ABSTRACT
AIM: To compare the accuracy of different intraocular lens(IOL)calculation formulas in cataract patients with axial length longer than 28mm and a history of radial keratotomy(RK).METHODS: Retrospective study. The medical records of 19 cataract patients(29 eyes)after RK and with axial length longer than 28mm who underwent cataract surgery from January 2011 to July 2020 in Beijing Tongren Hospital were analyzed. The absolute error(AE)of the difference among three different formulas was calculated. AE refers to the absolute value between the actual spherical equivalent after cataract surgery and the spherical equivalent predicted by the IOL formula. The AE values of the three formulas and the percentages of eyes with AE≤0.5, 0.75, 1.0, and 2.0D were calculated and compared.RESULTS: The AE values of the three formulas were significantly different(χ2=8.759, P=0.013). The Barrett True-K formula had the smallest median AE, which was only 0.62(0.20, 1.15)D, followed by the Haigis formula 0.76(0.34, 1.26)D, and the Holladay 1(D-K)formula had the largest 1.01(0.49, 1.62)D. The percentages of affected eyes with AE ≤0.5, 0.75, 1.0, and 2.0D for the Barrett True-K formula were 48%, 59%, 69%, and 93%, which were equal to or higher than the other two formulas.CONCLUSION: The Barrett True-K formula is more recommended among the three formulas for cataract patients after RK and with axial length longer than 28 mm.
ABSTRACT
Objective To evaluate the role of simvastatin in preventing and curing osteoporosis vertebrae by examining the effect from simvastatin on osteogenesis of the lumbar vertebrae in aging rats. Methods Sixty 15-month-old male SD rats were divided into six groups: the control group (injected with normal saline for three month), the baseline group (executed upon the gastric irrigation), the simavastatin-treated group (gastric irrigation with simavastatin at the dose of 5, 10, 20 and 40 mg/kg/d, respectively, for three month). L4 vertebrae were checked by Dual-Energy X-ray Absorptionmetry (DXA), Peri-quantiy CT (pQCT) and mineral apposition rates test. L5 vertebrae were checked by mechanical compression test. Results The value of DXA, pQCT and mineral apposition rate of 10 mg simvastatin group were slightly higher than that of the control group, but no significant differences were found between the two groups. The bone material properties of 10 mg and 20 mg simvastatin group were better than those of the control group, with no significant differences. Conclusions Although 10 mg simvastatin group (equivalent to 12~24 mg/d for human) seemed to have better properties than the other simvastatin groups, but there were no significant differences among these simvastatin-treated group. It is indicated that simvastatin doesn't play a positive role in promoting osteogenesis of the lumbar vertebrae in aging rats, so it may have no preventing or curative effect for osteoporosis of the lumbar vertebrae.
ABSTRACT
Objective To investigate the effect of different perfusion flow rates on proliferation and osteoblastic differentiation of human mesenchymal stem cells (hMSCs) in large scale β-TCP (tricalcium phosphate) scaffold at perfusion bioreactor. Methods hMSCs isolated from iliac bone marrow aspiration were loaded into large scale β-TCP scaffold and cultured in perfusion bioreactor at the perfusion flow rate of 3, 6 or 9 mL/min for 15 days. The culture media were collected for D-glucose consumption assay every 3 days. After perfusion culture for 15 days, the cell-scaffold composites were harvested for assessment of cell viability by MTT colorimetric method, SEM observation and osteogenic gene expression by real-time PCR. Results The proliferation of hMSCs assayed by daily glucose consumption showed that at early stage of culture, cells proliferated faster at flow rate of 9 mL/min than at 3 or 6 mL/min (P<0.001); while at late stage of culture, cells proliferated faster at flow rate of 6 mL/min (P<0.05). The cell viability indicated that the cell-scaffold composites at flow rate of 6 mL/min exhibited the most viable cells (P<0.001). SEM indicated that all the macropores of the scaffold at different flow rates were filled with cellular layers. All cellular layers at flow rate of 3 mL/min were incompact, but that at 9 mL/min were compact; at flow rate of 6 mL/min, the cellular layers were either compact or incompact. Real-time PCR revealed that after perfusion culture for 15 days, the mRNA expression of osteobalstic genes including ALP and OP, were enhanced significantly at flow rate of 6 and 9 mL/min as compared to that at 3 mL/min (P<0.01); however, the 9 mL/min group presented the higher OC expression than 3 and 6 mL/min group (P<0.001). Conclusions At early stage of perfusion culture, the proliferation of hMSCs was promoted at flow rate of 9 mL/min, while at late stage, there was more viable cells in scaffolds at flow rate of 6 mL/min. The osteoblastic differentiation of hMSCs was facilitated with the increase of perfusion flow rate, which was attributed to the increased flow shear stress.
