Ambulatory Movements Research Articles

Serotonin hyperinnervation and upregulated 5-HT2A receptor expression and motor-stimulating function in nigrostriatal dopamine-deficient Pitx3 mutant mice

The striatum receives serotonin (5-hydroxytryptamine, 5-HT) innervation and expresses 5-HT2A receptors (5-HT2ARs) and other 5-HT receptors, raising the possibility that the striatal 5-HT system may undergo adaptive changes after chronic severe dopamine (DA) loss and contribute to the function and dysfunction of the striatum. Here we show that in transcription factor Pitx3 gene mutant mice with a selective, severe DA loss in the dorsal striatum mimicking the DA denervation in late Parkinson's disease (PD), both the 5-HT innervation and the 5-HT2AR mRNA expression were increased in the dorsal striatum. Functionally, while having no detectable motor effect in wild type mice, the 5-HT2R agonist 2,5-dimethoxy-4-iodoamphetamine increased both the baseline and l-dopa-induced normal ambulatory and dyskinetic movements in Pitx3 mutant mice, whereas the selective 5-HT2AR blocker volinanserin had the opposite effects. These results demonstrate that Pitx3 mutant mice are a convenient and valid mouse model to study the compensatory 5-HT upregulation following the loss of the nigrostriatal DA projection and that the upregulated 5-HT2AR function in the DA deficient dorsal striatum may enhance both normal and dyskinetic movements.

Ambulatory measurement of the knee adduction moment in patients with osteoarthritis of the knee

High knee joint-loading increases the risk and progression of knee osteoarthritis (OA). Mechanical loading on the knee is reflected in the external knee adduction moment (KAdM) that can be measured during gait with laboratory-based measurement systems. However, clinical application of these systems is limited. Ambulatory movement analysis systems, including instrumented force shoes (IFS) and an inertial and magnetic measurement system (IMMS), could potentially be used to determine the KAdM in a laboratory-free setting. Promising results have been reported concerning the use of the IFS in KAdM measurements; however its application in combination with IMMS has not been studied.The objective of this study was to compare the KAdM measured with an ambulatory movement analysis system with a laboratory-based system in patients with knee OA. Gait analyses of 14 knee OA patients were performed in a gait laboratory. The KAdM was concurrently determined with two the systems: (i) Ambulatory: IFS and IMMS in combination with a linked-segment model (to obtain joint positions); (ii) Laboratory: force plate and optoelectronic marker system.Mean differences in KAdM between the ambulatory and laboratory system were not significant (maximal difference 0.20%BW⁎H in late stance, i.e. 5.6% of KAdM range, P>0.05) and below clinical relevant and hypothesized differences, showing no systematic differences at group level. Absolute differences were on average 24% of KAdM range, i.e. 0.83%BW⁎H, particularly in early and late stance. To achieve greater accuracy for clinical use, estimation of joint position via a more advanced calibrated linked-segment model should be investigated.

Comparison of thermal activity thresholds of the spider mite predators Phytoseiulus macropilis and Phytoseiulus persimilis (Acari: Phytoseiidae)

The lower and upper thermal activity thresholds of the predatory mite Phytoseiulus macropilis Banks (Acari: Phytoseiidae) were compared with those of its prey Tetranychus urticae Koch (Acari: Tetranychidae) and one of the alternative commercially available control agents for T. urticae, Phytoseiulus persimilis Athias-Henriot. Adult female P. macropilis retained ambulatory function (CTmin) and movement of appendages (chill coma) at significantly lower temperatures (8.2 and 0.4°C, respectively) than that of P. persimilis (11.1 and 3.3°C) and T. urticae (10.6 and 10.3°C). As the temperature was raised, P. macropilis ceased walking (CTmax) and entered heat coma (42.7 and 43.6°C), beyond the upper locomotory limits of P. persimilis (40.0 and 41.1°C), but before T. urticae (47.3 and 48.7°C). Walking speeds were investigated and P. persimilis was found to have significantly faster ambulation than P. macropilis and T. urticae across a range of temperatures. The lower thermal activity threshold data indicate that P. macropilis will make an effective biological control agent in temperate climates.

