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1.
Nature ; 602(7896): 251-257, 2022 02.
Article in English | MEDLINE | ID: mdl-35140390

ABSTRACT

The development of high-performance ultraelastic metals with superb strength, a large elastic strain limit and temperature-insensitive elastic modulus (Elinvar effect) are important for various industrial applications, from actuators and medical devices to high-precision instruments1,2. The elastic strain limit of bulk crystalline metals is usually less than 1 per cent, owing to dislocation easy gliding. Shape memory alloys3-including gum metals4,5 and strain glass alloys6,7-may attain an elastic strain limit up to several per cent, although this is the result of pseudo-elasticity and is accompanied by large energy dissipation3. Recently, chemically complex alloys, such as 'high-entropy' alloys8, have attracted tremendous research interest owing to their promising properties9-15. In this work we report on a chemically complex alloy with a large atomic size misfit usually unaffordable in conventional alloys. The alloy exhibits a high elastic strain limit (approximately 2 per cent) and a very low internal friction (less than 2 × 10-4) at room temperature. More interestingly, this alloy exhibits an extraordinary Elinvar effect, maintaining near-constant elastic modulus between room temperature and 627 degrees Celsius (900 kelvin), which is, to our knowledge, unmatched by the existing alloys hitherto reported.

2.
Phys Rev Lett ; 132(5): 056101, 2024 Feb 02.
Article in English | MEDLINE | ID: mdl-38364152

ABSTRACT

The slow transition from an out-of-equilibrium glass towards a supercooled liquid is a complex relaxation phenomenon. In this Letter, we study the correlation between mechanical relaxation and equilibration kinetics in a Pd_{20}Pt_{20}Cu_{20}Ni_{20}P_{20} high-entropy metallic glass. The evolution of stress relaxation with aging time was obtained with an unprecedented detail, allowing us to pinpoint new interesting features. The long structural relaxation towards equilibrium contains a wide distribution of activation energies, instead of being just associated to the ß relaxation as commonly accepted. The stress relaxation time can be correlated with the equilibration rate and we observe a decrease of microstructural heterogeneity which contrasts with an increase of dynamic heterogeneity. These results significantly enhance our insight of the interplay between relaxation dynamics and thermodynamics in metallic glasses.

3.
Am J Emerg Med ; 84: 74-80, 2024 Jul 29.
Article in English | MEDLINE | ID: mdl-39096712

ABSTRACT

BACKGROUND: Osteopathic manipulative treatment (OMT), also known as osteopathic manipulative medicine (OMM), is a set of manual techniques, developed by Dr. Andrew Taylor Still, founder of osteopathic medicine, initially limited to osteopathic medicine, for the treatment of painful conditions. This toolset is now used by allopathic physicians, international osteopaths, physical therapists, chiropractors, and other healthcare workers for the treatment of musculoskeletal pain. OMT can be used in the emergency department (ED) for the treatment of musculoskeletal complaints as an adjunct to pharmacologic agents (e.g., NSAIDs), or an alternative to opioids. OBJECTIVE: This narrative review provides emergency clinicians with an understanding of OMT, including a broad overview of the basis, development, and common subtypes of OMT; data on OMT efficacy and on the use of conditions commonly encountered in the ED setting; and information on how to implement the use of OMT in emergency medicine and urgent care settings. DISCUSSION: OMT can be used for a wide variety of acute and chronic pain conditions, particularly back pain, headaches, neck pain, and extremity pain (assuming that life-threatening conditions have been excluded). There are small studies and case series demonstrating both efficacy and subjective improvement with OMT, including in the ED. However, limitations to the current body of literature include: small numbers of patients, challenges with blinding and standardization, limited adverse event reporting, and most research has been outside of the ED setting. There is great opportunity for future studies and application of OMT in the ED. There are an increasing number of emergency clinicians incorporating OMT in their practice and despite the perception of OMT requiring extended periods of time to perform, current data suggests OMT does not prolong ED visits or cost to patients. OMT is a procedure with billing codes, and courses and training in OMT are available for both osteopathic and allopathic physicians. CONCLUSION: OMT is being used and has great potential in the management of acute and chronic musculoskeletal pain in the ED in addition to, or instead of pharmacologic agents, in particular as an opioid-sparing option.

