Search Results
You are looking at 1 - 4 of 4 items for
- Author or Editor: Mark C. Walker x
- Refine by Access: All Content x
Abstract
Case Description—A 5-year-old neutered male mixed-breed dog was evaluated by a veterinarian because of a 4-week history of progressive lethargy and poor appetite; the dog was then examined at a referral hospital.
Clinical Findings—Hyperglobulinemia was identified via serum biochemical analyses performed before and after arrival at the hospital. Lysis of sternebrae 1 and 2 and sternal lymphadenopathy were detected radiographically. Fine-needle aspirates were collected from the affected sternebrae and lymph node for cytologic examination; findings were consistent with pyogranulomatous inflammation associated with fungal infiltrates. Geomyces organisms were identified via microbial culture of sternebral aspirates.
Treatment and Outcome—Treatment consisted of oral administration of itraconazole. After 6 months, remodeling of the affected sternebrae and resolution of sternebral lysis were evident radiographically. Geomyces organisms and pyogranulomatous infiltrates persisted despite clinical improvement. Treatment with itraconazole was continued for an additional 3 months.
Clinical Relevance—Infection with Geomyces organisms is typically localized to the skin and nail beds. In the dog of this report, systemic dissemination of Geomyces organisms resulted in lysis of the first 2 sternebrae. Cytologic examination of fine-needle aspirates and microbial culture of samples of the affected sternebrae were important diagnostic tests for successful identification of the organism. Despite 6 months of itraconazole administration and evidence of clinical improvement, fungal organisms persisted in the dog's affected sternebrae. Practitioners should include Geomyces infection among the differential diagnoses for suspected systemic mycosis and should perform cytologic examination and microbial culture of affected tissue throughout treatment of affected dogs.
Abstract
Objective—To characterize the biological effects of IM administration of a recombinant adeno-associated virus serotype 2 (rAAV2) vector containing feline erythropoietin (fEPO) cDNA and determine whether readministration of the vector or removal of muscle tissue at the injection sites alters those effects.
Animals—10 healthy 7-week-old specific pathogenfree cats.
Procedure—Cats received 1 × 107 infective units (iU; n = 3), 1 × 108 iU (3), or 1 × 109 iU (2) of rAAV2-fEPO vector IM (day 0). Two control cats received an rAAV2 vector containing the LacZ gene (1 × 109 iU, IM). In all cats, hematologic variables and serum fEPO concentration were measured at intervals; anti-rAAV2 antibody titer was measured on day 227. In cats that did not respond to treatment, the rAAV2- fEPO vector was readministered. Injection sites were subsequently surgically removed.
Results—Compared with control cats, cats treated with 1 × 109 iU of rAAV2-fEPO vector had increased Hct and serum fEPO concentrations. One of these cats developed pure RBC aplasia; its Hct normalized following injection site excision. Cats receiving lower doses of vector had no response; on retreatment, 1 of those cats developed sustained erythrocytosis that persisted despite injection site removal and the others did not respond or responded transiently. Antibodies against rAAV2 were detected in all vector-treated cats.
Conclusions and Clinical Relevance—Gene therapy may be an effective treatment for cats with hypoproliferative anemia. However, rAAV2-fEPO vector administration may result in pure RBC aplasia or pathologic erythrocytosis, and injection site removal does not consistently abolish the biological response. (Am J Vet Res 2005;66:450–456)
