Osteopontin in Seminal Plasma and Sperm Membrane of Dogs

The objective of this work was to describe the presence of osteopontin (OPN) in canine seminal plasma and sperm membranes. A pool of seminal plasma and sperm membrane extract from 30 dogs was used. Polyacrylamide electrophoresis gels were performed and the bands were transferred to nitrocellulose paper and Western blot was undertaken using an antibody anti-OPN. Two and 12 bands were marked in the seminal plasma (77.2 and 15.6 kDa) and sperm membrane extracts (70.6–26.6 kDa), respectively. However, from 12 marked bands in the sperm membrane extract, only three (46.4, 37.7 and 36.5 kDa) were strongly marked. We conclude that, seminal plasma and sperm membranes from dogs contain different isoforms of OPN; yet, further studies will be necessary to determine their function in this species.     

Experimental Study of Bone Lengthening in Dogs by Means of Backscattered Scanning Electron Microscopy

Objective— To describe the morphology of calcified tissues involved in distraction osteogenesis (DO) by means of backscattered scanning electron microscopy (BS-SEM).
Study Design— Experimental study.
Animals— Adult female Beagle dogs (n=12).
Methods— Nonsimultaneous and bilateral transverse mid-diaphyseal osteotomies performed in tibiae were stabilized and distracted by a Type Ia external skeletal fixation device. After a latency period of 5 days, distraction was applied at a rate of 0.5 mm every 12 hours for 10 days. Then, the external fixator was maintained in a static mode during the consolidation period until bone healing or euthanasia at 1, 2, 3, 4, 6, 8, 10, 12, 14, and 18 weeks after operations, whichever came first. Distracted regions were isolated and their structure was examined by BS-SEM.
Results— Calcified chondroid tissue was prominent during distraction and calcified cartilaginous tissue during consolidation; both tissues were successively replaced by woven, lamellar, and osteonal bone.
Conclusions— In osteotomized tibia, chondroid tissue is the main component of the mineralization front during distraction, calcified cartilaginous tissue during consolidation, and then both tissues are replaced by woven, lamellar, and osteonal bone. The ossification mechanism of distraction callus is transchondroidal.
Clinical Relevance— BS-SEM is an effective technique for studying progression of bone healing during DO. The presence of chondroid tissue during DO explains why callus mineralization occurs more rapidly during distraction than during static stabilization.     

Arrhythmogenic right ventricular cardiomyopathy associated with severe left ventricular involvement in a cat

An 8-year-old, 4 kg, intact female, domestic shorthaired cat was referred for tachypnea and pleural effusion. A 24-h Holter recording showed numerous polymorphic ventricular premature complexes with left and right bundle branch block morphology. Echocardiographic examination revealed right atrial and ventricular dilation. The right ventricular free wall was thin and aneurysmal. The cat died 10 days after initiation of antiarrhythmic therapy. Gross and histopathological findings were consistent with arrhythmogenic right ventricular cardiomyopathy (ARVC) associated with severe left ventricular involvement.     

Antimicrobial use in the Australian pig industry: results of a national survey

Objective   To describe how various antimicrobials are used in commercial pig herds in Australia and for what disease conditions.
Procedure   Managers of large pig herds (> 200 sows) across Australia and their veterinarians participated in an internet-based survey in 2006. Questions were asked about herd management, the occurrence of bacterial diseases and the type and frequency of antimicrobial use. An antimicrobial usage index for each herd was derived as a summary of the risk of selection for antimicrobial resistance. Relationships between responses were explored with univariate and multivariate analysis.
Results   Responses were received for 197 herds estimated to represent at least 51% of all large pig herds in Australia. Most piggeries relied on drugs of low importance in human medicine (e.g. tetracyclines, penicillins and sulfonamides). For the two drugs of high importance in human medicine that can be legally prescribed to pigs in Australia, ceftiofur use was reported in 25% of herds and virginiamycin in none. Infections attributed to Lawsonia , Mycoplasma and Escherichia coli motivated the most use of antimicrobials. No useful association was found between management factors and the antimicrobial use index.
Conclusion   Most antimicrobial use in the Australian pig industry is based on drugs of low importance to public health. Enhanced control of E. coli infections without reliance on antimicrobials would further reduce the risk of selecting for antimicrobial resistance relevant to public health. The amount of variation in the usage index between herds suggests that antimicrobial use should be constantly reviewed on a herd by herd basis.     

