Mechanical efficiency of children with spastic cerebral palsy

In this feasibility study, the authors compared the mechanical efficiency of nine children with spastic diplegia with that of nine able-bodied children, matched for gender. They also compared resting energy expenditure in the two groups. The children with CP had significant reductions in mechanical efficiency at maximum stable work-load and marginally significant reductions when they were compared at 200 kg-m/min work-load. The efficiency of able-bodied children at 200 kg-m/min was unexpectedly reduced. There were no differences in resting energy expenditure. Mechanical efficiency may be a useful objective technique to assess the effects of interventions intended to improve the efficiency of the movement of children with CP.     

A rock in a hard place

OBJECTIVE: To determine whether cardiorespiratory endurance, a component of physical fitness, in people with cerebral palsy (CP) is lower than that in able-bodied people, and whether the difference in locomotion of CP patients affects their cardiorespiratory endurance. DESIGN: Nonrandomized control trial. SETTING: Referred care center. SUBJECTS: Twelve men with CP who were independent in daily life and 7 able-bodied control volunteers. INTERVENTION: Cardiorespiratory endurance of the subjects was measured with an arm ergometer. MAIN OUTCOME MEASURES: Oxygen consumption (VO2), heart rate (HR), and physical working capacity (PWC) measured during arm ergometer rotation. RESULTS: The 75%VO2max and 75%HRmax did not differ significantly between CP subjects and control subjects, or between ambulatory CP subjects and wheelchair-bound CP subjects. However, the PWC at 75%HRmax of the CP subjects was significantly lower than that of the control subjects. CONCLUSION: Cardiorespiratory endurance does not differ significantly between people with CP and able-bodied people. Type of locomotion does not affect cardiorespiratory endurance. However, the highest PWC performed by the CP subjects was significantly lower than that of the control subjects.     

The biomechanics of skipping gaits: a third locomotion paradigm?

Skipping, a gait children display when they are about four- to five-years-old, is revealed to be more than a behavioural peculiarity. By means of metabolic and biomechanical measurements at several speeds, the relevance of skipping is shown to extend from links between bipedal and quadrupedal locomotion (namely galloping) to understanding why it could be a gait of choice in low-gravity conditions, and to some aspects of locomotion evolution (ground reaction forces of skipping seem to originate from pushing the walking gait to unnaturally high speeds). When the time-courses of mechanical energy and the horizontal ground reaction force are considered, a different locomotion paradigm emerges, enabling us to separate, among the bouncing gaits, the trot from the gallop (quadrupeds) and running from skipping (bipeds). The simultaneous use of pendulum-like and elastic mechanisms in skipping gaits, as shown by the energy curve analysis, helps us to understand the low cost of transport of galloping quadrupeds.     

Cocontraction and phasic activity during GAIT in children with cerebral palsy

Simultaneous activity of agonist and antagonistic muscles during a task is known as cocontraction. The primary aim of the present study was to use a cocontraction index (CI) to quantify differences in EMG activity between a group of CP and control children at two different walking speeds. The secondary aim was to compare the amount of time the muscles were activated ("on" thresholds) between the groups. Seventeen subjects volunteered for the study. One group consisted of 9 (7M, 2F) children with CP (age 12.7 +/- 2.8 years, mean +/- SD). The second group consisted of 8 able-bodied controls (7M, 1F). The discontinuous submaximal treadmill walking protocol had two 4min stages at 0% gradient. Speeds selected were 3 km.h-1 and 90% of the pre-determined fastest walking speed (FWS). Two sites of CI were measured from the EMGs of tibialis anterior and soleus (leg) and vastus lateralis and hamstrings (thigh). Significantly (p < 0.05) higher CI values were noted for the CP subjects compared to the controls, irrespective of speed or cocontraction site and there was a significant (p < 0.05) increase in CI values with increased walking speed for both CP and control subjects. Phasic analyses for 5% max EMG and 10% max EMG "on" thresholds demonstrated significant (p < 0.05) main effects for group (CP subjects had a longer time period of muscle activation than controls) and speed (muscles were active longer at 90% FWS than 3 km.h-1). The precise mechanisms by which cocontraction contributes toward abnormal gait and wasted mechanical energy require further research incorporating both electromyographic and kinematic analysis.     