Altered behavioral phenotypes in soluble epoxide hydrolase knockout mice: Effects of traumatic brain injury

After traumatic brain injury (TBI), arachidonic acid (ArA) is released from damaged cell membranes and metabolized to many bioactive eicosanoids, including several epoxyeicosatrienoic acids (EETs). Soluble epoxide hydrolase (Ephx2, sEH) appears to be the predominant pathway for EET metabolism to less active dihydroxyeicosatrienoates (DHETs). Prior studies indicate that brain levels of EETs increase transiently after TBI and EETs have antiinflammatory and neuroprotective activities which may benefit the injured brain. If the net effect of increased EET levels in the injured brain is beneficial to recovery, then Ephx2 gene disruption would be expected to enhance elevated EET levels and improve recovery in the injured brain. Thus, Ephx2-KO (Ephx2−/− bred onto pure C57Bl/6 background) mice were compared to wild-type controls in a unilateral controlled cortical impact model of TBI.Before injury, animals behaved comparably in open field activity and neurologic reflexes. Interestingly, the Ephx2-KO mice showed improved motor coordination on a beam walk task, yet showed indications of defective learning in a test of working spatial memory. After surgery, brain-injured Ephx2-KO mice again had less of a deficit in the beam walk than wild-type, and the difference in latency (post−pre) showed a trend of protection for Ephx2-KO mice after TBI. Brain-injured mice showed no genotype differences in working memory. Surprisingly, sham-operated Ephx2-KO mice exhibited an injured phenotype for working memory, compared to sham-operated wild-type mice.Brain eicosanoid levels were measured using liquid chromatography with tandem mass spectrometry. Of the 20 eicosanoids evaluated, only 8,9-EET was elevated in the Ephx2-KO cerebral cortex (37d post-surgery, in both sham and injured). Tissue DHET levels were below the limit of quantification. These results reflect a significant contribution of sEH deficiency in coordination of ambulatory movements and working spatial memory in the mouse. Further investigation of differential sEH expression and EET levels at earlier time points and across other brain regions may shed light on these behavioral differences.

Examining the validity of the ActivPAL monitor in measuring posture and ambulatory movement in children

BackgroundDecreasing sedentary activities that involve prolonged sitting may be an important strategy to reduce obesity and other physical and psychosocial health problems in children. The first step to understanding the effect of sedentary activities on children’s health is to objectively assess these activities with a valid measurement tool.PurposeTo examine the validity of the ActivPAL monitor in measuring sitting/lying, standing, and walking time, transition counts and step counts in children in a laboratory setting.MethodsTwenty five healthy elementary school children (age 9.9 ± 0.3 years; BMI 18.2 ± 1.9; mean ± SD) were randomly recruited across the Auckland region, New Zealand. Children were fitted with ActivPAL monitors and observed during simulated free-living activities involving sitting/lying, standing and walking, followed by treadmill and over-ground activities at various speeds (slow, normal, fast) against video observation (criterion measure). The ActivPAL sit-to-stand and stand-to-sit transition counts and steps were also compared with video data. The accuracy of step counts measured by the ActivPAL was also compared against the New Lifestyles NL-2000 and the Yamax Digi-Walker SW-200 pedometers.ResultsWe observed a perfect correlation between the ActivPAL monitor in time spent sitting/lying, standing, and walking in simulated free-living activities with direct observation. Correlations between the ActivPAL and video observation in total numbers of sit-to-stand and stand-to-sit transitions were high (r = 0.99 ± 0.01). Unlike pedometers, the ActivPAL did not misclassify fidgeting as steps taken. Strong correlations (r = 0.88-1.00) between ActivPAL step counts and video observation in both treadmill and over-ground slow and normal walking were also observed. During treadmill and over-ground fast walking and running, the correlations were low (r = 0.21-0.46).ConclusionThe ActivPAL monitor is a valid measurement tool for assessing time spent sitting/lying, standing, and walking, sit-to-stand and stand-to-sit transition counts and step counts in slow and normal walking. The device did not measure accurately steps taken during treadmill and over-ground fast walking and running in children.

Functional movement is negatively associated with weight status and positively associated with physical activity in british primary school children.

