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BACKGROUND:The basic idea of artificial disc replacement is the intension to minimize the impact on adjacent segments based on the premise of stabilizing index segment, then prevent and reduce the incidence of adjacent segment degeneration. OBJECTIVE:To explore the indications and contraindications of artificial disc replacement, peri-operative economics considerations, long-term complications, as wel as the effect of artificial lumbar disc replacement combined with fusion surgery. METHODS:The PubMed database, CNKI database and SinoMed database over the past decade were searched for the related articles. The retrospective and prospective clinical trials of artificial lumbar disc replacement were included. Repetitive studies and stale perspectives were excluded. A total of 34 articles were summarized and analyzed in the end. RESULTS AND CONCLUSION:Since the first artificial lumbar disc prosthesis designed to be commercial y distributed in 1982, there have been a plenty of clinical trials on lumbar disc replacement. However, there is no answer to many problems that encountered in clinical trials. The effect of the number of replaced segment on the clinical outcomes, the effect of facet joint degeneration on the clinical outcomes, selection of the patients with the history of lumbar disc surgery, age of the patients and the rest time before disc replacement should be taken into consideration in the researches on indications and contraindications of artificial disc replacement. The intraoperative blood loss, operation time and hospital stay after replacement can be used to evaluate whether lumbar disc replacement is better than the traditional lumbar fusion surgery or not. The complications after lumbar disc replacement include heterotopic ossification, implants mechanical failure, and facet joint and adjacent segment degeneration. The combination of lumbar disc replacement and fusion surgery for the treatment of multi-segmental lumbar disc diseases can achieve complement and thus obtaining the efficacy that better than the application of one surgery alone.
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BACKGROUND:Insulin-like growth factor 1 is the key factor during cartilage development, which is involved in the growth and reconstruction of condylar cartilage. OBJECTIVE:To study the effect of insulin-like growth factor 1 on cel apoptosis and the apopotosis-associated factors of Bcl-2, Bax mRNA and protein expressions of rat condylar chondrocytes. METHODS:The 1-day-old and 28-day-old rat condylar chondrocytes were cultured and identified in vitro. The condylar chondrocytes with different ages were divided into experimental group and control group. After being starved for 24 hours, chondrocytes in the experimental group were incubated with 100μg/L recombined rat insulin-like growth factor 1 for 48 hours, while the chondrocytes in the control group were incubated normal y. RESULTS AND CONCLUSION:Compared with the control group, after being incubated with recombined insulin-like growth factor 1, the number of condylar chondrocytes was increased with high speed proliferation (Pproliferation and reduce cel apoptosis of newborn and adolescent rat condylar chondrocytes, which may be mediated by Bcl-2 and Bax.
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BACKGROUND:Panax notoginseng saponins promotes bone repair by improving vascular proliferation. Therefore, the scaffolds carrying panax notoginseng saponins were supposed to be used to improve bone repair at the bone defect region. However, the biocompatibility of scaffolds remains unclear. OBJECTIVE:To evaluate the biocompatibility of panax notoginseng saponins-hydroxyapatite/chitosan scaffolds. METHODS:A new bone repair scaffold has been generated by thoroughly mixtures of 0, 0.1, 1, 10 mg panax notoginseng saponins and chitosan/hydroxyapatite using in-situ composite technique and freeze-drying technique. Morphology and mechanical property of the scaffold were observed under a scanning electron microscope. (1) Cel proliferation test:rabbit bone marrow mesenchymal stem cel s of passage 3 were cultured in four kinds of drug loaded hydroxyapatite/chitosan composite material leaching liquor. Cel s normal y cultured were considered as controls. 3-(4, 5-Dimethylthiazol-2-yl) 2, 5-diphenyl tetrazolium bromide was used to measure absorbance value of cel s in each group. (2) Hemolysis test:Rabbit anticoagulated blood was added with four kinds of drug loaded hydroxyapatite/chitosan composite material leaching liquor. Absorbance values were measured using a microplate reader in each group. (3) Pyrogen test:The four kinds of drug loaded hydroxyapatite/chitosan composite material leaching liquor and saline were respectively injected into ear vein of rabbits, and the increase of rabbit body temperature was detected. RESULTS AND CONCLUSION:Drug loaded hydroxyapatite/chitosan composite material contained three dimensional porous structure of 110μm in diameter. Drug loading process of panax notoginseng saponins did not significantly affect the porosity, pore size and density of the composite material, but decreased its breaking strength and elastic modulus. The larger amount of drug loading showed a more obvious effect. Simple hydroxyapatite/chitosan composite material had good cel ular compatibility. The composite material after drug loading obviously suppressed cel proliferation, and the larger amount of drug loading showed a more obvious effect. The composite material had good blood compatibility before and after drug loading. The composite material had good pyrogen effects before and after drug loading, but accorded with acceptable quality level of pyrogen test.
