Moderate-to-vigorous physical activity and reactivity to acute psychosocial stress in preadolescent children

OBJECTIVES

High reactivity to psychosocial stress during childhood increases the risk of future psychological and physiological disorders. The main objective of this study was to investigate associations between children's moderate-to-vigorous physical activity (MVPA) and physiological and psychological reactions to acute psychosocial stress.

DESIGN

Randomized cross-over study comparing two groups.

METHODS

After a 7-day accelerometer-based measurement of MVPA, 110 children aged 10-13 years (48 female) were categorized into a low (<30 min/d) or a high MVPA group (>60 min/d). On separate laboratory appointments, participants completed the Trier Social Stress Test for Children (TSST-C) and a non-stressful control task in randomized order. Stress reactivity was assessed from saliva cortisol, heart rate variability and self-reported anxiety.

RESULTS

In repeated measures analyses of variance, main effects of condition indicated higher stress reactivity in the TSST-C compared to control for cortisol and anxiety, with more pronounced effects in girls compared to boys. Differences in heart rate variability disappeared after controlling for confounding variables. No interactions with MVPA were found. A main effect of MVPA indicated generally lower cortisol reactivity in the high compared to the low MVPA group.

CONCLUSIONS

The TSST-C is suitable for induction of psychosocial stress in the laboratory, but sex-specific differences have to be considered. Children who met the WHO recommendations for MVPA exhibited generally lower endocrine reactivity to both laboratory tasks combined, underlining the potential role of regular physical activity in the regulation of the stress response in early developmental stages. Further studies are necessary to ascertain causal associations.

A randomized cross-over trial investigating the neurocognitive effects of acute exercise on face recognition in children with autism spectrum disorder

Difficulties in face recognition contribute to social-cognitive problems in autistic children. Evidence on behavioral interventions targeting this cognitive domain is limited. In non-autistic individuals, a single exercise session is known to elicit temporary benefits for several cognitive functions. Our study investigates whether acute aerobic exercise influences face recognition in autistic children. In a randomized order, 29 participants completed a 20-min moderately-intense cycling bout on an ergometer and a control condition. Before and after each condition, participants categorized Mooney faces and instruments during a computerized cognitive task. Simultaneously, the N170 component of event-related potentials and pupil size were recorded using electroencephalography and eyetracking, respectively. As indicated by a greater increase of reaction time in the exercise compared to the control condition, the results revealed impaired face recognition following aerobic exercise. This effect was accompanied by a lower decrease of the positive N170 amplitude and a trend towards a greater constriction of the pupil size in the exercise compared to the control condition. Our findings highlight the interplay of the physiological state and face recognition in autistic children. Exercise-induced impairments in this social-cognitive ability may be due to an interference with the learning effect that is typically seen for the structural encoding of faces.

Behavioral and neurocognitive effects of judo training on working memory capacity in children with ADHD: A randomized controlled trial

BACKGROUND

Children with Attention Deficit Hyperactivity Disorder (ADHD) face deficits in working memory capacity that often persist into adulthood. In healthy peers, exercise targeting motor skill acquisition benefits visuospatial working memory, but its potential to reduce ADHD-related deficits remains unclear. We investigated the effect of a judo training program targeting motor skills on behavioral and neurocognitive indices of working memory capacity in children with ADHD.

METHODS

Children with ADHD aged 8 to 12 years (N = 57) were randomly allocated to a judo training group and a wait-list control group. The training program encompassed 120 min of judo per week over three months. Before and after the intervention period, participants completed a bilateral Change Detection task with low and high memory load conditions and the Movement Assessment Battery for Children-2 (MABC-2). The contralateral delay activity (CDA) elicited by the cognitive task was recorded using electroencephalography.

RESULTS

Compared to the control group, the judo training group showed a higher K-score on the Change Detection task and an increased negativity of the CDA on the high load condition following the intervention, when pretest scores (and confounders) were accounted for. In contrast, no group differences were found for MABC-2 score.

CONCLUSION

In children with ADHD, judo training may complement the pharmacological treatment by increasing the effectiveness of working memory maintenance processes. On a behavioral level, this improvement is accompanied with an increased capacity to store visuospatial information.

