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Background: The early progression continuum of Alzheimer’s disease (AD) has been considered to advance through subjective cognitive decline (SCD), non-amnestic mild cognitive impairment (naMCI), and amnestic mild cognitive impairment (aMCI). Altered functional connectivity (FC) in the default mode network (DMN) is regarded as a hallmark of AD. Furthermore, the DMN can be divided into two subnetworks, the anterior and posterior subnetworks. However, little is known about distinct disruptive patterns in the subsystems of the DMN across the preclinical AD spectrum. This study investigated the connectivity patterns of anterior DMN (aDMN) and posterior DMN (pDMN) across the preclinical AD spectrum.Methods: Resting-state functional magnetic resonance imaging (rs-fMRI) was used to investigate the FC in the DMN subnetworks in 20 healthy controls (HC), eight SCD, 11 naMCI, and 28 aMCI patients. Moreover, a correlation analysis was used to examine associations between the altered connectivity of the DMN subnetworks and the neurocognitive performance.Results: Compared to the HC, SCD patients showed increased FC in the bilateral superior frontal gyrus (SFG), naMCI patients showed increased FC in the left inferior parietal lobule (IPL), and aMCI patients showed increased FC in the bilateral IPL in the aDMN; while SCD patients showed decreased FC in the precuneus, naMCI patients showed increased FC in the left middle temporal gyrus (MTG), and aMCI patients also showed increased FC in the right middle frontal gyrus (MFG) in the pDMN. Notably, the FC between the ventromedial prefrontal cortex (vmPFC) and the left MFG and the IPL in the aDMN was associated with episodic memory in the SCD and aMCI groups. Interestingly, the FC between the posterior cingulated cortex (PCC) and several regions in the pDMN was associated with other cognitive functions in the SCD and naMCI groups.Conclusions: This study demonstrates that the three preclinical stages of AD exhibit distinct FC alternations in the DMN subnetworks. Furthermore, the patient group data showed that the altered FC involves cognitive function. These findings can provide novel insights for tailored clinical intervention across the preclinical AD spectrum.

Background: The difficulty of assessment of neoadjuvant chemotherapeutic response preoperatively may hinder personalized-medicine strategies that depend on the results from pathological examination. Methods: A total of 191 patients with high-grade osteosarcoma (HOS) were enrolled retrospectively from November 2013 to November 2017 and received neoadjuvant chemotherapy (NCT). A cutoff time of November 2016 was used to divide the training set and validation set. All patients underwent diagnostic CTs before and after chemotherapy. By quantifying the tumor regions on the CT images before and after NCT, 540 delta-radiomic features were calculated. The interclass correlation coefficients for segmentations of inter/intra-observers and feature pair-wise correlation coefficients (Pearson) were used for robust feature selection. A delta-radiomics signature was constructed using the lasso algorithm based on the training set. Radiomics signatures built from single-phase CT were constructed for comparison purpose. A radiomics nomogram was then developed from the multivariate logistic regression model by combining independent clinical factors and the delta-radiomics signature. The prediction performance was assessed using area under the ROC curve (AUC), calibration curves and decision curve analysis (DCA). Results:The delta-radiomics signature showed higher AUC than single-CT based radiomics signatures in both training and validation cohorts. The delta-radiomics signature, consisting of 8 selected features, showed significant differences between the pathologic good response (pGR) (necrosis fraction ≥90%) group and the non-pGR (necrosis fraction < 90%) group (P < 0.0001, in both training and validation sets). The delta-radiomics nomogram, which consisted of the delta-radiomics signature and new pulmonary metastasis during chemotherapy showed good calibration and great discrimination capacity with AUC 0.871 (95% CI, 0.804 to 0.923) in the training cohort, and 0.843 (95% CI, 0.718 to 0.927) in the validation cohort. The DCA confirmed the clinical utility of the radiomics model. Conclusion:The delta-radiomics nomogram incorporating the radiomics signature and clinical factors in this study could be used for individualized pathologic response evaluation after chemotherapy preoperatively and help tailor appropriate chemotherapy and further treatment plans.

