Sari Acra

Predicting Energy Expenditure of Physical Activity Using Hip- and Wrist-Worn Accelerometers

To investigate the association between physical activity and health, we need accurate and detailed free-living physical activity measurements. The determination of energy expenditure of activity (EEACT) may also be useful in the treatment and maintenance of nutritional diseases such as diabetes mellitus. Minute-to-minute energy expenditure during a 24-h period was measured in 60 sedentary normal female volunteers (35.4 +/- 9.0 years, body mass index 30.0 +/- 5.9 kg/m2), using a state-of-the-art whole-room indirect calorimeter. The activities ranged from sedentary deskwork to walking and stepping at different intensities. Body movements were simultaneously measured using a hip-worn triaxial accelerometer (Tritrac-R3D, Hemokentics, Inc., Madison, Wisconsin) and a wrist-worn uniaxial accelerometer (ActiWatch AW64, MiniMitter Co., Sunriver, Oregon) on the dominant arm. Movement data from the accelerometers were used to develop nonlinear prediction models (separately and combined) to estimate EEACT and compared for accuracy. In a subgroup (n=12), a second 24-h study period was repeated for cross-validation of the combined model. The combined model, using Tritrac-R3D and ActiWatch, accurately estimated total EEACT (97.7 +/- 3.2% of the measured values, p=0.781), as compared with using ActiWatch (86.0 +/- 4.7%, p<0.001) or Tritrac-R3D (90.0 +/- 4.6%, p<0.001) alone. This model was also accurate for all intensity categories during various physical activities. The subgroup cross-validation also showed accurate and reproducible predictions by the combination model. In this study, we demonstrated that movement measured using accelerometers at the hip and wrist could be used to accurately predict EEACT of various types and intensity of activities. This concept can be extended to develop valid models for the accurate measurement of free-living energy metabolism in clinical populations.

Evaluation of guided imagery as treatment for recurrent abdominal pain in children: a randomized controlled trial

BackgroundBecause of the paucity of effective evidence-based therapies for children with recurrent abdominal pain, we evaluated the therapeutic effect of guided imagery, a well-studied self-regulation technique.Methods22 children, aged 5 – 18 years, were randomized to learn either breathing exercises alone or guided imagery with progressive muscle relaxation. Both groups had 4-weekly sessions with a therapist. Children reported the numbers of days with pain, the pain intensity, and missed activities due to abdominal pain using a daily pain diary collected at baseline and during the intervention. Monthly phone calls to the children reported the number of days with pain and the number of days of missed activities experienced during the month of and month following the intervention. Children with ≤ 4 days of pain/month and no missed activities due to pain were defined as being healed. Depression, anxiety, and somatization were measured in both children and parents at baseline.ResultsAt baseline the children who received guided imagery had more days of pain during the preceding month (23 vs. 14 days, P = 0.04). There were no differences in the intensity of painful episodes or any baseline psychological factors between the two groups. Children who learned guided imagery with progressive muscle relaxation had significantly greater decrease in the number of days with pain than those learning breathing exercises alone after one (67% vs. 21%, P = 0.05), and two (82% vs. 45%, P < 0.01) months and significantly greater decrease in days with missed activities at one (85% vs. 15%, P = 0.02) and two (95% vs. 77%. P = 0.05) months. During the two months of follow-up, more children who had learned guided imagery met the threshold of ≤ 4 day of pain each month and no missed activities (RR = 7.3, 95%CI [1.1,48.6]) than children who learned only the breathing exercises.ConclusionThe therapeutic efficacy of guided imagery with progressive muscle relaxation found in this study is consistent with our present understanding of the pathophysiology of recurrent abdominal pain in children. Although unfamiliar to many pediatricians, guided imagery is a simple, noninvasive therapy with potential benefit for treating children with RAP.

Activation of epidermal growth factor receptor mediates mucin production stimulated by p40, a Lactobacillus rhamnosus GG-derived protein.

