CT perfusion of the liver during selective hepatic arteriography. Pure arterial blood perfusion of liver tumor and parenchyma

International Nuclear Information System (INIS)

Komemushi, Atsushi; Tanigawa, Noboru; Kojima, Hiroyuki; Kariya, Shuji; Sawada, Satoshi

2003-01-01

The purpose of this study was to quantify pure arterial blood perfusion of liver tumor and parenchyma by using CT perfusion during selective hepatic arteriography. A total of 44 patients underwent liver CT perfusion study by injection of contrast medium via the hepatic artery. CT-perfusion parameters including arterial blood flow, arterial blood volume, and arterial mean transit time in the liver parenchyma and liver tumor were calculated using the deconvolution method. The CT-perfusion parameters and vascularity of the tumor were compared. A complete analysis could be performed in 36 of the 44 patients. For liver tumor and liver parenchyma, respectively, arterial blood flow was 184.6±132.7 and 41.0±27.0 ml/min/100 g, arterial blood volume was 19.4±14.6 and 4.8±4.2 ml/100 g, and arterial mean transit time was 8.9±4.2 and 10.2±5.3 sec. Arterial blood flow and arterial blood volume correlated significantly with the vascularity of the tumor; however no correlation was detected between arterial mean transit time and the vascularity of the tumor. This technique could be used to quantify pure hepatic arterial blood perfusion. (author)

Increased sinusoidal volume and solute extraction during retrograde liver perfusion

International Nuclear Information System (INIS)

Bass, N.M.; Manning, J.A.; Weisiger, R.A.

1989-01-01

Retrograde isolated liver perfusion has been used to probe acinar functional heterogeneity, but the hemodynamic effects of backward flow have not been characterized. In this study, extraction of a long-chain fatty acid derivative, 12-N-methyl-7-nitrobenzo-2-oxa-1,3-diazol-amino stearate (12-NBDS), was greater during retrograde than during anterograde perfusion of isolated rat liver. To determine whether hemodynamic differences between anterograde and retrograde perfused livers could account for this finding, the hepatic extracellular space was measured for both directions of flow by means of [ 14 C]sucrose washout during perfusion as well as by direct measurement of [ 14 C]sucrose entrapped during perfusion. A three- to fourfold enlargement of the total hepatic extracellular space was found during retrograde perfusion by both approaches. Examination of perfusion-fixed livers by light microscopy and morphometry revealed that marked distension of the sinusoids occurred during retrograde perfusion and that this accounts for the observed increase in the [ 14 C]sucrose space. These findings support the hypothesis that maximum resistance to perfusate flow in the isolated perfused rat liver is located at the presinusoidal level. In addition, increased transit time of perfusate through the liver and greater sinusoidal surface area resulting from sinusoidal distension may account for the higher extraction of 12-NBDS and possibly other compounds by retrograde perfused liver

CT Perfusion Characteristics Identify Metastatic Sites in Liver

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Yuan Wang

2015-01-01

Full Text Available Tissue perfusion plays a critical role in oncology because growth and migration of cancerous cells require proliferation of new blood vessels through the process of tumor angiogenesis. Computed tomography (CT perfusion is an emerging functional imaging modality that measures tissue perfusion through dynamic CT scanning following intravenous administration of contrast medium. This noninvasive technique provides a quantitative basis for assessing tumor angiogenesis. CT perfusion has been utilized on a variety of organs including lung, prostate, liver, and brain, with promising results in cancer diagnosis, disease prognostication, prediction, and treatment monitoring. In this paper, we focus on assessing the extent to which CT perfusion characteristics can be used to discriminate liver metastases from neuroendocrine tumors from normal liver tissues. The neuroendocrine liver metastases were analyzed by distributed parameter modeling to yield tissue blood flow (BF, blood volume (BV, mean transit time (MTT, permeability (PS, and hepatic arterial fraction (HAF, for tumor and normal liver. The result reveals the potential of CT perfusion as a tool for constructing biomarkers from features of the hepatic vasculature for guiding cancer detection, prognostication, and treatment selection.

THE USE OF NORMOTHERMIC EXTRACORPOREAL PERFUSION IN SITU IN KIDNEY ASYSTOLIC DONORS

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Y.. A. Shcherbuk

2010-01-01

Full Text Available Deficit of donor organs is the limiting factor in organ transplantation. One way of solving this problem is the use of donors with sudden irreversible circulatory arrest. Obtaining organs from this category of donors is pos- sible only through the use of normothermic extracorporal perfusion in situ (NECP with oxygenation and leu- cocyte depletion. The article presents the implementation of NECP in 11 uncontrolled non heart beating donor (uNHBD kidneys (age of 43,1 ± 2,98 years and the results of transplantation in 22 recipients of such transplants in comparison with the results of the 20 recipients of kidney transplants from 20 donors to the death of the brain (age 45,65 ± 1,8 years. Despite the initially high rate of delayed function and more significant number of hemo- dialysis in uNHBD group (group of investigation, serum creatinine at 21st day was the same level as in BDD group (comparison group: 0,198 ± 0,002 mmol/L and 0,151 ± 0,002 mmol/L (p > 0,05. The use of NECP with oxygenation and leucocyte depletion is an effective practice for recovery kidney from donors with a sudden ir- reversible circulatory arrest with warm ischemic time one hour and more before the operation explantation. 

Inducing Hepatitis C Virus Resistance After Pig Liver Transplantation-A Proof of Concept of Liver Graft Modification Using Warm Ex Vivo Perfusion.

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Goldaracena, N; Spetzler, V N; Echeverri, J; Kaths, J M; Cherepanov, V; Persson, R; Hodges, M R; Janssen, H L A; Selzner, N; Grant, D R; Feld, J J; Selzner, M

2017-04-01

Normothermic ex vivo liver perfusion (NEVLP) offers the potential to optimize graft function prior to liver transplantation (LT). Hepatitis C virus (HCV) is dependent on the presence of miRNA(microRNA)-122. Miravirsen, a locked-nucleic acid oligonucleotide, sequesters miR-122 and inhibits HCV replication. The aim of this study was to assess the efficacy of delivering miravirsen during NEVLP to inhibit miR-122 function in a pig LT model. Pig livers were treated with miravirsen during NEVLP or cold storage (CS). Miravirsen absorption, miR-122 sequestration, and miR-122 target gene derepression were determined before and after LT. The effect of miravirsen treatment on HCV infection of hepatoma cells was also assessed. NEVLP improved miravirsen uptake versus CS. Significant miR-122 sequestration and miR-122 target gene derepression were seen with NEVLP but not with CS. In vitro data confirmed miravirsen suppression of HCV replication after established infection and prevented HCV infection with pretreatment of cells, analogous to the pretreatment of grafts in the transplant setting. In conclusion, miravirsen delivery during NEVLP is a potential strategy to prevent HCV reinfection after LT. This is the first large-animal study to provide "proof of concept" for using NEVLP to modify and optimize liver grafts for transplantation. © 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.

A Review of Liver Perfusion Method in Toxicology Studies

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M karami

2014-06-01

Full Text Available Introduction: The isolated perfused rat liver is an accepted method in toxicology studies. The isolated perfused rat liver (IPRL is a useful experimental system for evaluating hepatic function without the influence of other organ systems, undefined plasma constituents, and neural-hormonal effects. Methods: The untreated male rats (180-220gr body weight were anesthetised with ether and then surgery with proper method. The abdomen was opened through a midline and one transversal incision and the bile duct was cannulated. Heparin sodium solution (0.5 ml; 500 U/ml in 0.9% NaCl was injected via the abdominal vena cava to prevent blood clotting. The liver inferior venacava was cannulated with PE-10 tubing and secured. The portal vein was immediately cannulated with an 23gr catheter which was secured and then liver was perfused in situ by Krebs- Henseleit buffer (pH 7.4; saturated with 95% O2 and 5% CO2; 37°C at a flow rate of 20 ml/min for 3hr. Temperature, perfusion pressure, flow rate and perfusion fluid pH were closely monitored during the perfusion. Results: Transferase enzymes (ALT, AST alterations can be widely used as a measure of biochemical alterations in order to assess liver damage due to use of drugs such as isoniazid (INH and animal and plant toxins. Accumulated material in gallbladder are valuable samples to assess the level of Glutathione (GSH. Sections of perfused liver tissue can also be effectively analyzed for pathological aspects such as necrosis, fibrosis, cellularity. Conclusion: The isolated perfused rat liver (IPRL is a useful and Sutible experimental system for evaluating hepatic function. In this system, the effects of adjacent organs, on the liver is minimized

Ex-vivo machine perfusion for kidney preservation.

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Hamar, Matyas; Selzner, Markus

2018-06-01

Machine perfusion is a novel strategy to decrease preservation injury, improve graft assessment, and increase organ acceptance for transplantation. This review summarizes the current advances in ex-vivo machine-based kidney preservation technologies over the last year. Ex-vivo perfusion technologies, such as hypothermic and normothermic machine perfusion and controlled oxygenated rewarming, have gained high interest in the field of organ preservation. Keeping kidney grafts functionally and metabolically active during the preservation period offers a unique chance for viability assessment, reconditioning, and organ repair. Normothermic ex-vivo kidney perfusion has been recently translated into clinical practice. Preclinical results suggest that prolonged warm perfusion appears superior than a brief end-ischemic reconditioning in terms of renal function and injury. An established standardized protocol for continuous warm perfusion is still not available for human grafts. Ex-vivo machine perfusion represents a superior organ preservation method over static cold storage. There is still an urgent need for the optimization of the perfusion fluid and machine technology and to identify the optimal indication in kidney transplantation. Recent research is focusing on graft assessment and therapeutic strategies.

Pulmonary artery perfusion versus no pulmonary perfusion during cardiopulmonary bypass in patients with COPD

DEFF Research Database (Denmark)

Buggeskov, Katrine B; Sundskard, Martin M; Jonassen, Thomas

2016-01-01

INTRODUCTION: Absence of pulmonary perfusion during cardiopulmonary bypass (CPB) may be associated with reduced postoperative oxygenation. Effects of active pulmonary artery perfusion were explored in patients with chronic obstructive pulmonary disease (COPD) undergoing cardiac surgery. METHODS: 90...... perfusion with normothermic oxygenated blood during cardiopulmonary bypass appears to improve postoperative oxygenation in patients with COPD undergoing cardiac surgery. Pulmonary artery perfusion with hypothermic HTK solution does not seem to improve postoperative oxygenation. TRIAL REGISTRATION NUMBER...

Hemodynamic study on liver cirrhosis: clinical application of CT perfusion imaging

International Nuclear Information System (INIS)

Jiang Li; Yang Jianyong; Xie Hongbo; Yang Xufeng; Yan Chaogui; Li Ziping; Zeng Fang

2004-01-01

Objective: To estimate hepatic perfusion parameters with helical CT, and to study the relationship between hepatic perfusion parameters and the severity of liver cirrhosis. Methods: Dynamic single-section computed tomography (CT) of the liver was performed in 40 participants, including 27 patients with liver cirrhosis and 13 patients without liver disease (control subjects). CT scans were obtained at a single level to include the liver, spleen, aorta, and portal vein. On each CT scan, the attenuation of these organs was measured in regions of interest to provide time-density curves. The arterial, portal venous, and total perfusion of the liver and the hepatic perfusion index were assessed. Results: In the control group, hepatic arterial perfusion, portal venous perfusion, and total hepatic perfusion were (0.2823 ± 0.0969) ml·min -1 ·ml -1 , (1.1788 ± 0.4004) ml·min -1 ·ml -1 , and (1.4563 ± 0.4439) ml·min -1 ·ml -1 , respectively. Hepatic perfusion index was (19.73 ±5.81)%. These hepatic perfusion parameters correlated significantly with the severity of liver cirrhosis. Hepatic arterial perfusion decreased in Child A and B cirrhotic patients [ (0.1685 ± 0.1068) ml·min -1 ·ml -1 and (0.1921 ± 0.0986) ml·min -1 ·ml -1 , respectively]. Comparing to Child A and B cirrhotic patients, hepatic arterial perfusion in Child C cirrhotic patients [(0.3072 · 0.1145) ml·min -1 ·ml -1 ] raised significantly. Portal venous perfusion decreased significantly in Child B and C cirrhotic patients [(0.6331±0.2070) ml·min -1 ·ml -1 and (0.5702 ± 0.3562) ml·min -1 ·ml -1 , respectively]. Total hepatic blood flow reduced markedly in Child B and C cirrhotic patients [(0.8252 ± 0.2952) ml·min -1 ·ml -1 and (0.8774 ± 0.4118) ml·min -1 ·ml -1 , respectively]. Hepatic perfusion index increased in Child C cirrhotic patients (37.48 ± 16.65)%. Conclusion: Dynamic single-section CT showed potential in quantifying hepatic perfusion parameters, and hepatic perfusion

Plasma proteomic changes during hypothermic and normothermic cardiopulmonary bypass in aortic surgeries.

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Oda, Teiji; Yamaguchi, Akane; Yokoyama, Masao; Shimizu, Koji; Toyota, Kosaku; Nikai, Tetsuro; Matsumoto, Ken-Ichi

2014-10-01

Deep hypothermic circulatory arrest (DHCA) is a protective method against brain ischemia in aortic surgery. However, the possible effects of DHCA on the plasma proteins remain to be determined. In the present study, we used novel high‑throughput technology to compare the plasma proteomes during DHCA (22˚C) with selective cerebral perfusion (SCP, n=7) to those during normothermic cardiopulmonary bypass (CPB, n=7). Three plasma samples per patient were obtained during CPB: T1, prior to cooling; T2, during hypothermia; T3, after rewarming for the DHCA group and three corresponding points for the normothermic group. A proteomic analysis was performed using isobaric tag for relative and absolute quantification (iTRAQ) labeling tandem mass spectrometry to assess quantitative protein changes. In total, the analysis identified 262 proteins. The bioinformatics analysis revealed a significant upregulation of complement activation at T2 in normothermic CPB, which was suppressed in DHCA. These findings were confirmed by the changes of the terminal complement complex (SC5b‑9) levels. At T3, however, the level of SC5b‑9 showed a greater increase in DHCA compared to normothermic CPB, while 48 proteins were significantly downregulated in DHCA. The results demonstrated that DHCA and rewarming potentially exert a significant effect on the plasma proteome in patients undergoing aortic surgery.

Possibilities of differentiation of solitary focal liver lesions by computed tomography perfusion

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Irmina Sefić Pašić

2015-08-01

Full Text Available Aim To evaluate possibilities of computed tomography (CT perfusion in differentiation of solitary focal liver lesions based on their characteristic vascularization through perfusion parameters analysis. Methods Prospective study was conducted on 50 patients in the period 2009-2012. Patients were divided in two groups: benign and malignant lesions. The following CT perfusion parameters were analyzed: blood flow (BF, blood volume (BV, mean transit time (MTT, capillary permeability surface area product (PS, hepatic arterial fraction (HAF, and impulse residual function (IRF. During the study another perfusion parameter was analyzed: hepatic perfusion index (HPI. All patients were examined on Multidetector 64-slice CT machine (GE with application of perfusion protocol for liver with i.v. administration of contrast agent. Results In both groups an increase of vascularization and arterial blood flow was noticed, but there was no significant statistical difference between any of 6 analyzed parameters. Hepatic perfusion index values were increased in all lesions in comparison with normal liver parenchyma. Conclusion Computed tomography perfusion in our study did not allow differentiation of benign and malignant liver lesions based on analysis of functional perfusion parameters. Hepatic perfusion index should be investigated in further studies as a parameter for detection of possible presence of micro-metastases in visually homogeneous liver in cases with no lesions found during standard CT protocol

Prediction of Liver Function by Using Magnetic Resonance-based Portal Venous Perfusion Imaging

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Cao Yue, E-mail: yuecao@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Wang Hesheng [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Johnson, Timothy D. [Department of Biostatistics, University of Michigan, Ann Arbor, Michigan (United States); Pan, Charlie [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Hussain, Hero [Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Balter, James M.; Normolle, Daniel; Ben-Josef, Edgar; Ten Haken, Randall K.; Lawrence, Theodore S.; Feng, Mary [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)

2013-01-01

Purpose: To evaluate whether liver function can be assessed globally and spatially by using volumetric dynamic contrast-enhanced magnetic resonance imaging MRI (DCE-MRI) to potentially aid in adaptive treatment planning. Methods and Materials: Seventeen patients with intrahepatic cancer undergoing focal radiation therapy (RT) were enrolled in institution review board-approved prospective studies to obtain DCE-MRI (to measure regional perfusion) and indocyanine green (ICG) clearance rates (to measure overall liver function) prior to, during, and at 1 and 2 months after treatment. The volumetric distribution of portal venous perfusion in the whole liver was estimated for each scan. We assessed the correlation between mean portal venous perfusion in the nontumor volume of the liver and overall liver function measured by ICG before, during, and after RT. The dose response for regional portal venous perfusion to RT was determined using a linear mixed effects model. Results: There was a significant correlation between the ICG clearance rate and mean portal venous perfusion in the functioning liver parenchyma, suggesting that portal venous perfusion could be used as a surrogate for function. Reduction in regional venous perfusion 1 month after RT was predicted by the locally accumulated biologically corrected dose at the end of RT (P<.0007). Regional portal venous perfusion measured during RT was a significant predictor for regional venous perfusion assessed 1 month after RT (P<.00001). Global hypovenous perfusion pre-RT was observed in 4 patients (3 patients with hepatocellular carcinoma and cirrhosis), 3 of whom had recovered from hypoperfusion, except in the highest dose regions, post-RT. In addition, 3 patients who had normal perfusion pre-RT had marked hypervenous perfusion or reperfusion in low-dose regions post-RT. Conclusions: This study suggests that MR-based volumetric hepatic perfusion imaging may be a biomarker for spatial distribution of liver function, which

Hypothermic versus normothermic cardiopulmonary bypass in patients with valvular heart disease.

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Lomivorotov, Vladimir V; Shmirev, Vladimir A; Efremov, Sergey M; Ponomarev, Dmitry N; Moroz, Gleb B; Shahin, Denis G; Kornilov, Igor A; Shilova, Anna N; Lomivorotov, Vladimir N; Karaskov, Alexander M

2014-04-01

The aim of this study was to test the hypothesis that normothermic cardiopulmonary bypass (CPB) is as effective as hypothermic CPB in terms of cardiac protection (cTnI level) and outcome in patients with valvular heart disease. Prospective randomized study. A tertiary cardiothoracic referral center. 140 patients who had valvular heart disease, with/without coronary artery disease, surgically treated under CPB. The patients were allocated randomly to undergo either hypothermic (temperature [T], 31 °C-32 °C) or normothermic CPB (T>36 °C). The primary endpoint was the dynamics of troponin I. The secondary endpoints were ventilation time, the need for inotropic support, intensive care unit (ICU) and hospital stay durations, complications, and mortality. There were no significant intergroup differences in dynamics of troponin I. Ventilation time was significantly lower in the hypothermic group (6 (5-9) and 8 (5-12); p = 0.01). Normothermic CPB in patients with valvular heart disease was as effective as hypothermic perfusion in terms of myocardial protection after the surgery assessed by cTnI release. The short ventilation duration in patients who underwent hypothermic CPB needs to be confirmed in a future investigation. Copyright © 2014 Elsevier Inc. All rights reserved.

Metabolism of 1-[14C]nitropyrene in isolated perfused rat livers

International Nuclear Information System (INIS)

Bond, J.A.; Medinsky, M.A.; Dutcher, J.S.

1984-01-01

1-Nitropyrene (1-NP), a constituent of diesel exhaust, is carcinogenic to rats and is a bacterial and mammalian mutagen. Biliary and fecal excretion of 1-NP metabolites are the major routes of excretion in rats, suggesting that hepatic metabolism plays a dominant role in determining the biological fate of 1-NP. The purpose of this investigation was to quantitate 1-[14C]NP metabolites formed in isolated perfused rat livers and excreted in bile from rats. Perfused rat livers displayed a capacity for oxidation, reduction, acetylation, and conjugation of 1-NP (or its metabolites). Reduction of 1-NP followed by N-acetylation was the major metabolic pathway observed in the perfused livers. Acetylaminopyrene (AAP) was the major metabolite detected, with total quantities (150 nmol) accounting for about 60% of the total 1-[14C]NP dose (258 nmol) added to the perfusate. Considerably smaller quantities of aminopyrene and hydroxynitropyrenes were also detected. Livers perfused with 1-[14C]NP excreted about 36 nmol equivalents of 1-[14C]NP (12% of the total 1-NP dose) in bile after 60 min. Some of the biliary metabolites were tentatively identified as metabolites of the mercapturic acid pathway. The spectrum of biliary metabolites was qualitatively identical to that seen in bile from intact rats. Quantities of 14C covalently bound to hepatic macromolecules from perfused livers were 0.4 nmol 1-NP eq/g liver. The data from this study indicate that the liver may be an important site for metabolism of 1-NP

Management of Liver Cancer Argon-helium Knife Therapy with Functional Computer Tomography Perfusion Imaging.

Science.gov (United States)

Wang, Hongbo; Shu, Shengjie; Li, Jinping; Jiang, Huijie

2016-02-01

The objective of this study was to observe the change in blood perfusion of liver cancer following argon-helium knife treatment with functional computer tomography perfusion imaging. Twenty-seven patients with primary liver cancer treated with argon-helium knife and were included in this study. Plain computer tomography (CT) and computer tomography perfusion (CTP) imaging were conducted in all patients before and after treatment. Perfusion parameters including blood flows, blood volume, hepatic artery perfusion fraction, hepatic artery perfusion, and hepatic portal venous perfusion were used for evaluating therapeutic effect. All parameters in liver cancer were significantly decreased after argon-helium knife treatment (p knife therapy. Therefore, CTP imaging would play an important role for liver cancer management followed argon-helium knife therapy. © The Author(s) 2014.

[Portal perfusion with right gastroepiploic vein flow in liver transplant].

Science.gov (United States)

Mendoza-Sánchez, Federico; Javier-Haro, Francisco; Mendoza-Medina, Diego Federico; González-Ojeda, Alejandro; Cortés-Lares, José Antonio; Fuentes-Orozco, Clotilde

Liver transplantation in patients with liver cirrhosis, portal vein thrombosis, and cavernous transformation of the portal vein, is a complex procedure with high possibility of liver graft dysfunction. It is performed in 2-19% of all liver transplants, and has a significantly high mortality rate in the post-operative period. Other procedures to maintain portal perfusion have been described, however there are no reports of liver graft perfusion using right gastroepiploic vein. A 20 year-old female diagnosed with cryptogenic cirrhosis, with a Child-Pugh score of 7 points (class "B"), and MELD score of 14 points, with thrombosis and cavernous transformation of the portal vein, severe portal hypertension, splenomegaly, a history of upper gastrointestinal bleeding due to oesophageal varices, and left renal agenesis. The preoperative evaluation for liver transplantation was completed, and the right gastroepiploic vein of 1-cm diameter was observed draining to the infrahepatic inferior vena cava and right suprarenal vein. An orthotopic liver transplantation was performed from a non-living donor (deceased on January 30, 2005) using the Piggy-Back technique. Portal vein perfusion was maintained using the right gastroepiploic vein, and the outcome was satisfactory. The patient was discharged 13 days after surgery. Liver transplantation was performed satisfactorily, obtaining an acceptable outcome. In this case, the portal perfusion had adequate blood flow through the right gastroepiploic vein. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

The Groningen hypothermic liver perfusion pump : Functional evaluation of a new machine perfusion system

NARCIS (Netherlands)

van der Plaats, A.; Maathuis, M. H. J.; Hart, N. A. 't; Bellekom, A. A.; Hofker, H. S.; van der Houwen, E. B.; Verkerke, G. J.; Leuvenink, H. G. D.; Verdonck, P.; Ploeg, R. J.; Rakhorst, G.

2006-01-01

To improve preservation of donor livers, we have developed a portable hypothermic machine perfusion (HMP) system as an alternative for static cold storage. A prototype of the system was built and evaluated on functionality. Evaluation criteria included 24 h of adequate pressure controlled perfusion,

Optical fluorescence spectroscopy to detect hepatic necrosis after normothermic ischemia: animal model

Science.gov (United States)

Romano, Renan A.; Vollet-Filho, Jose D.; Pratavieira, Sebastião.; Fernandez, Jorge L.; Kurachi, Cristina; Bagnato, Vanderlei S.; Castro-e-Silva, Orlando; Sankarankutty, Ajith K.

2015-06-01

Liver transplantation is a well-established treatment for liver failure. However, the success of the transplantation procedure depends on liver graft conditions. The tissue function evaluation during the several transplantation stages is relevant, in particular during the organ harvesting, when a decision is made concerning the viability of the graft. Optical fluorescence spectroscopy is a good option because it is a noninvasive and fast technique. A partial normothermic hepatic ischemia was performed in rat livers, with a vascular occlusion of both median and left lateral lobes, allowing circulation only for the right lateral lobe and the caudate lobe. Fluorescence spectra under excitation at 532 nm (doubled frequency Nd:YAG laser) were collected using a portable spectrometer (USB2000, Ocean Optics, USA). The fluorescence emission was collected before vascular occlusion, after ischemia, and 24 hours after reperfusion. A morphometric histology analysis was performed as the gold standard evaluation - liver samples were analyzed, and the percentage of necrotic tissue was obtained. The results showed that changes in the fluorescence emission after ischemia can be correlated with the amount of necrosis evaluated by a morphometric analysis, the Pearson correlation coefficient of the generated model was 0.90 and the root mean square error was around 20%. In this context, the laser-induced fluorescence spectroscopy technique after normothermic ischemia showed to be a fast and efficient method to differentiate ischemic injury from viable tissues.

Production of acetone and conversion of acetone to acetate in the perfused rat liver

International Nuclear Information System (INIS)

Gavino, V.C.; Somma, J.; Philbert, L.; David, F.; Garneau, M.; Belair, J.; Brunengraber, H.

1987-01-01

The utilization of millimolar concentrations of [2- 14 C]acetone and the production of acetone from acetoacetate were studied in perfused livers from 48-h starved rats. We devised a procedure for determining, in a perfused liver system, the first-order rate constant for the decarboxylation of acetoacetate (0.29 +/- 0.09 h-1, S.E., n = 8). After perfusion of livers with [2- 14 C]acetone, labeled acetate was isolated from the perfusion medium and characterized as [1- 14 C]acetate. No radioactivity was found in lactate or 3-hydroxybutyrate. After 90 min of perfusion with [2- 14 C]acetone, the specific activity of acetate was 30 +/- 4% (n = 13) of the initial specific activity of acetone. We conclude that, in perfused livers from 2-day starved rats, acetone metabolism occurs for the most part via free acetate

31P-NMR studies on perfused mouse liver

International Nuclear Information System (INIS)

McLaughlin, A.C.; Takeda, H.; Chance, B.

1978-01-01

From a metabolic viewpoint, the most important organ in the body is the liver. In contrast to more specialized organs such as heart and kidney which perform only one major function, the liver performs a number of major metabolic functions. Two of the most important functions are the catabolism and storage of foodstuffs (in the form of glycogen) and the control of most of the constituents of the blood (in particular, the blood glucose level). Most of these functions are localized within a single type of cell. One way that the liver is able to regulate these diverse reactions is by the control of the ATP level in the cell. Encouraged by the recent success of many groups in using 31 P-NMR to provide a continuous and non-destructive monitor of ATP levels in isolated cells, skeletal muscle, and perfused organs such as heart and kidney, 31 P-NMR was used to investigate ATP levels in perfused liver of mice

An Innovative Hyperbaric Hypothermic Machine Perfusion Protects the Liver from Experimental Preservation Injury

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Ferdinando A. Giannone

2012-01-01

Full Text Available Purpose. Hypothermic machine perfusion systems seem more effective than the current static storage to prevent cold ischemic liver injury. Thus, we test an innovative hyperbaric hypothermic machine perfusion (HHMP, which combines hyperbaric oxygenation of the preservation solution and continuous perfusion of the graft. Methods. Rat livers were preserved with Celsior solution according to 4 different modalities: normobaric static preservation; hyperbaric static preservation at 2 atmosphere absolute (ATA; normobaric dynamic preservation, with continuous perfusion; hyperbaric dynamic preservation, with continuous perfusion at 2 ATA. After 24 h cold preservation, we assessed different parameters. Results. Compared to baseline, livers preserved with the current static storage showed severe ultrastructural damage, glycogen depletion and an increased oxidative stress. Normobaric perfused livers showed improved hepatocyte ultrastructure and ameliorated glycogen stores, but they still suffered a significant oxidative damage. The addition of hyperbaric oxygen produces an extra benefit by improving oxidative injury and by inducing endothelial NO synthase (eNOS gene expression. Conclusions. Preservation by means of the present innovative HHMP reduced the liver injury occurring after the current static cold storage by lowering glycogen depletion and oxidative damage. Interestingly, only the use of hyperbaric oxygen was associated to a blunted oxidative stress and an increased eNOS gene expression.

Assessment of right liver graft perfusion effectiveness between one and two-catheter infusion methods.

Science.gov (United States)

Jung, Bo-Hyun; Hwang, Shin; Ha, Tae-Yong; Song, Gi-Won; Jung, Dong-Hwan; Kim, Ki-Hun; Ahn, Chul-Soo; Moon, Deok-Bog; Park, Gil-Chun; Kang, Sung-Hwa; Yoon, Young-In; Lee, Sung-Gyu

2014-05-01

Conventional graft perfusion method using one small-caliber catheter takes a relatively long time for right liver graft perfusion, thus some modification is needed. In this study, we intended to assess the effectiveness of right liver graft perfusion methods through comparison of different infusion catheters. The study consisted of two parts including one bench experiment to obtain data of hydraulic infusion and one clinical trial of 40 cases on graft perfusion with one- versus two-catheter infusion methods. These two graft infusion methods were compared in terms of the perfusion time and washing-out efficiency. At bench experiment, the infusion flow rate and infusion pressure were 3.3 ml/sec and 1.9 cmH20 in one blood transfusion catheter group, and 11.7 ml/sec and 3.1 cmH20 in single transurethral resection of prostate irrigation catheter group, and 6.6 ml/sec and 2.0 cmH20 in two blood transfusion catheters group, respectively. In clinical trial with 40 right liver grafts, two-catheter group had a shorter graft portal perfusion time for the first 2 L of histidine-tryptophan-ketoglutarate (HTK) solution than the conventional one-catheter group (375±25 seconds vs. 662±34 seconds; p=0.001) and a lower rate of incomplete blood washing-out after the initial 2 L portal perfusion (40% vs. 85%; p=0.03). The two-catheter infusion method appears to be more effective than the conventional one-catheter infusion method for right liver graft perfusion at the back table. Large size of right liver grafts seems to be its good indication.

Cell-swelling-induced taurine release from isolated perfused rat liver

NARCIS (Netherlands)

Brand, H. S.; Meijer, A. J.; Gustafson, L. A.; Jörning, G. G.; Leegwater, A. C.; Maas, M. A.; Chamuleau, R. A.

1994-01-01

Astrocytes and lymphocytes are able to release significant amounts of taurine during periods of hypotonicity to reduce the increase in cell volume. To investigate this mechanism in the liver, we studied the release of free amino acids from isolated perfused rat liver during hypotonicity. The

Perfusion computed tomography for detection of hepatocellular carcinoma in patients with liver cirrhosis

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Fischer, Michael A.; Kartalis, Nikolaos; Grigoriadis, Aristeidis; Loizou, Louiza; Leidner, Bertil; Aspelin, Peter; Brismar, Torkel B. [Karolinska Institute, Department of Clinical Science, Intervention and Technology, Division of Medical Imaging and Technology, Stockholm (Sweden); Karolinska University Hospital, Department of Radiology, Stockholm (Sweden); Staal, Per [Karolinska University Hospital, Department of Hepatology, Stockholm (Sweden)

2015-11-15

To evaluate the diagnostic performance of dynamic perfusion CT (P-CT) for detection of hepatocellular carcinoma (HCC) in the cirrhotic liver. Twenty-six cirrhotic patients (19 men, aged 69 ± 10 years) with suspicion of HCC prospectively underwent P-CT of the liver using the 4D spiral-mode (100/80 kV; 150/175mAs/rot) of a dual-source system. Two readers assessed: (1) arterial liver-perfusion (ALP), portal-venous liver-perfusion (PLP) and hepatic perfusion-index (HPI) maps alone; and (2) side-by-side with maximum-intensity-projections of arterial time-points (art-MIP) for detection of HCC using histopathology and imaging follow-up as standard of reference. Another reader quantitatively assessed perfusion maps of detected lesions. A total of 48 HCCs in 21/26 (81 %) patients with a mean size of 20 ± 10 mm were detected by histopathology (9/48, 19 %) or imaging follow-up (39/48, 81 %). Detection rates (Reader1/Reader2) of HPI maps and side-by-side analysis of HPI combined with arterial MIP were 92/88 % and 98/96 %, respectively. Positive-predictive values were 63/63 % and 68/71 %, respectively. A cut-off value of ≥85 % HPI and ≥99 % HPI yielded a sensitivity and specificity of 100 %, respectively, for detection of HCC. P-CT shows a high sensitivity for detection of HCC in the cirrhotic liver. Quantitative assessment has the potential to reduce false-positive findings improving the specificity of HCC diagnosis. (orig.)

Functional state of perfused liver tissue in X-ray irradiated rats

Energy Technology Data Exchange (ETDEWEB)

Borovikova, G.V.; Dokshina, G.A.; Lapteva, T.A. (Tomskij Gosudarstvennyj Univ. (USSR). Nauchno-Issledovatel' skij Inst. Biologii i Biofiziki)

1981-01-01

The results of studying the functional state of perfused liver tissue isolated from rats after irradiation in the 18.06x10/sup -2/ Kl/kg dose, which has been estimated by transamination process rate catalized alanine-(KF 2.6x1.2, ALT and aspartate by aminotransferases (KF 2.6x1.1, ACT), gluconeogenesis and urea production intensity presented. When comparing the results obtained on the perfused liver deprived of homeostatic body effects it has been found that the liver isolated from the body for the first 24 hours of the radiation sickness development possesses a higher radiation activity which manifests itself in intensification of the processes of gluconeogenesis and transamination with substrate addition. The third 24 hours upon irradiation in the isolated liver the intensity of the gluconeogenesis and transamination processes is attenuated.

Cerebral blood flow measured by positron emission tomography during normothermic cardiopulmonary bypass: An experimental porcine study

DEFF Research Database (Denmark)

Thomassen, Sisse Anette; Kjaergaard, Benedict; Alstrup, Aage Kristian Olsen

2018-01-01

emission tomography (PET) using 15O-labelled water with no pharmacological interventions to maintain the MAP. Methods: Eight pigs (69-71 kg) were connected to normothermic CPB. After 60 minutes (min) with a CPB pump flow of 60 mL/kg/min, the pigs were changed to either 35 mL/kg/min or 47.5 mL/kg/min for 60......Background: Mean arterial blood pressure (MAP) and/or pump flow during normothermic cardiopulmonary bypass (CPB) are the most important factors of cerebral perfusion. The aim of this study was to explore the influence of CPB blood flow on cerebral blood flow (CBF) measured by dynamic positron...... min and, thereafter, all the pigs returned to 60 mL/kg/min for another 60 min. The MAP was measured continuously and the CBF was measured by positron emission tomography (PET) during spontaneous circulation and at each CPB pump flow after 30 min of steady state. Results: Two pigs were excluded due...

The functional state of perfused liver tissue in X-ray irradiated rats

International Nuclear Information System (INIS)

Borovikova, G.V.; Dokshina, G.A.; Lapteva, T.A.

1981-01-01

The results of studying the functional state of perfused liver tissue isolated from rates after irradiation in the 18.06x10 - 2 Kl/kg dose, which has been estimated by transamination process rate catalized alanine-(KF 2.6x1.2, ALT and aspartate by aminotransferases (KF 2.6x1.1, ACT), gluconeogenesis and urea production intensity presented. When comparing the results obtained on the perfused liver deprived of homeostatic body effects it has been found that the liver isolated from the body for the first 24 hours of the radiation sickness development possesses a higher radiation activity which manifests itself in intensification of the processes of gluconeogenesis and transamination with substrate addition. The third 24 hours upon irradiation in the isolated liver the intensity of the gluconeogenesis and transamination processes is attenuated

Percutaneous Isolated Hepatic Perfusion for the Treatment of Unresectable Liver Malignancies

Energy Technology Data Exchange (ETDEWEB)

Burgmans, Mark C., E-mail: m.c.burgmans@lumc.nl [Leiden University Medical Centre, Department of Radiology (Netherlands); Leede, Eleonora M. de, E-mail: e.m.de-leede@lumc.nl [Leiden University Medical Centre, Department of Surgery (Netherlands); Martini, Christian H., E-mail: c.h.martini@lumc.nl [Leiden University Medical Centre, Department of Anesthesiology (Netherlands); Kapiteijn, Ellen, E-mail: h.w.kapiteijn@lumc.nl [Leiden University Medical Centre, Department of Medical Oncology (Netherlands); Vahrmeijer, Alexander L., E-mail: a.l.vahrmeijer@lumc.nl [Leiden University Medical Centre, Department of Surgery (Netherlands); Erkel, Arian R. van, E-mail: a.r.van-erkel@lumc.nl [Leiden University Medical Centre, Department of Radiology (Netherlands)

2016-06-15

Liver malignancies are a major burden of disease worldwide. The long-term prognosis for patients with unresectable tumors remains poor, despite advances in systemic chemotherapy, targeted agents, and minimally invasive therapies such as ablation, chemoembolization, and radioembolization. Thus, the demand for new and better treatments for malignant liver tumors remains high. Surgical isolated hepatic perfusion (IHP) has been shown to be effective in patients with various hepatic malignancies, but is complex, associated with high complication rates and not repeatable. Percutaneous isolated liver perfusion (PHP) is a novel minimally invasive, repeatable, and safer alternative to IHP. PHP is rapidly gaining interest and the number of procedures performed in Europe now exceeds 200. This review discusses the indications, technique and patient management of PHP and provides an overview of the available data.

Percutaneous Isolated Hepatic Perfusion for the Treatment of Unresectable Liver Malignancies

International Nuclear Information System (INIS)

Burgmans, Mark C.; Leede, Eleonora M. de; Martini, Christian H.; Kapiteijn, Ellen; Vahrmeijer, Alexander L.; Erkel, Arian R. van

2016-01-01

Liver malignancies are a major burden of disease worldwide. The long-term prognosis for patients with unresectable tumors remains poor, despite advances in systemic chemotherapy, targeted agents, and minimally invasive therapies such as ablation, chemoembolization, and radioembolization. Thus, the demand for new and better treatments for malignant liver tumors remains high. Surgical isolated hepatic perfusion (IHP) has been shown to be effective in patients with various hepatic malignancies, but is complex, associated with high complication rates and not repeatable. Percutaneous isolated liver perfusion (PHP) is a novel minimally invasive, repeatable, and safer alternative to IHP. PHP is rapidly gaining interest and the number of procedures performed in Europe now exceeds 200. This review discusses the indications, technique and patient management of PHP and provides an overview of the available data.

Quantitative dual energy CT measurements in rabbit VX2 liver tumors: Comparison to perfusion CT measurements and histopathological findings

International Nuclear Information System (INIS)

Zhang, Long Jiang; Wu, Shengyong; Wang, Mei; Lu, Li; Chen, Bo; Jin, Lixin; Wang, Jiandong; Larson, Andrew C.; Lu, Guang Ming

2012-01-01

Purpose: To evaluate the correlation between quantitative dual energy CT and perfusion CT measurements in rabbit VX2 liver tumors. Materials and methods: This study was approved by the institutional animal care and use committee at our institution. Nine rabbits with VX2 liver tumors underwent contrast-enhanced dual energy CT and perfusion CT. CT attenuation for the tumors and normal liver parenchyma and tumor-to-liver ratio were obtained at the 140 kVp, 80 kVp, average weighted images and dual energy CT iodine maps. Quantitative parameters for the viable tumor and adjacent liver were measured with perfusion CT. The correlation between the enhancement values of the tumor in iodine maps and perfusion CT parameters of each tumor was analyzed. Radiation dose from dual energy CT and perfusion CT was measured. Results: Enhancement values for the tumor were higher than that for normal liver parenchyma at the hepatic arterial phase (P < 0.05). The highest tumor-to-liver ratio was obtained in hepatic arterial phase iodine map. Hepatic blood flow of the tumor was higher than that for adjacent liver (P < 0.05). Enhancement values of hepatic tumors in the iodine maps positively correlated with permeability of capillary vessel surface (r = 0.913, P < 0.001), hepatic blood flow (r = 0.512, P = 0.010), and hepatic blood volume (r = 0.464, P = 0.022) at the hepatic arterial phases. The effective radiation dose from perfusion CT was higher than that from DECT (P < 0.001). Conclusions: The enhancement values for viable tumor tissues measured in iodine maps were well correlated to perfusion CT measurements in rabbit VX2 liver tumors. Compared with perfusion CT, dual energy CT of the liver required a lower radiation dose.

A relative study of hepatic perfusion and portal vein pressure in rats with liver cirrhosis

International Nuclear Information System (INIS)

Li Jiaping; Yang Jianyong; Chen Wei; Huang Yonghui

2006-01-01

Objective: To evaluate spiral CT perfusion in assessing portal vein pressure in rats with different stages of liver cirrhosis. Methods Seventeen rats with early stage of liver cirrhosis, 18 with intermediate stage, 12 with advanced stage, and 13 healthy rats as a control group were selected and recieved hepatic perfusion on a single-row spiral CT scanner. The parameters of hepatic perfusion were calculated using the deconvolution method. The portal vein pressure was measured by multi-physiographer. Results: (1) In study group, the PVP (portal venous perfusion) and THBP (total hepatic blood perfusion) were negatively correlated with FPP, while positively correlated with the HPI (hepatic perfusion index) and MTT (mean transit time). The FPP had a close relation with PVP. The equation, Y 20.671-3.195X, could be conducted with linear regression analysis. (2) According to the linear regression equation mentioned above, the FPP in 47 rats were 16.090±2.150 cmH 2 0, which was highly correlated with the observed valuel6.108±3.662 cmH 2 O (r=0.823 P<0.01). Conclusion: CT perfusion is a new non-invasive and efficient modality for assessment of the portal pressure in liver cirrhosis in various stages. (authors)

Evaluation of portal hypertension: a comparison of the use of liver perfusion CT with wedge hepatic venous pressure and hepatic

International Nuclear Information System (INIS)

Chung, Dong Jin; Kim, Young Joong; Park, Yong Sung; Lee, Tae Hee; Kim, Chong Soo; Kang, Heung Keun

2008-01-01

We compared the hepatic perfusion indices obtained using hepatic perfusion CT with the wedge hepatic venous pressure (WHVP) and hepatic venous pressure gradient (HVPG) to determine the efficacy of the use of liver perfusion CT for the evaluation of portal hypertension. Thirty-five patients with liver cirrhosis underwent hepatic vein catheterization to measure WHVP and HVPG and underwent a liver perfusion CT examination. Arterial perfusion, portal perfusion, total perfusion and the hepatic perfusion index (HPI) were calculated by the methods described by Miles and Blomlely. The overall correlation coefficients (r) between the perfusion indices and WHVP and HVPG were calculated. An additional correlation coefficient of 23 alcoholic cirrhosis patients was calculated. Using Blomley's equation, HPI had a positive correlation with WHVP (r = .471; ρ < .05) and HVPG (r = .482; ρ < .05). For the alcoholic liver cirrhosis patients, HPI had a higher positive correlation with WHVP (r = .500; ρ < .05) and HVPG (r = .539; ρ < .05) than for the non-alcoholic cirrhosis patients. There was no statistical difference between the use of Miles' equation and Blomley's equation for the evaluation of portal hypertension. This preliminary study showed that HPI positively correlated with WHVP and HVPG, especially in alcoholic cirrhosis patients. Liver perfusion CT may be useful in the evaluation of portal hypertension

CT arteriography via the right inferior phrenic artery developed parasitic perfusion into the liver

International Nuclear Information System (INIS)

Inaba, Yoshitaka; Arai, Yasuaki; Sueyoshi, Satoshi; Yamagami, Takuji; Aramaki, Takeshi; Yamaura, Hidekazu; Matsueda, Kiyoshi; Sasaki, Fumio; Takeuchi, Yoshihito.

1998-01-01

The distribution of arterial blood flow via the right inferior phrenic artery (rt-IPA) developing parasitic perfusion into the liver was evaluated by CT arteriography (CTA) in 50 cases with hepatic tumors. In all cases, CTA via rt-IPA showed hyperperfusion area including hepatic tumors in the posterior segment and the caudate lobe of the liver, and adding the left hepatic lobe in cases with hepatic arterial occlusion. In 82% of 33 cases obtained both CTA via rt-IPA and CTA via hepatic artery, the hyperperfusion area on CTA via rt-IPA exactly corresponded to perfusion defect area on CTA via hepatic artery. CTA was much useful for understanding hemodynamics in cases with parasitic perfusion into the liver and it could make transcatheter arterial therapy more effective. (author)

CT arteriography via the right inferior phrenic artery developed parasitic perfusion into the liver

Energy Technology Data Exchange (ETDEWEB)

Inaba, Yoshitaka; Arai, Yasuaki; Sueyoshi, Satoshi; Yamagami, Takuji; Aramaki, Takeshi; Yamaura, Hidekazu; Matsueda, Kiyoshi; Sasaki, Fumio [Aichi Cancer Center, Nagoya (Japan); Takeuchi, Yoshihito

1998-02-01

The distribution of arterial blood flow via the right inferior phrenic artery (rt-IPA) developing parasitic perfusion into the liver was evaluated by CT arteriography (CTA) in 50 cases with hepatic tumors. In all cases, CTA via rt-IPA showed hyperperfusion area including hepatic tumors in the posterior segment and the caudate lobe of the liver, and adding the left hepatic lobe in cases with hepatic arterial occlusion. In 82% of 33 cases obtained both CTA via rt-IPA and CTA via hepatic artery, the hyperperfusion area on CTA via rt-IPA exactly corresponded to perfusion defect area on CTA via hepatic artery. CTA was much useful for understanding hemodynamics in cases with parasitic perfusion into the liver and it could make transcatheter arterial therapy more effective. (author)

Differential and directional effects of perfusion on electrical and thermal conductivities in liver.

Science.gov (United States)

Podhajsky, Ronald J; Yi, Ming; Mahajan, Roop L

2009-01-01

Two different measurement probes--an electrical probe and a thermal conductivity probe--were designed, fabricated, calibrated, and used in experimental studies on a pig liver model that was designed to control perfusion rates. These probes were fabricated by photolithography and mounted in 1.5-mm diameter catheters. We measured the local impedance and thermal conductivity, respectively, of the artificially perfused liver at different flow rates and, by rotating the probes, in different directions. The results show that both the local electrical conductivity and the thermal conductivity varied location to location, that thermal conductivity increased with decreased distance to large blood vessels, and that significant directional differences exist in both electrical and thermal conductivities. Measurements at different perfusion rates demonstrated that both the local electrical and local thermal conductivities increased linearly with the square root of perfusion rate. These correlations may be of great value to many energy-based biomedical applications.

Assessment of tumor vascularization with functional computed tomography perfusion imaging in patients with cirrhotic liver disease.

Science.gov (United States)

Li, Jin-Ping; Zhao, De-Li; Jiang, Hui-Jie; Huang, Ya-Hua; Li, Da-Qing; Wan, Yong; Liu, Xin-Ding; Wang, Jin-E

2011-02-01

Hepatocellular carcinoma (HCC) is a common malignant tumor in China, and early diagnosis is critical for patient outcome. In patients with HCC, it is mostly based on liver cirrhosis, developing from benign regenerative nodules and dysplastic nodules to HCC lesions, and a better understanding of its vascular supply and the hemodynamic changes may lead to early tumor detection. Angiogenesis is essential for the growth of primary and metastatic tumors due to changes in vascular perfusion, blood volume and permeability. These hemodynamic and physiological properties can be measured serially using functional computed tomography perfusion (CTP) imaging and can be used to assess the growth of HCC. This study aimed to clarify the physiological characteristics of tumor angiogenesis in cirrhotic liver disease by this fast imaging method. CTP was performed in 30 volunteers without liver disease (control subjects) and 49 patients with liver disease (experimental subjects: 27 with HCC and 22 with cirrhosis). All subjects were also evaluated by physical examination, laboratory screening and Doppler ultrasonography of the liver. The diagnosis of HCC was made according to the EASL criteria. All patients underwent contrast-enhanced ultrasonography, pre- and post-contrast triple-phase CT and CTP study. A mathematical deconvolution model was applied to provide hepatic blood flow (HBF), hepatic blood volume (HBV), mean transit time (MTT), permeability of capillary vessel surface (PS), hepatic arterial index (HAI), hepatic arterial perfusion (HAP) and hepatic portal perfusion (HPP) data. The Mann-Whitney U test was used to determine differences in perfusion parameters between the background cirrhotic liver parenchyma and HCC and between the cirrhotic liver parenchyma with HCC and that without HCC. In normal liver, the HAP/HVP ratio was about 1/4. HCC had significantly higher HAP and HAI and lower HPP than background liver parenchyma adjacent to the HCC. The value of HBF at the tumor

Evaluation of portal hypertension: a comparison of the use of liver perfusion CT with wedge hepatic venous pressure and hepatic

Energy Technology Data Exchange (ETDEWEB)

Chung, Dong Jin; Kim, Young Joong; Park, Yong Sung; Lee, Tae Hee [University of Konyang College of Medicine, Daejeon (Korea, Republic of); Kim, Chong Soo; Kang, Heung Keun [Chonbuk National University Medical School, Jeonju (Korea, Republic of)

2008-09-15

We compared the hepatic perfusion indices obtained using hepatic perfusion CT with the wedge hepatic venous pressure (WHVP) and hepatic venous pressure gradient (HVPG) to determine the efficacy of the use of liver perfusion CT for the evaluation of portal hypertension. Thirty-five patients with liver cirrhosis underwent hepatic vein catheterization to measure WHVP and HVPG and underwent a liver perfusion CT examination. Arterial perfusion, portal perfusion, total perfusion and the hepatic perfusion index (HPI) were calculated by the methods described by Miles and Blomlely. The overall correlation coefficients (r) between the perfusion indices and WHVP and HVPG were calculated. An additional correlation coefficient of 23 alcoholic cirrhosis patients was calculated. Using Blomley's equation, HPI had a positive correlation with WHVP (r = .471; {rho} < .05) and HVPG (r = .482; {rho} < .05). For the alcoholic liver cirrhosis patients, HPI had a higher positive correlation with WHVP (r = .500; {rho} < .05) and HVPG (r = .539; {rho} < .05) than for the non-alcoholic cirrhosis patients. There was no statistical difference between the use of Miles' equation and Blomley's equation for the evaluation of portal hypertension. This preliminary study showed that HPI positively correlated with WHVP and HVPG, especially in alcoholic cirrhosis patients. Liver perfusion CT may be useful in the evaluation of portal hypertension.

Normothermic versus hypothermic cardiopulmonary bypass in children undergoing open heart surgery (thermic-2): study protocol for a randomized controlled trial.

Science.gov (United States)

Baos, Sarah; Sheehan, Karen; Culliford, Lucy; Pike, Katie; Ellis, Lucy; Parry, Andrew J; Stoica, Serban; Ghorbel, Mohamed T; Caputo, Massimo; Rogers, Chris A

2015-05-25

During open heart surgery, patients are connected to a heart-lung bypass machine that pumps blood around the body ("perfusion") while the heart is stopped. Typically the blood is cooled during this procedure ("hypothermia") and warmed to normal body temperature once the operation has been completed. The main rationale for "whole body cooling" is to protect organs such as the brain, kidneys, lungs, and heart from injury during bypass by reducing the body's metabolic rate and decreasing oxygen consumption. However, hypothermic perfusion also has disadvantages that can contribute toward an extended postoperative hospital stay. Research in adults and small randomized controlled trials in children suggest some benefits to keeping the blood at normal body temperature throughout surgery ("normothermia"). However, the two techniques have not been extensively compared in children. The Thermic-2 study will test the hypothesis that the whole body inflammatory response to the nonphysiological bypass and its detrimental effects on different organ functions may be attenuated by maintaining the body at 35°C-37°C (normothermic) rather than 28°C (hypothermic) during pediatric complex open heart surgery. This is a single-center, randomized controlled trial comparing the effectiveness and acceptability of normothermic versus hypothermic bypass in 141 children with congenital heart disease undergoing open heart surgery. Children having scheduled surgery to repair a heart defect not requiring deep hypothermic circulatory arrest represent the target study population. The co-primary clinical outcomes are duration of inotropic support, intubation time, and postoperative hospital stay. Secondary outcomes are in-hospital mortality and morbidity, blood loss and transfusion requirements, pre- and post-operative echocardiographic findings, routine blood gas and blood test results, renal function, cerebral function, regional oxygen saturation of blood in the cerebral cortex, assessment of

A disposition kinetic study of Tramadol in bile duct ligated rats in perfused rat liver model.

Science.gov (United States)

Esmaeili, Zohre; Mohammadi, Saeid; Nezami, Alireza; Rouini, Mohammad Reza; Ardakani, Yalda Hosseinzadeh; Lavasani, Hoda; Ghazi-Khansari, Mahmoud

2017-07-01

Tramadol hydrochloride is a centrally acting synthetic opioid analgesic drug and is used to treat chronic pain. In this study, the effects of Bile Duct Ligation (BDL) on the pharmacokinetics of tramadol in a liver recirculating perfusion system of male rats were used. Twenty-four Wistar male rats were randomly divided into four groups: control, sham and two weeks BDL and four weeks BDL. Serum levels of liver enzymes were measured before perfusion and the pharmacokinetics of tramadol was evaluated by using liver recirculating perfusion system. Tramadol and metabolites concentrations were determined by HPLC-FL. The sharp increase in liver enzymes level in both BDL groups was observed and significant changes were also observed in liver weight and volume. Tramadol metabolites concentration significantly decreased compared with the control and sham group (Pbile duct diseases and the dose of tramadol should be accordingly adjusted. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Renal perfusion in chronic liver diseases: Evaluation by radiotechnetium renography

International Nuclear Information System (INIS)

Fanfani, G.; Fratello, A.; Mele, M.; Conte, E.; D'Addabbo, A.; Greco, L.

1985-01-01

Twenty-four patients with chronic liver diseases and seven normal controls were studied using renal and hepatic radiotechnetium angiography. The time-activity histograms generated were employed to calculate both the renal perfusion index (RPI) and the hepatic perfusion index (HPI). Renal perfusion proved to be reduced not only in cirrhotic patients but also in patients with aggressive chronic hepatitis, as well as in those with persistent chronic hepatitis. The HPI, which is to be considered as being strictly dependent on portal flow, only fell significantly in the group of cirrhotic patients. In all patient groups, the correlation coefficient between the HPI and RPI (mean of the two kidneys) was low (r=0.275) and not significant (P>0.05). After Warren's splenorenal derivation, renal perfusion did not improve but worsened, particularly in the left kidney where derivation anastomosis probably caused a venous overload. (orig.)

Correlation between melphalan pharmacokinetics and hepatic toxicity following hyperthermic isolated liver perfusion for unresectable metastatic disease.

Science.gov (United States)

Mocellin, Simone; Pilati, Pierluigi; Da Pian, Pierpaolo; Forlin, Marco; Corazzina, Susanna; Rossi, Carlo Riccardo; Innocente, Federico; Ori, Carlo; Casara, Dario; Ujka, Francesca; Nitti, Donato; Lise, Mario

2007-02-01

In the present work, we report on the results of our pilot study of hyperthermic isolated hepatic perfusion (IHP) with melphalan alone for patients with unresectable metastatic liver tumors refractory to conventional treatments, with particular regard to the correlation between pharmacokinetic findings and hepatic toxicity. Inclusion criteria were unresectable liver metastases, hepatic parenchyma replacement liver function, and previous failure of at least one conventional treatment. IHP was performed under hyperthermic conditions with melphalan (1.5 mg/kg body weight). Completeness of vascular isolation of the liver and drug distribution volumes of the perfusion circuit were assessed by a radiolabeled albumin-based method. Drug concentrations in perfusate and plasma were measured by means of high-performance liquid chromatography (HPLC). Twenty patients with unresectable liver metastases underwent IHP. No intraoperative mortality occurred. Treatment-related systemic toxicity was minimal and reversible. Three patients (15%) experienced grade 4 hepatic toxicity and died due to liver failure and subsequent multiorgan failure. Other six patients had significant (grade 3-4) but transitory hepatic toxicity. Complete and partial responses were observed in three and nine out of 17 evaluable patients, respectively (overall response rate = 70%). The pharmacokinetics study showed a 3% mean perfusate-to-plasma drug leakage (range 1-6%). Logistic regression analysis showed that drug concentration in the perfusate circuit, but not preoperative tests, significantly and independently correlated with hepatic toxicity (P = 0.028). Following melphalan-based IHP, objective tumor regression could be observed in a remarkable percentage of patients refractory to standard treatments. However, hepatic toxicity and related mortality were significant. Our findings suggest that drug dosage personalization based on the measurement of drug distribution volumes might minimize

Machine Perfusion of Porcine Livers with Oxygen-Carrying Solution Results in Reprogramming of Dynamic Inflammation Networks

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David Sadowsky

2016-11-01

Full Text Available Background: Ex vivo machine perfusion (MP can better preserve organs for transplantation. We have recently reported on the first application of a MP protocol in which liver allografts were fully oxygenated, under dual pressures and subnormothermic conditions, with a new hemoglobin-based oxygen carrier solution specifically developed for ex vivo utilization. In those studies, MP improved organ function post-operatively and reduced inflammation in porcine livers. Herein, we sought to refine our knowledge regarding the impact of MP by defining dynamic networks of inflammation in both tissue and perfusate. Methods: Porcine liver allografts were preserved either with MP (n = 6 or with cold static preservation (CSP; n = 6, then transplanted orthotopically after 9 h of preservation. Fourteen inflammatory mediators were measured in both tissue and perfusate during liver preservation at multiple time points, and analyzed using Dynamic Bayesian Network (DyBN inference to define feedback interactions, as well as Dynamic Network Analysis (DyNA to define the time-dependent development of inflammation networks.Results: Network analyses of tissue and perfusate suggested an NLRP3 inflammasome-regulated response in both treatment groups, driven by the pro-inflammatory cytokine interleukin (IL-18 and the anti-inflammatory mediator IL-1 receptor antagonist (IL-1RA. Both DyBN and DyNA suggested a reduced role of IL-18 and increased role of IL-1RA with MP, along with increased liver damage with CSP. DyNA also suggested divergent progression of responses over the 9 h preservation time, with CSP leading to a stable pattern of IL-18-induced liver damage and MP leading to a resolution of the pro-inflammatory response. These results were consistent with prior clinical, biochemical, and histological findings after liver transplantation. Conclusion: Our results suggest that analysis of dynamic inflammation networks in the setting of liver preservation may identify novel

Influence of dietary casein or lactalbumin on incorporation of 14C leucine into protein of ethanol-perfused livers of rats

International Nuclear Information System (INIS)

James, K.A.C.; Treloar, B.P.; Hove, E.L.; Sedcole, J.R.

1983-01-01

Rats were fed diets containing casein or lactalbumin as the sole source of protein (c. 200 g protein/kg diet) for about 4 weeks. At 190-210 g live weight the rats were anaesthetised, and the livers were perfused with ethanol (0-3.7 mL/100 mL perfusate, i.e., 0-625 m ) and 30 minutes later with 14 C leucine (5 micro g Ci) for 60 minutes. The specific radioactivity (dpm/mg protein) of liver and perfusate protein was determined. The log specific radioactivity data of each dietary group were described by a 2-phase linear model: a constant or plateau level up to an ethanol concentration of c. 2 mL ethanol/100 mL perfusate (340 m ), and a linear decrease in log specific radioactivity above that level. For the liver protein the constant log specific radioactivity of the casein dietary group was significantly higher than that for the lactalbumin dietary group. The decreases in log specific radioactivity for both liver and perfusate in the casein dietary group were significantly greater than those in the lactalbumin dietary group. The dietary dependent difference in incorporation with varying ethanol concentrations may result from a combination of control over liver protein synthesis and protein secretion. Predisposing rats to 2 high-quality protein diets results in differences in liver protein metabolism which are maintained against a wide range of ethanol perfusate concentrations. (auths)

Development of a new extracorporeal whole-liver perfusion system.

Science.gov (United States)

Naruse, Katsutoshi; Sakai, Yasuyuki; Guo, Lei; Natori, Takeshi; Shindoh, Junichi; Karasawa, Yasuaki; Iida, Yuhki; Kojima, Kentaro; Michishita, Kazuya; Makuuchi, Masatoshi

2003-01-01

We have developed a new extracorporeal whole-liver accommodation device in which a whole swine liver is placed in a physiological state by modeling the intraabdominal arrangement in the pig body, with the liver supported by a special inferior vena cava tube. Furthermore, we employed a diaphragm-type artificial heart in our system to produce pulsatile blood flow through the hepatic artery, which is considered to be indispensable to dilate peripheral vessels and supply oxygenated whole blood to the peripheral liver tissue. Beneficial effects were demonstrated in visual findings and bile juice secretion. The color of the liver surface in our system remained bright red, indicating that the liver vessels were well drained and free from congestion, and bile juice secretion was maintained at more than 10 ml/h throughout the perfusion period. Our system exhibited excellent ammonia removal and urea nitrogen synthesis, and serum aspartate aminotransferase levels showed no increase, indicating the absence of hepatocyte destruction. Histological findings showed that the liver could expand appropriately and was free from compression caused by its own weight. In conclusion, our original liver accommodation device enabled appropriate expansion of the whole liver and supplied adequate oxygenated blood to peripheral areas by means of a pulsatile pump.

Double-Balloon Catheter for Isolated Liver Perfusion: An Experimental Study

International Nuclear Information System (INIS)

Cwikiel, Wojciech; Bergqvist, Lennart; Harnek, Jan

2001-01-01

Purpose: Further development of a previously described interventional method for isolated liver perfusion (ILP) with a new double-lumen balloon catheter, and evaluation of the side-effects of such isolation.Methods: In six pigs a double-balloon occlusion catheter was placed via the transjugular approach with its tip in the portal vein. One of the balloons was positioned in the inferior vena cava (IVC), cranial to the origin of the hepatic veins and the other balloon in the portal vein. By the transfemoral approach, a single-balloon occlusion catheter was placed in the IVC caudal to the origin of the hepatic veins. A third catheter was placed by the transfemoral route with the occlusion balloon in the proper hepatic artery. After inflation of all balloons 99 Tc m -labelled human serum albumin was recirculated through the liver. The isolation was evaluated by repeated measurement of radioactivity levels in peripheral blood. Laboratory tests of liver and pancreas function, and hemoglobin, were taken before, at the end of, and 3 days after the procedure. Blood gases were tested at the beginning and end of the procedure.Results: One pig died during the procedure due to technical failure and was excluded from the study. In the other pigs leakage from the isolated liver to the systemic circulation increased slowly, up to 9.7% (mean) during 30 min of recirculation of the perfusate through the liver. Laboratory tests were normal in all pigs except insignificant acidosis directly after the procedure and the slight elevation of s-ALAT after 3 days.Conclusions: Only minor leakage from the liver to the systemic circulation was noted during ILP performed with a new, double-balloon catheter. There were no serious side effects

Inhibition of gluconeogenesis in the perfusing liver of irradiated rats

International Nuclear Information System (INIS)

Borovikova, G.V.; Dokshina, G.A.; Ermakova, G.N.; Mashkova, N.Yu.

1981-01-01

It was shown on the perfusing liver taken from rats on the 1st and 3d days after irradiation in a dose of 18.06x10 -2 C/kg that insulin (400 μunits/ml) and taurine (40 mg%) exerted an inhibiting action on the rate of gluconeogenesi.s and transamination, catalyzed by alanine aminoferase and aspartate aminoferase, in a soluble fraction of the irradiated rat liver. The gluconeogenic capacity and the reactivity of the isolated organ were shown to decrease on the 3d day after irradiation [ru

Liver fat content in type 2 diabetes: relationship with hepatic perfusion and substrate metabolism

NARCIS (Netherlands)

Rijzewijk, Luuk J.; van der Meer, Rutger W.; Lubberink, Mark; Lamb, Hildo J.; Romijn, Johannes A.; de Roos, Albert; Twisk, Jos W.; Heine, Robert J.; Lammertsma, Adriaan A.; Smit, Johannes W. A.; Diamant, Michaela

2010-01-01

Hepatic steatosis is common in type 2 diabetes. It is causally linked to the features of the metabolic syndrome, liver cirrhosis, and cardiovascular disease. Experimental data have indicated that increased liver fat may impair hepatic perfusion and metabolism. The aim of the current study was to

EFFECT OF ETHANOL ON HEPATOBILIARY TRANSPORT OF CATIONIC DRUGS - A STUDY IN THE ISOLATED-PERFUSED RAT-LIVER, RAT HEPATOCYTES AND RAT MITOCHONDRIA

NARCIS (Netherlands)

STEEN, H; MEIJER, DKF; Merema, M.T.

The effect of ethanol on the hepatic uptake of various cationic drugs was studied in isolated perfused rat livers, isolated rat hepatocytes and isolated rat liver mitochondria. In isolated rat hepatocytes and in isolated perfused rat livers, the uptake of the model organic cation

The Hepatoprotective Effects of Corn Silk against Dose-induced Injury of Ecstasy (MDMA Using Isolated Rat Liver Perfusion System

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Mohammad Karami

2016-07-01

Full Text Available Background: Corn silk (CS is widely used in Iranian traditional medicine. The aim of this study was to investigate hepatoprotective activity of CS by Isolated Rat Liver Perfusion System (IRLP. Methods: Hydro-alcoholic extract of corn silk (10, 20, 40, and 100 mg kg-1 was evaluated for its hepatoprotective activity by IRLP. Phenol and flavonoid contents of the extract were determined as gallic acid and quercetin equivalents from a calibration curve, respectively. IRLP system is ideal for studying biochemical alterations of chemicals with minimum neuro-hormonal effects. In this study, the liver was perfused with Kerbs-Henseleit buffer, containing different concentration of hydro-alcoholic extract of corn silk (10, 20, 40, 50,100mg/kg, added to the buffer, and perfused for 2 hours. During the perfusion, many factors, including amino-transferees activities and the level of GSH, were assessed as indicators of liver viability. Consequently, sections of liver tissues were examined for any histopathological changes. Results: Histopathological changes in liver tissues were related to hydro-alcoholic extract of corn silk concentrations in a dose-dependent manner. Also, 50 and 100mg/kg doses caused significant (P<0.05 histopathological changes. Level of GSH in samples perfused with hydro-alcoholic extract increased compared to the control group. Conclusion: Hepatoprotective effect of CS is due to decreased lipid peroxidation, although other mechanisms might also be involved.

The estimation of the liver perfusion in cirrhosis and liver tumours by radionuclide angiography

International Nuclear Information System (INIS)

Artiko, V.; Obradovic, V.; Kostic, K.; Petrovic, M.; Davidovic, B.; Perisic-Savic, M.; Janosevic, S.

2004-01-01

Purpose: The aim of the study is assessment of the hepatic perfusion index (HPI) in cirrhosis and focal liver diseases. Methods: Hepatic radionuclide angiography (HRA) was performed with bolus injection of 740 MBq- 99m-Tc-pertechnetate, during one minute (If/sec), using gamma camera, in 10 controls, 35 cirrhotic patients and 34 patients with different liver tumors. Results: In 10 controls (C), HPI was 0.68+/-0.06; it was significantly decreased (p 0.05), HPI values were significantly lower in LCEV (p 0.05).In 22 patients with liver hemangiomas (LH, X= 0.64 +/-0.08) HPI values were physiological (C-LH, p>0.05). However, in 4 patients with hepatocellular carcinoma (H, X=0.26+/-0.20), and 8 with liver metastases (LM, X=0.40 +/-0.28), HPI values were significantly decreased (p 0.05). Conclusion: HRA is a useful method for the asessment of different degrees of hemodynamic alterations in portal system, as well as for differential diagnosis of benign and malignant liver tumors. (authors)

Liver perfusion scintigraphy prior to and after transjugular intrahepatic portosystemic shunts (TIPS) in patients with portal hypertension

International Nuclear Information System (INIS)

Willkomm, P.; Schomburg, A.; Reichmann, K.; Bangard, M.; Overbeck, B.; Biersack, H.J.; Brensing, K.A.; Sauerbruch, T.

2000-01-01

Purpose: This investigation was performed to compare the hemodynamic results of the transjugular intrahepatic portosystemic shunt, a new interventional treatment for portal hypertension, with those observed after the established surgical shunt interventions. Methods: We examined 22 patients with portal hypertension due to liver cirrhosis before and after elective TIPS by liver perfusion scintigraphy. The relative portal perfusion was determined before and after the shunt procedure. Additionally, we measured the portal pressure gradient (PPG: Portal-central venous pressure, mmHg). Results: Prior to TIPS, the relative portal perfusion was significantly reduced to 22±9.1%. After the intervention we calculated values of 23.1±10.7% in the TIPS-group (p=0.67; not significant). In spite of unchanged portal perfusion, the portal pressure was significantly (p [de

Normothermic Versus Hypothermic Heart Surgery: Evaluation of Post-Operative Complications

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H Akhlagh

2012-04-01

Full Text Available Introduction: The recently introduced technique of warm heart surgery may be a very effective method of myocardial protection. Although the systemic effects of hypothermic cardiopulmonary bypass are well known, the effects of warm heart surgery are not. Methods: In a prospective trial, 60 patients undergoing an elective coronary artery bypass grafting were randomly allocated to normothermic(30 patients and hypothermic(30 patients group and assessments regarding renal, respiratory and neurologic complications and bleeding volume was done. Resulst: Eighty percent of hypothermic group and 86% of normothermic group were males (p=0/36. Mean age was 56.4 and 56.1 years in hypothermic and normothermic groups, respectively. Groups had similar central temperature, shivering, nipride usage, intake and output, bleeding volume, neurologic complications and ICU staying(p>0/05 but inotrop usage and incidence of phrenic nerve palsy were higher in hypothermic group(p<0/05. Conclusion: Hypothermic procedure leads to a lower rate of respiratory complications, therefore we recommend replacing hypothermic procedure by normothermic one.

