AI's deep dive into complex pediatric inguinal hernia issues: a challenge to traditional guidelines?

OBJECTIVE

This study utilized ChatGPT, an artificial intelligence program based on large language models, to explore controversial issues in pediatric inguinal hernia surgery and compare its responses with the guidelines of the European Association of Pediatric Surgeons (EUPSA).

METHODS

Six contentious issues raised by EUPSA were submitted to ChatGPT 4.0 for analysis, for which two independent responses were generated for each issue. These generated answers were subsequently compared with systematic reviews and guidelines. To ensure content accuracy and reliability, a content analysis was conducted, and expert evaluations were solicited for validation. Content analysis evaluated the consistency or discrepancy between ChatGPT 4.0's responses and the guidelines. An expert scoring method assess the quality, reliability, and applicability of responses. The TF-IDF model tested the stability and consistency of the two responses.

RESULTS

The responses generated by ChatGPT 4.0 were mostly consistent with the guidelines. However, some differences and contradictions were noted. The average quality score was 3.33, reliability score was 2.75, and applicability score was 3.46 (out of 5). The average similarity between the two responses was 0.72 (out of 1), Content analysis and expert ratings yielded consistent conclusions, enhancing the credibility of our research.

CONCLUSION

ChatGPT can provide valuable responses to clinical questions, but it has limitations and requires further improvement. It is recommended to combine ChatGPT with other reliable data sources to improve clinical practice and decision-making.

An optimized nonlinear generalized predictive control for steam temperature in an ultra supercritical unit

The optimize control of the ultra supercritical (USC) unit has been a major concern in power industry. The intermediate point temperature process is a multi-variable system with strong nonlinearity, large scale and great delay, which greatly affects the safety and economy of the USC unit. Generally, it is difficult to realize effective control by using conventional methods. This paper presents a nonlinear generalized predictive control based on a composite weighted human learning optimization network (CWHLO-GPC) to improve the control performance of intermediate point temperature. Based on the characteristics of the onsite measurement data, the heuristic information is incorporated into the CWHLO network, and expressed by different local linear models. Then, global controller is elaborately constituted based on a scheduling program inferred from the network. Compared with classical generalized predictive control (GPC), the non-convex problem is effectively solved by introducing CWHLO models into the convex quadratic program (QP) routine of local linear GPC. Finally, detailed analysis on set point tracking and interference resisting via simulation is addressed to illustrate the efficiency of the proposed strategy.

[A semi-supervised network-based tissue-aware contrast enhancement method for CT images]

OBJECTIVE

To propose a tissue- aware contrast enhancement network (T- ACEnet) for CT image enhancement and validate its accuracy in CT image organ segmentation tasks.

METHODS

The original CT images were mapped to generate low dynamic grayscale images with lung and soft tissue window contrasts, and the supervised sub-network learned to recognize the optimal window width and level setting of the lung and abdominal soft tissues via the lung mask. The self-supervised sub-network then used the extreme value suppression loss function to preserve more organ edge structure information. The images generated by the T-ACEnet were fed into the segmentation network to segment multiple abdominal organs.

RESULTS

The images obtained by T-ACEnet were capable of providing more window setting information in a single image, which allowed the physicians to conduct preliminary screening of the lesions. Compared with the suboptimal methods, T-ACE images achieved improvements by 0.51, 0.26, 0.10, and 14.14 in SSIM, QABF, VIFF, and PSNR metrics, respectively, with a reduced MSE by an order of magnitude. When T-ACE images were used as input for segmentation networks, the organ segmentation accuracy could be effectively improved without changing the model as compared with the original CT images. All the 5 segmentation quantitative indices were improved, with the maximum improvement of 4.16%.

CONCLUSION

The T-ACEnet can perceptually improve the contrast of organ tissues and provide more comprehensive and continuous diagnostic information, and the T-ACE images generated using this method can significantly improve the performance of organ segmentation tasks.

Black phosphorus thermosensitive hydrogels loaded with bone marrow mesenchymal stem cell-derived exosomes synergistically promote bone tissue defect repair

The osteogenic function of mesenchymal stem cells (MSCs) is mainly attributed to the paracrine effect of extracellular vesicles. MSC-derived exosomes are interesting candidates as biopharmaceuticals for drug delivery and for the engineering of biologically functionalized materials, and have emerged as cell-free regenerative medicine in recent years. In this study, bone marrow mesenchymal stem cell (BMSC)-derived exosomes were loaded with photothermal material layered black phosphorus (BP) modified poly(N-isopropylacrylamide) (PNIPAAm) thermosensitive hydrogels to explore their effects on bone defect repair. In vitro, it was confirmed that the local high heat of nano-BP irradiated using a near-infrared (NIR) laser could trigger the reversible cascade reaction of hydrogels, and that the mechanical contraction of hydrogels led to the controllable release of a large number of exosomes along with the release of water molecules. Furthermore, in vitro investigations demonstrated that BP hydrogels loaded with BMSC-derived exosomes had favourable biocompatibility and could promote the proliferation and osteogenic differentiation of MSCs. Experiments conducted in vivo confirmed that this system significantly promoted bone regeneration. Therefore, the results of our study indicated that the nanoplatform based on BP thermosensitive hydrogels could provide a new clinical treatment strategy for controlled release and on-demand drug delivery, while the cell-free system composed of BMSC-derived exosomes had great application potential in bone tissue repair with the synergism of BP.

[A semi-supervised material quantitative intelligent imaging algorithm for spectral CT based on prior information perception learning]

OBJECTIVE

To propose a semi-supervised material quantitative intelligent imaging algorithm based on prior information perception learning (SLMD-Net) to improve the quality and precision of spectral CT imaging.

METHODS

The algorithm includes a supervised and a self- supervised submodule. In the supervised submodule, the mapping relationship between low and high signal-to-noise ratio (SNR) data was constructed through mean square error loss function learning based on a small labeled dataset. In the self- supervised sub-module, an image recovery model was utilized to construct the loss function incorporating the prior information from a large unlabeled low SNR basic material image dataset, and the total variation (TV) model was used to to characterize the prior information of the images. The two submodules were combined to form the SLMD-Net method, and pre-clinical simulation data were used to validate the feasibility and effectiveness of the algorithm.

