Hyaluronidase administered with xylazine–tiletamine–zolazepam into adipose tissue shortens recovery from anesthesia in pigs

Objective

To evaluate the effect of hyaluronidase on uptake, duration and speed of elimination of xylazine–tiletamine–zolazepam administered in the subcutaneous fat over the dorsal lumbar region of swine.

Cardiomyocyte calcium cycling in a naturally occurring German shepherd dog model of inherited ventricular arrhythmia and sudden cardiac death

ObjectiveTo further characterize arrhythmic mechanisms in German shepherd dogs (GSDs) affected with inherited ventricular arrhythmias by evaluating intracellular calcium cycling and expression of calcium handling genes.AnimalsTwenty five GSDs, 9 backcross dogs, and 6 normal mongrel dogs (controls) were studied. The GSDs and backcross dogs were from a research colony of inherited ventricular arrhythmias. The control research dogs were purchased.MethodsAction potentials (APs) and pseudo-electrocardiograms (ECG) were recorded from left ventricular (LV) wedge preparations of GSDs and normal dogs. Midmyocardial (Mid) LV cells from GSDs and normal mongrels were isolated by enzymatic digestion. Cells were either field stimulated or voltage clamped and calcium transients were measured by confocal microscopy using the indicator Fluo-3AM. Expression of calcium handling genes was measured by quantitative RT-PCR.ResultsMean calcium transient decay (tau) was not different between affected GSDs and control dogs, but striking cell-to-cell variability for tau was observed within affected GSDs and between affected GSDs and controls (P < 0.0001 each); within-dog variability accounted for 75% of total variability. Calcium sparks and afterdepolarizations occurred in GSD but not control cells. ATP2A2/SERCA2a expression was significantly reduced (P = 0.0063) in affected GSDs and inversely correlated (P = 0.0006) with severity of ventricular arrhythmias.ConclusionsGerman shepherd dogs with inherited ventricular arrhythmias have electrophysiologic abnormalities in calcium cycling associated with reduced ATP2A2/SERCA2a expression. These animals provide a unique opportunity to study calcium remodeling at the genetic and molecular level in familial ventricular arrhythmias.     

Ultrasound‐guided ‘two‐in‐one’ femoral and obturator nerve block in the dog: an anatomical study

ObjectiveTo evaluate the dye extent and distribution at the lumbar plexus (LP) of three volumes of local anaesthetic-methylene-blue solution administered close to the femoral nerve (FN) by the use of a ventral ultrasound (US)-guided suprainguinal approach (SIA).Study designProspective experimental trial.AnimalsTwenty mongrel canine cadavers weighing 17.7 ± 3.8 kg (mean ± SD).MethodsThe left and right LP of two cadavers were dissected to identify the FN, obturator nerve (ON) and lateral femoral cutaneous nerve (LFCN). The extent and distribution of dye at the LP of each of three volumes of injectate of 0.2, 0.4 and 0.6 mL kg^?1 administered close to the FN by a ventral US-guided SIA then were studied in a further 18 dog cadavers (n = 6 per group). Staining of ≥2 cm along the target nerves was indicative of sufficient spread to produce a nerve block.ResultsThe ventral US-guided SIA allowed the observation of the FN within the iliopsoas muscle (IPM) in a total of 17 cadavers. The assessment of the dye extent and distribution revealed a similar pattern regardless of the injected volume. From the injection site, the spreading of injectate occurred in cranial, lateral and caudal directions. The FN and ON were effectively stained in all the cases. The LFCN was not effectively stained in any case.Conclusions and clinical relevanceA volume of 0.2 mL kg^?1 administered close to the FN by a ventral US-guided SIA produced a sufficient distribution of the injectate within the IPM to produce effective staining of the FN and ON. This US-guided technique may be an appropriate alternative to previously reported techniques based on electrolocation to block the FN and ON in the dog.     

Display and selection of chicken IgA Fab fragments

Passive immune therapy is regaining interest to prevent and cure infectious diseases both in human and veterinary medicine. Therefore, systems are required that enable efficient targeted selection of antibodies originating from virtually any animal species. Here, a system for the selection of chicken IgA, using phage display, is described. A novel phagemid vector (pChick3) for the display and selection of chicken IgA antibodies in Fab format was developed. The functionality of pChick3 was demonstrated by construction of an immune antibody library using B cells from chickens infected with Eimeria acervulina. From this library, 10 different IgA fragments with specific binding to the E. acervulina antigen mix, the sporozoite or oocyst fractions were selected. These results demonstrate the efficiency and versatility of the pChick3 vector system that can readily be applied to construct libraries and subsequently select antibodies of the alpha isotype against a wide variety of pathogens and parasites.     

"Time sweet time": circadian characterization of galectin-1 null mice

Background  

Recent evidence suggests a two-way interaction between the immune and circadian systems. Circadian control of immune factors, as well as the effect of immunological variables on circadian rhythms, might be key elements in both physiological and pathological responses to the environment. Among these relevant factors, galectin-1 is a member of a family of evolutionarily-conserved glycan-binding proteins with both extracellular and intracellular effects, playing important roles in immune cell processes and inflammatory responses. Many of these actions have been studied through the use of mice with a null mutation in the galectin-1 (Lgals1) gene. To further analyze the role of endogenous galectin-1 in vivo, we aimed to characterize the circadian behavior of galectin-1 null (Lgals1 ^-/-) mice.