Tendon Samples Research Articles

Sequencing and phylogenetic analysis of partial S1 genes of avian orthoreovirus isolates in Shandong province during 2015–2017

Sequencing and phylogenetic analysis of partial S1 genes of avian orthoreovirus isolates in Shandong province during 2015–2017

Intraoperative graft decontamination during ACL reconstruction surgery.

Objective To evaluate different decontaminants for tendon grafts, proposing an antiseptic protocol for contaminated grafts. Methods A total of 25 patients were tissue donors for the study. Each participant donated a 2.5-cm tendon sample, which was divided into 5 fragments with 5 mm each during anterior cruciate ligament (ACL) reconstruction surgery. The collected material was divided into 5 groups, totaling 125 samples. In total, four fragments of each patient were placed on the operating room floor for one minute for contamination, simulating the fall of the graft on the floor during surgery. The other fragment was immediately placed in a sterile container (group 1). One of the contaminated fragments was placed in the sterile container without being previously immersed in decontaminating solution (group 2). The remaining fragments were immersed for ten minutes in decontaminating solution: 0.5% chlorhexidine (group 3), 0.9% saline (group 4) and 0.55% ortho-phthalaldehyde (group 5), and, after this time, they were individually placed in a sterile container. The samples from the 5 groups were submitted to microbiological examination. Results Bacteria were detected in 26% of the total samples in the microbiological tests, and in group 1 there was no growth of microorganisms. In group 2, bacterial growth was observed in 16 samples. Considering the evaluation of test groups 3, 4 and 5, the percentage of decontamination was higher than the growth of microorganisms in the respective cultures. Conclusion The protocol suggested by the study showed that intraoperative graft decontamination is possible.

Bioinformatics Analysis of the Molecular Mechanism of Late-Stage Heterotopic Ossification.

Background Heterotopic ossification (HO) is a common disease happened in soft tissues after injury. The present study utilized the bioinformatics method to analyze the HO samples in a mouse burn/tenotomy-induced HO model to identify the possible key points and treatment targets. Methods The transcriptome profiles of GSE126118 were obtained from the Gene Expression Omnibus (GEO) database. The study was based on a mouse burn/tenotomy-induced HO model, and 2 tenotomy samples and 3 uninjured contralateral hindlimb tendon samples were collected at 3 weeks after injury for further analysis. The transcripts per million approach was performed for background correction and normalization; then, the differentially expressed genes (DEGs) were detected using the limma R package with the settings p < 0.01 and ∣log2FC∣ > 2.0. The Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and the protein-protein interaction (PPI) network analysis were performed with the detected DEGs. Results A total of 74 DEGs were upregulated, and 159 DEGs were downregulated between the tenotomy and uninjured tendon group. Pathway and process enrichment analyses demonstrated that the upregulated DEGs were mainly associated with terms related to ECM remodeling, ossification, angiogenesis, inflammation, etc., and the downregulated DEGs were mainly associated with oxidative phosphorylation, metabolic process, etc. Conclusion The results of GO, KEGG, and PPI network analyses suggested that the ECM remodeling, ossification, angiogenesis, and inflammation processes were markedly upregulated in the tenotomy site. And the oxidative phosphorylation and metabolic processes were markedly downregulated. These findings provide valuable clues for highlighting the characteristics of late-stage HO and investigating possible treatments.

Tendon healing in presence of chronic low-level inflammation: a systematic review.

Tendinopathy is a common musculoskeletal condition affecting subjects regardless of their activity level. Multiple inflammatory molecules found in ex vivo samples of human tendons are related to the initiation or progression of tendinopathy. Their role in tendon healing is the subject of this review. An extensive review of current literature was conducted using PubMed, Embase and Cochrane Library using the term 'tendon', as well as some common terms of tendon conditions such as 'tendon injury OR (tendon damage) OR tendonitis OR tendinopathy OR (chronic tendonitis) OR tendinosis OR (chronic tendinopathy) OR enthesitis' AND 'healing' AND '(inflammation OR immune response)' as either key words or MeSH terms. An environment characterized by a low level of chronic inflammation, together with increased expression of inflammatory cytokines and growth factors, may influence the physiological tendon healing response after treatment. Most studies on this topic exhibited limited scientific translational value because of their heterogeneity. The evidence associated with preclinical studies is limited. The role of inflammation in tendon healing is still unclear, though it seems to affect the overall outcome. A thorough understanding of the biochemical mediators of healing and their pathway of pain could be used to target tendinopathy and possibly guide its management. We require further studies with improved designs to effectively evaluate the pathogenesis and progression of tendinopathy to identify cellular and molecular targets to improve outcomes.

