Objective:To rapidly and accurately detect volumetric modulated arc therapy (VMAT) plans with potentially inaccurate radiation doses.Methods:The measurement-based dosimetric verification result of 196 VMAT plans obtained using ArcCHECK phantoms were retrospectively collected. Independent dosimetric calculation and verification were conducted for these plans using the ArcherQA system based on a fast Monte Carlo algorithm. The gamma passing rates of dosimetric verification using ArcCHECK phantom and the ArcherQA system were compared, followed by their correlation analysis and linear regression fitting. The ArcherQA system′s gamma passing rate threshold used to detect positive dosimetric verification result obtained using ArcCHECK phantoms, as well as the specificity of the detection, were calculated. Based on this gamma passing rate threshold, another 50 VMAT plans were selected as a test set to assess the ArcherQA system′s ability to detect positive measurement-based dosimetric verification result.Results:The average gamma passing rates for the dosimetric verification of the VMAT plans using the ArcherQA system and ArcCHECK phantoms were 97.28% and 96.57% (3%/3 mm, TH=10%), respectively. Both rates had a correlation coefficient of 0.71 ( P < 0.01) and a linear fitting coefficient of 0.54 ( R2=0.51). When the gamma passing rate for dosimetric verification using ArcCHECK phantoms was set at 90% (3%/2 mm, TH=10%), the gamma passing rate threshold for dosimetric verification using the ArcherQA system should be adjusted to 94.8% to detect all VMAT plans with positive dosimetric verification result obtained using ArcCHECK phantoms, with a specificity of 67.8%. Using this threshold, the ArcherQA system detected all VMAT plans in the test set for which ArcCHECK phantom-based measurement yielded positive dosimetric verification result. Conclusions:By determining an appropriate gamma passing rate threshold, the ArcherQA system can rapidly and accurately detect VMAT plans with potentially inaccurate doses, thus ensuring treatment accuracy and improving work efficiency.

Objective To develop a deep learning-based denoising model for accelerating Monte Carlo(MC)simulation of electronic portal imaging device(EPID)transit dose images.Methods A total of 500 EPID fields were collected from 100 lung cancer patients undergoing 5-field intensity-modulated radiotherapy,with 400 fields randomly selected as training set,50 fields as validation set,and 50 fields as test set.EPID transit dose image datasets with low particle counts(1×107)and high particle counts(1×109)were simulated using the GPU-accelerated MC dose calculation engine ARCHER.A denoising network model named SUNet was constructed based on Swin Transformer and U-Net,and trained using low-particle-count images as input and high-particle-count images as output.Following training,SUNet model was used to denoise low-particle-count EPID images in the test set.Denoising performance was evaluated using structural similarity index(SSIM),peak signal-to-noise ratio(PSNR),and Gamma passing rates(3%/2 mm),and the computational efficiency of MC simulation combined with SUNet model was analyzed.Results Compared with the original low-particle-count images,the SUNet-denoised images showed significantly improved quality,reduced noise points,and smoother dose distribution.When benchmarked against high-particle-count images,the SUNet-denoised images achieved an average SSIM greater than 0.9,an average PSNR higher than 32 dB,and an average gamma passing rate exceeding 90%.The MC simulation combined with SUNet model required only 1.88 s to simulate a single EPID transit dose image,representing an approximate 40-fold improvement in computational efficiency as compared with high-particle-count MC simulation.Conclusion The deep learning-based denoising model substantially accelerates MC simulation of EPID transit dose images while preserving both image quality and dose accuracy,which provides possibilities for EPID-basedin vivodose verification.

