1.Simulation prediction of bone defect repair using biodegradable scaffold based on finite element method.
Gen ZHOU ; Yunfeng LIU ; Xianfeng JIANG
Journal of Biomedical Engineering 2014;31(3):601-605
Aiming at the problem of scaffold degradation in bone tissue engineering, we studied the feasibility that controlls bone defect repair effect with the inhomogeneous structure of scaffold. The prediction model of bone defect repair which contains governing equations for bone formation and scaffold degradation was constructed on the basis of analyzing the process and main influence factors of bone repair in bone tissue engineering. The process of bone defect repair and bone structure after repairing can be predicted by combining the model with finite element method (FEM). Bone defect repair effects with homogenous and inhomogeneous scaffold were simulated respectively by using the above method. The simulation results illustrated that repair effect could be impacted by scaffold structure obviously and it can also be controlled via the inhomogeneous structure of scaffold with some feasibility.
Absorbable Implants
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Bone and Bones
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pathology
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Finite Element Analysis
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Humans
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Osteogenesis
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Tissue Engineering
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Tissue Scaffolds
2.Research progress in seeding cells for bladder reconstruction
Yunfeng LIAO ; Chunxiao LIU ; Xiaofeng ZOU
Chinese Journal of Tissue Engineering Research 2009;13(50):9937-9940
Bladder tissue engineering includes three components, namely cell scaffold, seeding cells and message factor. Seeding cells is essential to construct tissue engineering organs and is the native material of organ reconstruction. It is important to find a seeding cell which can not only provide excellent biocompatibility, but also can generate enough cells in work of organ reconstruction. At present, there are some commonly used seeding cells, for example, urinary bladder transitional epithelial cells,smooth muscle cells, coculture of smooth muscle cells and transitional epithelial cells, mesenchymal stem cells. Among the total,coculture of smooth muscle cells and transitional epithelial cells and mesenchymal stern cells are better than the others. The current problems of seeding cells are as follows: ①The mature cells that have been completely differentiated are limited in source and immunological rejection. ② The mature cells that have been completely differentiated during the differentiated only can generate in the limited passage culture procedure and they will age and die out of the passage maximum; in addition, the dedifferentiation also exists; ③further analysis should focus on the coculture of smooth muscle cells and transitional epithelial cells and mesenchymal stem cells into normal bladder.
3.Clinical characteristics and cardiac hemodynamic changes of patent ductus ateriosus in preterm infants.
Danfang LU ; Yunfeng LIU ; Xiaomei TONG
Chinese Journal of Pediatrics 2015;53(3):187-193
OBJECTIVETo study clinical characteristics and evaluate cardiac hemodynamic changes in premature infants with patent ductus ateriosus (PDA).
METHODOne hundred and five infants born at ≤ 34 weeks' gestational age (GA) and ≤2 000 g birth weight (BW) were prospectively enrolled, including 63 males and 42 females, and the mean GA was (31. 1 ± 1.9) weeks and BW (1 401 ± 314) g. Echocardiography was done to detect hemodynamically significant PDA (hsPDA) and to evaluate left ventricular function at 2, 3, 5 and 7 d respectively after birth. On the basis of clinical symptoms and echocardiographic outcome, all the cases were divided into 3 groups: hsPDA group (n = 34), non-hsPDA (nhsPDA) group (n = 44) and non-PDA (nPDA) group (n = 27) to survey and compare general conditions, DA diameter, shunt direction, left ventricular function and complications.
