Defining the local nerve blocks for feline distal thoracic limb surgery: a cadaveric study

Though controversial, onychectomy remains a commonly performed distal thoracic limb surgical procedure in cats. Peripheral nerve block techniques have been proposed in cats undergoing onychectomy but evidence of efficacy is lacking. Preliminary tests of the described technique using cadavers resulted in incomplete staining of nerves. The aim of this study was to develop nerve block methods based on cadaveric dissections and test these methods with cadaveric dye injections

Pilot evaluation of a novel unilateral onychectomy model and efficacy of an extended release buprenorphine product

Abstract Background Non-steroidal anti-inflammatory drugs (NSAIDs), transdermal fentanyl patches, and transmucosal buprenorphine are probably the most commonly used options for providing post-operative analgesia in the early at-home period. However, these require daily administration or are associated with abuse concerns. One of the significant unmet needs in veterinary surgery and pain management is for longer acting opioids for cats to effectively bridge the gap between the in-hospital and at-home recovery periods. A proof of concept study of an extended release formulation of buprenorphine HCL (ER-Bup) was conducted using objective kinetic measures and a unilateral onychectomy model. Using a blinded, randomized, two period crossover design, four cats were allocated to control (saline) or ER-Bup (0.6 mg/kg, subcutaneously [SC]) treatment groups. All animals underwent a unilateral forelimb onychectomy per period with a washout/recovery period in between. Observational pain scores and kinetic data (using a pressure sensitive walkway [PSW]) were collected prior to (baseline) and at intervals for 72 h following surgery. Symmetry indices were derived for kinetic variables (peak vertical force [PVF]; vertical impulse [VI]) of each forelimb for landing following a jump and for walking. A rescue analgesic protocol was in place. Effect of surgery and treatment were evaluated using a mixed model statistical approach. Results No cats required rescue analgesics based on subjective pain score. ER-Bup had a positive influence on subjective pain scores during the 72 h postsurgery (p = 0.0473). PVF and VI of the operated limb were significantly decreased for both landing (p < 0.0001 and p < 0.0001) and walking (p < 0.0001 and p < 0.0001 respectively) compared to control. ER-Bup resulted in significantly decreased asymmetry in limb use during landing (PVF, p < 0.0001; VI, p < 0.0001) and walking (PVF, p = 0.0002, VI, p < 0.0001). The novel use of data collected following a jump from an elevated platform appeared to provide all desired information and was easier to collect than walking data. Conclusion This study demonstrates that SC administration of ER-Bup may be an effective analgesic for a 72 h period postoperatively. Furthermore, landing onto a PSW from an elevated perch may be a useful and efficient way to assess analgesics in cats using a unilateral model of limb pain

A Pilot, Open-Label Study to Evaluate the Efficacy of Intra-Articular Administration of a Caninized TNF Receptor Fc Fusion Protein as a Treatment for Osteoarthritis-Associated Joint Pain

Tumor necrosis factor-α (TNF-α) is a potential target for osteoarthritis (OA) treatment. In several recent clinical studies in human OA, anti-TNF-α therapy showed promising results; however, these were open-label and based on patient-reported outcome measures. In this study, we developed a caninized TNF-α receptor-Fc (caTNFR-Fc) fusion protein and conducted a non-randomized, open-label, pilot study in dogs with OA using objectively measured ground reaction forces and activity. The aims of the study were to assess the efficacy of the intra-articular (IA) injection of the caTNFR-Fc fusion protein as a treatment for OA pain, and additionally to evaluate TNF concentrations in synovial fluid (SF) between joints with/without OA in dogs. Dogs (n = 12) with single-limb lameness due to single joint appendicular OA were recruited. All dogs received caTNFR-Fc fusion protein injection into the affected joint under sedation. Objective kinetic gait analysis using force plate was performed prior to (baseline), and at 14- and 28-days following treatment. Additionally, SF samples were collected from OA joints (n = 69) and non-OA joints (n = 79) in a different cohort of dogs and TNF-α were measured using enzyme-linked immunosorbent assay. No significant treatment effects on the limb use, activity, and the questionnaire were found. The concentration of TNF-α was significantly higher in OA joints than in healthy joints (p = 0.0019), but TNF-α was detected in only 10/69 OA samples. The IA injection of caTNFR-Fc fusion protein provided no benefit in terms of objective limb use and activity data in dogs with OA in this pilot study. Although the SF concentration of TNF-α was significantly higher in OA joints, few OA joints had measurable TNF-α. Collectively, the data indicate TNF-α may not be a good therapeutic target in canine OA

