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Sample records for perfused rat intestine-liver

  1. Hydrolysis of pyrethroids by human and rat tissues: Examination of intestinal, liver and serum carboxylesterases

    International Nuclear Information System (INIS)

    Crow, J. Allen; Borazjani, Abdolsamad; Potter, Philip M.; Ross, Matthew K.

    2007-01-01

    Hydrolytic metabolism of pyrethroid insecticides in humans is one of the major catabolic pathways that clear these compounds from the body. Rodent models are often used to determine the disposition and clearance rates of these esterified compounds. In this study the distribution and activities of esterases that catalyze pyrethroid metabolism have been investigated in vitro using several human and rat tissues, including small intestine, liver and serum. The major esterase in human intestine is carboxylesterase 2 (hCE2). We found that the pyrethroid trans-permethrin is effectively hydrolyzed by a sample of pooled human intestinal microsomes (5 individuals), while deltamethrin and bioresmethrin are not. This result correlates well with the substrate specificity of recombinant hCE2 enzyme. In contrast, a sample of pooled rat intestinal microsomes (5 animals) hydrolyze trans-permethrin 4.5-fold slower than the sample of human intestinal microsomes. Furthermore, it is demonstrated that pooled samples of cytosol from human or rat liver are ∼ 2-fold less hydrolytically active (normalized per mg protein) than the corresponding microsomal fraction toward pyrethroid substrates; however, the cytosolic fractions do have significant amounts (∼ 40%) of the total esteratic activity. Moreover, a 6-fold interindividual variation in carboxylesterase 1 protein expression in human hepatic cytosols was observed. Human serum was shown to lack pyrethroid hydrolytic activity, but rat serum has hydrolytic activity that is attributed to a single CE isozyme. We purified the serum CE enzyme to homogeneity to determine its contribution to pyrethroid metabolism in the rat. Both trans-permethrin and bioresmethrin were effectively cleaved by this serum CE, but deltamethrin, esfenvalerate, alpha-cypermethrin and cis-permethrin were slowly hydrolyzed. Lastly, two model lipase enzymes were examined for their ability to hydrolyze pyrethroids. However, no hydrolysis products could be detected

  2. 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

  3. Complete inhibition of creatine kinase in isolated perfused rat hearts

    International Nuclear Information System (INIS)

    Fossel, E.T.; Hoefeler, H.

    1987-01-01

    Transient exposure of an isolated isovolumic perfused rat heart to low concentrations (0.5 mM) of perfusate-born iodoacetamide resulted in complete inhibition of creatine kinase and partial inhibition of glyceraldehyde-3-phosphate dehydrogenase in the heart. At low levels of developed pressure, hearts maintained mechanical function, ATP, and creatine phosphate levels at control values. However, iodoacetamide-inhibited hearts were unable to maintain control values of end diastolic pressure or peak systolic pressure as work load increased. Global ischemia resulted in loss of all ATP without loss of creatine phosphate, indicating lack of active creatine kinase. These results indicate that isovolumic perfused rat hearts are able to maintain normal function and normal levels of high-energy phosphates without active creatine kinase at low levels of developed pressure. 31 P-NMR of the heart was carried out

  4. Reactivity of the isolated perfused rat tail vascular bed

    Directory of Open Access Journals (Sweden)

    A.S. França

    1997-07-01

    Full Text Available Isolated segments of the perfused rat tail artery display a high basal tone when compared to other isolated arteries such as the mesenteric and are suitable for the assay of vasopressor agents. However, the perfusion of this artery in the entire tail has not yet been used for functional studies. The main purpose of the present study was to identify some aspects of the vascular reactivity of the rat tail vascular bed and validate this method to measure vascular reactivity. The tail severed from the body was perfused with Krebs solution containing different Ca2+ concentrations at different flow rates. Rats were anesthetized with sodium pentobarbital (65 mg/kg and heparinized (500 U. The tail artery was dissected near the tail insertion, cannulated and perfused with Krebs solution plus 30 µM EDTA at 36oC and 2.5 ml/min and the procedures were started after equilibration of the perfusion pressure. In the first group a dose-response curve to phenylephrine (PE (0.5, 1, 2 and 5 µg, bolus injection was obtained at different flow rates (1.5, 2.5 and 3.5 ml/min. The mean perfusion pressure increased with flow as well as PE vasopressor responses. In a second group the flow was changed (1.5, 2, 2.5, 3 and 3.5 ml/min at different Ca2+ concentrations (0.62, 1.25, 2.5 and 3.75 mM in the Krebs solution. Increasing Ca2+ concentrations did not alter the flow-pressure relationship. In the third group a similar protocol was performed but the rat tail vascular bed was perfused with Krebs solution containing PE (0.1 µg/ml. There was an enhancement of the effect of PE with increasing external Ca2+ and flow. PE vasopressor responses increased after endothelial damage with air and CHAPS, suggesting an endothelial modulation of the tone of the rat tail vascular bed. These experiments validate the perfusion of the rat tail vascular bed as a method to investigate vascular reactivity

  5. desensitisation and calcium-sensitivity in the isolated perfused rat ...

    African Journals Online (AJOL)

    Dr Olaleye

    -induced desensitisation to noradrenaline were studied in the isolated perfused rat tail artery. Responses to the activators noradrenaline (NA). (3μM) and potassium chloride (KCl) (100mM) were obtained in Ca2+-buffered saline. Activators ...

  6. 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

  7. 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

  8. 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.

  9. Phosphorus nuclear magnetic resonance in isolated perfused rat pancreas

    International Nuclear Information System (INIS)

    Matsumoto, Takehisa; Kanno, Tomio; Seo, Yoshiteru; Murakami, Masataka; Watari, Hiroshi

    1988-01-01

    Phosphorus nuclear magnetic resonance spectroscopy was applied to measure phosphorus energy metabolites in isolated perfused rat pancreas. The gland was perfused with a modified Krebs-Henseleit solution at room temperature (25 degree C). 31 P resonances of creatine phosphate (PCr), ATP, ADP, inorganic phosphate (P i ) and phosphomonoesters (PMEs) were observed in all the preparations of pancreas. In different individual preparations, the resonance of PCr varied, but those of ATP were almost the same. The initial levels of PCr and ATP in individual preparations, however, remained almost unchanged during perfusion with the standard solution for 2 h. When the perfusion was stopped, the levels of ATP and PCr decreased, while the levels of PME and P i increased. At that time, the P i resonance shfted to a higher magnetic field, indicating that the tissue pH decreased. On reperfusion, the tissue levels of phosphorus compounds and the tissue pH were restored to their initial resting levels. Continuous infusion of 0.1 μM acetylcholine caused marked and sustained increases in the flow of pancreatic juice and protein output. During the stimulation the tissue levels of phosphorus compounds remained unchanged, while the tissue pH was decreased slightly

  10. Myocardial Perfusion and Function Are Distinctly Altered by Sevoflurane Anesthesia in Diet-Induced Prediabetic Rats.

    Science.gov (United States)

    van den Brom, Charissa E; Boly, Chantal A; Bulte, Carolien S E; van den Akker, Rob F P; Kwekkeboom, Rick F J; Loer, Stephan A; Boer, Christa; Bouwman, R Arthur

    2016-01-01

    Preservation of myocardial perfusion during surgery is particularly important in patients with increased risk for perioperative complications, such as diabetes. Volatile anesthetics, like sevoflurane, have cardiodepressive effects and may aggravate cardiovascular complications. We investigated the effect of sevoflurane on myocardial perfusion and function in prediabetic rats. Rats were fed a western diet (WD; n = 18) or control diet (CD; n = 18) for 8 weeks and underwent (contrast) echocardiography to determine perfusion and function during baseline and sevoflurane exposure. Myocardial perfusion was estimated based on the product of microvascular filling velocity and blood volume. WD-feeding resulted in a prediabetic phenotype characterized by obesity, hyperinsulinemia, hyperlipidemia, glucose intolerance, and hyperglycemia. At baseline, WD-feeding impaired myocardial perfusion and systolic function compared to CD-feeding. Exposure of healthy rats to sevoflurane increased the microvascular filling velocity without altering myocardial perfusion but impaired systolic function. In prediabetic rats, sevoflurane did also not affect myocardial perfusion; however, it further impaired systolic function. Diet-induced prediabetes is associated with impaired myocardial perfusion and function in rats. While sevoflurane further impaired systolic function, it did not affect myocardial perfusion in prediabetic rats. Our findings suggest that sevoflurane anesthesia leads to uncoupling of myocardial perfusion and function, irrespective of the metabolic state.

  11. Concentration of (+/-)-propranolol in isolated, perfused lungs of rat.

    Science.gov (United States)

    Dollery, C T; Junod, A F

    1976-01-01

    1 The metabolism and the accumulation of (+/-)-propranolol have been studied in isolated lungs of the rat, perfused with an artificial medium. 2 Little or no metabolism took place during the perfusion periods (up to 10 minutes). 3 Accumulation was observed with high tissue/medium ratios for substrate concentrations of 0.2 muM to 1 mM; there was evidence for saturability, but no real plateau could be seen. The presence of two binding sites with different affinities was established. 4 Cold greatly inhibited the accumulation process at low substrate concentrations, but had no effect at 1 mM propranolol. 5 Inhibition of accumulation was measured in the presence of imipramine, desmethylimipramine, nortryptiline, chlorpromazine and of Na+-free medium. Cocaine, 5-hydroxytryptamine and noradrenaline had no effect. Lidocaine enhanced the accumulation process. Release of previously bound propranolol was accelerated in the presence of propranolol and imipramine, unaffected by a Na+-free medium and decreased by cold and by lidocaine. 6 Experiments on lung tissue slices yielded qualitatively similar results to those obtained with perfused lungs. Ouabain and KCN had no or little effect on propranolol accumulation. PMID:1276542

  12. Stem cell injury and restitution after ionizing irradiation in intestine, liver, salivary gland, mesenteric lymph node

    International Nuclear Information System (INIS)

    Lee, Jae Hyun; Cho, Kyung Ja; Lee, Sun Joo; Jang, Won Suk

    1998-01-01

    There is little information about radiation injury on stem cell resident in other organs. In addition there is little experimental model in which radiation plays a role on proliferation stem cell in adult organ. This study was carried out to evaluate the early response of tissue injury and restitution in intestine, liver, salivary gland and lymph node, and to develop in vivo model to investigate stem cell biology by irradiation. The study is to assay the early response to radiation and setup an animal model for radiation effect on cellular response. Duodenal intestine, liver, submandibular salivary gland and mesenteric lymph node were selected to compare apoptosis and proliferating cell nuclear antigen (PCNA) expression to radiosensitivity. For the effect of radiation on cellular responses, rats were irradiated during starvation. Conclusionly, this study showed the value of apoptosis in detection system for evaluating cellular damage against radiation injury. Because apoptosis was regularly inducted depending on tissue-specific pattern, dose and time sequence as well as cellular activity. Furthermore in vivo model in the study will be helped in the further study to elucidate the relationship between radiation injury and starvation or malnutrition. (author). 22 refs., 6 figs

  13. Brain perfusion in acute and chronic hyperglycemia in rats

    International Nuclear Information System (INIS)

    Kikano, G.E.; LaManna, J.C.; Harik, S.I.

    1989-01-01

    Recent studies show that acute and chronic hyperglycemia cause a diffuse decrease in regional cerebral blood flow and that chronic hyperglycemia decreases the brain L-glucose space. Since these changes can be caused by a decreased density of perfused brain capillaries, we used 30 adult male Wistar rats to study the effect of acute and chronic hyperglycemia on (1) the brain intravascular space using radioiodinated albumin, (2) the anatomic density of brain capillaries using alkaline phosphatase histochemistry, and (3) the fraction of brain capillaries that are perfused using the fluorescein isothiocyanate-dextran method. Our results indicate that acute and chronic hyperglycemia do not affect the brain intravascular space nor the anatomic density of brain capillaries. Also, there were no differences in capillary recruitment among normoglycemic, acutely hyperglycemic, and chronically hyperglycemic rats. These results suggest that the shrinkage of the brain L-glucose space in chronic hyperglycemia is more likely due to changes in the blood-brain barrier permeability to L-glucose

  14. 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.

  15. Evaluation of radio stability of cimetidine in perfused rat stomach

    International Nuclear Information System (INIS)

    EL-Sayed, M.E.; Roushdy, H.M.; mohamed, S.H.; ElSayeh, H.B.M. EL-Sayeh.

    1988-01-01

    The stability of cimetidine towards gamma irradiation has been investigated. The pharmacological activity of cimetidine was screened by studying the effect of non-irradiated as well as irradiated drug on basal and histamine-stimulated gastric acid secretion in lumen-perfused rat preparation. This study revealed that gamma irradiated cimetidine was highly active inhibitor of basal and histamine-stimulated gastric acid secretion. Assessment of the chemical constitution of the drug before and after irradiation, using infrared (IR) spectrophotometry, ultraviolet (UV) spectrophotometry and nuclear magnetic resonance (NMR) spectroscopy were carried out. The physicochemical study revealed that irradiation of the drug at a dose level of 25 kGy has no remarkable effect on the chemical constitution of cimetidine. Results of the present study showed that cimetidine is chemically and pharmacologically stable when exposed to gamma-irradiation at a dose level of 25 kGy

  16. 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

  17. Use of nucleotides in weanling rats with diarrhea induced by a lactose overload: effect on the evolution of diarrhea and weight and on the histopathology of intestine, liver and spleen

    Directory of Open Access Journals (Sweden)

    Norton R.

    2001-01-01

    Full Text Available Until recently, dietary sources of nucleotides were thought not to be essential for good nutrition. Certain states with higher metabolic demands may require larger amounts that cannot be provided by endogenous production. The objective of the present study was to determine the action of nucleotides on the recovery from lactose-induced diarrhea in weaned rats. Thirty-six weanling Fisher rats were divided into two groups. Group 1 received a standard diet and group 2 received a diet containing lactose in place of starch. On the 10th day, six animals per group were sacrificed for histopathological evaluation. The remaining animals were divided into two other subgroups, each with 6 animals, receiving a control diet, a control diet with nucleotides (0.05% adenosine monophosphate, 0.05% guanosine monophosphate, 0.05% cytidine monophosphate, 0.05% uridine monophosphate and 0.05% inosine monophosphate, a diet with lactose, and a diet with lactose and nucleotides. On the 32nd day of the experiment all animals were sacrificed. Animals with diarrhea weighed less than animals without diarrhea. The introduction of nucleotides did not lead to weight gain. Mean diet consumption was lower in the group that continued to ingest lactose, with the group receiving lactose plus nucleotides showing a lower mean consumption. Animals receiving lactose had inflammatory reaction and deposits of periodic acid-Schiff-positive material in intestinal, hepatic and splenic tissues. The introduction of nucleotides led to an improvement of the intestinal inflammatory reaction. In lactose-induced diarrhea, when the stimulus is maintained - lactose overload - the nucleotides have a limited action on the weight gain and on recovery of intestinal morphology, although they have a protective effect on hepatic injury and improve the inflammatory response.

  18. Arterio-venous anastomoses in isolated, perfused rat lungs.

    Science.gov (United States)

    Conhaim, Robert L; Segal, Gilad S; Watson, Kal E

    2016-11-01

    Several studies have suggested that large-diameter (>25 μm) arterio-venous shunt pathways exist in the lungs of rats, dogs, and humans. We investigated the nature of these pathways by infusing specific-diameter fluorescent latex particles (4, 7, 15, 30, or 50 μm) into isolated, ventilated rat lungs perfused at constant pressure. All lungs received the same mass of latex (5 mg), which resulted in infused particle numbers that ranged from 1.7 × 10 7 4 μm particles to 7.5 × 10 4 50 μm particles. Particles were infused over 2 min. We used a flow cytometer to count particle appearances in venous effluent samples collected every 0.5 min for 12 min from the start of particle infusion. Cumulative percentages of infused particles that appeared in the samples averaged 3.17 ± 2.46% for 4 μm diameter particles, but ranged from 0.01% to 0.17% for larger particles. Appearances of 4 μm particles followed a rapid upslope beginning at 30 sec followed by a more gradual downslope that lasted for up to 12 min. All other particle diameters also began to appear at 30 sec, but followed highly irregular time courses. Infusion of 7 and 15 μm particles caused transient but significant perfusate flow reductions, while infusion of all other diameters caused insignificant reductions in flow. We conclude that small numbers of bypass vessels exist that can accommodate particle diameters of 7-to-50 μm. We further conclude that our 4 μm particle data are consistent with a well-developed network of serial and parallel perfusion pathways at the acinar level. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  19. Hydrogen ion changes and contractile behavior in the perfused rat heart

    NARCIS (Netherlands)

    Cingolani, H.E.; Maas, A.H.J.; Zimmerman, A.N.E.; Meijler, F.L.

    1975-01-01

    The effect of acid-base alterations was analyzed using isolated rat hearts perfused at constant coronary perfusion pressure, and stimulated to contract at constant rate. The amount of shortening in the major axis and its derivative were measured to assess myocardial contractility. Both the

  20. Effects of Constant Flow vs. Constant Pressure Perfusion on Fluid Filtration in Severe Hypothermic Isolated Blood-Perfused Rat Lungs.

    Science.gov (United States)

    Halsøy, Kathrine; Kondratiev, Timofey; Tveita, Torkjel; Bjertnaes, Lars J

    2016-01-01

    Victims of severe accidental hypothermia are prone to fluid extravasation but rarely develop lung edema. We hypothesize that combined hypothermia-induced increase in pulmonary vascular resistance (PVR) and a concomitant fall in cardiac output protect the lungs against edema development. Our aim was to explore in hypothermic-isolated blood-perfused rat lungs whether perfusion at constant pressure influences fluid filtration differently from perfusion at constant flow. Isolated blood-perfused rat lungs were hanging freely in a weight transducer for measuring weight changes (ΔW). Fluid filtration coefficient (Kfc), was determined by transiently elevating left atrial pressure (Pla) by 5.8 mmHg two times each during normothermia (37°C) and during hypothermia (15°C). The lung preparations were randomized to two groups. One group was perfused with constant flow (Constant flow group) and the other group with constant pulmonary artery pressure (Constant PPA group). Microvascular pressure (Pmv) was determined before and during elevation of Pla (ΔPmv) by means of the double occlusion technique. Kfc was calculated with the formula Kfc = ΔW/ΔPmv/min. All Kfc values were normalized to predicted lung weight (P LW ), which was based on body weight (BW) according to the formula: P LW  = 0.0053 BW - 0.48 and presented as Kfc PLW in mg/min/mmHg/g. At cessation, bronchoalveolar lavage (BAL) fluid/perfusate protein concentration (B/P) ratio was determined photometrically. Data were analyzed with parametric or non-parametric tests as appropriate. p  Kfc PLW and B/P ratio increased significantly by more than 10-fold during hypothermia concerted by visible signs of edema in the trachea. Hemoglobin and hematocrit increased within the Constant flow group and between the groups at cessation of the experiments. In hypothermic rat lungs perfused at constant flow, fluid filtration coefficient per gram P LW and B/P ratio increased more than 10-fold concerted by increased

  1. 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)

  2. Glucose uptake and transport in contracting, perfused rat muscle with different pre-contraction glycogen concentrations

    DEFF Research Database (Denmark)

    Hespel, P; Richter, Erik

    1990-01-01

    1. Glucose uptake and transport, muscle glycogen, free glucose and glucose-6-phosphate concentrations were studied in perfused resting and contracting rat skeletal muscle with different pre-contraction glycogen concentrations. Rats were pre-conditioned by a combination of swimming exercise and diet......, resulting in either low (glycogen-depleted rats), normal (control rats) or high (supercompensated rats) muscle glycogen concentrations at the time their hindlimbs were perfused. 2. Compared with control rats, pre-contraction muscle glycogen concentration was approximately 40% lower in glycogen-depleted rats......, whereas it was 40% higher in supercompensated rats. Muscle glycogen break-down correlated positively (r = 0.76; P less than 0.001) with pre-contraction muscle glycogen concentration. 3. Glucose uptake during contractions was approximately 50% higher in glycogen-depleted hindquarters than in control...

  3. Uptake of exogenous spermidine by rat lungs perfused in situ

    International Nuclear Information System (INIS)

    Rannels, D.E.; Addison, J.L.

    1987-01-01

    Uptake of the polyamine spermidine (SPD) from the pulmonary circulation was characterized by using ventilated rat lungs perfused in situ with Krebs-Henseleit-bicarbonate buffer containing 4.5% bovine serum albumin, 5.6 mM glucose, and 20 amino acids at plasma levels. [ 14 C]SPD was accumulated by the lungs in a time- and concentration-dependent manner. The pathway of SPD uptake exhibited saturation kinetics with an apparent K/sub m/ in the range of 1 μM and a V/sub max/ of 450-540 pmol/g lung min. SPD uptake was inhibited by the naturally occurring polyamines putrescine and spermine (SPM) and by the inhibitor of polyamine synthesis, methyglyoxal bis(guanylhydrazone) (MGBG). Inhibition of SPD uptake by SPM followed competitive kinetics; although MGBG was also a competitive inhibitor of SPD uptake, MGBG was less effective than SPM. These observations indicate that SPD is taken up from the pulmonary circulation by a carrier-mediated pathway that is inhibited by other natural polyamines and by MGBG and exhibits by other natural polyamines and by MGBG and exhibits substrate affinity in the range of plasma SPD concentrations

  4. Uptake of exogenous spermidine by rat lungs perfused in situ

    Energy Technology Data Exchange (ETDEWEB)

    Rannels, D.E.; Addison, J.L.

    1987-01-01

    Uptake of the polyamine spermidine (SPD) from the pulmonary circulation was characterized by using ventilated rat lungs perfused in situ with Krebs-Henseleit-bicarbonate buffer containing 4.5% bovine serum albumin, 5.6 mM glucose, and 20 amino acids at plasma levels. (/sup 14/C)SPD was accumulated by the lungs in a time- and concentration-dependent manner. The pathway of SPD uptake exhibited saturation kinetics with an apparent K/sub m/ in the range of 1 ..mu..M and a V/sub max/ of 450-540 pmol/g lung min. SPD uptake was inhibited by the naturally occurring polyamines putrescine and spermine (SPM) and by the inhibitor of polyamine synthesis, methyglyoxal bis(guanylhydrazone) (MGBG). Inhibition of SPD uptake by SPM followed competitive kinetics; although MGBG was also a competitive inhibitor of SPD uptake, MGBG was less effective than SPM. These observations indicate that SPD is taken up from the pulmonary circulation by a carrier-mediated pathway that is inhibited by other natural polyamines and by MGBG and exhibits by other natural polyamines and by MGBG and exhibits substrate affinity in the range of plasma SPD concentrations.

  5. Effect of nutritional status on oxidative stress in an ex vivo perfused rat liver.

    Science.gov (United States)

    Stadler, Michaela; Nuyens, Vincent; Seidel, Laurence; Albert, Adelin; Boogaerts, Jean G

    2005-11-01

    Normothermic ischemia-reperfusion is a determinant in liver injury occurring during surgical procedures, ischemic state, and multiple organ failure. The preexisting nutritional status of the liver might contribute to the extent of tissue injury and primary nonfunction. The aim of this study was to determine the role of starvation on hepatic ischemia-reperfusion injury in normal rat livers. Rats were randomly divided into two groups: one had free access to food, the other was fasted for 16 h. The portal vein was cannulated, and the liver was removed and perfused in a closed ex vivo system. Two modes of perfusion were applied in each series of rats, fed and fasting. In the ischemia-reperfusion mode, the experiment consisted of perfusion for 15 min, warm ischemia for 60 min, and reperfusion during 60 min. In the nonischemia mode, perfusion was maintained during the 135-min study period. Five rats were included in each experimental condition, yielding a total of 20 rats. Liver enzymes, potassium, glucose, lactate, free radicals, i.e., dienes and trienes, and cytochrome c were analyzed in perfusate samples. The proportion of glycogen in hepatocytes was determined in tissue biopsies. Transaminases, lactate dehydrogenase, potassium, and free radical concentrations were systematically higher in fasting rats in both conditions, with and without ischemia. Cytochrome c was higher after reperfusion in the fasting rats. Glucose and lactate concentrations were greater in the fed group. The glycogen content decreased in both groups during the experiment but was markedly lower in the fasting rats. In fed rats, liver injury was moderate, whereas hepatocytes integrity was notably impaired both after continuous perfusion and warm ischemia in fasting animals. Reduced glycogen store in hepatocytes may explain reduced tolerance.

  6. Kinetics of reversible-sequestration of leukocytes by the isolated perfused rat lung

    Energy Technology Data Exchange (ETDEWEB)

    Goliaei, B.

    1980-08-01

    The kinetics and morphology of sequestration and margination of rat leukocytes were studied using an isolated perfused and ventilated rat lung preparation. Whole rat blood, bone marrow suspension, or leukocyte suspensions, were used to perfuse the isolated rat lung. The lung was also perfused with latex particle suspensions and the passage of particles through the lung capillaries was studied. When a leukocyte suspension was perfused through the lung in the single-pass mode, the rate of sequestration decreased as more cells were perfused. In contrast, latex particles of a size comparable to that of leukocytes were totally stopped by the lung. When the leukocyte suspension was recirculated through the lung, cells were rapidly removed from circulation until a steady state was reached, after which no net removal of cells by the lung occurred. These results indicate that leukocytes are reversibly sequestered from circulation. The sequestered cells marginated and attached to the luminal surface of the endothelium of post-capillary venules and veins. A mathematical model was developed based on the assumption that the attachment and detachment of leukocytes to blood vessel walls follows first-order kinetics. The model correctly predicts the following characteristics of the system: (a) the kinetics of the sequestration of leukocytes by the lung; (b) the existence of a steady state when a suspension of leukocytes is recirculated through the lung; and (c) the independence of the fraction of cells remaining in circulation from the starting concentration for all values of starting concentration. (ERB)

  7. 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

  8. Effects of thyroid state on respiration of perfused rat and guinea pig hearts

    International Nuclear Information System (INIS)

    Read, L.C.; Wallace, P.G.; Berry, M.N.

    1987-01-01

    The effects of thyroid state on the respiration of the isolated heart were investigated using retrograde perfused rat and guinea pig hearts. In both species, hypothyroidism caused a marked depression in circulating thyroid hormone concentrations and in the respiration of the isolated, retrograde perfused heart. Hypothyroidism was caused by injecting animals with Na 131 I. The effects on myocardial respiration could be attributed to changes in the contraction frequency and in the oxygen consumption per beat, with little contribution from basal respiration. Treatment of animals with thyroxine elevated plasma thyroid hormones to a similar extent in rats and guinea pigs. In the latter, thyroxine treatment was associated with substantial increases in the contraction frequency and the oxygen consumption per beat of the isolated heart. In contrast, only small changes were apparent in the retrograde perfused rat heart, observations that were confirmed in rat hearts perfused at near physiological work loads. It was concluded that rat hearts isolated from normal animals function at near maximal thyroid state, in contrast to the guinea pig heart, which requires higher circulating concentrations of thyroid hormones to attain maximal responses

  9. 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

  10. Vasopressin and angiotensin II stimulate oxygen uptake in the perfused rat hindlimb

    DEFF Research Database (Denmark)

    Colquhoun, E Q; Hettiarachchi, M; Ye, J M

    1988-01-01

    Vasopressin and angiotensin II markedly stimulated oxygen uptake in the perfused rat hindlimb. The increase due to each agent approached 70% of the basal rate, and was greater than that produced by a maximal concentration of norepinephrine. Half-maximal stimulation occurred at 60 pM vasopressin, 0...

  11. 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

  12. Kidney in potassium depletion. II. K+ handling by the isolated perfused rat kidney

    International Nuclear Information System (INIS)

    Hayashi, M.; Katz, A.I.

    1987-01-01

    In a companion paper the authors reported a large increment in Na + -K + -ATPase activity and [ 3 H]ouabain binding the inner stripe of outer medullary collecting tubules from K-depleted rats. To test the hypothesis that the increased number of Na + -K + pumps in these animals may be involved in potassium reabsorption they examined the effect of ouabain on K excretion by isolated, perfused kidneys from rats fed a K-free diet for 3 wk. Kidneys from K-depleted rats retain potassium avidly, both the fractional (FE/sub K/) and absolute K excretion being approximately fivefold lower than in control kidneys. Ouabain (5 mM) increased FE/sub K/ in kidneys from each K-depleted rat; similar results were obtained when kidneys were perfused with low and high potassium concentrations. In contrast, ouabain produced a variable effect in control kidneys, that depended on the perfusate potassium concentration. In K-depleted rats amiloride did not significantly alter K excretion and did not block the ouabain-induced kaliuresis, suggesting that the latter is not due to enhanced secretion secondary to increased distal fluid delivery. These results provide evidence for ouabain-sensitive potassium reabsorption in kidneys of chronically K-depleted rats, and suggest an explanation for the increased Na + -K + -ATPase observed in such animals

  13. Sulphonylurea drugs reduce hypoxic damage in the isolated perfused rat kidney.

    Science.gov (United States)

    Engbersen, R; Moons, M M; Wouterse, A C; Dijkman, H B; Kramers, C; Smits, P; Russel, F G

    2000-08-01

    Sulphonylurea drugs have been shown to protect against hypoxic damage in isolated proximal tubules of the kidney. In the present study we investigated whether these drugs can protect against hypoxic damage in a whole kidney preparation. Tolbutamide (200 microM) and glibenclamide (10 microM) were applied to the isolated perfused rat kidney prior to changing the gassing from oxygen to nitrogen for 30 min. Hypoxic perfusions resulted in an increased fractional excretion of glucose (FE % glucose 14.3+/-1.5 for hypoxic perfusions vs 4.9+/-1.6 for normoxic perfusions, mean +/- s.e. mean, P<0.05), which could be completely restored by 200 microM tolbutamide (5.7+/-0.4 for tolbutamide vs 14.3+/-1.5 for untreated hypoxic kidneys, P<0.01). Furthermore, tolbutamide reduced the total amount of LDH excreted in the urine (220+/-100 mU for tolbutamide vs. 1220+/-160 mU for untreated hypoxic kidneys, P<0.01). Comparable results were obtained with glibenclamide (10 microM). In agreement with the effect on functional parameters, ultrastructural analysis of proximal tubules showed increased brush border preservation in tolbutamide treated kidneys compared to untreated hypoxic kidneys. We conclude that glibenclamide and tolbutamide are both able to reduce hypoxic damage to proximal tubules in the isolated perfused rat kidney when applied in the appropriate concentrations.

  14. Neurotensin releases norepinephrine differentially from perfused hypothalamus of sated and fasted rat

    International Nuclear Information System (INIS)

    Lee, T.F.; Rezvani, A.H.; Hepler, J.R.; Myers, R.D.

    1987-01-01

    The central injection of neurotensin (NT) has been reported to attenuate the intake of food in the fasted animal. To determine whether endogenous norepinephrine (NE) is involved in the satiating effect of NT, the in vivo activity of NE in circumscribed sites in the hypothalamus of the unanesthetized rat was examined. Bilateral guide tubes for push-pull perfusion were implanted stereotaxically to rest permanently above one of several intended sites of perfusion, which included the paraventricular nucleus (PVN), ventromedial nucleus (VMN), and the lateral hypothalamic (LH) area. After endogenous stores of NE at a specific hypothalamic locus were radiolabeled by microinjection of 0.02-0.5 μCi of [ 3 H]NE, an artificial cerebrospinal fluid was perfused at the site at a rate of 20 μl/min over successive intervals of 5.0 min. When 0.05 or 0.1 μg/μl NT was added to the perfusate, the peptide served either to enhance or educe the local release of NE at 50% of the sites of perfusion. In these experiments, the circumscribed effect of NT on the characteristics of catecholamine efflux depended entirely on the state of hunger or satiety of the rat. That is, when NT was perfused in the fully satiated rat, NE release was augmented within the PVn or VMN; conversely, NE release was inhibited in the LH. in the animal fasted for 18-22 h, NT exerted an opposite effect on the activity of NE within the same anatomical loci in that the efflux of NE was enhanced in the LH but attenuated or unaffected in the PVN or VMN. Taken together, these observations provide experimental support for the view-point that NT could act as a neuromodulator of the activity of hypothalamic noradrenergic neurons that are thought to play a functional role in the regulation of food intake

  15. [Effect of glucocorticoides on the release of amino acids in the perfused rat hindquarter (author's transl)].

    Science.gov (United States)

    Thienhaus, R; Tharandt, L; Zais, U; Staib, W

    1975-06-01

    The release of amino acids by skeletal muscle was studied in the isolated perfused rat hindquarter. Adrenalectomy depressed the formation of glutamine and alanine as well as the efflux of all other amino acids measured. Betamethasone--a synthetic glucocorticoid--caused a significant increase in the efflux of nearly all amino acids up to the level of normal controls. The release of amino acids was also increased in perfused hindquarters of diabetic rats. On the other hand, insulin exhibited a depressing effect on the release of amino acids by hindquarters of normal rats. The metabolic integrity of the muscle tissue was proved by measuring creatine phosphate, ATP, ADP and water content as well as by the significant insulin effect on glucose uptake and on [14C]leucine incorporation into muscle proteins.

  16. Decreased bilirubin transport in the perfused liver of endotoxemic rats

    NARCIS (Netherlands)

    Roelofsen, H.; van der Veere, C. N.; Ottenhoff, R.; Schoemaker, B.; Jansen, P. L.; Oude Elferink, R. P.

    1994-01-01

    Hyperbilirubinemia associated with sepsis is frequently observed in humans. In this study, an experimental rat model was developed to study bilirubin metabolism and transport during endotoxemia. Rats were injected intravenously with a single bolus of lipopolysaccharide (1 mg/kg); after 18 hours, the

  17. DECREASED BILIRUBIN TRANSPORT IN THE PERFUSED LIVER OF ENDOTOXEMIC RATS

    NARCIS (Netherlands)

    ROELOFSEN, H; VANDERVEERE, CN; OTTENHOFF, R; SCHOEMAKER, B; JANSEN, PLM; ELFERINK, RPJO

    1994-01-01

    Background/Aims: Hyperbilirubinemia associated with sepsis is frequently observed in humans. In this study, an experimental rat model was developed to study bilirubin metabolism and transport during endotoxemia. Methods: Rats were injected intravenously with a single bolus of lipopolysaccharide (1

  18. New method of isolation and perfusion of rat pancreas for phosphorus nucletic resonance study

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Takehisa; Kanno, Tomio; Murakami, Masataka; Watari, Hiroshi; Seo, Yoshiteru

    1988-02-01

    Phosphorus nuclear magnetic resonance (/sup 31/P-NMR) was applied to measure phosphorus metabolites in the pancreas. Rat pancreatic gland was isolated and perfused with a modified Krebs-Henseleit solution at room temperature (25 deg C). Removal of the duodenum from the pancreas made it possible to record /sup 31/P-NMR spectra only from the pancreatic tissue. /sup 31/P signals of creatine phosphate (PCr), ATP and inorganic phosphate (Pi) were observed in all the glands. In different individual glands, the Signal intensity of PCr varied, but those of ATP were almost the same. The initial levels of all the phosphorus metabolites in individual glands remained almost unchanged during perfusion with the standard solution for 2 hours. When the perfusion was stopped, signal intensity of ATP and PCr decreased while Pi resonance increased and shifted to a higher magnetic field, indicating tissue acidification. On re-perfusion, each resonance and tissue pH were restored to the respective initial resting levels. Continuous stimulation with 0.3 ..mu..M acetylcholine (ACh) or 0.1 nM CCK-8 caused a markedly larger increase in pancreatic exocrine secretion than that observed in the perfused pancreas which was prepared by the previous method. Continuous stimulation with 0.1 ..mu..M ACh caused a marked and sustained increase in pancreatic exocrine secretion. During the stimulation, the resonances of phosphorus energy metabolites and tissue pH remained almost unchanged. These results indicate that the isolated perfused rat pancreas which is prepared by our new method is a useful preparation for analysis of secretion-metabolism coupling in the exocrine pancreas.

  19. Cyclooxygenase-2-dependent bronchoconstriction in perfused rat lungs exposed to endotoxin.

    OpenAIRE

    Uhlig, S.; Nüsing, R.; von Bethmann, A.; Featherstone, R. L.; Klein, T.; Brasch, F.; Müller, K. M.; Ullrich, V.; Wendel, A.

    1996-01-01

    BACKGROUND: Lipopolysaccharides (LPS), widely used to study the mechanisms of gram-negative sepsis, increase airway resistance by constriction of terminal bronchioles. The role of the cyclooxygenase (COX) isoenzymes and their prostanoid metabolites in this process was studied. MATERIALS AND METHODS: Pulmonary resistance, the release of thromboxane (TX) and the expression of COX-2 mRNA were measured in isolated blood-free perfused rat lungs exposed to LPS. RESULTS: LPS induced the release of T...

  20. Intra-peritoneal administration of interleukin-1 beta induces impaired insulin release from the perfused rat pancreas

    DEFF Research Database (Denmark)

    Wogensen, L; Helqvist, S; Pociot, F

    1990-01-01

    Previous studies have demonstrated a stimulatory effect of interleukin-1 beta (IL-1 beta) on insulin and glucagon release from the perfused rat pancreas, accompanied by selective lysis of 20% of beta-cells as assessed by electronmicroscopy. However, we have not observed an inhibitory action of IL-1...... beta on insulin release from the perfused pancreas as shown for isolated islets. To test whether periodical exposure of the endocrine pancreas to circulating IL-1 beta in vivo affects insulin release from the intact perfused pancreas, rats were treated with daily intraperitoneal injections of 4...

  1. Effects of perfusion pressure and insulin on (3H) cytochalasin B (CB) binding to control and diabetic rat hearts

    International Nuclear Information System (INIS)

    Pleta, M.; Chan, T.

    1987-01-01

    Using ( 3 H) CB, they attempted to quantitate the changes in the amount of glucose transporters in the plasma membrane (PM) and intracellular membranes (HSP) prepared from rat hearts perfused with insulin, under low and high pressure. Membranes isolated from non-perfused hearts showed a PM/HSP ratio of (0.593). Hearts perfused with low pressure showed a lower ratio of (0.474). Perfusion with insulin increased the ratio to (1.8), almost a 3-4 fold increase from low perfusion pressure. These data correlate with insulin effects in glucose transport and CB binding in the fat cells. High pressure perfusion increased the PM/HSP ratio by 1-2 fold. ( 3 H) 2-DG transport indicates a comparable increase in glucose uptake with high pressure, but with insulin only a 1.5 fold increase was observed. Initial data obtained from streptozotocin (STZ) injected diabetic rats indicate low CB binding in the PM fraction. Only insulin, but not high perfusion pressure increased PM/HSP ratio in the STZ-diabetic hearts. Their data imply that while both caused apparent translocation of glucose transporters, influences on cardiac glucose metabolism by work load are different. Furthermore, STZ induced diabetes affected only the high perfusion pressure-induced and not the insulin-stimulated change in CB binding

  2. Assessment of drug disposition in the perfused rat brain by statistical moment analysis

    International Nuclear Information System (INIS)

    Sakane, T.; Nakatsu, M.; Yamamoto, A.; Hashida, M.; Sezaki, H.; Yamashita, S.; Nadai, T.

    1991-01-01

    Drug disposition in the brain was investigated by statistical moment analysis using an improved in situ brain perfusion technique. The right cerebral hemisphere of the rat was perfused in situ. The drug and inulin were injected into the right internal carotid artery as a rapid bolus and the venous outflow curve at the posterior facial vein was obtained. The infusion rate was adjusted to minimize the flow of perfusion fluid into the left hemisphere. The obtained disposition parameters were characteristics and considered to reflect the physicochemical properties of each drug. Antipyrine showed a small degree of initial uptake. Therefore, its apparent distribution volume (Vi) and apparent intrinsic clearance (CLint,i) were small. Diazepam showed large degrees of both influx and efflux and, thus, a large Vi. Water showed parameters intermediate between those of antipyrine and those of diazepam. Imipramine, desipramine, and propranolol showed a large CLint,i compared with those of the other drugs. The extraction ratio of propranolol significantly decreased with increasing concentrations of unlabeled propranolol in the perfusion fluid. These findings may be explained partly by the tissue binding of these drugs. In conclusion, the present method is useful for studying drug disposition in the brain

  3. Conversion of p-tyrosine to p-tyramine in the isolated perfused rat kidney: Modulation by perfusate concentrations of p-tyrosine

    International Nuclear Information System (INIS)

    Brier, M.E.; Bowsher, R.R.; Henry, D.P.; Mayer, P.R.

    1991-01-01

    The authors used the isolated perfused rat kidney to evaluate the role of renal decarboxylation of p-tyrosine as the source of urinary p-tyramine. Kidneys were perfused with concentrations of p-tyrosine ranging from 0.02 mM to 2.0 mM. p-Tyramine was measured by a sensitive and specific radioenzymatic assay. An increase in the perfusate concentration of p-tyrosine resulted in a significant increase in p-tyramine production that was blocked by the addition of NSD-1015, an inhibitor of aromatic-1-amino decarboxylase (AADC). They conclude p-tyrosine is the precursor for the renal production of p-tyramine, renal AADC catalyzes the formation of urinary p-tyramine, synthesized p-tyramine is predominantly excreted in the urine, and p-tyramine synthesis is modulated by the arterial delivery of p-tyrosine to the kidney

  4. 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.

  5. Intestinal permeability of forskolin by in situ single pass perfusion in rats.

    Science.gov (United States)

    Liu, Zhen-Jun; Jiang, Dong-bo; Tian, Lu-Lu; Yin, Jia-Jun; Huang, Jian-Ming; Weng, Wei-Yu

    2012-05-01

    The intestinal permeability of forskolin was investigated using a single pass intestinal perfusion (SPIP) technique in rats. SPIP was performed in different intestinal segments (duodenum, jejunum, ileum, and colon) with three concentrations of forskolin (11.90, 29.75, and 59.90 µg/mL). The investigations of adsorption and stability were performed to ensure that the disappearance of forskolin from the perfusate was due to intestinal absorption. The results of the SPIP study indicated that forskolin could be absorbed in all segments of the intestine. The effective permeability (P (eff)) of forskolin was in the range of drugs with high intestinal permeability. The P (eff) was highest in the duodenum as compared to other intestinal segments. The decreases of P (eff) in the duodenum and ileum at the highest forskolin concentration suggested a saturable transport process. The addition of verapamil, a P-glycoprotein inhibitor, significantly enhanced the permeability of forskolin across the rat jejunum. The absorbed fraction of dissolved forskolin after oral administration in humans was estimated to be 100 % calculated from rat P (eff). In conclusion, dissolved forskolin can be absorbed readily in the intestine. The low aqueous solubility of forskolin might be a crucial factor for its poor oral bioavailability. © Georg Thieme Verlag KG Stuttgart · New York.

  6. Comparative studies of D2 receptors and brain perfusion in hemi-parkinsonism rats

    International Nuclear Information System (INIS)

    Lin Yansong; Lin Xiangtong

    2000-01-01

    The relationship between dopamine D 2 receptors and brain perfusion in hemi-parkinsonism rats was studied. Hemi-parkinsonism rats were made by stereotaxic 6-hydroxy dopamine (6-OH-DA) lesions in substantia nigra (SN) and ventral tegmental area (VTA), apomorphine (Apo) which could induced the successful model rat rotates toward the intact side was used to select the rats, 125 I-IBZM ex-vivo autoradiography analysis and 99m Tc-HM-PAO regional cerebral biodistribution were used to evaluate D 2 receptors and cerebral blood flow. The HPLC-ECD were used to measure striatum DA and its metabolites content. The lesioned side striatum DA and its metabolites HVA DOPAC reduced significantly than that of the intact side and pseudo-operated group, striatum/cerebellum 125 I-IBZM uptake ratio was 8.04 +- 0.71 in lesioned side of hemi-parkinsonism rats, significantly increased compared with the intact side and the pseudo-operated group (p 0.05). These results indicated that in the 6-OH-DA lesioned side DA content decreased significantly and an up-regulation of striatum D 2 receptor binding sites was induced in hemi-parkinsonism rats, which showed good correlation with rotation behavior induced by Apo. Comparing with cerebral blood flow, D 2 receptor reflected by IBZM seems to be more specific and earlier to detect the cerebral functional impairment in experimental hemi-parkinsonism

  7. The uptake and metabolism of cystamine and taurine by isolated, ventilated and perfused rat and rabbit lungs

    International Nuclear Information System (INIS)

    Sharma, R.; Kodavanti, U.P.; Smith, L.L.; Mehendale, H.M.

    1991-01-01

    Cystamine has been reported to be taken up by the lung slices and metabolized to taurine via hypotaurine through enzymatic processes. The objective of these studies was to determine whether intact isolated, ventilated and perfused rat and rabbit lungs also posses similar characteristics. The lungs were isolated from male New Zealand white rabbits and S-D rats and perfused with 20 μM [ 14 C] cystamine (Sp. Act., 16.4 mCi/mmol) for 60 min and 30 min, respectively. Cystamine and its metabolites in lung as well as in perfusate were separated by TLC and quantitated using scintillation spectrometry. Similar experiments were also conducted with 20 μM taurine to investigate its fate in perfused lungs. Significant pulmonary uptake of cystamine and taurine occurred during perfusion. Cystamine was metabolized to [ 14 C] hypotaurine and [ 14 C] taurine. No further metabolism of taurine was evident in rat or rabbit lungs. Inclusion of 1 nM GSH did not significantly alter the ability of lungs to sequester cystamine, but the metabolism of hypotaurine to taurine was decreased. It was evident that cystamine was metabolized to taurine by perfused lungs in the same way as in lung slices

  8. In situ Raman study of redox state changes of mitochondrial cytochromes in a perfused rat heart

    DEFF Research Database (Denmark)

    Brazhe, Nadezda; Treiman, Marek; Faricelli, Barbara

    2013-01-01

    We developed a Raman spectroscopy-based approach for simultaneous study of redox changes in c-and b-type cytochromes and for a semiquantitative estimation of the amount of oxygenated myoglobin in a perfused rat heart. Excitation at 532 nm was used to obtain Raman scattering of the myocardial...... surface of the isolated heart at normal and hypoxic conditions. Raman spectra of the heart under normal pO2 demonstrate unique peaks attributable to reduced c-and b-type cytochromes and oxymyoglobin (oMb). The cytochrome peaks decreased in intensity upon FCCP treatment, as predicted from uncoupling...

  9. 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

  10. Uptake of perfusion imaging agents by transplanted hearts: an experimental study in rats

    International Nuclear Information System (INIS)

    Bergsland, J.; Carr, E.A. Jr.; Carroll, M.; Feldman, M.J.; Kung, H.; Wright, J.R.

    1989-01-01

    There is a need for a reliable noninvasive marker of rejection in transplanted hearts. Endomyocardial biopsy is now the universally accepted diagnostic method of choice, but the invasiveness of the procedure and the limited size of the sample obtained makes this method far from ideal. As coronary blood flow may be expected to decrease during acute rejection, there has been interest in thallium-201 chloride (T1), a perfusion marker, as an imaging agent for diagnosing cardiac rejection. Hexakis(t-butylisonitrile)-technetium (Tc-TBI) is a representative of a new class of radiopharmaceuticals proposed as perfusion markers. We have compared the uptake of these imaging agents in a rat model of cardiac transplantation. Uptake of Tc-TBI as well as of T1 was significantly lower in rejecting than in nonrejecting hearts. This change was found in both left (LV) and right (RV) ventricles. Allografts in animals treated with cyclosporine (CyA) showed less severe rejection and higher uptakes of both imaging agents as compared to unmodified rejection. Our results suggest that perfusion imaging with these radionuclides is a potentially useful approach to the problem of detecting allograft rejection

  11. Intestinal absorption of dietary fat from a liquid diet perfused in rats at a submaximum level

    International Nuclear Information System (INIS)

    Simko, V.; Kelley, R.E.

    1988-01-01

    The small intestine of rats was perfused in vivo for 2 h with a nutritionally complete liquid diet (68% calories from fat as corn oil). As the perfusion increased from 106 mg/2 h, the intestinal disappearance of the 14 C-triolein marker remained proportional to the load up to 2359 mg fat/2 h. Despite a decrease in absorption from 70 to 17%, this represents a very large fat intake. Fat absorption improved when medium-chain triglycerides or octanoic acid replaced corn oil (both p less than 0.01). Linoleic acid was absorbed from the diet less than corn oil (p less than 0.01). Dry ox bile reduced fat absorption (p less than 0.05); lipase and an antacid had no effect. Corn oil perfused alone was absorbed better than from the diet (p less than 0.01). Data with 14 C-triolein was confirmed by dry-weight disappearance of the diet and by net intestinal water balance. Usual feeding underutilizes a large reserve for fat absorption. This reserve should be considered in therapeutic nutrition

  12. 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

  13. Intercellular adhesion molecule-1 blockade attenuates inflammatory response and improves microvascular perfusion in rat pancreas grafts.

    Science.gov (United States)

    Preissler, Gerhard; Eichhorn, Martin; Waldner, Helmut; Winter, Hauke; Kleespies, Axel; Massberg, Steffen

    2012-10-01

    After pancreas transplantation (PTx), early capillary malperfusion and leukocyte recruitment indicate the manifestation of severe ischemia/reperfusion injury (IRI). Oscillatory blood-flow redistribution (intermittent capillary perfusion, IP), leading to an overall decrease in erythrocyte flux, precedes complete microvascular perfusion failure with persistent blood flow cessation. We addressed the role of intercellular adhesion molecule-1 (ICAM-1) for leukocyte-endothelial interactions (LEIs) after PTx and evaluated the contribution of IP and malperfusion. Pancreas transplantation was performed in rats after 18-hour preservation, receiving either isotype-matched IgG or monoclonal anti-ICAM-1 antibodies (10 mg/kg intravenously) once before reperfusion. Leukocyte-endothelial interaction, IP, erythrocyte flux, and functional capillary density, respectively, were examined in vivo during 2-hour reperfusion. Nontransplanted animals served as controls. Tissue samples were analyzed by histomorphometry. In grafts of IgG-treated animals, IP was encountered already at an early stage after reperfusion and steadily increased over 2 hours, whereas erythrocyte flux declined continuously. In contrast, inhibition of ICAM-1 significantly improved erythrocyte flux and delayed IP appearance by 2 hours. Further, anti-ICAM-1 significantly reduced LEI and leukocyte tissue infiltration when compared to IgG; edema development was less pronounced in response to anti-ICAM-1 monoclonal antibody. Intercellular adhesion molecule-1 blockade significantly attenuates IRI via immediate reduction of LEI and concomitant improvement of capillary perfusion patterns, emphasizing its central role during IRI in PTx.

  14. 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)

  15. Perfusion of the isolated rat brain with (/sup 14/C)-. delta. /sup 1/-tetrahydrocannabinol

    Energy Technology Data Exchange (ETDEWEB)

    Martin, B; Agurell, S [Dept. of Pharmacognosy, Faculty of Pharmacy, BMC, Uppsala (Sweden); Krieglstein, J; Rieger, H

    1977-12-01

    There is controversy over whether ..delta../sup 1/-tetrahydrocannabinol (..delta../sup 1/-THC) or its metabolites is responsible for the behavioural and cardiovascular effects of cannabis. It has been shown that, even in the absence of metabolism, ..delta../sup 1/-THC was capable of altering the EEG of isolated perfused rat brain, and must therefore contribute to the psychoactivity of cannabis. TLC studies showed no evidence for brain metabolism of (/sup 14/C)-..delta../sup 1/-THC, and in particular the 7-hydroxylated metabolite (7-OH-..delta../sup 1/-THC) could not be detected. A disproportionate amount of CNS activity in the rat cannot therefore be attributed to 7-OH-..delta../sup 1/-THC on the basis that it is formed at or near its locus of action.

  16. Perfusion of the isolated rat brain with [14C]-Δ1-tetrahydrocannabinol

    International Nuclear Information System (INIS)

    Martin, B.; Agurell, S.; Krieglstein, J.; Rieger, H.

    1977-01-01

    There is controversy over whether Δ 1 -tetrahydrocannabinol (Δ 1 -THC) or its metabolites is responsible for the behavioural and cardiovascular effects of cannabis. It has been shown that, even in the absence of metabolism, Δ 1 -THC was capable of altering the EEG of isolated perfused rat brain, and must therefore contribute to the psychoactivity of cannabis. TLC studies showed no evidence for brain metabolism of [ 14 C]-Δ 1 -THC, and in particular the 7-hydroxylated metabolite (7-OH-Δ 1 -THC) could not be detected. A disproportionate amount of CNS activity in the rat cannot therefore be attributed to 7-OH-Δ 1 -THC on the basis that it is formed at or near its locus of action. (U.K.)

  17. 31P nuclear magnetic resonance surface coil study of ischemic preconditioned isolated perfused rat heart

    International Nuclear Information System (INIS)

    Yan Yongbin; Luo Xuechun; Zhang Riqing; Wang Xiaoyin; Zuo Lin; Liu Wei

    2000-01-01

    ischemic preconditioning (IPC) will protect the heart from the damage caused by a subsequent long ischemia period. 31 P spectra of isolated perfused rat heart measured by the nuclear magnetic resonance (NMR) surface coil technique can be used to continually, dynamically and noninvasively obtain metabolism information. This paper explores the IPC mechanisms by NMR. This study shows that IPC has no effect on enhancing the ATP and PCr levels during reperfusion but makes significantly slows and smooths the changes of intracellular pH and ATP during ischemia periods. The ATP and PCr recovery rate of the IPC group after ischemia is significantly higher than that of the control group. In conclusion, the above results support that IPC can protect the rat heart by reducing damage during the ischemia period

  18. Active Oxygen Metabolites and Thromboxane in Phorbol Myristate Acetate Toxicity to the Isolated, Perfused Rat Lung.

    Science.gov (United States)

    Carpenter, Laurie Jean

    When administered intravenously or intratracheally to rats, rabbits and sheep, phorbol myristate acetate (PMA) produces changes in lung morphology and function are similar to those seen in humans with the adult respiratory distress syndrome (ARDS). Therefore, it is thought that information about the mechanism of ARDS development can be gained from experiments using PMA-treated animals. Currently, the mechanisms by which PMA causes pneumotoxicity are unknown. Results from other studies in rabbits and in isolated, perfused rabbit lungs suggest that PMA-induced lung injury is mediated by active oxygen species from neutrophils (PMN), whereas studies in sheep and rats suggest that PMN are not required for the toxic response. The role of PMN, active oxygen metabolites and thromboxane (TxA_2) in PMA-induced injury to isolated, perfused rat lungs (IPLs) was examined in this thesis. To determine whether PMN were required for PMA to produce toxicity to the IPL, lungs were perfused for 30 min with buffer containing various concentrations of PMA (in the presence or absence of PMN). When concentrations >=q57 ng/ml were added to medium devoid of added PMN, perfusion pressure and lung weight increased. When a concentration of PMA (14-28 ng/ml) that did not by itself cause lungs to accumulate fluid was added to the perfusion medium containing PMN (1 x 10 ^8), perfusion pressure increased, and lungs accumulated fluid. These results indicate that high concentrations of PMA produce lung injury which is independent of PMN, whereas injury induced by lower concentrations is PMN-dependent. To examine whether active oxygen species were involved in mediating lung injury induced by PMA and PMN, lungs were coperfused with the oxygen radical scavengers SOD and/or catalase. Coperfusion with either or both of these enzymes totally protected lungs against injury caused by PMN and PMA. These results suggest that active oxygen species (the hydroxyl radical in particular), mediate lung injury in

  19. 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.

