Adverse reactions of α2-adrenoceptor agonists in cats reported in 2003–2013 in Finland

Objective

To describe suspected adverse drug reactions in cats associated with use of α₂-adrenoceptor agonists.

Binding of phenolic compounds and their derivatives to bovine and reindeer beta-lactoglobulin

In plant-based food, phenolic compounds usually do not exist in their native form, but as esters, glycosides, or polymers. The native forms, however, require deglycosylation for their intestinal absorption, and aglycone has been considered to be the potential health-protecting/promoting form. The binding of the aglycones of phenolic compounds to bovine and reindeer beta-lactoglobulins (betaLG) using fluorescence quenching was studied. The effects of pH and storage were also studied. Of the compounds investigated, the majority of flavones, flavonols, flavanones, and isoflavones were bound to betaLG. In the pH studies, no significant effects were found. The fact that the phenolic compounds were not released at pH 2 might indicate that they bind to an external part rather than to the central cavity. Studies implicated that betaLG could act as a binder or carrier for phenolic compounds in acidic, basic, or neutral conditions and that the ligand/betaLG complex can remain stable during storage.     

Cardiovascular and respiratory effects of medetomidine in dogs and influence of anticholinergics

A total of 10 laboratory beagles was used to determine the cardiovascular and respiratory effects of medetomidine. The effects of atropine sulphate and glycopyrrolate on heart rate were also observed. Xylazine was included as a positive control. Medetomidine induced initial hypertension followed by a longer lasting hypotensive period. Evident bradycardia with second degree atrioventricular blocks and decrease in respiratory frequency was observed. Atropine sulphate and glycopyrrolate transiently abolished the bradycardic effect of medetomidine. Xylazine exhibited a similar cardiovascular and respiratory pattern to medetomidine.     

Postoperative pain control in cats: clinical trials with medetomidine and butorphanol

OBJECTIVE: To evaluate the analgesic effects of medetomidine (MED) and butorphanol (BTO) in cats after ovariohysterectomy. STUDY DESIGN: A placebo-controlled, blinded monocenter clinical study. ANIMALS: Healthy adult female client-owned cats. METHODS: Sixty-four cats weighing 3.15 +/- 0.6 kg, presented to the University of Helsinki's Small Animal Teaching Hospital for routine elective ovariohysterectomy, received MED at 15 microg/kg (n = 18), BTO at 0.1 mg/kg (n = 23), or saline (PL) (n = 23) intramuscularly immediately after ovariohysterectomy. Level of pain perception, degree of restlessness, and extent of sedation were scored subjectively before and at 30, 60, 90, and 120 minutes after test-drug administration. RESULTS: BTO provided the best pain relief, followed by MED. Saline provided the least pain relief. Both MED and BTO effectively and identically prevented postoperative restlessness. MED and BTO produced an identical degree of sedation that was better than the PL. CONCLUSIONS: Both MED (at 15 microg/kg) and BTO (at 0.1 mg/kg) prevent postoperative pain in cats after ovariohysterectomy. Clinical Relevance-MED and BTO are useful for preventing postoperative pain in cats.     

24-hour Holter-monitoring in the perianaesthetic period in dogs premedicated with dexmedetomidine

Baseline and perianaesthetic 24-hour Holter recordings were carried out in six healthy beagles. After dexmedetomidine premedication anaesthesia was induced with propofol and maintained with propofol infusion or isoflurane for one hour. Dexmedetomidine alone was used as control. The recordings were analysed for ventricular premature complexes (VPC), atrioventricular (AV) blocks and mean heart rate/hour (HR). In most recordings, no ventricular arrhythmias were detected, the maximum frequency being two VPCs/24 h. VPCs were not seen during anaesthesia or during the recovery period. The development of second-degree AV-blocks varied from dog to dog. Most of the heart blocks were seen during the premedication period when bradycardia was most prominent. During the subsequent night, HR was similar between treatments and did not differ from that seen on the baseline recordings. In beagles treated with dexmedetomidine alone or combined with propofol or propofol/isoflurane, ventricular arrhythmias were not detected more frequently than those reported in healthy non-anaesthetised dogs.     

Investigations on Heterobasidion annosum s.lat. in central and eastern Asia with the aid of mating tests and DNA fingerprinting

To investigate the taxonomy of Heterobasidion in Eurasia, 49 specimens belonging to H. annosum sensu lato from Asia were identified with the aid of mating tests. Most of the specimens originated from north‐eastern and south‐western China and from the Altai region in southern Siberia, but a few isolates from Kirghizia, Japan and India were also tested. In addition to mating tests, the material from China was investigated with DNA fingerprinting. Heterobasidion annosum sensu stricto was identified only from the Altai region. Homokaryotic isolates from other specimens, except the Indian ones, were sexually compatible with H. parviporum, but they also showed a high degree of compatibility with H. abietinum and with the North American S group. The isolates from SW China (eastern Himalayas) mated with about equal frequency with the European strains of H. parviporum and H. abietinum. However, the DNA fingerprinting showed that these isolates were more closely related to H. parviporum, and hence they were tentatively included in this species. The North American S group was more distant from these Eurasian taxa. Four old isolates from India mated only weakly with the members of the H. annosum s.lat. According to the species concept presented, the distribution of H. parviporum extends from western Europe through southern Siberia to northern China, Japan and the eastern Himalayas. H. annosum s.str. is so far identified only from the Altai region outside Europe, and H. abietinum only from Europe.     

