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Biomedical subjects

L Vico

Publications and source records attributed to L Vico.

79 records · Page 5Linked to original sources

[Quantitative histological study of the bone mass and cellular activity after 120-days decubitus. Trial of preventive protocols].

Bone biopsies of iliac crests, performed at the beginning and the end of a decubitus period of 120 days, were studied in 20 healthy volunteers men. The purpose of this experiment is to simulate the bony alterations of astronauts. The bony mass of all bed-ridden patients remained constant. In strictly immobilized patients, the rate of bony mineralization is decreased and the osteoclastic resorption activity is stimulated. In bed-ridden patients subjected to preventive physical exercises, the bony formation and resorption are increased. When prevention is administered with the use of a diphosphonate, the osteoid and osteoclastic parameters are decreased. When both types of prevention are administered, the osteoid parameters and the resorption activity are decreased but less markedly than in patients treated with diphosphonate alone.

Adult↗

[Effects of weightlessness on phosphorus and calcium metabolism and bone remodeling].

Weightlessness results in negative calcium balance which can only reflect a redistribution of calcium in the body: the loss of calcium in the faeces and/or urine is constant, but an increase in urinary hydroxyproline indicating bone collagen destruction is not always detectable; moreover, a slowing down of collagen maturation may be suspected. Bone analysis by histomorphometry in animals and by indirect, non-invasive methods in man shows a decrease in bone mass. However, this bone tissue atrophy might only reflect excessive ageing of the bone during weightlessness, as suggested by slow bone formation and lack of variation in bone resorption. Since the experimental results obtained in men and animals during simulated weightlessness on earth are not strictly identical with those observed in space- flights, their validity may be questioned. Additional studies (notably histomorphometric studies) are therefore required for a better knowledge, as well as prevention, of the problems raised by human life in space.

Animals↗

A method for the automatic characterization of bone architecture in 3D mice microtomographic images.

We developed an automatic method to characterize mice bone architecture from three-dimensional (3D) microtomographic images. The distal metaphyses of the femur of mice were imaged using 3D synchrotron radiation microtomography at the European Synchrotron Radiation Facility (ID19) with a voxel size of 6.65 mum. Within each reconstructed volume, a region of interest was defined and trabecular and cortical bones were automatically separated. Then, 3D morphologic and topologic model-independent parameters quantifying the 3D bone architecture were computed in both regions. The technique was applied to study the response of the C57BL/6J@Ico strain of mice submitted to a model of bone loss by hind limb unloading produced by tail-suspension.

Animals↗