• 제목/요약/키워드: Rare events

검색결과 164건 처리시간 0.028초

A Case of Acute Pulmonary Thromboembolism after Taking Tadalafil

  • Lee, Jinwoo;Kwon, Ji Hyun;Lee, Chang-Hoon;Lee, Sang-Min;Yim, Jae-Joon;Yoo, Chuy-Gyu;Kim, Young Whan;Han, Sung Koo;Park, Young Sik
    • Tuberculosis and Respiratory Diseases
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    • 제73권4호
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    • pp.231-233
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    • 2012
  • Tadalafil is a phosphodiesterase-5 inhibitor (PDE5I), which is widely used to treat erectile dysfunction. Although PDE5Is have excellent safety profiles, and most of the side effects are mild, rare serious adverse events have been reported in association with PDE5Is. Thrombosis is one of those events, and a few previous reports have suggested the association of PDE5Is with thrombosis. We report the case of a 61-year-old male who developed pulmonary embolism combined with pulmonary infarction directly after taking tadalafil. Both the patient and the physician suspected tadalafil as the culprit drug, as the patient was in an otherwise healthy condition. However, after extensive evaluation, we noticed that factor VIII levels were elevated. Prior reports suggesting the association between thrombosis and PDEIs either lack complete information on coagulation factors, or show inconsistencies in their results. Physicians should operate caution prior to accepting the diagnosis of adverse drug reaction.

Study on Quantification Method Based on Monte Carlo Sampling for Multiunit Probabilistic Safety Assessment Models

  • Oh, Kyemin;Han, Sang Hoon;Park, Jin Hee;Lim, Ho-Gon;Yang, Joon Eon;Heo, Gyunyoung
    • Nuclear Engineering and Technology
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    • 제49권4호
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    • pp.710-720
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    • 2017
  • In Korea, many nuclear power plants operate at a single site based on geographical characteristics, but the population density near the sites is higher than that in other countries. Thus, multiunit accidents are a more important consideration than in other countries and should be addressed appropriately. Currently, there are many issues related to a multiunit probabilistic safety assessment (PSA). One of them is the quantification of a multiunit PSA model. A traditional PSA uses a Boolean manipulation of the fault tree in terms of the minimal cut set. However, such methods have some limitations when rare event approximations cannot be used effectively or a very small truncation limit should be applied to identify accident sequence combinations for a multiunit site. In particular, it is well known that seismic risk in terms of core damage frequency can be overestimated because there are many events that have a high failure probability. In this study, we propose a quantification method based on a Monte Carlo approach for a multiunit PSA model. This method can consider all possible accident sequence combinations in a multiunit site and calculate a more exact value for events that have a high failure probability. An example model for six identical units at a site was also developed and quantified to confirm the applicability of the proposed method.

Virtual-Constructive 시뮬레이션 연동을 활용한 공중전 전투 실험 (Virtual-Constructive Simulation Interoperation for Aircombat Battle Experiment)

  • 김동준;신용진;안경수;김영곤;문일철;배장원
    • 한국시뮬레이션학회논문지
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    • 제30권1호
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    • pp.139-152
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    • 2021
  • 시뮬레이션을 통하여 경험하기 어려운 사건을 가상적으로 체험할 수도 있으며, 분석을 수행할 수도 있다. 국방시뮬레이션 분야에서 이런 체험을 기반으로 Virtual 시뮬레이션이 연구 개발되고 있으며, 분석을 위하여 Constructive 시뮬레이션이 연구 개발되고 있다. 이런 시뮬레이션을 연동하여, VC(Virtual-Constructive) 시뮬레이션 환경을 구성할 수 있고, VC 시뮬레이션 환경은 전투 환경의 가상적인 경험과 교전개체의 지능적인 전술을 동시에 시험할 수 있는 환경이다. 또한, 최근의 인공지능 연구를 위해, 사람의 행동을 학습하는 이미테이션 학습 혹은 역강화학습 분야는 VC 환경에서 수집된 인간 행동 데이터를 필요로 한다. 제시된 연구는 공중전 분야에 VC 시뮬레이션 환경의 사례를 보여주며, 이를 통해 수집된 인간 행동 데이터의 특징을 분석하고 있다. 본 논문을 통하여, 공중전 분야 VC 시뮬레이션 환경이 어떻게 구축될 수 있으며, 인공지능 학습을 위하여 어떻게 활용될 수 있는지 보여준다.

