Peripheral benzodiazepine receptor (PBR) has been implicated in the regulation of various cellular processes, including regulation of steroidogenesis,immunomodulation, porphyrin transport, heme synthesis, cell apoptosis and proliferation. Also, PBR expression levels were shown to be increased in a variety of cancers indicating its important role in cancer development. The investigation and biological evaluation of specific potent radioligands for positron emission tomography PET (Positron emission tomography) studies of PBRs are of great value as they have been associated with a variety of disease processes such as cancer, autoimmune diseases, viral infection, neurodegeneration,stress, and brain injury. More than twenty years have seen the development of radiolabelled quinoline derivaties (3-isoquinolinecarboxamide and quinoline-2-carboxamides) and some of these novel probes have been evaluated for the PET imaging of PBR. This mini review is aiming to provide a brief overview on the research on this kind of imiging probe.

OBJECTIVE:  At present, there are few materials available for esophagus reconstruction anywhere in the world. The reported survival rate in animals during the perioperative period is comparatively low. The present study assessed the feasibility of using a biotype artificial esophagus in the reconstruction of a dog's esophagus. METHODS:  In 30 mongrel dogs, a portion of the thoracic esophagus was resected and an 8 cm section of artificial esophagus was transplanted to reconstruct the organ. The survival rate, food intake and process of healing were observed. RESULTS:  Of the 30 dogs, 28 survived the peri­operative period (93.3% survival). Two dogs (6.7%) developed an anastomotic fistula; 19 dogs survived for 1 year, a survival rate of 79.2% (19/24) with the remaining six dogs were killed according to the experimental protocol. Detachment of the artificial esophagus occurred on average 28.8 days after operation and the dogs suffered from varying degrees of dysphagia 23−45 days after operation. Gradual remission occurred after 4 months. The histological study revealed that the regenerated esophagus was composed of fibrous and connective tissues and the luminal surface was covered with squamous epithelium in 3−6 months. CONCLUSION:  The transplanted artificial esophagus detached after the surrounding ‘regenerated esophagus’ had formed, and the squamous epithelium gradually covered the luminal surface. Continuous remodeling of the ‘regenerated esophagus’ gradually relieved the stenosis. Whether detachment of the implant and the postoperative stenosis can be solved is the key problem restricting the use of the biotype artificial esophagus in clinical practice.