Background: p40, a Lactobacillus rhamnosus GG-derived protein, ameliorates intestinal injury and inflammation through transactivation of the EGF receptor (EGFR). Results: p40 up-regulates Muc2 gene expression and mucin production in LS174T cells and in mouse colonic epithelium in an EGFR-dependent manner. Conclusion: p40 stimulates mucin production through transactivation of EGFR. Significance: p40-stimulated mucin production may play a role in protecting the intestinal epithelium from injury. The mucus layer coating the gastrointestinal tract serves as the first line of intestinal defense against infection and injury. Probiotics promote mucin production by goblet cells in the intestine. p40, a Lactobacillus rhamnosus GG-derived soluble protein, has been shown to transactivate the EGF receptor (EGFR) in intestinal epithelial cells, which is required for inhibition of apoptosis and preservation of barrier function in the colon, thereby ameliorating intestinal injury and colitis. Because activation of EGFR has been shown to up-regulate mucin production in goblet cells, the purpose of this study was to investigate the effects and mechanisms of p40 regulation of mucin production. p40 activated EGFR and its downstream target, Akt, in a concentration-dependent manner in LS174T cells. p40 stimulated Muc2 gene expression and mucin production in LS174T cells, which were abolished by inhibition of EGFR kinase activity, down-regulation of EGFR expression by EGFR siRNA transfection, or suppression of Akt activation. Treatment with p40 increased mucin production in the colonic epithelium, thus thickening the mucus layer in the colon of wild type, but not of Egfrwa5 mice, which have a dominant negative mutation in the EGFR kinase domain. Furthermore, inhibition of mucin-type O-linked glycosylation suppressed the effect of p40 on increasing mucin production and protecting intestinal epithelial cells from TNF-induced apoptosis in colon organ culture. Thus, these results suggest that p40-stimulated activation of EGFR mediates up-regulation of mucin production, which may contribute to the mechanisms by which p40 protects the intestinal epithelium from injury.

Patterns of physical activity in free-living adults in the Southern United States.

Objective: To examine the relationship between the amount and patterns of physical activity (PA), body fatness, and age in a heterogeneous adult population in the free living.Design: Cross-sectional study of the amount of PA over a 1-week period. The amount of body movements during PA (PA counts*103) and time spent on various PA intensity categories were calculated from a triaxial accelerometer and compared with subject characteristics, including body fat from hydrodensitometry.Participants: Adult healthy men (n=48) and women (n=72) were recruited from the Nashville, Tennessee area and their PA was monitored in their free-living environment.Results: The average weekday PA counts (176.5±60.3, P=0.002, r 2=0.294), PA counts day-to-day variability (47.3±32.7, P=0.002, r 2=0.286), daily maximum PA counts (241.9±89.2, P=0.001, r 2=0.327), minute-to-minute variability on weekdays (0.281±0.091, P=0.001, r 2=0.362), and the difference between maximum and minimum daily PA counts (130.6±78.3, P=0.008, r 2=0.243) were significantly and negatively correlated with body fatness. During awake time, both men and women spent 10–12 h on low intensity (1.0–2.9 metabolic equivalents (METs)) PA, approximately 1 h on moderate (3.0–5.9 MET), and less than 10 min on vigorous (>6.0 MET) PA each day. On weekends, men and women spent more time at rest (1 MET), less time on low-intensity PA, and men spent more time on moderate PA than on weekdays.Conclusions: In adults living in the Southern US the amount of free-living PA was negatively correlated with body fatness. Both men and women spent the majority of active time on low and moderate PA. PA patterns on weekends were different than on weekdays and were related to sex and age, but not to body fatness.Sponsorship: National Institutes of Health, US.

Activation of EGF Receptor Mediates Mucin Production stimulated by p40, a Lactobacillus rhamnosus GG-derived Protein

Background: p40, a Lactobacillus rhamnosus GG-derived protein, ameliorates intestinal injury and inflammation through transactivation of the EGF receptor (EGFR). Results: p40 up-regulates Muc2 gene expression and mucin production in LS174T cells and in mouse colonic epithelium in an EGFR-dependent manner. Conclusion: p40 stimulates mucin production through transactivation of EGFR. Significance: p40-stimulated mucin production may play a role in protecting the intestinal epithelium from injury. The mucus layer coating the gastrointestinal tract serves as the first line of intestinal defense against infection and injury. Probiotics promote mucin production by goblet cells in the intestine. p40, a Lactobacillus rhamnosus GG-derived soluble protein, has been shown to transactivate the EGF receptor (EGFR) in intestinal epithelial cells, which is required for inhibition of apoptosis and preservation of barrier function in the colon, thereby ameliorating intestinal injury and colitis. Because activation of EGFR has been shown to up-regulate mucin production in goblet cells, the purpose of this study was to investigate the effects and mechanisms of p40 regulation of mucin production. p40 activated EGFR and its downstream target, Akt, in a concentration-dependent manner in LS174T cells. p40 stimulated Muc2 gene expression and mucin production in LS174T cells, which were abolished by inhibition of EGFR kinase activity, down-regulation of EGFR expression by EGFR siRNA transfection, or suppression of Akt activation. Treatment with p40 increased mucin production in the colonic epithelium, thus thickening the mucus layer in the colon of wild type, but not of Egfrwa5 mice, which have a dominant negative mutation in the EGFR kinase domain. Furthermore, inhibition of mucin-type O-linked glycosylation suppressed the effect of p40 on increasing mucin production and protecting intestinal epithelial cells from TNF-induced apoptosis in colon organ culture. Thus, these results suggest that p40-stimulated activation of EGFR mediates up-regulation of mucin production, which may contribute to the mechanisms by which p40 protects the intestinal epithelium from injury.