ABSTRACT
<p><b>BACKGROUND</b>Osteosarcoma (OS) is the most common primary malignant tumor of bone. Mouse models of human OS can invariably provide greater insight into the complex mechanisms that underlie the development and pathogenesis of this aggressive tumor. Bioluminescence technology favored tracing cancer cells in vivo. In this study, an OS model was described and evaluated using human OS cell line, Saos2, labeled with luciferase (Saos2-luc).</p><p><b>METHODS</b>Saos2 cells were infected by lentivirus loading a firefly luciferase gene. Luciferase expression of Saos2-luc cells was characterized both in vitro and in vivo. Specific biologic and oncologic features of Saos2-luc cells were analyzed. The OS was established as orthotopic xenografts in nude mice. Both orthotopic tumors and spontaneous lung metastasis were analyzed.</p><p><b>RESULTS</b>Tumorigenesis and spontaneous lung metastasis in nude mice could be monitored in vivo through in vivo imaging system. The enhancement in proliferation, migration and invasion abilities and the attenuation in adhesion ability were observed in Saos2-luc cells compared with Saos2 cells. Furthermore, there were the up-regulation of Osteocalcin, CCR10, CXCR1 and ID1 and the down-regulation of ALP, collagen I, CCR1, CCR3, CXCR3, NID and N-cadherin in Saos2-luc cells compare to Saos2 cells. The rate of spontaneous lung metastasis in Saos2-luc cells was higher than that in Saos2 cells, although without significant difference.</p><p><b>CONCLUSIONS</b>Lentivirus transfection may cause alteration of gene expression profiles and further biological functions. This model can be used in the elucidation of molecular mechanisms of tumorigenesis and the screening of new therapeutic agents.</p>
Subject(s)
Animals , Humans , Male , Mice , Carcinogenesis , Pathology , Cell Line, Tumor , Mice, Inbred BALB C , Mice, Nude , Neoplasm Metastasis , Pathology , Osteosarcoma , Pathology , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Transplantation, HeterologousABSTRACT
With the increase of elderly population, more and more implant operations need to be performed in osteoporotic bone, while different forms of microdamage will be produced in peri-implant bone intraoperatively, including high- and low-density diffuse damages, as well as linear cracks. The length and location of the microcracks are the main factors in affecting the biomechanical performance of bone. Suppression of bone remodeling by bisphosphonates may lead to microdamage accumulation, which is often accompanied with the decrease of bone strength and the increase of bone fragility. Microdamage can be repaired by bone remodeling or mineralization to maintain the strength and structural integrity. Both remo- deling and mineralization can affect the bone quality and long-term implant stability. In this paper, we make a brief summary of some important issues and research progresses in this field.
Subject(s)
Humans , Bone RemodelingABSTRACT
Objective To study the repairing mechanism of mechanical microdamage around implants in the cortical bone of rats. Methods Thirty rats were divided into the ovariectomy group (OVX) and the sham group. At three months after the ovariectomy, a hole was drilled in the right tibial diaphysis by a metal pin. The rats were executed at 1, 2 and 4 weeks, respectively, after the hole drilling. The tetracycline and calcein labeling were performed before the execution. Bone segments containing the hole were stained with the basic fuchsin, embedded in the methylmethacrylate and cut into sections with thickness of 50 μm. Histomorphometric measurement was conducted on bone sections using Bioquant image analysis system. Results Bone resporpion cavities related to the microdamage occurred in both the OVX rats and the sham operated rats. The bone porosity and the number of bone resorption cavities were both greater in the OVX rats than that in the sham operated rats (P<0.05). In addition, the number of bone resorption cavities significantly increased with time after the surgery (P<0.05). Conclusions Increased bone porosity and resorption cavities in OVX rats may be related to the crack formation and the estrogen deficiency, which made the bone remodeling in the cortical bone of OVX rats more active. However, remarkably increased resorption cavities would reduce the bone strength and increase the risk of bone fracture.
ABSTRACT
Bisphosphates as a first line preferred drug for curing osteoporosis has been used for a long time in clinic since it can inhibit the bone remodeling to decrease the risk of bone fracture and increase the bone density. But recent studies show that bisphosphates could cause the accumulation of microdamage to decrease bone quality. The long term use of bisphosphates may reduce the bone toughness and weaken the mechanical properties of bone. Some clinical reports have indicated that patients with osteoporosis tend to have non traumatic fractures after their use of bisphosphates. This article will review the effect of bisphosphates on the microdamage and mechanical properties of bone.
