Acute epicardial pulmonary vein reconnection: Nondurable transmural lesion or late manifestation of conduction through intercaval bundle.

INTRODUCTION: Acute pulmonary vein reconnection (PVR) via epicardial fibers can be found during observation period after PV isolation, the characteristics and related factors have not been fully studied. We aimed to investigate the prevalence, locations, electrogram characteristics, and ablation parameters related to acute epicardial pulmonary vein reconnection (AEPVR). METHODS: Acute PVR was monitored during observation period after PV isolation. AEPVRs were mapped and distinguished from endocardial conduction gaps. The clinical, electrophysiological characteristics and lesion set parameters were compared between patients with and without PVR. They were also compared among AEPVR, gap-related reconnection, and epicardial PVR in repeat procedures. RESULTS: A total of 56.1% acute PVR were AEPVR, which required a longer waiting period (p < .001) than endocardial gap. The majority of AEPVR were connections from the posterior PV carina to the left atrial posterior wall, followed by late manifestation of intercaval bundle conduction from the right anterior carina to right atrium. AEPVR was similar to epicardial PVR in redo procedures in distribution and electrogram characteristics. Smaller atrium (p < .001), lower impedance drop (p = .039), and ablation index (p = .028) on the posterior wall were independently associated with presence of AEPVR, while lower interlesion distance (p = .043) was the only predictor for AEPVR in acute PVR. An integrated model containing multiple lesion set parameters had the highest predictive ability for AEPVR in receiver operating characteristics analysis. CONCLUSIONS: Epicardial reconduction accounted for the majority of acute PVR. AEPVR was associated with anatomic characteristics and multiple ablation-related parameters, which could be explained by nondurable transmural lesion or late manifestation of conduction through intercaval bundle.

Characteristics, predictors and outcomes of new-onset QT prolongation in sepsis: a multicenter retrospective study.

BACKGROUND: Sepsis-induced myocardial injury is a serious complication of sepsis. QT prolongation is a proarrhythmic state which reflects myocardial injury in a group of heterogeneous disorders. However, the study on the clinical value of QT prolongation in sepsis is limited. METHODS: We aimed to investigate the clinical characteristics and predictors of new-onset QT prolongation in sepsis and its impact on the outcome in a multicenter retrospective cohort study. Electrocardiographic and clinical data were collected from patients with sepsis from the wards and intensive care units of four centers after exclusion of QT-influencing medications and electrolyte abnormalities. Clinical outcomes were compared between patients with and without QT prolongation (QTc > 450 ms). Multivariate analysis was performed to ascertain whether QT prolongation was an independent predictor for 30-day mortality. The factors predicting QT prolongation in sepsis were also analyzed. RESULTS: New-onset QT prolongation occurred in 235/1024 (22.9%) patients. The majority demonstrated similar pattern as type 1 long QT syndrome. Patients with QT prolongation had a higher 30-day in-hospital mortality (P < 0.001), which was also associated with increased tachyarrhythmias including paroxysmal atrial fibrillation or tachycardia (P < 0.001) and ventricular arrhythmia (P < 0.001) during hospitalization. QT prolongation independently predicted 30-day mortality (P = 0.044) after multivariate analysis. History of coronary artery disease (P = 0.001), septic shock (P = 0.008), acute respiratory (P < 0.001), heart (P = 0.021) and renal dysfunction (P = 0.013) were independent predictors of QT prolongation in sepsis. CONCLUSIONS: New-onset QT prolongation in sepsis was associated with increased mortality as well as atrial and ventricular arrhythmias, which was predicted by disease severity and organ dysfunction.

Potential serum metabolites and long-chain noncoding RNA biomarkers for endometrial cancer tissue.

