Microbial synthesis of hydroxytyrosol and hydroxysalidroside

추혜정,김은지,김소연,이영심,김봉규,안중훈 한국응용생명화학회 2018 Applied Biological Chemistry (Appl Biol Chem) Vol.61 No.3

Plant-derived phenolic compounds, such as hydroxytyrosol and hydroxysalidroside, have a beneficial impact on human health owing to their antioxidant activity. In this study, we used Escherichia coli to synthesize hydroxytyrosol. Tyrosine decarboxylase from Papaver somniferum, tyrosine oxidase from Micrococcus luteus, and 4-hydroxyphenylacetate 3-monooxygenase from E. coli were transformed into the bacterial cell. The resulting transformant successfully synthesized hydroxytyrosol. Furthermore, we used the engineered E. coli strains to synthesize * 268.3 mg/L hydroxytyrosol. Three uridine diphosphate-dependent glycosyltransferases (UGTs), which were previously shown to convert tyrosol into salidroside, were tested to synthesize hydroxysalidroside, and one of UGTs was used to synthesize hydroxysalidroside from hydroxytyrosol. Finally, E. coli harboring this UGT converted approximately 50% of hydroxytyrosol into hydroxysalidroside.

MR 영상에서의 금속 인공물과 감소방법

추혜정,이선주,이영한 대한영상의학회 2020 대한영상의학회지 Vol.81 No.1

Metallic artifacts on MR imaging are typically induced by differences in magnetic susceptibility between the metallic implant and surrounding tissue. Conventional techniques for metal artifact reduction require MR machines with low field strength, shift in the frequency-encoding and phase-encoding directions according to the axis of metallic implant, increased receiver bandwidth and matrix, decreased slice thickness, and utilization of the short tau inversion recovery or Dixon method for fat-suppression. Slice-encoding for metal artifact correction and multi-acquisition variable-resonance image combination can dramatically reduce the number of metallic artifacts. However, these sequences have a considerably long acquisition time. Furthermore, the recently developed acceleration techniques including compressed sensing can solve this problem. MR 영상에서 금속 인공물은 금속 삽입물과 주변 조직의 magnetic susceptibility의 차이에의해 나타난다. 금속 인공물을 줄이는 일반적인 방법은 낮은 자장의 MR 장비를 사용하고, 금속물의 방향에 따라 주파수부호화 방향과 위상부호화 방향을 바꾸고, receiver bandwidth와matrix를 높이며, 절편 두께를 작게 하고 short tau inversion recovery나 Dixon 기법을 사용하여 fat-suppression을 하는 것이다. Slice-encoding for metal artifact correction이나multi-acquisition variable-resonance image combination을 통해 보다 강력하게 금속 인공물을 줄일 수 있다. 그러나 이 방법의 최대 단점은 촬영 시간이 길다는 것이나 최근 개발된compressed sensing과 같은 고속화 기법을 통해 이를 해결할 수 있게 되었다.

T2 강조 MR 영상에서 저신호강도를 보이는 윤활막 질환

추혜정,이선주,조길호,서경진,이성문,이영환,이인숙,이경규,김보미 대한자기공명의과학회 2011 Investigative Magnetic Resonance Imaging Vol.15 No.1

Pigmented villonodular synovitis, synovial chondromatosis, long-standing rheumatoid arthritis, hemophilic arthropathy, chronic tophaceous gout, amyloid arthropathy, tuberculous arthritis, and hemangioma are the synovial diseases showing low signal intensity on T2-weighted image. Synovial deposition of hemosiderin, urate, and amyloid and fibrosis or caseous necrosis of hypertrophied synovium are known as the pathologic causes of T2 signal intensity. Because of the low incidence of the synovial lesions showing T2 low signal intensity, recognition of these diseases would be helpful for the exact diagnosis. 색소성 융모결절성 윤활막염, 윤활막 연골종증, 장기간의 류마티스 관절염, 혈우병성 관절병증, 만성 결절성 통풍, 아밀로이드성 관절병증, 결핵성 관절염, 그리고 혈관종 등은 T2 강조 MR 영상에서 저신호강도를 보인다. 혈철소, 요산, 아밀로이드의 윤활막 침착, 증식된 윤활막의 섬유화, 치즈괴사 등이 T2 저신호강도의 병리적 원인으로 알려져 있다. T2 강조영상에서 저신호강도를 보이는 윤활막 질환의 빈도는 낮으므로 이에 대한 숙지는 질환의 정확한 진단에 도움을 줄 것이다.

