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The Antioxidant Effect of Vitamin C and Deferoxamine on Paraquat-induced Cytotoxicity in Cultured Lymphocytes (배양림프구에서 Paraquat의 세포독성에 대한 Vitamin C와 Deferoxamine의 항산화 효과)

  • Eo Eun-Kyung;Kim Kyung-Hee
    • Journal of The Korean Society of Clinical Toxicology
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    • v.4 no.1
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    • pp.7-16
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    • 2006
  • Purpose: As basic information of antioxidant treatments for the patient with paraquat intoxication, in human peripheral lymphocytes, the cytotoxicity of paraquat was measured, and to evaluate the antioxidant effect of vitamin C and deferoxamine against this cytotoxicity, malondialdehyde (MDA), superoxide dismutase (SOD) activity and total antioxidant status (TAS) were measured. Methods: From 10 healthy adults, after obtaining a consent, 20ml peripheral blood was collected. Experimental groups were divided to (1) control group, the group treated with an identical amount of saline, (2) P group: the group treated with paraquat only, (3) PV group: the group treated with paraquat followed by vitamin C 30 minutes later, (4) PD group: the group treated with paraquat followed by deferoxamine 30 minutes later, (5) PVD group: the group treated with paraquat followed by vitamin C 30 minutes later and subsequently deferoxamine one hour later, and (6) PDV group: the group treated with paraquat followed by deferoxamine 30 minutes later and subsequently vitamin C 1 hour later, and thus to total 6 groups. In each group, 10 samples of peripheral blood was assigned and $100{\mu}M\;paraquat,\;100{\mu}M$ vitamin C, and $100{\mu}M$ deferoxamine were used as reagent. Lymphocytes were isolated, cultured, and cytotoxicity was measured by the Microculture Tetrazolium method (MTT assay), MDA and SOD activity, and TAS concentration were measured. Results: In regard to the cytotoxicity measured in each group, their cytotoxicity was decreased in the group treated with antioxidants, in comparison with the group treated with paraquat only. In the cases that the order of the treatment of these two antioxidants was altered, viability in the PDV group $(1.077{\pm}0.121)$ was increased more that the PVD group $(0.888{\pm}0.152)$ statistically significantly (p=0.018). Concerning the amount of MDA, in comparison with the P group $(6.78{\pm}0.93{\mu}mol/L)$, after the treatment of each antioxidant, the concentration of MDA was decreased statistically significantly (p<0.05). In the group treated with two antioxidants together, in comparison with the group treated only with one antioxidant, the amount of MDA was increased statistically significantly $(PV:\;3.96{\pm}0.98{\mu}mol/L,\;PD:\;4.92{\pm}1.50{\mu}mol/L,\;PVD:\;3.22{\pm}0.83{\mu}mol/L,\;and\;PDV:\;3.42{\pm}0.95{\mu}mol/L,\;p=0.007)$. The concentration of SOD measured in the blood in each group after the administration of paraquat, in comparison with the control group, a pattern of the elevation of SOD activity and subsequent decrease was detected, however, it was not statistically significant. In the comparison of the groups treated with antioxidants, in comparison with the P group $(1419.9{\pm}265.9{\mu}mol/L)$, SOD activity was decreased statistically significantly in only the PDV group $(1176.4{\pm}238.9{\mu}mol/L)$ (p=0.017). In regard to TAS measured in each group, in comparison with the P group $(0.87{\pm}0.05{\mu}mol/L)$, in all groups treated with the antioxidants, the PV group was $1.00{\pm}0.03{\mu}mol/L$ (p=0.005), the PD group was $9.01{\pm}0.24{\mu}mol/L$ was $4.64{\pm}3.98{\mu}mol/L$ (P=0.005), and the PDV group was $9.41{\pm}0.27{\mu}mol/La$ (p=0.005), and thus total antioxidant activity was increased statistically significantly In a multiple comparison test, the PDV group showed the highest total antioxidant activity (p<0.0001). Conclusion: The result of the assessment of the antioxidant effect of vitamin C and deferoxamine on paraquat-induced cytotoxicity showed that in regard to cytotoxicity, SOD activity and TAS measurement, the best result was observed in the PDV group. Therefore, it was found that vitamin C and deferoxamine were effective antioxidants for the paraquat-induced cytotoxicity, and it suggests that the administration of deferoxamine followed by vitamin C may improve their antioxidant effect more.

