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Biomedical subjects

M J Gleeson

Publications and source records attributed to M J Gleeson.

At least 91 records · Page 5Linked to original sources
PubMed1986

The cavitron ultrasonic surgical aspirator system. An anatomical and physiological study of the effect of its use on the rat facial nerve.

The Cavitron Ultrasonic Surgical Aspirator System was used to clear the facial nerve from adjacent tissues in the rat. Acute damage to the nerve was manifest electrophysiologically by a significant decrease in amplitude of the conducted nerve action potential (P less than 0.0001) and increase in latency of the muscle action potential (P less than 0.01). Impairment of neural activity was temporary. In the majority of rats facial movements and neural activity returned to their preoperative state within 14 days. The nerves were prepared for light and transmission electron microscopy. The histopathological correlate of the documented functional impairment was disruption of the perineurium and a variable degeneration of the nerve fibres. Regeneration was evident by the end of the second postoperative week, but degenerative changes seen in some of these new fibres cast doubt on their viability.

Action Potentials↗
PubMed1985

Fibre optic guided nasal intubation--shouldn't we be the experts?

Difficult intubations are more common in otolaryngological practice than any other branch of medicine or surgery. The majority of these are predictable. It is the unexpected intubational failure, usually in a patient undergoing treatment for an unrelated problem, that results in tragedy. In this paper the indications for fibre optic guided intubation are discussed, and the technique described and illustrated in a case of pharyngeal obstruction secondary to an epiglottic cyst. It is suggested that our expertise to operate within the upper airway should be exploited to the advantage of our patients, and of our anaesthetic and surgical colleagues.

Airway Obstruction↗
PubMed1985

Post-tonsillectomy secondary haemorrhage.

This paper compares the incidence of secondary haemorrhage in post-tonsillectomy patients who were discharged 48 hours after operation (2.8%) with those discharged at 24 hours (3%). There was no significant difference between the groups. A higher incidence of secondary haemorrhage in those patients in whom diathermy was used for haemostasis rather than ligatures (P less than 0.01) supports previous studies.

Adolescent↗
PubMed1984

Voice changes following cricothyroidotomy.

Twenty-four patients underwent cricothyroidotomy at Guy's Hospital between 1977 and 1981. Of these, 13 died during admission or shortly after discharge as a result of their primary disease and three were unsuitable for further examination. The eight remaining patients were examined to assess the effect of cricothyroidotomy on the laryngeal function of voice production. Assessment was made both subjectively and objectively by laryngography. Objective findings were correlated with structural changes seen by indirect laryngoscopy. Six of the eight patients examined had both subjective and objective disturbance of voice production. We report our experience with the surgical procedure of cricothyroidotomy which, in addition to a high incidence of vocal disturbance, includes one case of subglottic stenosis secondary to granulation tissue.

Adolescent↗
PubMed1983

Clinical analysis of laryngeal trauma secondary to intubation.

A study was undertaken to analyse the effect of short-term intubation on the voice. Children were examined laryngographically both pre- and postoperatively. Changes in larynx frequency distribution following intubation were documented using the technique of electrolaryngography; the resolution of these changes was similarly recorded. The results, in comparison with the frequency distributions associated with other disease states, give insight into the nature of the damage and its effect on vocal fold vibratory patterns. The technique therefore enables objective evidence of minor degrees of laryngeal trauma to be demonstrated and differentiated.

Adolescent↗
PubMedDate not supplied

Intramuscular hemangioma of the sternomastoid muscle.

Intramuscular hemangiomas of head and neck are uncommon benign tumors. They arise most frequently in the masseter muscle and may present a diagnostic problem. The clinical presentation is usually that of a slowly enlarging intramuscular mass. The recurrence rate is high following enucleation. A case of a rapidly evolving sternomastoid hemangioma is described which presented in unusual circumstances. The angiographic appearances of this tumor were diagnostic, and the lesion was subsequently resected completely together with a cuff or normal muscle.

Adult↗
PubMedDate not supplied

Comparative in vitro encrustation studies of biomaterials in human urine.

A new dynamic in vitro human urine model was developed to compare biomaterial encrustation. The model incorporates a capacity to study seven biomaterials, a daily urine inflow of 500 ml, a reservoir capacity of 700 ml, and a turnover rate of four days. Encrustation studies performed for 2 weeks in sterile and infected (Proteus Vulgaris) urine on segmented polyether polyurethane, polyester polyurethane, silicone (Mitsui), silicone (Dow Corning), biothane, biolor 1 and biolor 11 demonstrated that biolor 11 (silicone-carbon composite) caused the least encrustation. Encrustation analysis showed brushite in the sterile model and struvite and ammonium acid urate in the infected mode I. Biolor II should have beneficial applications in catheters, stents and prosthetics which come in contact with urine.

Bacteriuria↗
PubMedDate not supplied

Human Reissner's membrane in patients with age-related normal hearing and with sensorineural hearing loss.

Morphological features of Reissner's membrane were investigated in 6 patients with age-related normal hearing (ARNH) and in 4 with sensorineural hearing loss (SNHL) stemming from various causes. The membrane consisted of an epithelium, a basement membrane and a mesothelium with melanocytes. There were two major forms of epithelial cells: flat and rounded. In all specimens, the rounded cells formed whorls, clusters, strands and bands. The bands were wider and the whorls larger in the basal turn and decreased gradually in size toward the apex. The number of melanocytes was 2-4 times higher in both the upper half of the basal turn and the lower half of the middle turn than in the rest of the turns. In specimens from patients with SNHL, whorls and clusters were both more numerous and larger, and the number of melanocytes was higher in the upper half of the middle turn and in the apical turn than that in the ARNH group. Ultrastructural examination of epithelial and mesothelial cells as well as of melanocytes showed more pronounced cellular degeneration in patients with SNHL than in those with ARNH. A possible correlation between structural alterations of Reissner's membrane and sensorineural degeneration is discussed.

Aged↗
PubMedDate not supplied

A scanning electron microscopy study of post mortem autolytic changes in the human and rat cochleas.

The use of SEM as an adjunct to TEM and electrophysiological examination of the cochlea is now well established. It has provided a relatively simple method of assessing the effect of noise, ototoxic drugs, electrical stimulation, etc. on the surface features of the organ of corti. A controlled experiment was undertaken to document the surface autolytic changes in rat cochleas by fixation at intervals up to eight hours post mortem. These were compared with human material fixed between 40 minutes and eight hours post mortem. The results complement previous light and transmission electron microscopy studies, gives insight into the optimal and acceptable fixation times for the two species and act as a guide for the interpretation of human material.

Adult↗