5.
Crit Rev Clin Lab Sci ; 59(4): 241-256, 2022 06.
Article in English | MEDLINE | ID: mdl-34962443

ABSTRACT

Given that von Willebrand disease (VWD) is one of the most common bleeding disorders, the diagnosis or the exclusion is essential in the workup of individuals that have unexplained bleeding. For the clinical laboratory, the challenge is highlighted by the variable presentations of this disorder and the multiple assays that are available from different vendors. This review will give a brief overview of primary hemostasis with a detailed explanation of the biosynthesis, structure, and mechanics of von Willebrand factor (VWF). The final sections will focus on the distinguishing characteristics of the different types of VWD and the array of clinical laboratory tests currently available to assist in the diagnosis.


Subject(s)
von Willebrand Diseases , von Willebrand Factor , Hemostasis , Humans , von Willebrand Diseases/diagnosis
7.
Phys Rev Lett ; 129(17): 175501, 2022 Oct 21.
Article in English | MEDLINE | ID: mdl-36332263

ABSTRACT

Lacking the structural information of crystalline solids, the origin of the relaxation dynamics of metallic glasses is unclear. Here, we report the evolution of stress relaxation of high-entropy metallic glasses with distinct ß relaxation behavior. The fraction of liquidlike zones, determined at each temperature by the intensity of stress decay, is shown to be directly related to both the aging process and the spectrum of relaxation modes obtained by mechanical spectroscopy. The results shed light on the intrinsic correlation between the static and dynamic mechanical response in high-entropy and conventional metallic glasses, pointing toward a sluggish diffusion high-entropy effect in the liquid dynamics.

8.
BMC Med Res Methodol ; 22(1): 155, 2022 05 30.
Article in English | MEDLINE | ID: mdl-35637426

ABSTRACT

BACKGROUND: Natalizumab and fingolimod are used as high-efficacy treatments in relapsing-remitting multiple sclerosis. Several observational studies comparing these two drugs have shown variable results, using different methods to control treatment indication bias and manage censoring. The objective of this empirical study was to elucidate the impact of methods of causal inference on the results of comparative effectiveness studies. METHODS: Data from three observational multiple sclerosis registries (MSBase, the Danish MS Registry and French OFSEP registry) were combined. Four clinical outcomes were studied. Propensity scores were used to match or weigh the compared groups, allowing for estimating average treatment effect for treated or average treatment effect for the entire population. Analyses were conducted both in intention-to-treat and per-protocol frameworks. The impact of the positivity assumption was also assessed. RESULTS: Overall, 5,148 relapsing-remitting multiple sclerosis patients were included. In this well-powered sample, the 95% confidence intervals of the estimates overlapped widely. Propensity scores weighting and propensity scores matching procedures led to consistent results. Some differences were observed between average treatment effect for the entire population and average treatment effect for treated estimates. Intention-to-treat analyses were more conservative than per-protocol analyses. The most pronounced irregularities in outcomes and propensity scores were introduced by violation of the positivity assumption. CONCLUSIONS: This applied study elucidates the influence of methodological decisions on the results of comparative effectiveness studies of treatments for multiple sclerosis. According to our results, there are no material differences between conclusions obtained with propensity scores matching or propensity scores weighting given that a study is sufficiently powered, models are correctly specified and positivity assumption is fulfilled.


Subject(s)
Multiple Sclerosis, Relapsing-Remitting , Multiple Sclerosis , Fingolimod Hydrochloride/therapeutic use , Humans , Multiple Sclerosis/drug therapy , Multiple Sclerosis, Relapsing-Remitting/drug therapy , Natalizumab/therapeutic use , Treatment Outcome
9.
Osteoarthritis Cartilage ; 29(11): 1487-1497, 2021 11.
Article in English | MEDLINE | ID: mdl-34348184

