• Archives of Plastic Surgery
• /
• 제36권4호
• /
• pp.380-384
• /
• 2009

Purpose: Autologous vessels remain the gold standard for vascular grafts in microanastomoses. However, they are sometimes unavailable and have a limited long - term patency. Synthetic vessels have high success rates in large - diameter reconstructions but failed when used as small - diameter grafts due to graft occlusion. It has been proved that endothelial cell seeding improves prosthesis performance and long - term patency. Among polyurethane, PET and ePTFE, polyurethane has the best affinity to endothelial cells and mechanical properties closest to human vessels. We examined the ability of endothelial cells to attach to a polyurethane graft manufactured by the electrospinning method. Methods: Endothelial cells, which were cultured from porcine internal jugular veins, were attached to polyurethane grafts with an internal diameter of 3 mm. The same cells were attached to allogeneic decellularized porcine internal carotid artery grafts as controls. Both of the 10 mm - long grafts were exposed to endothelial cells in a well for 1 hour. Each well contained $2{\times}10^5$ endothelial cells. The graft materials were rotated through 90 degrees every 15 minutes in order to minimize the effect of gravity. The extent of cell attachment was examined with the MTT assay. Results: The MTT assay showed good incorporation of endothelial cells into both grafts. For the evaluation of affinity, the number of attached cells was counted at 10 fields of microscopic examination with ${\times}40$ magnification. Endothelial cells adhered more to polyurethane grafts (mean, $127.4{\pm}6.2cells$) compared to porcine artery grafts (mean $45.8{\pm}5.1cells$)(p<0.05,Mann - Whitney test). Conclusion: In this study, we attached porcine endothelial cells to polyurethane grafts, manufactured by electrospinning. The grafts exhibited a better affinity to endothelial cells than allogeneic decellularized porcine internal carotid artery grafts. It is suggested that the time required for endothelial cells to attach to decellulized artery grafts may be longer than that which is required for attachment to polyurethane grafts.

• 한국작물학회지
• /
• 제31권2호
• /
• pp.162-166
• /
• 1986

피맥5품종, 과맥5품종 및 맥주맥5품종 등 15품종을 공시하여 대맥절간의 조직형태와 외부형태의 품종간 차리 및 형질들간의 상호관연성을 구명하기 위하여 실시한 시험으로 그 결과를 요약하면 아래와 같다. 1. 상위절간장(상위로부터 1∼3절간)은 맥주맥>피맥>과맥의 순으로 길었으며, 하위절간장 (상위로부터 4∼5절간)은 과맥>피맥>맥주맥의 순으로 길었다. 2. 절간의 굵기는 과맥>피맥>맥주맥의 순으로 굵었고, 올보리, 세도하다가, 무안보리 및 광성이 굵은 경향이었다. 3. 간벽 두께는 상위절간(과맥>피맥>맥주맥), 하위절간(피맥>맥주맥>과맥)의 순으로 두꺼웠다. 4. 상위 제 1절간의 대유관속수는 피맥품종들이 과맥과 맥주맥품종들 보다 많았다. 5. 대유관동 크기는 피맥과 과맥품종들이 맥주맥품종들 보다 큰 경향 이었다. 6. 대유관동 크기와 간벽 두께 및 절간의 굵기와는 유의한 정상관을 나타냈고, 간벽 두께와 절간장 및 간장과는 부의 상관관계를 나타냈으며, 간벽 두께와 절간 굵기와는 유의한 정의 산관을 보였다.

• Journal of Korean Neurosurgical Society
• /
• 제41권2호
• /
• pp.82-87
• /
• 2007

Objective : Pontine hemorrhages usually result in a much higher morbidity and mortality than any other intracranial vascular lesion. The purpose of this study was to evaluate survival and the contributing factors for patients with pontine hemorrhage. Methods : Of the 41 patients who were admitted to our hospital with their first acute pontine hemorrhage from 1997 to 2005, 35 patients were included in this study. Medical records were reviewed to confirm the accuracy of diagnosis and collect demographic, clinical and radiological data. The patients were divided into two groups, survivors and deceased patients; then the survivors were divided again into a group of patient with good results and those with poor results. The location of the hematoma, maximum anteroposterior [AP] diameter, maximum transverse diameter, hematoma volume, ventricular extension, extension into the midbrain, hydrocephalus and initial Glasgow coma scale [GCS] were evaluated. Results : The two year survival rate was 58.5%. The survival of patients with pontine hemorrhage was affected by initial GCS score and transverse hematoma dimeter. Functional outcome of patients who survived was affected by initial GCS, maximum transverse diameter, maximum AP diameter and hematoma volume. Conclusion : The rate of survival after pontine hemorrhage is associated with the transverse diameter of the hematoma and more importantly the initial GCS. Long-term outcome of survivors is influenced by the initial GCS, transverse diameter, AP diameter and volume. Through the multivariate analysis, initial GCS is the only significant factor on survival. Strictly speaking, initial GCS is not modifiable. However, surgical reduction may be considered to amend theses decisive factors. Additional study for indication, timing and method of surgical management is needed.