Effects of thermal stress during rest and exercise in the paediatric population

Thermoregulation during exposure to hot or cold environments differs between children and adults. Many physical and physiological changes occur during growth and maturation that can affect thermoregulation during rest as well as during exercise. Thus, physical as well as physiological differences between children and adults may explain the different response to thermal stress. The main physical difference between children and adults affecting thermoregulation is the much higher surface-area-to-mass ratio of children. In a warm environment this allows them to rely more on dry heat loss and less on evaporative cooling. However, in extreme conditions, hot or cold, the greater surface-area-to-mass ratio results in a higher rate of heat absorption or heat loss, respectively. The lower body fat in girls compared with women provides lower insulation and presents a disadvantage in a cold environment. The smaller blood volume in children compared with adults, even relative to body size, may limit the potential for heat transfer during heat exposure and may compromise exercise performance in the heat. The main physiological difference between children and adults is in the sweating mechanism, affecting their thermoregulation in the heat, but not in the cold. The lower sweating rate characteristic of children is due to a lower sweating rate per gland and not to a lower number of sweat glands. In fact, children are characterised by a higher density of heat-activated sweat glands. The lower sweating rate per gland may be explained by the smaller sweat gland size, a lower sensitivity of the sweating mechanism to thermal stimuli and, possibly, a lower sweat gland metabolic capacity. Other physiological differences between children and adults that may affect thermoregulation include metabolic, circulatory and hormonal disparities. The higher metabolic cost of locomotion in children provides an added strain on the thermoregulatory system during exercise in the heat. On the other hand, during acute exposure to cold it may prove advantageous by increasing heat production. Circulatory differences, such as a lower cardiac output at any given exercise intensity and the lower haemoglobin concentration in boys compared with men, are likely to increase the cardiovascular strain during exercise in the heat, although their effects in a cold environment are unknown. Finally, testosterone and prolactin are 2 hormones that differ in baseline levels between children and adults and may affect sweat gland function and sweat composition. These possible effects need to be further investigated. The effectiveness of thermoregulation is reflected by the stability of core temperature. In a thermoneutral environment, children are characterised by a similar rectal temperature and a higher skin temperature when compared with adults. The latter may reflect the higher reliance on dry heat loss compared with evaporative cooling in children. In a hot environment, children's body temperatures are higher compared with adults while walking and running but not necessarily while cycling. This may be related to the higher metabolic cost, and therefore higher heat production, in children while walking or running but not while cycling. In a cold environment, children are characterised by lower skin temperatures, reflecting greater vasoconstriction. Their metabolic heat is increased in the cold to a greater extent than that of adults, although this appears to be sufficient to maintain their body temperature during exercise but not during prolonged rest. Neither children nor adults sufficiently replace fluid loss during exercise in the heat. Nevertheless, recent studies suggest that in children, when the available beverage is flavoured and enriched with NaCl and carbohydrates, dehydration can be prevented. (ABSTRACT TRUNCATED)     

Cerebral palsy--the transition from youth to adulthood

Service provision for those with cerebral palsy (CP) becomes fragmented after adolescence. Young people with CP in two age groups, their carers and associates, were interviewed, and use of health and social services was investigated. Leisure activities were also compared with a matched control group of able-bodied young people. Use of health and social services decreased when the children with CP left school, thereby increasing the demands upon carers. Carers expressed anxieties about the provision of services, and frustration in obtaining information about help. Findings from the questionnaires showed the young people with CP in both age groups to be socially less active than the controls. Among the subjects, the older age group was socially less active than the younger age group. Communication is poor both between the agencies providing care and between the agencies and the young person or carer. There is a need to identify those with responsibility for coordinated-care planning for adolescents with CP.     

No evidence for a higher resting metabolic rate in noninstitutionalized Alzheimer's disease patients

OBJECTIVE: It has previously been suggested that Alzheimer's disease patients have higher resting energy requirements than healthy individuals, which may contribute to their unexplained weight loss. We examined whether resting metabolic rate, the largest component of daily energy expenditure, is elevated in Alzheimer's patients compared with healthy older controls. DESIGN: Cross-sectional. SETTING: General Clinical Research Center and Baltimore VA Medical Center. PATIENTS: Twenty-five noninstitutionalized demented patients (74 +/- 8 years; mean +/- SD) with a wide range of Mini-Mental Examination scores (1 to 20) and 73 healthy older individuals (69 +/- 7 years). MEASUREMENTS: Resting metabolic rate was measured by indirect calorimetry, fat-free mass and fat mass by dual energy X-ray absorptiometry, and daily energy intake by food diaries. RESULTS: No differences in fat-free mass and fat mass were noted between Alzheimer's disease patients and healthy older controls. Resting metabolic rate was similar in Alzheimer's disease patients (5446 +/- 962 kJ/day) and healthy older individuals (5647 +/- 887 kJ/day). These results persisted when resting metabolic rate was statistically adjusted for differences in body composition and age. CONCLUSION: These results provide no evidence for an elevation in resting energy requirements in noninstitutionalized demented patients.     

