Construction of a risk stratification model integrating ctDNA to predict response and survival in neoadjuvant-treated breast cancer.

BACKGROUND: The pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) of breast cancer is closely related to a better prognosis. However, there are no reliable indicators to accurately identify which patients will achieve pCR before surgery, and a model for predicting pCR to NAC is required. METHODS: A total of 269 breast cancer patients in Shandong Cancer Hospital and Liaocheng People's Hospital receiving anthracycline and taxane-based NAC were prospectively enrolled. Expression profiling using a 457 cancer-related gene sequencing panel (DNA sequencing) covering genes recurrently mutated in breast cancer was carried out on 243 formalin-fixed paraffin-embedded tumor biopsies samples before NAC from 243 patients. The unique personalized panel of nine individual somatic mutation genes from the constructed model was used to detect and analyze ctDNA on 216 blood samples. Blood samples were collected at indicated time points including before chemotherapy initiation, after the 1st NAC and before the 2nd NAC cycle, during intermediate evaluation, and prior to surgery. In this study, we characterized the value of gene profile mutation and circulating tumor DNA (ctDNA) in combination with clinical characteristics in the prediction of pCR before surgery and investigated the prognostic prediction. The median follow-up time for survival analysis was 898 days. RESULTS: Firstly, we constructed a predictive NAC response model including five single nucleotide variant (SNV) mutations (TP53, SETBP1, PIK3CA, NOTCH4 and MSH2) and four copy number variation (CNV) mutations (FOXP1-gain, EGFR-gain, IL7R-gain, and NFKB1A-gain) in the breast tumor, combined with three clinical factors (luminal A, Her2 and Ki67 status). The tumor prediction model showed good discrimination of chemotherapy sensitivity for pCR and non-pCR with an AUC of 0.871 (95% CI, 0.797-0.927) in the training set, 0.771 (95% CI, 0.649-0.883) in the test set, and 0.726 (95% CI, 0.556-0.865) in an extra test set. This tumor prediction model can also effectively predict the prognosis of disease-free survival (DFS) with an AUC of 0.749 at 1 year and 0.830 at 3 years. We further screened the genes from the tumor prediction model to establish a unique personalized panel consisting of 9 individual somatic mutation genes to detect and analyze ctDNA. It was found that ctDNA positivity decreased with the passage of time during NAC, and ctDNA status can predict NAC response and metastasis recurrence. Finally, we constructed the chemotherapy prediction model combined with the tumor prediction model and pretreatment ctDNA levels, which has a better prediction effect of pCR with the AUC value of 0.961. CONCLUSIONS: In this study, we established a chemotherapy predictive model with a non-invasive tool that is built based on genomic features, ctDNA status, as well as clinical characteristics for predicting pCR to recognize the responders and non-responders to NAC, and also predicting prognosis for DFS in breast cancer. Adding pretreatment ctDNA levels to a model containing gene profile mutation and clinical characteristics significantly improves stratification over the clinical variables alone.

Algorithmic Fairness of Machine Learning Models for Alzheimer Disease Progression.