Electric Polarization of Soft Biological Tissues Induced by Ultrasound Waves.

Ultrasound irradiation makes it possible to generate alternating electric polarization through the electromechanical coupling of materials. It follows that electromagnetic fields are often emitted to the surrounding environment when materials are acoustically stimulated. We investigate the acoustically stimulated electromagnetic (ASEM) response of soft biological tissues. The ASEM signal is detected through a capacitive resonant antenna tuned to the MHz frequency of the irradiated ultrasound waves. The signal is well explained by the stress-induced polarization, which responds linearly to the applied acoustic stress. Induced polarization is clearly observed in the Achilles tendon, aortic wall, and aortic valve samples, whereas it is small in adipose tissue and myocardium samples, indicating that fibrous tissues exhibit electromechanical coupling.

Systemic inflammatory response to the Radial Pressure Wave Therapy (RPWT) in collagenase-induced Achilles tendinopathy treated with Adipose Derived Stem Cells or Platelet Rich Plasma

Novel tendinopathy treatment protocols should be assessed for safety. The goal of this work was to compare differences in selected systemic inflammatory marker concentrations after two treatment protocols for collagenase induced Achilles tendinopathy in sheep. 14 sheep (aged 5 and 6 years, Polish Mountain Sheep breed, weight 60-70kg) were injected with bacterial collagenase type 1A-S (Clostridium histolyticum, C-5894, Sigma Aldrich, Poznań, Poland) bilaterally to Achilles tendons. Subsequently, the animals were injected with Platelet Rich Plasma (7 sheep) or Adipose Derived Stem Cells (7 sheep) to induced tendinopathy foci. Left limbs of all sheep were additionally treated with Radial Pressure Wave Therapy (RPWT) focused above the tendinopathy origins. Treatment progress was controlled by ultrasound scans, and tendon samples were taken on the 126th day of the experiment. Serum Amyloid A (SAA) concentration showed mild elevation before the experiment (2 sheep from group I, 4 sheep from group II) and two days after the intratendinous growth factors injection ( 4 sheep from group I, 3 sheep from group II) combined with RPWT (mean 22,63 mg/L and 53, 6 mg/L respectively). Haptoglobine (Hp) concentration increased from 0 to 0,01 g/L in 2 animals from group I two days after injection. These values declined to 0 during the course of the treatment. Fibrinogen (Fb) concentrations were within reference levels throughout the research, although mild elevation was observed before the treatment course in 6 sheep from group I and 1 sheep from group II. In conclusion, addition of RPWT to growth factors injections in the treatment of yatrogenic Achilles tendinopathy in sheep did not induce systemic inflammatory response.

Histopathological analysis of the inflammatory response of two invasive techniques in the calcaneal tendon of a mouse

Abstract Background and Aim Percutaneous needle electrolysis (PNE) is a therapeutic tool which has demonstrated its effectiveness of the treatment of tendinopathies and muscle problems. Previous authors have based the therapeutic effect of the same on the ability to provoke an important inflammatory response. However, there is a scarcity of basic research directed at understanding its effects on a cellular and histological level. The aim of this study was to histopathologically compare the inflammatory response provoked by PNE versus dry needling (DN) in a healthy animal model. Material and Methods For the proposed study aim a murine model was used with a total of 18 C57BL/6J mice. All animals received an application of DN in the left common calcaneal tendon, whereas on the right, treatment with PNE was applied (3 impacts of 3mA during 3 seconds). Groups of animals were sacrificed at 3, 7 and 15 days to evaluate the histopathological evolution of the lesions. Samples of the common calcaneal tendon were taken and fixed in commercial formalin at 4% tamponed during 24 hours, processed and included in paraffin blocks. Sections of 3 microns thick were performed which were dyed with hematoxylin-eosin for conventional histopathological examination. Results Dry needling of the common calcaneal tendon induced the presence of an acute inflammatory infiltrate (characterized by the presence of polymorphonuclear neutrophils and macrophages) in the peritenon and adjacent fat tissue which was detectable after the third day, and which was most notable on days 7 and 14. The application of PNE induced a pattern with a similar behavior, however on day 14, the inflammatory infiltrate of PNE was more evident compared with DN. Conclusion The proposed in vivo murine model has been useful for the study of the first phases of the regeneration process induced by both techniques. The histopathological results show that PNE generates a superior stimulus compared to DN on day 14.

