• KSBB Journal
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• v.14 no.6
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• pp.724-730
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• 1999

Characteristics and enzyme activity comparison was made between urokinase isolated from urine and pro-urokinase separated from CHO(Chinese Hamster Ovary) cell culture broth. Both of purified urokinase and pro-urokinase resulted 54Kd single band in electrophoresis. Urokinase which was proved as a single molecule by gel filtration showed two separated 33Kd and 21Kd bands by 2-mercaptoethanol reduction. Isoelectric forcusing resulted same pl value of 8.6 for both of them. N-terminal amino acid sequence of urokinase after 159th Ile was Ile-Gly-Gly-Glu-Phe-Thr-Thr-Ile-Glu which was different from another N-terminal sequence of Ser-Asn-Glu-Leu-His-Gln-Val-Pro-Ser-Asn. Thrombolytic activities of both of them were propotional to the enzyme concentration. Urokinase showed thrombolytic activities in an short period of reaction time. Pro-urokinase, however, showed high thrombolytic activity for 2 hours or longer period of reaction time.

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.606-612
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• 2007

Fibrin clots remained in blood vessels can be one of the serious factor caused cardiovascular disease, such as ischemia, infarction and necrosis The development of an antithrombotic and thrombolysis solvent is necessary to prevent and treat these diseases. In this study, the fibirinolytic protease was prepared from the maggots of Protaetia brevitarsis using ammonium sulfate fractionation and desalting column. The optimum pH and temperature for the enzyme activity were pH 9.0 and $50^{\circ}C$, respectively. The enzyme activity was relatively stable at pH 7.0-9.0 and temperature below $60^{\circ}C$. The activity of the enzyme was strongly inhibited by phenylmethanesulfonyl fluoride. And the activity of the enzyme was inhibited by $Ca^{2+}\;and\;Zn^{2+}$, but it was not by $Mg^{2+}\;and\;Fe^{2+}$ ions. In these experimental results, we have speculated that the enzyme derived from maggots of Protaetia hrevitarsis is a serine protease with a strong fibrinolytic activity.

• Journal of Korean Neurosurgical Society
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• v.62 no.5
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• pp.502-518
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• 2019

Objective : Since less invasive endovascular treatment was introduced to South Korea in 1994, a considerable proportion of endovascular treatments have been performed by neuroradiology doctors, and endovascular treatments by vascular neurosurgeons have recently increased. However, few specific statistics are known regarding how many endovascular treatments are performed by neurosurgeons. Thus, authors compared endovascular treatments collaboratively performed by vascular neurosurgeons with all cases throughout South Korea from 2013 to 2017 to elucidate the role of neurosurgeons in the field of endovascular treatment in South Korea. Methods : The Society of Korean Endovascular Neurosurgeons (SKEN) has issued annual reports every year since 2014. These reports cover statistics on endovascular treatments collaboratively or individually performed by SKEN members from 2013 to 2017. The data was requested and collected from vascular neurosurgeons in various hospitals. The study involved 77 hospitals in its first year, and 100 in its last. National statistics on endovascular treatment from all over South Korea were obtained from the Healthcare Bigdata Hub website of the Health Insurance Review & Assessment Service based on the Electronic Data Interchange (EDI) codes (in the case of intra-arterial (IA) thrombolysis, however, statistics were based on a combination of the EDI and I63 codes, a cerebral infarction disease code) from 2013 to 2017. These two data sets were directly compared and the ratios were obtained. Results : Regionally, during the entire study period, endovascular treatments by SKEN members were most common in Gyeonggido, followed by Seoul and Busan. Among the endovascular treatments, conventional cerebral angiography was the most common, followed by cerebral aneurysmal coiling, endovascular treatments for ischemic stroke, and finally endovascular treatments for vascular malformation and tumor embolization. The number of endovascular treatments performed by SKEN members increased every year. Conclusion : The SKEN members have been responsible for the major role of endovascular treatments in South Korea for the recent 5 years. This was achieved through the perseverance of senior members who started out in the midst of hardship, the establishment of standards for the training/certification of endovascular neurosurgery, and the enthusiasm of current SKEN members who followed. To provide better treatment to patients, we will have to make further progress in SKEN.

