Experimental design of 4-point supported belt robot for sanding large convex surfaces

In general, sanding robots that move as if drawing a line along a surface are mainly used when sanding objects with a large area; however, they require a long working time, and it is difficult to secure a uniform sanded area. This study focuses on large-area sanding robots, such as those for ships, storage tanks, and tank lorries, and proposes an adaptive belt tension robot equipped with a 4-point supported belt mechanism capable of sanding variable curved surfaces. In addition, a sanding normal force prediction formula is proposed to describe the sanding performance of the contact surface. This equation consists of the concentrated load function due to the belt movement and the normal force due to the vertical and horizontal elongation of the belt. A video image analysis was performed to calculate the sanding area. Therefore, we determined whether the area was uniformly sanded. The dimensions of the test bench (W × D × H) were 1700 mm × 1450 mm × 900 mm. Experiments were performed using the proposed techniques on convex specimens with radii of 725, 1000, and 2100 mm. The sanding performance was improved by 43 % compared with that of a general belt-sanding robot.

The stiffness adjustable wheel mechanism based on compliant spoke deformation

This study proposes a variable-stiffness mechanism for non-pneumatic tires such that can actively adapt to various environments. Non-pneumatic tire is a compliant wheel structure that offers superior robustness and adaptability compared to pneumatic tires. However, the tire designed for certain terrain exhibits relatively high rolling resistance and inadequate suspension. To address these problems, a stiffness-adjustable wheel (SAW) that can modify the force applied to the contact surface is introduced in this study. In addition, the shape of SAW is optimized to maintain a desirable range of stiffness under different conditions. The optimization is conducted with experimental method, because nonlinear response of material and interference between components make it difficult to predict the characteristic of the wheel at large deformation. The SAW has potential for application in various mobile platforms to provide adequate stiffness for a variety of terrains and driving conditions.

2 DOF transformable wheel design based on geared 8 bar parallel linkage mechanism

This paper introduces a novel design and static optimization for a two-degrees-of-freedom transformable wheel based on a geared linkage mechanism. Overcoming obstacles, including stairs, with small wheels is a major challenge in the field of mobile robotics research. Among various robots, the transformable wheel, which can change the shape of the wheel to overcome steps and optimize the path, was presented and has undergone many improvements. Nevertheless, problems such as asymmetry and structural strength remain. Therefore, the design of this paper aims to address the structural inefficiencies identified in the previous research model, which were attributed to the asymmetric placement of the linear motion guide. Through the implementation of this mechanism, the linear motion of the lobe can be segregated, enabling each input motor to share the workload effectively. The optimization process focus on determining the optimal linkage length under static conditions, resulting in improved structural characteristics and force distribution of linkage within the designated workspace. As a result, asymmetry of motion is eliminated, required intervention angle of the driving motor and stress of linkage was reduced by 36.24% and 8.35%, respectively.

Empirical optimization of an angled spoke paddling wheel with self-rotating mechanism

The development of the maritime industry has led to a corresponding increase in maritime accidents. Maritime accidents are major events that are costly to recover and can cause casualties. Moreover, individuals who are brought to the scene for recovery or rescue are at risk. To tackle this issue, the wheel mechanism of a water rescue robot, i.e., the angled spoke paddling wheel (ASPW), has been studied. The purpose of this study is to optimize the paddle design parameters of the ASPW using the Taguchi method. Experiments are conducted by creating paddles with various combinations of design parameters using $${\textbf{L}}_9$$ L 9 ($$3^4$$ 3 4 ) orthogonal arrays. The objective function is determining the optimal combination of paddle design parameters that will produce the greatest thrust force at the same RPM. Sensitivity analysis of each design parameter is conducted by calculating the signal-to-noise ratio from the experimental results. The pitch angle is found to be the most sensitive parameter. An additional experiment is conducted based on the results of the sensitivity analysis. The results show that the optimal design parameters are a pitch angle of $$0^{\circ }$$ 0 ∘ , rectangular end shape, X-axis curvature of 37.5 mm, and Y-axis curvature of 25 mm. The paddle with this combination of design parameters have a maximum thrust force of 64.74 gf at 120 RPM and exhibit up to an 18.27% improvement in performance compared with the initial paddle before optimization.

Detection method for transparent window cleaning device, image processing approach

Recent years, there has been an increase in the number of high-rise buildings, and subsequently, the interest in external wall cleaning methods has similarly increased. While a number of exterior wall cleaning robots are being developed, a method to detect contaminants on the exterior walls is still required. The exteriors of most high-rise buildings today take the form of a window curtain-wall made of translucent glass. Detecting dust on translucent glass is a significant challenge. Here, we have attempted to overcome this challenge using image processing, inspired by the fact that people typically use just the ‘naked eye’ to recognize dust on windows. In this paper, we propose a method that detects dust through simple image processing techniques and estimates its density. This method only uses processing techniques that are not significantly restricted by global brightness and background, making it easily applicable in outdoor conditions. Dust separation was performed using a median filter, and dust density was estimated through a mean shift analysis technique. This dust detection method can perform dust separation and density estimation using only an image of the dust on a translucent window with blurry background.

Real-time UVMS torque distribution algorithm based on weighting matrix

This study presents a real-time algorithm for even distributing the torque burden on the parallel manipulator with an autonomous underwater vehicle (AUV) through the cooperation of the AUV and manipulator. For the redundant resolution of the underwater vehicle manipulator system (UVMS), we used the weighting matrix of the weighted pseudo inverse for kinematic and dynamic modeling. We made dynamic and kinematic modeling using the force distribution characteristics of parallel manipulators. Using the parallel manipulator’s model, the weighting matrix was changed every second to share the manipulator torque with the AUV. The Taguchi method was used to reduce the calculation time for real-time calculation and to perform valve rotation operations with as little torque as possible even in an underwater environment where it is difficult to determine any cause of errors. To demonstrate the effectiveness of this algorithm, we experimented with valve rotation in water using the UVMS. Analysis of the experimental results revealed that the manipulator torque load was greatly reduced due to the AUV load distribution.

