1.Study of Single-cell Adhesion Kinetics by Fluidic Force Microscopy
Si-Ying QIN ; Tian-Qi YOU ; Tao XU ; Yan LUO ; Xi HU
Progress in Biochemistry and Biophysics 2026;53(7):2000-2014
ObjectiveCell adhesion is a critical process that regulates cellular physiological functions. Quantitative characterization of adhesion dynamics is essential for elucidating the intrinsic mechanical mechanisms underlying cellular activities. Although atomic force microscopy-based single-cell force spectroscopy is widely used for single-cell adhesion measurements, it requires complex chemical modifications for preparation of live-cell probes, leading to limitations such as cumbersome operation, low throughput, and potential impacts on cell viability. Fluidic force microscopy, which combines atomic force microscopy with microfluidic probes, is a technique allowing the operation of force-controlled nanopipettes in aqueous environments. By applying negative or positive pressure via a pressure controller, a single living cell can be captured onto or released from the cantilever under physiological conditions. This procedure offers a simple workflow and high assay throughput for single-cell adhesion measurements without the need for chemical functionalization. In this study, fluidic force microscopy-based single-cell force spectroscopy was adopted to achieve long-term quantitative characterization of single-cell adhesion dynamics in a simpler and more efficient manner, comparing the dynamic differences in adhesion establishment between two cell lines with different differentiation levels. MethodsHEK 293T and hTERT RPE-1 cells were non-invasively captured on the cantilever of a fluidic force microscope via its integrated microfluidic system during 40 h of adhesion culture. Cell-substrate detachment assays were performed, and force-distance curves were recorded to extract key mechanical adhesion parameters, including adhesion force, adhesion energy, and maximum detachment distance. These measurements were combined with real-time monitoring of cell spreading area to systematically characterize the dynamic evolution of single-cell adhesion. ResultshTERT RPE-1 cells rapidly entered a stable adhesion phase within 1 h after seeding, with both area-normalized adhesion force and area-normalized adhesion energy reaching peak values. In contrast, HEK 293T cells required 4 h to achieve stable adhesion. Subsequently, the adhesion force, adhesion energy and maximum detachment distance of hTERT RPE-1 and HEK 293T cells stabilized at approximately 240 nN vs. 30 nN, 2.2 pJ vs. 0.12 pJ and 6 μm vs. 4 μm, respectively. hTERT RPE-1 cells reached the peak of area-normalized adhesion parameters earlier than HEK 293T cells, with their peak area-normalized adhesion force and area-normalized adhesion energy being substantially elevated relative to HEK 293T cells. HEK 293T cells presented stronger linear correlations among adhesion energy, maximum detachment distance and adhesion force compared with hTERT RPE-1 cells. For both cell lines, cell spreading area exhibited a weak correlation with adhesion force. Whereas the area-normalized adhesion parameters of HEK 293T cells remained relatively constant throughout the adhesion process, hTERT RPE-1 cells exhibited elevated values in the early phase, followed by a gradual decline. These results indicated distinct dynamic adhesion patterns between the two cell types, with hTERT RPE-1 cells exhibiting stronger adhesion strength and higher adhesion efficiency. ConclusionIn this study, fluidic force microscopy-based single-cell force spectroscopy was successfully applied to perform long-term in situ quantitative measurement of the adhesion dynamics in single adherent cells. The approach revealed divergent adhesion patterns between HEK 293T and hTERT RPE-1 cells, suggesting a close association between cell differentiation and adhesion behaviors. These findings provide quantitative mechanical evidence for further understanding the underlying mechanisms of cell adhesion.
