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1.
Molecules ; 24(12)2019 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-31208115

RESUMO

In this paper, we explain the amphoteric character of the cartilage surface by studying a lipid bilayer model built from phospholipids. We examined the interfacial tension values and molecular dynamics simulation in solutions of varying pH. The effects of negative and positive charge density (or fixed charges) on the (cartilage/cartilage) friction coefficient were investigated. In physiological (or synovial) fluid, after the isoelectric point (pI), the curve of interfacial tension decreases rapidly as it reaches pH 7.4 and then approaches a constant value at higher pH. It was shown that the curve of the interfacial tension curve exhibits a maximum value at the isoelectric point with a Gaussian shape feature. The phospholipid bilayers facilitate an almost frictionless contact in the joint. Moreover, the slippage of the bilayer and the short-range repulsion between the surfaces of the negatively charged cartilage surfaces are the main determinants of the low frictional properties of the joint.


Assuntos
Cartilagem Articular/química , Articulações/química , Articulação do Joelho/química , Bicamadas Lipídicas/química , Animais , Cartilagem Articular/metabolismo , Cartilagem Articular/fisiologia , Fricção/fisiologia , Interações Hidrofóbicas e Hidrofílicas , Articulações/fisiologia , Mamíferos/fisiologia , Simulação de Dinâmica Molecular , Fosfolipídeos/química , Tensão Superficial , Líquido Sinovial/química , Molhabilidade
2.
Clin Exp Rheumatol ; 36(6): 1061-1067, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30418110

RESUMO

OBJECTIVES: To validate the diagnostic benefit of dual-energy computed tomography (DECT) and synovial fluid aspiration in suspected gout. METHODS: A total of 43 patients with suspected gout underwent aspiration and DECT (320-row CT; Canon Medical Systems, Japan). The patients were assessed (gout vs. non-gout) based on the 2015 ACR/EULAR gout classification criteria using clinical and laboratory findings. The results were analysed by comparing two scenarios using McNemar test: Scenario A: ACR/EULAR criteria, followed by DECT results and aspiration findings. Scenario B: ACR/EULAR criteria, followed by aspiration and DECT results. RESULTS: 15/43 patients (34.9%) were positive for MSU crystals, and 16/43 patients (37.2%) for gouty tophi (DECT). 26/43 patients (60.5%) were diagnosed with gout and fulfilled the ACR/EULAR criteria. The diagnostic performance of either synovial fluid aspiration or DECT was similar with sensitivity of 58% and specificity of 100% and 94%, respectively. Combination of both modalities (at least one of them positive), resulted in increased sensitivity of 85% and unchanged specificity (94%). Based only on clinical and laboratory findings, 13/43 patients (30.2%) were classified as gout according to ACR/EULAR criteria. In scenario A, additional 8 out of 30 (26.7%) patients were diagnosed as gout by DECT findings, and another 5/22 (22.7%) patients by aspiration findings. In scenario B, initial consideration of aspiration findings resulted in 10 out of 30 (33.3%) additionally identified patients, and another 3 (15%) patients by DECT findings. There was no relevant difference between scenarios A and B (p=0.508). CONCLUSIONS: Combination of joint aspiration and DECT improves the diagnostic algorithm for gout. In our attempt to establish an optimal sequence of diagnostic tests, we did not identify an advantage for either synovial fluid analysis or DECT as the initially better modality after clinical examination and analysis of blood tests.


Assuntos
Artrite Gotosa/diagnóstico por imagem , Artrite Gotosa/metabolismo , Articulações/química , Articulações/diagnóstico por imagem , Tomografia Computadorizada Multidetectores , Líquido Sinovial/química , Ácido Úrico/análise , Adulto , Idoso , Cristalização , Feminino , Humanos , Masculino , Microscopia de Polarização , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Reprodutibilidade dos Testes , Sucção
3.
Curr Rheumatol Rep ; 20(3): 13, 2018 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-29516278

RESUMO

PURPOSE OF REVIEW: Osteoarthritis (OA) is the most common form of joint disease globally and is associated with significant morbidity and disability. Increasing evidence points to an important inflammatory component in the development and progression of OA. The precise pathways involved in OA inflammatory processes remain to be clarified. Basic calcium phosphate (BCP) and calcium pyrophosphate dihydrate (CPP) crystals can induce inflammation and arthritis and recent studies point to a potential pathogenic role in OA. In the light of this evidence, we explore the relationship and potential mechanistic pathways linking calcium-containing crystals and OA. RECENT FINDINGS: CPP crystals induce inflammation through the NLRP3 inflammasome while BCP crystals mediate both NLRP3 dependent and independent effects. BCP crystals have been demonstrated to induce key mitogenic and inflammatory pathways and contribute to cartilage degradation. Calcium-containing crystals induce key inflammatory pathways and may represent an attractive novel target in OA, a condition devoid of effective treatments.


