Variations in gene expression levels with severity of synovitis in dogs with naturally occurring stifle osteoarthritis.

Osteoarthritis (OA) is one of the major causes of chronic pain in dogs. However, the pathogenesis of OA has not been fully understood in dogs. The objective of this study was to comprehensively investigate the mRNA expression levels of proinflammatory cytokines, inflammatory mediators, nerve growth factor and its receptor, and matrix metalloproteinases in the synovium of dogs with spontaneous OA as well as to elucidate their relationships with the severity of synovitis. Dogs that were diagnosed with stifle OA on the basis of radiographic findings were included, and the degree of synovitis was observed using stifle arthroscopy. The dogs were assigned to two different groups depending on their synovitis scores: the low-grade group (score of 1 or 2; n = 8) and high-grade group (score of 3 to 5; n = 18). The dogs showing no evidence of orthopedic disease were included in the control group (n = 6). Synovial tissue samples were collected from the sites at which synovitis scores were assessed using arthroscopy. Total RNA was extracted from the collected synovial tissue, and cDNA was synthesized. Subsequently, RT-qPCR were performed using canine-specific primer sets for IL1B, IL6, CXCL8, TNF, TGFB1, PTGS2, PTGES, MMP3, MMP13, NGF, NTRK1, and PTGER4. Expression levels of IL1B, IL6, CXCL8, and MMP13 were significantly higher in the high-grade group than in the control group. In addition, expression levels of IL1B, CXCL8, TNF, and PTGS2 were significantly higher in the high-grade group than in the low-grade group. Expression levels of IL1B, IL6, CXCL8, TNF, PTGS2, and PTGER4 showed significant positive correlation with synovitis score. In conclusion, all mRNA expression levels in the synovial membrane varied according to the degree of synovitis in dogs with spontaneous OA. Thus, this study may partially elucidate the pathogenesis of synovitis in dogs with spontaneous OA

Epidemiologic study of dogs with the displacement or deformity of the medial and lateral fabellae in Japan

The prevalences of displacement and deformity of the medial and lateral fabellae in dogs were investigated. This was a retrospective epidemiologic study.　Radiographs of canine stifle joints (1022 limbs, 534 dogs) were obtained. The images were taken at the Nihon University Animal Medical Center and three private animal hospitals from January 2003 to July 2012. The position and morphology of the medial or lateral fabella were evaluated on the radiographs. The prevalence of displacement of the medial and lateral fabellae was 1.7% and 0.3%, respectively. The prevalence of deformity of the medial and lateral fabellae was 6.9% and 4.6%, respectively. Aplasia or hypoplasia of the fabella was detected more frequently in the medial fabella. On the other hand, a bipartite or multipartite fabella was observed more frequently in the lateral fabella. Nearly all cases of displacement or deformity of the fabella occurred in dogs weighing less than 10 kg. Abnormalities of the fabella were observed in the medial and lateral fabella. We found that abnormal fabellae were closely associated with medial patellar luxation and to a lesser extent with cranial cruciate ligament rupture. No clinical signs were associated with an abnormality of the fabella, with the exception of two dogs with traumatic avulsion of the lateral head of the gastrocnemius muscle

Liquid Cooling System for CPU by Electroconjugate Fluid

The dissipated power of CPU for personal computer has been increased because the performance of personal computer becomes higher. Therefore, a liquid cooling system has been employed in some personal computers in order to improve their cooling performance. Electroconjugate fluid (ECF) is one of the functional fluids. ECF has a remarkable property that a strong jet flow is generated between electrodes when a high voltage is applied to ECF through the electrodes. By using this strong jet flow, an ECF-pump with simple structure, no sliding portion, no noise, and no vibration seems to be able to be developed. And then, by the use of the ECF-pump, a new liquid cooling system by ECF seems to be realized. In this study, to realize this system, an ECF-pump is proposed and fabricated to investigate the basic characteristics of the ECF-pump experimentally. Next, by utilizing the ECF-pump, a model of a liquid cooling system by ECF is manufactured and some experiments are carried out to investigate the performance of this system. As a result, by using this system, the temperature of heat source of 50 W is kept at 60°C or less. In general, CPU is usually used at this temperature or less