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1.
Bone Joint J ; 102-B(2): 205-211, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32009424

RESUMO

AIMS: To evaluate the donor site morbidity and tendon morphology after harvesting whole length, full-thickness peroneus longus tendon (PLT) proximal to the lateral malleolus for ligament reconstructions or tendon transfer. METHODS: A total of 21 eligible patients (mean age 34.0 years (standard deviation (SD) 11.2); mean follow-up period 31.8 months (SD 7.7), and 12 healthy controls (mean age, 26.8 years (SD 5.9) were included. For patients, clinical evaluation of the donor ankle was performed preoperatively and postoperatively. Square hop test, ankle strength assessment, and MRI of distal calf were assessed bilaterally in the final follow-up. The morphological symmetry of peroneal tendons bilaterally was evaluated by MRI in healthy controls. RESULTS: Among the patients, the mean pre- and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score and Karlsson-Peterson score were 98.7 (SD 2.5; p = 0.480) and 98.5 (SD 2.4; p = 0.480), and 98.3 (SD 2.4; p = 0.162) and 97.9 (SD 2.5; p = 0.162), respectively. There was no significant difference between square hop test bilaterally (p = 0.109) and plantar flexion peak force bilaterally (p = 0.371). The harvested limb had significantly less eversion peak force compared to the contralateral limb (p < 0.001). Evidence of probable tendon regeneration was observed in all the patients by MRI and the total bilateral peroneal tendon index (mean ratio of harvested side cross-sectional area of peroneal tendon compared with the contralateral side) was 82.9% (SD 17.4). In 12 healthy controls, peroneal tendons (mean 99.4% (SD 4.3) were found to be morphologically symmetrical between the two sides. CONCLUSION: The current study showed satisfactory clinical foot and ankle outcomes after full-thickness PLT harvesting and indicated the regenerative potential of PLT after its removal. Level of Evidence: Level IV, therapeutic retrospective case series. Cite this article: Bone Joint J 2020;102-B(2):205-211.


Assuntos
Articulação do Tornozelo/fisiopatologia , Tornozelo/fisiopatologia , Pé/fisiopatologia , Ligamentos Articulares/fisiopatologia , Tendões/transplante , Sítio Doador de Transplante/fisiopatologia , Adulto , Tornozelo/diagnóstico por imagem , Articulação do Tornozelo/diagnóstico por imagem , Feminino , Pé/diagnóstico por imagem , Humanos , Ligamentos Articulares/cirurgia , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Reconstrutivos , Recuperação de Função Fisiológica , Regeneração , Estudos Retrospectivos , Transferência Tendinosa , Tendões/diagnóstico por imagem , Tendões/fisiologia , Coleta de Tecidos e Órgãos/métodos , Coleta de Tecidos e Órgãos/reabilitação , Sítio Doador de Transplante/diagnóstico por imagem , Transplante Autólogo , Resultado do Tratamento , Adulto Jovem
2.
J Orthop Res ; 38(1): 7-12, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31529731

RESUMO

Ligament and tendon injuries are common problems in orthopedics. There is a need for treatments that can expedite nonoperative healing or improve the efficacy of surgical repair or reconstruction of ligaments and tendons. Successful biologically-based attempts at repair and reconstruction would require a thorough understanding of normal tendon and ligament healing. The inflammatory, proliferative, and remodeling phases, and the cells involved in tendon and ligament healing will be reviewed. Then, current research efforts focusing on biologically-based treatments of ligament and tendon injuries will be summarized, with a focus on stem cells endogenous to tendons and ligaments. Statement of clinical significance: This paper details mechanisms of ligament and tendon healing, as well as attempts to apply stem cells to ligament and tendon healing. Understanding of these topics could lead to more efficacious therapies to treat ligament and tendon injuries. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:7-12, 2020.


