Effects of the cyclooxygenase inhibitor, piroxicam, on tumor response, apoptosis, and angiogenesis in a canine model of human invasive urinary bladder cancer.

The mechanisms by which cyclooxygenase inhibitors exert antitumor effects are not completely defined but are postulated to involve antiangiogenic effects and induction of apoptosis. In this study, we determined the effects of the cox inhibitor, piroxicam, on tumor response, apoptotic index, proliferative index, cyclooxygenase-2 expression, prostaglandin E(2) concentration, tumor microvessel density, and urine basic fibroblast growth factor and vascular endothelial growth factor concentrations in pet dogs with naturally occurring invasive transitional cell carcinoma of the urinary bladder. Piroxicam caused reduction in tumor volume in 12 of 18 dogs, and this was strongly associated with induction of apoptosis (Fisher's exact test P < 0.015) and reduction in urine basic fibroblast growth factor concentration.

Detection of synovial macrophages in the joint capsule of dogs with naturally occurring rupture of the cranial cruciate ligament.

OBJECTIVE: To test the hypotheses that the densities of macrophages in the synovial membranes and capsules of stifle joints in dogs with ruptured cranial cruciate ligaments are greater than those of normal joints and that those densities in affected joints are positively correlated with the chronicity and severity of the disease. ANIMALS: 17 dogs with naturally occurring rupture of the cranial cruciate ligament and 5 healthy control dogs. PROCEDURE: All dogs underwent orthopedic and radiographic evaluations. In affected dogs, duration of clinical signs was used as an indicator of disease chronicity and the severity of osteoarthritis in the stifle joint was determined radiographically. Joint capsule specimens were evaluated histologically; macrophages, interleukin-6, and tumor necrosis factor-alpha were identified by use of immunocytochemical techniques. RESULTS: Compared with unaffected joints, macrophage density was increased in all affected joints. Duration of disease was significantly associated with radiographic severity of osteoarthritis and synovial macrophage density. Synovial macrophage density was significantly associated with severity of osteoarthritis and with the presence of interleukin-6 and tumor necrosis factor-a. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that synovial macrophages may be involved in the development of pathologic changes (including osteophyte formation) in the stifle joints of dogs with osteoarthritis secondary to rupture of the cranial cruciate ligament. Determination of the importance of synovial macrophages in the development of changes in osteoarthritic joints may result in new treatment strategies that involve elimination of the deleterious effects of those cells.

A preliminary study of intravenous surfactants in paraplegic dogs: polymer therapy in canine clinical SCI.

Hydrophilic polymers, both surfactants and triblock polymers, are known to seal defects in cell membranes. In previous experiments using laboratory animals, we have exploited this capability using polyethylene glycol (PEG) to repair spinal axons after severe, standardized spinal cord injury (SCI) in guinea pigs. Similar studies were conducted using a related co-polymer Poloxamer 188 (P 188). Here we carried out initial investigations of an intravenous application of PEG or P 188 (3500 Daltons, 30% w/w in saline; 2 mL/kg I.V. and 2 mL/kg body weight or 300 mL P 188 per kg, respectively) to neurologically complete cases of paraplegia in dogs. Our aim was to first determine if this is a clinically safe procedure in cases of severe naturally occurring SCI in dogs. Secondarily, we wanted to obtain preliminary evidence if this therapy could be of clinical benefit when compared to a larger number of similar, but historical, control cases. Strict entry criteria permitted recruitment of only neurologically complete paraplegic dogs into this study. Animals were treated by a combination of conventional and experimental techniques within approximately 72 h of admission for spinal trauma secondary to acute, explosive disk herniation. Outcome measures consisted of measurements of voluntary ambulation, deep and superficial pain perception, conscious proprioception in hindlimbs, and evoked potentials (somatosensory evoked potentials [SSEP]). We determined that polymer injection is a safe adjunct to the conventional management of severe neurological injury in dogs. We did not observe any unacceptable clinical response to polymer injection; there were no deaths, nor any other problem arising from, or associated with, the procedures. Outcome measures over the 6-8-week trial were improved by polymer injection when compared to historical cases. This recovery was unexpectedly rapid compared to these comparator groups. The results of this pilot trial provides evidence consistent with the notion that the injection of inorganic polymers in acute neurotrauma may be a simple and useful intervention during the acute phase of the injury.

