Mechanical overload-induced release of extracellular mitochondrial particles from tendon cells leads to inflammation in tendinopathy

Tendinopathy is one of the most common musculoskeletal diseases, and mechanical overload is considered its primary cause. However, the underlying mechanism through which mechanical overload induces tendinopathy has not been determined. In this study, we identified for the first time that tendon cells can release extracellular mitochondria (ExtraMito) particles, a subtype of medium extracellular particles (mEPs), into the environment through a process regulated by mechanical loading. RNA sequencing systematically revealed that oxygen-related reactions, extracellular particles, and inflammation were present in diseased human tendons, suggesting that these factors play a role in the pathogenesis of tendinopathy. We simulated the disease condition by imposing a 9% strain overload on three-dimensional mouse tendon constructs in our cyclic uniaxial stretching bioreactor. The three-dimensional mouse tendon constructs under normal loading with 6% strain exhibited an extended mitochondrial network, as observed through live-cell confocal laser scanning microscopy. In contrast, mechanical overload led to a fragmented mitochondrial network. Our microscopic and immunoblot results demonstrated that mechanical loading induced tendon cells to release ExtraMito particles. Furthermore, we showed that mEPs released from tendon cells overloaded with a 9% strain (mEP9%) induced macrophage chemotaxis and increased the production of proinflammatory cytokines, including IL-6, CXCL1, and IL-18, from macrophages compared to mEP0%, mEP3%, and mEP6%. Partial depletion of the ExtraMito particles from mEP9% by magnetic-activated cell sorting significantly reduced macrophage chemotaxis. N-acetyl-L-cysteine treatment preserved the mitochondrial network in overloaded tendon cells, diminishing overload-induced macrophage chemotaxis toward mEP9%. These findings revealed a novel mechanism of tendinopathy; in an overloaded environment, ExtraMito particles convey mechanical response signals from tendon cells to the immune microenvironment, culminating in tendinopathy.

[Three decades of progress in China's laparoscopic colorectal surgery techniques]

Laparoscopic colorectal surgery has been carried out in China for more than 30 years and has experienced a three-stage high-speed development of "exploring and designing,optimising and standardising, perfecting and re-innovating" at the technical level. Based on the support and assistance of laparoscopic technology, colorectal surgery has made rapid progress in sub-microscopic anatomy, surgical procedures, surgical concepts, instruments and equipment. Nowadays, the technology and efficacy of laparoscopic colorectal surgery have gradually reached the ceiling, and in view of the existing pain points and the future direction of development, where will we go? This article summarised the past three decades of experience and consolidate the results to guide the future practice and the way forward.

[Doctors' original intentionality in adherence to non-invasive diagnoses benefits MAFLD patients]

Precisely diagnosing metabolic dysfunction-associated fatty liver disease (MAFLD) and its severity degree can effectively delay disease progression and have important guiding values for treatment. In recent years, research on non-invasive diagnosis of metabolic dysfunction-associated fatty liver disease has made great progress, suggesting that we should not only give full play advantage to professional personnel in the field of liver disease but also actively cooperate with personnel in other fields to explore different high-performance non-invasive diagnostic methods to achieve early detection, diagnosis, and treatment.

[Clinical characteristics and placental pathology analysis of 14 cases of pregnancy with aortic dissection/aortic aneurysm]

Objective: To investigate the pathological changes of placenta in pregnant women with aortic dissection/aneurysm and their relationship with clinical features. Methods: The placental samples of 14 pregnant women with aortic dissection/aneurysm diagnosed from January 2012 to October 2021 and 10 normal placental samples of pregnant women from January 2021 to December 2021 at Beijing Anzhen Hospital Affiliated to Capital Medical University, Beijing, China were selected. Routine H&E staining and immunohistochemistry were used to analyze the histological features under light microscope. The clinical data were also analyzed. Results: The age of 14 pregnant patients with aortic dissection/aneurysm for placental examination ranged from 22 to 38 years (median, 28 years). The gestational ages ranged from 22 to 39 weeks (median, 34 weeks). The pregnancy of second trimester was noted in 2 cases, and the third trimester in 12 cases. All cases were singleton pregnancy. Seven cases were Stanford type A aortic dissection, 6 cases were Stanford type B aortic dissection, and one case was aortic root aneurysm. Four of the pregnant women underwent aortic dissection surgery after caesarean section, three underwent caesarean section after aortic dissection surgery, and seven underwent both caesarean section and aortic dissection procedures. Among the newborns, 2 cases were full-term birth, and 12 cases were premature birth. Twelve cases had alive newborns, and 2 cases stillbirths. Fetal/placental weight ratio (FPR)<10th percentile was in 5 cases and FPR>90th percentile in one case. Compared with the normal group, accelerated villus maturation and distal villus dysplasia were more frequently found in pregnancy with aortic dissection group (P<0.05). There was no significant difference in villi infarction and decidua vascular lesions between the two groups (P>0.05), nor was there correlation between the type of aortic dissection and distal villus dysplasia and accelerated villus maturation of placentas (P>0.05). The number of villous interstitial blood vessels in the placentas of pregnancy with aortic dissection group was significantly fewer than that in the normal control group (P<0.01). Conclusions: There are considerable pathological changes in the placentas of pregnant women with aortic dissection/aneurysm. The main histological features are accelerated villus maturation and distal villus dysplasia, which are manifestations of villous ischemia and hypoxia, and also a part of the placental pathological manifestations of maternal vascular dysperfusion.

The burden of end-stage osteoarthritis in Australia: a population-based study on the incidence of total knee replacement attributable to overweight/obesity

OBJECTIVES

To determine the risk of total knee replacement (TKR) for primary osteoarthritis (OA) associated with overweight/obesity in the Australian population.

METHODS

This population-based study analyzed 191,723 cases of TKR collected by the Australian Orthopaedic Association National Joint Registry and population data from the Australian Bureau of Statistics. The time-trend change in incidence of TKR relating to BMI was assessed between 2015 and 2018. The influence of obesity on the incidence of TKR in different age and gender groups was determined. The population attributable fraction (PAF) was then calculated to estimate the effect of obesity reduction on TKR incidence.

RESULTS

The greatest increase in incidence of TKR was seen in patients from obese class III. The incidence rate ratio for having a TKR for obesity class III was 28.683 at those aged 18-54 years but was 2.029 at those aged >75 years. Females in obesity class III were 1.7 times more likely to undergo TKR compared to similarly classified males. The PAFs of TKR associated with overweight or obesity was 35%, estimating 14,287 cases of TKR attributable to obesity in 2018. The proportion of TKRs could be reduced by 20% if overweight and obese population move down one category.

CONCLUSIONS

Obesity has resulted in a significant increase in the incidence of TKR in the youngest population in Australia. The impact of obesity is greatest in the young and the female population. Effective strategies to reduce the national obese population could potentially reduce 35% of the TKR, with over 10,000 cases being avoided.

[Multidimensional thinking in the era of gastrointestinal minimally invasive surgery]

Minimally invasive surgery represented by laparoscopic technique has been carried out in China for more than 30 years. Gastrointestinal minimally invasive surgery has been widely recognized and popularized. Today, when the development of minimally invasive technology has reached the ceiling, the authors, who have experienced the innovation of minimally invasive gastrointestinal surgery for more than 30 years, review the gradual, unpredictable but inevitable characteristics of the innovation and development of minimally invasive surgery; figure out that standardized promotion and systematic training are the main reasons for the success of minimally invasive surgery in gastrointestinal surgery; realize that the application and promotion of new medical technology are inseparable from the support of solid clinical and basic evidence; recognize that the re-innovation after the popularization and standardization of gastrointestinal minimally invasive surgery and how to avoid involution are the driving force to seize the development momentum of minimally invasive technology. We make a multidimensional thinking on the development of gastrointestinal minimally invasive surgery, and objectively analyze its development track, in order to calmly rise to the challenges of future technological development.

