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.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.
3.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.
4.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.
5.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.
6.Progress in Methods for Electrochemical Detection of Thrombin
Di WU ; Xi-Yao ZHANG ; Jing-Jing XU ; Yi-Ting CHEN ; Wen-Qi TANG ; Wen-Hui XU ; Song-Min CHEN ; Qiong HU ; Li NIU
Chinese Journal of Analytical Chemistry 2025;53(9):1403-1410
As a serine protease,thrombin can convert soluble fibrinogen into insoluble fibrin and plays a pivotal role in the coagulation cascade.Therefore,the accurate quantitative assay of thrombin levels is of great value in the evaluation of coagulation function,clinical screening and prognostic monitoring of coagulation-related diseases,and screening of drugs for targeted therapy.Existing methods for thrombin detection can be divided into two categories,e.g.,the assay of concentration levels using nucleic acid aptamers as the affinity elements and the assay of activity levels based on the hydrolytic cleavage of substrate peptides.In recent years,electrochemical biosensors have attracted much attention in thrombin detection due to high sensitivity,high selectivity,simple instrument,fast response,and good portability.In this review,the latest research progress in methods for electrochemical detection of thrombin was summarized,focusing on the detection principles and the applied signal amplification strategies of related electrochemical biosensors.In addition,the challenges with respect to the practical use of electrochemical thrombin biosensors and the prospects were discussed.
7.Effects of MTHFR and GGH gene polymorphisms on plasma concentrations and toxicity following high-dose methotrexate therapy in children with acute lymphoblastic leukemia.
Lin-Xiao TENG ; Qi AN ; Lei WANG ; Nan WANG ; Qing-Ling KONG ; Rui HAN ; Yuan WANG ; Lu LIU ; Yan WANG ; Shu-Mei XU ; Kun-Peng SHI ; Fang-Shan QIU ; Xi-Xi DU ; Jin-Rui SHI
Chinese Journal of Contemporary Pediatrics 2025;27(7):802-807
OBJECTIVES:
To investigate the effects of methylenetetrahydrofolate reductase (MTHFR) rs1801133 and γ-glutamyl hydrolase (GGH) rs11545078 gene polymorphisms on plasma concentrations and toxicity following high-dose methotrexate (MTX) therapy in children with acute lymphoblastic leukemia (ALL).
METHODS:
Children with ALL treated at the Xuzhou Children's Hospital of Xuzhou Medical University from January 2021 to April 2024 were selected for this study. Genotypes of MTHFR rs1801133 and GGH rs11545078 were determined using multiplex polymerase chain reaction. MTX plasma concentrations were measured by enzyme-multiplied immunoassay technique, and toxicity was graded according to the Common Terminology Criteria for Adverse Events version 5.0. The relationships between MTHFR rs1801133 and GGH rs11545078 genotypes and both MTX plasma concentrations and associated toxicities were analyzed.
RESULTS:
In the low-risk ALL group, the MTHFR rs1801133 genotype was associated with increased MTX plasma concentrations at 72 hours (P<0.05). In the intermediate- to high-risk group, the MTHFR rs1801133 genotype was associated with increased MTX plasma concentrations at 48 hours (P<0.05), and the GGH rs11545078 genotype was associated with increased MTX plasma concentrations at 48 hours (P<0.05). In the intermediate- to high-risk group, the MTHFR rs1801133 genotype was associated with the occurrence of reduced hemoglobin (P<0.05), and the GGH rs11545078 genotype was associated with the occurrence of thrombocytopenia (P<0.05).
CONCLUSIONS
Detection of MTHFR rs1801133 and GGH rs11545078 genotypes can be used to predict increased MTX plasma concentrations and the occurrence of toxic reactions in high-dose MTX treatment of ALL, enabling timely interventions to enhance safety.
Humans
;
Methotrexate/toxicity*
;
Methylenetetrahydrofolate Reductase (NADPH2)/genetics*
;
Precursor Cell Lymphoblastic Leukemia-Lymphoma/blood*
;
Male
;
Female
;
Child
;
Child, Preschool
;
gamma-Glutamyl Hydrolase/genetics*
;
Antimetabolites, Antineoplastic/adverse effects*
;
Infant
;
Polymorphism, Genetic
;
Adolescent
;
Genotype
;
Polymorphism, Single Nucleotide
8.Clinical and genetic analysis of a patient with FSIP2 compound heterozygous variants causing multiple morphological abnormalities of sperm flagella.
