WorldWideScience

Sample records for prominent porto-systemic collateral

  1. Prominent porto-systemic collateral pathways in patients with portal hypertension: demonstration by gadolinium-enhanced magnetic resonance angiography

    International Nuclear Information System (INIS)

    Caldana, Rogerio Pedreschi; Bezerra, Alexandre Araujo Sergio; Cecin, Alexnadre Oliveira; Souza, Luis Ronan Marques Ferreira de; Goldman, Susan Menasce; D'Ippolito, Giuseppe; Szejnfeld, Jacob

    2003-01-01

    To demonstrate the usefulness of gadolinium-enhanced magnetic resonance angiography in the evaluation of prominent porto-systemic collateral pathways. We reviewed the images from 40 patients with portal hypertension studied with gadolinium-enhanced magnetic resonance angiography and selected illustrative cases of prominent porto-systemic collateral pathways. The scans were performed using high field equipment (1.5 Tesla) and a 3 D volume technique. Image were obtained after intravenous injection of paramagnetic contrast media using a power injector. Magnetic resonance angiography demonstrated with precision the porto-systemic collateral pathways, particularly when investigating extensive territories or large vessels. The cases presented show the potential of this method in the investigation of patients with portal hypertension. Gadolinium-enhanced magnetic resonance angiography is a useful method for the evaluation of patients with portal hypertension and prominent collateral pathways. (author)

  2. Prominent porto-systemic collateral pathways in patients with portal hypertension: demonstration by gadolinium-enhanced magnetic resonance angiography; Vias colaterais porto-sistemicas exuberantes em portadores de hipertensao portal: demonstracao pela angiografia por ressonancia magnetica com gadolinio

    Energy Technology Data Exchange (ETDEWEB)

    Caldana, Rogerio Pedreschi; Bezerra, Alexandre Araujo Sergio; Cecin, Alexnadre Oliveira; Souza, Luis Ronan Marques Ferreira de; Goldman, Susan Menasce; D' Ippolito, Giuseppe; Szejnfeld, Jacob [Universidade Federal de Sao Paulo (UNIFESP/EPM), Sao Paulo, SP (Brazil). Dept. de Diagnostico por Imagem]. E-mail: rogercal@uol.com.br

    2003-03-01

    To demonstrate the usefulness of gadolinium-enhanced magnetic resonance angiography in the evaluation of prominent porto-systemic collateral pathways. We reviewed the images from 40 patients with portal hypertension studied with gadolinium-enhanced magnetic resonance angiography and selected illustrative cases of prominent porto-systemic collateral pathways. The scans were performed using high field equipment (1.5 Tesla) and a 3 D volume technique. Image were obtained after intravenous injection of paramagnetic contrast media using a power injector. Magnetic resonance angiography demonstrated with precision the porto-systemic collateral pathways, particularly when investigating extensive territories or large vessels. The cases presented show the potential of this method in the investigation of patients with portal hypertension. Gadolinium-enhanced magnetic resonance angiography is a useful method for the evaluation of patients with portal hypertension and prominent collateral pathways. (author)

  3. Porto-systemic collaterals in cirrhosis of the liver. Selective percutaneous transhepatic catheterization of the portal venous system in portal hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Hoevels, J; Lunderquist, A; Tylen, U; Simert, G [Lund Univ. (Sweden)

    1979-01-01

    In 93 patients with cirrhosis of the liver and portal venous hypertension the main tributaries of the portal vein were examined by percutaneous transhepatic catheterization. The appearance and degree of porto-systemic collaterals were analysed. Esophageal varices were demonstrated in 82 patients. No correlation was found between the portal venous pressure and the extent of porto-systemic communications.

  4. Leptomeningeal collateralization in acute ischemic stroke: Impact on prominent cortical veins in susceptibility-weighted imaging

    International Nuclear Information System (INIS)

    Verma, Rajeev K.; Hsieh, Kety; Gratz, Pascal P.; Schankath, Adrian C.; Mordasini, Pasquale; Zubler, Christoph; Kellner-Weldon, Frauke; Jung, Simon; Schroth, Gerhard; Gralla, Jan; El-Koussy, Marwan

    2014-01-01

    Background: The extent of hypoperfusion is an important prognostic factor in acute ischemic stroke. Previous studies have postulated that the extent of prominent cortical veins (PCV) on susceptibility-weighted imaging (SWI) reflects the extent of hypoperfusion. Our aim was to investigate, whether there is an association between PCV and the grade of leptomeningeal arterial collateralization in acute ischemic stroke. In addition, we analyzed the correlation between SWI and perfusion-MRI findings. Methods: 33 patients with acute ischemic stroke due to a thromboembolic M1-segment occlusion underwent MRI followed by digital subtraction angiography (DSA) and were subdivided into two groups with very good to good and moderate to no leptomeningeal collaterals according to the DSA. The extent of PCV on SWI, diffusion restriction (DR) on diffusion-weighted imaging (DWI) and prolonged mean transit time (MTT) on perfusion-imaging were graded according to the Alberta Stroke Program Early CT Score (ASPECTS). The National Institutes of Health Stroke Scale (NIHSS) scores at admission and the time between symptom onset and MRI were documented. Results: 20 patients showed very good to good and 13 patients poor to no collateralization. PCV-ASPECTS was significantly higher for cases with good leptomeningeal collaterals versus those with poor leptomeningeal collaterals (mean 4.1 versus 2.69; p = 0.039). MTT-ASPECTS was significantly lower than PCV-ASPECTS in all 33 patients (mean 1.0 versus 3.5; p < 0.00). Conclusions: In our small study the grade of leptomeningeal collateralization correlates with the extent of PCV in SWI in acute ischemic stroke, due to the deoxyhemoglobin to oxyhemoglobin ratio. Consequently, extensive PCV correlate with poor leptomeningeal collateralization while less pronounced PCV correlate with good leptomeningeal collateralization. Further SWI is a very helpful tool in detecting tissue at risk but cannot replace PWI since MTT detects significantly more ill

  5. Incidentally diagnosed Takayasu arteritis on thyroid ultrasonography showing prominent collateral vessels of thyroidal arteries and common carotid artery occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Se Jin; Kim, Eun Kyung [Dept. of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2014-10-15

    We report a case of middle-aged woman incidentally diagnosed with Takayasu arteritis during the ultrasonography of a thyroid gland nodule. Prominent collaterals of the thyroidal arteries and a thin common carotid artery with mural thickening and deficient intraluminal flow signals were initially depicted on the ultrasonography with color Doppler. Subsequent magnetic resonance angiography and computed tomography aortography confirmed the diagnosis with the imaging features of a bilateral long segment common carotid artery occlusion and segmental stenosis of the left subclavian artery in addition to the suggestive physical findings.

  6. Frequency of helicobacter pylori antibodies in porto-systemic encephalopathy,

    International Nuclear Information System (INIS)

    Sethar, G.H.; Ahmed, R.; Afsar, S.; Zuberi, B.F.

    2004-01-01

    Objective: To study the frequency of Helicobacter pylori antibodies in patients presenting with porto-systemic encephalopathy due to liver disease. Patients and Methods: During the study period, seventy-six patients of porto-systemic encephalopathy due to liver diseases was selected. These subjects were evaluated for hepatic encephalopathy grade, modified Child-Pugh classification and were managed according to the standard practices. These patients were evaluated for Helicobacter (H. pylori) antibody status by ELlSA (Abbott Laboratories) method. Results: Out of 76 patients studied and tested for H. pylori antibodies, 48(63.2%) were males and 28(36.8%) were females with age ranging between 17 and 85 years. Out of 76 patients who presented with porto-systemic encephalopathy, 59(77.6%) had a positive H. pylori antibody test. Thirty-five of these were males and 24 were females. A significant number of patients who presented with higher grade of encephalopathy were H. pylori antibody positive (p<0.001). Conclusion: In this study, frequency of H. pylori antibodies was significantly high in patients of porto-systematic encephalopathy. (author)

  7. Colectomy for porto-systemic encephalopathy: is it still topical?

    Directory of Open Access Journals (Sweden)

    Rym Ennaifer

    2013-06-01

    Full Text Available Hepatic encephalopathy (HE is a common long term complication of porto-systemic shunt. We report herein the case of a 59-year-old man with Child-Pugh A cirrhosis treated successfully 9 years earlier with distal splenorenal shunt for uncontrolled variceal bleeding. In the last year, he developed a severe and persistent hepatic encephalopathy secondary to the shunt, which was resistant to medical therapy. As liver transplantation was not available and obliteration of the shunt was hazardous, we performed subtotal colectomy in order to reduce ammonia production. This therapeutic option proved successful, as the grade of encephalopathy decreased and the patient improved. Our experience indicates that colonic exclusion should be considered as an option in the management of HE refractory to medical treatment in highly selected patients when liver transplantation is not available or even as a bridge given the long waiting time on lists.

  8. Solar prominences

    CERN Document Server

    Engvold, Oddbjørn

    2015-01-01

    This volume presents the latest research results on solar prominences, including new developments on e.g. chirality, fine structure, magnetism, diagnostic tools and relevant solar plasma physics. In 1875 solar prominences, as seen out of the solar limb, were described by P.A. Secchi in his book Le Soleil as "gigantic pink or peach-flower coloured flames". The development of spectroscopy, coronagraphy and polarimetry brought tremendous observational advances in the twentieth century. The authors present and discuss exciting new challenges (resulting from observations made by space and ground-based telescopes in the 1990s and the first decade of the 21st century) concerning the diagnostics of prominences, their formation, their life time and their eruption along with their impact in the heliosphere (including the Earth). The book starts with a general introduction of the prominence “object” with some historical background on observations and instrumentation. In the next chapter, the various forms of promine...

  9. The Changing Collateral Space

    OpenAIRE

    Manmohan Singh

    2013-01-01

    This paper highlights the changing collateral landscape and how it may shape the global demand/supply for collateral. We first identify the key collateral pools (relative to the “old” collateral space) and associated collateral velocities. Post-Lehman and continuing into the European crisis, some aspects of unconventional monetary policies pursued by central banks are significantly altering the collateral space. Moreover, regulatory demands stemming from Basel III, Dodd Frank, EMIR etc., new ...

  10. The Collateral Trap

    OpenAIRE

    Frédéric Boissay; Russell Cooper

    2014-01-01

    Active wholesale financial markets help reallocate deposits across heterogeneous banks. Because of incentive problems these flows are constrained and collateral is needed. The composition of collateral matters. The use of inside assets (loans) creates a “collateral pyramid” in that cash flows from one loan can be pledged to secure another. Through collateral pyramids the financial sector creates safe assets, but at the cost of exposing the economy to systemic panics. Outside collateral (treas...

  11. Lateral collateral ligament (image)

    Science.gov (United States)

    The lateral collateral ligament connects the end of the femur (thigh) to the top of the fibula (the thin bone that runs next to the shin bone). The lateral collateral ligament provides stability against varus stress. Varus stress ...

  12. Discounting with Imperfect Collateral

    OpenAIRE

    Lou, Wujiang

    2017-01-01

    Cash collateral is perfect in that it provides simultaneous counterparty credit risk protection and derivatives funding. Securities are imperfect collateral, because of collateral segregation or differences in CSA haircuts and repo haircuts. Moreover, the collateral rate term structure is not observable in the repo market, for derivatives netting sets are perpetual while repo tenors are typically in months. This article synthesizes these effects into a derivative financing rate that replaces ...

  13. Transjugular intrahepatic porto-systemic shunt in the elderly: Palliation for complications of portal hypertension

    Science.gov (United States)

    Syed, Mubin I; Karsan, Hetal; Ferral, Hector; Shaikh, Azim; Waheed, Uzma; Akhter, Talal; Gabbard, Alan; Morar, Kamal; Tyrrell, Robert

    2012-01-01

    AIM: To present a dedicated series of transjugular intrahepatic porto-systemic shunts (TIPS) in the elderly since data is sparse on this population group. METHODS: A retrospective review was performed of patients at least 65 years of age who underwent TIPS at our institutions between 1997 and 2010. Twenty-five patients were referred for TIPS. We deemed that 2 patients were not considered appropriate candidates due to their markedly advanced liver disease. Of the 23 patients suitable for TIPS, the indications for TIPS placement was portal hypertension complicated by refractory ascites alone (n = 9), hepatic hydrothorax alone (n = 2), refractory ascites and hydrothorax (n = 1), gastrointestinal bleeding alone (n = 8), gastrointestinal bleeding and ascites (n = 3). RESULTS: Of these 23 attempted TIPS procedure patients, 21 patients had technically successful TIPS procedures. A total of 29 out of 32 TIPS procedures including revisions were successful in 21 patients with a mean age of 72.1 years (range 65-82 years). Three of the procedures were unsuccessful attempts at TIPS and 8 procedures were successful revisions of our existing TIPS. Sixteen of 21 patients who underwent successful TIPS (excluding 5 patients lost to follow-up) were followed for a mean of 14.7 mo. Ascites and/or hydrothorax was controlled following technically successful procedures in 12 of 13 patients. Bleeding was controlled following technically successful procedures in 10 out of 11 patients. CONCLUSION: We have demonstrated that TIPS is an effective procedure to control refractory complications of portal hypertension in elderly patients. PMID:22400084

  14. Collateral vessels in moyamoya disease : comparison of MR and MRA with conventional angiography

    International Nuclear Information System (INIS)

    Shim, Joo Eun; Yoon, Dae Young; Yi, Jeong Geun; Kim, Ho Chul; Choi, Chul Sun; Bae, Sang Hoon

    1998-01-01

    To determine the value of magnetic resonance imaging (MR) and magnetic resonance angiography (MRA) in assessing collateral vessels of moyamoya disease. Twenty-four patients with moyamoya disease who underwent MR, 3D TOF MRA, and conventional angiography participated in this study. Two radiologists working independently and with no knowledge of the angiographic findings, interpreted the MR and MRA images. To determine the presence of parenchymal and leptomeningeal collaterals (48 hemispheres) and transdural collaterals (38 hemispheres in 19 patients were depicted by angiography of the external carotid), the findings were compared with those of angiography. Parenchymal, leptomeningeal, and transdural collaterals were depicted by conventional angiography in 34 (71%), 32 (67%), and 11 (29%) hemispheres respectively. The sensitivity and specificity of MR/MRA for collateral vessels were 79.1/88.1 % for parenchymal collaterals, 72.1/88.1 % for leptomeningeal collaterals, and 0.1/18.1 % for transdural collaterals, respectively. Respective sensitivity and specificity of MR/MRA were 88.94/94.1% for leptomeningeal collaterals, and 18.93/55.1 % for transdural collaterals, when the prominent posterior cerebral and external carotid artery were regarded as secondary signs of leptomeningeal and transdural collateral vessels. In moyamoya disease, MR and MRA are useful imaging modalities for the assessment of collateral vessels. The prominent posterior cerebral artery and external carotid artery can be useful secondary signs of leptomeningeal and transdural collateral vessels. (author). 18 refs., 2 figs

  15. Loan collaterals and collateral substitutes in rural finance: a review ...

    African Journals Online (AJOL)

    Loan collaterals and collateral substitutes in rural finance: a review. ... have difficulties in obtaining loans from banks and other financial institutions because ... The limited availability of conventional collaterals in rural financial markets has led ...

  16. Globus pallidus MR signal abnormalities in children with chronic liver disease and/or porto-systemic shunting

    Energy Technology Data Exchange (ETDEWEB)

    Hanquinet, Sylviane; Anooshiravani, Mehrak; Merlini, Laura [University Hospital of Geneva, Department of Pediatric Radiology, Geneva (Switzerland); Morice, Claire; Cousin, Vladimir; McLin, Valerie A. [University Hospital of Geneva, Swiss Center for Liver Disease in Children, Geneva (Switzerland); Courvoisier, Delphine S. [University Hospital of Geneva, Division of Quality of Care, Geneva (Switzerland)

    2017-10-15

    Detection of subclinical hepatic encephalopathy in children is difficult. We aimed to assess the changes in imaging of the central nervous system in children with chronic liver disease using MR imaging, diffusion, and {sup 1}H -spectroscopy. Forty three children with chronic liver disease and/or porto-systemic shunting (111.4±56.9 months) and 24 controls (72.0±51.8 months) underwent brain MRI/spectroscopy on a 1.5T to examine T1, T2, ADC, Cho/Cr, ml/Cr, Glx/Cr ratio spectroscopy in the globus pallidus. Patients were divided into 3 groups according to the ratios of globus pallidus/putamen T1 signal: isointense (i), hyperintense (h), much more hyperintense (h+). The relationship with clinical and biological data was analyzed. T1 signal intensity and ml/Cr were significantly different between controls and group h+ (p=0.001). ADC did not differ significantly between groups. Age correlated strongly with the presence of a T1 signal ratio (p > 0.001). There was no correlation between imaging findings and biological parameters. In children with chronic liver disease and/or porto-systemic shunting, the presence of a hyperintense T1 signal in the globus pallidus correlated strongly with age. Biological and clinical parameters were not predictive of these changes. MRI may become a useful screening tool for hepatic encephalopathy in children. (orig.)

  17. Globus pallidus MR signal abnormalities in children with chronic liver disease and/or porto-systemic shunting

    International Nuclear Information System (INIS)

    Hanquinet, Sylviane; Anooshiravani, Mehrak; Merlini, Laura; Morice, Claire; Cousin, Vladimir; McLin, Valerie A.; Courvoisier, Delphine S.

    2017-01-01

    Detection of subclinical hepatic encephalopathy in children is difficult. We aimed to assess the changes in imaging of the central nervous system in children with chronic liver disease using MR imaging, diffusion, and "1H -spectroscopy. Forty three children with chronic liver disease and/or porto-systemic shunting (111.4±56.9 months) and 24 controls (72.0±51.8 months) underwent brain MRI/spectroscopy on a 1.5T to examine T1, T2, ADC, Cho/Cr, ml/Cr, Glx/Cr ratio spectroscopy in the globus pallidus. Patients were divided into 3 groups according to the ratios of globus pallidus/putamen T1 signal: isointense (i), hyperintense (h), much more hyperintense (h+). The relationship with clinical and biological data was analyzed. T1 signal intensity and ml/Cr were significantly different between controls and group h+ (p=0.001). ADC did not differ significantly between groups. Age correlated strongly with the presence of a T1 signal ratio (p > 0.001). There was no correlation between imaging findings and biological parameters. In children with chronic liver disease and/or porto-systemic shunting, the presence of a hyperintense T1 signal in the globus pallidus correlated strongly with age. Biological and clinical parameters were not predictive of these changes. MRI may become a useful screening tool for hepatic encephalopathy in children. (orig.)

  18. Using collateral to secure loans

    OpenAIRE

    Yaron Leitner

    2006-01-01

    In “Using Collateral to Secure Loans,” Yaron Leitner asks: Why is collateral used to secure some loans, but not others? And why does collateral potentially involve more risk? He considers these questions, looking at some of the explanations for using collateral, focusing on its benefits and drawbacks.

  19. Military Robotics and Collateral Damage

    National Research Council Canada - National Science Library

    Kott, Robert Douglass ;Alexander

    2004-01-01

    .... Such concepts raise important questions in terms of their impact on collateral damage. In a broader context, western warfare in general places a continuously growing emphasis on issues of collateral damage...

  20. Collateral Intimate Partner Homicide

    Directory of Open Access Journals (Sweden)

    Emily Meyer

    2013-04-01

    Full Text Available Collateral intimate partner homicide (CIPH is an underinvestigated genre of intimate partner violence (IPV where an individual(s connected to the IPV victim is murdered. We conducted a content analysis of a statewide database of CIPH newspaper articles (1990-2007. Out of 111 collateral murder victims, there were 84 IPV female focal victims and 84 male perpetrators. The most frequently reported CIPH decedent was the focal victim’s new partner (30%; 45% of focal victims were themselves killed. News reports framed CIPH as the unexpected result of interpersonal conflict, despite evidence of a systematic pattern of coercion and violence that capitulated in murder.

  1. Trans-jugular intrahepatic porto-systemic shunt placement for refractory ascites: a 'real-world' UK health economic evaluation.

    Science.gov (United States)

    Parker, Matthew J; Guha, Neil; Stedman, Brian; Hacking, Nigel; Wright, Mark

    2013-07-01

    To assess the benefit of trans-jugular intrahepatic porto-systemic shunt (TIPS) placement for refractory ascites. A retrospective observational study of all patients undergoing TIPS for refractory ascites in our hospital between 2003 and 2012. Secondary care. Cirrhotic patients with refractory ascites. We examined direct real-world (National Health Service) health related costs in the year before and after the TIPS procedure took place. Data were collected relating to the need for reintervention and hepatic encephalopathy. Data were available for 24 patients who underwent TIPS for refractory ascites (86% of eligible patients). TIPS was technically successful in all cases. Mean number of bed days in the year prior to TIPS was 30.3 and 14.3 in the year following (p=0.005). No patient had ascites at the end of the year after the TIPS with less requirement for paracentesis over the course of the year (p<0.001). Mean reduction in cost was £2759 per patient. TIPS was especially cost-effective in patients requiring between 6 and 12 drains per year with a mean saving of £9204 per patient. TIPS is both a clinically effective and economically advantageous therapeutic option for selected patients with refractory ascites.

  2. Transjugular Intrahepatic Porto-Systemic Stent-Shunt for Therapy of Bleeding Esophageal Varices Due to Extramedullary Hematopoiesis in Primary Myelofibrosis: A Case Report

    OpenAIRE

    Phillip, Veit;Berger, Hermann;Straub, Melanie;Saugel, Bernd;Treiber, Matthias;Einwächter, Henrik;Schmid, Roland M.;Huber, Wolfgang

    2016-01-01

    Background: Primary myelofibrosis belongs to the group of myeloproliferative syndromes. Extramedullary hematopoiesis in the liver can lead to portal hypertension. Patient and Methods: We report a case of a patient with life-threatening, endoscopically not treatable bleeding from esophageal varices due to extramedullary hematopoiesis of the liver that was successfully treated with placement of a transjugular intrahepatic porto-systemic stent-shunt (TIPS). Results: Therapy of variceal bleeding ...

  3. Brandburg Prominance, Namibia, Africa

    Science.gov (United States)

    1993-01-01

    The Brandburg Prominance, Namibia (21.0S, 14.5E) is a round basaltic plug and is the highest feature (over 8,000 ft) in the country. Wind streaks on the surface of the coastal desert, aligned northeast to southwest, are the result of frequent sand storms. Coastal stratus clouds provide most of the life supporting moisture as fog droplets in this arid land where annual rainfall may be less than a quarter of an inch for decades at a time.

  4. Clinical analysis of long-term outcomes of re-intervention of transjugular intrahepatic porto-systemic shunt

    International Nuclear Information System (INIS)

    Liu Fuquan; Yue Zhendong; Zhao Hongwei

    2012-01-01

    Objective: To evaluate the safety,effectiveness and clinical factors of re-intervention of transjugular intrahepatic porto-systemic shunt (TIPS). Methods: A retrospective study of safety and long-term outcomes of TIPS was made in 771 patients from August 1994 to August 2010. The 625 patients had follow-up data.The patients who received TIPS once, twice, and more than twice were divided into group 1, group 2 and group 3, respectively. Clinical symptoms, survival rate and restenosis rate of each group were analyzed. Clinical influencing factors of re-intervention effect were discussed. Results: The success rate of first intervention was 98.2% (757/771), the death rate was 0.7% (5/757) and severe complication rate was 2.5% (19/757). The success rate of re-intervention was 98.7% (457/463), no death and severe complications occurred. The restenosis rate in group 3 decreased significantly than group 1 (χ 2 =7.908, P<0.05) in the first year of TIPS. The restenosis rates in group 2 and group 3 were lower than group 1 from 2 to 5 years of TIPS (χ2 values were 27.046, 25.724, 37.002 and 19.046, respectively, P<0.05). The survival rate in group 3 was higher than group 1 (χ 2 =9.114, P<0.05)and group 2 was higher than group 1 (χ 2 =4.929, P<0.05) in the first year of TIPS, while there was no statistical difference between group 2 and group 3 (χ 2 =2.678, P>0.05). The patients in group 2 and group 3 also had higher survival rates than group 1 from 2 to 5 years of TIPS (χ 2 value were 41.314, 26.920, 13.692 and 6.713, respectively, P<0.05). 19.4% (79/406) of patients who received re-intervention had symptom recurrence and shunt stenosis or occlusion. 11.6% (47/406) of patients had symptom recurrence with portal hypertension signs, 62.8% (255/406) had shunt stenosis or occlusion with portal hypertension signs. Conclusions: Restenosis or occlusion of TIPS, symptom recurrence and portal hypertension signs were important factors for re-intervention. Re-intervention of TIPS was

  5. Formation and support of prominence

    International Nuclear Information System (INIS)

    Forbes, T.G.

    1986-01-01

    A short introduction is given to the concepts discussed by the group on the formation and support of prominences. Only quiescent and long-lived active region prominences were considered, since transient prominence phenomena, such as sprays, surges, H alpha flare-loops, and coronal rain, are dynamically distinct from long-lived, prominences. Stable prominences (which are often referred to as filaments when seen against the disk) can be subdivided into three categories, namely active region prominences, quiescent prominences and polar crown prominences. The third category is closely related to the second since a quiescent prominence will eventually evolve into a polar crown prominence if it lasts long enough. The distinction between the first and second categories is not sharp either since intermediates exist here as well (Martin, 1973)

  6. Collateralized debt obligations (CDOs

    Directory of Open Access Journals (Sweden)

    Dragosavac Miloš

    2012-01-01

    Full Text Available Collateralized debt obligations (CDOs were issued in 1987 by bankers at Drexel Burnham Lambert Inc. A decade later, CDOs became the leading power on the credit derivative markets, on which the value of derivative assets was derived from the value of other assets. However, unlike options and credit swamps, CDOs are not real, which means that they are constructed, and sometimes even the construction of their construction. CDOs were made to satisfy different types of investors, at one end, there is low-risk with low-income, and at the other, high-risk with high-income. By 2007, following the bubble burst on the US real estate market, losses on the CDO market started to expand. By 2008, the crisis on the CDO market turned into what we call today 'the global financial crisis.' CDOs are 'in the heart' of the crisis, and even wider. Our attempt is to reveal the mechanism of collateralized debt obligations (CDOs and the way in which CDOs expanded the negative effects of the present global financial crisis.

  7. 24 CFR 330.10 - Eligible collateral.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Eligible collateral. 330.10 Section... SECURITIES § 330.10 Eligible collateral. The Association, in its discretion, shall determine what collateral is eligible for inclusion in the Multiclass Securities program. Eligible collateral may include GNMA...

  8. 7 CFR 1980.331 - Collateral.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 14 2010-01-01 2009-01-01 true Collateral. 1980.331 Section 1980.331 Agriculture... REGULATIONS (CONTINUED) GENERAL Rural Housing Loans § 1980.331 Collateral. (a) General. The entire loan must... borrower. (c) All collateral must secure the entire loan. The Lender will not take separate collateral...

  9. Solar Features - Prominences and Filaments

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Prominences and filaments are two manifestations of the same phenomenon. Both prominences and filaments are features formed above the chromosphere by cool dense...

  10. A Framework for Collateral Risk Control Determination

    OpenAIRE

    Didier Cossin; Zhijiang Huang; Daniel Aunon-Nerin; Fer nando González

    2002-01-01

    This paper derives a general framework for collateral risk control determination in repurchase transactions or repos. The objective is to treat consistently heterogeneous collateral so that the collateral taker has a similar risk exposure whatever the collateral pledged. The framework measures the level of risk with the probability of incurring a loss higher than a pre-specified level given two well-known parameters used to manage the intrinsic risk of collateral: marking to market and haircu...

  11. New perspectives on solar prominences

    Science.gov (United States)

    Schmieder, B.; Aulanier, G.

    2012-06-01

    Recent observations of prominences obtained with high spatial and temporal resolution instruments, on board satellites (Hinode, SDO) as well as on the ground (SST) have provided very intriguing movies and open a new area for understanding the nature of prominences. The main topics are still debate: formation, dynamics, and characteristics of the plasma in the core and in the transition zone between the prominence and corona. We will review briefly the recent advances made in these topics, observationally as well as theoretically.

  12. Transjugular intrahepatic porto-systemic stent-shunt for therapy of bleeding esophageal varices due to extramedullary hematopoiesis in primary myelofibrosis: a case report.

    Science.gov (United States)

    Phillip, Veit; Berger, Hermann; Straub, Melanie; Saugel, Bernd; Treiber, Matthias; Einwächter, Henrik; Schmid, Roland M; Huber, Wolfgang

    2012-01-01

    Primary myelofibrosis belongs to the group of myeloproliferative syndromes. Extramedullary hematopoiesis in the liver can lead to portal hypertension. We report a case of a patient with life-threatening, endoscopically not treatable bleeding from esophageal varices due to extramedullary hematopoiesis of the liver that was successfully treated with placement of a transjugular intrahepatic porto-systemic stent-shunt (TIPS). Therapy of variceal bleeding by TIPS insertion was successful. During a 29-month follow-up, no hepatic failure, hepatic encephalopathy, or further variceal bleeding episode occurred. TIPS placement is a well-established procedure for the treatment of complications due to portal hypertension mainly due to liver cirrhosis. This report illustrates that TIPS placement can also be a promising treatment option in patients with primary myelofibrosis and portal hypertension due to extramedullary hematopoiesis. Copyright © 2012 S. Karger AG, Basel.

  13. Dynamics of the Collateral Encyclopedia

    DEFF Research Database (Denmark)

    Thellefsen, Torkild Leo; Sørensen, Bent; Thellefsen, Martin Muderspach

    2015-01-01

    Both Umberto Eco and Charles S. Peirce have been concerned with the notion of background knowledge. Eco refers to background knowledge as the encyclopedia; Peirce’s term of reference is collateral experience. The aim of this article is to investigate the degree to which these two concepts...... are comparable. We focus on one major metaphysical issue, viz. the fact that Eco defines collateral experience, which is the first step in any process of cognition, as private, whereas Peirce, as a realist, would never accept the concept of private thoughts, feelings, etc. We suggest that freeing collateral...... experience from its nominalistic nomenclature makes possible a comparison and synthesis of Eco’s and Peirce’s conceptions when seen from the perspectives of their cognitive type, nuclear type, and molar content....

  14. 12 CFR 950.7 - Collateral.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Collateral. 950.7 Section 950.7 Banks and... Advances to Members § 950.7 Collateral. (a) Eligible security for advances to all members. At the time of... interest in collateral that meets the requirements of one or more of the following categories: (1) Mortgage...

  15. 28 CFR 94.25 - Collateral sources.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Collateral sources. 94.25 Section 94.25... Victim Expense Reimbursement Program Coverage § 94.25 Collateral sources. (a) The amount of expenses... collateral source in connection with the same act of international terrorism. In cases in which a claimant...

  16. 30 CFR 800.21 - Collateral bonds.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Collateral bonds. 800.21 Section 800.21 Mineral... FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS UNDER REGULATORY PROGRAMS § 800.21 Collateral bonds. (a) Collateral bonds, except for letters of credit, cash accounts, and real property, shall be...

  17. 25 CFR 502.5 - Collateral agreement.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Collateral agreement. 502.5 Section 502.5 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR GENERAL PROVISIONS DEFINITIONS OF THIS CHAPTER § 502.5 Collateral agreement. Collateral agreement means any contract, whether or not in writing...

  18. 7 CFR 1779.48 - Collateral.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false Collateral. 1779.48 Section 1779.48 Agriculture... (CONTINUED) WATER AND WASTE DISPOSAL PROGRAMS GUARANTEED LOANS § 1779.48 Collateral. (a) Lender responsibility. The lender is responsible for obtaining and maintaining proper and adequate collateral to protect...

  19. 13 CFR 120.934 - Collateral.

    Science.gov (United States)

    2010-01-01

    ... Loan Program (504) 504 Loans and Debentures § 120.934 Collateral. The CDC usually takes a second lien position on the Project Property to secure the 504 loan. Sometimes additional collateral is required. (In... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Collateral. 120.934 Section 120...

  20. 12 CFR 615.5050 - Collateral requirements.

    Science.gov (United States)

    2010-01-01

    ... provided in this paragraph, the collateral value of notes and other obligations representing loans made... allowance for loan losses (except as provided for in § 615.5090). (2) The collateral value of loans in... loans, judgments, and contracts adjusted for any allowance for losses. (3) The collateral value of loans...

  1. Understanding Collateral Evolution in Linux Device Drivers

    DEFF Research Database (Denmark)

    Padioleau, Yoann; Lawall, Julia Laetitia; Muller, Gilles

    2006-01-01

    no tools to help in this process, collateral evolution is thus time consuming and error prone.In this paper, we present a qualitative and quantitative assessment of collateral evolution in Linux device driver code. We provide a taxonomy of evolutions and collateral evolutions, and use an automated patch......-analysis tool that we have developed to measure the number of evolutions and collateral evolutions that affect device drivers between Linux versions 2.2 and 2.6. In particular, we find that from one version of Linux to the next, collateral evolutions can account for up to 35% of the lines modified in such code....

  2. The dynamics of the coronary collateral circulation.

    Science.gov (United States)

    Zimarino, Marco; D'Andreamatteo, Mariangela; Waksman, Ron; Epstein, Stephen E; De Caterina, Raffaele

    2014-04-01

    Coronary collaterals are present at birth, with wide interindividual variation in their functional capacity. These vessels protect jeopardized myocardium, and the number of collaterals and the extent of their coverage are associated with improved survival in patients with coronary heart disease. The collateral circulation is not a permanent set of structures, but undergoes dynamic changes with important consequences for cardioprotection. If a severe atherosclerotic lesion develops in an artery supplying tissue downstream of a total occlusion through collateral blood flow, pressure gradients across the collateral bed change. The result is that some of the collateral flow previously supplying the perfusion territory of the totally occluded artery is redirected to the perfusion territory of the donor artery, thus producing a 'collateral steal'. The collateral circulation can regress once antegrade flow in the main dependent artery is re-established, as occurs following the recanalization of a chronic total occlusion. The clinical benefits of coronary revascularization must be cautiously weighed against the risk of reducing the protective support derived from coronary collaterals. Consequently, pharmacological, gene-based, and cell-based therapeutic attempts have been made to enhance collateral function. Although such approaches have so far yielded no, or modest, beneficial results, the rapidly accruing data on coronary collateral circulation will hopefully lead to new effective therapeutic strategies.

  3. Evaluation of Collateral Source Characteristics With 3-Dimensional Analysis Using Micro-X-Ray Computed Tomography.

    Science.gov (United States)

    Arima, Yuichiro; Hokimoto, Seiji; Tabata, Noriaki; Nakagawa, Osamu; Oshima, Asahi; Matsumoto, Yosuke; Sato, Takahiro; Mukunoki, Toshifumi; Otani, Jun; Ishii, Masanobu; Uchikawa, Michie; Yamamoto, Eiichiro; Izumiya, Yasuhiro; Kaikita, Koichi; Ogawa, Hisao; Nishiyama, Koichi; Tsujita, Kenichi

    2018-03-23

    Collateral arteries provide an alternative blood supply and protect tissues from ischemic damage in patients with peripheral artery disease. However, the mechanism of collateral artery development is difficult to validate. Collateral arteries were visualized using micro-x-ray computed tomography. Developmental characteristics were assessed using confocal microscopy. We conducted a single-center, retrospective, observational study and assessed the dilatation of collateral arteries on ischemic sides. We quantified the vascular volume in both ischemic and nonischemic legs. A prominent increase in vascular volume was observed in the ischemic leg using a murine hind-limb ischemia model. We also performed qualitative assessment and confirmed that the inferior gluteal artery functioned as a major collateral source. Serial analysis of murine hind-limb vessel development revealed that the inferior gluteal artery was a remnant of the ischial artery, which emerged as a representative vessel on the dorsal side during hind-limb organogenesis. We retrospectively analyzed consecutive patients who were admitted for the diagnosis or treatment of peripheral artery disease. The diameter of the inferior gluteal artery on the ischemic side showed significant dilatation compared with that on the nonischemic side. Our findings indicate that an embryonic remnant artery can become a collateral source under ischemic conditions. Flow enhancement in the inferior gluteal artery might become a novel therapeutic approach for patients with peripheral artery disease. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  4. Ulnar Collateral Ligament Injuries of the Thumb

    Science.gov (United States)

    McKeon, Kathleen E.; Gelberman, Richard H.; Calfee, Ryan P.

    2013-01-01

    Background: The clinical diagnosis of thumb ulnar collateral ligament disruption has been based on joint angulation during valgus stress testing. This report describes a definitive method of distinguishing between complete and partial ulnar collateral ligament injuries by quantifying translation of the proximal phalanx on the metacarpal head during valgus stress testing. Methods: Sixty-two cadaveric thumbs underwent standardized valgus stress testing under fluoroscopy with the ulnar collateral ligament intact, following an isolated release of the proper ulnar collateral ligament, and following a combined release of both the proper and the accessory ulnar collateral ligament (complete ulnar collateral ligament release). Following complete ulnar collateral ligament release, the final thirty-seven thumbs were also analyzed after the application of a valgus force sufficient to cause 45° of valgus angulation at the metacarpophalangeal joint to model more severe soft-tissue injury. Two independent reviewers measured coronal plane joint angulation (in degrees), ulnar joint line gap formation (in millimeters), and radial translation of the proximal phalanx on the metacarpal head (in millimeters) on digital fluoroscopic images that had been randomized. Results: Coronal angulation across the stressed metacarpophalangeal joint progressively increased through the stages of the testing protocol: ulnar collateral ligament intact (average [and standard deviation], 20° ± 8.1°), release of the proper ulnar collateral ligament (average, 23° ± 8.3°), and complete ulnar collateral ligament release (average, 30° ± 8.9°) (p collateral ligament release (5.7 ± 1.5 mm), to that following complete ulnar collateral ligament release (7.2 ± 1.5 mm) (p collateral ligament (1.6 ± 0.8 mm vs. 1.5 ± 0.9 mm in the intact state). There was a significant increase in translation following release of the complete ulnar collateral ligament complex (3.0 ± 0.9 mm; p collateral ligament

  5. Trans-jugular intrahepatic porto-systemic shunt placement for refractory ascites: a ‘real-world’ UK health economic evaluation

    Science.gov (United States)

    Parker, Matthew J; Guha, Neil; Stedman, Brian; Hacking, Nigel; Wright, Mark

    2013-01-01

    Objective To assess the benefit of trans-jugular intrahepatic porto-systemic shunt (TIPS) placement for refractory ascites. Design A retrospective observational study of all patients undergoing TIPS for refractory ascites in our hospital between 2003 and 2012. Setting Secondary care. Patients Cirrhotic patients with refractory ascites. Main outcome measures We examined direct real-world (National Health Service) health related costs in the year before and after the TIPS procedure took place. Data were collected relating to the need for reintervention and hepatic encephalopathy. Results Data were available for 24 patients who underwent TIPS for refractory ascites (86% of eligible patients). TIPS was technically successful in all cases. Mean number of bed days in the year prior to TIPS was 30.3 and 14.3 in the year following (p=0.005). No patient had ascites at the end of the year after the TIPS with less requirement for paracentesis over the course of the year (p<0.001). Mean reduction in cost was £2759 per patient. TIPS was especially cost-effective in patients requiring between 6 and 12 drains per year with a mean saving of £9204 per patient. Conclusions TIPS is both a clinically effective and economically advantageous therapeutic option for selected patients with refractory ascites. PMID:28839725

  6. The PLAU P141L single nucleotide polymorphism is associated with collateral circulation in patients with coronary artery disease.

    Science.gov (United States)

    Duran, Joan; Sánchez-Olavarría, Pilar; Mola, Marina; Götzens, Víctor; Carballo, Julio; Martín-Pelegrina, Eva; Petit, Màrius; García Del Blanco, Bruno; García-Dorado, David; de Anta, Josep M

    2014-07-01

    Urokinase-type plasminogen activator, which is encoded by the PLAU gene, plays a prominent role during collateral arterial growth. We investigated whether the PLAU P141L (C > T) polymorphism, which causes a mutation in the kringle domain of the protein, is associated with coronary collateral circulation in a cohort of 676 patients with coronary artery disease. The polymorphism was genotyped in blood samples using a TaqMan-based genotyping assay, and collateral circulation was assessed by the Rentrop method. Multivariate logistic regression models adjusted by clinically relevant variables to estimate odds ratios were used to examine associations of PLAU P141L allelic variants and genotypes with collateral circulation. Patients with poor collateral circulation (Rentrop 0-1; n = 547) showed a higher frequency of the TT genotype than those with good collateral circulation (Rentrop 2-3; n = 129; P = .020). The T allele variant was also more common in patients with poor collateral circulation (P = .006). The odds ratio of having poorly developed collaterals in patients bearing the T allele (adjusted for clinically relevant variables) was statistically significant under the dominant model (odds ratio = 1.83 [95% confidence interval, 1.16-2.90]; P = .010) and the additive model (odds ratio = 1.73 [95% confidence interval, 1.14-2.62]; P = .009). An association was found between coronary collateral circulation and the PLAU P141L polymorphism. Patients with the 141L variant are at greater risk of developing poor coronary collateral circulation. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

  7. Collateral in Loan Classification and Provisioning

    OpenAIRE

    In W Song

    2002-01-01

    Adequate loan classification practices are an essential part of a sound and effective credit risk-management process in a bank. Failure to identify deterioration in credit quality in a timely manner can aggravate and prolong the problem. Two key issues arise with regard to the use of collateral in the context of loan classification and provisioning. In particular, the questions arise whether collateral should be taken into account in classifying a collateralized loan, and whether it should be...

  8. Reexamining the empirical relation between loan risk and collateral: The roles of collateral characteristics and types

    OpenAIRE

    Berger, Allen N.; Frame, Scott; Ioannidou, Vasso

    2011-01-01

    This paper offers a possible explanation for the conflicting empirical results in the literature concerning the relation between loan risk and collateral. Specifically, we posit that different economic characteristics or types of collateral pledges may be associated with the empirical dominance of the four different risk-collateral channels implied by economic theory. For our sample, collateral overall is associated with lower loan risk premiums and a higher probability of ex post loan nonper...

  9. Multiple coil closure of isolated aortopulmonary collateral

    Directory of Open Access Journals (Sweden)

    Padhi Sumanta

    2010-01-01

    Full Text Available A 7-month-old girl was diagnosed to have large aortopulmonary collateral during evaluation for congestive heart failure. There was no other evidence of cardiopulmonary disease. The collateral was successfully closed with multiple coils delivered sequentially. We describe the issues associated during closure of the aortopulmonary collateral in this case. To the best of our knowledge, this is the first reported case of large aortopulmonary collateral presenting with heart failure in an otherwise structurally normal heart that was closed successfully with multiple coils delivered sequentially.

  10. Effects of exercise training on coronary collateralization and control of collateral resistance

    Science.gov (United States)

    Parker, Janet L.

    2011-01-01

    Coronary collateral vessels serve as a natural protective mechanism to provide coronary flow to ischemic myocardium secondary to critical coronary artery stenosis. The innate collateral circulation of the normal human heart is typically minimal and considerable variability occurs in extent of collateralization in coronary artery disease patients. A well-developed collateral circulation has been documented to exert protective effects upon myocardial perfusion, contractile function, infarct size, and electrocardiographic abnormalities. Thus therapeutic augmentation of collateral vessel development and/or functional adaptations in collateral and collateral-dependent arteries to reduce resistance into the ischemic myocardium represent a desirable goal in the management of coronary artery disease. Tremendous evidence has provided documentation for the therapeutic benefits of exercise training programs in patients with coronary artery disease (and collateralization); mechanisms that underlie these benefits are numerous and multifaceted, and currently under investigation in multiple laboratories worldwide. The role of enhanced collateralization as a major beneficial contributor has not been fully resolved. This topical review highlights literature that examines the effects of exercise training on collateralization in the diseased heart, as well as effects of exercise training on vascular endothelial and smooth muscle control of regional coronary tone in the collateralized heart. Future directions for research in this area involve further delineation of cellular/molecular mechanisms involved in effects of exercise training on collateralized myocardium, as well as development of novel therapies based on emerging concepts regarding exercise training and coronary artery disease. PMID:21565987

  11. The most prominent safety guarantees

    International Nuclear Information System (INIS)

    Lucenet, G.

    1978-01-01

    The Creys-Malville Nuclear Centre has been designed using the safety analysis implemented since the beginning of the developments of breeder reactors in France and the Super Phenix follows almost the same safety regulations as its predecessor the Phenix reactor. These regulations are based on: 'Recommendations for the safety standards of the Super Phenix' drawn up by the French Safety Authorities in July 1973. The prominent points are summarised. (C.F.)

  12. Sex Differences in the Cerebral Collateral Circulation.

    Science.gov (United States)

    Faber, James E; Moore, Scott M; Lucitti, Jennifer L; Aghajanian, Amir; Zhang, Hua

    2017-06-01

    Premenopausal women and intact female rodents sustain smaller cerebral infarctions than males. Several sex-dependent differences have been identified as potential contributors, but many questions remain unanswered. Mice exhibit wide variation in native collateral number and diameter (collateral extent) that is dependent on differences in genetic background, aging, and other comorbidities and that contributes to their also-wide differences in infarct volume. Likewise, variation in infarct volume correlates with differences in collateral-dependent blood flow in patients with acute ischemic stroke. We examined whether extent of pial collateral arterioles and posterior communicating collateral arteries (PComAs) differ depending on sex in young, aged, obese, hypertensive, and genetically different mice. We combined new data with meta-analysis of our previously published data. Females of C57BL/6J (B6) and BALB/cByJ (BC) strains sustained smaller infarctions than males after permanent MCA occlusion. This protection was unchanged in BC mice after introgression of the B6 allele of Dce1, the major genetic determinant of variation in pial collaterals among mouse strains. Consistent with this, collateral extent in these and other strains did not differ with sex. Extent of PComAs and primary cerebral arteries also did not vary with sex. No dimorphism was evident for loss of pial collateral number and/or diameter (collateral rarefaction) caused by aging, obesity, and hypertension, nor for collateral remodeling after pMCAO. However, rarefaction was greater in females with long-standing hypertension. We conclude that smaller infarct volume in female mice is not due to greater collateral extent, greater remodeling, or less rarefaction caused by aging, obesity, or hypertension.

  13. Stroke etiology and collaterals: atheroembolic strokes have greater collateral recruitment than cardioembolic strokes.

    Science.gov (United States)

    Rebello, L C; Bouslama, M; Haussen, D C; Grossberg, J A; Dehkharghani, S; Anderson, A; Belagaje, S R; Bianchi, N A; Grigoryan, M; Frankel, M R; Nogueira, R G

    2017-06-01

    Chronic hypoperfusion from athero-stenotic lesions is thought to lead to better collateral recruitment compared to cardioembolic strokes. It was sought to compare collateral flow in stroke patients with atrial fibrillation (AF) versus stroke patients with cervical atherosclerotic steno-occlusive disease (CASOD). This was a retrospective review of a prospectively collected endovascular database. Patients with (i) anterior circulation large vessel occlusion stroke, (ii) pre-treatment computed tomography angiography (CTA) and (iii) intracranial embolism from AF or CASOD were included. CTA collateral patterns were evaluated and categorized into two groups: absent/poor collaterals (CTA collateral score 0-1) versus moderate/good collaterals (CTA collateral score 2-4). CT perfusion was also utilized for baseline core volume and evaluation of infarct growth. A total of 122 patients fitted the inclusion criteria, of whom 88 (72%) had AF and 34 (27%) CASOD. Patients with AF were older (P Collateral scores were lower in the AF group (P = 0.01) with patients having poor collaterals in 28% of cases versus 9% in the CASOD group (P = 0.03). Mortality rates (20% vs. 0%; P = 0.02) were higher in the AF patients whilst rates of any parenchymal hemorrhage (6% vs. 26%; P collaterals (odds ratio 4.70; 95% confidence interval 1.17-18.79; P = 0.03). Atheroembolic strokes seem to be associated with better collateral flow compared to cardioembolic strokes. This may in part explain the worse outcomes of AF-related stroke. © 2017 EAN.

  14. The Future of Collateral Artery Research

    Science.gov (United States)

    Hakimzadeh, Nazanin; Verberne, Hein J.; Siebes, Maria; Piek, Jan J.

    2014-01-01

    In the event of obstructive coronary artery disease, collateral arteries have been deemed an alternative blood source to preserve myocardial tissue perfusion and function. Monocytes play an important role in modulating this process, by local secretion of growth factors and extracellular matrix degrading enzymes. Extensive efforts have focused on developing compounds for augmenting the growth of collateral vessels (arteriogenesis). Nonetheless, clinical trials investigating the therapeutic potential of these compounds resulted in disappointing outcomes. Previous studies focused on developing compounds that stimulated collateral vessel growth by enhancing monocyte survival and activity. The limited success of these compounds in clinical studies, led to a paradigm shift in arteriogenesis research. Recent studies have shown genetic heterogeneity between CAD patients with sufficient and insufficient collateral vessels. The genetic predispositions in patients with poorly developed collateral vessels include overexpression of arteriogenesis inhibiting signaling pathways. New directions of arteriogenesis research focus on attempting to block such inhibitory pathways to ultimately promote arteriogenesis. Methods to detect collateral vessel growth are also critical in realizing the therapeutic potential of newly developed compounds. Traditional invasive measurements of intracoronary derived collateral flow index remain the gold standard in quantifying functional capacity of collateral vessels. However, advancements made in hybrid diagnostic imaging modalities will also prove to be advantageous in detecting the effects of pro-arteriogenic compounds. PMID:23638829

  15. 13 CFR 120.343 - Collateral.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Collateral. 120.343 Section 120.343 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Special Purpose Loans Export Working Capital Program (ewcp) § 120.343 Collateral. A Borrower must give SBA a first security...

  16. Cardiovascular risk factors and collateral artery formation.

    Science.gov (United States)

    de Groot, D; Pasterkamp, G; Hoefer, I E

    2009-12-01

    Arterial lumen narrowing and vascular occlusion is the actual cause of morbidity and mortality in atherosclerotic disease. Collateral artery formation (arteriogenesis) refers to an active remodelling of non-functional vascular anastomoses to functional collateral arteries, capable to bypass the site of obstruction and preserve the tissue that is jeopardized by ischaemia. Hemodynamic forces such as shear stress and wall stress play a pivotal role in collateral artery formation, accompanied by the expression of various cytokines and invasion of circulating leucocytes. Arteriogenesis hence represents an important compensatory mechanism for atherosclerotic vessel occlusion. As arteriogenesis mostly occurs when lumen narrowing by atherosclerotic plaques takes place, presence of cardiovascular risk factors (e.g. hypertension, hypercholesterolaemia and diabetes) is highly likely. Risk factors for atherosclerotic disease affect collateral artery growth directly and indirectly by altering hemodynamic forces or influencing cellular function and proliferation. Adequate collateralization varies significantly among atherosclerotic patients, some profit from the presence of extensive collateral networks, whereas others do not. Cardiovascular risk factors could increase the risk of adverse cardiovascular events in certain patients because of the reduced protection through an alternative vascular network. Likewise, drugs primarily thought to control cardiovascular risk factors might contribute or counteract collateral artery growth. This review summarizes current knowledge on the influence of cardiovascular risk factors and the effects of cardiovascular medication on the development of collateral vessels in experimental and clinical studies.

  17. 42 CFR 3.532 - Collateral estoppel.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Collateral estoppel. 3.532 Section 3.532 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS PATIENT SAFETY ORGANIZATIONS AND PATIENT SAFETY WORK PRODUCT Enforcement Program § 3.532 Collateral estoppel. When a final...

  18. 42 CFR 402.15 - Collateral estoppel.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Collateral estoppel. 402.15 Section 402.15 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS CIVIL MONEY PENALTIES, ASSESSMENTS, AND EXCLUSIONS General Provisions § 402.15 Collateral estoppel...

  19. 45 CFR 160.532 - Collateral estoppel.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Collateral estoppel. 160.532 Section 160.532 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES ADMINISTRATIVE DATA STANDARDS AND RELATED REQUIREMENTS GENERAL ADMINISTRATIVE REQUIREMENTS Procedures for Hearings § 160.532 Collateral estoppel. When a...

  20. 42 CFR 1003.114 - Collateral estoppel.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Collateral estoppel. 1003.114 Section 1003.114 Public Health OFFICE OF INSPECTOR GENERAL-HEALTH CARE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OIG AUTHORITIES CIVIL MONEY PENALTIES, ASSESSMENTS AND EXCLUSIONS § 1003.114 Collateral estoppel. (a) Where a...

  1. 20 CFR 498.114 - Collateral estoppel.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Collateral estoppel. 498.114 Section 498.114 Employees' Benefits SOCIAL SECURITY ADMINISTRATION CIVIL MONETARY PENALTIES, ASSESSMENTS AND RECOMMENDED EXCLUSIONS § 498.114 Collateral estoppel. In a proceeding under section 1129 of the Social Security Act that...

  2. Collateral circulations in inferior vena cava obstruction

    International Nuclear Information System (INIS)

    Lee, Jong Beum; Park, Jae Hyung; Han, Man Chung; Park, Soo Soung

    1985-01-01

    Obstruction of the inferior vena cava (IVC) is an uncommon condition, and the collateral pathway varies according to the level, extent, duration and the cause of obstruction. Membranous obstruction of IVC in its hepatic portion might be one of the principle cause among Korean, though not reported till now. Analytical study was performed in 26 cases of IVC obstruction with various cause. 1. The level of the obstruction showed relatively even distribution as follows, upper caval in 11 cases, middle caval in 6 cases and infrarenal in 9 cases. 2. The main cause of upper caval obstruction was membranous obstruction. 3. As a whole, the main collateral pathway was the central route (22 cases: 85%). 4. Characteristic collateral pathway unique to upper caval obstruction was transhepatic venous collateral, developed between the obstructed segment and unobstructed segment of IVC. 5. Scalloping of left cardiac border produced by pericardiophrenic venous collateral was characteristic simple chest x-ray finding in IVC obstruction

  3. Lateral collateral ligament of the elbow joint

    DEFF Research Database (Denmark)

    Olsen, Bo Sanderhoff; Vaesel, M T; Søjbjerg, Jens Ole

    1996-01-01

    The structure and kinematics of the lateral collateral ligament of the elbow joint were investigated in 10 cadaveric specimens. The lateral collateral ligament was observed to be a distinct part of the lateral collateral ligament complex. It contains posterior fibers that pass through the annular....... Division of the posterolateral capsule caused no further laxity. Cutting the lateral collateral ligament induced a maximum laxity of 11.8 degrees at 110 degrees of flexion in forced varus and a maximum laxity of 20.6 degrees at 110 degrees of flexion in forced external rotation. The corresponding maximal...... posterior radial head translation was observed at 80 degrees to 100 degrees of flexion and was 5.7 mm in forced varus and 8.1 mm in forced external rotation. This study suggests the lateral collateral ligament to be an important stabilizer of the humeroulnar joint and the radial head in forced varus...

  4. Retrograde approach for the recanalization of coronary chronic total occlusion: collateral selection and collateral related complication.

    Science.gov (United States)

    Ma, Jian-Ying; Qian, Ju-Ying; Ge, Lei; Fan, Bing; Wang, Qi-Bing; Yan, Yan; Zhang, Feng; Yao, Kang; Huang, Dong; Ge, Jun-Bo

    2013-03-01

    The retrograde approach through collaterals has been applied in the treatment of chronic total occlusion (CTO) lesions during percutaneous recanalization of coronary arteries. This study was to investigate the success rate of recanalization and collateral related complications in patients when using the retrograde approach. Eighty-four cases subjected to retrograde approach identified from July 2005 to July 2012 were included in this study. Patient characteristics, procedural outcomes and in-hospital clinical events were evaluated. Mean age of the patient was (59.6 ± 11.2) years old and 91.7% were men. The target CTO lesions were distributed among the left anterior descending artery in 45 cases (53.5%), left circumflex artery in one case (1.2%), right coronary artery in 34 cases (40.5%), and left main in four cases (4.8%). The overall success rate of recanalization was 79.8%. The septal collateral was three times more frequently used for retrograde access than the epicardial collateral, 68/84 (81%) vs. 16/84 (19%). Successful wire passage through the collateral channel was achieved in 58 (72.6%) patients. The success rate of recanalization was 93.1% (54/58) in patients with and 50% (13/26) in patients without successful retrograde wire passage of the collateral channel (P collaterals was achieved in 49 of 68 septal collaterals (72.1%) and in 9 of 16 epicardial collaterals (56.3%) (P = NS). There was no significant difference between the septal collateral group and the epicardial group in the success rate of recanalization after retrograde wire crossing the collaterals (91.8% vs. 100%, P > 0.05). CART or reverse CART technique was used in 15 patients, and 14 patients (93.3%) were recanalized successfully. Collateral related perforation occurred in three (18.8%) cases with the epicardial collateral as the first choice (compared with the septal collateral group (0), P collaterals. The retrograde approach is an effective technique to recanalize CTO lesions, the septal

  5. Combined-stent covered technique and single covered stent technique for transjugular intrahepatic porto-systemic shunt: a prospective randomized controlled study

    International Nuclear Information System (INIS)

    Wang Changming; Li Xuan; Fu Jun; Lu Xianjun; Luan Jingyuan; Li Tianrun; Zhao Jun; Dong Guoxiang

    2014-01-01

    Objective: To compare the technique of combined stents with that of single stent-graft for the construction of transjugular intrahepatic porto-systemic shunt (TIPS) and to discuss their clinical outcomes. Methods: During the period from April 2011 to Dec. 2012, a total of 30 patients with upper gastrointestinal bleeding due to portal hypertension were admitted to the hospital. TIPS procedure was carried out in all the 30 patients. The patients were randomly allocated into either combined-stent group (n=17) or stent-graft group (control group, n=13) on the basis of a computer-generated randomization sequence. The PSC quality control, the patency rate of portal vein branches and the shunts, the incidence of encephalopathy and the survival rate of the two groups were documented and analyzed. Results: Technical success rate was 100%. After the treatment, in both groups the PSG became significantly lower than the PSG determined before the treatment (P<0.000). According to quality control chart, the of combined stents was superior to stent-graft technique in effectively controlling PSG. Five days after TIPS, the ammonia level in the combined- stent group was significantly decreased (P=0.029), while in the control group the ammonia level showed no significant changes (P=0.065). One patient died shortly after TIPS. The median follow- up time was 181 days. During the follow-up period death occurred in 3 cases in each group. The difference in the survival rate between the two groups was no significant (P=0.906). Of the three patients who developed encephalopathy, two were in the combined-stent group and one was in the control group. After medication the symptoms of encephalopathy were relieved. The patency rate of the shunts was 100% and the re-bleeding rate was 0% for both groups. The patency rate of portal vein branches was significantly higher in the combined-stent group than that in the control group (P=0.039). Conclusion: For the construction of TIPS, the technique of

  6. Encefalopatía hepática secundaria a la existencia de un shunt portosistémico tratada satisfactoriamente mediante radiología intervencionista Hepatic encephalophaty secondary to porto-systemic shunt satisfactorily treated with interventionist radiology

    Directory of Open Access Journals (Sweden)

    L. Crespo

    2007-11-01

    Full Text Available La encefalopatía hepática es un estado reversible de alteración en la función cognitiva, que puede ocurrir en pacientes con enfermedad hepática aguda o crónica o shunts porto-sistémicos, en el que puede aparecer cualquiera de los signos neurológicos o psiquiátricos conocidos. Las sustancias nitrogenadas procedentes de la digestión intestinal alcanzan el cerebro sin la depuración que supone su paso por el hígado, debido a las derivaciones porto-sistémicas, y dan lugar a los signos característicos de la encefalopatía hepática. A continuación presentamos dos casos clínicos de pacientes con shunt porto-sistémicos, diagnosticados de encefalopatía hepática crónica recurrente refractaria al tratamiento médico convencional, tratados satisfactoriamente con embolización de dicho shunt mediante técnicas de radiología intervencionista.Hepatic encephalopathy is a reversible state of altered cognition that may occur in patients with acute or chronic liver disease or porto-systemic shunt, and in which known neurological or psychiatric signs may develop. Nitrogenated substances from intestinal digestion reach the brain without being cleared by their passage through the liver due to the presence of porto-systemic shunt. We report two cases of patients with porto-systemic shunt diagnosed with recurrent chronic hepatic encephalopathy refractory to conventional medical treatment. They were satisfactorily treated with shunt embolization using interventionist radiology techniques.

  7. 12 CFR 263.17 - Collateral attacks on adjudicatory proceeding.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Collateral attacks on adjudicatory proceeding... Collateral attacks on adjudicatory proceeding. If an interlocutory appeal or collateral attack is brought in... shall be excused based on the pendency before any court of any interlocutory appeal or collateral attack. ...

  8. 12 CFR 1780.16 - Collateral attacks on adjudicatory proceeding.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Collateral attacks on adjudicatory proceeding... Rules § 1780.16 Collateral attacks on adjudicatory proceeding. If an interlocutory appeal or collateral... subpart shall be excused based on the pendency before any court of any interlocutory appeal or collateral...

  9. 12 CFR 509.17 - Collateral attacks on adjudicatory proceeding.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Collateral attacks on adjudicatory proceeding....17 Collateral attacks on adjudicatory proceeding. If an interlocutory appeal or collateral attack is... shall be excused based on the pendency before any court of any interlocutory appeal or collateral attack. ...

  10. 12 CFR 950.10 - Collateral valuation; appraisals.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Collateral valuation; appraisals. 950.10...-BALANCE SHEET ITEMS ADVANCES Advances to Members § 950.10 Collateral valuation; appraisals. (a) Collateral valuation. Each Bank shall determine the value of collateral securing the Bank's advances in accordance with...

  11. 29 CFR 20.32 - Liquidation of collateral.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Liquidation of collateral. 20.32 Section 20.32 Labor Office... collateral. An agency holding security or collateral which may be liquidated and the proceeds applied on... demand, unless the cost of disposing of the collateral will be disproportionate to its value or special...

  12. 27 CFR 24.159 - Release of collateral security.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Release of collateral... § 24.159 Release of collateral security. Collateral security pledged and deposited will be released only in accordance with the provisions of 31 CFR part 225. The collateral security will not be released...

  13. 27 CFR 17.104 - Deposit of collateral.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Deposit of collateral. 17... PRODUCTS Bonds and Consents of Sureties § 17.104 Deposit of collateral. Except as otherwise provided by law... as collateral security in lieu of bonds obtained from surety companies. Deposit of collateral...

  14. 12 CFR 615.5060 - Special collateral requirement.

    Science.gov (United States)

    2010-01-01

    ... AFFAIRS, LOAN POLICIES AND OPERATIONS, AND FUNDING OPERATIONS Collateral § 615.5060 Special collateral... be withdrawn from collateral upon the expiration of 1 year from the date of the loan closing, unless... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Special collateral requirement. 615.5060...

  15. 7 CFR 4287.113 - Release of collateral.

    Science.gov (United States)

    2010-01-01

    ... Loans § 4287.113 Release of collateral. (a) All releases of collateral with a value exceeding $100,000... loan. The Agency may, at its discretion, require an appraisal of the remaining collateral in cases... (a) of this section, lenders may, over the life of the loan, release collateral (other than personal...

  16. How Collateral Laws Shape Lending and Sectoral Activity

    OpenAIRE

    Calomiris, Charles W.; Larrain, Mauricio; Liberti, José; Sturgess, Jason

    2015-01-01

    This paper investigates the effect of cross-country differences in collateral laws regarding movable assets on lending and sectoral allocation of resources. Using micro-level loan data for a sample of emerging market countries we show that loan-to-values of loans collateralized with movable assets are on average 21 percentage points higher in countries with strong-collateral laws relative to immovable assets. Further, stronger collateral laws tilt collateral composition away from immovable to...