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A Study on Contents of Sulfites in Fruits and Vegetables (과실류 및 채소류 중 아황산염류 함유량 조사연구)

  • Mun Tae-Jung;Kim Ki-Jun;Park Seong-Min;Kim Hyeon-Jeong;Park Jong-Jin;Kang Heun-Kag;Jung Sang-Mi;Lee Mi-Yeong;Goo Ja-Hang;Im Ji-Soon
    • Food Science and Preservation
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    • v.13 no.4
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    • pp.432-437
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    • 2006
  • To compare the content of natural existence with artificial addition experimental subject of 152 cases(25 kinds) were classified by two category of 42 fresh samples(14 kinds) and 110 processed samples(23 kinds). The content of sulfur dioxide were determined by Monnier-Williams's modified method. In mean content of 42 non-processed samples studied the range of contents was between 0.00 and 9.46 mg/kg. Radish contained the highest amount of sulfur dioxide(8.97 mg/kg), followed by onion(8.04 mg/kg). In mean content of 110 processed samples studied, the range of content was between 0.00 and 1,828.59 mg/kg. Gourd contained the highest amount of sulfur dioxide(1,064.61 mg/kg), followed by apricot(869.62 mg/kg), dried persimmon(64.11 mg/kg), dried radish(29.00 mg/kg), dried pumpkin(17.63 mg/kg), and those were lowe. than criteria. To supply safe food for the citizens, the quantitative level is required to be reinforced to supply safe foot continuously.

Object-based Building Change Detection Using Azimuth and Elevation Angles of Sun and Platform in the Multi-sensor Images (태양과 플랫폼의 방위각 및 고도각을 이용한 이종 센서 영상에서의 객체기반 건물 변화탐지)

  • Jung, Sejung;Park, Jueon;Lee, Won Hee;Han, Youkyung
    • Korean Journal of Remote Sensing
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    • v.36 no.5_2
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    • pp.989-1006
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    • 2020
  • Building change monitoring based on building detection is one of the most important fields in terms of monitoring artificial structures using high-resolution multi-temporal images such as CAS500-1 and 2, which are scheduled to be launched. However, not only the various shapes and sizes of buildings located on the surface of the Earth, but also the shadows or trees around them make it difficult to detect the buildings accurately. Also, a large number of misdetection are caused by relief displacement according to the azimuth and elevation angles of the platform. In this study, object-based building detection was performed using the azimuth angle of the Sun and the corresponding main direction of shadows to improve the results of building change detection. After that, the platform's azimuth and elevation angles were used to detect changed buildings. The object-based segmentation was performed on a high-resolution imagery, and then shadow objects were classified through the shadow intensity, and feature information such as rectangular fit, Gray-Level Co-occurrence Matrix (GLCM) homogeneity and area of each object were calculated for building candidate detection. Then, the final buildings were detected using the direction and distance relationship between the center of building candidate object and its shadow according to the azimuth angle of the Sun. A total of three methods were proposed for the building change detection between building objects detected in each image: simple overlay between objects, comparison of the object sizes according to the elevation angle of the platform, and consideration of direction between objects according to the azimuth angle of the platform. In this study, residential area was selected as study area using high-resolution imagery acquired from KOMPSAT-3 and Unmanned Aerial Vehicle (UAV). Experimental results have shown that F1-scores of building detection results detected using feature information were 0.488 and 0.696 respectively in KOMPSAT-3 image and UAV image, whereas F1-scores of building detection results considering shadows were 0.876 and 0.867, respectively, indicating that the accuracy of building detection method considering shadows is higher. Also among the three proposed building change detection methods, the F1-score of the consideration of direction between objects according to the azimuth angles was the highest at 0.891.