Assuntos
Ligamentos/lesões , Traumatismos dos Tendões/terapia , Tendões/fisiologia , Cicatrização , Animais , Humanos , Ligamentos/anatomia & histologia , Ligamentos/fisiologia , Tendões/anatomia & histologia
3.
J Shoulder Elbow Surg ; 29(1): 157-166, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31401128

RESUMO

BACKGROUND: The purpose of this study was to evaluate the biomechanical and histologic properties of rotator cuff repairs using a vented anchor attached to a bioresorbable interpositional scaffold composed of aligned PLGA (poly(l-lactide-co-glycoside)) microfibers in an animal model compared to standard anchors in an ovine model. METHODS: Fifty-six (n = 56) skeletally mature sheep were randomly assigned to a repair of an acute infraspinatus tendon detachment using a innovative anchor-PLGA scaffold device (Treatment) or a similar anchor without the scaffold (Control). Animals were humanely euthanized at 7 and 12 weeks post repair. Histologic and biomechanical properties of the repairs were evaluated and compared. RESULTS: The Treatment group had a significantly higher fibroblast count at 7 weeks compared to the Control group. The tendon bone repair distance, percentage perpendicular fibers, new bone formation at the tendon-bone interface, and collagen type III deposition was significantly greater for the Treatment group compared with the Control group at 12 weeks (P ≤ .05). A positive correlation was identified in the Treatment group between increased failure loads at 12 weeks and the following parameters: tendon-bone integration, new bone formation, and collagen type III. No statistically significant differences in biomechanical properties were identified between Treatment and Control Groups (P > .05). CONCLUSIONS: Use of a vented anchor attached to a bioresorbable interpositional scaffold composed of aligned PLGA microfibers improves the histologic properties of rotator cuff repairs in a sheep model. Improved histology was correlated with improved final construct strength at the 12-week time point.


Assuntos
Osso e Ossos/fisiologia , Lesões do Manguito Rotador/cirurgia , Tendões/fisiologia , Tecidos Suporte , Cicatrização , Implantes Absorvíveis , Animais , Materiais Biocompatíveis/uso terapêutico , Fenômenos Biomecânicos , Osso e Ossos/cirurgia , Contagem de Células , Colágeno Tipo III/metabolismo , Modelos Animais de Doenças , Feminino , Fibroblastos , Osteogênese , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/uso terapêutico , Estudos Prospectivos , Lesões do Manguito Rotador/patologia , Ovinos , Técnicas de Sutura , Tendões/cirurgia
4.
Gait Posture ; 75: 149-154, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31683185

RESUMO

BACKGROUND: Gastrocnemius medialis (GM) and lateralis (GL) act at the ankle complex in the sagittal and frontal planes and there is evidence that their actions can be somewhat uncoupled from each other. Some independence of GM and GL from each other could be advantageous, e.g. to stabilise the ankle complex in unstable walking conditions. Given the compartmentalised structure of the Achilles tendon, the sub-tendons of GM and GL may exhibit different elongation during plantarflexion contractions, particularly with the foot in different frontal plane positions. RESEARCH QUESTIONS: METHODS: Sub-tendon elongation was determined from 18 participants during ramped isometric plantarflexion contractions to 70% of their maximum voluntary contraction (MVC) level with the foot in neutral, inversion and eversion. One-dimensional statistical parametric mapping was applied to determine elongation differences. RESULTS: Elongation within a sub-tendon did not differ in the three foot positions. Elongation was similar between both sub-tendons at very low contraction levels, but GM sub-tendon elongation exceeded GL sub-tendon displacement significantly from 30% MVC. The elongation differences between the sub-tendons were not affected by foot position. SIGNIFICANCE: Greater GM sub-tendon elongation is likely caused by the greater force production capability of GM but may also indicate that the sub-tendons of GM and GL have different mechanical properties, which is currently unknown. Elongation differences were contraction level dependent suggesting that contributions of GM and GL to plantarflexion torque may also be contraction level dependent.


Assuntos
Articulação do Tornozelo/fisiologia , Pé/fisiologia , Músculo Esquelético/fisiologia , Tendões/fisiologia , Tendão do Calcâneo/fisiologia , Adulto , Feminino , Humanos , Contração Isométrica/fisiologia , Masculino , Pessoa de Meia-Idade , Torque
5.
J Orthop Res ; 38(1): 23-35, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31410892

