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Objective:To develop a deep learning model which can automatically and accurately detect osteoporotic vertebral compression fractures (OVCF) based on artificial intelligence.Methods:MRI images of 500 patients diagnosed with OVCF at The First People＇s Hospital of Guangzhou from January 2019 to October 2021 were collected retrospectively. There were 396 males and 204 females, with an age of (74.5±6.0) years. The T value of bone mineral density was -2.9±0.8. The fracture segments were L1 in 128 cases, L2 in 113 cases, L3 in 109 cases, L4 in 115 cases, and L5 in 108 cases. The multimodal layered converged network was used to train, test, and verify the robustness and generalization ability of a deep learning model based on MRI images of OVCF. The grad-cam was applied to visualize the results. The diagnostic value of the model for OVCF was assessed by comparing the diagnoses between the artificial intelligence model and 2 senior spinal surgeons on the MRI images of 30 OVCF patients randomized from the 500 ones.Results:Of the precise auxiliary diagnosis model for OVCF based on MRI images, the diagnostic accuracy was 96.7%, the sensitivity 93.5%, the specificity 88.9%, the positive predictive value 100.0%, and the negative predictive value 86.6%, all significantly higher than those of the 2 senior spinal surgeons (70.0%, 72.7%, 28.6%, 82.1%, and 28.6%) ( P<0.05). Conclusion:The present study has successfully established a deep learning model which can automatically and accurately diagnose OVCF based on MRI images, showing a high diagnostic efficiency than human spinal surgeons.
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Objective:To fabricate tAu@glutathione(GSH)@Gd nanoprobe for tumor angiogenesis bimodal (MR/CT) imaging, and evaluate its characteristics and potential for MR/CT imaging in vivo. Methods:The tAu@GSH@Gd nanoprobes were constructed by encapsulating Au and Gd atoms into the GSH shell with cyclic asparagine-glycine-arginine (cNGR) peptide conjugation. EMT-6 BALB/c mice subcutaneous transplantation tumor models were established ( n=30) and divided into blank control group (saline), control group (Au@GSH@Gd nanoparticles) and experimental group (tAu@GSH@Gd nanoprobes) ( n=10 in each group). In vivo MR/CT imaging and distribution study were performed at different time points after tail intravenously injection. Relative MR signal value and relative CT value of tumor site and main organs in mice were used to evaluate MR/CT imaging property and biological distribution. After that, tumor tissues were collected for silver staining to study the accumulation of Au@GSH@Gd nanoparticles and tAu@GSH@Gd nanoprobes. Independent-sample t test was used for data analysis. Results:The tAu@GSH@Gd nanoprobes were (6.40±0.22) nm with high T 1 relaxation efficiency ((36.91±0.07) mmol·L -1·s -1). MR/CT imaging of tAu@GSH@Gd nanoprobes showed good performance in vitro. In vivo MR/CT imaging demonstrated MR/CT imaging of tumor was significantly enhanced by tAu@GSH@Gd nanoprobes after 2 h post injection. The strongest enhancement was observed at 24 h, with an increased relative MR signal value from 1.04±0.12 (before injection) to 1.84±0.26 ( t=12.61, P=0.006), and increased relative CT value from 1.01±0.04 (before injection) to 1.95±0.05 ( t=15.34, P=0.004). The highest MR/CT effect in control group appeared at 16 h, with the relative MR signal value of 1.50±0.06 and the relative CT value of 1.53±0.10, which were significantly lower than those in experimental group (1.84±0.26 and 1.95±0.05; t values: 5.35 and 16.46, both P<0.05). Distribution in normal tissues showed that most of tAu@GSH@Gd nanoprobes were metabolized through the kidneys. Tissue silver staining experiment verified the tumor angiogenesis targeting effect. Conclusion:The tAu@GSH@Gd nanoprobes exhibit favorable tumor angiogenesis target MR/CT imaging ability, providing a new design concept and basis for assessing tumor angiogenesis.
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The development of multifunctional nanocontrast agents with high sensitivity, high specificity, and low toxicity so that they can precisely localize tumors and reflect tumor biological information in real time is the core of promoting the development of tumor molecular imaging technology and realizing early and precise tumor diagnosis. Polydopamine (PDA) nanomaterials are bionanomaterials with a structure extremely similar to that of natural melanin. They can be easily fabricated and functionalized, and can achieve controlled assembly of functional molecules such as contrast components and targeting ligands via metal coordination, π-π stacking, electrostatic adsorption, and other methods. They have good biocompatibility and biodegradability, show great potential for clinical translation, and have been widely used in molecular imaging of tumors. In this review paper, the preclinical studies of PDA nanoparticles are reviewed as well as the synthesis methods, functionalized modification, and assembly strategies of PDA nanoparticles and their applications in tumor molecular imaging. The development trends of PDA are also presented to promote their application in the field of tumor molecular imaging.
