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Biomedical subjects

J M Sharp

Publications and source records attributed to J M Sharp.

At least 73 records · Page 4Linked to original sources
PubMed1993

Enzootic intranasal tumour of goats in Italy.

An outbreak of enzootic intranasal tumour (EIT) in a goat herd in Central Italy is described. From October 1990 to September 1992 41 tumors were diagnosed in goats ranging in age from 6 months to 6 years and of both the Alpine and Saanen breeds. Clinically the affected goats showed nasal discharge, facial swelling, sneezing and snoring respiration and weight loss. Post-mortem examinations revealed uni- or bilateral tumours of the olfactory mucous membrane. The neoplasms were classified as low grade adenocarcinomas. Ultrastructurally, retrovirus-like particles were observed in 10/10 tumours examined. Epidemiological and ultrastructural findings strongly suggest a viral aetiology for intranasal enzootic adenocarcinoma in the goats examined.

Adenocarcinoma↗
PubMed1991

Enzootic nasal tumour of goats: demonstration of a type D-related retrovirus in nasal fluids and tumours.

Nasal exudate and tumour tissue from goats with enzootic nasal tumours were shown to contain a reverse transcriptase activity associated with a particle of buoyant density typical of retroviruses. The same particle contained a 25,000 Mr protein that cross-reacted with the p27 of Mason-Pfizer monkey virus (MPMV) and with p25 of sheep pulmonary adenomatosis retrovirus. It also contained a low Mr protein related to p10-12 of MPMV.

Animals↗
PubMed1991

Pathology of enzootic intranasal tumor in thirty-eight goats.

Intranasal tumors were studied in 38 goats ranging from 7 months to 8 years of age of both Murciana-Granadina and crossed breeds. Tumors were diagnosed in eight herds. Clinically, the affected goats showed a copious seromucous nasal discharge, ocular protrusion, and skull deformations. The tumors originated from the ethmoid region. They involved one or both nasal cavities, although most were bilateral (26/38). The tumors were generally accompanied by inflammatory polyps. The histologic patterns were very similar in all cases, and the tumors were classified as low grade adenocarcinomas of the nasal glands. Histochemical, immunohistochemical, and ultrastructural studies suggested that the serous glands of nasal mucosa were the probable origin of the neoplastic cells. Budding and extracellular retrovirus-like particles were observed ultrastructurally in 6/8 tumors. The similarities between these caprine tumors and nasal tumors in sheep and the etiologic role of the retrovirus are discussed.

Adenocarcinoma↗
PubMed1988

Group-specific and type-specific gel diffusion precipitin tests for bluetongue virus serotype 20 and related viruses.

Using antigens prepared from cell cultures infected by bluetongue (BLU) virus type 20 (BLU-20), and sera from cattle which had recovered from experimental infection by that virus, two distinct precipitin reactions were demonstrated by immunodiffusion. Two distinct gel diffusion precipitin tests were developed based on these reactions. The antigen of one was common to BLU-20 and two other Australian BLU isolates, CSIRO 154 (BLU-21) and CSIRO 156 (BLU-1). It was therefore concluded to be a group-specific test. The antigen of the second appeared to be unique to BLU-20. The test based on this antigen correlated well with the virus neutralization test for BLU-20 and it was therefore concluded to be type-specific. Similar methods applied to a virus of the Palyam (PAL) group demonstrated two precipitin reactions of similar broad (group) and narrow (type) specificity.

Animals↗
PubMed1988

Bluetongue and related viruses in New South Wales: isolations from, and serological tests on samples from sentinel cattle.

Sentinel cattle at a number of localities in northern and central coastal New South Wales were sampled over the summer and autumn seasons of the years 1979, 1980 and 1981. A total of 118 orbiviruses were isolated; 99 were of the Palyam group, 15 were of the epizootic haemorrhagic disease (EHD) of deer group, and 4 of the bluetongue group. The Palyam group viruses were identified by serotype as 68 Bunyip Creek, 23 CSIRO Village, 7 D'Aguilar and one was not typed. The EHD viruses were identified as 13 type 5 and 2 type 6. All 4 bluetongue viruses were type 21. There was also convincing serological evidence that bluetongue type 1 infection occurred in 1980. Antibody to the bluetongue group, as demonstrated in a gel diffusion precipitin test, was often transient. It appeared to be mostly cross-reactive with, and induced by, other orbivirus infections, particularly those of the EHD group. Viruses of the Palyam group also seemed to be implicated in some circumstances. Where infections by viruses of the bluetongue group were demonstrated, the precipitating antibody responses to a bluetongue group antigen were not noticeably stronger than many which followed EHD virus infection. The results generally confirm previous conclusions, deduced from serological surveys, regarding the frequency of orbivirus infections, the presence of bluetongue viruses, and the transient nature of many bluetongue group antibody reactions.

