The Experts below are selected from a list of 20208 Experts worldwide ranked by ideXlab platform
O N Nagi - One of the best experts on this subject based on the ideXlab platform.
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ReVascularization of diaphyseal bone segments by Vascular Bundle implantation.
Clinical orthopaedics and related research, 2005Co-Authors: O N NagiAbstract:Vascularized bone transfer is an effective, established treatment for aVascular necrosis and atrophic or infected non-unions. However, limited donor sites and technical difficulty limit its application. Vascular Bundle transplantation may provide an alternative. However, even if Vascular ingrowth is presumed to occur in such situations, its extent in aiding reVascularization for ultimate graft incorporation is not well understood. A rabbit tibia model was used to study and compare Vascularized, segmental, diaphyseal, nonVascularized conventional, and Vascular Bundle-implanted grafts with a combination of angiographic, radiographic, histopathologic, and bone scanning techniques. Complete graft incorporation in conventional grafts was observed at 6 months, whereas it was 8 to 12 weeks with either of the Vascularized grafts. The pattern of radionuclide uptake and the duration of graft incorporation between Vascular segmental bone grafts (with intact endosteal blood supply) and Vascular Bundle-implanted segmental grafts were similar. A Vascular Bundle implanted in the recipient bone was found to anastomose extensively with the intraosseous circulation at 6 weeks. Effective reVascularization of bone could be seen when a simple Vascular Bundle was introduced into a segment of bone deprived of its normal blood supply. This simple technique offers promise for improvement of bone graft survival in clinical circumstances.
Mitsuo Ochi - One of the best experts on this subject based on the ideXlab platform.
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feasibility of prefabricated Vascularized bone graft using the combination of fgf 2 and Vascular Bundle implantation within hydroxyapatite for osteointegration
Journal of Biomedical Materials Research Part A, 2008Co-Authors: Tomoyuki Nakasa, Osamu Ishida, Toru Sunagawa, Atsuo Nakamae, Kazunori Yokota, Nobuo Adachi, Mitsuo OchiAbstract:The aim of this study was to demonstrate the feasibility of the prefabricated Vascularized bone graft using an interconnected porous calcium hydroxyapatite ceramic (IP-CHA) in combination with Vascular Bundle implantation and basic fibroblast growth factor (FGF-2) administration in rabbit model. Thirty Japanese white rabbits were used. To make a prefabricated bone graft, the saphenous artery and vein were passed through the hole of the IP-CHA. Hundred micrograms of FGF-2 was administered into the IP-CHA before implanting the Vascular Bundle. First and foremost, the IP-CHA was placed subcutaneously in the medial thigh of rabbits for 4 weeks. In the experimental group, a prefabricated Vascularized bone graft was used while IP-CHA alone was used in the control group. Second, the prefabricated Vascularized bone graft was transplanted from the subcutaneous implanted site into the medial femoral condyle defect of the same rabbit and IP-CHA alone was implanted as the control graft in a different animal. At 4 weeks posttransplantation, bone union with host bone could be observed in the experimental group. However, the area of bone formation of the control group was significantly higher than in the experimental at 2 and 4 weeks posttransplantation. We conclude that the prefabricated Vascularized bone graft when transplanted into a bone defect showed the ability for bone union with the host bone, although further studies are needed to accelerate the process of bone formation.
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prefabrication of Vascularized bone graft using a combination of fibroblast growth factor 2 and Vascular Bundle implantation into a novel interconnected porous calcium hydroxyapatite ceramic
Journal of Biomedical Materials Research Part A, 2005Co-Authors: Tomoyuki Nakasa, Osamu Ishida, Toru Sunagawa, Atsuo Nakamae, Yuji Yasunaga, Muhammad Agung, Mitsuo OchiAbstract:The aim of this study was to create a prefabricated Vascularized bone graft using a novel interconnected porous calcium hydroxyapatite ceramic (IP-CHA) by combining Vascular Bundle implantation and basic fibroblast growth factor (FGF)-2 administration in a rabbit model. Twenty-four Japanese white rabbits were used. The saphenous artery and vein were passed through the hole of the IP-CHA. In an experimental group, 100 μg of FGF-2 was administered into the IP-CHA before implanting the Vascular Bundle. In the control group, the saline was administered into the IP-CHA before implanting the Vascular Bundle. Finally, the IP-CHA was placed subcutaneously in the medial thigh. NeoVascularization from the Vascular Bundle was evaluated at 2 weeks after surgery, and osteogenesis was evaluated at 4 weeks. At 2 weeks, the length and density of newly formed vessels were significantly greater in the experimental group than in the control group. Histological evaluation showed osteoid deposition in the pores of the IP-CHA at 4 weeks in the experimental group, whereas no evidence of osteoid deposition was noted in the control group. This study showed the potential of creating a Vascularized bone graft of a predetermined size and shape using a combination of FGF-2 and Vascular Bundle implantation in the IP-CHA. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Ruiqin Zhong - One of the best experts on this subject based on the ideXlab platform.
