Flunixin meglumine attenuation of endotoxin-induced damage to the cardiopulmonary vascular endothelium of the pony

Endotoxic shock was induced in 5 ponies by intraperitoneal injections of 20, 40, 60, 80, and 80 micrograms of Escherichia coli endotoxin (LPS)/kg of body weight at 0, 6, 12, 18, and 24 hours, respectively. At 24 hours, the ponies also were given 20 micrograms of LPS/kg via catheter in the left ventricle of the heart. A 2nd group of 4 ponies was given 1.1 mg of flunixin meglumine (FM)/kg, IV, at 6, 12, 18, and 24 hours just before the corresponding LPS injection. Two hours after the 24-hour LPS injection, the ponies in both groups were anesthetized, the lungs were perfused with fixative, and portions of the pulmonary arteries and veins and right and left ventricles were prepared for scanning and transmission electron microscopy. In ponies that were given only LPS, some areas of pulmonary vascular endothelium appeared normal when compared with untreated controls, but other areas had disoriented endothelial cells or had varying amounts of sloughing, which ranged from focal areas of a few cells to large areas of denuded endothelium. Ponies treated with FM before LPS had less severe and less extensive endothelial cell damage. In both groups, leukocytes were attached to areas of the vessel wall; endothelial cell damage was greater in these regions. Administration of FM before LPS administration attenuated the LPS-induced endothelial cell damage.     

Hemodynamics, plasma eicosanoid concentrations, and plasma biochemical changes in calves given multiple injections of Escherichia coli endotoxin

Twelve male neonatal calves (39 to 50 kg) were allotted to 3 groups of 4 calves each. All calves were anesthetized with halothane, and then Escherichia coli endotoxin was given intravenously (3 times) and intraperitoneally (3 times) during a 6-hour period. Group-1 calves were untreated, group-2 calves were pretreated with a low dose of flunixin meglumine (1.1 mg/kg of body weight), and group-3 calves were pretreated with a high dose of flunixin meglumine (4.4 mg/kg). In calves of group 1, the mean systemic arterial blood pressure (MABP) and cardiac output (CO) decreased, but pulmonary arterial pressure increased after the initial intravenous and intraperitoneal injections of endotoxin. In calves of this group, these changes were accompanied by increased plasma thromboxane B2 (TxB2) concentration. During this period, increased plasma TxB2 concentration or hemodynamic changes were not detected in calves of groups 2 and 3. Only calves of group 1 had altered hemodynamics early in the experiment; however, after 6 hours, calves of all 3 groups had similarly decreased CO and MABP. In calves of the untreated group, plasma 6-keto-prostaglandin (PG)F1 alpha concentration increased steadily from the beginning of the experiment until 3 hours later. The CO and MABP were low at the time when serum 6-keto-PGF1 alpha concentration was high; however, these 2 measurements also were low in treated calves who did not have correspondingly high plasma 6-keto-PGF1 alpha concentration. Regional blood flow analysis did not reveal correlations between prostanoid concentrations and altered blood flow to selected tissues.(ABSTRACT TRUNCATED AT 250 WORDS)     

Etiologic studies on late-term swine abortions

One hundred thirty-eight swine abortions were studied in detail in an effort to identify an etiologic agent. A viral agent was implicated in 7 cases. Bacteria were isolated in less than half of the examined cases: however, in 61% of the cases, motile, filamentous organisms were observed in tissues and fluids. Although swine sera from farms experiencing reproductive problems had a high reactor rate to Leptospira bratislava antigen, electron microscopy of the observed organism revealed a wall-free prokaryote morphologically typical of the class Mollicutes.     

