Preliminary Validation and Reliability Testing of the Montreal Instrument for Cat Arthritis Testing, for Use by Veterinarians, in a Colony of Laboratory Cats.

Subtle signs and conflicting physical and radiographic findings make feline osteoarthritis (OA) challenging to diagnose. A physical examination-based assessment was developed, consisting of eight items: Interaction, Exploration, Posture, Gait, Body Condition, Coat and Claws, (joint) Palpation-Findings, and Palpation-Cat Reaction. Content (experts) and face (veterinary students) validity were excellent. Construct validity, internal consistency, and intra- and inter-rater reliability were assessed via a pilot and main study, using laboratory-housed cats with and without OA. Gait distinguished OA status in the pilot ( p = 0.05) study. In the main study, no scale item achieved statistically significant OA detection. Forelimb peak vertical ground reaction force (PVF) correlated inversely with Gait (Rho s = -0.38 ( p = 0.03) to -0.41 ( p = 0.02)). Body Posture correlated with Gait, and inversely with forelimb PVF at two of three time points (Rho s = -0.38 ( p = 0.03) to -0.43 ( p = 0.01)). Palpation (Findings, Cat Reaction) did not distinguish OA from non-OA cats. Palpation-Cat Reaction (Forelimbs) correlated inversely with forelimb PVF at two time points (Rho s = -0.41 ( p = 0.02) to -0.41 ( p = 0.01)), but scores were highly variable, and poorly reliable. Gait and Posture require improved sensitivity, and Palpation should be interpreted cautiously, in diagnosing feline OA.

Association between sensitisation and pain-related behaviours in an experimental canine model of osteoarthritis.

Evaluation of nociceptive sensitisation in canine osteoarthritis studies has been poorly reported, or even related to other clinical symptoms. In 16 dogs, peak vertical force (PVF), subjective pain assessment using 3 scales, sympathetic stress response with electrodermal activity (EDA) measurement, and behavioural changes with video analysis and telemetered motor activity were quantified at baseline (D-7), and 28 and 56 days post transection of the cranial cruciate ligament. As markers of central sensitisation, selected spinal cord biomarkers (substance P and transthyretin) were quantified at D56. Electrical withdrawal thresholds on the stifle and the tail were measured as indicative of peripheral and central quantitative sensory testing (QST) sensitisation, respectively. The effects of vehicle administration (n=8) were compared with tiludronate (2mg/kg subcutaneously, q2 week, starting at D0) administration. Generalized estimated equations tested the association between the behavioural and physiological methods and QST sensitisation, and therefore the sensitivity of the methods for detecting treatment efficacy. Compared to tiludronate, at D56, vehicle-treated dogs had increased spinal substance P (P=0.01), concomitant decreased transthyretin (P=0.02), and (compared to baseline) demonstrated peripheral and central QST sensitisation, which was not present for tiludronate. Only PVF, the spontaneous behaviour "walking with full weight-bearing," and EDA were associated with occurrence of QST sensitisation and indicated significant tiludronate analgesic efficacy after inclusion of central QST sensitisation as a predictor variable in the statistical model. This study establishes the strong interest to implement QST as a predictor of canine osteoarthritis pain symptoms explained by pain sensitisation.

Evoked temporal summation in cats to highlight central sensitization related to osteoarthritis-associated chronic pain: a preliminary study.