RESULTS

Compared with the traditional model-driven quantitative imaging methods (FBP-DI, PWLS-PCG, and E3DTV), data-driven supervised-learning-based quantitative imaging methods (SUMD-Net and BFCNN), a material quantitative imaging method based on unsupervised learning (UNTV-Net) and semi-supervised learning-based cycle consistent generative adversarial network (Semi-CycleGAN), the proposed SLMD-Net method had better performance in both visual and quantitative assessments. For quantitative imaging of water and bone materials, the SLMD-Net method had the highest PSNR index (31.82 and 29.06), the highest FSIM index (0.95 and 0.90), and the lowest RMSE index (0.03 and 0.02), respectively) and achieved significantly higher image quality scores than the other 7 material decomposition methods (P < 0.05). The material quantitative imaging performance of SLMD-Net was close to that of the supervised network SUMD-Net trained with labeled data with a doubled size.

CONCLUSIONS

A small labeled dataset and a large unlabeled low SNR material image dataset can be fully used to suppress noise amplification and artifacts in basic material decomposition in spectral CT and reduce the dependence on labeled data-driven network, which considers more realistic scenario in clinics.

Prediction of knee pain improvement over two years for knee osteoarthritis using a dynamic nomogram based on MRI-derived radiomics: a proof-of-concept study

OBJECTIVES

To develop and validate a nomogram to detect improved knee pain in osteoarthritis (OA) by integrating magnetic resonance imaging (MRI) radiomics signature of subchondral bone and clinical characteristics.

METHODS

Participants were selected from the Vitamin D Effects on Osteoarthritis (VIDEO) study. The primary outcome was 20% improvement of knee pain score over 2 years in participants administrated either vitamin D or placebo. Radiomics features of subchondral bone and clinical characteristics from 216 participants were extracted and analyzed. The participants were randomly split into the training and validation cohorts at a ratio of 8:2. Least absolute shrinkage and selection operator (LASSO) regression was used to select features and generate radiomics signatures. The optimal radiomics signature and clinical indicators were fitted into a nomogram using multivariable logistic regression model.

RESULTS

The nomogram showed favorable discrimination performance [AUC_training, 0.79 (95% CI: 0.72-0.79), AUC_validation, 0.83 (95% CI: 0.70-0.96)] as well as a good calibration. Additional contributing value of fusion radiomics signature to the nomogram was statistically significant (NRI, 0.23; IDI, 0.14, P < 0.001 in training cohort and NRI, 0.29; IDI, 0.18, P < 0.05 in validating cohort). Decision curve analysis confirmed the clinical usefulness of nomogram.

CONCLUSION

The radiomics-based nomogram comprising the MR radiomics signature and clinical variables achieves a favorable predictive efficacy and accuracy in differentiating improvement in knee pain among OA patients. This proof-of-concept study provides a promising way to predict clinically meaningful outcomes.

[Association analysis between genetic variants of matrix metalloproteinase enzyme 2 gene and the blood pressure of children and adolescents]

Objective: To explore the association between genetic variants of matrix metalloproteinase enzyme 2 (MMP2) gene and the blood pressure of children and adolescents. Methods: This cross-sectional study was performed in 2016 and included 4 155 children and adolescents in the urban area of Guangzhou. Physical examinations (including body height, weight, and blood pressure), questionnaires (including general characteristics, physical exercise, parental educational level, household income, etc.), and blood sampling were performed. Multivariable linear regression models were used to investigate the associations of MMP2 genetic variations (rs243865, rs7201) and the genetic risk score (GRS) level with standardized blood pressure. Mediating effect of standardized body mass index (BMI) was further assessed by process analysis in the association between GRS level and blood pressure, and potential additive interaction between physical activity and GRS level was analyzed using the product term in the regression model. Results: A total of 4 155 primary and secondary schoolchildren were finally included in the analysis, consisting of 1 401 (33.7%) second grade pupils of primary school, 1 422 (34.2%) first grade pupils of middle school, and 1 332 (32.1%) first-grade students of senior high school. After adjusting for age, sex, parental educational level, and family income, as compared to the rs243865 TT genotype, the CC/CT genotype increased diastolic blood pressure (DBP) by 0.461 standard deviations (SD) (β for dominant model=0.461, 95%CI 0.199-0.723). When compared to the rs7201 CC genotype, the AA/AC genotype showed 0.147 SD higher systolic blood pressure (SBP) (β for recessive model=0.147, 95%CI 0.014-0.279) and 0.171 SD increased DBP (β for recessive model=0.171, 95%CI 0.039-0.304). For each increment of GRS level, SBP and DBP increased by 0.151 SD (β for dominant model=0.151, 95%CI 0.029-0.272) and 0.242 SD (β=0.242, 95%CI 0.120-0.363), respectively. The mediating effect of BMI accounted for 28.3% and 12.6% of the total effect of GRS on SBP and DBP, respectively. After controlling BMI, the direct effect of GRS on DBP remained statistically significant (P<0.001). The insufficient moderate-to-vigorous physical activity (<0.5 h/d) showed a significant interaction with GRS on SBP under additive scale (β for interaction=0.518, 95%CI 0.088-0.949, P=0.018). Conclusions: rs243865 and rs7201 variants in MMP2 gene are associated with the elevated blood pressure of children and adolescents. Obesity may yield a mediation role in the associations, while insufficient physical activity may have a positively additive interaction with MMP2 genetic variants.

Pyroptosis-related gene-based prognostic signature for predicting the overall survival of oral squamous cell carcinoma patients

Purpose

Oral squamous cell carcinoma (OSCC) is the most common oral cancer worldwide. Pyroptosis is a type of programmed cell death mediated by caspase, accompanied by an inflammatory response, and plays an important role in cancer progression. The purpose of this study was to explore and identify potential biomarkers and further elucidate the potential role of cell pyroptosis in OSCC.

Methods

We regarded the samples from The Cancer Genome Atlas database as a training dataset, screened differentially expressed genes (DEGs), and further screened out OSCC phenotypic characteristic genes by using weighted gene co-expression network analysis. The analysis of 42 known pyroptosis-related genes showed that Psuch genes were widely expressed, mutated, and methylated in OSCC samples.

