Mark S. Litaker

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.

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.

Effects of exercise training and its cessation on components of the insulin resistance syndrome in obese children

OBJECTIVE: To determine the effect of exercise training (ET) on components of the insulin resistance syndrome (IRS) in obese children.DESIGN: Randomized, modified cross-over study, with subjects assigned to one of two conditions: (1) 4 months of ET followed by 4 months of no-ET; or (2) 4 months of no-ET followed by 4 months of ET. Measurements were made at three time points: 0, 4 and 8 months.SUBJECTS: 79 obese, but otherwise healthy children (age: 7–11 y, percent fat (%fat) 27–61%).MEASUREMENTS: Plasma lipid and lipoprotein concentrations, plasma insulin and glucose concentrations; %fat; submaximal heart rate (HR) as an index of fitness.EXERCISE TRAINING: ET was offered 5 d/week 40 min/d. For the 73 children who completed 4 months of ET, the mean attendance was 80% (that is, 4 d/week) and the average HR during ET was 157 bpm.RESULTS: Significant (P<0.05) group x time interactions were found for plasma triglyceride (TG) and insulin concentrations and %fat. The average change for both groups, from just before ET to just after the 4 month ET was −0.24 mmolċl−1 for TG, −25.4 pmolċl−1 for insulin and −1.6 units for %fat. When Group 1 ceased ET, over the following 4 month period the average change for insulin was +26.6 pmolċl−1 and for %fat +1.3 units.CONCLUSION: Some components (plasma TG, insulin, %fat) of the IRS are improved as a result of 4 months of ET in obese children. However, the benefits of ET are lost when obese children become less active.

Physical training improves insulin resistance syndrome markers in obese adolescents

INTRODUCTION The purpose of this study was to test the hypothesis that physical training (PT), especially high-intensity PT, would have a favorable effect on components of the insulin resistance syndrome (IRS) in obese adolescents. METHODS Obese 13- to 16-yr-olds (N = 80) were randomly assigned to one of the following 8-month interventions; 1) lifestyle education (LSE)-alone every 2 wk, 2) LSE+moderate-intensity PT, and 3) LSE+high-intensity PT. PT was offered 5 d x wk(-1). Plasma triacylglycerol (TAG), total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), very low-density lipoprotein cholesterol (VLDLC), low-density lipoprotein cholesterol (LDLC), low-density lipoprotein (low density lipoprotein (LDL)) particle size, apolipoproteins AI and B, glucose, insulin, and blood pressure were measured with standardized methods. RESULTS The intent-to-treat analyses for all subjects who completed pre- and post-tests regardless of their adherence to the interventions showed that the LSE+high-intensity PT group had more favorable changes than the LSE-alone group in TAG level (P = 0.012), TC/HDLC (P = 0.013), and diastolic blood pressure (P = 0.031). For efficacy analyses, all PT subjects who attended at least 2 d x wk(-1) (40%) were combined into one group (LSE+PT) and compared with the LSE-alone group. These two-group analyses showed significant interactions (P < 0.001) between baseline values and group membership for deltaTAG, deltaVLDLC, and deltaTC/HDLC, such that subjects who had the least favorable baseline values showed the most beneficial impact of the PT. Of particular interest was a favorable effect of the PT on LDL particle size. CONCLUSION PT, especially high-intensity PT, had a favorable effect on several IRS markers in obese adolescents.

Lateralization of Minicolumns in Human Planum temporale Is Absent in Nonhuman Primate Cortex

Gross analyses of large brain areas, as in MRI studies of macroanatomical structures, average subtle alterations in small regions, inadvertently missing significant anomalies. We developed a computerized imaging program to microscopically examine minicolumns and used it to study Nissl-stained slides of normal human, chimpanzee, and rhesus monkey brains in a region of the planum temporale. With this method, we measured the width of cell columns, the peripheral neuropil space, the spacing density of neurons within columns, and the Gray Level index per minicolumn. Only human brain tissue revealed robust asymmetry in two aspects of minicolumn morphology: wider columns and more neuropil space on the left side. This asymmetry was absent in chimpanzee and rhesus monkey brains.