OP0108 LORECIVIVINT (SM04690), AN INTRA-ARTICULAR, SMALL-MOLECULE CLK2/DYRK1A INHIBITOR THAT MODULATES THE WNT PATHWAY, PROVIDED CARTILAGE-PROTECTIVE EFFECTS IN AN ANIMAL MODEL OF POST-TRAUMATIC OA

Background:

Osteoarthritis (OA) is characterized by increased cartilage thinning, bone remodeling, and inflammation. Post-traumatic OA, which develops after acute direct trauma to the joints, accounts for approximately 12% of all OA cases.1 Current therapeutic options focus on alleviating symptoms and pain rather than disease modification. Lorecivivint (LOR; SM04690), an intra-articular (IA), small-molecule CLK2/DYRK1A inhibitor that modulates the Wnt pathway, has been shown in animal studies to induce chondrogenesis, protect cartilage, and reduce inflammation and, thereby, improve joint health.2

Objectives:

A single IA LOR injection was evaluated in a rat model of knee instability to determine its protective and regenerative effects when injected at different timepoints after induction of post-traumatic OA.

Methods:

Knee instability/post-traumatic OA was surgically induced in rats by combining anterior cruciate ligament transection with partial medial meniscus transection (ACLT+pMMx). LOR (0.3 ug) or vehicle was injected into the IA space of the damaged knee at 2, 3, or 4 weeks after induction of OA. OA-induced (n=10/group) or sham-operated (surgery without ACLT+pMMx; n=5/group) rats were sacrificed at the injection timepoint (baseline) or 12 weeks following LOR/vehicle injection (study conclusion). Histological grades were evaluated using the summed OARSI scores (stage and grade of cartilage damage)3 of the anterior and posterior medial femoral condyle (MFC) and medial tibial plateau (MTP). Weight distribution analysis was performed using an incapacitance meter at several timepoints. Statistical analysis was performed using one-way ANOVA with Dunnett’s multiple comparison test.

Results:

ACLT+pMMx surgeries led to increased OARSI scores in rats compared with sham surgeries by 2 weeks. LOR treatment at Weeks 2, 3, and 4 led to significant decreases (P<0.05) in total joint OARSI scores (Table 1) at the end of the study compared with vehicle treatment. Rats treated with LOR for 12 weeks and rats at injection baseline had similar OARSI scores, suggesting that LOR treatment arrested the progression of cartilage damage. Significant improvements (P<0.05) were also observed in the weight distribution of LOR-treated rats in the 3- and 4-week groups at 6 and 12 weeks after their respective IA injections compared with vehicle-treated rats.

Table 1.

OARSI scores

Week-2 injectionSham-operated(14 weeks after surgery)Baseline (BL)(2 weeks after surgery)Vehicle(12 weeks after injection)LOR(12 weeks after injection)Total score5.9919.1731.3619.19SEM1.071.552.481.81P value versus BL0.9999P value versus vehicle0.0004Week-3 injectionSham-operated(15 weeks after surgery)Baseline (BL)(3 weeks after surgery)Vehicle(12 weeks after injection)LOR(12 weeks after injection)Total score6.0923.1730.4521.20SEM1.251.361.421.00P value versus BL0.4522P value versus vehicle0.0001Week-4 injectionSham-operated(16 weeks after surgery)Baseline (BL)(4 weeks after surgery)Vehicle(12 weeks after injection)LOR(12 weeks after injection)Total score6.9716.8824.9518.63SEM1.321.041.741.61P value versus BL0.6257P value versus vehicle0.0111

Conclusion:

LOR exhibited cartilage-protective effects and slowed disease progression in the ACLT+pMMx model in vivo and, therefore, has potential as a structure-modifying treatment for OA.

References:

[1]Brown TD, et al. J Orthop Trauma. 2006.

[2]Deshmukh V, et al. Osteoarthr Cartil. 2019.

[3]Pritzker KPH, et al. Osteoarthr Cartil. 2006.

Disclosure of Interests:

Tim Seo Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Vishal Deshmukh Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Yusuf Yazici Shareholder of: Samumed, LLC, Employee of: Samumed, LLC

POS0372 LORECIVIVINT (SM04690), AN INTRA-ARTICULAR, SMALL-MOLECULE CLK2/DYRK1A INHIBITOR THAT MODULATES THE WNT PATHWAY, AS A POTENTIAL TREATMENT FOR MENISCAL INJURIES

Background:

Meniscal injuries are the most common pathology of the knee and are associated with pain, stiffness, and localized swelling. Meniscal damage is a frequent finding on MRI images of knee osteoarthritis (OA).1 Efforts to repair meniscal damage have been largely unsuccessful and do not prevent the progression of degenerative changes that lead to knee OA.2 The Wnt signaling pathway has been shown to be regulated during meniscal development,3 suggesting that manipulation of this pathway may influence the regenerative capacity of the meniscus. Lorecivivint (LOR; SM04690) is an intra-articular (IA), small-molecule CLK2/DYRK1A inhibitor that modulates the Wnt pathway.4

Objectives:

LOR was evaluated in preclinical studies to determine its protective and anabolic effects in ex vivo explants and in a rat model of chemically induced inflammatory meniscal degeneration.

