Preparation and characterization of sustained-release levofloxacin bone tissue-engineered three-dimensional silk fibroin/chitosan/nano-hydroxyapatite scaffold / 中国组织工程研究

BACKGROUND: Preliminary study has prepared the three-dimensional silk fibroin/chitosan/nano-hydroxyapatite scaffold successfully.OBJECTIVE: To explore the mechanical properties, physical characteristics, chemical composition and antibiotic sustained-release ability of three-dimensional silk fibroin/chitosan/nano-hydroxyapatite scaffold loaded with levofloxacin. METHODS: Levofloxacin/chitosan (3:1) microspheres were constructed by emulsion settlement filter method. 5, 7.5 and 10 g of microspheres were added into 2％ of silk fibroin/chitosan/nano-hydroxyapatite mixed solution through freeze drying and chemical cross-linking to obtain the scaffolds loaded with antibiotics. The scaffolds loaded with antibiotics underwent scanning electron microscope observation, and chemical composition analysis. The sustained release, mechanical properties, porosity, water absorption expansion rate and hot water soluble loss rate were detected. RESULTS AND CONCLUSION: (1) Scanning electron microscope observed that there were drug microspheres at the inner wall of the scaffold, and the voidage was decreased with mass of microspheres increasing. (2) Energy spectrum analysis showed that the three kinds of scaffolds were rich in calcium and phosphonium ions. (3) The three kinds of scaffolds showed the same releasing trend, which presented with sudden-release effect at the former 3 days (release> 50％) , and then tended to be stable. The release rate was the slowest in the scaffold loaded with 10 g of microscopes, and the rapidest in the scaffold loaded with 5 g of microscopes. (4) With the mass of microspheres increasing, there was an increase in the compressive and tension abilities and hot water soluble loss rate, and a decrease in the porosity, mean pore size and water absorption expansion rate. (5) These results indicate that the three-dimensional tissue-engineered scaffold loaded with levofloxacin is constructed successfully by freeze drying and chemical cross-linking method, which holds good sustained-release effect and compressive ability, water absorption expansion rate and hot water soluble loss rate.

Expression of ELMO1 in Hepatocellular Carcinoma and its Effects on Cell Migration / 现代医院

Objective To investigate the expression of engulfment and cell motility protein 1 (ELMO1) in hepatocellular carcinoma(HCC) and its effects on cell migration.Methods The expression of ELMO1 in HCC cell lines and HCC tissues was assessed by Western blot.We used transient transfection with an ELMO1 expressing vector to over-express ELMO1 protein in SK-HEP-1 cells.Over-expression of ELMO1 was confirmed by Western blot.siRNAs specific to ELMO1 (ELMO1 siRNA) were used to knockdown ELMO1 expression.Rho Family Small GTPase Activation Assay, Western blots, transwell assay were used to determine the migration potential of cells.Student's test was employed for statistical analysis.Results The expression of ELMO1 protein was obviously up-regulated in HCC tissues and cell lines (P<0.05).Over-expression of ELMO1 promoted cell migration in SK-HEP-1 cells, while knock-down of ELMO1 showed the opposite effect.Conclusion ELMO1 up-regulation significantly correlates with cell migration in hepatocellular carcinoma.

The role of central nervous system on hypoglycemia and the feasibility of the brain theory in traditional Chinese medicine on treatment of diabetes mellitus / 中西医结合学报

The central nervous system (CNS) plays a key regulatory role in glucose homeostasis. In particular, the brain is important in initiating and coordinating protective counterregulatory responses when blood glucose levels fall. This may due to the metabolic dependency of the CNS on glucose, and protection of food supply to the brain. In healthy subjects, blood glucose is normally maintained within a relatively narrow range. Hypoglycemia in diabetic patients can increase the risk of complications, such as heart disease and diabetic peripheral neuropathy. The clinical research finds that the use of traditional Chinese medicine (TCM) has a positive effect on the treatment of hypoglycemia. Here the authors reviewed the current understanding of sensing and counterregulatory responses to hypoglycemia, and discuss combining traditional Chinese and Western medicine and the theory of iatrogenic hypoglycemia in diabetes treatment. Furthermore, the authors clarify the feasibility of treating hypoglycemia on the basis of TCM theory and CNS and have an insight on its clinical practice.