Adenocarcinoma in situ in cervical smears with a small cell (endometrioid) pattern: distinction from cells directly sampled from the upper endocervical canal or lower segment of the endometrium

Oxygen consumption measurements made on five repeated tests from five children with cerebral palsy (CP) and five nondisabled children of similar age and size were collected using the Cosmed K2 (Cosmed, Rome, Italy) oxygen-analysis system at free-walking velocity. Oxygen cost, oxygen consumption, and physiological cost index (PCI) were measured. There were no statistically significant differences in the percentage of variability of oxygen cost, oxygen consumption, or PCI between the disabled and nondisabled populations. Oxygen cost was the most reliable oxygen-use measurement with an average percentage of variability of 13.2% for the CP population and 13.9% for the nondisabled population. Physiological cost index was found be the least reliable measurement with the average percentages of variabilities of the disabled and nondisabled populations of 20.3 and 20.5%, respectively. Thus because of oxygen cost's relatively low variability, it was the most sensitive measurement of change in gait efficiency.     

Nutrition and physical activity program to attenuate obesity and promote physical and metabolic fitness in elementary school children

Obesity and low levels of physical and metabolic fitness are risk factors for cardiovascular disease and diabetes. The purpose of this investigation was to attenuate obesity and improve physical and metabolic fitness in elementary school children. Schools have the opportunity, mechanisms, and personnel in place to deliver nutrition education, fitness activities, and a school food service that is nutritious and healthy. Cohorts from grades 3 to 5 in two school districts in rural Nebraska (Intervention/Control) participated in a 2-year study of physical activity and modified school lunch program. Data collection for aerobic capacity, body composition, blood chemistry, nutrition knowledge, energy intake, and physical activity was at the beginning and end of each year. Int received enhanced physical activity, grade specific nutrition education, and a lower fat and sodium school lunch program. Con continued with a regular school lunch and team sports activity program. At year 2, Int lunches had significantly less energy (9%), fat (25%), sodium (21%), and more fiber (17%). However, measures of 24-hour energy intake for Int and Con showed significant differences for sodium only. Physical activity in the classroom was 6% greater for Int compared to Con (p < 0.05) but physical activity outside of school was approximately 16% less for Int compared to Con (p < 0.05). Body weight and body fat were not different between schools for normal weight or obese children. No differences were found for cholesterol, insulin, and glucose; however, HDL cholesterol was significantly greater and cholesterol/HDL was significantly less for Int compared to Con (p < 0.05). It appears that compensation in both energy intake and physical activity outside of school may be responsible for the lack of differences between Int and Con.     

Variability in energy cost and walking gait during race walking in competitive race walkers

PURPOSE: The aim of this study was to examine the variability of energy cost (Cw) and race walking gait after a 3-h walk at the competition pace in race walkers of the same performance level. METHODS: Nine competitive race walkers were studied. In the same week, after a first test of VO2max determination, each subject completed two submaximal treadmill walks (6 min length, 0% grade, 12 km X h(-1) speed) before and after a 3-h overground test completed at the individual competition speed of the race walker. During the two submaximal tests, subjects were filmed between the 2nd and the 4th min, and physiological parameters were recorded between the 4th and the 6th min. RESULTS: Results showed two trends. On the one hand, we observed a significant and systematic increase in energy cost of walking (mean deltaCw = 8.4%), whereas no variation in the gait kinematics prescribed by the rules of race walking was recorded. On the other hand, this increase in metabolic energy demand was accompanied by variations of different magnitude and direction of stride length, of the excursion of the heel and of the maximal ankle flexion at toe-off among the race walkers. CONCLUSION: These results indicated that competitive race walkers are able to maintain their walking gait with exercise duration apart from a systematic increase in energy cost. Moreover, in this form of locomotion the effect of fatigue on the gait variability seems to be an individual function of the race walk constraints and the constraints of the performer.     