Although prior studies have suggested that overweight and obesity in childhood are associated with poorer functional movement performance, no study appears to have examined this issue in a pediatric population. The relations between BMI, ambulatory physical activity and functional movement screen (FMS) performance were compared in 58, 10-11-year-old children. Total FMS score was significantly, negatively correlated with BMI (P = .0001) and positively related to PA (P = .029). Normal weight children scored significantly better for total FMS score compared to children classified as overweight/obese (P = .0001). Mean ± S.D. of FMS scores were 15.5 ± 2.2 and 10.6 ± 2.1 in normal weight and overweight/obese children, respectively. BMI and PA were also significant predictors of functional movement (P = .0001, Adjusted R2 = .602) with BMI and PA predicting 52.9% and 7.3% of the variance in total FMS score, respectively. The results of this study highlight that ambulatory physical activity and weight status are significant predictors of functional movement in British children. Scientists and practitioners therefore need to consider interventions which develop functional movement skills alongside physical activity and weight management strategies in children in order to reduce the risks of orthopaedic abnormality arising from suboptimal movement patterns in later life.

Physical activity, adiponectin, and cardiovascular structure and function

Physical activity (PA) may modify cardiovascular structure and function as well as insulin sensitivity and level of plasma adipokines in relation to its extent, duration, and intensity. To evaluate the associations of average daily PA and bouts of moderate-to-vigorous-intensity PA with cardiovascular and metabolic measures, 45 healthy volunteers (mean age = 42 ± 9 years) not involved in regular intensive exercise training and competitive sport activity underwent the following examinations: (1) accelerometer monitoring of ambulatory movements (average monitoring time = 6.1 ± 1.3 days); (2) complete carotid and cardiac ultrasound; (3) measurement of carotid-femoral pulse-wave velocity; (4) anthropometric measurements; (5) euglycemic hyperinsulinemic clamp; and (6) assessment of plasma levels of leptin, adiponectin, and high-sensitivity C-reactive protein (hsCRP). Average PA measured by accelerometer correlated with carotid beta-stiffness index (inversely) and with longitudinal systolic myocardial velocity (directly), independently of age, anthropometric, hemodynamic, and metabolic parameters. Subjects with periods of moderate-to-vigorous-intensity PA lasting at least 10 min (n = 28) had higher left ventricular (LV) mass index and lower plasma adiponectin, leptin, and hsCRP (P < 0.05 for all) compared with those who spent the monitoring time only in sedentary and light-intensity PA (n = 17). Minutes per day spent in moderate-to-vigorous PA correlated with LV mass index (directly) and with plasma adiponectin (inversely). Plasma adiponectin was an independent determinant of LV mass, together with body surface area, stroke volume, and systolic blood pressure (cumulative r (2) = 0.80). We conclude that in healthy subjects, average daily PA is independently related to longitudinal systolic myocardial function and to local carotid stiffness. Bouts of moderate-to-vigorous PA seem to induce LV mass increase, which may be partially related to a decrease in plasma adiponectin level.

The knee adduction moment measured with an instrumented force shoe in patients with knee osteoarthritis

The external knee adduction moment (KAdM) during gait is an important parameter in patients with knee osteoarthritis (OA). KAdM measurement is currently restricted to instruments only available in gait laboratories. However, ambulatory movement analysis technology, including instrumented force shoes (IFS) and inertial and magnetic measurement systems (IMMS), can measure kinetics and kinematics of human gait free of laboratory restrictions.The objective of this study was a quantitative validation of the accuracy of the KAdM in patients with knee OA, when estimated with an ambulatory-based method (AmbBM) versus a laboratory-based method (LabBM). AmbBM is employing the IFS and a linked-segment model, while LabBM is based on a force plate and optoelectronic marker system. Effects of ground reaction force (GRF), centre of pressure (CoP), and knee joint position measurement are evaluated separately. Twenty patients with knee OA were measured.The GRFs showed differences up to 0.22N/kg, the CoPs showed differences up to 4mm, and the medio-lateral and vertical knee position showed differences to 9mm, between AmbBM and LabBM. The GRF caused an under-estimation in KAdM in early stance. However, this effect was counteracted by differences in CoP and joint position, resulting in a net 5% over-estimation. In midstance and late stance the accuracy of the KAdM was mainly limited by use of the linked-segment model for joint position estimation, resulting in an under-estimation (midstance 6% and late stance 22%). Further improvements are needed in the estimation of joint position from segment orientation.

