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find Keyword "Models" 11 results
  • Validation of Four Different Risk Stratification Models in Predicting Early Death of Chinese Patients after Isolated Coronary Artery Bypass Grafting Surgery

    Abstract: Objectives To evaluate the accuracy of four existing risk stratification models including the Society of Thoracic Surgeons(STS) 2008 Cardiac Surgery Risk Models for Coronary Artery Bypass Grafting (CABG), the European System for Cardiac Operative Risk Evaluation (EuroSCORE), the American College of Cardiology/American Heart Association (ACC/AHA) model, and the initial Parsonnet’s score in predicting early deaths of Chinese patients after CABG procedure. Methods We collected clinical records of 1 559 consecutive patients who had undergone isolated CABG in the Fu WaiHospital from November 2006 to December 2007. There were 264 females (16.93%) and 1 295 males (83.06%) with an average age of 60.87±9.06 years. Early death was defined as death inhospital or within 30 days after CABG. Calibration was assessed by the Hosmer-Lemeshow (H-L) test, and discrimination was assessed by the receiveroperatingcharacteristic (ROC) curve. The endpoint was early death. Results Sixteen patients(1.03%) died early after the operation. STS and ACC/AHA models had a good calibration in predicting the number of early deaths for the whole group(STS: 12.06 deaths, 95% confidence interval(CI) 5.28 to 18.85; ACC/[CM(159mm]AHA:20.67deaths, 95%CI 11.82 to 29.52 ), While EuroSCORE and Parsonnet models overestimated the number of early deaths for the whole group(EuroSCORE:36.44 deaths,95%CI 24.75 to 48.14;Parsonnet:43.87 deaths,95%CI 31.07 to 56.67). For the divided groups, STS model had a good calibration of prediction(χ2=11.46, Pgt;0.1),while the other 3 models showed poor calibration(EuroSCORE:χ2=22.07,Plt;0.005;ACC/AHA:χ2=28.85,Plt;0.005;Parsonnet:χ2=26.74,Plt;0.005).All the four models showed poor discrimination with area under the ROC curve lower than 0.8. Conclusion The STS model may be a potential appropriate choice for Chinese patients undergoing isolated CABG procedure.

    Release date:2016-08-30 05:57 Export PDF Favorites Scan
  • Protective effects of recombinant erythropoietin on photoreceptor cells in rat with retinal detachment

      Objective To investigate the protective effect of recombinant erythropoietin (EPO) on the photoreceptor cells in rat with retinal detachment (RD).Methods One hundred and sixtytwo normal male rats were randomly divided into normal control (NC) group, RD model group, RD+phosphate buffer solution (RD+PBS) group, RD+EPO 100 ng group, RD+EPO 200 ng group and RD+EPO 400 ng group. Three days after RD, activated caspase3 and bclXL were detected by Western blot and/or immunofluorescence, and apoptosis were measured by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate digoxigenin nick-end labeling(TUNEL). Fourteen and 28 days and two months after RD, the outer nuclear layer (ONL)thickness was measured by histopathologic method.Results Western bolt indicated that the protein level of activated caspase-3 and bcl-XL between six groups were statistically significant(F=35.96, 30.75;P<0.01). The number of TUNEL positive cells and activated caspase-3 positive cells are consistent with each other in different groups. Fourteen days and two months after RD,the differences of ONL thickness between six groups were statistically significant(F=21.52,96.25;P<0.01).Conclusion Supplement of EPO after RD can alleviate apoptosis by inhibiting of the caspase-3 activity and increasing the expression of bcl-XL,thus exerts protective effect on photoreceptor cells.

