1.Dosimetry verifications of the physical parameters of virtual wedge on a Siemens accelerator
Heli ZHONG ; Xiaodong LI ; Longxing LI
Chinese Journal of Radiation Oncology 1995;0(02):-
Objective To verify the wedge angle of virtual wedge and the relation between wedge factor and beam energy, field size, wedge angle and to study the difference in percent depth dose (PDD) of virtual wedge field, hard wedge field and open field.Methods Using wedge angle and wedge factor of 15?,30?,45?and 60? virtual wedge of Siemens Mevatron 6?MV and Primus 8?MV, 18?MV X rays were measured by RFA-plus 3D water phantom and RK finger chamber the PDD of the virtual wedge field, hard wedge field and open field were measured by Kodak XV-2 verifying film and FDM-300 film dosimeter. These PDDs were normalized to Dmax then compared. Results There was good conformation between virtual wedge measured by four point method and set value. The virtual wedge was almost equal to 1,with a maximal variation of 0.031 no matter what the value of beam energy, field size or wedge angle was. Generally, for certain energy and field size, the wedge factor of larger wedge angle was slightly larger than smaller wedge angle. For certain energy and wedge angle, the wedge factor of larger field was also a little larger than smaller field. The PDD of virtual wedge field was similar to that of open field. Conclusions The four point method measurement for virtual wedge angle is good for daily QA. Radiotherapy of virtual wedge field is not only simpler than hard wedge field,but also spares the beam output. The PDD comfarmation between virtual field and open field simplifies radiation treatment planning and increases the accuracy of wedge field therapy.
2.Effects of light intensity on the compressive strength and tensile strength of light-curing composite resin
Xin LU ; Yanjun LI ; Longxing NI
Journal of Practical Stomatology 2000;0(05):-
Objective: To study the effects of light intensity on the compressive strength and tensile strength of light -curing composite resin. Methods: 25 samples of Shade A (Dentsply,USA) light-curing composite resion in the size of 10?5?1(mm) and equally divided into 5 groups.The light intensities (mW/cm 2?40 s) of 300,500,800,300 mW/cm 2?10 s+500 mW/cm 2?30 s,300 mW/cm 2?10 s+800 mW/cm?30 s were applied during the light-curing in group 1,2,3,4 and 5 respectively.The compressive strength and tensile strength of of the samples were measured by computer-controlled electronic testing machine (type WDW-100). Results:The compressive strengths (MPa) of group 1,2,3,4 and 5 were 228.68?20.25,274.67?6.99,380.53?9.81,345.47?10.71 and 414.06?29.34 respectively (P
3.Study on Chemical Components of Swertia nervosa
Zhaoyun LI ; Zhiyuan WANG ; Huai XIAO ; Longxing LI
China Pharmacy 2016;27(15):2107-2108
OBJECTIVE:To study the chemical components of Swertia nervosa. METHODS:Silica gel column chromatogra-phy was used for purification and analysis of compounds’structure based on physicochemical properties and spectral data. RE-SULTS:Five compounds were isolated and identified in petroleum ether portion of S. nervosa,involving 1-hydroxy-3,7,8-trime-thoxyxanthone (1),1,8-dihydroxy-3,7-dimethoxyxanthone (2),1,8-dihydroxy-3,5-dimethoxyxanthone(3),1-hydroxy-3,5-dime-thoxyxanthone(4)and β-sitosterol(5). CONCLUSIONS:Compound 1,3 and 4 are isolated from S. nervosa for the first time,and the study has laid a foundation for the quality evaluation of S. nervosa.