Multiple-indicator dilution technique for characterization of normal and retrograde flow in once-through rat liver perfusions

International Nuclear Information System (INIS)

St-Pierre, M.V.; Schwab, A.J.; Goresky, C.A.; Lee, W.F.; Pang, K.S.

1989-01-01

The technique of normal and retrograde rat liver perfusion has been widely used to probe zonal differences in drug-metabolizing activities. The validity of this approach mandates the same tissue spaces being accessed by substrates during both normal and retrograde perfusions. Using the multiple-indicator dilution technique, we presently examine the extent to which retrograde perfusion alters the spaces accessible to noneliminated references. A bolus dose of 51Cr-labeled red blood cells, 125I-albumin, 14C-sucrose and 3H2O was injected into the portal (normal) or hepatic (retrograde) vein of rat livers perfused at 10 ml per min per liver. The outflow perfusate was serially collected over 220 sec to characterize the transit times and the distribution spaces of the labels. During retrograde perfusion, red blood cells, albumin and sucrose profiles peaked later and lower than during normal perfusion, whereas the water curves were similar. The transit times of red blood cells, albumin and sucrose were longer (p less than 0.005), whereas those for water did not change. Consequently, retrograde flow resulted in significantly larger sinusoidal blood volumes (45%), albumin Disse space (42%) and sucrose Disse space (25%) than during normal flow, whereas the distribution spaces for total and intracellular water remained unaltered. The distension of the vascular tree was confirmed by electron microscopy, by which occasional isolated foci of widened intercellular recesses and spaces of Disse were observed. Cellular ultrastructure was otherwise unchanged, and there was no difference found between normal and retrograde perfusion for bile flow rates, AST release, perfusion pressure, oxygen consumption and metabolic removal of ethanol, a substrate with flow-limited distribution, which equilibrates rapidly with cell water (hepatic extraction ratios were virtually identical: normal vs. retrograde, 0.50 vs. 0.48 at 6 to 7.4 mM input concentration)

Isolated Liver Perfusion Using Percutaneous Methods:[ql An Experimental Study in the Pig

International Nuclear Information System (INIS)

Harnek, Jan; Cwikiel, Wojciech; Bergqvist, Lennart; Persson, Bo; Stridbeck, Hans

1996-01-01

Purpose: To develop a method for isolated perfusion of the liver using radiological methods. Methods: Twenty-one pigs, weighing about 20 kg, were divided into three groups. By transjugular and transfemoral approaches two occlusion balloons were placed in the inferior vena cava cranial and caudal, respectively, to the origin of the hepatic veins. One occlusion balloon was placed transfemorally in the common hepatic artery. Another occlusion balloon was inserted in the main branch of the portal vein via the transjugular-transhepatic approach in 11 pigs (groups 1 and 2), and in 10 pigs (group 3) by a percutaneous transhepatic route. After inflation of the balloons, patency of the isolated liver circulation was evaluated by recirculation of 99 Tc m -labelled human albumin during 30 min. Blood tests were obtained after 1, 3, 5, 10, 15, and 30 min to evaluate leakage from the liver to the systemic circulation. Results: Increasing leakage to the systemic circulation from the isolated liver circulation was observed in groups 1 and 2. In the third group the leakage was less than 10%. Conclusion: In an experimental animal model, isolated perfusion of the liver with minor leakage to the systemic circulation may be achieved using radiological methods

Arterio-portal shunts in the cirrhotic liver: perfusion computed tomography for distinction of arterialized pseudolesions from hepatocellular carcinoma

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Fischer, Michael A. [University Hospital Zurich, Department of Diagnostic and Interventional Radiology, Zurich (Switzerland); Karolinska Institutet, Division of Medical Imaging and Technology. Department of Clinical Science, Intervention and Technology (CLINTEC), Stockholm (Sweden); Marquez, Herman P.; Gordic, Sonja; Alkadhi, Hatem [University Hospital Zurich, Department of Diagnostic and Interventional Radiology, Zurich (Switzerland); Leidner, Bertil; Aspelin, Peter; Brismar, Torkel B. [Karolinska Institutet, Division of Medical Imaging and Technology. Department of Clinical Science, Intervention and Technology (CLINTEC), Stockholm (Sweden); Klotz, Ernst [Computed Tomography and Radiation Oncology, Siemens Healthcare, Forchheim (Germany)

2017-03-15

To determine perfusion computed tomography (P-CT) findings for distinction of arterial pseudolesions (APL) from hepatocellular carcinoma (HCC) in the cirrhotic liver. 32 APL and 21 HCC in 20 cirrhotic patients (15 men; 65 ± 10 years), who underwent P-CT for evaluation of HCC pre- (N = 9) or post- (N = 11) transarterial chemoembolization, were retrospectively included using CT follow-up as the standard of reference. All 53 lesions were qualitatively (visual) and quantitatively (perfusion parameters) analysed according to their shape (wedge, irregular, nodular), location (not-/adjunct to a fistula), arterial liver perfusion (ALP), portal venous liver perfusion (PLP), hepatic perfusion index (HPI). Accuracy for diagnosis of HCC was determined using receiver operating characteristics. 18/32 (56 %) APL were wedge shaped, 10/32 (31 %) irregular and 4/32 (12 %) nodular, while 11/21 (52 %) HCC were nodular or 10/21 (48 %) irregular, but never wedge shaped. Significant difference between APL and HCC was seen for lesion shape in pretreated lesions (P < 0.001), and for PLP and HPI in both pre- and post-treated lesions (all, P < 0.001). Diagnostic accuracy for HCC was best for combined assessment of lesion configuration and PLP showing an area under the curve of 0.901. Combined assessment of lesion configuration and portal venous perfusion derived from P-CT allows best to discriminate APL from HCC with high diagnostic accuracy. (orig.)

Liver transplantation from Maastricht category 2 non-heart-beating donors.

Science.gov (United States)

Otero, Alejandra; Gómez-Gutiérrez, Manuel; Suárez, Francisco; Arnal, Francisco; Fernández-García, Antón; Aguirrezabalaga, Javier; García-Buitrón, José; Alvarez, Joaquín; Máñez, Rafael

2003-10-15

The demand for liver transplantation has increasingly exceeded the supply of cadaver donor organs. Non-heart-beating donors (NHBDs) may be an alternative to increase the cadaver donor pool. The outcome of 20 liver transplants from Maastricht category 2 NHBDs is compared with 40 liver transplants from heart-beating donors (HBDs). After unsuccessful cardiopulmonary resuscitation (CPR), cardiopulmonary support (CPS) with simultaneous application of chest and abdominal compression (n=6), and cardiopulmonary bypass (CPB; n=14), which was hypothermic (n=7) or normothermic (n=7), were used to preserve the organs from NHBDs. Factors that may influence the outcome of livers from Maastricht category 2 NHBDs were also investigated. With a minimum follow-up of 2 years, actuarial patient and graft survivals with livers from Maastricht category 2 NHBDs were 80% and 55%, respectively. Transplantation of organs from these donors was associated with a significantly higher incidence of primary nonfunction, biliary complications, and more severe initial liver dysfunction compared with livers from HBDs. Graft survival was 83% in livers from NHBDs preserved with CPS and 42% in those maintained with CPB. No graft failed if the duration of warm ischemia did not exceed 130 min with CPR or CPS, and if the period of CPB did not surpass 150 min when this method was used after CPR, regardless if it was hypothermic or normothermic. Livers from Maastricht type 2 NHBDs may be used for transplantation if the period of warm ischemia during CPR or CPS does not exceed 130 min. Hypothermic or normothermic CPB after CPR preserves liver viability for an additional 150 min.

Biosynthesis of agmatine in isolated mitochondria and perfused rat liver: studies with 15N-labelled arginine

Science.gov (United States)

2005-01-01

An important but unresolved question is whether mammalian mitochondria metabolize arginine to agmatine by the ADC (arginine decarboxylase) reaction. 15N-labelled arginine was used as a precursor to address this question and to determine the flux through the ADC reaction in isolated mitochondria obtained from rat liver. In addition, liver perfusion system was used to examine a possible action of insulin, glucagon or cAMP on a flux through the ADC reaction. In mitochondria and liver perfusion, 15N-labelled agmatine was generated from external 15N-labelled arginine. The production of 15N-labelled agmatine was time- and dose-dependent. The time-course of [U-15N4]agmatine formation from 2 mM [U-15N4]arginine was best fitted to a one-phase exponential curve with a production rate of approx. 29 pmol·min−1·(mg of protein)−1. Experiments with an increasing concentration (0– 40 mM) of [guanidino-15N2]arginine showed a Michaelis constant Km for arginine of 46 mM and a Vmax of 3.7 nmol·min−1·(mg of protein)−1 for flux through the ADC reaction. Experiments with broken mitochondria showed little changes in Vmax or Km values, suggesting that mitochondrial arginine uptake had little effect on the observed Vmax or Km values. Experiments with liver perfusion demonstrated that over 95% of the effluent agmatine was derived from perfusate [guanidino-15N2]arginine regardless of the experimental condition. However, the output of 15N-labelled agmatine (nmol·min−1·g−1) increased by approx. 2-fold (P<0.05) in perfusions with cAMP. The findings of the present study provide compelling evidence that mitochondrial ADC is present in the rat liver, and suggest that cAMP may stimulate flux through this pathway. PMID:15656789

Time-resolved computed tomography of the liver: retrospective, multi-phase image reconstruction derived from volumetric perfusion imaging

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Fischer, Michael A.; Kartalis, Nikolaos; Aspelin, Peter; Albiin, Nils; Brismar, Torkel B. [Karolinska University Hospital, Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, Stockholm (Sweden); Leidner, Bertil; Svensson, Anders [Karolinska University Hospital, Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, Stockholm (Sweden); Karolinska University Hospital Huddinge, Department of Radiology, Stockholm (Sweden)

2014-01-15

To assess feasibility and image quality (IQ) of a new post-processing algorithm for retrospective extraction of an optimised multi-phase CT (time-resolved CT) of the liver from volumetric perfusion imaging. Sixteen patients underwent clinically indicated perfusion CT using 4D spiral mode of dual-source 128-slice CT. Three image sets were reconstructed: motion-corrected and noise-reduced (MCNR) images derived from 4D raw data; maximum and average intensity projections (time MIP/AVG) of the arterial/portal/portal-venous phases and all phases (total MIP/ AVG) derived from retrospective fusion of dedicated MCNR split series. Two readers assessed the IQ, detection rate and evaluation time; one reader assessed image noise and lesion-to-liver contrast. Time-resolved CT was feasible in all patients. Each post-processing step yielded a significant reduction of image noise and evaluation time, maintaining lesion-to-liver contrast. Time MIPs/AVGs showed the highest overall IQ without relevant motion artefacts and best depiction of arterial and portal/portal-venous phases respectively. Time MIPs demonstrated a significantly higher detection rate for arterialised liver lesions than total MIPs/AVGs and the raw data series. Time-resolved CT allows data from volumetric perfusion imaging to be condensed into an optimised multi-phase liver CT, yielding a superior IQ and higher detection rate for arterialised liver lesions than the raw data series. (orig.)

Disposition kinetics of diclofenac in the dual perfused rat liver.

Science.gov (United States)

Sahin, Selma; Rowland, Malcolm

2013-09-01

This study investigates the hepatic disposition of diclofenac as a function of route of input: portal vein (PV) versus hepatic artery (HA) in the presence of its binding protein, albumin. The in situ dual perfused rat liver was performed using Krebs bicarbonate buffer containing human serum albumin (HSA, 0.25%-1%) at constant PV (12 mL/min) and HA (3 mL/min) flow rates. Bolus doses of [(14) C]-diclofenac and (125) I-labeled HSA were injected randomly into the HA or PV and then, after an appropriate interval, into the alternate vessel. Regardless of route of input and perfusion medium protein concentration, the hepatic outflow profile of diclofenac displayed a characteristic sharp peak followed by a slower eluting tail, indicating that its radial distribution is not instantaneous. Based on the estimated effective permeability-surface area product/blood flow ratio, hepatic uptake of diclofenac is governed by both perfusion and permeability. Fractional effluent recovery (F) increased as unbound diclofenac fraction in the perfusate decreased. Although no significant difference in hepatic clearance of diclofenac as a function of route of delivery at 0.5% and 1% HSA, it was demonstrable at 0.25% HSA (p < 0.001), when the extraction ratio is higher. Copyright © 2013 Wiley Periodicals, Inc.

Control of ketogenesis in the perfused rat liver by the sympathetic innervation

NARCIS (Netherlands)

Beuers, U.; BECKH, K.; JUNGERMANN, K.

1986-01-01

The regulation of ketogenesis by the hepatic nerves was investigated in the rat liver perfused in situ. Electrical stimulation of the hepatic nerves around the portal vein and the hepatic artery caused a reduction of basal ketogenesis owing to a decrease in acetoacetate release to 30% with

Cold storage of liver microorgans in ViaSpan and BG35 solutions: study of ammonia metabolism during normothermic reoxygenation.

Science.gov (United States)

Pizarro, María Dolores; Mediavilla, María Gabriela; Berardi, Florencia; Tiribelli, Claudio; Rodríguez, Joaquín V; Mamprin, María Eugenia

2014-01-01

This work focuses on ammonia metabolism of Liver Microorgans (LMOs) after cold preservation in a normothermic reoxygenation system (NRS). We have previously reported the development of a novel preservation solution, Bes-Gluconate-PEG 35 kDa (BG35) that showed the same efficacy as ViaSpan to protect LMOs against cold preservation injury. The objective of this work was to study mRNA levels and activities of two key Urea Cycle enzymes, Carbamyl Phosphate Synthetase I (CPSI) and Ornithine Transcarbamylase (OTC), after preservation of LMOs in BG35 and ViaSpan and the ability of these tissue slices to detoxify an ammonia overload in a NRS model. After 48 h of cold storage (0°C in BG35 or ViaSpan) LMOs were rewarmed in KHR containing an ammonium chloride overload (1 mM). We determined ammonium detoxification capacity (ADC), urea synthesis and enzyme activities and relative mRNA levels for CPSI and OTC. At the end of reoxygenation LMOs cold preserved in BG35 have ADC and urea synthesis similar to controls. ViaSpan group demonstrated a lower capacity to detoxify ammonia and to synthesize urea than fresh LMOs during the whole reoxygenation period which correlated with the lower mRNA levels and activities for CPSI and OTC observed for this group. We demonstrate that our preservation conditions (48 hours, BG35 solution, anoxia, 0ºC) did not affect ammonia metabolism of cold preserved LMOs maintaining the physiological and biochemical liver functions tested, which allows their future use as biological component of a BAL system.

Microscale 3D Liver Bioreactor for In Vitro Hepatotoxicity Testing under Perfusion Conditions

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Nora Freyer

2018-03-01

Full Text Available The accurate prediction of hepatotoxicity demands validated human in vitro models that can close the gap between preclinical animal studies and clinical trials. In this study we investigated the response of primary human liver cells to toxic drug exposure in a perfused microscale 3D liver bioreactor. The cellularized bioreactors were treated with 5, 10, or 30 mM acetaminophen (APAP used as a reference substance. Lactate production significantly decreased upon treatment with 30 mM APAP (p < 0.05 and ammonia release significantly increased in bioreactors treated with 10 or 30 mM APAP (p < 0.0001, indicating APAP-induced dose-dependent toxicity. The release of prostaglandin E2 showed a significant increase at 30 mM APAP (p < 0.05, suggesting an inflammatory reaction towards enhanced cellular stress. The expression of genes involved in drug metabolism, antioxidant reactions, urea synthesis, and apoptosis was differentially influenced by APAP exposure. Histological examinations revealed that primary human liver cells in untreated control bioreactors were reorganized in tissue-like cell aggregates. These aggregates were partly disintegrated upon APAP treatment, lacking expression of hepatocyte-specific proteins and transporters. In conclusion, our results validate the suitability of the microscale 3D liver bioreactor to detect hepatotoxic effects of drugs in vitro under perfusion conditions.

Microscale 3D Liver Bioreactor for In Vitro Hepatotoxicity Testing under Perfusion Conditions.

Science.gov (United States)

Freyer, Nora; Greuel, Selina; Knöspel, Fanny; Gerstmann, Florian; Storch, Lisa; Damm, Georg; Seehofer, Daniel; Foster Harris, Jennifer; Iyer, Rashi; Schubert, Frank; Zeilinger, Katrin

2018-03-15

The accurate prediction of hepatotoxicity demands validated human in vitro models that can close the gap between preclinical animal studies and clinical trials. In this study we investigated the response of primary human liver cells to toxic drug exposure in a perfused microscale 3D liver bioreactor. The cellularized bioreactors were treated with 5, 10, or 30 mM acetaminophen (APAP) used as a reference substance. Lactate production significantly decreased upon treatment with 30 mM APAP ( p < 0.05) and ammonia release significantly increased in bioreactors treated with 10 or 30 mM APAP ( p < 0.0001), indicating APAP-induced dose-dependent toxicity. The release of prostaglandin E2 showed a significant increase at 30 mM APAP ( p < 0.05), suggesting an inflammatory reaction towards enhanced cellular stress. The expression of genes involved in drug metabolism, antioxidant reactions, urea synthesis, and apoptosis was differentially influenced by APAP exposure. Histological examinations revealed that primary human liver cells in untreated control bioreactors were reorganized in tissue-like cell aggregates. These aggregates were partly disintegrated upon APAP treatment, lacking expression of hepatocyte-specific proteins and transporters. In conclusion, our results validate the suitability of the microscale 3D liver bioreactor to detect hepatotoxic effects of drugs in vitro under perfusion conditions.

Determination of liver and spleen perfusion by quantitative sequential scintigraphy: results in normal subjects and in patients with portal hypertension

International Nuclear Information System (INIS)

Biersack, H.J.; Torres, J.; Thelen, M.; Monzon, O.; Winkler, C.

1981-01-01

Quantitative sequential hepatosplenic scintigraphy was performed to determine the arterial and portal components of the total liver circulation in 135 patients (no liver disease in 20, liver cirrhosis and portal ;hypertension in 115). Portal circulation in healthy patients is calculated to be 70.4 +/- 6.2% of the total liver blood flow, whereas patients with portal hypertension showed a clear reduction of portal perfusion to 20.2 +/- 10.9%. Thirteen of 20 patients having portosystemic shunt surgery showed no portal perfusion. This new, noninvasive diagnostic technique yields vital information particularly useful in ;the surgical evaluation of portal hypertension. Other indications are also discussed

Feasibility of 4D perfusion CT imaging for the assessment of liver treatment response following SBRT and sorafenib

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Catherine Coolens, PhD

2016-07-01

Conclusions: The proposed methodology demonstrated feasibility of evaluating spatiotemporal changes in liver tumor perfusion and normal liver function following antiangiogenic therapy and radiation treatment warranting further evaluation of biomarker prognostication.

CT Perfusion for Early Response Evaluation of Radiofrequency Ablation of Focal Liver Lesions: First Experience

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Marquez, Herman P., E-mail: hermanpaulo.marquezmasquiaran@usz.ch; Puippe, Gilbert; Mathew, Rishi Philip; Alkadhi, Hatem; Pfammatter, Thomas; Fischer, Michael A. [University Hospital Zurich, Department of Diagnostic and Interventional Radiology, Institute of Diagnostic and Interventional Radiology (Switzerland)

2017-01-15

PurposeTo investigate the value of perfusion CT (P-CT) for early assessment of treatment response in patients undergoing radiofrequency ablation (RFA) of focal liver lesions.Methods and Materials20 consecutive patients (14 men; mean age 64 ± 14) undergoing P-CT within 24 h after RFA of liver metastases (n = 10) or HCC (n = 10) were retrospectively included. Two readers determined arterial liver perfusion (ALP, mL/min/100 mL), portal liver perfusion (PLP, mL/min/100 mL), and hepatic perfusion index (HPI, %) in all post-RFA lesions by placing a volume of interest in the necrotic central (CZ), the transition (TZ), and the surrounding parenchymal (PZ) zone. Patients were classified into complete responders (no residual tumor) and incomplete responders (residual/progressive tumor) using imaging follow-up with contrast-enhanced CT or MRI after a mean of 57 ± 30 days. Prediction of treatment response was evaluated using the area under the curve (AUC) from receiver operating characteristic analysis.ResultsMean ALP/PLP/HPI of both readers were 4.8/15.4/61.2 for the CZ, 9.9/16.8/66.3 for the TZ and 20.7/29.0/61.8 for the PZ. Interreader agreement of HPI was fair for the CZ (intraclass coefficient 0.713), good for the TZ (0.813), and excellent for the PZ (0.920). For both readers, there were significant differences in HPI of the CZ and TZ between responders and nonresponders (both, P < 0.05). HPI of the TZ showed the highest AUC (0.911) for prediction of residual tumor, suggesting a cut-off value of 76 %.ConclusionIncreased HPI of the transition zone assessed with P-CT after RFA might serve as an early quantitative biomarker for residual tumor in patients with focal liver lesions.

Normothermic liver preservation : a new paradigm?

NARCIS (Netherlands)

Ravikumar, Reena; Leuvenink, Henri; Friend, Peter J.

Despite increasing donor numbers, waiting lists and pre-transplant mortality continue to grow in many countries. The number of donor organs suitable for liver transplantation is restricted by cold preservation and ischemia-reperfusion injury (IRI). Transplantation of marginal donor organs has led to

Inhibition of mirtazapine metabolism by Ecstasy (MDMA) in isolated perfused rat liver model.

Science.gov (United States)

Jamshidfar, Sanaz; Ardakani, Yalda H; Lavasani, Hoda; Rouini, Mohammadreza

2017-06-28

Nowadays MDMA (3,4-methylendioxymethamphetamine), known as ecstasy, is widely abused among the youth because of euphoria induction in acute exposure. However, abusers are predisposed to depression in chronic consumption of this illicit compound. Mirtazapine (MRZ), an antidepressant agent, may be prescribed in MDMA-induced depression. MRZ is extensively metabolized in liver by CYP450 isoenzymes. 8-hydroxymirtazapine (8-OH) is mainly produced by CYP2D6. N-desmethylmirtazapine (NDES) is generated by CYP3A4. MDMA is also metabolized by the mentioned isoenzymes and demonstrates mechanism-based inhibition (MBI) in association with CYP2D6. Several studies revealed that MDMA showed inhibitory effects on CYP3A4. In the present study, our aim was to evaluate the impact of MDMA on the metabolism of MRZ in liver. Therefore, isolated perfused rat liver model was applied as our model of choice in this assessment. The subjects of the study were categorized into two experimental groups. Rats in the control group received MRZ-containing Krebs-Henselit buffer (1 μg/ml). Rats in the treatment group received aqueous solution of 1 mg/ml MDMA (3 mg/kg) intraperitoneally 1 hour before receiving MRZ. Perfusate samples were analyzed by HPLC. Analyses of perfusate samples showed 80% increase in the parent drug concentrations and 50% decrease in the concentrations of both metabolites in our treatment group compared to the control group. In the treatment group compared to the control group, AUC (0-120) of the parent drug demonstrated 50% increase and AUC (0-120) of 8-OH and NDES showed 70% and 60% decrease, respectively. Observed decrease in metabolic ratios were 83% and 79% for 8-OH and NDES in treatment group compared to control group, respectively. Hepatic clearance (CL h ) and intrinsic clearance (Cl int ) showed 20% and 60% decrease in treatment group compared to control group. All findings prove the inhibitory effects of ecstasy on both CYP2D6 and CYP3A4 hepatic isoenzymes. In

Hepatic perfusion changes in an experimental model of acute pancreatitis: Evaluation by perfusion CT

International Nuclear Information System (INIS)

Tutcu, Semra; Serter, Selim; Kaya, Yavuz; Kara, Eray; Nese, Nalan; Pekindil, Goekhan; Coskun, Teoman

2010-01-01

Purpose: It is known that acute pancreatitis may cause secondary changes in several organs. Liver is one of these involved organs. In different experimental studies hepatic damages were shown histopathologically in acute pancreatitis but there are a few studies about perfusion disorders that accompany these histopathologic changes. Perfusion CT (pCT) provides the ability to detect regional and global alterations in organ blood flow. The purpose of the study was to describe hepatic perfusion changes in experimental acute pancreatitis model with pCT. Materials and methods: Forty Sprague-Dawley rats of both genders with average weights of 250 g were used. Rats were randomized into two groups. Twenty rats were in control group and 20 in acute pancreatitis group. pCT was performed. Perfusion maps were formed by processing the obtained images with perfusion CT software. Blood flow (BF) and blood volume (BV) values were obtained from these maps. All pancreatic and liver tissues were taken off with laparotomy and histopathologic investigation was performed. Student's t test was used for statistical analyses. Results: In pCT we found statistically significant increase in blood volume in both lobes of liver and in blood flow in right lobe of the liver (p < 0.01). Although blood flow in left lobe of the liver increased, it did not reach statistical significance. Conclusion: The quantitative analysis of liver parenchyma with pCT showed that acute pancreatitis causes a significant perfusion changes in the hepatic tissue. Systemic mediators seem to be effective as well as local inflammatory changes in perfusion changes.

Hepatic perfusion changes in an experimental model of acute pancreatitis: Evaluation by perfusion CT

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Tutcu, Semra [Department of Surgery, Celal Bayar University, School of Medicine, Manisa (Turkey); Serter, Selim, E-mail: serterselim@gmail.co [Department of Radiology, Celal Bayar University, School of Medicine, Manisa (Turkey); Kaya, Yavuz; Kara, Eray [Department of Surgery, Celal Bayar University, School of Medicine, Manisa (Turkey); Nese, Nalan [Department of Pathology, Celal Bayar University, School of Medicine, Manisa (Turkey); Pekindil, Goekhan [Department of Radiology, Celal Bayar University, School of Medicine, Manisa (Turkey); Coskun, Teoman [Department of Surgery, Celal Bayar University, School of Medicine, Manisa (Turkey)

2010-08-15

Purpose: It is known that acute pancreatitis may cause secondary changes in several organs. Liver is one of these involved organs. In different experimental studies hepatic damages were shown histopathologically in acute pancreatitis but there are a few studies about perfusion disorders that accompany these histopathologic changes. Perfusion CT (pCT) provides the ability to detect regional and global alterations in organ blood flow. The purpose of the study was to describe hepatic perfusion changes in experimental acute pancreatitis model with pCT. Materials and methods: Forty Sprague-Dawley rats of both genders with average weights of 250 g were used. Rats were randomized into two groups. Twenty rats were in control group and 20 in acute pancreatitis group. pCT was performed. Perfusion maps were formed by processing the obtained images with perfusion CT software. Blood flow (BF) and blood volume (BV) values were obtained from these maps. All pancreatic and liver tissues were taken off with laparotomy and histopathologic investigation was performed. Student's t test was used for statistical analyses. Results: In pCT we found statistically significant increase in blood volume in both lobes of liver and in blood flow in right lobe of the liver (p < 0.01). Although blood flow in left lobe of the liver increased, it did not reach statistical significance. Conclusion: The quantitative analysis of liver parenchyma with pCT showed that acute pancreatitis causes a significant perfusion changes in the hepatic tissue. Systemic mediators seem to be effective as well as local inflammatory changes in perfusion changes.

Computed Tomography Perfusion of the liver: Assessment of Pure Portal Blood Flow Studied with CT Perfusion During Superior Mesenteric Arterial Portography

International Nuclear Information System (INIS)

Kojima, H.; Tanigawa, N.; Komemushi, A.; Kariya, S.; Sawada, S.

2004-01-01

Purpose: To quantitatively assess the portal component of hepatic blood flow using computed tomography (CT) perfusion studies during superior mesenteric arterial portography. Material and Methods: Thirty-four patients with hepatocellular carcinoma and liver cirrhosis (LC) and 13 patients with liver metastasis without chronic liver disease were enrolled in this study. Ten milliliters of a non-ionic contrast medium (150 mgI) was injected at a rate of 5 ml/s via a catheter placed in the superior mesenteric artery. Single-slice cine CT images at the level of the main trunk or the right/left main trunk of the portal vein were acquired over 40 s. The deconvolution method was then used on these CT images to measure blood flow (BF), blood volume (BV), and mean transit time (MTT) in (a) liver parenchyma in patients with HCC and liver cirrhosis; (b) liver parenchyma in patients with liver metastasis without cirrhosis; (c) directly in the HCC; and (d) directly in one of the metastases. Results: In 34 LC patients (a), BF, BV, and MTT in the liver parenchyma were 44.7±24.5 ml/min/100 g, 3.9±2.4 ml/100 g, and 10.9±5.5 s, respectively. In 13 patients without cirrhosis (b), BF, BV, and MTT in the liver parenchyma were 89.6±52.0 ml/min/100 g, 6.3 ±3.2 ml/100 g, and 8.7±3.6 sec, respectively. A significant difference in BF and BV was seen in patients with liver cirrhosis compared to those without cirrhosis. BF, BV, and MTT measured directly in HCC (c) were 6.5±4.5 ml/min/100 g, 0.4±0.4 ml/100 g, and 3.0±3.1 sec respectively, and BF, BV, and MTT in liver metastases (d) were 19.3 ± 21.7 ml/min/100 g, 0.6±0.8 ml/100 g, and 1.8±1.6 s, respectively. Conclusion: CT perfusion studies during superior mesenteric arterial portography allow quantitative assessment of pure portal blood flow in the liver

AMC-Bio-Artificial Liver culturing enhances mitochondrial biogenesis in human liver cell lines: The role of oxygen, medium perfusion and 3D configuration

NARCIS (Netherlands)

Adam, Aziza A. A.; van Wenum, Martien; van der Mark, Vincent A.; Jongejan, Aldo; Moerland, Perry D.; Houtkooper, Riekelt H.; Wanders, Ronald J. A.; Oude Elferink, Ronald P.; Chamuleau, Robert A. F. M.; Hoekstra, Ruurdtje

2017-01-01

Human liver cell lines, like HepaRG and C3A, acquire higher functionality when cultured in the AMC-Bio-Artificial Liver (AMC-BAL). The three main differences between BAL and monolayer culture are the oxygenation (40% vs 20%O2), dynamic vs absent medium perfusion and 3D vs 2D configuration. Here, we

Michaëlis--Menten kinetics of phenazone elimination in the perfused pig liver

DEFF Research Database (Denmark)

Andreasen, B; Tonnesen, K; Rabol, A

1977-01-01

The purpose of the present study was to define the elimination kinetics of phenazone (NFN) in the isolated perfused pig liver. In five experiments phenazone was administered as constant infusion to obtain steady-state periods over a wide range of concentrations. The elimination of phenazone follo...

Machine perfusion preservation of the pig liver using a new preservation solution, polysol

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Bessems, M.; Doorschodt, B. M.; Dinant, S.; de Graaf, W.; van Gulik, T. M.

2006-01-01

INTRODUCTION: The current gold standard for donor liver preservation is cold storage in a preservation solution (4 degrees C), such as Celsior or the University of Wisconsin solution (UW). Recent studies have suggested the benefits of machine perfusion (MP) over cold storage. To improve the results

CULTIVATION OF HUMAN LIVER CELLS AND ADIPOSE-DERIVED MESENCHYMAL STROMAL CELLS IN PERFUSION BIOREACTOR

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Yu. В. Basok

2018-01-01

Full Text Available Aim: to show the progress of the experiment of cultivation of human liver cells and adipose-derived mesenchymal stromal cells in perfusion bioreactor.Materials and methods. The cultivation of a cell-engineered construct, consisting of a biopolymer microstructured collagen-containing hydrogel, human liver cells, adipose-derived mesenchymal stromal cells, and William’s E Medium, was performed in a perfusion bioreactor.Results. On the 7th day large cells with hepatocyte morphology – of a polygonal shape and a centrally located round nucleus, – were present in the culture chambers of the bioreactor. The metabolic activity of hepatocytes in cell-engineered constructs was confi rmed by the presence of urea in the culture medium on the seventh day of cultivation in the bioreactor and by the resorption of a biopolymer microstructured collagen-containing hydrogel.

Normothermal or Hypothermal Extracorporeal Circulation Regimens in Patients with Acquired Heart Disease

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V. V. Lomivorotov

2013-01-01

Full Text Available Background. Hypothermal extracorporeal circulation has been used in cardiosurgery over 50 years. However, recent trials have not shown its predominant effect on the protection of the brain, lung, and myocardium in patients during surgery. We have presumed that when normothermal extracorporeal circulation used in patients with acquired heart disease, its pathophysiological effect on the body is comparable with that of hypothermal extracorporeal circulation. Subjects and methods. One hundred and forty patients who were to undergo acquired heart disease correction were randomized into two equal groups: that using hypothermal or normothermal extracorporeal circulation. Perioperative troponin I and NT-proBNP concentrations, postoperative clinical course, and hospital morbidity and mortality rates were estimated. Results. There were no significant differences in the concentrations of troponin I and NT-proBNP at the study stages. In the normothermal extracorporeal circulation group patients with isolated aortic stenosis, the concentration of troponin I was higher than that in the hypothermal extracorporeal circulation group. Analyzing the postoperative course indicated that the duration of mechanical ventilation was significantly lower in the hypothermal extracorporeal circulation group than in the normothermal extracorporeal circulation group. There were no differences in hospital complications and mortality rates. Conclusion. Hypothermal versus normothermal extracorporeal circulation in the correction of acquired heart diseases has no predominant effect on tro-ponin I and NT-proBNP concentrations, postoperative clinical course, and hospital complications and mortality rates. Key words: extracorporeal circulation, hypothermia, acquired heart disease, troponin I, NT-proBNP.

Glucose phosphorylation is not rate limiting for accumulation of glycogen from glucose in perfused livers from fasted rats

International Nuclear Information System (INIS)

Youn, J.H.; Ader, M.; Bergman, R.N.

1989-01-01

Incorporation of Glc and Fru into glycogen was measured in perfused livers from 24-h fasted rats using [6-3H]Glc and [U-14C]Fru. For the initial 20 min, livers were perfused with low Glc (2 mM) to deplete hepatic glycogen and were perfused for the following 30 min with various combinations of Glc and Fru. With constant Fru (2 mM), increasing perfusate Glc increased the relative contribution of Glc carbons to glycogen (7.2 +/- 0.4, 34.9 +/- 2.8, and 59.1 +/- 2.7% at 2, 10, and 20 mM Glc, respectively; n = 5 for each). During perfusion with substrate levels seen during refeeding (10 mM Glc, 1.8 mumol/g/min gluconeogenic flux from 2 mM Fru), Fru provided 54.7 +/- 2.7% of the carbons for glycogen, while Glc provided only 34.9 +/- 2.8%, consistent with in vivo estimations. However, the estimated rate of Glc phosphorylation was at least 1.10 +/- 0.11 mumol/g/min, which exceeded by at least 4-fold the glycogen accumulation rate (0.28 +/- 0.04 mumol of glucose/g/min). The total rate of glucose 6-phosphate supply via Glc phosphorylation and gluconeogenesis (2.9 mumol/g/min) exceeded reported in vivo rates of glycogen accumulation during refeeding. Thus, in perfused livers of 24-h fasted rats there is an apparent redundancy in glucose 6-phosphate supply. These results suggest that the rate-limiting step for hepatic glycogen accumulation during refeeding is located between glucose 6-phosphate and glycogen, rather than at the step of Glc phosphorylation or in the gluconeogenic pathway

MRI-based assessment of liver perfusion and hepatocyte injury in the murine model of acute hepatitis.

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Byk, Katarzyna; Jasinski, Krzysztof; Bartel, Zaneta; Jasztal, Agnieszka; Sitek, Barbara; Tomanek, Boguslaw; Chlopicki, Stefan; Skorka, Tomasz

2016-12-01

To assess alterations in perfusion and liver function in the concanavalin A (ConA)-induced mouse model of acute liver failure (ALF) using two magnetic resonance imaging (MRI)-based methods: dynamic contrast-enhanced MRI (DCE-MRI) with Gd-EOB-DTPA contrast agent and arterial spin labelling (ASL). BALB/c mice were studied using a 9.4 T MRI system. The IntraGateFLASH TM and FAIR-EPI pulse sequences were used for optimum mouse abdomen imaging. The average perfusion values for the liver of the control and ConA group were equal to 245 ± 20 and 200 ± 32 ml/min/100 g (p = 0.008, respectively). DCE-MRI showed that the time to the peak of the image enhancement was 6.14 ± 1.07 min and 9.72 ± 1.69 min in the control and ConA group (p < 0.001, respectively), while the rate of the contrast wash-out in the control and ConA group was 0.037 ± 0.008 and 0.021 ± 0.008 min -1 (p = 0.004, respectively). These results were consistent with hepatocyte injury in the ConA-treated mice as confirmed by histopathological staining. Both the ASL and DCE-MRI techniques represent a reliable methodology to assess alterations in liver perfusion and hepatocyte integrity in murine hepatitis.

Toxicity and Kinetics of (3H)Microcystin-LR in Isolated Perfused Rat Livers

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1990-03-20

with a Waters 490 multiwavelength detector, as described by Robinson et al. (1989). A C-18 column (Adsorbosphere HS, 4.6 x 250 mm, 5 Am, Alltech ...1988). The isolated perfused liver has several advantages over other model systems for the study of hepatotoxins. Unlike the in-vitro cell systems

Computed Tomography Perfusion Imaging for the Diagnosis of Hepatic Alveolar Echinococcosis

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Sade, Recep; Kantarci, Mecit; Genc, Berhan; Ogul, Hayri; Gundogdu, Betul; Yilmaz, Omer

2018-01-01

Objective: Alveolar echinococcosis (AE) is a rare life-threatening parasitic infection. Computed tomography perfusion (CTP) imaging has the potential to provide both quantitative and qualitative information about the tissue perfusion characteristics. The purpose of this study was the examination of the characteristic features and feasibility of CTP in AE liver lesions. Material and Methods: CTP scanning was performed in 25 patients who had a total of 35 lesions identified as AE of the liver. Blood flow (BF), blood volume (BV), portal venous perfusion (PVP), arterial liver perfusion (ALP), and hepatic perfusion indexes (HPI) were computed for background liver parenchyma and each AE lesion. Results: Significant differences were detected between perfusion values of the AE lesions and background liver tissue. The BV, BF, ALP, and PVP values for all components of the AE liver lesions were significantly lower than the normal liver parenchyma (p<0.01). Conclusions: We suggest that perfusion imaging can be used in AE of the liver. Thus, the quantitative knowledge of perfusion parameters are obtained via CT perfusion imaging. PMID:29531482

13C and 31P NMR study of gluconeogenesis: utilization of 13C-labeled substrates by perfused liver from streptozotocin-diabetic and untreated rats

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Cohen, S.M.

1987-01-01

The metabolism of 13 C-labeled substrates was followed by 13 C and 31 P NMR in perfused liver from the streptozotocin-treated rat model of insulin-dependent diabetes. Comparison was made with perfused liver from untreated littermates, fasted either 24 or 12 h. The major routes of pyruvate metabolism were followed by a 13 C NMR approach that provided for the determination of the metabolic fate of several substances simultaneously. The rate of gluconeogenesis was 2-4-fold greater and β-hydroxybutyrate production was 50% greater in liver from the chronically diabetic rats as compared with the control groups. Large differences in the distribution of 13 C label in hepatic alanine were measured between diabetic and control groups. The biosyntheses of 13 C-labeled glutathione and N-carbamoylaspartate were monitored in time-resolved 13 C NMR spectra of perfused liver. Assignments for the resonances of glutathione and N-carbamoylaspartate were made with the aid of 13 C NMR studies of perchloric acid extracts of the freeze-clamped livers. 13 C NMR spectroscopy of the perfusates provided a convenient, rapid assay of the rate of oxidation of [2- 13 C]ethanol, the hepatic output of [2- 13 ]acetaldehyde, and the accumulation of [2- 13 C]acetate in the perfusate. By 31 P NMR spectroscopy, carbamoyl phosphate was measured in all diabetic livers and an unusual P,P'-diesterified pyrophosphate was observed in one-fourth of the diabetic livers examined. Neither of these phosphorylated metabolites was detected in control liver. Both 13 C and 31 P NMR were useful in defining changes in hepatic metabolism in experimental diabetes

Is liver perfusion CT reproducible? A study on intra- and interobserver agreement of normal hepatic haemodynamic parameters obtained with two different software packages.

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Bretas, Elisa Almeida Sathler; Torres, Ulysses S; Torres, Lucas Rios; Bekhor, Daniel; Saito Filho, Celso Fernando; Racy, Douglas Jorge; Faggioni, Lorenzo; D'Ippolito, Giuseppe

2017-10-01

To evaluate the agreement between the measurements of perfusion CT parameters in normal livers by using two different software packages. This retrospective study was based on 78 liver perfusion CT examinations acquired for detecting suspected liver metastasis. Patients with any morphological or functional hepatic abnormalities were excluded. The final analysis included 37 patients (59.7 ± 14.9 y). Two readers (1 and 2) independently measured perfusion parameters using different software packages from two major manufacturers (A and B). Arterial perfusion (AP) and portal perfusion (PP) were determined using the dual-input vascular one-compartmental model. Inter-reader agreement for each package and intrareader agreement between both packages were assessed with intraclass correlation coefficients (ICC) and Bland-Altman statistics. Inter-reader agreement was substantial for AP using software A (ICC = 0.82) and B (ICC = 0.85-0.86), fair for PP using software A (ICC = 0.44) and fair to moderate for PP using software B (ICC = 0.56-0.77). Intrareader agreement between software A and B ranged from slight to moderate (ICC = 0.32-0.62) for readers 1 and 2 considering the AP parameters, and from fair to moderate (ICC = 0.40-0.69) for readers 1 and 2 considering the PP parameters. At best there was only moderate agreement between both software packages, resulting in some uncertainty and suboptimal reproducibility. Advances in knowledge: Software-dependent factors may contribute to variance in perfusion measurements, demanding further technical improvements. AP measurements seem to be the most reproducible parameter to be adopted when evaluating liver perfusion CT.

[Dynamics of the amino acid composition of the medium during cultivation of isolated liver and kidney by the controlled perfusion method].

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Barashkov, V A; Gitel'zon, I I; Nefedov, V P; Trubachev, I N

1975-11-01

The dynamics of the medium amino acid composition was studied during a 6-hour perfusion of dog kidney and liver by a mixture of autogenic plasma and medium 199 (a ratio of 2 : 3). In comparison to the initial level the amount of histidine during 6-hour cultivation of the kidney was found to increase 2.2 times, that of glutamic acid--1.7 times, and of alanine and lysine--1.6 times. At the same time the amount of arginine, serine and asparagic acid became 3.3 times and of glutamine and threonine--2.5 times lower. With the liver perfusion the level of glutaminic acid became 2.9 times, of alanine--2.3 times, of cystine--2 times and of glycine--1.5 times higher. With the liver perfusion the level of arginine decreased so rapidly that none was found in the medium after a 2-hour perfusion. The described method of amino acid analysis during the cultivation of the organs could serve as means for elaborating and correcting the culture media.

Studies on blood supply of liver metastasis with DSA, CT and portal vein perfusion CT during superior mesenteric arterial portography

International Nuclear Information System (INIS)

Li Zhigang; Shi Gaofeng; Huang Jingxiang; Li Shunzong; Liang Guoqing; Wang Hongguang; Han Pengyin; Wang Qi; Gu Tieshu

2008-01-01

Objective: To probe the blood supply of liver metastasis by celiac artery, proper hepatic artery DSA, portal vein perfusion CT during superior mesenteric arterial portography (PCTAP). Methods: One hundred patients with liver metastases were examined prospectively by plain CT scan, multiphase enhanced CT scan, celiac arteriography and proper hepatic arteriography. Of them, 56 patients were examined by PCTAP. All primary lesions were confirmed by operation and (or) pathology examination. In order to investigate the blood supply of metastasis lesions, the software of Photoshop was used to obtain the time-attenuation curves (TDC) of tumor center, tumor edge, portal vein and normal liver parenchyma adjacent to the tumor to calculate liver perfusion for DSA image analysis, while a deconvolution model from CT perfusion software was designed for the dual blood supply. Results: DSA findings: TDC of proper hepatic arteriography showed: the mean peak concentration (K value) in tumor centers was (67 ± 12)%, and it was (76 ± 15)% for peritumor tissue, (51 ± 10)% in normal liver parenchyma. TDC of celiac arteriogaphy showed that the contrast concentration of tumor centers and tumor edge increased fast in early stage, then maintained a slight upward plateau, in the meanwhile, the contrast concentration of normal liver parenchyma kept increasing slowly. PCTAP findings: tumors exhibited no enhancement during 30 s continued scans. Conclusion: The blood supply of liver metastasis mainly comes from hepatic artery, but barely from portal vein. (authors)

Hepatic perfusion during hepatic artery infusion chemotherapy: Evaluation with perfusion CT and perfusion scintigraphy

International Nuclear Information System (INIS)

Miller, D.L.; Carrasquillo, J.A.; Lutz, R.J.; Chang, A.E.

1989-01-01

The standard method for the evaluation of hepatic perfusion during hepatic artery infusion (HAI) chemotherapy is planar hepatic artery perfusion scintigraphy (HAPS). Planar HAPS was performed with 2 mCi of [99mTc] macroaggregated albumin infused at 1 ml/min and compared with single photon emission CT (SPECT) HAPS and with a new study, CT performed during the slow injection of contrast material through the HAI catheter (HAI-CT). Thirteen patients underwent 16 HAI-CT studies, 14 planar HAPS studies, and 9 SPECT HAPS studies. In 13 of 14 studies (93%) HAI-CT and planar HAPS were in complete agreement as to the perfusion pattern of intrahepatic metastases and normal liver. In nine studies where all modalities were performed, the findings identified by HAI-CT and planar HAPS agreed in all cases, whereas the results of two SPECT scans disagreed with the other studies. With respect to perfusion of individual metastases, 14 of 14 HAI-CT studies, 12 of 13 planar HAPS studies, and 9 of 9 SPECT HAPS studies correctly demonstrated the perfusion status of individual lesions as indicated by the pattern of changes in tumor size determined on CT obtained before and after the perfusion studies. Hepatic artery infusion CT was superior for delineation of individual metastases, particularly small lesions, and for the evaluation of nonperfused portions of the liver. Planar HAPS detected extrahepatic perfusion in four patients, and this was not detected by HAI-CT. We conclude that HAI-CT and scintigraphy are complementary techniques. Hepatic artery infusion CT has advantages for the evaluation of intrahepatic perfusion, and planar HAPS is superior to HAI-CT for the detection of extrahepatic perfusion

Influence of dietary fat on metabolism of (14-14C)erucic acid in the perfused rat liver. Distribution of metabolites in lipid classes

International Nuclear Information System (INIS)

Holmer, G.; Ronneberg, R.

1986-01-01

Two groups of rats were fed diets containing 20% by weight of either partially hydrogenated marine oil supplemented with sunflower seed oil (PHMO) or palm oil (PO) for 8 wk. Using a liver perfusion system, the effect of dietary long chain monoenoic fatty acids on the uptake and metabolism of [14- 14 C]erucic acid was studied. The perfusion times were 15 and 60 min, respectively. The two groups showed equal ability for erucic acid uptake in the liver but differed in the channeling of the fatty acids into various metabolic pathways. A higher metabolic turnover of 22:1 in the PHMO livers relative to the PO livers was demonstrated by an increased recovery of total [ 14 C]labeling in the triglyceride (TG) and phospholipid (PL) fractions, already evident after 15 min of perfusion. The chain-shortening capacity was highest in the PHMO group, reflected by a higher [ 14 C]18:1 incorporation in both TG and PL, and increasing from 15 to 60 min of perfusion. The amount of [ 14 C]18:1 found in PL and TG after 60 min of perfusion of livers from rats fed PO corresponded to that shown for the PHMO group after 15 min. The PL demonstrated a discrimination against 22:1 compared to TG, and, when available, 18:1 was highly preferred for PL-synthesis. The total fatty acid distribution in the TG, as determined by gas liquid chromatography (GLC), reflected the composition of the dietary fats. In the total liver PL, 22:1 and 20:1 were present in negligible amounts, although the PHMO diet contained 12-13% of both 22:1 and 20:1. In the free fatty acid fraction (FFA), the major part of the radioactivity (approximately 80%) was [14- 14 C]erucic acid, and only small amounts of [ 14 C]18:1 (less than 2%) were present, even after 60 min of perfusion. The shortened-chain 18:1 was readily removed from the FFA pool and preferentially used for lipid esterification

Estimating liver perfusion from free-breathing continuously acquired dynamic gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced acquisition with compressed sensing reconstruction.

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Chandarana, Hersh; Block, Tobias Kai; Ream, Justin; Mikheev, Artem; Sigal, Samuel H; Otazo, Ricardo; Rusinek, Henry

2015-02-01

The purpose of this study was to estimate perfusion metrics in healthy and cirrhotic liver with pharmacokinetic modeling of high-temporal resolution reconstruction of continuously acquired free-breathing gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced acquisition in patients undergoing clinically indicated liver magnetic resonance imaging. In this Health Insurance Portability and Accountability Act-compliant prospective study, 9 cirrhotic and 10 noncirrhotic patients underwent clinical magnetic resonance imaging, which included continuously acquired radial stack-of-stars 3-dimensional gradient recalled echo sequence with golden-angle ordering scheme in free breathing during contrast injection. A total of 1904 radial spokes were acquired continuously in 318 to 340 seconds. High-temporal resolution data sets were formed by grouping 13 spokes per frame for temporal resolution of 2.2 to 2.4 seconds, which were reconstructed using the golden-angle radial sparse parallel technique that combines compressed sensing and parallel imaging. High-temporal resolution reconstructions were evaluated by a board-certified radiologist to generate gadolinium concentration-time curves in the aorta (arterial input function), portal vein (venous input function), and liver, which were fitted to dual-input dual-compartment model to estimate liver perfusion metrics that were compared between cirrhotic and noncirrhotic livers. The cirrhotic livers had significantly lower total plasma flow (70.1 ± 10.1 versus 103.1 ± 24.3 mL/min per 100 mL; P The mean transit time was higher in the cirrhotic livers (24.4 ± 4.7 versus 15.7 ± 3.4 seconds; P the hepatocellular uptake rate was lower (3.03 ± 2.1 versus 6.53 ± 2.4 100/min; P < 0.05). Liver perfusion metrics can be estimated from free-breathing dynamic acquisition performed for every clinical examination without additional contrast injection or time. This is a novel paradigm for dynamic liver imaging.

Cavitation enhances coagulated size during pulsed high-intensity focussed ultrasound ablation in an isolated liver perfusion system.

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Zhao, Lu-Yan; Liu, Shan; Chen, Zong-Gui; Zou, Jian-Zhong; Wu, Feng

2016-11-24

To investigate whether cavitation enhances the degree of coagulation during pulsed high-intensity focussed ultrasound (HIFU) in an isolated liver perfusion system. Isolated liver was treated by pulsed HIFU or continuous-wave HIFU with different portal vein flow rates. The cavitation emission during exposure was recorded, and real-time ultrasound images were used to observe changes in the grey scale. The coagulation size was measured and calculated. HIFU treatment led to complete coagulation necrosis and total cell destruction in the target regions. Compared to exposure at a duty cycle (DC) of 100%, the mean volumes of lesions induced by 6 s exposure at DCs of 50% and 10% were significantly larger (P cavitation activity for the pulsed-HIFU (P > .05). For continuous-wave HIFU exposure, there was a significant decrease in the necrosis volume and cavitation activity for exposure times of 1, 2, 3, 4, and 6 s with increasing portal perfusion rates. Perfusion flow rates negatively influence cavitation activity and coagulation volume. Ablation is significantly enhanced during pulsed HIFU exposure compared with continuous-wave HIFU.

Macro- and microelements in the rat liver, kidneys, and brain tissues; sex differences and effect of blood removal by perfusion in vivo.

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Orct, Tatjana; Jurasović, Jasna; Micek, Vedran; Karaica, Dean; Sabolić, Ivan

2017-03-01

Concentrations of macro- and microelements in animal organs indicate the animal health status and represent reference data for animal experiments. Their levels in blood and tissues could be different between sexes, and could be different with and without blood in tissues. To test these hypotheses, in adult female and male rats the concentrations of various elements were measured in whole blood, blood plasma, and tissues from blood-containing (nonperfused) and blood-free liver, kidneys, and brain (perfused in vivo with an elements-free buffer). In these samples, 6 macroelements (Na, Mg, P, S, K, Ca) and 14 microelements (Fe, Mn, Co, Cu, Zn, Se, I, As, Cd, Hg, Pb, Li, B, Sr) were determined by inductively coupled plasma mass spectrometry following nitric acid digestion. In blood and plasma, female- or male-dominant sex differences were observed for 6 and 5 elements, respectively. In nonperfused organs, sex differences were observed for 3 (liver, brain) or 9 (kidneys) elements, whereas in perfused organs, similar differences were detected for 9 elements in the liver, 5 in the kidneys, and none in the brain. In females, perfused organs had significantly lower concentrations of 4, 5, and 2, and higher concentrations of 10, 4, and 7 elements, respectively, in the liver, kidneys, and brain. In males, perfusion caused lower concentrations of 4, 7, and 2, and higher concentrations of 1, 1, and 7 elements, respectively, in the liver, kidneys, and brain. Therefore, the residual blood in organs can significantly influence tissue concentrations of various elements and their sex-dependency. Copyright © 2017 Elsevier GmbH. All rights reserved.

Perfusion CT of the Brain and Liver and of Lung Tumors: Use of Monte Carlo Simulation for Patient Dose Estimation for Examinations With a Cone-Beam 320-MDCT Scanner.

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Cros, Maria; Geleijns, Jacob; Joemai, Raoul M S; Salvadó, Marçal

2016-01-01

The purpose of this study was to estimate the patient dose from perfusion CT examinations of the brain, lung tumors, and the liver on a cone-beam 320-MDCT scanner using a Monte Carlo simulation and the recommendations of the International Commission on Radiological Protection (ICRP). A Monte Carlo simulation based on the Electron Gamma Shower Version 4 package code was used to calculate organ doses and the effective dose in the reference computational phantoms for an adult man and adult woman as published by the ICRP. Three perfusion CT acquisition protocols--brain, lung tumor, and liver perfusion--were evaluated. Additionally, dose assessments were performed for the skin and for the eye lens. Conversion factors were obtained to estimate effective doses and organ doses from the volume CT dose index and dose-length product. The sex-averaged effective doses were approximately 4 mSv for perfusion CT of the brain and were between 23 and 26 mSv for the perfusion CT body protocols. The eye lens dose from the brain perfusion CT examination was approximately 153 mGy. The sex-averaged peak entrance skin dose (ESD) was 255 mGy for the brain perfusion CT studies, 157 mGy for the lung tumor perfusion CT studies, and 172 mGy for the liver perfusion CT studies. The perfusion CT protocols for imaging the brain, lung tumors, and the liver performed on a 320-MDCT scanner yielded patient doses that are safely below the threshold doses for deterministic effects. The eye lens dose, peak ESD, and effective doses can be estimated for other clinical perfusion CT examinations from the conversion factors that were derived in this study.

Assessment of hemodynamics in a rat model of liver cirrhosis with precancerous lesions using multislice spiral CT perfusion imaging.

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Ma, Guolin; Bai, Rongjie; Jiang, Huijie; Hao, Xuejia; Ling, Zaisheng; Li, Kefeng

2013-01-01

To develop an optimal scanning protocol for multislice spiral CT perfusion (CTP) imaging to evaluate hemodynamic changes in liver cirrhosis with diethylnitrosamine- (DEN-) induced precancerous lesions. Male Wistar rats were randomly divided into the control group (n = 80) and the precancerous liver cirrhosis group (n = 40). The control group received saline injection and the liver cirrhosis group received 50 mg/kg DEN i.p. twice a week for 12 weeks. All animals underwent plain CT scanning, CTP, and contrast-enhanced CT scanning. Scanning parameters were optimized by adjusting the diatrizoate concentration, the flow rate, and the delivery time. The hemodynamics of both groups was further compared using optimized multislice spiral CTP imaging. High-quality CTP images were obtained with following parameters: 150 kV; 150 mAs; 5 mm thickness, 5 mm interval; pitch, 1; matrix, 512 × 512; and FOV, 9.6 cm. Compared to the control group, the liver cirrhosis group had a significantly increased value of the hepatic arterial fraction and the hepatic artery perfusion (P spiral CTP imaging can be used to evaluate the hemodynamic changes in the rat model of liver cirrhosis with precancerous lesions.

Actions of p-synephrine on hepatic enzyme activities linked to carbohydrate metabolism and ATP levels in vivo and in the perfused rat liver.

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Maldonado, Marcos Rodrigues; Bracht, Lívia; de Sá-Nakanishi, Anacharis Babeto; Corrêa, Rúbia Carvalho Gomes; Comar, Jurandir Fernando; Peralta, Rosane Marina; Bracht, Adelar

2018-01-01

p-Synephrine is one of the main active components of the fruit of Citrus aurantium (bitter orange). Extracts of the bitter orange and other preparations containing p-synephrine have been used worldwide to promote weight loss and for sports performance. The purpose of the study was to measure the action of p-synephrine on hepatic enzyme activities linked to carbohydrate and energy metabolism and the levels of adenine mononucleotides. Enzymes and adenine mononucleotides were measured in the isolated perfused rat liver and in vivo after oral administration of the drug (50 and 300 mg/kg) by using standard techniques. p-Synephrine increased the activity of glycogen phosphorylase in vivo and in the perfused liver. It decreased, however, the activities of pyruvate kinase and pyruvate dehydrogenase also in vivo and in the perfused liver. p-Synephrine increased the hepatic pools of adenosine diphosphate and adenosine triphosphate. Stimulation of glycogen phosphorylase is consistent with the reported increased glycogenolysis in the perfused liver and increased glycemia in rats. The decrease in the pyruvate dehydrogenase activity indicates that p-synephrine is potentially capable of inhibiting the transformation of carbohydrates into lipids. The capability of increasing the adenosine triphosphate-adenosine diphosphate pool indicates a beneficial effect of p-synephrine on the cellular energetics. Copyright © 2017 John Wiley & Sons, Ltd.

Isolated hepatic perfusion as a treatment for uveal melanoma liver metastases (the SCANDIUM trial)

DEFF Research Database (Denmark)

Olofsson, Roger; Ny, Lars; Eilard, Malin Sternby

2014-01-01

for patients with liver metastases is between 6 and 12 months, and no treatment has in randomized trials ever been shown to prolong survival. A previous phase II trial using isolated hepatic perfusion (IHP) has suggested a 14-month increase in overall survival compared with a historic control group consisting...... of the longest surviving patients in Sweden during the same time period (26 versus 12 months). METHODS/DESIGN: This is the protocol for a multicenter phase III trial randomizing patients with isolated liver metastases of uveal melanoma to IHP or best alternative care (BAC). Inclusion criteria include liver....... The planned sample size is 78 patients throughout five years. DISCUSSION: Patients with isolated liver metastases of uveal melanoma origin have a short expected survival and no standard treatment option exists. This is the first randomized clinical trial to evaluate IHP as a treatment option with overall...

Visceral Perfusion Scintigraphy with {sup 131}I-Labelled Albumin Macroaggregates

Energy Technology Data Exchange (ETDEWEB)

Ueda, H.; Yamada, H.; Kitani, K.; Nagatani, M.; Takeda, T.; Migita, T.; Iio, M; Kameda, H. [University of Tokyo, Tokyo (Japan)

1969-05-15

The blood supply through the hepatic artery, superior mesenteric artery and portal vein to the visceral organs was studied in 60 cases of various hepatic disorders by scintigraphy after the selective introduction of {sup 131}I MAA by means of visceral arterial catheterization or percutaneous splenic puncture. A comparison of the radioactivities of the liver and the spleen after celiac arterial infusion (celiac perfusion scanning) indicated how much blood in the celiac artery was distributed to the two major arterial branches - the hepatic and splenic. Dominant perfusion was found through the hepatic branch in liver cirrhosis, whereas significantly dominant splenic blood perfusion was found in idiopathic non-cirrhotic portal hypertension. This remarkable contrast of the mode of celiac perfusion in two disorders indicated the etiological difference of these diseases. In malignant neoplasm of the liver, the dominant or exclusive celiac arterial perfusion was found in the tumour region. In these cases, liver scanning by the splenic injection of MAA (portal perfusion scanning) delineated the tumour region as a negative defect similar to the conventional {sup 198}Au colloid scanning. Consequently, from these two perfusion scintigrams the 'key and key-hole' pattern was demonstrated. It was concluded that a neoplastic lesion, primary or metastatic, has the predominant blood supply through the hepatic artery rather than through the portal vein. Celiac perfusion scanning of liver cystosis revealed multiple negative defects. This information was useful for differentiating a malignant tumour, which is usually impossible by conventional liver scanning. Celiac perfusion scanning was also useful for the diagnosis of arterial venous communication. In one case of liver .cancer with cirrhosis and another case with stomach varices, the arterial-v.enous communication was indicated by the appearance of the lung contour in the celiac perfusion scan. In both cases, the combined presence

Percutaneous Hepatic Perfusion (PHP) with Melphalan as a Treatment for Unresectable Metastases Confined to the Liver.

Science.gov (United States)

de Leede, Eleonora M; Burgmans, Mark C; Martini, Christian H; Tijl, Fred G J; van Erkel, Arian R; Vuyk, Jaap; Kapiteijn, Ellen; Verhoef, Cornelis; van de Velde, Cornelis J H; Vahrmeijer, Alexander L

2016-07-31

Unresectable liver metastases of colorectal cancer can be treated with systemic chemotherapy, aiming to limit the disease, extend survival or turn unresectable metastases into resectable ones. Some patients however, suffer from side effects or progression under systemic treatment. For patients with metastasized uveal melanoma there are no standard systemic therapy options. For patients without extrahepatic disease, isolated liver perfusion (IHP) may enable local disease control with limited systemic side effects. Previously, this was performed during open surgery with satisfying results, but morbidity and mortality related to the open procedure, prohibited a widespread application. Therefore, percutaneous hepatic perfusion (PHP) with simultaneous chemofiltration was developed. Besides decreasing morbidity and mortality, this procedure can be repeated, hopefully leading to a higher response rate and improved survival (by local control of disease). During PHP, catheters are placed in the proper hepatic artery, to infuse the chemotherapeutic agent, and in the inferior caval vein to aspirate the chemosaturated blood returning through the hepatic veins. The caval vein catheter is a double balloon catheter that prohibits leakage into the systemic circulation. The blood returning from the hepatic veins is aspirated through the catheter fenestrations and then perfused through an extra-corporeal filtration system. After filtration, the blood is returned to the patient by a third catheter in the right internal jugular vein. During PHP a high dose of melphalan is infused into the liver, which is toxic and would lead to life threatening complications when administered systemically. Because of the significant hemodynamic instability resulting from the combination of caval vein occlusion and chemofiltration, hemodynamic monitoring and hemodynamic support is of paramount importance during this complex procedure.

Radiofrequency Ablation with a New Perfused-Cooled Electrode Using a Single Pump: An Experimental Study in Ex Vivo Bovine Liver

International Nuclear Information System (INIS)

Kim, Seung Kwon; Seo, Jung Wook

2005-01-01

The purpose of this study was to assess the efficacy of a new perfused-cooled electrode that uses a single pump for creating a large ablation zone in explanted bovine liver. This was done by comparing with the radiofrequency (RF) ablation zones that were created with a monopolar cooled electrode to the RF ablation zones that were created by the new perfused-cooled electrode. We developed a new perfused-cooled electrode that uses a single pump by modifying a 17-gauge cooled electrode (Radionics) with a 2.5-cm outer metallic sheath (15-gauge) in order to allow use of the internal cooling water (5.85 % hypertonic saline) for the infused saline. Thirty ablation zones were created in explanted bovine livers (12-min ablation cycle; pulsed technique; 2000 mA, maximum) with three different regimens: group A, RF ablation with the 17-gauge cooled electrode; group B, RF ablation with the 15-gauge cooled electrode; group C, RF ablation with the perfused-cooled electrode. T2-weighted magnetic resonance (MR) imaging was obtained immediately after RF ablation for calculating volumes of the ablation zone. Following MR imaging, the ablation zones were excised and measured for transverse diameters and vertical diameters. The transverse diameter, vertical diameter, and the calculated volumes of the ablation zones on MR imaging were compared among the groups. Ablation zones created with the perfused-cooled electrode (group C) were significantly larger than those created with the 17-gauge cooled electrode (group A) and the 15-gauge cooled electrode (group B) according to the transverse diameter and vertical diameter on the gross specimens (p 3 in group A, 28.9 ± 5.7 cm 3 in group B, and 80.0 ± 34 cm 3 in group C, respectively. A new perfused-cooled electrode using a single pump could efficiently increase the size of the ablation zone in liver compared with a monopolar cooled electrode, and this was due to its simultaneous use of internal cooling and saline infusion

Uptake and degradation of cytoplasmic RNA by lysosomes in the perfused rat liver

International Nuclear Information System (INIS)

Heydrick, S.J.; Lardeux, B.; Mortimore, G.E.

1987-01-01

The release of [ 14 C]cytidine has been shown previously to be a valid marker for RNA degradation in rat hepatocytes. The breakdown of RNA measured with this marker in perfused livers prelabeled in vivo with [6- 14 C]orotic acid was found to be regulated acutely by perfusate amino acids over a wide range, from 0.29 to 3.48%/h. This regulation paralleled that of lysosomal proteolysis. Chloroquine inhibited RNA degradation 60-70%. In subsequent cell fractionation studies labelled cytidine was released; the distribution of this release paralleled that of a lysosomal marker enzyme. The release plateaued after two hours, defining a distinct lysosomal pool of RNA. The lysosomal location of the RNA pool was confirmed in experiments where a 22% increase in the apparent pool size was obtained by lowering the homogenate pH from 7.0 to 5.5. The pool size correlated linearly with the rate of RNA degradation measured during perfusion, giving a turnover constant in reasonable agreement with values reported for autophagy. These results indicate that cytoplasmic RNA degradation occurs primarily in the lysosome and is regulated under these conditions by the amino acid control of lysosomal sequestration of cytoplasm

Comparative study of rabbit VX2 hepatic implantation tumor and normal liver tissue on magnetic resonance perfusion weighted imaging

International Nuclear Information System (INIS)

Jiao Zimei; Wang Xizhen; Wang Bin; Liu Feng; Li Haiqing; Sun Yequan; Dong Peng

2012-01-01

Objective: To investigate the value of magnetic resonance (MR) perfusion weighted imaging (PWI) in evaluating the blood perfusion of tumor by analyzing the features and indexes of PWI on rabbit VX2 hepatic implantation tumor and normal liver tissue. Methods: Twenty-four New Zealand White rabbits with VX2 carcinoma were established under direct surgical vision embedding tumor tissue. MR examination was performed at 21 days after the tumor implantation. The signal intensity -time curve of hepatic tumor and normal liver tissue were obtained. Mean time to enhance (MTE), negative enhancement integral (NEI), time to minimum (TM), maximum slope of decrease (MSD) and maximum slope of increase (MSI) were measured. Results: MTE, NEI, TM, MSD, and MSI of the normal liver tissue were 208.341±2.226 ms, 78.334±8.152, 24.059±1.927 ms, 38.221±2.443, and 15.389±2.526, respectively. MTE, NEI, TM, MSD, and MSI of the tumor tissue were 175.437±4.182 ms, 123.203±19.455, 17.061±1.834 ms, 125.740±4.842, and 67.832±2.882, respectively. The MTE and TM of tumor were shorter than those of normal hepatic tissue (P<0.05). NEI, MSD, and MSI of tumor were higher than those of normal hepatic tissue (P<0.05). Conclusion: PWI can distinguish the normal liver tissue from the tumor tissue, which is helpful in evaluating blood perfusion of different hepatic tissues. (authors)

Management of isolated nonresectable liver metastases in colorectal cancer patients: a case-control study of isolated hepatic perfusion with melphalan versus systemic chemotherapy

NARCIS (Netherlands)

van Iersel, L. B. J.; Koopman, M.; van de Velde, C. J. H.; Mol, L.; van Persijn van Meerten, E. L.; Hartgrink, H. H.; Kuppen, P. J. K.; Vahrmeijer, A. L.; Nortier, J. W. R.; Tollenaar, R. A. E. M.; Punt, C.; Gelderblom, H.

2010-01-01

To compare the median overall survival of patients with isolated nonresectable liver metastases in comparable groups of patients treated with either isolated hepatic perfusion (IHP) with melphalan or systemic chemotherapy. Colorectal cancer patients with isolated liver metastases, who underwent IHP,

Hypoglycemic depression of hepatic phagocytosis in vivo and in the in situ perfused rat liver.