Methods:

Effects of LOR (30 nM) on matrix metalloproteinase (MMP) expression in cultured rat menisci treated with IL-1B were measured by qRT-PCR. In vivo, LOR activity was evaluated in a rat model of monosodium iodoacetate (MIA) injection-induced inflammatory meniscal degeneration. A single IA injection of MIA was immediately followed by a single IA injection of LOR (0.3 ug) or vehicle. Knees were harvested on Days 1, 4, and 11 and menisci were isolated. Anti-inflammatory effects were evaluated by qRT-PCR for TNFA and IL6 expression. Meniscal protection was evaluated by qRT-PCR for MMPs and aggrecanase. Anabolic effects were evaluated by qRT-PCR for collagens.

Results:

In ex vivo meniscal explants, LOR inhibited expression of MMP1, MMP3, and MMP13 compared with DMSO (P<0.01). In vivo, LOR significantly decreased expression of MMPs and aggrecanase (P<0.05) and reduced expression of inflammatory cytokines TNFA and IL6 compared with vehicle in the rat model of inflammatory meniscal degeneration at Day 4 after MIA injection. Additionally, LOR increased expression of collagen types I, II, and III at Day 11 after MIA injection (Figure 1).

Conclusion:

LOR exhibited protective effects in the meniscus ex vivo and in vivo by reducing catabolic enzyme expression compared with control. Anti-inflammatory effects of LOR were demonstrated by inhibition of inflammatory cytokine expression. Compared with vehicle, LOR increased collagen expression in vivo, indicating potential meniscal anabolic effects. These data support further investigation of LOR as a potential structure-modifying treatment for meniscal injuries.

References:

[1]Englund M, et al. Rheum Dis Clin North Am. 2009.

[2]Collins JE, et al. Arthritis Care Res (Hoboken). 2019.

[3]Pazin DE, et al. Dev Dyn. 2012.

[4]Deshmukh V, et al. Osteoarthr Cartil. 2019.

Disclosure of Interests:

Tim Seo Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Vishal Deshmukh Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Yusuf Yazici Shareholder of: Samumed, LLC, Employee of: Samumed, LLC

Effects of body movement on yaw motion in bipedal running lizard by dynamic simulation

Lizards run quickly and stably in a bipedal gait, with their bodies exhibiting a lateral S-shaped undulation. We investigate the relationship between a lizard’s bipedal running and its body movement with the help of a dynamic simulation. In this study, a dynamic theoretical model of lizard is assumed as a three-link consisting of an anterior and posterior bodies, and a tail, with morphometrics based on Callisaurus draconoides. When a lizard runs straight in a stable bipedal gait, its pelvic rotation is periodically synchronized with its gait. This study shows that the S-shaped body undulation with the yaw motion is generated by minimizing the square of joint torque. Furthermore, we performed the biomechanical simulation to figure out the relationship between the lizard’s lateral body undulation and the bipedal running locomotion. In the biomechanical simulation, all joint torques significantly vary by the waist and tail’ motions at the same locomotion. Besides, when the waist and tail joint angles increase, the stride length and duration of the model also increase, and the stride frequency decreases at the same running speed. It means that the lizard’s undulatory body movements increase its stride and help it run faster. In this study, we found the benefits of the lizard’s undulatory body movement and figured out the relationship between the body movement and the locomotion by analyzing the dynamics. In the future works, we will analyze body movements under different environments with various simulators.

Automated technique for high-pressure water-based window cleaning and accompanying parametric study

The maintenance of buildings has become an important issue with the construction of many high-rise buildings in recent years. However, the cleaning of the outer walls of buildings is performed in highly hazardous environments over long periods, and many accidents occur each year. Various robots are being studied and developed to reduce these incidents and to relieve workers from hazardous tasks. Herein, we propose a method of spraying high-pressure water using a pump and nozzle, which differs from conventional methods. The cleaning performance parameters, such as water pressure, spray angle, and spray distance, were optimized using the Taguchi method. Cleaning experiments were performed on window specimens that were contaminated artificially. The cleaning performance of the proposed method was evaluated using the image-evaluation method. The optimum condition was determined based on the results of a sensitive analysis performed on the image data. In addition, the reaction force due to high pressure and impact force on the specimens were investigated. These forces were not sufficient to affect the propeller thrust or cause damage to the building’s surface. We expect to perform field tests in the near future based on the output of this research.

THU0056 SM04755, A POTENTIAL DISEASE-MODIFYING TREATMENT FOR TENDINOPATHY, MODULATES THE WNT PATHWAY VIA INHIBITION OF CLKS AND DYRK1A

Background:

Tendinopathy is an inflammatory and degenerative disorder of tendons caused by injuries and/or overuse. Left untreated, tendinopathy can lead to pain and rupture. Current therapeutic options only treat symptoms. Stem cell- and growth factor-based treatments are under investigation but have not established safety or efficacy, leaving considerable unmet need. The Wnt pathway is upregulated in chronic tendinopathy, affecting inflammation and tenocyte differentiation. SM04755, a novel, topical, small-molecule Wnt pathway inhibitor, has previously been shown to inhibit inflammation, protect tenocytes, and increase tenocyte differentiation in nonclinical models.1

Objectives:

To identify molecular targets of SM04755 and its associated mechanism of action.

Methods:

Wnt pathway inhibition was measured using a cell-based luciferase reporter assay controlled by a β-catenin/TCF-responsive promoter in SW480 colon cancer cells. A kinome screen (318 kinases) and kinase assays were performed. Effects of SM04755 on phosphorylation of proteins, including serine/arginine-rich splicing factor (SRSF) proteins in rat tendon-derived stem cells (rTDSCs) and peripheral blood mononuclear cells (PBMCs), were measured using western blot. SiRNA-mediated knockdown of CDC-like kinases (CLKs) and dual-specificity tyrosine kinase (DYRK1A) were performed in human mesenchymal stem cells (hMSCs), rTDSCs, and rat tenocytes. Effects of SM04755 and siRNA knockdowns on Wnt pathway gene expression and catabolic enzymes (MMPs) were measured using qPCR. SM04755 and siRNA effects on tenocyte marker expression were assessed by qPCR and immunostaining. Effects of SM04755 on LPS-induced expression of inflammatory cytokines in PBMCs were measured by MSD-based ELISA. Statistical analyses used one-way ANOVA for multiple group comparisons and t-tests for comparison between two groups.