[Clinicopathological characteristics and molecular alterations of primary cardiac leiomyosarcoma: report of five cases]

Objective: To investigate the clinical, pathologic and radiologic features and molecular alterations in patients with primary cardiac leiomyosarcoma (PCLMS). Methods: Five cases of PCLMS were collected in Beijing Anzhen Hospital from January 2016 to December 2020. The clinical, pathologic and radiologic data, and molecular alterations were analyzed, and the patients were followed up. Results: All five patients were female, and had no history of leiomyosarcoma in other parts of the body. The age of patients ranged from 37 to 62 years (median 47 years). The main clinical symptoms were chest pain and dyspnea, one also presented with palpitation and lower limb weakness and one with dizziness. Two tumors were located in the left atrium, two in the right atrium, and one in the right ventricle, and they maximal diameter ranged from 2.5 to 14.0 cm (mean 6.2 cm). The neoplasms presented as medium-echo masses with a broad base in the echocardiography, and as a low-density, solid mass when detected by contrast-enhanced CT. Histologically, two tumors were well-differentiated and three were moderately and poorly differentiated, and two included extensive, loose myxoid stroma. Immunohistochemical staining showed that PCLMS was positive for SMA, desmin, MDM2, and epidermal growth factor receptor. Fluorescence in situ hybridization showed ALK gene rearrangement in two cases, and COL1A1-PDGFB fusion in three cases. All cases received surgical excision and two cases received chemotherapy. Three patients died within 0-11 months (mean survival of 7.7 months) and two patients were alive. Conclusions: PCLMS is a malignant tumor with a high recurrence rate and poor prognosis. These cases may provide useful information to improve the diagnosis and management of PCLMS.

Load-induced regulation of tendon homeostasis by SPARC, a genetic predisposition factor for tendon and ligament injuries

Tendons and tendon interfaces have a very limited regenerative capacity, rendering their injuries clinically challenging to resolve. Tendons sense muscle-mediated load; however, our knowledge on how loading affects tendon structure and functional adaption remains fragmentary. Here, we provide evidence that the matricellular protein secreted protein acidic and rich in cysteine (SPARC) is critically involved in the mechanobiology of tendons and is required for tissue maturation, homeostasis, and enthesis development. We show that tendon loading at the early postnatal stage leads to tissue hypotrophy and impaired maturation of Achilles tendon enthesis in Sparc ^-/- mice. Treadmill training revealed a higher prevalence of spontaneous tendon ruptures and a net catabolic adaptation in Sparc ^-/- mice. Tendon hypoplasia was attenuated in Sparc ^-/- mice in response to muscle unloading with botulinum toxin A. In vitro culture of Sparc ^-/- three-dimensional tendon constructs showed load-dependent impairment of ribosomal S6 kinase activation, resulting in reduced type I collagen synthesis. Further, functional calcium imaging revealed that lower stresses were required to trigger mechanically induced responses in Sparc ^-/- tendon fascicles. To underscore the clinical relevance of the findings, we further demonstrate that a missense mutation (p.Cys130Gln) in the follistatin-like domain of SPARC, which causes impaired protein secretion and type I collagen fibrillogenesis, is associated with tendon and ligament injuries in patients. Together, our results demonstrate that SPARC is a key extracellular matrix protein essential for load-induced tendon tissue maturation and homeostasis.

[Progress of researches on the involvement of indoleamine 2, 3-dioxygenase in regulation of parasite-host immune interactions]

Indoleamine 2, 3-dioxygenase (IDO) is an important immunoregulatory enzyme, which mediates immune effects by depleting tryptophan and producing multiple metabolites. Recently, the studies on the immune function of IDO have been mostly restricted in tumors and autoimmune diseases. Nevertheless, there are few studies pertaining to the role of IDO in parasitic diseases, notably in parasite-host immune interactions. This review mainly describes IDO-mediated immunoregulatory effects and its regulation of parasite-host interactions, so as to provide insights into the development of immune intervention schemes against parasitic diseases.

Reduction of mechanical loading in tendons induces heterotopic ossification and activation of the β-catenin signaling pathway

Background

Tendons are the force transferring tissue that enable joint movement. Excessive mechanical loading is commonly considered as a primary factor causing tendinopathy, however, an increasing body of evidence supports the hypothesis that overloading creates microdamage of collagen fibers resulting in a localized decreased loading on the cell population within the damaged site. Heterotopic ossification is a complication of late stage tendinopathy, which can significantly affect the mechanical properties and homeostasis of the tendon. Here, we the examine the effect of mechanical underloading on tendon ossification and investigate its underlying molecular mechanism.

Method

Rabbit Achilles tendons were dissected and cultured in an underloading environment (3% cyclic tensile stain,0.25 ​Hz, 8 ​h/day) for either 10, 15 or 20 days. Using isolated tendon-derived stem cells (TDSCs) 3D constructs were generated, cultured and subjected to an underloading environment for 6 days. Histological assessments were performed to evaluate the structure of the 3D constructs; qPCR and immunohistochemistry were employed to study TDSC differentiation and the β-catenin signal pathway was investigated by Western blotting. Mechanical testing was used to determine ability of the tendon to withstand force generation.

Result

Tendons cultured for extended times in an environment of underloading showed progressive heterotopic ossification and a reduction in biomechanical strength. qPCR revealed that 3D TDSCs constructs cultured in an underloading environment exhibited increased expression of several osteogenic genes: these include RUNX2, ALP and osteocalcin in comparison to tenogenic differentiation markers (scleraxis and tenomodulin). Immunohistochemical analysis further confirmed high osteocalcin production in 3D TDSCs constructs subject to underloading. Western blotting of TDSC constructs revealed that β-catenin accumulation and translocation were associated with an increase in phosphorylation at Ser552 and decrease phosphorylation at Ser33.

Conclusion

These findings unveil a potential mechanism for heterotopic ossification in tendinopathy due to the underloading of TDSCs at the damage sites, and also that β-catenin could be a potential target for treating heterotopic ossification in tendons.

The Translational potential

Tendon heterotopic ossification detrimentally affect quality of life especially for those who has atheletic career. This study reveals the possible mechanism of heterotpic ossification in tendon related to mechanical loading. This study provided the possible to develop a mechanical stimulation protocol for preventive and therapeutic purpose for tendon heterotopic ossification.

[The role of macrophage polarization in parasitic infections: a review]

Macrophages are important members of innate immunity and play an extremely important role in the host defense against pathogenic infections, tumors, and allergic diseases. Macrophages have a high degree of plasticity, and may be polarized into classical activated macrophages (M1 macrophages) and alternative activated macrophages (M2 macrophages) under the stimulation of different environments. M1 macrophages are found to promote inflammatory responses, which facilitates the clearance of pathogens, while M2 macrophages may inhibit inflammatory responses, which facilitates the survival and reproduction of pathogens. This review summarizes the role of macrophage polarization in parasitic infections, so as to provide insights into the prevention and treatment of parasitic diseases.