Inflammatory response of two invasive techniques in the mouse with collagenase induced tendinopathy

Abstract Background Percutaneous needle electrolysis (PNE) is a physiotherapy technique which has demonstrated its effectiveness for the treatment of tendinopathies and muscle pathologies. All the authors consulted base its therapeutic effect on the capacity to produce an important inflammatory response during the initial phase of the regenerative process. However, presently, the histological effects of the technique on tendinopathies are unknown. The aim of this study was to histologically examine the inflammatory response provoked by the PNE versus dry needling (DN) in mice with collagenase-induced tendinopathy. Material and Methods In order to achieve the proposed aim, a murine model was used with a total of 18 C57BL/6J mice. One week prior to the intervention, collagenase-induced tendinopathy was performed in the common calcaneal tendons of all mice. Once the pathology was established, they received DN in the left common calcaneus tendon, whereas, on the right, they received treatment with PNE. Groups of animals were sacrificed at 3, 7 and 14 days to evaluate the histological evolution of injuries. Samples of the common calcaneal tendon were taken and were later fixed in formalin, processed, and included in paraffin blocks. Sections of 3 microns thick were performed, which were dyed using hematoxylin-eosin for conventional histopathological examination. Results In both groups, tissue damage was observed with collagen fragmentation and the presence of fibroblasts. Dry needling of the common calcaneal tendon induced the presence of an acute inflammatory infiltrate (characterized by the presence of polymorphonuclear neutrophils and macrophages) at the level of the peritenon and adjacent fat tissue which was detectable after day 3, and notable after days 7 and 14. The application of PNE induced a similar effect, although on day 14, the inflammatory infiltrate of PNE was more evident, compared to DN. Conclusion The proposed in vivo murine model has demonstrated to be useful for the study of the evolution of the first phases of the regenerative process induced by both techniques. The histopathological results reveal that PNE generates a pro-inflammatory stimulus which is superior to DN on day 14.

MicroRNA Profiling Reveals Distinct Signatures in Degenerative Rotator Cuff Pathologies.

ABSTRACTMicroRNAs (miRNAs) have emerged as key regulators orchestrating a wide range of inflammatory and fibrotic diseases. However, the role of miRNAs in degenerative shoulder joint disorders is poorly understood. The aim of this explorative case‐control study was to identify pathology‐related, circulating miRNAs in patients with chronic rotator cuff tendinopathy and degenerative rotator cuff tears (RCT). In 2017, 15 patients were prospectively enrolled and assigned to three groups based on the diagnosed pathology: (i) no shoulder pathology, (ii) chronic rotator cuff tendinopathy, and (iii) degenerative RCTs. In total, 14 patients were included. Venous blood samples (“liquid biopsies”) were collected from each patient and serum levels of 187 miRNAs were determined. Subsequently, the change in expression of nine candidate miRNAs was verified in tendon biopsy samples, collected from patients who underwent arthroscopic shoulder surgery between 2015 and 2018. Overall, we identified several miRNAs to be progressively deregulated in sera from patients with either chronic rotator cuff tendinopathy or degenerative RCTs. Importantly, for the several of these miRNAs candidates repression was also evident in tendon biopsies harvested from patients who were treated for a supraspinatus tendon tear. As similar expression profiles were determined for tendon samples, the newly identified systemic miRNA signature has potential as novel diagnostic or prognostic biomarkers for degenerative rotator cuff pathologies. © 2019 The Authors. Journal of Orthopaedic Research ® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. Inc. J Orthop Res 38:202–211, 2020

Detection of the Tendon Properties in Posterior Tibial Tendinopathy in Three-Dimensional Space Using High Resolution Multiphoton and Second Harmonic Generation Imaging

