3.Influence of thickness of cancellous bone and cortical bone in stress distribution in vicinity of an implant
Qingsheng CHEN ; Xiaofeng CHEN ; Yejie SHAN ; Xi DING ; Huiming WANG
Journal of Jilin University(Medicine Edition) 2016;42(2):204-209
Objective:To investigate the stress distribution surrounding an implant under different thickness of cancellous bone and cortical bone,and to analyze the influence of thickness ratio and total thickness of bone tissues on the reliability of an implant.Methods:By using the commercial finite element method software Abaqus, a simplified three-dimensional model of a jawbone consisting of a cancellous bone,a cortical bone,an implant,and a ceramic crown was constructed,and then the computation was performed.Under the condition that the system was loaded by lateral and normal stresses, the influence of thickness ratio and total thickness of cancellous bone and cortical bone in the stress distribution surrounding the implant was studied,where the thickness ratios were 3∶1, 2∶1, 1∶1, 1∶2, and 1∶3;the total thickness were 0.5, 1.0, 2.0, 3.0 and 4.0 mm, respectively. Results:The maximum stresses on the cortical bone,the cancellous bone as well as the implant were all found to decrease with the increasing of the total thickness of cortical and cancellous bones,with a higher decreasing rate in the range between 0.5-2.0 mm and a lower decreasing rate between 2.0-4.0 mm. More importantly, the maximum value of stress in the cortical bone within the neck region of the implant was observed to increase dramatically via reducing the total thickness below 2 mm, while it was increased insignificantly when the total thickness was above 2.0 mm. Conclusion:The thickness ratio and the total thickness of cancellous bone and cortical bone have strong influence in the stress distribution surrounding the implant.In dental implantation surgery, the total thickness of cancellous bone and cortical bone should be at least 2 mm, and therefore 2 mm is an optimal value.
4.Study of Color Doppler Flow Imaging and VEGF in Thyroid Tumours
Shumei SHAN ; Yucheng WANG ; Kemin XI ; Caijuan LI
Chinese Medical Equipment Journal 2003;0(11):-
Objective To investigate the expression of vascular endothelial growth factor(VEGF) and Color Doppler flow imaging in human thyroid tumours. Methods 90 cases of thyroid tumours were examined for VEGF expression by means of immunohistochemistry and were examined with color Doppler ultrasound for blood flow. Results The positive rates of VEGF expression were much higher in thyroid carcinomas than that in thyroid adenomas. The difference was significant( P
7.Embryonic mouse pancreas transplantation for treatment of diabetes mellitus
Aijing SHAN ; Jun YANG ; Xi CHEN ; Guang NING ; Zhengming WANG
Chinese Journal of Tissue Engineering Research 2011;15(44):8237-8242
BACKGROUND: Embryonic pancreatic tissue is characterized by its abundance, potent in proliferation & differentiation, and minimal immunological rejection. It is widely considered as potential pancreatic endocrinological stem cells resource for treating diabetes mellitus.OBJECTIVE: To investigate the embryonic mouse pancreatic tissue isolation technique and observe the recipients' blood glucose regulatory effects of the grafted embryonic pancreas in an experimental diabetes mellitus mouse model.METHODS: Pancreatic tissue from C57B1/6 mouse embryos at embryonic days 11.5-16.5 was isolated under the stereomicroscope. C57BL/6 mouse models of streptozocin-induced diabetes mellitus were established and then randomly divided into two groups: transplantation group, in which, five pieces of pancreatic tissue of mice at embryonic 16.5 days were transplanted into mouse renal capsule, and sham-operated control group, in which, 0.05 mL RPMI1640 culture medium was injected into mouse renal capsule. When blood glucose level of the transplantation group mouse was≤ 11.2 mmol/L, the endocrine function of embryonic pancreatic tissue transplanted was detected by IPGTT and IPITT methods and then the transplanted graft was removed for observing the blood glucose relapse.RESULTS AND CONCLUSION: Nearly intact pancreatic tissue of mice at embryonic days 11.5-16.5 could be isolated through the use of stereomicroscope. Pancreatic tissue morphology and color of mice ≤ embryonic 12.5 days were difficultly distinguished from adjacent tissue and they could only be isolated carefully according to the relationship with adjacent organs. Pancreatic tissue of mice > embryonic 12.5 days exhibited initial endocrinological tissue morphology mimic white cauliflower. Histological and ELISA examinations showed that embryonic pancreatic tissue could express and secrete insulin and the insulin level was gradually increased with developmental time. Embryonic pancreatic tissue could grow beneath the recipient renal capsule. The insulin and glucagon expression in the post-transplantational pancreatic tissue graft was increased compared with prior to transplantation. These results suggest that pancreatic tissue is a potential stem cell resource for treating the diabetes mellitus.