  17. The collateral circulation of the heart

    Science.gov (United States)

    2013-01-01

    The coronary arteries have been regarded as end arteries for decades. However, there are functionally relevant anastomotic vessels, known as collateral arteries, which interconnect epicardial coronary arteries. These vessels provide an alternative source of blood supply to the myocardium in cases of occlusive coronary artery disease. The relevance of these collateral arteries is a matter of ongoing debate, but increasing evidence indicates a relevant protective role in patients with coronary artery disease. The collateral circulation can be assessed by different methods; the gold standard involves intracoronary pressure measurements. While the first clinical trials to therapeutically induce growth of collateral arteries have been unavailing, recent pilot studies using external counterpulsation or growth factors such as granulocyte colony stimulating factor (G-CSF) have shown promising results. PMID:23735225

  18. 12 CFR 725.19 - Collateral requirements.

    Science.gov (United States)

    2010-01-01

    ... CREDIT UNION ADMINISTRATION CENTRAL LIQUIDITY FACILITY § 725.19 Collateral requirements. (a) Each... applicable Facility advance or Agent loan, or by guarantee of the National Credit Union Share Insurance Fund...

  19. Moral hazard in the credit market when the collateral value is stochastic

    OpenAIRE

    Niinimäki, Juha-Pekka

    2010-01-01

    This theoretical paper explores the effects of costly and non-costly collateral on moral hazard, when collateral value may fluctuate. Given that all collateral is costly, stochastic collateral will entail the same positive incentive effects as nonstochastic collateral, provided the variation in collateral value is modest. If it is large, the incentive effects are smaller under stochastic collateral. With non-costly collateral, stochastic collateral entails positive incentive effects or no eff...

  20. Measuring the quality of eligible collateral

    OpenAIRE

    Lehmbecker, Philipp; Missong, Martin

    2008-01-01

    Recently, the U. S. subprime crisis has shown that a weak collateralization of credits may have massive economic implications, entailing severe perturbations of the international financial system. We focus on central bank lending and try to pin down the quantitative impact of the collateralization of central banks' credits. A questionnaire on national monetary frameworks was used to collect data from central banks. Drawing on these data we derive an index of the quality of eligible assets mea...

  1. Re-interpreting Prominences Classified as Tornadoes

    Science.gov (United States)

    Martin, Sara F.; Venkataramanasastry, Aparna

    2015-04-01

    Some papers in the recent literature identify tornado prominences with barbs of quiescent prominences while papers in the much older historic literature include a second category of tornado prominence that does not correspond to a barb of a quiescent prominence. The latter are described as prominence mass rotating around a nearly vertical axis prior to its eruption and the rotation was verified by spectral measurements. From H alpha Doppler-shifted mass motions recorded at Helio Research or the Dutch Open Telescope, we illustrate how the apparent tornado-like motions, identified with barbs, are illusions in our mind’s eye resulting from poorly resolved counterstreaming threads of mass in the barbs of quiescent prominences. In contrast, we confirm the second category of rotational motion in prominences shortly before and during eruption. In addition, we identify this second category as part of the late phase of a phenomenon called the roll effect in erupting prominences. In these cases, the eruption begins with the sideways rolling of the top of a prominence. As the eruption proceeds the rolling motion propagates down one leg or both legs of the prominence depending on whether the eruption is asymmetric or symmetric respectively. As an asymmetric eruption continues, the longer lasting leg becomes nearly vertical and its rotational motion also continues. If only this phase of the eruption was observed, as in some historic cases, it was called a tornado prominence. However, when we now observe entire eruptions in time-lapse sequences, the similarity to terrestrial tornadoes is lost. We conclude that neither prominence barbs, that give the illusion of rotation, nor the cases of true rotational motion, in the legs of erupting prominences, are usefully described as tornado prominences when the complete prominence structure or complete erupting event is observed.

  2. Axonal collateral-collateral transport of tract tracers in brain neurons: false anterograde labelling and useful tool.

    Science.gov (United States)

    Chen, S; Aston-Jones, G

    1998-02-01

    It is well established that some neuroanatomical tracers may be taken up by local axonal terminals and transported to distant axonal collaterals (e.g., transganglionic transport in dorsal root ganglion cells). However, such collateral-collateral transport of tracers has not been systematically examined in the central nervous system. We addressed this issue with four neuronal tracers--biocytin, biotinylated dextran amine, cholera toxin B subunit, and Phaseolus vulgaris-leucoagglutinin--in the cerebellar cortex. Labelling of distant axonal collaterals in the cerebellar cortex (indication of collateral-collateral transport) was seen after focal iontophoretic microinjections of each of the four tracers. However, collateral-collateral transport properties differed among these tracers. Injection of biocytin or Phaseolus vulgaris-leucoagglutinin in the cerebellar cortex yielded distant collateral labelling only in parallel fibres. In contrast, injection of biotinylated dextran amine or cholera toxin B subunit produced distant collateral labelling of climbing fibres and mossy fibres, as well as parallel fibres. The present study is the first systematic examination of collateral-collateral transport following injection of anterograde tracers in brain. Such collateral-collateral transport may produce false-positive conclusions regarding neural connections when using these tracers for anterograde transport. However, this property may also be used as a tool to determine areas that are innervated by common distant afferents. In addition, these results may indicate a novel mode of chemical communication in the nervous system.

  3. Apparent Solar Tornado-Like Prominences

    Science.gov (United States)

    Panasenco, Olga; Martin, Sara F.; Velli, Marco

    2014-02-01

    Recent high-resolution observations from the Solar Dynamics Observatory (SDO) have reawakened interest in the old and fascinating phenomenon of solar tornado-like prominences. This class of prominences was first introduced by Pettit ( Astrophys. J. 76, 9, 1932), who studied them over many years. Observations of tornado prominences similar to the ones seen by SDO had already been documented by Secchi ( Le Soleil, 1877). High-resolution and high-cadence multiwavelength data obtained by SDO reveal that the tornado-like appearance of these prominences is mainly an illusion due to projection effects. We discuss two different cases where prominences on the limb might appear to have a tornado-like behavior. One case of apparent vortical motions in prominence spines and barbs arises from the (mostly) 2D counterstreaming plasma motion along the prominence spine and barbs together with oscillations along individual threads. The other case of apparent rotational motion is observed in a prominence cavity and results from the 3D plasma motion along the writhed magnetic fields inside and along the prominence cavity as seen projected on the limb. Thus, the "tornado" impression results either from counterstreaming and oscillations or from the projection on the plane of the sky of plasma motion along magnetic-field lines, rather than from a true vortical motion around an (apparent) vertical or horizontal axis. We discuss the link between tornado-like prominences, filament barbs, and photospheric vortices at their base.

  4. Prominence mass supply and the cavity

    Energy Technology Data Exchange (ETDEWEB)

    Schmit, Donald J.; Innes, D. [Max Planck Institute for Solar System Research, D-37191 Katlenburg-Lindau (Germany); Gibson, S. [High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO 80307 (United States); Luna, M. [Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife (Spain); Karpen, J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2013-12-20

    A prevalent but untested paradigm is often used to describe the prominence-cavity system: the cavity is under-dense because it is evacuated by supplying mass to the condensed prominence. The thermal non-equilibrium (TNE) model of prominence formation offers a theoretical framework to predict the thermodynamic evolution of the prominence and the surrounding corona. We examine the evidence for a prominence-cavity connection by comparing the TNE model with diagnostics of dynamic extreme ultraviolet (EUV) emission surrounding the prominence, specifically prominence horns. Horns are correlated extensions of prominence plasma and coronal plasma which appear to connect the prominence and cavity. The TNE model predicts that large-scale brightenings will occur in the Solar Dynamics Observatory Atmospheric Imaging Assembly 171 Å bandpass near the prominence that are associated with the cooling phase of condensation formation. In our simulations, variations in the magnitude of footpoint heating lead to variations in the duration, spatial scale, and temporal offset between emission enhancements in the other EUV bandpasses. While these predictions match well a subset of the horn observations, the range of variations in the observed structures is not captured by the model. We discuss the implications of our one-dimensional loop simulations for the three-dimensional time-averaged equilibrium in the prominence and the cavity. Evidence suggests that horns are likely caused by condensing prominence plasma, but the larger question of whether this process produces a density-depleted cavity requires a more tightly constrained model of heating and better knowledge of the associated magnetic structure.

  5. Prominence Mass Supply and the Cavity

    Science.gov (United States)

    Schmit, Donald J.; Gibson, S.; Luna, M.; Karpen, J.; Innes, D.

    2013-01-01

    A prevalent but untested paradigm is often used to describe the prominence-cavity system; the cavity is under-dense because it it evacuated by supplying mass to the condensed prominence. The thermal non-equilibrium (TNE) model of prominence formation offers a theoretical framework to predict the thermodynamic evolutin of the prominence and the surrounding corona. We examine the evidence for a prominence-cavity connection by comparing the TNE model and diagnostics of dynamic extreme ultraviolet (EUV) emission surrounding the prominence, specifically prominence horns. Horns are correlated extensions of prminence plasma and coronal plasma which appear to connect the prominence and cavity. The TNE model predicts that large-scale brightenings will occur in the Solar Dynamics Observatory Atmospheric Imaging Assembly 171 A badpass near he prominence that are associated with the cooling phase of condensation formation. In our simulations, variations in the magnitude of footpoint heating lead to variations in the duration, spatial scale, and temporal offset between emission enhancements in the other EUV bandpasses. While these predictions match well a subset of the horn observations, the range of variations in the observed structures is not captured by the model. We discuss the implications of one-dimensional loop simulations for the three-dimensional time-averaged equilibrium in the prominence and the cavity. Evidence suggests that horns are likely caused by condensing prominence plasma, but the larger question of whether this process produces a density-depleted cavity requires a more tightly constrained model of heating and better knowledge of the associated magnetic structure.

  6. Collateral pathways in lumbar epidural venography

    International Nuclear Information System (INIS)

    Thijssen, H.O.M.; Ike, B.W.; Chevrot, A.; Bijlsma, R.

    1982-01-01

    Opacification of collateral pathways other than the central channels is very rare in lumbar epidural venography. Two cases of opacification of the inferior mesenteric vein following extravasation of contrast medium at the tip of the lateral sacral vein catheter are reported. One case is presented in which filling of normal parametrial venous plexuses and the left ovarian vein occurred as a consequence of incompetent or absent valves in the internal iliac vein. The literature containing comparable collateral flow patterns in disease is reviewed. The significance of the phlebographic features in our cases is discussed. (orig.)

  7. Treatment of hepatic neoplasm through extrahepatic collaterals

    Energy Technology Data Exchange (ETDEWEB)

    Soo, C.S.; Chuang, V.P.; Wallace, S.; Charnsangavej, C.; Carrasco, H.

    1983-04-01

    Twenty-nine patients with hepatic artery occlusion were treated with additional hepatic infusion or embolization through extrahepatic collaterals. Seventeen courses of hepatic infusion were performed in 13 patients through the inferior pancreaticoduodenal artery, left gastric artery, or right gastric artery. Twenty-five hepatic embolization procedures were performed in 16 patients through the right and left phrenic arteries, left and right gastric arteries, pancreaticoduodenal artery, gastroduodenal artery, or omentoepiploic artery. In one patient gastric ulcers developed following left gastric artery infusion. No complication related to the embolization procedure was observed in the embolization group. The extrahepatic collaterals are important alternative routes for continuous transcatheter management of hepatic neoplasms following hepatic artery occlusion.

  8. Treatment of hepatic neoplasm through extrahepatic collaterals

    International Nuclear Information System (INIS)

    Soo, C.S.; Chuang, V.P.; Wallace, S.; Charnsangavej, C.; Carrasco, H.

    1983-01-01

    Twenty-nine patients with hepatic artery occlusion were treated with additional hepatic infusion or embolization through extrahepatic collaterals. Seventeen courses of hepatic infusion were performed in 13 patients through the inferior pancreaticoduodenal artery, left gastric artery, or right gastric artery. Twenty-five hepatic embolization procedures were performed in 16 patients through the right and left phrenic arteries, left and right gastric arteries, pancreaticoduodenal artery, gastroduodenal artery, or omentoepiploic artery. In one patient gastric ulcers developed following left gastric artery infusion. No complication related to the embolization procedure was observed in the embolization group. The extrahepatic collaterals are important alternative routes for continuous transcatheter management of hepatic neoplasms following hepatic artery occlusion

  9. Collateral and its Substitutes in Emerging Markets' Lending

    OpenAIRE

    Lukas Menkhoff; Doris Neuberger; Ornsiri Rungruxsirivorn

    2011-01-01

    Due to opaque information and weak enforcement in emerging loan markets, the need for collateral is high, whereas borrowers lack adequate assets to pledge as collateral. How is this puzzle solved? We find for a representative sample from Northeast Thailand that indeed most loans do not include any tangible assets as collateral. Instead, lenders enforce collateral-free loans through third-party guarantees and relationship lending, but also through modifying loan terms, such as reducing loan si...

  10. Reexamining the Empirical Relation between Loan Risk and Collateral : The Role of the Economic Characteristics of Collateral

    NARCIS (Netherlands)

    Berger, A.N.; Frame, W.S.; Ioannidou, V.

    2012-01-01

    Abstract: This paper offers a possible explanation for the conflicting results in the literature concerning the empirical relation between collateral and loan risk. We posit that certain economic characteristics of collateral may be associated with the empirical dominance of different

  11. 7 CFR 3.15 - Liquidation of collateral.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Liquidation of collateral. 3.15 Section 3.15... and Compromise of Claims § 3.15 Liquidation of collateral. (a) In accordance with applicable statutes and regulations, agencies may liquidate security or collateral through a sale or a nonjudicial...

  12. 12 CFR 747.17 - Collateral attacks on adjudicatory proceeding.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Collateral attacks on adjudicatory proceeding... INVESTIGATIONS Uniform Rules of Practice and Procedure § 747.17 Collateral attacks on adjudicatory proceeding. If an interlocutory appeal or collateral attack is brought in any court concerning all or any part of an...

  13. 32 CFR 536.51 - Collateral source rule.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Collateral source rule. 536.51 Section 536.51... AGAINST THE UNITED STATES Investigation and Processing of Claims § 536.51 Collateral source rule. Where permitted by applicable state or maritime law, damages recovered from collateral sources are payable under...

  14. 12 CFR 308.17 - Collateral attacks on adjudicatory proceeding.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Collateral attacks on adjudicatory proceeding... PRACTICE RULES OF PRACTICE AND PROCEDURE Uniform Rules of Practice and Procedure § 308.17 Collateral attacks on adjudicatory proceeding. If an interlocutory appeal or collateral attack is brought in any...

  15. 27 CFR 17.114 - Release of collateral.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Release of collateral. 17... PRODUCTS Bonds and Consents of Sureties Termination of Bonds § 17.114 Release of collateral. The release of collateral security pledged and deposited to satisfy the bond requirement of this part is governed by the...

  16. 46 CFR 308.509 - Collateral deposit fund.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Collateral deposit fund. 308.509 Section 308.509... Risk Cargo Insurance Ii-Open Policy War Risk Cargo Insurance § 308.509 Collateral deposit fund. (a) Requirements. An assured electing to use a cash collateral deposit fund pursuant to § 308.507 shall comply with...

  17. 12 CFR 19.17 - Collateral attacks on adjudicatory proceeding.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Collateral attacks on adjudicatory proceeding... OF PRACTICE AND PROCEDURE Uniform Rules of Practice and Procedure § 19.17 Collateral attacks on adjudicatory proceeding. If an interlocutory appeal or collateral attack is brought in any court concerning all...

  18. 41 CFR 105-55.014 - Liquidation of collateral.

    Science.gov (United States)

    2010-07-01

    ... collateral. 105-55.014 Section 105-55.014 Public Contracts and Property Management Federal Property... Administration 55-COLLECTION OF CLAIMS OWED THE UNITED STATES § 105-55.014 Liquidation of collateral. (a) The General Services Administration (GSA) will liquidate security or collateral through the exercise of a...

  19. 48 CFR 48.104-3 - Sharing collateral savings.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Sharing collateral savings... CONTRACT MANAGEMENT VALUE ENGINEERING Policies and Procedures 48.104-3 Sharing collateral savings. (a) The Government shares collateral savings with the contractor, unless the head of the contracting activity has...

  20. 24 CFR 1005.107 - What is eligible collateral?

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false What is eligible collateral? 1005... URBAN DEVELOPMENT LOAN GUARANTEES FOR INDIAN HOUSING § 1005.107 What is eligible collateral? (a) In general. A loan guaranteed under section 184 may be secured by any collateral authorized under and not...

  1. 10 CFR 1015.210 - Liquidation of collateral.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Liquidation of collateral. 1015.210 Section 1015.210... for the Administrative Collection of Claims § 1015.210 Liquidation of collateral. (a) DOE may liquidate security or collateral through the exercise of a power of sale in the security instrument or a...

  2. 26 CFR 403.29 - Deposit of collateral.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Deposit of collateral. 403.29 Section 403.29... ADMINISTRATION DISPOSITION OF SEIZED PERSONAL PROPERTY Seizures and Forfeitures § 403.29 Deposit of collateral... principal by the United States, may be pledged and deposited by claimants as collateral security in lieu of...

  3. 27 CFR 72.25 - Deposit of collateral.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Deposit of collateral. 72... Seizures and Forfeitures § 72.25 Deposit of collateral. (a) Bonds or notes of the United States, or other... be pledged and deposited by claimants as collateral security in lieu of corporate sureties in...

  4. 48 CFR 2448.104-3 - Sharing collateral savings.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Sharing collateral savings... DEVELOPMENT CONTRACT MANAGEMENT VALUE ENGINEERING 2448.104-3 Sharing collateral savings. (a) The authority of the HCA to determine that the cost of calculating and tracking collateral savings will exceed the...

  5. 40 CFR 13.16 - Liquidation of collateral.

    Science.gov (United States)

    2010-07-01

    ... STANDARDS Collection § 13.16 Liquidation of collateral. Where the Administrator holds a security instrument with a power of sale or has physical possession of collateral, he may liquidate the security or... businesses, including liquidation of security or collateral, is not a prerequisite to requiring payment by a...

  6. 22 CFR 213.17 - Liquidation of collateral.

    Science.gov (United States)

    2010-04-01

    ... Liquidation of collateral. Where the CFO holds a security instrument with a power of sale or has physical possession of collateral, he may liquidate the security or collateral and apply the proceeds to the overdue... circumstances require judicial foreclosure. However, collection from other businesses, including liquidation of...

  7. 28 CFR 104.47 - Collateral sources.

    Science.gov (United States)

    2010-07-01

    ... determining the appropriate collateral source offset for future benefit payments, the Special Master may employ an appropriate methodology for determining the present value of such future benefits. In... compensation, including life insurance, pension funds, death benefits programs, and payments by Federal, State...

  8. Collateral Learning and Mathematical Education of Teachers

    Science.gov (United States)

    Abramovich, Sergei

    2012-01-01

    This article explores the notion of collateral learning in the context of classic ideas about the summation of powers of the first "n" counting numbers. Proceeding from the well-known legend about young Gauss, this article demonstrates the value of reflection under the guidance of "the more knowledgeable other" as a pedagogical method of making…

  9. The future of collateral artery research

    NARCIS (Netherlands)

    Hakimzadeh, Nazanin; Verberne, Hein J.; Siebes, Maria; Piek, Jan J.

    2014-01-01

    In the event of obstructive coronary artery disease, collateral arteries have been deemed an alternative blood source to preserve myocardial tissue perfusion and function. Monocytes play an important role in modulating this process, by local secretion of growth factors and extracellular matrix

  10. Trade credit, collateral liquidation and borrowing constraints

    NARCIS (Netherlands)

    Fabbri, D.; Menichini, A.M.C.

    2009-01-01

    The paper proposes a model of collateralized bank and trade credit. Firms use a two-input technology. Assuming that the supplier is better able to extract value from existing assets and has an information advantage over other creditors, the paper derives a series of predictions. (1) Financially

  11. 31 CFR 202.6 - Collateral security.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Collateral security. 202.6 Section 202.6 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE DEPOSITARIES AND FINANCIAL AGENTS OF THE FEDERAL...

  12. 12 CFR 614.4240 - Collateral definitions.

    Science.gov (United States)

    2010-01-01

    ... following definitions shall apply: (a) Abundance of caution, when used to describe decisions to require... income and/or other collateral, absent the real estate, and the decision to extend credit was, in fact... normal consideration for the property sold unaffected by special or creative financing or sales...

  13. TANGLED MAGNETIC FIELDS IN SOLAR PROMINENCES

    International Nuclear Information System (INIS)

    Van Ballegooijen, A. A.; Cranmer, S. R.

    2010-01-01

    Solar prominences are an important tool for studying the structure and evolution of the coronal magnetic field. Here we consider so-called hedgerow prominences, which consist of thin vertical threads. We explore the possibility that such prominences are supported by tangled magnetic fields. A variety of different approaches are used. First, the dynamics of plasma within a tangled field is considered. We find that the contorted shape of the flux tubes significantly reduces the flow velocity compared to the supersonic free fall that would occur in a straight vertical tube. Second, linear force-free models of tangled fields are developed, and the elastic response of such fields to gravitational forces is considered. We demonstrate that the prominence plasma can be supported by the magnetic pressure of a tangled field that pervades not only the observed dense threads but also their local surroundings. Tangled fields with field strengths of about 10 G are able to support prominence threads with observed hydrogen density of the order of 10 11 cm -3 . Finally, we suggest that the observed vertical threads are the result of Rayleigh-Taylor instability. Simulations of the density distribution within a prominence thread indicate that the peak density is much larger than the average density. We conclude that tangled fields provide a viable mechanism for magnetic support of hedgerow prominences.

  14. Magnetohydrodynamic (MHD) simulation of solar prominence formation

    International Nuclear Information System (INIS)

    Bao, J.

    1987-01-01

    Formation of Kippenhahn-Schluter type solar prominences by chromospheric mass injection is studied via numerical simulation. The numerical model is based on a two-dimensional, time-dependent magnetohydrodynamic (MHD) theory. In addition, an analysis of gravitational thermal MHD instabilities related to condensation is performed by using the small-perturbation method. The conclusions are: (1) Both quiescent and active-region prominences can be formed by chromospheric mass injection, provided certain optimum conditions are satisfied. (2) Quiescent prominences cannot be formed without condensation, though enough mass is supplied from chromosphere. The mass of a quiescent prominence is composed of both the mass injected from the chromosphere and the mass condensed from the corona. On the other hand, condensation is not important to active region prominence formation. (3) In addition to channeling and supporting effects, the magnetic field plays another important role, i.e. containing the prominence material. (4) In the model cases, prominences are supported by the Lorentz force, the gas-pressure gradient and the mass-injection momentum. (5) Due to gravity, more MHD condensation instability modes appear in addition to the basic condensation mode

  15. Nonlinear MHD Waves in a Prominence Foot

    Science.gov (United States)

    Ofman, L.; Knizhnik, K.; Kucera, T.; Schmieder, B.

    2015-11-01

    We study nonlinear waves in a prominence foot using a 2.5D MHD model motivated by recent high-resolution observations with Hinode/Solar Optical Telescope in Ca ii emission of a prominence on 2012 October 10 showing highly dynamic small-scale motions in the prominence material. Observations of Hα intensities and of Doppler shifts show similar propagating fluctuations. However, the optically thick nature of the emission lines inhibits a unique quantitative interpretation in terms of density. Nevertheless, we find evidence of nonlinear wave activity in the prominence foot by examining the relative magnitude of the fluctuation intensity (δI/I ˜ δn/n). The waves are evident as significant density fluctuations that vary with height and apparently travel upward from the chromosphere into the prominence material with quasi-periodic fluctuations with a typical period in the range of 5-11 minutes and wavelengths <2000 km. Recent Doppler shift observations show the transverse displacement of the propagating waves. The magnetic field was measured with the THEMIS instrument and was found to be 5-14 G. For the typical prominence density the corresponding fast magnetosonic speed is ˜20 km s-1, in qualitative agreement with the propagation speed of the detected waves. The 2.5D MHD numerical model is constrained with the typical parameters of the prominence waves seen in observations. Our numerical results reproduce the nonlinear fast magnetosonic waves and provide strong support for the presence of these waves in the prominence foot. We also explore gravitational MHD oscillations of the heavy prominence foot material supported by dipped magnetic field structure.

  16. NONLINEAR MHD WAVES IN A PROMINENCE FOOT

    Energy Technology Data Exchange (ETDEWEB)

    Ofman, L. [Catholic University of America, Washington, DC 20064 (United States); Knizhnik, K.; Kucera, T. [NASA Goddard Space Flight Center, Code 671, Greenbelt, MD 20771 (United States); Schmieder, B. [LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris-Diderot, Sorbonne Paris Cit, 5 place Jules Janssen, F-92195 Meudon (France)

    2015-11-10

    We study nonlinear waves in a prominence foot using a 2.5D MHD model motivated by recent high-resolution observations with Hinode/Solar Optical Telescope in Ca ii emission of a prominence on 2012 October 10 showing highly dynamic small-scale motions in the prominence material. Observations of Hα intensities and of Doppler shifts show similar propagating fluctuations. However, the optically thick nature of the emission lines inhibits a unique quantitative interpretation in terms of density. Nevertheless, we find evidence of nonlinear wave activity in the prominence foot by examining the relative magnitude of the fluctuation intensity (δI/I ∼ δn/n). The waves are evident as significant density fluctuations that vary with height and apparently travel upward from the chromosphere into the prominence material with quasi-periodic fluctuations with a typical period in the range of 5–11 minutes and wavelengths <2000 km. Recent Doppler shift observations show the transverse displacement of the propagating waves. The magnetic field was measured with the THEMIS instrument and was found to be 5–14 G. For the typical prominence density the corresponding fast magnetosonic speed is ∼20 km s{sup −1}, in qualitative agreement with the propagation speed of the detected waves. The 2.5D MHD numerical model is constrained with the typical parameters of the prominence waves seen in observations. Our numerical results reproduce the nonlinear fast magnetosonic waves and provide strong support for the presence of these waves in the prominence foot. We also explore gravitational MHD oscillations of the heavy prominence foot material supported by dipped magnetic field structure.

  17. Collateral Circulation in Chronic Total Occlusions - An Interventional Perspective

    Science.gov (United States)

    Choo, Gim-Hooi

    2015-01-01

    Human coronary collaterals are inter-coronary communications that are believed to be present from birth. In the presence of chronic total occlusions, recruitment of flow via these collateral anastomoses to the arterial segment distal to occlusion provide an alternative source of blood flow to the myocardial segment at risk. This mitigates the ischemic injury. Clinical outcome of coronary occlusion ie. severity of myocardial infarction/ischemia, impairment of cardiac function and possibly survival depends not only on the acuity of the occlusion, extent of jeopardized myocardium, duration of ischemia but also to the adequacy of collateral circulation. Adequacy of collateral circulation can be assessed by various methods. These coronary collateral channels have been used successfully as a retrograde access route for percutaneous recanalization of chronic total occlusions. Factors that promote angiogenesis and further collateral remodeling ie. arteriogenesis have been identified. Promotion of collateral growth as a therapeutic target in patients with no suitable revascularization option is an exciting proposal.

  18. Collateral Circulation in Chronic Total Occlusions - an interventional perspective.

    Science.gov (United States)

    Choo, Gim-Hooi

    2015-09-09

    Human coronary collaterals are inter-coronary communications that are believed to be present from birth. In the presence of chronic total occlusions, recruitment of flow via these collateral anastomoses to the arterial segment distal to occlusion provide an alternative source of blood flow to the myocardial segment at risk. This mitigates the ischemic injury. Clinical outcome of coronary occlusion ie. severity of myocardial infarction/ischemia, impairment of cardiac function and possibly survival depends not only on the acuity of the occlusion, extent of jeopardized myocardium, duration of ischemia but also to the adequacy of collateral circulation. Adequacy of collateral circulation can be assessed by various methods. These coronary collateral channels have been used successfully as a retrograde access route for percutaneous recanalization of chronic total occlusions. Factors that promote angiogenesis and further collateral remodeling ie. arteriogenesis have been identified. Promotion of collateral growth as a therapeutic target in patients with no suitable revascularization option is an exciting proposal.

  19. Topic prominence in Chinese EFL learners’ interlanguage

    Directory of Open Access Journals (Sweden)

    Shaopeng Li

    2014-01-01

    Full Text Available The present study aims to investigate the general characteristics of topicprominent typological interlanguage development of Chinese learners of English in terms of acquiring subject-prominent English structures from a discourse perspective. Topic structures mainly appear in Chinese discourse in the form of topic chains (Wang, 2002; 2004. The research target are the topic chain, which is the main topic-prominent structure in Chinese discourse, and zero anaphora, which is the most common topic anaphora in the topic chain. Two important findings emerged from the present study. First, the characteristics of Chinese topic chains are transferrable to the interlanguage of Chinese EFL learners, thus resulting in overgeneralization of the zero anaphora. Second, the interlanguage discourse of Chinese EFL learners reflects a change of the second language acquisition process from topic-prominence to subject-prominence, thus lending support to the discourse transfer hypothesis.

  20. EUV observations of quiescent prominences from Skylab

    International Nuclear Information System (INIS)

    Moe, O.K.

    1979-01-01

    The authors report measurements of line intensities and line widths for three quiescent prominences observed with the Naval Research Laboratory slit spectrograph on ATM/Skylab. The wavelengths of the observed lines cover the range 1175 A to 1960 A. The measured intensities have been calibrated to within approximately a factor 2 and are average intensities over a 2 arc sec by 60 arc set slit. Nonthermal velocities are derived from the measured line widths. The nonthermal velocity is found to increase with temperature in the prominence transition zone. Electron densities and pressures are derived from density sensitive line ratios. Electron pressures for two of the prominences are found to lie in the range 0.04-0.08 dyn cm -2 , while values for the third and most intense and active of the three prominences are in the range 0.07-0.22 dyn cm -2 . (Auth.)

  1. Acquired portosystemic collaterals: anatomy and imaging

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Andrea Farias de Melo; Mota Junior, Americo, E-mail: andreafariasm@gmail.com [Instituto de Medicina Integral Professor Fernando Figueira de Pernambuco (IMIP), Recife, PE (Brazil); Chagas-Neto, Francisco Abaete [Universidade de Fortaleza (UNIFOR), Fortaleza, CE (Brazil); Teixeira, Sara Reis; Elias Junior, Jorge; Muglia, Valdair Francisco [Universidade de Sao Paulo (FMRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina

    2016-07-15

    Portosystemic shunts are enlarged vessels that form collateral pathological pathways between the splanchnic circulation and the systemic circulation. Although their causes are multifactorial, portosystemic shunts all have one mechanism in common - increased portal venous pressure, which diverts the blood flow from the gastrointestinal tract to the systemic circulation. Congenital and acquired collateral pathways have both been described in the literature. The aim of this pictorial essay was to discuss the distinct anatomic and imaging features of portosystemic shunts, as well as to provide a robust method of differentiating between acquired portosystemic shunts and similar pathologies, through the use of illustrations and schematic drawings. Imaging of portosystemic shunts provides subclinical markers of increased portal venous pressure. Therefore, radiologists play a crucial role in the identification of portosystemic shunts. Early detection of portosystemic shunts can allow ample time to perform endovascular shunt operations, which can relieve portal hypertension and prevent acute or chronic complications in at-risk patient populations. (author)

  2. Acquired portosystemic collaterals: anatomy and imaging

    International Nuclear Information System (INIS)

    Leite, Andrea Farias de Melo; Mota Junior, Americo; Chagas-Neto, Francisco Abaete; Teixeira, Sara Reis; Elias Junior, Jorge; Muglia, Valdair Francisco

    2016-01-01

    Portosystemic shunts are enlarged vessels that form collateral pathological pathways between the splanchnic circulation and the systemic circulation. Although their causes are multifactorial, portosystemic shunts all have one mechanism in common - increased portal venous pressure, which diverts the blood flow from the gastrointestinal tract to the systemic circulation. Congenital and acquired collateral pathways have both been described in the literature. The aim of this pictorial essay was to discuss the distinct anatomic and imaging features of portosystemic shunts, as well as to provide a robust method of differentiating between acquired portosystemic shunts and similar pathologies, through the use of illustrations and schematic drawings. Imaging of portosystemic shunts provides subclinical markers of increased portal venous pressure. Therefore, radiologists play a crucial role in the identification of portosystemic shunts. Early detection of portosystemic shunts can allow ample time to perform endovascular shunt operations, which can relieve portal hypertension and prevent acute or chronic complications in at-risk patient populations. (author)

  3. Collateral flow after extracorporeal membrane oxygenation

    International Nuclear Information System (INIS)

    Smith, A.S.; Wiznitzer, M.; Haacke, E.M.

    1990-01-01

    MR angiography was used to evaluate collateral flow after extracorporal membrane oxygenation (ECMO) in patients with permanent ligation of the right common carotid artery (RCCA). One year after ECMO, MR angiography of the cerebral circulation was performed in 11 survivors and MR angiography of the neck in seven. The diameters of the left common carotid (LCCA) and vertebral (Vert) arteries in the neck and of the basilar (Bas) and internal carotid arteries in the head were measured. Ratios of the artery diameters were compared with those of seven children (aged 6 months - 17 years) who had normal MR angiographic and brain MR imaging studies. Compared with carotid artery diameter, the ECMO population had proportionately larger vertebral (RVert/LCCA, -0.82 ± 0.12 vs 0.56 ± 0.20 [<.02], LVert/LCCA, -0.86 ± 0.15 vs 0.67 ± 0.05 [P < .02] and basilar artery diameters (LICA/Bas, -0.91 ± 0.15 vs 1.49 ± 0.48 [p < .003]) than did control subjects. Ratios in five children with enlarged RPComA after ECMO were not significantly different from those in controls. The RICA was present and smaller than the LICA in the ECMO population, but not in control subjects (RICA/LICA, -0.75 ± 0.06 vs 0.91 ± 0.23 [p < .05]). Increased vertebral and basilar artery flow is a response to RCCA ligation in the neonate and is independent of RPComA collateral flow. This suggests the presence of more extensive parenchymal collaterals from posterior cerebral arteries, from the vertebrobasilar circulation to the external carotid artery or other collaterals. Consequently, later abnormalities of vertebrobasilar flow might adversely affect right hemispheric function in this children

  4. Automated image based prominent nucleoli detection.

    Science.gov (United States)

    Yap, Choon K; Kalaw, Emarene M; Singh, Malay; Chong, Kian T; Giron, Danilo M; Huang, Chao-Hui; Cheng, Li; Law, Yan N; Lee, Hwee Kuan

    2015-01-01

    Nucleolar changes in cancer cells are one of the cytologic features important to the tumor pathologist in cancer assessments of tissue biopsies. However, inter-observer variability and the manual approach to this work hamper the accuracy of the assessment by pathologists. In this paper, we propose a computational method for prominent nucleoli pattern detection. Thirty-five hematoxylin and eosin stained images were acquired from prostate cancer, breast cancer, renal clear cell cancer and renal papillary cell cancer tissues. Prostate cancer images were used for the development of a computer-based automated prominent nucleoli pattern detector built on a cascade farm. An ensemble of approximately 1000 cascades was constructed by permuting different combinations of classifiers such as support vector machines, eXclusive component analysis, boosting, and logistic regression. The output of cascades was then combined using the RankBoost algorithm. The output of our prominent nucleoli pattern detector is a ranked set of detected image patches of patterns of prominent nucleoli. The mean number of detected prominent nucleoli patterns in the top 100 ranked detected objects was 58 in the prostate cancer dataset, 68 in the breast cancer dataset, 86 in the renal clear cell cancer dataset, and 76 in the renal papillary cell cancer dataset. The proposed cascade farm performs twice as good as the use of a single cascade proposed in the seminal paper by Viola and Jones. For comparison, a naive algorithm that randomly chooses a pixel as a nucleoli pattern would detect five correct patterns in the first 100 ranked objects. Detection of sparse nucleoli patterns in a large background of highly variable tissue patterns is a difficult challenge our method has overcome. This study developed an accurate prominent nucleoli pattern detector with the potential to be used in the clinical settings.

  5. Automated image based prominent nucleoli detection

    Directory of Open Access Journals (Sweden)

    Choon K Yap

    2015-01-01

    Full Text Available Introduction: Nucleolar changes in cancer cells are one of the cytologic features important to the tumor pathologist in cancer assessments of tissue biopsies. However, inter-observer variability and the manual approach to this work hamper the accuracy of the assessment by pathologists. In this paper, we propose a computational method for prominent nucleoli pattern detection. Materials and Methods: Thirty-five hematoxylin and eosin stained images were acquired from prostate cancer, breast cancer, renal clear cell cancer and renal papillary cell cancer tissues. Prostate cancer images were used for the development of a computer-based automated prominent nucleoli pattern detector built on a cascade farm. An ensemble of approximately 1000 cascades was constructed by permuting different combinations of classifiers such as support vector machines, eXclusive component analysis, boosting, and logistic regression. The output of cascades was then combined using the RankBoost algorithm. The output of our prominent nucleoli pattern detector is a ranked set of detected image patches of patterns of prominent nucleoli. Results: The mean number of detected prominent nucleoli patterns in the top 100 ranked detected objects was 58 in the prostate cancer dataset, 68 in the breast cancer dataset, 86 in the renal clear cell cancer dataset, and 76 in the renal papillary cell cancer dataset. The proposed cascade farm performs twice as good as the use of a single cascade proposed in the seminal paper by Viola and Jones. For comparison, a naive algorithm that randomly chooses a pixel as a nucleoli pattern would detect five correct patterns in the first 100 ranked objects. Conclusions: Detection of sparse nucleoli patterns in a large background of highly variable tissue patterns is a difficult challenge our method has overcome. This study developed an accurate prominent nucleoli pattern detector with the potential to be used in the clinical settings.

  6. Internal Carotid Artery Stenosis and Collateral Recruitment in Stroke Patients.

    Science.gov (United States)

    Dankbaar, Jan W; Kerckhoffs, Kelly G P; Horsch, Alexander D; van der Schaaf, Irene C; Kappelle, L Jaap; Velthuis, Birgitta K

    2017-04-24

    Leptomeningeal collaterals improve outcome in stroke patients. There is great individual variability in their extent. Internal carotid artery (ICA) stenosis may lead to more extensive recruitment of leptomeningeal collaterals. The purpose of this study was to evaluate the association of pre-existing ICA stenosis with leptomeningeal collateral filling visualized with computed tomography perfusion (CTP). From a prospective acute ischemic stroke cohort, patients were included with an M1 middle cerebral artery (MCA) occlusion and absent ipsilateral, extracranial ICA occlusion. ICA stenosis was determined on admission CT angiography (CTA). Leptomeningeal collaterals were graded as good (>50%) or poor (≤50%) collateral filling in the affected MCA territory on CTP-derived vessel images of the admission scan. The association between ipsilateral ICA stenosis ≥70% and extent of collateral filling was analyzed using logistic regression. In a multivariable analysis the odds ratio (OR) of ICA stenosis ≥70% was adjusted for complete circle of Willis, gender and age. We included 188 patients in our analyses, 50 (26.6%) patients were classified as having poor collateral filling and 138 (73.4%) as good. Of the patients 4 with poor collateral filling had an ICA stenosis ≥70% and 14 with good collateral filling. Unadjusted and adjusted ORs of ICA stenosis ≥70% for good collateral filling were 1.30 (0.41-4.15) and 2.67 (0.81-8.77), respectively. Patients with poor collateral filling had a significantly worse outcome (90-day modified Rankin scale 3-6; 80% versus 52%, p = 0.001). No association was found between pre-existing ICA stenosis and extent of CTP derived collateral filling in patients with an M1 occlusion.

  7. Collateral veins in inferior caval vein occlusion demonstrated via CT

    International Nuclear Information System (INIS)

    Lien, H.H.; Lund, G.

    1983-01-01

    CT-scans of 12 patients with tumour-induced occlusion of the inferior vena cava were studied with regard to collateral veins. A comparison was performed with findings at phlebography in 10 patients and at autopsy in 2. The site and appearance of the main collateral pathway are presented. A close study of vascular structures renders useful information on collateral circulation in occlusion of the inferior vena cava. (orig.)

  8. Magnetohydrodynamic interpretation of the motion of prominences

    International Nuclear Information System (INIS)

    Sakurai, Takashi

    1976-01-01

    We study three types of prominence eruptions, which we will call the arch type, the loop type, and the gigantic arch type, respectively, from their shapes. If we regard the prominence as a magnetic flux tube, the onset of its ascending motion can be interpreted as the motion due to the screw-mode instability, which is the most unstable mode of instabilities of a magnetofluid column (pinch). The growth rate of this mode is evaluated and is shown to be consistent with the time scale of the initial stage of the eruption. In order to study the nonlinear stage of the instability, we propose a method of numerical calculation based on a variational technique known as Ritz's method. The result shows that the characteristic motion of the arch-, loop-, and gigantic arch-type eruptions may be reproduced by perturbing a model sequence with decreasing pitch angles of the unperturbed helical magnetic field lines. This conclusion seems to be supported by the pitch angles of observed threads in each type of prominence and also by the fact that the observed time profiles of the rising velocity of the prominences of each type agree well with those predicted from model calculations. (auth.)

  9. Topic Prominence in Chinese EFL Learners' Interlanguage

    Science.gov (United States)

    Li, Shaopeng; Yang, Lianrui

    2014-01-01

    The present study aims to investigate the general characteristics of topicprominent typological interlanguage development of Chinese learners of English in terms of acquiring subject-prominent English structures from a discourse perspective. Topic structures mainly appear in Chinese discourse in the form of topic chains (Wang, 2002; 2004). The…

  10. Coronary collateral vessels in patients with previous myocardial infarction

    International Nuclear Information System (INIS)

    Nakatsuka, M.; Matsuda, Y.; Ozaki, M.

    1987-01-01

    To assess the degree of collateral vessels after myocardial infarction, coronary angiograms, left ventriculograms, and exercise thallium-201 myocardial scintigrams of 36 patients with previous myocardial infarction were reviewed. All 36 patients had total occlusion of infarct-related coronary artery and no more than 70% stenosis in other coronary arteries. In 19 of 36 patients with transient reduction of thallium-201 uptake in the infarcted area during exercise (Group A), good collaterals were observed in 10 patients, intermediate collaterals in 7 patients, and poor collaterals in 2 patients. In 17 of 36 patients without transient reduction of thallium-201 uptake in the infarcted area during exercise (Group B), good collaterals were seen in 2 patients, intermediate collaterals in 7 patients, and poor collaterals in 8 patients (p less than 0.025). Left ventricular contractions in the infarcted area were normal or hypokinetic in 10 patients and akinetic or dyskinetic in 9 patients in Group A. In Group B, 1 patient had hypokinetic contraction and 16 patients had akinetic or dyskinetic contraction (p less than 0.005). Thus, patients with transient reduction of thallium-201 uptake in the infarcted area during exercise had well developed collaterals and preserved left ventricular contraction, compared to those in patients without transient reduction of thallium-201 uptake in the infarcted area during exercise. These results suggest that the presence of viable myocardium in the infarcted area might be related to the degree of collateral vessels

  11. CT imaging of collaterals in stenoses of large mediastinal veins

    International Nuclear Information System (INIS)

    Goerich, J.; Flentje, M.; Gueckel, F.; Beyer-Enke, S.A.; Kaick, G. van; Heidelberg Univ.

    1988-01-01

    Scans of angio-computed tomography (CT) of 53 patients suffering from mediastinal space-occupying growths were reviewed: 16 patients showed stenosis of mediastinal veins with demonstration of subcutaneous venous channels, 17 showed an obstruction without collateral pathways and 20 patients had normal mediastinal vessels. Two thirds of the cases with external vein compression were caused by bronchogenic carcinoma. The degree of obstruction in patients showing collateral circulation was between 70 and 100 percent and significantly greater than in patients without collaterals (40%). The most important collaterals bypassing the upper mediastinal veins are discussed. (orig.) [de

  12. Pleiotrophin levels are associated with improved coronary collateral circulation.

    Science.gov (United States)

    Türker Duyuler, Pinar; Duyuler, Serkan; Gök, Murat; Kundi, Harun; Topçuoğlu, Canan; Güray, Ümit

    2018-01-01

    Elucidation of the underlying mechanisms of angiogenesis and arteriogenesis in coronary collateral formation is necessary for new therapies. Pleiotrophin is a secreted multifunctional cytokine and associated with the formation of functional cardiovascular neovascularization in a series of experimental animal models. We aimed to evaluate the serum levels of pleiotrophin in patients with chronic total coronary artery occlusion and poor or good collateral development. We included 88 consecutive patients (mean age of the entire population: 63.7±12.1 years, 68 male patients) with stable angina pectoris who underwent coronary angiography and had chronic total occlusion in at least one major coronary artery. Collateral grading was performed according to the Rentrop classification. After grading, patients were divided into poor collateral circulation (Rentrop grade 0 and 1) and good collateral circulation (Rentrop grades 2 and 3) groups. Serum pleiotrophin levels were measured using a commercial human ELISA kit. Fifty-eight patients had good and 30 patients had poor coronary collaterals. The good collateral group had higher serum pleiotrophin levels than the poor collateral group (690.1±187.9 vs. 415.3±165.9 ng/ml, Pcollateral development (odds ratio: 1.007; confidence interval: 1.003-1.012; P=0.002). This study showed that increased serum pleiotrophin levels are associated with better developed coronary collateral circulation. Further studies are needed to better understand the relationship.

  13. Documenting and automating collateral evolutions in Linux device drivers

    DEFF Research Database (Denmark)

    Padioleau, Yoann; Hansen, René Rydhof; Lawall, Julia

    2008-01-01

    . Manually performing such collateral evolutions is time-consuming and unreliable, and has lead to errors when modifications have not been done consistently. In this paper, we present an automatic program transformation tool, Coccinelle, for documenting and automating device driver collateral evolutions...... programmer. We have evaluated our approach on 62 representative collateral evolutions that were previously performed manually in Linux 2.5 and 2.6. On a test suite of over 5800 relevant driver files, the semantic patches for these collateral evolutions update over 93% of the files completely...

  14. The human coronary collateral circulation: development and clinical importance.

    Science.gov (United States)

    Seiler, Christian; Stoller, Michael; Pitt, Bertram; Meier, Pascal

    2013-09-01

    Coronary collaterals are an alternative source of blood supply to myocardium jeopardized by ischaemia. In comparison with other species, the human coronary collateral circulation is very well developed. Among individuals without coronary artery disease (CAD), there are preformed collateral arteries preventing myocardial ischaemia during a brief vascular occlusion in 20-25%. Determinants of such anastomoses are low heart rate and the absence of systemic arterial hypertension. In patients with CAD, collateral arteries preventing myocardial ischaemia during a brief occlusion are present in every third individual. Collateral flow sufficient to prevent myocardial ischaemia during coronary occlusion amounts to one-fifth to one-fourth the normal flow through the open vessel. Myocardial infarct size, the most important prognostic determinant after such an event, is the product of coronary artery occlusion time, area at risk for infarction, and the inverse of collateral supply. Well-developed coronary collateral arteries in patients with CAD mitigate myocardial infarcts and improve survival. Approximately one-fifth of patients with CAD cannot be revascularized by percutaneous coronary intervention or coronary artery bypass grafting. Therapeutic promotion of collateral growth is a valuable treatment strategy in those patients. It should aim at growth of large conductive collateral arteries (arteriogenesis). Potential arteriogenic approaches include the treatment with granulocyte colony-stimulating factor, physical exercise training, and external counterpulsation.

  15. PROMINENCE ACTIVATION BY CORONAL FAST MODE SHOCK

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Takuya [Department of Astronomy, Kyoto University, Sakyo, Kyoto, 606-8502 (Japan); Asai, Ayumi [Unit of Synergetic Studies for Space, Kyoto University, Yamashina, Kyoto 607-8471 (Japan); Shibata, Kazunari, E-mail: takahashi@kwasan.kyoto-u.ac.jp [Kwasan and Hida Observatories, Kyoto University, Yamashina, Kyoto 607-8471 (Japan)

    2015-03-01

    An X5.4 class flare occurred in active region NOAA11429 on 2012 March 7. The flare was associated with a very fast coronal mass ejection (CME) with a velocity of over 2500 km s{sup −1}. In the images taken with the Solar Terrestrial Relations Observatory-B/COR1, a dome-like disturbance was seen to detach from an expanding CME bubble and propagated further. A Type-II radio burst was also observed at the same time. On the other hand, in extreme ultraviolet images obtained by the Solar Dynamic Observatory/Atmospheric Imaging Assembly (AIA), the expanding dome-like structure and its footprint propagating to the north were observed. The footprint propagated with an average speed of about 670 km s{sup −1} and hit a prominence located at the north pole and activated it. During the activation, the prominence was strongly brightened. On the basis of some observational evidence, we concluded that the footprint in AIA images and the ones in COR1 images are the same, that is, the MHD fast mode shock front. With the help of a linear theory, the fast mode Mach number of the coronal shock is estimated to be between 1.11 and 1.29 using the initial velocity of the activated prominence. Also, the plasma compression ratio of the shock is enhanced to be between 1.18 and 2.11 in the prominence material, which we consider to be the reason for the strong brightening of the activated prominence. The applicability of linear theory to the shock problem is tested with a nonlinear MHD simulation.

  16. Multispacecraft observations of a prominence eruption

    Directory of Open Access Journals (Sweden)

    A. Bemporad

    2009-10-01

    Full Text Available On 9 May 2007 a prominence eruption occurred at the West limb. Remarkably, the event was observed by the STEREO/EUVI telescopes and by the HINODE/EIS and SOHO/UVCS spectrometers. We present results from all these instruments. High-cadence (~37 s data from STEREO/EUVI A and B in the He II λ304 line were used to study the 3-D shape and expansion of the prominence. The high spatial resolution EUVI images (~1.5"/pixel have been used to infer via triangulation the 3-D shape and orientation of the prominence 12 min after the eruption onset. At this time the prominence has mainly the shape of a "hook" highly inclined southward, has an average thickness of 0.068 R⊙, a length of 0.43 R⊙ and lies, in first approximation, on a plane. Hence, the prominence is mainly a 2-D structure and there is no evidence for a twisted flux rope configuration. HINODE/EIS was scanning with the 2" slit the region where the filament erupted. The EIS spectra show during the eruption remarkable non-thermal broadening (up to ~100 km s−1 in the region crossed by the filament in spectral lines emitted at different temperatures, possibly with differences among lines from higher Fe ionization stages. The CME was also observed by the SOHO/UVCS instrument: the spectrograph slit was centered at 1.7 R⊙, at a latitude of 5° SW and recorded a sudden increase in the O VI λλ1032–1037 and Si XII λ520 spectral line intensities, representative of the CME front transit.

  17. Reexamining the Empirical Relation between Loan Risk and Collateral : The Role of the Economic Characteristics of Collateral

    OpenAIRE

    Berger, A.N.; Frame, W.S.; Ioannidou, V.

    2012-01-01

    Abstract: This paper offers a possible explanation for the conflicting results in the literature concerning the empirical relation between collateral and loan risk. We posit that certain economic characteristics of collateral may be associated with the empirical dominance of different risk-collateral channels implied by economic theory, namely the “lender selection,” “borrower selection,” “risk-shifting,” and “loss mitigation” channels. Each of these four channels has different predictions re...

  18. Reexamining the empirical relation between loan risk and collateral:the roles of collateral liquidity and types

    OpenAIRE

    Berger, Allen N.; Frame, W. Scott; Ioannidou, Vasso

    2016-01-01

    This paper offers a possible explanation for the conflicting results in the literature concerning the empirical relation between collateral and loan risk. We posit that differences in collateral characteristics, such as liquidity, may be associated with the empirical dominance of different risk-collateral relations implied by economic theory. Using credit registry data and a novel identification strategy to control for borrower and lender selection effects allows us to differentiate between t...

  19. Clinical, angiographic and hemodynamic predictors of recruitable collateral flow assessed during balloon angioplasty coronary occlusion

    NARCIS (Netherlands)

    Piek, J. J.; van Liebergen, R. A.; Koch, K. T.; Peters, R. J.; David, G. K.

    1997-01-01

    We sought to determine the predictive value of factors influencing coronary collateral vascular responses in humans. There is limited information on the factors responsible for coronary collateral vascular development, despite the protective effect of collateral vessels in ischemic syndromes.

  20. Determinants of leptomeningeal collateral flow in stroke patients with a middle cerebral artery occlusion

    NARCIS (Netherlands)

    van Seeters, Tom; Biessels, Geert Jan; Kappelle, L. Jaap; van der Graaf, Yolanda; Velthuis, Birgitta K.

    2016-01-01

    INTRODUCTION: Poor leptomeningeal collateral flow is related to worse clinical outcome in acute ischemic stroke, but the factors that determine leptomeningeal collateral patency are largely unknown. We explored the determinants of leptomeningeal collateral flow and assessed their effect on the

  1. Collateral flow predicts outcome after basilar artery occlusion : The posterior circulation collateral score

    NARCIS (Netherlands)

    van der Hoeven, Erik J R J; McVerry, Ferghal; Vos, Jan Albert; Algra, Ale; Puetz, Volker; Kappelle, L. Jaap; Schonewille, Wouter J.

    2016-01-01

    BACKGROUND AND AIM: Our aim was to assess the prognostic value of a semiquantitative computed tomography angiography-based grading system, for the prediction of outcome in patients with acute basilar artery occlusion, based on the presence of potential collateral pathways on computed tomography

  2. Transvenous closure of large aortopulmonary collateral

    Directory of Open Access Journals (Sweden)

    Parag W Barwad

    2014-01-01

    Full Text Available Aortopulmonary collaterals (APCs are occluded either preoperatively or at the time of cardiac surgery in patients with pulmonary atresia and ventricular septal defect (PAVSD. If left untreated, APCs are an important cause of deterioration in the early postoperative period. We present here an unusual case with a large residual APC causing refractory low-output state in the early postoperative period. Usual arterial approach failed due to extensive angulation with ostial narrowing. The large residual APC was successfully closed with an Amplatzer duct occluder (ADO device delivered through the transvenous route.

  3. Mortgage Finance and Security of Collateral

    DEFF Research Database (Denmark)

    Haldrup, Karin

    2011-01-01

    Developing economies face a gigantic lack of financing for urbanization due to the absence of formal and transparent property markets. The paper discuss the interference between mortgage finance and collateral security by using the Danish mortgage financing model as an example, because of its 200...... years long history, and because the system is recommended as an option in emerging markets and as a possible model for remedying failures in mature housing finance markets. It is suggested that development policies in land administration need to be revised in order to support a widening of credit...

  4. Aesthetic Refinements in Patients with Prominent Eyes.

    Science.gov (United States)

    Richter, Dirk F; Schwaiger, Nina; Wiedner, Maria

    2015-12-01

    The treatment of prominent eyes is still a challenging task. As well as the surgery, proper preoperative diagnosis differentiating between patients with and without Graves ophthalmopathy plays an important role. In functionally asymptomatic patients with Graves disease suffering from the aesthetic impairment of prominent eyes, the transpalpebral decompression by intraorbital fat removal technique has been proved to be reliable, effective, safe, and easily performed by a trained and experienced oculoplastic surgeon. This technique provides long-lasting results, leading to improvement not only in visual function but also in personal well-being and in the patient's social life, with a high benefit-to-risk ratio. The most powerful tool to treat the lower lid deformity and malar bags in patients without Graves disease is the subperiosteal midface lift. It shortens the lid-cheek junction and blends the retaining periorbital ligaments. Furthermore, it adds volume to the lower lid and gives a stable support. By the nature of the procedure, it also turns a negative into a positive vector. In experienced hands, Olivari's orbital decompression and Hester's midface lift are ideal options for the treatment of prominent eyes. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  5. Collateral and debt maturity choice: A signaling model

    NARCIS (Netherlands)

    Lensink, B.W.; Pham, 27735

    2005-01-01

    This paper derives optimal loan policies under asymmetric information where banks offer loan contracts of long and short duration, backed or unbacked with collateral. The main novelty of the paper is that it analyzes a setting in which high quality firms use collateral as a complementary device

  6. 12 CFR 614.4250 - Collateral evaluation standards.

    Science.gov (United States)

    2010-01-01

    ..., personal, or intangible property is taken as security for a loan or is the subject of a lease, an evaluation of such property shall be performed in accordance with § 614.4260 and the institutions' policies and procedures. Such a collateral evaluation shall be identified as either a collateral valuation or a...

  7. Exercise promotes collateral artery growth mediated by monocytic nitric oxide.

    Science.gov (United States)

    Schirmer, Stephan H; Millenaar, Dominic N; Werner, Christian; Schuh, Lisa; Degen, Achim; Bettink, Stephanie I; Lipp, Peter; van Rooijen, Nico; Meyer, Tim; Böhm, Michael; Laufs, Ulrich

    2015-08-01

    Collateral artery growth (arteriogenesis) is an important adaptive response to hampered arterial perfusion. It is unknown whether preventive physical exercise before limb ischemia can improve arteriogenesis and modulate mononuclear cell function. This study aimed at investigating the effects of endurance exercise before arterial occlusion on MNC function and collateral artery growth. After 3 weeks of voluntary treadmill exercise, ligation of the right femoral artery was performed in mice. Hindlimb perfusion immediately after surgery did not differ from sedentary mice. However, previous exercise improved perfusion restoration ≤7 days after femoral artery ligation, also when exercise was stopped at ligation. This was accompanied by an accumulation of peri-collateral macrophages and increased expression of endothelial nitric oxide synthase and inducible nitric oxide synthase (iNOS) in hindlimb collateral and in MNC of blood and spleen. Systemic monocyte and macrophage depletion by liposomal clodronate but not splenectomy attenuated exercise-induced perfusion restoration, collateral artery growth, peri-collateral macrophage accumulation, and upregulation of iNOS. iNOS-deficient mice did not show exercise-induced perfusion restoration. Transplantation of bone marrow-derived MNC from iNOS-deficient mice into wild-type animals inhibited exercise-induced collateral artery growth. In contrast to sedentary controls, thrice weekly aerobic exercise training for 6 months in humans increased peripheral blood MNC iNOS expression. Circulating mononuclear cell-derived inducible nitric oxide is an important mediator of exercise-induced collateral artery growth. © 2015 American Heart Association, Inc.

  8. Collateral Informant Assessment in Alcohol Use Research Involving College Students

    Science.gov (United States)

    Hagman, Brett T.; Cohn, Amy M.; Noel, Nora E.; Clifford, Patrick R.

    2010-01-01

    Objective: This study examined the associations between college students' self-reported alcohol use and corresponding collateral reports and identified factors that influence agreement between both sets of reports. Participants/Methods: Subject-collateral pairs (N = 300) were recruited from undergraduate psychology courses. Results: Data yielded…

  9. 27 CFR 25.105 - Release of collateral security.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Release of collateral security. 25.105 Section 25.105 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE... of Bonds Or Consents of Surety § 25.105 Release of collateral security. Bonds, notes, and other...

  10. 48 CFR 32.304-6 - Other collateral security.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Other collateral security. 32.304-6 Section 32.304-6 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION... collateral security. The following are examples of other forms of security that, although seldom invoked...

  11. 47 CFR 1.1907 - Return of property or collateral.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Return of property or collateral. 1.1907 Section 1.1907 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Collection of Claims Owed the United States General Provisions § 1.1907 Return of property or collateral...

  12. 13 CFR 120.395 - What is SBA's collateral position?

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false What is SBA's collateral position? 120.395 Section 120.395 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Special Purpose Loans Builders Loan Program § 120.395 What is SBA's collateral position? SBA will require...

  13. 12 CFR 615.5335 - Bank net collateral ratio.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Bank net collateral ratio. 615.5335 Section 615.5335 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM FUNDING AND FISCAL AFFAIRS, LOAN POLICIES AND OPERATIONS, AND FUNDING OPERATIONS Surplus and Collateral Requirements § 615.5335 Bank net...

  14. 75 FR 64710 - Public Roundtable on Individual Customer Collateral Protection

    Science.gov (United States)

    2010-10-20

    ... related to individual customer collateral protection in the context of the CFTC's rulemaking efforts... customer collateral protection in the context of the Act, may do so via: paper submission to David Stawick... be in English or be accompanied by an English translation. All submissions provided to the CFTC in...

  15. On the Possible Interaction Mechanism between Collateral Vessels and Restenosis

    NARCIS (Netherlands)

    Zun, P.S.; Hoekstra, A.G.

    2015-01-01

    Several clinical studies and their meta-analysis suggest that developed collateral vessels in the heart correlate to an increased risk of in-stent restenosis. The possible physiological interaction between the collateral development and in-stent restenosis is investigated in this study. Based on

  16. LARGE-SCALE FLOWS IN PROMINENCE CAVITIES

    International Nuclear Information System (INIS)

    Schmit, D. J.; Gibson, S. E.; Tomczyk, S.; Reeves, K. K.; Sterling, Alphonse C.; Brooks, D. H.; Williams, D. R.; Tripathi, D.

    2009-01-01

    Regions of rarefied density often form cavities above quiescent prominences. We observed two different cavities with the Coronal Multichannel Polarimeter on 2005 April 21 and with Hinode/EIS on 2008 November 8. Inside both of these cavities, we find coherent velocity structures based on spectral Doppler shifts. These flows have speeds of 5-10 km s -1 , occur over length scales of tens of megameters, and persist for at least 1 hr. Flows in cavities are an example of the nonstatic nature of quiescent structures in the solar atmosphere.

  17. Hydrogen line formation in the quescent prominences

    International Nuclear Information System (INIS)

    Tsovookhuu, Ch.

    1980-01-01

    Equations of transfer and statistical equilibrium for hydronen atom with eight bound levels and continuum are solved simultaneously. A plane-parallel layer located perpendicular to the Sun surface is taken as a geometrical model. Input parameters of the physical model are optical thickness in the center of Hsub(α) line, electron temperature and concentration in the layer center are well as temperature and density gradients. Functions of sources, line profiles, total energies and the Balmer decrements, which are compared with observations and theoretical calculations made by other authors, have been calculated. The comparison shows that the results are quite acceptable and can be used when analyzing the spectrum and determining physical parameters of solar prominences. Dependence of different performances of the line (equivalent width, central intensity, halfwidth, depth of central depression etc.) on values of initial model parameters is investigated. Line halfwidth is more sensitive to the temperatuu value in the layer center, while central intensity - to the value of temperature gradient and a depth of central depression - to electron concentration. Calculated were shares of primary sources responsible for different excitation mechanism depending on total optical thickness as well as mean probabilities of quantum yield out of a medium which can be used during parametric accountancy of radiation diffusion in solar prominences [ru

  18. Effect of nitroglycerin on myocardial collateral conductance in awake dogs

    International Nuclear Information System (INIS)

    Brazzamano, S.; Rembert, J.C.; Greenfield, J.C. Jr.

    1988-01-01

    Conductance of the coronary collateral circulation during the course of two abrupt circumflex coronary occlusions was measured in awake dogs ∼ 2 wk after collateral vessels were stimulated to develop. The pressure gradient from the central aorta to the distal circumflex coronary artery was measured, and myocardial blood flow was determined by 9-μm radioactive microspheres at 30 s and 4 min after coronary occlusions. Collateral conductance was calculated as mean collateral blood flow divided by the mean aorta-coronary pressure gradient. Before nitroglycerin, collateral conductance increased in all eight dogs from 30 s to 4 min. After nitroglycerin administration, the conductance at 30 s increased from the prenitroglycerin control value to 0.014 ± 0.012 ml·min -1 ·g -1 ·mmHg -1 . The mean change in conductance from 30 s to 4 min postnitroglycerin was significantly less than during prenitroglycerin. These data indicate that an increase in conductance during coronary occlusion occurs even in the immature collateral circulation. This effect presumably takes place in the arterial smooth muscle at the origin of the collateral vasculature

  19. Collaterals 2016: Translating the collaterome around the globe.

    Science.gov (United States)

    Liebeskind, David S; Woolf, Graham W; Shuaib, Ashfaq

    2017-06-01

    Collaterals 2016 (third International Symposium on Collaterals to the Brain) was a multidisciplinary scientific conference focused on collateral circulation in acute ischemic stroke. Decisive challenges include generalizability of optimal triage and selection paradigms based on collateral status for definitive treatment of acute ischemic stroke, rapid dissemination of expert methods, and the urgent need to leverage networking opportunities for stroke science related to the hemodynamics of collaterals. The collaterome, or individual capacity to offset ischemia in the brain, and determination of a favorable collateral profile have become pivotal factors in consideration of the precision medicine of stroke decision-making. The conference convened over 50 invited faculty from around the world to connect on-site participants at a state-of-the-art facility with remote audiences in more than 22 countries and regions. The 2½-day program was structured into 40-min sessions devoted to key issues in translating the collaterome in acute stroke therapy across the globe. This unique forum of expertise emphasized the timely impact of collaterals on a monumental scale, encouraging maximal participation, rapid diffusion and added value of a diverse networking resource. The meeting format established a model geographical framework and innovative videoconferencing platform for future scientific conferences.

