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Biomedical subjects

R C Richardson

Publications and source records attributed to R C Richardson.

At least 37 records · Page 2Linked to original sources

Use of cisplatin for control of metastatic malignant mesenchymoma and hypertrophic osteopathy in a dog.

Cisplatin (cis-diammine-dichloroplatinum) treatment induced partial remission of pulmonary metastatic malignant mesenchymoma and nearly complete radiographic remission of hypertrophic osteopathy in a 14-year-old Beagle. Cisplatin was given once every 3 weeks. Clinical signs of hypertrophic osteopathy resolved one week after initiation of treatment. Partial remission of pulmonary metastases and partial radiographic remission of hypertrophic osteopathy was seen 6 weeks after initiation of treatment. Previous treatment of neoplasia-related hypertrophic osteopathy has consisted of removal of the initiating mass or vagotomy. In this case, appropriate chemotherapy was used to control clinical signs and progression of hypertrophic osteopathy.

Animals↗

Classification of primary lung tumors in dogs: 210 cases (1975-1985).

Two hundred ten dogs that had primary lung tumors diagnosed between 1975 and 1985 were evaluated. The majority of the tumors were classified as adenocarcinoma (74.8%) and alveolar carcinoma (20%). The most common clinical signs of disease were cough (52%), dyspnea (23.8%), lethargy (18.1%), weight loss (12.4%), and tachypnea (4.8%). The clinical methods that were most successful in directly or indirectly leading to a diagnosis of primary lung tumor were thoracic radiography (77.1%) and cytologic examination of fine-needle aspirate specimens (24.8%).

Adenocarcinoma↗

Prognostic factors for tumor remission and survival in dogs after surgery for primary lung tumor: 76 cases (1975-1985).

The association of various prognostic factors with remission and survival after the excision of lung tumors was evaluated in 76 dogs. Overall, the median survival time of treated dogs was 120 days; 72% had tumor that underwent remission (median duration of remission, 120 days). Dogs with tumors that underwent remission had significantly (P = 0.001) increased survival time (median, 330 days vs 28 days for dogs with tumors that did not undergo remission). The finding of normal-sized lymph nodes at the time of therapeutic thoracotomy was significantly (P = 0.001) correlated with increased remission probability (85.4% remission rate vs 43.6% in dogs with large lymph nodes). Use of various diagnostic methods to find normal regional lymph nodes before surgery indicated that such finding was significantly (P less than or equal to 0.01) correlated with increased remission duration (median remission duration, 365 days, vs 60 days for tumors in dogs with large lymph nodes), and the finding of normal lymph nodes at the time of surgery was significantly (P less than or equal to 0.01) correlated with increased survival time (median, 345 days, vs 60 days for dogs with large lymph nodes).

Adenocarcinoma↗

Cisplatin chemotherapy for metastatic squamous cell carcinoma in two dogs.

Cisplatin was used successfully to treat 2 dogs with metastatic squamous cell carcinoma. One dog was observed to have a complete remission and died of unrelated causes 23 months later. The other dog had a partial remission of the tumor, but relapsed and was euthanatized 4 1/2 months after the beginning of treatment. Both dogs tolerated the treatment well.

Animals↗

Hyperthermia-induced vascular injury in normal and neoplastic tissue.

The sequential morphologic alterations in normal skeletal muscle in rats, Walker 256 tumors in rats, and transmissible venereal tumors (TVT) in dogs following microwave-induced hyperthermia (43 degrees C and 45 degrees C for 20 minutes), were studied by histologic and ultrastructural examination. Normal muscle and Walker 256 tumors showed edema, congestion, and hemorrhage at 5 minutes post-heating (PH), followed by suppuration, macrophage infiltration, and thrombosis at 6 and 48 hours PH, and finally by regeneration and repair by 7 days PH. Vascular endothelial damage and parenchymal degeneration were present 5 minutes PH. Progressive injury occurred for at least 48 hours PH. Two hyperthermia treatments separated by a 30- or 60-min cooling interval, were applied to Walker 256 tumors in a subsequent study. Increased selective heating of tumor tissue versus surrounding normal tissue, and increased intratumoral steady state temperatures were found during the second hyperthermia treatment. Canine TVTs were resistant to hyperthermia damage. These results suggest that vascular damage contributes to the immediate and latent cytotoxic effects of hyperthermia in normal tissue and some types of neoplastic tissue, and that selective heating of neoplastic tissue occurs in tumor tissue with disrupted microvasculature.

Animals↗

Solid tumors.

