Objective To evaluate the change of cardiac structure and function in patients with hypertrophic obstructive cardiomyopathy(HOCM)after ultrasound-guided percutaneous intramyocardial septal radiofrequency ablation(PIMSRA)via cardiac magnetic resonance(CMR).Methods Patients with HOCM who underwent PIMSRA,echocardiography and CMR preoperative scanning and one year after surgery were analyzed retrospectively.Myocardial structural and functional parameters were measured by Circle cardiovascular imaging post-processing software.The changes of myocardial parameters before and after surgery were compared by using paired sample t-test and Chi-square test.Results Compared with the preoperative assessment,patients'clinical symptoms and the cardiac function were significantly improved one year after surgery.The left ventricular outflow tract pressure gradient(LVOT-PG)was significantly decreased and length of mitral regurgitation was shortened one year after surgery compared with before surgery via ultrasound(P<0.05).Compared with the preoperative assessment,CMR showed that patients with end-systolic volume of left atrium,minimum volume of left atrium,transverse diameter of left atrium,thickness of ventricular septum and free wall of left ventricular at end-systolic section were significantly reduced,and left ventricular mass(LVM)was significantly decreased one year after surgery,with statistical significance between before and after surgery(P<0.001).One year after surgery,the left atrium ejection fraction(LAEF)was significantly increased(P<0.05),the maximum slope and the maximum signal intensity of the ventricular septum and the left ventricular free wall of the papillary muscle were significantly increased(P<0.001),and the peak time was significantly decreased(P<0.001)compared with before surgery.Conclusion After PIMSRA treatment,the systolic function of left atrium in HOCM patients is improved,and the microcirculation perfusion of left ventricular is significantly improved.

Although the mTOR-4E-BP1 signaling pathway is implicated in aging and aging-related disorders, the role of 4E-BP1 in regulating human stem cell homeostasis remains largely unknown. Here, we report that the expression of 4E-BP1 decreases along with the senescence of human mesenchymal stem cells (hMSCs). Genetic inactivation of 4E-BP1 in hMSCs compromises mitochondrial respiration, increases mitochondrial reactive oxygen species (ROS) production, and accelerates cellular senescence. Mechanistically, the absence of 4E-BP1 destabilizes proteins in mitochondrial respiration complexes, especially several key subunits of complex III including UQCRC2. Ectopic expression of 4E-BP1 attenuates mitochondrial abnormalities and alleviates cellular senescence in 4E-BP1-deficient hMSCs as well as in physiologically aged hMSCs. These f indings together demonstrate that 4E-BP1 functions as a geroprotector to mitigate human stem cell senescence and maintain mitochondrial homeostasis, particularly for the mitochondrial respiration complex III, thus providing a new potential target to counteract human stem cell senescence.
Mesenchymal Stem Cells/physiology* ; Cellular Senescence ; Homeostasis ; Cell Cycle Proteins/metabolism* ; Adaptor Proteins, Signal Transducing/metabolism* ; Mitochondria/metabolism* ; Electron Transport Complex III/metabolism* ; Humans ; Cells, Cultured

Purpose To investigate the feasibility of CT-based feature tracking technology to quantify left ventricular myocardial strain(MS)and its significance in hypertrophic obstructive cardiomyopathy(HOCM).Materials and Methods A total of 35 HOCM patients who underwent cardiac coronary angiography from March 2019 to December 2021 in the First Affiliated Hospital of the Air Force Military Medical University were retrospectively included,and a total of 60 cases who were negative for cardiac coronary angiography among those who visited the hospital with suspected coronary artery disease were randomly enrolled.Conventional cardiac functional parameters and MS parameters were quantified via post-processing software,and differences of parameters between the groups were analyzed.The diagnostic efficacy of MS parameters for HOCM was further evaluated.Results Compared to the control group,the HOCM group exhibited significant increases in various conventional left ventricular functional parameters,including left ventricular wall thickness,mass,mass index,end-diastolic volume and stroke volume(t=2.119 to 24.861,all P<0.05).However,there were no statistically significant differences in end-systolic volume and cardiac output between the two groups(P>0.05).The global longitudinal and radial strain values of HOCM group were significantly lower than those of control group(t=12.857,-6.427,P<0.01),while the endocardial global circumferential strain of HOCM group was significantly higher than that of control group(t=-2.369,P<0.05).Among MS parameters,global longitudinal strain exhibited the best diagnostic efficacy for HOCM,with an area under the curve of 0.997.A cutoff value of≤20.78%for global longitudinal strain showed that the sensitivity and specificity was 100%and 95%,respectively.Conclusion The MS parameters quantified by the CT-based feature tracking technique are superior to left ventricular ejection fraction in quantifying left ventricular function,with the highest sensitivity and specificity for early myocardial function impairment of longitudinal strain.In addition,the technique has good repeatability and is expected to become a new indicator for the assessment of myocardial function in HOCM.

