A noval noninvasive targeted therapy for osteosarcoma: the combination of LIFU and ultrasound-magnetic-mediated SPIO/TP53/PLGA nanobubble.

Purpose: Osteosarcoma (OS) is the most common type of primary malignant bone tumor. Transducing a functional TP53 gene can effectively inhibit OS cell activity. Poly lactic acid-glycolic acid (PLGA) nanobubbles (NBs) mediated by focused ultrasound (US) can introduce exogenous genes into target cells in animal models, but this technique relies on the passive free diffusion of agents across the body. The inclusion of superparamagnetic iron oxide (SPIO) in microbubbles allows for magnetic-based tissue localization. A low-intensity-focused ultrasound (LIFU) instrument was developed at our institute, and different intensities of LIFU can either disrupt the NBs (RLI-LIFU) or exert cytocidal effects on the target tissues (RHI-LIFU). Based on these data, we performed US-magnetic-mediated TP53-NB destruction and investigated its ability to inhibit OS growth when combined with LIFU both in vitro and in vivo. Methods: Several SPIO/TP53/PLGA (STP) NB variants were prepared and characterized. For the in vitro experiments, HOS and MG63 cells were randomly assigned into five treatment groups. Cell proliferation and the expression of TP53 were detected by CCK8, qRT-PCR and Western blotting, respectively. In vivo, tumor-bearing nude mice were randomly assigned into seven treatment groups. The iron distribution of Perls' Prussian blue-stained tissue sections was determined by optical microscopy. TUNEL-DAPI was performed to examine apoptosis. TP53 expression was detected by qRT-PCR and immunohistochemistry. Results: SPIO/TP53/PLGA NBs with a particle size of approximately 200 nm were prepared successfully. For in vitro experiments, ultrasound-targeted transfection of TP53 overexpression in OS cells and efficient inhibition of OS proliferation have been demonstrated. Furthermore, in a tumor-bearing nude mouse model, RLI-LIFU-magnetic-mediated SPIO/TP53/PLGA NBs increased the transfection efficiency of the TP53 plasmid, resulting in apoptosis. Adding RHI-LIFU to the treatment regimen significantly increased the apoptosis of OS cells in vivo. Conclusion: Combining LIFU and US-magnetic-mediated SPIO/TP53/PLGA NB destruction is potentially a novel noninvasive and targeted therapy for OS.

Sugar-sweetened beverage intake and chronic low back pain.

Background: The consumption of sugar-sweetened beverages (SSBs) has become a major public health problem globally. However, no studies have specifically examined the relationship between SSB intake and chronic low back pain (CLBP). Therefore, the present study aimed to investigate the relationship between SSB intake and the risk of CLBP. Methods: This cross-sectional study enrolled participants aged 20 to 69 from the National Health and Nutrition Examination Survey. CLBP was defined as persistent LBP for a consecutive three-month period. Furthermore, SSB intake was assessed and calculated based on dietary recall interviews. Moreover, survey-weighted logistic regression models were employed to evaluate the association between SSB intake and the risk of CLBP, while the restricted cubic spline (RCS) analysis was used to determine whether there were nonlinear associations between SSB intake and CLBP risk. In addition, subgroup analysis was performed using stratification and interaction analysis for all covariates. Results: A total of 4,146 participants (mean age: 43.405 years) were enrolled in the final analysis. The results of survey-weighted logistic regression models showed that SSB consumption was significantly associated with an increased risk of CLBP among individuals aged 20 to 69 years. Moreover, the results of subgroup analysis and interaction analysis demonstrated that the association between SSB intake and the risk of CLBP was modified by smoking status and hypertension. Specifically, the SSB intake-associated CLBP risk was more pronounced among current smokers or individuals with hypertension. Conclusion: Reduction of SSB consumption might contribute to the prevention of CLBP for individuals aged 20 to 69 years. Moreover, current smokers or individuals with hypertension should be more vigilant about the SSB intake-associated CLBP risk. Nevertheless, caution should be exercised when interpreting the results of this study, as further research is necessary to explore the association between SSB consumption and CLBP, given the limitations of the current study.

The effect of perioperative sequential application of multiple doses of tranexamic acid on postoperative blood loss after PLIF: a prospective randomized controlled trial.

