1.Establishment of a hemorrhagic retinal detachment model in rabbits
Zifeng ZHANG ; Yusheng WANG ; Yannian HUI
Chinese Journal of Ocular Fundus Diseases 2001;0(03):-
Objective To establish a hemorrhagic retinal detachment (HRD) model for the study of the damage and treatment of HRD. Methods Fourteen rabbits (28 eyes) were divided into the HRD (12 eyes) and control (16 eyes) group randomly. Autologous anticoagulated blood (0.2 ml) was transvitreally injected into the rabbits′ subretinal space with a special glass micropipette in HRD group (12 eyes); while 0.2 ml saline with or without heparin sodium (2.5 U/ml) was respectively injected into subretinal space respectively of the rabbits in heparin saline control group (6 eyes) and saline control group (3 eyes); furthermore, another 2 control groups, i.e.,pseudo injection group (3 eyes, single retinal puncturing without subretinal injection) and normal group (4 eyes of 2 normal rabbits) were also set. The conditions of the occurrence and representation of the retinal detachment (RD) were observed and analysed by means of ophthalmoscopy, optical coherence tomography (OCT) and ultrasound A and (or) B scan examinations in the subsequent 28 days after the operation. Results After the operation, HRD occurred in all eyes of the rabbits in HRD group. The area of HRD extended from 10 to 12 disc diameter(DD). The obvious elevation of RD maintained to 14 days, and the residual subretinal hemorrhage was still observed till 28 days. The obvious RD of the rabbits in heparin saline and saline control group was only kept for no more than 12 hours. The retinal puncture hole in pseudo injection group disappeared 2 days after the operation, and there was no change in retina of rabbits in normal control group. Conclusion It is convenient, practical and effective to establish a HRD model by means of transvitreal subretinal injection of autologous anticoagulated blood.
2.Investigation of dose verification of esophageal carcinoma intensity modulated radiotherapy
Dan LIU ; Zifeng CHI ; Wei ZHANG ; Lan WANG ; Chun HAN
Chinese Journal of Radiation Oncology 2011;20(1):64-68
Objective To compare the results of three dose verification solutions of esophageal carcinoma IMRT plans. Methods Seven esophageal carcinoma cases were planned with Pinnacle 8.0 h.The MATRIXX and Delta4 were chosen as the two-dimensional dosimetry and three-dimensional dosimetry.IMRT plans and Delta4 phantom plans were also recalculated by Monte Carlo. Gamma values were evaluated for MATRIXX and Delta4 with 3 mm/3% gamma criteria. For the comparison of Pinnacle, Delta4 and Monte gamma maps, the dose distribution in central plane, dose profiles and dose-volume histograms were used to evaluate the agreement. Results The gamma maps comparison show that with 3 mm/3% gamma criteria an over 98% pass ratio was obtained by MATRIXX measurement. A 94. 4% gamma pass ratio whicl.contains 4 fields gamma pass ratio lower than 90%, was obtained by Delta4 measurement. A 97.6% and 99. 8% gamma pass ratio was obtained between the Delta4 measurement and Monte Carlo simulation with 2 mm/2% and 3 mm/3% gamma criteria. The dose distribution in central plane and dose profiles from Pinnacle calculation were almost in agreement with both the Monte Carlo simulation and Delta4 measurement. The DVH plot have slightly differences between Pinnacle and Delta4 measurement as well as Pinnacle and Monte Carlo simulation, but have excellent agreement between Delta4 measurement and Monte Carlo simulation. Conclusions It was shown that all the three methods can be used very efficiently to verify esophageal carcinoma IMRT delivery, Delta4 and Monte Carlo simulation no data missed. The primary advantage of Delta4 is the fact it can measure true 3D dosimetry while Monte Carlo can simulate in patients CT images but not in phantom.