Soft-tissue tumors are similar in their behavior. Benign tumors can be easily resected in most cases, whereas malignant tumors are relentless in their locally invasive characteristics. A clear understanding of the constraints of the pathologist in reaching a confirmed diagnosis and a logical plan utilizing surgery as the major modality of therapy are necessary for successful management of these tumors. It appears that radiation combined with hyperthermia is beginning to play a significant role in the local control of soft-tissue sarcomas and that single or multi-agent chemotherapy may be of benefit in treatment of nonresectable or metastatic soft-tissue sarcomas. For the immediate future, surgery remains the only nonexperimental modality of therapy, but the rapid advances in the other therapy methods are encouraging.

Animals↗

Irradiation-hyperthermia in canine hemangiopericytomas: large-animal model for therapeutic response.

Results of irradiation-hyperthermia treatment in 11 dogs with naturally occurring hemangiopericytoma were reported. Similarities of canine and human hemangiopericytomas were described. Orthovoltage X-irradiation followed by microwave-induced hyperthermia resulted in a 91% objective response rate. A statistical procedure was given to evaluate quantitatively the clinical behavior of locally invasive, nonmetastatic tumors in dogs that were undergoing therapy for control of local disease. The procedure used a small sample size and demonstrated distribution of the data on a scaled response as well as transformation of the data through classical parametric and nonparametric statistical methods. These statistical methods set confidence limits on the population mean and placed tolerance limits on a population percentage. Application of the statistical methods to human and animal clinical trials was apparent.

Animals↗

Canine osteogenic sarcoma treated by amputation and MER: an adverse effect of splenectomy on survival.

Canine and human osteogenic sarcomas, like most other malignant tumors, cause or are associated with progressive impairment of host immune reactivity. Adjuvant immunotherapy with live BCG had shown increased survival in one study of canine disease. Experiments with induced fibrosarcomas in mice had suggested that some of the host immune defect might be ameliorated by splenectomy. A prospective clinical trial was conducted with several cooperating veterinary centers. Dogs with osteosarcoma apparently confined to a limb were randomized to be treated by amputation and methanol-extracted residue of BCG (MER), or by the same modalities plus splenectomy. Randomization was discontinued relatively early in the study because of higher mortality in the splenectomy group. Animals treated by amputation and MER could be compared only with historic controls; median and one-year survival rates did not differ significantly from those of prior series. Animals treated by amputation, splenectomy, and MER had significantly poorer survival.

Amputation, Surgical↗

Gentamicin aerosol therapy in 18 dogs: failure to induce detectable serum concentrations of the drug.

Gentamicin was administered as an aerosol to 18 dogs, using a pneumatic nebulizer attached to a face mask. Serum samples were assayed for gentamicin by radioimmunoassay. The antibiotic was not detected in the serum of any dog. It was concluded that the aerosol administration of gentamicin could be considered as topical therapy of the upper respiratory tract and would not induce therapeutic or toxic systemic drug concentrations.

Aerosols↗

Central nervous system depression associated with glucocorticoid ingestion in a dog.

Signs of a central nervous system disorder were observed following 2 instances of accidental ingestion of glucocorticoid in a young female Doberman Pinscher. The signs included transient aggressive and paranoid behavior, amaurosis, disorientation, ataxia with circling backward, and depression. Vomiting, weight loss, and abnormal drinking behavior persisted for several weeks following recovery from the acute illness.

Animals↗

Serum sialic acid levels increased in tumor-bearing dogs.

Serum concentrations of lipid-soluble (glycolipid) sialic acid were determined for 96 client-owned dogs, of which 24 were diagnosed as bearing tumors. A markedly increased concentration of lipid-soluble serum sialic acid was found in 22 of 24 tumor-bearing dogs (92%) compared with 17 of 72 dogs with other definitely false-positive, based on necropsy and follow-up work. Almost all others had acute infections or terminal congestive disorders and were potential tumor bearers. The values obtained appeared to be independent of the sex or age (or both) of the dogs. Based on the analysis of a single biochemical variable, the procedure may permit cancer detection applicable to a wide range of tumor types in dogs if evaluated in terms of the general health status of the animal.

Animals↗

Immune response to phosphorylcholine. I.V. Comparison of homologous and isologous anti-idiotypic antibody.

Homologous and isologous anti-idiotypic antibodies against the PC-binding BALB/c myeloma protein HOPC-8 were raised in A/He and BALB/c mice, respectively. Isologous and homologous anti-HOPC-8 serum suppressed the response to PC in vitro specifically. The antibodies were purified by using HOPC-8 immunoabsorbent. Purified isologous and homologous anti-idiotypic antibody were labeled with 125I and compared for Ig class composition and idiotype-binding specificity. Both kinds of anti-idiotypic antibodies were predominantly IgG1, were highly specific for the HOPC-8 idiotype, and had a smiliar affinities for the PC-binding site. These findings demonstrate that anti-HOPC-8 antibodies raised in A/He and BALB/c mice are very similar in their biologic and immunochemical poperties.

Animals↗