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  • Author or Editor: Douglas H. Thamm x
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in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

To determine the effects of morphine on histamine release from 2 canine mast cell tumor (MCT) cell lines and on plasma histamine concentrations in dogs with cutaneous MCTs.

ANIMALS

10 dogs with cutaneous MCT and 10 dogs with soft tissue sarcoma (STS).

PROCEDURES

The study consisted of 2 phases. First, 2 canine MCT cell lines were exposed to 3 pharmacologically relevant morphine concentrations, and histamine concentrations were determined by an ELISA. Second, dogs with MCT or STS received 0.5 mg of morphine/kg, IM, before surgery for tumor excision. Clinical signs, respiratory rate, heart rate, arterial blood pressure, rectal temperature, and plasma histamine concentrations were recorded before and 5, 15, 30, and 60 minutes after morphine administration but prior to surgery. Data were compared by use of a 2-way ANOVA with the Sidak multiple comparisons test.

RESULTS

In the first phase, canine MCT cell lines did not release histamine when exposed to pharmacologically relevant morphine concentrations. In the second phase, no differences were noted for heart rate, arterial blood pressure, and rectal temperature between MCT and STS groups. Plasma histamine concentrations did not significantly differ over time within groups and between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

No significant changes in histamine concentrations were noted for both in vitro and in vivo study phases, and no hemodynamic changes were noted for the in vivo study phase. These preliminary results suggested that morphine may be used safely in some dogs with MCT.

Free access
in American Journal of Veterinary Research

Abstract

Case Description—A 2-year-old female green iguana was examined for anorexia and swelling and pain on palpation in the cranial cervical area.

Clinical Findings—Marked soft tissue swelling in the cranial cervical area with corresponding cystic swellings in the pharynx were noted. The iguana was considered to be 50% under the expected body weight, given diet and husbandry conditions. The WBC count was markedly elevated, characterized by heterophilia and lymphocytosis. Surgical exploration of the cranial cervical area and histologic and microbial testing identified lymphoma with secondary infection as the cause of the swelling.

Treatment and Outcome—The tumor was initially treated with a single 10-Gy fraction of radiation directed at the masses in the neck. A vascular access port was placed in the ventral abdominal vein, and a canine chemotherapy protocol was modified for use in the iguana. During the course of treatment, the protocol was modified twice. At 1,008 days from the initiation of treatment, the iguana appeared to be in remission.

Clinical Relevance—To our knowledge, this is the first reported use of radiation with doxorubicin, vincristine, cyclophosphamide, and prednisone to successfully manage lymphoma in a reptile. A vascular access port was used effectively for drug administration for an extended period. The doxorubicin, vincristine, cyclophosphamide, and prednisone protocol appeared to be safe and effective in this iguana for the management of lymphoma.

Restricted access
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate the expression of Ki67 and epidermal growth factor receptor (EGFR), mitotic index (MI), and microvascular density (MVD) in feline oral squamous cell carcinoma (SCC) via immunohistochemical staining on archival tumor tissues and to seek a correlation between these markers and clinical variables.

Sample—22 archived tumor samples of feline oral SCC.

Procedures—Immunohistochemical staining for Ki67, MVD, and EGFR was performed and scored. Patient survival information was obtained from the medical records. These molecular markers as well as MI were correlated with tumor locations and patient survival time.

Results—The 22 tumors had wide variation in Ki67 expression, MI, MVD, and EGFR expression. Tongue SCC had higher MVD than did mandibular and maxillary SCC. Tumor expression of EGFR was inversely proportional to survival time.

Conclusions and Clinical Relevance—Results suggested that EGFR expression might be a valuable prognostic factor for treatment outcome in feline oral SCC. It also identified higher angiogenesis in tongue SCC, compared with mandibular and maxillary SCC, which may account for a different clinical outcome. Further prospective characterization of feline oral SCC may provide a better understanding of the underlying molecular factors that drive its behavior and offer the possibility for future patient-specific treatment plans.

Restricted access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate prognostic factors associated with outcome of dogs with multiple cutaneous mast cell tumors (MCTs) treated with surgery with or without adjuvant treatment.

Design—Retrospective case series.

Animals—54 dogs with a minimum of 2 simultaneous, histologically confirmed cutaneous MCTs that had been excised and had adequate staging and follow-up data.