BACKGROUND: Endometrial carcinoma (EC) is one of the most common tumors in the female reproductive system. There are nearly 200 000 new cases every year. It is the third most common gynecological malignant tumor leading to female death. The incidence rate is closely related to lifestyle, and the incidence rate varies in different regions. The incidence rate of EC is ranking the first in the female reproductive system cancer just second only to breast, lung, and colorectal cancer in North America and Europe and the incidence rate of EC is only second, followed by breast cancer and cervical cancer in China. PURPOSE: The potential metabolic markers of endometrial cancer were screened by liquid chromatograph mass spectrometer (LC-MS), and the tissues of patients with hysteromyoma and endometrial cancer were sequenced to explore the relationship between the disease and change in the content of long-chain noncoding RNA (lncRNA). METHODS: Serum and tissue samples were collected from patients with endometrial dysplasia, endometrial cancer stage I, and endometrial cancer stage III. The metabolites in all serum samples were extracted, and the metabolites in all samples were detected by LC-MS/MS technology. The Pareto-scaling method was used for normalization, and the MetaboAnalyst 4.0 software was used for different analyses. The T test between groups showed that p ≤ 0.05 was regarded as the metabolite with a difference. Further, the function of differential metabolites was determined by metabolite function enrichment and co-expression analysis. Meanwhile, the differentially expressed lncRNA was detected by Illumina second-generation high-throughput sequencing technology, and the expression was analyzed by DEGseq software. Different lncRNA were screened according to p < 0.05. LncRNA with significant differences were screened by p < 0.01, q < 0.001, fold change ≥2, and false discovery rate (FDR) ≤0.001. RESULTS: Through synthesis of T test, cluster heatmap, and ROC curve analysis, five biomarkers with potential diagnostic ability were obtained, including 2,3-Pyridinedicarboxylic acid (area under the curve (AUC) = 0.69), Hematommic acid, ethyl ester (AUC = 0.69), Maltitol (AUC = 0.69), 13(S)-HODE (AUC = 0.88), and D-Mannitol (AUC = 0.69) had potential diagnostic ability between EC phase I versus EC phase III. At the same time, lncRNA sequencing results showed that when endometrial atypical hyperplasia continued to change, including LINC00511, PVT1, and IQCH-AS1 (downregulated), and only changed significantly in the endometrial dysplasia group, including MALAT1, CARMN (downregulated) and LINC00648, BISPR, LINC01534, and LINC00930 (upregulated). Moreover, both differential metabolites and differential lncRNA were annotated to the lipid metabolism pathway, suggesting that this pathway played an important role in the occurrence and development of endometrial carcinoma. CONCLUSIONS: It can combine the results of metabolomics and lncRNA sequencing to assist in the early diagnosis of endometrial precancerous lesions and endometrial cancer patients, to enhance the sensitivity and specificity of diagnosis, which has a certain clinical application prospect.

CircRNA PVT1 promotes proliferation and chemoresistance of osteosarcoma cells via the miR-24-3p/KLF8 axis.

OBJECTIVE: To investigate the regulatory effect and mechanism of circular RNA PVT1 (circPVT1) in proliferation and chemoresistance of osteosarcoma (OS) cells. METHODS: The expression of circPVT1 in human OS and adjacent normal tissues was detected. The correlation between circPVT1 expression and clinical features of OS was analyzed. The expressions of circPVT1 and miR-24-3p in OS cells resistant to cisplatin, doxorubicin or methotrexate and parental OS cells were detected after cell transfection. CCK-8 and colony formation assay assessed the viability and proliferative ability of OS cells. qRT-PCR and Western blotting measured the expression of KLF8. Dual-luciferase reporter and RNA pull-down assays verified the targeting relationships of circPVT1/miR-24-3p and miR-24-3p/KLF8. RESULTS: CircPVT1 was over-expressed in OS tissues and cells, and correlated with clinical features of OS. Over-expressed circPVT1 reduced the survival of OS patients. CircPVT1 was up-regulated in chemoresistant OS cells compared to their parental cells. CircPVT1 inhibition suppressed the proliferation and chemoresistance of OS cells. MiR-24-3p was under-expressed in OS cells and further down-regulated in chemoresistant cells. CircPVT1 could bind and down-regulate miR-24-3p. MiR-24-3p overexpression inhibited the proliferation and chemoresistance of OS cells. KLF8 was over-expressed in OS cells and further up-regulated in chemoresistant cells. MiR-24-3p negatively regulated the expression of KLF8. CONCLUSION: CircPVT1 mediates proliferation and chemoresistance of OS cells via the miR-24-3p/KLF8 axis. The findings may provide guidance for clinical treatment of OS.

A new low-profile anatomic locking plate for fixation of comminuted, displaced greater tuberosity fractures of the proximal humerus.