Nutrition and shock in pediatric patients

Critically ill patients, including those in shock, often present with significant metabolic derangement in protein and energy metabolism characterized by: increased protein breakdown which is not suppressed by protein or energy intake; reprioritization of protein synthesis with increased synthesis of acute-phase proteins; decreased synthesis of structural proteins; and high protein turnover. In addition, there is also glucose and lipid intolerance. Adequate nutritional and metabolic support of the critically ill child under these conditions is a challenging endeavor. Traditionally, critically ill children have received nutritional requirements based on those of healthy children despite the fact that the critically ill population is physiologically and metabolically different. Furthermore, nutritional requirements in healthy children are largely based on limited data. With emerging knowledge of non-nutritional functions of nutrients, adequacy of nutritional support and requirements will eventually depend on the goals to be achieved: nutritional, physiologic, and/or pharmacologic.     

Feeding and nutritional characteristics in children with moderate or severe cerebral palsy

This study was undertaken to characterize the current feeding situation and nutritional status of moderately or severely disabled children with cerebral palsy (CP). Thirty-five children with CP (17 with diplegia, 11 with dystonia, 6 with tetraplegia and one child with ataxia) were investigated at a median age of 8 years. Information was obtained from parental interviews, medical records and clinical and anthropometric examinations. Twenty-one of the 35 children (60%), most of whom were severely disabled, were reported by the parents to have current feeding problems. Anthropometric indicators of undernutrition were found in 15 children (43%) and of overnutrition in 3 children (9%), compared with reference values of healthy children. Severely disabled children in the youngest age group were most at risk for poor nutritional status. Early identification of children at nutritional risk requires regular assessments of feeding skills and nutritional status.     

Metabolic action of neuropeptide Y in relation to its effect on feeding

Because energy homeostasis depends on a continuous balance between food intake, energy expenditure, and energy storage, it was expected that neuropeptide Y (NPY) could act not only on food intake but also on metabolic parameters. Using an original calorimetric device that allows the computation of the background metabolism (energy expenditure free from the cost of locomotor activity), we assessed the effect of a microinjection of NPY upon the quantitative (background metabolism, thermic effect of food) and qualitative (respiratory quotient) components of energy metabolism. NPY was injected into the juxtafornical hypothalamus at a dose that promotes feeding behavior (1 microg/0.5 microL) and enhances locomotor activity. Although total metabolism was increased proportionally to locomotion, no effect of NPY on background metabolism was observed when no food was available. Only following a calibrated meal given 30 min after the microinjection did NPY induce a delayed decrease in respiratory quotient whereas the postprandial background metabolism remained unaffected. In conclusion, only the new-generation calorimeters can show that the NPY-induced rise in overall metabolic rate is entirely accounted for by the unavoidable enhancement in locomotor activity and that the only metabolic effect of NPY is the delayed postprandial respiratory quotient decrease, suggesting a postabsorptive orientation toward more lipid utilization.     

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Iron and steel works is not only major energy-consuming polluters but also a major source of pollutants. The boiler of power plant should be operated under the optimal scheme to meet the varying demand and power from process to reduce cost and save energy for petrochemical industry. A multi-period mixed-integer linear programming (MILP) optimization model for the boiler load with environmental costs was established and solved by using the improved particle swarm optimization (IPSO) algorithm. The results indicate: the fuel cost is 1015611 Yuan after optimization, about 77% in the whole running system. The total cost is less than the actual cost 50462. 864 Yuan approximately, decreased by about 3. 7%, saving a lot of cost. The feasibility and rationality of the model is solved based on the IPSO method, a better operational planning is attained to provide guidance quantificationally for the operating plan. Although considering environmental costs as part of the total cost increases the total business operating costs, to resolve the issue of environmental protection and coordinated and sustainable economic and social development has important significance.     

Exposure to phenol: analysis of environmental and urinary concentrations of phenol in a group of exposed subjects

The underlying metabolism and daily energy losses were studied in 22 patients with malignant tumours of the stomach and in 51 patients with pyloric stenosis and duodenal ulcer, preoperatively and over the first 9 days postoperatively. The preoperative studies revealed a rise in the underlying metabolism rate by 43.7 and 28.2%, respectively in the patients of both groups as compared to the metabolism in healthy individuals of the same sex, weight, height and age. Postoperatively, the underlying metabolism rate dropped in the oncological patients to the level seen in healthy people, whereas in duodenal ulcer patients the metabolic rates remained elevated. The patients' energy requirements are calculated respectively as 25-30 and 41-45 kcal per 1 kg body weight daily.     