Effects of propofol administration rates on cardiopulmonary function and anaesthetic depth during anaesthetic induction in rats

Objective  To compare the effect of three different administration rates of one dose of propofol on the depth and duration of anaesthesia and cardiopulmonary function during induction of anaesthesia in rats using electroencephalogram (EEG) and clinical signs.
Study design  Prospective, randomized experimental trial.
Animals  Twenty-one, adult, male Sprague-Dawley rats weighing 341 ± 26 g (mean ± SD) (325 to 480 g).
Methods  Animals were randomly divided into three groups to receive 20 mg kg⁻¹ propofol as a bolus injection over 1, 2 or 3 minutes (groups P1, P2 and P3 respectively) intravenously (IV). The total duration and number of burst suppression (BS) episodes in the EEG, the time to loss of righting reflex, reflex score from electrical stimulation, respiratory rate, mean arterial pressure and pulse rate were measured from the beginning of propofol injection.
Results  While loss of reflex to electrical stimulus and time to loss of righting reflex in group P3 were slower than in other groups, the total duration and number of BS episodes in group P3 were significantly higher than in groups P1 and P2 and cardiopulmonary depression was less prominent in group P3 than in groups P1 and P2 up to 2 minutes after the start of administration.
Conclusions  Twenty milligram per kg propofol administration IV for 3 minutes increased the duration of anaesthesia and decreased cardiopulmonary depression in rats.
Clinical relevance  Slower infusion of propofol produced surgical anaesthesia with less cardiopulmonary depression in rats.     

Atipamezole changes the antinociceptive effects of butorphanol after medetomidine–ketamine anaesthesia in rats

Objective  To investigate the effects of atipamezole administered before butorphanol, on tail-flick latency (TFL) and also following medetomidine–ketamine anaesthesia in rats.
Study design  Prospective, randomized experimental study.
Animals  Thirty-four adult male Sprague–Dawley rats weighing 260–390 g.
Methods  TFL in 50 °C water was used to measure antinociception. In the first experiment, rats received saline ( n  = 5) or atipamezole ( n  = 5) followed by butorphanol treatments. In the second experiment, three groups of rats received saline ( n  = 8), atipamezole ( n  = 8) or atimpamezole ( n  = 8) followed by butorphanol 60 minutes after medetomidine–ketamine administration.
Results  In the first experiment, butorphanol significantly increased TFL compared to baseline. Atipamezole significantly decreased this effect. In the second experiment, TFL was significantly increased after recovery from medetomidine–ketamine anaesthesia compared to baseline. This was almost completely blocked by atipamezole. Atipamezole with butorphanol after recovery from the anaesthesia significantly reduced TFL compared to saline but still significantly increased TFL compared to the baseline.
Conclusion and clinical relevance  Atipamezole attenuated the analgesic effects of butorphanol. When postoperative atipamezole is used to hasten recovery from anaesthesia in rats, it may interfere with the postoperative analgesic effect of butorphanol.     