BACKGROUND: Although various implants exist for the fixation of isolated greater tuberosity fractures, few implants are specifically designed for such fractures. The purpose of this study was to investigate the clinical and radiologic outcomes of open reduction-internal fixation with a low-profile anatomic locking plate for comminuted greater tuberosity fractures of the proximal humerus. METHODS: From November 2012 to February 2018, 24 patients with displaced and comminuted isolated greater tuberosity fractures were treated with the new low-profile anatomic locking plate. To determine clinical outcomes, we evaluated active range of motion; the visual analog scale pain score; the Constant-Murley score; the Disabilities of the Arm, Shoulder and Hand score; radiographs; and complications. RESULTS: In all cases, a mean follow-up period of 29.3 months (range, 18-48 months) was completed. All patients achieved bone union with a mean healing time of 11.3 weeks (range, 8-16 weeks). The mean Constant-Murley score was 91.1 points (range, 69-100 points), with a rate of good to excellent results of 95.8%. The average Disabilities of the Arm, Shoulder and Hand score was 9.9 points (range, 2-25 points), and the mean visual analog scale pain score was 1.1 points (range, 0-4 points). Mean active forward flexion, abduction, external rotation, and internal rotation (level) were 157°, 152°, and 40°, and T11, respectively. Postoperatively, 1 patient had persistent shoulder stiffness, and 1 patient had recurrence of shoulder dislocation because of a falling injury during badminton. No serious complications such as subacromial impingement, malunion, nonunion, loss of reduction, or implant failure occurred. CONCLUSIONS: The new low-profile anatomic locking plate was useful for the treatment of comminuted isolated greater tuberosity fractures as it provided reliable stability and satisfactory radiographic and functional results. The described technique is a simple and effective method and provides a new reliable option for the treatment of isolated greater tuberosity fractures.

Screening, Identification, and Characterization of an Affinity Peptide Specific to MT1-MMP and Its Application in Tumor Imaging.

Membrane type-1 matrix metalloproteinase (MT1-MMP) plays a crucial role in many physiological and pathological processes, especially in tumor invasion and metastasis. Bioimaging of this key molecule may find wide usage in various applications. MT-loop is a unique sequence of MT1-MMP and locates in the surface of the protein. In our previous studies, AF7p, an affinity peptide that targeting the MT-loop domain of MT1-MMP, was identified by screening a phage display (Ph.D.) peptide library. However, the target of AF7p is a synthetic sequence which lacked native conformation of the MT-loop region; thus, the binding affinity and specificity in reality may not be optimal. In this study, we considered the 3-dimensional (3-D) conformation of the MT-loop area in the MT1-MMP molecule and designed a novel strategy to screen the Ph.D. peptide library. The peptide we obtained showed a better binding affinity to WT-MT1-MMP than AF7p as observed through enzyme-linked immunosorbent assay (ELISA) and biolayer interferometry (BLI). The new peptide labeled and attached MT1-MMP expression cell lines HT1080 and did not show any toxicity to cells. Furthermore, for in vivo imaging, HT1080 tumor-bearing mice with higher MT1-MMP expression accumulated more Cy5.5-HS7 than mice with MT1-MMP low-expression cell lines A549 at tumor sites, and the half-life of HS7 was longer than that of AF7p, as confirmed by ex vivo imaging of the main organs. These results suggest the feasibility of using the subtraction biopanning strategy to screen the affinity peptide targeting MT-loop regions and HS7 is a superior probe for noninvasively imaging MT1-MMP expression in MT1-MMP-positive tumor models. It provides impetus for further studies to use HS7 in early diagnosis of tumors and in peptide-mediated drugs.

Protective effect of p53 on the viability of intervertebral disc nucleus pulposus cells under low glucose condition.

P53 is a famous cancer suppressor and plays key roles in metabolism. Intervertebral disc (IVD) is the largest avascular cartilaginous structure in humans and its degeneration is a common cause of spine diseases initiated from damaged nucleus pulposus (NP) cells. The potential cause of disc degeneration has been attributed to aging, genetic factors, mechanical factors and nutrition. In this study, we found that p53 decreased and leaked to the cytoplasm in NP cells as the glucose level decreases, in contrast to cancer cells in which p53 increases and concentrates to the nuclei. Comparing with in p53 knockdown NP cells, relative high p53 expression in normal control NP cells inhibited autophagy and the pentose phosphate pathway. Furthermore, the expression of Sox 9 and type II collagen were higher in p53 normal control than p53 knockdown NP cells. Based on these results, we believe that relative high p53 facilitates NP cell viability and integrity.

