BACKGROUND:Tendinopathy is a musculoskeletal disorder characterized by pain and decreased mobility,with pathological changes of disturbed collagen and hyperplasia of the vasculature.Tendinopathy tends to occur in athletes,physical workers,and the elderly.One of the mechanisms of tendinopathy is the"failed healing response",and part of what causes the failed healing response is the erroneous differentiation of tendon stem/progenitor cells. OBJECTIVE:By reviewing the relevant literature,we introduce the characteristics of tendon stem/progenitor cells,summarize the factors that affect the differentiation of tendon stem/progenitor cells to tendon cells and those that lead to mis-differentiation of tendon stem/progenitor cells(differentiation to adipocytes,osteocytes and chondrocytes),and also describe the limitations of tendon stem/progenitor cells in clinical applications. METHODS:PubMed and Web of Science databases were searched for the terms"tendon stem/progenitor cells,tendinopathy,tendon injury,differentiation".The relevant literature was screened by reading and 109 articles were included for the analysis of the results. RESULTS AND CONCLUSION:(1)Tendon stem/progenitor cells are a type of stem cells that can spontaneously differentiate into tendons and have the ability to self-renew,clone,and multi-differentiate.Various external conditions acting on tendon stem/progenitor cells can lead them to differentiate in diverse directions.The specific factors that regulate the fate of tendon stem/progenitor cells are not known with certainty.When stem cell renewal and differentiation in tendons becomes abnormal,it can lead to failure of tendon healing and consequently to tendinopathy.(2)Aging,changes in extracellular matrix composition,excessive mechanical stimulation,prostaglandin E2 and interleukin-6 as well as interleukin-10 and some systemic diseases may be important in regulating the mis-differentiation of tendon stem/progenitor cells.(3)Possible favorable factors that promote the differentiation of tendon stem/progenitor cells to tenocytes are:some growth factors and cytokines,moderate mechanical stimulation and topography of the extracellular matrix,low oxygen tension,drugs,and several transcriptional genes and proteins.(4)The most desirable therapeutic tools are the regulation of endogenous tendon stem/progenitor cells or the stimulation of endogenous tendon stem/progenitor cell proliferation and differentiation by exogenous tendon stem/progenitor cells.(5)Understanding the factors that regulate mis-differentiation of tendon stem/progenitor cells may provide insight into the pathogenesis of tendinopathy and identify therapeutic targets.Elaborating on the induction of tendon stem/progenitor cell differentiation into tendons could facilitate their use in tissue engineering.

Objective:To explore the impact of sleep duration, physical exercise, and their interactions on the risk of dyslipidemia in older adults aged ≥80 (the oldest old) in China.Methods:The study subjects were the oldest old from four rounds of Healthy Aging and Biomarkers Cohort Study (2008-2009, 2011-2012, 2014 and 2017-2018). The information about their demographic characteristics, lifestyles, physical examination results and others were collected, and fasting venous blood samples were collected from them for blood lipid testing. Competing risk model was used to analyze the causal associations of sleep duration and physical exercise with the risk for dyslipidemia. Restricted cubic spline (RCS) function was used to explore the dose-response relationship between sleep duration and the risk for dyslipidemia. Additive and multiplicative interaction model were used to explore the interaction of sleep duration and physical exercise on the risk for dyslipidemia.Results:The average age of 1 809 subjects was (93.1±7.7) years, 65.1% of them were women. The average sleep duration of the subjects was (8.0±2.5) hours/day, 28.1% of them had sleep duration for less than 7 hours/day, and 27.2% had sleep for duration more than 9 hours/day at baseline survey. During the 9-year cumulative follow-up of 6 150.6 person years (follow-up of average 3.4 years for one person), there were 304 new cases of dyslipidemia, with an incidence density of 4 942.6/100 000 person years. The results of competitive risk model analysis showed that compared with those who slept for 7-9 hours/day, the risk for dyslipidemia in oldest old with sleep duration >9 hours/day increased by 22% ( HR=1.22, 95% CI: 1.07-1.39). Compared with the oldest old having no physical exercise, the risk for dyslipidemia in the oldest old having physical exercise decreased by 33% ( HR=0.67, 95% CI: 0.57-0.78). The RCS function showed a linear positive dose-response relationship between sleep duration and the risk for hyperlipidemia. The interaction analysis showed that physical exercise and sleep duration had an antagonistic effect on the risk for hyperlipidemia. Conclusion:Physical exercise could reduce the adverse effects of prolonged sleep on blood lipids in the oldest old.

