Search Results

You are looking at 11 - 20 of 23 items for

  • Author or Editor: Lillian Aronson x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract

Objective—To determine whether human CTLA4-Ig ([hu]CTLA4-Ig) inhibits costimulation-dependent lymphocyte proliferation in vitro, compare the effects of (hu)CTLA4-Ig with cyclosporine and steroids on CD4+ and CD8+ T-cell lymphocyte proliferation, and determine whether memory T-cell function remains intact in the presence of (hu)CTLA4-Ig.

Animals—29 cats.

Procedure—Peripheral blood mononuclear cells (PBMCs) were stimulated with concanavalin A (costimulation- dependent mitogen) or phorbol 12-myristate 13-acetate and ionomycin (costimulation independent mitogens) alone or in the presence of (hu)CTLA4-Ig, cyclosporine, or dexamethasone; effects of these treatments on lymphocyte proliferation were assessed by incorporation of thymidine labeled with tritium or flow cytometry. Antigen-specific proliferation was determined by stimulating PBMCs from 2 healthy cats seropositive for Toxoplasma gondii with soluble Toxoplasma antigen alone or in the presence of (hu)CTLA4-Ig or cyclosporine.

Results—(hu)CTLA4-Ig inhibited costimulationdependent lymphocyte proliferation in vitro but had no effect on costimulation-independent lymphocyte proliferation. Compared with mitogen alone, (hu)CTLA4-Ig caused a significant decrease in responder frequency and proliferative capacity of CD4+ T cells; however, the effect on CD8+ T cells was not significant. Cyclosporine alone or with dexamethasone had a significantly greater suppressive effect on responder frequency and proliferative capacity of CD4+ and CD8+ T cells, compared with (hu)CTLA4-Ig. Compared with cyclosporine, (hu)CTLA4-Ig appeared to have a sparing effect on antigen-specific proliferation of memory CD4+ and CD8+ T cells.

Conclusions and Clinical Relevance—(hu)CTLA4-Ig selectively inhibited costimulation-dependent proliferation of lymphocytes in vitro and had a sparing effect on antigen-specific proliferation of memory cells. The specificity of its mechanism of action suggests that (hu)CTLA4-Ig may prevent allograft rejection but leave memory responses to previously encountered antigens intact. (Am J Vet Res 2005;66:483–492)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate effects of cyclosporine, dexamethasone, and the immunosuppressive agent human CTLA4-Ig on cytokine production by feline lymphocytes in vitro and to assess patterns of cytokine production for 5 immunosuppressed renal transplant recipient cats.

Animals—21 clinically normal cats and 5 immunosupressed renal transplant recipient cats.

Procedures—Peripheral blood mononuclear cells were isolated from clinically normal cats and stimulated with concanavalin A (Con A; 10 μg/mL) alone or Con A with cyclosporine (0.05 μg/mL), dexamethasone (1 × 10−7M), a combination of cyclosporine-dexamethasone, or human CTLA4-Ig (10 g/mL). Cells from transplant recipients were stimulated with Con A alone. An ELISA was performed to measure production of interferon (IFN)-γ, granulocyte macrophage–colony stimulating factor (GM-CSF), interleukin (IL)-2, IL-4, and IL-10. Proliferation of CD4+ and CD8+T cells from immunosuppressed cats were also evaluated. Pairwise comparisons were performed via a Wilcoxon signed rank test or Wilcoxon rank sum test.

Results—Cyclosporine, dexamethasone, cyclosporine-dexamethasone combination, and CTLA4-Ig caused a significant decrease in IL-2, IFN-γ, and GM-CSF production. Cyclosporine and cyclosporine-dexamethasone, but not human CTLA4-Ig, caused a significant decrease in IL-10 production. High basal concentrations of IL-2 and IL-10 were identified in transplant recipients, and IL-10 was significantly increased in stimulated cultures. In immunosuppressed cats, there was a decrease in frequency of responders and proliferative capacity of CD4+ and CD8+T cells.

Conclusions and Clinical Relevance—CTLA4-Ig successfully inhibited proinflammatory cytokines while sparing cytokines critical for allograft tolerance. These data may be useful for developing better strategies to prevent rejection while sparing other immune functions.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To identify factors associated with short-term (30-day) and overall survival rates in cats that underwent renal transplantation surgery (RTS).

Design—Retrospective cohort study.

Animals—94 cats that underwent RTS from 1998 through 2010.

Procedures—Data obtained from the medical records pertinent to RTS included cat signalment; anesthetic agents, techniques, and timings; supportive treatment; perioperative physiologic findings; and surgery and warm ischemia times. Associations with short-term and overall survival rates were investigated.