Objective:To rapidly and accurately detect volumetric modulated arc therapy (VMAT) plans with potentially inaccurate radiation doses.Methods:The measurement-based dosimetric verification result of 196 VMAT plans obtained using ArcCHECK phantoms were retrospectively collected. Independent dosimetric calculation and verification were conducted for these plans using the ArcherQA system based on a fast Monte Carlo algorithm. The gamma passing rates of dosimetric verification using ArcCHECK phantom and the ArcherQA system were compared, followed by their correlation analysis and linear regression fitting. The ArcherQA system′s gamma passing rate threshold used to detect positive dosimetric verification result obtained using ArcCHECK phantoms, as well as the specificity of the detection, were calculated. Based on this gamma passing rate threshold, another 50 VMAT plans were selected as a test set to assess the ArcherQA system′s ability to detect positive measurement-based dosimetric verification result.Results:The average gamma passing rates for the dosimetric verification of the VMAT plans using the ArcherQA system and ArcCHECK phantoms were 97.28% and 96.57% (3%/3 mm, TH=10%), respectively. Both rates had a correlation coefficient of 0.71 ( P < 0.01) and a linear fitting coefficient of 0.54 ( R2=0.51). When the gamma passing rate for dosimetric verification using ArcCHECK phantoms was set at 90% (3%/2 mm, TH=10%), the gamma passing rate threshold for dosimetric verification using the ArcherQA system should be adjusted to 94.8% to detect all VMAT plans with positive dosimetric verification result obtained using ArcCHECK phantoms, with a specificity of 67.8%. Using this threshold, the ArcherQA system detected all VMAT plans in the test set for which ArcCHECK phantom-based measurement yielded positive dosimetric verification result. Conclusions:By determining an appropriate gamma passing rate threshold, the ArcherQA system can rapidly and accurately detect VMAT plans with potentially inaccurate doses, thus ensuring treatment accuracy and improving work efficiency.

Objective To develop a deep learning-based denoising model for accelerating Monte Carlo(MC)simulation of electronic portal imaging device(EPID)transit dose images.Methods A total of 500 EPID fields were collected from 100 lung cancer patients undergoing 5-field intensity-modulated radiotherapy,with 400 fields randomly selected as training set,50 fields as validation set,and 50 fields as test set.EPID transit dose image datasets with low particle counts(1×107)and high particle counts(1×109)were simulated using the GPU-accelerated MC dose calculation engine ARCHER.A denoising network model named SUNet was constructed based on Swin Transformer and U-Net,and trained using low-particle-count images as input and high-particle-count images as output.Following training,SUNet model was used to denoise low-particle-count EPID images in the test set.Denoising performance was evaluated using structural similarity index(SSIM),peak signal-to-noise ratio(PSNR),and Gamma passing rates(3%/2 mm),and the computational efficiency of MC simulation combined with SUNet model was analyzed.Results Compared with the original low-particle-count images,the SUNet-denoised images showed significantly improved quality,reduced noise points,and smoother dose distribution.When benchmarked against high-particle-count images,the SUNet-denoised images achieved an average SSIM greater than 0.9,an average PSNR higher than 32 dB,and an average gamma passing rate exceeding 90%.The MC simulation combined with SUNet model required only 1.88 s to simulate a single EPID transit dose image,representing an approximate 40-fold improvement in computational efficiency as compared with high-particle-count MC simulation.Conclusion The deep learning-based denoising model substantially accelerates MC simulation of EPID transit dose images while preserving both image quality and dose accuracy,which provides possibilities for EPID-basedin vivodose verification.

