• Title/Summary/Keyword: coma

Search Result 466, Processing Time 0.028 seconds

Evolution of cometary dust particles to the inner solar system: Initial conditions, mutual collision and final sinks

  • Yang, Hongu;Ishiguro, Masateru
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.42 no.2
    • /
    • pp.48.3-49
    • /
    • 2017
  • Interplanetary space of the solar system contains a large number of dust particles, referred to as Interplanetary Dust Particles (IDPs) cloud complex. They are observable through meteors and zodiacal lights. The relative contribution of possible sources to the IDPs cloud complex was an controversial topic, however, recent research (Yang & Ishiguro, 2015 and references therein) suggested a dominance of cometary origin. In this study, we numerically investigated the orbital evolution of cometary dust particles, with special concerns on different evolutionary tracks and its consequences according to initial orbits, size and particle shape. The effect of dust particle density and initial size-frequency distribution (SFD) were not decisive in total cloud complex mass and mass supply rate, when these physical quantities are confined by observed zodiacal light brightness and dust particle SFD at 1 au. We noticed that, if we assume the existence of fluffy aggregates discovered in the Earth's stratosphere and the coma of 67P/Churyumov-Gerasimenko, the required mass supply rate decreases significantly. We also found out that close encounters with planets (mostly Jupiter) are the dominating factor of the orbital evolution of dust particles, as the result, the lifetime of cometary dust particles are shorter than Poynting-Robertson lifetime (around 250 thousand years). As another consequence of severe close encounters, only a small fraction of cometary dust particles can be transferred into the orbit < 1 au. This effect is significant for large size particles of ${\beta}$ < 0.01. The exceptional cases are dust particles ejected from 2P/Encke and active asteroids. Because they rarely encounter with Jupiter, most dust particles ejected from those objects are governed by Poynting-Robertson effect and well transferred into the orbits of small semimajor axis. In consideration of the above effects, we directly estimated probability of mutual collisions between dust particles and concluded that mutual collisions in the IDPs cloud complex is mostly ignorable, except for the case of large sized particles from active asteroids.

  • PDF

mTOR Signal Transduction Pathways Contribute to TN-C FNIII A1 Overexpression by Mechanical Stress in Osteosarcoma Cells

  • Zheng, Lianhe;Zhang, Dianzhong;Zhang, Yunfei;Wen, Yanhua;Wang, Yucai
    • Molecules and Cells
    • /
    • v.37 no.2
    • /
    • pp.118-125
    • /
    • 2014
  • Osteosarcoma is the most common primary malignant bone tumor with a very poor prognosis. Treating osteosarcoma remains a challenge due to its high transitivity. Tenascin-C, with large molecular weight variants including different combinations of its alternative spliced FNIII repeats, is specifically over expressed in tumor tissues. This study examined the expression of Tenascin-C FNIIIA1 in osteosarcoma tissues, and estimated the effect of mechanical stimulation on A1 expression in MG-63 cells. Through immunohistochemical analysis, we found that the A1 protein was expressed at a higher level in osteosarcoma tissues than in adjacent normal tissues. By cell migration assay, we observed that there was a significant correlation between A1 expression and MG-63 cell migration. The relation is that Tenascin-C FNIIIA1 can promote MG-63 cell migration. According to our further study into the effect of mechanical stimulation on A1 expression in MG-63 cells, the mRNA and protein levels of A1 were significantly up-regulated under mechanical stress with the mTOR molecule proving indispensable. Meanwhile, 4E-BP1 and S6K1 (downstream molecule of mTOR) are necessary for A1 normal expression in MG-63 cells whether or not mechanical stress has been encountered. We found that Tenascin-C FNIIIA1 is over-expressed in osteosar-coma tissues and can promote MG-63 cell migration. Furthermore, mechanical stress can facilitate MG-63 cell migration though facilitating A1 overexpression with the necessary molecules (mTOR, 4E-BP1 and S6K1). In con-clusion, high expression of A1 may promote the meta-stasis of osteosarcoma by facilitating MG-63 cell migration. Tenascin-C FNIIIA1 could be used as an indicator in metastatic osteosarcoma patients.