[Scientific and technological innovation and achievement transformation promote the medical development]

With the worldwide adoption of minimally invasive surgery, innovation again becomes the theme. In the past hundred years, molecular biology technology, minimally invasive surgery technology, pharmaceutical research and therapies have been constantly innovated to promote the development of medicine. As the subject of medical innovation, the innovative idea from medical staff is also very important. For surgeons, the invention and improvement of a new operation or surgical instrument directly depends on curiosity and exploration. Whether a novel idea or technology can be transformed and used in clinical practice depends on its commercial prospects and the adjustment of macro health policies. The protection of intellectual property and appropriate distribution of interests are the key to ensure sustainable innovation. We should put scientific and technological innovation and achievement transformation in the important position of the "healthy China" strategy, take scientific and technological innovation as the basis and achievements transformation as the means, promote the development of China's health protection, implement the healthy China strategy, and make our own contribution to provide people with all-round health services.

[Screening and bioinformatic analysis of trehalase in Thelazia callipaeda]

OBJECTIVE

To characterize the trehalase gene in Thelazia callipaeda through screening the annotated data of the T. callipaeda genome, and to investigate the biological characteristics of the trehalase gene-coding protein.

METHODS

The trehalase gene was screened from the T. callipaeda genome and subjected to validation by using a PCR assay. The structural features of the coding protein were analyzed with bioinformatics tools, including hydrophobicity, transmembrane region, signal peptides, conserved domains, as well as the secondary and tertiary structures and the antigen epitope. Homology analysis of the amino acid sequences was performed, and the phylogenetic tree was built by the MEGA X software. In addition, the protein-protein interaction network was deduced from the STRING database.

RESULTS

The sequence of the trehalase gene with the complete CDS region was obtained from T. callipaeda genome, which had a length of 1 638 bp and encoded 545 amino acids. The encoded protein was predicted to have a molecular weight of 63 478.48 ku and be a secretory protein. The 5' domain of the encoded protein contained a signal peptide without transmembrane regions, and was predicted to contain 7 antigen epitopes. Based on the protein-protein interaction network of nematodes in the STRING database, the protein-protein interaction network of the trehalase gene of T. callipaeda was deduced, and 27 interactions covering 10 genes were identified.

CONCLUSIONS

A trehalase gene is successfully identified in T. callipaeda genome and its coding protein receives a bioinformatics analysis, which provides insights into the research on the biological functions of the protein and the screening of vaccine candidates for thelaziasis callipaeda.

MicroRNA-142-3p suppresses cell proliferation and migration in bladder cancer via Rac1

Expression of microRNA(miR)-142-3p has been implicated to be associated with several cancers, whereas its function in bladder cancer (BC) remains unknown. The present study aimed to explore the correlation between the expression of miR-142-3p and the proliferation, migration and invasion of bladder cancer cells by activating Rac1. qRT-PCR was used to measure the expression of miR-142- 3p in bladder cancer tissues and cell lines. RNA transfection was used to silence and accelerate the expression of miR-142-3p in bladder cancer cells. CCK-8 and trans-well assays were used to detect the proliferation, migration and invasion of cells before and after RNA transfection. The direct interaction between Rac1 and miR-142-3p was demonstrated by a dual luciferase reporter assay. qRT-PCR and Western blot assays were used to detect the expression changes in Rac1 before and after transfection. The results showed that miR-142-3p in bladder cancer tissues was significantly lower than that in adjacent tissues and lower than that in HT1376 and T-24 cells but higher than that in T5637 and BIU- 87 cells. Additionally, upregulating miR-142-3p expression not only inhibits the proliferation of SV-HUC-1 and BIU-87 cells but also inhibits migration and invasion, and downregulating miR-142-3p expression showed the opposite results. The expression of Rac1 was promoted after stimulating miR- 142-3p expression, but was inhibited after silencing miR-142-3p expression. In conclusion, miR-142-3p affects the proliferation, migration and invasion of bladder cancer cells by regulating Rac1.

Endoplasmic reticulum mediates mitochondrial transfer within the osteocyte dendritic network

Mitochondrial transfer plays a crucial role in the regulation of tissue homeostasis and resistance to cancer chemotherapy. Osteocytes have interconnecting dendritic networks and are a model to investigate its mechanism. We have demonstrated, in primary murine osteocytes with photoactivatable mitochondria (PhAM)^floxed and in MLO-Y4 cells, mitochondrial transfer in the dendritic networks visualized by high-resolution confocal imaging. Normal osteocytes transferred mitochondria to adjacent metabolically stressed osteocytes and restored their metabolic function. The coordinated movement and transfer of mitochondria within the dendritic network rely on contact between the endoplasmic reticulum (ER) and mitochondria. Mitofusin 2 (Mfn2), a GTPase that tethers ER to mitochondria, predominantly mediates the transfer. A decline in Mfn2 expression with age occurs concomitantly with both impaired mitochondrial distribution and transfer in the osteocyte dendritic network. These data show a previously unknown function of ER-mitochondrial contact in mediating mitochondrial transfer and provide a mechanism to explain the homeostasis of osteocytes.

[Laparoscopic peritoneal dialysis catheter implantation in peritoneal chemotherapy for gastric cancer with peritoneal metastasis]

Objective: To investigate the clinical value of laparoscopic peritoneal dialysis catheter implantation in peritoneal chemotherapy for gastric cancer with peritoneal metastasis. Methods: From January 2019 to June 2019, the clinical data of 6 patients diagnosed as gastric cancer with peritoneal metastasis were retrospectively analyzed in the Gastrointestinal Surgery Department of Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine. Five were male and 1 was female. The median age was 69.5 (28-77) years. The median body mass index (BMI) was 22.8 (19.6-23.5). All procedures were performed under general anesthesia with endotracheal intubation. The patient's body position and facility layout in the operating room were consistent with those of laparoscopic gastrectomy. The operator's position: the main surgeon was located on the right side of the patient, the first assistant stood on the left side of the patient, and the scopist stood between the patient's legs. Surgical procedure: (1) trocar location: three abdominal trocars was adopted, with one 12 mm umbilical port for the 30° laparoscope (point A). Location of the other two trocars was dependent on the procedure of exploration or biopsy as well as the two polyester cuff position of the peritoneal dialysis catheter: Usually one 5 mm port in the anterior midline 5 cm inferior to the umbilicus point was selected as point B to ensure that the distal end of the catheter could reach the Douglas pouch. The other 5 mm port was located in the right lower quadrant lateral to the umbilicus to establish the subcutaneous tunnel tract, and the proximal cuff was situated 2 cm away from the desired exit site (point C).(2) exploration of the abdominal cavity: a 30° laparoscope was inserted from 12 mm trocar below the umbilicus to explore the entire peritoneal cavity. The uterus and adnexa should be explored additionally for women. Once peritoneal metastasis was investigated and identified, primary laparoscopic peritoneal dialysis catheter implantation was performed so as to facilitate subsequent peritoneal chemotherapy. Ascites were collected for cytology in patients with ascites. (3) peritoneal dialysis catheter placement: the peritoneal dialysis catheter was introduced into the abdominal cavity from point A. Under the direct vision of laparoscopy, 2-0 absorbable ligature was reserved at the expected fixation point of the proximal cuff (point B) for the final knot closure. Non-traumatic graspers were used to pull the distal cuff of peritoneal dialysis catheter out of the abdominal cavity through point B. The 5-mm trocar was removed simultaneously, and the distal cuff was fixed between bilateral rectus sheaths at the anterior midline port site preperitoneally. To prevent subsequent ascites and chemotherapy fluid extravasation, the reserved crocheted wire was knotted. From point C the subcutaneous tunnel tract was created before the peritoneal steath towards the port site lateral to the umbilicus. Satisfactory catheter irrigation and outflow were then confirmed. Chemotherapy regimen after peritoneal dialysis catheterization: all patients began intraperitoneal chemotherapy on the second day after surgery. On the 1st and 8th day of each 3-weeks cycle, paclitaxel (20 mg/m(2)) was administered through peritoneal dialysis catheter, and paclitaxel (50 mg/m(2)) was injected intravenously. Meanwhile, S-1 was orally administered twice daily at a dose of 80 mg·m(-2)·d(-1) for 14 consecutive days followed by 7-days rest. To observe the patients' intraoperative and postoperative conditions. Results: All the procedures were performed successfully without intraoperative complications or conversion to laparotomy. No 30 day postoperative complications were observed. The median operative time was 33.5 (23-38) min. The median time to first flatus was 1(1-2) days, and the median postoperative hospital stay was 3 (3-4) days, without short-term complications within 30 days postoperatively. The last follow-up was up to July 10, 2019, and the patients were followed for 4(1-6) months. No ascites extravasation was observed and no death occurred in the 6 patients. There was no catheter obstruction or peritoneal fluid extravasation during and after chemotherapy. Conclusion: Laparoscopic peritoneal dialysis catheter implantation was safe and feasible for patients with peritoneal metastasis of gastric cancer. The abdominal exploration, tumor staging and the abdominal chemotherapy device implantation can be completed simultaneously, which could simplify the surgical approach, improve the quality of life for patients and further propose a new direction for the development of abdominal chemotherapy.

