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 observe the morphological characteristics of internal carotid artery (ICA) siphon and ophthalmic artery (OA) in patients with non-arteritic anterior ischemic optic neuropathy (NAION) based on CT angiography (CTA) three-dimensional reconstruction of ICA siphon and OA models. MethodsA retrospective cohort study. From January 2017 to January 2019, 26 patients with 31 eyes (NAION group) who were diagnosed with NAION by ophthalmic examination at Beijing Friendship Hospital, Capital Medical Universitywere included in the study. Among them, there were 11 males with 13 eyes, and 15 females with 18 eyes; the age was 67.52±6.30 years old. Nineteen eyes of 19 non-affected contralateral eyes were selected as the contralateral eye group. Among them, there were 9 males with 9 eyes and 10 females with 10 eyes; the age was 65.95±5.66 years old. Twenty-six eyes of 26 age- and sex-matched subjects with normal fundus examination during the same period were selected as the normal control group. All subjects underwent best corrected visual acuity (BCVA), intraocular pressure, fundus photography and CTA examination. The data obtained from CT scans were reconstructed by 3D model, and the anatomical morphology of ICA siphon was divided into U-shape, V-shape, C-shape and S-shape; the diameter of ICA siphon portion and the diameter at the beginning of OA were measured. One-way analysis of variance was used to compare the diameter of the OA at the beginning of the OA and the diameter of the ICA siphon between the three groups of eyes. ResultsThe diameters at the beginning of OA in the NAION group, the contralateral eye group, and the normal control group were 1.17±0.20, 1.34±0.17, and 1.39±0.15 mm, respectively, and the differences among the three groups were statistically significant (F=12.325, P<0.05); there was no significant difference between the contralateral eye group and the normal control group (P=0.310). In the NAION group, the anatomical morphology of the ICA siphon was U-shaped and V-shaped in 20 (64.52%) and 8 (25.81%) eyes respectively, and S and C-shaped in 3 eyes (9.67%); in the contralateral eye group, in the control group, the ICA siphon shape of the eyes examined was U-shaped and V-shaped, and S-shaped and C-shaped were rare. The diameters of the ICA siphons in the NAION group, the contralateral eye group, and the normal control group were 3.50±0.69, 3.22±0.59, and 3.55±0.54 mm, respectively. There was no significant difference between the three groups (F=1.860, P=0.163). ConclusionU-shaped and V-shaped ICA siphons are more common in NAION-affected eyes; the diameter of the starting point of OA is significantly reduced.
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 a model for studying on mechanical responses of osteoblasts seeded in 3 dimensional(3D) scaffold. Methods Fifty pieces of bioderived cancellous bones, whose holes were 500 to 800 μm and density was 0.36 to 0.45g/cm3, were obtained as the scaffolds. They were cultured with the third passage suspension of Wistar rat. Twenty-four of the 50 scaffolds were constructed under apparent strain sine waveform with amplitude of 1 000 με, frequency of 3 Hz, and duration of 3 min/d, as experimental group. The other scaffolds were control group. After 3day coculture, osteoblasts were observed with scanning electron microscope. The proliferation of the osteoblasts was checked by MTT on scheduled date. Results Scanning electron microscopic observation showed that osteoblasts ttached and spread on the trabeculae, which presented the validity of the model under proper mechanical condition. Experiment showed that mechanical environment promoted theproliferation of osteoblasts. The observation of proliferation of osteoblasts showed that the quantity of osteoblasts in the experimental group was higher than that in the control group 1,4,8,12,16,20,24, and 28 days after culturing. Therewas significant difference between the two groups 12,16,20,24,and 28 days afterculturing(P＜0.05). Conclusion The establishment of the model can facilitate the study of mechanical responses of osteoblasts under different conditions.
Objective To systematically review the pharmacoeconomic evaluation related to relapsed or refractory B-cell acute lymphoblastic leukemia (r/r B-ALL), and to summarize its model structure, parameter inclusion and other methodological parts for future r/r B-ALL-related interventions, and to provide references for conducting pharmacoeconomic evaluations. Methods PubMed, EMbase, The Cochrane Library, CNKI and WanFang Data databases were electronically searched to collect relevant literature on the pharmacoeconomic evaluation model of r/r B-ALL from inception to August 6th, 2021. Two reviewers independently screened literature, extracted data, and assessed the quality of the included studies. The data on the model structure, methods, and parameter inclusion were then summarized. Results A total of 10 studies using different modeling methods were included. Due to the lack of head-to-head trials, most of the efficacy parameters for the intervention and control groups were derived from different clinical trials and compared indirectly. All studies used quality-adjusted life years (QALYs) as output indicators, and some used life years (LYs) as output indicators and reported the incremental cost effectiveness ratio (ICER). All studies measured the cost of treatment and hematopoietic stem cell transplantation; a few studies also conducted subgroup analysis. Conclusion The number of studies on the economic evaluation of r/r B-ALL is relatively small, and there are large differences in model types, health status, and parameter inclusion. It is suggested that researchers should guarantee the integrity of the report format and normative according to available data choice drug economics evaluation model and establish the reasonable hypothesis under the condition of the patient population heterogeneity uncertainty, perform subgroup analysis especially on the subgroup which did not receive salvage therapy. In the absence of head-to-head clinical trials, appropriate indirect comparison methods are adopted according to the data obtained to reduce methodological differences and improve the quality of relevant pharmacoeconomic research in China.
