In-depth study of the components of polymyxins is the key to controlling the quality of this class of antibiotics.Similarities and variations of components present significant analytical challenges.A two-dimensional(2D)liquid chromatography-mass spectrometry(LC-MS)method was established for screening and comprehensive profiling of compositions of the antibiotic colistimethate sodium(CMS).A high concentration of phosphate buffer mobile phase was used in the first-dimensional LC system to get the components well separated.For efficient and high-accuracy screening of CMS,a targeted method based on a self-constructed high resolution(HR)mass spectrum database of CMS components was established.The database was built based on the commercial MassHunter Personal Compound Database and Library(PCDL)software and its accuracy of the compound matching result was verified with six known components before being applied to genuine sample screening.On this basis,the unknown peaks in the CMS chromatograms were deduced and assigned.The molecular formula,group composition,and origins of a total of 99 compounds,of which the combined area percentage accounted for more than 95％of CMS components,were deduced by this 2D-LC-MS method combined with the MassHunter PCDL.This profiling method was highly efficient and could distinguish hundreds of components within 3 h,providing reliable results for quality control of this kind of complex drugs.

Background: The global rise in visual impairment, driven by population aging, the increasing prevalence of lifestyle-related chronic diseases, and environmental factors, has made it a critical public health concern, highlighting the urgent need for effective preventive strategies and eye health maintenance. Cuscutae Semen (CS), a traditional Chinese herbal medicine long regarded for its vision-enhancing properties, has been widely used to support ocular health. However, its underlying molecular mechanisms and bioactive constituents remain poorly understood, limiting its modernization and broader clinical application. Objective: This study aims to investigate the restorative effects of CS on visual impairment, elucidate its underlying mechanisms, and identify potential active components. Methods: A zebrafish model of visual impairment was established using mepanipyrim to simulate retinal structural damage and visual dysfunction. The therapeutic effects of CS were systematically evaluated through behavioral analyses and histomorphological observations. To elucidate the underlying mechanisms, an integrated approach was employed, combining transcriptome sequencing (RNA-seq), reverse transcription quantitative polymerase chain reaction validation, and immunofluorescence staining to identify critical genes and pathways involved. Furthermore, macroporous resin column chromatography was employed for the fractionation and screening of potential active components. Results: CS treatment significantly alleviated mepanipyrim-induced ocular abnormalities in zebrafish, restoring approximately 82% of the observed morphological defects. Behavioral assessments revealed that CS-treated zebrafish exhibited markedly increased swimming speed and distance, indicating enhanced visual light sensitivity. Histopathological analysis demonstrated that CS effectively repaired the structure of retinal cell layers. RNA-seq revealed that CS broadly reversed mepanipyrim-induced gene expression disturbances, suggesting a restorative effect on transcriptomic homeostasis. Gene Ontology enrichment analysis identified the phototransduction pathway as a key mediator of CS’s therapeutic effects. This was further supported by reverse transcription quantitative polymerase chain reaction validation of critical genes and immunofluorescence staining, which confirmed the restored expression of Pde6a and Gnat2, key proteins involved in photic signal transmission. Active component screening indicated that high-polar constituents, including chlorogenic acid, may constitute one of the major bioactive fractions responsible for the observed therapeutic effects. Conclusion: This study provides evidence of the vision-protective effects of CS in a zebrafish model, demonstrating that its therapeutic mechanism involves modulation of the phototransduction pathway. Chlorogenic acid was identified as one of the key bioactive constituents contributing to this effect. These findings not only provide scientific validation for the traditional use of CS in ocular protection but also present promising therapeutic prospects for the prevention and treatment of visual impairment.

Ultra-high dose-rate (FLASH) radiotherapy is a new mode of radiotherapy that can control tumors while significantly reducing damage to surrounding normal tissues. Since its official naming in 2014, FLASH radiotherapy research has continued to grow, and in 2019 it entered a period of exponential development. Studies have shown that electrons, photons, and protons can all induce the FLASH effect, but the proton beam can overcome the physical limitations of shallow incident depth and high penetration dose, which is considered to be the most effective solution. This article summarizes previous research results of FLASH proton therapy from the research at the cell, animal and clinical levels, and summarizes the hypothesis of the FLASH effect mechanism, aiming to provide reference for promoting the research and clinical transformation of FLASH proton therapy.