RESUMO

Extracellular matrix (ECM) determines the physiological function of all tissues, including musculoskeletal tissues. In tendon, ECM provides overall tissue architecture, which is tailored to match the biomechanical requirements of their physiological function, that is, force transmission from muscle to bone. Tendon ECM also constitutes the microenvironment that allows tendon-resident cells to maintain their phenotype and that transmits biomechanical forces from the macro-level to the micro-level. The structure and function of adult tendons is largely determined by the hierarchical organization of collagen type I fibrils. However, non-collagenous ECM proteins such as small leucine-rich proteoglycans (SLRPs), ADAMTS proteases, and cross-linking enzymes play critical roles in collagen fibrillogenesis and guide the hierarchical bundling of collagen fibrils into tendon fascicles. Other non-collagenous ECM proteins such as the less abundant collagens, fibrillins, or elastin, contribute to tendon formation or determine some of their biomechanical properties. The interfascicular matrix or endotenon and the outer layer of tendons, the epi- and paratenon, includes collagens and non-collagenous ECM proteins, but their function is less well understood. The ECM proteins in the epi- and paratenon may provide the appropriate microenvironment to maintain the identity of distinct tendon cell populations that are thought to play a role during repair processes after injury. The aim of this review is to provide an overview of the role of non-collagenous ECM proteins and less abundant collagens in tendon development and homeostasis. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:23-35, 2020.


Assuntos
Colágeno/fisiologia , Proteínas da Matriz Extracelular/fisiologia , Tendões/fisiologia , Animais , Decorina/fisiologia , Fibromodulina/fisiologia , Glicosaminoglicanos/fisiologia , Humanos , Tenascina/fisiologia , Engenharia Tecidual
6.
Nat Commun ; 10(1): 4825, 2019 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-31645555

RESUMO

Natural creatures, from fish and cephalopods to snakes and birds, combine neural control, sensory feedback and compliant mechanics to effectively operate across dynamic, uncertain environments. In order to facilitate the understanding of the biophysical mechanisms at play and to streamline their potential use in engineering applications, we present here a versatile numerical approach to the simulation of musculoskeletal architectures. It relies on the assembly of heterogenous, active and passive Cosserat rods into dynamic structures that model bones, tendons, ligaments, fibers and muscle connectivity. We demonstrate its utility in a range of problems involving biological and soft robotic scenarios across scales and environments: from the engineering of millimeter-long bio-hybrid robots to the synthesis and reconstruction of complex musculoskeletal systems. The versatility of this methodology offers a framework to aid forward and inverse bioengineering designs as well as fundamental discovery in the functioning of living organisms.


Assuntos
Bioengenharia , Simulação por Computador , Articulação do Cotovelo/fisiologia , Plumas/fisiologia , Fenômenos Fisiológicos Musculoesqueléticos , Asas de Animais/fisiologia , Animais , Osso e Ossos/fisiologia , Humanos , Ligamentos/fisiologia , Músculo Esquelético/fisiologia , Sistema Musculoesquelético , Amplitude de Movimento Articular/fisiologia , Robótica , Tendões/fisiologia
7.
IEEE Int Conf Rehabil Robot ; 2019: 682-688, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374710

RESUMO

This paper presents a compliant, underactuated finger for the development of anthropomorphic robotic and prosthetic hands. The finger achieves both flexion/extension and adduction/abduction on the metacarpophalangeal joint, by using two actuators. The design employs moment arm pulleys to drive the tendon laterally and amplify the abduction motion, while also maintaining the flexion motion. Particular emphasis has been given to the analysis of the mechanism. The proposed finger has been fabricated with the hybrid deposition manufacturing technique and the actuation mechanism's efficiency has been validated with experiments that include the computation of the reachable workspace, the assessment of the exerted forces at the fingertip, the demonstration of the feasible motions, and the presentation of the grasping and manipulation capabilities. The proposed mechanism facilitates the collaboration of the two actuators to increase the exerted finger forces. Moreover, the extended workspace allows the execution of dexterous manipulation tasks.


Assuntos
Dedos/fisiologia , Fenômenos Biomecânicos , Complacência (Medida de Distensibilidade) , Humanos , Articulações/fisiologia , Rotação , Tendões/fisiologia
8.
IEEE Int Conf Rehabil Robot ; 2019: 1025-1030, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374764

RESUMO

Somatosensory Evoked Potentials (SSEPs) are an important tool for both basic neuroscience research and evaluation of therapeutic techniques. While a large body of work exists in the study of electrically induced SSEPs both as a metric for therapeutic performance and tool for physiological research, comparatively little work has explored stretch response SSEPs evoked via tendon tapping. The measurement of SSEPs necessitates both timing and stimulation intensity consistency. This work presents an evaluation of a simple tapping device for automating this procedure and a comparison to manual tendon tapping demonstrating significantly reduced variability in both timing and intensity. The variable intensity nature of automated tapping is then used to measure SSEPs in a single subject, with apparent modulation of peak-peak amplitude by stimulation intensity.