Lightning injury in an outdoor swine herd.

Three pigs, weighing 63 kg-70 kg each, from a group of 8 pigs in an outdoor pen that was struck by lightning were necropsied. All 3 pigs presented with hind limb paralysis. The only lesions identified were multiple fractures of the last (seventh) lumbar vertebral body and first sacral vertebral segment, with dorsal displacement of the sacrum and transection of the distal spinal cord and spinal nerves. Hemorrhages extended from the fracture sites into muscles immediately surrounding the lumbosacral junction and retroperitoneally into the pelvic cavity. These hemorrhages were not clearly visible until the pelvic region was dissected. Lesions commonly found in human lightning-strike victims were not present in these pigs. Because vertebral fractures may be the only lesions and may be grossly subtle in heavily muscled pigs, careful pelvic and vertebral dissection is recommended in cases of suspected lightning strike and electrocution.

Canine transitional cell carcinoma.

Transitional cell carcinoma (TCC) of the urinary bladder, the most common malignancy of the urinary tract in dogs, is challenging to both diagnose and treat effectively. The prevalence of this disease may be increasing. The etiology of canine TCC is likely multifactorial. Epidemiological studies of TCC in the dog have revealed a number of risk factors, including breed and female gender, as well as environmental factors, such as insecticide exposure. This tumor is difficult to remove surgically and responds poorly to chemotherapy. The efficacy of radiotherapy and other treatment modalities needs further investigation. Cyclooxygenase-inhibiting drugs have some activity against TCC, and studies to further define these effects are ongoing. Use of the tumor/node/ metastasis (TNM) classification scheme for bladder cancer has allowed for the identification of prognostic factors. Urinary tract obstruction and metastatic disease remain challenges to treat. Work with canine TCC has demonstrated how closely this disease resembles human invasive urinary bladder cancer. Therefore, future research has the potential to benefit both dogs and humans with TCC.

Evaluation of treatment with doxorubicin and piroxicam or doxorubicin alone for multicentric lymphoma in dogs.

OBJECTIVE: To evaluate the antitumor and toxic effects of treatment with doxorubicin combined with piroxicam or doxorubicin alone for multicentric lymphoma in dogs. DESIGN: Nonrandomized clinical trial. ANIMALS: 75 dogs with multicentric lymphoma. PROCEDURE: 33 dogs were treated with doxorubicin (30 mg/m2, IV, q 21 d, for 3 doses) and piroxicam (0.3 mg/kg [0.14 mg/lb], PO, q 24 h); results were compared with a historical control group of 42 dogs treated with doxorubicin (30 mg/M2, IV, q 21 d, for 3 doses) alone. Results-The percentages of dogs that had remission with doxorubicin-piroxicam treatment (79%) or doxorubicin treatment alone (74%) were not significantly different. Median duration of first remission was 130 days with doxorubicin-piroxicam and 147 days with doxorubicin alone; these values were not significantly different. Severe toxicosis was observed in 22% of dogs treated with doxorubicin-piroxicam and 17% of dogs treated with doxorubicin alone. CONCLUSIONS AND CLINICAL RELEVANCE: Both treatment protocols were efficacious and well tolerated. The doxorubicin-piroxicam treatment was no more effective regarding response rate, remission duration, or survival duration, compared with the control group treated with doxorubicin alone.

Accuracy of three-dimensional and two-dimensional ultrasonography for measurement of tumor volume in dogs with transitional cell carcinoma of the urinary bladder.