Outcomes and physiologic responses associated with ketamine administration after traumatic brain injury in the United States and Canada: a retrospective analysis

  • Austin J. Peters;Saad A. Khan;Seiji Koike;Susan Rowell;Martin Schreiber
    • Journal of Trauma and Injury
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    • 제36권4호
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    • pp.354-361
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    • 2023
  • Purpose: Ketamine has historically been contraindicated in traumatic brain injury (TBI) due to concern for raising intracranial pressure. However, it is increasingly being used in TBI due to the favorable respiratory and hemodynamic properties. To date, no studies have evaluated whether ketamine administered in subjects with TBI is associated with patient survival or disability. Methods: We performed a retrospective analysis of data from the multicenter Prehospital Tranexamic Acid Use for Traumatic Brain Injury trial, comparing ketamine-exposed and ketamine-unexposed TBI subjects to determine whether an association exists between ketamine administration and mortality, as well as secondary outcome measures. Results: We analyzed 841 eligible subjects from the original study, of which 131 (15.5%) received ketamine. Ketamine-exposed subjects were younger (37.3±16.9 years vs. 42.0±18.6 years, P=0.037), had a worse initial Glasgow Coma Scale score (7±3 vs. 8±4, P=0.003), and were more likely to be intubated than ketamine-unexposed subjects (88.5% vs. 44.2%, P<0.001). Overall, there was no difference in mortality (12.2% vs. 15.5%, P=0.391) or disability measures between groups. Ketamine-exposed subjects had significantly fewer instances of elevated intracranial pressure (ICP) compared to ketamine-unexposed subjects (56.3% vs. 82.3%, P=0.048). In the very rare outcomes of cardiac events and seizure activity, seizure activity was statistically more likely in ketamine-exposed subjects (3.1% vs. 1.0%, P=0.010). In the intracranial hemorrhage subgroup, cardiac events were more likely in ketamine-exposed subjects (2.3% vs. 0.2%, P=0.025). Ketamine exposure was associated with a smaller increase in TBI protein biomarker concentrations. Conclusions: Ketamine administration was not associated with worse survival or disability despite being administered to more severely injured subjects. Ketamine exposure was associated with reduced elevations of ICP, more instances of seizure activity, and lower concentrations of TBI protein biomarkers.

대동맥류를 초래한 식도 중복 1례 (A Life-Threatening Case of Tubular Esophageal Duplication Complicated with Aneurysm of the Aorta)

  • 정연경;이경훈;정혜리;박기성;정경재;조창호
    • Clinical and Experimental Pediatrics
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    • 제48권6호
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    • pp.655-659
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    • 2005
  • 저자들은 발열과 끙끙거림을 주소로 내원한 2개월 된 소아에서 빈도가 드문 선천성 식도 중복의 감염, 파열로 인하여 농흉, 유미흉과 종격동염을 초래하고 이로 인하여 대동맥류를 초래한 1례를 경험하였기에 보고하고자 한다. 본 증례의 희귀함과 종격동염, 농흉, 대동맥류와 같은 다양한 합병증의 발생은 식도 중복을 진단하는데 있어서 어려운 점이었다.

복부 대동맥에 발생한 동맥-요관 누공의 혈관 내 치료: 증례 보고와 문헌고찰 (Endovascular Treatment for Arterioureteral Fistula of the Abdominal Aorta: A Case Report and Literature Review)

  • 이형남;이웅희
    • 대한영상의학회지
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    • 제81권4호
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    • pp.953-957
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    • 2020
  • 저자들은 복부 대동맥에 발생한 동맥-요관루를 혈관 내 접근을 통해 성공적으로 치료할 수 있었던 드문 증례를 보고하는 바이다. 동맥-요관루는 극히 드물지만, 사망률이 7~23%에 이르는 치명적인 질환이다. 저혈량쇼크와 같은 치명적 합병증을 예방하기 위해서는 조기 진단과 함께 즉각적인 치료가 필수적이다. 하지만 질환 자체가 희귀하고 민감도가 높은 검사 방법이 없기 때문에, 진단을 위해서는 높은 수준의 임상적 의심이 반드시 필요하다. 복강 내 수술, 방사선 치료 및 요관 스텐트의 장기 설치 등의 특징적인 과거력을 가진 환자에서 외상적 사건이 동맥-요관루 발생의 촉발 요인이 될 수 있다. 복부 대동맥에 발생한 동맥-요관루 환자에서도 혈관 내 인조혈관 스텐트의 삽입은 효과적인 치료 방법이다.