BACKGROUND: Tranexamic acid (TXA) has been utilized in spinal surgery to effectively reduce intraoperative blood loss (IBL) and allogeneic blood transfusion rates. However, the traditional TXA regimen might last the entire duration of hyperfibrinolysis caused by surgical trauma, resulting in its limited ability to reduce postoperative blood loss (PBL). Therefore, the aim of this study was to investigate the effectiveness of perioperative sequential administration of multiple doses of TXA in reducing PBL in patients who underwent posterior lumbar interbody fusion (PLIF). METHODS: From October 2022 to June 2023, 231 patients who were diagnosed with lumbar degenerative disease and scheduled to undergo PLIF were prospectively enrolled in the present study. The patients were randomly divided into three groups. Moreover, all patients received an intravenous injection of TXA at a dose of 15 mg/kg 15 min before the surgical skin incision. Patients in Group A received a placebo of normal saline after surgery, while patients in Group B received three additional intravenous injections of TXA at a dose of 15 mg/kg every 24 h. Patients in Group C received three additional intravenous injections of TXA at a dose of 15 mg/kg every 5 h. The primary outcome measure was PBL. In addition, this study assessed total blood loss (TBL), IBL, routine blood parameters, liver and kidney function, coagulation parameters, fibrinolysis indexes, inflammatory indicators, drainage tube removal time (DRT), length of hospital stay (LOS), blood transfusion rate, and incidence of complications for all subjects. RESULTS: The PBL, TBL, DRT, and LOS of Group B and Group C were significantly lower than those of Group A ( P <0.05). The level of D-dimer (D-D) in Group C was significantly lower than that in Group A on the first day after the operation ( P =0.002), and that in Group B was significantly lower than that in Group A on the third day after the operation ( P =0.003). The interleukin-6 levels between the three groups from 1 to 5 days after the operation were in the order of Group A > Group B > Group C. No serious complications were observed in any patient. The results of multiple stepwise linear regression analysis revealed that PBL was positively correlated with incision length, IBL, smoking history, history of hypertension, preoperative fibrinogen degradation product level, and blood transfusion. It was negatively correlated with preoperative levels of fibrinogen, red blood cells, blood urea nitrogen, and age. Compared to female patients, male patients had an increased risk of PBL. Finally, the incidence of PBL was predicted. CONCLUSIONS: Sequential application of multiple doses of TXA during the perioperative period could safely and effectively reduce PBL and TBL, shorten DRT and LOS, reduce postoperative D-D generation, and reduce the postoperative inflammatory response. In addition, this study provided a novel prediction model for PBL in patients undergoing PLIF.

The effect of sequential perioperative intravenous tranexamic acid in reducing postoperative blood loss and hidden blood loss after posterior lumbar interbody fusion: a randomized controlled trial.

Background: Tranexamic acid (TXA) has previously been shown to be effective in reducing intraoperative blood loss (IBL) and transfusion requirements in spine surgery. A conventional TXA regimen is a simple preoperative or intraoperative administration. However, the hyperfibrinolysis caused by surgical trauma lasts at least 24 h, and a single dose of TXA cannot cover the whole process of hyperfibrinolysis. Moreover, its ability to control postoperative blood loss (PBL) may be insufficient. Therefore, this study aimed to explore the effects and safety of sequential perioperative intravenous TXA for reducing bleeding after posterior lumbar interbody fusion (PLIF). Methods: Patients requiring PLIF were randomly divided into two groups. All patients were intravenously injected with 1 g of TXA 15 min before skin resection. Every day after the surgery, 200 ml saline was intravenously injected for 1-3 days in Group A, while Group B received 1 g of TXA instead of saline. The total blood loss (TBL), IBL, PBL, HCT, Hb, blood transfusion volume, inflammation-related indicators, and complications were recorded. Results: TBL, PBL, and hidden blood loss (HBL) in Group B were significantly lower than those in Group A (P < 0.05). The maximum decreases in HCT and Hb in Group B were also significantly lower than those in Group A (P < 0.05), and the drainage removal time (DRT) was sooner in Group B than in Group A (P = 0.003). On the 3rd and 5th days after surgery, the level of CRP in Group B was significantly lower than that in Group A (P < 0.05). Similarly, IL-6 levels were significantly lower in Group B for the first 5 days postoperatively (P < 0.001). Sex, operation time, level of decompression, length of incision, and change in HCT were significant predictors of both TBL and HBL. TBL was also significantly associated with BMI and preoperative fibrinogen, while postoperative TXA was a significant predictor of HBL only. Conclusion: Intravenous injection of 1 g of TXA 15 min before skin resection combined with continuous intravenous injection of 1 g of TXA 1 to 3 days after PLIF can reduce postoperative bleeding and shorten the time to drainage tube removal. In addition, it can also inhibit the postoperative inflammatory response. Clinical trial registration: ChiCTR2200056210.

