1.The optimum flow shear stress and the mass transport benefiting for construction of the tissue-engineered bone combining computational fluid dynamics
Deqiang LI ; Kerong DAI ; Tingting TANG ; Xueyan GUO ; Jianxi LU ; Ailing YANG
Chinese Journal of Orthopaedics 2011;31(5):542-548
Objective To explore the optimum flow shear stress and mass transport for the construction of tissue-engineered bone.Methods The β-tricalcium phosphate (β-TCP) scaffolds seeded with human bone marrow-derived mesenchymal stem cells (HBMMSCs) were cultured in perfusion bioreactor.When the same flow rate was applied,the flow shear stress was separately 1×,2× and 3×.When the same flow shear stress was applied,the flow rates were separately 3 ml/min,6 ml/min and 9 ml/min.Cell proliferation was measured by MTT method.The construction of tissue-engineered bone was evaluated by measuring alkaline phosphatase (AKP) activity,secretion of osteopontin (OP) and osteocalcin (OC),and the mineralization of extracellular matrix (ECM).The flow shear stress and the mass transport were obtained using computational fluid dynamics.Results When the flow rate was same,the most cell proliferation was found in 2× group.The AKP activity and secretion of OC was higher in 2× and 3× groups than in those in 1× group.After 28days,the highest amount of mineralization of ECM was found in 3× group.When the flow shear stress was same,the AKP activity was highest in 6 ml/min group.After 28 days,secretion of OC and formation of mineralized ECM was highest in 3 ml/min group.When the flow rate was same,the flow shear stress was separately 0.004-0.007 Pa,0.009-0.013 Pa and 0.013-0.018 Pa.When the flow shear stress was same,the flow rate was separately 0.267-0.384 mm/s,0.521-0.765 mm/s and 0.765-1.177 mm/s.Conclusion When the tissue-engineered bone was constructed,0.013-0.018 Pa flow shear stress and 0.267-0.384 mm/s mass transport velocity could improve the construction of the tissue-engineered bone in vitro.
2.Ultrasound enhances PLGA nanoparticle-mediated gene delivery in vivo
Hai ZHANG ; Ying LI ; Jianxi TANG ; Jun YANG ; Junhui CHEN ; Ying WU
Chinese Journal of Ultrasonography 2011;20(6):533-536
Objective To investigate the feasibility and the efficacy of ultrasound in promoting PLGA nanoparticle-mediated gene transfection in vivo.Methods Prostate cancer cell line PC-3 was used to generate xenografts in nude mice for gene transfection experiment in vivo.GFP plasmid was encapsulated in PLGA-based nanoparticles.Nanoparticles were injected into tumors locally.Two hours later,xenografts were exposed to ultrasound.Xenograft tissues were harvested in different time points to assess the efficiency of gene expression with regard to different parameters of ultrasound. Results PLGA nanoparticle-encapsulated GFP plasmids were readily transfected to PC-3 cells in vivo.A large number of GFP expressing cells were observed after exposed to ultrasound with 1.0 MHz 50% duty factor continuous wave.In comparison,ultrasound exposure with 40% duty factor pulse wave in vivo had low efficacy in terms of GFP expression.No animal death was noticed due to ultrasound exposure.Conclusions Ultrasound exposure can enhance the release of plasmid DNA content delivered by PLGA nanoparticles in vivo,local exposure to ultrasound wave would be used in conjunction with PLGA nanoparticle-mediated targeted delivery to the tissue or organ of interest.
3.A study of effects of impaired glucose tolerance on ventricular remodeling
Jianxi TANG ; Xiufang LIN ; Xiaoming XIE ; Zhijunn ZHOU ; Jian ZHAO ; Lan YAO ; Yusheng ZHENG
Chinese Journal of Internal Medicine 2010;49(10):841-844
Objective To evaluate the effects of impaired glucose tolerance (IGT) on ventricular remodeling. Methods Parameters of every subject including left ventricular mass ( LVM), left ventricular mass index (LVMI), E/A ratio, 75 g oral glucose tolerance test (OGTT), ambulatory blood pressure monitoring(ABPM) data including 24-hour mean systolic blood pressure(mSBP) and 24-hour mean diastolic blood pressure(mDBP) were collected. Then the relationship of IGT and myocardial remodeling related parameters were analyzed. Results The rate of diastolic dysfunction was higher in the IGT combined with hypertensive group(74% ) compared with the hypertensive group( 39% )( x2 = 6. 5, P < 0. 05 ). The rate of diastolic dysfunction was higher in the IGT group( 34% ) compared with the normal group( 10% ) (x2 = 5.2,P <0. 05). The rate of Left Ventricular Hypertrophy (LVH)in the IGT combined with hypertensive group (24%) was higher than the other three groups (Hypertension group 7%, IGT group 0, Normal group 0) (x2 =4.561,P <0.05), and there was no significance between the rest three groups (P >0.05).Stepwise multiple regression showed age and 2 Hours' Postprandial Blood Glucose were independent risk factors of E/A ratio. Conclusions These results suggested that IGT is a possible contributor to left ventricular hypertrophy and diastolic dysfunction, and is one of the histopathology of left ventricular remodeling.
