Postoperative hypoxemia and hypercarbia in healthy dogs undergoing routine ovariohysterectomy or castration and receiving butorphanol or hydromorphone for analgesia

OBJECTIVE: To determine frequency and severity of postanesthetic hypoxemia and hypercarbia in healthy dogs undergoing elective ovariohysterectomy or castration and given butorphanol or hydromorphone for analgesia. DESIGN: Prospective trial. ANIMALS: 0 healthy dogs weighing > 10 kg (22 lb). PROCEDURE: Dogs were anesthestized with acepromazine, glycopyrrolate, thiopental, and isoflurane, and butorphanol (n = 10) or hydromorphone (10) was used for perioperative analgesia. Arterial blood gas analyses were performed 10 and 30 minutes and 1, 2, 3, and 4 hours after extubation. RESULTS: In dogs that received hydromorphone, mean PaCO2 was significantly higher, compared with the preoperative value, 10 and 30 minutes and 1, 2, and 3 hours after extubation. Mean PaCO2 was significantly higher in dogs given hydromorphone rather than butorphanol 10 and 30 minutes and 1 and 2 hours after extubation. Mean PaO2 was significantly lower, compared with preoperative values, 30 minutes and 1 and 2 hours after extubation in dogs given hydromorphone and 30 minutes after extubation in dogs given butorphanol. Mean PaO2 was significantly lower in dogs given hydromorphone rather than butorphanol 1 hour after extubation. Four dogs had PaO2 < 80 mm Hg 1 or more times after extubation. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that administration of hydromorphone to healthy dogs undergoing elective ovariohysterectomy or castration may result in transient increases in PaCO2 postoperatively and that administration of hydromorphone or butorphanol may result in transient decreases in PaO2. However, increases in PaCO2 and decreases in PaO2 were mild, and mean PaCO2 and PaO2 remained within reference limits.     

Fractional factorial design of screening experiments on cryopreservation of fish sperm

Milt of grass carp Ctenopharyngodon idella (Val.) and goldfish Carassius auratus auratus (L.) was cryopreserved in experiments following &Hf;1 2 and &Hf;1 4 fractional factorial designs. The efficiency of a graphical method and manova was tested, as well as the informative strength of both designs. Fractional factorial design was very suitable for screening experiments, and it allowed separation of important and unimportant effects. A graphical method showed the same efficiency and reliability as manova . The &Hf;1 4 fractional factorial design was less informative than the &Hf;1 2 fractional factorial design, because it did not allow an estimation of the interactions. The application of fractional factorial designs for multifactorial screening experiments on cryopreservation of fish sperm has been implemented in this study.     

Isoproterenol- and salbutamol-induced relaxation of acetylcholine- and histamine-induced contraction of equine trachealis muscle in vitro

Strips of trachealis muscle were dissected from the midcervical portion of the trachea of horses that were free of respiratory tract disease, and the overlying epithelium and mucosa were removed. Muscle strips were suspended in tissue baths that were filled with Krebs-bicarbonate solution, aerated with 5% CO2 in oxygen and maintained at 37 C. Isometric tension was continuously recorded. The increase in active isometric tension was concentration dependent when acetylcholine (10(-9) to 10(-4) M) or histamine (10(-9) to 10(-4) M) was added to the tissue baths in 0.5-logarithmic increments. When the tissues were contracted with acetylcholine (3.1 x 10(-6) M) or histamine (10(-4) M), the decrease in active isometric tension was concentration dependent when isoproterenol (10(-9) to 10(-4) M) or salbutamol (10(-9) to 10(-4) M) was added to the tissue baths in 0.5-logarithmic increments. There was no difference between the response to isoproterenol and salbutamol when tissues from the same horses were compared whether the tissues were contracted in response to acetylcholine (3.1 x 10(-6) M) or histamine (10(-4) M). Relaxation was antagonized by 10(-6) M propranolol. The degree of relaxation obtained in these muscle strips was considerably less than that reported from other species' tracheal muscle strips that had the epithelium and mucosa intact. We concluded that equine tracheal smooth muscle contains beta-adrenoceptors that can be stimulated by either a mixed beta-1, beta-2 agonist or a selective beta-2 agonist.     