Efficacy of Theory-Based Activities for Behavioral Symptoms of Dementia

BackgroundAgitation and passivity are behavioral symptoms exhibited by 90% of nursing home residents with dementia. They account for many poor health outcomes, caregiver burden, and increased costs of long-term care. ObjectivesThis study tested the efficacy of recreational activities derived from the Need-driven Dementia-compromised Behavior (NDB) model: activities matched to skill level only; activities matched to style of interest only; and a combination of both (NDB-derived) for responding to the behavioral symptoms of dementia. MethodsThirty participants were randomly assigned to 1 of 6 possible order-of-condition presentations in this crossover experimental design with repeated measures of dependent variables. Trained research assistants, blind to condition match, implemented each condition for 12 consecutive days. Measures of engagement (time on task and participation), affect, and behavioral symptoms (agitation and passivity) were taken from videotape recordings of each session. Mood was measured with the Dementia Mood Picture Test. The primary analysis method was mixed-model analysis of variance. ResultsSignificantly more time on task, greater participation, more positive affect, and less passivity were found under NDB-derived and matched to interest only treatments compared with the matched to skill level only treatment or baseline. Agitation and negative affect improved under all treatments compared with baseline. There was no significant change in mood. DiscussionThe NDB-derived activities are tailored to meet individual needs and improve behavioral symptoms associated with dementia. These findings help to explain factors that produce behavioral symptoms and the mechanisms that underlie their successful treatment.

A randomized clinical trial of theory-based activities for the behavioral symptoms of dementia in nursing home residents

OBJECTIVES: To test the main and interactive effects of activities derived from the Need‐Driven Dementia‐Compromised Behavior model for responding to behavioral symptoms in nursing home residents.

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.

Factors that relate to activity engagement in nursing home residents

Many nursing home residents are unoccupied and at risk for poor health outcomes because of inactivity. The purpose of this study was to identify characteristics of residents with dementia that predict engagement in activities when activities are implemented under ideal conditions. Data from a clinical trial that tested the efficacy of individually prescribed activities were used to address the study aim. Thirty subjects were videotaped daily for 12 days during 20-minute activity sessions. Measures of engagement (time on task and level of participation) were taken from these videotapes. Univariate logistic regression analyses indicated that cognitive status and physical function explained a significant amount of variance in engagement. Efforts to promote function may facilitate even greater benefits from prescribed activities by improving capacity for engagement.

Reverse versus forward order reporting and the accuracy of fourth-graders’ recalls of school breakfast and school lunch

BACKGROUND Do children recall school breakfast and school lunch intake during 24-h recalls more accurately when prompted to report meals and snacks in reverse versus forward order? METHODS One hundred twenty-one fourth-graders stratified by race (Black, White) and gender were each observed and interviewed twice (once per order) regarding the previous days intake. Omission and intrusion rates determined accuracy for reporting items. Total inaccuracy determined accuracy for reporting items and amounts. RESULTS Results failed to indicate significant effects of interviewer, weekday, sequence (first or second recall), or race on omission rates, intrusion rates, or total inaccuracy. A significant order by gender interaction was found for omission rates, which were lower (i.e., better) for males for reverse (53%) versus forward recalls (62%), but not females (61 versus 53%) (P < 0.008). Intrusion rates were acceptable for males for 54% of reverse recalls and 40% of forward recalls (P = 0.095). Means were 57 and 32%, and 6.4 servings for omission rate, intrusion rate, and total inaccuracy for reverse recalls, and 56 and 39%, and 6.9 servings for forward recalls. CONCLUSIONS Prompting children to report in reverse versus forward order improved omission and intrusion rates for males more so than females. Regardless of reverse or forward order, children reported <50% of items observed; furthermore, >30% of items reported were not observed. Research is needed to enhance accuracy of childrens dietary recalls.