William O. Thompson

The use of transcranial ultrasonography to predict stroke in sickle cell disease

BACKGROUND Stroke, especially cerebral infarction, is a major cause of morbidity and mortality in children with sickle cell disease. Primary prevention of stroke by transfusion therapy may be feasible if there is a way to identify the patients at greatest risk. Transcranial Doppler ultrasonography can measure flow velocity in the large intracranial arteries. The narrowing of these arteries, which leads to cerebral infarction, is characterized by an increased velocity of flow. METHODS Using transcranial Doppler ultrasonography, we prospectively measured the velocity of cerebral blood flow in children and young adults being followed because of sickle cell disease. The results were classified as either normal or abnormal on the basis of the highest velocity of flow in the middle cerebral artery. Abnormal velocity was defined as a flow greater than or equal to 170 cm per second, a definition determined by post hoc analysis to maximize the predictive success of the test. The end point was a clinically apparent first cerebral infarction. RESULTS Two hundred eighty-three transcranial ultrasound examinations were performed in 190 patients with sickle cell disease (age at entry, 3 to 18 years). After an average follow-up of 29 months, cerebral infarction was diagnosed in seven patients. In 23 patients the results of the ultrasound examinations were abnormal, and in 167 patients they were normal. The clinical and hematologic characteristics of the two groups were similar, but six of the seven strokes occurred among the 23 patients with abnormal ultrasound results (P less than 0.00001 by Fishers exact test). In this group, the relative risk of stroke was 44 (95 percent confidence interval, 5.5 to 346). CONCLUSIONS Transcranial ultrasonography can identify the children with sickle cell disease who are at highest risk for cerebral infarction. Periodic ultrasound examinations and the selective use of transfusion therapy could make the primary prevention of stroke an achievable goal.

Observations on Physical Activity in Physical Locations: Ager Gender, Ethnicity, and Month Effects

The level of physical activity of 3- and 4-year-old children was assessed in alternative physical locations by month and time of day and by age, gender, and ethnicity. Physical activity was assessed by observation with the Childrens Activity Rating Scale (CARS) for up to 12 hours from 7:00 am to 7:00 pm. A sample of 191 three- and four-year-old children was observed for up to four times in the course of a year. The sample was tri-ethnic. Boys were significantly more active than girls. Activity was consistently higher outside than inside. There were significant differences in the amount of time children in this age group spent inside versus outside by time of year; the activity levels of boys and girls differed by time of year, particularly when outside. A model including gender, month, and location terms accounted for 75% of the variance in physical activity. These data further documented gender differences in physical activity among very young children using measures not subject to self-report biases but did not explain or clarify the gender differences. The substantial differences by physical location and time of year deserve future attention, but more refined methods will be needed to balance data by location and important seasonal times. An inference from these results is that activity levels among young children may be increased by encouraging them to spend more time outdoors.

Unilateral cerebral inactivation produces differential left/right heart rate responses

We studied heart rate following unilateral hemispheric inactivation by intracarotid amobarbital in 25 patients undergoing preoperative evaluation for epilepsy surgery. Heart rate increased after left hemisphere inactivation, but decreased following right hemisphere inactivation. The results are consistent with differential left/right cerebral hemispheric effects on autonomic function, and appear related to functional and anatomic asymmetries in both the central and peripheral nervous systems.

Effect of physical training on total and visceral fat in obese children

PURPOSE Children with high levels of total body fat mass (TFM) and visceral adipose tissue (VAT) have elevated levels of certain risk factors for coronary artery disease and non-insulin-dependent diabetes mellitus. We tested the hypothesis that controlled physical training, without dietary intervention, would have a favorable impact on VAT and percent body fat (%BF) in obese children. METHODS A volunteer sample of 74 obese children, 7-11 yr of age, accepted random assignment to physical training or control groups. Before and after 4 months of intervention, measurements were obtained for VAT, TFM, %BF, daily physical activity, and cardiovascular fitness. The intervention involved 4 months of controlled physical training 5 d x wk(-1), 40 min per session, at a mean heart rate (HR) of 157 beats x min(-1). The estimated energy expenditure (EE) per training session was 925+/-201 kJ. RESULTS Compared with the control group, the physical training group declined significantly in %BF (delta = -2.2%) (P < 0.01), TFM (delta = -3.1%) (P < 0.01), and subcutaneous abdominal adipose tissue (delta = - 16.1%) (P < 0.05), and increased significantly in fat-free mass (delta = +6.1%) (P < 0.05) and moderate-to-very hard physical activity (delta = +14.1%) (P < 0.05). The increase in VAT was significantly less in the physical training group (delta = +0.5%) as compared with that in the control group (delta = +8.1%) (P < 0.05). CONCLUSIONS This study showed that during physical training obese children: 1) were capable of participating in a substantial amount of high intensity physical training over a 4-month period: 2) accumulated significantly less VAT as compared with nonexercising controls; and 3) experienced other beneficial changes in total and regional body composition.

