• Title/Summary/Keyword: Vascular network

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Extravasating Neutrophil-derived Microparticles Preserve Vascular Barrier Function in Inflamed Tissue

  • Lim, Kihong;Sumagin, Ronen;Hyun, Young-Min
    • IMMUNE NETWORK
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    • v.13 no.3
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    • pp.102-106
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    • 2013
  • Emerging evidence suggests that gap formation and opening of the endothelial junctions during leukocyte extravasation is actively controlled to maintain the integrity of the vascular barrier. While the role for endothelial cells to this process has been well defined, it is not clear whether leukocytes are also actively contributing to endothelial barrier function. We have recently showed that extravasating leukocytes deposit microparticles on the subendothelium during the late stages of extravasation, which is LFA-1 dependent. Using multiphotonintravital microscopy (MP-IVM) of mouse cremaster muscle vessels in the current work, we show that microparticle formation and deposition maintains the integrity of the microvascular barrier during leukocyte extravasation. Inhibition of neutrophil-derived microparticle formation resulted in dramatically increased vascular leakage. These findings suggest that deposition of microparticles during neutrophil extravasation is essential for maintaining endothelial barrier function and may result in temporal difference between neutrophil extravasation and an increase in vascular leakage.

Characteristic Species Distribution of the Baekdoo Great Mountain Chain at Kangwon Province, korea (백두대간계 중 강원도 지역의 종 분포 특성)

  • 정연숙
    • The Korean Journal of Ecology
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    • v.21 no.1
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    • pp.105-112
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    • 1998
  • Characteristics of species distribution in the Baekdoo Great Mountain Chain of Kangwon Province were discussed. Resulting from Detrending Correspondence Analysis based on the floristic composition of 48 mountains, the mountains of the Baekdoo chain tended to aggregate on DCA axis. it represented that there was the peculiar floristic composition of the Baekdoo chain separated from the other mountains. High altitude, longitude near the East Sea and large number of vascular species were main factors for the distribution pattern. And exponential relationships between endemic rare species and number of species were clarified. Even though the regions of the Baekdoo Great Mountain Chain had been conserved relatively well, many regions have been faced to be disturbed for tourism, agriculture, forestry, livestock industry and mining since the local autonomy. Thusm, the necessity for the establishment of large area network through the connection of scattered protected areas in the Baekdoo Great Mountain Chain was suggested. it would play a role as a core of nature conservation to sustain species diversity in Korea.

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Robust Coronary Artery Segmentation in 2D X-ray Images using Local Patch-based Re-connection Methods (지역적 패치기반 보정기법을 활용한 2D X-ray 영상에서의 강인한 관상동맥 재연결 기법)

  • Han, Kyunghoon;Jeon, Byunghwan;Kim, Sekeun;Jang, Yeonggul;Jung, Sunghee;Shim, Hackjoon;Chang, Hyukjae
    • Journal of Broadcast Engineering
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    • v.24 no.4
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    • pp.592-601
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    • 2019
  • For coronary procedures, X-ray angiogram images are useful for diagnosing and assisting procedures. It is challenging to accurately segment a coronary artery using only a single segmentation model in 2D X-ray images due to a complex structure of three-dimensional coronary artery, especially from phenomenon of vessels being broken in the middle or end of coronary artery. In order to solve these problems, the initial segmentation is performed using an existing single model, and the candidate regions for the sophisticate correction is estimated based on the initial segment, and the local patch-based correction is performed in the candidate regions. Through this research, not only the broken coronary arteries are re-connected, but also the distal part of coronary artery that is very thin is additionally correctly found. Further, the performance can be much improved by combining the proposed correction method with any existing coronary artery segmentation method. In this paper, the U-net, a fully convolutional network was chosen as a segmentation method and the proposed correction method was combined with U-net to demonstrate a significant improvement in performance through X-ray images from several patients.

Abdominal-based adipocutaneous advancement flap for reconstructing inguinal defects with contraindications to standard reconstructive approaches: a simple and safe salvage reconstructive option

  • Schaffer, Clara;Haselbach, Daniel;Schiraldi, Luigi;Sorelius, Karl;Kalbermatten, Daniel F.;Raffoul, Wassim;di Summa, Pietro G.
    • Archives of Plastic Surgery
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    • v.48 no.4
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    • pp.395-403
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    • 2021
  • Background Groin wounds occurring after vascular surgical site infection, oncologic resection, or occasionally orthopedic surgery and trauma may represent a surgical challenge. Reconstruction of these defects by the usual workhorse flaps may be contraindicated following previous surgery and in patients with lower limb lymphedema or extreme morbidity. Methods This study included 15 consecutive patients presenting with inguinal wounds after vascular or general surgery that required debridement and soft tissue coverage. All cases had absolute or relative contraindications to conventional reconstructive techniques, including a compromised deep femoral artery network, limb lymphedema, scarring of potential flap harvesting sites, or poor overall condition. Abdominal adipocutaneous excess enabled the performance of adipocutaneous advancement flaps in an abdominoplasty-like fashion. Immediate and long-term outcomes were analyzed. Results Soft tissue coverage was effective in all cases. Two patients required re-intervention due to flap-related complications (venous congestion and partial flap necrosis). All patients fully recovered over a mean±standard deviation follow-up of 2.4±1.5 years. Conclusions Abdominal flaps can be an effective and simple alternative technique for inguinal coverage with reproducible outcomes. In our experience, the main indications are a compromised deep femoral artery network and poor thigh tissue quality. Relative contraindications, such as previous open abdominal surgery, should be considered.