4.Effects of FcγRIIb gene modified dendritic cells on immune tolerance of rat orthotopic liver transplantation
Liqiang LI ; Wu ZHANG ; Zhiwen LI ; Wentao YAN ; Longxing JIAO ; Minghao LI
Chinese Journal of General Surgery 2021;36(2):132-136
Objective:To study the effects of FcγRIIb gene modified dendritic cells on liver function and rejection after orthotopic liver transplantation in rats.Methods:The recombinant lentivirus expression vector TRE-FcγRIIb containing Lewis rat FcγRIIb gene was constructed by gene cloning technique. TRE-FcγRIIb expression virus and TET-on regulatory virus were packaged and co-infected with immature dendritic cells derived from DA rat bone marrow. The expression of FcγRIIb was detected. Donor rats DA and recipient Lewis were paired according to body weight and then randomly divided into three groups. The control group (group A) did not receive any pretreatment. The Lewis rats in group B were treated with cyclosporin A on the 2nd day after liver TX. Immature dendritic cells derived from bone marrow of DA rats were injected intravenously one day before liver TX in FcγRIIb gene modified immature dendritic cells (1×10 6 cells)group (group C). Blood and liver tissue were biopsied 7 days after operation to detect liver function and pathological changes. Results:The abnormal liver function in FcγRIIb gene modified immature dendritic cells group (group C) was significantly lower than that of control group 7 days after operation ( P<0.05), and the liver pathological rejection of FcγRIIb gene modified immature dendritic cells group (group C) was significantly lower than that of control group 7 days after operation ( P<0.05). The average survival days of rats in the control group was 12.8 days; the average survival days of rats in the cyclosporin A group was 65.3 days; the average survival days of rats in the FcγRIIb gene-modified immature dendritic cell group was 58.5 days. Conclusion:FcγRIIb gene modified immature dendritic cells can ameliorate liver dysfunction and acute liver rejection after orthotopic liver transplantation.
5.Peripheral dendritic cell subsets and changes in plasma monocyte chemoattractant protein 1 in patients with coronary heart disease.
Zikai SUN ; Wenliang ZHONG ; Yiming QIU ; Zhiliang LI ; Longxing CAO
Journal of Southern Medical University 2012;32(8):1157-1162
OBJECTIVETo assess the association between peripheral blood dendritic cells subtype distribution and plasma monocyte chemoattractant protein 1 (MCP-1) concentration in patients with coronary heart disease (CHD).
METHODSSixty consecutive CHD patients admitted in our department during the period from November, 2010 to December, 2011 were enrolled, including 10 with stable angina pectoris (SAP), 25 with unstable angina pectoris (UAP), and 25 with acute myocardial infarction (AMI), with 28 healthy volunteers as normal controls. All the subjects underwent routine tests and coronary angiography. The percentages of peripheral blood myeloid dendritic cells (mDCs) and plasma cell-like dendritic cells (pDCs) in peripheral blood mononuclear cells were detected by flow cytometry, and plasma MCP-1 levels were detected using enzyme-linked immunosorbent assay.
RESULTSThe percentage and absolute quantity of mDCs and pDCs were significantly lower in AMI and UAP groups than in the normal control and SAP groups (P<0.001). In the CHD patients, the plasma MCP-1 level was significantly higher than that in the normal control group (P<0.001) with an inverse correlation with the percentage of peripheral mDCs.
CONCLUSIONMCP-1 may promote the migration of mDCs into atherosclerotic plaques and mediate the local immune and inflammatory responses to aggravate plaque instability in CHD patients.
Adult ; Aged ; Case-Control Studies ; Chemokine CCL2 ; blood ; Coronary Disease ; blood ; Dendritic Cells ; cytology ; Female ; Humans ; Leukocytes, Mononuclear ; metabolism ; Male ; Middle Aged
6.Relationship between collateral circulation and cardiac function recovery in patients receiving percutaneous coronary intervention for a single left anterior descending artery.
Nina HONG ; Zhiliang LI ; Yanan ZHAO ; Linlin CHEN ; Longxing CAO ; Yue HAN ; Kai GUO ; Shanshan FU
Journal of Southern Medical University 2014;34(4):541-545
OBJECTIVETo explore the relationship between coronary collateral circulation following percutaneous coronary intervention (PCI) for a single left anterior descending artery and the recovery of cardiac function.