Humans ; Mechanistic Target of Rapamycin Complex 2/metabolism* ; Multiprotein Complexes/metabolism* ; Neural Stem Cells/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Rapamycin-Insensitive Companion of mTOR Protein/metabolism* ; TOR Serine-Threonine Kinases/metabolism*

Cell Cycle Proteins ; Microtubule-Associated Proteins

Objective:To investigate the role of HIV-1 negative regulator (Nef) in HIV-1 neuropathogenicity.Methods:Five different HIV-1 nef genes were obtained from the central nervous system (CNS) and peripheral regions (basal ganglia, frontal cortex, meninges, temporal cortex and spleen) of a patient with HIV-1-associated dementia (HAD). The recombinant pcDNA3.1- nef eukaryotic expression vectors were constructed by connecting them with pcDNA3.1 vector and transfected into human glioma cell line U87 respectively. The expression of Nef protein was detected by immunohistochemistry and Western blotting at 22ndhour, 27 th hour, 32nd hour, 37th and 42nd hour after transfection. The result were analyzed quantitatively by JEDA801D and JD-801 software. The supernatant of U87 cells was collected every 5 hours from 27th hour to 62nd hour after transfection. The levels of TNF-α and IL-1 β in the supernatant were determined by ELISA, and the dynamic expression of the two cytokines was analyzed. Results:Five recombinant pcDNA3.1- nef eukaryotic expression vectors of nef genes from different tissues of an HAD patient were successfully constructed and transfected into U87 cells. The result of immunohistochemistry showed that Nef protein began to express at 42nd hour after transfection, which was further confirmed by Western blot. The result of ELISA showed that the levels of cytokines in the supernatant of each group increased gradually with time from 22ed hour to 37th hour after transfection, but there was no significant difference among the groups (TNF-α: F=0.445, P=0.837; F=0.579, P=0.742; F=0.617, P=0.714; F=2.728, P=0.057. IL-1β: F=2.656, P=0.062; F=0.485, P=0.809; F=0.165, P=0.982; F=2.463, P=0.093); The levels of TNF-α and IL-1 β in the experimental group were significantly higher than those in the control group from the 42nd hour ( P<0.05); after 42nd hour, the levels of cytokines in each group gradually decreased, and the levels of TNF-α and IL-1 β remained stable from the 57th hour to the 62nd hour, while the levels of TNF-α and IL-1 β in the experimental group were higher than those in the control group from the 42nd hour to the 62nd hour, the difference was still statistically significant (TNF-α: F=241.310, P<0.001; F=242.638, P<0.001; F=250.114, P<0.001; F=143.877, P<0.001; F=146.172, P<0.001. IL-1β: F=251.578, P<0.001; F=188.816, P<0.001; F=276.240, P<0.001; F=238.136, P<0.001; F=163.361, P<0.001), and there was no significant difference among the experimental groups ( P>0.05). Conclusions:HIV-1 Nef protein can induce and enhance the secretion of TNF-α and IL-1 β in U87 cells. However, the amino acid variation of HIV-1 Nef protein from different sources in an HAD patient had no effect on the secretion of TNF-α and IL-1 β.

