Local Shear Deformation in Whole Cartilage Explants Determined by Texture Correlation

2011 ◽  
Author(s):  
Jonathan T. Henderson ◽  
Garrett Shannon ◽  
Kai Yuen ◽  
Corey P. Neu
Keyword(s):  
The United States ◽  
Cartilage Explants ◽  
Mechanical Stimuli ◽  
Cartilage Homeostasis ◽  
Cellular Mechanotransduction ◽  
Wear And Tear ◽  
Prevalent Disease ◽  
Local Shear ◽  
Mechanical Factors ◽  
Shear Strains

Osteoarthritis (OA) is a prevalent disease, afflicting 27 million people in the United States alone [1]. OA is commonly thought of as “wear and tear” of the joints caused by repeated compression and shear strains. The mechanical contribution to the onset and progression of OA is unknown; however, it is likely a result of an imbalance of cartilage homeostasis, represented by a shift in biochemical and mechanical factors that typically maintain healthy joints [2]. Cartilage homeostasis results in part from cellular mechanotransduction events, i.e. the conversion of mechanical stimuli into a biochemical response.

scholarly journals Induction of WNT16 via Peptide-mRNA Nanoparticle-Based Delivery Maintains Cartilage Homeostasis

Pharmaceutics ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 73
Author(s):  
Huimin Yan ◽  
Ying Hu ◽  
Antonina Akk ◽  
Muhammad Farooq Rai ◽  
Hua Pan ◽  
...  
Keyword(s):  
Messenger Rna ◽  
Treatment Options ◽  
Cartilage Explants ◽  
Joint Disease ◽  
Chondrocyte Apoptosis ◽  
Proof Of Concept ◽  
Human Cartilage ◽  
Cartilage Homeostasis ◽  
Wide Range ◽  
Significant Disability

Osteoarthritis (OA) is a progressive joint disease that causes significant disability and pain and for which there are limited treatment options. We posit that delivery of anabolic factors that protect and maintain cartilage homeostasis will halt or retard OA progression. We employ a peptide-based nanoplatform to deliver Wingless and the name Int-1 (WNT) 16 messenger RNA (mRNA) to human cartilage explants. The peptide forms a self-assembled nanocomplex of approximately 65 nm in size when incubated with WNT16 mRNA. The complex is further stabilized with hyaluronic acid (HA) for enhanced cellular uptake. Delivery of peptide-WNT16 mRNA nanocomplex to human cartilage explants antagonizes canonical β-catenin/WNT3a signaling, leading to increased lubricin production and decreased chondrocyte apoptosis. This is a proof-of-concept study showing that mRNA can be efficiently delivered to articular cartilage, an avascular tissue that is poorly accessible even when drugs are intra-articularly (IA) administered. The ability to accommodate a wide range of oligonucleotides suggests that this platform may find use in a broad range of clinical applications.

scholarly journals Aetiological Factors of Osteoarthritis: A Review Update

2015 ◽  
Vol 2 (1) ◽  
pp. 18-23
Author(s):  
M. Jahidul Islam ◽  
M. Shahadat Hossain ◽  
M. Ruhul Amin ◽  
Monzur Ahmed
Keyword(s):  
United States ◽  
Joint Damage ◽  
The Elderly ◽  
The United States ◽  
Common Type ◽  
High Rate ◽  
Lumbosacral Spine ◽  
First Metatarsal ◽  
High Prevalence ◽  
Wear And Tear

Osteoarthritis (OA) is no longer considered ‘degenerative’ or ‘wear and tear’ arthritis; rather involves dynamic biomechanical, biochemical and cellular process. Indeed, the joint damage that occurs in OA is the result of active remodeling involving all the joint structures. Although articular cartilage is at the center of change, OA is viewed as a disease of the entire joint. Traditionally, OA has been viewed as an inevitable degenerative condition of the cartilage. It is currently viewed as a biomechanical and biochemical inflammatory disease of the entire joints. Osteoarthritis (OA) is the most common type of arthritis. Its high prevalence, especially in the elderly, and the high rate of disability related to disease make it a leading cause of disability in the elderly. Because of the aging of Western populations and because obesity, a major risk factor, are increasing in prevalence, the occurrence of osteoarthritis is on the rise. In the United States, osteoarthritis prevalence will increase from 66–100% by the year 2020. OA affects certain joints, yet spares others. Commonly affected joints include the cervical and lumbosacral spine, hip, knee, and first metatarsal phalangeal joint (MTP). In the hands, the distal and proximal inter-phalangeal joints and the base of the thumb are often affected. Usually spared are the wrist, elbow, and ankle.Journal of Current and Advance Medical Research 2015;2(1):18-23DOI: http://dx.doi.org/10.3329/jcamr.v2i1.22584

Cohesive interface behaviour and local shear strains in axially loaded composite annular tubes