Clinical application of a modified predeposit autologous red blood cell apheresis in multistage spinal fusion: a single-center retrospective study.

Purpose: This study aimed to evaluate the efficacy and safety of predeposit autologous RBC apheresis (PARA) in patients undergoing multilevel spinal fusion surgery. Methods: A total of 112 patients from January 2020 to June 2022 were divided into two groups according to PARA: the PARA group (n = 51) and the control group (n = 61). The baseline characteristics of the patients, outcomes, transfusion cost, hospitalization cost, length of stay, complications, and changes in hemoglobin and hematocrit levels between the two groups were compared. Results: The baseline characteristics were similar in both groups. No significant differences were found in functional outcomes, including VAS score (p = 0.159), ODI score (p = 0.214), JOA score (p = 0.752), and SF-36 score (p = 0.188) between the PARA and control groups. The amount and rate of intraoperative and perioperative allogeneic RBC transfusion were significantly higher in the control group than in the PARA group (p < 0.001). The postoperative (9.04 ± 3.21 vs. 11.05 ± 3.84, p = 0.004) and total length of stay (15.78 ± 3.79 vs. 17.36 ± 4.08, p = 0.038) in the PARA group were significantly lower than those in the control group, respectively. Despite no difference in hospitalization cost (p = 0.737), the total blood transfusion cost in the PARA group was significantly lower, compared with the control group (p < 0.001). For safety evaluation, there were no significant differences in Hb and Hct levels between the two groups at admission, on postoperative day 1, and postoperative day 3, respectively (p > 0.05). Moreover, the number of postoperative infections in the PARA group was significantly lower than that in the control group (p = 0.038). Conclusion: PARA was a novel, safe, and highly efficient technique for mass autologous blood preparation in a quite short preparation time. This method could significantly reduce the amount of allogeneic blood transfusion and length of stay, which could provide a theoretical basis for following clinical practice about the technique.

LIPUS inhibits inflammation and catabolism through the NF-κB pathway in human degenerative nucleus pulposus cells.

BACKGROUND: Low-intensity pulsed ultrasound (LIPUS) is a safe and noninvasive rehabilitative physical therapy with anti-inflammatory effects. The current study investigated the effect of LIPUS on the inflammation of nucleus pulposus (NP) cells and its underlying mechanism. METHODS: Human NP cells were acquired from lumbar disc herniation tissue samples and cultured for experiments. Human NP cells were treated with LPS and then exposed to LIPUS (15 mW/cm2, 30 mW/cm2 and 60 mW/cm2) for 20 min daily for 3 days to determine the appropriate intensity to inhibit the expression of the inflammatory factors TNF-α and IL-1ß. The gene and protein expression of aggrecan, collagen II, MMP-3 and MMP-9 was measured by real-time PCR and western blotting, respectively. The activity of the nuclear factor-kappa B (NF-κB) pathway was examined by western blotting and immunofluorescence. After pretreatment with the NF-κB inhibitor PDTC, the expression of TNF-α, IL-1ß, MMP-3 and MMP-9 was measured by real-time PCR. RESULTS: LIPUS at intensities of 15 mW/cm2, 30 mW/cm2 and 60 mW/cm2 inhibited LPS-induced NP cell expression of the inflammatory factors TNF-α and IL-1ß, especially at 30 mW/cm2. LIPUS significantly upregulated the gene and protein expression of aggrecan and collagen II and downregulated the gene and protein expression of MMP-3 and MMP-9 in LPS-induced NP cells. The NF-κB signaling pathway was inhibited by LIPUS through inhibiting the protein expression of p-P65 and the translocation of P65 into the nucleus in LPS-induced NP cells. In addition, LIPUS had similar effects as the NF-κB inhibitor PDTC by inhibiting the NF-κB signaling pathway, inflammation and catabolism in LPS-induced human degenerative nucleus pulposus cells. CONCLUSION: LIPUS inhibited inflammation and catabolism through the NF-κB pathway in human degenerative nucleus pulposus cells.

Bavachin Induces Ferroptosis through the STAT3/P53/SLC7A11 Axis in Osteosarcoma Cells.