OBJECTIVE: To determine the accuracy of 3-D and 2-D ultrasonography for quantification of tumor volume in dogs with transitional cell carcinoma (TCC) of the urinary bladder. ANIMALS: 10 dogs with biopsy-confirmed TCC. PROCEDURES: The urinary bladder of each dog was distended with saline (0.9% NaCl) solution (5.0 mL/kg), and masses were measured via 3-D and 2-D ultrasonography. Masses were also measured via 3-D ultrasonography after bladders were distended with 2.5 and 1.0 mL of saline solution/kg. Subsequently, the bladder was deflated and distended with CO(2) (5.0 mL/kg); CT was performed after IV contrast medium administration. Tumor volumes were calculated via 3-D ultrasonography, 2-D ultrasonography, and CT (reference method) and compared via ANOVA, Deming regression, and Bland-Altman plots. Repeated-measures ANOVA was used to assess effects of bladder distension on 3-D tumor volume measurements. Repeatability of measurements was estimated via the coefficient of variation for each method. RESULTS: Repeatability was considered good for all 3 methods. There was no significant difference in tumor volume measurements obtained via 3-D ultrasonography at different degrees of urinary bladder distension. Results of Deming regression and Bland-Altman plots indicated excellent agreement between tumor volume measurement with 3-D ultrasonography and CT, but not between 2-D ultrasonography and CT. CONCLUSIONS AND CLINICAL RELEVANCE: Tumor volume in dogs with TCC of the urinary bladder was accurately measured via 3-D ultrasonography. Use of 3-D ultrasonography can provide a less expensive and more practical method for monitoring response to treatment than CT and was more accurate than 2-D ultrasonography.

Usefulness of a half-fourier acquisition single-shot turbo spin-echo pulse sequence in identifying arachnoid diverticula in dogs.

Single-shot turbo spin-echo sequences are heavily T2-weighted sequences that are exceptionally well suited to evaluate the subarachnoid space. In the T2-weighted fast spin-echo sequences that are used routinely in spinal magnetic resonance (MR) imaging, the subarachnoid space is not well differentiated from the surrounding epidural fat, which could lead to decreased detection of lesions of the subarachnoid space such as arachnoid diverticula. Our purpose was to determine the added value of a single-shot turbo spin-echo sequence in identifying cystic lesions of the subarachnoid space in dogs. MR images of six dogs with a confirmed arachnoid diverticulum and 24 dogs with other spinal disease were included. Six observers were asked to interpret only T2-weighted images initially, and in a second session, T2-weighted and half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences. The MR images were anonymized, and no signalment, history, or clinical information was provided. Without the HASTE sequences, 25% of arachnoid diverticula were identified. Adding the HASTE sequence increased the diagnosis of arachnoid diverticulum to 52.8%. The resulting difference, after adding the HASTE sequence, of 27.8% was statistically significant (P = 0.002). No false-positive diagnoses of arachnoid diverticulum were made with either sequence. Although sensitivity in this study was likely artificially low, the significantly increased detection rate of arachnoid diverticula when using HASTE imaging indicates that this sequence is a valuable addition to MR imaging protocols for the canine spine.

Antitumor effects of deracoxib treatment in 26 dogs with transitional cell carcinoma of the urinary bladder.

OBJECTIVE-To evaluate the antitumor activity and toxic effects of deracoxib, a selective cyclooxygenase-2 inhibitor, in dogs with transitional cell carcinoma (TCC) of the urinary bladder. DESIGN-Clinical trial. Animals-26 client-owned dogs with naturally occurring, histologically confirmed, measurableTCC of the urinary bladder. PROCEDURES-Dogs were treated PO with deracoxib at a dosage of 3 mg/kg/d (1.36 mg/lb/d) as a single-agent treatment for TCC. Tumor response was assessed via radiography, abdominal ultrasonography, and ultrasonographic mapping of urinary bladder masses. Toxic effects of deracoxib administration in dogs were assessed through clinical observations and hematologic and biochemical analyses. RESULTS-Of 24 dogs for which tumor response was assessed, 4 (17%) had partial remission, 17 (71%) had stable disease, and 3 (13%) had progressive disease; initial response could not be assessed in 2 of 26 dogs. The median survival time was 323 days. Median time to progressive disease was 133 days. Renal, hepatic, and gastrointestinal abnormalities attributed to deracoxib administration were noted in 4% (1/26), 4% (1/26), and 19% (5/26) of dogs, respectively. CONCLUSIONS AND CLINICAL RELEVANCE-Results indicated that deracoxib was generally well tolerated by dogs and had antitumor activity against TCC.

