BACKGROUND: Bioabsorbable materials have shown obvious advantages in clinical application for more than ten years, and have been widely used in many biomedical fields. OBJECTIVE: To review characteristics of bioabsorbable materials and their application in orthopedics. METHODS: The articles published in Wanfang, CNKI, VIP, and PubMed databases were searched by computer. The key words were “bioabsorbable materials, bioabsorbable metal materials, bioabsorbable inorganic materials, polymer materials, biocomposites” in Chinese, and “bioabsorbable/bioabsorbable material, metal material, polymer material, biocomposites” in English. RESULTS AND CONCLUSION: Absorbable metal materials have good mechanical properties. The corrosion mechanism of polymer materials is clear, which can predict the corrosion behavior and corrosion rate in vivo and in vitro, but its load-bearing performance is not as good as that of absorbable metal materials. After certain treatment, bioceramics have good biocompatibility, bone conductivity and osseointegration, but they are brittle and difficult to be formed. Biocomposites have the properties of component materials, and can also obtain new properties that single component materials do not have, so it has a wide application prospect.

OBJECTIVE: At present, many studies have proved that intramedullary nail and steel plate internal fixation is a better way to treat displaced midshaft clavicular fracture. However, there are relatively few comparative studies on the advantages and disadvantages of the two methods, and there are still many controversies. Through the meta-analysis of related literature, the efficacy and safety of intramedullary nail and steel plate in the treatment of adult displaced midshaft clavicular fracture were systematically evaluated. METHODS: Through computer retrieval of PubMed, Embase, Cochrane Library, CNKI, Wanfang and VIP databases from the inception to January 2020, the literature of randomized controlled trials meeting the inclusion and exclusion criteria of intramedullary nail and steel plate in the treatment of adult displaced midshaft clavicular fracture was collected and screened, and the quality evaluation and data extraction were carried out. The operation time, incision length and upper limb function score, Constant-Murley score, and fracture healing time were used as the evaluation indexes of meta-analysis. Meta-analysis was performed using ReMan 5.3 software. RESULTS: (1) Eight valuable articles were retrieved, among which 283 patients were treated with intramedullary nail and 271 patients were treated with steel plate internal fixation. (2) The meta-analysis results showed that the intramedullary nail group was superior to the steel plate group in terms of operation time [MD=-19.63, 95%CI(-22.72,-16.54)], incision length [MD=-3.31, 95%CI(-5.78,-0.85)], and fracture healing time [MD=-1.53, 95%CI(-2.73,-0.33)]. (3) No significant difference was found in upper limb function score [MD=-1.91, 95%CI(-5.48, 1.66)] and Constant-Murley score [MD=-0.58, 95%CI(-4.63, 3.47) between the intramedullary nail group and the steel plate group after surgery. CONCLUSION: The results of meta-analysis showed that intramedullary nail was superior to steel plate in the operation time, incision length and fracture healing time in the treatment of displaced midshaft clavicular fracture. The above results can provide evidence for clinical use of intramedullary nail instead of steel plate internal fixation in the treatment of displaced midshaft clavicular fracture.

A novel method based on the separation and enrichment effect of magnetic beads and the fully complementary hybridization of two DNA strands was developed for highly sensitive detection of bacterial DNA using a surface-enhanced Raman spectroscopy (SERS) with 5,5’-dithio-bis(2-nitrobenzoic acid) (DTNB)-modified gold nanoparticles as reporter probes. Capture probe was immobilized onto the surface of streptavidin-enwrapped magnetic beads ( SA-MB ) through high affinity between biotin and avidin, by which the target bacterial DNA sequences that connected with the reported probe decorated AuNPs with DTNB and SH-DNA ( AuNPs@DTNB@DNA) were captured and loaded onto the magnetic beads by the hybridization reaction with the capture probe. Compared with previous methods, this design shortened the distance between particles by the ways that the magnetic beads tempted to nanoparticles aggregation, and produced the plasma resonance coupling effect, which increased the SERS signal significantly. The results showed that, under the optimized conditions and in the concentration range from 5 pmol/L to 5 nmol/L, the method performed a good linear relationship between Raman intensity and DNA concentration. The limit of detection ( LOD) of bacterial DNA was estimated to be 5 pmol/L. The method is simple and low cost, and can be used in the sensitive and selective detection of bacterial DNA.