In cats, osteoarthritis causes significant chronic pain. Chronicity of pain is associated with changes in the central nervous system related to central sensitization, which have to be quantified. Our objectives were 1) to develop a quantitative sensory testing device in cats for applying repetitive mechanical stimuli that would evoke temporal summation; 2) to determine the sensitivity of this test to osteoarthritis-associated pain, and 3) to examine the possible correlation between the quantitative sensory testing and assessment using other pain evaluation methods. We hypothesized that mechanical sub-threshold repetitive stimuli would evoke temporal summation, and that cats with osteoarthritis would show a faster response. A blinded longitudinal study was performed in 4 non-osteoarthritis cats and 10 cats with naturally occurring osteoarthritis. Quantification of chronic osteoarthritis pain-related disability was performed over a two week period using peak vertical force kinetic measurement, motor activity intensity assessment and von Frey anesthesiometer-induced paw withdrawal threshold testing. The cats afflicted with osteoarthritis demonstrated characteristic findings consistent with osteoarthritis-associated chronic pain. After a 14-day acclimation period, repetitive mechanical sub-threshold stimuli were applied using a purpose-developed device. Four stimulation profiles of predetermined intensity, duration and time interval were applied randomly four times during a four-day period. The stimulation profiles were different (P<0.001): the higher the intensity of the stimulus, the sooner it produced a consistent painful response. The cats afflicted with osteoarthritis responded more rapidly than cats osteoarthritis free (P = 0.019). There was a positive correlation between the von Frey anesthesiometer-induced paw withdrawal threshold and the response to stimulation profiles #2 (2N/0.4 Hz) and #4 (2N/0.4 Hz): Rhos = 0.64 (P = 0.01) and 0.63 (P = 0.02) respectively. This study is the first report of mechanical temporal summation in awake cats. Our results suggest that central sensitization develops in cats with naturally occurring osteoarthritis, providing an opportunity to improve translational research in osteoarthritis-associated chronic pain.

Effect of a diet enriched with green-lipped mussel on pain behavior and functioning in dogs with clinical osteoarthritis.

This study aimed to establish the effect of a diet enriched with green-lipped mussel (GLM) on pain and functional outcomes in osteoarthritic dogs. Twenty-three client-owned dogs with osteoarthritis (OA) were fed a balanced control diet for 30 d and then a GLM-enriched balanced diet for the next 60 d. We assessed peak vertical force (PVF), which is considered to be the gold standard method, at Day (D)0 (start), D30 (end of control diet), and D90 (end of GLM-enriched diet). The owners completed a client-specific outcome measure (CSOM), which is a pain questionnaire, once a week. Motor activity (MA) was continuously recorded in 7 dogs for 12 wk. Concentrations of plasma omega-3 fatty acids were quantified as indicative of diet change. Statistical analyses were linear-mixed models and multinomial logistic regression for repeated measures. The GLM diet (from D30 to D90) resulted in an increase in concentrations of plasma omega-3 fatty acids (P < 0.016) and improvement of PVF (P = 0.003). From D0 to D30, PVF did not significantly change (P = 0.06), which suggests that the GLM diet had a beneficial effect on gait function. Moreover, PVF (P = 0.0004), CSOM (P = 0.006), and MA (P = 0.02) improved significantly from D0 to D90. In general, the balanced control diet could have contributed to reduced OA symptoms, an effect that was subsequently amplified by the GLM diet.

L'objectif de cette étude était d'établir l'effet d'une diète équilibrée enrichie en moule verte (GLM) avec des évaluations fonctionnelles et de douleur sur des chiens arthrosiques. Vingt-trois chiens arthrosiques de propriétaires (région de Montréal, QC) ont été nourris d'abord avec une diète équilibrée contrôle pendant 30 j., puis avec la diète enrichie en GLM pour les 60 j. suivants. Les évaluations incluaient le pic de force verticale (PFV), considéré comme la méthode étalon, au Jour (J)0 (inclusion), J30 (fin de la diète contrôle) et J90 (fin de la diète GLM). Les propriétaires ont complété de manière hebdomadaire une échelle de mesure spécifique à chaque client (CSOM), qui est un questionnaire de quantification de la douleur. L'activité motrice (AM) a été enregistrée en continu sur 7 chiens pour toute la durée de l'étude (12 sem.). Les concentrations plasmatiques d'acides gras oméga-3 ont été quantifiées en tant que marqueurs de changement de diètes. Les analyses statistiques furent des modèles linéaires-mixtes et une régression logistique multinomiale pour mesures répétées. La diète GLM (de J30 à J90) augmenta les concentrations plasmatiques d'acides gras oméga-3 (P < 0,016) ainsi que le PFV (P = 0,003). De J0 à J30, les changements de PFV furent non-significatifs (P = 0,06), ce qui suggère que la diète GLM a eu un effet thérapeutique sur la fonction biomécanique. De plus, PFV (P = 0,0004), CSOM (P = 0,006) et AM (P = 0,02) s'améliorèrent significativement de J0 à J90. De manière globale, il est possible que la diète équilibrée contrôle ait contribué à améliorer les signes d'arthrose, un effet qui fut amplifié par la suite avec la diète GLM.(Traduit par Docteur Eric Troncy).