Results

Through correlation analysis, we identified our OSCC pyroptosis-related DEGs. To further evaluate the prognostic value of pyroptosis-related regulators, we constructed a seven gene-based prognostic signature using Cox univariate analysis and least absolute shrinkage and selection operator Cox regression analysis. Meanwhile, we found that patients in the low-risk group had higher immune infiltration. Moreover, our results also indicated significant differences in sensitivity to cisplatin and gefitinib between the high-risk and low-risk groups.

Conclusion

Our study successfully constructed the pyroptosis-related prognostic signature, which might play a potential prediction role in OSCC prognosis. Our findings also suggested that pyroptosis-related regulators might be novel biomarkers for tumor diagnosis and treatment in OSCC.

[Time-series analysis on the relationship between ambient PM2.5 and daily outpatient visits due to allergic conjunctivitis among children in Shenzhen]

Objective: To explore the short-term effects of ambient PM_2.5 on the outpatient visits of allergic conjunctivitis among children in Shenzhen. Methods: It was a ecological study. Data on daily visits including date of visit, sex and age from children with allergic conjunctivitis were collected from Shenzhen Eye Hospital and Shenzhen Children's Hospital in 2018. Related data on air pollution (PM_2.5, PM₁₀, SO₂, NO₂, CO and O₃) and meteorology (atmospheric pressure, temperature and relative humidity) were also collected. Pearson correlation analysis was used for normal distribution data and Spearman rank correlation analysis was used for non-normal distribution data. Generalized additive model was used to estimate the impact of PM_2.5 pollution on allergic conjunctivitis outpatients and the lagging effects. Results: In 2018, there were 16 133 allergic conjunctivitis outpatients in the two hospitals. The maximum age was 18 years and the minimum age was 2 months. Males accounted for 49.3%. The daily average concentration of PM_2.5 was 22 (15, 31) μg/m³. Changes of the concentration of PM_2.5 had a positive correlation with the amount of allergic conjunctivitis visits, and the Spearman correlation coefficient was 0.150 (P=0.004). The single pollutant model showed that the strongest effect appeared at 3 days (RR=1.111， 95%CI:1.071-1.152). A 10 μg/m³ increase of PM_2.5 would result in an excessive number of allergic conjunctivitis outpatients as much as 11.112% (95%CI：7.011%-15.212%). In the multiple air pollutants models, after the introduction of NO₂, O₃ and CO, the concentration of PM_2.5 showed an enhanced effect on the number of hospital visits due to allergic conjunctivitis on the same day, and the difference was statistically significant (P<0.05). Conclusion: Changes of the concentration of PM_{2.5 h}ad a positive correlation with daily outpatient visits of allergic conjunctivitis among children in Shenzhen. (Chin J Ophthalmol, 2020, 56: 608-614).

MicroRNA-374b accelerates the development of lung cancer through downregulating PTEN expression via activating PI3K/Akt pathway

OBJECTIVE

To elucidate whether microRNA-374b could participate in the development of lung cancer (LC) through downregulating PTEN (gene of phosphate and tensin homolog deleted on chromosome ten) expression via activating PI3K/Akt pathway.

PATIENTS AND METHODS

Expression levels of microRNA-374b and PTEN in LC tissues and adjacent normal tissues were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Moreover, the expression level of microRNA-374b in LC cell lines was detected as well. The microRNA-374b inhibitor was constructed and transfected to downregulate microRNA-374b expression in A549 and H358 cells. The regulatory effects of microRNA-374b on migratory and proliferative capacities of LC cells were explored by wound healing and cell counting kit-8 (CCK-8) assay, respectively. After co-transfection of microRNA-374b inhibitor and si-PTEN in LC cells, expression levels of PTEN/PI3K/Akt were determined by qRT-PCR and Western blot.

RESULTS

QRT-PCR results showed that microRNA-374b expression was higher, while PTEN expression was lower in LC tissues than adjacent tissues. Identically, microRNA-374b was also highly expressed in LC cell lines. PTEN expression was negatively correlated with microRNA-374b expression in LC. The downregulation of microRNA-374b in A549 and H358 cells inhibited their migratory and proliferative potentials. Subsequently, we verified that microRNA-374b could bind to PTEN through dual-luciferase reporter gene assay. MicroRNA-374b could inhibit PTEN expression and activate the PI3K/Akt pathway. Furthermore, PTEN knockdown enhanced migratory and proliferative abilities of LC cells, which were attenuated by co-transfection of microRNA-374b inhibitor.

CONCLUSIONS

MicroRNA-374b promotes the development of LC by downregulating PTEN expression through activating PI3K/Akt pathway.

1144 Actigraphy-defined Sleep And Neurocognitive Decline In Middle-age Hispanic/Latino Adults

Introduction

Few studies have evaluated objective sleep measures and longitudinal neurocognitive decline, particularly in middle-age or Hispanic/Latino adults. We evaluated prospective associations between actigraphy-defined sleep and 7-year neurocognitive change among Hispanic/Latino adults. We hypothesized that sleep duration would be associated with neurocognitive decline.

Methods

We analyzed data from 1,036 adults 45-64 years of age from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), a multi-center prospective cohort study of diverse community-dwelling Hispanic/Latino adults. At Visit 1 (2008-2011), participants underwent neurocognitive assessments, 7-days of actigraphy, home sleep testing, and sleep questionnaires (including the Insomnia Severity Index). Seven years later, participants repeated neurocognitive assessments. The neurocognitive battery included the Six-Item Screener, Brief Spanish-English Verbal Learning Test, phonemic word fluency test, and Digit Symbol Subtest. Survey linear regression was used to evaluate prospective associations between actigraphy-defined or self-reported sleep variables and neurocognitive change. Final models adjusted for objectively-defined variables (age, body-mass index, Field Center, and time between neurocognitive assessments), and self-reported variables (sex, education, Hispanic/Latino background, alcohol consumption, physical activity, heart failure, cerebrovascular events, depression and anxiety symptoms, and antidepressant use).