Importance: Predictive models using machine learning techniques have potential to improve early detection and management of Alzheimer disease (AD). However, these models potentially have biases and may perpetuate or exacerbate existing disparities. Objective: To characterize the algorithmic fairness of longitudinal prediction models for AD progression. Design, Setting, and Participants: This prognostic study investigated the algorithmic fairness of logistic regression, support vector machines, and recurrent neural networks for predicting progression to mild cognitive impairment (MCI) and AD using data from participants in the Alzheimer Disease Neuroimaging Initiative evaluated at 57 sites in the US and Canada. Participants aged 54 to 91 years who contributed data on at least 2 visits between September 2005 and May 2017 were included. Data were analyzed in October 2022. Exposures: Fairness was quantified across sex, ethnicity, and race groups. Neuropsychological test scores, anatomical features from T1 magnetic resonance imaging, measures extracted from positron emission tomography, and cerebrospinal fluid biomarkers were included as predictors. Main Outcomes and Measures: Outcome measures quantified fairness of prediction models (logistic regression [LR], support vector machine [SVM], and recurrent neural network [RNN] models), including equal opportunity, equalized odds, and demographic parity. Specifically, if the model exhibited equal sensitivity for all groups, it aligned with the principle of equal opportunity, indicating fairness in predictive performance. Results: A total of 1730 participants in the cohort (mean [SD] age, 73.81 [6.92] years; 776 females [44.9%]; 69 Hispanic [4.0%] and 1661 non-Hispanic [96.0%]; 29 Asian [1.7%], 77 Black [4.5%], 1599 White [92.4%], and 25 other race [1.4%]) were included. Sensitivity for predicting progression to MCI and AD was lower for Hispanic participants compared with non-Hispanic participants; the difference (SD) in true positive rate ranged from 20.9% (5.5%) for the RNN model to 27.8% (9.8%) for the SVM model in MCI and 24.1% (5.4%) for the RNN model to 48.2% (17.3%) for the LR model in AD. Sensitivity was similarly lower for Black and Asian participants compared with non-Hispanic White participants; for example, the difference (SD) in AD true positive rate was 14.5% (51.6%) in the LR model, 12.3% (35.1%) in the SVM model, and 28.4% (16.8%) in the RNN model for Black vs White participants, and the difference (SD) in MCI true positive rate was 25.6% (13.1%) in the LR model, 24.3% (13.1%) in the SVM model, and 6.8% (18.7%) in the RNN model for Asian vs White participants. Models generally satisfied metrics of fairness with respect to sex, with no significant differences by group, except for cognitively normal (CN)-MCI and MCI-AD transitions (eg, an absolute increase [SD] in the true positive rate of CN-MCI transitions of 10.3% [27.8%] for the LR model). Conclusions and Relevance: In this study, models were accurate in aggregate but failed to satisfy fairness metrics. These findings suggest that fairness should be considered in the development and use of machine learning models for AD progression.

ReMiND: Recovery of Missing Neuroimaging using Diffusion Models with Application to Alzheimer's Disease.

Objective: Missing data is a significant challenge in medical research. In longitudinal studies of Alzheimer's disease (AD) where structural magnetic resonance imaging (MRI) is collected from individuals at multiple time points, participants may miss a study visit or drop out. Additionally, technical issues such as participant motion in the scanner may result in unusable imaging data at designated visits. Such missing data may hinder the development of high-quality imaging-based biomarkers. Furthermore, when imaging data are unavailable in clinical practice, patients may not benefit from effective application of biomarkers for disease diagnosis and monitoring. Methods: To address the problem of missing MRI data in studies of AD, we introduced a novel 3D diffusion model specifically designed for imputing missing structural MRI (Recovery of Missing Neuroimaging using Diffusion models (ReMiND)). The model generates a whole-brain image conditional on a single structural MRI observed at a past visit or conditional on one past and one future observed structural MRI relative to the missing observation. Results: Experimental results show that our method can generate high-quality individual 3D structural MRI with high similarity to ground truth, observed images. Additionally, images generated using ReMiND exhibit relatively lower error rates and more accurately estimated rates of atrophy over time in important anatomical brain regions compared with two alternative imputation approaches: forward filling and image generation using variational autoencoders. Conclusion: Our 3D diffusion model can impute missing structural MRI data at a single designated visit and outperforms alternative methods for imputing whole-brain images that are missing from longitudinal trajectories.

Association of Long-Term Exposure to Ambient Fine Particulate Matter with Atherosclerotic Cardiovascular Disease Incidence Varies across Populations with Different Predicted Risks: The China-PAR Project.