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Objective To study the expression level of cathepsin S in elderly patients with different degree of coronary heart disease(CHD),and to evaluate the correlation between cathepsin S level and the severity of CHD.Methods A total of 126 elderly patients with CHD were enrolled,including 36 cases with acute myocardial infarction(group AMI),48 cases with unstable angina(group UAP),and 42 cases with stable angina(group SAP).During the same period,40 healthy subjects were selected as controls.Venous blood was collected immediately after admission.Arterial blood was taken through radial/femoral artery sheath in AMI patients who underwent primary percutaneous coronary intervention,and coronary arterial blood was taken in AMI patients undergoing intracoronary thrombus aspiration.SYNTAX score was assessed in patients undergoing coronary angiography.Serum levels of high sensitivity C reactive protein(hs-CRP),matrix metalloproteinase-9 (MMP-9) and cathepsin S were determined in all specimens and compared between groups.Results Serum levels of cathepsin S,MMP-9 and hs-CRP were higher in CHD patients than in the control group(P＜0.05).Among CHD patients,group AMI had the highest serum levels of cathepsin S,MMP-9 and hs-CRP,followed by group UAP and group SAP(F =106.830,197.035 and 310.442,all P =0.000).Spearman's rank correlation test suggested that cathepsin S level was positively correlated with serum levels of MMP-9 (r=0.816,P =0.000)and hs-CRP(r =0.827,P =0.000).SYNTAX score was positively correlated with serum levels of cathepsin S(r=0.581,P=0.000),MMP-9(r=0.511,P=0.000),and hs-CRP (r=0.557,P =0.000).Among the 24 patients with AMI who underwent intracoronary thrombus aspiration,the levels of cathepsin S,MMP-9 and hs-CRP were higher in coronary artery blood than in peripheral artery blood (t =217.288,3.177 and 681.479,all P =0.000).Cathepsin S and hs-CRP levels in peripheral arterial blood had positive correlations with those in coronary arterial blood respectively(r =0.962 and 0.494,P =0.000 and 0.014),but such correlation between in peripheral arterial blood versus in coronary artery blood was not found in MMP-9 levels (r =-0.188,P =0.380).Conclusions Serum cathepsin S level is higher in elderly CHD patients than in healthy people,increases along with the increased severity of CHD,and positively correlates with the degree of coronary stenosis.
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Objective@#To explore the dynamic variation trend of bronchial wall thickness (BWT) in severely burned patients combined with inhalation injury, and to determine the value of BWT to prognosis of patients.@*Methods@#Forty-three severely burned patients with inhalation injury hospitalized in Intensive Burn Department of the Affiliated Hospital of Nankai University (Tianjin No.4 Hospital) from July to November 2016, conforming to the study criteria, were divided into survival group (n=27) and death group (n=16) according to the prognosis of patients within 14 days after admission. All patients underwent fiberoptic bronchoscopy and inhalation injury rating based on abbreviated injury scale at admission. High resolution CT examination was performed in patients of two groups at admission and 24 h post admission, 3, 7, and 14 d post admission to measure the BWT of right superior lobar bronchus trunk opening. Receiver operating characteristic curves of rating of inhalation damage at admission and BWT at admission were drawn to evaluate the predictive value for death of 43 patients. Data were processed with chi-square test, independent sample t test, Wilcoxon rank sum test, analysis of variance for repeated measurement and least-significant difference-t test.@*Results@#(1) The numbers of patients rated as 0, 1, 2, 3, and 4 grade for inhalation injury in survival group and death group were 0, 19, 6, 2, and 0, and 0, 2, 7, 7, and 0, respectively. There were statistically significant differences between the two groups (Z=-3.79, P<0.01). (2) BWT of patients in death group at admission and 24 h post admission, 3, 7, and 14 d post admission was respectively (2.72±0.26), (3.18±0.22), (2.98±0.18), (2.29±0.17), and (1.45±0.21) mm, which was significantly larger than (2.24±0.15), (2.49±0.15), (1.51±0.17), (1.04±0.16), and (1.01±0.13) mm in survival group (t=7.55, 12.14, 27.11, 19.99, 7.11, P<0.01). BWT of patients in survival group and death group at 24 h post admission, 3, 7, and 14 d post admission showed statistically significant difference when compared with that at admission within the corresponding group (t=5.97, 16.63, 28.21, 38.57, 5.34, 3.31, 4.39, 6.48, P<0.01). BWT of patients in survival group and death group on 3, 7, and 14 d post admission was significantly smaller than that at 24 h post admission within the corresponding group (t=22.27, 34.02, 45.03, 2.77, 10.53, 10.59, P<0.01). BWT of patients in survival group and death group on 7 and 14 d post admission was significantly smaller than that on 3 d post admission within the corresponding group (t=10.49, 18.26, 9.57, 11.44, P<0.01). BWT of patients in survival group and death group on 14 d post admission was significantly smaller than that on 7 d post admission within the corresponding group (t=6.97, 6.15, P<0.01). (3) The total areas under ROC curves of inhalation injury rating at admission and BWT at admission for predicting death of 43 patients were 0.880 and 0.956, respectively (with 95% confidence intervals 0.768-0.991, 0.882-1.000, P<0.05). Grade 1.5 and 2.75 mm were respectively chosen as the optimal threshold values of inhalation injury rating at admission and BWT at admission, with sensitivity of 87.50%, 83.33% and specificity of 77.78%, 96.00%, respectively.@*Conclusions@#The BWT of survived and dead patients with severe burn and inhalation injury increases significantly post burn, while the BWT of survived patients restores to normal level faster. BWT can be used to assess the severity of inhalation injury and to predict death in severely burned patients combined with inhalation injury.