Head blight and biosynthesis of Fusarium toxins in barley kernels field inoculated withFusarium culmorum

Heads of 12 spring barley genotypes (eight cultivars, four lines) were inoculated with conidial suspensions of twoFusarium culmorum isolates (I₁ and I₂). Both isolates caused the following significant reductions (%) when compared with the control: number of kernels head^–1 12 and 16, weight of 1000 kernels 47 and 24, yield 49 and 37, for I₁ and I₂ respectively. Both isolates were able to produce average levels (mg kg^–1) of deoxynivalenol of 67.1 and 13.9, 3-acetyldeoxynivalenol of 9.4 and 1.4 and zearalenone of 0.3 and 0.4 for I₁ and I₂ respectively. In kernels of three genotypes inoculated with the same isolates, 15-acetyldeoxynivalenol at an average level (mg kg^–1) of 1.3 and 1.5 was detected, while in kernels of six genotypes inoculated with I₂, 0.2 of nivalenol was found. A significant correlation for yield and toxin level was found for less pathogenicF. culmorum isolate I₂.     

Inhibition of Armillaria and Heterobasidion growth by Penicillium adametzii isolated from Pinus sylvestris forest soil

Penicillium adametzii significantly inhibited the growth of Heterobasidium annosum sensu stricto on 2% potato dextrose agar after 10 days at 20–25°C. Chloroform extracts from P. adametzii culture filtrate and from culture grown on rice often decreased the dry weight of Armillaria colony and diameter of Heterobasidion colony in vitro. The effect depended on species and isolate of Armillaria, Heterobasidion and P. adametzii and concentration of the extract. Higher concentration of chloroform extract increased the dry weight of stems and roots of Pinus sylvestris plants inoculated with either of two isolates of Armillaria ostoyae and one isolate of Armillaria gallica. Lower concentrations of chloroform extract increased the dry weight of stems and roots of P. sylvestris inoculated with another isolate of A. gallica. Culture filtrate of P. adametzii decreased the length of necrosis on P. sylvestris stem inoculated with either of two of four isolates of H. annosum s.s., but if applied 1 month before inoculation, it increased the length of necrosis caused by another H. annosum s.s. isolate. Twenty fractions from the P. adametzii chloroform extract were separated by thin layer chromatography. Carboxylic acids, flavonoids and glycosides were detected in chloroform extract of P. adametzii by high performance liquid chromatography/mass spectrometer analysis. This is the first report of interactions between P. adametzii and either Armillaria or Heterobasidion with P. sylvestris.     

Concentrations of Some Metabolites Produced by Fungi of the Genus Fusarium and Selected Elements in Spring Spelt Grain

The aim of this study was to determine the content of selected elements and metabolites produced by fungi of the genus Fusarium in spelt (Triticum spelta L.) grain and husks and common wheat (T. aestivum L.) grain. Concentrations of trichothecenes, a volatile metabolite trichodiene (TRICH), as well as ergosterol (ERG) and adenosine 5′‐triphosphate (ATP) (a total microbial biomass indicator), were assessed. Toxin concentrations in spelt grain and husks harvested in 2003 and 2004 were comparable. Average deoxynivalenol concentrations reached 450 and 523 μg/kg in grain and 2,162 and 855 μg/kg in husks, respectively. Spelt grain, in comparison with common wheat grain, contained significantly higher concentrations of P, S, Mg, Zn, and Cu and a lower concentration of Al, whereas the concentrations of Ca, Fe, and Pb were significantly higher in the husks than in the grain of this cereal. A comparison of concentrations of Fusarium spp. metabolites in the grain of spelt and common wheat showed that the total concentration of mycotoxins and TRICH was slightly lower in T. spelta, whereas common wheat grain contained lower concentrations of ERG and ATP. The obtained results indicate that spelt husks contain considerable concentrations of trichothecenes.     

Effect of centrally administered opioid receptor agonists on CSF and plasma oxytocin concentrations in dogs

OBJECTIVE: To measure oxytocin concentrations in blood and CSF following central administration of opioid agonists in dogs. ANIMALS: 5 male dogs. PROCEDURE: In a crossover design, CSF and blood were collected immediately before and 15 and 30 minutes after cisternal administration of D-Ala2, MePhe4, Gly-ol-enkephalin (DAMGO, a mu-receptor agonist); D-Pen, pCl-Phe4, D-Pen5-enkephalin (a delta-receptor agonist); U50488H (a kappa-receptor agonist); morphine; and saline (0.9% NaCl) solution. RESULTS: Plasma oxytocin concentration was significantly increased 15 minutes after administration of DAMGO and 30 minutes after administration of U50488H, compared with concentrations obtained after administration of saline solution. Concentration of oxytocin in CSF was significantly decreased 30 minutes after administration of U50488H, compared with concentration after administration of saline solution. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that in male dogs, activation of centrally located mu and kappa receptors elicits an overall excitatory effect on neurons that regulate peripheral release of oxytocin, whereas activation of centrally located kappa receptors elicits an overall inhibitory effect on neurons that regulate central release. These results are in contrast to those reported for other species, in which opioids have a pronounced inhibitory effect on release of oxytocin from the neurohypophysis.     