The Changes of Cerebral Metabolic and Hemodynamic Parameters, Brain Histology, and Serum Levels of Neuron-Specific Enolase During Retrograde Cerebral Perfusion Under Pofound Hypothermic total Circulatory Arrest in Pigs (돼지에서 초저체온 순환정지 하의 역행성 뇌관류시 뇌대사, 혈류역학 지표, 뇌조직 소견 및 혈청 내 neuron-specific enolase의 변화)

  • Kim, Kyung-Hwan;Ahn, Hyuk
    • Journal of Chest Surgery
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    • v.33 no.6
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    • pp.445-468
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    • 2000
  • Background: Retrograde cerebral perfusion(RCP) is currently used for brain protection during aorta surgery, however, for the safety of it, various data published so far are insufficient. We performed RCP using pig and investiaged various parameters of cerebral metabolism and brain injury after RCP under deep hypothermia. Material and Method: We used two experimental groups: in group I(7 pigs, 20 kg), we performed RCP for 120 minutes and in group II (5 pigs, 20 kg), we did it for 90 minutes. Nasopharyngeal temperature, jugular venous oxygen saturation, electroencephalogram were continuously monitored, and we checked the parameters of cerebral metabolism, histological changes and serum levels of neuron-specific enolose(NSE) and lactic dehydrogenase(LDH). Central venous pressure during RCP was mainained in the range of 25 to 30 mmHg. Result: Perfusion flow rates(ml/min) during RCP were 130$\pm$57.7(30 minutes), 108.6$\pm$55.2(60 minutes), 107.1$\pm$58.8(90 minutes), 98.6$\pm$58.7(120 minutes) in group I and 72$\pm$11.0(30 minutes), 72$\pm$11.0(60 minutes), 74$\pm$11.4(90 minutes) in group II. The ratios of drain flow to perfusion flow were 0.18(30 minutes), 0.19(60 minutes), 0.17(90 minutes), 0.16(120 minutes) in group I and 0.21, 0.20, 0.17 in group II. Oxygen consumptions(ml/min) during RCP were 1.80$\pm$1.37(30 minutes), 1.72$\pm$1.23(60 minutes), 1.38$\pm$0.82(90 minutes), 1.18$\pm$0.67(120 minutes) in group I and 1.56$\pm$0.28(30 minutes), 1.25$\pm$0.28(60 minutes), 1.13$\pm$0.26(90 minutes). We could observe an decreasing tendency of oxygen consumption after 90 minutes of RCP in group I. Cerebrovascular resistance(dynes.sec.cm-5) during RCP in group I incrased from 71370.9$\pm$369145.5 to 83920.9$\pm$49949.0 after the time frame of 90 minutes(p<0.05). Lactate(mg/min) appeared after 30 minutes of RCP and the levels were 0.15$\pm$0.07(30 minutes), 0.18$\pm$0.10(60 minutes), 0.19$\pm$0.19(90 minutes), 0.18$\pm$0.10(120 minutes) in group I and 0.13$\pm$0.09(30 minutes), 0.19$\pm$0.03(60 minutes), 0.29$\pm$0.11(90 minutes) in group II. Glucose utilization, exudation of carbon dioxide, differences of cerebral tissue acidosis between perfusion blood and drain blood were maintained constantly during RCP. Oxygen saturation levels(%) in drain blood during RCP were 22.9$\pm$4.4(30 minutes), 19.2$\pm$4.5(60 minutes), 17.7$\pm$2.8(90 minutes), 14.9$\pm$2.8(120 minutes) in group I and 21.3$\pm$8.6(30 minutes), 20.8$\pm$17.6(60 minutes), 21.1$\pm$12.1(90 minutes) in group II. There were no significant changes in cerebral metabolic parameters between two groups. Differences in serum levels of NSE and LDH between perfusion blood and drain blood during RCP showed no statistical significance. Serum levels of NSE and LDH after resuming of cardipulmonary bypass decreased to the level before RCP. Brain water contents were 0.73$\pm$0.03 in group I and 0.69$\pm$0.06 in group II and were higher than those of the controls(p<0.05). The light microscopic findings of cerebral neocortex, basal ganglia, hippocampus(CA1 region) and cerebellum showed no evidence of cerebral injury in two groups and there were no different electron microscopy in both groups(neocortex, basal ganglia and hippocampus), but they were thought to be reversible findings. Conclusion: Although we did not proceed this study after survival of pigs, we could perform the RCP successfully for 120 minutes with minimal cerebral metabolism and no evidence of irreversible brain damage. The results of NSE and LDH during and after RCP should be reevaluated with survival data.