Assuntos
Potenciais Somatossensoriais Evocados/fisiologia , Tendões/fisiologia , Humanos , Modelos Teóricos
9.
IEEE Int Conf Rehabil Robot ; 2019: 1073-1078, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374772

RESUMO

A new tendon driven mechanism, embedded into a soft hand exoskeleton for rehabilitation and assistance, was proposed in this study. The proposed solution was a pulley flexion mechanism inspired by the human musculoskeletal system to enable a natural and comfortable finger flexion. A biomechanical constraint for the finger flexion motion states that the relation between the proximal interphalangeal joint angle of the finger should always be flexed around 1.5 times the distal interphalangeal joint angle. The study aimed to comply with this constraint, by simultaneously distributing the forces over the distal and middle finger phalanges. For evaluation, the voluntary and exoskeleton flexions were compared based on the relation between the proximal and distal interphalangeal joint angles. The results showed that during the exoskeleton flexion the relation between the interphalangeal joints complied with the biomechanical constraint, where the proximal interphalangeal joint angle was 1.5 times larger than the distal interphalangeal joint. This ensures that the mechanism flexes the finger comfortably. The proposed solution is therefore a promising design for a novel soft exoskeleton that will be used for training and assistance of patients with hand paralysis.


Assuntos
Exoesqueleto Energizado , Articulações dos Dedos/fisiologia , Tendões/fisiologia , Adulto , Humanos , Masculino , Amplitude de Movimento Articular/fisiologia
10.
IEEE Int Conf Rehabil Robot ; 2019: 1233-1238, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374798

RESUMO

Performance of lower limb prostheses is related not only to the mechanical design and the control scheme, but also to the feedback provided to the user. Proprioceptive feedback, which is the sense of position and movement of one's body parts, can improve the utility as well as facilitate the embodiment of the prosthetic device. Recent studies have shown that proprioceptive kinesthetic (movement) sense can be elicited when non-invasively vibrating a muscle tendon proximal to the targeted joint. However, consistency and quality of the elicited sensation depend on several parameters and muscle tendons after lower limb amputation may not always be accessible. In this study, we developed an experimental protocol to quantitatively and qualitatively assess the elicited proprioceptive kinesthetic illusion when non-invasively vibrating a muscle belly. Furthermore, we explored ways to improve consistency and strength of the illusion by integrating another non-invasive feedback method, namely cutaneous information manipulation via skin stretch. Our preliminary results from tests conducted with a person with transtibial (below knee) amputation show that stretching skin while vibrating a muscle belly on the residual limb provided a stronger and more consistent kinesthetic illusion (90%) than only vibrating the muscle (50%). In addition, we found that stretching skin enhances the range (1.5 times) and speed (3.5 times) of the illusory movement triggered by muscle vibration. These findings may enable the development of mechanisms for controlling feedback parameters in closing the control loop for various walking routines, which may improve performance of lower limb prostheses.


Assuntos
Amputação , Ilusões/fisiologia , Extremidade Inferior/cirurgia , Pele , Humanos , Masculino , Pessoa de Meia-Idade , Movimento/fisiologia , Músculo Esquelético/fisiologia , Tendões/fisiologia
12.
Med Sci Sports Exerc ; 51(9): 1961-1970, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31415444

