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Pulsed dye laser [PDL] is an important treatment for superficial infantile hemangioma, but few studies report on its cellular mechanism. The aim of this study was to evaluate alterations of serum vascular endothelial growth factor [VEGF] level in infantile hemangioma [IH] patients after laser treatment and effects of PDL irradiation on human umbilical vein endothelial cells [HUVECs] in vitro, as well as to explore the biomolecular mechanisms and ultrastructure changes of the PDL effect. 74 children with infant hemangioma including 45 patients in proliferating phase, 18 patients in involuting phase, 11 patients in involuted phase and 10 healthy children were engaged in this study. The plasma VEGF levels of children were measured with the enzyme-linked immunosorbent assay [ELISA]. 24 hours after, HUVECs cultured in vitro were irradiated with PDL, cell apoptosis, mRNA levels of VEGF, and changes of ultrastructure were evaluated using flow cytometry, real-time reverse transcriptase polymerase chain reaction [RT-PCR], and transmission electron microscopy, respectively. The serum VEGF concentrations in children with proliferating hemangiomas were significantly higher than in patients with involuting / involved hemangiomas and healthy patients. After receiving 3 laser treatments, the plasma VEGF levels of IH patients in proliferating hemangiomas decreased significantly. PDL irradiation could down-regulate VEGF mRNA expression of HUVECs, and increase cell apoptosis rate. The present study demonstrates that PDL irradiation imparts apoptosis induction effects on HUVECs in vitro. Furthermore, our results suggest that vascular endothelial growth factor may be of particular importance in pathophysiology and PDL treatment of hemangiomas, also serum VEGF levels may be used as an aid in the follow up of IH. This provides valuable evidence of the PDL effect on infantile hemangioma
ABSTRACT
[Objective]To develop new beta titanium alloys made of titanium, niobium and zirconium (Ti-Nb-Zr) which have higher strength, lower moduli of elasticity. Its biocompatibility in vivo is evaluated in this paper. [Method](1) 24 SD rats were used in the modified air pouch model experiments. Air was injected subcutaneously on the back of rats to form the pouches and the Ti-Nb-Zr particles were introduced into them. The liquid in the pouches was harvested 48 hours later for IL-6 and TNF-?ELISA procedure and the capsules for histology examination. All the results were compared with Ti-6Al-4V. (2) Ti-Nb-Zr bone plates were fixed onto tibias of rabbits. The capsules around the plates and the bone under them were observed at 4, 8, 12, 24 and 36 weeks respectively. Ti-Nb-Zr-bone interfaces were emphasized in this procedure. This time the control material was stainless steel. [Result](1)Ti-Nb-Zr and Ti-6Al-4V particles made the air pouches secret more TNF-? than that of the control (P
ABSTRACT
[Objective]To evaluate the biocompatibility of a new bate titanium alloys made of titanium, niobium and zirconium (Ti-Nb-Zr) which have higher strength and lower elastic modulus by in vitro study.[Method](1)the cell toxicity of Ti-Nb-Zr was evaluated using L-929 cell line's relative growth rate (RGR) which was transformed into 6 toxicity ranks in according with the national standard;(2)the J774A.1macrophages cultured with Ti-Nb-Zr particles whose diameter was about 1 ?m for 24-48 hours were observed using inverted phase contrast microscopy and transmission electron microscopy. Expression of IL-6 and TNF-? mRNA in these cells were measured using RT-PCR technique. The TNF-? in the supernatant was also measured using ELISA method. All the results were compared with the traditional orthopedic implants metal materials such as Ti-6Al-4V and Co-Gr-Mo.[Result]The cell toxicity of Ti-Nb-Zr was ranked zero degree. The particles could be seen in the macrophages under the light microscopy. Ti-Nb-Zr particles made the J774.A1 macrophages less configurative changes than Ti-6Al-4V and Co-Gr-Mo did.Expressions of IL-6 and TNF-? mRNA in J774.A1 cell were increased after stimulation for 48 hours by all kinds of metallic materials. The TNF-? in the supernatants of Ti-Nb-Zr group were less than that of the Ti-6Al-4V and Co-Gr-Mo groups (P
ABSTRACT
[Objective] To develop new bate titanium alloys made of titanium,niobium and zirconium(Ti-Nb-Zr)which have higher strength,lower moduli of elasticity and better biocompatibility for orthopedic implants.[Methods]Alloy elements including titanium,niobium and zirconium were melted together and forged into forging Ti-Nb-Zr.Four kinds of alloys were developed because of the different proportion of alloy elements.All alloys were studied using X-ray diffraction analysis,biomechanical measurements,and scanning and transmission electron microscopy.[Results]X-ray diffraction analyses showed that all the candidates were beta alloys.The as-cast alloys had the strength values in 584~718 Mpa,elastic modulus values in 59~68 Gpa.The peak-aged alloys had the strength values in 706~874 Mpa,elastic modulus values in 59~66 Gpa,elongation rates in 5.4%~20%.The forging procedure could increase the strength significantly but almost have no influence in elastic modulus of Ti-Nb-Zr.[Conclusion]The Ti-Nb-Zr beta titanium alloys developed in our lab have lower modulus and high strength both.It is a promising material for orthopedic implants.
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[Objective]To design a method of in vitro preparation and seperation for metallic wear particles around joint prosthesis and evaluate its feasibility in medical experiments.[Method]Ti-6Al-4V and Co-Gr-Mo alloys were used to make two friction jars respectirely. National inventive patent applied number 03142073.7.Lots of quadrate blocks made of the same materials are put into the jars respectively,which were then.lubri cated by man-made body fluid and vibrated on a bottle shaker.After 21 days the fluid was harvested and centrifuged to get the produced wear particles.The collected particles were studied by using element trace analysis,laser countersizer and scanning electron microscopy.The J774.A1 macrophages cultured together with these particles for 24 hours were observed under inverted phase contrast microscopy and transmission electron microscopy.[Result]A got great amounts of metallic particles with 1?m diameter coned beproduce using this method.The aver age diameter of titanium alloys(Dv90) is 1.011 and that of Co-Gr-Mo is 1.010.Particle size distribution had good consistency in different materials.Under scanning electron microscopy ,the particles had irregular shapes just like those got from revision operations.The particles taken into the J774.A1 macrophages could be seen under inverted p hase contrast microscopy and transmission electron microscopy.[Conclusion]This method is good enough to producl lots of metallic wear particles mosth like those around total joint prosthesis and can be used in further in vivo and in vitro studies about joint prosthesis loosening.