Study on the Effect of Gamigehyuldeung-tang on Gultamate Receptor, free Radical and Brain Damage in Rats (가미계혈등탕이 Glutamate receptor와 Free radical 및 뇌손상 보호에 미치는 영향)

  • An Jong suk;Kim Dong Hee;Kim Yun Sik;Lee Young Gu;Park Jong Ho;Namgung Uk;Seol In Chan
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.17 no.3
    • /
    • pp.728-737
    • /
    • 2003
  • This study was investigated to prove the effect of GMGHT on the gultamate receptor, free radical and brain damage in rats sujected to Brain Ischemia The results were as follows; 1, GMGHT showed significant inhibitory effect of GMGHT on LDH release induced by NMDA, AMPA, and kinate. 2. GMGHT showed significant inhibitory effect of GMGHT on LDH release induced by BSO and Fe/sup 2+/. 3. GMGHT decreased coma duration time in a infatal dose of KCN and showed 30% of survival rate in a fatal dose. 4. GMGHT decreased ischemic area and edema incited by the MCA blood flow block. 5. GMGHT showed improvement of forelimb and hindlimb test after MCA occulusion in neurological exemination. 6. GMGHT showed no significant change after MCA occulusion in pathological observation as normal group. These results indicate that GMGHT can be used in the brain damage sujected to Brain Ischemia. Further study will be needed about the functional mechanism and etc.

The Usefullness of Percutaneous Transarterial Embolization in Patients with Severe Multiple Traumas (다발성 손상에 의한 중증외상환자의 경피적 동맥색전술의 유용성)

  • You, In-Gyu;Lim, Cheong-Hwan
    • Journal of the Korean Society of Radiology
    • /
    • v.6 no.2
    • /
    • pp.107-114
    • /
    • 2012
  • The study was conducted in patients who had undergone angiography and arterial embolization after being diagnosed with arterial bleeding among those registered with severe trauma at the admission to the department of emergency due to accidents. In the study, comparison was done between the survived group and the nonsurvived group to investigate the usefulness and the optimal performance timing of angiography and embolization as the survival-affecting factors and treatment methods for patients. The study was performed as a retrospective analysis in 45 patients who had undergone angiography and arterial embolization among those categorized as severe trauma patients from the emergency department of H hospital located in Gyeonggi-do from July, 2006 until December, 2010. The Injury Severity Score (ISS), the Revised Trauma Score (RTS), the hematocrit were the main outcome measurements. Arterial embolization was technically successful in all cases, transcatheter arterial embolization of arterial bleeding is a useful procedure in lowering the mortality and complication in severe trauma patients. and RTS, ISS, Hematocrit were the predictable early mortality factors. So bad vital sign patients must be progressed rapidly.

Fatal Facial Mucormycosis on a Diabetic Patient: A Case Report (당뇨 환자에서 발생한 안면부 털곰팡이증에 대한 증례)

  • Choi, Jung-Hun;Kim, Young-Joon;Kwon, Ji-Eun;Kim, Hoon;Nam, Sang-Hyun;Choi, Young-Woong
    • Archives of Plastic Surgery
    • /
    • v.38 no.1
    • /
    • pp.93-95
    • /
    • 2011
  • Purpose: Mucormycosis generally occurs in patients with uncontrolled diabetes mellitus and immunocompromised conditions. It is rare, but once a patient is infected with it, it can occur as a rapidly extending, aggressive, and life-threatening rhinocerebral infection with a high mortality rate. Methods: A 70-year-old female patient had a 40 years of history of adult onset diabetes mellitus. She presented herself with severe right hemifacial pain, swelling, and weakness for 3 days and was admitted to ENT. On a facial computed tomography (CT) scan, it was found that her infection extended from her inferior temporal scalp to her submental area and involved her submandibular, masseter, prevertebral, parapharyngeal, retropharyngeal, and pharyngeal mucosal space and pansinusitis. Through endoscopic sinus surgery, mucormycosis was confirmed via histologic examination. Results: Despite empiric antibiotics and amphotericin B administration, the patient was in a septic condition and in a coma. The patient's family wanted to withdraw her life support, and the patient expired. Conclusion: Mucormycosis is very rare, but is one of the disastrous complications of uncontrolled diabetes mellitus. Suspicion of its occurrence, based on identified risk factors, and its rapid diagnosis can enhance the chance of its cure.