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BACKGROUND:Compared with the conventional composite resin, the 3M Z350 nano-resin has good wear resistance, physical mechanical properties, and polishing, and exerts a lower irritation to the dental pulp. Besides fil ing materials, a reliable tooth-prosthesis bonding interface is necessary for resin bonded repairs. OBJECTIVE:To compare the clinical effects of self-etch bonding Adper Easy One and total-etch bonding Single Bond 2 on nano-resin bonding restoration of the anterior teeth. METHODS:120 anterior teeth with vital pulp, which had defects at the incisal ends and were to be restored with nano resins, were divided into two groups randomly. Two kinds of adhesives, self-etch adhesive and total-etch adhesive, combined with nano-resin were used to restore the teeth. The patients were re-examined immediately, 6 months, 1 year and 2 years after the treatment. The fil ings, teeth and pulps of patients were examined, including whether the prosthesis and tooth color were coordinated, whether the gap between the prosthesis and the teeth were sealed, whether the surface of the prosthesis was intact with no loose, whether the prosthesis and teeth had no staining and secondary caries, whether the condition of the tooth pulp had hot or cold stimulation-induced pain. RESULTS AND CONCLUSION:No significant difference in the fil ing effects was found between the two groups when the patients were re-examined immediately, 6 months and 1 year after the treatment (P>0.05). The pulp lesions of the self-etching group were fewer than those of the total-etch group 2 years after the treatment (Pincomplete restoration and secondary caries, respectively. No statistical y significant differences were found in these four aspects between the two groups (P>0.05). The 2-year fol ow up showed a low incidence of pulp lesions and satisfactory clinical performance after 3M Z350 nano-resin working with self-etching bonding system in the nano-resin fil ing of anterior teeth with vital pulp.
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BACKGROUND:The reports on bone morphogenetic protein-7 as a stimulating factor to induce osteogenic are relatively rare. OBJECTIVE:To study the expression of alkaline phosphatase of periosteal cel s after induced by bone morphogenetic protein-7 in vitro. METHODS:Periosteal cel s were obtained from adult tibial periosteum, and then the periosteal cel s were cultured by routine method in vitro. The cel s were divided into experimental group and control group, and then cultured with bone morphogenetic protein-7 plus osteoblast culture adjuvants and simple osteoblast culture adjuvants, respectively. The phase contrast microscope was used to observe the morphology and ultrastructure of periosteal cel s. Each group was observed at 7, 14 and 21 days, and three samples were observed at each time point. Alkaline phosphatase kit was used to detect the expression of osteoblast-specific markers alkaline phosphatase. RESULTS AND CONCLUSION:After cultured for 7 days, the proliferation of periosteal cel s in the experimental group and the control group was increased obviously, and the expression of alkaline phosphatase was detected but less. The cel s were spindle in shape, while the expression of alkaline phosphatase in the experimental group was higher than that in the control group. After cultured for 14 days, the proliferation of periosteal cel s in the experimental group and the control group was increased obviously, the cel morphology was changed from spindle-shaped to wide spindle-shaped, and the expression of alkaline phosphatase in the experimental group was increased significantly when compared with the control group. After cultured for 21 days, the proliferation of periosteal cel s was detected in the experimental group and the control group, and the proliferation in the experimental group was more significant than that in the control group, the cel morphology was wide spindle-shaped, and the number of alkaline phosphatase in the experimental group was higher than that in the control group. Statistical analysis showed that the positive rate of osteogenic markers alkaline phosphatase of bone morphogenetic protein-7 induced periosteal cel s in the experimental group was higher than that in the control group (Posteogenic and regeneration ability, the bone morphogenetic protein-7 could induce periosteal cel s, promote the expression of alkaline phosphatase, and could induce the periosteal cel s to transform into osteoblasts.