Animals↗
PubMed1988

Lesions and retroviruses associated with naturally occurring ovine pulmonary carcinoma (sheep pulmonary adenomatosis).

Five sheep with ovine pulmonary carcinoma were markedly dyspneic and had sporadic coughing; two had copious watery nasal exudate. In four, lesions consisted of multifocal nodules of neoplastic cuboidal epithelial cells in acinar or papillary patterns. Electron microscopically, cells had microvilli, tight junctions, and cytoplasmic lamellar bodies typical of alveolar type II cells. One sheep had a single lung tumor of nonciliated bronchiolar epithelial cells. Vacuolated alveolar macrophages surrounded adenomatous foci. One sheep had a metastatic lesion in the caudal mediastinal lymph node. All sheep had histologic lesions of lymphoid interstitial pneumonia (LIP, ovine progressive pneumonia) consisting of peribronchiolar and interstitial lymphoid hyperplasia, and fibromuscular proliferation; all had serum precipitating antibodies to ovine lentivirus. Lung fluids or tumor homogenates contained a 26-kd peptide that crossreacted with a primate-derived type D retrovirus as detected by immunoblotting or interspecies competition radioimmunoassay. Ovine lentivirus was isolated from concentrated lung fluids or tumor tissues of four sheep tested and from tumor cell DNA of one animal transfected into ovine muscle cells. These studies document the presence of type D-related retrovirus antigen in ovine pulmonary carcinoma (OPC) in the United States and indicate that lentivirus-induced LIP is a lesion frequently associated with this disease.

Animals↗
PubMed1987

Sheep pulmonary adenomatosis: a contagious tumour and its cause.

Sheep pulmonary adenomatosis (SPA) is a contagious lung tumour that can be transmitted experimentally. Two viruses have been associated with the disease, a herpesvirus and a retrovirus. All ovine herpesviruses are related antigenically and have been isolated only from SPA tumour tissues. They do not appear to cause the tumour and their association with SPA appears to arise from reactivation of latent virus in the respiratory tract. SPA tumour tissue and lung fluid contain a retrovirus that has properties similar to those of type B and type D retroviruses. Homogenates of tumour that contain this retrovirus can transmit SPA to experimentally inoculated sheep. Various retroviruses have been cultured from such tumours. Only one of these has properties similar to that of the retrovirus detected in the tumour and it can transmit SPA experimentally. The others appear to be isolates of the non-oncogenic ovine lentivirus, maedi-visna virus, and play no part in the aetiology of SPA.

Animals↗
PubMed1987

Experimental coinduction of type D retrovirus-associated pulmonary carcinoma and lentivirus-associated lymphoid interstitial pneumonia in lambs.

Two retrovirus-associated pulmonary diseases of sheep [ovine pulmonary carcinoma (OPC); sheep pulmonary adenomatosis], a bronchoalveolar carcinoma, and lymphoid interstitial pneumonia (LIP) were induced simultaneously in 9 of 9 neonatal lambs. The lambs were killed 8-28 weeks after intratracheal injection of lung tumor homogenate or lung fluid derived from sheep with naturally occurring OPC and ovine lentivirus (OvLV) infection. The inoculated lambs developed multifocal neoplasms of alveolar type II cells or nonciliated bronchiolar epithelial cells, LIP, and pulmonary lymph node hyperplasia, and all produced antibody to OvLV. OvLV was isolated from 6 to 7 lambs tested, and infectious center assay of pulmonary lavage cells from 3 lambs revealed that approximately 1 in 1,000 pulmonary lavage cells contained infectious lentivirus. Neither contact control lambs nor control lambs that received ultrafiltered lung fluid developed evidence of either disease or of OvLV infection. Lung fluid or tumor tissue of lambs with OPC contained a 26,000-dalton protein that cross-reacted with antiserum to p27 to Mason-Pfizer monkey virus, a type D retrovirus. The fact that no antigenic cross-reaction between OvLV and type D retroviruses has been demonstrated supports the presence of two retroviruses in sheep with OPC. Although the contributions of each agent to oncogenesis in this model are difficult to evaluate, the rapid development of two retrovirus-induced pulmonary diseases in experimentally inoculated lambs suggests an etiologic or pathogenetic synergism between these two members of the family Retroviridae.