A Case of Congenital Intrahepatic Portosystemic Shunt Associated with VSD Detected by Antenatal Sonography and Treated with Four Coil Embolizations and Open Heart Surgery after Birth (산전 초음파로 발견되고 출생 후 4회의 코일 색전술과 심 교정술로 치료된 심실 중격 결손을 동반한 선천성 간내 문맥전신성 단락 1례)

  • Na, Ji-Youn;Kim, Eun-Sun;Kim, Sang-Duk;Kim, Ee-Kyung;Kim, Han-Suk;Choi, Jung-Hwan;Chung, Jeong-Eun;Joung, Jin-Uuk
    • Neonatal Medicine
    • /
    • v.15 no.2
    • /
    • pp.176-182
    • /
    • 2008
  • A congenital portosystemic shunt is a very rare portosystemic vascular anomaly which leads to jaundice, hypoglycemia, hyperammonemia, liver cirrhosis, hepatic coma, and pulmonary hypertension. Anatomically, portosystemic shunts are divided into intra- and extrahepatic shunts. Congenital intrahepatic portosystemic shunts are rare anomalies, and the early diagnosis is important to prevent hepatic encephalopathy and hypoglycemia. We report a case of an infant with symptoms of heart failure due to a congenital intrahepatic portosystemic shunt and a ventricular septal defect (VSD), which were treated successfully with four coil embolizations and open heart surgery for the VSD.

Two Cases of Systemic Lupus Erythematosus with Cerebrovascular Involvement (뇌 혈관계를 침범한 전신성 홍반성 루푸스 2례)

  • Kim, Bong-Jun;Lee, Eun-Young;Hong, Young-Hoon;Park, Ki-Do;Song, Young-Doo;Lee, Choong-Ki;Shim, Young-Ran
    • Journal of Yeungnam Medical Science
    • /
    • v.15 no.2
    • /
    • pp.371-380
    • /
    • 1998
  • Systemic lupus erythematosus(SLE) is an autoimmune disease which may affect many different organs and disclose various clinical manifestations. Recently central nervous system(CNS) involvement has been recognized as an increasingly significant contributor to morbidity and mortality of SLE. The clinical manifestations of CNS-lupus are highly variable and range from mild cognitive dysfunction, movement disorder, headache, psychosis to life-threatening stroke and coma. Among the neuropsychiatric disorders encountered in patients with SLE, cerebrovascular disease has been a relatively rare complication. The diagnosis and management of CNS-lupus is difficult because of the lack of useful diagnostic methods. If cerebrovascular involvement is suspected, aggressive treatment such as high dose steroid, immunosuppressive therapy, plasma exchange may be required to reduce high mortality rate. We experienced 2 cases cerebrovascular dis eases occurring in SLE patients which presented with various neuropsychiatric manifestations. They were diagnosed as CNS-lupus by neuropsychiatric symptoms, brain MRI, and BEG, and showed good response to high dose steroid pulse therapy.

  • PDF

Hyperinfection of Strongyloides stercoralis (분선충의 Hyperinfection 1례)

  • Shin, Kyeong-Cheol;Chun, Jun-Ha;Park, Chan-Weon;Lee, Choong-Ki;Lee, Hyun-Woo
    • Journal of Yeungnam Medical Science
    • /
    • v.10 no.2
    • /
    • pp.518-524
    • /
    • 1993
  • Strongylodiasis is universal in distribution but is most abundant in countries with a tropical climate. Although infestation by Strongyloides stercoralis is usually limited to the intestines, dessemination of this helminth in debilitated host can be lead to death with various clinical disorders, characterized by profound malabsorption, diarrhea, electrolyte imbalance, gram negative or opportunistic fungal sepsis, coma and death. Cell-mediated immunity contributing significantly to the control of helminthic infections, may be suppressed by carcinoma, immunosuppressive chemotherapy and use of corticosteroids. Diagnosis of Strongyloidiasis is achieved by an examination of samples of feces, duodenal aspirates and sputum of patients for Strongyloides stercoralis. Treatment of strongyloidiasis is twofold: correction of the immunosuppressive state by withdrawal of immunosuppressive drug, if possible, and vigorous treatment with thiabendazole. Testing for strongyloidiasis is especially recommanded before treating a patients should be monitored for infection by Strongyloides stercoralis and other opportunistic infection. We are reporting a case patient with Strongyloides stercoralis hyperinfection and pulmonary tuberculosis who had been used corticosteroid for persisting polyarthritis.

