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Sample records for radionuclide ischemic perfusion

  1. Perfusion patterns of ischemic stroke on computed tomography perfusion.

    PubMed

    Lin, Longting; Bivard, Andrew; Parsons, Mark W

    2013-09-01

    CT perfusion (CTP) has been applied increasingly in research of ischemic stroke. However, in clinical practice, it is still a relatively new technology. For neurologists and radiologists, the challenge is to interpret CTP results properly in the context of the clinical presentation. In this article, we will illustrate common CTP patterns in acute ischemic stroke using a case-based approach. The aim is to get clinicians more familiar with the information provided by CTP with a view towards inspiring them to incorporate CTP in their routine imaging workup of acute stroke patients.

  2. Perfusion Angiography in Acute Ischemic Stroke

    PubMed Central

    Liebeskind, David S.

    2016-01-01

    Visualization and quantification of blood flow are essential for the diagnosis and treatment evaluation of cerebrovascular diseases. For rapid imaging of the cerebrovasculature, digital subtraction angiography (DSA) remains the gold standard as it offers high spatial resolution. This paper lays out a methodological framework, named perfusion angiography, for the quantitative analysis and visualization of blood flow parameters from DSA images. The parameters, including cerebral blood flow (CBF) and cerebral blood volume (CBV), mean transit time (MTT), time-to-peak (TTP), and Tmax, are computed using a bolus tracking method based on the deconvolution of the time-density curve on a pixel-by-pixel basis. The method is tested on 66 acute ischemic stroke patients treated with thrombectomy and/or tissue plasminogen activator (tPA) and also evaluated on an estimation task with known ground truth. This novel imaging tool provides unique insights into flow mechanisms that cannot be observed directly in DSA sequences and might be used to evaluate the impact of endovascular interventions more precisely. PMID:27446232

  3. New Trends in Radionuclide Myocardial Perfusion Imaging

    PubMed Central

    Hung, Guang-Uei; Wang, Yuh-Feng; Su, Hung-Yi; Hsieh, Te-Chun; Ko, Chi-Lun; Yen, Ruoh-Fang

    2016-01-01

    Radionuclide myocardial perfusion imaging (MPI) with single photon emission computed tomography (SPECT) has been widely used clinically as one of the major functional imaging modalities for patients with coronary artery disease (CAD) for decades. Ample evidence has supported the use of MPI as a useful and important tool in the diagnosis, risk stratification and treatment planning for CAD. Although popular in the United States, MPI has become the most frequently used imaging modality among all nuclear medicine tests in Taiwan. However, it should be acknowledged that MPI SPECT does have its limitations. These include false-positive results due to certain artifacts, false-negative due to balanced ischemia, complexity and adverse reaction arising from current pharmacological stressors, time consuming nature of the imaging procedure, no blood flow quantitation and relatively high radiation exposure. The purpose of this article was to review the recent trends in nuclear cardiology, including the utilization of positron emission tomography (PET) for MPI, new stressor, new SPECT camera with higher resolution and higher sensitivity, dynamic SPECT protocol for blood flow quantitation, new software of phase analysis for evaluation of LV dyssynchrony, and measures utilized for reducing radiation exposure of MPI. PMID:27122946

  4. Characteristics of Misclassified CT Perfusion Ischemic Core in Patients with Acute Ischemic Stroke

    PubMed Central

    Geuskens, Ralph R. E. G.; Borst, Jordi; Lucas, Marit; Boers, A. M. Merel; Berkhemer, Olvert A.; Roos, Yvo B. W. E. M.; van Walderveen, Marianne A. A.; Jenniskens, Sjoerd F. M.; van Zwam, Wim H.; Dippel, Diederik W. J.; Majoie, Charles B. L. M.; Marquering, Henk A.

    2015-01-01

    Background CT perfusion (CTP) is used to estimate the extent of ischemic core and penumbra in patients with acute ischemic stroke. CTP reliability, however, is limited. This study aims to identify regions misclassified as ischemic core on CTP, using infarct on follow-up noncontrast CT. We aim to assess differences in volumetric and perfusion characteristics in these regions compared to areas that ended up as infarct on follow-up. Materials and Methods This study included 35 patients with >100 mm brain coverage CTP. CTP processing was performed using Philips software (IntelliSpace 7.0). Final infarct was automatically segmented on follow-up noncontrast CT and used as reference. CTP and follow-up noncontrast CT image data were registered. This allowed classification of ischemic lesion agreement (core on CTP: rMTT≥145%, aCBV<2.0 ml/100g and infarct on follow-up noncontrast CT) and misclassified ischemic core (core on CTP, not identified on follow-up noncontrast CT) regions. False discovery ratio (FDR), defined as misclassified ischemic core volume divided by total CTP ischemic core volume, was calculated. Absolute and relative CTP parameters (CBV, CBF, and MTT) were calculated for both misclassified CTP ischemic core and ischemic lesion agreement regions and compared using paired rank-sum tests. Results Median total CTP ischemic core volume was 49.7ml (IQR:29.9ml-132ml); median misclassified ischemic core volume was 30.4ml (IQR:20.9ml-77.0ml). Median FDR between patients was 62% (IQR:49%-80%). Median relative mean transit time was 243% (IQR:198%-289%) and 342% (IQR:249%-432%) for misclassified and ischemic lesion agreement regions, respectively. Median absolute cerebral blood volume was 1.59 (IQR:1.43–1.79) ml/100g (P<0.01) and 1.38 (IQR:1.15–1.49) ml/100g (P<0.01) for misclassified ischemic core and ischemic lesion agreement, respectively. All CTP parameter values differed significantly. Conclusion For all patients a considerable region of the CTP ischemic core

  5. [Ischemic heart disease (myocardial perfusion and viability): techniques and results].

    PubMed

    Croisille, P

    2004-10-01

    Over the last two decades, the understanding, diagnosis and treatment of patients with suspected or known coronary artery disease have made tremendous progress, in particular with the help of the development of non-invasive methodologies for assessing myocardial perfusion and viability. Clinically, nuclear medicine techniques (particularly SPECT imaging) have predominated. With the recent technical developments allowing for a combined assessment of perfusion and irreversible damage with late enhancement imaging, MRI will now play a major role in the assessment of ischemic heart disease. PMID:15507837

  6. Radionuclide cerebral perfusion imaging: Normal pattern

    SciTech Connect

    Goldsmith, S.J.; Stritzke, P.; Losonczy, M.; Vallabhajosula, S.; Holan, V.; DaCosta, M.; Muzinic, M.

    1991-12-31

    Regional cerebral perfusion imaging using a new class of {sup 99m}Tc and {sup 123}I labeled compounds which traverse the blood brain barrier and SPECT imaging technology provides an opportunity to assess this physiologic phenomenon during normal cerebral function and as a manifestation of disease in the central nervous system disease. These applications pose a challenge to the nuclear medicine physician for several reasons: (a) the complex and somewhat unfamiliar functional anatomy, (b) the marked regional differences in regional cerebral perfusion at rest, (c) the lack of understanding of the effect of variations in ambient conditions on regional cerebral perfusion. The difficulties in interpretation are augmented by the display itself. There is frequently no difficulty in differentiating between gray and white matter. However, the frequently used {open_quotes}hot body{close_quotes} color maps, introduce a good deal of contrast, producing displays with apparent interruption in regional cortical perfusion whereas black and white displays provide minimal contrast in the regional cortical activity. The authors sought to define how much variation in regional cerebral perfusion is {open_quotes}allowed{close_quotes} under controlled conditions, to establish a basis to interpret if changes in the environment, psychological interventions, or disease states are accompanied by a measurable change. 2 figs., 1 tab.

  7. Carbohydrate utilization by the ischemic perfused heart: an NMR analysis

    SciTech Connect

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

    1987-05-01

    During ischemia, carbohydrate is necessarily the primary fuel for generation of energy by anaerobic glycolysis. The relative contributions of glycogen and exogenous glucose to glycolysis in the ischemic guinea pig heart were determined by /sup 13/C labeling and NMR. Glycogen was labeled by preischemic perfusion with (1-/sup 13/C)glucose. (2-/sup 13/C)glucose was then supplied in fresh perfusate during 17 minutes of ischemia. Insulin was included in each case. The relative contribution of glycogen and glucose to glycolysis was determined from /sup 13/C spectra obtained during ischemia and by analysis of /sup 1/H spectra of lactate isolated from hearts freeze-clamped at the end of ischemia. The relative amounts of (2-/sup 13/C)lactate, (3-/sup 13/C)lactate, and natural abundance lactate produced during ischemia correspond to contributions to glycolysis by (2-/sup 13/C)glucose, (1-/sup 13/C)glycogen, and natural abundance glycogen, respectively. Glucose utilization during 17 minutes of ischemia, determined from integration of labeled lactate peaks from /sup 13/C spectra, increased from 11 to 35% of the labeled carbohydrate utilization when perfusate glucose increased from 3 to 11.7 mM. Analysis of labeled lactate formation as a function of time during ischemia suggests that glucose is preferentially utilized early during the ischemic period. They conclude that glucose can contribute significantly as a fuel source in the ischemic heart; the extent depends on the concentration of glucose available to the heart and on the duration of ischemia.