Radiologic Features of Fibrous Hamartoma of Infancy Involving the Buttocks

추혜정,이선주,윤혜경,이은주,김숙정,김명희,은충기 대한초음파의학회 2009 ULTRASONOGRAPHY Vol.28 No.1

Fibrous hamartoma of infancy (FHI) is a rare benign subcutaneous tumor that presents in children younger than two years. The tumor mostly affects the trunk, axilla and upper extremities. Imaging findings of FHI that involve the buttocks have not been reported in the clinical literature. We reported the imaging features of a lesion in a 9-month-old infant who presented with a palpable mass on the buttocks. The imaging findings were evaluated after a review of previous studies.

Ultrasonographic features of vascular closure devices: initial and 6-month follow-up results

추혜정,정해웅,박진영,진성철,김성태,서정화,이선주,박영미 대한초음파의학회 2014 ULTRASONOGRAPHY Vol.33 No.4

Purpose: This study aimed to evaluate the ultrasonographic findings for various types of vascularclosure devices (VCDs) immediately after the angiographic procedure and at 6-month follow-up. Methods: We included 18 VCDs including Angio-Seal (n=4), FemoSeal (n=8), ExoSeal (n=3),Perclose (n=2), and StarClose (n=1) in this study. Four patients were implanted with 2 VCDs atthe each side of bilateral femoral arteries, while the remaining 8 patients were inserted 1 VCDat the right femoral artery. Ultrasonography was performed within 10 days and at approximately6 months after the angiographic procedure. Ultrasonographic morphology of the attached VCDand its relationship with the arterial wall were analyzed. Results: Initial ultrasonography revealed the attached VCD as the relevant unique structurewith successful deployment and hemostasis. Follow-up ultrasonography demonstrated partialabsorption of hemostatic materials in cases of Angio-Seal (n=3), FemoSeal (n=5), and ExoSeal(n=3), changes in the soft tissue surrounding the femoral artery in case of Angio-Seal (n=1),arterial intimal hyperplasia in cases of FemoSeal (n=3), and no gross changes as compared withthe initial ultrasonographic findings in cases of Perclose (n=2) and StarClose (n=1). Conclusion: Initial ultrasonographic evaluation reflected the unique structure of each VCD, withmost of them being easily distinguishable. Follow-up ultrasonography revealed various changesin the affected vessels.

Perianal Mucinous Adenocarcinoma with an Emphasis on the MR Imaging Features: A Case Report

추혜정,이선주,이재화,장내성,윤희자,이은주 대한영상의학회 2010 대한영상의학회지 Vol.62 No.5

An 80-year-old man, who presented with a perianal mass, showed a multilocular mass with peripheral calcification in the retroanal region at CT. The MR imaging detected a mass invading into the posterior aspect of the external anal sphincter, and was shown as having a high T1 and T2 signal intensity with a different T1 signal intensity in each locule. After contrast injection, septal and peripheral enhancement of the tumor was observed. Surgery was performed and revealed a perianal mucinous adenocarcinoma. To the best of our knowledge, this is the first report describing the MR features of a perianal mucinous adenocarcinoma in the Korean literature. We described a case of perianal mucinous adenocarcinoma with an emphasis on the MR imaging features.