• Journal of Korean Neurosurgical Society
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• v.62 no.5
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• pp.545-550
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• 2019

Objective : Penumbra ACE68 reperfusion catheter is a new large bore aspiration catheter used for reperfusion of large vessel occlusion. The objective of this study was to investigate the efficacy of this catheter in comparison to that of previous Penumbra catheters in patients with acute ischemic stroke related to internal carotid artery (ICA) occlusion. Methods : Data of all eligible patients who received endovascular treatment (EVT) for ICA occlusion using Penumbra aspiration catheters between January 2015 and December 2018 were retrospectively reviewed. After dividing into two groups according to use of penumbra ACE68, baseline characteristics of patients, successful recanalization rate, puncture to recanalization time, and switch to stent base technique rate were assessed. Successful recanalization was defined by a thrombolysis in cerebral infarction (TICI) score ${\geq}2b$ and favorable functional outcome was defined according to modified Rankin scale (score, 0-2). Results : ACE68 reperfusion catheter was used in 29 of 75 eligible patients (39%). The puncture to recanalization time was significantly shorter ($26{\pm}18.2$ minutes vs. $40{\pm}24.9$ minutes, p=0.011) and the rate of switch to stent-based retrieval was significantly lower (3% vs. 20%, p=0.046) in ACE68 catheter group. Moreover, although not statistically significant, the successful recanalization rate was higher (83% vs. 76%, p=0.492) in ACE68 catheter group. Favorable functional outcome was observed in 48% of patients treated with ACE68 reperfusion catheter and in 30% of patients treated using other Penumbra systems (p=0.120). Baseline Alberta Stroke Program Early CT Scores ${\geq}8$ (odds ratio [OR], 9.74; 95% confidence interval [CI], 1.72-54.99; p=0.010) and successful recanalization (OR, 10.20; 95% CI, 1.13-92.46; p=0.039) were independent predictors of favorable outcome. Conclusion : EVT using ACE68 reperfusion catheter can be considered a first-line therapy in patients with acute ICA occlusion as it can achieve rapid recanalization and reduce the frequency of conversion to stent-retrieve therapy.

• Journal of Korean Neurosurgical Society
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• v.62 no.4
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• pp.405-413
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• 2019

Objective : We evaluated efficacy of combining proximal balloon guiding catheter (antegrade flow arrest) and distal access catheter (aspiration at the site of occlusion) in thrombectomy for anterior circulation ischemic stroke. Methods : We retrospectively analyzed 116 patients who underwent mechanical thrombectomy with stent retriever. The patients were divided by the techniques adopted, the combined technique (proximal balloon guiding catheter and large bore distal access catheter) group (n=57, 49.1%) and the conventional (guiding catheter with stent retriever) technique group (n=59, 50.9%). We evaluated baseline characteristics (epidemiologic data, clinical and imaging characteristics) and procedure details (the number of retrieval attempts, procedure time), as well as angiographic (thrombolysis in cerebral infarction (TICI) score, distal thrombus migration) and clinical outcome (National Institutes of Health Stroke Scale at discharge, modified Rankin Scale [mRS] at 3 months) of them. Results : The number of retrieval attempts was lower (p=0.002) and the first-pass successful reperfusion rate was higher (56.1% vs. 28.8%; p=0.003) in the combined technique group. And the rate of final result of TICI score 3 was higher (68.4% vs. 28.8%; p<0.01) and distal thrombus migration rate was also lower (15.8% vs. 40.7%; p=0.021) in the combined technique group. Early strong neurologic improvement (improvement of National Institutes of Health Stroke Scale ${\geq}11$ or National Institutes of Health Stroke Scale ${\leq}1$ at discharge) rate (57.9% vs. 36.2%; p=0.02) and favorable clinical outcome (mRS at 3 months ${\leq}2$) rate (59.6% vs. 33.9%; p=0.005) were also better in the combined technique group. Conclusion : The combined technique needs lesser attempts, decreases distal migration, increases TICI 3 reperfusion and achieves better clinical outcomes.

• Journal of Korean Neurosurgical Society
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• v.64 no.5
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• pp.732-739
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• 2021

Objective : Early successful reperfusion is associated with favorable outcomes in acute ischemic stroke (AIS). The purpose of this study was to achieve successful recanalization by a combined mechanical thrombectomy technique, the Aspiration-Retriever Technique for Stroke (ARTS), which is composed of a flexible large lumen distal access catheter and a retrievable stent as the first-line strategy of mechanical thrombectomy. Methods : We retrospectively reviewed 62 patients with AIS who underwent mechanical thrombectomy from 2018 to 2019 at our institute by a senior neurointerventionalist. Among them, patients who were treated using the ARTS technique with the soft torqueable catheter optimized for intracranial access (SOFIA^®; MicroVention-Terumo, Tustin, CA, USA) as the first-line treatment were included. Patients who had tandem occlusions or underlying intracranial artery stenosis were excluded. The angiographic and clinical outcomes were evaluated. The angiographic outcome was analyzed by the rate of successful recanalization, defined as a Thrombolysis in Cerebral Infarction score of 2b or 3 at the end of all procedures and the rate of successfully achieving the first pass effect (FPE), defined as complete recanalization with a single pass of the device. The clinical outcomes included the National Institutes of Health Stroke Scale (NIHSS) score, modified Rankin Scale (mRS), and mortality. Results : A total of 27 patients (mean age, 59.3 years) fulfilled the inclusion criteria. The successful recanalization rate was 96% (n=26) while the FPE rate was 41% (n=11). The mean post-procedural NIHSS change was -3.0. Thirteen patients (48%) showed good clinical outcomes after thrombectomy with the ARTS technique (mRS at 90 days ≤2). Postoperative complications occurred in seven of 25 patients : hemorrhagic transformation in six patients (22%) and distal embolization in one patient (4%). Mortality was 15% (n=4). Conclusion : Although the clinical outcomes using the ARTS technique with a flexible large lumen distal access catheter performed as the frontline thrombectomy in patients with AIS were not significantly superior than those of other studies, this study showed a high rate of successful endovascular recanalization which was comparable to that of other studies. Therefore, ARTS using the SOFIA^® catheter can be considered as the first choice of treatment for AIS due to large vessel occlusion.

