Urethral pressure profiles (UPPs) were recorded in ten adult healthy male cats before and after administration of either phenoxybenzamine, diazepam, nifedipine or xylazine. A significant decrease (p < 0.05) in urethral pressure at the level of the prostate was observed following treatment with all drugs. Xylazine produced a significant decrease in urethral pressure 4 to 7 cm from the tip of the penis in healthy male cats. None of the drugs used decreased urethral pressure in the zones of pure striated muscle or pure smooth muscle in these cats, making current recommendations for pharmacological management of urethral spasm suspect. Further studies are necessary to evaluate clinical cases of urethral spasm and to study the effects of these drugs on the urethral pressure of cats suffering from this spasm.

Total protein concentration was determined in serum, bronchoalveolar lavage (BAL) fluid, and nasal flush fluid obtained from specific-pathogen-free cats from birth to maturity and from adult conventionally raised cats. Protein components were analyzed by immunoelectrophoresis and isoelectric focusing. Albumin, and alpha, beta, and gamma-globulins were among the proteins identified in BAL fluid, and their isoelectric point ranged from 3.1 to 5.1. gamma-Globulin was not detected in serum or BAL fluid of newborn kittens before they had ingested colostrum. By day 3 after ingestion of colostrum, IgG was detected in high concentration in serum and was the predominant immunoglobulin in serum and BAL fluid of older cats. Nasal flush fluid from cats > 6 months old contained albumin, and alpha, beta, and gamma-globulins, with IgA being the predominant immunoglobulin. Total protein concentration in nasal flush fluid increased progressively with increasing age, and albumin was the predominant protein. Protein concentration was significantly (P < 0.01) higher in BAL fluid from conventionally raised adult cats than in that from specific-pathogen-free cats.

Bovine whey samples were evaluated by use of lymphocyte-transformation tests to determine their effect on lymphocyte blastogenesis. Whey samples from mammary glands with clinical mastitis strongly inhibited DNA synthesis and blastogenesis in lymphocytes stimulated with mitogens or dividing because of bovine leukemia virus infection. Whey samples from apparently healthy glands either did not inhibit lymphocyte DNA synthesis or inhibited it to a lesser degree than did whey from mastitic glands. Degree of inhibition was dose-dependent. The molecules causing inhibition were noncytotoxic and underwent minimal binding to the lymphocytes. Inhibitory molecules were susceptible to various proteolytic and glycolytic enzymes, indicating a glycoprotein-like structure. Whey inhibited incorporation of thymidine if it was in the cell cultures during the early stages of stimulation. Incubation of lymphocytes in whey that inhibited thymidine incorporation did not affect DNA synthesis in subsequent culturing of the same cells without whey. Degree of inhibition was affected by the method of whey preparation.

To determine the role of thromboxane A2 in the pathogenesis of experimentally induced immune complex glomerulonephritis, 12 concanavalin A-immunized Beagles were infused with 1 mg of concanavalin A via each renal artery and treated twice daily for 8 days with either 30 mg of CGS 12970/kg, PO, a specific thromboxane synthetase inhibitor, or placebo. The effect of treatment was assessed by measuring endogenous creatinine clearance and urine protein and eicosanoid excretion, and by evaluating changes in glomerular morphometric characteristics. On postinfusion day 8, urine protein, thromboxane B2, and 11-dehydro-thromboxane B2 excretion, glomerular epithelial crescent formation, and glomerular cell proliferation in the CGS 12970-treated dogs were significantly decreased when compared with values in the placebo-treated group. Differences were not observed in endogenous creatinine clearance, urine prostaglandin E2 and 6-keto-prostaglandin F1 alpha excretion, or glomerular polymorphonuclear leukocyte infiltration between groups in this study. These findings suggest thromboxane A2 has a role in the development of immune complex glomerulonephritis and that thromboxane synthetase inhibition may be beneficial in attenuating some of the functional and histologic changes associated with immune complex glomerulonephritis.

Tissues from cattle that died of experimentally induced mucosal disease (n = 3), naturally acquired mucosal disease (n = 6), or naturally acquired chronic bovine viral diarrhea (n = 4) were examined. Consistent findings were lymphocytic depletion of lymphoid tissues, degeneration of myenteric ganglion cells, and mild adrenalitis. Intracytoplasmic viral antigen was detected in myenteric ganglia and in endocrine glandular cells. Noncytopathic virus was isolated from all cattle, and cytopathic virus was isolated from 12 of 13 cattle.

Fourteen adult beavers (Castor canadensis) weighing 16.5 +/- 4.14 kg (mean +/- SD) were anesthetized for surgical implantation of radio telemetry devices. Beavers were anesthetized with diazepam (0.1 mg/kg) and ketamine (25 mg/kg) administered IM, which provided smooth anesthetic induction and facilitated tracheal intubation. Anesthesia was maintained with halothane in oxygen via a semiclosed circle anesthetic circuit. Values for heart rate, respiratory rate, esophageal temperature, direct arterial blood pressure, end-tidal halothane concentration, and end-tidal CO2 tension were recorded every 15 minutes during the surgical procedure. Arterial blood samples were collected every 30 minutes to determine pH, PaO2, and PaCO2. Values for plasma bicarbonate, total CO2, and base excess were calculated. Ventilation was spontaneous in 7 beavers and controlled to maintain normocapnia (PaCO2 approx 40 mm of Hg) in 7 others. Vaporizer settings were adjusted to maintain a light surgical plane of anesthesia. Throughout the surgical procedure, all beavers had mean arterial pressure < 60 mm of Hg and esophageal temperature < 35 C. Mean values for arterial pH, end-tidal CO2, PaO2, and PaCO2 were significantly (P < 0.05) different in spontaneously ventilating beavers, compared with those in which ventilation was controlled. Respiratory acidosis during halothane anesthesia was observed in spontaneously ventilating beavers, but not in beavers maintained with controlled ventilation. All beavers recovered unremarkably from anesthesia.