  20. 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

  1. Changes in perfusion and fatty acid metabolism of rat heart with autoimmune myocarditis

    Energy Technology Data Exchange (ETDEWEB)

    Tsujimura, Eiichiro; Kusuoka, Hideo; Fukuchi, Kazuki; Hasegawa, Shinji; Yutani, Kenji; Nishimura, Tsunehiko [Osaka Univ., Suita (Japan). Biomedical Research Center; Hori, Masatsugu; Hirono, Satoru; Izumi, Tohru

    2000-10-01

    To elucidate the change in perfusion and aerobic metabolism in myocarditis, tissue counting and dual tracer ex vivo autoradiography with Tl-201 and free fatty acid analog, I-123- or I-125-labeled (p-iodophenyl)-methyl-pentadecanoic acid (BMIPP), were performed in rats with myocarditis induced by immunization with cardiac myosin. Inflammatory damage was classified histologically. At the acute stage (2-4 weeks after the antigen-injection), total heart uptakes of Tl and BMIPP and the ratio (BMIPP/Tl) were significantly reduced in myocarditis rats (N=15) compared with the controls (N=12). Myocardial distribution of Tl and BMIPP was not homogeneous. Relative uptake of Tl and BMIPP (N=9, 128 regions) was gradually decreased with the extent of inflammation, and the regional BMIPP/Tl was smaller than the control. At the subacute stage (7 weeks after the antigen-injection), total Tl uptake in myocarditis rats (N=5) recovered to the control level (N=4), but that of BMIPP was still significantly lower than the control. BMIPP/Tl was still significantly lower in myocarditis. Myocardial distribution of Tl and BMIPP recovered to be more homogeneous. Relative uptake of Tl and BMIPP (N=6, 78 regions) still gradually but significantly decreased with the extent of inflammation. Regional BMIPP/Tl was still depressed in myocarditis. These results indicate that myocardial perfusion and aerobic metabolism were discrepant and heterogeneously suppressed with severe inflammation during the acute stages, but the difference decreases with time. Examination with Tl-201 and BMIPP may provide information about the severity of myocarditis. (author)

  2. 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

  3. The impact of short chain fatty acids on GLP-1 and PYY secretion from the isolated perfused rat colon

    DEFF Research Database (Denmark)

    Christiansen, Charlotte Bayer; Gabe, Maria Buur Nordskov; Svendsen, Berit

    2018-01-01

    chain fatty acids (SCFAs) produced by local bacterial fermentation are suggested to activate the colonic free fatty acid receptors FFAR2 (GPR43) and FFAR3 (GPR41), stimulating the colonic L-cells. We used the isolated perfused rat colon as a model of colonic endocrine secretion and studied the effects...

  4. The influence of Poly-Vinyl-Chloride tubing on the isolated perfused rat´s heart.

    NARCIS (Netherlands)

    Meijler, F.L.; Durrer, D.

    1950-01-01

    There are types of poly-vinyl-chloride tubing sold and used for medical and biological purposes which deteriorate heart action in a few minutes. A simple method for testing P.V.C. tubing can be found in the isolated rat's he art perfused according to Langendorff.

  5. Anionic and cationic drug secretion in the isolated perfused rat kidney after neonatal surgical induction of ureteric obstruction.

    NARCIS (Netherlands)

    Gier, R.P.E. de; Feitz, W.F.J.; Masereeuw, R.; Wouterse, A.C.; Smits, D.; Russel, F.G.M.

    2003-01-01

    OBJECTIVE: To study the pathophysiological changes of renal tubular drug transport mechanisms in congenital renal obstruction, by developing a model for perfusing the isolated kidney (IPK) after neonatal surgical induction of partial ureteric obstruction in Hanover Wistar rats. MATERIAL AND METHODS:

  6. Combined, but not individual, blockade of ASIC3, P2X, and EP4 receptors attenuates the exercise pressor reflex in rats with freely perfused hindlimb muscles

    OpenAIRE

    Stone, Audrey J.; Copp, Steven W.; Kim, Joyce S.; Kaufman, Marc P.

    2015-01-01

    In healthy humans, tests of the hypothesis that lactic acid, PGE2, or ATP plays a role in evoking the exercise pressor reflex proved controversial. The findings in humans resembled ours in decerebrate rats that individual blockade of the receptors to lactic acid, PGE2, and ATP had only small effects on the exercise pressor reflex provided that the muscles were freely perfused. This similarity between humans and rats prompted us to test the hypothesis that in rats with freely perfused muscles ...

  7. Serial assessment of myocardial thallium perfusion and fatty acid utilization in spontaneously hypertensive rats

    International Nuclear Information System (INIS)

    Sago, Masayoshi; Nishimura, Tsunehiko

    1989-01-01

    To evaluate the advantage of free fatty acid imaging on the detection of hypertrophied myocardium, we compared sequentially myocardial thallium and BMIPP (15-(p-iodophenyl)-3-(R,S)-methyl pentadecanoic acid) distribution in spontaneously hypertensive rat (SHR) using dual tracer autoradiography and in vivo pin-hole imaging. Autoradiography and pin-hole imaging showed uniform myocardial distribution of BMIPP and thallium within less than 27 weeks age SHR. In 40 weeks age SHR, thallium myocardial distribution showed uniform, however, BMIPP had focal decrease. Quantitative analysis of pin-hole images showed that myocardial BMIPP and thallium uptake ratio decreased according to the ages of SHR. Our data suggest that hypertension is associated with uniform myocardial perfusion and focal alternation in the substrate used for the performance of myocardial work. Based on the above autoradiographic and in vivo pin-hole imagings, I-123 BMIPP imaging may have a potential for early detection on hypertrophic myocardium compared to thallium perfusion in clinically hypertensive patients. (author)

  8. Differential uptake of FDG and DG during post-ischaemic reperfusion in the isolated, perfused rat heart

    Energy Technology Data Exchange (ETDEWEB)

    Garlick, P.B.; Medina, R.A.; Southworth, R.; Marsden, P.K. [Department of Radiological Sciences, Guy' s, King' s and St. Thomas' School of Medicine, London (United Kingdom)

    1999-10-01

    Fluorine-18 2-fluoro-2-deoxyglucose (FDG) and 2-deoxyglucose (DG) are widely used as tracers of glucose uptake in the myocardium. Although there is agreement that the two analogues behave similarly to glucose under control conditions, there is growing evidence that some interventions (e.g. insulin stimulation or ischaemia/reperfusion) cause differential changes in their behaviour. The addition of a two-surface coil nuclear magnetic resonance (NMR) probe and a dual-perfusion cannula to our recently developed PET and NMR dual-acquisition (PANDA) system allows us to collect PET (FDG) images and phosphorus-31 NMR (2-deoxyglucose-6-phosphate) spectra simultaneously from each independently perfused coronary bed of the heart. We have used this technique to study the effect of regional ischaemia/reperfusion on FDG and DG uptake in the isolated, perfused rat heart. During control perfusion, FDG uptake was almost identical in both coronary beds. When one coronary bed was made ischaemic, FDG uptake ceased on that side but continued on the control side. Reperfusion failed to restore FDG uptake. In contrast, NMR spectra showed that, during reperfusion, the uptake and phosphorylation of DG did not differ between the two coronary beds. The results thus demonstrate that regional myocardial ischaemia/reperfusion has different effects on the uptake of FDG and DG in the isolated, perfused rat heart. (orig.)

  9. Differential uptake of FDG and DG during post-ischaemic reperfusion in the isolated, perfused rat heart

    International Nuclear Information System (INIS)

    Garlick, P.B.; Medina, R.A.; Southworth, R.; Marsden, P.K.

    1999-01-01

    Fluorine-18 2-fluoro-2-deoxyglucose (FDG) and 2-deoxyglucose (DG) are widely used as tracers of glucose uptake in the myocardium. Although there is agreement that the two analogues behave similarly to glucose under control conditions, there is growing evidence that some interventions (e.g. insulin stimulation or ischaemia/reperfusion) cause differential changes in their behaviour. The addition of a two-surface coil nuclear magnetic resonance (NMR) probe and a dual-perfusion cannula to our recently developed PET and NMR dual-acquisition (PANDA) system allows us to collect PET (FDG) images and phosphorus-31 NMR (2-deoxyglucose-6-phosphate) spectra simultaneously from each independently perfused coronary bed of the heart. We have used this technique to study the effect of regional ischaemia/reperfusion on FDG and DG uptake in the isolated, perfused rat heart. During control perfusion, FDG uptake was almost identical in both coronary beds. When one coronary bed was made ischaemic, FDG uptake ceased on that side but continued on the control side. Reperfusion failed to restore FDG uptake. In contrast, NMR spectra showed that, during reperfusion, the uptake and phosphorylation of DG did not differ between the two coronary beds. The results thus demonstrate that regional myocardial ischaemia/reperfusion has different effects on the uptake of FDG and DG in the isolated, perfused rat heart. (orig.)

  10. Quantitative arterial spin labelling perfusion measurements in rat models of renal transplantation and acute kidney injury at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Zimmer, Fabian; Schad, Lothar R.; Zoellner, Frank G. [Heidelberg Univ., Mannheim (Germany). Computer Assisted Clinical Medicine; Klotz, Sarah; Hoeger, Simone; Yard, Benito A.; Kraemer, Bernhard K. [Heidelberg Univ., Mannheim (Germany). Dept. of Medicine V

    2017-05-01

    To employ ASL for the measurement of renal cortical perfusion in particular renal disorders typically associated with graft loss and to investigate its potential to detect and differentiate the related functional deterioration i.e., in a setting of acute kidney injury (AKI) as well as in renal grafts showing acute and chronic transplant rejection. 14 Lewis rats with unilateral ischaemic AKI and 43 Lewis rats with renal grafts showing acute or chronic rejections were used. All ASL measurements in this study were performed on a 3 T MR scanner using a FAIR True-FISP approach to assess renal blood flow (RBF). Perfusion maps were calculated and the cortical blood flow was determined using a region-of-interest based analysis. RBF of healthy and AKI kidneys as well as of both rejection models, were compared. In a subsample of 20 rats, creatinine clearance was measured and correlated with cortical perfusion. RBF differs significantly between healthy and AKI kidneys (P < 0.001) with a mean difference of 213 ± 80 ml/100 g/min. Renal grafts with chronic rejections show a significantly higher (P < 0.001) mean cortical perfusion (346 ± 112 ml/100 g/min) than grafts with acute rejection (240 ± 66 ml/100 g/min). Both transplantation models have a significantly (P < 0.001) lower perfusion than healthy kidneys. Renal creatinine clearance is significantly correlated (R = 0.85, P < 0.001) with cortical blood flow. Perfusion measurements with ASL have the potential to become a valuable diagnostic tool, regarding the detection of renal impairment and the differentiation of disorders that lead to a loss of renal function and that are typically associated with graft loss.

  11. Quantitative arterial spin labelling perfusion measurements in rat models of renal transplantation and acute kidney injury at 3 T

    International Nuclear Information System (INIS)

    Zimmer, Fabian; Schad, Lothar R.; Zoellner, Frank G.; Klotz, Sarah; Hoeger, Simone; Yard, Benito A.; Kraemer, Bernhard K.

    2017-01-01

    To employ ASL for the measurement of renal cortical perfusion in particular renal disorders typically associated with graft loss and to investigate its potential to detect and differentiate the related functional deterioration i.e., in a setting of acute kidney injury (AKI) as well as in renal grafts showing acute and chronic transplant rejection. 14 Lewis rats with unilateral ischaemic AKI and 43 Lewis rats with renal grafts showing acute or chronic rejections were used. All ASL measurements in this study were performed on a 3 T MR scanner using a FAIR True-FISP approach to assess renal blood flow (RBF). Perfusion maps were calculated and the cortical blood flow was determined using a region-of-interest based analysis. RBF of healthy and AKI kidneys as well as of both rejection models, were compared. In a subsample of 20 rats, creatinine clearance was measured and correlated with cortical perfusion. RBF differs significantly between healthy and AKI kidneys (P < 0.001) with a mean difference of 213 ± 80 ml/100 g/min. Renal grafts with chronic rejections show a significantly higher (P < 0.001) mean cortical perfusion (346 ± 112 ml/100 g/min) than grafts with acute rejection (240 ± 66 ml/100 g/min). Both transplantation models have a significantly (P < 0.001) lower perfusion than healthy kidneys. Renal creatinine clearance is significantly correlated (R = 0.85, P < 0.001) with cortical blood flow. Perfusion measurements with ASL have the potential to become a valuable diagnostic tool, regarding the detection of renal impairment and the differentiation of disorders that lead to a loss of renal function and that are typically associated with graft loss.

  12. Lung perfusion in hemorrhagic shock of rats. The effects of resuscitation with whole blood, saline or hes 6%

    Energy Technology Data Exchange (ETDEWEB)

    Turhanoglu, S.; Kaya, S.; Kararmaz, A.; Turhanoglu, A.D. [Dicle Univ., Diyarbakir (Turkey). Medical School

    2001-12-01

    This study was undertaken to determine the effects of various resuscitation regimens on lung perfusion following resuscitation from hemorrhagic shock. Fourty male Sprague-Dawley rats (250-300 g) were used. The rats were divided randomly into four groups (n=10 for each) and were sedated with intramuscular ketamine (100 mg/kg). We measured blood pressure, rectal temperature and lung perfusion using radioscintigraphy with a technetium colloid indicator. The systolic blood pressure was decreased 75% by removing blood via v. jugularis in the first three groups and group 4 was accepted as the control group, and blood volume was not diminished. Then the first three groups were resuscitated with autologous blood containing 125 units heparine/ml in group 1, saline in group 2, and hydroxyethyl starch (HES) 6% in group 3. After the correction of hypovolemia, all animals were injected 100 Bg (0.1 cc) technetium 99m macroaggregated albumin ({sup 99m}Tc MAA) via penil vein. After injection of {sup 99m}Tc MAA, 3 minutes fixed images were detected by a {gamma} camera in posterior position at 15 minutes and 5 hours. {sup 99m}Tc MMA ''wash out'' rate in lung was determined quantitatively at 5 hours. Compared to a control group, lung perfusion was decreased significantly in groups resuscitated with saline, and HES 6% while perfusion was restored with autologous blood. We conclude that heparinized autologous blood saved lung capillary circulation in hemorrhagic shock in rats. (author)

  13. Lung perfusion in hemorrhagic shock of rats. The effects of resuscitation with whole blood, saline or hes 6%

    International Nuclear Information System (INIS)

    Turhanoglu, S.; Kaya, S.; Kararmaz, A.; Turhanoglu, A.D.

    2001-01-01

    This study was undertaken to determine the effects of various resuscitation regimens on lung perfusion following resuscitation from hemorrhagic shock. Fourty male Sprague-Dawley rats (250-300 g) were used. The rats were divided randomly into four groups (n=10 for each) and were sedated with intramuscular ketamine (100 mg/kg). We measured blood pressure, rectal temperature and lung perfusion using radioscintigraphy with a technetium colloid indicator. The systolic blood pressure was decreased 75% by removing blood via v. jugularis in the first three groups and group 4 was accepted as the control group, and blood volume was not diminished. Then the first three groups were resuscitated with autologous blood containing 125 units heparine/ml in group 1, saline in group 2, and hydroxyethyl starch (HES) 6% in group 3. After the correction of hypovolemia, all animals were injected 100 Bg (0.1 cc) technetium 99m macroaggregated albumin ( 99m Tc MAA) via penil vein. After injection of 99m Tc MAA, 3 minutes fixed images were detected by a γ camera in posterior position at 15 minutes and 5 hours. 99m Tc MMA ''wash out'' rate in lung was determined quantitatively at 5 hours. Compared to a control group, lung perfusion was decreased significantly in groups resuscitated with saline, and HES 6% while perfusion was restored with autologous blood. We conclude that heparinized autologous blood saved lung capillary circulation in hemorrhagic shock in rats. (author)

  14. Functional response of tumor vasculature in rats' glioma to hypercarbia evaluated by MR perfusion weighted imaging

    International Nuclear Information System (INIS)

    Zhang Qingbo; Feng Xiaoyuan; Liang Zonghui; Chen Shuan

    2008-01-01

    Objective: To evaluate the feasibility of MR PWI in judging maturity and variability of tumor vasculature in gliomas in rats. Methods: Twenty male SD rats were randomly assigned to tumor group and control group. Four weeks after implantation of C6 glioma cells in the brains of tumor group and injection of saline in the brains of control group, all rats were examined using MR PWI before and after inhalation of a mixture of 10% CO2 and 90% air. PaCO 2 and blood pH values of rats were monitored. Relative cerebral blood volume (rCBV) and relative cerebral blood flow(rCBF) values of tumors and normal brain tissue were measured. Brain sample were examined histologically using HE and immunohistochemical staining for smooth muscle actin(SMA). The histological features of gliomas were observed and SMA positively stained vessels of each tumor were counted manually using a light microscope. Perfusion data and pathological findings were analyzed statistically with SPSS for Windows. Results: PaCO 2 increased significantly [from(4.69±0.62)kPa to (7.62±0.81) kPa in tumor group and from (4.67±0.51) kPa to (7.63±0.78) kPa in control group, P 0.05), while changing rate of rCBV, rCBF in normal brain tissue correlated well with number of positive SMA labeled vessels (r=0.721 and 0.525, P 2 increase in the normal brain and in the tumor. It may be a useful technique to measure maturity of tumor vessels. (authors)

  15. Cyclooxygenase-2-dependent bronchoconstriction in perfused rat lungs exposed to endotoxin.

    Science.gov (United States)

    Uhlig, S; Nüsing, R; von Bethmann, A; Featherstone, R L; Klein, T; Brasch, F; Müller, K M; Ullrich, V; Wendel, A

    1996-05-01

    Lipopolysaccharides (LPS), widely used to study the mechanisms of gram-negative sepsis, increase airway resistance by constriction of terminal bronchioles. The role of the cyclooxygenase (COX) isoenzymes and their prostanoid metabolites in this process was studied. Pulmonary resistance, the release of thromboxane (TX) and the expression of COX-2 mRNA were measured in isolated blood-free perfused rat lungs exposed to LPS. LPS induced the release of TX and caused increased airway resistance after about 30 min. Both TX formation and LPS-induced bronchoconstriction were prevented by treatment with the unspecific COX inhibitor acetyl salicylic acid, the specific COX-2 inhibitor CGP-28238, dexamethasone, actinomycin D, or cycloheximide. LPS-induced bronchoconstriction was also inhibited by the TX receptor antagonist BM-13177. The TX-mimetic compound, U-46619, increased airway resistance predominantly by constricting terminal bronchioles. COX-2-specific mRNA in lung tissue was elevated after LPS exposure, and this increase was attenuated by addition of dexamethasone or of actinomycin D. In contrast to LPS, platelet-activating factor (PAF) induced immediate TX release and bronchoconstriction that was prevented by acetyl salicylic acid, but not by CGP-28238. LPS elicits the following biochemical and functional changes in rat lungs: (i) induction of COX-2; (ii) formation of prostaglandins and TX; (iii) activation of the TX receptor on airway smooth muscle cells; (iv) constriction of terminal bronchioles; and (v) increased airway resistance. In contrast to LPS, the PAF-induced TX release is likely to depend on COX-1.

  16. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Volume of myocardium perfused by coronary artery branches as estimated from 3D micro-CT images of rat hearts

    Science.gov (United States)

    Lund, Patricia E.; Naessens, Lauren C.; Seaman, Catherine A.; Reyes, Denise A.; Ritman, Erik L.

    2000-04-01

    Average myocardial perfusion is remarkably consistent throughout the heart wall under resting conditions and the velocity of blood flow is fairly reproducible from artery to artery. Based on these observations, and the fact that flow through an artery is the product of arterial cross-sectional area and blood flow velocity, we would expect the volume of myocardium perfused to be proportional to the cross-sectional area of the coronary artery perfusing that volume of myocardium. This relationship has been confirmed by others in pigs, dogs and humans. To test the body size-dependence of this relationship we used the hearts from rats, 3 through 25 weeks of age. The coronary arteries were infused with radiopaque microfil polymer and the hearts scanned in a micro- CT scanner. Using these 3D images we measured the volume of myocardium and the arterial cross-sectional area of the artery that perfused that volume of myocardium. The average constant of proportionality was found to be 0.15 +/- 0.08 cm3/mm2. Our data showed no statistically different estimates of the constant of proportionality in the rat hearts of different ages nor between the left and right coronary arteries. This constant is smaller than that observed in large animals and humans, but this difference is consistent with the body mass-dependence on metabolic rate.

  19. Molecular hydrogen ameliorates several characteristics of preeclampsia in the Reduced Uterine Perfusion Pressure (RUPP) rat model.

    Science.gov (United States)

    Ushida, Takafumi; Kotani, Tomomi; Tsuda, Hiroyuki; Imai, Kenji; Nakano, Tomoko; Hirako, Shima; Ito, Yumiko; Li, Hua; Mano, Yukio; Wang, Jingwen; Miki, Rika; Yamamoto, Eiko; Iwase, Akira; Bando, Yasuko K; Hirayama, Masaaki; Ohno, Kinji; Toyokuni, Shinya; Kikkawa, Fumitaka

    2016-12-01

    Oxidative stress plays an important role in the pathogenesis of preeclampsia. Recently, molecular hydrogen (H 2 ) has been shown to have therapeutic potential in various oxidative stress-related diseases. The aim of this study is to investigate the effect of H 2 on preeclampsia. We used the reduced utero-placental perfusion pressure (RUPP) rat model, which has been widely used as a model of preeclampsia. H 2 water (HW) was administered orally ad libitum in RUPP rats from gestational day (GD) 12-19, starting 2 days before RUPP procedure. On GD19, mean arterial pressure (MAP) was measured, and samples were collected. Maternal administration of HW significantly decreased MAP, and increased fetal and placental weight in RUPP rats. The increased levels of soluble fms-like tyrosine kinase-1 (sFlt-1) and diacron reactive oxygen metabolites as a biomarker of reactive oxygen species in maternal blood were decreased by HW administration. However, vascular endothelial growth factor level in maternal blood was increased by HW administration. Proteinuria, and histological findings in kidney were improved by HW administration. In addition, the effects of H 2 on placental villi were examined by using a trophoblast cell line (BeWo) and villous explants from the placental tissue of women with or without preeclampsia. H 2 significantly attenuated hydrogen peroxide-induced sFlt-1 expression, but could not reduce the expression induced by hypoxia in BeWo cells. H 2 significantly attenuated sFlt-1 expression in villous explants from women with preeclampsia, but not affected them from normotensive pregnancy. The prophylactic administration of H 2 attenuated placental ischemia-induced hypertension, angiogenic imbalance, and oxidative stress. These results support the theory that H 2 has a potential benefit in the prevention of preeclampsia. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. 1H nuclear magnetic resonance studies of sarcoplasmic oxygenation in the red cell-perfused rat heart

    OpenAIRE

    Jelicks, L.A.; Wittenberg, B.A.

    1995-01-01

    The proximal histidine N delta H proton of deoxymyoglobin experiences a large hyperfine shift resulting in its 1H nuclear magnetic resonance (NMR) signal appearing at approximately 76 ppm (at 35 degrees C), downfield of the diamagnetic spectral region. 1H NMR of this proton is used to monitor sarcoplasmic oxygen pressure in isolated perfused rat heart. This method monitors intracellular oxygenation in the whole heart and does not reflect oxygenation in a limited region. The deoxymyoglobin res...

  1. The VGF-Derived Neuropeptide TLQP-21 Shows No Impact on Hormone Secretion in the Isolated Perfused Rat Pancreas

    DEFF Research Database (Denmark)

    Christiansen, Charlotte Bayer; Svendsen, B; Holst, Jens Juul

    2015-01-01

    investigated the impact of TLQP-21 on insulin, glucagon, and somatostatin secretion in the perfused rat pancreas. We found that administration of 5 and 50 nM TLQP-21 had no impact on pancreatic hormone secretion at 3.5 or 8 mM glucose levels. Increasing TLQP-21 (200 nM) and glucose concentration (3.5 and 16 m...

  2. 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

  3. An exploration of the control of micturition using a novel in situ arterially perfused rat preparation

    Directory of Open Access Journals (Sweden)

    Prajni eSadananda

    2011-05-01

    Full Text Available Our goal was to develop and refine a decerebrate arterially perfused rat preparation (DAPR that allows the complete bladder filling and voiding cycle to be investigated without some of the restrictions inherent with in vivo experimentation (e.g. ease and speed of set up (30mins, control over the extracellular milieu and free of anaesthetic agents. Both spontaneous (naturalistic bladder filling from ureters and evoked (in response to intravesical infusion voids were routinely and reproducibly observed which had similar pressure characteristics. The DAPR allows the simultaneous measurement of bladder intra-luminal pressure, external urinary sphincter electromyogram (EUS–EMG, pelvic afferent nerve activity, pudendal motor activity and permits excellent visualisation of the entire lower urinary tract, during typical rat filling and voiding responses. The voiding responses were modulated or eliminated by interventions at a number of levels including at the afferent terminal fields (intravesical capsaicin sensitisation-desensitisation, autonomic (ganglion blockade with hexamethonium and somatic motor (vecuronium block of the EUS outflow and required intact brainstem/hindbrain-spinal coordination (as demonstrated by sequential hindbrain transections. Both innocuous (eg perineal stimulation and noxious (tail/paw pinch somatic stimuli elicited an increase in EUS-EMG indicating intact sensory feedback loops. Spontaneous non-micturition contractions were observed between fluid infusions at a frequency and amplitude of 1.4±0.9 per minute and 1.4±0.3mmHg, respectively, and their amplitude increased when autonomic control was compromised. In conclusion, the DAPR is a tractable and useful model for the study of neural bladder control showing intact afferent signaling, spinal and hindbrain co-ordination and efferent control over the lower urinary tract end organs and can be extended to study bladder pathologies and trial novel treatments.

  4. 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

  5. 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.

  6. Effect of ADH on rubidium transport in isolated perfused rat cortical collecting tubules

    International Nuclear Information System (INIS)

    Schafer, J.A.; Troutman, S.L.

    1986-01-01

    Unidirectional fluxes of 86Rb+ were measured as an indicator of potassium transport in isolated rat cortical collecting tubules perfused and bathed at 38 degrees C with isotonic solutions in which Rb+ replaced K+. Under control conditions the lumen-to-bath flux (Jl----b) was significantly less than the bath-to-lumen flux (Jb----l), indicating net Rb+ secretion. Net secretion increased approximately 180% after addition of 100 microU/ml of arginine vasopressin (ADH) to the bathing solution, due to a rapid and reversible increase in Jb----l from 4.6 +/- 0.8 to 9.0 +/- 1.9 pmol X min-1 X mm-1 with no significant change in Jl----b. The ADH effect was completely inhibited by 2 mM luminal Ba2+. The average transepithelial voltage (Ve) was not significantly different from zero in the control period but became lumen negative (-5 to -10 mV) after ADH. With 10(-5) M amiloride in the lumen Ve was lumen positive (+2 to +4 mV) and was unaltered by ADH or Ba2+, yet ADH produced a significant but attentuated increase in Jb----l with no change in Jl----b. The results indicate that ADH augments net K+ secretion either by an increase in the Ba2+-sensitive conductance of the apical membrane or by an increase in the electrochemical potential driving force for net Rb+ secretion through this pathway

  7. 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)

  8. Kinetic analysis of zinc uptake and serosal transfer by vascularly perfused rat intestine

    International Nuclear Information System (INIS)

    Hoadley, J.E.; Leinart, A.S.; Cousins, R.J.

    1987-01-01

    Transport kinetics were examined for uptake of 65 Zn from the lumen and for transport of mucosal 65 Zn subsequent to uptake in the isolated, vascularly perfused intestines of rats fed either a zinc-deficient or zinc-adequate diet. Zinc depletion influenced the intestinal transport of zinc by 1) stimulating a saturable uptake mechanisms, 2) reducing secretion of mucosal 65 Zn into the lumen, and 3) increasing the rate of 65 Zn turnover in a rapidly absorbed mucosal zinc compartment. Uptake of 65 Zn involved both saturable and nonsaturable processes. The saturable process was stimulated by zinc depletion with the apparent maximal transport rate for the saturable mechanism increasing from 60 to 180 nmol Zn x g -1 x 30 min -1 . Most of the 65 Zn taken up was not involved in the short-term secretion or absorption, and mucosal 65 Zn retention was independent of dietary zinc status. Absorption of mucosal 65 Zn was nonsaturable, involved a rapid exchanging zinc compartment, and was stimulated by zinc depletion. The half-life for 65 Zn in this mucosal zinc compartment was ∼ 24 min in the zinc-adequate group and 13 min in the zinc-depleted group

  9. Role of pressure in angiotensin II-induced renal injury: chronic servo-control of renal perfusion pressure in rats.

    Science.gov (United States)

    Mori, Takefumi; Cowley, Allen W

    2004-04-01

    Renal perfusion pressure was servo-controlled chronically in rats to quantify the relative contribution of elevated arterial pressure versus angiotensin II (Ang II) on the induction of renal injury in Ang II-induced hypertension. Sprague-Dawley rats fed a 4% salt diet were administered Ang II for 14 days (25 ng/kg per minute IV; saline only for sham rats), and the renal perfusion pressure to the left kidney was continuously servo-controlled to maintain a normal pressure in that kidney throughout the period of hypertension. An aortic occluder was implanted around the aorta between the two renal arteries and carotid and femoral arterial pressure were measured continuously throughout the experiment to determine uncontrolled and controlled renal perfusion pressure, respectively. Renal perfusion pressure of uncontrolled, controlled, and sham kidneys over the period of Ang II or saline infusion averaged 152.6+/-7.0, 117.4+/-3.5, and 110.7+/-2.2 mm Hg, respectively. The high-pressure uncontrolled kidneys exhibited tubular necrosis and interstitial fibrosis, especially prominent in the outer medullary region. Regional glomerular sclerosis and interlobular artery injury were also pronounced. Controlled kidneys were significantly protected from interlobular artery injury, juxtamedullary glomeruli injury, tubular necrosis, and interstitial fibrosis as determined by comparing the level of injury. Glomerular injury was not prevented in the outer cortex. Transforming growth factor (TGF)-beta and active NF-kappaB proteins determined by immunohistochemistry were colocalized in the uncontrolled kidney in regions of interstitial fibrosis. We conclude that the preferential juxtamedullary injury found in Ang II hypertension is largely induced by pressure and is probably mediated through the TGF-beta and NF-kappaB pathway.

  10. Extracellular Vesicles from Human Liver Stem Cells Reduce Injury in an Ex Vivo Normothermic Hypoxic Rat Liver Perfusion Model.

    Science.gov (United States)

    Rigo, Federica; De Stefano, Nicola; Navarro-Tableros, Victor; David, Ezio; Rizza, Giorgia; Catalano, Giorgia; Gilbo, Nicholas; Maione, Francesca; Gonella, Federica; Roggio, Dorotea; Martini, Silvia; Patrono, Damiano; Salizzoni, Mauro; Camussi, Giovanni; Romagnoli, Renato

    2018-05-01

    The gold standard for organ preservation before transplantation is static cold storage, which is unable to fully protect suboptimal livers from ischemia/reperfusion injury. An emerging alternative is normothermic machine perfusion (NMP), which permits organ reconditioning. Here, we aimed to explore the feasibility of a pharmacological intervention on isolated rat livers by using a combination of NMP and human liver stem cells-derived extracellular vesicles (HLSC-EV). We established an ex vivo murine model of NMP capable to maintain liver function despite an ongoing hypoxic injury induced by hemodilution. Livers were perfused for 4 hours without (control group, n = 10) or with HLSC-EV (treated group, n = 9). Bile production was quantified; perfusate samples were collected hourly to measure metabolic (pH, pO2, pCO2) and cytolysis parameters (AST, alanine aminotransferase, lactate dehydrogenase). At the end of perfusion, we assessed HLSC-EV engraftment by immunofluorescence, tissue injury by histology, apoptosis by terminal deoxynucleotidyl transferase dUTP nick-end labeling assay, tissue hypoxia-inducible factor 1-α, and transforming growth factor-beta 1 RNA expression by quantitative reverse transcription-polymerase chain reaction. During hypoxic NMP, livers were able to maintain homeostasis and produce bile. In the treated group, AST (P = 0.018) and lactate dehydrogenase (P = 0.032) levels were significantly lower than those of the control group at 3 hours of perfusion, and AST levels persisted lower at 4 hours (P = 0.003). By the end of NMP, HLSC-EV had been uptaken by hepatocytes, and EV treatment significantly reduced histological damage (P = 0.030), apoptosis (P = 0.049), and RNA overexpression of hypoxia-inducible factor 1-α (P < 0.0001) and transforming growth factor-beta 1 (P = 0.014). HLSC-EV treatment, even in a short-duration model, was feasible and effectively reduced liver injury during hypoxic NMP.

  11. Normothermic machine perfusion reduces bile duct injury and improves biliary epithelial function in rat donor livers.

    Science.gov (United States)

    Op den Dries, Sanna; Karimian, Negin; Westerkamp, Andrie C; Sutton, Michael E; Kuipers, Michiel; Wiersema-Buist, Janneke; Ottens, Petra J; Kuipers, Jeroen; Giepmans, Ben N; Leuvenink, Henri G D; Lisman, Ton; Porte, Robert J

    2016-07-01

    Bile duct injury may occur during liver procurement and transplantation, especially in livers from donation after circulatory death (DCD) donors. Normothermic machine perfusion (NMP) has been shown to reduce hepatic injury compared to static cold storage (SCS). However, it is unknown whether NMP provides better preservation of bile ducts. The aim of this study was to determine the impact of NMP on bile duct preservation in both DCD and non-DCD livers. DCD and non-DCD livers obtained from Lewis rats were preserved for 3 hours using either SCS or NMP, followed by 2 hours ex vivo reperfusion. Biomarkers of bile duct injury (gamma-glutamyltransferase and lactate dehydrogenase in bile) were lower in NMP-preserved livers compared to SCS-preserved livers. Biliary bicarbonate concentration, reflecting biliary epithelial function, was 2-fold higher in NMP-preserved livers (P bile was significantly higher in NMP-preserved livers (7.63 ± 0.02 and 7.74 ± 0.05 for non-DCD and DCD livers, respectively) compared with SCS-preserved livers (7.46 ± 0.02 and 7.49 ± 0.04 for non-DCD and DCD livers, respectively). Scanning and transmission electron microscopy of donor extrahepatic bile ducts demonstrated significantly decreased injury of the biliary epithelium of NMP-preserved donor livers (including the loss of lateral interdigitations and mitochondrial injury). Differences between NMP and SCS were most prominent in DCD livers. Compared to conventional SCS, NMP provides superior preservation of bile duct epithelial cell function and morphology, especially in DCD donor livers. By reducing biliary injury, NMP could have an important impact on the utilization of DCD livers and outcome after transplantation. Liver Transplantation 22 994-1005 2016 AASLD. © 2016 American Association for the Study of Liver Diseases.

  12. 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)

  13. Perfusion imaging using rubidium-82 ((82)Rb) PET in rats with myocardial infarction

    DEFF Research Database (Denmark)

    Clemmensen, Andreas Ettrup; Ghotbi, Adam Ali; Bodholdt, Rasmus Poul

    2017-01-01

    Assessing myocardial perfusion using 82Rb-PET is emerging as a valuable clinical tool.1,2 The rapid decay (T½ = 76 s) allows for absolute quantification of both rest and stress perfusion within 30 minutes. In addition to evaluation of epicardial disease with perfusion defects, also evaluation...... of balanced coronary and small vessel disease is possible. For further evaluation of how 82Rb-PET can be used clinically, pre-clinical application of the method would be valuable. However, so far no data on the use of 82Rb-PET in small animals have been published nor has the use of 82Rb-PET, to the best...

  14. Impaired microcirculatory perfusion in a rat model of cardiopulmonary bypass : the role of hemodilution

    NARCIS (Netherlands)

    Koning, Nick J.; de lange, Fellery; Vonk, Alexander B. A.; Ahmed, Yunus; van den Brom, Charissa E.; Bogaards, Sylvia; van Meurs, Matijs; Jongman, Rianne M.; Schalkwijk, Casper G.; Begieneman, Mark P. V.; Niessen, Hans W.; Baufreton, Christophe; Boer, Christa

    2016-01-01

    Although hemodilution is attributed as the main cause of microcirculatory impairment during cardiopulmonary bypass (CPB), this relationship has never been investigated. We investigated the distinct effects of hemodilution with or without CPB on microvascular perfusion and subsequent renal tissue

  15. 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

  16. Role of glycolysis in maintenance of the action potential duration and contractile activity in isolated perfused rat heart.

    Science.gov (United States)

    Opie, L H; Tuschmidt, R; Bricknell, O; Girardier, L

    1980-01-01

    1. Changing substrates from glucose to pyruvate in paced isolated rat hearts, perfused by the Langendorff technique at 65 cm H2O with a Krebs-Henseleit bicarbonate buffer, produced effects which are opposite to those of ouabain treatment: negative inotropy, decreased work efficiency, hyperpolarization, increased maximum rate of rise and amplitude of the action potential, increased conduction velocity. 2. All the effects resulting from perfusion with pyruvate can be reversed by adding ouabain at a concentration of 100 microM. 3. The correlation between various tissue metabolises and change in contractile force (delta F), rate of tension development [maximum + (dF/dt)] and rate of relaxation [maximum -(dF/dt)] was studied by multiple linear regression. No significant correlation was found with either glycogen content and tissue lactate or with cAMP and cGMP. A weak negative correlation was found with ATP and phosphocreatine. The strongest correlation was found 76 to 807 nM/g in passing from glucose- to pyruvate-containing perfusion solution. 4. In vitro tests performed with a solution containing high energy phosphates and magnesium at concentrations equal to their calculated values in the cytosol (pH 7.0) showed that a significant negative correlation exists between citrate concentration (range: 1 and 1500 M) and free calcium concentration in the micromole range. 5. It is concluded that the effects of pyruvate (non glucose substrate) perfusion could be mediated by a decrease in cytosolic-free calcium resulting from an increase in intracellular citrate. The observation that all these effects can be reversed by ouabain is taken as a circumstantial evidence of a common mechanism.

  17. 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

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

    Science.gov (United States)

    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.

  19. NMR study of damage on isolated perfused rat heart exposed to ischemia and hypoxia

    International Nuclear Information System (INIS)

    Luo Xuechun; Yan Yongbin; Zhang Riqing; Fan Lili

    2001-01-01

    Myocardial ischemia is the most common and primary cause of myocardium damage. Numerous conventional techniques and methods have been developed for ischemia and reperfusion studies. However, because of damage to the heart sample, most of these techniques can not be used to continuously monitor the full dynamic course of the myocardial metabolic pathway. The nuclear magnetic resonance (NMR) surface coil technique, which overcomes the limitations of conventional instrumentation, can be used to quantitatively study every stage of the perfused heart (especially after perfusion stoppage) continuously, dynamically, and without damage under normal or designed physiological conditions at the molecular level. In this paper, 31 P-NMR was used to study the effects of ischemia and hypoxia on isolated perfused hearts. The results show that complete hypoxia caused more severe functional damage to the myocardial cells than complete ischemia

  20. Absorption kinetics of vitamin E nanoemulsion and green tea microstructures by intestinal in situ single perfusion technique in rats.

    Science.gov (United States)

    Saratale, Rijuta Ganesh; Lee, Hee-Seok; Koo, Yong Eui; Saratale, Ganesh Dattatraya; Kim, Young Jun; Imm, Jee Young; Park, Yooheon

    2018-04-01

    The absorption kinetics of food ingredients such as nanoemulsified vitamin E and green tea microstructures were evaluated by the intestinal in situ single perfusion technique. Absorption rate, sub-acute oral toxicity and organ morphology in a rat model were examined. The intestinal in situ single perfusion technique and HPLC analysis were applied to investigate the absorption rate of selected materials by examining time-dependent changes in the serum levels of catechin and dl-α-tocopherol. The acute toxicity test and histopathological evaluation were applied to analyze the safety of microsized green tea and nanosized vitamin E in a rat model. Total serum dl-α-tocopherol levels significantly increased with nanosized vitamin E administration (PE until 90min after administration showed significantly increased absorption rate of serum dl-α-tocopherol levels at each time point (10min interval) (PE and microsized green tea did not show signs of acute toxicity or death after 14days of observation. In addition, macroscopic analysis showed that there were no changes in representative organ sections of rats following the oral administration of food-related nanoscale materials. We successfully demonstrated that using nanosized vitamin E increased absorption rate to a greater extent than normal food-related material, and these results occurs via safety analyses on food-related nanoscale materials for human consumption. These results could be useful for the design and development of novel nanoemulsified vitamin E and microsized green tea formulations that can overcome the problem of their bioavailability and improve their efficacy while still maintaining their essential therapeutic efficacies. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. 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

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

    Science.gov (United States)

    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

  3. Contractile responses to ergotamine and dihydroergotamine in the perfused middle cerebral artery of rat

    DEFF Research Database (Denmark)

    Tfelt-Hansen, Peer; Nilsson, Elisabeth; Edvinsson, Lars

    2007-01-01

    mmHg and luminally perfused. All vessels used attained spontaneous contractile tone (34.9+/-1.8% of resting tone) and responded to luminal adenosine triphosphate (ATP) with dilatation (24.1+/-4.0%), which showed functioning endothelium. Luminally added ergotamine or DHE induced maximal contractions...

  4. 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

  5. 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.

  6. Effects of regional cerebral blood flow perfusion on learning and memory function and its molecular mechanism in rats

    Institute of Scientific and Technical Information of China (English)

    Cunli Xu; Wenhua Wu; Lingbin Kong

    2016-01-01

    Objective:To study the effects of regional cerebral blood flow (rCBF) perfusion on learning and memory function in special brain areas and its molecular mechanism in rat. Methods: Sixty-four adult male healthy Sprague-Dawley (SD) rats were randomly divided into two groups: Afalse operation group and an operation group. The false operation group was randomly divided into four subgroups (A0, B0, C0, and D0) and the operation group was randomly divided into four subgroups (A, B, C, and D), with eight rats in each subgroup. The operation group underwent bilateral common carotid artery permanent ligation, while the other group only underwent a skin incision without the bilateral common carotid artery permanent ligation. Learning memory function of rats in each subgroup was measured using a Y-maze at 4 h, 8 h, 24 h, and 3 days after surgery. The rCBF in the right frontal lobe and hippocampus was detected using the Periflux PF model laser Doppler flowmetry and c-fos, c-jun, Bcl-2, and Bax protein expression in the right frontal lobe and hippocampus was measured using immunohistochemistry. Results: The rCBF in the right frontal lobule division and right hippocampus division was significantly lower in the operation group than in the false operation group (P Conclusions:rCBF decrease can impair learning and memory function in rats, which may be related to the increased expression of c-fos, c-jun, Bcl-2, and Bax proteins in the frontal cortex and hippocampus.

  7. Dissociation of brain edema induced by cold injury in rat model. MR imaging and perfusion studies with 14C-iodo-antipyrine

    International Nuclear Information System (INIS)

    Itabashi, Yoko; Prado, G.L.M.; Abo, Mitsuru; Miura, Hiroyuki; Abe, Yoshinao

    2001-01-01

    The purpose of this study is to confirm whether T2-weighted imaging and perfusion imaging, i.e. autoradiogram of 14 C-iodoantipyrine, on the course of brain edema correspond to each other or not. Cold injured rat brains were used as a model and were sequentially examined by both methods and compared with each other and with histological specimens. Special focus relies on the time changes in the lesions. High SI of T2-weighted images were observed and the percentages in the high SI area to the total brain area in the same slice were 4.7±0.31, 5.6±0.46 and 3.4±0.42 for 6, 24 and 48 hours, respectively. By contrast, low perfusion areas were indicated in the perfusion study and their percentages were 4.6±0.55, 5.6±0.86 and 2.4±0.35 for 6, 24 and 48 hours, respectively. At 48 hours after cold injury, low perfusion areas were smaller than high SI areas. Moreover, high accumulation areas consisting of macrophages were observed surrounding necrosis. It is concluded that there is dissociation between perfusion and T2-weighted MR imaging, where the collection of macrophages surrounding edema lesions and necrosis had the same appearance on MRI and different accumulations on perfusion studies. (author)

  8. 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

  9. 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

  10. The effect of amperozide on uptake and release of [3H]-dopamine in vitro from perfused rat striatal and limbic brain areas

    International Nuclear Information System (INIS)

    Eriksson, E.; Christensson, E.

    1990-01-01

    Amperozide, a putatively antipsychotic drug, was studied for its effects on uptake and release of [ 3 H]-dopamine in rat brain in vitro. Amperozide inhibited uptake of [ 3 H]-dopamine in striatal chopped tissue in vitro with an IC 50 of 18 μM. It also increased basal release of [ 3 H]-dopamine from perfused rat striatal and limbic tissue in vitro at concentrations above 5 μM. Release of [ 3 H]-dopamine from perfused rat striatal and limbic tissue stimulated with 5 μM amphetamine, was inhibited by 1 μM amperozide to 46%. No significant difference was found for the effect of amperozide on in vitro release of [ 3 H]-dopamine from corpus striatum compared to tissue from limbic grain regions; neither on basal release nor on amphetamine-stimulated release of dopamine. (author)

  11. Comparison of the gravimetric, phenol red, and 14C-PEG-3350 methods to determine water absorption in the rat single-pass intestinal perfusion model

    OpenAIRE

    Sutton, Steven C.; Rinaldi, M. T. S.; Vukovinsky, K. E.

    2001-01-01

    This study was undertaken to determine whether the gravimetric method provided an accurate measure of water flux correction and to compare the gravimetric method with methods that employ nonabsorbed markers (eg, phenol red and 14C-PEG-3350). Phenol red, 14C-PEG-3350, and 4-[2-[[2-(6-amino-3-pyridinyl)-2-hydroxyethyl]amino]ethoxy]-methyl ester, (R)-benzene acetic acid (Compound I) were co-perfused in situ through the jejunum of 9 anesthetized rats (single-pass intestinal perfusion [SPIP]). Wat...

  12. Extracellular Matrix Hydrogel Promotes Tissue Remodeling, Arteriogenesis, and Perfusion in a Rat Hindlimb Ischemia Model

    Directory of Open Access Journals (Sweden)

    Jessica L. Ungerleider, BS

    2016-01-01

    Full Text Available Although surgical and endovascular revascularization can be performed in peripheral arterial disease (PAD, 40% of patients with critical limb ischemia do not have a revascularization option. This study examines the efficacy and mechanisms of action of acellular extracellular matrix-based hydrogels as a potential novel therapy for treating PAD. We tested the efficacy of using a tissue-specific injectable hydrogel derived from decellularized porcine skeletal muscle (SKM and compared this to a new human umbilical cord-derived matrix (hUC hydrogel, which could have greater potential for tissue regeneration because of the younger age of the tissue source. In a rodent hindlimb ischemia model, both hydrogels were injected 1-week post-surgery and perfusion was regularly monitored with laser speckle contrast analysis to 35 days post-injection. There were significant improvements in hindlimb tissue perfusion and perfusion kinetics with both biomaterials. Histologic analysis indicated that the injected hydrogels were biocompatible, and resulted in arteriogenesis, rather than angiogenesis, as well as improved recruitment of skeletal muscle progenitors. Skeletal muscle fiber morphology analysis indicated that the muscle treated with the tissue-specific SKM hydrogel more closely matched healthy tissue morphology. Whole transcriptome analysis indicated that the SKM hydrogel caused a shift in the inflammatory response, decreased cell death, and increased blood vessel and muscle development. These results show the efficacy of an injectable ECM hydrogel alone as a potential therapy for treating patients with PAD. Our results indicate that the SKM hydrogel improved functional outcomes through stimulation of arteriogenesis and muscle progenitor cell recruitment.

  13. The Hepatoprotection Provided by Taurine and Glycine against Antineoplastic Drugs Induced Liver Injury in an Ex Vivo Model of Normothermic Recirculating Isolated Perfused Rat Liver

    Directory of Open Access Journals (Sweden)

    Reza Heidari

    2016-03-01

    Full Text Available Taurine (2-aminoethane sulfonic acid is a non-protein amino acid found in high concentration in different tissues. Glycine (Amino acetic acid is the simplest amino acid incorporated in the structure of proteins. Several investigations indicate the hepatoprotective properties of these amino acids. On the other hand, antineoplastic agents-induced serum transaminase elevation and liver injury is a clinical complication. The current investigation was designed to screen the possible hepatoprotective properties of taurine and glycine against antineoplastic drugs-induced hepatic injury in an ex vivo model of isolated perfused rat liver. Rat liver was perfused with different concentration (10 μM, 100 μM and 1000 μM of antineoplastic drugs (Mitoxantrone, Cyclophosphamide, Cisplatin, 5 Fluorouracil, Doxorubicin and Dacarbazine via portal vein. Taurine and glycine were administered to drug-treated livers and liver perfusate samples were collected for biochemical measurements (ALT, LDH, AST, and K+. Markers of oxidative stress (reactive oxygen species formation, lipid peroxidation, total antioxidant capacity and glutathione were also assessed in liver tissue. Antineoplastic drugs caused significant pathological changes in perfusate biochemistry. Furthermore, markers of oxidative stress were significantly elevated in drug treated livers. It was found that taurine (5 and 10 mM and glycine (5 and 10 mM administration significantly mitigated the biomarkers of liver injury and attenuated drug induced oxidative stress. Our data indicate that taurine and glycine supplementation might help as potential therapeutic options to encounter anticancer drugs-induced liver injury.

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

    Science.gov (United States)

    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.

  15. Effects of Scirpusin B, a polyphenol in passion fruit seeds, on the coronary circulation of the isolated perfused rat heart

    Directory of Open Access Journals (Sweden)

    Yutaka Matsumoto, Nozomi Gotoh, Shoko Sano, Kenkichi Sugiyama, Tatsuhiko Ito, Yohei Abe, Yumi Katano, Akira Ishihata

    2014-07-01

    Full Text Available Objective: Piceatannol, a polyphenol which is contained in passion fruits seed, is a derivative of resveratrol and is known to have antioxidant, anti-inflammatory and vasorelaxing activities. Passion fruits seed also contains a dimer of Piceatannol, Scirpusin B. The aim of this study was to investigate the effect of Scirpusin B on the coronary circulation of the isolated rat heart. Methods: Hearts were isolated from male Fischer 344 rats (5 – 6 months old, and perfused with modified Krebs-Henseleit solution aerated with 95% O2 and 5% CO2 (37 °C at constant pressure (75 cmH2O by Langendorff’s method. Piceatannol or Scirpusin B (10, 30 and 100 μM was injected as a bolus into the aortic cannula and coronary flow (CF was continuously measured by the electromagnetic flow meter. In some experiments, rat hearts were pretreated with L-NAME (an inhibitor of nitric oxide synthase or Diclofenac (an inhibitor of cyclooxygenase to reveal the possible involvement of nitric oxide (NO and vasodilating prostanoids in the effect of Scirpusin B. Results: Scirpusin B increased CF up to 108.2 % of the initial value, while Piceatannol did not increase CF. In addition; Scirpusin B increased CF concentration-dependently. Pretreatment with L-NAME or Diclofenac significantly attenuated the Scirpusin B-induced coronary vasodilatation. Scirpusin B did not change the heart rate either left ventricular pressure. Conclusion: This study shows that Scirpusin B could increase CF via production of NO and vasodilating prostanoids.

  16. Effects of regional cerebral blood flow perfusion on learning and memory function and its molecular mechanism in rats

    Institute of Scientific and Technical Information of China (English)

    Cunli Xu; Wenhua Wu; Lingbin Kong

    2016-01-01

    Objective:To study the effects of regional cerebral blood flow(r CBF)perfusion on learning and memory function in special brain areas and its molecular mechanism in rat.Methods:Sixty-four adult male healthy Sprague-Dawley(SD)rats were randomly divided into two groups:A false operation group and an operation group.The false operation group was randomly divided into four subgroups(A0,B0,C0,and D0)and the operation group was randomly divided into four subgroups(A,B,C,and D),with eight rats in each subgroup.The operation group underwent bilateral common carotid artery permanent ligation,while the other group only underwent a skin incision without the bilateral common carotid artery permanent ligation.Learning memory function of rats in each subgroup was measured using a Y-maze at 4 h,8 h,24 h,and 3 days after surgery.The r CBF in the right frontal lobe and hippocampus was detected using the Periflux PF model laser Doppler flowmetry and c-fos,c-jun,Bcl-2,and Bax protein expression in the right frontal lobe and hippocampus was measured using immunohistochemistry.Results:The r CBF in the right frontal lobule division and right hippocampus division was significantly lower in the operation group than in the false operation group(P<0.05).The error number(EN),time to reach the target,and total reaction time(TRT)for the learning index using the Y-type labyrinth test in the operation group were significantly higher than that in the false operation group(P<0.05);however,the active avoid rate in the operation group was significantly lower than that of the false operation group.Expression of c-fos and c-jun as well as the average absorbency in the right frontal lobule division and right hippocampus division in the operation group were significantly higher than those in the false operation group(P<0.05).The number of Bax and Bcl-2-positive cells was significantly higher in the operation group,and the expression ratio of Bax/Bcl-2 in the operation

  17. Transplantation of Rat Mesenchymal Stem Cells Overexpressing Hypoxia-Inducible Factor 2α Improves Blood Perfusion and Arteriogenesis in a Rat Hindlimb Ischemia Model

    Directory of Open Access Journals (Sweden)

    Weifeng Lu

    2017-01-01

    Full Text Available Mesenchymal stem cells (MSCs have been increasingly tested in cell-based therapy to treat numerous diseases. Genetic modification to improve MSC behavior may enhance posttransplantation outcome. This study aims to test the potential therapeutic benefits of rat bone marrow MSCs overexpressing hypoxia-inducible factor 2α (rMSCsHIF-2α in a rat hindlimb ischemia model. PBS, rMSCs, or rMSCsHIF-2α were injected into rat ischemic hindlimb. Compared with the injection of PBS or rMSCs, transplantation of rMSCsHIF-2α significantly improved blood perfusion, increased the number of vessel branches in the muscle of the ischemic hindlimb, and improved the foot mobility of the ischemic hindlimb (all P<0.05. rMSCHIF-2α transplantation also markedly increased the expression of proangiogenic factors VEGF, bFGF, and SDF1 and Notch signaling proteins including DII4, NICD, Hey1, and Hes1, whereas it reduced the expression of proapoptotic factor Bax in the muscle of the ischemic hindlimb. Overexpression of HIF-2α did not affect rMSC stemness and proliferation under normoxia but significantly increased rMSC migration and tube formation in matrigel under hypoxia (all P<0.05. RMSCsHIF-2α stimulated endothelial cell invasion under hypoxia significantly (P<0.05. Genetic modification of rMSCs via overexpression of HIF-2α improves posttransplantation outcomes in a rat hindlimb ischemia model possibly by stimulating proangiogenic growth factors and cytokines.

