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Biomedical subjects

G Block

Publications and source records attributed to G Block.

At least 73 records · Page 4Linked to original sources
PubMed1991

An open multicenter trial of Sinemet CR in levodopa-naive Parkinson's disease patients.

It has been proposed that initiation of anti-Parkinson therapy with continuous release formulations of Sinemet might prevent or delay the development of adverse effects associated with chronic levodopa therapy employed in standard formulations. In anticipation of a prospective study comparing Sinemet to Sinemet CR in previously untreated Parkinson's disease patients, we evaluated Sinemet CR as primary therapy in 45 levodopa-naive Parkinson's disease patients in a 12 week, open-label, multi-center study. At the conclusion of the study, optimal results were obtained with levodopa administered as Sinemet CR in a total daily dose of 497 mg divided into 2.4 doses per day. Statistically significant improvement compared to baseline was observed for total Parkinson's score as well as each of rigidity, tremor, bradykinesia, gait and postural stability. Statistically significant improvement was also noted in total disability as well as in each of its components. Adverse experiences were mild and transient and no significant laboratory abnormalities were encountered. We conclude that a daily dose of 1 to 1.5 tablets b.i.d. of Sinemet CR as primary therapy for patients with Parkinson's disease is well tolerated and provides effective therapy.

Aged↗
PubMed1991

Dietary diversity in the US population, NHANES II, 1976-1980.

The extent of diversity in the diets of black and white adults (n = 11,658) aged 19 to 74 years was evaluated from 24-hour dietary recalls obtained in the second National Health and Nutrition Examination Survey. Each 24-hour recall was evaluated for the consumption of items from the dairy, meat, grain, fruit, and vegetable groups (Food Group Score). A second scoring method (Serving Score) evaluated every recall for consumption of at least two servings each from dairy, meat, fruit, and vegetable groups and four servings from the grain group. Only a third of the population surveyed reported consuming foods from all the food groups on the survey day; less than 3% reported consuming foods from all food groups in at least the recommended amount. Blacks scored lower on both types of diet diversity scores than whites. Both types of diversity scores showed a significant trend to increase with increasing income and level of education. Failure to consume any foods from the dairy, meat, grain, fruit, and vegetable groups was reported by 24%, 6%, 5%, 46%, and 18%, respectively, of the population on the survey day. The proportion of the population consuming at least the desired number of servings from each of these food groups was 51%, 71%, 29%, 29%, 61%, respectively. The results emphasize the need for major public campaigns directed at increasing the diversity of US diets. Special target groups include minorities and those with limited income and formal education.

Adult↗
PubMed1991

Food group intake patterns and associated nutrient profiles of the US population.

We developed a method for evaluating food group intake patterns using dietary recall data (n = 11,529) from the second National Health and Nutrition Examination Survey. We used this method to examine the relationship of these food group intake patterns to nutrient intake and to selected biochemical indexes of nutritional status. We evaluated each 24-hour dietary intake recall for the presence or omission of five broad food groups--dairy, meat, grain, fruit, and vegetable. The five most prevalent patterns and the proportion of the population reporting them was as follows: all food groups, 33.6%; no fruit, 23.9%; no dairy and fruit, 9.0%; no dairy, 8.0%; and no fruit and vegetable, 5.6%. In the most prevalent pattern, all food groups were consumed; this was the only pattern that provided mean amounts of all of the key vitamins and minerals at levels greater than or equal to the Recommended Dietary Allowances (RDAs). This pattern also was reported by the lowest proportion of individuals consuming less than 100% RDA of the key nutrients. Patterns in which both fruit and vegetables were consumed were associated with highest levels of serum vitamin C. The consistency of these results indicates that screening diets for food group consumption can quickly provide meaningful information about their quality.

Adult↗
PubMed1990

Diagnostic value of brush cytology in the diagnosis of bile duct carcinoma: a study in 65 patients with bile duct strictures.