  8. Ethanol Promotes Arteriogenesis and Restores Perfusion to Chronically Ischemic Myocardium

    PubMed Central

    Lassaletta, Antonio D.; Elmadhun, Nassrene Y.; Liu, Yuhong; Feng, Jun; Burgess, Thomas A.; Karlson, Nicholas W.; Laham, Roger J.; Sellke, Frank W.

    2014-01-01

    Background Moderate alcohol consumption is known to be cardioprotective as compared to either heavy drinking or complete abstinence. We assessed the hypothesis that ethanol supplementation would improve myocardial function in the setting of chronic ischemia. Methods and Results Sixteen male Yorkshire swine underwent placement of an ameroid constrictor to the left circumflex artery to induce chronic myocardial ischemia. Post-operatively animals were supplemented with either 90 ml of ethanol daily (50%/V, EtOH) or 80 g of sucrose of equal caloric value (SUC) serving as controls. Seven weeks after ameroid placement, arteriolar density (1.74 ± 0.210 vs. 3.11 ± 0.368 % area of arterioles per low-powered field in SUC vs. EtOH, p = 0.004), myocardial perfusion (ratio of blood flow to the at-risk myocardium compared to the normal ventricle during demand pacing was 0.585 ± 0.107 vs. 1.08 ± 0.138 for SUC vs. EtOH, p = 0.014), and microvascular reactivity were significantly increased in the ethanol-treated animals compared to controls in the at-risk myocardium. Analysis of VEGF and NOTCH pathway signaling suggested pro-neovascular and proliferative activity in the ischemic area. The average peak blood alcohol level in the treatment group was 40 ± 4 mg/dL consistent with levels of moderate drinking in humans. Conclusions Ethanol supplementation increased arteriolar density and significantly improved myocardial perfusion and endothelium-dependent vasorelaxation in chronically ischemic myocardium. These findings suggest that at moderate doses, ethanol directly promotes vasculogenesis and improves microvascular function resulting in significant improvements in myocardial perfusion in the setting of chronic ischemia. PMID:24030397

  9. Machine Perfusion Enhances Hepatocyte Isolation Yields From Ischemic Livers

    PubMed Central

    Izamis, Maria-Louisa; Perk, Sinem; Calhoun, Candice; Uygun, Korkut; Yarmush, Martin L.; Berthiaume, François

    2015-01-01

    Background High-quality human hepatocytes form the basis of drug safety and efficacy tests, cell-based therapies, and bridge-to-transplantation devices. Presently the only supply of cells derives from an inadequate pool of suboptimal disqualified donor livers. Here we evaluated whether machine perfusion could ameliorate ischemic injury that many of these livers experience prior to hepatocyte isolation. Methods Non-heparinized female Lewis rat livers were exposed to an hour of warm ischemia (34°C) and then perfused for 3 hours. Five different perfusion conditions that utilized the cell isolation apparatus were investigated, namely: (1) modified Williams Medium E and (2) Lifor, both with active oxygenation (95%O2/5%CO2), as well as (3) Lifor passively oxygenated with ambient air (21%O2/0.04%CO2), all at ambient temperatures (20±2°C). At hypothermic temperatures (5±1°C) and under passive oxygenation were (4) University of Wisconsin solution (UW) and (5) Vasosol. Negative and positive control groups comprised livers that had ischemia (WI) and livers that did not (Fresh) prior to cell isolation, respectively. Results Fresh livers yielded 32±9 million cells/g liver while an hour of ischemia reduced the cell yield to 1.6±0.6 million cells/g liver. Oxygenated Williams medium E and Lifor recovered yields of 39±11 and 31±2.3 million cells/g liver, respectively. The passively oxygenated groups produced 15±7 (Lifor), 13±7 (Vasosol), and 10±6 (UW) million cells/g liver. Oxygenated Williams Medium E was most effective at sustaining pH values, avoiding the accumulation of lactate, minimizing edematous weight gain and producing bile during perfusion. Conclusions Machine perfusion results in a dramatic increase in cell yields from livers that have had up to an hour of warm ischemia, but perfusate choice significantly impacts the extent of recovery. Oxygenated Williams Medium E at room temperature is superior to Lifor, UW and Vasosol, largely facilitated by its high

  10. Approaches to reducing radiation dose from radionuclide myocardial perfusion imaging.

    PubMed

    Dorbala, Sharmila; Blankstein, Ron; Skali, Hicham; Park, Mi-Ae; Fantony, Jolene; Mauceri, Charles; Semer, James; Moore, Stephen C; Di Carli, Marcelo F

    2015-04-01

    Radionuclide myocardial perfusion imaging (MPI) plays a vital role in the evaluation and management of patients with coronary artery disease. However, because of a steep growth in MPI in the mid 2000s, concerns about inappropriate use of MPI and imaging-related radiation exposure increased. In response, the professional societies developed appropriate-use criteria for MPI. Simultaneously, novel technology, image-reconstruction software for traditional scanners, and dedicated cardiac scanners emerged and facilitated the performance of MPI with low-dose and ultra-low-dose radiotracers. This paper provides a practical approach to performing low-radiation-dose MPI using traditional and novel technologies. PMID:25766891

  11. Simple Machine Perfusion Significantly Enhances Hepatocyte Yields of Ischemic and Fresh Rat Livers

    PubMed Central

    Izamis, Maria-Louisa; Calhoun, Candice; Uygun, Basak E.; Guzzardi, Maria Angela; Price, Gavrielle; Luitje, Martha; Saeidi, Nima; Yarmush, Martin L.; Uygun, Korkut

    2013-01-01

    The scarcity of viable hepatocytes is a significant bottleneck in cell transplantation, drug discovery, toxicology, tissue engineering, and bioartificial assist devices, where trillions of high-functioning hepatocytes are needed annually. We took the novel approach of using machine perfusion to maximize cell recovery, specifically from uncontrolled cardiac death donors, the largest source of disqualified donor organs. In a rat model, we developed a simple 3-h room temperature (20 ± 2°C) machine perfusion protocol to treat nonpremedicated livers exposed to 1 h of warm (34°C) ischemia. Treated ischemic livers were compared to fresh, fresh-treated, and untreated ischemic livers using viable hepatocyte yields and in vitro performance as quantitative endpoints. Perfusion treatment resulted in both a 25-fold increase in viable hepatocytes from ischemic livers and a 40% increase from fresh livers. While cell morphology and function in suspension and plate cultures of untreated warm ischemic cells was significantly impaired, treated warm ischemic cells were indistinguishable from fresh hepatocytes. Furthermore, a strong linear correlation between tissue ATP and cell yield enabled accurate evaluation of the extent of perfusion recovery. Maximal recovery of warm ischemic liver ATP content appears to be correlated with optimal flow through the microvasculature. These data demonstrate that the inclusion of a simple perfusion-preconditioning step can significantly increase the efficiency of functional hepatocyte yields and the number of donor livers that can be gainfully utilized. PMID:25431743

  12. Imaging findings and cerebral perfusion in arterial ischemic stroke due to transient cerebral arteriopathy in children.

    PubMed

    Barbosa Junior, Alcino Alves; Ellovitch, Saada Resende de Souza; Pincerato, Rita de Cassia Maciel

    2012-01-01

    We report the case of a 4-year-old female child who developed an arterial ischemic stroke in the left middle cerebral artery territory, due to a proximal stenosis of the supraclinoid internal carotid artery, most probably related to transient cerebral arteriopathy of childhood. Computed tomography scan, magnetic resonance imaging, perfusion magnetic resonance and magnetic resonance angiography are presented, as well as follow-up by magnetic resonance and magnetic resonance angiography exams. Changes in cerebral perfusion and diffusion-perfusion mismatch call attention. As far as we know, this is the first report of magnetic resonance perfusion findings in transient cerebral arteriopathy.