Ankle MRI for Anterolateral Soft Tissue Impingement: Increased Accuracy with the Use of Contrast-Enhanced Fat-Suppressed 3D-FSPGR MRI

추혜정,서진석,김성준,허용민,김명인,이진우 대한영상의학회 2008 Korean Journal of Radiology Vol.9 No.5

Objective: To validate the use of contrast-enhanced (CE) fat-suppressed three-dimensional (3D) fast gradient-recalled acquisition in the steady state with radiofrequency spoiling (FSPGR) magnetic resonance imaging (MRI) for the diagnosis of anterolateral soft tissue impingement of the ankle, as compared to the use of routine ankle MRI. Materials and Methods: Contrast-enhanced fat-suppressed 3D-FSPGR MRI and routine MRI scans were retrospectively reviewed for 45 patients with arthroscopically proven anterolateral impingement. In addition, scans were reviewed in 45 control subjects with diagnoses other than impingement. Two radiologists independently reviewed the two sets of images in random order. Using areas (Az) under the receiver operating characteristic curve (ROC), we compared the depiction of anterolateral soft tissue impingement in the two sets of images. Results: The overall accuracy for lesion characterization was significantly higher (p < 0.05) using the CE fat-suppressed 3D-FSPGR MR images (Az = 0.892 and 0.881 for reader 1 and 2, respectively) than using the routine MR images (Az = 0.763 and 0.745). The use of CE fat-suppressed 3D-FSPGR MRI enhanced impingement depiction in most cases. However, in cases with a thickened nonenhancing scar or joint effusion, the routine images better depicted a soft tissue mass that intruded into anterolateral gutter than the CE images. Conclusion: The use of CE fat-suppressed 3D-FSPGR MRI of the ankle allows a more accurate assessment of anterolateral soft tissue impingement of the ankle, as compared to the use of routine MRI. Objective: To validate the use of contrast-enhanced (CE) fat-suppressed three-dimensional (3D) fast gradient-recalled acquisition in the steady state with radiofrequency spoiling (FSPGR) magnetic resonance imaging (MRI) for the diagnosis of anterolateral soft tissue impingement of the ankle, as compared to the use of routine ankle MRI. Materials and Methods: Contrast-enhanced fat-suppressed 3D-FSPGR MRI and routine MRI scans were retrospectively reviewed for 45 patients with arthroscopically proven anterolateral impingement. In addition, scans were reviewed in 45 control subjects with diagnoses other than impingement. Two radiologists independently reviewed the two sets of images in random order. Using areas (Az) under the receiver operating characteristic curve (ROC), we compared the depiction of anterolateral soft tissue impingement in the two sets of images. Results: The overall accuracy for lesion characterization was significantly higher (p < 0.05) using the CE fat-suppressed 3D-FSPGR MR images (Az = 0.892 and 0.881 for reader 1 and 2, respectively) than using the routine MR images (Az = 0.763 and 0.745). The use of CE fat-suppressed 3D-FSPGR MRI enhanced impingement depiction in most cases. However, in cases with a thickened nonenhancing scar or joint effusion, the routine images better depicted a soft tissue mass that intruded into anterolateral gutter than the CE images. Conclusion: The use of CE fat-suppressed 3D-FSPGR MRI of the ankle allows a more accurate assessment of anterolateral soft tissue impingement of the ankle, as compared to the use of routine MRI.

Cervical Spine CT Using Spectral Shaping: Can It Be a Solution to Overcome Artifacts in the Lower Cervical Spinal Region?