SIRT1 Deacetylase in SF1 Neurons Protects against Metabolic Imbalance

Chronic feeding on high-calorie diets causes obesity and type 2 diabetes mellitus (T2DM), illnesses that affect hundreds of millions. Thus, understanding the pathways protecting against diet-induced metabolic imbalance is of paramount medical importance. Here, we show that mice lacking SIRT1 in steroidogenic factor 1 (SF1) neurons are hypersensitive to dietary obesity owing to maladaptive energy expenditure. Also, mutant mice have increased susceptibility to developing dietary T2DM due to insulin resistance in skeletal muscle. Mechanistically, these aberrations arise, in part, from impaired metabolic actions of the neuropeptide orexin-A and the hormone leptin. Conversely, mice overexpressing SIRT1 in SF1 neurons are more resistant to diet-induced obesity and insulin resistance due to increased energy expenditure and enhanced skeletal muscle insulin sensitivity. Our results unveil important protective roles of SIRT1 in SF1 neurons against dietary metabolic imbalance.

1. Molecular dissection of the circulating leukocyte pool: Which leukocytes get lonely?

s from the 18th Annual PNIRS Meeting 1. Molecular dissection of the circulating leukocyte pool: Which leukocytes get lonely? S. Cole , L.C. Hawkley , J.M. Arevalo , J.T. Cacioppo b UCLA, Medicine, 11-934 Factor Building, Los Angeles, CA 90095-1678, USA University of Chicago, USA We developed a bioinformatic strategy for identifying the specific leukocyte subset responsible for any observed change in the total transcriptome of the circulating PBMC pool. Transcript Origin Analysis (TOA) quantifies the extent to which each human gene is distinctively expressed by monocytes, plasmacytoid dendritic cells, NK cells, CD4+ or CD8+ T cells, or B lymphocytes. Differentially expressed genes are then tested for over-representation of transcripts originating predominately from each cell type. After validation in 5 studies involving experimental manipulation of gene expression in isolated leukocyte subtypes (p < .01 accuracy in each), we applied TOA to determine which leukocyte subset mediates the effects of long-term subjective social isolation (loneliness) on PBMC gene expression in 93 older adults participating in the Chicago Health, Aging, and Social Relationships Study. Results showed loneliness-related genes to derive primarily from plasmacytoid dendritic cells and monocytes, and to a lesser extent, B lymphocytes (all p < .01). Those dynamics reflected per-cell changes in the expression of inducible genes (i.e., not attributable to leukocyte subset prevalence), and related more strongly to the subjective experience of loneliness than to objective social network size. Evolutionarily ancient myeloid antigen presenting cells appear to have evolved a transcriptional sensitivity to socio-environmental conditions that may allow them to shift basal gene expression profiles to counter the changing microbial threats associated with hostile vs. affine social conditions. doi:10.1016/j.bbi.2011.07.004 2. Soluble IL-6 receptors induce behavior activating effects and co-localize with gp130 in the striatum and motor cortex A. Patel, D. Zhang, E.V. Kuzhikandathil, A. Siegel, S.S. Zalcman UMDNJ-NJMS, 183 South Orange Avenue, Newark, NJ 07103, USA Increased serum levels of inflammatory cytokines are evident in schizophrenic patients. Particularly strong links between IL-6 and its soluble receptor (sIL-6R) and illness severity have been observed suggesting that this cytokine and its binding protein are involved in the disease process. However, there is no evidence that sIL-6R’s affect relevant behaviors in animal models or that they localize in relevant brain regions. Here, we discovered in male Balb/c mice, that single injections of sIL-6R’s (0–2 lg, sc) induce marked dose-dependent behavior activating effects. For example, sIL-6R’s provoked significant increases in novelty-induced horizontal and vertical ambulatory movements. Of further importance, sIL-6R’s stimulated repetitive stereotyped movements, which included, turning, jumping, intense grooming, and vertical stereotypies. Because this behavioral phenotype is associated with activation of cortico-striato-thalamo-cortico (CSTC) circuits, we determined whether sIL-6R localizes in relevant cortico-striatal structures. We discovered that peripherally injected sIL-6R’s localize within the caudate-putamen, nucleus accumbens, and motor cortex. Of further significance, sIL6R co-localizes in these regions with gp130, which is a transmembrane protein through which sIL-6R’s modulate immune cell activity. Based on these findings, we suggest that after peripheral immune cell activation, sIL-6R’s shed from the cell surface of activated monocytes (and possibly other cells), enter the brain, and modulate activity in CSTC circuits associated with repetitive stereotyped movements and that are implicated in schizophrenia and other disorders in which repetitive stereotypies are expressed. doi:10.1016/j.bbi.2011.07.005 3. Role of dopamine D1 and D2 receptors in the development and expression of IL-2-induced repetitive stereotyped movements A. Patel, E.V. Kuzhikandathil, S.S. Zalcman UMDNJ-NJ Medical School, 183 South Orange Avenue, Newark,