Appearance of common ultrasound artifacts in conventional vs. spatial compound imaging.

Abdominal sonographic artifacts produced by conventional and spatial compound sonographic imaging using linear and curved array transducers were compared. Spatial compound imaging produced multiple diverging ring-down artifacts from a single source with increasing width and decreasing intensity. Overlap of the diverging artifacts was conspicuous when the focal point was in the far field. Increased width and reduced intensity of acoustic shadowing artifacts was observed with spatial compound imaging. Edge shadowing was eliminated, or reduced. Diverging edge shadowing from the source of the artifact with reduced intensity was detected when the focal point was in the near field. There was no apparent difference of the acoustic enhancement artifact with spatial compound imaging. There was absence or reduction of clutter seen in the urinary bladder when using spatial compound imaging. The appearance of artifacts with spatial compound imaging is slightly different from those with conventional ultrasound imaging.

Acquisition hardware for digital imaging.

Use of digital radiography is growing rapidly in veterinary medicine. Two basic digital imaging systems are available, computed radiography (CR) and direct digital radiography (DDR). Computed radiographic detectors use a two-step process for image capture and processing. Image capture is by X-ray sensitive phosphors in the image plate. The image plate reader transforms the latent phosphor image to light photons that are converted to an analog electrical signal. An analog to digital converter is used to digitize the electrical signal before computer analysis. Direct digital detectors provide digital data by direct readout after image capture--a reader unnecessary. Types of DDR detectors are flat panel detectors and charge coupled device (CCD) detectors. Flat panel detectors are composed of layers of semiconductors for image capture with transistor and microscopic circuitry embedded in a pixel array. Direct converting flat panel detectors convert incident X-rays directly into electrical charges. Indirect detectors convert X-rays to visible light, then to electrical charges. All flat panel detectors send a digitized electrical signal to a computer using a direct link. Charge coupled device detectors have a small chip similar to those used in digital cameras. A scintillator first converts X-rays to a light signal that is minified by an optical system before reaching the chip. The chip sends a digital signal directly to a computer. Both CR and DDR provide quality diagnostic images. CR is a mature technology while DDR is an emerging technology.

Folate-targeted immunotherapy effectively treats established adjuvant and collagen-induced arthritis.

Activated macrophages express a cell surface receptor for the vitamin folic acid. Because this receptor is inaccessible or not measurably expressed on other normal cells, folic acid has been recently exploited to selectively deliver attached radio-emitters to sites of activated macrophage accumulation, allowing scintigraphic imaging of inflamed joints and organs of arthritic rats. We demonstrate here that folate-linked haptens can also be targeted to activated macrophages, decorating their cell surfaces with highly immunogenic molecules. Under conditions in which the rodent has already been immunized against keyhole limpet hemocyanine-(fluorescein isothiocyanate) FITC, activated macrophages are eliminated. Administration of folate-FITC conjugates to rodents with experimental arthritis attenuates (a) systemic and peri-articular inflammation, (b) bone and cartilage degradation, and (c) arthritis-related body weight loss. Treatment with folate-hapten conjugates is comparable to methotrexate, etanercept, anakinra, and celecoxib at alleviating the symptoms of arthritis. We conclude that reduction of activated macrophages by folate-targeted immunotherapy can ameliorate the symptoms of arthritis in two rodent models of the disease.

Cerebrospinal fluid response following metrizamide myelography in normal dogs: effects of routine myelography and postmyelographic removal of contrast medium.