  • PDF

A Case of Neurotoxicity Induced by Valaciclovir in a Continuous Ambulatory Peritoneal Dialysis Patient (Valaciclovir 복용 후 중추신경계 부작용을 보였던 복막투석 환자 1예)

  • Kim, Joon-Seok;Yang, Jee Eun;Lee, Bo Young;Lee, Seohyun;Park, Hee Jung;Lee, Sunpyo;Lee, Sang Koo
    • Journal of Yeungnam Medical Science
    • /
    • v.29 no.2
    • /
    • pp.121-124
    • /
    • 2012
  • Valaciclovir is metabolized to acyclovir after ingestion and thereafter exerts its antiviral activity. Because of its superior pharmacokinetic profile, it has quickly replaced acyclovir in the treatment of herpesvirus infection. Neurotoxicity caused by valaciclovir has been reported, however, among patients with pre-existing impaired renal function. This paper reports a case of neurotoxicity of valaciclovir in a patient with end-stage renal disease who was undergoing continuous ambulatory peritoneal dialysis (CAPD). A 67-year-old female on CAPD took 500 mg of valaciclovir twice for herpes zoster. After she took her second dose orally, she developed confusion and disorientation, along with involuntary movements. Her mental confusion progressed to a coma. Discontinuation of valaciclovir showed no rapid improvement. There- fore, hemodialysis was started. After two sessions of hemodialysis, the patient became alert; and after four sessions of hemodialysis, her neurological abnormalities were completely reversed. In conclusion, valaciclovir can induce life-threatening neurotoxicity, especially in CAPD patients, even with appropriate dose reduction, which can be effectively managed by hemodialysis.

  • PDF

Risk Factors for Aspiration Pneumonia in Acute Benzodiazepine Overdose (벤조디아제핀 급성 중독에서 발생하는 흡인성 폐렴 위험 인자)

  • Chung, Won Sik;Cha, Kyung Man;Kim, Hyung Min;Jeong, Won Jung;So, Byung Hak
    • Journal of The Korean Society of Clinical Toxicology
    • /
    • v.14 no.1
    • /
    • pp.26-32
    • /
    • 2016
  • Purpose: Aspiration pneumonia is an important complication of drug intoxication with decreased mental status. The purpose of the study is to investigate the risk factors of aspiration pneumonia in the patients of benzodiazepine overdose with or without co-ingestion of other drugs. Methods: A retrospective chart review of patients who visited the emergency department between January 2012 and December 2014 was conducted. Demographic data, time from ingestion to visit, initial vital signs, symptoms, mental status, medical history, laboratory results, chest radiological findings and co-ingested medications were recorded. Multiple logistic analyses were performed to verify the association between variables and the development of aspiration pneumonia. Results: A total of 249 patients presented to the emergency department with benzodiazepine overdose. Aspiration pneumonia had developed in 24 patients (9.6%). Univariate analysis revealed time from ingestion to visit was longer, Glasgow coma scale score was lower, hypoxia was presented, leukocytosis was shown, types of ingested drugs was high, less activated charcoal was applied and tricyclic antidepressants was taken in patients that developed aspiration pneumonia. Time from ingestion to visit (odds ratio (OR) 1.121, 95% confidence interval (CI), 1.057-1.189, p=0.000), GCS score (OR 0.724. 95% CI, 0.624-0.839, p=0.000), oxygen saturation (OR 0.895, 95% CI, 0.835-0.959, p=0.002), and co-ingestion of TCA (OR 4.595, 95% CI, 1.169-18.063, p=0.029) were identified as risk factors of morbidity of aspiration pneumonia upon multiple logistic regression analysis. Conclusion: Time from ingestion to visit, low GCS score, low oxygen saturation and co-ingestion of TCA were risk factors of the development of aspiration pneumonia in benzodiazepine overdose patients.

  • PDF