Cover Image,Volume 15, Issue 3

The cover image, by M. E. Gray et al., is based on the Original Article Dual targeting of EGFR and ERBB2 pathways produces a synergistic effect on cancer cell proliferation and migration in vitro, DOI: 10.1111/vco.12230 .

     

Real-time 3D transesophageal echocardiography-guided closure of a complicated patent ductus arteriosus in a dog

Advanced imaging modalities are becoming more widely available in veterinary cardiology, including the use of transesophageal echocardiography (TEE) during occlusion of patent ductus arteriosus (PDA) in dogs. The dog in this report had a complex history of attempted ligation and a large PDA that initially precluded device placement thereby limiting the options for PDA closure. Following a second thoracotomy and partial ligation, the morphology of the PDA was altered and device occlusion was an option. Angiographic assessment of the PDA was limited by the presence of hemoclips, and the direction of ductal flow related to the change in anatomy following ligature placement. Intra-operative TEE, in particular real-time three-dimensional imaging, was pivotal for assessing the PDA morphology, monitoring during the procedure, selecting the device size, and confirming device placement. The TEE images increased operator confidence that the size and location of the device were appropriate before release despite the unusual position. This report highlights the benefit of intra-operative TEE, in particular real-time three-dimensional imaging, for successful PDA occlusion in a complicated case.     

Isoflurane minimum alveolar concentration sparing effects of fentanyl in the dog

Objective

To characterize the isoflurane-sparing effects of a high and a low dose of fentanyl in dogs, and its effects on mean arterial pressure (MAP) and heart rate (HR).

Colostral immunoglobulin concentrations in Holstein and Guernsey cows.

OBJECTIVE: To compare the concentration of IgG in colostrum between Holstein and Guernsey cows and among cows of various lactations. DESIGN: Cross-sectional cohort study. SAMPLE POPULATION: Colostrum samples from 77 Holstein and 24 Guernsey cows. PROCEDURE: Colostrum samples were obtained from 101 cows. Colostral IgG concentration was determined, using a radial immunodiffusion assay. Regression analysis was used to determine the effect of breed and lactation number on colostral IgG concentration. Survival analysis and t-tests were used to compare the proportion of colostrum samples that would provide 100 g of IgG for various volumes of colostral intake. RESULTS: Guernsey cows produced 36.4 g of IgG/L of colostrum more than that of Holstein cows. Cows in the third or greater lactation produced 19.5 g of IgG/L of colostrum more than that of first-lactation cows. The IgG concentration of colostrum produced by second-lactation cows did not differ significantly from that produced by first-lactation cows. The colostral IgG concentration of these Holstein and Guernsey cows was higher than values that have been reported elsewhere. CONCLUSIONS AND CLINICAL RELEVANCE: Volume of colostrum needed to meet IgG intake goals is probably lower for Guernsey cows than Holstein cows. Colostrum from first-lactation cows was adequate in IgG content. The practice of discarding colostrum from first-lactation cows on the basis of inadequate IgG content was not justified in this study.     

Evaluation of iodophor skin preparation techniques and factors influencing drainage from ventral midline incisions in horses.

OBJECTIVE: To document natural bacterial flora on the ventral aspect of the equine abdomen, to compare 2 preparation techniques, and to identify potential risk factors that may contribute to incisional drainage. DESIGN: Prospective study. ANIMALS: 53 horses undergoing exploratory celiotomy. PROCEDURE: Group-1 horses (n = 26) were prepared with povidone-iodine and alcohol. Group-2 horses (27) were prepared with a film-forming iodophor complex. Numbers of bacterial colony-forming units (CFU) were measured before and after surgical scrub, following skin closure, and after recovery from general anesthesia. Swab specimens to identify normal skin bacterial flora and potential pathogens were obtained by swabbing a 4 x 4-cm area. Variables that might affect incisional drainage were also investigated. RESULTS: For both techniques, there was a significant reduction in bacterial numbers after skin preparation. Incisional drainage was observed in 14 (26%) horses (8 group-1 and 6 group-2 horses). Preexisting dermatitis, poor intraoperative drape adherence, high number of bacterial CFU obtained after recovery from anesthesia, and high number of CFU obtained from the surgery room environment were the main risk factors associated with subsequent incisional drainage. Bacillus spp, nonhemolytic Staphylococcus spp, Micrococcus spp, Corynebacterium spp, Streptomyces spp, other nonenteric genera, and nonhemolytic Streptococcus spp were the most common isolates obtained before surgical scrub. CONCLUSIONS AND CLINICAL RELEVANCE: Both skin preparation techniques were equally effective in reducing numbers of bacterial CFU by 99%, and a significant difference was not found in incisional drainage rate between groups. Protection of the wound during recovery from anesthesia and the immediate postoperative period may reduce incisional drainage after abdominal surgery in horses.     

