Roles of metalloproteinase-3 and aggrecanase 1 and 2 in aggrecan cleavage during human meniscus degeneration

The meniscus plays important roles in proper knee function. It was recently reported that meniscus degeneration was associated with progression of osteoarthritis (OA). However, little is known about the effects of degradative enzymes on the meniscus matrix, primarily collagen type I and aggrecan, during OA. This study examined the effects of metalloproteinase (MMP) and aggrecanase on the destruction of aggrecan in the human meniscus. Eighteen trimmed meniscus portions were collected during partial menisectomy. Specimens were categorized into 3 groups according to the modified Copenhaver classification based on the degrees of damage to collagen bundles. Histological and immunohistochemical studies were conducted. Sections were stained with antibodies against MMP-3, aggrecanase 1 and 2, and their specific cleavage sites of aggrecan. Their localizations and staining ratios in the inner superficial and outer deep zones of the meniscus were determined separately. The population of chondrocyte-like cells increased with degeneration of the meniscus. MMP-3 and aggrecanase 1 and 2 are primarily expressed and activated in chondrocyte-like cells. MMP-3 expression and activation increased with degeneration and the population of chondrocyte-like cells. Changes in aggrecanase 1 expression with the degeneration were not clearly detected, whereas the expression of aggrecanase 2 was associated with progression of degeneration. MMP-3 and aggrecanases, particularly aggrecanase 2, expressed in chondrocyte-like cells could play important roles in aggrecan degradation in the human meniscus

Influence of lumbar kyphosis and back muscle strength on the symptoms of gastroesophageal reflux disease in middle-aged and elderly people

OBJECTIVE: The objectives of this study was to clarify the relationship between kyphosis and Gastroesophageal reflux disease (GERD) by evaluation of spinal alignment, obesity, osteoporosis, back muscle strength, intake of oral drugs, and smoking and alcohol history in screening of a community population to determine the factors related to GERD symptoms. SUMMARY OF BACKGROUND DATA: GERD increases with age and is estimated to occur in about 30% of people. Risk factors for GERD include aging, male gender, obesity, oral medicines, smoking, and alcohol intake. It has also been suggested that kyphosis may influence the frequency of GERD, but the relationship between kyphosis and GERD is unclear. SUBJECTS AND METHODS: We examined 245 subjects (100 males and 145 females; average age 66.7 years old) in a health checkup that included evaluation of sagittal balance and spinal mobility with SpinalMouse(®), GERD symptoms using the Frequency Scale for Symptoms of GERD (FSSG) questionnaire, body mass index, osteoporosis, back muscle strength, number of oral drugs taken per day, intake of nonsteroidal anti-inflammatory drugs (NSAIDs), intake of bisphosphonates, and smoking and alcohol intake. RESULTS: Multivariate logistic regression analysis including all the variables showed that lumbar lordosis angle, sagittal balance, number of oral drugs taken per day, and back muscle strength had significant effects on the presence of GERD (OR, 1.10, 1.11, 1.09 and 1.03; 95%CI, 1.03–1.17, 1.02–1.20, 1.01–1.18 and 1.01–1.04; p = 0.003, 0.015, 0.031 and 0.038, respectively). The other factors showed no association with GERD. CONCLUSION: This study is the first to show that lumbar kyphosis, poor sagittal balance; increased number of oral drugs taken per day, and decreased back muscle strength are important risk factors for the development of GERD symptoms. Thus, orthopedic surgeons and physicians should pay attention to GERD in elderly patients with spinal deformity

Cervical myeloradiculopathy due to ossification of the posterior longitudinal ligament with versus without diffuse idiopathic spinal hyperostosis

Study Design Retrospective study. Objectives Assess demographics, ossification characteristics, surgical outcomes, and complications in patients with both diffuse idiopathic spinal hyperostosis (DISH) and ossification of the posterior longitudinal ligament (OPLL) compared with patients who only have OPLL. Methods Clinical charts and radiographs of all patients treated surgically from February 2004 to July 2012 for cervical myeloradiculopathy due to DISH with OPLL or OPLL alone were reviewed retrospectively. All patients were observed for a minimum of 1 year. Pre- and postoperative Nurick grades were assessed for all patients. Results Forty-nine patients underwent surgical treatment for cervical myeloradiculopathy due to OPLL, and 8 also had DISH (average 58.9 years, range 37 to 70). The DISH with OPLL group had a significantly higher proportion of subjects with diabetes mellitus (50 versus 9.8% in the OPLL-only group). Everyone in the DISH with OPLL group had continuous or mixed-type OPLL, whereas 78% of patients in the OPLL-only group had primarily segmental type. Operative treatments for patients in the DISH with OPLL group included laminoplasty, anterior decompression and fusion, and posterior laminectomy with fusion. By Nurick grade, 5 patients improved and 3 showed no change. Conclusion Patients with both DISH and OPLL had a higher prevalence of diabetes mellitus and either continuous or mixed-type OPLL classifications. Surgical outcomes were mostly satisfactory; there was no aggravation of symptoms after surgery during the follow up period

Effect of denosumab on Japanese patients with rheumatoid arthritis: a dose-response study of AMG 162 (Denosumab) in patients with RheumatoId arthritis on methotrexate to Validate inhibitory effect on bone Erosion (DRIVE)-a 12-month, multicentre, randomised, double-blind, placebo-controlled, phase II clinical trial