RESULTThe hsPDA group had smaller GA ((30. 5 ± 2. 1) vs. (31. 6 ± 1. 6) weeks, P = 0. 01) and greater proportion of pulmonary surfactant use and mechanical ventilation (2, 3, 5 d of birth) than the nhsPDA and the nPDA group (χ2 = 11. 62, 14. 95, 12. 73, 1:1. 59, P = 0. 00; 0. 00, 0. 01, 0. 01). Univariate and multivariate Logistic regression analysis indicated that the average length of stay (ALOS) was correlated with hsPDA (F =3. 52 and P =0. 03, OR 1. 03 and P =0. 02). The ALOS was longer in the hsPDA group than in the nhsPDA and the nPDA group ((39 ±23)vs. (30 ± 16)and(29 ±13) d, P =0.02, 0.03). There was no significant.difference in rates of mortality/giving-up of treatment among the three groups (5. 9% (2/34)vs. 0 (0/44) and 3. 7% (1/27), χ2 = 5. 26, P = 0. 06). Diastolic blood pressure and mean blood pressure were significantly lower in the hsPDA group than in the other two groups (P all <0. 05) at 2, 3 and 5 days after birth and the pulse pressure was found significantly higher in the hsPDA group than in the nPDA group at 2 d after birth. Univariate and multivariate Logistic regression analysis demonstrated that hsPDA was correlated significantly with neonatal respiratory distress syndrome (NRDS) and bronchopulmonary dysplasia (BPD) (χ2 =7. 34 and 7. 39, P = 0. 02 and 0. 02; OR = 3. 46 and 4. 01, P = 0. 04 and 0. 02). Premature infants with hsPDA had normal left ventricular fractional shortening (FS) and left ventricular ejection fraction (LVEF), although the cardiac output (CO) of left ventricle increased significantly(F = 6. 93, P <0. 01) within seven days of birth. There was no significant difference in cardiac hemodynamic parameters among closed group of hsPDA group, nhsPDA group and nPDA group simutaneously reexamined at 7th day after birth. The CO was extremely significantly different among premature infants who had different GAs and BWs. The lower the GAs and the BWs, the lower the value of CO(F =5. 16 and 14. 87, P all <0. 01). The DA diameter was reduced much more dramatically after ibuprofen treatment than before in hsPDA group(t = 5. 58, P <0. 01).
CONCLUSIONThe GA, PS use and mechanical ventilation were probably associated with hsPDA. The mean blood pressure and diastolic blood pressure were decreased and pulse pressure was increased in preterm infants with hsPDA that correlated significantly with ALOS, NRDS and BPD. In addition, increased CO values were found in hsPDA group. Oral ibuprofen administered to preterm infants for hsPDA at > 24 h of life promoted ductal closure.
Birth Weight ; Bronchopulmonary Dysplasia ; Cardiac Output ; Cyclooxygenase Inhibitors ; therapeutic use ; Ductus Arteriosus, Patent ; physiopathology ; Echocardiography ; Female ; Gestational Age ; Hemodynamics ; Humans ; Ibuprofen ; therapeutic use ; Infant, Newborn ; Infant, Premature ; Infant, Premature, Diseases ; Male ; Pulmonary Surfactants ; Respiration, Artificial ; Respiratory Distress Syndrome, Newborn ; Ventricular Function, Left
4.Design and clinical application of anatomical locked hook-plate and internal fixation system for femoral intertrochanteric fracture
Yunfeng LI ; Baiwei LIU ; Jian LU
Orthopedic Journal of China 2006;0(14):-
[Objective]To explore a new type of internal fixation system for the fixation of femoral intertrochanteric fracture.[Method]According to femoral tuberosity anatomical shape,anatomical locked hook-plate internal fixation system(ALHP) was designed,its biomechanical properties was examined and ALHP was applied for the clinical treatment of intertrochanteric fracture of the aged patients.[Result]Twenty-seven cases of intertrochanteric fracture were fixed with ALHP and followed up from 1.5 to 2 years,with an average time was 1.8 years.According to Sanders functional sores:the good and excellent rate was 100%.[Conclusion]Anatomy type locked hook-plate internal fixation system possesses reasonable design and produces firm fixation for intertrochanteric fracture.It can offer the elderly patients early exercises and reduce the incidence of complication.
5.HRCT appearance of localized organizing pneumonia
Qingwei LIU ; Yunfeng CUI ; Weihua GUO
Chinese Journal of Radiology 2001;0(08):-
Objective To analyze the CT, especially HRCT appearance of localized organizing pneumonia. Methods The CT scans of nine patients with histologically proved localized organizing pneumonia were studied retrospectively. Results The size of the lesions in nine cases varied from 2 to 4 cm( average 2.5 cm). Eight lesions were located in the peripheral lung parenchyma near the pleural surface. The lesions were detected as round in four, anomaly in five. The margin of six lesions had inward bow indentation. Infiltrating lesions in surrounding structures were found in four cases. Conclusion The CT, especially HRCT appearance of localized organizing pneumonia shows some features that can make most of them to be differentiated from other lesions.
