Fusion of a vesicle with the cell membrane opens a pore that releases transmitter to the extracellular space. The pore can either dilate fully so that the vesicle collapses completely, or close rapidly to generate 'kiss-and-run' fusion. The size of the pore determines the release rate. At synapses, the size of the fusion pore is unclear, 'kiss-and-run' remains controversial, and the ability of 'kiss-and-run' fusion to generate rapid synaptic currents is questionable. Here, by recording fusion pore kinetics during single vesicle fusion, we found both full collapse and 'kiss-and-run' fusion at calyx-type synapses. For full collapse, the initial fusion pore conductance (G(p)) was usually >375 pS and increased rapidly at > or =299 pS ms(-1). 'Kiss-and-run' fusion was seen as a brief capacitance flicker (<2 s) with G(p) >288 pS for most flickers, but within 15-288 pS for the remaining flickers. Large G(p) (>288 pS) might discharge transmitter rapidly and thereby cause rapid synaptic currents, whereas small G(p) might generate slow and small synaptic currents. These results show that 'kiss-and-run' fusion occurs at synapses and that it can generate rapid postsynaptic currents, and suggest that various fusion pore sizes help to control the kinetics and amplitude of synaptic currents.

Since the fi rst facial transplantation in 2005, 28 have been done worldwide with encouraging immunological, functional, psychological, and aesthetic outcomes. Unlike solid organ transplantation, which is potentially life-saving, facial transplantation is life-changing. This diff erence has generated ethical concerns about the exposure of otherwise young and healthy individuals to the sequelae of lifelong, high-dose, multidrug immunosuppression. Nevertheless, advances in immunomodulatory and immunosuppressive protocols, microsurgical techniques, and computer-aided surgical planning have enabled broader clinical application of this procedure to patients. Although episodes of acute skin rejection continue to pose a serious threat to face transplant recipients, all cases have been controlled with conventional immunosuppressive regimens, and no cases of chronic rejection have been reported.

Fusion of a single vesicle induces a quantal response, which is critical in determining synaptic strength. Quantal size varies at most synapses. Its underlying mechanisms are not well understood. Here, we examined five sources of variation: vesicular glutamate concentration ([Glu] v ), vesicle volume, ultrafast fusion pore closure, the postsynaptic receptor, and the location between release and the postsynaptic receptor cluster at glutamatergic, calyx of Held synapses. By averaging 2.66 million fusion events from 459 synapses, we resolved the capacitance jump evoked by single vesicle fusion. This capacitance jump, an indicator of vesicle volume, was independent of the amplitude of the miniature EPSC (mEPSC) recorded simultaneously at the same synapses. Thus, vesicle volume is not the main source of mEPSC variation. The capacitance jump was not followed by submillisecond endocytosis, excluding ultrafast endocytosis as a source of variation. Larger mEPSCs were increased to a lesser extent by presynaptic glutamate dialysis, and reduced to a lesser extent by ␥-DGG (␥-D-glutamylglycine), a competitive AMPA receptor blocker, suggesting that a higher glutamate concentration in the synaptic cleft contributes to the large size of mEPSCs. Larger mEPSCs were not accompanied by briefer rise times, inconsistent with the prediction by, and thus arguing against, the scenario that larger mEPSCs are caused by a shorter distance between the release site and the postsynaptic receptor cluster. In summary, the different amplitudes of mEPSCs were mainly attributable to release of vesicles having similar volumes, but different glutamate amounts, suggesting that [Glu] v is a main source of quantal size variation.

Background: Correction of secondary nasal deformities frequently requires cartilage to build the framework of the nose. Traditionally, autologous costal cartilage has been used because of the paucity of the septal cartilage. Because of associated donor-site complications and increased operating time, irradiated allografts have been used. These grafts have a higher rate of resorption and infection. Thus, the authors have used fresh frozen, nonirradiated, cadaveric rib cartilage as donor cartilage to avoid these shortcomings, and they present their early experience. Methods: The operative data of 50 patients who underwent secondary rhinoplasty performed by the senior author between 2014 and 2017 were analyzed. The outcomes of the rhinoplasty were evaluated by preoperative and postoperative photographs by four blinded plastic surgeons, and the results were tabulated using the Independent Rhinoplasty Outcome Score. Results: Fifty patients were followed up over an average period of 3.35 months (range, 1 to 18 months). There was only one complication (infection, 2 percent), which did not need revision surgery. There was no warping or extrusion in this cohort. Conclusions: The authors believe that fresh frozen, nonirradiated cartilage allografts are an evolving source of donor cartilage grafts for revision rhinoplasty because they are associated with lower complication rates. However, further long-term studies with an increased sample size are necessary to prove that fresh frozen cartilage grafts are better than other sources. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Although the necessity for revisions is clear, determining which revisions to safely perform and their timing and execution have not been explored. The authors address four distinct categories of revisions, including soft-tissue revision, hard-tissue mismatch, and craniofacial skeleton and dental occlusion. The authors illustrate the success of these revisions and assess their advantages, disadvantages, and relative risk.