The mechanism by which osteosarcomas metastasize is elusive, and challenges remain regarding its treatment with modalities including immunotherapy. CXCL12 is deeply involved in the process of tumor metastasis and T-cell homing, which is driven by a chemokine gradient, but healthy bones are supposed to preferentially express CXCL12. Here, we show for the first time that osteosarcomas epigenetically downregulate CXCL12 expression via DNA methyltransferase 1 (DNMT1) and consequently acquire the ability to metastasize and to impair cytotoxic T-cell homing to the tumor site. Analysis of human osteosarcoma cases further revealed that CXCL12 expression strongly correlated with overall survival. Evaluations on fresh human chemotherapy-free osteosarcoma samples also showed a positive correlation between CXCL12 concentration and the number of intratumoral lymphocytes. Critically, treatment targeting DNMT1 in immunocompetent mouse models significantly elevated expression of CXCL12 in tumors, resulting in a robust immune response and consequently eradicating early lung metastases in addition to suppressing subcutaneous tumor growth. These antitumor effects were abrogated by CXCL12-CXCR4 blockade or CD8 T-cell depletion. Collectively, our data show that CXCL12 regulation plays a significant role in both tumor progression and immune response, and targeting CXCL12 is promising for therapeutics against osteosarcoma. Epigenetic regulation of CXCL12 controls metastasis and immune response in osteosarcoma, suggesting epigenetic therapies or therapies targeting CXCL12 have potential for therapeutic intervention in osteosarcoma. .

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Iodine has been known as an effective disinfectant with broad‐spectrum antimicrobial potency yet without drug resistance risk when used in clinic. However, the exploration of iodine for antibacterial therapy in orthopedics remains sparse due to its volatile nature and poor solubility. Herein, leveraging the superior absorption capability of metal–organic frameworks (MOFs) and their inherent photocatalytic properties, iodine‐loaded MOF surface is presented to realize responsive iodine release along with intracellular reactive oxygen species(ROS) oxidation under near‐infrared (NIR) exposure to achieve synergistic antibacterial effect. Iodine is successfully loaded using vapor deposition process onto zeolitic imidazolate framework‐8(ZIF‐8), which is immobilized onto micro arc oxidized titanium via a hydrothermal approach. The combination of NIR‐triggered iodine release and ZIF‐8 mediated ROS oxidative stress substantially augments the antibacterial efficacy of this approach both in vitro and in vivo. Furthermore, this composite coating also supported osteogenic differentiation of bone marrow stromal cells, as well as improved osseointegration of coated implants using an intramedullary rat model, suggesting improvement of antibacterial efficacy does not impair osteogenic potential of the implants. Altogether, immobilization of iodine via MOF on orthopedic implants with synergistic antibacterial effect can be a promising strategy to combat bacterial infections.

Objectives The aims of our study are (1) to explore the risk factors of mechanical failure (MF), (2) to figure out an index to evaluate this risk, and (3) to select an optimal reconstruction strategy to reduce this risk. Methods We retrospectively reviewed 104 patients from Dec. 2008 to Mar. 2016, undergone extensive knee curettages in our institution. Radiographs and post-operative interviews were used to classified cases of MF. Relative factors (age, tumor location, the invaded area, etc.) were also collected and analyzed by SPSS software. Results Thick subchondral bony layer (p = 0.006) and combined grafting of the cement and bone (p = 0.006) had lower risk of mechanical failure. Mechanical failure appeared to happen in the femur (p = 0.012) more easily. The ROC curve (AUC = 0.722) reveals that less post-operative bony layer (≤ 3.3 mm) is more likely to cause mechanical failure. The Kaplan-Meier survival curve showing increased survival in those patients after a combination grafting surgery (HR, 3.799; p = 0.006). Conclusion Based on our study results, combined grafting of the cement and bone reduced the risk of mechanical failure in the knee due to the thin subchondral bone layer (SCB), especially in the femur.

Precise timing of macrophage polarization plays a pivotal role in immunomodulation of tissue regeneration, yet most studies mainly focus on M2 macrophages for their anti‐inflammatory and regenerative effects while the essential proinflammatory role of the M1 phenotype on the early inflammation stage is largely underestimated. Herein, a superparamagnetic hydrogel capable of timely controlling macrophage polarization is constructed by grafting superparamagnetic nanoparticles on collagen nanofibers. The magnetic responsive hydrogel network enables efficient polarization of encapsulated macrophage to the M2 phenotype through the podosome/Rho/ROCK mechanical pathway in response to static magnetic field (MF) as needed. Taking advantage of remote accessibility of magnetic field together with the superparamagnetic hydrogels, a temporal engineered M1 to M2 transition course preserving the essential role of M1 at the early stage of tissue healing, as well as enhancing the prohealing effect of M2 at the middle/late stages is established via delayed MF switch. Such precise timing of macrophage polarization matching the regenerative process of injured tissue eventually leads to optimized immunomodulatory bone healing in vivo. Overall, this study offers a remotely time‐scheduled approach for macrophage polarization, which enables precise manipulation of inflammation progression during tissue healing.