BACKGROUND:Macrophage migration inhibitory factor(MIF)is a pleiotropic cytokine,which is secreted in different types of stem cells and can regulate the proliferation,differentiation and migration of various types of stem cells.Our previous research has confirmed that human embryonic stem cells secrete MIF and that its concentration in the culture medium is relatively stable.However,whether MIF is involved in the survival,proliferation and differentiation of human embryonic stem cells remains unclear. OBJECTIVE:To investigate the effects of MIF on survival,proliferation,and differentiation of human embryonic stem cells. METHODS:(1)Human embryonic stem cells H9 were cultured.The growth curve of cells was detected and plotted by CCK-8 assay.Enzyme-linked immunosorbent assay was used to determine the level of MIF in the medium.(2)To determine the effects of exogenous MIF on the survival and proliferation of human embryonic stem cells,different groups were established:the control group,which was cultured in stem cell medium without any modifications;the exogenous MIF group,which was treated with different concentrations(30,100,300 ng/mL)of MIF in the stem cell medium;the MIF inhibitor ISO-1 group,which was treated with different concentrations(2,7,21 μmol/L)of ISO-1 in the stem cell medium;and the MIF+ISO-1 group,which was treated with different concentrations of ISO-1 along with 100 ng/mL of MIF.Cell viability was assessed using the CCK-8 assay.(3)To further elucidate the effect of MIF gene on survival and proliferation of human embryonic stem cell,the MIF knockout H9 cell line was constructed by CRISPR-Cas 9 technology to observe the lineage establishment.(4)To determine the effect of high concentrations of MIF on human embryonic stem cell differentiation,100 ng/mL MIF and 100 ng/mL of CXCR4 neutralizing antibody were separately added to the normal stem cell culture medium.The expression levels of self-renewal factors(KLF4,c-MYC,NANOG,OCT4,and SOX2)and differentiation transcription factors(FOXA2,OTX2)were measured using real-time quantitative polymerase chain reaction,immunofluorescence staining,and western blot analysis. RESULTS AND CONCLUSION:(1)The logarithmic growth phase of H9 cells was between 3-6 days.Under normal growth conditions,human embryonic stem cells secreted MIF at a concentration of approximately 20 ng/mL,independent of cell quantity.(2)Compared to the control group,the addition of different concentrations of MIF had no effect on the proliferation of human embryonic stem cells(P>0.05).ISO-1 significantly inhibited the proliferation of human embryonic stem cells,with a stronger inhibition observed at higher concentrations of ISO-1(P<0.05).The addition of MIF in the presence of ISO-1 reduced the inhibitory effect of ISO-1(P<0.05).(3)Real-time quantitative polymerase chain reaction showed that knocking out 50%of the MIF gene resulted in a significant decrease in the growth vitality of human embryonic stem cells and failure to establish cell lines.(4)Adding 100 ng/mL exogenous MIF to the culture medium resulted in a decrease in the mRNA,protein,and fluorescence expression levels of the self-renewal transcription factor KLF4,while the mRNA,protein,and fluorescence expression levels of the differentiation factor FOXA2 increased.(5)When 100 ng/mL CXCR4 neutralizing antibody was added to the culture medium,the mRNA and protein expression levels of KLF4 increased,while the mRNA and protein expression levels of FOXA2 decreased,contrary to the expression trend observed in the MIF group.In conclusion,the endogenous secretion of MIF by human embryonic stem cells is essential for their survival.The addition of MIF to the culture medium does not promote the proliferation of human embryonic stem cells.However,it can lead to a decrease in the expression of the self-renewal factor KLF4 and an increase in the expression of the transcription factor FOXA2.This provides a clue for further investigation into the effects and mechanisms of MIF on the differentiation of human embryonic stem cells.The MIF-CXCR4 axis plays a regulatory role in this process.

Objective To investigate the association between four single nucleotide polymorphisms(SNP)(rs9340 in MAPK1,rs14804 in NRAS,rs712 and rs7973450 in KRAS)in the 3'UTR of ERK1/2 signaling pathway-related genes and non-small cell lung cancer(NSCLC).Methods A total of 478 NSCLC patients and 480 healthy controls were enrolled in this study.Four SNPs were genotyped by using TaqMan assays.The association between the four SNPs and NSCLC was analyzed.Results The distribution frequency difference of the allele of rs9340 was statistically significant between the control group and the non-small cell squamous cell carcinoma(SCC)group(P = 0.009),suggesting that the G allele of rs9340 may be a protective factor for non-small cell lung squamous cell carcinoma(OR = 0.67,95%CI:0.50～0.91).In addition,in the<50 years age group,the distribution frequency difference of the allele of rs9340 was statistically significant between the control group and the NSCLC group(P = 5.07×10-4),indicating that the G allele of rs9340 may be a protective factor for NSCLC(OR = 0.46,95%CI:0.29～0.72).Conclusion The SNP rs9340 in MAPK1 may be associated with the risk of NSCLC.