ObjectiveTo establish a model of portal hypertension with hypersplenism in SD rats by portal vein binding combined with splenic vein ligation. MethodsSixty healthy male SD rats were randomly divided into three groups: sham operation group （only laparotomy, n=20）, portal vein binding group (only binding, n=20), and portal vein binding combined with splenic vein ligation group (combined operation group, n=20). The counts of platelet, erythrocyte, and leukocyte were examined just before operation and once a week after operation for 7 weeks. Portal pressure, shortaxis, and longaxis diameter of spleen were examined just before operation and seven weeks after operation. At the seventh week, all the animals were sacrificed, spleen index and pathology changes of each group were examined. ResultsErythrocyte and platelet counts in combined operation group were significantly lower than those in the other two groups on the third week （Plt;0.05）, and there was no significant difference in leukocyte count among three groups （Pgt;0.05）. Compared with the preoperative value, portal pressure increased significantly on the seventh week in both portal vein binding group and combined operation group, and was higher than that in the sham operation group （Plt;0.05）. The two diameters of spleen also increased significantly in combined operation group on the seventh week （Plt;0.05）, and were larger than those in the other two groups （Plt;0.05）. The same result was found in spleen index （Plt;0.05）. Typical pathological changes of hypersplenism presented only in combined operation group on the seventh week after operation. ConclusionsPortal vein binding combined with splenic vein ligation can induce experimental secondary hypersplenism successfully. This procedure is simple and stable, and helpful to the scientific research.
Meditation aims to guide individuals into a state of deep calm and focused attention, and in recent years, it has shown promising potential in the field of medical treatment. Numerous studies have demonstrated that electroencephalogram (EEG) patterns change during meditation, suggesting the feasibility of using deep learning techniques to monitor meditation states. However, significant inter-subject differences in EEG signals poses challenges to the performance of such monitoring systems. To address this issue, this study proposed a novel model—calibrated multi-source adversarial adaptation network (CMAAN). The model first trained multiple domain-adversarial neural networks in a pairwise manner between various source-domain individuals and the target-domain individual. These networks were then integrated through a calibration process using a small amount of labeled data from the target domain to enhance performance. We evaluated the proposed model on an EEG dataset collected from 18 subjects undergoing methamphetamine rehabilitation. The model achieved a classification accuracy of 73.09%. Additionally, based on the learned model, we analyzed the key EEG frequency bands and brain regions involved in the meditation process. The proposed multi-source domain adaptation framework improves both the performance and robustness of EEG-based meditation monitoring and holds great promise for applications in biomedical informatics and clinical practice.
This study introduced the construction of individualized risk assessment model based on Bayesian networks, comparing with traditional regression-based logistic models using practical examples. It evaluates the model's performance and demonstrates its implementation in the R software, serving as a valuable reference for researchers seeking to understand and utilize Bayesian network models.
Objective To clarify the most important factors affecting the survival of patient with gastric carcinoma. Methods 428 cases of resected gastric carcinoma were studied by using univariate analyses and multivariate regression analyses. Results The most significant factors influencing survival of these patients were peritoneal dissemination, Borrmann classification, type of operation, hepatic metastasis, size of tumor, location, lymph node metastasis and age. Conclusion The factors influencing survival in patient with gastric carcinoma after resection can be correctly analyzed by cox’s proportional hazard model.
This article introduces the exploration and establishment of “grass-roots Party building + targeted poverty alleviation” model by the Party Branch of Emergency Department of West China Hospital of Sichuan University, and discusses how to establish the “trinity mode” of management support, personnel training, and on-site guidance under the leading of grass-roots Party building through a series of the branches combined activities, according to the core idea of “strengthening the Party construction, bringing people closer together, and promoting development”. The aim is to form a long-term mechanism of grass-roots Party building and targeted medical poverty alleviation through continuously implementing this model, which can benefit more people in remote and ethnic minority areas and contribute to “Healthy China 2030”.