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amphivasal Vascular Bundle 1 a gain of function mutation of the ifl1 rev gene is associated with alterations in the polarity of leaves stems and carpels
Plant and Cell Physiology, 2004Co-Authors: Ruiqin Zhong, Zhenghua YeAbstract:In Arabidopsis stems, the Vascular Bundles in the stele are arranged in a ring-like pattern and the Vascular tissues in each Bundle are organized in a collateral pattern. We have shown previously that the semidominant amphivasal Vascular Bundle I (avb1) mutation transforms the collateral Vascular Bundles into amphivasal Bundles and disrupts the ring-like arrangement of Vascular Bundles in the stele. In this study, we show that the avbl mutation occurred in the putative microRNA 165 target sequence in the IFL1/REV gene and caused an amino acid substitution in the putative sterol/lipid-binding START domain. We present direct evidence that the wild-type IFL1/REV mRNA was cleaved within the microRNA 165 target sequence and the avb1 mutation resulted in an inhibition of cleavage and a higher level accumulation of full-length mRNA, suggesting a role of microRNA 165 in the regulation of IFL1/REV gene expression. In addition to an alteration in Vascular patterning, the avbl mutation also caused dramatic changes in fiber cell wall thickening and organ polarity, including aberrant formation and proliferation of cauline leaves and branches, production of trumpet-shaped leaves with reversed adaxial-abaxial identity, ectopic growth of carpel-like structures on the outer surface of carpels, and fasciation of inflorescence. Ectopic overexpression of the avbl mutant cDNA not only phenocopied most of the avbl mutant phenotypes but also led to additional novel phenotypes such as formation of leaves with extremely narrow blades and ectopic production of branches in the axil of siliques. Taken together, these results suggest that the avbl gain-of-function mutation of the IFL1/REV gene alters the positional information that determines Vascular patterning and organ polarity.
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amphivasal Vascular Bundle 1 a gain of function mutation of the ifl1 rev gene is associated with alterations in the polarity of leaves stems and carpels
Plant and Cell Physiology, 2004Co-Authors: Ruiqin ZhongAbstract:In Arabidopsis stems, the Vascular Bundles in the stele are arranged in a ring-like pattern and the Vascular tissues in each Bundle are organized in a collateral pattern. We have shown previously that the semidominant amphivasal Vascular Bundle 1 (avb1) mutation transforms the collateral Vascular Bundles into amphivasal Bundles and disrupts the ring-like arrangement of Vascular Bundles in the stele. In this study, we show that the avb1 mutation occurred in the putative microRNA 165 target sequence in the IFL1/REV gene and caused an amino acid substitution in the putative sterol/lipid-binding START domain. We present direct evidence that the wild-type IFL1/REV mRNA was cleaved within the microRNA 165 target sequence and the avb1 mutation resulted in an inhibition of cleavage and a higher level accumulation of full-length mRNA, suggesting a role of microRNA 165 in the regulation of IFL1/REV gene expression. In addition to an alteration in Vascular patterning, the avb1 mutation also caused dramatic changes in fiber cell wall thickening and organ polarity, including aberrant formation and proliferation of cauline leaves and branches, production of trumpet-shaped leaves with reversed adaxial-abaxial identity, ectopic growth of carpel-like structures on the outer surface of carpels, and fasciation of inflorescence. Ectopic overexpression of the avb1 mutant cDNA not only phenocopied most of the avb1 mutant phenotypes but also led to additional novel phenotypes such as formation of leaves with extremely narrow blades and ectopic production of branches in the axil of siliques. Taken together, these results suggest that the avb1 gain-of-function mutation of the IFL1/REV gene alters the positional information that determines Vascular patterning and organ polarity.