Energy Expenditures During Wheelchair Propulsion Derived From A Body-worn Sensor Versus Heart Rate-estimated Equations

The SenseWear™ armband has been shown to be a valid and practical tool to assess energy expenditure (EE) for upright, ambulatory adults. However, we have previously demonstrated that the SenseWear™ armband (AB) overestimated VO2 and energy expenditure compared to indirect calorimetry during different speeds and gradients of treadmill wheelchair propulsion. PURPOSE: This study compared measures of exercise energy expenditure obtained from AB-estimated versus HR-derived VO2 during outdoor, overground wheelchair propulsion. METHODS: Ten individuals with spinal cord injury (SCI) performed overground wheelchair propulsion at a "slow" pace, self-selected pace and "fast" pace over a 746±4 m outdoor test course measured by GPS. EE was estimated concurrently from HR-derived VO2 and the AB. HR-derived VO2 was calculated from each individual's HR-VO2 relationship, measured by indirect calorimetry during 14 different speeds and gradients of treadmill wheelchair propulsion. RESULTS: Across all three paces (n=30), AB and HR-derived VO2 or EE were well correlated (r=0.81, P<0.05). Although AB slightly overestimated mean EE (14.6±4.4 kJ) and VO2 (0.71±0.22 ml·min-1) compared to individually-calculated HR-derived EE (13.9±4.1 kJ) and VO2 (0.67±0.20 ml·min-1), this difference was not significant. However, correlations between AB-estimated versus HR-derived EE and VO2 were poor at the "slow" pace chosen by wheelchair users (r=0.27, P>0.05) and the highest (r=0.85, P<0.05) at their "fast" pace. CONCLUSION: This study revealed that an arm-mounted multi-sensor device developed for upright ambulatory movements adequately estimated energy expenditure compared with HR-derived measures of exercise metabolism during overground wheelchair propulsion. However, when the upper-limb movements were slowest, during the "slow" wheelchair pace, the accuracy of the AB was low, with significant overprediction of exercise EE. If the AB is to be deployed as a component of exercise prescription for SCI individuals, it is necessary to develop wheelchair-specific algorithms for the armband to enhance its accuracy of estimating energy expenditures during wheelchair exercise.

Chronic injection of pansomatostatin agonist ODT8-SST differentially modulates food intake and decreases body weight gain in lean and diet-induced obese rats

The aim of this study was to investigate the central actions of the stable pansomatostatin peptide agonist, ODT8-SST on body weight. ODT8-SST or vehicle was acutely (1μg/rat) injected or chronically infused (5μg/rat/d, 14d) intracerebroventricularly and daily food intake, body weight and composition were monitored. In lean rats, neither acute nor chronic ODT8-SST influenced daily food intake while body weight was reduced by 2.2% after acute injection and there was a 14g reduction of body weight gain after 14d compared to vehicle (p<0.01). In diet-induced obese (DIO) rats, chronic ODT8-SST increased cumulative 2-week food intake compared to vehicle (+14%, p<0.05) and also blunted body weight change (−11g, p<0.05). ODT8-SST for 14d reduced lean mass (−22g and −25g respectively, p<0.001) and total water (−19g and −22g respectively, p<0.001) in lean and DIO rats and increased fat mass in DIO (+16g, p<0.001) but not lean rats (+1g, p>0.05) compared to vehicle. In DIO rats, ODT8-SST reduced ambulatory (−27%/24h, p<0.05) and fine movements (−38%, p<0.01) which was associated with an increased positive energy balance compared to vehicle (+50g, p<0.01). Chronic central somatostatin receptor activation in lean rats reduces body weight gain and lean mass independently of food intake which is likely related to growth hormone inhibition. In DIO rats, ODT8-SST reduces lean mass but promotes food intake and fat mass, indicating differential responsiveness to somatostatin under obese conditions.

