The Role of Staphylococcal Biofilm on the Surface of Implants in Orthopedic Infection.

Despite advanced implant sterilization and aseptic surgical techniques, implant-associated infection remains a major challenge for orthopedic surgeries. The subject of bacterial biofilms is receiving increasing attention, probably as a result of the wide acknowledgement of the ubiquity of biofilms in the clinical environment, as well as the extreme difficulty in eradicating them. Biofilm can be defined as a structured microbial community of cells that are attached to a substratum and embedded in a matrix of extracellular polymeric substances (EPS) that they have produced. Biofilm development has been proposed as occurring in a multi-step process: (i) attachment and adherence, (ii) accumulation/maturation due to cellular aggregation and EPS production, and (iii) biofilm detachment (also called dispersal) of bacterial cells. In all these stages, characteristic proteinaceous and non-proteinaceous compounds are expressed, and their expression is strictly controlled. Bacterial biofilm formation around implants shelters the bacteria and encourages the persistence of infection, which could lead to implant failure and osteomyelitis. These complications need to be treated by major revision surgeries and extended antibiotic therapies, which could lead to high treatment costs and even increase mortality. Effective preventive and therapeutic measures to reduce risks for implant-associated infections are thus in urgent need.

Establishing a TNM-like risk classification for metachronous second pulmonary adenocarcinoma in patients with previously resected pulmonary adenocarcinoma.

Background: For metachronous second pulmonary adenocarcinoma (msPAD) in patients with resected PAD, the method to distinguish tumour clonality has not yet been well established, which makes it difficult to determine accurate staging and predict prognosis. Methods: Patients received surgery for the primary and encountered msPAD were recruited into the Surveillance, Epidemiology, and End Results database. We extracted overall survival 1 (OS1) for the primary, overall survival 2 (OS2) for the msPAD, and defined interval survival as the interval time between the first and second PAD. Based on the nomogram and recursive partitioning analysis, a tumor, node, metastasis staging system (TNM)-like risk stratification system was established for OS2 on the premise of suspending the dispute of tumor clonality. Results: A total of 1,045 patients were identified. There is no significant association between interval survival and OS2. A TNM-like risk stratification system was established based on the independent pathological factors for prognosis, including tumor diameter (2nd), node metastasis (2nd), grade (2nd), and extrapulmonary metastasis (2nd). The proposed risk stratification system present well capacity in predicting and stratifying prognosis. Compared with the TNM stage system, the proposed risk stratification system presents a smaller Akaike information criterion (AIC) but larger c-index, and generates higher accuracy to predict prognosis at 160 months of follow-up according to the time-dependent receiver operating curve (ROC) curve. Conclusions: In conclusion, the TNM-like risk stratification appears to be suitable for prognostic prediction and risk stratification for msPAD patients with former PAD resection. This model validates and refines the known classification rules based on the easily collected variables, and highlights potentially clinical implications.

Establishing a prognostic model for metachronous second squamous cell lung cancer in patients with resected squamous cell lung cancer.

BACKGROUND: For metachronous second pulmonary squamous cell carcinoma (msPSC) in patients with resected PSC, the method to distinguish tumour clonality has not yet been well established, which makes it difficult to determine accurate staging and predict prognosis. METHODS: Patients who underwent surgery for first PSC and encountered msPSC were recruited from the Surveillance, Epidemiology, and End Results (SEER) database. We extracted overall survival 1 (OS1) for the first PSC, overall survival 2 (OS2) for msPSC, and interval survival for the time interval between the first and second PSC. The nomogram was calibrated for OS2, and recursive partitioning analysis (RPA) was performed for risk stratification. RESULTS: A total of 617 patients were identified. Several independent prognostic factors were identified and integrated into the nomogram for OS2, including gender, age (2nd), nodal status (1st), node metastasis (2nd), and extrapulmonary metastasis (2nd). The calibration curves showed optimal agreement between the predictions and actual observations, and the c-index was 0.678. Surgery was associated with longer survival for msPSC patients. The prognosis of sublobectomy was comparable and inferior to that of lobectomy in the low- and moderate-risk groups, respectively. Radiotherapy was associated with better outcomes in patients who did not undergo surgery. CONCLUSIONS: The RPA-based clinical nomogram appears to be suitable for the prognostic prediction and risk stratification of OS2 in msPSC. This practical system may help clinicians make decisions and design clinical studies.