Use of propofol to manage seizure activity after surgical treatment of portosystemic shunts

The anaesthetic agent propofol has anticonvulsant properties and has been used in the treatment of refractory status epilepticus in human medicine. This report describes the use of propofol in four cats and one dog with naturally occurring seizures following surgical attenuation of single extrahepatic portosystemic shunts. Two of the animals had seizures that were unresponsive to other anticonvulsants. Subanaesthetic doses of intravenous propofol (1.0 to 3.5 mg/kg boluses and 0.01 to 0.25 mg/kg/minute continuous rate infusions) were used to control the seizures in all animals. However, a good neurological outcome was achieved in only two of the five cases, which is similar to the situation in previous reports.     

Natural Occurrence and Distribution of Fusarium Toxins in Contaminated Barley Cultivars

Grain samples of 15 naturally contaminated barley cultivars, collected after harvest in southeastern Poland, were analysed for occurrence of Fusarium trichothecenes and zearalenone (ZEA). Barley kernels were contaminated with the following toxic metabolites: deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-AcDON), 15-acetyldeoxynivalenol (15-AcDON), nivalenol (NIV), HT-2 toxin (HT-2), T-2 toxin (T-2), diacetoxyscirpenol (DAS), T-2 tetraol and ZEA. Significant correlations between concentrations of individual toxins and the dominant Fusarium species were found. Moreover, significant differences in toxin concentrations between cultivars were detected. Distribution of these mycotoxins was studied in two fractions of kernels (diameter > 2.5 mm and < 2.5 mm). A two-factor analysis of variance revealed significant differences between the two fractions, and between the analysed cultivars. Most of the interactions between fractions and cultivars were also significant. The highest concentration of the analysed toxins was in the fraction of small kernels. Kernel fraction <2.5 mm, although accounting for only 12.8% of sample weight, contained high proportions of the total toxin content: 80% of DON, 94% of NIV, 85% of ZEA, 83% of T-2 tetraol, 80% of DAS, 68% of HT-2 toxin and 81% of T-2 toxin. The results indicate that the level of contamination with Fusarium trichothecenes and ZEA, can be reduced by rejection of small kernels.     

The hemodynamic effects of intrathecal oxytocin in normal dogs

OBJECTIVE: To evaluate the hemodynamic effects produced by intrathecal administration of oxytocin in healthy isoflurane-anesthetized dogs. STUDY DESIGN: Prospective single-dose trial. ANIMAL POPULATION: Six healthy purpose-bred adult dogs weighing between 7.3 and 14.5 kg. METHODS: Dogs were anesthetized with isoflurane and instrumented. Oxytocin at a dosage of 1.6 microg/kg was administered intrathecally at the cisternal space at time 0. Hemodynamic data were recorded immediately before and at 1, 5, 15, 30, and 60 minutes after oxytocin administration. Statistical analysis included an analysis of variance (ANOVA) for repeated measures over time. A P < .05 was considered significant. RESULTS: Baseline values +/- standard error of the mean for heart rate, mean arterial pressure, central venous pressure, cardiac output, systemic vascular resistance, mean pulmonary arterial pressure, pulmonary arterial occlusion pressure, and pulmonary vascular resistance were 101 +/- 11 beats/minute, 76 +/- 7 mm Hg, 4 +/- 4 mm Hg, 1.9 +/- 0.7 L/min, 3834 +/- 2556 dynes x sec/cm5, 14 +/- 3 mm Hg, 4 +/- 2 mm Hg, and 430 +/- 201 dynes x sec/cm5, respectively. Variations from the baseline values were seen in all parameters after intrathecal oxytocin administration, but no statistically significant differences were found. CONCLUSION: The intrathecal injection of 1.6 microg/kg of oxytocin is associated with minimal hemodynamic effects during isoflurane anesthesia. CLINICAL RELEVANCE: This study revealed no clinically significant deleterious effects from the intrathecal administration of oxytocin, and investigations into its use as a perioperative analgesic are therefore warranted.