Notion of metabolic adaptation to exercise

During muscular exercise, adenosine triphosphate (ATP) must be resynthesized in order to allow subsequent muscle contraction. ATP can be immediately resynthesized from adenosine diphosphate (ADP) and from creatine phosphate (CP). However, such resynthesis from phosphorylated compounds is not possible in very short-duration exercise. For further exercise an energy source, mainly carbohydrates and lipids, is needed. While anaerobic (glycolysis and glycogenolysis) and aerobic (mitochondrial oxidation) pathways are used for carbohydrates, lipids can only undergo oxidation. Carbohydrates are used preferentially with rising exercise intensity because of increased muscle uptake, progressive recruitment of type II fibers and catecholamine release. Lipid oxidation rises with the duration of exercise and falls with increasing intensity. The observation that training plays an important role in the use of these energy substrates has led to the development of the crossover theory by which the use of carbohydrates and lipids in all individuals depends at all times on the combined effect of training and exercise intensity. Training facilitates lipid oxidation but, by allowing higher intensity, also implies inevitable use of carbohydrates. Thus there is an exercise level, or a crossover point, at which carbohydrate energy predominates over lipid energy. Beyond this point, increasing energy requirements are satisfied by preferential use of carbohydrates. Finally, although it was incorrectly thought that proteins play a very minor role, actually amino acids coming from the voluminous tissue mass provide an important source of energy during prolonged exercise.     

Hormonal and metabolic responses to exercise across time of day and menstrual cycle phase

Two studies, each utilizing short-term treadmill exercise of a different intensity, assessed the metabolic and hormonal responses of women to exercise in the morning (AM) and late afternoon (PM). In study 1, plasma concentrations of growth hormone, arginine vasopressin, catecholamines, adrenocorticotropic hormone, cortisol, lactate, and glucose were measured before, during, and after high-intensity exercise (90% maximal O2 uptake) in the AM and PM. In study 2, plasma concentrations of adrenocorticotropic hormone, cortisol, lactate, and glucose were measured before, during, and after moderate-intensity exercise (70% maximal O2 uptake) in the AM and PM in the follicular (days 3-9), midcycle (days 10-16), and luteal (days 18-26) phases of the menstrual cycle. The results of studies 1 and 2 revealed no significant diurnal differences in the magnitude of responses for any measured variable. In addition, study 2 revealed a significant time-by-phase interaction for glucose (P = 0. 014). However, net integrated responses were similar across cycle phases. These data suggest that metabolic and hormonal responses to short-term, high-intensity exercise can be assessed with equal reliability in the AM and PM and that there are subtle differences in blood glucose responses to moderate-intensity exercise across menstrual cycle phase.     

Metabolic and hormonal mechanisms of mineral metabolic adaptation to induced hypokinetics in rats

During simulated hypokinetics, many biological functions have a tendency to stabilize at different levels with the passing of time. In this experiment, hypokinetic exposure was induced in albino rats by the suspension method for 5 weeks. A new plateau in urinary K+ excretion was attained during the third week, after a transient decrease during the first week. Since the formation of this steady plateau is considered a manifestation of the adaptation of this function, the hypokinetic exposure period was divided into a prestabilized phase and a stabilized phase. To ascertain the biochemical mechanisms of this adaptation process, the effects of aldosterone and anti-aldosterone substances (e.g., tetracycline) on K+ and Na+ excretion patterns in each phase were investigated. Decreasing aldosterone activity in the prestabilized phase and increasing activity in the stabilized phase are recognized as one of the main factors in the renal adaptation process to hypokinetics.     

Notational adaptation in children.

