BACKGROUND:We have successfully established an animal model of small ear pig in southern Yunnan province with internal tension relieving technique combined with autologous Achilles tendon for anterior cruciate ligament reconstruction,and verified the stability and reliability of the model.However,whether internal tension relieving technique can promote the ligamentalization process of autologous Achilles tendon graft has not been studied. OBJECTIVE:To investigate the differences in the process of ligamentalization between conventional reconstruction and internal reduction reconstruction of the anterior cruciate ligament by gross view,histology and electron microscopy. METHODS:Thirty adult female small ear pigs in southern Yunnan province were selected.Anterior cruciate ligament reconstruction was performed on the left knee joint with the ipsilateral knee Achilles tendon(n=30 in the normal group),and anterior cruciate ligament reconstruction was performed on the right knee joint with the ipsilateral knee Achilles tendon combined with the internal relaxation and enhancement system(n=30 in the relaxation group).The autogenous right forelimb was used as the control group;the anterior cruciate ligament was exposed but not severed or surgically treated.At 12,24,and 48 weeks after surgery,10 animals were sacrificed,respectively.The left and right knee joint specimens were taken for gross morphological observation to evaluate the graft morphology.MAS score was used to evaluate the excellent and good rate of the ligament at each time point.Hematoxylin-eosin staining was used to evaluate the degree of ligament graft vascularization.Collagen fibers and nuclear morphology were observed,and nuclear morphology was scored.Ultrastructural remodeling was evaluated by scanning electron microscopy and transmission electron microscopy. RESULTS AND CONCLUSION:(1)The ligament healing shape of the relaxation group was better at various time points after surgery,and the excellent and good rate of MAS score was higher(P<0.05).Moreover,the relaxation group could obtain higher ligament vascularization score(P<0.05).(2)The arrangement of collagen bundles and fiber bundles in the two groups gradually tended to be orderly,and the transverse fiber connections between collagen gradually increased and thickened,suggesting that the strength and shape degree of the grafts were gradually improved,but the ligament remodeling in the relaxation group was always faster than that in the normal group at various time points after surgery.(3)The diameter,distribution density,and arrangement degree of collagen fibers in the relaxation group were better than those in the normal group at all time points,especially in the comparison of collagen fiber diameter between and within the relaxation group(P<0.05).

Arginine methylation is a critical post-translational modification that plays multifaceted biological functions. However, the manipulation of protein arginine methylation largely depends on genetic or pharmaceutic inhibition of the regulatory enzymes, protein arginine methyltransferases (PRMTs), or non-methylation substitution of corresponding arginine residue to lysine or alanine of protein of interest (POI), which inevitably affects other substrates, or disrupts the structure of POI. Thus, it urges an approach to specifically modulate the arginine methylation of a POI under physiological conditions. To this end, we report the discovery of a methylation tagging system (MeTAG), that enables targeted modification of protein arginine methylation. Through bridging the methyltransferase PRMT5 proximity to a POI, MeTAG facilitates the arginine methylation of POIs, including known arginine methylated proteins, androgen receptor (AR) and protein kinase B (AKT), as well as a neo-substrate E1A binding protein (p300), in a reversible and PRMT5-dependent manner. Moreover, MeTAG can regulate downstream signaling in a methylation dependent manner, leading to downregulation of PSMA mRNA level and activation of AKT. Therefore, MeTAG represents a feasible approach to modulate protein methylation and thereby perturbs protein function in biological and therapeutic contexts.