The potential reproductive, neurobehavioral and systemic effects of soluble sodium tungstate exposure in Sprague–Dawley rats

The debate on tungsten (W) is fostered by its continuous usage in military munitions. Reports demonstrate W solubilizes in soil and can migrate into drinking water supplies and, therefore, is a potential health risk to humans. This study evaluated the reproductive, systemic and neurobehavioral effects of sodium tungstate (NaW) in rats following 70 days of daily pre-and postnatal exposure via oral gavage to 5, 62.5 and 125 mg/kg/day of NaW through mating, gestation and weaning (PND 0–20). Daily administration of NaW produced no overt evidence of toxicity and had no apparent effect on mating success or offspring physical development. Distress vocalizations were elevated in F 1 offspring from the high dose group, whereas righting reflex showed unexpected sex differences where males demonstrated faster righting than females; however, the effects were not dose-dependent. Locomotor activity was affected in both low and high-dose groups of F 1 females. Low-dose group showed increased distance traveled, more time in ambulatory movements and less time in stereotypic behavior than controls or high dose animals. The high-dose group had more time in stereotypical movements than controls, and less time resting than controls and the lowest exposure group. Maternal retrieval was not affected by NaW exposure. Tungsten analysis showed a systemic distribution of NaW in both parents and offspring, with preferential uptake within the immune organs, including the femur, spleen and thymus. Histopathological evidence suggested no severe chronic injury or loss of function in these organs. However, the heart showed histological lesions, histiocytic inflammation from minimal to mild with cardiomyocyte degeneration and necrosis in several P 0 animals of 125 mg NaW dose group. The result of this study suggests that pre and postnatal exposure to NaW may produce subtle neurobehavioral effects in offspring related to motor activity and emotionality.

Integrated Solution for Physical Activity Monitoring Based on Mobile Phone and PC

ObjectivesThis study is part of the ongoing development of treatment methods for metabolic syndrome (MS) project, which involves monitoring daily physical activity. In this study, we have focused on detecting walking activity from subjects which includes many other physical activities such as standing, sitting, lying, walking, running, and falling. Specially, we implemented an integrated solution for various physical activities monitoring using a mobile phone and PC.MethodsWe put the iPod touch has built in a tri-axial accelerometer on the waist of the subjects, and measured change in acceleration signal according to change in ambulatory movement and physical activities. First, we developed of programs that are aware of step counts, velocity of walking, energy consumptions, and metabolic equivalents based on iPod. Second, we have developed the activity recognition program based on PC. iPod synchronization with PC to transmit measured data using iPhoneBrowser program. Using the implemented system, we analyzed change in acceleration signal according to the change of six activity patterns.ResultsWe compared results of the step counting algorithm with different positions. The mean accuracy across these tests was 99.6 ± 0.61%, 99.1 ± 0.87% (right waist location, right pants pocket). Moreover, six activities recognition was performed using Fuzzy c means classification algorithm recognized over 98% accuracy. In addition we developed of programs that synchronization of data between PC and iPod for long-term physical activity monitoring.ConclusionsThis study will provide evidence on using mobile phone and PC for monitoring various activities in everyday life. The next step in our system will be addition of a standard value of various physical activities in everyday life such as household duties and a health guideline how to select and plan exercise considering one's physical characteristics and condition.

Multi-model adaptation for thigh movement estimation using accelerometers

Gait analysis plays an important role in healthcare and other applications. In the situation of ambulatory thigh movement estimation using accelerometers, the major challenges are non-linearity and uncertainty of thigh motion and variations of accelerometer measurement noise. In this study, the authors propose to use multiple motion models and noise models to meet these challenges. In order to adaptively select motion models and noise models to suit the thigh motion modes, feature vectors are derived from the acceleration signal in the wavelet domain for gait phases/modes detection. Based on the detection results, the right motion models and noise models are chosen, and an unscented Kalman filter is invoked to estimate the thigh movement using the chosen models. The experimental results have shown that the proposed method can estimate thigh movement accurately.