Three experiments examined whether and how children adapt their notations (use of external symbol systems) to the communicative needs of addresses of different ages. In Exp 1, 26 8–9 yr olds, 28 10–11 yr olds, and 11 adults made 2 notations about a solution to a simple board puzzle, one for a peer and the other for a 6-yr-old. Exp 2, with 28 8–9 yr olds, 23 10–11 yr olds, and 30 adults, focused on oral adaptations in the same context. In Exp 3, 28 8–9 yr-olds, 21 10–11 yr olds, and 30 adults were asked to choose ready-made notations for different addresses. Children's notations at both age groups were overall informative and adequate and improved with age. Children's notation's however, were not as sophisticated as verbal instructions, possible due to the Ss' more extensive experience with oral communication. Children's notational adaptation also developed with age. Some 8–9 yr olds and many 10–11 yr olds made systematic changes in their notations and verbal instructions for addresses of different ages. Most Ss of both age groups were aware of the difference in communicative competence between the younger addressee and the peer. They also shared with adults certain assumptions regarding the needs of the younger addresses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hormonal and metabolic effects of somatostatin in diabetic patients submitted to an i.v. arginine infusion

In French-speaking Quebec, implantation of behaviour therapy in psychiatric hospitals has been difficult because psychiatrists' training was and still is almost exclusively based on psychoanalytic therory. For this reason, many psychotherapists do not use the knowledge derived from laboratory experiments and only rely on their clinical judgement. Prejudiced by their professional identity, many psychiatrists believe that behaviorists manipulate and control patients, mechanize therapy, deny the importance of interpersonal relationships and only use punitive techniques. After refuting these arguments, the author describes the practical difficulties encountered when implanting behaviour therapy in a psychoanalytic milieu, as well as the advantages of a better understanding between these two schools, which might lead to psychiatry becoming more scientific, more human and closer to daily reality.     

Familial and metabolic factors related to blood pressure in Pima Indian children

High blood pressure, abnormal glucose tolerance, and obesity are frequently associated with each other, but the mechanism of these associations is poorly understood. Studying them in children may help in understanding the pathogenesis of hypertension. Blood pressure, height, weight, and plasma glucose and serum insulin concentrations during a 75-g oral glucose tolerance test were measured in 1,698 Pima Indian children aged 6-17 years who participated in an ongoing epidemiologic study. Weight relative to height was used as an index of obesity. The parents of many of the children were also examined. Fasting and 2-hour glucose and insulin concentrations, adjusted for age, sex, and relative weight, were positively related to systolic blood pressure but not to diastolic blood pressure. Relative weight, 2-hour glucose, and fasting insulin concentrations were independently and significantly associated with systolic blood pressure in a stepwise regression analysis that included age and sex. After parental hypertension was taken into account, maternal but not paternal non-insulin-dependent diabetes mellitus, controlled for the child's relative weight and glucose and insulin concentrations, was significantly associated with higher blood pressure in children. The stronger association with maternal diabetes suggests a greater sharing of environmental factors between mother and child than between father and child, but familial similarities in obesity and glucose and insulin concentrations, the diabetic intrauterine milieu, and shared environmental factors probably all contribute to this association.     

Repressive adaptation in children with cancer.

The constructs of repressive adaptive style and avoidant coping (blunting) were assessed as possible explanatory factors for previously reported findings of lower self-reported depression in children with cancer. Pediatric oncology patients 7–16 years old (n?=?107) and healthy control participants (n?=?442) completed measures of depressive symptoms, trait anxiety, defensiveness, and approach and avoidant coping. Oncology patients scored significantly lower on measures of depression and trait anxiety, and higher on defensiveness. Applying the adaptive style paradigm, the oncology group showed a significant excess of repressors. Depressive symptoms differed as a function of adaptive style, with repressors demonstrating the lowest levels of self-reported depression. Children with cancer also reported greater use of blunting, but this difference was small and appeared unrelated to depression scores. Within the cancer group, repressive adaptation was unrelated to time elapsed since diagnosis. These findings are discussed with reference to the ongoing controversy regarding cancer–personality style associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clinical and metabolic studies in children of diabetic-mothers

Children of diabetic mothers are a high-risk group. The perinatal mortality and the malformation frequency of the newborns as well as the psychosomatic, somatic and speech development during childhood until the age of 15 were statistically significantly influenced by quality of metabolic compensation, toxaemia and urinary tract infections during pregnancy. To evaluate the diabetogenic risk in children of diabetic mothers metabolic follow-up studies were performed. A statistically significant insulin-high-response without disturbed carbohydrate tolerance was seen in 25% after intravenous glucose infusion and in 28% after oral glucose load. 17% exhibited a paradoxical growth hormone reaction, while the intravenous glucose tolerance and the insulin secretion was in the normal range. Both symptoms could be early diabetic signs in children of diabetic mothers. The oGTT had pathological results in 18% and the glucose infusion test in 8%.     