ABSTRACT
<p><b>BACKGROUND</b>Synovium-derived stem cells (SDSCs) with higher chondrogenic potential are attracting considerable attention as a cell source for cartilage regeneration. We investigated the effect of bone morphogenetic protein 2 (BMP-2) on transforming growth factor beta3 (TGF-β3)-induced chondrogenesis of SDSCs isolated from human osteoarthritic synovium in a pellet culture system.</p><p><b>METHODS</b>The clonogenicity, stem cell marker expression and multi-differentiation potential of isolated SDSCs were determined by colony forming unit assay, flow cytometry and specific staining including alizarin red S, Oil red O and alcian blue staining, respectively. SDSCs pellet was cultured in chondrogenic medium with or without TGF-β3 or/and BMP-2. At day 21, the diameter and the weight of the pellets were measured. Chondrogenic differentiation of SDSCs was evaluated by Safranin O staining, immunohistochemical staining of collagen type II, sulfated glycosaminoglycan (sGAG) synthesis and mRNA expression of collagen type II, aggrecan, SOX9, link-protein, collagen type X and BMP receptor II.</p><p><b>RESULTS</b>Cells isolated under the optimized culturing density (10(4)/60 cm(2)) showed clonogenicity and multi-differentiation potential. These cells were positive (> 99%) for CD44, CD90, CD105 and negative (< 10%) for CD34 and CD71. SDSCs differentiated to a chondrocytic phenotype in chondrogenic medium containing TGF-β3 with or without BMP-2. Safranin O staining of the extracellular matrix was positive and the expression of collagen type II was detected. Cell pellets treated with TGF-β3 and BMP-2 were larger in diameter and weight, produced more sGAGs, and expressed higher levels of collagen type II and other chondrogenic markers, except COL10A1, than medium with TGF-β3 alone.</p><p><b>CONCLUSIONS</b>SDSCs could be isolated from human osteoarthritic synovium. Supplementation with BMP-2 significantly promoted the in vitro TGF-β3-induced chondrogenic differentiation of SDSCs.</p>
Subject(s)
Aged , Female , Humans , Male , Middle Aged , Bone Morphogenetic Protein 2 , Pharmacology , Cell Differentiation , Cells, Cultured , Chondrogenesis , Immunohistochemistry , Mesenchymal Stem Cells , Cell Biology , Synovial Membrane , Cell Biology , Transforming Growth Factor beta3 , PharmacologyABSTRACT
Objective To evaluate the role of vascular endothelial growth factor-D(VEGF-D)in lymphangiogenesis of breast cancer,and investigate its relationship with some clinicopathological parameters and prognosis. Methods VEGF-D expression was detected in 85 cases with primary breast carcinoma by immunohistochemistry,and VEGF-D mRNA was detected by RT-PCR.Podoplanin monoclonal antibody was used to mark lymphatic endothelial cell and lymphatic vessel density(LVD) was counted.The relationship among the aboved parameters,clinicopathological parameters and prognosis was analysed. Results It was revealed by immunohistochemistry that VEGF-D expression was ranked by 5 levels: negative,n=5(5.88%);"+",n=17(20%);"++",n=34(40%);"+++",n=22(25.88%),and "++++",n=7(8.24%).VEGF-D expression was associated with tumor lymph node metastasis and TNM clinical stage(P
ABSTRACT
Objective To investigate the effect of nerve growth factor (NGF) on the bone induction of recombinant human bone morphogenetic protein-2 (rhBMP-2) through local application of NGF in the osteoinductive process of BMP. Methods Thirty-six ICR mice were divided into the experimental group and control group at random, and rhBMP-2/collagen composite was implanted into the right thigh muscle pouch of each group. NGF or vehicle was daily injected into the implanted sites of BMP, respectively, for 7 days starting from the third day after surgery. At d10, d20 and d30 after implantation, new bone formation was measured radiographically, biochemically and histologically to compare the osteogenetic capacity of the two groups. Results In both groups, new bone formation was found at d10. However, there was significantly more new bone in the experimental group according to histological and radiographic examinations. At d10 and d20, alkaline phosphatase activity of the local tissue in the experimental group was significantly greater than that in the control group, and calcium and phosphonium contents of samples were also greater in the experimental group. Arrangement of collagen fibers became more regular in the experimental group than that in the control group. Conclusion NGF possesses synergistic effect on ectopic bone formation induced by rhBMP-2.
