Tissue engineering composites for bone defect treatment is currently a hot spot of the research field.Mechanical loading on tissue engineering composites is important to bone formation and related research has attracted more and more attention.In the field of tissue engineering research,the establishment of a standardized animal model is the basis of experimental research for exploring the effects of different mechanical loading on in situ repair of bone defect and its action mechanism.This paper reviews the approaches used to establish experimental model of bone defect under mechanical loading such as animal selection,defect preparation,fixation and loading mode in order to provide a reference for related research.

Objective To observe the changes of calcitonin gene-related peptide(CGRP) -immunoreactive positive nerve fibers innervation in bone tissue of femoral heads during the pathological process of early steroid-induced avascular necrosis of the femoral head (SANFH), and explore its significance.Methpathological group of SANFH was induced.Immunohistochemical technique was used and the changes of CGRP-immunoreactive positive nerve fibers innervation in weight bearing area of the femoral heads during the pathological process of early SANFH were observed.Result The number of CGRP-immunoreactive nerves increased first and then decreased ( Peaked at 6 weeks, 10.28 ± 0.66 ), but it was more than that ofnormal control group.There was significant difference between two groups ( P ＜ 0.01 ).Conclusion There were changes in the distribution of CGRP-immunoreactive positive nerves fiber during the process of bone repair after SANFH.CGRP-immunoreactive positive nerves fiber might take part in the process of bone repair in SANFH.

Objective:To primarily investigate the application value of glasses-free three-dimensional (3D) laparoscopy system in laparoscopic radical resection of gastrointestinal malignant tumors.Methods:The retrospective cohort study was conducted. The clinical data of 165 patients with gastrointestinal malignant tumors who were admitted to the Ruijin Hospital of Shanghai Jiaotong University School of Medicine between October 2018 and May 2019 were collected. There were 99 males and 66 females, aged from 28 to 86 years, with a median age of 63 years. There were 68 of 165 patients with gastric cancer and 97 with colorectal cancer. Sixteen patients with gastric cancer who underwent laparoscopic radical gastrectomy using the glasses-free 3D laparoscopy system were divided into glasses-free 3D gastric cancer group, and 52 patients with gastric cancer who underwent laparoscopic radical gastrectomy using the polarized glasses 3D laparoscopy system were divided into polarized glasses 3D gastric cancer group. Nineteen patients with colorectal cancer who underwent laparoscopic radical colectomy or proctectomy using the glasses-free 3D laparoscopy system were divided into glasses-free 3D colorectal cancer group, and 78 patients with colorectal cancer who underwent laparoscopic radical colectomy or proctectomy using the polarized glasses 3D laparoscopy system were divided into polarized glasses 3D colorectal cancer group. Observation indicators: (1) operative situations of patients with gastric cancer; (2) postoperative recovery of patients with gastric cancer; (3) postoperative pathological examination results of patients with gastric cancer; (4) operative situations of patients with colorectal cancer; (5) postoperative recovery of patients with colorectal cancer; (6) postoperative pathological examination results of patients with colorectal cancer; (7) follow-up. Follow-up was conducted by outpatient examination or telephone interview to detect complications and survival of patients up to the postoperative 30th day. Measurement data with skewed distribution were represented as M ( P25, P75) or M (range), and comparison between groups was analyzed by the Mann-Whitney U test. Count data were represented as absolute numbers or percentages, and comparison between groups was analyzed using the chi-square test or Fisher exact probability. Results:(1) Operative situations of patients with gastric cancer: all the 68 gastric cancer patients received successfully laparoscopic radical gastrectomy, without intraoperative complication or