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BACKGROUND:Tougu Xiaotong capsule is the clinical prescription for the treatment of osteoarthritis in Fujian University of Traditional Chinese Medicine, and the previous studies mainly focus on effect to cartilage. OBJECTIVE:To observe the effect of Tougu Xiaotong capsule on the proliferation and differentiation of osteoblasts as wel as the expressions of bone remodeling correlated factors. METHODS:Rat osteoblast-like cel line ROS17/2.8 cel s were incubated with Tougu Xiaotong capsule. The ROS17/2.8 cel s were divided into blank control group and Tougu Xiaotong capsule groups with different concentrations. The cel proliferation was determined by methylthiazolyldiphenyl-tetrazolium bromide assay. Osteoblast differentiation biomarkers alkaline phosphatase activity, osteocalcin and bone mineralized nodules were measured with colorimetry, enzyme-linked immunosorbent assay and alizarin red staining, respectively. The real-time PCR and enzyme-linked immunosorbent assay were used to detect the expressions of bone remodeling factors osteoprotegerin/receptor activator of nuclear factorκB ligand. RESULTS AND CONCLUSION:Compared with the control group, the Tougu Xiaotong capsule with the concentration of 0.25-2 g/L could significantly promote the ROS17/2.8 cel proliferation (Ppercentage of bone remodeling factors osteoprotegerin/receptor activator of nuclear factorκB ligand (Pproliferation and differentiation of osteoblasts and bone remodeling.
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BACKGROUND:There are various methods for the treatment of osteonecrosis of femoral head, but there is no satisfactory method to promote the repair of osteonecrosis of femoral head. In recent years, bone marrow mesenchymal stem cel transplantation for the treatment of osteonecrosis of femoral head has achieved certain effect. OBJECTIVE:To review the application progress and problems of bone marrow mesenchymal stem cel transplantation for the treatment of osteonecrosis of femoral head. METHODS:A computer-based online search was performed in PubMed database, Wanfang database and CNKI database for the related articles from 1999 to 2012. The articles on the isolation, culture, differentiation, labeling and in vivo tracing of bone marrow mesenchymal stem cel s were selected, as wel as the basic and clinical researches on bone marrow mesenchymal stem cel transplantation for the treatment of osteonecrosis of femoral head. A total of 39 articles were included for review. RESUTLS AND CONCLUSION:At present, the method for the isolation of bone marrow mesenchymal stem cel s includes adherence screening method, density gradient centrifugation, flow cytometry separation and magnetic activated cel sorting method;the commonly used method for cel labeling and tracing includes isotope tracing method, antigen labeling method, antigen labeling, fluorescent labeling and MRI contrast enhancer labeling method. The method for the treatment of osteonecrosis of femoral head with bone marrow mesenchymal stem cel s includes pith dril ing decompression combined with bone marrow mesenchymal stem cel injection and transplantation, intervention plus bone marrow mesenchymal stem cel transplantation, gene transfection combined with bone marrow mesenchymal stem cel transplantation and tissue engineering technology of bone marrow mesenchymal stem cel s. Although, the research on the bone marrow mesenchymal stem cel transplantation for the treatment of osteonecrosis of femoral head has achieved great progress, there are stil problems needed to be further solved.
