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.

Objective:To construct a porcine model of ischemia with non-obstructive coronary artery (INOCA) and explore the diagnostic value of a one-stop noninvasive method including CT myocardial perfusion imaging (CT-MPI) and coronary CT angiography (CCTA).Methods:Twelve swines were divided into the experimental group (9) and the normal group (3). Coronary microvascular dysfunction (CMD) porcine model was constructed in the experimental group by inducing diabetes mellitus, chronic kidney disease, and hypercholesterolemia. Invasive coronary angiography (ICA) and functional examination were performed on all 7+3 trial swines to clarify the INOCA diagnosis after completion of the modeling. Then, CT-MPI and CCTA were performed on all individuals to explore the CT-MPI and CCTA characteristics of INOCA porcine models. CT-MPI parameters, including myocardial blood flow (MBF), and myocardial blood volume (MBV) in rest and stress conditions, and CCTA parameters, including severity of stenosis and CAD-RADS, were analyzed.Results:ICA and functional tests showed that all swines in the experimental group met the diagnostic criteria for INOCA, which meant that INOCA porcine model was constructed successfully. CCTA results confirmed that there was no obstructive coronary stenosis in all 10 swines which were examined, which was consistent with ICA findings. CT-MPI results demonstrated that the mean MBF values, as well as the mean MBV values, in the rest and stress condition of each swines in the experimental group were lower than those of the control group. In contrast to the control group, the mean MBF and MBV values of swines in the experimental group in stress condition were generally lower than those in resting condition.Conclusions:In this study, a porcine model of CMD is successfully constructed by inducing hypercholesterolemia+diabetes mellitus+chronic kidney disease. ICA and invasive functional tests show that this CMD model meet the diagnostic criteria for INOCA. It has been confirmed that one-stop CT multimodality examination including CT-MPI and CCTA can be used for the diagnosis of INOCA as a noninvasive diagnostic method.

Objective:To explore the difference of the vessel and plaque characteristics, myocardial perfusion and cardiac function between patients with ischemia with non-obstructive coronary artery disease (INOCA) and obstructive coronary artery disease (CAD).Methods:From July 2021 to June 2022, 101 patients with angina were referred to dynamic computed tomography myocardial perfusion (CTP) and coronary computed tomography angiography (CCTA) and retrospectively included in our hospital. Based on the results of CTP and CCTA, patients were divided into INOCA (27 cases), moderate obstructive CAD (26 cases) and severe obstructive CAD (48 cases). The anatomical coronary artery stenosis, plaque characteristics and myocardial perfusion features of all patients were analyzed. Furthermore, left ventricular global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) were obtained on full-phase reconstruction CCTA image by using Medis Suite 3.2 postprocessing software. Multigroup analysis used one way ANOVA or Kruskal Wallis H test. Results:Patients with INOCA were younger than patients with moderate and severe obstructive CAD ( P<0.001). INOCA patients (7.4%, 2/27) had lower rate of positive remodeling than both moderate (57.7%, 15/26, P<0.001) and severe obstructive CAD patients (33.3%, 16/48, P=0.017). The percentage of ischemic myocardium volume in patients with INOCA were similar with those in patients with severe CAD (all P>0.05), but significantly higher than those in patients with moderate CAD (all P<0.05). No significant difference in terms of GLS was detected between patients with INOCA [-17.4% (-21.6%, -11.6%)] and severe CAD [-17.6% (-21.9%, -14.8%), P=0.536], however, patients both with INOCA and severe CAD also had higher GLS than patients with moderate obstructive CAD [-22.3% (-29.8%, -19.0%), all P<0.05]. Conclusions:Based on"one-stop-shop"CTP combined with CCTA imaging, early cardiac functional changes including abnormal myocardial perfusion and myocardial strain in INOCA patients were similar to those in patients with severe obstructive CAD and more severe than those in patients with moderate obstructive CAD.