Category:HindfootIntroduction/Purpose:Posterior tibial tendon dysfunction is the most common cause of acquired flat foot deformity in adults, and results in significant morbidity. The exact etiology of this condition is still unknown. Posterior tibial tendon is predominately made up of fibrillar collagens and we hypothesize that their structural properties such as the collagen fiber density, orientation properties and cross-linking density essentially control the biomechanical properties of posterior tibial tendons. In this study, our aim is to visualize and quantitate fibrillar collagen distributions, their organization, cross-link densities and the fiber orientation (using Fourier analysis) in three distinct regions of pathologic posterior tibial tendon human samples namely proximal, middle and distal regions.Methods:After an institutional IRB approval we obtained diseased posterior tibial tendon total excision samples from 10 patients that had reconstructive procedures for posterior tibial tendinopathy at our institution and two fresh non-frozen healthy posterior tibial tendon samples from cadavers were used as the control. This research mainly utilized well established multiphoton microscopy and harmonic generation methodologies which compared proximal, middle and distal 1/3 of the tendon samples; multiphoton microscopy provides a powerful imaging method for evaluation of remodeling of fibrillar collagen structures deep within tissues. Ultra-short IR laser pulses served as an excitation source to produce multiphoton excitation fluorescence (MPEF) from endogenously fluorescent macromolecular systems and to induce highly specific second harmonic generation (SHG) signals from fibrillar collagens. Since MPEF and SHG involve different principles and contrast mechanisms, they were captured simultaneously to provide spectrally and spatially resolved, quantitative imaging of complex structures.Results:We systematically examined the nature of fibrillar collagen remodeling in relatively thick posterior tibial tendon tissues. Representative 3D forward SHG (FSHG), backward SHG (BSHG) and auto-fluorescence (MPEF) images originating from fibrillar collagen matrix from relatively thick (˜50 microns) posterior tibial tendon sections of three different regions namely proximal, middle and distal regions are shown in Figure 1. Computed Orientation Index values obtained from Fourier analysis show statistically significant differences particularly between proximal and middle regions (decreased orientation of collagen fibers in the middle region, p<0.0001). The cross-linking densities determined from the ratio of auto-fluorescence (MPEF) to BSHG again show differences particularly between proximal and middle regions (increased cross-linking in the middle region, p<0.01).Conclusion:The multiphoton and harmonic generation microscopy can be a powerful high resolution imaging method requiring minimal sample preparation that can provide structural information about spatially and spectrally resolved fibrillar collagens in three different posterior tibial tendon tendon regions. We found that middle third of the pathologic tendons show increased cross-linking and decreased orientation ratio of the collagen fibers which can provide insight into the regional based collagen remodeling and improved understanding of earliest stages of tendon destruction that could lead to improvements in the treatment of this condition.

Histotripsy in collagenous tendons.

Tendon injuries comprise 45% of the 66 million musculoskeletal injuries each year with annual costs of $114 billion. Conservative therapies to treat injured tendon produce mixed success rates. Histotripsy is a high intensity focused ultrasound modality that creates and oscillates bubbles to fractionate soft tissues in a well-defined focal volume; however, highly collagenous tissues like tendon have proven resistant to histotripsy. The goal here is to explore acoustic parameters for mechanical fractionation of tendons. Large animal Achilles tendons were exposed to HIFU at 1.07-3.68 MHz with 0.005-20 ms pulses repeated at 1-1000 Hz for 15-60 s with acoustic pressures up to p+ = 97 MPa, p- = 27 MPa. A Verasonics research ultrasound imaging system and ATL L7-4 transducer was used to monitor bubble activity during exposure. Tendon samples were fixated and stained with Hematoxylin and Eosin (H&E) for cellular morphology analysis and alpha-nicotinamide dinucleotide diaphorase (αNADH-d) for enzymatic activity analysis. Results showed successful bubble creation in the focal region; however, only 1/90 samples showed focal coagulative necrosis histologically. Future work involves an evaluation of whether bubbles are of insufficient size or collapse strength to mechanically fractionate tendon. [Work supported by Penn State Seed Grant, NIH EB027886, and NSF DGE1255832].

Retinoic Acid Promotes Retinoic Acid Signaling by Suppression of Pitx1 In Tendon Cells: A Possible Mechanism of a Clubfoot-Like Phenotype Induced by Retinoic Acid.