4.The Experimental Research in the Effects of Ultrasonication on Degradation of PLGA Released DNA
Haibo FAN ; Hai ZHANG ; Ying LI ; Yuan ZHANG ; Jianxi TANG ; Junhui CHEN ; Benyi LI
Chinese Journal of Biochemical Pharmaceutics 2014;(1):35-37
Objective To identify the effective results of ultrasound in degradation of polymeric nanoparticles released DNA .Polymeric nanoparticles was made by dehydration of polyacetylglutamicacid (PLGA, polylactic-co-glycolic acid)solution. Method Green Fluorescent Protein (GFP) was enclosed by PLGA. Different kinds of ultrasound mode and different duct cycle and power ones were used to radiate PLGA solution for 90 s, 9 min, 20 min separately after the solution prepared for 2 hrs,then putted the solution on centrifugal machine at 13000 r/m. Using Choloroform to get rid of fat-soluble impurity,then applied nanodrop to survey the releasing rate of DNA. Finally the effect of cell expression were observed by fluorescent microscope. Results The amount of DNA released from PLGA in groups which were exposed to ultrasound were significantly different from the groups which were not exposed to ultrosound. The releasing amount of former groups had upper limitation. The releasing rate was increased with the increment of the irradiation time,frequency of ultrasound;The effect of the DNA releasing and PLGA degradation by continuous-wave irradiation was stronger than pulsed-wave ultrasound. Conclusion Ultrasound can promote the degradation of PLGA, and do help in DNA releasing and expression in vitro.
5.Pyrosequencing of pre-C/BCP mutation in hepatitis B
Lan YAO ; Jiawu SONG ; Zhi XIN ; Xiaofeng LI ; Zhouqing WU ; Jianxi TANG ; Bo GUO ; Bo WU ; Renxu LAI
Chinese Journal of Laboratory Medicine 2008;31(8):860-863
Objective To develop a clinically useful assay for detecting the mutations of HBV pre-C/BCP based on the pyrosequencing and accuracy, reproducibility and reliability of this assay was evaluated. Methods The pyrosequencing primers for HBV pre-C/BCP mutation were designed through the cluster analysis among one hundred HBV gene sequences. After the amplification of the fragment of pre-C/BCP with the template of pre-C/BCP mutation plasmids, the pyrosequencing method for pre-C/BCP detection was initially set up with this standard sample. The accuracy, reliability and reproducibility of the pre-C/BCP pyrosequencing were confirmed through the pre-C/BCP plasmids as a standard sample when compared with Sanger/genechip sequencing method pre-C/BCP pyrosequencing assay was applied for detecting pre-C/BCP mutation types of 60 chnical serum samples in HBV patients. Results The pre-C/BCP mutation detection assay based on pyrosequencing has been established in our study. The coincidence rate between pyrosequencing and Sanger squencing was 100%. The coincidence rate between the result of pyrosequencing and of genechip method was 91.7%. The reproducibility of this assay was 97. 8%. It indicates the pre-C/BCP pyrosequencing is a high-accurate method with, good-reproducibility and high-reliability. And multi-site detection can be achieved by pyrosequencing one time. A rare mutation T1758C was also detected. Conclusion Pyrosequencing for pre-C/BCP mutations assay is high-throughout method for simultaneous detection of multi-site mutation.
6.Micro-particles of bioceramics could cause cell and tissue damage.
Jianxi LU ; Tingting TANG ; Huifeng DING ; Kerong DAI
Journal of Biomedical Engineering 2006;23(1):85-89
We conducted studies to confirm the hypothesis that the cellular damage occurring around implanted biphasic bioceramics could be related to a micro-particles release because of an insufficient sintering. An in vitro cytotoxicity study was performed on four biphasic ceramic (BCP) samples. Without the treatment of extraction medium, a cytotoxicity was observed, although after centrifugation this cytotoxicity disappeared in all samples. (2) Micro-particles of HA, beta-TCP and 40%beta-TCP/60%HA mixture were used for a cell inhibition study. A decrease of cell viability was observed with the increase in particles concentration. At 10000 particles/ cell, the viability and proliferation were completely inhibited. (3) HA, beta-TCP and BCP ceramic granules were implanted in rabbit femoral cavities for 12 weeks. No degradation of HA granules was observed. The degradation was higher for beta-TCP (40%) than for BCP (5%). On the other hand, new bone formation was significantly higher for beta-TCP (21%) and HA (18%) than for BCP (12%). Much more micro-particles were formed around BCP granules than around beta-TCP, and were phagocytosed by macrophages. The release of ceramic micro-particles could be related to the sintering process. BCP ceramics have to be sintered at only 1160 degrees C. Consequently, HA microparticles of BCP ceramic are incompletely sintered and easily released after immersion or implantation. The microparticles could be at the origin of local inflammation and cell damage and could perhaps modify osteogenesis. Particular attention must be paid to this problem with regard to BCP ceramics because of the sintering difficulties of this bioceramic.
