Search PubMed⌕ Search

Biomedical subjects

J M Gill

Publications and source records attributed to J M Gill.

At least 55 records · Page 3Linked to original sources
PubMed1989

Biomechanical aspects of the repair of intertrochanteric fractures.

A two-dimensional model of a repaired intertrochanteric fracture has been proposed in order to estimate the forces transmitted by a sliding screw implant and at the fracture site. These forces have been estimated from the radiographs of 55 repairs which were previously graded as satisfactory or unsatisfactory. The unsuccessful group was found to have significantly higher fracture angles as well as increased forces and moments transmitted by the implant. The results support the view that increased loading of implant and therefore high stresses in the surrounding cancellous bone contribute to the failure of repairs.

Aged↗
PubMed1989

Twisting of the human back in forward flexion.

This paper addresses the role of torsion in the production of spinal injury and in particular the possibility of injury resulting from torsion combined with flexion. The back movement of 16 normal male subjects was measured using a non-invasive, three-dimensional measurement system for assessing spinal mobility, the opto-electronic CODA-3 scanner. Measurements were made of the ability to twist the back while standing upright and in two flexed postures. Rotational ability was shown, in general, to be increased in a flexed posture, presumed to be due to an opening of the lumbar zygapophysial joints. This suggests that twisting in a flexed posture could be a mechanism for intervertebral disc injury.

Adult↗
PubMed1989

Skin regenerated from cultured epithelial autografts on full-thickness burn wounds from 6 days to 5 years after grafting. A light, electron microscopic and immunohistochemical study.

Regeneration of skin from cultured keratinocyte autografts used in the treatment of full-thickness burn wounds was studied in 21 pediatric patients from 6 days to 5 years after grafting. Findings were compared both to controls of age- and site-matched normal skin and to controls for epithelial wound-healing, re-epithelialized interstices of meshed split-thickness skin grafts of comparable postgrafting age. Six days after transplantation, a mildly hypertrophic, flat epidermis with all normal strata had regenerated, and the process of de novo dermal-epidermal junction formation had begun. Hemidesmosomes, basal lamina, and anchoring fibrils reformed conjointly in punctate fashion along the attachment face of the grafts. Within 3 to 4 weeks, the dermal-epidermal junction was complete, but full maturation of anchoring fibrils required more than a year. The process was comparable to that observed in meshed graft interstices. Rete ridges regenerated from 6 weeks to 1 year after grafting. The subjacent connective tissue initially healed to form normal scar, but it remodeled dramatically, regenerated elastin, and resembled a true dermis within 4 to 5 years. Meshed-graft interstice controls showed no rete ridge regeneration, subepithelial connective tissue remodeling, or elastin production up to 5 years after grafting. Langerhans cells repopulated grafts within 1 week, and normal population densities were reached within 2 to 6 months. After 1 year, Langerhans cell densities were increased compared with normal skin but were lower than those in age-matched meshed graft controls. Melanocytes were present in cultures at the time of transplantation, but functional epidermal melanin units were not seen in groin- or axilla-derived grafts for 6 to 8 weeks or in sole-derived epidermis until a year or more after transplantation. Normal histologic features were maintained for years after grafting. Transitory pathologic changes including parakeratosis, dyskeratosis, and intraepithelial friction blister formation were infrequently observed. No dysplastic or premalignant changes were seen.

Adolescent↗
PubMed1988

An outbreak of post-vaccinal suspected distemper-like encephalitis in farmed ferrets (Mustela putorius furo).

Two outbreaks of an encephalitis apparently induced by an attenuated live distemper vaccine occurred in a large ferret breeding establishment in New Zealand. Approximately 350 of 6,000 young ferrets 16-22 weeks old died. Many were found dead with no premonitory signs, others showed severe neurological signs. Some with central nervous system (C.N.S.) signs recovered. Pathological examination showed no gross abnormalities except for a few with mild conjunctivitis, rhinitis and lung emphysema. Microscopically there was a moderate to massive non-inflammatory necrosis of hippocampal nerve cell bodies. In those animals which survived for several days with CNS signs there was also a mild to moderately severe non-supportive encephalitis, and in some of these distinct neuronal intranuclear and intracytoplasmic eosinophilic inclusion bodies were seen. Some ferrets also had a bronchiolitis with intracytoplasmic eosinophilic inclusion bodies in bronchiolar epithelium. All these lesions suggest that a distemper like condition was involved. About half of the ferrets also had a mild to severe inflammatory myocardial necrosis.