• Korean Journal of Radiology
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• v.21 no.5
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• pp.582-587
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• 2020

Objective: Endovascular thrombectomy (EVT) fails in approximately 20% of anterior circulation large vessel occlusion (AC-LVO). Nonetheless, the factors that affect clinical outcomes of non-recanalized AC-LVO despite EVT are less studied. The purpose of this study was to identify the factors affecting clinical outcomes in non-recanalized AC-LVO patients despite EVT. Materials and Methods: This was a retrospective analysis of clinical and imaging data from 136 consecutive patients who demonstrated recanalization failure (modified thrombolysis in cerebral ischemia [mTICI], 0-2a) despite EVT for AC-LVO. Data were collected in prospectively maintained registries at 16 stroke centers. Collateral status was categorized into good or poor based on the CT angiogram, and the mTICI was categorized as 0-1 or 2a on the final angiogram. Patients with good (modified Rankin Scale [mRS], 0-2) and poor outcomes (mRS, 3-6) were compared in multivariate analysis to evaluate the factors associated with a good outcome. Results: Thirty-five patients (25.7%) had good outcomes. The good outcome group was younger (odds ratio [OR], 0.962; 95% confidence interval [CI], 0.932-0.992; p = 0.015), had a lower incidence of hypertension (OR, 0.380; 95% CI, 0.173-0.839; p = 0.017) and distal internal carotid artery involvement (OR, 0.149; 95% CI, 0.043-0.520; p = 0.003), lower initial National Institute of Health Stroke Scale (NIHSS) (OR, 0.789; 95% CI, 0.713-0.873; p < 0.001) and good collateral status (OR, 13.818; 95% CI, 3.971-48.090; p < 0.001). In multivariate analysis, the initial NIHSS (OR, 0.760; 95% CI, 0.638-0.905; p = 0.002), good collateral status (OR, 14.130; 95% CI, 2.264-88.212; p = 0.005) and mTICI 2a recanalization (OR, 5.636; 95% CI, 1.216-26.119; p = 0.027) remained as independent factors with good outcome in non-recanalized patients. Conclusion: Baseline NIHSS score, good collateral status, and mTICI 2a recanalization remained independently associated with clinical outcome in non-recanalized patients. mTICI 2a recanalization would benefit patients with good collaterals in non-recanalized AC-LVO patients despite EVT.

• Journal of the Korean Society of Radiology
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• v.85 no.4
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• pp.746-753
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• 2024

Purpose This study aims to evaluate the incidence and management of venous ruptures after percutaneous transluminal angioplasty (PTA) for dysfunctional arteriovenous (AV) access. Materials and Methods From January 1998 to December 2015, 13506 PTA, mechanical thrombectomy, and thrombolysis procedures were performed in 6732 patients. The venous rupture rate following PTA was obtained, and access circuit primary patency (ACPP) was compared according to the etiology (PTA, thrombotic occlusion, and treatment type) of the venous rupture present. Results Venous rupture developed in 604 of the 13506 procedures. Venous ruptures were more frequent in female, AV graft cases, and in cases accompanied by thrombosis. Balloon tamponade was performed in 604 rupture cases, and stents were deployed in 119 cases where contrast extravasation and flow stasis persisted. ACPP was significantly better in the non-ruptured AV access circuits than in the ruptured group. However, AV access type and thrombosis was not associated with primary patency. In ruptured cases, ACPP is 8.4 months for prolonged balloon tamponade and 11.2 months for bare-metal stent insertion, showing statistically significant difference. Conclusion Balloon tamponade and bare-metal stent placement are effective treatment for PTA-induced venous ruptures. In particular, stent placement showed a similar ACPP to that of non-ruptured AV access circuits.