Malignant strictures of the extrahepatic bile ducts are difficult to distinguish from benign strictures, particularly in patients with primary sclerosing cholangitis. Because attempts at diagnosing small cancers with fine-needle aspiration biopsy are not possible in the absence of an associated mass lesion and because the sensitivity of exfoliative biliary cytology is controversial, brush cytology has been used as a potential means of establishing a specific diagnosis of bile duct carcinoma. Herein we report our experience with this technique when performed on 65 patients over a 5-yr period. Each had at least one brushing. Thirty-seven were found to have bile duct carcinoma and 28 were found to have benign strictures. Of these 37, the first brushing was positive for malignancy in 15 (40%), whereas four (11%) had cells suspected but not diagnostic of malignancy. Thirteen patients with bile duct carcinoma whose initial brushings were negative for malignancy had second brushings. Of these, five (38%) had malignant cells, whereas three (24%) yielded suspicious cells. Three of the eight whose first two brushings were negative for malignancy were found to have malignant cells on the third brushing. In contrast, of the 28 patients with benign strictures, malignant cells were never found. However, in two patients, suspicious cells were reported with the first but not the second brushing. A single negative or suspicious cytological finding decreased the probability of bile duct carcinoma to 43%. Two and three sequential negative tests reduced the probability to 32% and 0%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Validation of a self-administered diet history questionnaire using multiple diet records.

The validity of a self-administered diet history questionnaire has been estimated using as the reference data the mean of three 4-day diet records collected over the year prior to the administration of the questionnaire, in 1985-1986. Subjects were women ages 45-70 years, participants in the Women's Health Trial Feasibility Study, a multi-center clinical trial in which some women were randomized to be taught to adopt and maintain a low-fat diet, while others maintained their usual diet. The questionnaire produced group mean nutrient estimates closely approximating the values obtained by three 4-day records, e.g. in the usual-diet group, 37.7% of calories from fat by both food records and by questionnaire, and in the low-fat group, 21.3% of calories from fat by food records and 23.7% of calories from fat by questionnaire. Correlations between questionnaire and diet records for per cent of calories from fat were 0.67 and 0.65 respectively in the two groups; most correlations were in the 0.5-0.6 range, and were similar to those achievable by a single 4-day food record.

Aged↗
PubMed1990

Diet and oral and pharyngeal cancer among blacks.

Data from a population-based multicenter case-control study were examined to assess for the first time the relationship between diet and oral and pharyngeal cancer among blacks. An increased intake of fruits and vegetables was associated with a decreased risk for oral cancer among both men and women, although the protective effect was stronger among men. Risk also declined in both sexes with an increase in the consumption of vitamin C and fiber and in men only for carotene and vitamin E. In both sexes, no associations were found with an intake of smoked, pickled, or charcoal-grilled meats or of hot beverages. However, the consumption of nitrite-containing meats was linked to increased risk among men. The dietary patterns of risk for blacks were generally similar to those previously reported for whites; however, a lower consumption of fruits and vegetables among blacks in this study may contribute to their higher rates of oral and pharyngeal cancer.

Adult↗
PubMed1990

Vitamin E intakes and sources in the United States.

Twenty-four-hour-recall data from 11,658 adults interviewed in the Second National Health and Nutrition Examination Survey (NHANES II) were used to estimate intakes of vitamin E and polyunsaturated fatty acids (PUFAs) in the United States. Although mean intakes of vitamin E were close to the recommended dietary allowance for both men and women (9.6 and 7.0 mg/d, respectively), median intakes were considerably lower (7.3 and 5.4 mg/d). If a ratio of vitamin E to PUFAs of greater than or equal to 0.4 is considered desirable, 23% of men and 15% of women had diets with low ratios. Ratios tended to decrease as PUFAs in the diet increased. The fruits-and-vegetables group and the fats-and-oils group each provided 20% of the vitamin E in the US diet. Increasing food choices from the fruits-and-vegetables group would provide low-fat sources of vitamin E for individuals whose intakes are likely to be inadequate.

Adult↗
PubMed1990

Dietary vitamin B-6 intake and food sources in the US population: NHANES II, 1976-1980.