BACKGROUND:Currently,there have been studies on the regulatory mechanism of lncRNA\miRNA\mRNA co-expression network on the occurrence and development of osteoarthritis.Our research group has screened qualified NONHSAT248596.1 and miR-146a-5p through the database in the previous stage,but the corresponding in vivo experiments to verify the above regulatory mechanisms are still lacking. OBJECTIVE:To explore the role of NONHSAT248596.1 in regulating competitive endogenous RNA of miR-146a-5p in cartilage degeneration mediated by stromal cell derived factor type 1/chemokine receptor 4 axis in vivo. METHODS:The models of osteoarthritis were established in 36 New Zealand rabbits by injecting stromal cell derived factor 1 solution into the knee joint of the right hind limb.According to the random number table method,they were divided into four groups.lncRNA group,miRNA group,ceRNA group and control group were injected with lentivirus vector overexpressing NONHSAT248596.1,lentivirus vector overexpressing miR-146a-5p,lentivirus vector overexpressing miR-146a-5p+NONHSAT248596.1 and empty lentivirus vector into the molded knee joint,respectively.At 4,8 and 12 weeks of modeling,cartilage tissues and subchondral bone tissues of the knee joint were taken for relevant detection. RESULTS AND CONCLUSION:Hematoxylin-eosin staining and safranin fast green staining showed different degrees of degeneration in the four groups.At 4 weeks,the cartilage tissue of the lncRNA group showed swelling of chondrocytes,loss of cell polarity,destruction of extracellular matrix,surface erosion,fracture formation and partial or full layer loss of cartilage tissue.The degree of cartilage injury was gradually aggravated with time.The progression of articular cartilage inflammation in the miRNA group was the slowest among the four groups.qRT-PCR showed that at the same time point,mRNA expression levels of NONHSAT248596.1,chemokine receptor 4,matrix metalloproteinase 3,matrix metalloproteinase 9 and matrix metalloproteinase 13 in cartilage tissue of the lncRNA group were higher than those of the other three groups(P＜0.05).The mRNA expression levels of miR-146a-5p,aggrecan and type Ⅱ collagen were lower than those of the other three groups(P＜0.05).The mRNA expression levels of NONHSAT248596.1,chemokine receptor 4,matrix metalloproteinase 3,matrix metalloproteinase 9 and matrix metalloproteinase 13 in the miRNA group were lower than those in the ceRNA group and control group at 8 and 12 weeks after the model construction(P＜0.05).The mRNA expressions of miR-146a-5p,aggrecan and type Ⅱ collagen were higher than those of the ceRNA group and control group(P＜0.05).Western blot assay showed that at the same time point,the expression levels of aggrecan and type Ⅱ collagen in cartilage tissue of the lncRNA group were always lower than those of the other three groups(P＜0.05).The expression levels of aggrecan and type Ⅱ collagen in cartilage tissue of the miRNA group at 8 and 12 weeks after modeling were higher than those of the ceRNA group and control group(P＜0.05).The results showed that miR-146a-5p,as the target of NONHSAT248596.1,could be inhibited by the effect of its ceRNA.After acting on miR-146a-5p,NONHSAT248596.1 regulates the stromal cell derived factor type 1/chemokine receptor 4 axis to affect the expression of matrix metalloprotein,type Ⅱ collagen,and aggrecan in osteoarthritis chondrocytes,resulting in the degradation of extracellular matrix and the loss of proteoglycan.

BACKGROUND:In recent years,some scholars in the field of tendon bone injury have attached stromal cell-derived factor 1 to tissue engineering scaffolds to promote tendon bone healing,and achieved good results.However,whether stromal cell-derived factor 1 promotes tendon bone healing mechanisms and participates in the repair of natural healing has not yet been defined. OBJECTIVE:To study the expression of stroma-cell derived factor 1 during tendon bone healing after rupture of the whole supraspinatus muscle of the rabbit rotator cuff and its migration effect and optimal in vitro migration promoting concentration on stem cells during tendon bone injury. METHODS:Totally 18 adult New Zealand rabbits were randomly selected to establish rotator cuff injury models,and an additional 3 rabbits were selected as blank controls.At 3,5,7,14,21,and 28 days after modeling,three rabbits were executed separately and the rabbits in the blank group were sacrificed.The tissues of tendon bone junction were taken and stored in a-80℃refrigerator.The expression of stromal cell-derived factor 1 was detected by ELISA at each time point after injury.Mesenchymal stem cells were isolated from the bone marrow of young rabbit femur,cultured,and identified.Transwell assay was performed to verify the migration-promoting effect of stromal cell-derived factor 1 on stem cells and the optimal migration-promoting concentration in vitro.The stem cells cultured to P3 were co-cultured with BrdU and injected into the rabbit ear marginal vein,and immunohistochemical staining was used to verify whether the stem cells migrated to the injury site. RESULTS AND CONCLUSION:(1)Stromal cell-derived factor 1 gene expression was bimodal during rotator cuff tendon bone healing.Stromal cell-derived factor 1 gene expression increased significantly at 3 days post-injury(P<0.01)and then decreased,reaching a minimum at 5 days post-injury.It increased again and reached a peak 14 days after injury(P<0.01)and then decreased.(2)Cell immunohistochemical staining displayed that stem cells labeled with BrdU did migrate to the injury site.(3)The results of the transwell experiment exhibited that 60-80 ng/mL stromal cell-derived factor 1 had the best effect on promoting migration of stem cells,while a concentration of 200 ng/mL inhibited migration.(4)Stromal cell-derived factor 1 is involved in the healing of rotator cuff tendon bone during the inflammatory response phase and the proliferation phase.The mechanism of action may be to promote the migration of stem cells to the injury and their differentiation into various types of cells to promote repair.In addition,the pro-migration effect of stromal cell-derived factor 1 exists at a range of concentrations,beyond which it may act as an inhibitor.