Assuntos
Fosfatos de Cálcio/análise , Osteoartrite/metabolismo , Pirofosfato de Cálcio/análise , Cristalização , Humanos , Articulações/química , Líquido Sinovial/química
4.
Annu Rev Biomed Eng ; 18: 235-58, 2016 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-27420572

RESUMO

The major synovial joints such as hips and knees are uniquely efficient tribological systems, able to articulate over a wide range of shear rates with a friction coefficient between the sliding cartilage surfaces as low as 0.001 up to pressures of more than 100 atm. No human-made material can match this. The means by which such surfaces maintain their very low friction has been intensively studied for decades and has been attributed to fluid-film and boundary lubrication. Here, we focus especially on the latter: the reduction of friction by molecular layers at the sliding cartilage surfaces. In particular, we discuss such lubrication in the light of very recent advances in our understanding of boundary effects in aqueous media based on the paradigms of hydration lubrication and of the synergism between different molecular components of the synovial joints (namely hyaluronan, lubricin, and phospholipids) in enabling this lubrication.


Assuntos
Cartilagem Articular/química , Cartilagem Articular/fisiologia , Articulações/química , Lubrificação , Modelos Biológicos , Reologia/métodos , Líquido Sinovial/química , Animais , Fricção , Humanos , Articulações/fisiologia , Modelos Químicos , Líquido Sinovial/fisiologia
5.
Orthopade ; 42(8): 622-8, 2013 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-23842780

RESUMO

Increased wear leads to elevated systemic and local metal ion concentrations for patients treated with metal-on-metal bearings. The local metal ion content in the close environment of the joint replacement (e.g. joint aspirate or tissue) is several times higher compared to the systemic metal content (e.g. in blood or serum). As a result of increased metal ion levels, local and systemic effects, such as osteolysis, pseudotumors, sensitization or in rare cases toxicity may occur. Although the definition of a specific threshold to define clinical problems is difficult due to a lack of sensitivity, the systemic metal concentration is frequently measured clinically. Currently a threshold for cobalt and chromium between 4 µg/l and 7 µg/l is under debate. Very high levels (≥ 20 µg/l) or a steady increase over time should be a warning sign; however, metal ion levels should not be interpreted as a single diagnostic tool but rather in the entire context of the clinical, radiological and cross-sectional imaging, metal artefact reduction sequence (MARS) magnetic resonance imaging (MRI), ultrasound and computed tomography (CT) findings.


Assuntos
Hipersensibilidade/etiologia , Hipersensibilidade/metabolismo , Articulações/química , Articulações/efeitos dos fármacos , Próteses Articulares Metal-Metal/efeitos adversos , Metais/efeitos adversos , Metais/química , Humanos , Íons/efeitos adversos , Íons/química , Tamanho da Partícula
6.
J Cell Biol ; 177(6): 1105-17, 2007 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-17576802

RESUMO

Despite its clinical significance, joint morphogenesis is still an obscure process. In this study, we determine the role of transforming growth factor beta (TGF-beta) signaling in mice lacking the TGF-beta type II receptor gene (Tgfbr2) in their limbs (Tgfbr2(PRX-1KO)). In Tgfbr2(PRX-1KO) mice, the loss of TGF-beta responsiveness resulted in the absence of interphalangeal joints. The Tgfbr2(Prx1KO) joint phenotype is similar to that in patients with symphalangism (SYM1-OMIM185800). By generating a Tgfbr2-green fluorescent protein-beta-GEO-bacterial artificial chromosome beta-galactosidase reporter transgenic mouse and by in situ hybridization and immunofluorescence, we determined that Tgfbr2 is highly and specifically expressed in developing joints. We demonstrated that in Tgfbr2(PRX-1KO) mice, the failure of joint interzone development resulted from an aberrant persistence of differentiated chondrocytes and failure of Jagged-1 expression. We found that TGF-beta receptor II signaling regulates Noggin, Wnt9a, and growth and differentiation factor-5 joint morphogenic gene expressions. In Tgfbr2(PRX-1KO) growth plates adjacent to interphalangeal joints, Indian hedgehog expression is increased, whereas Collagen 10 expression decreased. We propose a model for joint development in which TGF-beta signaling represents a means of entry to initiate the process.


