Objective
To investigate the effect of hepatocyte growth factor (HGF) on the barrier function of retinal peigment epithelium (RPE) and to detect the pathological mechanism of retinal detachment (RD) induced by over expression of HGF in RPE.
Methods
Sub-retina injection of E1/E3deleted adenoviral vectors encoding HGF (Ad CMV.HGF) and green fluorescent protein (Ad CMV.GFP) in adult pigmented rabbits [5times;104 plaque-forming units (pfu)/eye] to set up the model of retinal detachment. The ocular fundus and pathological changes were observed 3, 7, 14, and 28 days after injection. The expression level of HGF in retina and vitreous body was detected by immunohistochemistry and enzyme linked immunosorbent assay (ELISA).
Results
In the control eyes injected with AdCMV.GFP, expression of GFP only detected in RPE monolayer. The eyes injected with AdCMV.HGF had b HGF immune positive action in RPE cells at the injection site. The expression level of HGF in vitreous body reached the peak 7 days after injection and decreased to the basic level 28 days after injection. Chronic RD and chronic choroidal inflammation were found in the eyes injected with AdCMV.HGF within the time frame of HGF expression. Proliferative RPE cells were found in subretinal space in the region of RD, and multilayered cellular membranes developed in some eyes.
Conclusion
Over expression of HGF in RPE may induce chronic serous RD with subretinal proliferation of RPE, which suggests that HGF should be further studied as a target for therapeutic intervention in RD.
(Chin J Ocul Fundus Dis, 2007, 23: 193-197)
ObjectiveTo study the local vascular remodeling, inflammatory response, and their correlations following acute spinal cord injury (SCI) with different grades, and to assess the histological changes in SCI rats.MethodsOne hundred and sixteen adult female Sprague Dawley rats were randomly divided into 4 groups (n=29). The rats in sham group were received laminectomy only. A standard MASCIS spinal cord compactor was applied with drop height of 12.5, 25.0, or 50.0 mm to establish the mild, moderate, or severe SCI model, respectively. Quantitative rat endothelial cell antigen 1 (RECA1) and CD68 positive areas and the correlations were studied by double immunofluorescent (DIF) staining at 12 hours, 24 hours, 3 days, 7 days, and 28 days following SCI. Moreover, qualitative neurofilament-H (NF-H) and glial fibrillary acidic protein (GFAP) positive glial cells were studied by DIF staining at 28 days. ELISA was used to detect the levels of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-6 in spinal cord homogenates at 12 hours, 24 hours, and 3 days, and the correlations between TNF-α, IL-1β, or IL-6 levels and microvascular density (RECA1) were accordingly studied. Moreover, the neural tissue integrity and neuron damage were assessed by HE staining at 12 hours, 24 hours, 3 days, 7 days, and 28 days, and Nissl’s staining at 28 days following SCI, respectively.ResultsDIF staining revealed that the ratio of RECA1 positive area was the highest in moderate group, higher in mild and severe groups, and the lowest in sham group with significant differences between groups (P<0.05). The ratio of CD68 positive area was the highest in severe group, higher in moderate and mild groups, and the lowest in sham group with significant differences between groups (P<0.05), except the comparisons between mild and moderate groups at 24 hours and 28 days after SCI (P>0.05). There was no significant correlation between the RECA1 and CD68 expressions in sham group at different time points (P>0.05). At 12 and 24 hours after SCI, the RECA1 and CD68 expressions in mild and moderate groups showed significant positive correlations (P<0.05), while no significant correlation was found in severe group (P>0.05). No significant correlations between the RECA1 and CD68 expressions was shown in all SCI groups at 3 days and in severe group at 7 days (P>0.05), while the negative correlations were shown in mild and moderate groups at 7 days, and in all SCI groups at 28 days (P<0.05). In mild, moderate, and severe groups, the axons became disrupted, shorter and thicker rods-like, or even merged blocks with increased injury, while the astrocytes decreased in number, unorganized and condensed in appearance. ELISA studies showed that TNF-α, IL-1β, and IL-6 levels in sham group were significantly lower than those in other 3 groups at different time points (P>0.05). The differences in TNF-α, IL-1β, and IL-6 levels between SCI groups at different time points were sinificant (P<0.05), except IL-1β levels between the mild and moderate groups at 12 hours (P>0.05). Three inflammatory factors were all significantly correlated with the microvascular density grades (P<0.05). Histological analysis indicated that the damage to spinal cord tissue structure correlated with the extent of SCI. In severe group, local hemorrhage, edema, and infiltration of inflammatory cells were found the most drastic, the grey/white matter boundary was disappeared concurrently with the formation of cavity and shortage of normal neurons.ConclusionIn the acute stage following mild or moderate SCI, progressively aggravated injury result in higher microvessel density and increased inflammation. However, at the SCI region, the relation between microvessel density and inflammation inverse with time in the different grades of SCI. Accordingly, the destruction of neural structures positively relate to the grades of SCI and severity of inflammation.