Objective To explore the effects of wogonin on cognitive function and neuroinflamma-tion in VaD rats by regulating AMPK/SIRT1 pathway.Methods 90 VaD rats were randomly di-vided into model group,low-,medium-and high-dose wogonin groups(50,100,200 mg/kg),and high dose+AMPK inhibitor(20 mg/kg)group,18 animals per group.Another 18 normal rats served as sham operation group.ELISA was utilized to measure the contents of IL-1β,TNF-α and IL-6 in hippocampal tissues.Western blotting was conducted to detect the expression of Iba-1,p-AMPK,AMPK and SIRT1 in hippocampal tissues.Results Compared with the sham operation group,the model group had longer escape latency,and elevated contents of IL-1β,TNF-α and IL-6,number of Iba-1 positive cells and expression level of Iba-1 protein in hippocampal tissue,shorter stay time at original platform,and lower expression of p-AMPK/AMPK and SIRT1 in hippocampal tissues(P＜0.05).Treatment of three doses of wogonin,in a dose-dependent man-ner,reduced escape latency,and decreased levels of IL-1β,TNF-α and IL-6,number of Iba-1 posi-tive cells and expression of Iba-1 protein in hippocampal tissue,but longer stay time at original platform,and enhanced expression of p-AMPK/AMPK and SIRT1 protein in hippocampal tissue when compared with the model group(P＜0.05).The high dose+AMPK inhibitor group showed longer escape latency(47.64±5.39 s vs 26.45±3.27 s),shorter stay time at original platform(21.78±3.51 s vs 35.22±5.02 s),increased levels of IL-1β,TNF-α and IL-6,number of Iba-1 positive cells and expression of Iba-1 protein in hippocampal tissue,and lower expression levels of p-AMPK/AMPK and SIRT1 in hippocampal tissue when compared with the high-dose group(P＜0.05).Conclusion Wogonin may improve cognitive function and hippocampal tissue patho-logical damage in VaD rats by activating the AMPK/SIRT1 pathway,and inhibit neuroinflammation.