Hepatic abscesses were induced experimentally in 5 steers by inoculating Fusobacterium necrophorum via ultrasonography-guided, percutaneous catheterization of the portal vein. Hepatic ultrasonography was performed to determine the onset and progression of abscessation. Blood samples were collected before and after inoculation for performing leukocyte counts and hepatic function tests. Ultrasonographic evidence of liver abscesses was observed as early as 3 days after inoculation. Abscesses appeared as hyperechoic centers (cellular debris and pus) surrounded by hypoechoic or anechoic areas (fluid). Increases in rectal temperature, leukocyte counts, fibrinogen, globulin, bilirubin, gamma-glutamyltransferase, and sorbitol dehydrogenase concentrations were detected. Hepatic dysfunction was evidenced by decrease in serum albumin concentration and low sulfobromophthalein clearance. The ultrasonographic diagnosis of abscesses correlated well with necropsy findings.

During this investigation, the use of iohexol was compared with iotrolan for canine cisternal myelography. Iohexol and iotrolan myelography was done in 6 dogs by cisternal puncture with a 6-week interval between both procedures; each dog served as its own control. Cerebrospinal fluid (CSF) was collected for baseline analysis from each dog immediately before the contrast agent was injected. Cerebrospinal fluid samples were obtained at 1, 3, 7, and 14 days after injection of each contrast medium for cytologic and chemical analysis. Total CSF leucocyte count and glucose concentration did not change significantly in comparison with baseline data in any of the samples. After the injection of iohexol, protein concentration increased significantly in the 24-hour sample, and lactate dehydrogenase activity increased significantly in the 3-day sample. Significant difference was not found between the different samples collected at 1, 3, 7, and 14 days, compared with both contrast media. None of the dogs had seizure activity during a 5-hour postmyelographic observation period. Pathologic changes were not found by gross or microscopic examination of the spinal cord. Although a degradation in time of radiographic quality of all myelograms took place, the average radiographic score decreased more rapidly with iohexol. The average score at 90 minutes with iotrolan was comparable with the score at 45 minutes with iohexol, and the average score at 150 minutes with iotrolan was better than the score at 90 minutes with iohexol. At 5 and 10 minutes after cisternal injection, no significant difference wasobservable between the myelograms, but from 45 minutes onward, myelograms with iotrolan were superior.

Plasma concentrations of porcine growth hormone (PGH) were similar in healthy pigs and those with atrophic rhinitis (AR), therefore, observed reduced growth rates and feed efficiency in naturally infected pigs with AR were not attributed to low concentrations of plasma PGH. Also, pituitary glands in both groups of pigs were responsive to growth hormone-releasing hormone (GHRH) challenge by increasing PGH secretion. Administration of clonidine hydrochloride to pigs naturally infected with AR failed to elicit any significant change (5.3 +/- 1.4 ng/ml) in the plasma concentration of PGH within a 45-minute bleeding interval. The pretreatment concentrations of PGH were similar in specific-pathogen-free toxin-treated and specific-pathogen-free control groups, but they increased significantly in toxin-treated pigs (20.7 +/- 8.2 ng/ml) within 15 minutes after GHRH injection. Porcine growth hormone release in toxin-treated pigs was variable; however, all pigs did not respond to GHRH administration: 3 responded with an increase in PGH release (35.6 +/- 10.6 ng/ml), 2 did not respond (6.7 +/- 0.5 ng/ml), and 1 had a decrease in PGH release (3.9 ng/ml). Therefore, the observed reduced growth rates reported in the literature may be attributed to factors at the target level of PGH action, such as insufficient or down-regulation of PGH receptors, changes or impaired ability in the PGH receptor-binding characteristics, and inability of PGH receptor complex to transduce signal. Toxins are known to modulate signal transduction pathways. It has been speculated that serotype-D Pasteurella multocida toxin may influence growth by its effect on signal transduction from PGH receptor complex on the cell membrane to the interior of the cell. This would account for the presence of high concentrations of PGH in the plasma and a functionally competent hypophysis cerebri, which responded to GHRH injection that have retarded growth in pigs affected with AR.

The effect of a passive heat and moisture exchanger on tracheal and large airway temperature, as reflected by esophageal temperature at the thoracic inlet, was determined for 12 anesthetized and ventilated tumor-bearing dogs undergoing whole-body hyperthermia at 42 C. Delivered thermal dose to the esophagus and rectum during 120 minutes of whole-body hyperthermia was quantified as the thermal dose summary measure EQ43. The heat and moisture exchanger significantly increased esophageal EQ43 from 7.3 minutes to 12.1 minutes. Esophageal EQ43, however, remained lower than rectal EQ43. Although use of a heat and moisture exchanger improved esophageal temperature during whole-body hyperthermia, presumably through improved airway temperature, additional methods will be necessary to increase esophageal and airway temperature to the target value of 42 C.