3.A study of parameters of a volumetric modulated arc therapy plan for cervical and upper esophageal cancer
Dan LIU ; Ruohui ZHANG ; Zhonghao JING ; Mingchang MIAO ; Zifeng CHI
Chinese Journal of Radiation Oncology 2016;25(8):862-866
Objective To figure out the optimal parameters of a volumetric modulated arc therapy ( VMAT) plan for cervical and upper esophageal cancer by quality evaluation of VMAT plans with different parameters, and to provide a reference for the design of clinical VMAT treatment plan. Methods Ten patients with cervical esophageal cancer and ten patients with upper esophageal cancer were enrolled as subjects. The Nucletron Oncentra 4. 3 treatment planning system was used to generate plans for Elekta Synergy VMAT accelerator. Six VMAT plans were made with variation in the gantry angle ( 2°, 3°, and 4°), the maximum delivery time (80 s, 110 s, and 150 s), and the collimator angle (0° and 45°). The doses to the planning target volume and organs at risk were analyzed by paired t test. Results For cervical and upper esophageal cancer, the quality of VMAT plans with a collimator angle of 45° was better than those with a collimator angle of 0°(P=0. 003?0. 007). For cervical esophageal cancer, there was no significant difference in quality between VMAT plans with a maximum delivery time of 110 s or 150 s and those with a maximum delivery time of 80 s ( P>0. 05 );for upper esophageal cancer, there was also no significant difference in quality between VMAT plans with three different maximum delivery times ( P>0. 05 ) . For cervical esophageal cancer, the VMAT plans with a gantry angle of 3° had a better quality than those with a gantry angle of 2° or 4°(P=0. 010?0. 048). For upper esophageal cancer, the VMAT plans with a gantry angle of 3° had a better quality than those with a gantry angle of 4° ( P=0. 010?0. 048) . Compared with those with a gantry angle of 2° , the VMAT plans with a gantry angle of 3° had a slightly better dose distribution in the target volume ( P=0. 046 ) , but a slightly higher dose to lung tissue ( V25 and V30 , P=0. 007 and 0. 026) . Conclusions The optimal initial parameters of a VMAT plan for cervical and upper esophageal cancer are a collimator angle of 45°, a maximum delivery time of 80 s, and a gantry angle of 3°.
4.Establishment, evaluation, and determination of saliva glucose concentration by ion chromatography
Chun XU ; Qian DOU ; Shiwen WANG ; Zifeng ZHANG ; Qing DAI
Chinese Journal of Endocrine Surgery 2021;15(1):61-65
Objective:To establish an analytical method for measuring the concentration of glucose in saliva by ion chromatography.Methods:The proteins in saliva were removed by thermal denaturation method, CarboPac PA20 (3×30 mm) was used as a protective column and CarboPac PA20 (3×150 mm) was used as an analytical column for ion chromatography analysis. Gradient elution was carried out with A: ultra-pure water, B: 250 mmol/L NaOH solution and C: 500 mmol/L NaAc solution. Pulsed ampere detector was used for detection.Results:This method had a good linear relationship in the range of 0.04 to 0.12 mg/L, with a linear relation coefficient of 0.9967. The detection limit of glucose was 2 μg/L, the mean value of the relative standard deviation (RSD) of the repeatability measurement was 0.75%, and the average spike recovery was 103.07%.Conclusion:This method is simple, sensitive, accurate and stable, and can be used for the determination of glucose concentration in saliva.
5.Studies on Optimal Process for Active Compounds of Flos Datura by Microwave-assisted Extraction
Tuohua PENG ; Zifeng ZHAO ; Shaojun ZHANG ; Xianglan HUANG ; Fan ZENG
Journal of Guangzhou University of Traditional Chinese Medicine 2001;0(03):-
【Objective】To optimize the process conditions for active compounds of Flos Datura by microwave-assisted extraction.【Methods】Uniform design was used to observe the effects of microwave power,microwave radiation time,solvent volume,soaking time and extracting time on the extraction of dry extract,total alkaloids,scopolamine of Flos Datura.The contents of total alkaloids and scopolamine of Flos Datura were determined by acid stain colorimetry and HPLC,and the obtaining rate of dry extract was measured by weight method.【Results】 The optimal process conditions for Flos Datura were as follows: soaking the medicinal material for 2 hours with 10 times of 75% alcohol,with continuous radiation for 25 min at the power of 730 W,at 65℃.【Conclusion】Microwave-assisted extraction is superior to soaking extraction method in increasing productivity and economizing the solvent.