Objectives:To compare the biomechanical effects on the cervical spine between the insertion of a cervical interfacet self-locking cage(CILC)for anterior cervical interbody fusion and the insertion of a Zero-profile anterior cervical interbody fusion device(Zero-P)through the finite element method.Methods:Extracting the thin-layer cervical CT scan data of a 24-year-old male volunteer,and excluding any history of cervical spine trauma,surgery,cervical spondylosis,and imaging-diagnosed cervical spine deformities.Establishing a three-dimensional finite element model(blank model)of the normal lower cervical spine.The validity of the model was verified by comparing the range of motion(ROM)with those reported in previous studies.Based on this model,finite element models were constructed for single-segment posterior CILC insertion and fusion and Zero-P insertion and fusion.The surgical segment was set as the C4/5 segment,and CILC and Zero-P were implanted respectively to fuse and construct model.The lower endplate of the C7 vertebral body was fixed,and an axial load of 73.6N was applied to simulate the head's weight.A 1.0N·m torque was applied to the upper surface of the C2 vertebral body to simulate the overall movement of the C2-C7 finite element models,including flexion,extension,lateral bending,and axial rotation.The ROM of the segment and the stress changes in the adjacent segment intervertebral discs and facet joints were analyzed in all four motion directions for the blank model,CILC model,and Zero-P model.Results:The ROMs of the established three-dimensional finite element model of the lower cervical spine in all motion directions were consistent with previously published studies,therefore its validity was verified.Compared with the blank mod-el,the ROMs in all directions of the fusion segment was significantly reduced in both the CILC and Zero-P models.The ROM of the adjacent segments and the peak stress in the intervertebral discs and facet joints of the adjacent segments were higher in all motion directions compared with the blank model,with no significant difference in the degree of ROM increase between the CILC and Zero-P models.The peak stress increase in the intervertebral discs of adjacent segments in the CILC model was smaller than that in the Zero-P model.In the CILC model,the peak stress values of the C3/4 segment during flexion,extension,lateral bending,and rotation increased from pre-fixation values of 2.181,3.358,3.636,and 3.950MPa to post-fixation values of 2.532,3.881,4.463,and 4.917MPa,respectively.The peak stress values of the C5/6 segment during flexion,extension,lateral bending,and rotation increased from pre-fixation values of 1.558,3.996,3.778,and 3.660 MPa to post-fixation values of 1.864,4.131,4.183,and 4.266MPa,respectively.In the Zero-P model,the peak stress values of the C3/4 segment during flexion,extension,lateral bending,and rotation increased from preoperative values of 2.181,3.358,3.636,and 3.950MPa to 2.977,4.241,4.654,and 5.509MPa,respectively.The peak stress values of the C5/6 segment during flexion,extension,lateral bending,and rotation increased from pre-fixation values of 1.558,3.996,3.778,and 3.660MPa to post-fixation values of 2.314,5.214,4.469,and 4.739MPa,respectively.The peak stress increase in the adjacent facet joints in all motion directions was greater in the CILC model than in the Zero-P model.Conclusions:CILC insertion results in less impact on adjacent segment disc stress compared to Zero-P and provides reliable fixation,making it a suitable option for treating adjacent segment disease after cervical surgery.

OBJECTIVES: The magnesium depletion score (MDS) is considered more reliable than traditional approaches for predicting magnesium deficiency in humans. We explored the associations of MDS and dietary magnesium intake with diabetes. METHODS: We obtained data from 18,853 participants in the National Health and Nutrition Examination Survey 2011-2018. Using multivariate regression and stratified analysis, we investigated the relationships of both MDS and magnesium intake with diabetes. To compute prevalence ratios (PRs), we employed modified Poisson or log-binomial regression. We characterized the non-linear association between magnesium intake and diabetes using restricted cubic spline analysis. RESULTS: Participants with MDS ≥2 exhibited a PR of 1.26 (95% confidence interval [CI], 1.19 to 1.34) for diabetes. Per-standard deviation (SD) increase in dietary magnesium intake was associated with a lower prevalence of diabetes (PR, 0.91; 95% CI, 0.87 to 0.96). Subgroup analyses revealed a positive association between MDS ≥2 and diabetes across all levels of dietary magnesium intake, including the lowest (PR, 1.35; 95% CI, 1.18 to 1.55), middle (PR, 1.23; 95% CI, 1.12 to 1.35), and highest tertiles (PR, 1.25; 95% CI, 1.13 to 1.37; pinteraction<0.001). Per-SD increase in magnesium intake was associated with lower diabetes prevalence in participants with MDS <2 (PR, 0.92; 95% CI, 0.87 to 0.98) and those with MDS ≥2 (PR, 0.91; 95% CI, 0.84 to 0.98; pinteraction=0.030). CONCLUSIONS MDS is associated with diabetes, particularly among individuals with low magnesium intake. Adequate dietary magnesium intake may reduce diabetes risk, especially in those with high MDS.

