The purpose of this study is to evaluate how virtual computed tomography (CT) endoscopy may help in assessing ossicles in the middle ear. Our series consisted of 96 ears of 68 consecutive patients with conducting hearing loss. All examinations were performed with a high-resolution spiral CT using axial and direct coronal planes of the temporal bone. Perspective virtual endoscopy was processed using the virtual endoscopic software. Superstructure of the stapes was difficult to evaluate on the virtual endoscopy; however, virtual endoscopy of the middle ear provides further information on the pathological conditions including congenital anomaly, posttraumatic, and inflammatory processes.

Ear Ossicles↗

PubMedDate not supplied

Virtual CT endoscopy in determining safe surgical entrance points for paranasal mucoceles.

The goal of this work was to evaluate virtual CT endoscopy for determining safe surgical entrance points for paranasal mucoceles. Twelve mucoceles in 11 cases were scanned with helical CT, and multiplanar reconstruction (MPR) and virtual endoscopic images were obtained. After a safe surgical entrance point was determined by MPR images, the entrance point was specified on the virtual endoscopic images. The combination of virtual endoscopic images and MPR images is a suitable method for determining a safe surgical entrance point for simple mucoceles.

Endoscopy↗

PubMedDate not supplied

Functional characterization of NGF-secreting cell grafts to the acutely injured spinal cord.

Previously we reported that grafts of cells genetically modified to produce human nerve growth factor (hNGF) promoted specific and robust sprouting of spinal sensory, motor, and noradrenergic axons. In the present study we extend these investigations to assess NGF effects on corticospinal motor axons and on functional outcomes after spinal cord injury. Fibroblasts from adult rats were transduced to express human NGF; control cells were not genetically modified. Fibroblasts were then grafted to sites of midthoracic spinal cord dorsal hemisection lesions. Three months later, recipients of NGF-secreting grafts showed deficits on conditioned locomotion over a wire mesh that did not differ in extent from control-lesioned animals. On histological examination, NGF-secreting grafts elicited specific sprouting from spinal primary sensory afferent axons, local motor axons, and putative cerulospinal axons as previously reported, but no specific responses from corticospinal axons. Axons responding to NGF robustly penetrated the grafts but did not exit the grafts to extend to normal innervation territories distal to grafts. Grafted cells continued to express NGF protein through the experimental period of the study. These findings indicate that 1) spinal cord axons show directionally sensitive growth responses to neurotrophic factors, 2) growth of axons responding to a neurotrophic factor beyond an injury site and back to their natural target regions will likely require delivery of concentration gradients of neurotrophic factors toward the target, 3) corticospinal axons do not grow toward a cellular source of NGF, and 4) functional impairments are not improved by strictly local sprouting response of nonmotor systems.

Acute Disease↗