Dike Ruan

Effects of adeno-associated virus-2-mediated human BMP-7 gene transfection on the phenotype of nucleus pulposus cells.

Bone morphogenetic protein‐7 (BMP‐7) was found to stimulate the synthesis of proteoglycans (PGs) and collagen type II. To increase the biological function of the nucleus pulposus (NP) cells, the Ad‐hBMP‐7 vector was also successfully constructed and transfected NP cells. However, the disadvantages of adenovirus limit the usefulness of the Ad‐hBMP7 vector for clinical application. The rAAV2 vector has empirical advantages, especially for clinical use, to transfer exogenous genes into cells. The purpose of this study was to first determine whether a rAAV2‐hBMP‐7 vector could be used to transfect canine NP cells and effect on the biological functions of canine NP cells. The canine NP cells transfected by the rAAV‐BMP7 were assessed semi‐quaiitatively for BMP‐7 expression with real‐time PCR and westernbloting. Aggrecan and collagens type I and II secreted by the NP cells were qualitatively assessed at 4, 7, and 14 days post‐transfection in the transfection and control groups. We found that rAAV2 can successfully transfer the hBMP‐7 gene into canine NP cells. NP cells transfected by the rAAV‐hBMP‐7 vector express hBMP‐7 for at least 14 days. At 7 and 14 days, the expressed hBMP‐7 promotes a remarkable and significant accumulation of both proteoglycans (42% and 77% higher than non‐transfected cells) (p<0.05) and collagen type II (63% and 94% higher than non‐transfected cells) (p<0.05). Thus, we could speculate that the rAAV‐based gene delivery technique promotes the expression of proteoglycans and collagen type II of nucleus pulposus cells. Moreover, this technique may be applicable for the future treatment of degenerative disc disease.

Injectable microcryogels reinforced alginate encapsulation of mesenchymal stromal cells for leak-proof delivery and alleviation of canine disc degeneration.

In situ crosslinked thermo-responsive hydrogel applied for minimally invasive treatment of intervertebral disc degeneration (IVDD) may not prevent extrusion of cell suspension from injection site due to high internal pressure of intervertebral disc (IVD), causing treatment failure or osteophyte formation. In this study, mesenchymal stromal cells (MSCs) were encapsulated in alginate precursor and loaded into previously developed macroporous PGEDA-derived microcryogels (PMs) to form three-dimensional (3D) microscale cellular niches, enabling non-thermo-responsive alginate hydrogel to be injectable. The PMs reinforced alginate hydrogel showed superior elasticity compared to alginate hydrogel alone and could well protect encapsulated cells through injection. Chondrogenic committed MSCs in the injectable microniches expressed higher level of nucleus pulposus (NP) cell markers compared to 2D cultured cells. In an ex vivo organ culture model, injection of MSCs-laden PMs into NP tissue prevented cell leakage, improved cell retention and survival compared to free cell injection. In canine IVDD models, alleviated degeneration was observed in MSCs-laden PMs treated group after six months which was superior to other treated groups. Our results provide in-depth demonstration of injectable alginate hydrogel reinforced by PMs as a leak-proof cell delivery system for augmented regenerative therapy of IVDD in canine models.

Blocking the Function of Inflammatory Cytokines and Mediators by Using IL-10 and TGF-β: A Potential Biological Immunotherapy for Intervertebral Disc Degeneration in a Beagle Model