Objective:To explore effect of polydatin on ocular surface dysfunction and pathology in dry eye disease(DED)rats and its protective mechanism.Methods:Eighteen from 90 SD rats were randomly chosen as control group,and other rats were injected subcutaneously with scopolamine hydrobromide to establish DED model.After modeling,rats were separated into model group,0.05%polydatin group,0.5%polydatin group,0.5%polydatin+U0126[mitogen-activated protein kinase kinase(MEK)inhibi-tor]group,with 18 rats in each group;each administration group was given corresponding doses of drugs for intervention,and rats in control group and model group were given same amount of normal saline.On the 7th,14th,21st,and 28th day of intervention,Schirmer test was performed to measure tear secretion amount of rats in each group,fluorescein staining was performed to measure tear film breakup time(BUT)and corneal damage of rats in each group;RT-qPCR was performed to measure mRNA expression of pro-inflammatory factors TNF-α,IFN-γ and IL-1β in cornea and conjunctival tissues;HE staining was performed to observe histopatho-logical changes of cornea;PAS staining was performed to evaluate number of conjunctival goblet cells;Western blot was performed to detect expressions of MEK/extracellular regulatory protein kinase(ERK)pathway related proteins.Results:Compared with control group,tear secretion amount BUT and number of conjunctival goblet cells in model group were obviously reduced(P<0.05),corneal injury score,TNF-α,IFN-γ and IL-1β mRNA levels were obviously increased(P<0.05),corneal epithelial layer was thinned,a large number of inflammatory cell infiltration and new capillaries could be seen;compared with model group,tear secretion amount,BUT,number of conjunctival goblet cells,p-MEK1/2/MEK1/2 and p-ERK1/2/ERK1/2 in 0.05%polydatin group and 0.5%polydatin group were obviously increased(P<0.05),corneal injury score,TNF-α,IFN-γ and IL-1β mRNA levels were obviously reduced(P<0.05),pathological damage of corneal tissue was obviously relieved;U0126 could significantly attenuate protective effects of polydatin on ocular surface dysfunction and pathological changes in DED rats.Conclusion:Polydatin may improve ocular surface dysfunction and pathology of DED rats induced by scopolamine by activating MEK/ERK pathway.

