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Biomedical subjects

D E Bostock

Publications and source records attributed to D E Bostock.

At least 19 recordsLinked to original sources
PubMed1992

Correlation between histologic diagnosis mean nucleolar organizer region count and prognosis in canine mammary tumors.

In this study, surgically excised mammary tumors from 98 bitches were graded histologically, and the grade was compared with the mean nucleolar organizer region (NOR) count in silver-stained paraffin-embedded sections. Histologically benign tumors, papillary adenocarcinomas, and intraductal carcinomas showed relatively little variation; the mean count for each category was between three and four NOR per nucleus. There was, however, a significant increase in the NOR counts in tubular and solid carcinomas. This increase was most pronounced for tumors that showed evidence of infiltration into the surrounding connective tissues. The mean NOR count for noninfiltrative carcinomas was 5.1, and that for invasive carcinomas was 7.3 (P less than 0.03). The mean NOR count for individual carcinomas ranged from 2.0 to 12.3, and a significant correlation was found between an increased NOR count and tumor-related death during the first post-surgical year. The 39 bitches in which the tumor had an NOR count less than 8.0 had a generally favorable prognosis; only six (15%) died as a result of the original neoplasm. In contrast, 18/21 dogs (85%) with a carcinoma having an NOR count greater than 8.0 died from the tumor during the first post-surgical year. A similar, although less pronounced result was obtained specifically for invasive carcinomas, in which 3/12 (25%) tumors with an NOR count less than 6.0 resulted in the death of the host, compared with 17/20 (85%) that had an NOR count greater than 6. By using this technique, it is possible to identify a subgroup of bitches with invasive mammary carcinomas that have a very poor prognosis following apparently adequate surgical ablation of the primary tumor.

Animals↗
PubMed1989

Nucleolar organiser regions as indicators of post-surgical prognosis in canine spontaneous mast cell tumours.

The average number of nucleolar organiser regions per cell has previously been shown to correlate well with histological grading techniques for a variety of neoplasms in man, and may thus be of value as an aid to post-surgical prognosis. In this study 50 spontaneously arising, subcutaneous canine mast cell tumours were graded and the histological grade compared with the mean AgNOR count. For well differentiated neoplasms the mean count was 1.4 per cell compared with 6.3 for poorly differentiated neoplasms, while tumours of intermediate differentiation had a mean count of 3.2 per cell. Subsequent follow up studies revealed that the AgNOR count was an accurate prognostic indicator, 73% of dogs with a high mean count (greater than 4.9) being destroyed from tumour related disease compared with 33% with an intermediate count (1.7-4.8). No dog with a count of less than 1.7 has been destroyed because of tumour recurrence to date and the AgNOR count has proved to be a better and more objective prognostic indicator than either histological tumour grade or mitotic index. Since most dogs which develop recurrent mast cell tumours do so within 6 months of initial surgery, an assessment of the predictive value of AgNORs can be obtained more quickly in canine tumours than for comparable human neoplasms.

Animals↗
PubMed1987

Classification and behaviour after surgery of canine 'epulides'.

Seventy-five surgically excised canine gum neoplasms, which had previously been diagnosed as epulis or ameloblastoma, were reclassified on the basis of their presumed tissue of origin. They included 42 tumours of fibroblastic origin, which contained small foci of odontogenic epithelium and were classified as peripheral odontogenic fibroma, whilst 31 epithelial tumours were classified as basal cell carcinomas arising from the gum epithelium. Two epithelial tumours which apparently arose within the bone of the mandible and were not connected with the surface mucosa were classified as ameloblastomas. Follow-up studies after surgery revealed a recurrence rate of 17 per cent for the odontogenic fibromas and 50 per cent for basal cell carcinomas. Neither of the ameloblastomas, which were initially treated by radical excision, recurred locally and no metastases were detected from any of these tumours.

Ameloblastoma↗
PubMed1984

Comparison of canine oropharyngeal malignancy in various geographical locations.

The variation in prevalence of neoplasms over time and location has been of value in identifying environmental carcinogens. Studies on the relative frequency of the different histological types of canine oropharyngeal malignant neoplasm have shown that squamous cell carcinoma of the tonsil occurs four times more commonly in south east England, and twice as frequently in the United States of America as in Melbourne, Australia. The prevalence of tonsillar squamous cell carcinoma in London in 1950 was 15 times greater than that currently experienced in Melbourne and four times greater than that now found in other areas of south east England.

Animals↗
PubMed1980

Prognosis after surgical excision of canine fibrous connective tissue sarcomas.

One hundred eighty seven dogs from which fibrous connective tissue sarcomas had been excised were studied until death or for at least 3 years after surgery. Dogs with a skin fibrosarcoma had a median survival time of 80 weeks, compared with 140 weeks for animals with haemangiopericytoma in similar sites, this difference being statistically significant. However, the difference in survival time between the two histologic types disappeared when tumours with a similar mitotic index were compared. Dogs with a tumour of mitotic index 9 or more had a median survival time of 49 weeks, compared with 118 weeks for those with a tumour of mitotic index less than 9, regardless of tumour morphology. Tumour recurrence rates of 62% and 25% respectively for the two groups were also significantly different.

Animals↗
PubMed1979

Prognosis after surgical excision of fibrosarcomas in cats.

Forty-four cats from which fibrosarcomas had been excised were studied for a minimum of 3 years, of until death. Two factors, tumor site and mitotic index, were found to be of prognostic significance, but tumor size, duration of growth, and histologic appearance were not. Following removal of fibrosarcomas from the pinna or flank in 6 cats, none died as a result of the tumor but 24 of 35 (70%) cats with fibrosarcoma in the skin of the head, back, or limbs were euthanatized because of local recurrence, usually within 9 months of surgery. The median survival time of cats with a tumor of mitotic index 6 or more in the head, back, or limbs was 16 weeks, compared with 128 weeks when the mitotic index was less than 6. Eleven percent of cats developed pulmonary metastases.

Animals↗
PubMed1979

Prognosis after surgical excision of canine melanomas.

One hundred and thirty-four dogs from which melanomas had been excised were studied until death or for at least 2 years after surgery. Seven of 49 (14%) intraoral and lip tumours and 52 of 85 (61%) skin tumours were histologically benign; in spite of this, three of seven (43%) "benign" oral and four of 52 (8%) "benign" skin lesions led to the eventual death of the host. Thirty eight of 42 (90%) dogs with a histologically malignant melanoma of the lip or oral cavity died because of the tumour but only 15 of 33 (45%) with malignant skin melanomas died. Six of 59 (10%) dogs with a tumour of mitotic index 2 or less died from the tumour 2 years after surgery compared to 19 of 26 (73%) dogs having a tumour with a mitotic index of 3 or more.

Animals↗
PubMed1978

Leukocyte migration inhibition responses in canine lymphosarcoma.

The leukocyte migration inhibition (LMI) responses of 16 cases of canine lymphosarcoma were assessed at several stages of a combined chemotherapy immunotherapy regime. Pooled allogeneic lymphosarcoma cells used in treatment together with other allogeneic lymphosarcoma cells and autochthonous tumour cells were employed as antigens. Positive inhibitions were detected at all stages of treatment when medium controls were used but were not detected in five normal dogs with the same control. There was no association between relapse and remission and LMI response. When a normal lymph-node cell control was used only four dogs produced positive responses, all of which occurred after allogeneic cell administration. These positive responses could not be completely accounted for by sensitization to histocompatibility antigens but as they occurred both in remission and in relapse, including very advanced cases necessitating euthanasia, they were of no value in determining prognoses.

Animals↗