Urethral function after chronic cauda equina lesions in cats. I. The contribution of mechanical factors and sympathetic innervation to proximal sphincter dysfunction

We investigated the contribution of mechanical and sympathetic neural factors to proximal urethral sphincter dysfunction in the cat after chronic sacral rhizotomy. Concomitant vesicostomy prevented a decrease in the urethral pressure profile measured three months post-rhizotomy. Sympathetic influences on basal urethral perfusion pressure were the same in neurally-intact and chronic rhizotomised cats. A significant prazosin-sensitive component of basal urethral perfusion pressure remained after section of all extrinsic urethral innervation in both neurally-intact and chronic cats. Local intra-arterial 6-hydroxydopamine also abolished this component. After rhizotomy, noradrenaline content in the proximal urethra was significantly increased but there was no change in sensitivity to sympathetic stimulation. A small (5% of control) atropine-sensitive and prazosin-resistant constriction was seen only after chronic sacral rhizotomy. We conclude that a mechanical factor associated with bladder expression and not an alteration in sympathetic control is the major factor leading to diminished proximal urethral closure after vesicourethral lower motor neuron lesion. Furthermore, short adrenergic neurons have an important role in the maintenance of urethral pressure in the normal state and after lower motor neuron lesion.     

Ultrastuctural studies of the primate lateral geniculate nucleus: Morphology and spatial relationships of axon terminals arising from the retina,visual cortex (area 17), superior colliculus,parabigminal nucleus,and pretectum of Galago crassicaudatus

The electron microscopic autoradiographic tracing method has been used to examine the morphology and postsynaptic relationships of five projections (retina, cortical area 17, superior colliculus (tectal), parabigeminal nucleus, and pretectum) to the dorsal lateral geniculate nucleus of the greater bush baby galago crassicaudatus. Retinal terminals have been examined in the contralaterally innervated layer of each of the three matched pairs [parvi-(X-cell), magno- (Y--cell), and koniocellular (small, W-cell)] of geniculate layers. These terminals are large and contain pale mitochondria and round vesicles (RLPs). RLPs are presynaptic to juxtasomatic regions of parvi-and magnocellular neurons. In contrast, RLPs innervate more distal regions of konicellular neurons. Labeled cortical, tectal, and parabigeminal terminals are relatively small and contain round vesicles na dark mitochondria. Cortical terminals in each of the three representative layers are presynaptic to small diameter dendrites. No convergence of cortical and retinal terminals has been seen in any layer. Labeled tectal and parabigminal terminals are found primarily in the koniocellular layers, but the latter are also seen in all other layers. Tectal and parabigeminal terminals have been observed converging with retinal terminals on dendrites of some koniocellular neurons. Labeled pretectogeniculate terminals contain densely packed pleomorphic vesicles, dark mitochondria, and a dark cytoplasmic matric. These terminals, which are present in each of the representative layers, are presynaptic to conventional dendrites and profiles containing loosely despersed pleomorphic vesicles and a pale cytoplasmic matrix. © 1994 Wiley-Liss, Inc.     

Skin Cancer Prevention: A Time for Action

Skin cancer is the most common malignancy in the United States accounting for more than 840,000 cases and 9,400 deaths annually. It is estimated that 90% of non-melanoma skin cancers and much of melanoma incidence can be attributed to sun exposure. The evidence suggests that regular use of sunscreen (Sun Protective Factor (SPF) of 15 or higher), wearing protective, tightly woven clothing and wide brimmed hats, and avoiding sun exposure when the ultraviolet rays are strongest (between 11:00 a.m. and 3:00 p.m.) can dramatically reduce the risk of skin cancer. Interventions to promote sun-protection behaviors that target children and adults are necessary to reduce the growing incidence rate of skin cancer in the United States.MA during the time of this research     

Diverse implications of a national health crisis: A qualitative exploration of community nurses' SARS experiences.

The purpose of this study was to enhance our understanding of the influence of the SARS crisis on the work and personal lives of community nurses.A total of 941 community nurses employed in a range of health-care settings in the province of Ontario, Canada, provided qualitative information about their perceptions of the impact of SARS in their workplace and in their personal lives. Themes and subthemes from the data were organized into 2 categories: The Experience (operational, organizational, and personal narratives), and Learning from the Experience (opportunities for personal learning, professional and policy development, and insight into policy and administrative implications). The findings are discussed within a framework of the learning opportunity presented by the crisis at the local, national, and international levels. The roles of effective communication, emergency response coordination, and education are considered with respect to policy development and administrative responses to infectious disease protocol. The findings are particularly relevant at this time of heightened fear of global epidemics.     

Cost-effectiveness analysis of extended conservative therapy versus surgical intervention in the management of herniated lumbar intervertebral disc.

The management of herniated lumbar intervertebral disc for patients not responding to an initial trial of conservative therapy is generally surgical. Little is known about the effect of continued conservative therapy on patients who have not improved or have deteriorated within the first 3 months. This study assessed which form of treatment, surgical or continued conservative therapy, is more cost-effective once an adequate trial of conservative therapy has failed. The study is a retrospective chart review of 55 white male truck drivers who presented with acutely herniated nucleus pulposus between 1985 and 1989. Twenty-five patients underwent surgery, and 30 underwent continued conservative therapy after initial rehabilitation. No significant difference was found in outcome (80% good or fair in both the surgical and conservative groups) or costs ($55,000 +/- $1,000/case during a 5-year period), hence no difference in the cost-effectiveness between the two treatment modalities (each $63,000 +/- $2,000/adjusted outcome). Conservatively treated patients, however, missed significantly more work. It was concluded that, for a patient not responding to the initial trial of conservative therapy, the option to undergo continued conservative treatment should be made available.     

Terson syndrome with bilateral optic nerve sheath hemorrhage.

A 53-year-old man presented with an acute headache and mental status changes due to rupture of an anterior choroidal artery aneurysm. A preoperative CT scan demonstrated subarachnoid hemorrhage, bilateral optic nerve sheath hemorrhage, and bilateral intraocular hemorrhage. Ophthalmoscopy and B-scan ocular ultrasound disclosed vitreous hemorrhages, features consistent with Terson syndrome. This is the first CT report of Terson syndrome showing bilateral optic nerve sheath hemorrhage.