Moxidectin toxicosis in a puppy successfully treated with intravenous lipids

Objective – To describe successful treatment of canine moxidectin toxicosis with the novel therapy of IV lipid administration.
Case Summary – A 16-week-old female Jack Russell Terrier was presented with acute onset of seizures followed by paralysis and coma shortly following suspected exposure to an equine formulation of moxidectin. Moxidectin toxicity was later confirmed. Initial therapy consisted of diazepam, glycopyrrolate, and IV fluids. Mechanical ventilation and supportive nursing care were provided as needed. An emulsion of 20% soybean oil in water, commonly used as the fat component of parenteral nutrition, was administered intravenously as a bolus of 2 mL/kg followed by 4 mL/kg/h for 4 hours beginning 10 hours after exposure and was administered again at a rate of 0.5 mL/kg/min for 30 minutes beginning 25.5 hours post-exposure. Mild improvement was seen after the first dose, and dramatic improvement was noted within 30 minutes of the second dose. The puppy's neurologic status returned to normal within 6 hours of the second administration, with no relapses.
Unique Information Provided – IV lipid therapy is a novel treatment approach for moxidectin toxicity. Its use is supported by recent research and case studies involving IV lipid administration for bupivacaine and other fat-soluble toxins. Lipid administration appeared to reverse the signs of toxicity and may prove to be a highly effective therapy for moxidectin and other fat-soluble toxins.     

Comparison of fluid types for resuscitation after acute blood loss in mallard ducks (Anas platyrhynchos)

Objective – The purpose of this study was to determine the LD₅₀ for acute blood loss in mallard ducks ( Anas platyrhynchos ), compare the mortality rate among 3 fluid resuscitation groups, and determine the time required for a regenerative RBC response.
Design – Prospective study.
Setting – Medical College of Wisconsin Research facility.
Animals – Eighteen mallard ducks were included for the LD₅₀ study and 28 for the fluid resuscitation study.
Interventions – Phlebotomy was performed during both the LD₅₀ and fluid resuscitation studies. Ducks in the fluid resuscitation study received a 5 mL/kg intravenous bolus of crystalloids, hetastarch (HES), or a hemoglobin-based oxygen-carrying solution (HBOCS).
Measurements and Main Results – The LD₅₀ for acute blood loss was 60% of total blood volume. This blood volume was removed in the fluid resuscitation study to create a model of acute blood loss. Following fluid administration, 6 birds in the crystalloid group (66%), 4 birds in the HES group (40%), and 2 birds in the HBOCS group (20%) died. No statistical difference in mortality rate was seen among the 3 fluid resuscitation groups. Relative polychromasia evaluated post-phlebotomy demonstrated regeneration starting at 24 hours and continuing through 48 hours.
Conclusions – The LD₅₀ for acute blood loss in mallard ducks was 60% of their total blood volume. Although no statistical difference in mortality rate was appreciated among the 3 fluid resuscitation groups, a trend of decreased mortality rate was observed in the HBOCS group. An early regenerative response was apparent following acute blood loss.     

Methylparathion- and carbofuran-induced mitochondrial dysfunction and oxidative stress in Helicoverpa armigera (Noctuidae: Lepidoptera)

The cotton bollworm, Helicoverpa armigera is a polyphagous pest of several crops in Asia, Africa, and the Mediterranean Europe. Organophosphate and carbamate insecticides are used on a large-scale to control Helicoverpa. Therefore, we studied the effect of methylparathion and carbofuran, an organophosphate and carbamate insecticide, respectively, on oxidative phosphorylation and oxidative stress in H. armigera larvae to gain an understanding of the different target sites of these insecticides. It was observed that state III and state IV respiration, respiratory control index (RCI), and P/O ratios were inhibited in a dose-dependent manner by methylparathion and carbofuran under in vitro and in vivo conditions. Methylparathion and carbofuran inhibited complex II by ∼45% and 30%, respectively. Lipid peroxidation, H₂O₂ content, and lactate dehydrogenase (LDH) activity increased and glutathione reductase (GR) activity decreased in a time- and dose-dependent manner in insecticide-fed larvae. However, catalase activity was not affected in insecticide-fed larvae. Larval growth decreased by ∼64% and 67% in larvae fed on diets with 100 μM of methylparathion and carbofuran. The results suggested that both the insecticides impede the mitochondrial respiratory functions and induced lipid peroxidation, H₂O₂, and LDH leak, leading to oxidative stress in cells, which contribute to deleterious effects of these insecticides on the growth of H. armigera larvae, along with their neurotoxic effects.