Biocompatible Materials
;
adverse effects
;
chemistry
;
Calcium Phosphates
;
adverse effects
;
chemistry
;
Cells, Cultured
;
Ceramics
;
adverse effects
;
chemistry
;
Fibroblasts
;
cytology
;
drug effects
;
Hydroxyapatites
;
adverse effects
;
chemistry
;
Materials Testing
;
Particle Size
;
Prostheses and Implants
;
adverse effects
7.Effects of nerve block anesthesia versus general anesthesia on intertrochanteric fractures in the elderly
Shushan ZHAO ; Zhaohui LI ; Zhe RUAN ; Zhangyuan LIN ; Haitao LONG ; Ruibo ZHAO ; Zhengrong ZHU ; Bangbao LU ; Buhua SUN ; Liang CHENG ; Jianxi ZHU ; Zhaohui TANG ; Yong ZHU
Chinese Journal of Geriatrics 2018;37(12):1348-1351
Objective To retrospectively analyze the effects of nerve block anesthesia versus general anesthesia on intertrochanteric fracture in the elderly. Methods The 104 elderly inpatients undergoing closed reduction and intramedullary nailing for the treatment of femoral intertrochanteric fractures were recruited into this study at Department of Orthopedics ,Xiangya Hospital ,Central South University from January 2015 to June 2017.Medical records were collected and analyzed by SPSS 16.0 or GraphPad Prism 6.0 software. Results A total of 104 patients were divided into general anesthesia group(n= 48 )and nerve block anesthesia group (n= 56 ). There was no statistical difference in the demographic characteristics between the two groups. The changes in heart rate ,maximum changes of systolic/diastolic blood pressures ,and infusion volume during surgery were lower in the nerve block anesthesia group than in the general anesthesia group [(12.7 ± 7.3)vs. (18.1 ± 7.8)beats/min ,(22.5 ± 8.8/12.2 ± 7.5)mmHg vs. (34.3 ± 7.9/21.6 ± 6.6)mmHg ,(792.9 ± 387.0)ml vs. (1 083.0 ± 445.5)ml ,respectively ,t=3.64 ,7.14 ,6.73 ,5.16 ,all P<0.01]. There was no statistically significant difference between two groups in other perioperative data and the number of deaths at three months and one year after surgery. Conclusions As compared with the general anesthesia ,the nerve block anesthesia has less effects on the heart rate ,less maximum changes of systolic and diastolic blood pressures ,and less infusion volume during surgery ,and has no significant increase in postoperative mortality ,which is safe and worthy of further promotion.
8.Comprehensive evaluation of postpartum depression and correlations between postpartum depression and serum levels of homocysteine in Chinese women.
Jianxi HUANG ; Li ZHANG ; Min HE ; Xuelian QIANG ; Xia XIAO ; Shuo HUANG ; Danli ZHANG ; Ming TANG
Journal of Central South University(Medical Sciences) 2015;40(3):311-316
OBJECTIVE:
To investigate whether the level of homocysteine in patients with postpartum depression is associated with depression index.
METHODS:
A total of 43 women with postpartum depression or with potential postpartum depression, who visited the psychological clinic of Maternal and Child Health Hospital of Hunan Province from June, 2012 to April, 2014, were enrolled in this study. They were evaluated by the Edinburgh Postnatal Depression Scale and Hamilton Depression Scale. Chinese Classification of Mental Disorder (the third edition) was used for their diagnosis. The depressive index was calculated by Edinburgh Postnatal Depression Scale, Hamilton Depression Scale, and clinical symptom scores, which was used to assess the level of depressive symptoms. The level of homocysteine in serum was detected by chemoluminescent method. Meanwhile, another 31 women, who visited the hospital without postpartum depression, were used as controls to compare with the 43 patients.
RESULTS:
The homocysteine level in the women with postpartum depression was significantly higher than that in the control group [(10.09 ± 3.59) μmol/L vs (8.57 ± 1.59) μmol/L, t=12.392, P=0.001]. The depression index was positively correlated with the level of homocysteine (r=0.231, P<0.05).
CONCLUSION
The level of serum homocysteine is associated with postpartum depression, suggesting that the level of serum homocysteine might be a risk biomarker for postpartum depression.
Asian Continental Ancestry Group
;
Case-Control Studies
;
Depression, Postpartum
;
blood
;
Female
;
Homocysteine
;
blood
;
Humans
;
Psychiatric Status Rating Scales