BackgroundThe pathogenesis of idiopathic congenital clubfoot (CCF) is unknown. Although some familial patients have Pitx1 mutations, and the Pitx1+/− genotype causes a clubfoot-like phenotype in mice, the mechanism of Pitx1-induced CCF is unknown.Material/MethodsWe used tibialis anterior tendon samples to detect the expression of Pitx1 in idiopathic and neurogenic clubfoot patients. After obtaining Sprague-Dawley (SD) rat Achilles tendon cells, the expression of Pitx1 was knocked down by SiRNA. After 48 h of culture, mass spectrometry was used to quantitatively analyze proteins. Then, Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to assess the downstream pathway of PITX1. The relationship between Pitx1 and the promoter region of deacetylase 1 (Sirtuin-1 and Sirt1) was examined by luciferase and ChIP assays.ResultsWe found that Pitx1 expression in the tendon samples of idiopathic CCF patients was downregulated. Mass spectrometry analysis revealed that the inhibition of Pitx1 induced the downregulation of Sirt1 expression in tendon cells. Luciferase and ChIP assays confirmed that Pitx1 binds to the promoter region of SIRT1 and promotes Sirt1 gene transcription. Further results showed that, after the inhibition of Pitx1 in tendon cells, CRABP2 acetylation increased, the nuclear import of CRABP2 was enhanced, and the expression of RARβ2 increased. After the inhibition of Pitx1, RARβ2 expression was further increased by RA treatment in tendon cells. In the presence of retinoic acid, the expression of Pitx1 was inhibited in tendon cells.ConclusionsPitx1 binds to the promoter region of SIRT1 and promotes the transcription of SIRT1. Positive feedback occurs between RA signaling and Pitx1.

Risk Factors for Rotator Cuff Disease: An Experimental Study on Intact Human Subscapularis Tendons.

ABSTRACTAlthough several studies revealed a multifactorial pathogenesis of degenerative rotator cuff disorders, the impact and interaction of extrinsic variables is still poorly understood. Thus, this study aimed at uncovering the effect of patient‐ and pathology‐specific risk factors that may contribute to degeneration of the rotator cuff tendons. Between 2015 and 2018, 54 patients who underwent arthroscopic shoulder surgery at three specialized shoulder clinics were prospectively included. Using tendon samples harvested from the macroscopically intact subscapularis (SSC) tendon, targeted messenger RNA expression profile analysis was performed in the first cohort (n = 38). Furthermore, histological analyses were conducted on tendon tissue samples obtained from a second cohort (n = 16). Overall, both study cohorts were comparable concerning patient demographics. Results were then analyzed with respect to specific extrinsic factors, such as patient age, body mass index, current as well as previous professions and sport activities, smoking habit, and systemic metabolic diseases. While patient age, sports‐activity level, and preexisting rotator cuff lesions were considered to contribute most strongly to tendinopathogenesis, no further coherences were found. With regards to gene expression analysis, change in expression correlated most strongly with patient age and severity of the rotator cuff pathology. Further, chronic disorders increased overall gene expression variation. Taken together, our study provides further evidence that tendon degeneration is the consequence of a multifactorial process and pathological changes of the supraspinatus tendon affect the quality of SSC tendon and most likely vice versa. Therefore, the rotator cuff tendons need to be considered as a unit when managing rotator cuff pathologies. © 2019 The Authors. Journal of Orthopaedic Research ® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society J Orthop Res 38:182–191, 2020

Does PRP Improve the Tendon Gap Healing?

Background: The tendon repairs slowly. Platelets’ alpha granules contain polypeptide growth factors that stimulate proliferation of normal connective tissue cells. The acute phase of inflammation is necessary for healing progress and fibroplasia. Platelet growth factors initiate and accelerate the inflammatory response by the host. Objectives: This study aimed to investigate if platelet-rich plasma (PRP) helps tendon gap healing. Methods: Aseptic surgery was performed on 24 mature guinea pigs in four groups to excise a 7-mm piece of the deep digital flexor (DDF) tendon of the right hind leg. In groups 1 and 2, the two ends of the severed tendon were sutured in the fascia conduit; group 2 received PRP injection into the conduit. In groups 3 and 4, the two ends of the severed tendon were sutured in a silicone tube conduit, and group 4 received PRP injection. After 42 days, the animals were euthanized and tendon samples were collected for further study. Results: The histopathological and stereological data showed that inflammation was far less in PRP-treated groups as they showed more fibroblastic proliferation. The synergistic effects of silicone tube and PRP injection showed the least inflammatory response. The diameter of collagen bundles and their volume were higher in the groups which received PRP in the silicone conduit. Conclusions: The present study found that PRP improved healing of tendon injury and silicone conduit served as good surgical technique with synergistic effect beside PRP.