OBJECTIVE: To investigate the effects of melatonin (MT) on bone mass and serum inflammatory factors in rats received ovariectomy (OVX) and to investigate the effects of MT on the levels of inflammatory factors in culture medium and osteogenic ability of bone marrow mesenchymal stem cells (BMSCs) stimulated by lipopolysaccharide. METHODS: Fifteen 12-week-old Sprague Dawley (SD) rats were randomly divided into 3 groups. The rats in Sham group only received bilateral lateral abdominal incision and suture, the rats in OVX group received bilateral OVX, and the rats in OVX+MT group received 100 mg/(kg·d) MT oral intervention after bilateral OVX. After 8 weeks, the levels of serum inflammatory factors [interleukin-1β (IL-1β), IL-6, and tumor necrosis factor α (TNF-α)] were detected using ELISA assay. Besides, the distal femurs were detected by Micro-CT to observe changes in bone mass and microstructure, and quantitatively measured bone volume fraction, trabecular thickness, and trabecular number. The BMSCs were extracted from the femurs of three 3-week-old SD rats using whole bone marrow culture method and passaged. The 3rd-5th passage BMSCs were cultured with different concentrations of MT (0, 1, 10, 100, 1 000 µmol/L), and the cell viability was then detected using cell counting kit 8 (CCK-8) to select the optimal concentration of MT for subsequent experiments. Cells were devided into osteogenic induction group (group A) and osteogenic induction+1/5/10 μg/mL lipopolysaccharide group (group B-D). The levels of inflammatory factors (IL-1β, IL-6 and TNF-α) in cell culture medium were detected using ELISA assay after corresponding intervention. According to the results of CCK-8 method and ELISA detection, the cells were intervened with the most significant concentration of lipopolysaccharide for stimulating inflammation and the optimal concentration of MT with osteogenic induction, defining as group E, and the cell culture medium was collected to detect the levels of inflammatory factors by ELISA assay. After that, alkaline phosphatase (ALP) staining and alizarin red staining were performed respectively in groups A, D, and E, and the expression levels of osteogenic related genes [collagen type Ⅰ alpha 1 chain (Col1a1) and RUNX family transcription factor 2 (Runx2)] were also detected by real time fluorescence quantitative PCR (RT-qPCR). RESULTS: ELISA and Micro-CT assays showed that compared with Sham group, the bone mass of the rats in the OVX group significantly decreased, and the expression levels of serum inflammatory factors (IL-1β, IL-6, and TNF-α) in OVX group significantly increased (P<0.05). Significantly, the above indicators in OVX+MT group were all improved (P<0.05). Rat BMSCs were successfully extracted, and CCK-8 assay showed that 100 µmol/L was the maximum concentration of MT that did not cause a decrease in cell viability, and it was used in subsequent experiments. ELISA assays showed that compared with group A, the expression levels of inflammatory factors (IL-1β, IL-6, and TNF-α) in the cell culture medium of groups B-D were significantly increased after lipopolysaccharide stimulation (P<0.05), and in a concentration-dependent manner. Moreover, the expression levels of inflammatory factors in group D were significantly higher than those in groups B and C (P<0.05). After MT intervention, the expression levels of inflammatory factors in group E were significantly lower than those in group D (P<0.05). ALP staining, alizarin red staining, and RT-qPCR assays showed that compared with group A, the percentage of positive area of ALP and alizarin red and the relative mRNA expressions of Col1a1 and Runx2 in group D significantly decreased, while the above indicators in group E significantly improved after MT intervention (P<0.05). CONCLUSION MT may affect the bone mass of postmenopausal osteoporosis by reducing inflammation in rats; MT can reduce the inflammation of BMSCs stimulated by lipopolysaccharide and weaken its inhibition of osteogenic differentiation of BMSCs.
Female ; Rats ; Animals ; Tumor Necrosis Factor-alpha ; Osteogenesis ; Rats, Sprague-Dawley ; Core Binding Factor Alpha 1 Subunit ; Melatonin/pharmacology* ; Interleukin-6/genetics* ; Lipopolysaccharides/pharmacology* ; Coloring Agents ; Inflammation

Objective:To investigate the expression of programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) pathway in patients with acute myeloid leukemia (AML) and its relationship with clinical features and prognosis, and to examine its effect on PD-1-positive natural killer (NK) cells against AML cells in vitro.Methods:The bone marrow samples of 65 AML patients and the peripheral blood of 32 AML patients diagnosed in Affiliated Cancer Hospital of Zhengzhou University from July 2019 to December 2020 were prospectively collected, and the peripheral blood of 24 healthy people was taken as healthy control. The expression level of PD-L1 in bone marrow tumor cells and expression level of PD-1 in peripheral blood NK cells were detected by flow cytometry. The correlations of PD-1 expression in bone marrow tumor cells and PD-1 expression in NK cells with the clinicopathological features, curative effect and prognosis of patients were analyzed. Flow cytometry was used to detect the expression level of PD-L1 in AML cell line THP-1 (target cells) and the expression level of PD-L1 in NK cell line NKL (effector cells). THP-1 cells treated with and without 25 μmol/L of PD-L1 inhibitor fraxinellone were used as experimental group and control group, and co-cultured with NKL cells at different effector-to-target ratios. The apoptosis of THP-1 cells and the expression of NKG2D in NKL cells were detected by flow cytometry, the cell proliferation status was detected by CCK-8 and the cell proliferation inhibition rate was calculated; the levels of interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) in the supernatant of co-culture system were detected by enzyme-linked immunosorbent assay (ELISA).Results:The proportion of AML patients with PD-L1-positive expression in bone marrow tumor cells was higher than that in the healthy control group [38.5% (25/65) vs. 8.3% (2/24), P = 0.029]. The proportion of AML patients with PD-1-positive expression in peripheral blood NK cells was higher than that in the healthy control group [40.6% (13/32) vs. 12.5% (3/24), P = 0.035]. There were no statistical differences in sex, age, hemogram, proportion of primordial cells, risk stratification, chromosomal karyotype, gene mutation (except NPM1 gene), fusion gene and French-American-British cooperative group (FAB) typing between patients with PD-L1 positive and negative in bone marrow tumor cells and between patients with PD-1 positive and negative in peripheral blood NK cells (all P > 0.05). In relapsed/refractory patients, the proportion of patients with PD-L1-positive expression in bone marrow tumor cells was higher than that in newly treated patients [58.8% (10/17) vs. 31.2% (15/48), P = 0.045]. There was no significant difference in the proportion of patients with PD-1-positive expression in peripheral blood NK cells between relapsed/refractory patients and newly treated patients [(38.5% (5/13) vs. 42.1% (8/19), P = 0.837]. There was no statistical difference in complete remission (CR) rate between PD-L1 positive and negative patients [69.6% (16/23) vs. 74.3% (26/35), P > 0.05]. There was no statistical difference in CR rate between PD-1 positive and negative patients [66.7% (8/12) vs. 70.6% (12/17), P > 0.05]. There was no statistical difference in recurrence rate after CR between PD-L1 positive and negative patients [12.5% (2/16) vs. 19.2% (5/26), P > 0.05]. There was no statistical difference in recurrence rate after CR between PD-1 positive and negative patients [25.0% (2/8) vs. 16.7% (2/12), P > 0.05]. Flow cytometry showed that the positive rate of PD-1 in NKL cells was (67±6)% and the positive rate of PD-L1 in THP-1 cells was (85±5)%. After co-culture with NKL cells, the apoptotic rate and proliferation inhibition rate of THP-1 cells were higher in the experimental group compared with the control group, the expression of NKG2D on the surface of NKL cells was elevated, and the levels of IFN-γ and TNF-α in the co-culture supernatant were increased. Conclusions:In AML patients, the expression of PD-L1 in bone marrow tumor cells is high, and the expression of PD-1 in peripheral blood NK cells is also high. The expression of PD-L1 in bone marrow tumor cells of relapsed/refractory AML patients is higher than that of newly treated patients. Inhibition of PD-L1 expression in THP-1 cells can enhance the tumor killing activity of NKL cells in vitro. The mechanism may be that inhibition of PD-L1 expression in THP-1 cells up-regulates the expression of NKL cell activated receptor NKG2D and promotes the secretion of IFN- γ and TNF- α.