• Journal of Chest Surgery
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• v.31 no.8
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• pp.739-748
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• 1998

Background: It has been well documented that transient occlusion of the coronary artery causes myocardial ischemia and finally cell death when ischemia is sustained for more than 20 minutes. Extensive studies have revealed that ischemic myocardium cannot recover without reperfusion by adequate restoration of blood flow, however, reperfusion can cause long-lasting cardiac dysfunction and aggravation of structural damage. The author therefore attempted to examine the effect of postischemic reperfusion on myocardial ultrastructure and to determine the rationales for recanalization therapy to salvage ischemic myocardium. Materials and methods: Young Holstein-Friesian cows(130∼140 Kg body weight; n=40) of both sexes, maintained with nutritionally balanced diet and under constant conditions, were used. The left anterior descending coronary artery(LAD) was occluded by ligation with 4-0 silk snare for 20 minutes and recanalized by release of the ligation under continuous intravenous drip anesthesia with sodium pentobarbital(0.15 mg/Kg/min). Drill biopsies of the risk area (antero-lateral wall) were performed at just on reperfusion(5 minutes), 1-, 2-, 3-, 6-, 12-hours after recanalization, and at 1-hour assist(only with mechanical respiration and fluid replacement) after 12-hour recanalization. The materials were subdivided into subepicardial and subendocardial tissues. Tissue samples were examined with a transmission electron microscope (Philips EM 300) at the accelerating voltage of 60 KeV. Results: After a 20-minute ligation of the LAD, myocytes showed slight to moderate degree of ultrastructural changes including subsarcolemmal bleb formation, loss of nuclear matrix, clumping of chromatin and margination, mitochondrial destruction, and contracture of sarcomeres. However, microvascular structures were relatively well preserved. After 1-hour reperfusion, nuclear and mitochondrial matrices reappeared and intravascular plugging by polymorphonuclear leukocytes or platelets was observed. However, nucleoli and intramitochondrial granules reappeared within 3 hours of reperfusion and a large number of myocytes were recovered progressively within 6 hours of reperfusion. Recovery was apparent in the subepicardial myocytes and there were no distinct changes in the ultrastructure except narrowed lumen of the microvessels in the later period of reperfusion. Conclusions: It is likely that the ischemic myocardium could not be salvaged without adequate restoration of coronary flow and that the microvasculature is more resistant to reversible period of ischemia than subendocardium and subepicardium. Therefore, thrombolysis and/or angioplasty may be a rational method of therapy for coronarogenic myocardial ischemia. However, it may take a relatively longer period of time to recover from ischemic insult and reperfusion injury should be considered.

• Tuberculosis and Respiratory Diseases
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• v.40 no.5
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• pp.474-482
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• 1993

Background: As a physiologic plasminogen activator, tissue-type plasminogen activator (t-PA) could induce effective thrombolysis in massive pulmonary embolism, without the risk of systemic hemorrhage. However, therapeutic doses of t-PA has been associated with systemic lytic state, and fibrin selectivity may be influenced by the dosing regimen of t-PA. To investigate the effects of duration of t-PA infusion on blood coagulation system, we performed this study. Method: In a canine model of pulmonary embolism, which was induced by injection of autologous blood clots, we administered equal doses of t-PA (1 mg/kg) over 15 minutes in $t-PA_{15}$ group, over 180 minutes in $t-PA_{180}$ group, and only saline in control group. Then serial blood samplings were made to check complete blood count, prothrombin time, activated partial thromboplastin time, thrombin time, fibrin, plasminogen, ${\alpha}_2$-antiplasmin, coagulation factor V and VIII, and fibrin(ogen) degradation products. Results: 1) In all 3 groups, complete blood count showed same changes. Hemoglobin, hematocrit and platelet count decreased, but WBC count increased. 2) Prothrombin time, activated partial thromboplastin time, and thrombin time were prolonged during 15-60 minutes after t-PA administration in $t-PA_{15}$ group, and from 30 minutes through 180 minutes after administration in $t-PA_{180}$ gorup. 3) Fibrin, ${\alpha}_2$-antiplasmin, and cogulation factor V and VIII decreased in both $t-PA_{15}$ and $t-PA_{180}$ group, but returned to basal levels earlier in $t-PA_{15}$ group. 4) Fibrin(ogen) degradation products increased after pulmonary embolism in all groups, and further increased in both $t-PA_{15}$ and $t-PA_{180}$ groups after t-PA infusion. But more pronounced increment was noted in $t-PA_{180}$ gorup. Conclusion: In pulmonary embolism, the shorter (15 minutes) infusion of t-PA would have less risk of systemic hemorrhage than the longer (180 minutes) infusion when the doses is equal. And, this suggests that manipulating the duration of t-PA infusion can reduce the risk of major bleeding.