Evaluation of slice shear force as an objective method of assessing beef longissimus tenderness.

Experiments were conducted to develop an optimal protocol for measurement of slice shear force (SSF) and to evaluate SSF as an objective method of assessing beef longissimus tenderness. Whereas six cylindrical, 1.27-cm-diameter cores are typically removed from each steak for Warner-Bratzler shear force (WBSF) determination, a single 1-cm-thick, 5-cm-long slice is removed from the lateral end of each longissimus steak for SSF. For either technique, samples are removed parallel to the muscle fiber orientation and sheared across the fibers. Whereas WBSF uses a V-shaped blade, SSF uses a flat blade with the same thickness (1.016 mm) and degree of bevel (half-round) on the shearing edge. In Exp. 1, longissimus steaks were acquired from 60 beef carcasses to determine the effects of belt grill cooking rate (very rapid vs. rapid) and conditions of SSF measurement (hot vs cold) on the relationship of SSF with trained sensory panel (TSP) tenderness rating. Slice shear force was more strongly correlated with TSP tenderness rating when SSF measurement was conducted immediately after cooking (r = -.74 to -.76) than when steaks were chilled (24 h, 4 degrees C) before SSF measurement (r = -.57 to -.72). When SSF measurement was conducted immediately after cooking, the relationship of SSF with TSP tenderness rating did not differ among the belt grill cooking protocols used to cook the SSF steak. In Exp. 2, longissimus steaks were acquired from 479 beef carcasses to compare the ability of SSF and WBSF of 1.27-cm-diameter cores to predict TSP tenderness ratings. Slice shear force was more strongly correlated with sensory panel tenderness rating than was WBSF (r = -.82 vs -.77). In Exp. 3, longissimus steaks were acquired from 110 beef carcasses to evaluate the repeatability (.91) of SSF over a broad range of tenderness. Slice shear force is a more rapid, more accurate, and technically less difficult technique than WBSF. Use of the SSF technique could facilitate the collection of more accurate data and should allow the detection of treatment differences with reduced numbers of observations and reduced time requirements, thereby reducing research costs.     

Cerebral larva migrans in a raccoon (Procyon lotor)

During 1997, gross and histopathologic examinations were performed on an adult female raccoon (Procyon lotor) that was live-trapped in Corvallis, Oregon. Multifocal eosinophilic granulomas indicative of neural and visceral larva migrans were observed. However, within these granulomas, the presence of parasitic larva was seen only in the cerebrum. Morphologic characteristics indicated that the nematode was an ascarid larva. However, it was smaller than the larva of Baylisascaris sp. This appears to be the first documented case of cerebral larva migrans in a raccoon.     

Effect of inhaled nitric oxide on experimentally induced pulmonary hypertension in neonatal foals