Neonatal Exposure to Oxidants Induces Later in Life a Metabolic Response Associated to a Phenotype of Energy Deficiency in an Animal Model of Total Parenteral Nutrition

Failure to protect total parenteral nutrition (TPN) from ambient light exacerbates the generation of peroxides, which affects blood glucose and plasma triacylglyceride (TG) in neonates. Based on the concept that the origin of adult diseases can be traced back to perinatal life, it was hypothesized that neonatal exposure to peroxides may affect energy availability later in life. Three-day-old guinea pigs, fitted with a jugular catheter, were fed regular chow (sham) +/- i.v. 350 microM H2O2 (sham + H2O2) or nourished with light-protected TPN [TPN(-)L, 209 +/- 9 microM peroxides] or light-exposed TPN [TPN(+)L, 365 +/- 15 microM peroxides]. After 4 d, infusions were stopped and animals fed chow. Spontaneous ambulatory movements, fasting blood glucose, glucose tolerance, TG, hepatic activities of glucokinase, phosphofructokinase (key enzymes of glycolysis), and acetyl-CoA carboxylase (key enzymes of lipogenesis) were determined at 12-14 wk and compared by ANOVA (p < 0.05). Relative to sham, the animals from sham + H2O2, TPN(-)L and TPN(+)L groups had lower plasma TG explained for 36% by low phosphofructokinase activity; they had lower glucose tolerance, lower body weight, and lower physical activity. In conclusion, neonatal exposure to oxidant molecules such as peroxides has important consequences later in life on lipid and glucose metabolism leading to a phenotype of energy deficiency.

Central Injection of the Stable Somatostatin Analog ODT8-SST Induces a Somatostatin2 Receptor-Mediated Orexigenic Effect: Role of Neuropeptide Y and Opioid Signaling Pathways in Rats

Somatostatin and octreotide injected into the brain have been reported to modulate food intake. However, little is known regarding the underlying mechanisms. The stable oligosomatostatin analog, des-AA(1,2,4,5,12,13)-[DTrp(8)]-somatostatin (ODT8-SST), like somatostatin, binds to all five somatostatin receptors (sst(1-5)). We characterized the effects of ODT8-SST injected intracerebroventricularly (i.c.v.) on food consumption and related mechanisms of action in freely fed rats. ODT8-SST (0.3 and 1 microg per rat, i.c.v.) injected during the light or dark phase induced an early onset (within 1 h) and long-lasting (4 h) increase in food intake in nonfasted rats. By contrast, i.p. injection (0.3-3 mg/kg) or i.c.v. injection of selective sst(1) or sst(4) agonists (1 microg per rat) had no effect. The 2 h food intake response during the light phase was blocked by i.c.v. injection of a sst(2) antagonist, the neuropeptide Y (NPY) Y(1) receptor antagonist, BIBP-3226, and ip injection of the mu-opioid receptor antagonist, naloxone, and not associated with changes in plasma ghrelin levels. ODT8-SST (1 microg per rat, i.c.v.) stimulated gastric emptying of a solid meal which was also blocked by naloxone. The increased food intake was accompanied by a sustained increase in respiratory quotient, energy expenditure, and drinking as well as mu-opioid receptor-independent grooming behavior and hyperthermia, while ambulatory movements were not altered after ODT8-SST (1 microg per rat, i.c.v.). These data show that ODT8-SST acts primarily through brain sst(2) receptors to induce a long-lasting orexigenic effect that involves the activation of Y(1) and opiate-receptors, accompanied by enhanced gastric transit and energy expenditure suggesting a modulation of NPYergic and opioidergic orexigenic systems by brain sst(2) receptors.