Yao-Qi CHEN ; Li-Qi XU ; Yi-Bo DAI ; Liang-Yu YAO ; Shen-Ming YANG ; Lu-Yu HUANG ; Xi YANG ; Yi YU ; Jing-Ming YANG ; Ke-Rong WU
National Journal of Andrology 2025;31(5):395-402
OBJECTIVE:
The aim of this study is to analyze the clinical features and genetic etiology of a patient with multiple morphological abnormalities of the sperm flagella (MMAF) retrospectively.
METHODS:
A severely oligospermic patient from the Reproductive Center of the First Affiliated Hospital of Ningbo University was selected as the study subject. Clinical data and examination results were collected. High-throughput sequencing and bioinformatics were used to analyze the genetic etiology. And Sanger sequencing was employed to validate findings in the family. Transmission electron microscopy (TEM) was used to observe the sperm ultrastructure, and immunofluorescence analysis was performed to examine the localization of FSIP2 protein in the sperm.
RESULTS:
The patient presented with severe oligospermia, and sperm morphology displayed MMAF. TEM revealed fibrous sheath and 9+2 microtubule structural disruptions in the sperm. Sequencing identified compound heterozygous variants in the FSIP2 gene (c.17798C > T, c.5927T > G), inherited from the father and mother, respectively. According to the guidelines of the American College of Medical Genetics and Genomics, the variants were classified as pathogenic. The patient's spouse underwent intracytoplasmic single sperm injection, resulting in one embryo, but no clinical pregnancy occurred after embryo transfer.
CONCLUSION
This study reported the mutation of FSIP2 gene c.17798C > T, c.5927T > G in a patient with MMAF. These findings expand the mutational spectrum of the FSIP2 gene and provide insights for genetic and assisted reproductive counseling for patients with MMAF.
Humans
;
Male
;
Sperm Tail/pathology*
;
Heterozygote
;
Oligospermia/genetics*
;
Spermatozoa
;
Mutation
;
Infertility, Male/genetics*
;
Adult
;
Pedigree
;
Retrospective Studies
;
Sperm Injections, Intracytoplasmic
9.Evaluation of inner ear malformation based on high-resolution CT and MRI.
Liangliang LIU ; Kung ZHANG ; Bing WANG ; Qi YANG ; Lei XU ; Yan HAO ; Hui XU
Journal of Clinical Otorhinolaryngology Head and Neck Surgery 2025;39(1):47-56
Objective:To explore the value of high resolution computed tomography(HRCT) combined with Magnetic Resonance Imaging(MRI) in the diagnosis of inner ear malformation. Methods:HRCT and MRI data of 82 patients with inner ear malformations were analyzed retrospectively. HRCT MPR and CPR reconstruction of the inner ear structure, facial nerve canal and oblique sagittal MRI reconstruction of the internal auditory canal were performed. The inner ear malformations were classified, the conditions of facial nerve canal and cochlear nerve were evaluated. The association between inner ear malformation and cochlear nerve dysplasia were analyzed by Chi-square test with continuity correction. Results:Among the 82 patients with inner ear malformations,there were 49 cases of bilateral symmetry, 11 cases of bilateral asymmetry and 22 cases of unilateral inner ear malformations. Respectively, the most prevalent types were IP-Ⅱ(42.96%), dilatation of atrium aqueduct(18.31%) and malformations of atrium and semicircular canal 19.72%. Out of 50 cases of cochlear malformations,only 3 were isolated cochlear malformations, and the rest were accompanied by other malformations of varying degrees. In the 67 ears examined by MRI, 26(38.81%) had cochlear nerve deficiency(CND), and the incidence of CND varied with different types of inner ear malformations. Out of 142 ears, 28(19.72%) had abnormalities of the facial nerve canal. Conclusion:HRCT combined with MRI can accurately distinguish the types of inner ear malformation and effectively evaluate the facial nerve canal and cochlear nerve, and further provides the important finger and Guide value for the clinician to formulate the reasonable treatment and the operation plan.
Humans
;
Ear, Inner/diagnostic imaging*
;
Magnetic Resonance Imaging/methods*
;
Retrospective Studies
;
Female
;
Male
;
Tomography, X-Ray Computed/methods*
;
Child
;
Adolescent
;
Adult
;
Child, Preschool
;
Cochlear Nerve/diagnostic imaging*
;
Facial Nerve/abnormalities*
;
Cochlea/abnormalities*
;
Infant
;
Young Adult
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
;
Histamine/metabolism*
;
Male
;
Oxidopamine/toxicity*
;
Rats
;
Ventral Thalamic Nuclei/physiopathology*
;
Rats, Sprague-Dawley
;
Disease Models, Animal
;
Parkinson Disease/metabolism*
;
Neurons/physiology*
;
Humans
;
Optogenetics

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