[Prime of life for minimally invasive gastrointestinal and colorectal surgery]

With the development in the past 20 years, minimally invasive gastrointestinal and colorectal surgery is now in its prime of life, with a high level in terms of surgical technique, surgical standardization, innovative technology and technical training. However, in the prime of life, in order to avoid the decline, we must meet new challenges. With the advent of the era of 5G and artificial intelligence, plus a series of changes in the internal and external environment, minimally invasive surgery, and even the entire surgery will have a major impact, including changes in treatment patterns, emphasis of multidisciplinary comprehensive treatment, changes in disease spectrum, and except neoplasms, more benign and functional diseases may require minimally invasive surgery. The gastrointestinal surgery specialist relying on "craft" will likely be replaced by an artificial intelligence surgical system. In the face of challenges, we should not forget our initial intentions, and should diligently reflect on ourselves, keeping the patient-centered minimally invasive treatment concept. Meanwhile, we should go to the basic hospitals to further establish a standardized training system, continue to maintain innovative thinking and keep pace with the times, so that we can grasp the prime of life for minimally invasive gastrointestinal and colorectal surgery.

Tissue-Level Mechanosensitivity: Predicting and Controlling the Orientation of 3D Vascular Networks

Understanding the mechanosensitivity of tissues is a fundamentally important problem having far-reaching implications for tissue engineering. Here we study vascular networks formed by a coculture of fibroblasts and endothelial cells embedded in three-dimensional biomaterials experiencing external, physiologically relevant forces. We show that cyclic stretching of the biomaterial orients the newly formed network perpendicular to the stretching direction, independent of the geometric aspect ratio of the biomaterial's sample. A two-dimensional theory explains this observation in terms of the network's stored elastic energy if the cell-embedded biomaterial features a vanishing effective Poisson's ratio, which we directly verify. We further show that under a static stretch, vascular networks orient parallel to the stretching direction due to force-induced anisotropy of the biomaterial polymer network. Finally, static stretching followed by cyclic stretching reveals a competition between the two mechanosensitive mechanisms. These results demonstrate tissue-level mechanosensitivity and constitute an important step toward developing enhanced tissue repair capabilities using well-oriented vascular networks.

[The effect of captopril and losartan on paraquat-induced pulmonary fibrosis and PlGF expression in the lungs of rats]

Objective: To investigate the dynamic expression of placenta growth factor (PlGF) in the lungs and its role in paraquat-induced pulmonary fibrosis and to evaluate the effect of ACEI captopril and AT (1) -receptor blocker losartan on paraquat-induced pulmonary fibrosis. Methods: 84 adult healthy female Sprague-Dawley (SD) rats were randomly divided into four groups of different treatments designated as: Control, PQ alone (PQ) , captopril treatment, losartan treatment. Each group was divided into three subgroups of seven animals each. The animals were killed at either 7, 14 or 28 days after PQ administration. The rats in PQ group, treatment group were treated intragastrically (ig) with PQ (40 mg/kg) and the rats in control group were treated with the same dose of saline at the beginning of the experiment. The treatment group received Captopril (60 mg/kg; ig) or Losartan (10 mg/kg; ig) once a day respectively after PQ administration and the other two groups received saline. At the given timepoint, animals were sacrificed and lungs were harvested. A semiquantitative assay of histological examination, hydroxyproline in lung tissues were used to determine the severity of alveolitis and fibrosis. RT-PCR and immunohistochemistry were used to detect the mRNA and protein expression of PlGF. Results: Inflammatory cell infiltration and fibrotic scores were more prominent in the model group, hydroxyproline contents in lung tissue were significantly increased after PQ administration compared to the control group. Captopril, losartan apparently attenuated the degree of lung injury and pulmonary fibrosis. On 7th, 14th days, the levels of alveolitis in the intervention groups were significantly alleviated as compared with the model group (P<0.05) . On 28th days, the levels of pulmonary fibrosis in the intervention groups were significantly alleviated as compared with model group (P<0.05) . The hydroxyproline contents in the intervention groups were significantly decreased as compared with model group (P<0.01) . PlGF mRNA on day 7, 14, 28 (1.28±0.29vs0.10±0.01、0.80±0.07vs0.10±0.01、0.65±0.13vs0.10±0.01) in the PQ group were all upregulated as compared with that of the control group. PlGF mRNA on day 7, 14, 28 in the captopril and Losartan intervention groups were significantly decreased (0.94±0.04、0.71±0.09、0.52±0.24 and 0.80±0.12、0.66±0.11、0.51±0.03) . PlGF positive expression index on day 7, 14, 28 (2.27±0.34 vs0.13±0.01、1.78±0.41 vs0.14±0.03、1.25±0.69 vs0.13±0.01) in the PQ group were all upregulated as compared with that of the control group. PlGF positive expression index on day 7, 14, 28 in the captopril and Losartan treatment groups were significantly decreased (1.53±0.78、1.17±0.79、0.97±0.61 and 1.36±0.63、1.24±0.80、0.83±0.47) . PlGF positive expression index on day 7 in the two intervention groups were significantly decreased, as compared with PQ group (P<0.05) . Conclusion: PlGF may plays an important role in the development of pulmonary fibrosis following paraquat-induced lung injury in rats. Captopril and losartan had an inhibitory effect on paraquat-induced pulmonary fibrosis, and the effect may be due to inhibition of angiotensin II and, in part, be associated with reduction in PlGF.

A case report of perineal sparganosis mansoni from an endemic region

Sparganosis mansoni is a parasitic disease caused by the larva of Spirometra mansoni, which occurs worldwide, especially in Asian countries. In recent years, there have been cases of sparganosis reported in Guizhou province in southwest China. In this report, a case of sparganosis mansoni with a painful mass in perineal region is presented. The patient is a 49-year-old Chinese woman, she did not have a history of eating raw frogs or snakes. But she drank unboiled water from rivers and streams. Physical examination showed her vital signs were stable and blood routine examination was also regular. After surgery to remove the mass, a worm was removed from the foreign matter, which measured about 10 cm in length and 2 mm in diameter, that was identified as S. mansoni. One week after the operation, her symptoms changed significantly. To our knowledge, this is the first case of perineal sparganosis mansoni in Guizhou. Surgical removal is effective for the treatment of perineal sparganosis, followed by a course of therapy.