  20. Zinc release from Schaffer collaterals and its significance.

    Science.gov (United States)

    Takeda, Atsushi; Nakajima, Satoko; Fuke, Sayuri; Sakurada, Naomi; Minami, Akira; Oku, Naoto

    2006-02-15

    On the basis of the evidence that approximately 45% of Schaffer collateral boutons are zinc-positive, zinc release from Schaffer collaterals and its action were examined in hippocampal slices. When zinc release from Schaffer collaterals was examined using ZnAF-2, a membrane-impermeable zinc indicator, ZnAF-2 signal in the stratum radiatum of the CA1 was increased by tetanic stimuli at 100 Hz for 1s, suggesting that zinc is released from Schaffer collaterals in a calcium- and impulse-dependent manner. An in vivo microdialysis experiment indicated that the perfusion with 10 microM zinc significantly decreases extracellular glutamate concentration in the CA1. When tetanic stimuli at 100 Hz for 5s were delivered to the dentate granule cells, the increase in calcium signal in the stratum radiatum of the CA1, as well as in the stratum lucidum of the CA3, was attenuated by addition of 10 microM zinc, while enhanced by addition of 1mM CaEDTA, a membrane-impermeable zinc chelator. The increase in calcium signal in the CA1, in which Schaffer collateral synapses exist, during delivery of tetanic stimuli at 100 Hz for 1s to the Schaffer collateral-commissural pathway was also significantly enhanced by addition of 1mM CaEDTA. These results suggest that zinc released from Schaffer collaterals suppressively modulates presynaptic and postsynaptic calcium signaling in the CA1, followed by the suppression of glutamate release.

  1. Longitudinal anterior-to-posterior shift of collateral channels in patients with moyamoya disease: an implication for its hemorrhagic onset.

    Science.gov (United States)

    Yamamoto, Shusuke; Hori, Satoshi; Kashiwazaki, Daina; Akioka, Naoki; Kuwayama, Naoya; Kuroda, Satoshi

    2018-03-23

    OBJECTIVE This study aimed to assess longitudinal changes in the collateral channels originating from the lenticulostriate artery (LSA), posterior communicating artery (PCoA), and anterior and posterior choroidal arteries (AChA and PChA, respectively) during disease progression and/or aging. The impact of collateral channels on onset type was also examined. METHODS This study included 71 involved hemispheres in 41 patients with moyamoya disease. The disease was categorized into 6 stages according to Suzuki's angiographic staging system. The degree of development of each moyamoya vessel was categorized into 3 grades. RESULTS The LSA started to dilate in stage 2, showed the most prominent development in stage 3, and decreased in more advanced stages (p PCoA started to dilate in stage 3 and showed the most prominent development in stage 4 (p = 0.03). The PChA started to dilate in stage 3 and showed the most prominent development in stages 4 to 5 (p PCoA (p = 0.02, R = 0.28) and PChA (p PCoA, AChA, and PChA more distinctly developed in hemispheres with intracerebral or intraventricular hemorrhage than in hemispheres with ischemic stroke or transient ischemic attack (p < 0.001, p = 0.03, and p = 0.03, respectively). CONCLUSIONS This study suggests that the collateral channels through moyamoya vessels longitudinally shift from the anterior to posterior component during disease progression and aging, which may be closely related to the onset of hemorrhagic stroke in adult moyamoya disease.

  2. Transarterial chemoembolization through collateral vessels in hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Hye; Han, Joon Koo; Chung, Jin Wook; Park, Jae Hyung; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1993-11-15

    We performed 70 procedures of transarterial chemoembolization (TAE) through extrahepatic collateral vessels (n=27) or parasitic feeders (n=18) in 45 hepatocellular carcinoma patients. The collaterals developed after interruption of the hepatic artery due to repeated TAE (n=17), surgical ligation (n=7)and primary celiac occlusion (n=3). Radiologic findings suggest the existence of parasitic or collateral supply for hepatocellular carcinoma were 1) a focal defect of Lipiodol retention on CT or plain film after TAE via the hepatic artery, 2) dilated and tortuous vessels around the mass on angiography, 3) persistent elevation of the level of serum alpha-fetoprotein or continuous clinical symptoms in spite of sufficient devascularization of the tumor via the hepatic artery, and 4) radiological findings of direct invasion into adjacent organ. The sites of the catheter placement were the inferior phrenic artery(n=19), omental branches(n=16), periportal collaterals (n=6), pancreaticodenal arcade (n=3), gastroduodenal artery(n=3), internal mammary artery (n=2), intercosal artery (n=2), lateral thoracic artery (n=1), bronchial artery (n=1), and colic branches (n=1). Masses feeded by the inferior phrenic and chest wall collaterals were usually located at the dome area of the liver, and the omental and gastroduodenal collaterals developed in the masses located at the inferior tip of the liver. After TAE via collateral vessels, 37 patients underwent follow-up study. In 18 cases(48%), the tumor favorably responded to TAE. Specific complications of collateral TAE were epigastric soreness (n=10), severe shoulder pain (n=4), and embolization of the spinal artery during embolization through the intercostal artery (n=1). In conclusion, various extrahepatic collateals are important alternative or addition routes for effective chemoembolization in patients with advanced hepatoma, and early recognition of the parasitic supply and the effort to perform TAE via collaterals is very

  3. Transarterial chemoembolization through collateral vessels in hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Kim, Ji Hye; Han, Joon Koo; Chung, Jin Wook; Park, Jae Hyung; Han, Man Chung

    1993-01-01

    We performed 70 procedures of transarterial chemoembolization (TAE) through extrahepatic collateral vessels (n=27) or parasitic feeders (n=18) in 45 hepatocellular carcinoma patients. The collaterals developed after interruption of the hepatic artery due to repeated TAE (n=17), surgical ligation (n=7)and primary celiac occlusion (n=3). Radiologic findings suggest the existence of parasitic or collateral supply for hepatocellular carcinoma were 1) a focal defect of Lipiodol retention on CT or plain film after TAE via the hepatic artery, 2) dilated and tortuous vessels around the mass on angiography, 3) persistent elevation of the level of serum alpha-fetoprotein or continuous clinical symptoms in spite of sufficient devascularization of the tumor via the hepatic artery, and 4) radiological findings of direct invasion into adjacent organ. The sites of the catheter placement were the inferior phrenic artery(n=19), omental branches(n=16), periportal collaterals (n=6), pancreaticodenal arcade (n=3), gastroduodenal artery(n=3), internal mammary artery (n=2), intercosal artery (n=2), lateral thoracic artery (n=1), bronchial artery (n=1), and colic branches (n=1). Masses feeded by the inferior phrenic and chest wall collaterals were usually located at the dome area of the liver, and the omental and gastroduodenal collaterals developed in the masses located at the inferior tip of the liver. After TAE via collateral vessels, 37 patients underwent follow-up study. In 18 cases(48%), the tumor favorably responded to TAE. Specific complications of collateral TAE were epigastric soreness (n=10), severe shoulder pain (n=4), and embolization of the spinal artery during embolization through the intercostal artery (n=1). In conclusion, various extrahepatic collateals are important alternative or addition routes for effective chemoembolization in patients with advanced hepatoma, and early recognition of the parasitic supply and the effort to perform TAE via collaterals is very

  4. Blood pressure and collateral circulation in acute ischemic stroke.

    Science.gov (United States)

    Wufuer, A; Mijiti, P; Abudusalamu, R; Dengfeng, H; Jian, C; Jianhua, M; Xiaoning, Z

    2018-03-20

    This study aimed to evaluate the effect of different blood pressure (BP) parameters on the collateral circulation in a retrospective cohort of patients with acute ischemic stroke and ipsilateral internal carotid artery (ICA) occlusion. The degree of intracranial collaterals was graded according to the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) Collateral Flow Grading System. At 12-72 h after stroke onset, six BP measurements were obtained in 124 patients with ICA occlusion. Baseline clinical and imaging characteristics were collected. Group comparisons were performed, and the collateral score (CS) was assessed and entered into a logistic regression analysis. In all, 80 (64.5%) patients displayed good collateral filling (CS ≥ 2). Good intracranial collaterals were more frequently associated with the development of collaterals in the anterior communicating artery, posterior communicating artery, and leptomeningeal artery. The systolic blood pressure (SBP; p = 0.018), diastolic blood pressure (DBP; p = 0.013), and mean arterial pressure (MAP; p = 0.016) were significantly associated with good CS. Median CS was highest when SBP was 120-130 mm Hg (p = 0.034). Logistic regression analysis showed that hypertension (p = 0.026, OR: 0.380, 95% CI: 0.163-0.890) was a significant predictor of poor CS. The development of collateral circulation in patients with acute ischemic stroke with ICA occlusion may be influenced by BP. A moderately decreased SBP is associated with good integrity of the collateral circulation in patients with acute ischemic stroke with occlusion of the ICA.

  5. 13 CFR 120.1850 - Will the Collateral be held by SBA?

    Science.gov (United States)

    2010-01-01

    ... Loan Program) § 120.1850 Will the Collateral be held by SBA? Yes, SBA or its expressly authorized agent... all Collateral for SISMBD Loans in a custodial account. Certificates held as Collateral must be in... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Will the Collateral be held by SBA...

  6. Collateral veins in left renal vein stenosis demonstrated via CT

    Energy Technology Data Exchange (ETDEWEB)

    Lien, H.H.; Lund, G.; Talle, K.

    1983-02-01

    Twelve patients with left renal vein stenosis from tumor compression were studied with CT. All had distended collateral veins in the perirenal space which either formed a radiating or a cobweb pattern or appeared as marked longitudinal veins. Inferior phrenic vein branches were seen in seven patients and were considerably enlarged in two. Other major veins possibly taking part in collateral circulation could not be recognized due to obliteration of fat planes. The renal fascia was thickened in eleven patients, probably due to edema. A close study of the perirenal space with CT may give valuable information about collateral development.

  7. Collateral veins in left renal vein stenosis demonstrated via CT

    International Nuclear Information System (INIS)

    Lien, H.H.; Lund, G.; Talle, K.

    1983-01-01

    Twelve patients with left renal vein stenosis from tumor compression were studied with CT. All had distended collateral veins in the perirenal space which either formed a radiating or a cobweb pattern or appeared as marked longitudinal veins. Inferior phrenic vein branches were seen in seven patients and were considerably enlarged in two. Other major veins possibly taking part in collateral circulation could not be recognized due to obliteration of fat planes. The renal fascia was thickened in eleven patients, probably due to edema. A close study of the perirenal space with CT may give valuable information about collateral development. (orig.)

  8. Flotation process control optimisation at Prominent Hill

    International Nuclear Information System (INIS)

    Lombardi, Josephine; Muhamad, Nur; Weidenbach, M.

    2012-01-01

    OZ Minerals' Prominent Hill copper- gold concentrator is located 130 km south east of the town of Coober Pedy in the Gawler Craton of South Australia. The concentrator was built in 2008 and commenced commercial production in early 2009. The Prominent Hill concentrator is comprised of a conventional grinding and flotation processing plant with a 9.6 Mtpa ore throughput capacity. The flotation circuit includes six rougher cells, an IseMill for regrinding the rougher concentrate and a Jameson cell heading up the three stage conventional cell cleaner circuit. In total there are four level controllers in the rougher train and ten level controllers in the cleaning circuit for 18 cells. Generic proportional — integral and derivative (PID) control used on the level controllers alone propagated any disturbances downstream in the circuit that were generated from the grinding circuit, hoppers, between cells and interconnected banks of cells, having a negative impact on plant performance. To better control such disturbances, FloatStar level stabiliser was selected for installation on the flotation circuit to account for the interaction between the cells. Multivariable control was also installed on the five concentrate hoppers to maintain consistent feed to the cells and to the IsaMill. An additional area identified for optimisation in the flotation circuit was the mass pull rate from the rougher cells. FloatStar flow optimiser was selected to be installed subsequent to the FloatStar level stabiliser. This allowed for a unified, consistent and optimal approach to running the rougher circuit. This paper describes the improvement in the stabilisation of the circuit achieved by the FloatStar level stabiliser by using the interaction matrix between cell level controllers and the results and benefits of implementing the FloatStar flow optimiser on the rougher train.

  9. Use of collateral sensitivity networks to design drug cycling protocols that avoid resistance development

    DEFF Research Database (Denmark)

    Imamovic, Lejla; Sommer, Morten

    2013-01-01

    collateral sensitivity and resistance profiles, revealing a complex collateral sensitivity network. On the basis of these data, we propose a new treatment framework-collateral sensitivity cycling-in which drugs with compatible collateral sensitivity profiles are used sequentially to treat infection...... pathogens. These results provide proof of principle for collateral sensitivity cycling as a sustainable treatment paradigm that may be generally applicable to infectious diseases and cancer....

  10. Collateral and SME financing in Bangladesh: An analysis across bank size and bank ownership types

    OpenAIRE

    Rahman, Ashiqur; Rahman, Mosiqure Twyeafur; Ključnikov, Aleksandr

    2016-01-01

    We examine the issue of pledging collateral and its effect on access to credit, interest rates and credit risk of SMEs financing in Bangladesh with respect to bank size. We also examine the collateral classification (fixed assets collateral, personal guarantee and third-party guarantee) by bank ownership types to find what types of collateral are preferred by public, private and foreign banks in Bangladesh for lending to firms. In addition to that, we examine whether collateral requirements a...

  11. Screening in the credit market when the collateral value is stochastic

    OpenAIRE

    Niinimäki, Juha-Pekka

    2009-01-01

    This theoretical paper explores screening with loan collateral when both the collateral value and the probability of project success fluctuate. Some model versions challenge the classic findings of Bester (1985) by showing that high-risk borrowers may in such case be more willing to pledge collateral than low-risk borrowers. Abundant collateral then would not signal low risk. The results may help explain the mixed empirical findings on the role of collateral. The paper also extends the analys...

  12. All-inside arthroscopic lateral collateral ligament repair for ankle instability with a knotless suture anchor technique.

    Science.gov (United States)

    Vega, Jordi; Golanó, Pau; Pellegrino, Alexandro; Rabat, Eduard; Peña, Fernando

    2013-12-01

    Recently, arthroscopic-assisted techniques have been described to treat lateral ankle instability with excellent results. However, complications including neuritis of the superficial peroneal or sural nerve, and pain or discomfort due to a prominent anchor or suture knot have been reported. The aim of this study was to describe a novel technique, the "all-inside arthroscopic lateral collateral ankle ligament repair," and its results for treating patients with ankle instability. Sixteen patients (10 men and 6 women, mean age 29.3 years, 17-46) with lateral ankle instability were treated with an arthroscopic procedure. Using a suture passer and a knotless anchor, the ligaments were repaired with an all-inside technique. The right ankle was affected in 10 cases. Mean follow-up was 22.3 (12-35) months. On arthroscopic examination, 13 patients had an isolated anterior talofibular ligament (ATFL) injury, and in 3 patients, both the ATFL and calcaneofibular ligament (CFL) were affected. All-inside arthroscopic anatomic repair of the lateral collateral ligament complex was performed in all cases. All patients reported subjective improvement of their ankle instability. The mean AOFAS score increased from 67 preoperatively to 97 at final follow-up. No major complications were reported. The all-inside arthroscopic ligament repair was a safe, reliable, and reproducible technique that both provided an anatomic repair of the lateral collateral ligament complex and restored ankle stability while preserving all the advantages of an arthroscopic technique. Level IV, retrospective case series.

  13. Pricing a Collateralized Derivative Trade with a Funding Value Adjustment

    Directory of Open Access Journals (Sweden)

    Chadd B. Hunzinger

    2015-01-01

    Full Text Available The 2008 credit crisis changed the manner in which derivative trades are conducted. One of these changes is the posting of collateral in a trade to mitigate the counterparty credit risk. Another is the realization that banks are not risk-free and, as a result, cannot borrow at the risk-free rate any longer. The latter led banks to introduced the controversial adjustment to derivative prices, known as a funding value adjustment (FVA, which is interlinked with the posting of collateral. In this paper, we extend the Cox, Ross and Rubinstein (CRR discrete-time model to include collateral and FVA. We prove that this derived model is a discrete analogue of Piterbarg’s partial differential equation (PDE, which describes the price of a collateralized derivative. The fact that the two models coincide is also verified by numerical implementation of the results that we obtain.

  14. Leptomeningeal collateral status predicts outcome after middle cerebral artery occlusion

    DEFF Research Database (Denmark)

    Madelung, Christopher Fugl; Ovesen, C; Trampedach, C

    2017-01-01

    NCCT and according to European Cooperative Acute Stroke Study (ECASS) criteria. Modified Rankin Scale score was assessed at 90 days, and mortality at 1 year. RESULTS: At 90 days, median (IQR) modified Rankin Scale score in patients with poor collateral status was 4 (3-6) compared to 2 (1-4) in patients...... population (P = .001). CONCLUSIONS: Leptomeningeal collateral status predicts functional outcome, mortality, and hemorrhagic transformation following middle cerebral artery occlusion.......OBJECTIVES: Perfusion through leptomeningeal collateral vessels is a likely pivotal factor in the outcome of stroke patients. We aimed to investigate the effect of collateral status on outcome in a cohort of unselected, consecutive stroke patients with middle cerebral artery occlusion undergoing...

  15. The medial collateral ligament of the elbow joint

    DEFF Research Database (Denmark)

    Floris, S; Olsen, Bo Sanderhoff; Dalstra, Michel

    1998-01-01

    Eighteen osteoligamentous elbow joint specimens were included in a study of the medial collateral ligament complex (MCL). The morphologic characteristics of the MCL were examined, and three-dimensional kinematic measurements were taken after selective ligament dissections were performed. On morph......Eighteen osteoligamentous elbow joint specimens were included in a study of the medial collateral ligament complex (MCL). The morphologic characteristics of the MCL were examined, and three-dimensional kinematic measurements were taken after selective ligament dissections were performed...

  16. Leptomeningeal collateral status predicts outcome after middle cerebral artery occlusion.

    Science.gov (United States)

    Madelung, C F; Ovesen, C; Trampedach, C; Christensen, A; Havsteen, I; Hansen, C K; Christensen, H

    2018-01-01

    Perfusion through leptomeningeal collateral vessels is a likely pivotal factor in the outcome of stroke patients. We aimed to investigate the effect of collateral status on outcome in a cohort of unselected, consecutive stroke patients with middle cerebral artery occlusion undergoing reperfusion therapy. This retrospectively planned analysis was passed on prospectively collected data from 187 consecutive patients with middle cerebral artery occlusion admitted within 4.5 hours to one center and treated with intravenous thrombolysis alone (N = 126), mechanical thrombectomy alone (N = 5), or both (N = 56) from May 2009 to April 2014. Non-contrast CT (NCCT) and computed tomography angiography (CTA) were provided on admission and NCCT repeated at 24 hours. Collateral status was assessed based on the initial CTA. Hemorrhagic transformation was evaluated on the 24-hour NCCT and according to European Cooperative Acute Stroke Study (ECASS) criteria. Modified Rankin Scale score was assessed at 90 days, and mortality at 1 year. At 90 days, median (IQR) modified Rankin Scale score in patients with poor collateral status was 4 (3-6) compared to 2 (1-4) in patients with good collateral status (P collateral status were less likely to achieve a good 90-day outcome (modified Rankin Scale score 0-2) (Adjusted odds ratio 0.27, 95% CI: 0.09-0.86). During the first year, 40.9% of patients with poor collateral status died vs 18.2% of the remaining population (P = .001). Leptomeningeal collateral status predicts functional outcome, mortality, and hemorrhagic transformation following middle cerebral artery occlusion. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. COLLATERAL IN SMES’ LENDING: BANKS’ REQUIREMENTS VS CUSTOMERS’ EXPECTATIONS

    OpenAIRE

    Daniel BADULESCU

    2011-01-01

    SMEs’ support and importance in developing economies should not be only declarative. Searching for funding, managers encounter various obstacles arising from information asymmetry, lack of experience, severe market conditions, and insufficient or unsatisfactory collaterals for banks (OECD 2006; Badulescu and Badulescu 2010; OECD 2000 and 2004; Lin and Sun 2006; Toivanen and Cresy, 2000). The collateral issue is extensively discussed in literature – preventing moral hazard, the alignment the i...

  18. Atraumatic medial collateral ligament oedema in medial compartment knee osteoarthritis

    International Nuclear Information System (INIS)

    Bergin, D.; Keogh, C.; O'Connell, M.; Zoga, A.; Rowe, D.; Shah, B.; Eustace, S.

    2002-01-01

    Objective: To describe and determine the prevalence of atraumatic medial collateral oedema identified in patients with medial compartment osteoarthritis. Design and patients: Sixty patients, 30 patients with medial compartment knee osteoarthritis (Kellgren and Lawrence grade 2 to 4) and 30 age-matched patients with atraumatic knee pain without osteoarthritis, referred for MR imaging over a 2 year period were included in the study. In each case, severity of osteoarthritis was recorded on radiographs and correlated with the presence or absence of medial collateral ligament oedema at MR imaging. Results: Medial collateral oedema was identified in 27 of the 30 patients with osteoarthritis, of whom 14 had grade 1 oedema and 13 had grade 2 oedema compared with the presence of medial collateral ligament oedema (grade 1) in only two of the 30 control patients without osteoarthritis (P<<0.0001). Conclusion: Medial collateral oedema is common in patients with osteoarthritis in the absence of trauma. When identified, medial collateral ligament oedema should be considered to be a feature of osteoarthritis and should not be incorrectly attributed to an acute traumatic injury. (orig.)

  19. Propranolol modulates the collateral vascular responsiveness to vasopressin via a G(α)-mediated pathway in portal hypertensive rats.

    Science.gov (United States)

    Lee, Jing-Yi; Huo, Teh-Ia; Huang, Hui-Chun; Lee, Fa-Yauh; Lin, Han-Chieh; Chuang, Chiao-Lin; Chang, Ching-Chih; Wang, Sun-Sang; Lee, Shou-Dong

    2011-12-01

    Gastro-oesophageal variceal haemorrhage is one of the most dreadful complications of portal hypertension and can be controlled with vasoconstrictors. Nevertheless, sympathetic tone abnormality and vascular hyporesponsiveness in portal hypertension may impede the haemostatic effects of vasoconstrictors. Propranolol, a β-blocker binding the G-protein-coupled adrenoceptor, is a portal hypotensive agent. However, whether propranolol influences the collateral vasoresponse is unknown. Portal hypertension was induced by PVL (portal vein ligation) in Sprague-Dawley rats. In an acute study with an in situ perfusion model, the collateral responsiveness to AVP (arginine vasopressin) was evaluated with vehicle, propranolol (10 μmol/l), propranolol plus suramin (100 μmol/l, a G(α) inhibitor) or suramin pre-incubation. G(α) mRNA expression in the splenorenal shunt, the most prominent intra-abdominal collateral vessel, was measured. In the chronic study, rats received DW (distilled water) or propranolol (10 mg x kg(-1) of body weight x day(-1)) for 9 days. Then the concentration-response relationship of AVP and G(α) mRNA expression were assessed. Propranolol pre-incubation elevated the perfusion pressure changes of collaterals in response to AVP, which was inhibited by suramin. The splenorenal shunt G(αq) and G(α11) mRNA expression were enhanced by propranolol. The group treated with propranolol plus suramin had a down-regulation of G(α11) as compared with the propranolol group. Chronic propranolol treatment reduced mean arterial pressure, PP (portal pressure) and the perfusion pressure changes of collaterals to AVP. G(αs) expression was up-regulated. In conclusion, propranolol pre-incubation enhanced the portal-systemic collateral AVP responsiveness in portal hypertensive rats, which was related to G(αq) and G(α11) up-regulation. In contrast, the attenuated AVP responsiveness by chronic propranolol treatment was related to G(αs) up-regulation. The G(α) signalling

  20. Injury to ulnar collateral ligament of thumb.

    Science.gov (United States)

    Madan, Simerjit Singh; Pai, Dinker R; Kaur, Avneet; Dixit, Ruchita

    2014-02-01

    Injury of the ulnar collateral ligament (UCL) of thumb can be incapacitating if untreated or not treated properly. This injury is notorious for frequently being missed by inexperienced health care personnel in emergency departments. It has frequently been described in skiers, but also occurs in other sports such as rugby, soccer, handball, basketball, volleyball and even after a handshake. The UCL of the thumb acts as a primary restraint to valgus stress and is injured if hyperabduction and hyperextension forces are applied to the first metacarpophalangeal joint. The diagnosis is best established clinically, though MRI is the imaging modality of choice. Many treatment options exist, surgical treatment being offered depending on various factors, including timing of presentation (acute or chronic), grade (severity of injury), displacement (Stener lesion), location of tear (mid-substance or peripheral), associated or concomitant surrounding tissue injury (bone, volar plate, etc.), and patient-related factors (occupational demands, etc.). This review aims to identify the optimal diagnostic techniques and management options for UCL injury available thus far. © 2014 Chinese Orthopaedic Association and Wiley Publishing Asia Pty Ltd.

  1. The Computational Processing of Intonational Prominence: A Functional Prosody Perspective

    OpenAIRE

    Nakatani, Christine Hisayo

    1997-01-01

    Intonational prominence, or accent, is a fundamental prosodic feature that is said to contribute to discourse meaning. This thesis outlines a new, computational theory of the discourse interpretation of prominence, from a FUNCTIONAL PROSODY perspective. Functional prosody makes the following two important assumptions: first, there is an aspect of prominence interpretation that centrally concerns discourse processes, namely the discourse focusing nature of prominence; and second, the role of p...

  2. Prominent Optic Disc Featured in Inherited Retinopathy.

    Science.gov (United States)

    Todorova, M G; Bojinova, R I; Valmaggia, C; Schorderet, D F

    2017-04-01

    Background We investigated the relationship between prominent optic disc (POD) and inherited retinal dystrophy (IRD). Patients and Methods A cross-sectional consecutive study was performed in 10 children and 11 adults of 7 non-related families. We performed clinical phenotyping, including a detailed examination, fundus autofluorescence, and colour fundus and OCT imaging. Genetic testing was subsequently performed for all family members presenting retinal pathology. Results In 4 members of a 3-generation family, hyperfluorescent deposits on the surface of POD were related to a p.(L224M) heterozygous mutation in BEST1 . In the second family, one member presented deposits located on the surface on hyperaemic OD and a compound p.(R141H);(A195V) mutation in BEST1 . In the third family, POD was observed in father and child with early onset cone-rod dystrophy and a novel autosomal recessive p.(W31*) homozygous mutation in ABCA4 . In the fourth family, POD with "mulberry-like" deposits and attenuated vessels were observed in a 7-year old girl, with a mutation in USH1A , and with early onset rod-cone dystrophy, associated with hearing loss. In the fifth family, blurry OD with tortuous vessels was observed in 4 consanguineous female carriers and a hemizygous boy with a p.(R200H) mutation in the X-linked retinoschisis RS1 . In the sixth family, a mother and her son were both affected with POD and attenuated peripapillary vessels, and presented with a p.(Y836C) heterozygous mutation in TOPORS , thus confirming autosomal dominant RP. In the seventh family, in 3 family members with POD, compound p.(L541P;A1038 V);(G1961E) mutations in ABCA4 confirmed the diagnosis of Stargardt disease. Conclusions A variety of OD findings are found in a genetically heterogeneous group of IRDs. In the presence of POD, an inherited progressive photoreceptor disease should be ruled out. Georg Thieme Verlag KG Stuttgart · New York.

  3. Signs of helicity in solar prominences and related features

    Science.gov (United States)

    Martin, S.

    This review illustrates several ways to identify the chirality (handedness) of solar prominences (filaments) from their structure and the structure of their surrounding magnetic fields in the chromosphere and corona. For prominences, these structural elements include the axial magnetic field direction, orientation of barbs, and direction of the prominence fine structure. The surrounding structures include the pattern of fibrils beneath the prominences and the pattern of coronal loops above the prominences. These ways of identifying chirality are then interpreted in terms of the formal definitions of helicity to yield a consistent set of one-to-one helicity relationships for all features. The helicity of some prominences can also be independently determined during their eruption by their fine structure, apparent crossings in the line-of-sight of different parts of the same prominence, and by large- scale twist of the prominence structure. Unlike observations of prominences (filaments) observed prior to eruption, in some cases evidence of both signs of helicity are found within the same erupting prominence. This indicates the continued application of forces on the prominences during the eruption process or the possible introduction of force(s) not present during earlier stages of their evolution.

  4. A three-dimensional model for solar prominences

    International Nuclear Information System (INIS)

    Demoulin, P.; Priest, E.R.; Anzer, U.

    1989-01-01

    Prominences have been modelled largely as one-or two-dimensional structures, and yet observations show them to possess important variations in the third dimension along the prominence axis with great arches with feet reaching down towards the solar surface. As an initial attempt to understand this structure we consider a three-dimensional linear force-free field model for the global magnetic field around a quiescent prominence. It consists of a fundamental together with a harmonic that is periodic along the prominence. At the solar surface there is a series of flux concentrations spaced out periodically on both sides of the prominence. Between a pair of oppositely directed flux concentration, the magnetic field in the prominence is stronger and tends to be less highly sheared than elsewhere. This modulation of the field strength and shear angle along the prominence decreases with height and almost disappears above 10 Mm. Prominence fields that increase with height occur when the shear is large and the length-scale for field variations perpendicular to the prominence exceeds that along it. The variation of the prominence height along the prominence is calculated and it is suggested that feet occur where the prominence sags down to low heights. For prominences of Normal polarity this tends to occur near supergranule centres where the transverse field is least, whereas for those of Inverse polarity it usually takes place near the chromospheric network where the transverse field is greatest. The effect of concentrating the base flux by including extra harmonics is also included. For Normal polarity prominences it tends to make the foot wider, and for Inverse polarity configurations, it usually creates deeper and narrower feet

  5. Radiologic analysis of the medical collateral ligament rupture

    International Nuclear Information System (INIS)

    Cho, Chung Che; Lee, Chang Jun; Kim, Kun Sang; Park, Soo Soung

    1979-01-01

    The medical collateral ligament rupture is the most common injury involving the knee joint ligaments. The ruptured medical collateral ligaments of 73 cases with clinical and surgical confirmations were radiologically analyzed. The results were obtained as follows: 1. The most risky age for tearing of the medical collateral ligament was third to fifth decades (50 cases of male and 23 of females). 2. The most common cause of the medical collateral ligament rupture was traffic accident (82.2%). 3. The mean distance of medial knee joint space was 7.9 ± 2.0 mm on the normal side and 13.7 ± 4.2 mm on the affected side. 4. The mean degree of knee joint space was 10.1 ± 2.5 on the normal side and 14.7 ± 3.8 on the affected side. 5. The fibula was the bone fractured most frequently in association with the medial collateral ligament rupture (30.6%).

  6. Association between neutrophil/lymphocyte ratio and coronary collateral circulation

    Directory of Open Access Journals (Sweden)

    Mustafa Oylumlu

    2012-03-01

    Full Text Available Objectives: To investigate relation between neutrophil/lymphocyte ratio and coronary collateral flow.Material and methods: Eighty-two patients admittedDicle University Medical Faculty Hospital Cardiology Departmentwith diagnosis of coronary artery disease anddetected significant stenosis or occlusion at least one ofthe coronary arteries, were included to study. Age, sex,presence of diabetes mellitus and hypertension, acute/stable coronary disease, body mass index, neutrophil/lymphocyte ratio, white blood count, Rentrop scores andnumber of diseased vessel were recorded.Results: Well-developed coronary collateral circulationwas found in 33 of the patients. Forty-nine patients hadpoor coronary collateral circulation. Mean age, sex, bodymass index, presence of diabetes mellitus and hypertensionwere similar in two groups. Mean neutrophil/lymphocyteratio was lower in well-developed coronary collateralcirculation group than poor coronary collateral circulationgroup, but there was no significant differences (2.78 vs2.89, p=0.12.Conclusions: There was no association between neutron/hil lymphocyte ratio and coronary collateral circulationaccording to our data. J Clin Exp Invest 2012; 3(1:29-32

  7. Ketanserin effect on limb perfusion and arterial collaterals

    International Nuclear Information System (INIS)

    Grassi, C.J.; Janicek, M.; Hollenberg, N.K.; Meyerovitz, M.F.; Harrington, D.P.

    1987-01-01

    Arterial collateral flow and major vessel patency are important in patients with intermittent claudication. Activity of serotonin released from platelets has been demonstrated experimentally, and serotonin antagonists have been investigated in treadmill testing. Ketanserin, a serotonin (5-HT/sup 2/) antagonist, was investigated in 20 patients with intermittent claudication to assess its effect on collaterals. Blood-pressure ratio (thigh/arm), mercury-strain gauge plethysmography, Doppler pressures, and repeat arteriography were performed. Ketanserin (3-30 μg/kg IA) increased collateral vessel size on angiography in 12 patients (60%) and increased blood-flow ratio and plethysmogrpahy pressures on average. These observations, confirming clinical studies that some patients show a dramatic response and others do not, might prove useful in identifying patients who will respond to ketanserin for occlusive vascular disease

  8. Redistribution of thallium-201 into right ventricle through collateral circulation

    International Nuclear Information System (INIS)

    Kataoka, Hajime; Ohkubo, Toshitaka; Takaoka, Shigeru; Ohshige, Tamao; Miyahara, Kenkichi.

    1984-01-01

    The cases of reversible right ventricular ischemia, which demonstrated redistribution of thallium (Tl)-201 into the right ventricular free wall (RVFW) through collateral channels, were reported. Two cases with complete obstruction in the proximal right coronary artery accompanied by collateral channels (left coronary artery to distal right coronary artery) underwent submaximal exercise stress Tl-201 myocardial imaging. Although the RVFW was not visualized on immediate myocardial images in one or both of the 30 0 and 60 0 left anterior oblique views in each case, three-hour delayed myocardial images showed redistribution of Tl-201 into the RVFW. It was concluded that collateral circulation affects the occurrence of redistribution of Tl-201 into the RVFW. (author)

  9. Quantification of collateral flow in humans: a comparison of angiographic, electrocardiographic and hemodynamic variables

    NARCIS (Netherlands)

    van Liebergen, R. A.; Piek, J. J.; Koch, K. T.; de Winter, R. J.; Schotborgh, C. E.; Lie, K. I.

    1999-01-01

    Evaluation of collateral vascular circulation according to hemodynamic variables and its relation to myocardial ischemia. There is limited information regarding the hemodynamic quantification of recruitable collateral vessels. Angiography of the donor coronary artery was performed before and during

  10. Coronary Collateral Growth—Back to the Future

    Science.gov (United States)

    Chilian, William M.; Penn, Marc S.; Pung, Yuh Fen; Dong, Feng; Mayorga, Maritza; Ohanyan, Vahagn; Logan, Suzanna; Yin, Liya

    2012-01-01

    The coronary collateral circulation is critically important as an adaptation of the heart to prevent the damage from ischemic insults. In their native state, collaterals in the heart would be classified as part of the microcirculation, existing as arterial-arterial anastomotic connections in the range of 30 to 100 μM in diameter. However, these vessels also show a propensity to remodel into components of the macrocirculation and can become arteries larger than a 1000 μM in diameter. This process of outward remodelling is critically important in the adaptation of the heart to ischemia because the resistance to blood flow is inversely related to the fourth power of the diameter of the vessel. Thus, an expansion of a vessel from 100 to 1000 μM would reduce resistance (in this part of the circuit) to a negligible amount and enable delivery of flow to the region at risk. Our goal in this review is to highlight the voids in understanding this adaptation to ischemia—the growth of the coronary collateral circulation. In doing so we discuss the controversies and unknown aspects of the causal factors that stimulate growth of the collateral circulation, the role of genetics, and the role of endogenous stem and progenitor cells in the context of the normal, physiological situation and under more pathological conditions of ischemic heart disease or with some of the underlying risk factors, e.g., diabetes. The major conclusion of this review is that there are many gaps in our knowledge of coronary collateral growth and this knowledge is critical before the potential of stimulating collateralization in the hearts of patients can be realized. PMID:22210280

  11. Computed tomographic diagnosis for hepatofugal collaterals in portal hypertension

    International Nuclear Information System (INIS)

    Iida, Akihiko; Sano, Akira; Imanaka, Kazufumi; Nishizawa, Sadahiko; Sasai, Keisuke

    1984-01-01

    This paper deals with the diagnostic capability of CT scan for hepatofugal collaterals in 22 patients with portal hypertension. The patients studied were those who underwent percutaneous transhepatic portography (PTP) and CT scan within a short period. Each collateral vein demonstrated by PTP was classified into three grades according to its caliber (d) : (1) Grade I, d<5mm, (2) Grade II, 5mm< d<10mm and (3) Grade III, 10mm< d. Based on the PTP finding, the demonstrability of these collaterals on the CT images was analysed comparatively. Most collaterals in Grade I failed to demonstrate on CT images, while Grade II and III well coincided with CT images, at the rate of 64% and 100% respectively. CT features of these vascular structures showed multiformity: rounded, ovoid comma-shaped, tubular or beaded, etc.. To get an accurate diagnosis, each image must be analysed together with the adjacent upper and lower ones on the fully-performed contrast enhancement technique. Image deterioration of CT was concerned with Partial Volume Phenomenon for small vessels, and motion artifacts produced by intestinal peristalses, cardiac beats and occasionally by difficulty of breath holding. In spite of such diagnostic Iimitation, CT scan provides much qualified images than conventional angiographic procedures in evaluating hepatofugal collaterals. CT scan, which is widely applied to clinical workup for cirrhosis of the liver with special reference to hepatoma, allows incidental diagnostic information about collaterals in size and course. Such simplicity of the procedure contributes to the follow-up and repeat study after sclerotherapy for esophageal varices. (author)

  12. Neutral Atom Diffusion in a Partially Ionized Prominence Plasma

    Science.gov (United States)

    Gilbert, Holly

    2010-01-01

    The support of solar prominences is normally described in terms of a magnetic force on the prominence plasma that balances the solar gravitational force. Because the prominence plasma is only partially ionized. it is necessary to consider in addition the support of the neutral component of the prominence plasma. This support is accomplished through a frictional interaction between the neutral and ionized components of the plasma, and its efficacy depends strongly on the degree of ionization of the plasma. More specifically, the frictional force is proportional to the relative flow of neutral and ion species, and for a sufficiently weakly ionized plasma, this flow must be relatively large to produce a frictional force that balances gravity. A large relative flow, of course, implies significant draining of neutral particles from the prominence. We evaluate the importance of this draining effect for a hydrogen-helium plasma, and consider the observational evidence for cross-field diffusion of neutral prominence material,

  13. Coronary Collateral Growth—Back to the Future

    OpenAIRE

    Chilian, William M.; Penn, Marc S.; Pung, Yuh Fen; Dong, Feng; Mayorga, Maritza; Ohanyan, Vahagn; Logan, Suzanna; Yin, Liya

    2011-01-01

    The coronary collateral circulation is critically important as an adaptation of the heart to prevent the damage from ischemic insults. In their native state, collaterals in the heart would be classified as part of the microcirculation, existing as arterial-arterial anastomotic connections in the range of 30 to 100 μM in diameter. However, these vessels also show a propensity to remodel into components of the macrocirculation and can become arteries larger than a 1000 μM in diameter. This proc...

  14. Historical aspects and relevance of the human coronary collateral circulation.

    Science.gov (United States)

    Seiler, Christian; Meier, Pascal

    2014-02-01

    In 1669, anastomoses between the right and left coronary artery were first documented by Richard Lower of Amsterdam. Using post-mortem imaging, a debate followed on the existence of structural inter-coronary anastomoses, which was not resolved before the first half of the 20 ieth century in case of the presence of coronary artery disease (CAD), and not before the early 1960 ies in case of the normal human coronary circulation by William Fulton. Functional coronary collateral measurements during coronary interventions were first performed only in the 1970 ies, respectively in the early 1980 ies. In humans, the existence of functional coronary collaterals in the absence of CAD has not been documented before 2003. Though the coronary collateral circulation has been recognized as an alternative source of blood supply to ischemic myocardium, its prognostic significance for the CAD population as a whole has been controversial until recently. The debate was due to different populations examined (acute versus chronic CAD, varying severity of CAD), to variable definitions of the term "prognosis", to insufficient statistical power of the investigation with rare occurrence of prognostic endpoints, to short duration of follow-up and to blunt instruments employed for collateral assessment. Individually, it has been acknowledged that a well functioning collateral supply to a myocardial area at risk for necrosis reduces infarct size, preserves ventricular function, prevents ventricular remodelling and aneurysm formation. Collectively, evidence has accumulated only recently that an extensive coronary collateral circulation is a beneficial prognosticator quoad vitam. In a recent meta-analysis on the topic, the risk ratio to die from any cause for high vs low or absent collateralization in patients with subacute myocardial infarction was 0.53 (95% confidence interval 0.15-1.92; p=0.335), and for patients with acute myocardial infarction, it was 0.63 (95% confidence interval 0

  15. Efficacy of collateral types used by financial intermediaries in KwaZulu-Natal

    OpenAIRE

    Kuhn, M.E.; Darroch, Mark A.G.; Ortmann, Gerald F.

    1997-01-01

    Collateral is an important incentive device used by lenders to encourage loan repayment. However, collateral must have secure and transferable title, it must be marketable, have low lender liquidation costs and lenders must be able to attach the collateral. Study results for rural and micro-enterprise finance institutions in KwaZulu-Natal showed that assets such as vehicles and equipment were not effective as collateral due to high costs in attaching the asset. Cessions on crops were often co...

  16. 10 CFR 609.15 - Default, demand, payment, and collateral liquidation.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Default, demand, payment, and collateral liquidation. 609... PROJECTS THAT EMPLOY INNOVATIVE TECHNOLOGIES § 609.15 Default, demand, payment, and collateral liquidation... Guaranteed Obligation. Such assignment shall include all related liens, security, and collateral rights to...

  17. 46 CFR 308.522 - Collateral deposit fund, letter of transmittal, Form MA-302.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Collateral deposit fund, letter of transmittal, Form MA... Collateral deposit fund, letter of transmittal, Form MA-302. The standard form of letter of transmittal for use in establishing a collateral deposit fund, may be obtained from the American War Risk Agency or...

  18. 12 CFR 908.32 - Collateral attacks on proceedings under this part.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Collateral attacks on proceedings under this... Rules § 908.32 Collateral attacks on proceedings under this part. If a respondent files in any court a collateral attack that purports to challenge all or any portion of a proceeding under this part, the hearing...

  19. Congenital absence of infrarenal IVC and iliac venous system : Unusual collateral Pathways

    International Nuclear Information System (INIS)

    Lee, Jin Joo; Lee, Byung Hee; Kim, Kie Hwan; Do, Young Soo; Chin, Soo Yil

    1994-01-01

    We present a case with congenital absence of the infrarenal portion of inferior vena cava and iliac venous system, showing unusual venous collaterals including the left ovarian venous collateral via parametrial venous complex, and a mesenteric-periureteric venous connection. The venous collateral pathways were demonstrated by computed tomography and venography

  20. 31 CFR 363.146 - May a certificate of indebtedness be pledged or used as collateral?

    Science.gov (United States)

    2010-07-01

    ... pledged or used as collateral? 363.146 Section 363.146 Money and Finance: Treasury Regulations Relating to... certificate of indebtedness be pledged or used as collateral? A certificate of indebtedness may not be pledged or used as collateral for the performance of an obligation. [69 FR 50309, Aug. 16, 2004. Redesignated...

  1. 10 CFR 609.16 - Perfection of liens and preservation of collateral.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Perfection of liens and preservation of collateral. 609.16... THAT EMPLOY INNOVATIVE TECHNOLOGIES § 609.16 Perfection of liens and preservation of collateral. (a... to perfect and maintain liens, as applicable, on assets which are pledged as collateral for the...

  2. 7 CFR 1980.444 - Appraisal of property serving as collateral.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 14 2010-01-01 2009-01-01 true Appraisal of property serving as collateral. 1980.444... Program § 1980.444 Appraisal of property serving as collateral. (a) Appraisal reports prepared by independent qualified fee appraisers will be required on all property that will serve as collateral. In the...

  3. 31 CFR 363.176 - May a converted savings bond be pledged or used as collateral?

    Science.gov (United States)

    2010-07-01

    ... pledged or used as collateral? 363.176 Section 363.176 Money and Finance: Treasury Regulations Relating to... a converted savings bond be pledged or used as collateral? A converted savings bond may not be pledged or used as collateral for the performance of an obligation. ...

  4. 10 CFR 611.111 - Default, demand, payment, and collateral liquidation.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Default, demand, payment, and collateral liquidation. 611... collateral liquidation. (a) In the event that the Borrower has defaulted in the making of required payments.... Attorney General, may seek to foreclose on the collateral assets and/or take such other legal action as...

  5. 10 CFR 611.108 - Perfection of liens and preservation of collateral.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Perfection of liens and preservation of collateral. 611... of collateral. (a) The Agreement and other documents related thereto shall provide that: (1) DOE and... necessary to perfect and maintain liens, as applicable, on assets which are pledged as collateral for the...

  6. 12 CFR 221.7 - Supplement: Maximum loan value of margin stock and other collateral.

    Science.gov (United States)

    2010-01-01

    ... value of margin stock and other collateral. (a) Maximum loan value of margin stock. The maximum loan... nonmargin stock and all other collateral. The maximum loan value of nonmargin stock and all other collateral... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Supplement: Maximum loan value of margin stock...

  7. 12 CFR 615.5090 - Reduction in carrying value of collateral.

    Science.gov (United States)

    2010-01-01

    ... FISCAL AFFAIRS, LOAN POLICIES AND OPERATIONS, AND FUNDING OPERATIONS Collateral § 615.5090 Reduction in carrying value of collateral. When the bank or Farm Credit Administration determines that a loan did not... withdrawn from collateral until the cause of ineligibility is remedied. When a loan has been classified as a...

  8. 7 CFR 1434.16 - Release of the honey pledged as collateral for a loan.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Release of the honey pledged as collateral for a loan... MARKETING ASSISTANCE LOAN AND LDP REGULATIONS FOR HONEY § 1434.16 Release of the honey pledged as collateral for a loan. (a)(1) A producer shall not move or dispose of any honey pledged as collateral for a loan...

  9. 7 CFR 1421.106 - Warehouse-stored marketing assistance loan collateral.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Warehouse-stored marketing assistance loan collateral... Marketing Assistance Loans § 1421.106 Warehouse-stored marketing assistance loan collateral. (a) A commodity may be pledged as collateral for a warehouse-stored marketing assistance loan in the quantity...

  10. 13 CFR 123.513 - Does SBA require collateral on its Military Reservist EIDL?

    Science.gov (United States)

    2010-01-01

    ..., or both. SBA will not decline a loan if you do not have a particular amount of collateral so long as SBA is reasonably sure that you can repay the loan. If you refuse to pledge the available collateral... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Does SBA require collateral on its...

  11. QUIESCENT PROMINENCES IN THE ERA OF ALMA: SIMULATED OBSERVATIONS USING THE 3D WHOLE-PROMINENCE FINE STRUCTURE MODEL

    Energy Technology Data Exchange (ETDEWEB)

    Gunár, Stanislav; Heinzel, Petr [Astronomical Institute, The Czech Academy of Sciences, 25165 Ondřejov (Czech Republic); Mackay, Duncan H. [School of Mathematics and Statistics, University of St Andrews, North Haugh, St Andrews KY16 9SS (United Kingdom); Anzer, Ulrich [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85740 Garching bei München (Germany)

    2016-12-20

    We use the detailed 3D whole-prominence fine structure model to produce the first simulated high-resolution ALMA observations of a modeled quiescent solar prominence. The maps of synthetic brightness temperature and optical thickness shown in the present paper are produced using a visualization method for synthesis of the submillimeter/millimeter radio continua. We have obtained the simulated observations of both the prominence at the limb and the filament on the disk at wavelengths covering a broad range that encompasses the full potential of ALMA. We demonstrate here extent to which the small-scale and large-scale prominence and filament structures will be visible in the ALMA observations spanning both the optically thin and thick regimes. We analyze the relationship between the brightness and kinetic temperature of the prominence plasma. We also illustrate the opportunities ALMA will provide for studying the thermal structure of the prominence plasma from the cores of the cool prominence fine structure to the prominence–corona transition region. In addition, we show that detailed 3D modeling of entire prominences with their numerous fine structures will be important for the correct interpretation of future ALMA observations of prominences.

  12. Study of a Large Helical Eruptive Prominence Associated with ...

    Indian Academy of Sciences (India)

    2001-04-21

    Apr 21, 2001 ... morphology of the event, energy budget of the prominence and associated. CMEs. ... magnetically driven and internally powered. Key words. ... Solar prominences are ribbons of cool (∼8000 K) dense gas (∼10. −11 gcm. −3. ) ...

  13. Collateral Determinats In Bank Risk Mananagement: The Regional Case

    Directory of Open Access Journals (Sweden)

    A. M. Karminsky

    2018-01-01

    Full Text Available Regional banks are struggling with significant obstacles in the modern Russian economy. Among them are strong competition with major big banks, strong resource restrictions, tightening the Bank of Russia’s requirements, and quite rapid expansion of financial technologies. Thus, the reduction of regional banks occurs, that produces both a negative impact on the development of small and medium enterprises (SMEs and challenges for balanced competition on the Russian market. Basically, these banks provide the settlement of region’s social and economic problems while maintaining local companies and enterprises. Collateral, as a source for losses covering, became the essential element of credit risk management in banks. Providing lenders to implement such instruments, it helps to reduce bank losses under borrower’s default. The purpose of the article relates to revealing of collateral determinants with higher impact on bank risk with the application of empirical methods (including regional level. This study is based on linear regression models evaluated by the least square method. Private data of secured small and medium business loans is used. This article presents LTV (loan-to-value as a major collateral determinant. The empirical evidence of interlinkage between collateral requirements, by the means of LTV, and risk premium is provided for loan portfolio of Russian regional banks. The hypothesis that LTV conversely correlates with risk premium is statistically proved.

  14. 38 CFR 1.913 - Liquidation of collateral.

    Science.gov (United States)

    2010-07-01

    ... security or collateral through the exercise of a power of sale in the security instrument or a nonjudicial foreclosure, and apply the proceeds to the applicable debt, if the debtor fails to pay the debt within 180 days after demand and if such action is in the best interest of the United States. Collection from...

  15. 45 CFR 30.16 - Liquidation of collateral.

    Science.gov (United States)

    2010-10-01

    ... fails to pay the debt(s) within a reasonable time after demand and if such action is in the best interests of the United States. (2) Collection from other sources, including liquidation of security or... will liquidate security or collateral through the exercise of a power of sale in the security...

  16. Collateral Information for Equating in Small Samples: A Preliminary Investigation

    Science.gov (United States)

    Kim, Sooyeon; Livingston, Samuel A.; Lewis, Charles

    2011-01-01

    This article describes a preliminary investigation of an empirical Bayes (EB) procedure for using collateral information to improve equating of scores on test forms taken by small numbers of examinees. Resampling studies were done on two different forms of the same test. In each study, EB and non-EB versions of two equating methods--chained linear…

  17. Collateral effects of antibiotics on mammalian gut microbiomes

    Science.gov (United States)

    Antibiotics are an essential component of the modern lifestyle. They improve our lives by treating disease, preventing disease, and in the case of agricultural animals by improving feed efficiency. However, antibiotic usage is not without collateral effects. The development and spread of antibiot...

  18. In vivo metacarpophalanageal joint collateral ligament length changes during flexion.

    Science.gov (United States)

    Sun, Y C; Sheng, X M; Chen, J; Qian, Z W

    2017-07-01

    We investigated the in vivo length changes of the collateral ligaments of metacarpophalangeal joint during flexion. We obtained computed tomography scans of index, middle, ring and little fingers at 0°, 30°, 60° and 90° of joint flexion from six hands of six healthy adult volunteers. Three of them had their dominant right hand studied, and the other three had their non-dominant left hand studied. We measured and analysed the radial and ulnar collateral ligaments of each metacarpophalangeal joint from the reconstructed images. We found that the dorsal and middle portions of the both radial and ulnar collateral ligament lengthened progressively during digital flexion and reached the maximum at 90° flexion. The length of the volar portion increased from 0° to 30° flexion and then decreased from 30° to 60° flexion, reaching the minimum at 90°. In conclusion, three portions of collateral ligaments on both sides of the metacarpophalangeal joint have variable length changes during flexion, which act to stabilize the joint through its flexion arc.

  19. 12 CFR 614.4245 - Collateral evaluation policies.

    Science.gov (United States)

    2010-01-01

    ... directors of each Farm Credit System institution that engages in lending or leasing secured by collateral... descriptive and detailed to provide ample support to the institution's related credit decisions; (2) Performed... Section 614.4245 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM LOAN POLICIES AND...

  20. Targeting pathogen metabolism without collateral damage to the host

    NARCIS (Netherlands)

    Haanstra, J.R.; Gerding, A.; Dolga, A.M.; Sorgdrager, F.J.H.; Buist-Homan, M.; du Toit, F.; Faber, K.N.; Holzhütter, H.-G.; Szöör, B.; Matthews, K.R.; Snoep, J.L.; Westerhoff, H.V.; Bakker, B.M.

    2017-01-01

    The development of drugs that can inactivate disease-causing cells (e.g. cancer cells or parasites) without causing collateral damage to healthy or to host cells is complicated by the fact that many proteins are very similar between organisms. Nevertheless, due to subtle, quantitative differences

  1. 31 CFR 203.21 - Collateral security requirements.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Collateral security requirements. 203.21 Section 203.21 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued... hereunder; or (iv) The depositary is closed for business by regulatory action or by proper corporate action...

  2. 31 CFR 901.7 - Liquidation of collateral.

    Science.gov (United States)

    2010-07-01

    ... reasonable time after demand and if such action is in the best interest of the United States. Collection from... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Liquidation of collateral. 901.7 Section 901.7 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FEDERAL...

  3. Coronary collateral circulation and its effect on myocardial infarction

    International Nuclear Information System (INIS)

    Fukuyama, Takaya; Ashihara, Toshiaki; Ogata, Ikuo

    1995-01-01

    The purpose of this study was to examine the influence of coronary collateral circulation, which grows after acute myocardial infarction (MI), on infarct size and prognosis. Study subjects were 47 patients who had arteriographic evidence of 99-100% constricture of the infarct-related artery approximately one month after the onset of the first MI. Coronary collateral circulation was analyzed by a four-point scoring (grade 0-3). Furthermore, the patients underwent thallium-201 myocardial imaging one month and two years after the onset to evaluate infarct size. Infarct size was analyzed using extent score (ES) and severity score (SS). ES tended to be decreased during chronic MI stage. Coronary collateral circulation was judged as grade 1 (n=9), grade 2 (n=12), and grade 3 (n=26). There was no difference in infarct size among the three groups. In groups of grades 1 and 2, there was no difference in ES and SS between acute and chronic MI stages. In the group of grade 3, however, ES decreased from 41% to 27% and SS decreased from 68% to 38%, showing remarkable decrease during chronic MI stage. Although coronary collateral circulation one month after the onset is not always responsible for infarct size during acute MI stage, it is considered rsponsible for inhibiting the remodeling of infarction through the long term process. (N.K.)

  4. 7 CFR 762.142 - Servicing related to collateral.

    Science.gov (United States)

    2010-01-01

    ... necessary to properly service the loan. (4) Ensure the borrower does not convert loan security. (5) Ensure... collateral. (b) Partial releases. (1) A lender may release guaranteed loan security without FSA concurrence... applied as extra payments and not as a regular installment on the loan. (ii) The security item will be...

  5. Embolization of nonvariceal portosystemic collaterals in transjugular intrahepatic portosystemic shunts

    International Nuclear Information System (INIS)

    Bilbao, Jose Ignacio; Arias, Mercedes; Longo, Jesus Maria; Alejandre, Pedro Luis; Betes, Maria Teresa; Elizalde, Arlette Maria

    1997-01-01

    Percutaneous embolization of large portosystemic collaterals was performed in three patients following placement of a transjugular intrahepatic portosystemic shunt in order to improve hepatopetal portal flow. Improved hepatic portal perfusion was achieved in these cases, thereby theoretically reducing the risk of chronic hepatic encephalopathy

  6. Collateral and the limits of debt capacity: theory and evidence

    NARCIS (Netherlands)

    Giambona, E.; Mello, A.S.; Riddiough, T.

    2012-01-01

    This paper considers how collateral is used to finance a going concern, and demonstrates with theory and evidence that there are effective limits to debt capacity and the kinds of claims that are issued to deploy that debt capacity. The theory shows that firms with (unobservably) better quality

  7. MAGNETIC FIELD IN ATYPICAL PROMINENCE STRUCTURES: BUBBLE, TORNADO, AND ERUPTION

    Energy Technology Data Exchange (ETDEWEB)

    Levens, P. J.; Labrosse, N. [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Schmieder, B. [LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, 5 place Jules Janssen, F-92195 Meudon (France); López Ariste, A. [IRAP—CNRS UMR 5277, 14, Av. E. Belin, F-31400 Toulouse (France); Dalmasse, K. [CISL/HAO, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 (United States); Gelly, B., E-mail: p.levens.1@research.gla.ac.uk, E-mail: brigitte.schmieder@obspm.fr [CNRS UMR 3718 THEMIS, La Laguna, Tenerife (Spain)

    2016-08-01

    Spectropolarimetric observations of prominences have been obtained with the THEMIS telescope during four years of coordinated campaigns. Our aim is now to understand the conditions of the cool plasma and magnetism in “atypical” prominences, namely when the measured inclination of the magnetic field departs, to some extent, from the predominantly horizontal field found in “typical” prominences. What is the role of the magnetic field in these prominence types? Are plasma dynamics more important in these cases than the magnetic support? We focus our study on three types of “atypical” prominences (tornadoes, bubbles, and jet-like prominence eruptions) that have all been observed by THEMIS in the He i D{sub 3} line, from which the Stokes parameters can be derived. The magnetic field strength, inclination, and azimuth in each pixel are obtained by using the inversion method of principal component analysis on a model of single scattering in the presence of the Hanle effect. The magnetic field in tornadoes is found to be more or less horizontal, whereas for the eruptive prominence it is mostly vertical. We estimate a tendency toward higher values of magnetic field strength inside the bubbles than outside in the surrounding prominence. In all of the models in our database, only one magnetic field orientation is considered for each pixel. While sufficient for most of the main prominence body, this assumption appears to be oversimplified in atypical prominence structures. We should consider these observations as the result of superposition of multiple magnetic fields, possibly even with a turbulent field component.

  8. Collateral Function in Patients with Coronary Occlusion Evaluated by 201Thallium Scintigraphy

    Directory of Open Access Journals (Sweden)

    Aida Hasanović

    2008-11-01

    Full Text Available The present study evaluated the impact of the angiographically documented collaterals on regional myocardial perfusion measured by 201thallium scintigraphy in patients with a chronic total occlusion.The study included 60 patients with chronic total occlusion who underwent rest-stress myocardial perfusion scintigraphy and coronary angiography. All patients had angiographic evidence of coronary collaterals. Patients were divided into two groups: group one had well-developed coronary collateral vessels (n=35 and group II had poor coronary collateral development (n=25.Patients with chronic total occlusion had severe and extensive stress-induced myocardial perfusion defects regardless of the grade of angiographic coronary collaterals. The perfusion defects in the group with good collaterals were predominantly reversible, suggesting that coronary collaterals preserved myocardial viability in the regions subtended by a total coronary occlusion. A significant correlation between good collaterals with complete protection and poor collaterals with no protection was noted.Our results demonstrate a protective effect of collaterals on myocardial perfusion during coronary occlusion. The effective angiographic collaterals may prevent resting regional wall motion abnormalities but do not appear to protect against stress-induced perfusion defect.

  9. Determinants of leptomeningeal collateral flow in stroke patients with a middle cerebral artery occlusion

    International Nuclear Information System (INIS)

    Seeters, Tom van; Velthuis, Birgitta K.; Biessels, Geert Jan; Kappelle, L.J.; Graaf, Yolanda van der

    2016-01-01

    Poor leptomeningeal collateral flow is related to worse clinical outcome in acute ischemic stroke, but the factors that determine leptomeningeal collateral patency are largely unknown. We explored the determinants of leptomeningeal collateral flow and assessed their effect on the relation between leptomeningeal collateral flow and clinical outcome. We included 484 patients from the Dutch acute stroke study (DUST) with a middle cerebral artery (MCA) occlusion. The determinants of poor leptomeningeal collateral flow (≤50 % collateral filling) were identified with logistic regression. We calculated the relative risk (RR) of poor leptomeningeal collateral flow in relation to poor clinical outcome (90-day modified Rankin Scale 3-6) using Poisson regression and assessed whether the determinants of leptomeningeal collateral flow affected this relation. Leptomeningeal collateral flow was poor in 142 patients (29 %). In multivariable analyses, higher admission glucose level (odds ratio (OR) 1.1 per mmol/L increase (95 % CI 1.0-1.2)), a proximal MCA occlusion (OR 1.9 (95 % CI 1.3-3.0)), and an incomplete posterior circle of Willis (OR 1.7 (95 % CI 1.1-2.6)) were independently related to poor leptomeningeal collateral flow. Poor leptomeningeal collateral flow was related to poor clinical outcome (unadjusted RR 1.7 (95 % CI 1.4-2.0)), and this relation was not affected by the determinants of leptomeningeal collateral flow. Our study shows that admission glucose level, a proximal MCA occlusion, and an incomplete ipsilateral posterior circle of Willis are determinants of leptomeningeal collateral flow that represent a combination of congenital, acquired, and acute factors. After adjustment for these determinants, leptomeningeal collateral flow remains related to clinical outcome. (orig.)