Assuntos
Articulações/crescimento & desenvolvimento , Morfogênese , Transdução de Sinais , Fator de Crescimento Transformador beta/fisiologia , Animais , Embrião de Mamíferos , Extremidades , Articulações/química , Articulações/embriologia , Camundongos , Camundongos Knockout , Proteínas Serina-Treonina Quinases , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/análise , Receptores de Fatores de Crescimento Transformadores beta/deficiência
7.
Biomacromolecules ; 12(10): 3432-43, 2011 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-21823600

RESUMO

Mammalian synovial joints are extremely efficient lubrication systems reaching friction coefficient µ as low as 0.001 at high pressures (up to 100 atm) and shear rates (up to 10(6) to 10(7) Hz); however, despite much previous work, the exact mechanism responsible for this behavior is still unknown. In this work, we study the molecular mechanism of synovial joint lubrication by emulating the articular cartilage superficial zone structure. Macromolecules extracted and purified from bovine hip joints using well-known biochemical techniques and characterized with atomic force microscope (AFM) have been used to reconstruct a hyaluronan (HA)--aggrecan layer on the surface of molecularly smooth mica. Aggrecan forms, with the help of link protein, supramolecular complexes with the surface-attached HA similar to those at the cartilage/synovial fluid interface. Using a surface force balance (SFB), normal and shear interactions between a HA--aggrecan-coated mica surface and bare mica have been examined, focusing, in particular, on the frictional forces. In each stage, control studies have been performed to ensure careful monitoring of the macromolecular surface layers. We found the aggrecan--HA complex to be a much better boundary lubricant than the HA alone, an effect attributed largely to the fluid hydration sheath bound to the highly charged glycosaminoglycan (GAG) segments on the aggrecan core protein. A semiquantitative model of the osmotic pressure is used to describe the normal force profiles between the surfaces and interpret the boundary lubrication mechanism of such layers.


Assuntos
Agrecanas/química , Materiais Biocompatíveis/química , Cartilagem Articular/química , Ácido Hialurônico/química , Articulações/química , Engenharia Tecidual/métodos , Agrecanas/metabolismo , Silicatos de Alumínio/química , Animais , Materiais Biocompatíveis/metabolismo , Fenômenos Biomecânicos , Cartilagem Articular/metabolismo , Bovinos , Fricção , Humanos , Ácido Hialurônico/metabolismo , Articulações/metabolismo , Microscopia de Força Atômica , Pressão Osmótica , Propriedades de Superfície , Líquido Sinovial/química , Líquido Sinovial/metabolismo , Extratos de Tecidos/química , Extratos de Tecidos/metabolismo
8.
PLoS One ; 16(8): e0256177, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34432832

RESUMO

Osteoarthritis (OA) as the main degenerative disease of articular cartilage in joints is accompanied by structural and compositional changes in the tissue. Degeneration is a consequence of a reduction of the amount of macromolecules, the so-called proteoglycans, and of a corresponding increase in water content, both leading to structural weakening of cartilage. NMR investigations of cartilage generally address only the relaxation properties of water. In this study, two-dimensional (T1-T2) measurements of bovine articular cartilage samples were carried out for different stages of hydration, complemented by molecular exchange with D2O and treatment by trypsin which simulates degeneration by OA. Two signal components were identified in all measurements, characterized by very different T2 which suggests liquid-like and solid-like dynamics. These measurements allow the quantification of separate hydrogen components and their assignment to defined physical pools which had been discussed repeatedly in the literature, i.e. bulk-like water and a combination of protein hydrogens and strongly bound water. The first determination of 2H relaxation dispersion in comparison to 1H dispersion suggests intramolecular interactions as the dominating source for the pronounced magnetic field dependence of the longitudinal relaxation time T1.


Assuntos
Cartilagem Articular/química , Osteoartrite/diagnóstico , Proteoglicanas/química , Água/química , Animais , Bovinos , Humanos , Articulações/química , Espectroscopia de Ressonância Magnética , Simulação de Dinâmica Molecular , Osteoartrite/metabolismo , Osteoartrite/patologia , Proteoglicanas/isolamento & purificação
9.
Vet J ; 267: 105579, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33375964

RESUMO

Nerve growth factor (NGF) is a neurotrophin with many functions. In humans, it is involved in inflammation, nerve growth, apoptosis and pain signalling. Increased concentrations of NGF in synovial fluid has been shown in humans and dogs with osteoarthritis. Despite osteoarthritis being a common problem in horses, no studies have previously been published on NGF in the equine joint. The aim of this study was to quantify NGF in equine synovial fluid from healthy joints, acutely inflamed septic joints and joints with structural changes associated with osteoarthritis. A secondary aim was to identify the localisation of NGF and its two receptors, TrkA and p75NTR, in healthy and osteoarthritic articular cartilage. NGF concentrations in synovial fluid from osteoarthritic joints (n = 27), septic joints (n = 9) and healthy joints (n = 16) were determined by ELISA. In addition, articular cartilage from osteoarthritic and healthy joints was examined for NGF, TrkA and p75NTR using immunohistochemistry staining. NGF was present in equine synovial fluid and articular cartilage. Compared to synovial fluid from healthy joints, NGF concentration was higher in synovial fluid from joints with structural osteoarthritic changes (P = 0.032) or acute septic inflammation (P = 0.006). In articular cartilage with severe osteoarthritic changes, there was more abundant positive immunohistochemistry staining for NGF and its receptors than in normal articular cartilage. Further studies should focus on identifying precursor forms of NGF, and on receptor expression and downstream signalling of TrkA and P75NTR in health and disease.


