Generation of a canine anti-canine CD20 antibody for canine lymphoma treatment.

Lymphoma is the most common hematological cancer in dogs. Canine diffuse large B cell lymphoma shows a relatively good response to treatment with multi-agent cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy; however, the 2-year survival rate is as low as 20%. For human B cell type lymphoma, the anti-CD20 chimeric antibody, rituximab, was developed two decades ago. The combination of rituximab and CHOP chemotherapy was highly successful in improving patient prognosis. However, no anti-canine CD20 antibody is available for the treatment of canine lymphoma. During this study, a rat anti-canine CD20 monoclonal antibody was established. We also generated a rat-canine chimeric antibody against canine CD20 designed for clinical application. This chimeric antibody (4E1-7-B) showed in vitro antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against the canine B cell lymphoma cell line CLBL-1. Moreover, to obtain stronger ADCC activity, a defucosylated 4E1-7-B antibody (4E1-7-B_f) was also generated, and it showed tenfold stronger ADCC activity compared with 4E1-7-B. 4E1-7-B_f as well as 4E1-7-B suppressed the growth of CLBL-1 tumors in an immunodeficient xenotransplant mouse model. Finally, a single administration of 4E1-7-B_f induced considerable peripheral B cell depletion in healthy beagles. Thus, 4E1-7-B_f is a good antibody drug candidate for canine B cell type lymphoma.

Pharmacodynamics of alacepril in healthy cats.

Objectives The aims of this study were to investigate the pharmacodynamics of alacepril and to determine the appropriate dose for clinical usage in cats. Methods Six experimental cats were used. Each cat received alacepril orally at a single dose of 1 mg/kg, 2 mg/kg and 3 mg/kg. Blood samples were collected before administration and at 2, 4, 6, 8, 12, 24, 36, 48 and 72 h after administration to measure serum angiotensin converting enzyme (ACE) activity. Systolic blood pressure was also measured at the same time point. Results Dose-dependent inhibition of ACE activity was observed. Doses of 2 mg/kg and 3 mg/kg alacepril were considered to effectively inhibit ACE activity. There were no significant differences in systolic blood pressue among groups at any time point. Conclusions and relevance Alacepril 2-3 mg/kg q24h may be an appropriate dosage for clinical use in cats.

Combination of Cilostazol and L-Carnitine Improves Walking Performance in Peripheral Arterial Disease Model Rats.

Cilostazol and L-carnitine have been used as a first-line drug and supplement, respectively, in patients with peripheral arterial disease with intermittent claudication. In this study, the effect of the combination of cilostazol and L-carnitine has been investigated in rats with unilateral hindlimb ischemia. For 28 days, cilostazol and L-carnitine were administrated separately or as a combination. The distance walked before gait disturbance developed was measured using a treadmill for 5 days a week. The capillary density of the ischemic hindlimb was evaluated by immunohistochemical staining at days 7, 14, 21, and 28. Angiogenic gene expression was measured by real-time RT-PCR at days 7 and 28. The greatest increase in the distance was observed in the combination therapy group when compared to the other groups. The capillary density in the adductor muscles of rats treated with cilostazol alone and combination therapy increased at day 28. Angiopoietin-2/Angiopoietin-1 expression ratios were higher, suggesting the promotion of angiogenesis, with cilostazol alone and combination therapy at day 7. This is the first study to show functional improvement of the hind limb following combination therapy with cilostazol and L-carnitine in experimental animals. This study also revealed that cilostazol promotes angiogenesis, and L-carnitine additively contributes to functional improvement via a non-angiogenic mechanism.