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BACKGROUND:The repair and management of ful-thickness skin defects resulting from burns and chronic wounds remain a significant unmet clinical chal enge. Using epidermal stem cel s and keratinocyte growth factor for ful-thickness wound repair is a promising approach. Low-frequency electromagnetic fields which are a non-invasive physical stimulation therapy have been recognized as a good method to enhance wound healing. OBJECTIVE:To develop a new strategy to accelerate wound healing by transplanting transfected epidermal stem cel s and keratinocyte growth factor and treating with low-frequency electromagnetic fields in a mouse model. METHODS:Epidermal stem cel s from Sprague-Dawley neonatal rats were isolated and cultured in vitro, then the cel s were labeled with 5-bromo-2-deoxyuridine and transfected by Ad-KGF, a recombinant adenovirus carrying the keratinocyte growth factor. Mice were given to create ful thickness skin wound on the dorsum and randomly assigned to four groups:control group, transplantation of epidermal stem cel s group, transplantation of keratinocyte growth factor gene modified epidermal stem cel s group, and transplantation of keratinocyte growth factor gene modified epidermal stem cel s plus low-frequency electromagnetic field exposure group. RESULTS AND CONCLUSION:The best healing pattern was observed in the keratinocyte growth factor gene modified epidermal stem cel s plus low-frequency electromagnetic field exposure group (P<0.05) at days 9 and 16. 5-Bromo-2-deoxyuridine labeled cel s existed in the wound in the treated groups at day 9. A significantly increased expression of endogenous keratinocyte growth factor was detected in the transplantation of Keratinocyte Growth Factor gene modified epidermal stem cel s group, and transplantation of keratinocyte growth factor gene modified epidermal stem cel s plus low-frequency electromagnetic field exposure group at day 16. A wel-advanced epithelialization was observed in transplantation of keratinocyte growth factor gene modified epidermal stem cel s plus low-frequency electromagnetic field exposure group at days 16 and 30. These results suggest that low-frequency electromagnetic fields enhanced wound healing fol owing the transplantation of keratinocyte growth factor gene modified epidermal stem cel s.
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BACKGROUND:Cel transplantation offers a new promise of rebuilding the damaged myocardium. But the results of them are not consistent. It is not clear if the transplanted cel s can permanently improve heart function and the mechanism underlying this therapeutic effect. OBJECTIVE:To study the effect of intracoronary autologous bone marrow mononuclear cel transplantation on cardiac function, and angiogenesis and cytokine production in canines with acute myocardial infarction. METHODS:Left anterior descending coronary artery ligation was used to produce acute myocardial infarction models in hybrid canines. Bone marrow mononuclear cel s were harvested by using puncture of anterior crest and posterior superior iliac spine to prepare cel suspension. Sixteen hybrid canines were randomly divided into transplantation group (n=10) and control group (n=6). Bone marrow mononuclear cel s (transplantation group, n=10) or normal saline (control group, n=6) were intracoronarily infused into infarction-related arteries 2 hours after acute myocardial infarction. To evaluate the heart function, we used echocardiography at 2 hours and 6 weeks after acute myocardial infarction. Capil ary density was assessed 6 weeks after transplantation by using von Wil ebrand factor test. The mRNA levels of vascular endothelial growth factor 188, vascular endothelial growth factor 164, basic fibroblast growth factor and matrix metal oproteinase-9 in the infarct area were determined by reverse transcription-PCR at 6 weeks after transplantation. RESULTS AND CONCLUSION:In contrast to the control group, ejection fraction and stroke volume at 6 weeks after transplantation increased significantly in the transplantation group. The transplantation group had a greater amount of new vessels in the peri-infarct area than the control group. Compared with the control group, the mRNA levels of vascular endothelial growth factor 188, vascular endothelial growth factor 164, and basic fibroblast growth factor significantly increased in the transplantation group, but the mRNA level of matrix metal oproteinase-9 significantly decreased in the transplantation group. These findings suggest that intracoronary transplantation of autologous bone marrow mononuclear cel s may improve the cardiac function, and increase capil ary density, especial y in the border zone of infarcted myocardium. Otherwise, bone marrow mononuclear cel transplantation can increase the mRNA levels of vascular endothelial growth factor 188, vascular endothelial growth factor 164, and basic fibroblast growth factor, but decrease the mRNA level of matrix metal oproteinase-9.