Initial exploration of the discriminatory ability of the PetPace collar to detect differences in activity and physiological variables between healthy and osteoarthritic dogs

Background Accelerometry has been used to evaluate activity in dogs with osteoarthritis (OA) pain, especially in relation to effect of treatment; however no studies have compared accelerometry-measured activity in dogs with OA-pain and healthy dogs. The aims of this study were to (1) compare activity output from the PetPace collar with the validated Actical monitor and (2) determine if PetPace collar outputs (overall activity, activity levels, body position, and vital signs) differed between healthy dogs and dogs with OA-pain. Methods This was an observational, non-interventional study in healthy dogs and dogs with OA-pain. All dogs were outfitted with the PetPace collar and the Actical monitor simultaneously for 14 days. Output from these devices was compared (correlations), and output from the PetPace device was used to explore differences between groups across the activity and vital sign outputs (including calculated heart rate variability indices). Results There was moderate correlation between the PetPace collar and Actical monitor output (R2 = 0.56, p < 0.001). Using data generated by the PetPace collar, OA-pain dogs had lower overall activity counts and spent less time standing than healthy dogs. Healthy dogs spent more time at higher activity levels than OA-pain dogs. Certain heart rate variability indices in OA-pain dogs were lower than in healthy dogs. Conclusions and clinical relevance The results of this study suggest that the PetPace collar can detect differences between healthy dogs and those with OA-pain, and that OA-pain negatively impacts overall activity levels in dogs, and especially higher intensity activity

Biological resurfacing in a canine model of hip osteoarthritis

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Modelos de predicción de mortalidad en cirugía cardiaca: diseño de un modelo, evaluación de modelos generales y análisis de mortalidad ajustada a riesgo

Las intervenciones de cirugía cardiaca tienen costes elevados, emplean recursos complejos, y se asocian a riesgos quirúrgicos medios comparativamente más elevados que la mayor parte de las demás disciplinas quirúrgicas. Es un área de especial interés para los estudios de evaluación de riesgo y de análisis de calidad. El parámetro más empleado como variable de medición es la mortalidad hospitalaria, por su relevancia clínica, facilidad de medir, y estandarización. La necesidad de establecer rangos de mortalidad aceptable ha originado iniciativas nacionales para medirlo. Ningún organismo emite datos de mortalidad por tipo de procedimiento ajustado a riesgo de los servicios cardioquirúrgicos adaptados a criterios acordados con las sociedades científicas. Las fuentes existentes son las memorias de resultados de las Consejerías, los registros de gastos y el Registro de Actividad de la SECTCV. Ninguna de estas fuentes contiene información paciente a paciente, ni información pronóstica de los pacientes. La fuente más útil a nivel clínico es el Registro de Intervenciones de la SECTCV. El análisis de la mortalidad debe tener en cuenta el riesgo de los pacientes. Los modelos de predicción de mortalidad estiman este riesgo..

Electrophysiological characterisation of central sensitisation in canine spontaneous osteoarthritis