  10. De-novo Collateral Formation Following Acute Myocardial Infarction: Dependence on CCR2+ Bone Marrow Cells

    Science.gov (United States)

    Zhang, Hua; Faber, James E

    2015-01-01

    Wide variation exists in the extent (number and diameter) of native pre-existing collaterals in tissues of different strains of mice, with supportive indirect evidence recently appearing for humans. This variation is a major determinant of the wide variation in severity of tissue injury in occlusive vascular disease. Whether such genetic-dependent variation also exists in the heart is unknown because no model exists for study of mouse coronary collaterals. Also owing to methodological limitations, it is not known if ischemia can induce new coronary collaterals to form (“neo-collaterals”) versus remodeling of pre-existing ones. The present study sought to develop a model to study coronary collaterals in mice, determine whether neo-collateral formation occurs, and investigate the responsible mechanisms. Four strains with known rank-ordered differences in collateral extent in brain and skeletal muscle were studied: C57BLKS>C57BL/6>A/J>BALB/c. Unexpectedly, these and 5 additional strains lacked native coronary collaterals. However after ligation, neo-collaterals formed rapidly within 1-to-2 days, reaching their maximum extent in ≤ 7 days. Rank-order for neo-collateral formation differed from the above: C57BL/6>BALB/c>C57BLKS>A/J. Collateral network conductance, infarct volume−1, and contractile function followed this same rank-order. Neo-collateral formation and collateral conductance were reduced and infarct volume increased in MCP1−/− and CCR2−/− mice. Bone-marrow transplant rescued collateral formation in CCR2−/− mice. Involvement of fractalkine→CX3CR1 signaling and endothelial cell proliferation were also identified. This study introduces a model for investigating the coronary collateral circulation in mice, demonstrates that neocollaterals form rapidly after coronary occlusion, and finds that MCP→CCR2-mediated recruitment of myeloid cells is required for this process. PMID:26254180

  11. Determinants of leptomeningeal collateral flow in stroke patients with a middle cerebral artery occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Seeters, Tom van; Velthuis, Birgitta K. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Biessels, Geert Jan; Kappelle, L.J. [University Medical Center Utrecht, Department of Neurology, Brain Center Rudolf Magnus, Utrecht (Netherlands); Graaf, Yolanda van der [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); Collaboration: on behalf of the Dutch acute stroke study (DUST) investigators

    2016-10-15

    Poor leptomeningeal collateral flow is related to worse clinical outcome in acute ischemic stroke, but the factors that determine leptomeningeal collateral patency are largely unknown. We explored the determinants of leptomeningeal collateral flow and assessed their effect on the relation between leptomeningeal collateral flow and clinical outcome. We included 484 patients from the Dutch acute stroke study (DUST) with a middle cerebral artery (MCA) occlusion. The determinants of poor leptomeningeal collateral flow (≤50 % collateral filling) were identified with logistic regression. We calculated the relative risk (RR) of poor leptomeningeal collateral flow in relation to poor clinical outcome (90-day modified Rankin Scale 3-6) using Poisson regression and assessed whether the determinants of leptomeningeal collateral flow affected this relation. Leptomeningeal collateral flow was poor in 142 patients (29 %). In multivariable analyses, higher admission glucose level (odds ratio (OR) 1.1 per mmol/L increase (95 % CI 1.0-1.2)), a proximal MCA occlusion (OR 1.9 (95 % CI 1.3-3.0)), and an incomplete posterior circle of Willis (OR 1.7 (95 % CI 1.1-2.6)) were independently related to poor leptomeningeal collateral flow. Poor leptomeningeal collateral flow was related to poor clinical outcome (unadjusted RR 1.7 (95 % CI 1.4-2.0)), and this relation was not affected by the determinants of leptomeningeal collateral flow. Our study shows that admission glucose level, a proximal MCA occlusion, and an incomplete ipsilateral posterior circle of Willis are determinants of leptomeningeal collateral flow that represent a combination of congenital, acquired, and acute factors. After adjustment for these determinants, leptomeningeal collateral flow remains related to clinical outcome. (orig.)

  12. A STATISTICAL STUDY OF TRANSVERSE OSCILLATIONS IN A QUIESCENT PROMINENCE

    Energy Technology Data Exchange (ETDEWEB)

    Hillier, A. [Kwasan and Hida Observatories, Kyoto University, Kyoto 607-8471 (Japan); Morton, R. J. [Mathematics and Information Science, Northumbria University, Pandon Building, Camden Street, Newcastle upon Tyne NE1 8ST (United Kingdom); Erdélyi, R., E-mail: andrew@kwasan.kyoto-u.ac.jp [Solar Physics and Space Plasma Research Centre (SP2RC), University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

    2013-12-20

    The launch of the Hinode satellite has allowed for seeing-free observations at high-resolution and high-cadence making it well suited to study the dynamics of quiescent prominences. In recent years it has become clear that quiescent prominences support small-amplitude transverse oscillations, however, sample sizes are usually too small for general conclusions to be drawn. We remedy this by providing a statistical study of transverse oscillations in vertical prominence threads. Over a 4 hr period of observations it was possible to measure the properties of 3436 waves, finding periods from 50 to 6000 s with typical velocity amplitudes ranging between 0.2 and 23 km s{sup –1}. The large number of observed waves allows the determination of the frequency dependence of the wave properties and derivation of the velocity power spectrum for the transverse waves. For frequencies less than 7 mHz, the frequency dependence of the velocity power is consistent with the velocity power spectra generated from observations of the horizontal motions of magnetic elements in the photosphere, suggesting that the prominence transverse waves are driven by photospheric motions. However, at higher frequencies the two distributions significantly diverge, with relatively more power found at higher frequencies in the prominence oscillations. These results highlight that waves over a large frequency range are ubiquitous in prominences, and that a significant amount of the wave energy is found at higher frequency.

  13. A STATISTICAL STUDY OF TRANSVERSE OSCILLATIONS IN A QUIESCENT PROMINENCE

    International Nuclear Information System (INIS)

    Hillier, A.; Morton, R. J.; Erdélyi, R.

    2013-01-01

    The launch of the Hinode satellite has allowed for seeing-free observations at high-resolution and high-cadence making it well suited to study the dynamics of quiescent prominences. In recent years it has become clear that quiescent prominences support small-amplitude transverse oscillations, however, sample sizes are usually too small for general conclusions to be drawn. We remedy this by providing a statistical study of transverse oscillations in vertical prominence threads. Over a 4 hr period of observations it was possible to measure the properties of 3436 waves, finding periods from 50 to 6000 s with typical velocity amplitudes ranging between 0.2 and 23 km s –1 . The large number of observed waves allows the determination of the frequency dependence of the wave properties and derivation of the velocity power spectrum for the transverse waves. For frequencies less than 7 mHz, the frequency dependence of the velocity power is consistent with the velocity power spectra generated from observations of the horizontal motions of magnetic elements in the photosphere, suggesting that the prominence transverse waves are driven by photospheric motions. However, at higher frequencies the two distributions significantly diverge, with relatively more power found at higher frequencies in the prominence oscillations. These results highlight that waves over a large frequency range are ubiquitous in prominences, and that a significant amount of the wave energy is found at higher frequency

  14. Change in the collateral and accessory collateral ligament lengths of the proximal interphalangeal joint using cadaveric model three-dimensional laser scanning.

    Science.gov (United States)

    Sandhu, S S; Dreckmann, S; Binhammer, P A

    2016-05-01

    The purpose of this study was to assess the lengths of the index and middle finger proximal interphalangeal joint ligaments and determine the relative changes in the collateral and accessory collateral ligament lengths at 0°, 45° and 90° flexion. We generated three-dimensional scans of 16 finger (eight index and eight middle) proximal interphalangeal joints to assess relative changes in ligament length. Significant changes were found between 45°-90° and 0°-90° for the ulnar collateral ligament of the index finger and both collateral ligaments of the middle finger between 45°-90° and 0°-90°. No significant changes in length were found for the radial collateral ligament of the index finger or the accessory collateral ligaments of the index and middle fingers. Overall, it was found that the collateral ligament length changed significantly, but there was no significant change in the accessory collateral ligaments. Therapeutic IV. © The Author(s) 2015.

  15. Medial collateral ligament healing one year after a concurrent medial collateral ligament and anterior cruciate ligament injury: an interdisciplinary study in rabbits.

    Science.gov (United States)

    Yamaji, T; Levine, R E; Woo, S L; Niyibizi, C; Kavalkovich, K W; Weaver-Green, C M

    1996-03-01

    The optimal treatment for concurrent injuries to the medial collateral and anterior cruciate ligaments has not been determined, despite numerous clinical and laboratory studies. The objective of this study was to examine the effect of surgical repair of the medial collateral ligament on its biomechanical and biochemical properties 52 weeks after such injuries. In the left knee of 12 skeletally mature New Zealand White rabbits, the medial collateral ligament was torn and the anterior cruciate ligament was transected and then reconstructed. This is an experimental model previously developed in our laboratory. In six rabbits, the torn ends of the medial collateral ligament were repaired, and in the remaining six rabbits, the ligament was not repaired. Fifty-two weeks after injury, we examined varus-valgus and anterior-posterior knee stability; structural properties of the femur-medial collateral ligament-tibia complex; and mechanical properties, collagen content, and mature collagen crosslinking of the medial collateral ligament. We could not detect significant differences between repair and nonrepair groups for any biomechanical or biochemical property. Our data support clinical findings that when the medial collateral and anterior cruciate ligaments are injured concurrently and the anterior cruciate ligament is reconstructed, conservative treatment of the ruptured medial collateral ligament can result in successful healing.

  16. Status of systemic to pulmonary arterial collateral flow after the fontan procedure.

    Science.gov (United States)

    Whitehead, Kevin K; Harris, Matthew A; Glatz, Andrew C; Gillespie, Matthew J; DiMaria, Michael V; Harrison, Neil E; Dori, Yoav; Keller, Marc S; Rome, Jonathan J; Fogel, Mark A

    2015-06-15

    The investigators recently validated a method of quantifying systemic-to-pulmonary arterial collateral flow using phase-contrast magnetic resonance imaging velocity mapping. Cross-sectional data suggest decreased collateral flow in patients with total cavopulmonary connections (TCPCs) compared with those with superior cavopulmonary connections (SCPCs). However, no studies have examined serial changes in collateral flow from SCPCs to TCPCs in the same patients. The aim of this study was to examine differences in collateral flow between patients with SCPCs and those with TCPCs. Collateral flow was quantified by 2 independent measures from 250 single-ventricle studies in 219 different patients (115 SCPC and 135 TCPC studies, 31 patients with both) and 18 controls, during routine studies using through-plane phase-contrast magnetic resonance imaging. Collateral flow was indexed to body surface area, aortic flow, and pulmonary venous flow. Regardless of indexing method, SCPC patients had significantly higher collateral flow than TCPC patients (1.64 ± 0.8 vs 1.03 ± 0.8 L/min/m(2), p <0.001). In 31 patients who underwent serial examinations, collateral flow as a fraction of aortic flow increased early after TCPC completion. In TCPC patients, indexed collateral flow demonstrated a significant negative correlation with time from TCPC. In conclusion, SCPC and TCPC patients demonstrate substantial collateral flow, with SCPC patients having higher collateral flow than TCPC patients overall. On the basis of the paired subset analysis, collateral flow does not decrease in the short term after TCPC completion and trends toward an increase. In the long term, however, collateral flow decreases over time after TCPC completion. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Impact of collateral circulation on early outcome and risk of hemorrhagic complications after systemic thrombolysis.

    Science.gov (United States)

    Brunner, Freimuth; Tomandl, Bernd; Hanken, Katrin; Hildebrandt, Helmut; Kastrup, Andreas

    2014-12-01

    In stroke patients, collateral flow can rapidly be assessed on computed tomography angiography (CTA). In this study, the impact of baseline collaterals on early outcome and risk of symptomatic intracerebral hemorrhages after systemic thrombolysis in patients with proximal arterial occlusions within the anterior circulation were analyzed. Collateralization scores were determined on the CT angiography source images (0 = absent; 1 ≤ 50%, 2 > 50% but collateral filling) of patients with distal intracranial carotid artery and/or M1 segment occlusions treated from 2008 to December 2011. A collateral score of 0 to 1 was designated as poor and 2 to 3 as good collateral vessel status. Outcome variables included in hospital mortality, favorable outcome at discharge (modified Rankin score ≤ 2), and rates of symptomatic intracerebral hemorrhage based on the European-Australasian Acute Stroke Study II definition. Among 246 subjects (mean age of 74 years; median National Institutes of Health Stroke Scale N at admission 14), 205 patients (83%) had good collaterals, whereas 41 patients (17%) had poor collaterals, respectively. Patients with poor collaterals had significantly higher rates of in-hospital mortality (41% vs. 12%, P collaterals. The grade of collateralization was independently associated with in-hospital mortality (P collaterals have a poor early functional outcome and high rates of symptomatic intracerebral hemorrhage after systemic thrombolysis. Since similar findings have also been reported after endovascular therapy, strategies to improve collateral blood flow should be assessed in this patient population. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

  18. Collateral circulation on perfusion-computed tomography-source images predicts the response to stroke intravenous thrombolysis.

    Science.gov (United States)

    Calleja, A I; Cortijo, E; García-Bermejo, P; Gómez, R D; Pérez-Fernández, S; Del Monte, J M; Muñoz, M F; Fernández-Herranz, R; Arenillas, J F

    2013-05-01

    Perfusion-computed tomography-source images (PCT-SI) may allow a dynamic assessment of leptomeningeal collateral arteries (LMC) filling and emptying in middle cerebral artery (MCA) ischaemic stroke. We described a regional LMC scale on PCT-SI and hypothesized that a higher collateral score would predict a better response to intravenous (iv) thrombolysis. We studied consecutive ischaemic stroke patients with an acute MCA occlusion documented by transcranial Doppler/transcranial color-coded duplex, treated with iv thrombolysis who underwent PCT prior to treatment. Readers evaluated PCT-SI in a blinded fashion to assess LMC within the hypoperfused MCA territory. LMC scored as follows: 0, absence of vessels; 1, collateral supply filling ≤ 50%; 2, between> 50% and < 100%; 3, equal or more prominent when compared with the unaffected hemisphere. The scale was divided into good (scores 2-3) vs. poor (scores 0-1) collaterals. The predetermined primary end-point was a good 3-month functional outcome, while early neurological recovery, transcranial duplex-assessed 24-h MCA recanalization, 24-h hypodensity volume and hemorrhagic transformation were considered secondary end-points. Fifty-four patients were included (55.5% women, median NIHSS 10), and 4-13-23-14 patients had LMC score (LMCs) of 0-1-2-3, respectively. The probability of a good long-term outcome augmented gradually with increasing LMCs: (0) 0%; (1) 15.4%; (2) 65.2%; (3) 64.3%, P = 0.004. Good-LMCs was independently associated with a good outcome [OR 21.02 (95% CI 2.23-197.75), P = 0.008]. Patients with good LMCs had better early neurological recovery (P = 0.001), smaller hypodensity volumes (P < 0.001) and a clear trend towards a higher recanalization rate. A higher degree of LMC assessed by PCT-SI predicts good response to iv thrombolysis in MCA ischaemic stroke patients. © 2012 The Author(s) European Journal of Neurology © 2012 EFNS.

  19. Two Categories of Apparent Tornado-like Prominences

    Science.gov (United States)

    Martin, Sara F.; Venkataramanasastry, Aparna

    2014-06-01

    Two categories of solar prominences have been described in the literature as having a pattern of mass motions and/or a shape similar to terrestrial tornados. We first identify the two categories associated with prominences in the historic literature and then show that counterparts do exist for both in recent literature but one has not been called a tornado prominence. One category described as being similar to tornados is associated with the barbs of quiescent filaments but barbs appear to have rotational motion only under special conditions. H alpha Doppler observations from Helio Research confirm that this category is an illusion in our mind’s eye resulting from counterstreaming in the large barbs of quiescent filaments. The second category is a special case of rotational motion occurring during the early stages of some erupting prominences, in recent years called the roll effect in erupting prominences. In these cases, the eruption begins with the sideways rolling of the top of a prominence. As the eruption proceeds the rolling motion propagates down one leg or both legs of an erupting prominence depending on whether the eruption is asymmetric or symmetric respectively. As an asymmetric eruption proceeds, the longer lasting leg becomes nearly vertical and has true rotational motion. If only this phase of the eruption was observed, as in the historic cases, it was called a tornado prominence and spectra recorded in these cases provide proof of the rotational motion. When one observes an entire eruption which exhibits the rolling motion, as accomplished at Helio Research, the similarity to a tornado is lost because the event as a whole has quite a different nature and the analogy to a terrestrial tornado not longer appears suitable or helpful in understanding the observed and deduced physical processes. Our conclusion is that there are no solar prominences with motions that are usefully described as tornado or tornado-like events aside from the fun of observing

  20. Collateral Composition, Diversification Risk, and Systemically Important Merchant Banks

    Czech Academy of Sciences Publication Activity Database

    Derviz, Alexis

    2014-01-01

    Roč. 14, Special Issue (2014), s. 23-34 ISSN 1572-3089 R&D Projects: GA ČR GA13-11983S Institutional support: RVO:67985556 Keywords : collateral * systemic risk * merchant bank * CoCo Subject RIV: AH - Economics Impact factor: 1.506, year: 2014 http://library.utia.cas.cz/separaty/2014/E/derviz-0433271.pdf

  1. Multidetector CT portal venography in evaluation of portosystemic collateral vessels

    International Nuclear Information System (INIS)

    Agarwal, A.; Jain, M.

    2008-01-01

    This essay shows the usefulness of multidetector CT angiography for evaluation of the splenoportal venous system, which is essential in the management of patients with portal hypertension and its complications, such as portal vein thrombosis. By providing scanning with reconstruction of thin axial source images and reformatting into thicker multiplanar reformats, multidetector CT can help to determine the extent and location of portosystemic collateral vessels in patients with portal hypertension and is probably the optimal imaging technique in this setting.

  2. Collateral Optimization : Liquidity & Funding Value Adjustments, - Best Practices -

    OpenAIRE

    Genest, Benoit; Rego, David; Freon, Helene

    2013-01-01

    The purpose of this paper is to understand how the current financial landscape shaped by the crises and new regulations impacts Investment Banking’s business model. We will focus on quantitative implications, i.e. valuation, modeling and pricing issues, as well as qualitative implications, i.e. best practices to manage quantitative aspects and handle these functions to the current Investment Banking organization. We considered two pillars to shape our vision of collateral optimization: ...

  3. Functional anatomy of the lateral collateral ligament of the elbow.

    Science.gov (United States)

    Hackl, M; Bercher, M; Wegmann, K; Müller, L P; Dargel, J

    2016-07-01

    The aim of this study was to analyze the functional anatomy of the lateral collateral ligament complex (LCLC) and the surrounding forearm extensors. Using 81 human cadaveric upper extremities, the anatomy of the forearm extensors-especially the anconeus, supinator and extensor carpi ulnaris (ECU)-was analyzed. After removal of aforementioned extensors the functional anatomy of the LCLC was analyzed. The origin of the LCLC was evaluated for isometry. The insertion types of the lateral ulnar collateral ligament (LUCL) were analyzed and classified. The ECU runs parallel to the RCL to dynamically preserve varus stability. The supinator and anconeus muscle fibers coalesce with the LCLC and lengthen during pronation. The anconeus fibers run parallel to the LUCL in full flexion. The LCLC consists of the annular ligament (AL) and the isometric radial collateral ligament (RCL). During elbow flexion, its posterior branches (LUCL) tighten while the anterior branches loosen. When performing a pivot shift test, the loosened LUCL fibers do not fully tighten in full extension. The LUCL inserts along with the AL at the supinator crest. Three different insertion types could be observed. The LUCL represents the posterior branch of the RCL rather than a distinct ligament. It is non-isometric and lengthens during elbow flexion. The RCL was found to be of vital importance for neutralization of posterolateral rotatory forces. Pronation of the forearm actively stabilizes the elbow joint as the supinator, anconeus and biceps muscle work in unison to increase posterolateral rotatory stability.

  4. ON THE MAGNETISM AND DYNAMICS OF PROMINENCE LEGS HOSTING TORNADOES

    International Nuclear Information System (INIS)

    Martínez González, M. J.; Ramos, A. Asensio; Arregui, I.; Collados, M.; Beck, C.; Rodríguez, J. de la Cruz

    2016-01-01

    Solar tornadoes are dark vertical filamentary structures observed in the extreme ultraviolet associated with prominence legs and filament barbs. Their true nature and relationship to prominences requires an understanding of their magnetic structure and dynamic properties. Recently, a controversy has arisen: is the magnetic field organized forming vertical, helical structures or is it dominantly horizontal? And concerning their dynamics, are tornadoes really rotating or is it just a visual illusion? Here we analyze four consecutive spectro-polarimetric scans of a prominence hosting tornadoes on its legs, which helps us shed some light on their magnetic and dynamical properties. We show that the magnetic field is very smooth in all the prominence, which is probably an intrinsic property of the coronal field. The prominence legs have vertical helical fields that show slow temporal variation that is probably related to the motion of the fibrils. Concerning the dynamics, we argue that (1) if rotation exists, it is intermittent, lasting no more than one hour, and (2) the observed velocity pattern is also consistent with an oscillatory velocity pattern (waves).

  5. ON THE MAGNETISM AND DYNAMICS OF PROMINENCE LEGS HOSTING TORNADOES

    Energy Technology Data Exchange (ETDEWEB)

    Martínez González, M. J.; Ramos, A. Asensio; Arregui, I.; Collados, M. [Instituto de Astrofísica de Canarias, Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain); Beck, C. [National Solar Observatory, Sacramento Peak P.O. Box 62, Sunspot, NM 88349 (United States); Rodríguez, J. de la Cruz [Institute for Solar Physics, Department of Astronomy, Stockholm University, Albanova University Center, SE-10691 Stockholm (Sweden)

    2016-07-10

    Solar tornadoes are dark vertical filamentary structures observed in the extreme ultraviolet associated with prominence legs and filament barbs. Their true nature and relationship to prominences requires an understanding of their magnetic structure and dynamic properties. Recently, a controversy has arisen: is the magnetic field organized forming vertical, helical structures or is it dominantly horizontal? And concerning their dynamics, are tornadoes really rotating or is it just a visual illusion? Here we analyze four consecutive spectro-polarimetric scans of a prominence hosting tornadoes on its legs, which helps us shed some light on their magnetic and dynamical properties. We show that the magnetic field is very smooth in all the prominence, which is probably an intrinsic property of the coronal field. The prominence legs have vertical helical fields that show slow temporal variation that is probably related to the motion of the fibrils. Concerning the dynamics, we argue that (1) if rotation exists, it is intermittent, lasting no more than one hour, and (2) the observed velocity pattern is also consistent with an oscillatory velocity pattern (waves).

  6. Solar Tornado Prominences: Plasma Motions Along Filament Barbs

    Science.gov (United States)

    Panasenco, Olga; Velli, Marco; Martin, Sara F.; Rappazzo, Franco

    2013-03-01

    Recent high-resolution observations from the Solar Dynamic Observatory (SDO) have reawakened interest in the old and fascinating phenomenon of solar tornado prominences. This class of prominences was first introduced by E. Pettit in 1932, who studied them over many years up to 1950. High resolution and high cadence multi-wavelength data obtained by SDO reveal that the tornado-like properties of these prominences are mainly an illusion due to projection effects. We show that counterstreaming plasma motions with projected velocities up to +/- 45 km/sec along the prominence spine and barbs create a tornado-like impression when viewed at the limb. We demonstrate that barbs are often rooted at the intersection between 4-5 supergranular cells. We discuss the observed oscillations along the vertical parts of barbs and whether they may be related to vortex flows coming from the convection downdrafts at the intersection of supergranules (and possibly smaller convective cells) in the photosphere and their entrained magnetic field. The unwinding of magnetic threads near the photosphere via reconnection might be a source of the waves which are observed as oscillations in prominence barbs.

  7. Collateral Ligament Knee Injuries in Pediatric and Adolescent Athletes.

    Science.gov (United States)

    Kramer, Dennis E; Miller, Patricia E; Berrahou, Iman K; Yen, Yi-Meng; Heyworth, Benton E

    2017-12-08

    The majority of research on medial (MCL) and lateral (LCL) collateral ligament injuries has focused on adults and combined collateral/cruciate injuries. The purpose of this study was to determine characteristics associated with isolated collateral ligament injuries in adolescents, and assess timing for return to sports. Electronic medical records were queried to identify patients aged below 17 years who sustained a magnetic resonance imaging-confirmed isolated MCL or LCL injury over an 8-year period. Retrospective review then documented patient and injury characteristics and clinical course. General linear modeling was used to analyze risk factors for prolonged return to sports, continued pain or reinjury. Fifty-one knees (33 in males, 65%), mean age 13.8 years (range, 5 to 17), were identified, of which 40 (78%) had MCL injuries. Over half (29, 57%) of knees had an open distal femoral physis including all 5 bony avulsion injuries. Eleven (22%) had LCL injuries of which 3 (6%) had concurrent posterolateral corner injuries. Forty-two (82%) knees had injuries that occurred during sports. Eleven knees (28%) with MCL tears had a simultaneous patellar instability episode. Knee injuries that occurred during sports had 37% shorter recovery time (P=0.02). Eight knees (16%) experienced a reinjury and 12 (24%) were followed over an extended period of time for various knee issues. Football injuries were more likely to be grade 3 (P=0.03), and football and soccer accounted for all grade III injuries. The mean return to sports was 2.2 months, with grade III cases returning at 2.4 months, and 95% of cases within 4 months. Isolated collateral ligament injuries are rare in adolescent athletes. MCL injuries, one-quarter of which occurred in conjunction with patellar instability events, were 4 times more common than LCL injuries, one quarter of which have other posterolateral corner structures involved. Grade III injuries represent 20% to 25% of collateral ligament injuries and

  8. Cerebral collateral therapeutics in acute ischemic stroke: A randomized preclinical trial of four modulation strategies.

    Science.gov (United States)

    Beretta, Simone; Versace, Alessandro; Carone, Davide; Riva, Matteo; Dell'Era, Valentina; Cuccione, Elisa; Cai, Ruiyao; Monza, Laura; Pirovano, Silvia; Padovano, Giada; Stiro, Fabio; Presotto, Luca; Paternò, Giovanni; Rossi, Emanuela; Giussani, Carlo; Sganzerla, Erik P; Ferrarese, Carlo

    2017-10-01

    Cerebral collaterals are dynamically recruited after arterial occlusion and highly affect tissue outcome in acute ischemic stroke. We investigated the efficacy and safety of four pathophysiologically distinct strategies for acute modulation of collateral flow (collateral therapeutics) in the rat stroke model of transient middle cerebral artery (MCA) occlusion. A composed randomization design was used to assign rats (n = 118) to receive phenylephrine (induced hypertension), polygeline (intravascular volume load), acetazolamide (cerebral arteriolar vasodilation), head down tilt (HDT) 15° (cerebral blood flow diversion), or no treatment, starting 30 min after MCA occlusion. Compared to untreated animals, treatment with collateral therapeutics was associated with lower infarct volumes (62% relative mean difference; 51.57 mm 3 absolute mean difference; p Collateral therapeutics acutely increased cerebral perfusion in the medial (+40.8%; p collaterals is feasible and provides a tissue-saving effect in the hyperacute phase of ischemic stroke prior to recanalization therapy.

  9. Collateral findings during computed tomography scan for atrial fibrillation ablation: Let's take a look around.

    Science.gov (United States)

    Perna, Francesco; Casella, Michela; Narducci, Maria Lucia; Dello Russo, Antonio; Bencardino, Gianluigi; Pontone, Gianluca; Pelargonio, Gemma; Andreini, Daniele; Vitulano, Nicola; Pizzamiglio, Francesca; Conte, Edoardo; Crea, Filippo; Tondo, Claudio

    2016-04-26

    The growing number of atrial fibrillation catheter ablation procedures warranted the development of advanced cardiac mapping techniques, such as image integration between electroanatomical map and cardiac computed tomography. While scanning the chest before catheter ablation, it is frequent to detect cardiac and extracardiac collateral findings. Most collateral findings are promptly recognized as benign and do not require further attention. However, sometimes clinically relevant collateral findings are detected, which often warrant extra diagnostic examinations or even invasive procedure, and sometimes need to be followed-up over time. Even though reporting and further investigating collateral findings has not shown a clear survival benefit, almost all the working groups providing data on collateral findings reported some collateral findings eventually coming out to be malignancies, sometimes at an early stage. Therefore, there is currently no clear agreement about the right strategy to be followed.

  10. Usefulness of computed tomography (CT) in the diagnosis of portosystemic collaterals in liver cirrhosis

    International Nuclear Information System (INIS)

    Tsukune, Yoshihiko

    1984-01-01

    This study assesses the usefulness of computed tomography (CT) in the diagnosis of portosystemic collaterals in liver cirrhosis. Seventy-eight patients with liver cirrhosis underwent both CT and angiography. Comparison was made between CT and angiography on eleven types of collaterals, and many of them were demonstrated on CT scans better than angio. Especially, esophageal varices, paraesophageal varices, umbilical pathway and caput medusa were diagnostic on CT scans. Gastrorenal collaterals, splenorenal collaterals, retroperitoneal pathway are also well demonstrated. Dilatation of azygos systems and small veins in the liver surface are only observed on CT scans. However, coronary varices and short gastric varices are well diagnostic in angiography. But considering all types of collaterals, it was stressed that angiography can be eliminated by CT in evaluation of collaterals in liver cirrhosis. (author)

  11. Coronary collateralization shows sex and racial-ethnic differences in obstructive artery disease patients.

    Directory of Open Access Journals (Sweden)

    Zhi Liu

    Full Text Available Coronary collateral circulation protects cardiac tissues from myocardial infarction damage and decreases sudden cardiac death. So far, it is unclear how coronary collateralization varies by race-ethnicity groups and by sex.We assessed 868 patients with obstructive CAD. Patients were assessed for collateral grades based on Rentrop grading system, as well as other covariates. DNA samples were genotyped using the Affymetrix 6.0 genotyping array. To evaluate genetic contributions to collaterals, we performed admixture mapping using logistic regression with estimated local and global ancestry.Overall, 53% of participants had collaterals. We found difference between sex and racial-ethnic groups. Men had higher rates of collaterals than women (P-value = 0.000175. White Hispanics/Latinos showed overall higher rates of collaterals than African Americans and non-Hispanic Whites (59%, 50% and 48%, respectively, P-value = 0.017, and especially higher rates in grade 1 and grade 3 collateralization than the other two populations (P-value = 0.0257. Admixture mapping showed Native American ancestry was associated with the presence of collaterals at a region on chromosome 17 (chr17:35,243,142-41,251,931, β = 0.55, P-value = 0.000127. African ancestry also showed association with collaterals at a different region on chromosome 17 (chr17: 32,266,966-34,463,323, β = 0.38, P-value = 0.00072.In our study, collateralization showed sex and racial-ethnic differences in obstructive CAD patients. We identified two regions on chromosome 17 that were likely to harbor genetic variations that influenced collateralization.

  12. Improved evaluation of the coronary collateral circulation measuring the regional blood flow with 133Xe

    International Nuclear Information System (INIS)

    Franz, N.; Strangfeld, D.; Romaniuk, P.; Heublein, B.

    1988-01-01

    In 40 patients with angina pectoris catheter diagnostic measurements of the myocardial flow were carried out after intracoronary application of 133 Xe at rest and after oral application of Curantyl in order to obtain a better evaluation of coronary collaterals. The results show relations between angiographically detected coronary collaterals and the reduced coronary reserve. A quantitative measurement of collaterals from the angiogram facilitates a more precise evaluation of the relation between coronary sclerosis and myocardial flow. (author)

  13. Associations Between Collateral Status and Thrombus Characteristics and Their Impact in Anterior Circulation Stroke.

    Science.gov (United States)

    Alves, Heitor C; Treurniet, Kilian M; Dutra, Bruna G; Jansen, Ivo G H; Boers, Anna M M; Santos, Emilie M M; Berkhemer, Olvert A; Dippel, Diederik W J; van der Lugt, Aad; van Zwam, Wim H; van Oostenbrugge, Robert J; Lingsma, Hester F; Roos, Yvo B W E M; Yoo, Albert J; Marquering, Henk A; Majoie, Charles B L M

    2018-02-01

    Thrombus characteristics and collateral score are associated with functional outcome in patients with acute ischemic stroke. It has been suggested that they affect each other. The aim of this study is to evaluate the association between clot burden score, thrombus perviousness, and collateral score and to determine whether collateral score influences the association of thrombus characteristics with functional outcome. Patients with baseline thin-slice noncontrast computed tomography and computed tomographic angiography images from the MR CLEAN trial (Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands) were included (n=195). Collateral score and clot burden scores were determined on baseline computed tomographic angiography. Thrombus attenuation increase was determined by comparing thrombus density on noncontrast computed tomography and computed tomographic angiography using a semiautomated method. The association of collateral score with clot burden score and thrombus attenuation increase was evaluated with linear regression. Mediation and effect modification analyses were used to assess the influence of collateral score on the association of clot burden score and thrombus attenuation increase with functional outcome. A higher clot burden score (B=0.063; 95% confidence interval, 0.008-0.118) and a higher thrombus attenuation increase (B=0.014; 95% confidence interval, 0.003-0.026) were associated with higher collateral score. Collateral score mediated the association of clot burden score with functional outcome. The association between thrombus attenuation increase and functional outcome was modified by the collateral score, and this association was stronger in patients with moderate and good collaterals. Patients with lower thrombus burden and higher thrombus perviousness scores had higher collateral score. The positive effect of thrombus perviousness on clinical outcome was only present in patients with

  14. Reconnection–Condensation Model for Solar Prominence Formation

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, Takafumi [Institute for Space-Earth Environmental Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601 (Japan); Yokoyama, Takaaki, E-mail: kaneko@isee.nagoya-u.ac.jp [Department of Earth and Planetary Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2017-08-10

    We propose a reconnection–condensation model in which topological change in a coronal magnetic field via reconnection triggers radiative condensation, thereby resulting in prominence formation. Previous observational studies have suggested that reconnection at a polarity inversion line of a coronal arcade field creates a flux rope that can sustain a prominence; however, they did not explain the origin of cool dense plasmas of prominences. Using three-dimensional magnetohydrodynamic simulations, including anisotropic nonlinear thermal conduction and optically thin radiative cooling, we demonstrate that reconnection can lead not only to flux rope formation but also to radiative condensation under a certain condition. In our model, this condition is described by the Field length, which is defined as the scale length for thermal balance between radiative cooling and thermal conduction. This critical condition depends weakly on the artificial background heating. The extreme ultraviolet emissions synthesized with our simulation results have good agreement with observational signatures reported in previous studies.

  15. Static current-sheet models of quiescent prominences

    Science.gov (United States)

    Wu, F.; Low, B. C.

    1986-12-01

    A particular class of theoretical models idealize the prominence to be a discrete flat electric-current sheet suspended vertically in a potential magnetic field. The weight of the prominence is supported by the Lorentz force in the current sheet. These models can be extended to have curved electric-current sheets and to vary three-dimensionally. The equation for force balance is 1 over 4 pi (del times B) times Bdel p- p9 z=zero. Using Cartesian coordinates we take, for simplicity, a uniform gravity with constant acceleration g in the direction -z. If we are interested not in the detailed internal structure of the prominence, but in the global magnetic configuration around the prominence, we may take prominence plasma to be cold. Consideration is given to how such equilibrium states can be constructed. To simplify the mathematical problem, suppose there is no electric current in the atmosphere except for the discrete currents in the cold prominence sheet. Let us take the plane z =0 to be the base of the atmosphere and restrict our attention to the domain z greater than 0. The task we have is to solve for a magnetic field which is everywhere potential except on some free surface S, subject to suit able to boundary conditions. The surface S is determined by requiring that it possesses a discrete electric current density such that the Lorentz force on it is everywhere vertically upward to balance the weight of the material m(S). Since the magnetic field is potential in the external atmosphere, the latter is decoupled from the magnetic field and its plane parallel hydrostatic pressure and density can be prescribed.

  16. Solar Prominence Modelling and Plasma Diagnostics at ALMA Wavelengths

    Science.gov (United States)

    Rodger, Andrew; Labrosse, Nicolas

    2017-09-01

    Our aim is to test potential solar prominence plasma diagnostics as obtained with the new solar capability of the Atacama Large Millimeter/submillimeter Array (ALMA). We investigate the thermal and plasma diagnostic potential of ALMA for solar prominences through the computation of brightness temperatures at ALMA wavelengths. The brightness temperature, for a chosen line of sight, is calculated using the densities of electrons, hydrogen, and helium obtained from a radiative transfer code under non-local thermodynamic equilibrium (non-LTE) conditions, as well as the input internal parameters of the prominence model in consideration. Two distinct sets of prominence models were used: isothermal-isobaric fine-structure threads, and large-scale structures with radially increasing temperature distributions representing the prominence-to-corona transition region. We compute brightness temperatures over the range of wavelengths in which ALMA is capable of observing (0.32 - 9.6 mm), however, we particularly focus on the bands available to solar observers in ALMA cycles 4 and 5, namely 2.6 - 3.6 mm (Band 3) and 1.1 - 1.4 mm (Band 6). We show how the computed brightness temperatures and optical thicknesses in our models vary with the plasma parameters (temperature and pressure) and the wavelength of observation. We then study how ALMA observables such as the ratio of brightness temperatures at two frequencies can be used to estimate the optical thickness and the emission measure for isothermal and non-isothermal prominences. From this study we conclude that for both sets of models, ALMA presents a strong thermal diagnostic capability, provided that the interpretation of observations is supported by the use of non-LTE simulation results.

  17. Prominent crista terminalis mimicking a right atrial mass: case report

    Directory of Open Access Journals (Sweden)

    Lange Peter

    2010-10-01

    Full Text Available Abstract The crista terminalis is a normal anatomical structure within the right atrium that is not normally visualised in the standard views obtained while performing a transthoracic echocardiogram. In this case report, transthoracic echocardiography suggested the presence of a right atrial mass in a patient with end stage renal disease. However, subsequent transesophageal echocardiography revealed that the right atrial mass was actually a thick muscular bridge in the right atrium consistent with a prominent crista terminalis. An understanding of the anatomy and the echocardiographic appearance of a prominent crista terminalis will minimize the misdiagnosis of this structure avoiding unnecessary expensive additional tests.

  18. Monocytic microRNA profile associated with coronary collateral artery function in chronic total occlusion patients.

    Science.gov (United States)

    Hakimzadeh, Nazanin; Elias, Joëlle; Wijntjens, Gilbert W M; Theunissen, Ruud; van Weert, Angela; Smulders, Martijn W; van den Akker, Nynke; Moerland, Perry D; Verberne, Hein J; Hoebers, Loes P; Henriques, Jose P S; van der Laan, Anja M; Ilhan, Mustafa; Post, Mark; Bekkers, Sebastiaan C A M; Piek, Jan J

    2017-05-08

    An expansive collateral artery network is correlated with improved survival in case of adverse cardiac episodes. We aimed to identify cellular microRNAs (miRNA; miR) important for collateral artery growth. Chronic total occlusion (CTO) patients (n = 26) were dichotomized using pressure-derived collateral flow index (CFI p ) measurements; high collateral capacity (CFI p  > 0.39; n = 14) and low collateral (CFI p  collateral capacity patients. Validation by real-time polymerase chain reaction demonstrated significantly decreased expression of miR339-5p in all stimulated monocyte phenotypes of low collateral capacity patients. MiR339-5p showed significant correlation with CFI p values in stimulated monocytes. Ingenuity pathway analysis of predicted gene targets of miR339-5p and differential gene expression data from high versus low CFI p patients (n = 20), revealed significant association with STAT3 pathway, and also suggested a possible regulatory role for this signaling pathway. These results identify a novel association between miR339-5p and coronary collateral function. Future work examining modulation of miR339-5p and downstream effects on the STAT3 pathway and subsequent collateral vessel growth are warranted.

  19. Detection of human collateral circulation by vasodilation-thallium-201 tomography

    International Nuclear Information System (INIS)

    Nienaber, C.A.; Salge, D.; Spielmann, R.P.; Montz, R.; Bleifeld, W.

    1990-01-01

    Coronary arteriolar vasodilation may provoke redistribution of flow to collateral-dependent jeopardized myocardium. To assess the physiologic significance of collaterals, 80 consecutive post-infarction patients (age 58 +/- 8 years) underwent vasodilation-redistribution thallium-201 tomographic imaging after administration of 0.56 mg of intravenous dipyridamole/kg body weight. Circumferential profile analysis of thallium-201 uptake and redistribution in representative left ventricular tomograms provided quantitative assessment of transient and fixed defects and separation between periinfarctional and distant inducible hypoperfusion. Tomographic perfusion data were correlated to wall motion and collateral circulation between distinct anatomic perfusion territories. Patients were grouped according to presence (59%) or absence (41%) of angiographically visible collateral channels to jeopardized myocardium. In the presence of collaterals, distant reversible defects were larger than in absence of collaterals (p less than 0.05); the extent of combined periinfarctional and distant redistribution was also larger in collateralized patients (p less than 0.025), whereas the size of the persistent perfusion defect was similar in both groups. By prospective analysis the tomographic perfusion pattern of combined periinfarctional and distant redistribution revealed a sensitivity of 85% and a specificity of 78% for the detection of significant collateral circulation in this group of patients. Thus, using the exhausted flow reserve as a diagnostic tool, vasodilation-thallium-201 tomography has the potential to identify and quantitate collateralized myocardium in post-infarction patients and may guide diagnostic and therapeutic decision-making

  20. Coronary collateral circulation: clinical significance and influence on survival in patients with coronary artery occlusion

    DEFF Research Database (Denmark)

    Hansen, J F

    1989-01-01

    In a consecutive series of 96 patients with coronary artery occlusion, 67 had good and 29 had no or poor collateral circulation. Patients with good collaterals had the severest degree of coronary artery disease. Good collaterals are associated with a higher incidence of angina pectoris and normal...... electrocardiogram and with lower incidence of Q-waves, positive exercise tests, heart failure, previous myocardial infarction, and dyskinesia at ventriculography. Survival rates after 10 years were (1) 51.5% with good and 34.5% with poor collaterals (p less than 0.1), (2) 59.4% with angina pectoris and good...... collaterals and 41.2% with angina pectoris and poor collaterals (p less than 0.05), (3) 64.8% without and 24.4% with heart failure and good collaterals (p less than 0.001), and (4) 58.3% without and 16.1% with heart failure and poor collaterals (p less than 0.01). Good collaterals protect the myocardium...

  1. The utility of collateral student drinking reports: Evidence from a biomarker study.

    Science.gov (United States)

    Fendrich, Michael; Fuhrmann, Daniel; Berger, Lisa; Plate, Charles; Lewis, Douglas; Jones, Joseph

    2015-11-01

    Researchers have increasingly used collateral informants to validate the reports provided by primary research subjects. We assessed the utility of collateral informants for college students in a study that incorporates biomarkers to validate student reports of recent drinking behavior. Students from a Midwestern university were randomly selected for a study in which they provided 90-day Timeline Followback data, hair and fingernail specimens for ethylglucuronide (EtG) testing, and information about collateral (friends or peers) informants who were familiar with their drinking behavior. We compared summary measures of recent drinking to collateral informant reports for the subset of 72 students who were selected to participate in the collateral validation process who had complete measures. Kappa, weighted kappa, and McNemar tests were performed to evaluate levels of agreement. We compared levels of use indicated by each informant within the context of EtG findings. We also compared respondent and collateral reports with respect to heavy drinking directly to EtG test results. There was considerable overlap between the reports provided by the student participants and their collateral informants. Within the context of EtG-informed analyses, collaterals rarely provided new information about heavy use beyond that provided by the study subjects. Collateral informants have limited utility in non-clinical studies of heavy drinking in randomly selected college students. Copyright © 2015. Published by Elsevier Ltd.

  2. Non-bronchial collateral supply from the left gastric artery in massive haemoptysis

    International Nuclear Information System (INIS)

    Sellars, N.; Belli, A.M.

    2001-01-01

    Two patients presented with recurrent, massive haemoptysis. Arteriography, including thoracoabdominal aortograms, revealed in both cases large non-bronchial collaterals arising from the left gastric artery. In the first case the non-bronchial collateral supplied the upper left lobe and in the second case it supplied the middle right lobe. Percutaneous embolisation of bronchial and non-bronchial collateral branches has become an accepted procedure in controlling massive or recurrent haemoptysis. Accurate identification of the non-bronchial collateral arterial feeders is essential for successful embolotherapy. (orig.)

  3. Cardiovascular risk factors cause premature rarefaction of the collateral circulation and greater ischemic tissue injury.

    Science.gov (United States)

    Moore, Scott M; Zhang, Hua; Maeda, Nobuyo; Doerschuk, Claire M; Faber, James E

    2015-07-01

    Collaterals lessen tissue injury in occlusive disease. However, aging causes progressive decline in their number and smaller diameters in those that remain (collateral rarefaction), beginning at 16 months of age in mice (i.e., middle age), and worse ischemic injury-effects that are accelerated in even 3-month-old eNOS(-/-) mice. These findings have found indirect support in recent human studies. We sought to determine whether other cardiovascular risk factors (CVRFs) associated with endothelial dysfunction cause collateral rarefaction, investigate possible mechanisms, and test strategies for prevention. Mice with nine different models of CVRFs of 4-12 months of age were assessed for number and diameter of native collaterals in skeletal muscle and brain and for collateral-dependent perfusion and ischemic injury after arterial occlusion. Hypertension caused collateral rarefaction whose severity increased with duration and level of hypertension, accompanied by greater hindlimb ischemia and cerebral infarct volume. Chronic treatment of wild-type mice with L-N (G)-nitro-arginine methylester caused similar rarefaction and worse ischemic injury which were not prevented by lowering arterial pressure with hydralazine. Metabolic syndrome, hypercholesterolemia, diabetes mellitus, and obesity also caused collateral rarefaction. Neither chronic statin treatment nor exercise training lessened hypertension-induced rarefaction. Chronic CVRF presence caused collateral rarefaction and worse ischemic injury, even at relatively young ages. Rarefaction was associated with increased proliferation rate of collateral endothelial cells, effects that may promote accelerated endothelial cell senescence.

  4. Aging causes collateral rarefaction and increased severity of ischemic injury in multiple tissues

    Science.gov (United States)

    Faber, James E.; Zhang, Hua; Lassance-Soares, Roberta M.; Prabhakar, Pranay; Najafi, Amir H.; Burnett, Mary Susan; Epstein, Stephen E.

    2011-01-01

    Objective Aging is a major risk factor for increased ischemic tissue injury. Whether collateral rarefaction and impaired remodeling contribute to this is unknown. We quantified the number and diameter of native collaterals, and their remodeling in 3-, 16-, 24-, and 31-months-old mice. Methods and Results Aging caused an “age-dose-dependent” greater drop in perfusion immediately after femoral artery ligation, followed by a diminished recovery of flow and increase in tissue injury. These effects were associated with a decline in collateral number, diameter and remodeling. Angiogenesis was also impaired. Mechanistically, these changes were not accompanied by reduced recruitment of T-cells or macrophages to remodeling collaterals. However, eNOS signaling was dysfunctional, as indicated by increased protein nitrosylation and less phosphorylated eNOS and VASP in collateral wall cells. The cerebral circulation exhibited a similar age-dose-dependent loss of collateral number and diameter and increased tortuosity, resulting in an increase in collateral resistance and infarct volume (e.g., 6- and 3-fold, respectively, in 24-months-old mice) after artery occlusion. This was not associated with rarefaction of similarly-sized arterioles. Collateral remodeling was also reduced. Conclusions Our findings demonstrate that aging causes rarefaction and insufficiency of the collateral circulation in multiple tissues, resulting in more severe ischemic tissue injury. PMID:21617137

  5. PATTERNS OF FLOWS IN AN INTERMEDIATE PROMINENCE OBSERVED BY HINODE

    International Nuclear Information System (INIS)

    Ahn, Kwangsu; Chae, Jongchul; Cao Wenda; Goode, Philip R.

    2010-01-01

    The investigation of plasma flows in filaments/prominences gives us clues to understanding their magnetic structures. We studied the patterns of flows in an intermediate prominence observed by Hinode/SOT. By examining a time series of Hα images and Ca II H images, we have found horizontal flows in the spine and vertical flows in the barb. Both of these flows have a characteristic speed of 10-20 km s -1 . The horizontal flows displayed counterstreaming. Our detailed investigation revealed that most of the moving fragments in fact reversed direction at the end point of the spine near a footpoint close to the associated active region. These returning flows may be one possible explanation of the well-known counterstreaming flows in prominences. In contrast, we have found vertical flows-downward and upward-in the barb. Most of the horizontal flows in the spine seem to switch into vertical flows when they approach the barb, and vice versa. We propose that the net force resulting from a small deviation from magnetohydrostatic equilibrium, where magnetic fields are predominantly horizontal, may drive these patterns of flow. In the prominence studied here, the supposed magnetohydrostatic configuration is characterized by magnetic field lines sagging with angles of 13 0 and 39 0 in the spine and the barb, respectively.

  6. The Most Prominent Roles of an ESP Teacher

    Science.gov (United States)

    Ghafournia, Narjes; Sabet, Shokoofeh Ahmadian

    2014-01-01

    One prominent feature of many ESP (English for Specific Purposes) courses, which make them rather different from EGP (English for General Purposes) courses, is the presence of adult learners, who are primary workers and secondary learners. As ESP is a highly learner-cantered approach, paying close attention to the multidimensional needs of…

  7. On Lyman-line asymmetries in quiescent prominences

    Czech Academy of Sciences Publication Activity Database

    Gunár, Stanislav; Heinzel, Petr; Anzer, U.; Schmieder, B.

    2008-01-01

    Roč. 490, č. 1 (2008), s. 307-313 ISSN 0004-6361 Grant - others:EU(XE) ESA-PECS project No. 98030 Institutional research plan: CEZ:AV0Z10030501 Keywords : Sun prominences * radiative transfer * line profiles Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.153, year: 2008

  8. Unintended exposure in radiotherapy: Identification of prominent causes

    International Nuclear Information System (INIS)

    Boadu, Mary; Rehani, Madan Mohan

    2009-01-01

    Background and purpose: Unintended exposures in radiotherapy are likely to occur when certain conditions that favour such exposures exist. Based on the frequency of occurrence of various causes of 100 events of unintended exposures in radiotherapy as derived from the analysis of published reports, a checklist for assessing the vulnerability of radiotherapy facilities for potential accidents has been prepared. The list presents items to be considered for safety critical assessments of a radiotherapy department for the improvement of patient safety and the entire radiotherapy processes. Materials and methods: The resources used for this paper consist of 100 unintended radiotherapy exposures and were derived from existing published reports. The analysis was performed by forming two templates: one consisting of 10 initiating events and another of 35 contributing factors. Results: Four most prominent initiating events were identified and together accounted for about 70% of all the unintended exposure events. Ten most prominent contributing factors were also identified and together accounted for about 70% of all the radiotherapy unintended exposure events covered under this study. Conclusion: With this knowledge of high frequency of occurrences, the identified four prominent initiating events and the 10 most prominent contributing factors must be checked and dealt with as a matter of priority when assessing the safety of a radiotherapy facility. A simple checklist for checking the quality assurance programmes of a radiotherapy department for every aspect of the design and delivery of radiation have been provided.

  9. Further Validation of the Coach Identity Prominence Scale

    Science.gov (United States)

    Pope, J. Paige; Hall, Craig R.

    2014-01-01

    This study was designed to examine select psychometric properties of the Coach Identity Prominence Scale (CIPS), including the reliability, factorial validity, convergent validity, discriminant validity, and predictive validity. Coaches (N = 338) who averaged 37 (SD = 12.27) years of age, had a mean of 13 (SD = 9.90) years of coaching experience,…

  10. Whole genome microarray analysis of chicken embryo facial prominences

    Czech Academy of Sciences Publication Activity Database

    Buchtová, Marcela; Kuo, W. P.; Nimmagadda, S.; Benson, S. L.; Geetha-Loganathan, P.; Logan, C.; Au-Yeung, T.; Chiang, E.; Fu, K.; Richman, J. M.

    2010-01-01

    Roč. 239, - (2010), s. 574-591 ISSN 1058-8388 Institutional research plan: CEZ:AV0Z50450515 Keywords : pharyngeal arch * mandibular arch * maxillary prominence Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.864, year: 2010

  11. Prominence modelling: from observed emission measures to temperature profiles

    Czech Academy of Sciences Publication Activity Database

    Anzer, U.; Heinzel, Petr

    2008-01-01

    Roč. 480, č. 2 (2008), s. 537-542 ISSN 0004-6361 Grant - others:EU(XE) ESA-PECS Project No. 98030 Institutional research plan: CEZ:AV0Z10030501 Keywords : Sun * prominences * transition region Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.153, year: 2008

  12. Holdaway's analysis of the nose prominence of an adult Nigerian ...

    African Journals Online (AJOL)

    The nose prominence was assessed using Holdaway's analysis. Twenty radiographs randomly selected, were retraced to assess for errors. Data analysis included descriptive statistics, Student's t‑tests and analysis of variance using the Statistical Package for Social Sciences. Results: The mean value recorded for the nose ...

  13. Eruptive prominences and long-delay geomagnetic storms

    International Nuclear Information System (INIS)

    Wright, C.S.

    1983-01-01

    The relationship between disappearing solar fragments and geomagnetic disturbances was investigated. It is shown that long-delay storms are associated with filaments well removed from the disc centre, and particularly in the case of large filaments and prominences, the proportion of events that produce long-delay storms increases with angular distance from the centre

  14. Cylindrical prominences and the magnetic influence of the photospheric boundary

    International Nuclear Information System (INIS)

    Lerche, I.; Chicago Univ., IL; Low, B.C.

    1980-01-01

    We construct exact, non-linear, solutions for an horizontal, cylindrical, current-carrying, prominence supported against solar gravity by the action of a Lorentz force. The solutions incorporate the photosphere boundary condition, proposed by van Tend and Kuperus (1978), and analyzed by them for line filaments. Our solutions have finite radius for the prominence material and, as well as satisfying the equations of magnetostatic equilibrium, they allow for the continuity of gas pressure, and of the normal and tangential components of magnetic field across the circular prominence boundary. We show that an infinity of solutions is possible and we illustrate the basic behavior by investigation of a special case. We also give a prescription for constructing equilibrium fields for any horizontal prominence with arbitrary cross-section and with an arbitrary external magnetic field. The prescription is ideally suited for numerical codes and we suggest that both the equilibrium of such shapes can easily be accomplished numerically together with their evolutionary history. (orig.)

  15. Lines of MgI Detected in Solar Prominences

    Czech Academy of Sciences Publication Activity Database

    Heinzel, Petr; Kupryakov, Yu. A.; Schwartz, P.

    2016-01-01

    Roč. 40, č. 1 (2016), s. 87-91 ISSN 1845-8319. [Hvar Astrophysical Colloquium /14./. Hvar, 26.09.2016-30.09.2016] Institutional support: RVO:67985815 Keywords : prominences * limb-flare * MgI emession Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  16. Topics and topic prominence in two sign languages

    NARCIS (Netherlands)

    Kimmelman, V.

    2015-01-01

    In this paper we describe topic marking in Russian Sign Language (RSL) and Sign Language of the Netherlands (NGT) and discuss whether these languages should be considered topic prominent. The formal markers of topics in RSL are sentence-initial position, a prosodic break following the topic, and

  17. Multi-Wavelength Eclipse Observations of a Quiescent Prominence

    Czech Academy of Sciences Publication Activity Database

    Jejčič, S.; Heinzel, Petr; Zapiór, M.; Druckmüller, M.; Gunár, Stanislav; Kotrč, Pavel

    2014-01-01

    Roč. 289, č. 7 (2014), s. 2487-2501 ISSN 0038-0938 R&D Projects: GA ČR GAP209/12/0906 Institutional support: RVO:67985815 Keywords : eclipse observations * prominences * quiescent Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.039, year: 2014

  18. Electron densities in quiescent prominences derived from eclipse observations

    Czech Academy of Sciences Publication Activity Database

    Jejčič, S.; Heinzel, Petr

    2009-01-01

    Roč. 254, č. 1 (2009), s. 89-100 ISSN 0038-0938 Grant - others:EU(XE) ESA-PECS project No. 98030 Institutional research plan: CEZ:AV0Z10030501 Keywords : prominences quiescent * eclipse observations * visible spectrum Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.628, year: 2009

  19. Time-resolved assessment of collateral flow using 4D CT angiography in large-vessel occlusion stroke

    International Nuclear Information System (INIS)

    Froelich, Andreas M.J.; Wolff, Sarah Lena; Psychogios, Marios N.; Schramm, Ramona; Knauth, Michael; Schramm, Peter; Klotz, Ernst; Wasser, Katrin

    2014-01-01

    In acute stroke patients with large vessel occlusion, collateral blood flow affects tissue fate and patient outcome. The visibility of collaterals on computed tomography angiography (CTA) strongly depends on the acquisition phase, but the optimal time point for collateral imaging is unknown. We analysed collaterals in a time-resolved fashion using four-dimensional (4D) CTA in 82 endovascularly treated stroke patients, aiming to determine which acquisition phase best depicts collaterals and predicts outcome. Early, peak and late phases as well as temporally fused maximum intensity projections (tMIP) were graded using a semiquantitative regional leptomeningeal collateral score, compared with conventional single-phase CTA and correlated with functional outcome. The total extent of collateral flow was best visualised on tMIP. Collateral scores were significantly lower on early and peak phase as well as on single-phase CTA. Collateral grade was associated with favourable functional outcome and the strength of this relationship increased from earlier to later phases, with collaterals on tMIP showing the strongest correlation with outcome. Temporally fused tMIP images provide the best depiction of collateral flow. Our findings suggest that the total extent of collateral flow, rather than the velocity of collateral filling, best predicts clinical outcome. (orig.)

  20. Tissue-engineered collateral ligament composite allografts for scapholunate ligament reconstruction: an experimental study.

    Science.gov (United States)

    Endress, Ryan; Woon, Colin Y L; Farnebo, Simon J; Behn, Anthony; Bronstein, Joel; Pham, Hung; Yan, Xinrui; Gambhir, Sanjiv S; Chang, James

    2012-08-01

    In patients with chronic scapholunate (SL) dissociation or dynamic instability, ligament repair is often not possible, and surgical reconstruction is indicated. The ideal graft ligament would recreate both anatomical and biomechanical properties of the dorsal scapholunate ligament (dorsal SLIL). The finger proximal interphalangeal joint (PIP joint) collateral ligament could possibly be a substitute ligament. We harvested human PIP joint collateral ligaments and SL ligaments from 15 cadaveric limbs. We recorded ligament length, width, and thickness, and measured the biomechanical properties (ultimate load, stiffness, and displacement to failure) of native dorsal SLIL, untreated collateral ligaments, decellularized collateral ligaments, and SL repairs with bone-collateral ligament-bone composite collateral ligament grafts. As proof of concept, we then reseeded decellularized bone-collateral ligament-bone composite grafts with green fluorescent protein-labeled adipo-derived mesenchymal stem cells and evaluated them histologically. There was no difference in ultimate load, stiffness, and displacement to failure among native dorsal SLIL, untreated and decellularized collateral ligaments, and SL repairs with tissue-engineered collateral ligament grafts. With pair-matched untreated and decellularized scaffolds, there was no difference in ultimate load or stiffness. However, decellularized ligaments revealed lower displacement to failure compared with untreated ligaments. There was no difference in displacement between decellularized ligaments and native dorsal SLIL. We successfully decellularized grafts with recently described techniques, and they could be similarly reseeded. Proximal interphalangeal joint collateral ligament-based bone-collateral ligament-bone composite allografts had biomechanical properties similar to those of native dorsal SLIL. Decellularization did not adversely affect material properties. These tissue-engineered grafts may offer surgeons another

  1. Nox2 and p47phox modulate compensatory growth of primary collateral arteries

    Science.gov (United States)

    DiStasi, Matthew R.; Unthank, Joseph L.

    2014-01-01

    The role of NADPH oxidase (Nox) in both the promotion and impairment of compensatory collateral growth remains controversial because the specific Nox and reactive oxygen species involved are unclear. The aim of this study was to identify the primary Nox and reactive oxygen species associated with early stage compensatory collateral growth in young, healthy animals. Ligation of the feed arteries that form primary collateral pathways in rat mesentery and mouse hindlimb was used to assess the role of Nox during collateral growth. Changes in mesenteric collateral artery Nox mRNA expression determined by real-time PCR at 1, 3, and 7 days relative to same-animal control arteries suggested a role for Nox subunits Nox2 and p47phox. Administration of apocynin or Nox2ds-tat suppressed collateral growth in both rat and mouse models, suggesting the Nox2/p47phox interaction was involved. Functional significance of p47phox expression was assessed by evaluation of collateral growth in rats administered p47phox small interfering RNA and in p47phox−/− mice. Diameter measurements of collateral mesenteric and gracilis arteries at 7 and 14 days, respectively, indicated no significant collateral growth compared with control rats or C57BL/6 mice. Chronic polyethylene glycol-conjugated catalase administration significantly suppressed collateral development in rats and mice, implying a requirement for H2O2. Taken together, these results suggest that Nox2, modulated at least in part by p47phox, mediates early stage compensatory collateral development via a process dependent upon peroxide generation. These results have important implications for the use of antioxidants and the development of therapies for peripheral arterial disease. PMID:24633549

  2. Collateral hepatic circulation with the portal hypertension syndrome in children

    International Nuclear Information System (INIS)

    Filippkin, M.A.; Kondakov, V.T.; Artamonov, Yu.A.

    1990-01-01

    The results of complex examination carried out in 80 children of different age with the extrahepatic form of portal hypertension and liver fibrosis are presented. Correspondence between clinical and roentgenoangiograph patterns of disease is detected. Dependence of the degree of varicose transformation of submucous veins of the esophagus and stomach on the value and the character of portal blood disposal is established. The risk group is detected. Clinico-X-ray comparisons carried out testify about advisability of the account of individual features of collateral hepatic circulation of the liver when developing medical treatment

  3. Computed tomographic manifestations of abdominal and pelvic venous collaterals

    International Nuclear Information System (INIS)

    Pagani, J.J.; Thomas, J.L.; Bernardino, M.E.

    1982-01-01

    Obstruction of blood flow through the inferior vena cava and portal vein may produce venous collaterals. These include the paravertebral venous system and its communications with the ascending lumbar veins and azygous/hemiazygous system; gonadal, periureteric, and other retroperitoneal veins; abdominal wall veins; hemorrhoidal venous plexus; and the portal venous system. The anatomic location of these vessels is discussed. Computed tomography demonstrates them as round or tubular structures that are isodens when compared with other venous structures following contrast material administration. Techniques of examination and methods of differentiation of these vascular structures from other abnormalities, especially lymphadenopathy, are discussed

  4. Interferon-beta signaling is enhanced in patients with insufficient coronary collateral artery development and inhibits arteriogenesis in mice

    NARCIS (Netherlands)

    Schirmer, Stephan H.; Fledderus, Joost O.; Moerland, Perry D.; Hoefer, Imo E.; Henriques, Jose P. S.; van der Schaaf, Rene J.; Vis, Marije M.; Horrevoets, Anton J. G.; Piek, Jan J.; van Royen, Niels; Baan, J.

    2008-01-01

    Stimulation of collateral artery growth in patients has been hitherto unsuccessful, despite promising experimental approaches. Circulating monocytes are involved in the growth of collateral arteries, a process also referred to as arteriogenesis. Patients show a large heterogeneity in their natural

  5. Innate collateral segments are predominantly present in the subendocardium without preferential connectivity within the left ventricular wall

    NARCIS (Netherlands)

    van Horssen, Pepijn; Siebes, Maria; Spaan, Jos A. E.; Hoefer, Imo E.; van den Wijngaard, Jeroen P. H. M.

    2014-01-01

    Functional collateral vessels often stem from outward remodelling of pre-existing connections between perfusion territories. Knowledge of the distribution and morphology of innate collateral connections may help in identifying myocardial areas with protection against risk for ischaemia. The coronary

  6. Excimer laser coronary atherectomy in septal collaterals during retrograde recanalization of a chronic total occlusion

    Directory of Open Access Journals (Sweden)

    Bernward Lauer

    2011-09-01

    Full Text Available Management of chronic total occlusions has been refined through the development of a retrograde approach via collateral pathways. We describe the use of Excimer Laser Coronary Atherectomy in the septal collaterals. This appraoch was not yet described in the literature.

  7. Noninvasive assessment of coronary collaterals in man by PET perfusion imaging

    International Nuclear Information System (INIS)

    Demer, L.L.; Gould, K.L.; Goldstein, R.A.; Kirkeeide, R.L.

