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.Risk factors for hypoparathyroidism after thyroid papillary carcinoma
Shihang XUE ; Zhiyu LI ; Weizhu WU ; Tongcheng ZHANG ; Zhenyi LU
Chinese Journal of Endocrine Surgery 2019;13(2):119-123
Objective To determine the clinicopathological risk factors and reliable biochemical predictors of the development of hypoparathyroidism after total thyroidectomy plus central compartment node dissection in papillary thyroid carcinoma (PTC).Methods A study was performed on 93 patients who underwent a total thyroidectomy with central compartment node dissection due to PTC.The rate of hypoparathyroidism was calculated.We evaluated the correlations between hypoparathyroidism and clinicopathological factors by chi-square test and logistic regression model for multivariate analysis.The prediction value of PTH and serum calcium level was assessed by a 2×2 contingency table and ROC curve analysis.Results Postoperative hypoparathyroidism was found in 46 patients (49.5%) and 2 with permanent hypoparathyroidism.Univariate analysis showed that tumor size (P=0.034),perithyroidal extension (P=0.003),bilateral cancer(P=0.045)and bilateral central neck dissection (P=0.028)were risk factors for postoperative hypoparathyroidism in patients with PTC.Multivariate analysis showed that perithyroidal extension (P=0.003) and bilateral central neck dissection(P=0.044)were independent risk factors for postoperative hypoparathyroidism in patients with PTC.ROC curve analysis showed that PTH level in the first after operation played significant roles in predicting hypoparathyroidism(AUC 0.875).Conclusions Hypoparathyroidism is the most common complication after total/near-total thyroidectomy.Perithyroidal extension and bilateral central neck dissection are the important risk factors of hypoparathyroidism.The level of PTH is a reliable and early predictive indicator of postoperative hypoparathyroidism.
3.Liposomes and lipid disks traverse the BBB and BBTB as intact forms as revealed by two-step Förster resonance energy transfer imaging.
Tongcheng DAI ; Kuan JIANG ; Weiyue LU
Acta Pharmaceutica Sinica B 2018;8(2):261-271
The blood-brain barrier (BBB) and the blood-brain tumor barrier (BBTB) prevent drug and nano-drug delivery systems from entering the brain. However, ligand-mediated nano-drug delivery systems have significantly enhanced the therapeutic treatment of glioma. In this study we investigated the mechanism especially the integrity of liposomes and lipid disks while traversing the BBB and BBTB both and . Fluorophores (DiO, DiI and DiD) were loaded into liposomes and lipid disks to form Förster resonance energy transfer (FRET) nano-drug delivery systems. Using brain capillary endothelial cells as a BBB model, we show that liposomes and disks are present in the cytoplasm as their intact forms and traverse the BBB with a ratio of 0.68‰ and 1.67‰, respectively. Using human umbilical vein endothelial cells as BBTB model, liposomes and disks remained intact and traversed the BBTB with a ratio of 2.31‰ and 8.32‰ at 3 h. imaging and immunohistochemical results revealed that liposomes and disks could traverse the BBB and BBTB as intact forms. In conclusion, these observations explain in part the mechanism by which nano-drug delivery systems increase the therapeutic treatment of glioma.