Neonatal intracranial tumor highly suspected of teratoma in the lateral ventricle consisting of multiple cysts: case report]

The role of maternal diet in the development of the fetal brain has not been adequately explored. Marine n-3 fatty acids have, however, been proposed to be important for brain development. The present case-control study aimed to investigate the relationship between dietary intake during pregnancy and the occurrence of cerebral palsy (CP) in the offspring. Children with CP (n 109), born between 1984 and 1988 to mothers residing in the Greater Athens area, were identified at any time in 1991 or 1992 through institutions delivering care and rehabilitation. Successful nutritional interviews were conducted with ninety-one of these children. Controls were chosen among the neighbours of the CP cases or were healthy siblings of children with neurological diseases other than CP, seen by the same neurologists as the children with CP. A total of 278 control children were chosen, and 246 of them were included in the nutritional study. Guardians of all children were interviewed in person on the basis of a questionnaire covering obstetric, perinatal socioeconomic and environmental variables. A validated semiquantitative food-frequency questionnaire of 111 food items was used to estimate maternal dietary intake during pregnancy. Statistical analysis was done by modelling the data through logistic regression. Food groups controlling for energy intake were alternatively and simultaneously introduced in a core model containing non-nutritional confounding variables. Consumption of cereals (mostly bread) and fish intake were inversely associated with CP (P < 0.05 and P < 0.09 respectively) whereas consumption of meat was associated with increased risk (P < 0.02). A protective effect of fish consumption and a detrimental effect of meat intake have been suggested on the basis of earlier work and appear to be biologically plausible. If corroborated by other studies, these results could contribute to our understanding of the nutritional influences on fetal brain development.     

Economic Viability of Water Pumping Systems Supplied by Wind Energy Conversion and Diesel Generator Systems in North Central Anatolia, Turkey

In this study, a comparison of the economic viability of wind turbine and diesel water pumping systems (WPSs) is presented for five different sites located in the north central Anatolia region of Turkey. A water pumping system was considered for water usage. The wind energy potential was investigated by using the time-series wind data taken from the Turkish State Meteorological Service (TSMS). Data were processed using FORTRAN computer code. The wind power and the amount of water to be pumped was evaluated using various wind energy conversion systems (WECSs), and unit energy and water cost were measured using life the cycle cost (LCC) method for these WECSs. Moreover, the cost of water to be delivered utilizing WPS with diesel generator (DG) was compared with the cost of water delivered viaWPS with WECS. Sinop had reasonable wind potential to produce electrical energy using WECS and the minimum cost of energy output and cost of water to be delivered were $0.24/kWh and $3.70/m3 in this observation station, respectively. In addition, if the water demand is lower than 1,000??m3 in Sinop, such as the water consumption of a household and farm, the WPS with WECS (for Turbines?1, 2, and 4) will be more plausible than the WPS with DG system. If a medium-scale WECS were set up in Sinop, it could supply both the annual electrical demand and water consumption of a household and farm. Finally, Sinop is going to be a marginal area for cost-effective electrical energy generation as the costs of WECSs are lowered.     

Image restrained modeling of alphaB-crystallin

Children with muscular dystrophy (MD) offer a unique opportunity to measure the effect of weakness on gait efficiency as they experience weakness not usually accompanied by other disabilities affecting gait. Oxygen consumption measurements were collected from eight patients with MD and eight patients with cerebral palsy (CP). A statistically significant difference in oxygen cost and oxygen consumption while walking between patients with CP and patients with MD was found despite their common inability to walk similar distances. Oxygen cost and oxygen consumption were elevated within the CP population, whereas all measurements for the MD population were within normal ranges. The measurements show that a patient can have normal oxygen cost and oxygen consumption while walking and yet be functionally limited because of weakness. Caution should be taken when using oxygen cost and oxygen consumption as sole outcome measures for patients with CP, because these measures may be insensitive to changes in strength.     

Endoscopic Lothrop procedure: the University of Miami experience

The aim of this study was to assess whether percentage of body fat (BF) can be predicted adequately from skinfold measurements in comparative studies of children with spastic cerebral palsy (CP) and healthy control children. The deuterium dilution technique (D2O) was used as a reference method. In contrast with what was expected, %BF predicted from skinfold measurements was considerably lower than that determined by the D2O method in children with CP, whereas in the controls this was not seen. A proportionally large internal fat deposit and a different distribution of subcutaneous fat in children with CP may be responsible for this. It was concluded that skinfold measurements are not suitable for predicting %BF in comparative studies of children with CP and control children. For evaluation of diet- or exercise-related interventions in children with CP, the use of skinfold measurements seems to be justified. However, it may be more appropriate to use skinfold thicknesses without converting them to BF.