2017 ◽  
Vol 160 ◽  
pp. 1126-1135 ◽  
Author(s):  
Agostina Orefice ◽  
Geminiano Mancusi ◽  
Luciano Feo ◽  
Fernando Fraternali
Keyword(s):  
Cohesive Interface ◽  
Local Shear ◽  
Shear Strains ◽  
Axially Loaded ◽  
Interface Behaviour

The Mechanical Properties of Porcine Coronary Arteries Determined With a Mixed Experimental-Numerical Approach

2008 ◽  
Author(s):  
Arjen van der Horst ◽  
Chantal N. van den Broek ◽  
Marcel C. M. Rutten ◽  
Frans N. van de Vosse
Keyword(s):  
United States ◽  
Mechanical Properties ◽  
Coronary Arteries ◽  
Arterial Wall ◽  
Coronary Circulation ◽  
Mechanical Characterization ◽  
Numerical Approach ◽  
The United States ◽  
Mechanical Factors

Mechanical characterization of the coronary arterial wall is important for several reasons. Mechanical factors play an important role in the development of atherosclerosis [1]. Atherosclerotic coronary arteries may be treated mechanically with interventions like PTCA and stent implantation, 1265000 PTCA procedures were performed in the United States in 2005 [2]. Furthermore, knowledge of the mechanical properties of the arterial wall is important for modeling of the coronary circulation and explaining its hemodynamics.

Characterization of the Poroelastic Material Properties of Skeletal Repair Tissues Using Microindentation

2011 ◽  
Author(s):  
M. M. Sperry ◽  
L. N. M. Hayward ◽  
G. J. Miller ◽  
E. F. Morgan
Keyword(s):  
Material Properties ◽  
Repair Process ◽  
The United States ◽  
Fracture Site ◽  
Fe Model ◽  
Fracture Callus ◽  
Repetitive Injury ◽  
Poroelastic Material ◽  
Mechanical Factors ◽  
Callus Tissues

Nearly 10% of the approximately six million fractures that occur each year in the United States do not heal, causing lasting pain and repetitive injury [1]. Although the causes of poor healing are unknown in many cases, the sensitivity of the repair process to mechanical factors is well established. In an effort to understand how mechanical factors such as axial and shear micromotion at the fracture site affect healing, prior studies have sought to characterize the local mechanical environment using finite element (FE) analysis (e.g., [2,3]). However, a key set of inputs for the FE analyses is the distribution of material properties of the various tissues that comprise the fracture callus. Recent studies using nano- and microindentation have estimated these properties by approximating the tissues as linear elastic [4,5]. As a next step in this line of inquiry, the overall goal of this study was to estimate the linear, poroelastic material properties of callus tissues. The specific objectives were: 1) to develop an FE model for use in simulating microindentation experiments; and 2) to compare the results of the simulation to experimental microindentation data in order to derive the mechanical properties of the healing tissues.

Pharmacotherapy of Chronic Heart Failure in the Elderly: A Review of the Evidence

2010 ◽  
Vol 2 ◽  
pp. CMT.S2794
Author(s):  
Toni L. Ripley ◽  
Thomas A. Hennebry
Keyword(s):  
Heart Failure ◽  
Clinical Trials ◽  
Older Patients ◽  
The Elderly ◽  
The United States ◽  
Response To Therapy ◽  
Clinical Endpoints ◽  
Age Related ◽  
Prevalent Disease ◽  
To Receive

Heart failure (HF) is a very prevalent disease in the United States and in Europe, with the highest prevalence among older patients. Population estimates suggest substantial growth among the elderly over the next four decades. However, older patients are underrepresented in clinical trials evaluating HF therapies and are less likely to receive the medications shown in these trials to reduce the morbidity and mortality associated with HF. Age-related differences exist in cardiovascular function that may affect disease progression, clinical presentation, and/or response to therapy. Further, medication use in older patients is complicated by physiologic changes in pharmacokinetics and the presence of multiple co-morbidities, which leads to polypharmacy and the related complications. We reviewed the pharmacotherapy clinical trials in HF to review the results specifically in older patients. Trials were included in this review if clinical endpoints were evaluated, if data regarding the participants’ age was reported, and if the intervention studied was in a medication class that is generally recommended for patients with HF by published guidelines. Although some non-randomized data shows benefits of standard therapies may be maintained among patients with HF ≥ 60 years old, the randomized controlled trials that have been published to date showed no benefit and no harm in this group. Cautious HF management among older patients is critical as additional evidence is pursued.