2.Comparison of the toxicity and safety of protein derivatives from novel fusion strains of Mycobacterium tuberculosis
Hao-qi XU ; Jiang-tao DONG ; Jie ZHANG ; Fang WU ; Su LIANG ; Xiao-ling LIU ; Lan-ru GAO ; Ju WANG ; Hui ZHANG ; Jiang-dong WU ; Le ZHANG ; Xi-ling DENG ; Wan-jiang ZHANG
Chinese Journal of Zoonoses 2025;41(4):376-384
The objective of this study was to evaluate the toxicity and safety of novel Mycobacterium tuberculosis fusion strain protein derivatives,referred to as B/R strain active proteins.In cellular experiments,RAW264.7 cells were treated with each vaccine preparation,and apoptosis rates were measured.In subsequent animal experiments,C57BL/6 mice were immunized via subcutaneous injection,and their survival and body weight changes were monitored and recorded at 2,4,8,12,and 16 weeks.The lungs and spleens were harvested to calculate organ coefficients,and pathological examinations were conducted.At the eighth week of immunization,the mice were infected with high concentrations of BCG,and pathological changes in the lungs and spleens were observed 4 weeks post-infection.The apoptosis rate at 6 hours was significantly higher in the experimental group than the PBS group(P<0.05).At 12 and 24 hours,the apoptosis rate in the experimental group remained higher than that in the PBS group,although this difference was not statistically significant.After immunization,mice in all four groups exhibited normal growth patterns,as indicated by stable body weight changes.At 4 and 12 weeks post-immunization,the lung coefficients in the protein group were significantly higher than those in the PBS group at the same time points.Additionally,the lung coefficients in the BCG group were significantly elevated across all time periods(P<0.05).The spleen coefficients in the protein and BCG groups were significantly higher than those in the PBS group at 2,4,8,12,and 16 weeks,whereas the ICD B/R group showed higher spleen coefficients than the PBS group only at week 8(P<0.05).Pathological examination revealed normal lung and spleen tissues in the PBS group.However,during the 2-8 weeks immunization period,lung and spleen tissues in all experimental groups exhibited varying degrees of damage,which gradually diminished by 12-16 weeks.Notably,no tuberculosis nodules were observed in any experimental group.After infection with high concentrations of BCG,no overt pathological changes were observed on the surfaces of the lungs and spleens in any group.Microscopic examination revealed less severe pathological changes in the lungs and spleens of mice in the experimental groups than the PBS group.Furthermore,no statistically significant differences were observed between the protein group and the BCG group.Our findings suggested that the B/R strain active proteins'toxicity and safety profiles were comparable to those of BCG,and showed immunoprotective effects.This study provides an experimental foundation for the development of a novel tuberculosis vaccine.
3.Effects of GGH genetic polymorphisms on serum concentrations and chemotherapy toxicities of methotrexate in children with intracranial tumors
Dan-qi ZHAO ; Zheng-yuan SHI ; Xi-qiao XU ; Shu-mei WANG
The Chinese Journal of Clinical Pharmacology 2025;41(2):183-187
Objective To investigate the effects of γ-glutamyl hydrolase(GGH)rs11545078 C>T polymorphisms on serum concentrations,chemotherapy toxicities of methotrexate(MTX),and prognosis in children with intracranial tumors.Methods Peripheral blood samples were obtained from children with intracranial tumors to extract genome DNA.Matrix-assisted laser desorption/ionization-time of flight mass spectrometry was used to detect the genotypes of GGH rs11545078 C>T polymorphisms.Fluorescence polarization immunoassay was employed to determine the serum concentrations of MTX.The incidences of toxicities,relapse,and metastasis were recorded after chemotherapy with MTX.The associations of GGH rs11545078 C>T polymorphisms with concentration-to-dose ratios(C/D ratios),chemotherapy toxicities of MTX,relapse,and metastasis of tumors were analyzed.Results A total of 75 children were included in the present study.The frequencies of rs11545078 CC and CT genotypes were 82.67%and 17.33%,respectively.The frequencies of C and T alleles were 91.33%and 8.67%,respectively.There were no statistically significant differences for these frequencies among the children with intracranial tumors,the children with acute lymphoblastic leukemia,and the health population in Beijing.Children with the CC genotype had higher median C/D ratios of MTX in 24 and 42 h(25.19 and 0.14 μmol·L-1 per g·m-2,respectively),higher metastasis rates(46.77%),and lower relapse rates(17.74%)than those in CT genotype carriers(22.01 and 0.11 μmol·L-1 per g·m-2,38.46%,and 30.77%,respectively),and the differences were no statistically significant(all P>0.05).The incidences of gastrointestinal disorders(76.92%)in children with the CT genotype were significantly higher than those in CC genotype carriers(45.16%,P<0.05).There were no statistically significant differences in the incidences of other adverse events between patients with the CC genotype and patients with the CT genotype(all P>0.05).Conclusion GGH rs11545078 CT might be a risk factor for gastrointestinal disorders in children with intracranial tumors treated with MTX.