Effects of Simvastatin and Combination of Simvastatin and Nylestriol on Bone Metabolism in Ovariectomized Rats.

We aim to compare the effects of simvastatin and combination of simvastatin and nylestriol on bone metabolism in ovariectomized (OVX) rats. Fifty healthy Wistar female rats were randomly allocated into 5 groups: sham + saline group (group A), OVX + saline group (group B), OVX + simvastatin (5 mg·kg·d) (group C), OVX + nylestriol (0.01 mg·kg·d) (group D), and OVX + simvastatin (3 mg·kg·d) + nylestriol (0.005 mg·kg·d) (group E). All mice were orally administrated with saline or medicine dissolved in saline for 10 weeks. Body weight of rats before and after the experiment was measured. Twenty-four hours after the experiment, calcium (Ca), creatinine (Cr), and hydroxyproline in urine were detected. Serum levels of osteocalcin (bone Gla-protein, BGP) and alkaline phosphatase (ALP) were measured. Bone mineral density was detected and trabecular bone was observed after the isolation of femur and tibia. Remarkably decreased serum BGP and increased serum ALP levels were detected in group B compared with those in group A. However, notably increased serum BGP and decreased serum ALP levels were found in groups C, D, and E compared with those in group B; femoral and tibial bone mineral density decreased in group B compared with that in group A, but increased in groups C, D, and E compared with that in group B. Simvastatin and combination of simvastatin and nylestriol promote formation of new bone, increase bone density, and improve bone microstructure damage in OVX rats.

DNA binding ability of histone-like protein HPhA is negatively affected by interaction with Pb2+.

The histone-like protein (HPhA) is highly homologous to the eukaryotic histones and has the ability to bind to the DNA molecules. In this study, we tested divalent metal ions Mg(2+), Ca(2+), Zn(2+), Pb(2+) for their effect on the recombinant HPhA (rHPhA)-DNA binding. We found that only Pb(2+) was able to reduce the formation of rHPhA-DNA complex using gel mobility shift assays. Equilibrium dialysis showed that Pb(2+) bound to rHPhA by a 2:1 ratio. The interaction of Pb(2+) and rHPhA was further studied by spectroscopic method including fluorescence, ultraviolet visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopies. Fluorescent spectroscopy results suggested that Pb(2+) and rHPhA formed a complex that caused internal quenching of the fluorescence of the protein at the ground state, and the quenching is predominately static and mixed with dynamic quenching. UV-Vis absorption spectrum results showed Pb(2+) caused a slightly blue shift of the maximum absorption wavelength of rHPhA which indicated the reduction of the protein's hydrophobicity. The CD spectrum further indicated that a reduction of the α-helix content of rHPhA occurred upon binding to Pb(2+). Synchronous fluorescence spectrometry analysis revealed that Pb(2+) was able to affect the polarity of the amino acids that near the Trp and Tyr residues. These results together showed that Pb(2+) interact with the recombinant rHPhA and this interaction negatively affect the ability of rHPhA to form complex with DNA molecules.

Comparative and quantitative proteomic analysis of normal and degenerated human annulus fibrosus cells.

Degeneration of the intervertebral disc (IVD) is a major chronic medical condition associated with back pain. To better understand the pathogenesis of IVD degeneration, we performed comparative and quantitative proteomic analyses of normal and degenerated human annulus fibrosus (AF) cells and identified proteins that are differentially expressed between them. Annulus fibrosus cells were isolated and cultured from patients with lumbar disc herniation (the experimental group, degenerated AF cells) and scoliosis patients who underwent orthopaedic surgery (the control group, normal AF cells). Comparative proteomic analyses of normal and degenerated cultured AF cells were carried out using 2-D electrophoresis, mass spectrometric analyses, and database searching. Quantitative analyses of silver-stained 2-D electrophoresis gels of normal and degenerated cultured AF cells identified 10 protein spots that showed the most altered differential expression levels between the two groups. Among these, three proteins were decreased, including heat shock cognate 71-kDa protein, glucose-6-phosphate 1-dehydrogenase, and protocadherin-23, whereas seven proteins were increased, including guanine nucleotide-binding protein G(i) subunit α-2, superoxide dismutase, transmembrane protein 51, adenosine receptor A3, 26S protease regulatory subunit 8, lipid phosphate phosphatase-related protein, and fatty acyl-crotonic acid reductase 1. These differentially expressed proteins might be involved in the pathophysiological process of IVD degeneration and have potential values as biomarkers of the degeneration of IVD.