Investigating circadian clock gene expression in human tendon biopsies from acute exercise and immobilization studies.

The discovery of musculoskeletal tissues, including muscle, tendons, and cartilage, as peripheral circadian clocks strongly implicates their role in tissue-specific homeostasis. Age-related dampening and misalignment of the tendon circadian rhythm and its outputs may be responsible for the decline in tendon homeostasis. It is unknown which entrainment signals are responsible for the synchronization of the tendon clock to the light-dark cycle. We sought to examine any changes in the expression levels of core clock genes (BMAL1, CLOCK, PER2, CRY1, and NR1D1) in healthy human patellar tendon biopsies obtained from three different intervention studies: increased physical activity (leg kicks for 1h) in young, reduced activity (2weeks immobilization of one leg) in young, and in old tendons. The expression level of clock genes in human tendon in vivo was very low and a high variation between individuals was found. We were thus unable to detect any differences in core clock gene expression neither after acute exercise nor immobilization. We are unable to find evidence for an effect of exercise or immobilization on circadian clock gene expression in human tendon samples.

Characterization of Tendon-Specific Markers in Various Human Tissues, Tenocytes and Mesenchymal Stem Cells.

Unlike bone, cartilage, or muscle, tendon-specific markers are not well established. The purpose of the study was to investigate expression pattern and level of 6 well-known tendon-specific markers, in various human musculoskeletal tissues, tenocytes, and mesenchymal stem cells (MSCs). Musculoskeletal tissue samples of tendon, bone, cartilage, nerve, muscle, and fat were obtained from patients undergoing orthopedic surgery. Tenocytes, MSCs from bone marrow, adipose tissue, and umbilical cord were isolated from each tissue and cultured. Six tendon-specific markers, scleraxis (Scx), tenomodulin (TNMD), thrombospondin-4 (TSP-4), tenascin-C (TNC), type I collagen (Col I), and type III collagen (Col III) were investigated in tendon tissue, tenocytes, and MSCs. mRNA levels of 6 tendon-specific markers were significantly higher in tendon tissue that in other connective tissues levels of Scx, TNMD, TSP-4, and Col III immediately decreased after plating tenocytes in culture dishes whereas those of TNC and Col I did not. In comparison with tendon tissue, mRNA levels pattern of Scx, TNMD, and TSP-4 in tenocytes were significantly higher than that in MSCs, but lower than in tendon tissue whereas expression pattern of TNC, Col I and III showed different pattern with each other. This study demonstrated that 6 commonly used tendon-specific markers were mainly expressed in tendon tissue, but that expression level and pattern of the tendon-specific markers with respect to kinds of tissues, culture duration of tenocytes and sources of MSCs.

Combined ascorbic acid and T3 produce better healing compared to bone marrow mesenchymal stem cells in an Achilles tendon injury rat model: a proof of concept study