BACKGROUND:As a dominant breed pig in southwest China,the southern Yunnan small-ear pig has been widely used as an experimental animal in the basic research of other disciplines,but there are still no reports on its application in anterior cruciate ligament reconstruction. OBJECTIVE:To establish a large animal model of the southern Yunnan small-ear pig with anterior cruciate ligament with autologous Achilles tendon was established. METHODS:Twenty adult female Yunnan small-ear pigs were equally randomized into two groups.In the autologous Achilles tendon group,the right knee anterior cruciate ligament was reconstructed with autologous Achilles tendon as a graft,while in the sham-operated group,a similar operation was performed on the right knee without any treatment of the anterior cruciate ligament.General conditions of each pig were observed and recorded before and 12 months after surgery.Ligaments and grafts were taken for gross observation and MAS scoring.Hematoxylin-eosin staining was performed to observe morphological characteristics of ligaments.The staining and arrangement of type I and type Ⅲ collagen were evaluated by immunohistochemistry.Transmission electron microscopy was used to observe the type,size,diameter,ratio,and distribution of collagen fibers in ligaments. RESULTS AND CONCLUSION:All animals had normal diet and activity,good wound healing,no obvious inflammatory reaction,no local purulent infection,and no significant changes in mental and urinary conditions compared with those before surgery.The reconstructed cruciate ligament of the knee was intact,with no stiffness and normal range of motion.Both the anterior drawer and Lachman tests were negative.Gross observation of the graft:12 months after surgery,the grafts was in good position,with good integrity,obvious tension,ligament color close to the original anterior cruciate ligament,and complete surface synovial coverage.Most of the intraarticular ligaments in the autologous Achilles tendon group were defined as MAS I type and a few were defined as MAS Ⅱ type.In the sham-operated group,the intraarticular ligament was defined as MAS I type.Hematoxylin-eosin staining indicated that,12 months after surgery,collagen fibers in the autologous Achilles tendon group began to appear bundled,isotropic,and uniformly arranged,with more obvious isotropic corrugations,and the nuclei were mainly linear or spindle-shaped,which were similar to those in normal anterior cruciate ligament tissue of the sham-operated group.Immunohistochemistry results indicated that,12 months after surgery,there was a higher expression of type I collagen and significantly less expression of type Ⅲ collagen in the reconstructed anterior cruciate ligament in the autologous Achilles tendon group.The degree of type I and type Ⅲ staining was similar in the two groups.Under the transmission electron microscope,the diameter,arrangement and density of collagen fibers in the reconstructed anterior cruciate ligament of the autologous Achilles tendon group were similar to those of the original anterior cruciate ligament at 12 months after surgery,indicating that the ligament remodeling process had been basically completed in the autologous Achilles tendon group at 12 months after surgery.Through a comprehensive evaluation of animal general conditions,ligament general view,MAS score,hematoxylin-eosin staining,immunohistochemistry,and transmission electron microscopy observation,we successfully established a large animal model of anterior cruciate ligament reconstruction using autogenous Achilles tendon in southern Yunnan small-ear pigs,with good morphological,histological and ultrastructural results.

Parkinson′s disease is a common clinical degenerative disease of the nervous system, and rapid eye movement sleep behavior disorder (RBD) is a common sleep symptom of patients with Parkinson′s disease. This article reviews the pathogenesis, epidemiology, clinical characteristics, imaging manifestations, clinical evaluation and treatment of RBD in patients with Parkinson′s disease, in order to deepen the understanding of RBD in patients with Parkinson′s disease.

Objective This paper aims to evaluate the effectiveness of the Plan Do Check Act(PDCA)cycle in the quality improvement of medical device adverse event report forms to provide references for developing improvement strategies.Methods This study randomly selected 271 report forms from hospitals in Guangdong Province from January 1,2022,to March 31,2022 as the pre-implementation group.Another 462 report forms from January 1,2023,to March 31,2023 were randomly selected after implementing the PDCA cycle as the post-implementation group.The effect evaluation was concluded by comparing the average score on quality assessment of report forms between the two groups from 21 cities in Guangdong Province.Results The post-implementation group showed significantly higher overall average score on quality assessment as compared to the pre-im-plementation group(P＜0.05).After the implementation,the form completions on medical devices,adverse events,and usage,were significantly improved(P＜0.05).Conclusion The PDCA cycle can effectively improve the quality of medical device ad-verse event report forms,which is significant for standardizing the monitoring of medical device adverse events and subsequent in-vestigation and resolution of risk.

