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.

Objective To explore the efficacy of DSA-guided intrathecal drug delivery system combined with Zi Wu Liu Zhu Acupoint Therapy for management of cancer pain and provide reference for its standardized clinical application.Methods and Results Recommendations were formulated based on literature review and expert group discussion,and consensus was reached following expert consultation.The consensus recommendations are comprehensive,covering the entire treatment procedures from preoperative assessment and preparation,surgical operation process,postoperative management and traditional Chinese medicine treatment to individualized treatment planning.The study results showed that the treatment plans combining traditional Chinese with Western medicine effectively alleviated cancer pain,reduced the use of opioid drugs,and significantly improved the quality of life and enhanced immune function of the patients.Postoperative follow-up suggested good treatment tolerance among the patients without serious complications.Conclusion The formulated consensus is comprehensive and can provide reference for clinicians to use DSA-guided intrathecal drug delivery system combined with Zi Wu Liu Zhu Acupoint Therapy.The combined treatment has a high clinical value with a good safety profile for management of cancer pain.

Objective:To evaluate the design and application of the superior thyroid artery perforator flap (STAPF) for reconstruction after head and neck oncological resection.Methods:A retrospective analysis was performed on 24 consecutive patients (22 men, 2 women; age 40-72 years) treated at Hunan Cancer Hospital between June 2018 and December 2023. Their primary tumors included buccal carcinoma ( n=7), tongue carcinoma ( n=8), oropharyngeal carcinoma ( n=2), floor-of-mouth carcinoma ( n=3), laryngeal carcinoma ( n=3), and hypopharyngeal carcinoma ( n=1). Flap design, venous drainage strategy, and postoperative outcomes were assessed. SPSS 19.0 software was used for statistical analysis. Results:Flap dimensions were length of 9.4±0.5 cm, width of 3.3±0.6 cm, thickness of 0.5±0.2 cm, and pedicle length of 7.3±0.6 cm. Fifteen flaps were based on a single perforator (diameter ≥0.5 mm), whereas, nine fascial flaps incorporated multiple perforators (capillary diameter ≤0.5 mm). Venous drainage routes were as follows: superior thyroid vein ( n=12, retrograde in 3), facial vein ( n=5, all retrograde), anterior jugular vein ( n=4, retrograde in 1), and external jugular vein ( n=3, retrograde in 2). All 24 flaps survived completely. Donor sites were closed primarily and all cervical wounds healed. No flap-related complications, inculding orocutaneous, pharyngocutaneous, laryngocutaneous fistula and wound infection, were observed. Final pathologic stages were T1N0M0 ( n=2), T2N0M0 ( n=16), T2N1M0 ( n=3), and T3N0M0 ( n=3). With follow-up of 12-46 months, aside from one patient with tongue cancer died of contralateral cervical and parapharyngeal lymph-node metastases at 6 months, others remained disease-free. Patients with laryngeal or hypopharyngeal carcinoma had their tracheostomy tubes removed within 4 weeks postoperatively. Conclusion:STAPF offers flexible design, with minimal donor-site morbidity and low functional impairment. It is particularly advantageous for reconstruction of small-to-moderate defects following head and neck tumor ablation.

Objective To investigate the influence of helical tomographic radiotherapy plans with different combinations of lead gate width,pitch and algorithms on threading effects.Methods A target model was established with a Cheese Phantom used as the simulated human body,then three lead gate widths(1.0,2.5,and 5.0 cm),six screw pitches(0.143,0.172,0.215,0.287,0.430,and 0.500)and two computational grids(Fine algorithm and Normal algorithm)were respectively combined for designing the helical tomography radiotherapy plans.The radiotherapy plans with a pitch of 0.143,0.172,0.215,0.287 or 0.430 were enrolled into an experimental group,and the plans with a pitch of 0.500 were divided into a control group.The dosimetric parameters including maximum dose(Dmax),minimum dose(Dmin)and mean dose(Dmean)of the target area PTV1 and PTV2 were evaluated by the dose volume histogram(DVH).The dose homogeneity index(HI)of the target area was calculated,and the single rotation time and total treatment time of each plan were recorded and counted.SPSS 27.0 software was used for statistical analysis.Results No significant threading effect appeared regardless of the pitch value when the lead gate width was 1.0 cm.The threading effects in the experimental group were weaker than those in the control group when the lead gate width was 2.5 or 5.0 cm.The threading effect gradually rose with the pitch increased when the lead gate width was 5.0 cm.The most significant difference was found between the threading effect in case of the screw pitch being 0.500 and that with the screw pitch being 0.143,with the differenes being statistically obvious(P<0.05).The lead gate width had significant effects on the Dmax,Dmin,Dmean and HI of PTV1 and PTV2.When the lead gate width was 5.0 cm,high HI value and uneven dose distribution were detected and lowered screw pitch weakened the threading effect.The single rotation time first remained constant and then increased with the screw pitch was enlarged,with the changing points occurring in case of the screw pitches of 0.287 and 0.430.With a certain lead gate width,the treatment time for plans was shortened with the decrease of the pitches in case of the pritches lower than 0.287,and tended to be constant after the screw pitches reached 0.287.The changes of the computational grid had no significant effects on the results of radiotherapy plans when the lead gate width and screw pitch were kept constant.Conclusion When designing a spiral tomotherapy plan with conventional doses,a lead gate width of 1.0 or 2.5 cm and a screw pitch of 0.287 or 0.430 should be selected in order to minimize the threading effect while ensuring the efficiency of plan implementation.[Chinese Medical Equipment Journal,2025,46(8):58-66]