RESUMO

PURPOSE: The purpose of this study was to compare the development and etiology of neuromuscular fatigue of the knee extensor muscles at different muscle-tendon unit (MTU) lengths during repeated maximal voluntary isometric contractions (MVIC) between boys and men. METHODS: Twenty-two prepubertal boys (9-11 yr) and 22 men (18-30 yr) performed three knee extensor fatigue protocols at short (SHORT), optimal (OPT), and long (LONG) MTU lengths, consisting of repeating 5-s MVIC interspersed with 5-s passive recovery periods until torque reached 60% of the initial MVIC torque. The etiology of neuromuscular fatigue was identified using noninvasive methods such as surface electromyography, near-infrared spectroscopy, magnetic nerve stimulation and twitch interpolation technique. RESULTS: The number of repetitions was significantly lower in men at OPT (14.8 ± 3.2) and LONG (15.8 ± 5.8) than boys (39.7 ± 18.4 and 29.5 ± 10.2, respectively; P < 0.001), whereas no difference was found at SHORT between both age groups (boys, 33.7 ± 15.4; men, 40.9 ± 14.2). At OPT and LONG boys showed a lower reduction in the single potentiated twitch (Qtwpot) and a greater decrease in the voluntary activation level than men. At SHORT, both populations displayed a moderate Qtwpot decrement and a significant voluntary activation reduction (P < 0.001). The differences in maximal torque between boys and men were almost twice greater at OPT (223.9 N·m) than at SHORT (123.3 N·m) and LONG (136.5 N·m). CONCLUSIONS: The differences in neuromuscular fatigue between children and adults are dependent on MTU length. Differences in maximal torque could underpin differences in neuromuscular fatigue between children and adults at OPT and SHORT. However, at LONG these differences do not seem to be explained by differences in maximal torque. The origins of this specific effect of MTU length remain to be determined.


Assuntos
Contração Isométrica/fisiologia , Fadiga Muscular/fisiologia , Músculo Esquelético/fisiologia , Tendões/fisiologia , Adolescente , Adulto , Criança , Eletromiografia , Humanos , Joelho/fisiologia , Magnetismo , Músculo Esquelético/inervação , Torque , Adulto Jovem
13.
ACS Appl Mater Interfaces ; 11(30): 26559-26570, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31267742

RESUMO

Recently, the scientific community has shown considerable interest in engineering tissues with organized compositional and structural gradients to mimic hard-to-soft tissue interfaces. This effort is hindered by an incomplete understanding of the construction of native tissue interfaces. In this work, we combined Raman microscopy and confocal elastography to map compositional, structural, and mechanical features across the stiff-to-compliant interface of the attachments of the meniscus in the knee. This study provides new insight into the methods by which biology mediates multiple orders of magnitude changes in stiffness over tens of microns. We identified how the nano- to mesoscale architecture mediates complex microscale transitional regions across the interface: two regions defined by chemical composition, five distinguished by structural features, and three mechanically distinct regions. We identified three major components that lead to a robust interface between a soft tissue and bone: mobile collagen fiber units, a continuous interfacial region, and a local stiffness gradient. This tissue architecture allows for large displacements of collagen fibers in the attachments, enabling meniscal movement without localizing strains to the soft tissue-to-bone interface. The interplay of these regions reveals a method relying on hierarchical structuring across multiple length scales to minimize stress concentrators between highly dissimilar materials. These insights inspire new design strategies for synthetic soft tissue-to-bone attachments and biomimetic material interfaces.


Assuntos
Materiais Biomiméticos/uso terapêutico , Articulação do Joelho/fisiologia , Menisco/fisiologia , Tendões/fisiologia , Osso e Ossos/fisiologia , Matriz Extracelular/fisiologia , Humanos , Engenharia Tecidual , Tecidos Suporte
14.
Int J Biol Macromol ; 138: 79-88, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31295489

RESUMO

This study investigates if the application of bone marrow-derived mesenchymal stem cells (BM-MSCs) loaded 3D-printed scaffolds could improve rotator cuff repair. The polylactic-co-glycolic acid (PLGA) scaffolds were fabricated by 3D print technology. Rabbit BM-MSCs were transfected with a recombinant adenovirus encoding bone morphogenic protein 12 (BMP-12). The effect of BM-MSCs loaded PLGA scaffolds on tendon-bone healing was assessed by biomechanical testing and histological analysis in a rabbit rotator cuff repair model. We found that the PLGA scaffolds had good biocompatible and biodegradable property. Overexpression of BMP-12 increased the mRNA and protein expression of tenogenic genes in BM-MSCs cultured with DMEM medium and seeded in PLGA scaffolds. When BMP-12-overexpressing BM-MSCs-loaded PLGA scaffolds were implanted into the injured rabbit supraspinatus tendon-bone junctions, the tendon-bone healing was improved. Our results suggest that application of BMP-12 overexpressing BM-MSCs loaded 3D-printed PLGA scaffolds promote the healing of tendon-bone interface, improve collagen organization and increase fibrocartilage in the rabbit rotor cuff repair. Rotator cuff regeneration achieved by BMP-12-overexpressing BM-MSCs-loaded PLGA scaffolds may represent a novel approach for the management of rotator cuff defect.


