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Biomedical subjects

R C Rosenthal

Publications and source records attributed to R C Rosenthal.

28 records · Page 2Linked to original sources

Pharmacokinetics of lithium in the dog.

The pharmacokinetics of lithium were determined in eight adult dogs. The data were fitted to a two-compartment model. Single intravenous doses of lithium chloride, and single oral doses of lithium carbonate were used. The mean plasma lithium half-life (t1/2) following the single intravenous dose was 21.6 h, and the mean apparent specific volume of distribution of the central compartment (V'c) was 0.189 l/kg. Mean bioavailability was 78.8% following oral administration.

Administration, Oral↗

Detection of canine antisperm antibodies by indirect immunofluorescence and gelatin agglutination.

Canine infertility has diverse and multiple causes. Immunologic infertility due to antisperm antibody is recognized and quantitated in other species, but this entity appears not to have been described in the dog. Before this time, there has been no practicable and reliable method to measure canine antisperm antibodies. This study was directed at inducing the production of such antibodies by immunizing dogs with sperm antigens and measuring the resulting antibodies, using the recognized techniques of indirect fluorescent antibody testing and sperm agglutination testing. Measurable antibody responses were observed.

Agglutination Tests↗

Plasma histamine and gastrin concentrations in 17 dogs with mast cell tumors.

Dogs with mast cell tumors (MCT) are often affected with paraneoplastic syndromes such as gastrointestinal ulceration. The mechanism of ulceration is believed to be related to hyperhistaminemia. To test this hypothesis, plasma histamine and gastrin concentrations were measured in 17 dogs with MCT. Plasma histamine concentrations in dogs with MCT were significantly higher than those in normal dogs. Conversely, plasma gastrin concentrations in dogs with MCT were significantly lower than gastrin concentrations in normal dogs. Additionally, plasma gastrin concentrations were inversely related to plasma histamine concentrations, which provided indirect evidence for the presence of hyperacidity secondary to hyperhistaminemia (r2 = 57.7). Plasma histamine and plasma gastrin concentrations were not related to clinical stage of disease, tumor histologic grade, or tumor size. Median survival time was 245 days, with a range of 90 to 1315 days. Because the degree of hyperhistaminemia could not be predicted in this study from the clinical stage, histologic grade, or tumor size, these data suggest that hyperhistaminemia may occur in any dog with MCT.

Animals↗

Evaluation of L-asparaginase: polyethylene glycol conjugate versus native L-asparaginase combined with chemotherapy. A randomized double-blind study in canine lymphoma.

L-asparaginase is an enzyme that inhibits protein synthesis by the depletion of sources of L-asparagine, which is necessary for transformed lymphoid cells to proliferate. L-asparaginase is used in the treatment of childhood acute lymphoblastic leukemia. A problem with L-asparaginase therapy is the immunogenicity of the enzyme and the development of anaphylactic reactions. Canine lymphoma is a predominantly B-cell tumor with widespread disease; without treatment, dogs with lymphoma usually survive 1-2 months. Canine lymphoma will respond to L-asparaginase therapy. A randomized double-blind study evaluated a polyethylene glycol (PEG) conjugate L-asparaginase combined with chemotherapy (vincristine, cyclophosphamide, doxorubicin, and prednisone). Thirty-five dogs were randomized to the PEG L-asparaginase group, and 34 dogs were randomized to the native L-asparaginase group. Thirty dogs (85.7%) achieved a complete remission (CR) with a median time to relapse of 217 days, and 32 (94.1%) dogs in the native L-asparaginase group achieved a CR with a median time to relapse of 214 days (P greater than 0.05). The asparaginase was well tolerated in both groups. Two dogs in the native L-asparaginase group had severe allergic reactions, and one dog in the PEG asparaginase group had a generalized urticarial reaction after repeated injections. This study indicates that PEG L-asparaginase has equal therapeutic efficacy to native L-asparaginase.

Animals↗

Evaluation of prognostic factors and sequential combination chemotherapy with doxorubicin for canine lymphoma.

Fifty-five dogs with lymphoma were treated using a doxorubicin-based sequential combination chemotherapy protocol. Complete response, partial response, and no response were seen in 46, 4, and 5 dogs, respectively. The overall median remission duration and survival times were 36 and 51 weeks, respectively. Age, sex, weight, World Health Organization stage, World Health Organization substage (i.e., a = not ill, b = ill), serum calcium concentration, blood urea nitrogen concentration, breed and protocol alteration secondary to toxicity were evaluated for prognostic significance. Univariate analysis of prognostic factors identified sex, World Health Organization substage, and serum calcium as statistically significant (P < or = .05) variables for both survival and remission duration. Upon multivariate analysis, only substage (P = .036) was a significant prognostic factor for remission duration, whereas, both substage (P = .006) and sex (P = .005) were significant prognostic factors for survival.

Animals↗

Canine bone marrow as a potential thermal sanctuary during the plateau phase of 41.8 degrees C whole body hyperthermia.

Whole body hyperthermia (WBH) is currently being evaluated as an adjunct to various forms of antineoplastic therapy. In this regard, the uniformity of temperature in an individual subject, induced by any given WBH system, is a significant factor. Preliminary animal investigations suggested that the bone marrow temperature may differ from core temperature during 41.8 degrees C WBH. To quantitatively evaluate this possible phenomena, dogs were utilized in conjunction with a radiant heat WBH system. It was found that mean bone marrow temperature was significantly less than core (i.e. rectal) temperature (p < 0.001), i.e. 0.27 degree C for the ilium 0.40 degree C for the humerus and 0.95 degree C for the tibia. The implications of these results to current clinical trials are discussed.

Animals↗