Objective:To compare the relative proportion of direct action (ray particles directly destroy biological molecules such as DNA and indirect action (radical-mediated oxidative damage) in the damage caused by X-ray and proton irradiation of lung cancer cells.Methods:Unirradiated human lung adenocarcinoma A549 cells and human large cell lung cancer NCI-H460 cells were cultured in media containing 0, 0.125, 0.25, 0.5, 0.75 mol/L dimethyl sulfoxide (DMSO) for 1 h to obtain plating efficiency (PE) values, thereby determining whether DMSO affected cell survival. Following pretreatment with each DMSO concentration, cells were exposed to X-ray irradiation at physical doses of 2, 4, 6, 8 Gy and proton irradiation at equivalent doses of 2, 4, 6, 8 GyE, respectively. Survival fractions (SF) and maximum protection (MP) values were calculated to evaluate the effects of varying DMSO concentrations on post-irradiation cell survival and to quantify the contribution of indirect radiation damage mechanisms (higher MP indicates greater indirect effect contribution). PE, SF, and MP values were determined using clonogenic assays. Comparisons among multiple groups were performed using one-way ANOVA followed by Tukey's multiple comparison, and comparisons between irradiation groups were analyzed using independent samples t-tests. Results:The PE of unirradiated cells treated with varying DMSO concentrations showed no statistically significant differences. Following pretreatment at different DMSO concentrations and subsequent irradiation with X-rays or protons, the protective effect of DMSO reached saturation at 0.5 mol/L. At this concentration, comparison of the average MP values across 4 radiation doses revealed: In A549 cells, the MP value was 54.21%±1.73% for X-ray irradiation group and 39.69%±0.72% for proton irradiation group ( t=16.82, P<0.001); in NCI-H460 cells, the MP value was 52.04%±1.00% for X-ray irradiation group and 41.31%±0.70% for proton irradiation group ( t=10.19, P<0.001). Conclusions:Under biologically equivalent doses, proton irradiation demonstrates greater reliance on direct effects in lung cancer cells killing compared with X-ray irradiation.

AIM:To determine the concentration of ARV-471(a representative PROTAC drug)in mice plasma by establishing an HPLC-MS/MS method and to apply this method in pharmacokinetic studies in mice.METHODS:Verapamil was taken as the inter-nal standard,the mice plasma samples were extract-ed by methanol.After centrifugation,the superna-tant was analyzed by liquid chromatography-mass spectroscopy(LC-MS/MS).Chromatographic col-umn:ACQUITY UPLC HSS T3(1.8 μm,2.1 mm × 50 mm);The mobile phase consists of acetonitrile(containing 0.1％formic acid)and 2 mmol/L ammoni-um formate aqueous solution(containing 0.1％for-mic acid)for gradient elution;flow-rate of 0.6 mL/min;injection volume:2 μL.The electrospray ioniza-tion(ESI)is employed,operating in positive ion scan-ning mode with multiple reaction monitoring(MRM)detection.The specificity,standard curve and quanti-fication limit,precision and accuracy,recovery rate and matrix effect,stability and dilution reliability of this method were examined.Furthermore,the plas-ma concentration and pharmacokinetic parameters of ARV-471 in mice after intravenous injection of 5 mg/kg and oral gavage of 30 mg/kg were deter-mined and calculated.RESULTS:The results dem-onstrate that ARV-471 exhibits a good linear rela-tionship within the concentration range of 2.0 to 2 000.0 ng/mL.The intra-and inter-accuracy were between 80.0％and 120.0％,with the intra-and in-ter-precision less than 15％.The results of method-ological study of specificity,matrix effect,stability conformed to the requirements of the guideline.Pharmacokinetic parameters reveal that after oral administration of 30 mg/kg ARV-471 to male and fe-male mice,Cmax were(2 947.19±454.77)and(2 682.02±342.23)ng·mL-1;AUC0-twere(23 357.37±3 488.00)and(20 161.23±1 871.32)ng·h·mL-1;T1/2were(3.11±0.18)and(2.93±0.62)h.Tmax were(1.83±0.41)and(2.00±0.00)h for male and fe-male mice,respectively.After intravenous adminis-tration of 5 mg/kg ARV-471 to male and female mice,the AUC0-t values were found to be(18 219.07±2 059.41)and(17 238.01±2 380.55)ng·h·mL-1;T1/2 values were(2.76±0.23)and(2.73±0.20)h;The absolute bio-availability of ARV-471 were deter-mined to be(19.49±1.81)％and(21.37±3.19)％for male and female mice,respectively.CONCLU-SION:This study establishes a rapid and effective method for the pharmacokinetic research of ARV-471,laying the foundation for the pharmacokinetic studies of PROTAC drugs.

