1.Theory analysis and research on the dispelled stress shielding on artificial hip joint
Chinese Journal of Tissue Engineering Research 2013;(39):6875-6880
BACKGROUND:For reducing the stress shielding, a lot of the schemes have adopted, and there is no great improvement although via the trial and the application for several ten years. It comes from a root which is the combination by thigh bone (abbreviation of the bone) and metal ic handle (abbreviation of the handle) which causes the serious problems of absorption of bone quality, and this kind of stress shielding effect is produced by abnormal stress and abnormal strain, and affected by various factors, so there is no effective and applicable method to solve this problem.
OBJECTIVE:To select the primary porous layer scheme as the subject of the study and entirely change the appearance and inherent quality as the metal ic handle that cannot transmit the stress is the key to eliminate the stress shielding;making the senior porous layer with the effective measure is the basis to eliminate stress shedding and can solve the disaster and partial inferior position aroused by the primary porous layer.
METHODS:The cobalt-chromium-molybdenum al oy smal metal ic spherules with equal diameter were used to manufacture the senior porous layer structure. The structural member employed in the thigh bone could separate the handle from the bone. This structural member welded on the plane of bone neck could fix the handle with calcar osteotomy surface. And these structural members had an ability to eliminate al the stress shieldings on the artificial hip joint surface.
RESULTS AND CONCLUSION:The senior porous layer was made with cobalt-chromium-molybdenum al oy smal metal ic spherules with the same diameter (1.00-1.29 mm), and the surface of the porous layer was plated with high property of medium layer al oy and arranged orderly and inseparable, and then connected with active diffusion welding technology. The diameter of al the holes was 155-200μm and distributed evenly which was benefit for the bone unit to grew. The al oying of metal materials, ceramic of al oy surface and control ing of size and number of wear particles can solve the bone dissolution of the surrounding porous layer of bone, metal dissolution as wel as its pure cobalt and chromium particle toxicity, cancerization and leukemia. A stipulation of theoretical basis was to eliminate the handle rigidity firstly that could made the separation of handle from the bone became the premise for eliminating the stress shielding. The calcar osteotomy surface grew into the pores of the structural member welded on plane of bone neck could fix the handle, and that was the basis for eliminating the stress shielding. The common roles can eliminate the stress shielding in thigh bone, and the stress shielding on acetabulum is easily to eliminate.
2.CD4~+ CD25~+ regulatory T cells in infection immunity
Qingquan LIU ; Changxing HUANG
Journal of Medical Postgraduates 2003;0(08):-
Immune suppression is a very important mechanism in alleviating immunologic injury,and recent study has showed that CD4~(+)CD25~(+) regulatory T cell is an important component of the immune suppression system.This T cell subset has an obvious immune-suppressing effect and produces its effect not by secreting cytokine but contacting cell directly.In this review,we describe the biological characteristics of CD4~(+)CD25~(+) regulatory T cell and its functions in infection immunity.
3.Notch and metal handle broken in artificial hip joint
Changxing LIU ; Wanlin GUO ; Tianwen LI
Chinese Journal of Tissue Engineering Research 2009;13(48):9523-9525
A broken metal handle accompanied by femoral trunk fracture, which would shorten service life of handles. Therefore, it is necessary to judge whether the notch is the main reason for handle broken. Some literatures thought that the pores of sintered porous coated anatomic (PCA) porous layer produce the notch on the handle surface and the notches lead to the handle broken being incorrect. The Apex of the pore is taken for the bottom of the notch, expanding into a crack, and it should also not grow to the base-alloy, accordingly, the above conclusion is wrong. Some reports pointed out the notch, apex of the pore, will expand into the crack, but it is not associated with the broken handle. Under the sintering temperature, the grain boundary apertures be generated on the base metal surface, the aperture is expanded into the crack, which leads to handle broken in the forced area. However, neither theoretical basis, nor a case of corroboration, can prove exist of notch. Actually, the broken handle is caused by the sintering technology. The high temperature of sintering joining results in grain boundary aperture, when encounter the largest forced area and expand into crack, it will break the handle.