Ferroptosis is a new form of regulated cell death, which is mediated by intracellular iron. Although it is reported that bavachin has antitumour effects on several tumour cells and prompts the reactive oxygen species (ROS) generation, it is unclear whether ferroptosis can be induced by bavachin in osteosarcoma (OS) cells. In this study, we found that bavachin inhibits the viability of MG63 and HOS OS cell lines along with an increase in the ferrous iron level, ROS accumulation, malondialdehyde overexpression, and glutathione depletion. Moreover, iron chelators (deferoxamine), antioxidants (Vit E), and ferroptosis inhibitors (ferrostatin-1 and liproxstatin-1) reverse bavachin-induced cell death. Bavachin also altered the mitochondrial morphology of OS cells, leading to smaller mitochondria, higher density of the mitochondrial membrane, and reduced mitochondrial cristae. Further investigation showed that bavachin upregulated the expression of transferrin receptor, divalent metal transporter-1, and P53, along with downregulating the expression of ferritin light chain, ferritin heavy chain, p-STAT3 (705), SLC7A11, and glutathione peroxidase-4 in OS cells. More importantly, STAT3 overexpression, SLC7A11 overexpression, and pretreatment with pifithrin-α (P53 inhibitor) rescued OS cell ferroptosis induced by bavachin. The results show that bavachin induces ferroptosis via the STAT3/P53/SLC7A11 axis in OS cells.

LDHA-Mediated Glycolytic Metabolism in Nucleus Pulposus Cells Is a Potential Therapeutic Target for Intervertebral Disc Degeneration.

The intervertebral disc degeneration (IDD) is considered to be an initiator of a series of spinal diseases, among which changes in the nucleus pulposus (NP) are the most significant. NP cells reside in a microenvironment with a lack of blood vessels, hypoxia, and low glucose within the intervertebral disc. Due to the strong activity of HIF-1α, glycolysis is the main pathway for energy metabolism in NP cells. Our previous study found that higher SIRT1 expression is beneficial to delay the degeneration of NP cells. In order to find the downstream genes by which SIRT1 acts on NP cells, we used iTRAQ sequencing to detect the differences between degenerated NP cells overexpressing SIRT1 and a control group (human NP cells were derived from surgery) and found that the expression of LDHA changed in the same direction with SIRT1. This suggests that SIRT1 may delay the degeneration of NP cells by regulating glycolysis. We then used a Seahorse XFe24 analyzer to measure the bioenergetic parameters of NP cells and obtained three findings: (a) glycolysis is the main energy metabolism pathway in NP cells, (b) there is a large difference in ATP production between senescent cells and young cells, and (c) SIRT1 can regulate the production of ATP from glycolysis by regulating LDHA. We also found that SIRT1 in NP cells has a positive regulatory effect on c-Myc which is an upstream gene of LDHA. Through observing IDD-related indicators such as apoptosis, proliferation, senescence, and extracellular matrix, we found that SIRT1 can delay degeneration, and interference with c-Myc and LDHA, respectively, weakens the protective effect of SIRT1. Interfering with LDHA alone can also inhibit glycolysis and accelerate degeneration. Overall, we found that the inhibition of glycolysis in Np cells significantly affects their normal physiological functions and determined that LDHA is a potential therapeutic target for the treatment of IDD.

Overexpression of miR-338-5p in exosomes derived from mesenchymal stromal cells provides neuroprotective effects by the Cnr1/Rap1/Akt pathway after spinal cord injury in rats.

Growing evidence has shown that microRNAs (miRNAs) play crucial roles in the physiopathology of spinal cord injury (SCI). Recent studies have confirmed that miR-338-5p regulates myelination, suggesting a potential role in the treatment of SCI. However, the molecular mechanism of miR-338-5p on SCI is still unknown. Recently, exosomes have emerged as an ideal vector to deliver therapeutic molecules such as miRNAs. Here, we explored the effects of miR-338-5p-overexpressing exosomes derived from bone marrow-derived mesenchymal stromal cells (BMSCs) on SCI. In vivo, a model of contusion SCI in rats was established, and we observed that overexpression of miR-338-5p in exosomes profoundly increased the expression levels of neurofilament protein-M and growth-associated protein-43 and decreased those of myelin-associated glycoprotein and glial fibrillary acidic protein, which provided neuroprotective effects after acute SCI. In an in vitro study, we found that overexpression of miR-338-5p in exosomes repressed cell apoptosis following H2O2-induced oxidative stress injury in PC12 cells. Additionally, we confirmed that cannabinoid receptor 1 (Cnr1) was the target gene of miR-338-5p by dual-luciferase reporter assays and that Rap1 was the downstream gene by the KEGG pathway analysis. We found that miR-338-5p increased cAMP accumulation as a consequence of downregulated expression of the target gene Cnr1, and then, Rap1 was activated by cAMP. Eventually, the activation of the PI3K/Akt pathway attenuated cell apoptosis and promoted neuronal survival by cAMP-mediated Rap1 activation. In brief, these findings showed that exosomes overexpressing miR-338-5p were a promising treatment strategy for SCI.

