• 치과방사선
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• 제20권1호
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• pp.7-17
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• 1990

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.72-74
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• 1997

We have developed a 3-D image processing and display technique that include image resampling, modification of MIP, and fusion of MIP image and volumetric rendered image. This technique facilitates the visualization of the three-dimensional spatial relationship between vasculature and surrounding organs by overlapping the MIP image on the volumetric rendered image of the organ. We applied this technique to a MR brain image data to produce an MRI angiogram that is overlapped with 3-D volume rendered image of brain. MIP technique was used to visualize the vasculature of brain, and volume rendering was used to visualize the other structures of brain. The two images are fused after adjustment of contrast and brightness levels of each image in such a way that both the vasculature and brain structure are well visualized either by selecting the maximum value of each image or by assigning different color table to each image. The resultant image with this technique visualizes both the brain structure and vasculature simultaneously, allowing the physicians to inspect their relationship more easily. The presented technique will be useful for surgical planning for neurosurgery.

• Molecules and Cells
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• 제38권11호
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• pp.975-981
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• 2015

Precise 3D spatial mapping of cells and their connections within living tissues is required to fully understand developmental processes and neural activities. Zebrafish embryos are relatively small and optically transparent, making them the vertebrate model of choice for live in vivo imaging. However, embryonic brains cannot be imaged in their entirety by confocal or two-photon microscopy due to limitations in optical range and scanning speed. Here, we use light-sheet fluorescence microscopy to overcome these limitations and image the entire head of live transgenic zebrafish embryos. We simultaneously imaged cranial neurons and blood vessels during embryogenesis, generating comprehensive 3D maps that provide insight into the coordinated morphogenesis of the nervous system and vasculature during early development. In addition, blood cells circulating through the entire head, vagal and cardiac vasculature were also visualized at high resolution in a 3D movie. These data provide the foundation for the construction of a complete 4D atlas of zebrafish embryogenesis and neural activity.

• Journal of the Optical Society of Korea
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• 제17권1호
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• pp.86-90
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• 2013

Various methods have been proposed for enhancing the contrast of laser speckle contrast image (LSCI) in subcutaneous blood flow measurements. However, the LSCI still suffers from low image contrast due to tissue turbidity. Herein, a physicochemical tissue optical clearing (PCTOC) method was employed to enhance the contrast of LSCI. Ex vivo and in vivo experiments were performed with porcine skin samples and male ICR mice, respectively. The ex vivo LSCIs were obtained before and 90 min after the application of the PCTOC and in vivo LSCIs were obtained for 60 min after the application of the PCTOC. In order to obtain the skin recovery images, saline was applied for 30 min after the application of the PCTOC was completed. The visible appearance of the tubing under ex vivo samples and the in vivo vasculature gradually enhanced over time. The LSCI increased as a function of time after the application of the PCTOC in both ex vivo and in vivo experiments, and properly recovered to initial conditions after the application of saline in the in vivo experiment. The LSCI combined with the PCTOC was greatly enhanced even in deep vasculature. It is expected that similar results will be obtained in in vivo human studies.

• International Journal of Stem Cells
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• 제16권1호
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• pp.1-15
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• 2023

Liver organoids have gained much attention in recent years for their potential applications to liver disease modeling and pharmacologic drug screening. Liver organoids produced in vitro reflect some aspects of the in vivo physiological and pathological conditions of the liver. However, the generation of liver organoids with perfusable luminal vasculature remains a major challenge, hindering precise and effective modeling of liver diseases. Furthermore, vascularization is required for large organoids or assembloids to closely mimic the complexity of tissue architecture without cell death in the core region. A few studies have successfully generated liver organoids with endothelial cell networks, but most of these vascular networks produced luminal structures after being transplanted into tissues of host animals. Therefore, formation of luminal vasculature is an unmet need to overcome the limitation of liver organoids as an in vitro model investigating different acute and chronic liver diseases. Here, we provide an overview of the unique features of hepatic vasculature under pathophysiological conditions and summarize the biochemical and biophysical cues that drive vasculogenesis and angiogenesis in vitro. We also highlight recent progress in generating vascularized liver organoids in vitro and discuss potential strategies that may enable the generation of perfusable luminal vasculature in liver organoids.