Objective To assess the diagnostic value of MR imaging in follow-up evaluation of patients with hepatocellular carcinomas ( HCC ) treated with radiofrequency ablation ( RFA ) and to compare it with that of multi-slice CT.Methods From December 2009 to September 2011,there were 48 patients (56 HCCs) treated with RFA after transcatheter arterial chemoembolization (TACE). MR imaging and multi-slice CT were performed for follow-up.Two radiologists independently reviewed these images,detection of residual or recurrent tumor were assessed on a five-point scale and compared with Kappa test and with the method of receiver operating characteristic (ROC) curve analysis.Sensitivity,specificity and accuracy were evaluated.Results The observer agreement rate for MR imaging was higher ( 0.925 ) than for multi-slice CT (0.701,P ＜ 0.05).The area under the ROC curve (AUC)of MR imaging( 0.987 and 0.971 by two radiologists respectively) was significantly higher than that of CT( 0.674 and 0.598 by two radiologists respectively),P ＜0.05. The sensitivity, specificity and accuracy of detection rate for MRI [100％(22/22),95.5％ (86/90) and 95.5％ ( 107/112),respectively] were significantly different with that for multi-slice CT [40.9％ ( 9/22 ),57.8％ ( 52/90 ) and 60.7％ ( 68/112 ),respectively]. Conclusion Diagnostic accuracy and detection rate of residual or recurrent tumor were found to be superior with MR imaging than with multi-slice CT.

Objective To investigate the application valve of real-time fluorescence quantitative polymerase chain reaction(RT-PCR) for the detection of tumor M2-pyruvate kinase(tM2-PK) DNA in patients with colorectal cancer(CRC).Methods Fragment of tM2-PK DNA(162 bp) was amplified and inserted into PGM-T vector to construct recombinant plasmid,which was used to develop RT-PCR method.Sensitivity,specificity and repeatability of RT-PCR for the detection of tM2-PK were analyzed.From Jan.2014 to Jun.2016,200 CRC patients and 100 healthy subjects were enrolled and detected for fecal and serum tM2-PK DNA by using RT-PCR,and the detected results were compared with those detected by using enzyme linked immunosorbent assay(ELISA).Results Recombinant plasmid was successfully constructed,which was certified by sequencing.The sensitivity of RT-PCR for the detection of tM2-PK DNA was 10 copy/mL,with high specificity and 0.3%-2.9% of coefficient of variation.In patients,the positive rate of fecal tM2-PK DNA,detected by RT-PCR,was 92.50%,and that of ELISA to detect tM2-PK was 80.00%.Fecal and serum levels of tM2-PK were correlated with the pathologic stages of tumour.Conclusion Self-established RT-PCR could be specificity and sensitivity for the detection of fecal tM2-PK,which could be used for the early diagnosis of CRC.

To investigate the potential risk factors for hepatocellular carcinoma in primary biliary cholangitis (PBC) patients. Methods:The data of 670 PBC inpatients between January 2011 and December 2016 were collected from the database of The First Affiliated Hospital of Zhengzhou University. The potential risk factors were evaluated, and odds ratios (ORs) and 95% confidence intervals (CIs) were analyzed by univariate (unadjusted OR) and multivariate [adjusted OR (AOR)] conditional Logistic regression. Results: In total, 35 PBC patients developed liver carcinoma (5.2%); of these, 4 patients (female) were excluded because of incomplete data for influencing factors and 6 (2 male; 4 female) were excluded as they were diagnosed with hepatocellular carcinoma (HCC) during or before PBC. Therefore, 25 patients were included in the case-control study. Male patients were more likely than female patients to show alcohol in-take, smoking, a family history of malignancy, and serious liver injury (all P<0.05), indicated by the increasing levels of alanine amino-transferase (ALT), aspartate aminotransferase (AST), and gamma glutamyl transferase (GGT) (P<0.05). Conditional Logistic regression analysis revealed that body mass index (BMI) ≥25 kg/m2 (AOR=1.015, 95% CI: 1.001-1.257, P=0.032) and history of alcohol intake (AOR=10.014, 95% CI: 1.009-91.071, P=0.039) were significantly associated with increased odds of HCC development in PBC patients. Conclusions:The risk factors for PBC-associated liver carcinoma include BMI≥25 kg/m2 and history of alcohol intake. In addition to regular monitoring, PBC patients may benefit from alcohol abstinence and body weight control.

