Outcomes from different aspects indicate the all-inside technique may serve as an ideal option for anterior cruciate ligament reconstruction.

PURPOSE: To evaluate the postoperative outcomes of the all-inside technique in arthroscopic anterior cruciate ligament reconstruction (ACLR). METHODS: Patients who underwent ACLR using the all-inside technique between 2018 and 2021 were retrospectively assessed. All patients were followed up for at least 2 years. Functional recovery and pain relief were assessed using the International Knee Documentation Committee (IKDC) score, Lysholm score, Knee Injury and Osteoarthritis Outcome Score (KOOS) and visual analogue scale (VAS). Instrumented laxity was assessed via side-to-side difference using the Kneelax3 arthrometer. Graft maturity was estimated using the signal-to-noise quotient value based on magnetic resonance imaging (MRI). Adverse events during and after the surgery were recorded. RESULTS: A total of 78 patients were included in this study, with a mean age of 28.1 ± 7.6 years. The IKDC (p < 0.001), Lysholm (p < 0.001) and KOOS (p < 0.001 for all subgroups) scores at the final follow-up were significantly higher than those before the surgery. The VAS scores (p < 0.05) were significantly lower than those before surgery. The side-to-side difference results indicated that 50 patients had a difference of less than 3 mm, indicating a tight graft, whereas only 1 patient had a difference of >5 mm, indicating a loose graft. The median signal-to-noise quotient of the graft on MRI was 1.4 (P25, P75: 1.0, 2.0). No intraoperative adverse events were observed. Postoperative adverse events included three cases of infection, three cases of graft rerupture, two cases of cyclops lesion and one case of surgical intervention for a meniscal tear. CONCLUSION: ACLR using the all-inside technique offers promising results in patients with ACL rupture. LEVEL OF EVIDENCE: Level IV.

Internal brace augmentation reconstruction versus standard anterior cruciate ligament reconstruction: a randomised controlled clinical trial study protocol.

INTRODUCTION: Anterior cruciate ligament (ACL) rupture is one of the most common knee injuries in sports, and the gold standard for treating ACL rupture is tendon graft reconstruction. Internal brace technology is being used nowadays for ligament repair; however, more relevant in vivo clinical evidence is required for using internal brace technology in ACL reconstruction (ACLR). We conducted a randomised controlled trial to investigate the clinical efficacy of internal brace technology in ACLR. METHODS AND ANALYSIS: This randomised, parallel-controlled trial included patients with ACL rupture who underwent inpatient surgery at the Department of Orthopaedics, Xiangya Hospital, Central South University. Random number table method was used to assign the participants to either the test or the control group. The test group underwent ACLR using the internal brace technique, whereas the control group underwent standard ACLR. Uniform postoperative rehabilitation protocol was used for both the groups. Patient-reported outcomes included preoperative baseline and postoperative recovery at 1, 3, 6, 12 and 24 months. The primary outcome was International Knee Documentation Committee function from baseline (ACL rupture) to 6 months postoperatively. Secondary outcomes included (1) other patient outcome reporting metrics, Lysholm knee score, Knee Injury and Osteoarthritis Outcome Score and Visual Analog Scale; (2) the use of Kneelax3 knee stabiliser to assess knee stability; (3) occurrence of adverse events, such as graft refraction or symptomatic instability, postoperative infection and contralateral injury and (4) magnetic resonance images at 12 and 24 months after ACLR. ETHICS AND DISSEMINATION: This trial was approved by the Medical Ethics Committee of the Xiangya Hospital of Central South University on 26 October 2021. Data will be published in peer-reviewed journals and presented at national and international conferences. TRIAL REGISTRATION NUMBER: ChiCTR2200057526.

Valid and reliable diagnostic performance of dual-energy CT in anterior cruciate ligament rupture.