Objective
To establish the three-dimensional (3D) finite element model of the knee joint including posterolateral complex (PLC), and to simulate the reconstruction biomechanical analysis in this model.
Methods
The knee of a 26-year-old healthy man was scanned by MRI to obtain the image data of the knee in the coronal, sagittal, and axial position. First, Mimics10.01 and Hyperworks 8.0 softwares were used to extract each slice profile data of the knee joint in a two-dimensional image data respectively and to establish 3D geometric model of bone, meniscus, articular cartilage, and ligament. Second, Unigraphics software NX 4.0 was used to establish a 3D finite element model of knee joint, which had the functions of Mesh, material properties, component connection, and contact definition. Third, displacement measurement on the model and reconstructing biomechanical analysis for PLC simulation were performed.
Results
The 3D finite element model of the knee joint including PLC was established successfully. Under 134 N forward force, the tibia forward displacement was 4.83 mm. PLC simulation reconstruction biomechanical analysis of the 3D finite element model of the knee joint showed that under 10 N·m varus and external rotation torque conditions, the knee varus and external rotation angles of simulation reconstruction were greater than those of the intact knee, and less than those of PLC missing.
Conclusion
The 3D finite element model of the knee joint including PLC can be established by the reverse engineering, and it is valid and can be used as the basis for the biomechanical properties to analog reconstruction of PLC.
The choice of genetic models was main difficulty in the meta-analysis of gene-disease association studies. In this study, we made a further discussion about the genetic model-free approach that proposed by Minelli et al. The program that coded by JAGS and R was carried out to perform the Bayesian procedure. In a real example, several kinds of prior distribution were used, including non-informative prior distribution and external clinical prior information. Especially, compared to Minelli’s study, we introduced clinical prior information. The results indicated that the pooled results were rather robust no matters the prior distribution were non-informative or informative, especially when the number of included studies were large.
Abstract: The hybrid pencil beam model (HPBM) is an effective algorithm for calculating electron dose distribution in radiotherapy. The mean energy distribution of incident electron beam in phantom is one of the factors that affect the calculation accuracy of HPBM, especially in field edge areas near the end of the electron range. A new fitted formula based on Monte Carlo (MC) simulation data for electron beams with energy range of 6-20MeV in the homogeneous water phantom is proposed in this paper. The precision of the fitted formula within the scope of the energy was evaluated by comparing the electron dose distribution of ECWG measured data with that obtained from HPBM which took the mean electron energy that calculated by the fitted formula and the existed empirical formula, respectively. The results showed that the accuracy of dose distribution that obtained by the mean electron energy calculated with the fitted formula increased about 1%.
Objective To diversify the methods of human physiology teaching for medical students at Chang Gung University College of Medicine. Methods We divided the grades of semester evaluation for physiology into two parts: 70% for lecture-examinations, 30% for non-examination-associated learning model including oral presentation of a scientific paper (conference), problem-based learning (PBL) performance, and quizzes. Results By a questionnaire survey at the end of the semester, we found that students were willing to spend time preparing non-examination-associated learning model; and from their own evaluations, the effectiveness of non-examination-associated learning was comparable to lecture-examination methods. Conclusion We conclude that from this analysis of students’ learning attitude and actual time (in hours per week) spent in each learning models, non-examination-associated learning model is well accepted and appeares to be as effective as traditional examination-forced study.
Objective
To observe the pathological and functional changes of retinal photochemical damages exposed to green flurescent light.
Methods
The Sprague Dawley rats were continually exposed to green fluorescent light with an illuminancem level of (1 900plusmn;106.9) Lx for 24 hours.The changes of retinal morphology and morphometrics and flash electroretinogram were studied before light exposure and at the 6th hour,6th day and 14th day after light exposure.
Results
At the 6th hours after light exposure,the outer nuclear layer(ONL)of retina becoma thinner compared with that bfore light exposure.The thickness of ONL decreased by 23.91% and the inner and outer segments appeared disorderly arranged.At the 6th day after light exposure the thickness of ONL is thinner than that at the6th hour,i.e.decreased by 46.6%. At the 14th day after light exposure the thickness of ONL decreased by 42.40%.Flash electroretinogram showed that the amplitudes of a and b wave decreased continuously at the 6th hour and 6th day and unrecovered at the 14th day after light exposure.
Conclusion
This model might be an ideal one for research on retinal photochemical damage.