OBJECTIVES: To evaluate efficacy and safety of three different regimens of denosumab, a fully human monoclonal antibody to receptor activator of nuclear factor kappa B (RANK) ligand (RANKL), for Japanese patients with rheumatoid arthritis (RA). METHODS: In this multicentre, randomised, placebo-controlled phase II study, 350 Japanese patients with RA between 6 months and <5 years, stratified by glucocorticoid use and rheumatoid factor status, were randomly assigned to subcutaneous injections of placebo or denosumab 60 mg every 6 months (Q6M), every 3 months (Q3M) or every 2 months (Q2M). All patients basically continued methotrexate treatment and had a supplement of calcium and vitamin D throughout the study. The primary endpoint was change in the modified Sharp erosion score from baseline to 12 months. RESULTS: Denosumab significantly inhibited the progression of bone erosion at 12 months compared with the placebo, and the mean changes of the modified Sharp erosion score at 12 months from baseline were 0.99, 0.27 (compared with placebo, p=0.0082), 0.14 (p=0.0036) and 0.09 (p<0.0001) in the placebo, Q6M, Q3M and Q2M, respectively. Secondary endpoint analysis revealed that denosumab also significantly inhibited the increase of the modified total Sharp score compared with the placebo, with no obvious evidence of an effect on joint space narrowing for denosumab. As shown in previous studies, denosumab increased bone mineral density. No apparent difference was observed in the safety profiles of denosumab and placebo. CONCLUSIONS: Addition of denosumab to methotrexate has potential as a new therapeutic option for patients with RA with risk factors of joint destruction. TRIAL REGISTRATION NUMBER: JapicCTI-101263

Simulation Data Analysis by Virtual Reality System

We introduce new software for analysis of time-varying simulation data and new approach for contribution of simulation to experiment by virtual reality (VR) technology. In the new software, the objects of time-varying field are visualized in VR space and the particle trajectories in the time-varying electromagnetic field are also traced. In the new approach, both simulation results and experimental device data are simultaneously visualized in VR space. These developments enhance the study of the phenomena in plasma physics and fusion plasmas

SURFACE MARKERS AND GENE EXPRESSION TO CHARACTERIZE THE DIFFERENTIATION OF MONOLAYER EXPANDED HUMAN ARTICULAR CHONDROCYTES

Autologous chondrocyte implantation (ACI) is a method of cartilage repair. To improve the quality of regenerated tissue by ACI, it is essential to identify surface marker expression correlated with the differentiation status of monolayer expanded human articular chondrocytes and to define the index for discriminating dedifferentiated cells from monolayer expanded human articular chondrocytes. Normal human articular chondrocytes were cultured in monolayer until passage 4. At each passage, mRNA expression of collagen type I, II, and X and aggrecan was analyzed by real-time quantitative PCR, and the surface marker expression of CD14, CD26, CD44, CD49a, CD49c, CD54, and CD151 was analyzed by fluorescence-activated cell sorting (FACS). The ratios of mRNA levels of collagen type II to I (Col II/Col I) represented the differentiation status of chondrocytes more appropriately during monolayer culture. The surface marker expression of CD44, CD49c, and CD151 was upregulated according to the dedifferentiation status, whereas that of CD14, CD49a, and CD54 was downregulated. The most appropriate combination of the ratio of Col II/Col I was CD54 and CD44. Cell sorting was performed using a magnetic cell sorting system (MACS) according to CD54 and CD44, and real-time quantitative PCR was performed for the cell subpopulations before and after cell sorting. The expression of collagen type II and aggrecan of the chondrocytes after MACS was higher than that before sorting, but not significantly. The mean fluorescence intensity (MFI) ratio of CD54 to CD44 could be an adequate candidate as the index of the differentiation status

Soluble Siglec-9 suppresses arthritis in a collagen-induced arthritis mouse model and inhibits M1 activation of RAW264.7 macrophages

Background: The aim of this study was to assess the effects of soluble sialic acid-binding immunoglobulin-type lectin (sSiglec)-9 on joint inflammation and destruction in a murine collagen-induced arthritis (CIA) model and in monolayer cultures of murine macrophages (RAW264.7 cells and peritoneal macrophages) and fibroblast-like synoviocytes (FLS) derived from patients with rheumatoid arthritis. Methods: DBA/1J mice were immunized with type II collagen. Effects of sSiglec-9 were evaluated using a physiologic arthritis score, histological analysis, serum tumor necrosis factor (TNF)-α concentration, and the proportion of forkhead box P3 (Foxp3)-positive regulatory T (Treg) cells. In vivo biofluorescence imaging was used to assess the distribution of sSiglec-9. Levels of M1 (TNF-α, interleukin [IL]-6, and inducible nitric oxide synthase) and M2 (CD206, Arginase-1, and IL-10) macrophage markers and phosphorylation of intracellular signaling molecules were examined in macrophages, and levels of matrix metalloproteinase (MMP)-1, MMP-3, and MMP-13 were examined in FLS. Results: sSiglec-9 significantly suppressed the clinical and histological incidence and severity of arthritis. The proportion of Foxp3-positive Treg cells significantly improved and serum TNF-α concentration decreased in vivo. Although sSiglec-9 reduced the expression of M1 markers in macrophages, it did not affect the expression of M2 markers and MMPs in FLS. Nuclear factor (NF)-kB p65 phosphorylation was attenuated by sSiglec-9, and chemical blockade of the NF-kB pathway reduced M1 marker expression in RAW264.7 cells. Conclusions: In this study, we have demonstrated the therapeutic effects of sSiglec-9 in a murine CIA model. The mechanism underlying these effects involves the suppression of M1 proinflammatory macrophages by inhibiting the NF-kB pathway. sSiglec-9 may provide a novel therapeutic option for patients with rheumatoid arthritis refractory to currently available drugs