OBJECTIVES: To determine whether dual-energy CT (DECT) can be used to accurately and reliably detect anterior cruciate ligament (ACL) rupture. MATERIALS AND METHODS: Participants with unilateral ACL rupture were prospectively enrolled, and the bilateral knees were scanned by DECT. A tissue-specific mapping algorithm was applied to improve the visualization of the ACLs. The 80-keV CT value, mixed-keV CT value, electron density (Rho), and effective atomic number (Zeff) were measured to quantitatively differentiate torn ACLs from normal ACLs. MRI and arthroscopy served as the reference standards. RESULTS: Fifty-one participants (mean age, 27.0 ± 8.7 years; 31 men) were enrolled. Intact and torn ACLs were explicitly differentiated on color-coded DECT images. The 80-keV CT value, mixed-keV CT value, and Rho were significantly lower for the torn ACLs than for the intact ACLs (p < 0.001). The optimal cutoff values were an 80-keV CT value of 61.8 HU, a mixed-keV CT value of 60.9 HU, and a Rho of 51.8 HU, with AUCs of 98.0% (95% CI: 97.0-98.9%), 99.2% (95% CI: 98.6-99.7%), and 99.8% (95% CI: 99.6-100.0%), respectively. Overall, DECT had almost perfect reliability and validity in detecting ACL integrity (sensitivity = 97.1% [95% CI: 88.1-99.8%]; specificity = 98.0% [95% CI: 89.5-99.9%]; PPV = 98.0% [95% CI: 93.0-99.8%]; NPV = 97.1% [95% CI: 91.7-99.4%]; accuracy = 97.5% [95% CI: 94.3-99.2%]). There was no evidence of a difference between MRI and DECT in the diagnostic performance (p > 0.99). CONCLUSION: DECT has excellent diagnostic accuracy and reliability in qualitatively and quantitatively diagnosing ACL rupture. CLINICAL RELEVANCE STATEMENT: DECT could validly and reliably diagnose ACL rupture using both qualitative and quantitative methods, which may become a promising substitute for MRI to evaluate the integrity of injured ACLs and the maturity of postoperative ACL autografts. KEY POINTS: • On color-coded DECT images, an uncolored ACL was a reliable sign for qualitatively diagnosing ACL rupture. • The 80-keV CT value, mixed-keV CT value, and Rho were significantly lower for the torn ACLs than for the intact ACLs, which contributed to the quantitative diagnosis of ACL rupture. • DECT had an almost perfect diagnostic performance for ACL rupture, and diagnostic capability was comparable between MRI and DECT.

Do people become more proactive at work as they grow older? Examining the mediating roles of intrinsic motivation, emotional exhaustion, and career aspiration.

Today, there is an increasingly aging workforce. Previous studies have examined whether aged people exhibit more positive attitudes, better health, and better performance. However, the relationship between age and proactive work behavior has seldom been examined, which is unfortunate since organizations need employee proactivity to deal with uncertainty and unpredictability. Based on socioemotional selectivity theory, we propose that age might be positively related to proactive work behavior through intrinsic motivation and emotional exhaustion because older people tend to manage their emotions and obtain intrinsic enjoyment. But age might be negatively related to proactive work behavior through career aspiration because older people focus less on future development. With a sample of 393 people, we revealed intrinsic motivation and career aspiration. The findings could help us better understand how age is related to organizational outcomes and individual differences in proactive work behavior. They could also further reduce age-related discrimination and encourage organizations to manage older people in wise and better ways.

Surgical treatment of patellar dislocation: A network meta-analysis of randomized control trials and cohort studies.

Background: Currently, there are many surgical options for patellar dislocation. The purpose of this study is to perform a network meta-analysis of the randomized controlled trials (RCTs) and cohort studies to determine the better treatment. Method: We searched the Pubmed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, clinicaltrials.gov and who.int/trialsearch. Clinical outcomes included Kujala score, Lysholm score, International Knee Documentation Committee (IKDC) score, redislocation or recurrent instability. We conducted pairwise meta-analysis and network meta-analysis respectively using the frequentist model to compare the clinical outcomes. Results: There were 10 RCTs and 2 cohort studies with a total of 774 patients included in our study. In network meta-analysis, double-bundle medial patellofemoral ligament reconstruction (DB-MPFLR) achieved good results on functional scores. According to the surface under the cumulative ranking (SUCRA), DB-MPFLR had the highest probabilities of their protective effects on outcomes of Kujala score (SUCRA 96.5 %), IKDC score (SUCRA 100.0%) and redislocation (SUCRA 67.8%). However, DB-MPFLR (SUCRA 84.6%) comes second to SB-MPFLR (SUCRA 90.4%) in Lyshlom score. It is (SUCRA 70%) also inferior to vastus medialis plasty (VM-plasty) (SUCRA 81.9%) in preventing Recurrent instability. The results of subgroup analysis were similar. Conclusion: Our study demonstrated that MPFLR showed better functional scores than other surgical options.