conversion to laparotomy. Cases with distal gastrectomy or total gastrectomy(surgical methods) , operation time, volume of intraoperative blood loss were 11, 5, 195 minutes(169 minutes, 214 minutes), 20 mL (10 mL, 90 mL) in patients of the glasses-free 3D gastric cancer group, and 31, 21, 196 minutes(173 minutes, 222 minutes), 40 mL(20 mL, 100 mL) in patients of the polarized glasses 3D gastric cancer group, with no significant difference between the two groups ( χ2=0.432, Z=-0.362, -1.065, P>0.05). (2) Postoperative recovery of patients with gastric cancer: the time to first flatus, time to initial semi-fluid diet intake, duration of postoperative hospital stay were 2 days(2 days, 3 days), 6 days(5 days, 7 days), 10 days(9 days, 14 days) in patients of the glasses-free 3D gastric cancer group, and 2 days(2 days, 3 days), 6 days(5 days, 6 days), 11 days(9 days, 14 days) in patients of the polarized glasses 3D gastric cancer group, with no significant difference between the two groups ( Z=-0.163, -1.870, -0.570, P>0.05). The postoperative complication incidence of the glasses-free 3D gastric cancer group was 12.5%(2/16), including 1 case with duodenal stump fistula, 1 case with anastomotic bleeding. The postoperative complication incidence of the polarized glasses 3D gastric cancer group was 17.3%(9/52), including 2 cases with duodenal stump fistula, 2 cases with delayed gastric emptying, 1 case with pulmonary infection, 1 case with abdominal bleeding, 1 case with anastomotic leakage, 1 case with chylous fistula, 1 case with intestinal obstruction. All the patients with complications were cured after symptomatic supportive treatment. There was no significant difference in the complication incidence between the two groups ( χ2=0.209, P>0.05). (3) Postoperative pathological examination results of patients with gastric cancer: the tumor diameter, cases in stage T1, T2, T3, T4 (tumor T staging), cases with vascular invasion, cases with nerve invasion, cases with tumor nodule, cases in stage N0, N1, N2, N3 (tumor N staging), the number of positive lymph node, the number of lymph node dissected, cases with qualified lymph node dissected, cases in stage Ⅰ, Ⅱ, Ⅲ, Ⅳ (TNM clinical staging) were 3.0 cm(2.0 cm, 5.0 cm), 5, 3, 1, 7, 8, 5, 2, 3, 2, 4, 7, 6(1, 15), 28(22, 43), 15, 4, 3, 9, 0 in patients of the glasses-free 3D gastric cancer group, and 3.5 cm(2.0 cm, 6.0 cm), 13, 10, 4, 25, 19, 23, 2, 26, 6, 7, 13, 1(0, 7), 29(21, 39), 43, 21, 10, 20, 1 in patients of the polarized glasses 3D gastric cancer group. There was no significant difference in the tumor diameter, tumor T staging, cases with vascular invasion, cases with nerve invasion, cases with tumor nodule, the number of lymph node dissected, cases with qualified lymph node dissected, TNM clinical staging between the two groups ( Z=-0.570, -0.434, χ2 =0.926, 0.851, 1.655, Z=-0.579, χ2=1.193, Z=-1.134, P>0.05). There were significant differences in the tumor N staging and the number of positive lymph node between the two groups ( Z=-2.167, -2.283, P<0.05). (4) Operative situations of patients with colorectal cancer: all the 97 colorectal cancer patients received successfully laparoscopic radical colectomy or proctectomy, without intraoperative complications or conversion to laparotomy. Cases with radical colectomy or proctectomy (surgical methods), operation time, volume of intraoperative blood loss were 7, 12, 132 minutes(97 minutes, 156 minutes), 20 mL(10 mL, 50 mL) in patients of the glasses-free 3D colorectal cancer group, and 40, 38, 124 minutes(110 minutes, 159 minutes), 25 mL(15 mL, 65 mL) in patients of the polarized glasses 3D colorectal cancer group, with no significant difference between the two groups ( χ2 =1.276, Z=-0.141, -0.863, P>0.05). (5) Postoperative recovery of patients with colorectal cancer: the time to first flatus, time to initial semi-fluid diet intake, duration of postoperative hospital stay were 2 days(1 days, 3 days), 5 days(5 days, 6 days), 8 days(7 days, 10 days) in patients of the glasses-free 3D colorectal cancer group, and 2 days(1 days, 3 days), 5 days(4 days, 6 days), 8 days(6 days, 10 days) in patients of the polarized glasses 3D colorectal cancer group, with no significant difference between the two groups ( Z=-0.678, -1.751, -1.674, P>0.05). The