Circ_0020123 regulates autophagy, glycolysis, and malignancy by upregulating IRF4 through eliminating miR-193a-3p-mediated suppression of IRF4 in non-small cell lung cancer.

Circular RNA is related to the tumorigenesis of various cancers. Circular RNA hsa_circ_0020123 (circ_0020123) has been uncovered to promote non-small cell lung cancer (NSCLC) progression. However, the regulatory mechanism of circ_0020123 in NSCLC is unclear. The quantitative real-time polymerase chain reaction was employed to detect the levels of circ_0020123, microRNA (miR)-193a-3p, and IRF4 interferon regulatory factor 4 (IRF4) in NSCLC tissues and cells. Loss-of-function experiments were performed to analyze the impacts of circ_0020123 silencing on NSCLC cell malignancy, autophagy, and glycolysis. Protein levels were detected using western blotting. The regulatory mechanism of circ_0020123 was analyzed by bioinformatics analysis and validated by the dual-luciferase reporter, RNA immunoprecipitation assay, and RNA pull-down assay. Xenograft assay was performed to verify the biological function of circ_0020123. We observed an overt elevation in circ_0020123 expression in NSCLC samples and cells, and NSCLC patients with high circ_0020123 expression had a poor prognosis. Circ_0020123 knockdown constrained xenograft tumor growth in vivo and curbed cell proliferation, migration, and glycolysis, and accelerated cell apoptosis and autophagy in NSCLC cells in vitro. Circ_0020123 could absorb miR-193a-3p to regulate IRF4 expression. miR-193a-3p silencing overturned circ_0020123 knockdown-mediated impacts on NSCLC cell malignancy, autophagy, and glycolysis. And IRF4 overexpression reversed miR-193a-3p mimic-mediated effects on NSCLC cell malignancy, autophagy, and glycolysis. Circ_0020123 promoted glycolysis and tumor growth by upregulating IRF4 through sequestering miR-193a-3p in NSCLC, offering a novel mechanism by which circ_0020123 is responsible for the malignancy, autophagy, and glycolysis of NSCLC cells.

Injectable stress relaxation gelatin-based hydrogels with positive surface charge for adsorption of aggrecan and facile cartilage tissue regeneration.

BACKGROUND: Cartilage injury and pathological degeneration are reported in millions of patients globally. Cartilages such as articular hyaline cartilage are characterized by poor self-regeneration ability due to lack of vascular tissue. Current treatment methods adopt foreign cartilage analogue implants or microfracture surgery to accelerate tissue repair and regeneration. These methods are invasive and are associated with the formation of fibrocartilage, which warrants further exploration of new cartilage repair materials. The present study aims to develop an injectable modified gelatin hydrogel. METHOD: The hydrogel effectively adsorbed proteoglycans secreted by chondrocytes adjacent to the cartilage tissue in situ, and rapidly formed suitable chondrocyte survival microenvironment modified by ε-poly-L-lysine (EPL). Besides, dynamic covalent bonds were introduced between glucose and phenylboronic acids (PBA). These bonds formed reversible covalent interactions between the cis-diol groups on polyols and the ionic boronate state of PBA. PBA-modified hydrogel induced significant stress relaxation, which improved chondrocyte viability and cartilage differentiation of stem cells. Further, we explored the ability of these hydrogels to promote chondrocyte viability and cartilage differentiation of stem cells through chemical and mechanical modifications. RESULTS: In vivo and in vitro results demonstrated that the hydrogels exhibited efficient biocompatibility. EPL and PBA modified GelMA hydrogel (Gel-EPL/B) showed stronger activity on chondrocytes compared to the GelMA control group. The Gel-EPL/B group induced the secretion of more extracellular matrix and improved the chondrogenic differentiation potential of stem cells. Finally, thus hydrogel promoted the tissue repair of cartilage defects. CONCLUSION: Modified hydrogel is effective in cartilage tissue repair.