4.Monte Carlo simulation study of the effect of filter on radiotherapy dosimetry in superficial X-ray therapy apparatus
Li TAO ; Hui ZHANG ; Yikai WU ; Junyi LIU ; Miao QI ; Ning GAO ; Yankui CHANG ; Xi PEI ; Zhi CHEN ; Xie XU
Chinese Journal of Radiological Medicine and Protection 2025;45(3):194-201
Objective:To explore the dosimetry optimization strategy based on filter thickness and shape selection for the bulb superficial X-ray radiotherapy unit.Methods:Monte Carlo code TOPAS was used to model tubular equipment, and the dose distribution from six X-ray energies (50-150 kV) and five conventional aluminum filters (0.5-3.0 mm) with different thickness were simulated in the water model. The percentage depth dose (PDD) curve along the central axis, the center-axis profile dose at different depths, and the lateral dose distribution were analyzed. The dose distribution of three different designs of aluminum filters (conventional cylindrical, conical and oblique cylindrical filters) was compared to evaluate the effect of dosimetric optimization of different filter shapes.Results:Under the same energy, increasing the thickness of the filter can optimize the superficial skin dose, and the optimization effect of depth dose uniformity can be increased by 26% at a depth of 5.5 mm at 70 kV energy. The raised, flat and inclined dose distribution modes can be achieved by using conventional cylindrical, conical and inclined aluminum filters.Conclusions:By selecting the appropriate X-ray energy and filter thickness, an ideal dose distribution matching the tumor depth can be achieved. The application of personalized filters is also of great significance for diverse target areas.
5.Treatment plan optimization for intensity-modulated brachytherapy based on the conjugate gradient algorithm
Miao QI ; Junyi LIU ; Shijun LI ; Yankui CHANG ; Jieping ZHOU ; Bing YAN ; Yong CHENG ; Aidong WU ; Xi PEI ; Xie XU
Chinese Journal of Radiological Medicine and Protection 2025;45(1):56-62
Objective:To investigate the application of the conjugate gradient (CG) algorithm to treatment plan optimization for intensity-modulated brachytherapy (IMBT).Methods:The general Monte Carlo software TOPAS was utilized to simulate the 192Ir source of IMBT, and the unit dose contribution matrix was calculated. An objective function was established using the weighted least squares method and was solved using the CG algorithm to achieve optimized IMBT treatment plans. The optimization was validated using five clinical cervical cancer cases under modulation width 60°. The dose distributions of IMBT treatment plans under 45°, 60°, 90°, 120°, and 180° modulation widths were compared using the Wilcoxon test to determine the optimal IMBT treatment plan for cervical cancer treatment. Results:The CG algorithm successfully optimized IMBT treatment plans under modulation width 60° for five cases within 22.2 s on average. On the premise of sufficient target dose coverage, the average D2 cm 3 values of the bladder and rectum in IMBT treatment plans were 3.66 and 1.97 Gy, respectively, representing reductions of 0.54 and 0.69 Gy compared to traditional brachytherapy plans. For the five modulation widths, the D90% values of all IMBT treatment plans reached 6 Gy, without statistically significant differences ( P > 0.05). The average D2 cm 3 values of the bladder in IMBT treatment plans were significantly lower than those in the traditional brachytherapy plans( P<0.05), with modulation width 60° associated with the greatest reduction of 0.61 Gy. In contrast, the average D2 cm 3 values of the rectum under 45°, 60°, and 90° modulation widths decreased by 0.63, 0.54, and 0.45 Gy, respectively, compared to traditional plans, with statistically significant differences( P<0.05). Conclusions:The CG method enables rapid achievement of optimized IMBT treatment plans that meet clinical requirements, and modulation width 60° contributes to valid dosimetric optimization. This study can serve as a guide for the clinical implementation of IMBT.
6.Application of the ArcherQA 3D dosimetric verification system in dosimetric verification of VMAT plans
Jieping ZHOU ; Ning GAO ; Zhongyu QI ; Qiang REN ; Xi PEI ; Xie XU ; Aidong WU
Chinese Journal of Radiological Medicine and Protection 2025;45(6):551-557
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.