Eosinophilic Esophagitis: A Prevalent Disease in the United States That Affects All Age Groups

2008 ◽  
Vol 134 (5) ◽  
pp. 1316-1321 ◽  
Author(s):  
Robert C. Kapel ◽  
Jocelyne K. Miller ◽  
Carlos Torres ◽  
Saime Aksoy ◽  
Richard Lash ◽  
...  
Keyword(s):  
United States ◽  
Eosinophilic Esophagitis ◽  
Age Groups ◽  
The United States ◽  
Prevalent Disease

METHOD OF PAINT COAT DURABILITY ASSESSMENT EXPOSED TO MINERAL MASS

Tribologia ◽  
2018 ◽  
Vol 278 (2) ◽  
pp. 123-131
Author(s):  
Piotr SZCZYGLAK
Keyword(s):  
Original Method ◽  
Mechanical Forces ◽  
Rotating Drum ◽  
Testing Method ◽  
Wear And Tear ◽  
Durability Assessment ◽  
Testing Stand ◽  
Mechanical Factors ◽  
The Impact ◽  
Mineral Mass

This study analyses issues concerning defects of passive paint coats. Four reasons of their occurrence have been identified: constructional, technological, operational, and caused by wear and tear. Standardized methods of paint coat assessment are discussed based on the impact of mechanical factors (PN-EN ISO 2409:2013-06, ASTM D3359-17, PN-EN ISO 1522:2008, PN-EN ISO 4624:2016-05, PN-EN ISO 1518-1:2011, PN-EN ISO 16276-2:2008, PN-EN ISO 6272:2011, PN-EN ISO 6860:2006, PN-EN ISO 2815:2004, PN-EN ISO 1519:2000). The original method of paint coat durability evaluation is presented with the consideration of synergetic impact of mechanical forces. This method permits carrying out testing in conditions close to those during normal service. The testing stand equipped with a rotating drum filled with mineral mass has been described as well as the optical method of assessing paint coat quality using original software developed by authors. Tests for three coating systems were carried out in order to present the possibilities of the developed method. In summary, the conclusions relating to the presented testing method are presented.

scholarly journals Is Footedness Driving Right Lower Extremity Arthroplasty Becoming Commoner Than Left Lower Extremity Arthroplasty?

2021 ◽  
Author(s):  
Deepak Gupta
Keyword(s):  
Lower Extremity ◽  
Automatic Transmission ◽  
Revision Arthroplasty ◽  
The United States ◽  
Left Lower Extremity ◽  
Institutional Review ◽  
Number Of Patients ◽  
Wear And Tear ◽  
Primary Hip Arthroplasty ◽  
Set Up

The question arises whether footedness transforms into asymmetrical incidence of wear and tear within lower extremity joints. After obtaining institutional review board approval for exempt research, the author manually counted the number of patients who underwent right or left or bilateral, hip or knee, primary or revision arthroplasty over a five-year period (2016-2020) at a university-affiliated hospital in the United States. Overall, right lower extremity arthroplasty was significantly commoner than left lower extremity arthroplasty (P=0.002). Individually, only right primary hip arthroplasty (P=0.033) and right revision knee arthroplasty (P=0.041) were significantly commoner procedures than their left counterparts. These results should set up the stage for future investigations into footedness retrospectively and prospectively to rule out if commoner right footedness in itself is driving this asymmetrical incidence of lower extremity arthroplasty or whether automatic transmission vehicular driving is independently contributing to this asymmetrical incidence.

scholarly journals Further decoding the mystery of American pain: The importance of work

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0261891
Author(s):  
David G. Blanchflower ◽  
Alex Bryson
Keyword(s):  
United States ◽  
Life Course ◽  
The Elderly ◽  
The United States ◽  
Cross Sectional ◽  
Wear And Tear ◽  
Educational Groups ◽  
Employment Rates ◽  
The Life Course ◽  
What Matters

A recent paper showed that, whereas we expect pain to rise with age due to accumulated injury, physical wear and tear, and disease, the elderly in America report less pain than those in midlife. Further exploration revealed this pattern was confined to the less educated. The authors called this the ‘mystery of American pain’ since pain appears to rise with age in other countries irrespective of education. Revisiting this issue with the same cross-sectional data we show that what matters in explaining pain through to age 65 is whether one is working or not. The incidence of pain across the life-course is nearly identical for workers in America and elsewhere, but it is greater for non-working Americans than it is for non-workers elsewhere. As in other countries, pain is hump-shaped in age among those Americans out of work but rises a little over the life-course for those in work. Furthermore, these patterns are apparent within educational groups. We show that, if one ascribes age-specific employment rates from other OECD countries to Americans, the age profile of pain in the United States is more similar to that found elsewhere in the OECD. This is because employment rates are lower in the United States than elsewhere between ages 30 and 60: the simulation reduces the pain contribution of these non-workers to overall pain in America, so it looks somewhat similar to pain elsewhere. We conclude that what matters in explaining pain over the life-course is whether one is working or not and once that is accounted for, the patterns are consistent across the United States and the rest of the OECD.

Sign in / Sign up

Export Citation Format

Share Document