The effect of hamstring donor-site block for functional outcomes and rehabilitation after anterior cruciate ligament reconstruction.

Purpose: To determine the effect of local infiltration anesthesia (LIA) at the donor site combined with a femoral nerve block (FNB) on short-term postoperative pain, functional outcomes, and rehabilitation after arthroscopic hamstring tendon autograft anterior cruciate ligament reconstruction (ACLR). Methods: This study was a single center, randomized controlled trial. Seventy-three subjects with ACL rupture were enrolled. Participants were randomly allocated to two groups, 47 in the experimental group (Group A) and 26 in the control group (Group B). All operations were performed under FNB. In Group A, 10 ml of 1% ropivacaine was injected precisely at the hamstring donor site. Patients in Group B were treated with the same amount of saline. Preoperatively and postoperatively, pain scores based on the numerical rating scale (NRS) and consumption of opioids were recorded. In addition, knee functions were assessed by the International Knee Documentation Committee Subjective Knee Form (IKDC), the Lysholm score, and the Knee injury and Osteoarthritis Outcome Score (KOOS) preoperatively and postoperatively at 1 and 3 months. In addition, we applied the KNEELAX3 arthrometer to evaluate the stability of the knee preoperatively and postoperatively so that subjective and objective knee conditions were obtained to help us assess knee recovery in a comprehensive manner. Results: The hamstring donor-site block reduced pain within the first 12 postoperative hours. There were no significant differences between two groups in pain intensity preoperatively and equal to or greater than 24 hours postoperatively. Furthermore, there were no differences between the groups concerning knee functions preoperatively or in the short-term follow-up at 1 and 3 months. Conclusion: LIA at the donor site can effectively improve the early postoperative pain of patients after ACLR and reduce the use of opioids without affecting the functional outcomes of the surgery.

Eccentrically widened bone tunnels after all-inside anterior cruciate ligament reconstruction: a computed tomography and three-dimensional model-based analysis.

PURPOSE: To evaluate the extent of tunnel widening after anterior cruciate ligament reconstruction (ACLR) using the all-inside technique and to establish its correlation with patient-reported clinical outcomes and femoral graft bending angle (GBA). METHODS: Tunnel widening was evaluated using computed tomography (CT)-based three-dimensional (3D) models, and the femoral GBA was directly measured on CT images using the Picture Archiving and Communication System (PACS) software. Clinical follow-up was routine procedure, and patient-reported clinical outcomes mainly included International Knee Documentation Committee (IKDC), Lysholm, and Knee Injury and Osteoarthritis Outcome Scores (KOOS) scores, and subjective knee stability assessment. RESULTS: Fifty-two patients received standard all-inside ACLR, with a median follow-up of 6 months. Reconstructed anterior cruciate ligaments (ACLs) were scanned during the first 3 days and 6 months after surgery. On both the femoral and tibial sides, bone tunnels were most significantly enlarged at the articular aperture segment; the femoral tunnel was 9.2 ± 1.3 mm postoperatively and was significantly enlarged by 32% to a mean tunnel diameter of 12.1 ± 2.0 mm at 6 months after surgery. Moreover, the extent of tunnel enlargement gradually decreased as the measured levels approached those of the bone cortex. The femoral tunnel center was shifted into the anterior and distal direction, and the tibial tunnel center was shifted into the posterior and lateral direction. Additionally, the mean femoral GBA was 105.9° ± 8.1° at the 6-month follow-up. Tunnel enlargement and GBA were not significantly correlated with patient-reported outcomes. CONCLUSIONS: Femoral and tibial tunnels were significantly greater and eccentrically shifted at the 6-month follow-up after all-side ACLR. However, the extent of tunnel widening does not markedly affect the short-term clinical outcomes. Meanwhile, the femoral GBA was not significantly correlated with femoral tunnel widening or patient-reported outcomes. Although the tunnel widening following all-inside ACLR was not associated with clinical outcomes, it potentially caused difficulties in revision ACLR. LEVEL OF EVIDENCE: Level IV.

Connexin43 in Musculoskeletal System: New Targets for Development and Disease Progression.