• Clinical and Experimental Reproductive Medicine
• /
• 제31권4호
• /
• pp.235-244
• /
• 2004

Objective: The effects on spermatogenesis by expression of vascular endothelial growth factor (VEGF) and endothelin-1 (ET-1) were investigated. Materials and Methods: Testicular specimens were obtained from 40 infertile males due to primary testicular failure and from 10 fertile males with other urologic problems. The specimens of infertile males were devided into 4 groups according to histologic findings; Sertoli cell only syndrome (A), maturation arrest (B), hypospermatogenesis (C) and sloughing and disorganization (D). VEGF and ET-1 expression were detected with immunohistochemical stain. Results: VEGF expression on Leydig cell was detected in all cases. But, VEGF expression rates on germ cell were significantly higher in infertile group B, C, D compared to that of the control group (p<0.05). ET-1 expression rates on Leydig cell was significantly lower in all infertile group compared to that of the control group (p<0.05). But, ET-1 expression rates on Sertoli cell was significantly higher in all infertile group compared to that of the control group (p>0.05). In germ cell of infertile group, LH, FSH and prolactin were significantly decreased, and estradiol is increased in positive stain group on ET-1 immunohistochemical stain (p<0.05). VEGF and ET-1 expression were not correlated mean seminiferous tubule diameter (p>0.05). Conclusions: Abnormal spermatogenesis would be reflected in VEGF expression in germ cell.

• International Journal of Vascular Biomedical Engineering
• /
• 제1권1호
• /
• pp.13-23
• /
• 2003

Backgrounds: The present study in angulated coronary stenosis was to evaluate the influence of velocity and wall shear stress (WSS) on coronary atherosclerosis, the changes of hemodynamic indices following coronary stenting, as well as their effect of evolving in-stent restenosis using human in vivo hemodynamic parameters and computed simulation quantitatively and qualitatively. Methods: Initial and follow-up coronary angiographies in the patients with angulated coronary stenosis were performed (n=80). Optimal coronary stenting in angulated coronary stenosis had two models: < 50 % angle changed(model 1, n=43), > 50% angle changed group (model 2, n=37) according to percent change of vascular angle between pre- and post-intracoronary stenting. Flow-velocity wave obtained from in vivo intracoronary Doppler study data was used for in vitro numerical simulation. Spatial and temporal patterns of velocity vector and recirculation area were drawn throughout the selected segment of coronary models. WSS of pre/post-intracoronary stenting were calculated from three-dimensional computer simulation. Results: Follow-up coronary angiogram demonstrated significant difference in the percent of diameter stenosis between two groups (group 1: $40.3{\pm}30.2$ vs. group 2: $25.5{\pm}22.5%$, p<0.05). Negative WSS area on 3D simulation, which is consistent with re-circulation area of velocity vector, was noted on the inner wall of post-stenotic area before stenting. The negative WSS was disappeared after stenting. High spatial and temporal WSS before stenting fell into within physiologic WSS after stenting. This finding was prominent in Model 2 (p<0.01) Conclusions: The present study suggests that hemodynamic forces exerted by pulsatile coronary circulation termed as WSS might affect on the evolution of atherosclerosis within the angulated vascular curvature. Moreover, geometric change, such as angular difference between pre / post-intracoronary stenting might give proper information of optimal hemodynamic charateristics for vascular repair after stenting.