4.Influence and effect of joining techniques on porous layer quality of porous coated anatomic
Changxing LIU ; Wanlin GUO ; Tianwen LI
Chinese Journal of Tissue Engineering Research 2009;13(51):10141-10144
INTRODUCTION: General joining techniques are at low level, which produces some potential problems in porous layer of porous coated anatomic (PCA).LIMITATIONS: The problems in general joining techniques are caused by limitations of each technique, which could not be solved using advanced measures.APPLICATION: The activated diffusion brazing technology is an effective way. Its many advanced processes can solve those potential problems.CONCLUSION: The stress-shielding problem caused by PCA porous layer can be solved by using small metal balls in the same diameter in combination with the advanced activated diffusion brazing technology. Moreover, the high performance brazing metals by activated diffusion brazing technology is harmless for humans.
5.Misunderstanding of porous coated anatomic porous layer bonded by sintering technology
Changxing LIU ; Wanlin GUO ; Tianwen LI
Chinese Journal of Tissue Engineering Research 2009;13(47):9337-9340
OBJECTIVE: Sintering of porous coated anatomic porous layer bonding technology remains controversial because of poor understanding to its essence.ESSENCE: Sintering is a technology that the bonding temperature exceeds 5 ℃ or higher than the base-alloy solids temperature of 1 230 ℃, resulting in base-alloy produce a series of serious problems, such as grain boundary racks, handle broken and so on.HAZARDS: In sintering temperature, the low melting point eutectlc phase and the brittle metal compounds flow out of the grain boundary to bond the small metal balls and the handle, which greatly reduces the fatigue strength. The grain boundary cracks formed and expanded ultimately leading to handle broken.DISCUSSION: The cause of a handle broken is neither notch nor metallurgical defects but sintering process, because high sintering temperature results in grain-boundary lacunas.CONCLUSION: Sintering is not suitable for connecting the force components. High sintering temperature produces grain-boundary lacunas which can expand into cracks and ultimately result in handle broken under some condition.
6.Concurrent chemoradiotherapy for patients with inoperable esophageal cancer
Jun LIU ; Changxing LU ; Jiaming WANG
Chinese Journal of Radiation Oncology 1993;0(03):-
Objective Objective To evaluate the response,survival and toxicity of concurrent chemoradiotherapy for patients with inoperable esophageal cancer. Methods Eighty-eight patients with inoperable esophageal cancer were divided randomly into two groups, 43 patients in group R+C received chemoradiotherapy, while 45 patients in group R received radiotherapy only. For both groups, the same radiation technic was carried out by conventional fractionation, to a total dose of 60-65Gy/30-33Fr/6.0-6.5W. For group R+C patients, concurrent chemotherapy(5-Fu 500mg/d1-4,DDP 20mg/d1-4) was given. Results Complete response rate in group R+C was 33%,while in group R, it was 13% (P
7.The comparison of concurrent chemoradiotherapy with sequential chemo-and radiotherapy for the treatment of patients with stage Ⅲ esophageal carcinoma
Jiaming WANG ; Changxing LU ; Jun LIU ; Changlu WANG ; Jindong GUO
China Oncology 2001;0(05):-
0.05).Conclusions:Concurrent chemoradiotherapy can be well tolerated even though the acute side-effects less than grade 2 were higher in concurrent chemoradiotherapy than other group.Immediate response was very encouraging in the concurrent group.There was no advantage in terms of survival rate in the concurrent group compared to the sequential group.
