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Biomedical subjects

K A Hahn

Publications and source records attributed to K A Hahn.

9 recordsLinked to original sources

Clinical response of nasal adenocarcinoma to cisplatin chemotherapy in 11 dogs.

In 11 dogs with nasal adenocarcinoma, IV treatment with 2 to 8 cycles of cisplatin at a dosage of 60 mg/m2 of body surface, given at 3-week intervals, resulted in a survival time of 8 to 128 weeks (mean, 32.7 weeks; median, 20 weeks). Radiography revealed complete remission in 2 dogs and partial remission in 1 dog, for an overall response rate of 27%. Clinical problems such as nasal discharge (n = 11), sneezing (n = 6), and epistaxis (n = 4) resolved in 1 to 2 weeks in all dogs after beginning chemotherapy.

Adenocarcinoma

Nasal adenocarcinoma metastatic to bone in two dogs.

Diagnosis of nasal adenocarcinoma was made in a 6-year-old 35-kg neutered Golden Retriever and a 6-year-old 8-kg spayed mixed-breed dog with chronic bilateral nasal discharge unresponsive to antibiotics. Treatment for the Golden Retriever consisted of bilateral rhinotomy, curettage, and postoperative fractionated 48-Gy orthovoltage irradiation. The mixed-breed dog was treated with cisplatin. After complete remission of the primary neoplasm, the dogs were reevaluated because of acute lameness. Radiography of the right stifle of the Golden Retriever revealed soft tissue swelling, extensive bony destruction of the distal femoral metaphysis and epiphysis, and pathologic fracture involving the medial condyle. Radiography of the left scapula of the mixed-breed dog revealed lysis of the glenoid cavity and subchondral scapular bone. Diagnosis of metastatic carcinoma was made in both dogs. With treatment improvements and longer survival time of affected dogs, sinonasal neoplasia may be observed to develop in similar life-threatening metastatic sites.

Adenocarcinoma

Vincristine sulfate as single-agent chemotherapy in a dog and a cat with malignant neoplasms.

A 12-year-old 4-kg spayed domestic shorthair cat with a poorly differentiated fibrosarcoma of the rostral aspect of the mandible and an 11-year-old 13-kg castrated dog of mixed breeding with pulmonary metastatic hemangiosarcoma were treated with 0.5 mg of vincristine sulfate/m2 of body surface, IV, weekly. Three months after beginning treatment, both animals had complete clinical remission. The role of this vinca alkaloid as a single agent for malignant neoplasms has seldom been discussed in the veterinary scientific literature. The results of these two cases indicate that single-agent vincristine sulfate chemotherapy is effective in the treatment of feline fibrosarcoma and canine hemangiosarcoma.

Animals

Comparison of survey radiography with ultrasonography and x-ray computed tomography for clinical staging of subcutaneous neoplasms in dogs.

A study of 26 dogs (examined consecutively) with infiltrative subcutaneous neoplasms (mastocytoma, n = 11; soft tissue sarcoma, n = 13; and adenocarcinoma, n = 2) was conducted. Dogs were evaluated by physical examination, survey radiography, ultrasonography (US), and x-ray computed tomography (CT) prior to surgical excision of the tumor. The purpose of the evaluation was to accurately define gross neoplastic margins before surgical excision and to determine whether a difference could be observed between routine clinical staging (physical examination and survey radiography) and more detailed clinical staging (US and CT imaging). The clinical stage of 5 of 26 neoplasms assessed by US and of 17 of 26 neoplasms assessed by CT was determined to be more advanced because of previously undetected neoplasia, greater neoplastic size, or greater tissue invasiveness. Preoperative imaging of infiltrative subcutaneous neoplasms, using US and CT, is highly recommended to accurately determine gross neoplastic margins.

Adenocarcinoma

Single-phase methylene diphosphate bone scintigraphy in the diagnostic evaluation of dogs with osteosarcoma.

In this study, 25 dogs each with a histopathologically diagnosed appendicular or axial osteosarcoma were prospectively and consecutively examined by methylene diphosphate nuclear scintigraphy. Scannings that revealed scintigraphically enhanced focal increased activity via bone uptake of the 99mTc methylene diphosphate radionuclide at sites other than the primary tumor site were compared with scintigrams obtained from dogs without osteosarcoma. Secondary scintigraphic sites were evaluated by survey radiography and, if possible, by histologic examination (biopsy or necropsy specimens). On the basis of our findings, scintigraphy seems to be more efficient than physical examination and radiographic bone survey for the diagnosis of multicentric, metachronous, or metastatic canine osteosarcoma.

Animals

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

Functional considerations in partial foot amputations.

Recent developments in both surgical techniques and prosthetic management have improved the prognosis for foot amputations between the transmetatarsal and Syme's levels. Retention of active ankle motion is often permitted by partial foot amputations. Vocational and avocational requirements for active, voluntary ankle motions should be considered preoperatively in selected patients. Three case reports are used to illustrate this concept. Appropriate surgical techniques and prosthetic devices may improve the quality of life for some individuals requiring distal lower extremity amputations.

Amputation, Surgical

Is maintenance chemotherapy appropriate for the management of canine malignant lymphoma?

A retrospective study was conducted between two groups of dogs with histopathologically diagnosed multicentric malignant lymphoma to determine if treatment with either short-term or continuous chemotherapy resulted in a significant difference in first-remission length or survival time. One group was treated with single agent, short-term (three cycles) of doxorubicin. Dogs obtaining complete remission while receiving doxorubicin were given no further chemotherapy. The other group received combination agent, long-term chemotherapy consisting of cyclophosphamide, vincristine sulfate, and prednisone (COP). Dogs obtaining complete remission on COP by the end of 6 weeks were given maintenance chemotherapy of cyclophosphamide, prednisone and methotrexate. One hundred and five dogs were treated. Thirty-eight dogs received doxorubicin and 67 received COP. All dogs were evaluated at 6 weeks for response to chemotherapy and followed until death. No significant differences were observed in first-remission length or survival time when comparing dogs treated with either short-term doxorubicin or long-term COP (P greater than 0.05). Sex, weight, age, clinical stage, performance status, histopathologic cell type, and grade were not significant factors for determining the responsiveness to either chemotherapy protocol. However, within either treatment group, significant differences in first-remission length were observed in dogs evaluated histopathologically by the Keil and NCI working formulation and in survival time when evaluated by performance status (P less than 0.05).

Animals