The relationship of oxidative stress, adiposity and metabolic risk factors in healthy Black and White American youth

What is already known about this subject African Americans are disproportionately affected by obesity and other metabolic risk factors in comparison to White Americans. Increasing prevalence of obesity has been associated with concomitant increases in childhood hypertension, dyslipidaemia and type 2 diabetes. Oxidative stress is associated with obesity in both adults and children.

Effect of modest caloric restriction on oxidative stress in women, a randomized trial.

Objectives It is not established to what extent caloric intake must be reduced to lower oxidative stress in humans. The aim of this study was to determine the effect of short-term, moderate caloric restriction on markers of oxidative stress and inflammation in overweight and obese premenopausal women. Materials/Methods Randomized trial comparison of 25% caloric restriction (CR) or control diet in 40 overweight or obese women (body mass index 32±5.8 kg/m2) observed for 28 days and followed for the next 90 days. Weight, anthropometry, validated markers of oxidative stress (F2-isoprostane) and inflammation (C-reactive protein), adipokines, hormones, lipids, interleukins, and blood pressure were assessed at baseline, during the intervention, and at follow-up. Results Baseline median F2-isoprostane concentration (57.0, IQR = 40.5–79.5) in the CR group was 1.75-fold above average range for normal weight women (32.5 pg/ml). After starting of the caloric restriction diet, F2-isoprostane levels fell rapidly in the CR group, reaching statistical difference from the control group by day 5 (median 33.5, IQR = 26.0–48.0, P<0.001) and remained suppressed while continuing on the caloric restriction diet. Three months after resuming a habitual diet, concentrations of F2-isoprostane returned to baseline elevated levels in ∼80% of the women. Conclusions Oxidative stress can be rapidly reduced and sustained through a modest reduction in caloric intake suggesting potential health benefits in overweight and obese women. Trial Registration Clinicaltrials.gov NCT00808275

Pediatric Patients With Dyspepsia Have Chronic Symptoms, Anxiety, and Lower Quality of Life as Adolescents and Adults

BACKGROUND & AIMS Little is known about long-term health outcomes of children with dyspeptic symptoms. We studied the natural history of pediatric patients with dyspeptic symptoms, with and without histologic reflux, compared with healthy controls. METHODS We performed a prospective study of consecutive new patients, ages 8-16 years, who underwent evaluation for dyspepsia, including upper endoscopy. Patients were assigned to groups with histologic evidence of reflux esophagitis (n = 50), or normal histology results (n = 53). Healthy children were followed up as controls (n = 143). Patients and controls were evaluated 5-15 years later. They provided self-reports on severity of dyspeptic symptoms, use of acid suppression, quality of life, anxiety, and depression. RESULTS When the study began, the groups with histologic evidence of esophagitis and normal histologies did not differ in severity of dyspeptic symptoms, functional disability, or depression. After a mean 7.6-year follow-up period, each group had significantly lower quality-of-life scores and more severe dyspeptic symptoms and functional disability than controls, but did not differ significantly from each other; both groups were significantly more likely than controls to meet criteria for an anxiety disorder. At time of follow-up evaluation, use of acid-suppression medication was significantly greater in the group with histologic evidence for esophagitis, compared with patients who had normal histology findings when the study began. CONCLUSIONS Among pediatric patients with dyspepsia evaluated by endoscopy and biopsy, those with histologic evidence for esophagitis or normal histology findings are at increased risk for chronic dyspeptic symptoms, anxiety disorder, and reduced quality of life in adolescence and young adulthood.

Growth Patterns in Children with Sickle Cell Anemia during Puberty

Previous studies of children with homozygous sickle cell anemia (SCA) show impaired growth and maturation. The correlation of this suboptimal growth with metabolic and hematological factors during puberty is poorly understood.

Methods of investigating intestinal transport.

This article provides a brief overview of well-established in vivo and in vitro methods that have contributed the most to the understanding of transport processes across the gastrointestinal epithelium. In vivo perfusion techniques in humans revolve around double- and triple-lumen per oral tubes. In animals, in vivo techniques include the single and recirculation perfusion techniques and the double-isotope technique for measurement of net absorption. In vitro methods of studying intestinal transport include the everted gut sac technique, the Ussing chamber, the use of isolated epithelial cells, and the use of brush border and basolateral membranes isolated from enterocytes. The use of fluorescent probes for the measurement of intracellular ionic concentrations is a new and powerful in vivo technique that is now being applied to the gastrointestinal tract.