Connexin43, which is the most highly expressed connexin subtype in the musculoskeletal system, exists in a variety of bone cells, synovial tissue, and cartilage tissue. Connexin43 has been suggested to be a key regulator of bone homeostasis. Studies have shown aberrant Connexin43 expression in musculoskeletal disorders, such as osteoporosis, osteoarthritis, and rheumatoid arthritis. During cellular activities, Connexin43 can participate in the formation of functionally specific gap junctions and hemichannels and can exert independent cellular regulatory and signaling functions through special C-termini. The critical role of Connexin43 in physiological development and disease progression has been gradually revealed. In this article, the function of Connexin43 in musculoskeletal tissues is summarized, revealing the potential role of Connexin43 as a key target in the treatment of related bone and muscle disorders and the need for further discovery.

A worldwide bibliometric analysis of triptolide research from 1997 to 2021.

OBJECTIVES: In recent years, triptolide has received much attention due to its wide range of pharmacological activities. However, no bibliometric studies have been published on triptolide. This study conducted a bibliometric study to provide scientific and insightful information for further research. METHODS: This study performed a bibliometric study of articles published in the Web of Science database from 1997 to 2021. Based on the keywords used in relation to the title of the article containing the word triptolide, 970 publications were searched for further analysis. We used Microsoft Excel for frequency analysis, VOSviewer and CiteSpace for data visualization, and Rstudio for citation metrics and analysis. RESULTS: After analysis, standard bibliometric indicators such as the growth of publications, prolific authors and coauthorship, country distributions, preferred journals, most influential institutions and top cited documents were presented in this study. CONCLUSIONS: According to our findings, the number of triptolide-related publications has been increasing since 2009. China was the largest contributor to triptolide research, followed by the USA. Biomedicine & Pharmacotherapy was the leading journal related to triptolide research. The most productive authors were Zhang LY (China Pharmaceut Univ) and Jiang ZZ (China Pharmaceut Univ). China Pharmaceutical University was the most influential institution in the field of triptolide research. Our findings suggest that the effective use of triptolide in cancer therapy as well as overcoming its multiorgan toxicity to promote its widespread clinical applications are expected to be hot research topics in the future.

Comparison of in vivo hindfoot joints motion changes during stance phase between non-flatfoot and stage II adult acquired flatfoot.

BACKGROUND: To compare the kinematic characteristics of hindfoot joints in stage II adult acquired flatfoot deformity (AAFD) with those of non-flatfoot through the 3D-to-2D registration technology and single fluoroscopic imaging system. METHODS: Eight volunteers with stage II AAFD and seven volunteers without stage II AAFD were recruited and CT scans were performed bilateral for both groups in neutral positions. Their lateral dynamic X-ray data during the stance phase, including 14 non-flatfeet and 10 flatfeet, was collected. A computer-aided simulated light source for 3D CT model was applied to obtain the virtual images, which were matched with the dynamic X-ray images to register in the "Fluo" software, so that the spatial changes during the stance phase could be calculated. RESULTS: During the early-stance phase, the calcaneous was more dorsiflexed, everted, and externally-rotated relative to the talus in flatfoot compared with that in non-flatfoot (p < 0.05). During the mid-stance phase, the calcaneous was more dorsiflexed and everted relative to the talus in flatfoot compared with that in non-flatfoot (p < 0.05); however, the rotation did not differ significantly between the two groups (p > 0.05). During the late-stance phase, the calcaneous was more plantarflexed, but less inverted and internally-rotated, relative to the talus in flatfoot compared with that in non-flatfoot (p < 0.05). During the early- and mid-stance phase, the navicular was more dorsiflexed, everted, and externally-rotated relative to the talus in flatfoot compared with that in non-flatfoot (p < 0.05). During the late-stance phase, the navicular was more plantarflexed, but less inverted and internally-rotated, relative to the talus in flatfoot compared with that in non-flatfoot (p < 0.05). There was no difference in the motion of cuboid between the two groups during the whole stance phase (p > 0.05). CONCLUSIONS: During the early- and mid-stance phase, excessive motion was observed in the subtalar and talonavicular joints in stage II AAFD. During the late-stance phase, the motion of subtalar and talonavicular joints appeared to be in the dysfunction state. The current study helps better understanding the biomechanics of the hindfoot during non-flatfoot and flatfoot condition which is critical to the intervention to the AAFD using conservative treatment such as insole or surgical treatment for joint hypermotion.

