[Severe retrosacral hemorrhage without bone injury following defenestration]. / Hémorragie grave rétrosacrée sans lésion osseuse associée après défenestration.

We describe the case of original haemorrhagic shock after a 22-year-old woman suicidal jumping. The first radiological evaluation showed only a non-bleeding fracture of the first lumbar vertebra (CT-scan) and a calcaneum fracture. Pelvic ring was normal. The exploration of the abdominal system (sonographic evaluation) did not highlight any abnormality. There was no sign of haemodynamic shock and the biological results were normal. Nevertheless, three hours later, severe haemorrhagic shock appeared without organic explanation. After new research (thoracic and abdominal-pelvic CT-scan), the source of bleeding was found in the gluteal muscles without associated pelvic ring fracture. Several vascular haemorrhagic failures were found on little arteries related to the internal iliac left artery. Haemorrhagic loss was important. Radiological gluteal arteries embolisation could have been realized but finally not chosen. The haemorrhage stopped spontaneously after about 36 hours. The early diagnosis was difficult because of the vertebral fracture that constrained strict dorsal position. We could not see the important haematoma without moving the patient. We have not found any description of a severe haemorrhagic shock secondary to a single blunt gluteal muscle.

[Mechanism of bone lengthening by the Ilizarov technique]. / Le mécanisme de l'allongement osseux par la technique d'Ilizarov.

Distraction osteogenesis relies on two local factors: 1 degree mechanical stretching multiplicates the fibroblastic population; 2 degrees hypoxia, by vessel elongation and cellular compaction, induces osteogenic stress protein metabolism. Progressive return to aerobic conditions assumes permanency of the new osseous structures. The precise technical procedure of Ilizarov brings under control the osteogenic process with unprecedented human clinical results.

Analysis of thorium and its progeny by gamma ray spectrometry and alpha track methods.

Samples originating from an EU sponsored intercomparison exercise were analysed by gamma ray spectrometry (a thorium solution sample, a zircon sand sample and a thorium ore sample). An alpha track method was also used to analyse the solution sample. The detection efficiency calibration for the gamma ray spectrometry measurements on the solid samples was established using an in-house standard of thorium nitrate. A GESPECOR Monte Carlo simulation program was utilised in the analysis of the solution sample. The in-house thorium nitrate standard was also used to prepare standards for the alpha track method. The relative differences between the 232Th activity concentration values determined in these intercomparison samples and values supplied by the NPL, UK, were found to be less than 5% when determined by the gamma ray spectrometry method and less than 8% when determined by the alpha track method.

Physical exertion in simple reaction time and continuous attention of sport participants.

To investigate the effect of physical exertion on simple reaction time and continuous attention of sport participants, an experiment was conducted with 46 male university students and 12 male cyclists. The subjects were assigned to three experimental and two control groups. The subjects of the experimental groups were asked to perform, following a 5-min, period of warming up, a high intensity exercise protocol for 5 min., on a mechanically braked cycle ergometer (Group A) or a moderate intensity exercise protocol for 30 min, on the same cycle ergometer (Groups B and C). Shortly before and immediately after the physical exercise subjects of all groups were asked to perform a test of simple reaction time and continuous attention. The subjects of the control groups were asked to perform at rest both tests of the simple reaction time and the continuous attention twice, with a 10-min. and a 35-min. interval between the first and second attempts, respectively. The results did not support the notion that exercise of moderate or high intensity influences significantly the cognitive performance of aerobically trained or untrained subjects. The results are discussed in the light of the current research findings concerning exertion and human psychomotor performance.

Measurement of uranium content and its distribution in some crustacea of Mysidacea species by the fission track method.

Uranium distributions and contents in Mysidacea species were investigated in order to be subsequently correlated with some specific properties of these crustacea. The fission track micromapping technique was used in uranium distribution and content measurements. The investigated biological samples were: (1) Javanisomysis gutzui Bacescu, 1992 and (2) Mesopodopsis slabberi Van Beneden, 1861. The determined contents varied in the range of natural background values of uranium.

[Soft tissue ossification: mechanism]. / L'ossification dans les tissus mous: le mécanisme.

Three experiments: cardiac ligature, subcutaneous implantation of glass diaphragm and regenerated calcaneus tendon transplantation, produce new bone with marrow. The mechanism proceeds in two steps: 1) after trauma or local irritation, mesenchymal fibroblasts enter in division; this young population remains fibrous indefinitely; 2) those young reactive cells, submitted to local oxygen deficiency, build new substances called "stress proteins". Under anoxia, a potent stressor, transplanted new calcaneus tendon ossifies and marrow develops in its core. No immigrant cells participate in this ossicle as it is rejected in a foreign host. Ectopic ossification is an active phenomenon, young fibroblast population building its own inductor, quite different from passive osteogenesis in which inductive message is produced outside the responsive cell. Fracture repair proceeds by an osteogenic reaction from both periosteum and marrow. A third factor is delivered by the cortex: osteogenin or BMP inductor. A fourth osteogenic factor is to be considered: "autoinduction by local stress anoxia".

Influence of physical exertion on mental performance with reference to training.

The aim of this study was to assess the effect of physical exertion (treadmill) on mental performance (matching a comparison design). Nine pairs of monozygotic twins (boys aged 11 to 14 yr.) were randomly divided into two groups, one trained and one untrained, while eight boys of the same age served as a control group. The trained group underwent a specifically designed program lasting six months. The trained and untrained groups performed on the treadmill for 20 min. at a running speed intensity above their individual anaerobic thresholds. Mental performance was evaluated by analysing mean number of correct answers, time taken to reach correct answers (decision time), and wrong answers. A 3 x 2 (group x pre/posttest) analysis of variance with repeated measures on the last factor yielded no significant differences; however, significant pre- versus posttest differences on correct answers and decision times occurred among the exercised groups.