토끼의 만성 뇌혈관연축 모델에서 혈관확장제에 의한 비가역적 혈관수축의 발현시기와 혈관벽의 전자현미경소견상 이상소견이 발현되는 시기와의 시간관계

정천기,조병규,김하영,지제근,김종재,한대희 대한신경외과학회 1995 Journal of Korean neurosurgical society Vol.24 No.11

One of the characteristics of the cerebral vasospasm is its irreversibility with the vasodilators.Under the hypothesis that the irreversibility with vasodilators might be caused by the structural change in the arterial wall, authors examined the chronological relationships between the irreversibility and the electron microscopic findings of the arterial wall in the rabbit chronic vasospasm model. The development of the vasospasm and the irreversibility of the vasospasm with the intra-arterial papaverine were defined angiographically. After the second angiography done in one to 30 days after subarachnoid hemorrhage(SAH), eighteen rabbits were sacrificed, and the basilar artery was examined with electron microscope. Arterial narrowing was the severest one day after SAH(54.1% of the pre-SAH diameter), and was maintained up to 30 days afer SAH. The irreversibility of the arterial constriction with the papaverine developed 5 days after SAH, which had a tendency to recover 6 to 9 days after SAH. However the irreversibility was noted again 16 days after SAH. Electron microscopy revealed the endothelial wrinkling, disorganization of muscle fiber, myonecrosis, thickening of smooth muscle fibers, and increase of connective tissue in the tunica media. These structural changes were severest one day after SAH, and gradually diminished up to 30 days after SAH. These data show that there are no chronological relationships between the irreversibility and the structural change per se. However the fact that the irreversibility developed during the reparative phase of the arterial wall injury by SAH suggests that the chronic vasospasm is not a primary event but a secondary phenomenon following an injury to the cerebral arterial wall.

직렬 리액터를 이용한 계통연계형 태양광 발전 시스템

金大均,鄭春炳,全基英,李丞煥,吳鳳煥,李勳九,金容珠,韓慶熙 명지대학교 산업기술연구소 2005 産業技術硏究所論文集 Vol.24 No.-

Since the residential load is an AC load and the output of solar cell is a DC power, the photovoltaic system needs the DC/AC converter to utilize solar cell. In case of driving to interact with utility line, in order to operate at unity power factor, converter must provide the sinusoidal wave current and voltage with same phase of utility line. Since output of solar cell is greatly fluctuated by insolation, it is necessary that the operation of solar cell output in the range of the vicinity of maximum power point. In this paper, DC/AC converter is three phase PWM converter with smoothing reactor. And then, feedforward control used to obtain a superior characteristic for current control and digital PLL circuit used to detect the phase of utility line.

신경세포이주장애질환을 가진 간질환자에 대한 수술 체험

황승균,정천기,오창완,이상건,지제근,김현집,한대희,이상복 대한신경외과학회 1996 Journal of Korean neurosurgical society Vol.25 No.3

Neuronal migration disorders(NMD's) are a rare group of development structural lesions characterized by disorganization of cortical architecture with aberrant columnar and laminar neuronal arrangement, often causing intractable seizures. During September 1994 to February 1995, we operated on six patients with NMD to treat intractable seizures. Male to female ratio of these 6 patients was 2 : 4, and mean age at seizure onset was 14 years old(range 6-28 years), indicating early onset of epilepsy. Mean age at seizure surgery was 29 years old(range 23-41 years), and mean follow-up duration after operation was 4 months(range 3-6 months). In their past medical history, three patients had experienced febrile seizure at pediatric age, and one of them had a history of anoxic damage during delivery. Following preoperative localization, the lesion was removed completely in five patients. In the other one patient, part of the lesion was located in the speech and motor area, leading to partial removal. On histologic examination two of them showed cortical dysplasia and the other four revealed microdysgenesis. During follow-up for six months, five patients were free of seizure and in the other one patient, whose lesion was removed incompletely, the frequency of seizure decreased by 95%.

내측두엽간질과 신피질 간질에서 간질 발작이 해마에 미치는 영향 : 자기공명분광 연구 MR Spectroscopy Study

김동욱,이상건,정천기,송인찬,장기현 대한간질학회 2004 대한간질학회지 Vol.8 No.1

Outcome of Poor Grade Subarachnoid Hemorrhage Patients : Relationship to Timing of Surgery

Chung, Chun-Kee,Han, Dae Hee 대한신경외과학회 1994 Journal of Korean neurosurgical society Vol.23 No.7