Science.gov (United States)

Kober, P M; Filkins, J P

1981-01-01

Depression of the phagocytic function of the reticuloendothelial system (RES) during endotoxic hypoglycemia has been implicated in the pathogenesis of endotoxin shock. The present study evaluated the in vivo effects of hypoglycemia on RES function and assessed the effects of an vivo bout of hypoglycemia on phagocytosis in the in situ perfused rat liver. Hypoglycemia was produced in male Holtzman rats using either 1 U of regular insulin (RI) (ILETIN, Lilly) or 0.75 U of long-acting insulin (LAI) (85% LENTE/15% ULTRALENTE, Lilly). RES function was quantitated by intravascular clearance of 8 mg/100 gm body weight colloidal carbon (CC). Two hr after RI and 2.5 hr after LAI, the intravascular halftimes of CC clearance were 19 +/- 2 min (N = 22) and 18 +/- 1 min (N = 19), respectively, as compared to control, 11.3 +/- 0.4 min (N = 53, P less than 0.001). The corresponding plasma glucose (PG) levels were 95 +/- 2 mg/dl in control, 14.4 +/- 0.9 for the RI group, and 17 +/- 1 for LAI. Two hr after RI, livers were perfused for 10 min in situ with 50 mg/liter CC in saline 5% rat serum. PG for control liver donors were 90 +/- 3 mg/dl, while those for hypoglycemic liver donors were 15 +/- 2. CC uptake was decreased from 22 micrograms/min/gm liver in the control (+ serum, n = 19) to 11 +/- 2 in hypoglycemia livers (N = 6); no effect of serum on hypoglycemic depression of the RES was seen. There were no differences in flow rates in the 2 groups. These results indicate that hypoglycemia directly impairs RES function and that the in vivo depression of intravascular clearance is not related to either the presence or absence of serum factors or total hepatic blood flow. Thus, the characteristic hypoglycemia of endotoxin shock may contribute to RES depression and the lethal shock syndrome.

Perfusion maps of the whole liver based on high temporal and spatial resolution contrast-enhanced MRI (4D THRIVE): Feasibility and initial results in focal liver lesions

International Nuclear Information System (INIS)

Coenegrachts, Kenneth; Ghekiere, Johan; Denolin, Vincent; Gabriele, Beck; Herigault, Gwen; Haspeslagh, Marc; Daled, Peter; Bipat, Shandra; Stoker, Jaap; Rigauts, Hans

2010-01-01

Purpose: To prospectively evaluate a new imaging sequence (4D THRIVE) for whole liver perfusion in high temporal and spatial resolution. Feasibility of parametric mapping and its potential for characterizing focal liver lesions (FLLs) are investigated. Materials and methods: Fifteen patients suspected for colorectal liver metastases (LMs) were included. Parametric maps were evaluated qualitatively (ring-enhancement and lesion heterogeneity) and compared to three-phased contrast-enhanced MRI. Quantitative analysis was based on average perfusion values of entire FLLs. Reference standard comprised surgery with histopathology or follow-up imaging. Fisher's exact test was used for qualitative and Kruskal-Wallis test for quantitative analysis. Results: In total 29 LMs, 17 hemangiomas and 4 focal nodular hyperplasias were evaluated. FLLs could be differentiated by qualitative assessment of parametric maps respectively three-phased contrast-enhanced MRI (Fisher's p < 0.001 for comparisons between LMs and hemangiomas and LMs and FNHs for both ring-enhancement and lesion heterogeneity) rather than by quantitative analysis of parametric maps (Chi-square for Kep = 0.33 (p = 0.847) and Chi-square for Kel = 1.35 (p = 0.509)). Conclusion: This preliminary study shows potential of 4D THRIVE for whole liver imaging enabling calculation of parametric maps. Qualitative rather than quantitative analysis was accurate for differentiating malignant and benign FLLs.

Intracellular mechanism of action of sympathetic hepatic nerves on glucose and lactate balance in perfused rat liver

NARCIS (Netherlands)

Ballé, C.; Beuers, U.; ENGELHARDT, R.; JUNGERMANN, K.

1987-01-01

In rat liver perfused in situ stimulation of the nerve plexus around the hepatic artery and the portal vein caused an increase in glucose output and a shift from lactate uptake to output. The effects of nerve stimulation on some key enzymes, metabolites and effectors of carbohydrate metabolism were

Liver perfusion CT during hepatic arteriography for the hepatocellular carcinoma: Dose reduction and quantitative evaluation for normal- and ultralow-dose protocol

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Shingo [Department of Radiology, Dokkyo Medical University Koshigaya Hospital, 2-1-50, Minami-Koshigaya, Koshigaya-shi, Saitama 343-8555 (Japan); Katada, Yoshiaki, E-mail: yoshiaki@dokkyomed.ac.jp [Department of Radiology, Dokkyo Medical University Koshigaya Hospital, 2-1-50, Minami-Koshigaya, Koshigaya-shi, Saitama 343-8555 (Japan); Gohkyu, Masaki; Nakajima, Masahiro; Kawabata, Hideyuki; Nozaki, Miwako [Department of Radiology, Dokkyo Medical University Koshigaya Hospital, 2-1-50, Minami-Koshigaya, Koshigaya-shi, Saitama 343-8555 (Japan)

2012-12-15

Objectives: The purpose of this study was to investigate whether substantial reduction of the computed tomography (CT) dose is possible in liver CT perfusion imaging by comparing the results of ultralow-dose CT perfusion imaging with those of conventional CT perfusion imaging the same patients and under the same conditions. Materials and methods: The study was composed following two parts: computer simulation and patients study. In computer simulation, noise was added to the images so that the standard deviation (SD) of the CT values in the liver parenchyma became various values using ImageJ. Time density curves (TDCs) were created from the simulated data, and the influence of difference in the SDs on the shapes of the TDCs was investigated. In the patient study, CT perfusion during intra-arterial injection was performed in 30 consecutive patients undergoing transcatheter arterial chemoembolization. CT perfusion images were acquired twice, at 100 mA (CTDI{sub vol}, 300 mGy) for normal and at 20 mA (CTDI{sub vol}, 60 mGy) for the ultralow radiation doses, under the same conditions. Results: No change was observed in the shape of the TDCs and peak values in the analysis of simulation images. A very good correlation was observed between the normal- and ultralow-dose CT images for all analyzed values (R{sup 2} = 0.9885 for blood flow, 0.9269 for blood volume, and 0.8424 for mean transit time). Conclusions: Our results demonstrated that there was no significant difference in the analysis results of perfusion CT between ultralow-dose CT performed using 20% of the conventional dose and normal-dose CT perfusion.

Tissue ablation accelerated by peripheral scanning mode with high-intensity focused ultrasound: a study on isolated porcine liver perfusion.

Science.gov (United States)

Bu, Rui; Yin, Li; Yang, Han; Wang, Qi; Wu, Feng; Zou, Jian Zhong

2013-08-01

The aims of this study were to investigate the feasibility of accelerated tissue ablation using a peripheral scanning mode with high-intensity focused ultrasound (HIFU) and to explore the effect of flow rate on total energy consumption of the target tissues. Using a model of isolated porcine liver perfusion via the portal vein and hepatic artery, we conducted a scanning protocol along the periphery of the target tissues using linear-scanned HIFU to carefully adjust the varying focal depth, generator power, scanning velocity and line-by-line interval over the entire ablation range. Porcine livers were divided into four ablation groups: group 1, n = 12, with dual-vessel perfusion; group 2, n = 11, with portal vein perfusion alone; group 3, n = 10, with hepatic artery perfusion alone; and group 4, n = 11, control group with no-flow perfusion. The samples were cut open consecutively at a thickness of 3 mm, and the actual ablation ranges were calculated along the periphery of the target tissues after triphenyl tetrazolium chloride staining. Total energy consumption was calculated as the sum of the energy requirements at various focal depths in each group. On the basis of the pre-supposed scanning protocol, the peripheral region of the target tissue formed a complete coagulation necrosis barrier in each group with varying dose combinations, and the volume of the peripheral necrotic area did not differ significantly among the four groups (p > 0.05). Furthermore, total energy consumption in each group significantly decreased with the corresponding decrease in flow rate (p Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Correlation between serum VEGF level and CT perfusion imaging in patients with primary liver cancer pre-and post TACE

International Nuclear Information System (INIS)

Jia Zhongzhi; Huang Yuanquan; Feng Yaoliang; Shi Haibin

2010-01-01

Objective: To investigate the correlation between serum vascular endothelial growth factor(VEGF) level and CT perfusion parameters in patients with primary liver cancer (PLC) pre-and post-transcatheter arterial chemoembolization (TACE) treatment. Methods: Serum VEGF level was measured and CT perfusion imaging was performed 1 day before and 6 ∼ 8, 32 ∼ 40 days after TACE in 18 patients with PLC. Before and after TACE, the serum VEGF level, the tumor's artery liver perfusion (ALP), the portal vein perfusion (PVP) and the hepatic artery perfusion index (HPI) were measured pre-and post-TACE. The pre-TACE and post-TACE results were compared and statistically analyzed. Results: Based on the therapeutic results, the patients were divided into complete response (CR) group and partial response or stable disease(PR+SD) group. Although no significant difference in serum VEGF level, tumor's ALP, PVP and HPI existed between two groups pre-TACE, there was significant difference in ALP, HPI 6-8 days after TACE (P<0.05). Significant difference in serum VEGF level also existed in CR group (P<0.05), but not in (PR+SD) group, at (32-40) days post-TACE (P=0.221). The serum VEGF level carried a positive correlation with the tumor's ALP and HPI. Conclusion: The serum VEGF level can indirectly reflect the neovascularization of the tumor, while the CTPI can directly and quantitatively reflect the hemodynamic changes of the tumor post-TACE. Moreover, a positive correlation exists between serum VEGF level and ALP, HPI. Therefore, the determination of serum VEGF level together with CTPI is very useful in both evaluating TACE efficacy and making therapeutic schedule. (authors)

Metabolite kinetics: formation of acetaminophen from deuterated and nondeuterated phenacetin and acetanilide on acetaminophen sulfation kinetics in the perfused rat liver preparation

International Nuclear Information System (INIS)

Pang, K.S.; Waller, L.; Horning, M.G.; Chan, K.K.

1982-01-01

The role of hepatic intrinsic clearance for metabolite formation from various precursors on subsequent metabolite elimination was was investigated in the once-through perfused rat liver preparation. Two pairs of acetaminophen precursors: [ 14 C] phenacetin-d5 and [ 3 H] phenacetin-do, [ 14 C] acetanilide and [ 3 H] phenacetin were delivered by constant flow (10 ml/min/liver) either by normal or retrograde perfusion to the rat liver preparations. The extents of acetaminophen sulfation were compared within the same preparation. The data showed that the higher the hepatocellular activity (intrinsic clearance) for acetaminophen formation, the greater the extent of subsequent acetaminophen sulfation. The findings were explained on the basis of blood transit time and metabolite duration time. Because of blood having only a finite transit time in liver, the longer the drug requires for metabolite formation, the less time will remain for metabolite sulfation and the less will be the degree of subsequent sulfation. Conversely, when the drug forms the primary metabolite rapidly, a longer time will remain for the metabolite to be sulfated in liver to result in a greater degree of metabolite sulfation. Finally, the effects of hepatic intrinsic clearances for metabolite formation and zonal distribution of enzyme systems for metabolite formation and elimination in liver are discussed

The value of multi-slice spiral CT liver perfusion imaging to evaluate the chronic hepatic fibrosis and cirrhosis

International Nuclear Information System (INIS)

Long Liling; Huang Zhongkui; Ding Ke; Liao Jinyuan; Jiang Jianning

2012-01-01

Objective: To investigate the value of the MSCT liver perfusion imaging parameters in the evaluation of the chronic hepatic fibrosis and cirrhosis. Methods: Liver CT perfusion (CTP) was performed in 107 participants,including 31 patients with mild hepatic fibrosis (S1, S2), 34 patients with severe hepatic fibrosis (S3, S4) and early stage of hepatic cirrhosis which conformed by liver pathologic biopsy, 42 patients with hepatic cirrhosis who had typical clinical and image signs, and 30 healthy subjects as control group. The data of CTP (HAP, PVP, LTP, HPI and TTP) at different stages were obtained with Body perfect CT-syngo CT2007A and control study with histopathologic stage. Compared the study index by the one-way ANOVA analysis. Used Spearman rank correlation to analysis the relationship between liver perfusion imaging parameters and the degrees of the chronic hepatic fibrosis. Used Logistic regression to analysis the maximum regression coefficient among the liver perfusion imaging parameters, which affected the histopathologic stage mostly. Results: In the subgroups of the chronic hepatic fibrosis S1, S2, S3, S4 to the hepatic cirrhosis,HAP values was (28.9 ±8.6), (24.6 ±2.4), (29.2 ±2.3) and (38.9 ± 7.0) ml · 100 ml -1 · min -1 , respectively. HAP decreased firstly,then increased. Statistic analysis showed the difference of HAP between later-stage cirrhosis and other groups (F=40.26, P<0.01). PVP values of above subgroups was (111.3 ± 18.1), (92.9 ±5.3), (73.0 ±9.0) and (54.1 ± 13.8) ml · 100 ml -1 ·min -1 , respectively. TLP values of above subgroups was (140.2 ± 25.9), (117.1 ± 4.5), (102.3 ± 8.7)and (93.0 ± 11.8) ml · 100 ml -1 ·min -1 , respectively. The difference of PVP, TLP among each subgroup was significant (F=136.79, 67.40, respectively, P<0.01). HPI values of above subgroups was (20.4 ± 2.6)%, (21.0 ±2.1)%, (28.5 ±3.1)% and (42.6± 11.1)%, respectively. TTP values of above subgroups was (123.7±22.2), (137.1 ±27.1), (145.0 ±28

Measurement of body temperature in normothermic and febrile rats: Limitations of using rectal thermometry.

Science.gov (United States)

Dangarembizi, Rachael; Erlwanger, Kennedy H; Mitchell, Duncan; Hetem, Robyn S; Madziva, Michael T; Harden, Lois M

2017-10-01

Stress-induced hyperthermia following rectal thermometry is reported in normothermic rats, but appears to be muted or even absent in febrile rats. We therefore investigated whether the use of rectal thermometry affects the accuracy of temperature responses recorded in normothermic and febrile rats. Using intra-abdominally implanted temperature-sensitive radiotelemeters we measured the temperature response to rectal temperature measurement in male Sprague Dawley rats (~200g) injected subcutaneously with Brewer's yeast (20ml/kg of a 20% Brewer's yeast solution=4000mg/kg) or saline (20ml/kg of 0.9% saline). Rats had been pre-exposed to, or were naive to rectal temperature measurement before the injection. The first rectal temperature measurement was taken in the plateau phase of the fever (18h after injection) and at hourly intervals thereafter. In normothermic rats, rectal temperature measurement was associated with an increase in abdominal temperature (0.66±0.27°C) that had a rapid onset (5-10min), peaked at 15-20min and lasted for 35-50min. The hyperthermic response to rectal temperature measurement was absent in febrile rats. Exposure to rectal temperature measurement on two previous occasions did not reduce the hyperthermia. There was a significant positive linear association between temperatures recorded using the two methods, but the agreement interval identified that rectal temperature measured with a thermocouple probe could either be 0.7°C greater or 0.5°C lower than abdominal temperature measured with radiotelemeter. Thus, due to stress-induced hyperthermia, rectal thermometry does not ensure accurate recording of body temperature in short-spaced, intermittent intervals in normothermic and febrile rats. Copyright © 2017 Elsevier Inc. All rights reserved.

Whole-liver MR perfusion imaging in rabbit liver VX2 tumors: early findings of coagulative necrosis after percutaneous ethanol injection therapy

International Nuclear Information System (INIS)

Zhang Wanshi; Wang Dong; Meng Limin; Shi Huiping; Song Yunlong; Wu Bing

2007-01-01

Objective: To investigate the value of whole-liver MR perfusion imaging (MRPI) for early detection of coagulative necrosis after percutaneous ethanol injection (PEI) in rabbit liver VX 2 tumors. Methods: VX 2 tumor cell suspension was inoculated into rabbit liver and liver VX 2 tumors [diameter of (2.6 ± 0.6) cm] were induced in 10 male rabbits. MR T 1 WI and T 2 WI were performed to monitor the development of the liver tumor on the 2 nd and 3 rd week after inoculation. Whole-liver MRPI was performed in the 10 rabbits with liver VX 2 tumors before and 6 days after PEI therapy (1.0 ml ethanol was injected into the most enhanced tumor region under CT guiding). Signal intensity (SI) values of untreated tumor parts and treated areas 6 days after PEI were recorded respectively. The steepest slope (SS) and bolus arrival time (T0) of SI-time curves were measured. The t-Student test was used in statistical analysis of the data. Results: There was significant difference in MRPI data between untreated tumor parts [T0: (16.0 ± 1.2) s and SS: 38.9 ± 2.2] and treated areas [T0: (50.8 ± 5.9) s and SS: 6.0 ± 1.2] 6 days after PEI(t was 15.8 and -39.6 respectively, P 1 WI and T 2 WI could not show any differences between untreated tumor parts and treated areas. Conclusion: Whole-liver MRPI could detect coagulative necrosis of rabbit liver VX 2 tumors after PEI early. Disappearance of early enhancement can be a potential marker for efficacy of PEI. (authors)

CT-based liver volumetry in a porcine model: impact on clinical volumetry prior to living donated liver transplantation

International Nuclear Information System (INIS)

Frericks, B.B.J.; Kiene, T.; Stamm, G.; Shin, H.; Galanski, M.

2004-01-01

Purpose: Exact preoperative determination of the liver volume is of great importance prior to hepatobiliary surgery, especially in living donated liver transplantation (LDLT). In the current literature, a strong correlation between preoperatively calculated and intraoperatively measured liver volumes has been described. Such accuracy seems questionable, primarily due to a difference in the perfusion state of the liver in situ versus after explantation. Purpose of the study was to asses the influence of the perfusion state on liver volume and the validity of the preoperative liver volumetry prior to LDLT. Methods: In an experimental study, 20 porcine livers were examined. The livers were weighted and their volumes were determined by water displacement prior and after fluid infusion to achieve a pressure physiologically found in the liver veins. The liver volumes in the different perfusion states were calculated based on CT-data. The calculated values were compared with the volume measured by water displacement and the weight of the livers. Results: Assessment of calculated CT volumes and water displacements at identical perfusion states showed a tight correlation and differed on average by 4 ± 5%. However, livers before and after fluid infusion showed a 33 ± 8% (350 ± 150 ml) difference in volume. Conclusion: CT-volumetry acquires highly accurate data as confirmed by water displacement studies. However, the perfusion state has major impact on liver volume, which has to be accounted for in clinical use. (orig.) [de

Hepatic Differentiation of Human Induced Pluripotent Stem Cells in a Perfused 3D Porous Polymer Scaffold for Liver Tissue Engineering

DEFF Research Database (Denmark)

Hemmingsen, Mette; Muhammad, Haseena Bashir; Mohanty, Soumyaranjan

A huge shortage of liver organs for transplantation has motivated the research field of tissue engineering to develop bioartificial liver tissue and even a whole liver. The goal of NanoBio4Trans is to create a vascularized bioartificial liver tissue, initially as a liver-support system. Due...... to limitations of primary hepatocytes regarding availability and maintenance of functionality, stem cells and especially human induced pluripotent stem cells (hIPS cells) are an attractive cell source for liver tissue engineering. The aim of this part of NanoBio4Trans is to optimize culture and hepatic...... differentiation of hIPS-derived definitive endoderm (DE) cells in a 3D porous polymer scaffold built-in a perfusable bioreactor. The use of a microfluidic bioreactor array enables the culture of 16 independent tissues in one experimental run and thereby an optimization study to be performed....

The spleen-liver uptake ratio in liver scan: review of its measurement and correlation between hemodynamical changes of the liver in portal hypertension

International Nuclear Information System (INIS)

Lee, S. Y.; Chung, Y. A.; Chung, H. S.; Lee, H. G.; Kim, S. H.; Chung, S. K.

1999-01-01

We analyzed correlation between changes of the Spleen-Liver Ratio in liver scintigram and hemodynamical changes of the liver in overall grades of portal hypertension by non-invasive, scintigraphic method. And the methods for measurement of the Spleen-Liver Ratio were also reviewed. Hepatic scintiangiograms for 120 seconds with 250-333 MBq of 99mTc-Sn-phytate followed by liver scintigrams were performed in 62 patients group consisted with clinically proven norma and various diffuse hepatocellular diseases. Hepatic Perfusion indices were calculated from the Time-Activity Curves of hepatic scintiangiograms. Each Spleen-Liver Ratios of maximum, average and total counts within ROIs of the liver and spleen from both anterior and posterior liver scintigrams and their geometrical means were calculated. Linear correlations between each Spleen-Liver Ratios and Hepatic Perfusion indices were evaluated. There was strong correlation (y=0.0002x 2 -0.0049x+0.2746, R=0.8790, p<0.0001) between Hepatic Perfusion Indices and Spleen-Liver Ratios calculated from posterior maxium counts of the liver scintigrams. Weaker correlations with either geometrical means of maximum and average count methods (R=0.8101, 0.7268, p<0.0001) or average counts of both posterior and anterior veiws (R=0.8134, 0.6200, p<0.0001) were noted. We reconfirmed that changes of Spleen-Liver Ratio in liver scintigrams represent hemodynamical changes in portal hypertension of diffuse hepatocellular diseases. Among them, the posterior Spleen-Liver Ratio measured by maximum counts will give the best information. And matching with Hepatic Perfusion index will be another useful index to evaluate characteristics splenic extraction coefficient of a certain radiocolloid for liver scintigram

Prevalence of myocardial perfusion abnormalities in end-stage liver disease

International Nuclear Information System (INIS)

Fathala, Ahmed; Safar, Bander; Al Muhaideb, Ahmed

2011-01-01

The prevalence of coronary artery disease (CAD) in end-stage liver disease (ESLD) being evaluated for orthotopic liver transplantation (OLT) is unclear based on variable definition used for CAD. The aim of this study to investigate the prevalence of abnormal stress myocardial perfusion single-photon emission computed tomography (MPS) imaging, as a marker for CAD, among patients with ESLD who were referred for stress MPS imaging as a routine work up before OLT. This was a single-center, retrospective study. We reviewed data on 167 patients who were referred for MPS as a routine work up before OLT over the last 2 years. All patients underwent evaluation for CAD risk factors [age, hypercholesterolemia, diabetes mellitus (DM), hypertension (HTN), and smoking], and stress MPS as per standard protocol. The total number of patients referred for stress MPS was 167. Seven patients (4% of total study population) were excluded from the study due to poor and/or nondiagnostic studies. 147 patients (92%) had normal, but only 13 patients (8%) had abnormal MPS scans. DM and male gender were the most independent risk factors for abnormal MPS with P value of 0.046, and 0.26, respectively. There was no significant association between the abnormal MPS result and HTN, hypercholesterolemia, smoking, age or etiology of the liver disease. Based on our data, the prevalence of abnormal MPS and left ventricular ejection fraction in patients with ESLD was found to be 8%. DM and male gender were the most independent predictor factors for abnormal MPS. True prevalence of CAD and usefulness of MPS in patients with ESLD can only be studied using a very large and randomized prospective study

Cytoplasmic binding and disposition kinetics of diclofenac in the isolated perfused rat liver

Science.gov (United States)

Weiss, Michael; Kuhlmann, Olaf; Hung, Daniel Y; Roberts, Michael S

2000-01-01

The binding kinetics of diclofenac to hepatocellular structures were evaluated in the perfused rat liver using the multiple indicator dilution technique and a stochastic model of organ transit time density.The single-pass, in situ rat liver preparation was perfused with buffer solution (containing 2% albumin) at 30 ml min−1. Diclofenac and [14C]-sucrose (extracellular reference) were injected simultaneously as a bolus dose into the portal vein (six experiments in three rats). An analogous series of experiments was performed with [14C]-diclofenac and [3H]-sucrose.The diclofenac outflow data were analysed using three models of intracellular distribution kinetics, assuming (1) instantaneous distribution and binding (well-mixed model), (2) ‘slow' binding at specific intracellular sites after instantaneous distribution throughout the cytosol (slow binding model), and (3) ‘slowing' of cytoplasmic diffusion due to instantaneous binding (slow diffusion model).The slow binding model provided the best description of the data. The rate constants for cellular influx and sequestration were 0.126±0.026 and 0.013±0.009 s−1, respectively. The estimated ratio of cellular initial distribution volume to extracellular volume of 2.82 indicates an almost instantaneous distribution in the cellular water space, while the corresponding ratio of 5.54 estimated for the apparent tissue distribution volume suggests a relatively high hepatocellular binding. The non-instantaneous intracellular equilibration process was characterized by time constants of the binding and unbinding process of 53.8 and 49.5 s, respectively. The single-pass availability of diclofenac was 86%. The results obtained with [14C]-diclofenac and [3H]-sucrose were not statistically different. PMID:10903973

A Low-Protein Diet Alters Rat Behavior and Neurotransmission in Normothermic and Hyperthermic Environments

National Research Council Canada - National Science Library

Lieberman, Harris R; Yeghiayan, Sylva K; Maher, Timothy J

2005-01-01

.... Therefore, the behavioral and neurochemical consequences of exposure to a brief (11 days), low-protein (4%) diet in animals exposed to normothermic and hyperthermic test conditions were examined...

Subnormothermic ex vivo liver perfusion reduces endothelial cell and bile duct injury after donation after cardiac death pig liver transplantation.

Science.gov (United States)

Knaak, Jan M; Spetzler, Vinzent N; Goldaracena, Nicolas; Boehnert, Markus U; Bazerbachi, Fateh; Louis, Kristine S; Adeyi, Oyedele A; Minkovich, Leonid; Yip, Paul M; Keshavjee, Shaf; Levy, Gary A; Grant, David R; Selzner, Nazia; Selzner, Markus

2014-11-01

An ischemic-type biliary stricture (ITBS) is a common feature after liver transplantation using donation after cardiac death (DCD) grafts. We compared sequential subnormothermic ex vivo liver perfusion (SNEVLP; 33°C) with cold storage (CS) for the prevention of ITBS in DCD liver grafts in pig liver transplantation (n = 5 for each group). Liver grafts were stored for 10 hours at 4°C (CS) or preserved with combined 7-hour CS and 3-hour SNEVLP. Parameters of hepatocyte [aspartate aminotransferase (AST), international normalized ratio (INR), factor V, and caspase 3 immunohistochemistry], endothelial cell (EC; CD31 immunohistochemistry and hyaluronic acid), and biliary injury and function [alkaline phosphatase (ALP), total bilirubin, and bile lactate dehydrogenase (LDH)] were determined. Long-term survival (7 days) after transplantation was similar between the SNEVLP and CS groups (60% versus 40%, P = 0.13). No difference was observed between SNEVLP- and CS-treated animals with respect to the peak of serum INR, factor V, or AST levels within 24 hours. CD31 staining 8 hours after transplantation demonstrated intact EC lining in SNEVLP-treated livers (7.3 × 10(-4) ± 2.6 × 10(-4) cells/μm(2)) but not in CS-treated livers (3.7 × 10(-4) ± 1.3 × 10(-4) cells/μm(2) , P = 0.03). Posttransplant SNEVLP animals had decreased serum ALP and serum bilirubin levels in comparison with CS animals. In addition, LDH in bile fluid was lower in SNEVLP pigs versus CS pigs (14 ± 10 versus 60 ± 18 μmol/L, P = 0.02). Bile duct histology revealed severe bile duct necrosis in 3 of 5 animals in the CS group but none in the SNEVLP group (P = 0.03). Sequential SNEVLP preservation of DCD grafts reduces bile duct and EC injury after liver transplantation. © 2014 American Association for the Study of Liver Diseases.

Radiofrequency ablation of liver tumors by using monopolar perfusion electrode:an analysis of therapeutic results

International Nuclear Information System (INIS)

Luo Rongguang; Gu Yangkui; Gao Fei; Zhang Liang; Zhao Ming; Fan Weijun; Wu Peihong; Huang Jinhua

2010-01-01

Objective: To investigate the clinical value of CT-guided radiofrequency ablation by using monopolar perfusion electrode in treating liver tumors. Methods: From January 2008 to December 2008, 24 patients with 37 lesions of liver tumors were treated with radiofrequency ablation by using monopolar perfusion electrode (RITA UniBlate). Of the 24 patients,solitary lesion was seen in 14, two lesions in 7 and three lesions in 3. Among 37 lesions,the maximum diameter of the lesion ≤ 3 cm, 3.1∼5 cm and > 5 cm was determined in 24, 8 and 5, respectively. The changes of the tumor size and the AFP level were observed. A follow-up lasting for 12 months was conducted. Results: After radiofrequency ablation twenty-two lesions (22/37, 59.5%) were completely ablated, of which nineteen tumors (19/24, 79.2%) were smaller than 3 cm in diameter, two tumors (2 / 8, 25%) had a diameter between 3.1 cm and 5 cm, one tumor (1 / 5, 20%) was larger than 5 cm. Fifteen tumors (15 / 37, 40.5%) were not completely ablated. During the follow-up period of 12 months, fifteen patients (15 / 24, 62.5%) remained alive and nine patients died, of whom the survival time was less than 6 months in six and was 6 -12 months in 4. After radiofrequency ablation, the AFP level decreased to normal level in 5 patients (5 / 10, 50%), and mild decrease of AFP, but still higher than normal,was seen in 3 patients (3 / 10, 30%). Of 10 patients who had a positive AFP test, 2 (2 / 10, 10%) showed a continuous rise in the AFP level. After radiofrequency ablation, one patient developed a minor hepatic subcapsular bleeding,and all patients complained of different degrees of fever and upper abdominal pain. Conclusion: CT-guided radiofrequency ablation by using monopolar perfusion electrode is a minimally-invasive technique with reliable short-term results and fewer complications. Therefore, it is a safe and effective local treatment for liver cancer. For tumors smaller than 3 cm in diameter complete ablation can be

Hypothermic oxygenated machine perfusion reduces bile duct reperfusion injury after transplantation of donation after circulatory death livers

Science.gov (United States)

van Rijn, Rianne; van Leeuwen, Otto B.; Matton, Alix P. M.; Burlage, Laura C.; Wiersema‐Buist, Janneke; van den Heuvel, Marius C.; de Kleine, Ruben H. J.; de Boer, Marieke T.; Gouw, Annette S. H.

2018-01-01

Dual hypothermic oxygenated machine perfusion (DHOPE) of the liver has been advocated as a method to reduce ischemia/reperfusion injury (IRI). This study aimed to determine whether DHOPE reduces IRI of the bile ducts in donation after circulatory death (DCD) liver transplantation. In a recently performed phase 1 trial, 10 DCD livers were preserved with DHOPE after static cold storage (SCS; http://www.trialregister.nl NTR4493). Bile duct biopsies were obtained at the end of SCS (before DHOPE; baseline) and after graft reperfusion in the recipient. Histological severity of biliary injury was graded according to an established semiquantitative grading system. Twenty liver transplantations using DCD livers not preserved with DHOPE served as controls. Baseline characteristics and the degree of bile duct injury at baseline (end of SCS) were similar between both groups. In controls, the degree of stroma necrosis (P = 0.002) and injury of the deep peribiliary glands (PBG; P = 0.02) increased after reperfusion compared with baseline. In contrast, in DHOPE‐preserved livers, the degree of bile duct injury did not increase after reperfusion. Moreover, there was less injury of deep PBG (P = 0.04) after reperfusion in the DHOPE group compared with controls. In conclusion, this study suggests that DHOPE reduces IRI of bile ducts after DCD liver transplantation. Liver Transplantation 24 655–664 2018 AASLD. PMID:29369470

Portal venous perfusion steal causing graft dysfunction after orthotopic liver transplantation: serial imaging findings in a successfully treated patient

Energy Technology Data Exchange (ETDEWEB)

Lee, Min Su; Chung, Yong Eun; Choi, Jin Young; Park, Mi Suk; Lim, Joon Seok; Kim, Myeong Jin; Kim, Hon Soul [Dept. of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Kim, Sang Kyun [Dept. of Pathology, Yonsei University College of Medicine, Seoul (Korea, Republic of)

2016-01-15

A 53-year-old male with hepatocellular carcinoma underwent orthotopic liver transplantation. Preoperative computed tomography revealed main portal vein luminal narrowing by flat thrombi and the development of cavernous transformation. On post-transplantation day 1, thrombotic portal venous occlusion occurred, and emergency thrombectomy was performed. Subsequent Doppler ultrasonography and contrast-enhanced ultrasonography confirmed the restoration of normal portal venous flow. The next day, however, decreased portal venous velocity was observed via Doppler ultrasonography, and serum liver enzymes and bilirubin levels remained persistently elevated. Direct portography identified massive perfusion steal through prominent splenorenal collateral veins. Stent insertion and balloon angioplasty of the portal vein were performed, and subsequent Doppler ultrasonography demonstrated normalized portal flow parameters. Afterwards, the serum liver enzymes and bilirubin levels rapidly normalized.

A Newly Developed Perfused Umbrella Electrode for Radiofrequency Ablation: An Ex Vivo Evaluation Study in Bovine Liver

International Nuclear Information System (INIS)

Bruners, Philipp; Pfeffer, Jochen; Kazim, Rana M.; Guenther, Rolf W.; Schmitz-Rode, Thomas; Mahnken, Andreas H.

2007-01-01

The purpose of this study was to evaluate the effectiveness of a newly developed perfused monopolar radiofrequency (RF) probe with an umbrella-shaped array. A perfused umbrella-shaped monopolar RF probe based on a LeVeen electrode (Boston Scientific Corp., Natick, MA, USA) with a 3-cm array diameter was developed. Five different configurations of this electrode were tested: (a) perfusion channel/endhole, (b) perfusion channel/endhole + sideholes, (c) 1 cm insulation removed at the tip, (d) 1 cm insulation removed at the tip + perfusion channel/endhole, and (e) 1 cm insulation removed at the tip + perfusion channel/endhole + sideholes. An unmodified LeVeen electrode served as a reference standard. RF ablations were performed in freshly excised bovine liver using a commercial monopolar RF system with a 200-W generator (RF 3000; Boston Scientific Corp.). Each electrode was tested 10 times applying the vendor's recommended ablation protocol combined with the preinjection of 2 ml 0.9% saline. Volumes and shapes of the lesions were compared. Lesions generated with the original LeVeen electrode showed a mean volume of 12.74 ± 0.52 cm 3 . Removing parts of the insulation led to larger coagulation volumes (22.65 ± 2.12 cm 3 ). Depending on the configuration, saline preinjection resulted in a further increase in coagulation volume (25.22 ± 3.37 to 31.28 ± 2.32 cm 3 ). Besides lesion volume, the shape of the ablation zone was influenced by the configuration of the electrode used. We conclude that saline preinjection in combination with increasing the active tip length of the umbrella-shaped LeVeen RF probe allows the reliable ablation of larger volumes in comparison to the originally configured electrode

Computed Tomography (CT) Perfusion in Abdominal Cancer

DEFF Research Database (Denmark)

Hansen, Martin Lundsgaard; Norling, Rikke; Lauridsen, Carsten

2013-01-01

Computed Tomography (CT) Perfusion is an evolving method to visualize perfusion in organs and tissue. With the introduction of multidetector CT scanners, it is now possible to cover up to 16 cm in one rotation, and thereby making it possible to scan entire organs such as the liver with a fixed...

Effects of lysosomal inhibitors on 125I-insulin and 125I-asialofetuin degradation by the isolated, perfused rat liver and isolated rat hepatocytes

International Nuclear Information System (INIS)

Ward, W.F.; Moss, A.L.

1985-01-01

To further evaluate the role of the lysosomal system in insulin degradation, the authors have compared the effects of inhibitors of lysosomal function on the degradation of 125 I-insulin with 125 I-asialofetuin, a lysosomally targeted molecule, by the intact, perfused rat liver and the isolated rat hepatocyte. The inhibitors employed were chloroquine ( 125 microM), NH 4 Cl (10 mM), and leupeptin (50 micrograms/ml). In the intact, perfused liver the observed inhibition of 125 I-asialofetuin degradation at 30 min was as follows: chloroquine, 38%; NH 4 Cl, 32%; and leupeptin, 86%. Chloroquine also inhibited 125 I-insulin degradation in the intact, perfused liver (29%), but NH 4 Cl and leupeptin had no effect. Using the isolated hepatocyte, the observed values for inhibition of 125I-asialofetuin at 60 min were: chloroquine, 85%; NH 4 Cl, 76%; and leupeptin, 81%. Chloroquine produced a 28% inhibition of 125I-insulin degradation, while NH 4 Cl and leupeptin had no effect. Chloroquine and NH 4 Cl decreased cell-associated radioactivity when isolated hepatocytes were incubated with 125I-asialofetuin (leupeptin had no effect), whereas chloroquine caused a 107% increase in cell-associated radioactivity when 125I-insulin was added to the incubation media (NH 4 Cl and leupeptin had no effect). These results indicate that the effects of chloroquine on insulin degradation are an extralysosomal action and that lysosomes appear not to be involved in the physiologic degradation of the insulin molecule

Use of radioactive glucosamine in the perfused rat liver to prepare α1-acid glycoprotein (orosomucoid) with 3H- or 14C-labelled sialic acid and N-acetylglucosamine residues

International Nuclear Information System (INIS)

Aronson, N.N. Jr.

1982-01-01

A method was developed whereby [1- 14 C]glucosamine was used in a perfused rat liver system to prepare over 2 mg of α 1 -acid glycoprotein with highly radioactive sialic acid and glucosamine residues. The liver secreted radioactive α 1 -acid glycoprotein over a 4-6 h period, and this glycoprotein was purified from the perfusate by chromatography on DEAE-cellulose at pH3.6. The sialic acid on the isolated glycoprotein had a specific radioactivity of 3.1 Ci/mol, whereas the glucosamine-specific radioactivity was 4.3 Ci/mole. The latter amino-sugar residues on the isolated protein were only 13-fold less radioactive than the initially added [1- 14 C]glucosamine. Orosomucoid with a specific radioactivity of 31.3 μCi/mg of protein was obtainable by using [6- 3 H]glucosamine. Many other radioactive glycoproteins were found to be secreted into the perfusate by the liver. Thus this experimental system should prove useful for obtaining other serum glycoproteins with highly radioactive sugar moieties. (author)

Implementing an innovated preservation technology: The American Society of Transplant Surgeons' (ASTS) Standards Committee White Paper on Ex Situ Liver Machine Perfusion.

Science.gov (United States)

Quintini, Cristiano; Martins, Paulo N; Shah, Shimul; Killackey, Mary; Reed, Alan; Guarrera, James; Axelrod, David A

2018-05-23

The pervasive shortage of deceased donor liver allografts contributes to significant waitlist mortality despite efforts to increase organ donation. Ex vivo liver perfusion appears to enhance preservation of donor organs, extending viability and potentially evaluating function in organs previously considered too high risk for transplant. These devices pose novel challenges for organ allocation, safety, training, and finances. This white paper describes the American Society of Transplant Surgeons' belief that organ preservation technology is a vital advance, but its use should not change fundamental aspects of organ allocation. Additional data elements need to be collected, made available for organ assessment by transplant professionals to allow determination of organ suitability in the case of reallocation and incorporated into risk adjustment methodology. Finally, further work is needed to determine the optimal strategy for management and oversight of perfused organs prior to transplantation. © 2018 The American Society of Transplantation and the American Society of Transplant Surgeons.

Renal versus splenic maximum slope based perfusion CT modelling in patients with portal-hypertension

Energy Technology Data Exchange (ETDEWEB)

Fischer, Michael A. [University Hospital Zurich, Department of Diagnostic and Interventional Radiology, Zurich (Switzerland); Karolinska Institutet, Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Stockholm (Sweden); Brehmer, Katharina [Karolinska University Hospital Huddinge, Department of Radiology, Stockholm (Sweden); Svensson, Anders; Aspelin, Peter; Brismar, Torkel B. [Karolinska Institutet, Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Stockholm (Sweden); Karolinska University Hospital Huddinge, Department of Radiology, Stockholm (Sweden)

2016-11-15

To assess liver perfusion-CT (P-CT) parameters derived from peak-splenic (PSE) versus peak-renal enhancement (PRE) maximum slope-based modelling in different levels of portal-venous hypertension (PVH). Twenty-four patients (16 men; mean age 68 ± 10 years) who underwent dynamic P-CT for detection of hepatocellular carcinoma (HCC) were retrospectively divided into three groups: (1) without PVH (n = 8), (2) with PVH (n = 8), (3) with PVH and thrombosis (n = 8). Time to PSE and PRE and arterial liver perfusion (ALP), portal-venous liver perfusion (PLP) and hepatic perfusion-index (HPI) of the liver and HCC derived from PSE- versus PRE-based modelling were compared between the groups. Time to PSE was significantly longer in PVH groups 2 and 3 (P = 0.02), whereas PRE was similar in groups 1, 2 and 3 (P > 0.05). In group 1, liver and HCC perfusion parameters were similar for PSE- and PRE-based modelling (all P > 0.05), whereas significant differences were seen for PLP and HPI (liver only) in group 2 and ALP in group 3 (all P < 0.05). PSE is delayed in patients with PVH, resulting in a miscalculation of PSE-based P-CT parameters. Maximum slope-based P-CT might be improved by replacing PSE with PRE-modelling, whereas the difference between PSE and PRE might serve as a non-invasive biomarker of PVH. (orig.)

A combination therapy with preoperative full-dose gemcitabine, concurrent 3-dimensional conformal radiation, surgery and postoperative liver perfusion chemotherapy for pancreatic cancer

International Nuclear Information System (INIS)

Ohigashi, Hiroaki; Eguchi, Hidetoshi; Takahashi, Hidenori

2009-01-01

Due to the high incidence of local recurrence and liver metastasis, long-term outcomes for patients after resection of pancreatic cancer are extremely poor. For improving the survival of the patients, a combination of preoperative chemoradiation, surgery, and postoperative liver-perfusion chemotherapy (LPC) were performed. Postoperative histopathologic study revealed a marked degenerative change in cancer tissue, showing negative surgical margins (R0) in 98% of patients and negative nodal involvement in 85% of patients. The 5-year survival rate after pancreatectomy was 56%, with low incidences of both local recurrence (11%) and liver metastasis (9%). This combination therapy were able to effectively reduce the incidence of both local and liver recurrence and improved long-term outcomes for patients with T3-4 cancers of the pancreas. (author)

Induction of Inducible Nitric Oxide Synthase by Lipopolysaccharide and the Influences of Cell Volume Changes, Stress Hormones and Oxidative Stress on Nitric Oxide Efflux from the Perfused Liver of Air-Breathing Catfish, Heteropneustes fossilis.

Directory of Open Access Journals (Sweden)

Mahua G Choudhury

Full Text Available The air-breathing singhi catfish (Heteropneustes fossilis is frequently being challenged by bacterial contaminants, and different environmental insults like osmotic, hyper-ammonia, dehydration and oxidative stresses in its natural habitats throughout the year. The main objectives of the present investigation were to determine (a the possible induction of inducible nitric oxide synthase (iNOS gene with enhanced production of nitric oxide (NO by intra-peritoneal injection of lipopolysaccharide (LPS (a bacterial endotoxin, and (b to determine the effects of hepatic cell volume changes due to anisotonicity or by infusion of certain metabolites, stress hormones and by induction of oxidative stress on production of NO from the iNOS-induced perfused liver of singhi catfish. Intra-peritoneal injection of LPS led to induction of iNOS gene and localized tissue specific expression of iNOS enzyme with more production and accumulation of NO in different tissues of singhi catfish. Further, changes of hydration status/cell volume, caused either by anisotonicity or by infusion of certain metabolites such as glutamine plus glycine and adenosine, affected the NO production from the perfused liver of iNOS-induced singhi catfish. In general, increase of hydration status/cell swelling due to hypotonicity caused decrease, and decrease of hydration status/cell shrinkage due to hypertonicity caused increase of NO efflux from the perfused liver, thus suggesting that changes in hydration status/cell volume of hepatic cells serve as a potent modulator for regulating the NO production. Significant increase of NO efflux from the perfused liver was also observed while infusing the liver with stress hormones like epinephrine and norepinephrine, accompanied with decrease of hydration status/cell volume of hepatic cells. Further, oxidative stress, caused due to infusion of t-butyl hydroperoxide and hydrogen peroxide separately, in the perfused liver of singhi catfish, resulted

Modulation of the sympathetic nerve action on carbohydrate and ketone body metabolism by fatty acids, glucagon und insulin in perfused rat liver

NARCIS (Netherlands)

Küster, J.; Beuers, U.; JUNGERMANN, K.

1989-01-01

Rat liver was perfused in situ via the portal vein without recirculation: 1) Nerve stimulation (20 Hz, 2 ms, 20 V) increased glucose output and shifted lactate uptake to output; the alterations were diminished by oleate but not octanoate. 2) Glucagon (1nM) stimulated glucose output maximally also in

Quantitative hepatic CT perfusion measurement: Comparison of Couinaud's hepatic segments with dual-source 128-slice CT

Energy Technology Data Exchange (ETDEWEB)

Wang, Xuan [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China); Xue, Hua-dan, E-mail: bjdanna95@hotmail.com [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China); Jin, Zheng-yu, E-mail: jin_zhengyu@163.com [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China); Su, Bai-yan; Li, Zhuo; Sun, Hao; Chen, Yu; Liu, Wei [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China)

2013-02-15

Purpose: To compare the quantitative liver computed tomography perfusion (CTP) differences among eight hepatic segments. Materials and methods: This retrospective study was based on 72 acquired upper abdomen CTP scans for detecting suspected pancreas tumor. Patients with primary or metastatic liver tumor, any focal liver lesions except simple cyst (<3 cm in diameter), history of liver operation or splenectomy, evidence of liver cirrhosis or invasion of portal vein were excluded. The final analysis included 50 patients (M:F = 21:29, mean age = 43.2 years, 15–76 years). Arterial liver perfusion (ALP), portal-venous perfusion (PVP), total hepatic perfusion (THP = ALP + PVP), and hepatic perfusion index (HPI) of each hepatic segment were calculated and compared by means of one-way analysis of variance (ANOVA) and the Bonferonni correction method. Results: Compared to hepatic segments 5, 6, 7 and 8, segments 2 and 3 showed a tendency of higher ALPs, lower PVPs, and higher HPIs, most of which were statistically significant (p < 0.05). Hepatic segments 1 and 4 had higher mean values of ALP and HPI and lower mean values of PVP than segments 5, 6, 7 and 8 as well, although no significant differences were detected except for ALP and HPI for liver segments 1 and 7 (p = 0.001 and 0.035 respectively), and ALP for liver segments 1 and 5 (p = 0.039). Higher ALP and HPI were showed in hepatic segment 3 compared to segment 4 (p = 0.000 and 0.000 respectively). No significant differences were found for THP among eight segments. Conclusions: Intra-hepatic perfusion differences exist in normal hepatic parenchyma especially between lateral sector (segments 2 and 3) and right lobe (segments 5, 6, 7 and 8). This might have potential clinical significance in liver-perfusion-related protocol design and result analysis.

Evaluation of liver parenchyma and perfusion using dynamic contrast-enhanced computed tomography and contrast-enhanced ultrasonography in captive green iguanas (Iguana iguana) under general anesthesia.

Science.gov (United States)

Nardini, Giordano; Di Girolamo, Nicola; Leopardi, Stefania; Paganelli, Irene; Zaghini, Anna; Origgi, Francesco C; Vignoli, Massimo

2014-05-13

Contrast-enhanced diagnostic imaging techniques are considered useful in veterinary and human medicine to evaluate liver perfusion and focal hepatic lesions. Although hepatic diseases are a common occurrence in reptile medicine, there is no reference to the use of contrast-enhanced ultrasound (CEUS) and contrast-enhanced computed tomography (CECT) to evaluate the liver in lizards. Therefore, the aim of this study was to evaluate the pattern of change in echogenicity and attenuation of the liver in green iguanas (Iguana iguana) after administration of specific contrast media. An increase in liver echogenicity and density was evident during CEUS and CECT, respectively. In CEUS, the mean ± SD (median; range) peak enhancement was 19.9% ± 7.5 (18.3; 11.7-34.6). Time to peak enhancement was 134.0 ± 125.1 (68.4; 59.6-364.5) seconds. During CECT, first visualization of the contrast medium was at 3.6 ± 0.5 (4; 3-4) seconds in the aorta, 10.7 ± 2.2 (10.5; 7-14) seconds in the hepatic arteries, and 15 ± 4.5 (14.5; 10-24) seconds in the liver parenchyma. Time to peak was 14.1 ± 3.4 (13; 11-21) and 31 ± 9.6 (29; 23-45) seconds in the aorta and the liver parenchyma, respectively. CEUS and dynamic CECT are practical means to determine liver hemodynamics in green iguanas. Distribution of contrast medium in iguana differed from mammals. Specific reference ranges of hepatic perfusion for diagnostic evaluation of the liver in iguanas are necessary since the use of mammalian references may lead the clinician to formulate incorrect diagnostic suspicions.

Uptake and intracellular fate of [14C]sucrose-insulin in perfused rat livers

International Nuclear Information System (INIS)

Surmacz, C.A.; Wert, J.J. Jr.; Ward, W.F.; Mortimore, G.E.

1988-01-01

Insulin was covalently linked to [ 14 C]sucrose by means of cyanuric chloride to provide a label that would remain entrapped within the vacuolar system. The uptake of the conjugate by the perfused rat liver was rapid, competitively inhibited by native insulin, and abolished by alkali denaturation. As assessed by its distribution on self-generating gradients of colloidal silica-povidone, label in lysosome-enriched samples of liver taken at different times after the addition of the conjugate moved progressively during 15 min from the plasma membrane into an intermediate peak and then to dense lysosomal fractions. After 30-60 min, the label had equilibrated throughout the lysosomal-vacuolar system. The initial movement from the plasma membrane to the intermediate peak occurred between 2 and 5 min. Because label in the peak could be physically separated from the lysosomal marker, β-acetylglucosaminidase, by dispersing the sample through the gradient mixture before centrifugation rather than layering it, the authors concluded that the intermediate particles in question were not lysosomal in nature. On gel-filtration chromatography, label extracted from the intermediate peak did not move with insulin but rather as a broad band of lower molecular weight products, suggesting that insulin is subject to early proteolytic attack within a nonlysosomal compartment

Uptake and intracellular fate of [14C]sucrose-insulin in perfused rat livers.

Science.gov (United States)

Surmacz, C A; Wert, J J; Ward, W F; Mortimore, G E

1988-07-01

Insulin was covalently linked to [14C]sucrose by means of cyanuric chloride to provide a label that would remain entrapped within the vacuolar system. The uptake of the conjugate by the perfused rat liver was rapid (half-life = 2.9 min), competitively inhibited by native insulin, and abolished by alkali denaturation. As assessed by its distribution on self-generating gradients of colloidal silica-povidone, label in lysosome-enriched samples of liver taken at different times after the addition of the conjugate moved progressively during 15 min from the plasma membrane into an intermediate peak and then to dense lysosomal fractions. After 30-60 min, the label had equilibrated throughout the lysosomal-vacuolar system. The initial movement from the plasma membrane to the intermediate peak occurred between 2 and 5 min. Because label in the peak could be physically separated from the lysosomal marker, beta-acetylglucosaminidase, by dispersing the sample through the gradient mixture before centrifugation rather than layering it, we concluded that the intermediate particles in question were not lysosomal in nature. On gel-filtration chromatography, label extracted from the intermediate peak did not move with insulin but rather as a broad band of lower molecular weight products, suggesting that insulin is subject to early proteolytic attack within a nonlysosomal compartment.

Hepatic parenchymal perfusion abnormalities after pancreaticobiliary surgery. Evaluation with dynamic helical CT

International Nuclear Information System (INIS)

Mitsuzaki, K.; Yamashita, Y.; Ogata, I.; Nishiharu, T.; Urata, J.; Takahashi, M.

1998-01-01

Purpose: To evaluate perfusion abnormalities of the liver after pancreaticobiliary surgery. Material and Methods: We retrospectively evaluated 128 patients with pancreaticobiliary malignant tumors who had been examined both before and after surgery by means of helical CT of the liver. An infusion of 3 ml/s of 60% nonionic contrast material was followed by helical CT of the liver in a sequential arterial phase, portal venous phase, and equilibrium phase. Results: Of 128 patients, we followed 97. In 21 patients (22%) we found 47 lesions with perfusion abnormalities that were detected 1-33 months (mean 6.6 months) after the operation. All patients were asymptomatic. The shape of each perfusion abnormality was characterized as geographic (n=23, 47%), wedge-shaped (n=21, 45%), or round (n=3, 8%). The abnormalities were seen in the arterial phase in 46 lesions (98%), in the portal venous phase in 18 lesions (38%), and in the equilibrium phase in 1 lesion (0.2%). In all lesions, the size either decreased spontaneously, or it remained unchanged for more than one year. Conclusion: Perfusion abnormalities of the liver may occur in patients who undergo pancreaticobiliary surgery. These findings should not be confused with hypervascular metastases. (orig.)

Hepatic parenchymal perfusion abnormalities after pancreaticobiliary surgery. Evaluation with dynamic helical CT

Energy Technology Data Exchange (ETDEWEB)

Mitsuzaki, K.; Yamashita, Y.; Ogata, I.; Nishiharu, T.; Urata, J.; Takahashi, M. [Kumamoto Univ., School of Medicine, Dept. of Radiology (Japan)

1998-05-01

Purpose: To evaluate perfusion abnormalities of the liver after pancreaticobiliary surgery. Material and Methods: We retrospectively evaluated 128 patients with pancreaticobiliary malignant tumors who had been examined both before and after surgery by means of helical CT of the liver. An infusion of 3 ml/s of 60% nonionic contrast material was followed by helical CT of the liver in a sequential arterial phase, portal venous phase, and equilibrium phase. Results: Of 128 patients, we followed 97. In 21 patients (22%) we found 47 lesions with perfusion abnormalities that were detected 1-33 months (mean 6.6 months) after the operation. All patients were asymptomatic. The shape of each perfusion abnormality was characterized as geographic (n=23, 47%), wedge-shaped (n=21, 45%), or round (n=3, 8%). The abnormalities were seen in the arterial phase in 46 lesions (98%), in the portal venous phase in 18 lesions (38%), and in the equilibrium phase in 1 lesion (0.2%). In all lesions, the size either decreased spontaneously, or it remained unchanged for more than one year. Conclusion: Perfusion abnormalities of the liver may occur in patients who undergo pancreaticobiliary surgery. These findings should not be confused with hypervascular metastases. (orig.).

The preparation of native livers for morphological studies.

Science.gov (United States)

Ludwig, J; Ottman, D M; Eichmann, T J

1994-09-01

We describe experiences with a perfusion fixation apparatus that was used for studies on approximately 500 native livers. Immediately after excision of the specimen, small samples from needle biopsy specimens are obtained for snap-freezing and the remaining portions of the specimens are fixed and embedded in paraffin. In the laboratory, the portal vein and, if possible, the hepatic artery or common hepatic duct are then cannulated and the livers are perfused for 3 days with Kaiserling's solution. An electric pump drives the perfusion apparatus and allows the formalin to cascade through stacked plastic containers, with the specimens attached to the inflow nozzles for the fixative. Eight or more livers (or other organs and specimens) can be accommodated simultaneously. Angiograms or cholangiograms can be prepared before or after fixation; we prefer the latter. The livers are then sliced with an extra-long knife, which minimizes cutting marks. Most preparations are thoroughly fixed and yield excellent specimens, not only for routine microscopic study but also for special methods such as scanning electron microscopy and trace metal analysis. The liver slices can be stored indefinitely, which allows long-range collection for routine review or research purposes. In approximately 5% of the cases, specimens cannot be perfused properly and thus are unsuitable for this type of preparation. With autopsy specimens this percentage is higher, probably because of postmortem clotting. Gravity perfusion of the livers before placement into the apparatus generally enables identification of specimens with incomplete filling of the vasculature.

Carbon-14 tracer studies in rat-liver perfusion experiments under conditions of gluconeogenesis from lactate and pyruvate

International Nuclear Information System (INIS)

Muellhofer, G.; Schwab, A.; Mueller, C.; Stetten, C. von; Gruber, E.

1977-01-01

The intracellular events in the metabolic pathway of gluconeogenesis from lactate and pyruvate in liver tissue were assumed to be understood. Nevertheless the results of several 14 C-tracer experiments gave rise to the postulation of still unknown intracellular interactions under this condition. A contribution was made to the solution of this problem by using different 14 C labelled tracers such as [1- 14 C]lactate or pyruvate and [2- 14 C]lactate or pyruvate. [ 14 C]bicarbonate and [1- 14 C]-octanoate in perfusion experiments with livers from rats under conditions of gluconeogenesis from lactate and pyruvate. The 14 C labelling patterns of intracellular metabolities such as malate, citrate, phosphoenolpyruvate, phosphoglycerate and newly synthesized glucose were analysed under different conditions. A comparison with values calculated by using metabolic models based on the generally accepted concepts of intracellular interactions showed some fundamental discrepancies which justify the postulation. (orig./MG) [de

Kinetics of the transformation of n-propyl gallate and structural analogs in the perfused rat liver

International Nuclear Information System (INIS)

Eler, Gabrielle Jacklin; Santos, Israel Souza; Giaretta de Moraes, Amarilis; Mito, Márcio Shigueaki; Comar, Jurandir Fernando; Peralta, Rosane Marina; Bracht, Adelar

2013-01-01

n-Propyl gallate and its analogs are used in foods and other products to prevent oxidation. In the liver the compound exerts several harmful effects, especially gluconeogenesis inhibition. The mode of transport and distribution of n-propyl gallate and its kinetics of biotransformation have not yet been investigated. To fill this gap the transformation, transport and distribution of n-propyl gallate and two analogs were investigated in the rat liver. Isolated perfused rat liver was used. n-Propyl gallate, methyl gallate, n-octyl gallate and transformation products were quantified by high pressure-liquid chromatography coupled to fluorescence detection. The interactions of n-propyl gallate and analogs with the liver presented three main characteristics: (1) the hydrolytic release of gallic acid from n-propyl gallate and methyl gallate was very fast compared with the subsequent transformations of the gallic acid moiety; (2) transport of the esters was very fast and flow-limited in contrast to the slow and barrier-limited transport of gallic acid; (3) the apparent distribution volume of n-propyl gallate, but probably also of methyl gallate and n-octyl gallate, greatly exceeded the water space in the liver, contrary to the gallic acid space which is smaller than the water space. It can be concluded that at low portal concentrations (< 50 μM) the gallic acid esters are 100% extracted during a single passage through the liver, releasing mainly gallic acid into the systemic circulation. For the latter a considerable time is required until complete biotransformation. The exposure of the liver to the esters, however, is quite prolonged due to extensive intracellular binding. - Highlights: • The liver binds very strongly n-propyl gallate and releases basically gallic acid. • n-propyl gallate and analogs undergo concentrative flow-limited distribution. • Gallic acid undergoes barrier-limited distribution and is slowly transformed. • The long residence time of n

Kinetics of the transformation of n-propyl gallate and structural analogs in the perfused rat liver

Energy Technology Data Exchange (ETDEWEB)

Eler, Gabrielle Jacklin; Santos, Israel Souza; Giaretta de Moraes, Amarilis; Mito, Márcio Shigueaki; Comar, Jurandir Fernando; Peralta, Rosane Marina; Bracht, Adelar, E-mail: adebracht@uol.com.br

2013-11-15

n-Propyl gallate and its analogs are used in foods and other products to prevent oxidation. In the liver the compound exerts several harmful effects, especially gluconeogenesis inhibition. The mode of transport and distribution of n-propyl gallate and its kinetics of biotransformation have not yet been investigated. To fill this gap the transformation, transport and distribution of n-propyl gallate and two analogs were investigated in the rat liver. Isolated perfused rat liver was used. n-Propyl gallate, methyl gallate, n-octyl gallate and transformation products were quantified by high pressure-liquid chromatography coupled to fluorescence detection. The interactions of n-propyl gallate and analogs with the liver presented three main characteristics: (1) the hydrolytic release of gallic acid from n-propyl gallate and methyl gallate was very fast compared with the subsequent transformations of the gallic acid moiety; (2) transport of the esters was very fast and flow-limited in contrast to the slow and barrier-limited transport of gallic acid; (3) the apparent distribution volume of n-propyl gallate, but probably also of methyl gallate and n-octyl gallate, greatly exceeded the water space in the liver, contrary to the gallic acid space which is smaller than the water space. It can be concluded that at low portal concentrations (< 50 μM) the gallic acid esters are 100% extracted during a single passage through the liver, releasing mainly gallic acid into the systemic circulation. For the latter a considerable time is required until complete biotransformation. The exposure of the liver to the esters, however, is quite prolonged due to extensive intracellular binding. - Highlights: • The liver binds very strongly n-propyl gallate and releases basically gallic acid. • n-propyl gallate and analogs undergo concentrative flow-limited distribution. • Gallic acid undergoes barrier-limited distribution and is slowly transformed. • The long residence time of n

Possible role of the scintigraphic estimation of the relative liver perfusion in the choice of treatment of liver carcinomas

International Nuclear Information System (INIS)

Artiko, V.; Obradovic, V.; Davidovic, B.; Petrovic, N.; Vlajkoviae, M.; Kostic, K.

2005-01-01

Full text: In the pre-evaluation and diagnosis of the patients with liver tumors, significant nuclear medicine methods used are: radiocolloid, blood pool, hepatobiliary scintigraphy, angioscintigraphy with radiolabeled microspheres as well as 'first pass' radionuclide angiography, which can precede all of the above mentioned methods, during single injection application. The aim of the study is evaluation of the possible role of the scintigraphic estimation of the relative liver perfusion in the choice of treatment of liver carcinomas. The study was performed in 120 patients: 24 controls (C), 35 with benign liver tumors (BT), 35 with hepatocellular carcinomas (HCC), 19 with metastases of colorectal carcinomas (MCC) as well as 7 with metastases of other tumors (MOT-bronchus, lung carcinoma and lymphoma). 7/35 HCC had cavernous portal vein developed after tumor thrombosis, 2 had complete thrombosis and 5 had incomplete thrombosis (thrombosis of the either of portal venous branches (3) and incomplete portal venous thrombosis -2). 2/19 patients with MCC had cavernous portal vein developed after tumor thrombosis, 3 had complete portal venous occlusion and 4 incomplete thrombosis (thrombosis of the either of branches). The study was performed with ROTA scintillation camera and Micro Delta computer, during 60 sec (1f/sec) from i.v.application of 740 MBq 99mTc-pertecnetate. TA curves were generated using liver ROI, spleen ROI and left kidney ROI, and curves were generated. Hepatic perfusion index was calculated using slope analysis (Portal slope Ps and arterial slope As) method according to following formula HPI=Ps/(Ps+As). Complementary methods used were Doppler ultrasonography, CT, MRI, tumor marker assays (CEA, Ca19-9, AFP) laboratory analyses, pathohistological finding and clinical diagnosis. In C, HPI was 0.68±0.06 which did not differ from the value in BT (0.64 ±0.08) (p>0.05). However, in HCC ( X=0.26±0.20), and LM (X=0.40±0.28), HPI values were significantly

Effect of phenobarbital pretreatment on benzene biotransformation in the rat. Pt. 2. 9. 000 g supernatant and isolated perfused liver versus living rat

Energy Technology Data Exchange (ETDEWEB)

Gut, I.; Hatle, K.; Zizkova, L.

1981-03-01

Factors responsible for different quantitative effect of phenobarbital (PB) pretreatment on benzene metabolism to phenol in vivo and in vitro were studied in male Wistar rats. A more than 4-fold increase of benzene metabolism was observed with 9,000 g supernatant of liver homogenate, 2.8- to 4-fold increase with isolated perfused liver; phenol formation in vivo after oral benzene was increased by PB 2-fold, but only shortly following benzene administration and the enhancement rapidly diminished to 1.15-fold increase in the total excreted phenol. Benzene concentrations in 9,000 g supernatant incubations were 2 mM, those with isolated perfused livers were up to 4 mM, but those in blood in vivo were below 0.3 mM; the effect of PB induction in vivo disappeared along with decreasing benzene and increasing phenol blood concentrations which surpassed benzene 2-3 h after oral benzene administration. The effect of benzene concentration on the manifestation of PB induction is also supported by almost a 2-fold increased phenol formation in PB rats over controls in vivo after repeated administration of benzene. The elimination of radioactive metabolites of orally administered benzene-/sup 14/C, in urine was markedly inhibited by intraperitoneal administration of phenol, but not by pyrocatechol, resorcinol or hydroquinol suggesting that phenol might inhibit benzene metabolism in vivo especially when its concentration exceeds that of benzene.

Comparison of auricular and rectal temperature measurement in normothermic, hypothermic, and hyperthermic dogs.

Science.gov (United States)

Konietschke, U; Kruse, B D; Müller, R; Stockhaus, C; Hartmann, K; Wehner, A

2014-01-01

Measurement of rectal temperature is the most common method and considered gold standard for obtaining body temperature in dogs. So far, no study has been performed comparing agreement between rectal and auricular measurements in a large case series. The purpose of the study was to assess agreement between rectal and auricular temperature measurement in normothermic, hypothermic, and hyperthermic dogs with consideration of different environmental conditions and ear conformations. Reference values for both methods were established using 62 healthy dogs. Three hundred dogs with various diseases (220 normothermic, 32 hypothermic, 48 hyperthermic) were enrolled in this prospective study. Rectal temperature was compared to auricular temperature and differences in agreement with regard to environmental temperature, relative humidity, and different ear conformations (pendulous versus prick ears) were evaluated using Pearson's correlation coefficient and Bland-Altman analysis. Correlation between rec- tal and auricular temperature was significant (r: 0.892; p  temperature did not. Variation between the two methods of measuring body temperature was clinically unacceptable. Although measurement of auricular temperature is fast, simple, and well tolerated, this method provides a clinically unacceptable difference to the rectal measurement.

Radiofrequency Ablation (RFA): Development of a Flow Model for Bovine Livers for Extensive Bench Testing

International Nuclear Information System (INIS)

Lubienski, Andreas; Bitsch, Rudi G.; Lubienski, Katrin; Kauffmann, Guenter; Duex, Markus

2006-01-01

Purpose. To develop a flow model for bovine livers for extensive bench testing of technical improvements or procedure-related developments of radiofrequency ablation excluding animal experiments. Methods. The perfusion of bovine livers directly from the slaughterhouse was simulated in a liver perfusion tank developed for the experimental work. The liver perfusion medium used was a Tyrode solution prepared in accordance with physiologic criteria (as for liver transplants) which was oxygenated by an oxygenator and heated to 36.5 deg. C. Portal vein circulation was regulated via a flow- and pressure-controlled pump and arterial circulation using a dialysis machine. Flow rate and pressure were adjusted as for the physiology of a human liver converted to bovine liver conditions. The fluid discharged from the liver was returned into the perfusion system through the vena cava. Extendable precision swivel arms with the radiofrequency probe attached were mounted on the liver perfusion tank. RFA was conducted with the RF3000 generator and a 2 cm LeVeen needle (Boston Scientific, Ratingen, Germany) in a three-dimensional grid for precise localization of the generated thermolesions. Results. Four bovine livers weighing 8.4 ± 0.4 kg each were prepared, connected to the perfusion system, and consecutively perfused for the experiments. Mean arterial flow was 569 ± 43 ml/min, arterial pressure 120 mmHg, portovenous flow 1440 ± 305 ml/min, and portal pressure 10 mmHg. Macroscopic evaluation after the experiments revealed no thrombi within the hepatic vessels. A total of 136 RF thermolesions were generated with an average number of 34 per liver. Mean RF duration was 2:59 ± 2:01 min:sec with an average baseline impedance of 28.2 ± 3.4 ohms. The mean diameter of the thermolesions along the puncture channel was 22.98 ± 4.34 mm and perpendicular to the channel was 23.27 ± 4.82 mm. Conclusion. Extracorporeal perfusion of bovine livers with consecutive standardized RF ablation was

Assessment of intratumor hypoxia by integrated 18F-FDG PET / perfusion CT in a liver tumor model.

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Yong Wang

Full Text Available Hypoxia in solid tumors occurs when metabolic demands in tumor cells surpass the delivery of oxygenated blood. We hypothesize that the 18F-fluorodeoxyglucose (18F-FDG metabolism and tumor blood flow mismatch would correlate with tumor hypoxia.Liver perfusion computed tomography (CT and 18F-FDG positron emission tomography (PET imaging were performed in twelve rabbit livers implanted with VX2 carcinoma. Under CT guidance, a fiber optic probe was inserted into the tumor to measure the partial pressure of oxygen (pO2. Tumor blood flow (BF and standardized uptake value (SUV were measured to calculate flow-metabolism ratio (FMR. Tumor hypoxia was further identified using pimonidazole immunohistochemical staining. Pearson correlation analysis was performed to determine the correlation between the imaging parameters and pO2 and pimonidazole staining.Weak correlations were found between blood volume (BV and pO2 level (r = 0.425, P = 0.004, SUV and pO2 (r = -0.394, P = 0.007, FMR and pimonidazole staining score (r = -0.388, P = 0.031. However, there was stronger correlation between tumor FMR and pO2 level (r = 0.557, P < 0.001.FMR correlated with tumor oxygenation and pimonidazole staining suggesting it may be a potential hypoxic imaging marker in liver tumor.

13C NMR study of effects of fasting and diabetes on the metabolism of pyruvate in the tricarboxylic acid cycle and of the utilization of pyruvate and ethanol in lipogenesis in perfused rat liver

International Nuclear Information System (INIS)

Cohen, S.M.