[The new target of Rapamycin: lysosomal calcium channel TRPML1].

Rapamycin (Rap) is an immunosuppressant, which is mainly used in the anti-rejection of organ transplantation. Meanwhile, it also shows great potential in the fields of anticancer, neuroprotection and anti-aging. Rap can inhibit the activity of mammalian target of Rap (mTOR). It activates the transcription factor EB (TFEB) to up-regulate lysosomal function and eliminates the inhibitory effect of mTOR on ULK1 (unc-51 like autophagy activating kinase 1) to promote autophagy. Recent research showed that Rap can directly activate the lysosomal cation channel TRPML1 in an mTOR-independent manner. TRPML1 activation releases lysosomal calcium. Calcineurin functions as the sensor of the lysosomal calcium signal and activates TFEB, thus promoting lysosome function and autophagy. This finding has greatly broadened and deepened our understanding of the pharmacological roles of Rap. In this review, we briefly introduce the canonical Rap-mTOR-ULK1/TFEB signaling pathway, and then discuss the discovery of TRPML1 as a new target of Rap and the pharmacological potential of this novel Rap-TRPML1-Calcineurin-TFEB pathway.

ZBP-89 and Sp1 contribute to Bak expression in hepatocellular carcinoma cells.

BACKGROUND: Kruppel family member zinc binding protein 89 (ZBP-89), also known as ZNF148, regulates Bak expression via binding to GC-rich promoter domain. It is not clear if other GC-rich binding factors, such as Sp family members, can interact with ZBPp-89 on Bak expression. This study aims to elucidate the mechanism of Bak expression regulation by ZBP-89 and Sp proteins, based on in vitro experiment and The Cancer Genome Atlas (TCGA) hepatocellular carcinoma (HCC) data cohort. METHODS: We downloaded TCGA hepatocellular carcinoma (HCC) cohort data to analysis the association of Bak transcription level with ZBP-89 and Sp proteins transcription level. HCC cell lines and liver immortal non-tumour cell lines were used for mechanism study, including western blotting analysis, expression vector mediated gene expression and siRNA interference. RESULTS: Results showed that cancer tissues have higher Bak transcription level compared with adjacent non-cancer tissues. Bak transcription level was correlated with Sp1 and Sp3 expression level, while no correlation was found in ZBP-89 and Bak, neither Sp2 nor Sp4. Mithramycin A (MMA) induced Bak expression in a dose-dependent manner. Western blotting results showed Sp1 overexpression increased Bak expression both in liver immortal non-tumour cells and HCC cells. Interference Sp1 expression could inhibit Bak expression alone. ZBP-89 siRNA suppressed Bak expression even in the presence of MMA treatment and S1 overexpression. Additionally, Bak and Sp1 level were associated with HCC patient survival. CONCLUSIONS: Bak expression required ZBP-89 and Sp1 cooperative regulation simultaneously.

Resection arthrodesis using distraction osteogenesis then plating as a hybrid surgical technique for the management of bone sarcomas of the distal tibia.

