Objective: To compare the biomechanical basis of 3 different internal fixation methods: nitinol patellar concentrator (NT-PC), tension band and wire circle in treating patellar fractures. Methods: The epoxy resin thre...Objective: To compare the biomechanical basis of 3 different internal fixation methods: nitinol patellar concentrator (NT-PC), tension band and wire circle in treating patellar fractures. Methods: The epoxy resin three dimensional photoelasticity patellar models were made by precise moulding, and were fixated by nitinol patellar concentrator (NT-PC), tension band and wire circle respectively. The patellar models with frozen stress stripes were put into the polarized light field and the stress distributions were compared. As for the model fixated by NT-PC, by dividing layer, photographing and tracing, we used the iterative method to calculate the stress value of every internal node of the epoxy resin patellar model, and the character of stress was analyzed. Results: An overall stress field was yielded when the patellar model was fixated by NT-PC, and the stripes were more than that of tension band model and wire circle model, which have only few stress stripes in the fixated layers. Further analysis indicated that there were continuous fixated stresses in the facies articularis and distal pole of patella, and the character of stresses produced by NT-PC were mainly in longitudinal direction, then in transverse direction. The shearing stresses were small. Conclusion: The initiative and continuous memorial stress of NT-PC and its overall stress distribution character are the essence of NT-PC distinguished with tension band and wire circle in treating patellar fractures. The stress character produced by NT-PC is good for the stability of fracture site and prompts fracture healing.展开更多
Background Digoxin remains widely used today despite its narrow therapeutic index and toxicity. The objective of this study was to investigate the percentage of inappropriate use of digoxin and long-term outcomes of e...Background Digoxin remains widely used today despite its narrow therapeutic index and toxicity. The objective of this study was to investigate the percentage of inappropriate use of digoxin and long-term outcomes of elderly patients hospitalized for digoxin toxicity. Methods The study included 99 consecutive patients hospitalized for digoxin toxicity. The other study criteria for the inappropriate use of digoxin was regarded if participants having depressed left ventricular systolic function （ejection fraction 〈 45%） who were not on optimal medical therapy including beta-blocker and angiotensin-converting-enzyme inhibitor therapy or if participants having permanent AF who were not on optimal beta-blocker therapy. Results Appropriate digoxin usage was confirmed in 33 of patients in spite of its narrow therapeutic index. A total of 16 of 99 patients died, with a mean follow-up time of 22.1 ± 10.3 months. Conclusions Contrary to popular belief, the rate of inappropriate digoxin usage remains high. On account of its narrow therapeutic index and toxicity, digoxin should be used more carefully according to the current evidence and guidelines.展开更多
Background Although angiotensin converting enzyme inhibitors （ACEI） and angiotensin receptor blockers （ARB） are equally important in the treatment of hypertension, there is less evidence whether they have equal ca...Background Although angiotensin converting enzyme inhibitors （ACEI） and angiotensin receptor blockers （ARB） are equally important in the treatment of hypertension, there is less evidence whether they have equal cardiovascular and cerebrovascular protective effects, especially in elder hypertensive patients. This study aims to clarify this unresolved issue. Methods This cross-sectional study included clinical data on 933 aged male patients with hypertension who received either an ARB or ACEI for more than two months between January 2007 and May 2011. The primary outcome was the composite of cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke. The secondary endpoints were unstable angina, new atrial fibrillation, and transient ischemic attack. Results The median follow-up time was 24 months. Age, drug types, cerebral infarction history, renal dysfunction history were the independent predictors of the primary endpoint. The risk of an occurrence of a primary endpoint event was higher in the ARB group than the ACEI group [P = 0.037, hazard ratios （HR）： 2.124, 95% confidence interval （95% CI）： 1.048-4.306]. The Kaplan-Meier method also suggests that the rate of primary endpoint occurrence was higher in the ARB group than the ACEI group （P = 0.04）. In regard to the secondary endpoints, there were no significant differences between the two treatment arms （P = 0.137, HR： 1.454, 95% CI： 0.888-2.380）. Patient age and coronary heart disease history were independent predictors of the secondary endpoint. Conclusion ACEI were more effective than ARB in reducing cardiovascular and cerebrovascular morbidity and mortality in aged patients with hypertension.展开更多
Objective Coronary heart disease （CHD） is a multifactorial disease. This meta-analysis was performed to evaluate the relationship between angiotensinogen gene polymorphisms and CHD in the Chinese population. Methods...Objective Coronary heart disease （CHD） is a multifactorial disease. This meta-analysis was performed to evaluate the relationship between angiotensinogen gene polymorphisms and CHD in the Chinese population. Methods We searched literature in pubmed （1990- 2010.8） and CNKI （1990-2010.8） for all the relevant studies on 2 angiotensinogen polymorphisms （M235T and T174M） and risk of CHD. The meta-analysis software Stata 10.0 was used for ascertaining heterogeneity among individual studies and for combining all the studies. Furthermore,Egger＇s test and sensitivity analysis were performed to insure authenticity of the outcome.Results Ten associations studies on 2 angiotensinogen polymorphisms （M235T and T174M） were included in this meta-analysis. In a combined analysis, the summary per-allele odds ratio for CHD of the M235T polymorphism was 1.374 （95% confidence interval, 1.019 to 1.852） and T174M polymorphism was 4.089 （95% confidence interval, 1.697 to 9.851）. Conclusions The M235T polymorphism had weak but statistically significant association with CHD while the T174M polymorphism was more strongly associated with a CHD risk in Chinese population, but further confirmation studies are needed展开更多