6.Comparison of holmium laser enucleation and plasmakinetic enucleation of the prostate for benign prostatic hyperplasia
Zifeng WANG ; Hong ZHANG ; Qun YANG ; Zhong HUANG ; Xinqi ZHANG ; Xinhui NIU ; Yanqing XIANG
Clinical Medicine of China 2015;31(9):831-834
Objective To evaluate and compare the efficacy of holmium laser enucleation of the prostate(HoLEP) and plasmakineticenucleation of the prostate(PKEP) for treating benign prostatic hyperplasia (BPH).Methods A total of 86 cases of BPH were selected from the Shandong Energy Zibo Mining Group Co.Ltd Central Hospital from January 2013 to June 2014.The patients received either HoLEP (40 cases) or PKEP(46 cases) treatment.Clinical data including postvoid residual volume (PVR),international prostate symptom score(IPSS),quality-of-life score(QOL score),maximum urinary flow rate (MFR) were evaluated before and 3 months after operation.Blood loss in operation,operation time,weight of resected prostate tissue,bladder irrigation time,catheterization time and length of hospital stay were also collected from the perioperative period.Results Three months after surgery,PVR,IPSS,QOL and MFR were all significantly improved in both HoLEP and PKEP groups compared with the data before operation (P =0.000),while there was no significant difference between the two groups(P>0.05).Patients from the HoLEP group showed markedly lower values of bone loss in operation than that of PKEP group((69.5±23.6) ml vs.(87.5±38.0) ml,P=0.011).There were no significant differences in terms of other indexes (P> 0.05).Conclusion HoLEP and PKEP have similar efficiency in treating BPH,while HoLEP is suggested superior in regard of bone loss.
7.Effect of phosphorylated-P38 MAPK on caspase-3 expression in substantia nigra of the MPTP mouse model of Parkinson's disease
Zifeng WEI ; Yongsheng WANG ; Qian WANG ; Liren MA ; Zuofeng ZHANG ; Junling GAO ; Yuxin ZHANG
Basic & Clinical Medicine 2010;30(1):54-58
Objective To investegate the effect of phosphorylated-P38 MAPK(mitogen-activated protein kinase) on the expression of caspase-3 in the substania nigra (SN) of MPTP-induced mouse model of(PD). Methods Mice were randomly divided into MPTP model group, which were treated with MPTP and inhibitor group. Once a day for 5 days; control group was treated with saline and DMSO as much as the model group received per day for 5 days. The behavioral were observed, immunohistochemistry and Western blot for TH, caspase-3 and phosphorylation of P38 MAPK were used to observe the change of positive cell number and the expression level in the SN of midbrain. Results Compared with the mice in control group, the model group showed typical symtoms of PD with decreased numbers of TH-positive neurons and the protein level of TH in SN of the midbrain by about 60% and 65% respec-tively(P<0.01) , the numbers of caspase-3 and phosphorylation of P38 MAPK immunoreactive cells and their protein level in the SN of the midbrain increased markedly (P<0.01). After giving SB203580, the above changes were reduced obviously (P <0. 01). Conclusion In the mouse model of subacute Parkinson's disease induced by MPTP, phosphorylated-P38 MAPK regulated caspase-3 in the SN of midbrain, the specific P38 MAPK inhibitor SB203580 is neurologically oprotective to the mouse model.