Is It Necessary to Approach the Severe Osteoporotic Vertebral Biconcave-Shaped Fracture Bilaterally During the Process of PKP?

PURPOSE: The goal of this study was to explore the outcomes of unilateral and bilateral approach percutaneous kyphoplasty (PKP) using CT-guidance in the treatment of severe osteoporotic single-level vertebral biconcave-shaped fracture. METHODS: We retrospectively reviewed 89 patients with severe osteoporotic single-level vertebral biconcave-shaped fracture who had undergone unilateral and bilateral PKP surgeries using CT-guidance at our hospital between June 2013 and June 2019, and followed for at least 1 year. All patients were divided into unilateral (the transverse process-pedicle approach, n = 49) and bilateral (the pedicle approach, n = 40) groups. We collected the clinical and radiological evaluation results during postoperative and last follow-up periods. RESULTS: Our findings revealed that the surgery time for the unilateral group was significantly shorter than that of the bilateral group at P < 0.05. The amount of bone cement and radiation exposure of the unilateral group were significantly lesser than that of the bilateral group (P < 0.05). Relative to preoperative data, the values of the VAS score and Oswestry disability index (ODI) were significantly improved at 1 day after surgery and the last follow-up in the two groups (P < 0.05). Notably, the median height of vertebra at 1 day after surgery and the last follow-up in the unilateral group was significantly restored than that of preoperative data (P < 0.05). However, the median height of vertebra at the same time intervals in the bilateral group showed no significant change compared with preoperative data (P > 0.05). Furthermore, the rate of bone cement leakage and incidence of adjacent-level vertebra fracture were not significantly different in the two groups (P > 0.05). Finally, both groups can obtain an asymmetrical distribution of bone cement in the vertebra. CONCLUSION: Compared to the bilateral PKP, unilateral PKP using CT-guidance in the treatment of the sOVBFs exhibits significantly shorter operation time, lesser radiation dose, and complications. Moreover, unilateral PKP can restore the median height of the vertebral body and eventually obtain a symmetrical distribution of bone cement in the vertebra.

Nampt promotes osteogenic differentiation and lipopolysaccharide-induced interleukin-6 secretion in osteoblastic MC3T3-E1 cells.

The Nicotinamide phosphoribosyltransferase (Nampt)-NAD-Sirt1 pathway modulates processes involved in the pathogenesis of multiple diseases by influencing inflammation. This study aimed to explore the effect of Nampt in osteogenic differentiation and inflammatory response of osteoblastic MC3T3-E1 cells. We developed an in vitro model of lipopolysaccharide (LPS)-induced inflammation and showed that Nampt and Sirt1 were significantly upregulated in LPS-treated MC3T3-E1 cells. LPS induced secretion of the proinflammatory cytokine interleukin-6 (IL-6) and attenuated osteogenic differentiation. Then we transfected cells with adenoviruses to knock down or over express Nampt. Nampt promoted the expression of IL-6, TAK1 and phospho-NF-κB p65 after LPS treatment. Overexpression of Nampt overrode the effect of LPS and rescued LPS-induced inhibition on osteogenic differentiation. FK866, a Nampt inhibitor, had the same inhibitory effect as Nampt knockdown. In addition, Sirt1 suppression by EX527 decreased IL-6 secretion and NF-κB activation without changing the level of Nampt. EX527 also decreased osteogenic differentiation. Incubation with NMN or SRT 1720 also counteract the inhibitory effect of LPS and rescued osteoblast differentiation. Therefore, we demonstrated that Nampt acted both in promoting osteoblast differentiation and in enhancing inflammatory response, mediated by Sirt1 in MC3T3-E1 cells.

A multiplex and fast detection platform for microRNAs based on a self-priming microfluidic chip and duplex-specific nuclease.

MicroRNA expression levels highly correlate with the occurrence, diagnosis and prognosis of disease. However, challenges remain in establishing a multiplex and fast detection method. Here, we developed a multiplex and fast detection platform for microRNAs based on a self-priming microfluidic chip and duplex-specific nuclease. It can detect three types of miRNAs, including miR-100, miR-155, and Let-7a, simultaneously at 50 °C within 1 h. The probes are pre-introduced into the chip using the self-priming method and cross-contamination can be avoided by using a screw valve. The reagent consumption and cost have been largely reduced in this work compared to the traditional detection method. This chip also exhibits good quantitative performance and specificity. As a proof of concept, we detect three types of microRNAs from different cancer cell lines, which demonstrates its potential in real sample analysis. In summary, this microfluidic chip shows great advantages in multiplex, fast and simple detection of microRNAs, and possesses great potential in the early diagnosis of miRNA-related diseases, especially for point-of-care application.