Results—Median survival time was 653 days (range, 2 to 4,580 days). Prolonged anesthesia (median, 300 minutes; range, 225 to 445 minutes) reduced overall survival rate but did not influence short-term survival rate. No associations were identified between survival rates and anesthetic agent used, amount and type of fluid administered IV, physiologic abnormalities, and blood product administration. All cats that received μ-opioid receptor antagonists at anesthetic recovery to reverse the effects of μ-opioid receptor agonists survived for at least 30 days. High Hct at the end of anesthesia was also associated with an increase in short-term survival rate. Two cats had an intraoperative hemoglobin oxygen saturation < 90%, and both died within 7 days after surgery. Cats > 12 years old had a lower overall survival rate than did younger cats.

Conclusions and Clinical Relevance—Minimization of total anesthesia time, reversal of μ-opioid receptor agonists at the end of anesthesia, and prevention of intraoperative decreases in blood oxygen saturation and postoperative decreases in Hct appeared to help maximize postsurgical survival time in cats undergoing RTS.

Full access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

To describe the clinical presentation, novel surgical approach, and outcome of a dog diagnosed with chondro-osseous respiratory epithelial adenomatoid hamartoma (COREAH).

ANIMAL

5-year-old castrated male Yorkshire Terrier.

CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES

The dog was presented with chronic upper respiratory noise, congestion, facial swelling, ocular discharge, and an abscess on the nasal bridge. Two CT scans were performed 4 months apart. The CT scans yielded similar results: cyst-like nasal masses with severely destructive bilateral rhinitis with extensive polyostotic bony lysis. A dorsal rhinotomy with a turbinectomy and debridement of the nasal cavity were performed. A poorly defined but extensive lesion was found occupying the entirety of the left frontal sinus as well as the nasal cavity.

TREATMENT AND OUTCOME

Histopathology revealed a mass consistent with COREAH. The dog recovered well from surgery, except for self-limiting subcutaneous emphysema, and 3 weeks postoperatively was reportedly doing well, with mild nasal discharge. Stridor, nasal discharge, and sneezing episodes were reported postoperatively; however, these were improved. At 18 months postoperatively, the dog died from uncontrolled seizures while hospitalized for suspected acute hemorrhagic diarrhea syndrome at a different hospital.

CLINICAL RELEVANCE

COREAH should be considered a potential cause of destructive bilateral rhinitis and bony lysis in dogs. Dorsal rhinotomy can be a surgical treatment for dogs with possible COREAH with acceptable outcome, though complete remission of clinical signs may not be achieved. This is the first clinical description of COREAH in a dog.

Free access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

To evaluate the effects of Toxoplasma gondii infection in feline renal transplant recipients with a preoperative seronegative or unknown serostatus (SN-UNK) for T gondii and the efficacy of lifelong prophylactic treatment of T gondii infection in feline renal transplant recipients with a preoperative seropositive serostatus (SP) for T gondii.

ANIMALS

24 cats with various serostatuses for T gondii before undergoing renal transplantation.

PROCEDURES

Medical records of cats that had undergone renal transplantation from 1998 through 2018 were reviewed. Two groups of cats were identified. Before renal transplantation, the SN-UNK group cats were seronegative for T gondii (n = 4) or serostatus for T gondii was unknown (4). The SN-UNK group cats received immunosuppressive therapy but were not maintained on prophylactic treatment of T gondii infection. The SP group cats were seropositive for T gondii (n = 16) prior to initiation of immunosuppressive therapy and renal transplantation and were managed after surgery with prophylactic treatment of T gondii infection.

RESULTS

All 8 SN-UNK group cats developed T gondii infections after initiation of immunosuppressive therapy and renal transplantation; T gondii infections were fatal in 6 cats. Of 16 SP group cats, 1 developed a nonfatal T gondii infection resulting in an allograft rejection episode. No SP group cats, which were managed postoperatively with prophylactic treatment, developed a fatal T gondii infection.

CONCLUSIONS AND CLINICAL RELEVANCE

T gondii infection resulted in morbidity and death in immunosuppressed cats not receiving prophylactic treatment of T gondii infection after renal transplantation. Seropositive cats were acceptable candidates for renal transplantation when lifelong prophylactic treatment of T gondii infection was provided.

Full access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To assess the utility of ultrasonography to detect the cause and location of ureteral obstruction in cats and to identify factors associated with agreement between ultrasonographic and surgical findings.

STUDY DESIGN Retrospective case series.

ANIMALS 71 cats.

PROCEDURES Medical records were searched to identify cats that had ureteral obstruction diagnosed ultrasonographically and that subsequently underwent exploratory laparotomy. Patient signalment, ultrasonographic findings, interventions performed, and surgical findings were recorded. Cause and location of ureteral obstruction as assessed by ultrasonography were compared with surgical findings. Sensitivity, specificity, and positive predictive value of ultrasonography for detection of ureteroliths and strictures were calculated. Statistical analysis was performed to identify factors associated with agreement between ultrasonographic and surgical findings.

RESULTS There was significant, moderate agreement between ultrasonographic and surgical findings for the cause and location of ureteral obstruction. Signalment variables, ureter affected (left vs right), and presence of retroperitoneal effusion were not associated with this agreement. Sensitivity was 98% and 44%, specificity was 96% and 98%, and positive predictive value was 98% and 88% for detection of ureteroliths and strictures, respectively, by ultrasonography.