Results

At Visit 1, the sample was 55% female and mean age was 54.9±2.2 years. The mean sleep duration was 402.6±27.6 minutes, mean sleep-onset latency was 11.3±9.7 minutes, mean number of days with naps of ≥ 15 minutes duration was 1.1±0.7, and mean sleep-time per nap was 51±14.1 minutes. Increased sleep-onset latency was associated with 7-year declines in global neurocognitive function (β=-0.0026, p&lt;0.01), verbal learning (β=-0.0028, p&lt;0.001) and verbal memory (β=-0.036, p&lt;0.05). Increased sleep-time per nap predicted better verbal memory (β=0.0038, p&lt;0.05). In contrast, sleep duration, sleep fragmentation, and self-reported sleep measures were not associated with neurocognitive change.

Conclusion

Among middle-age adults, sleep-onset latency and nap duration were associated with neurocognitive change. These findings may serve as targets for intervention of neurocognitive decline.

Support

This work is supported by the National Institute on Aging: R01AG048642, RF1AG054548, R01AG061022, R21AG056952, and R21HL140437 (AR).

Over-expression of both VEGF-C and Twist predicts poor prognosis in human breast cancer

BACKGROUND

Angiogenesis is an indispensable step in the growth and invasiveness of breast cancers involving a series of exquisite molecular steps. Pro-angiogenic factors, including vascular endothelial growth factor (VEGF), have been recognized as pivotal therapeutic targets in the treatment of breast cancer. More recently, a highly conserved transcription factor Twist has been reported to be involved in tumor angiogenesis and metastasis.

METHODS

The expression of VEGF-C and Twist was immunohistochemically determined in tissue samples of primary tumors from 408 patients undergoing curative surgical resection for breast cancer. The correlations of VEGF-C and Twist expressions with clinicopathologic parameters as well as survival outcomes were evaluated.

RESULTS

Of the 408 patients evaluated, approximately 70% had high expression of VEGF-C which was significantly associated with advanced tumor stages (P = 0.019). Similarly, VEGF-C expression was associated with the proliferation index Ki67, N3 lymph node metastasis, and D2-40-positive lymphatic vessel invasion (LVI) in a univariate analysis. Furthermore, patients with high expressions of VEGF-C and Twist (V + T+) had significantly increased lymph node metastasis, higher clinical stage, and worse disease-free survival, DFS (P = 0.001) and overall survival, OS (P = 0.011).

CONCLUSIONS

Our results suggested that co-expression of VEGF-C and Twist was associated with larger tumor size, higher numbers of lymph node involvement, D2-40-positive LVI, higher risk of distant metastasis, and worse DFS or OS in breast cancer patients.

Early loading of splinted implants in posterior mandible: Three-year results of a prospective multicenter study

OBJECTIVE

To evaluate the clinical outcomes of an early loading protocol of splinted implants with a fluoride-modified nanostructure surface and a tapered apex design for the therapy of posterior partial edentulism of mandible.

MATERIALS AND METHODS

One hundred and seven implants were placed in the mandible of 45 subjects at three centres in China. A minimum of two and a maximum of three implants were placed in an edentulous region using a one-stage protocol. Each subject received a screw-retained, splinted and fixed permanent prosthesis 6-8 weeks after surgery. Marginal bone level (MBL) change, implant survival and soft tissue health were assessed at 6, 12, 24 and 36 months after loading. A total of 92 implants from 40 subjects were recalled and investigated in this clinical trial.

RESULTS

After three-year loading, the survival rate of implant was 100%. On a subject level, there was a mean (±SD) marginal bone gain of 0.23 ± 0.48 mm at 36-month recall and the change in MBL was statistically significant (p = .00061) compared with time of loading. On an implant level, the change in MBL was statistically significant (p = .03914, p = .01494, p = .00000) at 12, 24 and 36 months of loading compared with time of loading.

CONCLUSION

Three-year data indicate that early loading protocol of splinted implants with a fluoride-modified nanostructure surface and a tapered apex design is feasible and safe for the therapy of partial edentulism in posterior mandible, which may contribute to bone gain when the suitable occlusal load and oral hygiene maintenance are kept.

Functionalization of Silk Fibroin Electrospun Scaffolds via BMSC Affinity Peptide Grafting through Oxidative Self-Polymerization of Dopamine for Bone Regeneration

Electrospun scaffolds have been broadly studied to enhance bone regeneration because of the ability to simulate the structure and biological functions of the extracellular matrix. Polydopamine (PDA) is used to coat various surfaces at a slightly basic pH (8-8.5) and spontaneously reacts with nucleophilic functional groups. It is suitable for surface modifications of scaffolds correlated with bone formation. E7 is a newly discovered peptide with specific affinity for bone marrow mesenchymal stem cells (BMSCs). It can be useful for recruiting stem cells. Here, electrospun silk fibroin (SF) scaffolds were fabricated, and PDA was used for surface modification followed by grafting E7 (SF-PDA-E7). These composite SF-PDA-E7 electrospun scaffolds improved hydrophilicity, facilitated cell proliferation and adhesion, and boosted the osteogenic differentiation of BMSCs by creating osteoinduction conditions under the synergistic effects of PDA and E7. Moreover, the scaffolds showed high efficiency for recruiting BMSCs induced by E7 both in vitro and in vivo, which was associated with the SDF-1α/CXCR4 axis and the p38, extracellular signal-related kinase, and Akt signal transduction pathways. These functionalized electrospun scaffolds promoted regeneration of bone in the rat calvarial bone defect model. In general, this study verified that PDA could be a simple and efficient method for surface modification, and E7-grafted PDA-modified SF electrospun scaffolds were suitable for bone tissue engineering.

Enhanced bone regeneration of the silk fibroin electrospun scaffolds through the modification of the graphene oxide functionalized by BMP-2 peptide

Introduction

Bone tissue engineering has become one of the most effective methods to treat bone defects. Silk fibroin (SF) is a natural protein with no physiological activities, which has features such as good biocompatibility and easy processing and causes minimal inflammatory reactions in the body. Scaffolds prepared by electrospinning SF can be used in bone tissue regeneration and repair. Graphene oxide (GO) is rich in functional groups, has good biocompatibility, and promotes osteogenic differentiation of stem cells, while bone morphogenetic protein-2 (BMP-2) polypeptide has an advantage in promoting osteogenesis induction. In this study, we attempted to graft BMP-2 polypeptide onto GO and then bonded the functionalized GO onto SF electrospun scaffolds through electrostatic interactions. The main purpose of this study was to further improve the biocompatibility of SF electrospun scaffolds, which could promote the osteogenic differentiation of bone marrow mesenchymal stem cells and the repair of bone tissue defects.