ABSTRACT

OBJECTIVE: To examine if relationships between knee osteoarthritis (OA) progression with knee moments and muscle activation during gait vary between patients with non-traumatic and post-traumatic knee OA. DESIGN: This longitudinal study included participants with non-traumatic (n = 17) and post-traumatic (n = 18) knee OA; the latter group had a previous anterior cruciate ligament rupture. Motion capture cameras, force plates, and surface electromyography measured knee moments and lower extremity muscle activation during gait. Cartilage volume change were determined over 2 years using magnetic resonance imaging in four regions: medial and lateral plateau and condyle. Linear regression analysis examined relationships between cartilage change with gait metrics (moments, muscle activation), group, and their interaction. RESULTS: Measures from knee adduction and rotation moments were related to lateral condyle cartilage loss in both groups, and knee adduction moment to lateral plateau cartilage loss in the non-traumatic group only [ß = -1.336, 95% confidence intervals (CI) = -2.653 to -0.019]. Generally, lower levels of stance phase muscle activation were related to greater cartilage loss. The relationship between cartilage loss in some regions with muscle activation characteristics varied between non-traumatic and post-traumatic groups including for: lateral hamstring (lateral condyle ß = 0.128, 95%CI = 0.003 to 0.253; medial plateau ß = 0.199, 95%CI = 0.059 to 0.339), rectus femoris (medial condyle ß = -0.267, 95%CI = -0.460 to -0.073), and medial hamstrings (medial plateau; ß = -0.146, 95%CI = -0.244 to -0.048). CONCLUSION: Findings indicate that gait risk factors for OA progression may vary between patients with non-traumatic and post-traumatic knee OA. These OA subtypes should be considered in studies that investigate gait metrics as risk factors for OA progression.


Subject(s)
Cartilage, Articular/diagnostic imaging , Gait/physiology , Muscle, Skeletal/physiology , Osteoarthritis, Knee/physiopathology , Anterior Cruciate Ligament Injuries/physiopathology , Cohort Studies , Disease Progression , Electromyography , Female , Humans , Knee Joint/diagnostic imaging , Longitudinal Studies , Magnetic Resonance Imaging , Male , Middle Aged , Osteoarthritis, Knee/diagnostic imaging , Risk Factors
10.
BMC Health Serv Res ; 21(1): 10, 2021 Jan 04.
Article in English | MEDLINE | ID: mdl-33397386

ABSTRACT

BACKGROUND: Quebec is one of the Canadian provinces with the highest rates of cancer incidence and prevalence. A study by the Rossy Cancer Network (RCN) of McGill university assessed six aspects of the patient experience among cancer patients and found that emotional support is the aspect most lacking. To improve this support, trained patient advisors (PAs) can be included as full-fledged members of the healthcare team, given that PA can rely on their knowledge with experiencing the disease and from using health and social care services to accompany cancer patients, they could help to round out the health and social care services offer in oncology. However, the feasibility of integrating PAs in clinical oncology teams has not been studied. In this multisite study, we will explore how to integrate PAs in clinical oncology teams and, under what conditions this can be successfully done. We aim to better understand effects of this PA intervention on patients, on the PAs themselves, the health and social care team, the administrators, and on the organization of services and to identify associated ethical and legal issues. METHODS/DESIGN: We will conduct six mixed methods longitudinal case studies. Qualitative data will be used to study the integration of the PAs into clinical oncology teams and to identify the factors that are facilitators and inhibitors of the process, the associated ethical and legal issues, and the challenges that the PAs experience. Quantitative data will be used to assess effects on patients, PAs and team members, if any, of the PA intervention. The results will be used to support oncology programs in the integration of PAs into their healthcare teams and to design a future randomized pragmatic trial to evaluate the impact of PAs as full-fledged members of clinical oncology teams on cancer patients' experience of emotional support throughout their care trajectory. DISCUSSION: This study will be the first to integrate PAs as full-fledged members of the clinical oncology team and to assess possible clinical and organizational level effects. Given the unique role of PAs, this study will complement the body of research on peer support and patient navigation. An additional innovative aspect of this study will be consideration of the ethical and legal issues at stake and how to address them in the health care organizations.


Subject(s)
Medical Oncology , Patient Care Team , Canada , Humans , Patient Outcome Assessment , Quebec/epidemiology
11.
Aging Clin Exp Res ; 32(4): 547-560, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32170710