Results:

SM04755 was a potent inhibitor (EC50=156 nM) of Wnt signaling. Biochemical assays identified CLKs and DYRK1A as molecular targets of SM04755. SM04755 potently inhibited CLK-mediated phosphorylation of SRSF proteins compared with DMSO controls. Knockdowns of CLKs and DYRK1A led to inhibition of Wnt pathway genes (AXIN2,LEF1,TCF4,TCF7, etc.) compared with siRNA controls (siCtrl). CLK1, 2, and 4 and DYRK1A knockdowns also induced expression of tenocyte markers in rTDSCs and inhibited IL-1β-induced expression of catabolic enzymes (MMP1, 3, 9, 13) in tenocytes compared with siCtrl. SM04755 treatment of LPS-stimulated PBMCs resulted in reduced phosphorylation of NF-kB and STAT3 and inhibited production of inflammatory cytokines compared with DMSO.

Conclusion:

SM04755 inhibited CLKs and DYRK1A, which led to Wnt pathway modulation. Knockdowns of CLKs and DYRK1A, compared with control siRNA, induced tenocyte differentiation and reduced tendon-destroying proteases in tenocytes. This supports the potential disease modification of tendinopathy with SM04755. Furthermore, the anti-inflammatory effects of SM04755 are mechanistically supported by the decreased phosphorylation of STAT3 and NF-kB. These data support that SM04755, as a single agent, may potentially improve symptoms and provide disease modification in tendinopathy. Human tendinopathy trials are planned.

References:

[1]Deshmukh et al.Arthritis and Rheum. 2016

Acknowledgments:

Brian Hofilena for chemistry, Josh Stewart for pharmacokinetics, and Luis Dellamary for formulation.

Disclosure of Interests:

Vishal Deshmukh Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Alyssa O’Green Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Tim Seo Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Yusuf Yazici Shareholder of: Samumed, LLC, Grant/research support from: Bristol-Myers Squibb, Celgene, and Genentech, Consultant of: Celgene and Sanofi, Employee of: Samumed, LLC

AB0069 LORECIVIVINT (SM04690), AN INTRA-ARTICULAR, SMALL-MOLECULE CLK/DYRK1A INHIBITOR THAT MODULATES THE WNT PATHWAY, AS A POTENTIAL TREATMENT FOR MENISCAL INJURIES

Background:

Meniscal injuries, associated with pain, stiffness, and localized swelling, are the most common pathology of the knee with a prevalence of 61 per 100,000.1Meniscal damage is a frequent finding on MRI images of knee osteoarthritis (OA)2; while a meniscal tear can lead to knee OA, knee OA can also lead to a spontaneous meniscal tear.3Efforts to repair meniscal damage have been largely unsuccessful and do not prevent the progression of degenerative changes that lead to knee OA.4The Wnt signaling pathway has been shown to be regulated during meniscal development,5,6suggesting that manipulation of this pathway may influence the regenerative capacity of the meniscus. Lorecivivint (LOR; SM04690) is an intra-articular (IA), small-molecule CLK/DYRK1A inhibitor that modulates the Wnt pathway.

Objectives:

LOR was evaluated in preclinical studies to determine its protective and anabolic effects in ex vivo explants and in a rat model of chemically induced inflammatory meniscus degeneration.

Methods:

Effects of LOR (30 nM) on expression of matrix metalloproteinases (MMPs) in cultured rat menisci treated with IL-1B were measured by qPCR. In vivo, LOR activity was evaluated in a rat model of monosodium iodoacetate (MIA) injection-induced inflammatory meniscus degeneration. A single IA injection of MIA was immediately followed by a single IA injection of LOR (0.3 ug) or vehicle. Knees were harvested on Days 1, 4, and 11 and menisci were isolated. Anti-inflammatory effects were evaluated by measuringTNFAandIL6expression by qPCR. Meniscus protection was evaluated by qPCR for MMPs and aggrecanase and anabolic effects by qPCR for collagens.

Results:

In ex vivo meniscal explants, LOR inhibited expression ofMMP1,MMP3, andMMP13compared to DMSO (P<0.01). In vivo, LOR significantly decreased expression of these MMPs and aggrecanase (P<0.05) compared to vehicle in the rat model of inflammatory meniscus degeneration at Day 4 after MIA injection. In addition, LOR reduced expression of inflammatory cytokinesTNFAandIL6at Day 4 compared to vehicle. Finally, LOR increased expression of collagen types I, II, and III at Day 11 after MIA injection.

Conclusion:

LOR exhibited protective effects in the meniscus ex vivo and in vivo by reducing the expression of catabolic enzymes compared to control. Anti-inflammatory effects of LOR were demonstrated by inhibition of inflammatory cytokine expression. Compared to vehicle, LOR increased expression of collagens in vivo, indicating potential meniscal anabolic effects. These data support further investigation of LOR as a potential disease-modifying therapy for meniscal injuries.