METHODSA total of 625 patients with coronary heart disease were retrospectively analyzed, who received selective coronary angiography demonstrating lesions involving a single left anterior descending artery and underwent stent placement between January, 2010 and December, 2012. According to Rentrop's classification, the patients were divided into group A (n=280) with Rentrop grades 1-3 and group B (n=325) with Rentrop grade 0. Group A were further divided into 3 subgroups according to the source of collateral circulation, namely group A1 (n=200) with contralateral collateral circulation, group A2 (n=44) with contralateral+ ipsilateral collateral circulation, and group A3 (n=36) with ipsilateral collateral circulation. The outcomes of cardiac function recovery were compared between groups A and B and between the 3 subgroups in group A.
RESULTSCompared with patients without collateral circulation, patients with collateral coronary circulation showed greater left ventricular ejection fraction increment and reduction in brain natriuretic peptide and red cell volume distribution width with also lower expansion left ventricular end-diastolic volume. Among the 3 subgroups in group A, cardiac function improvement was the most obvious in patients with contralateral+ ipsilateral collateral circulation (group A2) followed by those in group A3, and was the worst in group A1.
CONCLUSIONThe presence of collateral coronary circulation promotes cardiac function recovery in patients receiving PCI for lesions involving a single left anterior descending artery. Patients with contralateral+ipsilateral collateral circulation have the best cardiac function improvement followed by those with contralateral collateral circulation.
Aged ; Collateral Circulation ; Coronary Disease ; physiopathology ; therapy ; Female ; Humans ; Male ; Middle Aged ; Percutaneous Coronary Intervention ; Retrospective Studies
7.Evaluation of monitoring on serum silent information regulator-related enzyme 3, glucagon-like peptide-1 and angiopoietin-like protein 4 in patients with acute ischemic stroke
Longxing FU ; Caixiong LIN ; Lin LI ; Yunhong ZHU ; Yuanwen CHEN
Chinese Journal of Postgraduates of Medicine 2023;46(6):543-548
Objective:To investigate the value of monitoring on serum silent information regulator-related enzyme 3 (SIRT3), glucagon-like peptide-1 (GLP-1) and angiopoietin-like protein 4 (ANGPTL4) in patients with acute ischemic stroke (AIS).Methods:Eighty patients with AIS who treatment in Qiongzhong Li and Miao Autonomous County People′s Hospital from May 2019 to April 2022 were selected retrospectively as the observation group, and 60 healthy volunteers who underwent physical examination during the same period were selected as the normal control group. The levels of serum SIRT3, GLP-1, and ANGPTL4 between the two groups were compared. The neurological deficit degree of AIS patients was evaluated by National Institutes of Health Stroke Scale(NIHSS) and the correlation of SIRT3, GLP-1 and ANGPTL4 with neurological deficit degree were analyzed. The levels of serum SIRT3, GLP-1 and ANGPTL4 before and after treatment and their difference value were compared between different clinical outcome of AIS patients, the risk factors for poor clinical outcome of AIS patients were analyzed by Logistic regression analysis, the value of prediction was analyzed by receiver operating characteristic (ROC) curve.Results:The level of serum GLP-1 in the observation group was lower than that in the normal control group: (50.37 ± 5.69) nmol/L vs. (34.89 ± 4.26) nmol/L; and the levels of serum SIRT3 and ANGPTL4 in the observation group were higher than those in the normal control group: (50.37 ± 5.69) ng/L vs. (34.89 ± 4.26) ng/L, (15.07 ± 3.12) μg/L vs. (11.15 ± 2.63) μg/L, there were statistical differences ( P<0.05). The results of correlation analysis showed that the levels of serum SIRT3 and ANGPTL4 were positively correlated with the degree of neurological impairment in AIS patients( r = 0.631, 0.776, P<0.05), and the level of serum GLP-1 