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BACKGROUND:Previous studies have found that the susceptibility genes of adiponectin gene and calpain 10 gene of type 2 diabetes are closely related with the incidence of diabetes in Chinese renal transplantation patients. So, are other susceptibility genes of type 2 diabetes also associated with posttransplantation diabetes mel itus? OBJECTIVE:To investigate the association between the zinc transporter solute carrier family 30 member 8 (SLC30A8) gene polymorphism and the posttransplantation diabetes mel itus. METHODS:A total of 97 patients with posttransplantation diabetes mel itus and 301 patents without posttransplantation diabetes mel itus (control group) were selected, and then the SLC30A8 gene rs13266634 genotype was detected with real-time PCR method. The association between gene polymorphism and posttransplantation diabetes mel itus was analyzed with Logistic regression test. RESULTS AND CONCLUSION:There were significant differences in al ele frequencies and genotype distributions of rs13266634 between the patients with and without posttransplantation diabetes mel itus (P<0.05). After adjustments of age, sex, body weight and body mass index, the incidence of posttransplantation diabetes mel itus of the CC genotype patients was 2.108 times to that of the TT genotype patients (odds ratio=2.108, 95%confidence interval:1.075-4.131, P=0.044);and the incidence of posttransplantation diabetes mel itus of the CC+CT genotype patients was 1.862 times to that of the TT genotype patients (odds ratio=1.862, 95%confidence interval:1.049-3.306, P=0.034). The results suggest that the C-al ele in rs13266634 of SLC30A8 gene is the independent risk factor of posttransplantation diabetes mel itus.
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BACKGROUND:Vertebral metastatic tumor often occurs in the thoracolumbar segment, and it is difficult for internal fixation due to the complex anatomical position. OBJECTIVE:To evaluate the stability of lumbar vertebra in the patients with single thoracolumbar vertebral metastases after treated with artificial vertebral placement and internal fixation. METHODS:Sixteen patients (9 male and 7 female) with single thoracolumbar vertebral metastases treated in the Department of Orthopedics, the Fourth Hospital of Hebei Medical University from January 2006 to January 2009 were selected, and the age ranged 40-74 years, averaged 52 years. Before treatment, al the patients were evaluated according to Frankel classification:A grade in two cases, B grade in three cases, C grade in three cases, D grade in five cases, and E grade in three cases. And the vertebral state of patients was detected with X-ray plain film examination, systemic radionuclide bone scanning, CT and MRI. The T11 vertebral metastases were treated with chest approach artificial vertebral placement and internal fixation, and T12-L2 vertebral metastases were treated with artificial vertebral placement and internal fixation via extrapleural and extraperitoneal space approach. RESULTS AND CONCLUSION:Al the 16 patients were fol owed up for 4-32 months, and the average survival time after treatment was 12 months. After treatment, Frankel classification was C grade in three cases, D grade in five cases and E grade in eight cases. The visual analog scale score was decreased from (6.22±1.31) before treatment to (3.25±0.94) after treatment, and there was significant difference between two groups (P<0.05). The artificial vertebral placement and internal fixation can restore the stability of lumbar vertebra in the patients with spinal metastases, and thus improving the symptoms and quality of life.
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BACKGROUND:Silk fibroin, chitosan, and nano hydroxyapatite are natural materials, and they al have good biological activity and physical or chemical properties. As tissue engineering materials, they have been already widely used in clinic or research work, but there are some defects in the application of these three kinds of materials. OBJECTIVE:To discuss the preparation and characteristics of silk fibroin/chitosan/nano hydroxyapatite complicated scaffolds which could be used in bone tissue engineering. METHODS:Silk fibroin, chitosan, and nano hydroxyapatite were separately prepared into 2%solution, and then mixed at the ratio of 1:1:0.5, 1:1:1, 1:1:1.5 respectively. The three-dimensional complicated scaffolds were prepared by those mixed liquids through repeated freeze drying and chemical crosslinking technology. Scanning electron microscope was used to detect the pore size of the scaffolds. Porosity, water absorption rate, and hot-water loss rate were determined. Mechanical tester was used to measure the tensile and compressive modulus of dried three-dimensional scaffolds. RESULTS AND CONCLUSION:The silk fibroin/chitosan/nano hydroxyapatite complicated scaffold in the dry state had no special smel , appeared to be a stabilized solid cylinder, and exhibited clear resiliency and flexibility with a touch. With the increased content of nano hydroxyapatite, the porosity, water absorption rate and average pore size of the scaffolds appeared to be decreased, while the hot-water loss rate and compressive strength were increased. The scaffold prepared at 1:1:1 was better for bone tissue engineering, and the average pore size, water absorption rate and hot-water loss rate were 85.67 μm, (135.65±4.56)%and (22.84±1.06)%, respectively, closer to the needs of the bone tissue engineering. Uniform pores were found within the scaffold at 1:1:1, showing the network structure, developed transport among pores, and the network structure was approximately 10μm.
