Search PubMed⌕ Search

Biomedical subjects

A Lama

Publications and source records attributed to A Lama.

5 recordsLinked to original sources
PubMed1991

Diaphragmatic fatigue produced by constant or modulated electric currents.

In anesthetized rabbits the efficiency of phrenic nerve stimulation with trains of electric current was studied either when ventilation was effected entirely by bilateral nerve stimulation (electrophrenic ventilation) or during unilateral nerve stimulation when animals were ventilated with a pump and open chest. Trains of rectangular electric pulses (RPT) with constant amplitude and frequency or sine waves, both the amplitude and frequency of which were modulated and controlled by a computer (MSWT), were used with each animal. MSWT closely reproduced the physiological shape of transdiaphragmatic pressure waves. Diaphragm fatigue, as determined from the decrease in the maximal relaxation rate of twitches, occurred after 20 minutes of bilateral or unilateral nerve stimulation with RPT, but only after 60 min (unilateral stimulation) or 98 min (bilateral stimulation) with MSWT. These data show the importance of the motor signal pattern in long-lasting nerve stimulation.

Animals↗
PubMed1991

[Percutaneous mitral valvuloplasty as a treatment of choice for mitral stenosis. Immediate results and long-term follow-up].

We evaluated 77 patients with symptomatic mitral stenosis for balloon valvuloplasty. Five patients were excluded from the procedure due to the presence of intra-atrial thrombi or mitral valve endocarditis as detected by 2D echocardiography. The mean age of the 72 treated patients was 38 +/- 11 years, 68 were NYHA functional class II or IV: only 6 patients had valvular calcification. Three patients had severe liver failure, 2 were chronic alcoholics, one had liver cirrhosis, 2 had severe weight loss and 13 had pulmonary hypertension at systemic levels. 69 patients had a technically adequate procedure, one patient died, 1 developed cardiac tamponade and 1 failed. Mitral valve area increased from 0.93 +/- 0.34 to 2.38 +/- 0.67 cm2. Mitral incompetence increased in only 16 patients. After a mean follow up period of 15 +/- 5 months (range 8 to 27), 56 patients remained in FC I or II. Mitral valve area remained satisfactory in 54 patients. Mitral valve anatomy evaluated by echocardiography is helpful to predict immediate and late outcome. We conclude that balloon mitral valvuloplasty is the first choice for patients with severe symptomatic mitral stenosis.

Adolescent↗
PubMed1989

[Experimental study of the pleural effects of the pulverization, under thoracoscopic control, of a fibrin glue (Tissucol)].

The instillation of a fibrin sealant (Tissucol) has been proposed in the treatment of recurrent spontaneous pneumothorax. The present work is devoted to an experimental study in the dog of the effects of this substance on the pleural cavity one and two weeks after instillation under thoracoscopic control. Its action is compared to that of placebo (methylene blue). The instillation of a placebo (n = 5) did not alter the ventilatory mechanics or the structure of the pleura. On the other hand Tissucol (n = 6) led to a fall in the thoraco-pulmonary compliance (-14%), corresponding to that of the vital capacity (-10%). In these animals, no pleural symphysis was noted, but the histological analysis gave evidence of changes in the layers of the parietal and visceral pleura: an inflammatory mononuclear reaction (71% of cases) and/or polymorphonuclear (54%), recent fibrosis (67%) and more rarely a mesothelial hyperplasia (21%). The maintenance of the integrity of the mesothelial cellular layer would explain the absence of pleural symphysis after instillation of Tissucol. These results as well as those recently obtained in the human situation prompt us to advise other methods of pleural symphysis which have been tried and tested, such as talcage or surgery.

Animals↗