Poly(lactic-co-glycolide)(PLGA)is a key excipient in long-acting sustained-release preparations,and its degradation properties directly affect the drug release behavior.In this study,PLGA microspheres were prepared by microfluidic techniques,and the morphology changes of the microspheres were observed by scanning electron microscopy(SEM).In alkaline environment,due to the accelerated hydrolysis of ester bonds,the surface of the microspheres was rapidly dissolved and eroded,and the degradation rate was significantly higher than that in acidic environment.High temperature accelerated the degradation of PLGA microspheres.Under neutral and alkaline conditions,the microspheres showed aggregation and adhesion.Under acidic conditions,the microspheres gradually decomposed into irregular fragments.The high ionic strength further promoted the surface corrosion of the microspheres,especially under extreme pH conditions.Simultaneously,PLGA microspheres encapsulating coumarin were prepared to simulate the microsphere formulation.The release rate of coumarin after degradation of the microspheres under different conditions was observed by measuring the absorbance with ultraviolet-visible spectrophotometry.The results were consistent with those of the blank microspheres.This study revealed that the degradation of PLGA microspheres was significantly pH-dependent,temperature sensitive and ion strength responsive.These findings not only helped to understand and optimize the long-term stability and controlled release performance of drug-carrying microspheres,but also provided a theoretical basis for further improvement of PLGA-based drug carrier design.

Ketamine is a dissociative anesthetic.It is clinically used as a surgical anesthetic or anes-thetic inducer and has a certain degree of mental dependence.Its abuse can lead to nerve damage,ad-verse emotional reactions and other toxic side effects.The primary mechanism by which ketamine exerts its pharmacological effects is to block N-methyl-D-aspartate receptors(NMDAR).It also functions through pathways such as α-amino-3-hydroxy-5-methyl-4-isox-azolepropionic acid receptors(AMPAR),opioid receptors,γ-aminobutyric acid(GABA)receptors,monoaminergic receptors,cholinergic recep-tors,hyperpolarization-activated cyclic nucleotide-gated(HCN)channels,voltage-gated sodium channels,and L-type voltage-dependent calcium channels(VDCC).This article summarizes the molecular mecha-nism and toxic effects of ketamine's pharmacological functions,in order to provide a basis for foren-sic applications such as the identification of symptomatic phenotypes of ketamine toxic effects and the identification of ketamine abuse.

Objective:To evaluate the clinical effect of temporomandibular joint disc anchoring and deviated jaw splint in the treatment of adolescent patients with mandibular deviation deformity complicated with anterior disc displacement of temporomandibular joint.Methods:A total of 30 patients with mandibular deviation deformity complicated with anterior disc displacement of temporomandibular joint who were treated in the Suzhou Municipal Hospital from January 2020 to March 2023 were prospectively selected. Among them, 10 patients in the surgical splint group received temporomandibular joint disc anchoring combined with sequential treatment of deviated jaw splint; 20 patients in the splint group received deviated jaw splint treatment. The improvement of facial deviation before and after treatment was compared between the two groups, and magnetic resonance imaging (MRI) was used to evaluate the stability of temporomandibular joint disc position and the change of condylar height.Results:After treatment, the midfacial line deviation was (1.3±0.3)mm and the condylar height was (21.5±0.6)mm in the surgical splint group; in the splint group, the midfacial line deviation was (1.5±0.4)mm and the condylar height was (21.6±0.7)mm. Both facial deviation and condylar height in the two groups were significantly improved compared with those before treatment (all P<0.01). During the treatment course, MRI was taken every 3 months in both groups. The stability rate of the joint disc in the surgical splint group was 100%(10/10), and that in the splint group was 90.0%(18/20). Conclusions:The application of temporomandibular joint disc anchoring combined with sequential treatment of deviated jaw splint in adolescent patients with mandibular deviation deformity complicated with anterior disc displacement of temporomandibular joint can achieve good clinical effects. The position of the temporomandibular joint disc remains stable before and after treatment, and new bone formation occurs in the condyle.

In-depth study of the components of polymyxins is the key to controlling the quality of this class of antibiotics. Similarities and variations of components present significant analytical challenges. A two-dimensional (2D) liquid chromatography-mass spectrometr (LC-MS) method was established for screening and comprehensive profiling of compositions of the antibiotic colistimethate sodium (CMS). A high concentration of phosphate buffer mobile phase was used in the first-dimensional LC system to get the components well separated. For efficient and high-accuracy screening of CMS, a targeted method based on a self-constructed high resolution (HR) mass spectrum database of CMS components was established. The database was built based on the commercial MassHunter Personal Compound Database and Library (PCDL) software and its accuracy of the compound matching result was verified with six known components before being applied to genuine sample screening. On this basis, the unknown peaks in the CMS chromatograms were deduced and assigned. The molecular formula, group composition, and origins of a total of 99 compounds, of which the combined area percentage accounted for more than 95% of CMS components, were deduced by this 2D-LC-MS method combined with the MassHunter PCDL. This profiling method was highly efficient and could distinguish hundreds of components within 3 h, providing reliable results for quality control of this kind of complex drugs.