SDF1/CXCR4 axis facilitates the angiogenesis via activating the PI3K/AKT pathway in degenerated discs.

Symptomatic degenerative disc disease (DDD) is considered the leading cause of chronic lower back pain (LBP). As one of the main features of intervertebral disc degeneration (IDD), vascular ingrowth plays a crucial role in the progression of LBP. Stromal cell­derived factor 1 (SDF1) and its receptor C­X­C receptor 4 (CXCR4) were reported to be overexpressed in the degenerated intervertebral discs, suggesting that they may be involved in the pathogenesis of IDD. Moreover, SDF1 has been identified to induce neovascularization in rheumatoid arthritis disease. However, the roles of the SDF1/CXCR4 axis in the neovascularization of IDD remain unclear. Therefore, the objective of the present study was to elucidate whether the SDF1/CXCR4 axis takes part in neovascularization in degenerated intervertebral discs and its underlying mechanisms. Adenovirus infection was used to upregulate SDF1 expression in primary nucleus pulposus cells (NPCs). The effects of SDF1 on the proliferation and angiogenesis of vascular endothelial cells (VECs) were assessed by Cell Counting Kit­8 and tube formation assays after VECs were treated with the supernatants derived from SDF1 overexpressed or not treated NPCs. Transwell chambers using the supernatants from NPCs as chemokines were applied to assess VEC migration and invasion. AMD3100, MK­2206 and SF1670 were used to antagonize CXCR4, AKT serine/threonine kinase 1 (AKT) and phosphatase and tensin homolog (PTEN) in VECs. The results revealed that SDF1 overexpression significantly increased the ratio of phosphorylated AKT to AKT and decreased PTEN expression in NPCs, as well as enhanced the proliferation, migration, invasion and angiogenesis abilities of VECs. However, these effects induced by SDF1 overexpression in NPCs were all reversed when VECs were pretreated with AMD3100 or MK­2206, whereas enhanced by SF1670 treatment. Collectively, the present study indicated that enhancement of the SDF1/CXCR4 axis in NPCs can significantly accelerate angiogenesis by regulating the PTEN/phosphatidylinositol­3­kinase/AKT pathway.

A Self-Priming Digital Polymerase Chain Reaction Chip for Multiplex Genetic Analysis.

Digital PCR (polymerase chain reaction) is a powerful and attractive tool for the quantification of nucleic acids. However, the multiplex detection capabilities of this system are limited or require expensive instrumentation and reagents, all of which can hinder multiplex detection goals. Here, we propose strategies toward solving these issues regarding digital PCR. We designed and tested a self-priming digital PCR chip containing 6-plex detection capabilities using monochrome fluorescence, which has six detection areas and four-layer structures. This strategy achieved multiplex digital detection by the use of self-priming to preintroduce the specific reaction mix to a certain detection area. This avoids competition when multiple primer pairs coexist, allowing for multiplexing in a shorter time while using less reagents and low-cost instruments. This also prevents the digital PCR chip from experiencing long sample introduction time and evaporation. For further validation, this multiplex digital PCR chip was used to detect five types of EGFR (epidermal growth factor receptor) gene mutations in 15 blood samples from lung cancer patients. We conclude that this technique can precisely quantify EGFR mutations in high-performance diagnostics. This multiplex digital detection chip is a simple and inexpensive test intended for liquid biopsies. It can be applied and used in prenatal diagnostics, the monitoring of residual disease, rapid pathogen detection, and many other procedures.

Minimally invasive treatment of old femoral fractures in adults.