    Release date:2016-09-02 05:41 Export PDF Favorites Scan
  • 应用液压冲击颅脑损伤仪建立大鼠外伤性视神经损伤动物模型

    Objective To observe whether the animal model of optic nerve injury in rats can be set up by fluid percussion brain injury device (FPI) or not.Methods Seventyone healthy female Wister rats were randomly divided into 2 groups, inlcuding model group with 66 rats and control group with 5 rats.The rats in model group were randomly divided into 3 groups. Eight rats in group 1 were examined by flashvisual evoked potential (F-VEP) and magnetic resonance imaging (MRI) examines before and 1, 3 days,1,2,4,6,and 8 weeks after injury; 56 rats in group 2 were randomly divided into 7 subgroups with 8 rats in each subgroup,and were detected by histopathological and terminal deoxynucleotidyl transferasemediated dUTP nick end labeling (TUNEL) apoptosis examines 1, 3 days, 1,2,4,6,8 weeks after injury;2 rats in group 3 were examined by electron microscopy 4 and 8 weeks after injury.According to the degree of injury, the injured eyes were divided into 2 groups including severe injury group with the beat pressure of (699.14plusmn;60.79) kPa and mild injury group with the beat pressure of (243.18plusmn;20.26) kPa.The right and left eyes in rats in each group were in severe and mild injury group, respectively.Results One day after injury, the latency duration of FVEP prolonged in severe injury group,wich differed much form which in the normal control group (P<0.05);the amplitude was gradually reduced during the first 2 weeks after injury and kept steady after that (P>0.05). The latency duration prolonged in mild injury group,and its difference with the normal control group was statistically significant (P<0.05);the amplitude was gradually reduced during the first 4 weeks after injury and kept steady after that (P>0.05). The abnormal high signal could be seen on optic nerve 1 day after injury, and was still obvious 8 weeks later. The results of histopathological examination showed ruptured capillary in ganglion cell layer 1 day after injury;retinal ganglion cells without nucleus could be seen 4 weeks after injury. The apoptosis of positive cells was found in each layer of the retina 3 days after injury.TUNEL results indicated that the number of apoptotic positive cells increased significantly 1-2 weeks after injury.Conclusion An animal model of optic nerve injury can be successfully set up using FPI in rats.

    Release date:2016-09-02 05:42 Export PDF Favorites Scan
  • Experimental study on photodynamic induced anterior ischemic optic neuropathy in rat animals

    Objective To establish an rat model of the Anterior Isc hemic Optic Neuropathy (rAION), and identify its reliability by observing the fundus, fluorescein fundus angiography (FFA),optical coherence tomography (OCT), v isually evoked potential (VEP) and histopathology. Methods Thirty male Sprague-Dawley rats were randomly divided into group Naive with 5 rats, group Laser with 5 rats, group hematoporphyrin derivative(HPD) with 5 rats, group rAION with 15 rats. All of the right eyes were the experimental eyes and the left ones were the control. after administration of HPD in rats` vena caudalis. The rats in group Laser were treated with a krypton red 647nm/2/3disc spot laser for 120 seconds, the rats in group HPD were treated by administration of HPD in rats` vena caudalis, and the rats in group Na?ve were not treated. Results From 1 day to 6 day s after rAION induction, the ON was pale and swollen in the superior part. The ON at 90 days after induction was pale and shrunken.30 minutes after rAION induction, hyperfluoresc ence appeared in the superior part of the optic disc, and the hypofluorescence in the 23rd day. In early FFA, hypofluorescence appeared at the ischemic area of the optic disc, and in midst and later stage the ischemic area revealed hyperflu orescence in the 1st day after rAION induction, the hypofluorescence in midst and later stage in the sixth day after r-AION model. The latent period of F-VEP expanded. The amplitude cut down in the 1-2 days after r-AION induction and did not changed in 35nd day. The surface of optic disc showed higher and rougher tha n the surface of retina in the 6th day after r-AION induction in OCT. After fixation and hematoxylineosin staining of 6-mu;m sections, in high power field the o pt ic disc showed edema with the displacement of retina surrounding the disc 1 day after treatment. Rarefaction and degeneration in the nerve fiber of retina and r eduction of the number of nuclei of ganglion cells in the 23st day after the mod el induction, and the thinning of nerve fiber of the optic disc and its surround ings. In contrast, there was no change in group Na?ve, group Laser and group HPD. Conclusions The r-AION model is like the human AION in fundus, FFA, OCT, VEP and histopathology. The rAION model provides the ischemic changes of occurrence of AION, and is helpful for the fundamental study of the AION. (Chin J Ocul Fundus Dis,2008,24:90-94)