Ming Zhao - One of the best experts on this subject based on the ideXlab platform.
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nitrogen supply regulates Vascular Bundle structure and matter transport characteristics of spring maize under high plant density
Frontiers in Plant Science, 2021Co-Authors: Hong Ren, Ying Jiang, Ming ZhaoAbstract:Nitrogen (N) fertilizer application greatly enhances grain yield by improving dry matter accumulation and grain filling in spring maize. However, how N application rates regulate the Vascular Bundle structure, matter transport and grain filling of spring maize under a high planting density has been poorly understood thus far. In this study, we analysed the relationship between grain filling, Vascular Bundle structure and matter transport efficiency of spring maize in the field. Zhongdan909 (ZD909) was used as the experimental material in a 2-year field experiment from 2015 to 2016, and it was grown under different N levels (0, 150, and 300 kg N ha-1) applied to the grain-filling stage of plots with planting densities of 67,500 plants ha-1 (ND) and 90,000 plants ha-1 (HD). Nitrogen application significantly optimized the structure of the big and small Vascular Bundles. In particular, there was an increase in the total number of small Vascular Bundles in the peduncle and cob of the ear system, i.e., increases of 51.8% and 25.7%, respectively, and the proportions of small Vascular Bundles to the total number of Vascular Bundles in the peduncle and cob were significantly increased. The root bleeding sap and matter transport efficiency (MTE) of maize were significantly increased by N application under both ND and HD, as indicated by the significant increase in the rate of 13C-photosynthate allocation to grain and amount of postsilking dry matter at maturity. Moreover, N application greatly improved the mean grain-filling rate (Gmean) under ND and HD by 30.0% and 36.1%, respectively, and the grain-filling rate increased, leading to a distinct improvement in the grain sink at the grain-filling stage. We concluded that nitrogen application significantly optimized the Vascular Bundle structure of the ear system, increased the matter transport efficiency and improved photosynthate distribution to the grain, ultimately enhancing the filling rate and grain yield.
Peter Langridge - One of the best experts on this subject based on the ideXlab platform.
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the scutellar Vascular Bundle specific promoter of the wheat hd zip iv transcription factor shows similar spatial and temporal activity in transgenic wheat barley and rice
Plant Biotechnology Journal, 2012Co-Authors: Nataliya Kovalchuk, Omid Eini, Natalia Bazanova, M Pallotta, Neil J Shirley, Rohan Singh, Ainur Ismagul, Serik Eliby, Alexander W Johnson, Peter LangridgeAbstract:Summary An HD-Zip IV gene from wheat, TaGL9, was isolated using a Y1H screen of a cDNA library prepared from developing wheat grain. TaGL9 has an amino acid sequence distinct from other reported members of the HD-Zip IV family. The 3¢ untranslated region of TaGL9 was used as a probe to isolate a genomic clone of the TaGL9 homologue from a BAC library prepared from Triticum durum L. cv. Langdon. The full-length gene containing a 3-kb-long promoter region was designated TdGL9H1. Spatial and temporal activity of TdGL9H1 was examined using promoter-GUS fusion constructs in transgenic wheat, barley and rice plants. Whole-mount and histochemical GUS staining patterns revealed grain-specific expression of TdGL9H1. GUS expression was initially observed between 3 and 8 days after pollination (DAP) in embryos at the globular stage and adjacent to the embryo fraction of the endosperm. Expression was strongest in the outer cell layer of the embryo. In developed wheat and barley embryos, strong activity of the promoter was only detected in the main Vascular Bundle of the scutellum, which is known to be responsible for the uptake of nutrients from the endo- sperm during germination and the endosperm-dependent phase of seedling development. Furthermore, this pattern of GUS staining was observed in dry seeds several weeks after harvesting but quickly disappeared during imbibition. The promoter of this gene could be a useful tool for engineering of early seedling vigour and protecting the endosperm to embryo axis pathway from pathogens during grain desiccation and storage.