OBJECTIVE: Extensive incision associated with large-scale callus exfoliation and internal fixation is the common therapeutic approach employed by the majority of orthopaedists in the treatment of old femoral fractures. Inspired by the surgical techniques of intramedullary fixation and reduction by traction, the present study attempted to treat old femoral fractures with minimally invasive methods utilising the principles of biological osteosynthesis (BO). METHODS: A retrospective analysis involving 16 patients with old femoral fractures treated with combined traction, small incision, limited callus treatment, reduction by leverage and intramedullary fixation was conducted. The operative effect was evaluated by the operation time, intraoperative blood loss, bone grafting, healing time of fractures during follow-up, VAS score, and Harris hip score. RESULTS: Intraoperative observation revealed an average operation time of 1.53 ± 0.34 h and average blood loss of 268.13 ± 97.29 ml without bone grafting in all patients. All enrolled patients had outcomes resulting in effective fixation restoration of limb alignment. Of the 16 enrolled patients, 13 patients completed follow-up with an average follow-up time of 7.42 ± 3.29 months. The average healing time for proximal femoral fractures was 3 months. The average healing time of femoral shaft fractures was 4 ± 1.09 months; two of these cases took 4 months to heal, whereas 1 case demonstrated a delayed healing time of 6 months. The VAS score was 1.15 ± 1.70, 1 patient experienced sciatica, and the Harris hip score was 92.92 ± 5.42. There were no complications of malunion, nonunion or infection among any of the patients who completed follow-up. CONCLUSIONS: Minimally invasive treatment is feasible for most patients with old femoral fractures of the trochanter and femoral shaft. This finding is consistent with BO principles, thereby providing a possible new method for the treatment of old femoral fractures.

SDF1/CXCR7 Signaling Axis Participates in Angiogenesis in Degenerated Discs via the PI3K/AKT Pathway.

Degenerative disc disease (DDD) is the main cause of low back pain, and the ingrowth of new blood vessels is one of its pathological features. The stromal cell-derived factor 1 (SDF1)/CXCR7 signaling axis plays a role in these physiological and pathological activities. The aims of this study were to explore whether this signaling axis participates in the angiogenesis of degenerated intervertebral discs (IVDs) and to define its underlying mechanism. In this study, we cocultured human nucleus pulposus cells (NPCs) and vascular endothelial cells (VECs) and regulated the expression of SDF1/CXCR7 to investigate the effect of VEC angiogenesis by NPCs. The results revealed that angiogenesis was enhanced with increased SDF1 and that angiogenesis was weakened with the inhibition of CXCR7. We found that PI3K/AKT was involved in the downstream pathway in the coculture. VEC angiogenesis induction by NPCs was enhanced with an increase in pAKT or a decrease in PTEN. We conclude that the SDF1/CXCR7 signaling axis plays a role in the angiogenesis of degenerated IVD through the PI3K/AKT pathway.

Percutaneous Endoscopic Lumbar Diskectomy for Axillar Herniation at L5-S1 via the Transforaminal Approach Versus the Interlaminar Approach: A Prospective Clinical Trial.

OBJECTIVE: To evaluate the results of percutaneous endoscopic transforaminal diskectomy (PETD) in comparison with percutaneous endoscopic interlaminar diskectomy (PEID) for axillar herniation at L5-S1. METHODS: From January 2017 to March 2018, 80 patients admitted with axillar herniation at L5-S1 were randomly recruited into 2 groups: 40 cases in the PETD group and 40 in the PEID group. Each group separately underwent PETD or PEID. Patient sex, age, body mass index, axillar herniation size, number of C-arm fluoroscopies, operation time, postoperative bed time, complications, and clinical effect were compared. Both groups were followed-up using the Oswestry Disability Index (ODI), visual analog scale (VAS), and Macnab criteria. RESULTS: Except for 1 case in the PETD group that switched to the PEID group, the patients completed the study as expected. All patients were followed-up. Preoperative demographics were not significantly different (P > 0.05) between the 2 groups. The mean number of C-arm fluoroscopies (12.44 ± 3.21) and the operation time (66.49 ± 16.29 minutes) of the PETD group were significantly improved compared with the PEID group (number of fluoroscopies: 3.41 ± 0.81, P < 0.001; operation time: 53.56 ± 10.82 minutes, P < 0.001), but the postoperative bed rest time and complication rate were not (P > 0.05). The postoperative ODI and VAS scores were obviously improved in both groups when compared with preoperation (P < 0.001). There were no significant differences between the 2 groups in the Macnab criteria or VAS and ODI scores at the same time point (P > 0.05). CONCLUSIONS: For axillar herniation at L5-S1, PEID can ignore the anatomic obstruction with advantages including a shorter operation time and less intraoperative radiation exposure. PETD has a clinical effect similar to that of PEID, but the process of it is more dangerous and harder than PEID.

Expression and effects of leukemia inhibitory factor on nucleus pulposus degeneration.