Comparative cognitive effects of phenobarbital, phenytoin, and valproate in healthy adults.

The relative effects of antiepileptic drugs (AEDs) on cognition are controversial.We compared the cognitive effects of phenobarbital, phenytoin, and valproate in 59 healthy adults using a randomized, double-blind, incomplete-block, crossover design. Cognitive assessments were conducted at baseline, after 1 month on each drug (two AEDs per subject), and at two repeat baselines 11 weeks after each AED treatment. The neuropsychological battery included 12 tests, yielding 22 variables: Choice Reaction Time, P3 Event-Related Potential, Finger Tapping, Lafayette Grooved Pegboard, Selective Reminding Test, Paragraph Memory, Complex Figures, Symbol Digit Modalities Test, Stroop Test, Visual Serial Addition Test, Hopkins Symptom Checklist, and Profile of Mood States. More than one-half of the variables exhibited AED effects when compared with nondrug baselines, and all three AEDs produced some untoward effects. Differential AED effects on cognition were present for approximately one-third of the variables. Phenobarbital produced the worst performance; there was no clinically significant difference between phenytoin and valproate. NEUROLOGY 1995;45: 1494-1499

Development and evaluation of a school intervention to increase fruit and vegetable consumption among 4th and 5th grade students

THOMPSON,3 SANDRA B. LEONARD,4 PATRICIA RILEY,2 JANICE BARANOWSKI,3 BONNIE DUDOVITZ, 6 AND MARY SMYTH 6 lGeorgia Prevention Institute, Department of Pediatrics, Medical College of Georgia, Augusta, Georgia 30912-3715; 2Division of Behavioral Sciences and Health Education, School of Public Health, Emory University, Atlanta, Georgia 30329; 30fIice of Biostatistics, Medical College of Georgia, Augusta, Georgia 30912-4900; 4Georgia Institute of Human Nutrition, Department of Medicine, Medical College of Georgia, Augusta, Georgia 30912-3102; sOfIice of Public Health Practice, School of Public Health, Emory University, Atlanta, Georgia 30329; and 6Department of Epidemiology, University of Minnesota, Minneapolis, Minnesota, 55454.

Association among serum lipid and lipoprotein concentrations and physical activity, physical fitness, and body composition in young children

OBJECTIVE To examine the relationships among indicators of physical activity, physical fitness, and body composition with serum lipid and lipoprotein levels in young children. DESIGN Cross-sectional and 1-year prospective cohort. SETTING Studies of Child Activity and Nutrition (SCAN) program, Galveston, Tex. SUBJECTS One hundred twenty-three 4- or 5-year-old black, Hispanic (of Mexican origin), and white children. MEASUREMENTS Body composition, resting heart rate, and cardiovascular fitness variables and serum lipid and lipoprotein levels were measured at age 3 or 4 years (study year 1) and at age 4 or 5 years (study year 2), and day-long heart rate was measured and the Childrens Activity Rating Scale was administered between study years 1 and 2. RESULTS Year-1 waist/hip ratios were inversely correlated with total serum cholesterol (TSC) and low-density lipoprotein (LDL) levels. Mean activity level was inversely correlated with waist/hip ratios. On the basis of multiple regression analysis, the sum of seven skin-fold measurements, height, and gender explained 15.4% of the variation in triglyceride levels. The sum of seven skin-fold measurements was inversely correlated with the high-density lipoprotein (HDL) level. Resting heart rate, waist/hip ratio, and the slope of the exercise heart rate during fitness testing explained 19.5% of the variation in the concentration of an HDL subclass, HDL2. These childrens levels of physical activity were associated with higher fitness levels. Year-1 waist/hip ratios and year-2 sum of seven skin-fold measurements were positively correlated with the LDL/HDL and TSC/HDL ratios. CONCLUSION Higher levels of cardiovascular fitness and lower levels of fatness were associated with more favorable serum lipid and lipoprotein levels in these young children. Physical activity appeared to have an indirect association with serum lipid and lipoprotein values through its relationship with higher fitness levels and lower levels of fatness.

