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 displaypolymerase 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 4week 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)
Objective To establish the reliable model of hepatocirrhosis with portal hypertension. Methods Carbon tetrachloride was subcutaneous injected after devascularization of the circumference of the left renal vein. The morphology of liver, the extrahepatic portal system and portcaval collateral circulation were observed. Results The liver of rats underwent degeneration and necrosis of hepatocytes, and the normal architecture of the liver lobules was replaced by pseudolobules, which consisted of regenerative hepatocytes and fibrous septa. After 5 weeks, the portal pressure was significantly higher than that of control (Ｐ＜0.05). The diameter of esophageal vein was significantly larger than that of control at 15th week (Ｐ＜0.05). Conclusion This technique is simple and reliable and can be applied for various experimental studies on portal hypertension.
Objective To report an acute ischemic left ventricular heart failure model of safe, simple, relatively steady, and reproducible in sheep. Methods Fourteen female sheep with a body weight of 36.80±3.43kg were used in this study. Heart failure model was induced by partial occluding the middle left circumflex coronary artery （LCX） combined with pacemaker-induced tachycardia. Hemodynamic measurement was done before and after heart failure, myocardial examination was observed. Results Heart failure model was induced successfully in 10 sheep. Cardiac output dropped from 3.74±0.48L/min to 2.02±0. 51L/min （P〈0. 01）, mean arterial pressure decreased from 116. 10± 14.15 mmHg（1kPa = 7.5mmHg） to 68. 10± 14. 72mmHg （P〈0.01）, central venous pressure rose from 7. 10±2.18mmHg to 10. 70± 3.50 mmHg （P〈0.05）, right ventricular end-diastolic pressure increased from 6.10±3.57mmHg to 9.90±4.41mmHg（P〈0.05）, left atrial pressure increased from 8.10±2.13 mmHg to 12.00± 4.57mmHg （P〈0. 01 ）, and left ventricular end-diastolic pressure increased from 8. 50± 4. 17mmHg to 13.10± 10. 64mmHg（P〉 0. 05）. The myocardial ultrastructure injuries was marked. Conclusions Acute ischemic left ventricular heart failure could be induced by partial occlusion of the middle LCX combined with pacemaker-induced taehyeardia in sheep. This model is simple, easy to manipulate, relatively steady, and reproducible . It may be used for assessing cardiac assist devices.
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.
ObjectiveTo develop and modify a rat model of partial liver transplantation with hepatic arterialization and to investigate the postoperative histopathologic changes of the grafts. MethodsModified twocuff technique was applied to establish a rat model of partial liver transplantation, and the donor’s celiac artery was anastomosed with the recipient’s right renal artery. The biopsy of the grafts was performed on the day 1,2,4 and 7 after transplantation. Results85.4% of the recipients had survived for one week.Nuclear mitoses were seen on the postoperative day 2 by microscopy, while on the day 4 they were found occasionally. Two nucleus cells were seen on the day 4 and 7. Conclusion The stability of the model is improved by modifying the technique. Liver acupuncture biopsy is a simple, safe and feasible way to be applied in the research of postoperative problems of liver transplantation. Reconstruction of hepatic artery is possible to enhance the regeneration of liver grafts.
Objective To establish a new model on isolated human cadaver testes with ischemiareperfusion (I/R). MethodsThirteen isolated cadaver testes contributed by 13 persons were preserved under 0℃-4℃ hypothermia and then reperfused under 37℃. Histological and histochemical changes were observed. Results4℃ cold ischemia in 12 hours induced only trivial swelling and vascular degeneration of endothelial cells (ECs), obvious pathologic changes occurred after 24 hours, including detachment of ECs, separation between basement membrane and seminiferous epithelium, degeneration and detachment of spermatogenous cell and edema of mesenchyme. Injury was worse along with the prolongation of cold preservation time. Changes of LDH and SDH activities were found by histochemical staining. Reperfusion following 6 hours ischemia induced tissue injury and unusual enzyme activity. All changes were more obvious after reperfusion following 12,18,24 or 36 hours cold ischemia.Conclusion This new model on isolated cadaver testes with ischemiareperfusion is successful, it can substitute other solid organs of human beings for I/R injury study.
【Abstract】Objective To introduce the birth and development of model of endstage liver disease (MELD) and evaluate its effect on liver transplantation(LT) as a new scoring system. Methods Literatures of MELD applied in LT were analyzed retrospectively. Results MELD scoring system was used for predicting the prognosis of patients with endstage liver disease and the death risk of candidates on waiting LT extensively and the order of organ sharing was determined by its predicable results. Conclusion MELD has been had a successful initial implementation for predicting the shortterm survival probability and mortality in patients with endstage liver disease, and meeting the goal of providing a system of allocation that emphasizes the urgency of the candidate while diminishing the reliance on waiting time, which has been proven to be a powerful tool for auditing the liver allocation system.
A acute partial obstructive hepatocholangitis model by selective ligation and injection of E coli into left hepatic bile duct was successfully founded in rat. Using parameters including mortality, mitochondrial glutamic oxalacetic transaminase and ornithine carbamoytransferase activity, pathological observation and blood culture of bacteria, we evaluated the model. The authors emphasize that this models is superior to the wole-bile-duct-challenged cholangitis model, which is characterized by liver injury.
Without artificial airway though oral, nasal or airway incision, the bi-level positive airway pressure (Bi-PAP) has been widely employed for respiratory patients. In an effort to investigate the therapeutic effects and measures for the respiratory patients under the noninvasive Bi-PAP ventilation, a therapy system model was designed for virtual ventilation experiments. In this system model, it includes a sub-model of noninvasive Bi-PAP respirator, a sub-model of respiratory patient, and a sub-model of the breath circuit and mask. And based on the Matlab Simulink, a simulation platform for the noninvasive Bi-PAP therapy system was developed to conduct the virtual experiments in simulated respiratory patient with no spontaneous breathing (NSB), chronic obstructive pulmonary disease (COPD) and acute respiratory distress syndrome (ARDS). The simulated outputs such as the respiratory flows, pressures, volumes, etc, were collected and compared to the outputs which were obtained in the physical experiments with the active servo lung. By statistically analyzed with SPSS, the results demonstrated that there was no significant difference (P > 0.1) and was in high similarity (R > 0.7) between the data collected in simulations and physical experiments. The therapy system model of noninvasive Bi-PAP is probably applied for simulating the practical clinical experiment, and maybe conveniently applied to study the technology of noninvasive Bi-PAP for clinicians.