Assuntos
Doenças dos Cavalos/metabolismo , Articulações/química , Animais , Artrite Infecciosa/metabolismo , Artrite Infecciosa/veterinária , Cartilagem Articular/química , Ensaio de Imunoadsorção Enzimática/veterinária , Cavalos , Imuno-Histoquímica/veterinária , Inflamação/metabolismo , Inflamação/veterinária , Coxeadura Animal/metabolismo , Fator de Crescimento Neural/análise , Osteoartrite/metabolismo , Osteoartrite/veterinária , Líquido Sinovial/química
10.
Am J Vet Res ; 80(4): 342-346, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30919681

RESUMO

OBJECTIVE: To determine whether differences existed in the viscoelastic properties of synovial fluid samples from the metacarpophalangeal, intercarpal, and distal interphalangeal joints of orthopedically normal athletic horses. ANIMALS: 45 warmblood horses and 30 Thoroughbreds (age range, 4 to 16 years). PROCEDURES: Synovial fluid samples were aseptically obtained via arthrocentesis from 1 metacarpophalangeal, intercarpal, and distal interphalangeal joint of each horse, and nucleated cell counts were performed. A commercial ELISA was used to measure sample hyaluronic acid concentrations, and full rheological characterization of samples was performed to measure the elastic or storage modulus G' and viscous or loss modulus G" at 37.5°C (representing the body temperature of horses). Findings were compared among joints and between breed groups by means of ANOVA. RESULTS: Significant differences in synovial fluid G' and G" values were identified between Thoroughbreds and warmblood horses for the metacarpophalangeal joint, between the metacarpophalangeal and intercarpal joints of Thoroughbreds, and between the metacarpophalangeal and distal interphalangeal joints and intercarpal and distal interphalangeal joints of warmblood horses. No significant differences were identified between breed groups or among joints in synovial fluid hyaluronic concentrations or nucleated cell counts. CONCLUSIONS AND CLINICAL RELEVANCE: Viscoelastic properties of the forelimb joints of orthopedically normal Thoroughbreds and warmblood horses differed within and between these 2 groups, mainly as a function of the evaluated joint. To the authors' knowledge, this was the first study of its kind, and additional research is warranted to better understand the viscoelastic properties of synovial fluid in horses to optimize their locomotive function.


Assuntos
Cavalos/fisiologia , Articulações/fisiologia , Animais , Elasticidade , Ensaio de Imunoadsorção Enzimática/veterinária , Membro Anterior , Ácido Hialurônico/análise , Articulações/química , Especificidade da Espécie , Líquido Sinovial/química , Líquido Sinovial/fisiologia , Substâncias Viscoelásticas , Viscosidade
11.
Arthritis Care Res (Hoboken) ; 70(12): 1814-1821, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29457379

RESUMO

OBJECTIVE: To assess potential associations among serum cytokines and microRNA (miR) levels with ultrasound (US) findings suggestive of urate deposits in chronic asymptomatic hyperuricemia and gout. METHODS: All participants underwent musculoskeletal US and measurements of serum interleukin-1ß (IL-1ß), IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-13, interferon-γ, tumor necrosis factor, monocyte chemoattractant protein 1, and epithelial neutrophil-activating peptide 78, as well as miR-146a, miR-155, and miR-223 levels. RESULTS: Thirty individuals with asymptomatic hyperuricemia, 31 normouricemic controls, and 30 patients with gout were included. The frequency of synovitis and double contour sign using US was similar between asymptomatic hyperuricemia (67% and 27%, respectively) and patients with gout (77% and 27%, respectively), and each had a higher frequency than controls (45% and 0%, respectively). Serum IL-6 and IL-8 levels were similar between patients with asymptomatic hyperuricemia (mean ± SD 69.7 ± 73.4 and 18.5 ± 25.6 pg/ml, respectively) and gout (mean ± SD 75.8 ± 47.6 and 24.4 ± 31.7 pg/ml, respectively), and higher than controls (mean ± SD 28.2 ± 17.6 and 7.4 ± 6.0 pg/ml, respectively). A similar distribution was observed for miR-155 levels in asymptomatic hyperuricemia, patients with gout, and controls (mean ± SD 0.22 ± 0.18, 0.20 ± 0.14, and 0.08 ± 0.04, respectively). Associations between morphostructural abnormalities suggestive of urate deposits (regardless of clinical diagnosis) and serum markers were assessed. Subjects with urate deposits had higher IL-6 (257.2 versus 47.0 pg/ml; P = 0.005), IL-8 (73.2 versus 12.0 pg/ml; P = 0.026), and miR-155 (0.21 versus 0.16; P = 0.015) levels than those without deposition findings. CONCLUSION: In individuals with chronic asymptomatic hyperuricemia, the presence of synovitis and double contour sign by US may represent a subclinical manifestation of monosodium urate crystal nucleation, capable of triggering inflammatory pathways (IL-6 and IL-8) and mechanisms of intercellular communication (miR-155), similar to what is observed in patients with gout.