Analysis and 3D Reconstruction of a Cerebral Vascular Network Using Image Threshold Techniques in High-resolution Images of the Mouse Brain (쥐 뇌의 고해상도 이미지에서 임계화 기법을 활용한 뇌혈관 네트워크 분석 및 3D 재현)

  • Lee, Junseok
    • Journal of Korea Multimedia Society
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    • v.22 no.9
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    • pp.992-999
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    • 2019
  • In this paper, I lay the foundation for creating a multiscale atlas that characterizes cerebrovasculature structural changes across the entire brain of a mouse in the Knife-Edge Scanning Microscopy dataset. The geometric reconstruction of the vascular filaments embedded in the volume imaging dataset provides the ability to distinguish cerebral vessels by diameter and other morphological properties across the whole mouse brain. This paper presents a means for studying local variations in the small vascular morphology that have a significant impact on the peripheral nervous system in other cerebral areas, as well as the robust and vulnerable side of the cerebrovasculature system across the large blood vessels. I expect that this foundation will prove invaluable towards data-driven, quantitative investigations into the system-level architectural layout of the cerebrovasculature and surrounding cerebral microstructures.

Free Vascularized Fibular Transfer with Double Barrel Fashion (혈관부착 생비골 중첩 이식술)

  • Chung, Duke-Whan
    • Archives of Reconstructive Microsurgery
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    • v.7 no.1
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    • pp.54-61
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    • 1998
  • Free vascularized fibular is the most usuful bony donor of the long bone reconstruction in reconstructive microsurgical field. It has many benifits such as very strong strut tubular bone, very reliable vascular anatomy with large vascular diameter with long pedicle, minimal donor site morbity too. In that situations of the huge long bone defects in distal femur or proximal tibia, the defective bony shape and strength of the transplanted fibular bone is not enough if only one strut of the fibula is transfered. The bony circulation of the fibula has two ways, one from nutrient artery via peroneal artery through nutrient foramen which makes endosteal arterial network inside of the fibula, another way is periosteal network through outside encircling vascular network of the bone which distributed in muscle sleeves of the fibular diaphysis. Authors modified free vascularized fibular bone graft with transverse osteotomy is made from the anterolateral aspect of the fibular shaft just distal to entry of the nutrient artery. This produces two vascularized bone struts that may be folded pararell to each other but that remain connected by the periosteum and muscle cuff surrounding the peroneal artery and veins. The proximal strut is vascularized by both a periosteal and endosteal blood supply, whereas the distal strut is vascularized by a periosteal blood supply alone. This procedure can call "doule barrel" free vascularized fibular graft. We performed 7 cases of doule barrel fashined fibular transplantation on distal femur and proximal tibial large defects. Average bone union time takes 7 months from that procedure. There were no significant bone union time differences between both proximal and distal struts. After solid union of the transfered double barrel fibular graft, there were no stress fracture in our series. We can propose double barrel free vascualized fibular graft is usuful method in that cases with very large bone defect on large long bones especially metaphyseal defects.

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Kidney transplantation using expanded criteria deceased donors with terminal acute kidney injury: a single center experience in Korea

  • Ko, Kyung Jai;Kim, Young Hwa;Kim, Mi Hyeong;Jun, Kang Woong;Kwon, Kyung Hye;Kim, Hyung Sook;Kim, Sang Dong;Park, Sun Cheol;Kim, Ji Il;Yun, Sang Seob;Moon, In Sung;Hwang, Jeong Kye
    • Annals of Surgical Treatment and Research
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    • v.95 no.5
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    • pp.278-285
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    • 2018
  • Purpose: We investigated the clinical outcomes of deceased donor kidney transplantation (KT) using kidneys with terminal acute kidney injury (AKI). Methods: Between February 2000 and December 2013, we performed 202 deceased donor renal transplants from 159 brain dead donors. According to the expanded criteria donor (ECD) and AKI network criteria, we divided 202 recipients into 4 groups: Group I: Non-AKI & standard criteria donor (SCD) (n = 97); group II: Non-AKI & ECD (n = 15); group III: AKI & SCD (n = 52); and group IV: AKI & ECD (n = 38). Results: The incidence of delayed graft function (DFG) was significantly higher in patients with AKI than it was in the non-AKI group (P = 0.008). There were no significant differences among the 4 groups in graft survival (P = 0.074) or patient survival (P = 0.090). However, the long-term allograft survival rate was significantly lower in group IV than it was in other groups (P = 0.024). Conclusion: Allografts from deceased donors with terminal AKI had a higher incidence of DGF than did those from donors without AKI. However, there is no significant difference in graft and patient survival rates among the groups. So, the utilization of renal grafts from ECDs with terminal AKI is a feasible approach to address the critical organ shortage.