Animals↗
PubMed1984

Development of a combined clostridial and Pasteurella haemolytica vaccine for sheep.

The efficacy of a multicomponent clostridial vaccine containing Pasteurella haemolytica antigens was tested in specific pathogen free or conventionally reared lambs exposed to experimental infection with P haemolytica serotypes A1, A2 or A6. In four experiments assessment was based upon the findings of clinical, pathological and bacteriological examinations. Three experiments carried out in conventionally reared lambs demonstrated protection against challenge infection with P haemolytica serotypes A1, A2 and A6 in vaccinated lambs. However, the inconsistency of the disease induced in these experiments emphasised the need to perform definitive studies in specific pathogen free conditions. The final experiment was carried out with specific pathogen free lambs and confirmed the efficacy of the multicomponent clostridial vaccine containing P haemolytica antigen in protecting against the effects of infection with P haemolytica serotype A6. In addition, this experiment indicated that the inclusion of several components in a vaccine did not affect the efficacy of an individual antigenic component.

Animals↗
PubMed1984

Infection of specific-pathogen free lambs with a herpesvirus isolated from pulmonary adenomatosis.

In two experiments, 18 specific-pathogen free (SPF) lambs were inoculated by several routes with the Scottish strain of caprine herpesvirus 1 (CHV 1). Seventeen of the lambs developed interstitial changes in the lungs ranging from focal cellular infiltration to a widespread proliferative pneumonia. Five weeks after the initial inoculation 3 lambs were given a course of corticosteroid by intravenous injection. Subsequently virus was reisolated from all 3 lambs. Virus was also recovered from one of these lambs on one occasion prior to steroid treatment. It has therefore been established that CHV 1 can cause pneumonia and can be reisolated from infected sheep for at least 6 weeks after infection. It is suggested that CHV 1 might cause a latent infection in sheep which is reactivated following the development of pulmonary adenomatosis.

Animals↗
PubMed1983

Isolation of a syncytium-forming virus from a goat with polyarthritis.

Virus particles, morphologically indistinguishable from maedi-visna virus or caprine arthritis-encephalitis virus, were detected in tissue explant cultures prepared post mortem from a goat with joint, lung and kidney lesions similar to those associated with the caprine arthritis-encephalitis complex. Serum from this goat and others in its herd of origin gave positive reactions in an agar gel immunodiffusion test for maedi-visna virus antibodies.

Animals↗
PubMed1983

Rapid transmission of sheep pulmonary adenomatosis (jaagsiekte) in young lambs. Brief report.

Jaagsiekte, a contagious lung tumour of sheep, was induced within 3-6 weeks in day-old lambs by intratracheal inoculation of SPA lung fluids concentrated by centrifugation. Electronmicroscopic examination of the tumour revealed retrovirus particles whose morphogenesis and morphology support biophysical and immunological findings that suggest a relationship with type B and type D retroviruses.

Animals↗
PubMed1983

Further evidence for a retrovirus as the aetiological agent of sheep pulmonary adenomatosis (jaagsiekte).

The infective agent of jaagsiekte was shown to be present in the fluid which accumulates in the respiratory tract of sheep during the terminal stages of the disease. The fluid also contained reverse transcriptase (RT) activity which showed a clear preference for a ribonucleic acid synthetic template over the corresponding deoxyribonucleic acid template and which utilised the RT specific template/primer poly (2'-0-methylcytidylate) oligodeoxyguanylate. This enzyme activity was associated with a particle which had typical retroviral buoyant densities in a range of gradient media.

Animals↗
PubMed1983

Experimental immunisation of lambs against pneumonic pasteurellosis.

Methods of immunising lambs against pneumonic pasteurellosis, caused by several serotypes of Pasteurella haemolytica, were assessed in specific pathogen free lambs. Lambs were vaccinated intramuscularly with sodium salicylate extract (SSE) of P haemolytica, either alone or in combination with heat-killed organisms (HKO). SSE of P haemolytica type A1 protected vaccinated lambs against pneumonia resulting from challenge with the homologous serotype. SSE of type A2 also provided some protection but this was improved by vaccination with a combination of SSE and HKO.

Animals↗