    1990-01-01

    At present, coronary collateralization cannot be identified or assessed noninvasively in patients. In animal studies, coronary collaterals are associated with coronary steal, defined as a regional fall in perfusion during coronary arteriolar vasodilation. To determine the effect of coronary arteriolar vasodilation on collateral bed perfusion in man, myocardial perfusion imaging was performed before and after pharmacologic coronary vasodilation in patients with coronary artery disease (CAD). Regional myocardial activity of 82 Rb or 13 N ammonia was measured by positron emission tomography (PET) at rest and with intravenous dipyridamole/handgrip stress in 28 patients with angiographic collaterals and in 25 control patients with similar CAD severity by quantitative arteriography. Regional myocardial activity decreased after dipyridamole, indicating coronary steal, in 25 of 28 patients with angiographic collaterals and in only 4 of 25 control patients without angiographic collaterals. These findings suggest that developed collaterals are associated with myocardial steal in patients with CAD, allowing potential use of PET for non-invasive identification of coronary collateralization

  8. Characterizing the angiogenic activity of patients with single ventricle physiology and aortopulmonary collateral vessels.

    Science.gov (United States)

    Sandeep, Nefthi; Uchida, Yutaka; Ratnayaka, Kanishka; McCarter, Robert; Hanumanthaiah, Sridhar; Bangoura, Aminata; Zhao, Zhen; Oliver-Danna, Jacqueline; Leatherbury, Linda; Kanter, Joshua; Mukouyama, Yoh-Suke

    2016-04-01

    Patients with single ventricle congenital heart disease often form aortopulmonary collateral vessels via an unclear mechanism. To gain insights into the pathogenesis of aortopulmonary collateral vessels, we correlated angiogenic factor levels with in vitro activity and angiographic aortopulmonary collateral assessment and examined whether patients with single ventricle physiology have increased angiogenic factors that can stimulate endothelial cell sprouting in vitro. In patients with single ventricle physiology (n = 27) and biventricular acyanotic control patients (n = 21), hypoxia-inducible angiogenic factor levels were measured in femoral venous and arterial plasma at cardiac catheterization. To assess plasma angiogenic activity, we used a 3-dimensional in vitro cell sprouting assay that recapitulates angiogenic sprouting. Aortopulmonary collateral angiograms were graded using a 4-point scale. Compared with controls, patients with single ventricle physiology had increased vascular endothelial growth factor (artery: 58.7 ± 1.2 pg/mL vs 35.3 ± 1.1 pg/mL, P collateral severity. We are the first to correlate plasma angiogenic factor levels with angiography and in vitro angiogenic activity in patients with single ventricle disease with aortopulmonary collaterals. Patients with single ventricle disease have increased stromal-derived factor 1-alpha and soluble fms-like tyrosine kinase-1, and their roles in aortopulmonary collateral formation require further investigation. Plasma factors and angiogenic activity correlate poorly with aortopulmonary collateral severity in patients with single ventricles, suggesting complex mechanisms of angiogenesis. Published by Elsevier Inc.

  9. Influence of risk area size and location on native collateral resistance and ischemic zone perfusion

    International Nuclear Information System (INIS)

    Gumm, D.C.; Cooper, S.M.; Thompson, S.B.; Marcus, M.L.; Harrison, D.C.

    1988-01-01

    To examine the effect of risk area size on collateral resistance and ichemic region perfusion, the authors produced different sized risk areas by occluding either the left anterior descending (LAD) or the circumflex (Cx) coronary artery at different sites. The most proximal occlusion of the LAD and Cx produced risk areas of 43 ± 5 and 36 ± 2% of left ventricular (LV) mass, respectively, whereas distal LAD and Cx occlusions produced risk areas of 13 ± 2 and 17 ± 2% of LV weight, respectively. Although total collateral flow was highest to the largest risk areas, collateral flow per 100 g of ischemic myocardium was 80% higher to the small LAD risk area compared with the large LAD risk area and 43% higher to the small Cx risk area compared with the large Cx risk area. Collateral resistance, calculated from the transcollateral pressure and perfusion per 100 g of myocardium was significantly lower in the small risk areas than in the large ones. They examined the effect of risk area location on collateral perfusion and resistance. These experiments show that collateral resistance is influenced both by ischemic region size and location. Small risk areas receive more collateral flow per mass of tissue than large risk areas, and apical risk areas receive greater quantities of collateral flow than those located at the base. These data may explain why small risk areas often do not develop infarction after coronary occlusion

  10. Selective cyclooxygenase-1 inhibition improves collateral vascular reactivity in biliary cirrhotic rats

    Directory of Open Access Journals (Sweden)

    Ching-Chih Chang

    2013-10-01

    Conclusion: There was no significant hemodynamic change and renal toxicity after acute administration of COX inhibitor in the FBDL-induced cirrhotic rats. Preincubation of selective COX-1, but not COX-2, inhibitor could enhance collateral vascular response to AVP, indicating that COX-1 plays a major role in the collateral vascular reactivity.

  11. The Power of Collateral : How Problems in Securing Transections Limit Private Credit from Movable Property

    OpenAIRE

    Fleisig, Heywood

    1995-01-01

    In many developing countries, faulty laws and regulations make it hard to use livestock, machines, equipment, standing crops, and other movable property as collateral. The resulting constraints on access to credit hurt economies. In Bolivia, for example, a faulty legal and regulatory framework for the use of movable property as collateral has led to a loss in GDP estimated at between 5 and...

  12. Local Cytokine Concentrations and Oxygen Pressure Are Related to Maturation of the Collateral Circulation in Humans

    NARCIS (Netherlands)

    Schirmer, Stephan H.; van Royen, Niels; Moerland, Perry D.; Fledderus, Joost O.; Henriques, José P.; van der Schaaf, René J.; Vis, Marije M.; Baan, Jan; Koch, Karel T.; Horrevoets, Anton J. G.; Hoefer, Imo E.; Piek, Jan J.

    2009-01-01

    Objectives Our aim was to determine cytokine and oxygen gradients over the collateral circulation in humans. Background The molecular background of the maturation of the collateral circulation in response to coronary narrowing is poorly understood in humans, partly because of difficulties in

  13. Functional significance of coronary collateral circulation during dynamic exercise evaluated by thallium-201 myocardial scintigraphy

    International Nuclear Information System (INIS)

    Wainwright, R.J.; Maisey, M.N.; Edwards, A.C.; Sowton, E.

    1980-01-01

    Sixty-five patients with angiographically documented coronary artery disease were investigated by thallium-201 ( 201 Tl) scintigraphy to determine the role of the collateral circulation during dynamic exercise. Fifty-three patients had complete proximal occlusion of at least one major coronary artery. One patient had total occlusion of all three major coronary arteries. Sixty-four collateral channels were identified, graded, and compared with corresponding regions of the myocardial scintigram. Tracer uptake was also graded and classified as various degrees of protection from ischaemia. A significant correlation between good collaterals with complete protection and poor or absent collaterals with no protection was noted. Seventeen patients (20 occluded vessels) had total coronary occlusion without myocardial infarction. Collaterals conferred protection in 9/15 occlusions whereas no protection was seen in five occlusions without collaterals. There was no difference in the protective role of homocoronary and heterocoronary collateral vessels. Hypertrophy of the first septal left anterior descending perforator conferred significant protection from ischaemia in contrast to bridging collaterals and ghosting. During exercise the right coronary bed is preferentially protected from ischaemia, in contrast to the left anterior descending territory. This probably reflects the direction of a transmural flow gradient between left and right ventricles during exercise. (author)

  14. 13 CFR 123.11 - Does SBA require collateral for any of its disaster loans?

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Does SBA require collateral for any of its disaster loans? 123.11 Section 123.11 Business Credit and Assistance SMALL BUSINESS...? Generally, SBA will not require that you pledge collateral to secure a disaster home loan or a physical...

  15. SmPL: A Domain-Specific Language for Specifying Collateral Evolutions in Linux Device Drivers

    DEFF Research Database (Denmark)

    Padioleau, Yoann; Lawall, Julia Laetitia; Muller, Gilles

    2007-01-01

    identifying the affected files and modifying all of the code fragments in these files that in some way depend on the changed interface. We have studied the collateral evolution problem in the context of Linux device drivers. Currently, collateral evolutions in Linux are mostly done manually using a text...

  16. Computed tomographic characteristics of collateral venous pathways in dogs with caudal vena cava obstruction.

    Science.gov (United States)

    Specchi, Swan; d'Anjou, Marc-André; Carmel, Eric Norman; Bertolini, Giovanna

    2014-01-01

    Collateral venous pathways develop in dogs with obstruction or increased blood flow resistance at any level of the caudal vena cava in order to maintain venous drainage to the right atrium. The purpose of this retrospective study was to describe the sites, causes of obstruction, and configurations of venous collateral pathways for a group of dogs with caudal vena cava obstruction. Computed tomography databases from two veterinary hospitals were searched for dogs with a diagnosis of caudal vena cava obstruction and multidetector row computed tomographic angiographic (CTA) scans that included the entire caudal vena cava. Images for each included dog were retrieved and collateral venous pathways were characterized using image postprocessing and a classification system previously reported for humans. A total of nine dogs met inclusion criteria and four major collateral venous pathways were identified: deep (n = 2), portal (n = 2), intermediate (n = 7), and superficial (n = 5). More than one collateral venous pathway was present in 5 dogs. An alternative pathway consisting of renal subcapsular collateral veins, arising mainly from the caudal pole of both kidneys, was found in three dogs. In conclusion, findings indicated that collateral venous pathway patterns similar to those described in humans are also present in dogs with caudal vena cava obstruction. These collateral pathways need to be distinguished from other vascular anomalies in dogs. Postprocessing of multidetector-row CTA images allowed delineation of the course of these complicated venous pathways and may be a helpful adjunct for treatment planning in future cases. © 2014 American College of Veterinary Radiology.

  17. 25 CFR 166.223 - Can I use a permit as collateral for a loan?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Can I use a permit as collateral for a loan? 166.223... PERMITS Permit Requirements Permit (leasehold) Mortgage § 166.223 Can I use a permit as collateral for a loan? We may approve a permit containing a provision that authorizes the permittee to encumber the...

  18. Collateralization, Bank Loan Rates and Monitoring : Evidence from a Natural Experiment

    NARCIS (Netherlands)

    Cerqueiro, G.M.; Ongena, S.; Roszbach, K.

    2011-01-01

    Collateral is one of the most important features of a debt contract. A substantial theoretical literature motivates the use of collateral as a means to alleviate ex-ante and ex-post information asymmetries between borrowers and lenders and the incidence of credit rationing. Through its seniority

  19. Abnormal monocyte recruitment and collateral artery formation in monocyte chemoattractant protein-1 deficient mice

    NARCIS (Netherlands)

    Voskuil, Michiel; Hoefer, Imo E.; van Royen, Niels; Hua, Jing; de Graaf, Stijn; Bode, Christoph; Buschmann, Ivo R.; Piek, Jan J.

    2004-01-01

    Monocyte chemoattractant protein 1 (MCP-1) has been shown to be effective for the stimulation of collateral artery formation in small and large animal models. The availability of a genetic knockout mouse enables evaluation of the importance of the role of MCP-1 in the natural course of collateral

  20. Tests of Ex Ante Versus Ex Post Theories of Collateral Using Private and Public Information

    NARCIS (Netherlands)

    Berger, A.N.; Frame, W.S.; Ioannidou, V.

    2010-01-01

    Collateral is a widely used, but not well understood, debt contracting feature. Two broad strands of theoretical literature explain collateral as arising from the existence of either ex ante private information or ex post incentive problems between borrowers and lenders. However, the extant

  1. Tests of ex ante ex post theories of collateral using private and public information

    NARCIS (Netherlands)

    Berger, A.N.; Frame, W.S.; Ioannidou, V.

    2011-01-01

    Collateral is a widely used, but not well understood, debt contracting feature. Two broad strands of theoretical literature explain collateral as arising from the existence of either ex ante private information or ex post incentive problems between borrowers and lenders. However, the extant

  2. Absent collateral function of the circle of Willis as risk factor for ischemic stroke

    NARCIS (Netherlands)

    Hoksbergen, A. W. J.; Legemate, D. A.; Csiba, L.; Csáti, G.; Síró, P.; Fülesdi, B.

    2003-01-01

    Background. Autopsy studies show a higher prevalence of circle of Willis anomalies in brains with signs of ischemic infarction. Our goal was to examine the collateral function of the circle of Willis in ischemic stroke patients and to assess in a case-control study if a collateral deficient circle

  3. Inflammatory processes during arteriogenesis : the contribution of the innate immune system to collateral artery growth

    NARCIS (Netherlands)

    de Groot, D.

    2011-01-01

    The central theme of the work presented in the thesis is restoration of tissue perfusion by collateral artery growth. During collateral artery growth, or arteriogenesis, unused pre-existing vascular anastomoses remodel into functional arteries. These arteries are able to take over the perfusion of

  4. Stimulation of collateral artery growth: travelling further down the road to clinical application

    NARCIS (Netherlands)

    Schirmer, S. H.; van Nooijen, F. C.; Piek, J. J.; van Royen, N.

    2009-01-01

    Collateral artery growth is a potent natural defence mechanism to prevent death and myocardial infarction in occlusive artery disease. Given the high prevalence of arterial obstructive disease, a therapeutic compound stimulating collateral vessel growth could have a major impact on morbidity and

  5. De-novo collateral formation following acute myocardial infarction: Dependence on CCR2⁺ bone marrow cells.

    Science.gov (United States)

    Zhang, Hua; Faber, James E

    2015-10-01

    Wide variation exists in the extent (number and diameter) of native pre-existing collaterals in tissues of different strains of mice, with supportive indirect evidence recently appearing for humans. This variation is a major determinant of the wide variation in severity of tissue injury in occlusive vascular disease. Whether such genetic-dependent variation also exists in the heart is unknown because no model exists for study of mouse coronary collaterals. Also owing to methodological limitations, it is not known if ischemia can induce new coronary collaterals to form ("neo-collaterals") versus remodeling of pre-existing ones. The present study sought to develop a model to study coronary collaterals in mice, determine whether neo-collateral formation occurs, and investigate the responsible mechanisms. Four strains with known rank-ordered differences in collateral extent in brain and skeletal muscle were studied: C57BLKS>C57BL/6>A/J>BALB/c. Unexpectedly, these and 5 additional strains lacked native coronary collaterals. However after ligation, neo-collaterals formed rapidly within 1-to-2 days, reaching their maximum extent in ≤7 days. Rank-order for neo-collateral formation differed from the above: C57BL/6>BALB/c>C57BLKS>A/J. Collateral network conductance, infarct volume(-1), and contractile function followed this same rank-order. Neo-collateral formation and collateral conductance were reduced and infarct volume increased in MCP1(-/-) and CCR2(-/-) mice. Bone-marrow transplant rescued collateral formation in CCR2(-/-) mice. Involvement of fractalkine➔CX3CR1 signaling and endothelial cell proliferation were also identified. This study introduces a model for investigating the coronary collateral circulation in mice, demonstrates that neo-collaterals form rapidly after coronary occlusion, and finds that MCP➔CCR2-mediated recruitment of myeloid cells is required for this process. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Persistence of recruitable coronary collaterals in the absence of coronary vasospasm in a patient with variant angina

    International Nuclear Information System (INIS)

    Yamashita, Kazuhito; Takeuchi, Masaaki; Nakashima, Yasuhide

    1998-01-01

    Recruitable coronary collaterals may appear when spasm suddenly occludes the coronary artery. We report a patient with variant angina who had visible collateral vessels on a control coronary angiogram, despite the presence of normally appearing coronary arteries. These collaterals disappeared after intracoronary administration of nitroglycerin. These findings suggest that recruitable collateral vessels can remain patent long after spontaneous attacks of angina have resolved, and become visible when there is a pressure difference between two small coronary arteries.

  7. Persistence of Recruitable Coronary Collaterals in the Absence of Coronary Vasospasm in a Patient with Variant Angina

    International Nuclear Information System (INIS)

    Yamashita, Kazuhito; Takeuchi, Masaaki; Nakashima, Yasuhide

    1998-01-01

    Recruitable coronary collaterals may appear when spasm suddenly occludes the coronary artery. We report a patient with variant angina who had visible collateral vessels on a control coronary angiogram, despite the presence of normally appearing coronary arteries. These collaterals disappeared after intracoronary administration of nitroglycerin. These findings suggest that recruitable collateral vessels can remain patent long after spontaneous attacks of angina have resolved, and become visible when there is a pressure difference between two small coronary arteries

  8. Head turning as a prominent motor symptom in status epilepticus.

    Science.gov (United States)

    Bauer, Gerhard; Broessner, Gregor; Unterberger, Iris; Walser, Gerald; Pfausler, Bettina; Trinka, Eugen

    2008-06-01

    Head and eye turning is frequently observed during seizures. Versions with tonic and/or clonic symptoms can be differentiated from smooth head deviations. Head turning as a prominent symptom of status epilepticus has not previously been reported. We present eight case reports, (7 women/1 man, mean age 41 years, median 41.5, range 10 to 74), of status epilepticus (SE), with head turning as a prominent motor symptom. Six were accompanied by continuous frontal, occipital and temporal ictal epileptiform discharges. Furthermore, two patients had absence status with rhythmic and clonic head versions. While the localizing significance of head turnings in SE is low, in our cases, the direction was away from the discharging hemisphere in all cases of focal SE regardless of whether the turning was classified as version (three cases) or deviation (three cases). In this small series of SE, the classical observation of a patient looking away from the discharging hemisphere is still valid.

  9. Non-LTE hydrogen-line formation in moving prominences

    Science.gov (United States)

    Heinzel, P.; Rompolt, B.

    1986-01-01

    The behavior of hydrogen-line brightness variations, depending on the prominence-velocity changes were investigated. By solving the NON-Local thermodynamic equilibrium (LTE) problem for hydrogen researchers determine quantitatively the effect of Doppler brightening and/or Doppler dimming (DBE, DDE) in the lines of Lyman and Balmer series. It is demonstrated that in low-density prominence plasmas, DBE in H alpha and H beta lines can reach a factor of three for velocities around 160 km/sec, while the L alpha line exhibits typical DDE. L beta brightness variations follow from a combined DBE in the H alpha and DDE in L alpha and L beta itself, providing that all relevant multilevel interlocking processes are taken into account.

  10. Collateral methotrexate resistance in cisplatin-selected murine leukemia cells

    Directory of Open Access Journals (Sweden)

    Bhushan A.

    1999-01-01

    Full Text Available Resistance to anticancer drugs is a major cause of failure of many therapeutic protocols. A variety of mechanisms have been proposed to explain this phenomenon. The exact mechanism depends upon the drug of interest as well as the tumor type treated. While studying a cell line selected for its resistance to cisplatin we noted that the cells expressed a >25,000-fold collateral resistance to methotrexate. Given the magnitude of this resistance we elected to investigate this intriguing collateral resistance. From a series of investigations we have identified an alteration in a membrane protein of the resistant cell as compared to the sensitive cells that could be the primary mechanism of resistance. Our studies reviewed here indicate decreased tyrosine phosphorylation of a protein (molecular mass = 66 in the resistant cells, which results in little or no transfer of methotrexate from the medium into the cell. Since this is a relatively novel function for tyrosine phosphorylation, this information may provide insight into possible pharmacological approaches to modify therapeutic regimens by analyzing the status of this protein in tumor samples for a better survival of the cancer patients.

  11. STRUCTURE OF PROMINENCE LEGS: PLASMA AND MAGNETIC FIELD

    Energy Technology Data Exchange (ETDEWEB)

    Levens, P. J.; Labrosse, N. [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ (United Kingdom); Schmieder, B. [Observatoire de Paris, Meudon, F-92195 (France); Ariste, A. López, E-mail: p.levens.1@research.gla.ac.uk [Institut de Recherche en Astrophysique et Planétologie, Toulouse (France)

    2016-02-10

    We investigate the properties of a “solar tornado” observed on 2014 July 15, and aim to link the behavior of the plasma to the internal magnetic field structure of the associated prominence. We made multi-wavelength observations with high spatial resolution and high cadence using SDO/AIA, the Interface Region Imaging Spectrograph (IRIS) spectrograph, and the Hinode/Solar Optical Telescope (SOT) instrument. Along with spectropolarimetry provided by the Télescope Héliographique pour l’Etude du Magnétisme et des Instabilités Solaires telescope we have coverage of both optically thick emission lines and magnetic field information. AIA reveals that the two legs of the prominence are strongly absorbing structures which look like they are rotating, or oscillating in the plane of the sky. The two prominence legs, which are both very bright in Ca ii (SOT), are not visible in the IRIS Mg ii slit-jaw images. This is explained by the large optical thickness of the structures in Mg ii, which leads to reversed profiles, and hence to lower integrated intensities at these locations than in the surroundings. Using lines formed at temperatures lower than 1 MK, we measure relatively low Doppler shifts on the order of ±10 km s{sup −1} in the tornado-like structure. Between the two legs we see loops in Mg ii, with material flowing from one leg to the other, as well as counterstreaming. It is difficult to interpret our data as showing two rotating, vertical structures that are unrelated to the loops. This kind of “tornado” scenario does not fit with our observations. The magnetic field in the two legs of the prominence is found to be preferentially horizontal.

  12. Beat gestures and prosodic prominence: impact on learning

    OpenAIRE

    Kushch, Olga

    2018-01-01

    Previous research has shown that gestures are beneficial for language learning. This doctoral thesis centers on the effects of beat gestures– i.e., hand and arm gestures that are typically associated with prosodically prominent positions in speech - on such processes. Little is known about how the two central properties of beat gestures, namely how they mark both information focus and rhythmic positions in speech, can be beneficial for learning either a first or a second language. The main go...

  13. Observations of apparent superslow wave propagation in solar prominences

    Science.gov (United States)

    Raes, J. O.; Van Doorsselaere, T.; Baes, M.; Wright, A. N.

    2017-06-01

    Context. Phase mixing of standing continuum Alfvén waves and/or continuum slow waves in atmospheric magnetic structures such as coronal arcades can create the apparent effect of a wave propagating across the magnetic field. Aims: We observe a prominence with SDO/AIA on 2015 March 15 and find the presence of oscillatory motion. We aim to demonstrate that interpreting this motion as a magneto hydrodynamic (MHD) wave is faulty. We also connect the decrease of the apparent velocity over time with the phase mixing process, which depends on the curvature of the magnetic field lines. Methods: By measuring the displacement of the prominence at different heights to calculate the apparent velocity, we show that the propagation slows down over time, in accordance with the theoretical work of Kaneko et al. We also show that this propagation speed drops below what is to be expected for even slow MHD waves for those circumstances. We use a modified Kippenhahn-Schlüter prominence model to calculate the curvature of the magnetic field and fit our observations accordingly. Results: Measuring three of the apparent waves, we get apparent velocities of 14, 8, and 4 km s-1. Fitting a simple model for the magnetic field configuration, we obtain that the filament is located 103 Mm below the magnetic centre. We also obtain that the scale of the magnetic field strength in the vertical direction plays no role in the concept of apparent superslow waves and that the moment of excitation of the waves happened roughly one oscillation period before the end of the eruption that excited the oscillation. Conclusions: Some of the observed phase velocities are lower than expected for slow modes for the circumstances, showing that they rather fit with the concept of apparent superslow propagation. A fit with our magnetic field model allows for inferring the magnetic geometry of the prominence. The movie attached to Fig. 1 is available at http://www.aanda.org

  14. Relationship between haemodynamic impairment and collateral blood flow in carotid artery disease

    DEFF Research Database (Denmark)

    Hartkamp, Nolan S; Petersen, Esben T; Chappell, Michael A

    2018-01-01

    Collateral blood flow plays a pivotal role in steno-occlusive internal carotid artery (ICA) disease to prevent irreversible ischaemic damage. Our aim was to investigate the effect of carotid artery disease upon cerebral perfusion and cerebrovascular reactivity and whether haemodynamic impairment...... is influenced at brain tissue level by the existence of primary and/or secondary collateral. Eighty-eight patients with steno-occlusive ICA disease and 29 healthy controls underwent MR examination. The presence of collaterals was determined with time-of-flight, two-dimensional phase contrast MRA and territorial....... In conclusion, both CBF and cerebrovascular reactivity were found to be reduced in symptomatic patients with steno-occlusive ICA disease. The presence of collateral flow is associated with further haemodynamic impairment. Recruitment of secondary collaterals is associated with severe haemodynamic impairment....

  15. Decreased perfusion in myocardial region of normal donor artery secondary to collateral development

    International Nuclear Information System (INIS)

    Koga, Y.; Takahashi, M.; Kojima, A.; Takaki, Y.; Tomiguchi, S.; Hirota, Y.; Kugiyama, K.; Yasue, H.; Hayasaki, K.; Kumamoto Saiseikai Hospital

    1992-01-01

    Thirty-one patients suffering from single vessel exertional angina with collaterals (Group A) were evaluated by stress 201 Tl myocardial emission CT (Tl-SPECT) with 16 controls of severely stenotic single vessel exertional angina without collaterals (Group B). Group A included 21 patients (68%) who showed an extensive perfusion defect in double artery myocardial regions, including the normal donor artery myocardial region (DMR). However, there were no such cases in Group B, giving a significant difference between these 2 groups (p < 0.001). Four patients in Group A, having a perfusion defect both in DMR and in the collateral dependent myocardial region (CMR) underwent a successful percutaneous transluminal coronary angioplasty (PTCA) with disappearance of collaterals. Tl-SPECT findings after PTCA showed no perfusion defect either in CMR or in DMR. This has been explained on the basis that the coronary collaterals stole blood and produced perfusion defect in DMR. (orig.)

  16. Kinematics of partial and total ruptures of the medial collateral ligament of the elbow

    DEFF Research Database (Denmark)

    Eygendaal, D; Olsen, Bo Sanderhoff; Jensen, Steen Lund

    2000-01-01

    In this study the kinematics of partial and total ruptures of the medial collateral ligament of the elbow are investigated. After selective transection of the medial collateral ligament of 8 osteoligamentous intact elbow preparations was performed, 3-dimensional measurements of angular displacement......, increase in medial joint opening, and translation of the radial head were examined during application of relevant stress. Increase in joint opening was significant only after complete transection of the anterior part of the medial collateral ligament was performed. The joint opening was detected during...... valgus and internal rotatory stress only. After partial transection of the anterior bundle of the medial collateral ligament was performed, there was an elbow laxity to valgus and internal rotatory force, which became significant after transection of 100% of the anterior bundle of the medial collateral...

  17. Collateral Consequences and Effectiveness of Sex Offender Registration and Notification: Law Enforcement Perspectives.

    Science.gov (United States)

    Cubellis, Michelle A; Walfield, Scott M; Harris, Andrew J

    2018-03-01

    A growing body of research has examined the collateral effects of sex offender registration and notification (SORN), particularly those related to offenders' social and economic reintegration into society. Although studies have examined public, offender, treatment provider, and other criminal justice perspectives on SORN's collateral impacts, few have elicited the views of law enforcement (LE) professionals who have contact with registered offenders. This study presents results from a mixed method study examining LE perspectives on collateral consequences and effectiveness of SORN. Results indicate that, although overall LE concern regarding collateral impacts is limited, those who are most engaged in SORN-related duties are significantly more likely to indicate such concern, and also more likely to believe that SORN was an effective public safety tool. Importantly, respondents in states with larger registries expressed greater concern over collateral consequences, and less belief in SORN's public safety efficacy. Implications for policy and practice are discussed.

  18. The significance of collateral vessels, as seen on chest CT, in predicting SVC obstruction

    International Nuclear Information System (INIS)

    Yeouk, Young Soo; Kim, Sung Jin; Bae, Il Hun; Kim, Jae Youn; Hwang, Seung Min; Han, Gi Seok; Park, Kil Sun; Kim, Dae Young

    1998-01-01

    To evaluate the significance of collateral veins, as seen on chest CT, in the diagnosis of superior vena cava obstruction. We retrospectively the records of 81 patients in whom collateral veins were seen on chest CT. On spiral CT(n=49), contrast material was infused via power injector, and on conventional CT(n=32), 50 ml bolus infusion was followed by 50 ml drip infusion. Obstruction of the SVC was evaluated on chest CT; if, however, evaluation of the SVC of its major tributaries was difficult, as in five cases, the patient underwent SVC phlebography. Collateral vessels were assigned to one of ten categories. On conventional CT, the jugular venous arch in the only collateral vessel to predict SVC obstruction; on spiral CT, however, collateral vessels are not helpful in the diagnosis of SVC obstruction, but are a nonspecific finding. (author). 12 refs., 2 tab., 2 figs

  19. Breast varices: imaging findings of an unusual presentation of collateral pathways in superior vena caval syndrome

    International Nuclear Information System (INIS)

    Oezdemir, Ayseguel; Ilgit, Erhan T.; Konus, Oeznur L.; Cetin, Meltem; Oezsunar, Yelda

    2000-01-01

    Imaging findings are presented of an unusual pathway of collateral circulation consisting of bilateral and diffuse dilated breast veins from a patient with long standing superior vena caval syndrome. The main importance of this case is the extent of the collateral development through the breast veins, serving as the major pathway of collateral circulation. Identification of this unusual collateral development, which resembles breast varices, was performed with contrast-enhanced chest CT scans, digital subtraction venography, color Doppler ultrasonography, and mammographic studies. Collateral development was secondary to a long segment idiopathic venous occlusion involving bilateral subclavian and brachiocephalic veins as well as vena cava superior. We conclude that dilated breast veins when detected on any imaging modality should raise the suspicion of central venous obstruction

  20. Significance of collateral circulation on peri-infarct zone: assessment with stress thallium-201 scintigraphy

    International Nuclear Information System (INIS)

    Imamura, T.; Araki, H.; Fukuyama, T.; Maruoka, Y.; Ootsubo, H.; Nakamura, M.; Koiwaya, Y.; Tanaka, K.

    1986-01-01

    To evaluate the significance of collateral circulation on peri-infarct zone, stress myocardial scintigraphy and contrast left ventriculography (LVG) were performed in 38 patients with recent myocardial infarction (MI). All patients had at least one completely occluded coronary artery corresponding to the infarct area. In patients with good collaterals, stress induced transient enlargement of the perfusion defect, however, in those with poor or no collaterals the enlargement did not occur (p less than 0.05). Wall motion abnormality on LVG was significantly milder in the former patients than in the latter (p less than 0.001). Transient enlargement of the perfusion defect after stress and milder left ventricular asynergy were more frequently observed in patients with anterior MI and good collaterals. These observations indicate that good collaterals may keep some myocardium in the peri-infarct zone viable

  1. The association between circulating endothelial progenitor cells and coronary collateral formation.

    Science.gov (United States)

    Tokgözoğlu, Lale; Yorgun, Hikmet; Gürses, Kadri Murat; Canpolat, Uğur; Ateş, Ahmet Hakan; Tülümen, Erol; Kaya, Ergün Barış; Aytemir, Kudret; Kabakçı, Giray; Tuncer, Murat; Oto, Ali

    2011-12-01

    We investigated the relationship between coronary collateral formation and circulating endothelial progenitor cells (EPC) in patients undergoing coronary angiography. Circulating CD133(+)/34(+) and CD34(+)/KDR(+) EPCs were determined in 68 patients (normal coronary vessels in 24 patients and coronary artery disease (CAD) in 44 patients) (age: 58.7 ± 10.1, 64.7% male). Circulating EPCs were higher among patients with normal coronary vessels compared to patients with CAD for CD133(+)/34(+) (p collateral formation (p collateral formation after adjustment for other cardiovascular risk factors and extent of CAD (p = 0.037). In patients with severe coronary stenosis, those with increased circulating EPCs had better collateral formation compared to those with lower EPC counts. Our findings implicate that in addition to presence of critical stenosis, intact response of bone marrow is necessary for collateral formation in CAD. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  2. Prominence and tornado dynamics observed with IRIS and THEMIS

    Science.gov (United States)

    Schmieder, Brigitte; Levens, Peter; Labrosse, Nicolas; Mein, Pierre; Lopez Ariste, Arturo; Zapior, Maciek

    2017-08-01

    Several prominences were observed during campaigns in September 2013 and July 2014 with the IRIS spectrometer and the vector magnetograph THEMIS (Tenerife). SDO/AIA and IRIS provided images and spectra of prominences and tornadoes corresponding to different physical conditions of the transition region between the cool plasma and the corona. The vector magnetic field was derived from THEMIS observations by using the He D3 depolarisation due to the magnetic field. The inversion code (PCA) takes into account the Hanle and Zeeman effects and allows us to compute the strength and the inclination of the magnetic field which is shown to be mostly horizontal in prominences as well as in tornadoes. Movies from SDO/AIA in 304 A and Hinode/SOT in Ca II show the highly dynamic nature of the fine structures. From spectra in Mg II and Si IV lines provided by IRIS and H-alpha observed by the Multi-channel Subtractive Double Pass (MSDP) spectrograph in the Meudon Solar Tower we derived the Doppler shifts of the fine structures and reconstructed the 3D structure of tornadoes. We conclude that the apparent rotation of AIA tornadoes is due to large-scale quasi-periodic oscillations of the plasma along more or less horizontal magnetic structures.

  3. Pattern of venous collateral development after splenic vein occlusion in an extended Whipple procedure : comparison with collateral vein pattern in cases of sinistral portal hypertension.

    Science.gov (United States)

    Strasberg, Steven M; Bhalla, Sanjeev; Sanchez, Luis A; Linehan, David C

    2011-11-01

    The risks of developing sinistral portal hypertension as a result of occlusion of the splenic vein close to its termination during a Whipple procedure are unclear. Our purpose was to compare the pattern of venous collateral development after splenic vein ligation in an extended Whipple procedure with the pattern of collateral development in cases of sinistral portal hypertension. Five patients underwent an extended Whipple procedure in which the splenic vein was divided and not reconstructed. Six to eight months later detailed mapping of venous return from the spleen was determined by contrast-enhanced multidetector computed tomography or in one case by 3D contrast-enhanced MRI. Spleen size and length of residual patent splenic vein were also measured. The literature on sinistral portal hypertension was evaluated to ascertain whether the venous collateral pattern in cases of left-sided portal hypertension was similar to the pattern that developed when the splenic vein was ligated at its termination in the Whipple procedure. A length of splenic vein remained patent in all five patients, measuring 4.5 to 11.5 cm from the spleen. Splenomegaly did not develop. Blood returned from the spleen by multiple collaterals including collaterals in the omentum and mesocolon. These types of collaterals do not develop in sinistral portal hypertension, nor is residual patent splenic vein seen. Ligation of the splenic vein close to its termination in five patients resulted in a pattern of venous return different from patients that have developed left-sided portal hypertension.

  4. 31 CFR 363.58 - May book-entry savings bonds be pledged or used as collateral?

    Science.gov (United States)

    2010-07-01

    ... pledged or used as collateral? 363.58 Section 363.58 Money and Finance: Treasury Regulations Relating to...Direct General § 363.58 May book-entry savings bonds be pledged or used as collateral? Bonds may not be pledged or used as collateral for the performance of an obligation. ...

  5. 13 CFR 120.1882 - What happens if funds to make required loan payments are not generated from the Collateral?

    Science.gov (United States)

    2010-01-01

    ... required loan payments are not generated from the Collateral? 120.1882 Section 120.1882 Business Credit and... to make required loan payments are not generated from the Collateral? (a) The SISMBD is responsible... Collateral as set forth in the Loan Agreements, related documents and applicable law. (b) An SISMBD will have...

  6. 13 CFR 120.1881 - How are payments on the Collateral allocated between the SISMBD borrower and repayment of the...

    Science.gov (United States)

    2010-01-01

    ... are payments on the Collateral allocated between the SISMBD borrower and repayment of the SISMBD Loan? Unless otherwise provided in the Loan Agreements for a particular SISMBD Loan, any payment on Collateral... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false How are payments on the Collateral...

  7. 13 CFR 120.545 - What are SBA's policies concerning the liquidation of collateral and the sale of business loans...

    Science.gov (United States)

    2010-01-01

    ... the liquidation of collateral and the sale of business loans and physical disaster assistance loans... policies concerning the liquidation of collateral and the sale of business loans and physical disaster.... SBA or the Lender may liquidate collateral securing a loan if the loan is in default or there is no...

  8. Relationship Between Collateral Status, Contrast Transit, and Contrast Density in Acute Ischemic Stroke.

    Science.gov (United States)

    Kawano, Hiroyuki; Bivard, Andrew; Lin, Longting; Spratt, Neil J; Miteff, Ferdinand; Parsons, Mark W; Levi, Christopher R

    2016-03-01

    Collateral circulation is recognized to influence the life expectancy of the ischemic penumbra in acute ischemic stroke. The best method to quantify collateral status on acute imaging is uncertain. We aimed to determine the relationship between visual collateral status, quantitative collateral assessments, baseline computed tomographic perfusion measures, and tissue outcomes on follow-up imaging. Sixty-six consecutive patients with acute ischemic stroke clinically eligible for recanalization therapy and with M1 or M2 middle cerebral artery occlusion were evaluated. We compared the visual collateral scoring with measures of contrast peak time delay and contrast peak density. We also compared these measures for their ability to predict perfusion lesion and infarct core volumes, final infarct, and infarct growth. Shorter contrast peak time delay (P=0.041) and higher contrast peak density (P=0.002) were associated with good collateral status. Shorter contrast peak time delay correlated with higher contrast peak density (β=-4.413; P=0.037). In logistic regression analysis after adjustment for age, sex, onset-computed tomographic time, and occlusion site, higher contrast peak density was independently associated with good collateral status (P=0.009). Multiple regression analysis showed that higher contrast peak density was an independent predictor of smaller perfusion lesion volume (P=0.029), smaller ischemic core volume (P=0.044), smaller follow-up infarct volume (P=0.005), and smaller infarct growth volume (P=0.010). Visual collateral status, contrast peak density, and contrast peak time delay were inter-related, and good collateral status was strongly associated with contrast peak density. Contrast peak density in collateral vessel may be an important factor in tissue fate in acute ischemic stroke. © 2016 American Heart Association, Inc.

  9. [As cardioprotective and angiogenic biomarker, can ghrelin predict coronary collateral development and severity of coronary atherosclerosis?

    Science.gov (United States)

    Akboğa, Mehmet Kadri; Taçoy, Gülten; Yılmaz Demirtaş, Canan; Türkoğlu, Sedat; Boyacı, Bülent; Çengel, Atiye

    2017-06-01

    Ghrelin exerts protective effects on cardiovascular system by inhibiting progression of atherosclerosis, supression of vascular inflammation, and stimulating angiogenesis. Thus, the aim of this study was to investigate the effect of serum ghrelin on coronary collateral development and SYNTAX score in patients with severe coronary artery disease. Total of 91 patients who had ≥90% stenosis in at least one major coronary artery were prospectively included in this cross-sectional, observational study. Collateral degree was graded according to Rentrop-Cohen classification. Patients with grade 2 or 3 collateral degree were allocated to Good Collateral Group and patients with grade 0 or 1 collateral degree were included in Poor Collateral Group. Ghrelin and vascular endothelial growth factor A (VEGF-A) levels were measured using radioimmunoassay and ELISA kits. Serum ghrelin and VEGF-A levels were significantly higher in Good Collateral Group. Furthermore, ghrelin level showed significant inverse correlation with SYNTAX score (r=0.348; p=0.001). In multivariable regression analysis, ghrelin (Odds ratio, 1.013; 95% confidence interval, 1.011-1.017; p=0.013), VEGF-A, fasting plasma glucose and presence of chronic total occlusion were independent predictors of good collateral development. In receiver operating characteristic curve analysis, ghrelin value cut-off point of ≥781 pg/mL predicted good collateral development with sensitivity of 73.1% and specificity of 67.7%. Findings suggested that ghrelin has antioxidant and antiinflammatory properties that protect endothelial functions and also stimulate angiogenesis, which results in development of good coronary collateral and inhibition of progression of coronary atherosclerosis.

  10. Coronary collaterals and risk for restenosis after percutaneous coronary interventions: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Meier Pascal

    2012-06-01

    Full Text Available Abstract Background The benefit of the coronary collateral circulation (natural bypass network on survival is well established. However, data derived from smaller studies indicates that coronary collaterals may increase the risk for restenosis after percutaneous coronary interventions. The purpose of this systematic review and meta-analysis of observational studies was to explore the impact of the collateral circulation on the risk for restenosis. Methods We searched the MEDLINE, EMBASE and ISI Web of Science databases (2001 to 15 July 2011. Random effects models were used to calculate summary risk ratios (RR for restenosis. The primary endpoint was angiographic restenosis > 50%. Results A total of 7 studies enrolling 1,425 subjects were integrated in this analysis. On average across studies, the presence of a good collateralization was predictive for restenosis (risk ratio (RR 1.40 (95% CI 1.09 to 1.80; P = 0.009. This risk ratio was consistent in the subgroup analyses where collateralization was assessed with intracoronary pressure measurements (RR 1.37 (95% CI 1.03 to 1.83; P = 0.038 versus visual assessment (RR 1.41 (95% CI 1.00 to 1.99; P = 0.049. For the subgroup of patients with stable coronary artery disease (CAD, the RR for restenosis with 'good collaterals' was 1.64 (95% CI 1.14 to 2.35 compared to 'poor collaterals' (P = 0.008. For patients with acute myocardial infarction, however, the RR for restenosis with 'good collateralization' was only 1.23 (95% CI 0.89 to 1.69; P = 0.212. Conclusions The risk of restenosis after percutaneous coronary intervention (PCI is increased in patients with good coronary collateralization. Assessment of the coronary collateral circulation before PCI may be useful for risk stratification and for the choice of antiproliferative measures (drug-eluting stent instead bare-metal stent, cilostazol.

  11. [Synopsis about the hypothesis of "information channel" of channel-collateral system].

    Science.gov (United States)

    Chang, Xi-Lang

    2008-10-01

    The author of the present paper founded a theorem about the "incompleteness of single channel structure" (nerve, blood vessel, lymphatic, interspace, aperture, etc.) through quantitative and qualitative analysis about the economic information channel in the human body, which eliminates the probability of single channel structure in the information channel of channel (meridian)-collateral system. After comprehensive analysis on the current researches, the author puts forward a neodoxy, i.e., the body "information channel" structure of the channel-collateral system, mainly follows the distribution regularity of systemic statistics, and is not a single specific entity; various layers of the information channel in the main stems of the channel-collaterals are composed of optimized structure tissues. Hence, the structure of this information channel of channel-collateral system is an overall-optimized, sequential and compatible systemic structure. From this neodoxy, the author brings forward a working principle of channel-collaterals, which is supported theoretically by bio-auxology. The longitudinal distribution of the main stems of meridian-collaterals is considered to result from that in the process of the animal evolution, in the animals moving forward, the microscopic complicated movement of intracorporeal information and energy molecules is related to the forward macroscopic and non-uniform movement of organism in trans-measure. Its impulse and kinetic momentum forms a main vector in the longitudinal direction of the body (the direction of the main stem of channel-collaterals). In order to adapt to and utilize natural regularities, the main stems of the channel-collaterals gradually differentiate and evolve in the living organism, forming a whole system. The "hypothesis of biological origin of channel-collateral system" and "that of information channel of the channel-collaterals in the body" constitute a relatively complete theoretical system framework.

  12. Synthetic differential emission measure curves of prominence fine structures. II. The SoHO/SUMER prominence of 8 June 2004

    Czech Academy of Sciences Publication Activity Database

    Gunár, Stanislav; Parenti, S.; Anzer, U.; Heinzel, Petr; Vial, J. C.

    2011-01-01

    Roč. 535, November (2011), A122/1-A122/11 ISSN 0004-6361 R&D Projects: GA ČR GP205/09/P554; GA ČR GA205/09/1705; GA ČR GAP209/10/1706 Institutional research plan: CEZ:AV0Z10030501 Keywords : Sun * filaments * prominences Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.587, year: 2011

  13. Significance of collateral vessels on the prediction of superior vena cava syndrome on CT

    International Nuclear Information System (INIS)

    Kim, Hyun Sook; Kim, Hyung Jin; Lee, Hyeng Gon; Ahn, In Oak; Chung, Sung Hoon

    1993-01-01

    Although visible collateral vessels on computed tomography (CT) has been considered as an important finding in superior vena cava (SVC) syndrome, there is no systematical analysis concerning correlation between the CT evidence of collateral vessels and clinical evidence of SVC syndrome. The purpose of this study is to evaluate how accurately we predict the clinical presence of SVC syndrome by the collateral vessels in patients with apparent SVC obstruction in CT. Forty seven patients having a CT evidence of obstruction or compression of SVC and/or its major tributaries were included in this study. Lung cancer was the most common underlying disease (n=40). The enhanced CT scans were obtained through either arm vein using a combined bolus and drip-infusion technique. Analyzing the CT scans, we particularly paid attention to the site and pattern of venous compromise, presence of collateral vessels, and if present, their location, without knowing whether symptoms and sign were present or nor, and then compared them with clinical data by a thorough review of charts, To verify the frequency of visible collateral vessels in normal subjects, we also evaluated the CT scans of 50 patients without mediastinal disease and clinical SVC syndrome as a control group. On CT, collateral vessels were found in 24 patients, among whom three patient had a single collateral and 21 patients had two or more collateral channels. There were two false positive cases, in which clinically overt SVC syndrome appeared 10 days and three months after CT examination respectively, and one false negative case. The presence of collateral vessels on CT, respectively, and one false negative case. The presence of collateral vessels on CT, regardless of the number and location of collateral vessels and pattern of venous obstruction, was a good clue for predicting the presence of clinical SVC syndrome with the sensitivity and the specificity of 95.7% and 91.7%, respectively. In control group, collateral

  14. An elevated level of BNP in plasma is related to the development of good collateral circulation in coronary artery disease.

    Science.gov (United States)

    Xi, Wei-Wei; Cheng, Gang; Lv, Shumin; Gao, Qinqin; Bu, Gang; Zhou, Ying; Xu, Geng

    2011-12-01

    B-type natriuretic peptide (BNP) was recently demonstrated to be a potential stimulator of angiogenesis and arteriogenesis. The correlation between BNP level and collateral formation in patients with coronary artery disease (CAD) has not been reported. The study included 311 consecutive patients who underwent coronary angiography were divided into three groups according to coronary angiography and collateral formation: normal group (100 patients with normal coronary angiographic findings); poor collateral group (116 patients with at least one coronary stenosis of ≥75% without visible collateral circulation); and good collateral group (95 patients with at least one coronary stenosis of ≥75% with well-developed collateral circulation). Collateral score was analyzed using the Cohen-Rentrop classification. Plasma BNP levels were 45.77 ± 4.66 pg/ml, 116.40 ± 28.15 pg/ml, and 254.20 ± 42.85 pg/ml for patients in normal, poor collateral, and good collateral groups, respectively. Plasma BNP levels in the latter were significantly higher than in the normal group (p collateral group (p collateral group and poor collateral group when compared with left ventricular ejection fraction (LVEF), left ventricular dimensions at end diastole (LVEDd), age, severity of angiographic disease, and other cardiovascular risk factors. After adjustment in the multiple ordinal logistic regression model, plasma BNP levels showed a strong independent association with collateral Cohen-Rentrop score (χ(2 )= 5.636, OR = 1.002, 95% CI 1.000-1.004, p = 0.018). An elevated level of BNP in plasma is independently associated with collateral development; patients with good collaterals tend to have a higher BNP level.

  15. ARE GIANT TORNADOES THE LEGS OF SOLAR PROMINENCES?

    Energy Technology Data Exchange (ETDEWEB)

    Wedemeyer, Sven; Scullion, Eamon; Rouppe van der Voort, Luc; Bosnjak, Antonija [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, NO-0315 Oslo (Norway); Antolin, Patrick, E-mail: sven.wedemeyer@astro.uio.no [Centre for Mathematical Plasma Astrophysics, Department of Mathematics, KU Leuven, Celestijnenlaan 200B, bus 2400, B-3001 Leuven (Belgium)

    2013-09-10

    Observations in the 171 A channel of the Atmospheric Imaging Assembly of the space-borne Solar Dynamics Observatory show tornado-like features in the atmosphere of the Sun. These giant tornadoes appear as dark, elongated, and apparently rotating structures in front of a brighter background. This phenomenon is thought to be produced by rotating magnetic field structures that extend throughout the atmosphere. We characterize giant tornadoes through a statistical analysis of properties such as spatial distribution, lifetimes, and sizes. A total number of 201 giant tornadoes are detected in a period of 25 days, suggesting that, on average, about 30 events are present across the whole Sun at a time close to solar maximum. Most tornadoes appear in groups and seem to form the legs of prominences, thus serving as plasma sources/sinks. Additional H{alpha} observations with the Swedish 1 m Solar Telescope imply that giant tornadoes rotate as a structure, although they clearly exhibit a thread-like structure. We observe tornado groups that grow prior to the eruption of the connected prominence. The rotation of the tornadoes may progressively twist the magnetic structure of the prominence until it becomes unstable and erupts. Finally, we investigate the potential relation of giant tornadoes to other phenomena, which may also be produced by rotating magnetic field structures. A comparison to cyclones, magnetic tornadoes, and spicules implies that such events are more abundant and short-lived the smaller they are. This comparison might help to construct a power law for the effective atmospheric heating contribution as a function of spatial scale.

  16. ARE GIANT TORNADOES THE LEGS OF SOLAR PROMINENCES?

    International Nuclear Information System (INIS)

    Wedemeyer, Sven; Scullion, Eamon; Rouppe van der Voort, Luc; Bosnjak, Antonija; Antolin, Patrick

    2013-01-01

    Observations in the 171 Å channel of the Atmospheric Imaging Assembly of the space-borne Solar Dynamics Observatory show tornado-like features in the atmosphere of the Sun. These giant tornadoes appear as dark, elongated, and apparently rotating structures in front of a brighter background. This phenomenon is thought to be produced by rotating magnetic field structures that extend throughout the atmosphere. We characterize giant tornadoes through a statistical analysis of properties such as spatial distribution, lifetimes, and sizes. A total number of 201 giant tornadoes are detected in a period of 25 days, suggesting that, on average, about 30 events are present across the whole Sun at a time close to solar maximum. Most tornadoes appear in groups and seem to form the legs of prominences, thus serving as plasma sources/sinks. Additional Hα observations with the Swedish 1 m Solar Telescope imply that giant tornadoes rotate as a structure, although they clearly exhibit a thread-like structure. We observe tornado groups that grow prior to the eruption of the connected prominence. The rotation of the tornadoes may progressively twist the magnetic structure of the prominence until it becomes unstable and erupts. Finally, we investigate the potential relation of giant tornadoes to other phenomena, which may also be produced by rotating magnetic field structures. A comparison to cyclones, magnetic tornadoes, and spicules implies that such events are more abundant and short-lived the smaller they are. This comparison might help to construct a power law for the effective atmospheric heating contribution as a function of spatial scale

  17. Severe Degeneration of the Medial Collateral Ligament in Hallux Valgus: A Histopathologic Study in 12 Consecutive Patients

    Science.gov (United States)

    Prasitdumrong, Ittipol; Rungprai, Chamnanni; Reeboonlarb, Nitit; Poonpracha, Tara; Phisitkul, Phinit

    2013-01-01

    Objective To determine the degree and location of degenerative changes of the medial collateral ligament of the first metatarsophalangeal joint, using the lateral collateral ligament as a control, in patients undergoing hallux valgus correction. Materials and Methods A strip of medial and lateral collateral ligaments were biopsied from 12 consecutive patients (age 45 ± 4.8 years) with symptomatic hallux valgus. A blinded analysis of histopathology was performed by an experienced pathologist. Results The medial collateral ligament was significantly more degenerated compared to the lateral collateral ligament (x2 = 23.41, DF = 2, p hallux valgus correction. The Authors received no financial support for this study. PMID:24027461

  18. The cerebral collateral circulation: Relevance to pathophysiology and treatment of stroke.

    Science.gov (United States)

    Ginsberg, Myron D

    2017-08-09

    The brain's collateral circulation consists of arterial anastomotic channels capable of providing nutrient perfusion to brain regions whose normal sources of flow have become compromised, as occurs in acute ischemic stroke. Modern CT-based neuroimaging is capable of providing detailed information as to collateral extent and sufficiency and is complemented by magnetic resonance-based methods. In the present era of standard-of-care IV thrombolysis for acute ischemic stroke, and following the recent therapeutic successes of randomized clinical trials of acute endovascular intervention, the sufficiency of the collateral circulation has been convincingly established as a key factor influencing the likelihood of successful reperfusion and favorable clinical outcome. This article reviews the features of the brain's collateral circulation; methods for its evaluation in the acute clinical setting; the relevance of collateral circulation to prognosis in acute ischemic stroke; the specific insights into the collateral circulation learned from recent trials of endovascular intervention; and the major influence of genetic factors. Finally, we emphasize the need to develop therapeutic approaches to augment collateral perfusion as an adjunctive strategy to be employed along with, or prior to, thrombolysis and endovascular interventions, and we highlight the possible potential of inhaled nitric oxide, albumin, and other approaches. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Effective collateral circulation may indicate improved perfusion territory restoration after carotid endarterectomy.

    Science.gov (United States)

    Lin, Tianye; Lai, Zhichao; Lv, Yuelei; Qu, Jianxun; Zuo, Zhentao; You, Hui; Wu, Bing; Hou, Bo; Liu, Changwei; Feng, Feng

    2018-02-01

    To investigate the relationship between the level of collateral circulation and perfusion territory normalisation after carotid endarterectomy (CEA). This study enrolled 22 patients with severe carotid stenosis that underwent CEA and 54 volunteers without significant carotid stenosis. All patients were scanned with ASL and t-ASL within 1 month before and 1 week after CEA. Collateral circulation was assessed on preoperative ASL images based on the presence of ATA. The postoperative flow territories were considered as back to normal if they conformed to the perfusion territory map in a healthy population. Neuropsychological tests were performed on patients before and within 7 days after surgery. ATA-based collateral score assessed on preoperative ASL was significantly higher in the flow territory normalisation group (n=11, 50 %) after CEA (P mean differences+2SD among control (MMSE=1.35, MOCA=1.02)]. This study demonstrated that effective collateral flow in carotid stenosis patients was associated with normalisation of t-ASL perfusion territory after CEA. The perfusion territory normalisation group tends to have more cognitive improvement after CEA. • Evaluation of collaterals before CEA is helpful for avoiding ischaemia during clamping. • There was good agreement on ATA-based ASL collateral grading. • Perfusion territories in carotid stenosis patients are altered. • Patients have better collateral circulation with perfusion territory back to normal. • MMSE and MOCA test scores improved more in the territory normalisation group.

  20. Assessment of the significance of coronary collateral vessel by using thallium-201 myocardial imaging

    International Nuclear Information System (INIS)

    Kanoh, Yasushi; Shiotani, Hideyuki; Fukuzaki, Hisashi; Maeda, Kazumi.

    1988-01-01

    For functional assessment of coronary collateral vessels, twenty-three patients with effort angina pectoris who had total coronary obstruction were studied. The patients were divided depending on the degree of development of collateral vessels into two groups, i.e. good collateral group I (n = 13) and poor collateral group II (n = 10). Thallium-201 scan was performed immediately (Ex-1 image), 20 minutes (Ex-2 image) after exercise and after nitroglycerin administration (NTG image) respectively. In all images, the relative percent activity of thallium-201 in the collateral-dependent ischemic area to the normal myocardium were calculated and were compaired between two groups. Relative percent activities in group I and II were as follows : Ex-1 image ; 75.8 ± 3.5 % vs. 77.2 ± 2.9 % (NS), Ex-2 images ; 85.3 ± 4.5 % vs. 79.3 ± 3.9 % (p < 0.005), NTG image ; 97.3 ± 3.1 % vs. 96.4 ± 5.2 % (NS). From these results, it was elucidated that good collateral induced early partial redistribution in its perfusion area, suggesting that good collateral circulation may provide rapid recovery from myocardial ischemia. (author)

  1. Relationship between haemodynamic impairment and collateral blood flow in carotid artery disease.

    Science.gov (United States)

    Hartkamp, Nolan S; Petersen, Esben T; Chappell, Michael A; Okell, Thomas W; Uyttenboogaart, Maarten; Zeebregts, Clark J; Bokkers, Reinoud Ph

    2017-01-01

    Collateral blood flow plays a pivotal role in steno-occlusive internal carotid artery (ICA) disease to prevent irreversible ischaemic damage. Our aim was to investigate the effect of carotid artery disease upon cerebral perfusion and cerebrovascular reactivity and whether haemodynamic impairment is influenced at brain tissue level by the existence of primary and/or secondary collateral. Eighty-eight patients with steno-occlusive ICA disease and 29 healthy controls underwent MR examination. The presence of collaterals was determined with time-of-flight, two-dimensional phase contrast MRA and territorial arterial spin labeling (ASL) imaging. Cerebral blood flow and cerebrovascular reactivity were assessed with ASL before and after acetazolamide. Cerebral haemodynamics were normal in asymptomatic ICA stenosis patients, as opposed to patients with ICA occlusion, in whom the haemodynamics in both hemispheres were compromised. Haemodynamic impairment in the affected brain region was always present in symptomatic patients. The degree of collateral blood flow was inversely correlated with haemodynamic impairment. Recruitment of secondary collaterals only occurred in symptomatic ICA occlusion patients. In conclusion, both CBF and cerebrovascular reactivity were found to be reduced in symptomatic patients with steno-occlusive ICA disease. The presence of collateral flow is associated with further haemodynamic impairment. Recruitment of secondary collaterals is associated with severe haemodynamic impairment.

  2. Measuring the collateral network pressure to minimize paraplegia risk in thoracoabdominal aneurysm resection.

    Science.gov (United States)

    Etz, Christian D; Zoli, Stefano; Bischoff, Moritz S; Bodian, Carol; Di Luozzo, Gabriele; Griepp, Randall B

    2010-12-01

    To minimize paraplegia during thoracoabdominal aortic aneurysm repair, the concept of the collateral network was developed. That is, spinal cord perfusion is provided by an interconnecting complex of vessels in the intraspinal, paraspinous, and epidural space and in the paravertebral muscles, including intercostal and lumbar segmental as well as subclavian and hypogastric arteries. Collateral network pressure was measured with a catheter in the distal end of a ligated segmental artery in pigs and human beings. In the pig, collateral network pressure was 75% of the simultaneous mean aortic pressure. With complete segmental arterial ligation, it fell to 27% of baseline, recovering to 40% at 24 hours and 90% at 120 hours. Spinal cord injury occurred in approximately 50% of animals. When all segmental arteries were taken in 2 stages a week apart, collateral network pressure fell only to 50% to 70% of baseline, and spinal cord injury was rare. In human beings, baseline collateral network pressure also was 75% of mean aortic pressure, fell in proportion to the number of segmental arteries ligated, and began recovery within 24 hours. Collateral network pressure was lower with nonpulsatile distal bypass than with pulsatile perfusion. After subtraction of a measure of spinal cord outflow pressure (cerebrospinal fluid pressure or central venous pressure), collateral network pressure provides a clinically useful estimate of spinal cord perfusion pressure. Copyright © 2010. Published by Mosby, Inc.

  3. Photoionization of Endohedral Atoms: Collective, Reflective and Collateral Emissions

    International Nuclear Information System (INIS)

    Chakraborty, Himadri S.; McCune, Matthew A.; Hopper, Dale E.; Madjet, Mohamed E.; Manson, Steven T.

    2009-01-01

    The photoionization properties of a fullerene-confined atom differ dramatically from that of an isolated atom. In the low energy region, where the fullerene plasmons are active, the electrons of the confined atom emerge through a collective channel carrying a significant chunk of plasmon with it. The photoelectron angular distribution of the confined atom however shows far lesser impact of the effect. At higher energies, the interference between two single-electron ionization channels, one directly from the atom and another reflected off the fullerene cage, producuces oscillatory cross sections. But for the outermost atomic level, which transfers some electrons to the cage, oscillations are further modulated by the collateral emission from the part of the atomic charge density transferred to the cage. These various modes of emissions are studied for the photoionization of Ar endohedrally confined in C 60 .

  4. On Security of Collateral in Danish Mortgage Finance

    DEFF Research Database (Denmark)

    Haldrup, Karin

    2017-01-01

    on the balance principle that assigns risks and responsibility to market players in a self-disciplinary manner and protected the mortgage banks against cash flow mismatches even during deep crisis, as history attests. It is shown how property registers and effective enforcement have created transparent property......Specialized mortgage intermediaries in Denmark have for over two hundred years provided owners and buyers of real property wide access to credit. The present paper sets out to explore the safeguards that nurtured development of a robust, market based financing system and a deep mortgage market....... Observations are made on the nature of collateral performance in respect to property rights, mortgage law and market development in search of general features of required institutional arrangements. The robustness of the Danish mortgage finance system is largely accredited to the securitization model based...

  5. The Relation between Collateral Circulation and 99mTc-MIBI Heart SPECT

    International Nuclear Information System (INIS)

    Kim, Jae Man; Na, Deug Young; Park, Eun Kyung

    1994-01-01

    The coronary collateral vessels have revealed their significance in terms of reduction of infarct size, preservation left ventricular function, and prevention of left ventricular aneurysm in patients with myocardial infarction. The purpose of this study were to evaluated the relation between collateral circulation and 99m Tc-MIBI Heart SPECT in patient with acute myocardial infarction and their clinical significance. The fifty six MI patients with antegrade TIMI perfusion grade 0 and 1 were studied. The patients were classified into two groups; Group I included 30 patients with grade 2, 3 Collateral flow. Group II included 26 patients with grade 0, 1 Collateral flow. Collateral filling were graded from 0 to 3; 0- none, 1- Filling of side branch only, 2- Partial filling of the epicardial segment, 3- Complete filling of epicardial segment. Clinical variables, left ventricular function, 99m Tc-MIBI Heart SPECT were analyzed with angiographic finding. Results were following: 1) Collateral visualization was found to be greater in patient with involvement of right coronary artery (RCA). The collateral development site of infarct related artery was RCA 15 cases, left anterior descending artery (LAD) 10 cases, left circumflex artery (LCX) 5 cases, and the collateral circulation from LAD to RCA was 13 cases (40.6%). 2) There was a tendency to be decreased in peak CK activity with group I . 3) The presence of good collateral channels was more frequently 99m Tc-MIBI reversible perfusion defect (83.4% vs 15.3%, p 99m Tc-MlBI reversible perfusion defect.