8.Effects of Ginseng Aqueous Extract on Neurochemicals in Diabetic Encephalopathy Rat Brain by Online Microdialysis-LC-MS/MS
Qianqian WANG ; Jing ZHANG ; Zifeng PI ; Shu LIU ; Fengrui SONG ; Zhiqiang LIU
Chinese Journal of Analytical Chemistry 2014;(7):997-1001
To evaluate the effects of ginseng aqueous extract on learning and memory abilities and neurochemicals in diabetic encephalopathy rat brain. Diabetes mellitus model was established. Cognitive abilities were evaluated with Morris water maze test by the indexes of escape latency time ( ELT) , times of passing through the target area and the percent of swimming track in goal quadrant. We applied online MD-LC-MS/MS method to determine eight neurochemicals in rat hippocampus among different groups in MRM mode. Venusil C18 column was used for separation. Treatment with ginseng aqueous extract significantly improved the cognitive abilities of diabetic rats (p<0. 05). The method had excellent linearity (R2>0. 99). The accuracy and precision could meet the analysis requirement. Comparing with the model group, the concentrations of taurine and acetylcholine were significantly increased ( p<0 . 01 ) after treated with ginseng aqueous extract, but the glutamic acid, aspartic acid,γ-aminobutyric acid, serine, dopamine and serotonine decreased dramatically. Ginseng aqueous extract can efficiently regulate the levels of eight neurochemials in diabetic rat brain to normal.
9.Dosimetric study of two intensity-modulated arc radiotherapy in esophageal cancer
Ruohui ZHANG ; Xiaomei FAN ; Wenwen BAI ; Runxiao LI ; Yankun CAO ; Chun HAN ; Zifeng CHI
Journal of International Oncology 2014;41(10):785-788
Objective Comparing the dosimetric characteristics of volumetric modulated arc therapy (VMAT) and constant dose rate intensity modulated arc therapy (IMAT) in esophagus cancer to evaluate the performance of the two different arc therapy delivery techniques.Methods 22 cases of esophageal cancer patients were selected for the planning comparison study.All plans were done for IMAT and VMAT treatment plans on Oncentra 4.1 treatment planning system,prescription dose of 2 Gy in total 30 fractions.Planning objectives for PTV were at least 95% reached the prescription dose and V110 no more than 10%.The maximum dose of spinalcord below 45 Gy and double lung dose V20 ≤ 28%,V30 ≤ 18% were constrained.Plans were evaluated based on the ability to meet the dose volume histogram.The dose homogeneity index (HI),radiation conformity index (CI),radiation delivery time,monitor units and γ pass rate were also compared.SPSS 19.0 software paired ttest analysis was carried out on the two sets of data.Results The results showed that the IMAT plans in terms of the PTV's CI (t =3.35,P=0.003),D2(t =-2.27,P=0.034) lung's V30(t =-2.46,P=0.023) were better than that of VMAT group.But the VMAT plans spinal's V40 (t =2.37,P =0.027),lung's V5 (t =2.43,P =0.024) were superior to that of IMAT plans.There were no significant differences between IMAT and VMAT plans in the average dose of PTV,CTV,GTV,heart,spinal cord,double lung and the γpass rate.Conclusion IMAT presents a slight improvement in the OAR sparing in high dose with shorter treatment time when compared to VMAT.While in terms of delivered MU and tissue of low dose irradiated area is higher than that of in VMAT.These two treatment methods all can meet the clinical demand,which should be selected according to the actual situation of the patient.
10.Analysis of electron beam output factors by Monte Carlo method
Zifeng CHI ; Dan LIU ; Yong ZHANG ; Runxiao LI ; Zhonghao JING ; Feng FENG ; Chun HAN
Chinese Journal of Radiation Oncology 2014;23(3):265-268
Objective To investigate the application of the Monte Carlo dose calculation of output factors for electron beams in radiotherapy.Methods The code EGS4/MCTP was used to simulate the head of a medical linear accelerator (Varian 23EX) to calculate the output factors for 6 MeV,9 MeV and 18 MeV electron beams.The source-to-surface distance used was 100 cm.The field sizes ranged from 2 cm × 2 cm to 25 cm × 25 cm.The calculated output factors agreed with the corresponding measured factors which were measured by the IBA Phantom system to within 2%.Then,the output factors of direct articles and indirect articles which were under different energy and various cone-insert combinations were calculated by the code EGS4/MCTP.Results The calculated output factors agreement with the measurements is found to be mostly under the 1% level.The variation of output factors depends on the characteristics of the beams and the modifications that the various cone-insert combinations introduce to these characteristics.Conclusions Monte Carlo dose calculations for electron beams in homogeneous water phantoms have been demonstrated to be accurate under the 1% level in comparison with measurements.The output factors were influenced by energy and cone-insert combinations in complex ways.