7.Clinical and genetic characteristics of SCN2A gene related developmental delay
Jialu GU ; Shaofang SHANGGUAN ; Jianhong WANG ; Jiayi LI ; Hua XIE ; Xia QU ; Nan PENG ; Xi WANG ; Qi XU ; Yike ZHU ; Xinghui LI ; Xuefeng SUN ; Xiaoli CHEN ; Lin WANG
Chinese Journal of Preventive Medicine 2025;59(5):667-676
Objective:To explore the genotype and the clinical phenotype of SCN2A-related developmental delay in children. Methods:A case series study was adopted. Collect clinical data from 10 cases of children with SCN2A gene variants diagnosed with global developmental delay/intellectual disability who were admitted to the Children′s Hospital between July 2019 and March 2023. Summarize the clinical phenotype and genotype based on clinical data such as general information, clinical manifestations, imaging examinations, laboratory tests, genetic testing results, and comprehensive pediatric neuropsychological development assessment. Results:A total of 10 patients were recruited, including 7 males and 3 females, with an age range of 27 days to 5 years and 9 months. 9 patients underwent children′s neuropsychological and behavioral assessments, and the results were consistent with global developmental delay, including 2 mild cases, 4 moderate cases, and 3 severe cases. 3 cases had autism spectrum disorder, and 2 cases had epilepsy. 6 patients underwent complete head MRI examination, and 4 of them showed abnormalities, including delayed myelination, widening of the local extra brain space in the frontal lobe, and abnormal frontal lobe morphology. All 10 cases had point variants. Among them, 9 cases are de novo and 1 case is maternal inheritance. Out of 10 cases, there were 5 cases with copy number variations, but all of them were of unknown significance. Among the 10 variants, 8 have been reported and 2 have not been reported, namely c.4145A>T(p.N1382I) and c.4937T>A(p.I1646N). In this study, 4 out of 10 patients with SCN2A variants had variation sites located in the S4 segment of domain which constitute Nav1.2, the sodium ion channel encoded by SCN2A. The developmental quotient level was lower when the variation sites were located in the S4 segment of domain, and the difference was statistically significant ( t=-3.101, P=0.017), indicating that the severity of developmental delay may be related to the localization of amino acids corresponding to variant sites within the protein domain. Conclusion:SCN2A mutations are strongly associated with diverse neurodevelopmental disorders. In this study, the phenotypic spectrum of SCN2A variants encompassed epilepsy, global developmental delay, and autism spectrum disorder. Affected individuals exhibited early-onset developmental delays, predominantly moderate to severe in severity. Voltage-sensing domain dysfunction in sodium channels may constitute a critical pathomechanism underlying neurodevelopmental impairments. Further electrophysiological characterization and molecular mechanistic studies are warranted todelineate the genotype-phenotype correlations between specific variant loci and clinical severity.
8.Expert Consensus on the Ethical Requirements for Generative AI-Assisted Academic Writing
You-Quan BU ; Yong-Fu CAO ; Zeng-Yi CHANG ; Hong-Yu CHEN ; Xiao-Wei CHEN ; Yuan-Yuan CHEN ; Zhu-Cheng CHEN ; Rui DENG ; Jie DING ; Zhong-Kai FAN ; Guo-Quan GAO ; Xu GAO ; Lan HU ; Xiao-Qing HU ; Hong-Ti JIA ; Ying KONG ; En-Min LI ; Ling LI ; Yu-Hua LI ; Jun-Rong LIU ; Zhi-Qiang LIU ; Ya-Ping LUO ; Xue-Mei LV ; Yan-Xi PEI ; Xiao-Zhong PENG ; Qi-Qun TANG ; You WAN ; Yong WANG ; Ming-Xu WANG ; Xian WANG ; Guang-Kuan XIE ; Jun XIE ; Xiao-Hua YAN ; Mei YIN ; Zhong-Shan YU ; Chun-Yan ZHOU ; Rui-Fang ZHU
Chinese Journal of Biochemistry and Molecular Biology 2025;41(6):826-832
With the rapid development of generative artificial intelligence(GAI)technologies,their widespread application in academic research and writing is continuously expanding the boundaries of sci-entific inquiry.However,this trend has also raised a series of ethical and regulatory challenges,inclu-ding issues related to authorship,content authenticity,citation accuracy,and accountability.In light of the growing involvement of AI in generating academic content,establishing an open,controllable,and trustworthy ethical governance framework has become a key task for safeguarding research integrity and maintaining trust within the academic community.This expert consensus outlines ethical requirements across key stages of AI-assisted academic writing-including topic selection,data management,citation practices,and authorship attribution.It aims to clarify the boundaries and ethical obligations surrounding AI use in academic writing,ensuring that technological tools enhance efficiency without compromising in-tegrity.The goal is to provide guidance and institutional support for building a responsible and sustainable research ecosystem.
