[Diffusion of rifampicin into spongy and compact bone tissue during total hip prosthesis operation]. / Etude de la diffusion de la rifampicine dans le tissu osseux spongieux et compact au cours de prothèses totales de hanche.

Sixty eight patients received either an oral single dose of 300 mg (or 300 mg/12 h), or an oral single dose of 600 mg (or 600 mg/24 h) of rifampicin. In every case samples of serum and bone were collected 3 h, 12 h, and 24 h after the last oral dose. Rifampicin levels measured at 3 h and 12 h in cortical bone samples increased significantly with the dose of the drug. The only dose which determines activity in cortical bone at the 3rd hour was the dose of 600 mg. When the dose was increased from 300 mg/12 h to 600 mg/24 h the ratio spongious bone/serum increased from 0.19 to 0.41 at 3d h and from 0.24 to 0.29 at the 12th hour; the ratio cortical bone serum was 0.20 at the 3rd hour after a dose of 600 mg. In any case tissue levels varied in a parallel direction to serum levels and were superior in spongious bone to the MIC of S. aureus sensitive strains until 12 h after the 600 mg dose. According to these results, it appears that the best dose for treating S. aureus bone infection seems to be 600 mg/12 h.

[Segmental replacement of thoracic aorta with autologous pericardium during growth (author's transl)]. / Le remplacement de l'isthme aortique par autogreffe péricardique durant la croissance.

Surgical treatment of coarctation of the aorta in the newborn often recurs during childhood. As a means of avoiding this complication segmental replacement of the thoracic aorta with autologous pericardium was evaluated. The isthmic aorta of seven mongrel puppies was replaced by a tubular live pericardial autograft. Between 5 and 36 months (average 15) after surgery, the status of the graft was evaluated by hemodynamic, angiographic, macroscopical and histological studies. Growth of the graft was appreciated by comparing its diameter to that of the descending aorta DG/DA. No pressure gradient across the graft was noted. No significant structure of the graft was observed. The internal surface of the graft was smooth, and the wall, slightly thinner than that of the aorta showed no aneurysm. The diameter of the graft was increased (DG mean 37 %) proportionally to the increase of the aorta (DA mean 36 %). Histologically the graft was endothelialized, the wall was thickened and made up of concentric collagen fibers, live fibroblasts and muscular cells. These results show that during the first months of life, the isthmus of the aorta can be replaced by an autologous pericardial graft which will follow the growth of the normal aorta and adapt to its hemodynamic regimen.