was negatively correlated with the degree of neurological impairment in AIS patients ( r = - 0.693, P<0.05). After treatment, 66 patients obtained good clinical outcome, the good outcome rate was 82.50%(66/80). The levels of serum SIRT3 and ANGPTL4 in the poor clinical outcome patients were higher than those in the good clinical outcome patients: (41.33 ± 4.74) ng/L vs. (37.82 ± 4.05) ng/L, (12.98 ± 2.17) μg/L vs. (11.69 ± 2.06) μg/L; the level of serum GLP-1 in the poor clinical outcome patients was lower than that in the good clinical outcome patients: (592.33 ± 98.44) nmol/L vs. (709.41 ± 125.31) nmol/L; the difference value of SIRT3, GLP-1 and ANGPTL4 before and after treatment in the poor clinical outcome patients were lower than those in the good clinical outcome patients: (10.22 ± 2.05) ng/L vs. (12.31 ± 2.94) ng/L, (268.21 ± 70.12) nmol/L vs. (379.92 ± 85.33) nmol/L, (2.18 ± 0.65) μg/L vs. (3.36 ± 0.94) μg/L, there were statistical differences ( P<0.05). The results of Logistic regression analysis showed that differences value of SIRT3, GLP-1 and ANGPTL4 before and after treatment were all independent influencing factors of poor clinical outcome in patients with AIS ( P<0.05). The results of ROC curve analysis showed that the area under the curve (AUC) of differences value of SIRT3, GLP-1 and ANGPTL4 before and after treatment in predicting poor clinical outcome were 0.701, 0.758 and 0.844, respectively, and had certain predictive value, the AUC of joint evaluation was the largest (0.912). Conclusions:The levels of serum SIRT3 and ANGPTL4 in patients with AIS are increased, and the level of serum GLP-1 is decreased, and they are related to the degree of neurological deficit. Clinical monitoring of their level changes is helpful for clinical evaluation of the clinical outcome of patients with AIS.
8.Meta-analysis of dosimetric comparison between volumetric-modulated arc therapy and intensity-modulated radiotherapy for breast cancer after modified radical mastectomy
Yan GAO ; Heli ZHONG ; Zhuangling LI ; Guangwei ZHANG ; Longxing LI ; Yabin SHI ; Xianming LI
Chinese Journal of Radiation Oncology 2021;30(11):1159-1166
Objective:To compare the dosimetric differences between volumetric-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT) on planning target volume (PTV) and organ-at-risk (OAR) for breast cancer after modified radical mastectomy, aiming to provide evidence-based reference for clinical practice.Methods:According to strict inclusion and exclusion criteria, literature search was performed in PubMed, Cochrane Library, FMRS, CNKI, Wanfang Data and VIP full text databases from the inception of databases up to March 2020. The controlled clinical trials of dosimetric comparison between VMAT and IMRT for breast cancer following modified radical mastectomy were selected. The meta-analysis was performed using Stata14 software.Results:The meta-analysis included 281 patients from 13 observational studies. Compared with IMRT, VMAT significantly increased the PTV dose coverage D 95%( P<0.001) and significantly improved the PTV homogeneity index (HI, P<0.001) and conformity index (CI, P=0.004). Compared with IMRT, VMAT more effectively decreased the ipsilateral lung V 20Gy (WMD=1.332, P=0.027) and contralateral lung V 10Gy ( P=0.003). There were no significant differences in theD mean, V 5Gy, V 10Gy and V 30Gy of the ipsilateral lung, D mean and V 5Gy of the contralateral lung, D mean, V 10Gy and V 30Gy of the heart between VMAT and IMRT (all P>0.05). Compared with VMAT, IMRT reduced the cardiac V 5Gy ( P=0.001). However, sensitivity analysis of included literature on cardiac V 5Gy showed that the P value was reversed, indicating that the stability of the results was poor. VMAT significantly shortened the delivery time ( P<0.001) and the number of monitor units ( P<0.001) compared to IMRT. Conclusion:Compared with IMRT, VMAT can achieves superior target dose coverage, HI and CI, better protection for the ipsilateral and contralateral lung, fewer monitor units and shorter delivery time.