9.Monte Carlo study of transmission X-ray tubes in kilovoltage radiotherapy
Yikai WU ; Zhongyu QI ; Li TAO ; Hui ZHANG ; Zeeshan MUHAMMAD ; Zirui YE ; Yankui CHANG ; Xi PEI ; Xu GEORGE
Chinese Journal of Medical Physics 2025;42(7):863-871
Transmission X-ray tubes are relatively new devices characterized by portability,suitability for miniaturization,and low requirements for shielding,making them ideal radiation sources for kilovoltage X-ray therapy.However,their application in radiotherapy remains underexplored.An electron target model of a transmission X-ray tube is developed using the Monte Carlo toolkit TOPAS 3.8.1.The study investigates the effect of tungsten target thickness on X-ray output efficiency,finding that a tube voltage of 50 kV and a tungsten thickness of 1.4 μm yields the highest emission efficiency.Based on the energy spectrum at this optimal efficiency,polynomial fitting approach is applied to determine the corresponding aluminum filter thickness for mean energies ranging from 20 keV to 35 keV,achieving a mean fitting error of 0.91%.Next,the study simulates dose deposition in a water phantom for spectra with different mean energies and various source-to-surface distances,and plots percent-depth-dose curves,relative normalized dose-depth curves,and relative normalized dose histograms under each treatment condition.Finally,the simulated results are compared with experimental data from the intraoperative radiotherapy system Intrabeam and the superficial X-ray therapy unit SRT-100,obtaining average relative errors of 3.71%and 4.38%,respectively.These findings provide a theoretical foundation for further optimization of transmission X-ray tubes in kilovoltage radiotherapy.
10.Histaminergic Innervation of the Ventral Anterior Thalamic Nucleus Alleviates Motor Deficits in a 6-OHDA-Induced Rat Model of Parkinson's Disease.
Han-Ting XU ; Xiao-Ya XI ; Shuang ZHOU ; Yun-Yong XIE ; Zhi-San CUI ; Bei-Bei ZHANG ; Shu-Tao XIE ; Hong-Zhao LI ; Qi-Peng ZHANG ; Yang PAN ; Xiao-Yang ZHANG ; Jing-Ning ZHU
Neuroscience Bulletin 2025;41(4):551-568
The ventral anterior (VA) nucleus of the thalamus is a major target of the basal ganglia and is closely associated with the pathogenesis of Parkinson's disease (PD). Notably, the VA receives direct innervation from the hypothalamic histaminergic system. However, its role in PD remains unknown. Here, we assessed the contribution of histamine to VA neuronal activity and PD motor deficits. Functional magnetic resonance imaging showed reduced VA activity in PD patients. Optogenetic activation of VA neurons or histaminergic afferents significantly alleviated motor deficits in 6-OHDA-induced PD rats. Furthermore, histamine excited VA neurons via H1 and H2 receptors and their coupled hyperpolarization-activated cyclic nucleotide-gated channels, inward-rectifier K+ channels, or Ca2+-activated K+ channels. These results demonstrate that histaminergic afferents actively compensate for Parkinsonian motor deficits by biasing VA activity. These findings suggest that targeting VA histamine receptors and downstream ion channels may be a potential therapeutic strategy for PD motor dysfunction.
Animals
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Histamine/metabolism*
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Male
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Oxidopamine/toxicity*
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Rats
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Ventral Thalamic Nuclei/physiopathology*
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Rats, Sprague-Dawley
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Disease Models, Animal
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Parkinson Disease/metabolism*
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Neurons/physiology*
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Humans
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Optogenetics

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