Materials and methods

The successful synthesis of GO and functionalized GO was confirmed by transmission electron microscope, X-ray photoelectron spectroscopy, and thermogravimetric analysis. Scanning electron microscopy, atomic force microscopy, mechanical test, and degradation experiment confirmed the preparation of SF electrospun scaffolds and the immobilization of GO on the fibers. In vitro experiment was used to verify the biocompatibility of the composite scaffolds, and in vivo experiment was used to prove the repairing ability of the composite scaffolds for bone defects.

Results

We successfully fabricated the composite scaffolds, which enhanced biocompatibility, not only promoting cell adhesion and proliferation but also greatly enhancing in vitro osteogenic differentiation of bone marrow stromal cells using either an osteogenic or non-osteogenic medium. Furthermore, transplantation of the composite scaffolds significantly promoted in vivo bone formation in critical-sized calvarial bone defects.

Conclusion

These findings suggested that the incorporation of BMP-2 polypeptide-functionalized GO into chitosan-coated SF electrospun scaffolds was a viable strategy for fabricating excellent scaffolds that enhance the regeneration of bone defects.

Time-Phase Sequential Utilization of Adipose-Derived Mesenchymal Stem Cells on Mesoporous Bioactive Glass for Restoration of Critical Size Bone Defects

The effective transportation of oxygen, nutrients, and metabolic wastes through new blood vessel networks is key to the survival of engineered constructs in large bone defects. Adipose-derived mesenchymal stem cells (ADSCs), which are regarded as excellent candidates for both bone and blood vessel engineering, are the preferred option for the restoration of massive bone defects. Therefore, we propose to induce ADSCs into osteogenic and endothelial cells differently. A modified hierarchical mesoporous bioactive glass (MBG) scaffold with an enhanced compressive strength was constructed and prevascularized by seeding with endothelial-induced ADSCs (EI-ADSCs). The prevascularized scaffolds were combined with osteogenically induced ADSCs (OI-ADSCs) to repair critical-size bone defects. To validate the angiogenesis of the prevascularized MBG scaffolds in vivo, green fluorescent protein (GFP) was used to label EI-ADSCs. The labeled EI-ADSCs were demonstrated to survive and participate in vascularization at day 7 after subcutaneous implantation in nude mice by double immunofluorescence staining of CD31 and GFP. Regarding the restoration of critical size bone defects, early angiogenesis of rat femur plug defects was evaluated by perfusion of Microfil after 3 weeks. Compared to nonvascularized MBG carrying OI-ADSCs (MBG/OI-ADSCs) and non-cell-seeded MBG scaffolds, the prevascularized MBG carrying OI-ADSCs (Pv-MBG/OI-ADSCs) showed enhanced angiogenesis on the surface and interior. Through dynamic bone formation analysis with sequential fluorescent labeling and Van Gieson's picro-fuchsin staining, we found that the Pv-MBG/OI-ADSCs exhibited the highest mineral deposition rate after surgery, which may be contributed by rapid vascular anastomosis facilitating increased survival of the seeded OI-ADSCs and by the recruitment function for bone mesenchymal stem cells. Therefore, the strategy of time-phase sequential utilization of ADSCs on MBG scaffolds is a practical design for the repair of massive bone defects.

PLGA film/Titanium nanotubues as a sustained growth factor releasing system for dental implants

Ti-based implants sometimes fail to integrate with surrounding bone tissue due to insufficiency of new bone formation and surface bonding. To overcome this problem, this research focused on establishing a sustained bone growth factor delivery system by applying anodized TiO2 nanotube arrays and PLGA film on the titanium implant surface. TiO2 nanotube arrays were made by anodic oxidation method, and were then filled with rhBMP2 by vacuum freeze-drying. Next, PLGA was deposition on the surface of this material. The designed system was characterized, pharmacokinetic release rate of rhBMP2 was determined. Adhesion, proliferation, and differentiation activity of osteoblasts cultured on the new surfaces and traditional titanium surfaced were compared. SEM showed that a surface of TiO2 nanotube arrays were successfully generated. PLGA membranes of 50 nm, 250 nm, 800 nm thickness were successfully deposited on the surfaces of TiO2 nanotube layers by using 1%, 3%, 10% PLGA solutions. PLGA film of 250 nm thickness showed ideally controlled release of rhBMP2, lasting for 4 weeks. Furthermore, 250 nm thickness PLGA film improved osteoblast adhesion, proliferation, and levels of alkaline phosphatase. In conclusion, the PLGA film / TiO2 nanotube growth factor delivery system can effectively sustain the release of rhBMP-2, and promote proliferation and differentiation of MC3T3-E1 osteoblasts.

Appropriate dose of Lactobacillus buchneri supplement improves intestinal microbiota and prevents diarrhoea in weaning Rex rabbits

This study examined the effects on intestinal microbiota and diarrhoea of Lactobacillus buchneri supplementation to the diet of weaning Rex rabbits. To this end, rabbits were treated with L. buchneri at two different doses (LC: 104 cfu/g diet and HC: 105 cfu/g diet) for 4 weeks. PCR-DGGE was used to determine the diversity of the intestinal microbiota, while real-time PCR permitted the detection of individual bacterial species. ELISA and real-time PCR allowed the identification of numerous cytokines in the intestinal tissues. Zonula occludens-1, polymeric immunoglobulin receptor and immunoglobulin A genes were examined to evaluate intestinal barriers. Results showed that the biodiversity of the intestinal microbiota of weaning Rex rabbits improved in the whole tract of the treated groups. The abundance of most detected bacterial species was highly increased in the duodenum, jejunum and ileum after L. buchneri administration. The species abundance in the HC group was more increased than in the LC group when compared to the control. Although the abundance of Enterobacteriaceae exhibited a different pattern, Escherichia coli was inhibited in all treatment groups. Toll-like receptor (TLR)2 and TLR4 genes were down-regulated in all intestinal tissues as the microbiota changed. In the LC group, the secretion of the inflammatory cytokine tumour necrosis factor-α was reduced, the gene expression of the anti-inflammatory cytokine interleukin (IL)-4 was up-regulated and the expression of intestinal-barrier-related genes was enhanced. Conversely, IL-4 expression was increased and the expression of other tested genes did not change in the HC group. The beneficial effects of LC were greater than those of HC or the control in terms of improving the daily weight gain and survival rate of weaning Rex rabbits and reducing their diarrhoea rate. Therefore, 104 cfu/g L. buchneri treatment improved the microbiota of weaning Rex rabbits and prevented diarrhoea in these animals.