ABSTRACT

Osteoarthritis (OA) is the most common joint condition and, with a burgeoning ageing population, is due to increase in prevalence. Beyond conventional medical and surgical interventions, there are an increasing number of 'alternative' therapies. These alternative therapies may have a limited evidence base and, for this reason, are often only afforded brief reference (or completely excluded) from current OA guidelines. Thus, the aim of this review was to synthesize the current evidence regarding autologous chondrocyte implantation (ACI), mesenchymal stem cell (MSC) therapy, platelet-rich plasma (PRP), vitamin D and other alternative therapies. The majority of studies were in knee OA or chondral defects. Matrix-assisted ACI has demonstrated exceedingly limited, symptomatic improvements in the treatment of cartilage defects of the knee and is not supported for the treatment of knee OA. There is some evidence to suggest symptomatic improvement with MSC injection in knee OA, with the suggestion of minimal structural improvement demonstrated on MRI and there are positive signals that PRP may also lead to symptomatic improvement, though variation in preparation makes inter-study comparison difficult. There is variability in findings with vitamin D supplementation in OA, and the only recommendation which can be made, at this time, is for replacement when vitamin D is deplete. Other alternative therapies reviewed have some evidence (though from small, poor-quality studies) to support improvement in symptoms and again there is often a wide variation in dosage and regimens. For all these therapeutic modalities, although controlled studies have been undertaken to evaluate effectiveness in OA, these have often been of small size, limited statistical power, uncertain blindness and using various methodologies. These deficiencies must leave the question as to whether they have been validated as effective therapies in OA (or chondral defects). The conclusions of this review are that all alternative interventions definitely require clinical trials with robust methodology, to assess their efficacy and safety in the treatment of OA beyond contextual and placebo effects.


Subject(s)
Complementary Therapies/methods , Osteoarthritis, Knee/therapy , Age Factors , Chondrocytes/transplantation , Female , Humans , Male , Mesenchymal Stem Cell Transplantation/methods , Transplantation, Autologous/methods , Treatment Outcome , Vitamin D/therapeutic use , Vitamins/therapeutic use
12.
Osteoarthritis Cartilage ; 27(4): 630-637, 2019 04.
Article in English | MEDLINE | ID: mdl-30654119

ABSTRACT

OBJECTIVE: To compare cartilage thickness between patients with non-traumatic and post-traumatic knee osteoarthritis (OA) and healthy controls and to determine if disease severity and alignment impact these differences. DESIGN: Participants with non-traumatic (n = 22) and post-traumatic (n = 19) knee OA, and healthy controls (n = 22) were recruited for this cross-sectional study. Participants underwent 3T magnetic resonance imaging (T1-weighted, 3D sagittal gradient echo sequence) and cartilage thickness was determined in four regions: medial and lateral condyle, and medial and lateral plateau. Lower extremity alignment (mechanical axis angle) and disease severity (Kellgren-Lawrence scores) were measured from full length radiographs. Statistical analysis included one-way analysis of variance (ANOVA) and modified Bonferroni test adjusting for multiple pairwise comparisons. Linear regression analyses examined the relationship between cartilage thickness and knee OA group after controlling for disease severity, meniscal status, and alignment. RESULTS: In participants with predominantly medial compartment knee OA, compared to healthy controls, those with non-traumatic knee OA had diminished cartilage thickness in the medial plateau (p = 0.035) and those with post-traumatic knee OA had greater cartilage thickness in the lateral condyle (p = 0.044). In the lateral condyle, data revealed that alignment accounted for the variance in cartilage thickness (p = 0.035), in which a stronger relationship was found in the non-traumatic (r = -0.61) than the post-traumatic (r = -0.12) OA group. CONCLUSIONS: Emerging data demonstrated that participants with non-traumatic knee OA have a stronger relationship between alignment and cartilage thickness than those with post-traumatic knee OA. This indicates that factors involved in knee OA initiation and progression may differ between these OA subtypes.


Subject(s)
Cartilage, Articular/pathology , Knee Injuries/complications , Knee Joint/pathology , Magnetic Resonance Imaging/methods , Osteoarthritis, Knee/diagnosis , Adult , Aged , Cross-Sectional Studies , Disease Progression , Female , Femur/pathology , Follow-Up Studies , Humans , Male , Middle Aged , Osteoarthritis, Knee/etiology , Retrospective Studies , Tibia/pathology
13.
Osteoarthritis Cartilage ; 27(8): 1163-1173, 2019 08.
Article in English | MEDLINE | ID: mdl-31102776