8.The therapeutic effects of radiofrequency thermocoagulation denervation mediated by digital subtraction angiography in lumbar facet joint syndrome
Dan-Feng LI ; Long WANG ; Jing-Shan CAO ; Xi WAN ;
Chinese Journal of Physical Medicine and Rehabilitation 2003;0(10):-
Objective To observe the therapeutic effects and assess the feasibility of radiofrequency thermo- coagulation denervation(TRD)mediated by digital subtraction angiography(DSA)for patients with lumbar facet joint syndrome(LFJS).Methods Eighty LFJS patients were randomly divided into two groups:a denervated group(groupⅠ)and a control group (groupⅡ).The lumbar facet joints of the patients in groupⅠwere treated with TRD,while those in groupⅡhad their lumbar facet joint cavities injected with the mixture of 1 mg betamethasone and 1 ml lidocaine.All patients were assessed using the Visual Analog Scale(VAS)before treatment and 30 rain,1 d, 1 w,1 m and 6 m after.Schober values were measured at 1 w,1 m and 6 m after treatment.The therapeutic effects and side effects were assessed at 6 m after treatment.Results VAS scores in groupsⅠandⅡat 30 min,1 d,1 w and 1 m after treatment were remarkably lower than before treatment.In addition,those in groupⅠ6m after treatment were also significantly lower(P<0.01).Compared with those in the groupⅡ,VAS scores in groupⅠwere signifi- cantly decreased at 1 m and 6 m after treatment(P<0.05 and P<0.01,respectively).The schober values in groupⅠat 1 m and 6m were obviously increased in comparison with those in groupⅡ,while the therapeutic effects in groupⅠat 6m after treatment were better than those in groupⅡ(P<0.01).There were no side effects,such as injuries to the nerve roots or dysfunctional dermal sensation,in either group.Conclusion TRD,mediated by DSA,has ther- apeutic effects on LFJS.Such treatment is safe,convenient,and gives long-term pain relief.
9.Research progress of chemokines and their receptors in breast cancer
Wan-yu WANG ; Xiao-xi LÜ ; Zhuo-wei HU ; Shan-shan LIU
Acta Pharmaceutica Sinica 2021;56(6):1521-1531
Chemokines are small cytokines with chemotactic activity, they are involved in regulating immune responses and inflammatory responses. In the development of tumors, chemokines are multi-functional mediators that not only affect the infiltration of immune cells into the tumor, but also have an important impact on tumor growth, angiogenesis, invasion, and metastasis. Besides, they are important targets of tumor therapy. Here we review chemokines involved in the regulation of signaling pathways, analyze the mechanism of chemokines in the development of breast cancer, summarize the chemokines targeted drugs for breast cancer in recent years and make a prospect about the role of chemokines in anti-breast cancer therapy.
10.The efficiency and function detection of NK cell differentiation from human umbilical cord hematopoietic stem cells in vitro
Qi LUO ; Jie YIN ; Yang LI ; Shan HUANG ; Xi WANG ; Jinghua HE
Tianjin Medical Journal 2015;(3):225-228
Objective To detect the efficiency and function of NK cell differentiation from human umbilical cord he?matopoietic stem cells (HSCs) in vitro. Methods CD34+hematopoietic stem cells were isolated from human umbilical cord blood, and inoculated into SCGM medium containing 20 μg/L FMS like tyrosine kinase 3 ligand (Flt-3L), stem cell fac?tor (SCF), interleukin (IL)-7, IL-15 and IL-21. And CD34+HSCs were differentiated into NK cells in directional inducing. The growth state of cells was observed. The expressions of CD56, NKG2D, NKp46, CD3, CD19 and CD34 were detected by flow cytometry in the differentiation of 7, 14, 21 and 28 d. In the differentiation of 21 d and 28 d, the differentiation cells were used as effector cells, and K562 cells as target cells. The ratios of effector cells and target cells were 8∶1, 4∶1, 2∶1 and 1∶1. The killing activity of the differentiated cells was detected by lactate dehydrogenase (LDH) cell toxicity assay and 7AAD/CFSE labeling method. Results CD34+HSCs derived from human umbilical cord blood can proliferate in vitro under appropriate condition. There were no significant differences in the expression of CD3 and CD19 between different differentia?tion stages (7, 14, 21 and 28 d, P>0.05). The expressions of CD56, NKG2D and NKp46 were significantly different (P<0.05), and the ultimate expression amount was (72.57±1.60)%, (32.83±1.29)%and (29.53±2.40)%. The expression of CD34 decreased gradually, and the lowest was (12.13 ± 2.01)%. The maximum killing activity detected by LDH cell toxicity assay and 7AAD/CFSE labeling method reached(49.91±2.76)%and (40.87±1.12)%.The killing activity of NK cells was decreased in the order of 8∶1, 4∶1, 2∶1 and 1∶1 groups (P<0.05). There was no significant difference in the killing activity between NK cells of 28 d and 21 d. Conclusion Human umbilical cord hematopoietic stem cells can differentiate into NK cells un? der appropriate conditions in vitro, and the NK cells induced from differentiation are with killing activity.