Diagnosis and treatment of pulmonary arteriovenous malformations in hereditary hemorrhagic telangiectasia: An overview.

Hereditary hemorrhagic telangiectasia (HHT) or Rendu-Osler-Weber disease is an autosomic dominant disorder, which is characterized by the development of multiple arteriovenous malformations in either the skin, mucous membranes, and/or visceral organs. Pulmonary arteriovenous malformations (PAVMs) may either rupture, and lead to life-threatening hemoptysis/hemothorax or be responsible for a right-to-left shunting leading to paradoxical embolism, causing stroke or cerebral abscess. PAVMs patients should systematically be screened as the spontaneous complication rate is high, by reaching almost 50%. Neurological complications rate is considerably higher in patients presenting with diffuse pulmonary involvement. PAVM diagnosis is mainly based upon transthoracic contrast echocardiography and CT scanner examination. The latter also allows the planification of treatments to adopt, which consists of percutaneous embolization, having replaced surgery in most of the cases. The anchor technique consists of percutaneous coil embolization of the afferent pulmonary arteries of the PAVM, by firstly placing a coil into a small afferent arterial branch closely upstream the PAVM. Enhanced contrast CT scanner is the key follow-up examination that depicts the PAVM enlargement, indicating the various mechanisms of PAVM reperfusion. When performed by experienced operators as the prime treatment, percutaneous embolization of PAVMs, is a safe, efficient and sustained therapy in the great majority of HHT patients.

Periodic magnetorotational dynamo action as a prototype of nonlinear magnetic-field generation in shear flows.

The nature of dynamo action in shear flows prone to magnetohydrodynamc instabilities is investigated using the magnetorotational dynamo in Keplerian shear flow as a prototype problem. Using direct numerical simulations and Newton's method, we compute an exact time-periodic magnetorotational dynamo solution to three-dimensional dissipative incompressible magnetohydrodynamic equations with rotation and shear. We discuss the physical mechanism behind the cycle and show that it results from a combination of linear and nonlinear interactions between a large-scale axisymmetric toroidal magnetic field and nonaxisymmetric perturbations amplified by the magnetorotational instability. We demonstrate that this large-scale dynamo mechanism is overall intrinsically nonlinear and not reducible to the standard mean-field dynamo formalism. Our results therefore provide clear evidence for a generic nonlinear generation mechanism of time-dependent coherent large-scale magnetic fields in shear flows and call for new theoretical dynamo models. These findings may offer important clues to understanding the transitional and statistical properties of subcritical magnetorotational turbulence.

Endoscopy and antiplatelet agents. European Society of Gastrointestinal Endoscopy (ESGE) Guideline.

With the increasing use of antiplatelet agents (APA), their management during the periendoscopic period has become a more common and more difficult problem. The increase in use is due to the availability of new drugs and the widespread use of drug-eluting coronary stents. Acute coronary syndromes can occur when APA therapy is withheld for noncardiovascular interventions. Guidelines about APA management during the periendoscopic period are traditionally based on assessments of the procedure-related risk of bleeding and the risk of thrombosis if APA are stopped. New data allow better assessment of these risks, of the necessary duration of APA discontinuation before endoscopy, of the use of alternative procedures (mostly for endoscopic retrograde cholangiopancreatography [ERCP]), and of endoscopic methods that can be used to prevent bleeding (following colonic polypectomy). This guideline makes graded, evidence-based, recommendations for the management of APA for all currently performed endoscopic procedures. A short summary and two tables are included for quick reference.

[Place of laparoscopic radical cystectomy in the treatment of invasive bladder urothelial carcinoma]. / Place de la cystectomie radicale par voie laparoscopique dans le traitement des carcinomes urothéliaux infiltrants de vessie.

Radical cystectomy is the reference treatment for recurrent superficial or invasive bladder tumours. The most standardized incision is midline infra-umbilical laparotomy. The first laparoscopic cystectomy was performed in 1992 in a patient with neurogenic bladder and several teams have subsequently described this incision for the treatment of bladder tumours. The advantages of laparoscopy have been reported in terms of morbidity and earlier return to daily activities. The current oncological results of this incision are difficult to compare with those of conventional open surgery due to the insufficient follow-up. However, published series have not reported any significant difference in the intermediate term. Until convincing results become available, it therefore appears legitimate to allow teams skilled in laparoscopy to demonstrate the oncological efficacy of this approach. At the present time, the reference treatment for invasive bladder cancer remains open cystectomy.

[Non-gastroduodenal digestive toxicity of non-steroidal anti-inflammatory agents]. / Toxicité digestive non gastro-duodénale des anti-inflammatoires non stéroïdiens.

Recent data have confirmed that non-steroidal anti-inflammatory drugs can cause serious damage to the gastrointestinal tract involving localizations other than the well-known gastroduodenal complications. Perforation and hemorrhage of the small bowel have been reported as well as ulcerations, stenoses and diaphragm disease. The same type of lesions can occur in the large bowel in addition to ischemia and collagen colitis. Diverticular diseases of the colon can be complicated by use of non-steroidal anti-inflammatory drugs which may also trigger flare-ups of inflammatory diseases. Use in suppository form can complicate rectitis and rectal stenosis. Non-steroidal anti-inflammatory drugs apparently increase intestinal permeability by inhibiting the cyto-protective effect of prostaglandins. The exact frequency of such complications remains to be determined, but prolonged treatment in elderly subjects appears to increase risk. Current data have not shown greater or lesser toxicity for any specific drug. Non-steroidal anti-inflammatory drugs should be entertained as the cause of intestinal disorders in patients under long-term treatment.