입원시 임상적으로 중증인 뇌지주막하 출혈환자의 치료시기는 논란이 많다. 즉, 가능한한 조기에 동맥류의 결찰을 시행하는 것은 재출혈의 위험을 줄일 수 있으나 수술자체가 뇌손상을 일으킬 수 있고, 반면에 수술로 인한 뇌손상을 줄이기 위해 수술을 지연시킬 경우, 재출혈의 위험은 증가한다. 따라서 수술을 어느 시기에 하는 것이 수술로 인한 뇌손상과 재출혈의 위험을 최소화할 수 있는가하는 의문이 생긴다. 따라서 본 서울대학교병원 신경외과에서는 중증의 뇌지주막하 출혈 환자들의 자연 유병 경과와 수술시기에 따른 치료결과를 분석하여 그 최적 수술시기를 규명하기 위하여, 1983년부터 1991년까지 치험한 뇌지주막하 출혈 환자 476명중 입원당시 임상적으로 Hunt-Hess Ⅲ내지 Ⅴ등급에 해당했던 131례를 분석하였다. 그중 90례가 Ⅲ등급, 30례는 Ⅳ등급이었고, Ⅴ등급에 해당하는 환자는 11례였다. 분석을 위한 수술시기의 구분은 조기수술(지주막하 출혈후 1~3일), 중간수술(4~14일), 지연수술(14일 이후)로 하였다. 이와 같은 수술시기에 따르면 조기수술을 시행한 경우가 17례, 중간수술이 31례, 지연수술이 54례였고, 29례는 수술을 시행하지 못한 비수술군이었다. 중증의 지주막하 출혈환자의 자연경과는, 3일이상 경과후 수술을 받은 군에서는, 수술전까지 21%에서 임상경과의 호전을 보였고, 58.5%가 지속적인 상태를 유지하였으며, 25.5%에서 임상적으로 악화되었다. 조기수술을 시행한 군의 경우에는 수술시기까지의 임상경과가 각각 호전이 11.8%, 유지 76.4%, 악화 11.8%이었까다. 이들 각군간의 이환율과 사망율을 비교분석하기 위하여 통계처리를 하였다. 통계처리는 카이-스퀘어 검증과 휘셔씨 적확검정을 이용하였다. 이들 각군간의 치료성적에 영향을 미칠 수 있는 기타변수들인 동반질환의 유무, 뇌동맥류의 위치, 휘셔씨(뇌 전산화 단층 촬영상 뇌지주막하 출혈정도)등급, 수두증이나 혈관연축등 합병증의 발생여부등은 통계적으로 각군간에 차이가 없었다. 분석결과 비수술군에 비해 수술군 전체의 사망율이 72.4% 대 11.8%로 낮았으며 이는 통계적으로 의미있었다(p<0.0001). 또한 수술시기에 따라 사망율의 차이가 관찰되었다. 각 수술시기에 따른 군간의 사망율은 조기수술에서 52.9%, 중간 및 지연수술에서 3.5%로, 조기수술군에서 유의하게 높았고(p<0.0001), 중간수술(6.5%)과 지연수술(1.9%) 군간에서는 차이가 없었다. 이환율은 글래스고우 결과 등급상 중증장애와 식물상태로 정의하였으며 이에 대하여 수술군대 비수술군, 수술군에서 수술시기에 따른 세군간의 비교분석을 해보았으나 통계적 유의성을 발견하지 못했다. 이환 및 사망의 원인을 분석해보며 조기 수술군에서는 뇌부종이 가장 큰 요인이었고, 중간 및 지연수술군에서는 재출혈, 수두증 및 혈관연축둥이 주요인이 되었다. 이상과 같은 분석에 따르면, 결론적으로 중중의 뇌지주막하 출혈 환자를 치료하게 될 때, 발병직후 3일이내의 조기수술은 권유하기 어렵다고 판단되나 3일 이후에는 재출혈등의 합병증의 발생을 방지하기 위하여, 가능한 한 빠른 시기에 수술을 시행하여야만 되겠다. 왜냐하면 이 시기이후에는 이환 및 사망율의 차이는 없기 때문이다. In order to define the hospital course and the best surgical timing for the poor grade subarachnoid hemorrhage(SAH) patients, 131 patiedfrom 1989 to 1991) whose clinical grade on admission were Hunt and Hess grade Ⅲ to Ⅴ were analyzed. Their admission grades was Ⅲ(90 patients), Ⅳ(30 patients), and Ⅴ(11 patients). Patients were grouped into the early surgery group(within 3 days of the last hemorrhage), the intermediate group(4 to 14 days), the late surgery group(l4 days after the last hemorrhage), and non-surgical group. Early surgery was performed on 17 patients, intermediate on 31 patients, and late on 54 patients. Twenty-nine patients did not undergo surgery. This non-surgical group had a high mortality rate(72.4%). During the waiting period for a delayed surgery(later than 3 days), 21% improved their clinical state, 53.5% were stationary and 25.5% became worse. Morbidity and mortality were compared among these three surgical groups and the nonsurgical group, with statistical analysis using chi square test and Fisher's exact test. No statistical differences were noted between the management groups in terms of associated disease, location of aneurysms. Fisher's grade, Occurrence of hydrocephalus or symptomatic vasospasm. The mortality rate was significantly lower in the combined surgical groups than in the non-surgical Mortality was related to the timing of surgery. It was higher after early surgery than in the other two groups, but it was not different between the intermediate and late surgery groups. Morbidity was not different among the three surgery groups. The major cause of morbidity and mortality in the early surgery group was brain swelling, while rebleeding hydrocephalus, and vasospasm were the main causes in the intermediate and delayed surgery groups. It is concluded that it is not recommended that the early surgery must be done in all the poor grade S A H patients. However three days after the last hemorrhage, it is better to perform surgery as soon as possible, because there were no statistically significant differences between the intermediate group and the late surgery groups in the mortality and the morbidity rates.