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Histological Comparison of Vascular Grafts in a Pig to Goat Xenotransplantation Model (돼지-염소 이종이식모델에서 냉동 및 무세포화 혈관이식편의 조직학적 비교분석)

  • Yang Ji-Hyuk;Sung Ki-Ick;Kim Won-Geon
    • Journal of Chest Surgery
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    • v.39 no.6 s.263
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    • pp.427-433
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    • 2006
  • Background: Current vascular prostheses are considered still inadequate for reconstruction of small-diameter vessels. To evaluate the potential use of xenograft vessels as small diameter arterial grafts, we implanted porcine vessels in goats. The grafts were treated with two different processes, freezing and acellularization, before implantation, and gross inspection as well as microscopic examination followed after a predetermined period. Material and Method: Bilateral porcine carotid arteries were harvested and immediately stored at $-70^{\circ}C$ within tissue preservation solution. One of them was designated as frozen xenograft vessel. The other one was put on acellularization process using NaCl-SDS solution and stored frozen until further use. Grafts were implanted in the place of carotid arteries of the same goat. The grafts have remained implanted for 1, 3, and 6 months in three animals, respectively. Periodic ultrasonographic examinations were performed during the observation period. After explantation, the grafts were analyzed grossly and histologically under light microscope. Result: All animals survived the experimental procedure without problems. Ultrasonographic examinations showed excellent patency of all the grafts during the observation period. Gross examination revealed nonthrombotic, patent lumens with smooth surfaces. Microscopic examinations of the explanted grafts showed cellular reconstruction at the 6-month stage in both grafts. Although more inflammatory responses were observed in the early phase of frozen xenografts, there was no evidence of significant rejection. Conclusion: These findings suggest that porcine xenograft vessels, regardless of pre-implantation processes of acelluarization or freezing, can be acceptably implanted in goats, although short duration of observation in a small number of animals may limit this study.

Role of Group II Phospholipase $A_2$ in the Pulmonary Oxidative Stress of the Acute Lung Injury Induced by Gut Ischemia-Reperfusion (장의 허혈-재관류로 유도된 급성 폐손상에서 산화성 스트레스에 관여하는 group II phospholipase $A_2$의 역할)

  • Jheon, Sang-Hoon;Kim, Keun;Lee, Sang-Cheol;Kim, Seong-Eun;Lee, Young-Man;Lee, Jong-Tae
    • Journal of Chest Surgery
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    • v.35 no.7
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    • pp.501-510
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    • 2002
  • Background: The various pathogeneses of acute respiratory distress syndrome have been suggested but not established yet. In the present study, the role of group II phospholipase $A_2$($PLA_2$) in the pathogenesis of gut ischemia-reperfusion(I/R) induced acute lung injury (ALI), especially in the pulmonary oxidative stress with infiltration of neutrophils was investigated. Material and Method: To induce ALI, reperfusion of mesentery was done for 120 min after clamping of superior mesenteric artery for 60 min in Sprague-Dawley rats that weighed about 300g. To exmaine the role of group II $PLA_2$ in ALI, especially endothelial injury associated with the action of neutrophils, lung myeloperoxidase activity, lung leak index, bronchoalveolar lavage fluid protein were measured, and pulmonary $PLA_2$ activity changes in gut I/R were also measured. The role of group II $PLA_2$in the neutrophilic generation of free radicals was assessed by inhibiting group II $PLA_2$ with rutin, manoalide and scalaradial. Furthermore, to verify the oxidative stress in the lung, histologic and free radical detecting cytochemical electron microscopy were done. Result: After reperfusion, ALI was developed with accumulation of neutrophils in the lung, which was confirmed by the increase of myeloperoxidase activity, lung leak index and bronchoalveolar lavage protein (p<0.001). The pulmonary and intestinal group II $PLA_2$ activities significantly increased after gut I/R which were reversed by rutin(p<0.001). In vitro, cytochrome-c reduction assay denoted the inhibitory effects of rutin, scalaradial and manoalide on the production of free radicals from isolated human neutrophils. Histologically, neutrophilic accumulation and pericapillary edema in the lung after gut I/R was detected by light microscopy which was suppressed by rutin. In $CeCl_3$ cytochemical electron microscopy, the increased production of hydrogen peroxide in the lung after gut I/R was confirmed and also the production of hydrogen peroxide was decreased by rutin. Conclusion: On the basis of these experimental results, the inhibition of group II $PLA_2$ seemed to mitigate gut I/R-induced ALI by suppressing the production of free radicals from the infiltrated neutrophils. Collectively, group II $PLA_2$ seems to play a crucial role in gut I/R-induced ALI by neutrophilic oxidative stress.