Despite growing prevalence and incidence, the management of gout remains suboptimal. The intermittent nature of the gout makes the long-term urate-lowering therapy (ULT) particularly important for gout management. However, patients are reluctant to take medication day after day to manage incurable occasional gout flares, and suffer from possible long-term toxicity. Therefore, a safe and easy-to-operate drug delivery system with simple preparation for the long-term management of gout is very necessary. Here, a chitosan-containing sustained-release microneedle system co-loaded with colchicine and uricase liposomes were fabricated to achieve this goal. This microneedle system was confirmed to successfully deliver the drug to the skin and maintain a one-week drug retention. Furthermore, its powerful therapeutic potency to manage gout was investigated in both acute gouty and chronic gouty models. Besides, the drug co-delivery system could help avoid long-term daily oral colchicine, a drug with a narrow therapeutic index. This system also avoids mass injection of uricase by improving its stability, enhancing the clinical application value of uricase. In general, this two-drug system reduces the dosage of uricase and colchicine and improves the patient's compliance, which has a strong clinical translation.

Objective To investigate the impact of usnic acid on neuronal necroptosis in rats with cerebral infarction by regulating the receptor-interacting protein kinase 1(RIPK1)/receptor-interacting protein kinase 3(RIPK3)/mixed lineage kinase domain-like protein(MLKL)signaling pathway.Methods The rat model of cerebral infarction was established by middle cerebral artery occlusion and reperfusion(MCAO/R).The successfully modeled rats were divided into model group,NEC-1(RIP1 inhibitor)group,low-,medium-,and high-dose of usnic acid groups,with 20 rats in each group.Another 20 rats were selected as a sham-operation group.After 3 days of drug intervention,the modified Neurological Severity Scale(mNSS)was applied to evaluate the degree of neurological damage of rats in each group.TTC staining was applied to detect the volume of cerebral infarction.HE staining was selected to observe pathological damage in brain tissue.PI/NeuN staining was selected to observe neuronal necrosis.RT-qPCR was used to detect mRNA levels of RIPK1,RIPK3 and MLKL in rat ischemic brain tissue.Western Blot was used to determine the expressions of RIPK1/RIPK3/MLKL signaling pathway related proteins in rat ischemic brain tissue.Results Compared with the sham-operation group,the neural cells in the model group showed structural damage,cell disrupted,deformation,and nuclear pyknosis,furthermore,the mNSS score,the cerebral infarction volume,proportion of PI-positive neurons were significantly increased(P＜0.05).The mRNA levels of RIPK1,RIPK3,MLKL in brain tissue,ratio of p-RIPK1/RIPK1,and the levels of RIPK3 and MLKL proteins were obviously increased(P＜0.05).Compared with the model group,the damage degree of neurocyte morphology in the low-,medium-,and high-dose of usnic acid groups was gradually alleviated,the nuclear membrane was gradually became clear,and the cell body was gradually returned to normal.The neurocyte morphology in the NEC-1 group was basically intact,and the nuclear membrane was basically clear.The mNSS score,cerebral infarction volume and proportion of PI-positive neurons in NEC-1 group and usnic acid groups were significantly decreased(P＜0.05).The mRNA levels of RIPK1,RIPK3,MLKL,ratio of p-RIPK1/RIPK1,and levels of RIPK3 and MLKL proteins in brain tissue were obviously reduced in usnic acid groups and NEC-1 group.Also,there was dose-dependent decrease in usnic acid groups(P＜0.05).No statistically obvious difference was found between the high-dose usnic acid group and the NEC-1 group(P＞0.05).Conclusion Usnic acid inhibits neuronal necroptosis in rats with cerebral infarction by inhibiting the RIPK1/RIPK3/MLKL signaling pathway,thereby alleviating brain injury in rats with cerebral infarction.