The Timming of Anterior Communicating Artery Aneurysm Surgery: Comparison of Outcome in Early Versus Intermediate Surgery

Chung, Chun Kee,Han, Dae Hee Seoul National University 1992 The seoul journal of medicine Vol.33 No.4

부하전류 전향보상기를 이용한 강압쵸퍼의 동특성 제어

정춘병(Chun-Byung Chung),전지용(Ji-Yong Chun),전기영(Kee-Young Jeon),한경희(Kyung-Hee Han) 한국조명·전기설비학회 2008 한국조명·전기설비학회 학술대회논문집 Vol.2008 No.5월

In this paper, The author present a load current feed-forward compensator by method that improve voltage controller of Step-down Chopper to get stable output voltage to sudden change of load current. To confirm the characteristicsof a presented load current feed-forward compensator compared each transfer function of whole system that load current feed-forward compensator is added with transfer function of whole system that existent voltage controller is included using Mason gains formula in Root locus and Bode diagram. As a result the pole of system is improved, extreme point of the wave and system improves, and size of peak value and phase margin of break frequency in resonance frequency confirmed that is good. Therefore, presented control technique could confirm that reduce influence by perturbation and improves stationary state and dynamic characteristics in output of Step-down Chopper.

주사로 오인한 전구 B세포 림프모구성 림프종

한은천 ( Eun Chun Han ),김도영 ( Do Young Kim ),정진영 ( Jin Young Chung ),정혜진 ( Hye Jin Chung ),정기양 ( Kee Yang Chung ) 대한피부과학회 2008 대한피부과학회지 Vol.46 No.2

Precursor B-cell lymphoblastic lymphoma is a rare type of non-Hodgkin`s lymphoma seen exclusively in children and young adults. The neoplasm is rare in old age. We report a case of a 58-year-old male, who presented with variable-sized, erythematous to brownish papules and plaques on the scalp and face. There were no other symptoms. Pathological examination showed non-specific, sparse superficial and deep perivascular lymphocyte infiltration. We diagnosed the condition as rosacea and prescribed 100 mg of minocycline per day for 10 days. When he was seen 10 days later, his skin lesions were aggravated and re-biopsy was completed. Histopathology revealed diffuse infiltrates of small to medium-sized lymphoid cells with blastic nuclear chromatin and a high mitotic rate. Immunohistochemical study showed that infiltrated lymphoid cells were precursor B-cell type. Physical examination and staging work-up revealed extensive involvement of lymphoma in bilateral kidney, heart, pancreas, axial and proximal appendicular bones, scalp and cervical lymph node. The patient is being treated with combination chemotherapy. (Korean J Dermatol 2008;46(2):264∼267)

전격성간염에 병발한 중증재생불량성 빈혈 보고

정규원(Kyu Won Chung),정환국(Whan Kook Chung),선희식(Hee Sik Sun),정인식(In Sik Chung),이흥현(Heung Hyun Lee),이만영(Man Young Lee),김용수(Yong Soo Kim),김춘추(Chun Choo Kim),김병기(Byung Kee Kim) 대한소화기학회 1984 대한소화기학회지 Vol.16 No.2

Aplastic anemia is rare, severe complication of viral hepatitis. Over 200 cases have been reported in the literature, but only recently the virological studies have been carefully implicated. There have been reports of fatal aplastic anemia associated with type-A virus, type-B virus and non-A, non-B hepatitis. We report a 35-year-old man, who found to have severe aplastic anemia associated with fulminant hepatitis: Virological studies suggested that it was probably non-A, non-B hepatitis.

뇌동맥류 환자의 뇌전산화단층촬영소견과 뇌동맥연축과의 관계에 대한 연구

정천기,한대희 대한신경외과학회 1986 Journal of Korean neurosurgical society Vol.15 No.1

Authors reviewed the relationship between the cerebral vasospasm in the cerebral angiograms and CT findinge in the 41 cases of subarachnoid hemorrhage due to intracranial aneurysmal rupture during the period from July 1982 to February 1984. This study was based upon the CT scans performed within the first 5 days and angiograms obtained between 7 and 17 days after subarachnoid hemorrhage. Conclusions were as following: 1) No relationship between the site of aneurysm and the amount of subarachnoid blood. 2) No relationship between the site of aneurysm and the development of vasospasm. 3) No definite additional influence of the intracerebral or intraventricular clots on the development of vasospasm. 4) High incidence of severe vasospasm with clot or thick layer in subarachnoid space.