• 한국식품과학회지
• /
• 제20권5호
• /
• pp.650-658
• /
• 1988

발아 중인 대두와 두채 자엽부에서의 단백지 유동 현상을 광학현미경(LM)과 주사 전자현미경(TEM)을 이용하여 epidermis, vascular tissue 그리고 storage parenchyma에서 비교 관찰하였다. 발아 초기의 자엽에는 직경이 $0.1-15{\mu}m$에 해당하는 다양한 크기의 단백질 체(protein bodies)로 채워져 있었으며 epidermis와 vascular tissue의 단백질체는 parenchyma 세포보다 훨씬 적은 크기의 $0.1-5{\mu}m$였다. 발아가 진행됨에 따라, 단백질의 분해현상은 epidermis와 vascular tissue에서 먼저 시작되었다. 그 분해 유형은 먼저 침투한 수분에 의해 팽창된 단백질체의 외막에는 손상이 없어 단백질 체 내부와 외부로부터 가수분해가 일어났으며, 단백질이 완전히 분해도기 전에 단백질체 끼리의 융합 또한 관찰 되어졌다. 단백질체 분해의 결과는 세포내에 중심액포를 만든다는 것이며, 두채 성장 말기에는 액포막의 파괴현상도 관찰되었다.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1997년도 추계학술대회
• /
• pp.478-481
• /
• 1997

A technique or the preparation of porous polyurethane vascular prostheses was investigated. Small-diameter vessels are not in general clinical use due to their limited long-term biocompatibility and low patency rates in experimental trial. These limits are mainly due to the failure of mechanical unction of the vascular grafts. This failure has been suggested to result partially from compliance mismatch. The long-term patency is considered to depend critically on the properties of the material and the fabrication process of the graft. So the control of pores is very important and main points to develop a available vascular grafts. Two-kind polymer sheets was compared. One was the porous PU-sheet made at room temperature by the solvent/non-solvent exchange. And the other was the porous PU-sheet which was fabricated by thermal phase transition and solvent-/non-solvent exchange using the thermal controller. The polymer sheets had a uniform pore size and pore occupation. According to the result of the above experiments, polyurethane solution was injected into a mold designed or U-type tube. The average pore size and pore occupation were easily changed by changing polyurethane concentration, freezing temperature, and methods. This technique can give a proper pore size ($10{\sim}45\;{\mu}m$) or tissue in growth, and suitable compliances or matching with arteries and veins. Besides, the fabrication of more complicated shaped vessels such as the U-type vascular grafts is easily controlled by using the fixed mold. this method might give a desired compliant graft or artificial implantation with the presently valid medical polymers.

• Archives of Plastic Surgery
• /
• 제46권1호
• /
• pp.23-33
• /
• 2019

Background Venous malformations (VMs) are a common type of vascular malformation. However, their causes and management remain unclear, and few studies specific to VMs of the head and neck have been reported. This study describes our experiences with VMs of the head and neck. Methods This retrospective study included 82 patients who underwent treatment for head and neck VMs, among 222 who visited our vascular anomalies center. Medical records between 2003 and 2016 were reviewed to identify common features in the diagnosis and treatment. The diagnosis of suspected head and neck VMs was based on the results of imaging studies or biopsies, and the VMs were analyzed based on magnetic resonance imaging, computed tomography, and Doppler sonography findings. Results VMs were slightly more common in female patients (59.8%), and 45.1% of patients developed initial symptoms at the age of 10 or younger. Lesions were slightly more common on the right side (47.3%). The main sites involved were the cheek (27.7%) and lip area (25.5%). The muscle layer was commonly involved, in 98.7% of cases. Small lesions less than 5 cm in diameter accounted for 60.8% of cases, and well-defined types were slightly more prevalent at 55.4%. Improvement was observed in 77.1% of treated patients. Conclusions Early and accurate diagnosis and appropriate treatment according to individual symptoms are important for successful treatment of VMs. If treatment is delayed, the lesions can worsen, or recurrence becomes more likely. Therefore, VMs require a multidisciplinary approach for early and accurate diagnosis.

• The Korean Journal of Ecology
• /
• 제24권6호
• /
• pp.381-384
• /
• 2001

A preliminary comparative histodimensional studies, such as wood to bark ratio, total area of parenchyma cells and bast fibers, height and diameter of vascular rays, pith diameter and phenological parameters, height of the plant, perimeter of the stem, dry weight of the stem and leaves have been investigated for the low and high rubber bearing Guayule plants growing in same and different climatic regions of India. A plausible correlation is found between the percentage of rubber content and anatomical characters in the investigated varieties.

• Journal of Chest Surgery
• /
• 제46권5호
• /
• pp.353-356
• /
• 2013

A 74-year-old man was diagnosed with aortic root aneurysm and two-vessel coronary disease. Echocardiographic assessment revealed an enlarged sinus of Valsalva 60 mm in diameter with mild aortic regurgitation. Florida sleeve repair was performed using a vascular graft combined with coronary artery bypass grafting. The postoperative course was uncomplicated and follow-up echocardiographic evaluations showed an aortic root diameter of 38 mm without aortic insufficiency up to 1 year after surgery.