Bilateral Sequential Lung Transplantation in Dogs (황견에서 동종 순차적 양측 폐이식 수술에 관한 연구)

  • 이두연;김해균;문동석;윤용한;홍윤주;이성수
    • Journal of Chest Surgery
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    • v.31 no.2
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    • pp.108-112
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    • 1998
  • Experimental trials of unilateral lung transplantation in dogs have been attempted and satisfactory results were obtained without any noticeable difficulty in surgical techniques. Fourteen dogs with the body weight of around 25 kg were anesthesized by 20~30 mg/kg of intravenous Entobar,; one was sacrificed to make available blood for use during transplantation for the recipient dog. A mid-sternotomy incision was performed and 20 mg/kg of Prostaglandin E1 was infused through the pulmonary artery and Euro-Collin's(E-C) preservation solution, cooled down to 4$^{\circ}C$, was perfused at the rate of 70cc/kg by a pressure of 30 cmH2O. The heart-lung block was then resected out and promptly immersed in the prepared preservation solution at 4$^{\circ}C$. One lung preserved in the EC solution at 4$^{\circ}C$ was anastomosed to the recipient dog in the order of the pulmonary vein, bronchus then pulmomary artery and the thoracotomy incision was closed after the bleeding control and tube thoracostomy. Then the pneumonectomy in the opposite side was perfomed in the same manner and the tailored lung was transplanted in the order of the pulmonary vein, bronchus, then pulmonary artery. We conclude that in the bilateral sequential lung transplantation, the right lung transplantation should precede to better expose the operative field and to prevent reperfusion injury; also, the cardiopulmonary bypass should be consider for certain appropriate cases.

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The Effect of Matrix Metalloproteinase Inhibitor for Left Ventricular Remodeling after Myocardial Infarction in a Rabbit Model (토끼에서 Myocardial Infarction 후 Left Ventricular Remodeling에 대한 Matrix Metalloproteinase의 차단 효과)