The debilitating effects of lower back pain are a major health issue worldwide. A variety of factors contribute to this, and oftentimes intervertebral disk degeneration (IDD) is an underlying cause of this disorder. Inflammation contributes to IDD, and inflammatory cytokines such as tumor necrosis factor (TNF)-α and interleukin (IL)-1β, play key roles in the pathology of IDD. Therefore, the development of treatments that inhibit the expression and/or effects of TNF-α and IL-1β in IDD patients should be a promising therapeutic approach to consider. This study characterized the potential to suppress inflammatory cytokine production in degenerative intervertebral disc (NP) cells by treatment with IL-10 and TGF-β in a canine model of IDD. IDD was induced surgically in six male beagles, and degenerative NP cells were isolated and cultured for in vitro studies on cytokine production. Cultured degenerative NP cells were divided into four experimental treatment groups: untreated control, IL-10-treated, TGF-β-treated, and IL-10- plus TGF-β-treated cells. Cultured normal NP cells served as a control group. TNF-α expression was evaluated by fluorescence activated cell sorting (FACS) analysis and enzyme-linked immunosorbent assay (ELISA); moreover, ELISA and real-time PCR were also performed to evaluate the effect of IL-10 and TGF-β on NP cell cytokine expression in vitro. Our results demonstrated that IL-10 and TGF-β treatment suppressed the expression of IL-1β and TNF-α and inhibited the development of inflammatory responses. These data suggest that IL-10 and TGF-β should be evaluated as therapeutic approaches for the treatment of lower back pain mediated by IDD.

Quantitative T2 magnetic resonance imaging compared to morphological grading of the early cervical intervertebral disc degeneration: an evaluation approach in asymptomatic young adults.

Objective The objective of this study was to evaluate the efficacy of quantitative T2 magnetic resonance imaging (MRI) for quantifying early cervical intervertebral disc (IVD) degeneration in asymptomatic young adults by correlating the T2 value with Pfirrmann grade, sex, and anatomic level. Methods Seventy asymptomatic young subjects (34 men and 36 women; mean age, 22.80±2.11 yr; range, 18–25 years) underwent 3.0-T MRI to obtain morphological data (one T1-fast spin echo (FSE) and three-plane T2-FSE, used to assign a Pfirrmann grade (I–V)) and for T2 mapping (multi-echo spin echo). T2 values in the nucleus pulposus (NP, n = 350) and anulus fibrosus (AF, n = 700) were obtained. Differences in T2 values between sexes and anatomic level were evaluated, and linear correlation analysis of T2 values versus degenerative grade was conducted. Findings Cervical IVDs of healthy young adults were commonly determined to be at Pfirrmann grades I and II. T2 values of NPs were significantly higher than those of AF at all anatomic levels (P<0.000). The NP, anterior AF and posterior AF values did not differ significantly between genders at the same anatomic level (P>0.05). T2 values decreased linearly with degenerative grade. Linear correlation analysis revealed a strong negative association between the Pfirrmann grade and the T2 values of the NP (P = 0.000) but not the T2 values of the AF (P = 0.854). However, non-degenerated discs (Pfirrmann grades I and II) showed a wide range of T2 relaxation time. T2 values according to disc degeneration level classification were as follows: grade I (>62.03 ms), grade II (54.60–62.03 ms), grade III (<54.60 ms). Conclusions T2 quantitation provides a more sensitive and robust approach for detecting and characterizing the early stage of cervical IVD degeneration and to create a reliable quantitative in healthy young adults.

The 50 Most-cited Articles in Orthopaedic Surgery From Mainland China

BackgroundCitation analysis has been widely used to evaluate the impact of articles in medical and surgical specialties. Although China is the most populous country in the world, and although more than 50,000 orthopaedic surgeons practice there, to our knowledge no formal citation analysis of Chinese orthopaedic articles has been performed.Questions/purposesWe identified the 50 most-cited orthopaedic articles from mainland China and evaluated these articles in terms of their language of publication, source journals, and topics.MethodsScience Citation Index Expanded was searched in July 31, 2014 for citations of articles published in 70 selected journals since the inception of the database. The 50 most-cited orthopaedic articles originating in mainland China were identified. Basic information, including title, authors, year of publication, article type, journal in which the work was published, city, institution, number of citations, decade published, and topic or subspecialty of the research were recorded.ResultsThe number of citations for the top 50 papers ranged from 181 to 31 (mean, 52). These articles were published between 1981 and 2010. The decade of 2000 to 2009 was the most prolific, with 36 of the top 50 articles published during this time. All articles were written in English and they were published in a total of 16 journals. The journal Spine published the largest number of articles (12), followed by Clinical Orthopaedics and Related Research® (seven). The journal Lancet had the highest impact factor (39.207 for 2013) among any of the journals that published articles we identified. The top 50 articles originated mainly from Beijing (16) and Shanghai (12), with basic research being the focus of the majority (27 of 50; 54%); the remaining were clinical studies. Bone was the most-investigated topic in basic research; the spine was the most-common topic among the identified clinical studies.ConclusionsThe 50 most-cited articles that we identified should be considered influential, although a large gap remains between mainland China and the global orthopaedic community in terms of citations per article. Nevertheless, insofar as the most-recent decade of our survey generated the most articles in this top-50 list, we would characterize mainland China’s effect on musculoskeletal research as increasing, and as funding increases to programs in mainland China, we anticipate this trend will continue in the future.