Validation of orthopedic postoperative pain assessment methods for dogs: a prospective, blinded, randomized, placebo-controlled study.

In the context of translational research, there is growing interest in studying surgical orthopedic pain management approaches that are common to humans and dogs. The validity of postoperative pain assessment methods is uncertain with regards to responsiveness and the potential interference of analgesia. The hypothesis was that video analysis (as a reference), electrodermal activity, and two subjective pain scales (VAS and 4A-VET) would detect different levels of pain intensity in dogs after a standardized trochleoplasty procedure. In this prospective, blinded, randomized study, postoperative pain was assessed in 25 healthy dogs during a 48-hour time frame (T). Pain was managed with placebo (Group 1, n = 10), preemptive and multimodal analgesia (Group 2, n = 5), or preemptive analgesia consisting in oral tramadol (Group 3, n = 10). Changes over time among groups were analyzed using generalized estimating equations. Multivariate regression tested the significance of relationships between pain scales and video analysis. Video analysis identified that one orthopedic behavior, namely 'Walking with full weight bearing' of the operated leg, decreased more in Group 1 at T24 (indicative of pain), whereas three behaviors indicative of sedation decreased in Group 2 at T24 (all p<0.004). Electrodermal activity was higher in Group 1 than in Groups 2 and 3 until T1 (p<0.0003). The VAS was not responsive. 4A-VET showed divergent results as its orthopedic component (4A-VETleg) detected lower pain in Group 2 until T12 (p<0.0009), but its interactive component (4A-VETbeh) was increased in Group 2 from T12 to T48 (p<0.001). Concurrent validity established that 4A-VETleg scores the painful orthopedic condition accurately and that pain assessment through 4A-VETbeh and VAS was severely biased by the sedative side-effect of the analgesics. Finally, the video analysis offered a concise template for assessment in dogs with acute orthopedic pain. However, subjective pain quantification methods and electrodermal activity need further investigation.

Clinical validity of outcome pain measures in naturally occurring canine osteoarthritis.

BACKGROUND: The conceptual validity of kinetic gait analysis and disability outcome assessment methods has guided their use in the assessment of pain caused by osteoarthritis (OA). No consensus on the best clinical methods for pain evaluation in canine OA exists, particularly, when evaluating treatments where a smaller treatment effect is anticipated than with pharmacological pain killers. This study thus aimed at determining the technical validity of some clinical endpoints on OA pain in dogs using the green-lipped mussel (GLM)-enriched diet.Twenty-three adult dogs with clinical OA completed the prospective controlled study. All the dogs were fed a balanced diet over a 30-day control period followed by a GLM-enriched diet over a 60-day period. The kinetic gait analysis parameter (PVF(BW), peak vertical force adjusted for body weight change), electrodermal activity (EDA), and a standardized multifactorial pain questionnaire (MFQ) were performed on day (D) 0 (inclusion), D30 (start) and D90 (end). The owners completed a client-specific outcome measures (CSOM) instrument twice a week. Motor activity (MA) was continuously recorded in seven dogs using telemetered accelerometric counts. We hypothesized that these methods would produce convergent results related to diet changes. A Type I error of 0.05 was adjusted to correct for the multiplicity of the primary clinical endpoints. RESULTS: Neither the EDA nor the MFQ were found reliable or could be validated. Changes in the PVFBW (P(adj) = 0.0004), the CSOM (P(adj) = 0.006) and the MA intensity (P(adj) = 0.02) from D0 to D90 suggested an effect of diet(s). Only the PVFBW clearly increased after the GLM-diet (P(adj) = 0.003). The CSOM exhibited a negative relationship with the PVF(BW) (P = 0.02) and MA duration (P = 0.02). CONCLUSIONS: The PVF(BW) exhibited the best technical validity for the characterization of the beneficial effect of a GLM-enriched diet. The CSOM and MA appeared less responsive following a GLM-diet, but these measures appeared complementary to gait analysis. Apparently, the CSOM provides the capacity to rely on pain OA assessment influenced by both lameness quantification (PVF(BW)) and physical functioning (MA).