complication incidence of the glasses-free 3D colorectal cancer group was 15.8%(3/19), including 1 case with anastomotic leakage after low anterior proctectomy, 1 case with incision infection, 1 case with urinary tract infection. The complication incidence of the polarized glasses 3D colorectal cancer group was 14.1%(11/78), including 3 cases with anastomotic leakage after low anterior proctectomy, 2 cases with intestinal obstruction, 2 cases with urinary tract infection, 2 cases with incision infection, 1 case with anastomotic bleeding, 1 case with pulmonary infection. One of the 3 cases with anastomotic leakage after low anterior proctectomy in the polarized glasses 3D colorectal cancer group was cured after remedial terminal ileostomy. The other patients with complications were cured after symptomatic supportive treatment. There was no significant difference in the complication incidence between the two groups ( χ2=0.035, P>0.05). (6) Postoperative pathological examination results of patients with colorectal cancer: the tumor diameter, cases in stage T1, T2, T3, T4 (tumor T staging), cases with vascular invasion, cases with nerve invasion, cases with tumor nodule, cases in stage N0, N1-N2 (tumor N staging), the number of positive lymph node, the number of lymph node dissected, cases with qualified lymph node dissected, cases in stage Ⅰ, Ⅱ, Ⅲ, Ⅳ (TNM clinical staging) were 5.0 cm(3.0 cm, 6.0 cm), 3, 2, 7, 7, 3, 2, 1, 8, 11, 0(0, 4), 17(14, 23), 18, 2, 3, 12, 2 in patients of the glasses-free 3D colorectal cancer group, and 4.0 cm(3.0 cm, 5.0 cm), 7, 16, 43, 12, 14, 12, 7, 46, 32, 0(0, 1), 16(13, 19), 74, 14, 17, 40, 7 in patients of the polarized glasses 3D colorectal cancer group, with no significant difference between the two groups ( Z=-0.768, -1.135, χ2 =0.049, 0.292, 0.278, 1.762, Z=-0.694, -1.349, χ2=0.001, Z=-1.011, P>0.05). (7) Follow-up: 165 patients received follow-up, with out short-term reoperation or postoperative death in the postoperative 30 days. Conclusion:There is no significant difference in the efficacy between glasses-free 3D laparoscopic surgery and polarized glasses 3D laparoscopic surgery for radical resection of gastrointestinal malignant tumors, of which the clinical value requires further study.

ObjectiveTo investigate the influence of sarcopenia on bone mass loss， the risk factors for bone mass loss in liver cirrhosis， and the correlation between body composition and bone mineral density （BMD） by comparing the clinical features of bone mass loss in patients with liver cirrhosis. MethodsA total of 92 patients who were hospitalized and diagnosed with liver cirrhosis in Department of Gastroenterology， The Second Affiliated Hospital of Kunming Medical University， from April to December of 2022 were enrolled， and based on the results of dual-energy X-ray absorptiometry， they were divided into bone mass loss group （osteopenia/osteoporosis） with 57 patients and normal bone mass group with 35 patients. The two groups were compared in terms of general data， laboratory examination， imaging data， and body composition analysis. The independent samples t-test or the Mann-Whitney U test was used for comparison of continuous data between two groups， and the chi-square test or the continuity correction chi-square test was used for comparison of categorical data between two groups； Pearson correlation analysis and Spearman correlation analysis were used to investigate correlation； a binary logistic regression analysis was used to investigate the risk factors for bone mass loss in liver cirrhosis. ResultsCompared with the normal bone mass group， the bone mass loss group had significantly higher age （t=-3.597， P<0.05）， proportion of female patients （χ²=8.393， P<0.05）， N-terminal middle molecular fragment of osteocalcin （N-MID） （Z=-3.068， P<0.05）， β isomer of C-terminal telopeptide of type I collagen （β-CTX） （t=-2.784， P<0.05）， and proportion of patients with sarcopenia （χ²=13.884， P<0.05） and significantly lower calcitonin （CT） （Z=-2.340， P<0.05） and L3 skeletal muscle index （L3-SMI） （t=4.621， P<0.05）. Compared with the normal bone mass group， the bone mass loss group had significantly lower total muscle mass （Z=-2.952， P<0.05）， right upper limb muscle mass （Z=-2.929， P<0.05）， left upper limb muscle mass （Z=-2.680， P<0.05）， right