Hormonal and metabolic effects of paraventricular hypothalamic administration of neuropeptide Y during rest and feeding

To investigate the role of neuropeptide Y (NPY) in the paraventricular nucleus of the hypothalamus (PVN) in the regulation of autonomic outflow, hormonal (plasma insulin and catecholamines), metabolic (blood glucose and plasma free fatty acids) and cardiovascular (heart rate and main arterial pressure) indices were measured before, during, and after bilateral infusion of NPY (1.0, 0.2, 0.04 micrograms in 1 microliter synthetic CSF) into the PVN of conscious resting rats. Administration of the highest dose (1.0 microgram/microliter) caused bradycardia and reduced circulating norepinephrine levels without effecting circulating fuels, insulin or epinephrine. In a second experiment, feeding-induced changes in hormonal and metabolic indices were assessed after NPY administration (1.0 microgram/microliter) into the PVN. During and after feeding, NPY enhanced the feeding-induced insulin response (P < 0.01) and attenuated the feeding-induced norepinephrine response (P < 0.05). The results of the present study suggest that stimulation of NPY receptors in the PVN decreases sympathetic activity and increases parasympathetic activity in resting conditions, and that these effects are potentiated during feeding.     

Salvage of urea-nitrogen in the large bowel: functional significance in metabolic control and adaptation

OBJECTIVE: To assess the safety, tolerability and efficacy of a new cyclosporin A (CyA) microemulsion formulation, Sandimmun Neoral (Neoral), in patients with severe psoriasis that was stable on CyA administered as Sandimmun (SIM). METHODS: In this 24-week, open, randomized, prospective, multicentre trial, 28 patients continued on the same dosage of SIM, while 30 converted to Neoral at 2.5 mg/kg/day or a dosage equivalent to their pre-conversion SIM dosage. During the study, dosages could be adjusted to maintain efficacy, because of adverse events or after disease stabilization. The maximum permitted dosage for either formulation was 5.0 mg/kg/day. Primary efficacy criteria were change in Psoriasis Area and Severity Index (PASI) from baseline and time to relapse. RESULTS: The dosage was increased to maintain efficacy in 22 patients (Neoral 13; SIM 9) and 20 dose reductions for safety were required (Neoral 14, SIM 6). In both groups, PASI scores remained stable throughout and relapses were primarily a result of dosage reduction after disease stabilization. No significant difference was found between groups in the proportion of patients remaining relapse-free. Adverse events were recorded in 20 patients receiving Neoral and 14 receiving SIM. Most drug-related events were of mild or moderate severity and reflected the known CyA side-effect profile. Dose titration guidelines ensured that mean blood pressure and serum creatinine concentrations remained stable in both groups. CONCLUSIONS: If the guidelines for CyA use are followed and the Neoral dosage does not exceed 5 mg/kg/day, conversion of stable patients with severe psoriasis from SIM to Neoral should present no clinically relevant safety or tolerability problems and efficacy of treatment is maintained.     

Dream content and adaptation to a stressful situation.

Conducted an investigation with 24 male undergraduates, 8 of whom were controls. 16 Ss slept in the laboratory for 3 nonconsecutive nights. On the 3rd night Ss saw a stressful film before going to sleep and again in the morning. Half of the Ss were presented with part of the sound track of the film during rapid eye movement (REM) periods at an intensity below the waking threshold (film-sound condition) while the other half were not (film-alone condition). The dreams of the Ss in the film-sound condition contained significantly more incorporations of film elements than those of Ss in the film-alone condition, suggesting that the presentation of the sound stimulus during REM periods was partially successful in enhancing the effects of the film on dreams. Contrary to expectations, Ss who exhibited more emotionality at the 2nd presentation of the film tended to be those who had more incorporations of film elements in their dreams; thus it appears that film incorporation interfered with the adaptation to stress. Finally, a group of Ss who saw the film twice, with an 8-hr waking interval, tended to be more anxious at the 2nd presentation than Ss who slept during the interval. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Family process and adaptation to children with mental retardation: Disruption and resilience in family problem-solving interactions.