Assuntos
Proteínas Morfogenéticas Ósseas/genética , Células-Tronco Mesenquimais/metabolismo , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Impressão Tridimensional , Manguito Rotador/fisiologia , Tecidos Suporte/química , Animais , Biomarcadores/metabolismo , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Expressão Gênica , Células-Tronco Mesenquimais/química , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/farmacologia , Coelhos , Regeneração , Tendões/fisiologia
15.
Poult Sci ; 98(11): 5613-5621, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31222275

RESUMO

This study focused on analyzing the effects of inclusion of modern hybrid rye to corn-wheat diet on mechanical properties of bones and tendons. A total of 224 broiler chickens were fed a diet without rye inclusion or a diet containing 15% of hybrid rye cv. Brasetto. The diets were either unsupplemented or supplemented with xylanase (minimum activity 1000 FXU/g, dose 200 mg/kg of feed). Each dietary group consisted of 56 birds. On day 42, selected chickens (n = 7 from each group) were slaughtered. Tibia were analyzed for mineralization, geometry, and biomechanical characteristics of bone mid-diaphysis. The mechanical properties of digital flexor III tendon were also assessed. Bone mineral density and bone ash percentage did not differ when both diets were given without xylanase. Enzyme supplementation increased bone mineral density (P < 0.01) in both dietary groups, whereas bone ash percentage (P < 0.01) increased only for corn-wheat diet. Rye inclusion had no effect on bone mid-shaft geometrical traits related to tibia weight-bearing capacity (cross-sectional area, cortical index, and mean relative wall thickness). Performed bending test showed no effect of hybrid rye inclusion on bone mechanical endurance. When xylanase was supplemented, bone length (P < 0.01) and weight (P < 0.05) decreased, whereas yield load (P < 0.01), stiffness (P < 0.05), Young modulus (P < 0.05), elastics stress (P < 0.01), and ultimate stress (P < 0.01) increased, irrespective of rye presence. The tendon tensile strain test showed that in corn-wheat diet enzyme supplementation positively influenced rupture force (P < 0.05) and tendon stiffness (P < 0.01). Xylanase supplementation increased the value of energy required to tendon rupture, irrespective of rye inclusion (P < 0.05). Study showed that modern hybrid rye varieties can be introduced to corn-wheat diets of broiler chickens in the aspect of animal welfare related to the development and homeostasis of musculoskeletal system, irrespective of xylanase supplementation. The enzyme addition positively affected biomechanical properties of bones and tendons.


Assuntos
Osso e Ossos/fisiologia , Galinhas/fisiologia , Endo-1,4-beta-Xilanases/metabolismo , Secale/química , Tendões/fisiologia , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Animais , Fenômenos Biomecânicos , Dieta/veterinária , Suplementos Nutricionais/análise , Endo-1,4-beta-Xilanases/administração & dosagem , Masculino , Distribuição Aleatória , Triticum/química , Zea mays/química
16.
J Orthop Res ; 37(11): 2476-2485, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31231903

RESUMO

Tendon injuries are very common and disrupt the transmission of forces from muscle to bone, leading to impaired function and quality of life. Successful restoration of tendon function after injury is a challenging clinical problem due to the pathological, scar-mediated manner in which the tendons heal. Currently, there are no standard treatments to modulate scar tissue formation and improve tendon healing. A major limitation to the identification of therapeutic candidates has been the reliance on terminal endpoint metrics of healing in pre-clinical studies, which require a large number of animals and result in destruction of the tissue. To address this limitation, we have identified quantification of scar tissue volume (STV) from ultrasound (US) imaging as a longitudinal, non-invasive metric of tendon healing. STV was strongly correlated with established endpoint metrics of gliding function including gliding resistance and metatarsophalangeal (MTP) flexion angle. However, no associations were observed between STV and structural or material properties. To define the sensitivity of STV to identify differences between functionally discrete tendon healing phenotypes, we utilized S100a4 haploinsufficient mice (S100a4GFP/+ ), which heal with improved gliding function relative to wild-type (WT) littermates. A significant decrease in STV was observed in S100a4GFP/+ repairs, relative to WT at day 14. Taken together, these data suggest US quantification of STV as a means to facilitate the rapid screening of biological and pharmacological interventions to improve tendon healing, and identify promising therapeutic targets, in an efficient, cost-effective manner. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2476-2485, 2019.