3D uniaxial mechanical stimulation induces tenogenic differentiation of tendon-derived stem cells through a PI3K/AKT signaling pathway

The tendon is a mechanosensitive tissue, but little is known about how mechanical stimulation selectively signals tenogenic differentiation and neo-tendon formation. In this study, we compared the impact of uniaxial and biaxial mechanical loading on tendon-derived stem cells (TDSCs). Our data show that there are variations in cell signaling and cell differentiation of mouse TDSCs in response to uniaxial and biaxial loading in monolayer culture. Whereas uniaxial loading induced TDSCs toward tenogenic and osteogenic differentiation, biaxial loading induced osteogenic, adipogenic, and chondrogenic differentiation of TDSCs. Furthermore, by applying uniaxial loading on 3-dimensional (3D) TDSC constructs, tenogenic-specific differentiation and neo-tendon formation were observed, results that were replicated in human TDSCs. We also showed that uniaxial loading induced PKB (AKT) phosphorylation (pAKT), whereas biaxial loading induced pERK. Most importantly, we found that inhibition of the PI3K/AKT signaling pathway could attenuate tenogenic differentiation and tendon formation in 3D TDSC constructs subjected to uniaxial loading. Taken together, our study highlights the importance of appropriate mechanobiological stimulation in 3D cell niches on tendon-like tissue formation and demonstrates that uniaxial mechanical loading plays an essential role in tenogenic differentiation and tendon formation by activating the PI3K/AKT signaling pathway.-Wang, T., Thien, C., Wang, C., Ni, M., Gao, J., Wang, A., Jiang, Q., Tuan, R. S., Zheng, Q., Zheng, M. H. 3D uniaxial mechanical stimulation induces tenogenic differentiation of tendon-derived stem cells through a PI3K/AKT signaling pathway.

In vitro loading models for tendon mechanobiology

Tendons are the connective tissue responsible for transferring force from muscles to bones. A key factor in tendon development, maturation, repair, and degradation is its biomechanical environment. Understanding tendon mechanobiology is essential for the development of injury prevention strategies, rehabilitation protocols and potentially novel treatments in tendon injury and degeneration. Despite the simple overall loading on tendon tissue, cells within the tissue in vivo experience a much more complex mechanical environment including tension, compression and shear forces. This creates a substantial challenge in the establishment of in vitro loading models of the tendon. This article reviews multiple loading models used for the study of tendon mechanobiology and summarizes the main findings. Although impressive progress has been achieved in the functionality and mimicry of in vitro loading models, an ideal platform is yet to be developed. Multidisciplinary approaches and collaborations will be the key to unveiling the tendon mechanobiology. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:566-575, 2018.

Bioinspired Technologies to Connect Musculoskeletal Mechanobiology to the Person for Training and Rehabilitation

Musculoskeletal tissues respond to optimal mechanical signals (e.g., strains) through anabolic adaptations, while mechanical signals above and below optimal levels cause tissue catabolism. If an individual's physical behavior could be altered to generate optimal mechanical signaling to musculoskeletal tissues, then targeted strengthening and/or repair would be possible. We propose new bioinspired technologies to provide real-time biofeedback of relevant mechanical signals to guide training and rehabilitation. In this review we provide a description of how wearable devices may be used in conjunction with computational rigid-body and continuum models of musculoskeletal tissues to produce real-time estimates of localized tissue stresses and strains. It is proposed that these bioinspired technologies will facilitate a new approach to physical training that promotes tissue strengthening and/or repair through optimal tissue loading.

The Effects of Transforming Growth Factor-β2 on Dopaminergic Graft Survival

Dopaminergic cell transplantation is a promising therapeutic approach for the treatment of Parkinson's disease, the potential of which is limited due to poor survival and low dopamine content within engrafted tissue. In this study, the ability of transforming growth factor-β2 (TGF-β2) to influence transplant survival was evaluated. Cell suspensions containing fetal rat ventral mesencephalon (VM) cells were incubated prior to surgery with vehicle (DPBS), varying concentrations of TGF-β2 (5–1000 ng/ml), or a pan-specific antibody against TGF-β (1D11, 100 ng/ml). VM cell suspensions (200,000 cells) were unilaterally implanted into the striatum of adult Sprague-Dawley rats (n = 5–11 animals/group). Following a 3-week survival period, small but viable VM grafts containing tyrosine hydroxylase-positive (TH+) neurons and fibers were present in all animals. Addition of TGF-β2 resulted in a steep, bell-shaped dose-response curve with a significant effect on TH+/dopamine cell survival. At 50 ng/ml TGF-β2, the number of surviving dopamine neurons was increased twofold compared with controls. Addition of TGF-β2 or 1D11 did not significantly influence graft volume. Further studies, possibly in combination with other neurotrophic factors, need to be performed to obtain a greater understanding of the effects of TGF-β on dopamine neurons and fetal VM cell engraftment.

The Effectiveness of Platelet-Rich Plasma in the Treatment of Tendinopathy: A Meta-analysis of Randomized Controlled Clinical Trials

BACKGROUND

Tendinopathy is very common in the general population. There are increasing numbers of clinical studies referring to platelet-rich plasma (PRP) and platelet-poor plasma (PPP) as treatments for tendinopathy.

PURPOSE

To perform a meta-analysis of the outcomes of the PRP groups by preparation method and injection technique in tendinopathy. To determine the clinical effectiveness of the preparations and to evaluate the effect of controls used in the studies reviewed.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

The PubMed, EMBASE, CINAHL, and Medline databases were searched in March 2012, April 2014, and August 2015, and randomized controlled trials using autologous blood, PRP, PPP, or autologous conditioned plasma in tendinopathy with outcome measures of pain and follow-up time of 3 months were included in this review. Trials including surgery, tendon tears, and muscle or ligament injuries were excluded. Study quality was assessed using the Cochrane Collaboration risk-of-bias tool by 2 reviewers. Data were pooled using random-effects meta-analysis. The primary outcome measure was a change in pain intensity. Where more than 1 pain scale was included, a functional score was selected ahead of a visual analog scale score.

RESULTS

A total of 18 studies (1066 participants) were included. Eight studies were deemed to be at low risk of bias. The most significant outcomes in the PRP groups were seen in those treated with highly cellular leukocyte-rich PRP (LR-PRP) preparations: GPS kit (standardized mean difference [SMD], 35.75; 95% CI, 28.40-43.10), MyCells kit (SMD, 31.84; 95% CI, 17.56-46.13), Prosys kit (SMD, 42.99; 95% CI, 37.73-48.25), and unspecified LR-PRP (SMD, 34.62; 95% CI, 31.69-37.55). When the LR-PRP system types were grouped, there was a strongly positive effect (SMD, 36.38; 95% CI, 34.00-38.77) when compared with leukocyte-poor PRP (SMD, 26.77; 95% CI, 18.31-35.22). In assessing the control groups, there was no clear difference between different types of control injections: saline (SMD, 14.62; 95% CI, 10.74-18.50), local anesthetic (SMD, 15.00; 95% CI, 7.66-22.34), corticosteroid (SMD, 23.82; 95% CI, 10.74-18.50), or dry needling (SMD, 25.22; 95% CI, 21.27-29.16).