Gene expression profiles for a prognostic immunoscore in gastric cancer

Background

Increasing evidence has indicated an association between immune infiltration in gastric cancer and clinical outcome. However, reliable prognostic signatures, based on systematic assessments of the immune landscape inferred from bulk tumour transcriptomes, have not been established. The aim was to develop an immune signature, based on the cellular composition of the immune infiltrate inferred from bulk tumour transcriptomes, to improve the prognostic predictions of gastric cancer.

Methods

Twenty‐two types of immune cell fraction were estimated based on large public gastric cancer cohorts from the Gene Expression Omnibus using CIBERSORT. An immunoscore based on the fraction of immune cell types was then constructed using a least absolute shrinkage and selection operator (LASSO) Cox regression model.

Results

Using the LASSO model, an immunoscore was established consisting of 11 types of immune cell fraction. In the training cohort (490 patients), significant differences were found between high‐ and low‐immunoscore groups in overall survival across and within subpopulations with an identical TNM stage. Multivariable analysis revealed that the immunoscore was an independent prognostic factor (hazard ratio 1·92, 95 per cent c.i. 1·54 to 2·40). The prognostic value of the immunoscore was also confirmed in the validation (210) and entire (700) cohorts.

Conclusion

The proposed immunoscore represents a promising signature for estimating overall survival in patients with gastric cancer.

Immunoscore predicts prognosis

Alendronate delivery on amino modified mesoporous bioactive glass scaffolds to enhance bone regeneration in osteoporosis rats

The regeneration capacity of osteoporotic bones is generally lower than that of normal bones. Nowadays, alendronate (AL) are orally administrated for osteoporosis due to the inhibition of bone resorption. However, systemic administration of AL is characterized by extremely low bioavailability and high toxicity. In this study, the amino-modified mesoporous bioactive glass scaffolds (N-MBGS) were fabricated by a simple powder processing technique as a novel drug-delivery system for AL. The effects of AL on the osteogenic differentiation of bone mesenchymal stem cells derived from ovariectomized rats (rBMSCs-OVX) were first estimated. The loading efficiency and release kinetics of AL on N-MBGS were investigated in vitro and the osteogenesis of AL-loaded N-MBGS in rat calvarial defect model was detected by micro-CT measurements and the histological assay. Our results revealed that proper concentration of AL significantly promoted osteogenic differentiation of rBMSCs-OVX. The amount and delivery rate of AL were greatly improved through amino modification. Additionally, scaffolds with AL showed better bone formation in vivo, especially for the N-MBGS group. Our results suggest that the novel amino-modified MBGS are promising drug-delivery system for osteoporotic bone defect repairing or regeneration. The experimental schematic of the novel amino-modified MBGS as a promising drug-delivery system for osteoporotic bone regeneration.

Fabrication of large-pore mesoporous Ca-Si-based bioceramics for bone regeneration

Our previous study revealed that mesoporous Ca-Si-based materials exhibited excellent osteoconduction because dissolved ions could form a layer of hydroxycarbonate apatite on the surface of the materials. However, the biological mechanisms underlying bone regeneration were largely unknown. The main aim of this study was to evaluate the osteogenic ability of large-pore mesoporous Ca-Si-based bioceramics (LPMSCs) by alkaline phosphatase assay, real-time PCR analysis, von Kossa, and alizarin red assay. Compared with large-pore mesoporous silica (LPMS), LPMSCs had a better effect on the osteogenic differentiation of dental pulp cells. LPMSC-2 and LPMSC-3 with higher calcium possessed better osteogenic abilities than LPMSC-1, which may be related to the calcium-sensing receptor pathway. Furthermore, the loading capacity for recombinant human platelet-derived growth factor-BB was satisfactory in LPMSCs. In vivo, the areas of new bone formation in the calvarial defect repair were increased in the LPMSC-2 and LPMSC-3 groups compared with the LPMSC-1 and LPMS groups. We concluded that LPMSC-2 and LPMSC-3 possessed both excellent osteogenic abilities and satisfactory loading capacities, which may be attributed to their moderate Ca/Si molar ratio. Therefore, LPMSCs with moderate Ca/Si molar ratio might be potential alterative grafts for craniomaxillofacial bone regeneration.

The osteoimmunomodulatory properties of MBG scaffold coated with amino functional groups

Mesoporous bioactive glass (MBG) is a good scaffold for bone regeneration. In this study, amino functionalized MBG (N-MBG) was used as a model scaffold to examine the effect of the scaffold to bone marrow stromal cells (BMSCs) and macrophages. The MTT results revealed that the proliferation of BMSCs from ovariectomized rabbits was enhanced by N-MBG. Compared to the control group, the expression of osteogenic genes was significantly enhanced by N-MBG, which was related to CaSR pathway. Meanwhile, the anti-inflammatory cytokines (interleukin-10 and arginase-1) were also upregulated by N-MBG stimulation compared with MBG. Furthermore, the amino functionalization of MBG resulted in an increase in the pH value of the material extract. Interestingly, the formation of TRAP⁺ multinuclear cells was inhibited by the slightly alkaline extract to a certain extent, which reasonably explained the increase in TRAP⁺ multinuclear cells after adjusting the pH value of N-MBG extract. In vivo, the areas of new bone formation in the maxillary sinus floor elevation were increased in the N-MBG/BMSCs group with less TRAP⁺ multinuclear cells compared with the MBG/BMSCs group. These findings provided valuable insight that the osteogenic ability of MBG scaffold could be enhanced by amino functionalization due to coordinate BMSCs and macrophages differentiation.

