning site and the lacZ gene to allow easy, in-frame joining of DNA containing a translation initiation signal to the lacZ gene. Cells containing plasmids can be screened directly for in-frame inserts by colony color on indicator plates.

Genetic Vectors↗
PubMed1986

Validation of questionnaire information on risk factors and disease outcomes in a prospective cohort study of women.

To assess the validity of self-reported illnesses, medical records were reviewed for participants reporting major illnesses on the biennial follow-up questionnaires used in a prospective cohort study which began in 1976. In over 90% of cases of cancer of the breast, skin, large bowel, and thyroid, histopathology reports confirmed the subjects' self-report. Lower levels of confirmation were obtained for cancers of the lung, ovary, and uterus. Application of strict diagnostic criteria also gave lower levels of confirmation for myocardial infarction (68%) and stroke (66%). Among random samples of women reporting fractures and hypertension all records obtained confirmed self-reports. For self-reported elevated cholesterol levels 85.7% of self-reports were confirmed. Self-report is a valuable epidemiologic tool but may require additional documentation when the disease is diagnostically complex.

Adult↗
PubMed1985

Reproducibility and validity of a semiquantitative food frequency questionnaire.

The aim of this study was to evaluate the reproducibility and validity of a 61-item semiquantitative food frequency questionnaire used in a large prospective study among women. This form was administered twice to 173 participants at an interval of approximately one year (1980-1981), and four one-week diet records for each subject were collected during that period. Intraclass correlation coefficients for nutrient intakes estimated by the one-week diet records (range = 0.41 for total vitamin A without supplements to 0.79 for vitamin B6 with supplements) were similar to those computed from the questionnaire (range = 0.49 for total vitamin A without supplements to 0.71 for sucrose), indicating that these methods were generally comparable with respect to reproducibility. With the exception of sucrose and total carbohydrate, nutrient intakes from the diet records tended to correlate more strongly with those computed from the questionnaire after adjustment for total caloric intake. Correlation coefficients between the mean calorie-adjusted intakes from the four one-week diet records and those from the questionnaire completed after the diet records ranged from 0.36 for vitamin A without supplements to 0.75 for vitamin C with supplements. Overall, 48% of subjects in the lowest quintile of calorie-adjusted intake computed from the diet records were also in the lowest questionnaire quintile, and 74% were in the lowest one of two questionnaire quintiles. Similarly, 49% of those in the highest diet record quintile were also in the highest questionnaire quintile, and 77% were in the highest one or two questionnaire quintiles. These data indicate that a simple self-administered dietary questionnaire can provide useful information about individual nutrient intakes over a one-year period.

Adult↗
PubMed1981

Vitamin supplement use among registered nurses.

A dietary questionnaire which included items relating to the use of specific vitamin preparations was sent to a randomly selected group of 2000 female, registered nurses aged 30 to 59 yr residing in 10 states. Among the 1742 women (87%) who returned completed questionnaires, the rates of use were 38% for multiple vitamins, 4% for specific preparations of vitamin A, 23% for vitamin C, and 15% for vitamin E. Women who used specific preparations of vitamins A, C, and E generally consumed them in quantities many times greater than the RDA. Use of specific vitamin preparations was found to increase with age and was highest in California.

Adult↗
PubMed1981

The association of goitrous autoimmune thyroiditis with HLA-DR5.

We found HLA-DR5 to be present among 53% of 40 patients with goitrous autoimmune (Hashimoto's ) thyroiditis compared to 26% of 80 controls. No deviations from those expected in the incidences of HLA-A, B, C antigens were seen. In contrast HLA-DR3 was increased among 50 patients with atrophic thyroiditis (65%) compared to controls (24%). These findings stress the immunogenetic heterogeneity between the goitrous and atrophic varieties of thyroiditis.

Antibody Formation↗
PubMed1980

Polyglandular autoimmune disease and HLA.

We have studied 25 patients with polyglandular autoimmune disease with respect to HLA antigens. Whereas the combination of insulin dependent diabetes with Graves' disease or atrophic thyroiditis was associated with an increase in HLA-B8, this was not found to be the case for patients with I.D.D.M. and goitrous thyroiditis. However 4/7 of these patients were DRw3 positive in contrast to previously established normal distribution of HLA-B8 in patients with goitrous thyroiditis alone. These data suggest that patients with polyglandular failure may be highly selected for HLA-B8/DRw3 positivity. We also report on two families with polyglandular autoimmune disease; the results suggest that these disorders are not necessarily transmitted with B8/DRw3 bearing haplotypes. In one family both the affected mother and non-affected father were B8 positive. The mother's B8, which was associated with DRw7, BfF and Rga did not appear to be involved in the transmission of disease susceptibility to two affected offspring. The search for complete haplotypic arrangement should be pursued to see whether this uncommon haplotype arrangement is peculiar to autoimmune diseases.

Adult↗
PubMed1979

A study of human leukocyte D locus related antigens in Graves' disease.

An association between Graves' disease and the human leukocyte antigen (HLA) system has previously been reported. The disease was more strongly associated with the HLA D locus antigen Dw3 than with HLA B8. Products of the HLA D locus are determined by the interaction of test cells with standard typing lymphocytes, a technically difficult procedure. Recently, it has been possible to type serologically for D locus related (DRw) specificities on peripheral bone marrow-derived (B) lymphocytes. Blood B lymphocytes from 50 unrelated controls and 41 patients with Graves' disease were typed for seven HLA DRw specificities. 28 patients with Graves' disease (68%) were positive for DRw3, in contrast to 14 controls (28%); whereas only 21 patients (50%) were HLA B8 positive, compared with 13 (26%) controls. Thus, positivity for DRw3 afforded a relative risk for Graves' disease of 5.5, whereas that for HLA B8 amounted to 3.0. Additionally, a family with multiple cases of Graves' disease in which the disease was previously shown to be inherited with the haplotype, was linked to DRw2, which suggests that the susceptibility to the disease was inherited in association with that antigen. Two HLA B/glyoxalase recombination events were observed in this family; in both instances HLA DRw followed HLA B. This study thus demonstrates that the disease susceptibility gene for Graves' disease is in strong linkage disequilibrium with DRw3; however, it may be associated with other DRw specificities and inherited within family units in association with them.

Alleles↗
PubMed1979

HLA-D--related (DRw) antigens in juvenile diabetes mellitus.

We studied the distribution of HLA-D--related (DRw) antigens in 40 patients with juvenile diabetes mellitus (JDM) and 79 matched controls. We found that DRw2 was significantly decreased in the JDM group, suggesting a protective effect of the antigen and that the decrease observed in B7 was secondary. HLA-DRw3 and HLA-DRw4 were increased in the diabetic group, and, as with B8/B15, these two antigen predisposed to the disease additively. The susceptibility for JDM was found to be more strongly related to HLA-DRw3 that to B8. On the other hand, B15 rather than DRw4 showed the stronger association with JDM. Moreover, we found that this second diabetogenic gene is associated primarily with B15 and only secondarily with Cw3, which is in linkage disequilibrium with B15. This study further emphasizes the immunogenetic heterogeneity of JDM.

Diabetes Mellitus, Type 1↗