1987-01-01

13 C NMR has been used to study the competition of pyruvate dehydrogenase with pyruvate carboxylase for entry of pyruvate into the tricarboxylic acid (TCA) cycle in perfused liver from streptozotocin-diabetic and normal donor rats. The relative proportion of pyruvate entering the TCA cycle by these two routes was estimated from the 13 C enrichments at the individual carbons of glutamate when [3- 13 C]alanine was the only exogenous substrate present. In this way, the proportion of pyruvate entering by the pyruvate dehydrogenase route relative to the pyruvate carboxylase route was determined to be 1:1.2 +/- 0.1 in liver from fed controls, 1:7.7 +/- 2 in liver from 24-fasted controls, and 1:2.6 +/- 0.3 in diabetic liver. Pursuant to this observation that conversion of pyruvate to acetyl coenzyme A (acetyl-CoA) was greatest in perfused liver from fed controls, the incorporation of 13 C label into fatty acids was monitored in this liver preparation. With the exception of the repeating methylene carbons, fatty acyl carbons labeled by [1- 13 C]acetyl-CoA (from [2- 13 C]pyruvate) gave rise to resonances distinguishable on the basis of chemical shift from those observed when label was introduced by [3- 13 C]alanine plus [2- 13 C]ethanol, which are converted to [2- 13 C]acetyl-CoA. Thus, measurement of 13 C enrichment at several specific sites in the fatty acyl chains in time-resolved spectra of perfused liver offers a novel way of monitoring the kinetics of the biosynthesis of fatty acids. In addition to obtaining the rate of lipogenesis, it was possible to distinguish the contributions of chain elongation from those of the de novo synthesis pathway and to estimate the average chain length of the 13 C-labeled fatty acids produced

C-arm CT for chemo-embolization of liver tumors

International Nuclear Information System (INIS)

Huppert, P.E.; Firlbeck, G.; Meissner, O.A.; Wietholtz, H.

2009-01-01

Local efficacy of transarterial chemo-embolization (TACE) is enhanced if selective treatment is performed. Selectivity of TACE mainly depends on vascular anatomy but also on the identification and catheterization of tumor feeding arteries. Correlation of vascular territories and target tumor volume in angiographic projection images is more difficult if tumors are not hypervascularized and contrast of liver parenchyma is inhomogeneous. C-arm CT offers the option of selective perfusion imaging via tumor-feeding arteries. This allows the comparison of perfusion images and baseline cross-sectional imaging to evaluate if tumors are covered completely by local treatment and to change the catheter position if necessary. Furthermore the uptake of embolization material, such as lipiodol can be checked by C-arm CT. In a prospective study of 75 TACE of liver tumors and liver metastases we evaluated the appropriateness of 85 catheter positions ready for delivery by perfusion C-arm CT and compared the diagnostic confidence of angiography and perfusion C-arm CT in terms of judgment of correct catheter position for the planned treatment. Diagnostic confidence was improved by perfusion C-arm CT in 55% of cases and in 11 cases (13%) catheter positions were inappropriate and had to be corrected. The reasons for catheter repositioning were incomplete coverage of the target tumor by perfusion volume (mismatch) in 6 cases, inappropriate perfusion of adjacent liver parenchyma in 2 cases and non-selective tumor perfusion via collateral arteries in 3 cases. C-arm CT allowed sufficient visualization of uptake of lipiodol in all cases evaluated. The diagnostic benefit of C-arm CT increases if tumors are treated more selectively, are not strongly hypervascular, are located centrally and if the enhancement of liver parenchyma is inhomogeneous. C-arm CT causes additional working time and contrast load, which is relatively low compared to angiography. Radiation exposure of 151 μGy per C

Advances in bioartificial liver assist devices.

Science.gov (United States)

Patzer, J F

2001-11-01

Rapid advances in development of bioartificial liver assist devices (BLADs) are exciting clinical interest in the application of BLAD technology for support of patients with acute liver failure. Four devices (Circe Biomedical HepatAssist, Vitagen ELAD, Gerlach BELS, and Excorp Medical BLSS) that rely on hepatocytes cultured in hollow-fiber membrane technology are currently in various stages of clinical evaluation. Several alternative approaches for culture and perfusion of hepatocytes have been evaluated in preclinical, large animal models of liver failure, or at a laboratory scale. Engineering design issues with respect to xenotransplantation, BLAD perfusion, hepatocyte functionality and culture maintenance, and ultimate distribution of a BLAD to a clinical site are delineated.

CT hepatic perfusion measurement: Comparison of three analytic methods

International Nuclear Information System (INIS)

Kanda, Tomonori; Yoshikawa, Takeshi; Ohno, Yoshiharu; Kanata, Naoki; Koyama, Hisanobu; Takenaka, Daisuke; Sugimura, Kazuro

2012-01-01

Objectives: To compare the efficacy of three analytic methods, maximum slope (MS), dual-input single-compartment model (CM) and deconvolution (DC), for CT measurements of hepatic perfusion and assess the effects of extra-hepatic systemic factors. Materials and methods: Eighty-eight patients who were suspected of having metastatic liver tumors underwent hepatic CT perfusion. The scans were performed at the hepatic hilum 7–77 s after administration of contrast material. Hepatic arterial and portal perfusions (HAP and HPP, ml/min/100 ml) and arterial perfusion fraction (APF, %) were calculated with the three methods, followed by correlation assessment. Partial correlation analysis was used to assess the effects on hepatic perfusion values by various factors such as age, sex, risk of cardiovascular diseases, arrival time of contrast material at abdominal aorta, transit time from abdominal aorta to hepatic parenchyma, and liver dysfunction. Results: Mean HAP of MS was significantly higher than DC. HPP of CM was significantly higher than MS and CM, and HPP of MS was significantly higher than DC. There was no significant difference in APF. HAP and APF showed significant and moderate correlations among the methods. HPP showed significant and moderate correlations between CM and DC, and poor correlation between MS and CM or DC. All methods showed weak correlations between HAP or APF and age or sex. Finally, MS showed weak correlations between HAP or HPP and arrival time or cardiovascular risks. Conclusions: Hepatic perfusion values arrived at with the three methods are not interchangeable. CM and DC are less susceptible to extra-hepatic systemic factors

Interactions of the heart and the liver

DEFF Research Database (Denmark)

Møller, Søren; Bernardi, Mauro

2013-01-01

There is a mutual interaction between the function of the heart and the liver and a broad spectrum of acute and chronic entities that affect both the heart and the liver. These can be classified into heart diseases affecting the liver, liver diseases affecting the heart, and conditions affecting...... the heart and the liver at the same time. In chronic and acute cardiac hepatopathy, owing to cardiac failure, a combination of reduced arterial perfusion and passive congestion leads to cardiac cirrhosis and cardiogenic hypoxic hepatitis. These conditions may impair the liver function and treatment should...... be directed towards the primary heart disease and seek to secure perfusion of vital organs. In patients with advanced cirrhosis, physical and/or pharmacological stress may reveal a reduced cardiac performance with systolic and diastolic dysfunction and electrophysical abnormalities termed cirrhotic...

Effects of insulin on perfused liver from streptozotocin-diabetic and untreated rats: 13C NMR assay of pyruvate kinase flux

International Nuclear Information System (INIS)

Cohen, S.M.

1987-01-01

The effects of insulin in vitro on perfused liver from streptozotocin-diabetic rats and their untreated littermates during gluconeogenesis from either [3- 13 C]alanine + ethanol or [2- 13 C]pyruvate + NH 4 Cl + ethanol were studied by 13 C NMR. A 13 C NMR determination of the rate of pyruvate kinase flux under steady-state conditions of active gluconeogenesis was developed; this assay includes a check on the reuse of recycled pyruvate. The preparations studied provided gradations of pyruvate kinase flux within the confines of the assay's requirement of active gluconeogenesis. By this determination, the rate of pyruvate kinase flux was 0.74 +/- 0.04 of the gluconeogenic rate in liver from 24-h-fasted controls; in liver from 12-h fasted controls, relative pyruvate kinase flux increased to 1.0 +/- 0.2. In diabetic liver, this flux was undetectable by the authors NMR method. Insulin's hepatic influence in vitro was greatest in the streptozotocin model of type 1 diabetes: upon treatment of diabetic liver with 7 nM insulin in vitro, a partial reversal of many of the differences noted between diabetic and control liver was demonstrated by 13 C NMR. A major effect of insulin in vitro upon diabetic liver was the induction of a large increase in the rate of pyruvate kinase flux, bringing relative and absolute fluxes up to the levels measured in 24-h-fasted controls. By way of comparison, the effects of ischemia on diabetic liver were studied by 13 C NMR to test whether changes in allosteric effectors under these conditions could also increase pyruvate kinase flux. A large increase in this activity was demonstrated in ischemic diabetic liver

Intralipid minimizes hepatocytes injury after anoxia-reoxygenation in an ex vivo rat liver model.

Science.gov (United States)

Stadler, Michaela; Nuyens, Vincent; Boogaerts, Jean G

2007-01-01

Ischemia-reperfusion injury is a determinant in liver injury occurring during surgical procedures, ischemic states, and multiple organ failure. The pre-existing nutritional status of the liver, i.e., fasting, might contribute to the extent of tissue injury. This study investigated whether Intralipid, a solution containing soybean oil, egg phospholipids, and glycerol, could protect ex vivo perfused livers of fasting rats from anoxia-reoxygenation injury. The portal vein was cannulated, and the liver was removed and perfused in a closed ex vivo system. Isolated livers were perfused with glucose 5.5 and 15 mM, and two different concentrations of Intralipid, i.e., 0.5:100 and 1:100 (v/v) Intralipid 10%:medium (n = 5 in each group). The experiment consisted of perfusion for 15 min, warm anoxia for 60 min, and reoxygenation during 60 min. Hepatic enzymes, potassium, glucose, lactate, bilirubin, dienes, trienes, and cytochrome-c were analyzed in perfusate samples. The proportion of glycogen in hepatocytes was determined in biopsies. Intralipid attenuated transaminases, lactate dehydrogenase, potassium, diene, and triene release in the perfusate (dose-dependant) during the reoxygenation phase when compared with glucose-treated groups. The concentration of cytochrome-c in the medium was the highest in the 5.5-mM glucose group. The glycogen content was low in all livers at the start of the experiment. Intralipid presents, under the present experimental conditions, a better protective effect than glucose in anoxia-reoxygenation injury of the rat liver.

Rat liver contains a limited number of binding sites for hepatic lipase

NARCIS (Netherlands)

G.C. Schoonderwoerd (Kees); A.J.M. Verhoeven (Adrie); H. Jansen (Hans)

1994-01-01

textabstractThe binding of hepatic lipase to rat liver was studied in an ex vivo perfusion model. The livers were perfused with media containing partially purified rat hepatic lipase or bovine milk lipoprotein lipase. The activity of the enzymes was determined in the

Goal-directed-perfusion in neonatal aortic arch surgery.

Science.gov (United States)

Cesnjevar, Robert Anton; Purbojo, Ariawan; Muench, Frank; Juengert, Joerg; Rueffer, André

2016-07-01

Reduction of mortality and morbidity in congenital cardiac surgery has always been and remains a major target for the complete team involved. As operative techniques are more and more standardized and refined, surgical risk and associated complication rates have constantly been reduced to an acceptable level but are both still present. Aortic arch surgery in neonates seems to be of particular interest, because perfusion techniques differ widely among institutions and an ideal form of a so called "total body perfusion (TBP)" is somewhat difficult to achieve. Thus concepts of deep hypothermic circulatory arrest (DHCA), regional cerebral perfusion (RCP/with cardioplegic cardiac arrest or on the perfused beating heart) and TBP exist in parallel and all carry an individual risk for organ damage related to perfusion management, chosen core temperature and time on bypass. Patient safety relies more and more on adequate end organ perfusion on cardiopulmonary bypass, especially sensitive organs like the brain, heart, kidney, liver and the gut, whereby on adequate tissue protection, temperature management and oxygen delivery should be visualized and monitored.

Hepatic sinusoid is not well-stirred: estimation of the degree of axial mixing by analysis of lobular concentration gradients formed during uptake of thyroxine by the perfused rat liver

International Nuclear Information System (INIS)

Weisiger, R.A.; Mendel, C.M.; Cavalieri, R.R.

1986-01-01

Two general models have been proposed for predicting the effects of metabolism, protein binding, and plasma flow on the removal of drugs by the liver. These models differ in the degree of plasma mixing assumed to exist within each hepatic sinusoid. The venous equilibrium model treats the sinusoid as a single well-stirred compartment, whereas the sinusoidal model effectively breaks up the sinusoid into a large number of sequentially perfused compartments which do not exchange their contents except through plasma flow. As a consequence, the sinusoidal model, but not the venous equilibrium model, predicts that the concentration of highly extracted drugs will decline as the plasma flows through the hepatic lobule. To determine which of these alternative models best describes the hepatic uptake process, we looked for evidence that concentration gradients are formed during the uptake of [ 125 I]thyroxine by the perfused rat liver. Autoradiography of tissue slices after perfusion of the portal vein at physiologic flow rates with protein-free buffer containing [ 125 I]thyroxine demonstrated a rapid exponential fall in grain density with distance from the portal venule, declining by half for each 8% of the mean length of the sinusoid. Reversing the direction of perfusate flow reversed the direction of the autoradiographic gradients, indicating that they primarily reflect differences in the concentration of thyroxine within the hepatic sinusoids rather than differences in the uptake capacity of portal and central hepatocytes. Analysis of the data using models in which each sinusoid was represented by different numbers of sequentially perfused compartments (1-20) indicated that at least eight compartments were necessary to account for the magnitude of the gradients seen

Estimation of Radiation Exposure of 128-Slice 4D-Perfusion CT for the Assessment of Tumor Vascularity

Energy Technology Data Exchange (ETDEWEB)

Ketelsen, Dominik; Horger, Marius; Buchgeister, Markus; Fenchel, Michael; Thomas, Christoph; Boehringer, Nadine; Schulze, Maximilian; Tsiflikas, Ilias; Claussen, Claus D.; Heuschmid, Martin [University Hospital Tuebingen, Tuebingen (Germany)

2010-10-15

We aimed to estimate the effective dose of 4D-Perfusion-CT protocols of the lung, liver, and pelvis for the assessment of tumor vascularity. An Alderson-Rando phantom equipped with thermoluminescent dosimeters was used to determine the effective dose values of 4D Perfusion-CT. Phantom measurements were performed on a 128-slice single source scanner in adaptive 4D-spiral-mode with bidirectional table movement and a total scan range of 69 mm over a time period of nearly 120 seconds (26 scans). Perfusion measurements were simulated for the lung, liver, and pelvis under the following conditions: lung (80 kV, 60 mAs), liver (80 kV/80 mAs and 80 kV/120 mAs), pelvis (100 kV/80 mAs and 100 kV/120 mAs). Depending on gender, the evaluated body region and scan protocol, an effective whole-body dose between 2.9-12.2 mSv, was determined. The radiation exposure administered to gender-specific organs like the female breast tissue (lung perfusion) or to the ovaries (pelvic perfusion) led to an increase in the female specific dose by 86% and 100% in perfusion scans of the lung and the pelvis, respectively. Due to a significant radiation dose of 4D-perfusion-CT protocols, the responsible use of this new promising technique is mandatory. Gender- and organ-specific differences should be considered for indication and planning of tumor perfusion scans

Characterisation of focal liver lesions with contrast enhanced ultrasonography

International Nuclear Information System (INIS)

Dietrich, Christoph F.

2004-01-01

Ultrasound contrast agents (USCA) have improved the detection rate of liver tumours in recent years. Conventional ultrasound has been reported to be relatively unreliable in the characterisation of liver tumours. SonoVue [reg] (Bracco Imaging Spa) has been shown to be particularly advantageous in the differentiation of benign and malignant liver tumours and, therefore, possibly represents a new cost-effective competitive alternative to other liver imaging modalities (e.g. computed tomography and magnetic resonance imaging), thus allowing these important technologies to be available for other indications (e.g. brain, thorax). More detailed and specific liver tumour characterisation is possible in about 80% of liver tumours due to typical vascularity and perfusion patterns. The role of USCA for better characterisation, which is possible through the analysis of flow characteristics in real time, places a particular emphasis on agent use. Contrast enhanced real-time imaging techniques with SonoVue [reg] allow real-time analysis of tumour perfusion in patients with liver lesions. Liver tumours known to be hyperperfused in the arterial phase (e.g. focal nodular hyperplasia, hepatocellular adenoma and carcinoma, and hyperperfused metastases) can be better detected and characterised. Hypoperfused tumours (e.g. liver metastases of the gastrointestinal tract) can be recognised in the portal venous phase as less perfused 'black spots'. In this article we discuss liver tumour characterisation by contrast enhanced ultrasonography

Effect of phenobarbital on 131I-bromosulfophthalein metabolism of isolated perfused liver of rats with alpha-naphthylisothiocyanate-induced chloestasis

International Nuclear Information System (INIS)

Tapalaga, D.; Suciu, A.; Schvartz, M.; Duca, S.

1979-01-01

In order to establish whether the increased bromosulfophthalein (BSP) secretion in the bile following phenobarbital administration is the consequence of change in the bile output or of the enzymatic induction, the dynamics of the elimination of 131 I-BSP was studied in animals treated with alpha-naphthylisothiocyanate (ANIT) and pehnobarbital in the conditions of isolated perfused liver. At the same time the levels of the conjugation enzyme of BSP were also determined. It was noted that after phenobarbital the biliary elimination of 131 I-BSP is in correlation with the important increase of the output; in the animals treated with ANIT, on the other hand, the biliary excretion of BSP is minimal. The biliary elimination is directly proportional to the increase of the bile output and reflects the changes found in the perfusate. Our findings allow us to assume that the increased biliary BSP excretion is the consequence of the increase of the bile output and in a smaller extent the result of the stimulation of the BSP, conjugation with glutathion. (author)

Local and Global Function Model of the Liver

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Wang, Hesheng, E-mail: hesheng@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Feng, Mary [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Jackson, Andrew [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Ten Haken, Randall K.; Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Cao, Yue [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan (United States)

2016-01-01

Purpose: To develop a local and global function model in the liver based on regional and organ function measurements to support individualized adaptive radiation therapy (RT). Methods and Materials: A local and global model for liver function was developed to include both functional volume and the effect of functional variation of subunits. Adopting the assumption of parallel architecture in the liver, the global function was composed of a sum of local function probabilities of subunits, varying between 0 and 1. The model was fit to 59 datasets of liver regional and organ function measures from 23 patients obtained before, during, and 1 month after RT. The local function probabilities of subunits were modeled by a sigmoid function in relating to MRI-derived portal venous perfusion values. The global function was fitted to a logarithm of an indocyanine green retention rate at 15 minutes (an overall liver function measure). Cross-validation was performed by leave-m-out tests. The model was further evaluated by fitting to the data divided according to whether the patients had hepatocellular carcinoma (HCC) or not. Results: The liver function model showed that (1) a perfusion value of 68.6 mL/(100 g · min) yielded a local function probability of 0.5; (2) the probability reached 0.9 at a perfusion value of 98 mL/(100 g · min); and (3) at a probability of 0.03 [corresponding perfusion of 38 mL/(100 g · min)] or lower, the contribution to global function was lost. Cross-validations showed that the model parameters were stable. The model fitted to the data from the patients with HCC indicated that the same amount of portal venous perfusion was translated into less local function probability than in the patients with non-HCC tumors. Conclusions: The developed liver function model could provide a means to better assess individual and regional dose-responses of hepatic functions, and provide guidance for individualized treatment planning of RT.

Estimation of Radiation Exposure of 128-Slice 4D-Perfusion CT for the Assessment of Tumor Vascularity

Science.gov (United States)

Horger, Marius; Buchgeister, Markus; Fenchel, Michael; Thomas, Christoph; Boehringer, Nadine; Schulze, Maximilian; Tsiflikas, Ilias; Claussen, Claus D.; Heuschmid, Martin

2010-01-01

Objective We aimed to estimate the effective dose of 4D-Perfusion-CT protocols of the lung, liver, and pelvis for the assessment of tumor vascularity. Materials and Methods An Alderson-Rando phantom equipped with thermoluminescent dosimeters was used to determine the effective dose values of 4D-Perfusion-CT. Phantom measurements were performed on a 128-slice single-source scanner in adaptive 4D-spiral-mode with bidirectional table movement and a total scan range of 69 mm over a time period of nearly 120 seconds (26 scans). Perfusion measurements were simulated for the lung, liver, and pelvis under the following conditions: lung (80 kV, 60 mAs), liver (80 kV/80 mAs and 80 kV/120 mAs), pelvis (100 kV/80 mAs and 100 kV/120 mAs). Results Depending on gender, the evaluated body region and scan protocol, an effective whole-body dose between 2.9-12.2 mSv, was determined. The radiation exposure administered to gender-specific organs like the female breast tissue (lung perfusion) or to the ovaries (pelvic perfusion) led to an increase in the female specific dose by 86% and 100% in perfusion scans of the lung and the pelvis, respectively. Conclusion Due to a significant radiation dose of 4D-perfusion-CT protocols, the responsible use of this new promising technique is mandatory. Gender- and organ-specific differences should be considered for indication and planning of tumor perfusion scans. PMID:20808699

Insulin degradation products from perfused rat kidney

International Nuclear Information System (INIS)

Duckworth, W.C.; Hamel, F.G.; Liepnieks, J.; Peavy, D.; Frank, B.; Rabkin, R.

1989-01-01

The kidney is a major site for insulin metabolism, but the enzymes involved and the products generated have not been established. To examine the products, we have perfused rat kidneys with insulin specifically iodinated on either the A14 or the B26 tyrosine. Labeled material from both the perfusate and kidney extract was examined by Sephadex G50 and high-performance liquid chromatography (HPLC). In perfusate from a filtering kidney, 22% of the insulin-sized material was not intact insulin on HPLC. With the nonfiltering kidney, 10.6% was not intact insulin. Labeled material from HPLC was sulfitolyzed and reinjected on HPLC. By use of 125 I-iodo(A14)-insulin, almost all the degradation products contained an intact A-chain. By use of 125 I-iodo(B26)-insulin, several different B-chain-cleaved products were obtained. The material extracted from the perfused kidney was different from perfusate products but similar to intracellular products from hepatocytes, suggesting that cellular metabolism by kidney and liver are similar. The major intracellular product had characteristics consistent with a cleavage between the B16 and B17 amino acids. This product and several of the perfusate products are also produced by insulin protease suggesting that this enzyme is involved in the degradation of insulin by kidney

Hepatic artery perfusion imaging

International Nuclear Information System (INIS)

Thrall, J.H.; Gyves, J.W.; Ziessman, H.A.; Ensminger, W.D.

1985-01-01

Organ and region-selective intra-arterial chemotherapy have been used for more than two decades to treat malignant neoplasms in the extremities, head and neck region, pelvis, liver, and other areas. Substantial evidence of improved response to regional chemotherapy now exists, but there are stringent requirements for successful application of the regional technique. First, the chemotherapeutic agent employed must have appropriate pharmacokinetic and pharmacodynamic properties. Second, the drug must be reliably delivered to the tumor-bearing area. This typically requires an arteriographic assessment of the vascular supply of the tumor, followed by placement of a therapeutic catheter and confirmation that the ''watershed'' perfusion distribution from the catheter truly encompasses the tumor. Optimal catheter placement also minimizes perfusion of nontarget organs. Radionuclide perfusion imaging with technetium 99m-labeled particles, either microspheres or macroaggregates of albumin, has become the method of choice for making these assessments. Catheter placement itself is considered by many to represent a type of ''therapeutic'' intervention. However, once the catheter is in the hepatic artery the radionuclide perfusion technique can be used to assess adjunctive pharmacologic maneuvers designed to further exploit the regional approach to chemotherapy. This chapter presents the technetium Tc 99m macroaggregated albumin method for assessing catheter placement and the pharmacokinetic rationale for regional chemotherapy, and discusses two promising avenues for further intervention

CT perfusion imaging of the liver and the spleen in patients with cirrhosis: Is there a correlation between perfusion and portal venous hypertension?

International Nuclear Information System (INIS)

Talakic, Emina; Schoellnast, Helmut; Schaffellner, Silvia; Kniepeiss, Daniela; Mueller, Helmut; Stauber, Rudolf; Quehenberger, Franz

2017-01-01

To correlate hepatic and splenic CT perfusion parameters with hepatic venous pressure gradient (HVPG) measurements in patients with cirrhosis. Twenty-one patients with cirrhosis (males, 17; females, 4; mean ± SD age, 57 ± 7 years) underwent hepatic and splenic perfusion CT on a 320-detector row volume scanner as well as invasive measurement of HVPG. Different CT perfusion algorithms (maximum slope analysis and Patlak plot) were used to measure hepatic arterial flow (HAF), portal venous flow (PVF), hepatic perfusion index (HPI), splenic arterial flow (SAF), splenic blood volume (SBV) and splenic clearance (SCL). Hepatic and splenic perfusion parameters were correlated with HVPG, and sensitivity and specificity for detection of severe portal hypertension (≥12 mmHg) were calculated. The Spearman correlation coefficient was -0.53 (p < 0.05) between SAF and HVPG, and -0.68 (p < 0.01) between HVPG and SCL. Using a cut-off value of 125 ml/min/100 ml for SCL, sensitivity for detection of a HVPG of ≥12 mmHg was 94%, and specificity 100%. There was no significant correlation between hepatic perfusion parameters and HVPG. CT perfusion in patients with cirrhosis showed a strong correlation between SCL and HVPG and may be used for detection of severe portal hypertension. (orig.)

CT perfusion imaging of the liver and the spleen in patients with cirrhosis: Is there a correlation between perfusion and portal venous hypertension?

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Talakic, Emina; Schoellnast, Helmut [Medical University of Graz, Division of General Radiology, Department of Radiology, Graz (Austria); Schaffellner, Silvia; Kniepeiss, Daniela; Mueller, Helmut [Medical University of Graz, Department of Surgery, Division of Transplantation Surgery, Graz (Austria); Stauber, Rudolf [Medical University of Graz, Department of Internal Medicine, Division of Gastoenterology and Hepatology, Graz (Austria); Quehenberger, Franz [Medical University of Graz, Institute for Medical Informatics, Statistics and Documentation, Graz (Austria)

2017-10-15

To correlate hepatic and splenic CT perfusion parameters with hepatic venous pressure gradient (HVPG) measurements in patients with cirrhosis. Twenty-one patients with cirrhosis (males, 17; females, 4; mean ± SD age, 57 ± 7 years) underwent hepatic and splenic perfusion CT on a 320-detector row volume scanner as well as invasive measurement of HVPG. Different CT perfusion algorithms (maximum slope analysis and Patlak plot) were used to measure hepatic arterial flow (HAF), portal venous flow (PVF), hepatic perfusion index (HPI), splenic arterial flow (SAF), splenic blood volume (SBV) and splenic clearance (SCL). Hepatic and splenic perfusion parameters were correlated with HVPG, and sensitivity and specificity for detection of severe portal hypertension (≥12 mmHg) were calculated. The Spearman correlation coefficient was -0.53 (p < 0.05) between SAF and HVPG, and -0.68 (p < 0.01) between HVPG and SCL. Using a cut-off value of 125 ml/min/100 ml for SCL, sensitivity for detection of a HVPG of ≥12 mmHg was 94%, and specificity 100%. There was no significant correlation between hepatic perfusion parameters and HVPG. CT perfusion in patients with cirrhosis showed a strong correlation between SCL and HVPG and may be used for detection of severe portal hypertension. (orig.)

Effect of post-exercise hydrotherapy water temperature on subsequent exhaustive running performance in normothermic conditions.

Science.gov (United States)

Dunne, Alan; Crampton, David; Egaña, Mikel

2013-09-01

Despite the widespread use of cold water immersion (CWI) in normothermic conditions, little data is available on its effect on subsequent endurance performance. This study examined the effect of CWI as a recovery strategy on subsequent running performance in normothermic ambient conditions (∼22°C). Nine endurance-trained men completed two submaximal exhaustive running bouts on three separate occasions. The running bouts (Ex1 and Ex2) were separated by 15min of un-immersed seated rest (CON), hip-level CWI at 8°C (CWI-8) or hip-level CWI at 15°C (CWI-15). Intestinal temperature, blood lactate and heart rate were recorded throughout and V˙O2, running economy and exercise times were recorded during the running sessions. Running time to failure (min) during Ex2 was significantly (p<0.05, ES=0.7) longer following CWI-8 (27.7±6.3) than CON (23.3±5) but not different between CWI-15 (26.3±3.4) and CON (p=0.06, ES=0.7) or CWI-8 and CWI-15 (p=0.4, ES=0.2). Qualitative analyses showed a 95% and 89% likely beneficial effect of CWI-8 and CWI-15 during Ex2 compared with CON, respectively. Time to failure during Ex2 was significantly shorter than Ex1 only during the CON condition. Intestinal temperature and HR were significantly lower for most of Ex2 during CWI-8 and CWI-15 compared with CON but they were similar at failure for the three conditions. Blood lactate, running economy and V˙O2 were not altered by CWI. These data indicate that a 15min period of cold water immersion applied between repeated exhaustive exercise bouts significantly reduces intestinal temperature and enhances post-immersion running performance in normothermic conditions. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Intrahepatic arterioportal shunting and anomalous venous drainage: understanding the CT features in the liver

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Breen, David J.; Rutherford, Elizabeth E.; Stedman, Brian; Lee-Elliott, Catherine; Hacking, C. Nigel [Southampton University Hospitals NHS Trust, Department of Radiology, Southampton, Hampshire (United Kingdom)

2004-12-01

The increased use of high-contrast volume, arterial-phase studies of the liver has demonstrated the frequent occurrence of arterioportal shunts within both the cirrhotic and non-cirrhotic liver. This article sets out to explain the underlying microcirculatory mechanisms behind these commonly encountered altered perfusion states. Similarly, well-recognised portal perfusion defects occur around the perifalciform and perihilar liver and are largely caused by anomalous venous drainage via the paraumbilical and parabiliary venous systems. The underlying anatomy will be discussed and illustrated. These vascular anomalies are all caused by or result in diminished portal perfusion and are often manifest in the setting of portal venous thrombosis. The evolving concept of zonal re-perfusion following portal vein thrombosis will be discussed. (orig.)

Hepatic bilirubin uptake in the isolated perfused rat liver is not facilitated by albumin binding

International Nuclear Information System (INIS)

Stollman, Y.R.; Gaertner, U.; Theilmann, L.; Ohmi, N.; Wolkoff, A.W.

1983-01-01

Bilirubin uptake by the liver has kinetic characteristics which suggest carrier-mediation. Bilirubin is readily bound to albumin. A liver cell surface receptor for albumin has been postulated. The present study was designed to examine directly whether albumin facilitates the hepatic uptake of bilirubin and whether uptake of bilirubin depends on binding to albumin. Rat liver was perfused with a protein-free fluorocarbon medium, and single-pass uptake of 1, 10, or 200 nmol of [ 3 H]bilirubin was determined after injection as an equimolar complex with 125 I-albumin, with 125 I-ligandin, or free with only a [ 14 C]sucrose reference. Uptake of 10 nmol of [ 3 H]bilirubin was 67.5 +/- 3.7% of the dose when injected with 125 I-albumin, 67.4 +/- 6.5% when injected with 125 I-ligandin, and 74.9 +/- 2.4% when injected with [ 14 C]sucrose (P greater than 0.1). At 200 nmol, uptake fell to 46.4 +/- 3.1% ( 125 I-albumin) and 63.3 +/- 3.4% [( 14 C]sucrose) of injected [ 3 H]bilirubin (P less than 0.01), which suggests saturation of the uptake mechanism. When influx was quantitated by the model of Goresky, similar results were obtained. When [ 3 H]bilirubin was injected simultaneously with equimolar 125 I-albumin and a [ 14 C]sucrose reference, there was no delay in 125 I-albumin transit as compared with that of [ 14 C]sucrose. This suggested that the off-rate of albumin from a putative hepatocyte receptor would have to be very rapid, which is unusual for high affinity receptor-ligand interaction. There was no evidence for facilitation of bilirubin uptake by binding to albumin or for interaction of albumin with a liver cell surface receptor. These results suggest that the hepatic bilirubin uptake mechanism is one of high affinity which can extract bilirubin from circulating carriers such as albumin, ligandin, or fluorocarbon

Red blood cells augment transport of reactive metabolites of monocrotaline from liver to lung in isolated and tandem liver and lung preparations

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Pan, L.C.; Lame, M.W.; Morin, D.; Wilson, D.W.; Segall, H.J. (Department of Veterinary Pharmacology, University of California, Davis (United States))

1991-09-01

Monocrotaline (MCT) is a pyrrolizidine alkaloid that causes pulmonary hypertension in rats by mechanisms which remain largely unknown. MCT is thought to be activated in the liver to a reactive intermediate that is transported to the lung where it causes endothelial injury. The authors previous pharmacokinetic work demonstrated significant sequestration of radioactivity in red blood cells (RBCs) of rats treated with (14C)MCT. To determine whether this RBC sequestration might be important in the transport of reactive MCT metabolites, they compared the effect of inclusion of RBCs in the perfusion buffer on the extent of covalent binding of (14C)MCT to rat lungs in tandem liver-lung preparations. The potential effect of RBCs in stabilizing reactive intermediates was evaluated by preperfusion of isolated liver preparations with (14C)MCT with and without RBCs, separation and washing of the RBC fraction, and subsequent (90 min later) perfusion of washed RBCs or buffer alone in isolated perfused lungs. Covalent binding to lung tissues was determined by exhaustive methanol/chloroform extractions of unbound label from homogenized lung tissue followed by scintillation counting of residual 14C. Covalent binding was expressed as picomole MCT molecular weight equivalents/mg protein. Comparison of the relative capability of these isolated organ preparations for conversion of MCT to polar metabolites was done by extraction and HPLC analysis of perfusate at the end of the experiment. Isolated livers converted 65-85% of MCT to polar metabolites compared with less than 5% conversion in the isolated lungs. Inclusion of RBCs in the buffer of tandem lung liver preparations perfused with 400 microM (14C)MCT increased the covalent binding to the lung from 97 {plus minus} 25 (buffer alone) to 182 {plus minus} 36 (buffer + RBC) pmol/mg protein.

Red blood cells augment transport of reactive metabolites of monocrotaline from liver to lung in isolated and tandem liver and lung preparations

International Nuclear Information System (INIS)

Pan, L.C.; Lame, M.W.; Morin, D.; Wilson, D.W.; Segall, H.J.

1991-01-01

Monocrotaline (MCT) is a pyrrolizidine alkaloid that causes pulmonary hypertension in rats by mechanisms which remain largely unknown. MCT is thought to be activated in the liver to a reactive intermediate that is transported to the lung where it causes endothelial injury. The authors previous pharmacokinetic work demonstrated significant sequestration of radioactivity in red blood cells (RBCs) of rats treated with [14C]MCT. To determine whether this RBC sequestration might be important in the transport of reactive MCT metabolites, they compared the effect of inclusion of RBCs in the perfusion buffer on the extent of covalent binding of [14C]MCT to rat lungs in tandem liver-lung preparations. The potential effect of RBCs in stabilizing reactive intermediates was evaluated by preperfusion of isolated liver preparations with [14C]MCT with and without RBCs, separation and washing of the RBC fraction, and subsequent (90 min later) perfusion of washed RBCs or buffer alone in isolated perfused lungs. Covalent binding to lung tissues was determined by exhaustive methanol/chloroform extractions of unbound label from homogenized lung tissue followed by scintillation counting of residual 14C. Covalent binding was expressed as picomole MCT molecular weight equivalents/mg protein. Comparison of the relative capability of these isolated organ preparations for conversion of MCT to polar metabolites was done by extraction and HPLC analysis of perfusate at the end of the experiment. Isolated livers converted 65-85% of MCT to polar metabolites compared with less than 5% conversion in the isolated lungs. Inclusion of RBCs in the buffer of tandem lung liver preparations perfused with 400 microM [14C]MCT increased the covalent binding to the lung from 97 ± 25 (buffer alone) to 182 ± 36 (buffer + RBC) pmol/mg protein

Study of therapeutic and histopathologic effects of corn silk\\'s aqueous and metanolic extract against dosage induced by MDMA in isolated rat liver perfusion system

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Mohammad Karami

2014-04-01

Full Text Available Background: Corn silk is obtained from the plant Zea mays L. A traditional herbal medicine is in China. This has been used in many parts of the world to treat edema, kidney infections, gout, kidney stones, kidney diseases and prostate. Reports of the antioxidant effects of this material are available. Although little scientific resources are available to confirm its efficacy. In this study we tried to find out the antioxidant effect and preventing of hepatotoxicity effect of Corn silk with IRLP Isolated Rat Liver Perfusion system. Material and Methods: The aqueous and methanol extracts of dried Corn silk doses (10, 20, 40, 50 and 100 mg/kg was used. Albino Rats weighing 220-180 g were examined after anesthesia by diethyl ether, the abdominal cavity of the animal T-shaped pattern excision in the abdomen and around is opened.Then portal vein connected to the perfusion flow by using small scalp Vienna (No. 23 into the portal vein. After reaching perfusion flow rate to 20 ml per minute, extracts and fraction with above doses were added to perfusion buffer. Fluid outflows from the inferior vena cava, were collected for measurement of glutathione. One sample of the liver was removed for glutathione measurement and one sample was maintained in 10% formalin for histopathological examination. Differences between group means were estimated using oneway ANOVA followed by Duncan’s multiple range test. Results: The results showed that reduced glutathione level increased significantly by aqueous and methanol extract in comparison with controls. Pathology results confirmed that by increasing dose of extracts, severity of tissue damage (hemorrhage, fibrosis, and necrosis is reduced. In samples taken at intervals of 120 minutes, changes in the glutathione of case groups showed significant difference in comparison with the control group (p<0.01. Conclusion: Findings indicated that aqueous and methanolic extracts of corn fiber, reduced hepatic damages of MDMA

Competing pathways in drug metabolism. I. Effect of input concentration on the conjugation of gentisamide in the once-through in situ perfused rat liver preparation

International Nuclear Information System (INIS)

Morris, M.E.; Yuen, V.; Tang, B.K.; Pang, K.S.

1988-01-01

Sulfation and glucuronidation are two parallel pathways for the metabolism of phenolic substrates. Gentisamide (GAM) was used as a model compound to examine the effects of parallel competing pathways on drug disappearance and metabolite formation in the once-through perfused rat liver preparation. GAM was found to form one glucuronide (GAM-5G) and two sulfate (GAM-2S and GAM-5S) conjugates. These GAM conjugates were biosynthesized in recirculating rat liver preparations, and were isolated by preparative high-performance liquid chromatography. Specific incorporation of 35S-sodium sulfate and [14C]glucose into GAM sulfate and glucuronide conjugates revealed corresponding elution patterns as labeled GAM metabolites. Their identities were characterized by enzymatic and acid hydrolyses and by NMR spectroscopy. Gentisamide-5-sulfate (GAM-5S) and gentisamide-5-glucuronide (GAM-5G) are major metabolites, and gentisamide-2-sulfate (GAM-2S) is a minor metabolite. Single-pass rat liver perfusions were used to examine the effect of stepwise increases/decreases of input GAM concentration (CIn) on the extraction ratio (E) of GAM and formation of metabolites. The E of GAM remained constant (about 0.89) at input concentrations from 0.9 to 120 microM and decreased at CIn greater than 120 microM. Metabolite patterns, however, changed with GAM CIn, even when E was constant at CIn up to 120 microM. GAM-5S was present as the major metabolite of GAM at all GAM CInS in most liver preparations but the proportions of GAM-5S and GAM-2S decreased at increasing CIn; the proportion of GAM-5G, a minor metabolite at low CIn, increased with increasing CIn. Biliary excretion rates at steady state accounted for 5.3 +/- 2.7% (mean +/- S.D.) of the input rate: GAM-5G was the predominant metabolite found

The research on the influences of hyperthermal perfusion chemotherapy combined with immunologic therapy on the immunologic function and levels of circulating tumor cells of the advanced colorectal cancer patients with liver metastasis.

Science.gov (United States)

Sun, J-J; Fan, G-L; Wang, X-G; Xu, K

2017-07-01

To investigated the influence of hyperthermal perfusion chemotherapy combined with immunologic therapy on the immunologic function and levels of circulating tumor cells of the advanced colorectal cancer patients with liver metastasis. We enrolled 98 advanced colorectal cancer patients with liver metastasis that were admitted to this hospital for treatment and were randomly divided into two groups, the observation group (n = 49) and the control group (n = 49). We administered systemic vein chemotherapy for patients in the control group, and hyperthermal perfusion chemotherapy for the patients in the observation group in order to compare the subgroup levels of T lymphocytes, NK cells and immunoglobulin (IgG, IgA, and IgM) in the immune system of patients in both groups. We also assayed the circulating tumor cells (CTC) in the peripheral blood of patients in both groups using the cell search method, and compared the efficacy using response evaluation criteria in solid tumors and the survival rates of patients in both groups using the Kaplan-Meier method. After two treatment courses, the levels of CD3+, CD4+ and CD4+/CD8+ of the patients in the observation group were significantly higher than those of the control group, but the levels of CD8+ of patients in the observation group was lower than that in the control group (pfunctions of patients for the indirect anti-tumor effect, a significant decrease in CTC of patients, and a higher long-term survival rate have been achieved in the treatment with hyperthermal perfusion chemotherapy combined with immunologic therapy for the advanced colorectal cancer patients with liver metastasis. Thus, it can serve as the preferable drug for the treatment of advanced colorectal cancer with liver metastasis.

Biliary excretion of ouabain in isolated perfused rat liver after treatment with microsomal enzyme inducers

International Nuclear Information System (INIS)

Nevasaari, K.; Alakare, B.; Kaerki, N.T.

1976-01-01

The effect of pretreatment with spironolactone, phenobarbital and 3,4-benzpyrene on biliary excretion of ouabain was studied in isolated perfused rat liver system after a single dose of 3 H-ouabain. Spironolactone pretreatment (100 mg/kg intraperitoneally for 4 days) changed the time course of the excretion, thus accelerating the transport of ouabain into the bile. Phenobarbital pretreatment (75 mg/kg intraperitoneally for 4 days) enhanced bile flow and increased biliary excretion of ouabain only after 15 min. At longer time periods the increase in bile flow diluted the bile level of ouabain there being no difference in the amounts excreted into the bile between the treated and untreated groups. 3,4-benzpyrene pretreatment (20 mg/kg intraperitoneally for 4 days) was without efffect on biliary excretion of ouabain. The results suggest that spironolactone differs from phenobarbital in its enhancing effect on biliary excretion of ouabain, possibly through a specific effect on an unknown hepatic transport mechanism. (author)

Hepatic perfusion disorders: a pictorial review of CT and MR imaging

International Nuclear Information System (INIS)

Yim, Nam Yeol; Jeong, Yong Yeon; Shin, Sang Soo; Song, Sang Gook; Lim, Hyo Soon; Heo, Suk Hee; Chang, Nam Kyu; Yoon, Woong; Kang, Heoung Keun; Lan, Shen Yu

2005-01-01

The liver has a unique dual blood supply through the portal vein and the hepatic artery. There are several communications between these two vessels under various conditions such as in hepatic tumors, trauma and liver cirrhosis, vascular compromise, among others. When vascular compromise occurs, this dual blood supply system can cause changes in the volume of blood flow in individual vessels or even in the direction of blood flow. With rapid image acquisition and increased resolution available in multislice CT and MR imaging, hepatic perfusion disorders are now more frequently encountered than in the past. Familiarity with imaging findings of these perfusion disorders will be helpful in characterizing focal hepatic lesions and will also help to avoid false positive diagnoses

Hepatic perfusion disorders: a pictorial review of CT and MR imaging

Energy Technology Data Exchange (ETDEWEB)

Yim, Nam Yeol; Jeong, Yong Yeon; Shin, Sang Soo; Song, Sang Gook; Lim, Hyo Soon; Heo, Suk Hee; Chang, Nam Kyu; Yoon, Woong; Kang, Heoung Keun [Chonnam National University, Gwangju (Korea, Republic of); Lan, Shen Yu [Yan Bian Cancer Hospital, Peijing (China)

2005-09-15

The liver has a unique dual blood supply through the portal vein and the hepatic artery. There are several communications between these two vessels under various conditions such as in hepatic tumors, trauma and liver cirrhosis, vascular compromise, among others. When vascular compromise occurs, this dual blood supply system can cause changes in the volume of blood flow in individual vessels or even in the direction of blood flow. With rapid image acquisition and increased resolution available in multislice CT and MR imaging, hepatic perfusion disorders are now more frequently encountered than in the past. Familiarity with imaging findings of these perfusion disorders will be helpful in characterizing focal hepatic lesions and will also help to avoid false positive diagnoses.

Liver slices in in vitro pharmacotoxicology with special reference to the use of human liver tissue

NARCIS (Netherlands)

Olinga, Peter; Meijer, D.K F; Slooff, M.JH; Groothuis, Geny

In the early years of research in in vitro pharmacotoxicology liver slices have been used. After a decline in the application of slices in favour of the use of isolated hepatocytes and the isolated perfused liver preparation, the development of the Krumdieck slicer in the 1980s led to a 'comeback'

Hepatic Arterial Perfusion Scintigraphy with '99mTc-Macroaggregated Albumin in Hepatocellular Carcinoma

International Nuclear Information System (INIS)

Kim, Gang Deuk; Sohn, Kwang Joon; Min, Kyung Yoon; Kwon, Young Mi; Kim, Chang Guhn; Noh, Byung Suk; Won, Jong Jin

1994-01-01

Hepatic arterial perfusion scintigraphy with '9 9m Tc macroggregated albumin (HAPS) study was carried out in 16 patients with hepatocellular carcinoma (HCC) and in six patients without liver tumor to evaluate HAPS findings of hepatocellular carcinoma and use fullness of HAPS. HAPS with planar and SPECT study were performed in 22 patients after conventional hepatic or celiac arteriography. For HAPS study, 4 5 mCi of MAA mixed with 2 ml of saline was injected into proper hepatic artery or its distal branches at the rate of approximately 1 ml/sec. We analysed 21 HCCs over 2 cm in diameter(average diameter: 6.4 cm) and 17 of 21 HCCs were over 4 cm in diameter. CT, sonography and angiography were performed within two week in all 16 patients and liver scan was performed in 12 patients. Three different pattern of tumor perfusion were observed in 16 patients with HCC. 1) diffuse increased perfusion in 16 of 21(76%) 2) increased peripheral perfusion in 4 of 21(19%) 3) diffuse decreased perfusion in 1 of 21 (5%) Arteriovenous shunt indicated by lung uptake of MAA were observed in 9 of 16 (56% ). In contrast, angiography demonstrates arteriovenous shunt in 2 of 16 (13%). There was no accumulation of radioactivity on RRC blood pool scan in all six patients with HCC examined. HAPS is useful study in evaluation of perfusion pattern or vascularity of HCC and in detection of arteriovenous shunt.

Unsatisfactory hepatic perfusion after placement of the infusaid pump: Angiographic correlation

International Nuclear Information System (INIS)

Andrews, J.C.; Williams, D.M.; Cho, K.J.; Knol, J.A.; Wahl, R.L.; Ensminger, W.D.

1988-01-01

Complete perfusion limited to the liver is essential to the success of regional chemotherapy for hepatic malignancy. Thirty-three patients with unsatisfactory hepatic artery perfusion scintigrams after surgical placement of a pump and catheter system were evaluated with selective angiography (31 cases) or digital subtraction angiography (DSA) via the pump side port (six cases). The cause of the perfusion defect was hepatic artery thrombosis (14 cases), extrahepatic flow through collaterals (13 cases), misplaced catheter (three cases), short proper hepatic artery without adequate length for mixing (two cases), and undefined (one case). DSA findings were diagnostic in only two cases. Angiographic findings directed attempted correction in 22 of 33 cases

The prediction of radiofrequency ablation zone volume using vascular indices of 3-dimensional volumetric colour Doppler ultrasound in an in vitro blood-perfused bovine liver model

Science.gov (United States)

Lanctot, Anthony C; McCarter, Martin D; Roberts, Katherine M; Glueck, Deborah H; Dodd, Gerald D

2017-01-01

Objective: To determine the most reliable predictor of radiofrequency (RF) ablation zone volume among three-dimensional (3D) volumetric colour Doppler vascular indices in an in vitro blood-perfused bovine liver model. Methods: 3D colour Doppler volume data of the local hepatic parenchyma were acquired from 37 areas of 13 bovine livers connected to an in vitro oxygenated blood perfusion system. Doppler vascular indices of vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were obtained from the volume data using 3D volume analysis software. 37 RF ablations were performed at the same locations where the ultrasound data were obtained from. The relationship of these vascular indices and the ablation zone volumes measured from gross specimens were analyzed using a general linear mixed model fit with random effect for liver and backward stepwise regression analysis. Results: FI was significantly associated with ablation zone volumes measured on gross specimens (p = 0.0047), but explained little of the variance (Rβ2 = 0.21). Ablation zone volume decreased by 0.23 cm3 (95% confidence interval: −0.38, −0.08) for every 1 increase in FI. Neither VI nor VFI was significantly associated with ablation zone volumes (p > 0.05). Conclusion: Although FI was associated with ablation zone volumes, it could not sufficiently explain their variability, limiting its clinical applicability. VI, FI and VFI are not clinically useful in the prediction of RF ablation zone volume in the liver. Advances in knowledge: Despite a significant association of FI with ablation zone volumes, VI, FI and VFI cannot be used for their prediction. Different Doppler vascular indices need to be investigated for clinical use. PMID:27925468

TH-A-9A-04: Incorporating Liver Functionality in Radiation Therapy Treatment Planning

International Nuclear Information System (INIS)

Wu, V; Epelman, M; Feng, M; Cao, Y; Wang, H; Romeijn, E; Matuszak, M

2014-01-01

Purpose: Liver SBRT patients have both variable pretreatment liver function (e.g., due to degree of cirrhosis and/or prior treatments) and sensitivity to radiation, leading to high variability in potential liver toxicity with similar doses. This work aims to explicitly incorporate liver perfusion into treatment planning to redistribute dose to preserve well-functioning areas without compromising target coverage. Methods: Voxel-based liver perfusion, a measure of functionality, was computed from dynamic contrast-enhanced MRI. Two optimization models with different cost functions subject to the same dose constraints (e.g., minimum target EUD and maximum critical structure EUDs) were compared. The cost functions minimized were EUD (standard model) and functionality-weighted EUD (functional model) to the liver. The resulting treatment plans delivering the same target EUD were compared with respect to their DVHs, their dose wash difference, the average dose delivered to voxels of a particular perfusion level, and change in number of high-/low-functioning voxels receiving a particular dose. Two-dimensional synthetic and three-dimensional clinical examples were studied. Results: The DVHs of all structures of plans from each model were comparable. In contrast, in plans obtained with the functional model, the average dose delivered to high-/low-functioning voxels was lower/higher than in plans obtained with its standard counterpart. The number of high-/low-functioning voxels receiving high/low dose was lower in the plans that considered perfusion in the cost function than in the plans that did not. Redistribution of dose can be observed in the dose wash differences. Conclusion: Liver perfusion can be used during treatment planning potentially to minimize the risk of toxicity during liver SBRT, resulting in better global liver function. The functional model redistributes dose in the standard model from higher to lower functioning voxels, while achieving the same target EUD

The effect of pregnancy and estradiol-17 beta treatment on the biliary transport maximum of dibromosulfophthalein, and the glucuronide conjugates of 5-phenyl-5-p-hydroxyphenyl[14C]hydantoin and [14C]morphine in the isolated perfused rat liver

International Nuclear Information System (INIS)

Auansakul, A.C.; Vore, M.

1982-01-01

The biliary transport maximum (Tm) of three organic axions was determined in the isolated perfused livers of untreated female (control), estradiol-17 beta (E2)-treated female (1 mg/kg/day, s.c. for 14 days), and pregnant (19-21 days of gestation) rats. Dibromosulfophthalein (DBSP), 5-phenyl-5-p-hydroxyphenyl[ 14 C]hydantoin (HPPH) and [ 14 C]morphine were infused continuously into the perfusate for a total dose of 41.2, 18, or 40.5 mumol, respectively. The concentration of [ 14 C]HPPH and [ 14 C]morphine declined in the perfusate, whereas the concentrations of [ 14 C]HPPH glucuronide and [ 14 C]morphine glucuronide increased during the 90-min experiment, indicating that the rate of formation of the glucuronide exceeded its rate of excretion in bile. E2 treatment decreased the Tm (nmol/min/g liver) for [ 14 C]HPPH glucuronide and [ 14 C]morphine glucuronide but not for DBSP, whereas pregnancy decreased the Tm for all three organic anions. Pregnancy, and to a lesser extent E2 treatment, increased liver weight. When expressed per whole liver, the Tm was not altered by pregnancy for any of three organic anions. E2 treatment increased the Tm for DBSP, had no effect on the Tm for HPPH glucuronide and decreased the Tm for [ 14 C]morphine glucuronide. These data suggest the presence of multiple carriers for organic anions which are differentially affected by estrogen treatment and pregnancy

CT perfusion imaging of the liver and the spleen in patients with cirrhosis: Is there a correlation between perfusion and portal venous hypertension?

Science.gov (United States)

Talakić, Emina; Schaffellner, Silvia; Kniepeiss, Daniela; Mueller, Helmut; Stauber, Rudolf; Quehenberger, Franz; Schoellnast, Helmut

2017-10-01

To correlate hepatic and splenic CT perfusion parameters with hepatic venous pressure gradient (HVPG) measurements in patients with cirrhosis. Twenty-one patients with cirrhosis (males, 17; females, 4; mean ± SD age, 57 ± 7 years) underwent hepatic and splenic perfusion CT on a 320-detector row volume scanner as well as invasive measurement of HVPG. Different CT perfusion algorithms (maximum slope analysis and Patlak plot) were used to measure hepatic arterial flow (HAF), portal venous flow (PVF), hepatic perfusion index (HPI), splenic arterial flow (SAF), splenic blood volume (SBV) and splenic clearance (SCL). Hepatic and splenic perfusion parameters were correlated with HVPG, and sensitivity and specificity for detection of severe portal hypertension (≥12 mmHg) were calculated. The Spearman correlation coefficient was -0.53 (p portal hypertension. • SAF and SCL are statistically significantly correlated with HVPG • SCL showed stronger correlation with HVPG than SAF • 125 ml/min/100 ml SCL-cut-off yielded 94 % sensitivity, 100 % specificity for severe PH • HAF, PVF and HPI showed no statistically significant correlation with HVPG.

Hepatic clearance of 6 polyaromatic aromatic hydrocarbons by isolated trout livers: Prediction from in vitro clearance by liver S9 fractions

Science.gov (United States)

An isolated perfused trout liver preparation was used to evaluate in vitro-to-in vivo metabolism extrapolation procedures for fish. Hepatic clearance (CLH) studies were conducted with six polyaromatic hydrocarbons (PAH) using an experimental design wherein each liver acted as it...

Boron biodistribution study in colorectal liver metastases patients in Argentina

International Nuclear Information System (INIS)

Cardoso, J.; Nievas, S.; Pereira, M.; Schwint, A.; Trivillin, V.; Pozzi, E.; Heber, E.; Monti Hughes, A.; Sanchez, P.; Bumaschny, E.; Itoiz, M.; Liberman, S.

2009-01-01

Ex-situ BNCT for multifocal unresectable liver metastases employing whole or partial autograft techniques requires knowledge of boron concentrations in healthy liver and metastases following perfusion and immersion in Wisconsin solution (W), the procedure employed for organ preservation during ex-situ irradiation. Measurements of boron concentration in blood, liver and metastases following an intravenous infusion of BPA-F in five colorectal liver metastases patients scheduled for surgery were performed. Tissue samples were evaluated for boron content pre and post perfusion and immersion in W. Complementary histological studies were performed. The data showed a dose-dependent BPA uptake in liver, a boron concentration ratio liver/blood close to 1 and a wide spread in the metastases/liver concentration ratios in the range 0.8-3.6, partially attributable to histological variations between samples. Based on the boron concentrations and dose considerations (liver≤ 15 Gy-Eq and tumor≥40 Gy-Eq) at the RA-3 thermal neutron facility (mean flux of about (6±1)x10 9 n cm -2 s -1 ), ex-situ treatment of liver metastases at RA-3 would be feasible.

Tc-99m macroaggregate albumin perfusion studies in the therapeutically embolized liver

International Nuclear Information System (INIS)

Hall, J.T.; Kim, E.E.; Charnsangavej, C.; Haynie, T.P.; Wallace, S.

1988-01-01

This paper discusses the authors' study of 15 patients who underwent 21 hepatic arterial chemoembolizations and hepatic arterial chemotherapy infusions. The arteriograms and the hepatic perfusion studies using Tc-99m macroaggregates of human serum albumin (MAA) particles were reviewed and correlated. Early perfusion studies (within 4 hours of embolization) often revealed flow reversal or MAA reflux into an undesirable location. Scans obtained at 24 hours revealed restoration of flow to the embolized lobe, confirming the proper position of the catheter for hepatic arterial chemotherapy infusion

Adipose derived mesenchymal stem cells transplantation via portal vein improves microcirculation and ameliorates liver fibrosis induced by CCl4 in rats

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Wang Yu

2012-06-01

Full Text Available Abstract Introduction Adipose derived mesenchymal stem cells (ADMSCs, carrying the similar characteristics to bone marrow mesenchymal stem cells, only much more abundant and easier to obtain, may be a promising treatment for liver fibrosis. We aim to investigate the therapeutic potential of ADMSCs transplantation in liver fibrosis caused by carbon tetrachloride (CCl4 in rats as well as its underlying mechanism, and to further explore the appropriate infusion pathway. Methods ADMSCs were isolated, cultured and identified. Placebo and ADMSCs were transplanted via portal vein and tail vein respectively into carbon tetrachloride (CCl4-induced liver fibrosis rats. Computed tomography (CT perfusion scan and microvessel counts were performed to measure the alteration of liver microcirculation after therapy. Liver function tests and histological findings were estimated. Results CT perfusion scan shown significant decrease of hepatic arterial perfusion index, significant increased portal vein perfusion, total liver perfusion in rats receiving ADMSCs from portal vein, and Factor VIII (FVIII immunohistochemical staining shown significant decrease of microvessels in rats receiving ADMSCs from portal vein, indicating microcirculation improvement in portal vein group. Vascular endothelial growth Factor (VEGF was significantly up-regulated in fibrosis models, and decreased after ADMSCs intraportal transplantation. A significant improvement of liver functional test and histological findings in portal vein group were observed. No significance was found in rats receiving ADMSCs from tail vein. Conclusions ADMSCs have a therapeutic effect against CCl4-mediated liver fibrosis. ADMSCs may benefit the fibrotic liver through alteration of microcirculation, evidenced by CT perfusion scan and down-regulation of VEGF. Intraportal transplantation is a better pathway than tail vein transplantation.

Does Enhancement or Perfusion on Preprocedure CT Predict Outcomes After Embolization of Hepatocellular Carcinoma?

Science.gov (United States)

Borgheresi, Alessandra; Gonzalez-Aguirre, Adrian; Brown, Karen T; Getrajdman, George I; Erinjeri, Joseph P; Covey, Anne; Yarmohammadi, Hooman; Ziv, Etay; Sofocleous, Constantinos T; Boas, Franz Edward

2018-03-27

The objective of this study was to evaluate whether quantitative enhancement or perfusion measurements on preprocedure triphasic computed tomography (CT) can be used to predict response or overall survival after embolization of hepatocellular carcinoma. The institutional review board approved this retrospective review of 63 patients with hepatocellular carcinoma treated with particle embolization between March 2009 and December 2014. Quantitative enhancement and perfusion measurements were performed on the target tumor and the background liver on the triphasic CT performed before treatment. Microvascular invasion (MVI) and degree of differentiation were determined from a core biopsy specimen. Quantitative enhancement and perfusion values were then correlated with pathology (two-tailed t test), response to embolization on modified Response Evaluation Criteria In Solid Tumors (two-tailed t test), and overall survival after embolization (Cox proportional hazards model). Arterial enhancement did not predict immediate response or overall survival after embolization. The degree of differentiation or presence of MVI also did not predict immediate response or overall survival after embolization. However, high hepatic artery coefficient or low portal vein coefficient, both in the tumor (P = .011 and P = .004) and in the background liver (P = .015 and P = .009), were associated with worse survival. Hepatic artery coefficient, both in the tumor (P = .025) and in the background liver (P = .013), were independent predictors of survival in a multivariate model including the Child-Pugh score and the BCLC stage. Tumor and liver perfusion parameters estimated from preprocedure triphasic CT were predictive of survival after embolization. Arterial-phase enhancement and histology (degree of differentiation or MVI) did not predict immediate response or overall survival after particle embolization. Copyright © 2018 The Association of University Radiologists

Rat Liver Enzyme Release Depends on Blood Flow-Bearing Physical Forces Acting in Endothelium Glycocalyx rather than on Liver Damage

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Julieta A. Díaz-Juárez

2017-01-01

Full Text Available We have found selective elevation of serum enzyme activities in rats subjected to partial hepatectomy (PH, apparently controlled by hemodynamic flow-bearing physical forces. Here, we assess the involvement of stretch-sensitive calcium channels and calcium mobilization in isolated livers, after chemical modifications of the endothelial glycocalyx and changing perfusion directionality. Inhibiting in vivo protein synthesis, we found that liver enzyme release is influenced by de novo synthesis of endothelial glycocalyx components, and released enzymes are confined into a liver “pool.” Moreover, liver enzyme release depended on extracellular calcium entry possibly mediated by stretch-sensitive calcium channels, and this endothelial-mediated mechanotransduction in liver enzyme release was also evidenced by modifying the glycocalyx carbohydrate components, directionality of perfusing flow rate, and the participation of nitric oxide (NO and malondialdehyde (MDA, leading to modifications in the intracellular distribution of these enzymes mainly as nuclear enrichment of “mitochondrial” enzymes. In conclusion, the flow-induced shear stress may provide fine-tuned control of released hepatic enzymes through mediation by the endothelium glycocalyx, which provides evidence of a biological role of the enzyme release rather to be merely a biomarker for evaluating hepatotoxicity and liver damage, actually positively influencing progression of liver regeneration in mammals.

Haemoadsorption reduces the inflammatory response and improves blood flow during ex vivo renal perfusion in an experimental model.

Science.gov (United States)

Hosgood, Sarah A; Moore, Tom; Kleverlaan, Theresa; Adams, Tom; Nicholson, Michael L

2017-10-25

Ex-vivo normothermic perfusion strategies are a promising new instrument in organ transplantation. The perfusion conditions are designed to be protective however the artificial environment can induce a local inflammatory response. The aim of this study was to determine the effect of incorporating a Cytosorb adsorber into an isolated kidney perfusion system. Porcine kidneys were subjected to 22 h of cold ischaemia then reperfused for 6 h on an ex vivo reperfusion circuit. Pairs of kidneys were randomised to either control (n = 5) or reperfusion with a Cytosorb adsorber (n = 5) integrated into the circuit. Tissue, blood and urine samples were taken for the measurement of inflammation and renal function. Baseline levels of cytokines (IL-6, TNFα, IL-8, IL-10, IL-1β, IL-1α) were similar between groups. Levels of IL-6 and IL-8 in the perfusate significantly increased during reperfusion in the control group but not in the Cytosorb group (P = 0.023, 0.049). Levels of the other cytokines were numerically lower in the Cytosorb group; however, this did not reach statistical significance. The mean renal blood flow (RBF) was significantly higher in the Cytosorb group (162 ± 53 vs. 120 ± 35 mL/min/100 g; P = 0.022). Perfusate levels of prostaglandin E2 were significantly lower in the Cytosorb group (642 ± 762 vs. 3258 ± 980 pg/mL; P = 0.0001). Levels of prostacyclin were significantly lower in the Cytosorb group at 1, 3 and 6 h of reperfusion (P = 0.008, 0.003, 0.0002). Levels of thromboxane were also significantly lower in the Cytosorb group throughout reperfusion (P = 0.005). Haemoadsorption had no effect on creatinine clearance (P = 0.109). Haemoadsorption can reduce the inflammatory response and improve renal blood flow during perfusion. Nonetheless, in this model haemoadsorption had no influence on renal function and this may relate to the broad-spectrum action of the Cytosorb adsorber that also removes potentially important anti

Extracorporeal perfusion for the treatment of acute liver failure

NARCIS (Netherlands)

H.B.A.C. Stockmann; C.A. Hiemstra; R.L. Marquet (Richard); J.N.M. IJzermans (Jan)

2000-01-01

textabstractOBJECTIVE AND SUMMARY BACKGROUND DATA: Because of the shortage of available donor organs, death rates from liver failure remain high. Therefore, several temporary liver-assisting therapies have been developed. This article reviews various approaches to

Adrenergic Metabolic and Hemodynamic Effects of Octopamine in the Liver

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Adelar Bracht

2013-11-01

Full Text Available The fruit extracts of Citrus aurantium (bitter orange are traditionally used as weight-loss products and as appetite suppressants. A component of these extracts is octopamine, which is an adrenergic agent. Weight-loss and adrenergic actions are always related to metabolic changes and this work was designed to investigate a possible action of octopamine on liver metabolism. The isolated perfused rat liver was used to measure catabolic and anabolic pathways and hemodynamics. Octopamine increased glycogenolysis, glycolysis, oxygen uptake, gluconeogenesis and the portal perfusion pressure. Octopamine also accelerated the oxidation of exogenous fatty acids (octanoate and oleate, as revealed by the increase in 14CO2 production derived from 14C labeled precursors. The changes in glycogenolysis, oxygen uptake and perfusion pressure were almost completely abolished by α1-adrenergic antagonists. The same changes were partly sensitive to the β-adrenergic antagonist propranolol. It can be concluded that octopamine accelerates both catabolic and anabolic processes in the liver via adrenergic stimulation. Acceleration of oxygen uptake under substrate-free perfusion conditions also means acceleration of the oxidation of endogenous fatty acids, which are derived from lipolysis. All these effects are compatible with an overall stimulating effect of octopamine on metabolism, which is compatible with its reported weight-loss effects in experimental animals.

Use of contrast agents for liver MRI

International Nuclear Information System (INIS)

Ward, Janice

2007-01-01

Contrast-enhanced MRI is recognised as one of the most accurate imaging methods for investigating diseases of the liver. Uniquely several different types of contrast agents are available for liver MRI. They can be divided into non-specific extracellular fluid space (ECF), hepatocyte specific and reticulo-endothelial system (RES) specific agents. They are used to improve the detection of focal liver lesions by increasing normal-abnormal tissue contrast and to assist in lesion characterisation by demonstrating tissue perfusion and cellular function. ECF-gadolinium (Gd) chelates have been widely used in abdominal MRI for many years. They provide valuable information regarding the vascularisation and perfusion characteristics of lesions and assist in lesion detection, particularly of hypervascular lesions. The hepatocyte and RES-specific agents further improve lesion detection, provide important functional information and allow the distinction between hepatocellular and non-hepatocellular tumours. This article describes the different MR contrast agents and discusses their current status for diagnosing focal liver lesions. The importance of optimised technique and appropriate selection of contrast agent is emphasised

Insulin resistance and delayed clearance of peptide hormones in cirrhotic rat liver

International Nuclear Information System (INIS)

Shankar, T.P.; Drake, S.; Solomon, S.S.

1987-01-01

Clearance of porcine insulin, glucagon, and human growth hormone was measured in intact perfused cirrhotic and normal rat livers. Binding and degradation of 125 I-insulin by hepatocytes isolated from cirrhotic and normal livers were also studied. The half-lives (t/sub 1/2/) of immunoreactive insulin and glucagon were 14.0 +/- 3.1 and 9.6 +/- 2.1 min in normal livers and 26.0 +/- 6.1 and 25.0 +/- 7.1 min in cirrhotic livers. Insulin binding and degradation by hepatocytes from control and cirrhotic livers showed no significant differences. Intraportal insulin infusion in perfusion studies suppressed glucagon-stimulated increases in glucose output from control livers but failed to suppress glucose production by cirrhotic livers, suggesting the presence of hepatic insulin resistance in cirrhosis. Impaired clearance of insulin and glucagon by the intact cirrhotic liver and normal binding and degradation of insulin by isolated hepatocytes suggest that factors such as intrahepatic fibrosis and shunting and postbinding defects may be responsible for the impaired hormone clearance and hepatic insulin resistance

The impact of an hematocrit of 20% during normothermic cardiopulmonary bypass for elective low risk coronary artery bypass graft surgery on oxygen delivery and clinical outcome – a randomized controlled study [ISRCTN35655335

Science.gov (United States)

von Heymann, Christian; Sander, Michael; Foer, Achim; Heinemann, Anja; Spiess, Bruce; Braun, Jan; Krämer, Michael; Grosse, Joachim; Dohmen, Pascal; Dushe, Simon; Halle, Jürgen; Konertz, Wolfgang F; Wernecke, Klaus-Dieter; Spies, Claudia

2006-01-01

Introduction Cardiopulmonary bypass (CPB) induces hemodilutional anemia, which frequently requires the transfusion of blood products. The objective of this study was to evaluate oxygen delivery and consumption and clinical outcome in low risk patients who were allocated to an hematocrit (Hct) of 20% versus 25% during normothermic CPB for elective coronary artery bypass graft (CABG) surgery. Methods This study was a prospective, randomized and controlled trial. Patients were subjected to normothermic CPB (35 to 36°C) and were observed until discharge from the intensive care unit (ICU). Outcome measures were calculated whole body oxygen delivery, oxygen consumption and clinical outcome. A nonparametric multivariate analysis of variance for repeated measurements and small sample sizes was performed. Results In a total of 54 patients (25% Hct, n = 28; 20% Hct, n = 26), calculated oxygen delivery (p = 0.11), oxygen consumption (p = 0.06) and blood lactate (p = 0.60) were not significantly different between groups. Clinical outcomes were not different between groups. Conclusion These data indicate that an Hct of 20% during normothermic CPB maintained calculated whole body oxygen delivery above a critical level after elective CABG surgery in low risk patients. The question of whether a transfusion trigger in excess of 20% Hct during normothermic CPB is still supported requires a larger prospective and randomized trial. PMID:16606474

Noninvasive, near infrared spectroscopic-measured muscle pH and PO2 indicate tissue perfusion for cardiac surgical patients undergoing cardiopulmonary bypass

Science.gov (United States)

Soller, Babs R.; Idwasi, Patrick O.; Balaguer, Jorge; Levin, Steven; Simsir, Sinan A.; Vander Salm, Thomas J.; Collette, Helen; Heard, Stephen O.