Background: Long coronavirus disease 2019 (COVID-19) in recovered patients (RPs) is gradually recognized by more people. However, how long it will last and the underlining mechanism remains unclear. Methods: We conducted a prospective follow-up study to evaluate the long-term symptoms and clinical indices of RPs at one-year after discharge from Union Hospital, Wuhan, China between December 2020 to May 2021. We also performed the 16S rRNA sequencing of stool samples from RPs and healthy controls (HCs) and analyzed the correlation between the gut microbiota and long COVID-19. Results: In total, 187 RPs were enrolled, among them, 84 (44.9%) RPs reported long COVID-19 symptoms at one-year after discharge. The most common long-term symptoms were cardiopulmonary symptoms, including chest tightness after activity (39/187, 20.9%), palpitations on exercise (27/187, 14.4%), sputum (21/187, 11.2%), cough (15/187, 8.0%) and chest pain (13/187, 7.0%), followed by systemic symptoms including fatigue (34/187, 18.2%) and myalgia (20/187, 10.7%), and digestive symptoms including constipation (14/187, 7.5%), anorexia (13/187, 7.0%), and diarrhea (8/187, 4.3%). Sixty-six (35.9%) RPs presented either anxiety or depression (42/187 [22.8%] and 53/187 [28.8%] respectively), and the proportion of anxiety or depression in the long symptomatic group was significantly higher than that in the asymptomatic group (41/187 [50.6%] vs. 25/187 [24.3%]). Compared with the asymptomatic group, scores of all nine 36-Item Short Form General Health Survey domains were lower in the symptomatic group (all P < 0.05). One hundred thirty RPs and 32 HCs (non-severe acute respiratory syndrome coronavirus 2 infected subjects) performed fecal sample sequencing.Compared with HCs, symptomatic RPs had obvious gut microbiota dysbiosis including significantly reduced bacterial diversities and lower relative abundance of short-chain fatty acids (SCFAs)-producing salutary symbionts such as Eubacterium_hallii_group, Subdoligranulum, Ruminococcus, Dorea, Coprococcus, and Eubacterium_ventriosum_group. Meanwhile, the relative abundance of Eubacterium_hallii_group, Subdoligranulum, and Ruminococcus showed decreasing tendencies between HCs, the asymptomatic group, and the symptomatic group. Conclusion This study demonstrated the presence of long COVID-19 which correlates with gut microbiota dysbiosis in RPs at one-year after discharge, indicating gut microbiota may play an important role in long COVID-19.