Prevalence of classical swine fever, Aujeszky's disease and brucellosis in a population of wild boar in Switzerland

During two survey rounds of a national surveillance system for infectious diseases in wild boar in Switzerland, each lasting four months from November to February, between 2001 and 2003, 1949 blood samples and 62 tissue samples from the spleen and 50 from the reproductive organs were collected from hunted wild boar. The survey was designed so that freedom from infection could be detected with a probability of 95 per cent at a threshold prevalence of less than 1 per cent for classical swine fever and Aujeszky's disease and less than 1.5 per cent for brucellosis. There was no serological evidence of classical swine fever or Aujeszky's disease, but brucellosis due to Brucella suis biovar 2 was confirmed serologically and by bacterial isolation.

Child mortality and malaria transmission intensity in Africa

The desirability of controlling malaria transmission in the areas of highest endemicity of Plasmodium falciparum has long been debated. Most recently, it has been claimed that rates of malaria morbidity are no higher in areas of very high transmission in Africa than they are in places with lower inoculation rates. We now review the literature on the relationship of morbidity and mortality to malaria transmission intensity, and have linked published child mortality and malaria transmission rates to examine how age-specific mortality actually varies with the inoculation rate of P. falciparum.

[Clinical presentation and therapy of Mycobacterium marinum infection as seen in 12 cases]

BACKGROUND AND OBJECTIVE

Mycobacterium marinum (M.m.) is the causative pathogen of skin infections that have been called "swimming pool granulomas". An increasing number of reports that deep structures are involved in these infections was the reason for studying the clinical presentation and response of the infection to different therapeutic regimens.

PATIENTS AND METHODS

All patients (eight men, four women, age range 18-73 years) were included in whom, between january 1991 and February 1995, M.m. infection had been proven by culture. The clinical data of these patients were retrospectively obtained by standardized questionnaire.

RESULTS

The infection was limited to the skin in four of the twelve patients, deep structures only were involved in three, and five had both. Infections limited to the skin were successfully treated with sulphamethoxazole and trimethoprim or with tetracyclines, while rifampicin, alone or in combination with ethambutol, was efficacious when deep structures were involved. No surgical intervention was--or should be--performed.

CONCLUSIONS

Infections with M.m. often involve deep structures, even in the absence of the skin being involved. The term "swimming pool granuloma" is, therefore, misleading when the infection is limited to he skin. A history of a chronic and indolent course, frequent changes of doctor and striking polypharmacy in its treatment are pointers to this infection.

[Primary epiretinal gliosis (author's transl)]

Analyzing the findings of 45 patients with primary epiretinal gliosis in 51 otherwise entirely healthy eyes, the clinical features of the disease are elaborated. The disorder is characterized by the occurance of a glial membrane covering the retina in the area of the posterior pole and leading to a distorsion of the posterior pole and leading to a distorsion of the subjacent and surrounding tissues. Most frequently, the foveal region is involved, but the foveola is often spared. With increasing distance from the center the frequency of involvement decreases. Only in very rare cases the membrane extends beyond a distance of 5,5 mm from the center of the retina. The density of the membrane varies from case to case. Average visual acuity of the eyes evaluated in this study was 0,45. In no case it was worse than 0,05. The incidence of the disease increased with both increasing myopia and hyperopia. The average age of the patients was 55 years. There was no predominance of either men or women. The glia cells which compose the membrane originate from the innermost layers of the retina, from where they extend on the retinal surface through a defect in the inner limiting membrane. The reason for the formation of the defects is not yet understood. It is also unknown if the presence of such defects is absolutely necessary for the development of this condition.

[Transport of 131J-iodo-o-hippurate and 22Na out of the retroretinal space in experimental non rhegmatogenous detachment of the retina (author's transl)]

A model of an experimental arhegmatogenous retinal detachment is presented, to allow the measurement of the transport of radioactive labeled substances out of the subretinal space. Experiments were performed on 19 male cats. 131I-iodo-o-hippurate and 22Na were used as test substances. There was no significant difference between the rate of disappearance of 131I-hippurate if injected retroretinally or intravitreally. The rate of disappearance of 131I-hippurate could be slowed down by intravenous infusion of penicillin-G. The rate of disappearance of 22Na following retroretinal injection is not only slower than the rate of disappearance of 22Na injected intravitreally, but significantly slower than the rate of disappearance of 131I-hippurate. For graphic analysis ("curve peeling") of the terms embodied in the curves, more densly situated points of measurements will be necessary. Then the experimental model will serve well to analyze the components influencing the transport of labeled sodium out of the subretinal space.