2003-01-01

OBJECTIVE: To determine whether near infrared spectroscopic measurement of tissue pH and Po2 has sufficient accuracy to assess variation in tissue perfusion resulting from changes in blood pressure and metabolic demand during cardiopulmonary bypass. DESIGN: Prospective clinical study. SETTING: Academic medical center. SUBJECTS: Eighteen elective cardiac surgical patients. INTERVENTION: Cardiac surgery under cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS: A near infrared spectroscopic fiber optic probe was placed over the hypothenar eminence. Reference Po2 and pH sensors were inserted in the abductor digiti minimi (V). Data were collected every 30 secs during surgery and for 6 hrs following cardiopulmonary bypass. Calibration equations developed from one third of the data were used with the remaining data to investigate sensitivity of the near infrared spectroscopic measurement to physiologic changes resulting from cardiopulmonary bypass. Near infrared spectroscopic and reference pH and Po2 measurements were compared for each subject using standard error of prediction. Near infrared spectroscopic pH and Po2 at baseline were compared with values during cardiopulmonary bypass just before rewarming commenced (hypotensive, hypothermic), after rewarming (hypotensive, normothermic) just before discontinuation of cardiopulmonary bypass, and at 6 hrs following cardiopulmonary bypass (normotensive, normothermic) using mixed-model analysis of variance. Near infrared spectroscopic pH and Po2 were well correlated with the invasive measurement of pH (R2 =.84) and Po2 (R 2 =.66) with an average standard error of prediction of 0.022 +/- 0.008 pH units and 6 +/- 3 mm Hg, respectively. The average difference between the invasive and near infrared spectroscopic measurement was near zero for both the pH and Po2 measurements. Near infrared spectroscopic Po2 significantly decreased 50% on initiation of cardiopulmonary bypass and remained depressed throughout the bypass and

Effects of ethanol and hyperosmotic perfusates on albumin synthesis and release

International Nuclear Information System (INIS)

Rothschild, M.A.; Oratz, M.; Schreiber, S.S.; Mongelli, J.

1986-01-01

Sucrose and ethanol inhibit albumin synthesis; sucrose via an osmotic mechanism and ethanol during its metabolism. The present study was undertaken to compare the effects of both of these agents on albumin synthesis and secretion, and to see if ethanol inhibition could be related to an osmotic effect. Male, fed rabbits served as liver donors in all studies. There were a total of 35 studies: 13 control; 10 ethanol (39 to 52 mM); 4 cycloheximide (0.5 mM), and 8 sucrose (1%). Plasma volume was measured with 125 I-albumin (human) and extracellular volume measured with either /sup 99m/Tc diethylenetriamine pentaacetic acid or [ 14 C]sucrose. During perfusion, rabbit albumin content in the perfusate was measured immunologically every 15 to 30 min for 225 min. Interstitial albumin efflux was measured by the rate of appearance in the perfusate of 125 I-albumin given to 10 other rabbits 3 days prior to hepatic removal and perfusion. During the initial 75 min of perfusion, 74% of the in vivo equilibrated exchangeable 125 I-albumin appeared in the perfusate, and during this period the rabbit albumin that entered the perfusate was taken to represent efflux from the interstitial volume plus synthesis. Rabbit albumin appearing in the perfusate during the later period of 150 min was taken to represent mainly synthesis and was used to calculate the amount of albumin that would be synthesized in 75 min. The difference between these two values would be hepatic interstitial albumin appearing in the perfusate

Intra-voxel incoherent motion perfusion MR Imaging: a wake-up call

Energy Technology Data Exchange (ETDEWEB)

Le Bihan, D. [CEA Saclay, DSV, I2BM, F-91191 Gif Sur Yvette (France)

2008-07-01

This work gives the results of several studies made by different authors on IVIM MR Imaging. It appears that there are genuine potential applications for IVIM MR imaging. Perfusion is a very important surrogate marker of many physiologic or pathologic processes. MR imaging perfusion parameters can be obtained by using gadolinium-based contrast agents, either injected as a bolus (to determine blood flow, transit times, etc) or in a steady-state mode (to address blood volume, vessel permeability, etc). With the rising concern of nephrogenic systemic fibrosis, some patients cannot be examined with such an approach. IVIM MR imaging may then appear as an interesting alternative to provide crucial clues on perfusion in tissues, such as the kidneys, the liver, or even the placenta during pregnancy. (O.M.)

Intra-voxel incoherent motion perfusion MR Imaging: a wake-up call

International Nuclear Information System (INIS)

Le Bihan, D.

2008-01-01

This work gives the results of several studies made by different authors on IVIM MR Imaging. It appears that there are genuine potential applications for IVIM MR imaging. Perfusion is a very important surrogate marker of many physiologic or pathologic processes. MR imaging perfusion parameters can be obtained by using gadolinium-based contrast agents, either injected as a bolus (to determine blood flow, transit times, etc) or in a steady-state mode (to address blood volume, vessel permeability, etc). With the rising concern of nephrogenic systemic fibrosis, some patients cannot be examined with such an approach. IVIM MR imaging may then appear as an interesting alternative to provide crucial clues on perfusion in tissues, such as the kidneys, the liver, or even the placenta during pregnancy. (O.M.)

Effects of Electroacupuncture Stimulation at “Zusanli” Acupoint on Hepatic NO Release and Blood Perfusion in Mice

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Shu-you Wang

2015-01-01

Full Text Available The study is to observe the influence of electroacupuncture (EA stimulation at “Zusanli” (ST36 on the release of nitric oxide (NO and blood perfusion (BP in the liver and further explore whether the hepatic blood perfusion (HBP changes were regulated by EA ST36 induced NO in nitric oxide synthase inhibited mice. The HBP change of the mice was detected by laser speckle perfusion imaging (LSPI before and after being given interventions, and the NO in liver tissue was detected by nitric acid reductase in each group. The NO levels and HBP in the L-NAME group were significantly lower than those in the control group (P<0.01. The NO level and HBP increase in EA group were significantly higher than those in control group (P<0.05. The NO level in the L-NAME EA group was slightly higher than that in the L-NAME group. The HBP increase in the L-NAME EA group was not statistically significant. These results showed that EA could accelerate the synthesis of NO and thereby increase HBP via vasodilation in liver tissue.

Organ perfusion during voluntary pulmonary hyperinflation; a magnetic resonance imaging study

DEFF Research Database (Denmark)

Kristensen, Kasper Kyhl; Drvis, Ivan; Barak, Otto

2016-01-01

. Myocardial, pulmonary, skeletal muscle, kidney, and liver perfusion were evaluated by magnetic resonance imaging in 10 elite breath-hold divers at rest and during moderate GPI. Cardiac chamber volumes, stroke volume, and thus CO were determined from cardiac short-axis cine images. Organ volumes were assessed...

VEGFR-2 expression in HCC, dysplastic and regenerative liver nodules, and correlation with pre-biopsy Dynamic Contrast Enhanced CT

Energy Technology Data Exchange (ETDEWEB)

Thaiss, W.M., E-mail: wolfgang.thaiss@med.uni-tuebingen.de [Eberhard Karls University, Department of Radiology, Diagnostic and Interventional Radiology, Hoppe-Seyler-Str. 3, D-72076 Tuebingen (Germany); Kaufmann, S., E-mail: sascha.kaufmann@med.uni-tuebingen.de [Eberhard Karls University, Department of Radiology, Diagnostic and Interventional Radiology, Hoppe-Seyler-Str. 3, D-72076 Tuebingen (Germany); Kloth, C., E-mail: christopher.kloth@med.uni-tuebingen.de [Eberhard Karls University, Department of Radiology, Diagnostic and Interventional Radiology, Hoppe-Seyler-Str. 3, D-72076 Tuebingen (Germany); Nikolaou, K., E-mail: konstantin.nikolaou@med.uni-tuebingen.de [Eberhard Karls University, Department of Radiology, Diagnostic and Interventional Radiology, Hoppe-Seyler-Str. 3, D-72076 Tuebingen (Germany); Bösmüller, H., E-mail: hans.boesmueller@med.uni-tuebingen.de [Eberhard Karls University, Department of Pathology, Liebermeisterstraße 8, D-72076 Tuebingen (Germany); Horger, M., E-mail: Marius.Horger@med.uni-tuebingen.de [Eberhard Karls University, Department of Radiology, Diagnostic and Interventional Radiology, Hoppe-Seyler-Str. 3, D-72076 Tuebingen (Germany)

2016-11-15

Highlights: • VEGFR-2-expression levels vary between HCC, dysplastic and regenerative liver nodules. • Perfusion parameters vary between these groups in blood flow, blood volume and HPI. • Strong correlations were observed between perfusion parameters and VEGFR-2-expression. • The results might influence diagnosis and therapy of anti-vascular therapeutic regimes. - Abstract: Purpose: To evaluate whether VEGFR-2-expression in hepatocellular carcinoma (HCC), dysplastic (DLN) and regenerative liver nodules (RLN) correlates with pre-histology, in vivo Dynamic Contrast Enhanced-Computed Tomography (DCE-CT) data as VEGFR-2-expression affects prognosis and therapeutic options. Materials and methods: 34 patients (63.6 ± 8.9 years, 7 females) underwent liver biopsy or surgery due to suspected HCC or dysplastic nodules after DCE-CT between 2009 and 2015 with no previous chemo- or interventional therapy. Immunohistochemistry staining for VEGFR-2 was performed using Immunoreactive-Remmele-Stegner-Score (IRS) for quantification. A 128-row CT-scanner was used for DCE-CT with assessment of perfusion parameters blood flow (BF), blood volume (BV), arterial liver perfusion (ALP), portal venous perfusion (PVP), and hepatic perfusion index (HPI). Results: Histology confirmed HCC (n = 10), DLN (n = 7) and RLN (n = 34). Mean IRS for VEGFR-2 in HCCs was 9.1 ± 3.0, 7.3 ± 1.6 for DLN and 5.2 ± 2.8 for RLN (p = 0.0004 for HCC vs. RLN). Perfusion values varied significantly between all three groups for BF and HPI (p < 0.001 and p < 0.0001) and for BV in HCC vs. RLN (p < 0.0001) and DLN vs. RLN (p = 0.0019). Strong correlations between VEGFR-2-IRS and perfusion parameters were observed for BF in HCC (r = 0.88, p < 0.01) and HPI in HCC and DLN (r = 0.85, p < 0.04; r = 0.9, p < 0.01). Conclusion: Immunostaining revealed different VEGFR-2-expression levels in HCC, dysplastic and regenerative liver nodules. Perfusion markers blood flow, blood volume and hepatic perfusion index

Analysis of liver blood flow by dynamic hepatic scintigraphy

International Nuclear Information System (INIS)

Xie Tianhao; Jia Shiquan

1996-01-01

Liver blood flow was studied in 45 patients with solitary malignant liver cancer, 17 patients with multiple liver metastases, 18 patients with benign liver tumor and 20 control subjects by dynamic hepatic scintigraphy. The hepatic perfusion index (HPI) in control subjects, patients with liver malignant cancer and benign tumor was 0.33 +- 0.069, 0.589 +- 0.084, 0.384 +-0.046 respectively, and the mesenteric fraction (MF) was 0.56 +- 0.054, 0.246 +- 0.064, 0.524 +- 0.086 respectively. In conclusion, flow scintigraphy is a non-invasive, sensitive and repeatable method for detection of liver tumor

Association Between MC-2 Peptide and Hepatic Perfusion and Liver Injury Following Resuscitated Hemorrhagic Shock.

Science.gov (United States)

Matheson, Paul J; Fernandez-Botran, Rafael; Smith, Jason W; Matheson, Samuel A; Downard, Cynthia D; McClain, Craig J; Garrison, Richard N

2016-03-01

Hemorrhagic shock (HS) due to trauma remains a major cause of morbidity and mortality in the United States, despite continuing progression of advanced life support and treatment. Trauma is the third most common cause of death worldwide and is the leading cause of death in the 1- to 44-year-old age group. Hemorrhagic shock often progresses to multiple organ failure despite conventional resuscitation (CR) that restores central hemodynamics. To examine whether MC-2 would bind glycosaminoglycans to decrease proinflammatory cytokines' influence in the liver, minimize organ edema, prevent liver injury, and improve hepatic perfusion. MC-2, a synthetic octapeptide derived from the heparin-binding domain of murine interferon gamma (IFN-γ), binds glycosaminoglycans to modulate serum and interstitial cytokine levels and activity. A controlled laboratory study of 3y male Sprague-Dawley rats that were randomized to 4 groups of 8 each: sham, sham+MC-2 (50 mg/kg), HS/CR, or HS/CR+MC-2 (HS = 40% of baseline mean arterial pressure for 60 minutes; CR = return of shed blood and 2 volumes of saline). The study began in March, 2013. Effective hepatic blood flow (EHBF) by galactose clearance, wet-dry weights, cytokines, histopathology, complete metabolic panel, and complete blood cell count were performed at 4 hours after CR. MC-2 partially reversed the HS/CR-induced hepatic hypoperfusion at 3 and 4 hours postresuscitation compared with HS/CR alone. Effective hepatic blood flow decreased during the HS period from a mean (SD) of 7.4 (0.3) mL/min/100 g and 7.5 (0.5) mL/min/100g at baseline to 3.7 (0.4) mL/min/100g and 5.9 (0.5) mL/min/100g for the HS/CR and HS/CR+MC-2 groups, respectively (P hepatic blood flow remained constant in the sham groups throughout the experimental protocol. Organ edema was increased in the ileum and liver in the HS/CR vs sham group, and MC-2 decreased edema in the ileum vs the HS/CR group. MC-2 in HS also decreased levels of alanine aminotransferase

Evaluation of rat liver apoptotic and necrotic cell death after cold storage using UW, HTK, and Celsior

NARCIS (Netherlands)

Straatsburg, Irene H.; Abrahamse, Salomon L.; Song, Shao W.; Hartman, Robin J.; van Gulik, Thomas M.

2002-01-01

Background. The benefit of Celsior in liver graft preservation is controversial. In the isolated perfused rat liver model, we compared the effects of Celsior, University of Wisconsin (UW), and histidine-tryptophan-ketoglutarate (HTK) preservation solutions on liver cell death. Methods. Rat livers

NORMOTHERMIC EXTRACORPOREAL PERFUSION IN SITU IN DECEASED ORGAN DONORS WITH IRREVERSIBLE CARDIAC ARREST AND ONE HOUR OF ASYSTOLE. 5-YEAR OUTCOMES OF KIDNEY TRANSPLANTATION

Directory of Open Access Journals (Sweden)

A. E. Skvortsov

2016-01-01

Full Text Available Aim. The global shortage of deceased organ donors caused increasing interest to the transplant program based on the use of organs from the donors with sudden irreversible cardiac arrest, or asystolic donors (DCD. Ischemia-reperfusion injury as a result of cardiac arrest remains a key problem that limits the use of organs from DCD. Our clinical study was intended to determine the acceptability of renal transplants derived from the DCD using extracorporeal perfusion in situ after 60 minutes of asystole. Materials and methods. In 2009–2014, St. Petersburg Organ Procurement Organization (OPO obtained kidneys from 29 DCD with critically expanded warm ischemic time (WIT. The design of this study was approved by the Scientifi c Board and Ethics Committee of the State Research Institute for Emergency Medicine (Decision 7/0615/09. Initially, no one of died patients was considered as potential organ donors. In case of failed advanced CPR the death of a patient was declared initiating the protocol of subnormothermic extracorporeal abdominal perfusion with ECMO, thrombolytics (strepokinase 1.5 mln U, and LD. The procedures were established by the authorized OPO team which arrived with perfusion equipment in 30–40 minutes after declaration of donors’ death. Mean WIT was 58.1 (19.39 minutes (Mean (SD. Resuscitated grafts were transplanted into 58 recipients. The outcomes of transplantation of resuscitated kidneys were compared to those of 112 KTx from 115 brain death donors (BDDs. Results. Immediate functioning of kidney grafts was observed in 28 (48.3% of 58 recipients. There were 4 cases of primary graft non-function. By the end of the fi rst post-transplant year there was an acute rejection rate of 12.1% (9 episodes of rejection in the DCD group vs. 23.2% (26 episodes of rejection in the BDD group (p < 0.05. The actuarial 5-year graft survival rate was 82.8% (n = 48 in DCD group, and 87.5% (n = 98 in BDD group (p > 0.05. Creatinine levels at the end

When is reacquisition necessary due to high extra-cardiac uptake in myocardial perfusion scintigraphy?

DEFF Research Database (Denmark)

Johansen, Allan; Lomsky, Milan; Gerke, Oke

2013-01-01

Technetium-labeled agents, which are most often used for assessing myocardial perfusion in myocardial perfusion scintigraphy (MPS), are cleared by the liver and excreted by the biliary system. Spillover from extra-cardiac activity into the myocardium, especially the inferior wall, might conceal d...... defects and lower the diagnostic accuracy of the study. The objective was to determine rules of thumb for when reacquisition is useful due to high extra-cardiac uptake, i.e., when interpretation of the studies was affected by poor image quality....

Introduction of a MR-compatible system for extracorporal perfusion of vital organs for MR-guided procedures. First-experiences

International Nuclear Information System (INIS)

Gaffke, Gunnar; Nagel, Stefan; Hegemann, Olaf; Speck, Ulrich; Grosse-Siestrup, Christian; Jungnickel, Kerstin; Stroszczynski, Christian

2009-01-01

Purpose:To represent a MRI-compatible perfusion-system for extracorporeal perfusion of vital organs which permits the realisation of realistic experiments in a MR scanner. Material and methods: We performed MR examinations of explanted porcine livers and MR-guided interventions in porcine livers. Explanted organs were hemo-perfused under physiological conditions during the experiments. MR-sequences for diagnostic and interventional examinations were used. Results:The evaluated system was MRI-compatible. The achieved image quality of the used sequences showed excellent anatomical resolution. Planned experiments can be carried out with relatively low expenditure. Diagnostic as well as interventional investigations can be carried out. The used organs showed a stable function within physiological parameters up to 4 hours. Conclusion:It is possible to perform ex vivo experiments under in vivo conditions with this system. With the used MR-compatible system MR-guided experimental interventions and thermal ablations can be carried out in explanted organs under in vivo conditions. (orig.)

Effect of in situ hypothermic perfusion on intrahepatic pO(2) and reactive oxygen species formation after partial hepatectomy under total hepatic vascular exclusion in pigs

NARCIS (Netherlands)

Heijnen, Bob H. M.; Straatsburg, Irene H.; Kager, Liesbeth M.; van der Kleij, Ad J.; Gouma, Dirk J.; van Gulik, Thomas M.

2003-01-01

Aim: This study examined attenuation of ischemia and reperfusion (I/R) induced liver injury during liver resections by hypothermic perfusion of the liver under total hepatic vascular exclusion (THVE). Method: Reactive oxygen species (ROS) formation, microcirculatory integrity and endothelial cell

Nascent VLDL from liver perfusions of cynomolgus monkeys are preferentially enriched in RRR- compared with SRR-alpha-tocopherol: Studies using deuterated tocopherols

International Nuclear Information System (INIS)

Traber, M.G.; Rudel, L.L.; Burton, G.W.; Hughes, L.; Ingold, K.U.; Kayden, H.J.

1990-01-01

The transport and secretion of vitamin E in lipoproteins have been studied in cynomolgus monkeys fed tocopherols labeled with different amounts of deuterium. The animals were fed a single dose of vitamin E containing 60 mumol of each 2R,4'R,8'R-alpha-(5,7-(C2H3)2)tocopheryl acetate (d6-RRR-alpha-tocopheryl acetate; alpha-tocopherol with natural stereochemistry), 2S,4'R,8'R-alpha-5-(C2H3)tocopheryl acetate (d3-SRR-alpha-tocopheryl acetate; alpha-tocopherol with unnatural stereochemistry), and 2R,4'R,8'R-gamma-(3,4-2H)tocopherol (d2-RRR-gamma-tocopherol; gamma-tocopherol with natural stereochemistry). Chylomicrons, as well as the other plasma lipoproteins, contained equal concentrations of all three tocopherols at the earliest time points after feeding suggesting that all three tocopherols were absorbed equally. At later times plasma lipoproteins became preferentially enriched in d6-RRR-alpha-tocopherol. This is likely to be due to hepatic secretion of VLDL (very low density lipoproteins) and other lipoproteins, which were enriched in d6-RRR-alpha-tocopherol, as demonstrated in the lipoproteins isolated from perfused livers that had been obtained 24 h following the administration of the deuterated tocopherols. Taken together these data demonstrate that the liver, not the intestine, is the likely site of discrimination between tocopherol isomers and that the liver secretes nascent lipoproteins preferentially enriched in d6-RRR-alpha-tocopherol

Perfusion-induced changes in cardiac contractility depend on capillary perfusion.

Science.gov (United States)

Dijkman, M A; Heslinga, J W; Sipkema, P; Westerhof, N

1998-02-01

The perfusion-induced increase in cardiac contractility (Gregg phenomenon) is especially found in heart preparations that lack adequate coronary autoregulation and thus protection of changes in capillary pressure. We determined in the isolated perfused papillary muscle of the rat whether cardiac muscle contractility is related to capillary perfusion. Oxygen availability of this muscle is independent of internal perfusion, and perfusion may be varied or even stopped without loss of function. Muscles contracted isometrically at 27 degrees C (n = 7). During the control state stepwise increases in perfusion pressure resulted in all muscles in a significant increase in active tension. Muscle diameter always increased with increased perfusion pressure, but muscle segment length was unaffected. Capillary perfusion was then obstructed by plastic microspheres (15 microns). Flow, at a perfusion pressure of 66.6 +/- 26.2 cmH2O, reduced from 17.6 +/- 5.4 microliters/min in the control state to 3.2 +/- 1.3 microliters/min after microspheres. Active tension developed by the muscle in the unperfused condition before microspheres and after microspheres did not differ significantly (-12.8 +/- 29.4% change). After microspheres similar perfusion pressure steps as in control never resulted in an increase in active tension. Even at the two highest perfusion pressures (89.1 +/- 28.4 and 106.5 +/- 31.7 cmH2O) that were applied a significant decrease in active tension was found. We conclude that the Gregg phenomenon is related to capillary perfusion.

Dynamic determination of kinetic parameters for the interaction between polypeptide hormones and cell-surface receptors in the perfused rat liver by the multiple-indicator dilution method

International Nuclear Information System (INIS)

Sato, H.; Sugiyama, Y.; Sawada, Y.; Iga, T.; Sakamoto, S.; Fuwa, T.; Hanano, M.

1988-01-01

Hepatic elimination of epidermal growth factor (EGF) via receptor-mediated endocytosis was studied by a multiple-indicator dilution method in the isolated perfused rat liver, in which cell polarity and spatial organization are maintained. In this method EGF was given with inulin, an extracellular reference, as a bolus into the portal vein, and dilution curves of both compounds in the hepatic vein effluent were analyzed. Analysis of the dilution curve for EGF, compared with that for somatostatin, which showed no specific binding to isolated liver plasma membranes, resulted as follows: (i) both extraction ratio and distribution volume of 125 I-labeled EGF decreased as the injected amount of unlabeled EGF increased; (ii) the ratio plot of the dilution curve for EGF exhibited an upward straight line initially for a short period of time, whereas the ratio plot of somatostatin gradually decreased. The multiple-indicator dilution method was used for other peptides also. Insulin and glucagon, known to have hepatocyte receptors, behaved similarly to EGF in shape of their ratio plots. The kinetic parameters calculated by this analysis were comparable with reported values obtained by in vitro direct binding measurements at equilibrium using liver homogenates. They conclude that the multiple-indicator dilution method is a good tool for analyzing the dynamics of peptide hormones-cell-surface receptor interaction under a condition in which spatial architecture of the liver is maintained

Temperature and oxygenation during organ preservation: friends or foes?

Science.gov (United States)

Gilbo, Nicholas; Monbaliu, Diethard

2017-06-01

The liberalization of donor selection criteria in organ transplantation, with the increased use of suboptimal grafts, has stimulated interest in ischemia-reperfusion injury prevention and graft reconditioning. Organ preservation technologies are changing considerably, mostly through the reintroduction of dynamic machine preservation. Here, we review the current evidence on the role of temperature and oxygenation during dynamic machine preservation. A large but complex body of evidence exists and comparative studies are few. Oxygenation seems to support an advantageous effect in hypothermic machine preservation and is mandatory in normothermic machine preservation, although in the latter, supraphysiological oxygen tensions should be avoided. High-risk grafts, such as suboptimal organs, may optimally benefit from oxygenated perfusion conditions that support metabolism and activate mechanisms of repair such as subnormothermic machine preservation, controlled oxygenated rewarming, and normothermic machine preservation. For lower risk grafts, oxygenation during hypothermic machine preservation may sufficiently reduce injuries and recharge the cellular energy to secure functional recovery after transplantation. The relationship between temperature and oxygenation in organ preservation is more complex than physiological laws would suggest. Rather than one default perfusion temperature/oxygenation standard, perfusion protocols should be tailored for specific needs of grafts of different quality.

Splenic Artery Syndrome After Orthotopic Liver Transplantation: Treatment With the Amplatzer Vascular Plug

International Nuclear Information System (INIS)

Maurer, M. H.; Mogl, M. T.; Podrabsky, P.; Denecke, T.; Grieser, C.; Fröling, V.; Scheurig-Münkler, C.; Guckelberger, O.; Kroencke, T. J.

2011-01-01

Purpose: To evaluate the safety and efficacy of the Amplatzer vascular plug (AVP) for embolization of the splenic artery in patients with hepatic hypoperfusion after orthotopic liver transplantation (OLT). Materials and Methods: Thirteen patients (9 men and 4 women) with a mean age of 56 years (range 22–70) who developed splenic artery syndrome after OLT with decreased liver perfusion and clinically relevant impairment of liver function (increased transaminase or serum bilirubin levels, thrombocytopenia, and/or therapy-refractory ascites) were treated by embolization of the proximal third of the splenic artery using the AVP. The plugs ranged in diameter from 6 to 16 mm, and they were introduced through femoral (n = 9), axillary (n = 3), or brachial (n = 1) access using a 5F or 8F guiding catheter. Results: The plugs were successfully placed, and complete occlusion of the splenic artery was achieved in all patients. Placement of two plugs was necessary for complete occlusion in 3 of the 13 patients. Occlusion took on average 10 min (range 4–35). There was no nontarget embolization or plug migration into more distal segments of the splenic artery. All patients showed improved arterial perfusion, including the liver periphery, on postinterventional angiogram. After embolization, liver function parameters (transaminase and bilirubin levels) improved with normalization of concomitant thrombocytopenia and a decrease in ascites volume. Conclusion: Our initial experience in a small patient population with SAS suggests that the AVP enables precise embolization of the proximal splenic artery, thus providing safe and effective treatment for poor liver perfusion after OLT due to SAS.

In vivo efficiency of four commercial monopolar radiofrequency ablation systems: a comparative experimental study in pig liver.

Science.gov (United States)

Brieger, Jens; Pereira, Philippe L; Trübenbach, Jochen; Schenk, Martin; Kröber, Stefan-Martin; Schmidt, Diethard; Aubé, Christophe; Claussen, Claus D; Schick, Fritz

2003-10-01

To evaluate the efficiency of 4 radiofrequency (RF) systems by assessing the amount of delivered energy for each thermal induced lesion after perfusion mediated RF ablation and to compare the influence of perfusion mediation types on the energy efficiency. A total of 43 ablations in 16 male landrace pigs with 4 RF devices were performed strictly according to the manufacturers' instructions. Total absorbed energy was computed and then related to 3D volumetry obtained after histopathological evaluation. Sixteen ablations were performed under physiological liver perfusion and 27 ablations with occlusion of portal vein, hepatic artery, or both vessels. Energy efficiency values of the RF systems for different vascular occlusion techniques were compared and analyzed by a nonparametrical rank sum test. Under physiological perfusion, the average energy delivered to produce 1-cm3 lesion size was calculated to 1650 +/- 929, 3097 +/- 389, 8312 +/- 2068, and 5493 +/- 2306 Watt x s/cm3 for the Berchtold, Radionics, Radiotherapeutics, and RITA system, respectively. After perfusion-mediated RF ablation, artery occlusion was not as effective as portal vein occlusion, which reduced the energy to 587 +/- 148, 869 +/- 276, and 903 +/- 394 Watt. s/cm3 for the Berchtold, Radionics, and Radiotherapeutics system, respectively. The occlusion of vessels, portal vein, and artery or portal vein alone increased the energy efficiency compared with physiological liver perfusion or occlusion of the artery (P = 0,003). Under physiological liver perfusion the open perfused system and the internally cooled system provided the best efficiency values with lowest standard deviations. The energy efficiency was increased markedly for all systems after occlusion of the portal vein either alone or in combination with arterial occlusion. Occlusion of the hepatic artery did not improve the efficiency.

Evaluation of liver hemodynamics using SPIO-enhanced dynamic MRI. Comparison between cirrhotic liver and normal liver

International Nuclear Information System (INIS)

Shimada, Kotaro; Kobayashi, Hisato; Furuta, Akihiro; Nunoura, T.; Takahashi, Takahiro; Ogasawara, Nobuhiko; Akuta, Keizo

2006-01-01

SPIO, ferucarbotran (Resovist), which enables rapid bolus injection is well suited for the evaluation of liver hemodynamics. Our study aimed to assess the difference of hemodynamics associated with progression of chronic liver disease using SPIO-enhanced dynamic MRI. Ten patients with normal liver function, 10 patients with chronic hepatitis, and 16 patients with liver cirrhosis were examined. The MR perfusion studies were performed by 1.5T MR system with a single-shot GRE-EPI with spectral presaturation inversion recovery (SPIR) and sensitivity encoding (SENSE) technique. After the bolus injection of SPIO (0.016 ml/kg) followed by a 20 ml saline flush, 30 sequential dynamic echo planar images were obtained under the condition of 30 seconds breath hold. From the ROI set in the right lobe of the liver, time-to-signal intensity curves (TICs) were obtained. TICs were converted to time-to-R2 * curves, and the slope at hepatic arterial phase (Sa) and at portal predominant phase (Sp) were calculated by the linear regression. Sp/Sa (portal/arterial ratio) of each group was analyzed statistically. (unpaired T-test) In comparing Sp/Sa of each group, there was a significant difference between normal liver and advanced liver cirrhosis. The decrease of Sp/Sa was seen in severe cirrhosis, but this change was unclear in chronic hepatitis and mild cirrhosis. In extremely severe cirrhosis, there was a bizarre phenomenon that Sp became minus number. In conclusion, SPIO-enhanced dynamic MRI was useful to assess the difference of liver hemodynamics associated with progression of chronic liver disease. (author)

Liver Function in the Pig

African Journals Online (AJOL)

1974-06-12

Jun 12, 1974 ... The assessment of function of the isolated perfused liver remains complex. Much of this problem relates to an inability to compare function in vitro with that in vivo, because of a lack of knowledge of hepatic blood flow. This article documents measurement of total hepatic and portal blood flow in vivo in pigs, ...

The correlation of CT perfusion imaging with microvessel density and vascular endothelial growth factor in hepatic alveolar echinococcosis

International Nuclear Information System (INIS)

Wang Jing; Ren Bo; Liu Wenya; Wen Hao; Qing Song; Xie Weidong; Sun Yajing; Wang Haitao

2011-01-01

Objective: To explore the correlation of CT perfusion imaging with microvessel density (MVD) and vascular endothelial growth factor (VEGF) in hepatic alveolar echinococcosis (HAE). Methods: Multi-slice spiral CT perfusion imaging was performed in 27 patients with HAE. Time-density curves(TDC) of the HAE peripheral area was drawn from the region of interest (ROI) with perfusion functional software. CT perfusion parameters including blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) were calculated. MVD and VEGF expression of pathological specimens were examined by immunohistochemical staining with anti-CD34, anti-VEGF monoclonal antibody. The CT perfusion parameters, MVD and VEGF were compared in different types of TDC with t test. The correlation of CT perfusion parameters with MVD and VEGF were analyzed with Spearman test. Results: In this group, 21 cases which TDC lower than that of the liver were classified as type Ⅰ, the others 6 cases TDC higher than the liver were of type Ⅱ TDC. TDC perfusion parameters of the two types were as follows, BF: (111.7±27.6), (158.9±39.5) ml · 100 g -1 · min -1 , BV: (15.1±6.2) , (26.8±8.4) ml/100 g, MTT: (7.0±4.4), (7.7±3.1) s, PS: (51.7±17.3), (51.0±20.5) ml ·100 g -1 · min -1 . The significant differences of BF, BV and MVD [(20.5±5.4)/HP, (37.2±7.5)/HP, respectively] were found between two types (t=-7.897, -18.783, -5.223, P 0.05). The correlation was found between the MVD and BF and BV in the type Ⅱ TDC group (r=0.789 and 0.878, respectively) and no correlation was found between MVD and each CT perfusion parameters in the type Ⅰ TDC group (P>0.05). There was no correlation between the VEGF expression and CT perfusion parameters in two types of TDC (P>0.05). Conclusion: CT perfusion imaging with different type of TDC reflected different situation of angiogenesis in HAE peripheral area, which could be a potential technique to illustrate the

Recellularization of rat liver: An in vitro model for assessing human drug metabolism and liver biology.

Directory of Open Access Journals (Sweden)

Matthew J Robertson

Full Text Available Liver-like organoids that recapitulate the complex functions of the whole liver by combining cells, scaffolds, and mechanical or chemical cues are becoming important models for studying liver biology and drug metabolism. The advantages of growing cells in three-dimensional constructs include enhanced cell-cell and cell-extracellular matrix interactions and preserved cellular phenotype including, prevention of de-differentiation. In the current study, biomimetic liver constructs were made via perfusion decellularization of rat liver, with the goal of maintaining the native composition and structure of the extracellular matrix. We optimized our decellularization process to produce liver scaffolds in which immunogenic residual DNA was removed but glycosaminoglycans were maintained. When the constructs were recellularized with rat or human liver cells, the cells remained viable, capable of proliferation, and functional for 28 days. Specifically, the cells continued to express cytochrome P450 genes and maintained their ability to metabolize a model drug, midazolam. Microarray analysis showed an upregulation of genes involved in liver regeneration and fibrosis. In conclusion, these liver constructs have the potential to be used as test beds for studying liver biology and drug metabolism.

Utilization by the isolated perfused rat liver of N-acetyl-D-(1-/sup 14/C)galactosamine and N-brace/sup 3/H)-acetyl-D-galactosamine for the biosynthesis of glycoproteins

Energy Technology Data Exchange (ETDEWEB)

MacNicoll, A D; Wusteman, F S; Powell, G M; Curtis, C G [University Coll., Cardiff (UK)

1978-08-15

The isolated perfused rat liver system has been used to monitor the utilization of N-(/sup 3/H)acetyl-D-galactosamine and N-acetyl-D-(1-/sup 14/C)galactosamine for the biosynthesis of radiolabeled glycoproteins, which are subsequently secreted into the plasma. Both radiolabels appear in a number of different glycoproteins, predominantly as sialic acid and N-acetylglucosamine. The ratio of labelled sialic acid to labelled N-acetylglucosamine varies for different glycoproteins, but the bulk of N-acetyl-D-galactosamine is incorporated without deacetylation.

Organ hierarchy during low blood flow on-pump: a randomized experimental positron emission tomography study

DEFF Research Database (Denmark)

Thomassen, Sisse Anette; Kjærgaard, Benedict; Frøkiær, Jørgen

will be measured with dynamic PET-CT before CPB and during the different blood flows. Systemic oxygen consumption will be estimated by measurement of mixed venous saturation and lactate, and regional muscle oxygen saturation (tSO2) with near infrared spectroscopy at the lower limb. Result: Preliminary data......].The purpose of this animal study is to investigate the organ hierarchy of brain, liver, kidney and muscle at normal and low blood flows by using dynamic positron tomography (PET-CT) during CPB. Methods CPB at different blood flows will be investigated in an experimental model of six 70 kg pigs...... knowledge this is the first study investigating organ hierarchy with dynamic PET-CT during profound systemic ischemia due to suboptimal blood flows during normothermic CPB. References 1. Murphy JM, Hessel II EA, Groom RC. Optimal perfusion during cardiopulmonary bypass: an Evidence-based approach. Anesth...

Phosphorus NMR of isolated perfused morris hepatomas

International Nuclear Information System (INIS)

Graham, R.A.; Meyer, R.A.; Brown, T.R.; Sauer, L.A.

1986-01-01

The authors are developing techniques for the study of perfused solid tumors by NMR. Tissue-isolated solid hepatomas were grown to 1-2 cm diameter as described previously. The arterial supply was isolated and the tumors perfused (0.5 - 1.0 ml/min) in vitro at 25 C with a 15% suspension of red blood cells in Krebs-Henseliet solution. 31 P-NMR spectra were acquired at 162 MHz in a specially-designed NMR probe using a solenoidal coil. Intracellular pH (monitored from the chemical shift of inorganic phosphate) and ATP levels were stable for up to 6 hrs during perfusion. During 30 min of global ischemia, ATP decreased by 75% and pH fell from 7.0 to 6.7. These changes were reversed by 1 hr reperfusion. In addition to ATP and phosphate, the spectra included a large resonance due to phosphomonoesters, as well as peaks consistent with glycerylphosphocholine, glyceryl-phosphoethanolamine, phosphocreatine, NAD, and UDPG. However, the most novel feature of the spectra was the presence of an unidentified peak in the phosphonate region (+ 16.9 ppm). The peak was not present in spectra of muscle, liver, brain, kidney, or fat tissues excised from the same animals. They are presently attempting to identify the compound that gives rise to this peak and to establish its metabolic origin

Some processes of energy saving and expenditure occurring during ethanol perfusion in the isolated liver of fed rats; a Nuclear Magnetic Resonance study.

Directory of Open Access Journals (Sweden)

Gin Henri

2004-03-01

Full Text Available Abstract Background In the isolated liver of fed rats, a 10 mM ethanol perfusion rapidly induced a rapid 25% decrease in the total ATP content, the new steady state resulting from both synthesis and consumption. The in situ rate of mitochondrial ATP synthesis without activation of the respiration was increased by 27%, implying an increased energy demand. An attempt to identify the ethanol-induced ATP-consuming pathways was performed using 31P and 13C Nuclear Magnetic Resonance. Results Ethanol (i transiently increased sn-glycerol-3-phosphate formation whereas glycogenolysis was continuously maintained; (ii decreased the glycolytic ATP supply and (iii diminished the intracellular pH in a dose-dependent manner in a slight extend. Although the cytosolic oxidation of ethanol largely generated H+ (and NADH, intracellular pHi was maintained by (i the large and passive excretion of cellular acetic acid arising from ethanol oxidation (evidenced by exogenous acetate administration, without energetic cost or (ii proton extrusion via the Na+-HCO3- symport (implying the indirect activation of the Na+-K+-ATPase pump and thus an energy use, demonstrated during the addition of their specific inhibitors SITS and ouabaïn, respectively. Conclusion Various cellular mechanisms diminish the cytosolic concentration of H+ and NADH produced by ethanol oxidation, such as (i the large but transient contribution of the dihydroxyacetone phosphate / sn-glycerol-3-phosphate shuttle between cytosol and mitochondria, mainly implicated in the redox state and (ii the major participation of acetic acid in passive proton extrusion out of the cell. These processes are not ATP-consuming and the latter is a cellular way to save some energy. Their starting in conjunction with the increase in mitochondrial ATP synthesis in ethanol-perfused whole liver was however insufficient to alleviate either the inhibition of glycolytic ATP synthesis and/or the implication of Na+-HCO3- symport and

[Brain oedema and acute liver failure].

Science.gov (United States)

Spahr, L

2003-04-01

Brain oedema leading to intracranial hypertension occurs in a significant proportion of patients with acute liver failure in whom it is a leading cause of death. Although precise pathogenic mechanisms associated to this severe complication remain incompletely understood, increasing evidence points to gut-derived neurotoxins including ammonia as key mediators in cerebral osmotic and perfusion disturbances. The management of brain oedema and intracranial hypertension requires a multidisciplinar approach in a center where liver transplantation is available, as this option is the only treatment modality that provides improvement in outcome. This article reviews the most common causes of acute liver failure and the standard of supportive care management, and describes future potential therapeutic aspects of brain oedema and intracranial hypertension.

Quantitative lung perfusion evaluation using Fourier decomposition perfusion MRI.

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Kjørstad, Åsmund; Corteville, Dominique M R; Fischer, Andre; Henzler, Thomas; Schmid-Bindert, Gerald; Zöllner, Frank G; Schad, Lothar R

2014-08-01

To quantitatively evaluate lung perfusion using Fourier decomposition perfusion MRI. The Fourier decomposition (FD) method is a noninvasive method for assessing ventilation- and perfusion-related information in the lungs, where the perfusion maps in particular have shown promise for clinical use. However, the perfusion maps are nonquantitative and dimensionless, making follow-ups and direct comparisons between patients difficult. We present an approach to obtain physically meaningful and quantifiable perfusion maps using the FD method. The standard FD perfusion images are quantified by comparing the partially blood-filled pixels in the lung parenchyma with the fully blood-filled pixels in the aorta. The percentage of blood in a pixel is then combined with the temporal information, yielding quantitative blood flow values. The values of 10 healthy volunteers are compared with SEEPAGE measurements which have shown high consistency with dynamic contrast enhanced-MRI. All pulmonary blood flow (PBF) values are within the expected range. The two methods are in good agreement (mean difference = 0.2 mL/min/100 mL, mean absolute difference = 11 mL/min/100 mL, mean PBF-FD = 150 mL/min/100 mL, mean PBF-SEEPAGE = 151 mL/min/100 mL). The Bland-Altman plot shows a good spread of values, indicating no systematic bias between the methods. Quantitative lung perfusion can be obtained using the Fourier Decomposition method combined with a small amount of postprocessing. Copyright © 2013 Wiley Periodicals, Inc.

A pump-free microfluidic 3D perfusion platform for the efficient differentiation of human hepatocyte-like cells.

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Ong, Louis Jun Ye; Chong, Lor Huai; Jin, Lin; Singh, Pawan Kumar; Lee, Poh Seng; Yu, Hanry; Ananthanarayanan, Abhishek; Leo, Hwa Liang; Toh, Yi-Chin

2017-10-01

The practical application of microfluidic liver models for in vitro drug testing is partly hampered by their reliance on human primary hepatocytes, which are limited in number and have batch-to-batch variation. Human stem cell-derived hepatocytes offer an attractive alternative cell source, although their 3D differentiation and maturation in a microfluidic platform have not yet been demonstrated. We develop a pump-free microfluidic 3D perfusion platform to achieve long-term and efficient differentiation of human liver progenitor cells into hepatocyte-like cells (HLCs). The device contains a micropillar array to immobilize cells three-dimensionally in a central cell culture compartment flanked by two side perfusion channels. Constant pump-free medium perfusion is accomplished by controlling the differential heights of horizontally orientated inlet and outlet media reservoirs. Computational fluid dynamic simulation is used to estimate the hydrostatic pressure heads required to achieve different perfusion flow rates, which are experimentally validated by micro-particle image velocimetry, as well as viability and functional assessments in a primary rat hepatocyte model. We perform on-chip differentiation of HepaRG, a human bipotent progenitor cell, and discover that 3D microperfusion greatly enhances the hepatocyte differentiation efficiency over static 2D and 3D cultures. However, HepaRG progenitor cells are highly sensitive to the time-point at which microperfusion is applied. Isolated HepaRG cells that are primed as static 3D spheroids before being subjected to microperfusion yield a significantly higher proportion of HLCs (92%) than direct microperfusion of isolated HepaRG cells (62%). This platform potentially offers a simple and efficient means to develop highly functional microfluidic liver models incorporating human stem cell-derived HLCs. Biotechnol. Bioeng. 2017;114: 2360-2370. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Renal perfusion scintiscan

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... Radionuclide renal perfusion scan; Perfusion scintiscan - renal; Scintiscan - renal perfusion Images Kidney anatomy Kidney - blood and urine flow Intravenous pyelogram References Rottenberg G, Andi AC. Renal ...

Hepatic computed tomography perfusion. Comparison of maximum slope and dual-input single-compartment methods

International Nuclear Information System (INIS)

Kanda, Tomonori; Yoshikawa, Takeshi; Ohno, Yoshiharu; Kanata, Naoki; Koyama, Hisanobu; Nogami, Munenobu; Takenaka, Daisuke; Sugimura, Kazuro

2010-01-01

The aim of the study was to compare two analytical methods-maximum slope (MS) and the dualinput single-compartment model (CM)-in computed tomography (CT) measurements of hepatic perfusion and to assess the effects of extrahepatic systemic factors. A total of 109 patients underwent hepatic CT perfusion. The scans were conducted at the hepatic hilum 7-77 s after administration of contrast material. Hepatic arterial perfusion (HAP) and portal perfusion (HPP) (ml/min/100 ml) and the arterial perfusion fraction (APF, %) were calculated with the two methods, followed by correlation assessment. Partial correlation analysis was used to assess the effects on hepatic perfusion values by various factors, including age, sex, risk of cardiovascular disease, compensation for respiratory misregistration, arrival time of contrast material at the abdominal aorta, transit time from abdominal aorta to hepatic parenchyma, and liver dysfunction. The mean HAPs, HPPs, and APFs were, respectively, 31.4, 104.2, and 23.9 for MS and 27.1, 141.3, and 22.1 for CM. HAP and APF showed significant (P<0.0001) and moderate correlation (γ=0.417 and 0.548) and HPP showed poor correlation (γ=0.172) between the two methods. While MS showed weak correlations (γ=-0.39 to 0.34; P<0.001 to <0.02) between multiple extrahepatic factors and perfusion values, CM showed weak correlation only between the patients' sex and HAP (γ=0.31, P=0.001). Hepatic perfusion values estimated by the two methods are not interchangeable. CM is less susceptible to extrahepatic systemic factors. (author)

Fructose effect to enhance liver glycogen deposition is due to inhibition of glycogenolysis

International Nuclear Information System (INIS)

Youn, J.; Kaslow, H.; Bergman, R.

1987-01-01

The effect of fructose on glycogen degradation was examined by measuring flux of [ 14 C] from prelabeled glycogen in perfused rat livers. During 2 h refeeding of fasted rats hepatic glycogen was labeled by injection of [U 14 C] galactose (0.1 mg and 0.02 μCi/g of body weight). Refed livers were perfused for 30 min with glucose only (10 mM) and for 60 min with glucose (10 mM) without (n=5) or with fructose (1, 2, 10 mM; n=5 for each). With fructose, label production immediately declined and remained suppressed through the end of perfusion (P < 0.05). Suppression was dose-dependent: steady state label production was suppressed 45, 64, and 72% by 1, 2, and 10 mM fructose (P < 0.0001), without significant changes in glycogen synthase or phosphorylase. These results suggest the existence of allosteric inhibition of phosphorylase in the presence of fructose. Fructose 1-phosphate (F1P) accumulated in proportion to fructose (0.11 +/- 0.01 without fructose, 0.86 +/- 0.03, 1.81 +/- 0.18, and 8.23 +/- 0.6 μmoles/g of liver with 1, 2, and 10 mM fructose. Maximum inhibition of phosphorylase was 82%; FIP concentration for half inhibition was 0.57 μmoles/g of liver, well within the concentration of F1P attained in refeeding. Fructose enhances net glycogen synthesis in liver by suppressing glycogenolysis and the suppression is presumably caused by allosteric inhibition of phosphorylase by F1P

Optimizing Perfusion-Decellularization Methods of Porcine Livers for Clinical-Scale Whole-Organ Bioengineering

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Qiong Wu

2015-01-01

Full Text Available Aim. To refine the decellularization protocol of whole porcine liver, which holds great promise for liver tissue engineering. Methods. Three decellularization methods for porcine livers (1% sodium dodecyl sulfate (SDS, 1% Triton X-100 + 1% sodium dodecyl sulfate, and 1% sodium deoxycholate + 1% sodium dodecyl sulfate were studied. The obtained liver scaffolds were processed for histology, residual cellular content analysis, and extracellular matrix (ECM components evaluation to investigate decellularization efficiency and ECM preservation. Rat primary hepatocytes were seeded into three kinds of scaffold to detect the biocompatibility. Results. The whole liver decellularization was successfully achieved following all three kinds of treatment. SDS combined with Triton had a high efficacy of cellular removal and caused minimal disruption of essential ECM components; it was also the most biocompatible procedure for primary hepatocytes. Conclusion. We have refined a novel, standardized, time-efficient, and reproducible protocol for the decellularization of whole liver which can be further adapted to liver tissue engineering.

Single photon emission computed tomographic studies (SPECT) of hepatic arterial perfusion scintigraphy (HAPS) in patients with colorectal liver metastases: improved tumour targetting by microspheres with angiotensin II.

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Goldberg, J A; Bradnam, M S; Kerr, D J; McKillop, J H; Bessent, R G; McArdle, C S; Willmott, N; George, W D

1987-12-01

As intra-arterial chemotherapy for liver metastases of colorectal origin becomes accepted, methods of further improving drug delivery to the tumour have been devised. Degradable microspheres have been shown to reduce regional blood flow by transient arteriolar capillary block, thereby improving uptake of a co-administered drug, when injected into the hepatic artery. In our study of five patients, we combined hepatic arterial perfusion scintigraphy (HAPS) and SPECT to assess the localization of approximately 1 X 10(5) labelled microspheres of human serum albumin (99Tcm MSA) in tumour. In addition, in three patients, we assessed the effect of an intra-arterial infusion of the vasoactive agent angiotension II during HAPS. Results were interpreted by comparing transaxial slices with corresponding slices of a tin colloid liver-spleen scan. Two of five patients showed good localization of 99Tcm MSA in tumour without an angiotensin II infusion. Of the three patients receiving angiotensin II, all showed good tumour targetting with the vasoconstrictor compared with only one of these three before its use. Thus, hepatic arterial infusion of angiotensin II greatly improves microsphere localization in tumour in some patients with colorectal liver metastases. This technique may be useful in the assessment of tumour targetting before and during locoregional therapy.

[Dynamics of the amino acid composition of the medium during cultivation of isolated organs by the directed perfusion method].

Science.gov (United States)

Barashkov, V A; Gitel'zon, I I; Nefedov, V P; Trubachev, I N

1975-07-01

The dynamics of the amino acid composition of the medium under conditions of adequate perfusion of the isolated organs of a dog (sternum, kidney and liver) was studied. It was found that after a 6-hour perfusion of the complex of organs the amount in the perfusion medium of such amino acids as histidine, lysine, alanine, considerably increased, whereas the amount of arginine, serine, aspartic acid, threonine with glutamine, isoleucine, proline, leucine and valine decreased as compared with their initial concentration. The dynamics of the amino acid medium composition during a 4-hour perfusion was studied in experiments with the isolated sternum. The concentration of alanine, lysine and histidine increased in the medium. At the same time there was seen a decrease in the concentration of serine, aspartic acid, isoleucine, tyrosine and phenyl-alanine.

Bringing physiology into PET of the liver.

Science.gov (United States)

Keiding, Susanne

2012-03-01

Several physiologic features make interpretation of PET studies of liver physiology an exciting challenge. As with other organs, hepatic tracer kinetics using PET is quantified by dynamic recording of the liver after the administration of a radioactive tracer, with measurements of time-activity curves in the blood supply. However, the liver receives blood from both the portal vein and the hepatic artery, with the peak of the portal vein time-activity curve being delayed and dispersed compared with that of the hepatic artery. The use of a flow-weighted dual-input time-activity curve is of importance for the estimation of hepatic blood perfusion through initial dynamic PET recording. The portal vein is inaccessible in humans, and methods of estimating the dual-input time-activity curve without portal vein measurements are being developed. Such methods are used to estimate regional hepatic blood perfusion, for example, by means of the initial part of a dynamic (18)F-FDG PET/CT recording. Later, steady-state hepatic metabolism can be assessed using only the arterial input, provided that neither the tracer nor its metabolites are irreversibly trapped in the prehepatic splanchnic area within the acquisition period. This is used in studies of regulation of hepatic metabolism of, for example, (18)F-FDG and (11)C-palmitate.

Interactions between fatty acid synthesis, oxidation, and esterification in the production of triglyceride-rich lipoproteins by the liver.

Science.gov (United States)

Fukuda, N; Ontko, J A

1984-08-01

In a series of experiments with male rat livers perfused with or without 5-tetradecyloxy-2-furoic acid (TOFA) in the presence and absence of oleate, the relationships between fatty acid synthesis, oxidation, and esterification from newly synthesized and exogenous fatty acid substrates have been examined. When livers from fed rats were perfused without exogenous fatty acid substrate, 20% of the triglyceride secreted was derived from de novo fatty acid synthesis. Addition of TOFA caused immediate and nearly complete inhibition of fatty acid synthesis, measured by incorporation of 3H2O into fatty acids. Concurrently, ketone body production increased 140% and triglyceride secretion decreased 84%. These marked reciprocal alterations in fatty acid synthesis and oxidation in the liver almost completely abolished the production of very low density lipoproteins (VLDL). Cholesterol synthesis was also depressed by TOFA, suggesting that this drug also inhibited lipid synthesis at a site other than acetyl-CoA carboxylase. When livers from fed rats were supplied with a continuous infusion of [1-14C]oleate as exogenous substrate, similar proportions, about 45-47%, of both ketone bodies and triglyceride in the perfusate were derived from the infused [1-14C]oleate. The production of ketone bodies was markedly increased by TOFA; the secretion of triglyceride and cholesterol were decreased. Altered conversion of [1-14C]oleate into these products occurred in parallel. While TOFA decreased esterification of oleate into triglyceride, incorporation of [1-14C]oleate into liver phospholipid was increased, indicating that TOFA also affected glycerolipid synthesis at the stage of diglyceride processing. The decreased secretion of triglyceride and cholesterol following TOFA treatment was localized almost exclusively in VLDL. The specific activities of 3H and of 14C fatty acids in triglyceride of the perfusate were greater than those of liver triglyceride, indicating preferential secretion of

Endocytosis via galactose receptors in vivo. Ligand size directs uptake by hepatocytes and/or liver macrophages

International Nuclear Information System (INIS)

Schlepper-Schaefer, J.; Huelsmann, D.; Djovkar, A.; Meyer, H.E.; Herbertz, L.; Kolb, H.; Kolb-Bachofen, V.

1986-01-01

The intrahepatic binding and uptake of variously sized ligands with terminal galactosyl residues is rat liver was followed. The ligands were administered to prefixed livers in binding studies and in vivo and in situ (serum-free perfused livers) in uptake studies. Gold sols with different particle diameters were prepared: 5 nm (Au 5 ), 17 nm (Au 17 ), 50 nm (Au 50 ) and coated with galactose exposing glycoproteins (asialofetuin (ASF) or lactosylated BSA (LacBSA)). Electron microscopy of mildly prefixed livers perfused with LacBSA-Au 5 in serum-free medium showed ligand binding to liver macrophages, hepatocytes and endothelial cells. Ligands bound to prefixed cell surfaces reflect the initial distribution of receptor activity: pre-aggregated clusters of ligands are found on liver macrophages, single particles statistically distributed on hepatocytes and pre-aggregated clusters of particles restricted to coated pits on endothelial cells. Ligand binding is prevented in the presence of 80 mM N-acetylgalactosamine (GalNAc), while N-acetylglucosamine (GlcNAc) is without effect. Electron microscopy of livers after ligand injection into the tail vein shows that in vivo uptake of electron-dense galactose particles by liver cells is size-dependent. In vivo uptake by liver macrophages is mediated by galactose-specific recognition as shown by inhibition with GalNAc

Riboflavin (vitamin B-2) reduces hepatocellular injury following liver ischaemia and reperfusion in mice.

Science.gov (United States)

Sanches, Sheila Cristina; Ramalho, Leandra Naira Z; Mendes-Braz, Mariana; Terra, Vânia Aparecida; Cecchini, Rubens; Augusto, Marlei Josiele; Ramalho, Fernando Silva

2014-05-01

Riboflavin has been shown to exhibit anti-inflammatory and antioxidant properties in the settings of experimental sepsis and ischaemia/reperfusion (I/R) injury. We investigated the effect of riboflavin on normothermic liver I/R injury. Mice were submitted to 60 min of ischaemia plus saline or riboflavin treatment (30 μmoles/kg BW) followed by 6 h of reperfusion. Hepatocellular injury was evaluated by aminotransferase levels, reduced glutathione (GSH) content and the histological damage score. Hepatic neutrophil accumulation was assessed using the naphthol method and by measuring myeloperoxidase activity. Hepatic oxidative/nitrosative stress was estimated by immunohistochemistry. Liver endothelial and inducible nitric oxide synthase (eNOS/iNOS) and nitric oxide (NO) amounts were assessed by immunoblotting and a chemiluminescence assay. Riboflavin significantly reduced serum and histological parameters of hepatocellular damage, neutrophil infiltration and oxidative/nitrosative stress. Furthermore, riboflavin infusion partially recovered hepatic GSH reserves and decreased the liver contents of eNOS/iNOS and NO. These data indicate that riboflavin exerts antioxidant and anti-inflammatory effects in the ischaemic liver, protecting hepatocytes against I/R injury. The mechanism of these effects appears to be related to the intrinsic antioxidant potential of riboflavin/dihydroriboflavin and to reduced hepatic expression of eNOS/iNOS and reduced NO levels, culminating in attenuation of oxidative/nitrosative stress and the acute inflammatory response. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of radiosensitising agent nicotinamide on relative tissue perfusion and kidney junction in C3H mice

International Nuclear Information System (INIS)

Honess, D.J.; Bleehen, N.M.

1993-01-01

Nicotinamide is an effective radiosensitiser of murine tumours, functioning by improving tumour perfusion by decreasing the proportion of intermittently closed capillaries. The effect of nicotinamide on relative tissue perfusion of RIF-1 tumour and normal skin, muscle, lung, liver, kidney and spleen were investigated using the 86 Rb extraction technique. A dose of 1000 mg/kg was shown to have transient effects on tumour, skin and lung perfusion but to have sustained effects on muscle (a drop to 80% of control), liver, kidney and spleen (with increased ranging from 165% to 280% of control) from 0.5 to 4 h after treatment i.e. during the period of maximum radiosensitisation. These increases were evident at doses as low as 100 mg/kg. The data suggest that the radiosensitisation induced by nicotinamide in the mouse may be associated with these perfusion changes. Nicotinamide was also shown to have a substantial inhibitory effect on renal function, inhibiting 51 CrEDTA clearance by a factor (± 2 SE) of 2.56 ± 0.19 and 125 I-iodohippurate clearance by a factor of 2.07 ± 0.45 at 1000 mg/kg. These effects were shown to be dose-related, and to be evident at doses from 400 mg/kg upwards. This suggests that nicotinamide potentiation of co-administered cytotoxic agents may be mediated by reduced renal clearance of the cytotoxic drug, thus increasing the plasma half-life. (author)

Cell volume regulation in the perfused liver of a freshwater air ...

Indian Academy of Sciences (India)

Madhu

that hypo- and hyper-osmolarity caused transient efflux (5.68 ± 0.38 µmol/g liver) and uptake (6.38 ± 0.45 µmol/g liver) of taurine ... flowing, stagnant and polluted water bodies of ponds, lakes ... dehydration arising out of such extreme environmental situations. Thus ... of 28 ± 2ºC in plastic aquaria with 12 h:12 h light and.

Value of liver elastography and abdominal ultrasound for detection of complications of allogeneic hemopoietic SCT.

Science.gov (United States)

Karlas, T; Weber, J; Nehring, C; Kronenberger, R; Tenckhoff, H; Mössner, J; Niederwieser, D; Tröltzsch, M; Lange, T; Keim, V

2014-06-01

Hepatic complications contribute to morbidity and mortality after allogeneic hemopoietic SCT. Liver Doppler ultrasound and elastography represent promising methods for pretransplant risk assessment and early detection of complications. Ultrasound (liver and spleen size, liver perfusion) and elastography (transient elastography (TE); right liver lobe acoustic radiation force impulse imaging (r-ARFI); left liver lobe ARFI (l-ARFI)) were prospectively evaluated in patients with indications for allo-SCT. Measurements were performed before and repeatedly after SCT. Results were compared with the incidence of life-threatening complications and death during the first 150 days after SCT. Of 59 included patients, 16 suffered from major complications and 9 of them died within the follow-up period. At baseline, liver and spleen size, liver perfusion, TE and r-ARFI did not differ significantly between patients with and without severe complications. In contrast, l-ARFI was significantly elevated in patients who later developed severe complications (1.58±0.30 m/s vs 1.37±0.27 m/s, P=0.030). After SCT, l-ARFI values remained elevated and TE showed increasing liver stiffness in patients with complications. The value of conventional liver ultrasound for prediction of severe SCT complications is limited. Increased values for TE and l-ARFI are associated with severe SCT complications and demand further evaluation.

Results of a Randomized Controlled Multicenter Phase III Trial of Percutaneous Hepatic Perfusion Compared with Best Available Care for Patients with Melanoma Liver Metastases.

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Hughes, Marybeth S; Zager, Jonathan; Faries, Mark; Alexander, H Richard; Royal, Richard E; Wood, Bradford; Choi, Junsung; McCluskey, Kevin; Whitman, Eric; Agarwala, Sanjiv; Siskin, Gary; Nutting, Charles; Toomey, Mary Ann; Webb, Carole; Beresnev, Tatiana; Pingpank, James F

2016-04-01

There is no consensus for the treatment of melanoma metastatic to the liver. Percutaneous hepatic perfusion with melphalan (PHP-Mel) is a method of delivering regional chemotherapy selectively to the liver. In this study, we report the results of a multicenter, randomized controlled trial comparing PHP-Mel with best alternative care (BAC) for patients with ocular or cutaneous melanoma metastatic to the liver. A total of 93 patients were randomized to PHP-Mel (n = 44) or BAC (n = 49). On the PHP-Mel arm, melphalan was delivered via the hepatic artery, and the hepatic effluent captured and filtered extracorporeally prior to return to the systemic circulation via a venovenous bypass circuit. PHP-Mel was repeatable every 4-8 weeks. The primary endpoint was hepatic progression-free survival (hPFS), and secondary endpoints included overall PFS (oPFS), overall survival (OS), hepatic objective response (hOR), and safety. hPFS was 7.0 months for PHP-Mel and 1.6 months for BAC (p PHP-Mel and 1.6 months for BAC (p PHP-Mel 10.6 months vs. BAC 10.0 months), likely due to crossover to PHP-Mel treatment (57.1 %) from the BAC arm, and the hOR was 36.4 % for PHP-Mel and 2.0 % for BAC (p PHP-Mel, three in the primary PHP-Mel group, and one post-crossover to PHP-Mel from BAC. This randomized, phase III study demonstrated the efficacy of the PHP-Mel procedure. hPFS, oPFS, and hOR were significantly improved with PHP-Mel. PHP with melphalan should provide a new treatment option for unresectable metastatic melanoma in the liver.

Fluorescence spectroscopy for assessment of liver transplantation grafts concerning graft viability and patient survival

Science.gov (United States)

Vollet Filho, José D.; da Silveira, Marina R.; Castro-e-Silva, Orlando; Bagnato, Vanderlei S.; Kurachi, Cristina

2015-06-01

Evaluating transplantation grafts at harvest is essential for its success. Laser-induced fluorescence spectroscopy (LIFS) can help monitoring changes in metabolic/structural conditions of tissue during transplantation. The aim of the present study is to correlate LIFSobtained spectra of human hepatic grafts during liver transplantation with post-operative patients' mortality rate and biochemical parameters, establishing a method to exclude nonviable grafts before implantation. Orthotopic liver transplantation, piggyback technique was performed in 15 patients. LIFS was performed under 408nm excitation. Collection was performed immediately after opening donor's abdominal cavity, after cold perfusion, end of back-table period, and 5 min and 1 h after warm perfusion at recipient. Fluorescence information was compared to lactate, creatinine, bilirubin and INR levels and to survival status. LIFS was sensitive to liver changes during transplantation stages. Study-in-progress; initial results indicate correlation between fluorescence and life/death status of patients.

Comparison between acoustic radiation force impulse quantification data and perfusion-CT parameters in hepatocellular carcinoma

Energy Technology Data Exchange (ETDEWEB)

Esser, Michael, E-mail: michael.esser@med.uni-tuebingen.de; Schneeweiß, Sven, E-mail: sven.schneeweiss@med.uni-tuebingen.de; Kolb, Manuel, E-mail: manuel.kolb@med.uni-tuebingen.de; Kurucay, Mustafa, E-mail: mustafa.kurucay@med.uni-tuebingen.de; Ruff, Christer, E-mail: christer.ruff@med.uni-tuebingen.de; Nikolaou, Konstantin, E-mail: konstantin.nikolaou@med.uni-tuebingen.de; Horger, Marius, E-mail: marius.horger@med.uni-tuebingen.de

2017-04-15

Highlights: • HCC tissue stiffness did not correlate with the degree of tumor vascularization. • HCC tissue stiffness declined while increasing HCC distance to the skin surface. • HCC tissue stiffness showed higher values the larger the respective tumor was. • Poorly differentiated HCCs showed increased values of tumor tissue stiffness. - Abstract: Objective: To find out, if ultrasound elastography of hepatocellular carcinoma (HCC) can predict patterns of tumor perfusion in volume perfusion computed tomography (VPCT). Material and methods: 25 consecutive patients (mean age, 68.9; range, 51–85 years) with liver cirrhosis suspected of HCC underwent VPCT and acoustic radiation force impulse (ARFI) elastography the same day. Quantitative elasticity values were registered, while blood flow (BF), blood volume (BV) and hepatic perfusion index (HPI) of the HCC lesions were calculated. Additionally, we identified histologic WHO grading, lesion size and localization. The Siemens Acuson S 3000 HELX-System with Virtual Touch™-Software and Siemens Somatom Definition Flash with Syngo{sup ®} software were used. Results: A total of 43 HCC lesions were assessed. Mean shear wave velocity was 2.6 m/s (range, 1.1–4.3 m/s). There was no significant linear correlation between the elasticity values and BF (p = 0.751), BV (p = 0.426) and HPI (p = 0.437). However, elasticity values were higher, the larger the tumor was (p = 0.008). Shear wave velocity declined with increasing distance of the HCC to the skin surface (p = 0.028) and depending on liver segment. In addition, elasticity values were higher in less differentiated HCCs. This trend was not statistically significant (p = 0.842). Conclusion: Tissue elasticity in HCC does not correlate with the degree of tumor vascularization, but calculated values are influenced both by the tumor size and localization inside the liver.

Isolation of Kupffer Cells and Hepatocytes from a Single Mouse Liver

DEFF Research Database (Denmark)

Aparicio-Vergara, Marcela; Tencerova, Michaela; Morgantini, Cecilia

2017-01-01

Liver perfusion is a common technique used to isolate parenchymal and non-parenchymal liver cells for in vitro experiments. This method allows hepatic cells to be separated based on their size and weight, by centrifugation using a density gradient. To date, other methods allow the isolation of only...... one viable hepatic cellular fraction from a single mouse; either parenchymal (hepatocytes) or non-parenchymal cells (i.e., Kupffer cells or hepatic stellate cells). Here, we describe a method to isolate both hepatocytes and Kupffer cells from a single mouse liver, thereby providing the unique...... advantage of studying different liver cell types that have been isolated from the same organism....