ABSTRACT
<p><b>OBJECTIVE</b>To study the effect of ultra high molecular weight polyethylene (UHMWPE) particles on macrophages and evaluate the expression of NFAT2, a key transcriptional factor for osteoclast differentiation.</p><p><b>METHODS</b>From November 2004 to February 2005, macrophages were co-cultured with UHMWPE particles. When observed at different times, the proliferation activity of macrophages was analyzed by MTT and the expression of calcineurin (CaN) and NFAT2 by immunohistochemical and RT-PCR method respectively.</p><p><b>RESULTS</b>The macrophages phagocytosed UHMWPE particles in an early time, the expression of CaN and NFAT2 was increased, while the proliferation activity was not enhanced.</p><p><b>CONCLUSIONS</b>UHMWPE particles can stimulate macrophages to phagocytose significantly, and enhance the expression of the transcriptional factor NFAT2.</p>
Subject(s)
Animals , Mice , In Vitro Techniques , Joint Prosthesis , Macrophages , Physiology , NFATC Transcription Factors , Genetics , Phagocytosis , Polyethylenes , Pharmacology , RNA, Messenger , GeneticsABSTRACT
<p><b>OBJECTIVE</b>To evaluate the osteogenic potential of bone morphogenetic protein (BMP)-2 gene transfected goat bone marrow-derived mesenchymal stem cells (MSCs).</p><p><b>METHODS</b>Goat bone marrow-derived MSCs were transfected by Adv-human bone morphogenetic protein (hBMP)-2 gene (Group 1), Adv-beta gal transfected MSCs (Group 2) and uninfected MSCs (Group 3). Western blot analysis, alkaline phosphatase staining, Von Kossa staining and transmission electron microscopy were adopted to determine the phenotype of MSCs. Then the cells were injected into thigh muscles of the nude mice. Radiographical and histological evaluations were performed at different intervals.</p><p><b>RESULTS</b>Only Adv-hBMP-2 transfected MSCs produced hBMP-2. These cells were positive for alkaline phosphatase staining at the 12th day and were positive for Von Kossa staining at the 16th day after gene transfer. Electron microscopic observation showed that there were more rough endoplasmic reticulum, mitochondria and lysosomes in Adv-hBMP-2 transfected MSCs compared to MSCs of other two groups. At the 3rd and 6th weeks after cell injection, ectopic bones were observed in muscles of nude mice of Group 1. Only fibrous tissue or a little bone was found in other two groups.</p><p><b>CONCLUSIONS</b>BMP-2 gene transfected MSCs can differentiate into osteoblasts in vitro and induce bone formation in vivo.</p>
Subject(s)
Animals , Humans , Mice , Blotting, Western , Bone Marrow Cells , Cell Biology , Metabolism , Bone Morphogenetic Protein 2 , Bone Morphogenetic Proteins , Genetics , Cell Differentiation , Genetic Therapy , Goats , Mesenchymal Stem Cells , Cell Biology , Metabolism , Mice, Nude , Osteogenesis , Physiology , Staining and Labeling , Tissue Engineering , Transfection , Transforming Growth Factor beta , GeneticsABSTRACT
<p><b>OBJECTIVE</b>To investigate the effectiveness of human insulin-like growth factor I (hIGF-I) gene transferred into the cultured goat bone marrow mesenchymal stem cells with liposome, and find a new method of cell-mediated gene therapy.</p><p><b>METHODS</b>Bone marrow was extracted from adult goats and cultured in vitro by monolayer. Then the recombinant eukaryotic expression plasmid pIRES2-EGFP-hIGF was transfected into cells by FuGene 6. After transfection, the marker gene coding enhanced green fluorescent protein (EGFP) was observed at different time points. The hIGF concentration in the supernatant fluids was measured by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry stain of hIGF was performed to detect the target protein. Besides, reverse transcription polymerase chain reaction and flow cytometry were also adopted in order to find out the changes of cells after transfection.</p><p><b>RESULTS</b>Bone marrow stem cells were all in the long shuttle-like shape and adhered to the disk. The expression of EGFP was first found at 4 h after transfection. The amount and intensity of EGFP increased gradually during the period of detection and got to the peak degree at 72 h, after that decreased slowly. EGFP was also seen in the second generation cells, but the intensity was relatively faint. The IGF-I concentration secreted into the supernatant was in accordance with the EGFP observed with the peak concentration at 34.75 ng/ml. The outcome of RT-PCR and immunohistochemistry was positive. The morphology of many stem cells was changed into triangular or irregular forms under the circumstance of the secreted hIGF-I. Percentage of stem cells in the S stage increased after transfection.</p><p><b>CONCLUSION</b>The hIGF-I gene can be transfected efficiently and safely into BMSCs by FuGene 6, and the hIGF-I protein can be secreted into the supernatant in a relatively high level during a long period, therefore accelerate the proliferation and differentiation of the transfected cells.</p>