  13. Whole-Brain CT Perfusion to Quantify Acute Ischemic Penumbra and Core.

    PubMed

    Lin, Longting; Bivard, Andrew; Krishnamurthy, Venkatesh; Levi, Christopher R; Parsons, Mark W

    2016-06-01

    Purpose To validate the use of perfusion computed tomography (CT) with whole-brain coverage to measure the ischemic penumbra and core and to compare its performance to that of limited-coverage perfusion CT. Materials and Methods Institutional ethics committee approval and informed consent were obtained. Patients (n = 296) who underwent 320-detector CT perfusion within 6 hours of the onset of ischemic stroke were studied. First, the ischemic volume at CT perfusion was compared with the penumbra and core reference values at magnetic resonance (MR) imaging to derive CT perfusion penumbra and core thresholds. Second, the thresholds were tested in a different group of patients to predict the final infarction at diffusion-weighted imaging 24 hours after CT perfusion. Third, the change in ischemic volume delineated by the optimal penumbra and core threshold was determined as the brain coverage was gradually reduced from 160 mm to 20 mm. The Wilcoxon signed-rank test, concordance correlation coefficient (CCC), and analysis of variance were used for the first, second, and third steps, respectively. Results CT perfusion at penumbra and core thresholds resulted in the least volumetric difference from MR imaging reference values with delay times greater than 3 seconds and delay-corrected cerebral blood flow of less than 30% (P = .34 and .33, respectively). When the thresholds were applied to the new group of patients, prediction of the final infarction was allowed with delay times greater than 3 seconds in patients with no recanalization of the occluded artery (CCC, 0.96 [95% confidence interval: 0.92, 0.98]) and with delay-corrected cerebral blood flow less than 30% in patients with complete recanalization (CCC, 0.91 [95% confidence interval: 0.83, 0.95]). However, the ischemic volume with a delay time greater than 3 seconds was underestimated when the brain coverage was reduced to 80 mm (P = .04) and the core volume measured as cerebral blood flow less than 30% was

  14. Radionuclide Tracers for Myocardial Perfusion Imaging and Blood Flow Quantification.

    PubMed

    deKemp, Robert A; Renaud, Jennifer M; Klein, Ran; Beanlands, Rob S B

    2016-02-01

    Myocardial perfusion imaging is performed most commonly using Tc-99m-sestamibi or tetrofosmin SPECT as well as Rb-82-rubidium or N-13-ammonia PET. Diseased-to-normal tissue contrast is determined by the tracer retention fraction, which decreases nonlinearly with flow. Reduced tissue perfusion results in reduced tracer retention, but the severity of perfusion defects is typically underestimated by 20% to 40%. Compared to SPECT, retention of the PET tracers is more linearly related to flow, and therefore, the perfusion defects are measured more accurately using N-13-ammonia or Rb-82. PMID:26590778

  15. Phase-based metamorphosis of diffusion lesion in relation to perfusion values in acute ischemic stroke.

    PubMed

    Rekik, Islem; Allassonnière, Stéphanie; Luby, Marie; Carpenter, Trevor K; Wardlaw, Joanna M

    2015-01-01

    Examining the dynamics of stroke ischemia is limited by the standard use of 2D-volume or voxel-based analysis techniques. Recently developed spatiotemporal models such as the 4D metamorphosis model showed promise for capturing ischemia dynamics. We used a 4D metamorphosis model to evaluate acute ischemic stroke lesion morphology from the acute diffusion-weighted imaging (DWI) to final T2-weighted imaging (T2-w). In 20 representative patients, we metamorphosed the acute lesion to subacute lesion to final infarct. From the DWI lesion deformation maps we identified dynamic lesion areas and examined their association with perfusion values inside and around the lesion edges, blinded to reperfusion status. We then tested the model in ten independent patients from the STroke Imaging Repository (STIR). Perfusion values varied widely between and within patients, and were similar in contracting and expanding DWI areas in many patients in both datasets. In 25% of patients, the perfusion values were higher in DWI-contracting than DWI-expanding areas. A similar wide range of perfusion values and ongoing expansion and contraction of the DWI lesion were seen subacutely. There was more DWI contraction and less expansion in patients who received thrombolysis, although with widely ranging perfusion values that did not differ. 4D metamorphosis modeling shows promise as a method to improve use of multimodal imaging to understand the evolution of acute ischemic tissue towards its fate. PMID:26288755

  16. Arterial Spin Labeling Measurements of Cerebral Perfusion Territories in Experimental Ischemic Stroke

    PubMed Central

    Leoni, Renata F.; Paiva, Fernando F.; Kang, Byeong-Teck; Henning, Erica C.; Nascimento, George C.; Tannús, Alberto; De Araújo, Dráulio B.; Silva, Afonso C.

    2016-01-01

    Collateral circulation, defined as the supplementary vascular network that maintains cerebral blood flow (CBF) when the main vessels fail, constitutes one important defense mechanism of the brain against ischemic stroke. In the present study, continuous arterial spin labeling (CASL) was used to quantify CBF and obtain perfusion territory maps of the major cerebral arteries in spontaneously hypertensive rats (SHR) and their normotensive Wistar-Kyoto (WKY) controls. Results show that both WKY and SHR have complementary, yet significantly asymmetric perfusion territories. Right or left dominances were observed in territories of the anterior (ACA), middle and posterior cerebral arteries, and the thalamic artery. Magnetic resonance angiography showed that some of the asymmetries were correlated with variations of the ACA. The leptomeningeal circulation perfusing the outer layers of the cortex was observed as well. Significant and permanent changes in perfusion territories were obtained after temporary occlusion of the right middle cerebral artery in both SHR and WKY, regardless of their particular dominance. However, animals with right dominance presented a larger volume change of the left perfusion territory (23 ± 9%) than animals with left dominance (7 ± 5%, P < 0.002). The data suggest that animals with contralesional dominance primarily safeguard local CBF values with small changes in contralesional perfusion territory, while animals with ipsilesional dominance show a reversal of dominance and a substantial increase in contralesional perfusion territory. These findings show the usefulness of CASL to probe the collateral circulation. PMID:24323754

  17. Automated CT Perfusion for Ischemic Core Volume Prediction in Tandem Anterior Circulation Occlusions

    PubMed Central

    Haussen, Diogo C.; Dehkharghani, Seena; Grigoryan, Mikayel; Bowen, Meredith; Rebello, Leticia C.; Nogueira, Raul G.

    2016-01-01

    Background/Aim CT perfusion (CTP) predicts ischemic core volumes in acute ischemic stroke (AIS); however, assumptions made within the pharmacokinetic model may engender errors by the presence of tracer delay or dispersion. We aimed to evaluate the impact of hemodynamic disturbance due to extracranial anterior circulation occlusions upon the accuracy of ischemic core volume estimation with an automated perfusion analysis tool (RAPID) among AIS patients with large-vessel occlusions. Methods A prospectively collected, interventional database was retrospectively reviewed for all cases of endovascular treatment of AIS between September 2010 and March 2015 for patients with anterior circulation occlusions with baseline CTP and full reperfusion (mTICI3). Results Out of 685 treated patients, 114 fit the inclusion criteria. Comparison between tandem (n = 21) and nontandem groups (n = 93) revealed similar baseline ischemic core (20 ± 19 vs. 19 ± 25 cm3; p = 0.8), Tmax >6 s (175 ± 109 vs. 162 ± 118 cm3; p = 0.6), Tmax >10 s (90 ± 84 vs. 90 ± 91 cm3; p = 0.9), and final infarct volumes (45 ± 47 vs. 37 ± 45 cm3; p = 0.5). Baseline core volumes were found to correlate with final infarct volumes for the tandem (r = 0.49; p = 0.02) and nontandem (r = 0.44; p < 0.01) groups. The mean absolute difference between estimated core and final infarct volume was similar between patients with and those without (24 ± 41 vs. 17 ± 41 cm3; p = 0.5) tandem lesions. Conclusions The prediction of baseline ischemic core volumes through an optimized CTP analysis employing rigorous normalization, thresholding, and voxel-wise analysis is not significantly influenced by the presence of underlying extracranial carotid steno-occlusive disease in large-vessel AIS.