Assuntos
Cicatriz/diagnóstico por imagem , Traumatismos dos Tendões/diagnóstico por imagem , Tendões/diagnóstico por imagem , Ultrassonografia/métodos , Animais , Cicatriz/fisiopatologia , Feminino , Fibrose , Masculino , Camundongos , Traumatismos dos Tendões/fisiopatologia , Tendões/patologia , Tendões/fisiologia , Cicatrização
17.
Croat Med J ; 60(3): 201-211, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31187947

RESUMO

AIM: To assess whether an adenoviral vector carrying the bone morphogenetic protein genes (Ad.BMP-2) can transduce human muscle tissue and direct it toward osteogenic differentiation within one hour. METHODS: This in vitro study, performed at the Department of Molecular Biology, Faculty of Science, Zagreb from 2012 to 2017, used human muscle tissue samples collected during anterior cruciate ligament reconstructions performed in St Catherine Hospital, Zabok. Samples from 28 patients were transduced with adenoviral vector carrying firefly luciferase cDNA (Ad.luc) by using different doses and times of transduction, and with addition of positive ions for transduction enhancement. The optimized protocol was further tested on muscle samples from three new patients, which were transduced with Ad.BMP-2. Released bone morphogenetic protein 2 (BMP-2) levels in osteogenic medium were measured every three days during a period of 21 days. Expression of osteogenic markers was measured at day 14 and 21. After 21 days of cultivation, muscle tissue was immunohistochemically stained for collagen type I detection (COL-I). RESULTS: The new transduction protocol was established using 108 plaque-forming units (P<0.001) as an optimal dose of adenoviral vector and 30 minutes (P<0.001) as an optimal contact time. Positive ions did not enhance transduction. Samples transduced with Ad.BMP-2 according to the optimized protocol showed enhanced expression of osteogenic markers (P<0.050), BMP-2 (P<0.001), and COL I. CONCLUSION: This study confirms that Ad.BMP-2 can transduce human muscle tissue and direct it toward osteogenic differentiation within 30 minutes.


Assuntos
Proteína Morfogenética Óssea 2/genética , Proteína Morfogenética Óssea 2/metabolismo , Diferenciação Celular/genética , Músculo Esquelético/fisiologia , Osteogênese/genética , Transdução Genética , Adenoviridae , Adolescente , Adulto , Células Cultivadas , Melhoramento Genético , Vetores Genéticos , Humanos , Pessoa de Meia-Idade , Tendões/fisiologia , Adulto Jovem
18.
J Sports Sci Med ; 18(2): 351-358, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31191106

RESUMO

We investigated the acute effects of dynamic stretching on mechanical properties of plantar flexor muscles and tested the hypothesis that it would result from an interaction between muscle-tendon stretching and muscle warm-up. To test the stretching effect, dynamic stretching (DS) was compared to static stretching (SS). To test the warm-up effect, DS was compared to submaximal isometric muscle activity (SIMA) with similar contraction intensity. A control condition served as reference. These four conditioning activities were time matched (2×20s) and tested on separate days on 13 volunteers. Electrical neurostimulation was applied to investigate muscle mechanical properties (peak doublet torque (PDT) and rate of torque development (RTD)), before assessing maximal voluntary isometric torque (MVIT). Passive torque and muscle fascicles length, were measured respectively with a dynamometer and ultrasonography during a maximal passive dorsiflexion. These parameters were recorded before and after each conditioning activities. MVIT, PDT, RTD and fascicles length remained unaffected, while passive torque was significantly reduced (-11.6 ± 14.8%) after DS. SS significantly decreased MVIT (-7.7 ± 3.8%) and enhanced fascicles length (45.3 ± 49.2%), whereas SIMA increased PDT (5.8 ± 5.2%) and RTD (7.4 ± 8.3%) without affecting passive torque or fascicles length. These results may suggest that, during dynamic stretching, muscle-tendon stretching effects would partly counteract muscle warm-up effects.