The top 100 most-cited articles on exercise therapy for sarcopenia: A bibliometric analysis.

Objective: Vast quantities of literature regarding the applications of exercise therapy for sarcopenia have been published. The main objective of this study is to determine the top 100 most-cited articles and analyze their bibliometric characteristics. Design: This study reports a bibliometric analysis via a systematic search of the academic literature regarding the applications of exercise therapy for sarcopenia. Methods: All databases in the Web of Science were searched with the following strategy: term search (TS) = (exercise* OR training OR "physical activit*") AND TS = (sarcopenia) on 25 February 2022. The results were presented in descending order by their total citations. The list of the top 100 articles was finally determined by negotiation of two independent researchers. Results: The top 100 articles were published between 1993 and 2020. More than half of the articles (n = 54) were published during the decade 2006-2015. Total citations of the top 100 articles ranged from 155 to 1,131 with a median of 211.5. The average of annual citations was constantly increasing with year (P < 0.05). The most studied exercise therapy is strength/resistance training, with about 71% articles had discussed about it. The top 100 articles were from 54 different journals, and the Journal of Applied Physiology was the journal that contributed the most articles (n = 8). A total of 75 different first corresponding authors from 15 countries made contributions to the top 100 list. Luc J.C. van Loon from the Maastricht University in the Netherlands published the most articles (n = 5) as the first corresponding author. Most articles (87%) were from North America (58%) and Europe (29%), while the United States as a country contributed over half of the articles (51%). Conclusion: Our study determined the top 100 most-cited articles on exercise therapy for sarcopenia and analyzed their bibliometric characteristics, which may provide a recommended list for researchers in this field and pave the way for further research.

Global Trends and Current Status in Osteonecrosis of the Femoral Head: A Bibliometric Analysis of Publications in the Last 30 Years.

Introduction: Osteonecrosis of the femoral head (ONFH) is a progressive and disabling disease with severe socioeconomic burdens. In the last 30 years, a growing number of publications have reported significant advances in understanding ONFH. However, only a few studies have clarified its global trends and current status. Thus, the purpose of our study was to summarize the global trends and current status in ONFH through bibliometrics. Materials and Methods: Publications related to ONFH from 1991 to 2020 were searched from the Web of Science (WOS) core collection database. The data were analyzed with bibliometric methods. Microsoft Excel was used for statistical analysis and to draw bar charts. SPSS was applied to perform linear regression analysis. VOSviewer was used to conduct bibliographic coupling analysis, co-authorship analysis, co-citation analysis and co-occurrence analysis. Results: A total of 5,523 publications were covered. The United States consistently ranked first in total publications, sum of times cited, average citations per item and H-index. Kyushu University was the main contributor to ONFH. Clinical Orthopaedics and Related Research was the major publishing channels for ONFH-related articles. Takuaki Yamamoto published the most ONFH-related articles. Studies regarding ONFH could be divided into five clusters: 1) mechanism study, 2) treatment study, 3) complication study, 4) radiological study and 5) etiological study. Mechanism study might become a hot spot in the future. Conclusions: The total number of publications in ONFH has generally increased over the last three decades. The United States was the leading country in ONFH research. Transplantation, engineering, cell and molecular biology, pharmacology and endocrinology have gradually increased and become hot topics in ONFH research. Mechanism study in ONFH including mesenchymal stem cells, apoptosis, oxidative stress, adipogenesis, osteogenic differentiation and endothelial progenitor cells, have attracted more attention and will become a hot spot in the future.

EBF1-mediated up-regulation of lncRNA FGD5-AS1 facilitates osteosarcoma progression by regulating miR-124-3p/G3BP2 axis as a ceRNA.

