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Biomedical subjects

J A Longstaffe

Publications and source records attributed to J A Longstaffe.

At least 19 recordsLinked to original sources

The Wellcome Trust tropical diseases videodisc project.

This presentation sets out the aims and methodology involved in creating a sophisticated teaching archive in tropical medicine based on the Wellcome Museum of Medical Science. This visual archive will take the form of a videodisc database containing 30,000 video stills combined with a limited amount of moving material. While authoring tools will ensure the continuing production of interactive learning material from the archive, users will have access to several hundred hours of ready made tutorials, and an expert system to teach clinical skills. They will also be able to browse through any part of the archive. Successful management strategies have involved a close and supportive relationship with the project sponsors, the formation of expert groups to solve specific problems, and a process of continuous formative evaluation.

Humans

Equine paranasal sinus cysts: a report of 15 cases.

The clinical and radiographic features of 15 cases of paranasal sinus cysts are described. Breed, sex and side frequency were unremarkable but two distinct categories of age incidence emerged. Onset of signs had occurred before one year of age in three cases, while all but two of the remaining 12 animals were older than nine years. The most common clinical signs were nasal airway obstruction, facial swelling and nasal discharge, often occurring in combination. Radiographic changes were recorded in all horses. Sinus opacification was a consistent finding and in several cases the bone surrounding the sinus had increased in thickness. Increase in intra-maxillary sinus pressure was demonstrated by septal displacement on ventro-dorsal radiographs in almost half the cases. Less common signs included expansion, free fluid accumulation within the affected sinus, dental distortion and displacement and mineralisation. Two horses were destroyed without treatment but in 13 animals surgical exploration was performed. Two of these were destroyed, one at the time of surgery and one five days postoperatively. In the remaining 11 cases, all accessible parts of the cyst were removed through a facial flap and drainage to the nasal meati was established. All these horses recovered satisfactorily and were followed up for periods between three months and six years without evidence of recurrence. Thirteen cysts arose in the caudal maxillary sinus and one each in the frontal and rostral maxillary compartments. Histopathological examination of portions of the cyst walls suggests that, like ethmoidal haematomas, they may originate from episodes of haemorrhage beneath the upper respiratory tract mucosa.

Airway Obstruction

Lymphadenopathy in dogs associated with aluminosilicate.

Granulomatous lymphadenopathy, associated with the presence of needle-like refractile particles, was recognised in two dogs. The material was detected in macrophages, either free within the cytoplasm or in membrane-bound lysosomes. By mineral analysis under direct vision in an electron microscope microanalyser (EMMA 4) the particles were found to contain aluminosilicate.

Aluminum Silicates

Addison's disease in a puppy.

Low serum cortisol levels in a young puppy, following adrenocorticotrophic hormone (ACTH) stimulation, were used to establish a clinical diagnosis of Addison's disease. This was likely to have been congenital although studies of adrenocortical function in close relatives showed no evidence of a genetic origin for the condition. Autoantibody to canine adrenal tissue was not present. Further investigations are necessary to establish the role of autoantibody in canine hypoadrenocorticism. The diagnosis of primary adrenocortical hypoplasia was confirmed at post mortem examination.

Addison Disease

Larval cyathostomiasis (immature trichonema-induced enteropathy): a report of 15 clinical cases.

Clinical and laboratory findings are recorded from a series of 15 cases (aged one to 16 years) of sudden-onset chronic diarrhoea with weight loss, progressing in many cases to emaciation and death, associated with the emergence of fourth stage cyathostome (trichoneme) larvae in large numbers through the colonic and caecal mucosae. Apart from a single incident in mid-October, disease only occurred in winter and spring (January to May). Characteristic features included hypoalbuminaemia, increased alpha and beta plasma globulin levels and neutrophilia without left shift. Faecal egg counts were frequently negative and eosinophilia and anaemia were not features. Horses treated in the early stages responded well to larvicidal doses of fenbendazole (60 mg/kg bodyweight) but in cases where this therapy was delayed for weeks or months the prognosis was poor.

Animals

Osteodystrophia fibrosa in young goats.

Three goats with osteodystrophia fibrosa are described. The main lesions were confined to the mandibles, although in two of the three all bones were rarefied and there were longbone fractures. In two of the three goats, there was evidence of a dietary cause due to selective feeding. In the third, the history was insufficient to indicate a likely cause.

Animal Feed

Phytohaemagglutinin reactivity in circulating peripheral blood lymphocytes during a Trypanosoma brucei infection: sequential studies in individual guinea-pigs.

This study has analysed the response to phytohaemagglutinin of peripheral blood lymphocytes from guinea-pigs infected with Trypanosoma brucei brucei. By this means it was possible to follow the response of individual animals throughout an infection. A culture method using whole blood permitted fewer cell manipulations and eliminated the necessity to supplement cultures with heterologous serum. Selection of appropriate strains of T.b. brucei produced a relatively chronic infection in guinea-pigs. Results from this system indicate that, even late in the disease, significant mitogen reactivity still remains in some individuals. More significantly, these mitogen 'responders' controlled successive parasitaemic waves producing a fluctuating parasitaemia whereas the animals showing poor mitogen responsiveness--'non-responders' failed to control successive waves and showed plateau parasitaemias.

Animals

Nasopharyngeal polyps in the cat.

The occurrence of inflammatory nasopharyngeal polyps is described in a series of four cats. Two of the cats presented with classical features of chronic upper respiratory tract infection, in a third gradual onset of coughing and retching were the only clinical signs, while in the fourth only noisy respiration accompanied the growth. In each cat the polyp was attached to the pharyngeal opening of the eustachian tube and it is suggested that such masses arise from either the lining of the tube itself or that they may even find origin within the tympanic bulla. However, anamnesis and the subsequent clinical and radiographic examinations did not indicate that the polyps were associated with external or middle ear disease. Removal by simple dissection was effected without the necessity of splitting the soft palate in any of the patients and, though expected, recurrence has not yet been seen.

Animals