Objective:To evaluate the role of the AMP-activated protein kinase (AMPK)-silent information regulator 1 (SIRT1)-nuclear factor-κB (NF-κB) signaling pathway in reduction of brain injury by panax notoginseng saponins (PNS) in mechanically ventilated rats.Methods:Seventy-two SPF-grade male Sprague-Dawley rats, aged 10 weeks, weighing 357-377 g, were divided into 6 groups ( n=12 each) by a random number table method: sham operation group, model group, PNS low dose group, PNS medium dose group, PNS high dose group, and PNS high dose+ compound C group. PNS 12.5, 25 and 50 mg/kg were intraperitoneally injected in PNS low dose group, PNS medium dose group and PNS high dose group, respectively. In PNS high dose+ compound C group, PNS 50 mg/kg was intraperitoneally injected, and 10 min later compound C 0.2 mg/kg was injected via the tail vein. Normal saline 10 ml/kg was intraperitoneally injected in sham operation group and model group. Drugs or normal saline was injected at 30 min before mechanical ventilation in each group. Mechanical ventilation model: The animals were mechanically ventilated for 6 h, with ventilation frequency 40 times/min, tidal volume 40 ml/kg in model group; The animals were mechanically ventilated for 6 h, with tidal volume 10 ml/kg in sham operation group. Morris water maze test was used to detect the learning and memory function of rats, the concentrations of serum interleukin-1beta (IL-1β), IL-6, tumor necrosis factor-alpha (TNF-α) and dopamine (DA) were detected by enzyme-linked immunosorbent assay, the neuronal counts in the hippocampal CA1 region were determined by Nissl staining, and the expression of P2Y1 purine receptor (P2Y1R), dysbindin-1 and AMPK in hippocampal CA1 region was detected by Western blot. The phosphorylated SIRT1 (p-SIRT1) to SIRT1 ratio and phosphorylated NF-κB p65 (p-NF-κB p65) to NF-κB ratio in hippocampal CA1 region was calculated. Results:Compared with sham operation group, the escape latency was significantly prolonged, the number of crossing the original platform quadrant was reduced, the time of staying at the target platform quadrant was shortened, the serum concentrations of IL-1β, IL-6 and TNF-α were increased, the serum DA concentration was decreased, the nerve count in hippocampal CA1 region was decreased, the expression of P2Y1R and dysbindin-1 was up-regulated, the expression of AMPK was down-regulated, the p-SIRT1/SIRT1 ratio was decreased, and the p-NF-κB p65/NF-κB p65 ratio was increased in model group ( P<0.05). Compared with model group, the escape latency was significantly shortened, the number of crossing the original platform quadrant was increased, the time of staying at the target platform quadrant was prolonged, the serum concentrations of IL-1β, IL-6 and TNF-α were decreased, the serum DA concentration was increased, the nerve count in hippocampal CA1 region was increased, the expression of P2Y1R and dysbindin-1 was down-regulated, the expression of AMPK was up-regulated, the p-SIRT1/SIRT1 ratio was increased, and the p-NF-κB p65/NF-κB p65 ratio was decreased in PNS low dose group, PNS medium dose group and PNS high dose group ( P<0.05). Compared with PNS high dose group, the escape latency was significantly prolonged, the number of crossing the original platform quadrant was reduced, the time of staying at the target platform quadrant was shortened, the serum concentrations of IL-1β, IL-6 and TNF-α were increased, the serum DA concentration was decreased, the nerve count in hippocampal CA1 region was decreased, the expression of P2Y1R and dysbindin-1 was up-regulated, the expression of AMPK was down-regulated, the p-SIRT1/SIRT1 ratio was decreased, and the p-NF-κB p65/NF-κB p65 ratio was increased in PNS high dose+ compound C group ( P<0.05). Conclusions:The mechanism by which PNS reduces brain injury may be related to activation of the AMPK-SIRT1-NF-κB signaling pathway in mechanically ventilated rats.