Preparation and characterization of a novel injectable strontium-containing calcium phosphate cement with collagen.

PURPOSE: To develop a novel injectable strontium-containing calcium phosphate cement with collagen. METHODS: A novel calcium phosphate bone cement (CPC) was prepared with the addition of strontium element, collagenl, and modified starch; the injectability, solidification time, microstructure, phase composition, compressive strength, anti-collapsibility and histological properties of material were evaluated. RESULTS: The results showed that the material could be injected with an excellent performance; the modified starch significantly improved the anti-washout property of cement; with the liquid to solid ratio of 0.3, the largest compressive strength of cement was obtained (48.0 MPa ± 2.3 MPa); histological examination of repair tissue showed that the bone was repaired after 16 weeks; the degradation of cement was consistent with the new bone growth. CONCLUSION: A novel injectable collagen-strontium-containing CPC with excellent compressive strength and suitable setting time was prepared, with addition of modified starch. The CPC showed a good anti-washout property and the degradation time of the cement met with the new bone growing. This material is supposed to be used in orthopedic and maxillofacial surgery for bone defects.

Differential expression of extracellular-signal-regulated kinase 5 (ERK5) in normal and degenerated human nucleus pulposus tissues and cells.

Extracellular-signal-regulated kinase 5 (ERK5) is a member of the mitogen-activated protein kinase (MAPK) family and regulates a wide variety of cellular processes such as proliferation, differentiation, necrosis, apoptosis and degeneration. However, the expression of ERK5 and its role in degenerated human nucleus pulposus (NP) is hitherto unknown. In this study, we observed the differential expression of ERK5 in normal and degenerated human nucleus pulposus tissues by using immunohistochemical staining and Western blot. Treatment of NP cells with Pro-inflammatory cytokine, TNF-α decreased ERK5 gene expression as well as NP marker gene expression; including the type II collagen and aggrecan. Suppression of ERK5 gene expression in NP cells by ERK5 siRNA resulted in decreased gene expression of type II collagen and aggrecan. Furthermore, inhibition of ERK5 activation by BIX02188 (5µM) decreased the gene expression of type II collagen and aggrecan in NP cells. Our results document the expression of ERK5 in degenerated nucleus pulposus tissues, and suggest a potential involvement of ERK5 in human degenerated nucleus pulposus.

New bone formation and microstructure assessed by combination of confocal laser scanning microscopy and differential interference contrast microscopy.

Bone is a mineralized connective tissue that is continuously and microstructurally remodeled. Altered bone formation and microstructure arise in pathological bone conditions such as osteoporosis, osteonecrosis, fracture repair, and Paget disease of bone. A proper and objective assessment of bone formation and microstructure will provide insight into the understanding of bone pathogenesis and remodeling. Here, new bone formation ex vitro and its microstructure were evaluated in in vivo multiple sequential polychrome-labeled samples using confocal laser scanning microscopy (CLSM), which generated clearer and more reliable images of thick bone sections than conventional fluorescence microscopy (CFM). Intriguingly, fine details of the bone microstructural features, including the mineralization fronts, quiescent versus active osteons, and Volkmann's channel, were elucidated using CLSM, which defines the relationship between morphological changes and function, when combined with differential interference contrast microscopy. Furthermore, CLSM provided objective evaluations of bone formation, such as the ratio of labeled areas of new bone formation in a rabbit model when compared with CFM. Altogether, new bone formation and its microstructure can be evaluated more adequately using a combination of CLSM and DIC microscopies.

A novel method for gas mixing and distribution in multi-chamber embryo incubators.