  18. Segmental-dependent membrane permeability along the intestine following oral drug administration: Evaluation of a triple single-pass intestinal perfusion (TSPIP) approach in the rat.

    Science.gov (United States)

    Dahan, Arik; West, Brady T; Amidon, Gordon L

    2009-02-15

    In this paper we evaluate a modified approach to the traditional single-pass intestinal perfusion (SPIP) rat model in investigating segmental-dependent permeability along the intestine following oral drug administration. Whereas in the traditional model one single segment of the intestine is perfused, we have simultaneously perfused three individual segments of each rat intestine: proximal jejunum, mid-small intestine and distal ileum, enabling to obtain tripled data from each rat compared to the traditional model. Three drugs, with different permeabilities, were utilized to evaluate the model: metoprolol, propranolol and cimetidine. Data was evaluated in comparison to the traditional method. Metoprolol and propranolol showed similar P(eff) values in the modified model in all segments. Segmental-dependent permeability was obtained for cimetidine, with lower P(eff) in the distal parts. Similar P(eff) values for all drugs were obtained in the traditional method, illustrating that the modified model is as accurate as the traditional, throughout a wide range of permeability characteristics, whether the permeability is constant or segment-dependent along the intestine. Three-fold higher statistical power to detect segmental-dependency was obtained in the modified approach, as each subject serves as his own control. In conclusion, the Triple SPIP model can reduce the number of animals utilized in segmental-dependent permeability research without compromising the quality of the data obtained.

  19. Effect of bicarbonate on potassium conductance of isolated perfused rat pancreatic ducts

    DEFF Research Database (Denmark)

    Novak, I; Greger, R

    1991-01-01

    dissected from rat pancreas. The basolateral membrane potential PDbl of unstimulated duct cells was between -60 mV and -70 mV, and the cells had a relatively large K+ conductance in the basolateral membrane as demonstrated by (a) 20-22 mV depolarization of PDbl in response to increase in bath K...

  20. 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

  1. 13C and 31P NMR study of gluconeogenesis: utilization of 13C-labeled substrates by perfused liver from streptozotocin-diabetic and untreated rats

    International Nuclear Information System (INIS)

    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

  2. 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

  3. 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

  4. Using synchrotron radiation angiography with a highly sensitive detector to identify impaired peripheral perfusion in rat pulmonary emphysema

    International Nuclear Information System (INIS)

    Ito, Hiromichi; Matsushita, Shonosuke; Hyodo, Kazuyuki; Sato, Yukio; Sakakibara, Yuzuru

    2013-01-01

    Synchrotron radiation angiography with a HARP detector made it possible to evaluate impaired pulmonary microcirculation in pulmonary emphysema by means of high sensitivity. Owing to limitations in spatial resolution and sensitivity, it is difficult for conventional angiography to detect minute changes of perfusion in diffuse lung diseases, including pulmonary emphysema (PE). However, a high-gain avalanche rushing amorphous photoconductor (HARP) detector can give high sensitivity to synchrotron radiation (SR) angiography. SR angiography with a HARP detector provides high spatial resolution and sensitivity in addition to time resolution owing to its angiographic nature. The purpose of this study was to investigate whether this SR angiography with a HARP detector could evaluate altered microcirculation in PE. Two groups of rats were used: group PE and group C (control). Transvenous SR angiography with a HARP detector was performed and histopathological findings were compared. Peak density of contrast material in peripheral lung was lower in group PE than group C (p < 0.01). The slope of the linear regression line in scattering diagrams was also lower in group PE than C (p < 0.05). The correlation between the slope and extent of PE in histopathology showed significant negative correlation (p < 0.05, r = 0.61). SR angiography with a HARP detector made it possible to identify impaired microcirculation in PE by means of its high spatial resolution and sensitivity

  5. Using synchrotron radiation angiography with a highly sensitive detector to identify impaired peripheral perfusion in rat pulmonary emphysema

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hiromichi [University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575 (Japan); Matsushita, Shonosuke, E-mail: shomatsu@md.tsukuba.ac.jp [University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575 (Japan); Tsukuba University of Technology, Tsukuba, Ibaraki 305-8521 (Japan); Hyodo, Kazuyuki [High Energy Accelerator Research Organization, KEK, Tsukuba, Ibaraki 305-0801 (Japan); Sato, Yukio; Sakakibara, Yuzuru [University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575 (Japan)

    2013-03-01

    Synchrotron radiation angiography with a HARP detector made it possible to evaluate impaired pulmonary microcirculation in pulmonary emphysema by means of high sensitivity. Owing to limitations in spatial resolution and sensitivity, it is difficult for conventional angiography to detect minute changes of perfusion in diffuse lung diseases, including pulmonary emphysema (PE). However, a high-gain avalanche rushing amorphous photoconductor (HARP) detector can give high sensitivity to synchrotron radiation (SR) angiography. SR angiography with a HARP detector provides high spatial resolution and sensitivity in addition to time resolution owing to its angiographic nature. The purpose of this study was to investigate whether this SR angiography with a HARP detector could evaluate altered microcirculation in PE. Two groups of rats were used: group PE and group C (control). Transvenous SR angiography with a HARP detector was performed and histopathological findings were compared. Peak density of contrast material in peripheral lung was lower in group PE than group C (p < 0.01). The slope of the linear regression line in scattering diagrams was also lower in group PE than C (p < 0.05). The correlation between the slope and extent of PE in histopathology showed significant negative correlation (p < 0.05, r = 0.61). SR angiography with a HARP detector made it possible to identify impaired microcirculation in PE by means of its high spatial resolution and sensitivity.

  6. [Determination of H2S in Rat Intestinal Perfusion Solution Based on Fluorescence Analysis].

    Science.gov (United States)

    Hou, Jun-feng; Li, Xin-xia; Shen, Xue-ru; Huojia, Miliban; Guan, Ming

    2015-08-01

    Under alkaline conditions, Fluorescein mercury has strong fluorescence, however, when it met S(2-), its fluorescence would quench, in view of the above, a fluorescence method for determination of H2S in biological samples was established. In the 0.1 mol · L(-1) NaOH dilution, when the concentration of fluorescein Mercury and Na2S was 5.0 × 10(-5) and 1.0 × 10(-5) mol · L(-1) respectively, the fluorescence intensity of system was determined at 522 nm. The results showed that, at the range of 4.0 × 10(-7)~2.0 × 10(-6) mol · L(-1), the concentration decreasing of H2S and fluorescence intensity had good linear relationship, r=0.9980, the RSD of precision test was 4.59% (n=7), the detection limit was 3.5 × 10(-8) mol · L(-1), the content of H2S in the sample were 1.01 × 10(-6) and 1.15 × 10(-6) mol · L(-1), and the recovery rate was 95.8%~101.0%, the method has the advantages of simple operation, high sensitivity, good selectivity, can accurately determine of H2S in intestinal perfused solution, and provides the basis for the determination of endogenous H2S.

  7. Combined, but not individual, blockade of ASIC3, P2X, and EP4 receptors attenuates the exercise pressor reflex in rats with freely perfused hindlimb muscles.

    Science.gov (United States)

    Stone, Audrey J; Copp, Steven W; Kim, Joyce S; Kaufman, Marc P

    2015-12-01

    In healthy humans, tests of the hypothesis that lactic acid, PGE2, or ATP plays a role in evoking the exercise pressor reflex proved controversial. The findings in humans resembled ours in decerebrate rats that individual blockade of the receptors to lactic acid, PGE2, and ATP had only small effects on the exercise pressor reflex provided that the muscles were freely perfused. This similarity between humans and rats prompted us to test the hypothesis that in rats with freely perfused muscles combined receptor blockade is required to attenuate the exercise pressor reflex. We first compared the reflex before and after injecting either PPADS (10 mg/kg), a P2X receptor antagonist, APETx2 (100 μg/kg), an activating acid-sensing ion channel 3 (ASIC) channel antagonist, or L161982 (2 μg/kg), an EP4 receptor antagonist, into the arterial supply of the hindlimb of decerebrated rats. We then examined the effects of combined blockade of P2X receptors, ASIC3 channels, and EP4 receptors on the exercise pressor reflex using the same doses, intra-arterial route, and time course of antagonist injections as those used for individual blockade. We found that neither PPADS (n = 5), APETx2 (n = 6), nor L161982 (n = 6) attenuated the reflex. In contrast, combined blockade of these receptors (n = 7) attenuated the peak (↓27%, P reflex. Combined blockade injected intravenously had no effect on the reflex. We conclude that combined blockade of P2X receptors, ASIC3 channels, and EP4 receptors on the endings of thin fiber muscle afferents is required to attenuate the exercise pressor reflex in rats with freely perfused hindlimbs. Copyright © 2015 the American Physiological Society.

  8. Development of an Assay Based on the Effects of PGBx on the Isolated Perfused Rat Heart and Rat Skeletal Muscle.

    Science.gov (United States)

    1980-09-01

    had no effect on discphe- nol induced alterations in spontaneous heart rate, but did appear to prevent the increase in coronary flow caused by...Phosphorylase a i -24 activity was also the same in each of the groups examined (Table 2-4). DISCUSSION The ability of PGBx to prevent 2,4-dinitrophenol-induced...euthyroid and hyperthyroid rats. Eur. J. Pharmac. 19, 12-17. Aronson, C. E. and Serlick, E. R. (1977a) Effects of chlorpromazine on the isolated

  9. Glucose metabolism of isolated perfused rat hemidiaphragms stimulated via the phrenic nerve

    International Nuclear Information System (INIS)

    Bassett, D.J.P.; Bowen-Kelly, E.; Bierkamper, G.

    1986-01-01

    Few investigations using indirect electrical stimulation of diaphragm muscles have measured metabolic pathways involved in energy production. In this study, hemidiaphragm (HD) glucose catabolism was determined while resting and during stimulation with trains of either five (T5) or fifteen (T15) 50 Hz bursts per second. Tissues were perfused and bathed in HEPES buffer pH 7.4 equilibrated with 100% O 2 , and containing 11mM [U- 14 C][5- 3 H] D-glucose. Resting glucose catabolism via the Emden-Meyerhof pathway was indicated by a 3 H 2 O production rate of 1.45 +/- 0.07 μmol/h/HD (+/- S.E.M., n = 3), of which 47% was recovered as 14 C lactate. Following an initial decline in peak isometric tension from 100 g within the first 30 min, T5 and T15 stimulation gave constant tensions of 48 and 22 g during the next 60 min, respectively. These tensions were associated with linear rates of 3 H 2 O production of 2.93 +/- 0.41 and 2.84 +/- 0.25 μmol/h/HD (+/- S.E.M., n = 3). Since T5 and T15 stimulation had no significant effect on lactate formation from either exogenous or endogenous sources, the observed increased glycolytic rate was assumed to be associated with enhanced mitochondrial oxidation of glucose carbons to CO 2 . Increased oxidative catabolism of glucose could therefore be correlated with the increased energy demands of a stimulated diaphragm

  10. Glucose metabolism of isolated perfused rat hemidiaphragms stimulated via the phrenic nerve

    Energy Technology Data Exchange (ETDEWEB)

    Bassett, D.J.P.; Bowen-Kelly, E.; Bierkamper, G.

    1986-03-01

    Few investigations using indirect electrical stimulation of diaphragm muscles have measured metabolic pathways involved in energy production. In this study, hemidiaphragm (HD) glucose catabolism was determined while resting and during stimulation with trains of either five (T5) or fifteen (T15) 50 Hz bursts per second. Tissues were perfused and bathed in HEPES buffer pH 7.4 equilibrated with 100% O/sub 2/, and containing 11mM (U-/sup 14/C)(5-/sup 3/H) D-glucose. Resting glucose catabolism via the Emden-Meyerhof pathway was indicated by a /sup 3/H/sub 2/O production rate of 1.45 +/- 0.07 ..mu..mol/h/HD (+/- S.E.M., n = 3), of which 47% was recovered as /sup 14/C lactate. Following an initial decline in peak isometric tension from 100 g within the first 30 min, T5 and T15 stimulation gave constant tensions of 48 and 22 g during the next 60 min, respectively. These tensions were associated with linear rates of /sup 3/H/sub 2/O production of 2.93 +/- 0.41 and 2.84 +/- 0.25 ..mu..mol/h/HD (+/- S.E.M., n = 3). Since T5 and T15 stimulation had no significant effect on lactate formation from either exogenous or endogenous sources, the observed increased glycolytic rate was assumed to be associated with enhanced mitochondrial oxidation of glucose carbons to CO/sub 2/. Increased oxidative catabolism of glucose could therefore be correlated with the increased energy demands of a stimulated diaphragm.

  11. Pomegranate Extract Enhances Endothelium-Dependent Coronary Relaxation in Isolated Perfused Hearts from Spontaneously Hypertensive Ovariectomized Rats

    Science.gov (United States)

    Delgado, Nathalie T. B.; Rouver, Wender do N.; Freitas-Lima, Leandro C.; de Paula, Tiago D.-C.; Duarte, Andressa; Silva, Josiane F.; Lemos, Virgínia S.; Santos, Alexandre M. C.; Mauad, Helder; Santos, Roger L.; Moysés, Margareth R.

    2017-01-01

    Decline in estrogen levels promotes endothelial dysfunction and, consequently, the most prevalent cardiovascular diseases in menopausal women. The use of natural therapies such as pomegranate can change these results. Pomegranate [Punica granatum L. (Punicaceae)] is widely used as a phytotherapeutic agent worldwide, including in Brazil. We hypothesized that treatment with pomegranate hydroalcoholic extract (PHE) would improve coronary vascular reactivity and cardiovascular parameters. At the beginning of treatment, spontaneously hypertensive female rats were divided into Sham and ovariectomized (OVX) groups, which received pomegranate extract (PHE) (250 mg/kg) or filtered water (V) for 30 days by gavage. Systolic blood pressure was measured by tail plethysmography. After euthanasia, the heart was removed and coronary vascular reactivity was assessed by Langendorff retrograde perfusion technique. A dose-response curve for bradykinin was performed, followed by L-NAME inhibition. The protein expression of p-eNOS Ser1177, p-eNOS Thr495, total eNOS, p-AKT Ser473, total AKT, SOD-2, and catalase was quantified by Western blotting. The detection of coronary superoxide was performed using the protocol of dihydroethidium (DHE) staining Plasma nitrite measurement was analyzed by Griess method. Systolic blood pressure increased in both Sham-V and OVX-V groups, whereas it was reduced after treatment in Sham-PHE and OVX-PHE groups. The baseline coronary perfusion pressure was reduced in the Sham-PHE group. The relaxation was significantly higher in the treated group, and L-NAME attenuated the relaxation in all groups. The treatment has not changed p-eNOS (Ser1177), total eNOS, p-AKT (Ser473) and total AKT in any groups. However, in Sham and OVX group the treatment reduced the p-eNOS (Thr495) and SOD-2. The ovariectomy promoted an increasing in the superoxide anion levels and the treatment was able to prevent this elevation and reducing oxidative stress. Moreover, the treatment

  12. 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

    Directory of Open Access Journals (Sweden)

    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

  13. 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

  14. 99mTc-glucarate kinetics differentiate normal, stunned, hibernating, and nonviable myocardium in a perfused rat heart model

    International Nuclear Information System (INIS)

    Okada, David R.; Liu, Zhonglin; Johnson, Gerald; Okada, Robert D.; Beju, Delia; Khaw, Ban An

    2010-01-01

    99m Tc-glucarate is an infarct-avid imaging agent. However, patients may have mixtures of normal, irreversibly injured, stunned, and hibernating myocardium. The purposes were to determine 99m Tc-glucarate uptake and clearance kinetics in these four conditions, and its ability to determine the extent of injury. Twenty-two perfused rat hearts were studied: controls (n = 5), stunned (n = 5; 20-min no-flow followed by 5-min reflow), hibernating (n = 6; 120-min low flow at 4 ml/min), and ischemic-reperfused (n = 6; 120-min no-flow followed by reflow). 99m Tc-glucarate was then infused. Tracer activity was monitored using a NaI scintillation detector and a multichannel analyzer. Creatine kinase, electron microscopy, and triphenyltetrazolium chloride determined viability. 99m Tc-glucarate 10-min myocardial uptake was significantly greater in ischemic-reperfused (2.50 ± 0.09) (cpm, SEM) than in control (1.74 ± 0.07), stunned (1.68 ± 0.11), and hibernating (1.59 ± 0.11) (p 99m Tc-glucarate 60-min myocardial uptake was significantly greater in ischemic-reperfused (7.60 ± 0.63) than in control (1.98 ± 0.15), stunned (1.79 ± 0.08), and hibernating (2.33 ± 0.15) (p 99m Tc-glucarate activity continually and progressively increased in irreversibly injured myocardium. 99m Tc-glucarate uptake was strongly correlated with myocardial necrosis as determined by three independent assessments of viability. There were minimal and similar 99m Tc-glucarate uptakes in control, stunned, and hibernating myocardium. (orig.)

  15. MRI in acute cerebral ischaemia: perfusion imaging with superparamagnetic iron oxide in a rat model

    International Nuclear Information System (INIS)

    Forsting, M.; Reith, W.; Doerfler, A.; Kummer, R. von; Hacke, W.; Sartor, K.

    1994-01-01

    An imaging technique capable of detecting ischaemic cerebral injury at an early stage could improve diagnosis in acute or transient cerebral ischaemia. We compared the ability of superparamagnetically contrast-enhanced MRI and conventional T2-weighted MRI to detect ischaemic injury early after unilateral occlusion of the middle cerebral artery in 12 male Wistar rats. Permanent vessel occlusion was achieved by a transvascular approach, which has the advantage of not requiring a craniectom. At 45-60 min after the procedure, the animals had conventional T2-weighted MRI before and after administration of a superparamagnetic contrast agent (iron oxide particles). Unenhanced images were normal in all animals. After administration of iron oxide particles, the presumed ischaemic area was clearly visible, as relatively increased signal, in all animals; this high signal area corresponded to the area of ischaemic brain infarction seen on histological studies. Our results suggest that superparamagnetic iron particles may significantly reduce the interval between an ischaemic insult and the appearance of parenchymal changes on MRI. (orig./UWA)

  16. Effects of the pesticide amitraz and its metabolite BTS 27271 on insulin and glucagon secretion from the perfused rat pancreas: involvement of alpha2D-adrenergic receptors.

    Science.gov (United States)

    Abu-Basha, E A; Yibchok-Anun, S; Hopper, D L; Hsu, W H

    1999-11-01

    The study purpose was to investigate the direct effect of amitraz, a formamidine insecticide/acaricide, and its active metabolite BTS 27271 on insulin and glucagon secretion from the perfused rat pancreas. Amitraz and BTS 27271 (0.01, 0.1, 1, and 10 micromol/L) inhibited insulin secretion in a concentration-dependent manner. Amitraz increased glucagon secretion at 10 micromol/L, whereas BTS 27271 increased glucagon secretion at 1 and 10 micromol/L. Amitraz- and BTS 27271-induced decreases in insulin secretion and increases in glucagon secretion were not abolished during the 10-minute washout period. During the arginine treatment, both amitraz and BTS 27271 groups (0.1, 1, and 10 micromol/L) had lower insulin secretion and higher glucagon secretion than the control group. Idazoxan, an alpha2A/2D-adrenergic receptor (AR) antagonist, prevented the inhibitory effect of amitraz on insulin secretion in a concentration-dependent manner, but prazosin, an alpha1- and alpha2B/2C-AR antagonist, failed to antagonize the effect of amitraz. These results demonstrate that (1) amitraz and BTS 27271 inhibit insulin and stimulate glucagon secretion from the perfused rat pancreas, (2) amitraz inhibits insulin secretion by activation of alpha2D-ARs, since rats have alpha2D- but not alpha2A-ARs, and (3) amitraz and BTS 27271 may have a high binding affinity to the alpha2D-ARs of pancreatic islets.

  17. Dorsal column sensory axons degenerate due to impaired microvascular perfusion after spinal cord injury in rats

    Science.gov (United States)

    Muradov, Johongir M.; Ewan, Eric E.; Hagg, Theo

    2013-01-01

    The mechanisms contributing to axon loss after spinal cord injury (SCI) are largely unknown but may involve microvascular loss as we have previously suggested. Here, we used a mild contusive injury (120 kdyn IH impactor) at T9 in rats focusing on ascending primary sensory dorsal column axons, anterogradely traced from the sciatic nerves. The injury caused a rapid and progressive loss of dorsal column microvasculature and oligodendrocytes at the injury site and penumbra and a ~70% loss of the sensory axons, by 24 hours. To model the microvascular loss, focal ischemia of the T9 dorsal columns was achieved via phototoxic activation of intravenously injected rose bengal. This caused an ~53% loss of sensory axons and an ~80% loss of dorsal column oligodendrocytes by 24 hours. Axon loss correlated with the extent and axial length of microvessel and oligodendrocyte loss along the dorsal column. To determine if oligodendrocyte loss contributes to axon loss, the glial toxin ethidium bromide (EB; 0.3 µg/µl) was microinjected into the T9 dorsal columns, and resulted in an ~88% loss of dorsal column oligodendrocytes and an ~56% loss of sensory axons after 72 hours. EB also caused an ~72% loss of microvessels. Lower concentrations of EB resulted in less axon, oligodendrocyte and microvessel loss, which were highly correlated (R2 = 0.81). These data suggest that focal spinal cord ischemia causes both oligodendrocyte and axon degeneration, which are perhaps linked. Importantly, they highlight the need of limiting the penumbral spread of ischemia and oligodendrocyte loss after SCI in order to protect axons. PMID:23978615

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

    Science.gov (United States)

    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.

  19. {sup 99m}Tc-glucarate kinetics differentiate normal, stunned, hibernating, and nonviable myocardium in a perfused rat heart model

    Energy Technology Data Exchange (ETDEWEB)

    Okada, David R. [University of Pennsylvania School of Medicine, Philadelphia, PA (United States); Liu, Zhonglin [University of Arizona School of Medicine, Tucson, AZ (United States); Johnson, Gerald; Okada, Robert D. [University of Oklahoma Health Sciences Center, Oklahoma, OK (United States); University of Tulsa, Tulsa, OK (United States); Beju, Delia [Oklahoma State University School of Medicine, Tulsa, OK (United States); Khaw, Ban An [Northeastern University, Boston, MA (United States)

    2010-10-15

    {sup 99m}Tc-glucarate is an infarct-avid imaging agent. However, patients may have mixtures of normal, irreversibly injured, stunned, and hibernating myocardium. The purposes were to determine {sup 99m}Tc-glucarate uptake and clearance kinetics in these four conditions, and its ability to determine the extent of injury. Twenty-two perfused rat hearts were studied: controls (n = 5), stunned (n = 5; 20-min no-flow followed by 5-min reflow), hibernating (n = 6; 120-min low flow at 4 ml/min), and ischemic-reperfused (n = 6; 120-min no-flow followed by reflow). {sup 99m}Tc-glucarate was then infused. Tracer activity was monitored using a NaI scintillation detector and a multichannel analyzer. Creatine kinase, electron microscopy, and triphenyltetrazolium chloride determined viability. {sup 99m}Tc-glucarate 10-min myocardial uptake was significantly greater in ischemic-reperfused (2.50 {+-} 0.09) (cpm, SEM) than in control (1.74 {+-} 0.07), stunned (1.68 {+-} 0.11), and hibernating (1.59 {+-} 0.11) (p < 0.05). Tracer retention curves for ischemic-reperfused were elevated at all time points as compared with the other groups. {sup 99m}Tc-glucarate 60-min myocardial uptake was significantly greater in ischemic-reperfused (7.60 {+-} 0.63) than in control (1.98 {+-} 0.15), stunned (1.79 {+-} 0.08), and hibernating (2.33 {+-} 0.15) (p < 0.05). The 60-min well-counted tracer activity ratio of ischemic-reperfused to control was 9:1 and corroborated the NaI detector results. Creatine kinase, triphenyltetrazolium chloride, and electron microscopy all demonstrated significantly greater injury in ischemic-reperfused compared to the other groups. An excellent correlation was observed between viability markers and tracer activity (r = 0.99 triphenyltetrazolium chloride; r = 0.90 creatine kinase). {sup 99m}Tc-glucarate activity continually and progressively increased in irreversibly injured myocardium. {sup 99m}Tc-glucarate uptake was strongly correlated with myocardial necrosis as

  20. The beneficial in vitro effects of lovastatin and chelerythrine on relaxatory response to acetylcholine in the perfused mesentric bed isolated from diabetic rats.

    Science.gov (United States)

    Fatehi-Hassanabad, Zahra; Imen-Shahidi, Mohsen; Fatehi, Mohammad; Farrokhfall, Khadijeh; Parsaeei, Heidar

    2006-03-27

    Diabetes mellitus is associated with an increased risk of cardiovascular disease. Endothelial dysfunction (i.e. decreased endothelium-dependent vasorelaxation) plays a key role in the pathogenesis of diabetic vascular disease. The present study was undertaken to determine whether diabetes induced by streptozotocin alters mesenteric responses to vasodilators and, if so, to study the acute in vitro effects of lovastatin and chelerythrine. Endothelial function was assessed in constantly perfused preparation removed from rats, 12 weeks after treatment with either saline or streptozotocin (45 mg/kg, intraperitoneally). In pre-contracted mesenteric beds (with 100 microM phenylephrine) removed from diabetic rats, the concentration response curve to acetylcholine, but not to sodium nitroprusside, was significantly reduced. Perfusion with lovastatin (10 microM for 20 min) or chelerythrine (1 microM for 20 min) significantly improved the acetylcholine-mediated relaxation in preparations removed from diabetic but not control rats. Pre-incubation of tissue with N(G)-nitro-L-argenine methyl ester hydrochloride (10 microM for 20 min) inhibited the beneficial effect of lovastatin but not chelerythrine. Pre-treatment of tissue with indomethacin (10 microM for 20 min) did not modify the effects of lovastatin or chelerythrine on acetylcholine responses. The present results demonstrate that endothelial dysfunction induced by diabetes (in a resistant vasculature, such as rat mesenteric bed) may be improved by an acute exposure to either lovastatin or chelerythrine. Furthermore, our results suggest that the beneficial effect of lovastatin is mediated via the nitric oxide pathway.

  1. 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

  2. Differential inhibitory response to telcagepant on αCGRP induced vasorelaxation and intracellular Ca(2+) levels in the perfused and non-perfused isolated rat middle cerebral artery

    DEFF Research Database (Denmark)

    Erdling, André; Sheykhzade, Majid; Edvinsson, Lars

    2017-01-01

    BACKGROUND: Calcitonin gene-related peptide (CGRP) is one of the most potent endogenous vasodilators identified to date. The present study elucidates the differential interaction of CGRP, its receptor and the effect of the CGRP-receptor antagonist telcagepant on intracellular Ca(2+) -levels...... and tension in rat middle cerebral arteries (MCA) by pressurized arteriography, FURA-2/wire myography and immunohistochemistry. METHODS: A pressurized arteriograph system was used to evaluate changes in MCA tension when subjected to CGRP and/or telcagepant. Intracellular calcium levels were evaluated using......, while abluminal telcagepant inhibited the relaxation (10(-6) M). Using the FURA-2 method in combination with wire myography we observed that αCGRP reduced intracellular calcium levels and in parallel the vascular tone. Telcagepant (10(-6) M) inhibited both vasorelaxation and drop in intracellular...

  3. 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

  4. TNFa-based isolated limb perfusion in the rat : development of a model and analysis of efficacy determining factors

    NARCIS (Netherlands)

    E.R. Manusama (Eric)

    1998-01-01

    textabstractIsolated limb perfusion (lLP) with high dose TNFa in combination with IFNr and melphalan in patients with melanoma in transit metastases confined to the limb has recently been reported to result in much higher complete tumor response rates than after the standard therapy of ILP with

  5. Isolated lung perfusion with gemcitabine for the treatment of pulmonary metastases : Experimental study in a rat model

    NARCIS (Netherlands)

    Putte, B.P. van

    2003-01-01

    Isolated lung perfusion is an experimental surgical technique for the treatment of pulmonary metastases in order to improve the current 5-year survival of approximately 40 % after surgical resection of manually palpable metastases. Several drugs have been tested in animals models and five phase I

  6. Delayed perfusion phenomenon in a rat stroke model at 1.5 T MR: An imaging sign parallel to spontaneous reperfusion and ischemic penumbra?

    Energy Technology Data Exchange (ETDEWEB)

    Chen Feng [Department of Radiology, University Hospitals, Catholic University of Leuven, Herestraat 49, B-3000 Leuven (Belgium); Department of Radiology, Zhong Da Hospital, Southeast University, 87 Ding Jia Qiao Road, Nanjing 210009, Jiangsu Province (China); Suzuki, Yasuhiro [Department of Molecular and Cellular Medicine, Faculty of Medicine, Catholic University of Leuven, Herestraat 49, B-3000 Leuven (Belgium); Department of Pharmacology, Hamamatsu University School of Medicine, 1-20-1 Handayama, 431-3192 Hamamatsu (Japan); Nagai, Nobuo [Department of Molecular and Cellular Medicine, Faculty of Medicine, Catholic University of Leuven, Herestraat 49, B-3000 Leuven (Belgium); Sun Xihe [Department of Radiology, University Hospitals, Catholic University of Leuven, Herestraat 49, B-3000 Leuven (Belgium); Department of Radiology, the Affiliated Hospital of Weifang Medical University, Weifang 261031, Shandong Province (China); Coudyzer, Walter [Department of Radiology, University Hospitals, Catholic University of Leuven, Herestraat 49, B-3000 Leuven (Belgium); Yu Jie [Department of Radiology, University Hospitals, Catholic University of Leuven, Herestraat 49, B-3000 Leuven (Belgium); Marchal, Guy [Department of Radiology, University Hospitals, Catholic University of Leuven, Herestraat 49, B-3000 Leuven (Belgium); Ni Yicheng [Department of Radiology, University Hospitals, Catholic University of Leuven, Herestraat 49, B-3000 Leuven (Belgium)]. E-mail: Yicheng.Ni@med.kuleuven.ac.be

    2007-01-15

    Introduction: Delayed perfusion (DP) sign at MR imaging was reported in stroke patients. We sought to experimentally elucidate its relation to spontaneous reperfusion and ischemic penumbra. Methods: Stroke was induced by photothrombotic occlusion of middle cerebral artery in eight rats and studied up to 72 h using a 1.5 T MR scanner with T2 weighted imaging (T2WI), diffusion weighted imaging (DWI), and dynamic susceptibility contrast-enhanced perfusion weighted imaging (DSC-PWI). Relative signal intensity (rSI), relative lesion volume (rLV), relative cerebral blood flow (rCBF), PWI{sub rLV}-DWI{sub rLV} mismatch (penumbra) and DP{sub rLV} were quantified and correlated with neurological deficit score (NDS), triphenyl tetrazolium chloride (TTC) staining, microangiography (MA) and histopathology. Results: The rSI and rLV characterized this stroke model on different MRI sequences and time points. DSC-PWI reproduced cortical DP in all rats, where rCBF evolved from 88.9% at 1 h through 64.9% at 6 h to 136.3% at 72 h. The PWI{sub rLV}-DWI{sub rLV} mismatch reached 10 {+-} 5.4% at 1 h, remained positive through 12 h and decreased to -3.3 {+-} 4.5% at 72 h. The incidence and rLV of the DP were well correlated with those of the penumbra (p < 0.01, r {sup 2} = 0.85 and p < 0.0001, r {sup 2} = 0.96, respectively). Shorter DP durations and more collateral arterioles occurred in rats without (n = 4) than with (n = 4) cortex involvement (p < 0.05). Rats without cortex involvement tended to earlier reperfusion and a lower NDS. Microscopy confirmed MRI, MA and TTC findings. Conclusions: In this rat stroke model, we reproduced clinically observed DP on DSC-PWI, confirmed spontaneous reperfusion, and identified the penumbra extending to 12 h post-ischemia, which appeared interrelated.

  7. Induction of chagasic-like arrhythmias in the isolated beating hearts of healthy rats perfused with Trypanosoma cruzi-conditioned medium

    Directory of Open Access Journals (Sweden)

    H. Rodriguez-Angulo

    2013-01-01

    Full Text Available Chagas' myocardiopathy, caused by the intracellular protozoan Trypanosoma cruzi, is characterized by microvascular alterations, heart failure and arrhythmias. Ischemia and arrythmogenesis have been attributed to proteins shed by the parasite, although this has not been fully demonstrated. The aim of the present investigation was to study the effect of substances shed by T. cruzi on ischemia/reperfusion-induced arrhythmias. We performed a triple ischemia-reperfusion (I/R protocol whereby the isolated beating rat hearts were perfused with either Vero-control or Vero T. cruzi-infected conditioned medium during the different stages of ischemia and subsequently reperfused with Tyrode's solution. ECG and heart rate were recorded during the entire experiment. We observed that triple I/R-induced bradycardia was associated with the generation of auricular-ventricular blockade during ischemia and non-sustained nodal and ventricular tachycardia during reperfusion. Interestingly, perfusion with Vero-infected medium produced a delay in the reperfusion-induced recovery of heart rate, increased the frequency of tachycardic events and induced ventricular fibrillation. These results suggest that the presence of parasite-shed substances in conditioned media enhances the arrhythmogenic effects that occur during the I/R protocol.

  8. Comparison of the gravimetric, phenol red, and 14C-PEG-3350 methods to determine water absorption in the rat single-pass intestinal perfusion model.

    Science.gov (United States)

    Sutton, S C; Rinaldi, M T; Vukovinsky, K E

    2001-01-01

    This study was undertaken to determine whether the gravimetric method provided an accurate measure of water flux correction and to compare the gravimetric method with methods that employ nonabsorbed markers (eg, phenol red and 14C-PEG-3350). Phenol red,14C-PEG-3350, and 4-[2-[[2-(6-amino-3-pyridinyl)-2-hydroxyethyl]amino]ethoxy]-, methyl ester, (R)-benzene acetic acid (Compound I) were co-perfused in situ through the jejunum of 9 anesthetized rats (single-pass intestinal perfusion [SPIP]). Water absorption was determined from the phenol red,14C-PEG-3350, and gravimetric methods. The absorption rate constant (ka) for Compound I was calculated. Both phenol red and 14C-PEG-3350 were appreciably absorbed, underestimating the extent of water flux in the SPIP model. The average +/- SD water flux microg/h/cm) for the 3 methods were 68.9 +/- 28.2 (gravimetric), 26.8 +/- 49.2 (phenol red), and 34.9 +/- 21.9 (14C-PEG-3350). The (average +/- SD) ka for Compound I (uncorrected for water flux) was 0.024 +/- 0.005 min(-1). For the corrected, gravimetric method, the average +/- SD was 0.031 +/- 0.001 min(-1). The gravimetric method for correcting water flux was as accurate as the 2 "nonabsorbed" marker methods.

  9. Comparison of semi-quantitative and quantitative dynamic contrast-enhanced MRI evaluations of vertebral marrow perfusion in a rat osteoporosis model.

    Science.gov (United States)

    Zhu, Jingqi; Xiong, Zuogang; Zhang, Jiulong; Qiu, Yuyou; Hua, Ting; Tang, Guangyu

    2017-11-14

    This study aims to investigate the technical feasibility of semi-quantitative and quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the assessment of longitudinal changes of marrow perfusion in a rat osteoporosis model, using bone mineral density (BMD) measured by micro-computed tomography (micro-CT) and histopathology as the gold standards. Fifty rats were randomly assigned to the control group (n=25) and ovariectomy (OVX) group whose bilateral ovaries were excised (n=25). Semi-quantitative and quantitative DCE-MRI, micro-CT, and histopathological examinations were performed on lumbar vertebrae at baseline and 3, 6, 9, and 12 weeks after operation. The differences between the two groups in terms of semi-quantitative DCE-MRI parameter (maximum enhancement, E max ), quantitative DCE-MRI parameters (volume transfer constant, K trans ; interstitial volume, V e ; and efflux rate constant, K ep ), micro-CT parameter (BMD), and histopathological parameter (microvessel density, MVD) were compared at each of the time points using an independent-sample t test. The differences in these parameters between baseline and other time points in each group were assessed via Bonferroni's multiple comparison test. A Pearson correlation analysis was applied to assess the relationships between DCE-MRI, micro-CT, and histopathological parameters. In the OVX group, the E max values decreased significantly compared with those of the control group at weeks 6 and 9 (p=0.003 and 0.004, respectively). The K trans values decreased significantly compared with those of the control group from week 3 (pquantitative DCE-MRI, the quantitative DCE-MRI parameter K trans is a more sensitive and accurate index for detecting early reduced perfusion in osteoporotic bone.

  10. Renal perfusion scintiscan

    Science.gov (United States)

    ... 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 ...

  11. Alterations of the Blood-Brain Barrier and Regional Perfusion in Tumor Development: MRI Insights from a Rat C6 Glioma Model.

    Science.gov (United States)

    Huhndorf, Monika; Moussavi, Amir; Kramann, Nadine; Will, Olga; Hattermann, Kirsten; Stadelmann, Christine; Jansen, Olav; Boretius, Susann

    2016-01-01

    Angiogenesis and anti-angiogenetic medications play an important role in progression and therapy of glioblastoma. In this context, in vivo characterization of the blood-brain-barrier and tumor vascularization may be important for individual prognosis and therapy optimization. We analyzed perfusion and capillary permeability of C6-gliomas in rats at different stages of tumor-growth by contrast enhanced MRI and dynamic susceptibility contrast (DSC) MRI at 7 Tesla. The analyses included maps of relative cerebral blood volume (CBV) and signal recovery derived from DSC data over a time period of up to 35 days after tumor cell injections. In all rats tumor progression was accompanied by temporal and spatial changes in CBV and capillary permeability. A leakage of the blood-brain barrier (slow contrast enhancement) was observed as soon as the tumor became detectable on T2-weighted images. Interestingly, areas of strong capillary permeability (fast signal enhancement) were predominantly localized in the center of the tumor. In contrast, the tumor rim was dominated by an increased CBV and showed the highest vessel density compared to the tumor center and the contralateral hemisphere as confirmed by histology. Substantial regional differences in the tumor highlight the importance of parameter maps in contrast or in addition to region-of-interest analyses. The data vividly illustrate how MRI including contrast-enhanced and DSC-MRI may contribute to a better understanding of tumor development.

  12. Properties of the luminal membrane of isolated perfused rat pancreatic ducts. Effect of cyclic AMP and blockers of chloride transport

    DEFF Research Database (Denmark)

    Novak, I; Greger, R

    1988-01-01

    - and interlobular ducts of rat pancreas was used. Responses of the epithelium to inhibitors and agonists were monitored by electrophysiological techniques. Addition of HCO-3/CO2 to the bath side of nonstimulated ducts depolarized the PD across the basolateral membrane (PDbl) by about 9 mV, as also observed...

  13. Lack of histological cerebellar changes in Wistar rats given pulegone for 28 days. Comparison of immersion and perfusion tissue fixation

    DEFF Research Database (Denmark)

    Mølck, Anne-Marie; Poulsen, Morten; Lauridsen, Søren Tindgard

    1998-01-01

    Pulegone was given orally by gavage to groups of 28 SPF Wistar rats at dosage levels of 0 or 160 mg/kg body weight per day for 28 days. Clinically treated animals showed slackness, depression, decreased food consumption, and body weight. The loss of body weight was accompanied by a marked decrease...

  14. Pyrrolidine dithiocarbamate administered during ex-vivo lung perfusion promotes rehabilitation of injured donor rat lungs obtained after prolonged warm ischemia.

    Directory of Open Access Journals (Sweden)

    Cyril Francioli

    Full Text Available Damaged lung grafts obtained after circulatory death (DCD lungs and warm ischemia may be at high risk of reperfusion injury after transplantation. Such lungs could be pharmacologically reconditioned using ex-vivo lung perfusion (EVLP. Since acute inflammation related to the activation of nuclear factor kappaB (NF-κB is instrumental in lung reperfusion injury, we hypothesized that DCD lungs might be treated during EVLP by pyrrolidine dithiocarbamate (PDTC, an inhibitor of NF-κB. Rat lungs exposed to 1h warm ischemia and 2 h cold ischemia were subjected to EVLP during 4h, in absence (CTRL group, N = 6 or in presence of PDTC (2.5g/L, PDTC group, N = 6. Static pulmonary compliance (SPC, peak airway pressure (PAWP, pulmonary vascular resistance (PVR, and oxygenation capacity were determined during EVLP. After EVLP, we measured the weight gain of the heart-lung block (edema, and the concentration of LDH (cell damage, proteins (permeability edema and of the cytokines IL-6, TNF-α and CINC-1 in bronchoalveolar lavage (BAL, and we evaluated NF-κB activation by the degree of phosphorylation and degradation of its inhibitor IκBα in lung tissue. In CTRL, we found significant NF-κB activation, lung edema, and a massive release of LDH, proteins and cytokines. SPC significantly decreased, PAWP and PVR increased, while oxygenation tended to decrease. Treatment with PDTC during EVLP inhibited NF-κB activation, did not influence LDH release, but markedly reduced lung edema and protein concentration in BAL, suppressed TNFα and IL-6 release, and abrogated the changes in SPC, PAWP and PVR, with unchanged oxygenation. In conclusion, suppression of innate immune activation during EVLP using the NF-κB inhibitor PDTC promotes significant improvement of damaged rat DCD lungs. Future studies will determine if such rehabilitated lungs are suitable for in vivo transplantation.

  15. 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

  16. Myocardial uptake of cocaine and effects of cocaine on myocardial substrate utilization and perfusion in hypertensive rats

    Energy Technology Data Exchange (ETDEWEB)

    Som, P.; Wang, G.J. [Brookhaven National Lab., Upton, NY (United States); Oster, Z.H. [State Univ. of New York, Stony Brook, NY (United States); Knapp, F.F. Jr. [Oak Ridge National Lab., TN (United States); Yonekura, Y. [Kyoto Univ. (Japan). Faculty of Medicine; Fujibayashi, Y. [Kyoto Univ. (Japan). Hospital; Yamamoto, K. [Fukui Univ. (Japan). Medical School; Kubota, K. [Tohoku Univ., Sendai (Japan)

    1992-12-31

    Cocaine abuse is a problem causing world-wide concern and the number of deaths following cocaine use is increasing. Cardiovascular complications following cocaine include severe tachyarrythmias, pulmonary edema, myocardial infarction, and acute renal failure, which are major problems confronting emergency facilities. While the studies of cocaine effects on the brain have been given the most attention, it is clear that the effects of cocaine on the cardiovascular system are of great importance, given the increasing number of reports on sudden death and myocardial infarctions in young adults related to cocaine use. The precise mechanisms of cardiotoxic actions of cocaine are unclear. We investigated the whole-body distribution of C-14-labeled cocaine to determine the cocaine-binding sites, including blocking experiments to determine the nature of regional binding sites, and differential response of the normal vs. diseased heart (hypertensive cardiomyopathy) in an animal model to mimic a potentially high risk population. We investigated the acute effects of cocaine on myocardial metabolism using two myocardial energy substrate analogs, fatty acid and glucose with comparison with regional perfusion.

  17. Myocardial uptake of cocaine and effects of cocaine on myocardial substrate utilization and perfusion in hypertensive rats

    Energy Technology Data Exchange (ETDEWEB)

    Som, P.; Wang, G.J. (Brookhaven National Lab., Upton, NY (United States)); Oster, Z.H. (State Univ. of New York, Stony Brook, NY (United States)); Knapp, F.F. Jr. (Oak Ridge National Lab., TN (United States)); Yonekura, Y. (Kyoto Univ. (Japan). Faculty of Medicine); Fujibayashi, Y. (Kyoto Univ. (Japan). Hospital); Yamamoto, K. (Fukui Univ. (Japan). Medical School); Kubota, K. (Tohoku Univ., Sendai

    1992-01-01

    Cocaine abuse is a problem causing world-wide concern and the number of deaths following cocaine use is increasing. Cardiovascular complications following cocaine include severe tachyarrythmias, pulmonary edema, myocardial infarction, and acute renal failure, which are major problems confronting emergency facilities. While the studies of cocaine effects on the brain have been given the most attention, it is clear that the effects of cocaine on the cardiovascular system are of great importance, given the increasing number of reports on sudden death and myocardial infarctions in young adults related to cocaine use. The precise mechanisms of cardiotoxic actions of cocaine are unclear. We investigated the whole-body distribution of C-14-labeled cocaine to determine the cocaine-binding sites, including blocking experiments to determine the nature of regional binding sites, and differential response of the normal vs. diseased heart (hypertensive cardiomyopathy) in an animal model to mimic a potentially high risk population. We investigated the acute effects of cocaine on myocardial metabolism using two myocardial energy substrate analogs, fatty acid and glucose with comparison with regional perfusion.

  18. Characteristics of diffusion and perfusion-weighted MRI in different cranial infarction areas of acute stroke in a rat model

    International Nuclear Information System (INIS)

    Zhao Jungong; Li Minghua; Cheng Yingsheng; Fang Chun; Qiao Ruihua

    2005-01-01

    Objective: To investigate the Characterization of DWI and PWI during cranio-ischemia in assessment of reversible ischemic penumbra in rats. Methods: All 22 rats were randomly divided into 2 groups, group A (n=17). The left middle cerebral arteries were occluded with filaments for 1.5 hours (n=3), 3 hours (n=6), 6 hours (n=3), 9 hours (n=5) respectively; group B (n=5) with sham operation was set up for control study. The DWI and PWI were performed when rats experienced neurologic deficits. Their apparent diffusion coefficient (ADC), relative negative enhancement integral (rNEI), relative time to minimum (rTTM), relative max slope of increase (rMSI), relative max slope of decrease (rMSD) were measured at areas of ischemic core, ischemic margin, and cortex. Two rats of each sub-group were performed with TTC staining, histopathology, immunocheministry and laser scanning confocal microscope (LSCM) for control study. Results: ADC values significantly decreased in the ischemic core (0.29 x 10 -3 mm 2 /s) compared with ischemic margin (0.51 x 10 -3 mm 2 /s) and cortex (0.59 x 10 -3 mm 2 /s) (P -3 mm 2 /s for ADC, 70% for rNEI and 120% for rTTM would be the optimal standard suggesting the mild cranial tissue damage or with reversible tissue damage. Conclusions: Semi-quantitative parameters based on DWI and PWI of acute cranial ischemia can provide us new modalities for distinguishing and confirming the existences and extent of ischemic area. (authors)

  19. 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

  20. 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

  1. Comparative effect of lidocaine and bupivacaine on glucose uptake and lactate production in the perfused working rat heart

    International Nuclear Information System (INIS)

    Cronau, L.H. Jr.; Merin, R.G.; Aboulish, E.; Steenberg, M.L.; Maljorda, A.

    1986-01-01

    It has been suggested that at equivalent therapeutic concentrations, lidocaine and bupivacaine may have different cardiotoxic potency. In the isolated working rat heart preparation, the effect of a range of lidocaine and bupivacaine concentrations on glucose uptake and lactate production (LP) were observed. Insulin was added, 10 μ/L, to Ringer's solution containing 3 H-labeled glucose to measure the glycolytic flux (GF). The effect of the local anesthetics on LP at the indicated concentrations were similar. Lidocaine appears to depress the glycolytic flux from exogenous glucose to a lesser degree. Bupivacaine, 10 mg/L, depresses VO 2 to a greater degree than does lidocaine, 40 mg/L

  2. Vascular, but not luminal, activation of FFAR1 (GPR40) stimulates GLP-1 secretion from isolated perfused rat small intestine

    DEFF Research Database (Denmark)

    Christensen, Louise Wulff; Kuhre, Rune Ehrenreich; Janus, Charlotte

    2015-01-01

    -protein-cou- pled receptor, FFAR1 (previously GPR40), expressed on L cells and activated by long-chain fatty acids (LCFAs) is a potential target. A link between FFAR1 activation and GLP-1 secretion has been demonstrated in cellular models and small-molecule FFAR1 agonists have been developed. In this study, we exam......- ined the effect of FFAR1 activation on GLP-1 secretion using isolated, per- fused small intestines from rats, a physiologically relevant model allowing distinction between direct and indirect effects of FFAR1 activation. The endogenous FFAR1 ligand, linoleic acid (LA), and four synthetic FFAR1 ago...

  3. 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

  4. Comparative effect of lidocaine and bupivacaine on glucose uptake and lactate production in the perfused working rat heart

    Energy Technology Data Exchange (ETDEWEB)

    Cronau, L.H. Jr.; Merin, R.G.; Aboulish, E.; Steenberg, M.L.; Maljorda, A.

    1986-03-01

    It has been suggested that at equivalent therapeutic concentrations, lidocaine and bupivacaine may have different cardiotoxic potency. In the isolated working rat heart preparation, the effect of a range of lidocaine and bupivacaine concentrations on glucose uptake and lactate production (LP) were observed. Insulin was added, 10 ..mu../L, to Ringer's solution containing /sup 3/H-labeled glucose to measure the glycolytic flux (GF). The effect of the local anesthetics on LP at the indicated concentrations were similar. Lidocaine appears to depress the glycolytic flux from exogenous glucose to a lesser degree. Bupivacaine, 10 mg/L, depresses VO/sub 2/ to a greater degree than does lidocaine, 40 mg/L.

  5. 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

  6. A new model for portal protein profile analysis in course of ileal intraluminal bile acid infusion using an in situ perfused rat intestine.

    Science.gov (United States)

    Montagnani, Marco; Tsivian, Matvey; Neri, Flavia; Zvi, Ido Ben; Mantovani, Irina; Nanni, Paolo; Benevento, Marco; Simoni, Patrizia; Marangoni, Antonella; Pariali, Milena; Fato, Romana; Bergamini, Christian; Leoni, Serena; Azzaroli, Francesco; Mazzella, Giuseppe; Nardo, Bruno; Roda, Enrico; Aldini, Rita

    2011-07-01

    Due to the importance of intestinal transport in pharmacological studies and the emerging role of intestinal signaling activity in the gut-liver axis, we have developed a new method to investigate intestinal transport and liver signaling using cell and serum free mesenteric perfusion system in the rat. The method regarding bile acid active absorption was validated, then, the portal venous content was examined for fibroblast growth factor 15(FGF15), a putative signaling protein produced by the ileal enterocytes following bile acid absorption. After isolation and cannulation of the relevant vessels (abdominal aorta and portal vein), the abdominal aorta and the terminal ileum were infused with respectively Krebs-Ringer solution and tauroursodeoxycholate (TUDCA) and the absorption was assessed by its recovery in the portal vein. After immunoblot, liquid chromatography and mass spectrometry analysis were performed both on gel bands digestion products and on portal outflow samples in order to evaluate if negligible amounts of FGF15 were present in the portal circulation. TUDCA absorption was efficient, intestinal morphology and oxygen consumption were normal. Despite accurate analysis, we could not find FGF15. Our method proved to be reliable for studying the active bile acid absorption. It is also suitable to identify molecules produced by enterocytes and transferred to the portal circulation in response to absorption of different substances such as nutrients or drugs. Since FGF15 was not recovered we suggest the possibilities that this protein is produced in very little amounts, poorly transferred outside the cell, or that it is extremely unstable and rapidly degraded.

  7. 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

  8. Rotavirus Viremia and Extraintestinal Viral Infection in the Neonatal Rat Model

    Science.gov (United States)

    Crawford, Sue E.; Patel, Dinesh G.; Cheng, Elly; Berkova, Zuzana; Hyser, Joseph M.; Ciarlet, Max; Finegold, Milton J.; Conner, Margaret E.; Estes, Mary K.

    2006-01-01

    Rotaviruses infect mature, differentiated enterocytes of the small intestine and, by an unknown mechanism, escape the gastrointestinal tract and cause viremia. The neonatal rat model of rotavirus infection was used to determine the kinetics of viremia, spread, and pathology of rotavirus in extraintestinal organs. Five-day-old rat pups were inoculated intragastrically with an animal (RRV) or human (HAL1166) rotavirus or phosphate-buffered saline. Blood was collected from a subset of rat pups, and following perfusion to remove residual blood, organs were removed and homogenized to analyze rotavirus-specific antigen by enzyme-linked immunosorbent assay and infectious rotavirus by fluorescent focus assay or fixed in formalin for histology and immunohistochemistry. Viremia was detected following rotavirus infection with RRV and HAL1166. The RRV 50% antigenemia dose was 1.8 × 103 PFU, and the 50% diarrhea dose was 7.7 × 105 PFU, indicating that infection and viremia occurred in the absence of diarrhea and that detecting rotavirus antigen in the blood was a more sensitive measure of infection than diarrhea. Rotavirus antigens and infectious virus were detected in multiple organs (stomach, intestines, liver, lungs, spleen, kidneys, pancreas, thymus, and bladder). Histopathological changes due to rotavirus infection included acute inflammation of the portal tract and bile duct, microsteatosis, necrosis, and inflammatory cell infiltrates in the parenchymas of the liver and lungs. Colocalization of structural and nonstructural proteins with histopathology in the liver and lungs indicated that the histological changes observed were due to rotavirus infection and replication. Replicating rotavirus was also detected in macrophages in the lungs and blood vessels, indicating a possible mechanism of rotavirus dissemination. Extraintestinal infectious rotavirus, but not diarrhea, was observed in the presence of passively or actively acquired rotavirus-specific antibody. These

  9. Effects of special brain area regional cerebral blood flow abnormal perfusion on learning and memory function and its molecular mechanism in rats

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    s To study the effect of special brain area regional cerebral blood flow (rCBF) abnormal perfusion on learning and memory function and its molecular mechanism,64 adult male healthy Spragne-Dawley (SD) rats were randomly divided into two groups,the false operation group (control group) and the operation group (model group).After surgical operation,the operation group undertook bilateral common carotid artery permanent ligation,while the other group did not.Learning and memory function were measured by Y-maze at 4 h,8 h,24 h and 3 d after surgical operation,respectively.The rCBF of the right frontal lobe and hippocampus was also detected by the PerifluxPF model laser Doppler flowmetry,and the expressions of c-fos or c-jun or Bcl-2 and Bax were also measured by immune histochemistry S-P method accordingly.Results showed that the rCBF of the right frontal lobe and hippocampus in the operation group was significantly lower than that in the false operation group (P < 0.05).The learning indexes,error number (EN),day of reach standard and total reaction time (TRT) in the operation group,were significantly higher than that in the false operation group (P< 0.05).However,the initiative evasion rate in the operation group was significantly lower than that in the false operation group.The study also found that the rCBF was relatively more,the indexes (EN,the day of reach standard and TRT) relatively fewer,but the initiative evasion rate and the memory keeping rate were relatively more.The positive expression and the average absorbency of Fos and Jun in the operation group were significantly higher than that in the false operation group (P< 0.05).Furthermore,Bax and Bcl-2 positive cells were all increased over time in the operation group,and the expression ratio of Bax/Bcl-2 in the operation group was significantly higher than that in the false operation group (P<0.01).In conclusion,rCBF decrease can impair the learning and memory function in rats,which may be related to

  10. Pharmacologically increasing collateral perfusion during acute stroke using a carboxyhemoglobin gas transfer agent (Sanguinate™) in spontaneously hypertensive rats.