Objective:To investigate the effect of myeloid-derived suppressor cells (MDSC) on guanylate binding protein 1 (GBP1) in promoting the proliferation of glioma U87 cells and its mechanism.Methods:Glioma cells U87 with GBP1 overexpression (U87-GBP1) and control cells U87-Lacz transfected with empty vector were used as experimental cells. The mRNA and protein expressions of GBP1 and chemokine (C-C motif) ligand 2 (CCL2) in two groups of cells were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), Western blot and enzyme linked immunosorbent assay (ELISA), and the proliferation of U87 cells were detected by CCK-8. CD14 + monocytes and CD3 + T lymphocytes were isolated from peripheral blood of healthy people by immunomagnetic beads. The CD14 + monocytes were treated with culture medium of U87-Lacz cells or U87-GBP1 cells, and then the cells were divided into U87-Lacz culture medium group and U87-GBP1 culture medium group. The proportion of MDSC in CD14 + monocytes was analyzed by flow cytometry. CD14 + monocytes treated by two culture medium groups were cocultured with activated CD3 + T lymphocytes, and flow cytometry was used to detect the proliferation of activated CD3 + T lymphocytes. Monocytes untreated by U87 cells culture medium or activated CD3 + T lymphocytes were used as the control group. CD14 + monocytes were treated with U87-Lacz or U87-GBP1 cell culture medium anti-human CCL2 antibody, which were U87-Lacz+anti-CCL2 culture medium group and U87-GBP1 + anti-CCL2 culture medium group, and the proportion of MDSC in CD14 + monocytes was analyzed by flow cytometry. U87-GBP1 and U87-Lacz cells were inoculated into BALB/c nude mice to cause tumors in the brain. One week later, they were divided into chemokine (C-C motif) receptor 2 (CCR2) inhibitor RS504393 treatment group (U87-Lacz + RS nude mice group and U87-GBP1+RS nude mice group) and untreated control group (U87-Lacz nude mice group and U87-GBP1 nude mice group). After 30 days, the mice were sacrificed and the brain, spleen and bone marrow were isolated. Hematoxylin-eosin (HE) staining was used to observe the transplanted tumors in the brain of nude mice, and the volume of transplanted tumor was calculated, and flow cytometry was used to detect the proportion of MDSC in the tissues. Results:The protein expression of GBP1 in U87-GBP1 cells was significantly higher than that in U87-Lacz cells, but there was no significant difference in cell proliferation level between the two groups in vitro ( P > 0.05). The proportion of MDSC in U87-GBP1 culture medium group was significantly higher than that of U87-Lacz culture medium group [(7.75±0.80)% vs. (4.50±0.08)%], and both groups were higher than that of control group [(2.55±0.31)%)] ( F = 18.27, P = 0.002). The percentage of activated CD3 + T lymphocytes in U87-GBP1 culture medium group was lower than that in U87-Lacz culture medium group [(47.38±0.08)% vs. (61.70±5.05)%, P = 0.040]. The relative expression of CCL2 mRNA in U87-GBP1 cells and the expression level of CCL2 protein in U87-GBP1 cell culture medium [30.66±0.17 and (1 005.00±12.23) ng/L] were higher than those in U87-Lacz cells [1.29±0.15 and (111.60±11.44) ng/L] (both P < 0.01), the proportions of MDSC in U87-Lacz + anti-CCL2 culture medium group and U87-GBP1 + anti-CCL2 culture medium group was lower than those in U87-Lacz culture medium group and U87-GBP1 culture medium group (all P < 0.05). The volume of transplanted brain tumor in U87-GBP1 nude mice group was larger than that in U87-Lacz nude mice group; the volume of transplanted brain tumor in U87-GBP1 + RS nude mice group and U87-Lacz + RS nude mice group increased more slowly than the corresponding nude mice group without treatment, and the differences were statistically significant (all P < 0.05); the proportions of MDSC in transplanted brain tumor, spleen and bone marrow in U87-GBP1 nude mice group were higher than those in U87-Lacz nude mice group, and the proportions of MDSC in each tissue of U87-GBP1 + RS nude mice group and U87-Lacz + RS nude mice group were lower than those in the untreated by RS504393 corresponding nude mice group, and the differences were statistically significant (all P < 0.05). Conclusion:GBP1 might increase the expression of CCL2 in glioma U87 cells and recruit MDSC to form immunosuppression in glioma microenvironment, thus promoting the proliferation of glioma U87 cells in vivo.