BACKGROUND: High-quality control of the gas environment in incubators is crucial for in vitro embryo development, which requires high accuracy, fast recovery, and low gas consumption. OBJECTIVE: In this study, we propose a novel gas mixing and distribution system and method as an alternative solution for multi-chamber embryo incubators. METHODS: The system-based embryo incubator enables a controllable gas circulation process and a quantitative supply of CO2 and N2. To determine the optimal parameters for the mixing time and flow rate of the circulated gases, we conducted contrast experiments on the system-based incubator. To evaluate the performance of the gas system in the incubator, we conducted tests under four different initial conditions, simulating various practical application scenarios. Furthermore, we performed a mouse embryo assay to assess the system's effectiveness. RESULTS: The results show that the system achieved a gas concentration accuracy of ± 0.2% (volume fraction) after stabilization, a minimum recovery time of 5 minutes, an average consumption of 8.9 L/d for N2 and 0.83 L/d for CO2 during routine operation, and a blastocyst rate exceeding 90% observed after 96 hours of culture in the incubator. CONCLUSION: The system and method demonstrate a significant advantage in terms of low gas consumption compared to existing incubators, while still maintaining high accuracy and fast recovery.

Efficient soluble expression of secreted matrix metalloproteinase 26 in Brevibacillus choshinensis.

Matrix metalloproteinase 26 (MMP-26) is a novel member of the matrix metalloproteinase family with minimal domain constitution and unknown physiological function. The three-dimensional (3D) structure of the enzyme also remains to be deciphered. Previous studies show that MMP-26 may be expressed in Escherichia coli (E. coli) as inclusion bodies and re-natured with catalytic activity. However, the low re-naturation rate of this method limits its usage in structural studies. In this paper, we tried to clone, express and purify the pro form and catalytic form of MMP-26 (ProMMP-26 and CatMMP-26) in several widely used expression vectors and express the recombinant MMP-26 proteins in E. coli cells. These constructs resulted in insoluble expressions or soluble expressions of MMP-26 with little catalytic activity. We then used Brevibacillus choshinensis (B. choshinensis) as the host system for the soluble and active expression of MMP-26. The enzyme was secreted in soluble form in the supernatant of cell culture medium and purified via a two-step purification process that included Ni(2+) affinity chromatography followed by gel filtration. The yields of purified ProMMP-26 and CatMMP-26 were 12 and 18mg/L, respectively, with high purity and homogeneity. Both ProMMP-26 and CatMMP-26 showed gelatin zymography activity and the purified CatMMP-26 had high enzymatic activity against DQ-gelatin substrate. The large-scale soluble and active protein production for future structural studies of MMP-26 is thus feasible using the B. choshinensis host system.

Corrigendum: Single-cell RNA sequencing reveals the difference in human normal and degenerative nucleus pulposus tissue profiles and cellular interactions.

[This corrects the article DOI: 10.3389/fcell.2022.910626.].

Overexpression of hTERT extends replicative capacity of human nucleus pulposus cells, and protects against serum starvation-induced apoptosis and cell cycle arrest.

The nucleus pulposus (NP) cells are chondrocyte-like cells that are required for the resistance of compressive loads through the synthesis of collagen fibrils and proteoglycan aggrecans, and the generation of a hydrostatic swelling pressure, and thus play an important role in the intervertebral disc. Here, we report the production and characterization of an immortalized human NP cell line from normal NP cells using stable transfection of recombinant human telomerase reverse transcriptase (hTERT) gene. The hTERT-transfected NP cells exhibited morphological characteristics typical of native cells. When compared with the first generation of normal NP cells, the hTERT-transfected NP cells grew faster and had an increased level of IGF-1 and TGF-ß gene expression. They were successfully passaged over 20 generations without significant change in the levels of type II collagen and proteoglycan aggrecan expression. In addition, they showed resistance to serum starvation-induced apoptosis, G1 cell cycle arrest, and gene expression of p53, CCNE1, Fas, and Caspase 3. Moreover, histology revealed that no tumorigenicity of NP cells over expressing hTERT was observed after they were implanted in nude mice. Taken together, an immortalized human NP cell line was established, which has an extended lifespan, retains phenotypic features similar to primary parent NP cells, and should provide a suitable model for studying the biology of NP cells.

Effect of Different Reduction Intramedullary Nails on Spiral Fracture of Middle and Lower Tibia.