Fusion-nonfusion hybrid construct versus anterior cervical hybrid decompression and fusion: a comparative study for 3-level cervical degenerative disc diseases.

Study Design. A retrospective analysis. Objective. This study aimed to compare the safety and efficacy between the fusion-nonfusion hybrid construct (HC: anterior cervical corpectomy and fusion plus artificial disc replacement, ACCF plus cADR) and anterior cervical hybrid decompression and fusion (ACHDF: anterior cervical corpectomy and fusion plus discectomy and fusion, ACCF plus ACDF) for 3-level cervical degenerative disc diseases (cDDD). Summary of Background Data. The optimal anterior technique for 3-level cDDD remains uncertain. Long-segment fusion substantially induced biomechanical changes at adjacent levels, which may lead to symptomatic adjacent segment degeneration. Hybrid surgery consisting of ACDF and cADR has been reported with good results for 2-level cDDD. In this context, ACCF combining with cADR may be an alternative to ACHDF for 3-level cDDD. Methods. Between 2009 and 2012, 28 patients with 3-level cDDD who underwent HC (n = 13) and ACHDF (15) were retrospectively reviewed. Clinical assessments were based on Neck Disability Index, Japanese Orthopedic Association disability scale, visual analogue scale, Japanese Orthopedic Association recovery rate, and Odom criteria. Radiological analysis included range of motion of C2–C7 and adjacent segments and cervical lordosis. Perioperative parameters, radiological adjacent-level changes, and the complications were also assessed. Results. HC showed better Neck Disability Index improvement at 12 and 24 months, as well as Japanese Orthopedic Association and visual analogue scale improvement at 24 months postoperatively (P < 0.05). HC had better outcome according to Odom criteria but not significantly (P > 0.05). The range of motion of C2–C7 and adjacent segments was less compromised in HC (P < 0.05). Both 2 groups showed significant lordosis recovery postoperatively (P < 0.05), but no difference was found between groups (P > 0.05). The incidence of adjacent-level degenerative changes and complications was higher in ACHDF but not significantly (P > 0.05). Conclusion. HC may be an alternative to ACHDF for 3-level cDDD due to the equivalent or superior early clinical outcomes, less compromised C2–C7 range of motion, and less impact at adjacent levels. Level of Evidence: 3

Progressive dysphagia and neck pain due to diffuse idiopathic skeletal hyperostosis of the cervical spine: a case report and literature review

Diffuse idiopathic skeletal hyperostosis (DISH) is considered an underdiagnosed and mostly asymptomatic nonprimary osteoarthritis. The etiology of DISH remains unknown and the validated diagnostic criteria are absent. This condition is still recognized radiologically only. Rarely, large projecting anterior osteophytes result in esophageal impingement and distortion leading to dysphagia. We report the case of progressive dysphagia and neck pain due to DISH of the cervical spine in a 70-year-old man, which was surgically removed with excellent postoperative results and complete resolution of symptoms. Imaging studies, surgical findings, and histopathological examinations were used to support the diagnosis. The patient was successfully treated with total excision of the anterior osteophytes with no evidence of recurrence 12 months after surgery. In this report, we also discuss the clinical features and perioperative considerations in combination with a literature review. Our patient illustrates that clinicians should be aware of this rare clinical manifestation as the presenting feature of DISH in cervical spine. Surgical decompression through osteophytectomy is effective for patients who fail conservative treatment.

