Biomedical subjects

François Pons

Publications and source records attributed to François Pons.

7 recordsLinked to original sources

PubMed2004

Mediation of annexin 1 secretion by a probenecid-sensitive ABC-transporter in rat inflamed mucosa.

Annexin 1 is secreted by mammalian cells but lacks a leader signal sequence necessary to lead it to the classical secretory pathway via the endoplasmic reticulum. The mechanisms involved in the secretion of leaderless proteins remain uncertain. It has been suggested to involve membrane translocation via an ABC-transporter (ATP binding cassette). Using cultured inflamed mucosa from rectocolitis induced in rats, we studied if annexin 1 secretion followed the two main characteristics of ABC-transporter substrates: dependency on ATP hydrolysis and competitive inhibition by several other ABC-transporter substrates. Annexin 1 secretion is inhibited in a dose-dependent manner by two ATPase inhibitors. The inhibition reached 63.2+/-3.2%, 66.1+/-3.73% and 88.6+/-1.4% in the presence of 2mM vanadate, 0.5 and 1mM pervanadate, respectively. The efflux of calcein, a known ABC-transporter substrate, is similarly inhibited by 69.4+/-2.8% in the presence of 1mM pervanadate. Probenecid, an inhibitor of several ABC-transporters of the subfamilly ABCC or MRP (multidrug resistant associated protein), also inhibited annexin 1 secretion in a dose-dependent manner. As compared to control, 10mM probenecid reduced annexin 1 secretion by 72+/-20% and 20mM by 95.0+/-9%. By contrast, annexin 1 secretion is not blocked by other inhibitors of MRP1 (indomethacin, MK571), MRP2 (ochratoxin A1 or MK571), MRP5 (trequinsin or sulfinpyrazone) or by verapamil, cyclosporin A or glyburide. Taken together, our results show that annexin 1 secretion appears to share the efflux properties of ABC-transporter substrates.

ATP-Binding Cassette Transporters↗

PubMed2004

Thoracoscopic renal denervation for intractable autosomal dominant polycystic kidney disease-related pain.

The authors report a case of intractable autosomal dominant polycystic kidney disease-related pain associated with normal renal function, treated with renal denervation. Renal denervation was performed via a thoracoscopic approach. The good medium-term result suggests that thoracoscopic sympatho-splanchnicectomy would be an attractive procedure for pain management in autosomal polycystic kidney disease.

Chronic Disease↗

PubMed2003

Videothoracoscopic resection of neurogenic tumors of the superior sulcus using the harmonic scalpel.

Resection of neurogenic tumors located in the paravertebral sulcus carries a risk of injury to the adjacent nervous structures and also to critical intercostal arteries supplying the anterior spinal artery. To avoid such complications, we have used the Harmonic Scalpel (Ethicon Endo-Surgery, Cincinnati, OH) for the dissection of neurogenic tumors in 2 consecutive patients operated on by videothoracoscopy. The Harmonic Scalpel functions with ultrasonic energy, producing less heat than a regular electrocautery and allows a safer dissection of tumors located in the posterior mediastinum, particularly those located in the superior paravertebral sulcus.

Electrocoagulation↗

PubMed2003

Videothoracoscopic bleb excision and pleural abrasion for the treatment of primary spontaneous pneumothorax: long-term results.

BACKGROUND: The goal of this study was to evaluate the long-term efficiency of videothoracoscopic bleb excision and pleural abrasion for the treatment of primary spontaneous pneumothorax. METHODS: From July 1991 to December 1997, 182 patients with primary spontaneous pneumothorax were treated by a single technique at our institution. Seven patients had single-stage bilateral procedures and 11 other patients had staged bilateral procedures. Indications for operation were first episode with prolonged air leak, incomplete lung reexpansion, or job restrictions (n = 59), first ipsilateral recurrence (n = 57), second or third ipsilateral recurrence (n = 34), contralateral recurrence (n = 25), synchronous bilateral pneumothorax (n = 3), hemopneumothorax (n = 3), and tension pneumothorax (n = 1). All patient data were reviewed retrospectively, and 167 patients were available for late follow-up (92%). RESULTS: Mean operative time was 57 +/- 19 minutes. Conversion to thoracotomy was required in 1 patient (0.6%). Mean duration of pleural drainage was 5.8 +/- 1.2 days (range, 4 to 26 days), and mean postoperative stay was 7.7 +/- 1.6 days (range, 6 to 31 days). Postoperative complications occurred in 50 patients (27.4%), the most frequent being prolonged air leak (14.8%), and in-hospital mortality was 0%. After a mean follow-up of 93 +/- 22 months (range, 57 to 134 months; median, 84 months), five ipsilateral recurrences were noted (3%). Three recurrences occurred within 12 months of videothoracoscopy and required reoperation. Two patients had partial pneumothorax recurrence at 39 and 58 months, and were treated conservatively with chest tube insertion and tale slurry. After 1 year, 10.7% of patients complained of chronic chest pain or discomfort, although none was taking pain medication after 3 months. Most patients (89.8%) were satisfied or very satisfied of their operation. All patients had returned to sport activities within 2 years. CONCLUSIONS: Videothoracoscopic bullectomy and pleural abrasion is a reliable and safe method to treat primary spontaneous pneumothorax. Long-term recurrences occur with an acceptable rate that compares with results after limited thoracotomy. Chronic chest pain or discomfort is unpredictable and may represent a problem in a few patients.

Adolescent↗

PubMed2003

Malignant "Triton" tumor of the posterior mediastinum: prolonged survival after staged resection.

Malignant "Triton" tumor is a rare subtype of malignant peripheral nerve sheath tumor showing rhabdomyoblastic differentiation. We report the case of a 22-year-old patient who had excision of such a tumor by video-assisted thoracic surgery. He was reoperated on by thoracotomy 2 months later and received adjuvant radiation, with prolonged survival. Radical surgical excision of malignant Triton tumor followed by adjuvant radiation therapy may provide the longest survival and represent the treatment of choice.

Adult↗

PubMed2002

Traumatic extrathoracic lung herniation.

Traumatic extrathoracic lung herniation is an exceptional complication of blunt chest trauma. We report the case of a 46-year-old man who was involved in a motorcycle accident and who suffered a left clavicle fracture-dislocation associated with multiple rib fractures and massive herniation of the left upper lobe through an upper anterior chest wall defect. Immediate surgical repair through an atypical transcostal vertical thoracotomy resulted in full recovery of pulmonary function at 1 year.

Clavicle↗

PubMed2002

[An unusual mediastinal malignant tumor: thymic carcinoma].

Thymic carcinoma is a relatively rare neoplasm. Current incidence is difficult to assess. There is some controversy regarding its definition and its diagnostic criteria. We report a case of epidermoid carcinoma in a 48-year-old man located in the thymus area of the anterior mediastinum. Clinicopathological features and prognosis are reviewed.

Carcinoma, Squamous Cell↗