Objective To investigate the role and mechanism of circular RNA-vimentin (circ-VIM) in the proliferation and apoptosis of colorectal cancer cells.Methods From December 2016 to December 2017, at Department of General Surgery of The First Affiliated Hospital of Zhengzhou University, the clinical data of 100 patients who underwent radical resection of colorectal cancer and were confirmed by pathological examination after operation were collected.The tumor tissues and corresponding paracancerous tissues (negative control) were also collected.The expression of circ-VIM in the colorectal cancer tissues was determined by quantitative real-time polymerase chain reaction (qRT-PCR).The proliferation of HCT-116 and HT29 colorectal cancer cells was detected by cell counting kit-8 assay.The ratio of apoptosis of HCT-116 and HT29 cells was measured by annexin Ⅴ/propidium iodide double staining assay.The mitochondrial membrane potential of HCT-116 and HT29 cells was examined by 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-imidacarbocyanine iodide (JC-1) assay.The expression changes of protein kinase B and mammalian target of rapamycin were tested by Western blotting.The target miRNA of circ-VIM was predicted by miRDB software.T-test and chi-square test were performed for statistical analysis. Results The expression of circ-VIM in colorectal cancer tissues was 2.387 ±0.536, which was higher than that in corresponding paracancerous tissues (1.110 ±0.134), and the difference was statistically significant (t =23.096, P <0.01).And the expression levels of circ-VIM were significantly different in patients with different tumor size, TNM stage and lymph node metastasis (all P <0.05).The proliferation of HCT-116 cells and HT29 cells in lenti-circ-VIM group was 0.737 ±0.023 and 0.835 ±0.025, respectively, which were both higher than those in control group (0.449 ±0.020 and 0.531 ±0.019), and the differences were statistically significant (t =20.706 and-15.374, both P <0.01).The proliferation of HCT-116 cells and HT29 cells in lenti-circ-VIM-shRNA group was 0.236 ±0.027 and 0.243 ±0.019, which were lower than those in control group, and the differences were statistically significant (t =24.557 and -23.197, both P <0.01).The ratio of apoptosis of HCT-116 cells and HT29 cells in lenti-circ-VIM-shRNA group was (18.00 ±1.82)％ and (20.80 ±0.61)％, which was higher than those in control group ((6.64 ±2.01)％ and (7.35 ±1.36)％), and the differences were statistically significant (t =8.826 and 17.454, both P <0.01).The fluorescence intensity ratio of JC-1 aggregate and JC-1 monomer of HCT-116 cells and HT29 cells in lenti-circ-VIM-shRNA group was 2.21 ±0.12 and 1.40 ±0.11, which was lower than those in control group (14.54 ±1.00 and 9.24 ±1.18), and the differences were statistically significant (t =-19.558 and-15.685, both P <0.01), which indicated mitochondrial membrane potential decreased.After treated with lenti-circ-VIM-shRNA, the expression of phosphorylated protein kinase B, phosphorylated mammalian target of rapamycin, B-cell lymphoma-2 and mitochondrial cytochrome C at protein level were all down-regulated, however the expression of cytoplasmic cytochrome C, B-cell lymphoma-2 associated X protein and cleaved caspase-3 at protein level were all up-regulated.When the expression of circ-VIM was up-regulated, the expression of miRNA-147b, miRNA-4447 and miRNA-3656 was down-regulated.When the expression of circ-VIM was down-regulated, the expression of miRNA-147b, miRNA-4447 and miRNA-3656 was up-regulated.Conclusion The expression of circ-VIM in colorectal cancer is abnormally increased, which is involved in the proliferation and apoptosis of colorectal cancer cells.

Coactosin-like protein 1 (Cotl1), a member of the actin-depolymerizing factor (ADF)/cofilin family, was first purified from a soluble fraction of Dictyostelium discoideum cells. Neuronal migration requires cytoskeletal remodeling and actin regulation. Although Cotl1 strongly binds to F-actin, the role of Cotl1 in neuronal migration remains undescribed. In this study, we revealed that Cotl1 overexpression impaired migration of both early- and late-born neurons during mouse corticogenesis. Moreover, Cotl1 overexpression delayed, rather than blocked, neuronal migration in late-born neurons. Cotl1 expression disturbed the morphology of migrating neurons, lengthening the leading processes. This study is the first to investigate the function of Cotl1, and the results indicate that Cotl1 is involved in the regulation of neuronal migration and morphogenesis.
Actins ; Animals ; Dictyostelium ; Humans ; Mice ; Morphogenesis ; Neurons

Objective: To analyze the clinicopathological characteristics of papillary thyroid microcarcinoma (PTMC) and risk factors for central lymph node metastasis(CLNM) in PTMC. Methods: The data of 900 patients with PTMC initially treated in our hospital from January 2004 to December 2015 were retrospectively analyzed. Chi-square test and Logistic regression analysis were performed to determine the risk factors for CLNM. Results: CLNM affected 162 (22.9%) of 707 patients treated with central lymph node dissection. Age, maximum tumor size, multifocality, bilaterality, and extracapsular spread (ECS) were significantly correlated with CLNM (all P<0.01). Age<45 years, maximum tumor size>5 mm, multifocality, bilaterality, and extracapsular spread were independently correlated with CLNM. Conclusion A prophylactic central lymph node dissection should be considered in PTMC patients with age<45 years, maximum tumor size>5 mm, multifocality, bilaterality, and extracapsular spread.