  6. Collateral blood flow in different cerebrovascular hierarchy provides endogenous protection in cerebral ischemia.

    Science.gov (United States)

    Luo, Chuanming; Liang, Fengyin; Ren, Huixia; Yao, Xiaoli; Liu, Qiang; Li, Mingyue; Qin, Dajiang; Yuan, Ti-Fei; Pei, Zhong; Su, Huanxing

    2017-11-01

    Collateral blood flow as vascular adaptions to focal cerebral ischemia is well recognized. However, few studies directly investigate the dynamics of collateral vessel recruitment in vivo and little is known about the effect of collateral blood flow in different cerebrovascular hierarchy on the neuropathology after focal ischemic stroke. Here, we report that collateral blood flow is critically involved in blood vessel compensations following regional ischemia. We occluded a pial arteriole using femtosecond laser ablating under the intact thinned skull and documented the changes of collateral flow around the surface communication network and between the surface communication network and subsurface microcirculation network using in vivo two photon microscopy imaging. Occlusion of the pial arteriole apparently increased the diameter and collateral blood flow of its leptomeningeal anastomoses, which significantly reduced the cortical infarction size. This result suggests that the collateral flow via surface communicating network connected with leptomeningeal anastomoses could greatly impact on the extent of infarction. We then further occluded the target pial arteriole and all of its leptomeningeal anastomoses. Notably, this type of occlusion led to reversals of blood flow in the penetrating arterioles mainly proximal to the occluded pial arteriole in a direction from the subsurface microcirculation network to surface arterioles. Interesting, the cell death in the area of ischemic penumbra was accelerated when we performed occlusion to cease the reversed blood flow in those penetrating arterioles, suggesting that the collateral blood flow from subsurface microcirculation network exerts protective roles in delaying cell death in the ischemic penumbra. In conclusion, we provide the first experimental evidence that collateral blood vessels at different cerebrovascular hierarchy are endogenously compensatory mechanisms in brain ischemia. © 2016 International Society of

  7. Alternative Evolutionary Paths to Bacterial Antibiotic Resistance Cause Distinct Collateral Effects.

    Science.gov (United States)

    Barbosa, Camilo; Trebosc, Vincent; Kemmer, Christian; Rosenstiel, Philip; Beardmore, Robert; Schulenburg, Hinrich; Jansen, Gunther

    2017-09-01

    When bacteria evolve resistance against a particular antibiotic, they may simultaneously gain increased sensitivity against a second one. Such collateral sensitivity may be exploited to develop novel, sustainable antibiotic treatment strategies aimed at containing the current, dramatic spread of drug resistance. To date, the presence and molecular basis of collateral sensitivity has only been studied in few bacterial species and is unknown for opportunistic human pathogens such as Pseudomonas aeruginosa. In the present study, we assessed patterns of collateral effects by experimentally evolving 160 independent populations of P. aeruginosa to high levels of resistance against eight commonly used antibiotics. The bacteria evolved resistance rapidly and expressed both collateral sensitivity and cross-resistance. The pattern of such collateral effects differed to those previously reported for other bacterial species, suggesting interspecific differences in the underlying evolutionary trade-offs. Intriguingly, we also identified contrasting patterns of collateral sensitivity and cross-resistance among the replicate populations adapted to the same drug. Whole-genome sequencing of 81 independently evolved populations revealed distinct evolutionary paths of resistance to the selective drug, which determined whether bacteria became cross-resistant or collaterally sensitive towards others. Based on genomic and functional genetic analysis, we demonstrate that collateral sensitivity can result from resistance mutations in regulatory genes such as nalC or mexZ, which mediate aminoglycoside sensitivity in β-lactam-adapted populations, or the two-component regulatory system gene pmrB, which enhances penicillin sensitivity in gentamicin-resistant populations. Our findings highlight substantial variation in the evolved collateral effects among replicates, which in turn determine their potential in antibiotic therapy. © The Author 2017. Published by Oxford University Press on

  8. Negative modulation of presynaptic activity by zinc released from Schaffer collaterals.

    Science.gov (United States)

    Takeda, Atsushi; Fuke, Sayuri; Tsutsumi, Wataru; Oku, Naoto

    2007-12-01

    The role of zinc in excitation of Schaffer collateral-CA1 pyramidal cell synapses is poorly understood. Schaffer collaterals stained with ZnAF-2 or ZnAF-2DA, a membrane-impermeable or a membrane-permeable zinc indicator, respectively, were treated by tetanic stimulation (200 Hz, 1 sec). Extracellular and intracellular ZnAF-2 signals were increased in the stratum radiatum of the CA1, in which Schaffer collateral synapses exist. Both the increases were completely blocked in the presence of 1 mM CaEDAT, a membrane-impermeable zinc chelator, suggesting that 1 mM CaEDTA is effective for chelating zinc released from Schaffer collaterals. The role of Schaffer collateral zinc in presynaptic activity was examined by using FM4-64, a fluorescent indicator for vesicular exocytosis. The decrease in FM4-64 signal during tetanic stimulation (10 Hz, 180 sec) was enhanced in Schaffer collaterals in the presence of 1 mM CaEDTA but suppressed in the presence of 5 microM ZnC1(2), suggesting that zinc released from Schaffer collaterals suppresses presynaptic activity during tetanic stimulation. When Schaffer collateral synapses stained with calcium orange AM, a membrane-permeable calcium indicator, were regionally stimulated with 1 mM glutamate, calcium orange signal was increased in the CA1 pyramidal cell layer. This increase was enhanced in the presence of CaEDTA and attenuated in the presence of zinc. These results suggest that zinc attenuates excitation of Schaffer collateral synapses elicited with glutamate via suppression of presynaptic activity. (c) 2007 Wiley-Liss, Inc.

  9. Stress changes of lateral collateral ligament at different

    Directory of Open Access Journals (Sweden)

    ZHONG Yan-lin

    2011-04-01

    Full Text Available 【Abstract】 Objective: To create a 3-dimensional finite element model of knee ligaments and to analyse the stress changes of lateral collateral ligament (LCL with or without displaced movements at different knee flexion conditions. Methods: A four-major-ligament contained knee specimen from an adult died of skull injury was prepared for CT scanning with the detectable ligament insertion footprints, locations and orientations precisely marked in advance. The CT scanning images were converted to a 3-dimensional model of the knee with the 3-dimensional reconstruction technique and transformed into finite element model by the software of ANSYS. The model was validated using experimental and numerical results obtained by other scientists. The natural stress changes of LCL at five different knee flexion angles (0°, 30°, 60°, 90°, 120° and under various motions of anterior-posterior tibial translation, tibial varus rotation and internal-external tibial rotation were measured. Results: The maximum stress reached to 87%-113% versus natural stress in varus motion at early 30° of knee flexions. The stress values were smaller than the peak value of natural stress at 0° (knee full extension when knee bending was over 60° of flexion in anterior-posterior tibial translation and internal-external rotation. Conclusion: LCL is vulnerable to varus motion in almost all knee bending positions and susceptible to anterior- posterior tibial translation or internal-external rotation at early 30° of knee flexions. Key words: Knee joint; Collateral ligaments; Finite element analysis

  10. 31 CFR 380.4 - What collateral may I pledge instead of a surety bond under 31 CFR part 225, and what value will...

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false What collateral may I pledge instead..., DEPARTMENT OF THE TREASURY BUREAU OF THE PUBLIC DEBT COLLATERAL ACCEPTABILITY AND VALUATION Acceptable Collateral and Its Valuation § 380.4 What collateral may I pledge instead of a surety bond under 31 CFR part...

  11. Perceptions of Social Responsibility of Prominent Animal Welfare Groups.

    Science.gov (United States)

    Widmar, Nicole J Olynk; Morgan, Carissa J; Croney, Candace C

    2018-01-01

    Nonhuman animal welfare is an increasingly important component of consumer expectations of corporate social responsibility (CSR). The extent to which prominent animal welfare or protection organizations may influence people's perceptions of food industry CSR may be related to an organization's perceived social responsibility. Data from an online survey of 300 U.S. residents were used to explore relationships between demographics/lifestyle choices and perceptions of prominent animal welfare organizations (using best-worst scaling methodology). Overall, the American Society for the Prevention of Cruelty to Animals was perceived to be the most socially responsible organization analyzed, followed by the Humane Society of the United States and the American Humane Association (AHA). Results suggest that the perceived social responsibility of animal protection organizations in this study was not strongly linked to personally (financially) supporting them, with 2 exceptions: the perceptions of People for the Ethical Treatment of Animals and AHA. Improved understanding of the perception of animal welfare or protection organizations can inform decision making by organizations interested in furthering animal welfare causes.

  12. Word-level prominence in Persian: An Experimental Study.

    Science.gov (United States)

    Sadeghi, Vahid

    2017-12-01

    Previous literature on the phonetics of stress in Persian has reported that fundamental frequency is the only reliable acoustic correlate of stress, and that stressed and unstressed syllables are not differentiated from each other in the absence of accentuation. In this study, the effects of lexical stress on duration, overall intensity and spectral tilt were examined in Persian both in the accented and unaccented conditions. Results showed that syllable duration is consistently affected by stress in Persian in both the accented and unaccented conditions across all vowel types. Unlike duration, the results for overall intensity and spectral tilt were significant only in the accented condition, suggesting that measures of intensity are not a correlate of stress in Persian but they are mainly caused by the presence of a pitch movement. The findings are phonologically interpreted as suggesting that word-level prominence in Persian is typologically similar to 'stress accent' languages, in which multiple phonetic cues are used to signal the prominence contrast in the accented condition, and stressed and unstressed syllables are different from each other even when the word is not pitch-accented.

  13. Magnetic field re-arrangement after prominence eruption

    International Nuclear Information System (INIS)

    Kopp, R.A.; Poletto, G.

    1986-01-01

    It has long been known that magnetic reconnection plays a fundamental role in a variety of solar events. Although mainly invoked in flare problems, large-scale loops interconnecting active regions, evolving coronal hole boundaries, the solar magnetic cycle itself, provide different evidence of phenomena which involve magnetic reconnection. A further example might be given by the magnetic field rearrangement which occurs after the eruption of a prominence. Since most often a prominence reforms after its disappearance and may be observed at about the same position it occupied before erupting, the magnetic field has to undergo a temporary disruption to relax back, via reconnection, to a configuration similar to the previous one. The above sequence of events is best observable in the case of two-ribbon (2-R) flares but most probably is associated with all filament eruptions. Even if the explanation of the magnetic field rearrangement after 2-R flares in terms of reconnection is generally accepted, the lack of a three-dimensional model capable of describing the field reconfiguration, has prevented, up to now, a thorough analysis of its topology as traced by Hα/x-ray loops. The purpose of the present work is to present a numerical technique which enables one to predict and visualize the reconnected configuration, at any time t, and therefore allows one to make a significant comparison of observations and model predictions throughout the whole process. 5 refs., 3 figs

  14. Collateral abdominal circulation in patient with Leriche's syndrome diagnosed with 64-row multislice computed tomography (MSCT)

    International Nuclear Information System (INIS)

    Staskiewicz, G.; Drop, A.

    2008-01-01

    Leriche's syndrome results from slowly developing occlusion of the abdominal aorta. It affects mainly middle-aged males. The blood flow distal to the occlusion site is secured by collateral circulation. Signs of Leriche's syndrome include claudication, gluteal pain and impotence. The paper presents a patient with Leriche's syndrome, in whom a detailed visualization of collateral circulation was obtained with multislice computed tomography angiography. Patient underwent surgical recanalization of the aorta with an excellent result. To our knowledge, the presented case is the first description of collateral circulation in Leriche's syndrome obtained with 64-row computed tomography. (author)

  15. Value of Quantitative Collateral Scoring on CT Angiography in Patients with Acute Ischemic Stroke.

    Science.gov (United States)

    Boers, A M M; Sales Barros, R; Jansen, I G H; Berkhemer, O A; Beenen, L F M; Menon, B K; Dippel, D W J; van der Lugt, A; van Zwam, W H; Roos, Y B W E M; van Oostenbrugge, R J; Slump, C H; Majoie, C B L M; Marquering, H A

    2018-06-01

    Many studies have emphasized the relevance of collateral flow in patients presenting with acute ischemic stroke. Our aim was to evaluate the relationship of the quantitative collateral score on baseline CTA with the outcome of patients with acute ischemic stroke and test whether the timing of the CTA acquisition influences this relationship. From the Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN) data base, all baseline thin-slice CTA images of patients with acute ischemic stroke with intracranial large-vessel occlusion were retrospectively collected. The quantitative collateral score was calculated as the ratio of the vascular appearance of both hemispheres and was compared with the visual collateral score. Primary outcomes were 90-day mRS score and follow-up infarct volume. The relation with outcome and the association with treatment effect were estimated. The influence of the CTA acquisition phase on the relation of collateral scores with outcome was determined. A total of 442 patients were included. The quantitative collateral score strongly correlated with the visual collateral score (ρ = 0.75) and was an independent predictor of mRS (adjusted odds ratio = 0.81; 95% CI, .77-.86) and follow-up infarct volume (exponent β = 0.88; P quantitative collateral score showed areas under the curve of 0.71 and 0.69 for predicting functional independence (mRS 0-2) and follow-up infarct volume of >90 mL, respectively. We found significant interaction of the quantitative collateral score with the endovascular therapy effect in unadjusted analysis on the full ordinal mRS scale ( P = .048) and on functional independence ( P = .049). Modification of the quantitative collateral score by acquisition phase on outcome was significant (mRS: P = .004; follow-up infarct volume: P quantitative collateral scoring in patients with acute ischemic stroke is a reliable and user-independent measure of the collateral

  16. PENGEMBANGAN HAK KEKAYAAN INTELEKTUAL SEBAGAI COLLATERAL (AGUNAN UNTUK MENDAPATKAN KREDIT PERBANKAN DI INDONESIA

    Directory of Open Access Journals (Sweden)

    Sri Mulyani

    2012-09-01

    Full Text Available Intellectual Property Rights is granted the exclusive rights to creators, inventors or designers for the creation or invention that has commercial value, either directly or through the automatic registration of the relevant agencies as awards, recognition should be given the protection of the rights of the community development law. Globally, the IPR will be used as collateral to obtain a bank loan internasional. In this law is necessary to realize the concept of legislation in each country who are willing to apply that regulate substance loading, binding, and registration of intellectual property as collateral. Key words: development of intellectual property rights, collateral, bank credit in Indonesia

  17. Injuries to the Collateral Ligaments of the Metacarpophalangeal Joint of the Thumb, Including Simultaneous Combined Thumb Ulnar and Radial Collateral Ligament Injuries, in National Football League Athletes.

    Science.gov (United States)

    Werner, Brian C; Belkin, Nicole S; Kennelly, Steve; Weiss, Leigh; Barnes, Ronnie P; Rodeo, Scott A; Warren, Russell F; Hotchkiss, Robert N

    2017-01-01

    Thumb collateral ligament injuries occur frequently in the National Football League (NFL). In the general population or in recreational athletes, pure metacarpophalangeal (MCP) abduction or adduction mechanisms yield isolated ulnar collateral ligament (UCL) and radial collateral ligament (RCL) tears, respectively, while NFL athletes may sustain combined mechanism injury patterns. To evaluate the incidence of simultaneous combined thumb UCL and RCL tears among all thumb MCP collateral ligament injuries in NFL athletes on a single team. Case series; Level of evidence, 4. A retrospective review of all thumb injuries on a single NFL team from 1991 to 2014 was performed. All players with a thumb MCP collateral ligament injury were included. Collateral ligament injuries were confirmed by review of both physical examination findings and magnetic resonance imaging. Player demographics, surgical details, and return-to-play data were obtained from the team electronic medical record and surgeons' records. A total of 36 thumbs in 32 NFL players were included in the study, yielding an incidence of 1.6 thumb MCP collateral ligament injuries per year on a single NFL team. Of these, 9 thumbs (25%) had a simultaneous combined UCL and RCL tear injury pattern confirmed on both physical examination and MRI. The remaining 27 thumbs (75%) were isolated UCL injuries. All combined UCL/RCL injuries required surgery due to dysfunction from instability; 63.0% of isolated UCL injuries required surgical repair ( P = .032) due to continued pain and dysfunction from instability. Repair, when required, was delayed until the end of the season. All players with combined UCL/RCL injuries and isolated UCL injuries returned to play professional football the following season. Simultaneous combined thumb UCL and RCL tear is a previously undescribed injury pattern that occurred in 25% of thumb MCP collateral ligament injuries on a single NFL team over a 23-year period. All players with combined thumb UCL

  18. Physics of solar prominences. Proceedings of the Colloquium, Oslo, Norway, August 14-18, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, E; Maltby, P

    1979-01-01

    These papers deal with recent theoretical and observational studies of the physics of solar prominences. Specific topics include reviews of prominence spectra and their interpretation, polarimetric observations and magnetic-field determination in prominences, observations of the prominence-corona interface, theories on the formation and stability of quiescent prominences, prominence classifications, observations of active prominences, observations and interpretations of coronal manifestations of eruptive prominences, and models of prominence structure and dynamics. Other contributions discuss simultaneous observations of Ca II and hydrogen Balmer lines in quiescent prominences, recent results in quiescent-prominence spectroscopy, the solar helium abundance obtained from optical spectra of quiescent prominences, and Stokes polarimetry of quiescent prominences in the He I D3 line. Magnetic-field determination based on the Hanle effect is also examined, along with the orientation of prominence microstructure relative to magnetic-field direction, radio observations of quiescent-prominence filaments at centimeter and millimeter wavelengths, EUV observations of filaments, and a magnetic-field reconnection model of quiescent prominences.

  19. Automatic detection of prominence (as defined by listeners' judgements) in read aloud Dutch sentences

    NARCIS (Netherlands)

    Streefkerk, B.M.; Pols, L.C.W.; ten Bosch, L.F.M.

    1998-01-01

    This paper describes a first step towards the automatic classification of prominence (as defined by native listeners). As a result of a listening experiment each word in 500 sentences was marked with a rating scale between `0' (non-prominent) and `10' (very prominent). These prominence labels are

  20. Vaccination elicits a prominent acute phase response in horses.

    Science.gov (United States)

    Andersen, Susanne A; Petersen, Henrik H; Ersbøll, Annette K; Falk-Rønne, Jørgen; Jacobsen, Stine

    2012-02-01

    European and American guidelines for vaccination against tetanus and influenza in horses recommend annual and annual/semi-annual vaccinations, respectively, against the two pathogens. Too-frequent vaccination may, however, have adverse effects, among other things because an inflammatory response is elicited with subsequent alterations in homeostasis. The objective of the study was to compare the acute phase response (APR) in 10 horses following administration of two different types of vaccines, namely, an inactivated Immune Stimulating COMplex (ISCOM) vaccine and a live recombinant vector vaccine. Blood was sampled before and after vaccination to measure levels of serum amyloid A (SAA), fibrinogen, white blood cell counts (WBC) and iron. Vaccination induced a prominent APR with increased WBC, elevated blood levels of SAA and fibrinogen, and decreased serum iron concentrations. The ISCOM vaccine caused significantly (Phorse owners about convalescence after vaccination. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Clinical Mass Spectrometry: Achieving Prominence in Laboratory Medicine

    Energy Technology Data Exchange (ETDEWEB)

    Annesley, Thomas M.; Cooks, Robert G.; Herold, David A.; Hoofnagle, Andrew N.

    2016-01-04

    Each year the journal Clinical Chemistry publishes a January special issue on a topic that is relevant to the laboratory medicine community. In January 2016 the topic is mass spectrometry, and the issue is entitled “Clinical Mass Spectrometry: Achieving Prominence in Laboratory Medicine”. One popular feature in our issues is a Q&A on a topic, clearly in this case mass spectrometry. The journal is assembling a panel of 5-6 experts from various areas of mass spectrometry ranging from instrument manufacturing to practicing clinical chemists. Dick Smith is one of the scientist requested to participate in this special issue Q&A on Mass Spectrometry. The Q&A Transcript is attached

  2. Old World frog and bird vocalizations contain prominent ultrasonic harmonics

    Science.gov (United States)

    Narins, Peter M.; Feng, Albert S.; Lin, Wenyu; Schnitzler, Hans-Ulrich; Denzinger, Annette; Suthers, Roderick A.; Xu, Chunhe

    2004-02-01

    Several groups of mammals such as bats, dolphins and whales are known to produce ultrasonic signals which are used for navigation and hunting by means of echolocation, as well as for communication. In contrast, frogs and birds produce sounds during night- and day-time hours that are audible to humans; their sounds are so pervasive that together with those of insects, they are considered the primary sounds of nature. Here we show that an Old World frog (Amolops tormotus) and an oscine songbird (Abroscopus albogularis) living near noisy streams reliably produce acoustic signals that contain prominent ultrasonic harmonics. Our findings provide the first evidence that anurans and passerines are capable of generating tonal ultrasonic call components and should stimulate the quest for additional ultrasonic species.

  3. Three-Dimensional Morphology of a Coronal Prominence Cavity

    Science.gov (United States)

    Gibson, S. E.; Kucera, T. A.; Rastawicki, D.; Dove, J.; deToma, G.; Hao, J.; Hill, S.; Hudson, H. S.; Marque, C.; McIntosh, P. S.; hide

    2010-01-01

    We present a three-dimensional density model of coronal prominence cavities, and a morphological fit that has been tightly constrained by a uniquely well-observed cavity. Observations were obtained as part of an International Heliophysical Year campaign by instruments from a variety of space- and ground-based observatories, spanning wavelengths from radio to soft-X-ray to integrated white light. From these data it is clear that the prominence cavity is the limb manifestation of a longitudinally-extended polar-crown filament channel, and that the cavity is a region of low density relative to the surrounding corona. As a first step towards quantifying density and temperature from campaign spectroscopic data, we establish the three-dimensional morphology of the cavity. This is critical for taking line-of-sight projection effects into account, since cavities are not localized in the plane of the sky and the corona is optically thin. We have augmented a global coronal streamer model to include a tunnel-like cavity with elliptical cross-section and a Gaussian variation of height along the tunnel length. We have developed a semi-automated routine that fits ellipses to cross-sections of the cavity as it rotates past the solar limb, and have applied it to Extreme Ultraviolet Imager (EUVI) observations from the two Solar Terrestrial Relations Observatory (STEREO) spacecraft. This defines the morphological parameters of our model, from which we reproduce forward-modeled cavity observables. We find that cavity morphology and orientation, in combination with the viewpoints of the observing spacecraft, explains the observed variation in cavity visibility for the east vs. west limbs

  4. Hypercholesterolemia reduces collateral artery growth more dominantly than hyperglycemia or insulin resistance in mice

    NARCIS (Netherlands)

    Weel, V. van; Vries, M. de; Voshol, P.J.; Verloop, R.E.; Eilers, P.H.C.; Hinsbergh, V.W.M. van; Bockel, J.H. van; Quax, P.H.A.

    2006-01-01

    OBJECTIVE - Collateral artery development (arteriogenesis), a vital compensatory mechanism in patients with arterial obstructive disease, may be deregulated by vascular risk factors, eg, diabetes or hypercholesterolemia. Here, we compared the effects of either disturbed glucose metabolism or

  5. Evaluation of computed tomography on diagnosis of portosystemic collaterals in portal hypertension

    International Nuclear Information System (INIS)

    Ohe, Takashi; Kuronuma, Yukio; Fujiwara, Hiromichi; Ibuki, Yoshikazu; Maehara, Misao; Sugaya, Hitoshi; Harada, Takashi; Iwasaki, Naoya; Hyodo, Haruo

    1987-01-01

    We analyzed the diagnostic capability of CT to demonstrate the eight types of portosystemic collaterals in patient with portal hypertension. A total of 62 patients with portal hypertension underwent both CT and conventional angiography. All of these eight types of collaterals, such as esophageal varices, paraesophageal varices, coronary and short gastric pathway, dilated vein in splenic hilus, splenorenal and splenoretroperitoneal pathway, paraumbilical pathway and small veins on liver surface, caput medusa, azygos system, were demonstrated on CT better than angiography, except coronary and short gastric pathyway. And we also made comparative study of CT with per-rectal portal scintigraphy in 9 patients who underwent both studies. In 7 of these 9 patients, portosystemic collaterals were recognized on scintigram less than CT. In conclusion, CT provides much qualified images than conventional angiography or per-rectal portal scintigraphy in evaluating portosystemic collaterals. (author)

  6. Evaluation of computed tomography on diagnosis of portosystemic collaterals in portal hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Ohe, T; Kuronuma, Y; Fujiwara, H; Ibuki, Y; Maehara, M; Sugaya, H; Harada, T; Iwasaki, N; Hyodo, H

    1987-04-01

    We analyzed the diagnostic capability of CT to demonstrate the eight types of portosystemic collaterals in patient with portal hypertension. A total of 62 patients with portal hypertension underwent both CT and conventional angiography. All of these eight types of collaterals, such as esophageal varices, paraesophageal varices, coronary and short gastric pathway, dilated vein in splenic hilus, splenorenal and splenoretroperitoneal pathway, paraumbilical pathway and small veins on liver surface, caput medusa, azygos system, were demonstrated on CT better than angiography, except coronary and short gastric pathyway. And we also made comparative study of CT with per-rectal portal scintigraphy in 9 patients who underwent both studies. In 7 of these 9 patients, portosystemic collaterals were recognized on scintigram less than CT. In conclusion, CT provides much qualified images than conventional angiography or per-rectal portal scintigraphy in evaluating portosystemic collaterals.

  7. Influence of oxidative stress on the development of collateral circulation in total coronary occlusions.

    Science.gov (United States)

    Demirbag, Recep; Gur, Mustafa; Yilmaz, Remzi; Kunt, Alper Sami; Erel, Ozcan; Andac, M Halit

    2007-03-02

    The purpose of this study was to investigate whether the levels of total antioxidant capacity (TAC), total peroxide and oxidative stress index (OSI) are associated with the development of collaterals in total coronary occlusions. Our study group contained 176 consecutive men patients with single-vessel TCO, 94 of whom had poorly developed coronary collateral, while 82 had well-developed coronary collateral. TAC and total peroxide concentration were measured of plasma. The ratio of TAC to total peroxide was accepted as an indicator of oxidative stress. The values of total peroxide and OSI in the Group I were significantly lower than that in Group II (ptotal peroxide and OSI levels (ptotal peroxide and OSI were independent predictors of collaterals score (p=0.006 and ptotal coronary occlusion patients.

  8. Aspirin, but not clopidogrel, reduces collateral conductance in a rabbit model of femoral artery occlusion

    NARCIS (Netherlands)

    Hoefer, Imo E.; Grundmann, Sebastian; Schirmer, Stephan; van Royen, Niels; Meder, Benjamin; Bode, Christoph; Piek, Jan J.; Buschmann, Ivo R.

    2005-01-01

    OBJECTIVES The objective of this study was to test the potential of aspirin and clopidogrel to influence collateral artery growth (arteriogenesis). BACKGROUND Aspirin and clopidogrel are antiplatelet agents commonly used in the treatment of ischemic cardiovascular disease. Both inhibit platelet

  9. 76 FR 31518 - Public Roundtable on the Protection of Cleared Swaps Customer Collateral

    Science.gov (United States)

    2011-06-01

    ... on any other topics related to customer collateral protection in the context of the Act, may do so... comments must be in English or be accompanied by an English translation. All submissions provided to the...

  10. 45 CFR 1336.67 - Security and collateral: Responsibilities of the Loan Administrator.

    Science.gov (United States)

    2010-10-01

    ... inventory or proceeds of inventory sales as well as marketable securities and cash collateral accounts. (1... security at any time during the term of the loan if after review and monitoring an assessment indicates the...

  11. Collateral circulation alters downstream hemodynamic stress caused by intracranial atherosclerotic stenosis.

    Science.gov (United States)

    Liu, Xin; Dornbos, David; Pu, Yuehua; Leng, Xinyi; Song, Ligang; Jia, Baixue; Pan, Yuesong; Wang, David; Miao, Zhongrong; Wang, Yilong; Liu, Liping; Wang, Yongjun

    2017-06-01

    Fractional flow reserve (FFR) accurately predicts the degree of stenosis and is now widely used to identify clinically significant severe coronary artery lesions. In the current study, we utilized a similar indicator, fractional flow (FF), to determine the hemodynamic impact of symptomatic intracranial atherosclerotic stenosis (ICAS) and to assess the correlation of FF with the severity of stenosis and collateral circulation. Patients with symptomatic ICAS (70-99% stenosis) confirmed on digital subtraction angiography (DSA) were consecutively recruited. FF was obtained during DSA examination with the use of pressure sensors and was measured as a ratio, comparing measurements distal to an ICAS lesion (Pd) and within the aorta (Pa). The degree of leptomeningeal collateralization was graded from zero (absent) to four (complete compensatory). The correlation between FF, anatomical stenosis, and collateral status was then analyzed. Twenty-five patients with a mean age of 55.6 years were analyzed. The median percentage of stenosis and median FF were 82.3 and 0.68%, respectively. Eleven patients were found to have poor collateralization (grade 0-2), and fourteen patients were identified with good collateral circulation (grade 3-4). Overall, the hemodynamic impact of an atherosclerotic lesions worsened (decreased FF) as the percentage of stenosis increased, although this did not reach statistical significance (r = -0.398, p = 0.06). However, the status of collateralization significantly altered this correlation, worsening the hemodynamic impact in patients with poor collateral circulation (r = -0.677, p = 0.032). There was no difference in patients with good collateral circulation (r = -0.279, p = 0.356). An anatomically severe (70-99%) symptomatic ICAS lesion may generate significant hemodynamic stress downstream as assessed by the indicator FF, particularly in patients with poor collateral circulation. Further, good collateralization may mitigate this

  12. An isolated left subclavian artery supplied by a collateral artery from the abdominal aorta

    International Nuclear Information System (INIS)

    Ming, Zhu; Qian, Wang

    2009-01-01

    An isolated left subclavian artery is a rare anomaly. We report a 9-month-old boy with an isolated left subclavian artery associated with tetralogy of Fallot and the right aortic arch. MRI and angiography show that the blood supply through the left subclavian artery was maintained by a large tortuous collateral artery from the abdominal aorta. This type of collateral artery structure is unique. (orig.)

  13. An isolated left subclavian artery supplied by a collateral artery from the abdominal aorta

    Energy Technology Data Exchange (ETDEWEB)

    Ming, Zhu; Qian, Wang [Shanghai Jiaotong University School of Medicine, Department of Radiology, Shanghai Children' s Medical Center, Shanghai (China)

    2009-08-15

    An isolated left subclavian artery is a rare anomaly. We report a 9-month-old boy with an isolated left subclavian artery associated with tetralogy of Fallot and the right aortic arch. MRI and angiography show that the blood supply through the left subclavian artery was maintained by a large tortuous collateral artery from the abdominal aorta. This type of collateral artery structure is unique. (orig.)

  14. Collateral status affects the onset-to-reperfusion time window for good outcome.

    Science.gov (United States)

    Kim, Byung Moon; Baek, Jang-Hyun; Heo, Ji Hoe; Nam, Hyo Suk; Kim, Young Dae; Yoo, Joonsang; Kim, Dong Joon; Jeon, Pyoung; Baik, Seung Kug; Suh, Sang Hyun; Lee, Kyung Yol; Kwak, Hyo Sung; Roh, Hong Gee; Lee, Young-Jun; Kim, Sang Heum; Ryu, Chang-Woo; Ihn, Yon-Kwon; Kim, Byungjoon; Jeon, Hong Jun; Kim, Jin Woo; Byun, Jun Soo; Suh, Sangil; Park, Jeong Jin; Lee, Woong Jae; Roh, Jieun; Shin, Byoung-Soo; Bang, Oh Young

    2018-03-08

    To characterise the time window in which endovascular thrombectomy (EVT) is associated with good outcome, and to test the differential relationship between functional outcome and onset-to-reperfusion time (ORT), depending on collateral status. This was a retrospective analysis of clinical and imaging data of 554 consecutive patients, who had recanalisation success by EVT for anterior circulation large artery occlusion, from the prospectively maintained registries of 16 comprehensive stroke centres between September 2010 and December 2015. The patients were dichotomised into good and poor collateral groups, based on CT angiography. We tested whether the likelihood of good outcome (modified Rankin Scale, 0-2) by ORT was different between two groups. ORT was 298 min±113 min (range, 81-665 min), and 84.5% of patients had good collaterals. Age, diabetes mellitus, previous infarction, National Institutes of Health Stroke Scale, good collaterals (OR 40.766; 95% CI 10.668 to 155.78; pcollateral group (OR 0.305 for every 30 min; 95% CI 0.113 to 0.822) than in good collateral group (OR 0.926 for every 30 min; 95% CI 0.875 to 0.980). Earlier successful recanalisation was strongly associated with good outcome in poor collateral group; however, this association was weak during the tested time window in good collateral group. This suggests that the ORT window for good outcome can be adjusted according to collateral status. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  15. Conservative Management of an Epicardial Collateral Perforation During Retrograde Chronic Total Occlusion Percutaneous Coronary Intervention.

    Science.gov (United States)

    Ngo, Christian; Christopoulos, George; Brilakis, Emmanouil S

    2016-01-01

    Coronary artery perforation is a highly feared complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) and can lead to pericardial effusion, tamponade, and, rarely, emergent cardiac surgery. Perforation of epicardial collaterals during retrograde CTO-PCI may be particularly challenging to treat, as embolization from both sides of the perforation may be required to control the bleeding. However, conservative measures can occasionally be effective. We present a case of epicardial collateral vessel perforation that was managed conservatively with anticoagulation reversal.

  16. COLLATERAL'S IMPORTANCE IN SMES FINANCING: WHAT IS THE BANKS' RESPONSE? SOME EVIDENCE FOR ROMANIA

    OpenAIRE

    Badulescu Daniel; Petria Nicolae

    2011-01-01

    Searching for funding, SMEs' managers face various obstacles arising from information asymmetry, lack of experience, severe market conditions, and insufficient or unsatisfactory collaterals for banks (OECD 2006; Badulescu and Badulescu 2010; OECD 2000 and 2004; Lin and Sun 2006; Toivanen and Cresy, 2000). The collateral issue is extensively discussed in literature - preventing moral hazard, the alignment the interests (Stiglitz and Weiss 1981:393-410; Chan and Thakor 1987:345-363; Jiménez and...

  17. Assessment of myocardial collateral circulation by intracoronary injection of radioactive microspheres and selective coronary angiography

    International Nuclear Information System (INIS)

    Uhde, W.

    1986-01-01

    In 46 patients selective coronary angiography was performed followed by selective coronary perfusion scintigraphy and a comparative assessment was made of the contralateral coronary collateral circulation. Intracoronary injection of radioactively marked imcrospheres resulted in the detection of microcirculatory processes and made it possible to evaluate the relative efficiency of coronary collaterals. This in turn meant a low-risk supplement and extension of the findings of coronary angiography. This holds particularly true for the area of the left ventricular myocardium. (author)

  18. Stimulation of collateral artery growth: travelling further down the road to clinical application

    OpenAIRE

    Schirmer, S.H.; van Nooijen, F.C.; Piek, J.J.; van Royen, N.

    2009-01-01

    Collateral artery growth is a potent natural defence mechanism to prevent death and myocardial infarction in occlusive artery disease. Given the high prevalence of arterial obstructive disease, a therapeutic compound stimulating collateral vessel growth could have a major impact on morbidity and mortality world wide. Although experimental studies on the stimulation of arteriogenesis have been promising, not a single drug has been proved to be applicable in clinical practice, either because of...

  19. Differential impact of diabetes mellitus type II and arterial hypertension on collateral artery growth and concomitant macrophage accumulation.

    Science.gov (United States)

    Ito, Wulf D; Lund, Natalie; Sager, Hendrik; Becker, Wiebke; Wenzel, Ulrich

    2015-01-01

    Diabetes mellitus type II and arterial hypertension are major risk factors for peripheral arterial disease and have been considered to reduce collateral growth (arteriogenesis). Collateral growth proceeds through different stages. Vascular proliferation and macrophage accumulation are hallmarks of early collateral growth. We here compare the impact of arterial hypertension and diabetes mellitus type II on collateral proliferation (Brdu incorporation) and macrophage accumulation (ED 2 staining) as well as collateral vessel function (collateral conductance) in a rat model of peripheral vascular disease (femoral artery occlusion), diabetes mellitus type II (Zucker fatty diabetic rats and Zucker lean rat controls) and arterial hypertension (induced via clip placement around the right renal arteriy). We furthermore tested the impact of monocyte chemoattractant protein-1 (MCP‑1) on collateral proliferation and macrophage accumulation in these models Diabetic animals showed reduced vascular proliferation and macrophage accumulation, which however did not translate into a change of collateral conductance. Hypertensive animals on the contrary had reduced collateral conductances without altered macrophage accumulation and only a marginal reduction in collateral proliferation. Infusion of MCP‑1 only enhanced vascular proliferation in diabetic animals. These findings illustrate that impaired monocyte/macrophage recruitment is responsible for reduced collateral growth under diabetic conditions but not in arterial hypertension suggesting that diabetes mellitus in particular affects early stages of collateral growth whereas hypertension has its impact on later remodeling stages. Successful pro-arteriogenic treatment strategies in a patient population that presents with diabetes mellitus and arterial hypertension need to address different stages of collateral growth and thus different molecular and cellular targets simultaneously.

  20. Prediction of infarction and reperfusion in stroke by flow- and volume-weighted collateral signal in MR angiography.

    Science.gov (United States)

    Ernst, M; Forkert, N D; Brehmer, L; Thomalla, G; Siemonsen, S; Fiehler, J; Kemmling, A

    2015-02-01

    In proximal anterior circulation occlusive strokes, collateral flow is essential for good outcome. Collateralized vessel intensity in TOF- and contrast-enhanced MRA is variable due to different acquisition methods. Our purpose was to quantify collateral supply by using flow-weighted signal in TOF-MRA and blood volume-weighted signal in contrast-enhanced MRA to determine each predictive contribution to tissue infarction and reperfusion. Consecutively (2009-2013), 44 stroke patients with acute proximal anterior circulation occlusion met the inclusion criteria with TOF- and contrast-enhanced MRA and penumbral imaging. Collateralized vessels in the ischemic hemisphere were assessed by TOF- and contrast-enhanced MRA using 2 methods: 1) visual 3-point collateral scoring, and 2) collateral signal quantification by an arterial atlas-based collateral index. Collateral measures were tested by receiver operating characteristic curve and logistic regression against 2 imaging end points of tissue-outcome: final infarct volume and percentage of penumbra saved. Visual collateral scores on contrast-enhanced MRA but not TOF were significantly higher in patients with good outcome. Visual collateral scoring on contrast-enhanced MRA was the best rater-based discriminator for final infarct volume 50% (area under the curve, 0.67; P = .04). Atlas-based collateral index of contrast-enhanced MRA was the overall best independent discriminator for final infarct volume of collateral index combining the signal of TOF- and contrast-enhanced MRA was the overall best discriminator for effective reperfusion (percentage of penumbra saved >50%; area under the curve, 0.89; P collateral assessment, TOF- and contrast-enhanced MRA both contain predictive signal information for penumbral reperfusion. This could improve risk stratification in further studies. © 2015 by American Journal of Neuroradiology.

  1. Acute development of collateral circulation and therapeutic prospects in ischemic stroke

    Directory of Open Access Journals (Sweden)

    Eri Iwasawa

    2016-01-01

    Full Text Available In acute ischemic stroke, collateral circulation plays an important role in maintaining blood flow to the tissue that is at risk of progressing into ischemia, and in increasing the successful recanalization rate without hemorrhagic transformation. We have reported that well-developed collateral circulation is associated with smaller infarct volume and better long-term neurological outcome, and it disappears promptly once the effective recanalization is achieved. Contrary to the belief that collateral vessels develop over time in chronic stenotic condition, there exists a phenomenon that collateral circulation develops immediately in acute stenosis or occlusion of the arteries and it seems to be triggered by fluid shear stress, which occurs between the territories of stenotic/occluded arteries and those fed by surrounding intact arteries. We believe that this acute development of collateral circulation is a target of novel therapeutics in ischemic stroke and refer our recent attempt in enhancing collateral circulation by modulating sphingosine-1-phosphate receptor 1, which is a known shear-stress mechanosensing protein.

  2. Why is coronary collateral growth impaired in type II diabetes and the metabolic syndrome?

    Science.gov (United States)

    Rocic, Petra

    2012-01-01

    Type II diabetes and the metabolic syndrome are strong predictors of severity of occlusive coronary disease and poorer outcomes of coronary revascularization therapies. Coronary collateral growth can provide an alternative or accessory pathway of revascularization. However, collateral growth is impaired in type II diabetes and the metabolic syndrome. Although many factors necessary for collateral growth are known and many interventions have shown promising results in animal studies, not a single attempt to induce coronary collateral growth in human clinical trials has led to satisfactory results. Accordingly, the first part of this review outlines the known deleterious effects of diabetes and the metabolic syndrome on factors necessary for collateral growth, including pro-angiogenic growth factors, endothelial function, the redox state of the coronary circulation, intracellular signaling, leukocytes and bone marrow-derived progenitors cells. The second section highlights the gaps in our current knowledge of how these factors interact with the radically altered environment of the coronary circulation in diabetes and the metabolic syndrome. The interplay between these pathologies and inadequately explored areas related to the temporal regulation of collateral remodeling and the roles of the extracellular matrix, vascular cell phenotype and pro-inflammatory cytokines are emphasized with implications to development of efficient therapies. PMID:22342811

  3. Retrospective analysis of intravertebral collateral enhancement in patients with central venous obstruction

    International Nuclear Information System (INIS)

    Simeone, F.J.; Chang, Connie Y.; Huang, Ambrose J.; Kattapuram, Susan V.; Bredella, Miriam A.; Torriani, Martin; Bennett, Debbie L.

    2016-01-01

    To compare prevalence and patterns of intravertebral collateral enhancement in patients with and without central venous obstruction (CVO). Chest CTs performed between 1/1/2000 and 12/15/2012 with reports containing terms indicating CVO were identified. All contrast enhanced CTs were examined for the presence of CVO and collateral venous pathways. If intravertebral collateral enhancement was present, the pattern was recorded as nodular, linear, or both. In 209 suspected cases of CVO, 53 (25 %) were confirmed with obstruction and 156 (75 %) were without obstruction. In patients with CVO, 47 % (25/53) demonstrated collateral venous flow through an intravertebral marrow pathway compared to 5 % (8/156) of patients without CVO (P < 0.0001). The most common level of enhancement was the upper thoracic spine, involving only the vertebral body. Nodular, linear, and combined nodular-linear enhancement patterns were seen with similar frequency. Nodular intravertebral collateral enhancement was mistaken for sclerotic metastases in 33 % (3/9) of cases. Intravertebral collateral enhancement was seen in almost half the patients with CVO and when nodular enhancement is present, it is important to differentiate between metastatic lesions and enhancement related to CVO. (orig.)

  4. Acute development of collateral circulation and therapeutic prospects in ischemic stroke.

    Science.gov (United States)

    Iwasawa, Eri; Ichijo, Masahiko; Ishibashi, Satoru; Yokota, Takanori

    2016-03-01

    In acute ischemic stroke, collateral circulation plays an important role in maintaining blood flow to the tissue that is at risk of progressing into ischemia, and in increasing the successful recanalization rate without hemorrhagic transformation. We have reported that well-developed collateral circulation is associated with smaller infarct volume and better long-term neurological outcome, and it disappears promptly once the effective recanalization is achieved. Contrary to the belief that collateral vessels develop over time in chronic stenotic condition, there exists a phenomenon that collateral circulation develops immediately in acute stenosis or occlusion of the arteries and it seems to be triggered by fluid shear stress, which occurs between the territories of stenotic/occluded arteries and those fed by surrounding intact arteries. We believe that this acute development of collateral circulation is a target of novel therapeutics in ischemic stroke and refer our recent attempt in enhancing collateral circulation by modulating sphingosine-1-phosphate receptor 1, which is a known shear-stress mechanosensing protein.

  5. Blood pool SPECT for visualization of portosystemic collaterals in portal hypertension

    International Nuclear Information System (INIS)

    Kroiss, A.; Auinger, C.

    1990-01-01

    In 46 patients, 26 male and 20 female, age from 32 to 71 years (mean 47,4 ± 11 years) a bloodpool-scintigraphy (BSP) with SPECT (single photon emission computed tomography) was performed. The in-vivo labelling of the erythrocytes with pyrophosphate and Tc99m was performed in the usual way. The SPECT investigations were performed with a digital Anger-Camera (Elscint; Apex 401). In 14 patients without collaterals BPS was performed to compare the method with patients with liver diseases and collaterals. 29 patients with liver cirrhosis and portal hypertension were investigated with the BSP and additionaly a scintisplenoportography (SSP) was performed. In patients with only cephalad collaterals all the results were concordant. In just 1 patient with cephalad and caudad collaterals we found a discordant result. In 8 patients we performed BSP, SSP and a katheterangiography (KA). Taking the KA as the 'golden standard' we found a concordant result with the 3 methods in all patients with cephalad collaterals. In patients with cephalad and caudad collaterals we once found a discordant result with the SSP and twice with the BSP. In 2 patients the patency of surgical shunts were proved. 2 patients after sclerosis of the oesophageal varices have been proved by BPS and SSP and both patients showed good therapeutical results. (Authors)

  6. Retrospective analysis of intravertebral collateral enhancement in patients with central venous obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Simeone, F.J.; Chang, Connie Y.; Huang, Ambrose J.; Kattapuram, Susan V.; Bredella, Miriam A.; Torriani, Martin [Massachusetts General Hospital and Harvard Medical School, Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Boston, MA (United States); Bennett, Debbie L. [Saint Louis University School of Medicine, Department of Radiology, Saint Louis, MO (United States)

    2016-02-15

    To compare prevalence and patterns of intravertebral collateral enhancement in patients with and without central venous obstruction (CVO). Chest CTs performed between 1/1/2000 and 12/15/2012 with reports containing terms indicating CVO were identified. All contrast enhanced CTs were examined for the presence of CVO and collateral venous pathways. If intravertebral collateral enhancement was present, the pattern was recorded as nodular, linear, or both. In 209 suspected cases of CVO, 53 (25 %) were confirmed with obstruction and 156 (75 %) were without obstruction. In patients with CVO, 47 % (25/53) demonstrated collateral venous flow through an intravertebral marrow pathway compared to 5 % (8/156) of patients without CVO (P < 0.0001). The most common level of enhancement was the upper thoracic spine, involving only the vertebral body. Nodular, linear, and combined nodular-linear enhancement patterns were seen with similar frequency. Nodular intravertebral collateral enhancement was mistaken for sclerotic metastases in 33 % (3/9) of cases. Intravertebral collateral enhancement was seen in almost half the patients with CVO and when nodular enhancement is present, it is important to differentiate between metastatic lesions and enhancement related to CVO. (orig.)

  7. Acute development of collateral circulation and therapeutic prospects in ischemic stroke

    Institute of Scientific and Technical Information of China (English)

    Eri Iwasawa; Masahiko Ichijo; Satoru Ishibashi; Takanori Yokota

    2016-01-01

    In acute ischemic stroke, collateral circulation plays an important role in maintaining blood lfow to the tissue that is at risk of progressing into ischemia, and in increasing the successful recanalization rate with-out hemorrhagic transformation. We have reported that well-developed collateral circulation is associated with smaller infarct volume and better long-term neurological outcome, and it disappears promptly once the effective recanalization is achieved. Contrary to the belief that collateral vessels develop over time in chronic stenotic condition, there exists a phenomenon that collateral circulation develops immediately in acute stenosis or occlusion of the arteries and it seems to be triggered by lfuid shear stress, which occurs be-tween the territories of stenotic/occluded arteries and those fed by surrounding intact arteries. We believe that this acute development of collateral circulation is a target of novel therapeutics in ischemic stroke and refer our recent attempt in enhancing collateral circulation by modulating sphingosine-1-phosphate recep-tor 1, which is a known shear-stress mechanosensing protein.

  8. Insights into coronary collateral formation from a novel porcine semiacute infarction model.

    Science.gov (United States)

    Krackhardt, Florian; Harnoss, Jonathan M; Waliszewski, Matthias W; Ritter, Zully; Granzow, Susanne; Felsenberg, Dieter; Neumann, Konrad; Lerman, Lilian O; Hillmeister, Philipp; Gebker, Rolf; Paetsch, Ingo; Riediger, Fabian; Bramlage, Peter; Buschmann, Ivo R

    2018-03-01

    For patients with severe ischemic heart disease, complete revascularization by a percutaneous coronary intervention or coronary artery bypass grafting is often not achieved and may still cause residual angina. In case of progressive coronary artery occlusions, therapeutic arteriogenesis constitutes a promising strategy for increasing blood supply to the ischemic myocardium. Whether the formation of collaterals in the hypofused myocardium is angiogenetic in nature or based on preformed coronary artery anastomoses remains debatable. The objectives of this research were (i) the development of an appropriate research methodology to study a humanoid animal semiacute infarction model with low mortality and (ii) to answer the question of whether collateral revascularization follows a pre-existing 'blueprint'. A porcine model was chosen in which a step-wise vessel occlusion was performed by implantation of a copper stent into the distal left anterior descending artery. Vessel occlusion and collateral development were confirmed in vivo every 14 days up to day 56 by repeated coronary angiography and myocardial perfusion measurement using cardiac MRI. After the completion of the in-vivo imaging studies, animals were euthanized and collateral growth was evaluated using microcomputer tomography. Our porcine model of semiacute noninvasive coronary artery occlusion confirmed the existence of preformed coronary anastomoses and the proliferation of functional vessels in hypoperfused myocardium. Repetitive intra-animal MRIs showed the functional impact of these growing collaterals. The confirmation of preformed coronary anastomoses during the process of collateralization (natural bypasses) offers a preclinical avenue to carry out arteriogenetic pharmaceutical research in patients with ischemic heart disease.

  9. Clinico-Epidemiological Comparison of Delusion-Prominent and Hallucination-Prominent Clinical Subgroups of Paranoid Schizophrenia.

    Science.gov (United States)

    Kreinin, Anatoly; Krishtul, Vladimir; Kirsh, Zvi; Menuchin, Michael

    2015-01-01

    Though hallucinations and delusions are prominent basic impairments in schizophrenia, reports of the relationship between hallucinatory and delusional symptoms among schizophrenia patients are scant. To examine the epidemiological and clinical differences between mainly hallucinatory and mainly delusional subgroups of paranoid schizophrenia patients. One hundred schizophrenia patients, paranoid type, were recruited. In a cross-sectional study, participants were divided into Mainly Hallucinatory (H) and Mainly Delusional (D) subgroups. Demographic variables were compared and clinical characteristics were evaluated using the Scale for the Assessment of Positive Symptoms, the Scale for the Assessment of Negative Symptoms, and the Clinical Global Impression Scale. The Quality-of-Life Enjoyment and Satisfaction Questionnaire-18 was used to assess quality of life. Clinically, the H group was more heterogeneous as expressed by the broader range of scores that described the clinical picture of patients in that subgroup (in 43 of 78 variables, 55.13%) and similar ranges of scores (31 of 78 variables, 39.74%) for patients in the D group. Duration of hospitalization was significantly longer in group H than in group D (p=0.047). There was no statistically significant difference between the H and D subgroups in demographic characteristics. There are distinct epidemiological and clinical differences between the H and D subgroups, with more severe positive and negative symptoms and greater functional impairment in the H group. Paranoid schizophrenia patients with prominent hallucinations have poorer prognosis and need intensive therapeutic rehabilitation beginning with onset-of-illness. Further genetic studies and comparisons of fMRI and/or PET findings are warranted to investigate additional distinctive characteristics of these subgroups.

  10. A case of unusual collateral circulation from internal carotid occlusion

    International Nuclear Information System (INIS)

    Jang, Il Jung; Choi, Byung So

    1972-01-01

    A 23 year old Korean boy was admitted to Dept. of Neurosurgery. Capital Army Hospital on Feb. 2, 1971 because of recurrent transient focal seizure and more weakness in the left extremities. During hospitalization, he recovered from focal seizure and motor weakness in the left extremities without specific therapy. Right carotid angiograms were performed. Right carotid angiograms show right internal carotic occlusion at the level of distal siphon of extradural level with good filling of ophthalmic artery of right. Extensive small vascular network developed intracranial region of right hemisphere. There are appearance to be two major anastomotic communication. 1. Via at the base of the brain. 2. Via the rete mirabile with external carotid artery. These angiographic finding were similar to that of the so-called 'cerebral rete mirabile' which was described in many literature. Etiology of cerebral rete mirabile is divided as to whether these represent true congenital vascular malformations or whether the 'rete mirabile' develops as a collateral because of a primary stenosis in the internal carotid arteries. Evidence for either theory is still inconclusive

  11. Radiologic comparison of erosive polyarthritis with prominent interphalangeal involvement

    International Nuclear Information System (INIS)

    Gold, R.H.; Bassett, L.W.; Theros, E.G.

    1982-01-01

    Psoriatic arthritis, Reiter's disease, and multicentric reticulohistiocytosis may manifest prominent interphalangeal joint and cutaneous involvement. All three disorders may also affect the sacroiliac joints and spine. Despite these similarities, there are basic radiologic differences enabling distinction between the three disorders. Erosive osteoarthritis must also be considered in the differential diagnosis of interphalangeal erosive arthritis. Psoriatic erosions are characteristically ill defined, often bilaterally asymmetrical, usually unaccompanied by significant osteoporosis, and frequently associated with florid proliferation of subperiosteal new bone. An unilateral polyarticular pattern, which often occurs in a single ray, is the most prevalent of several patterns of involvement. Reiter's disease exhibits many clinical and radiologic similarities to psoriatic arthritis, but in the former there tends to be selective involvement of the joints of the lower limbs and particularly the feet, with relative sparing of the hands and wrists, while in the latter the joints of the upper and lower limbs tend to be involved to an equal extent. Multicentric reticulohistiocytosis (MR). Lesions predominate in skin and synovium and result in sharply circumscribed, rapidly progressive, strikingly bilaterally symmetrical erosions spreading from joint margins to articular surfaces. Most or all of the diarthrodial joints may be affected, but interphalangeal joint predominance and early and severe atlanto-axial involvement are characteristic. Erosive osteoarthritis is characterized by interphalangeal subchondral erosions, accompanying periosteal new bone that is more subtle than that of psoriatic arthritis, and interphalangeal bony ankylosis that occurs with the same frequency as that of psoriatic arthritis. (orig.)

  12. Quantifying the cepstral peak prominence, a measure of dysphonia.

    Science.gov (United States)

    Heman-Ackah, Yolanda D; Sataloff, Robert T; Laureyns, Griet; Lurie, Deborah; Michael, Deirdre D; Heuer, Reinhardt; Rubin, Adam; Eller, Robert; Chandran, Swapna; Abaza, Mona; Lyons, Karen; Divi, Venu; Lott, Joanna; Johnson, Jennifer; Hillenbrand, James

    2014-11-01

    The purpose of this study is to establish normative values for the smoothed cepstral peak prominence (CPPS) and its sensitivity and specificity as a measure of dysphonia. Prospective cohort study. Voice samples of running speech were obtained from 835 patients and 50 volunteers. Eight laryngologists and four speech-language pathologists performed perceptual ratings of the voice samples on the degree of dysphonia/normality using an analog scale. The mean of their perceptual ratings was used as the gold standard for the detection of the presence or absence of dysphonia. CPPS was measured using the CPPS algorithm of Hillenbrand, and the cut-off value for positivity that has the highest sensitivity and specificity for discriminating between normal and severely dysphonia voices was determined based on ROC-curve analysis. The cut-off value for normal for CPPS was set at 4.0 or higher, which gave a sensitivity of 92.4%, a specificity of 79%, a positive predictive value of 82.5%, and a negative predictive value of 90.8%. The area under the receiver operating characteristic (ROC) curve was 0.937 (P dysphonia, with the normal value of CPPS (Hillenbrand algorithm) of a running speech sample being defined as a value of 4.0 or higher. Copyright © 2014 The Voice Foundation. All rights reserved.

  13. Porcine CD38 exhibits prominent secondary NAD(+) cyclase activity.

    Science.gov (United States)

    Ting, Kai Yiu; Leung, Christina F P; Graeff, Richard M; Lee, Hon Cheung; Hao, Quan; Kotaka, Masayo

    2016-03-01

    Cyclic ADP-ribose (cADPR) mobilizes intracellular Ca(2+) stores and activates Ca(2+) influx to regulate a wide range of physiological processes. It is one of the products produced from the catalysis of NAD(+) by the multifunctional CD38/ADP-ribosyl cyclase superfamily. After elimination of the nicotinamide ring by the enzyme, the reaction intermediate of NAD(+) can either be hydrolyzed to form linear ADPR or cyclized to form cADPR. We have previously shown that human CD38 exhibits a higher preference towards the hydrolysis of NAD(+) to form linear ADPR while Aplysia ADP-ribosyl cyclase prefers cyclizing NAD(+) to form cADPR. In this study, we characterized the enzymatic properties of porcine CD38 and revealed that it has a prominent secondary NAD(+) cyclase activity producing cADPR. We also determined the X-ray crystallographic structures of porcine CD38 and were able to observe conformational flexibility at the base of the active site of the enzyme which allow the NAD(+) reaction intermediate to adopt conformations resulting in both hydrolysis and cyclization forming linear ADPR and cADPR respectively. © 2016 The Protein Society.

  14. Prominent feature extraction for review analysis: an empirical study

    Science.gov (United States)

    Agarwal, Basant; Mittal, Namita

    2016-05-01

    Sentiment analysis (SA) research has increased tremendously in recent times. SA aims to determine the sentiment orientation of a given text into positive or negative polarity. Motivation for SA research is the need for the industry to know the opinion of the users about their product from online portals, blogs, discussion boards and reviews and so on. Efficient features need to be extracted for machine-learning algorithm for better sentiment classification. In this paper, initially various features are extracted such as unigrams, bi-grams and dependency features from the text. In addition, new bi-tagged features are also extracted that conform to predefined part-of-speech patterns. Furthermore, various composite features are created using these features. Information gain (IG) and minimum redundancy maximum relevancy (mRMR) feature selection methods are used to eliminate the noisy and irrelevant features from the feature vector. Finally, machine-learning algorithms are used for classifying the review document into positive or negative class. Effects of different categories of features are investigated on four standard data-sets, namely, movie review and product (book, DVD and electronics) review data-sets. Experimental results show that composite features created from prominent features of unigram and bi-tagged features perform better than other features for sentiment classification. mRMR is a better feature selection method as compared with IG for sentiment classification. Boolean Multinomial Naïve Bayes) algorithm performs better than support vector machine classifier for SA in terms of accuracy and execution time.

  15. Combined surgical management of mandibular angle prominence and microgenia

    International Nuclear Information System (INIS)

    Portelles Masso, Ayelen Maria; Berger Kohn, Carlos

    2010-01-01

    Chin play a very important role in facial aesthetics. Different deformities of volume and of position may occur at this level and it is the microgenia one of the more frequent. Treatment options include the use of silicone, alloplasty materials and autologous bone graft. Authors report the use of the bone removed from mandibular angle to increase the chin. This is the case of a white female patient aged 18 seen by the Orthognathics Multidisciplinary Staff of 'V. I. Lenin' Hospital due to its uncommon face width. The corresponding physical examination as well as the complementary ones diagnosed a bilateral prominence of mandibular angle associated with a microgenia. Surgery carried out was of remodeling type of both mandibular angles and genioplasty of height increase and a discrete advancement using the bone removed from the gonion. There were satisfactory aesthetic results without evidence of bone reabsorption. We conclude that use of autologous graft of mandibular angle is an effective treatment alternative for correction of microgenia. (author)

  16. The coordination of boundary tones and its interaction with prominence.

    Science.gov (United States)

    Katsika, Argyro; Krivokapić, Jelena; Mooshammer, Christine; Tiede, Mark; Goldstein, Louis

    2014-05-01

    This study investigates the coordination of boundary tones as a function of stress and pitch accent. Boundary tone coordination has not been experimentally investigated previously, and the effect of prominence on this coordination, and whether it is lexical (stress-driven) or phrasal (pitch accent-driven) in nature is unclear. We assess these issues using a variety of syntactic constructions to elicit different boundary tones in an Electromagnetic Articulography (EMA) study of Greek. The results indicate that the onset of boundary tones co-occurs with the articulatory target of the final vowel. This timing is further modified by stress, but not by pitch accent: boundary tones are initiated earlier in words with non-final stress than in words with final stress regardless of accentual status. Visual data inspection reveals that phrase-final words are followed by acoustic pauses during which specific articulatory postures occur. Additional analyses show that these postures reach their achievement point at a stable temporal distance from boundary tone onsets regardless of stress position. Based on these results and parallel findings on boundary lengthening reported elsewhere, a novel approach to prosody is proposed within the context of Articulatory Phonology: rather than seeing prosodic (lexical and phrasal) events as independent entities, a set of coordination relations between them is suggested. The implications of this account for prosodic architecture are discussed.

  17. Prominent Determinants of Consumer-Based Brand Equity

    Directory of Open Access Journals (Sweden)

    Elisa Battistoni

    2013-08-01

    Full Text Available In this paper we investigate the most prominent drivers of brand equity, from a consumerbased point of view. We present a new approach for measuring brand equity, which can be applied regardless of the brand sector and is based on the Analytic Hierarchy Process. This approach has the main advantage of allowing for comparisons to be made between non‐directly measurable elements and also has the advantage of enabling the ranking of intangible criteria, such as consumers’ feelings or purchase intentions. We focus on the fashion industry, since we believe in the higher value of our approach when applied to brands which offer products with less tangible characteristics. Thanks to a case study – which involved about 250 interviewees – we succeed in finding and prioritizing the elements which can have an impact on the brand value. We also provide a global ranking for three apparel brands: Gap, H&M and Zara. The results from our model are consistent with other popular ratings and can be extremely useful for brand managers.

  18. COLLATERAL'S IMPORTANCE IN SMES FINANCING: WHAT IS THE BANKS RESPONSE? SOME EVIDENCE FOR ROMANIA

    Directory of Open Access Journals (Sweden)

    Petria Nicolae

    2011-07-01

    Full Text Available Searching for funding, SMEs managers face various obstacles arising from information asymmetry, lack of experience, severe market conditions, and insufficient or unsatisfactory collaterals for banks (OECD 2006; Badulescu and Badulescu 2010; OECD 2000 and 2004; Lin and Sun 2006; Toivanen and Cresy, 2000. The collateral issue is extensively discussed in literature preventing moral hazard, the alignment the interests (Stiglitz and Weiss 1981:393-410; Chan and Thakor 1987:345-363; Jimenez and Saurina 2004, a means to discipline the borrowers behaviour (ex post given the existence of a credible threat (Aghion and Bolton 1992:473-494, or even banking behaviour on the market (Manove et al. 2001:726-744, Argentiero 2009. In the same time we find that the perception of firms, revealed by National Bank of Romania (NBR 2010 survey data, show that banks still use the collateral as a measure of pressure, in special in crisis times. For an important part of managers, the bank increased the level of required collateral for existing, renewing or new credits, asking for new covenants, revealing a paradox of crisis time: while the bank loans remained the favourite method of external financing needs of business, the banks often reduce their availability. Although the bank loan remains the favorite mean to support the growth ambitions, the higher level of collateral or lending costs are seen as principal obstacles by the majority of manager in EU. According to NBR survey, the influence of risk factors related to collateral had a climax at the end of 2008 and 2009, when the banks have tightened the requirement for loan guarantee. Using National Bank of Romania (NBR 2010 survey data, we show that the banks still use the collateral as a measure of pressure, in special in crisis times. For an important part of managers, the bank increased the level of required collateral for existing, renewing or new credits, asking for new covenants, revealing a paradox of crisis time

  19. Impaired Leptomeningeal Collateral Flow Contributes to the Poor Outcome following Experimental Stroke in the Type 2 Diabetic Mice

    Science.gov (United States)

    Akamatsu, Yosuke; Nishijima, Yasuo; Lee, Chih Cheng; Yang, Shih Yen; Shi, Lei; An, Lin; Wang, Ruikang K.; Tominaga, Teiji

    2015-01-01

    Collateral status is an independent predictor of stroke outcome. However, the spatiotemporal manner in which collateral flow maintains cerebral perfusion during cerebral ischemia is poorly understood. Diabetes exacerbates ischemic brain damage, although the impact of diabetes on collateral dynamics remains to be established. Using Doppler optical coherent tomography, a robust recruitment of leptomeningeal collateral flow was detected immediately after middle cerebral artery (MCA) occlusion in C57BL/6 mice, and it continued to grow over the course of 1 week. In contrast, an impairment of collateral recruitment was evident in the Type 2 diabetic db/db mice, which coincided with a worse stroke outcome compared with their normoglycemic counterpart db/+, despite their equally well-collateralized leptomeningeal anastomoses. Similar to the wild-type mice, both db/+ and db/db mice underwent collateral growth 7 d after MCA stroke, although db/db mice still exhibited significantly reduced retrograde flow into the MCA territory chronically. Acutely induced hyperglycemia in the db/+ mice did not impair collateral flow after stroke, suggesting that the state of hyperglycemia alone was not sufficient to impact collateral flow. Human albumin was efficacious in improving collateral flow and outcome after stroke in the db/db mice, enabling perfusion to proximal MCA territory that was usually not reached by retrograde flow from anterior cerebral artery without treatment. Our results suggest that the impaired collateral status contributes to the exacerbated ischemic injury in mice with Type 2 diabetes, and modulation of collateral flow has beneficial effects on stroke outcome among these subjects. PMID:25740515

  20. Impact of Admission Blood Glucose on Coronary Collateral Flow in Patients with ST-Elevation Myocardial Infarction.

    Science.gov (United States)

    Kurmus, Ozge; Aslan, Turgay; Ekici, Berkay; Baglan Uzunget, Sezen; Karaarslan, Sukru; Tanindi, Asli; Erkan, Aycan Fahri; Akgul Ercan, Ebru; Kervancıoglu, Celal

    2018-01-01

    In patients with acute myocardial infarction, glucose metabolism is altered and acute hyperglycemia on admission is common regardless of diabetes status. The development of coronary collateral is heterogeneous among individuals with coronary artery disease. In this study, we aimed to investigate whether glucose value on admission is associated with collateral flow in ST-elevation myocardial infarction (STEMI) patients. We retrospectively evaluated 190 consecutive patients with a diagnosis of first STEMI within 12 hours of onset of chest pain. Coronary collateral development was graded according to Rentrop classification. Rentrop 0-1 was graded as poor collateral development, and Rentrop 2-3 was graded as good collateral development. Admission glucose was measured and compared between two groups. Mean admission glucose level was 173.0 ± 80.1 mg/dl in study population. Forty-five (23.7%) patients had good collateral development, and 145 (76.3%) patients had poor collateral development. There were no statistically significant differences in demographic characteristics between two groups. Three-vessel disease was more common in patients with good collateral development ( p =0.026). Mean admission glucose level was higher in patients with poor collateral than good collateral (180.6 ± 84.9 mg/dl versus 148.7 ± 56.6 mg/dl, resp., p =0.008). In univariate analysis, higher admission glucose was associated with poor collateral development, but multivariate logistic regression analysis revealed a borderline result (odds ratio 0.994, 95% CI 0.989-1.000, p =0.049). Our results suggest that elevated glucose on admission may have a role in the attenuation of coronary collateral blood flow in acute myocardial infarction. Further studies are needed to validate our results.