Comparison of Intrahepatic and Pancreatic Perfusion on Fusion Images Using a Combined SPECT/CT System and Assessment of Efficacy of Combined Continuous Arterial Infusion and Systemic Chemotherapy in Advanced Pancreatic Carcinoma

International Nuclear Information System (INIS)

Ikeda, Osama; Tamura, Yoshitaka; Nakasone, Yutaka; Shiraishi, Shinya; Kawanaka, Kouichi; Tomiguchi, Seiji; Yamashita, Yasuyuki; Takamori, Hiroshi; Kanemitsu, Keiichiro; Baba, Hideo

2007-01-01

Purpose. The purpose of this study was to compare intrahepatic and pancreatic perfusion on fusion images using a combined single-photon emission computed tomography (SPECT)/CT system and to evaluate the efficacy of combined continuous transcatheter arterial infusion (CTAI) and systemic chemotherapy in the treatment of advanced pancreatic carcinoma. Materials and Methods. CTAI was performed in 33 patients (22 men, 11 women; age range, 35-77 years; mean age, 60 years) with stage IV pancreatic cancer with liver metastasis. The reservoir was transcutaneously implanted with the help of angiography. The systemic administration of gemcitabine was combined with the infusion of 5-fluorouracil via the reservoir. In all patients we obtained fusion images using a combined SPECT/CT system. Pancreatic perfusion on fusion images was classified as perfusion presence or as perfusion absent in the pancreatic cancer. Using WHO criteria we recorded the tumor response after 3 months on multislice helical CT scans. Treatment effects were evaluated based on the pancreatic cancer, liver metastasis, and factors such as intrahepatic and pancreatic perfusion on fusion images. For statistical analysis we used the chi-square test; survival was evaluated by the Kaplan Meier method (log-rank test). Results. On fusion images, pancreatic and intrahepatic perfusion was recorded as hot spot and as homogeneous distribution, respectively, in 18 patients (55%) and as cold spot and heterogeneous distribution, respectively, in 15 (45%). Patients with hot spot in the pancreatic tumor and homogeneous distribution in the liver manifested better treatment results (p < 0.05 and p < 0.01, respectively). Patients with hot spot both in the pancreatic cancer and in the liver survived longer than those with cold spot in the pancreatic cancer and heterogeneous distribution in the liver (median ± SD, 16.0 ± 3.7 vs. 8.0 ± 1.4 months; p < 0.05). Conclusions. We conclude that in patients with advanced pancreatic

Radiofrequency ablation combined with transcatheter arterial embolisation in rabbit liver: investigation of the ablation zone according to the time interval between the two therapies.

Science.gov (United States)

Lee, I J; Kim, Y I; Kim, K W; Kim, D H; Ryoo, I; Lee, M W; Chung, J W

2012-11-01

This study was designed to evaluate the extent of the radiofrequency ablation zone in relation to the time interval between transcatheter arterial embolisation (TAE) and radiofrequency ablation (RFA) and, ultimately, to determine the optimal strategy of combining these two therapies for hepatocellular carcinoma. 15 rabbits were evenly divided into three groups: Group A was treated with RFA alone; Group B was treated with TAE immediately followed by RFA; and Group C was treated with TAE followed by RFA 5 days later. All animals underwent perfusion CT (PCT) scans immediately after RFA. Serum liver transaminases were measured to evaluate acute liver damage. Animals were euthanised for pathological analysis of ablated tissues 10 days after RFA. Non-parametric analyses were conducted to compare PCT indices, the RFA zone and liver transaminase levels among the three experimental groups. Group B showed a significantly larger ablation zone than the other two groups. Arterial liver perfusion and hepatic perfusion index represented well the perfusion decrease after TAE on PCT. Although Group B showed the most elevated liver transaminase levels at 1 day post RFA, the enzymes decreased to levels that were not different from the other groups at 10 days post-RFA. When combined TAE and RFA therapy is considered, TAE should be followed by RFA as quickly as possible, as it can be performed safely without serious hepatic deterioration, despite the short interval between the two procedures.

Effects of registration error on parametric response map analysis: a simulation study using liver CT-perfusion images

International Nuclear Information System (INIS)

Lausch, A; Lee, T Y; Wong, E; Jensen, N K G; Chen, J; Lock, M

2014-01-01

Purpose: To investigate the effects of registration error (RE) on parametric response map (PRM) analysis of pre and post-radiotherapy (RT) functional images. Methods: Arterial blood flow maps (ABF) were generated from the CT-perfusion scans of 5 patients with hepatocellular carcinoma. ABF values within each patient map were modified to produce seven new ABF maps simulating 7 distinct post-RT functional change scenarios. Ground truth PRMs were generated for each patient by comparing the simulated and original ABF maps. Each simulated ABF map was then deformed by different magnitudes of realistic respiratory motion in order to simulate RE. PRMs were generated for each of the deformed maps and then compared to the ground truth PRMs to produce estimates of RE-induced misclassification. Main findings: The percentage of voxels misclassified as decreasing, no change, and increasing, increased with RE For all patients, increasing RE was observed to increase the number of high post-RT ABF voxels associated with low pre-RT ABF voxels and vice versa. 3 mm of average tumour RE resulted in 18-45% tumour voxel misclassification rates. Conclusions: RE induced misclassification posed challenges for PRM analysis in the liver where registration accuracy tends to be lower. Quantitative understanding of the sensitivity of the PRM method to registration error is required if PRMs are to be used to guide radiation therapy dose painting techniques.

(Pyridoxylated hemoglobin)-(polyoxyethylene) conjugate solution as blood substitute for normothermic whole body rinse-out.

Science.gov (United States)

Agishi, T; Funakoshi, Y; Honda, H; Yamagata, K; Kobayashi, M; Takahashi, M

1988-01-01

In order to investigate a new possibility for artificial blood with oxygen-carrying capability to be applied to other than mere supplementation, normothermic whole body rinse-out in which artificial blood deriving from perfluorochemical emulsion, Fluosol-DA 20% (Green Cross Co., Ltd., Osaka, Japan) or stabilized hemoglobin solution, (pyridoxylated hemoglobin)-(polyoxyethylene) conjugate solution (Ajinomoto Co., Ltd., Tokyo, Japan) were used as rinsing fluid for a blood purification experiment. Replacement either with approximately 150 ml/kg of Fluosol-DA or stabilized hemoglobin solution showed effective removal of digoxin at a reduction rate of 96.3% or 92.2%, respectively. However, when Fluosol-DA was used, a certain amount of perfluorochemical should be retrieved by centrifugation to avoid a possible toxic effect on the reticulo-endothelial system. Even though 3 out of 6, and 3 out of 8 dogs, respectively, survived for a long period after the procedure, the experimental dogs were very susceptible to infection.

Emerging concepts in liver graft preservation

Science.gov (United States)

Bejaoui, Mohamed; Pantazi, Eirini; Folch-Puy, Emma; Baptista, Pedro M; García-Gil, Agustín; Adam, René; Roselló-Catafau, Joan

2015-01-01

The urgent need to expand the donor pool in order to attend to the growing demand for liver transplantation has obliged physicians to consider the use of suboptimal liver grafts and also to redefine the preservation strategies. This review examines the different methods of liver graft preservation, focusing on the latest advances in both static cold storage and machine perfusion (MP). The new strategies for static cold storage are mainly designed to increase the fatty liver graft preservation via the supplementation of commercial organ preservation solutions with additives. In this paper we stress the importance of carrying out effective graft washout after static cold preservation, and present a detailed discussion of the future perspectives for dynamic graft preservation using MP at different temperatures (hypothermia at 4 °C, normothermia at 37 °C and subnormothermia at 20 °C-25 °C). Finally, we highlight some emerging applications of regenerative medicine in liver graft preservation. In conclusion, this review discusses the “state of the art” and future perspectives in static and dynamic liver graft preservation in order to improve graft viability. PMID:25593455

Perfusion abnormalities in congenital and neoplastic pulmonary disease: comparison of MR perfusion and multislice CT imaging

International Nuclear Information System (INIS)

Boll, Daniel T.; Lewin, Jonathan S.; Young, Philip; Gilkeson, Robert C.; Siwik, Ernest S.

2005-01-01

The aim of this work was to assess magnetic resonance (MR) perfusion patterns of chronic, nonembolic pulmonary diseases of congenital and neoplastic origin and to compare the findings with results obtained with pulmonary, contrast-enhanced multislice computed tomography (CT) imaging to prove that congenital and neoplastic pulmonary conditions require MR imaging over the pulmonary perfusion cycle to successfully and directly detect changes in lung perfusion patterns. Twenty-five patients underwent concurrent CT and MR evaluation of chronic pulmonary diseases of congenital (n=15) or neoplastic (n=10) origin. Analysis of MR perfusion and contrast-enhanced CT datasets was realized by defining pulmonary and vascular regions of interest in corresponding positions. MR perfusion calculated time-to-peak enhancement, maximal enhancement and the area under the perfusion curve. CT datasets provided pulmonary signal-to-noise ratio measurements. Vessel centerlines of bronchial arteries were determined. Underlying perfusion type, such as pulmonary arterial or systemic arterial supply, as well as regions with significant variations in perfusion were determined statistically. Analysis of the pulmonary perfusion pattern detected pulmonary arterial supply in 19 patients; six patients showed systemic arterial supply. In pulmonary arterial perfusion, MR and multislice CT imaging consistently detected the perfusion type and regions with altered perfusion patterns. In bronchial arterial supply, MR perfusion and CT imaging showed significant perfusion differences. Patients with bronchial arterial supply had bronchial arteries ranging from 2.0 to 3.6 mm compared with submillimeter diameters in pulmonary arterial perfusion. Dynamic MR imaging of congenital and neoplastic pulmonary conditions allowed characterization of the pulmonary perfusion type. CT imaging suggested the presence of systemic arterial perfusion by visualizing hypertrophied bronchial arteries. (orig.)

Value of magnetic resonance imaging in diffuse liver diseases; Stellenwert der MRT bei diffusen Lebererkrankungen

Energy Technology Data Exchange (ETDEWEB)

Schramm, N.; D' Anastasi, M.; Reiser, M.F.; Zech, C.J. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany)

2012-08-15

Diffuse liver diseases show an increasing prevalence. The diagnostic gold standard of liver biopsy has several disadvantages. There is a clinical demand for non-invasive imaging-based techniques to qualitatively and quantitatively evaluate the entire liver. Ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) are routinely used. Steatosis: chemical shift and frequency selective imaging, MR spectroscopy (MRS). Hemochromatosis: MR-based iron quantification. Fibrosis: MR elastography, diffusion, intravoxel incoherent motion (IVIM) and MR perfusion. T1-weighted in and opposed phase imaging is the clinically most frequently used MR technique to noninvasively detect and quantify steatosis. New methods for quantification that are not influenced by confounders like iron overload are under investigation. The most sensitive method to measure the fat content of the liver is MRS. As data acquisition and analysis remain complex and there is no whole organ coverage, MRS of the liver is not a routine method. With an optimized protocol incorporating T2* sequences, MRI is the modality of choice to quantify iron overload in hemochromatosis. Standard MR sequences cannot depict early stages of liver fibrosis. Advanced MR techniques (e.g. elastography, diffusion, IVIM and perfusion) for noninvasive assessment of liver fibrosis appear promising but their role has to be further investigated. (orig.) [German] Die Praevalenz diffuser Lebererkrankungen nimmt zu. Der klinische Goldstandard, die Leberbiopsie, hat zahlreiche Nachteile. Es besteht ein Bedarf an bildgebenden Verfahren zur nichtinvasiven qualitativen und quantitativen Beurteilung der gesamten Leber bei diesen Erkrankungen. Hier sind Ultraschall, CT und MRT zu nennen. Steatosis: Chemical-shift- und frequenzselektive Bildgebung, MR-Spektroskopie (MRS) zur Fettquantifizierung. Haemochromatose: MR-basierte Eisenquantifizierung. Fibrose: MR-Elastographie, Diffusion, ''intravoxel incoherent motion

Selective Cerebro-Myocardial Perfusion in Complex Neonatal Aortic Arch Pathology: Midterm Results.

Science.gov (United States)

Hoxha, Stiljan; Abbasciano, Riccardo Giuseppe; Sandrini, Camilla; Rossetti, Lucia; Menon, Tiziano; Barozzi, Luca; Linardi, Daniele; Rungatscher, Alessio; Faggian, Giuseppe; Luciani, Giovanni Battista

2018-04-01

Aortic arch repair in newborns and infants has traditionally been accomplished using a period of deep hypothermic circulatory arrest. To reduce neurologic and cardiac dysfunction related to circulatory arrest and myocardial ischemia during complex aortic arch surgery, an alternative and novel strategy for cerebro-myocardial protection was recently developed, where regional low-flow perfusion is combined with controlled and independent coronary perfusion. The aim of the present retrospective study was to assess short-term and mid-term results of selective and independent cerebro-myocardial perfusion in neonatal aortic arch surgery. From April 2008 to August 2015, 28 consecutive neonates underwent aortic arch surgery under cerebro-myocardial perfusion. There were 17 male and 11 female, with median age of 15 days (3-30 days) and median body weight of 3 kg (1.6-4.2 kg), 9 (32%) of whom with low body weight (cerebro-myocardial perfusion was 30 ± 11 min (15-69 min). Renal dysfunction, requiring a period of peritoneal dialysis was observed in 10 (36%) patients, while liver dysfunction was noted only in 3 (11%). There were three (11%) early and two late deaths during a median follow-up of 2.9 years (range 6 months-7.7 years), with an actuarial survival of 82% at 7 years. At latest follow-up, no patient showed signs of cardiac or neurologic dysfunction. The present experience shows that a strategy of selective and independent cerebro-myocardial perfusion is safe, versatile, and feasible in high-risk neonates with complex congenital arch pathology. Encouraging outcomes were noted in terms of cardiac and neurological function, with limited end-organ morbidity. © 2018 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Calcium signaling in liver.

Science.gov (United States)

Gaspers, Lawrence D; Thomas, Andrew P

2005-01-01

In hepatocytes, hormones linked to the formation of the second messenger inositol 1,4,5-trisphosphate (InsP3) evoke transient increases or spikes in cytosolic free calcium ([Ca2+]i), that increase in frequency with the agonist concentration. These oscillatory Ca2+ signals are thought to transmit the information encoded in the extracellular stimulus to down-stream Ca2+-sensitive metabolic processes. We have utilized both confocal and wide field fluorescence microscopy techniques to study the InsP3-dependent signaling pathway at the cellular and subcellular levels in the intact perfused liver. Typically InsP3-dependent [Ca2+]i spikes manifest as Ca2+ waves that propagate throughout the entire cytoplasm and nucleus, and in the intact liver these [Ca2+]i increases are conveyed through gap junctions to encompass entire lobular units. The translobular movement of Ca2+ provides a means to coordinate the function of metabolic zones of the lobule and thus, liver function. In this article, we describe the characteristics of agonist-evoked [Ca2+]i signals in the liver and discuss possible mechanisms to explain the propagation of intercellular Ca2+ waves in the intact organ.

Dexmedetomidine Increases Tau Phosphorylation Under Normothermic Conditions In Vivo and In Vitro

Science.gov (United States)

Whittington, Robert A.; Virág, László; Gratuze, Maud; Petry, Franck R.; Noël, Anastasia; Poitras, Isabelle; Truchetti, Geoffrey; Marcouiller, François; Papon, Marie-Amélie; Khoury, Noura El; Wong, Kevin; Bretteville, Alexis; Morin, Françoise; Planel, Emmanuel

2015-01-01

There is developing interest in the potential association between anesthesia and the onset and progression of Alzheimer's disease. Several anesthetics have thus been demonstrated to induce tau hyperphosphorylation, an effect mostly mediated by anesthesia-induced hypothermia. Here, we tested the hypothesis that acute normothermic administration of dexmedetomidine, an intravenous sedative used in intensive care units, would result in tau hyperphosphorylation in vivo and in vitro. When administered to non-transgenic mice, dexmedetomidine induced tau hyperphosphorylation persisting up to 6h in the hippocampus for the AT8 epitope. Pretreatment with atipamezole, a highly specific α2-adrenergic receptor (α2-AR) antagonist, blocked dexmedetomidine-induced tau hyperphosphorylation. Furthermore, dexmedetomidine dose-dependently increased tau phosphorylation at AT8 in SH-SY5Y cells, impaired mice spatial memory in the Barnes maze, and promoted tau hyperphosphorylation and aggregation in transgenic hTau mice. These findings suggest that dexmedetomidine: i) increases tau phosphorylation, in vivo and in vitro, in the absence of anesthetic-induced hypothermia and through α2-AR activation, ii) promotes tau aggregation in a mouse model of tauopathy, and iii) impacts spatial reference memory. PMID:26058840

Uptake and metabolism of polymerized albumin by rat liver. Role of the scavenger receptor

International Nuclear Information System (INIS)

Wright, T.L.; Roll, F.J.; Jones, A.L.; Weisiger, R.A.

1988-01-01

Hepatitis B virus binds avidly to albumin polymers, which in turn may mediate viral attachment to liver cells. This hypothesis is critically dependent on prior results obtained using glutaraldehyde-polymerized human serum albumin as a model for naturally occurring albumin species. We used the perfused rat liver to characterize the uptake, cellular distribution, and metabolism of glutaraldehyde-polymerized human albumin. 125 I-glutaraldehyde-polymerized human albumin was efficiently removed from the perfusate by the liver (29% extraction). However, few autoradiographic grains were located over hepatic parenchymal cells (6%). Instead, most glutaraldehyde-polymerized human albumin appeared to be removed by endothelial (59%) or Kupffer (31%) cells. Hepatic uptake was strongly inhibited by formaldehyde-treated monomeric albumin, a known ligand of the endothelial scavenger receptor for chemically modified proteins. After uptake, most glutaraldehyde-polymerized human albumin was rapidly degraded and released into the perfusate (74% within 60 min). This process was blocked by chloroquine and leupeptin, suggesting that it involves lysosomal acid hydrolases. We conclude that glutaraldehyde-polymerized albumin is efficiently cleared and degraded by the endothelial scavenger pathway. Glutaraldehyde-polymerized albumin therefore appears to be a poor model for predicting the hepatic handling of naturally occurring albumin species bound to hepatitis B virions. Even if viral particles were to follow this pathway, few would enter parenchymal hepatocytes

Laser doppler perfusion imaging

International Nuclear Information System (INIS)

Waardell, K.

1992-01-01

Recording of tissue perfusion is important in assessing the influence of peripheral vascular diseases on the microcirculation. This thesis reports on a laser doppler perfusion imager based on dynamic light scattering in tissue. When a low power He-Ne laser beam sequentally scans the tissue, moving blood cells generate doppler components in the back-scattered light. A fraction of this light is detected by a photodetector and converted into an electrical signal. In the processor, a signal proportional to the tissue perfusion at each measurement site is calculated and stored. When the scanning procedure is completed, a color-coded perfusion image is presented on a monitor. To convert important aspects of the perfusion image into more quantitative parameters, data analysis functions are implemented in the software. A theory describing the dependence of the distance between individual measurement points and detector on the system amplification factor is proposed and correction algorithms are presented. The performance of the laser doppler perfusion imager was evaluated using a flow simulator. A linear relationship between processor output signal and flow through the simulator was demonstrated for blood cell concentrations below 0.2%. The median sampling depth of the laser beam was simulated by a Monte Carlo technique and estimated to 235 μm. The perfusion imager has been used in the clinic to study perfusion changes in port wine stains treated with argon laser and to investigate the intensity and extension of the cutaneous axon reflex response after electrical nerve stimulation. The fact that perfusion can be visualized without touching the tissue implies elimination of sterilization problems, thus simplifying clinical investigations of perfusion in association with diagnosis and treatment of peripheral vascular diseases. 22 refs

Dynamic CT of portal hypertensive gastropathy: significance of transient gastric perfusion defect sign

International Nuclear Information System (INIS)

Kim, T.U.; Kim, S.; Woo, S.K.; Lee, J.W.; Lee, T.H.; Jeong, Y.J.; Heo, J.

2008-01-01

Aim: To evaluate the 'transient gastric perfusion defect' sign as a way of diagnosing portal hypertensive gastropathy (PHG) on multidetector computed tomography (CT). Materials and methods: Ninety-two consecutive patients with cirrhosis underwent three-phase CT and endoscopy. Endoscopy was performed within 3 days of the CT examination. As controls, 92 patients without clinical evidence of chronic liver diseases who underwent CT and endoscopy were enrolled; the findings at endoscopy were used as a reference standard for patients with PHG. Two radiologists who were unaware of the results of the endoscopy retrospectively interpreted the CT images. PHG was diagnosed on dynamic CT if the transient gastric perfusion defect sign was present. The transient gastric perfusion defect was defined as the presence of transient, segmental or subsegmental hypo-attenuating mucosa in the fundus or body of the stomach on hepatic arterial imaging that returned to normal attenuation on portal venous or equilibrium-phase imaging. The frequency of the transient gastric perfusion defect sign was compared between these two groups using Fisher's exact test. The frequency, sensitivity, specificity, positive predictive values, and negative predictive values of the transient gastric perfusion defect sign were also compared between patients with PHG and without PHG in the cirrhosis group. Results: Nine patients of 92 patients with cirrhosis were excluded because of previous procedure or motion artifact; the remaining 83 patients with cirrhosis were evaluated. In the cirrhosis group, 40 (48.1%) of 83 patients showed the transient gastric perfusion defect sign. In the control group, none of the 92 patients showed the transient gastric perfusion defect sign. In the cirrhotic group, the frequency of the transient gastric perfusion defect sign was significantly higher in the patients with PHG (75%, 36/48) than in patients without PHG (11.4%, 4/35). The sensitivity, specificity, positive predictive

The influence of tryptophan on gluconeogenesis in the perfused liver of irradiated rats

International Nuclear Information System (INIS)

Borovikova, G.V.; Mashkova, N.Yu.; Dokshina, G.A.

1985-01-01

The liver isolated at different times after exposure to 7 Gy radiation responded in a different way to the effect of tryptophan (0.75 g/l) used as a gluconeogenesis inhibitor. While 24 h after irradiation of the addition of tryptophan inhibited gluconeogenesis from circulating exogenous amino acids, in 3 days, on the contrary, gluconeogenesis in the liver of donors was enhanced. It is suggested that these effects of tryptophan are associated with different functional status of the liver during the postirradiation observation period

Development of analytical methods for the gas chromatographic determination of 1,2-epoxy-3-butene, 1,2:3,4-diepoxybutane, 3-butene-1,2-diol, 3,4-epoxybutane-1,2-diol and crotonaldehyde from perfusate samples of 1,3-butadiene exposed isolated mouse and rat livers

Energy Technology Data Exchange (ETDEWEB)

Bhowmik, S.; Schuster, A.; Filser, J.G.

2003-07-01

Mutagenicity and carcinogenicity of 1,3-butadiene (BD) highly probably results from epoxide metabolites as 1,2-epoxy-3-butene (EB), 1,2:3,4-diepoxybutane (DEB) and 3,4-epoxybutane-1,2-diol (EBD). A further metabolite crotonaldehyde (CA) has also been discussed to be relevant. So far, in BD exposed rodents only EB and DEB concentrations had been quantified. However, the methods used were either not very sensitive or instrumentally expensive. Therefore, the goal of the present work was to establish simple analytical methods selective and sensitive enough to determine all of these compounds and a further secondary BD intermediate, 3-butene-1,2-diol (B-diol), in BD exposed rodent livers. The once-through perfused liver system was chosen for testing the applicability of the methods to be developed, since it enables BD exposures of this quantitatively most relevant metabolising organ near to the in-vivo situation. All the metabolites were extracted from the aqueous perfusion medium and analysed using a gas chromatograph equipped with a mass selective detector (GC/MS) in the PCI mode. (orig.)

The effects of somatostatin and ursodeoxycholic acid in preventing the ischemic injury of the liver following Pringle maneuver in obstructive jaundice-rat model.

Science.gov (United States)

Pergel, Ahmet; Zengin, Kagan; Cercel, Ali; Aki, Hilal; Kaya, Safiye

2007-01-01

In our study, the effects of somatostatin (SS) and ursodeoxycholic acid (UDCA) on ischemic liver injury were studied in (obstructive) jaundice-rat model. For this purpose, jaundice was produced in the first four groups by binding of their choleducts. We performed just laparotomy to the other four groups of animals. To groups 1 and 5, SS was given 15 mcg/kg/day intraperitoneally, and to groups 2 and 6, UDCA was given 20 mg/kg/day enterally. No drugs were given to any other group. At the end of one week, a procedure with ischemia of the liver for 60 minutes followed by reperfusion for 2 hours, was performed to each rat except for groups 4 and 8. Following this procedure, they were sacrificed. The blood samples were taken to measure SGOT, SGPT, ALP, LDH, total and direct bilirubin levels, while liver biopsies were taken for histopathological evaluation. Under normothermic conditions, following 60-minute liver ischemia period, no irreversible histopathological changes were detected. However, increases in liver necrosis parameters were noted biochemically. SS and UDCA were thought to be effective in preventing the injury by decreasing the liver enzymes levels to a significant degree. The damage of the hepatic ischemic injury was found to be more meaningful and prominent in liver with jaundice. In this study, it was noted that SS and UDCA decrease the effects of cholestatic hepatic injury especially and improve the condition.

Abnormal perfusion on myocardial perfusion SPECT in patients with Wolff-Parkinson-White syndrome

International Nuclear Information System (INIS)

Kang, Do Young; Cha, Kwang Soo; Han, Seung Ho; Park, Tae Ho; Kim, Moo Hyun; Kim, Young Dae

2005-01-01

Abnormal myocardial perfusion may be caused by ventricular preexcitation, but its location, extent, severity and correlation with accessory pathway (AP) are not established. We evaluated perfusion patterns on myocardial perfusion SPECT and location of AP in patients with WPW (Wolff-Parkison-White) syndrome. Adenosine Tc-99m MIBI or Tl-201 myocardial perfusion SPECT was performed in 11 patients with WPW syndrome. Perfusion defects (PD) were compared to AP location based on ECT with Fitzpatrick's algorithm of electrophysiologic study and radiofrequency catheter ablation. Patients had atypical chest discomfort or no symptom. Risk of coronary artery disease (CAD) was below 0.1 in 11 patients using the nomogram to estimate the probability of CAD. Coronary angiography was performed in 4 patients(mid-LAD 50% in one, normal in others). In 4 patients, AP localization was done by electrophysiologic study and radiofrequency catheter ablation (RFCA). Small to large extent (11.0 ± 8.5%, range:3 ∼ 35%) and mild to moderate severity (-71 ± 42.7%, range:-217 ∼ -39%) of reversible (n=9) or fixed (n=1) perfusion defects were noted. One patients with right free wall (right lateral) AP showed normal. PD locations were variable following the location of AP. One patient with left lateral wall AP was followed 6 weeks after RFCA and showed significantly decreased PD on SPECT with successful ablation. Myocardial perfusion defect showed variable extent, severity and location in patients with WPW syndrome. Abnormal perfusion defect showed in most of all patients, but if did not seem to be correlated specifically with location of accessory pathway and coronary artery disease. Therefore myocardial perfusion SPECT should be interpreted carefully in patients with WPW syndrome

Abnormal perfusion on myocardial perfusion SPECT in patients with Wolff-Parkinson-White syndrome

Energy Technology Data Exchange (ETDEWEB)

Kang, Do Young; Cha, Kwang Soo; Han, Seung Ho; Park, Tae Ho; Kim, Moo Hyun; Kim, Young Dae [Donga University College of Medicine, Busan (Korea, Republic of)

2005-02-15

Abnormal myocardial perfusion may be caused by ventricular preexcitation, but its location, extent, severity and correlation with accessory pathway (AP) are not established. We evaluated perfusion patterns on myocardial perfusion SPECT and location of AP in patients with WPW (Wolff-Parkison-White) syndrome. Adenosine Tc-99m MIBI or Tl-201 myocardial perfusion SPECT was performed in 11 patients with WPW syndrome. Perfusion defects (PD) were compared to AP location based on ECT with Fitzpatrick's algorithm of electrophysiologic study and radiofrequency catheter ablation. Patients had atypical chest discomfort or no symptom. Risk of coronary artery disease (CAD) was below 0.1 in 11 patients using the nomogram to estimate the probability of CAD. Coronary angiography was performed in 4 patients(mid-LAD 50% in one, normal in others). In 4 patients, AP localization was done by electrophysiologic study and radiofrequency catheter ablation (RFCA). Small to large extent (11.0 {+-} 8.5%, range:3 {approx} 35%) and mild to moderate severity (-71 {+-} 42.7%, range:-217 {approx} -39%) of reversible (n=9) or fixed (n=1) perfusion defects were noted. One patients with right free wall (right lateral) AP showed normal. PD locations were variable following the location of AP. One patient with left lateral wall AP was followed 6 weeks after RFCA and showed significantly decreased PD on SPECT with successful ablation. Myocardial perfusion defect showed variable extent, severity and location in patients with WPW syndrome. Abnormal perfusion defect showed in most of all patients, but if did not seem to be correlated specifically with location of accessory pathway and coronary artery disease. Therefore myocardial perfusion SPECT should be interpreted carefully in patients with WPW syndrome.

Hemostatic mechanism underlying microbubble-enhanced non-focused ultrasound in the treatment of a rabbit liver trauma model

Science.gov (United States)

Zhao, Da-wei; Tian, Meng; Yang, Jian-zheng; Du, Peng; Bi, Jie; Zhu, Xinjian

2016-01-01

The aim of our study was to investigate the hemostatic mechanism underlying microbubble-enhanced non-focused ultrasound treatment of liver trauma. Thirty rabbits with liver trauma were randomly divided into three groups—the microbubble-enhanced ultrasound (MEUS; further subdivided based on exposure intensity into MEUS1 [0.11 W/cm2], MEUS2 [0.55 W/cm2], and MEUS3 [1.1 W/cm2]), ultrasound without microbubbles (US), and microbubbles without ultrasound (MB) groups. The pre- and post-treatment bleeding weight and visual bleeding scores were evaluated. The serum liver enzyme concentrations as well as the blood perfusion level represented by mean peak contrast intensity (PI) ratio in the treatment area were analyzed. The hemostatic mechanism was evaluated by histological and transmission electron microscopic examination of liver tissue samples. The MEUS subgroups 1–3 (grade 0–1, grade 0–2, and grade 1–2, respectively) exhibited significantly lower post-treatment visual bleeding scores than the US and MB groups (both, grade 3–4; all, P hepatic cells became edematous and compressed the hepatic sinus and associated blood vessels. However, the serum liver enzyme levels were not significantly altered. Microbubble-enhanced non-focused ultrasound does not significantly affect blood perfusion and liver function and can be used to induce rapid hemostasis in case of liver trauma. PMID:27633577

Saline-enhanced hepatic radiofrequency ablation using a perfused-cooled electrode: comparison of dual probe bipolar mode with monopolar and single probe bipolar modes

International Nuclear Information System (INIS)

Lee, Jeong Min; Han, Joon Koo; Kim, Se Hyung; Lee, Jae Young; Kim, Dae Jin; Lee, Min Woo; Cho, Gyung Goo; Han, Chang Jin; Choi, Byung Ihn

2004-01-01

To determine whether saline-enhanced dual probe bipolar radiofrequency ablation (RFA) using perfused-cooled electrodes shows better in-vitro efficiency than monopolar or single probe bipolar RFA in creating larger coagulation necrosis. RF was applied to excised bovine livers in both bipolar and monopolar modes using a 200W generator (CC-3; Radionics) and the perfused-cooled electrodes for 10 mins. After placing single or double perfused-cooled electrodes in the explanted liver, 30 ablation zones were created at three different regimens: group A; saline-enhanced monopolar RFA, group B; saline-enhanced single probe bipolar RFA, and group C; saline-enhanced dual probe bipolar RFA. During RFA, we measured the tissue temperature at 15mm from the electrode. The dimensions of the ablation zones and changes in the impedance currents and liver temperature during RFA were then compared between the groups. The mean current values were higher for monopolar mode (group A) than for the bipolar modes (group B and C): 1550 ± 25 mA in group A, 764 ±189 mA in group B and 819 ± 98 mA in group C(ρ 3 in group A, 23.7 ±3.8 cm 3 in group B, and 34.2 ± 5.1 cm 3 in group C(ρ 0.05). The temperature at 15 mm from the electrode was higher in group C than in the other groups: 70 ± 18 .deg. C in group A, 59 ± 23 .deg. C in group B and 96 ± 16 .deg. C in group C (ρ < 0.05). Saline-enhanced bipolar RFA using dual perfused-cooled electrodes increases the dimension of the ablation zone more efficiently than monopolar RFA or single probe bipolar RFA

Reverse ventilation--perfusion mismatch

International Nuclear Information System (INIS)

Palmaz, J.C.; Barnett, C.A.; Reich, S.B.; Krumpe, P.E.; Farrer, P.A.

1984-01-01

Patients having lobar airway obstruction or consolidation usually have decreases of both ventilation and perfusion on lung scans. We report three patients in whom hypoxic vasoconstriction was apparently incomplete, resulting in a ''reversed'' ventilation-perfusion mismatch. Perfusion of the hypoxic lobe on the radionuclide scan was associated with metabolic alkalosis, pulmonary venous and pulmonary arterial hypertension in these patients

Quantitative PET of liver functions.

Science.gov (United States)

Keiding, Susanne; Sørensen, Michael; Frisch, Kim; Gormsen, Lars C; Munk, Ole Lajord

2018-01-01

Improved understanding of liver physiology and pathophysiology is urgently needed to assist the choice of new and upcoming therapeutic modalities for patients with liver diseases. In this review, we focus on functional PET of the liver: 1) Dynamic PET with 2-deoxy-2-[ 18 F]fluoro- D -galactose ( 18 F-FDGal) provides quantitative images of the hepatic metabolic clearance K met (mL blood/min/mL liver tissue) of regional and whole-liver hepatic metabolic function. Standard-uptake-value ( SUV ) from a static liver 18 F-FDGal PET/CT scan can replace K met and is currently used clinically. 2) Dynamic liver PET/CT in humans with 11 C-palmitate and with the conjugated bile acid tracer [ N -methyl- 11 C]cholylsarcosine ( 11 C-CSar) can distinguish between individual intrahepatic transport steps in hepatic lipid metabolism and in hepatic transport of bile acid from blood to bile, respectively, showing diagnostic potential for individual patients. 3) Standard compartment analysis of dynamic PET data can lead to physiological inconsistencies, such as a unidirectional hepatic clearance of tracer from blood ( K 1 ; mL blood/min/mL liver tissue) greater than the hepatic blood perfusion. We developed a new microvascular compartment model with more physiology, by including tracer uptake into the hepatocytes from the blood flowing through the sinusoids, backflux from hepatocytes into the sinusoidal blood, and re-uptake along the sinusoidal path. Dynamic PET data include information on liver physiology which cannot be extracted using a standard compartment model. In conclusion , SUV of non-invasive static PET with 18 F-FDGal provides a clinically useful measurement of regional and whole-liver hepatic metabolic function. Secondly, assessment of individual intrahepatic transport steps is a notable feature of dynamic liver PET.

Quantitative PET of liver functions

Science.gov (United States)

Keiding, Susanne; Sørensen, Michael; Frisch, Kim; Gormsen, Lars C; Munk, Ole Lajord

2018-01-01

Improved understanding of liver physiology and pathophysiology is urgently needed to assist the choice of new and upcoming therapeutic modalities for patients with liver diseases. In this review, we focus on functional PET of the liver: 1) Dynamic PET with 2-deoxy-2-[18F]fluoro-D-galactose (18F-FDGal) provides quantitative images of the hepatic metabolic clearance K met (mL blood/min/mL liver tissue) of regional and whole-liver hepatic metabolic function. Standard-uptake-value (SUV) from a static liver 18F-FDGal PET/CT scan can replace K met and is currently used clinically. 2) Dynamic liver PET/CT in humans with 11C-palmitate and with the conjugated bile acid tracer [N-methyl-11C]cholylsarcosine (11C-CSar) can distinguish between individual intrahepatic transport steps in hepatic lipid metabolism and in hepatic transport of bile acid from blood to bile, respectively, showing diagnostic potential for individual patients. 3) Standard compartment analysis of dynamic PET data can lead to physiological inconsistencies, such as a unidirectional hepatic clearance of tracer from blood (K 1; mL blood/min/mL liver tissue) greater than the hepatic blood perfusion. We developed a new microvascular compartment model with more physiology, by including tracer uptake into the hepatocytes from the blood flowing through the sinusoids, backflux from hepatocytes into the sinusoidal blood, and re-uptake along the sinusoidal path. Dynamic PET data include information on liver physiology which cannot be extracted using a standard compartment model. In conclusion, SUV of non-invasive static PET with 18F-FDGal provides a clinically useful measurement of regional and whole-liver hepatic metabolic function. Secondly, assessment of individual intrahepatic transport steps is a notable feature of dynamic liver PET. PMID:29755841

Rigid-body motion correction of the liver in image reconstruction for golden-angle stack-of-stars DCE MRI.

Science.gov (United States)

Johansson, Adam; Balter, James; Cao, Yue

2018-03-01

Respiratory motion can affect pharmacokinetic perfusion parameters quantified from liver dynamic contrast-enhanced MRI. Image registration can be used to align dynamic images after reconstruction. However, intra-image motion blur remains after alignment and can alter the shape of contrast-agent uptake curves. We introduce a method to correct for inter- and intra-image motion during image reconstruction. Sixteen liver dynamic contrast-enhanced MRI examinations of nine subjects were performed using a golden-angle stack-of-stars sequence. For each examination, an image time series with high temporal resolution but severe streak artifacts was reconstructed. Images were aligned using region-limited rigid image registration within a region of interest covering the liver. The transformations resulting from alignment were used to correct raw data for motion by modulating and rotating acquired lines in k-space. The corrected data were then reconstructed using view sharing. Portal-venous input functions extracted from motion-corrected images had significantly greater peak signal enhancements (mean increase: 16%, t-test, P <  0.001) than those from images aligned using image registration after reconstruction. In addition, portal-venous perfusion maps estimated from motion-corrected images showed fewer artifacts close to the edge of the liver. Motion-corrected image reconstruction restores uptake curves distorted by motion. Motion correction also reduces motion artifacts in estimated perfusion parameter maps. Magn Reson Med 79:1345-1353, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Measurement of ventilation- and perfusion-mediated cooling during laser ablation in ex vivo human lung tumors

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Vietze, Andrea, E-mail: anvie@gmx.de [Department of Diagnostic Radiology and Neuroradiology, Ernst-Moritz-Arndt-Universitaet Greifswald, Sauerbruchstrasse, 17487 Greifswald (Germany); Koch, Franziska, E-mail: franzi_koch@hotmail.com [Department of Diagnostic Radiology and Neuroradiology, Ernst-Moritz-Arndt-Universitaet Greifswald, Sauerbruchstrasse, 17487 Greifswald (Germany); Laskowski, Ulrich, E-mail: ulrich.laskowski@klinikum-luedenscheid.de [Department of Vascular and Thoracic Surgery, Klinikum Luedenscheid, Paulmannshoeher Strasse 14, 58515 Luedenscheid (Germany); Linder, Albert, E-mail: albert.linder@klinikum-bremen-ost.de [Department of Thoracic Surgery, Klinikum Bremen-Ost, Zuericher Strasse 40, 28325 Bremen (Germany); Hosten, Norbert, E-mail: hosten@uni-greifswald.de [Department of Diagnostic Radiology and Neuroradiology, Ernst-Moritz-Arndt-Universitaet Greifswald, Sauerbruchstrasse, 17487 Greifswald (Germany)

2011-11-15

Purpose: Perfusion-mediated tissue cooling has often been described in the literature for thermal ablation therapies of liver tumors. The objective of this study was to investigate the cooling effects of both perfusion and ventilation during laser ablation of lung malignancies. Materials and methods: An ex vivo lung model was used to maintain near physiological conditions for the specimens. Fourteen human lung lobes containing only primary lung tumors (non-small cell lung cancer) were used. Laser ablation was carried out using a Nd:YAG laser with a wavelength of 1064 nm and laser fibers with 30 mm diffusing tips. Continuous invasive temperature measurement in 10 mm distance from the laser fiber was performed. Laser power was increased at 2 W increments starting at 10 W up to a maximum power of 12-20 W until a temperature plateau around 60 deg. C was reached at one sensor. Ventilation and perfusion were discontinued for 6 min each to assess their effects on temperature development. Results: The experiments lead to 25 usable temperature profiles. A significant temperature increase was observed for both discontinued ventilation and perfusion. In 6 min without perfusion, the temperature rose about 5.5 deg. C (mean value, P < 0.05); without ventilation it increased about 7.0 deg. C (mean value, P < 0.05). Conclusion: Ventilation- and perfusion-mediated tissue cooling are significant influencing factors on temperature development during thermal ablation. They should be taken into account during the planning and preparation of minimally invasive lung tumor treatment in order to achieve complete ablation.

Establishment of a hepatic cirrhosis and portal hypertension model by hepatic arterial perfusion with 80% alcohol.

Science.gov (United States)

Wang, Lei; He, Fu-Liang; Liu, Fu-Quan; Yue, Zhen-Dong; Zhao, Hong-Wei

2015-08-28

To determine the feasibility and safety of establishing a porcine hepatic cirrhosis and portal hypertension model by hepatic arterial perfusion with 80% alcohol. Twenty-one healthy Guizhou miniature pigs were randomly divided into three experimental groups and three control groups. The pigs in the three experimental groups were subjected to hepatic arterial perfusion with 7, 12 and 17 mL of 80% alcohol, respectively, while those in the three control groups underwent hepatic arterial perfusion with 7, 12 and 17 mL of saline, respectively. Hepatic arteriography and direct portal phlebography were performed on all animals before and after perfusion, and the portal venous pressure and diameter were measured before perfusion, immediately after perfusion, and at 2, 4 and 6 wk after perfusion. The following procedures were performed at different time points: routine blood sampling, blood biochemistry, blood coagulation and blood ammonia tests before surgery, and at 2, 4 and 6 wk after surgery; hepatic biopsy before surgery, within 6 h after surgery, and at 1, 2, 3, 4 and 5 wk after surgery; abdominal enhanced computed tomography examination before surgery and at 6 wk after surgery; autopsy and multi-point sampling of various liver lobes for histological examination at 6 wk after surgery. In experimental group 1, different degrees of hepatic fibrosis were observed, and one pig developed hepatic cirrhosis. In experimental group 2, there were cases of hepatic cirrhosis, different degrees of increased portal venous pressure, and intrahepatic portal venous bypass, but neither extrahepatic portal-systemic bypass circulation nor death occurred. In experimental group 3, two animals died and three animals developed hepatic cirrhosis, and different degrees of increased portal venous pressure and intrahepatic portal venous bypass were also observed, but there was no extrahepatic portal-systemic bypass circulation. It is feasible to establish an animal model of hepatic cirrhosis and

Whole-organ tissue engineering: decellularization and recellularization of three-dimensional matrix liver scaffolds.

Science.gov (United States)

Sabetkish, Shabnam; Kajbafzadeh, Abdol-Mohammad; Sabetkish, Nastaran; Khorramirouz, Reza; Akbarzadeh, Aram; Seyedian, Sanam Ladi; Pasalar, Parvin; Orangian, Saghar; Beigi, Reza Seyyed Hossein; Aryan, Zahra; Akbari, Hesam; Tavangar, Seyyed Mohammad

2015-04-01

To report the results of whole liver decellularization by two different methods. To present the results of grafting rat and sheep decellularized liver matrix (DLM) into the normal rat liver and compare natural cell seeding process in homo/xenograft of DLM. To compare the results of in vitro whole liver recellularization with rats' neonatal green fluorescent protein (GFP)-positive hepatic cells with outcomes of in vivo recellularization process. Whole liver of 8 rats and 4 sheep were resected and cannulated via the hepatic vein and perfused with sodium dodecyl sulfate (SDS) or Triton + SDS. Several examinations were performed to compare the efficacy of these two decellularization procedures. In vivo recellularization of sheep and rat DLMs was performed following transplantation of multiple pieces of both scaffolds in the subhepatic area of four rats. To compare the efficacy of different scaffolds in autologous cell seeding, biopsies of homograft and xenograft were assessed 8 weeks postoperatively. Whole DLMs of 4 rats were also recellularized in vitro by perfusion of rat's fetal GFP-positive hepatic cells with pulsatile bioreactor. Histological evaluation and enzymatic assay were performed for both in vivo and in vitro recellularized samples. The results of this study demonstrated that the triton method was a promising decellularization approach for preserving the three-dimensional structure of liver. In vitro recellularized DLMs were more similar to natural ones compared with in vivo recellularized livers. However, homografts showed better characteristics with more organized structure compared with xenografts. In vitro recellularization of liver scaffolds with autologous cells represents an attractive prospective for regeneration of liver as one of the most compound organs. In vivo cell seeding on the scaffold of the same species may have more satisfactory outcomes when compared with the results of xenotransplantation. This study theoretically may pave the road for

Perfusion dyssynchrony analysis

NARCIS (Netherlands)

Chiribiri, A.; Villa, A.D.M.; Sammut, E.; Breeuwer, M.; Nagel, E.

2015-01-01

AIMS: We sought to describe perfusion dyssynchrony analysis specifically to exploit the high temporal resolution of stress perfusion CMR. This novel approach detects differences in the temporal distribution of the wash-in of contrast agent across the left ventricular wall. METHODS AND RESULTS:

Brain perfusion: computed tomography applications

International Nuclear Information System (INIS)

Miles, K.A.

2004-01-01

Within recent years, the broad introduction of fast multi-detector computed tomography (CT) systems and the availability of commercial software for perfusion analysis have made cerebral perfusion imaging with CT a practical technique for the clinical environment. The technique is widely available at low cost, accurate and easy to perform. Perfusion CT is particularly applicable to those clinical circumstances where patients already undergo CT for other reasons, including stroke, head injury, subarachnoid haemorrhage and radiotherapy planning. Future technical developments in multi-slice CT systems may diminish the current limitations of limited spatial coverage and radiation burden. CT perfusion imaging on combined PET-CT systems offers new opportunities to improve the evaluation of patients with cerebral ischaemia or tumours by demonstrating the relationship between cerebral blood flow and metabolism. Yet CT is often not perceived as a technique for imaging cerebral perfusion. This article reviews the use of CT for imaging cerebral perfusion, highlighting its advantages and disadvantages and draws comparisons between perfusion CT and magnetic resonance imaging. (orig.)

Vasoactive mediators and splanchnic perfusion.

Science.gov (United States)

Reilly, P M; Bulkley, G B

1993-02-01

To provide an overview of the splanchnic hemodynamic response to circulatory shock. Previous studies performed in our own laboratory, as well as a computer-assisted search of the English language literature (MEDLINE, 1966 to 1991), followed by a selective review of pertinent articles. Studies were selected that demonstrated relevance to the splanchnic hemodynamic response to circulatory shock, either by investigating the pathophysiology or documenting the sequelae. Article selection included clinical studies as well as studies in appropriate animal models. Pertinent data were abstracted from the cited articles. The splanchnic hemodynamic response to circulatory shock is characterized by a selective vasoconstriction of the mesenteric vasculature mediated largely by the renin-angiotensin axis. This vasospasm, while providing a natural selective advantage to the organism in mild-to-moderate shock (preserving relative perfusion of the heart, kidneys, and brain), may, in more severe shock, cause consequent loss of the gut epithelial barrier, or even hemorrhagic gastritis, ischemic colitis, or ischemic hepatitis. From a physiologic standpoint, nonpulsatile cardiopulmonary bypass, a controlled form of circulatory shock, has been found experimentally to significantly increase circulating levels of angiotensin II, the hormone responsible for this selective splanchnic vasoconstriction. While angiotensin II has been viewed primarily as the mediator responsible for the increased total vascular resistance seen during (and after) cardiopulmonary bypass, it may also cause the disproportionate decrease in mesenteric perfusion, as measured in human subjects by intraluminal gastric tonometry and galactose clearance by the liver, as well as the consequent development of the multiple organ failure syndrome seen in 1% to 5% of patients after cardiac surgery.

Ordered synthesis and mobilization of glycogen in the perfused heart

International Nuclear Information System (INIS)

Brainard, J.R.; Hutson, J.Y.; Hoekenga, D.E.; Lenhoff, R.

1989-01-01

The molecular order of synthesis and mobilization of glycogen in the perfused heart was studied by 13 C NMR. By varying the glucose isotopomer ([1- 13 C]glucose or [2- 13 C]glucose) supplied to the heart, glycogen synthesized at different times during the perfusion was labeled at different carbon sites. Subsequently, the in situ mobilization of glycogen during ischemia was observed by detection of labeled lactate derived from glycolysis of the glucosyl monomers. When [1- 13 C]glucose was given initially in the perfusion and [2- 13 C]glucose was given second, [2- 13 C]lactate was detected first during ischemia and [3- 13 C]lactate second. This result, and the equivalent result when the glucose labels were given in the reverse order, demonstrates that glycogen synthesis and mobilization are ordered in the heart, where glycogen is found morphologically only as β particles. Previous studies of glycogen synthesis and mobilization in liver and adipocytes have suggested that the organization of β particles into α particles was partially responsible for ordered synthesis and mobilization. The observations reported here for cardiac glycogen suggest that another mechanism is responsible. In addition to examine the ordered synthesis and mobilization of cardiac glycogen, the authors have selectively monitored the NMR properties of 13 C-labeled glycogen synthesized early in the perfusion during further glycogen synthesis from a second, differently labeled substrate. During synthesis from the second labeled glucose monomer, the glycogen resonance from the first label decreased in integrated intensity and increased in line width. These results suggest either that there is significant isotopic exchange of glucosyl monomers in glycogen during net synthesis or that glucosyl residues incorporated into glycogen undergo motional restrictions as further glycogen synthesis occurs

A capillary-based perfusion phantom for simulation of brain perfusion for MRI

International Nuclear Information System (INIS)

Maciak, A.; Kronfeld, A.; Mueller-Forell, W.; Wille, C.; Kempski, O.; Stoeter, P.

2010-01-01

Purpose: The measurement of the CBF is a non-standardized procedure and there are no reliable gold standards. This abstract shows a capillary-based perfusion-phantom for CE-DSC-MRI. It has equivalent flow properties to those within the tissue capillary system of the human brain and allows the validation of the Siemens Perfusion (MR) software. Materials and Methods: The perfusion phantom consists of a dialyzer for the simulation of the capillary system, a feeding tube for simulation of the AIF and a pulsatile pump for simulation of the heart. Using this perfusion phantom, the exact determination of the gold standard CBF due to the well-known geometry of the phantom is easy. It was validated based on different perfusion measurements. These measurements were investigated with standard software (Siemens Perfusion MR). The software determined the CBF within the capillary system. Based on this CBF, a comparison to the gold standard was made with several different flow speeds. After AIF selection, a total of 726 CBF data points were automatically extracted by the software. Results: This results in a comparison of the gold standard CBF to these 726 CBF values. Therefore, a reproducible and reliable deviation estimation between gold standard CBF and measured CBF using the software was computed. It can be shown that the deviation between gold standard and software-based evaluation ranges between 1 and 31 %. Conclusion: There is no significance for any correlation between flow speed and amount of deviation. The mean measured CBF is 11.4 % higher than the gold standard CBF (p-value < 0.001). Using this kind of perfusion-phantom, the validation of different software systems allows reliable conclusions about their quality. (orig.)

Perfusion CT in acute stroke

International Nuclear Information System (INIS)

Eckert, Bernd; Roether, Joachim; Fiehler, Jens; Thomalla, Goetz

2015-01-01

Modern multislice CT scanners enable multimodal protocols including non-enhanced CT, CT angiography, and CT perfusion. A 64-slice CT scanner provides 4-cm coverage. To cover the whole brain, a 128 - 256-slice scanner is needed. The use of perfusion CT requires an optimized scan protocol in order to reduce exposure to radiation. As compared to non-enhanced CT and CT angiography, the use of CT perfusion increases detection rates of cerebral ischemia, especially small cortical ischemic lesions, while the detection of lacunar and infratentorial stroke lesions remains limited. Perfusion CT enables estimation of collateral flow in acute occlusion of large intra- or extracranial arteries. Currently, no established reliable thresholds are available for determining infarct core and penumbral tissue by CT perfusion. Moreover, perfusion parameters depend on the processing algorithms and the software used for calculation. However, a number of studies point towards a reduction of cerebral blood volume (CBV) below 2 ml/100 g as a critical threshold that identifies infarct core. Large CBV lesions are associated with poor outcome even in the context of recanalization. The extent of early ischemic signs on non-enhanced CT remains the main parameter from CT imaging to guide acute reperfusion treatment. Nevertheless, perfusion CT increases diagnostic and therapeutic certainty in the acute setting. Similar to stroke MRI, perfusion CT enables the identification of tissue at risk of infarction by the mismatch between infarct core and the larger area of critical hypoperfusion. Further insights into the validity of perfusion parameters are expected from ongoing trials of mechanical thrombectomy in stroke.

Dietary red palm oil supplementation reduces myocardial infarct size in an isolated perfused rat heart model

Directory of Open Access Journals (Sweden)

Esterhuyse Adriaan J

2010-06-01

Full Text Available Abstract Background and Aims Recent studies have shown that dietary red palm oil (RPO supplementation improves functional recovery following ischaemia/reperfusion in isolated hearts. The main aim of this study was to investigate the effects of dietary RPO supplementation on myocardial infarct size after ischaemia/reperfusion injury. The effects of dietary RPO supplementation on matrix metalloproteinase-2 (MMP2 activation and PKB/Akt phosphorylation were also investigated. Materials and methods Male Wistar rats were divided into three groups and fed a standard rat chow diet (SRC, a SRC supplemented with RPO, or a SRC supplemented with sunflower oil (SFO, for a five week period, respectively. After the feeding period, hearts were excised and perfused on a Langendorff perfusion apparatus. Hearts were subjected to thirty minutes of normothermic global ischaemia and two hours of reperfusion. Infarct size was determined by triphenyltetrazolium chloride staining. Coronary effluent was collected for the first ten minutes of reperfusion in order to measure MMP2 activity by gelatin zymography. Results Dietary RPO-supplementation decreased myocardial infarct size significantly when compared to the SRC-group and the SFO-supplemented group (9.1 ± 1.0% versus 30.2 ± 3.9% and 27.1 ± 2.4% respectively. Both dietary RPO- and SFO-supplementation were able to decrease MMP2 activity when compared to the SRC fed group. PKB/Akt phosphorylation (Thr 308 was found to be significantly higher in the dietary RPO supplemented group when compared to the SFO supplemented group at 10 minutes into reperfusion. There was, however, no significant changes observed in ERK phosphorylation. Conclusions Dietary RPO-supplementation was found to be more effective than SFO-supplementation in reducing myocardial infarct size after ischaemia/reperfusion injury. Both dietary RPO and SFO were able to reduce MMP2 activity, which suggests that MMP2 activity does not play a major role in

Volume perfusion CT imaging of cerebral vasospasm: diagnostic performance of different perfusion maps

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Othman, Ahmed E. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Radiology, Tuebingen (Germany); Afat, Saif; Nikoubashman, Omid; Mueller, Marguerite; Wiesmann, Martin; Brockmann, Carolin [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Schubert, Gerrit Alexander [RWTH Aachen University, Department of Neurosurgery, Aachen (Germany); Bier, Georg [Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Neuroradiology, Tuebingen (Germany); Brockmann, Marc A. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); University Hospital Mainz, Department of Neuroradiology, Mainz (Germany)

2016-08-15

In this study, we aimed to evaluate the diagnostic performance of different volume perfusion CT (VPCT) maps regarding the detection of cerebral vasospasm compared to angiographic findings. Forty-one datasets of 26 patients (57.5 ± 10.8 years, 18 F) with subarachnoid hemorrhage and suspected cerebral vasospasm, who underwent VPCT and angiography within 6 h, were included. Two neuroradiologists independently evaluated the presence and severity of vasospasm on perfusion maps on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting <50 %, 2 - vasospasm affecting >50 % of vascular territory). A third neuroradiologist independently assessed angiography for the presence and severity of vasospasm on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting < 50 %, 2 - vasospasm affecting > 50 % of vessel diameter). Perfusion maps of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time to drain (TTD) were evaluated regarding diagnostic accuracy for cerebral vasospasm with angiography as reference standard. Correlation analysis of vasospasm severity on perfusion maps and angiographic images was performed. Furthermore, inter-reader agreement was assessed regarding findings on perfusion maps. Diagnostic accuracy for TTD and MTT was significantly higher than for all other perfusion maps (TTD, AUC = 0.832; MTT, AUC = 0.791; p < 0.001). TTD revealed higher sensitivity than MTT (p = 0.007). The severity of vasospasm on TTD maps showed significantly higher correlation levels with angiography than all other perfusion maps (p ≤ 0.048). Inter-reader agreement was (almost) perfect for all perfusion maps (kappa ≥ 0.927). The results of this study indicate that TTD maps have the highest sensitivity for the detection of cerebral vasospasm and highest correlation with angiography regarding the severity of vasospasm. (orig.)

Relations between CT perfusion parameters and degree of hepatic ischemia reperfusion injury in a rabbit model

International Nuclear Information System (INIS)

Guo Chengwei; Shen Sandi; Yi Xianlin; Zhang Zhonglin; Liu Zaiyi; Liang Changhong

2011-01-01

Objective: To observe the changes of hepatic CT perfusion parameters and their correlation with serum aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP) in a rabbit hepatic ischemia reperfusion injury (IRI) model. Methods: Hepatic IRI was produced in rabbits by inducing left liver lobe ischemia (60 min) followed by 6 h, 12 h and 24 h reperfusion (6 rabbits were used for each reperfusion interval). Additional 6 rabbits were served as sham-operated controls. All the rabbits were scanned with a dynamic iCT protocol. Blood samples were taken from the superior mesenteric vein to measure the levels of serum amylase (ALT, AST, and ALP) in various groups, and liver samples were taken for histological examinations after scanning. One-way analysis of variance (ANOVA) was used to determine differences between groups. The correlations of CT perfusion parameters with serum levels were analyzed using Pearson correlation coefficient. Results: Heterogeneity of CT perfusion patterns appeared in the 6 h groups, which presented as low enhanced area [(25.1±9.3) ml · min -1 · 100 mg -1 ]. In reduced perfusion regions of IRI group, HAP of 12 h IRI group [(19.5± 13.6) ml · min -1 · 100 mg -1 ], 24 h IRI group (8.0±2.7) ml · min -1 · 100 mg -1 ], HPP of 6 h IRI group [(10.8±5.5) ml · min -1 · 100 mg -1 ], 12 h IRI group [(14.4±5.2) ml · min -1 · 100 mg -1 ] , 24 h IRI group [(7.8±3.3) ml · min -1 · 100 mg -1 ] and TLP of 6 h IRI group [(35.9±14.0) ml · min -1 · 100 mg -1 ], 12 h IRI group [(33.9±16.1) ml · min -1 · 100 mg -1 ], 24 h IRI group [(16.0± 5.5) ml · min -1 · 100 mg -1 ] were lower than those of sham group [HAP (21.2±10.5) ml · min -1 · 100 mg -1 , HPP (63.5±24.0) ml · min -1 · 100 mg -1 , TLP (81.4±24.8) ml · min -1 · 100 mg -1 ] (F=8.376, 25.950, 16.925, P<0.01). However, HPI of 6 h IRI group [(65.9±3.9)%], 12 h IRI group [(54.2±16.7)%], and 24 h IRI group [(48.9±10.0)%] were higher compared to sham

Preoperative computed tomography volumetry and graft weight estimation in adult living donor liver transplantation

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Pinheiro, Rafael S.; Cruz Junior, Ruy J.; Andraus, Wellington; Ducatti, Liliana; Martino, Rodrigo B.; Nacif, Lucas S.; Rocha-Santos, Vinicius; Arantes, Rubens M.; D' Albuquerque, Luiz A.C., E-mail: rsnpinheiro@gmail.com [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Gastroenterologia. Div. de Transplante de Orgaos do Aparelho Digestivo; Lai, Quirino [Universidade de L' Aquila, San Salvatore Hospital (Italy); Ibuki, Felicia S.; Rocha, Manoel S. [Universidade de Sao Paulo (USP), SP (Brazil). Departamento de Radiologia

2017-09-01

Background: Computed tomography volumetry (CTV) is a useful tool for predicting graft weights (GW) for living donor liver transplantation (LDLT). Few studies have examined the correlation between CTV and GW in normal liver parenchyma. Aim: To analyze the correlation between CTV and GW in an adult LDLT population and provide a systematic review of the existing mathematical models to calculate partial liver graft weight. Methods: Between January 2009 and January 2013, 28 consecutive donors undergoing right hepatectomy for LDLT were retrospectively reviewed. All grafts were perfused with HTK solution. Estimated graft volume was estimated by CTV and these values were compared to the actual graft weight, which was measured after liver harvesting and perfusion. Results: Median actual GW was 782.5 g, averaged 791.43±136 g and ranged from 520-1185 g. Median estimated graft volume was 927.5 ml, averaged 944.86±200.74 ml and ranged from 600-1477 ml. Linear regression of estimated graft volume and actual GW was significantly linear (GW=0.82 estimated graft volume, r{sup 2} =0.98, slope=0.47, standard deviation of 0.024 and p<0.0001). Spearman Linear correlation was 0.65 with 95% CI of 0.45 – 0.99 (p<0.0001). Conclusion: The one-to-one rule did not applied in patients with normal liver parenchyma. A better estimation of graft weight could be reached by multiplying estimated graft volume by 0.82. (author)

Preoperative computed tomography volumetry and graft weight estimation in adult living donor liver transplantation

International Nuclear Information System (INIS)

Pinheiro, Rafael S.; Cruz Junior, Ruy J.; Andraus, Wellington; Ducatti, Liliana; Martino, Rodrigo B.; Nacif, Lucas S.; Rocha-Santos, Vinicius; Arantes, Rubens M.; D'Albuquerque, Luiz A.C.; Ibuki, Felicia S.; Rocha, Manoel S.

2017-01-01

Background: Computed tomography volumetry (CTV) is a useful tool for predicting graft weights (GW) for living donor liver transplantation (LDLT). Few studies have examined the correlation between CTV and GW in normal liver parenchyma. Aim: To analyze the correlation between CTV and GW in an adult LDLT population and provide a systematic review of the existing mathematical models to calculate partial liver graft weight. Methods: Between January 2009 and January 2013, 28 consecutive donors undergoing right hepatectomy for LDLT were retrospectively reviewed. All grafts were perfused with HTK solution. Estimated graft volume was estimated by CTV and these values were compared to the actual graft weight, which was measured after liver harvesting and perfusion. Results: Median actual GW was 782.5 g, averaged 791.43±136 g and ranged from 520-1185 g. Median estimated graft volume was 927.5 ml, averaged 944.86±200.74 ml and ranged from 600-1477 ml. Linear regression of estimated graft volume and actual GW was significantly linear (GW=0.82 estimated graft volume, r"2 =0.98, slope=0.47, standard deviation of 0.024 and p<0.0001). Spearman Linear correlation was 0.65 with 95% CI of 0.45 – 0.99 (p<0.0001). Conclusion: The one-to-one rule did not applied in patients with normal liver parenchyma. A better estimation of graft weight could be reached by multiplying estimated graft volume by 0.82. (author)

PREOPERATIVE COMPUTED TOMOGRAPHY VOLUMETRY AND GRAFT WEIGHT ESTIMATION IN ADULT LIVING DONOR LIVER TRANSPLANTATION

Science.gov (United States)

PINHEIRO, Rafael S.; CRUZ-JR, Ruy J.; ANDRAUS, Wellington; DUCATTI, Liliana; MARTINO, Rodrigo B.; NACIF, Lucas S.; ROCHA-SANTOS, Vinicius; ARANTES, Rubens M; LAI, Quirino; IBUKI, Felicia S.; ROCHA, Manoel S.; D´ALBUQUERQUE, Luiz A. C.

2017-01-01

ABSTRACT Background: Computed tomography volumetry (CTV) is a useful tool for predicting graft weights (GW) for living donor liver transplantation (LDLT). Few studies have examined the correlation between CTV and GW in normal liver parenchyma. Aim: To analyze the correlation between CTV and GW in an adult LDLT population and provide a systematic review of the existing mathematical models to calculate partial liver graft weight. Methods: Between January 2009 and January 2013, 28 consecutive donors undergoing right hepatectomy for LDLT were retrospectively reviewed. All grafts were perfused with HTK solution. Estimated graft volume was estimated by CTV and these values were compared to the actual graft weight, which was measured after liver harvesting and perfusion. Results: Median actual GW was 782.5 g, averaged 791.43±136 g and ranged from 520-1185 g. Median estimated graft volume was 927.5 ml, averaged 944.86±200.74 ml and ranged from 600-1477 ml. Linear regression of estimated graft volume and actual GW was significantly linear (GW=0.82 estimated graft volume, r2=0.98, slope=0.47, standard deviation of 0.024 and p<0.0001). Spearman Linear correlation was 0.65 with 95% CI of 0.45 - 0.99 (p<0.0001). Conclusion: The one-to-one rule did not applied in patients with normal liver parenchyma. A better estimation of graft weight could be reached by multiplying estimated graft volume by 0.82. PMID:28489167

Standardized perfusion value of the esophageal carcinoma and its correlation with quantitative CT perfusion parameter values

Energy Technology Data Exchange (ETDEWEB)

Djuric-Stefanovic, A., E-mail: avstefan@eunet.rs [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Saranovic, Dj., E-mail: crvzve4@gmail.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Sobic-Saranovic, D., E-mail: dsobic2@gmail.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Center of Nuclear Medicine, Clinical Center of Serbia, Belgrade (Serbia); Masulovic, D., E-mail: draganmasulovic@yahoo.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Artiko, V., E-mail: veraart@beotel.rs [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Center of Nuclear Medicine, Clinical Center of Serbia, Belgrade (Serbia)

2015-03-15

Purpose: Standardized perfusion value (SPV) is a universal indicator of tissue perfusion, normalized to the whole-body perfusion, which was proposed to simplify, unify and allow the interchangeability among the perfusion measurements and comparison between the tumor perfusion and metabolism. The aims of our study were to assess the standardized perfusion value (SPV) of the esophageal carcinoma, and its correlation with quantitative CT perfusion measurements: blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) of the same tumor volume samples, which were obtained by deconvolution-based CT perfusion analysis. Methods: Forty CT perfusion studies of the esophageal cancer were analyzed, using the commercial deconvolution-based CT perfusion software (Perfusion 3.0, GE Healthcare). The SPV of the esophageal tumor and neighboring skeletal muscle were correlated with the corresponding mean tumor and muscle quantitative CT perfusion parameter values, using Spearman's rank correlation coefficient (r{sub S}). Results: Median SPV of the esophageal carcinoma (7.1; range: 2.8–13.4) significantly differed from the SPV of the skeletal muscle (median: 1.0; range: 0.4–2.4), (Z = −5.511, p < 0.001). The cut-off value of the SPV of 2.5 enabled discrimination of esophageal cancer from the skeletal muscle with sensitivity and specificity of 100%. SPV of the esophageal carcinoma significantly correlated with corresponding tumor BF (r{sub S} = 0.484, p = 0.002), BV (r{sub S} = 0.637, p < 0.001) and PS (r{sub S} = 0.432, p = 0.005), and SPV of the skeletal muscle significantly correlated with corresponding muscle BF (r{sub S} = 0.573, p < 0.001), BV (r{sub S} = 0.849, p < 0.001) and PS (r{sub S} = 0.761, p < 0.001). Conclusions: We presented a database of the SPV for the esophageal cancer and proved that SPV of the esophageal neoplasm significantly differs from the SPV of the skeletal muscle, which represented a sample of healthy

Nuclear magnetic resonance of perfused tissue

International Nuclear Information System (INIS)

Harpen, M.D.; Allison, R.C.

1986-01-01

The effect of perfusion on the NMR signal observed in NMR imaging is studied in a phantom and in two isolated perfused canine lungs. It is observed that perfusion in tissue has little effect on longitudinal relaxation times. Transverse relaxation rates are observed to correlate linearly with rates of perfusion, in accordance with a model presented. (author)

Dynamic CT myocardial perfusion imaging identifies early perfusion abnormalities in diabetes and hypertension : Insights from a multicenter registry

NARCIS (Netherlands)

Vliegenthart, Rozemarijn; De Cecco, Carlo N.; Wichmann, Julian L.; Meinel, Felix G.; Pelgrim, Gert Jan; Tesche, Christian; Ebersberger, Ullrich; Pugliese, Francesca; Bamberg, Fabian; Choe, Yeon Hyeon; Wang, Yining; Schoepf, U. Joseph

2016-01-01

Background: To identify patients with early signs of myocardial perfusion reduction, a reference base for perfusion measures is needed. Objective: To analyze perfusion parameters derived from dynamic computed tomography perfusion imaging (CTPI) in patients with suspected coronary artery disease

Persufflation (or gaseous oxygen perfusion) as a method of organ preservation.

Science.gov (United States)

Suszynski, Thomas M; Rizzari, Michael D; Scott, William E; Tempelman, Linda A; Taylor, Michael J; Papas, Klearchos K

2012-06-01

Improved preservation techniques have the potential to improve transplant outcomes by better maintaining donor organ quality and by making more organs available for allotransplantation. Persufflation, (PSF, gaseous oxygen perfusion) is potentially one such technique that has been studied for over a century in a variety of tissues, but has yet to gain wide acceptance for a number of reasons. A principal barrier is the perception that ex vivo PSF will cause in vivo embolization post-transplant. This review summarizes the extensive published work on heart, liver, kidney, small intestine and pancreas PSF, discusses the differences between anterograde and retrograde PSF, and between PSF and other conventional methods of organ preservation (static cold storage, hypothermic machine perfusion). Prospective implications of PSF within the broader field of organ transplantation, and in the specific application with pancreatic islet isolation and transplant are also discussed. Finally, key issues that need to be addressed before PSF becomes a more widely utilized preservation strategy are summarized and discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

Methodology for ventilation/perfusion SPECT

DEFF Research Database (Denmark)

Bajc, Marika; Neilly, Brian; Miniati, Massimo

2010-01-01

radiolabeled liquid aerosols are not restricted to the presence of obstructive lung disease. Radiolabeled macroaggregated human albumin is the imaging agent of choice for perfusion scintigraphy. An optimal combination of nuclide activities and acquisition times for ventilation and perfusion, collimators......Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas over......, and imaging matrix yields an adequate V/Q SPECT study in approximately 20 minutes of imaging time. The recommended protocol based on the patient remaining in an unchanged position during the initial ventilation study and the perfusion study allows presentation of matching ventilation and perfusion slices...

