Biomedical subjects

M Letort

Publications and source records attributed to M Letort.

13 recordsLinked to original sources

PubMed2000

Embolic risk of the different stages of carotid bifurcation balloon angioplasty: an experimental study.

PURPOSE: Embolic events during carotid angioplasty are a challenging problem. This experimental study was undertaken to determine the embolic risk after each stage of carotid angioplasty procedure. METHODS: Five ex vivo carotid artery balloon angioplasties were performed on fresh carotid specimens. The carotid specimens were obtained from five patients who underwent an internal carotid artery bypass for stenosis >75%. Before the endovascular maneuvers and after each stage of the procedures, the specimens were flushed with 20 mL of saline solution. Small particulate emboli (diameter, <60 microm) were searched in all the effluents according to the Coulter technique. After this procedure, each effluent was also submitted to scanning electron microscopy. RESULTS: When the stenosis was crossed with the guidewire or the balloon catheter, the number and the mean diameter of embolic particles did not change with three plaques (CP1, CP2, and CP3) and were increased with two plaques (CP4 and CP5). The maximal size of particles was 220 microm (CP5). After balloon angioplasty, the number and the mean diameter of particles increased with CP1, CP2, and CP3. With CP4 and CP5, the number of particles decreased, but their size increased. The maximal size of particles was 1100 microm (CP4). CONCLUSION: Carotid balloon angioplasty generates embolic particles after each stage of the procedure. Techniques of prevention should then be effective from the initial step of the angioplasty procedure, and the selection of patients for carotid angioplasty remains crucial.

Angioplasty, Balloon↗

PubMed1999

Resistance of antibiotic-bonded gelatin-coated polymer meshes to Staphylococcus aureus in a rabbit subcutaneous pouch model.

This study examines the efficacy of the bonding of rifampicin, vancomycin or gentamicin to gelatin-coated knitted polymer meshes to prevent perioperative infection. Antibiotic bonding was obtained by soaking the meshes for 15 min in a solution containing 20 mg ml(-1) of rifampicin or 10 mg ml(-1) of vancomycin or gentamicin. A polymer mesh was implanted in a subcutaneous pouch in 16 rabbits: four received a rifampicin-soaked mesh, four received a vancomycin-soaked mesh, four received a gentamicin-soaked mesh, and four received an untreated mesh (control group). At the time of implantation, all the meshes were contaminated locally with 10(8) colony forming units of Staphylococcus aureus. Meshes were harvested one week later and submitted to bacterial counts. At the time of explantation, none of the antibiotic-soaked meshes were infected, whereas all the untreated meshes were infected. These results show that antibiotic soaking evidently prevents perioperative infection of gelatin-coated knitted polymer meshes in this model.

Animals↗

PubMed1997

[Cancer of the larynx in Ecuador].

A retrospective review was made of 75 cases of laryngeal cancer evaluated and treated at the Social Security Hospital of Quito (Ecuador). No exclusively supraglottic lesions were found; 67% of cases, were glottic or glottic-supraglottic. Thirty-two per cent of cases were T1 and T2 and 23% had palpable lymph nodes in neck. Most T1 and T2 tumors were treated with radiotherapy (RT) and most T3 and T4 tumors with a combination of surgery and RT. The 5 and 10-year overall survival rates were 55% and 47%, respectively. The 5-year survival rates were: 81% for T1 and T2 tumors and 36% for T3 and T4 tumors (p = 0.0008), 76% for N- and 42% for N+, 53% for well-differentiated and 58% for moderately or poorly differentiated tumors, 85% for T1 and T2 lesions treated with RT and 67% for T1 and T2 lesions treated with partial surgery, and 14% for T3 and T4 lesions treated with RT and 49% for T3 and T4 lesions treated surgically (non-significant differences).

Ecuador↗

PubMed1988

Comparative assessment of cell/substratum static adhesion using an in vitro organ culture method and computerized analysis system.

The trypsin sensitivity of chick embryo cellular layers cultivated by an in vitro organ culture method toward different biomaterials has been analysed. Monolayer cells grown on to tested samples were enzymatically dissociated in 5 min - 1 h. Cumulative cell numbers, expressed as the percentage of the totally detached cell number, were plotted versus time, thus permitting the calculation of the function. The mathematical treatment by a computerized system of this function represents the trypsin sensitivity. This value modulated by the migration cell number is the static adhesion modulated index (SAMI). The trypsin sensitivity expressed according to this index allowed the establishment of an abacus wherein several zones, A, B, C and D, define cell adhesion behaviour on different biomaterials. Scanning electron microscopy analysis performed on dissociation steps showed the selective activity of trypsin on cells toward different substrata, revealing the role of an extracellular matrix and cytoskeleton in the adhesion behaviour.

Animals↗

PubMed1971