CONCLUSION

There is good evidence to support the use of a single injection of LR-PRP under ultrasound guidance in tendinopathy. Both the preparation and intratendinous injection technique of PRP appear to be of great clinical significance.

Lateral Elbow Tendinopathy: Development of a Pathophysiology-Based Treatment Algorithm

Lateral elbow tendinopathy, commonly known as tennis elbow, is a condition that can cause significant functional impairment in working-age patients. The term tendinopathy is used to describe chronic overuse tendon disorders encompassing a group of pathologies, a spectrum of disease. This review details the pathophysiology of tendinopathy and tendon healing as an introduction for a system grading the severity of tendinopathy, with each of the 4 grades displaying distinct histopathological features. Currently, there are a large number of nonoperative treatments available for lateral elbow tendinopathy, with little guidance as to when and how to use them. In fact, an appraisal of the clinical trials, systematic reviews, and meta-analyses studying these treatment modalities reveals that no single treatment reliably achieves outstanding results. This may be due in part to the majority of clinical studies to date including all patients with chronic tendinopathy rather than attempting to categorize patients according to the severity of disease. We relate the pathophysiology of the different grades of tendinopathy to the basic science principles that underpin the mechanisms of action of the nonoperative treatments available to propose a treatment algorithm guiding the management of lateral elbow tendinopathy depending on severity. We believe that this system will be useful both in clinical practice and for the future investigation of the efficacy of treatments.

In-vivo organ engineering: Perfusion of hepatocytes in a single liver lobe scaffold of living rats

Organ decellularization is emerging as a promising regenerative medicine approach as it is able to provide an acellular, three-dimensional biological scaffold material that can be seeded with living cells for organ reengineering. However this application is currently limited to donor-derived decellularized organs for reengineering in vitro and no study has been conducted for re-engineering the decellularized organ in vivo. We developed a novel technique of a single liver lobe decellularization in vivo in live animals. Using a surgical method to generate a by-pass circulation through the portal vein and infra-hepatic vena cava with a perfusion chamber system, we decellularized the single liver lobe and recellularized it with allogenic primary hepatocytes. Our results showed that the decellularization process in vivo can preserve the vascular structural network and functional characteristics of the native liver lobe. It allows for efficient recellularization of the decellularized liver lobe matrix with allogenic primary hepatocytes. Upon the re-establishment of blood circulation, the recellularized liver lobe is able to gain the function and the allogenic hepatocytes are able to secret albumin. Our findings provide a proof of principle for the in vivo reengineering of liver.

Treatment of Articular Cartilage Defects With Microfracture and Autologous Matrix-Induced Chondrogenesis Leads to Extensive Subchondral Bone Cyst Formation in a Sheep Model

BACKGROUND

Microfracture and the autologous matrix-induced chondrogenesis (AMIC) technique are popular for the treatment of articular cartilage defects. However, breaching of the subchondral bone plate could compromise the subchondral bone structure.

HYPOTHESIS

Microfracture and AMIC will cause deleterious effects on the subchondral bone structure.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 36 sheep received an 8-mm-diameter cartilage defect in the left medial femoral condyle. Control animals (n = 12) received no further treatment, and the rest received 5 microfracture holes either with a type I/III collagen scaffold implanted (n = 12; AMIC group) or without the collagen scaffold (n = 12; microfracture group). Macroscopic infill of defects, histology, and histomorphometry of the subchondral bone were performed at 13 and 26 weeks postoperatively, and micro-computed tomography (CT) was also performed at 26 weeks postoperatively.

RESULTS

Microfracture and AMIC resulted in subchondral bone cyst formation in 5 of 12 (42%) and 11 of 12 (92%) specimens at 13 and 26 weeks, respectively. Subchondral bone changes induced by microfracture and AMIC were characterized by an increased percentage of bone volume, increased trabecular thickness, and a decreased trabecular separation, and extended beyond the area below the defect. High numbers of osteoclasts were observed at the cyst periphery, and all cysts communicated with the microfracture holes. Cartilage repair tissue was of poor quality and quantity at both time points and rarely reached the tidemark at 13 weeks.

CONCLUSION

Microfracture technique caused bone cyst formation and induced severe pathology of the subchondral bone in a sheep model.

CLINICAL RELEVANCE

The potential of microfracture technique to induce subchondral bone pathology should be considered.

Alexidine Dihydrochloride Attenuates Osteoclast Formation and Bone Resorption and Protects Against LPS-Induced Osteolysis

Aseptic loosening and periprosthetic infection leading to inflammatory osteolysis is a major complication associated with total joint arthroplasty (TJA). The liberation of bacterial products and/or implant-derived wear particles activates immune cells that produce pro-osteoclastogenic cytokines that enhance osteoclast recruitment and activity, leading to bone destruction and osteolysis. Therefore, agents that prevent the inflammatory response and/or attenuate excessive osteoclast (OC) formation and bone resorption offer therapeutic potential by prolonging the life of TJA implants. Alexidine dihydrochloride (AD) is a bisbiguanide compound commonly used as an oral disinfectant and in contact lens solutions. It possesses antimicrobial, anti-inflammatory and anticancer properties; however, its effects on OC biology are poorly described. Here, we demonstrate that AD inhibits OC formation and bone resorption in vitro and exert prophylatic protection against LPS-induced osteolysis in vivo. Biochemical analysis demonstrated that AD suppressed receptor activator of NF-κB ligand (RANKL)-induced activation of mitogen-activated protein kinases (ERK, p38, and JNK), leading to the downregulation of NFATc1. Furthermore, AD disrupted F-actin ring formation and attenuated the ability of mature OC to resorb bone. Collectively, our findings suggest that AD may be a promising prophylactic anti-osteoclastic/resorptive agent for the treatment of osteolytic diseases caused by excessive OC formation and function.

The biology and clinical evidence of microfracture in hip preservation surgery

The use of microfracture in hip arthroscopy is increasing dramatically. However, recent reports raise concerns not only about the lack of evidence to support the clinical use of microfracture, but also about the potential harm caused by violation of the subchondral bone plate. The biology and pathology of the microfracture technique were described based on observations in translational models and the clinical evidence for hip microfracture was reviewed systematically. The clinical outcomes in patients undergoing microfracture were the same as those not undergoing microfracture. However, the overall clinical evidence quality is poor in hips. This review identified only one study with Level III evidence, while most studies were Level IV. There were no randomized trials available for review. Repair tissue is primarily of fibrocartilaginous nature. Reconstitution of the subchondral bone is often incomplete and associated with poor quality repair tissue and faster degeneration. Subchondral bone cyst formation is associated with microfracture, likely secondary to subchondral bone plate disruption and a combination of pressurized synovial fluid and inflammatory mediators moving from the joint into the bone. There is a lack of clinical efficacy evidence for patients undergoing microfracture. There is evidence of bone cyst formation following microfracture in animal studies, which may accelerate joint degeneration. Bone cyst formation following microfracture has not been studied adequately in humans.

Thonzonium bromide inhibits RANKL-induced osteoclast formation and bone resorption in vitro and prevents LPS-induced bone loss in vivo

Osteoclasts (OCs) play a pivotal role in a variety of lytic bone diseases including osteoporosis, arthritis, bone tumors, Paget's disease and the aseptic loosening of orthopedic implants. The primary focus for the development of bone-protective therapies in these diseases has centered on the suppression of OC formation and function. In this study we report that thonzonium bromide (TB), a monocationic surface-active agent, inhibited RANKL-induced OC formation, the appearance of OC-specific marker genes and bone-resorbing activity in vitro. Mechanistically, TB blocked the RANKL-induced activation of NF-κB, ERK and c-Fos as well as the induction of NFATc1 which is essential for OC formation. TB disrupted F-actin ring formation resulting in disturbances in cytoskeletal structure in mature OCs during bone resorption. Furthermore, TB exhibited protective effects in an in vivo murine model of LPS-induced calvarial osteolysis. Collectively, these data suggest that TB might be a useful alternative therapy in preventing or treating osteolytic diseases.

