【Abstract】 Objective To investigate both incidence and mechanism attributing to steroid-associated osteonecrosisof femoral head(ONFH) using an experimental protocol with a single low-dose l i popolysaccharide (LPS) injection andsubsequently three injections of high-dose methylprednisolone (MPS). Methods Twenty-five New Zealand white rabbits with body weight of (3.0 ± 0.3) kg were divided randomly into 2 groups. In treatment group, 19 rabbits received one intravenous injection of LPS (10 μg/kg); 24 hours later, three injections of 20 mg/kg of MPS were given intramuscularly at an interval of 24 hours. Additional 6 rabbits which received normal sal ine injection at the same time point were used as controls(control group). The blood samples were collected for hematological examinations before and after LPS injection, MRI was performed on bilateral hip six weeks after last MPS injection, meanwhile, bone marrow was aspirated from femoral head region to evaluate stem cell’s activity. Bilateral femoral heads were harvested to make histopathology examination. Results All animals survived throughout the experiment period except one death on the second day after LPS injection. In the histopathological examinationfor the femoral head, ONFH+ was observed in 16 rabbits (88.9%), and the lesions were mainly in the metaphysis. In ONFH+ rabbits, micro vessels fibrous thrombosis and extravascular marrow fat cell size increasing were found around necrotic bone; The femoral heads of control group had no changes. MRI accurate ratio was 93.8% (15/16). Compared to basel ine, a significant decrease in ratio of tissue plasminogen activator/plasminogen activator inhibitor 1 and activated partial thromboplatin time, and a significant increase in ratio of low-density l ipoprotein/high-density l ipoprotein were only found in ONFH+ rabbits (P lt; 0.05). Meanwhile there was a significant decrease in the number of CFU-F (8.50 ± 9.63) compared with the control (70.17 ± 7.78, P lt; 0.05). Conclusion A single low-dose LPS injection and subsequent three injections of high-dose MPS is effective on building steroid-associated ONFH model, coagulation and l ipometabol ism abnormal ity, activity degeneration of stem cell may be the key factors of ONFH.
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.
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)
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 hematoxylineosin 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)
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)
【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.
According to different experimental methods of induced diabetic retinopathy (DR) and different characteristics of the observed retinopathy, DR animal models can be divided into drug or dietary-induced models, oxygen-induced retinopathy (OIR) models, spontaneous inheritance models, and transgenic models. At present, induced model is one of the most commonly used animal model for DR study, which has the advantages of short modeling cycle, low cost, simple experimental operation and good repeatability. However, the drugs have certain side effects on various organs of animals and the risk of animal death is higher. OIR model has good repeatability, good stability and relatively low cost. However, due to the lack of metabolic changes of hyperglycemia in OIR mice, this model cannot accurately reflect the effects of metabolism on retina under hyperglycemia. The pathological changes of the spontaneous model are relatively stable, however, the application of this model is limited because the genetic homogeneity of diabetes differs from that of human and the cost is high. Transgenic model has definite etiology, however, its application is limited owing to the high cost and the high requirements of technology, operation and equipment. Therefore, researchers should comprehensively consider characteristics and limitations of different models while choosing suitable DR model based on research objectives, observation indicators, experimental conditions, and funds. In addition, animal models that can more accurately simulate DR need to be developed to provide more effective tools for studying the mechanism of DR and developing feasible prevention and treatment approaches.
ObjectiveTo systematically review the risk prediction models for readmission within 30 days after discharge in patients with chronic obstructive pulmonary disease (COPD), and provide a reference for clinical selection of risk assessment tools. MethodsDatabases including CNKI, Wanfang Data, VIP, CBM, PubMed, Embase, Web of Science, and Cochrane Library were searched for literature on this topic. The search time was from the inception of the database to April 25, 2023. Literature screening and data extraction were performed by two researchers independently. The risk of bias and applicability of the included literature were evaluated using the risk of bias assessment tool for predictive model studies. ResultsA total of 8 studies were included, including 14 risk prediction models for 30-day readmission of COPD patients after discharge. The total sample size was 125~8 263, the number of outcome events was 24~741, and the area under the receiver operating characteristic curve was 0.58~0.918. The top five most common predictors included in the model were smoking, comorbidities, age, education level, and home oxygen therapy. Although five studies had good applicability, all eight studies had a certain risk of bias. This is mainly due to the small sample size of the model, lack of reporting of blinding, lack of external validation, and inappropriate handling of missing data. ConclusionThe overall prediction performance of the risk prediction model for 30-day readmission of patients with COPD after discharge is good, but the overall research quality is low. In the future, the model should be continuously improved to provide a scientific assessment tool for the early clinical identification of patients with COPD at high risk of readmission within 30 days after discharge.
OBJECTIVE: To investigate a animal model of spinal cord injury in different degrees of impact. METHODS: A new weight-drop device was designed with the character of controlled degree of impact and time. After thirty-five rats underwent different degrees of impact, their motor function and pathological changes were observed. RESULTS: In control group, the rats could walk after reviving, and the micro-structure of spinal cord was normal. With 0.5 mm depth of impact, the rats also could walk, and the micro-structure of spinal cord did not change obviously. With 0.8 mm depth of impact, the rats could walk after several days of injury and only slight damage could be found in spinal cord. When the impact depth increased to 1.0 or 1.5 mm, the rats were paralyzed completely and could not walk after four weeks of injury. Severe injury was observed in spinal cord. CONCLUSION: This animal model of spinal cord injury is based on different degrees of impact. It has stable and repetitive characters for the research on spinal cord injury.
Objective To establish and modify a rat model of arterialized small-for-size orthotopic liver transplantation and investigate the histopathologic changes of the grafts after transplantation. Methods Modified two-cuff technique was applied to establish a rat model of 40% small-for-size orthotopic liver transplantation with a modified microvascular “sleeve” anastomosis between the celiac trunk of donors and the stump of right kidney artery of recipients. Seven days survival rate was observed, main indices of liver function, histopathologic changes of the grafts were detected on the 1st, 2nd, 4th and 7th day after transplantation, respectively. Results The successful rate of operation was 93.3%. Seven days survival rate was 60.0%. The mean time of nonhepatic time was (12.0±2.5) min. Alanine aminotransferase (ALT) and total bilirubin (TB) began to elevate on the first day and peaked on the second day after operation. Histological findings indicated that hepatic sinusoidal and central vein dilation, monocytes infiltration in partial area were found on the 1st day after operation, more diploid and polyploid hepatocytes could be observed on the 4th day after operation. Conclusion The model is easily available and highly reproducible, and the stability of the model is improved by modifying the technique. The histological changes of the grafts are mainly caused by ischemia-reperfusion injury.