Hydrostatic determinants of cerebral perfusion

International Nuclear Information System (INIS)

Wagner, E.M.; Traystman, R.J.

1986-01-01

We examined the cerebral blood flow response to alterations in perfusion pressure mediated through decreases in mean arterial pressure, increases in cerebrospinal fluid (CSF) pressure, and increases in jugular venous (JV) pressure in 42 pentobarbital anesthetized dogs. Each of these three pressures was independently controlled. Cerebral perfusion pressure was defined as mean arterial pressure minus JV or CSF pressure, depending on which was greater. Mean hemispheric blood flow was measured with the radiolabeled microsphere technique. Despite 30-mm Hg reductions in mean arterial pressure or increases in CSF or JV pressure, CBF did not change as long as the perfusion pressure remained greater than approximately 60 mm Hg. However, whenever perfusion pressure was reduced to an average of 48 mm Hg, cerebral blood flow decreased 27% to 33%. These results demonstrate the capacity of the cerebral vascular bed to respond similarly to changes in the perfusion pressure gradient obtained by decreasing mean arterial pressure, increasing JV pressure or increasing CSF pressure, and thereby support the above definition of cerebral perfusion pressure

"Artificial micro organs"--a microfluidic device for dielectrophoretic assembly of liver sinusoids.

Science.gov (United States)

Schütte, Julia; Hagmeyer, Britta; Holzner, Felix; Kubon, Massimo; Werner, Simon; Freudigmann, Christian; Benz, Karin; Böttger, Jan; Gebhardt, Rolf; Becker, Holger; Stelzle, Martin

2011-06-01

In order to study possible toxic side effects of potential drug compounds in vitro a reliable test system is needed. Predicting liver toxicity presents a major challenge of particular importance as liver cells grown in a cell culture suffer from a rapid loss of their liver specific functions. Therefore we are developing a new microfluidic test system for liver toxicity. This test system is based on an organ-like liver 3D co-culture of hepatocytes and endothelial cells. We devised a microfluidic chip featuring cell culture chambers with integrated electrodes for the assembly of liver sinusoids by dielectrophoresis. Fluid channels enable an organ-like perfusion with culture media and test compounds. Different chamber designs were studied and optimized with regard to dielectrophoretic force distribution, hydrodynamic flow profile, and cell trapping rate using numeric simulations. Based on simulation results a microchip was injection-moulded from COP. This chip allowed the assembly of viable hepatocytes and endothelial cells in a sinusoid-like fashion.

Non-viral ex vivo hepatic gene transfer by in situ lipofection of liver and intraperitoneal transplantation of hepatocytes.

Science.gov (United States)

Rangarajan, P N; Vatsala, P G; Ashok, M S; Srinivas, V K; Habibullah, C M; Padmanaban, G

1997-04-29

Perfusion of liver with plasmid DNA-lipofectin complexes via the portal vein results in efficient accumulation of the vector in hepatocytes. Such hepatocytes, when administered intraperitoneally into a hepatectomized rat, repopulate the liver and express the transgene efficiently. This procedure obviates the need for large-scale hepatocyte culture for ex vivo gene transfer. Further, intraperitoneal transplantation is a simple and cost-effective strategy of introducing genetically modified hepatocytes into liver. Thus, in situ lipofection of liver and intraperitoneal transfer of hepatocytes can be developed into a novel method of non-viral ex vivo gene transfer technique that has applications in the treatment of metabolic disorders of liver and hepatic gene therapy.

Recellularization via the bile duct supports functional allogenic and xenogenic cell growth on a decellularized rat liver scaffold.

Science.gov (United States)

Hassanein, Wessam; Uluer, Mehmet C; Langford, John; Woodall, Jhade D; Cimeno, Arielle; Dhru, Urmil; Werdesheim, Avraham; Harrison, Joshua; Rivera-Pratt, Carlos; Klepfer, Stephen; Khalifeh, Ali; Buckingham, Bryan; Brazio, Philip S; Parsell, Dawn; Klassen, Charlie; Drachenberg, Cinthia; Barth, Rolf N; LaMattina, John C

2017-01-02

Recent years have seen a proliferation of methods leading to successful organ decellularization. In this experiment we examine the feasibility of a decellularized liver construct to support growth of functional multilineage cells. Bio-chamber systems were used to perfuse adult rat livers with 0.1% SDS for 24 hours yielding decellularized liver scaffolds. Initially, we recellularized liver scaffolds using a human tumor cell line (HepG2, introduced via the bile duct). Subsequent studies were performed using either human tumor cells co-cultured with human umbilical vein endothelial cells (HUVECs, introduced via the portal vein) or rat neonatal cell slurry (introduced via the bile duct). Bio-chambers were used to circulate oxygenated growth medium via the portal vein at 37C for 5-7 days. Human HepG2 cells grew readily on the scaffold (n = 20). HepG2 cells co-cultured with HUVECs demonstrated viable human endothelial lining with concurrent hepatocyte growth (n = 10). In the series of neonatal cell slurry infusion (n = 10), distinct foci of neonatal hepatocytes were observed to repopulate the parenchyma of the scaffold. The presence of cholangiocytes was verified by CK-7 positivity. Quantitative albumin measurement from the grafts showed increasing albumin levels after seven days of perfusion. Graft albumin production was higher than that observed in traditional cell culture. This data shows that rat liver scaffolds support human cell ingrowth. The scaffold likewise supported the engraftment and survival of neonatal rat liver cell slurry. Recellularization of liver scaffolds thus presents a promising model for functional liver engineering.

Subcellular distribution of styrene oxide in rat liver

International Nuclear Information System (INIS)

Pacifici, G.M.; Cuoci, L.; Rane, A.

1984-01-01

The subcellular distribution of ( 3 H)-styrene-7,8-oxide was studied in the rat liver. The compound was added to liver homogenate to give a final concentration of 2 X 10(-5); 2 X 10(-4) and 2 X 10(-3) M. Subcellular fractions were obtained by differential centrifugation. Most of styrene oxide (59-88%) was associated with the cytosolic fraction. Less than 15 percent of the compound was retrieved in each of the nuclear, mitochondrial and microsomal fractions. A considerable percentage of radioactivity was found unextractable with the organic solvents, suggesting that styrene oxide reacted with the endogenous compounds. The intracellular distribution of this epoxide was also studied in the perfused rat liver. Comparable results with those previously described were obtained. The binding of styrene oxide to the cytosolic protein was investigated by equilibrium dialysis and ultrafiltration. Only a small percentage of the compound was bound to protein

Intra-Arterial MR Perfusion Imaging of Meningiomas: Comparison to Digital Subtraction Angiography and Intravenous MR Perfusion Imaging.

Directory of Open Access Journals (Sweden)

Mark A Lum

Full Text Available To evaluate the ability of IA MR perfusion to characterize meningioma blood supply.Studies were performed in a suite comprised of an x-ray angiography unit and 1.5T MR scanner that permitted intraprocedural patient movement between the imaging modalities. Patients underwent intra-arterial (IA and intravenous (IV T2* dynamic susceptibility MR perfusion immediately prior to meningioma embolization. Regional tumor arterial supply was characterized by digital subtraction angiography and classified as external carotid artery (ECA dural, internal carotid artery (ICA dural, or pial. MR perfusion data regions of interest (ROIs were analyzed in regions with different vascular supply to extract peak height, full-width at half-maximum (FWHM, relative cerebral blood flow (rCBF, relative cerebral blood volume (rCBV, and mean transit time (MTT. Linear mixed modeling was used to identify perfusion curve parameter differences for each ROI for IA and IV MR imaging techniques. IA vs. IV perfusion parameters were also directly compared for each ROI using linear mixed modeling.18 ROIs were analyzed in 12 patients. Arterial supply was identified as ECA dural (n = 11, ICA dural (n = 4, or pial (n = 3. FWHM, rCBV, and rCBF showed statistically significant differences between ROIs for IA MR perfusion. Peak Height and FWHM showed statistically significant differences between ROIs for IV MR perfusion. RCBV and MTT were significantly lower for IA perfusion in the Dural ECA compared to IV perfusion. Relative CBF in IA MR was found to be significantly higher in the Dural ICA region and MTT significantly lower compared to IV perfusion.

Pulmonary perfusion ''without ventilation''

International Nuclear Information System (INIS)

Chapman, C.N.; Sziklas, J.J.; Spencer, R.P.; Rosenberg, R.J.

1983-01-01

An 88-yr-old man, with prior left upper lobectomy and phrenic nerve injury, had a ventilation/perfusion lung image. Both wash-in and equilibrium ventilation images showed no radioactive gas in the left lung. Nevertheless, the left lung was perfused. A similar result was obtained on a repeat study 8 days later. Delayed images, during washout, showed some radioactive gas in the left lung. Nearly absent ventilation (but continued perfusion) of that lung might have been related to altered gas dynamics brought about by the prior lobectomy, a submucosal bronchial lesion, phrenic nerve damage, and limited motion of the left part of the diaphragm. This case raises the issue of the degree of ventilation (and the phase relationship between the lungs) required for the entry of radioactive gas into a diseased lung, and the production of a ''reversed ventilation/perfusion mismatch.''

Contrast-enhanced ultrasound evaluation of hepatic microvascular changes in liver diseases.

Science.gov (United States)

Ridolfi, Francesco; Abbattista, Teresa; Busilacchi, Paolo; Brunelli, Eugenio

2012-10-07

To assess if software assisted-contrast-enhanced ultrasonography (CEUS) provides reproducible perfusion parameters of hepatic parenchyma in patients affected by chronic liver disease. Forty patients with chronic viral liver disease, with (n = 20) or without (n = 20) cirrhosis, and 10 healthy subjects underwent CEUS and video recordings of each examination were then analysed with Esaote's Qontrast software. CEUS dedicated software Qontrast was used to determine peak (the maximum signal intensity), time to peak (TTP), region of blood value (RBV) proportional to the area under the time-intensity curve, mean transit time (MTT) measured in seconds and region of blood flow (RBF). Qontrast-assisted CEUS parameters displayed high inter-observer reproducibility (κ coefficients of 0.87 for MTT and 0.90 TTP). When the region of interest included a main hepatic vein, Qontrast-calculated TTP was significantly shorter in cirrhotic patients (vs non-cirrhotics and healthy subjects) (71.0 ± 11.3 s vs. 82.4 ± 15.6 s, 86.3 ± 20.3 s, P < 0.05). MTTs in the patients with liver cirrhosis were significantly shorter than those of controls (111.9 ± 22.0 s vs. 139.4 ± 39.8 s, P < 0.05), but there was no significant difference between the cirrhotic and non-cirrhotic groups (111.9 ± 22.0 s vs. 110.3 ± 14.6 s). Peak enhancement in the patients with liver cirrhosis was also higher than that observed in controls (23.9 ± 5.9 vs. 18.9 ± 7.1, P = 0.05). There were no significant intergroup differences in the RBVs and RBFs. Qontrast-assisted CEUS revealed reproducible differences in liver perfusion parameters during the development of hepatic fibrogenesis.

Contralateral thalamic hypoperfusion on brain perfusion SPECT

International Nuclear Information System (INIS)

Lee, Seok Mo; Bae, Sang Kyun; Yoo, Kyung Moo; Yum, Ha Yong

2000-01-01

Brain perfusion single photon emission computed tomography (SPECT) is useful for the localization of cerebrovascular lesion and sometimes reveals more definite lesion than radiologic imaging modality such as CT or MRI does. The purpose of this study was to evaluate the diagnostic usefulness of brain perfusion SPECT in patients with hemisensory impairment. Thirteen consecutive patients (M:F= 8:5, mean age = 48) who has hemisensory impairment were included. Brain perfusion SPECT was performed after intravenous injection of 1110 MBq of Tc-99m ECD. The images were obtained using a dual-head gamma camera with ultra-high resolution collimator. Semiquantitative analysis was performed after placing multiple ROIs on cerebral cortex, basal ganglia, thalamus and cerebellum. There were 10 patients with left hemisensory impairment and 3 patients with right-sided symptom. Only 2 patients revealed abnormal signal change in the thalamus on MRI. But brain perfusion SPECT showed decreased perfusion in the thalamus in 9 patients. Six patients among 10 patients with left hemisensory impairment revealed decreased perfusion in the contralateral thalamus on brain SPECT. The other 4 patients revealed no abnormality. Two patients among 3 patients with right hemisensory impairment also showed decreased perfusion in the contralateral thalamus on brain SPECT. One patients with right hemisensory impairment showed ipsilateral perfusion decrease. Two patients who had follow-up brain perfusion SEPCT after treatment revealed normalization of perfusion in the thalamus. Brain perfusion SPECT might be a useful tool in diagnosing patients with hemisensory impairment

Magnetic resonance perfusion imaging without contrast media

International Nuclear Information System (INIS)

Martirosian, Petros; Graf, Hansjoerg; Schick, Fritz; Boss, Andreas; Schraml, Christina; Schwenzer, Nina F.; Claussen, Claus D.

2010-01-01

Principles of magnetic resonance imaging techniques providing perfusion-related contrast weighting without administration of contrast media are reported and analysed systematically. Especially common approaches to arterial spin labelling (ASL) perfusion imaging allowing quantitative assessment of specific perfusion rates are described in detail. The potential of ASL for perfusion imaging was tested in several types of tissue. After a systematic comparison of technical aspects of continuous and pulsed ASL techniques the standard kinetic model and tissue properties of influence to quantitative measurements of perfusion are reported. For the applications demonstrated in this paper a flow-sensitive alternating inversion recovery (FAIR) ASL perfusion preparation approach followed by true fast imaging with steady precession (true FISP) data recording was developed and implemented on whole-body scanners operating at 0.2, 1.5 and 3 T for quantitative perfusion measurement in various types of tissue. ASL imaging provides a non-invasive tool for assessment of tissue perfusion rates in vivo. Images recorded from kidney, lung, brain, salivary gland and thyroid gland provide a spatial resolution of a few millimetres and sufficient signal to noise ratio in perfusion maps after 2-5 min of examination time. Newly developed ASL techniques provide especially high image quality and quantitative perfusion maps in tissues with relatively high perfusion rates (as also present in many tumours). Averaging of acquisitions and image subtraction procedures are mandatory, leading to the necessity of synchronization of data recording to breathing in abdominal and thoracic organs. (orig.)

Metabolism and Clearance of T-2 Mycotoxin in Perfused Rat Livers

Science.gov (United States)

1986-02-10

nucleottde system in rat liver. B5ochem. J. 117, 499-503. 4ALLACE, E. 4., PATHRE, S. V., MIROCHA, C. J., ROSISON, T. S., AND FENTON , S. W. (1977). Synthesis...lactating cow. Food Cosmet . Toxicol. 19, 31- 39. YOSHIZAWA, T., SAKAMOTO, T., AND KUWAMWA, K. (1985). Structures of Deepoxytrichothecene mecabolites

Hepatic arterial perfusion increases in the early stage of severe acute pancreatitis patients: Evaluation by perfusion computed tomography

International Nuclear Information System (INIS)

Koyasu, Sho; Isoda, Hiroyoshi; Tsuji, Yoshihisa; Yamamoto, Hiroshi; Matsueda, Kazuhiro; Watanabe, Yuji; Chiba, Tsutomu; Togashi, Kaori

2012-01-01

Purpose: Although hepatic perfusion abnormalities have been reported in patients with acute pancreatitis, hepatic perfusion with severe acute pancreatitis (SAP) has not been quantitatively evaluated in humans. Therefore, we investigated hepatic perfusion in patients with SAP using perfusion CT. Materials and methods: Hepatic perfusion CT was performed in 67 patients with SAP within 3 days after symptom onset. The patients were diagnosed as having SAP according to the Atlanta criteria. Fifteen cases were established as a control group. Perfusion CT was obtained for 54 s beginning with a bolus injection of 40 ml of contrast agent (600–630 mgI/kg) at a flow rate of 4 ml/s. Perfusion data were analyzed by the dual-input maximum slope method to obtain hepatic arterial perfusion (HAP) and hepatic portal perfusion (HPP). Finally, we compared HAP and HPP in SAP patients with those in the control group, respectively. Results: Average HAP was significantly higher in SAP patients than in the control group (75.1 ± 38.0 vs. 38.2 ± 9.0 ml/min/100 ml; p < 0.001). There was no significant difference in average HPP between SAP patients and the control group (206.7 ± 54.9 vs. 204.4 ± 38.5 ml/min/100 ml; p = 0.92). Conclusion: Using quantitative analysis on perfusion CT, we first demonstrated an increase of HAP in the right hepatic lobe in SAP patients.

Role of Tc-99m labeled RBC SPECT in haemangioma of the liver

International Nuclear Information System (INIS)

Saddadi, Fariba; Kamali, Hosein; Faghihi, Amir Hosein; Shokouhizadeh, Reza

2004-01-01

Full text: Haemangioma of the liver must be included in the differential diagnosis of all focal hepatic lesions. Nuclear medicine imaging techniques continue to play a unique role in the evaluation of hepatic masses. Role of planar scintigraphy in the diagnosis of hepatic haemangioma is already established although it has limitations, which can be significantly improved by means of SPECT studies. A prospective study was carried out to evaluate Tc-99m red blood cell SPECT imaging in liver haemangioma and compare it with CT findings. Radionuclide liver scan, both planar and SPECT was done in 10 patients who had 16 liver masses diagnosed as haemangiomas on their CT. The acquisition protocol was an immediate perfusion phase study in an anterior view followed by SPECT of the liver at 2 hours. A perfusion/blood-pool mismatch is the hallmark finding for hepatic haemangioma. The smallest haemangioma detected with isotope scan was of 1.55 cm size. Planar scintigraphy showed a sensitivity of 82% versus 94.2% for SPECT. It was mostly due to missing of lesions less than 2 cm in size on planar scans. For cavernous haemangioma (n=4) the specificity and positive predictive value was 100%. We believe that hepatic scintigraphy still continues to play an important role in the diagnosis of hepatic masses especially for liver haemangioma where Tc-99m labeled red blood cell scanning has considerably high specificity. However, planar imaging has poor sensitivity especially for the identification of smaller lesions. Hepatic scintigraphy is non-invasive, easy to perform and inexpensive. In our opinion, when a suspicion of hepatic haemangioma is raised on CT or other imaging modalities, it needs to be confirmed by radionuclide blood-pool study. (author)

A new veno-venous bypass type for ex-vivo liver resection in dogs.

Science.gov (United States)

Lei, Peng; Liu, Shi-Qi; Cui, Xiao-Hai; Lv, Yi; Zhao, Ge; Li, Jian-Hui

2013-08-01

Ex-vivo liver resection is a procedure in which the liver is completely removed, perfused and after bench surgery, the liver is autotransplanted to the original site. Ex-vivo liver resection is an important treatment for unresectable liver tumors. This surgical procedure requires long operation time, during which blood flow must be carefully maintained to avoid venous congestion. An effective veno-venous bypass (VVB) may meet this requirement. The present study was to test our new designed VVB device which comprised one heparinized polyvinylchloride tube and three magnetic rings. The efficacy of this device was tested in five dogs. A VVB was established in 6-10 minutes. There was no leakage during the procedure. Hemodynamics was stable at anhepatic phase, which indicated that the bypass was successful. This newly-developed VVB device maintained circulation stability during ex-vivo liver resection in our dog model and thus, this VVB device significantly shortened the operation time.

Improved visualization of delayed perfusion in lung MRI

International Nuclear Information System (INIS)

Risse, Frank; Eichinger, Monika; Kauczor, Hans-Ulrich; Semmler, Wolfhard; Puderbach, Michael

2011-01-01

Introduction: The investigation of pulmonary perfusion by three-dimensional (3D) dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was proposed recently. Subtraction images are generated for clinical evaluation, but temporal information is lost and perfusion defects might therefore be masked in this process. The aim of this study is to demonstrate a simple analysis strategy and classification for 3D-DCE-MRI perfusion datasets in the lung without omitting the temporal information. Materials and methods: Pulmonary perfusion measurements were performed in patients with different lung diseases using a 1.5 T MR-scanner with a time-resolved 3D-GRE pulse sequence. 25 3D-volumes were acquired after iv-injection of 0.1 mmol/kg KG Gadolinium-DTPA. Three parameters were determined for each pixel: (1) peak enhancement S n,max normalized to the arterial input function to detect regions of reduced perfusion; (2) time between arterial peak enhancement in the large pulmonary artery and tissue peak enhancement τ to visualize regions with delayed bolus onset; and (3) ratio R = S n,max /τ was calculated to visualize impaired perfusion, irrespectively of whether related to reduced or delayed perfusion. Results: A manual selection of peak perfusion images is not required. Five different types of perfusion can be found: (1) normal perfusion; (2) delayed non-reduced perfusion; (3) reduced non-delayed perfusion; (4) reduced and delayed perfusion; and (5) no perfusion. Types II and IV could not be seen in subtraction images since the temporal information is necessary for this purpose. Conclusions: The analysis strategy in this study allows for a simple and observer-independent visualization and classification of impaired perfusion in dynamic contrast-enhanced pulmonary perfusion MRI by using the temporal information of the datasets.

Ventilation-perfused studies using SPECT

International Nuclear Information System (INIS)

Zwijnenburg, A.

1989-01-01

A method for the quantitative analysis of ventilation-perfusion SPECT studies is decribed and an effort is made to evaluate its usefullness. The technical details of the emthod are described. In the the transaxial reconstructions of the tomographic studies the contour of the lungs is detected and regional values of lung volume, ventilation, perfusion and ventilation-perfusion ratios are calculated. The method is operator independent. The lung volume calculations from the SPECT studies are validated by comparing them with lung volume measurements using the helium dilution technique. A good correlation (r=0.91) was found between the two volumes. SPECT volume was greater than the volume measured with helium dilution, which was attributed to non-gas-containing structures in the. lungs. The use of ventilation-perfusion ratio SPECT is described to evaluate the effect of ionizing radiation on the lungs in patients treated with mantle field irradiation for Hodgkin's disease. Perfusion changes appear as early as 2 months after the start of irradiation. Ventilation changes appear later and relatively minor. No changes are seen outside the radiation portals. The ventilation-perfusion inequality in pulmonary sarcoidosis is treated. It is suggested that the decrease D LCO in these patients may be partly due to an even distribution of ventilation perfusion ratios. An effort is made to establish the properties of a new tracer used for the assessment of the metabolic function of the pulmonary endothelium. The lung uptake of I-123 IMP mimics the distribution of a perfusion tracer and it is suggested that this tracer may be useful for the early detection of pulmonary vascular damage, even when blood flow is still intact. Some aspects of the use of Kr-81m as a ventilation tracer are discussed as well as the effect of noise on Kr-81m SPECT reconstructions. (author). 146 refs.; 39 figs.; 8 tabs

Automatic assessment of cardiac perfusion MRI

DEFF Research Database (Denmark)

Ólafsdóttir, Hildur; Stegmann, Mikkel Bille; Larsson, Henrik B.W.

2004-01-01

In this paper, a method based on Active Appearance Models (AAM) is applied for automatic registration of myocardial perfusion MRI. A semi-quantitative perfusion assessment of the registered image sequences is presented. This includes the formation of perfusion maps for three parameters; maximum up...

Bioartificial liver assist devices in support of patients with liver failure.

Science.gov (United States)

Patzer II, John F; Lopez, Roberto C; Zhu, Yue; Wang, Zi-Fa; Mazariegos, George V; Fung, John J

2002-02-01

Bioartificial liver assist devices (BALs) offer an opportunity for critical care physicians and transplant surgeons to stabilize patients prior to orthotopic liver transplantation. Such devices may also act as a bridge to transplant, providing liver support to patients awaiting transplant, or as support for patients post living-related donor transplant. Four BAL devices that rely on hepatocytes cultured in hollow fiber membrane cartridges (Circe Biomedical HepatAssist(r), Vitagen ELADTM, Gerlach BELS, and Excorp Medical BLSS) are currently in various stages of clinical evaluation. Comparison of the four devices shows that several unique approaches based upon the same overall system architecture are possible. Preliminary results of the Excorp Medical BLSS Phase I safety evaluation at the University of Pittsburgh, after treating four patients (F, 41, acetominophen-induced, two support periods; M, 50, Wilson's disease, one support period; F, 53, acute alcoholic hepatitis, two support periods; F, 24, chemotherapy-induced, one support period, are presented. All patients presented with hypoglycemia and transient hypotension at the start of extracorporeal perfusion. Hypoglycemia was treated by IV dextrose and the transient hypotension responded positively to IV fluid bolus. Heparin anticoagulation was used only in the second patient. No serious or adverse events were noted in the four patients. Moderate Biochemical response to support was noted in all patients. More complete characterization of the safety of the BLSS requires completion of the Phase I safety evaluation.

Can preoperative myocardial perfusion scintigraphy predict changes in left ventricular perfusion and function after coronary artery bypass graft surgery?

DEFF Research Database (Denmark)

Eckardt, Rozy; Kjeldsen, Bo Juel; Johansen, Allan

2012-01-01

OBJECTIVESWe wanted to evaluate whether preoperative myocardial perfusion scintigraphy (MPS) could predict changes in cardiac symptoms and postoperative myocardial perfusion and left ventricular function after coronary artery bypass grafting (CABG).METHODSNinety-two patients with stable angina...... in 26%. Left ventricular ejection fraction (LVEF), which was normal before operation in 45%, improved in 40% of all patients. The increase in LVEF was not related to the preoperative pattern of perfusion defects. Of 30 patients with normalized perfusion after CABG, 29 (97%) had reversible defects...... that reversible or partly reversible perfusion defects at a preoperative MPS have a high chance of normalized myocardial perfusion assessed by MPS 6 months after operation. Normal perfusion is obtained almost exclusively in territories with reversible ischaemia. Symptoms improved in nearly all patients and LVEF...

Sickle cell anemia and mitral valve replacement. Case report.

Science.gov (United States)

Bomfim, V; Ribeiro, A; Gouvea, F; Pereira, J; Björk, V

1989-01-01

An 8-year-old black boy with sickle cell disease and severe hemolytic anemia crisis (95% hemoglobin S) also had mitral incompetence due to rheumatic valve disease. A 27 mm monostrut Björk-Shiley valve prosthesis was implanted after partial exchange transfusions had reduced the hemoglobin S to less than 40%. High-flow normothermic perfusion was used during extracorporeal circulation, with care taken to avoid hypoxia and acidosis. Postoperative recovery was uneventful.

S-Adenosylmethionine and S-adenosylhomocystein metabolism in isolated rat liver. Effects of L-methionine, L-homocystein, and adenosine.

Science.gov (United States)

Hoffman, D R; Marion, D W; Cornatzer, W E; Duerre, J A

1980-11-25

The effects of varying concentrations of L-methionine, L-homocysteine, and adenosine on the tissue levels of S-adenosylmethionine (AdoMet) and S-adenosyl-homocystein (AdoHcy) were investigated in perfused liver. In the normal liver, the intracellular concentration of AdoMet was dependent upon the availability of methionine. In the presence of high concentrations of methionine the maximum level of AdoMet attainable was 300 nmol/g of liver. The exogenous concentration of methionine did not alter the hepatic concentration of AdoHcy (8 to 20 nmol/g) while adenosine or homocysteine blocked hydrolysis of AdoHcy resulting in elevated levels of AdoHcy (400 to 600 nmol/g) and AdoMet (300 to 600 nmol/g). The addition of both adenosine (4mM) and homocysteine (3.4 mM) to the perfusate further increased the levels of AdoHcy (4 mumol/g) and AdoMet (1.2 mumol/g). As the concentration of AdoHcy increased, significant amounts of this compound were released into the perfusate, while AdoMet was not detected. Under all conditions where AdoHcy accumulated in the cell, a concomitant increase in the AdoMet level occurred. Apparently AdoHcy acts as a positive effector of the S-adenosylmethionine synthase. The hepatocytes did not take up significant amounts of [methyl-14C]AdoMet from the perfusate nor were any [14C]methyl groups from this compound incorporated into histones, DNA, or phospholipids. In contrast, [14C]methyl groups were readily incorporated into these macromolecules from exogenous [methyl-14C]methionine. The addition of adenosine (4 mM) and homocystein (3.4 mM) shifted the AdoMet:AdoHcy ratio from 8.2 to 0.3. Under these conditions, transmethylation was inhibited markedly.

Investigation of Hepatic Blood Perfusion by Laser Speckle Imaging and Changes of Hepatic Vasoactive Substances in Mice after Electroacupuncture

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Xiao-jing Song

2014-01-01

Full Text Available The study was conducted to observe the effect of electroacupuncture (EA on hepatic blood perfusion (HBP and vascular regulation. We investigated 60 male anesthetized mice under the following 3 conditions: without EA stimulation (control group; EA stimulation at Zusanli (ST36 group; EA stimulation at nonacupoint (NA group during 30 min. The HBP was measured using the laser speckle perfusion imaging (LSPI. The level of nitric oxide (NO, endothelin-1 (ET-1, and noradrenaline (NE in liver tissue was detected by biochemical methods. Results were as follows. At each time point, HBP increase in ST36 group was higher than that in the NA group in anesthetized mice. HBP gradually decreased during 30 min in control group. The level of NO in ST36 group was higher than that in NA group. The level of both ET-1 and NE was the highest in control group, followed by NA group and ST36 group. It is concluded that EA at ST36 could increase HBP possibly by increasing the blood flow velocity (BFV, changing vascular activity, increasing the level of NO, and inhibiting the level of ET-1 in liver tissue.

Validation of transport measurements in skeletal muscle with N-13 amino acids using a rabbit isolated hindlimb model

International Nuclear Information System (INIS)

Conlon, K.C.; Bading, J.R.; DiResta, G.R.; Corbally, M.T.; Gelbard, A.S.; Brennan, M.F.

1989-01-01

The authors are studying the transport of C-11 and N-13 labeled amino acids in tumor-bearing rabbits to determine the role of amino acid transport in the pathogenesis of muscle wasting in cancer. To validate a new, in vivo, method for measuring transport in skeletal muscle with these compounds, an isolated hindlimb model was developed in rabbits. The limb was perfused with a non-recirculating, normothermic, constant pressure system and a cell-free perfusate. Hemodynamic and metabolic parameters were measured during the first 75 min. of perfusion and found to remain normal and stable. Flow varied directly with perfusion pressure over the normal range of resting flows in the intact rabbit hindlimb. Time-activity curves (TAC's) were recorded from the medial thigh following bolus co-injection of L-[amide N-13] glutamine or N-13 L-glutamate with Tc-99m human serum albumin (HSA) into the femoral artery. Regional plasma flow was determined from the Tc-99m data

Ex Vivo Experiment of Saline-Enhanced Hepatic Bipolar Radiofrequency Ablation with a Perfused Needle Electrode: Comparison with Conventional Monopolar and Simultaneous Monopolar Modes

International Nuclear Information System (INIS)

Lee, Jeong Min; Kim, Se Hyung; Han, Joon Koo; Sohn, Kyu Li; Choi, Byung Ihn

2005-01-01

The purpose of this study was to validate the saline-enhanced bipolar radiofrequency ablation (RFA) technique using a perfused electrode to increase RF-created coagulation necrosis, to compare that technique with monopolar RFAs and to find appropriate concentrations and volumes of perfused NaCl solution for the bipolar RFA. A total of 90 ablations were performed in explanted bovine livers. In the initial experiments to determine appropriate conditions for bipolar RFA, we created five thermal ablation zones in each condition, with instillations of varied concentrations (0.9-36%) or injection rates (30 mL/hr-120 mL/hr) of NaCl solution. After placement of one or two 16-gauge open-perfused electrodes into bovine livers, the NaCl solution was instilled into the tissue through the electrode. In the second part of the study, 10 ablation zones were created using one or two perfused electrodes for each of five groups under different conditions: a conventional monopolar mode with 0.9% NaCl solution (group A) or with 6% NaCl solution (group B), a simultaneous monopolar mode with 6% NaCl solution (group C) and a bipolar mode with 6% NaCl solution (groups D and E). RF was applied to each electrode for 20 min in groups A, B, C, and E, or for 10 min in group D. During RFA, we measured the tissue temperature 15 mm from the electrode. The temperature changes during the RFA and the dimensions of the ablation zones were compared among the groups. Bipolar RFA created larger short-axis diameters of coagulation necrosis with 6% NaCl solution (35.8 ± 15 mm) than with 0.9% NaCl solution (17 ± 9.7 mm) (P 0.05): 31.0 ± 5.4 mm (group A); 28.8 ± 3.8 mm (group B); 25.5 ± 6.4 mm (group C); 32.6 ± 4.2 mm (group D); 49.4 ± 5.0 mm (group E). Bipolar RFA with instillation of 6% NaCl solution through an open perfusion system demonstrates better efficacy in creating a larger ablation zone than does conventional or simultaneous monopolar modes at the various times examined. Therefore

A Study on the Measurement of Intrapulmonary Shunt in Liver Diseases by the Nucleolide Method

International Nuclear Information System (INIS)

Yun, Sung Chul; Ahn, Jae Hee; Choi, Soo Bong

1987-01-01

The fact there are increase of intrapulmonary arteriovenous shunt amount in the liver cirrhosis patient has been known since 1950. And the method of shunt amount calculation by radionuclide method using 99m Tc-MAA was introduced in the middle of 1970. We measured intrapulmonary shunt amount by means of perfusion lung scan using 99m Tc-MAA in the various type of liver diseases especially in chronic liver diseases and acute liver disease. The results were as followed. 1) The amount of arteriovenous intrapulmonary shunt in the total case of liver disease was 9.3±3.9%, and that of in the control group was 4.6±2.1%. 2) The amount of arteriovenous intrapulmonary shunt in the chronic liver disease was 10.8±4.4%, and that of in the acute liver disease was 7.2±2.8%. We observed significant differences between normal control group and liver disease group, and between chronic liver disease group and acute liver disease group in the amount of shunt by the nucleolide method.

Effects of hepatic ischemia-reperfusion injury on the P-glycoprotein activity at the liver canalicular membrane and blood-brain barrier determined by in vivo administration of rhodamine 123 in rats.

Science.gov (United States)

Miah, Mohammad K; Shaik, Imam H; Bickel, Ulrich; Mehvar, Reza

2014-04-01

To investigate the effects of normothermic hepatic ischemia-reperfusion (IR) injury on the activity of P-glycoprotein (P-gp) in the liver and at the blood-brain barrier (BBB) of rats using rhodamine 123 (RH-123) as an in vivo marker. Rats were subjected to 90 min of partial ischemia or sham surgery, followed by 12 or 24 h of reperfusion. Following intravenous injection, the concentrations of RH-123 in blood, bile, brain, and liver were used for pharmacokinetic calculations. The protein levels of P-gp and some other transporters in the liver and brain were also determined by Western blot analysis. P-gp protein levels at the liver canalicular membrane were increased by twofold after 24 h of reperfusion. However, the biliary excretion of RH-123 was reduced in these rats by 26%, presumably due to IR-induced reductions in the liver uptake of the marker and hepatic ATP concentrations. At the BBB, a 24% overexpression of P-gp in the 24-h IR animals was associated with a 30% decrease in the apparent brain uptake clearance of RH-123. The pharmacokinetics or brain distribution of RH-123 was not affected by the 12-h IR injury. Hepatic IR injury may alter the peripheral pharmacokinetics and brain distribution of drugs that are transported by P-gp and possibly other transporters.

Orthotopic liver transplantation for portosystemic encephalopathy in an adult with congenital absence of the portal vein

NARCIS (Netherlands)

Wojcicki, M; Haagsma, EB; Gouw, ASH; Slooff, MJH; Porte, RJ

Congenital absence of the portal vein (CAPV) is a very rare venous malformation in which mesenteric venous blood drains directly into the systemic circulation. There is no portal perfusion of the liver and no portal hypertension. This abnormality is usually coincidentally discovered in children, the

Perfusion based cell culture chips

DEFF Research Database (Denmark)

Heiskanen, Arto; Emnéus, Jenny; Dufva, Martin

2010-01-01

Performing cell culture in miniaturized perfusion chambers gives possibilities to experiment with cells under near in vivo like conditions. In contrast to traditional batch cultures, miniaturized perfusion systems provide precise control of medium composition, long term unattended cultures...... and tissue like structuring of the cultures. However, as this chapter illustrates, many issues remain to be identified regarding perfusion cell culture such as design, material choice and how to use these systems before they will be widespread amongst biomedical researchers....

Brain Perfusion Changes in Intracerebral Hemorrhage

International Nuclear Information System (INIS)

Mititelu, R.; Mazilu, C.; Ghita, S.; Rimbu, A.; Marinescu, G.; Codorean, I.; Bajenaru, O.

2006-01-01

Full text: Purpose: Despite the latest advances in medical treatment and neuro critical care, patients suffering spontaneous intracerebral hemorrhage (SICH) still have a very poor prognosis, with a greater mortality and larger neurological deficits at the survivors than for ischemic stroke. Many authors have shown that there are many mechanisms involved in the pathology of SICH: edema, ischemia, inflammation, apoptosis. All of these factors are affecting brain tissue surrounding hematoma and are responsible of the progressive neurological deterioration; most of these damages are not revealed by anatomical imaging techniques. The aim of our study was to asses the role of brain perfusion SPECT in demonstrating perfusion changes in SICH patients. Method: 17 SICH pts were studied. All pts underwent same day CT and brain SPECT with 99mTcHMPAO, 24h-5d from onset of stroke. Results: 14/17 pts showed a larger perfusion defect than expected after CT. In 2 pts hematoma diameter was comparable on CT and SPECT; 1pt had quasinormal aspect of SPECT study. In pts with larger defects, SPECT revealed a large cold spot with similar size compared with CT, and a surrounding hypo perfused area. 6/17 pts revealed cortical hyper perfusion adjacent to hypo perfused area and corresponding to a normal-appearing brain tissue on CT. In 3 pts we found crossed cerebellar diaskisis.In 2 pts we found cortical hypo perfused area in the contralateral cortex, with normal appearing brain tissue on CT. Conclusions: Brain perfusion SPECT revealed different types of perfusion changes in the brain tissue surrounding hematoma. These areas contain viable brain tissue that may be a target for future ne uroprotective strategies. Further studies are definitely required to demonstrate prognostic significance of these changes, but we can conclude that brain perfusion SPECT can play an important role in SICH, by early demonstrating functional changes responsible of clinical deterioration, thus allowing prompt

Developing a Benchmarking Process in Perfusion: A Report of the Perfusion Downunder Collaboration

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Baker, Robert A.; Newland, Richard F.; Fenton, Carmel; McDonald, Michael; Willcox, Timothy W.; Merry, Alan F.

2012-01-01

Abstract: Improving and understanding clinical practice is an appropriate goal for the perfusion community. The Perfusion Downunder Collaboration has established a multi-center perfusion focused database aimed at achieving these goals through the development of quantitative quality indicators for clinical improvement through benchmarking. Data were collected using the Perfusion Downunder Collaboration database from procedures performed in eight Australian and New Zealand cardiac centers between March 2007 and February 2011. At the Perfusion Downunder Meeting in 2010, it was agreed by consensus, to report quality indicators (QI) for glucose level, arterial outlet temperature, and pCO2 management during cardiopulmonary bypass. The values chosen for each QI were: blood glucose ≥4 mmol/L and ≤10 mmol/L; arterial outlet temperature ≤37°C; and arterial blood gas pCO2 ≥ 35 and ≤45 mmHg. The QI data were used to derive benchmarks using the Achievable Benchmark of Care (ABC™) methodology to identify the incidence of QIs at the best performing centers. Five thousand four hundred and sixty-five procedures were evaluated to derive QI and benchmark data. The incidence of the blood glucose QI ranged from 37–96% of procedures, with a benchmark value of 90%. The arterial outlet temperature QI occurred in 16–98% of procedures with the benchmark of 94%; while the arterial pCO2 QI occurred in 21–91%, with the benchmark value of 80%. We have derived QIs and benchmark calculations for the management of several key aspects of cardiopulmonary bypass to provide a platform for improving the quality of perfusion practice. PMID:22730861

A microvascular compartment model validated using 11C-methylglucose liver PET in pigs

Science.gov (United States)

Munk, Ole L.; Keiding, Susanne; Baker, Charles; Bass, Ludvik

2018-01-01

The standard compartment model (CM) is widely used to analyse dynamic PET data. The CM is fitted to time-activity curves to estimate rate constants that describe the transport of a tracer between well-mixed compartments. The aim of this study was to develop and validate a more realistic microvascular compartment model (MCM) that includes capillary tracer concentration gradients, backflux from cells into the perfused capillaries and multiple re-uptakes during the passage through a capillary. The MCM incorporates only parameters with clear physiological meaning, it is easy to implement, and it does not require numerical solution. We compared the MCM and CM for the analysis of 3 min dynamic PET data of pig livers (N  =  5) following injection of 11C-methylglucose. During PET scans, the tracer concentrations in blood were measured in the abdominal aorta, portal vein and liver vein by manual sampling. We found that the MCM outperformed the CM and that dynamic PET data include information which cannot be extracted using standard CM. The MCM fitted dynamic PET data better than the CM (Akaike values were 46  ±  4 for best MCM fits, and 82  ±  8 for best CM fits; mean  ±  standard deviation) and extracted physiologically reasonable parameter estimates such as blood perfusion that were in agreement with independent measurements. The difference between model-independent perfusion estimates and the best MCM perfusion estimates was  -0.01  ±  0.05 ml/ml/min, whereas the difference was 0.30  ±  0.13 ml/ml/min using the CM. In addition, the MCM predicted the time course of concentrations in the liver vein, a prediction fundamentally unobtainable using the CM as it does not return tracer backflux from cells to capillary blood. The results demonstrate the benefit of using models that include more physiology and that models including concentration gradients should be preferred when analysing the blood-cell exchange of

Preservation of the liver for transplantation: Machine perfusion-based strategies for extended preservation and recovery

NARCIS (Netherlands)

Bruinsma, B.G.

2015-01-01

The field of liver transplantation remains burdened by a severe shortage of donor organs. An important limitation to the use of many livers is the ex vivo preservation of the organ, as maintaining the viability of the donor organ while outside the body is essential for successful transplantation.

Non-contrast MRI perfusion angiosome in diabetic feet

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Zheng, Jie [Cardiovascular Imaging Lab, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Hastings, Mary K.; Mueller, Michael J. [Washington University School of Medicine, The Program in Physical Therapy, St. Louis, MO (United States); Muccigross, David; Hildebolt, Charles F. [Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Fan, Zhaoyang [Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, Los Angeles, CA (United States); Gao, Fabao [West China Hospital, Sichuan University, Department of Radiology, Chengdu (China); Curci, John [Washington University School of Medicine, The Department of Surgery, St. Louis, MO (United States)

2015-01-15

The purpose of this study is to develop a non-contrast magnetic resonance imaging (MRI) approach to evaluate skeletal muscle perfusion in the diabetic foot based on the concept of angiosomes of the foot. Five healthy volunteers and five participants with diabetes (HbA1c = 7.2 ± 1.8 %) without a history of peripheral artery disease were examined. The non-contrast perfusion measurements were performed during a toe flexion challenge. Absolute perfusion maps were created and two regions (medial and lateral) on the maps were segmented based on angiosomes. Regional difference in the perfusion of foot muscle was readily visualized in the MRI perfusion angiosomes during the challenge. In the participants with diabetes, the perfusion during toe flexion challenge was significantly lower than in healthy volunteers (P < 0.01). The average perfusion for the medial plantar region of the right foot was lower in subjects with diabetes (38 ± 9 ml/min/100 g) than in healthy subjects (93 ± 33 ml/min/100 g). Non-contrast MRI perfusion angiosome maps demonstrate the feasibility of determining regional perfusion in foot muscles during toe challenge and may facilitate evaluation of muscle perfusion in diabetic feet. (orig.)

Non-contrast MRI perfusion angiosome in diabetic feet

International Nuclear Information System (INIS)

Zheng, Jie; Hastings, Mary K.; Mueller, Michael J.; Muccigross, David; Hildebolt, Charles F.; Fan, Zhaoyang; Gao, Fabao; Curci, John

2015-01-01

The purpose of this study is to develop a non-contrast magnetic resonance imaging (MRI) approach to evaluate skeletal muscle perfusion in the diabetic foot based on the concept of angiosomes of the foot. Five healthy volunteers and five participants with diabetes (HbA1c = 7.2 ± 1.8 %) without a history of peripheral artery disease were examined. The non-contrast perfusion measurements were performed during a toe flexion challenge. Absolute perfusion maps were created and two regions (medial and lateral) on the maps were segmented based on angiosomes. Regional difference in the perfusion of foot muscle was readily visualized in the MRI perfusion angiosomes during the challenge. In the participants with diabetes, the perfusion during toe flexion challenge was significantly lower than in healthy volunteers (P < 0.01). The average perfusion for the medial plantar region of the right foot was lower in subjects with diabetes (38 ± 9 ml/min/100 g) than in healthy subjects (93 ± 33 ml/min/100 g). Non-contrast MRI perfusion angiosome maps demonstrate the feasibility of determining regional perfusion in foot muscles during toe challenge and may facilitate evaluation of muscle perfusion in diabetic feet. (orig.)

A 3D printed microfluidic perfusion device for multicellular spheroid cultures.

Science.gov (United States)

Ong, Louis Jun Ye; Islam, Anik; DasGupta, Ramanuj; Iyer, Narayanan Gopalakkrishna; Leo, Hwa Liang; Toh, Yi-Chin

2017-09-11

The advent of 3D printing technologies promises to make microfluidic organ-on-chip technologies more accessible for the biological research community. To date, hydrogel-encapsulated cells have been successfully incorporated into 3D printed microfluidic devices. However, there is currently no 3D printed microfluidic device that can support multicellular spheroid culture, which facilitates extensive cell-cell contacts important for recapitulating many multicellular functional biological structures. Here, we report a first instance of fabricating a 3D printed microfluidic cell culture device capable of directly immobilizing and maintaining the viability and functionality of 3D multicellular spheroids. We evaluated the feasibility of two common 3D printing technologies i.e. stereolithography (SLA) and PolyJet printing, and found that SLA could prototype a device comprising of cell immobilizing micro-structures that were housed within a microfluidic network with higher fidelity. We have also implemented a pump-free perfusion system, relying on gravity-driven flow to perform medium perfusion in order to reduce the complexity and footprint of the device setup, thereby improving its adaptability into a standard biological laboratory. Finally, we demonstrated the biological performance of the 3D printed device by performing pump-free perfusion cultures of patient-derived parental and metastatic oral squamous cell carcinoma tumor and liver cell (HepG2) spheroids with good cell viability and functionality. This paper presents a proof-of-concept in simplifying and integrating the prototyping and operation of a microfluidic spheroid culture device, which will facilitate its applications in various drug efficacy, metabolism and toxicity studies.

Dual-energy perfusion-CT of pancreatic adenocarcinoma

International Nuclear Information System (INIS)

Klauß, M.; Stiller, W.; Pahn, G.; Fritz, F.; Kieser, M.; Werner, J.; Kauczor, H.U.; Grenacher, L.

2013-01-01

Purpose: To evaluate the feasibility of dual-energy CT (DECT)-perfusion of pancreatic carcinomas for assessing the differences in perfusion, permeability and blood volume of healthy pancreatic tissue and histopathologically confirmed solid pancreatic carcinoma. Materials and methods: 24 patients with histologically proven pancreatic carcinoma were examined prospectively with a 64-slice dual source CT using a dynamic sequence of 34 dual-energy (DE) acquisitions every 1.5 s (80 ml of iodinated contrast material, 370 mg/ml, flow rate 5 ml/s). 80 kV p , 140 kV p , and weighted average (linearly blended M0.3) 120 kV p -equivalent dual-energy perfusion image data sets were evaluated with a body-perfusion CT tool (Body-PCT, Siemens Medical Solutions, Erlangen, Germany) for estimating perfusion, permeability, and blood volume values. Color-coded parameter maps were generated. Results: In all 24 patients dual-energy CT-perfusion was. All carcinomas could be identified in the color-coded perfusion maps. Calculated perfusion, permeability and blood volume values were significantly lower in pancreatic carcinomas compared to healthy pancreatic tissue. Weighted average 120 kV p -equivalent perfusion-, permeability- and blood volume-values determined from DE image data were 0.27 ± 0.04 min −1 vs. 0.91 ± 0.04 min −1 (p −1 vs. 0.67 ± 0.05 *0.5 min −1 (p = 0.06) and 0.49 ± 0.07 min −1 vs. 1.28 ± 0.11 min −1 (p p the standard deviations of the kV p 120 kV p -equivalent values were manifestly smaller. Conclusion: Dual-energy CT-perfusion of the pancreas is feasible. The use of DECT improves the accuracy of CT-perfusion of the pancreas by fully exploiting the advantages of enhanced iodine contrast at 80 kV p in combination with the noise reduction at 140 kV p . Therefore using dual-energy perfusion data could improve the delineation of pancreatic carcinomas

Characterization of the effects of erythromycin estolate and erythromycin base on the excretory function of the isolated rat liver

International Nuclear Information System (INIS)

Gaeta, G.B.; Utili, R.; Adinolfi, L.E.; Abernathy, C.O.; Giusti, G.

1985-01-01

To investigate the mechanisms of erythromycin cholestasis, the effects of erythromycin estolate (EE) on the excretory function of the isolated perfused rat liver and on liver plasma membrane (LM) preparations were studied and compared to those of erythromycin base (EB) and lauryl sulfate (LS), added alone or in combination. EE (at 125 to 200 microM) caused dose-dependent reductions of bile and perfusate flows, bile acid (BA) excretion, and biliary BA concentration. The alterations of the excretory function were only in part due to the decreased perfusate flow. In contrast, both 200 and 300 microM concentrations of EB elicited similar choleretic responses, which were presumably related to the osmotic activity of the drug excreted in the bile. LS did not affect hepatic excretory functions. However, the simultaneous addition of EB and LS resulted in a rate of bile flow lower than that observed with EB alone. EE, but not EB, increased canalicular permeability to [ 14 C]sucrose as measured by bile to plasma (B:P) ratio. Neither drugs altered [ 14 C]erythritol B:P ratio. In LM preparations both Na+,K+- and Mg2+-ATPase activities were inhibited in a dose-dependent manner by EE, but not by EB. The data suggest that EE could affect bile flow by inhibiting cotransport of Na+ and BA and by altering LM permeability and support the view that the effect of erythromycins on the liver may be related to their surface activity

Severe Juxtahepatic Venous Injury: Survival after Prolonged Hepatic Vascular Isolation Without Shunting

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J. E. J. Krige

1990-01-01

Full Text Available Survival following major juxtahepatic venous injury is rare in blunt liver trauma despite the use of intracaval shunting. Prolonged liver arterial inflow control, total hepatic venous isolation and lobectomy without shunting was used in a patient to repair a combined vena caval and hepatic venous injury after blunt liver injury. An extended period of normothermic hepatic ischemia was tolerated. Early recognition of retrohepatic venous injury and temporary liver packing to control bleeding and correct hypovolemia are essential before caval occlusion. Hepatic vascular isolation without shunting is an effective simple alternative technique allowing major venous repair in complex liver trauma.

In-vivo quantitative evaluation of perfusion zones and perfusion gradient in the deep inferior epigastric artery perforator flap

Science.gov (United States)

Saint-Cyr, Michel; Lakhiani, Chrisovalantis; Cheng, Angela; Mangum, Michael; Liang, Jinyang; Teotia, Sumeet; Livingston, Edward H.; Zuzak, Karel J.

2013-03-01

The selection of well-vascularized tissue during DIEP flap harvest remains controversial. While several studies have elucidated cross-midline perfusion, further characterization of perfusion to the ipsilateral hemiabdomen is necessary for minimizing rates of fat necrosis or partial fat necrosis in bilateral DIEP flaps. Eighteen patients (29 flaps) underwent DIEP flap harvest using a prospectively designed protocol. Perforators were marked and imaged with a novel system for quantitatively measuring tissue oxygenation, the Digital Light Hyperspectral Imager. Images were then analyzed to determine if perforator selection influenced ipsilateral flap perfusion. Flaps based on a single lateral row perforator (SLRP) were found to have a higher level of hemoglobin oxygenation in Zone I (mean %HbO2 = 76.1) compared to single medial row perforator (SMRP) flaps (%HbO2 = 71.6). Perfusion of Zone III relative to Zone I was similar between SLRP and SMRP flaps (97.4% vs. 97.9%, respectively). These differences were not statistically significant (p>0.05). Perfusion to the lateral edge of the flap was slightly greater for SLRP flaps compared SMRP flaps (92.1% vs. 89.5%, respectively). SMRP flaps had superior perfusion travelling inferiorly compared to SLRP flaps (88.8% vs. 83.9%, respectively). Overall, it was observed that flaps were better perfused in the lateral direction than inferiorly. Significant differences in perfusion gradients directed inferiorly or laterally were observed, and perforator selection influenced perfusion in the most distal or inferior aspects of the flap. This suggests broader clinical implications for flap design that merit further investigation.

Obtaining liver tridimensional scaffold through the decellularization of rabbit whole liver in 24 hours

Science.gov (United States)

Federico, Schliamser; Ayelen, Rinaldi; Romina, Comin; Alba Nelly, Borchert; Adrian, Nari Gustavo; Alicia, Salvatierra Nancy; Mariana Paula, Cid

2016-04-01

In the present work, we development a new protocol for liver decellularization in which the hole decellularization was reached over 24 h. Introduction: the availability of transplantable livers is not sufficient to fulfill the current demand for grafts, with the search for therapeutic alternatives having generated different lines of research, one of which is the use of decellularized three-dimensional biological matrices and subsequent cell seeding to obtain a functional organ. Objective: to produce a decellularization protocol from rabbit liver to generate a three-dimensional matrixin which the time period involved didn't pass 24 h. Methods: The decellularization is obtained through the use of water and SDS (0,1-0,3 %), after freezing at -80 degrees, is the best alternative of different physical and/or chemical mechanisms to break down organ cells and leave only the extracellular matriz. After 24 h of retrograde perfusion, a decellularized translucent matrix was generated. To evaluate if the decellularization protocol was successful, with the extracellular matrix being preserved, we carried out histological (light microscopy) and biochemical (DNA quantification) studies. Results: the decellularization process was verified by macroscopic observation of the organ using microscopic observation corroborated the macroscopic results, with the hematoxylin-eosin and Masson staining showing no cells or nuclear material. In addition, the DNA quantification was less than 10% in the decellularized liver compared to control. Finally,the time taken to develop the decellularization protocol was less than 24 hours.

Obtaining liver tridimensional scaffold through the decellularization of rabbit whole liver in 24 hours

International Nuclear Information System (INIS)

Federico, Schliamser; Ayelen, Rinaldi; Romina, Comin; Alicia, Salvatierra Nancy; Paula, Cid Mariana; Nelly, Borchert Alba; Adrian, Nari Gustavo

2016-01-01

In the present work, we development a new protocol for liver decellularization in which the hole decellularization was reached over 24 h. Introduction: the availability of transplantable livers is not sufficient to fulfill the current demand for grafts, with the search for therapeutic alternatives having generated different lines of research, one of which is the use of decellularized three-dimensional biological matrices and subsequent cell seeding to obtain a functional organ. Objective: to produce a decellularization protocol from rabbit liver to generate a three-dimensional matrixin which the time period involved didn't pass 24 h. Methods: The decellularization is obtained through the use of water and SDS (0,1-0,3 %), after freezing at -80 degrees, is the best alternative of different physical and/or chemical mechanisms to break down organ cells and leave only the extracellular matriz. After 24 h of retrograde perfusion, a decellularized translucent matrix was generated. To evaluate if the decellularization protocol was successful, with the extracellular matrix being preserved, we carried out histological (light microscopy) and biochemical (DNA quantification) studies. Results: the decellularization process was verified by macroscopic observation of the organ using microscopic observation corroborated the macroscopic results, with the hematoxylin-eosin and Masson staining showing no cells or nuclear material. In addition, the DNA quantification was less than 10% in the decellularized liver compared to control. Finally,the time taken to develop the decellularization protocol was less than 24 hours. (paper)

Pulmonary dysfunction in advanced liver disease: frequent occurrence of an abnormal diffusing capacity

International Nuclear Information System (INIS)

Hourani, J.M.; Bellamy, P.E.; Tashkin, D.P.; Batra, P.; Simmons, M.S.

1991-01-01

Abnormalities in pulmonary function have been reported in association with chronic liver disease of varied etiology. The aim of this study was to better define the frequency and nature of these abnormalities in patients who were being evaluated for liver transplantation. We performed a battery of pulmonary function tests and chest radiographs in 116 consecutive patients (50 men, 66 women; aged 19 to 70 years, mean 44.6 years) with severe advanced liver disease who were hospitalized specifically for evaluation for possible orthotopic liver transplantation and were able to perform technically satisfactory tests. In 17 patients, quantitative whole-body technetium-99m macroaggregated albumin perfusion scanning was also performed for assessment of possible right-to-left shunting through intrapulmonary vascular dilatations. The most commonly affected test of lung function was the single-breath diffusing capacity for carbon monoxide (DLCO), which was abnormal in 48%, 45%, and 71% of patients who never smoked, former smokers, and current smokers, respectively. Ventilatory restriction was noted in 25% of all patients, airflow obstruction (reduced ratio of forced expiratory volume in 1 second to forced vital expiratory volume in 1 second to forced vital capacity) in only 3%, and a widened alveolar-arterial oxygen gradient in 45%. Diffusion impairment was accompanied by a restrictive defect in only 35% of the patients and by an abnormally widened alveolar-arterial oxygen gradient in 60%. When diffusion impairment was accompanied by an oxygenation defect, it was also associated with a significantly increased right-to-left shunt fraction (mean 24.9%) assessed from quantitative whole-body perfusion imaging

Perfusion vector - a new method to quantify myocardial perfusion scintigraphy images: a simulation study with validation in patients

DEFF Research Database (Denmark)

Minarik, David; Senneby, Martin; Wollmer, Per

2015-01-01

Background The interpretation of myocardial perfusion scintigraphy (MPS) largely relies on visual assessment by the physician of the localization and extent of a perfusion defect. The aim of this study was to introduce the concept of the perfusion vector as a new objective quantitative method...

Placental perfusion - a human alternative

DEFF Research Database (Denmark)

Mose, Tina; Knudsen, Lisbeth E

2006-01-01

Foetal exposures to environmental and medicinal products have impact on the growth of the foetus (e.g. cigarette smoke) and development of organs (e.g. methylmercury and Thalidomide). Perfusion studies of the human term placenta enable investigation of placental transport of chemical substances...... between the mother and foetus. Dual perfusion of a single cotyledon in the human placenta can contribute to a better understanding of the placental barrier, transport rate and mechanisms of different substances and placental metabolism. The perfusion system has recently been established in Copenhagen...

Development of 99Tcm-Q3 as a new type myocardial perfusion imaging agent

International Nuclear Information System (INIS)

Li Yunchun; Tan Tianzhi; Fan Chengzhong; Zhao Keqing; Wei Xihe; Li Quan

1999-01-01

Objective: To develop 99 Tc m -N,N'-ethylene-bis (acetylacetone iminato) bis [tris (3-methoxy-1-propyl) phosphine] ( 99 Tc m -Q 3 ) as a new type of myocardial perfusion imaging agent. Methods: After N,N'-ethylene-bis (acetylacetone iminato) and tris (3-methoxy-1-propyl) phosphine were made, N,N'-ethylene-bis (acetylacetone iminato) was labelled using reduced 99 Tc m O 4 - by SnCl 2 ·2H 2 O under the presence of alkali, then tris (3-methoxy-1-propyl) phosphine was added and reacted for ten minutes, 99 Tc m -Q 3 was obtained at the end. Biodistribution in mice, in vitro stability and acute toxicity of 99 Tc m -Q 3 were examined. Results: 99 Tc m -Q 3 was taken up rapidly by the heart, and the uptake rate was very high, by 5 minutes post injection, 24.66% of the injected dose was taken up in per gram heart, and no significant washout was shown up by 4 hours. But 99 Tc m -Q 3 was cleaned out rapidly from blood, lung and liver. No poisonousness and adverse effects were observed, and its stability lasted more than 6 hours. Conclusions: 99 Tc m -Q 3 is a fairly good myocardial perfusion imaging agent for improving the quality of myocardial perfusion imaging

Vicarious audiovisual learning in perfusion education.

Science.gov (United States)

Rath, Thomas E; Holt, David W

2010-12-01

Perfusion technology is a mechanical and visual science traditionally taught with didactic instruction combined with clinical experience. It is difficult to provide perfusion students the opportunity to experience difficult clinical situations, set up complex perfusion equipment, or observe corrective measures taken during catastrophic events because of patient safety concerns. Although high fidelity simulators offer exciting opportunities for future perfusion training, we explore the use of a less costly low fidelity form of simulation instruction, vicarious audiovisual learning. Two low fidelity modes of instruction; description with text and a vicarious, first person audiovisual production depicting the same content were compared. Students (n = 37) sampled from five North American perfusion schools were prospectively randomized to one of two online learning modules, text or video.These modules described the setup and operation of the MAQUET ROTAFLOW stand-alone centrifugal console and pump. Using a 10 question multiple-choice test, students were assessed immediately after viewing the module (test #1) and then again 2 weeks later (test #2) to determine cognition and recall of the module content. In addition, students completed a questionnaire assessing the learning preferences of today's perfusion student. Mean test scores from test #1 for video learners (n = 18) were significantly higher (88.89%) than for text learners (n = 19) (74.74%), (p audiovisual learning modules may be an efficacious, low cost means of delivering perfusion training on subjects such as equipment setup and operation. Video learning appears to improve cognition and retention of learned content and may play an important role in how we teach perfusion in the future, as simulation technology becomes more prevalent.

Unusual Case of Severe Lactic Acidosis in a Liver Transplant Patient

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Shweta Yemul Golhar

2017-01-01

Full Text Available Lactic acidosis is a standard indicator for oxygen debt and some other very significant causes. We describe a case of liver transplant patient presenting with vague abdominal pain and lactic acidosis without any liver dysfunction/failure/ischemia/rejection or sepsis. The imaging studies showed vague bowel edema and normal hepatic perfusion. The patient continued to deteriorate with rising lactic acidosis when a repeat CT abdomen eventually showed signs of lymphomatosis peritonei. Biopsy revealed the unusual diagnosis of posttransplant lymphoproliferative disorder. Immediate discontinuation of immunosuppression and initiation of chemotherapy led to clinical improvement. Our intention of presenting this case is to increase awareness of posttransplant lymphoma and propose lactic acidosis as not only an indicator of liver dysfunction or rejection but also an aid for diagnosis of this unusual but fatal and potentially curable condition.

Pulmonary ventilation and perfusion abnormalities and ventilation perfusion imbalance in children with pulmonary atresia or extreme tetralogy of Fallot

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Dowdle, S.C.; Human, D.G.; Mann, M.D. (Univ. of Cape Town (South Africa))

1990-08-01

Xenon-133 lung ventilation and perfusion scans were done preoperatively after cardiac catheterization and cineangiocardiography in 19 children; 6 had pulmonary atresia with an intact ventricular septum and hypoplastic right ventricle, 4 pulmonary atresia with associated complex univentricular heart, and 9 extreme Tetralogy of Fallot. The four patients with discrepancies in the sizes of the left and right pulmonary arteries on angiography had marked asymmetry of pulmonary perfusion and ventilation-perfusion imbalance on scintigraphy. Similar degrees of asymmetry and imbalance were present in 6 of the 15 children with equal-size pulmonary vessels. Asymmetry of pulmonary perfusion and ventilation-perfusion imbalance were associated with a poor prognosis.

Pulmonary ventilation and perfusion abnormalities and ventilation perfusion imbalance in children with pulmonary atresia or extreme tetralogy of Fallot

International Nuclear Information System (INIS)

Dowdle, S.C.; Human, D.G.; Mann, M.D.

1990-01-01

Xenon-133 lung ventilation and perfusion scans were done preoperatively after cardiac catheterization and cineangiocardiography in 19 children; 6 had pulmonary atresia with an intact ventricular septum and hypoplastic right ventricle, 4 pulmonary atresia with associated complex univentricular heart, and 9 extreme Tetralogy of Fallot. The four patients with discrepancies in the sizes of the left and right pulmonary arteries on angiography had marked asymmetry of pulmonary perfusion and ventilation-perfusion imbalance on scintigraphy. Similar degrees of asymmetry and imbalance were present in 6 of the 15 children with equal-size pulmonary vessels. Asymmetry of pulmonary perfusion and ventilation-perfusion imbalance were associated with a poor prognosis

Clinical application of cerebral dynamic perfusion studies

International Nuclear Information System (INIS)

DeLand, F.H.

1975-01-01

Radionuclide cerebral perfusion studies are assuming a far greater importance in the detection and differential diagnosis of cerebral lesions. Perfusion studies not only contribute to the differential diagnosis of lesions but in certain cases are the preferred methods by which more accurate clinical interpretations can be made. The characteristic blood flow of arterio-venous malformations readily differentiates this lesion from neoplasms. The decreased perfusion or absent perfusion observed in cerebral infarctions is diagnostic without concurrent evidence from static images. Changes in rates and direction of blood flow contribute fundamental information to the status of stenosis and vascular occlusion and, in addition, offer valuable information on the competency and routes of collateral circulation. The degree of cerebral perfusion after cerebral vascular accidents appears to be directly related to patient recovery, particularly muscular function. Cerebral perfusion adds a new parameter in the diagnosis of subdural haematomas and concussion and in the differentiation of obscuring radioactivity from superficial trauma. Although pictorial displays of perfusion blood flow will offer information in most cerebral vascular problems, the addition of computer analysis better defines temporal relationships of regional blood flow, quantitative changes in flow and the detection of the more subtle increases or decreases in cerebral blood flow. The status of radionuclide cerebral perfusion studies has taken on an importance making it the primary modality for the diagnosis of cerebral lesions. (author)

Combined static and perfusion scintigraphy for differential diagnosis of focal and diffuse affections of the liver

International Nuclear Information System (INIS)

Yakovleva, L.Ya.; Volkov, A.A.; Granov, A.M.; Borisov, A.E.

1985-01-01

Combined application of dynamic and static scintigraphy is recommended by use of /sup 99m/Tc-pertechnetate, /sup 113m/In-chloride, /sup 99m/Tc-sulphur colloid, /sup 119m/In-colloid, and 67 Ga-citrate, respectively, to detect diffuse and focal affections of the liver. In patients with abscesses, echinococcus, or a cyst of the liver the blood supply in the tumor decreased tremendously or was not perceivable at all. In primary or secondary tumors the blood supply was decreased in focus, the half-life period of the preparation storage was extended, and the reception speed was decreased by 50% at most. The alteration of quantitative blood supply values by 150 - 200% and the prevalence of arterial components in liver blood supply for all segments can be considered a sign of cirrhotic liver damage. (author)

Whole-body imaging of whole-organ, subresolution, basic functional unit (BFU) perfusion characteristics

Science.gov (United States)

Dong, Yue; Ritman, Erik L.

2008-08-01

A BFU is an organ's smallest assembly of diverse cells that functions like the organ, such as the liver's hepatic lobules. There are approximately 107 BFUs in a human organ. These 100-200 μm structures are perfused by capillaries fed by a terminal arteriole (15μm diameter). BFU sizes, function and number per organ vary with disease, either by loss of BFUs and/or their decrease in function. The BFU is the upper limit of a spherical assembly of cells, immersed in a suitably nutrient medium, which can survive without its own blood supply. However, each BFU has its own blood supply to support the extra energy and/or solutes needed for providing its physiological function (e.g., contraction or secretion). A BFU function is best evaluated by its micro-perfusion, which can be readily evaluated with whole-body CT. Resolution of individual BFUs within in-situ organs, using clinical imaging devices, would require high radiation doses and/or the intolerably long scan-durations needed for suitable signal-to-noise image-data. However, it is possible to obtain a statistical description of the BFU number, size and function from wholebody CT by way of a model. In this study we demonstrate this capability by using the distribution of myocardial terminal arteriolar perfusion territories by way of a nested, multiple, regions-of-interest analysis of the heart wall imaged during transient opacification of its blood supply.

Angiotensin extraction by trout tissues in vivo and metabolism by the perfused gill

International Nuclear Information System (INIS)

Olson, K.R.; Kullman, D.; Narkates, A.J.; Oparil, S.