(Chin J Ocul Fundus Dis,1998,14:101-103)
Objective To conduct a systematic review of the construction methods, predictive factors, and model quality of risk prediction models for postoperative chronic pain in knee replacement surgery patients, providing evidence for the development of nursing-sensitive dynamic prediction models. Methods A systematic review of risk prediction models for postoperative chronic pain in knee replacement surgery patients was conducted by searching PubMed, Web of Science, Cochrane Library, CINAHL, SinoMed, CNKI, Wanfang Database, and VIP Database. The search period was from the establishment of the databases to February 28, 2025. Two researchers independently screened the literature, extracted data, and assessed the risk of bias and applicability of the included studies. Results A total of 10 studies involving 10 predictive models were included in this review. Among these, three models underwent internal validation, and one model underwent external validation. Commonly reported predictive factors included postoperative 24-hour Numerical Rating Scale scores, postoperative knee function scores, sleep disorders, preoperative depression, postoperative functional exercises, postoperative complications, preoperative pain, and postoperative C-reactive protein levels. All 10 studies had a high risk of bias and were generally applicable. Conclusions Existing risk prediction models generally rely on static indicators and lack dynamic monitoring of postoperative rehabilitation behaviors and psychosocial factors, with severe deficiencies in model validation. Future research should focus on developing nursing-led multidimensional dynamic models that incorporate functional exercise adherence data collected via wearable devices, standardize external model validation, and enhance clinical translation value.
Objective To analyze the influencing factors of hospitalization costs of obstructive hydronephrosis and explore the optimal grouping of diagnosis-intervention packet (DIP), so as to provide a basis for hospitals to strengthen the cost control of diseases, improve the level of refined management, and improve the compensation mechanism of DIP expenses by medical insurance departments. Methods The homepage data of medical records of Pingshan District People’s Hospital of Shenzhen City from January 2019 to December 2021 were collected, and the information of the discharged patients with the International Classification of Diseases-10th revision code as N13.2 was selected. The factors affecting hospitalization costs were analyzed by single factor analyses and multiple stepwise linear regression, the main surgical methods, number of other operations, and influencing factors of expenses were used as classification nodes, and the decision tree model was used to group and predict costs. Results A total of 1319 patients were included, the median inpatient expense was 10889.59 yuan, and the interquartile range was 10943.89 yuan. The case classification, days of hospitalization, condition of admission, whether it was hospitalized for the first time, whether clinical pathway was implemented, the way of discharge, the number of other diagnoses, and admission path were important factors affecting the inpatient expenses, and 12 groups of case mixes and corresponding expense standards were formed. The reduction in variance was 86.10%, the maximum coefficient of variation was 0.33, and the cost analysis ratio was 96.25%. Conclusions Combining the DIP grouping principle and the multi-factor grouping strategy of diagnosis-related groups, the grouping of obstructive hydronephrosis cases constructed by decision tree model is reasonable and the cost standard is close to reality. The case mixes and cost criteria can provide data support and decision-making reference for hospitals and medical insurance institutions.
Objective To explore the effect of oxygen inhalation on the retinae of newborn rats and its mechanism.Methods We mimicked the retinopathy of prematurity(ROP) by putting the newborn rats in high concentrated oxygen. One-day old rats were put into the oxygen box with the oxygen concentration of 80% for continuous 7 days; then in air condition for 7 days. The arterial blood oxygen pressure, retinal superoxide dismutase (SOD), and malondialdehyde (MDA) of the rats (1,2,4,7,8,9,11,14 days old) were examined. The diameter of retinal vessels′main branch and the coverage rate of peripheral vessels were measured in 7- and 14-day-old rats by ink perfusion. The retinal neovascularization of rats (8,9,11, 14 days old) were observed by HE staining. The rats of the same age fed in air condition were in the control group.Results The differential pressures of blood oxygen of rats (1,2,4,7 days old) in study group were significantly higher than those in the control group (P＜0.01), while the differential pressures of blood oxygen of rats (8,9,11,14 days old) in study group were lower than those in the control group (P＞0.05). The contents of SOD of the retinae in the rats ( 1,2,4,7,8 days old) were significantly lower than those in the control group(P＜0.01, P＜0.05 ), while the contents of MDA were significantly higher than those in the control group (P＜0.01,P＜0.05). The diameter of retinal vessels′main branch in 7-day rats was 75% of the control group, and the coverage rate of peripheral vessels was 22% of the control group; and was 61% and 73% respectively in 14-day-old rats. The neovascularization could be seen in 16.7% of the rats in the study group and nought in the control group.Conclusion The damage of free radical of the retina in high concentrated oxygen and hypoxia situation after oxygen supply may be one of the most important mechanism of ROP. (Chin J Ocul Fundus Dis，2003，19：269-332)