  1. Predicting Collateral Status With Magnetic Resonance Perfusion Parameters: Probabilistic Approach With a Tmax-Derived Prediction Model.

    Science.gov (United States)

    Lee, Mi Ji; Son, Jeong Pyo; Kim, Suk Jae; Ryoo, Sookyung; Woo, Sook-Young; Cha, Jihoon; Kim, Gyeong-Moon; Chung, Chin-Sang; Lee, Kwang Ho; Bang, Oh Young

    2015-10-01

    Good collateral flow is an important predictor for favorable responses to recanalization therapy and successful outcomes after acute ischemic stroke. Magnetic resonance perfusion-weighted imaging (MRP) is widely used in patients with stroke. However, it is unclear whether the perfusion parameters and thresholds would predict collateral status. The present study evaluated the relationship between hypoperfusion severity and collateral status to develop a predictive model for good collaterals using MRP parameters. Patients who were eligible for recanalization therapy that underwent both serial diffusion-weighted imaging and serial MRP were enrolled into the study. A collateral flow map derived from MRP source data was generated through automatic postprocessing. Hypoperfusion severity, presented as proportions of every 2-s Tmax strata to the entire hypoperfusion volume (Tmax≥2 s), was compared between patients with good and poor collaterals. Prediction models for good collaterals were developed with each Tmax strata proportion and cerebral blood volumes. Among 66 patients, 53 showed good collaterals based on MRP-based collateral grading. Although no difference was noted in delays within 16 s, more severe Tmax delays (Tmax16-18 s, Tmax18-22 s, Tmax22-24 s, and Tmax>24 s) were associated with poor collaterals. The probability equation model using Tmax strata proportion demonstrated high predictive power in a receiver operating characteristic analysis (area under the curve=0.9303; 95% confidence interval, 0.8682-0.9924). The probability score was negatively correlated with the volume of infarct growth (P=0.030). Collateral status is associated with more severe Tmax delays than previously defined. The present Tmax severity-weighted model can determine good collaterals and subsequent infarct growth. © 2015 American Heart Association, Inc.

  2. Piecewise mass flows within a solar prominence observed by the New Vacuum Solar Telescope

    Science.gov (United States)

    Li, Hongbo; Liu, Yu; Tam, Kuan Vai; Zhao, Mingyu; Zhang, Xuefei

    2018-06-01

    The material of solar prominences is often observed in a state of flowing. These mass flows (MF) are important and useful for us to understand the internal structure and dynamics of prominences. In this paper, we present a high resolution Hα observation of MFs within a quiescent solar prominence. From the observation, we find that the plasma primarily has a circular motion and a downward motion separately in the middle section and legs of the prominence, which creates a piecewise mass flow along the observed prominence. Moreover, the observation also shows a clear displacement of MF's velocity peaks in the middle section of the prominence. All of these provide us with a detailed record of MFs within a solar prominence and show a new approach to detecting the physical properties of prominence.

  3. Embolization for Thoracic Duct Collateral Leakage in High-Output Chylothorax After Thoracic Surgery

    Energy Technology Data Exchange (ETDEWEB)

    Kariya, Shuji, E-mail: kariyas@hirakata.kmu.ac.jp; Nakatani, Miyuki, E-mail: nakatanm@hirakata.kmu.ac.jp; Yoshida, Rie, E-mail: yagir@hirakata.kmu.ac.jp; Ueno, Yutaka, E-mail: uenoyut@hirakata.kmu.ac.jp; Komemushi, Atsushi, E-mail: komemush@takii.kmu.ac.jp; Tanigawa, Noboru, E-mail: tanigano@hirakata.kmu.ac.jp [Kansai Medical University, Department of Radiology (Japan)

    2017-01-15

    PurposeThis study was designed to investigate thoracic duct collateral leakage and the supply route of lymphatic fluid by lymphangiography and transcatheter thoracic ductography and to evaluate the results of embolization for thoracic duct collateral leakage performed to cut off this supply route.MethodsData were retrospectively collected from five patients who underwent embolization for thoracic duct collateral leakage in persistent high-output chylothorax after thoracic surgery. Extravasation of lipiodol at the ruptured thoracic duct collaterals was confirmed in all patients on lymphangiography. Transcatheter thoracic ductography was used to identify extravasation of iodinated contrast agent and to identify communication between the thoracic duct and leakage site. Thoracic duct embolization (TDE) was performed using the percutaneous transabdominal approach to cut off the supply route using N-butyl cyanoacrylate (NBCA) mixed with lipiodol (1:5–1:20).ResultsClinical success (drainage volume ≤10 mL/kg/day within 7 days after TDE) was achieved in all patients. The collateral routes developed as consequence of surgical thoracic duct ligation. In three patients, NBCA-Lipiodol reached the leakage site through direct communication between the thoracic duct and the ruptured lymphatic duct. In the other two patients, direct communication and extravasation was not detected on thoracic ductography, and NBCA-Lipiodol did not reach the leakage site. However, NBCA-Lipiodol did reach the cisterna chyli, lumbar trunks, and some collateral routes via the cisterna chyli or lumbar lymphatics. As a result, leakage was stopped.ConclusionsTDE was effective for the management of leakage of the collaterals in high-output chylothorax after thoracic surgery.

  4. Cognitive assessment of older adults in general practice: the collateral history.

    Science.gov (United States)

    Dyer, Adam H; Foley, Tony; O'Shea, Brendan; Kennelly, Sean P

    2017-12-02

    The collateral (or informant) history is a key component in the assessment of older adults presenting with a memory problem or concern over cognition. Despite this, it rarely features in medical literature and academic curricula. Its role in general practice has never been assessed. The aim of this study is to assess the role of the collateral history in the investigation of cognitive impairment in general practice. An online survey distributed to three nationally representative cohorts of GPs in Ireland (n = 692). Ninety-five (14%; 52.2% male) responded. Nearly all (87%; 83/95) indicate that it is most often a family member who brings possible cognitive impairment to the attention of their GP. The vast majority obtain a collateral history in > 90% of cases (72.6%; 69/95) and rate it very useful in their clinical assessment of cognition. GPs report the collateral history as readily available and rarely refused, with the general practice environment well-suited to obtaining collateral histories. A small minority routinely use the GPCOG informant section (3.2%; 3/95). Nearly all (92.6%; 88/95) report having received no training in obtaining collateral histories with most (79%; 75/95) welcoming of further training in this area. Despite recognition of the utility and importance of the collateral history, the vast majority of GPs report having never received training in obtaining one and do not use structured tools to guide their interview. Further emphasis on the informant history as a distinct clinical entity on medical curricula and increasing emphasis on the availability of structured informant tools are warranted.

  5. Collateral status and tissue outcome after intra-arterial therapy for patients with acute ischemic stroke.

    Science.gov (United States)

    Boers, Anna Mm; Jansen, Ivo Gh; Berkhemer, Olvert A; Yoo, Albert J; Lingsma, Hester F; Slump, Cornelis H; Roos, Yvo Bwem; van Oostenbrugge, Robert J; Dippel, Diederik Wj; van der Lugt, Aad; van Zwam, Wim H; Marquering, Henk A; Majoie, Charles Blm

    2017-11-01

    Intra-arterial therapy (IAT) for ischemic stroke aims to save brain tissue. Collaterals are thought to contribute to prolonged penumbra sustenance. In this study, we investigate the effect of collateral status on brain tissue salvage with IAT. In 500 patients randomized between IAT and standard care, collateral status was graded from 0 (absent) to 3 (good). Final infarct volumes (FIV) were calculated on post-treatment CT. FIVs were compared between treatment groups per collateral grade. Multivariable linear regression with interaction terms was performed to study whether collaterals modified IAT effect on FIV. Four-hundred-forty-nine patients were included in the analysis. Median FIV for the IAT group was significantly lower with 54.5 mL (95% IQR: 21.8-145.0) than for the controls with 81.8 mL (95% IQR: 40.0-154.0) ( p = 0.020). Treatment effect differed across collateral grades, although there was no significant interaction (unadjusted p = 0.054; adjusted p = 0.105). For grade 3, IAT resulted in a FIV reduction of 30.1 mL ( p = 0.024). For grade 2 and 1, this difference was, respectively, 28.4 mL ( p = 0.028) and 28.4 mL ( p = 0.29). For grade 0, this was 88.6 mL ( p = 0.28) in favour of controls. IAT saves substantially more brain tissue as compared to standard care. We observed a trend of increasing effect of IAT with higher collateral grades.

  6. Embolization for Thoracic Duct Collateral Leakage in High-Output Chylothorax After Thoracic Surgery

    International Nuclear Information System (INIS)

    Kariya, Shuji; Nakatani, Miyuki; Yoshida, Rie; Ueno, Yutaka; Komemushi, Atsushi; Tanigawa, Noboru

    2017-01-01

    PurposeThis study was designed to investigate thoracic duct collateral leakage and the supply route of lymphatic fluid by lymphangiography and transcatheter thoracic ductography and to evaluate the results of embolization for thoracic duct collateral leakage performed to cut off this supply route.MethodsData were retrospectively collected from five patients who underwent embolization for thoracic duct collateral leakage in persistent high-output chylothorax after thoracic surgery. Extravasation of lipiodol at the ruptured thoracic duct collaterals was confirmed in all patients on lymphangiography. Transcatheter thoracic ductography was used to identify extravasation of iodinated contrast agent and to identify communication between the thoracic duct and leakage site. Thoracic duct embolization (TDE) was performed using the percutaneous transabdominal approach to cut off the supply route using N-butyl cyanoacrylate (NBCA) mixed with lipiodol (1:5–1:20).ResultsClinical success (drainage volume ≤10 mL/kg/day within 7 days after TDE) was achieved in all patients. The collateral routes developed as consequence of surgical thoracic duct ligation. In three patients, NBCA-Lipiodol reached the leakage site through direct communication between the thoracic duct and the ruptured lymphatic duct. In the other two patients, direct communication and extravasation was not detected on thoracic ductography, and NBCA-Lipiodol did not reach the leakage site. However, NBCA-Lipiodol did reach the cisterna chyli, lumbar trunks, and some collateral routes via the cisterna chyli or lumbar lymphatics. As a result, leakage was stopped.ConclusionsTDE was effective for the management of leakage of the collaterals in high-output chylothorax after thoracic surgery.

  7. Tl myocardial SPECT demonstrates importance of collateral circulation in patients with myocardial infarction

    International Nuclear Information System (INIS)

    Hattori, Fukunori

    1997-01-01

    The influence of collateral circulation on the preservation of myocardial viability and the efficacy of drug therapy and PTCA were evaluated by exercise 201 Tl myocardial SPECT before and after treatment. Thirty-five patients with a history of myocardial infarction resulting from total or subtotal obstruction of the responsible coronary artery were divided into four groups, according to the method of the treatment and the degree of collateral blood flow. Patients in groups A and B received drug therapy and displayed developed and undeveloped collateral circulation, respectively. Groups C and D received PTCA and displayed developed and undeveloped collateral circulation, respectively. Tl myocardial SPECT was performed before treatment to record the extent of redistribution to the occluded region, the degree of myocardial viability and the nature and extent of the ischemic lesion. In group A, myocardial perfusion improved, although redistribution remained in all cases, while in group B, 4 of 7 cases improved after drug therapy. In group C, myocardial perfusion improved in all cases, and redistribution disappeared in 7 of 12 cases. 5 of 6 cases improved in group D after PTCA. After drug therapy, the %Tl uptake in the infarcted region improved significantly in initial and delayed images of patients in group A. The differences in initial and delayed images in group B before and after drug therapy were not significant. In contrast, groups C and D both registered significant improvement in initial and delayed images after PTCA. The washout rate improved significantly in groups A, C and D after their respective treatments. These results suggest that developed collateral circulation helps to preserve myocardial viability in cases of myocardial infarction. Myocardial perfusion improved after drug therapy in cases with developed collateral circulation, and in patients with developed and undeveloped collateral circulation receiving PTCA. (K.H.)

  8. Hyperintense vessels on FLAIR: A useful non-invasive method for assessing intracerebral collaterals

    International Nuclear Information System (INIS)

    Liu Wenhua; Xu Gelin; Yue Xuanye; Wang Xiaoliang; Ma Minmin; Zhang Renliang; Wang Handong; Zhou Changsheng; Liu Xinfeng

    2011-01-01

    Objective: This study was aimed to evaluate relationship between hyperintense vessels (HV) on fluid-attenuated inversion recovery (FLAIR) and artery steno-occlusion related intracerebral collaterals. Materials and methods: A total of 233 patients with 260 atherosclerotic lesions in the M1 segment of the middle cerebral artery (MCA) were examined with FLAIR and digital subtraction angiography (DSA). HV were graded as 0, 1, 2 and 3 by its distributions in the MCA territory. Grade 0 indicated no HV; Grade 1 indicated the HV limited in Sylvian fissure; Grade 2 indicated the HV limited in Sylvian fissure and the temporal-occipital junction; Grade 3 indicated the HV extended to frontal-parietal lobes. Collateral blood flows were classified by DSA results. The relationship between HV grades and patterns of collateral flows was analyzed. Results: HV were observed in 76 out of 260 hemispheres. For patients with Grade 1 HV, most of their collateral flows (80.8%) were antegrade; for patients with Grade 2, the retrograde leptomeningeal flows were commonly manifested as anterior cerebral artery to MCA (75%); for patients with Grade 3 HV, most of the retrograde leptomeningeal flows were manifested as posterior cerebral artery to MCA (81.8%). As the grade HV increased, the frequency of retrograde leptomeningeal collateral from ACA to MCA decreased (100% to 75% and to 18.2%), and increased (0% to 25% and to 81.8%) for the retrograde leptomeningeal collateral via PCA to MCA (P < 0.001). Conclusions: The HV could assess non-invasively intracerebral collaterals in patients with steno-occlusive lesions of M1 segment of MCA.

  9. Prominent central spinal canal on MRI - normal variant or pathology

    International Nuclear Information System (INIS)

    Dugal, T.P.; Brazier, D.; Roche, J.

    2002-01-01

    Full text: The sensitivity of MRI can make differentiation of normal from abnormal challenging.The study investigates whether a visible central spinal canal is pathological or a normal variant. We review eight MRI (mostly on a 1.5 Tesla unit) cases where there is a visible central cavity in keeping with a central canal and review the literature. The central canal is a space in the medial part of the grey-matter commissure between the anterior and posterior horns. Histopathological studies show that the canal is present at birth with the majority showing subsequent involution but is uncommonly imaged on MRI. The main differential diagnosis is syringomyelia which usually presents with deficits in pain and sensation corresponding to the appropriate level often with a demonstrable aetiology. Two thirds of our patients were female with an average age of thirty-six years (range 26-45). The patients were largely asymptomatic or their symptoms appeared unrelated to the imaging findings. Three patients had minor previous trauma and two others had non-bacterial meningitis up to twenty years earlier. No patient had known spinal surgery or trauma.The cavity corresponded tomographically to the expected site of the central canal. The canal was in the thoracic location. The canal diameter ranged from one to five millimetres and its length varied from one half a vertebral body height to extending over the entire thoracic region. Its configuration was either filiform or fusiform, with smooth contours. No predisposing features to suggest syringomyelia or other structural abnormalities were noted. Where Gadolinium was given no abnormal enhancement was observed. These cases add to the literature and suggest that these prominent canals are largely asymptomatic and should be viewed as normal variants. Copyright (2002) Blackwell Science Pty Ltd

  10. Role of collateral circulation in the course of coronary heat disease (10-year clinical and angiographic follow-up)

    International Nuclear Information System (INIS)

    Tsapaeva, N.L.

    1999-01-01

    Results of the 10-year prospective follow-up of 59 ischemia patients with stenocardia are presented. Coronarography was made in all the patients whose coronary arteries and collateral blood flow were assessed. The experimental group comprised 37 patients with ischemia and collateral circulatory insufficiency. The control group included 22 patients with effective collateral circulation. The experimental group showed a worse prognosis than did the control one. Myocardial infarction developed in 54 and 27 % of cases, ischemia mortality was 29.7 and 9 % in the experimental and control groups, respectively. Effective collateral circulation is prerequisite of successful surgical myocardial revascularization [ru

  11. Morphology of the medial collateral ligament of the knee

    Directory of Open Access Journals (Sweden)

    Gill Thomas J

    2010-09-01

    Full Text Available Abstract Background Quantitative knowledge on the anatomy of the medial collateral ligament (MCL is important for treatment of MCL injury and for MCL release during total knee arthroplasty (TKA. The objective of this study was to quantitatively determine the morphology of the MCL of human knees. Methods 10 cadaveric human knees were dissected to investigate the MCL anatomy. The specimens were fixed in full extension and this position was maintained during the dissection and morphometric measurements. The outlines of the insertion sites of the superficial MCL (sMCL and deep MCL (dMCL were digitized using a 3D digitizing system. Results The insertion areas of the superficial MCL (sMCL were 348.6 ± 42.8 mm2 and 79.7 ± 17.6 mm2 on the tibia and femur, respectively. The insertion areas of the deep MCL (dMCL were 63.6 ± 13.4 mm2 and 71.9 ± 14.8 mm2 on the tibia and femur, respectively. The distances from the centroids of the tibial and femoral insertions of the sMCL to the tibial and femoral joint line were 62.4 ± 5.5 mm and 31.1 ± 4.6 mm, respectively. The distances from the centroids of dMCL in the tibial insertion and the femoral insertion to the tibial and femoral joint line were 6.5 ± 1.3 mm and 20.5 ± 4.2 mm, respectively. The distal portion of the dMCL (meniscotibial ligament - MTL was approximately 1.7 times wider than the proximal portion of the dMCL (meniscofemoral ligament - MFL, whereas the MFL was approximately 3 times longer than the MTL. Conclusions The morphologic data on the MCL may provide useful information for improving treatments of MCL-related pathology and performing MCL release during TKA.

  12. Collateral sources of costal and crural diaphragmatic blood flow

    International Nuclear Information System (INIS)

    Lockhat, D.; Magder, S.; Roussos, C.

    1985-01-01

    We measured the contribution of aortic, internal mammary, and intercostal arteries to the blood flow to the costal and crural segments of the diaphragm and other respiratory muscles in seven dogs breathing against a fixed inspiratory elastic load. We used radiolabeled microspheres to measure the blood flow with control circulation, occlusion of the aorta distal to the left subclavian artery, combined occlusion of the aorta and both internal mammary arteries, and occlusion of internal mammary arteries alone. With occlusion of the aorta distal to the left subclavian artery, blood flow to the crural diaphragm decreased from 40.3 to 23.5 ml . min-1 X 100 g-1, whereas costal flow did not change significantly (from 41.7 to 38.1 ml . min-1 . 100 g-1). Blood flows to the sternomastoid and scalene muscles (above the occlusion) increased by 200 and 340%, respectively, whereas flows to the other respiratory muscles did not change significantly. Blood flows to organs above the occlusion either remained unchanged or increased, whereas flows to those below the occlusion all decreased. When the internal mammary artery was also occluded, flows to the crural segment decreased further to 12.1 and costal flow decreased to 20.4 ml X min-1 X 100 g-1. Internal mammary arterial occlusion alone in two dogs had no effect on diaphragmatic flow. In conclusion, intercostal collateral vessels are capable of supplying a significant proportion of blood flow to both segments of the diaphragm but the costal segment is better served than the crural segment

  13. Unexpected collateral effects of simulation-based medical education.

    Science.gov (United States)

    Barsuk, Jeffrey H; Cohen, Elaine R; Feinglass, Joe; McGaghie, William C; Wayne, Diane B

    2011-12-01

    Internal medicine residents who complete simulation-based education (SBE) in central venous catheter (CVC) insertion acquire improved skills that yield better patient care outcomes. The collateral effects of SBE on the skills of residents who have not yet experienced SBE are unknown. In this retrospective, observational study, the authors used a checklist to test the internal jugular and subclavian CVC insertion skills of 102 Northwestern University second- and third-year internal medicine residents before they received simulation training. The authors compared, across consecutive academic years (2007-2008, 2008-2009, 2009-2010), mean pretraining scores and the percent of trainees who met or surpassed a minimum passing score (MPS). Mean internal jugular pretest scores improved from 46.7% (standard deviation = 20.8%) in 2007 to 55.7% (±22.5%) in 2008 and 70.8% (±22.4%) in 2009 (P < .001). Mean subclavian pretest scores changed from 48.3% (±25.5%) in 2007 to 45.6% (±31.0%) in 2008 and 63.6% (±27.3%) in 2009 (P = .04). The percentage of residents who met or surpassed the MPS before training for internal jugular insertion was 7% in 2007, 16% in 2008, and 38% in 2009 (P = .004); for subclavian insertion, the percentage was 11% in 2007, 19% in 2008, and 38% in 2009 (P = .028). SBE for senior residents had an effect on junior trainees, as evidenced by pretraining CVC insertion skill improvement across three consecutive years. SBE for a targeted group of residents has implications for skill acquisition among other trainees.

  14. Collateral Flow and White Matter Disease in Patients with Internal Carotid Artery Occlusion.

    Science.gov (United States)

    Ishikawa, Mami; Sugawara, Hitoshi; Nagai, Mutsumi; Kusaka, Gen; Tanaka, Yuichi; Naritaka, Heiji

    2017-01-01

    When an internal carotid artery (ICA) occludes, a patient may develop cerebral infarction (CI). We investigated whether CI caused by ICA occlusion (ICAO) is associated with collateral flow through the anterior and posterior communicating arteries (ACoA and PCoA). In 100 patients with ICAO, we investigated CI and white matter disease by performing an MRI and the anatomy of the ACoA and PCoA were investigated by performing magnetic resonance angiography. All patients were divided into the symptomatic CI group or the no-CI group. The collateral flow pathway was estimated by the anterior cerebral artery (ACA)-PCoA score and the collateral flow volume after ICAO was estimated by the middle cerebral artery (MCA) flow score, based on how well the MCA was visualized. Of 100 patients with ICAO, the symptomatic CI group included 36 patients. ACA-PCoA score and white matter disease grades were significantly higher in the CI group (indicating poor collateral flow). More than 80% of patients with an ACA-PCoA score of 4 (poor collateral) experienced symptomatic CI. Thirty-one symptomatic CI patients (86%) had an MCA flow score of 1 or 2 (decreased MCA flow). The ACA-PCoA score and white matter disease grade may suggest an increased risk of CI following ICAO. © 2016 S. Karger AG, Basel.

  15. Embolization of Collateral Vessels Using Mechanically Detachable Coils in Young Children with Congenital Heart Disease

    International Nuclear Information System (INIS)

    Sato, Y.; Ogino, H.; Hara, M.; Satake, M.; Oshima, H.; Banno, T.; Mizuno, K.; Mishima, A.; Shibamoto, Y.

    2003-01-01

    Our objective was to evaluate the usefulness of embolizing collateral vessels using mechanically detachable coils (MDCs) in children aged 3 years or younger with congenital heart disease. The subjects were 8 children with congenital heart disease featuring collateral vessels (age 18 days-3 years): 3 with a single ventricle, 2 with the tetralogy of Fallot, 2 with pulmonary atresia, and 1 with a ventricular septal defect. The embolized vessels were the major aortopulmonary collateral artery (MAPCA) in 5 patients, the persistent left superior vena cava in 2, and the coronary arteriovenous fistula in 1. A 4 or a 5 F catheter was used as the guiding device, and embolization was performed using MDCs and other conventional coils introduced through the microcatheter. One patient had growth of new MAPCAs after embolization, and these MAPCAs were also embolized with MDCs. Thus, a total of 9 embolization procedures were performed in 8 patients. Complete occlusion of the collateral vessels was achieved in 8 of 9 procedures (89%). Seven of 8 patients (88%) had uneventful courses after embolization, and MDC procedures appeared to play important roles in avoiding coil migration and achievement of safe coil embolization. One patient who underwent MAPCA embolization showed no improvement in heart function and died 2 months and 19 days later. Embolization of collateral vessels using MDCs in young children with congenital heart disease can be an effective procedure and a valuable adjunct to surgical management

  16. Collateral Projections Innervate the Mammillary Bodies and Retrosplenial Cortex: A New Category of Hippocampal Cells

    Science.gov (United States)

    O’Mara, Shane M.

    2018-01-01

    To understand the hippocampus, it is necessary to understand the subiculum. Unlike other hippocampal subfields, the subiculum projects to almost all distal hippocampal targets, highlighting its critical importance for external networks. The present studies, in male rats and mice, reveal a new category of dorsal subiculum neurons that innervate both the mammillary bodies (MBs) and the retrosplenial cortex (RSP). These bifurcating neurons comprise almost half of the hippocampal cells that project to RSP. The termination of these numerous collateral projections was visualized within the medial mammillary nucleus and the granular RSP (area 29). These collateral projections included subiculum efferents that cross to the contralateral MBs. Within the granular RSP, the collateral projections form a particularly dense plexus in deep Layer II and Layer III. This retrosplenial termination site colocalized with markers for VGluT2 and neurotensin. While efferents from the hippocampal CA fields standardly collateralize, subiculum projections often have only one target site. Consequently, the many collateral projections involving the RSP and the MBs present a relatively unusual pattern for the subiculum, which presumably relates to how both targets have complementary roles in spatial processing. Furthermore, along with the anterior thalamic nuclei, the MBs and RSP are key members of a memory circuit, which is usually described as both starting and finishing in the hippocampus. The present findings reveal how the hippocampus simultaneously engages different parts of this circuit, so forcing an important revision of this network. PMID:29527569

  17. The collateral venous system in late pregnancy: A systematic review of the literature.

    Science.gov (United States)

    Humphries, Aimee; Stone, Peter; Mirjalili, S Ali

    2017-11-01

    Recent literature has reported an association between maternal supine sleep position and stillbirth during late pregnancy. In this position the gravid uterus almost completely obstructs the inferior vena cava. A small number of women experience supine hypotension, thought to be due in part to inadequate collateral venous circulation. The aim of this paper is to review the literature describing the anatomy of the collateral venous system and in particular the azygos system, the abdominal portion of which has not been well studied. A systematic review was conducted using the electronic databases: Medline, Embase, Scopus, and Google Scholar. Relevant anatomical and radiological literature concerning the azygos system in particular was reviewed. The search was limited to adult human studies only. The collateral venous system can be divided into superficial, intermediate and deep systems. The azygos system in particular provides immediate collateral venous circulation in the event of acute inferior vena caval obstruction. The abdominal portion of this pathway, including the ascending lumbar vein, has not been well studied and there are certain variations that can render it ineffective. In conclusion, the collateral venous system provides an alternative route for blood to flow back to the systemic circulation when acute occlusion of the inferior vena cava occurs in the supine position during late pregnancy. However, certain anatomical variations can render this pathway ineffective, and this could have implications for the development of supine hypotension and stillbirth in late pregnancy. Clin. Anat. 30:1087-1095, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  18. Internal thoracic artery collateral to the external iliac artery in chronic aortoiliac occlusive disease

    International Nuclear Information System (INIS)

    Kim, Jinna; Won, Jong Yun; Park, Sung Il; Lee, Do Yun

    2003-01-01

    To evaluate the incidence and angiographic findings of the collateral pathway involving the internal thoracic artery in patients with chronic aortoiliac occlusive disease. Between March 2000 and Februrary 2001, 124 patients at our hospital underwent angiographic evaluation of chronic aortoiliac occlusive disease, and in 15 of these complete obstruction or severe stenosis of the aortoiliac artery was identified. The aortograms and collateral arteriograms obtained, including internal thoracic arteriograms, as well as the medical records of the patients involved, were evaluated. In nine patients there was complete occlusion of the infrarenal aorta, or diffuse stenosis of 75% or more in the descending thoracic aorta, and in the other six, a patent aorta but complete occlusion or stenosis of 75% or more of the common iliac artery was demonstrated. Collateral perfusion via hypertrophied internal thoracic arteries and rich anastomoses between the superior and inferior epigastric arteries, reconstituting the external iliac artery, were noted in all fifteen patients, regardless of symptom duration, which ranged from six months to twelve years. In patients with chronic aortoiliac occlusive disease, the internal thoracic artery, along with visceral collaterals and those from the contralateral side, is one of the major parietal collateral pathways

  19. A novel method to assess pial collateralization from stroke perfusion MRI: subdividing Tmax into anatomical compartments

    International Nuclear Information System (INIS)

    Potreck, Arne; Seker, Fatih; Hoffmann, Angelika; Pfaff, Johannes; Bendszus, Martin; Heiland, Sabine; Pham, Mirko; Nagel, Simon

    2017-01-01

    To develop and validate a quantitative and observer-independent method to evaluate pial collateral circulation by DSC-perfusion MRI and test whether this novel method delivers diagnostic information which is redundant to or independent from conventional penumbra imaging by the mismatch approach. We retrospectively identified 47 patients with M1 occlusion who underwent MR diffusion/perfusion imaging and mechanical thrombectomy at our facility. By automated registration and segmentation, T max delays were attributed specifically to the pial, cortical and parenchymal compartments. The resulting pial volumes at delay were defined as the pial T max map-assessed collateral score (TMACS) and correlated with gold standard digital subtraction angiography (DSA). Mismatch ratio was assessed by conventional penumbra defining MRI criteria. Strong correlation was found between TMACS and angiographically assessed collateral score (Pearson ρ = -0.74, p < 0.001). In multiple logistic regression, both good collaterals according to TMACS [OR 4.3 (1.1-19, p = 0.04)] and mismatch ratio ≥ 3.5 [OR 12.3 (1.88-249, p = 0.03)] were independent predictors of favourable clinical outcome. Perfusion delay in the pial compartment, as evaluated by TMACS, closely reflects the extent of pial collaterals in gold-standard DSA. TMACS and mismatch ratio were found to be complementary predictors of a favourable clinical outcome, each adding independent predictive information. (orig.)

  20. Effect of dehydration on the development of collaterals in acute middle cerebral artery occlusion.

    Science.gov (United States)

    Chang, S-W; Huang, Y-C; Lin, L-C; Yang, J-T; Weng, H-H; Tsai, Y-H; Lee, T-H

    2016-03-01

    Recent large series studies have demonstrated that dehydration is common amongst stroke subjects and is associated with poor outcome. However, the effects of hydration status on the development of collaterals have never been discussed. In this study, the hypothesis that hydration status is an important factor for developing collaterals after acute middle cerebral artery (MCA) infarction was tested. Eighty-seven patients with acute infarction due to occlusion of the MCA were enrolled. Two collateral markers, posterior cerebral artery (PCA) laterality and fluid-attenuated inversion recovery hyperintense vessels (HVs) were assessed from magnetic resonance imaging. Dehydration status was defined by a nitrogen to creatinine ratio ≧ of 15. The associations between dehydration status and the development of collaterals were estimated. Sixty-one of 87 patients (70.1%) were identified as dehydrated. The development of PCA laterality and HVs shows a significant difference between dehydrated and euhydrated patients. A serum nitrogen to creatinine ratio Dehydration remained an independent negative predictor for the development of PCA laterality and HVs in the multivariate analysis. Hydration status is associated with the development of collateral flow after acute MCA occlusion. This preliminary study provides an imaging clue that hydration status and early hydration therapy could be important for acute stroke management. © 2016 EAN.

  1. A novel flow-based parameter of collateral function assessed by intracoronary thermodilution.

    Science.gov (United States)

    Lindner, Markus; Felix, Stephan B; Empen, Klaus; Reffelmann, Thorsten

    2014-04-01

    Currently, many methods for quantitation of coronary collateral function are based on intracoronary pressure measurements distal of an occluded balloon, which do not fully account for the dynamic nature of collateral flow. Therefore, a flow-based parameter of coronary collateral function based upon principles of thermodilution was evaluated. In 26 patients with a high-grade coronary artery stenosis, intracoronary hemodynamics were analyzed by the RadiAnalyzer system (St Jude Medical), including fractional flow reserve (FFR), index of microcirculatory resistance (IMR), and the pressure-based collateral flow index (CFI) during balloon occlusion and hyperemia (intravenous adenosine). Moreover, immediately after an intracoronary bolus of room-temperature saline, the balloon was occluded and the intracoronary temperature distal to the balloon was analyzed over time. The slope of the temperature-time curve was calculated after logarithmic transformation as an index of collateral blood flow (CBFI). The coefficient of variation between two measurements of CBFI amounted to 11 ± 2%. In patients with CFI ≥0.25, CBFI amounted to 0.55 ± 0.09, whereas in those with CFI function, and should be evaluated in further studies.

  2. Concurrent patellar fracture and lateral collateral ligament avulsion as a result of trauma in three horses.

    Science.gov (United States)

    McLellan, Jonathan; Plevin, Sarah; Taylor, Elizabeth

    2012-05-15

    3 horses were evaluated because of lameness and swelling of the stifle joint subsequent to trauma. All horses had characteristic clinical signs of stifle joint pain and effusion. A medial patellar fracture and lateral collateral ligament avulsion fracture were visible ultrasonographically in each. Radiography, including standard as well as flexed lateromedial, cranioproximal-craniodistal oblique (skyline patellar), and laterally stressed caudocranial views, revealed similar findings. Arthroscopic surgery to remove the patellar fracture was attempted in 1 horse with severe desmitis of the lateral collateral ligament; it remained lame afterward. The other 2 horses, with less severe collateral ligament damage, were managed conservatively and returned to athletic use, despite the lack of surgical intervention to repair the patellar fractures. Special radiographic views were necessary for diagnosis of medial patellar fracture and lateral collateral ligament avulsion fracture in the 3 horses. Ultrasonographic findings pertaining to the collateral ligament may be prognostically important in such situations. The severity of a fracture involving ligament avulsion may be the limiting factor in horses with this combined injury, and this factor should be considered prior to attempting surgical correction of patellar fractures.

  3. Resiliency and collateral learning in science in some students of cree ancestry

    Science.gov (United States)

    Sutherland, Dawn

    2005-07-01

    In the context of schooling, resiliency refers to the ability to thrive academically despite adverse circumstances. In this study the relationship between academic resilience and student's collateral learning is explored in 20 students of Cree ancestry. The individual resilience of each student was examined by identifying protective factors for school leaving within the microsystem of each student's ecological framework. Student responses to questions related to motivation and engagement were ranked. In addition, students' perception of the influence of family and peers on individual attributes toward schooling was ranked.To gain insight into the collateral learning aspects of science learning in Cree students, the participants in this study were asked to reflect on their learning strategies through the use of critical incidents. The relationship between collateral learning and resiliency was also explored.This study found that students possessing a greater number of protective factors were more likely to learn science in a way described by Jegede's collateral learning theory. Responses to critical incidents indicate some Cree students hold at least two sources of knowledge to explain some science concepts and therefore may adopt a collateral learning strategy. The importance these students place on earned or experiential knowledge is evident in the interviews. Some suggestions for classroom instruction are offered in conclusion.

  4. The role of VEGF and KDR polymorphisms in moyamoya disease and collateral revascularization.

    Directory of Open Access Journals (Sweden)

    Young Seok Park

    Full Text Available We conducted a case-control study to investigate whether vascular endothelial growth factor (VEGF -2578, -1154, -634, and 936 and kinase insert domain containing receptor (KDR -604, 1192, and 1719 polymorphisms are associated with moyamoya disease. Korean patients with moyamoya disease (n = 107, mean age, 20.9±15.9 years; 66.4% female and 243 healthy control subjects (mean age, 23.0±16.1 years; 56.8% female were included. The subjects were divided into pediatric and adult groups. Among the 64 surgical patients, we evaluated collateral vessel formation after 2 years and divided patients into good (collateral grade A or poor (collateral grade B and C groups. The frequencies and distributions of four VEGF (-2578, -1154, -634, and 936 and KDR (-604, 1192, and 1719 polymorphisms were assessed from patients with moyamoya disease and compared to the control group. No differences were observed in VEGF -2578, -1154, -634, and 936 or KDR -604, 1192, and 1719 polymorphisms between the control group and moyamoya disease group. However, we found the -634CC genotype occurred less frequently in the pediatric moyamoya group (p = 0.040 whereas the KDR -604C/1192A/1719T haplotype increased the risk of pediatric moyamoya (p = 0.024. Patients with the CC genotype of VEGF -634 had better collateral vessel formation after surgery. Our results suggest that the VEGF -634G allele is associated with pediatric moyamoya disease and poor collateral vessel formation.

  5. Impact of Collateral Status on Successful Revascularization in Endovascular Treatment: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Leng, Xinyi; Fang, Hui; Leung, Thomas W H; Mao, Chen; Xu, Yuming; Miao, Zhongrong; Liu, Liping; Wong, K S Lawrence; Liebeskind, David S

    2016-01-01

    Pre-treatment collateral status may be associated with the rates of successful revascularization in acute ischemic stroke patients receiving endovascular treatment (EVT). We conducted a systematic review and meta-analysis to synthesize relevant evidence currently available. Relevant full-text articles published in English since January 1, 2000, reporting associations between collateral status and successful reperfusion and/or recanalization in acute ischemic stroke patients receiving EVT in cohort or case-control studies, or randomized clinical trials, were retrieved through search of PubMed. Study selection, data extraction and study quality assessment were carried out by 2 investigators. Risk ratios (RR) were pooled for good vs. poor collaterals for the outcomes of successful reperfusion and recanalization, based on random-effects models. Subgroup analyses were conducted to explore for potential factors that might interfere with the effects of pre-treatment collateral status on reperfusion by EVT. In total, 27 studies (2,366 subjects) were included in qualitative analysis, among which 24 studies (2,239 subjects) were quantitatively analyzed. Overall, good pre-treatment collaterals significantly increased the rate of both successful reperfusion (RR 1.28, 95% CI 1.17-1.40; p collaterals. Subgroup analyses revealed that the effects of collateral status on successful reperfusion by EVT might be different between populations with different ethnicities. Good pre-treatment collaterals may enhance the rates of successful reperfusion and recanalization in EVT for acute ischemic stroke. This may partly explain the favorable effects of good pre-treatment collaterals on clinical outcomes of stroke patients receiving EVT. Thus, it would be valuable to assess the collateral status prior to EVT in acute ischemic stroke. But studies are needed to further verify if the positive effects of good collaterals on revascularization by EVT are restricted to certain subgroups of patients

  6. Morphology and Dynamics of Solar Prominences from 3D MHD Simulations

    Science.gov (United States)

    Terradas, J.; Soler, R.; Luna, M.; Oliver, R.; Ballester, J. L.

    2015-01-01

    In this paper we present a numerical study of the time evolution of solar prominences embedded in sheared magnetic arcades. The prominence is represented by a density enhancement in a background-stratified atmosphere and is connected to the photosphere through the magnetic field. By solving the ideal magnetohydrodynamic equations in three dimensions, we study the dynamics for a range of parameters representative of real prominences. Depending on the parameters considered, we find prominences that are suspended above the photosphere, i.e., detached prominences, but also configurations resembling curtain or hedgerow prominences whose material continuously connects to the photosphere. The plasma-β is an important parameter that determines the shape of the structure. In many cases magnetic Rayleigh-Taylor instabilities and oscillatory phenomena develop. Fingers and plumes are generated, affecting the whole prominence body and producing vertical structures in an essentially horizontal magnetic field. However, magnetic shear is able to reduce or even to suppress this instability.

  7. MORPHOLOGY AND DYNAMICS OF SOLAR PROMINENCES FROM 3D MHD SIMULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Terradas, J.; Soler, R.; Oliver, R.; Ballester, J. L. [Departament de Física, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Luna, M., E-mail: jaume.terradas@uib.es [Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife (Spain)

    2015-01-20

    In this paper we present a numerical study of the time evolution of solar prominences embedded in sheared magnetic arcades. The prominence is represented by a density enhancement in a background-stratified atmosphere and is connected to the photosphere through the magnetic field. By solving the ideal magnetohydrodynamic equations in three dimensions, we study the dynamics for a range of parameters representative of real prominences. Depending on the parameters considered, we find prominences that are suspended above the photosphere, i.e., detached prominences, but also configurations resembling curtain or hedgerow prominences whose material continuously connects to the photosphere. The plasma-β is an important parameter that determines the shape of the structure. In many cases magnetic Rayleigh-Taylor instabilities and oscillatory phenomena develop. Fingers and plumes are generated, affecting the whole prominence body and producing vertical structures in an essentially horizontal magnetic field. However, magnetic shear is able to reduce or even to suppress this instability.

  8. Collateral Circles in Carotid Artery Occlusion. A Comparative Study between CW Doppler and contrast angiography

    Energy Technology Data Exchange (ETDEWEB)

    Giraldi, C; Marconi, F; Parenti, G; Lenzi, B; Canapicchi, R; Padolecchia, R

    1986-01-01

    In order to evaluate the presence and efficacy of the different collateral circles, 98 patients with occlusion of the internal carotid artery between its origin and the origin of the ophtalmic artery, has been examined. Before contrast angiography, each patients was submitted to a Doppler examination with test of compression on the exsternal and common carotid arteries. The information on the collateral circles (Willis and pre-Willis) deriving from the Doppler examination seems to be interesting and more accurate. On the contrary, angiography allows a better visualisation of the extention of intercranial circles. These data show that the Doppler and angiographic techniques are complementary one to the other in the study of the collateral circles.

  9. Recruitable collateral blood flow index predicts coronary instent restenosis after percutaneous coronary intervention

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Thayssen, Per; Lassen, Jens Flensted

    2007-01-01

    AIMS: Collateral flow may influence long-term results after percutaneous coronary intervention (PCI) because of haemodynamic forces compete with the antegrade flow through the dilated lesion. The aim of the study was to assess the influence of recruitable collateral blood flow on restenosis...... in patients undergoing PCI with bare metal stents and using optimal antithrombotic treatment. METHODS AND RESULTS: In 95 patients, 95 de novo lesions were treated with PCI and a bare metal stent. Fractional flow reserve (FFR) at maximum hyperaemia induced by intravenous adenosine was determined. The pressure.......02-1.12, P = 0.016). CONCLUSION: Recruitable collateral blood flow measured during balloon inflation predicts angiographic instent restenosis in PCI patients treated with bare metal stents. Udgivelsesdato: 2007-Aug...

  10. Clinical study of the hypothesis of endogenous collateral wind on acute coronary syndrome: a review.

    Science.gov (United States)

    Wang, Xian; Zhang, Cong; Yang, Ran; Zhu, Haiyan; Zhao, Huaibing; Li, Xiaoming

    2014-01-01

    Acute Coronary Syndrome (ACS), is a serious threat to people's health, and life, and in recent years, the incidence has increased yearly. This study was to propose the hypothesis of "endogenous collateral wind" based on the patho-mechanism of thrombogenesis complicated by ruptured plaque on ACS, and the theory of traditional Chinese medicine. Through successful coronary angiography (CAG), and intravascular ultrasound (IVUS), patients with coronary artery disease were made the differential diagnosis such as blood stasis, blood stasis due to phlegm obstruction, and endogenous collateral wind. The levels of plasma inflammatory marker were measured to study on the characteristics of "endogenous collateral wind". Luo heng dripping pills with promoting blood circulation to expel wind-evil, and remove wetness were made based on the hypothesis of "endogenous collateral wind" on ACS. Patients with unstable angina were randomly divided into 3, groups based on therapeutic methods: conventional therapy group, Luo Heng dripping pills group and Tongxinluo caps. Differences among groups were compared. There were great changes in number and degree of coronary arteriostenosis confirmed by CAG, the types of ACC/AHA lesion and Levin lesion confirmed by CAG, remodeling index, positive or negative remodeling percentage measured by IVUS, the plasma levels of plasma inflammatory marker measured by ELLSA in the patients with endogenous collateral wind, compared with patients with blood stasis and blood stasis due to phlegm obstruction. The total effective rate of improved angina in Luo Heng dripping pills group was significantly higher than those in other two groups. The levels of plasma inflammatory marker were significantly lower in Luo Heng dripping pills group. There were some pathological basis which were found about the hypothesis of "endogenous collateral wind" on acute coronary syndrome. It provided evidences for patients with coronary artery disease treated by medicines with

  11. The "moving valgus stress test" for medial collateral ligament tears of the elbow.

    Science.gov (United States)

    O'Driscoll, Shawn W M; Lawton, Richard L; Smith, Adam M

    2005-02-01

    The diagnosis of a painful partial tear of the medial collateral ligament in overhead-throwing athletes is challenging, even for experienced elbow surgeons and despite the use of sophisticated imaging techniques. The "moving valgus stress test" is an accurate physical examination technique for diagnosis of medial collateral ligament attenuation in the elbow. Cohort study (diagnosis); Level of evidence, 2. Twenty-one patients underwent surgical intervention for medial elbow pain due to medial collateral ligament insufficiency or other abnormality of chronic valgus overload, and they were assessed preoperatively with an examination called the moving valgus stress test. To perform the moving valgus stress test, the examiner applies and maintains a constant moderate valgus torque to the fully flexed elbow and then quickly extends the elbow. The test is positive if the medial elbow pain is reproduced at the medial collateral ligament and is at maximum between 120 degrees and 70 degrees. The moving valgus stress test was highly sensitive (100%, 17 of 17 patients) and specific (75%, 3 of 4 patients) when compared to assessment of the medial collateral ligament by surgical exploration or arthroscopic valgus stress testing. The mean shear range (ie, the arc within which pain was produced with the moving valgus stress test) was 120 degrees to 70 degrees. The mean angle at which pain was at a maximum was 90 degrees of elbow flexion. The moving valgus stress test is an accurate physical examination technique that, when performed and interpreted correctly, is highly sensitive for medial elbow pain arising from the medial collateral ligament.

  12. Effects of nicorandil on coronary collateral circulation depend on the donor arteries

    International Nuclear Information System (INIS)

    Umezawa, Shigeo; Ogawara, Shigeko; Okamoto, Yoshihiro; Igawa, Masayuki; Aonuma, Kazutaka; Inada, Mihoe; Korenaga, Masayoshi; Hiroe, Michiaki; Marumo, Fumiaki.

    1996-01-01

    The effects of nicorandil on coronary collateral circulation during exercise-induced ischemia were compared between the different donor arteries in 13 patients with effort angina, 7 with complete obstruction of the left anterior descending artery (LAD) with well-developed collateral vessels from the right coronary artery (RCA) (LAD group), and 6 with complete occlusion of the RCA (segment 2-3) with well-developed collateral vessels from the LAD (RCA group). Initial percentage thallium (%Tl) uptake (thallium-201 single photon emission computed tomography) and washout rate were measured in the anterior, septal and posterior regions during ergometer exercise. The submaximal treadmill exercise test was also performed using a cardiopulmonary monitoring system to measure Vo 2 at anaerobic threshold (AT). After the controls were obtained, nicorandil (15 mg/day) was administered for 4 weeks, during which ergometer exercise and treadmill exercise tests were carried out repeatedly. A significant improvement of initial %Tl uptake on exercise was observed in the LAD group with nicorandil therapy, but no improvement was shown in the RCA group. The AT significantly increased after nicorandil treatment in the LAD group (13.9±0.38 → 16.8±1.18 ml/min/kg), reflecting the improvement of cardiac function through the increased collateral flow. However, in the RCA group, it remained unchanged, suggesting no improvement of cardiac function. Nicorandil was effective to increase collateral flow from the RCA, but ineffective on that from the LAD. Nicorandil is an effective coronary dilator and is reported to affect both large and small coronary arteries. The effect on the collateral circulation is dependent on the donor artery supplying different areas. The vasodilator effect of nicorandil is mainly on the LAD, which is large enough to supply blood to a wider area of the heart, rather than the RCA. (author)

  13. FEATURES OF FORMATION OF COLLATERAL CIRCULATION IN PATIENTS WITH SUBCLAVIAN STEAL SYNDROME.

    Science.gov (United States)

    Kopolovets, I; Štefanič, P; Rusyn, V; Tóth, Š; Mashura, V; Berek, P

    2017-12-01

    To date in patients with subclavian steal syndrome diagnosis is only grade of stenosis or localization of occlusion described. Authors recommend to take into account also type of a collateral compensation of cerebral circulation for selection of an optimal treatment The objective of the research was to study the features of formation of collateral circulation in patients with subclavian steal syndrome. The authors described changes in the direction of blood flow in the extracranial vessels of 42 patients with subclavian steal syndrome. Latent subclavian steal syndrome was detected in 26.2% of patients, transient subclavian steal syndrome was found in 54.8% of patients, and a persistent course of the disease was observed in 19.9% of patients. Symptoms of vertebrobasilar insufficiency were detected in 26.6% of patients, and combination of chronic upper extremity ischemia and vertebrobasilar insufficiency was diagnosed in 73.8% of patients. When analyzing the features of collateral circulation in 64.3% of patients the extracranial compensatory mechanism was observed being provided by three main groups of collateral hemodynamic reallocation: the occipito-vertebral hemodynamic mechanism of compensation was detected in 38.1% of cases, the thyroid compensatory mechanism was found in 16.7% of cases, and the brain stem-occipital compensatory mechanism was observed in 9.5% of cases. In 35.7% of patients the intracranial compensatory mechanism was observed being provided by two main groups of collateral hemodynamic reallocation: the vertebro-vertebral compensatory mechanism was found in 21.4% of cases and cerebrobasilar compensatory mechanism was detected in 14.3% of cases. Consideration of the features of collateral circulation in patients with subclavian steal syndrome may serve as a prognostic criterion for selecting an optimal treatment tactics.Each of compensatory mechanisms has its own hemodynamic peculiarities. The occipito- vertebral compensatory mechanism has the

  14. Collateral flow as causative of good outcomes in endovascular stroke therapy.

    Science.gov (United States)

    Sheth, Sunil A; Sanossian, Nerses; Hao, Qing; Starkman, Sidney; Ali, Latisha K; Kim, Doojin; Gonzalez, Nestor R; Tateshima, Satoshi; Jahan, Reza; Duckwiler, Gary R; Saver, Jeffrey L; Vinuela, Fernando; Liebeskind, David S

    2016-01-01

    Endovascular reperfusion techniques are a promising intervention for acute ischemic stroke (AIS). Prior studies have identified markers of initial injury (arrival NIH stroke scale (NIHSS) or infarct volume) as predictive of outcome after these procedures. We sought to define the role of collateral flow at the time of presentation in determining the extent of initial ischemic injury and its influence on final outcome. Demographic, clinical, laboratory, and radiographic data were prospectively collected on a consecutive cohort of patients who received endovascular therapy for acute cerebral ischemia at a single tertiary referral center from September 2004 to August 2010. Higher collateral grade as assessed by the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) grading scheme on angiography at the time of presentation was associated with improved reperfusion rates after endovascular intervention, decreased post-procedural hemorrhage, smaller infarcts on presentation and discharge, as well as improved neurological function on arrival to the hospital, discharge, and 90 days later. Patients matched by vessel occlusion, age, and time of onset demonstrated smaller strokes on presentation and better functional and radiographic outcome if found to have superior collateral flow. In multivariate analysis, lower collateral grade independently predicted higher NIHSS on arrival. Improved collateral flow in patients with AIS undergoing endovascular therapy was associated with improved radiographic and clinical outcomes. Independent of age, vessel occlusion and time, in patients with comparable ischemic burdens, changes in collateral grade alone led to significant differences in initial stroke severity as well as ultimate clinical outcome. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  15. Collateral sensitivity between aminoglycosides and beta-lactam antibiotics depends on active proton pumps.

    Science.gov (United States)

    Azimi, Leila; Rastegar Lari, Abdolaziz

    2017-11-01

    Selection inversion is the hypothesis for antibiotic resistant inhabitation in bacteria and collateral sensitivity is one of the proposed phenomena for achievement of this hypothesis. The presence of collateral sensitivity associated with the proton motivation pump between the aminoglycosides and beta-lactam group of antibiotics is one of the examples of collateral sensitivity in some studies. The aim of this study was to demonstrate that collateral sensitivity between aminoglycosides and beta-lactam antibiotics associated with proton motivation pump may not be true in all cases. In this study, 100 Pseudomonas aeruginosa were surveyed. Gentamicin and imipenem-resistant strains were confirmed by disc diffusion method and MIC. Active proton motivation pumps were screened by pumps inhibitor. Semi-quantitative Real-Time PCR assay was used to confirm gene overexpression. Seventy-six and 79 out of 100 strains were resistant to gentamicin and imipenem, respectively. Seventy-five strains were resistant to both gentamicin and imipenem. The results of proton pump inhibitor test showed the involvement of active proton motivation pump in 22 of 75 imipenem- and gentamicin-resistant strains. According to Real - Time PCR assay, mexX efflux gene was overexpressed in the majority of isolates tested. The collateral sensitivity effect cannot explain the involvement of active proton motivation pumps in both imipenem and gentamicin-resistant strains simultaneously. Active and/or inactive proton pump in gentamicin-sensitive and/or resistant strains cannot be a suitable example for explanation of collateral sensitivity between aminoglycosides and beta-lactam antibiotics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Genetic Dissection of the Canq1 Locus Governing Variation in Extent of the Collateral Circulation

    Science.gov (United States)

    Wang, Shiliang; Zhang, Hua; Wiltshire, Tim; Sealock, Robert; Faber, James E.

    2012-01-01

    Background Native (pre-existing) collaterals are arteriole-to-arteriole anastomoses that interconnect adjacent arterial trees and serve as endogenous bypass vessels that limit tissue injury in ischemic stroke, myocardial infarction, coronary and peripheral artery disease. Their extent (number and diameter) varies widely among mouse strains and healthy humans. We previously identified a major quantitative trait locus on chromosome 7 (Canq1, LOD = 29) responsible for 37% of the heritable variation in collateral extent between C57BL/6 and BALB/c mice. We sought to identify candidate genes in Canq1 responsible for collateral variation in the cerebral pial circulation, a tissue whose strain-dependent variation is shared by similar variation in other tissues. Methods and Findings Collateral extent was intermediate in a recombinant inbred line that splits Canq1 between the C57BL/6 and BALB/c strains. Phenotyping and SNP-mapping of an expanded panel of twenty-one informative inbred strains narrowed the Canq1 locus, and genome-wide linkage analysis of a SWRxSJL-F2 cross confirmed its haplotype structure. Collateral extent, infarct volume after cerebral artery occlusion, bleeding time, and re-bleeding time did not differ in knockout mice for two vascular-related genes located in Canq1, IL4ra and Itgal. Transcript abundance of 6 out of 116 genes within the 95% confidence interval of Canq1 were differentially expressed >2-fold (p-valuecollateral formation. Conclusions These findings refine the Canq1 locus and identify several genes as high-priority candidates important in specifying native collateral formation and its wide variation. PMID:22412848

  17. Angiographic findings of collateral vessels in cervicofacial vascular lesions with previously ligated carotid artery

    International Nuclear Information System (INIS)

    Na, Dong Gyu; Han, Moon Hee; Chang, Kee Hyun; Han, Gi Seok; Yeon, Kung Mo

    1995-01-01

    The purpose of this study is to describe the angiographic findings of collateral vessels in cervicofacial vascular lesions with previously ligated carotid arteries and to evaluate the extent of angiographic assessment needed before embolization. We retrospectively reviewed 10 cervicofacial vascular lesions with previously ligated carotid artery, which were 6 cases of arteriovenous malformation, 2 cases of carotid cavernous fistula, 1 case of hemangioma and 1 case of arteriovenous malformation with carotid cavernous fistula. The previously ligated arteries are proximal external carotid artery (n = 5), branches of external carotid artery (n = 2) and common carotid artery (n = 3). Common carotid artery or internal carotid artery (n = 9), vertebral artery (n = 5), ipsilateral external carotid artery (n = 4), contralateral external carotid artery (n = 5), costocervical trunk (n = 2), thyrocervical trunk (n = 2) were assessed by conventional angiography. Angiography of both carotid and vertebral arteries was performed in 5 cases. The collateral vascular channels were inferolateral trunk of internal carotid artery (n = 8), vertebral artery (n = 5), contralateral external carotid artery (n = 5), ipsilateral external carotid artery (n = 4), deep cervical artery (n = 2) and ascending cervical artery (n = 1). Embolization were performed in 9 cases with operative cannulation (n = 4), embolization via collateral branches of ipsilateral external carotid artery (n = 1), embolization via collateral branches of contralateral external carotid artery (n = 3) and balloon occlusion via direct puncture (n = 1). The collateral channels in cervicofacial vascular lesions with previously ligated carotid artery were inferolateral trunk of internal carotid artery, contralateral or ipsilateral external carotid artery, vertebral artery, deep cervical artery and ascending cervical artery on angiography. Complete angiographic assessment of possible collateral channels is mandatory for the

  18. The Impact of Variational Primary Collaterals on Cerebral Autoregulation

    Directory of Open Access Journals (Sweden)

    Zhen-Ni Guo

    2018-06-01

    Full Text Available The influence of the anterior and posterior communicating artery (ACoA and PCoA on dynamic cerebral autoregulation (dCA is largely unknown. In this study, we aimed to test whether substantial differences in collateral anatomy were associated with differences in dCA in two common types of stenosis according to digital subtraction angiography (DSA: either isolated basal artery and/or bilateral vertebral arteries severe stenosis/occlusion (group 1; group 1A: with bilateral PCoAs; and group 1B: without bilateral PCoAs, or isolated unilateral internal carotid artery severe stenosis/occlusion (group 2; group 2A: without ACoA and with PCoA; group 2B: with ACoA and without PCoAs; and group 2C: without both ACoA and PCoA. The dCA was calculated by transfer function analysis (a mathematical model, and was evaluated in middle cerebral artery (MCA and/or posterior cerebral artery (PCA. Of a total of 231 non-acute phase ischemic stroke patients who received both dCA assessment and DSA in our lab between 2014 and 2017, 51 patients met inclusion criteria based on the presence or absence of ACoA or PCoA, including 21 patients in the group 1, and 30 patients in the group 2. There were no significant differences in gender, age, and mean blood pressure between group 1A and group 1B, and among group 2A, group 2B, and group 2C. In group 1, the PCA phase difference values (autoregulatory parameter were significantly higher in the subgroup with patent PCoAs, compared to those without. In group 2, the MCA phase difference values were higher in the subgroup with patent ACoA, compared to those without. This pilot study found that the cross-flow of the ACoA/PCoA to the affected area compensates for compromised dCA in the affected area, which suggests an important role of the ACoA/PCoA in stabilizing cerebral blood flow.

  19. 46 CFR 308.526 - Certificate for repayment of decrease of collateral deposit fund, Form MA-306.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Certificate for repayment of decrease of collateral... TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Ii-Open Policy War Risk Cargo Insurance § 308.526 Certificate for repayment of decrease of collateral deposit fund, Form MA-306. The...

  20. 46 CFR 308.525 - Application for decrease in amount of cash collateral fund, Form MA-305.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Application for decrease in amount of cash collateral... TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Ii-Open Policy War Risk Cargo Insurance § 308.525 Application for decrease in amount of cash collateral fund, Form MA-305. Application for...

  1. Impact of Collateral Status Evaluated by Dynamic Computed Tomographic Angiography on Clinical Outcome in Patients With Ischemic Stroke

    NARCIS (Netherlands)

    van den Wijngaard, Ido R.; Boiten, Jelis; Holswilder, Ghislaine; Algra, Ale; Dippel, Diederik W J; Velthuis, Birgitta K.; Wermer, Marieke J H; van Walderveen, Marianne A A

    2015-01-01

    BACKGROUND AND PURPOSE—: Status of collateral circulation is a strong predictor of outcome after acute ischemic stroke. Our aim was to compare the predictive value of strategies for collateral blood flow assessment with dynamic computed tomographic angiography (CTA) and conventional single-phase CT

  2. Physiologic capacity of well-developed collaterals in patients with isolated left anterior descending artery disease

    International Nuclear Information System (INIS)

    Sakata, Kazuyuki; Yoshida, Hiroshi; Ono, Norihisa; Ohtani, Seiji; Mori, Noriko; Yokoyama, Shoichi; Hoshino, Tsuneo; Kaburagi, Tsuneo; Kurata, Chinori.

    1992-01-01

    To assess the physiologic significance of well-developed collaterals, 34 patients, with isolated left anterior descending artery disease (LAD) and without overt prior myocardial infarction, underwent cardiac catheterization and exercise thallium-201 emission computed tomography. The patients were divided into 3 groups: 11 patients with 90% stenosis of the proximal LAD and without collaterals (group 1), 11 with 99% stenosis of the proximal LAD, and without collaterals (group 2) and 12 with a total occlusion of the proximal LAD which was completely filled by well-developed collaterals (group 3). On left ventriculography, shortening fractions of the anterior wall were significantly reduced in group 2 as compared to groups 1 and 3 (group 1 vs group 2: p<0.01, group 2 vs group 3: p<0.05), which reflected the lower ejection fraction of group 2 (p<0.01 and p<0.05, respectively). The perfusion defects of the anterior wall on both the initial and the delayed images were severer in groups 2 and 3 than in group 1 (group 1 vs group 2 and group 1 vs group 3 on the initial image: p<0.01, for both, group 1 vs group 2 and group 1 vs group 3 on the delayed image: p<0.05, for both). However, recovery of the perfusion defects from the initial image to the delayed image was better in group 3 than in groups 1 and 2 (group 1 vs group 2 and group 1 vs group 3: p<0.05, for both). Therefore, coronary blood flow through well-developed collaterals was considered to be comparable to the flow through a diseased vessel with 90% stenosis at rest. During maximal exercise, blood flow through well-developed collaterals was considered to be comparable to the flow through a diseased vessel with 99% stenosis, although the blood flow through well-developed collaterals was considered to be better than that through 99% stenosis during the recovery period. These findings suggest that patients with well-developed collaterals must be treated like those with severe stenosis. (author)

  3. Aberrant Ovarian Collateral Originating from External Iliac Artery During Uterine Artery Embolization

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Joon Ho; Kim, Man Deuk, E-mail: mdkim@yuhs.ac; Lee, Kwang-hun; Lee, Myungsu; Lee, Mu Sook; Won, Jong Yun; Park, Sung Il; Lee, Do Yun [Yonsei University College of Medicine, Department of Radiology, Research Institute of Radiological Science, Severance Hospital (Korea, Republic of)

    2013-02-15

    We report a case of a 35-year-old woman who underwent uterine artery embolization (UAE) for symptomatic multiple uterine fibroids with collateral aberrant right ovarian artery that originated from the right external iliac artery. We believe that this is the first reported case in the literature of this collateral uterine flow by the right ovarian artery originated from the right external iliac artery. We briefly present the details of the case and review the literature on variations of ovarian artery origin that might be encountered during UAE.