Chronic refractory wound (CRW) is one of the most challengeable issues in clinic due to complex pathogenesis, long course of disease and poor prognosis. Experts need to conduct systematic summary for the diagnosis and treatment of CRW due to complex pathogenesis and poor prognosis, and standard guidelines for the diagnosis and treatment of CRW should be created. The Guideline forthe diagnosis and treatment of chronic refractory wounds in orthopedic trauma patients ( version 2023) was created by the expert group organized by the Chinese Association of Orthopedic Surgeons, Chinese Orthopedic Association, Chinese Society of Traumatology, and Trauma Orthopedics and Multiple Traumatology Group of Emergency Resuscitation Committee of Chinese Medical Doctor Association after the clinical problems were chosen based on demand-driven principles and principles of evidence-based medicine. The guideline systematically elaborated CRW from aspects of the epidemiology, diagnosis, treatment, postoperative management, complication prevention and comorbidity management, and rehabilitation and health education, and 9 recommendations were finally proposed to provide a reliable clinical reference for the diagnosis and treatment of CRW.

Objective The purpose of this study was to investigate the protective effect of dexmedetomidine(DEX)on pathological car-diomyocyte hypertrophy.Methods An in vitro cell population was established in neonatal rats.The rats were divided into six groups:control group(C)without serum for 24 h,model group(A)with angiotensin Ⅱ(Ang Ⅱ)for 24 h,dexmedetomidine group(AD)with Ang Ⅱ+DEX(5μmol/L)for 24 h,C'group with serum-free culture for 48 h,A'group with Ang Ⅱfor 24 h,and AD'group with DEX+Ang Ⅱfor 24 h.The morphological changes of cells were observed by immunofluorescence.The protein expressions of atrial natriuretic peptide(ANP),brain natriuretic peptide(BNP),and myosin heavy chain(β-MHC)were detected by western blot,and the cell activity was detected by CCK-8.Results Compared with group C,the size of cells in group A was larger,and that in group AD was even more significant.Simi-lar observations were found for hypertrophy related proteins.Compared with group C,the expression of ANP,BNP,and βMHC increased in group A,although the increase in AD group was more obvious.CCK-8 detection showed that compared with group C,the activity of group A decreased and that of group AD increased significantly.Compared with the C'group,the expression of hypertrophy-related pro-tein in the A'group was significantly increased,but the expression of ANP and BNP protein in the AD'group was significantly lower than that in the A'group.The differences were statistically significant(P<0.05).Conclusion Dexmedetomidine can alleviate the occur-rence of pathological hypertrophy through compensatory mechanisms similar to physiological myocardial hypertrophy,and may play a role in myocardial protection.