Cyclic mechanical stimulation rescues achilles tendon from degeneration in a bioreactor system

Physiotherapy is one of the effective treatments for tendinopathy, whereby symptoms are relieved by changing the biomechanical environment of the pathological tendon. However, the underlying mechanism remains unclear. In this study, we first established a model of progressive tendinopathy-like degeneration in the rabbit Achilles. Following ex vivo loading deprivation culture in a bioreactor system for 6 and 12 days, tendons exhibited progressive degenerative changes, abnormal collagen type III production, increased cell apoptosis, and weakened mechanical properties. When intervention was applied at day 7 for another 6 days by using cyclic tensile mechanical stimulation (6% strain, 0.25 Hz, 8 h/day) in a bioreactor, the pathological changes and mechanical properties were almost restored to levels seen in healthy tendon. Our results indicated that a proper biomechanical environment was able to rescue early-stage pathological changes by increased collagen type I production, decreased collagen degradation and cell apoptosis. The ex vivo model developed in this study allows systematic study on the effect of mechanical stimulation on tendon biology.

Influence of age and gender on microarchitecture and bone remodeling in subchondral bone of the osteoarthritic femoral head

INTRODUCTION

Age and gender have been reported to have a remarkable impact on bone homeostasis. However, subchondral bone, which plays a pivotal role in the initiation and progression of OA, has been poorly investigated. This study was to investigate age- and gender-related changes of microarchitecture and bone remodeling in subchondral bone in OA.

METHODS

Subchondral trabecular bone (STB) and deeper trabecular bone (DTB) specimens were extracted in the load-bearing region of femoral heads from 110 patients with OA. Micro-CT and histomorphometry were performed to analyze microarchitectural and bone remodeling changes of all specimens.

RESULTS

Compared to DTB, STB showed more sclerotic microarchitecture, more active bone remodeling and higher frequency of bone cysts. There were no gender differences for both microarchitecture and bone remodeling in STB. However, gender differences were found in DTB, with thinner Tb.Th, higher Tb.N, higher OS/BV and ES/BV in males. In both STB and DTB, no correlation between microarchitecture and age was found in both genders. However, bone remodeling of STB increased significantly with age in males, while bone remodeling of DTB increased significantly with age in females. No age or gender preference was found in subchondral bone cyst (SBC) frequency. The cyst volume fraction was correlated with neither age nor gender.

CONCLUSIONS

There were differences in microarchitecture and bone remodeling between STB and DTB, which may be due to the distinct biomechanical and biochemical functions of these two bone structures in maintaining joint homeostasis. OA changed the normal age- and gender-dependence of bone homeostasis in joints, in a site-specific manner.

Evidence for the Durability of Autologous Tenocyte Injection for Treatment of Chronic Resistant Lateral Epicondylitis: Mean 4.5-Year Clinical Follow-up

BACKGROUND

Chronic lateral epicondylitis (LE) induces cell apoptosis and autophagy, which lead to the reduction of tendon-derived cells in the torn tendon. Our previous study has shown that ultrasound-guided autologous tenocyte injection (ATI) to the torn tendon in patients with chronic resistant LE significantly improves pain, function, and structural repair at 1 year. This report is the continued assessment of the clinical outcomes of these patients at mean 4.5-year follow-up.

HYPOTHESIS

Improvements in LE clinical function and structural repair after ATI will be maintained at mean 4.5-year follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients with severe refractory LE underwent clinical evaluation and MRI before intervention. A patellar tendon needle biopsy was performed under local anesthetic, and tendon cells were expanded by in vitro culture. Autologous tenocytes were injected into the central tendinopathy identified at the common extensor tendon origin under ultrasound guidance on a single occasion. Patients underwent serial clinical evaluations for up to 5 years after ATI, including the visual analog scale (VAS) for pain, Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), Upper Extremity Functional Scale (UEFS), and grip strength. Post-ATI MRI scanning was performed at 1 year and final follow-up.

RESULTS

A total of 16 patients (9 male, 7 female), aged between 37 and 63 years, were included in the study. The mean duration of symptoms before study recruitment was 29.24 months (range, 6-240 months). One patient elected to proceed to surgery 3 months after ATI due to reinjury at work, and 1 patient died of prostate cancer with metastases during the follow-up period. The mean final follow-up time for the remaining 15 patients was 4.51 years (range, 3.08-5.17 years). No complications were observed at the patellar tendon biopsy site for any patient. No adverse events, infection, or excessive fibroblastic reactions were observed in any patient at the injection site. Clinical evaluation revealed significant (P < .001) improvement in mean VAS pain score from 5.73 at initial assessment to 1.21 (78% improvement) at final follow-up. Mean QuickDASH, UEFS, and grip strength scores also significantly (P < .001) improved from initial assessment to final follow-up (from 45.88 to 6.61 [84%], from 31.73 to 9.20 [64%], and from 19.85 to 46.60 [208%], respectively). There was no difference in mean QuickDASH and UEFS scores at 1 year and final follow-up (P > .05); however, grip strength continued to improve (P < .001). A validated MRI scoring system indicated that the mean grade of tendinopathy at the common extensor origin improved significantly (P < .001) from initial assessment (4.31) to 1 year (2.88) and was maintained (P > .05) at final follow-up (2.87). At final follow-up, 93% of patients were either highly satisfied or satisfied with their ATI treatment.

CONCLUSION

ATI significantly improved clinical function and MRI tendinopathy scores for up to 5 years in patients with chronic resistant LE who had previously undergone unsuccessful nonsurgical treatment. This study provides evidence for the midterm durability of ATI for treatment of LE tendinopathy.

Disulfiram attenuates osteoclast differentiation in vitro: a potential antiresorptive agent

Disulfiram (DSF), a cysteine modifying compound, has long been clinically employed for the treatment of alcohol addiction. Mechanistically, DSF acts as a modulator of MAPK and NF-κB pathways signaling pathways. While these pathways are crucial for osteoclast (OC) differentiation, the potential influence of DSF on OC formation and function has not been directly assessed. Here, we explore the pharmacological effects of DSF on OC differentiation, activity and the modulation of osteoclastogenic signaling cascades. We first analyzed cytotoxicity of DSF on bone marrow monocytes isolated from C57BL/6J mice. Upon the establishment of optimal dosage, we conducted osteoclastogenesis and bone resorption assays in the presence or absence of DSF treatment. Luciferase assays in RAW264.7 cells were used to examine the effects of DSF on major transcription factors activation. Western blot, reverse transcription polymerase chain reaction, intracellular acidification and proton influx assays were employed to further dissect the underlying mechanism. DSF treatment dose-dependently inhibited both mouse and human osteoclastogenesis, especially at early stages of differentiation. This inhibition correlated with a decrease in the expression of key osteoclastic marker genes including CtsK, TRAP, DC-STAMP and Atp6v0d2 as well as a reduction in bone resorption in vitro. Suppression of OC differentiation was found to be due, at least in part, to the blockade of several key receptor activators of nuclear factor kappa-B ligand (RANKL)-signaling pathways including ERK, NF-κB and NFATc1. On the other hand, DSF failed to suppress intracellular acidification and proton influx in mouse and human osteoclasts using acridine orange quenching and microsome-based proton transport assays. Our findings indicate that DSF attenuates OC differentiation via the collective suppression of several key RANKL-mediated signaling cascades, thus making it an attractive agent for the treatment of OC-mediated disorders.