IL-8/CXCL8 Upregulates 12-Lipoxygenase Expression in Vascular Smooth Muscle Cells from Spontaneously Hypertensive Rats

  • Kim, Jung-Hae;Kang, Young-Jin;Kim, Hee-Sun
    • IMMUNE NETWORK
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    • v.9 no.3
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    • pp.106-113
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    • 2009
  • Background: We previously demonstrated remarkable differences in the expression of IL-8/CXCL8 in aortic tissues and vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) compared to VSMC from normotensive Wistar-Kyoto rats (WKY). In the present study, we investigated the direct effect of IL-8/CXCL8 on expression of 12-lipoxygenase (LO), a hypertensive modulator, in SHR VSMC. Methods: Cultured aortic VSMC from SHR and WKY were used. Expression of 12-LO mRNA was determined by real-time polymerase chain reaction. Phosphorlyation of ERK1/2 and production of 12-LO and angiotensin II subtype 1 ($AT_1$) receptor were assessed by Western blots. IL-8/CXCL8-stimulated DNA synthesis was determined by measuring incorporation of [$^3H$]-thymidine. And effect of IL-8/CXCL8 on vascular tone was determined by phenylephrine-induced contraction of thoracic aortic rings. Results: Treatment with IL-8/CXCL8 greatly increased 12-LO mRNA expression and protein production compared to treatment with angiotensin II. IL-8/CXCL8 also increased the expression of the $AT_1$ receptor. The increase in 12-LO induced by IL-8/CXCL8 was inhibited by treatment with an $AT_1$ receptor antagonist. The induction of 12-LO mRNA production and the proliferation of SHR VSMC by IL-8/CXCL8 was mediated by the ERK pathway. The proliferation of SHR VSMC and the vascular contraction in the thoracic aortic ring, both of which were induced by IL-8/CXCL8, were inhibited by baicalein, a 12-LO inhibitor. Conclusion: These results suggest that the potential role of IL-8/CXCL8 in hypertensive processes is likely mediated through the 12-LO pathway.

Application of self-healing technique to fibre reinforced polymer wind turbine blade

  • Fifo, Omosola;Ryan, Kevin;Basu, Biswajit
    • Smart Structures and Systems
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    • v.16 no.4
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    • pp.593-606
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    • 2015
  • This paper presents a novel concept of healing some of the damages in wind turbine blades (WTBs) such as cracks and delamination. This is achieved through an inherent functioning autonomous repairing system. Such wind turbine blades have the benefit of reduced maintenance cost and increased operational period. Previous techniques of developing autonomous healing systems uses hollow glass fibres (HGFs) to deliver repairing fluids to damaged sites. HGFs have been reported with some limitations like, failure to fracture, which undermines their further usage. The self-healing technique described in this paper represents an advancement in the engineering of the delivery mechanism of a self-healing system. It is analogous to the HGF system but without the HGFs, which are replaced by multiple hollow channels created within the composite, inherently in the FRP matrix at fabrication. An in-house fabricated NACA 4412 WTB incorporating this array of network hollow channels was damaged in flexure and then autonomously repaired using the vascular channels. The blade was re-tested under flexure to ascertain the efficiency of the recovered mechanical properties.

A standardized bamboo leaf extract inhibits monocyte adhesion to endothelial cells by modulating vascular cell adhesion protein-1

  • Choi, Sunga;Park, Myoung Soo;Lee, Yu Ran;Lee, Young Chul;Kim, Tae Woo;Do, Seon-Gil;Kim, Dong Seon;Jeon, Byeong Hwa
    • Nutrition Research and Practice
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    • v.7 no.1
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    • pp.9-14
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    • 2013
  • Bamboo leaves (Phyllostachys pubescens Mazel ex J. Houz (Poacea)) have a long history of food and medical applications in Asia, including Japan and Korea. They have been used as a traditional medicine for centuries. We investigated the mechanism of anti-inflammatory activity of a bamboo leaf extract (BLE) on tumor necrosis factor-alpha (TNF-${\alpha}$)-induced monocyte adhesion in human umbilical vein endothelial cells (HUVECs). Exposure of HUVECs to BLE did not inhibit cell viability or cause morphological changes at concentrations ranging from 1 ${\mu}g/ml$ to 1 mg/ml. Treatment with 0.1 mg/ml BLE caused 63% inhibition of monocyte adhesion in TNF-${\alpha}$-activated HUVECs, which was associated with 38.4% suppression of vascular cell adhesion molecule-1 expression. Furthermore, TNF-${\alpha}$-induced reactive oxygen species generation was decreased to 47.9% in BLE treated TNF-${\alpha}$-activated HUVECs. BLE (0.05 mg/ml) also caused about 50% inhibition of interleukin-6 secretion from lipopolysaccharide-stimulated monocyte. The results indicate that BLE may be clinically useful as an anti-inflammatory or anti-oxidant for human cardiovascular disease including atherosclerosis.