References:

[1]Logerstedt D and Snyder-Mackler L.J Orthop Sports Phys Ther. 2010

[2]Englund M, et al.Rheum Dis Clin North Am. 2009

[3]Englund M, et al.Radiol Clin North Am. 2009

[4]von Lewinski, et al.Knee Surg Sports Traumatol Arthrosc. 2007

[5]Pazin DE, et al.ORS 2012 Annual Meeting. Paper No. 0221

[6]Pazin DE, et al.Dev Dyn. 2012

Disclosure of Interests:

Tim Seo Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Vishal Deshmukh Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Yusuf Yazici Shareholder of: Samumed, LLC, Grant/research support from: Bristol-Myers Squibb, Celgene, and Genentech, Consultant of: Celgene and Sanofi, Employee of: Samumed, LLC

AB0070 LORECIVIVINT (SM04690), A POTENTIAL DISEASE-MODIFYING TREATMENT FOR KNEE OSTEOARTHRITIS, DEMONSTRATED CARTILAGE-PROTECTIVE EFFECTS ON HUMAN OSTEOARTHRITIC EXPLANTS

Background:

Wnt pathway upregulation contributes to knee osteoarthritis (OA) through osteocyte differentiation, cartilage thinning, and inflammation. Lorecivivint (LOR; SM04690), a novel, small-molecule CLK/DYRK1A inhibitor that modulates the Wnt pathway, demonstrated disease-modifying potential for knee OA in preclinical studies.1However, the specific mechanisms by which LOR protects cartilage in knee OA are unclear.

Objectives:

To evaluate the cartilage-protective effects of LOR on human OA explants from total knee replacement (TKR) donors.

Methods:

Knee joint tissue from 22 TKR donors was obtained. IRB approval was obtained from Scripps Health. Cartilage was scored using the Outerbridge classification system based on gross appearance (grade 1=least-damaged tissue, grade 4=most-damaged tissue). Cartilage explants (4 mm in diameter) with Outerbridge grades 2–3 were harvested and cultured for 48 hours to reach metabolic stability. They were then treated with LOR (10 nM, 30 nM) or DMSO and stimulated with either IL-1β (10 ng/ml) or TNF-α (20 ng/ml)+oncostatin M (OM) (10 ng/ml) or left unstimulated. After 72 hours, supernatants and explants were collected. Gene expression of matrix metalloproteinases (MMPs) 1, 3, and 13 was measured by qPCR and protein levels of MMP-1, MMP-3, MMP-13, and thrombospondin-motif-containing disintegrins/metalloproteinases ADAMTS-4 and ADAMTS-5 were measured in supernatants by ELISA. Glycosaminoglycan (GAG) and nitric oxide (NO) levels were measured in supernatants using the dimethylmethylene blue assay and Griess assay, respectively. One-way ANOVA was used for multiple group comparisons.

Results:

Treatment with IL-1β or TNF-α+OM led to statistically significant increases in gene expression ofMMP1,MMP3, andMMP13and increased secretion of GAG, MMP-1, MMP-3, MMP-13, ADAMTS-4, ADAMTS-5, and NO in supernatants compared to unstimulated control. Treatment with LOR decreased both IL-1β-stimulated and TNF-α+OM-stimulated gene expression ofMMP1,MMP3, andMMP13and secretion of GAG, MMP-1, MMP-3, MMP-13, ADAMTS-4, ADAMTS-5, and NO in supernatants compared to treatment with DMSO.

Conclusion:

LOR demonstrated potent inhibition of cartilage catabolism enzyme production in human OA explants compared to controls. These cartilage-protective effects support the development of LOR as a potential disease-modifying treatment for knee OA. Human trials are ongoing.

References:

[1]Deshmukh V, et al.Osteoarthr Cartil. 2019.

Disclosure of Interests:

Vishal Deshmukh Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Shawn Grogan: None declared, Tim Seo Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, Deepti Bhat Shareholder of: Samumed, LLC, Employee of: Samumed, LLC, William Bugbee: None declared, Darryl D’Lima: None declared, Yusuf Yazici Shareholder of: Samumed, LLC, Grant/research support from: Bristol-Myers Squibb, Celgene, and Genentech, Consultant of: Celgene and Sanofi, Employee of: Samumed, LLC

Modulation of the Wnt pathway through inhibition of CLK2 and DYRK1A by lorecivivint as a novel, potentially disease-modifying approach for knee osteoarthritis treatment

OBJECTIVES

Wnt pathway upregulation contributes to knee osteoarthritis (OA) through osteoblast differentiation, increased catabolic enzymes, and inflammation. The small-molecule Wnt pathway inhibitor, lorecivivint (SM04690), which previously demonstrated chondrogenesis and cartilage protection in an animal OA model, was evaluated to elucidate its mechanism of action.

DESIGN

Biochemical assays measured kinase activity. Western blots measured protein phosphorylation in human mesenchymal stem cells (hMSCs), chondrocytes, and synovial fibroblasts. siRNA knockdown effects in hMSCs and BEAS-2B cells on Wnt pathway, chondrogenic genes, and LPS-induced inflammatory cytokines was measured by qPCR. In vivo anti-inflammation, pain, and function were evaluated following single intra-articular (IA) lorecivivint or vehicle injection in the monosodium iodoacetate (MIA)-induced rat OA model.

RESULTS

Lorecivivint inhibited intranuclear kinases CDC-like kinase 2 (CLK2) and dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A). Lorecivivint inhibited CLK2-mediated phosphorylation of serine/arginine-rich (SR) splicing factors and DYRK1A-mediated phosphorylation of SIRT1 and FOXO1. siRNA knockdowns identified a role for CLK2 and DYRK1A in Wnt pathway modulation without affecting β-catenin with CLK2 inhibition inducing early chondrogenesis and DYRK1A inhibition enhancing mature chondrocyte function. NF-κB and STAT3 inhibition by lorecivivint reduced inflammation. DYRK1A knockdown was sufficient for anti-inflammatory effects, while combined DYRK1A/CLK2 knockdown enhanced this effect. In the MIA model, lorecivivint inhibited production of inflammatory cytokines and cartilage degradative enzymes, resulting in increased joint cartilage, decreased pain, and improved weight-bearing function.