Assuntos
MicroRNA Circulante/sangue , Citocinas/sangue , Gota/sangue , Gota/diagnóstico por imagem , Hiperuricemia/sangue , Hiperuricemia/diagnóstico por imagem , Articulações/diagnóstico por imagem , Ultrassonografia Doppler , Adulto , Idoso , Doenças Assintomáticas , Biomarcadores/sangue , Estudos de Casos e Controles , Doença Crônica , Estudos Transversais , Cristalização , Feminino , Gota/etiologia , Humanos , Hiperuricemia/complicações , Hiperuricemia/diagnóstico , Articulações/química , Masculino , México , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Sinovite/sangue , Sinovite/diagnóstico por imagem , Sinovite/etiologia , Ácido Úrico/análise
12.
J Immunol Methods ; 322(1-2): 137-42, 2007 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-17362980

RESUMO

This paper describes the evaluation and optimisation of boric acid antigen retrieval (AR) in rat joint tissue immunohistochemistry (IHC), with reference to two sample IHC targets, CD31 (PECAM-1) and Proliferating Cell Nuclear Antigen (PCNA). Sections of buffered formalin-fixed arthritic tibial/talus joints, decalcified with EDTA, EDTA/formalin or Surgipath(R) Decalcifier I(R), were subjected to one of a number of pre-treatments (none, 0.1% trypsin, 0.2 M acetic acid pH 7.0 or 0.2 M boric acid pH 7.0) and then immunostained for CD31 or PCNA. Of the pre-treatment AR regimens, boric acid gave the most consistent and specific immunostaining of both antigens in joints from the three different decalcification protocols. Satisfactory CD31 and PCNA staining was also achieved in EDTA decalcified joints with no pre-treatment. Likewise, PCNA could be demonstrated in Surgipath(R) decalcified tissue without pre-treatment, albeit at slightly lower staining intensity than achieved following boric acid. The remaining decalcification/pre-treatment conditions were unsatisfactory for IHC of the two antigens investigated because of lack of staining, non-specific staining or consistent loss of sections from the slides. Boric acid pre-treatment provides a valuable alternative low temperature AR method where conventional heat-mediated AR methods are normally required but cannot be used due to tissue type.


Assuntos
Antígenos/análise , Ácidos Bóricos/química , Imuno-Histoquímica/métodos , Articulações/química , Coloração e Rotulagem/métodos , Animais , Técnica de Descalcificação , Molécula-1 de Adesão Celular Endotelial a Plaquetas/análise , Antígeno Nuclear de Célula em Proliferação/análise , Ratos
13.
Acta Biomater ; 62: 284-292, 2017 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-28803215

RESUMO

This study investigates the structural properties of the hind leg femur-tibia joint in adult katydids (Orthoptera: Tettigoniidae), including its tribological and mechanical properties. It is of particular interest because the orthopteran (e.g., grasshoppers, crickets, and katydids) hind leg is highly specialized for jumping. We show that the katydid hind leg femur-tibia joint had unique surfaces and textures, with a friction coefficient (µ) at its coupling surface of 0.053±0.001. Importantly, the sheared surfaces at this joint showed no sign of wear or damage, even though it had undergone thousands of external shearing cycles. We attribute its resiliency to a synergistic interaction between the hierarchical surface texture/pattern on the femoral surfaces, a nanograded internal nanostructure of articulating joints, and the presence of lubricating lipids on the surface at the joint interface. The micro/nanopatterned surface of the katydid hind leg femur-tibia joint enables a reduction in the total contact area, and this significantly reduces the adhesive forces between the coupling surfaces. In our katydids, the femur and tibia joint surfaces had a maximum effective elastic modulus (Eeff) value of 2.6GPa and 3.9GPa, respectively. Presumably, the decreased adhesion through the reduction of van der Waals forces prevented adhesive wear, while the contact between the softer textured surface and harder smooth surface avoided abrasive wear. The results from our bioinspired study offer valuable insights that can inform the development of innovative coatings and lubrication systems that are both energy efficient and durable. STATEMENT OF SIGNIFICANCE: Relative to body length, insects can outjump most animals. They also accelerate their bodies at a much faster rate. Orthopterans (e.g., grasshoppers, crickets, and katydids) have hind legs that are specialized for jumping. Over an individual's lifetime, the hind leg joint endures repeated cycles of flexing and extending, including jumping, and its efficiency and durability easily surpass that of most mechanical devices. Although the efficient functioning of insect joints has long been recognized, the mechanism by which insect joints experience friction/adhesion/wear, and operate efficiently/reliably is still largely unknown. Our study on the structural, tribological, and mechanical properties of the orthopteran hind leg joints reveals the potential of katydid bioinspired research leading to more effective coatings and lubrication systems.