The effect of metrizamide myelography on 90-minute postmyelographic cerebrospinal fluid (CSF) samples was evaluated in a paired crossover study in 16 normal dogs. Each dog received a routine cervical myelogram (nonwithdrawal myelography) and a myelogram followed by contrast medium removal via aspiration from the subarachnoid space (withdrawal myelogram). Following nonwithdrawal myelography, the CSF was characterized by mild inflammation with a mixed pleocytosis and increased protein concentration. Compared with the nonwithdrawal CSF samples, the postmyelographic CSF of the withdrawal dogs had a more severe inflammatory response with significant increases (p < 0.05) in absolute numbers of neutrophils, monocytoid cells, eosinophils, lymphocytes, and protein concentration. The withdrawal procedure may have contributed an additional mechanical effect on the leptomeninges producing the more severe inflammatory response in the withdrawal dogs. Although seizure data are not reported here, postmyelographic seizures were more frequent following non-withdrawal myelography as compared with withdrawal myelography (p < 0.05), suggesting a decrease in metrizamide-induced neurotoxicity for the withdrawal dogs.

Babesia gibsoni infection in a dog from indiana.

A 10-year-old spayed female mixed-breed dog was presented to the Purdue University Veterinary Teaching Hospital (PUVTH) with complaints of persistent anemia with occasional exacerbations, anorexia, and lethargy. The dog had been presented to the referring veterinarian 2 months prior with multiple bite wounds received during a fight with 3 Pit Bull Terriers. The dog was discharged after the wounds were cleaned and surgically closed. Upon admission to the PUVTH, blood was collected for a complete blood count and biochemical analysis. Microscopic examination of peripheral blood smears revealed intraerythrocytic protozoal parasites consistent with Babesia gibsoni. Molecular analysis confirmed that the organism was B. gibsoni and that its 18S ribosomal RNA sequence was identical to that of other B. gibsoni isolates from Oklahoma, North Carolina, and Okinawa, Japan. Hematologic changes included moderately severe, regenerative, macrocytic, normochromic anemia, with poikilocytosis, polychromasia, anisocytosis, and a marked increase in nucleated RBCs. Biochemical changes included increased serum alanine aminotransferase, alkaline phosphatase, and gamma-glutamyltransferase activities. The dog was treated with imidocarb, but despite initial clinical improvement, the dog died 2 weeks after the first dose. A necropsy was not performed. The infection in this dog is the first reported case of B. gibsoni infection in Indiana. Because of the widespread geographical distribution of the organism, veterinarians and veterinary clinical pathologists throughout the United States should carefully examine Romanowsky-stained blood smears from patients with acute hemolytic anemia for small intraerythrocytic babesial parasites.

Folate-targeted imaging of activated macrophages in rats with adjuvant-induced arthritis.

OBJECTIVE: To determine whether overexpression of the high-affinity folate receptor (FR) on activated macrophages can be exploited to selectively target imaging agents to sites of inflammation in rats with adjuvant-induced arthritis (AIA). METHODS: Folic acid was conjugated to a (99m)Tc chelator (the complex termed EC20), and its distribution was visualized using gamma scintigraphy in healthy rats, rats with AIA, and arthritic rats that had been depleted of macrophages. To confirm that uptake was mediated by the FR, excess folic acid competition studies were conducted, and tissue FR levels were quantitated using a radioligand binding assay. Flow cytometry was also used to investigate uptake of folate conjugates into macrophages of both arthritic and healthy rats. RESULTS: EC20 concentrated in the arthritic extremities of diseased rats but not in the extremities of healthy rats. The intensity of images of affected tissues was greatly reduced in the presence of excess competing folic acid. The livers and spleens of arthritic animals also showed enhanced uptake of EC20 and increased levels of FR. Depletion of macrophages from arthritic animals reduced tissue FR content and concomitantly abolished uptake of EC20. In addition, macrophages isolated from livers of rats with AIA exhibited a significantly higher binding capacity for folate conjugates than did macrophages obtained from healthy rats. CONCLUSION: Although EC20 is currently undergoing clinical evaluation for use in the imaging of ovarian carcinomas, the present results suggest that it may also be useful for assaying the participation of activated macrophages in inflammatory processes such as rheumatoid arthritis.