Objective To investigate the changes of residual radioactivity at different time points after 131I treatment in the patients with differentiated thyroid cancer(DTC)and influencing factors.Methods A to-tal of 235 patients with DTC receiving 131I treatment in this hospital from January 2021 to June 2023 were se-lected as the study subjects and divided into the high dose group(＞5.55 GBp,n=56)and low dose group(≤5.55 GBp,n=179)according to the treatment dose.The clinical data of the two groups were collected and the changes of residual radioactivity after 131I treatment were compared between the two groups.The binary re-gression was used to analyze its influencing factors.Results The sex,age,BMI,basic metabolic rate(BMR)and serum thyroglobulin antibody(TgAb)had no statistical differences between the two groups(P＞0.05).The proportions of serum thyroglobulin(TG)＜1 ng/mL,131I first time treatment and residual thyroid ratio prompted by the whole body 131I scan after treatment in the low dose group were significantly higher than those in the high dose group(P＜0.05).The residual radioactivity in the two groups was significantly de-creased with time extension.The residual radioactivity at 24,48,72 h after treatment in the low dose group was significantly lower than that in the high dose group(P＜0.05).The binary logistic regression analysis re-sults showed that the T stage and treatment dose were the influencing factors of residual radioactivity after 131I treatment.Conclusion The residual radioactivity after 131I treatment in the patients with DTC shows the significant decreasing trend with time extension,this change trend has an active significance for further opti-mizing and perfecting the isolation and protection scheme.For the patients with high T stage and big treat-ment dose,the isolation time should exceed 72 h.

Objective To establish a human monocytic THP-1 macrophage-derived foam cell model and analyze the role of the α subunit of coatomer protein Ⅰ(α-COP)in apolipoprotein A-1(apoA-1)-mediated cholesterol efflux from foam cells.Methods THP-1 cells were induced to adhere using PMA(PMA group),followed by treatment with acetylated low-density lipoprotein(Ac-LDL)to generate macrophage-derived foam cells(Ac-LDL group).Subsequent incubation with apoA-1 formed the apoA-1 group.Cholesterol efflux rates mediated by apoA-1 and intracellular lipid accumulation were quantified through liquid scintillation counting and oil red O staining.The expression patterns of α-COP were systematically analyzed using quantitative real-time PCR(qPCR),Western blotting,and laser scanning confocal microscopy.THP-1 macrophage-derived foam cells mediated by apoA-1 were transduced with scrambled shRNA(Scr group)or α-COP-specific shRNA lentivirus(α-COP shRNA group)to assess the effects of α-COP knockdown on cholesterol efflux efficiency and total cellular cholesterol content.Subcellular localization of adipopoilin(ADFP)and cholesterol probe Fil-ipin Ⅲ staining patterns were visualized via laser scanning confocal microscopy.Bioinformatics analysis of α-COP expression profiles in carotid atherosclerotic plaques was performed using datasets from the GEO data-base.Results Compared with the Ac-LDL group,the cholesterol efflux rate in the apoA-1 group was signifi-cantly increased[(9.77±0.79)%vs.(2.74±0.37)%,P＜0.001].Oil red O staining demonstrated reduced lipid accumulation in foam cells of the apoA-1 group compared with the Ac-LDL group.The relative mRNA expression level of α-COP in the apoA-1 group was significantly higher than that in the Ac-LDL group(P＜0.001),with corresponding elevation in protein expression(P＜0.001).Fluorescence intensity analysis re-vealed increased mean fluorescence intensity of α-COP in the apoA-1 group compared with the Ac-LDL group.Following α-COP knockdown by shRNA,the apoA-1-mediated cholesterol efflux rate was significantly de-creased(P＜0.05)and total intracellular cholesterol levels were increased(P＜0.001)in the α-COP shRNA group compared with the Scr group.The α-COP shRNA group exhibited enhanced red fluorescence intensity of ADFP(P＜0.05)and increased blue fluorescence intensity of Filipin Ⅲ(P＜0.01)compared with the Scr group.Database analysis indicated that α-COP mRNA expression was lower in carotid atherosclerotic plaques than in normal arterial tissues,with reduced expression in advanced-stage plaques compared with early-stage plaques(P＜0.05).Conclusion α-COP participates in apoA-1-mediated cholesterol efflux from foam cells,and interference with α-COP expression results in reduced cholesterol efflux and increased intracellular lipid accumulation.