Previous studies have established a significant link between ambient fine particulate matter (PM2.5) exposure and atherosclerotic cardiovascular disease (ASCVD) incidence, but whether this association varies across populations with different predicted ASCVD risks was uncertain previously. We included 109,374 Chinese adults without ASCVD at baseline from the Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR) project. We obtained PM2.5 data of participants' residential address from 2000 to 2015 using a satellite-based spatiotemporal model. Participants were classified into low-to-medium and high-risk groups according to the ASCVD 10-year and lifetime risk prediction scores. Hazard ratios (HRs) and 95% confidence intervals (CIs) for PM2.5 exposure-related incident ASCVD, as well as the multiplication and additive interaction, were calculated using stratified Cox proportional hazard models. The additive interaction between risk stratification and PM2.5 exposure was estimated by the synergy index (SI), the attributable proportion due to the interaction (API), and the relative excess risk due to interaction (RERI). Over the follow-up of 833,067 person-years, a total of 4230 incident ASCVD cases were identified. Each 10 µg/m3 increment of PM2.5 concentration was associated with 18% (HR: 1.18; 95% CI: 1.14-1.23) increased risk of ASCVD in the total population, and the association was more pronounced among individuals having a high predicted ASCVD risk than those having a low-to-medium risk, with the HR (95% CI) of 1.24 (1.19-1.30) and 1.11 (1.02-1.20) per 10 µg/m3 increment in PM2.5 concentration, respectively. The RERI, API, and SI were 1.22 (95% CI: 0.62-1.81), 0.22 (95% CI: 0.12-0.32), and 1.37 (95% CI: 1.16-1.63), respectively. Our findings demonstrate a significant synergistic effect on ASCVD between ASCVD risk stratification and PM2.5 exposure and highlight the potential health benefits of reducing PM2.5 exposure in Chinese, especially among those with high ASCVD risk.

Pivotal roles of tumor-draining lymph nodes in the abscopal effects from combined immunotherapy and radiotherapy.

BACKGROUND: Currently, due to synergy enhancement of anti-tumor effects and potent stimulation of abscopal effects, combination therapy with irradiation and programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) immune checkpoint inhibition (immuno-radiotherapy, iRT) has revolutionized the therapeutic guidelines. It has been demonstrated that tumor-draining lymph nodes (TDLN) are essential for effective antitumor immunity induced by radiotherapy, immunotherapy, or iRT. Given that the function of TDLN in iRT remains unclear, this study aimed to investigate the function and mechanism of TDLN in iRT-induced abscopal effects. METHODS: The function of TDLN was evaluated using unilateral or bilateral MC38 and B16F10 subcutaneous tumor models with or without indicated TDLN. The flow cytometry, multiple immunofluorescence analysis, and NanoString analysis were utilized to detect the composition and function of the immune cells in the primary and abscopal tumor microenvironment. Additionally, we tempted to interrogate the possible mechanisms via RNA-sequencing of tumor-infiltrating lymphocytes and TDLN. RESULTS: TDLN deficiency impaired the control of tumor growth by monotherapy. Bilateral TDLN removal rather than unilateral TDLN removal substantially curtailed iRT-stimulated anti-tumor and abscopal effects. Furthermore, in the absence of TDLN, the infiltration of CD45+ and CD8+ T cells was substantially reduced in both primary and abscopal tumors, and the anti-tumor function of CD8+ T cells was attenuated as well. Additionally, the polarization of tumor-associated macrophages in primary and abscopal tumors were found to be dependent on intact bilateral TDLN. RNA-sequencing data indicated that impaired infiltration and anti-tumor effects of immune cells partially attributed to the altered secretion of components from the tumor microenvironment. CONCLUSIONS: TDLN play a critical role in iRT by promoting the infiltration of CD8+ T cells and maintaining the M1/M2 macrophage ratio.

Study on the degradation of tetracycline in wastewater by micro-nano bubbles activated hydrogen peroxide.