8.Analysis of the CD4+ CD25high regulatory T cells in peripheral blood of chronic hepatitis B virus in fected patients
Qingquan LIU ; Sha HONG ; Zhe XU ; Jin WANG ; Pingzhong WANG ; Changxing HUANG
Chinese Journal of Microbiology and Immunology 2008;28(10):885-890
Objective To analyze of CD4+ CD25high regulatory T cells(Treg)in peripheral blood of chronic HBV patients and its correlation with multiple clinical indicators.Methods Thirty-five hepatitis B virus(HBV)infected patients in this study were divided into four different clinical types:HBsAb+group(n=5),inactive hepatitis group(n=8),chronic hepatitis group(n=12),and immune tolerance group(n=10).The number of CD4+CD25high Treg and related T cells subgroup in CD3/CD4/CD8 was thoroughly examined by flow cytometry in peripheral blood of HBV infected patients and the healthy contrast group(n=12).Serum HBV markers were determined by commercial ELISA kits.Serum HBV DNA was quantified by commercial real-time PCR kit.Statistical differences were studied to investigate the correlations between CD4+CD25high Treg and different clinical types of HBV infection and clinical indicators.Results The absolute counts of CD25high Treg and its frequency in CD4+ T cells were similar between HBV infected patients [(12.35±6.48)/μ,(1.82±0.87)%]and health controls[(8.91±3.11)/μl,(1.35±0.39)%],P>0.05.The frequency of CD25high Treg in CD4+ T cells from the immune tolerance group was significantly higher than that of the HBsAb+ group,chronic hepatitis group,and the healthy contrast group(P<0.05).The absolute counts of CD25high Treg from the immune tolerance group were significantly higher than the healthy control group(P<0.05),and the frequency of CD25high Treg in CD4+ T cells is negatively correlated to the ALT level(r=-0.418,P=0.038),positively correlated to CD4/CD8 ratio(r=0.344,P=0.021),no correlation to the HBV DNA level(r=0.118,P>0.05).The absolute counts of CD25high Treg were positively correlated to CD4/CD8 ratio(r=0.360,P=0.015),no correlation to ALT level and HBV DNA level(r=-0.211,r=0.060,P>0.05).Conclusion CD4+ CD25high Treg may play a role in immunopathogenesis of chronic HBV infection.
9.Preliminary investigation of stereotactic body radiation therapy for medically inoperable stage Ⅰ / Ⅱ non-small cell lung cancer
Jindong GUO ; Changxing Lü ; Jiaming WANG ; Jun LIU ; Hongxuan LI ; Changlu WANG ; Lanting GAO ; Lei ZHAO
Chinese Journal of Radiation Oncology 2011;20(1):18-22
Objective To evaluate the therapeutic efficacy and treatment-related toxicity of stereotactic body radiation therapy(SBRT)in patients with medically inoperable stage Ⅰ/Ⅱ non-small cell lung cancer(NSCLC). Methods SBRT was applied to 30 patients, including clinically staged T1 ,T2(≤5cm)or T3(chest wall primary tumors only), N0, M0 ,biopsy-confirmed NSCLC. All patients were precluded from lobotomy because of physical condition or comorbidity. No patients developed tumors of any T-stage in the proximal zone. SBRT was performed with the total dose of 50 Gy to 70 Gy in 10 - 11 fractions during 12 - 15 days. prescription line was set onthe edge of the PTV. Results The follow-up rate was 100%. The number of patients who completed the 1-, and 2-year follow-up were 15, and 10, respectively. All 30 patients completed therapy as planned. The complete response(CR), partial response(PR)and stable disease(SD)rates were 37%, 53% and 3%, respectively. With a median follow-up of 16 months(range,4-36 months), Kaplan-Meier local control at 2 years was 94%. The 2-year overall survival was 84% and the 2-year cancer specific survival was 90%. Seven patients(23%)developed Grade 2 pneumonitis, no grade > 2 acute or late lung toxicity was observed. No one developed chest wall pain. Conclusions It is feasible to deliver 50 Gy to 70 Gy of SBRT in 10 - 11 fractions for medically inoperable patients with stage Ⅰ / Ⅱ NSCLC. It was associated with low incidence of toxicities and provided sustained local tumor control.The preliminary investigation indicated the cancer specific survival probability of SBRT was high. It is necessary to perform similar investigation in a larger number of patients with long-term follow-up.
10.Prognostic value of WHO histological subtype and Masaoka clinical stage in postoperative radiotherapy for thymoma
Hongxuan LI ; Changxing Lü ; Jun LIU ; Jiaming WANG ; Jindong GUO ; Changlu WANG ; Lanting GAO
Chinese Journal of Radiation Oncology 2009;18(5):386-389
ween WHO histological subtype and Masaoka clinical stage, and their combination is valuable for guiding postoperative treatment in thymoma.