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Objective To investigate the influence of early growth response gene-1 (EGR1) on the autophagy of host cells following infection with human T cell leukemia virus type 1 (HTLV-1).MethodsA HTLV-1-positive cell line MT2 was co-cultured with HeLa cells for 24 h to construct the virus early infection model.Immunoblotting assay was used to detect the expression of HTLV-1 core protein p19 and EGR1.Luciferase reporter gene analysis was used to detect the transcriptional activity of 5′-regulatory sequence of EGR1 at different time points after co-culturing.An effective small interfering RNA (siRNA) targeting EGR1 was screened out and transfected into HeLa cells by Lipofectamine 2000.Then the transfected HeLa cells were co-cultured with the HTLV-1-positive cell line MT2 for 24 h.Immunoblotting assay was used to detect HTLV-1 core protein p19, EGR1 and autophagy-related protein LC3.Real-time PCR was performed to detect viral load.Autophagosome was analyzed by immunofluorescence after co-culturing.Results The expression of EGR1 and the transcriptional activity of pEGR1-luc gradually increased after co-culturing HeLa cells with MT2 cells for 8 h (P<0.01).The expression of EGR1 was positively correlated with host cell autophagy following HTLV-1 infection.The effective siRNA for silencing the expression of EGR1 was obtained and named as siE2.The viral load, the expression of HTLV-1 core protein p19 and the proportion of LC3B/LC3A in the co-culture model were markedly down-regulated by RNA interference with siE2, which was concomitant with a persistent decrease of intracellular autophagosome (P<0.01).Conclusion EGR1 is associated with host cell autophagy and viral replication in HTLV-1 infection.
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Objective To explore the effects of different doses of contrast agent (CA) on types of time-signal intensity curves (TICs) and semi-quantitative parameters after dynamic contrast-enhanced MRI (DCE-MRI) on Walker 256 murine breast tumor model.Methods A total of 12 rats burdened Walker256 breast cancer models were established and divided into 3 groups randomly, 4 in each group.Routine MR and DCE-MRI scans of the rats using Bruker Pharmascan 7T MR scanner were performed.Doses for the 3 groups were 0.2, 0.3, and 0.5 mmol/kg, respectively.MR data, TICs types and semi-quantitative parameters from each different dose group were statistically studied and compared to observe the differences.Results Tumors were enhanced significantly after injection.The types of TICs in all tumors were the Ⅲ pattern which was not influenced by CA doses.Semi-quantitative parameters of first enhancement (Efirst), maximal enhancement (Emax), washout enhancement (Ewash), and signal enhancement ratio (SER) showed statistical differences among the three dose groups (P＜0.05).Semi-quantitative parameters of time to peak (Tpeak) and washout velocity (Vwash) showed no statistical differences among the three dose groups (P＞0.05).Mean signal intensity of each group was highly negatively linear correlated with scan times after the peak (r=-0.972, P=0.000;r=-0.971, P=0.000;r=-0.989, P=0.000).The washout slope (slopewash) showed no statistical differences among the three groups (P＞0.05).Conclusions Injection doses of CA didn't change the TIC type, Tpeak, Vwash, and Slopewash.These parameters are comparable among different medical centers and can be considered as prior parameters to monitor the efficacy of neoadjuvant chemotherapy.