BACKGROUND: As a skeletal malignancy, osteosarcoma has high incidence among primary malignant bone tumors. With increasing researches on molecules which mediate cancer progression, molecular mechanism has gradually become the pivot of osteosarcoma research and treatment. AIM: Our study aimed at investigating the function of G3BP stress granule assembly factor 2 (G3BP2), which is an oncogene for breast cancer (BC) and prostate cancer but remains unknown in osteosarcoma cells. METHODS: Related gene expression was confirmed by RT-qPCR. Functional assays including immunofluorescence (IF), colony formation, transferase-mediated dUTP nick-end labeling (TUNEL) as well as transwell assays were utilized to test the cell biological process caused by the genes. Meanwhile, RNA pull-down assay, along with luciferase reporter and RNA immunoprecipitation (RIP) assays, was utilized to detect the interaction G3BP2, miR-124-3p and FGD5 antisense RNA 1 (FGD5-AS1) may exert on the regulation of osteosarcoma cells. RESULTS: G3BP2 was with high expression in osteosarcoma cells, and it aggravated the malignant cell behaviors in osteosarcoma. Additionally, miR-124-3p was verified to negatively regulate G3BP2 expression in osteosarcoma cells. Moreover, lncRNA FGD5-AS1 was predicted and testified to be the sponge of miR-124-3p and modulated G3BP2 expression positively. Subsequently, FGA5-AS1 accelerated osteosarcoma cell proliferation through up-regulating G3BP2. Furthermore, we identified EBF transcription factor 1 (EBF1) as the transcription factor for FGA5-AS1, and EBF1 served as a tumor facilitator in osteosarcoma cells. CONCLUSION: EBF1 induced-FGA5-AS1 aggravated osteosarcoma cell malignancy by targeting miR-124-3p and G3BP2.

Be in Your Element: The Joint Effect of Human Resource Management Strength and Proactive Personality on Employee Creativity.

Employee creativity is fast becoming a part and parcel in the wake of the increasing volatility of the employment market and the complexity of job demands. Drawing from the actor-context interactionist theoretical approach and career construction theory, this paper adds to current research by exploring the serial mediating effect of job crafting (JC) and career adaptability (CA) in the impact of human resource management strength (HRMS) on employee creativity. Furthermore, we suggest that proactive personality interacts with HRMS to jointly influence creativity. Survey data from samples of 297 (Study 1) and 390 (Study 2) employees largely confirm our model. Our findings show that HRMS positively impacts employee creativity via serial mediation of job crafting and career adaptability, and proactive personality negatively moderates the process. The paper confirms and expands the interactionist theoretical perspective of creativity, highlights the significance of integration of contextual factors, individual characteristics, and career construction, and makes certain practical sense.

All-Inside Anterior Cruciate Ligament Reconstruction: A Review of Advance and Trends.

Anterior cruciate ligament (ACL) injury is a common disease in orthopedics and mostly occurs as a noncontact injury in athletes. Patients' knee joint stability, which is crucial to their athletic ability, cannot be restored through conservative treatment; it can only be restored through ACLR (ACL reconstruction) surgery. The surgical techniques of ACLR are constantly evolving, from bone tendon bone (BTB) grafting combined with interface screw fixation to hamstring tendon autograft or allogeneic tendon and of suspension device constructs. In particular, the currently prevalent all-inside technique featuring good cosmetic results and quick recovery of early functions not only ensures the stable fixation of grafts but also reduces surgical trauma. This review compares the advantages and disadvantages of different aspects of all-inside ACLR, including graft selection and preparation, bone socket reconstruction, fixation methods, and surgical technique effects and limitations. It has been found that the all-inside technique excels both anatomically and clinically but still requires further development. Besides, it has some limitations, and high-quality randomized controlled trials are still required to compare the long-term effects of the all-inside technique and other ACLR techniques.

The role and therapeutic potential of stem cells in skeletal muscle in sarcopenia.

Sarcopenia is a common age-related skeletal muscle disorder featuring the loss of muscle mass and function. In regard to tissue repair in the human body, scientists always consider the use of stem cells. In skeletal muscle, satellite cells (SCs) are adult stem cells that maintain tissue homeostasis and repair damaged regions after injury to preserve skeletal muscle integrity. Muscle-derived stem cells (MDSCs) and SCs are the two most commonly studied stem cell populations from skeletal muscle. To date, considerable progress has been achieved in understanding the complex associations between stem cells in muscle and the occurrence and treatment of sarcopenia. In this review, we first give brief introductions to sarcopenia, SCs and MDSCs. Then, we attempt to untangle the differences and connections between these two types of stem cells and further elaborate on the interactions between sarcopenia and stem cells. Finally, our perspectives on the possible application of stem cells for the treatment of sarcopenia in future are presented. Several studies emerging in recent years have shown that changes in the number and function of stem cells can trigger sarcopenia, which in turn leads to adverse influences on stem cells because of the altered internal environment in muscle. A better understanding of the role of stem cells in muscle, especially SCs and MDSCs, in sarcopenia will facilitate the realization of novel therapy approaches based on stem cells to combat sarcopenia.