OBJECTIVES: This study evaluated the association between obesity and glaucoma in middle-aged and older people. A population-based retrospective cohort study was conducted using data from the China Health and Retirement Longitudinal Study. METHODS: Glaucoma was assessed via self-reports. Multivariate logistic regression analysis and a Cox proportional hazards model were used to assess the relationship between obesity and glaucoma risk. RESULTS: Older males living in urban areas who were single, smokers, and non-drinkers were found to have a significantly higher incidence of glaucoma (all p<0.05). Diabetes, hypertension, and kidney disease were also associated with higher glaucoma risk, while dyslipidemia was associated with lower risk (all p<0.05). After the model was adjusted for demographic, socioeconomic, and health-related variables, obesity was significantly associated with a 10.2% decrease in glaucoma risk according to the Cox proportional hazards model (hazard ratio, 0.90; 95% confidence interval [CI], 0.83 to 0.97) and an 11.8% risk reduction in the multivariate logistic regression analysis (odds ratio, 0.88; 95% CI, 0.80 to 0.97). A further subgroup analysis showed that obesity was associated with a reduced risk of glaucoma in people living in rural areas, in smokers, and in those with kidney disease (all p<0.05). Obesity also reduced glaucoma risk in people with diabetes, hypertension, or dyslipidemia more than in healthy controls (all p<0.05). CONCLUSIONS This cohort study suggests that obesity was associated with a reduced risk of glaucoma, especially in rural residents, smokers, and people with kidney disease. Obesity exerted a stronger protective effect in people with diabetes, hypertension, or dyslipidemia than in healthy people.

Objective:To investigate the differences of white matter diffusion properties between vulnerable and resistant individuals to continuous attention after sleep deprivation.Methods:According to the psychomotor vigilance test performance before and after sleep deprivation, the participants were divided into the vulnerable group( n=24) and resistant group( n=25). All participants underwent diffusion tensor imaging (DTI) scans.Tract based spatial statistics(TBSS) was used to compare fractional anisotropy(FA), mean diffusivity(MD), axial diffusivity(AD), radial diffusivity(RD) maps between the two groups.Spearman correlation analysis was conducted by SPSS 24.0 to investigate the relationships between the altered DTI metrics and PVT task performance. Results:(1) Compared with resistant group, FA value of vulnerable group decreased in the body of corpus callosum(x, y, z=-8, 9, 25, t=-7.855), right superior longitudinal fasciculus(x, y, z=-39, -7, 26, t=-6.252), bilateral anterior limb of internal capsule(x, y, z=-13, 8, 13, t=-5.235; x, y, z=12, 8, 3, t=-5.024) and right posterior thalamic radiation(x, y, z=-26, -56, 17, t=-5.469)(TFCE corrected, P<0.05, cluster size≥50 voxel). (2) Compared with resistant group, MD value of vulnerable group increased in the body of corpus callosum(x, y, z=-3, -6, 26, t=7.613), right superior longitudinal fasciculus(x, y, z=-31, -19, 38, t=5.314), bilateral anterior limb of internal capsule(x, y, z=-16, 7, 8, t=6.898; x, y, z=15, 5, 7, t=6.652), splenium of corpus callosum(x, y, z=27, -53, 17, t=6.541), and AD value increased in the right superior longitudinal fasciculus(x, y, z=-33, -19, 39, t=4.892), splenium of corpus callosum(x, y, z=-22, -49, 21, t=5.450), genu of corpus callosum(x, y, z=4, 26, 0, t=4.332), as well as RD value increased in the right superior corona radiata(x, y, z=-17, 1, 33, t=7.558), body of corpus callosum(x, y, z=4, -8, 26, t=6.699), right anterior limb of internal capsule(x, y, z=-12, 7, 3, t=5.212) (TFCE corrected, P<0.05, cluster size≥50 voxel). (3) Correlational analysis revealed that the negative correlations were found between PVT task performance and the FA value in the right superior longitudinal fasciculus( r=-0.492, P<0.001), right anterior limb of internal capsule( r=-0.510, P<0.001), right posterior thalamic radiation( r=-0.502, P<0.001) and body of corpus callosum( r=-0.464, P<0.001). The positive correlations were found between PVT task performance and the MD value in the body of corpus callosum( r=0.500, P<0.001), right superior longitudinal fasciculus( r=0.499, P<0.001), splenium of corpus callosum( r=0.462, P<0.001), right anterior limb of internal capsule( r=0.471, P<0.001), and AD value in right superior longitudinal fasciculus( r=0.643, P<0.001), as well as RD value in right superior corona radiate( r=0.498, P<0.001) (Bonferroni corrected, P<0.003). Conclusion:Differences in the microstructural characteristics of white matter fiber tracts in specific brain regions may constitute the potential neuropathological basis for the phenotypes of vulnerable and resistant individuals to continuous attention after sleep deprivation.