Identical subchondral bone microarchitecture pattern with increased bone resorption in rheumatoid arthritis as compared to osteoarthritis

OBJECTIVES

To analyze the differences in microarchitecture and bone remodeling of subchondral bone in femoral heads from patients with rheumatoid arthritis (RA) and osteoarthritis (OA).

DESIGNS

Peri-articular bone samples, including subchondral trabecular bone (STB) and deeper trabecular bone (DTB) were extracted from the load-bearing region of femoral heads from 20 patients with RA and 40 patients with OA during hip replacement surgery. Micro-CT, histomorphometry and backscatter scanning electron microscopy (BSEM) were performed to assess microarchitecture and bone histology parameters.

RESULTS

In both RA and OA, STB showed more sclerotic microarchitecture and more active bone remodeling, compared to DTB. RA and OA showed similar microarchitecture characteristics in both STB and DTB, despite STB in RA exhibiting higher bone resorption. In addition, there was no difference in the frequency of bone cysts in STB between RA and OA. In STB, the trabecular bone surrounding subchondral bone cysts (Cys-Tb) was more sclerotic than the trabecular bone found distant to cysts (Peri-Tb), with a higher level of bone remodeling. Both Cys-Tb region and Peri-Tb region were detected to have similar microarchitectural and bone remodeling characteristics in RA and OA.

CONCLUSIONS

Apart from higher bone resorption in the general subchondral bone of RA samples, the peri-articular bone exhibited similar microarchitectural and bone remodeling characteristics in RA and OA.

Subchondral bone in osteoarthritis: insight into risk factors and microstructural changes

Osteoarthritis (OA) is a major cause of disability in the adult population. As a progressive degenerative joint disorder, OA is characterized by cartilage damage, changes in the subchondral bone, osteophyte formation, muscle weakness, and inflammation of the synovium tissue and tendon. Although OA has long been viewed as a primary disorder of articular cartilage, subchondral bone is attracting increasing attention. It is commonly reported to play a vital role in the pathogenesis of OA. Subchondral bone sclerosis, together with progressive cartilage degradation, is widely considered as a hallmark of OA. Despite the increase in bone volume fraction, subchondral bone is hypomineralized, due to abnormal bone remodeling. Some histopathological changes in the subchondral bone have also been detected, including microdamage, bone marrow edema-like lesions and bone cysts. This review summarizes basic features of the osteochondral junction, which comprises subchondral bone and articular cartilage. Importantly, we discuss risk factors influencing subchondral bone integrity. We also focus on the microarchitectural and histopathological changes of subchondral bone in OA, and provide an overview of their potential contribution to the progression of OA. A hypothetical model for the pathogenesis of OA is proposed.

Matrix-induced autologous chondrocyte implantation (MACI) for chondral defects in the patellofemoral joint

PURPOSE

Both autologous chondrocyte implantation (ACI) and tibial tubercle transfer (TTT) have been used to treat chondral defects in the patellofemoral joint resulting in clinical improvement. Our study investigates the magnetic resonance imaging (MRI) appearance of the matrix-induced autologous chondrocyte implantation (MACI) graft at 5-year follow-up to determine if it provides a durable treatment option in patients with an average age of 42 (standard deviation 11.6).

METHODS

Twenty-three patients were available for follow-up. Nine patients required realignment of the extensor mechanism with lateral release and TTT. The MRI magnetic resonance observation of cartilage repair tissue (MOCART) scoring system was used to assess the graft status. Clinical outcomes were assessed at these time periods.

RESULTS

The mean weighted MOCART composite score improved from 2.87 at 3 months to 3.39 at 5 years, indicating an intact appearance in most grafts. Graft height measured >50% of the adjacent native cartilage in 82% of patients. Clinical improvement assessed by the Knee Injury and Osteoarthritis Outcome Score, SF-36 (PCS) and the 6-minute walk test was demonstrated between pre-operative scores and final 5-year follow-up. 91% of patients would undergo MACI again. Correlation between MOCART and clinical scores were low in MACI to the patellofemoral joint. No significant difference was found in outcome between those that required realignment surgery compared with those that did not.

CONCLUSION

Patellofemoral MACI provides a durable graft on MRI assessment at 5 years with resultant clinical improvement. Further work is needed to determine which defect locations may benefit most from this procedure.

LEVEL OF EVIDENCE

IV.

The composite of hydroxyapatite and calcium sulphate: a review of preclinical evaluation and clinical applications

Recent publications have shown that the combination of α-calcium sulfate hemihydrate, the densest form of hydrates and hydroxyapatite (HA) particles gives good clinical outcome in various applications. It has large potential as bone substitute since the material transforms to bone throughout the entire volume and not only by creeping substitution, from the surface toward the inside. Release of important proteins for osteogenesis has been observed around implanted material and is speculated to be due to fast dissolution of the calcium sulfate phase in combination with the osteoconductive and bioactive nature of HA. In diabetic foot infection, the osteoconductive HA/calcium sulfate material has been successfully used loaded with antibiotics and since it is injectable, the application is minimally invasive, easy and precise. It is a bone substitute for the future.

Autologous tenocyte injection for the treatment of severe, chronic resistant lateral epicondylitis: a pilot study

BACKGROUND

Severe chronic lateral epicondylitis (LE) is associated with degenerative tendon changes, extracellular matrix breakdown, and tendon cell loss. On the basis of positive outcomes from preclinical studies, this study is the first clinical trial of autologous tenocyte injection (ATI) on severe tendinopathy associated with chronic LE.

HYPOTHESIS

Autologous tenocyte injection is a safe and effective procedure that enables a reduction in pain and improvement in function in resistant LE.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients with severe refractory LE underwent clinical evaluation and magnetic resonance imaging (MRI) before intervention. A patellar tendon needle biopsy was performed under local anesthetic, and tendon cells were expanded by in vitro culture. Tenocytes used for the injection were characterized by flow cytometry and real-time polymerase chain reaction. Autologous tenocytes were injected into the site of tendinopathy identified at the origin of the extensor carpi radialis brevis tendon under ultrasound guidance on a single occasion. Patients underwent serial clinical evaluations and repeat MRI at 12 months after intervention.

RESULTS

A total of 20 consecutive patients were included in the study. Three patients withdrew consent after enrollment and before ATI. No adverse event was reported at either biopsy or injection sites. Furthermore, no infection or excessive fibroblastic reaction was found in any patient at the injection site. Clinical evaluation revealed an improvement in mean visual analog scale scores, for a maximum pain score from 5.94 at the initial assessment to 0.76 at 12 months (P < .001). Mean quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) and grip strength scores also significantly improved over the 12-month follow-up (QuickDASH score, 45.88 [baseline] to 3.84; grip strength, 20.17 kg [baseline] to 37.38 kg; P < .001). With use of a validated MRI scoring system, the grade of tendinopathy at the common extensor origin improved significantly by 12 months (P < .001). One patient elected to proceed to surgery 3 months after ATI following a reinjury at work.

CONCLUSION

In this study, patients with chronic LE who had previously undergone an unsuccessful full course of nonoperative treatment showed significantly improved clinical function and structural repair at the origin of the common extensor tendon after ATI. This novel treatment is encouraging for the treatment of tendinopathy and warrants further evaluation.