Leukemia inhibitory factor (LIF) is a multifunctional cytokine. The present study aimed to determine the expression and effects of LIF on nucleus pulposus generation. Degenerated nucleus pulposus samples were obtained from animal models and patients with lumbar intervertebral disc herniation. Degradation scores of intervertebral discs were evaluated via magnetic resonance imaging (MRI) and histology, and the protein expression levels of LIF were detected. Furthermore, cultured primary human degenerated nucleus pulposus cells (DNPCs) were stimulated with various concentrations of recombinant human LIF protein (rhLIF), and aggrecan and collagen type II α1 (COL2α1) protein expression levels were detected by western blotting. In addition, aggrecan expression was determined by toluidine blue staining. The effects of rhLIF on proliferation and apoptosis of DNPCs were evaluated by Cell Counting Kit­8 and flow cytometry, respectively. The results revealed that the degradation scores of intervertebral discs were significantly associated with modeling time, as determined by MRI and histology. In addition, the protein expression levels of LIF were initially increased in patients with lumbar disc herniation and in rabbit models, particularly in the 2­week modeling group; however, its expression decreased with the progression of disc degeneration. Notably, LIF expression in each modeling group was higher than that in the control and 0 week modeling group. The in vitro study revealed that the protein expression levels of aggrecan and COL2α1 were significantly increased in response to rhLIF, in a dose­dependent manner, and statistical differences were identified between the treatment groups and control group. The results of toluidine blue staining were consistent with this finding. Although rhLIF had no effect on proliferation, it inhibited apoptosis of DNPCs in a concentration­dependent manner. In conclusion, LIF was upregulated during the process of intervertebral disc degeneration, and may promote the expression of extracellular matrix components. It may also be hypothesized that LIF acts as a potential protective factor by inhibiting apoptosis of DNPCs without affecting cell proliferation.

Leukemia inhibitory factor promotes extracellular matrix synthesis in degenerative nucleus pulposus cells via MAPK-ERK1/2 signaling pathway.

Extracellular matrix (ECM) anabolism and catabolism imbalance is key feature of chondrocyte and intervertebral disc nucleus pulposus (NP) cell degeneration. The role of LIF as a multifunctional cytokine in the ECM metabolism of chondrocytes is controversial, but no relevant research in the ECM metabolism of NP cells. This study aimed to explore the biofunction and related mechanisms of LIF in the degenerative NP cells. We obtained an increase in the expression of LIF in the human degenerated NP specimens. The addition of recombinant human leukemia inhibitory factor (rhLIF) to the degenerated NP cells cultured in vitro was found to stimulate the synthesis of ECM, and rhLIF could activate the ERK1/2 signaling pathway. However, coculture with PD98059, a signal inhibitor of ERK1/2, blocked the effect of rhLIF on the synthesis of ECM. To furtherly clarify the role of LIF, we carried out animal experiments and found that rhLIF treatment could successfully delay the degree of degeneration of the intervertebral disc in a rabbit model; but with the addition of PD98059, the function of rhLIF for degeneration protection disappeared. In summary, this study demonstrates that LIF plays a role in promoting ECM synthesis in the degenerated NP cells as a protective role in intervertebral disc degeneration (IDD), which is related to the activation of ERK1/2 signaling pathway.

PINK1 protects against oxidative stress induced senescence of human nucleus pulposus cells via regulating mitophagy.

Intervertebral disc degeneration (IDD) is closely related with aging, whereas mitochondrial dysfunction is a common feature of aging in which results cell senescence. Phosphatase and tensin homolog (PTEN)-induced putative kinase protein 1 (PINK1) is a mitochondrial-targeted serine/threonine kinase, which plays a protective role against mitochondrial dysfunction with mitochondrial quality control by activating PINK1/Parkin mediated mitophagy. This study aimed to investigate the protective role of PINK1 against mitochondrial dysfunction and human nucleus pulposus cell (NPC) senescence. We found that mitochondrial dysfunction and NPC senescence could be induced under sublethal oxidative stress by 150 µM H2O2. Moreover, down-regulation of PINK1 tended to aggravate NPC senescence under oxidative stress. Therefore, mitophagy was evaluated in NPCs to further reveal the underlying mechanism. Results showed that sublethal oxidative stress induced mitochondria dysfunction and mitophagy in NPCs. Furthermore, depletion of PINK1 utilizing short hairpin RNA targeting PINK1 (PINK1-shRNA) impaired mitophagy, and exasperated NPC senescence under oxidative stress. In summary, these results suggested that PINK1 played as a protective role in clearance of damaged mitochondrial and alleviating cell senescence under oxidative stress, whose mechanism is associated with regulating mitophagy. These findings may provide a better understanding in pathomechanism of IDD and potential therapeutic approaches for IDD treatment.