Dietary vitamin B-6 intake and food sources were estimated from the Second National Health and Nutrition Examination Survey (NHANES II) dietary data for 11,658 adults aged 19-74 y. The average daily intake of vitamin B-6 was 1.48 +/- 0.01 mg (mean +/- SEM) for the total population, 1.85 +/- 0.02 for males and 1.14 +/- 0.01 for females. Seventy-one percent of males and 90% of females consumed less than the 1980 recommended dietary allowance (RDA) of vitamin B-6. Sixty-four percent of all survey respondents reported a ratio of vitamin B-6 to dietary protein of less than 0.02 (expressed as mg/g protein). Foods from animal and plant sources provided 48% and 52% of the total vitamin B-6, respectively. Vitamin B-6 intake decreased (P less than 0.0001) with increasing age and decreasing education and income status. Beef steaks and roasts, alcoholic beverages, potatoes, ready-to-eat cereals, and milk were important dietary sources of vitamin B-6.

Adult↗
PubMed1990

Use of vitamin and mineral supplements: demographics and amounts of nutrients consumed. The 1987 Health Interview Survey.

Data from the 1987 National Health Interview Survey show that 51.1% of the adults aged 18-99 years in the United States consumed a vitamin/mineral supplement in the past year, but that only 23.1% did so daily. Whites, women, and older individuals were more likely than blacks, men, and younger individuals to consume supplements regularly. Multivitamins were the most commonly consumed supplement, followed by vitamin C, calcium, vitamin E, and vitamin A. Results suggest that supplementation practices have changed little since the 1970s. Results regarding the amounts of nutrients obtained from supplements show that a food frequency type of methodology collects reasonably accurate data reflecting intake of supplements over the past year. Few, if any, individuals were consuming nutrients in amounts considered toxic. Although vitamin and mineral supplementation is a common health habit, it appears not to pose a significant health risk for most of the population.

Adolescent↗
PubMed1990

A reduced dietary questionnaire: development and validation.

A reduced questionnaire was developed by successively omitting segments of the full (98-item) Block questionnaire and calculating the correlations between nutrient estimates produced by the full and reduced versions. The reduced version contains 60 food items and requires 17 minutes to administer by an interviewer. It is intended to capture all nutrients in the diet, as is the full version. The reduced version was validated against three four-day records in a group of middle-aged women, and against two seven-day records collected 10-15 years ago in a group of older men. The absolute value of macronutrients estimated by the reduced questionnaire was lower than food-record estimates, but most micronutrients were not underestimated. For macronutrients correlations with food records were slightly lower with the reduced questionnaire, but for micronutrients there was only slight or no reduction in correlations as a result of using the reduced version. The brief version may be useful in studies that cannot allow the 30-35 minutes required for the full-length questionnaire.

Aged↗
PubMed1990

Use of adjustment factors with a brief food frequency questionnaire to obtain nutrient values.

The 100-item National Cancer Institute (Block) Food Frequency Questionnaire was created to measure an individual's relative nutrient intake as well as absolute nutrient values. A 60-item, brief questionnaire was then developed; its results correlate well with results from the 100-item questionnaire and with food record data. Adjustment factors, presented here, were developed that allow investigators to use the shorter questionnaire while obtaining nutrient values nearer the correct absolute values than those from the brief questionnaire alone. Data from the National Health and Nutrition Examination Survey II (1976-1980) and the first quarter of the National Health Interview Survey (1987) were used in developing the adjustment factors. The brief questionnaire was administered to approximately 22,000 subjects in the National Health Interview Survey. When the adjustment factors were applied to data from the second, third, and fourth quarters of the National Health Interview Survey, the adjusted values of 17 micro- and macronutrients were on average within 0.51% and 1.17% of estimates obtained by 24-hour recall in the National Health and Nutrition Examination Survey II, for men and women, respectively. Correlations between the adjusted nutrient values and absolute nutrient consumption, as measured by diet diaries in three smaller studies, were nearly the same or somewhat better than correlations with the unadjusted brief questionnaire.

Adolescent↗
PubMed1990

Fruit and vegetables in the American diet: data from the NHANES II survey.