    Release date:2016-09-02 05:46 Export PDF Favorites Scan
  • Expression of interleukin18 and signal transducers and activators of transcription 5 in retina of diabetic rats

    ObjectiveTo investigate the expression of interleukin-18(IL-18)and signal transducers and activators of transcription 5(STAT5)in retina of 4-24-week-old diabetic rats, and explore the potential molecular mechanisms involved in diabetic retinopathy (DR).MethodsRetinal gene expression profile of healthy and 8-week-old diabetic rats was established with restriction fragment differential displaypolymerase chained reaction (RFDD-PCR), and the differences was analyzed by bioinformatics. IL-18 and STAT5 were filtrated as the candidate genes of DR. The expression of IL-18 and STAT5 in retina of diabetic rats with the age of 4, 8, and 24 weeks was observed by semi-quantitative reverse transcriptase-polymerase chain reaction(RT-PCR).ResultsThe result of RFDD-PCR showed:expression of IL-18 was higher in healthy retina than that in diabetic one; expression of STAT5 was not found in healthy rats but in diabetic ones. The result of RT-PCR showed:compared with the normal, high expression of IL-18 was found in 4-week diabetic retina, reduced in 8-week one, and decreased to the lowest in 24-week one. The expression of STAT5 was not observed in healthy or 4week diabetic retina, but occurred in 8-week one, and increased in 24-week one. ConclusionThe expression of IL-18 and the activation of STAT5 may relate to the occurrance of DR. The expression of IL-18 doesn′t depend on the activation of STAT5. (Chin J Ocul Fundus Dis, 2005,21:258-260)

    Release date:2016-09-02 05:52 Export PDF Favorites Scan
  • Experimental study of limited macular translocation

    Objective By using a newly developed animal model of limited macular translocation (LMT) in rabbit eyes, to explore the complications,indications and predictability of LMT. Methods LMT models were performed in 15 rabbit eyes, and were divided into 4.5 mm group and 3.5 mm group by the length of scleral shortening.The effect of retinal translocation (distance and direction) and its complications were analyzed. In a separated group, postoperative corneal astigmatism was studied after release of scleral shortening suture 1 month after LMT. In order to study the impact of neuroretina-retinal pigment epithelium (RPE) adhesion on LMT, retinas and choroids in 4 pigmented rabbit eyes were pretreated with photocoagulation. Results Success rate of LMT was 86.7%. In these cases, retinal translocations were achieved[(distance of 610 to 2690 μm, [AKx-]±s=(1395±636)μm; translocation angle α of 10-38°, [AKx-]±s=(22.7±8.3) °]. The difference in scleral shortening between 4.5 mm and 3.5 mm groups did not significantly influence the final translocation. Major complications of LMT included intraocular bleeding, retinal break, and corneal astigmatism. Release of scleral shortening suture reduced corneal astigmatism and made it more regular, meanwhile, retinal translocation did not regress. The neuroretina-RPE adhesion induced by retinal photocoagulation made neuroretinal hydrodissection difficult, and led to retinal break readily. Conclusion Sufficient LMT models in rabbit eye were obtained with few postoperative complications. Direction of retinal translocation is an important factor influencing the effect of LMT, except for distance. Release of scleral shortening suture can effectively reduce corneal astigmatism without causing regression of retinal translocation. For the patients with a history of macular or para-macular photocoagulation, LMT should be performed carefully. (Chin J Ocul Fundus Dis, 2002, 18: 203-207)

    Release date:2016-09-02 06:01 Export PDF Favorites Scan
  • Application of Micron Ⅳ retinal imaging system in three different types of mouse models