Equine endothelial cells in vitro

Certain in vitro culture conditions were determined for equine endothelial cells obtained from the aorta and pulmonary arteries. Cells were enzymatically isolated from the vessel lumen, using clostridial collagenase (2.5 mg/ml of Hanks's balanced salt solution) incubated at 37 C for 30 minutes. Cells were cultured in alpha minimum essential medium supplemented with plasma-derived and nonplasma-derived bovine fetal sera, endothelial cell-growth supplement, heparin, and antibiotics. Smooth muscle cell growth was not inhibited with nonplasma-derived animal sera, plasma-derived equine serum, or heparin. Heparin and a serum replacement were toxic to the cells used in the present study. Statistically significant differences were not found between the various media supplements.     

Does l‐Asparaginase Influence Efficacy or Toxicity When Added to a Standard CHOP Protocol for Dogs with Lymphoma?

The purpose of this study was to evaluate response rates, 1st remission duration (FRD), and toxicity in dogs with previously untreated lymphoma receiving an identical CHOP-based combination chemotherapy protocol with or without L-asparaginase (LASP). One hundred fifteen dogs with lymphoma were scheduled to receive an identical CHOP-based chemotherapy protocol that included L-ASP. However, because of manufacturer-imposed random rationing, 31 dogs did not receive L-ASP as scheduled. The 2 treatment groups were statistically similar with respect to signalment and presence of historical negative prognostic factors. No difference was observed in the median FRD whether dogs did or did not receive L-ASP (206 versus 217 days, respectively; P = .67). No difference was observed in the median overall survival times between dogs receiving or not receiving L-ASP (310 versus 308 days, respectively; P = .84). No statistical difference was observed with respect to overall response rate between dogs that did or did not receive L-ASP (89.3% versus 87.1%, respectively; P = .75). Complete response rates between the groups also were no different (83.3% and 77.4% for L-ASP and non-L-ASP groups, respectively; P = .59). Prevalence of toxicity (neutropenia, diarrhea, or vomiting) and treatment delays (P = .80) also were similar between groups. The results of this study suggest that exclusion of L-ASP in this multidrug protocol does not significantly impact outcome. Therefore, it may be more appropriate to reserve the use of L-ASP for treating relapse in dogs with lymphoma that have failed induction therapy.     

Experimental evaluation of rainbow trout Oncorhynchus mykiss predation on longnose dace Rhinichthys cataractae

Laboratory and in‐stream enclosure experiments were used to determine whether rainbow trout Oncorhynchus mykiss influence survival of longnose dace Rhinichthys cataractae. In the laboratory, adult rainbow trout preyed on longnose dace in 42% of trials and juvenile rainbow trout did not prey on longnose dace during the first 6 h after rainbow trout introduction. Survival of longnose dace did not differ in the presence of adult rainbow trout previously exposed to active prey and those not previously exposed to active prey ( = 0.28, P = 0.60). In field enclosures, the number of longnose dace decreased at a faster rate in the presence of rainbow trout relative to controls within the first 72 h, but did not differ between moderate and high densities of rainbow trout (F_2,258.9 = 3.73, P = 0.03). Additionally, longnose dace were found in 7% of rainbow trout stomachs after 72 h in enclosures. Rainbow trout acclimated to the stream for longer periods had a greater initial influence on the number of longnose dace remaining in enclosures relative to those acclimated for shorter periods regardless of rainbow trout density treatment (F_4,148.5 = 2.50, P = 0.04). More research is needed to determine how predation rates will change in natural environments, under differing amounts of habitat and food resources and in the context of whole assemblages. However, if rainbow trout are introduced into the habitat of longnose dace, some predation on longnose dace is expected, even when rainbow trout have no previous experience with active prey.     