CONCLUSIONS AND CLINICAL RELEVANCE Ultrasonography was highly sensitive for detection of ureteroliths that caused ureteral obstruction but was considerably less sensitive for detection of ureteral strictures in the study population. Future prospective studies are needed to determine the role of advanced imaging in assessing cats with ureteral abnormalities. (J Am Vet Med Assoc 2019;254:710–715)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine outcome of renal transplantation in cats with renal failure associated with calcium oxalate urolithiasis.

Design—Retrospective case series.

Animals—19 cats.

Procedure—Medical records were reviewed for evaluation of signalment, preoperative clinical signs, physical examination results, dietary history, clinicopathologic data, abdominal imaging, postoperative diet, complications, and long-term outcome.

Results—The domestic shorthair was the most common breed represented. There were 13 spayed females and 7 castrated males. Mean age was 6.8 years. Clinical signs included weight loss, lethargy, vomiting, anorexia, polyuria, and polydipsia. Before surgery, cats received commercially available canned or dry food (n = 10), a prescription renal failure diet (5), a commercial diet to manage struvite crystalluria (1), or an unknown diet (3). Seventeen cats were anemic. All cats were azotemic. Hypercalcemia was detected in 7 cats. Abdominal imaging revealed nephrolithiasis, ureterolithiasis, or both in all cats. Median duration of survival of all cats was 605 days. Eight cats were alive 282 to 2,005 days (median, 1,305 days) after surgery. Eleven cats died 2 to 1,197 days (median, 300 days) after surgery. Five cats formed calculi in their allograft (120 to 665 days). Two of the 5 cats that formed calculi were hypercalcemic. Four of the 5 cats died following complications associated with formation of calculi.

Conclusions and Clinical Relevance—Renal transplantation appears to be a viable option for cats in renal failure secondary to calcium oxalate urolithiasis. In addition to reported complications in renal transplant recipients, formation of calculi within the allograft may also occur.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the underlying cause, pathophysiologic abnormalities, and response to treatment in cats with septic peritonitis and identify differences between cats that survived following treatment and cats that did not survive despite treatment.

Design—Retrospective study.

Animals—51 cats with septic peritonitis.

Procedure—Medical records were reviewed for clinical findings; results of clinicopathologic testing, microbial culture, and radiography; diagnosis; treatment; and outcome.

Results—Signs of pain during palpation of the abdomen were reported for only 29 of 47 (62%) cats. Eight (16%) cats had relative bradycardia (heart rate < 140 beats/min). The most commonly isolated organisms included Escherichia coli, Enterococcus spp, and Clostridium spp. The most common cause of peritonitis was gastrointestinal tract leakage (24 cats). No definitive source could be identified in 7 cats. Treatment, including exploratory surgery, was pursued in 23 cats, of which 16 (70%) survived and were discharged. There were no significant differences between survivors and nonsurvivors in regard to heart rate, age, rectal temperature, serum lactate concentration, WBC count, PCV, blood glucose concentration, or serum albumin concentration.

Conclusions and Clinical Relevance—Results suggest that clinicopathologic abnormalities and outcome in cats with septic peritonitis are similar to those reported for dogs. However, certain features may be unique, including an absence of signs of pain during abdominal palpation, relative bradycardia, and apparent spontaneous peritonitis in some cats. (J Am Vet Med Assoc 2004;225:897–902)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To investigate the clinicopathologic patterns of the erythropoietic response after renal transplantation in cats with chronic renal failure (CRF).

Animals—14 cats with CRF undergoing renal transplantation.

Procedure—Before and at intervals during a 6-month period after transplantation, serum creatinine and erythropoietin concentrations, Hct, erythrocyte indices, aggregate reticulocyte percentage, and iron variables were measured. Additionally, the number of transfusions administered to and any complications that developed in each cat were recorded.

Results—In all cats, preoperative azotemia resolved within 6 days after renal transplantation. Two cats had a temporary increase in serum creatinine concentration secondary to an acute graft rejection episode. Anemia (defined as Hct < 28%) resolved in 10 cats 3 to 49 days after surgery. Resolution of anemia was delayed in 2 cats that had acute rejection episodes. Serum erythropoietin concentration and reticulocyte percentage were low preoperatively; values after surgery were highly variable. Compared with preoperative values, serum erythropoietin concentration increased 1 to 4 days after surgery in 11 cats; between days 5 and 58, another increase was detected in 9 cats. Serum iron concentrations were generally low before and 14 days after transplantation.

Conclusion and Clinical Relevance—The erythropoietic response was highly variable in cats after renal transplantation, but anemia typically resolved within 1 month after surgery. A delay in resolution of anemia in cats may indicate poor graft function and inadequate iron stores, suggesting the need for further evaluation for concurrent illness. (Am J Vet Res 2003;64: 1248–1254)

Full access
in American Journal of Veterinary Research