  18. Ghrelin protects musculocutaneous tissue from ischemic necrosis by improving microvascular perfusion.

    PubMed

    Rezaeian, F; Wettstein, R; Scheuer, C; Bäumker, K; Bächle, A; Vollmar, B; Menger, M D; Harder, Y

    2012-02-01

    Persistent ischemia in musculocutaneous tissue may lead to wound breakdown and necrosis. The objective of this experimental study was to analyze, whether the gastric peptide ghrelin prevents musculocutaneous tissue from necrosis and to elucidate underlying mechanisms. Thirty-two C57BL/6 mice equipped with a dorsal skinfold chamber containing ischemic musculocutaneous tissue were allocated to four groups: 1) ghrelin; 2) N(ω)-nitro-l-arginine methyl ester (l-NAME); 3) ghrelin and l-NAME; and 4) control. Microcirculation, inflammation, angiogenesis, and tissue survival were assessed by fluorescence microscopy. Inducible and endothelial nitric oxide synthase (iNOS I and eNOS), vascular endothelial growth factor (VEGF), as well as nuclear factor κB (NF-κB) were assessed by Western blot analysis. Ghrelin-treated animals showed an increased expression of iNOS and eNOS in critically perfused tissue compared with controls. This was associated with arteriolar dilation, increased arteriolar perfusion, and a sustained functional capillary density. Ghrelin further upregulated NF-κB and VEGF and induced angiogenesis. Finally, ghrelin reduced microvascular leukocyte-endothelial cell interactions, apoptosis, and overall tissue necrosis (P < 0.05 vs. control). Inhibition of nitric oxide by l-NAME did not affect the anti-inflammatory and angiogenic action of ghrelin but completely blunted the ghrelin-induced tissue protection by abrogating the arteriolar dilation, the improved capillary perfusion, and the increased tissue survival. Ghrelin prevents critically perfused tissue from ischemic necrosis. Tissue protection is the result of a nitric oxide synthase-mediated improvement of the microcirculation but not due to induction of angiogenesis or attenuation of inflammation. This might represent a promising, noninvasive, and clinically applicable approach to protect musculocutaneous tissue from ischemia. PMID:22159999

  19. Effectiveness of CT Computed Tomography Perfusion in Diagnostics of Acute Ischemic Stroke

    PubMed Central

    Menzilcioglu, Mehmet Sait; Mete, Ahmet; Ünverdi, Zeyni

    2015-01-01

    Summary Background Stroke is the third most common death reason after the cardiovascular disorders and cancer. Cerebral ischemia is a pathology that stems from a decrease in cerebral perfusion. Computed Tomography Perfusion (CTP) is an additional method to the conventional Computed Tomography (CT) that could be performed by using developed softwares, in a short period of time and with a low risk of complications. CTP not only allows early detection of cerebral ischemia but also gives valuable information on the ischemic penumbra which are very important in early diagnosis and treatment. Acute Ischemic Stroke (AIS) can be cured by trombolytic treapy within 3–6 hours after symptom onset. Since rapid screening and accurate diagnosis increase the success of the treatment, the role of neuroradiology in acute ischemia diagnostics and treatment has become more important. Our aim was to define CT skills in early diagnosis of AIS, to define its contribution to patient’s diagnosis and treatment and to define its importance regarding patient’s prognosis. Material/Methods We included 42 patients that presented to the emergency service and neurology outpatient clinic with the symptoms of acute cerebral incidence. Results In our study, we found that Cerebral Blood Flow (CBF) is 90.91% sensitive and 100% specific in examining ischemia. Conclusions Tissue hemodynamic data, especially sensitivity and specificity rates, which cannot be acquired by conventional CT and MRI methods, can be acquired by the CTP method. PMID:26740827

  20. The evaluation of ischemic heart disease using thallium-210 with comments on radionuclide angiography

    SciTech Connect

    Leppo, J.A.; Scheuer, J.; Pohost, G.M.; Freeman, L.M.; Strauss, H.W.

    1980-04-01

    Coronary artery disease causing myocardial ischemia and infarction is the leading cause of death in America. Methods that can be used to diagnose and follow the response to therapy of coronary artery disease or its effect on myocardial ischemia should help control the morbidity and mortality of ischemic heart disease. The use of ECG monitoring is less sensitive and specific for ischemia than thallium (TI) imaging or the use of radionuclide angiography (RNA). In large patient populations, the findings of a positive ECG and TI or RNA study will be highly predictive for the presence of coronary artery disease, while negative test results make the disease unlikely. A combined approach to the patient with possible ischemic heart disease is presented.

  1. Gene electro transfer of plasmid encoding vascular endothelial growth factor for enhanced expression and perfusion in the ischemic swine heart.

    PubMed

    Hargrave, Barbara; Strange, Robert; Navare, Sagar; Stratton, Michael; Burcus, Nina; Murray, Len; Lundberg, Cathryn; Bulysheva, Anna; Li, Fanying; Heller, Richard

    2014-01-01

    Myocardial ischemia can damage heart muscle and reduce the heart's pumping efficiency. This study used an ischemic swine heart model to investigate the potential for gene electro transfer of a plasmid encoding vascular endothelial growth factor for improving perfusion and, thus, for reducing cardiomyopathy following acute coronary syndrome. Plasmid expression was significantly greater in gene electro transfer treated tissue compared to injection of plasmid encoding vascular endothelial growth factor alone. Higher gene expression was also seen in ischemic versus non-ischemic groups with parameters 20 Volts (p<0.03), 40 Volts (p<0.05), and 90 Volts (p<0.05), but not with 60 Volts (p<0.09) while maintaining a pulse width of 20 milliseconds. The group with gene electro transfer of plasmid encoding vascular endothelial growth factor had increased perfusion in the area at risk compared to control groups. Troponin and creatine kinase increased across all groups, suggesting equivalent ischemia in all groups prior to treatment. Echocardiography was used to assess ejection fraction, cardiac output, stroke volume, left ventricular end diastolic volume, and left ventricular end systolic volume. No statistically significant differences in these parameters were detected during a 2-week time period. However, directional trends of these variables were interesting and offer valuable information about the feasibility of gene electro transfer of vascular endothelial growth factor in the ischemic heart. The results demonstrate that gene electro transfer can be applied safely and can increase perfusion in an ischemic area. Additional study is needed to evaluate potential efficacy.

  2. Coronary microcirculation changes in non-ischemic dilated cardiomyopathy identified by novel perfusion CT

    PubMed Central

    Miller, Wayne L.; Behrenbeck, Thomas R.; McCollough, Cynthia H.; Williamson, Eric E.; Leng, Shuai; Kline, Timothy L.

    2015-01-01

    Intramyocardial microvessels demonstrate functional changes in cardiomyopathies. However, clinical computed tomography (CT) does not have adequate spatial resolution to assess the microvessels. Our hypothesis is that these functional changes manifest as altered heterogeneity of the spatial distribution of arteriolar perfusion territories. Our goal was to determine whether the spatial analysis of perfusion CT could clinically detect changes in the function and structure of the intramyocardial microcirculation in a non-ischemic dilated cardiomyopathy (DCM). Two groups were studied: (1) a Control group (12 male plus 12 female) with no risk factors nor evidence of coronary artery disease, and (2) a DCM group (12 male plus 12 female)with left ventricular ejection fraction ≤40 %and no evidence of coronary artery disease. Using the CT scan, the LV free wall thickness and its radius of curvature were measured. The DCM group was sub divided into those with LV free wall thickness <11.5 mm and those with thickness≥11.5 mm. In themyocardial opacification phase of the CT scan sequence, myocardial perfusion (F) and intramyocardial blood volume (Bv) for multiple intramyocardial regions were computed. No significant differences between the groups were demonstrable in overall myocardial F or Bv. However, the myocardial regional data showed significantly increased spatial heterogeneity in the DCM group when compared to the Control group. The findings demonstrate that altered function of the subresolution intramyocardial microcirculation can be quantified with myocardial perfusion CT and that significant changes in these parameters occur in the DCM subjects with LV wall thickness greater than 11.5 mm. PMID:25712168

  3. End-ischemic machine perfusion reduces bile duct injury in donation after circulatory death rat donor livers independent of the machine perfusion temperature.