    Science.gov (United States)

    Cipolla, Marilyn J; Linfante, Italo; Abuchowski, Abe; Jubin, Ronald; Chan, Siu-Lung

    2018-05-01

    Similar to patients with chronic hypertension, spontaneously hypertensive rats (SHR) develop fast core progression during middle cerebral artery occlusion (MCAO) resulting in large final infarct volumes. We investigated the effect of Sanguinate™ (SG), a PEGylated carboxyhemoglobin (COHb) gas transfer agent, on changes in collateral and reperfusion cerebral blood flow and brain injury in SHR during 2 h of MCAO. SG (8 mL/kg) or vehicle ( n = 6-8/group) was infused i.v. after 30 or 90 min of ischemia with 2 h reperfusion. Multi-site laser Doppler probes simultaneously measured changes in core MCA and collateral flow during ischemia and reperfusion using a validated method. Brain injury was measured using TTC. Animals were anesthetized with choral hydrate. Collateral flow changed little in vehicle-treated SHR during ischemia (-8 ± 9% vs. prior to infusion) whereas flow increased in SG-treated animals (29 ± 10%; p collateral flow in SHR during MCAO is consistent with small penumbra and large infarction. The ability to increase collateral flow in SHR with SG suggests that this compound may be useful as an adjunct to endovascular therapy and extend the time window for treatment.

  11. Beneficial effects of hyperosmotic perfusion in the myocardium after ischemia/reperfusion injury in isolated rat hearts Efeitos benéficos da perfusão hiperosmótica no miocárdio após lesão isquemia/reperfusão em corações isolados de ratos

    Directory of Open Access Journals (Sweden)

    Yong Cao

    2013-03-01

    Full Text Available OBJECTIVE: A simple method to reduce the ischemia/reperfusion injury that can accompany cardiac surgery would have great clinical value. This study was to investigate the effect of hyperosmotic perfusion on ischemia/reperfusion injury in isolated perfused rat hearts. METHOD: Forty male Sprague-Dawley rats were randomly divided either to have their isolated hearts perfused with normal osmotic buffer or buffer made hyperosmotic by addition of glucose. Hearts were then subjected to 30 min ischemia followed by 30 min reperfusion. Coronary flow, time to ischemic arrest, reperfusion arrhythmia, and ventricular function were recorded. Creatine phosphokinase leakage into the coronary artery, and myocardial content and activity of superoxide dismutase and catalase were also examined. RESULTS: Rat hearts with hyperosmotic perfusion showed higher coronary flow, a prolonged time to ischemic arrest (10.60 vs. 5.63 min, POBJETIVO: Um método simples para reduzir a lesão de isquemia/reperfusão que pode acompanhar a cirurgia cardíaca teria grande valor clínico. O objetivo deste estudo foi investigar o efeito da perfusão hiperosmótica na isquemia/reperfusão em corações isolados de ratos perfundidos. MÉTODOS: Quarenta ratos machos Sprague-Dawley foram divididos aleatoriamente e tiveram os seus corações isolados perfundidos com tampão osmótico normal ou tampão hiperosmótico com a adição de glucose. Os corações foram então submetidos a 30 minutos de isquemia, seguida de 30 min de reperfusão. O fluxo coronariano, tempo de parada isquêmica, arritmia de reperfusão e da função ventricular foram registrados. Vazamento creatinofosfoquinase na artéria coronária, o miocárdio e atividade de superóxido dismutase e catalase foram também examinados. RESULTADOS: Crações de ratos com perfusão hiperosmótica apresentaram maior fluxo coronariano, tempo prolongado de parada isquêmica (10,60 vs. 5,63 min, P<0,005, menor pontuação de reperfus

  12. 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.

  13. Increased perfusion pressure enhances the expression of endothelin (ETB) and angiotensin II (AT1, AT2) receptors in rat mesenteric artery smooth muscle cells

    DEFF Research Database (Denmark)

    Lindstedt, Isak; Xu, Cang-Bao; Zhang, Yaping

    2009-01-01

    and luminally perfused in a perfusion chamber. After either exposure to no ("organ culture" (0 mmHg)), normal (85/75 mmHg) or high pressure (160/150 mmHg) at constant flow for 1-17 h, the vessel segments were snap frozen and real-time polymerase chain reaction was performed to quantify the ET- and AT-receptor m...

  14. 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)

  15. Modelo experimental de perfusão pulmonar ex vivo em ratos: avaliação de desempenho de pulmões submetidos à administração de prostaciclina inalada versus parenteral An experimental rat model of ex vivo lung perfusion for the assessment of lungs after prostacyclin administration: inhaled versus parenteral routes

    Directory of Open Access Journals (Sweden)

    Paulo Francisco Guerreiro Cardoso

    2011-10-01

    Full Text Available OBJETIVO: Apresentar um modelo experimental de administração de prostaglandina I2 (PGI2 por via inalatória vs. parenteral e avaliar o desempenho funcional dos pulmões em um sistema de perfusão pulmonar ex vivo. MÉTODOS: Quarenta ratos Wistar foram anestesiados, ventilados, submetidos a laparotomia com ressecção do esterno e anticoagulados. O tronco da artéria pulmonar foi canulado. Todos os animais foram submetidos a ventilação mecânica. Os animais foram randomizados em quatro grupos (10 ratos/grupo: salina nebulizada (SN; salina parenteral (SP; PGI2 nebulizada (PGI2N; e PGI2 parenteral (PGI2P. A dose de PGI2 nos grupos PGI2N e PGI2P foi de 20 e 10 µg/kg, respectivamente. Os blocos cardiopulmonares foram submetidos in situ a perfusão anterógrada com solução de baixo potássio e dextrana a 4ºC via artéria pulmonar, extraídos em bloco e armazenados a 4ºC por 6 h. Os blocos foram ventilados e perfundidos em um sistema ex vivo por 50 min, sendo obtidas medidas de mecânica ventilatória, hemodinâmica e trocas gasosas. RESULTADOS: Houve redução da pressão arterial pulmonar média após a nebulização em todos os grupos (p OBJECTIVE:To present a model of prostaglandin I2 (PGI2 administration (inhaled vs. parenteral and to assess the functional performance of the lungs in an ex vivo lung perfusion system. METHODS: Forty Wistar rats were anesthetized and placed on mechanical ventilation followed by median sterno-laparotomy and anticoagulation. The main pulmonary artery was cannulated. All animals were maintained on mechanical ventilation and were randomized into four groups (10 rats/group: inhaled saline (IS; parenteral saline (PS; inhaled PGI2 (IPGI2; and parenteral PGI2 (PPGI2. The dose of PGI2 used in the IPGI2 and PPGI2 groups was 20 and 10 µg/kg, respectively. The heart-lung blocks were submitted to antegrade perfusion with a low potassium and dextran solution via the pulmonary artery, followed by en bloc extraction and

  16. 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.

  17. Histamine combined with melphalan in isolated limb perfusion for the treatment of locally advanced soft tissue sarcomas: preclinical studies in rats Histamina combinada ao melfalano na perfusão de membro isolado para o tratamento de sarcomas de partes moles localmente avançado: estudos pré-clínicos em ratos

    Directory of Open Access Journals (Sweden)

    Flavia Brunstein

    2005-08-01

    Full Text Available PURPOSE: To evaluate the potential benefit of histamine combined with melphalan in the isolated limb perfusion (ILP as an alternative to TNF-alfa and melphalan combination, for the treatment of irressectable soft tissue sarcomas of the limbs in Brown Norway (BN rats. METHODS: 20 BN rats had small fragments of syngeneic BN-175 fibosarcoma inserted on the right hind limb. In 7-10 days the tumor reached a median diameter of 12-15 mm and they were randomly divided in four groups (sham, melphalan, histamine and escalating doses of histamine combined to melphalan being submitted to experimental ILP for 30 minutes. Tumors were measured daily with a caliper and the volume was calculated. RESULTS: Response curves showed a significant effect of the combination of histamine 200 mg/mL with melphalan, with 66% overall response, including 33% complete responses (pOBJETIVO: Avaliar o potencial benéfico da histamina combinada ao melfalano, na perfusão de membro isolado (PMI, como alternativa à combinação TNF-alfa mais melfalano, no tratamento de sarcomas de partes moles irressecaveis em extremidades, em ratos de linhagem Brown Norway (BN. MÉTODOS: 20 ratos BN foram submetidos a implantação de fragmentos de fibrosarcoma singênico BN-175 na pata traseira direita. Em cerca de 7-10 dias o tumor atingiu um diâmetro médio de 12-15 mm e foram aleatóriamente divididos em quatro grupos (controle, melfalano, histamina em doses progessivas combinada ao melfalano e histamina sendo submetidos a PMI experimental por 30 minutos. Os tumores foram então medidos diariamente com o uso de paquímetro e o volume tumoral calculado. RESULTADOS: As curvas de resposta mostram um efeito significativo da combinação de Histamina na concentração de 200 mg/mL ao melfalano, com 66% de resposta global incluindo 33% de respostas completas (p < 0.01. Não houve efeitos colaterais sistêmicos e localmente apenas edema leve e transitório nos animais tratados com histamine

  18. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. 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.

  1. 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:

  2. 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)

  3. 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

  4. A Review of Liver Perfusion Method in Toxicology Studies

    Directory of Open Access Journals (Sweden)

    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

  5. 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.''

  6. Modelo experimental de perfusão pulmonar ex vivo em ratos: avaliação histopatológica e de apoptose celular em pulmões preservados com solução de baixo potássio dextrana vs. solução histidina-triptofano-cetoglutarato An experimental rat model of ex vivo lung perfusion for the assessment of lungs regarding histopathological findings and apoptosis: low-potassium dextran vs. histidine-tryptophan-ketoglutarate

    Directory of Open Access Journals (Sweden)

    Edson Azevedo Simões

    2012-08-01

    Full Text Available OBJETIVO: Comparar os achados histopatológicos e de apoptose em pulmões de ratos preservados em soluções low-potassium dextran (LPD, baixo potássio dextrana, histidine-tryptophan-ketoglutarate (HTK, histidina-triptofano-cetoglutarato ou salina normal (SN em 6 h e 12 h de isquemia pela utilização de um modelo experimental de perfusão pulmonar ex vivo. MÉTODOS: Sessenta ratos Wistar foram anestesiados, randomizados e submetidos à perfusão anterógrada pela artéria pulmonar com uma das soluções preservadoras. Após a extração, os blocos cardiopulmonares foram preservados por 6 ou 12 h a 4ºC, sendo então reperfundidos com sangue homólogo em um sistema de perfusão ex vivo durante 60 min. Ao final da reperfusão, fragmentos do lobo médio foram extraídos e processados para histopatologia, sendo avaliados os seguintes parâmetros: congestão, edema alveolar, hemorragia alveolar, hemorragia, infiltrado inflamatório e infiltrado intersticial. O grau de apoptose foi avaliado pelo método TdT-mediated dUTP nick end labeling. RESULTADOS: A histopatologia demonstrou que todos os pulmões preservados com SN apresentaram edema alveolar após 12 h de isquemia. Não houve diferenças em relação ao grau de apoptose nos grupos estudados. CONCLUSÕES: No presente estudo, os achados histopatológicos e de apoptose foram semelhantes com o uso das soluções LPD e HTK, enquanto a presença de edema foi significativamente maior com o uso de SN.OBJECTIVE: To compare histopathological findings and the degree of apoptosis among rat lungs preserved with low-potassium dextran (LPD solution, histidine-tryptophan-ketoglutarate (HTK solution, or normal saline (NS at two ischemia periods (6 h and 12 h using an experimental rat model of ex vivo lung perfusion. METHODS: Sixty Wistar rats were anesthetized, randomized, and submitted to antegrade perfusion via pulmonary artery with one of the preservation solutions. Following en bloc extraction, the heart

  7. How Does the Ca2+-paradox Injury Induce Contracture in the Heart?—A Combined Study of the Intracellular Ca2+ Dynamics and Cell Structures in Perfused Rat Hearts—

    International Nuclear Information System (INIS)

    Mani, Hiroki; Tanaka, Hideo; Adachi, Tetsuya; Ikegawa, Masaya; Dai, Ping; Fujita, Naohisa; Takamatsu, Tetsuro

    2015-01-01

    The calcium (Ca 2+ )-paradox injury of the heart, induced by restoration of extracellular Ca 2+ after its short-term depletion, is known to provoke cardiomyocyte contracture. However, undetermined is how the Ca 2+ -paradox provokes such a distinctive presentation of myocytes in the heart. To address this, we imaged sequential intracellular Ca 2+ dynamics and concomitant structures of the subepicardial ventricular myocytes in fluo3-loaded, Langendorff-perfused rat hearts produced by the Ca 2+ paradox. Under rapid-scanning confocal microscopy, repletion of Ca 2+ following its depletion produced high-frequency Ca 2+ waves in individual myocytes with asynchronous localized contractions, resulting in contracture within 10 min. Such alterations of myocytes were attenuated by 5-mM NiCl 2 , but not by verapamil, SEA0400, or combination of ryanodine and thapsigargin, indicating a contribution of non-specific transmembrane Ca 2+ influx in the injury. However, saponin-induced membrane permeabilization of Ca 2+ showed no apparent contracture despite the emergence of high-frequency Ca 2+ waves, indicating an essential role of myocyte-myocyte and myocyte-extracellular matrix (ECM) mechanical connections in the Ca 2+ paradox. In immunohistochemistry Ca 2+ depletion produced separation of the intercalated disc that expresses cadherin and dissipation of β-dystroglycan located along the sarcolemma. Taken together, along with the trans-sarcolemmal Ca 2+ influx, disruption of cell-cell and cell-ECM connections is essential for contracture in the Ca 2+ -paradox injury

  8. An axial distribution of seeding, proliferation, and osteogenic differentiation of MC3T3-E1 cells and rat bone marrow-derived mesenchymal stem cells across a 3D Thai silk fibroin/gelatin/hydroxyapatite scaffold in a perfusion bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Sinlapabodin, Salita; Amornsudthiwat, Phakdee; Damrongsakkul, Siriporn; Kanokpanont, Sorada, E-mail: sorada.k@chula.ac.th

    2016-01-01

    In cell culture, a perfusion bioreactor provides effective transportation of nutrients, oxygen, and waste removal to and from the core of the scaffold. In addition, it provides mechanical stimuli for enhancing osteogenic differentiation. In this study, we used an axial distribution of cell numbers, alkaline phosphatase (ALP) enzyme activity, and calcium content across 4 cross-sections of 10 mm thick scaffold, made of Thai silk fibroin (SF)/gelatin (G)/hydroxyapatite (HA), as a tool to evaluate the suitable perfusion flow rate. These evaluations cover all cellular developmental phases starting from seeding, to proliferation, and later osteogenic differentiation. Mouse pre-osteoblastic MC3T3-E1 cell lines were used as a cell model during seeding and proliferation. The bioreactor seeded scaffold provided more uniform cell distribution across the scaffold compared to centrifugal and agitation seeding, while the overall number of adhered cells from bioreactor seeding was slightly lower than agitation seeding. The dynamic culture using 1 ml/min perfusion flow rate (initial shear stress of 0.1 dyn/cm{sup 2}) enabled statistically higher MC3T3-E1 proliferation, ALP activity, and calcium deposition than those observed in the static-culturing condition. However, the perfusion flow rate of 1 ml/min seemed not to be enough for enhancing ALP expression across all sections of the scaffold. Rat bone marrow derived stromal cells (rMSC) were used in the detachment test and osteogenic differentiation. It was found that perfusion flow rate of 5 ml/min caused statistically higher cell detachment than that of 1 and 3 ml/min. The perfusion flow rate of 3 ml/min gave the highest rMSC osteogenic differentiation on a SF/G/HA scaffold than other flow rates, as observed from the significantly highest number of ALP enzyme activity and the calcium content without any significant cell growth. In addition, all of these parameters were evenly distributed across all scaffold sections. - Highlights

  9. Development of an Extracorporeal Perfusion Device for Small Animal Free Flaps.

    Directory of Open Access Journals (Sweden)

    Andreas M Fichter

    Full Text Available Extracorporeal perfusion (ECP might prolong the vital storage capabilities of composite free flaps, potentially opening a wide range of clinical applications. Aim of the study was the development a validated low-cost extracorporeal perfusion model for further research in small animal free flaps.After establishing optimal perfusion settings, a specially designed extracorporeal perfusion system was evaluated during 8-hour perfusion of rat epigastric flaps followed by microvascular free flap transfer. Controls comprised sham-operation, ischemia and in vivo perfusion. Flaps and perfusate (diluted blood were closely monitored by blood gas analysis, combined laser Doppler flowmetry and remission spectroscopy and Indocyanine-Green angiography. Evaluations were complemented by assessment of necrotic area and light microscopy at day 7.ECP was established and maintained for 8 hours with constant potassium and pH levels. Subsequent flap transfer was successful. Notably, the rate of necrosis of extracorporeally perfused flaps (27% was even lower than after in vivo perfusion (49%, although not statistically significant (P = 0,083. After sham-operation, only 6% of the total flap area became necrotic, while 8-hour ischemia led to total flap loss (98%. Angiographic and histological findings confirmed these observations.Vital storage capabilities of microvascular flaps can be prolonged by temporary ECP. Our study provides important insights on the pathophysiological processes during extracorporeal tissue perfusion and provides a validated small animal perfusion model for further studies.

  10. 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

  11. 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

  12. Extremity perfusion for sarcoma

    NARCIS (Netherlands)

    Hoekstra, Harald Joan

    2008-01-01

    For more than 50 years, the technique of extremity perfusion has been explored in the limb salvage treatment of local, recurrent, and multifocal sarcomas. The "discovery" of tumor necrosis factor-or. in combination with melphalan was a real breakthrough in the treatment of primarily irresectable

  13. Isolated limb perfusion.

    Science.gov (United States)

    Gillespie, Rosalyn; Chantier, Nariane

    1994-12-08

    Growing concern over the rising incidence of malignant melanoma has brought about a need for information on this disorder and the treatment available. Isolated limb perfusion is a relatively new technique used in only a few hospitals. An increased knowledge base will lead to a better understanding of the nursing care required and to a more in-depth care plan.

  14. High fat diet-induced glucose intolerance impairs myocardial function, but not myocardial perfusion during hyperaemia: a pilot study

    Directory of Open Access Journals (Sweden)

    van den Brom Charissa E

    2012-06-01

    Full Text Available Abstract Background Glucose intolerance is a major health problem and is associated with increased risk of progression to type 2 diabetes mellitus and cardiovascular disease. However, whether glucose intolerance is related to impaired myocardial perfusion is not known. The purpose of the present study was to study the effect of diet-induced glucose intolerance on myocardial function and perfusion during baseline and pharmacological induced hyperaemia. Methods Male Wistar rats were randomly exposed to a high fat diet (HFD or control diet (CD (n = 8 per group. After 4 weeks, rats underwent an oral glucose tolerance test. Subsequently, rats underwent (contrast echocardiography to determine myocardial function and perfusion during baseline and dipyridamole-induced hyperaemia (20 mg/kg for 10 min. Results Four weeks of HFD feeding resulted in glucose intolerance compared to CD-feeding. Contractile function as represented by fractional shortening was not altered in HFD-fed rats compared to CD-fed rats under baseline conditions. However, dipyridamole increased fractional shortening in CD-fed rats, but not in HFD-fed rats. Basal myocardial perfusion, as measured by estimate of perfusion, was similar in CD- and HFD-fed rats, whereas dipyridamole increased estimate of perfusion in CD-fed rats, but not in HFD-fed rats. However, flow reserve was not different between CD- and HFD-fed rats. Conclusions Diet-induced glucose intolerance is associated with impaired myocardial function during conditions of hyperaemia, but myocardial perfusion is maintained. These findings may result in new insights into the effect of glucose intolerance on myocardial function and perfusion during hyperaemia.

  15. 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

  16. Study of Absorption Characteristics of the Total Saponins from Radix Ilicis Pubescentis in an In Situ Single-Pass Intestinal Perfusion (SPIP Rat Model by Using Ultra Performance Liquid Chromatography (UPLC

    Directory of Open Access Journals (Sweden)

    Guojun Kuang

    2017-11-01

    Full Text Available In contrast to the extensively reported therapeutic activities, far less attention has been paid to the intestinal absorption of the total saponins from Radix Ilicis Pubescentis (in Chinese Mao-Dong-Qing, MDQ. This study aimed to investigate the intestinal absorption characteristics of ilexgenin A (C1, ilexsaponin A1 (C2, ilexsaponin B1 (C3, ilexsaponin B2 (C4, ilexsaponin B3 (DC1, and ilexoside O (DC2 when administrated with the total saponins from MDQ (MDQ-TS. An UPLC method for simultaneous determination of C1, C2, C3, C4, DC1, and DC2 in intestinal outflow perfusate was developed and validated. The absorption characteristics of MDQ-TS were investigated by evaluating the effects of intestinal segments, drug concentration, P-glycoprotein (P-gp inhibitor (verapomil, endocytosis inhibitor (amantadine and ethylene diamine tetraacetic acid (EDTA, tight junction modulator on the intestinal transportation of MDQ-TS by using a single-pass intestinal perfusion (SPIP rat model, and the influence of co-existing components on the intestinal transport of the six saponins was discussed. The results showed that effective apparent permeability (Papp of C1, C2, C3, C4, and DC2 administrated in MDQ-TS form had no segment-dependent changes at low and middle dosage levels. C1, C2, C3, D4, DC1, and DC2 administrated in MDQ-TS form all exhibited excellent transmembrane permeability with Papp > 0.12 × 10−2 cm·min−1. Meanwhile, Papp and effective absorption rate constant (Ka values for the most saponins showed concentration dependence and saturation characteristics. After combining with P-gp inhibitor of verapamil, Papp of C2, C3, and DC1 in MDQ-TS group was significantly increased up to about 2.3-fold, 1.4-fold, and 3.4-fold, respectively in comparison to that of non-verapamil added group. Verapamil was found to improve the absorption of C2, C3, and DC1, indicating the involvement of an active transport mechanism in the absorption process. Compared with the

  17. Radiation response of perfused tracheal sections

    International Nuclear Information System (INIS)

    Ford, J.R.; Maslowski, A.J.; Braby, L.A.

    2003-01-01

    Full text: A model of respiratory tissue using a perfusion culture system is being developed. We are using this system to quantify the effects of normal tissue architecture and the interaction of epithelial cells with other cell types on radiation-induced bystander effects. Tracheal tissue taken from young adult male Fischer 344 rats is imbedded in a growth factor enriched agarose matrix. The chamber is designed to allow growth medium to periodically wash the epithelial surface of the tracheal lumen while maintaining the air-interface that is necessary for the normal differentiation of the epithelium. In preliminary experiments with rat trachea we have shown that a differentiated epithelial lining can be maintained for several days. Cells can be obtained for a number of different cell culture assays for endpoints such as survival and preneoplastic transformation after irradiation

  18. 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....

  19. Gammagraphy of cerebral perfusion

    International Nuclear Information System (INIS)

    Vazquez, Silvia

    2003-01-01

    Important aspects of the gammagraphy of cerebral perfusion and the diverse clinical applications in the neurological diseases are comment in this article. We focus in the usefulness of the photon emission cerebral tomography (SPECT) and its capacity to cross the hemato encephalic barrier through the use of radiopharmacons like 99 mTc-H M-PAO and 99mTc-EDC, thus managing to offer functional data on the captantes neurons of the radiopharmacon. The clinical applications of SPECT are studied; cerebrovascular disease, transient ischemic attacks, dementias, Alzheimer disease, as well as other neurological diseases are referred. (The author)

  20. Phase correction of MR perfusion/diffusion images

    International Nuclear Information System (INIS)

    Chenevert, T.L.; Pipe, J.G.; Brunberg, J.A.; Yeung, H.N.

    1989-01-01

    Apparent diffusion coefficient (ADC) and perfusion MR sequences are exceptionally sensitive to minute motion and, therefore, are prone to bulk motions that hamper ADC/perfusion quantification. The authors have developed a phase correction algorithm to substantially reduce this error. The algorithm uses a diffusion-insensitive data set to correct data that are diffusion sensitive but phase corrupt. An assumption of the algorithm is that bulk motion phase shifts are uniform in one dimension, although they may be arbitrarily large and variable from acquisition to acquisition. This is facilitated by orthogonal section selection. The correction is applied after one Fourier transform of a two-dimensional Fourier transform reconstruction. Imaging experiments on rat and human brain demonstrate significant artifact reduction in ADC and perfusion measurements

  1. Systemic perfusion: a method of enhancing relative tumor uptake of radiolabeled monoclonal antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Wahl, R.L.; Piko, C.R.; Beers, B.A.; Geatti, O.; Johnson, J.; Sherman, P. (Michigan Univ., Ann Arbor, MI (USA). Dept. of Internal Medicine)

    1989-01-01

    The authors evaluated the feasibility of systemic vascular perfusion with saline (mimicking plasmapheresis) as a method to enhance tumor-specific monoclonal antibody (MoAb) tumor/background ratios. Perfusion in rats dropped whole-body 5G6.4 levels significantly at both perfusion times. The drop in whole-body radioactivity with perfusion was significantly greater for the animals perfused at 4 h post i.v. 5G6.4 antibody injection (48.3 +- 5.1%) than for those perfused at 24h post i.v. antibody injection (32.9 +- 2.9%). In the nude mice with ovarian cancer xenografts, gamma camera images of tumors were visually and quantitatively by computer image analysis enhanced by perfusion, with a 2.33-fold greater decline in whole body uptake than in the tumor. These studies show that much background antibody radioactivity can be removed using whole-body perfusion with saline, that the decline in whole body activity is larger with 4 than 24h perfusion and that tumor imaging can be enhanced by this approach. This and similar approaches that increase relative tumor antibody uptake such as plasmapheresis may be useful in imaging and therapy with radiolabeled antibodies.

  2. Absorption mechanism of three curcumin constituents through in situ intestinal perfusion method

    Directory of Open Access Journals (Sweden)

    Y.-H. Wang

    2017-09-01

    Full Text Available This study aimed to investigate the absorption mechanism of three curcumin constituents in rat small intestines. Self-emulsification was used to solubilize the three curcumin constituents, and the rat in situ intestinal perfusion method was used to study factors on drug absorption, including drug mass concentration, absorption site, and the different types and concentrations of absorption inhibitors. Within the scope of experimental concentrations, three curcumin constituents were absorbed in rat small intestines through the active transport mechanism.

  3. 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.)

  4. Double tracer autoradiographic method for sequential evaluation of regional cerebral perfusion

    International Nuclear Information System (INIS)

    Matsuda, H.; Tsuji, S.; Oba, H.; Kinuya, K.; Terada, H.; Sumiya, H.; Shiba, K.; Mori, H.; Hisada, K.; Maeda, T.

    1989-01-01

    A new double tracer autoradiographic method for the sequential evaluation of altered regional cerebral perfusion in the same animal is presented. This method is based on the sequential injection of two tracers, 99m Tc-hexamethylpropyleneamine oxime and N-isopropyl-( 125 I)p-iodoamphetamine. This method is validated in the assessment of brovincamine effects on regional cerebral perfusion in an experimental model of chronic brain ischemia in the rat. The drug enhanced perfusion recovery in low-flow areas, selectively in surrounding areas of infarction. The results suggest that this technique is of potential use in the study of neuropharmacological effects applied during the experiment

  5. 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.

  6. 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...

  7. 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)

  8. Quantitative lung perfusion evaluation using Fourier decomposition perfusion MRI.

    Science.gov (United States)

    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.

  9. 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

  10. 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

  11. Dynamic CT myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Caruso, Damiano; Eid, Marwen; Schoepf, U. Joseph; Jin, Kwang Nam; Varga-Szemes, Akos; Tesche, Christian; Mangold, Stefanie

    2016-01-01

    Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  12. Dynamic CT myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncological and Pathological Sciences, University of Rome “Sapienza”, Latina (Italy); Eid, Marwen [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States); Jin, Kwang Nam [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul (Korea, Republic of); Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Tesche, Christian [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich (Germany); Mangold, Stefanie [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen (Germany); and others

    2016-10-15

    Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  13. Lung perfusion scintigraphy by SPECT

    International Nuclear Information System (INIS)

    Hirayama, Takanobu

    1990-01-01

    The initial study reports the characteristic performance using lung segmental phantom filled in Tc-99m pertechnetate. To evaluate the segmental defect in lung perfusion scintigraphy, we applied Bull's-eye analysis in addition to planar image set. Bull's-eye analysis especially facilitated the interpretation in both middle and lower lobes. Subsequently, to evolute the clinical application of Bull's-eye analysis, pulmonary scintigraphy was performed on 10 normal subjects and 60 patients with several pulmonary diseases. Of interest, Bull's-eye analysis, however, encouraged the interpretation in both lower lobes. To calculate the extention and severity of perfusion defect, the present study describes Bull's-eye analysis. Quantitative scoring showed higher in patients with lung cancer than those with pulmonary tuberculosis. The present study focus that Bull's-eye analysis can be useful for evaluating perfusion in patients with a couple of pulmonary diseases. (author)

  14. Effect of myocardial perfusion and metabolic interventions on cardiac kinetics of phenylpentadecanoic acid (IPPA) I 123

    Energy Technology Data Exchange (ETDEWEB)

    Reske, S.N.; Schoen, S.; Schmitt, W.; Knopp, R.; Winkler, C.; Machulla, H.J.

    1986-08-01

    The effect of regional myocardial perfusion and flow-independent adrenergic stimulation, as well as lactate-mediated inhibition of cardiac lipolysis, on cardiac IPPA uptake and metabolism was examined in canine hearts (flow studies) and in the isolated perfused Langendorff rat heart (metabolic interventions). In both normal and ischaemic myocardium, local perfusion is a major determinant of cardiac IPPA uptake. In pacing-induced hyperaemia, the strict flow-dependence of cardiac IPPA uptake is not preserved. Adrenergic stimulation raises the rate of oxidation of both palmitic acid /sup 14/C and IPPA. This change is reflected by increased metabolite production released into the perfusate and radioactivity clearance recorded externally. Lactate in high concentrations exerts the opposite effect on cardiac free fatty acid oxidation. IPPA is stored in this condition preferentially in tissue phospholipids and triglycerides.

  15. Effect of myocardial perfusion and metabolic interventions on cardiac kinetics of phenylpentadecanoic acid (IPPA) I 123

    International Nuclear Information System (INIS)

    Reske, S.N.; Schoen, S.; Schmitt, W.; Knopp, R.; Winkler, C.; Machulla, H.J.

    1986-01-01

    The effect of regional myocardial perfusion and flow-independent adrenergic stimulation, as well as lactate-mediated inhibition of cardiac lipolysis, on cardiac IPPA uptake and metabolism was examined in canine hearts (flow studies) and in the isolated perfused Langendorff rat heart (metabolic interventions). In both normal and ischaemic myocardium, local perfusion is a major determinant of cardiac IPPA uptake. In pacing-induced hyperaemia, the strict flow-dependence of cardiac IPPA uptake is not preserved. Adrenergic stimulation raises the rate of oxidation of both palmitic acid 14 C and IPPA. This change is reflected by increased metabolite production released into the perfusate and radioactivity clearance recorded externally. Lactate in high concentrations exerts the opposite effect on cardiac free fatty acid oxidation. IPPA is stored in this condition preferentially in tissue phospholipids and triglycerides. (orig.)

  16. Rats

    Directory of Open Access Journals (Sweden)

    Alexey Kondrashov

    2012-01-01

    Full Text Available We aimed to perform a chemical analysis of both Alibernet red wine and an alcohol-free Alibernet red wine extract (AWE and to investigate the effects of AWE on nitric oxide and reactive oxygen species production as well as blood pressure development in normotensive Wistar Kyoto (WKY and spontaneously hypertensive rats (SHRs. Total antioxidant capacity together with total phenolic and selected mineral content was measured in wine and AWE. Young 6-week-old male WKY and SHR were treated with AWE (24,2 mg/kg/day for 3 weeks. Total NOS and SOD activities, eNOS and SOD1 protein expressions, and superoxide production were determined in the tissues. Both antioxidant capacity and phenolic content were significantly higher in AWE compared to wine. The AWE increased NOS activity in the left ventricle, aorta, and kidney of SHR, while it did not change NOS activity in WKY rats. Similarly, increased SOD activity in the plasma and left ventricle was observed in SHR only. There were no changes in eNOS and SOD1 expressions. In conclusion, phenolics and minerals included in AWE may contribute directly to increased NOS and SOD activities of SHR. Nevertheless, 3 weeks of AWE treatment failed to affect blood pressure of SHR.

  17. 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

  18. Experimental study of CT perfusion in hepatitis, hepatic fibrosis and early stage of cirrhosis

    International Nuclear Information System (INIS)

    Guan Sheng; Zhao Weidong; Zhou Kangrong; Peng Weijun; Mao Jian; Tang Feng; Wang Yong; Cao Guang; Sun Fei

    2005-01-01

    Objective: To investigate the value of CT perfusion in the early diagnosis of hepatic diffuse disease. Methods: Fourteen male Wistar rats of control group and 14 of test group at stages of hepatitis, hepatic fibrosis, hepatic cirrhosis which were induced with diethylnitrosamine (DEN), were studied with CT perfusion respectively. CT perfusion data of different stages were compared and pathologic analysis were performed. Results: Density-time curves of CT perfusion were satisfactory and all perfusion data could be obtained. During the period of hepatitis developing into early stage of hepatic cirrhosis, hepatic artery flow (HAF) trended to increase in test group, mean transmit time (MTT) prolonged obviously, blood flow (BF) and volume (BV) declined. While in control group, HAF declined slightly, MTT, BV and BF increased. Statistic analysis showed the differences of HAF and MTT at different stages between control and test groups were significant (P<0.05 ); the differences of BV and BF between hepatitis and hepatic cirrhosis, hepatic fibrosis and early stage of hepatic cirrhosis in test group were significant (P<0.05), but no significant difference between hepatitis and hepatic fibrosis. The corresponding pathologic changes at stage of hepatitis was swelling of hepatic cells; sinusoids cap illarization and deposition of collagen in the extravascular Disse's spaces were the main changes relating to hepatic blood perfusion at stage of fibrosis and early stage of cirrhosis. Conclusion: The method of CT scan can reflect some changes of hepatic blood perfusion in rats with hepatitis, hepatic fibrosis and early stage of cirrhosis. The data of CT perfusion, especially the changes should be valuable for clinical early diagnosis, treatment and follow-up. (authors)

  19. Ultrastructure of the endolymphatic duct in the rat. Fixation and preservation

    DEFF Research Database (Denmark)

    Qvortrup, K; Rostgaard, J

    1993-01-01

    Ten rats were vascular-perfused at subphysiologic as well as physiologic pressures, 80 mmHg and 120 mmHg, respectively, employing a pressure feed-back controlled peristaltic pump and an isotonic perfusate/fixative with colloids (2% Dextran) and a hypertonic perfusate/fixative without colloids, 300...

  20. 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...

  1. Pulmonary ventilation/perfusion scan

    Science.gov (United States)

    ... to stop eating (fast), be on a special diet, or take any medicines before the test. A chest x-ray is usually done before or after a ventilation and perfusion scan. You wear a hospital gown or comfortable clothing that does not have ...

  2. 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

  3. 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.)

  4. Exercise training reinstates cortico-cortical sensorimotor functional connectivity following striatal lesioning: Development and application of a subregional-level analytic toolbox for perfusion autoradiographs of the rat brain

    Science.gov (United States)

    Peng, Yu-Hao; Heintz, Ryan; Wang, Zhuo; Guo, Yumei; Myers, Kalisa; Scremin, Oscar; Maarek, Jean-Michel; Holschneider, Daniel

    2014-12-01

    Current rodent connectome projects are revealing brain structural connectivity with unprecedented resolution and completeness. How subregional structural connectivity relates to subregional functional interactions is an emerging research topic. We describe a method for standardized, mesoscopic-level data sampling from autoradiographic coronal sections of the rat brain, and for correlation-based analysis and intuitive display of cortico-cortical functional connectivity (FC) on a flattened cortical map. A graphic user interface “Cx-2D” allows for the display of significant correlations of individual regions-of-interest, as well as graph theoretical metrics across the cortex. Cx-2D was tested on an autoradiographic data set of cerebral blood flow (CBF) of rats that had undergone bilateral striatal lesions, followed by 4 weeks of aerobic exercise training or no exercise. Effects of lesioning and exercise on cortico-cortical FC were examined during a locomotor challenge in this rat model of Parkinsonism. Subregional FC analysis revealed a rich functional reorganization of the brain in response to lesioning and exercise that was not apparent in a standard analysis focused on CBF of isolated brain regions. Lesioned rats showed diminished degree centrality of lateral primary motor cortex, as well as neighboring somatosensory cortex--changes that were substantially reversed in lesioned rats following exercise training. Seed analysis revealed that exercise increased positive correlations in motor and somatosensory cortex, with little effect in non-sensorimotor regions such as visual, auditory, and piriform cortex. The current analysis revealed that exercise partially reinstated sensorimotor FC lost following dopaminergic deafferentation. Cx-2D allows for standardized data sampling from images of brain slices, as well as analysis and display of cortico-cortical FC in the rat cerebral cortex with potential applications in a variety of autoradiographic and histologic

  5. The effect of S. pneumoniae bacteremia on cerebral blood flow autoregulation in rats

    DEFF Research Database (Denmark)

    Pedersen, Michael; Brandt, Christian T.; Knudsen, Gitte Moos

    2008-01-01

    during incremental reductions in cerebral perfusion pressure (CPP) by controlled hemorrhage. Autoregulation was preserved in all rats without meningitis (groups A and E) and was lost in 24 of 25 meningitis rats (groups B, C, and D) (P

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Hyperventilation, cerebral perfusion, and syncope

    DEFF Research Database (Denmark)

    Immink, R V; Pott, F C; Secher, N H

    2014-01-01

    dioxide (PaCO2) and oxygen (PaO2) partial pressures so that hypercapnia/hypoxia increases and hypocapnia/hyperoxia reduces global cerebral blood flow. Cerebral hypoperfusion and TLOC have been associated with hypocapnia related to HV. Notwithstanding pronounced cerebrovascular effects of PaCO2...... the contribution of a low PaCO2 to the early postural reduction in middle cerebral artery blood velocity is transient. HV together with postural stress does not reduce cerebral perfusion to such an extent that TLOC develops. However when HV is combined with cardiovascular stressors like cold immersion or reduced...... cardiac output brain perfusion becomes jeopardized. Whether, in patients with cardiovascular disease and/or defect, cerebral blood flow cerebral control HV-induced hypocapnia elicits cerebral hypoperfusion, leading to TLOC, remains to be established....

  8. Myocardial perfusion modeling using MRI

    DEFF Research Database (Denmark)

    Larsson, H B; Fritz-Hansen, T; Rostrup, Egill

    1996-01-01

    In the present study, it is shown that it is possible to quantify myocardial perfusion using magnetic resonance imaging in combination with gadolinium diethylenetriaminopentaacetic acid (Gd-DTPA). Previously, a simple model and method for measuring myocardial perfusion using an inversion recovery...... turbo-FLASH (fast low-angle shot) sequence and Gd-DTPA has been presented. Here, an extension of the model is presented taking into account fast and slow water exchange between the compartments, enabling the calculation of the unidirectional influx constant (Ki) for Gd-DTPA, the distribution volume...... of Gd-DTPA (lambda), the vascular blood volume (Vb), and the time delay through the coronary arteries (delta T). The model was evaluated by computer simulation and used on experimental results from seven healthy subjects. The results in the healthy volunteers for a region of interest placed...

  9. Dosimetry in myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Toledo, Janine M.; Trindade, Bruno; Ribeiro, Tarcisio P.C. [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte (Brazil). Dept. de Engenharia Nuclear. Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2011-07-01

    This paper conducts a dosimetric investigation on the myocardial perfusion image protocol, together with a literature reviewing, motivated by the significant statistic increasing on mortality, morbidity and disability associated with cardiovascular disease, surpassing infectious diseases. Nuclear Cardiology plays a role n the diagnostic functional evaluation of the heart and in the prognostic of patients with suspected or known cardiac ischemia. In the context of unstable myocardial ischemic syndrome, myocardial perfusion scintigraphy is a non-invasive procedure performed by administering a radiopharmaceutical targeted to the heart. As tool for this study are that the images obtained by thoracic angiotomography and abdominal aorta as a anatomic and functional information for model reproduction in SISCODES - System of Codes for Absorbed Dose Calculations based on Stochastic Methods. Data were manipulated in order to create a voxel computational model of the heart to be running in MCNP - Monte Carlo Neutron Particle Code. . It was assumed a homogeneous distribution of Tl-201 in cardiac muscle. Simulations of the transport of particles through the voxel and the interaction with the heart tissue were performed. As a result, the isodose curves in the heart model are displayed as well as the dose versus volume histogram of the heart muscle. We conclude that the present computational tools can generate doses distributed in myocardial perfusion. (author)

  10. Dosimetry in myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Toledo, Janine M.; Trindade, Bruno; Ribeiro, Tarcisio P.C.

    2011-01-01

    This paper conducts a dosimetric investigation on the myocardial perfusion image protocol, together with a literature reviewing, motivated by the significant statistic increasing on mortality, morbidity and disability associated with cardiovascular disease, surpassing infectious diseases. Nuclear Cardiology plays a role n the diagnostic functional evaluation of the heart and in the prognostic of patients with suspected or known cardiac ischemia. In the context of unstable myocardial ischemic syndrome, myocardial perfusion scintigraphy is a non-invasive procedure performed by administering a radiopharmaceutical targeted to the heart. As tool for this study are that the images obtained by thoracic angiotomography and abdominal aorta as a anatomic and functional information for model reproduction in SISCODES - System of Codes for Absorbed Dose Calculations based on Stochastic Methods. Data were manipulated in order to create a voxel computational model of the heart to be running in MCNP - Monte Carlo Neutron Particle Code. . It was assumed a homogeneous distribution of Tl-201 in cardiac muscle. Simulations of the transport of particles through the voxel and the interaction with the heart tissue were performed. As a result, the isodose curves in the heart model are displayed as well as the dose versus volume histogram of the heart muscle. We conclude that the present computational tools can generate doses distributed in myocardial perfusion. (author)

  11. 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

  12. 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.)

  13. Improvements in the technique of vascular perfusion-fixation employing a fluorocarbon-containing perfusate and a peristaltic pump controlled by pressure feedback

    DEFF Research Database (Denmark)

    Rostgaard, J; Qvortrup, Klaus; Poulsen, Steen Seier

    1993-01-01

    A new improved technique for whole-body perfusion-fixation of rats and other small animals is described. The driving force is a peristaltic pump which is feedback regulated by a pressure transducer that monitors the blood-perfusion pressure in the left ventricle of the heart. The primary perfusate...... to cannulate the heart; the outer and inner barrels of the cannula are connected to the peristaltic pump and to the pressure transducer, respectively. The tissue oxygen tension in the rat is monitored by a subcutaneous oxygen electrode. Measurements showed that tissue hypoxia/anoxia did not develop before......-fixative is composed of a blood substitute--13.3% oxygenated fluorocarbon FC-75--in 0.05 M cacodylate buffer (pH 7.4) with a 2% glutaraldehyde. The secondary perfusate-fixative is composed of 2% glutaraldehyde in 0.05 M cacodylate buffer (pH 7.4) with 20 mM CaCl2. A double-barrelled, self-holding cannula is used...

  14. MDMA ‘ecstasy’ increases cerebral cortical perfusion determined by bolus-tracking arterial spin labelling (btASL) MRI

    Science.gov (United States)

    Rouine, J; Gobbo, O L; Campbell, M; Gigliucci, V; Ogden, I; McHugh Smith, K; Duffy, P; Behan, B; Byrne, D; Kelly, M E; Blau, C W; Kerskens, C M; Harkin, A

    2013-01-01

    Background and Purpose The purpose of this study was to assess cerebral perfusion changes following systemic administration of the recreational drug 3,4-methylendioxymethamphetamine (MDMA ‘ecstasy’) to rats. Experimental Approach Cerebral perfusion was quantified using bolus-tracking arterial spin labelling (btASL) MRI. Rats received MDMA (20 mg·kg−1; i.p.) and were assessed 1, 3 or 24 h later. Rats received MDMA (5 or 20 mg·kg−1; i.p.) and were assessed 3 h later. In addition, rats received MDMA (5 or 10 mg·kg−1; i.p.) or saline four times daily over 2 consecutive days and were assessed 8 weeks later. Perfusion-weighted images were generated in a 7 tesla (7T) MRI scanner and experimental data was fitted to a quantitative model of cerebral perfusion to generate mean transit time (MTT), capillary transit time (CTT) and signal amplitude. Key Results MDMA reduces MTT and CTT and increases amplitude in somatosensory and motor cortex 1 and 3 h following administration, indicative of an increase in perfusion. Prior exposure to MDMA provoked a long-term reduction in cortical 5-HT concentration, but did not produce a sustained effect on cerebral cortical perfusion. The response to acute MDMA challenge (20 mg·kg−1; i.p.) was attenuated in these animals indicating adaptation in response to prior MDMA exposure. Conclusions and Implications MDMA provokes changes in cortical perfusion, which are quantifiable by btASL MRI, a neuroimaging tool with translational potential. Future studies are directed towards elucidation of the mechanisms involved and correlating changes in cerebrovascular function with potential behavioural deficits associated with drug use. PMID:23517012

  15. 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...

  16. Spatial relationship between tumor perfusion and endogeneous glucose distribution

    International Nuclear Information System (INIS)

    Schroeder, T.; Larrier, N.; Viglianti, B.; Rabbani, Z.N.; Peltz, C.; Vujascovic, Z.; Dewhirst, M.W.

    2003-01-01

    Earlier studies detecting glucose in tissue and solid tumors by bioluminescence imaging suggested, that glucose distribution patterns may be spatially related to functional vascularity. The purpose of this study was to evaluate this relationship by comparing glucose distribution patterns as determined by bioluminescence imaging to perfusion patterns of endogeneous Hoechst 33342 in rats bearing mammary carcinomas. R 3230 mammary carcinoma cells have been implanted subcutaneously into 7 female Fischer 344 rats. Two months post implantation, after injection of Hoechst 33342 the tumors were removed and snap frozen to conserve metabolite levels. Concomitantly, blood was sampled from the animals for analysis of glucose concentrations using a micodialysis analyzer. Cryosections of the tumors have been prepared, and every slice has been analyzed for both, Hoechst binding by fluorescence microscopy, and for glucose distribution patterns using bioluminescence imaging. In many cases vascular structures could be retrieved by the spatial pattern of glucose distribution. In some cases however, higher glucose concentrations could be found independent from Hoechst signal. On the other hand, regions of high Hoechst signal are not necessarily correlated with high glucose concentrations. When comparing blood and tissue glucose levels, tissue glucose content as measured with bioluminescence imaging (1.9-3.5 mM) is considerably lower than blood glucose (5.6-8.0 mM), demonstrating the expected gradient from blood to tissue. This study demonstrates the feasibility of monitoring glucose gradients in relation to functional vasculature throughout the body, from blood down to tissue or tumor and further, throughout the microenvironment of the solid tumor. Glucose distribution patterns may be an important tool in perfusion studies, e. g. in detecting the direction of blood flow in ex-vivo samples or in estimating glucose consumption rates of tumor cells adjacent to or in between perfused

  17. 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

  18. Quality assessment of a placental perfusion protocol

    DEFF Research Database (Denmark)

    Mathiesen, Line; Mose, Tina; Mørck, Thit Juul

    2010-01-01

    mlh(-1) from the fetal reservoir) when adding 2 (n=7) and 20mg (n=9) FITC-dextran/100ml fetal perfusion media. Success rate of the Copenhagen placental perfusions is provided in this study, including considerations and quality control parameters. Three checkpoints suggested to determine success rate...

  19. Regional Cerebral Perfusion in Progressive Supranuclear Palsy

    Energy Technology Data Exchange (ETDEWEB)

    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

  20. 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...

  1. 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)

  2. Increased peripheral vascular disease risk progressively constrains perfusion adaptability in the skeletal muscle microcirculation

    Science.gov (United States)

    Butcher, Joshua T.; Frisbee, Stephanie J.; Olfert, I. Mark; Chantler, Paul D.; Tabone, Lawrence E.; d'Audiffret, Alexandre C.; Shrader, Carl D.; Goodwill, Adam G.; Stapleton, Phoebe A.; Brooks, Steven D.; Brock, Robert W.; Lombard, Julian H.

    2015-01-01

    To determine the impact of progressive elevations in peripheral vascular disease (PVD) risk on microvascular function, we utilized eight rat models spanning “healthy” to “high PVD risk” and used a multiscale approach to interrogate microvascular function and outcomes: healthy: Sprague-Dawley rats (SDR) and lean Zucker rats (LZR); mild risk: SDR on high-salt diet (HSD) and SDR on high-fructose diet (HFD); moderate risk: reduced renal mass-hypertensive rats (RRM) and spontaneously hypertensive rats (SHR); high risk: obese Zucker rats (OZR) and Dahl salt-sensitive rats (DSS). Vascular reactivity and biochemical analyses demonstrated that even mild elevations in PVD risk severely attenuated nitric oxide (NO) bioavailability and caused progressive shifts in arachidonic acid metabolism, increasing thromboxane A2 levels. With the introduction of hypertension, arteriolar myogenic activation and adrenergic constriction were increased. However, while functional hyperemia and fatigue resistance of in situ skeletal muscle were not impacted with mild or moderate PVD risk, blood oxygen handling suggested an increasingly heterogeneous perfusion within resting and contracting skeletal muscle. Analysis of in situ networks demonstrated an increasingly stable and heterogeneous distribution of perfusion at arteriolar bifurcations with elevated PVD risk, a phenomenon that was manifested first in the distal microcirculation and evolved proximally with increasing risk. The increased perfusion distribution heterogeneity and loss of flexibility throughout the microvascular network, the result of the combined effects on NO bioavailability, arachidonic acid metabolism, myogenic activation, and adrenergic constriction, may represent the most accurate predictor of the skeletal muscle microvasculopathy and poor health outcomes associated with chronic elevations in PVD risk. PMID:26702145

  3. 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...

  4. Kinetics of tissue distribution and elimination of 4,4'-methylene bis(2-chloroaniline) in rats

    International Nuclear Information System (INIS)

    Tobes, M.C.; Brown, L.E.; Chin, B.; Marsh, D.D.

    1983-01-01

    The tissue distribution kinetics and elimination of 4,4'-methylene bis(2-chloroaniline) (MBOCA) in rats was studied after a single dose of [ 14 C]MBOCA (0.49 mg/kg body weight, i.v.). The highest concentrations of radioactivity were in the small intestine, liver, adipose, lung, kidney, skin, and adrenals. For most tissues, a rapid decrease in radioactivity was followed by a slower decrease except for the small intestine, adipose and skin which demonstrated transient increases. Subcellular distribution in liver at 1 h showed radioactivity in all cell fractions. Although very lipophilic, [ 14 C]MBOCA was completely eliminated within 48 h with the major route via the feces (73.4%). (Auth.)

  5. 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

  6. Hypercapnic acidosis modulates inflammation, lung mechanics, and edema in the isolated perfused lung.

    Science.gov (United States)

    De Smet, Hilde R; Bersten, Andrew D; Barr, Heather A; Doyle, Ian R

    2007-12-01

    Low tidal volume (V(T)) ventilation strategies may be associated with permissive hypercapnia, which has been shown by ex vivo and in vivo studies to have protective effects. We hypothesized that hypercapnic acidosis may be synergistic with low V(T) ventilation; therefore, we studied the effects of hypercapnia and V(T) on unstimulated and lipopolysaccharide-stimulated isolated perfused lungs. Isolated perfused rat lungs were ventilated for 2 hours with low (7 mL/kg) or moderately high (20 mL/kg) V(T) and 5% or 20% CO(2), with lipopolysaccharide or saline added to the perfusate. Hypercapnia resulted in reduced pulmonary edema, lung stiffness, tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6) in the lavage and perfusate. The moderately high V(T) did not cause lung injury but increased lavage IL-6 and perfusate IL-6 as well as TNF-alpha. Pulmonary edema and respiratory mechanics improved, possibly as a result of a stretch-induced increase in surfactant turnover. Lipopolysaccharide did not induce significant lung injury. We conclude that hypercapnia exerts a protective effect by modulating inflammation, lung mechanics, and edema. The moderately high V(T) used in this study stimulated inflammation but paradoxically improved edema and lung mechanics with an associated increase in surfactant release.

  7. Biodistribution and stability studies of [18F]Fluoroethylrhodamine B, a potential PET myocardial perfusion agent

    International Nuclear Information System (INIS)

    Gottumukkala, Vijay; Heinrich, Tobias K.; Baker, Amanda; Dunning, Patricia; Fahey, Frederic H.; Treves, S. Ted; Packard, Alan B.

    2010-01-01

    Introduction: Fluorine-18-labeled rhodamine B was developed as a potential positron emission tomography (PET) tracer for the evaluation of myocardial perfusion, but preliminary studies in mice showed no accumulation in the heart suggesting that it was rapidly hydrolyzed in vivo in mice. A study was therefore undertaken to further evaluate this hypothesis. Methods: [ 18 F]Fluoroethylrhodamine B was equilibrated for 2 h at 37 deg. C in human, rat and mouse serum and in phosphate-buffered saline. Samples were removed periodically and assayed by high-performance liquid chromatography. Based on the results of the stability study, microPET imaging and a biodistribution study were carried out in rats. Results: In vitro stability studies demonstrated that [ 18 F]fluoroethylrhodamine B much more stable in rat and human sera than in mouse serum. After 2 h, the compound was >80% intact in rat serum but 18 F-labeled rhodamines should accumulate in the heart. Conclusions: [ 18 F]Fluoroethylrhodamine B is more stable in rat and human sera than it is in mouse serum. This improved stability is demonstrated by the high uptake of the tracer in the rat heart in comparison to the absence of visible uptake in the mouse heart. These observations suggest that 18 F-labeled rhodamines are promising candidates for more extensive evaluation as PET tracers for the evaluation of myocardial perfusion.