Objective:To assess the value of coronary CT angiography(CCTA) based vessel characteristics and plaque features in diagnosing ischemic stenosis.Methods:From April 2014 to June 2021, 129 patients (including a total of 158 coronary arteries) who underwent CCTA, then completed invasive coronary angiography (ICA) as well as fractional flow reserve(FFR) within 30 days were retrospectively enrolled. All coronary arteries were divided into ischemic group (FFR≤0.80, n=77) and non-ischemic group (FFR>0.80, n=81). Vascular characteristics, high-risk plaque features, quantitative parameters and the morphology of plaque were obtained from CCTA images. Independent samples t-test, Wilcoxon rank sum test and χ 2 test were used to compare afore-mentioned variables between the ischemic group and the non-ischemic group. The logistic regression model was used to analyze the risk predictors for ischemic stenosis. Results:Compared with non-ischemic group, the stenosis degree of coronary arteries in ischemic group was more serious(72.09%±8.55% vs. 63.52%±13.49%; t=4.765, P<0.001). The proportion of left anterior descending artery(LAD) lesions in ischemic group was higher than that of non-ischemic group [88.31%(68/77)vs. 55.56%(45/81); χ 2=20.793, P<0.001]. In terms of CCTA plaque characteristics, the ischemic group demonstrated longer plaque length, smaller minimum lumen area, larger plaque burden, increased percent plaque diffuseness, and diffuse lesions were more common. As for morphological characteristics of plaque, the proportions of plaques with rectangle shape, proximal longitudinal eccentric shape and distal longitudinal eccentric shape were higher than those of non-ischemic group, whereas cosine eccentric plaques were more common in the non-ischemic group( P<0.001). Multivariate logistic regression analysis showed that the stenosis severity(OR =1.09, 95 %CI 1.04-1.14, P<0.001), LAD involvement(OR =4.23,95 %CI 1.01-17.72, P=0.049), diffuse lesion(OR =6.71,95 %CI 1.43-31.52, P=0.016), proximal longitudinal eccentric shape (OR =3.77,95 %CI 1.27-11.16, P=0.017), and distal longitudinal eccentric shape (OR =3.91,95 %CI 1.19-12.85, P=0.025) were the independent influence factors for ischemic stenosis. Conclusion:The CCTA-based stenosis degree of coronary artery, LAD involvement, diffuse lesion, proximal longitudinal eccentric shape, distal longitudinal eccentric shape were important influence factors for ischemic stenosis.

Objective:To explore the lesion characteristics and predictors of invasive coronary angiography (ICA)-verified obstructive lesions with fractional flow reserve (FFR)>0.80, that is, anatomy-function mismatch.Methods:A total of 515 obstructive vessels in 419 coronary disease patients from 11 Chinese medical centers undergoing coronary CT angiography and ICA and FFR were retrospectively analyzed. All vessels had one target lesion with diameter stenosis ≥50 % by ICA. There were 229 vessels in the match group (FFR≤0.80) and 286 vessels in the mismatch group (FFR>0.80). The lesion characteristics including lesion territory, the distance of the coronary artery ostium to the proximal end of the lesion, minimum lumen area, reference lumen area, plaque length and burden, plaque volume and component volume, remodeling index and plaque morphological complexity were measured and compared between the two groups. Optimal thresholds of quantitative plaque characteristics were defined by Yoden index. Logistic regression analysis was used to analyze the predictors of anatomy-function mismatch. Area under receiver operating characteristic curve (AUC) was used to analyze the ability of different lesion features to predict mismatched lesions.Results:The coronary stenosis, plaque burden and length, plaque volume (including each component volume) in the mismatch group were smaller than those in the match group, and FFR, minimum lumen area were larger (all P<0.05). Left anterior descending artery (LAD) lesion and severe complex plaque were more common in the match group than the mismatch group with a statistically significant difference. Univariate logistic regression analysis showed that LAD lesion, minimum lumen area>4 mm 2, plaque burden and length, plaque calcification volume<27 mm 3, plaque lipid volume<30 mm 3, plaque fiber volume<150 mm 3 and plaque morphological complexity were predictiors of anatomic function mismatched lesions; Multivariate logistic regression showed that the minimum lumen area>4 mm 2 (OR=3.371, 95%CI 1.903-5.973, P<0.001), plaque lipid volume<30 mm 3 (OR=3.014, 95%CI 1.691-5.373, P<0.001), plaque morphological complexity (mild OR=17.772, 95%CI 8.072-39.128, P<0.001, moderate OR=6.383, 95%CI 3.739-10.896, P<0.001) were independent predictors of mismatched lesions. The AUC of the model based on the minimum lumen area, plaque lipid volume and morphological complexity was 0.824, which was superior to either of the plaque feature alone ( P<0.001). Conclusions:The minimum lumen area, lipid volume and plaque morphological complexity are independent predictors of the anatomical-functional mismatch lesions, and the combination can significantly improve the prediction value.