The response of human osteoblasts, epithelial cells, fibroblasts, macrophages and oral bacteria to nanostructured titanium surfaces: a systematic study

Nanotopography modification is a major focus of interest in current titanium surface design; however, the influence of the nanostructured surface on human cell/bacterium behavior has rarely been systematically evaluated. In this study, a homogeneous nanofiber structure was prepared on a titanium surface (Nano) by alkali-hydrothermal treatment, and the effects of this Nano surface on the behaviors of human MG-63 osteoblasts, human gingival epithelial cells (HGECs) and human gingival fibroblasts (HGFs) were evaluated in comparison with a smooth titanium surface (Smooth) by polishing and a micro-rough titanium surface (Micro) by sandblasting and acid etching. In addition, the impacts of these different surface morphologies on human THP-1 macrophage polarization and Streptococcus mutans attachment were also assessed. Our findings showed that the nanostructured surface enhanced the osteogenic activity of MG-63 cells (Nano=Micro>Smooth) at the same time that it improved the attachment of HGECs (Nano>Smooth>Micro) and HGFs (Nano=Micro>Smooth). Furthermore, the surface with nanotexture did not affect macrophage polarization (Nano=Micro=Smooth), but did reduce initial bacterial adhesion (Nano Collapse

Key Words

• antimicrobial effect
• macrophage polarization
• nanotopography
• osteogenic differentiation
• soft tissue barrier

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MESH Headings

• Cell Adhesion/drug effects
• Cell Line
• Cell Polarity/drug effects
• Epithelial Cells/cytology
• Epithelial Cells/drug effects
• Fibroblasts/cytology
• Fibroblasts/drug effects
• Gingiva/cytology
• Gingiva/drug effects
• Humans
• Macrophages/cytology
• Macrophages/drug effects
• Mouth/microbiology
• Nanostructures/chemistry
• Osteoblasts/cytology
• Streptococcus mutans/drug effects
• Surface Properties
• Titanium/chemistry
• Titanium/pharmacology

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Effects of cryopreservation on ultrastructural morphology of white shrimp (Litopenaeus vannamei) sperm

BACKGROUND

The structural integrity of a spermatozoon is very important for the processes of fertilization and embryo development.

OBJECTIVE

To provide valuable data for developing better cryopreservation techniques for shrimp sperm.

MATERIALS AND METHODS

Using scanning electron microscopy and transmission electron microscopy, we examined the morphological alteration of Litopenaeus vannamei sperm after cryopreservation with different concentrations of dimethylsulfoxide (DMSO).

RESULTS

We found that the damaged post-thaw sperm presented either vesiculated acrosomal contents, wrinkled membranes, perforated membranes, and loss of the acrosomal spike. The seriously damaged sperm showed missing acrosomal spikes, deformed nuclei, burst nuclear membranes, and vacuolated nuclei. In addition, we found that the post-thaw sperm stored with 5% DMSO had the highest viability rate and lowest DNA damage coefficient by eosin-nigrosin staining and comet assay.

CONCLUSION

Our results suggested that cryopreservation has deleterious effects on ultrastructural morphology of L. vannamei sperm, especially on acrosomal spikes and membranes.

Selective responses of human gingival fibroblasts and bacteria on carbon fiber reinforced polyetheretherketone with multilevel nanostructured TiO2

The long-term success of dental implants relies not only on stable osseointegration but also on the integration of implant surfaces with surrounding soft tissues. In our previous work, titanium plasma immersion ion implantation (PIII) technique was applied to modify the carbon-fiber-reinforced polyetheretherketone (CFRPEEK) surface, constructing a unique multilevel TiO2 nanostructure thus enhancing certain osteogenic properties. However, the interactions between the modified surface and soft-tissue cells are still not clear. Here, we fully investigate the biological behaviors of human gingival fibroblasts (HGFs) and oral pathogens on the structured surface, which determine the early peri-implant soft tissue integration. Scanning electron microscopy (SEM) shows the formation of nanopores with TiO2 nanoparticles embedded on both the sidewall and bottom. In vitro studies including cell adhesion, viability assay, wound healing assay, real-time PCR, western blot and enzyme-linked immunosorbent assay (ELISA) disclose improved adhesion, migration, proliferation, and collagen secretion ability of HGFs on the modified CFRPEEK. Moreover, the structured surface exhibits sustainable antibacterial properties towards Streptococcus mutans, Fusobacterium nucleatum and Porphyromonas gingivalis. Our results reveal that the multilevel TiO2 nanostructures can selectively enhance soft tissue integration and inhibit bacterial reproduction, which will further support and broaden the adoption of CFRPEEK materials in dental fields.

Large-pore mesoporous Ca–Si-based bioceramics with high in vitro bioactivity and protein adsorption capability for bone tissue regeneration

A new type of large pore mesoporous Ca–Si-based bioceramics demonstrates high in vitro bioactivity and protein adsorption capability.

Isolation and characterization of novel polymorphic microsatellite loci in large yellow croaker (Larimichthys crocea)

The large yellow croaker (Larimichthys crocea) is one of the largest marine net-cage cultured species in the oceans around China. In the present study, we isolated and characterized 13 polymorphic microsatellite markers from genomic libraries of L. crocea. Loci were screened for 10 wild specimens from 2 sites in southeast of China. All loci were polymorphic. The number of alleles per locus ranged from 2 to 21. The expected heterozygosity ranged from 0.233 to 0.838 and observed heterozygosity ranged from 0.527 to 0.935. Eleven loci were highly informative (polymorphic information content >0.5). Significant deviation from Hardy-Weinberg equilibrium was observed at 3 loci after Bonferroni's correction. The microsatellite loci may be valuable tools for studying the genetic diversity and genetic structure for conservation planning of the fish.

On random-effects meta-analysis

Meta-analysis is widely used to compare and combine the results of multiple independent studies. To account for between-study heterogeneity, investigators often employ random-effects models, under which the effect sizes of interest are assumed to follow a normal distribution. It is common to estimate the mean effect size by a weighted linear combination of study-specific estimators, with the weight for each study being inversely proportional to the sum of the variance of the effect-size estimator and the estimated variance component of the random-effects distribution. Because the estimator of the variance component involved in the weights is random and correlated with study-specific effect-size estimators, the commonly adopted asymptotic normal approximation to the meta-analysis estimator is grossly inaccurate unless the number of studies is large. When individual participant data are available, one can also estimate the mean effect size by maximizing the joint likelihood. We establish the asymptotic properties of the meta-analysis estimator and the joint maximum likelihood estimator when the number of studies is either fixed or increases at a slower rate than the study sizes and we discover a surprising result: the former estimator is always at least as efficient as the latter. We also develop a novel resampling technique that improves the accuracy of statistical inference. We demonstrate the benefits of the proposed inference procedures using simulated and empirical data.