Twenty-four hour dietary recall data from the Second National Health and Nutrition Examination Survey (1976-80) were used to estimate the numbers of servings of fruit and vegetables consumed by Black and White adults, to examine the types of servings (e.g., potatoes, garden vegetables, fruit, and juice), and to estimate the mean intake of calories, fat, dietary fiber, and vitamins A and C by number of servings. An estimated 45 percent of the population had no servings of fruit or juice and 22 percent had no servings of a vegetable on the recall day. Only 27 percent consumed the three or more servings of vegetables and 29 percent had the two or more servings of fruit recommended by the US Departments of Agriculture and of Health and Human Services; 9 percent had both. Consumption was lower among Blacks than Whites. The choice of vegetables lacked variety. Diets including at least three servings of vegetables and two servings of fruit contained about 17 grams of dietary fiber. Although caloric and fat intake increased with increasing servings of fruit and vegetables, the percent of calories from fat remained relatively constant. Although these data are 10 years old, more recent surveys have shown similar results. The discrepancy between dietary guidelines and the actual diet suggests a need for extensive public education.

Adult↗
PubMed1990

The apparent validity of diet questionnaires is influenced by number of diet-record days used for comparison.

The effect of the number of diet records used as the reference data on the apparent validity of a diet history questionnaire was examined using data from 97 participants in the Women's Health Trial feasibility study. Pearson correlation coefficients were computed between the estimates of usual individual intake from the questionnaire and estimates from the mean of three 4-day records obtained over a 1-year period, the mean of the two most recent records, and the record obtained 1 year after the start of the study. The results illustrate that the apparent validity of a questionnaire increases when it is compared with a greater number of 4-day food records. The correlations increased for most nutrients when the baseline food record was included, despite the fact that it was completed at a time not targeted by the questionnaire. These findings suggest that greater effort should be given to obtaining more diet-record days when validating other dietary assessment instruments.

Aged↗
PubMed1989

Human dietary assessment: methods and issues.

It is possible that a "good" diet may enhance response to a chemopreventive agent, or that a diet deficient in some nutrients may weaken host defenses or host response to the agent. Thus, dietary intake should be assessed in chemoprevention as well as dietary studies. The advantages and disadvantages of several methods are presented. In addition, several principles and issues involved in dietary studies are discussed. Studies should attempt to assess the whole diet, not one or a few nutrients. Interpretation of the results of dietary studies can be seriously flawed and conclusions incorrect if only one or a few nutrients are assessed. Studies that ask about vegetable products but calculate only a fiber index are forced into drawing conclusions about fiber, when the true effective component may be elsewhere. Investigators should be cautious in the analysis and interpretation of results involving correlated nutrients. If two variables are quite highly correlated, either positively or negatively, a nutrient which has no effect may appear to have one, merely by being correlated with the other. Some examples are presented. Misclassification or measurement error is a serious problem for all dietary methods, although for different reasons. For most frequency or few-day-record methods, sample sizes must be multiplied several-fold over the sample size which standard formulas produce, to retain power in the face of measurement error.

Data Collection↗
PubMed1989

Folate intake and food sources in the US population.

Dietary data from 24-h recalls collected in the Second National Health and Nutrition Examination Survey (NHANES II) were analyzed to determine intake and food sources of folate in US adults between ages 19 and 74 y. Mean daily folate intake was 242 +/- 2.8 micrograms (means +/- SEM) for all adults, 281 +/- 3.6 micrograms for males, and 207 +/- 2.9 micrograms for females. Daily intake per 1000 kcal was 130 +/- 1.3 micrograms for all adults 122 +/- 1.3 micrograms for males, and 137 +/- 1.7 micrograms for females. Based on the Recommended Dietary Allowance of 400 micrograms/d, our results suggest that folate intake in the United States is low, particularly among women and blacks. Intake by age, education, and poverty index is discussed. Orange juice, white breads, dried beans, green salad, and ready-to-eat breakfast cereals are the major food sources of folate on a given day, contributing 37% of total folate intake.

Adult↗