Objective:To investigate the characteristics of blood glucose fluctuation and risk factors in type 2 diabetic patients with asymptomatic hypoglycemia.Methods:From September 2018 to July 2021, 342 patients with type 2 diabete mellitus who were hospitalized in the Department of Endocrinology of Hefei Hospital Affilitated to Anhui Medical University were enrolled for a retrospective study. The mean amplitude of glycemic excursions(MAGE), coefficient of variation (CV), 24 hour mean blood glucose level (MG), and time in range (TIR) were obtained by continuous glucose monitoring (CGM). According to the results of CGM and whether the patients have hypoglycemia symptoms, they were divided into three groups: no hypoglycemia group, symptomatic hypoglycemia group, and asymptomatic hypoglycemia group. The differences in blood glucose fluctuations were compared among the three groups. Multivariate logistic regression analysis was used to evaluate the risk factors in type 2 diabete mellitus patients with asymptomatic hypoglycemia. The predictive value of MAGE for asymptomatic hypoglycemia was analyzed by receiver operating characteristic (ROC) curve.Results:Compared with the non-hypoglycemia group, the TIR in asymptomatic hypoglycemia group was higher ( Z=-2.042, P=0.041). The asymptomatic hypoglycemia group had lower MG, higher MAGE and CV compared with the other two groups(all P<0.05). Multivariate logistic regression analysis showed that urinary albumin/creatinine ratio (UACR), MAGE, and CV were the risk factors for asymptomatic hypoglycemia, while MG was the protective factor. After adjustment for other risk factors, MAGE was still associated with asymptomatic hypoglycemia ( OR=1.111, 95% CI 0.999-1.235, P=0.049). The sensitivity and specificity of MAGE in predicting asymptomatic hypoglycemia were 0.769 and 0.776, respectively. Conclusions:Patients with asymptomatic hypoglycemia present with larger TIR and MAGE. MAGE, UACR, and CV were risk factors for asymptomatic hypoglycemia. Moreover, MAGE has some predictive value for the occurrence of asymptomatic hypoglycemia.

Objective:To investigate the mid-term clinical outcomes of selective column arthrodesis based on the three-column theory in the treatment of malunion of Lisfranc injury.Methods:The 28 patients with malunion of Lisfranc injury were analyzed retrospectively who had been treated by selective column arthrodesis at Department of Orthopedic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine from January 2011 to January 2020.They were 18 males and 10 females, with an average age of 37.2 years(from 18 to 65 years). Twelve left and 16 right sides were affected. According to Myerson's three-column classification, one case was medial column injury (type A), 4 ones middle column injury (type B), 7 ones medial plus middle columns injury and 16 ones three-column injury. Medial column arthrodesis was conducted in 7, middle column arthrodesis in 4 and medial plus middle columns arthrodesis in 17. The American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score and visual analogue scale (VAS) were compared between preoperation and the last follow-up to evaluate the improvements in foot function and pain. The operation-related complications were recorded.Results:All patients were followed up for an average of 35.6 months (from 18 to 60 months). The AOFAS midfoot score increased from 43.1±4.1 at pre-operation to 84.1± 7.4 at the last follow-up and the VAS score decreased from 5.7±1.3 at pre-operation to 2.0±0.9 at the last follow-up (both P<0.001). The wounds healed in 28 patients, 3 of whom had postoperative wound exudation but responded to dressing change. There were no such complications as injury to the deep peroneal nerve or deep venous thrombosis. The internal fixation was removed in 5 patients at about one year after arthrodesis. Conclusion:Selective column arthrodesis based on the three-column theory can result in satisfactory med-term clinical outcomes in the treatment of malunion of Lisfranc injury.

Objective:To explore any effect of training assisted by a pelvic rehabilitation robot on trunk control and walking after cerebral infarction.Methods:Forty cerebral infarction survivors with hemiplegia were randomly divided into an experimental group and a control group, each of 20. Both groups were given routine neurological medication and rehabilitation training, while the experimental group was additionally provided with 20 minutes of robot-assisted gait training daily, five times a week, for 4 weeks. Before and after the intervention, the motor function, walking function, trunk control and pelvic movement were assessed using a simplified version of the Fugl-Meyer assessment (FMA-LL), functional ambulation categories (FAC) and the trunk control test (TCT).Results:After the treatment, significant improvement was observed in all of the above measurements in both groups. The average FMA-LL, FAC and TCT results of the experimental group as well as their average pelvic lateral displacement, height displacement, rotation angle and roll angle were all significantly superior to the control group′s averages.Conclusions:Robot-assisted training can effectively improve lower limb motor functioning, trunk control, walking and pelvic motion after cerebral infarction, with better curative effect than routine rehabilitation training alone.