文摘Objective: To compare the biomechanical basis of 3 different internal fixation methods: nitinol patellar concentrator (NT-PC), tension band and wire circle in treating patellar fractures. Methods: The epoxy resin three dimensional photoelasticity patellar models were made by precise moulding, and were fixated by nitinol patellar concentrator (NT-PC), tension band and wire circle respectively. The patellar models with frozen stress stripes were put into the polarized light field and the stress distributions were compared. As for the model fixated by NT-PC, by dividing layer, photographing and tracing, we used the iterative method to calculate the stress value of every internal node of the epoxy resin patellar model, and the character of stress was analyzed. Results: An overall stress field was yielded when the patellar model was fixated by NT-PC, and the stripes were more than that of tension band model and wire circle model, which have only few stress stripes in the fixated layers. Further analysis indicated that there were continuous fixated stresses in the facies articularis and distal pole of patella, and the character of stresses produced by NT-PC were mainly in longitudinal direction, then in transverse direction. The shearing stresses were small. Conclusion: The initiative and continuous memorial stress of NT-PC and its overall stress distribution character are the essence of NT-PC distinguished with tension band and wire circle in treating patellar fractures. The stress character produced by NT-PC is good for the stability of fracture site and prompts fracture healing.
文摘Background Digoxin remains widely used today despite its narrow therapeutic index and toxicity. The objective of this study was to investigate the percentage of inappropriate use of digoxin and long-term outcomes of elderly patients hospitalized for digoxin toxicity. Methods The study included 99 consecutive patients hospitalized for digoxin toxicity. The other study criteria for the inappropriate use of digoxin was regarded if participants having depressed left ventricular systolic function （ejection fraction 〈 45%） who were not on optimal medical therapy including beta-blocker and angiotensin-converting-enzyme inhibitor therapy or if participants having permanent AF who were not on optimal beta-blocker therapy. Results Appropriate digoxin usage was confirmed in 33 of patients in spite of its narrow therapeutic index. A total of 16 of 99 patients died, with a mean follow-up time of 22.1 ± 10.3 months. Conclusions Contrary to popular belief, the rate of inappropriate digoxin usage remains high. On account of its narrow therapeutic index and toxicity, digoxin should be used more carefully according to the current evidence and guidelines.
文摘Background Although angiotensin converting enzyme inhibitors （ACEI） and angiotensin receptor blockers （ARB） are equally important in the treatment of hypertension, there is less evidence whether they have equal cardiovascular and cerebrovascular protective effects, especially in elder hypertensive patients. This study aims to clarify this unresolved issue. Methods This cross-sectional study included clinical data on 933 aged male patients with hypertension who received either an ARB or ACEI for more than two months between January 2007 and May 2011. The primary outcome was the composite of cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke. The secondary endpoints were unstable angina, new atrial fibrillation, and transient ischemic attack. Results The median follow-up time was 24 months. Age, drug types, cerebral infarction history, renal dysfunction history were the independent predictors of the primary endpoint. The risk of an occurrence of a primary endpoint event was higher in the ARB group than the ACEI group [P = 0.037, hazard ratios （HR）： 2.124, 95% confidence interval （95% CI）： 1.048-4.306]. The Kaplan-Meier method also suggests that the rate of primary endpoint occurrence was higher in the ARB group than the ACEI group （P = 0.04）. In regard to the secondary endpoints, there were no significant differences between the two treatment arms （P = 0.137, HR： 1.454, 95% CI： 0.888-2.380）. Patient age and coronary heart disease history were independent predictors of the secondary endpoint. Conclusion ACEI were more effective than ARB in reducing cardiovascular and cerebrovascular morbidity and mortality in aged patients with hypertension.
文摘Objective Coronary heart disease （CHD） is a multifactorial disease. This meta-analysis was performed to evaluate the relationship between angiotensinogen gene polymorphisms and CHD in the Chinese population. Methods We searched literature in pubmed （1990- 2010.8） and CNKI （1990-2010.8） for all the relevant studies on 2 angiotensinogen polymorphisms （M235T and T174M） and risk of CHD. The meta-analysis software Stata 10.0 was used for ascertaining heterogeneity among individual studies and for combining all the studies. Furthermore,Egger＇s test and sensitivity analysis were performed to insure authenticity of the outcome.Results Ten associations studies on 2 angiotensinogen polymorphisms （M235T and T174M） were included in this meta-analysis. In a combined analysis, the summary per-allele odds ratio for CHD of the M235T polymorphism was 1.374 （95% confidence interval, 1.019 to 1.852） and T174M polymorphism was 4.089 （95% confidence interval, 1.697 to 9.851）. Conclusions The M235T polymorphism had weak but statistically significant association with CHD while the T174M polymorphism was more strongly associated with a CHD risk in Chinese population, but further confirmation studies are needed