1986-01-01

Plasma clearance and tissue accumulation of 125I-angiotensin I, [Asp1, Ile5]ANG I, and [14C]sucrose, an inert volume reference, were measured after a bolus injection into the dorsal aorta of rainbow trout, Salmo gairdneri. Retention and metabolism of ANG I to angiotensin II (ANG II) and their constituent 1-4 peptide by the gill were examined using an isolated perfused arch preparation in which outflow from the respiratory and central filamental (venous) pathways was separated. Clearance of ANG I from plasma is multiexponential, reflecting dilution and tissue extraction. Liver, bile, gonads, corpuscles of Stannius, and white skeletal muscle accumulate more 125I than 14C; gill tissue accumulates less 125I than 14C. ANG I and II are retained by the perfused gill longer than the inert vascular marker sucrose, even though the distribution volumes of the former are less. The gill respiratory pathway converts ANG I to ANG II whereas the venous pathway metabolizes either ANG I or II to the 1-4 peptide and other metabolites. The gill respiratory pathway is in series with the systemic vasculature, has a large blood-cell contact area, and, like the mammalian lung, is ideally suited to activate ANG I. The gill venous pathway is in parallel with the systemic vasculature and removes ANG II from the circulation. During stress, elevated plasma catecholamines may reduce venous perfusion and thereby help maintain elevated circulating ANG II levels through reduced venous metabolism

Hemodynamic changes in liver measured by multi-imaging methods before and after transjugular intrahepatic portosystemic stent-shunt

International Nuclear Information System (INIS)

Huang Yonghui; Chen Wei; Li Jiaping; Zhuang Wenquan; Li Ziping; Yang Jianyong

2007-01-01

Objective: To evaluate hemodynamic changes in liver treated by transjugular intrahepatic portosystemic stent-shunt (TIPSS) with hepatic computed tomography (CT) perfusion, Doppler ultrasound and portal vein pressure measurement, as well as the correlation among these methods. Methods: Hepatic CT perfusion was performed in 9 cirrhotic patients one week before TIPSS and 72 hours after TIPSS. Intraoperative portal vein pressure was measured before and after portosystemic shunt establish. The follow- up hepatic CT perfusion were carried out in 3 cases at 3 months and 6 months postoperatively. The hemodynamic surveillance by Doppler ultrasound were performed in 48 hours and 3 months after TIPSS for 9 cases, and in 6 months after TIPSS for 6 cases. Two cases underwent venography and portal vein pressure measurement in 6 months after TIPSS treatment. Results: The mean of portal vein perfusion (PVP), total hepatic blood flow (THBF), hepatic perfusion index (HPI) and portal vein free pressure (PVFP) before TIPSS were (0.92 ± 0.18) ml·min·ml -1 , (1.28±0.17) ml·min -1 ·ml -1 , (28 ± 8)%, and (23.92±0.86) mmHg, respectively. In 72 hours after TIPSS, the mean of PVP, THBF, HPI and PVFP were (0.21 ± 0.15) ml·min -1 ·ml -1 , (0.74 ± 0.18) ml·min -1 ·ml -1 , (74±13)%, and (12.62±1.54) mm Hg, respectively. After treatment, the mean of PVP was (0.49±0.05) ml·min -1 ·ml -1 at 3 months and (0.57±0.03) ml·min -1 ·ml -1 at 6 months, respectively. There was negative correlation between PVP and PVFP before TIPSS (r= 0.678, P 0.05). Moreover, a significant correlation was found between the degree of portal vein pressure decrease and portal vein perfusion decrease (r=0.867, P 3 /s was not less than that of main portal vein (9.83±5.72) cm 3 /s until six months after treatment. Conclusion: The portal vein pressure obviously decreased after TIPSS, and meanwhile, most blood flow of portal vein passed through portosystemic stent shunt without liver parenchyma perfusion

Dynamic perfusion CT: Optimizing the temporal resolution for the calculation of perfusion CT parameters in stroke patients

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Kaemena, Andreas [Department of Radiology, Charite-Medical University Berlin, Augustenburger Platz 1, D-13353 Berlin (Germany)], E-mail: andreas.kaemena@charite.de; Streitparth, Florian; Grieser, Christian; Lehmkuhl, Lukas [Department of Radiology, Charite-Medical University Berlin, Augustenburger Platz 1, D-13353 Berlin (Germany); Jamil, Basil [Department of Radiotherapy, Charite-Medical University Berlin, Schumannstr. 20/21, D-10117 Berlin (Germany); Wojtal, Katarzyna; Ricke, Jens; Pech, Maciej [Department of Radiology, Charite-Medical University Berlin, Augustenburger Platz 1, D-13353 Berlin (Germany)

2007-10-15

Purpose: To assess the influence of different temporal sampling rates on the accuracy of the results from cerebral perfusion CTs in patients with an acute ischemic stroke. Material and methods: Thirty consecutive patients with acute stroke symptoms received a dynamic perfusion CT (LightSpeed 16, GE). Forty millilitres of iomeprol (Imeron 400) were administered at an injection rate of 4 ml/s. After a scan delay of 7 s, two adjacent 10 mm slices at 80 kV and 190 mA were acquired in a cine mode technique with a cine duration of 49 s. Parametric maps for the blood flow (BF), blood volume (BV) and mean transit time (MTT) were calculated for temporal sampling intervals of 0.5, 1, 2, 3 and 4 s using GE's Perfusion 3 software package. In addition to the quantitative ROI data analysis, a visual perfusion map analysis was performed. Results: The perfusion analysis proved to be technically feasible with all patients. The calculated perfusion values revealed significant differences with regard to the BF, BV and MTT, depending on the employed temporal resolution. The perfusion contrast between ischemic lesions and healthy brain tissue decreased continuously at the lower temporal resolutions. The visual analysis revealed that ischemic lesions were best depicted with sampling intervals of 0.5 and 1 s. Conclusion: We recommend a temporal scan resolution of two images per second for the best detection and depiction of ischemic areas.

Characteristics of Brain Perfusion in Patients of Parkinson's Disease

International Nuclear Information System (INIS)

Jeong, Young Jin; Park, Min Jung; Kim, Jae Woo; Kang, Young Kang

2008-01-01

It was well known that cerebral blood perfusion is normal or diffusely decreased in the majority of patients with Parkinson's disease (PD). Actually we interpreted brain perfusion SPECT images of PD patients in the clinical situation, we observed various cerebral perfusion patterns in patients with PD. So we performed brain perfusion SPECT to know the brain perfusion patterns of PD patients and the difference of perfusion patterns according to the sex and the age. Also we classified PD patients into small groups based on the brain perfusion pattern. Two hundred nineteen patients (M: 70, F: 149, mean age: 62.9±6.9 y/o) who were diagnosed as PD without dementia clinically and 55 patients (M: 15, F: 40, mean age: 61.4±9.2 y/o) as normal controls who had no past illness history were performed 99m Tc-HMPAO brain perfusion SPECT and neuropsychological test. At first, we compared all patients with PD and normal controls. Brain perfusion in left inferior frontal gyrus, left insula, left transverse temporal gyrus, left inferior parietal lobule, left superior parietal lobule, right precuneus, right caudate tail were lower in patients with PD than normal controls. Secondly, we compared male and female patients with PD and normal controls, respectively. Brain perfusion SPECT showed more decreased cerebral perfusion in left hemisphere than right side in both male and female patients compared to normal controls. And there was larger hypoperfusion area in female patients compared with male. Thirdly, we classified patients with PD and normal controls into 4 groups according to the age and compared brain perfusion respectively. In patient below fifties, brain perfusion in both occipitoparietal and left temporal lobe were lower in PD group. As the patients with PD grew older, hypoperfusion area were shown in both frontal, temporal and limbic lobes. Fourthly, We were able to divide patients into small groups based on cerebral perfusion pattern. There was normal cerebral blood

Regional Cerebral Perfusion in Progressive Supranuclear Palsy

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Lee, Won Yong; Lee, Ki Hyeong; Yoon, Byung Woo; Lee, Sang Bok; Jeon, Beom S. [Samsung Medical Center, Seoul (Korea, Republic of); Lee, Kyung Han; Lee, Myung Chul [Seoul National University College of Medicine, Seoul (Korea, Republic of)

1996-03-15

Progressive supranuclear palsy (PSP) is a Parkinson-plus syndrome characterized clinically by supranuclear ophthalmoplegia, pseudobulbar palsy, axial rigidity, bradykinesia, postural instability and dementia. Presence of dementia and lack of cortical histopathology suggest the derangement of cortical function by pathological changes in subcortical structures in PSP, which is supported by the pattern of behavioral changes and measurement of brain metabolism using positron emission tomography. This study was done to examine whether there are specific changes of regional cerebral perfusion in PSP and whether there is a correlation between severity of motor abnormaility and degree of changes in cerebral perfusion. We measured regional cerebral perfusion indices in 5 cortical and 2 subcortical areas in 6 patients with a clinical diagnosis of PSP and 6 healthy age and sex matched controls using Tc-99m-HMPAO SPECT. Compared with age and sex matched controls, only superior frontal regional perfusion index was significantly decreased in PSP (p<0.05). There was no correlation between the severity of the motor abnormality and any of the regional cerebral perfusion indices (p>0.05). We affirm the previous reports that perfusion in superior frontal cortex is decreased in PSP. Based on our results that there was no correlation between severity of motor abnormality and cerebral perfusion in the superior frontal cortex, nonmotoric symptoms including dementia needs to be looked at whether there is a correlation with the perfusion abnormality in superior frontal cortex

Regional perfusion by extracorporeal membrane oxygenation of abdominal organs from donors after circulatory death: a systematic review.

Science.gov (United States)

Shapey, Iestyn M; Muiesan, Paolo

2013-12-01

Organs from donors after circulatory death (DCDs) are particularly susceptible to the effects of warm ischemia injury. Regional perfusion (RP) by extracorporeal membrane oxygenation (ECMO) is increasingly being advocated as a useful remedy to the effects of ischemia/reperfusion injury, and it has been reported to enable the transplantation of organs from donors previously deemed unsuitable. The MEDLINE, Embase, and Cochrane databases were searched, and articles published between 1997 and 2013 were obtained. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Two hundred ten articles were identified, and 11 were eligible for inclusion. Four hundred eighty-two kidneys and 79 livers were transplanted from regional perfusion-supported donor after circulatory death (RP-DCD) sources. One-year graft survival was lower with uncontrolled RP-DCD liver transplantation, whereas 1-year patient survival was similar. Primary nonfunction and ischemic cholangiopathy were significantly more frequent with RP-DCDs versus donors after brain death (DBDs), but there was no difference in postoperative mortality between the 2 groups. The 1-year patient and graft survival rates for RP-DCD kidney transplantation were better than the rates with standard DCDs and were comparable to, if not better than, the rates with DBDs. At experienced centers, delayed graft function (DGF) for kidney transplantation from RP-DCDs was much less frequent in comparison with all other donor types. In conclusion, RP aids the recovery of DCD organs from ischemic injury and enables transplantation with acceptable survival. RP may help to increase the donor pool, but its benefits must still be balanced with the recognition of significantly higher rates of complications in liver transplantation. In kidney transplantation, significant reductions in DGF can be obtained with RP, and there are potentially important implications for long

Regional Cerebral Perfusion in Progressive Supranuclear Palsy

International Nuclear Information System (INIS)

Lee, Won Yong; Lee, Ki Hyeong; Yoon, Byung Woo; Lee, Sang Bok; Jeon, Beom S.; Lee, Kyung Han; Lee, Myung Chul

1996-01-01

Progressive supranuclear palsy (PSP) is a Parkinson-plus syndrome characterized clinically by supranuclear ophthalmoplegia, pseudobulbar palsy, axial rigidity, bradykinesia, postural instability and dementia. Presence of dementia and lack of cortical histopathology suggest the derangement of cortical function by pathological changes in subcortical structures in PSP, which is supported by the pattern of behavioral changes and measurement of brain metabolism using positron emission tomography. This study was done to examine whether there are specific changes of regional cerebral perfusion in PSP and whether there is a correlation between severity of motor abnormaility and degree of changes in cerebral perfusion. We measured regional cerebral perfusion indices in 5 cortical and 2 subcortical areas in 6 patients with a clinical diagnosis of PSP and 6 healthy age and sex matched controls using Tc-99m-HMPAO SPECT. Compared with age and sex matched controls, only superior frontal regional perfusion index was significantly decreased in PSP (p 0.05). We affirm the previous reports that perfusion in superior frontal cortex is decreased in PSP. Based on our results that there was no correlation between severity of motor abnormality and cerebral perfusion in the superior frontal cortex, nonmotoric symptoms including dementia needs to be looked at whether there is a correlation with the perfusion abnormality in superior frontal cortex

Computerized analysis of brain perfusion parameter images

International Nuclear Information System (INIS)

Turowski, B.; Haenggi, D.; Wittsack, H.J.; Beck, A.; Aurich, V.

2007-01-01

Purpose: The development of a computerized method which allows a direct quantitative comparison of perfusion parameters. The display should allow a clear direct comparison of brain perfusion parameters in different vascular territories and over the course of time. The analysis is intended to be the basis for further evaluation of cerebral vasospasm after subarachnoid hemorrhage (SAH). The method should permit early diagnosis of cerebral vasospasm. Materials and Methods: The Angiotux 2D-ECCET software was developed with a close cooperation between computer scientists and clinicians. Starting from parameter images of brain perfusion, the cortex was marked, segmented and assigned to definite vascular territories. The underlying values were averages for each segment and were displayed in a graph. If a follow-up was available, the mean values of the perfusion parameters were displayed in relation to time. The method was developed under consideration of CT perfusion values but is applicable for other methods of perfusion imaging. Results: Computerized analysis of brain perfusion parameter images allows an immediate comparison of these parameters and follow-up of mean values in a clear and concise manner. Values are related to definite vascular territories. The tabular output facilitates further statistic evaluations. The computerized analysis is precisely reproducible, i. e., repetitions result in exactly the same output. (orig.)

Assessment of myocardial perfusion using a new scanning agent

Energy Technology Data Exchange (ETDEWEB)

Khalil, M.N

1987-01-01

This work assessed a new compound: Tc-99m tertiary butyl isonitrile (T-BIN) in scanning the normal myocardium in dogs. Experimentally induced myocardial infarcts (M.I.) were detected. The compound cleared significantly from the blood within 15 minutes and from the lungs within an hour after intravenous administration. Liver uptake was high and remained so. Cardiac uptake occurred quickly and continued for 6 hours. Comparable results were obtained in normal humans and patients. Myocardial scanning was best after 60 minutes at rest or 30 minutes after exercise. Liver uptake sometimes obscured the detection of inferior M.I. but this problem was reduced using a 45/sup 0/ left anterior oblique view with a 20/sup 0/ cranial tilt. At rest 9/10 patients with M.I. showed defects corresponding to the infarct sites. In 20 patients with angina pectoris 16 had perfusion defects on exercise. In 15/16 patients reversible ischaemia was demonstrated. The reperfusion scans were best obtained at 4 hours post exercise. Both Tl-201 and T-BIN detected equally the infarcts (3/3) but in patients with angina 8/10 with T-BIN and 6/10 with Tl-201 showed defects. ECG gating of the T-BIN scans was also studied.

Chemosaturation with Percutaneous Hepatic Perfusion for Unresectable Isolated Hepatic Metastases from Sarcoma

Energy Technology Data Exchange (ETDEWEB)

Deneve, Jeremiah L., E-mail: Jeremiah.Deneve@Moffitt.org [Moffitt Cancer Center, Department of Cutaneous and Sarcoma Oncology (United States); Choi, Junsung [Moffitt Cancer Center, Department of Interventional Radiology (United States); Gonzalez, Ricardo J.; Conley, Anthony P.; Stewart, Steven; Han, Dale [Moffitt Cancer Center, Department of Cutaneous and Sarcoma Oncology (United States); Werner, Philip; Chaudhry, Tariq A. [Moffitt Cancer Center, Department of Anesthesia (United States); Zager, Jonathan S., E-mail: Jonathan.Zager@Moffitt.org [Moffitt Cancer Center, Department of Cutaneous and Sarcoma Oncology (United States)

2012-12-15

Purpose: Treatment of patients with unresectable liver metastases is challenging. Regional therapies to the liver have been developed that maximize treatment of the localized disease process without systemic toxic adverse effects. We discuss the procedural aspects of liver chemosaturation with percutaneous hepatic perfusion (CS-PHP). Methods: We present as an illustration of this technique a case report of the treatment of unresectable metastatic leiomyosarcoma of the liver. Results: A randomized phase III trial for unresectable liver metastases from melanoma was recently completed comparing CS-PHP with melphalan vs. best alternative care (BAC). When compared with BAC, CS-PHP was associated with a significant improvement in hepatic progression-free survival (8.0 months CS-PHP vs. 1.6 months BAC, p < 0.0001) and overall progression-free survival (6.7 months CS-PHP vs. 1.6 months BAC, p < 0.0001), respectively. On the basis of these results, and given our experience as one of the treating institutions for this phase III trial, we appealed for compassionate use of CS-PHP in a patient with isolated bilobar unresectable hepatic metastases from leiomyosarcoma. Four target lesions were identified and monitored to assess treatment response. A total of 4 CS-PHP procedures were performed, with a 25 % reduction in size of the largest lesion observed and 16 month hepatic progression-free survival. Toxicity was mild (neutropenia) and manageable on an outpatient basis. Conclusion: CS-PHP offers several advantages for unresectable hepatic sarcoma metastases. CS-PHP is minimally invasive and repeatable, and it has a predictable and manageable systemic toxicity profile. For appropriately selected patients, CS-PHP can delay tumor progression and could potentially improve survival.

Chemosaturation with Percutaneous Hepatic Perfusion for Unresectable Isolated Hepatic Metastases from Sarcoma

International Nuclear Information System (INIS)

Deneve, Jeremiah L.; Choi, Junsung; Gonzalez, Ricardo J.; Conley, Anthony P.; Stewart, Steven; Han, Dale; Werner, Philip; Chaudhry, Tariq A.; Zager, Jonathan S.

2012-01-01

Purpose: Treatment of patients with unresectable liver metastases is challenging. Regional therapies to the liver have been developed that maximize treatment of the localized disease process without systemic toxic adverse effects. We discuss the procedural aspects of liver chemosaturation with percutaneous hepatic perfusion (CS-PHP). Methods: We present as an illustration of this technique a case report of the treatment of unresectable metastatic leiomyosarcoma of the liver. Results: A randomized phase III trial for unresectable liver metastases from melanoma was recently completed comparing CS-PHP with melphalan vs. best alternative care (BAC). When compared with BAC, CS-PHP was associated with a significant improvement in hepatic progression-free survival (8.0 months CS-PHP vs. 1.6 months BAC, p < 0.0001) and overall progression-free survival (6.7 months CS-PHP vs. 1.6 months BAC, p < 0.0001), respectively. On the basis of these results, and given our experience as one of the treating institutions for this phase III trial, we appealed for compassionate use of CS-PHP in a patient with isolated bilobar unresectable hepatic metastases from leiomyosarcoma. Four target lesions were identified and monitored to assess treatment response. A total of 4 CS-PHP procedures were performed, with a 25 % reduction in size of the largest lesion observed and 16 month hepatic progression-free survival. Toxicity was mild (neutropenia) and manageable on an outpatient basis. Conclusion: CS-PHP offers several advantages for unresectable hepatic sarcoma metastases. CS-PHP is minimally invasive and repeatable, and it has a predictable and manageable systemic toxicity profile. For appropriately selected patients, CS-PHP can delay tumor progression and could potentially improve survival.

Comparison with myocardial perfusion MRI and myocardial perfusion SPECT in the diagnostic performance of coronary artery disease. A meta-analysis

International Nuclear Information System (INIS)

Iwata, Kunihiro; Kubota, Makoto; Ogasawara, Katsuhiko

2008-01-01

We compared the diagnostic abilities of stress myocardial perfusion MRI (myocardial perfusion MRI) and myocardial perfusion single photon emission computed tomography (SPECT), using a meta-analysis method. We investigated the diagnostic abilities of MRI and SPECT in similar subject groups in reports written in English or Japanese. The reports to be used for analysis were selected according to a ''screening standard,'' which was established in advance. After consolidating the data from the selected reports, we compared the integrated odds ratio, the point estimation values of sensibility/specificity, and the summary receiver operating characteristic (ROC) curve. For the analysis, six reports were selected (subjects: 153, coronary-artery target sites: 447). Meta-analysis revealed that the diagnostic ability of myocardial perfusion MRI was superior to that of myocardial perfusion SPECT regarding each of the parameters. This is considered to be supportive evidence of the usefulness of myocardial perfusion MRI. (author)

Tc-99m DTPA perfusion scintigraphy and color coded duplex sonography in the evaluation of minimal renal allograft perfusion

International Nuclear Information System (INIS)

Bair, H.J.; Platsch, G.; Wolf, F.; Guenter, E.; Becker, D.; Rupprecht, H.; Neumayer, H.H.

1997-01-01

Aim: The clinical impact of perfusion scintigraphy versus color coded Duplex sonography was evaluated, with respect to their potential in assessing minimal allograft perfusion in vitally threatened kidney transplants, i.e. oligoanuric allografts suspected to have either severe rejection or thrombosis of the renal vein or artery. Methods: From July 1990 to August 1994 the grafts of 15 out of a total of 315 patients were vitally threatened. Technetium-99m DTPA scintigraphy and color coded Duplex sonography were performed in all patients. For scintigraphic evaluation of transplant perfusion analog scans up to 60 min postinjection, and time-activity curves over the first 60 sec after injection of 370-440 MBq Tc-99m diethylenetriaminepentaacetate acid (DTPA) were used and classified by a perfusion score, the time between renal and iliac artery peaks (TDiff) and the washout of the renogram curve. Additionally, evaluation of excretion function and assessment of vascular or urinary leaks were performed. By color coded Duplex sonography the perfusion in all sections of the graft as well as the vascular anastomoses were examined and the maximal blood flow velocity (Vmax) and the resistive index (RI) in the renal artery were determined by means of the pulsed Doppler device. Pathologic-anatomical diagnosis was achieved by either biopsy or post-explant histology in all grafts. Results: Scintigraphy and color coded Duplex sonography could reliably differentiate minimal (8/15) and not perfused (7/15) renal allografts. The results were confirmed either by angiography in digital subtraction technique (DSA) or the clinical follow up. Conclusion: In summary, perfusion scintigraphy and color coded Duplex sonography are comparable modalities to assess kidney graft perfusion. In clinical practice scintigraphy and colorcoded Doppler sonography can replace digital subtraction angiography in the evaluation of minimal allograft perfusion. (orig.) [de

Encapsulated Bacillus anthracis interacts closely with liver endothelium.

Science.gov (United States)

Piris-Gimenez, Alejandro; Corre, Jean-Philippe; Jouvion, Gregory; Candela, Thomas; Khun, Huot; Goossens, Pierre L

2009-11-01

The Bacillus anthracis poly-gamma-D-glutamate capsule is essential for virulence. It impedes phagocytosis and protects bacilli from the immune system, thus promoting systemic dissemination. To further define the virulence mechanisms brought into play by the capsule, we characterized the interactions between encapsulated nontoxinogenic B. anthracis and its host in vivo through histological analysis, perfusion, and competition experiments with purified capsule. Clearance of encapsulated bacilli from the blood was rapid (>90% clearance within 5 min), with 75% of the bacteria being trapped in the liver. Competition experiments with purified capsule polyglutamate inhibited this interaction. At the septicemic phase of cutaneous infection with spores, the encapsulated bacilli were trapped in the vascular spaces of the liver and interacted closely with the liver endothelium in the sinusoids and terminal and portal veins. They often grow as microcolonies containing capsular material shed by the bacteria. We show that, in addition to its inhibitory effect on the interaction with the immune system, the capsule surrounding B. anthracis plays an active role in mediating the trapping of the bacteria within the liver and may thus contribute to anthrax pathogenesis. Because other microorganisms produce polyglutamate, it may also represent a general mechanism of virulence or in vivo survival.

Normal anatomy of lung perfusion SPECT scintigraphy

International Nuclear Information System (INIS)

Moskowitz, G.W.; Levy, L.M.

1987-01-01

Ten patients studies for possible pulmonary embolic disease had normal lung perfusion planar and SPECT scintigraphy. A computer program was developed to superimpose the CT scans on corresponding SPECT images. Superimposition of CT scans on corresponding SPECT transaxial cross-sectional images, when available, provides the needed definition and relationships of adjacent organs. SPECT transaxial sections provide clear anatomic definition of perfusion defects without foreground and background lung tissue superimposed. The location, shape, and size of the perfusion defects can be readily assessed by SPECT. An algorithm was developed for the differentiation of abnormal pulmonary perfusion patterns from normal structures on variation

Etiology of pediatric acute liver failure

Directory of Open Access Journals (Sweden)

GUO Jing

2017-10-01

Full Text Available Pediatric acute liver failure (PALF is a complex syndrome with rapid progression, and the cause of PALF is age-dependent. This article analyzes the common causes of PALF in clinical practice, including infection factors, inherited metabolic factors, poisoning and drugs, abnormal perfusion, and autoimmune diseases, among which infection factors are the most common cause. With the improvement in diagnosis and treatment techniques, the diagnostic rate of PALF caused by inherited metabolic diseases and autoimmune diseases keeps increasing. Due to the small number of PALF patients, there lacks experience in etiological diagnosis. This article summarizes related reports, in order to provide a reference for screening the causes of PALF.

A comparison of chemoembolization endpoints using angiographic versus transcatheter intraarterial perfusion/MR imaging monitoring.

Science.gov (United States)

Lewandowski, Robert J; Wang, Dingxin; Gehl, James; Atassi, Bassel; Ryu, Robert K; Sato, Kent; Nemcek, Albert A; Miller, Frank H; Mulcahy, Mary F; Kulik, Laura; Larson, Andrew C; Salem, Riad; Omary, Reed A

2007-10-01

Transcatheter arterial chemoembolization (TACE) is an established treatment for unresectable liver cancer. This study was conducted to test the hypothesis that angiographic endpoints during TACE are measurable and reproducible by comparing subjective angiographic versus objective magnetic resonance (MR) endpoints of TACE. The study included 12 consecutive patients who presented for TACE for surgically unresectable HCC or progressive hepatic metastases despite chemotherapy. All procedures were performed with a dedicated imaging system. Angiographic series before and after TACE were reviewed independently by three board-certified interventional radiologists. A subjective angiographic chemoembolization endpoint (SACE) classification scheme, modified from an established angiographic grading system in the cardiology literature, was designed to assist in reproducibly classifying angiographic endpoints. Reproducibility in SACE classification level was compared among operators, and MR imaging perfusion reduction was compared with SACE levels for each observer. Twelve patients successfully underwent 15 separate TACE sessions. SACE levels ranged from I through IV. There was moderate agreement in SACE classification (kappa = 0.46 +/- 0.12). There was no correlation between SACE level and MR perfusion reduction (r = 0.16 for one operator and 0.02 for the other two). Angiographic endpoints during TACE vary widely, have moderate reproducibility among operators, and do not correlate with functional MR imaging perfusion endpoints. Future research should aim to determine ideal angiographic and functional MR imaging endpoints for TACE according to outcome measures such as imaging response, pathologic response, and survival.

Regional cortical hyper perfusion on perfusion CT during postical motor deficit: A case report

Energy Technology Data Exchange (ETDEWEB)

Baik, Hye Jin [Dept. of Radiology, Haeundae Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of)

2013-08-15

Postictal neurologic deficit is a well-known complication mimicking the manifestation of a stroke. We present a case of a patient with clinical evidence of Todd's paralysis correlating with reversible postictal parenchymal changes on perfusion CT and magnetic resonance (MR) imaging. In this case, perfusion CT and MR imaging were helpful in the differential diagnosis of stroke-mimicking conditions.

Pulsatility index of renal artery in patients with liver cirrhosis

International Nuclear Information System (INIS)

Baik, Soon Koo; Kim, Kwan Hyun; Jeong, Yon Soo; Kim, Hyun Soo; Lee, Dong Ki; Kwon, Sang Ok

2000-01-01

As one of non-invasive methods evaluating disorders of renal perfusion using Doppler ultrasonography, PI represents the characteristics of the Doppler waveform more accurately than RI, and even when renal perfusion is severely impaired, objective estimation is possible because of using the mean velocity in its calculation. The purpose of this study is to find out the clinical usefulness of PI for evaluating disorder of renal function in patients with liver cirrhosis. The subjects were 167 patients including 89 of Child A and B groups, 39 of Child C group, and 39 of control group. We compared PI, RI, creatinine, serum renin activity and aldosterone level between each groups, and investigated the relationships of PI with creatinine clearance, serum renin activity, and aldosterone level. Meal PI was 1.00 ± 0.15 in control group, 1.17 ± 0.22 in Child A and B groups, and 1.30 ± 0.28 in Child C group, which showed significant difference between each groups (p<0.05). Also RI, creatinine clearance, serum renin activity and aldosterone level revealed significant difference between each groups (p<0.05). PI showed significant negative relationships with creatinine clearance (p=0.009), serum renin activity (p=0.06), and aldosterone level (p=0.001). Measurement of PI by Doppler ultrasonography is a useful non-invasive method for evaluation renal dysfunction in patients with liver cirrhosis.

Evaluation of Pulmonary Perfusion Scan in Heart Disease

Energy Technology Data Exchange (ETDEWEB)

Lee, J T; Kim, C K; Park, C Y; Choi, B S [Yonsei University College of Medicine, Seoul (Korea, Republic of)

1973-09-15

Pulmonary perfusion scan with radioactive {sup 113m}In-iron hydroxide particle was performed in the 25 cases of heart disease which had been diagnosed by cardiac catheterization prior to surgery from July, 1972 to July, 1973 at the Department of Radiology and Nuclear Medicine, Yonsei Medical College. It consists of 7 mitral stenosis, 2 mitral insufficiency, 1 aortic insufficiency, 3 atrial septal defect, 5 ventricular septal defect, 2 patent ductus arteriosus, 1 transposition of great vessel and 4 Tetralogy of Fallot. Findings of pulmonary perfusion scan in relation to hemodynamic data of cardiac catheterization were examined. 1) Out of 10 cases of acquired valvular heart disease, In 6 cases of stenosis and 1 case of aortic insufficiency, radioactivity was increased at both upper lung. This finding is noted when pulmonary wedge or venous pressure was elevated above 22 mmHg and arterial systolic pressure above 33 mmHg. 2) Out of 15 cases of congenital heart disease. In almost all cases of artial septal defect and ventricular septal defect except 2 cases, radioactivity was even at both entire lung. In 2 cases of patent ductras arteriosus, radioactivity was decreased especially at the left lung. It is observed that in acyanotic congenital heart disease, radioactivity of lung is not related with pulmonary arterial pressure. In 3 cases of Tetralogy of Fallot, radioactivity was even at both entire lung and in 2 of them, extrapulmonary radioactivity of liver or kidney which depends on size of defect and volume of right to left shunt reversible, was noted.

Evaluation of Pulmonary Perfusion Scan in Heart Disease

International Nuclear Information System (INIS)

Lee, J. T.; Kim, C. K.; Park, C. Y.; Choi, B. S.

1973-01-01

Pulmonary perfusion scan with radioactive 113m In-iron hydroxide particle was performed in the 25 cases of heart disease which had been diagnosed by cardiac catheterization prior to surgery from July, 1972 to July, 1973 at the Department of Radiology and Nuclear Medicine, Yonsei Medical College. It consists of 7 mitral stenosis, 2 mitral insufficiency, 1 aortic insufficiency, 3 atrial septal defect, 5 ventricular septal defect, 2 patent ductus arteriosus, 1 transposition of great vessel and 4 Tetralogy of Fallot. Findings of pulmonary perfusion scan in relation to hemodynamic data of cardiac catheterization were examined. 1) Out of 10 cases of acquired valvular heart disease, In 6 cases of stenosis and 1 case of aortic insufficiency, radioactivity was increased at both upper lung. This finding is noted when pulmonary wedge or venous pressure was elevated above 22 mmHg and arterial systolic pressure above 33 mmHg. 2) Out of 15 cases of congenital heart disease. In almost all cases of artial septal defect and ventricular septal defect except 2 cases, radioactivity was even at both entire lung. In 2 cases of patent ductras arteriosus, radioactivity was decreased especially at the left lung. It is observed that in acyanotic congenital heart disease, radioactivity of lung is not related with pulmonary arterial pressure. In 3 cases of Tetralogy of Fallot, radioactivity was even at both entire lung and in 2 of them, extrapulmonary radioactivity of liver or kidney which depends on size of defect and volume of right to left shunt reversible, was noted.

Ventilation and perfusion display in a single image

International Nuclear Information System (INIS)

Lima, J.J.P. de; Botelho, M.F.R.; Pereira, A.M.S.; Rafael, J.A.S.; Pinto, A.J.; Marques, M.A.T.; Pereira, M.C.; Baganha, M.F.; Godinho, F.

1991-01-01

A new method of ventilation and perfusion display onto a single image is presented. From the data on regions of interest of the lungs, three-dimensional histograms are created, containing as parameters X and Y for the position of the pixels, Z for the perfusion and colour for local ventilation. The perfusion value is supplied by sets of curves having Z proportional to the local perfusion count rate. Ventilation modulates colour. Four perspective views of the histogram are simultaneously displayed to allow visualization of the entire organ. Information about the normal ranges for both ventilation and perfusion is also provided in the histograms. (orig.)

Haemodynamic changes in hepatocellular carcinoma and liver parenchyma under balloon occlusion of the hepatic artery

Energy Technology Data Exchange (ETDEWEB)

Sugihara, Fumie; Murata, Satoru; Ueda, Tatsuo; Yasui, Daisuke; Yamaguchi, Hidenori; Miki, Izumi; Kumita, Shin-ichiro [Nippon Medical School, Department of Radiology, Center for Advanced Medical Technology, Tokyo (Japan); Kawamoto, Chiaki [Nippon Medical School, Department of Internal Medicine, Tokyo (Japan); Uchida, Eiji [Nippon Medical School, Department of Surgery, Tokyo (Japan)

2017-06-15

To investigate haemodynamic changes in hepatocellular carcinoma (HCC) and liver under hepatic artery occlusion. Thirty-eight HCC nodules in 25 patients were included. Computed tomography (CT) during hepatic arteriography (CTHA) with and without balloon occlusion of the hepatic artery was performed. CT attenuation and enhancement volume of HCC and liver with and without balloon occlusion were measured on CTHA. Influence of balloon position (segmental or subsegmental branch) was evaluated based on differences in HCC-to-liver attenuation ratio (H/L ratio) and enhancement volume of HCC and liver. In the segmental group (n = 20), H/L ratio and enhancement volume of HCC and liver were significantly lower with balloon occlusion than without balloon occlusion. However, in the subsegmental group (n = 18), H/L ratio was significantly higher and liver enhancement volume was significantly lower with balloon occlusion; HCC enhancement volume was similar with and without balloon occlusion. Rate of change in H/L ratio and enhancement volume of HCC and liver were lower in the segmental group than in the subsegmental group. There were significantly more perfusion defects in HCC in the segmental group. Hepatic artery occlusion causes haemodynamic changes in HCC and liver, especially with segmental occlusion. (orig.)

Effects of Steroid Hormones on Sex Differences in Cerebral Perfusion.

Directory of Open Access Journals (Sweden)

Carmen Ghisleni

Full Text Available Sex differences in the brain appear to play an important role in the prevalence and progression of various neuropsychiatric disorders, but to date little is known about the cerebral mechanisms underlying these differences. One widely reported finding is that women demonstrate higher cerebral perfusion than men, but the underlying cause of this difference in perfusion is not known. This study investigated the putative role of steroid hormones such as oestradiol, testosterone, and dehydroepiandrosterone sulphate (DHEAS as underlying factors influencing cerebral perfusion. We acquired arterial spin labelling perfusion images of 36 healthy adult subjects (16 men, 20 women. Analyses on average whole brain perfusion levels included a multiple regression analysis to test for the relative impact of each hormone on the global perfusion. Additionally, voxel-based analyses were performed to investigate the sex difference in regional perfusion as well as the correlations between local perfusion and serum oestradiol, testosterone, and DHEAS concentrations. Our results replicated the known sex difference in perfusion, with women showing significantly higher global and regional perfusion. For the global perfusion, DHEAS was the only significant predictor amongst the steroid hormones, showing a strong negative correlation with cerebral perfusion. The voxel-based analyses revealed modest sex-dependent correlations between local perfusion and testosterone, in addition to a strong modulatory effect of DHEAS in cortical, subcortical, and cerebellar regions. We conclude that DHEAS in particular may play an important role as an underlying factor driving the difference in cerebral perfusion between men and women.

Quantitative perfusion imaging in magnetic resonance imaging

International Nuclear Information System (INIS)

Zoellner, F.G.; Gaa, T.; Zimmer, F.; Ong, M.M.; Riffel, P.; Hausmann, D.; Schoenberg, S.O.; Weis, M.

2016-01-01

Magnetic resonance imaging (MRI) is recognized for its superior tissue contrast while being non-invasive and free of ionizing radiation. Due to the development of new scanner hardware and fast imaging techniques during the last decades, access to tissue and organ functions became possible. One of these functional imaging techniques is perfusion imaging with which tissue perfusion and capillary permeability can be determined from dynamic imaging data. Perfusion imaging by MRI can be performed by two approaches, arterial spin labeling (ASL) and dynamic contrast-enhanced (DCE) MRI. While the first method uses magnetically labelled water protons in arterial blood as an endogenous tracer, the latter involves the injection of a contrast agent, usually gadolinium (Gd), as a tracer for calculating hemodynamic parameters. Studies have demonstrated the potential of perfusion MRI for diagnostics and also for therapy monitoring. The utilization and application of perfusion MRI are still restricted to specialized centers, such as university hospitals. A broad application of the technique has not yet been implemented. The MRI perfusion technique is a valuable tool that might come broadly available after implementation of standards on European and international levels. Such efforts are being promoted by the respective professional bodies. (orig.) [de

Perfusion-weighted MR imaging of uterine leiomyoma

Energy Technology Data Exchange (ETDEWEB)

Takase, Hiroyasu; Munechika, Hirotsugu [Showa Univ., Tokyo (Japan). School of Medicine

2001-06-01

Serial images of uterine leiomyoma in gradient-echo, echo-planar, magnetic resonance imaging were taken to draw a {delta}R2{sup *} curve after intravenous bolus injection of Gd-DTPA. The {delta}R2{sup *} integral was calculated from a {delta}R2{sup *} curve to have relative perfusion of uterine leiomyoma. We then, evaluated the amount of perfusion correlated with MR findings, size and number of leiomyoma or the clinical symptoms and established that perfusion was correlated positively with the findings of T2 weighted images and clinical symptoms but not with other MR findings or size and number of leiomyoma. In conclusion, we presumed that the clinical symptoms could be reduced by decreasing of an amount of perfusion of uterine leiomyoma in some means. However, it remained uncertain why severe clinical symptoms were associated with a high amount of perfusion in uterine leiomyomas. (author)

Regional myocardial perfusion of cardioplegic solutions

International Nuclear Information System (INIS)

Eugene, J.; Lyons, K.P.; Ott, R.A.; Gelezunas, V.L.; Chang, C.W.; Kowall, M.G.; Haiduc, N.J.

1987-01-01

We compared the regional myocardial perfusion of blood cardioplegic solution (BCP) and crystalloid cardioplegic solution (CCP) in 14 mongrel dogs. Cardiopulmonary bypass was established at 28 degrees C, and a hydraulic occluder was placed around the proximal left anterior descending (LAD) coronary artery. In group 1 (N = 7) collateral coronary arteries were ligated; in group 2 (N = 7) collateral coronary arteries were left in situ. After the aorta was clamped, BCP and CCP were alternately perfused at 200 ml/min. The occluder was inflated to produce moderate, severe, and critical LAD stenosis, and regional perfusion was measured by xenon-133 washout with the Silicon Avalanche Radiation Detector. BCP infusion produced a consistently higher aortic pressure, but CCP flow was better than BCP flow under all conditions, particularly without coronary collaterals. Regional myocardial perfusion of CCP is superior to BCP

Posthemorrhage glycogen and lactate metabolism in the liver: an experimental study with postprandial rats

International Nuclear Information System (INIS)

Boija, P.O.; Nylander, G.; Suhaili, A.; Ware, J.

1988-01-01

Glycogen and lactate metabolism was studied in livers from three groups of postprandial rats sustaining 70 mm Hg hemorrhagic hypotension for variable periods, 60 min (60H group), 120 min (120H group), and nonbled controls. The donor livers were investigated after completed hemorrhage using an in vitro perfusion system with L-lactate as substrate, together with U- 14 C-lactate. The residual glycogen stores were determined after perfusions. The incorporation of labelled lactate to glucose was increased in the 120H group by 66.7% and 116.8% compared to the 60H group and controls (p less than 0.01), but glycogenolysis was still the main source of glucose released in the 120H group. Glycogen formation from labelled lactate was 46.6% higher in the 120H group compared to controls (p less than 0.05) and lactate oxidation was decreased by 67.5% (p less than 0.05). The data suggest that hepatocytes are capable of rapid change from glycolysis to gluconeogenesis during hemorrhagic hypovolemia. However, energy-sparing glycogen breakdown is given priority over gluconeogenesis as long as glycogen remains available

Consideration of Normal Variation of Perfusion Measurements in the Quantitative Analysis of Myocardial Perfusion SPECT: Usefulness in Assessment of Viable Myocardium

International Nuclear Information System (INIS)

Paeng, Jin Chul; Lim, Il Han; Kim, Ki Bong; Lee, Dong Soo

2008-01-01

Although automatic quantification software of myocardial perfusion SPECT provides highly objective and reproducible quantitative measurements, there is still some limitation in the direct use of quantitative measurements. In this study we derived parameters using normal variation of perfusion measurements, and tried to test the usefulness of these parameters. In order to calculate normal variation of perfusion measurements on myocardial perfusion SPECT, 55 patients (M:F=28:27) of low-likelihood for coronary artery disease were enrolled and 201 Tl rest / 99m Tc-MIBI stress SPECT studies were performed. Using 20-segment model, mean (m) and standard deviation (SD) of perfusion were calculated in each segment. As a myocardial viability assessment group, another 48 patients with known coronary artery disease, who underwent coronary artery bypass graft surgery (CABG) were enrolled. 201 Tl rest / 99m Tc-MIBI stress / 201 Tl 24-hr delayed SPECT was performed before CABG and SPECT was followed up 3 months after CABG. From the preoperative 24-hr delayed SPECT, Q delay (perfusion measurement), Δ delay (Q delay .m) and Z delay ((Q delay .m)/SD) were defined and diagnostic performances of them for myocardial viability were evaluated using area under curve (AUC) on receiver operating characteristic (ROC) curve analysis. Segmental perfusion measurements showed considerable normal variations among segments. In men, the lowest segmental perfusion measurement was 51.8±6.5 and the highest segmental perfusion was 87.0±5.9, and they are 58.7±8.1 and 87.3±6.0, respectively in women. In the viability assessment, Q delay showed AUC of 0.633, while those for Δ delay and Z delay were 0.735 and 0.716, respectively. The AUCs of Δ delay and Z delay were significantly higher than that of Q delay (p=0.001 and 0.018, respectively). The diagnostic performance of Δ delay , which showed highest AUC, was 85% of sensitivity and 53% of specificity at the optimal cutoff of -24.7. On automatic

Dynamic contrast-enhanced magnetic resonance imaging with Gd-EOB-DTPA for the evaluation of liver fibrosis in chronic hepatitis patients

International Nuclear Information System (INIS)

Chen, Bang-Bin; Hsu, Chao-Yu.; Yu, Chih-Wei; Wei, Shwu-Yuan; Shih, Tiffany Ting-Fang; Kao, Jia-Horng; Lee, Hsuan-Shu

2012-01-01

To develop a non-invasive MRI method for evaluation of liver fibrosis, with histological analysis as the reference standard. The study protocol was approved by the Institutional Review Board for Human Studies of our hospital, and written informed consent was obtained from all subjects. Seventy-nine subjects who received dynamic contrast-enhanced MRI (DCE-MRI) with Gd-EOB-DTPA were divided into three subgroups according to Metavir score: no fibrosis (n = 30), mild fibrosis (n = 34), and advanced fibrosis (n = 15). The DCE-MRI parameters were measured using two models: (1) dual-input single-compartment model for arterial blood flow (F a ), portal venous blood flow, total liver blood flow, arterial fraction (ART), distribution volume, and mean transit time; and (2) curve analysis model for Peak, Slope, and AUC. Statistical analysis was performed with Student's t-test and the nonparametric Kruskal-Wallis test. Slope and AUC were two best perfusion parameters to predict the severity of liver fibrosis (>F2 vs. ≤F2). Four significantly different variables were found between non-fibrotic versus mild-fibrotic subgroups: F a , ART, Slope, and AUC; the best predictor for mild fibrosis was F a (AUROC:0.701). DCE-MRI with Gd-EOB-DTPA is a noninvasive imaging, by which multiple perfusion parameters can be measured to evaluate the severity of liver fibrosis. (orig.)

Requirement of cholesterol for secretion of the very low density lipoprotein (VLDL) by the rat liver

International Nuclear Information System (INIS)

Khan, B.; Wilcox, H.G.; Elam, M.B.; Heimberg, M.

1987-01-01

Fatty acids stimulate hepatic secretion of VLDL triglyceride (TG) and cholesterol (C), increase C synthesis, and enhance activity of HMG-CoA reductase. Livers from normal fed male rats were perfused for 4 hr in a medium containing 20μCi [2- 14 C] acetate, 6g/dl serum albumin, 300 mg/dl glucose in Krebs-Henseleit HCO 3 buffer (pH 7.4), 0-100 μg/ml mevinolin, and oleate. TG secretion was decreased 0%, 23%, and 32% from control with 1, 10, and 100 μg/ml mevinolin, respectively; there was no significant effect on C or C ester (CE) secretion. Specific activity (dpm/μmol) of C synthesized from acetate in the liver decreased 67%, 98%, and 99% from control; incorporation into CE decreased 64%, 81%, and 84%, respectively. TG and phospholipid (PL) activities did not change. Synthesis of TG and PL from [1- 14 C] oleate by isolated hepatocytes from normal fed rats was not affected by addition of 0-100 μg/ml mevinolin. The mass of C and TG in the liver did not change. Preliminary experiments with perfused liver suggest that output of VLDL TG, C, CE, and PL was diminished; the ratio of C/TG and PL/TG in the VLDL was constant, suggesting secretion of fewer VLDL particles with the same composition. These data suggest that mevinolin acutely reduces biosynthesis of C and secretion of the VLDL, presumably because of a requirement of C for synthesis and secretion of the VLDL

[An automatic system controlled by microcontroller for carotid sinus perfusion].

Science.gov (United States)

Yi, X L; Wang, M Y; Fan, Z Z; He, R R

2001-08-01

To establish a new method for controlling automatically the carotid perfusion pressure. A cheap practical automatic perfusion unit based on AT89C2051 micro controller was designed. The unit, LDB-M perfusion pump and the carotid sinus of an animal constituted an automatic perfusion system. This system was able to provide ramp and stepwise updown perfusion pattern and has been used in the research of baroreflex. It can insure the precision and reproducibility of perfusion pressure curve, and improve the technical level in corresponding medical field.

Pulmonary artery perfusion versus no perfusion during cardiopulmonary bypass for open heart surgery in adults

DEFF Research Database (Denmark)

Buggeskov, Katrine B; Grønlykke, Lars; Risom, Emilie C

2018-01-01

BACKGROUND: Available evidence has been inconclusive on whether pulmonary artery perfusion during cardiopulmonary bypass (CPB) is associated with decreased or increased mortality, pulmonary events, and serious adverse events (SAEs) after open heart surgery. To our knowledge, no previous systematic...... handsearched retrieved study reports and scanned citations of included studies and relevant reviews to ensure that no relevant trials were missed. We searched for ongoing trials and unpublished trials in the World Health Organization International Clinical Trials Registry Platform (ICTRP) and at clinicaltrials......). We used GRADE principles to assess the quality of evidence. MAIN RESULTS: We included in this review four RCTs (210 participants) reporting relevant outcomes. Investigators randomly assigned participants to pulmonary artery perfusion with blood versus no perfusion during CPB. Only one trial included...

Extracts from the Mongolian traditional medicinal plants Dianthus versicolorFisch. and Lilium pumilum Delile stimulate bile flow in an isolated perfused rat liver model.

Science.gov (United States)

Obmann, Astrid; Tsendayush, Damba; Thalhammer, Theresia; Zehl, Martin; Vo, Thanh Phuong Nha; Purevsuren, Sodnomtseren; Natsagdorj, Damdinsuren; Narantuya, Samdan; Kletter, Christa; Glasl, Sabine

2010-10-05

Dianthus versicolor (Caryophyllaceae) and Lilium pumilum (Liliaceae) are two medicinal plants used in traditional Mongolian medicine to treat hepatic and gastrointestinal disorders. In this study aqueous (AE) and methanolic (ME) extracts of Dianthus versicolor and Lilium pumilum were investigated for their influence on the bile flow. The aqueous extracts of both plants were tested in absence and presence of 10 μM taurocholic acid at three different concentrations (100, 250, and 500 mg/L). The aqueous extract of Dianthus versicolor was further purified in order to locate the active principles. Two resulting fractions, one enriched in flavonoids and the other in sugars, were investigated for their influence on the bile flow in absence of taurocholic acid at 10, 20, and 40 mg/L. The aqueous extracts of both plants were analysed qualitatively by LC-MS(n) and quantitatively by UV-spectrophotometry. The bile flow experiments were performed in the isolated perfused rat liver. The compounds were identified by LC-DAD-MS(n) and TLC using references. The UV-spectrophotometric analysis was based on the monograph "Passiflorae herba" of the European Pharmacopoeia, and the total flavonoid contents were calculated and expressed as vitexin. AE and ME of both plants increased the bile flow dose-dependently (between 9% and 30%), and no hepatotoxic effect was seen even during longer perfusions. Stimulation of bile secretion was comparable in the presence and in the absence of taurocholic acid. The flavonoid fraction of Dianthus versicolor increased the bile flow by 18% (pDianthus versicolor AE (total flavonoid content 1.78%) revealed the presence of the isovitexin derivative saponarin. In the AE of Lilium pumilum (total flavonoid content 1.04%) the flavonoids rutoside, kaempferol-3-O-rutinoside, and isorhamnetin-3-O-rutinoside were detected. The results show that choleresis under extract application is due to a stimulation of the bile-salt-independent bile flow which might be caused

Radiosynthesis and preclinical evaluation of [{sup 18}F] 4-(2-fluoroethoxy)-2H-chromen-2-one as a novel myocardial perfusion imaging agent

Energy Technology Data Exchange (ETDEWEB)

Bhusari, Arun M.; Degani, Mariam S. [Institute of Chemical Technology, Mumbai (India). Dept. of Pharmaceutical Sciences and Technology; Lakshminarayanan, N.; Pawar, Yogita P.; Moghe, Surendra H.; Rajan, M.G.R. [Bhabha Atomic Research Centre, Mumbai (India). Radiation Medicine Center

2017-07-01

Recently we developed [{sup 18}F] 4-(2-fluoroethoxy)-2H-chromen-2-one as a novel {sup 18}F myocardial perfusion imaging radiotracer. It was synthesized in good radiochemical yield (>90%). The total time from radiosynthesis to its purification was less than 40 min, with excellent radiochemical purity (≥99%). It showed good stability over a period of 5 h at room temperature. The partition coefficient (log P) of radiotracer was found to be 2.70, suggesting the lipophilic nature of radiotracer. Ex vivo biodistribution study of radiotracer in normal Wistar rats for 30 min post-injection, demonstrated a good heart uptake (>1.3% ID/g) and favorable pharmacokinetics. Additionally, the radiotracer showed significant excretion (>11% ID) by liver, which is indicative of its rapid clearance. Further, in vivo biodistribution study of radiotracer in New Zealand White rabbit provided the clear PET/CT images of cardiomyocytes and myocardial perfusion. All these experimental findings suggest that [{sup 18}F] 4-(2-fluoroethoxy)-2H-chromen-2-one could be used as a potential hit for myocardial perfusion imaging.

Value of chest X-ray combined with perfusion scan versus ventilation/perfusion scan in acute pulmonary embolism

NARCIS (Netherlands)

de Groot, M. R.; Turkstra, F.; van Marwijk Kooy, M.; Oostdijk, A. H.; van Beek, E. J.; Büller, H. R.

2000-01-01

The main purpose of ventilation scanning, as adjunct to perfusion lung scintigraphy, in acute pulmonary embolism is to allow for the classification of segmental perfusion defects as mismatched, which is generally accepted as proof for the presence of pulmonary embolism. We examined whether this

Radionuclide hepatic perfusion index and ultrasonography: Assessment of portal hypertension in clinical practice

International Nuclear Information System (INIS)

Seidlova, V.; Hobza, J.; Pumprla, J.; Charouzek, J.

1989-01-01

The application is described of radionuclide angiography with hepatic perfusion index (HPI) determination in diagnosis of portal blood flow as an indicator of portal hypertension. 99m Tc and 113 In were used as tracers. Over forty patients suffering from chronic hepatitis or liver cirrhosis were included in the study. Ultrasound was used as a preliminary rapid diagnosis of portal hypertension. Radionuclide angiography combined with the HPI technique was confirmed to be a beneficial noninvasive method offering reproducible quantitative information on portal flow well correlating with the degree of portal hypertension, while the combination of ultrasound examination with radionuclide HPI determination appears to greatly enrich the diagnostic potential in hepatology. (L.O.). 4 figs., 11 refs

Myocardial perfusion scintigraphy - possibilities of diagnosing CAD

International Nuclear Information System (INIS)

Tsonevska, A.

1998-01-01

A reviewing the diagnostic methods used in the intricate process of evaluating CAD patients in a attempt to establish the role played by radionuclide methods in the diagnostic strategy is done. The perfusion cardiotropic radiopharmaceuticals used and the various methods of evaluating myocardial are discussed. Although 210 Tl-chloride is the most widely used myocardial perfusion agent, recently 99m Tc-MIBI is proposed as an alternative because of its advantages. Myocardial perfusion assessment is done by various techniques depending on the specific aim, each of them having its proper advantages and shortcomings. The inference is reached that regardless of the routine practical implementation of myocardial perfusion scintigraphy and comprehensive studies along this line in course, there are problems still not well enough clarified awaiting solution

Dengue hemorrhagic fever complicated with acute liver failure: a case report.

Science.gov (United States)

Dalugama, Chamara; Gawarammana, Indika Bandara

2017-12-08

Dengue is a common arboviral infection with a clinically diverse spectrum of presentations. Although hepatic dysfunction is commonly identified in patients will dengue illness, acute liver failure is rare. The etiopathogenesis of hepatic dysfunction is multifactorial and related to direct viral invasion of hepatocytes, immunological factors and hypoxia particularly in cases of shock in dengue hemorrhagic fever. Ideal management of dengue-related hepatic dysfunction and acute liver failure is still debated. We report a 53-year-old Sri Lankan Sinhalese male with serologically confirmed dengue fever presenting with evidence of plasma leakage developing acute liver failure evidenced by deranged liver functions, coagulopathy and altered sensorium. In addition to the 'standard care', the patient was managed with intravenous N-acetyl cysteine and blood transfusions even in the absence of bleeding or dropping packed cell volume (PCV), targeting a higher PCV in anticipation of better oxygenation at tissue level. He made a full recovery with no sequential infections. N-acetyl cysteine and packed cell transfusion aiming at a higher PCV to maintain adequate tissue perfusion during shock may be beneficial in acute liver failure due to dengue virus. Large randomized trials should be carried out to establish the efficacy of these treatment strategies to support these observations and change the current practice.

Impairment of myocardial perfusion in children with sickle cell disease; Alteration de la perfusion myocardique chez l'enfant drepanocytaire

Energy Technology Data Exchange (ETDEWEB)

Maunoury, C. [Hopital Necker-Enfants-Malades, Service de Medecine Nucleaire, 75 - Paris (France); Acar, P. [Centre Hospitalier Universitaire, Hopital des Enfants, Service de Cardiologie Pediatrique, 31 - Toulouse (France); Montalembert, M. de [Hopital Necker-Enfants-Malades, Service de Pediatrie Generale, 75 - Paris (France)

2003-10-01

While brain, bone and spleen strokes are well documented in children with sickle cell disease (SCD), impairment of myocardial perfusion is an unknown complication. Non invasive techniques such as exercise testing and echocardiography have a low sensitivity to detect myocardial ischemia in patients with SCD. We have prospectively assessed myocardial perfusion with Tl-201 SPECT in 23 patients with SCD (10 female, 13 male, mean age 12 {+-} 5 years). Myocardial SPECT was performed after stress and 3 hours later after reinjection on a single head gamma camera equipped with a LEAP collimator (64 x 64 matrix size format, 30 projections over 180 deg C, 30 seconds per step). Left ventricular ejection fraction (LVEF) was assessed by equilibrium radionuclide angiography at rest on the same day. Myocardial perfusion was impaired in 14/23 patients: 9 reversible defects and 5 fixed defects. The left ventricular cavity was dilated in 14/23 patients. The mean LVEF was 63 {+-} 9%. There was no relationship between myocardial perfusion and left ventricular dilation or function. The frequent impairment of myocardial perfusion in children with SCD could lead to suggest a treatment with hydroxyurea, an improvement of perfusion can be noted with hydroxyurea. (author)

State and development of new clinical contrast agents for MR diagnosis of liver diseases

International Nuclear Information System (INIS)

Rummeny, E.J.; Peters, P.E.

1992-01-01

MR contrast agents are developed for pharmaceutical manipulation of tissue signal intensities. Today it is widely recognized that MR contrast agents will play an increasingly important role in MR imaging of the liver. Contrast-enhanced MR-imaging allows to obtain simultaneously dynamic physiologic information and high anatomci detail. Up to now three major classes of MR contrast agents are available for clinical MR-imaging of the liver. These include paramagnetic perfusion agents, hepatobiliary agents, and superparamagnetic RES-specific iron oxide particles. A fourth class of contrast agents now in use for animal experiments includes ultrasmall superparamagnetic particles which can be targeted to extrareticuloendothelial structures such as asialoglycoprotein receptors of hepatocytes. In this article, we review recent advances in the development of MR contrast media and the clinical of contrast-enhanced MR imaging of the liver. (orig.) [de

Effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies

International Nuclear Information System (INIS)

Murase, Kenya; Nanjo, Takafumi; Ii, Satoshi; Miyazaki, Shohei; Hirata, Masaaki; Sugawara, Yoshifumi; Kudo, Masayuki; Sasaki, Kousuke; Mochizuki, Teruhito

2005-01-01

The purpose of this study was to investigate the effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies using multi-detector row CT (MDCT). Following the standard CT perfusion study protocol, continuous (cine) scans (1 s/rotation x 60 s) consisting of four 5 mm thick contiguous slices were performed using an MDCT scanner with a tube voltage of 80 kVp and a tube current of 200 mA. We generated the simulated images with tube currents of 50 mA, 100 mA and 150 mA by adding the corresponding noise to the raw scan data of the original image acquired above using a noise simulation tool. From the original and simulated images, we generated the functional images of cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) in seven patients with cerebrovascular disease, and compared the correlation coefficients (CCs) between the perfusion parameter values obtained from the original and simulated images. The coefficients of variation (CVs) in the white matter were also compared. The CC values deteriorated with decreasing tube current. There was a significant difference between 50 mA and 100 mA for all perfusion parameters. The CV values increased with decreasing tube current. There were significant differences between 50 mA and 100 mA and between 100 mA and 150 mA for CBF. For CBV and MTT, there was also a significant difference between 150 mA and 200 mA. This study will be useful for understanding the effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies using MDCT, and for selecting the tube current

Effect of milrinone therapy on splanchnic perfusion after heart transplantation.

Science.gov (United States)

Urbanowicz, Tomasz; Ligowski, Marcin; Camacho, Estillita; Walczak, Maciej; Straburzyńska-Migaj, Ewa; Tomczyk, Jadwiga; Jemielity, Marek

2014-09-23

Milrinone is a selective inhibitor of the cAMP-specific phosphodiesterase III isoenzyme in myocardium and vascular smooth muscle. Milrinone administration following heart transplantation is routine practice. The purpose of this study was to evaluate the influence of milrinone therapy on splanchnic perfusion following heart transplantation. There were 12 patients (10 males and 2 females) with a mean age of 42 ± 12 who underwent heart transplantation. Milrinone parenteral following surgery was started after surgery and continued for the next 67 ± 4 h. Repeated Swann-Ganz measurements and control transthoracic echocardiography were performed. Blood samples were taken to estimate level of lactic acid (LA), liver transaminases, serum amylase, and GFR ratio. The mean time of milrinone administration was 67 ± 4 h. The serum LA increase following milrinone discontinuation was 1.7 ± 0.7 mmol/dm(3) vs. 3.8 ± 0.9 mmol/dm(3), (pmilrinone discontinuation was 79 ± 30 IU/L vs. 135 ± 55 IU/L, pmilrinone withdrawn. There was a progressive increase in serum amylase levels after milrinone was withdrawn (80.6 ± 29 IU/L vs. 134 ± 45 IU/L, pMilrinone withdrawal during the postoperative period was associated with deterioration of splanchnic perfusion, as shown by a transient increase in lactic acid and serum increase of aminotransferases (ALT/ASP) concentration and amylase activity. The study results show the extracardiac effects of milrinone therapy.

A model of hydraulic interactions in liver parenchyma as forces behind the intrahepatic bile flow.

Science.gov (United States)

Kurbel, S; Kurbel, B; Dmitrovic, B; Wagner, J

2001-05-01

The small diameters of bile canaliculi and interlobular bile ducts make it hard to attribute the bile flow solely to the process of secretion. In the model liver within its capsule is considered a limited space in which volume expansions of one part are possible only through the shrinking of other parts. The liver capsule allows only very slow volume changes. The rate of blood flow through the sinusoides is governed by the Poisseuill-Hagen law. The model is based on a concept of circulatory liver units. A unit would contain a group of acini sharing the same conditions of arterial flow. We can imagine them as an acinar group behind the last pressure reducer on one arterial branch. Acini from neighboring units compose liver lobules and drain through the same central venule. One lobule can contain acini from several neighboring circulatory units. The perfusion cycle in one unit begins with a transient tide in the arterial flow, governed by local mediators. Corresponding acini expand, grabbing the space by compressing their neighbors in the same lobules. Vascular resistance is reduced in dilated and increased in compressed acini. Portal blood flows through the dilated acini, bypassing the compressed neighbors. The cycle ends when the portal tide slowly diminishes and acinar volume is back on the interphase value until the new perfusion cycle is started in another circulatory unit. Each cycle probably takes minutes to complete. Increased pressures both in dilated and in compressed acini force the bile to move from acinar canalicules. Both up and down changes in acinar volume might force the acinar biliary flow. In cases of arterial vasoconstriction, increased activity of vasoactive substances would keep most of the circulatory units in the interphase and increased liver resistance can be expected. Liver fibrosis makes all acini to be of fixed volume and result in increased resistance. Because of that, low pressure portal flow would be more compromised, as reported. In

Gray matter perfusion correlates with disease severity in ALS.

Science.gov (United States)

Rule, Randall R; Schuff, Norbert; Miller, Robert G; Weiner, Michael W

2010-03-09

The goal of this study is to determine if regional brain perfusion, as measured by arterial spin labeling (ASL) MRI, is correlated with clinical measures of amyotrophic lateral sclerosis (ALS) disease severity. The presence of such a relationship would indicate a possible role for ASL perfusion as a marker of disease severity and upper motor neuron involvement in ALS. Disease severity was assessed in 16 subjects with ALS (age 54 +/- 11) using the Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS) and the pulmonary function measure, forced vital capacity (FVC). Upper motor neuron involvement was assessed by testing rapid tapping of the fingers and feet. Magnetic resonance perfusion images were coregistered with structural T1-weighted MRI, corrected for partial volume effects using the structural images and normalized to a study-specific atlas. Correlations between perfusion and ALS disease severity were analyzed, using statistical parametric mapping, and including age as a factor. Analyses were adjusted for multiple clusters. ALS severity, as measured by the ALSFRS and FVC, was correlated with gray matter perfusion. This correlation was predominantly observed in the hemisphere contralateral to the more affected limbs. ALSFRS scores correlated with perfusion in the contralateral frontal and parietal lobe (p frontal lobe (p frontal lobe (p Upper motor neuron involvement, as measured by rapid finger tapping, correlated bilaterally with perfusion in the middle cingulate gyrus (p < 0.001). Amyotrophic lateral sclerosis (ALS) severity is correlated with brain perfusion as measured by arterial spin labeling (ASL) perfusion. This correlation appears to be independent of brain atrophy. ASL perfusion may be a useful tool for monitoring disease progression and assessing treatment effects in ALS.

CT perfusion study of neck lymph nodes

International Nuclear Information System (INIS)

Zhong Jin; Liu Jun; Hua Rui; Qiao Hui; Gong Yi

2011-01-01

Objective: To study the CT perfusion features of various lymph nodes in the neck. Methods: Dynamic perfusion CT scanning was performed in 83 neck lymph nodes proved by pathology, including tuberculosis lymph nodes, lymphoma and metastatic lymph nodes. The shapes, blood flow modes, and perfusion parameters of these lymph nodes were compared among 3 groups. Statistical analysis of L/T and CT perfusion parameters was performed by one-way ANOVA and LSD test. Results: The values of MTT of tuberculosis lymph nodes, lymphoma and metastatic lymph nodes were (28.13±5.08), (31.08±5.82), and (11.24±5.31) s, respectively. The MTT of metastatic lymph nodes was statistically lower than that of tuberculosis lymph nodes and lymphoma (P -1 · 100 g -1 , respectively. The values of BV were (24.68±2.84), (25.30±3.16), and (25.15± 8.81) ml·100 g -1 respectively. The values of TTP were (40.90±8.85), (40.67±6.45), and (40.98±6.62) s, respectively. There were no significant differences in L/T, BF, BV and TTP among tuberculosis lymph nodes, lymphoma and metastatic lymph nodes (P>0.05). Conclusion: CT perfusion, especially combination functional imaging with perfusion images may be helpful in judging the nature of neck lymph nodes. (authors)

Brain perfusion CT in acute stroke: current status

Energy Technology Data Exchange (ETDEWEB)

Koenig, Matthias E-mail: matthias.koenig@ruhr-uni-bochum.de

2003-03-01

Dynamic perfusion CT has become a widely accepted imaging modality for the diagnostic workup of acute stroke patients. Although compared with standard spiral CT the use of multislice CT has broadened the range from which perfusion data may be derived in a single scan run. The advent of multidetector row technology has not really overcome the limited 3D capability of this technique. Multidetector CT angiography (CTA) of the cerebral arteries may in part compensate for this by providing additional information about the cerebrovascular status. This article describes the basics of cerebral contrast bolus scanning with a special focus on optimization of contrast/noise in order to ensure high quality perfusion maps. Dedicated scan protocols including low tube voltage (80 kV) as well as the use of highly concentrated contrast media are amongst the requirements to achieve optimum contrast signal from the short bolus passage through the brain. Advanced pre and postprocessing algorithms may help reduce the noise level, which may become critical in unconscious stroke victims. Two theoretical concepts have been described for the calculation of tissue perfusion from contrast bolus studies, both of which can be equally employed for brain perfusion imaging. For each perfusion model there are some profound limitations regarding the validity of perfusion values derived from ischemic brain areas. This makes the use of absolute quantitative cerebral blood flow (CBF) values for the discrimination of the infarct core from periinfarct ischemia questionable. Multiparameter imaging using maps of CBF, cerebral blood volume (CBV), and a time parameter of the local bolus transit enables analyzing of the cerebral perfusion status in detail. Perfusion CT exceeds plain CT in depicting cerebral hypoperfusion at its earliest stage yielding a sensitivity of about 90% for the detection of embolic and hemodynamic lesions within cerebral hemispheres. Qualitative assessment of brain perfusion can be

Perfusion MRI in CNS disease: current concepts

International Nuclear Information System (INIS)

Essig, M.; Giesel, F.; Le-Huu, M.; Stieltjes, B.; Tengg, H. von; Weber, M.-A.

2004-01-01

Today there are several indications for cerebral perfusion MRI. The major indications routinely used in increasing numbers of imaging centers include cerebrovascular disease, tumor imaging and recently psychiatric disorders. Perfusion MRI is based on the injection of a gadolinium chelate and the rapid acquisition of images as the bolus of contrast agent passes through the blood vessels in the brain. The contrast agent causes a signal change; this signal change over time can be analysed to measure cerebral hemodynamics. The quality of brain perfusion studies is very dependent on the contrast agent used: a robust and strong signal decrease with a compact bolus is needed. MultiHance (gadobenate dimeglumine, Gd-BOPTA) is the first of a new class of paramagnetic MR contrast agents with a weak affinity for serum proteins. Due to the interaction of Gd-BOPTA with serum albumin, MultiHance presents with significantly higher T1- and T2-relaxivities enabling a sharper bolus profile. This article reviews the indications of perfusion MRI and the performance of MultiHance in MR perfusion of different diseases. Previous studies using perfusion MRI for a variety of purposes required the use of double dose of contrast agent to achieve a sufficiently large signal drop to enable the acquisition of a clear input function and the calculation of perfusion rCBV and rCBF maps of adequate quality. Recent studies with Multi-Hance suggest that only a single dose of this agent is needed to cause a signal drop of about 30% which is sufficient to allow the calculation of high quality rCBV and rCBF maps. (orig.)

A model system for perfusion quantification using FAIR

DEFF Research Database (Denmark)

Andersen, Irene Klærke; Sidaros, Karam; Gesmar, Henrik

2000-01-01

Flow-sensitive experiments (FAIR) have been performed on a tube-flow phantom in order to validate quantitative perfusion measurements on humans. A straight-forward correspondence between perfusion and bulk-flow is found. It is shown that the flow phantom model only holds when the slice profiles...... of the involved RF pulses are taken into account. A small flow-independent off-set may be present in the data. The off-set is explained by the model. Based on the correspondence between the phantom and the in vivo models, it is shown that the lowest flow values that could be measured in the phantom correspond...... to perfusion values lower than the cortical perfusion in the brain. Thus, the experimental accuracy and the computational methods for quantitative perfusion measurements in vivo can be validated by a tube-flow phantom....

A model system for perfusion quantification using FAIR

DEFF Research Database (Denmark)

Andersen, I.K.; Sidaros, Karam; Gesmar, H