9.Impact of the Varian real-time position management respiratory gating system on radiotherapy planning dosimetry
Fang ZHENG ; Heli ZHONG ; Hongtao CHEN ; Longxing LI ; Ding ZHANG ; Xin FU ; Yabin SHI ; Zihuang LI
Chinese Journal of Radiological Medicine and Protection 2022;42(9):685-690
Objective:To study the impact of the Varian real-time position management (RPM) respiratory gating system on radiotherapy planning dosimetry.Methods:The radiotherapy plans of 40 cases with thoracic or abdominal tumors were retrospectively selected in this study. The motion phantom for quality control was adopted to generate respiratory gating signals, and the 30%-60% stable phase at the end of expiratory was selected as the respiratory gating window. The dose verification for the abovementioned radiotherapy plans was performed using the Portal Dosimetry (PD) system under RPM respiratory gating mode with the Edge accelerator. Afterwards, dose analysis was performed with different γ passing rate criteria and the distribution characteristics of γ values were analyzed. Finally, the verification results between the non-gating mode and the gating mode were compared.Results:Under the respiratory gating mode, the passing rates of all intensity-modulated radiation therapy/volumetric-modulated arc therapy (IMRT/VMAT) plans with or without flattening filters were over 95.5% by γ criteria of (3%, 3 mm) or (3%, 2 mm) and were over 90% by stricter γ criteria of (2%, 2 mm). All plans met the clinical requirements recommended by the American Association of Physicists in Medicine (AAPM). The passing rates of dose verification under non-gating mode were slightly better than those under respiratory gating mode, and the differences between the two modes were statistically significant (3%/3 mm, Z =-1.45; 3%/2 mm, Z =-2.86; 2%/2 mm, Z =-3.70; 1%/1 mm, Z =-4.52; P<0.05). There was no significant difference in the minimum and maximum values of γ and the share of γ > 1.5 of plan verification result under the two modes. However, the average value and standard deviation of the γ were generally smaller under the non-gating mode. Conclusions:The impact of the introduction of RPM respiratory gating technology on dose is clinically acceptable, and the execution of these plans in this gating mode is safe and reliable.
10.Renal denervation: a new therapeutic approach for resistant hypertension.
Longxing CAO ; Qiang FU ; Binghui WANG ; Zhiliang LI
Chinese Medical Journal 2014;127(18):3302-3308
OBJECTIVETo review the advances in studies on renal denervation.
DATA SOURCESReferences concerning renal denervation and resistant hypertension cited in this review were collected from PubMed published in English and those of renal denervation devices from official websites of device manufacturers up to January 2014.
STUDY SELECTIONArticles with keywords "renal denervation" and "resistant hypertension" were selected.
RESULTSRenal and systemic sympathetic overactivity plays an important role in pathology of hypertension as well as other diseases characterized by sympathetic overactivity. Renal denervation is a new, catheter based procedure to reduce renal and systemic sympathetic overactivity by disruption of renal sympathetic efferent and afferent nerves through radiofrequency or ultrasound energy delivered to the endoluminal surface of both renal arteries. Although several studies have shown the efficacy and safety of renal denervation in the treatment of resistant hypertension and the potential benefit of the procedure in other diseases, Symplicity HTN 3 study, the most rigorous clinical trial of renal denervation to date, failed to meet its primary endpoint. The procedure also has other limitations such as the lack of long term, efficacy and safety data and the lack of the predictors for the blood pressure lowering response and nonresponse to the procedure. An overview of current renal denervation devices holding Conformité Européenne mark is also included in this review.
CONCLUSIONSRenal denervation is a promising therapeutic approach in the management of resistant hypertension and other diseases characterized by sympathetic overactivity. In its early stage of clinical application, the efficacy of the procedure is still controversial. Large scale, blind, randomized, controlled clinical trials are still necessary to address the limitations of the procedure.
Blood Pressure ; physiology ; Denervation ; methods ; Humans ; Hypertension ; Kidney ; innervation ; Neurosurgical Procedures ; Sympathetic Nervous System ; metabolism