Definitive‐intent intensity‐modulated radiation therapy provides similar outcomes to those previously published for definitive‐intent three‐dimensional conformal radiation therapy in dogs with primary brain tumors: A multi‐institutional retrospective study

Radiotherapy with or without surgery is a common choice for brain tumors in dogs. Although numerous studies have evaluated use of three‐dimensional conformal radiotherapy, reports of definitive‐intent, IMRT for canine intracranial tumors are lacking. Intensity‐modulated radiation therapy has the benefit of decreasing dose to nearby organs at risk and may aid in reducing toxicity. However, increasing dose conformity with IMRT calls for accurate target delineation and daily patient positioning, in order to decrease the risk of a geographic miss. To determine survival outcome and toxicity, we performed a multi‐institutional retrospective observational study evaluating dogs with brain tumors treated with IMRT. Fifty‐two dogs treated with fractionated, definitive‐intent IMRT at four academic radiotherapy facilities were included. All dogs presented with neurologic signs and were diagnosed via MRI. Presumed radiological diagnoses included 37 meningiomas, 12 gliomas, and one peripheral nerve sheath tumor. One dog had two presumed meningiomas and one dog had either a glioma or meningioma. All dogs were treated in the macroscopic disease setting and were prescribed a total dose of 45‐50 Gy (2.25‐2.5 Gy per fraction in 18‐20 daily fractions). Median survival time for all patients, including seven cases treated with a second course of therapy was 18.1 months (95% confidence of interval 12.3‐26.6 months). As previously described for brain tumors, increasing severity of neurologic signs at diagnosis was associated with a worse outcome. Intensity‐modulated radiation therapy was well tolerated with few reported acute, acute delayed, or late side effects.     

A neoplasm of globule leukocytes in a cat

A neoplasm involving the ileo-cecal-colic junction, thymus, and tracheobronchial lymph nodes of a 7-year-old domestic cat was composed of dense sheets of round to oval mononuclear cells with oval to indented nuclei, moderate amounts of cytoplasm, and variable numbers of round eosinophilic granules. These granules are brown to black in phosphotungstic acid hematoxylin-stained sections and stain variably with the periodic acid-Schiff stain. They are 0.8 to 1.5 micron in diameter, limited by a single unit membrane, and have variable electron density. Light microscopic cellular morphology and staining characteristics as well as ultrastructural features of these cells are consistent with feline globule leukocytes. Morphologic features of the neoplastic cells in the present case are similar to those of the only other reported neoplasm of globule leukocytes which also involved the intestine of a cat.     

IMAGING DIAGNOSIS—MAGNETIC RESONANCE IMAGING OF A NEURONAL HETEROTOPIA IN THE BRAIN OF A CAT

A domestic shorthair kitten was presented for evaluation and further treatment of seizures. Magnetic resonance imaging of the brain revealed a large multilobulated mass in the third ventricle extending into the right lateral ventricle with secondary obstructive hydrocephalus. The mass was homogeneously isointense to gray matter on T2W, T2‐FLAIR, T2^*W, T1W, and ADC images, and hyperintense on DW‐EPI. There was no appreciable contrast enhancement. Seizures were managed medically and with subsequent ventriculoperitoneal shunt placement. Clinical status later deteriorated and the cat was euthanized. Histopathology confirmed that the mass was the result of neuronal heterotopia. To the authors’ knowledge this is the first report of neuronal heterotopia in a cat.     

Outcome and prognostic factors following adjuvant prednisone/vinblastine chemotherapy for high-risk canine mast cell tumour: 61 cases

The medical records of 61 dogs with MCT at high risk for metastasis that were treated with prednisone and VBL following excision+/-radiation therapy were reviewed, and median disease-free interval (DFI), median overall survival time (OS) and prognostic factors assessed. Adverse effects, mostly mild, were noted in 26% of patients, usually after the first VBL dose. 6.5% experienced severe neutropenia. The DFI was 1305 days, and the OS was not reached, with 65% alive at 3 years. 100% of dogs with "high-risk" grade II MCT were alive at 3 years. The OS for dogs with grade III MCT was 1374 days. Histologic grade, location (mucous membrane vs. skin) and use of prophylactic nodal irradiation predicted outcome. Prednisone and VBL chemotherapy is well tolerated, and results in good outcomes following surgery in dogs with MCT at high risk for metastasis. High-grade and mucocutaneous tumors had a worse outcome, and the use of prophylactic nodal irradiation appeared to improve outcome in this group of dogs.