• Clinics in Shoulder and Elbow
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• 제27권2호
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• pp.203-211
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• 2024

Background: Little is known about alterations of the rotator cuff (RC) macroscopic vasculature associated with medical conditions and/or habits that predispose a person to diseases of the peripheral microcirculation. The high frequency of cuff tear and re-tear in patients with diabetes, hypercholesterolemia, uncontrolled arterial hypertension, or metabolic syndrome may be due to tissue hypovascularity. Methods: The macroscopic vasculature of both the articular and bursal sides of the posterosuperior RC was evaluated arthroscopically in 107 patients (mean age, 58.2 years) with no RC tear. Patients were divided into three groups according to medical comorbidities and lifestyle factors (group I, none; group II, smokers and/or drinkers and one comorbidity; and group III, two or more comorbidities). Pulsating vessels originating from both the myotendinous and osteotendinous junctions were assessed as "clearly evident," "poorly evident," or "not evident." Results: Groups I, II, and III comprised 36, 45, and 26 patients, respectively. Within the myotendinous junction, vessels were visualized in 22 group I patients (61%), 25 group II patients (55%), and 6 group III patients (23%) (P=0.007). Pulsating arterial vessels originating from the osteotendinous junction were seen in 42%, 36%, and 0% of patients, respectively (P<0.001). Within the bursal side of the RC, a dense anastomotic network was visualized (either clearly or poorly) in 94% (34), 80% (36), and 35% (9) of patients, respectively (P<0.001). Conclusions: The macroscopic vasculature of the RC is influenced by pre-existing diseases and lifestyle factors, which may impair peripheral microcirculation.

• Journal of Trauma and Injury
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• 제37권3호
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• pp.233-237
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• 2024

Bullet embolism is a potential complication of a gunshot wound, especially with a low-velocity missile. This is because the trajectory of the low-velocity bullet can be significantly slowed as it passes through tissue. An unusual form of travel can occur in which the bullet enters the vasculature but does not have enough kinetic energy to create a through-and-through wound, leading it to remain inside the vasculature. Once inside the vasculature, the bullet could migrate to different parts of the body, potentially causing complications such as ischemia, becoming a source of thromboembolism, or functioning as a nidus for infection. The management of a bullet embolism varies from case to case, as each patient with this issue has a unique body habitus that can result in infinite possibilities of the trajectory and destination of the bullet embolus. Additional damage to surrounding vasculature or tissue can occur, as well as embolization of the bullet to critical areas of the body. Here we present the case of a 72-year-old man who had a self-inflicted gunshot wound to the chest with a low-velocity bullet, which penetrated the right atrium of the heart. It traveled into the venous vasculature through the right atrium, into the inferior vena cava, and eventually settled in the right internal iliac vein. He refused further intervention and management after initial workup and resuscitation.

• 대한방사선기술학회지:방사선기술과학
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• 제33권3호
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• pp.223-230
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• 2010

본 연구에서는 MRI와 MRA를 이용하여 우리나라 사람의 뇌혈관 질환 중 뇌혈관의 파열에 의한 뇌혈관 질환을 제외하고 뇌혈관이 좁아지거나 막힌 허혈성 뇌혈관 질환의 분포(호발부위)를 분석하여 임상에서 활용할 수 있도록 하였다. 뇌혈관이 좁아지거나 막힌 허혈성 뇌혈관 질환만의 분포를 분석한 이유는 뇌혈관의 파열에 의한 출혈성 뇌혈관 질환과 뇌경색(brain infarction) 등 허혈성 뇌혈관 질환의 발생학적 기전(mechanism)이 다르기 때문이며 그 결과는 아래와 같다. 1. 연구대상자 총 626명 중 성별로는 남자가 55.0%로 여자 45.0%보다 높은 분포를 보였다. 2. 위치별 허혈성 뇌혈관 질환의 분포에서 우측 뇌혈관이 37.5%로 가장 많았으며, 좌측 뇌혈관 35.1%, 양쪽 뇌혈관 27.3% 순으로 나타났다. 3. 허혈성 뇌혈관 질환의 뇌혈관 별 분포는 ICA가 38.9%로 가장 많았으며, 다음으로 MCA 35.7%, PCA 13.4%, ACA 6.0%, VA 3.3% 순으로 나타났다. 4. A-com에 질환이 있는 경우는 한 명도 없었으며 P-com 에도 남자 1명만이 발생했다. 5. MCA에는 여자가 54.6%로 남자 42.2%보다 많아, 성별에 따라 통계적으로 유의미한 차이를 보였다($x^2$=9.64, p < .01). 6. ICA에서는 남자가 56.4%로 여자 46.8%보다 많아 통계적으로 유의미한 차이를 보였다($x^2$=5.71, p < .05). 7. BA에서도 남자가 2.3%로 여자 0.4%보다 많아 성별에 따라 유의미한 차이를 보였다($x^2$=4.25, p < .05). 8. 연령에 따른 혈관별 질환의 분포에 대한 차이는 없었으며 협착과 폐색의 분포에서는 폐색보다 협착이 많았다.