How Challenge Demands Have Offsetting Effects on Job Performance: Through the Positive and Negative Emotions.

By combining the broaden-and-build theory of positive emotions (Fredrickson, 2001) and the transactional theory of stress (Lazarus and Folkman, 1984), this study examines how challenge demands (i.e., task complexity and time pressure) have dual effects on employees' job performance through the mediating effects of positive and negative emotions. We collected data from 414 employees from three firms located in China, including two hi-tech firms and one financial firm. The results indicated that challenge demands (i.e., task complexity and time pressure) have an overall positive effect on employees' job performance (i.e., task performance and contextual performance) by offsetting positive indirect effects with negative indirect effects. The theoretical and practical implications are also discussed.

G Protein-Coupled Receptors in Osteoarthritis: A Novel Perspective on Pathogenesis and Treatment.

G protein-coupled receptors (GPCRs) are transmembrane receptor proteins that trigger numerous intracellular signaling pathways in response to the extracellular stimuli. The GPCRs superfamily contains enormous structural and functional diversity and mediates extensive biological processes. Until now, critical roles have been established in many diseases, including osteoarthritis (OA). Existing studies have shown that GPCRs play an important role in some OA-related pathogenesis, such as cartilage matrix degradation, synovitis, subchondral bone remodeling, and osteophyte formation. However, current pharmacological treatments are mostly symptomatic and there is a paucity of disease-modifying OA drugs so far. Targeting GPCRs is capable of inhibiting cartilage matrix degradation and synovitis and up-regulating cartilage matrix synthesis, providing a new therapeutic strategy for OA. In this review, we have comprehensively summarized the structures, biofunctions, and the novel roles of GPCRs in the pathogenesis and treatment of OA, which is expected to lay the foundation for the development of novel therapeutics against OA. Even though targeting GPCRs may ameliorate OA progression, many GPCRs-related therapeutic strategies are still in the pre-clinical stage and require further investigation.

Effects of Platelet-Rich Plasma and Bone Marrow Mesenchymal Stem Cells on Meniscal Repair in the White-White Zone of the Meniscus.

OBJECTIVE: To investigate the role of autologous platelet-rich plasma (PRP) on the repair of meniscal white-white zone injury through promoting the proliferation of canine bone marrow-derived mesenchymal stem cells (BMSCs). METHODS: A total of 24 beagle dogs were selected to construct meniscal white-white zone injury models in both lateral knee joints. All subjects were divided into four groups: control, BMSCs, PRP, and PRP + BMSCs. Immunohistochemistry was applied in the expression detection of type I and type II collagens. HE staining and methylene blue staining were performed to observe the injury of cartilage of lateral femoral condyle in each group. ELISA was used to detect the osteopontin (OPN) content in cartilage of lateral femoral condyle. HE staining and magnetic resonance imaging (MRI) were used to observe the healing of meniscus in each group. Outcome measures include the expression of OPN in the synovial fluid of knee joint, the expression of type I collagen and type II collagen, the healing of meniscus injury, and the damage degree of lateral femoral condyle cartilage. RESULTS: Compared with the control group, the expressions of type I and type II collagens were enhanced in the PRP group and the PRP + BMSCs group. Compared with 1 week before modeling, the expression of OPN was elevated in the control group and the BMSCs group at 3 weeks after modeling. There were no significant differences in the above indicators between the PRP group and the PRP + BMSCs group. According to MRI and pathological section after HE staining, meniscal healing in the PRP group and the PRP + BMSCs group was significantly improved as compared to that of the control group and the BMSCs group (all P < 0.05), and there was no significant difference between the PRP group and the PRP + BMSCs group (P > 0.05). All subjects were divided into the non-healing group and the healing group in accordance with the HE staining results in previous experiment. The injury of cartilage of lateral femoral condyle was significantly heavier in the non-healing group than that in the healing group. CONCLUSION: The application of PRP alone or in combination with BMSCs could promote the clinical healing rate of meniscal white-white zone injury.

Corrigendum: My Fault? Coworker Incivility and Organizational Citizenship Behavior: The Moderating Role of Attribution Orientation on State Guilt.

[This corrects the article DOI: 10.3389/fpsyg.2021.683843.].