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BACKGROUND:Periodontal tissue engineering technology provides new ideas and new ways for periodontitis-induced bone defect repair. OBJECTIVE:To develop a culture model for the periodontal ligament cells of miniature swine, which was constructed with hydroxyapatite, to investigate the biocompatibility with hydroxyapatite. METHODS:Periodontal ligament cells from miniature swine were harvested by using tissue explant method. Immunofluorescence was used to detect the expression of stromal cel antigen 1 in the periodontal ligament cells of miniature swine. The third passage cells were co-cultured with a three-dimension hydroxyapatite scaffold, and the biological characteristics of the cells were observed under a scanning electron microscope at days 1, 3, 7 of co-culture. RESULTS AND CONCLUSION:The pirmary miniature swine periodontal ligament cells grew wel , and they were positive for stromal cel antigen 1. Under the scanning electron microscope, the periodontal ligament cells of miniature swine grew wel on the hydroxyapatite scaffold at days 1, 3, 7 of co-culture. These prove that the miniature swine periodontal ligament cells, which can be separated using tissue explant method and cultured successful y in vitro, can grow wel on the hydroxyapatite scaffold.
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BACKGROUND:Preparation of titanium/hydroxyapatite composite by conventional methods has the deficiency of simple structure, low degree of automation and difficulty in porosity and pore size control, which limits the diverse process and manufacture. OBJECTIVE:To evaluate the feasibility of three-dimensional printing technology for the preparation of titanium/hydroxyapatite composite and titanium/hydroxyapatite functional y graded material molding. METHODS:A CAD model of titanium/hydroxyapatite composite was designed to be the cylinder (diameter 25 mm, height 20 mm), while the titanium/hydroxyapatite functional y graded implant designed as a CAD model of the cylinder with 25 mm in diameter asnd 10 mm in height with two layers, the upper layer with titanium powder and the lower layer with titanium/hydroxyapatite powder. The composite and functional y graded implant were processed by the three-dimensional printing and sintered. The sintered titanium/hydroxyapatite composite and titanium/hydroxyapatite functional y graded implant were observed for their microstructures, and the X-ray diffraction analysis and compressive strength testing were performed. RESULTS AND CONCLUSION:The sintered titanium/hydroxyapatite composite and titanium/hydroxyapatite functional y graded implant had uniform contraction and no obvious distortion. The sintered titanium/hydroxyapatite composite had the aperture size from 50 to 150μm. There occurred a chemical reaction between titanium and hydroxyapatite during the sintering process, obtaining the new creations of Ca3(PO4)2, CaTiO3, TiO2 and CaO. Its compressive strength was (184.3±27.1) MPa. The microstructure of titanium/hydroxyapatite functional y graded implant had graded structures with a visible line between the two layers. The results of the microstructure and mechanical properties of titanium/hydroxyapatite composite and titanium/hydroxyapatite functional y graded implant can meet the requirements of medical biological implant materials.
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BACKGROUND: It is difficult to in vitro isolate and culture the ovarian surface epithelium with high purity, strong vitality and stable biological characteristics. Tissue adherence and enzymatic digestion are commonly used for primary culture, but there are certain problems in cel col ection, cel viability and cel purity. OBJECTIVE: To establish a method for primary isolating, culturing and identifying human ovarian epithelium. METHODS: The ovarian surface epithelium was obtained with cel brush innovatively, and then the cells were isolated and purified with erythrocyte spal ation and differential adherence. The epidermal growth factor was added into the serum-free Dulbecco’s modified Eagle’s medium-F12 medium for cel culture. The cel morphology was observed under inverted microscope, and hematoxylin-eosin staining and immunocytochemical staining were used to identify the cells, then the growth curve was draw. RESULTS AND CONCLUSION: The ovarian surface epithelium became adherent after cultured for 24 hours, and reached fusion basical y after cultured for 6-12 days. The cells were polygonal or flat with strong transparency and refraction. The morphological characteristics of the cells were in line with those of the normal epithelial cells, and almost al the isolated cells could express the epithelial cells surface marker CK19. The cells could be passaged for 6-8 generations with wel growth and the cel growth curve was in “S” shape. The purity of the cells was more than 95%. The results suggest that cel brush method is simple to operate and can obtain a large amount of ovarian surface epithelium rapidly. The purity of the isolated cells can reach to 95% after treated with erythrocyte spal ation and differential adherence method and the cells are in stable growth.