Recently, the micro-nano bubble (MB) technology has attracted people's attention due to its special advantages. Here, we carried out the technology of combining MB and hydrogen peroxide (MB/H2O2) to achieve efficient degradation of tetracycline wastewater. The effect of MB/H2O2 technology on the degradation efficiency of tetracycline was deeply analysed by investigating the reaction time, H2O2 dosage, pH and MB inlet flow. The results showed that the degradation rate of tetracycline hydrochloride by MB/H2O2 technology can reach 92.43%, which is 9.44 and 3.94 times that of MB and H2O2 alone. Through electron spin resonance (ESR) analysis and free radical quenching experiments, a possible mechanism for MB/H2O2 technology to efficiently degrade TC was proposed. In the MB/H2O2 system, the high temperature and high pressure environment generated when MB ruptures can activate H2O2 to obtain a higher number of active oxygen species. •OH is the main reactive oxygen radical in the process of MB/H2O2 degradation of TC, followed by HO2•/•O2-. In addition, the possible intermediate products of the oxidation TC process were identified by HPLC-MS technology. Under the action of •OH and HO2•/•O2- free radicals, TC molecules undergo demethylation and hydroxylation, ring-opening reactions, isomerization, deethylation, deacylation, deamination and dehydration reactions to generate intermediate products and finally convert them into CO2 and H2O. The development of MB/H2O2 technology can potentially be used to efficiently remove TC substances in the water environment and provide a new method for water purification.

Mutant Allele Frequency-Based Intra-Tumoral Genetic Heterogeneity Related to the Tumor Shrinkage Mode After Neoadjuvant Chemotherapy in Breast Cancer Patients.

The shrinkage mode of tumor extent after neoadjuvant chemotherapy (NAC) is an important index to evaluate the odds of breast-conserving surgery. However, there is no sufficient measurement to predict the shrinkage mode after NAC. In this study, we analyzed 24 patients' formalin-fixed, paraffin-embedded samples before and after treatment and analyzed 456 cancer-related genes panel by using target next-generation sequencing. Meanwhile, the pathological shrinkage mode was reconstructed in three dimensions after surgery, and the genetic heterogeneity level was estimated by mutant-allele tumor heterogeneity (MATH). We measured the genetic intra-tumor heterogeneity and explored its correlation with the shrinkage mode after NAC. A total of 17 matched pair samples of primary tumor tissue and residual tumor tissue were successfully accessed. It was found that the most common mutated genes were TP53 and PIK3CA in both samples before and after NAC, and no recurrent mutations were significantly associated with the shrinkage mode. Besides, the MATH value of formalin-fixed, paraffin-embedded samples before and after NAC was analyzed by the area under the curve of the receiver operating characteristic, and it is feasible to classify patients into concentric shrinkage mode and non-concentric shrinkage mode in NAC based on the MATH threshold of 58. Our findings indicate that the MATH value was associated with the shrinkage mode of breast cancer in a non-linear model. Patients with the MATH value below the threshold of 58 before and after NAC displayed a concentric shrinkage mode. The area under the curve was 0.89, with a sensitivity of 0.69 and specificity of 1. Our study might provide a promising application of intra-tumor heterogeneity that is measured by MATH to make a choice of surgery.

Relationship between HLA-DRB1 gene polymorphism and breast cancer: A protocol for systematic review and meta-analysis.

BACKGROUND: Breast cancer is one of the common malignant tumors in women, which seriously affects women's physical and mental health and even life-threatening. The occurrence and development of breast cancer are closely related to genetic factors. Many studies have shown that human leukocyte antigen DRB1 is associated with the development of breast cancer, but lack evidence. This study aims to systematically evaluate the relationship between HLA-DRB1 gene polymorphism and breast cancer. METHODS: The retrieval time of this study was from the establishment of the database to February 2021. The retrieval databases included CNKI, Wanfang, VIP and China Biomedical Database, PubMed, Embase, Web of Science, and the Cochrane Library. The retrieval objects were observational studies on the relationship between HLA-DRB1 gene polymorphism and breast cancer (including case--control studies, cross-sectional studies, and cohort studies). The language restrictions were English and Chinese. Two researchers independently extracted the data and assessed the quality of the included studies, and Stata 16.0 software was used for statistical analysis. RESULTS: This study will systematically evaluate the relationship between HLA-DRB1 gene polymorphism and breast cancer based on existing studies. CONCLUSION: This study will explore the early warning signal of breast cancer genetic susceptibility, and provide evidence-based medical evidence for clarifying the role of HLA-DRB1 gene polymorphism in breast cancer. OSF REGISTRATION NUMBER: DOI 10.17605/OSF.IO/847FQ.

Preoperative tumor biopsy results in more detected sentinel nodes than intraoperative biopsy in breast cancer patients.