    ObjectiveTo evaluate Micron Ⅳ retinal imaging system in three mouse models of retinal diseases. MethodsMouse models of oxygen induced retinopathy (OIR) model (OIR group), N-methyl-N nitrosourea (MNU) model (MNU group) and N-methyl-D-aspartate (NMDA) model (NMDA group) were induced in 24 healthy male C57BL/6J mice. Fundus photograph, fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) and electroretinogram (ERG) were used to evaluate these mice. All the imaging examinations were performed by Micron Ⅳ retinal imaging system. ResultsOIR mice showed tortuous and dilated retinal vessels in fundus photograph, neovascularization plexus and vascular leakage in FFA, and epiretinal fibrovascular tissue and tortuous expansion vascular vessels in OCT. MNU mice showed wax yellow optic disk without retinal pigmentary changes, slight thinning of retinal blood vessels in FFA, and normal structure and thickness in OCT. The a-wave amplitudes of the maximum mixed response decreased significantly, and were (15.38±4.36) μV and (13.78±5.52) μV at 2 or 3 days of modeling, respectively. NMDA mice showed a pale retina with vasospasm. ERG revealed that there was no obvious change in latency of a- and b-wave, but significantly decreased amplitude of b-wave at 12 hours and 24 hours after modeling with (72.28±7.18) μV and (65.35±9.18) μV, respectively. ConclusionMicron Ⅳ retinal imaging system is a real-time, non-invasive tool to study the retinal structure and function in animal models of retinal diseases.

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  • The establishment and preliminary verification of a risk model for the prediction of diabetic retinopathy in patients with type 2 diabetes

    Objective To establish a risk prediction model of diabetic retinopathy (DR) for type 2 diabetic patients (T2DM). Methods A total of 315 T2DM patients (600 eyes) were enrolled in the study. There were 132 males (264 eyes) and 183 females (366 eyes). The mean age was (67.28±12.17) years and the mean diabetes duration was (10.86±7.81) years. The subjects were randomly assigned to model group and check group, each had 252 patients (504 eyes) and 63 patients (126 eyes) respectively. Some basic information including gender, age, education degree and diabetes duration were collected. The probable risk factors of DR including height, weight, blood pressure, fasting glucose, glycosylated hemoglobin (HbA1c), blood urea, serum creatinine, uric acid, triglyceride, total cholesterol, high-density lipoprotein, low density lipoprotein cholesterol and urinary protein. The fundus photograph and the axial length were measured. Multivariate logistic regression was used to analyze the correlative factors of DR and establish the regression equation (risk model). Receiver operating characteristic (ROC) curves were used to determine the cut-off point for the score. The maximum Youden Index was used to determine the threshold of the equation. The check group was used to check the feasibility of the predictive model. Results Among 504 eyes in the model group, 170 eyes were DR and 334 eyes were not. Among 126 eyes in the check group, 45 eyes were DR and 81 eyes were not. Multivariate logistic regression analysis revealed that axial length [β=–0.196, odds ratio (OR)=0.822,P<0.001], age (β=-0.079,OR=0.924,P<0.001), diabetes duration (β=0.048,OR=1.049,P=0.001), HbA1c (β=0.184,OR=1.202,P=0.020), urinary protein (β=1.298,OR=3.661,P<0.001) were correlated with DR significantly and the simplified calculation of the score of DR were as follows:P=7.018–0.196X1–0.079X2+0.048X3+0.148X4+1.298X5 (X1= axial length, X2=age, X3=diabetes duration, X4=glycosylated hemoglobin, X5= urinary protein). The area under the ROC curve for the score DR was 0.800 and the cut-off point of the score was -1.485. The elements of the check group were substituted into the equation to calculate the scores and the scores were compared with the diagnostic threshold to ensure the patients in high-risk of DR. The result of the score showed 84% sensitivity and 59% specificity. ROC curve for the score to predict DR was 0.756. Conclusion Axial length, age, diabetes duration, HbA1c and urinary protein have significant correlation with DR. The sensitivity and specificity of the risk model to predict DR are 84.0% and 59.0% respectively. The area under the ROC curve was 0.756.