  4. Aberrant Ovarian Collateral Originating from External Iliac Artery During Uterine Artery Embolization

    International Nuclear Information System (INIS)

    Kwon, Joon Ho; Kim, Man Deuk; Lee, Kwang-hun; Lee, Myungsu; Lee, Mu Sook; Won, Jong Yun; Park, Sung Il; Lee, Do Yun

    2013-01-01

    We report a case of a 35-year-old woman who underwent uterine artery embolization (UAE) for symptomatic multiple uterine fibroids with collateral aberrant right ovarian artery that originated from the right external iliac artery. We believe that this is the first reported case in the literature of this collateral uterine flow by the right ovarian artery originated from the right external iliac artery. We briefly present the details of the case and review the literature on variations of ovarian artery origin that might be encountered during UAE.

  5. PENGEMBANGAN HAK KEKAYAAN INTELEKTUAL SEBAGAI COLLATERAL (AGUNAN UNTUK MENDAPATKAN KREDIT PERBANKAN DI INDONESIA

    Directory of Open Access Journals (Sweden)

    Sri Mulyani

    2012-03-01

    Full Text Available Intellectual Property Rights is granted the exclusive rights to creators, inventors or designers for the creation or invention that has commercial value, either directly or through the automatic registration of the relevant agencies as awards, recognition should be given the protection of the rights of the community development law. Globally, the IPR will be used as collateral to obtain a bank loan internasional. In this law is necessary to realize the concept of legislation in each country who are willing to apply that regulate substance loading, binding, and registration of intellectual property as collateral.

  6. Independent predictors of retrograde failure in CTO-PCI after successful collateral channel crossing.

    Science.gov (United States)

    Suzuki, Yoriyasu; Muto, Makoto; Yamane, Masahisa; Muramatsu, Toshiya; Okamura, Atsunori; Igarashi, Yasumi; Fujita, Tsutomu; Nakamura, Shigeru; Oida, Akitsugu; Tsuchikane, Etsuo

    2017-07-01

    To evaluate factors for predicting retrograde CTO-PCI failure after successful collateral channel crossing. Successful guidewire/catheter collateral channel crossing is important for the retrograde approach in percutaneous coronary intervention (PCI) for chronic total occlusion (CTO). A total of 5984 CTO-PCI procedures performed in 45 centers in Japan from 2009 to 2012 were studied. The retrograde approach was used in 1656 CTO-PCIs (27.7%). We investigated these retrograde procedures to evaluate factors for predicting retrograde CTO-PCI failure even after successful collateral channel crossing. Successful guidewire/catheter collateral crossing was achieved in 77.1% (n = 1,276) of 1656 retrograde CTO-PCI procedures. Retrograde procedural success after successful collateral crossing was achieved in 89.4% (n = 1,141). Univariate analysis showed that the predictors for retrograde CTO-PCI failure were in-stent occlusion (OR = 1.9829, 95%CI = 1.1783 - 3.3370 P = 0.0088), calcified lesions (OR = 1.9233, 95%CI = 1.2463 - 2.9679, P = 0.0027), and lesion tortuosity (OR = 1.5244, 95%CI = 1.0618 - 2.1883, P = 0.0216). On multivariate analysis, lesion calcification was an independent predictor of retrograde CTO-PCI failure after successful collateral channel crossing (OR = 1.3472, 95%CI = 1.0614 - 1.7169, P = 0.0141). The success rate of retrograde CTO-PCI following successful guidewire/catheter collateral channel crossing was high in this registry. Lesion calcification was an independent predictor of retrograde CTO-PCI failure after successful collateral channel crossing. Devices and techniques to overcome complex CTO lesion morphology, such as lesion calcification, are required to further improve the retrograde CTO-PCI success rate. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  7. Use of corrosion casting techniques to evaluate coronary collateral vessels and anastomoses in hearts of canine cadavers.

    Science.gov (United States)

    Noestelthaller, Arne; Probst, Alexander; Koenig, Horst E

    2005-10-01

    To study and investigate branching patterns of the canine coronary arteries and collateral circulation by use of corrosion casting techniques. 31 hearts obtained from cadavers of clinically normal dogs of various ages and breeds and of either sex. 3-dimensional reproduction of coronary arteries was achieved by postmortem injection and perfusion with casting materials into the aortic sinus via the ascending aorta. Perfused hearts were macerated and carefully irrigated; the air-dried specimens were examined macroscopically and with a magnifying headset. Collateral arteries and inter- and intra-arterial anastomoses were successfully detected in 8 corrosion cast specimens. In total, 9 coronary collateral arteries and 3 interarterial anastomoses were found. Our finding of coronary collateral arteries in canine hearts is in agreement with recent findings in coronary flow study. On the basis of our results, vasodilation treatment to improve collateral vessel remodeling in dogs with myocardial dysfunction may be warranted.

  8. Innate collateral segments are predominantly present in the subendocardium without preferential connectivity within the left ventricular wall

    Science.gov (United States)

    van Horssen, Pepijn; Siebes, Maria; Spaan, Jos A E; Hoefer, Imo E; van den Wijngaard, Jeroen P H M

    2014-01-01

    Functional collateral vessels often stem from outward remodelling of pre-existing connections between perfusion territories. Knowledge of the distribution and morphology of innate collateral connections may help in identifying myocardial areas with protection against risk for ischaemia. The coronary network of six healthy canine hearts was investigated with an imaging cryomicrotome. Innate collateral connections ranged from 286 to 1015 μm in diameter. Left ventricular collateral density (number per gram of tissue) was about five in the subendocardium vs. 2.5 in the mid-myocardium (P collateral connections were oriented parallel to the long axis of the heart. For the major coronary arteries, five times more intracoronary than intercoronary connections were found, while their median diameter and interquartile range were not significantly different, at 96.1 (16.9) vs. 94.7 (18.9) μm. Collateral vessels connecting crowns from sister branches from a stem are denoted intercrown connections and those within crowns intracrown connections. The number of intercrown connections was related to the mean tissue weight of the crowns (y = 0.73x − 0.33, r2 = 0.85, P collateral diameter and length were independent of the tissue volumes bridged. We conclude that connectivity and morphology of the innate collateral network are distributed with no preference for intra-or intercrown connections, independent of stem diameter, including epicardial arteries. This renders all sites of the myocardium equally protected in case of coronary artery disease. The orientation of subendocardial collateral vessels indicates the longitudinal direction of subendocardial collateral flow. PMID:24366260

  9. Innate collateral segments are predominantly present in the subendocardium without preferential connectivity within the left ventricular wall.

    Science.gov (United States)

    van Horssen, Pepijn; Siebes, Maria; Spaan, Jos A E; Hoefer, Imo E; van den Wijngaard, Jeroen P H M

    2014-03-01

    Functional collateral vessels often stem from outward remodelling of pre-existing connections between perfusion territories. Knowledge of the distribution and morphology of innate collateral connections may help in identifying myocardial areas with protection against risk for ischaemia. The coronary network of six healthy canine hearts was investigated with an imaging cryomicrotome. Innate collateral connections ranged from 286 to 1015 μm in diameter. Left ventricular collateral density (number per gram of tissue) was about five in the subendocardium vs. 2.5 in the mid-myocardium (P collateral connections were oriented parallel to the long axis of the heart. For the major coronary arteries, five times more intracoronary than intercoronary connections were found, while their median diameter and interquartile range were not significantly different, at 96.1 (16.9) vs. 94.7 (18.9) μm. Collateral vessels connecting crowns from sister branches from a stem are denoted intercrown connections and those within crowns intracrown connections. The number of intercrown connections was related to the mean tissue weight of the crowns (y = 0.73x - 0.33, r2 = 0.85, P collateral diameter and length were independent of the tissue volumes bridged. We conclude that connectivity and morphology of the innate collateral network are distributed with no preference for intra- or intercrown connections, independent of stem diameter, including epicardial arteries. This renders all sites of the myocardium equally protected in case of coronary artery disease. The orientation of subendocardial collateral vessels indicates the longitudinal direction of subendocardial collateral flow.

  10. A protective role of early collateral blood flow in patients with ST-segment elevation myocardial infarction.

    Science.gov (United States)

    Kim, Eun Kyoung; Choi, Jin-Ho; Song, Young Bin; Hahn, Joo-Yong; Chang, Sung-A; Park, Sung-Ji; Lee, Sang-Chol; Choi, Seung-Hyuk; Choe, Yeon Hyeon; Park, Seung Woo; Gwon, Hyeon-Cheol

    2016-01-01

    Conflict persists regarding whether the presence of early collateral blood flow to the infarct-related artery has an effective role in reducing infarct size and improving myocardial salvage in patients with ST-segment elevation myocardial infarction (STEMI). We sought to investigate the impact of the collateral circulation on myocardial salvage and infarct size in STEMI patients. In 306 patients who were diagnosed with STEMI and underwent cardiac magnetic resonance within 1 week after revascularization, initial collateral flow to the infarct-related artery was assessed by coronary angiography. Using cardiac magnetic resonance imaging, myocardial infarct size and salvage were measured. Among 247 patients with preprocedural Thrombolysis in Myocardial Infarction flow 0/1, 54 (22%) patients had good collaterals (Rentrop grade ≥ 2, Collateral Connection Score ≥ 2). Infarct size and area at risk were significantly smaller in patients with good collaterals than those with poor collaterals (infarct size: 17.1 ± 10.1 %LV vs 21.8 ± 10.5 %LV, P = .003, area at risk: 33.8 ± 16.8 %LV vs 38.8 ± 15.5 %LV, P = .039). There was a significant difference of myocardial salvage index between 2 groups (50.9% ± 15.0% vs 43.8% ± 18.5%, P = .005). Poor collateralization was an independent predictor for large infarct size (odd ratio 2.48 [1.28-4.80], P = .007). In patients with STEMI, the presence of well-developed collaterals to occluded coronary artery from the noninfarct vessel and its extent were independently associated with reduced infarct burden and improved myocardial salvage. Our results help explain why MI patients with well-developed collateralization have reduced mortality and morbidity. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Magnetic Field-Vector Measurements in Quiescent Prominences via the Hanle Effect: Analysis of Prominences Observed at Pic-Du-Midi and at Sacramento Peak

    Science.gov (United States)

    Bommier, V.; Leroy, J. L.; Sahal-Brechot, S.

    1985-01-01

    The Hanle effect method for magnetic field vector diagnostics has now provided results on the magnetic field strength and direction in quiescent prominences, from linear polarization measurements in the He I E sub 3 line, performed at the Pic-du-Midi and at Sacramento Peak. However, there is an inescapable ambiguity in the field vector determination: each polarization measurement provides two field vector solutions symmetrical with respect to the line-of-sight. A statistical analysis capable of solving this ambiguity was applied to the large sample of prominences observed at the Pic-du-Midi (Leroy, et al., 1984); the same method of analysis applied to the prominences observed at Sacramento Peak (Athay, et al., 1983) provides results in agreement on the most probable magnetic structure of prominences; these results are detailed. The statistical results were confirmed on favorable individual cases: for 15 prominences observed at Pic-du-Midi, the two-field vectors are pointing on the same side of the prominence, and the alpha angles are large enough with respect to the measurements and interpretation inaccuracies, so that the field polarity is derived without any ambiguity.

  12. Clinical study of the hypothesis of “endogenous collateral wind” on ...

    African Journals Online (AJOL)

    This study was to propose the hypothesis of “endogenous collateral wind” based on the patho-mechanism of thrombogenesis complicated by ruptured plaque on ACS, and the theory of traditional Chinese medicine. Materials and Methods: Through successful coronary angiography (CAG), and intravascular ultrasound ...

  13. Dynamic knee alignment and collateral knee laxity and its variations in normal humans

    Directory of Open Access Journals (Sweden)

    Kamal eDeep

    2015-11-01

    Full Text Available Alignment of normal, arthritic and replaced human knees is a much debated subject as is the collateral ligamentous laxity. Traditional quantitative values have been challenged. Methods used to measure these are also not without flaws. Authors review the recent literature and a novel method of measurement of these values has been included. This method includes use of computer navigation technique in clinic setting for assessment of the normal or affected knee before the surgery. Computer navigation has been known for achievement of alignment accuracy during knee surgery. Now its use in clinic setting has added to the inventory of measurement methods. Authors dispel the common myth of straight mechanical axis in normal knees and also look at quantification of amount of collateral knee laxity. Based on the scientific studies it has been shown that the mean alignment is in varus in normal knees. It changes from lying non weight bearing position to standing weight bearing position in both coronal and the sagittal planes. It also varies with gender and race. The collateral laxity is also different for males and females. Further studies are needed to define the ideal alignment and collateral laxity which the surgeon should aim for individual knees.

  14. Collateral sensitivity to cisplatin in KB-8-5-11 drug-resistant cancer cells.

    LENUS (Irish Health Repository)

    Doherty, Ben

    2014-01-01

    KB-8-5-11 cells are a drug-resistant cervical cell model that overexpresses ABCB1 (P-glycoprotein). KB-8-5-11 has become sensitive to non-ABCB1 substrate cisplatin. Understanding the mechanism of collateral sensitivity to cisplatin may lead to biomarker discovery for platinum sensitivity in patients with cancer.

  15. CT portal venography manifestations of portal collateral circulation in patients with portal hypertension due to cirrhosis

    International Nuclear Information System (INIS)

    Ni Ming; Lv Weifu; Deng Kexue

    2009-01-01

    Objective: To analyze CT portal venography (CTPV) manifestations of portal collateral circulation in patients with cirrhosis by using a 16-detector row spiral CT scanner. Methods: CTPV was performed in 36 patients with portal hypertension due to cirrhosis, the diagnosis was proved by clinical data, hepatic function findings and imaging signs. By using post-processing reconstruction technique, 3D images of portal venous system and portal collateral circulation were obtained. Results: CTPV images displayed the portal venous system and its collateral circulation stereoscopically. Of 36 patients, left gastric varices were seen in 29(80.6%), lower esophageal varices in 18(50.0%), short gastric or posterior gastric varices in 15(41.7%), paraesophageal varices in 9(25.0%), gastro-renal or splenorenal shunts in 8(22.2%), spongelike transformation of portal vein in 7(19.4%), paraumbilical and abdominal wall varices in 6(16.7%), congenital cavernous in 6(16.7%) and paravertebral venous shunts in 4(11.1%). Conclusion: CTPV can well display the site, extent and severity of the portal collateral circulation in patients with portal hypertension due to cirrhosis,which is of great clinical importance for judging the patient's condition, for selecting therapeutic protocols and for estimating prognosis. (authors)

  16. 7 CFR 1980.443 - Collateral, personal and corporate guarantees and other requirements.

    Science.gov (United States)

    2010-01-01

    ... the concurrence of FmHA or its successor agency under Public Law 103-354. (b) Personal and corporate... 7 Agriculture 14 2010-01-01 2009-01-01 true Collateral, personal and corporate guarantees and... (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM...

  17. 14 CFR 1261.410 - Suspension or revocation of license or eligibility; liquidation of collateral.

    Science.gov (United States)

    2010-01-01

    ... United States Arising Out of the Activities of the National Aeronautics and Space Administration (NASA... debtor fails to pay its debts to the Government within a reasonable time. The failure of any surety to... interested agencies. (b) If NASA is holding security or collateral which may be liquidated and the proceeds...

  18. Collateral Damage Related to Rape and Interpersonal Violence in Higher Education

    Science.gov (United States)

    Jones, Dan L.

    2014-01-01

    Collegiate communities are often faced with difficult situations from sexual assault, rape, and other forms of interpersonal violence. These events are not only tragic or traumatic for the individuals involved but also have ripple effects and create collateral damage within the campus community. Many universities are instituting bystander training…

  19. Lateral collateral ligament avulsion of the humeroradial joint in a horse

    International Nuclear Information System (INIS)

    Chopin, J.B.; Wright, J.D.; Melville, L.; Robinson, W.F.

    1997-01-01

    This report describes traumatic avulsion of the lateral collateral ligament of the humeroradial joint in a horse. The history and diagnostic procedures are included with relevant radiographs and ultrasonographs. The poor prognosis associated with this injury is due to degenerative joint disease

  20. Supplemental Transcatheter Arterial Chemoembolization Through a Collateral Omental Artery: Treatment for Hepatocellular Carcinoma

    International Nuclear Information System (INIS)

    Won, Jong Yun; Lee, Do Yun; Lee, Jong Tae; Park, Sung Il; Kim, Myeong-Jin; Yoo, Hyung Sik; Suh, Sang-Hyun; Park, Sang Joon

    2003-01-01

    Purpose: To evaluate the therapeutic efficacy and safety of supplemental transcatheter arterialchemoembolization (TACE) through the extrahepatic collateral omentalartery (OA) for the treatment of hepatocellular carcinoma (HCC). Methods: We studied 21 patients with extrahepatic collaterals of the OA, among 1,512 patients with HCC who had undergone angiography. HCCs supplied by collateral OAs were located at: segment IV in seven, segment V in five, segment III in three, segment VI in three and segment VIII in three patients (Couinaud classification of segments). On preoperative CT scans, every HCC was abutting the liver surface. Adjacent omental infiltration or engorgement was noted in 11 patients. Celiac and hepatic arteriograms showed hypertrophy of the feeding OA in all patients. TACE of the OA was performed in 19 patients with an emulsion of iodized oil and doxorubicin hydrochloride.Embolization with gelatin sponge particles was added in five patients. Results: Collaterals of the OA to the HCC were found on the first to seventeenth sessions of TACE. On follow-up CT scans, five patients showed complete uptake of iodized oil in the tumor. Partial uptake of iodized oil was noted in 13 patients and no uptake in one patient. There was no serious complication that related to the omental embolization, such as omental or bowel ischemia. The cumulative survival rates from the time of the TACE of the OA were 81% at 6 months and 68% at 12 months. Conclusion: TACE of the OA is safe and has a potential therapeutic effect in the treatment of HCC

  1. Collateral ligament reconstruction of the chronic thumb injury with bio-tenodesis screw fixation

    DEFF Research Database (Denmark)

    Gvozdenovic, Robert; Boeckstyns, Michel

    2014-01-01

    We describe a new technique for the reconstruction of chronic lesions of the collateral ligaments of the metacarpophalangeal ligaments of the thumb, using a Bio-Tenodesis screw for the fixation of a tendon graft in a triangular manner with proximal apex and allowing early mobilization, starting 2...

  2. Can Collateral Behavior Account for Transitions in the Stimulus Control of Speech?

    Science.gov (United States)

    Palmer, David C.

    2017-01-01

    The task of extending Skinner's (1957) interpretation of verbal behavior includes accounting for the moment-to-moment changes in stimulus control as one speaks. A consideration of the behavior of the reader reminds us of the continuous evocative effect of verbal stimuli on readers, listeners, and speakers. Collateral discriminative responses to…

  3. PRINSIP 6C (CHARACTER, CAPACITY, CAPITAL, CONDITION OF ECONOMY, COLLATERAL DAN CONSTRAINT DALAM WIRAUSAHA MAHASISWA

    Directory of Open Access Journals (Sweden)

    Henny Sri Astuty

    2015-04-01

    Full Text Available Abstrak: Prinsip 6C (Character, Capacity, Capital, Condition of Economy, Collateral dan Constraint dalam Wirausaha Mahasiswa. Kegiatan wirausaha yang sekarang banyak dilakukan oleh mahasiswa memiliki sisi positif maupun negatif, dari yang berhasil kuliah dan wirausahanya hingga yang gagal semuanya. Untuk ini diperlukan pemahaman tentang prinsip enam C (character, capacity, capital, condition of economy, collateral and constraint yang akan membantu mahasiswa sebagai bekal dalam melakukan kegiatan usahanya. Banyak faktor yang diperoleh dalam prinsip ini yaitu aspek manajemen, pemasaran, produksi, dan keuangan. Kata Kunci: prinsip 6c, wirausaha, mahasiswa Abstract: 6C Principles (Character, Capacity, Capital, Condition of Economy, Collateral and Constraint in Entrepreneurial Students. Entrepreneurial activity that is widely performed by students has two different stories. Some of them are successful on the other hand, the rest of them are fail. Accordingly, it is required an understanding of the 6C principles of the six C (character, capacity, capital, condition of economy, collateral and constraints which will help the students as a preparation in conducting their business activities. Many factors obtained in this principle namely: management, marketing, production, and financial aspects. Keywords: 6C principles, entrepreneurs, students

  4. The range of adaptation by collateral vessels after femoral artery occlusion

    NARCIS (Netherlands)

    Eitenmüller, Inka; Volger, Oscar; Kluge, Alexander; Troidl, Kerstin; Barancik, Miroslav; Cai, Wei-Jun; Heil, Matthias; Pipp, Frederic; Fischer, Silvia; Horrevoets, Anton J. G.; Schmitz-Rixen, Thomas; Schaper, Wolfgang

    2006-01-01

    Natural adaptation to femoral artery occlusion in animals by collateral artery growth restores only approximately 35% of adenosine-recruitable maximal conductance (C(max)) probably because initially elevated fluid shear stress (FSS) quickly normalizes. We tested the hypothesis whether this deficit

  5. Contrast-Induced Nephropathy Is Less Common in Patients with Good Coronary Collateral Circulation.

    Science.gov (United States)

    Avci, Eyup; Yildirim, Tarik; Kadi, Hasan

    2017-10-01

    Contrast-induced nephropathy (CIN) is a typically reversible type of acute renal failure that develops after exposure to contrast agents; underlying endothelial dysfunction is thought to be an important risk factor for CIN. Although the mechanism of coronary collateral circulation (CCC) is not fully understood, a pivotal role of the endothelium has been reported in many studies. The aim of this study was to investigate whether there is a relationship between CCC and CIN. Patients with at least one occluded major coronary artery and blood creatinine analyses performed before and on the second day after angiography were included in the study. CIN was defined as a 25% or greater elevation of creatinine on the second day after exposure to the contrast agent. Collateral grading was performed according to the Rentrop classification. Patients were grouped according to whether they developed CIN or not, i.e., CIN(-) and CIN(+) group. A total of 214 patients who met the inclusion criteria were included in the study. CIN was diagnosed in 43 patients (20.1%) in the study population. Good CCC was identified in 112 patients (65.5%) in the CIN(-) group, whereas it was identified in 13 patients (30.2%) in the CIN(+) group. In the CIN(-) group, good CCC was significantly more frequent ( p Good collateral circulation was associated with a lower frequency of CIN, and poor collateral circulation was an independent predictor of CIN.

  6. Credit frictions, collateral and the cyclical behavior of the finance premium

    NARCIS (Netherlands)

    Agénor, P.-R.; Bratsiotis, G.; Pfajfar, D.

    This paper examines the behavior of the finance premium after technology and monetary shocks in a dynamic stochastic general equilibrium (DSGE) model where borrowers use a fraction of their production (output) as collateral. We show that this simple framework is capable of producing a

  7. BADAL: A Culture of Revenge, The Impact of Collateral Damage on Taliban Insurgency

    Science.gov (United States)

    2008-03-01

    residents’ (on both side of the border) point of view, Durand Line is a virtual border and is trespassed across freely, without any legal document or... Positiv e Perception of Coalition Behav ior Kill Rate ~ Attrition Rate ~ Attritions Rate 2 ~ Collateral Damage Civ ilian Deaths ~ Death Rate Madrassa

  8. Protection of third parties by collateral clauses of plan approvals or licenses

    International Nuclear Information System (INIS)

    Badura, P.

    1989-01-01

    This contribution discusses the regulatory functions of collateral clauses of plan approvals or licences, the legal protection of the constitutional and other rights of third parties in connection with the licensing of installations or similar projects, infringements of such rights and means of defence, and protection of neighbours under public law against noise. (RST) [de

  9. Collateral blood supply to the myocardium at risk in human myocardial infarction: a quantitative postmortem assessment

    NARCIS (Netherlands)

    Piek, J. J.; Becker, A. E.

    1988-01-01

    The relation between the type and size of myocardial infarcts and collateral development was studied in postmortem human hearts with a new approach that allows quantification of vascular beds. The coronary arteries were perfused with radioactive microspheres and were visualized by injecting a

  10. Comparison of four different collateral scores in acute ischemic stroke by CT angiography.

    Science.gov (United States)

    Seker, Fatih; Potreck, Arne; Möhlenbruch, Markus; Bendszus, Martin; Pham, Mirko

    2016-11-01

    Multiple scores have been described for the assessment of collateralization in acute ischemic stroke. Currently, there is no gold standard for collateral assessment by CT angiography (CTA). This study compared four frequently used collateral scores with regard to their correlation with early infarct core and mismatch ratio. 30 consecutive patients with acute occlusion of the M1 segment or terminal carotid artery were reviewed retrospectively. Collaterals were assessed using dynamic and also single-phase CTA according to grading systems by the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR), Alberta Stroke Program Early CT Score (ASPECTS) (on collaterals), Christoforidis et al and Miteff et al. The Christoforidis and ASITN/SIR scores, which were initially designed for conventional angiography, were adapted to be applicable to CTA. The scores were compared with respect to early infarct core and mismatch ratio in perfusion CT estimated by RAPID software using Spearman correlation. ASITN/SIR and ASPECTS collateral scores showed good correlation with early infarct core (rho=-0.696, p<0.001 and rho=-0.677, p<0.001) and mismatch ratio (rho=0.609, p<0.001 and rho=0.581, p<0.001). In contrast, the Christoforidis and Miteff scores correlated less well with infarct core (rho=0.245, p=0.191 and rho=-0.272, p=0.145, respectively) and mismatch ratio (rho=-0.329, p=0.075 and rho=0.279, p=0.135, respectively). ASPECTS and ASITN/SIR showed excellent cross-correlation (rho=0.901, p<0.001). Compared with the Christoforidis and Miteff scores, the modified ASITN/SIR and ASPECTS collateral scores showed consistently higher correlation with the extent of early infarct core and mismatch volume. This is probably because these scores evaluate the extent and delay of vascular enhancement in the affected territory rather than the backflow of contrast medium to the occlusion. Published by the BMJ Publishing Group Limited. For

  11. Evaluation of portosystemic collaterals by MDCT-MPR imaging for management of hemorrhagic esophageal varices

    International Nuclear Information System (INIS)

    Kodama, Hideaki; Aikata, Hiroshi; Takaki, Shintaro; Azakami, Takahiro; Katamura, Yoshio; Kawaoka, Tomokazu; Hiramatsu, Akira; Waki, Koji; Imamura, Michio; Kawakami, Yoshiiku; Takahashi, Shoichi; Toyota, Naoyuki; Ito, Katsuhide; Chayama, Kazuaki

    2010-01-01

    Objective: To study the correlation between changes in portosystemic collaterals, evaluated by multidetector-row computed tomography imaging using multiplanar reconstruction (MDCT-MPR), and prognosis in patients with hemorrhagic esophageal varices (EV) after endoscopic treatment. Methods: Forty-nine patients with primary hemostasis for variceal bleeding received radical endoscopic treatment: endoscopic injection sclerotherapy (EIS) or endoscopic variceal ligation (EVL). Patients were classified according to the rate of reduction in feeding vessel diameter on MDCT-MPR images, into the narrowing (n = 24) and no-change (n = 25) groups. We evaluated changes in portosystemic collaterals by MDCT-MPR before and after treatment, and determined rebleeding and survival rates. Results: The left gastric and paraesophageal (PEV) veins were recognized as portosystemic collaterals in 100 and 80%, respectively, of patients with EV on MDCT-MPR images. The rebleeding rates at 1, 2, 3, and 5 years after endoscopic treatment were 10, 15, 23, and 23%, respectively, for the narrowing group, and 17, 24, 35, and 67%, respectively, for the no-change group (P = 0.068). Among no-change group, the rebleeding rate in patients with large PEV was significantly lower than that with small PEV (P = 0.027). The rebleeding rate in patients with small PEV of the no-change group was significantly higher than that in the narrowing group (P = 0.018). There was no significant difference in rebleeding rates between the no-change group with a large PEV and narrowing group (P = 0.435). Conclusion: Changes in portosystemic collaterals evaluated by MDCT-MPR imaging correlate with rebleeding rate. Evaluation of portosystemic collaterals in this manner would provide useful information for the management of hemorrhagic EV.

  12. Multidetector Computed Tomography Assessment in Biliary Atresia for the Diagnosis of Portosystemic Collaterals before Liver Transplant

    International Nuclear Information System (INIS)

    Cadavid A, Lina; Barber, Ignasi; Bueno, Javier

    2011-01-01

    Introduction: Chronic liver disease increases portal vein pressure and modifies splanchnic circulation. This is particularly significant in infants with biliary atresia. Large collaterals steal portal flow and increase the risk of post transplant portal vein thrombosis. Objective: to describe different types of portosystemic collaterals prior to liver transplantation with low-dose multidetector CT (MDCT) in patients with biliary atresia. Material and methods: 13 patients with severe liver dysfunction due to biliary atresia underwent low-dose 64-MDCT before liver transplantation (effective tube current ranged from 20 to 120 mAs according to weight, with a kilo voltage of 80-120 for all CT). Hepatic arterial and portal venous phases were performed after IV contrast administration [1.5-2 ml/kg]. The mean age of the study group was1 year (range, 4 months to 3.6 years). Two radiologists reviewed the CT images to determine the grade and types of the portosystemic collaterals. Results: A total of 16 CT scans were obtained.the most common portosystemic collaterals found were esophageal (11), gastric submucosal (8), gastric adventitial (7, splenic (7), hemorrhoidal (10), mesenteric [dilated or tortuous branches of the inferior mesenteric vein (8)], retroperitoneal varices [gastro renal shunt (10), splenorenal shunt (4)] and dilated or tortuous left gastric vein (13). Conclusion: MDCT provides important information on venous system patency, presence of varices, and location of venous shunts in pediatric patients with biliary atresia going to liver transplant. in addition, it is critical to detect collaterals that are not evident on ultrasound in order to avoid the steal phenomenon that may lead to portal vein thrombosis and graft failure.

  13. Impact of collateral circulation status on favorable outcomes in thrombolysis treatment: A systematic review and meta-analysis.

    Science.gov (United States)

    Wufuer, Alimu; Wubuli, Atikaimu; Mijiti, Peierdun; Zhou, Jun; Tuerxun, Shabier; Cai, Jian; Ma, Jianhua; Zhang, Xiaoning

    2018-01-01

    Collateral circulation affects the prognosis of patients with acute ischemic stroke (AIS) treated by thrombolysis. The present study performed a systematic assessment of the impact of the collateral circulation status on the outcomes of patients receiving thrombolysis treatment. Relevant full-text articles from the Cochrane Library, Ovid, Medline, Embase and PubMed databases published from January 1, 2000 to November 1, 2016 were retrieved. The quality of the studies was assessed and data were extracted by 2 independent investigators. The random-effects model was used to estimate the impact of good vs. poor collateral circulation, as well as baseline characteristics, on the outcome within the series presented as risk ratios. Subgroup analyses explored the potential factors that may interfere with the effects of the collateral circulation status on the outcome. A total of 29 studies comprising 4,053 patients were included in the present meta-analysis. A good collateral circulation status was revealed to have a beneficial effect on favorable functional outcome (modified Rankin scale, 0-3 at 3-6 months; Pcollateral circulation. Good collateral circulation was also associated with a lower rate of symptomatic intracranial hemorrhage (Pcollateral circulation was demonstrated to have a favorable prognostic value regarding the outcome for patients with AIS receiving thrombolysis treatment. Assessment of collateral circulation and penumbra area during pre-treatment imaging within an appropriate time-window prior to thrombolytic therapy will therefore improve the identification of AIS patients who may benefit from thrombolysis treatment.

  14. CRITICAL HEIGHT FOR THE DESTABILIZATION OF SOLAR PROMINENCES: STATISTICAL RESULTS FROM STEREO OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Liu Kai; Wang Yuming; Wang Shui; Shen Chenglong, E-mail: ymwang@ustc.edu.cn [CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2012-01-10

    At which height is a prominence inclined to be unstable, or where is the most probable critical height for the prominence destabilization? This question was statistically studied based on 362 solar limb prominences well recognized by Solar Limb Prominence Catcher and Tracker from 2007 April to the end of 2009. We found that there are about 71% disrupted prominences (DPs), among which about 42% of them did not erupt successfully and about 89% of them experienced a sudden destabilization process. After a comprehensive analysis of the DPs, we discovered the following: (1) Most DPs become unstable at a height of 0.06-0.14 R{sub Sun} from the solar surface, and there are two most probable critical heights at which a prominence is very likely to become unstable, the first one is 0.13 R{sub Sun} and the second one is 0.19 R{sub Sun }. (2) An upper limit for the erupting velocity of eruptive prominences (EPs) exists, which decreases following a power law with increasing height and mass; accordingly, the kinetic energy of EPs has an upper limit too, which decreases as the critical height increases. (3) Stable prominences are generally longer and heavier than DPs, and not higher than 0.4 R{sub Sun }. (4) About 62% of the EPs were associated with coronal mass ejections (CMEs); but there is no difference in apparent properties between EPs associated with CMEs and those that are not.

  15. CRITICAL HEIGHT FOR THE DESTABILIZATION OF SOLAR PROMINENCES: STATISTICAL RESULTS FROM STEREO OBSERVATIONS

    International Nuclear Information System (INIS)

    Liu Kai; Wang Yuming; Wang Shui; Shen Chenglong

    2012-01-01

    At which height is a prominence inclined to be unstable, or where is the most probable critical height for the prominence destabilization? This question was statistically studied based on 362 solar limb prominences well recognized by Solar Limb Prominence Catcher and Tracker from 2007 April to the end of 2009. We found that there are about 71% disrupted prominences (DPs), among which about 42% of them did not erupt successfully and about 89% of them experienced a sudden destabilization process. After a comprehensive analysis of the DPs, we discovered the following: (1) Most DPs become unstable at a height of 0.06-0.14 R ☉ from the solar surface, and there are two most probable critical heights at which a prominence is very likely to become unstable, the first one is 0.13 R ☉ and the second one is 0.19 R ☉ . (2) An upper limit for the erupting velocity of eruptive prominences (EPs) exists, which decreases following a power law with increasing height and mass; accordingly, the kinetic energy of EPs has an upper limit too, which decreases as the critical height increases. (3) Stable prominences are generally longer and heavier than DPs, and not higher than 0.4 R ☉ . (4) About 62% of the EPs were associated with coronal mass ejections (CMEs); but there is no difference in apparent properties between EPs associated with CMEs and those that are not.

  16. Tic Tac TOE: Effects of Predictability and Importance on Acoustic Prominence in Language Production

    Science.gov (United States)

    Watson, Duane G.; Arnold, Jennifer E.; Tanenhaus, Michael K.

    2008-01-01

    Importance and predictability each have been argued to contribute to acoustic prominence. To investigate whether these factors are independent or two aspects of the same phenomenon, naive participants played a verbal variant of Tic Tac Toe. Both importance and predictability contributed independently to the acoustic prominence of a word, but in…

  17. Heating of an Erupting Prominence Associated with a Solar Coronal Mass Ejection on 2012 January 27

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin-Yi; Moon, Yong-Jae; Kim, Kap-Sung [Department of Astronomy and Space Science, Kyung Hee University, Yongin-si, Gyeonggi-do, 17104 (Korea, Republic of); Raymond, John C.; Reeves, Katharine K. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

    2017-07-20

    We investigate the heating of an erupting prominence and loops associated with a coronal mass ejection and X-class flare. The prominence is seen as absorption in EUV at the beginning of its eruption. Later, the prominence changes to emission, which indicates heating of the erupting plasma. We find the densities of the erupting prominence using the absorption properties of hydrogen and helium in different passbands. We estimate the temperatures and densities of the erupting prominence and loops seen as emission features using the differential emission measure method, which uses both EUV and X-ray observations from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory and the X-ray Telescope on board Hinode . We consider synthetic spectra using both photospheric and coronal abundances in these calculations. We verify the methods for the estimation of temperatures and densities for the erupting plasmas. Then, we estimate the thermal, kinetic, radiative loss, thermal conduction, and heating energies of the erupting prominence and loops. We find that the heating of the erupting prominence and loop occurs strongly at early times in the eruption. This event shows a writhing motion of the erupting prominence, which may indicate a hot flux rope heated by thermal energy release during magnetic reconnection.

  18. 77 FR 3779 - Guidance for Industry on Product Name Placement, Size, and Prominence in Advertising and...

    Science.gov (United States)

    2012-01-25

    ... Advertising and Promotional Labeling; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice... entitled ``Product Name Placement, Size, and Prominence in Advertising and Promotional Labeling.'' The..., prominence, and frequency in promotional labeling and advertising for prescription human and animal drugs and...

  19. Physics of Solar Prominences: I-Spectral Diagnostics and Non-LTE Modelling

    Science.gov (United States)

    Labrosse, N.; Heinzel, P.; Vial, J.-C,; Kucera, T.; Parenti, S.; Gunar, S.; Schmieder, B.; Kilper, G.

    2010-01-01

    This review paper outlines background information and covers recent advances made via the analysis of spectra and images of prominence plasma and the increased sophistication of non-LTE (i.e. when there is a departure from Local Thermodynamic Equilibrium) radiative transfer models. We first describe the spectral inversion techniques that have been used to infer the plasma parameters important for the general properties of the prominence plasma in both its cool core and the hotter prominence-corona transition region. We also review studies devoted to the observation of bulk motions of the prominence plasma and to the determination of prominence mass. However, a simple inversion of spectroscopic data usually fails when the lines become optically thick at certain wavelengths. Therefore, complex

  20. Fabrication of micro-prominences on PTFE surface using proton beam writing

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, Akane, E-mail: ogawa.akane@jaea.go.jp [Department of Advanced Radiation Technology, Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki-Machi, Takasaki, Gunma 370-1292 (Japan); Satoh, Takahiro; Koka, Masashi [Department of Advanced Radiation Technology, Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki-Machi, Takasaki, Gunma 370-1292 (Japan); Kobayashi, Tomohiro [Advanced Science Institute, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 350-0198 (Japan); Kamiya, Tomihiro [Department of Advanced Radiation Technology, Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki-Machi, Takasaki, Gunma 370-1292 (Japan)

    2013-07-01

    Polytetrafluoroethylene (PTFE) is a typical fluoropolymer and it has several desirable technological properties such as electrical insulation, solid lubrication etc. However, the conventional microstructuring methods have not been well applied to PTFE due to its chemical inertness. Some effective micromachining using synchrotron radiation or ion beam irradiation has been reported. In this study, we create micro-prominences by raising the original surface using proton beam writing (PBW) without chemical etching. A conical prominence was formed by spiral drawing from the center with a 3 MeV proton beam. The body was porous, and the bulk PTFE below the prominence changed to fragmented structures. With decreasing writing speed, the prominence became taller but the height peaked. The prominence gradually reduced in size after the speed reached the optimum value. We expect that these porous projections with high aspect ratio will be versatile in medical fields and microelectromechanical systems (MEMS) technology.

  1. Modeling of prominence threads in magnetic fields: Levitation by incompressible MHD waves

    Science.gov (United States)

    Pécseli, Hans; Engvold, OddbjØrn

    2000-05-01

    The nature of thin, highly inclined threads observed in quiescent prominences has puzzled solar physicists for a long time. When assuming that the threads represent truly inclined magnetic fields, the supporting mechanism of prominence plasma against gravity has remained an open issue. This paper examines the levitation of prominence plasma exerted by weakly damped MHD waves in nearly vertical magnetic flux tubes. It is shown that the wave damping, and resulting `radiation pressure', caused predominantly by ion-neutral collisions in the `cold' prominence plasma, may balance the acceleration of gravity provided the oscillation frequency is ω~ 2 rad s^-1 (f~0.5 Hz). Such short wave periods may be the result of small-scale magnetic reconnections in the highly fragmentary magnetic field of quiescent prominences. In the proposed model, the wave induced levitation acts predominantly on plasma - neutral gas mixtures.

  2. Intra-renal localised reno-renal collaterals in the dog after tying of the main renal artery

    International Nuclear Information System (INIS)

    Rosenbusch, G.; Vincent, J.; Douveren, W. van; Sktonicki, S.; Arts, T.H.M.; Katholieke Univ. Nijmegen; Katholieke Univ. Nijmegen

    1984-01-01

    In 7 kidneys of 6 dogs one of the main stem of the renal artery was ligated. The development of the renorenal collaterals could be followed in 5, as two dogs died after the operation. In all cases intrarenal collaterals could be demonstrated, even in the postoperative dead dogs. The vessels responsible for the collateral circulation are preformed interarterial anastomoses, belonging to the extraglomerular arterial system. From the results of these and former experimental studies it can be concluded, that the renal artery of the dog when entering the renal sinus cannot be regarded as an anatomic, but at most as a functional end artery. (orig.) [de

  3. Intra-renal localised reno-renal collaterals in the dog after tying of the main renal artery

    Energy Technology Data Exchange (ETDEWEB)

    Rosenbusch, G.; Vincent, J.; Douveren, W. van; Sktonicki, S.; Arts, T.H.M.

    1984-01-01

    In 7 kidneys of 6 dogs one of the main stem of the renal artery was ligated. The development of the renorenal collaterals could be followed in 5, as two dogs died after the operation. In all cases intrarenal collaterals could be demonstrated, even in the postoperative dead dogs. The vessels responsible for the collateral circulation are preformed interarterial anastomoses, belonging to the extraglomerular arterial system. From the results of these and former experimental studies it can be concluded, that the renal artery of the dog when entering the renal sinus cannot be regarded as an anatomic, but at most as a functional end artery.

  4. Superior vena cava syndrome associated with right-to left shunt through systemic-to-pulmonary venous collaterals

    International Nuclear Information System (INIS)

    Juan, Yu Hsiang; Saboo, Sachin S.; Anand, Vishal; Chatzizisis, Yiannis S.; Steigner, Michael L.; Lin, Yu Ching

    2014-01-01

    Superior vena cava (SVC) obstruction is associated with the gradual development of venous collaterals. We present a rare form of systemic-to-pulmonary subpleural collateral pathway that developed in the bridging subpleural pulmonary veins in a 54-year-old woman with complete SVC obstruction. This uncommon collateral pathway represents a rare form of acquired right-to-left shunt due to previous pleural adhesions with an increased risk of stroke due to right-to-left venous shunting, which requires lifelong anticoagulation.

  5. Management of Medial Collateral Ligament Injury During Primary Total Knee Arthroplasty: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Paul Della Torre, MD

    2014-07-01

    Full Text Available Medial collateral ligament injury during primary total knee arthroplasty is a recognised complication potentially resulting in valgus instability, suboptimal patient outcomes and a higher rate of revision or reoperation. Options for management include primary repair with or without augmentation, reconstruction or immediate conversion to prosthesis with greater constraint, in conjunction with various postoperative rehabilitation protocols. Inconsistent recommendations throughout the orthopaedic literature have made the approach to managing this complication problematic. The objective of this study was to review the available literature to date comparing intraoperative and postoperative management options for primary total knee arthroplasty complicated by recognised injury to the medial collateral ligament. This systematic literature review was prospectively registered with PROSPERO (#CRD42014008866 and performed in accordance with PRISMA guidelines including a PRISMA flow diagram. Five articles satisfied the inclusion criteria. Each was a retrospective, observational cohort or case series with small numbers reported, inconsistent methodology and incompletely reported outcomes. Four of the five studies managing medial collateral ligament injury during total knee arthroplasty (47/84 patients with direct repair with or without autograft augmentation reported good outcomes with no revision or reoperation required for symptomatic instability over a follow-up period of 16 months to almost 8 years. The fifth study with a follow-up to 10 years and a high rate of conversion to unlinked semi constrained total knee arthroplasty implant (30/37 patients reported a greater incidence of revision due to instability, in patients in whom the medial collateral ligament injury was directly repaired without added constraint. Overall balance of evidence is in favour of satisfactory outcomes without symptomatic instability following direct repair with or without

  6. TORNADO-LIKE EVOLUTION OF A KINK-UNSTABLE SOLAR PROMINENCE

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wensi; Liu, Rui; Wang, Yuming, E-mail: rliu@ustc.edu.cn [CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei 230026 (China)

    2017-01-01

    We report on the tornado-like evolution of a quiescent prominence on 2014 November 1. The eastern section of the prominence first rose slowly, transforming into an arch-shaped structure as high as ∼150 Mm above the limb; the arch then writhed moderately in a left-handed sense, while the original dark prominence material emitted in the Fe ix 171 Å passband, and a braided structure appeared at the eastern edge of the warped arch. The unraveling of the braided structure was associated with a transient brightening in the EUV and apparently contributed to the formation of a curtain-like structure (CLS). The CLS consisted of myriad thread-like loops rotating counterclockwise about the vertical if viewed from above. Heated prominence material was observed to slide along these loops and land outside the filament channel. The tornado eventually disintegrated and the remaining material flew along a left-handed helical path constituting approximately a full turn, as corroborated through stereoscopic reconstruction, into the cavity of the stable, western section of the prominence. We suggest that the tornado-like evolution of the prominence was governed by the helical kink instability, and that the CLS formed through magnetic reconnections between the prominence field and the overlying coronal field.

  7. Prominence-corona interface compared with the chromosphere-corona transition region

    Energy Technology Data Exchange (ETDEWEB)

    Orrall, F Q; Schmahl, E J [Harvard Coll. Observatory, Cambridge, Mass. (USA)

    1976-11-01

    The intensities of 52 EUV emission lines from each of 9 hedgerow prominences observed at the limb with the Harvard experiment on ATM-Skylab have been compared with intensities from the interior of network cells at the center of the disk, in order to compare the prominence-corona (P-C) interface with the chromosphere-corona (C-C) transition region. The intensity ratio Isub(cell)/Isub(prominence) for each line varies systematically (in all of the prominences observed), with the temperature of formation of the line as approximately Tsup(-0.6). The density sensitive C III (formed at T approximately 9x10/sup 4/ K) line ratio Isub(lambda1175)/Isub(lambda977) implies an average density 1.3x10/sup 9/ electrons cm/sup -3/ in the P-C interface and approximately 4 times this value in the C-C transition of the cells. The total optical thickness at the head of the Lyman continuum is < approximately 10 in most of the prominences studied; in two of the prominences, however, the possibility that tau/sub 0/ is large cannot be rejected. Methods of analysis of these EUV data are developed assuming both a resolved and an unresolved internal prominence structure. Although the systematic differences between the P-C interface and the C-C transition are stressed, the similarities are probably more remarkable and may be a result of fine structure in the C-C transition.

  8. Motions in Prominence Barbs as observed by Hinode/SOT and IRIS

    Science.gov (United States)

    Kucera, Therese A.; Ofman, Leon; Tarbell, Theodore D.

    2016-05-01

    We discuss observations of prominence barb dynamics as observed by Hinode/SOT and IRIS. Prominence barbs extend outwards to the side of the main prominence spine and downwards towards the chromosphere. Their properties, including the structure of their magnetic field and the nature of the motions observed in them are a subject of current debate. We use a combination of high cadence, high resolution imaging, H-alpha Doppler, and Mg II line profile data to analyze and understand waves and flows in barbs and discuss their ramifications in terms of a model of the barb magnetic field as collection of dipped field lines.

  9. Case of idiopathic portalhypertension. Comparison of pre- and post-operative CT scan findings of collateral circulation

    Energy Technology Data Exchange (ETDEWEB)

    Serizawa, K; Yajima, Y; Onodera, H; Hirata, T; Sugawara, H [Tohoku Univ., Sendai (Japan). School of Medicine

    1982-02-01

    A 40-year-old man was referred to our clinic for esophageal varices. Histological examination of the liver biopsy samples revealed no sign of liver cirrhosis. Celiac angiography and ultrasound showed no obstruction of portal vein. A diagnosis of idiopathic portalhypertension was established. Splenomegaly and collateral circulation from spleen to left retroperitoneum were shown on CT scan and confirmed by surgical operation. CT scan following operation showed no collateral circulation.

  10. FLAIR vascular hyperintensities and dynamic 4D angiograms for the estimation of collateral blood flow in posterior circulation occlusion

    International Nuclear Information System (INIS)

    Foerster, Alex; Wenz, Holger; Kerl, Hans Ulrich; Al-Zghloul, Mansour; Habich, Sonia; Groden, Christoph

    2014-01-01

    The objectives of this paper are to assess collateral blood flow in posterior circulation occlusion by MRI-based approaches (fluid-attenuated inversion recovery (FLAIR) vascular hyperintensities (FVHs), collateralization on dynamic 4D angiograms) and investigate its relation to ischemic lesion size and growth. In 28 patients with posterior cerebral artery (PCA) and 10 patients with basilar artery (BA) occlusion, MRI findings were analyzed, with emphasis on distal FVH and collateralization on dynamic 4D angiograms. In PCA occlusion, distal FVH was observed in 18/29 (62.1 %), in BA occlusion, in 8/10 (80 %) cases. Collateralization on dynamic 4D angiograms was graded 1 in 8 (27.6 %) patients, 2 in 1 (3.4 %) patient, 3 in 12 (41.4 %) patients, and 4 in 8 (27.6 %) patients with PCA occlusion and 0 in 1 (10 %) patient, 2 in 3 (30 %) patients, 3 in 1 (10 %) patient, and 4 in 5 (50 %) patients with BA occlusion. FVH grade showed neither correlation with initial or follow-up diffusion-weighted image (DWI) lesion size nor DWI-perfusion-weighted imaging (PWI) mismatch ratio. Collateralization on dynamic 4D angiograms correlated inversely with initial DWI lesion size and moderately with the DWI-(PWI) mismatch ratio. The combination of distal FVH and collateralization grade on dynamic 4D angiograms correlated inversely with initial as well as follow-up DWI lesion size and highly with the DWI-PWI mismatch ratio. In posterior circulation occlusion, FVH is a frequent finding, but its prognostic value is limited. Dynamic 4D angiograms are advantageous to examine and graduate collateral blood flow. The combination of both parameters results in an improved characterization of collateral blood flow and might have prognostic relevance. (orig.)

  11. [Collateral score based on CT perfusion can predict the prognosis of patients with anterior circulation ischemic stroke after thrombectomy].

    Science.gov (United States)

    Wang, Qingsong; Zhang, Sheng; Zhang, Meixia; Chen, Zhicai; Lou, Min

    2017-07-25

    To evaluate the value of collateral score based on CT perfusion (CTP-CS) in predicting the clinical outcome of patients with anterior circulation ischemic stroke after thrombectomy. Clinical data of acute ischemic stroke patients with anterior artery occlusion undergoing endovascular treatment in the Second Affiliated Hospital, Zhejiang University School of Medicine during October 2013 and October 2016 were retrospectively reviewed. Collateral scores were assessed based on CTP and digital subtraction angiography (DSA) images, respectively. And DSA-CS or CTP-CS 3-4 was defined as good collateral vessels. Good clinical outcome was defined as a modified Rankin Scale (mRS) ≤ 2 at 3 months after stroke. The binary logistic regression model was used to analyze the correlation between the collateral score and clinical outcome, and the receiver operating characteristic (ROC) curve was used to analyze the value of DSA-CS and CTP-CS in predicting the clinical outcome. Among 40 patients, 33 (82.5%) acquired recanalization and 16 (40.0%) got good outcome. Compared with poor outcome group, the collateral score (all P collateral vessels were higher in good outcome group (all P collateral vessels were independent factor of good outcome (CTP-CS: OR =48.404, 95% CI :1.373-1706.585, P Collateral scores based on CTP and DSA had good consistency ( κ =0.697, P <0.01), and ROC curve showed that the predictive value of CTP-CS and DSA-CS were comparable (both AUC=0.726, 95% CI :0.559-0.893, P <0.05). CTP-CS can predict the clinical outcome of patients with anterior circulation ischemic stroke after thrombectomy.

  12. Right to left shunt as a collateral circulation in a patient with superior vena cava syndrome: a case report

    International Nuclear Information System (INIS)

    Kim, Young Sun; Jeon, Seok Chol; Moon, Won Jin; Choi, Yo Won; Seo, Heung Suk; Hahm, Chang Kok; Park, Choong Ki

    1999-01-01

    In patients with superior vena cava syndrome, the form of the collateral circulatory system which communicates with the inferior vena cava via various systemic veins usually varics. We found an instance of unusual collateral circulation : direct communication between the systemic and pulmonary vein in a woman with superior vena cava syndrome caused by metastatic lymph node enlargement. In this report, we describe the CT and radionuclide venographic findings

  13. Dll4-Notch signaling determines the formation of native arterial collateral networks and arterial function in mouse ischemia models.

    Science.gov (United States)

    Cristofaro, Brunella; Shi, Yu; Faria, Marcella; Suchting, Steven; Leroyer, Aurelie S; Trindade, Alexandre; Duarte, Antonio; Zovein, Ann C; Iruela-Arispe, M Luisa; Nih, Lina R; Kubis, Nathalie; Henrion, Daniel; Loufrani, Laurent; Todiras, Mihail; Schleifenbaum, Johanna; Gollasch, Maik; Zhuang, Zhen W; Simons, Michael; Eichmann, Anne; le Noble, Ferdinand

    2013-04-01

    Arteriogenesis requires growth of pre-existing arteriolar collateral networks and determines clinical outcome in arterial occlusive diseases. Factors responsible for the development of arteriolar collateral networks are poorly understood. The Notch ligand Delta-like 4 (Dll4) promotes arterial differentiation and restricts vessel branching. We hypothesized that Dll4 may act as a genetic determinant of collateral arterial networks and functional recovery in stroke and hind limb ischemia models in mice. Genetic loss- and gain-of-function approaches in mice showed that Dll4-Notch signaling restricts pial collateral artery formation by modulating arterial branching morphogenesis during embryogenesis. Adult Dll4(+/-) mice showed increased pial collateral numbers, but stroke volume upon middle cerebral artery occlusion was not reduced compared with wild-type littermates. Likewise, Dll4(+/-) mice showed reduced blood flow conductance after femoral artery occlusion, and, despite markedly increased angiogenesis, tissue ischemia was more severe. In peripheral arteries, loss of Dll4 adversely affected excitation-contraction coupling in arterial smooth muscle in response to vasopressor agents and arterial vessel wall adaption in response to increases in blood flow, collectively contributing to reduced flow reserve. We conclude that Dll4-Notch signaling modulates native collateral formation by acting on vascular branching morphogenesis during embryogenesis. Dll4 furthermore affects tissue perfusion by acting on arterial function and structure. Loss of Dll4 stimulates collateral formation and angiogenesis, but in the context of ischemic diseases such beneficial effects are overruled by adverse functional changes, demonstrating that ischemic recovery is not solely determined by collateral number but rather by vessel functionality.

  14. Revision with suture-tape augmentation after failed collateral ligament reconstruction for chronic interphalangeal instability of the hallux.

    Science.gov (United States)

    Cho, Byung-Ki; Park, Ji-Kang; Choi, Seung-Myung; SooHoo, Nelson F

    2017-12-01

    Chronic varus instability or recurrent subluxation following isolated interphalangeal dislocation of the hallux is a rare injury. No consensus has been reached regarding the best joint-salvage procedure for patients with the failed collateral ligament reconstruction using tendon graft. We report a case who achieved satisfactory clinical outcome through a modified surgical procedure (revision collateral ligament reconstruction augmented with suture-tape). Copyright © 2017 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  15. Dll4-Notch signaling determines the formation of native arterial collateral networks and arterial function in mouse ischemia models

    Science.gov (United States)

    Cristofaro, Brunella; Shi, Yu; Faria, Marcella; Suchting, Steven; Leroyer, Aurelie S.; Trindade, Alexandre; Duarte, Antonio; Zovein, Ann C.; Iruela-Arispe, M. Luisa; Nih, Lina R.; Kubis, Nathalie; Henrion, Daniel; Loufrani, Laurent; Todiras, Mihail; Schleifenbaum, Johanna; Gollasch, Maik; Zhuang, Zhen W.; Simons, Michael; Eichmann, Anne; le Noble, Ferdinand

    2013-01-01

    Arteriogenesis requires growth of pre-existing arteriolar collateral networks and determines clinical outcome in arterial occlusive diseases. Factors responsible for the development of arteriolar collateral networks are poorly understood. The Notch ligand Delta-like 4 (Dll4) promotes arterial differentiation and restricts vessel branching. We hypothesized that Dll4 may act as a genetic determinant of collateral arterial networks and functional recovery in stroke and hind limb ischemia models in mice. Genetic loss- and gain-of-function approaches in mice showed that Dll4-Notch signaling restricts pial collateral artery formation by modulating arterial branching morphogenesis during embryogenesis. Adult Dll4+/- mice showed increased pial collateral numbers, but stroke volume upon middle cerebral artery occlusion was not reduced compared with wild-type littermates. Likewise, Dll4+/- mice showed reduced blood flow conductance after femoral artery occlusion, and, despite markedly increased angiogenesis, tissue ischemia was more severe. In peripheral arteries, loss of Dll4 adversely affected excitation-contraction coupling in arterial smooth muscle in response to vasopressor agents and arterial vessel wall adaption in response to increases in blood flow, collectively contributing to reduced flow reserve. We conclude that Dll4-Notch signaling modulates native collateral formation by acting on vascular branching morphogenesis during embryogenesis. Dll4 furthermore affects tissue perfusion by acting on arterial function and structure. Loss of Dll4 stimulates collateral formation and angiogenesis, but in the context of ischemic diseases such beneficial effects are overruled by adverse functional changes, demonstrating that ischemic recovery is not solely determined by collateral number but rather by vessel functionality. PMID:23533173

  16. Evaluation of noncoronary sources of left ventricular perfusion to intercoronary collateral-dependent myocardium due to chronic major vessel occlusion: absent contribution of luminal and extracardiac channels

    International Nuclear Information System (INIS)

    Crystal, G.J.; Downey, H.F.; Bashour, F.A.

    1981-01-01

    Liminal contribution to perfusion of collateral-dependent left ventricular (LV) myocardium was evaluated in six dogs. A portion of LV free wall was rendered collateral-dependent by gradual occlusion of left circumflex artery with Ameroid constrictor. Eight to 10 weeks after implantation of constrictor, measurements of LV myocardial flow were made by left atrial injections of 9-10 micro radioactive microspheres. To measure total collateral flow, microspheres were injected under control conditions, and to measure luminal contribution to collateral flow, microspheres were injected after ligation of right coronary artery during extracorporeal perfusion of left common coronary artery (LCCA) with microsphere-free arterial blood, and during stoppage of flow through LCCA. Under control conditions, myocardial blood flow in collateral-dependent region, 1.01 +/- 0.31 ml/min/gm, was not significantly different from that in normal region, 1.06 +/- 0.32 ml/min/gm. Flow from luminal collateral vessels was negligible (less than 0.005 ml/min/gm) in both collateral-dependent and normal myocardium, and was not affected by stoppage of flow through LCCA. These results indicate that luminal collateral vessels, as well as collateral vessels originating from other noncoronary sources, do not contribute significantly to perfusion of normal or collateral-dependent LV myocardium

  17. Portal hypertension: a review of portosystemic collateral pathways and endovascular interventions

    International Nuclear Information System (INIS)

    Pillai, A.K.; Andring, B.; Patel, A.; Trimmer, C.; Kalva, S.P.

    2015-01-01

    The portal vein is formed at the confluence of the splenic and superior mesenteric vein behind the head of the pancreas. Normal blood pressure within the portal system varies between 5 and 10 mmHg. Portal hypertension is defined when the gradient between the portal and systemic venous blood pressure exceeds 5 mmHg. The most common cause of portal hypertension is cirrhosis. In cirrhosis, portal hypertension develops due to extensive fibrosis within the liver parenchyma causing increased vascular resistance. In addition, the inability of the liver to metabolise certain vasodilators leads to hyperdynamic splanchnic circulation resulting in increased portal blood flow. Decompression of the portal pressure is achieved by formation of portosystemic collaterals. In this review, we will discuss the pathophysiology, anatomy, and imaging findings of spontaneous portosystemic collaterals and clinical manifestations of portal hypertension with emphasis on the role of interventional radiology in the management of complications related to portal hypertension

  18. Portal hypertension: Imaging of portosystemic collateral pathways and associated image-guided therapy.

    Science.gov (United States)

    Bandali, Murad Feroz; Mirakhur, Anirudh; Lee, Edward Wolfgang; Ferris, Mollie Clarke; Sadler, David James; Gray, Robin Ritchie; Wong, Jason Kam

    2017-03-14

    Portal hypertension is a common clinical syndrome, defined by a pathologic increase in the portal venous pressure. Increased resistance to portal blood flow, the primary factor in the pathophysiology of portal hypertension, is in part due to morphological changes occurring in chronic liver diseases. This results in rerouting of blood flow away from the liver through collateral pathways to low-pressure systemic veins. Through a variety of computed tomographic, sonographic, magnetic resonance imaging and angiographic examples, this article discusses the appearances and prevalence of both common and less common portosystemic collateral channels in the thorax and abdomen. A brief overview of established interventional radiologic techniques for treatment of portal hypertension will also be provided. Awareness of the various imaging manifestations of portal hypertension can be helpful for assessing overall prognosis and planning proper management.

  19. Sphingosine-1-Phosphate Receptor-1 Selective Agonist Enhances Collateral Growth and Protects against Subsequent Stroke.

    Directory of Open Access Journals (Sweden)

    Masahiko Ichijo

    Full Text Available Collateral growth after acute occlusion of an intracranial artery is triggered by increasing shear stress in preexisting collateral pathways. Recently, sphingosine-1-phosphate receptor-1 (S1PR1 on endothelial cells was reported to be essential in sensing fluid shear stress. Here, we evaluated the expression of S1PR1 in the hypoperfused mouse brain and investigated the effect of a selective S1PR1 agonist on leptomeningeal collateral growth and subsequent ischemic damage after focal ischemia.In C57Bl/6 mice (n = 133 subjected to unilateral common carotid occlusion (CCAO and sham surgery. The first series examined the time course of collateral growth, cell proliferation, and S1PR1 expression in the leptomeningeal arteries after CCAO. The second series examined the relationship between pharmacological regulation of S1PR1 and collateral growth of leptomeningeal anastomoses. Animals were randomly assigned to one of the following groups: LtCCAO and daily intraperitoneal (i.p. injection for 7 days of an S1PR1 selective agonist (SEW2871, 5 mg/kg/day; sham surgery and daily i.p. injection for 7 days of SEW2871 after surgery; LtCCAO and daily i.p. injection for 7 days of SEW2871 and an S1PR1 inverse agonist (VPC23019, 0.5 mg/kg; LtCCAO and daily i.p. injection of DMSO for 7 days after surgery; and sham surgery and daily i.p. injection of DMSO for 7 days. Leptomeningeal anastomoses were visualized 14 days after LtCCAO by latex perfusion method, and a set of animals underwent subsequent permanent middle cerebral artery occlusion (pMCAO 7 days after the treatment termination. Neurological functions 1 hour, 1, 4, and 7 days and infarction volume 7 days after pMCAO were evaluated.In parallel with the increase in S1PR1 mRNA levels, S1PR1 expression colocalized with endothelial cell markers in the leptomeningeal arteries, increased markedly on the side of the CCAO, and peaked 7 days after CCAO. Mitotic cell numbers in the leptomeningeal arteries increased after

  20. Spatially Interpolated Disease Prevalence Estimation Using Collateral Indicators of Morbidity and Ecological Risk

    Science.gov (United States)

    Congdon, Peter

    2013-01-01

    This paper considers estimation of disease prevalence for small areas (neighbourhoods) when the available observations on prevalence are for an alternative partition of a region, such as service areas. Interpolation to neighbourhoods uses a kernel method extended to take account of two types of collateral information. The first is morbidity and service use data, such as hospital admissions, observed for neighbourhoods. Variations in morbidity and service use are expected to reflect prevalence. The second type of collateral information is ecological risk factors (e.g., pollution indices) that are expected to explain variability in prevalence in service areas, but are typically observed only for neighbourhoods. An application involves estimating neighbourhood asthma prevalence in a London health region involving 562 neighbourhoods and 189 service (primary care) areas. PMID:24129116