• 대한치과교정학회지
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• 제24권1호
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• pp.37-62
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• 1994

This study was undertaken to investigate the three dimensional vascular changes of periodontal ligament following orthodontic tooth movement. Experimental tooth movement was carried out in 96 Sprague-Dawley rats with the weight of 250g. They were divided into four experimental groups (each 24 rats). The left maxillary first molar was moved mesially with 25g force in group I, and with 75g force in group II. Each three animals were sacrificed after 1, 6, 12, 24 hours, and 3, 7, 14, 21 days. In group III, 25g mesial force was applied for 3 days, and in group IV, 75g mesial force was applied for 3 days. Then the appliances were removed, and each three animals were sacrificed after 1, 6, 12, 24 hours, and 3, 7, 14, 21 days from removal of appliance. The contralateral molars were used for control group. Casting media was injected via left ventricle and polymerized in warm water. After corrosion of surrounding soft tissue, three dimensional vascular changes were examined using scanning electron microscopy. The findings of this study were as follows: 1. Pressure side of group I and II showed degenerative vascular changes such as vascular compression, reduction of vasculature, leakage of casting media. But, regenerative changes were dominant after 7 days of tooth movement. Although the degenerative vascular changes were more severe in group II, which was exposed to heavy force, the timing of these changes was not different between two groups. 2. Periodontal vasculature was reestablished by the growth of new capillaries and their differentiation and union from the remaining periodontal vessels and vessels of alveolar bone marrow. Although vascular regeneration was more rapid in group I, which was exposed to light force, the vasculature was not fully normalized in both groups even after 21 days. 3. There was no remarkable changes in tension side of group I and II, but looping of capillary, new capillary growth, dilation of vessels, redirection of vessels in the direction of tensile force were occurred. 4. In pressure side of group III and IV, in which appliance was removed after 3 days of orthodontic force, bone resorption was continued even after removal of appliance. Regeneration of vasculature was initiated after 1-6 hours, and it was more rapid in group III than group IV. In both groups, the vasculature was not fully normalized even after 21 days. 5. After removal of appliance, tension side of group III and IV showed vascular compression and loss of vasculature.

• 치과방사선
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• 제20권1호
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• pp.41-49
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• 1990

The author observed the changes of vasculature of pre-and post-irradiation on DMBA induced rat tongue cancer. The study was performed by using vascular corrosion resin casting, and scanning electron microscopy. The results were as follows. 1. The capillaries runned parallely and formed bundles and, sometimes, plexus. The endothelial cells were arranged regularly and small pores were observed. 2. In irradiated normal tongue the capillaries were curved slightly and formed plexus on initial day of post-irradiation. On third day the capillaries and capillary pores were dilated and the endothelial cell arrangement was irregular. The effects of irradiation were gradually increased from initial to the 3rd day, though it was decreased after 7th day. 3. The vasculature of DMBA induced tongue cancer group were very irregular, and large avascular lesions were formed according to the cancer necrosis or tumor cell nest and the vasculature was narrowed and paralleled around the avascular lesion by compression of cancer cell nest. The vascular wall was roughened and dilated, forming club shaped or varix. 4. The vessels were curved and formed reticular network in irradiated DMBA induced tongue carinoma group. The free end of newly formed capillaries had regular width, and also irregular club shaped or aneurysmal dilatation were observed. The vascular structures were destroyed and vessels were fused in tumor necrosis lesion. The radiation effects were marked on the first and third day of irradiation and the effects were decreased after seventh day and showed capillary regeneration.