    Release date:2017-05-15 12:38 Export PDF Favorites Scan
  • The establishment and preliminary verification of a risk model for the prediction of diabetic retinopathy in patients with type 2 diabetes

    ObjectiveTo establish an appropriate diabetic retinopathy (DR) risk assessment model for patients with type 2 diabetes mellitus (T2DM).MethodsA retrospective clinical analysis. From January 2016 to December 2017, 753 T2DM patients in the Third Affiliated Hospital of Southern Medical University were analyzed retrospectively. Digital fundus photography was taken in all patients. Fasting plasma glucose (FPG), HbA1c, total bilirubin (TB), blood platelet, total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-c), low density lipoprotein cholesterol (LDL-c), apolipoprotein-A (apoA), apolipoprotein-B (apoB), serum creatinine, blood urea nitrogen (BUN), blood uric acid, fibrinogen (Fg), estimated glomerular filtration (eGFR) were collected. The patients were randomly assigned to model group and testify group, each had 702 patients and 51 patients respectively. Logistic regression was used to screen risk factors of DR and develop an assessment scale that can be used to predict DR. Goodness of fit was examined using the Hosmer-Lemeshow test and the area under the receiver operating characteristic (ROC) curve.ResultsAmong 702 patients in the model group, 483 patients were DR, 219 patients were NDR. The scores for DR risk were duration of diabetes ≥4.5 years, 4 points; total bilirubin <6.65 mol/L, 2 points; apoA≥1.18 g/L, 2 points; blood urea≥6.46 mmol/L, 1 points; HbA1c ≥7.75%, 2 points; HDL-c<1.38 mmol/L, 2 points; diabetic nephropathy, 3 points; fibrinogen, 1 point. The area under the receiver operating characteristic curve was 0.787. The logistic regression analysis showed that the risk factors independently associated with DR were duration of diabetes (β=1.272, OR=3.569, 95%CI 2.283−5.578, P<0.001), TB (β=0.744, OR=2.104, 95%CI 1.404−3.152, P<0.001, BUN (β=0.401, OR=1.494, 95%CI 0.996−2.240, P=0.052), HbA1c (β=0.545, OR=1.724, 95%CI 1.165−2.55, P=0.006), HDL-c (β=0.666, OR=1.986, 95%CI 1.149−3.298, P=0.013), diabetic nephropathy (β=1.151, OR=3.162, 95%CI 2.080−4.806, P=0.013), Fg (β=0.333, OR=1.396, 95%CI 0.945−2.061, P=0.094). The risk model was P=1/[1+exp−(−3.799+1.272X1+0.744X2+0.769X3+0.401X4+0.545X5+0.666X6+1.151X7+0.333X8)]. X1= duration of diabetes, X2=TB, X3=apoA, X4=BUN, X5=HbA1c, X6=HDL-c, X7=diabetic nephropathy, X8=Fg. The area under the ROC curve was 0.787 and the Hosmer-Lemeshow test suggested excellent agreement (χ2=10.125, df=8, P=0.256) in model group. The area under the ROC curve was 0.869 and the Hosmer-Lemeshow test suggested excellent agreement (χ2=5.345, df=7, P=0.618) in model group.ConclusionThe area under the ROC curve for DR was 0.787. The duration of diabetes, TB, BUN, HbA1c, HDL-c, diabetic nephropathy, apoA, Fg are the risk factors of DR in T2DM patients.

    Release date:2019-03-18 02:49 Export PDF Favorites Scan
  • Establishment and research progress of retina ischemic animal model

    Retinal ischemia is the common pathologic process in many ophthalmic diseases, including ischemic optic neuropathy, retinal artery and vein occlusion, carotid artery obstructive disease, retinopathy of prematurity, chronic diabetic retinopathy and glaucoma. It is very important to establish animal models to investigate pathology mechanism and explore the treatment of retinal ischemia disease. At present, the commonly used methods for establishing retinal ischemia animal models include increasing intraocular pressure, ligating of blood vessels, suture method, photochemical method, and drug injection etc. This article summarizes the methods to establish the animal models and analyzes the indication for each animal model. It is expected that the method of establishing a retinal ischemic animal model will be helpful to the experimental design of follow-up retinal ischemia studies.

    Release date:2021-06-18 01:57 Export PDF Favorites Scan
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