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BACKGROUND: Telomerase can maintain the telomere length and avoid cel replicative senescence and apoptosis in somatic cells. Its catalytic subunit cal ed telomerase reverse transcriptase has roles in mediating cellsurvival and anti-apoptotic functions. OBJECTIVE: To evaluate the effects of human telomerase reverse transcriptase on amyloid β1-40-induced human embryonic cortical neurons injury. METHODS: Human cortical neurons derived from 12-16 weeks old aborted fetuses were transfected with recombinant adenovirus vector encoding human telomerase reverse transcriptase. Expression of human telomerase reverse transcriptase was evaluated by immunocytochemical staining. Telomerase activity was measured using a PCR-based telomeric repeat amplification protocol enzyme-linked immunosorbent assay kit. Human embryonic cortical neurons were treated with 10 μmol/L ol/L amyloid β1-40 after transfected for 3 days. Cel viability, reactive oxygen species levels and glutathione contents in human embryonic cortical neurons were respectively detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, fluorescent probe 2',7'-dichlorodihydrofluorescein diacetate and chromatometry. RESULTS AND CONCLUSION: Expression of human telomerase reverse transcriptase reached peak at 3 days after transfection, and the telomerase activity was rebuilt; 10 μmol/L amyloid β1-40 could significantly reduce the cel viability of neurons and glutathione content (P < 0.05 and P < 0.01), and increase the reactive oxygen species levels (P < 0.05). The neurons transfected with human telomerase reverse transcriptase gene could be significantly against the toxicity of amyloid β1-40 and increase the cel viability and glutathione content (P < 0.05 and P < 0.01), and decrease the reactive oxygen species levels (P < 0.05). The results indicate that human telomerase reverse transcriptase can protect amyloid β1-40-induced human embryonic cortical neurons injury
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BACKGROUND:Bone marrow mesenchymal stem cel transplantation is considered as a promising therapy for spinal cord injury. How to more effectively promote the survival of bone marrow mesenchymal stem cel s in the area of spinal cord injury and to accelerate the recovery of motor function after spinal cord injury is a current study focus. Previous studies have found that low-frequency electromagnetic fields can promote bone marrow mesenchymal stem cel proliferation and differentiation, but whether the low-frequency electromagnetic fields can be applied to bone marrow mesenchymal stem cel transplantation for treatment of spinal cord injury requires further studies. OBJECTIVE:To discuss the effects of low-frequency electromagnetic fields on motor function of spinal cord injury rats after transplantation of bone mesenchymal stem cel s. METHODS:Sixty-four rat models of incomplete spinal cord injury at T 10 were established by compression method and then randomized into control group, transplantation group (bone mesenchymal stem cel transplantation), electromagnetic field group and combination group (electromagnetic field+bone mesenchymal stem cel transplantation). After successful modeling, bone mesenchymal stem cel s labeled with 5-bromo-2'-deoxyuridine were injected into the original injured site in the transplantation group and combination group, which were isolated and purified with the fast adherence method;while alpha-minimum essential medium was injected into the electromagnetic field group and control group for instead. At 24 hours post-operation, the electromagnetic field group and combination group were explored to low-frequency electromagnetic fields (frequency 50 Hz, magnetic indaction intensity 5 mT) for 60 minutes per day. RESULTS AND CONCLUSION:After cel transplantation for 21 days, the Basso, Beattie, and Bresnahan scores in the combination group was higher than the other groups (P<0.05). 5-Bromo-2'-deoxyuridine positive cel s grew wel , and integrated into the normal spine;syringomyelia was reduced, and the number of spinal neural cel s was increased in the combination group. In addition, glial fibril ary acidic protein expression was decreased in the combination group, while matrix metal oproteinase 2 expression was increased. It indicates that low-frequency electromagnetic fields could promote recovery of motor function in the spinal cord injury rats transplanted with bone mesenchymal stem cel s, which could be associated that low-frequency electromagnetic fields facilitate the survival of transplanted bone mesenchymal stem cel s, up-regulate the expression of matrix metal oproteinase 2, and reduce glial scar formation in the spinal cord injured site.