BACKGROUND: Sentinel lymph node biopsy (SLNB) plays a vital role in breast cancer surgery, and the identified number of sentinel nodes determines its accuracy for representing the status of the axillae. There are two types of tumor biopsies in breast cancer: preoperative and intraoperative biopsies. We compared the effects of the two different biopsies on the results of SLNB. METHODS: Patients with clinical stages T1-3, N0 (cT1-3 N0) tumors were enrolled in this study. A total of 53% of patients received preoperative tumor biopsy, and 47% received intraoperative excisional biopsy. To identify the sentinel lymph nodes, patients received dual tracer injection. The number of SLNs detected and the false-negative rate were compared between groups. RESULTS: A total of 204 patients were enrolled, 108 received preoperative tumor biopsy, and 96 received intraoperative excisional biopsy. Among all the patients, 160 received axillary lymph node dissection (ALND) following SLNB. Preoperative tumor biopsy detected more SLNs than intraoperative biopsy (mean rank 113.87 vs. 90.9, p = 0.004). The false-negative rates in the preoperative and intraoperative tumor biopsy groups were 3% and 18%, respectively. CONCLUSIONS: Patients in the preoperative tumor biopsy group had more SLNs identified than intraoperative biopsy patients. The false-negative rate was also lower in the preoperative biopsy group.

Syndecan-4 is a Novel Therapeutic Target for Intervertebral Disc Degeneration via Suppressing JNK/p53 Pathway.

Syndecan-4 is a member of the polysaccharide syndecan family and plays a vital role in intervertebral disc development. Several studies have demonstrated the positive relationship between syndecan-4 expression and intervertebral disc degeneration. However, the detailed molecular mechanism by which syndecan-4 affects the degeneration of nucleus pulposus cells (NPCs) remains unclear. In this study, cell viability was determined by CCK-8 assay, mRNA level was determined by qPCR, and protein expression was determined by western blot. Molecular interaction was determined by chromatin immunoprecipitation assay. A rabbit intervertebral disc degeneration model was established to test for syndecan in vivo. We found that the morphology and viability of NPCs were not affected by the expression of syndecan-4 in the long term. While the NPC function were affected, which results in the degeneration of intervertebral disc. Syndecan-4 overexpression promoted the degeneration of NPCs. Syndecan-4 also activated the JNK signaling pathway and downstream p53 pathways, and promoted degeneration. Inhibition of the JNK pathway, which down-regulated p53 expression, alleviated the degeneration. In an in vivo study, syndecan-4 siRNA injection stopped the development of rabbit disc degeneration, and even created a reverse effect, in which JNK/p53 played a role. Syndecan-4 may be a novel therapeutic target for intervertebral disc degeneration via suppressing the JNK/p53 pathway.

Pilose antler peptide promotes osteoblast proliferation, differentiation and mineralization via the insulin signaling pathway.

Osteoporosis is a severe bone disease characterized by a decrease in the density and structure of bones, with high risks of fractures. Pilose antler peptide (PAP), extracted and purified from deer antlers, can promote regeneration and fracture healing, and strengthen sinews and bone. To determine whether PAP can promote osteoblast development and to elucidate the molecular mechanisms underlying its functions, the present study investigated the effects of PAP on osteoblast proliferation, differentiation and mineralization, and the role of the insulin signaling pathway using MTT assay, alkaline phosphatase activity assay, western blot analysis and reverse transcription-quantitative PCR. The present results suggested that PAP promoted osteoblast proliferation, differentiation and mineralization in vitro via the insulin signaling pathway. The effect of PAP on insulin signaling in osteoblasts may be mediated via the ERK pathway and partially by the PI3K/Akt pathway. The present results indicated that PAP could potentially be developed as an alternative treatment strategy for bone diseases related to diabetes characterized by insulin signaling impairment.

Expression of PD-1/PD-L1 in primary breast tumours and metastatic axillary lymph nodes and its correlation with clinicopathological parameters.