In man, central sensitisation (CS) contributes to the pain of osteoarthritis (OA). Dogs with spontaneous OA may also exhibit CS. Electrophysiological reflex measurements are more objective than behavioural assessments, and can be used to evaluate CS in preclinical and clinical studies. It was hypothesised that dogs suffering from OA would exhibit electrophysiological characteristics indicative of CS, associated with reduced diffuse noxious inhibitory controls (DNIC). 117 client owned dogs were recruited to the study. Hindlimb nociceptive withdrawal reflex (NWR) thresholds, stimulus response, and temporal summation characteristics were recorded, during alfaxalone anaesthesia, from 46 OA dogs, 29 OA dogs receiving non-steroidal anti-inflammatory drugs (OANSAID), and 27 breed- and weight-matched control dogs. Efficacy of DNIC was evaluated in 12 control and 11 of the OA dogs, by application of a mechanical conditioning stimulus to the contralateral forelimb. NWR thresholds were higher in OA compared with control dogs (p = 0.02). Stimulus response characteristics demonstrated an augmented response in OANSAID dogs compared with OA (p < 0.001) and control (p < 0.001) dogs. Temporal summation demonstrated exaggerated C-fibre mediated responses in both OA (p < 0.001) and OANSAID (p = 0.005) groups, compared with control animals. Conditioning stimulus application resulted in inhibition of test reflex responses in both OA and control animals (p < 0.001); control animals demonstrated greater inhibition compared with OA (p = 0.0499). These data provide evidence of neurophysiological changes consistent with CS in dogs with spontaneous OA, and demonstrate that canine OA is associated with reduced DNIC

Hepatitis C Virus Infection Suppresses the Interferon Response in the Liver of the Human Hepatocyte Chimeric Mouse

BACKGROUND AND AIMS: Recent studies indicate that hepatitis C virus (HCV) can modulate the expression of various genes including those involved in interferon signaling, and up-regulation of interferon-stimulated genes by HCV was reported to be strongly associated with treatment outcome. To expand our understanding of the molecular mechanism underlying treatment resistance, we analyzed the direct effects of interferon and/or HCV infection under immunodeficient conditions using cDNA microarray analysis of human hepatocyte chimeric mice. METHODS: Human serum containing HCV genotype 1b was injected into human hepatocyte chimeric mice. IFN-α was administered 8 weeks after inoculation, and 6 hours later human hepatocytes in the mouse livers were collected for microarray analysis. RESULTS: HCV infection induced a more than 3-fold change in the expression of 181 genes, especially genes related to Organismal Injury and Abnormalities, such as fibrosis or injury of the liver (P = 5.90E-16∼3.66E-03). IFN administration induced more than 3-fold up-regulation in the expression of 152 genes. Marked induction was observed in the anti-fibrotic chemokines such as CXCL9, suggesting that IFN treatment might lead not only to HCV eradication but also prevention and repair of liver fibrosis. HCV infection appeared to suppress interferon signaling via significant reduction in interferon-induced gene expression in several genes of the IFN signaling pathway, including Mx1, STAT1, and several members of the CXCL and IFI families (P = 6.0E-12). Genes associated with Antimicrobial Response and Inflammatory Response were also significantly repressed (P = 5.22×10(-10)∼1.95×10(-2)). CONCLUSIONS: These results provide molecular insights into possible mechanisms used by HCV to evade innate immune responses, as well as novel therapeutic targets and a potential new indication for interferon therapy

Cationic surfactants induce apoptosis in normal and cancer cells

Cationic surfactants, such as benzalkonium chloride and benzethonium chloride, possess quaternary ammonium salt. These surfactants have antimicrobial action and are used as a preservative and an antiseptic. The positively charged polar head of cationic surfactants seems to play a role in the antimicrobial action of these compounds. Recently, benzalkonium chloride in eye drops has been reported to induce apoptosis in conjunctival cells. Here, we examined whether various types of surfactants including anionic and amphoteric surfactants induce apoptosis or not in mammalian cells. Antimicrobial cationic surfactants induced apoptosis at lower concentration than its critical micelle concentration (CMC) in rat thymocytes. Other quaternary ammonium surfactants, such as cetyltrimethylammonium bromide, similarly increased biochemical and morphological features of apoptosis, whereas both anionic and amphoteric surfactants had no significant effect on these apoptotic features. These results suggest that the positive charge of quaternary ammonium surfactants is involved with onset of the apoptotic process. The treatment of benzethonium chloride also led to apoptotic cell death in Jurkat cells. These results indicate that cationic surfactants induce apoptosis in the normal and cancer cellsNRC publication: Ye