Family problem-solving interactions were examined in families (N?=?165) of school-aged children with mild or moderate mental retardation (MR) and a comparison sample (N?=?52). The results demonstrated a disruptive impact of children with MR in the form of more directiveness by mothers and fathers, less supportive problem solving by single mothers, and less active problem solving by the target children in the MR group. Nevertheless, the absence of high rates of aversive behaviors in the MR group and the similarities in siblings' behaviors across the groups suggested that the MR families were also resilient in the face of special demands. Role differences among mothers, fathers, and siblings also were highly consistent in the two groups. Evidence of difficulties for single mothers and problem behaviors by other children in the family suggested that mental retardation is one of many challenges that families learn to cope with successfully. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotionality, emotion regulation, and adaptation among 5- to 8-year-old children.

This study investigated relations between emotionality, emotion regulation, and children's behavioral adaptation in a longitudinal design. Mothers rated emotionality and emotion regulation related to anger, fear, and positive emotions-exuberance for 151 children at age 5 and later at age 6 years 6 months. Emotionality and emotion regulation measures were modestly related. Preschool ratings at age 6 (n=125), maternal ratings at age 6 years 6 months (n=133), and elementary school ratings at age 8 (n=135) of problems and competence were also collected. High anger emotionality and low regulation of positive emotions and exuberance predicted externalizing problem behavior and prosocial behavior. High fear emotionality and low fear regulation predicted internalizing problem behavior. There were few interactive effects of emotionality and regulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Repressive adaptation in children with cancer: A replication and extension.

Prior research has shown a high incidence of a repressive adaptive style in children with cancer. To explore whether repressive adaptation in this population is premorbid or reactive, adaptive style was assessed longitudinally in children with cancer at the time of diagnosis and at 6 months and 1 year after diagnosis. Comparison groups included healthy children and children with other serious but nonmalignant chronic illnesses. At diagnosis, children with cancer showed a higher incidence of a repressive adaptive style than healthy children, and the incidence of repressive adaptation remained stable over time. Children with other chronic illnesses also showed levels of repressive adaptive style comparable to the cancer group. These findings suggest a shift toward repressiveness in response to the diagnosis of cancer that is then maintained over time, and demonstrate the necessity of further examination of the health consequences of adaptive style in this population. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learned aversions to proteins in rats on a dietary self-selection regimen.

101 Long-Evans and 38 Wistar rats in 4 experiments were allowed continuous access to protein and carbohydrate macronutrient sources during a sequence of cyclophosphamide (20 or 40 mg/kg, ip) injections. Significant aversions developed to the protein but not the carbohydrate source in the present experiments, in which the composition of both protein and carbohydrate diets was varied. Results suggest that Ss on a dietary self-selection regimen were more likely to develop conditioned aversions to the protein source than the carbohydrate source (Exps I, II, and III). In Exp IV, the generality of these findings was examined by determining whether aversions would selectively arise to proteins but not carbohydrates when these nutrients were conditioned in a single trial with a meal-feeding paradigm. Results show that proteins were again more salient targets for aversions than carbohydrates. Overall, findings suggest that the tendency to associate proteins with drug-induced illness more readily than carbohydrates is not limited to a self-selection regimen. The possible role of taste factors and/or postingestive effects as the basis for the differential conditioning of proteins and carbohydrates is discussed. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hostility predicts metabolic syndrome risk factors in children and adolescents.

The authors tested in 134 African American and European American children whether hostility measured at study entry predicted the metabolic syndrome risk factors an average of 3 years later. Hostility was measured with the Cook-Medley Hostility Scale (W. W. Cook & D. M. Medley, 1954) and with ratings of Potential for Hostility from interview responses. Metabolic syndrome was based on having at least 2 of the following risk factors above the 75th percentile of scores for their age, race, and gender group: body mass index, insulin resistance index, ratio of triglycerides to high-density lipoprotein cholesterol, and mean arterial blood pressure. Children who exhibited high hostility scores at baseline were likely to exhibit the metabolic syndrome at the follow-up. The results highlight the potential importance of early prevention and intervention of behavioral risk factors for cardiovascular disease. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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.