Assuntos
Proteínas de Insetos/química , Articulações/química , Lubrificantes/química , Nanoestruturas/química , Ortópteros/química , Animais , Proteínas de Insetos/metabolismo , Articulações/anatomia & histologia , Articulações/metabolismo , Lubrificantes/metabolismo , Ortópteros/anatomia & histologia , Ortópteros/metabolismo
14.
Int J Rheum Dis ; 19(12): 1337-1341, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27458073

RESUMO

AIM: The aim of this study is to evaluate the diagnostic yield of dual-energy computed tomography (DECT) in detection of uric acid accumulation in joints or periarticular structures in patients suspected of having gout, in their intercritical period. METHODS: Patients with a history of recurrent, short-lived mono- or oligo-arthralgia or arthritis, referred to the rheumatology clinic for diagnosis of their condition, were included in this retrospective evaluation. RESULTS: DECT confirmed the diagnosis of gout in 30 of 50 patients (60%). A positive DECT was present in 12 of 16 cases (75%) with serum uric acid > 8.5 mg/dL, compared to seven of 13 cases (54%) and two of five cases (40%) with levels of 6.1-8.5 mg/dL and ≤ 6 mg/dL, respectively. The diagnostic impact of screening hands and feet were highest (78% and 56%, respectively). Follow-up data were available for 24 of the 30 patients with urate deposits identified by DECT. Twenty-one were treated with urate-lowering agents, all responded with lowering of serum uric acid and cessation of flares. Follow-up data were available for 16 of the 20 patients with no urate deposits identified by DECT. Gout was diagnosed in two of them by synovial fluid examination during subsequent flares. Both positive and negative predictive values of DECT for diagnosing gout in this patient population were 87%. Following DECT, treatment regimen was modified to gout-specific therapy in 52% of the patients. DISCUSSION: The ability to make a definite diagnosis of gout by DECT imaging in a substantial number of asymptomatic patients in the intercritical period should help in treatment decision-making and improve patient adherence to long-term urate-lowering therapy.


Assuntos
Gota/diagnóstico por imagem , Articulações/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Doenças Assintomáticas , Biomarcadores/sangue , Feminino , Gota/tratamento farmacológico , Gota/metabolismo , Supressores da Gota/uso terapêutico , Humanos , Articulações/química , Articulações/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Interpretação de Imagem Radiográfica Assistida por Computador , Estudos Retrospectivos , Resultado do Tratamento , Ácido Úrico/sangue
15.
J Voice ; 30(5): 538-48, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26687542

RESUMO

OBJECTIVE: The present study aimed to clarify individual variations in the cricothyroid joint (CT joint). METHODS: Using 30 specimens of the CT joint obtained from elderly donated cadavers, we examined the composite fibers of the capsular ligament as well as the morphology of the synovial tissue. RESULTS: The capsular ligament consistently contained abundant thick elastic fiber bundles on the anterior side of the joint (anterior band) and an elastic fiber-made mesh on the posterior side (posterior mesh). The synovial membrane, lined by synovial macrophages, was usually restricted to the recesses in the medial or inferior end of the joint cavity. Without the synovial lining, elastic fibers of the capsular ligament were subsequently detached, dispersed, and exposed to the joint cavity. We also observed a folded and thickened synovial membrane and a hypertrophic protrusion of the capsular ligament. In six specimens, the joint cavity was obliterated by debris of synovial folds and elastic fiber-rich tissues continuous with the usual capsular ligament. Notably, with the exception of two specimens, we did not find lymphocyte infiltration in the degenerative synovial tissue. DISCUSSION: We considered the CT joint degeneration to be a specific, silent form of osteoarthritis from the absence of lymphocyte infiltration. For high-pitched phonation, the elderly CT joint seemed to maintain its anterior gliding and rotation with the aid of elastic fiber-rich tissues compensating for the loss of congruity between the joint cartilage surfaces. Conversely, however, high-pitched phonation may accelerate obliteration of the joint.