    PubMed

    Westerkamp, Andrie C; Mahboub, Paria; Meyer, Sophie L; Hottenrott, Maximilia; Ottens, Petra J; Wiersema-Buist, Janneke; Gouw, Annette S H; Lisman, Ton; Leuvenink, Henri G D; Porte, Robert J

    2015-10-01

    A short period of oxygenated machine perfusion (MP) after static cold storage (SCS) may reduce biliary injury in donation after cardiac death (DCD) donor livers. However, the ideal perfusion temperature for protection of the bile ducts is unknown. In this study, the optimal perfusion temperature for protection of the bile ducts was assessed. DCD rat livers were preserved by SCS for 6 hours. Thereafter, 1 hour of oxygenated MP was performed using either hypothermic machine perfusion, subnormothermic machine perfusion, or with controlled oxygenated rewarming (COR) conditions. Subsequently, graft and bile duct viability were assessed during 2 hours of normothermic ex situ reperfusion. In the MP study groups, lower levels of transaminases, lactate dehydrogenase (LDH), and thiobarbituric acid reactive substances were measured compared to SCS. In parallel, mitochondrial oxygen consumption and adenosine triphosphate (ATP) production were significantly higher in the MP groups. Biomarkers of biliary function, including bile production, biliary bicarbonate concentration, and pH, were significantly higher in the MP groups, whereas biomarkers of biliary epithelial injury (biliary gamma-glutamyltransferase [GGT] and LDH), were significantly lower in MP preserved livers. Histological analysis revealed less injury of large bile duct epithelium in the MP groups compared to SCS. In conclusion, compared to SCS, end-ischemic oxygenated MP of DCD livers provides better preservation of biliary epithelial function and morphology, independent of the temperature at which MP is performed. End-ischemic oxygenated MP could reduce biliary injury after DCD liver transplantation.

  4. Perfusion Imaging in the 3 Hour Time Window Predicts a tPA-Associated Hemorrhage in Acute Ischemic Stroke

    PubMed Central

    Rangaraju, Srikant; Edwards, Adam; Dehkharghani, Seena; Nahab, Fadi

    2015-01-01

    Perfusion imaging is being evaluated in acute ischemic stroke patients to identify those who may benefit from reperfusion therapies beyond standard thrombolytic time windows but limited data is available on its utility in patients presenting within standard thrombolytic time windows. We report a case of a patient presenting within the 3 hour time window where computerized tomographic perfusion imaging before intravenous thrombolysis identified a large volume of severely ischemic tissue and where intravenous tissue plasminogen activator (tPA) administration subsequently resulted in a fatal intracerebral hemorrhage. Whether perfusion imaging can predict an increased risk of tPA-associated symptomatic hemorrhage in patients presenting within standard thrombolytic time windows requires further study. PMID:25692511

  5. Mutant hypoxia inducible factor-1α improves angiogenesis and tissue perfusion in ischemic rabbit skeletal muscle.

    PubMed

    Li, Mingyan; Liu, Cheng; Bin, Jianping; Wang, Yuegang; Chen, Jianwei; Xiu, Jiancheng; Pei, Jingxian; Lai, Yanxian; Chen, Dongdong; Fan, Caixia; Xie, Jiajia; Tao, Yu; Wu, Pingsheng

    2011-01-01

    Hypoxia-inducible factor-1α (HIF-1α) is one of the most potent angiogenic growth factors. It regulates genes involved in angiogenesis, but is inactivated rapidly by normoxia. Ad-HIF-1α-Trip was constructed by transforming Pro402, Pro564, and Asn803 in HIF-1α to alanine in order to delay degradation and create a constitutive transcriptional activator. In this study, we investigated whether Ad-HIF-1α-Trip could induce functional mature angiogenesis and the possible mechanisms involved. We found that Ad-HIF-1α-Trip increased the expression of multiple angiogenic genes in cultured HMVEC-Ls, including VEGF, PLGF, PAI-1, and PDGF. In a rabbit model of acute hind limb ischemia, Ad-HIF-1α-Trip improved tissue perfusion and collateral vessels, as measured by contrast-enhanced ultrasound (CEU), CT angiography, and vascular casting. Ad-HIF-1α-Trip also produced more histologically identifiable capillaries, which were verified by immunostaining, compared with controls. Interestingly, inhibition of CBP/p300 by curcumin prevented HIF-1α from inducing the expression of several angiogenic genes. The present study suggests that Ad-HIF-1α-Trip can induce mature angiogenesis and improve tissue perfusion in ischemic rabbit skeletal muscle. CBP/p300, which interacts with the transactivation domains of HIF-1α, is important for HIF-1α-induced transcription of angiogenic genes. PMID:20937289

  6. High frequency QRS ECG predicts ischemic defects during myocardial perfusion imaging

    NASA Technical Reports Server (NTRS)

    Rahman, Atiar

    2006-01-01

    Background: Changes in high frequency QRS components of the electrocardiogram (HF QRS ECG) (150-250 Hz) are more sensitive than changes in conventional ST segments for detecting myocardial ischemia. We investigated the accuracy of 12-lead HF QRS ECG in detecting ischemia during adenosine tetrofosmin myocardial perfusion imaging (MPI). Methods and Results: 12-lead HF QRS ECG recordings were obtained from 45 patients before and during adenosine technetium-99 tetrofosmin MPI tests. Before the adenosine infusions, recordings of HF QRS were analyzed according to a morphological score that incorporated the number, type and location of reduced amplitude zones (RAZs) present in the 12 leads. During the adenosine infusions, recordings of HF QRS were analyzed according to the maximum percentage changes (in both the positive and negative directions) that occurred in root mean square (RMS) voltage amplitudes within the 12 leads. The best set of prospective HF QRS criteria had a sensitivity of 94% and a specificity of 83% for correctly identifying the MPI result. The sensitivity of simultaneous ST segment changes (18%) was significantly lower than that of any individual HF QRS criterion (P<0.001). Conclusions: Analysis of 12-lead HF QRS ECG is highly sensitive and specific for detecting ischemic perfusion defects during adenosine MPI stress tests and significantly more sensitive than analysis of conventional ST segments.

  7. High frequency QRS ECG predicts ischemic defects during myocardial perfusion imaging

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Changes in high frequency QRS components of the electrocardiogram (HF QRS ECG) (150-250 Hz) are more sensitive than changes in conventional ST segments for detecting myocardial ischemia. We investigated the accuracy of 12-lead HF QRS ECG in detecting ischemia during adenosine tetrofosmin myocardial perfusion imaging (MPI). 12-lead HF QRS ECG recordings were obtained from 45 patients before and during adenosine technetium-99 tetrofosmin MPI tests. Before the adenosine infusions, recordings of HF QRS were analyzed according to a morphological score that incorporated the number, type and location of reduced amplitude zones (RAZs) present in the 12 leads. During the adenosine infusions, recordings of HF QRS were analyzed according to the maximum percentage changes (in both the positive and negative directions) that occurred in root mean square (RMS) voltage amplitudes within the 12 leads. The best set of prospective HF QRS criteria had a sensitivity of 94% and a specificity of 83% for correctly identifying the MPI result. The sensitivity of simultaneous ST segment changes (18%) was significantly lower than that of any individual HF QRS criterion (P less than 0.00l). Analysis of 12-lead HF QRS ECG is highly sensitive and specific for detecting ischemic perfusion defects during adenosine MPI stress tests and significantly more sensitive than analysis of conventional ST segments.

  8. Automated prediction of tissue outcome after acute ischemic stroke in computed tomography perfusion images

    NASA Astrophysics Data System (ADS)

    Vos, Pieter C.; Bennink, Edwin; de Jong, Hugo; Velthuis, Birgitta K.; Viergever, Max A.; Dankbaar, Jan Willem

    2015-03-01

    Assessment of the extent of cerebral damage on admission in patients with acute ischemic stroke could play an important role in treatment decision making. Computed tomography perfusion (CTP) imaging can be used to determine the extent of damage. However, clinical application is hindered by differences among vendors and used methodology. As a result, threshold based methods and visual assessment of CTP images has not yet shown to be useful in treatment decision making and predicting clinical outcome. Preliminary results in MR studies have shown the benefit of using supervised classifiers for predicting tissue outcome, but this has not been demonstrated for CTP. We present a novel method for the automatic prediction of tissue outcome by combining multi-parametric CTP images into a tissue outcome probability map. A supervised classification scheme was developed to extract absolute and relative perfusion values from processed CTP images that are summarized by a trained classifier into a likelihood of infarction. Training was performed using follow-up CT scans of 20 acute stroke patients with complete recanalization of the vessel that was occluded on admission. Infarcted regions were annotated by expert neuroradiologists. Multiple classifiers were evaluated in a leave-one-patient-out strategy for their discriminating performance using receiver operating characteristic (ROC) statistics. Results showed that a RandomForest classifier performed optimally with an area under the ROC of 0.90 for discriminating infarct tissue. The obtained results are an improvement over existing thresholding methods and are in line with results found in literature where MR perfusion was used.