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BACKGROUND: During conventional treatment for bone tuberculosis, there is a low effective concentration of anti-tuberculosis drugs, and the therapeutic effect is poor. OBJECTIVE:To develop a new biomaterial as a slow-release artificial carrier that can be directly implanted into the surrounding tissue of bone tuberculosis, maintain a certain anti-tuberculosis drug concentration for a long time, thereby playing an effective therapeutic action. METHODS:Rifampicin/polylactic acid/glycolic acid microspheres and isoniazid/polylactic acid/glycolic acid microspheres were prepared using the emulsion-solvent evaporation method. Usingα-cyanoacrylate, a biological adhesive, two kinds of microspheres were processed into a long-term slow-release bicomponent drug carrier. Then, in vitro release characteristics of the dual-drug sustained-release carrier were observed. After that, the dual-drug sustained-release carrier was implanted into rabbit intertrochanteric femur bone defects for observing drug release concentrations, histocompatibility and bone defect healing at different time points after drug delivery carrier implantation. RESULTS AND CONCLUSION:For rifampicin/polylactic acid/glycolic acid microspheres, the mean particle size was (240±13)μm, and the drug loading load rate was (26±1.5)%. For isoniazid/polylactic acid/glycolic acid microspheres, the mean particle size was (250±10)μm, and drug loading rate was (28±1.8)%. The in vitro cumulative release rate could reach 80%for rifampicin and 90%for isoniazid at day 90. The in vivo released concentration of rifampicin and isoniazid within 90 days was (0.5±0.4) and (0.6±0.3)μg/g, respectively. There were a smal amount of infiltrated neutrophils between the fascia and muscle fibers after the drug delivery carrier was implanted, and the amount of neutrophils in the muscle were reduced significantly at day 59. X-ray plain film showed that bone defects decreased obviously in size. These findings indicate that this dual-drug sustained-release carrier can maintain a certain anti-tuberculosis drug concentration in the surrounding tissues of bone tuberculosis, which is expected to provide a new type of dual-drug delivery carrier in the surgical treatment of bone tuberculosis.
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BACKGROUND: Vascular endothelial growth factor play an important role in promoting healing of osteoporotic fractures, but whether it can affect the bone mineral density is not clear. OBJECTIVE: To observe the correlation between serum vascular endothelial growth factor, bone mineral density and the number of osteoblasts in the ovariectomized rats. METHODS: Forty female Sprague-Dawley rats were randomly divided into ovariectomized group and control group. After 3 months, the bone mineral density of the whole body, femur and lumbar spine was measured. Rat enzyme-linked immunosorbent assay kit was used to measure the level of serum vascular endothelial growth factor. Then, the rats in two groups received femoral metaphyseal fixation, decalcified, dehydrated, embeding in paraffin, slicing and hematoxylin-eosin staining. Each slice was free to take five fields of view (10×40) in order to count the osteoblasts of femur distal metaphysis under optical microscope. RESULTS AND CONCLUSION: After ovariectomized for 3 months, the rats body mass was increased significantly (P 0.05), and the difference of the osteoblast number between ovariectomized group and control group was not significant (P > 0.05). This indicated that there was no correlation between bone mineral density and the number of osteoblasts and vascular endothelial growth factor level in the ovariectomized group and the control group. These findings suggest that the bone mineral density is reduced and the body mass is increased in the ovariectomized rats, and the reduced bone mineral density of ovariectomized rats may be irrelevant with the change of serum vascular endothelial growth factor.
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10.3969/j.issn.2095-4344.2013.23.011