The aim of this study was to compare the expression of PD-1/PD-L1 in primary breast tumours to that in metastatic axillary lymph nodes and to determine the correlation between the PD-1/PD-L1 status and clinicopathologic characteristics. In total, 47 paired breast tumour and metastatic axillary lymph node samples were collected in this study. Immunohistochemical technology was used to determine the positivity or negativity of PD-1/PD-L1. Other patient information was retrieved from medical records. Significant differences in PD-L1 expression were observed between primary breast tumours and paired axillary lymph nodes. We also observed that the presence of PD-1/PD-L1 positivity in metastatic lymph nodes was significantly associated with poor prognostic features, such as a high Ki-67 index (p = 0.048), a high TNM stage (p = 0.012), a large number of metastatic lymph nodes (p = 0.002), and a high histology grade (p = 0.029). Since heterogeneity exists, it is necessary to determine the PD-L1 status in both the primary tumour and metastatic lymph nodes.

The effects of blended learning on knowledge, skills, and satisfaction in nursing students: A meta-analysis.

OBJECTIVE: The aim of this meta-analysis is to investigate the effects of blended learning on nursing students' knowledge, skills and satisfaction. METHODS: We searched EMBASE, PubMed, CINAHL, Cochrane Library for publications in English up to December 2018. Two researchers independently screened the literature and extracted the data. Meta-analysis was performed with Revman5.0 for the eligible studies. RESULTS: A total of 8 studies met the inclusion criteria of meta-analysis, including 574 nursing students. Compared with traditional teaching, blended learning could effectively improve nursing students' knowledge (SMD = 0.70, 95% CI [0.52, 0.87], P < 0.00001) and satisfaction (SMD = 0.72, 95% CI [0.08, 0.59], P = 0.01), and tended to improve the skills although without significant difference (SMD = 0.58, 95% CI [-0.17, 1.32], P = 0.13). CONCLUSIONS: Blended learning can effectively improve the knowledge and satisfaction of nursing students. Therefore, blended learning can be used as a teaching method in nursing education.

Secreted Phosphoprotein 1 Promotes the Development of Small Cell Lung Cancer Cells by Inhibiting Autophagy and Apoptosis.

This study aimed to investigate the expression of secreted phosphoprotein 1 (SPP1) on lung cancer cells and explore its underlying mechanism on autophagy and apoptosis which effect the development of lung cancer cells. GSE19804 related to lung cancer cells was screened from Gene Expression Omnibus (GEO) database, and we screened the 47 pairs of differential expressed mRNAs in lung cancer cells and adjacent tissues using microarray analysis. The expression of the core gene SPP1 was detected by qRT-PCR and western-blot. The transfection efficiency of lung cancer cells was detected by qRT-PCR and the expression of transfected group was tested by western-blot. Cell proliferation after transfection was tested by MTT assay and plate cloning experiment. The apoptosis rate of each transfection group was detected by flow cytometry. We use western-blot to test protein expression of autophagy-related proteins Beclin-1, LC3-I, LC3-II and p62 of each transfected group. Through analysis of GSE19804,the heat map showed SPP1 was the highest expressed in tumor tissues. qRT-PCR and western-blot detected SPP1 expression in lung cancer tissues was higher than that in normal adjacent tissues and was significantly increased in lung cancer cell lines. After transfection with pcDNA3.1-SPP1 (p-SPP1 group), siRNA1-SPP1 (siRNA1 group) and siRNA2-SPP1 (siRNA2 group), showed different expression of SPP1. Up-regulation of SPP1 enhanced cell viability and promoted tumor cell proliferation, while knockdown of SPP1 inhibited tumor cell proliferation. From the results of apoptosis rate, SPP1 inhibited the tumor cell apoptosis. However, in normal lung cell, SPP1 had no effect on cell proliferation and apoptosis. And to test autophagy-related proteins, we found that overexpression of SPP1 inhibited autophagy. High expression of SPP1 inhibited autophagy and apoptosis to promote the development of small cell lung cancer cells.

The role of TGF-ß1/Smad2/3 pathway in platelet-rich plasma in retarding intervertebral disc degeneration.