OBJECTIVE To explore the relationship between cervical lymph node metastasis of thyroid cancer and ultrasound features,as well as BRAF V600E mutation.METHODS A retrospective study was conducted on 120 patients admitted to the First Affiliated Hospital of USTC,Division of Life Sciences and Medicine,University of Science and Technology of China between October 2022 and March 2023 to analyze the relationship between neck lymph node metastasis,ultrasound features,and BRAF V600E mutation.RESULTS A total of 120 thyroid cancer patients were included,with a lymph node metastasis rate of 60.00%(72/120)and a BRAF V600E mutation rate of 79.17%.There was no statistically significant difference between different BRAF V600E mutations and cervical lymph node metastasis(χ2=1.895,P=0.169).More than 1 aspect ratio,multiple lesions,calcification,rich blood flow,and lesion diameter≥1 cm are risk factors for lymph node metastasis(OR=3.448,P=0.009;OR=3.758,P=0.008;OR=2.834,P=0.047;OR=3.552,P=0.024;OR=3.521,P=0.031),Age>40 years old is a protective factor for lymph node metastasis(OR=0.357,P=0.024).CONCLUSION For papillary thyroid carcinoma patients aged≤40 years,with ultrasound findings of aspect ratio>1,multiple lesions,lesion diameter≥1 cm,calcification,and abundant blood flow,special attention should be paid to lymph node metastasis,appropriate treatment methods should be selected,and a reasonable lymph node dissection range should be formulated.

A novel analytical method was developed in this study by combining online solid phase extraction with ultra performance liquid chromatography-tandem mass spectrometry(Online SPE-UPLC-MS/MS)for simultaneous determination of 50 kinds of steroid hormones in surface water.Specifically,after high-speed centrifugation of 4 mL water samples,the supernatant was directly injected into an Oasis HLB online SPE column for enrichment and purification.Subsequently,the target compounds were transferred to the analytical column via valve switching for separation and analysis.The chromatographic separation was performed on a Thermo Acclaim RSLC C18 column(100 mm×2.1 mm,2.2 μm),using a mobile phase composed of 5 mmol/L ammonium fluoride aqueous solution and acetonitrile.Mass spectrometric detection was conducted in positive ion mode,utilizing multiple reaction monitoring(MRM)with quantification achieved by the internal standard method.The method validation demonstrated that the limits of detection(LOD)for the 50 kinds of steroid hormones ranged from 0.02 to 0.50 ng/L,while the limits of quantification(LOQ)were between 0.08 and 1.67 ng/L.The average recoveries in surface water samples at spiked concentrations of 5,20 and 200 ng/L were between 74.1％and 119％,with relative standard deviations(RSDs)of 0.2％to 9.9％.This method was applied to analyze 11 surface water samples collected from sites surrounding a pharmaceutical and chemical industrial park.A total of 44 kinds of steroid hormones were detected,with concentrations ranging from 0.11 to 88.6 ng/L,revealing the presence of hormone contamination in the environmental waters surrounding industrial areas.Compared with the traditional offline SPE methods,the proposed online SPE technique significantly reduced sample volume requirements and pretreatment time,while minimizing the loss of target compounds during the pretreatment process.Moreover,compared to reported online SPE techniques,this method achieved high-throughput analysis of multiple classes of steroid hormones,with lower detection limits and higher recoveries.Overall,this method provided rapid sample preparation,high sensitivity,and excellent stability,making it suitable for the direct analysis of trace steroid hormones in surface water.