Procedure—Medical records from 1998 to 2004 were examined. Outcome was assessed with the Kaplan-Meier product-limit method and log-rank analysis. Prognostic factors evaluated included signalment; number, histologic grade, location, size, local recurrence, and de novo development of MCTs; quality of surgical margins; clinical signs at the time of diagnosis; and use of adjuvant treatment.

Results—Medical records of 54 dogs with 153 tumors were included. Median follow-up time was 658 days. Median disease-free interval (1,917 days; range, 11 to 1,917 days) and median survival time (1,917 days; range, 14 to 1,917 days) were not yet reached. The 1- year and 2- to 5-year survival rates were 87% and 85%, respectively. The overall rate of metastasis was 15%. Factors that negatively influenced survival time in the univariate analysis included incomplete excision, local recurrence, size > 3 cm, clinical signs at the time of diagnosis, and use of adjuvant treatment. Presence of clinical signs at the time of diagnosis was the only negative prognostic factor for disease-free interval detected in the multivariate analysis.

Conclusions and Clinical Relevance—Results suggested that multiple cutaneous MCTs in dogs are associated with a low rate of metastasis and a good prognosis for long-term survival with adequate excision of all MCTs.

Restricted access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To evaluate effects of substituting mitoxantrone for doxorubicin in a cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapeutic protocol for first-line treatment of dogs with multicentric intermediate- to large-cell lymphoma.

DESIGN Retrospective cohort study.

ANIMALS 44 dogs treated with cyclophosphamide, mitoxantrone, vincristine, and prednisone (CMOP) and 51 dogs treated with CHOP at 12 referral institutions.

PROCEDURES Medical records were reviewed to determine response to treatment, progression-free survival time, and overall survival time. For dogs treated with CMOP, adverse events were also recorded.

RESULTS All 44 (100%) dogs treated with CMOP and 37 of 38 (97.4%) dogs treated with CHOP had a complete or partial response. Median progression-free survival time for dogs treated with CMOP was 165 days (95% confidence interval [CI], 143 to 187 days), and median overall survival time was 234 days (95% CI, 165 to 303 days). For dogs treated with CHOP, median progression-free survival time was 208 days (95% CI, 122 to 294 days), and median overall survival time was 348 days (95% CI, 287 to 409 days). Progression-free and overall survival times were not significantly different between groups. Overall, 9 of the 44 (20%) dogs treated with CMOP had adverse events likely or probably related to mitoxantrone, but all of these adverse events were mild.

CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that mitoxantrone may be a reasonable substitution in a CHOP protocol for treatment of dogs with multicentric intermediate- to large-cell lymphoma when doxorubicin is contraindicated.

Restricted access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To characterize the signalment, clinical signs, biological behavior, and response to treatment of carcinoma of the apocrine glands of the anal sac in dogs.

Design—Retrospective study.

Animals—113 dogs with histologically confirmed carcinoma of the apocrine glands of the anal sac.

Procedure—Data on signalment, clinical signs, and staging were reviewed and analyzed along with treatment modality for potential association with survival time.

Results—Sex distribution was approximately equal (54% female, 46% male). One hundred four dogs underwent treatment consisting of surgery, radiation therapy, chemotherapy, or multimodal treatment. Median survival for treated dogs was 544 days (range, 0 to 1,873 days). Dogs treated with chemotherapy alone had significantly shorter survival (median, 212 days) than those receiving other treatments (median, 584 days). Dogs not treated with surgery had significantly shorter survival (median, 402 days) than those that underwent surgery as part of their treatment (median, 548 days). Dogs with tumors ≥ 10 cm2 had significantly shorter survival (median, 292 days) than dogs with tumors ≥ 10 cm2 (median, 584 days). Hypercalcemia was identified in 27% (n = 29) of dogs, and those dogs had significantly shorter survival (median, 256 days), compared with those that were normocalcemic (median, 584 days). Dogs with pulmonary metastasis had significantly shorter survival (median, 219 days) than dogs without evidence of pulmonary metastasis (median, 548 days).

Conclusions and Clinical Relevance—Unlike most previous reports, this study revealed an approximately equal sex distribution, and results suggest a more favorable prognosis. (J Am Vet Med Assoc 2003;223: 825–831)

Restricted access
in Journal of the American Veterinary Medical Association