이수민,추혜정,이선주,김성관,In Sook Lee,김동욱,Jin Wook Baek,허영진 대한영상의학회 2019 Korean Journal of Radiology Vol.20 No.3

Objective: To investigate the image quality, radiation dose, and intermodality agreement of cervical spine CT using spectral shaping at 140 kVp by a tin filter (Sn140-kVp) in comparison with those of conventional CT at 120 kVp. Materials and Methods: Patients who had undergone cervical spine CT with Sn140-kVp (n = 58) and conventional 120 kVp (n = 49) were included. Qualitative image quality was analyzed using a 5-point Likert scale. Quantitative image quality was assessed by measuring the noise and attenuation within the central spinal canals at C3/4, C6/7, and C7/T1 levels. Radiation doses received by patients were estimated. The intermodality agreement for disc morphology between CT and MRI was assessed at C3/4, C5/6, C6/7, and C7/T1 levels in 75 patients who had undergone cervical spine MRI as well as CT. Results: Qualitative image quality was significantly superior in Sn140-kVp scans than in the conventional scans (p < 0.001). At C7/T1 level, the noise was significantly lower and the decrease in attenuation was significantly less in Sn140-kVp scans, than in the conventional scans (p < 0.001). Radiation doses were significantly reduced in Sn140-kVp scans by 50% (effective dose: 1.0 ± 0.1 mSv vs. 2.0 ± 0.4 mSv; p < 0.001). Intermodality agreement in the lower cervical spine region tended to be better in Sn140-kVp acquisitions than in the conventional acquisitions. Conclusion: Cervical spine CT using Sn140-kVp improves image quality of the lower cervical region without increasing the radiation dose. Thus, this protocol can be helpful to overcome the artifacts in the lower cervical spine CT images.

금속이 담지된 메조기공 실리카 촉매상에서 2-butanol 탈수 반응 Kinetics 연구

김현아,추혜정,최현희,전종기 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1

바이오부탄올은 화학 산업의 발전과 원료 다변화에 대한 대체재로 주목받고 있으며, 바이오리파이너리를 통해 고부가가치의 화학제품을 생산할 수 있다. 본 연구에서는 금속이 고분산된 메조기공 실리카 촉매상에서 2-butanol 탈수반응의 Kinetics를 정립하는 것이 목표이다. 이 연구에서는 MCM-41, 상업용 ferrierite로부터 제조한 메조기공 촉매(MMZ-FER), WO₃/MCM-41 및 WO₃/MMZFER촉매를 이용하여, 2-butanol 탈수반응에 대한 kinetics 연구를 수행하였다. 촉매 특성 분석 방법은 BET, Ammonia-TPD, Pyridine-IR, XRD 등을 이용하였다, 탈수반응을 통하여 2-butanol의 전환율, 1-butene에 대한 선택도, 수율을 구하고, Power Law Model과 Langmuir-Hinshelwood Model의 parameter를 선정하였다.

Ultrasonographic Findings of Subcutaneous Angioleiomyomas in the Extremities Based on Pathologic Subtypes

김동건,이선주,추혜정,김성관,차장규,박희진,권종원,김태은,정수진 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.4

Objective: The purpose of this study was to describe the ultrasonographic findings of angioleiomyoma based on pathological subtypes. Materials and Methods: Thirty-nine patients with subcutaneous angioleiomyomas in the extremities were retrospectively reviewed by two radiologists and a pathologist. Sonographic images were analyzed to evaluate each tumor’s anatomic location, size, shape, margin, heterogeneity, echogenicity, associated findings, and vascularity. Results: Angioleiomyomas were divided into 3 subtypes: capillary (n = 16), venous (n = 22), and cavernous (n = 1). The one cavernous angioleiomyoma was a hypoechoic mass with rich vascularity. Hypoechogenicity was more frequently observed for venous tumors (77.3%) than for capillary tumors (43.8%), and isoechogenicity was more frequently observed for capillary tumors (56.2%) than for venous tumors (22.7%). Moderate vascularity was more frequently observed for venous tumors (59.1%) than for capillary tumors (12.5%), and little vascularity was more frequently observed for capillary tumors (62.5%) than for venous tumors (13.6%). The aforementioned findings including echogenicity (p = 0.034) and vascularity (p = 0.003) were statistically significant. Conclusion: Awareness of sonographic findings of angioleiomyomas based on pathologic subtypes could be helpful for diagnosing angioleiomyoma and could increase diagnostic accuracy for superficial soft-tissue masses in our practice.