Objective:To compare the clinical efficacies between arthroscopic anatomic single bundle reconstruction of posterior cruciate ligament (PCL) assisted by internal tension relieving technique combined with rapid rehabilitation and anatomic single bundle reconstruction combined with conventional rehabilitation in the treatment of PCL rupture.Methods:A retrospective cohort study was used to analyze the clinical data of 88 patients with PCL rupture admitted to First Affiliated Hospital of Kunming Medical University from September 2016 to September 2020. The patients included 65 males and 23 females, aged 18-55 years [(39.3±10.8)years]. Forty-four patients underwent arthroscopic anatomic single bundle reconstruction of PCL assisted by internal tension relieving technique combined with rapid rehabilitation therapy (tension-relieving group), and 44 patients underwent arthroscopic routine anatomic single bundle reconstruction of PCL combined with conventional rehabilitation (traditional group). The two groups were compared before and at 3, 12, and 24 months after surgery regarding the following items: International Knee Literature Committee (IKDC) score, Hospital for Special Surgery (HSS) score, Lysholm score, knee motion cycle (maximum stride length, minimum stride length, and stride frequency) and 6 kinematic indicators (angle of forward and back extension, angle of internal and external rotation, angle of internal and external rotation, up and down displacement, internal and external displacement, and forward and back displacement). The Marburger arthroscopy score (MAS) and Professor Ao Yingfang′s improved score by secondary arthroscopy were compared between the two groups at 12 months after surgery. The perioperative complications were observed.Results:All patients were followed for 24-36 months [(25.5±6.3)months]. In tension-relieving group and the traditional group, the values of IKDC score were (71.8±9.8)points and (68.5±6.5)points at 3 months after surgery, (87.6±6.0)points and (87.6±5.5)points at 12 months after surgery, and (95.5±3.1)points and (92.8±11.6)points at 24 months after surgery, respectively. The values were gradually increased, significantly higher than those before surgery [(48.1±16.9)points and (47.1±15.0)points] (all P<0.05). There were no significant differences between the two groups at each time point (all P>0.05). In tension-relieving group and the traditional group, the values of HSS score were (74.2±6.2)points and (68.4±9.5)points at 3 months after surgery, (91.9±5.4)points and (88.4±4.7)points at 12 months after surgery, and (97.1±2.0)points and (96.2±2.8)points at 24 months after surgery, respectively. The values of HSS score gradually increased, significantly higher than those before surgery [(57.5±17.7)points and (56.8±14.3)points] (all P<0.05). At 3 and 12 months after surgery, the values of HSS score in the tension-relieving group were significantly higher than those in the traditional group (all P<0.05), but others were not significantly different between the two groups (all P>0.05). In tension-relieving group and the traditional group, the values of Lysholm score were (74.2±14.9)points and (70.3±7.5)points at 3 months after surgery, (90.9±6.1)points and (88.7±4.7)points at 12 months after surgery, and (96.9±3.0)points and (96.3±2.8)points at 24 months after surgery, respectively. The values of Lysholm score were gradually increased, significantly higher than those before operation [(48.7±20.7)points and (48.2±19.9)points] (all P<0.05). There were no significant differences between the two groups at any time points (all P>0.05). At 3, 12, and 24 months after surgery, the motion cycle (maximum stride length, minimum stride length and stride frequency) and 6 kinematic indicators (angle of forward bending and backward extension, angle of internal and external rotation, angle of internal and external rotation, internal and external displacement, up and down displacement, and forward and backward displacement) of knee joint were significantly improved in both groups compared with those before surgery (all P<0.05). At 3, 12, and 24 months after surgery, the forward and backward displacement in the tension-relieving group was significantly decreased than that in the traditional group (all P<0.05), but others were not significantly different between the two groups (all P>0.05). The MAS was rated as excellent to good in 14 patients and fair to poor in 2, with the excellent and good rate of 87.5% (14/16) in the tension-relieving group, while the score was rated as excellent to good in 11 patients and fair to poor in 3, with the excellent and good rate of 78.6% (11/14) in the traditional group ( P>0.05). The Professor Ao Yingfang′s improved score was (10.6±1.5)points in the tension-relieving group, markedly higher than that in the traditional group [(9.6±2.3)points] ( P<0.05). No perioperative complications were observed. Conclusion:Compared with anatomic single bundle reconstruction combined with conventional rehabilitation, arthroscopic anatomic single bundle reconstruction of PCL assisted by internal tension relieving technique combined with rapid rehabilitation have higher subjective function score, better anteroposteric stability during knee movement, and better results of secondary microscopy.

Objective:We evaluated frailty in elderly hospitalized patients with atrial fibrillation and analyzed the relevance, consistency, and diagnostic power of different frailty tools.Methods:From September 2018 to April 2019, a total of 197 elderly patients with atrial fibrillation aged ≥ 65 years in Beijing Hospital, Chinese PLA General Hospital, and Beijing Tsinghua Changgung Hospital were prospectively enrolled.Five frailty tools, including the clinical frailty scale(CFS), FRAIL scale(FRAIL), Fried frailty phenotype(Fried), Edmonton frail scale(EFS), and comprehensive geriatric assessment-frailty index(CGA-FI), were used for frailty assessment.Results:A total of 197 hospitalized elderly patients with atrial fibrillation were enrolled, with an average age of(77.5±7.1)years old(57.4% male). The prevalence of frailty, according to the five frailty tools, were 25.4%(FRAIL), 27.9%(EFS), 34.5%(Fried), 40.6%(CFS), and 42.6%(CGA-FI), respectively.CFS had a good correlation(correlation coefficient 0.80)and and consistency(Kappa value 0.71, 95% CI 0.61~0.81)with CGA-FI.The combined frailty index was used as the gold standard for frailty diagnosis.The results showed that CFS and CGA-FI had high diagnostic sensitivity(95.9 % and 98.0 %, respectively)and specificity(77.7 % and 75.7 %, respectively). Conclusions:Frailty is common in elderly hospitalized patients with atrial fibrillation, showing multidimensional features, and physical weakness is not prominet.CFS and CGA-FI are recommended for the assessment of frailty in patients with atrial fibrillation, which had good correlation and consistency.