  8. Aliskiren toxicity in juvenile rats is determined by ontogenic regulation of intestinal P-glycoprotein expression

    International Nuclear Information System (INIS)

    Hoffmann, Peter; Beckman, David; McLean, Lee Anne; Yan, Jing-He

    2014-01-01

    Juvenile rat toxicity studies with the direct renin inhibitor aliskiren were initiated to support treatment in the pediatric population. In Study 1, aliskiren was administered orally to juvenile rats at doses of 0, 30, 100 or 300 mg/kg/day with repeated dosing from postpartum day (PPD) 8 to PPD 35/36. In-life, clinical pathology, anatomic pathology, and toxicokinetics evaluations were performed. In Study 2, single oral doses of aliskiren (0, 100 or 300 mg/kg) were given to 14-, 21-, 24-, 28-, 31- or 36-day-old rats; in-life data and toxicokinetics were evaluated. Study 3 was a single dose (3 mg/kg i.v.) pharmacokinetic study in juvenile rats on PPD 8, 14, 21 and 28. In Study 4, naïve rats were used to investigate ontogenic changes of the multidrug-resistant protein 1 (MDR1) and the organic anion transporting polypeptide (OATP) mRNA in several organs. Oral administration of aliskiren at 100 and 300 mg/kg caused unexpected mortality and severe morbidity in 8-day-old rats. Aliskiren plasma and tissue concentrations were increased in rats aged 21 days and younger. Expression of MDR1 and OATP mRNA in the intestine, liver and brain was significantly lower in very young rats. In conclusion, severe toxicity and increased exposure in very young rats after oral administration of aliskiren are considered to be the result of immature drug transporter systems. Immaturity of MDR1 in enterocytes appears to be the most important mechanism responsible for the high exposure. - Highlights: • Aliskiren was orally administered to juvenile rats. • Unexpected severe toxicity and acute mortality occurred in rats aged 8 days. • Toxicity was associated with increased aliskiren plasma and tissue exposure. • Developmental changes of exposure correlated with ontogeny of transporters. • Immaturity of MDR1 in enterocytes causes increased exposure in very young rats

  9. Aliskiren toxicity in juvenile rats is determined by ontogenic regulation of intestinal P-glycoprotein expression

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Peter, E-mail: peterk.hoffmann@novartis.com [Preclinical Safety, Novartis Institutes for BioMedical Research, East Hanover, NJ (United States); Beckman, David; McLean, Lee Anne [Preclinical Safety, Novartis Institutes for BioMedical Research, East Hanover, NJ (United States); Yan, Jing-He [Drug Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research, East Hanover, NJ (United States)

    2014-02-15

    Juvenile rat toxicity studies with the direct renin inhibitor aliskiren were initiated to support treatment in the pediatric population. In Study 1, aliskiren was administered orally to juvenile rats at doses of 0, 30, 100 or 300 mg/kg/day with repeated dosing from postpartum day (PPD) 8 to PPD 35/36. In-life, clinical pathology, anatomic pathology, and toxicokinetics evaluations were performed. In Study 2, single oral doses of aliskiren (0, 100 or 300 mg/kg) were given to 14-, 21-, 24-, 28-, 31- or 36-day-old rats; in-life data and toxicokinetics were evaluated. Study 3 was a single dose (3 mg/kg i.v.) pharmacokinetic study in juvenile rats on PPD 8, 14, 21 and 28. In Study 4, naïve rats were used to investigate ontogenic changes of the multidrug-resistant protein 1 (MDR1) and the organic anion transporting polypeptide (OATP) mRNA in several organs. Oral administration of aliskiren at 100 and 300 mg/kg caused unexpected mortality and severe morbidity in 8-day-old rats. Aliskiren plasma and tissue concentrations were increased in rats aged 21 days and younger. Expression of MDR1 and OATP mRNA in the intestine, liver and brain was significantly lower in very young rats. In conclusion, severe toxicity and increased exposure in very young rats after oral administration of aliskiren are considered to be the result of immature drug transporter systems. Immaturity of MDR1 in enterocytes appears to be the most important mechanism responsible for the high exposure. - Highlights: • Aliskiren was orally administered to juvenile rats. • Unexpected severe toxicity and acute mortality occurred in rats aged 8 days. • Toxicity was associated with increased aliskiren plasma and tissue exposure. • Developmental changes of exposure correlated with ontogeny of transporters. • Immaturity of MDR1 in enterocytes causes increased exposure in very young rats.

  10. 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.

  11. 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

  12. 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.)

  13. Dynamic contrast enhanced MRI for perfusion quantification

    DEFF Research Database (Denmark)

    Andersen, Irene Klærke

    2002-01-01

    Magnetic resonance imaging, during bolus passage of a paramagnetic contrast agent, is used world-wide to obtain parameters that reflect the pathological state of tissue. Abnormal perfusion occurs in diseases such as stoke and tumour. Consequently, perfusion quantication could have signi cant...... clinical value both in diagnosis and treatment of such pathologies. One approach for perfusion quanti cation involves using the contrast mechanism that a ects the transverse relaxation rates of the magnetization, R2 or R 2 , since this provides the most pronounced effect. However, the linearity between...

  14. 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

  15. 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

  16. MRI of pulmonary perfusion; MRT der Lungenperfusion

    Energy Technology Data Exchange (ETDEWEB)

    Fink, C. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen (Germany). Institut fuer Klinische Radiologie; Deutsches Krebsforschungszentrum (DKFZ), Abteilung Radiologie, Heidelberg (Germany); Risse, F.; Semmler, W. [Deutsches Krebsforschungszentrum (DKFZ), Abteilung Medizinische Physik in der Radiologie, Heidelberg (Germany); Schoenberg, S.O.; Reiser, M.F. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen (Germany). Institut fuer Klinische Radiologie; Kauczor, H.-U. [Deutsches Krebsforschungszentrum (DKFZ), Abteilung Radiologie, Heidelberg (Germany)

    2006-04-15

    Lung perfusion is a crucial prerequisite for effective gas exchange. Quantification of pulmonary perfusion is important for diagnostic considerations and treatment planning in various diseases of the lungs. Besides disorders of pulmonary vessels such as acute pulmonary embolism and pulmonary hypertension, these also include diseases of the respiratory tract and lung tissue as well as pulmonary tumors. This contribution presents the possibilities and technical requirements of MRI for diagnostic work-up of pulmonary perfusion. (orig.) [German] Die Perfusion der Lunge ist eine entscheidende Voraussetzung fuer einen effektiven Gasaustausch. Die Bestimmung der Lungenperfusion ist bei verschiedenen Erkrankungen der Lunge fuer Diagnostik und Therapieplanung bedeutsam. Hierzu zaehlen neben Erkrankungen der Lungengefaesse wie akute Lungenembolie und pulmonale Hypertension ebenso Erkrankungen der Atemwege, des Lungengeruests und Lungentumoren. In diesem Beitrag werden die Moeglichkeiten und technischen Voraussetzungen der MRT zur Diagnostik der Lungenperfusion dargestellt. (orig.)

  17. Albumin modulates S1P delivery from red blood cells in perfused microvessels: mechanism of the protein effect.

    Science.gov (United States)

    Adamson, R H; Clark, J F; Radeva, M; Kheirolomoom, A; Ferrara, K W; Curry, F E

    2014-04-01

    Removal of plasma proteins from perfusates increases vascular permeability. The common interpretation of the action of albumin is that it forms part of the permeability barrier by electrostatic binding to the endothelial glycocalyx. We tested the alternate hypothesis that removal of perfusate albumin in rat venular microvessels decreased the availability of sphingosine-1-phosphate (S1P), which is normally carried in plasma bound to albumin and lipoproteins and is required to maintain stable baseline endothelial barriers (Am J Physiol Heart Circ Physiol 303: H825-H834, 2012). Red blood cells (RBCs) are a primary source of S1P in the normal circulation. We compared apparent albumin permeability coefficients [solute permeability (Ps)] measured using perfusates containing albumin (10 mg/ml, control) and conditioned by 20-min exposure to rat RBCs with Ps when test perfusates were in RBC-conditioned protein-free Ringer solution. The control perfusate S1P concentration (439 ± 46 nM) was near the normal plasma value at 37 °C and established a stable baseline Ps (0.9 ± 0.4 × 10(-6) cm/s). Ringer solution perfusate contained 52 ± 8 nM S1P and increased Ps more than 10-fold (16.1 ± 3.9 × 10(-6) cm/s). Consistent with albumin-dependent transport of S1P from RBCs, S1P concentrations in RBC-conditioned solutions decreased as albumin concentration, hematocrit, and temperature decreased. Protein-free Ringer solution perfusates that used liposomes instead of RBCs as flow markers failed to maintain normal permeability, reproducing the "albumin effect" in these mammalian microvessels. We conclude that the albumin effect depends on the action of albumin to facilitate the release and transport of S1P from RBCs that normally provide a significant amount of S1P to the endothelium.

  18. 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.

  19. Improved exercise myocardial perfusion during lidoflazine therapy

    International Nuclear Information System (INIS)

    Shapiro, W.; Narahara, K.A.; Park, J.

    1983-01-01

    Lidoflazine is a synthetic drug with calcium-channel blocking effects. In a study of 6 patients with severe classic angina pectoris, single-blind administration of lidoflazine was associated with improved myocardial perfusion during exercise as determined by thallium-201 stress scintigraphy. These studies demonstrate that lidoflazine therapy is associated with relief of angina, an increased physical work capacity, and improved regional myocardial perfusion during exercise

  20. Measurement of myocardial perfusion using magnetic resonance

    DEFF Research Database (Denmark)

    Fritz-Hansen, T.; Jensen, L.T.; Larsson, H.B.

    2008-01-01

    Cardiac magnetic resonance imaging (MRI) has evolved rapidly. Recent developments have made non-invasive quantitative myocardial perfusion measurements possible. MRI is particularly attractive due to its high spatial resolution and because it does not involve ionising radiation. This paper reviews...... myocardial perfusion imaging with MR contrast agents: methods, validation and experiences from clinical studies. Unresolved issues still restrict the use of these techniques to research although clinical applications are within reach Udgivelsesdato: 2008/12/8...

  1. 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

  2. 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

  3. 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)

  4. Kinetics of tissue distribution and elimination of 4,4'-methylene bis(2-chloroaniline) in rats

    Energy Technology Data Exchange (ETDEWEB)

    Tobes, M.C.; Brown, L.E.; Chin, B.; Marsh, D.D. (Michigan Univ., Ann Arbor (USA). Medical Center)

    1983-06-01

    The tissue distribution kinetics and elimination of 4,4'-methylene bis(2-chloroaniline) (MBOCA) in rats was studied after a single dose of (/sup 14/C)MBOCA (0.49 mg/kg body weight, i.v.). The highest concentrations of radioactivity were in the small intestine, liver, adipose, lung, kidney, skin, and adrenals. For most tissues, a rapid decrease in radioactivity was followed by a slower decrease except for the small intestine, adipose and skin which demonstrated transient increases. Subcellular distribution in liver at 1 h showed radioactivity in all cell fractions. Although very lipophilic, (/sup 14/C)MBOCA was completely eliminated within 48 h with the major route via the feces (73.4%).

  5. Regional perfusion and oxygenation of tumors upon methylxanthine derivative administration

    International Nuclear Information System (INIS)

    Kelleher, Debra K.; Thews, Oliver; Vaupel, Peter

    1998-01-01

    Purpose: The use of methylxanthine derivatives has been postulated as a means of increasing tumor perfusion and thus ameliorating tumor hypoxia. The aim of this study was to quantify and compare the effects of three methylxanthine derivatives: pentoxifylline (PX), torbafylline (TB), and HWA 138 (HW) on tumor perfusion and oxygenation. Methods and Materials: Anesthetized Sprague Dawley rats with DS-sarcomas implanted subcutaneously onto the hind foot dorsum were used in this study. Mean arterial blood pressure (MABP) was measured throughout experiments. Regional red blood cell (RBC) flux was monitored using a multichannel laser Doppler device and tumor oxygenation on a more global level was assessed polarographically using an O 2 -sensitive catheter electrode. The methylxanthine derivatives were administered as a single dose intraperitoneally (for PX 50 mg/kg; for TB and HW 75 mg/kg). Results: Following drug administration, initial decreases in MABP down to 75% of baseline values were observed for all three substances. PX, HW, and TB caused initial transient reductions in mean RBC flux followed by gradual increases to values of 137 ± 27 %, 139 ± 14 %, and 122 ± 14 % respectively at t = 60 min. Following a small initial decrease upon drug administration, O 2 partial pressure (pO 2 ) rose to 160 ± 31 %, 153 ± 34 %, and 121 ± 11 % for PX, HW, and TB, respectively at t = 60 min. At the end of the observation period (t = 90 min), increases in RBC flux and pO 2 were still evident. When individual tumors were considered, a variety of patterns (including opposing effects) for changes in RBC flux were seen, not necessarily reflected in the mean values. Thus, while the methylxanthine derivatives caused an increased average tumor perfusion, there is evidence suggesting that a redistribution of tumor blood flow occurs which may amplify preexisting heterogeneity. Conclusions: Substantial improvements in tumor oxygenation and perfusion were observed after administration of

  6. 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.

  7. 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,

  8. 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.

  9. 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.)

  10. Finite-element simulation of blood perfusion in muscle tissue during compression and sustained contraction.

    Science.gov (United States)

    Vankan, W J; Huyghe, J M; Slaaf, D W; van Donkelaar, C C; Drost, M R; Janssen, J D; Huson, A

    1997-09-01

    Mechanical interaction between tissue stress and blood perfusion in skeletal muscles plays an important role in blood flow impediment during sustained contraction. The exact mechanism of this interaction is not clear, and experimental investigation of this mechanism is difficult. We developed a finite-element model of the mechanical behavior of blood-perfused muscle tissue, which accounts for mechanical blood-tissue interaction in maximally vasodilated vasculature. Verification of the model was performed by comparing finite-element results of blood pressure and flow with experimental measurements in a muscle that is subject to well-controlled mechanical loading conditions. In addition, we performed simulations of blood perfusion during tetanic, isometric contraction and maximal vasodilation in a simplified, two-dimensional finite-element model of a rat calf muscle. A vascular waterfall in the venous compartment was identified as the main cause for blood flow impediment both in the experiment and in the finite-element simulations. The validated finite-element model offers possibilities for detailed analysis of blood perfusion in three-dimensional muscle models under complicated loading conditions.

  11. Investigation of the mechanisms mediating MDMA "Ecstasy"-induced increases in cerebro-cortical perfusion determined by btASL MRI.

    Science.gov (United States)

    Rouine, J; Kelly, M E; Jennings-Murphy, C; Duffy, P; Gorman, I; Gormley, S; Kerskens, C M; Harkin, Andrew

    2015-05-01

    Acute administration of the recreational drug of abuse 3,4-methylenedioxymethamphetamine (MDMA; Ecstasy) has previously been shown to increase cerebro-cortical perfusion as determined by bolus-tracking arterial spin labelling (btASL) MRI. The purpose of the current study was to assess the mechanisms mediating these changes following systemic administration of MDMA to rats. Pharmacological manipulation of serotonergic, dopaminergic and nitrergic transmission was carried out to determine the mechanism of action of MDMA-induced increases in cortical perfusion using btASL MRI. Fenfluramine (10 mg/kg), like MDMA (20 mg/kg), increased cortical perfusion. Increased cortical perfusion was not obtained with the 5-HT2 receptor agonist 2,5-dimethoxy-4-iodophenyl-aminopropane hydrochloride (DOI) (1 mg/kg). Depletion of central 5-HT following systemic administration of the tryptophan hydroxylase inhibitor para-chlorophenylalanine (pCPA) produced effects similar to those observed with MDMA. Pre-treatment with the 5-HT receptor antagonist metergoline (4 mg/kg) or with the 5-HT reuptake inhibitor citalopram (30 mg/kg), however, failed to produce any effect alone or influence the response to MDMA. Pre-treatment with the dopamine D1 receptor antagonist SCH 23390 (1 mg/kg) failed to influence the changes in cortical perfusion obtained with MDMA. Treatment with the neuronal nitric oxide (NO) synthase inhibitor 7-nitroindazole (7-NI) (25 mg/kg) provoked no change in cerebral perfusion alone yet attenuated the MDMA-related increase in cortical perfusion. Cortical 5-HT depletion is associated with increases in perfusion although this mechanism alone does not account for MDMA-related changes. A role for NO, a key regulator of cerebrovascular perfusion, is implicated in MDMA-induced increases in cortical perfusion.

  12. [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.

  13. Myocardial perfusion imaging with dual energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Kwang Nam [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of); De Cecco, Carlo N. [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncology and Pathology, University of Rome “Sapienza”, Rome (Italy); Tesche, Christian [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich (Germany); Spandorfer, Adam; Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States)

    2016-10-15

    Highlights: • Stress dual-energy sCTMPI offers the possibility to directly detect the presence of myocardial perfusion defects. • Stress dual-energy sCTMPI allows differentiating between reversible and fixed myocardial perfusion defects. • The combination of coronary CT angiography and dual-energy sCTMPI can improve the ability of CT to detect hemodynamically relevant coronary artery disease. - Abstract: Dual-energy CT (DECT) enables simultaneous use of two different tube voltages, thus different x-ray absorption characteristics are acquired in the same anatomic location with two different X-ray spectra. The various DECT techniques allow material decomposition and mapping of the iodine distribution within the myocardium. Static dual-energy myocardial perfusion imaging (sCTMPI) using pharmacological stress agents demonstrate myocardial ischemia by single snapshot images of myocardial iodine distribution. sCTMPI gives incremental values to coronary artery stenosis detected on coronary CT angiography (CCTA) by showing consequent reversible or fixed myocardial perfusion defects. The comprehensive acquisition of CCTA and sCTMPI offers extensive morphological and functional evaluation of coronary artery disease. Recent studies have revealed that dual-energy sCTMPI shows promising diagnostic accuracy for the detection of hemodynamically significant coronary artery disease compared to single-photon emission computed tomography, invasive coronary angiography, and cardiac MRI. The aim of this review is to present currently available DECT techniques for static myocardial perfusion imaging and recent clinical applications and ongoing investigations.

  14. Biological characterization of F-18-labeled rhodamine B, a potential positron emission tomography perfusion tracer.

    Science.gov (United States)

    Bartholomä, Mark D; He, Huamei; Pacak, Christina A; Dunning, Patricia; Fahey, Frederic H; McGowan, Francis X; Cowan, Douglas B; Treves, S Ted; Packard, Alan B

    2013-11-01

    Myocardial infarction is the leading cause of death in western countries, and positron emission tomography (PET) plays an increasing role in the diagnosis and treatment planning for this disease. However, the absence of an (18)F-labeled PET myocardial perfusion tracer hampers the widespread use of PET in myocardial perfusion imaging (MPI). We recently reported a potential MPI agent based on (18)F-labeled rhodamine B. The goal of this study was to more completely define the biological properties of (18)F-labeled rhodamine B with respect to uptake and localization in an animal model of myocardial infarction and to evaluate the uptake (18)F-labeled rhodamine B by cardiomyocytes. A total of 12 female Sprague Dawley rats with a permanent ligation of the left anterior descending artery (LAD) were studied with small-animal PET. The animals were injected with 100-150 μCi of (18)F-labeled rhodamine B diethylene glycol ester ([(18)F]RhoBDEGF) and imaged two days before ligation. The animals were imaged again two to ten days post-ligation. After the post-surgery scans, the animals were euthanized and the hearts were sectioned into 1mm slices and myocardial infarct size was determined by phosphorimaging and 2,3,5-triphenyltetrazolium chloride staining (TTC). In addition, the uptake of [(18)F]RhoBDEGF in isolated rat neonatal cardiomyocytes was determined by fluorescence microscopy. Small-animal PET showed intense and uniform uptake of [(18)F]RhoBDEGF throughout the myocardium in healthy rats. After LAD ligation, well defined perfusion defects were observed in the PET images. The defect size was highly correlated with the infarct size as determined ex vivo by phosphorimaging and TTC staining. In vitro, [(18)F]RhoBDEGF was rapidly internalized into rat cardiomyocytes with ~40 % of the initial activity internalized within the 60 min incubation time. Fluorescence microscopy clearly demonstrated localization of [(18)F]RhoBDEGF in the mitochondria of rat cardiomyocytes. Fluorine-18

  15. Biological characterization of F-18-labeled rhodamine B, a potential positron emission tomography perfusion tracer

    International Nuclear Information System (INIS)

    Bartholomä, Mark D.; He, Huamei; Pacak, Christina A.; Dunning, Patricia; Fahey, Frederic H.; McGowan, Francis X.; Cowan, Douglas B.; Treves, S. Ted; Packard, Alan B.

    2013-01-01

    Introduction: Myocardial infarction is the leading cause of death in western countries, and positron emission tomography (PET) plays an increasing role in the diagnosis and treatment planning for this disease. However, the absence of an 18 F-labeled PET myocardial perfusion tracer hampers the widespread use of PET in myocardial perfusion imaging (MPI). We recently reported a potential MPI agent based on 18 F-labeled rhodamine B. The goal of this study was to more completely define the biological properties of 18 F-labeled rhodamine B with respect to uptake and localization in an animal model of myocardial infarction and to evaluate the uptake 18 F-labeled rhodamine B by cardiomyocytes. Methods: A total of 12 female Sprague Dawley rats with a permanent ligation of the left anterior descending artery (LAD) were studied with small-animal PET. The animals were injected with 100–150 μCi of 18 F-labeled rhodamine B diethylene glycol ester ([ 18 F]RhoBDEGF) and imaged two days before ligation. The animals were imaged again two to ten days post-ligation. After the post-surgery scans, the animals were euthanized and the hearts were sectioned into 1 mm slices and myocardial infarct size was determined by phosphorimaging and 2,3,5-triphenyltetrazolium chloride staining (TTC). In addition, the uptake of [ 18 F]RhoBDEGF in isolated rat neonatal cardiomyocytes was determined by fluorescence microscopy. Results: Small-animal PET showed intense and uniform uptake of [ 18 F]RhoBDEGF throughout the myocardium in healthy rats. After LAD ligation, well defined perfusion defects were observed in the PET images. The defect size was highly correlated with the infarct size as determined ex vivo by phosphorimaging and TTC staining. In vitro, [ 18 F]RhoBDEGF was rapidly internalized into rat cardiomyocytes with ∼ 40 % of the initial activity internalized within the 60 min incubation time. Fluorescence microscopy clearly demonstrated localization of [ 18 F]RhoBDEGF in the mitochondria

  16. 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

  17. [Attenuation of the efficacy of vasoconstrictive effects in rats after a 3-week suspension

    DEFF Research Database (Denmark)

    Matchkov, Vladimir; Tarasova, Olga S; Timin, Eugeny N

    1997-01-01

    Male Wistar rats were maintained suspended by the skin of posterior third of the back for three weeks. Constrictive reactions to norepinephrine and irritation of sympathetic nerves were studied with hindlimb vessels perfused with physiological solution at constant pressure. Perfusion pressure was...

  18. Dynamic perfusion patterns in temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Dupont, Patrick; Paesschen, Wim van; Zaknun, John J.; Maes, Alex; Tepmongkol, Supatporn; Locharernkul, Chaichon; Vasquez, Silvia; Carpintiero, Silvina; Bal, C.S.; Dondi, Maurizio

    2009-01-01

    To investigate dynamic ictal perfusion changes during temporal lobe epilepsy (TLE). We investigated 37 patients with TLE by ictal and interictal SPECT. All ictal injections were performed within 60 s of seizure onset. Statistical parametric mapping was used to analyse brain perfusion changes and temporal relationships with injection time and seizure duration as covariates. The analysis revealed significant ictal hyperperfusion in the ipsilateral temporal lobe extending to subcortical regions. Hypoperfusion was observed in large extratemporal areas. There were also significant dynamic changes in several extratemporal regions: ipsilateral orbitofrontal and bilateral superior frontal gyri and the contralateral cerebellum and ipsilateral striatum. The study demonstrated early dynamic perfusion changes in extratemporal regions probably involved in both propagation of epileptic activity and initiation of inhibitory mechanisms. (orig.)

  19. Dynamic perfusion patterns in temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Dupont, Patrick; Paesschen, Wim van [KU Leuven/UZ Gasthuisberg, Nuclear Medicine, Medical Imaging Center and Neurology, Leuven (Belgium); Zaknun, John J. [International Atomic Energy Agency (IAEA), Nuclear Medicine Section, Division of Human Health, Wagramer Strasse 5, PO BOX 200, Vienna (Austria); University Hospital of Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Maes, Alex [KU Leuven/UZ Gasthuisberg, Nuclear Medicine, Medical Imaging Center and Neurology, Leuven (Belgium); AZ Groeninge, Nuclear Medicine, Kortrijk (Belgium); Tepmongkol, Supatporn; Locharernkul, Chaichon [Chulalongkorn University, Nuclear Medicine and Neurology, Bangkok (Thailand); Vasquez, Silvia; Carpintiero, Silvina [Fleni Instituto de Investigaciones Neurologicas, Nuclear Medicine, Buenos Aires (Argentina); Bal, C.S. [All India Institute of Medical Sciences, Nuclear Medicine, New Delhi (India); Dondi, Maurizio [International Atomic Energy Agency (IAEA), Nuclear Medicine Section, Division of Human Health, Wagramer Strasse 5, PO BOX 200, Vienna (Austria); Ospedale Maggiore, Nuclear Medicine, Bologna (Italy)

    2009-05-15

    To investigate dynamic ictal perfusion changes during temporal lobe epilepsy (TLE). We investigated 37 patients with TLE by ictal and interictal SPECT. All ictal injections were performed within 60 s of seizure onset. Statistical parametric mapping was used to analyse brain perfusion changes and temporal relationships with injection time and seizure duration as covariates. The analysis revealed significant ictal hyperperfusion in the ipsilateral temporal lobe extending to subcortical regions. Hypoperfusion was observed in large extratemporal areas. There were also significant dynamic changes in several extratemporal regions: ipsilateral orbitofrontal and bilateral superior frontal gyri and the contralateral cerebellum and ipsilateral striatum. The study demonstrated early dynamic perfusion changes in extratemporal regions probably involved in both propagation of epileptic activity and initiation of inhibitory mechanisms. (orig.)

  20. Cardiac tissue engineering using perfusion bioreactor systems

    Science.gov (United States)

    Radisic, Milica; Marsano, Anna; Maidhof, Robert; Wang, Yadong; Vunjak-Novakovic, Gordana

    2009-01-01

    This protocol describes tissue engineering of synchronously contractile cardiac constructs by culturing cardiac cell populations on porous scaffolds (in some cases with an array of channels) and bioreactors with perfusion of culture medium (in some cases supplemented with an oxygen carrier). The overall approach is ‘biomimetic’ in nature as it tends to provide in vivo-like oxygen supply to cultured cells and thereby overcome inherent limitations of diffusional transport in conventional culture systems. In order to mimic the capillary network, cells are cultured on channeled elastomer scaffolds that are perfused with culture medium that can contain oxygen carriers. The overall protocol takes 2–4 weeks, including assembly of the perfusion systems, preparation of scaffolds, cell seeding and cultivation, and on-line and end-point assessment methods. This model is well suited for a wide range of cardiac tissue engineering applications, including the use of human stem cells, and high-fidelity models for biological research. PMID:18388955

  1. Optimization of perfusion studies using Atropine

    International Nuclear Information System (INIS)

    Alvarado, A.N.; Valle, V.M.; Montoya, M.J.; Eskenazi, E.S.; Montiel, M.L.; Cueto, C.C.

    2002-01-01

    The studies of myocardial perfusion require an adequate stress; exercise or pharmacological. Every day, more pharmacological studies are performed, specially in some group of patients (women, AMI, etc). There some drugs that are used for this purpose, as adenosine and dobutamine. However, their cost and the lack of availability and infrastructure in our country do not allow there routinely use. We performed dipyridamol as a pharmacological stress, however in some patients there is a doubt regarding if the pharmacological effect was adequate. Atropine is a drug that is frequently used for different purpose and it is well know its tachycardic response. We present and alternative technique, using dipyridamol-atropine as a protocol of stress perfusion study. Our goal was to correlate the standard dipyridamol -thallium perfusion study and the dipyridamol -atropine-perfusion in patients with chronic coronary disease. We evaluated 6 patients (5 males) with stable angina and chronic coronary disease. A standard dipyridamol-thallium study was performed in all of them. Dipyridamole was administered intravenously at a rate of 0.14 mg/kg/min over 6 min for a total of 0.84 mg/kg body weight. Blood pressure, heart rate, EKG and symptoms were monitored before, during and after the pharmacological infusion. Two minutes after the infusion was completed, the radiotracer was injected intravenously. In the next 6 months, without any modification of the clinical situation (symptoms and therapy) a new dipyridamol study was performed, using 1 mg of atropine after the administration of dipyridamol. There were no differences in the collateral effects and we observed and average increase of 30% in the heart rate in relation with the study using dipyridamol alone. The addition of atropine to the standard dipyridamol perfusion study is safe, cheaper and improved the detection of perfusion defects in patients with coronary artery disease

  2. Cerebral perfusion imaging in HIV positive patients

    International Nuclear Information System (INIS)

    Kundley, Kshama; Chowdhury, D.; Lele, V.R.; Lele, R.D.

    1998-01-01

    Full text: Twelve human immunodeficiency virus (HIV) positive patients were studied by SPECT cerebral perfusion imaging 1 hour post injection of 15 mCi of 99m Tc-ECD under ideal conditions with a triple head gamma camera (Prism 3000 X P LEUHR), fanbeam collimators followed by Folstein Mini Mental Status Examination (FMMSE) and AIDS dementia complex (ADC) staging on the same day. All 12 patients were male, in the age range of 23-45 y (mean 31 y). The infected status was diagnosed by ELISA (10 patients) or Western blot (5 patients). The interval between diagnosis and imaging ranged from 1 month - 35 months (mean 15.3 months). Two patients were alcoholic and 2 were smokers. None of them had CNS disorder clinically. ADC staging and FMMSE could be performed in 4 patients. Two patients were normal (stage 0) and 2 were subclinical (stage 0.5) on ADC staging. FMMSE revealed normal or near normal status (mean score 35; maximum score 36). Cerebral perfusion images were interpreted simultaneously by 3 observers blind towards history and examination using semi-quantitative and quantitative methods by consensus. It revealed multiple areas of hypoperfusion, viz. temporal (11 patients (91 %), parietal 10 patients (83%), frontal 9 patients (75%, pre and post central gyrus 7 patients (58%), occipital 6 patients (50%) cingulate gyrus and cerebellum 5 patients (41%) and thalamic in 2 patients (16%). Hyper perfusion in caudate nuclei was noted in 10 patients (83%). The study reveals presence of multiple perfusion abnormalities on cerebral perfusion imaging in HIV positive patients who have normal/near normal mental status suggesting precedence of perfusion abnormality over clinically apparent mental deficit

  3. 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

  4. 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.

  5. Meta-Analysis of Stress Myocardial Perfusion Imaging

    Science.gov (United States)

    2017-06-06

    Coronary Disease; Echocardiography; Fractional Flow Reserve, Myocardial; Hemodynamics; Humans; Magnetic Resonance Imaging; Myocardial Perfusion Imaging; Perfusion; Predictive Value of Tests; Single Photon Emission Computed Tomography; Positron Emission Tomography; Multidetector Computed Tomography; Echocardiography, Stress; Coronary Angiography

  6. 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.

  7. FROG INTESTINAL PERFUSION TO EVALUATE DRUG PERMEABILITY: APPLICATION TO P-gp AND CYP3A4 SUBSTRATES

    Directory of Open Access Journals (Sweden)

    Neelima eYerasi

    2015-07-01

    Full Text Available AbstractTo evaluate the reliability of using in situ frog intestinal perfusion technique for permeability assessment of carrier transported drugs which are also substrates for CYP enzymes. Single Pass Intestinal Perfusion (SPIP studies were performed in frogs of the species Rana tigrina using established method for rats with some modifications after inducing anesthesia. Effective permeability coefficient (Peff of losartan and midazolam was calculated in the presence and absence of inhibitors using the parallel-tube model. Peff of losartan when perfused alone was found to be 0.427 ± 0.27×10-4cm/s and when it was co-perfused with inhibitors, significant change in Peff was observed. Peff of midazolam when perfused alone was found to be 2.03 ± 0.07 × 10-4cm/s and when it was co-perfused with inhibitors, no significant change in Peff was observed. Comparison of Peff calculated in frog with that of other available models and also humans suggested that the Peff values are comparable and reflected well with human intestinal permeability. It is possible to determine the Peff value for compounds which are dual substrates of P-gp and CYP3A4 using in situ frog intestinal perfusion technique. The calculated Peff values correlated well with reported Peff values of probe drugs. comparison of the Peff value of losartan obtained with that of reported human’s Peff and Caco 2 cell data, and comparison of the Peff value of midazolam with that of reported rat’s Peff, we could conclude that SPIP from model can be reliably used in preclinical studies for permeability estimation. This model may represent a valuable alternative to the low speed and high cost of conventional animal models (typically rodents for the assessment of intestinal permeability.

  8. CT perfusion for determination of pharmacologically mediated blood flow changes in an animal tumor model.

    Science.gov (United States)

    Hakimé, Antoine; Peddi, Himaja; Hines-Peralta, Andrew U; Wilcox, Carol J; Kruskal, Jonathan; Lin, Shezhang; de Baere, Thierry; Raptopoulos, Vassilios D; Goldberg, S Nahum

    2007-06-01

    To prospectively compare single- and multisection computed tomographic (CT) perfusion for tumor blood flow determination in an animal model. All animal protocols and experiments were approved by the institutional animal care and use committee before the study was initiated. R3230 mammary adenocarcinoma was implanted in 11 rats. Tumors (18-20 mm) were scanned with dynamic 16-section CT at baseline and after administration of arsenic trioxide, which is known to cause acute reduction in blood flow. The concentration of arsenic was titrated (0-6 mg of arsenic per kilogram of body weight) to achieve a defined blood flow reduction (0%-75%) from baseline levels at 60 minutes, as determined with correlative laser Doppler flowmetry. The mean blood flow was calculated for each of four 5-mm sections that covered the entire tumor, as well as for the entire tumor after multiple sections were processed. Measurements obtained with both methods were correlated with laser Doppler flowmetry measurements. Interobserver agreement was determined for two blinded radiologists, who calculated the percentage of blood flow reduction for the "most representative" single sections at baseline and after arsenic administration. These results were compared with the interobserver variability of the same radiologists obtained by summing blood flow changes for the entire tumor volume. Overall correlations for acute blood flow reduction were demonstrated between laser Doppler flowmetry and the two CT perfusion approaches (single-section CT, r=0.85 and r(2)=0.73; multisection CT, r=0.93 and r(2)=0.87; pooled data, P=.01). CT perfusion disclosed marked heterogeneity of blood flow, with variations of 36% +/- 13 between adjacent 5-mm sections. Given these marked differences, interobserver agreement was much lower for single-section CT (standard deviation, 0.22) than for multisection CT (standard deviation, 0.10; P=.01). Multisection CT perfusion techniques may provide an accurate and more reproducible

  9. Automatic Detection of Myocardial Boundaries in MR Cardio Perfusion Images

    NARCIS (Netherlands)

    Spreeuwers, Luuk; Breeuwer, Marcel

    2001-01-01

    Cardiovascular diseases often result in reduced blood perfusion of the myocardium (MC). Recent advances in MR allow fast recordingof contrast enhanced myocardial perfusion scans. For perfusion analysis the myocardial boundaries must be traced. Currently this is done manually. In this paper a method

  10. Study of lung perfusion in colagenosis

    International Nuclear Information System (INIS)

    Macedo de Carvalho, A.C.; Calegaro, J.U.M.

    1982-01-01

    The lung involvement in the various types of colagenosis has been widely described in the literature. However, the study of lung perfusion utilizing radionuclides has been only mentioned in a few papers. With the intention of ascertaining the importance of the lung perfusion scanning in colagenosis, ten cases were studied, seven of which were females and three males, with the following pathologies: 4 rheumatoid arthritis, 4 systemic lupus eritematosous, 1 scleroderma and 1 scleroderma plus dermatomyositis. The ages of the patients varied from 20 to 73 years, and the duration of the disease from 1 month to 39 years. The lung scanning showed perfusion defects in 100% of the cases, not related with the type of colagenosis, duration of the disease, sex or age. On the other hand, the X rays study showed alterations in only 2 patients (20% of the cases). The ventilatory and respiratory functions were tested on 7 patients showing alteration (mixed pattern with predominance of the restrictive factor) in only one (14.3%), while the other patients were normal (85.7%). The importance of the lung perfusion scanning study in all patients with collagen vascular diseases is emphasized. (author) [es

  11. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo

    2010-01-01

    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 ov...

  12. Study of lung perfusion in colagenosis

    Energy Technology Data Exchange (ETDEWEB)

    Macedo de Carvalho, A C; Calegaro, J U.M. [Fundacao Hospitalar do Distrito Federal, Distrito Federal (Brazil). Unidade de Medicina Nuclear

    1982-07-01

    The lung involvement in the various types of colagenosis has been widely described in the literature. However, the study of lung perfusion utilizing radionuclides has been only mentioned in a few papers. With the intention of ascertaining the importance of the lung perfusion scanning in colagenosis, ten cases were studied, seven of which were females and three males, with the following pathologies: 4 rheumatoid arthritis, 4 systemic lupus eritematosous, 1 scleroderma and 1 scleroderma plus dermatomyositis. The ages of the patients varied from 20 to 73 years, and the duration of the disease from 1 month to 39 years. The lung scanning showed perfusion defects in 100% of the cases, not related with the type of colagenosis, duration of the disease, sex or age. On the other hand, the X rays study showed alterations in only 2 patients (20% of the cases). The ventilatory and respiratory functions were tested on 7 patients showing alteration (mixed pattern with predominance of the restrictive factor) in only one (14.3%), while the other patients were normal (85.7%). The importance of the lung perfusion scanning study in all patients with collagen vascular diseases is emphasized.

  13. Acid perfusion test in gastroesophageal reflux disease

    Energy Technology Data Exchange (ETDEWEB)

    Kaul, B.; Petersen, H.; Grette, K.; Myrvold, H.E.

    1986-01-01

    An acid perfusion test, isotope scanning, endoscopy, and esophageal biopsy were performed in 101 patients with symptoms strongly suggestive of gastroesophageal reflux (GER) disease. A positive acid perfusion test within 30 min (APT) and within 5 min (TAPT) was found in 70.2% and 37.6% of the patients, respectively. A positive APT was found significantly more often in patients with than without endoscopic esophagitis, whereas a positive TAPT was found significantly more often in patients with severe symptoms than in patients with moderate symptoms, and in a significantly higher proportion of patients with than without GER by scintigraphy. Neither the APT nor the TAPT showed any dependency on the presence of histologic esophagitis. Most (97%) patients with a negative acid perfusion test, in addition to typical symptoms, also presented with scintigraphic, endoscopic, or histologic evidence of GER disease. Although it shows that the acid perfusion test, particularly when early positive, may serve as a weak predictor of the severity of GER disease, the present study gives little support to the test's clinical usefulness.

  14. Nuclear cardiology: Myocardial perfusion and function

    International Nuclear Information System (INIS)

    Seldin, D.W.

    1991-01-01

    Myocardial perfusion studies continue to be a major focus of research, with new investigations of the relationship of exercise-redistribution thallium imaging to diagnosis, prognosis, and case management. The redistribution phenomenon, which seemed to be fairly well understood a few years ago, is now recognized to be much more complex than originally thought, and various strategies have been proposed to clarify the meaning of persistent defects. Pharmacologic intervention with dipyridamole and adenosine has become available as an alternative to exercise, and comparisons with exercise imaging and catheterization results have been described. Thallium itself is no longer the sole single-photon perfusion radiopharmaceutical; two new technetium agents are now widely available. In addition to perfusion studies, advances in the study of ventricular function have been made, including reports of studies performed in conjunction with technetium perfusion studies, new insights into cardiac physiology, and the prognostic and case-management information that function studies provide. Finally, work has continued with monoclonal antibodies for the identification of areas of myocyte necrosis. 41 references

  15. Perfusion Quantification Using Gaussian Process Deconvolution

    DEFF Research Database (Denmark)

    Andersen, Irene Klærke; Have, Anna Szynkowiak; Rasmussen, Carl Edward

    2002-01-01

    The quantification of perfusion using dynamic susceptibility contrast MRI (DSC-MRI) requires deconvolution to obtain the residual impulse response function (IRF). In this work, a method using the Gaussian process for deconvolution (GPD) is proposed. The fact that the IRF is smooth is incorporated...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  17. Detectable perfusion changes in MAG3 studies

    International Nuclear Information System (INIS)

    Shuter, B.; Bernar, A.; Roach, P.

    1998-01-01

    Full text: The use of 120 MBq 99m Tc-MAG 3 instead of 600 MBq 99m Tc-DTPA in renal imaging has degraded the images obtained during the perfusion phase. An increase of the minimum detectable change (MDC) in blood flow (BF) would also be expected. In transplant patients, renal BF is an important factor in patient management and the MDC should be small to allow early detection of reduced perfusion. We determined the mean and coefficient of variation (CoV: standard deviation/mean) of three renal perfusion indices as a function of counts in the time-activity curves (TACs). Transplant patients were given a dose of about 300 MBq of 99m Tc-MAG3 and images acquired at 8 fps for 60s. TACs made up from 8, 4, 2 or I images per second allowed calculation of renal perfusion indices as if doses of 300, 150, 75 and 38 MBq had been administered. Perfusion indices based on area under the TACs up to the arterial peak (API), the maximum slopes of the TACs (SPI) and the maximum slope of renal TAC and height of arterial TAC (BPI) were calculated by our routine renal software package. As the administered dose decreased, the CoV rose for all indices, least for BPI and most for API. BPI CoV increased from ∼10% at 300 MBq to 20% at 75 MBq, but API CoV rose from 6% to 46%. Mean BPI was stable over the dose range, but mean API showed a systematic increase of about 50% over the 300 MBq result. We conclude that at 120 MBq the MDC (expressed as 2*CoV) in BF is 30-60%, whereas at 600 MBq it may be as low as 10%, allowing earlier confident detection of a change in BF. The BPI was the preferred perfusion index as its mean value changed little and it had the least CoV at lower activities. The data also imply that relative kidney perfusion in the one individual will be much less accurate with 120 MBq of MAG 3

  18. 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...

  19. Myocardial perfusion imaging by digital subtraction angiography

    International Nuclear Information System (INIS)

    Kadowaki, Hiroyuki; Ishikawa, Kinji; Ogai, Toshihiro; Katori, Ryo

    1986-01-01

    Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; 1) at the R wave of the electrocardiogram, 2) 100 msec before the R wave, and 3) 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery. In all patients with anterior myocardial infarction, low perfusion was observed at the infarcted portion compared to the non-infarcted myocardium. In patients with inferior myocardial infarction, this low perfusion area was not observed because right coronary angiography was not subjected to DSA in this study. (J.P.N.)

  20. Basic consideration of diffusion/perfusion imaging

    International Nuclear Information System (INIS)

    Tamagawa, Yoichi; Kimura, Hirohiko; Matsuda, Tsuyoshi; Kawamura, Yasutaka; Nakatsugawa, Shigekazu; Ishii, Yasushi; Sakuma, Hajime; Tsukamoto, Tetsuji.

    1990-01-01

    In magnetic resonance imaging (MRI), microscopic motion of biological system such as molecular diffusion of water and microcirculation of blood in the capillary network (perfusion) has been proposed to cause signal attenuation as an intravoxel incoherent motion (IVIM). Quantitative imaging of the IVIM phenomenon was attempted to generate from a set of spin-echo (SE) sequences with or without sensitization by motion probing gradient (MPG). The IVIM imaging is characterized by a parameter, apparent diffusion coefficient (ADC), which is an integration of both the diffusion and the perfusion factor on voxel-by-voxel basis. Hard ware was adjusted to avoid image artifact mainly produced by eddy current. Feasibility of the method was tested using bottle phantom filled with water at different temperature and acetone, and the calculated ADC values of these media corresponded well with accepted values of diffusion. The method was then applied to biological system to investigate mutual participation of diffusion/perfusion on the ADC value. The result of tumor model born on nude mouse suggested considerable participation of perfusion factor which immediately disappeared after sacrificing the animal. Meanwhile, lower value of sacrificed tissue without microcirculation was suggested to have some restriction of diffusion factor by biological tissue. To substantiate the restriction effect on the diffusion, a series of observation have made on a fiber phantom, stalk of celory with botanical fibers and human brain with nerve fibers, in applying unidirectional MPG along the course of these banch of fiber system. The directional restriction effect of diffusion along the course of fiber (diffusion anisotrophy) was clearly visualized as directional change of ADC value. The present method for tissue characterization by diffusion/perfusion on microscopic level will provide a new insight for evaluation of functional derangement in human brain and other organs. (author)

  1. Ventilation-perfusion distribution in normal subjects.

    Science.gov (United States)

    Beck, Kenneth C; Johnson, Bruce D; Olson, Thomas P; Wilson, Theodore A

    2012-09-01

    Functional values of LogSD of the ventilation distribution (σ(V)) have been reported previously, but functional values of LogSD of the perfusion distribution (σ(q)) and the coefficient of correlation between ventilation and perfusion (ρ) have not been measured in humans. Here, we report values for σ(V), σ(q), and ρ obtained from wash-in data for three gases, helium and two soluble gases, acetylene and dimethyl ether. Normal subjects inspired gas containing the test gases, and the concentrations of the gases at end-expiration during the first 10 breaths were measured with the subjects at rest and at increasing levels of exercise. The regional distribution of ventilation and perfusion was described by a bivariate log-normal distribution with parameters σ(V), σ(q), and ρ, and these parameters were evaluated by matching the values of expired gas concentrations calculated for this distribution to the measured values. Values of cardiac output and LogSD ventilation/perfusion (Va/Q) were obtained. At rest, σ(q) is high (1.08 ± 0.12). With the onset of ventilation, σ(q) decreases to 0.85 ± 0.09 but remains higher than σ(V) (0.43 ± 0.09) at all exercise levels. Rho increases to 0.87 ± 0.07, and the value of LogSD Va/Q for light and moderate exercise is primarily the result of the difference between the magnitudes of σ(q) and σ(V). With known values for the parameters, the bivariate distribution describes the comprehensive distribution of ventilation and perfusion that underlies the distribution of the Va/Q ratio.

  2. Evaluation of a pyridoxylated hemoglobin polyoxyethylene conjugate solution as a perfusate for small intestine preservation.

    Science.gov (United States)

    Liu, H; Agishi, T; Kawai, T; Hayashi, T; Fujita, S; Fuchinoue, S; Takahashi, K; Teraoka, S; Ota, K

    1992-01-01

    A new type of artificial blood, pyridoxylated hemoglobin-polyoxyethylene conjugate (PHP) solution, (developed by PHP research group of the department of health and welfare of Japan, and produced by Ajinomoto Co., Inc. Tokyo) as an oxygen-carrying component, has been recently devised using hemoglobin obtained from hemolyzed human erythrocytes. Recently, the studies using this solution as a preservation solution were performed in some instances. To examine the mechanism of improved viability using this solution as a preservation solution, we developed a model of orthotopic small intestine transplantation (OIT) in the rat. As a baseline study, we compared parameters of viability of the grafts preserved in Collins and UW solution to those preserved in PHP solution including a survival rate, a serum level total protein and albumin, and a change in body weight after transplantation. In our study, the simple hypothermia storage together with intestinal perfusion preservation with PHP solution was performed. Animals were divided into 6, 12, and 24 hr preservation groups. All of the rats survived after 6 hr preservation following transplantation. However, in 12 hr storage, five of six rats in PHP solution preservation survived and recovery in body weight after grafting was better than those with Collins and UW solution. We conclude that the PHP solution is, therefore, considered to possibly be a more suitable perfusate for small intestine preservation than Collins and UW solution.

  3. 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.)

  4. 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

  5. Compact Laser Doppler Flowmeter (LDF Fundus Camera for the Assessment of Retinal Blood Perfusion in Small Animals.

    Directory of Open Access Journals (Sweden)

    Marielle Mentek

    Full Text Available Noninvasive techniques for ocular blood perfusion assessment are of crucial importance for exploring microvascular alterations related to systemic and ocular diseases. However, few techniques adapted to rodents are available and most are invasive or not specifically focused on the optic nerve head (ONH, choroid or retinal circulation. Here we present the results obtained with a new rodent-adapted compact fundus camera based on laser Doppler flowmetry (LDF.A confocal miniature flowmeter was fixed to a specially designed 3D rotating mechanical arm and adjusted on a rodent stereotaxic table in order to accurately point the laser beam at the retinal region of interest. The linearity of the LDF measurements was assessed using a rotating Teflon wheel and a flow of microspheres in a glass capillary. In vivo reproducibility was assessed in Wistar rats with repeated measurements (inter-session and inter-day of retinal arteries and ONH blood velocity in six and ten rats, respectively. These parameters were also recorded during an acute intraocular pressure increase to 150 mmHg and after heart arrest (n = 5 rats.The perfusion measurements showed perfect linearity between LDF velocity and Teflon wheel or microsphere speed. Intraclass correlation coefficients for retinal arteries and ONH velocity (0.82 and 0.86, respectively indicated strong inter-session repeatability and stability. Inter-day reproducibility was good (0.79 and 0.7, respectively. Upon ocular blood flow cessation, the retinal artery velocity signal substantially decreased, whereas the ONH signal did not significantly vary, suggesting that it could mostly be attributed to tissue light scattering.We have demonstrated that, while not adapted for ONH blood perfusion assessment, this device allows pertinent, stable and repeatable measurements of retinal blood perfusion in rats.

  6. Pulmonary ventilation and perfusion abnormalities and ventilation perfusion imbalance in children with pulmonary atresia or extreme tetralogy of Fallot

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. 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

  8. The characterization and metabolism of rat hepatic nascent HLD subfractions

    International Nuclear Information System (INIS)

    Winkler, K.E.

    1988-01-01

    Nascent HDL was isolated from recirculating rat liver perfusates and separated by heparin-sepharose chromatography into a non-retained fraction (A) and a fraction (B) that eluted with 0.5 M NaCl. Fractions A and B contained 70% and 30% of the nascent HDL protein, respectively. Livers perfused by the single-pass technique produced fractions A and B in the same ratio as livers perfused by recirculation. The apolipoprotein compositions were similar to those in the recirculating perfusion; however, both fractions A and B had more triglyceride (greater than 50% of total lipid). In a preliminary study designed to investigate whether nascent HDL-apo E was secreted by Kupffer cells or hepatocytes, label was targeted to Kupffer cells by perfusing rat livers with 3 H-acetylated LDL or 3 H-amino acids incorporated into large multilamellar vesicles. For metabolic studies, nascent HDL and nascent VLDL were isolated from rat livers that had been perfused with 3 H-glycerol to label the triglyceride

  9. 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.)

  10. 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...

  11. Patient satisfaction with coronary CT angiography, myocardial CT perfusion, myocardial perfusion MRI, SPECT myocardial perfusion imaging and conventional coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Feger, S.; Rief, M.; Zimmermann, E.; Richter, F.; Roehle, R. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Dewey, M. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Institut fuer Radiologie, Berlin (Germany); Schoenenberger, E. [Medizinische Hochschule Hannover, Department of Medicine, Hannover (Germany)

    2015-07-15

    To evaluate patient acceptance of noninvasive imaging tests for detection of coronary artery disease (CAD), including single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI), stress perfusion magnetic resonance imaging (MRI), coronary CT angiography (CTA) in combination with CT myocardial stress perfusion (CTP), and conventional coronary angiography (CCA). Intraindividual comparison of perception of 48 patients from the CORE320 multicentre multinational study who underwent rest and stress SPECT-MPI with a technetium-based tracer, combined CTA and CTP (both with contrast agent, CTP with adenosine), MRI, and CCA. The analysis was performed by using a validated questionnaire. Patients had significantly more concern prior to CCA than before CTA/CTP (p < 0.001). CTA/CTP was also rated as more comfortable than SPECT-MPI (p = 0.001). Overall satisfaction with CT was superior to that of MRI (p = 0.007). More patients preferred CT (46 %; p < 0.001) as a future diagnostic test. Regarding combined CTA/CTP, CTP was characterised by higher pain levels and an increased frequency of angina pectoris during the examination (p < 0.001). Subgroup analysis showed a higher degree of pain during SPECT-MPI with adenosine stress compared to physical exercise (p = 0.016). All noninvasive cardiac imaging tests are well accepted by patients, with CT being the preferred examination. (orig.)

  12. Correlation of Perfusion MRI and 18F-FDG PET Imaging Biomarkers for Monitoring Regorafenib Therapy in Experimental Colon Carcinomas with Immunohistochemical Validation

    Science.gov (United States)

    Eschbach, Ralf S.; Fendler, Wolfgang P.; Kazmierczak, Philipp M.; Hacker, Marcus; Rominger, Axel; Carlsen, Janette; Hirner-Eppeneder, Heidrun; Schuster, Jessica; Moser, Matthias; Havla, Lukas; Schneider, Moritz J.; Ingrisch, Michael; Spaeth, Lukas; Reiser, Maximilian F.; Nikolaou, Konstantin; Cyran, Clemens C.

    2015-01-01

    Objectives To investigate a multimodal, multiparametric perfusion MRI / 18F-fluoro-deoxyglucose-(18F-FDG)-PET imaging protocol for monitoring regorafenib therapy effects on experimental colorectal adenocarcinomas in rats with immunohistochemical validation. Materials and Methods Human colorectal adenocarcinoma xenografts (HT-29) were implanted subcutaneously in n = 17 (n = 10 therapy group; n = 7 control group) female athymic nude rats (Hsd:RH-Foxn1rnu). Animals were imaged at baseline and after a one-week daily treatment protocol with regorafenib (10 mg/kg bodyweight) using a multimodal, multiparametric perfusion MRI/18F-FDG-PET imaging protocol. In perfusion MRI, quantitative parameters of plasma flow (PF, mL/100 mL/min), plasma volume (PV, %) and endothelial permeability-surface area product (PS, mL/100 mL/min) were calculated. In 18F-FDG-PET, tumor-to-background-ratio (TTB) was calculated. Perfusion MRI parameters were correlated with TTB and immunohistochemical assessments of tumor microvascular density (CD-31) and cell proliferation (Ki-67). Results Regorafenib significantly (pregorafenib therapy effects on experimental colorectal adenocarcinomas in vivo with significant correlations between perfusion MRI parameters and 18F-FDG-PET validated by immunohistochemistry. PMID:25668193

  13. Quantitative aspects of myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Vogel, R.A.

    1980-01-01

    Myocardial perfusion measurements have traditionally been performed in a quantitative fashion using application of the Sapirstein, Fick, Kety-Schmidt, or compartmental analysis principles. Although global myocardial blood flow measurements have not proven clinically useful, regional determinations have substantially advanced our understanding of and ability to detect myocardial ischemia. With the introduction of thallium-201, such studies have become widely available, although these have generally undergone qualitative evaluation. Using computer-digitized data, several methods for the quantification of myocardial perfusion images have been introduced. These include orthogonal and polar coordinate systems and anatomically oriented region of interest segmentation. Statistical ranges of normal and time-activity analyses have been applied to these data, resulting in objective and reproducible means of data evaluation

  14. Nursing implications for Hepatic arterial perfusion scintigraphy

    International Nuclear Information System (INIS)

    Ellender, R.