The Effective Use of the Pedometer to Increase Walking in Postpartum African American Women

African American women have been reported to have the lowest levels of physical activity as compared to any other population. Additionally, the increased contribution of childbearing to weight gain and consequential obesity found among black women and the physically inactive lifestyle developed among these women by the 6th week postpartum period is of great concern. The benefits of regular physical activity have been well established for the general population; however, physical activity recommendations are seldom included for early postpartum care. PURPOSE: To determine if the use of the pedometer would increase walking (ambulatory movement) in African American women that are between 6 weeks and 6 months postpartum. METHOD: A sample group of 32 apparently healthy postpartum African American females (aged 18-40) that were between 6-8 weeks postpartum and met the inclusion criteria participated in this study. All participants received a Yamax SW-200 pedometer and an activity log with instructions to intentionally increase their average number of steps by at least 500 steps each week beginning from baseline for 12 weeks. RESULTS: A paired t-test analysis revealed a significant increase in daily walking activity (t (30) = -8.204, p <.001) at the end of the 12 week study. An estimate of the magnitude of the effect showed a 64% increase in the average number of steps taken per day by African American women that were between 6 weeks to 6 months postpartum. At the beginning of the study, the women reportedly averaged∼ 5347 steps/day and increased ∼3402 steps/day to an average of ∼8749 daily steps by the end of the study. The proposed indices for public health are: <5000 steps/day for sedentary, 5000-7499 steps/day for low active, 7500-9999 for somewhat active, > /= 10,000 steps/day for active and > 12, 500 steps/day for highly active adults. Based on the proposed (steps/day) indices for public health, the women in this study advanced from the "low active" classification to "somewhat active" by the end of the study. CONCLUSION: The use of the pedometer was effective in increasing walking and promoting increased physical activity, as measured by the average number of daily steps, in African American women that are between 6 weeks and 6 months postpartum.

Effect of food deprivation on the ambulatory movement of the Colorado potato beetle, Leptinotarsa decemlineata

AbstractModification of dispersal behaviour is a common response of insects to food and water deprivation. The literature suggests that different insects respond with different strategies: changing walking parameters, switching dispersal mode (walking to flight or vice versa), or changing the host searching path. The goal of this study was to add to the limited literature on the subject by investigating, whether the walking parameters of adult male Colorado potato beetles, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), change in response to food and water deprivation. Observations on the distance walked, the travel speed, and the frequency of walking bouts were carried out in laboratory arenas using motion monitoring equipment. Summer and overwintered beetles were exposed to short starvation periods (2, 4, 8, 24 h) and two ranges of long starvation periods (1, 2, 4, 8 days and 1, 2, 4, 8, 16, and 32 days). Only the longest food deprivation periods of 16 and 32 days significantly reduced the walking distance, speed, and frequency of walking bouts of summer beetles. No changes were observed with overwintered beetles. The tolerance of the beetles without access to water to the different periods of food deprivation was similar to that for beetles with water except after a starvation period of 32 days, when the travel speed of summer beetles was significantly reduced by 33%. The absence of increased walking parameters found in this study and earlier observations of increased flight frequency suggest that the strategy of summer beetles will be to change the dispersal mode from walking to flight and/or to change the walking host searching path. The same results of this study and earlier observations of a decrease in the mean frequency of daily flights suggest that the strategy of overwintered L. decemlineata, exposed to food deprivation, will be to change the host search walking path rather than the walking parameters themselves.

The development of skilled walking in the rat

The rat is an altricial species and consequently undergoes considerable postnatal development. Careful analysis of the emergence and disappearance of motor behaviours is essential to gain insight into the temporal pattern of maturation of motor system structures. This study presents a qualitative analysis of the developmental progression of skilled movement in the rat by using a skilled walking task. A new rung bridge task was used to expose rat pups to a novel environment in order to reveal their potential capabilities. Ten rat pups were filmed daily from postnatal day 7 through postnatal day 30 as they explored the rung bridge task. Discrete changes in skilled and non-skilled walking in fore- and hind-limbs were evaluated by scoring seven categories and 24 subcategories of motor behaviour, including limb flexion and extension, coordination, posture, sensorimotor responses, distal control, and tail use in rat pups. Frame-by-frame analysis of ambulatory movement revealed six distinct stages of locomotor development. The most significant transformation to mature gait patterns was found between postnatal days 15 and 19, and maturation of all motor behaviour was completed by postnatal day 27. The findings are discussed in relation to the maturation of underlying structures and their relevance to studies of brain damage.