Doubly Robust Learning for Estimating Individualized Treatment with Censored Data

Individualized treatment rules recommend treatments based on individual patient characteristics in order to maximize clinical benefit. When the clinical outcome of interest is survival time, estimation is often complicated by censoring. We develop nonparametric methods for estimating an optimal individualized treatment rule in the presence of censored data. To adjust for censoring, we propose a doubly robust estimator which requires correct specification of either the censoring model or survival model, but not both; the method is shown to be Fisher consistent when either model is correct. Furthermore, we establish the convergence rate of the expected survival under the estimated optimal individualized treatment rule to the expected survival under the optimal individualized treatment rule. We illustrate the proposed methods using simulation study and data from a Phase III clinical trial on non-small cell lung cancer.

A Likelihood-Based Framework for Association Analysis of Allele-Specific Copy Numbers

Copy number variants (CNVs) and single nucleotide polymorphisms (SNPs) co-exist throughout the human genome and jointly contribute to phenotypic variations. Thus, it is desirable to consider both types of variants, as characterized by allele-specific copy numbers (ASCNs), in association studies of complex human diseases. Current SNP genotyping technologies capture the CNV and SNP information simultaneously via fluorescent intensity measurements. The common practice of calling ASCNs from the intensity measurements and then using the ASCN calls in downstream association analysis has important limitations. First, the association tests are prone to false-positive findings when differential measurement errors between cases and controls arise from differences in DNA quality or handling. Second, the uncertainties in the ASCN calls are ignored. We present a general framework for the integrated analysis of CNVs and SNPs, including the analysis of total copy numbers as a special case. Our approach combines the ASCN calling and the association analysis into a single step while allowing for differential measurement errors. We construct likelihood functions that properly account for case-control sampling and measurement errors. We establish the asymptotic properties of the maximum likelihood estimators and develop EM algorithms to implement the corresponding inference procedures. The advantages of the proposed methods over the existing ones are demonstrated through realistic simulation studies and an application to a genome-wide association study of schizophrenia. Extensions to next-generation sequencing data are discussed.

Penalized Q-Learning for Dynamic Treatment Regimens

A dynamic treatment regimen incorporates both accrued information and long-term effects of treatment from specially designed clinical trials. As these trials become more and more popular in conjunction with longitudinal data from clinical studies, the development of statistical inference for optimal dynamic treatment regimens is a high priority. In this paper, we propose a new machine learning framework called penalized Q-learning, under which valid statistical inference is established. We also propose a new statistical procedure: individual selection and corresponding methods for incorporating individual selection within penalized Q-learning. Extensive numerical studies are presented which compare the proposed methods with existing methods, under a variety of scenarios, and demonstrate that the proposed approach is both inferentially and computationally superior. It is illustrated with a depression clinical trial study.

Strontium delivery on topographical titanium to enhance bioactivity and osseointegration in osteoporotic rats

Strontium-substituted hierarchical Ti surface can enhance the osseointegration by both increasing new bone formation and reducing bone resorption under osteoporotic conditions.

Short-term therapeutic drug monitoring of mycophenolic acid reduces infection: a prospective, single-center cohort study in Chinese living-related kidney transplantation

BACKGROUND

The role of therapeutic drug monitoring (TDM) of mycophenolic acid (MPA) in kidney transplant recipients (KTRs) is not clear. We performed a prospective cohort study to evaluate the efficiency of MPA TDM in the Chinese population.

METHODS

A total of 183 living-related KTRs were studied; 101 KTRs received controlled-dose mycophenolate mofetil (MMF) (the CD group), and 82 patients received fixed-dose MMF (the FD group). MPA exposure was measured at days 3, 7, 14, and 30 in the CD group, and at day 30 in the FD group. The primary endpoint was treatment failure (a composite of acute rejection, graft loss, death, or MMF discontinuation) at 12 months post transplantation.

RESULTS

In the CD group, with a starting MMF dose of 2 g/day, approximately 35% of patients had high MPA levels, which were >60 mg × h/L, and mean MPA levels were 59.17 mg × h/L and 61.38 mg × h/L for the CD and FD groups, respectively (P = 0.588). After adjusting MMF dose, MPA exposures in the CD group at day 30 were lower than those in the FD group at day 30 (54.06 vs. 61.38, P = 0.004). At month 12, the CD group had fewer infections (16.8% vs. 31.7%, P = 0.018) with no difference in treatment failure, acute rejection, diarrhea, or anemia.

CONCLUSIONS

KTRs can benefit from short-term TDM of MPA in reducing infection, without increasing acute rejection.

Long-term outcome of HLA-haploidentical hematopoietic SCT without in vitro T-cell depletion for adult severe aplastic anemia after modified conditioning and supportive therapy

HLA-haploidentical hematopoietic SCT (HSCT) is an option for severe aplastic anemia (SAA) patients. Here, we evaluated the outcomes of 26 adult-SAA patients who received HLA-haploidentical HSCT in five transplant centers in southwestern China. Most of the patients in this study failed prior therapy and were transfused heavily before the transplantation. The patients received fludarabine+cyclophosphamide+antithymocyte globulin as conditioning regimens and then unmanipulated peripheral blood plus marrow transplantation. Micafungin, i.v. Ig and recombinant human TPO were used for post-grafting infection prevention and supportive care. Of 26 patients, 25 achieved engraftment at a median of 13 days (range, 11-19 days) after HSCT. One of 25 patients experienced graft rejection and did not achieve sustained engraftment after second HSCT. Therefore, the final engraftment rate was 92.3%. Three of 25 (12%) patients developed acute GVHD, 10 of 25 (40%) patients developed chronic GVHD (9 with limited whereas the other with extensive). The OS rate was 84.6% and the average follow-up time was 1313.2 (738-2005) days for surviving patients. This encouraging result suggests that HLA-haploidentical HSCT is an effective therapeutic option for adults with acquired SAA if an HLA-identical donor is not available.