Exercise tolerance in obese vs. lean adolescents: a systematic review and meta-analysis.

To prescribe feasible and medically safe exercise interventions for obese adolescents, it remains to be determined whether exercise tolerance is altered and whether anomalous cardiopulmonary responses during maximal exercise testing are present. Studies that examined cardiopulmonary responses to maximal exercise testing in obese adolescents were searched: cardiopulmonary exercise tests with respiratory gas exchange measurements of peak oxygen uptake (VO2peak) were performed and comparisons between obese and lean adolescents were made. Study quality was assessed using a standardized item list. By meta-analyses VO2peak, peak cycling power output (Wpeak) and peak heart rate (HRpeak) were compared between groups. Nine articles were selected (333 obese vs. 145 lean adolescents). VO2peak (L min(-1)), HRpeak and Wpeak were not different between groups (P ≥ 0.10), while a trend was found for a reduced VO2peak (mL min(-1) kg(-1) lean tissue mass) (P=0.07) in obese vs. lean adolescents. It remained uncertain whether anomalous cardiopulmonary responses occur during maximal exercise testing in obese adolescents. In conclusion, a trend was found for lowered VO2peak (mL min(-1)kg(-1) lean tissue mass) in obese vs. lean adolescents. Whether cardiopulmonary anomalies during maximal exercise testing would occur in obese adolescents remains uncertain. Studies are therefore warranted to examine the cardiopulmonary response during maximal exercise testing in obese adolescents.

Analysis of idiopathic scoliosis progression by using numerical simulation.

STUDY DESIGN: The mechanisms of idiopathic scoliosis progression were investigated through a patient-specific numerical model. OBJECTIVE: To explore the combined effect of gravity, the decrease of intervertebral discs' stiffness and the anterior spinal growth on scoliosis progression, by using a numerical simulation, to better understand mechanisms of scoliosis progression. SUMMARY OF BACKGROUND DATA: Eighteen adolescents (12 girls, 6 boys) with an average age of 10.5 years (range, 7-13) were divided into 2 groups: 12 mild scoliotic patients with thoracolumbar curves and 6 asymptomatic subjects. METHODS: Accurate 3-dimensional reconstructions of the spine were performed from biplanar radiographs. A patient-specific validated finite element model was used. Four configurations were simulated for each patient: the first configuration with the spine under gravity, the second one under gravity with a decrease of disc's mechanical stiffness, the third one under gravity with anterior vertebral growth, and the last one with combination of the 3 previous configurations. RESULTS: Gravity loads resulted mainly in a vertebral lateral deviation of the curve without axial rotation for all patients with mild scoliosis. Anterior vertebral growth with gravity induced both lateral deviation and axial rotation. This phenomenon was amplified when the mechanical properties of discs were decreased. None of these simulations initiated a scoliosis-like deformity for asymptomatic subjects. CONCLUSION: For preexisting spinal curvature, an anterior spinal growth combined with gravity and a decrease of disc's mechanical stiffness could lead to a progression of scoliosis. Biomechanical factors could be secondary after initial deformation.

Bone mineral density at the femur and lumbar spine in a population of young women treated for scoliosis in adolescence.

OBJECTIVES: To evaluate associations between scoliosis and bone mineral density. Many of the factors involved in the etiopathogenesis of idiopathic scoliosis also affect peak bone mass acquisition, which occurs primarily during puberty, a period of progression for scoliosis. METHOD: We compared 33 patients treated for scoliosis with 33 controls and looked for correlations between bone mineral density and a number of retrospectively collected parameters (e.g., duration of bracing, outcome in adulthood). RESULTS: Bone mineral density values were lower in the patients than in the controls. Among the patients, those with osteopenia wore a brace significantly longer and had more severe scoliosis in adulthood than those without osteopenia. CONCLUSIONS: These findings suggest a need for osteopenia screening and prevention in children with scoliosis, for monitoring physical activity and calcium intake during bracing, for preferring braces that allow greater mobility, and for closely monitoring the scoliosis during adulthood if osteopenia is present.

Can an osteoporotic vertebral fracture cause compression of the spinal cord or cauda equina.

A 78-year-old woman developed an osteoporotic fracture of L2 followed two months later by spinal cord compression. Imaging study findings suggested a malignancy but a biopsy showed osteonecrosis, of which there was no evidence on the imaging studies. Osteonecrosis may be the cause of neurologic compromise associated with osteoporotic vertebral fractures.

[Dog bites on the face. Apropos of 200 cases]. / Les morsures de chien au niveau de la face. A propos de 200 cas.

A series of 200 patients bitten on the face by a dog between January 1979 and December 1990 was reviewed. The aim of the study was to assess our attitude of delayed sutures and to determine the origin of the dogs, their behaviour, and the circumstances of the bites. In this series, 146/200 patients (73%) were less than 15 years old and 85/200 (43%) less than 5 years old; most adults bitten had a job at risk. The rate of infectious complications was 2.5%. There were 70% (105/150) dogs from an identifiable breed (25% (38/150) pedigree) and 30% (45/150) mongrels. In 70% of the cases the victim did not know or hardly knew the dog. The study of our series and others previously published clearly demonstrates that a dog bite must never be sutured directly. By calculating the incidence of dog bite for each particular breed in France, we conclude that, with very few exceptions, no breed is more aggressive than another. Reducing the rate of dog bites implies better knowledge of dogs and respect for some common sense rules, both on the part of children and dog owners.

Promoting effect of Roussin's red identified in pickled vegetables from Linxian China.

Roussin's red (dimethylthiotetranitrosodiiron) has been identified as a non-alkylating N-nitroso compound present in pickled vegetables from Linxian, a high risk area for oesophageal cancer in China. In vitro experiments showed that Roussin's red had no significant mutagenic and transforming activities at the doses used, but it did enhance transformation in C3H/10TI/2 cells initiated with 3-methylcholanthrene (0.1 microgram/mI) and it decreased the number of sebaceous glands and increased the epidermal thickness in short term skin tests. In this respect Roussin's red resembled 12-O-tetradecanoyl-phorbol-13-acetate and the results indicate that it may be a new naturally-occurring tumour promoter. The in vitro promoting effect of extracts of pickled vegetables that has been previously reported can be explained, at least in part, by the presence of Roussin's red. The possible role of Roussin's red in the aetiology of oesophageal cancer is discussed.