Objective:To evaluate the clinical efficacy of a replay propeller distal perforator flap of the lateral circumflex femoral artery in reconstruction of the donor site defect left by the harvest of a free anterolateral thigh perforator flap (ALTPF).Methods:From June 2023 to June 2024, retrospective analysis of 11 patients with foot and ankle soft tissue defects were treated in the Department of Microsurgery, Sichuan Modern Hospital. The patients were 7 males and 4 females, aged 9-57 (average 28.6) years. Causes of injury were car accident (5 patients), machine crush (5 patients) and skin necrosis following a fall (1 patient). The size of soft tissue defects was 8.0 cm ×11.0 cm - 9.0 cm×14.5 cm. A reversed perforator island flap of distal descending branch of the lateral circumflex femoral artery was prepared to reconstruct the defect left at the donor site after the harvest of a free ALTPF. The ALTPFs were 8.5 cm × 11.5 cm to 9.5 cm × 15.5 cm in size, and the sizes of the perforator flap of descending branch of lateral circumflex femoral artery designed to reconstruct the donor site defects were at 5.0 cm × 9.0 cm to 6.0 cm × 12.0 cm. After the surgery, scheduled follow-ups were carried out at outpatient clinic and via telephone and WeChat reviews. Wound healing at recipient and donor sites, flap survival and functional recovery were observed.Results:All flaps survived smoothly after surgery, and the wounds in the donor and recipient sites healed primarily. No vascular compromise, wound dehiscence or significant swelling occurred. A total of 9 patients completed the 6-18 months postoperative follow-up, with an average of 11 months. Two patients lost in the follow-up. Only linear scars left in the donor sites, without significant impact on the thigh function. The colour and appearance of the flaps were natural.Conclusion:It is effective to use a distal replay flap of the descending branch of lateral circumflex femoral artery for reconstruction of the donor site defect left by the harvest of a free ALTPF.

Objective:To explore the potential lesional range of keloids by analyzing the transcriptomic characteristics, and to provide a molecular basis for understanding the recurrence of keloids following surgical excision.Methods:From July to December in 2022, 3 patients clinically diagnosed with keloids and treated with surgical excision at the Department of Dermatology and Venereology, Peking University First Hospital were included in the study. Samples of keloids and keloid-adjacent dermis were collected from these 3 patients, and normal dermal tissues adjacent to benign skin tumors were collected from 4 patients and served as controls. Dermal fibroblasts were obtained by primary cell culture and purification, which were then subsequently passaged to the second generation for transcriptome sequencing. Differential gene expression analysis, gene ontology (GO) -based functional analysis, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed. While analyzing differential expression genes, those with a fold change (FC) > 2 and a P value < 0.05 were defined as upregulated genes, whereas those with a FC < 0.5 and a P value < 0.05 were considered downregulated genes. The accuracy of the results was further validated by comparing them with published single-cell sequencing data on keloid and keloid-adjacent tissues (HRA000425 in GSA database) and single-cell sequencing data on the normal dermis (GSE130973 in GEO database). Key genes in keloid-adjacent dermal fibroblasts were validated in tissue samples from this study and the literature. Results:Compared with keloid-derived fibroblasts, keloid-adjacent and control dermal fibroblasts shared 63 upregulated genes enriched in biological processes including lipid transport ( P = 0.038) and ion transport ( P = 0.040) ; compared with control dermal fibroblasts, keloid-adjacent and keloid-derived fibroblasts shared 56 upregulated genes enriched in the transforming growth factor β signaling pathway ( P < 0.001), etc. When comparing keloid-derived fibroblasts and keloid-adjacent fibroblasts with control dermal fibroblasts, 79 genes were uniquely upregulated only in keloid-adjacent fibroblasts; after filtering based on gene expression thresholds and consistency, 13 candidate genes (average expression level > 1 000 and variance of expression level within groups < 30 000) closely related to the transcriptomic characteristics of keloid-derived fibroblasts were identified, including genes inhibiting keloid formation such as SMAD6 and SMAD7, as well as those promoting keloid formation such as MSX1, SNAI1, and EDN1, which were enriched in the biological processes such as cell growth, ossification and cartilage development (all P < 0.01). The enrichment analysis of the above-mentioned 13 genes on the ChEA3 website identified some enriched transcription factors, such as myogenic differentiation protein 1 (MYOD1) and myogenin (MYOG) (both P < 0.05) . Conclusions:Compared with keloid-derived fibroblasts and control dermal fibroblasts, the transcriptomics of keloid-adjacent fibroblasts were characterized by high-level coexpression of genes involved in both the inhibition and promotion of keloid formation, which may provide a molecular explanation for the similarity in morphology between keloid-adjacent tissues and normal skin tissues as well as for the potential mechanisms underlying the high recurrence rate of keloids.