ABSTRACT

OBJECTIVE: There is a need to identify reliable biomarkers that can predict knee osteoarthritis (OA) progression. We investigated a panel of adipokines and some related inflammatory factors alone and their ratios for their associative value at assessing cartilage volume loss over time and symptoms in obese [High body mass index (BMI)] and non-obese (Low BMI) OA subjects. DESIGN: Human OA serum was from the Osteoarthritis Initiative Progression subcohort. Baseline levels of adiponectin (high and low molecular weight forms), adipsin, chemerin, leptin, visfatin, C-reactive protein (CRP), interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) were evaluated with specific assays. Cartilage volume was assessed at baseline and 48 months by quantitative magnetic resonance imaging (MRI), and symptoms using baseline Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores. Data were analysed by linear regression with confounding factors at baseline, followed by multiple comparison adjustment. RESULTS: The levels of the nine biomarkers and their ratios (36) were studied. Among High BMI subjects, only the ratio adipsin/MCP-1 was associated with cartilage volume loss over time in the lateral compartment [ß, -2.95; 95% confidence interval (CI), -4.42, -1.49; P = 0.010], whereas MCP-1 was associated with WOMAC pain (-1.74; -2.75, -0.73; P = 0.030) and the ratio CRP/MCP-1 with WOMAC pain (0.76; 0.37, 1.14; P = 0.023), function (2.43; 1.20, 3.67; P = 0.020) and total (3.29; 1.58, 5.00; P = 0.027). No associations were found for biomarkers or ratios in Low BMI OA. CONCLUSION: In this study, the ratio adipsin/MCP-1 was found to be associated with the knee structural changes and that of CRP/MCP-1 with symptoms in obese OA subjects. Our data further underline the relevance of ratios as biomarkers to a stronger association to OA progression and symptoms.


Subject(s)
C-Reactive Protein/analysis , Cartilage, Articular/diagnostic imaging , Chemokine CCL2/blood , Complement Factor D/analysis , Disease Progression , Osteoarthritis, Knee/diagnostic imaging , Biomarkers/blood , Body Mass Index , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Obesity/epidemiology , Osteoarthritis, Knee/epidemiology , Pain Measurement
14.
Transfusion ; 59(6): 1907-1910, 2019 06.
Article in English | MEDLINE | ID: mdl-30768787

ABSTRACT

BACKGROUND: Delayed hemolytic transfusion reaction (DHTR) with hyperhemolysis is a potentially fatal complication resulting from alloimmunization that can cause severe hemolysis of both transfused and intrinsic red blood cells (RBCs). Patients with sickle cell disease often receive multiple RBC units during their lifetime and thus are likely to develop alloantibodies that increase the risk for DHTR. Treatment to decrease hemolysis includes intravenous immunoglobulin (IVIG), steroids, eculizumab, rituximab, and plasmapheresis in addition to erythropoietin (EPO), intravenous (IV) iron, vitamin B12, and folate to support erythropoiesis. RBC transfusion is preferably avoided in DHTR due to an increased risk of exacerbating the hemolysis. CASE REPORT: We report a rare case of anti-N and anti-Doa immunoglobulin (Ig)G alloantibody-mediated life-threatening DHTR with hyperhemolysis in a patient with hemoglobin SS after RBC transfusion for acute chest syndrome who was successfully treated with eculizumab and HBOC-201 (Hemopure) in addition to steroids, IVIG, EPO, IV iron, and vitamin B12. HBOC-201 (Hemopure) was successfully used as a RBC alternative in this patient. CONCLUSION: Anti-N and anti-Doa IgG alloantibodies can rarely cause severe life-threatening DHTR with hyperhemolysis. HBOC-201 (Hemopure) can be a lifesaving alternative in this scenario. Our report also supports the use of eculizumab in DHTR; however, prospective studies are needed to determine the appropriate dose and sequence of eculizumab administration.


Subject(s)
Anemia, Sickle Cell/therapy , Antibodies, Monoclonal, Humanized/administration & dosage , Hemoglobins/administration & dosage , Hemolysis/immunology , Immunoglobulin G/blood , Isoantibodies/blood , Transfusion Reaction/etiology , Adult , Anemia, Hemolytic, Autoimmune/blood , Anemia, Hemolytic, Autoimmune/etiology , Anemia, Hemolytic, Autoimmune/immunology , Anemia, Sickle Cell/blood , Anemia, Sickle Cell/immunology , Antibodies, Monoclonal, Humanized/adverse effects , Antibodies, Monoclonal, Humanized/immunology , Female , Hemoglobins/adverse effects , Hemoglobins/immunology , Humans , Immunoglobulin G/physiology , Isoantibodies/physiology , Time Factors , Transfusion Reaction/blood , Transfusion Reaction/immunology
15.
Rev Neurol (Paris) ; 174(6): 429-440, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29779849