Journal Article↗
PubMed1987

Dynamic back movement measured using a three-dimensional television system.

A technique for the measurement of rotational human back movements in three dimensions has been developed. The spatial coordinates of reflective markers on rigs attached to the back surface were calculated using a calibrated television/computer system. A mathematical analysis of the change in these coordinates, as subjects performed set manoeuvres, was developed to provide unique descriptions of the rotational movements in terms of clinical angles related to anatomical frames of reference. The technique produced angles of rotation with maximum errors about any axis of +/- 2 degrees, with a root mean square error of less than 1 degree. The analysis of back movements using surface markers was shown to be feasible from studies of six volunteers who demonstrated consistent patterns of movement which were similar to previously reported patterns of spinal movement measured radiographically.

Back↗
PubMed1987

Prediction of the range of hand positions available to a patient with movement restrictions at the joints of the upper limb--a mathematical model.

A mathematical model has been constructed to predict the workspaces available to patients with reduced ranges of motion at the joints of the upper limb. The model uses the inverse kinematic method of Benati et al. (1982) together with simplified anatomical data. Comparisons with experimental data (Dempster, 1955) show significant discrepancies which are believe to be due to differences in scapular constraint and to simplified anatomical modelling. It is intended to improve the anatomical model by the use of the published data of Eyclesheimer and Shoemaker (1911). Despite the discrepancies, the model already detects significant differences between normal workspaces and those of patients with restriction at the joints of the upper limb. It is believed that this model could, when incorporated with empirical data, form the basis of an "expert" system to assist the therapist and clinician in the planning of rehabilitation of the upper limb.

Activities of Daily Living↗
PubMed1986

Bretylium tosylate enhances salt taste.

Bretylium tosylate (BT), an antifibrillary drug, was found to potentiate the taste of NaCl and LiCl in both humans and rats. Application of 1 mM BT (pH 6.3) to the human tongue statistically potentiated the taste of 0.2 M NaCl and 0.2 M LiCl by 33.5% and 12.5% respectively. Electrophysiological taste responses from nucleus tractus solitarius (NTS) in rat for both hyposmotic and hyperosmotic concentrations of NaCl and 0.1 M LiCl were also increased by 30 to 40% after application of 1 mM BT. This potentiation induced by BT was reduced by amiloride in both humans and rats. Furthermore, amiloride became ineffective in inhibiting taste responses to NaCl in the presence of BT.

Adolescent↗
PubMed1985

Methyl xanthines enhance taste: evidence for modulation of taste by adenosine receptor.

The methyl xanthines (MX), theophylline, caffeine, and theobromine, are potent antagonists of adenosine receptors. Adaptation of the human tongue to methyl xanthines at concentrations ranging from 10(-5) M to 10(-2) M was found to potentiate taste. The artificial sweetener acesulfam-K, which has a bitter component, was potentiated the most by MX, i.e., approximately 100%. This increase in perceived intensity for acesulfam-K occurred at 10(-5) M MX, a concentration known to inhibit adenosine receptors but below that required to inhibit phosphodiesterase. Increasing the concentration of MX as high as 10(-2) M did not increase the degree of enhancement appreciably. Taste enhancement was found for NaCl and quinine hydrochloride as well. When 10(-5) M adenosine was added to the MX, the potentiation was reversed. The human results were confirmed by animal studies in which single unit extracellular recordings were made from the nucleus of the solitary tract. These results suggest that the inhibitory A1 adenosine receptor plays an important local role in taste perception.

1-Methyl-3-isobutylxanthine↗
PubMed1985

Visualization of skin deformation during wound closure.

A simple technique is described which enables the accurate visualization of skin deformation following wound closure. Results obtained during two surgical procedures involving the excision of areas of skin are presented.

Biomechanical Phenomena↗
PubMed1985

The experimental infection of guinea pigs with the tissue worm of deer - Elaphostrongylus cervi.

Infection of six guinea pigs with up to 100 third-stage larvae of Elaphostrongylus cervi produced clinical signs of severe weight loss and ataxia or death in five. These signs occurred approximately eighty days after the larvae had been given per os. Single female E. cervi sub-adults were recovered from four affected animals and both a male and female E. cervi from one animal. Individual worms were found at the base of the brain against the internal surface of the dura mater. Histological and haematological parameters differed significantly between infected and control animals.

Journal Article↗