Objective:To analyze the epidemiological characteristics and genotypes of human rhinovirus (HRV) in patients with upper respiratory tract infection in Qingdao in the winter of 2020.Methods:Throat swab samples were collected from 101 patients with upper respiratory tract infection in Qingdao from November 2020 to January 2021. Quantitative PCR was used to detect 15 common respiratory viruses in the samples. HRV-positive samples were further analyzed with RT-PCR to amplify and sequence HRV VP4/VP2 gene. A phylogenetic tree was constructed based on the sequencing results and homology analysis was conducted.Results:Six common respiratory viruses were detected in the 101 patients. Thirty-four cases (34/101, 33.66%) were single pathogen infection and two cases were multiple infection (2/101, 1.98%). The positive rate of HRV was the highest (21.78%, 22/101). Twenty HRV VP4/VP2 sequences were successfully amplified. Phylogenetic analysis showed that there were 16 strains of HRV-A subtype and four strains of HRV-C subtype and 14 serotypes were involved.Conclusions:HRV was one of the leading viral pathogens causing upper respiratory tract infection in Qingdao in the winter of 2020 and the predominant subtype was HRV-A.

Nanoparticulate drug delivery systems (Nano-DDSs) have emerged as possible solution to the obstacles of anticancer drug delivery. However, the clinical outcomes and translation are restricted by several drawbacks, such as low drug loading, premature drug leakage and carrier-related toxicity. Recently, pure drug nano-assemblies (PDNAs), fabricated by the self-assembly or co-assembly of pure drug molecules, have attracted considerable attention. Their facile and reproducible preparation technique helps to remove the bottleneck of nanomedicines including quality control, scale-up production and clinical translation. Acting as both carriers and cargos, the carrier-free PDNAs have an ultra-high or even 100% drug loading. In addition, combination therapies based on PDNAs could possibly address the most intractable problems in cancer treatment, such as tumor metastasis and drug resistance. In the present review, the latest development of PDNAs for cancer treatment is overviewed. First, PDNAs are classified according to the composition of drug molecules, and the assembly mechanisms are discussed. Furthermore, the co-delivery of PDNAs for combination therapies is summarized, with special focus on the improvement of therapeutic outcomes. Finally, future prospects and challenges of PDNAs for efficient cancer therapy are spotlighted.

OBJE CTIVE To inv estigate the antibiotic use and rationality for children in community health service institutions from Beijing ，and to provide reference for promoting rational use of antibiotics in primary healthcare institutions. METHODS All the prescriptions for children from primary healthcare institutions in 2019 were extracted from prescription review system of community health service institutions in Beijing. The use of antibiotics was described according to the related indicators of the World Health Organization/International Network for Rational Use of Drug （WHO/INRUD）. The structure of antibiotics use was analyzed according to the anatomical therapeutic chemical （ATC）classification as well as the WHO AWaRe classification and diagnosis. RESULTS A total of 288 primary healthcare institutions and 10 422 prescriptions for children were included. The number of institutions in high-income areas ，middle-income areas and low-income areas were 119，80 and 89 respectively，and the number of prescriptions involved were 2 430，2 163 and 5 829 respectively，including 1 447 prescriptions involving antibiotics （13.9％）. Among 1 447 prescriptions，the rate of prescriptions involving combined use of antibiotics was 1.4％（20 pieces）；the rate of prescriptions involving antibiotics injection was 9.7％（141 pieces）；4.8％ antibiotics prescriptions were rated as unreasonable （69 pieces）. The three most commonly used antibiotics were the macrolides （40.2％），the second-generation cephalosporins （26.5％） and the third-generati on cephalosporins （23.4％）. The proportion of antibioti cs prescriptions from groups of access ，caution， reserve and not recommended were 9.1％，92.1％，0.3％，and 0， respectively. The rate of antibiotics prescriptions fortonsillitis was the highest （31.9％ ）. Among 69 irrationalantibiotics prescriptions ，main of them were irrational drug use （56 pieces，81.2％）. CONCLUSIONS The rate of antibiotics prescriptions for children in primary healthcare institutions from Beijing is lower than the standard of WHO antibiotics prescription rate （20.0％-26.8％），but the use rate of antibiotics at caution grade is too high.