Assuntos
Exercícios de Alongamento Muscular/métodos , Músculo Esquelético/fisiologia , Tendões/fisiologia , Exercício de Aquecimento , Adulto , Fenômenos Biomecânicos , Estudos Cross-Over , Humanos , Masculino , Dinamômetro de Força Muscular , Torque , Ultrassonografia , Adulto Jovem
19.
Proc Inst Mech Eng H ; 233(8): 784-792, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31165672

RESUMO

The objective of this study is to investigate the effects of ligament and tendon detachment on human middle ear sound transfer. For this purpose, a geometric human middle ear model was reconstructed based on the computed tomography scanning data of the temporal bones from healthy adult volunteers. For the ear model, pars tensa was assumed to be fit for a 5-parameter Maxwell model and inverse method was used to obtain the necessary coefficients. Furthermore, frequency response method was implemented to investigate the vibration behaviors of tympanic membrane umbo and stapes footplate under an acoustic stimulus of 90 dB within 0.2-8 kHz. Meanwhile, nine patterns of fractured ligaments and tendons, whose effects on the middle ear sound transfer function were simulated by setting free the nodes of the ligaments and tendons of interest. The results indicate that the displacement of tympanic membrane umbo and stapes footplate as well as the velocity transfer function lies within the bounds of the published experimental data. The detachments of ligaments or tendons except for lateral mallear ligament may incur both gains as much as 15 dB and losses of -8 dB in the velocity of stapes footplate at low frequencies (f≤ 1 kHz), while no significant changes were observed at high frequencies (f > 1 kHz). However, detachment of the ligaments or tendons induces tiny changes in the displacement of stapes footplate at the frequencies of 0.2-8 kHz.


Assuntos
Orelha Média/fisiologia , Ligamentos/fisiologia , Modelos Biológicos , Som , Tendões/fisiologia , Orelha Média/diagnóstico por imagem , Análise de Elementos Finitos , Humanos , Magnetoencefalografia , Masculino , Tomografia Computadorizada por Raios X , Membrana Timpânica/fisiologia , Vibração , Adulto Jovem
20.
J Orthop Res ; 37(8): 1848-1859, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31042311

RESUMO

Extracellular matrix (ECM) is responsible for tendon strength and elasticity. Healed tendon ECM lacks structural integrity, leading to reinjury. Porcine urinary bladder matrix (UBM) provides a scaffold and source of bioactive proteins to improve tissue healing, but has received limited attention for treating tendon injuries. The objective of this study was to evaluate the ability of UBM to induce matrix organization and tenogenesis using a novel in vitro model. We hypothesized that addition of UBM to tendon ECM hydrogels would improve matrix organization and cell differentiation. Hydrogels seeded with bone marrow cells (n = 6 adult horses) were cast using rat tail tendon ECM ± UBM, fixed under static tension and harvested at 7 and 21 days for construct contraction, cell viability, histology, biochemistry, and gene expression. By day 7, UBM constructs contracted significantly from baseline, whereas control constructs did not. Both control and UBM constructs contracted significantly by day 21. In both groups, cells remained viable over time and changed from round and randomly oriented to elongated along lines of tension with visible compaction of the ECM. There were no differences over time or between treatments for nuclear aspect ratio, DNA, or glycosaminoglycan content. Decorin, matrix metalloproteinase 13, and scleraxis expression increased significantly over time, but not in response to UBM treatment. Mohawk expression was constant over time. Cartilage oligomeric matrix protein expression decreased over time in both groups. Using a novel ECM hydrogel model, substantial matrix organization and cell differentiation occurred; however, the addition of UBM failed to induce greater matrix organization than tendon ECM alone. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1848-1859, 2019.


Assuntos
Matriz Extracelular/transplante , Traumatismos dos Tendões/terapia , Tecidos Suporte , Animais , Feminino , Cavalos , Hidrogéis , Masculino , Ratos , Regeneração , Suínos , Tendões/fisiologia , Bexiga Urinária
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