Objective: To compare the efficacy of different reduction and intramedullary nailing in the treatment of spiral fracture of middle and lower tibia. Method: A total of 96 patients with spiral fractures of middle and lower tibia treated with intramedullary nails were retrospectively analyzed. The patients were divided into closed functional reduction group, open anatomical reduction group, and closed anatomical reduction group according to different treatment methods. The operation time, intraoperative blood loss, intraoperative fluoroscopy times, fracture healing time, fracture nonunion, wound complications, and healing conditions of the three groups were compared. Results: The operation time and intraoperative fluoroscopy times of patients in the closed anatomical reduction group were significantly increased compared with those in the closed functional reduction group, while the fracture healing time was significantly reduced. However, patients in the open reduction group had significantly more intraoperative blood loss than those in the closed reduction group. The mean follow-up duration of patients was 15.81 ± 3.25 months. Open anatomical reduction was found to have a higher complication rate during follow-up. Specifically, a total of 3 cases recovered after 2 times of surgical treatment. 6 cases showed a small gap at the fracture end which did not affect the function. Conclusion: In the treatment of middle and lower spiral fracture of tibia, closed anatomical reduction and intramedullary nail internal fixation have shorter fracture healing time, less blood loss, and fewer complications, which can act as the first surgical choice. However, open reduction and intramedullary nailing have a high complication rate, which is not recommended.

Expression of Matrix Metalloprotein 13 in Injury Model of Articular Chondrocyte in Rabbits and Analysis of Nano-Drug-Loading System.

This study aimed to analyze the application of a responsive nano-drug-loading system in injury model of articular chondrocyte in rabbits, as well as its effect on expression of matrix metalloprotein 13 (MMP13). The nanoprecipitation method was adopted to prepare camptothecin (CPT)-loaded poly ethylene glycol (PEG)-Poly caprolactone (PCL) and PEG-PCL nanoparticles without CPT. Afterward, the above mentioned nano-drug-loaded system was used to treat an in vitro scratch model of articular chondrocytes. According to different treatment plans, they were divided into groups: G0 (administered CPT-PEG-PCL nanomedicine), G1 (administered PEG-PCL drug), G2 (saline control), and G3 (healthy control). Results showed that the drug-loading capacity and efficiency of CPT-PEG-PCL was higher than that of PEG-PCL. The levels of type II collagen and hyaluronic acid in G0 was higher than that in G1 and G2. The levels of type II collagen and hyaluronic acid in G0 were not obviously different from those in G3. The level of MMP13 in G0 was lower than that in G1 and G2 and the level of tissue inhibitor of metalloproteinases 1 (TIMP1) in G0 was higher than that in G1 and G2. The proliferation activity of cells in G0 was higher than that in G1 and G2, but there was no obvious difference when compared with G3. In conclusion, CPT-PEG-PCL has stronger long-term circulation capacity and drug-loading efficiency. It can effectively up-regulate the levels of type II collagen, hyaluronic acid, and TIMP1, as well as reduce the synthesis and secretion of MMP13 and promote the repair of articular cartilage damage.

Long non-coding RNA ERVK13-1 aggravates osteosarcoma through the involvement of microRNA-873-5p/KLF5 axis.

OBJECTIVE: To explore the effect and mechanism of long noncoding RNA ERVK13-1 on osteosarcoma (OS) cell development by regulation of miR-873-5p/KLF5 axis. METHODS: The expression of ERVK13-1 in the collected tissue was detected by RT-qPCR, and then the relationship between ERVK13-1 expression and clinical characteristics of OS patients was analyzed. After OS cell lines were transfected with miR-873-5p inhibitor, si-ERVK13-1, si-KLF5 or their negative controls, the expression of ERVK13-1, miR-873-5p, and KLF5 in OS cell lines were measured, followed by determination of their effects on cell proliferation, migration, and invasion abilities. Moreover, the binding relationships of ERVK13-1 and miR-873-5p, as well as miR-873-5p and KLF5, were verified by the dual-luciferase reporter gene assay. RESULTS: Highly expressed ERVK13-1 was found in OS tissues, which was closely related to tumor size, tumor node metastasis, and distant metastasis. The overall survival of OS patients with high expression of ERVK13-1 was poorer than those with low expression of ERVK13-1. Elevated ERVK13-1 and KLF5 but suppressed miR-873-5p was observed in the OS cell lines U2OS and MG63. Transfection with miR-873-5p inhibitor enhanced the malignant potentials of OS cells, and transfection with si-ERVK13-1 or si-KLF5 reduced these abilities of OS cells. ERVK13-1 bound to miR-873-5p and KLF5 was a target gene of miR-873-5p. CONCLUSION: The ERVK13-1/miR-873-5p/KLF5 axis confers vital effect on the occurrence and progression of OS, thus providing possible guidance for the clinical treatment of OS.