  9. MRI monitoring of function, perfusion and viability in microembolized moderately ischemic myocardium.

    PubMed

    Do, Loi; Wilson, Mark W; Krug, Roland; Hetts, Steven W; Saeed, Maythem

    2015-08-01

    Assessment of microembolization after coronary interventions is clinically challenging, thus we longitudinally investigated microemboli effects on moderately ischemic myocardium using MRI and histopathology. Twenty-four pigs (8/group) were divided into: group I (no intervention), group II (45 min LAD occlusion) and group III (45 min LAD occlusion with microembolization). Cine, perfusion and delayed contrast enhanced MRI (DE-MRI), using 1.5T MRI, were used for assessment at 3 days and 5 weeks. Triphenyltetrazolium-chloride (TTC) and Masson-trichrome were used as gold standard references for macro and microscopic quantification of myocardial infarction (MI). Cine MRI showed differential increase in end systolic volume (1.3 ± 0.08 ml/kg group II and 1.6 ± 0.1 ml/kg group III) and decrease in ejection fraction (45 ± 2 and 36 ± 2%, respectively) compared with controls at 3 days (2.1 ± 0.1 ml ESV and 50 ± 1% EF, P < 0.05). At 5 weeks group III, but not II, showed persistent perfusion deficits, wall thinning in the LAD territory and compensatory hypertrophy in remote myocardium. DE-MRI MI at 3 days was significantly smaller in group II (3.3 ± 2.2 g) than III (9.8 ± 0.6 g), at 5 weeks, MI were smaller by 60% (1.3 ± 0.9 g) and 22% (7.7 ± 0.5 g), respectively. TTC MI was similar to DE-MRI in group II (1.6 ± 1.0 g) and III (9.2 ± 1.6 g), but not microscopy (2.8 ± 0.4 and 10.5 ± 1.5 g, respectively). The effects of moderate ischemia with and without microembolization on myocardium could be differentiated using multiple MRI sequences. MRI demonstrated that microemboli in moderately ischemic myocardium, but not solely ischemia, prolonged ventricular dysfunction, created perfusion deficits, poor infarct resorption and enhanced compensatory hypertrophy, while moderate ischemia alone caused minor LV changes.

  10. Defining Core and Penumbra in Ischemic Stroke: A Voxel- and Volume-Based Analysis of Whole Brain CT Perfusion.

    PubMed

    Yu, Yannan; Han, Quan; Ding, Xinfa; Chen, Qingmeng; Ye, Keqi; Zhang, Sheng; Yan, Shenqiang; Campbell, Bruce C V; Parsons, Mark W; Wang, Shaoshi; Lou, Min

    2016-01-01

    Whole brain computed tomography perfusion (CTP) has the potential to select eligible patients for reperfusion therapy. We aimed to find the optimal thresholds on baseline CTP for ischemic core and penumbra in acute ischemic stroke. We reviewed patients with acute ischemic stroke in the anterior circulation, who underwent baseline whole brain CTP, followed by intravenous thrombolysis and perfusion imaging at 24 hours. Patients were divided into those with major reperfusion (to define the ischemic core) and minimal reperfusion (to define the extent of penumbra). Receiver operating characteristic (ROC) analysis and volumetric consistency analysis were performed separately to determine the optimal threshold by Youden's Index and mean magnitude of volume difference, respectively. From a series of 103 patients, 22 patients with minimal-reperfusion and 47 with major reperfusion were included. Analysis revealed delay time ≥ 3 s most accurately defined penumbra (AUC = 0.813; 95% CI, 0.812-0.814, mean magnitude of volume difference = 29.1 ml). The optimal threshold for ischemic core was rCBF ≤ 30% within delay time ≥ 3 s (AUC = 0.758; 95% CI, 0.757-0.760, mean magnitude of volume difference = 10.8 ml). In conclusion, delay time ≥ 3 s and rCBF ≤ 30% within delay time ≥ 3 s are the optimal thresholds for penumbra and core, respectively. These results may allow the application of the mismatch on CTP to reperfusion therapy.

  11. Radionuclide imaging of myocardial perfusion and viability in assessment of acute myocardial infarction

    SciTech Connect

    Berman, D.S.; Kiat, H.; Maddahi, J.; Shah, P.K.

    1989-07-18

    Technical advances in radionuclide imaging have important implications for the management of patients with acute myocardial infarction. Single-photon emission computerized tomography with thallium 201 (TI-201) offers greater accuracy than planar imaging in detecting, localizing and sizing myocardial perfusion defects. Use of single-photon emission computerized tomography with TI-201 should allow for a more accurate assessment of prognosis after myocardial infarction. A new radiopharmaceutical, technetium 99-m methoxyisobutyl isonitrile, provides a number of advantages over TI-201, including higher quality images, lack of redistribution, and the ability to assess first-pass ventricular function. Applications of TI-201 and technetium 99-m methoxyisobutyl isonitrile include assessment of arterial patency and myocardial salvage immediately after thrombolytic therapy, detection of resting ischemia after thrombolytic therapy, targeting of subsets of patients for further intervention, and predischarge assessment to predict the future course of patients after an acute myocardial infarction.

  12. EANM procedural guidelines for radionuclide myocardial perfusion imaging with SPECT and SPECT/CT: 2015 revision.

    PubMed

    Verberne, Hein J; Acampa, Wanda; Anagnostopoulos, Constantinos; Ballinger, Jim; Bengel, Frank; De Bondt, Pieter; Buechel, Ronny R; Cuocolo, Alberto; van Eck-Smit, Berthe L F; Flotats, Albert; Hacker, Marcus; Hindorf, Cecilia; Kaufmann, Philip A; Lindner, Oliver; Ljungberg, Michael; Lonsdale, Markus; Manrique, Alain; Minarik, David; Scholte, Arthur J H A; Slart, Riemer H J A; Trägårdh, Elin; de Wit, Tim C; Hesse, Birger

    2015-11-01

    Since the publication of the European Association of Nuclear Medicine (EANM) procedural guidelines for radionuclide myocardial perfusion imaging (MPI) in 2005, many small and some larger steps of progress have been made, improving MPI procedures. In this paper, the major changes from the updated 2015 procedural guidelines are highlighted, focusing on the important changes related to new instrumentation with improved image information and the possibility to reduce radiation exposure, which is further discussed in relation to the recent developments of new International Commission on Radiological Protection (ICRP) models. Introduction of the selective coronary vasodilator regadenoson and the use of coronary CT-contrast agents for hybrid imaging with SPECT/CT angiography are other important areas for nuclear cardiology that were not included in the previous guidelines. A large number of minor changes have been described in more detail in the fully revised version available at the EANM home page: http://eanm.org/publications/guidelines/2015_07_EANM_FINAL_myocardial_perfusion_guideline.pdf .

  13. EANM procedural guidelines for radionuclide myocardial perfusion imaging with SPECT and SPECT/CT: 2015 revision.

    PubMed

    Verberne, Hein J; Acampa, Wanda; Anagnostopoulos, Constantinos; Ballinger, Jim; Bengel, Frank; De Bondt, Pieter; Buechel, Ronny R; Cuocolo, Alberto; van Eck-Smit, Berthe L F; Flotats, Albert; Hacker, Marcus; Hindorf, Cecilia; Kaufmann, Philip A; Lindner, Oliver; Ljungberg, Michael; Lonsdale, Markus; Manrique, Alain; Minarik, David; Scholte, Arthur J H A; Slart, Riemer H J A; Trägårdh, Elin; de Wit, Tim C; Hesse, Birger

    2015-11-01

    Since the publication of the European Association of Nuclear Medicine (EANM) procedural guidelines for radionuclide myocardial perfusion imaging (MPI) in 2005, many small and some larger steps of progress have been made, improving MPI procedures. In this paper, the major changes from the updated 2015 procedural guidelines are highlighted, focusing on the important changes related to new instrumentation with improved image information and the possibility to reduce radiation exposure, which is further discussed in relation to the recent developments of new International Commission on Radiological Protection (ICRP) models. Introduction of the selective coronary vasodilator regadenoson and the use of coronary CT-contrast agents for hybrid imaging with SPECT/CT angiography are other important areas for nuclear cardiology that were not included in the previous guidelines. A large number of minor changes have been described in more detail in the fully revised version available at the EANM home page: http://eanm.org/publications/guidelines/2015_07_EANM_FINAL_myocardial_perfusion_guideline.pdf . PMID:26290421

  14. Automatic detection of CT perfusion datasets unsuitable for analysis due to head movement of acute ischemic stroke patients.