CONCLUSIONS

Lorecivivint inhibition of CLK2 and DYRK1A suggested a novel mechanism for Wnt pathway inhibition, enhancing chondrogenesis, chondrocyte function, and anti-inflammation. Lorecivivint shows potential to modify structure and improve symptoms of knee OA.

Switching PD-based sliding mode control for hovering of a tilting-thruster underwater robot

This paper presents a switching PD-based sliding mode control (PD-SMC) method for the 6-degree-of-freedom (DOF) hovering motion of the underwater robot with tilting thrusters. Four thrusters of robot can be tilted simultaneously in the horizontal and vertical directions, and the 6-DOF motion is achieved by switching between two thruster configurations. Therefore, the tilting speed of thruster becomes the most essential parameter to determine the stability of hovering motion. Even though the previous PD control ensures stable hovering motion within a certain ranges of tilting speed, a PD-SMC is suggested in this paper by combining PD control with sliding mode control in order to achieve acceptable hovering performance even at the much lower tilting speeds. Also, the sign function in the sliding mode control is replaced by a sigmoid function to reduce undesired chattering. Simulations show that while PD control is effective only for tilting duration of 600 ms, the PD-based sliding mode control can guarantee the stable hovering motion of underwater robot even for the tilting duration of up to 1500 ms. Extensive experimental results confirm the hovering performance of the proposed PD-SMC method is much superior to that of PD method for much larger tilting durations.

A small-molecule inhibitor of the Wnt pathway (SM04690) as a potential disease modifying agent for the treatment of osteoarthritis of the knee

OBJECTIVES

Osteoarthritis (OA) is a degenerative disease characterized by loss of cartilage and increased subchondral bone within synovial joints. Wnt signaling affects the pathogenesis of OA as this pathway modulates both the differentiation of osteoblasts and chondrocytes, and production of catabolic proteases. A novel small-molecule Wnt pathway inhibitor, SM04690, was evaluated in a series of in vitro and in vivo animal studies to determine its effects on chondrogenesis, cartilage protection and synovial-lined joint pathology.

DESIGN

A high-throughput screen was performed using a cell-based reporter assay for Wnt pathway activity to develop a small molecule designated SM04690. Its properties were evaluated in bone-marrow-derived human mesenchymal stem cells (hMSCs) to assess chondrocyte differentiation and effects on cartilage catabolism by immunocytochemistry and gene expression, and glycosaminoglycan breakdown. In vivo effects of SM04690 on Wnt signaling, cartilage regeneration and protection were measured using biochemical and histopathological techniques in a rodent acute cruciate ligament tear and partial medial meniscectomy (ACLT + pMMx) OA model.

RESULTS

SM04690 induced hMSC differentiation into mature, functional chondrocytes and decreased cartilage catabolic marker levels compared to vehicle. A single SM04690 intra-articular (IA) injection was efficacious in a rodent OA model, with increased cartilage thickness, evidence for cartilage regeneration, and protection from cartilage catabolism observed, resulting in significantly improved Osteoarthritis Research Society International (OARSI) histology scores and biomarkers, compared to vehicle.

CONCLUSIONS

SM04690 induced chondrogenesis and appeared to inhibit joint destruction in a rat OA model, and is a candidate for a potential disease modifying therapy for OA.

Acetylation changes at lysine 5 of histone H4 associated with lytic gene promoters during reactivation of Kaposi's sarcoma-associated herpesvirus

Kaposi's sarcoma-associated herpesvirus (KSHV) is a pathogenic agent of Kaposi's sarcoma, primary effusion lymphoma and multicentric Castleman's disease in humans. Similarly to other gammaherpesviruses such as Epstein-Barr virus (EBV) and herpesvirus saimiri (HVS), KSHV displays two alternative life cycles, latent and lytic one. The transactivation from latency to the lytic phase is the result of transcriptional changes in the KSHV genome caused by the replication and transcriptional activator (RTA). During KSHV reactivation, epigenetic modifications of histone protein on the viral genome occur, which regulate the transcriptional activation of a number of lytic genes. The reactivation of EBV from latency to lytic cycle, induced by an immediate-early Zta protein, was shown to be accompanied by acetylation of specific lysines in histone H4. Accordingly, we hypothesized that the RTA-induced transactivation of KSHV could also be accompanied by histone acetylation. To validate this hypothesis, we assayed alterations of acetyl-histone H4-lysine 5 (acH4K5) during the RTA-mediated KSHV reactivation. While the modified histone protein in a total cell lysate was not distinguished between control and RTA-expressed cells, upregulated acH4K5 was detected on several lytic gene promoter regions during KSHV reactivation. Our results clearly indicate that this epigenetic change is related to transcription of genes expressed in the lytic cycle of KSHV.

A method of reducing background radiance for emissivity-compensated radiation thermometry of silicon wafers

We studied the spectral and directional emissivities of silicon wafers using an optical polarization technique. Based on simulation and experimental results, we developed two radiation thermometry methods for silicon wafers: one is based on the polarized emissivity-invariant condition and the other is based on the relationship between the ratio of the p- and s-polarized radiance and the polarized emissivity. These methods can be performed at temperatures above 600 °C and over a wide wavelength range (0.9-4.8 μm), irrespective of the dielectric film thickness and the substrate resistivity, which depends on the dopant concentration. The temperature measurements were estimated to have expanded uncertainties (k = 2) of less than 5 °C. With a view to practically applying these methods, we investigated a method to reduce the intense background radiance produced by high-intensity heating lamps. We found that the background radiance can be greatly reduced by using a radiometer that is sensitive to wavelengths of 4.5 or 4.8 μm and suitable geometrical arrangements of a quartz plate. This opens up the possibility of using the two proposed radiation thermometry methods in practical applications.

