Robust envelope exchange platform for oncolytic measles virus.

The use of oncolytic viruses (OV) to precisely target and eliminate tumors ('virotherapy') is a rapidly evolving therapeutic approach to treating cancer. A major obstacle in virotherapy, especially for systemic administration, is the host's immune response towards the OV. In the case of measles virus (MeV), most individuals have been immunized against this agent leading to pre-existing neutralizing antibodies that can impair OV delivery to the tumor. These antibodies predominantly target the hemagglutinin (H) and fusion (F) envelope glycoproteins displayed at the particle's surface. Here, we introduce a novel and versatile pseudotyping platform for rapid envelope exchange of oncolytic MeV that allows for engineering of chimeric viruses invulnerable to pre-existing anti-MeV antibodies. Using this system, we have successfully exchanged the MeV F and H proteins with the glycoprotein G of vesicular stomatitis virus (VSV) and the surface proteins of Newcastle disease virus (NDV) or canine distemper virus (CDV), all of which are not endemic in the general human population. While the MeV-VSV and MeV-NDV pseudotypes were non-functional, the MeV-CDV pseudotype was successfully propagated to high-titer virus stocks. This study describes the successful generation of a robust envelope exchange platform for oncolytic MeV while also highlighting its intricate pseudotyping tolerance.

[Spontaneous regression of a focal nodular hyperplasia]. / Involution spontanée d'une hyperplasie nodulaire focale.

The authors report a case of near complete regression of a focal nodular hyperplasia of the liver over a course of 10 years in a 39 year old woman. This presentation is atypical because of its imaging features (initially typically hypervascular, to eventually become a fibrous scar after undergoing a pseudo-angiomatous phase) and because of its near complete spontaneous regression.

[Multidetector CT and MRI in diseases of the gastrointestinal tract]. / Scanner multidétecteur face à l'IRM dans la pathologie du tube digestif.

UNLABELLED: With the introduction of spiral scanning then multidetector technologies, the accuracy for diagnosing digestive tract diseases with CT has been highly improved, and CT is used more and more in the evaluation of patients with suspected gastrointestinal disorders. CT is able to demonstrate both the intramural and the extramural components of the disease, and has a major role in the preoperative staging and the follow-up. Improvements of CT protocols, such as CT-enteroclysis, or multiplanar 2D and 3D post-processing, including now techniques for "virtual endoscopy", lead to discuss new indications in which CT could now compete with conventional X-rays series and videoendoscopy. This precise study of the digestive wall, the peridigestive fat, the digestive tract blood supply, may be performed by MRI, under the condition of access to high level machines and standardized protocols. MR-enteroclysis and MR-virtual colonoscopy could be performed with much lower risk for the patient, in terms of radiation dose or contrast adverse effects. Endoluminal coils should give to MR an ultra-high resolution for analysing the different layers of the gastrointestinal wall. LEARNING OBJECTIVES: to review how to perform CT and MRI protocols for digestive tract imaging, to recognize the CT and MR patterns of the main digestive tract diseases, to discuss the value, limits and role of CT and MR in digestive tract diseases, to discuss the potential role of CT and MR new technological developments for digestive tract imaging in the upcoming future. CONCLUSION: CT is nowadays a modality of choice for digestive imaging. Improvements in technologies and indications, the necessary discussion of the risks and benefits for the patient should let the radiologists consider MRI in gastrointestinal disorders as an important part of the routine activity in clinical MRI.

High resolution unenhanced computed tomography in patients with swollen legs.

PURPOSE: To evaluate the accuracy of computed tomography (CT) scan imaging in distinguishing lymphedema from deep venous thrombosis (DVT) and lipodystrophy (lipedema) in patients with swollen legs. MATERIAL AND METHODS: CT scans of the lower limbs were performed in 55 patients with 76 swollen legs (44 lymphedemas, 12 DVT and 20 lipedemas). Thirty-four normal contralateral legs were also similarly evaluated. Primary lymphedema was verified by lymphography or lymphoscintigraphy, whereas secondary lymphedema was documented by a typical clinical history. DVT was established by ultrasound Doppler imaging. The diagnosis of lipedema was made with bilateral swollen legs where lymphoscintigraphy and Doppler examination were both unremarkable. Qualitative CT analysis was based on skin thickening, subcutaneous edema accumulation with a honeycombed pattern, and muscle compartment enlargement. RESULTS: Sensitivity and specificity of CT scan for the diagnosis of lymphedema was 93 and 100%, respectively; for lipedema it was 95 and 100%, respectively; andfor DVT it was 91 and 99%, respectively. Skin thickening was found in 42 lymphedemas (95%), in 9 DVT (75%), and in 2 lipedemas (16%). Subcutaneous edema accumulation was demonstrated in 42 legs (95%) with lymphedema and in 5 (42%) with DVT but in none with lipedema. A honeycombed pattern was present only in lymphedema (18 legs or 41%); muscle enlargement was present in all patients with DVT, in no patient with lipedema, and in 4 (9%) with lymphedema. CONCLUSION: Edema accumulation is readily demonstrated with plain CT scan and is not present in lipedema. Specific CT features of the subcutaneous fat and muscle compartments allow accurate differentiation between lymphedema and DVT.