    PubMed

    Fahmi, Fahmi; Marquering, Henk A; Streekstra, Geert J; Beenen, Ludo F M; Janssen, Natasja N Y; Majoie, Charles B L; van Bavel, Ed

    2014-01-01

    Head movement during brain Computed Tomography Perfusion (CTP) can deteriorate perfusion analysis quality in acute ischemic stroke patients. We developed a method for automatic detection of CTP datasets with excessive head movement, based on 3D image-registration of CTP, with non-contrast CT providing transformation parameters. For parameter values exceeding predefined thresholds, the dataset was classified as 'severely moved'. Threshold values were determined by digital CTP phantom experiments. The automated selection was compared to manual screening by 2 experienced radiologists for 114 brain CTP datasets. Based on receiver operator characteristics, optimal thresholds were found of respectively 1.0°, 2.8° and 6.9° for pitch, roll and yaw, and 2.8 mm for z-axis translation. The proposed method had a sensitivity of 91.4% and a specificity of 82.3%. This method allows accurate automated detection of brain CTP datasets that are unsuitable for perfusion analysis. PMID:24691387

  15. Evidence-based guideline: The role of diffusion and perfusion MRI for the diagnosis of acute ischemic stroke

    PubMed Central

    Schellinger, P.D.; Bryan, R.N.; Caplan, L.R.; Detre, J.A.; Edelman, R.R.; Jaigobin, C.; Kidwell, C.S.; Mohr, J.P.; Sloan, M.; Sorensen, A.G.; Warach, S.

    2010-01-01

    Objective: To assess the evidence for the use of diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) in the diagnosis of patients with acute ischemic stroke. Methods: We systematically analyzed the literature from 1966 to January 2008 to address the diagnostic and prognostic value of DWI and PWI. Results and Recommendations: DWI is established as useful and should be considered more useful than noncontrast CT for the diagnosis of acute ischemic stroke within 12 hours of symptom onset. DWI should be performed for the most accurate diagnosis of acute ischemic stroke (Level A); however, the sensitivity of DWI for the diagnosis of ischemic stroke in a general sample of patients with possible acute stroke is not perfect. The diagnostic accuracy of DWI in evaluating cerebral hemorrhage is outside the scope of this guideline. On the basis of Class II and III evidence, baseline DWI volumes probably predict baseline stroke severity in anterior territory stroke (Level B) but possibly do not in vertebrobasilar artery territory stroke (Level C). Baseline DWI lesion volumes probably predict (final) infarct volumes (Level B) and possibly predict early and late clinical outcome measures (Level C). Baseline PWI volumes predict to a lesser degree the baseline stroke severity compared with DWI (Level C). There is insufficient evidence to support or refute the value of PWI in diagnosing acute ischemic stroke (Level U). GLOSSARY ADC = apparent diffusion coefficient; ASPECTS = Alberta Stroke Program Early CT Score; CBF = cerebral blood flow; CI = confidence interval; DWI = diffusion-weighted imaging; ICH = intracerebral hemorrhage; MR = magnetic resonance; NIHSS = National Institute of Health Stroke Scale; PWI = perfusion-weighted imaging; tPA = tissue plasminogen activator. PMID:20625171

  16. Defining Core and Penumbra in Ischemic Stroke: A Voxel- and Volume-Based Analysis of Whole Brain CT Perfusion

    PubMed Central

    Yu, Yannan; Han, Quan; Ding, Xinfa; Chen, Qingmeng; Ye, Keqi; Zhang, Sheng; Yan, Shenqiang; Campbell, Bruce C. V.; Parsons, Mark W.; Wang, Shaoshi; Lou, Min

    2016-01-01

    Whole brain computed tomography perfusion (CTP) has the potential to select eligible patients for reperfusion therapy. We aimed to find the optimal thresholds on baseline CTP for ischemic core and penumbra in acute ischemic stroke. We reviewed patients with acute ischemic stroke in the anterior circulation, who underwent baseline whole brain CTP, followed by intravenous thrombolysis and perfusion imaging at 24 hours. Patients were divided into those with major reperfusion (to define the ischemic core) and minimal reperfusion (to define the extent of penumbra). Receiver operating characteristic (ROC) analysis and volumetric consistency analysis were performed separately to determine the optimal threshold by Youden’s Index and mean magnitude of volume difference, respectively. From a series of 103 patients, 22 patients with minimal-reperfusion and 47 with major reperfusion were included. Analysis revealed delay time ≥ 3 s most accurately defined penumbra (AUC = 0.813; 95% CI, 0.812-0.814, mean magnitude of volume difference = 29.1 ml). The optimal threshold for ischemic core was rCBF ≤ 30% within delay time ≥ 3 s (AUC = 0.758; 95% CI, 0.757-0.760, mean magnitude of volume difference = 10.8 ml). In conclusion, delay time ≥ 3 s and rCBF ≤ 30% within delay time ≥ 3 s are the optimal thresholds for penumbra and core, respectively. These results may allow the application of the mismatch on CTP to reperfusion therapy. PMID:26860196

  17. Alterations in left ventricular diastolic function in chronic ischemic heart failure. Assessment by radionuclide angiography.

    PubMed

    Bareiss, P; Facello, A; Constantinesco, A; Demangeat, J L; Brunot, B; Arbogast, R; Roul, G

    1990-02-01

    Using radionuclide angiography at rest, we studied several parameters of left ventricular systolic and diastolic function in 60 patients divided into three groups, a control group (G1) of 15 patients and two groups of patients with chronic ischemic heart disease and previous anterior wall myocardial infarction but without aneurysm or dyskinetic wall motion, a second group (G2) of 23 patients with no history of heart failure, and a third group (G3) of 22 patients in New York Heart Association (NYHA) class II or III of heart failure. Ejection fraction, peak emptying, and peak filling rates, in addition to times to reach peak rates, were evaluated after constructing a global time-activity curve and its first time derivative. In addition, we computed the first time-derivative curves for each image pixel and obtained functional images (MIN/MAX images) representing the distribution of times to peak emptying or filling rates Using a left ventricular region of interest, time histograms were generated, and indexes of dispersion of times to peak rates, defined as the full width at half maximum of the histograms, were obtained. Significant (p less than or equal to 0.01) differences were observed among all groups for ejection fraction, peak emptying rate, and peak filling rate. The decrease of the peak filling rate still remained significant from group G1 to group G3 even after adjustment for differences in ejection fraction and heart rate. Peak filling rate was linearly correlated with ejection fraction in the population with ischemic heart disease (G2 + G3) (r = 0.68, p less than or equal to 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2297884

  18. Ischemic postconditioning influences electron transport chain protein turnover in Langendorff-perfused rat hearts

    PubMed Central

    Cao, Song; Liu, Yun; Wang, Haiying; Mao, Xiaowen; Chen, Jincong; Liu, Jiming; Xia, Zhengyuan; Zhang, Lin; Liu, Xingkui

    2016-01-01

    Ischemia postconditioning (IPo) is a promising strategy in reducing myocardial ischemia reperfusion (I/R) injury (MIRI), but its specific molecular mechanism is incompletely understood. Langendorff-perfused isolated rat hearts were subjected to global I/R and received IPo in the absence or presence of the mitochondrial ATP-sensitive potassium channel (mitoKATP) blocker 5-hydroxydecanoate (5-HD). Myocardial mitochondria were extracted and mitochondrial comparative proteomics was analyzed. IPo significantly reduces post-ischemic myocardial infarction and improved cardiac function in I/R rat hearts, while 5-HD basically cancelled IPo’s myocardial protective effect. Joint application of two-dimensional polyacrylamide gel electrophoresis (2DE) and MALDI-TOF MS identified eight differentially expressed proteins between groups. Expression of cardiac succinate dehydrogenase (ubiquinone) flavoprotein subunit (SDHA) increased more than two-fold after I/R, while IPo led to overexpression of dihydrolipoyl dehydrogenase (DLD), NADH dehydrogenase (ubiquinone) flavoprotein 1 and isoform CRA_b (NDUFV1). When the mitoKATP was blocked, MICOS complex subunit Mic60 (IMMT) and Stress-70 protein (Grp75) were over expressed, while DLDH, ATPase subunit A (ATPA) and rCG44606 were decreased. Seven of the differential proteins belong to electron transport chain (ETC) or metabolism regulating proteins, and five of them were induced by closing mitoKATP in I/R hearts. We thus conclude that IPo’s myocardial protective effect relies on energy homeostasis regulation. DLD, SDHA, NDUFV1, Grp75, ATPA and rCG44606 may contribute to IPo’s cardial protective effect. PMID:26925330