Radionuclide Transport by Groundwater Colloids at the Koongarra Uranium Deposit

Groundwater and entrained particles were sampled from several boreholes at the Koongarra uranium deposit in the Northern Territory of Australia. Conventional filtration techniques, hollow fibre ultrafiltration, and stirred-cell ultrafiltration were used to separate dissolved species, large particles (> 1 μm) and colloids (< 1 μm). The colloids and particles included clay minerals, particularly kaolinite, and chlorite, together with fine quartz grains. Iron was present as particle coatings, and in a separate colloidal form. The amount of238U associated with colloids (expressed as a percentage of the total238U which passed through the 1.0 μm filter) ranged up to 6.5%. The corresponding figures for Th were 10-85%. However, the amount of230Th which passed through the 1.0 μm filter was extremely small, and230Th was associated to a much greater extent with larger particles, which are unlikely to be mobile in natural groundwaters. In some fine particle and colloidal fractions, the227Th/230Th activity ratio in the thorium alpha spectrum was unusually high, indicating the presence of substantial quantities of227Ac. This suggested that actinium could be present as a mobile colloid phase. Overall, there was very little colloidal material in these groundwaters, with only iron, uranium, actinium, and thorium showing a significant association with colloids.

Diagnosis and treatment of obscure gastrointestinal bleeding using combined capsule endoscopy and double balloon endoscopy: 1-year follow-up study

BACKGROUND AND STUDY AIMS

Several studies have shown the value of capsule endoscopy and double balloon endoscopy (DBE) in small-intestinal bleeding. The purpose of this study was to evaluate the impact of capsule endoscopy results on subsequent DBE examination, and the 1-year clinical outcome of this combined approach in patients with obscure gastrointestinal bleeding (OGIB).

PATIENTS AND METHODS

A total of 45 consecutive patients with OGIB underwent capsule endoscopy. Patients with positive capsule endoscopy results underwent DBE for biopsy or therapy, and those with negative results underwent further assessment for possible diagnostic misses on capsule endoscopy. Tumors, ulcerations, and vascular lesions were considered as sources of bleeding. Diagnoses of OGIB lesions and clinical outcome were assessed 1 year after these examinations.

RESULTS

Responsible lesions were found in 22 patients (49 %): 19 lesions in 18/45 patients (40 %) undergoing capsule endoscopy, and 18/36 patients (50 %) undergoing subsequent DBE. In all, 10 tumors, nine vascular lesions, and four ulcerations were found. In two patients, vascular lesions were only later diagnosed by conventional methods (4 %). Capsule endoscopy results guided our choice of the proper DBE model for successful therapeutic intervention in five patients. Re-bleeding rates were low during 1-year follow-up of the entire group (mean follow-up, 18.8 months): 5 % in cases with positive diagnoses on capsule endoscopy and/or DBE, and 12 % in negative cases.

CONCLUSIONS

A combined approach using capsule endoscopy followed by DBE proves valuable in the diagnosis and treatment of patients with OGIB, leaves a low rate of undiagnosed bleeding sources, and has a good long-term outcome.

Effects of intracerebroventricular infusions of arginine vasopressin in sheep

In sheep, neither the in vivo effect of vasopressin administered by a method other than systemic infusion nor the central effects on behavior from the perspective of stress regulation has been fully elucidated in an intact animal. We examined changes in behavioral, adrenocorticotropic, and autonomic nervous functions after intracerebroventricular infusions of arginine vasopressin (AVP) to elucidate its central role. Intracerebroventricular infusions of AVP (0, 0.12, 1.2 and 12 microg/500 microl/30 min) evoked a dose-related increase in plasma cortisol concentration. There were significant treatment-related effects on the total duration of sham-chewing (Friedman's test, X2=12.75, p=.0052), on the total duration of bar-biting (Friedman's test, X2=15.0, p=.0018), and on the total duration of rubbing (Friedman's test, X2=12.0, p=.0074). AVP 12 microg treatment induced a greater degree of sham-chewing and bar-biting than the other three treatments did (Nemenyi multiple comparisons: p<0.1). These findings indicate, together with our previous findings, that AVP has the same corticotropic potential as corticotropin-releasing hormone infused intracerebroventricularly in equal molar concentrations. Although the degree to which central stress signaling pathways are involved in these responses remains speculative, the relationships between stereotypies and central AVP are of particular interest.

Monocyte chemoattractant protein 1 and macrophage cyclooxygenase 2 expression in colonic adenoma

BACKGROUND AND AIMS

Cyclooxygenase 2 (COX-2) expression in subepithelial macrophages of colorectal adenoma has been suggested as the first in a series of steps leading to colorectal tumorigenesis. We tested the hypothesis that chemokines released from human colorectal adenoma epithelium might be involved in COX-2 expression in macrophages of the lamina propria.

METHODS

Endoscopic samples of sporadic colorectal adenomas were tested by enzyme linked immunosorbent assay for chemokines involved in macrophage chemotaxis. Localisation of adenoma macrophage chemoattractant protein 1 (MCP-1) and COX-2 were determined by immunohistochemistry. The effects of MCP-1, in the presence or absence of celecoxib, on COX-2 expression, and prostaglandin (PG) E(2) and vascular endothelial growth factor (VEGF) release, were examined in human macrophages isolated from peripheral blood.