    1999-01-01

    Nurses working in Nuclear Medicine assist in Hepatic Artery Catheter (HAC) perfusion studies. This scan is not widely performed in Australia, the St George hospital for example performs approximately five per year. The purpose of this article is firstly to review the indications and rationale of HAC patency studies. Secondly, this article will stress the clinical implications for the Nuclear Medicine Nurse during this study. Emphasis will be placed on the importance of patient education during the procedure. A brief overview of hepatic anatomy and the radiopharmaceuticals administered during the scan is discussed. Finally, a step by step protocol is presented to show how the perfusion/ shunt study is performed. Copyright (1999) The Australian and New Zealand Society of Nuclear Medicine Inc

  15. Perfusion lung scintigraphy in primary pulmonary hypertension

    International Nuclear Information System (INIS)

    Ogawa, Y.; Hayashida, K.; Uehara, T.; Shimonagata, T.; Nishimura, T.; Osaka Univ., Suita

    1993-01-01

    15 cases of primary pulmonary hypertension were classified into two groups by patterns of perfusion lung scintigraphy. Perfusion scintigrams showed multiple, small, ill-defined defects (mottled + ve) pattern in eight cases, and the remaining seven cases had a normal (mottled - ve) pattern. The mean pulmonary arterial pressure in patients with a mottled pattern (54 ± 10 mmHg) was higher than in those with a normal pattern (42 ± 9 mmHg, p < 0.05). There were no significant differences between the two groups in right ventricular ejection fraction, partial pressures of oxygen in the arterial blood or alveolo-arterial oxygen difference. All the patients with a mottled pattern died within 2 years following the lung scintigraphy. There was a significant difference in the survival curves between the two groups. (author)

  16. Perfusion lung scintigraphy in primary pulmonary hypertension

    International Nuclear Information System (INIS)

    Ogawa, Yoji; Nishimura, Tsunehiko; Kumita, Shin-ichirou; Hayashida, Kohei; Uehara, Toshiisa; Shimonagata, Tsuyoshi; Ohno, Akira

    1991-01-01

    Fifteen cases with primary pulmonary hypertension (PPH) were classified into two groups by using the perfusion lung scan pattern. Eight cases had multiple, small, ill-defined defects (mottled pattern), and remaining seven cases had no mottled pattern. These two groups were compared with mean pulmonary arterial pressure (mean PAP), right ventricular ejection fraction (RVEF), blood gas at room air (PaO 2 ), and alveolar-arterial O 2 difference (A-aDo 2 ). The cases with mottled pattern showed a significant increase in mean PAP. There were no significant differences in RVEF, PaO 2 , and A-aDo 2 , between the groups. The survival rate of the patients with mottled pattern was significantly lower than that without mottled pattern (p<0.05). We concluded that perfusion lung scan is very useful for evaluation of the prognosis in primary pulmonary hypertension. (author)

  17. Comparative metabolism and elimination of acetanilide compounds by rat.

    Science.gov (United States)

    Davison, K L; Larsen, G L; Feil, V J

    1994-10-01

    1. 14C-labelled propachlor, alachlor, butachlor, metolachlor, methoxypropachlor and some of their mercapturic acid pathway metabolites (MAP) were given to rat either by gavage or by perfusion into a renal artery. MAP metabolites were isolated from bile and urine. 2. Rat gavaged with propachlor and methoxypropachlor eliminated 14C mostly in urine, whereas rat gavaged with alachlor, butachlor and metolachlor eliminated 14C about equally divided between urine and faeces. When bile ducts were cannulated, the gavaged rat eliminated most of the 14C in bile for all compounds. The amount of 14C in bile from the propachlor-gavaged rat was less than that for the other acetanilides, with the difference being in the urine. 3. The mercapturic acid metabolites 2-methylsulphinyl-N-(1-methylhydroxyethyl)-N-phenylacetam ide and 2-methylsulphinyl-N-(1-methylmethoxyethyl)-N-phenylacetam ide were isolated from the urine and bile of the methoxypropachlor-gavaged rat. 4. Bile was the major route for 14C elimination when MAP metabolites of alachlor, butachlor and metolachlor were perfused into a renal artery. Urine was the major route for 14C elimination when MAP metabolites of propachlor and methoxypropachlor were perfused. Mercapturic acid conjugates were major metabolites in bile and urine when MAP metabolites were perfused. 5. We conclude that alkyl groups on the phenyl portion of the acetanilide causes biliary elimination to be favoured over urinary elimination.

  18. Cerebral perfution studies; Estudios de Perfusion Cerebral

    Energy Technology Data Exchange (ETDEWEB)

    Mut, Fernando [Universidad de la Republica, Montevideo (Uruguay). Centro de Medicina Nuclear

    1994-12-31

    For detecting in precocious form a coronary disease is necessary to aply a diagnostic techniques. The main considerations to be indicated in the present work are: physiological considerations, myocardial perfusion studies with radiotracers such as Talio 201, 99mTc, MIBI, 99mTc-Teboroxima, 99mTc-Fosfinas, instrumentation for obtain good images, proceedings protocols, studies interpretation, standards, SPECT, anomalies standards, coronary diseases.

  19. Myocardial perfusion imaging in hyperthrophic cardiomyopathy

    International Nuclear Information System (INIS)

    Moorin, B.

    1998-01-01

    Full text: Patients with Hyperthrophic Cardiomyopathy (HCM) frequently suffer from syncope and cardiac arrest which may lead to sudden death. This is most often caused by ventricular arrhythmia's in adults, however in young patients the mechanisms are thought to be different. Ischaemia may play a significant role even in young asymptomatic HCM patients. The mechanisms of ischaemic development in HCM differ from those in the 'normal' myocardium (Due to intramural small vessel abnormalities and abnormal myocellular architecture). In HCM the coronary microcirculation is most often affected and massive hypertrophy means more energy is required to promote contraction thus increasing oxygen demand and compounding the effects of any ischaemic changes. A case of a 12 year old HCM patient is presented who has symptoms of syncope associated with exercise whose mother died suddenly of cardiac arrest developed from HCM. A myocardial perfusion rest/stress study was undertaken to detect any underlying myocardial ischaemia. Myocardial perfusion scintigraphy demonstrates any reduction in the microcirculation in addition to that present in the macrocirculation, unlike angiography which will only detect the latter. In this case the scan clearly showed evidence of ischaemia in the lateral wall and this may be an explanation for her episodes of syncope. We suggest an algorithm or the routine work-up of young patients with HCM which makes aggressive use of myocardial perfusion imaging to detect ischaemic changes. This may identify patients who are at higher risk and will assist with treatment decisions. We feel myocardial perfusion scintigraphy is a sensitive non-invasive accurate method of detecting microcirculatory ischaemia and is thus invaluable in HCM patients

  20. Regional cerebral perfusion in cardiovascular reflex syncope

    International Nuclear Information System (INIS)

    Toeyry, J.P.; Kuikka, J.T.; Laensimies, E.A.

    1997-01-01

    Little is known about the regional cerebral perfusion in subjects with presyncope or syncope, and the impact that autonomic nervous dysfunction has on it. Seven subjects with cardiovascular vasodepressor reflex syncope were studied. A baseline test was performed with the patients standing in the 70 upright position, while the passive head-up tilt table test with and without isoprenaline infusion was employed for provocation. Regional cerebral perfusion was assessed by means of single-photon emission tomography with technetium-99m labelled V-oxo-1,2-N,N 1 -ethylenedylbis-l-cysteine diethylester (baseline, and during blood pressure decline in the provocation test) and the autonomic nervous function by means of spectral analysis of heart rate variability (baseline, and before blood pressure decline in the provocation test). Every subject showed an abrupt decline in blood pressure in the provocation test (five with presyncope and two with syncope). The systolic and diastolic blood pressures decreased significantly (P<0.001) between the baseline and the provocation study time points (radiopharmaceutical injection and lowest systolic blood pressure). Mean cerebral perfusion as average count densities decreased upon provocation as compared with baseline (190±63 vs 307±90 counts/voxel, respectively, P=0.013). Hypoperfusion was most pronounced in the frontal lobe. These results suggest that cerebral perfusion decreases markedly during presyncope or syncope with systemic blood pressure decline in subjects with cardiovascular vasodepressor syncope. Furthermore, the autonomic nervous function remains unchanged before the systemic blood pressure decline. (orig.). With 3 figs., 2 tabs

  1. Myocardial perfusion studies in coronary diseases

    International Nuclear Information System (INIS)

    Mut, Fernando

    1994-01-01

    For detecting in precocious form a coronary disease is necessary to apply a diagnostic techniques. The main considerations to be indicated in the present work are: physiological considerations, myocardial perfusion studies with radiotracers such as Talio 201, 99mTc, MIBI, 99mTc-Teboroxima, 99mTc-Fosfinas, instrumentation for obtain good images,proceedings protocols, studies interpretation, standards, SPECT, anomalies standards, coronary diseases

  2. Non-contrast MRI perfusion angiosome in diabetic feet

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  3. 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.)

  4. 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

  5. Can perfusion SPECT aid CTPA interpretation?

    International Nuclear Information System (INIS)

    Gradinscak, D. J.; Roach, P.; Bailey, E.; Kueh, S.

    2009-01-01

    Full text:Objective: To determine whether fusion of perfusion SPECT and CTPA improves the diagnostic accuracy of CTPA. Methods: 35 patients with suspected PE who underwent both CTPA and SPECT V/Q within 48 hours were included. Of these, the majority (n=30) had PE as determined by the V/Q SPECT scan and the others (n=5) were negative for PE. The clinical reports of CTPA were reviewed and pulmonary emboli tabulated based on anatomical location. A second radiologist, blinded to the results of the clinical read and the V/Q SPECT scan, reviewed the CTPA with and without perfusion SPECT fusion for assistance. Results: A total 57 PE were reported on the clinical reports and 60 PE identified on the blinded read. Fused CTPA/perfursion SPECT images identified a further 5 PE not identified on the clinical read (8% increase) and 2 PE not identified on the blinded read (3% increase). The additional emboli detected resulted in a change in final diagnosis from PE negative to PE positive in 2 patients (6%) compared with the clinical read and 1 patient (3%) compared with the blinded read without SPECT fusion. Conclusion: Fused CTPA-SPECT perfusion improves the sensitivity of CTPA for the detection of PE in a small number of patients. Fused data may help guide the radiologist to identify sites of PE on CTPA.

  6. Cerebral perfusion in homogeneity in normal volunteers

    International Nuclear Information System (INIS)

    Gruenwald, S.M.; Larcos, G.

    1998-01-01

    Full text: In the interpretation of cerebral perfusion scans, it is important to know the normal variation in perfusion which may occur between the cerebral hemispheres. For this reason 24 normal volunteers with no neurological or psychiatric history, and who were on no medications, had 99m Tc-HMPAO brain SPECT studies using a single headed gamma camera computer system. Oblique, coronal and sagittal images were reviewed separately by two experienced observers and any differences were resolved by consensus. Semi-quantitation was performed by summing two adjacent oblique slices and drawing right and left mirror image ROIs corresponding to the mid section level of anterior and posterior frontal lobes, anterior and posterior parietal lobes, temporal lobes and cerebellum. From the mean counts per pixel, right: left ROI ratios and ROI: cerebellar ratios were calculated. On qualitative review 6/24 subjects had mild asymmetry in tracer distribution between right and left cerebral lobes. Semi-quantitation revealed a 5-10% difference in counts between right and left ROIs in 12/24 subjects and an additional three subjects had 10-20% difference in counts between right and left temporal lobes. This study demonstrates the presence of mild asymmetry of cerebral perfusion in a significant minority of normal subjects

  7. Methodological NMR imaging developments to measure cerebral perfusion

    International Nuclear Information System (INIS)

    Pannetier, N.

    2010-12-01

    This work focuses on acquisition techniques and physiological models that allow characterization of cerebral perfusion by MRI. The arterial input function (AIF), on which many models are based, is measured by a technique of optical imaging at the carotid artery in rats. The reproducibility and repeatability of the AIF are discussed and a model function is proposed. Then we compare two techniques for measuring the vessel size index (VSI) in rats bearing a glioma. The reference technique, using a USPIO contrast agent (CA), faces the dynamic approach that estimates this parameter during the passage of a bolus of Gd. This last technique has the advantage of being used clinically. The results obtained at 4.7 T by both approaches are similar and use of VSI in clinical protocols is strongly encouraged at high field. The mechanisms involved (R1 and R2* relaxivities) were then studied using a multi gradient -echoes approach. A multi-echoes spiral sequence is developed and a method that allows the refocusing between each echo is presented. This sequence is used to characterize the impact of R1 effects during the passage of two successive injections of Gd. Finally, we developed a tool for simulating the NMR signal on a 2D geometry taking into account the permeability of the BBB and the CA diffusion in the interstitial space. At short TE, the effect of diffusion on the signal is negligible. In contrast, the effects of diffusion and permeability may be separated at long echo time. Finally we show that during the extravasation of the CA, the local magnetic field homogenization due to the decrease of the magnetic susceptibility difference at vascular interfaces is quickly balanced by the perturbations induced by the increase of the magnetic susceptibility difference at the cellular interfaces in the extravascular compartment. (author)

  8. Metabolic variations of fatty acid in isolated rat heart reperfused after a transient global ischemia

    International Nuclear Information System (INIS)

    Huang Gang; Michel Comet; Zhao Huiyang; Zhu Cuiying; Yuan Jimin

    1998-01-01

    Purpose: The fatty acid metabolism and the effect of glucose on it were studied in isolated and reperfused rat heat. Methods: 32 isolated working rat hearts were perfused in Langengdorff device with modified Krebs and were divided into normal and ischemia-reperfused group. Each group was also classified into two subgroups, modified krebs with or without glucose subgroup. 131 I-HA was injected into aorta of isolated working rat heart and then the radio-residue curves were acquired. Results: When the isolated rat hearts were perfused with krebs plus glucose, the catabolism of fatty acid was significantly decreased in normal group, but a remarkable increase of fatty acid catabolism was found in ischemia-reperfused group. While the isolated rat hearts were perfused with krebs without glucose, the catabolism of fatty acid in ischemia-reperfused isolated rat hearts were perfused with krebs without glucose, the catabolism of fatty acid in ischemia-reperfused isolated rat heart was less than that in normal group. Conclusions: Transient ischemia damages the catabolism of myocardial fatty acid in mitochondria in some degree. In normal isolated working rat heart, the principal energy source is glucose. However, the major energy source is switched to catabolism of fatty acid in ischemia-reperfused isolated rat heart. This phenomenon may be related to compensative increase of fatty acid catabolism for replenishing the loss of energy during ischemia

  9. Towards robust deconvolution of low-dose perfusion CT: Sparse perfusion deconvolution using online dictionary learning

    Science.gov (United States)

    Fang, Ruogu; Chen, Tsuhan; Sanelli, Pina C.

    2014-01-01

    Computed tomography perfusion (CTP) is an important functional imaging modality in the evaluation of cerebrovascular diseases, particularly in acute stroke and vasospasm. However, the post-processed parametric maps of blood flow tend to be noisy, especially in low-dose CTP, due to the noisy contrast enhancement profile and the oscillatory nature of the results generated by the current computational methods. In this paper, we propose a robust sparse perfusion deconvolution method (SPD) to estimate cerebral blood flow in CTP performed at low radiation dose. We first build a dictionary from high-dose perfusion maps using online dictionary learning and then perform deconvolution-based hemodynamic parameters estimation on the low-dose CTP data. Our method is validated on clinical data of patients with normal and pathological CBF maps. The results show that we achieve superior performance than existing methods, and potentially improve the differentiation between normal and ischemic tissue in the brain. PMID:23542422

  10. 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...

  11. 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.

  12. Developing a Benchmarking Process in Perfusion: A Report of the Perfusion Downunder Collaboration

    Science.gov (United States)

    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

  13. Perfusion MDCT enables early detection of therapeutic response to antiangiogenic therapy.

    Science.gov (United States)

    Sabir, Adeel; Schor-Bardach, Rachel; Wilcox, Carol J; Rahmanuddin, Syed; Atkins, Michael B; Kruskal, Jonathan B; Signoretti, Sabina; Raptopoulos, Vassilios D; Goldberg, S Nahum

    2008-07-01

    The objective of our study was to determine whether perfusion CT can be used to detect early changes in therapeutic response to antiangiogenic therapy in an animal tumor model. Twenty-five rats implanted with R3230 mammary adenocarcinoma (diameter, 1.2-2.0 cm) randomly received 7.5 or 30 mg/kg of an antiangiogenic agent, sorafenib, by daily gavage for 4 (n = 4), 9 (n = 9), or 14 (n = 5) days. Seven untreated animals served as a control group. Perfusion MDCT was performed at days 0, 4, 9, and 14 with 0.4 mL of ioversol (350 mg/mL) and included four 5-mm slices covering the entire tumor volume. Changes in tumor growth were determined by volumetric analysis of CT data. Serial changes in tumor volume and blood flow were assessed and correlated with pathology findings. All control tumors grew larger (from 2.0 +/- 0.7 cm(3) at day 0 to 5.9 +/- 1.0 cm(3) at day 14), whereas all treated tumors shrank (from 2.5 +/- 1.1 to 2.1 +/- 1.0 cm(3)), with a statistically significant rate of growth or shrinkage in both groups (p histopathologic viability despite the fact that these tumors were shrinking in size from day 4 onward (day 4, 2.18 +/- 0.8 cm(3); day 9, 1.98 +/- 0.8 cm(3)). Perfusion MDCT can detect focal blood flow changes even when the tumor is shrinking, possibly indicating early reversal of tumor responsiveness to antiangiogenic therapy. Given that changes in tumor volume after antiangiogenic therapy do not necessarily correlate with true treatment response, physiologic imaging of tumor perfusion may be necessary.

  14. Methodological NMR imaging developments to measure cerebral perfusion; Developpements methodologiques en IRM pour la mesure de perfusion cerebrale

    Energy Technology Data Exchange (ETDEWEB)

    Pannetier, N.

    2010-12-15

    This work focuses on acquisition techniques and physiological models that allow characterization of cerebral perfusion by MRI. The arterial input function (AIF), on which many models are based, is measured by a technique of optical imaging at the carotid artery in rats. The reproducibility and repeatability of the AIF are discussed and a model function is proposed. Then we compare two techniques for measuring the vessel size index (VSI) in rats bearing a glioma. The reference technique, using a USPIO contrast agent (CA), faces the dynamic approach that estimates this parameter during the passage of a bolus of Gd. This last technique has the advantage of being used clinically. The results obtained at 4.7 T by both approaches are similar and use of VSI in clinical protocols is strongly encouraged at high field. The mechanisms involved (R1 and R2* relaxivities) were then studied using a multi gradient -echoes approach. A multi-echoes spiral sequence is developed and a method that allows the refocusing between each echo is presented. This sequence is used to characterize the impact of R1 effects during the passage of two successive injections of Gd. Finally, we developed a tool for simulating the NMR signal on a 2D geometry taking into account the permeability of the BBB and the CA diffusion in the interstitial space. At short TE, the effect of diffusion on the signal is negligible. In contrast, the effects of diffusion and permeability may be separated at long echo time. Finally we show that during the extravasation of the CA, the local magnetic field homogenization due to the decrease of the magnetic susceptibility difference at vascular interfaces is quickly balanced by the perturbations induced by the increase of the magnetic susceptibility difference at the cellular interfaces in the extravascular compartment. (author)

  15. Magnetic Resonance Imaging of Ventilation and Perfusion in the Lung

    Science.gov (United States)

    Prisk, Gordon Kim (Inventor); Hopkins, Susan Roberta (Inventor); Buxton, Richard Bruce (Inventor); Pereira De Sa, Rui Carlos (Inventor); Theilmann, Rebecca Jean (Inventor); Cronin, Matthew Vincent (Inventor)

    2017-01-01

    Methods, devices, and systems are disclosed for implementing a fully quantitative non-injectable contrast proton MRI technique to measure spatial ventilation-perfusion (VA/Q) matching and spatial distribution of ventilation and perfusion. In one aspect, a method using MRI to characterize ventilation and perfusion in a lung includes acquiring an MR image of the lung having MR data in a voxel and obtaining a breathing frequency parameter, determining a water density value, a specific ventilation value, and a perfusion value in at least one voxel of the MR image based on the MR data and using the water density value to determine an air content value, and determining a ventilation-perfusion ratio value that is the product of the specific ventilation value, the air content value, the inverse of the perfusion value, and the breathing frequency.

  16. Myocardial perfusion in type 2 diabetes with left ventricular hypertrophy

    DEFF Research Database (Denmark)

    Hesse, Birger; Meyer, Christian; Nielsen, Flemming S

    2004-01-01

    The purpose of this study was to assess whether acute angiotensin-converting enzyme (ACE) inhibition would improve myocardial perfusion and perfusion reserve in a subpopulation of normotensive patients with diabetes and left ventricular hypertrophy (LVH), both independent risk factors of coronary...... disease. Using positron emission tomography (PET), we investigated the response of regional myocardial perfusion to acute ACE inhibition with i.v. infusion of perindoprilat (vs saline infusion as control, minimum interval 3 days) in 12 diabetic patients with LVH. Myocardial perfusion was quantified...... with controls, maximal perfusion was reduced in patients (1.8+/-0.6 vs 2.5+/-1.0 ml min(-1) g(-1); P2.7+/-1.0 vs 3.6+/-1.3; P=0.059). During perindoprilat infusion, myocardial perfusion reserve in patients increased to 3.9+/-0.9 ( P

  17. Reversible ventilation and perfusion abnormalities in unilateral obstructed lung

    International Nuclear Information System (INIS)

    Ward, H.E.; Jones, R.L.; King, E.G.; Sproule, B.J.; Fortune, R.L.

    1982-01-01

    An intraluminal carcinoid tumor obstructing the left mainstem bronchus produced hypoxemia through alteration in ventilation/perfusion matching. Studies of regional lung function using 133-xenon (/sup 133/Xe) and a multiprobe computerized instrumentation system documented a reduction of perfusion to 22 percent and ventilation to 6 percent of the total. There was negligible washout of intravenously injected /sup 133/Xe from the left lung consistent with air trapping. Four days after left mainstem bronchial sleeve resection, perfusion, ventilation and washout of injected xenon had significantly improved and by four months postresection, all measurements were virtually normal, although complete restoration of perfusion in relation to ventilation was delayed. Regional lung function studied with a multiprobe system in this patient provided a clinical model for the study of ventilation and perfusion inter-relationships in large airway obstruction and demonstrated that a prolonged time may be required for return of perfusion to normal

  18. Kinetics of glucose transport in rat muscle

    DEFF Research Database (Denmark)

    Ploug, Thorkil; Galbo, Henrik; Vinten, Jørgen

    1987-01-01

    The effects of insulin and prior muscle contractions, respectively, on 3-O-methylglucose (3-O-MG) transport in skeletal muscle were studied in the perfused rat hindquarter. Initial rates of entry of 3-O-MG in red gastrocnemius, soleus, and white gastrocnemius muscles as a function of perfusate 3-O-MG...... concentration exhibited Michaelis-Menten kinetics. Uptake by simple diffusion could not be detected. The maximum 3-O-MG transport velocity (Vmax) was increased more by maximum isometric contractions (10- to 40-fold, depending on fiber type) than by insulin (20,000 microU/ml; 3- to 20-fold) in both red and white...

  19. Whole-brain dynamic CT angiography and perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Orrison, W.W. [CHW Nevada Imaging Company, Nevada Imaging Centers, Spring Valley, Las Vegas, NV (United States); College of Osteopathic Medicine, Touro University Nevada, Henderson, NV (United States); Department of Health Physics and Diagnostic Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Department of Medical Education, University of Nevada School of Medicine, Reno, NV (United States); Snyder, K.V.; Hopkins, L.N. [Department of Neurosurgery, Millard Fillmore Gates Circle Hospital, Buffalo, NY (United States); Roach, C.J. [School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States); Ringdahl, E.N. [Department of Psychology, University of Nevada Las Vegas, Las Vegas, NV (United States); Nazir, R. [Shifa International Hospital, Islamabad (Pakistan); Hanson, E.H., E-mail: eric.hanson@amigenics.co [College of Osteopathic Medicine, Touro University Nevada, Henderson, NV (United States); Department of Health Physics and Diagnostic Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States)

    2011-06-15

    The availability of whole brain computed tomography (CT) perfusion has expanded the opportunities for analysing the haemodynamic parameters associated with varied neurological conditions. Examples demonstrating the clinical utility of whole-brain CT perfusion imaging in selected acute and chronic ischaemic arterial neurovascular conditions are presented. Whole-brain CT perfusion enables the detection and focused haemodynamic analyses of acute and chronic arterial conditions in the central nervous system without the limitation of partial anatomical coverage of the brain.

  20. Simultaneous Multiagent Hyperpolarized 13C Perfusion Imaging

    DEFF Research Database (Denmark)

    von Morze, Cornelius; Bok, Robert A.; Reed, Galen D.

    2014-01-01

    in simulations. "Tripolarized" perfusion MRI methods were applied to initial preclinical studies with differential conditions of vascular permeability, in normal mouse tissues and advanced transgenic mouse prostate tumors. Results: Dynamic imaging revealed clear differences among the individual tracer...... distributions. Computed permeability maps demonstrated differential permeability of brain tissue among the tracers, and tumor perfusion and permeability were both elevated over values expected for normal tissues. Conclusion: Tripolarized perfusion MRI provides new molecular imaging measures for specifically...

  1. Adipose-Derived Cell Construct Stabilizes Heart Function and Increases Microvascular Perfusion in an Established Infarct

    Science.gov (United States)

    Nguyen, Quang T.; Touroo, Jeremy S.; Aird, Allison L.; Chang, Raymond C.; Ng, Chin K.; Hoying, James B.; Williams, Stuart K.

    2013-01-01

    We have previously shown that myocardial infarction (MI) immediately treated with an epicardial construct containing stromal vascular fraction (SVF) from adipose tissue preserved microvascular function and left ventricle contractile mechanisms. In order to evaluate a more clinically relevant condition, we investigated the cardiac recovery potential of an SVF construct implanted onto an established infarct. SVF cells were isolated from rat adipose tissue, plated on Vicryl, and cultured for 14 days. Fischer-344 rats were separated into MI groups: (a) 6-week MI (MI), (b) 6-week MI treated with an SVF construct at 2 weeks (MI SVF), (c) 6-week MI with Vicryl construct at 2 weeks (MI Vicryl), and (d) MI 2wk (time point of intervention). Emax, an indicator of systolic performance and contractile function, was lower in the MI and MI Vicryl versus MI SVF. Positron emission tomography imaging (18F-fluorodeoxyglucose) revealed a decreased percentage of relative infarct volume in the MI SVF versus MI and MI Vicryl. Total vessel count and percentage of perfusion assessed via immunohistochemistry were both increased in the infarct region of MI SVF versus MI and MI Vicryl. Overall cardiac function, percentage of relative infarct, and percentage of perfusion were similar between MI SVF and MI 2wk; however, total vessel count increased after SVF treatment. These data suggest that SVF treatment of an established infarct stabilizes the heart at the time point of intervention by preventing a worsening of cardiac performance and infarcted volume, and is associated with increased microvessel perfusion in the area of established infarct. PMID:24106337

  2. REM sleep enhancement and behavioral cataplexy following orexin (hypocretin)-II receptor antisense perfusion in the pontine reticular formation.

    Science.gov (United States)

    Thakkar, M M; Ramesh, V; Cape, E G; Winston, S; Strecker, R E; McCarley, R W

    1999-01-01

    Orexin (hypocretin)-containing neurons of the hypothalamus project to brainstem sites that are involved in the neural control of REM sleep, including the locus coeruleus, the dorsal raphe nucleus, the cholinergic zone of the mesopontine tegmentum, and the pontine reticular formation (PRF). Orexin knockout mice exhibit narcolepsy/cataplexy, and a mutant and defective gene for the orexin type II receptor is present in dogs with an inherited form of narcolepsy/cataplexy. However, the physiological systems mediating these effects have not been described. We reasoned that, since the effector neurons for the majority of REM sleep signs, including muscle atonia, were located in the PRF, this region was likely implicated in the production of these orexin-related abnormalities. To test this possibility, we used microdialysis perfusion of orexin type II receptor antisense in the PRF of rats. Ten to 24 hours after antisense perfusion, REM sleep increased two- to three-fold during both the light period (quiescent phase) and the dark period (active phase), and infrared video showed episodes of behavioral cataplexy. Moreover, preliminary data indicated no REM-related effects following perfusion with nonsense DNA, or when perfusion sites were outside the PRF. More work is needed to provide precise localization of the most effective site of orexin-induced inhibition of REM sleep phenomena.

  3. Effect of Defocused CO2 Laser on Equine Tissue Perfusion

    Directory of Open Access Journals (Sweden)

    Bergh A

    2006-03-01

    Full Text Available Treatment with defocused CO2 laser can have a therapeutic effect on equine injuries, but the mechanisms involved are unclear. A recent study has shown that laser causes an increase in equine superficial tissue temperature, which may result in an increase in blood perfusion and a stimulating effect on tissue regeneration. However, no studies have described the effects on equine tissue perfusion. The aim of the present study was to investigate the effect of defocused CO2 laser on blood perfusion and to correlate it with temperature in skin and underlying muscle in anaesthetized horses. Differences between clipped and unclipped haircoat were also assessed. Eight horses and two controls received CO2 laser treatment (91 J/cm2 in a randomised order, on a clipped and unclipped area of the hamstring muscles, respectively. The significant increase in clipped skin perfusion and temperature was on average 146.3 ± 33.4 perfusion units (334% and 5.5 ± 1.5°C, respectively. The significant increase in perfusion and temperature in unclipped skin were 80.6 ± 20.4 perfusion units (264% and 4.8 ± 1.4°C. No significant changes were seen in muscle perfusion or temperature. In conclusion, treatment with defocused CO2 laser causes a significant increase in skin perfusion, which is correlated to an increase in skin temperature.

  4. Perfusion lung scanning: differentiation of primary from thromboembolic pulmonary hypertension

    International Nuclear Information System (INIS)

    Lisbona, R.; Kreisman, H.; Novales-Diaz, J.; Derbekyan, V.

    1985-01-01

    Of eight patients with pulmonary arterial hypertension, final diagnosis established by autopsy or angiography, four had primary hypertension and four hypertension from thromboembolism. The perfusion lung scan was distinctly different in the two groups. The lung scan in primary pulmonary hypertension was associated with nonsegmental, patchy defects of perfusion, while in thromboembolic hypertensives it was characterized by segmental and/or lobar defects of perfusion with or without subsegmental defects. The perfusion lung scan is a valuable, noninvasive study in the evaluation of the patient with pulmonary hypertension of undetermined cause and in the exclusion of occult large-vessel pulmonary thromboembolism

  5. Effect of dimethylaminoethanol, an inhibitor of betaine production, on the disposition of choline in the rat kidney

    International Nuclear Information System (INIS)

    Lohr, J.; Acara, M.

    1990-01-01

    The choline metabolite betaine has been shown to be an important organic osmoregulatory solute in the kidney. The isolated perfused rat kidney and kidney slice incubations were used to investigate the effect of 2-dimethylaminoethanol (DMAE), a choline oxidase inhibitor, on the renal excretion and metabolism of choline. In the isolated perfused kidney, [ 14 C]choline, at an initial perfusate concentration of 300 microM, was effectively removed from the perfusate over 25 min, with nearly all the 14 C in the perfusate accounted for by betaine during the remainder of the 90-min perfusion. DMAE at concentrations of 3.0 or 5.0 mM significantly decreased the rate of removal of [ 14 C]choline from the perfusate and the rate of addition of [ 14 C]betaine to the perfusate, yet [14C]betaine remained the only metabolite of choline in perfusate and urine. In kidney tissue slice experiments, conversion of [ 14 C]choline to [ 14 C]betaine was found in cortical, outer medullary and inner medullary regions of rat kidney. DMAE at 5.0 mM significantly inhibited [ 14 C]betaine production in each of the three regions studied. These data show that DMAE is an effective inhibitor of betaine production by the kidney and, as such, may be an important agent for the study of osmoregulation by the kidney

  6. Effect of pH, buffer concentration and buffer composition on the absorption of theophylline from the small intestine of the rat

    NARCIS (Netherlands)

    Blaey, C.J. de; Schurgers, N.

    1984-01-01

    The absorption of theophylline from the small intestine of the rat was investigated using buffer solutions of different pH (3.0–9.2), composition and concentration. The technique used, encloses luminal perfusion of an intestinal loop with collection of the blood draining the perfused loop, which

  7. Compartmented pyruvate in perfused working heart

    International Nuclear Information System (INIS)

    Buenger, R.

    1985-01-01

    Pyruvate compartmentation and lactate dehydrogenase (LDH) were studied in isolated perfused working guinea pig hearts. The mean intracellular pyruvate (Pyr) contents increased with perfusate Pyr (0-2 mM) but varied only slightly with glucose (0-10 mM) and additional insulin (0.04-5 U/l), respectively. With 5-10 mM glucose plus 5 U/l insulin, but not with Pyr or lactate (Lac) as substrates, a near equilibrium between the LDH and the glycerol-3-phosphate dehydrogenase seemed to exist. Evidence for an inhibitory effect of Pyr on the activity of the LDH system of the perfused hearts was not obtained. With [U- 14 C]glucose as sole substrate, the specific activity of coronary venous Lac was near half that of precursor glucose. 14 CO 2 production was thus in quantitative agreement with rates of pyruvate oxidation that were determined as glucose uptake minus (Pyr + Lac) release. In contrast, with 0.2 mM [1- 14 C]Pyr plus 5 mM glucose, the ratio of 14 CO 2 production to specific activity of Lac overestimated Pyr oxidation judged from myocardial substrate balances and O 2 uptake, respectively; here, at least three pools of [ 14 C]HCO-3 and [ 14 C]lac, respectively, were kinetically demonstrable during washout of trace amounts of 14 C-labeled Pyr. Evidently, the specific activity of Lac was equivalent to that of mitochondrial oxidized Pyr provided [ 14 C]glucose was the sole or major precursor of cellular pyruvate. However, exogenously applied [1- 14 C]Pyr of high specific activity seemed to induce intracellular formation of both a highly and lowly labeled Pyr; the latter Pyr compartment did not seem in ready equilibrium with the cell physiologically prevailing highly labeled Pyr pool

  8. [Myocardial perfusion imaging by digital subtraction angiography].

    Science.gov (United States)

    Kadowaki, H; Ishikawa, K; Ogai, T; Katori, R

    1986-03-01

    Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; at the R wave of the electrocardiogram, 100 msec before the R wave, and 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. [Myokard-Perfusions-SPECT. Myocardial perfusion SPECT - Update S1 guideline].

    Science.gov (United States)

    Lindner, Oliver; Bengel, Frank; Burchert, Wolfgang; Dörr, Rolf; Hacker, Marcus; Schäfer, Wolfgang; Schäfers, Michael A; Schmidt, Matthias; Schwaiger, Markus; Vom Dahl, Jürgen; Zimmermann, Rainer

    2017-08-14

    The S1 guideline for myocardial perfusion SPECT has been published by the Association of the Scientific Medical Societies in Germany (AWMF) and is valid until 2/2022. This paper is a short summary with comments on all chapters and subchapters wich were modified and amended.

  10. The effects of angiotensin II receptor antagonist (candesartan on rat renal vascular resistance

    Directory of Open Access Journals (Sweden)

    Supatraviwat, J

    2004-05-01

    Full Text Available The present study aimed to investigate the action of angiotensin II (AII on renal perfusion pressure and renal vascular resistance using noncompetitive AT1-receptor antagonist (candesartan or CV 11974. Experiments were performed in isolated kidney of adult male Wistar rats. Kreb's Henseleit solution was perfused into the renal artery at the rate of 3.5 ml/min. This flow rate was designed in order to maintain renal perfusion pressure between 80-120 mm Hg. Dose-response relationship between perfusion flow rate and AII concentration were studied. Renal perfusion pressure in response to 1, 10 and 100 nM AII were increased from basal perfusion pressure of 94±8 mm Hg to 127±6, 157±12 and 190±16 mm Hg, respectively. Administration of perfusate containing 11.4 μM candesartan for 30 min had no effect on the basal perfusion pressure. However, this significantly reduced renal perfusion pressure in the presence of AII (1, 10 and 100 nM by 39%, 47% and 61%, (n=7, P<0.05 respectively. At the basal perfusion pressure, calculated renal vascular resistance was 27±2 mm Hg · min · ml-1. However, the vascular resistance were found to be 41±1, 45±2 and 47±2 mm Hg · min · ml-1 when 1, 10 and 100 nM AII were added. Moreover, this dose of candesartan also showed a significant decrease in renal vascular resistance at the corresponding doses of AII by 38%, 48% and 43%, (n=7, P<0.05 respectively. The higher dose of candesartan (22.7 μM completely inhibited the action of 1, 10 and 100 nM AII on renal vasoconstriction. These results may indicate that the action of AII on renal vascular resistance is via AT1-receptor, at least in rat isolated perfusion kidney.

  11. Impact of intestinal ischemia/reperfusion and lymph drainage on distant organs in rats

    Science.gov (United States)

    He, Gui-Zhen; Zhou, Kai-Guo; Zhang, Rui; Wang, Yu-Kang; Chen, Xue-Feng

    2012-01-01

    AIM: To investigate the impact of intestinal ischemia/reperfusion (I/R) injury and lymph drainage on distant organs in rats. METHODS: Thirty-two Sprague-Dawley male rats, weighing 280-320 g, were randomly divided into blank, sham, I/R, and ischemia/reperfusion and drainage (I/R + D) groups (n = 8). All rats were subjected to 60 min ischemia by clamping the superior mesenteric artery, followed by 120 min reperfusion. The rats in the I/R + D group received intestinal lymph drainage for 180 min. In the sham group, the abdominal cavity was opened for 180 min, but the rats received no treatment. The blank group served as a normal and untreated control. A chromogenic limulus assay kit was used for quantitative detection of serum endotoxin. The serum concentrations of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1β, soluble cell adhesion molecules (sICAM-1), and high mobility group protein box 1 (HMGB1) were determined with an enzyme-linked immunosorbent assay kit. Histological evaluations of the intestine, liver, kidney, and lung were performed by hematoxylin and eosin staining and immunohistochemistry. HMGB1 protein expression was assayed by western blot analysis. RESULTS: The serum levels of endotoxin and HMGB1 in the I/R and I/R + D groups were significantly higher than those in the sham group (endotoxin, I/R and I/R + D vs sham: 0.033 ± 0.004 EU/mL, 0.024 ± 0.003 EU/mL vs 0.017 ± 0.009 EU/mL, respectively, P drainage could block the “gut-lymph” pathway, improve intestinal barrier function, and attenuate distant organ injury incurred by intestinal I/R. PMID:23326132

  12. Diffusion and perfusion imaging of bone marrow

    International Nuclear Information System (INIS)

    Biffar, Andreas; Dietrich, Olaf; Sourbron, Steven; Duerr, Hans-Roland; Reiser, Maximilian F.; Baur-Melnyk, Andrea

    2010-01-01

    In diffusion-weighted magnetic resonance imaging (DWI), the observed MRI signal intensity is attenuated by the self-diffusion of water molecules. DWI provides information about the microscopic structure and organization of a biological tissue, since the extent and orientation of molecular motion is influenced by these tissue properties. The most common method to measure perfusion in the body using MRI is T1-weighted dynamic contrast enhancement (DCE-MRI). The analysis of DCE-MRI data allows determining the perfusion and permeability of a biological tissue. DWI as well as DCE-MRI are established techniques in MRI of the brain, while significantly fewer studies have been published in body imaging. In recent years, both techniques have been applied successfully in healthy bone marrow as well as for the characterization of bone marrow alterations or lesions; e.g., DWI has been used in particular for the differentiation of benign and malignant vertebral compression fractures. In this review article, firstly a short introduction to diffusion-weighted and dynamic contrast-enhanced MRI is given. Non-quantitative and quantitative approaches for the analysis of DWI and semiquantitative and quantitative approaches for the analysis of DCE-MRI are introduced. Afterwards a detailed overview of the results of both techniques in healthy bone marrow and their applications for the diagnosis of various bone-marrow pathologies, like osteoporosis, bone tumors, and vertebral compression fractures are described.

  13. Brain perfusion imaging with iodinated amines

    International Nuclear Information System (INIS)

    Kung, H.F.

    1989-01-01

    Traditional nuclear medicine brain study using 99m Tc pertechnetate, glucoheptonate or diethlenetriaminepentacetic acid (DTPA) and planar imaging has experienced a significant decline in the past 10 years. This is mainly due to the introduction of X-ray CT and more recently the nuclear magnetic resonance (NMR) imaging, by which detailed morphology of the brain, including the detection of breakdown of the blood-brain barrier, can be obtained. The nuclear medicine brain imaging is only prescribed as a complementary test when X-ray CT is negative or equivocal and clinical suspicion remains. The attention of nuclear medicine brain imaging has been shifted from the detection of the breakdown of the blood-brain barrier to the study of brain function-perfusion, metabolism, and receptor binding, etc. The functional brain imaging provides diagnostic information usually unattainable by other radiological techniques. In this article, the iodinated amines as brain perfusion imaging agents are reviewed. Potential clinical application of these agents is discussed

  14. Lung perfusion scintigraphy in congenital heart disease

    International Nuclear Information System (INIS)

    Sugimura, Hiroshi; Nagamachi, Shigeki; Hoshi, Hiroaki; Jinnouchi, Seishi; Oonishi, Takashi; Futami, Shigemi; Watanabe, Katsushi

    1990-01-01

    Lung perfusion scintigrams were reviewed retrospectively in 28 patients with congenital heart disease, whose ages ranged from the first year to 16 years with an average age of 5 years and 6 months. Seventy four MBq (2 mCi), 111 MBq (2 mCi), and 185 MBq (5 mCi) of Tc-99m macroaggregated albumin were iv injected in the age groups of 0-3, 4-11, and more than 11 years, respectively. Five minutes later, images were obtained in six projections. Abnormal findings on lung perfusion scintigrams were observed in 13 patients (46%). Of these patients, 8 (29%) had a partially decreased blood flow and 5 (17%) had a decreased blood flow in the unilateral lung. No significant difference in the occurrence of abnormal findings was observed among the age groups, although they tended to occur in younger patients. Sex, underlying conditions, and hemodynamics were also independent of scintigraphically abnormal findings. Even when classifying the patients as having either cyanotic or non-cyanotic heart disease, no significant difference in hemodynamics was observed between the group of abnormal findings and the group of normal findings. Pulmonary arteriography available in all patients failed to reveal abnormal findings, with the exception of pulmonary artery stenosis in 2 patients that corresponded to a decreased blood flow in the unilateral lung. Pulmonary artery stenosis seemed to be responsible for abnormal pulmonary blood flow, although other causes remained uncertain. (N.K.)

  15. Visualization of myocardial perfusion derived from coronary anatomy

    NARCIS (Netherlands)

    Termeer, M.A.; Bescos, J.O.; Breeuwer, M.; Vilanova, A.; Gerritsen, F.A.; Gröller, M.E.; Nagel, Eike

    2008-01-01

    Visually assessing the effect of the coronary artery anatomy on the perfusion of the heart muscle in patients with coronary artery disease remains a challenging task. We explore the feasibility of visualizing this effect on perfusion using a numerical approach. We perform a computational simulation

  16. Perfusion MR imaging for differentiation of benign and malignant meningiomas

    NARCIS (Netherlands)

    Zhang, Hao; Rodiger, Lars A.; Shen, Tianzhen; Miao, Jingtao; Oudkerk, Matthijs

    Introduction Our purpose was to determine whether perfusion MR imaging can be used to differentiate benign and malignant meningiomas on the basis of the differences in perfusion of tumor parenchyma and/or peritumoral edema. Methods A total of 33 patients with preoperative meningiomas (25 benign and

  17. Spatio-temporal analysis of blood perfusion by imaging photoplethysmography

    Science.gov (United States)

    Zaunseder, Sebastian; Trumpp, Alexander; Ernst, Hannes; Förster, Michael; Malberg, Hagen

    2018-02-01

    Imaging photoplethysmography (iPPG) has attracted much attention over the last years. The vast majority of works focuses on methods to reliably extract the heart rate from videos. Only a few works addressed iPPGs ability to exploit spatio-temporal perfusion pattern to derive further diagnostic statements. This work directs at the spatio-temporal analysis of blood perfusion from videos. We present a novel algorithm that bases on the two-dimensional representation of the blood pulsation (perfusion map). The basic idea behind the proposed algorithm consists of a pairwise estimation of time delays between photoplethysmographic signals of spatially separated regions. The probabilistic approach yields a parameter denoted as perfusion speed. We compare the perfusion speed versus two parameters, which assess the strength of blood pulsation (perfusion strength and signal to noise ratio). Preliminary results using video data with different physiological stimuli (cold pressure test, cold face test) show that all measures are influenced by those stimuli (some of them with statistical certainty). The perfusion speed turned out to be more sensitive than the other measures in some cases. However, our results also show that the intraindividual stability and interindividual comparability of all used measures remain critical points. This work proves the general feasibility of employing the perfusion speed as novel iPPG quantity. Future studies will address open points like the handling of ballistocardiographic effects and will try to deepen the understanding of the predominant physiological mechanisms and their relation to the algorithmic performance.

  18. Perfusion Electronic Record Documentation Using Epic Systems Software.

    Science.gov (United States)

    Riley, Jeffrey B; Justison, George A

    2015-12-01

    The authors comment on Steffens and Gunser's article describing the University of Wisconsin adoption of the Epic anesthesia record to include perfusion information from the cardiopulmonary bypass patient experience. We highlight the current-day lessons and the valuable quality and safety principles the Wisconsin-Epic model anesthesia-perfusion record provides.

  19. Hypothermic Machine Perfusion of Kidney Grafts: Which Pressure is Preferred?

    NARCIS (Netherlands)

    Doorschodt, B. M.; Schreinemachers, M. C. J. M.; Behbahani, M.; Florquin, S.; Weis, J.; Staat, M.; Tolba, R. H.

    2011-01-01

    To assess the effect of the perfusion pressure (PP) during machine perfusion (MP) on the preservation quality of kidney grafts, we compared mean PPs of 25 and 30 mmHg using a porcine autotransplantation model. After assessment of the microcirculation, animals underwent left nephrectomy. Thereafter,

  20. Ex-vivo machine perfusion for kidney preservation.

    Science.gov (United States)

    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.

  1. Resistance to Reperfusion Injury Following Short Term Postischemic Administration of Natural Honey in Globally Ischemic Isolated Rat Heart

    OpenAIRE

    Haleh Vaez; Mehrban Samadzadeh; Fahimeh Zahednezhad; Moslem Najafi

    2012-01-01

    Purpose: Results of our previous study revealed that preischemic perfusion of honey before zero flow global ischemia had cardioprotective effects in rat. The present study investigated potential resistance to reperfusion injury following short term postischemic administration of natural honey in globally ischemic isolated rat heart. Methods: Male Wistar rats were divided into five groups (n=10-13). The rat hearts were isolated, mounted on a Langendorff apparatus, allowed to equilibra...

  2. 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.)

  3. 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)

  4. 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....

  5. A model system for perfusion quantification using FAIR

    DEFF Research Database (Denmark)

    Andersen, I.K.; Sidaros, Karam; Gesmar, H

    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...

  6. Pathologic evaluation of normal and perfused term placental tissue

    DEFF Research Database (Denmark)

    Maroun, Lisa Leth; Mathiesen, Line; Hedegaard, Morten

    2014-01-01

    This study reports for the 1st time the incidence and interobserver variation of morphologic findings in a series of 34 term placentas from pregnancies with normal outcome used for perfusion studies. Histologic evaluation of placental tissue is challenging, especially when it comes to defining...... "normal tissue" versus "pathologic lesions." A scoring system for registration of abnormal morphologic findings was developed. Light microscopic examination was performed independently by 2 pathologists, and interobserver variation was analyzed. Findings in normal and perfused tissue were compared...... and selected findings were tested against success parameters from the perfusions. Finally, the criteria for frequent lesions with fair to poor interobserver variation in the nonperfused tissue were revised and reanalyzed. In the perfused tissue, the perfusion artefact "trophoblastic vacuolization," which...

  7. Nifedipine and thallium-201 myocardial perfusion in progressive systemic sclerosis

    International Nuclear Information System (INIS)

    Kahan, A.; Devaux, J.Y.; Amor, B.

    1986-01-01

    Heart disease in patients with progressive systemic sclerosis may be due in part to myocardial ischemia caused by a disturbance of the coronary microcirculation. To determine whether abnormalities of myocardial perfusion in this disorder are potentially reversible, we evaluated the effect of the coronary vasodilator nifedipine on myocardial perfusion assessed by thallium-201 scanning in 20 patients. Thallium-201 single-photon-emission computerized tomography was performed under control conditions and 90 minutes after 20 mg of oral nifedipine. The mean (+/- SD) number of left ventricular segments with perfusion defects decreased from 5.3 +/- 2.0 to 3.3 +/- 2.2 after nifedipine (P = 0.0003). Perfusion abnormalities were quantified by a perfusion score (0 to 2.0) assigned to each left ventricular segment and by a global perfusion score (0 to 18) for the entire left ventricle. The mean perfusion score in segments with resting defects increased from 0.97 +/- 0.24 to 1.26 +/- 0.44 after nifedipine (P less than 0.00001). The mean global perfusion score increased from 11.2 +/- 1.7 to 12.8 +/- 2.4 after nifedipine (P = 0.003). The global perfusion score increased by at least 2.0 in 10 patients and decreased by at least 2.0 in only 1. These observations reveal short-term improvement in thallium-201 myocardial perfusion with nifedipine in patients with progressive systemic sclerosis. The results are consistent with a potentially reversible abnormality of coronary vasomotion in this disorder, but the long-term therapeutic effects of nifedipine remain to be determined

  8. 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.

  9. 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

  10. Modification of sympathetic neuronal function in the rat tail artery by dietary lipid treatment

    International Nuclear Information System (INIS)

    Panek, R.L.; Dixon, W.R.; Rutledge, C.O.

    1985-01-01

    The effect of dietary lipid treatment on sympathetic neuronal function was examined in isolated perfused tail arteries of adult rats. The hypothesis that dietary manipulations alter the lipid environment of receptor proteins which may result in the perturbation of specific membrane-associated processes that regulate peripheral adrenergic neurotransmission in the vasculature was the basis for this investigation. In the present study, rats were fed semisynthetic diets enriched in either 16% coconut oil (saturated fat) or 16% sunflower oil (unsaturated fat). The field stimulation-evoked release of endogenous norepinephrine and total 3 H was decreased significantly in rats receiving the coconut oil diet when compared to either sunflower oil- or standard lab chow-fed rats. Norepinephrine content in artery segments from coconut oil-treated rats was significantly higher compared to either sunflower oil- or standard lab chow-fed rats. Tail arteries from rats receiving the coconut oil diet displayed significantly lower perfusion pressure responses to nerve stimulation at all frequencies tested when compared to the sunflower oil- or standard lab chow-fed rats. Vasoconstrictor responses of perfused tail arteries exposed to exogenous norepinephrine resulted in an EC50 for norepinephrine that was not changed by the dietary treatment, but adult rats receiving the sunflower oil diet displayed a significantly greater maximum response to exogenous norepinephrine (10(-5) M) compared to arteries from either coconut oil- or standard lab chow-fed rats

  11. 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.

  12. Myocardial perfusion studies in coronary diseases; Estudios de Perfusion Miocardica en la Enfermedad Coronaria

    Energy Technology Data Exchange (ETDEWEB)

    Mut, Fernando [Universidad de la Republica, Montevideo (Uruguay)

    1994-12-31

    For detecting in precocious form a coronary disease is necessary to apply a diagnostic techniques. The main considerations to be indicated in the present work are: physiological considerations, myocardial perfusion studies with radiotracers such as Talio 201, 99mTc, MIBI, 99mTc-Teboroxima, 99mTc-Fosfinas, instrumentation for obtain good images,proceedings protocols, studies interpretation, standards, SPECT, anomalies standards, coronary diseases.

  13. Perfusion scintigraphy in acute myocardial infarction

    International Nuclear Information System (INIS)

    Schricke, U.; Schwaiger, M.; Kastrati, A.; Schoemig, A.

    1999-01-01

    The Tc-99m sestamibi perfusion SPECT scintigraphy in acute myocardial infarction is a feasible method to assess the size of area at risk and the residual blood flow to this area as the most important determinants of final infarct size without any delay in treatment. In combination with a follow-up study final infarct size as well as myocardial salvage can be quantified. Clinical indications for the use of Tc-99m sestamibi scintigraphy are the noninvasive identification of arterial occlusion in patients suspected to acute myocardial infarction without electrocardiographic ST-elevation and the assessment of reperfusion success. In clinical trials Tc-99m sestamibi scintigraphy has proven to be a useful method to assess the impact of varying reperfusion therapies. The present review article discusses the indication, the study protocol, the interpretation of results and the clinical and scientifically importance of this method. (orig.) [de

  14. Emergency perfusion lung scan of pulmonary embolism

    International Nuclear Information System (INIS)

    Ueno, Kyoichi; Kabuto, Hiroko; Rikimaru, Shigeho

    1984-01-01

    Pulmonary embolism (PE) has been reported to be quite rare in Japan, and there have been few clinical studies on the nuclear diagnosis of PE with the exception of several case reports. However, we have experienced 12 acute PE, and 2 chronic PE in 5 years 2 months. In 33 emergency cases who were highly suspected to have PE, we could diagnose 12 cases of PE, and 19 cases of non-PE. However, the remaining 2 cases were equivocal because of underlying chronic lung disease. Using Kr-81m ventilation lung scan, V/Q mismatch was found in all of 10 cases. Usefulness of emergency perfusion lung scan in Japan should be stressed. (author)

  15. Ventilation and ventilation/perfusion ratios

    International Nuclear Information System (INIS)

    Valind, S.O.

    1989-01-01

    The thesis is based on five different papers. The labelling of specific tracer compounds with positron emitting radionuclides enables a range of structural, physiological and biochemical parameters in the lung to be measured non-invasively, using positron emission tomography. This concept affords a unique opportunity for in vivo studies of different expressions of pulmonary pathophysiology at the regional level. The present thesis describes the application of positron emission tomography to the measurements of ventilation and ventilation/perfusion ratios using inert gas tracers, neon-19 and nitrogen-13 respectively. The validity of the methods applied was investigated with respect to the transport of inert gas tracers in the human lung. Both ventilation and the ventilation/perfusion ratio may be obtained with errors less than 10 % in the normal lung. In disease, however, errors may increase in those instances where the regional ventilation is very low or the intra-regional gas flow distribution is markedly nonuniform. A 2-3 fold increase in ventilation was demonstrated in normal nonsmoking subjects going from ventral to dorsal regions in the supine posture. These large regional differences could be well explained by the intrinsic elastic properties of lung tissue, considering the gravitational gradient in transpulmonary pressure. In asymptomatic smokers substantial regional ventilatroy abnormalities were found whilst the regional gas volume was similar in smokers and nonsmokers. The uncoupling between ventilation and gas volume probably reflects inflammatory changes in the airways. The regional differences in dV/dt/dQ/dt were relatively small and blood flow was largely matched to ventilation in the supine posture. However, small regions of lung with very low ventilation, unmatched by blood flow commonly exists in the most dependent parts of the lung in both smokers and nonsmokers. (29 illustrations, 7 tables, 113 references)

  16. Brain perfusion SPECT in dementia syndromes

    International Nuclear Information System (INIS)

    Libus, P.; Stupalova, J.; Kuzelka, I.; Konrad, J.