소낭성 동맥류 파열로 발현된 흉부 대동맥에서 기원한 미분화성 다형성 육종: 증례 보고 (Undifferentiated Pleomorphic Sarcoma of the Thoracic Aorta Presenting with Ruptured Saccular Aneurysm: A Case Report)

  • 김도우;김영환;강웅래;조준우;장재석
    • 대한영상의학회지
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    • 제81권5호
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    • pp.1204-1209
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    • 2020
  • 흉부 대동맥 미분화성 다형성 육종은 매우 드문 질환으로 색전 사례, 신혈관성 고혈압, 등 통증 등의 증상을 보일 수 있다. 특히 대동맥 벽에서 기원하여 소낭 동맥류 파열로 보고된 경우는 극히 드물며 진균성 동맥류나 관통성 죽상경화 궤양과 감별이 어렵다. 이에 저자들은 소낭성 동맥류 파열로 혈관 내 흉부 대동맥 치료를 시행한 후 종괴가 발생하여 수술적 생검으로 확진된 미분화성 다형성 육종의 전산화단층촬영과 양전자방출단층촬영 소견을 보고하고자 하며 이를 통해 정확한 진단과 적절한 치료에 도움을 주고자 한다.

Ureterosciatic hernia causing obstructive uropathy successfully managed with minimally invasive procedures

  • Kim, Yeong Uk;Cho, Jae Ho;Song, Phil Hyun
    • Journal of Yeungnam Medical Science
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    • 제37권4호
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    • pp.337-340
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    • 2020
  • Ureterosciatic hernia is extremely rare. In ureteral herniation, ureter prolapses occur through either the greater or lesser sciatic foramen. Atrophy of the piriformis muscle, hip joint diseases, and defects in the parietal pelvic fascia are predisposing factors for the development of ureterosciatic hernia. Most symptomatic patients have been treated surgically, with conservative treatment reserved only for asymptomatic patients. To the best of our knowledge, long-term follow-up outcomes after ureterosciatic hernia management are sparse. In this paper, we report the case of a 68-year-old woman who presented with colicky left abdominal pain. After computed tomography (CT) scan and anterograde pyelography, she was diagnosed ureterosciatic hernia with obstructive uropathy. We performed ureteral balloon dilatation and double-J ureteral stent placement. After this minimally invasive procedure, CT scan demonstrated that the left ureter had returned to its normal anatomical position without looping into the sciatic foramen. The patient remained asymptomatic with no adverse events 7 years after the minimally invasive procedures. This brief report describes ureterosciatic hernia successfully managed with minimally invasive procedures with long-term follow-up outcomes.

The Treatment of Left Atrial Appendage Aneurysm by a Minimally Invasive Approach

  • Kim, Young Woong;Kim, Ho Jin;Ju, Min Ho;Lee, Jae Won
    • Journal of Chest Surgery
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    • 제51권2호
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    • pp.146-148
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    • 2018
  • Left atrial appendage (LAA) aneurysm is a rare, pathologic condition that may lead to atrial tachyarrhythmia or thromboembolic events. A 49-year-old man presented with aggravated palpitation and dizziness. He suffered from refractory atrial fibrillation despite a previous history of radiofrequency catheter ablation. Echocardiography revealed a 57-mm LAA aneurysm. Surgical ablation was performed through a right mini-thoracotomy, and the LAA aneurysm was obliterated with a 50-mm AtriClip (Atricure Inc., Westchester, OH, USA). However, follow-up computed tomography showed residual communication, so the patient is still taking warfarin. We report that a minimally invasive strategy for treating LAA aneurysm can be considered, but incomplete closure may occur; thus, caution is needed.

Congenital LQT Syndromes: From Gene to Torsade de Pointes

  • Carmeliet, Edward
    • The Korean Journal of Physiology and Pharmacology
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    • 제6권1호
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    • pp.1-7
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    • 2002
  • Congenital Long QT syndrome (LQTs) is a relatively rare pathologic disorder but results frequently in sudden cardiac death. Of the six LQTs that have been clinically described, five have been worked out for their genetic and biophysical profile. Most are generated by mutations which cause a loss of function in two delayed $K^+$ currents, $i_{Ks}\;and\;i_{Kr}.$ One syndrome is generated by mutations in the $Na^+$ channel which causes essentially a gain of function in the channel. Clinically the syndromes are characterized by slowed repolarization of the cardiac ventricular action potential and the occurrence of typical arrhythmias with undulating peaks in the electrocardiogram, called Torsade de Pointes. Arrhythmias are initiated by early or delayed afterdepolarizations and continue as reentry. Triggers for cardiac events are exercise (swimming; LQT1), emotion (arousal; LQT2) and rest/sleep (LQT3). ${\beta}-blockers$ have a high efficacy in the treatment of LQT1 and LQT2. In LQT3 their use is questionable. The study of congenital LQTsyndromes is a remarkable example of how basic and clinical science converge and take profit of each other's contribution.