Tiludronate treatment improves structural changes and symptoms of osteoarthritis in the canine anterior cruciate ligament model.

INTRODUCTION: The aim of this prospective, randomized, controlled, double-blind study was to evaluate the effects of tiludronate (TLN), a bisphosphonate, on structural, biochemical and molecular changes and function in an experimental dog model of osteoarthritis (OA). METHODS: Baseline values were established the week preceding surgical transection of the right cranial/anterior cruciate ligament, with eight dogs serving as OA placebo controls and eight others receiving four TLN injections (2 mg/kg subcutaneously) at two-week intervals starting the day of surgery for eight weeks. At baseline, Week 4 and Week 8, the functional outcome was evaluated using kinetic gait analysis, telemetered locomotor actimetry and video-automated behaviour capture. Pain impairment was assessed using a composite numerical rating scale (NRS), a visual analog scale, and electrodermal activity (EDA). At necropsy (Week 8), macroscopic and histomorphological analyses of synovium, cartilage and subchondral bone of the femoral condyles and tibial plateaus were assessed. Immunohistochemistry of cartilage (matrix metalloproteinase (MMP)-1, MMP-13, and a disintegrin and metalloproteinase domain with thrombospondin motifs (ADAMTS5)) and subchondral bone (cathepsin K) was performed. Synovial fluid was analyzed for inflammatory (PGE(2) and nitrite/nitrate levels) biomarkers. Statistical analyses (mixed and generalized linear models) were performed with an α-threshold of 0.05. RESULTS: A better functional outcome was observed in TLN dogs than OA placebo controls. Hence, TLN dogs had lower gait disability (P = 0.04 at Week 8) and NRS score (P = 0.03, group effect), and demonstrated behaviours of painless condition with the video-capture (P < 0.04). Dogs treated with TLN demonstrated a trend toward improved actimetry and less pain according to EDA. Macroscopically, both groups had similar level of morphometric lesions, TLN-treated dogs having less joint effusion (P = 0.01), reduced synovial fluid levels of PGE(2) (P = 0.02), nitrites/nitrates (P = 0.01), lower synovitis score (P < 0.01) and a greater subchondral bone surface (P < 0.01). Immunohistochemical staining revealed lower levels in TLN-treated dogs of MMP-13 (P = 0.02), ADAMTS5 (P = 0.02) in cartilage and cathepsin K (P = 0.02) in subchondral bone. CONCLUSION: Tiludronate treatment demonstrated a positive effect on gait disability and joint symptoms. This is likely related to the positive influence of the treatment at improving some OA structural changes and reducing the synthesis of catabolic and inflammatory mediators.

BCR-bound antigen is targeted to exosomes in human follicular lymphoma B-cells.

BACKGROUND INFORMATION: Exosomes are small membrane vesicles secreted by several cell types during exocytic fusion of multivesicular bodies with the plasma membrane. Exosomes from tumour cells can transfer antigens from cell to cell, a property favouring antigen-specific immune responses in vitro and in vivo, and are thus an interesting putative therapeutic tool in human cancers. Exosomes have been well studied in EBV (Epstein-Barr virus)-transformed human B-cell lines; however, biological stimuli regulating exosome secretion quantitatively and/or qualitatively still remain poorly defined. RESULTS: We analysed the effect of the BCR stimulation on exosome release in the human follicular lymphoma B-cell line DOHH2. We found that BCR (B-cell receptor) triggering of DOHH2 cells induced the polarization of CD63(+) MHC class II compartments. Moreover, BCR stimulation increased the release of exosome-associated proteins in the extracellular space. Finally, we found that the BCR was expressed at the surface of exosomes, and could target a bound anti-human IgG to these vesicles. CONCLUSIONS: BCR can modulate the protein content of exosomes upon stimulation, and can target its bound antigen to these vesicles.