Assuntos
Cartilagem Aritenoide/anatomia & histologia , Cartilagem Cricoide/anatomia & histologia , Tecido Elástico/anatomia & histologia , Articulações/anatomia & histologia , Membrana Sinovial/anatomia & histologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Cartilagem Aritenoide/química , Cartilagem Aritenoide/fisiologia , Biópsia , Cadáver , Cartilagem Cricoide/química , Cartilagem Cricoide/fisiologia , Dissecação , Tecido Elástico/química , Tecido Elástico/fisiologia , Feminino , Humanos , Imuno-Histoquímica , Japão , Articulações/química , Articulações/fisiologia , Masculino , Fonação , Membrana Sinovial/química , Membrana Sinovial/fisiologia , Voz
16.
Equine Vet J ; 37(3): 250-6, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15892235

RESUMO

REASONS FOR PERFORMING STUDY: The importance of osteoarthritis (OA) in the horse and the difficulty in its early diagnosis have led to a search for potential biomarkers of joint disease. If the levels of such markers are to be interpreted accurately, clinicians and researchers need to know whether they are influenced by environmental factors and/or interventions such as exercise and repeated arthrocentesis. OBJECTIVE: To investigate the influence of repeated arthrocentesis and exercise on nitric oxide (NO), prostaglandin E2 (PGE2) and glycosaminoglycan (GAG) concentrations in synovial fluid (SF) from normal equine joints. METHODS: SF was collected from the left metacarpophalangeal (MCP), radiocarpal and tarsocrural joints of 16 horses. Half of the horses were exercised and arthrocentesis was repeated 14, 14.5, 17 and 24 days after the start of the exercise programme, in both exercised and control horses. Nitric oxide was determined in SF from the MCP joint only and PGE2 and GAG concentrations were determined in SF from all joints. RESULTS: Repeated arthrocentesis caused an increase in NO concentration in the MCP joint on Day 145, in PGE2 concentrations in the radiocarpal and tarsocrural joints on Day 145 and the release of GAGs into SF of the MCP and radiocarpal joints on Day 17. Exercise resulted in an increase in PGE2 levels in all joints but did not influence the other parameters measured. POTENTIAL RELEVANCE: Repeated arthrocentesis is a potential confounding factor for the use of synovial NO, PGE2 and GAG concentrations as markers of joint disease. Based on this study, such a confounding effect can be avoided if one week or more separates arthrocentesis procedures. Moderate exercise causes a transient rise in PGE2 in SF.


Assuntos
Dinoprostona/análise , Glicosaminoglicanos/análise , Cavalos/metabolismo , Óxido Nítrico/análise , Condicionamento Físico Animal , Líquido Sinovial/química , Animais , Biomarcadores/análise , Feminino , Doenças dos Cavalos/diagnóstico , Artropatias/diagnóstico , Artropatias/veterinária , Articulações/química , Masculino , Paracentese/efeitos adversos , Paracentese/métodos , Paracentese/veterinária , Condicionamento Físico Animal/efeitos adversos , Fatores de Tempo
17.
Equine Vet J ; 37(2): 172-4, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15779632

RESUMO

REASONS FOR PERFORMING STUDY: The centrodistal (CD) and tarsometatarsal (TMT) joints are often injected individually with a corticosteroid to resolve lameness caused by osteoarthritis (OA). There are no data available regarding diffusion of methylprednisolone (MP) from the TMT joint to the CD joint. HYPOTHESIS: A therapeutic concentration of MP diffuses into the CD joint after methylprednisolone acetate (MPA) is administered into the TMT joint. OBJECTIVE: To measure the concentration of MP in the CD joint after MPA was administered into the TMT joint. METHODS: MPA was administered into a TMT joint of 16 horses. At different times, the ipsilateral CD joint of these horses was injected with a small amount of saline and recovered saline was measured for concentration of MP using high performance liquid chromatography. RESULTS: Six hours after administration of MPA into the TMT joint, a therapeutic concentration of MP was found in all 10 CD joints sampled at this time. CONCLUSIONS: Horses with pain arising from the distal 2 joints of the hock can be treated by administering MPA into the TMT joint alone. POTENTIAL RELEVANCE: Administering MPA into the TMT joint only, to treat OA of the distal 2 hock joints, reduces the difficulties and risks associated with centesis of the CD joint.