6.A retrospective study on pulmonary embolism:a report of 67 cases
Liang LI ; Yunfeng XIA ; Runmei LIU
Medical Journal of Chinese People's Liberation Army 2001;0(09):-
Objective To retrospectively analyze the clinical features,diagnostic experience and therapy of pulmonary embolism for reduction of misdiagnosis and missed diagnosis,and for improving the cure rate.Methods The data of clinical features,findings by auxiliary examination and therapeutic efficacy of 67 patients with pulmonary embolism admitted to the First Affiliated Hospital of General Hospital of PLA were summarized.The usual clinical manifestations were summarized based on the clinical symptoms of and the frequency of objective signs in the patients with the correct diagnosis.Auxiliary examinations included routine and sophisticated examinations such as CT pulmonary angiography(CTPA) and emission computed tomography(ECT),which were specially emphasized for summing up and optimizing the diagnosis.Comparisons were made of the therapeutic efficacy and complications between the treatment with thrombolysis combined with anticoagulation and simple anticoagulation.Results The primary clinical manifestations of the patients with pulmonary embolism included dyspnea,cough,chest pain,fever and hemoptysis,etc.Findings of D-Dimer assay might serve as a sensitive but not specific indicator in screening the suspected patients.For the sophisticated examinations,CTPA confirmed the diagnosis in 28 out of 31(90.32%) patients,and ECT confirmed the diagnosis in 39 out of 51(76.47%).All the patients who had undergone lung angiography received the final diagnosis,but the majority of them were reluctant to accept this examination because of potential risk of the technique.The total cure rate of thrombolysis combining anticoagulation was 90.62%(29/32),in which the administration of recombinant tissue-type plasminogen activator(rt-PA)-2h was most efficacious(with 100% of cure rate).Simple anticoagulation therapy gave a lower cure rate(68.57%,24/35) but a higher incidence of hemorrhagic complication(31.25%).After the administration of thrombolysis combined with anticoagulation therapy,both PaO2 and CTPA examinations showed significant changes for the better after the treatment compared with that before the treatment(P
7.Low Temperature Plasma Sterilization and Its Application
Zina ZHENG ; Yunfeng LIU ; Junmei YU
Chinese Journal of Nosocomiology 2006;0(08):-
OBJECTIVE To evaluate the sterilization steps and effects of low temperature plasma on heat-resistant items. METHODS Low temperature plasma sterilization was adopted to operate according to standard procedures including pre-sterilizaing, packaging, sterilization, unloading and storageing. RESULTS Low temperature plasma had the features of reliable sterilization effect, easy to monitor, short time needed, and high utilization rate which could greatly increase the number of surgery and have a long term storage. CONCLUSIONS Low temperature plasma sterilization is a kind of fast, safe and effective way of sterilization by which the sterilization quality is guaranteed and the hospital infection rate is reduced greatly to meet the clinical demands to sterile items.
8.Clinical application of vaccum sealing drainage in plasma cell mastitis
Huaming TANG ; Peng ZHANG ; Yunfeng LIU
Chinese Journal of Endocrine Surgery 2017;11(2):131-134
Objective To study the clinical value of vaccum sealing drainage in plasma cell mastitis.Methods 59 patients with plasma cell mastitis admitted in our hospital were treated with vaccum sealing drainage (the experimental group) from Jan.2011 to Apr.2014.59 plasma cell mastitis patients were treated with traditional vaseline gauze drainage (the control group).Clinical data like hospitalization length,healing time,healing grade,scar size,dressing change frequency,one year recurrence rate and breast deformity were retrospectively analyzed.Results Patients treated with vaccum sealing drainage had shorter hospitalization length and healing time,lower one year recurrence rate and less breast deformity compared to patients treated with traditional Vaseline gauze drainage (P<0.01),while there was no significant difference in terms of healing grade (P>0.05).Conclusions Vaccum sealing drainage can significantly shorten the hospitalization time and incision healing time,reduce dressing change frequency and one year recurrence rate in patients with plasma cell mastitis.Because of the smaller scar caused by vaccum sealing drainage,the breast deformity is also less.It is of clinical value for plasma cell mastitis.