ABSTRACT

In 1993, the US Food and Drug Administration (FDA) approved the first drug specifically for treating multiple sclerosis (MS). More than two decades later, a dozen such treatments are now available. Of these, four are considered second-line treatments for use in escalation strategies and two new drugs are currently undergoing accreditation procedures. Soon, they will provide clinicians with a range of six effective disease-modifying treatments (DMTs) to thwart the inflammatory processes in MS patients with active disease. However, while such a large number of DMTs for MS can help to control early inflammation, any decisions to be made by clinicians have also been made substantially more complex. This complexity is increased by the lack of head-to-head studies comparing these second-line therapies and the benefit-risk profiles for each of these drugs, which are likely to vary among patients. Ultimately, good awareness of the benefits and, more important, the risks of each MS DMT is crucial for the effective management of inflammation in MS.


Subject(s)
Anti-Inflammatory Agents/administration & dosage , Immunosuppressive Agents/administration & dosage , Multiple Sclerosis/drug therapy , Neurology/trends , Anti-Inflammatory Agents/adverse effects , Drug Administration Schedule , Humans , Immunosuppressive Agents/adverse effects , Neurology/methods , Treatment Outcome , United States
16.
Osteoarthritis Cartilage ; 25(7): 1076-1083, 2017 07.
Article in English | MEDLINE | ID: mdl-28216311

ABSTRACT

OBJECTIVE: Whether meniscal extrusion and bone marrow lesions (BMLs) are independently associated with the risk of knee osteoarthritis (OA) is unknown. METHODS: Data was extracted from the Osteoarthritis Initiative (OAI) cohort. Participants were grouped according to the absence (Kellgren-Lawrence (KL) grade ≤ 1, n = 2120) or presence (KL ≥ 2, n = 2249) of radiographic OA (ROA). Baseline meniscal extrusion and tibial BMLs were assessed. Tibial plateau cartilage volume was assessed at baseline and 72 months, while radiographic disease was assessed at baseline and 48 months. Total knee replacement (TKR) was assessed at 72 months. RESULTS: In those with ROA, the presence of a baseline meniscal extrusion (independent of BMLs) was associated with accelerated cartilage volume loss (medial tibia: -2.1%/annum vs -1.5%; lateral: -2.6%/annum vs -1.6%; both P < 0.001), progressive ROA and TKR (Odds ratio (OR) range 1.4-1.8; 95% CI range 1.1-2.9). The presence of a baseline BML was associated with accelerated cartilage volume loss (medial tibia: -2.1%/annum vs -1.6%; lateral: -1.9%/annum vs -1.6%; P ≤ 0.02), progressive ROA and joint replacement (OR range 1.5-2.4; 95% CI range 1.1-3.4). In those with no ROA, a baseline medial meniscal extrusion was associated with accelerated cartilage volume loss (medial tibia: -2.1%/annum vs -1.2%, P < 0.001), and a baseline medial BML with incident ROA (OR 1.7, 95% CI 1.1 to 2.9). CONCLUSIONS: The presence of baseline meniscal extrusion and BMLs are associated with incident and progressive knee of each other (OA) and represent important structural targets for the treatment and prevention of knee OA.


Subject(s)
Bone Marrow Diseases/complications , Menisci, Tibial/pathology , Osteoarthritis, Knee/etiology , Aged , Arthroplasty, Replacement, Knee , Bone Marrow Diseases/pathology , Bone Marrow Diseases/physiopathology , Cartilage Diseases/pathology , Cartilage Diseases/physiopathology , Cartilage, Articular/pathology , Cartilage, Articular/physiology , Disease Progression , Female , Humans , Longitudinal Studies , Magnetic Resonance Imaging , Male , Middle Aged , Osteoarthritis, Knee/pathology , Osteoarthritis, Knee/physiopathology , Range of Motion, Articular/physiology , Risk Assessment
17.
Osteoarthritis Cartilage ; 25(10): 1719-1728, 2017 10.
Article in English | MEDLINE | ID: mdl-28694081