Prolonged expansion of human nucleus pulposus cells expressing human telomerase reverse transcriptase mediated by lentiviral vector

Human degenerative disc disease (DDD) is characterized by progressive loss of human nucleus pulposus (HNP) cells and extracellular matrix, in which the massive deposition are secreted by HNP cells. Cell therapy to supplement HNP cells to degenerated discs has been thought to be a promising strategy to treat DDD. However, obtaining a large quality of fully functional HNP cells has been severely hampered by limited proliferation capacity of HNP cells in vitro. Previous studies have used lipofectamine or recombinant adeno‐associated viral (rAAV) vectors to deliver human telomerase reverse transcriptase (hTERT) into ovine or HNP cells to prolong the activity of nucleus pulposus cells with limited success. Here we developed a lentiviral vector bearing both hTERT and a gene encoding green fluorescence protein (L‐hTERT/EGFP). This vector efficiently mediated both hTERT and EGFP into freshly isolated HNP cells. The expressions of both transgenes in L‐hTERT/EGFP transduced HNP cells were detected up to day 210 post viral infection, which was twice as long as rAAV vector did. Furthermore, we observed restored telomerase activity, maintained telomere length, delayed cell senescence, and increased cell proliferation rate in those L‐hTERT/EGFP transduced HNP cells. Our study suggests that lentiviral vector might be a useful gene delivery vehicle for HNP cell therapy to treat DDD.

Operative versus nonoperative treatment for complex proximal humeral fractures: a meta-analysis of randomized controlled trials.

Whether operative treatment for complex proximal humeral fractures has a greater benefit over nonoperative treatment is uncertain. The authors conducted a meta-analysis to include all randomized controlled trials (RCTs) to determine the advantages and disadvantages of operative vs nonoperative treatment. Multiple databases, online registries of RCTs, and proceedings from major meetings were systematically searched up to November 2012. Randomized controlled trials comparing operative and non-operative treatment for 3- and 4-part proximal humeral fractures were included. Two authors independently assessed methodological quality and extracted data. Seven articles with a total of 286 patients met inclusion criteria. No significant differences were found between operative and nonoperative treatment regarding Constant score, the Disabilities of the Arm, Shoulder and Hand score, American Shoulder and Elbow Surgeons score, Simple Shoulder Test, 15 Dimensions, and complications. Health-related quality of life according to the EuroQol-5D score in operative treatment showed statistically, but not clinically, significant improvement compared with nonoperative treatment. Operative treatment could significantly increase the incidence of additional surgery at 12- and 24-month follow-up compared with nonoperative treatment. However, sensitivity analysis showed a higher additional surgery rate at 12-month follow-up remained unstable. On the basis of current evidence, both operative and nonoperative treatment can achieve a similar treatment effect on complex proximal humeral fractures, but operative treatment may increase the occurrence of additional surgery. However, due to some limitations, the result of this meta-analysis should be cautiously interpreted, and further studies are needed.

Human bone morphogenetic protein 7 transfected nucleus pulposus cells delay the degeneration of intervertebral disc in dogs.

The main reason for intervertebral disc (IVD) degeneration is the decrease in the quantity and activity of IVD cells with subsequent reduction of the extracellular matrix (ECM). In this study, we investigated a cell‐based repair strategy by injecting nucleus pulposus cells (NPCs) transduced with human bone morphogenetic protein (hBMP7) by adeno‐associated virus‐2 into the canine degenerative IVD to determine whether NPCs expressing hBMP7 could delay the degeneration of the IVD. Fourteen canines received annular punctures to induce disc degeneration. Eight weeks later, saline (group A), allogeneic NPCs (group B), or allogeneic NPCs transduced with hBMP7 (group C) were injected into the degenerative discs. Twelve weeks after the injection, MRI scan showed that the degeneration process of groups C was slower and less severe compared with that of groups B and C. The IVD stability in group C was superior to that in groups A and B in left‐right bending and rotation. HE, safranin‐O staining, and ELISA indicated that the degenerative degree of the IVD in group C was significantly milder than that in groups A and B. The study demonstrated that the implantation of NPCs‐hBMP7 could effectively maintained the structural integrity, ECM, and biomechanical properties of the canine degenerated discs.