Recent studies have suggested that platelet-rich plasma (PRP) injections are an effective way to retard intervertebral disc degeneration, but the mechanism of action is unclear. Activated platelets release some growth factors, such as transforming growth factor-ß1 (TGF-ß1), which positively modulate the extracellular matrix of nucleus pulposus cells. The purpose of this study was to explore the mechanism underlying the PRP-mediated inhibition of intervertebral disc degeneration. In an in vitro study, we found that the proliferation of nucleus pulposus cells was greatly enhanced with 2.5% PRP treatment. The TGF-ß1 concentration was much higher after PRP treatment. PRP administration effectively increased the collagen II, aggrecan and sox-9 mRNA levels and decreased collagen X levels. However, Western blotting demonstrated that specifically inhibiting TGF-ß1 signalling could significantly prevent nucleus pulpous cellular expression of Smad2/3 and matrix protein. In a rabbit study, magnetic resonance imaging revealed significant recovery signal intensity in the intervertebral discs of the PRP injection group compared with the very low signal intensity in the control groups. Histologically, the PRP plus inhibitor injection group had significantly lower expression levels of Smad2/3 and collagen II than the PRP group. These results demonstrated that a high TGF-ß1 content in the platelets retarded disc degeneration in vitro and in vivo. Inhibiting the TGF-ß1/Smad2/3 pathway could prevent this recovery by inactivating Smad2/3 and down-regulating the extracellular matrix. Therefore, the TGF-ß1/Smad2/3 pathway might play a critical role in the ability of PRP to retard intervertebral disc degeneration.

TGF-ßl Suppresses Inflammation in Cell Therapy for Intervertebral Disc Degeneration.

Recent studies suggest that cell therapy may be an effective way to repair intervertebral disc degeneration. As a strong immune suppressor, TGF-ß1 has been shown to inhibit inflammation respond effectively. The objective of this study was to explore the effects of TGF-ß1 during bone marrow mesenchymal stem cells-based therapy for disc degeneration. In vitro assays demonstrated that co-culturing of nucleus pulposus cells with bone marrow mesenchymal stem cells resulted in significantly higher levels of TGF-ßl secretion. This increase inhibited IκB phosphorylation and NF-κB activation, detected by western blot analysis. Meanwhile, in a rabbit model, MRI analysis revealed significant recovery of signal intensity in the degenerative discs of rabbits receiving cells transplantation, than receiving cells treated with a TGF-ß1 inhibitor or saline. These findings indicated that enhanced TGF-ß1 production recovered the degeneration of intervertebral disc. And also immunohistochemical staining detected enhanced collagen II expression in the rabbits treated with cell transplantation. However, the NF-κB positive cells were significantly less than other two control groups. Thus, cell therapy promoted TGF-ß1 expression in nucleus pulposus, leading to anti-inflammatory effects via the inhibition of NF-κB, and the amelioration of disc degradation due to increased expression of collagen II and aggrecan in degenerative intervertebral disc.

The incidence of secondary vertebral fracture of vertebral augmentation techniques versus conservative treatment for painful osteoporotic vertebral fractures: a systematic review and meta-analysis.

BACKGROUND: Percutaneous vertebroplasty (PVP) and balloon kyphoplasty (BKP) are minimally invasive and effective vertebral augmentation techniques for managing osteoporotic vertebral compression fractures (OVCFs). Recent meta-analyses have compared the incidence of secondary vertebral fractures between patients treated with vertebral augmentation techniques or conservative treatment; however, the inclusions were not thorough and rigorous enough, and the effects of each technique on the incidence of secondary vertebral fractures remain unclear. PURPOSE: To perform an updated systematic review and meta-analysis of the studies with more rigorous inclusion criteria on the effects of vertebral augmentation techniques and conservative treatment for OVCF on the incidence of secondary vertebral fractures. MATERIAL AND METHODS: PubMed, MEDLINE, EMBASE, SpringerLink, Web of Science, and the Cochrane Library database were searched for relevant original articles comparing the incidence of secondary vertebral fractures between vertebral augmentation techniques and conservative treatment for patients with OVCFs. Randomized controlled trials (RCTs) and prospective non-randomized controlled trials (NRCTs) were identified. The methodological qualities of the studies were evaluated, relevant data were extracted and recorded, and an appropriate meta-analysis was conducted. RESULTS: A total of 13 articles were included. The pooled results from included studies showed no statistically significant differences in the incidence of secondary vertebral fractures between patients treated with vertebral augmentation techniques and conservative treatment. Subgroup analysis comparing different study designs, durations of symptoms, follow-up times, races of patients, and techniques were conducted, and no significant differences in the incidence of secondary fractures were identified (P > 0.05). No obvious publication bias was detected by either Begg's test (P = 0.360 > 0.05) or Egger's test (P = 0.373 > 0.05). CONCLUSION: Despite current thinking in the field that vertebral augmentation procedures may increase the incidence of secondary fractures, we found no differences in the incidence of secondary fractures between vertebral augmentation techniques and conservative treatment for patients with OVCFs.