A novel method was developed for the content assay and related substances determination of neomycin sulfate by high performance liquid chromatography combined with pulsed amperometric detection(HPLC-PAD). The HPLC was performed on Thermo AcclaimTMAmG C18(4. 6 mm×150 mm, 3 μm). The mobile phase consisted of aqueous solution with 2% trifluoroacetic acid containing 0. 01% pentafluoropropionic acid and 0. 6%NaOH. The pulsed amperometric detector was operated with aquadruple-potential waveform for the detection. Neomycin B, Neomycin C and thirteen related substances were adequately separated by the established HPLC conditions. The limits of detection(LOD)and quantification(LOQ)of neomycin B and neomycin C were both 1. 75 ng and 3. 5 ng, respectively. Good linearities of neomycin B and neomycin C were found in their respective ranges which their correlation coefficients were greater than 0. 998 5. The established method is characterized by high specificity, sensitivity and wide range of linearity which has a good application prospect and provides the basis for improving the standard and quality control of neomycin sulfate.

Objective To analyze preoperative CT angiography (CTA)imaging features of cervical arteries in patients with acute type A aortic dissection followed by postoperative neurological dysfunction (ND),and the correlations between risk factors and ND.Methods Clinical and imaging data of 110 patients who underwent repair of acute type A aortic dissection were analyzed retrospectively.The samples were categorized into two groups based on the presence or absence of ND.The clinical,perioperative and imaging data were compared between the ND group and the non ND (NND)group.Univariate and multivariate analyses were performed to identify predictors related with ND.Results A total of 100 patients were finally included in this study,and 18 patients(18%)developed with ND after aortic surgery.No significant differences in clinical and perioperative variables were observed between the ND group and the NND group (P＞0.05).However,on preoperative CT images,a dissection entry localized in the aortic arch (94.4% in the ND group), common carotid artery tear (83.3% in the ND group)and unilateral internal carotid artery density decrease (44.4% in the ND group) were all significantly higer than those in th NND group (P＜0.05 ).No significant difference were observed in true lumen stenosis of ascending aorta (P=0.053),retrograde dissection (P=0.913)and intimal tear (P=0.267)between ND group and NND group.The Logistic regression analysis revealed that a dissection entry localized in aortic arch (OR=21.325,P=0.008),common carotid artery tear (OR=14.441,P=0.022)and unilateral internal carotid artery density decrease (OR=9.141,P=0.024)were independent determinants of postoperative ND.Conclusion Preoperative CTA of cervical arteries can provide more imaging features,that may be indicative of postoperative ND.

Background and purpose:Stromal tumor is one of the common gastrointestinal mesenchymal tumors. There is certain understanding about the typical cases. However, the diagnosis of those occurring in rare location or with rare imaging findings is often difficult. This research summarized this kind of cases,in order to increase the radiological knowledge of the disease.Methods:This study retrospectively analyzed clinical, radiological and pathological data from 550 patients who had stromal tumor conifrmed by pathology in our hospital. Those with incomplete data were eliminated. Forty-nine patients were selected for further study according to the typical imaging findings.Results:Among these 49 patients, 9 were pathologically confirmed to have extra-gastrointestinal stromal tumor, while 40 patients had gastrointestinal stromal tumor. Among the patients with gastrointestinal stromal tumor, 22 were found in rare locations, 12 in retroperitoneal space, 3 in omentum majus and mesenterium, 5 in esophagus, and 2 in prostate. Obvious cystic degeneration was found in 16 patients. Bulky calciifcation, such as lfake or annulus, was found in 7 patients. The analysis result of risk-stratiifcation showed 19 patients were conifrmed as high-grade among the patients with tumors found in rare locations, 15 as high grade among those with obvious cystic degeneration, and 7 as high-grade among those with extra-gastrointestinal stromal tumor.Conclusion:Rare stromal tumor often occurs in the locations, such as retroperitoneal space, omentum majus and mesenterium. Obvious cystic degeneration and bulky calciifcation can be seen. The risk-stratiifcation of these patients often showed high-grade. Comprehensively analyzing its clinical features and imaging ifndings can help improve the diagnostic accuracy.