lower limb muscle mass （Z=-3.366， P<0.05）， left lower limb muscle mass （Z=-3.374， P<0.05）， presumed bone mass （t=2.842， P<0.05）， body water mass （Z=-2.779， P<0.05）， basal metabolic rate （BMR） （Z=-3.153， P<0.05）， and BMD of L1— L4 and femoral neck （t=9.789， t=10.280， t=10.832， Z=-7.298， t=8.945， all P<0.05）. Total muscle mass， muscle mass of trunk and limbs， presumed bone mass， BMR， and body water mass in body component analysis were positively correlated with L1 — L4 BMD and femoral neck BMD （all P<0.05）， and fat mass was positively correlated with L1 — L4 BMD （all P<0.05）. Sarcopenia （odds ratio ［OR］=8.737， 95% confidence interval ［CI］： 2.237 — 34.129， P=0.002）， age （OR=1.094， 95%CI： 1.019 — 1.175， P=0.013）， and N-MID （OR=1.095， 95%CI： 1.019 — 1.176， P=0.014） were independent risk factors for bone mass loss in patients with liver cirrhosis. ConclusionOld age， female sex， sarcopenia， elevated N-MID， elevated β-CTX， reduction in CT， low muscle mass， low presumed bone mass， low BMR， and low body water mass are the features of bone mass loss in patients with liver cirrhosis， and sarcopenia， age， and N-MID are independent risk factors for bone mass loss in patients with liver cirrhosis. Detailed assessment of body composition changes can help to identify abnormal BMD in patients with liver cirrhosis.

OBJECTIVE To explore the effect mechanism of ethanol extract from Atractylodes macrocephala （EEAM） on microglial phagocytosis and degradation of amyloid β （Aβ） based on peroxisome proliferator-activated receptor γ （PPAR- γ） signaling pathway. METHODS Taking neuromicroglial cell BV2 as subjects， confocal microscopy was used to observe the effects of EEAM （0.3， 0.4， 0.5 mg/mL， similarly hereinafter） on phagocytosis and degradation of Aβ in microglia. Human embryonic kidney cell HEK293 was used to investigate the effects of EEAM on luciferase transcriptional activity of PPAR-γ. The effect of EEAM on nuclear translocation of PPAR-γ was investigated by immunofluorescence. Alzheimer’s disease BV2 cell model was induced by Aβ1-42， and quantitative polymerase chain reaction was used to investigate the effects of EEAM on mRNA expressions of PPAR-γ downstream target genes （Lxra， Lxrb， Abca1， Abcg1， Cd36， Sra and Apoe）. RESULTS The results of Aβ uptake experiment showed that after the intervention of medium and high doses of EEAM， fluorescence intensity of Aβ in BV2 cells increased significantly （P＜0.05）. The degradation experiment of Aβ showed that after the intervention of medium and high doses of EEAM， fluorescence intensity of Aβ in BV2 cells decreased significantly （P＜0.05）. After the intervention of different doses of EEAM， luciferase transcriptional activity of PPAR-γ in HEK293 cells increased significantly （P＜0.05）； fluorescence intensity of PPAR-γ in BV2 cells and nuclei （except for low-dose group） increased significantly （P＜0.05）. mRNA expressions of Lxra， Lxrb， Abca1， Abcg1， Cd36， Sra and Apoe in BV2 cells were increased significantly （P＜0.05）. CONCLUSIONS EEAM can promote the uptake and degradation of Aβ in microglia by activating PPAR-γ signaling pathway， thus improving Alzheimer’s disease.

The correct differentiation of oligodendrocyte precursor cells (OPCs) is essential for the myelination and remyelination processes in the central nervous system. Determining the regulatory mechanism is fundamental to the treatment of demyelinating diseases. By analyzing the RNA sequencing data of different neural cells, we found that cyclin-dependent kinase 18 (CDK18) is exclusively expressed in oligodendrocytes. In vivo studies showed that the expression level of CDK18 gradually increased along with myelin formation during development and in the remyelination phase in a lysophosphatidylcholine-induced demyelination model, and was distinctively highly expressed in oligodendrocytes. In vitro overexpression and interference experiments revealed that CDK18 directly promotes the differentiation of OPCs, without affecting their proliferation or apoptosis. Mechanistically, CDK18 activated the RAS/mitogen-activated protein kinase kinase 1/extracellular signal-regulated kinase pathway, thus promoting OPC differentiation. The results of the present study suggest that CDK18 is a promising cell-type specific target to treat demyelinating disease.