Glioma is one of the most common primary tumors in the human brain with poor prognosis. The local and systemic immunosuppressive environment created by glioma cells enables them to evade immunosurveillance. Myeloid-derived suppressor cells (MDSCs) are a critical component of the immunosuppression system. They are a heterogeneous cell population composed of early myeloid progenitor cells and precursor cells. Although the cells are diverse in phenotypes and functions, they all have strong immunosuppressive functions. MDSCs are extensively infiltrated into tumor tissues and play an important role in the glioma immunosuppressive microenvironment, which also hinders the immunotherapeutic effects of glioma. This article will review the phenotypic characteristics of MDSCs in the glioma microenvironment and their role in the progression of glioma. It is of positive significance to better understand the pathogenesis of glioma and explore effective comprehensive treatments.
Glioma ; pathology ; Humans ; Immune Tolerance ; Myeloid-Derived Suppressor Cells ; cytology ; Tumor Microenvironment

Objective To understand the mutation characteristics of drug resistance-associated genes rpoB, katG and inhA in Mycobacterium tuberculosis (MTB) strains using gene chip method, and evaluate its clinical application value. Methods A total of 76 MTB strains were collected from Shijiazhuang area in 2013 to 2014. Gene chip was used to detect the mutations of rpoB, katG and inhA, and the L-J proportion drug susceptibility test was used as the gold standard to evaluate the overall concordance, sensitivity and specificity of gene chip. The consistency of microarray and phenotypic resistance was evaluated by Kappa test. Results Of all the 76 strains detected, 69 harbored mutations in katG/inhA. The predominant mutation site of katG was 315 codon with the mutation rate of 89.9%(62/69), and 5.8%(4/69) carried mutations at inhA-15(C→T), and 4.3%(3/69)carried combined mutations of katG 315 and inhA-15. The rpoB mutations were detected in 73 strains, of which 64.4%(47/73)carried mutations at codon 531, 15.1%(11/73)at codon 526, 12.3%(9/73)at 516 codon, 1.4%(1/73)at 513 codon, 1.4%(1/73)at 533 codon and 5.5%(4/73)had combined mutations. Compared with results from the L-J proportion method, the sensitivity, specificity and concordance rates of gene chip for RFP were 96.1%(73/76), 100%(50/50)and 97.6%(123/126). The sensitivity, specificity and concordance rates of gene chip for INH were 90.8%(69/76), 100%(50/50)and 94.4%(119/126). The sensitivity, specificity and concordance rates of gene chip for MDR-TB were 86.8%(66/76), 100%(50/50) and 92.1%(116/126). Conclusion The predominant mutation loci of MDR strains in Shijiazhuang area are katG315 and rpoB531. Gene chip is a fast and useful tool for clinical diagnosis of MDR strains.

0.05). The incidence of restenosis and major adverse cardiovascular events were significantly less in the hyperbaric oxygen group than that in the control group (6.67% vs 22.58% for restenosis, and 8.82% vs 38.24% for major adverse cardiovascular events; P0.05). No severe adverse effect was found during hyperbaric oxygen therapy in the hyperbaric oxygen group. Conclusion Hyperbaric oxygen therapy is effective and safe in preventing restenosis after intracoronary stenting.

OBJECTIVE:To prepare captopril hydrophilic gel sustained-release tablet and study the influencing factors on its release METHODS:With HPMC as the matrix,the tablets were prepared by direct compression method and influencing factors on release were studied RESULTS & CONCLUSION:The in vitro release of prepared tablets conformed to Higuchi equation The HPMC matrix tablet could release in a sustained way when the proportion of HPMC was at least 15% in weight and the best proportion was 60%;The dissolution of Methocel K was slower than 60RT or 75RT;Taking lactose as the filler was better than starch or CaSO4;When the proportion of lactose increased,the dissolution sharply decreased;The tablet dissolved more rapidly with paddle method than with rotating basket methos,compression force and pH of dissolution medium affected the release very little