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BACKGROUND:Bone defects are caused by many factors,such as inflammation,tumor,trauma or bone diseases.Erythropoietin can promote the differentiation of mesenchymal stem cells into osteoblasts and osteoclasts and act on vascular endothelial cells to induce angiogenesis and accelerate the repair of bone and cartilage defects.Erythropoietin is a growth factor with potential application in bone tissue engineering construction. OBJECTIVE:To expound the application and potential mechanism of erythropoietin in bone tissue engineering. METHODS:The first author searched the related articles published in CNKI,WanFang,VIP,and PubMed databases from 2004 to 2022 by computer.Search terms were"erythropoietin,bone defect,bone regeneration,angiogenesis,osteogenesis,osteoblast,osteoclast,bone tissue engineering"in Chinese and English.Finally,64 articles were included for review. RESULTS AND CONCLUSION:(1)Erythropoietin can directly act on osteoblasts and osteoclasts in the bone marrow microenvironment by promoting the differentiation of mesenchymal stem cells into osteoblasts,osteoclasts,adipocytes,nerve cells and stromal cells.The activation of Wnt/β-catenin,hypoxia-inducible factor 1α/vascular endothelial growth factor,p38 MAPK and EphrinB2/EphB4 signaling pathways mediates the osteogenic differentiation of mesenchymal stem cells.(2)Erythropoietin can not only regulate the production of erythrocytes to alter the oxygen-carrying capacity of blood but also stimulate vascular endothelial cells to promote angiogenesis.The new blood vessels can carry oxygen,nutrients,growth factors,and bone progenitor cells necessary for osteogenesis to the osteogenic site,thereby promoting bone formation and fracture healing.(3)Currently,erythropoietin is being used as a growth factor with osteogenic and angiogenic effects in various types of scaffold materials such as chitosan,polycaprolactone,bioceramics,and nanofibers through various drug delivery methods.Erythropoietin,along with other growth factors such as bone morphogenetic protein-2 and bone morphogenetic protein-9,has been applied to the surface of scaffold materials to participate in the repair of bone defects.Erythropoietin has demonstrated excellent practicality in the construction of new tissue-engineered bone and has potential clinical application value.
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Objective To evaluate the accuracy of different anatomic landmark methods in determining the size of nasopharyngeal airway.Methods Fifty-two patients of both sexes,aged 16-60 yr,of American Society of Anesthesiologists physical status Ⅰ to Ⅲ,with body mass index of 18-30 kg/m2,scheduled for elective awake craniotomy for supratentorial tumors under sedation-awake-sedation anesthesia,were included.For each patient,the distance from the apex of nose to the right tragus (NT),distance from apex of nose to the right mandibular angle (NM),and thyro-mental distance (TM) were measured and marked on a transnasal tube correspondingly.The patients were placed in supine position without pillow,topical anesthesia (nasal mucosal surface) was performed with 2％ lidocaine,and patients were sedated with midazo1am,propofol and dexmedetomidine.When Observer's Assessment of Alertness/Sedation Scale score was 2 or 3 points,the tube was transnasally inserted to each marked depth.When the three marked depths mentioned above were reached,the positions of the tube's tip were checked using a fiberoptic bronchoscope and recorded as:above epiglottis (the tip of the tube was placed between the epiglottis and the free edge of soft palate) or below epiglottis (the tip of the tube placed at or beyond the epiglottis).Results When the depth reached the NT mark,the tube's tip was above epiglottis in 14 cases (27％),and the tube's tip was below epiglottis in 38 cases (73％).When the depth reached the NM mark,the tube's tip was above epiglottis in 31 cases (60％),and the tube's tip was below epiglottis in 21 cases (40％).When the depth reached the TM mark,the tube's tip was above epiglottis in 52 cases (100％).Compared with the NM and NT methods,the TM method had a higher probability with the tube's tip above epiglottis when used to determine the depth of insertion (P＜0.01).Conclusion TM anatomic landmark method provides higher accuracy in determining the size of nasopharyngeal airway.
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Objective To constructan eukaryotic expression recombinant plasmid named pEGFP-N2-PRNP .Methods Total RNA was extracted from alzheimer (AD) disease peripheral blood ,and the PRNP gene was amplified by reverse transcription-poly-merase chain reaction(RT-PCR) .By using gene recombination technique ,human PRNP cDNA was inserted into retroviral vector pEGFP-N2 .The recombinant plasmid was identified by a pair of specified primers containing the restriction sites of Xho Ⅰ and EcoRⅠ .Results The PRNP gene could be obtained by RT-PCR ,the recombinant plasmid was identified by restriction endonucle-ase analysis ,PCR and sequence analysis ,and the expression vector pEGFP-N2-PRNP ,which could be stably expressed in SH-SY5Y cells .Conclusion The recombinant plasmid pEGFP-N2-PRNP is constructed successfully ,Which offers a basic for the further re-search on PRNP biological fuction .
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OBJECTIVE: To observe the effects of Kangfengshi Granules (KFSG) on expressions of the mRNAs of osteoprotegerin (OPG), receptor activator of nuclear factor-kappaB ligand (RANKL) and macrophage colony stimulating factor (M-CSF) in bone tissues of rats with collagen-induced arthritis. METHODS: Forty SD rats were randomly divided into four groups: normal control group, untreated group, cyclosporine A (CsA)-treated group and KFSG-treated group. Except the rats in the normal control group, all the other rats received subcutaneous injection of collagen II to establish collagen-induced arthritis (CIA) models. Then the rats in each group were fed normal saline or corresponding drugs for four weeks. Total RNA was extracted from carpal and digital bones. The expressions of OPG, RANKL and M-CSF mRNAs were examined by real-time PCR. RESULTS: The total incidence of arthritis induced by collagen II in the rats was approximately 90%. The expression levels of RANKL and M-CSF mRNAs and the RANKL mRNA/OPG mRNA ratio in the untreated group, KFSG-treated group and CsA-treated group were all significantly higher than those in the normal control group, while the expression levels of OPG mRNA in those three groups were significantly lower than that in the normal control group. The expression level of OPG mRNA in the KFSG-treated group was obviously higher while the expression level of M-CSF mRNA and the RANKL mRNA/OPG mRNA ratio in the same group were both lower as compared with those in the untreated group. CONCLUSION: The molecular mechanism of effects of KFSG on bone erosion and destruction induced by rheumatoid arthritis is closely correlated with up-regulating the expression of OPG mRNA, down-regulating the expression of M-CSF mRNA and RANKL mRNA/OPG mRNA ratio.
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This study was conducted to find perfect temperature sintered bone as carrier of bone morphogenetic protein (BMP). The different temperature active sintered bones, which were made up of calcine bone and bone morphogenetic protein, were implanted into the defects of rabbit radius. Compared with the sintered bone of 600 degrees C, the sintered bone of 900 degrees C and 1200 degrees C could induce more pieces of bone formation and be replaced by new bone. There were more pieces of new bone formation in sintered bone of 900 degrees C and 1200 degrees C than those in sintered bone of 600 degrees C (P<0.05). There was no difference between the sintered bone of 900 degrees C and 1 200 degrees C (P>0.05). In comparison with the sintered bone of 600 degrees C and 1200 degrees C, the sintered bone of 900 degrees C may be the choicest carrier of bone morphogenetic protein.