ABSTRACT

OBJECTIVE: 12/15-Lipoxygenase (12/15-LOX) catalyzes the generation of various anti-inflammatory lipid mediators, and has been implicated in several inflammatory and degenerative diseases. However, there is currently no evidence that 12/15-LOX has a role in osteoarthritis (OA). The aim of this study was to investigate the role of 12/15-LOX in the pathogenesis of OA. METHODS: The development of aging-associated and destabilization of the medial meniscus (DMM)-induced OA were compared in 12/15-LOX-deficient (12/15-LOX-/-) and wild-type (WT) mice. The extent of cartilage damage was evaluated by histology. The expression of OA markers was evaluated by immunohistochemistry and RT-PCR. Cartilage explants were stimulated with IL-1α in the absence or presence of the 12/15-LOX metabolites, 15-hydroxyeicosatetraenoic acids (15-HETE), 13-hydroxyoctadecadienoic acid (13-HODE) or lipoxin A4 (LXA4), and the levels of matrix metalloproteinases-13 (MMP-13), Nitric oxide (NO) and prostaglandin E2 (PGE2) were determined. The effect of LXA4 on the progression of OA was evaluated in wild type (WT) mice. RESULTS: The expression of 12/15-LOX in cartilage increased during the progression of DMM-induced OA and with aging in WT mice. Cartilage degeneration was more severe in 12/15-LOX-/- mice compared to WT mice in both models of OA, and this was associated with increased expression of MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs, aggrecanases (ADAMTS5), inducible NO synthases (iNOS), and mPGES-1. Treatment of cartilage explants with 12/15-LOX metabolites, suppressed IL-1α-induced production of MMP-13, NO and PGE2, with LXA4 being the most potent. Intra-peritoneal injection of LXA4 reduced the severity of DMM-induced cartilage degradation. CONCLUSIONS: These data suggest an important role of 12/15-LOX in the pathogenesis of OA. They also suggest that activation of this pathway may provide a novel strategy for prevention and treatment of OA.


Subject(s)
Arachidonate 12-Lipoxygenase/physiology , Arachidonate 15-Lipoxygenase/physiology , Arthritis, Experimental/enzymology , Osteoarthritis/enzymology , Aging/metabolism , Aging/pathology , Animals , Arachidonate 12-Lipoxygenase/deficiency , Arachidonate 12-Lipoxygenase/genetics , Arachidonate 15-Lipoxygenase/deficiency , Arachidonate 15-Lipoxygenase/genetics , Arthritis, Experimental/etiology , Arthritis, Experimental/prevention & control , Cartilage, Articular/metabolism , Disease Progression , Inflammation Mediators/metabolism , Joint Instability/complications , Lipoxins/therapeutic use , Male , Mice, Knockout , Osteoarthritis/etiology , Osteoarthritis/prevention & control , Tibial Meniscus Injuries/complications , Tissue Culture Techniques , Up-Regulation
18.
Protein Expr Purif ; 131: 60-69, 2017 03.
Article in English | MEDLINE | ID: mdl-27856402

ABSTRACT

Visceral Leishmaniasis (VL) represents an important global health problem in several warm countries around the world. The main targets in this study are the two nucleoside triphosphate diphosphohydrolases (NTPDases) from Leishmania infantum chagasi that are the main etiologic agent of VL in the New World. These enzymes, called LicNTPDase1 and -2, are homologous to members 5 and 6 of the mammalian E-NTPDase/CD39 superfamily of enzymes. These enzymes hydrolyze nucleotides and accordingly can participate in the purine salvage pathways and in the modulation of purinergic signaling through the extracellular nucleotide-dependent host immune responses. They can therefore affect adhesion and infection of host cells and the parasite virulence. To further characterize these enzymes, in this work, we expressed LicNTPDase1 and -2 in the classical bacterial system Escherichia coli and mammalian cell system COS-7 cells. Our data demonstrate that changes in refolding after expression in bacteria can increase the activity of recombinant (r) rLicNTPDase2 up to 20 times but has no significant effect on rLicNTPDase1. Meanwhile, the expression in COS-7 led to a significant increase in activity for rLicNTPDase1.