Objective:To study the value hyperthermic intraperitoneal chemoperfusion after ruptured and hemorrhage of hepatocellular carcinoma.Methods:A retrospective study was conducted on 53 patients with ruptured hepatocellular carcinoma treated in Zhongshan Hospital Affiliated to Sun Yat-sen University from January 1, 2009 to January 1, 2019.Patients who underwent surgical resection combined with hyperthermic intraperitoneal chemoperfusion were included into the experimental group. Those who underwent surgical treatment only were included into the control group. The clinical data, postoperative hospital stay, complications, long-term tumor-free survival and overall survival were analyzed. Independent risk factors affecting prognosis were also determined.Results:Of the 33 patients in the experimental group, there were 27 males and 6 females, with a mean age ± s. d. being 50.49±11.59 years. There were 20 patients in the control group, including 17 males and 3 females, with a mean ± s. d. of 53.70±13.89 years. There were no significant differences in the length of postoperative hospital stay and complication rates between the two groups ( P>0.05). The tumor-free survival rate of the experimental group was significantly higher than that of the control group ( P<0.05). There was no significant difference in overall survival rates between the two groups ( P>0.05). Cox multivariate analysis showed that histological classification [ HR(95% CI): 27.700(1.695-452.794); 42.754(2.091-874.034)] and hyperthermic intraperitoneal chemoperfusion [ HR(95% CI): 0.238(0.086-0.661); 0.205(0.069-0.611)] were independent risk factors affecting tumor-free survival and overall survival (all P<0.05). Conclusion:Hyperthermic intraperitoneal chemoperfusion after surgical resection for ruptured hepatocellular carcinoma is a safe and effective treatment.

Trametes versicolor has strong ability to degrade environmental organic pollutants. NADPH-cytochrome P450 reductase (CPR) of T. versicolor transfers electron to cytochrome P450s (CYPs) and participates in the degradation process of organic pollutants. Sequence analysis showed that the genome of T. versicolor contains 1 potential CPR and multiple potential CYP sequences. To further study the molecular mechanism for the involvement of T. versicolor CPR in the cellular degradation of organic pollutants, a CPR gene from T. versicolor was cloned and heterologously expressed in Escherichia coli. Subsequently, the main properties of the recombinant enzyme were investigated. A truncated CPR protein lacking the predicted membrane anchor region (residues 1-24), named CPRΔ24, was overexpressed as a soluble form in E. coli. The recombinant CPRΔ24 protein showed a molecular weight consistent with the theoretical value of 78 kDa. Recombinant CPRΔ24 was purified using a Ni²⁺-chelating column followed by size exclusion chromatography. The specific activity of the purified CPRΔ24 was 5.82 U/mg. The CPRΔ24 enzyme displayed the maximum activity at 35 ℃ and pH 8.0. It has different degrees of tolerance against several types of metal ions and organic solvents. The apparent Km and kcat values of recombinant CPRΔ24 for NADPH were 19.7 μmol/L and 3.31/s, respectively, and those for the substrate cytochrome c were 25.9 μmol/L and 10.2/s, respectively, under conditions of 35 ℃ and pH 8.0. The above research provides the basis for exploring the functional mechanism of T. versicolor CPR in the degradation pathway of environmental organic pollutants.

Objective:To evaluate the effects of shade and light irradiation condition on the polymerization of composite resin core material.Methods:The light-proof silicon rubber cuboid mold with one end open were stringed and filled by dual-cured flowable composite resin core material with the shade of dentine and white(Paracore) respectively,then the open end of mold was irradiated directly by a light unit at 1 000 mW/cm2 ×20 s and 3 200 mW/cm2 ×6 s respectively.And all specimens of 4 groups(n =5) were stored in the light-proof box.1 h and 24 h after irradiation,Knoop microhardness was measured along the vertical surfaces of the specimens at the depth of 1,2 and 3 mm respectively.Data were analyzed by One-way ANOVA.Results:At all light irradiation conditions,the hardness of all specimens decreased with the increase of measurement depth.24 h after irradiation,the hardness of dentine shade specimens at each measurement depth showed no difference between 1 000 mW/cm2 × 20 s and 3 200 mW/cm2 × 6 s irradiation,while the white shade specimens irradiated by 1 000 mW/cm2 × 20 s showed higher hardness than those by 3 200 mW/cm2 × 6 s.Conclusion:To obtain sufficient polymerization of composite core material with different shade optimal light irradiation condition should be selected.