Effect of occipitocervical fusion with screw-rod system for upper cervical spine tumor.

BACKGROUND: Craniospinal junction tumors are rare but severe lesions. Surgical stabilization has been established to be an ideal treatment for upper cervical tumor pathology. The purpose of this study was to evaluate the effect of a screw-rod system for occipitocervical fusion. METHODS: A total of 24 cases with C1 and C2 cervical tumor underwent occipitocervical fusion with Vertex screw-rod internal fixation from January 2005 to December 2012. Preoperative X-ray and MRI examinations were performed on all patients before the operation, after the operation, and during last follow-up. The JOA score was used to assess neurological function pre and postoperatively. RESULTS: All the patients were followed up for 6 to 42 months with an average of 24 months. The result of X-ray showed that bony fusion was successful in 18 patients at 3 months and 6 patients at 6 months of follow-ups. There was no deterioration of spinal cord injury. The JOA Scores of neurological function increased significantly. CONCLUSION: The screw-rod system offers strong fixation and good fusion for occipitocervical fusion. It is an effective and reliable method for reconstruction of upper cervical spine tumor.

The effects of platelet-rich plasma on the osteogenic induction of bone marrow mesenchymal stem cells.

Bone marrow mesenchymal stem cells (BMSCs) are multipotent stem cells. Finding methods to improve the osteogenic potential of these cells is a key factor in bone tissue engineering. Platelet-rich plasma (PRP) contains powerful growth factors that produce changes in a variety of cell types. The purpose of this study was to explore the effects of PRP on the osteogenic differentiation of BMSCs in vitro. Rabbit BMSCs were harvested and cultured in vitro in control media or in media enhanced with PRP. BMSCs began to attach 12-24 hours after seeding. A MTT assay demonstrated that PRP-induced BMSCs grew rapidly compared with the control group. The PRP group also showed strongly positive staining of alkaline phosphatase and mineralized nodules whereas the control group showed negative staining. However, the alkaline phosphatase activity and the mRNA level of the osteogenic markers (osteocalcin and osteopontin) remained higher in the PRP group. These results confirmed that PRP could enhance the proliferation of BMSCs and effectively promote the osteogenic differentiation of BMSCs in vitro.

Impact and clinical significance of pedicle length on spinal canal and intervertebral foramen area.

The aim of this study was to measure changes in the cross-sectional area of the spinal canal and the area of the intervertebral foramen for each pedicle segment before and after the pedicle extension using computer-simulated transpedicular osteotomy to provide a theoretical basis for clinical decompression in the lumbar spinal canal. Using spiral CT scanning of the original lumbar spine, a finite element model was established. The pedicle was cut and extended by 2 mm, 4 mm, 6 mm, and 8 mm for respective modeling. The changes in the area of each plane of the vertebral canal and the area of the intervertebral foramen were measured. With the gradual extension of the pedicle, the areas of the spinal canal and intervertebral foramen also significantly increased compared with those of the original lumbar spine (P<0.05). The extension of the pedicle using transpedicular osteotomy can significantly increase the cross-sectional area of the lumbar canal and the area of the intervertebral foramen. This finding provides a new theoretically practicable method for the clinical decompression of the lumbar spinal canal.