Subject(s)
Animals , Humans , Male , Bone Marrow Cells , Cell Biology , Cell Differentiation , Genetic Vectors , Goats , In Vitro Techniques , Insulin-Like Growth Factor I , Genetics , Mesenchymal Stem Cells , Cell Biology , Plasmids , Genetics , TransfectionABSTRACT
Objective To observe the effect of lnng-term in vitro culture on the biological properties of adipose-derived stem cells(ADSCs)as seeding cells of tissue engineering.Methods The surface makers and apoptosis of primary and passaged human ADSCs were identified by flow cytometric analysis.Osteogenic differentiation of ADSCs at different passages were identified by alkaline phosphatase(ALP),Von Kossa staining and RT-PCR respectively.Results The surface marker expression of mesenchymal stem cells on ADSCs was high and did not change with passages of the cells.The early apoptosis rate of the cells was 1% to 2%,and increased insignificantly from passage one to passage nine.The osteogenic potential of ADSCs confirmed by ALP,Von Kossa staining and RT-PCR was maintained to as late as passage eight.Conclusion Since the biological properties of ADSCs are stable,they can be served as optimal seeding cells for tissue engineering and regenerative research.
ABSTRACT
Objective To investigate the ostengenie potential of adipose-derived stem cells(AD- SCs)when exposed to adenovirns containing hBMP-2 cDNA(Adv-hBMP-2)and offer a choice of cell source for gene therapy and tissue engineering.Methods Human adipose tissues were obtained from patients who received orthopaedic surgery or liposuction.ADSCs were obtained by digesting the adipose tissues.Firstly,flowcytometric analysis was performed for the confirmation of mesenchymal stem cell ori- gin and the surface markers including CD34,CD44,CD68,CD71,CD90,and CD105.The ADSCs were transfected by Adv-hBMP-2 and the effects were tested in vitro,lmmunoprecipitation and Western blotting and ELISA were performed for confirming BMP gone transduction and its stable expression.The transform of ADSCs was assessed by extracellular ALP staining,intracellular ALP spectrophotometry,von Kossa staining and RT-PCR.In the in vivo experiment ADSC-Adv-hBMP-2 cells were injected into the hind limb of nude mice and analyzed radiographically and histologically.Results ADSCs were successfully isolated from human adipose tissues.The isolated ADSCs expressed CD44,CD71,CD90 and CD105 and CD34 and CD68 were absent.The result confirmed the mesenchymal stem cell origin of the cells.West- ern blotting and ELISA confirmed successful and persistent hBMP-2 production by ADSC-Adv-hBMP-2 cells.Extracellular ALP staining,intracellular ALP spectrophotometry,yon Kossa staining and RT-PCR revealed that ADSCs treated with Adv-hBMP-2 had a tendency of transfering into osteoblast.X-ray and H&E sections from hind limb of nude mice injected with ADSC-Adv-hBMP-2 cells confirmed bone forma- tion at 2 weeks.Conclusions Liposuction aspirates contain abundant ADSCs that can be transduced with hBMP-2 gene,and the tranduced ADSCs differentiate into the osteoblast.ADSCs may be an ideal source of mesenchyme-lineage stem cells for gone therapy and tissue engineering.
ABSTRACT
Objective To observe the effect of Ti-6AL-4V particles on morphological and func- tional changes of osteoclast in vitro.Methods Mature osteoclasts separated from New Zealand Rabbits were cultured on glass slices and cortical bone slices.The experimental group was stimulated by Ti-6AL- 4V particles at concentration of 0.1 mg/ml.The cells were stained with TRAP at different culture time to observe the morphological variety.The bone resorption pits on bone slices were stained by toluidine blue and the resorption areas analyzed by computer image analysis software.Results Osteoclasts phagocy- tosed the particles,with irregular shapes,deeper TRAP stain and earlier apoptosis.Stimulation by Ti- 6AL-4V particles brought about larger area of bone absorption lacuna.Conclusion Osteoclasts have the ability to phagocytose Ti-6AL-4V particles,which leads to morphological and functional changes and enhances bone resorption.