Research on the displacement function and equivalent circuit of circular flexural vibration mode piezoelectric ceramic composite transducers.

Flexural vibration mode piezoelectric ceramic transducers can be used in many application fields because of their ability to develop large displacement at low levels of electrical excitation, or conversely, to generate high output from sources of low mechanical impedance. Many flexural transducers are very thin, and their behavior can be analyzed and predicted accurately by the current theory based on thin-plate assumptions. However, for those flexural transducers with moderate thickness, the thin-plate assumptions are no longer valid. To analyze and predict the behaviors of the flexural transducers with moderate thickness, we must establish a new theory. In this paper, by introducing Mindlin's assumptions and theory, the displacement function and equivalent circuit for circular flexural composite transducers with moderate thickness are derived. Through the displacement function and the equivalent circuit, the vibration characteristics and the electrical impedance of circular flexural composite transducers with moderate thickness can be predicted directly.

Relationship between cranial nerve involvement in nasopharyngeal carcinoma and the prognosis / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To analyze the feature of cranial nerve involvement in nasopharyngeal carcinoma (NPC) and its relationship with the prognosis.@*METHOD@#A total of 1892 patients who were diagnosed as NPC in our hospital from January 2002 to December 2003, of which the cranial nerve involvement was 183 (9.6%) patients, were analyzed the effect of cranial nerve involvement on the prognosis.@*RESULT@#The percentage of cranial nerve involvement was 9.4%. The 5 year overall survival rate was 61.0%, disease free survival rate was 55.3%, local relapse free survival rate was 75.2% and distant metastasis free survival rate was 73.4%. Periods of cranial nerve involvement, clinical stage, the diameter of the lymph nodes, involvement of cavernous sinus, and the level of the recovery of cranial nerve involvement were significantly associated with prognosis in univariate analysis(P < 0.05). With multivariate analysis, the recovery level of cranial nerve involvement was the independent factor that affected the 5-year overall survival (RR = 2.087). The diameter of the lymph nodes and involvement of cavernous sinus were the independent factors that affected the 5-year distant metastasis-free survival (RR = 1.954 and 2.136, respectively).@*CONCLUSION@#Periods of cranial nerve involvement and the level of the recovery of cranial nerve involvement were significantly correlated with prognosis. Involvement of cavernous sinus could increase the rate of distant metastasis.

Relationship between cranial nerve involvement in nasopharyngeal carcinoma and the prognosis / 临床耳鼻咽喉头颈外科杂志

Objective:To analyze the feature of cranial nerve involvement in nasopharyngeal carcinoma (NPC) and its relationship with the prognosis.Method:A total of 1892 patients who were diagnosed as NPC in our hospital from January 2002 to December 2003,of which the cranial nerve involvement was 183 (9.6%) patients, were analyzed the effect of cranial nerve involvement on the prognosis.Result:The percentage of cranial nerve involvement was 9.4%. The 5 year overall survival rate was 61.0%,disease free survival rate was 55.3%,local relapse free survival rate was 75.2% and distant metastasis free survival rate was73.4%.Periods of cranial nerve involvement,clinical stage,the diameter of the lymph nodes,involvement of cavernous sinus, and the level of the recovery of cranial nerve involvement were significantly associated with prognosis in univariate analysis(P<0.05).With multivariate analysis,the recovery level of cranial nerve involvement was the independent factor that affected the 5-year overall survival (RR=2.087). The diameter of the lymph nodes and involvement of cavernous sinus were the independent factors that affected the 5-year distant metastasis-free survival(RR=1.954 and 2.136,respectively).Conclusion:Periods of cranial nerve involvement and the level of the recovery of cranial nerve involvement were significantly correlated with prognosis. Involvement of cavernous sinus could increase the rate of distant metastasis.