Subject(s)
Adenosine Triphosphatases , Antigens, CD , Apyrase , Gene Expression , Leishmania infantum/genetics , Protein Refolding , Protozoan Proteins , Adenosine Triphosphatases/biosynthesis , Adenosine Triphosphatases/chemistry , Adenosine Triphosphatases/genetics , Adenosine Triphosphatases/isolation & purification , Animals , Antigens, CD/biosynthesis , Antigens, CD/chemistry , Antigens, CD/genetics , Antigens, CD/isolation & purification , Apyrase/biosynthesis , Apyrase/chemistry , Apyrase/genetics , Apyrase/isolation & purification , COS Cells , Chlorocebus aethiops , Escherichia coli , Leishmania infantum/enzymology , Protozoan Proteins/biosynthesis , Protozoan Proteins/chemistry , Protozoan Proteins/genetics , Protozoan Proteins/isolation & purification , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/isolation & purification
19.
BMC Musculoskelet Disord ; 18(1): 445, 2017 Nov 14.
Article in English | MEDLINE | ID: mdl-29137611

ABSTRACT

BACKGROUND: Emergence of more autonomous roles for physiotherapists warrants more evidence regarding their diagnostic capabilities. Therefore, we aimed to evaluate diagnostic and surgical triage concordance between a physiotherapist and expert physicians and to assess the diagnostic validity of the physiotherapist's musculoskeletal examination (ME) without imaging. METHODS: This is a prospective diagnostic study where 179 consecutive participants consulting for any knee complaint were independently diagnosed and triaged by two evaluators: a physiotherapist and one expert physician (orthopaedic surgeons or sport medicine physicians). The physiotherapist completed only a ME, while the physicians also had access to imaging to make their diagnosis. Raw agreement proportions and Cohen's kappa (k) were calculated to assess inter-rater agreement. Sensitivity (Se) and specificity (Sp), as well as positive and negative likelihood ratios (LR+/-) were calculated to assess the validity of the ME compared to the physicians' composite diagnosis. RESULTS: Primary knee diagnoses included anterior cruciate ligament injury (n = 8), meniscal injury (n = 36), patellofemoral pain (n = 45) and osteoarthritis (n = 79). Diagnostic inter-rater agreement between the physiotherapist and physicians was high (k = 0.89; 95% CI:0.83-0.94). Inter-rater agreement for triage recommendations of surgical candidates was good (k = 0.73; 95% CI:0.60-0.86). Se and Sp of the physiotherapist's ME ranged from 82.0 to 100.0% and 96.0 to 100.0% respectively and LR+/- ranged from 23.2 to 30.5 and from 0.03 to 0.09 respectively. CONCLUSIONS: There was high diagnostic agreement and good triage concordance between the physiotherapist and physicians. The ME without imaging may be sufficient to diagnose or exclude common knee disorders for a large proportion of patients. Replication in a larger study will be required as well as further assessment of innovative multidisciplinary care trajectories to improve care of patients with common musculoskeletal disorders.


Subject(s)
Knee Injuries/diagnosis , Knee Joint , Osteoarthritis, Knee/diagnosis , Physical Therapists/statistics & numerical data , Adult , Aged , Female , Humans , Male , Middle Aged , Physical Examination/statistics & numerical data , Prospective Studies , Triage
20.
Analyst ; 141(2): 697-703, 2016 Jan 21.
Article in English | MEDLINE | ID: mdl-26229988

ABSTRACT

Sensing of methotrexate at clinically-relevant concentrations was achieved with a plasmon-coupling assay. In this assay, free methotrexate and folic acid Au nanoparticles competed for human dihydrofolate reductase (hDHFR)-functionalized Au nanoparticles (Au NP). The hDHFR-functionalized Au NPs were immobilized on a small glass sensor inserted in a portable 4-channel LSPR reader. This allowed rapid (minutes) and sensitive (nanomolar range) measurement of methotrexate concentration by means of total internal reflection plasmonic spectroscopy. The large bathochromic shifts of the plasmon-coupling assay led to striking colour changes visible to the naked eye for methotrexate at clinically-relevant concentrations. The results demonstrate the potential for therapeutic drug monitoring of a widely used chemotherapy agent, as assessed with the naked eye.


Subject(s)
Drug Monitoring/methods , Methotrexate/analysis , Nanotechnology/methods , Surface Plasmon Resonance/methods , Colorimetry , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/metabolism , Gold/chemistry , Humans , Metal Nanoparticles/chemistry , Methotrexate/pharmacology , Models, Molecular , Particle Size , Protein Conformation , Tetrahydrofolate Dehydrogenase/chemistry , Tetrahydrofolate Dehydrogenase/metabolism
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