  • Kim, Soo-Hyun;Jung, Tae-Eun;Hong, Geu-Ru;Han, Sung-Sae
    • Journal of Chest Surgery
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    • v.40 no.5 s.274
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    • pp.329-340
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    • 2007
  • Background: Matrix Metalloproteinase (MMP) inhibition has emerged as a potential therapeutic strategy for the left ventricular dilatation that occurs after myocardial infarction. This study is designed to evaluate which treatment is better for attenuating the left ventricular remodeling via MMP inhibition 1) during the early, short highly MMP producing period of the initial phase or 2) during most of the period of the initial phase after myocardial infarction. Material and Method: Myocardial infarction was induced by ligation of the left anterior descending coronary artery in rabbits. The experimental group was divided into 3 groups. The myocardial infarction only (MI only) group consisted of 7 cases. The MMP inhibitor administered for 5 days after MI (MMPI 50) group had 6 cases, and these rabbits were given MMP inhibitor for 5 days after myocardial infarction, beginning with the postoperative first day. MMP inhibitor administered for 9 days (MMPI 90) group consisted of 5 cases and these rabbits were given MMPI for 9 days the same manner as above. CG2300 was used as a selective MMPI; this is a potent MMP-2 and -9 inhibitor Two-D echocardiograms were performed on all the groups at the time of preoperative period, the post-operative 1st week, the postoperative 20 week and the postoperative 30 week, and we measured the end-diastolic dimension (EDD), the end-systolic dimension (ESD), and the ejection fraction (EF). Result: The echocardiograms generally showed postoperative left ventricular dilatation in the MI only group. The EDD was increased significantly higher in the postoperative 1 week compared to the preoperative value (p<0.05). The ESD was also increased significantly higher in the postoperative 1st week, the postoperative 20 week and the postoperative 30 week compared to the preoperative value (p<0.05). Left ventricular dilatation was noted to be less In the MMPI 9d group than in the MI only and MMPI 5d groups. In the MMPI 9d group, there was no significant change of EF postoperatively compared to the preoperative period. MMP-2 and MMP-9 were measured from the infarcted myocardial tissue at post-MI 4 weeks by performing western blotting and zymography. The changes the of protein expression and activity of MMP-2 and MMP-9 were not significant in the three MI groups and the normal heart group. Histopathologic examination revealed severe collagen deposition in the MI only group. Collagen accumulation was reduced in both the MMPI groups. The MMPI 9d group revealed an increased number of capillaries. Conclusion: Left ventricular dilatation developed rapidly after, MI from ligation of the coronary artery and MMPI attenuated the ventricular dilatation. The effect of MMPI seemed to have better a result from its usage during most of the period of the initial phase after myocardial infarction. This suggested that increased neovascularization by MMPI may also contribute to attenuation of the left ventricular remodeling.

Effects of Anabolic Steroids of Pork on Proliferation and Differentiation of Myogenic Satellite Cell (돼지 고기의 아나볼릭 스테로이드가 Myogenic Satellite Cell의 증식과 분화에 미치는 영향)

  • Lee, Dong-Mok;Lee, Ki-Ho;Cheon, Yong-Pil;Chun, Tae-Hoon;Choi, In-Ho
    • Food Science of Animal Resources
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    • v.30 no.5
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    • pp.842-850
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    • 2010
  • Sex steroids are known to be involved in skeletal muscle development (anabolic effect) and are frequently used in medicines. It has been known that pork contains a variety of steroids that are mainly synthesized in the gonads (testis and ovary). Thus, the present study was conducted to evaluate the effects of anabolic steroids of pork on the proliferation and differentiation of myogenic satellite cells (MSC). Three different methods (M1, M2, and M3) were developed for the isolation and purification of steroids from porcine tissues. Among three extraction methods that we developed, M3 was the best method with respect to the quantities of steroids and the induction of MSC proliferation. Hormonal analysis showed that the steroid hormone levels were the highest in muscle and fat of intact male than those of castrated males and females. In addition, the highest serum levels of nandrolone and testosterone were detected in intact males, whereas estrone and $17{\beta}$-estradiol levels were similar in the entire experimental serum samples. Expression of androgen receptor (AR), myoD, desmin, and myogenin in bovine muscle cells were significantly up-regulated by the treatment of steroid extracts. The highest increas of myogenin and AR mRNA abundance were observed in the MSCs treated with M3 extract (p<0.001). Altogether, the present research showed the positive effect of steroids on MSC proliferation and differentiation in vitro. These results would certainly imply a beneficial effect of pork consumption on human muscle development.

Effects of the Dosing Regimen of Tissue-type Plasminogen Activator on Blood Coagulation System in Experimental Pulmonary Embolism (실험적 폐색전증에서 조직형플라스미노겐활성체의 투여방법이 혈액응고기전에 미치는 영향)

  • Chung, Hee-Soon;Kim, Ho-Joong;Shim, Young-Soo
    • 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.

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