Enzymatic modification and particle size reduction of wheat bran improves the mechanical properties and structure of bran-enriched expanded extrudates

The aim of this study was to examine enzymatic modification of wheat bran, performed in a low-moisture process, and the reduction of bran particle size as means of improving the technological performance of wheat bran in expanded extrudates. Modification of bran by hydrolytic enzymes increased the crispiness and decreased the hardness and piece density of extrudates containing wheat bran and endosperm rye flour in 20:80 ratio. These improvements correlated (P < 0.01 or 0.05) with an increased content of water extractable arabinoxylan and decreased water holding capacity of the bran, as well as with increased longitudinal expansion of the extrudates. Furthermore, bran with a fine average particle size (84 μm) produced extrudates with improved mechanical properties and higher radial expansion than coarse bran (particle size 702 μm). The impact of bran particle size was also observed in the cellular structure of the extrudates as differences in cell size and homogeneity. The bran drying method, oven or freeze drying after enzymatic modification, did not have a major impact on the properties of the extrudates. The study showed that the functionality of wheat bran in extrusion can be improved by enzymatic modification using a low-water process and by reduction of bran particle size.     

Clinical effects and pharmacokinetics of medetomidine and its enantiomers in dogs

The clinical effects and pharmacokinetics of medetomidine (MED) and its enanti-omers, dexmedetomidine (DEX) and levomedetomidine (LEVO) were compared in a group of six beagle dogs. The dogs received intravenously (i.v.) a bolus of MED (40 microg/kg), DEX (20 and 10 microg/kg), LEVO (20 and 10 microg/kg), and saline placebo in a blinded, randomized block study in six separate sessions. Sedation and analgesia were scored subjectively, and the dogs were monitored for heart rate, ECG lead II, direct blood pressure, respiratory rate, arterial blood gases, and rectal body temperature. Blood samples for drug analysis were taken. Peak sedative and analgesic effects were observed at mean (+/- SD) plasma levels of 18.5 +/- 4.7 ng/mL for MED40, 14.0 +/- 4.5 ng/mL for DEX20, and 5.5 +/- 1.3 ng/mL for DEX10. The overall level of sedation and cardiorespiratory effects did not differ between MED40, DEX20 and DEX10 during the first hour, apparently due to a ceiling effect. However, the analgesic effect of DEX20 lasted longer than the effect of the corresponding dose of racemic medetomidine, suggesting greater potency for dexmedetomidine in dogs. Levomedetomidine had no effect on cardio-vascular parameters and caused no apparent sedation or analgesia. The pharmacokinetics of dexmedetomidine and racemic medetomidine were similar, but clearance of levomedetomidine was more rapid (4.07 +/- 0.69 L/h/kg for LEVO20 and 3.52 +/- 1.03 for LEVO10) than of the other drugs (1.26 +/- 0.44 L/h/kg for MED40, 1.24 +/- 0.48 for DEX20, and 0.97 +/- 0.33 for DEX10).     

Effects of ovariohysterectomy on canine blood neutrophil respiratory burst: a chemiluminescence study

OBJECTIVE: To examine blood neutrophil counts and luminol-enhanced chemiluminescence (CL) responses in dogs undergoing ovariohysterectomy (OH), premedicated with 2 different drugs. STUDY DESIGN: Randomized clinical study. ANIMALS: Forty-two healthy client-owned bitches. METHODS: Dogs had OH under isoflurane anesthesia with either acepromazine or medetomidine, both in combination with butorphanol, administered as preanesthetic medication. Blood samples were collected when the dog was admitted, at the end of surgery, and the next day (approximately 20 hours after surgery). Blood neutrophils were counted automatically, and neutrophil oxidative activity was assessed by measuring blood CL responses (induced by opsonized zymosan and enhanced by luminol) at 37 degrees C for 40 minutes. RESULTS: Number of circulating neutrophils was significantly increased the day after surgery reflected by enhanced blood CL responses. Neutrophil CL, however, was not significantly altered. No significant differences were detected for perioperative Polymorphonuclear neutrophil (PMN) characteristics between the 2 preanesthetic regimens. CONCLUSIONS: In conclusion, despite clearly increasing the number of circulating neutrophils, OH did not significantly affect neutrophil respiratory burst, as measured by whole-blood CL responses. CLINICAL RELEVANCE: Surgical operation of moderate intensity (e.g., OH) did not significantly alter one of the important immune functions, neutrophil oxidative activity. Further studies are warranted to confirm the significance of this finding, and to assess the value of following this variable in different animal patient populations.     

The impact of medetomidine on the protein‐binding characteristics of MK‐467 in canine plasma

This study determined the unbound fraction of the peripheral α₂‐adrenoceptor antagonist MK‐467 alone and combined with medetomidine. MK‐467 (0.1, 1 and 10 μm ) was incubated in canine plasma with and without medetomidine (molar ratio 20:1), with human serum albumin (HSA) and with α1‐acid glycoprotein (AGP). Rapid equilibrium dialysis was used for the measurement of protein binding. All samples were analysed by liquid chromatography and tandem mass spectrometry to obtain the unbound fraction (f_u) of MK‐467. Unbound fractions (f_u) of MK‐467 in canine plasma (mean ± standard deviation) were 27.6 ± 3.5%, 26.6 ± 0.9% and 42.4 ± 1.2% at 0.1, 1.0 and 10 μm concentrations, respectively. In the presence of medetomidine, f_u were 27.5 ± 0.4%, 26.6 ± 0.9% and 41.0 ± 2.4%. The f_u of MK‐467 in HSA were 50.1 ± 2.5% at 0.1 μm , 49.4 ± 1.2% at 1.0 μm and 56.7 ± 0.5% at 10 μm . f_u of MK‐467 in AGP was 56.3 ± 3.7% at 0.1 μm , 54.6 ± 5.6% at 1.0 μm and 65.3 ± 0.4% at 10 μm . Protein binding of MK‐467 was approximately 70% between 0.1 and 1.0 μm . Medetomidine had no apparent effect on the protein binding of MK‐467.