Accuracy of Fourth-Graders' Dietary Recalls of School Breakfast and School Lunch Validated with Observations: In-Person versus Telephone Interviews

OBJECTIVE To investigate the accuracy of childrens dietary recalls of school breakfast and school lunch validated with observations and obtained during in-person versus telephone interviews. DESIGN Each child was observed eating school breakfast and school lunch and was interviewed that evening about that days intake. SETTING Ten elementary schools. PARTICIPANTS A sample of fourth-graders was randomly selected within race (black, white) and gender strata, observed, and interviewed in person (n = 33) or by telephone (n = 36). MAIN OUTCOMES MEASURED Rates for omissions (items observed but not reported) and intrusions (items reported but not observed) were calculated to determine accuracy for reporting items. A measure of total inaccuracy was calculated to determine inaccuracy for reporting items and amounts combined. ANALYSIS Analysis of variance; chi-square. RESULTS Interview type (in person, telephone) did not significantly affect recall accuracy. For omission rate, intrusion rate, and total inaccuracy, means were 34%, 19%, and 4.6 servings for in-person recalls and 32%, 16%, and 4.3 servings for telephone recalls of school breakfast and school lunch. CONCLUSIONS AND IMPLICATIONS The accuracy of childrens recalls of school breakfast and school lunch is not significantly different whether obtained in person or by telephone. Whether interviewed in person or by telephone, children reported only 67% of items observed; furthermore, 17% of items reported were not observed.

How children remember what they have eaten

OBJECTIVES To determine whether students could verbalize, within 1 1/2 hours, how they remembered items eaten at the school lunch; to determine whether the categories of self-reported retrieval mechanisms were similar for two interview styles, integrated and nonintegrated; and to determine the effect of the two interview style on the accuracy of reporting items eaten by comparing reports with direct observation. DESIGN Two styles of dietary intake interviews were compared with observed intake in a school lunch setting. SETTING Two elementary schools in Georgia. SUBJECTS/SAMPLES Eighty-two of 106 fourth graders from four classes volunteered; 24 (six per class) were randomly selected and assigned to an interview style. Students interviewed using a nonintegrated style verbalized how they remembered after they had reported everything eaten. Students interviewed using an integrated style verbalized how they remembered at the same time they reported eating each item. Both interview styles included free report followed by prompted report. MAIN OUTCOME MEASURES Reported retrieval mechanisms were coded into 13 categories. Five measures of performance (specific match rate, general match rate, intrusion rate, omission rate, and overall match rate) were calculated by interview style for free report and prompted report separately. STATISTICAL ANALYSES PERFORMED We analyzed the effect of interview style on the number of students reaching 100% accuracy after prompting and on accuracy of reporting condiments using Fishers exact test. RESULTS Most students could articulate how they remembered items eaten. Reported retrieval mechanism categories were comparable for both interview styles. Visual imagery, usual practice, behavior chaining, and preference were the most commonly reported retrieval mechanisms. Accuracy of free reports did not differ by interview style; however, the nonintegrated interview style produced dietary self-reports with fewer condiment omissions during free report and higher accuracy after prompting. APPLICATIONS Determining what retrieval mechanisms children commonly use for remembering items eaten may help researchers design cues to improve the accuracy of dietary self-reports. More accurate dietary self-reports could markedly affect the many types of research that use dietary assessment.

Reliability and variability of indicators of heart-rate monitoring in children.

We describe the daily heart-rate patterns and the between-day and within-day reliabilities of several heart rate indicators measured in 131 Anglo-, African-, and Mexican-American children aged 5-7 yr. Heart rates were measured over 12 waking hours with a Quantum XL Telemetry heart rate monitor. The percent of heart rates 25% above resting heart rate, an index of physical activity heart rate (PAHR-25 index), was found to have the highest within-day (0.92) and between-day (0.81) reliabilities. The Spearman-Brown prophecy formula indicated that only 9.3 h of observation would be needed to maintain a within-day reliability of 0.90. The percentage of heart rates 50% above resting heart rate (PAHR-50) was found to have slightly lower within-day (0.88) and between-day (0.56) reliability. Principal components analysis revealed that the PAHR-25 and PAHR-50 indicies only had one component throughout the day. The PAHR-25 and PAHR-50 indicies were weakly correlated with age, suggesting that they may be good indicators of relative PAHR. Male children had higher (P < or = 0.025) PAHR-25 index scores than females. There were no gender or ethnic differences in the PAHR-50 index.