BackgroundThis pilot study aimed to ascertain whether the local application of ascorbic acid (AA), of T3, and of rat (r) bone marrow mesenchymal stem cells (BMSCs), alone or in all possible combinations, promoted healing after an Achilles tendon injury in a rat model.MethodsAn Achilles tendon defect was produced in 24 6–8-week-old male inbred Lewis rats. The animals were then randomly divided into eight groups of three rats each. The tendon defect was filled with 50 μL of phosphate-buffered saline (PBS) containing (1) 50 μg/mL AA (AA group), (2) 10−7 M T3 (T3 group), (3) 4 × 106 rBMSCs (rBMSC group), (4) 50 μg/mL AA + 10−7 M T3 (AA + T3 group), (5) 4 × 106 rBMSCs + 50 μg/mL AA (rBMSC + AA group), (6) 4 × 106 rBMSCs + 10−7 M T3 (rBMSC + T3 group), (7) 4 × 106 rBMSCS + 50 μg/mL AA + 10−7 M T3 (rBMSC + AA + T3 group), and (8) PBS only (control group: CTRL). All treatments were administered by local injection immediately after the tendons had been damaged; additionally, AA was injected also on the second and fourth day from the first injection (for groups 1, 4, 5, and 7), and T3 was injected again every day for 4 days (for groups 2, 4, 6, and 7). At 30 days from initial treatment, tendon samples were harvested, and the quality of tendon repair was evaluated using histological and histomorphological analysis. The structure and morphology of the injured Achilles tendons were evaluated using the modified Svensson, Soslowsky, and Cook score, and the collagen type I and III ratio was calculated.ResultsThe group treated with AA combined with T3 displayed the lowest Svensson, Soslowsky, and Cook total score value of all tissue sections at histopathological examination, with fiber structure close to regular orientation, normal-like tendon vasculature, and no cartilage formation. AA + T3 also showed the highest collagen I and the lowest collagen III values compared to all other treatments including the CTRL.ConclusionThere are potential benefits using a combination of AA and T3 to accelerate tendon healing.

Bacterial contamination rate and associated factors during bone and tendon allograft procurement from Spanish donors: exploring the contamination patterns

Bacterial contamination rate and associated factors during bone and tendon allograft procurement from Spanish donors: exploring the contamination patterns

Pilot experimental study on amniotic epithelial mesenchymal cell transplantation in natural occurring tendinopathy in horses. Ultrasonographic and histological comparison

amnion-derived stem cells are considered a promising alternative source for tendon tissue regeneration. aims of this paper were to illustrate the ultrasound and histological outcomes following the treatment of acute and chronic superficial digital flexor tendon spontaneous lesions in horses with ovine amniotic epithelial cells xenotransplantation. six adult horses suffering from unilateral acute (4 cases) and chronic (2 cases) tendinopathy (clinical and ultrasound diagnosis) were enrolled. At baseline, ovine amniotic epithelial cells were grafted, in sterile conditions and under ultra-sound control, into the most damaged area. Ultra-sound controls were performed at 30, 60, 90, 120, 150 and 180 days after cells implantation; after horse euthanasia (180 days) tendon samples were collected and submitted to histological examination (cellularity, extracellular matrix fiber organization, blood vessels). at baseline, in the acute cases, the ultra-sound exam showed a focal, dis-homogeneous, hypo-echoic area into the superficial digital flexor tendon, with loss of the normal fibrillar pattern, while in the chronic cases the damaged tendon area appeared thickened and completely hyper-echoic. At the final follow-up tendon echotexture was more regular, the cross-sectional area similar to the contra-lateral limb, and the collagen fibers were oriented in parallel to the longitudinal axis of the tendon both in the acute and chronic cases, suggesting a positive healing response. These findings were supported by the histological analyses which showed an almost complete restoration of normal tendon architecture with an optimal alignment of tendon fibers. the present pilot study supports the hypothesis that amniotic epithelial cells are provided of an excellent healing potential and shows a very good correlation between the ultrasound findings and the histologic features.

Cigarette smoking intensifies tendinopathy of the LHBT. A microscopic study after arthroscopic treatment.

Smoking has adamaging effect on the musculoskeletal system, which was presented by authors in the rotator cuff and Achilles tendons studies; however, there are alack of data about the effect of smoking on disorders of the long head of the biceps tendon (LHBT), particularly at the microscopic level. The purpose of this study was to investigate the effect of the tobacco smoking on the histopathologic alterations of the LHBT. Thirty-six patients with preoperatively diagnosed tendinopathy of the LHBT were referred to the Orthopaedics Department. All patients underwent arthroscopic treatment with further macroscopic and microscopic evaluation of biceps tendon samples. The active and former smokers were characterised by more advanced degenerative process of the tendinous tissue; moreover, it was intensified in the group of former smokers. Subjects who smoke more than 20 cigarettes per day also had more advanced microscopic alterations. The most severe microscopic alterations occurred in the former smokers who used tobacco for more than 20 years. However, the non-smokers group revealed moderate degeneration in all LHBT samples. Tobacco smoking is an important risk factor of the LHBT disease, which essentially intensifies the degeneration of the tendinous tissue.