Assuntos
Anti-Inflamatórios/farmacocinética , Doenças dos Cavalos/tratamento farmacológico , Articulações/metabolismo , Metilprednisolona/análogos & derivados , Metilprednisolona/análise , Metilprednisolona/farmacocinética , Osteoartrite/veterinária , Animais , Anti-Inflamatórios/administração & dosagem , Cadáver , Cromatografia Líquida de Alta Pressão/veterinária , Cavalos , Injeções Intra-Articulares/veterinária , Articulações/química , Metilprednisolona/administração & dosagem , Acetato de Metilprednisolona , Osteoartrite/tratamento farmacológico , Líquido Sinovial/química , Líquido Sinovial/metabolismo
18.
J Bone Miner Res ; 13(1): 88-95, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9443794

RESUMO

Methionine-enkephalin (met-enk), an endogenous opiate, mimics many of the effects of morphine by binding to opiate receptors, thereby eliciting similar cellular and behavioral effects. Using biochemical and immunohistochemical techniques, several peptides have been identified in bone and joint tissues. Here we report, for the first time, the presence as well as concentration of met-enk in bone and joint tissues. Immunohistochemistry using electron and immunofluorescence microscopy showed cellular and neuronal distribution of met-enk in bone and joint tissues. The concentration of met-enk analyzed by high performance liquid chromatography electrochemical detection or radioimmunoassay was high in bone marrow, periosteum, ankle joint tissue, and cortical bone. Analysis by fast atom bombardment mass spectrometry suggested that the recovered fragment was met-enk Administration of met-enk inhibits osteoblast cell growth in culture, which is reversible by naltrexone. In arthritic rats, the concentration of met-enk was significantly decreased in ankle joints compared with controls, suggesting a role for met-enk in the pathophysiology of adjuvant arthritis.


Assuntos
Osso e Ossos/química , Encefalina Metionina/análise , Articulações/química , Animais , Artrite Experimental/metabolismo , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Imuno-Histoquímica , Microscopia de Fluorescência , Microscopia Imunoeletrônica , Osteoblastos/química , Radioimunoensaio , Ratos , Ratos Endogâmicos Lew , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Tarso Animal/química
19.
Pain ; 86(1-2): 69-74, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10779662

RESUMO

This study examined the release of several amino acids after induction of knee joint inflammation in rats using kaolin and carrageenan. During the initial 10-min collection after knee joint injection with the irritants, the concentration of glutamate and the nitric oxide metabolites, arginine and citrulline, doubled. This increase persisted for at least two hours. During the same time period aspartate concentrations remained unchanged. Direct knee joint administration of lidocaine prevented the increases in amino acid concentration measurable by microdialysis probe inserted into the joint. These data suggest the possibility that glutamate may be released by neuronal endings in the joint.


Assuntos
Aminoácidos/metabolismo , Artrite/metabolismo , Articulações/metabolismo , Dor/metabolismo , Aminoácidos/análise , Anestésicos Locais/administração & dosagem , Anestésicos Locais/farmacologia , Animais , Arginina/metabolismo , Artrite/induzido quimicamente , Carragenina , Cromatografia Líquida de Alta Pressão , Citrulina/metabolismo , Ácido Glutâmico/metabolismo , Membro Posterior/fisiologia , Injeções Intra-Articulares , Articulações/química , Caulim , Lidocaína/administração & dosagem , Lidocaína/farmacologia , Masculino , Ratos , Ratos Sprague-Dawley , Líquido Sinovial/efeitos dos fármacos , Líquido Sinovial/metabolismo
20.
J Orthop Res ; 21(3): 465-9, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12706019

RESUMO

The occurrence of methionine-enkephalin-Arg(6)-Phe(7) (MEAP) and dynorphin B (DYNB) representing two main precursors of opioids was analyzed in specimens from rat cortical bone, periosteum, bone marrow and joint tissue by radioimmunoassay (RIA). MEAP and DYNB were extracted in a solution of 4% EDTA in 2 M acetic acid previously proven suitable for extraction of sensory and autonomic neuropeptides in bone and joints. In crude extracts of cortical bone, the immunoreactive (ir) levels of both opioids were under the detection limit of RIA. As for DYNB this also applied to crude extracts of joints and periosteum. Therefore, two purification methods were tested and compared, i.e. reverse phase C 18 and ion exchange chromatography. RIA of the elution fraction disclosed a significant difference between the two methods in terms of recovery, i.e. <5% and 50%, respectively. Thus, purification by ion exchange chromatography prior to RIA appeared to be the most suitable by providing measurable levels of both MEAP and DYNB in all tissues analyzed (highest in bone marrow, lowest in cortical bone). The described method offers a means of quantifying opioid peptides in bone and joints, which may be utilized in the analysis of regulatory mechanisms of nociception, growth and immune responses in different conditions.


Assuntos
Osso e Ossos/química , Dinorfinas/isolamento & purificação , Endorfinas/isolamento & purificação , Encefalina Metionina/análogos & derivados , Encefalina Metionina/isolamento & purificação , Articulações/química , Radioimunoensaio/métodos , Animais , Cromatografia por Troca Iônica , Masculino , Radioimunoensaio/normas , Ratos , Ratos Endogâmicos Lew , Reprodutibilidade dos Testes
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