    2002-01-01

    Aim: Brain perfusion SPECT is used in differential diagnostics of dementia syndromes. First of all the aim is to distinguish vascular dementia from degenerative dementia and to differentiate dementia from delirium, psychiatric syndromes, depression and secondary dementia, which is important in relation to therapy. The purpose of our study was to detect significance of BP SPECT and include it into the diagnostic process in dementia syndromes. Materials and methods: 51 women and 63 men aged 55 - 88 were evaluated in the study. The patients correspond to the general criteria of dementia diagnosis. They were sent to the examination by neurological, internal and psychiatric departments and out-patient departments. All patients were examined by 99mTc ECD SPECT using a double head camera PRISM 200 VP with LEHR collimator. The scintigraphic data were evaluated by the visual and semiquantitative analysis. Results: It was established that most patients in our group had vascular dementia, while Alzheimer's disease was second. In other groups we found out dementia at strategic infarct location, e.g. in gyrus angularis in the dominant hemisphere, frontal temporal lobe dementia and alcoholic dementia. Twenty-four patients had a normal diagnosis. Fifteen of them had a somatic reason of the delirious state and were re-classified into pseudodementia. Nine patients were not diagnostically included and the examination will repeated in four months time. Conclusion: We have found out a good applicability of brain perfusion SPECT in dementia syndromes diagnosis in our work. The best diagnosticable and most specific were the findings in multi-infarct dementia, Alzheimer's disease and frontal temporal lobe dementia. When vascular dementia is concerned we can even distinguish dementia at strategic infarction location, e.g. in thalamus, basal frontal telencefalon, in gyrus angularis of the dominant hemisphere, etc

  17. Influence of ocular perfusion pressure fluctuation on glaucoma

    Directory of Open Access Journals (Sweden)

    Min-Zi Ren

    2015-12-01

    Full Text Available AIM:To investigate the influence of ocular perfusion pressure fluctuation on glaucoma. METHODS:Forty patients with primary open angle glaucoma from January 2013 to June 2015 in our hospital were used as observation group and 40 families were used as control group. Circadian fluctuation of intraocular pressure, blood pressure and ocular perfusion pressure in 24h were determined to obtain systolic ocular perfusion pressure(SOPP, diastolic ocular perfusion pressure(DOPPand mean ocular perfusion pressure(MOPP. Pearson linear correlation was used to analyze the correlation of circadian MOPP fluctuation with cup-disc ratio, mean defect(MDand the picture standard deviation(PSD. RESULTS:The fluctuation of MOPP, SOPP and DOPP of observation group were significantly higher than those of control group(Pr=-0.389, 95%CI:-0.612~-0.082; P=0.011, was positively correlated with PSD(r=0.512, 95%CI:0.139 ~0.782; P=0.008; no correlation was found between it and the vertical cup-disc ratio(r=0.115, 95%CI:0.056~0.369; P=0.355. CONCLUSION:Ocular perfusion pressure fluctuations in patients with primary open angle glaucoma may reflect the severity of the disease and may make the situation aggravating. Therefore through perfusion pressure monitor in 24h may help us understand the ocular blood flow and the development of primary open-angle glaucoma.

  18. PET imaging of cerebral perfusion and oxygen metabolism in stroke

    Energy Technology Data Exchange (ETDEWEB)

    Pointon, O.; Yasaka, M.; Berlangieri, S.U.; Newton, M.R.; Thomas, D.L.; Chan, C.G.; Egan, G.F.; Tochon-Danguy, H.J.; O``Keefe, G.; Donnan, G.A.; McKay, W.J. [Austin Hospital, Melbourne, VIC (Australia). Centre for PET and Depts of Nuclear Medicine and Neurology

    1998-03-01

    Full text: Stroke remains a devastating clinical event with few therapeutic options. In patients with acute stroke, we studied the cerebral perfusion and metabolic patterns with {sup 15}O-CO{sub 2} or H{sub 2}O and {sup 15}O-O{sub 2} positron emission tomography and correlated these findings to the clinical background. Forty three patients underwent 45 studies 0-23 days post-stroke (mean 7 days). Fifteen patients showed luxury perfusion (Group A), 10 had matched low perfusion and metabolism (B) and 3 showed mixed pattern including an area of misery perfusion (C). Seventeen showed no relevant abnormality (D) and there were no examples of isolated misery perfusion. Twelve of the 15 in Group A had either haemorrhagic transformation on CT, re-opening on angiography, or a cardioembolic mechanism. In contrast only 5/10 in Group B, 0/3 in Group C and 2/17 in Group D had these features. Although 7/10 in group B had moderate or large size infarcts on CT the incidence of haemorrhagic transformation was low (2/10) and significant carotid stenoses were more common in those studied (5/8) compared with the other groups. Misery perfusion was not seen beyond five days. Thus, luxury perfusion seems to be related to a cardio-embolic mechanism or reperfusion. Matched low perfusion and metabolism was associated with a low rate of haemorrhagic transformation despite a high incidence of moderate to large size infarcts. Misery perfusion is an early phenomenon in the evolution of ischaemic stroke.

  19. Perfusion decellularization of a human limb: A novel platform for composite tissue engineering and reconstructive surgery.

    Directory of Open Access Journals (Sweden)

    Mattia Francesco Maria Gerli

    Full Text Available Muscle and fasciocutaneous flaps taken from autologous donor sites are currently the most utilized approach for trauma repair, accounting annually for 4.5 million procedures in the US alone. However, the donor tissue size is limited and the complications related to these surgical techniques lead to morbidities, often involving the donor sites. Alternatively, recent reports indicated that extracellular matrix (ECM scaffolds boost the regenerative potential of the injured site, as shown in a small cohort of volumetric muscle loss patients. Perfusion decellularization is a bioengineering technology that allows the generation of clinical-scale ECM scaffolds with preserved complex architecture and with an intact vascular template, from a variety of donor organs and tissues. We recently reported that this technology is amenable to generate full composite tissue scaffolds from rat and non-human primate limbs. Translating this platform to human extremities could substantially benefit soft tissue and volumetric muscle loss patients providing tissue- and species-specific grafts. In this proof-of-concept study, we show the successful generation a large-scale, acellular composite tissue scaffold from a full cadaveric human upper extremity. This construct retained its morphological architecture and perfusable vascular conduits. Histological and biochemical validation confirmed the successful removal of nuclear and cellular components, and highlighted the preservation of the native extracellular matrix components. Our results indicate that perfusion decellularization can be applied to produce human composite tissue acellular scaffolds. With its preserved structure and vascular template, these biocompatible constructs, could have significant advantages over the currently implanted matrices by means of nutrient distribution, size-scalability and immunological response.

  20. Nuclear medicine and coronary artery disease: evaluation of tracers of myocardial perfusion and vulnerable atherosclerotic plaque

    International Nuclear Information System (INIS)

    Broisat, A.

    2005-04-01

    Coronary artery disease is one of the primary cause of mortality worldwide. Nuclear medicine is the major imaging technique for diagnosis and following of this disease. perfusion: nowadays, major radioactive agents used in clinical practice are myocardial perfusion tracers. The reference tracer is thallium-201. However, 201 Tl presents some drawbacks. 99m Tcn-noet has been proposed for its replacement. This study shows that in contrast with previous studies realized in vitro on cardio myocytes, verapamil, an l-type calcium channel inhibitor, does not inhibit myocardial fixation of 99m Tcn-noet in vivo in dog. This data is in agreement with the hypothesis of a non specific endothelial fixation of this tracer. Moreover, this study shows that as a pure tracer of myocardial perfusion, 99m Tcn-noet can also be used to assess myocardial viability on a model of myocardial chronic infarction in rat. atherosclerosis: disruption of vulnerable atherosclerotic plaques is the main event leading to coronary accidents. The second part of this study concerns the evaluation of new potential tracers of the vulnerable atherosclerotic plaque in an experimental model of rabbit with an inheritable hypercholesterolemia. The four tracers evaluated (b2702(r), b2702-I, b2702-Tc and Tc-raft-b2702) are synthetic peptides comprising the residues 75-84 of hla-b2702, a molecule known to link vcam-1, an adhesion molecule expressed in vulnerable atherosclerotic plaque. The autoradiography studies show that all tracers accumulate within atherosclerotic plaque expressing vcam- and that. i-b2702 shows the best plaque/control fixation ratio. (author)

  1. Myocardial perfusion alterations observed months after radiotherapy are related to the cellular damage

    Energy Technology Data Exchange (ETDEWEB)

    Dogan, I.; Sonmez, B. [Karadeniz Technical Univ., Trabzon (Turkey). Dept. of Nuclear Medicine; Sezen, O.; Zengin, A.Y.; Bahat, Z. [Karadeniz Technical Univ., Trabzon (Turkey). Dept. of Radiation Oncology; Yenilmez, E.; Yulug, E. [Karadeniz Technical Univ., Trabzon (Turkey). Dept. of Histology and Embryology; Abidin, I. [Karadeniz Technical Univ., Trabzon (Turkey). Dept. of Biophysics

    2010-07-01

    Myocardial perfusion scintigraphy (MPS) is one of the widely used tools to follow developing radiation-induced heart disease (RIHD). But the clinical significance of MPS defects has not been fully understood. We have investigated the biodistribution alterations related to perfusion defects following radiotherapy (RT) and showed coexisting morphological changes. Animals, methods: A total of 18 Wistar rats were divided into three groups (1 control and 2 irradiated groups). A single cardiac 20 Gy radiation dose was used to induce long term cardiac defects. Biodistribution studies with technetium ({sup 99m}Tc) sestamibi and histological evaluations were performed 4 and 6 months after irradiation. The percent radioactivity (%ID/g) was calculated for each heart. For determination of the myocardial damage, positive apoptotic cardiomyocytes, myocardial cell degeneration, myocardial fibrosis, vascular damage and ultrastructural structures were evaluated. Results: Six months after treatment, a significant drop of myocardial uptake was observed (p < 0.05). Irradiation-induced apoptosis rose within the first 4 months after radiation treatment and were stayed elevated until the end of the observation period (p < 0.05). Also, the irradiation has induced myocardial degeneration, perivascular and interstitial fibrosis in the heart at the end of six and four months (p < 0.01). The severity and extent of myocardial injury has became more evident at the end of six month (p < 0.05). At ultrastructural level, prominent changes have been observed in the capillary endothelial and myocardial cells. Conclusion: Our findings suggest that the reduced rest myocardial perfusion, occuring months after the radiation, indicates a serious myocard tissue damage which is characterized by myocardial degeneration and fibrosis. (orig.)

  2. Myocardial perfusion alterations observed months after radiotherapy are related to the cellular damage

    International Nuclear Information System (INIS)

    Dogan, I.; Sonmez, B.; Sezen, O.; Zengin, A.Y.; Bahat, Z.; Yenilmez, E.; Yulug, E.; Abidin, I.

    2010-01-01

    Myocardial perfusion scintigraphy (MPS) is one of the widely used tools to follow developing radiation-induced heart disease (RIHD). But the clinical significance of MPS defects has not been fully understood. We have investigated the biodistribution alterations related to perfusion defects following radiotherapy (RT) and showed coexisting morphological changes. Animals, methods: A total of 18 Wistar rats were divided into three groups (1 control and 2 irradiated groups). A single cardiac 20 Gy radiation dose was used to induce long term cardiac defects. Biodistribution studies with technetium ( 99m Tc) sestamibi and histological evaluations were performed 4 and 6 months after irradiation. The percent radioactivity (%ID/g) was calculated for each heart. For determination of the myocardial damage, positive apoptotic cardiomyocytes, myocardial cell degeneration, myocardial fibrosis, vascular damage and ultrastructural structures were evaluated. Results: Six months after treatment, a significant drop of myocardial uptake was observed (p < 0.05). Irradiation-induced apoptosis rose within the first 4 months after radiation treatment and were stayed elevated until the end of the observation period (p < 0.05). Also, the irradiation has induced myocardial degeneration, perivascular and interstitial fibrosis in the heart at the end of six and four months (p < 0.01). The severity and extent of myocardial injury has became more evident at the end of six month (p < 0.05). At ultrastructural level, prominent changes have been observed in the capillary endothelial and myocardial cells. Conclusion: Our findings suggest that the reduced rest myocardial perfusion, occuring months after the radiation, indicates a serious myocard tissue damage which is characterized by myocardial degeneration and fibrosis. (orig.)

  3. Imaging of ventilation/perfusion ratio by gated regional spirometry

    International Nuclear Information System (INIS)

    Touya, J.J.; Jones, J.P.; Price, R.R.; Patton, J.A.; Erickson, J.J.; Rollo, F.D.

    1981-01-01

    Gated 133 Xe images of patients rebreathing into a closed system can provide images of the distribution of lung volumes, ventilation and specific ventilation. These have been shown to be accurate, precise, and do not require unusually sophisticated equipment or skills. A mathematical transformation is used to correct the images for lung movement, which does not alter the total number of counts in the image. Perfusion images are gated to remove motion blurring but not transformed. Ventilation/perfusion images showing the distribution of V/Q ratio are then generated from the individual ventilation and perfusion images. (author)

  4. Lung perfusion and ventilation scintigraphy in pre- and postoperative diagnostics

    International Nuclear Information System (INIS)

    Sandrock, D.; Munz, D.L.

    1998-01-01

    Lung perfusion (Tc-99m labeled albumin particles) and ventilation (Xe-133 gas) are used prior to thoracic surgery in order to evaluate changes in perfusion and ventilation due to the underlying diseases. Furthermore, perfusion scintigraphy allows combined with spirometry the prediction of the postinterventional vital capacity and the forced expiratory volume in 1 s. The correlation coefficient for this procedure compared with values measured postoperatively are in the range of 0.8. The method allows the assessment of operability in terms of postinterventional function. (orig.) [de

  5. 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

  6. Simultaneous determination of left ventricular perfusion and function

    International Nuclear Information System (INIS)

    Gremillet, E.; Champailler, A.; Esquerre, J.P.; Ouhayoun, E.; Coca, F.; Furber, A.; Le Jeune, J.J.

    1997-01-01

    Myocardial perfusion scintigraphy is a very useful tool for the diagnosis and prognosis of coronary artery disease. The evaluation of left ventricular function during stress testing in also very useful to determine the prognosis of coronary artery disease. This chapter highlights three different imaging methods to assess left ventricular function and myocardial perfusion/ The first one consists of sequential dual isotope myocardial SPECT with ECG-gating. The second concerns magnetic resonance imaging and the third explores first pass exercise ventriculography and myocardial perfusion scintigraphy simultaneously evaluated by means of 99m Tc-sestamibi. (authors)

  7. 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

  8. Dynamic perfusion CT: Optimizing the temporal resolution for the calculation of perfusion CT parameters in stroke patients

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. 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

  10. 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.

  11. 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

  12. A Unifying model of perfusion and motion applied to reconstruction of sparsely sampled free-breathing myocardial perfusion MRI

    DEFF Research Database (Denmark)

    Pedersen, Henrik; Ólafsdóttir, Hildur; Larsen, Rasmus

    2010-01-01

    The clinical potential of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is currently limited by respiratory induced motion of the heart. This paper presents a unifying model of perfusion and motion in which respiratory motion becomes an integral part of myocardial perfusion...... quantification. Hence, the need for tedious manual motion correction prior to perfusion quantification is avoided. In addition, we demonstrate that the proposed framework facilitates the process of reconstructing DCEMRI from sparsely sampled data in the presence of respiratory motion. The paper focuses primarily...... on the underlying theory of the proposed framework, but shows in vivo results of respiratory motion correction and simulation results of reconstructing sparsely sampled data....

  13. Metabolism in the isolated rat heart: comparison of 125I-BMIPP with 125I-IPPA

    International Nuclear Information System (INIS)

    Chen Shaoliang; Cheng Aiping; Xu Lanwen; Qiao Weiwei

    2008-01-01

    Objective: The fatty acid metabolism in myocardium is recently one of the most interesting subjects in nuclear cardiology. The purpose of this study was to clarify the metabolic fate of 125 I-labeled 15-(p-iodophenyl)-3-(R, S)-methyl-pentadecanoic acid ( 125 I-BMIPP) and 15-(p-[ 125 I] iodophenyl) pentadecanoic acid ( 125 I-IPPA) by means of isolated rat hearts. Methods: Ten isolated rat hearts were prepared and perfused with 125 I-BMIPP (5 rats) or 125 I-IPPA (5 rats) for 3 h following a basic perfusion of 30 min. After perfusion, the radioactivity in the recirculated buffer was measured. The metabolites in the buffer were then extracted and analyzed using high performance liquid chromatography (HPLC) and thin-layer chromatography (TLC). Results: At the beginning (5 rain) of 125 I-BMIPP perfusion, the main radioactive peak appeared on HPLC at 37 min, which remained after 3 h perfusion. Several small peaks eluting were found before the parent peak at 30, 26, 21, 16, 12 and 9 min, respectively. At the beginning (5 min) of 125 I-IPPA perfusion, the main peak appeared on HPLC at 33 min, which disappeared after 3 h. Conclusions: 125 I-BMIPP strongly inhibited beta-oxidation, therefore appeared suitable for myocardial metabolic imaging. 125 I-IPPA was metabolized rapidly. (authors)

  14. 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.)

  15. Pulmonary ventilation and perfusion imaging with dual-energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Thieme, Sven F. [Klinikum Grosshadern, Department of Clinical Radiology, Ludwig Maximilians University, Muenchen (Germany); Klinikum Grosshadern, Institut fuer Klinische Radiologie, LMU Muenchen, Muenchen (Germany); Hoegl, Sandra; Fisahn, Juergen; Irlbeck, Michael [Klinikum Grosshadern, Department of Anesthesiology, Ludwig Maximilians University, Muenchen (Germany); Nikolaou, Konstantin; Maxien, Daniel; Reiser, Maximilian F.; Becker, Christoph R.; Johnson, Thorsten R.C. [Klinikum Grosshadern, Department of Clinical Radiology, Ludwig Maximilians University, Muenchen (Germany)

    2010-12-15

    To evaluate the feasibility of dual-energy CT (DECT) ventilation imaging in combination with DE perfusion mapping for a comprehensive assessment of ventilation, perfusion, morphology and structure of the pulmonary parenchyma. Two dual-energy CT acquisitions for xenon-enhanced ventilation and iodine-enhanced perfusion mapping were performed in patients under artificial respiration. Parenchymal xenon and iodine distribution were mapped and correlated with structural or vascular abnormalities. In all datasets, image quality was sufficient for a comprehensive image reading of the pulmonary CTA images, lung window images and pulmonary functional parameter maps and led to expedient results in each patient. With dual-source CT systems, DECT of the lung with iodine or xenon administration is technically feasible and makes it possible to depict the regional iodine or xenon distribution representing the local perfusion and ventilation. (orig.)

  16. Pulmonary ventilation and perfusion scintigraphy in patients with bronchial asthma

    International Nuclear Information System (INIS)

    Ono, Seiji; Hoshi, Hiroaki; Watanabe, Katsushi.

    1988-01-01

    Pulmonary ventilation and perfusion scan using Xe-133 gas and Tc-99m MAA were performed in 18 patients with bronchial asthma to evaluate the regional pulmonary function. The scintigraphic findings were compared with the results of the auscultation and the conventional pulmonary functioning examination (%FVC, %FEV 1.0 ). Ventilation image showed abnormality in 12 (70.6%) out of the asymptomatic 17 patients and perfusion image showed abnormality in 7 (41.2%) out of 17 patients. These 7 patients with abnormality on perfusion image all showed abnormality on ventilation image. The grade of abnormality in scintigraphic findings was compatible with the values of %FVC and %FEV 1.0 . In conclusion Xe-133 ventilation and Tc-99m MAA perfusion scan were useful procedures to estimate the pulmonary function of patients with bronchial asthma. (author)

  17. CT perfusion scanning of the brain in stroke and beyond

    International Nuclear Information System (INIS)

    Riedel, Christian

    2011-01-01

    CT perfusion scanning (CTP) allows for quantitative analysis of cerebral blood flow (CBF) and cerebral blood volume (CBV). Until recently, it was only possible to study brain perfusion parameters in a small stack of CT-slices close to the skull base. With the introduction of multidetector CT scanners with 64 and more detector rows it has become possible to assess perfusion of the entire brain. An optimal choice of scanning parameters like the new 'shuttle'-technique combined with a well adapted regimen for contrast administration is required to guarantee reliable perfusion measurements while still keeping the X-ray dose absorbed by the patient at a minimum. With these techniques, CTP is not only an important modality in the work-up of patients suffering from acute ischemic stroke but can also be valuable in other emergency situations such as in prolonged epileptic seizures or to monitor patients with subacute subarachnoid hemorrhage. (orig.)

  18. Pulmonary perfusion ''without ventilation''

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-12-01

    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.''

  19. Brain perfusion spect imaging with sup 99m Tc-HM-PAO in Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Wenzhong, Song; Xiangtong, Lin [Shanghai Medical Univ. (China). Huashan Hospital

    1991-02-01

    Forty patients with Parkinson's disease were studied using {sup 99m}Tc-HM-PAO brain perfusion SPECT. 62.5% (25 cases) showed abnormal blood perfusion. Among them 55% showed local decreased blood perfusion of cerebral cortex, 22% showed asymmetric decreased blood perfusion in basal gaglia, 10% showed decreased uptake of tracer in cerebellum. The pathophysiologic basis of the abnormality of brain blood perfusion were briefly discussed.

  20. Radiation-induced increase in the release of amino acids by isolated, perfused skeletal muscle

    International Nuclear Information System (INIS)

    Schwenen, M.

    1989-01-01

    Local exposure of the hindquarter of the rat to 15Gy of gamma-radiation resulted, 4-6h after irradiation, in increased release of amino acids by the isolated, perfused hindquarter preparation, 70% of which is skeletal muscle. This increase in release involves not only alanine and glutamine, but also those amino acids not metabolized by muscle and, therefore, released in proportion to their occurrence in muscle proteins. Because metabolic parameters and content of energy-rich phosphate compounds in muscle remain unchanged, it is unlikely that general cellular damage is the underlying cause of the radiation-induced increase in amino acid release. The findings strongly favour the hypothesis that increased availability of amino acids results from enhanced protein break-down in skeletal muscle which has its onset shortly after irradiation. This radiation-induced disturbance in protein metabolism might be one of the pathogenetic factors in the aetiology of radiation myopathy. (author)

  1. Alpha and beta adrenergic effects on metabolism in contracting, perfused muscle

    DEFF Research Database (Denmark)

    Richter, Erik; Ruderman, N B; Galbo, H

    1982-01-01

    The role of alpha- and beta-adrenergic receptor stimulation for the effect of epinephrine on muscle glycogenolysis, glucose- and oxygen uptake and muscle performance was studied in the perfused rat hindquarter at rest and during electrical stimulation (60 contractions/min). Adrenergic stimulation...... was obtained by epinephrine in a physiological concentration (2.4 X 10(-8) M) and alpha- and beta-adrenergic blockade by 10(-5) M phentolamine and propranolol, respectively. Epinephrine enhanced net glycogenolysis during contractions most markedly in slow-twitch red fibers. In these fibers the effect...... was mediated by alpha- as well as by beta-adrenergic stimulation, the latter involving production of cAMP, phosphorylase activation and synthase inactivation. In contrast, in fast-twitch fibers only beta-adrenergic mechanisms were involved in the glycogenolytic effect of epinephrine. Moreover, inactivation...

  2. Transplacental transfer of nitrosodimethylamine in perfused human placenta.

    OpenAIRE

    Annola, K.; Heikkinen, A.T.; Partanen, H.; Woodhouse, H.; Segerback, D.; Vahakangas, K.

    2009-01-01

    Nitrosodimethylamine (NDMA) is a carcinogenic compound present in tobacco smoke and food such as cured meat, smoked fish and beer. The O(6)-methylguanine formed in human cord blood in mothers highly exposed to such products implicates NDMA exposure of the fetus. Dual recirculating human placental perfusion was used to get direct evidence of the transplacental transfer of NDMA and DNA adduct formation in perfused human placenta. Eleven placentas from normal full-term pregnancies were collected...

  3. Automatic extraction of left ventricle in SPECT myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Liu Li; Zhao Shujun; Yao Zhiming; Wang Daoyu

    1999-01-01

    An automatic method of extracting left ventricle from SPECT myocardial perfusion data was introduced. This method was based on the least square analysis of the positions of all short-axis slices pixels from the half sphere-cylinder myocardial model, and used a iterative reconstruction technique to automatically cut off the non-left ventricular tissue from the perfusion images. Thereby, this technique provided the bases for further quantitative analysis

  4. Monitoring Cell Death in Regorafenib-Treated Experimental Colon Carcinomas Using Annexin-Based Optical Fluorescence Imaging Validated by Perfusion MRI.

    Directory of Open Access Journals (Sweden)

    Philipp M Kazmierczak

    Full Text Available To investigate annexin-based optical fluorescence imaging (OI for monitoring regorafenib-induced early cell death in experimental colon carcinomas in rats, validated by perfusion MRI and multiparametric immunohistochemistry.Subcutaneous human colon carcinomas (HT-29 in athymic rats (n = 16 were imaged before and after a one-week therapy with regorafenib (n = 8 or placebo (n = 8 using annexin-based OI and perfusion MRI at 3 Tesla. Optical signal-to-noise ratio (SNR and MRI tumor perfusion parameters (plasma flow PF, mL/100mL/min; plasma volume PV, % were assessed. On day 7, tumors underwent immunohistochemical analysis for tumor cell apoptosis (TUNEL, proliferation (Ki-67, and microvascular density (CD31.Apoptosis-targeted OI demonstrated a tumor-specific probe accumulation with a significant increase of tumor SNR under therapy (mean Δ +7.78±2.95, control: -0.80±2.48, p = 0.021. MRI detected a significant reduction of tumor perfusion in the therapy group (mean ΔPF -8.17±2.32 mL/100 mL/min, control -0.11±3.36 mL/100 mL/min, p = 0.036. Immunohistochemistry showed significantly more apoptosis (TUNEL; 11392±1486 vs. 2921±334, p = 0.001, significantly less proliferation (Ki-67; 1754±184 vs. 2883±323, p = 0.012, and significantly lower microvascular density (CD31; 107±10 vs. 182±22, p = 0.006 in the therapy group.Annexin-based OI allowed for the non-invasive monitoring of regorafenib-induced early cell death in experimental colon carcinomas, validated by perfusion MRI and multiparametric immunohistochemistry.

  5. Mucosal blood flow measurements using laser Doppler perfusion monitoring

    Institute of Scientific and Technical Information of China (English)

    Dag Arne Lihaug Hoff; Hans Gregersen; Jan Gunnar Hatlebakk

    2009-01-01

    Perfusion of individual tissues is a basic physiological process that is necessary to sustain oxygenation and nutrition at a cellular level. Ischemia, or the insufficiency of perfusion, is a common mechanism for tissue death or degeneration, and at a lower threshold, a mechanism for the generation of sensory signalling including pain. It is of considerable interest to study perfusion of peripheral abdominal tissues in a variety of circumstances. Microvascular disease of the abdominal organs has been implicated in the pathogenesis of a variety of disorders, including peptic ulcer disease, inflammatory bowel disease and chest pain. The basic principle of laser Doppler perfusion monitoring (LDPM) is to analyze changes in the spectrum of light reflected from tissues as a response to a beam of monochromatic laser light emitted. It reflects the total local microcirculatory blood perfusion, including perfusion in capillaries, arterioles, venules and shunts. During the last 20-25 years, numerous studies have been performed in different parts of the gastrointestinal (GI) tract using LDPM. In recent years we have developed a multi-modal catheter device which includes a laser Doppler probe, with the intent primarily to investigate patients suffering from functional chest pain of presumed oesophageal origin. Preliminary studies show the feasibility of incorporating LDPM into such catheters for performing physiological studies in the GI tract. LDPM has emerged as a research and clinical tool in preference to other methods; but, it is important to be aware of its limitations and account for them when reporting results.

  6. Perfusion-weighted MR imaging in persistent hemiplegic migraine

    International Nuclear Information System (INIS)

    Mourand, Isabelle; Menjot de Champfleur, Nicolas; Carra-Dalliere, Clarisse; Le Bars, Emmanuelle; Bonafe, Alain; Thouvenot, Eric; Roubertie, Agathe

    2012-01-01

    Hemiplegic migraine is a rare type of migraine that has an aura characterized by the presence of motor weakness, which may occasionally last up to several days, and then resolve without sequela. Pathogenesis of migraine remains unclear and, recently, perfusion-weighted imaging (PWI) has provided a non-invasive method to study hemodynamic changes during acute attacks. Two female patients were admitted in our hospital suffering from prolonged hemiparesis. In both cases, they underwent MRI examination using a 1.5 T magnet including axial diffusion-weighted and perfusion sequences. From each perfusion MRI acquisition two regions of interest were delineated on each hemisphere and, the index of flow, cerebral blood volume, mean transit time, and time to peak were recorded and asymmetry indices from each perfusion parameter were calculated. Perfusion alterations were detected during the attacks. In one case, we observed, after 3 h of left hemiparesia, hypoperfusion of the right hemisphere. In the other case, who presented a familial hemiplegic migraine attack, on the third day of a persistent aura consisting of right hemiplegia and aphasia, PWI revealed hyperperfusion of the left hemisphere. Asymmetry indices for temporal parameters (mean transit time and time to peak) were the most sensitive. These findings resolved spontaneously after the attacks without any permanent sequel or signs of cerebral ischemia on follow-up MRI. PWI should be indicated for patients with migraine attacks accompanied by auras to assess the sequential changes in cerebral perfusion and to better understand its pathogenesis. (orig.)

  7. Role of myocardial perfusion SPECT in asymptomatic diabetic patients

    International Nuclear Information System (INIS)

    Cho, I.; Chun, K.; Won, K.; Lee, H.; Park, J.; Shin, D.; Kim, Y.; Shim, B.; Lee, J.

    2002-01-01

    Purpose: It is important that early diagnosis and treatment of coronary artery disease in diabetic patients, but there are few reports on the prevalence of stress-induced myocardial perfusion abnormalities and the rates of cardiac event in patients with type 2 diabetes. We evaluated the scan findings on gated myocardial perfusion SPECT in asymptomatic diabetic patients. Methods: We performed pharmacological stress test and gated perfusion SPECT in 69 diabetic patients without cardiovascular symptom (mean age: 65 year, male 31 and female 38). Patients underwent two-day imaging protocol and stress study was performed injection of Tc-99m MIBI during adenosine infusion. We followed up these patients by reviewing medical records. Results: Fifty-two of 69 patients (74.5%) showed normal scan findings and 17 patients (24.6%) showed reversible or fixed perfusion defects. Three of 52 patients with normal scan findings showed decreased LV ejection fraction and decreased wall motion. Twenty-three patients with normal scan findings were possible to follow up for more than 1yr (mean time: 18.3±3.3 mo.) and they all had no cardiac event. Three patients with reversible perfusion defects were performed coronary angioplasty. Conclusion: Myocardial perfusion SPECT is a noninvasive method and maybe useful in early diagnosis and predicting prognosis in diabetic patients

  8. Impairment of myocardial perfusion in children with sickle cell disease

    International Nuclear Information System (INIS)

    Maunoury, C.; Acar, P.; Montalembert, M. de

    2003-01-01

    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)

  9. CT Perfusion Characteristics Identify Metastatic Sites in Liver

    Directory of Open Access Journals (Sweden)

    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.

  10. 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.

  11. Job analysis and student assessment tool: perfusion education clinical preceptor.

    Science.gov (United States)

    Riley, Jeffrey B

    2007-09-01

    The perfusion education system centers on the cardiac surgery operating room and the perfusionist teacher who serves as a preceptor for the perfusion student. One method to improve the quality of perfusion education is to create a valid method for perfusion students to give feedback to clinical teachers. The preceptor job analysis consisted of a literature review and interviews with preceptors to list their critical tasks, critical incidents, and cognitive and behavioral competencies. Behaviorally anchored rating traits associated with the preceptors' tasks were identified. Students voted to validate the instrument items. The perfusion instructor rating instrument with a 0-4, "very weak" to "very strong" Likert rating scale was used. The five preceptor traits for student evaluation of clinical instruction (SECI) are as follows: The clinical instructor (1) encourages self-learning, (2) encourages clinical reasoning, (3) meets student's learning needs, (4) gives continuous feedback, and (5) represents a good role model. Scores from 430 student-preceptor relationships for 28 students rotating at 24 affiliate institutions with 134 clinical instructors were evaluated. The mean overall good preceptor average (GPA) was 3.45 +/- 0.76 and was skewed to the left, ranging from 0.0 to 4.0 (median = 3.8). Only 21 of the SECI relationships earned a GPA SECI are methods to provide valid information to improve the quality of a perfusion education program.

  12. Perfusion-weighted MR imaging in persistent hemiplegic migraine

    Energy Technology Data Exchange (ETDEWEB)

    Mourand, Isabelle; Menjot de Champfleur, Nicolas; Carra-Dalliere, Clarisse; Le Bars, Emmanuelle; Bonafe, Alain; Thouvenot, Eric [Hopital Gui de Chauliac, Service de Neuroradiologie, Montpellier (France); Roubertie, Agathe [Hopital Gui de Chauliac, Service de Neuropediatrie, Montpellier (France)

    2012-03-15

    Hemiplegic migraine is a rare type of migraine that has an aura characterized by the presence of motor weakness, which may occasionally last up to several days, and then resolve without sequela. Pathogenesis of migraine remains unclear and, recently, perfusion-weighted imaging (PWI) has provided a non-invasive method to study hemodynamic changes during acute attacks. Two female patients were admitted in our hospital suffering from prolonged hemiparesis. In both cases, they underwent MRI examination using a 1.5 T magnet including axial diffusion-weighted and perfusion sequences. From each perfusion MRI acquisition two regions of interest were delineated on each hemisphere and, the index of flow, cerebral blood volume, mean transit time, and time to peak were recorded and asymmetry indices from each perfusion parameter were calculated. Perfusion alterations were detected during the attacks. In one case, we observed, after 3 h of left hemiparesia, hypoperfusion of the right hemisphere. In the other case, who presented a familial hemiplegic migraine attack, on the third day of a persistent aura consisting of right hemiplegia and aphasia, PWI revealed hyperperfusion of the left hemisphere. Asymmetry indices for temporal parameters (mean transit time and time to peak) were the most sensitive. These findings resolved spontaneously after the attacks without any permanent sequel or signs of cerebral ischemia on follow-up MRI. PWI should be indicated for patients with migraine attacks accompanied by auras to assess the sequential changes in cerebral perfusion and to better understand its pathogenesis. (orig.)

  13. Myocardial perfusion SPECT imaging in patients with myocardial bridging

    International Nuclear Information System (INIS)

    Fang Wei; Qiu Hong; Yang Weixian; Wang Feng; He Zuoxiang

    2008-01-01

    Objective: Stress myocardial perfusion SPECT imaging was used to assess myocardial ischemia in patients with myocardial bridging. Methods: Ninety-six patients with myocardial bridging of the left anterior descending artery documented by coronary angiography were included in this study. All under- went exercise or pharmacological stress myocardial perfusion SPECT assessing myocardial ischemia. None had prior myocardial infarction. One year follow-up by telephone interview was performed in all patients. Results The mean stenotic severity of systolic phase on angiography was (65 ± 19)%. In the SPECT study, 20 of 96 (20.8%) patients showed abnormal perfusion. This percentage was significantly higher than that of stress electrocardiogram (ECG). The higher positive rate of SPECT perfusion images was showed in the group of patients with severe systolic narrowing (≥75%) than that with mild-to-moderate systolic narrowing (50% vs 6.3%, P<0.001). The prevalence of abnormal image was significantly higher in ELDERLY PEOPLE; patients with STT change on rest ECG than in those with normal rest ECG (54.2% vs 9.7%, P<0.001). During follow-up, one patient with abnormal SPECT perfusion image sustained angina and accepted percutaneous coronary intervention, and no cardiac event occurred in patients with normal images. Conclusions: Stress myocardial perfusion SPECT imaging can be used effectively for assessing myocardial ischemia and has potential prognostic value for patients with myocardial bridging. (authors)

  14. The natural history of misery perfusion in positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Shinji; Fujii, Kiyotaka; Matsushima, Toshio; Fukui, Masashi; Sadoshima, Shouzou; Kuwabara, Yasuo (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

    1992-03-01

    This report reviews the natural courses of misery perfusion in 5 patients with atherosclerotic cerebrovascular occlusion diseases. Cases 1 showed partial improvement and Case 2 showed deterioration of misery perfusion on positron emission tomography (PET). These 2 patients did not show any clinical changes during the follow-up periods. Case 3 showed remarkable improvement of misery perfusion during the 2-year follow-ups, but his neurological condition worsened. The EC-IC bypass improved both in PET and clinical symptoms. Case 4 had a stroke at the region of misery perfusion in PET. Case 5 had a lacunar infarction 2 years after the EC-IC bypass on the opposite side. PET taken one month before the stroke did not show any signs of hypoperfusion in the area of the lacunar infarction. Misery perfusion seems not to be a static but a dynamic condition that can develop into cerebral infarction by some hemodynamic stresses. Cerebral cortical or lobar infarction may occur in the region of severe misery perfusion. EC-IC bypass may prevent impending infarction of the cerebral cortex by improving the regional cerebral blood flow. However, EC-CI bypass will not prevent the lacunar infarction of the basal ganglia or internal capsule. (author).

  15. Radioimmunoassay of met-enkephalin in microdissected areas of paraformaldehyde-fixed rat brain

    International Nuclear Information System (INIS)

    Correa, F.M.A.; Saavedra, J.M.

    1984-01-01

    The effects were studied of various sample preparation procedures on rat brain met-enkephalin content, measured by radioimmunoassay. Whole brain met-enkephalin content of rats killed by decapitation followed by immediate tissue freezing was similar to that of rats killed by microwave irradiation and to those of rats anesthetized with pentobarbital or halothane before killing, whether previously perfused with paraformaldehyde or not. In contrast, a decrease (up to 80%) in met-enkephalin concentrations was observed when brain samples were frozen and thawed to mimic the procedure utilized in the ''punch'' technique for analysis of discrete brain nuclei. This decrease was totally prevented by paraformaldehyde perfusion of the brain prior to sacrifice. Brain perfusion did not alter the amount of immunoassayable met-enkephalin extracted from tissue or its profile after Sephadex chromatography. Paraformaldehyde perfusion results in better morphological tissue preservation and facilitates the ''punch'' dissecting technique. Paraformaldehyde perfusion may be the procedure of choice for the measurement of neuropeptides in specific brain nuclei dissected by the ''punch'' technique

  16. Xeno- and auto-perfusion of rabbit kidney. Machine perfusion with blood at 37 degrees C

    DEFF Research Database (Denmark)

    Jørgensen, K A; Kemp, E; Barfort, P

    1985-01-01

    damage, exudation, and IgG deposits along the basement membrane of the glomerular capillaries were the discriminative features of the xenoperfusion. In these experiments, we were unable to demonstrate any major role of platelets in the process leading to decreased blood flow.......Five rabbit kidneys were perfused with human blood and another five with their own blood in a re-circulating oxygenated system at 37 degrees C. The flow decreased to 2 ml/min. within 30 min. in all xenoperfusions, while none of the autoperfused had decreased to this level by 60 min. Endothelial...

  17. Cerebral perfusion gammagraphy in neurology and neurosurgery

    International Nuclear Information System (INIS)

    Cardenas, Rene; Duran de Cardenas, Rosalia

    1998-01-01

    This paper describes six methods for measuring rCBF: 1) PET through 77 Kr, 15 O-water, 18 F-antipirine, 18 F-methane and 11 C-alcohols, 2) Wash measure of 133 Xe through SPECT or multidetectors, 3) CT contrasted through xenon, 4) planar gammagraphy or SPECT through 123 I-IMP or 123 I-HIPDM, 5) planar gammagraphy or radioisotopic tomography (SPECT) through 201 Tl-dietiltiocarbamate, and 6) planar gammagraphy or SPECT through 99m Tc lipofilics complex, 99m Tc-HMPAO and 99m Tc-ECD. They have been used for rCBF, , 133 Xe, 123 I-IMP 99m Tc-HMPAO studies, the two last ones are been used at the moment, the film performance is around 0.7 to 1.1 cm. The most useful radioisotopic techniques for gammagraphic study of cerebral perfusion have used HMPAO and 131 I-IMP labelled with 99m Tc

  18. Placental perfusion in 3rd trimester pregnancy

    Science.gov (United States)

    Sitepu, M.; Syahriza, A.; Sibuea, D.; Hanafiah, T. M.

    2018-03-01

    The placenta is an organ for transmitting nutrition and oxygen to thefetus; it means if there is a defect in the placenta could make growth restriction to the fetus, even death. Uterine artery flow escalated since the halfway point of the pregnancy or the complete trophoblast invasion of spiralis artery, and keep going in every week. 3D power Doppler examination on placenta could show the uterineplacenta circulation and fetoplacental at once so could give themore accurate result. A cross-sectional study in RSUP HAM and theprivate specialist clinic was conducted in 100 pregnant samples with 28-40 week gestational age, exact last menstrual period date, and no underlying disease to examine the alteration of placental perfusion by gestationalage and placental location. There was a correlation between VI and VFI in placenta toward umbilical artery flow, but no correlation in FI. The placental location also plays a role in interval blood flow, especially FI and VFI, it means the VFI hold the strongest correlation in both ways.

  19. Myocardial perfusion in silent myocardial ischemia

    International Nuclear Information System (INIS)

    Narita, Michihiro; Kurihara, Tadashi; Murano, Kenichi; Usami, Masahisa

    1989-01-01

    To investigate myocardial perfusion in silent myocardial ischemia, we performed exercise stress myocardial tomography with thallium-201 (Tl) in 85 patients with coronary artery disease (CAD). Exercise stress myocardial tomography was obtained both immediately after exercise and three hours later. Patients were classified into two groups according to the presence (Symptomatic Group, n=36) or absence (Silent Group, n=49) of chest pain during exercise stress. Clinical features (age, gender and history of myocardial infarction) and arteriographically determined severity of CAD were the same in both groups. The extent of myocardial ischemia (% Ischemia) estimated by exercise stress myocardial tomography was the same in each group (30±10 % in Silent Group, 28±12 % in Symptomatic Group, NS). The severity of exercise-induced myocardial ischemia was expressed as a minimal value of myocardial Tl washout rate (minimal WOR) of each patient. Although exercise heart rate was identical in both groups, minimal WOR in Silent Group was significantly higher than that of Symptomatic Group (4±10% vs -16±14%, p<0.001). The study in patients who exhibited both silent and symptomatic ischemia showed the same results. These findings suggest that the severity of ischemia is a fundamental factor in determining the presence or absence of pain during exercise induced ischemia. (author)

  20. 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)

  1. Altered carnitine transport in pressure-overload hypertrophied rat hearts

    International Nuclear Information System (INIS)

    O'Rourke, B.; Foster, K.; Reibel, D.K.

    1986-01-01

    The authors have previously observed reduced carnitine levels in hypertrophied hearts of rats subjected to aortic constriction. In an attempt to determine the mechanism for reduced myocardial carnitine content, carnitine transport was examined in isolated perfused hearts. Hearts were excised from sham-operated and aortic-constricted rats 3 weeks following surgery and perfused at 60 mm Hg aortic pressure with buffer containing various concentrations of L- 14 C-carnitine. Carnitine uptake by control and hypertrophied hearts was linear throughout 30 minutes of perfusion with 40 μM carnitine. Total carnitine uptake was significantly reduced by 25% in hypertrophied hearts at each time point examined. The reduction in uptake by hypertrophied hearts was also evident when hearts were perfused with 100 or 200 μM carnitine. When 0.05 mM mersalyl acid was included in the buffer to inhibit the carrier-mediated component of transport, no difference in carnitine uptake was observed indicating that the transport of carnitine by diffusion was unaltered in the hypertrophied myocardium. Carrier-mediated carnitine uptake (total uptake - uptake by diffusion) was significantly reduced by approximately 40% in hypertrophied hearts at all concentrations examined. Thus, the reduction in carnitine content in the pressure-overload hypertrophied rat heart appears to be due to a reduction in carrier-mediated carnitine uptake by the heart

  2. The advantage of high relaxivity contrast agents in brain perfusion

    International Nuclear Information System (INIS)

    Cotton, F.; Hermier, M.

    2006-01-01

    Accurate MRI characterization of brain lesions is critical for planning therapeutic strategy, assessing prognosis and monitoring response to therapy. Conventional MRI with gadolinium-based contrast agents is useful for the evaluation of brain lesions, but this approach primarily depicts areas of disruption of the blood-brain barrier (BBB) rather than tissue perfusion. Advanced MR imaging techniques such as dynamic contrast agent-enhanced perfusion MRI provide physiological information that complements the anatomic data available from conventional MRI. We evaluated brain perfusion imaging with gadobenate dimeglumine (Gd-BOPTA, MultiHance; Bracco Imaging, Milan, Italy). The contrast-enhanced perfusion technique was performed on a Philips Intera 1.5-T MR system. The technique used to obtain perfusion images was dynamic susceptibility contrast-enhanced MRI, which is highly sensitive to T2* changes. Combined with PRESTO perfusion imaging, SENSE is applied to double the temporal resolution, thereby improving the signal intensity curve fit and, accordingly, the accuracy of the derived parametric images. MultiHance is the first gadolinium MR contrast agent with significantly higher T1 and T2 relaxivities than conventional MR contrast agents. The higher T1 relaxivity, and therefore better contrast-enhanced T1-weighted imaging, leads to significantly improved detection of BBB breakdown and hence improved brain tumor conspicuity and delineation. The higher T2 relaxivity allows high-quality T2*-weighted perfusion MRI and the derivation of good quality relative cerebral blood volume (rCBV) maps. We determined the value of MultiHance for enhanced T2*-weighted perfusion imaging of histologically proven (by surgery or stereotaxic biopsy) intraaxial brain tumors (n=80), multiple sclerosis lesions (n=10), abscesses (n=4), neurolupus (n=15) and stroke (n=16). All the procedures carried out were safe and no adverse events occurred. The acquired perfusion images were of good quality in

  3. In vivo evaluation of potential Tc-99m brain perfusion agents using brain uptake index determination and biodistribution

    International Nuclear Information System (INIS)

    Rajeckas, A.J.; Watson, A.D.; Subramanyam, V.; Williams, S.J.; Belonga, B.Q.; de Nemours, E.I.D.

    1985-01-01

    In order to evaluate the pharmacological properties of various Tc-99m complexes as potential brain perfusion agents, the authors have employed both biodistribution techniques as well as modified Oldendorf procedure for the determination of the brain uptake index (BUI). A typical BUI determination involves the coinjection of 1 microcurie each of I-125 iodoantipyrine and the Tc-99m complex into the left carotid artery of a pentabarbitol anesthetized rat. The animal is sacrificed at 10 seconds; the right and left hemispheres of the brain are removed and counted for each isotope in a gamma well counter. Biodistribution studies are performed using tail-vein injections in unanesthetized rats. In the evaluation of a series of Tc-99m N/sub 2/S/sub 2/ (diamine dithiol) complexes, they have observed that compounds with a low BUI (less than 50) also have a low brain concentration (less than 1% ID) at 30 seconds post injection

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

    Science.gov (United States)

    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.

  5. Correlation of perfusion MRI and 18F-FDG PET imaging biomarkers for monitoring regorafenib therapy in experimental colon carcinomas with immunohistochemical validation.

    Directory of Open Access Journals (Sweden)

    Ralf S Eschbach

    Full Text Available To investigate a multimodal, multiparametric perfusion MRI / 18F-fluoro-deoxyglucose-(18F-FDG-PET imaging protocol for monitoring regorafenib therapy effects on experimental colorectal adenocarcinomas in rats with immunohistochemical validation.Human colorectal adenocarcinoma xenografts (HT-29 were implanted subcutaneously in n = 17 (n = 10 therapy group; n = 7 control group female athymic nude rats (Hsd:RH-Foxn1rnu. Animals were imaged at baseline and after a one-week daily treatment protocol with regorafenib (10 mg/kg bodyweight using a multimodal, multiparametric perfusion MRI/18F-FDG-PET imaging protocol. In perfusion MRI, quantitative parameters of plasma flow (PF, mL/100 mL/min, plasma volume (PV, % and endothelial permeability-surface area product (PS, mL/100 mL/min were calculated. In 18F-FDG-PET, tumor-to-background-ratio (TTB was calculated. Perfusion MRI parameters were correlated with TTB and immunohistochemical assessments of tumor microvascular density (CD-31 and cell proliferation (Ki-67.Regorafenib significantly (p<0.01 suppressed PF (81.1±7.5 to 50.6±16.0 mL/100mL/min, PV (12.1±3.6 to 7.5±1.6% and PS (13.6±3.2 to 7.9±2.3 mL/100mL/min as well as TTB (3.4±0.6 to 1.9±1.1 between baseline and day 7. Immunohistochemistry revealed significantly (p<0.03 lower tumor microvascular density (CD-31, 7.0±2.4 vs. 16.1±5.9 and tumor cell proliferation (Ki-67, 434.0 ± 62.9 vs. 663.0 ± 98.3 in the therapy group. Perfusion MRI parameters ΔPF, ΔPV and ΔPS showed strong and significant (r = 0.67-0.78; p<0.01 correlations to the PET parameter ΔTTB and significant correlations (r = 0.57-0.67; p<0.03 to immunohistochemical Ki-67 as well as to CD-31-stainings (r = 0.49-0.55; p<0.05.A multimodal, multiparametric perfusion MRI/PET imaging protocol allowed for non-invasive monitoring of regorafenib therapy effects on experimental colorectal adenocarcinomas in vivo with significant correlations between perfusion MRI parameters and 18F

  6. Scintigraphic and MR perfusion imaging in preoperative evaluation for lung volume reduction surgery. Pilot study results

    International Nuclear Information System (INIS)

    Johkoh, Takeshi; Mueller, N.L.; Kavanagh, P.V

    2000-01-01

    To compare MR perfusion imaging with perfusion scintigraphy in the evaluation of patients with pulmonary emphysema being considered for lung volume reduction surgery. Six patients with pulmonary emphysema and two normal individuals were evaluated by MR perfusion imaging, perfusion scintigraphy, and selective bilateral pulmonary angiography. MR images were obtained with an enhanced fast gradient recalled echo with three-dimensional Fourier transformation technique (efgre 3D) (6.3/1.3; flip angle, 30 deg C; field of view, 45-48 cm; matrix, 256 x 160). The presence or absence of perfusion defects in each segment was evaluated by two independent observers. Using angiography as the gold standard, the sensitivity, specificity, and accuracy of MR perfusion imaging in detecting focal perfusion abnormalities were 90%, 87%, and 89%, respectively, while those of perfusion scintigraphy were 71%, 76%, and 71%, respectively. The diagnostic accuracy of MR perfusion imaging was significantly higher than that of scintigraphy (p<0.001, McNemar test). There was good agreement between two observers for MR perfusion imaging (kappa statistic, 0.66) and only moderate agreement for perfusion scintigraphy (kappa statistic, 0.51). MR perfusion imaging is superior to perfusion scintigraphy in the evaluation of pulmonary parenchymal perfusion in patients with pulmonary emphysema. (author)

  7. [Intratympanic corticosteroid perfusion in the therapy of Meniere's disease].

    Science.gov (United States)

    Sanković-Babić, Snezana; Kosanović, Rade; Ivanković, Zoran; Babac, Snezana; Tatović, Milica

    2014-01-01

    Over the last two decades the intratympanic perfusion of corticosteroids has been used as a minimally invasive surgical therapy of Meniere's disease. According to experimental studies the antiinflammatory, immunoprotective, antioxidant and neuroprotective role of the locally perfused corticosteroids was noticed in the inner ear structures. The recovery of action potentials in the cells of the Corti organ was confirmed as well as a decreased expression of aquaporine-1, a glycoprotein responsible for labyrinth hydrops and N and K ions derangement. The study showed results of intratympanic perfusion therapy with dexamethasone in patients with retractable Meniere's disease who are resistant to conservative treatment. Single doses of 4 mg/ml dexamethasone were given intratympanically in 19 patients with retractable Meniere's disease. Six single successive doses of dexamethasone were administered in the posteroinferior quadrant of the tympanic membrane. Follow-up of the patients was conducted by using a clinical questionnaire a month after completed perfusion series as well as on every third month up to one year. One month after completed first course of perfusions, in 78% of patients, vertigo problems completely ceased or were markedly reduced. The recovery of hearing function was recorded in 68% and marked tinnitus reduction in 84% of patients. After a year of follow-up, in 63% of patients the reduction of vertigo persisted, while hearing function was satisfactory in 52%. Tinitus reduction was present in 73% of patients. Intratympanic perfusion of dexamethasone in patients with Meniere's disease is a minimally invasive therapeutic method that contributes to the reduction of the intensity of vertigo recurrent attacks, decrease of the intensity of tinnitus and improvement of the average hearing threshold. Patients with chronic diseases and Meniere's disease who are contraindicted for systemic administration of cortocosteroids (hypertension, diabetes, glaucoma, peptic

  8. Evaluation of Microvascular Perfusion and Resuscitation after Severe Injury.

    Science.gov (United States)

    Lee, Yann-Leei L; Simmons, Jon D; Gillespie, Mark N; Alvarez, Diego F; Gonzalez, Richard P; Brevard, Sidney B; Frotan, Mohammad A; Schneider, Andrew M; Richards, William O

    2015-12-01

    Achieving adequate perfusion is a key goal of treatment in severe trauma; however, tissue perfusion has classically been measured by indirect means. Direct visualization of capillary flow has been applied in sepsis, but application of this technology to the trauma population has been limited. The purpose of this investigation was to compare the efficacy of standard indirect measures of perfusion to direct imaging of the sublingual microcirculatory flow during trauma resuscitation. Patients with injury severity scores >15 were serially examined using a handheld sidestream dark-field video microscope. In addition, measurements were also made from healthy volunteers. The De Backer score, a morphometric capillary density score, and total vessel density (TVD) as cumulative vessel area within the image, were calculated using Automated Vascular Analysis (AVA3.0) software. These indices were compared against clinical and laboratory parameters of organ function and systemic metabolic status as well as mortality. Twenty severely injured patients had lower TVD (X = 14.6 ± 0.22 vs 17.66 ± 0.51) and De Backer scores (X = 9.62 ± 0.16 vs 11.55 ± 0.37) compared with healthy controls. These scores best correlated with serum lactate (TVD R(2) = 0.525, De Backer R(2) = 0.576, P trauma patients, and seems to provide real-time assessment of microcirculatory perfusion. This study suggests that in severe trauma, many indirect measurements of perfusion do not correlate with microvascular perfusion. However, visualized perfusion deficiencies do reflect a shift toward anaerobic metabolism.

