Search PubMed⌕ Search

Biomedical subjects

W Ellis

Publications and source records attributed to W Ellis.

61 records · Page 4Linked to original sources
PubMedDate not supplied

An atlas of the brain of the electric fish Apteronotus leptorhynchus.

This atlas consists of a set of six macrophotographs illustrating the important external landmarks of the apteronotid brain, as well as 54 transverse levels through the brain stained with cresyl violet. There are 150 microns between levels and the scales have 1 mm divisions (100 microns small divisions). In general the neuroanatomy of this brain is similar to that of other teleosts except that all parts known to be concerned with electroreception are greatly hypertrophied (electrosensory lateral line lobe, nucleus praeminentialis, caudal lobe of the cerebellum, torus semicircularis dorsalis, optic tectum and nucleus electrosensorius). There are other regions of this brain which are hypertrophied or which have not been described in other teleosts, but which are not known to be directly linked to the electrosensory/electromotor system; these regions are mentioned in the accompanying text.

Anatomy, Artistic↗
PubMedDate not supplied

Evoked cavernous activity: measuring penile autonomic innervation following pelvic surgery.

To assess cavernous nerve integrity, we measured evoked cavernous activity (ECA) in 16 men who underwent nerve sparing radical prostatectomy (NS group) and 11 men who underwent non-nerve-sparing surgery (non-NS group). The right median nerve was electrically stimulated and ECA was recorded with two concentric electromyography needles placed into the right and left cavernous bodies. We simultaneously recorded hand and foot sympathetic skin responses (SSRs) as controls. All subjects had recordable SSR, and all subjects following nerve-sparing radical prostatectomy had reproducible ECA. Of the 11 non-NS subjects, eight had no response, indicating interrupted corporal innervation. Three subjects had reproducible ECA, one of whom had a very late latency, suggesting residual innervation was present. The mean latencies of ECA were similar to foot SSR mean latencies (P>0.05), but not to hand SSR latencies. The non-NS group was significantly different from the NS group for the presence of ECA (P<0.001). ECA is a viable method of evaluating the autonomic innervation of the penis.

Aged↗
PubMedDate not supplied

Accelerator mass spectrometry (AMS): recent experience of its use in a clinical study and the potential future of the technique.

1. The technique of accelerator mass spectrometry (AMS) is outlined. 2. The use of AMS in an initial validation study in animals is outlined. As part of the validation of the technique, samples from the animal study were analysed by both liquid scintillation counting (LSC) and, following dilution, by AMS. The results were similar. 3. The use of AMS in support of a clinical study is described. Six healthy male human volunteers were administered 2.7 mg [14C]-GI1817771 (121 Bq; 3.3nCi) to produce an exposure to ionizing radiation of 0.06 microSv. Mass balance in recovery of administered radioactivity was achieved and information about the presence of systemically circulating metabolites was gained. 4. The future potential of the technique of AMS is discussed.

Administration, Oral↗
PubMedDate not supplied

Electrically-stimulated muscle hypertrophy in paraplegia: assessment by quantitative CT.

To identify the magnitude of muscle hypertrophy following electrically stimulated exercise in paraplegic subjects, we used quantitative CT (QCT) of the midthigh prior to and following 6 weeks of bicycle ergometry. Three patients who had suffered acute spinal cord injury were examined in this pilot investigation. Average absolute changes in muscle cross-sectional area by QCT were determined to be 10.6 cm2 (p = 0.042) at a distal site located 100 mm above the tibial plateau and 18.8 cm2 (p = 0.019) at a more proximal site (175 mm). Expressed as a percentage increase, these changes were likewise found to be significant. When the total thigh musculature was segmented into anterior and posterior regions, significant increases were observed only among the anterior muscle groups at both the distal and the proximal sites. Muscle hypertrophy as determined by standard anthropometric techniques at 200 mm above the patella was not found to be significant. We conclude that QCT is a valuable technique for discerning changes in muscle size during fitness training and that, in our population, it was capable of differentiating specific muscle compartment hypertrophy secondary to electrical stimulation.

Adult↗
PubMedDate not supplied

Functional imaging, the frontal lobes, and dementia.

A 58-year-old man developed progressive difficulty with comprehension and verbal output with dementia. Positron emission tomography with 18F 2-fluoro-2-deoxy-D-glucose demonstrated asymmetrical frontal and anterior temporal lobe loss of glucose use. Scopolamine infusion (0.3 mg) did not influence memory. Postmortem studies revealed evidence of Pick's disease, with Pick bodies, loss of somatostatin, preservation of choline acetyltransferase and immunostaining with neurofilament antibodies. Pharmacological challenge and positron imaging offer valuable means for the noninvasive assessment of dementing illness. The contributions of functional imaging to our knowledge of frontal involvement in dementing illness are reviewed.

Brain Chemistry↗
PubMedDate not supplied

Regression of effect following radial thermokeratoplasty in humans.

Radial thermokeratoplasty is a new refractive surgical technique designed to reduce hyperopia and/or astigmatism. Four patients underwent this surgery between February and March 1988 and were monitored postoperatively for the refractive effect and evidence of endothelial cell damage. Immediately following surgery, all eyes were overcorrected, but with time regression of the effect occurred. By 10 to 12 months postoperatively, only 18% of the desired effect remained. No decrease in the central endothelial cell density occurred during this time. Further investigation into the predictability and stability of results is needed to evaluate the long-term effectiveness of this technique.

Adult↗