OBJECTIVE: To evaluate the efficacy of inhaled nitric oxide (NO) in anesthetized healthy newborn foals with experimentally induced pulmonary hypertension. ANIMALS: Five 1- to 3-day-old foals. PROCEDURE: Anesthesia was induced and maintained with propofol, and foals were intubated and mechanically ventilated. Systemic pressure and pulmonary arterial pressure (P(PA)) were recorded every 30 seconds. Hypertension was induced via a hypoxic gas mixture or chemical vasoconstriction, using the thromboxane mimetic U46619. Nitric oxide was added at a concentration of 80 parts per million (ppm) for 6 minutes under baseline conditions and during pulmonary hypertension-induced alveolar hypoxia (inspired oxygen concentration = 0.08). Nitric oxide (20, 40, 80, and 160 ppm) was evaluated during U46619-induced hypertension. Samples for determination of arterial blood gas tensions were collected before and after each NO treatment. RESULTS: Inhaled NO (approx 80 ppm) did not have an effect on baseline variables. Infusion of U46619 (0.35 +/- 0.04 microg/kg of body weight/min) or alveolar hypoxia resulted in increased P(PA) and decreased arterial oxygenation (PaO2) and hemoglobin saturation (HbSat). The increase in P(PA) was attenuated, in a dose-dependent manner, by NO during U46619 infusion and reversed by NO during induced hypoxemia. The PaO2 and HbSat were significantly improved at all NO doses during U44619 infusion but not during alveolar hypoxia. For all inhaled NO concentrations, nitrogen dioxide and methoglobin values were < 5 ppm and 3%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Nitric oxide is a potent, selective vasodilator of the pulmonary circulation in healthy newborn foals. Inhaled NO may have value as a therapeutic agent in foals with pulmonary hypertension.     

Immunohistochemical detection of canine distemper virus in haired skin, nasal mucosa, and footpad epithelium: a method for antemortem diagnosis of infection.

A reliable antemortem diagnostic method is needed for determining infection with canine distemper virus (CDV). The utility of immunohistochemical detection of CDV antigen was examined was examined for samples of nasal and footpad epithelium and haired skin in dogs with and without detectable CDV antigen in the lung and/or brain. Tissues from 57 dogs at risk of CDV infection were tested. Viral antigen was found in the lung and/or brain of 28 dogs. Among these dogs, viral antigen was demonstrated in the epithelial cells of the nasal mucosa in 24 of 27 dogs, in the footpad epithelium in 24 of 26 dogs, and in the haired skin of the dorsal neck in 26 of 27 dogs. Among the 29 dogs without CDV antigen in either the lung or brain, 1 dog had positive staining for viral antigen in the skin and nasal mucosa. Biopsies of haired skin of the dorsal neck, which is relatively simple to sample, can be used for immunohistochemical testing for acute and subacute infection with CDV.     

Matrix metalloproteinase-2 and -9 are activated in joint diseases.

A study was performed to identify the activation status of the gelatinase MMPs, MMP-2 and -9, in both normal and diseased equine articular tissues. In addition, the production and activation status of equine MMP-2 and -9 by equine articular cells and tissues in response to increasing IL-1beta concentrations was assessed. The study was performed to test the hypothesis that activation of MMPs is a fundamental step in the pathogenesis of joint diseases; and that this activation is mediated by the cytokine IL-1. Using purified equine MMP-2 and -9, the molecular weights of the zymogen and activated form of equine MMP-2 and -9 were identified by a combination of gelatin zymography and a gelatin degradation assay using aminophenylmercuric acetate as a chemical activator of the molecules. Normal equine articular tissues (cartilage and synovial membrane) maintained in short-term tissue culture produced MMP-2 zymogen alone, while similar tissues obtained from a variety of pathological conditions produce both zymogen and active MMP-2, as well as MMP-9 monomer and dimer. Activated MMP-9 was an inconsistent finding. Normal equine synovial fibroblasts in monolayer culture produced zymogen MMP-2 alone under basal conditions. A mild increase in active and zymogen MMP-2 levels occurred with IL-1beta treatment. Equine synovial membrane explants demonstrated a dose-dependent increase in active and zymogen MMP-2 and MMP-9 levels following IL-1beta treatment. Monolayer chondrocyte cell cultures demonstrated a dose-dependent mild increase in active and zymogen MMP-2 following IL-1beta treatment. Explant cartilage cultures demonstrated a dose-dependent mild increase in zymogen MMP-2 alone following IL-1beta treatment. This study supports the hypothesis that activation of MMPs is occurring in joint disease, and that in vitro stimulation of equine articular cells and tissues causes not only an increase in MMP production, but also an increase in amount of activated enzyme released. Further research is required to investigate the role of MMP activation in joint diseases, and to investigate the potential use of therapeutic agents, which inhibit MMP activation, in the treatment and prevention of joint diseases.