PURPOSE: We report the oncological and functional results of limb salvage for bone sarcomas involving the distal tibia using hybrid surgical technique of resection arthrodesis by bone transport then plating. METHODS: Five patients (mean age 18.6 years) with primary distal tibial sarcomas (two Ewing's sarcomas and three osteosarcomas) were treated by this method. The average duration of follow-up is 53 months. All patients accepted distraction osteogenesis with a standard technique using external fixator after wide (four cases) or marginal (one case) resection in the first operation. They were re-admitted for the second surgical treatment (plate insertion and removal of the external fixator) one to two months after they achieved the necessary limb length and desired alignment. RESULTS: Solid union of the lengthening site and sound fusion of the ankle were achieved in all five patients with full and unassisted weight bearing. The mean lengthening was 11.8 cm (range 8-14 cm) and the external fixation index (EFI) was 29.3 days/cm (range 22.8-36.3 days/cm). The mean functional score according to the rating system of the Musculoskeletal Tumour Society was 88% (83-90%). One patient showed poor response to chemotherapy, had local recurrence of sarcoma one year after plating, and was treated with above-knee amputation. CONCLUSIONS: In carefully selected patients with primary distal tibial sarcomas, this hybrid method can effectively eliminate tumor lesion, reconstruct function, and shorten the length of wearing an external fixator by a meticulous conversion to internal fixator.

Mitochondria, calcium and nitric oxide in the apoptotic pathway of esophageal carcinoma cells induced by As2O3.

In order to explore the early apoptotic signal messengers and to search the apoptotic pathway, the morphological and functional changes of mitochondria were examined, and nitric oxide (NO) and calcium ions (Ca2+) were measured in the course of apoptosis in esophageal carcinoma cells induced by As2O3. The esophageal carcinoma cell line SHEEC1, established by HPV in synergy with TPA in our laboratory, were cultured with serum-free medium in a culture flask, 24-well plate and small culture chambers, and added with As2O3 at 1, 3, 5 micromol/l. After 0, 2, 4, 8, 12, 24 h of drug adding the NO were measured from extracellular cultured medium and the SHEEC1 cells were collected from flasks for electron microscopic examination. Fluorescent intensity (FI) of rhodamine 123 (Rho123) labeled cells was detected using laser confocal scanning microscope (LCSM) for evaluation of mitochondrial membrane potential. Intracellular Ca2+ of cells in small culture chambers labeled with Fluo-3 dye were measured using LCSM over time. After adding As2O3, SHEEC1 cells revealed characteristic morphological and functional changes of mitochondria such as hyperplasia, swelling and disruption, accompanying decrease of transmembrane potential (FI of Rho123 decreased). The Ca2+ level increased at once after adding As2O3 and the NO concentration increased step by step till 24 h, then apoptotic morphology of cells occurred. The results suggest that by inducement of As2O3 increasing Ca2+ and NO, the apoptotic signal messengers, will initiate the mitochondria-dependent apoptotic pathway.

Nitric oxide and calcium ions in apoptotic esophageal carcinoma cells induced by arsenite.

AIM: To Quantitatively analyze the nitric oxide (NO) and Ca2+ in apoptosis of esophageal carcinoma cells induced by arsenic trioxide (As2O3). METHODS: The cell line SHEEC1, a malignant esophageal epithelial cell induced by HPV in synergy with TPA in our laboratory, was cultured in a serum-free medium and treated with As2O3. Before and after administration of As2O3, NO production in cultured medium was detected quantitatively using the Griess Colorimetric method. Intracellular Ca2+ was labeled by using the fluorescent dye Fluo3-AM and detected under confocal laser scanning microscope (CLSM), which was able to acquire data in real-time enabling Ca2+ dynamics of individual cells in vitro. The apoptotic cells were examined under electron microscopy. RESULTS: Intracellular concentration of Ca2+ increased from 1.00 units to 1.09-1.38 units of fluorescent intensity at As2O3 treatment and NO products subsequently released from As2O3-treated cells increased from 0.98-1.00 x10(-2)micromol x L(-1) up to 1.48-1.52 x10(-2)micromol x L(-1) and maintained in a high level continuously. Finally apoptosis of cells occurred,chromatin being agglutinated, cells shrunk,nuclei became round and mitochondria swelled. CONCLUSION: Ca2+ and NO increased with cell damage and apoptosis in cells treated by As2O3. The Ca2+ is an initial messenger to the apoptotic pathway. To investigate Ca2+ and NO will be a new direction for studying the apoptotic signaling messenger of the esophageal carcinoma cells induced by As2O3.