RESULTS

MCP-1 levels were markedly higher in adenoma with mild-moderate dysplasia (129.7 (19.9) pg/mg protein) and severe dysplasia (227.9 (35.4) pg/mg protein) than in normal colonic mucosa (55.8 (4.2) pg/mg protein). Other chemokine levels, macrophage inflammatory proteins (MIP)-1alpha and MIP-1beta, and the chemokine regulated on activation of normal T cell expressed and secreted (RANTES) did not vary significantly between adenoma and normal mucosa. MCP-1 levels in both adenoma and normal colonic mucosa increased significantly three hours after tissue cultivation in vitro. MCP-1 immunoreactivity was restricted to the adenoma epithelium, with no reactivity seen in adjacent normal epithelial cells. MCP-1 stimulated COX-2 expression and PGE(2) and VEGF release in human macrophages. Celecoxib, a selective COX-2 inhibitor, inhibited MCP-1-induced PGE(2) and VEGF release in macrophages. Addition of exogenous PGE(2) reversed this inhibitory effect on VEGF release, suggesting that MCP-1 in adenoma epithelial cells might be involved in COX-2 expression and subsequent macrophage activation.

CONCLUSIONS

MCP-1 in colorectal adenoma epithelial cells might be involved in macrophage migration and COX-2 expression, leading to the subsequent development of colonic adenoma.

Reversal of portal flow after acute rejection in living-donor liver transplantation

Portal hepatofugal flow is rare after liver transplantation. We experienced a case in which hepatofugal portal flow was observed in acute rejection. A 6-year-old boy with glycogen storage disease type Ia underwent living-donor liver transplantation. On postoperative day 7, portal venous peak velocity was markedly decreased without portal thrombosis and obstruction of the hepatic vein, and hepatic arterial peak velocity increased reciprocally. Based on a diagnosis of acute rejection, made on postoperative day 8, we initiated steroid pulse therapy. Despite the employment of this therapy, continuous hepatofugal portal flow was observed in the entire liver on postoperative day 8. On day 12, as the liver disorder progressed, the Doppler waveform in the portal vein changed from continuous to pulsatile hepatofugal flow. The patient died of liver failure on day 14. The histological findings of a biopsy specimen on day 9 showed centrilobular necrosis, while total hepatocellular necrosis was seen at autopsy. Hepatofugal flow after liver transplantation is considered to be an ominous sign caused by several factors, and its appearance indicates a fatal condition.

[Audiological and equilibrium study of perilymphatic fistulas]

We clinically analyzed 15 cases of perilymphatic fistulas--11 caused by barotraumas and 4 idiopathic--identified by surgery between March 1995 and March 1999 at the Hyogo College of Medicine and affiliated hospitals. Subjects were 11 men and 4 women (aged 14 to 79 years (mean: 46.7 years)). All showed hearing loss in audiography and 12 cases reported tinnitus--stream-like in 5 and poping in 4. Dysequilibrium was seen in 9 cases. Perilymph leakage was detected intraoperatively from the oval window in 9, from the round window in 4, and from both windows in 1, while another had leakage from the fissura ante fenestram. After surgery, hearing level improved by over 10 dB in 9 of the 11 cases operated on within 14 days after onset. Hearing did not improve in 3 of 4 operated on later. Vertigo disappeared after surgery. Dizziness tended to persist in those having canal paresis or paralytic nystagmus before surgery. We suggest that patients with progressive hearing loss should be operated on as soon as possible and that patients with dysequilibrium or without response to conservative treatment undergo surgery within 14 days of onset.

Long-term follow-up of the clinical efficacy of chemotherapy for acute myeloid leukemia at a single institute

A retrospective study was performed on 125 patients with de-novo acute myeloid leukemia (AML) who had received first remission induction therapy at Fukui Medical University Hospital in the 16 years between 1983 and 1998. For remission induction therapies, patients in the 1980s received mainly behenoylcytarabine (BHAC), 6-mercaptopurine (6-MP), and prednisolone (PSL), plus aclarubicin (ACR) or daunorubicin (DNR). Patients in the 1990s received mainly BHAC, 6-MP, and etoposide (VP-16) plus DNR or mitoxantrone (MIT) or idarubicin (IDA). Patients with hypoplastic bone marrow received low-dose cytarabine (Ara-C) therapy or cytarabine ocfosfate (SPAC). Since 1992, patients with French-American-British disease classification of M3 have received all-trans retinoic acid (ATRA) (+/-chemotherapy). In the 1990s, more intensified postremission therapy was performed compared with that done in the 1980s. The complete remission (CR) rate of all patients was 58%. Predicted 6-year overall survival (OS) and disease-free survival (DFS) rates in the CR patients were 22% and 28%, respectively. Multivariate analysis showed age and leukocyte counts as significant prognostic factors regarding CR, OS, and DFS rates. The CR and OS rates in the 1990s were improved significantly from those in the 1980s, at 69% versus 48% (P = 0.016), and 32% versus 15% (P = 0.0014), respectively. The early death rate, within 30 days, was decreased from 26% in the 1980s to 9% in the 1990s (P = 0.013). This decrease was thought to be the main cause of the high CR rate in the 1990s. However, DFS was not significantly improved. It is necessary to establish more effective postremission therapies in order to reduce the relapse rate and improve the prognosis.

Viral interferon regulatory factor 1 of Kaposi's sarcoma-associated herpesvirus binds to p53 and represses p53-dependent transcription and apoptosis

Kaposi's sarcoma-associated herpesvirus (KSHV) is related to the development of Kaposi's sarcoma. Open reading frame K9 of KSHV encodes viral interferon regulatory factor 1 (vIRF1), which functions as a repressor of interferon- and IRF1-mediated signal transduction. In addition, vIRF1 acts as an oncogene to induce cellular transformation. Here we show that vIRF1 directly associates with the tumor suppressor p53 and represses its functions. The vIRF1 interaction domains of p53 are the DNA binding domain (amino acids [aa] 100 to 300) and the tetramerization domain (aa 300 to 393). p53 interacts with the central region (aa 152 to 360) of vIRF1. vIRF1 suppresses p53-dependent transcription and deregulates its apoptotic activity. These results suggest that vIRF1 may regulate cellular function by inhibiting p53.