  9. Novel synthesis and initial preclinical evaluation of (18)F-[FDG] labeled rhodamine: a potential PET myocardial perfusion imaging agent.

    Science.gov (United States)

    AlJammaz, Ibrahim; Al-Otaibi, Basim; AlHindas, Hussein; Okarvi, Subhani M

    2015-10-01

    Myocardial perfusion imaging is one of the most commonly performed investigations in nuclear medicine studies. Due to the clinical importance of [(18)F]-fluoro-2-deoxy-D-glucose ([(18)F]-FDG) and its availability in almost every PET center, a new radiofluorinated [(18)F]-FDG-rhodamine conjugate was synthesized using [(18)F]-FDG as a prosthetic group. In a convenient and simple one-step radiosynthesis, [(18)F]-FDG-rhodamine conjugate was prepared in quantitative radiochemical yields, with total synthesis time of nearly 20 min and radiochemical purity of greater than 98%, without the need for HPLC purification, which make these approaches amenable for automation. Biodistribution studies in normal rats at 60 min post-injection demonstrated a high uptake in the heart (>11% ID/g) and favorable pharmacokinetics. Additionally, [(18)F]-FDG-rhodamine showed an extraction value of 27.63%±5.12% in rat hearts. These results demonstrate that [(18)F]-FDG-rhodamine conjugate may be useful as an imaging agent for the positron emission tomography evaluation of myocardial perfusion. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Retrospective respiratory triggering renal perfusion MRI

    Energy Technology Data Exchange (ETDEWEB)

    Attenberger, Ulrike I.; Michaely, Henrik J.; Schoenberg, Stefan O. (Dept. of Clinical Radiology and Nuclear Medicine, Univ. Hospital Mannheim, Univ. of Heidelberg, Mannheim (Germany)), e-mail: ulrike.attenberger@medma.uni-heidelberg.de; Sourbron, Steven P. (Div. of Medical Physics, Univ. of Leeds, Leeds (United Kingdom)); Reiser, Maximilian F. (Dept. of Clinical Radiology, Univ. Hospitals Munich, Grosshadern, Ludwig-Maximilians-Univ., Munich (Germany))

    2010-12-15

    Background: Artifacts of respiratory motion are one of the well-known limitations of dynamic contrast-enhanced MRI (DCE-MRI) of the kidney. Purpose: To propose and evaluate a retrospective triggering approach to minimize the effect of respiratory motion in DCE-MRI of the kidney. Material and Methods: Nine consecutive patients underwent renal perfusion measurements. Data were acquired with a 2D saturation-recovery TurboFLASH sequence. In order to test the dependence of the results on size and location of the manually drawn triggering regions of interest (ROIs), three widely differing triggering regions were defined by one observer. Mean value, standard deviation, and variability of the renal function parameters plasma flow (FP), plasma volume (VP), plasma transit time (TP), tubular flow (FT), tubular volume (VT), and tubular transit time (TT) were calculated on a per-patient basis. Results: The results show that triggered data have adequate temporal resolution to measure blood flow. The overall average values of the function parameters were: 152.77 (FP), 15.18 (VP), 6,73 (TP), 18.50 (FT), 35.36 (VT), and 117.67 (TT). The variability (calculated in % SD from the mean value) for three different respiratory triggering regions defined on a per-patient basis was between 0.81% and 9.87% for FP, 1.45% and 8.19% for VP, 0% and 9.63% for TP, 2.15% and 12.23% for TF, 0.8% and 17.28% for VT, and 1.97% and 12.87% for TT. Conclusion: Triggering reduces the oscillations in the signal curves and produces sharper parametric maps. In contrast to numerically challenging approaches like registration and segmentation it can be applied in clinical routine, but a (semi)-automatic approach to select the triggering ROI is desirable to reduce user dependence.

  11. Myocardial Perfusion SPECT 2015 in Germany

    Science.gov (United States)

    Burchert, Wolfgang; Schäfer, Wolfgang; Hacker, Marcus

    2016-01-01

    Summary Aim The working group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine presents the results of the 7th survey of myocardial perfusion SPECT (MPS) of the reporting year 2015. Method 268 questionnaires (173 practices [PR], 67 hospitals [HO], 28 university hospitals [UH]) were evaluated. Results of the last survey from 2012 are set in squared brackets. Results MPS of 121 939 [105 941] patients were reported. 98 % [95 %] of all MPS were performed with Tc-99m radiopharmaceuticals and 2 % [5 %] with Tl-201. 78 % [79 %] of all patients were studied in PR, 14 % [15 %] in HO, and 8 % [6 %] in UH. A pharmacological stress test was performed in 43 % [39 %] (22 % [24 %] adenosine, 20 % [9 %] regadenoson, 1% [6 %] dipyridamole or dobutamine). Attenuation correction was applied in 25 % [2009: 10 %] of MPS. Gated SPECT was performed in 78 % [70 %] of all rest MPS, in 80 % [73 %] of all stress and in 76 % [67 %] of all stress and rest MPS. 53 % [33 %] of all nuclear medicine departments performed MPS scoring by default, whereas 24 % [41 %] did not apply any quantification. 31 % [26 %] of all departments noticed an increase in their counted MPS and 29 % [29 %] no changes. Data from 89 departments which participated in all surveys showed an increase in MPS count of 11.1 % (PR: 12.2 %, HO: 4.8 %, UH: 18.4 %). 70 % [60 %] of the MPS were requested by ambulatory care cardiologists. Conclusion The 2015 MPS survey reveals a high-grade adherence of routine MPS practice to current guidelines. The positive trend in MPS performance and number of MPS already observed in 2012 continues. Educational training remains necessary in the field of SPECT scoring. PMID:27909712

  12. Transport of benzo[alpha]pyrene in the dually perfused human placenta perfusion model: effect of albumin in the perfusion medium

    DEFF Research Database (Denmark)

    Mathiesen, Line; Rytting, Erik; Mose, Tina

    2009-01-01

    compared to other species; since it is available without major ethical obstacles, we have used the human placenta perfusion model to study transport from mother to foetus. Placentas were donated after births at Rigshospitalet in Copenhagen from pregnant mothers who signed an informed consent. Ba...

  13. Placental and milk transfer, disposition and elimination of a single oral dose of [14C acetyl] acephate in Sprague Dawley rats

    International Nuclear Information System (INIS)

    Bakry, N.M.; Salama, A.K.; Abou-Donia, M.B.

    1991-01-01

    A single oral dose of 40 mg/kg (6.4 μCi/kg) of [ 14 C acetyl]acephate was administered on day 18 of gestation to pregnant Sprague Dawley rats. Eight groups of three rats were killed after 10 min and 0.5, 1, 3, 6, 12, 24, and 48 hr. At the end of the 48 hr experimental period, a total of 22.38% of the dose was exhaled as carbon dioxide, while only 1.25% and 0.60% of the dose were eliminated in the urine and feces, respectively. Trace amount (0.03% of the dose) was recovered in expired air as volatile materials. Radioactive acephate was rapidly absorbed and distributed in the tissues, with levels in most tissues reaching a peak concentration within 1 to 3 hr. The highest concentration of radioactivity was present in the maternal stomach followed by the liver. A total of 0.72% of the dose was recovered in the fetus. In another study, a single oral dose of 40 mg/kg [ 14 C acetyl]acephate was administered to the dams right after delivery. Nursing and suckling groups were killed at intervals of 1, 3, 6, 12, 24, 36, and 48 hr after dosing. Generally, the highest concentrations of radioactivity were present in the stomach, small intestine, liver, lung, and kidneys. A total of 0.96% of the dose was recovered in the sucklings

  14. Effect of trichloroethylene (TCE) toxicity on the enzymes of carbohydrate metabolism, brush border membrane and oxidative stress in kidney and other rat tissues.

    Science.gov (United States)

    Khan, Sheeba; Priyamvada, Shubha; Khan, Sara A; Khan, Wasim; Farooq, Neelam; Khan, Farah; Yusufi, A N K

    2009-07-01

    Trichloroethylene (TCE), an industrial solvent, is a major environmental contaminant. Histopathological examinations revealed that TCE caused liver and kidney toxicity and carcinogenicity. However, biochemical mechanism and tissue response to toxic insult are not completely elucidated. We hypothesized that TCE induces oxidative stress to various rat tissues and alters their metabolic functions. Male Wistar rats were given TCE (1000 mg/kg/day) in corn oil orally for 25 d. Blood and tissues were collected and analyzed for various biochemical and enzymatic parameters. TCE administration increased blood urea nitrogen, serum creatinine, cholesterol and alkaline phosphatase but decreased serum glucose, inorganic phosphate and phospholipids indicating kidney and liver toxicity. Activity of hexokinase, lactate dehydrogenase increased in the intestine and liver whereas decreased in renal tissues. Malate dehydrogenase and glucose-6-phosphatase and fructose-1, 6-bisphosphatase decreased in all tissues whereas increased in medulla. Glucose-6-phosphate dehydrogenase increased but NADP-malic enzyme decreased in all tissues except in medulla. The activity of BBM enzymes decreased but renal Na/Pi transport increased. Superoxide dismutase and catalase activities variably declined whereas lipid peroxidation significantly enhanced in all tissues. The present results indicate that TCE caused severe damage to kidney, intestine, liver and brain; altered carbohydrate metabolism and suppressed antioxidant defense system.

  15. 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

  16. Lung transplantation in the rat. III. Functional studies in iso- and allografts

    International Nuclear Information System (INIS)

    Marck, K.W.; Prop, J.; Wildevuur, C.R.

    1983-01-01

    Recently a microsurgical technique for orthotopic left lung transplantation in the rat was developed. The aim of this study was to investigate the influence of the operation itself and of an unmodified rejection reaction on the function of the transplanted rat lung. Orthotopic left lung transplantation was performed in 59 rats (34 isografts and 25 allografts). Isografts demonstrated a mean left lung perfusion of 23.1% in the first two postoperative weeks. Seven out of the 10 animals, subjected to a repeated scintigraphy 5-10 weeks later, had an increased graft perfusion, resulting in an almost normal mean left lung perfusion of 34.8%. At that time chest roentgenography revealed a good aeration of the grafts, that at autopsy had a normal aspect. Allografts showed an initial mean left lung perfusion (24.6%) similar to the isografts, which, however, declined sharply a few days later (4.3%). At that time chest roentgenography revealed totally opalescent grafts that at autopsy had the hepatized aspect characteristic of lung allograft rejection. These results of isogeneic and allogeneic lung transplantation in the rat were comparable with those of canine auto- and allotransplantation. For immunogenetic and economical reasons lung transplantation in the rat is a good alternative animal model in lung transplantation research

  17. Hot spots on Tc-99m MAA perfusion lung scan

    International Nuclear Information System (INIS)

    Lim, Seok Tae; Sohn, Myung Hee

    2001-01-01

    A 61 year-old woman underwent perfusion and inhalation lung scan for the evaluation of pulmonary thromboembolism. Tc-99m MAA perfusion lung scan showed multiple round hot spots in both lung fields. Tc-99m DTPA aerosol inhalation lung scan and chest radiography taken at the same time showed normal findings. A repeated perfusion lung scan taken 24 hours later demonstrated no abnormalities. Hot spots on perfusion lung scan can be caused by microsphere clumping due to faulty injection technique by radioactive embolization from upper extremity thrombophlebitis after injection. Focal hot spots can signify zones of atelectasis, where the hot spots probably represent a failure of hypoxic vasoconstriction. Artifactual hot spots due to microsphere clumping usually appear to be round and in peripheral location, and the lesions due to a loss of hypoxic vasoconstriction usually appear to be hot uptakes having linear borders. Although these artifactual hot spots have been well-known, we rarely encounter them. This report presents a case with artifactual hot spots due to microsphere clumping on Tc-99m MAA perfusion lung scan

  18. Hyperperfusion on Perfusion Computed Tomography Following Revascularization for Acute Stroke

    International Nuclear Information System (INIS)

    Nguyen, T.B.; Lum, C.; Eastwood, J.D.; Stys, P.K.; Hogan, M.; Goyal, M.

    2005-01-01

    Purpose: To describe the findings of hyperperfusion on perfusion computed tomography (CT) in four patients following revascularization for acute stroke. Material and Methods: In 2002-2003, among a series of 6 patients presenting with an acute stroke and treated with intra-arterial thrombolysis, we observed the presence of hyperperfusion in 3 patients on the follow-up CT perfusion. We included an additional patient who was treated with intravenous thrombolysis and who had hyperperfusion on the follow-up CT perfusion. We retrospectively analyzed their CT perfusion maps. Cerebral blood volume (CBV) and cerebral blood flow (CBF) maps were compared between the affected territory and the normal contralateral hemisphere. Results: In the four patients, the mean CBV and CBF were 3.6±2.0 ml/100 g and 39±25 ml/100 g/min in the affected territory compared to the normal side (mean CBV 2.7±2.1 ml/100 g, mean CBF = 27±23 ml/100 g/min). There was no intracranial hemorrhage in the hyperperfused territories. At follow-up CT, some hyperperfused brain areas progressed to infarction, while others retained normal white to gray matter differentiation. Conclusion: CT perfusion can demonstrate hyperperfusion, which can be seen in an ischemic brain territory following recanalization

  19. Clinical evaluation of non-invasive perfusion-weighted MRI

    International Nuclear Information System (INIS)

    Takasu, Miyuki

    2000-01-01

    A spin labeling method to measure cerebral blood flow without a contrast medium was developed and applied clinically to obtain a non-invasive perfusion-weighted image. The purpose of this study is to compare the non-invasive perfusion-weighted image using FAIR with the well-established PWI using a bolus injection of Gd-DTPA. Of 41 lesions which revealed decreased perfusion, 13 were shown to be low signal intensity areas on FAIR. Therefore, detection rate of FAIR for hypoperfusion was 32%. Of 8 lesions which revealed increased perfusion, 7 demonstrated high intensity on FAIR. Therefore, detection rate of FAIR for hyperperfusion was 88%. Seven lesions were found to have a mean pixel value of zero on PWI. Of these lesions, 5 lesions could be detected as high signal intensity area on FAIR. The rCBV- and rCBF index ratios of hypoperfused lesions detected on FAIR were significantly lower than those of lesions which were not detected on FAIR (p=0.007, p=0.01). As concerns the lesions detected of FAIR, there were positive correlation between rCBV- or rCBF index ratio and FAIR signal ratio (rCBV ratio: ρ=0.873, p=0.0002, rCBF index ratio: ρ=0.858, p=0.0003). FAIR is valuable clinical tool to detect perfusion abnormality semi-quantitatively without contrast medium, although it showed relatively low detection rate for hypoperfused lesions. (author)

  20. CT Perfusion evaluation of gastric cancer. Correlation with histologic type

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Ho; Joo, Ijin [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Kim, Se Hyung [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Han, Joon Koo [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of)

    2018-02-15

    To prospectively evaluate if the perfusion parameters of gastric cancer can provide information on histologic subtypes of gastric cancer. We performed preoperative perfusion CT (PCT) and curative gastrectomy in 46 patients. PCT data were analysed using a dedicated software program. Perfusion parameters were obtained by two independent radiologists and were compared according to histologic type using Kruskal-Wallis, Mann-Whitney U test and receiver operating characteristic analysis. To assess inter-reader agreement, we used intraclass correlation coefficient (ICC). Inter-reader agreement for perfusion parameters was moderate to substantial (ICC = 0.585-0.678). Permeability surface value of poorly cohesive carcinoma (PCC) was significantly higher than other histologic types (47.3 ml/100 g/min in PCC vs 26.5 ml/100 g/min in non-PCC, P < 0.001). Mean transit time (MTT) of PCC was also significantly longer than non-PCC (13.0 s in PCC vs 10.3 s in non-PCC, P = 0.032). The area under the curve to predict PCC was 0.891 (P < 0.001) for permeability surface and 0.697 (P = 0.015) for MTT. Obtaining perfusion parameters from PCT was feasible in gastric cancer patients and can aid in the preoperative imaging diagnosis of PCC-type gastric cancer as the permeability surface and MTT value of PCC type gastric cancer were significantly higher than those of non-PCC. (orig.)

  1. Perfusion imaging with single-photon emission computed tomography

    International Nuclear Information System (INIS)

    Holman, B.L.; Hill, T.C.

    1987-01-01

    SPECT with perfusion tracers is useful in a number of circumstances: (1) In acute cerebral infarction while the CT scan may be normal for several days after onset of symptoms, the uptake of SPECT perfusion tracers will be altered immediately after the onset of the stroke. Even when the CT scan has become abnormal, the physiologic abnormality may exceed the anatomic abnormality. One may, therefore be able to measure the extent of the reversibly ischemic tissue early enough to justify more agressive therapeutic interventions. (2) For endarterectomy and other surgical and medical therapies serial measurements of regional cerebral perfusion with SPECT may provide a readily available tool to assess their efficacy. (3) SPECT perfusion imaging may become the method of choice for the diagnosis and evaluation of Alzheimer's disease. (4) In patients with epilepsy, the extent and location of the abnormally perfused focus may be important to medical and surgical management. Follow-up examination may be useful in documenting the effectiveness of therapy

  2. CT Perfusion evaluation of gastric cancer. Correlation with histologic type

    International Nuclear Information System (INIS)

    Lee, Dong Ho; Joo, Ijin; Kim, Se Hyung; Han, Joon Koo

    2018-01-01

    To prospectively evaluate if the perfusion parameters of gastric cancer can provide information on histologic subtypes of gastric cancer. We performed preoperative perfusion CT (PCT) and curative gastrectomy in 46 patients. PCT data were analysed using a dedicated software program. Perfusion parameters were obtained by two independent radiologists and were compared according to histologic type using Kruskal-Wallis, Mann-Whitney U test and receiver operating characteristic analysis. To assess inter-reader agreement, we used intraclass correlation coefficient (ICC). Inter-reader agreement for perfusion parameters was moderate to substantial (ICC = 0.585-0.678). Permeability surface value of poorly cohesive carcinoma (PCC) was significantly higher than other histologic types (47.3 ml/100 g/min in PCC vs 26.5 ml/100 g/min in non-PCC, P < 0.001). Mean transit time (MTT) of PCC was also significantly longer than non-PCC (13.0 s in PCC vs 10.3 s in non-PCC, P = 0.032). The area under the curve to predict PCC was 0.891 (P < 0.001) for permeability surface and 0.697 (P = 0.015) for MTT. Obtaining perfusion parameters from PCT was feasible in gastric cancer patients and can aid in the preoperative imaging diagnosis of PCC-type gastric cancer as the permeability surface and MTT value of PCC type gastric cancer were significantly higher than those of non-PCC. (orig.)

  3. Magnetic resonance cardiac perfusion imaging-a clinical perspective

    Energy Technology Data Exchange (ETDEWEB)

    Hunold, Peter; Schlosser, Thomas; Barkhausen, Joerg [University Hospital, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany)

    2006-08-15

    Coronary artery disease (CAD) with its clinical appearance of stable or unstable angina and acute myocardial infarction is the leading cause of death in developed countries. In view of increasing costs and the rising number of CAD patients, there has been a major interest in reliable non-invasive imaging techniques to identify CAD in an early (i.e. asymptomatic) stage. Since myocardial perfusion deficits appear very early in the ''ischemic cascade'', a major breakthrough would be the non-invasive quantification of myocardial perfusion before functional impairment might be detected. Therefore, there is growing interest in other, target-organ-specific parameters, such as relative and absolute myocardial perfusion imaging. Magnetic resonance (MR) imaging has been proven to offer attractive concepts in this respect. However, some important difficulties have not been resolved so far, which still causes uncertainty and prevents the broad application of MR perfusion imaging in a clinical setting. This review explores recent technical developments in MR hardware, software and contrast agents, as well as their impact on the current and future clinical status of MR imaging of first-pass myocardial perfusion imaging. (orig.)

  4. Magnetic resonance cardiac perfusion imaging-a clinical perspective

    International Nuclear Information System (INIS)

    Hunold, Peter; Schlosser, Thomas; Barkhausen, Joerg

    2006-01-01

    Coronary artery disease (CAD) with its clinical appearance of stable or unstable angina and acute myocardial infarction is the leading cause of death in developed countries. In view of increasing costs and the rising number of CAD patients, there has been a major interest in reliable non-invasive imaging techniques to identify CAD in an early (i.e. asymptomatic) stage. Since myocardial perfusion deficits appear very early in the ''ischemic cascade'', a major breakthrough would be the non-invasive quantification of myocardial perfusion before functional impairment might be detected. Therefore, there is growing interest in other, target-organ-specific parameters, such as relative and absolute myocardial perfusion imaging. Magnetic resonance (MR) imaging has been proven to offer attractive concepts in this respect. However, some important difficulties have not been resolved so far, which still causes uncertainty and prevents the broad application of MR perfusion imaging in a clinical setting. This review explores recent technical developments in MR hardware, software and contrast agents, as well as their impact on the current and future clinical status of MR imaging of first-pass myocardial perfusion imaging. (orig.)

  5. Ventilation perfusion radionuclide imaging in cryptogenic fibrosing alveolitis

    International Nuclear Information System (INIS)

    Bourke, S.J.; Hawkins, T.; Keavey, P.M.; Gascoigne, A.D.; Corris, P.A.

    1993-01-01

    There is increasing interest in ventilation perfusion (V/Q) imaging in cryptogenic fibrosing alveolitis because of the data these scans provide on the dynamic V/Q relationships in such patients undergoing single lung transplantation. We analysed the V/Q scans of 45 consecutive patients with advanced cryptogenic fibrosing alveolitis being considered for single lung transplantation. Scans were classified according to the presence, severity and degree of matching of defects in ventilation and perfusion images and the results were compared with the data obtained from lung function tests. Ventilation images showed defects in 13 (29%) and ''washout delay'' in 15 (33%) patients; 10 (22%) patients had asymmetric distribution of ventilation with one lung receiving >60% of total ventilation. Perfusion images showed normal perfusion in 8 (18%), mild defects in 18 (40%) and major defects in 19 (42%) patients. The distribution of perfusion between lungs was significantly asymmetric in 20 (45%) patients. V/Q images were matched in 15 (33%), mildly mismatched in 15 (33%) and severely mismatched in 15 (33%) patients, but the degree of V/Q mismatch did not show a relationship to KCO, PaO 2 or A-aO 2 gradient. The appearances were atypical of pulmonary embolism in eight patients. (Author)

  6. Plasma-mediated vascular dysfunction in the reduced uterine perfusion pressure model of preeclampsia: a microvascular characterization.

    LENUS (Irish Health Repository)

    Walsh, Sarah K

    2012-01-31

    Preeclampsia is associated with widespread maternal vascular dysfunction, which is thought to be mediated by circulating factor(s). The aim of the study was to characterize vascular function in the reduced uterine perfusion pressure (RUPP) rat model of preeclampsia and to investigate the role of plasma factors in mediating any observed changes in vascular reactivity. Mean arterial blood pressure and vascular function were measured in RUPP and control rats. Mesenteric vessels from both virgin and pregnant rats were exposed for 1 hour or overnight to plasma from both RUPP and control rats and their vascular function assessed. RUPP rats were characterized by severe hypertension, restricted fetal growth, and reduced placental weight (P<0.001). Vasorelaxation was impaired in resistance vessels from RUPP compared with control rats (acetylcholine: R(max) 70+\\/-3 versus 92+\\/-1 [NP] and 93+\\/-3% [sham], P<0.01; bradykinin: 40+\\/-2 versus 62+\\/-2 [NP] and 59+\\/-4% [sham], P<0.001). Incubation of vessels from pregnant (but not virgin) animals with RUPP plasma overnight resulted in an attenuation of vasorelaxant responses (acetylcholine: 63+\\/-7 versus 86+\\/-2%, P<0.05; bradykinin: 35+\\/-5 versus 55+\\/-6%, P<0.001). The residual relaxant response in RUPP plasma-treated vessels was not further attenuated after treatment with N(omega)-nitro-l-arginine methyl ester (acetylcholine: 57+\\/-7 versus 63+\\/-7%, ns; bradykinin: 37+\\/-5 versus 35+\\/-5%, ns). The RUPP rat model is characterized by an impaired response to vasodilators which may be attributable to one or more circulating factors. This plasma-mediated endothelial dysfunction appears to be a pregnancy-dependent effect. Furthermore, nitric oxide-mediated vasorelaxation appears to be absent in RUPP plasma-treated vessels.

  7. Dynamic spatio-temporal imaging of early reflow in a neonatal rat stroke model.

    Science.gov (United States)

    Leger, Pierre-Louis; Bonnin, Philippe; Lacombe, Pierre; Couture-Lepetit, Elisabeth; Fau, Sebastien; Renolleau, Sylvain; Gharib, Abdallah; Baud, Olivier; Charriaut-Marlangue, Christiane

    2013-01-01

    The aim of the study was to better understand blood-flow changes in large arteries and microvessels during the first 15 minutes of reflow in a P7 rat model of arterial occlusion. Blood-flow changes were monitored by using ultrasound imaging with sequential Doppler recordings in internal carotid arteries (ICAs) and basilar trunk. Relative cerebral blood flow (rCBF) changes were obtained by using laser speckle Doppler monitoring. Tissue perfusion was measured with [(14)C]-iodoantipyrine autoradiography. Cerebral energy metabolism was evaluated by mitochondrial oxygen consumption. Gradual increase in mean blood-flow velocities illustrated a gradual perfusion during early reflow in both ICAs. On ischemia, the middle cerebral artery (MCA) territory presented a residual perfusion, whereas the caudal territory remained normally perfused. On reflow, speckle images showed a caudorostral propagation of reperfusion through anastomotic connections, and a reduced perfusion in the MCA territory. Autoradiography highlighted the caudorostral gradient, and persistent perfusion in ventral and medial regions. These blood-flow changes were accompanied by mitochondrial respiration impairment in the ipsilateral cortex. Collectively, these data indicate the presence of a primary collateral pathway through the circle of Willis, providing an immediate diversion of blood flow toward ischemic regions, and secondary efficient cortical anastomoses in the immature rat brain.

  8. Bacterial lipopolysaccharide-induced systemic inflammation alters perfusion of white matter-rich regions without altering flow in brain-irrigating arteries: Relationship to blood-brain barrier breakdown?

    Science.gov (United States)

    Dhaya, Ibtihel; Griton, Marion; Raffard, Gérard; Amri, Mohamed; Hiba, Bassem; Konsman, Jan Pieter

    2018-01-15

    To better understand brain dysfunction during sepsis, cerebral arterial blood flow was assessed with Phase Contrast Magnetic Resonance Imaging, perfusion with Arterial Spin Labeling and structure with diffusion-weighted Magnetic Resonance Imaging in rats after intraperitoneal administration of bacterial lipopolysaccharides. Although cerebral arterial flow was not altered, perfusion of the corpus callosum region and diffusion parallel to its fibers were higher after lipopolysaccharide administration as compared to saline injection. In parallel, lipopolysaccharide induced perivascular immunoglobulin-immunoreactivity in white matter. These findings indicate that systemic inflammation can result in increased perfusion, blood-brain barrier breakdown and altered water diffusion in white matter. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Technetium-99m p-iodophenethyldiaminodithiol (DADT-IPE): potential brain perfusion imaging agent for SPECT

    International Nuclear Information System (INIS)

    Shiba, K.; Mori, H.; Matsuda, H.; Hisada, K.

    1992-01-01

    A new ligand, an N-p-iodophenethyl diaminodithiol (DADT-IPE), an analog of N-isopropyl-p-iodoamphetamine (IMP), was synthesized and subsequently complexed with 99m Tc, using stannous chloride as a reducing agent. Two complexes (a and b) were separated from 99m Tc-DADT-IPE by high performance liquid chromatography (HPLC). Competitive inhibition studies showed that the IC 50 value of DADT-IPE (70 μM) was similar to that of IMP (49 μM). Biodistribution studies of one of the complexes [ 99m Tc-DADT-IPE(a)] in rats showed that 0.65% of the injected dose of the tracer remained in the brain at 5 min after intravenous injection, with 0.53% of the dose remaining in the brain at 60 min post-injection, whereas the corresponding values for the other complex [ 99m Tc-DADT-IPE(b)] were 0.34% dose in the brain at 5 min and 0.28% dose in the brain at 60 min post-injection. The half-life for clearance of 99m Tc-DADT-IPE(a) from rat brain was found to be more than 5h. These results suggested that 99m Tc-DADT-IPE(a) has characteristics which are suitable for cerebral perfusion imaging. (author)

  10. In vivo MR perfusion imaging of renal artery stenosis

    International Nuclear Information System (INIS)

    Powers, T.; Lorenz, C.H.; Bain, R.; Holburn, G.; Price, R.R.

    1989-01-01

    Various techniques have been developed for noninvasive evaluation of renal blood flow. More important in the assessment of potential renal ischemia may be actual perfusion of the nephron mass. MR pulse sequences have been devised that allow perfusion imaging (PI) in a dog model of renal artery stenosis. Unilateral renal artery stenosis was created in mongrel dogs and quantitation of renal blood flow was obtained with radioactive microspheres. Perfusion imaging was performed on a 1.5-T system to obtain the apparent diffusion coefficient. During initial studies, it was found that the usual gradient factor used in brain PI was too high for renal studies; a factor of < 50 was found to be optimal. Additionally, respiratory gating with acquisition at end expiration was necessary to prevent renal motion. Recent studies have shown that PI reflects the asymmetry of flow in this model

  11. Improved perfusion quantification in FAIR imaging by offset correction

    DEFF Research Database (Denmark)

    Sidaros, Karam; Andersen, Irene Klærke; Gesmar, Henrik

    2001-01-01

    Perfusion quantification using pulsed arterial spin labeling has been shown to be sensitive to the RF pulse slice profiles. Therefore, in Flow-sensitive Alternating-Inversion Recovery (FAIR) imaging the slice selective (ss) inversion slab is usually three to four times thicker than the imaging...... slice. However, this reduces perfusion sensitivity due to the increased transit delay of the incoming blood with unperturbed spins. In the present article, the dependence of the magnetization on the RF pulse slice profiles is inspected both theoretically and experimentally. A perfusion quantification...... model is presented that allows the use of thinner ss inversion slabs by taking into account the offset of RF slice profiles between ss and nonselective inversion slabs. This model was tested in both phantom and human studies. Magn Reson Med 46:193-197, 2001...

  12. Testosterone biotransformation by the isolated perfused canine pancreas

    International Nuclear Information System (INIS)

    Fernandez-del Castillo, C.; Diaz-Sanchez, V.; Varela-Fascinetto, G.; Altamirano, A.; Odor-Morales, A.; Lopez-Medrano, R.M.; Robles-Diaz, G.

    1991-01-01

    There is strong evidence indicating that the pancreas is under the influence of sex steroid hormones, and that it may even participate in their biosynthesis and metabolism. In the present study, [3H]testosterone was perfused into the isolated canine pancreas, and measured in the effluent with several of its metabolites (5 alpha-dihydrotestosterone, androstenedione, and estradiol). Results show that testosterone is readily transformed by the canine pancreas. The main product found in the effluent is androstenedione. The testis and spleen were also perfused with [3H]testosterone and used as controls. In both cases, this hormone appeared mostly unchanged in the effluent as compared to the pancreatic perfusion (p less than 0.0001). From our data, we conclude that the canine pancreas has the capacity to transform sex steroid hormones, and could be considered an extragonadal site of sex steroid biosynthesis

  13. CT perfusion imaging in the management of posterior reversible encephalopathy

    International Nuclear Information System (INIS)

    Casey, S.O.; McKinney, A.; Teksam, M.; Liu, H.; Truwit, C.L.

    2004-01-01

    A 13-year-old girl with a renal transplant presented with hypertension and seizures. CT and MRI demonstrated typical bilateral parietal, occipital and posterior frontal cortical and subcortical edema, thought to represent posterior reversible encephalopathy syndrome. The cause was presumed to be hypertension. Antihypertensive therapy was started, lowering of the blood pressure in the range of 110-120 mmHg systolic. However, stable xenon (Xe) CT perfusion imaging revealed ischemia within the left parietal occipital region. The antihypertensive was adjusted which increased both the systolic and diastolic blood pressure by 31 mm Hg. The patient was re-imaged with Xe CT and was found to have resolution of the ischemic changes within the left parietal occipital region. In this report, we present a case in which stable Xe CT was used to monitor the degree of cerebral perfusion and guide titration of antihypertensive therapy. Such brain perfusion monitoring may have helped to prevent infarction of our patient. (orig.)

  14. Intestinal perfusion in the study of intestinal absorption

    International Nuclear Information System (INIS)

    Baker, S.J.

    1976-01-01

    Several techniques for studying absorption by means of intestinal perfusion have been developed. While the principle is simple, the practice is complicated by absorption of the solvent and by excretion of fluid into the lumen. To improve reliability a ''marker'' is incorporated into the system; it should behave as nearly as possible like the nutrient of interest, except that it should be unabsorbable. A great many markers, including several labelled with radionuclides, have been developed for use with numerous nutrients, and perfusion methods using double or triple tubes or occlusive balloons have been tested. The perfusion technique is too complicated for routine diagnostic use, but it offers at present the only possibility of studying the function of defined sections of the small intestine in the intact human. (author)

  15. CT of malignant choroidal melanoma - morphology and perfusion characteristics

    International Nuclear Information System (INIS)

    Heller, M.; Hagemann, J.; Jend, H.H.; Guthoff, R.

    1982-01-01

    The computed tomographic morphology of malignant choroidal melanoma and its perfusion characteristics are described. Thirty-three static and serial CT examinations made on 29 patients with choroidal melanoma, three with pseudotumors of the macula and one with choroidal metastasis revealed the choroidal melanoma to be usually a hyperdense, markedly perfused tumor, while the non-contrast, diagnostically undifferentiable pseudotumors and the choroidal metastasis, revealed no significant change in density after the administration of contrast material. Density values or perfusion characteristics of choroidal melanoma that are outside of the normal range are a result of secondary changes within the immediate surroundings of the tumor, such as detachment of the retina, tumor-induced glaucoma, or tumor necrosis. (orig.)

  16. Assessment of femoral head perfusion by dynamic MR imaging

    International Nuclear Information System (INIS)

    Ochi, Ryuya; Nakano, Tetsuo; Miyazono, Kazuki; Tsurugami, Hiroshi; Fukuda, Tomohiro; Inaba, Daisuke; Takada, Koji

    2004-01-01

    We studied femoral head perfusion in 21 femoral neck fractures using dynamic MR imaging (MRI) between November 2001 and July 2002. MRI patterns divided into four groups when the results between the fractured side and unaffected side were compared. Femoral head perfusion at the fractured side was normal in Type A, about half in Type B, and absent in Type C. When perfusion at both the fractured side and unaffected side was absent, Exceptional Type was suspected. The Garden I group consisted of one Type B. The Garden II group consisted of one Type A, six Type B, one Type C, and two Exceptional Type. The Garden III group consisted of two Type B and one Type C, and the Garden IV group consisted of six Type C and one Exceptional Type. Post operations of by internal fixation confirmed the incidence of aseptic necrosis using MRI. (author)

  17. Testosterone biotransformation by the isolated perfused canine pancreas

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-del Castillo, C.; Diaz-Sanchez, V.; Varela-Fascinetto, G.; Altamirano, A.; Odor-Morales, A.; Lopez-Medrano, R.M.; Robles-Diaz, G. (Instituto Nacional de la Nutricion Salvador Zubiran, Mexico City (Mexico))

    1991-01-01

    There is strong evidence indicating that the pancreas is under the influence of sex steroid hormones, and that it may even participate in their biosynthesis and metabolism. In the present study, (3H)testosterone was perfused into the isolated canine pancreas, and measured in the effluent with several of its metabolites (5 alpha-dihydrotestosterone, androstenedione, and estradiol). Results show that testosterone is readily transformed by the canine pancreas. The main product found in the effluent is androstenedione. The testis and spleen were also perfused with (3H)testosterone and used as controls. In both cases, this hormone appeared mostly unchanged in the effluent as compared to the pancreatic perfusion (p less than 0.0001). From our data, we conclude that the canine pancreas has the capacity to transform sex steroid hormones, and could be considered an extragonadal site of sex steroid biosynthesis.

  18. Prognostic Value of Normal Perfusion but Impaired Left Ventricular Function in the Diabetic Heart on Quantitative Gated Myocardial Perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hwanjeong; Choi, Sehun; Han, Yeonhee [Research Institute of Chonbuk National Univ. Medical School and Hospitial, Jeonju (Korea, Republic of); Lee, Dong Soo; Lee, Hoyoung; Chung, Junekey [Seoul National Univ., Seoul (Korea, Republic of)

    2013-09-15

    This study aimed at identifying the predictive parameters on quantitative gated myocardial perfusion single-photon emission computed tomography (QG-SPECT) in diabetic patients with normal perfusion but impaired function. Methods Among the 533 consecutive diabetic patients, 379 patients with normal perfusion on rest Tl-201/dipyridamole-stress Tc-{sup 99m} sestamibi Gated SPECT were enrolled. Patients were grouped into those with normal post-stress left ventricular function (Group I) and those with impaired function (EF <50 or impaired regional wall motion, Group II). We investigated cardiac events and cause of death by chart review and telephone interview. Survival analysis and Cox proportional hazard model analysis were performed. Between the Group I and II, cardiac events as well as chest pain symptoms, smoking, diabetic complications were significantly different (P<0.05). On survival analysis, event free survival rate in Group II was significantly lower than in Group I (P=0.016). In univariate Cox proportional hazard analysis on overall cardiac event, Group (II over I), diabetic nephropathy, summed motion score (SMS), summed systolic thickening score (STS), numbers of abnormal segmental wall motion and systolic thickening predicted more cardiac events (P<0.05). Multivariate analysis showed that STS was the only independent predictor cardiac event. The functional parameter, especially summed systolic thickening score on QG-SPECT had prognostic values, despite normal perfusion, in predicting cardiac events in diabetic patients, and QG-SPECT provides clinically useful risk stratification in diabetic patients with normal perfusion.

  19. Potency of maternal folic acid supplementation on gamma irradiation- induced histological and embryological anomalies in albino rats

    International Nuclear Information System (INIS)

    Rezk, R.G.; Ibrahim, M.F.

    2006-01-01

    Folic acid, a member of the water-soluble vitamin B group, is emerged as an important nutritional factor especially during the course of pregnancy. It is rapidly absorbed from the proximal part of small intestine, distributed to the body tissues, stored in the liver and actively concentrated in the cerebrospinal fluid. The objective of this study was to evaluate the potency of maternal folic acid supplementation in ameliorating the maternal and fetal detrimental impacts of gamma irradiation. Folic acid, at a dose level of 4 mg/Kg body weight was daily administered via an oral stomach tube to pregnant adult albino rats from the 1st to the 20 th day of pregnancy, while mothers were subjected to gamma irradiation at the dose of 3 Gy on day 10 of gestation during the sensitive period of organogenesis. Experimental investigations carried out 1 day prior to parturition have demonstrated that folic acid intake throughout the whole gestational period had significantly diminished the deleterious histopathological disorders in large intestine, liver and uterus of irradiated mothers. Concomitantly, folic acid has been able to enfeeble the hazardous teratological effects of radiation including mainly the fetal intrauterine lethality, developmental delay and prominent morphological deformities. Conclusively, folic acid was found to offer protection during pregnancy against radiation injury, thus was capable of modulating the histopathological impacts of the studied maternal body organs and suppressing the embryonic mortality rates and serious fetal malformations induced by radiation

  20. Unexpected Lack of Deleterious Effects of Uranium on Physiological Systems following a Chronic Oral Intake in Adult Rat

    Directory of Open Access Journals (Sweden)

    Isabelle Dublineau

    2014-01-01

    Full Text Available Uranium level in drinking water is usually in the range of microgram-per-liter, but this value may be as much as 100 to 1000 times higher in some areas, which may raise question about the health consequences for human populations living in these areas. Our purpose was to improve knowledge of chemical effects of uranium following chronic ingestion. Experiments were performed on rats contaminated for 9 months via drinking water containing depleted uranium (0.2, 2, 5, 10, 20, 40, or 120 mg/L. Blood biochemical and hematological indicators were measured and several different types of investigations (molecular, functional, and structural were conducted in organs (intestine, liver, kidneys, hematopoietic cells, and brain. The specific sensitivity of the organs to uranium was deduced from nondeleterious biological effects, with the following thresholds (in mg/L: 0.2 for brain, >2 for liver, >10 for kidneys, and >20 for intestine, indicating a NOAEL (No-Observed-Adverse-Effect Level threshold for uranium superior to 120 m g/L. Based on the chemical uranium toxicity, the tolerable daily intake calculation yields a guideline value for humans of 1350 μg/L. This value was higher than the WHO value of 30 μg/L, indicating that this WHO guideline for uranium content in drinking water is very protective and might be reconsidered.

  1. Unexpected lack of deleterious effects of uranium on physiological systems following a chronic oral intake in adult rat.

    Science.gov (United States)

    Dublineau, Isabelle; Souidi, Maâmar; Gueguen, Yann; Lestaevel, Philippe; Bertho, Jean-Marc; Manens, Line; Delissen, Olivia; Grison, Stéphane; Paulard, Anaïs; Monin, Audrey; Kern, Yseult; Rouas, Caroline; Loyen, Jeanne; Gourmelon, Patrick; Aigueperse, Jocelyne

    2014-01-01

    Uranium level in drinking water is usually in the range of microgram-per-liter, but this value may be as much as 100 to 1000 times higher in some areas, which may raise question about the health consequences for human populations living in these areas. Our purpose was to improve knowledge of chemical effects of uranium following chronic ingestion. Experiments were performed on rats contaminated for 9 months via drinking water containing depleted uranium (0.2, 2, 5, 10, 20, 40, or 120 mg/L). Blood biochemical and hematological indicators were measured and several different types of investigations (molecular, functional, and structural) were conducted in organs (intestine, liver, kidneys, hematopoietic cells, and brain). The specific sensitivity of the organs to uranium was deduced from nondeleterious biological effects, with the following thresholds (in mg/L): 0.2 for brain, >2 for liver, >10 for kidneys, and >20 for intestine, indicating a NOAEL (No-Observed-Adverse-Effect Level) threshold for uranium superior to 120 m g/L. Based on the chemical uranium toxicity, the tolerable daily intake calculation yields a guideline value for humans of 1350 μg/L. This value was higher than the WHO value of 30 μg/L, indicating that this WHO guideline for uranium content in drinking water is very protective and might be reconsidered.

  2. Potency of maternal folic acid supplementation on gamma irradiation- induced histological and embryological anomalies in albino rats

    Energy Technology Data Exchange (ETDEWEB)

    Rezk, R G [Health Rad. Res., NCRRT, Cairo (Egypt); Ibrahim, M F [Rad. Biology Dept., NCRRT, Cairo (Egypt)

    2006-07-01

    Folic acid, a member of the water-soluble vitamin B group, is emerged as an important nutritional factor especially during the course of pregnancy. It is rapidly absorbed from the proximal part of small intestine, distributed to the body tissues, stored in the liver and actively concentrated in the cerebrospinal fluid. The objective of this study was to evaluate the potency of maternal folic acid supplementation in ameliorating the maternal and fetal detrimental impacts of gamma irradiation. Folic acid, at a dose level of 4 mg/Kg body weight was daily administered via an oral stomach tube to pregnant adult albino rats from the 1st to the 20 th day of pregnancy, while mothers were subjected to gamma irradiation at the dose of 3 Gy on day 10 of gestation during the sensitive period of organogenesis. Experimental investigations carried out 1 day prior to parturition have demonstrated that folic acid intake throughout the whole gestational period had significantly diminished the deleterious histopathological disorders in large intestine, liver and uterus of irradiated mothers. Concomitantly, folic acid has been able to enfeeble the hazardous teratological effects of radiation including mainly the fetal intrauterine lethality, developmental delay and prominent morphological deformities. Conclusively, folic acid was found to offer protection during pregnancy against radiation injury, thus was capable of modulating the histopathological impacts of the studied maternal body organs and suppressing the embryonic mortality rates and serious fetal malformations induced by radiation.

  3. 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

  4. Characterizing potential heart agents with an isolated perfused heart system

    International Nuclear Information System (INIS)

    Pendleton, D.B.; Sands, H.; Gallagher, B.M.; Camin, L.L.

    1984-01-01

    The authors have used an isolated perfused heart system for characterizing potential myocardial perfusion radiopharamaceuticals. Rabbit or guinea pig (GP) hearts are removed and perfused through the aorta with a blood-free buffer. Heart rate and ventricular pressure are monitored as indices of viability. Tc-99m-MAA is 96-100% retained in these hearts, and Tc-99m human serum albumin shows less than 5% extraction. Tl-201 is 30-40% extracted. It is known that in-vivo, Tc-99m(dmpe)/sub 2/Cl/sub 2//sup +/ is taken up by rabbit heart but not by GP or human heart. Analogous results are obtained with the isolated perfused heart model, where the complex is extracted well by the isolated rabbit heart (24%) but not by the GP heart (<5%). Values are unchanged if human, rabbit or GP blood is mixed and co-injected with the complex. Tc-99m)dmpe)/sub 3//sup +/ is also taken up by rabbit but not by GP hearts in-vivo. However, isolated perfused hearts of both species extract this complex well (45-52%). Heart uptake is diminished to <7% if the complex is pre-equilibrated with human blood. GP blood produces a moderate inhibition (in GP hearts only) and rabbit blood has no effect. This suggests that a human or GP blood factor may have a significant effect on heart uptake of this complex. Tc-99m(CN-t-butyl)/sub 6//sup +/ is taken up well by both rabbit and GP hearts in-vivo, and is extracted 100% by both isolated perfused hearts. Heart retention remains high (73-75%) in the presence of human blood

  5. Skin Blood Perfusion and Oxygenation Colour Affect Perceived Human Health

    Science.gov (United States)

    Stephen, Ian D.; Coetzee, Vinet; Law Smith, Miriam; Perrett, David I.

    2009-01-01

    Skin blood perfusion and oxygenation depends upon cardiovascular, hormonal and circulatory health in humans and provides socio-sexual signals of underlying physiology, dominance and reproductive status in some primates. We allowed participants to manipulate colour calibrated facial photographs along empirically-measured oxygenated and deoxygenated blood colour axes both separately and simultaneously, to optimise healthy appearance. Participants increased skin blood colour, particularly oxygenated, above basal levels to optimise healthy appearance. We show, therefore, that skin blood perfusion and oxygenation influence perceived health in a way that may be important to mate choice. PMID:19337378

  6. 'Motion frozen' quantification and display of myocardial perfusion gated SPECT

    International Nuclear Information System (INIS)

    Slomka, P.J.; Hurwitz, G.A.; Baddredine, M.; Baranowski, J.; Aladl, U.E.

    2002-01-01

    Aim: Gated SPECT imaging incorporates both functional and perfusion information of the left ventricle (LV). However perfusion data is confounded by the effect of ventricular motion. Most existing quantification paradigms simply add all gated frames and then proceed to extract the perfusion information from static images, discarding the effects of cardiac motion. In an attempt to improve the reliability and accuracy of cardiac SPECT quantification we propose to eliminate the LV motion prior to the perfusion quantification via automated image warping algorithm. Methods: A pilot series of 14 male and 11 female gated stress SPECT images acquired with 8 time bins have been co-registered to the coordinates of the 3D normal templates. Subsequently the LV endo and epi-cardial 3D points (300-500) were identified on end-systolic (ES) and end-diastolic (ED) frames, defining the ES-ED motion vectors. The nonlinear image warping algorithm (thin-plate-spline) was then applied to warp end-systolic frame was onto the end-diastolic frames using the corresponding ES-ED motion vectors. The remaining 6 intermediate frames were also transformed to the ED coordinates using fractions of the motion vectors. Such warped images were then summed to provide the LV perfusion image in the ED phase but with counts from the full cycle. Results: The identification of the ED/ES corresponding points was successful in all cases. The corrected displacement between ED and ES images was up to 25 mm. The summed images had the appearance of the ED frames but have been much less noisy since all the counts have been used. The spatial resolution of such images appeared higher than that of summed gated images, especially in the female scans. These 'motion frozen' images could be displayed and quantified as regular non-gated tomograms including polar map paradigm. Conclusions: This image processing technique may improve the effective image resolution of summed gated myocardial perfusion images used for

  7. Ventilation-perfusion lung imaging in diaphragmatic paralysis

    International Nuclear Information System (INIS)

    Chopra, S.K.; Taplin, G.V.

    1977-01-01

    Clinical, radiological, physiological, and lung imaging findings from a patient with paralysis of the diaphragm are described. Dyspnea, hypoxemia and hypercapnia increased when the patient changed from the upright to the supine positions. Ventilation (V) and perfusion (P) images of the right lung appeared to be relatively normal and remained nearly the same in the upright and supine positions. In contrast, V/P images of the left lung were smaller than those of the right lung in the upright position and decreased further in the supine position. In addition, the size of the ventilation image was much smaller than that of the perfusion

  8. Associations between muscle perfusion and symptoms in knee osteoarthritis

    DEFF Research Database (Denmark)

    Bandak, E; Boesen, M; Bliddal, H

    2015-01-01

    -MRI and clinical data were analyzed in 94 patients. The typical participant was a woman with a mean age of 65 years, and a body mass index (BMI) of 32 kg/m(2). Reduced multiple regression models analyzing the association between KOOS and DCE-MRI perfusion variables of Total Muscle Volume showed a statistically...... significant association between Nvoxel% and KOOS pain (0.41 (SE 0.14); P = 0.0048). Nvoxel% was defined as the proportion of highly perfused voxels; i.e., the voxels that show an early and rapid increase on the signal intensity vs time curves, reach a plateau state (plateau pattern) and then showing...

  9. Diffusion, Perfusion, and Histopathologic Characteristics of Desmoplastic Infantile Ganglioglioma.

    Science.gov (United States)

    Ho, Chang Y; Gener, Melissa; Bonnin, Jose; Kralik, Stephen F

    2016-07-01

    We present a case series of a rare tumor, the desmoplastic infantile ganglioglioma (DIG) with MRI diffusion and perfusion imaging quantification as well as histopathologic characterization. Four cases with pathologically-proven DIG had diffusion weighted imaging (DWI) and two of the four had dynamic susceptibility contrast imaging. All four tumors demonstrate DWI findings compatible with low-grade pediatric tumors. For the two cases with perfusion imaging, a higher relative cerebral blood volume was associated with higher proliferation index on histopathology for one of the cases. Our results are discussed in conjunction with a literature review.

  10. Pediatric hemiplegic migraine: susceptibility weighted and MR perfusion imaging abnormality

    International Nuclear Information System (INIS)

    Altinok, Deniz; Agarwal, Ajay; Ascadi, Gyula; Luat, Aimee; Tapos, Daniela

    2010-01-01

    We report on an 11-year-old girl suffering from a typical attack of hemiplegic migraine with characteristic abnormalities in perfusion MR and susceptibility-weighted MR imaging findings. The imaging abnormalities were resolved 48 h after the attack. Susceptibility-weighted MR imaging findings correlated well with the MR perfusion, thus it can be used along with conventional MRI for evaluation of children with complex migraine attacks. Susceptibility-weighted MR imaging might have a diagnostic role in assessing the vascular events in hemiplegic migraine. (orig.)

  11. The diagnosis of renal perfusion abnormalities by sequential CT

    International Nuclear Information System (INIS)

    Treugut, H.; Andersson, I.; Hildell, J.; Nyman, U.; Weibull, H.

    1981-01-01

    Abnormalities of renal perfusion can be recognised more readily by sequential CT than by plain CT scan or after static enhancement with contrast medium. Haemodynamically significant stenoses of the renal arteries and total, or partial, infarcts can be diagnosed in this way. Intrarenal and capsular collaterals can be recognised by slow contrast accumulation in the infarcted area, or by the development of contrast in the sub-capsular portion of the cortex. Renal cortical necrosis is very well demonstrated by the absence of cortical perfusion; this is seen, for instance, in the DIC syndrome or during rejection after renal transplant. (orig.) [de

  12. Prognostic Value of Quantitative Stress Perfusion Cardiac Magnetic Resonance.

    Science.gov (United States)

    Sammut, Eva C; Villa, Adriana D M; Di Giovine, Gabriella; Dancy, Luke; Bosio, Filippo; Gibbs, Thomas; Jeyabraba, Swarna; Schwenke, Susanne; Williams, Steven E; Marber, Michael; Alfakih, Khaled; Ismail, Tevfik F; Razavi, Reza; Chiribiri, Amedeo

    2018-05-01

    This study sought to evaluate the prognostic usefulness of visual and quantitative perfusion cardiac magnetic resonance (CMR) ischemic burden in an unselected group of patients and to assess the validity of consensus-based ischemic burden thresholds extrapolated from nuclear studies. There are limited data on the prognostic value of assessing myocardial ischemic burden by CMR, and there are none using quantitative perfusion analysis. Patients with suspected coronary artery disease referred for adenosine-stress perfusion CMR were included (n = 395; 70% male; age 58 ± 13 years). The primary endpoint was a composite of cardiovascular death, nonfatal myocardial infarction, aborted sudden death, and revascularization after 90 days. Perfusion scans were assessed visually and with quantitative analysis. Cross-validated Cox regression analysis and net reclassification improvement were used to assess the incremental prognostic value of visual or quantitative perfusion analysis over a baseline clinical model, initially as continuous covariates, then using accepted thresholds of ≥2 segments or ≥10% myocardium. After a median 460 days (interquartile range: 190 to 869 days) follow-up, 52 patients reached the primary endpoint. At 2 years, the addition of ischemic burden was found to increase prognostic value over a baseline model of age, sex, and late gadolinium enhancement (baseline model area under the curve [AUC]: 0.75; visual AUC: 0.84; quantitative AUC: 0.85). Dichotomized quantitative ischemic burden performed better than visual assessment (net reclassification improvement 0.043 vs. 0.003 against baseline model). This study was the first to address the prognostic benefit of quantitative analysis of perfusion CMR and to support the use of consensus-based ischemic burden thresholds by perfusion CMR for prognostic evaluation of patients with suspected coronary artery disease. Quantitative analysis provided incremental prognostic value to visual assessment and

  13. Direct myocardial perfusion imaging in valvular heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Soto, R.C.; Durante, M.L.; Villacorta, E.V.; Torres, J.F.; Monzon, O.P.

    1981-02-01

    Twenty two patients with rheumatic valvular heart disease - 21 having a history of heart failure - were studied using direct coronary injection of /sup 99m/Tc labelled MAA particles during the course of hemodynamic and arteriographic studies. Myocar