9.Effects of IL-22 on rheumatoid arthritis fibroblast-like synoviocytes
Meng LIU ; Yan LIU ; Mengru YANG ; Biyao MO ; Yunfeng PAN
Chinese Journal of Pathophysiology 2016;32(7):1273-1278
AIM:To determine the effects and mechanisms of interleukin-22 (IL-22) on the fibroblast-like sy-noviocytes ( FLSs) from rheumatoid arthritis ( RA) patients.METHODS:RA-FLSs were cultured by tissue culture meth-od.RA-FLSs were incubated with different concentrations of IL-22 (0,1,10,100μg/L) for 24 h, 48 h and 72 h.The cell viability was examined by CCK-8 assay.IL-22 at concentration of 10 μg/L was used to stimulate RA-FLSs for 24 h, and the change of cell cycle distribution was identified by flow cytometry.The effects of IL-22 at concentrations of 0, 1, 10, 100μg/L and/or STA-21 (a STAT3 inhibitor at concentrations of 0, 25, 50μmol/L) on the protein levels of Bcl-2 and p-STAT3 in the RA-FLSs were determined by Western blot.RESULTS:Compared with control group, stimulation of rhIL-22 at different concentrations for 24 h, 48 h and 72 h, the cells viabilityof RA-FLSs were obviously increased ( P<0.05 ) . After co-cultured with 10 μg/L rhIL-22 for 24 h, the percentages of RA-FLSs were obviously increased in the G2/M+S phase and decreased in the G0/G1 phase.At the same time, rhIL-22 increased, but STA-21 decreased the protein levels of Bcl-2 but p-STAT3 in the RA-FLSs obviously (P<0.05).Treatment with STAT3 inhibitor STA-21 reversed the effect of IL-22-induced Bcl-2 upregulation in the RA-FLSs ( P<0.01 ) .CONCLUSION: STAT3 is critical in the process of IL-22-induced Bcl-2 upregulation in RA-FLSs, indicating that IL-22 may play a role in the apoptosis of RA-FLSs.
10.Metabolites and metabolic pathways of mesaconitine in rat liver microsomal investigated by using UPLC-MS/MS method in vitro.
Yunfeng BI ; Shu LIU ; Ruixing ZHANG ; Fengrui SONG ; Zhiqiang LIU
Acta Pharmaceutica Sinica 2013;48(12):1823-8
Mesaconitine was incubated with rat liver microsomes in vitro. The metabolites of mesaconitine in rat liver microsomes were identified by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method with high resolution power. A typical reaction mixture of 100 mol L-1 Tris-HCI buffer (pH 7.4) containing 0.5 gL-1 microsomal protein and 50 micro molL-1 mesaconitine was prepared. The above reaction mixture was divided into six groups, and the volume of each group was 200 micro L. The incubation mixture was pre-incubated at 37 degrees C for 2 min and the reactions were initiated by adding NADPH generating system. After 90 min incubation at 37 degrees C, 200 micro L of acetonitrile was added to each group to stop the reaction. The metabolites of mesaconitine were investigated by UPLC-MS/MS method. Mesaconitine and 6 metabolites M1-M6 were found in the incubation system. The structures were characterized according to the data from MS/MS spectra and literatures. The metabolic reactions of mesaconitine in rat liver microsomes included the demethylation, deacetylation, dehydrogenation and hydroxylation. The major metabolic pathways of mesaconitine in rat liver microsomes were determined by UPLC-MS/MS on multiple reaction monitoring (MRM) mode combined with specific inhibitors of cytochrome P450 (CYP) isoforms, including alpha-naphthoflavone (CYP1A2), quinine (CYP2D), diethyldithiocarbamate (CYP2E1), ketoconazole (CYP3A) and sulfaphenazole (CYP2C), separately. Mesaconitine was mainly metabolized by CYP3A. CYP2C and CYP2D were also more important CYP isoforms for the metabolism reactions of mesaconitine, but CYP1A2 and CYP2E1 haven't any contribution to MA metabolism in rat liver microsomes.