  19. Ischemic preconditioning increases muscle perfusion, oxygen uptake, and force in strength-trained athletes.

    PubMed

    Paradis-Deschênes, Pénélope; Joanisse, Denis R; Billaut, François

    2016-09-01

    Muscle ischemia and reperfusion induced by ischemic preconditioning (IPC) can improve performance in various activities. However, the underlying mechanisms are still poorly understood. The purpose of this study was to examine the effects of IPC on muscle hemodynamics and oxygen (O2) uptake during repeated maximal contractions. In a cross-over, randomized, single-blind study, 10 strength-trained men performed 5 sets of 5 maximal voluntary knee extensions of the right leg on an isokinetic dynamometer, preceded by either IPC of the right lower limb (3×5-min compression/5-min reperfusion cycles at 200 mm Hg) or sham (20 mm Hg). Changes in deoxyhemoglobin, expressed as a percentage of arterial occlusion, and total hemoglobin ([THb]) concentrations of the vastus lateralis muscle were monitored continuously by near-infrared spectroscopy. Differences between IPC and sham were analyzed using Cohen's effect size (ES) ± 90% confidence limits, and magnitude-based inferences. Compared with sham, IPC likely increased muscle blood volume at rest (↑[THb], 46.5%; ES, 0.56; 90% confidence limits for ES, -0.21, 1.32). During exercise, peak force was almost certainly higher (11.8%; ES, 0.37; 0.27, 0.47), average force was very likely higher (12.6%; ES, 0.47; 0.29, 0.66), and average muscle O2 uptake was possibly increased (15.8%; ES, 0.36; -0.07, 0.79) after IPC. In the recovery periods between contractions, IPC also increased blood volume after sets 1 (23.6%; ES, 0.30; -0.05, 0.65) and 5 (25.1%; ES, 0.32; 0.09, 0.55). Three cycles of IPC immediately increased muscle perfusion and O2 uptake, conducive to higher repeated force capacity in strength-trained athletes. This maneuver therefore appears relevant to enhancing exercise training stimulus. PMID:27574913

  20. Renal perfusion scintiscan

    MedlinePlus

    Renal perfusion scintigraphy; Radionuclide renal perfusion scan; Perfusion scintiscan - renal; Scintiscan - renal perfusion ... supply the kidneys. This is a condition called renal artery stenosis. Significant renal artery stenosis may be ...

  1. [Use of SPECT-scanning of the heart in estimating of influence of drugs of the background therapy of ischemic heart disease on myocardial perfusion].

    PubMed

    Svistov, A S; Sukhov, V Iu; Makiev, R G; Alanichev, A E

    2012-10-01

    Some new facts about the influence of different groups of drugs on myocardial perfusion were educed during the research. Educed facts conduce representation extension by matching the optimal therapy of ischemic heart disease. With the help of SPECT-scanning were educed myocardial blood flow, areas of maximal hypoperfusion and its influence on time pattern and redistribution of myocardial blood flow in patients receiving disease-modifying agents and statins. Some regularities of change of myocardial blood flow depending on applied group of drugs and peculiarities of influence of myocardial perfusion in certain time interval were revealed. Criteria with prognostic significance in prospective individual effectiveness of anti-ischemic drugs were pointed out. New approach, based on choice of anti-ischemic therapy depending on extent of influence on myocardial perfusion and also individual clinical and functional traits of patients, was applied. PMID:23213770

  2. Clinical usefulness of combined radionuclide venography (RNV) and pulmonary perfusion scanning in thromboembolic disease

    SciTech Connect

    Dibos, P.E.; Park, B.J.; Luger, R.C.

    1985-05-01

    Radionuclide venography of the lower extremities and the pelvis (RNV) was performed in 1,089 patients with suspected deep venous thrombosis (INT) during the period February 1978 to December 1984. Sequential images of the calves, knees, thighs and pelvis were obtained immediately after injection of 2 mCi of Tc-99m MAA into a vein of the dorsum of each foot while tourniquets were applied above the ankles. Views of the same regions were obtained after releasing of the tourniquets. Six view pulmonary perfusion scanning (PPS) was performed routinely upon completion of RNV. Xe-133 pulmonary ventilation scans (PVS) were done just prior to RNV in patients suspected of having pulmonary embolism. Conventional radiographic venography (XRV) was obtained in 57 of the 1,089 patients; in most of these cases, XRV was carried out within 48 hours of RVV. Results of RNV and XRV were in agreement in 88% of the cases and conflicted in 12% of the 57 cases. DVT was diagnosed by RNV and XRV in 21 of the 57 patients who had both studies. RNV and XRV were normal in 29 of the 57 patients and conflicting results were obtained in 7 patients. There were 5 false-positive RNV (8.7%) and 2 false-negative RNV (3.5%) considering the XRV as the definitive study. Out of 260 patients scanned during 1984, 26 (10%) patients had RNV/PPS findings positive for DVT and pulmonary embolism (PE); in most of these cases (22) PE was clinically unsuspected. The authors conclude that RNV is a simple, safe, clinically useful technique in the evaluation of patients with suspected DVT. PPS should follow RNV routinely. The incidence of unsuspected PE in patients with DVT is high.

  3. Application of hidden Markov random field approach for quantification of perfusion/diffusion mismatch in acute ischemic stroke.

    PubMed

    Dwyer, Michael G; Bergsland, Niels; Saluste, Erik; Sharma, Jitendra; Jaisani, Zeenat; Durfee, Jacqueline; Abdelrahman, Nadir; Minagar, Alireza; Hoque, Romy; Munschauer, Frederick E; Zivadinov, Robert

    2008-10-01

    The perfusion/diffusion 'mismatch model' in acute ischemic stroke provides the potential to more accurately understand the consequences of thrombolytic therapy on an individual patient basis. Few methods exist to quantify mismatch extent (ischemic penumbra) and none have shown a robust ability to predict infarcted tissue outcome. Hidden Markov random field (HMRF) approaches have been used successfully in many other applications. The aim of the study was to develop a method for rapid and reliable identification and quantification of perfusion/diffusion mismatch using an HMRF approach. An HMRF model was used in combination with automated contralateral identification to segment normal tissue from non-infarcted tissue with perfusion abnormality. The infarct was used as a seed point to initialize segmentation, along with the contralateral mirror tissue. The two seeds were then allowed to compete for ownership of all unclassified tissue. In addition, a novel method was presented for quantifying tissue salvageability by weighting the volume with the degree of hypoperfusion, allowing the penumbra voxels to contribute unequal potential damage estimates. Simulated and in vivo datasets were processed and compared with results from a conventional thresholding approach. Both simulated and in vivo experiments demonstrated a dramatic improvement in accuracy with the proposed technique. For the simulated dataset, the mean absolute error decreased from 171.9% with conventional thresholding to 2.9% for the delay-weighted HMRF approach. For the in vivo dataset, the mean absolute error decreased from 564.6% for thresholding to 34.2% for the delay-weighted HMRF approach. The described method represents a significant improvement over thresholding techniques.

  4. Comparative value of maximal treadmill testing, exercise thallium myocardial perfusion scintigraphy and exercise radionuclide ventriculography for distinguishing high- and low-risk patients soon after acute myocardial infarction

    SciTech Connect

    Hung, J.; Goris, M.L.; Nash, E.; Kraemer, H.C.; DeBusk, R.F.; Berger, W.E.; Lew, H.

    1984-05-01

    The prognostic value of symptom-limited treadmill exercise electrocardiography, exercise thallium myocardial perfusion scintigraphy and rest and exercise radionuclide ventriculography was compared in 117 men, aged 54 +/- 9 years, tested 3 weeks after a clinically uncomplicated acute myocardial infarction (MI). During a mean follow-up period of 11.6 months, 8 men experienced ''hard'' medical events (cardiac death, nonfatal ventricular fibrillation or recurrent MI) and 14 were hospitalized for unstable angina pectoris, congestive heart failure or coronary bypass surgery (total of 22 combined events). By multivariate analysis (Cox proportional hazards model), peak treadmill work load and the change in left ventricular ejection fraction (EF) during exercise were significant (p less than 0.01) predictors of hard medical events; these 2 risk factors and recurrent ischemic chest pain in the coronary care unit were also significantly predictive (p less than 0.001) for combined events. A peak treadmill work load of 4 METs or less or a decrease in EF of 5% or more below the value at rest during submaximal effort distinguished 22 high-risk patients (20% of the study population) from 89 low-risk patients. The rate of hard medical events within 12 months was 23% (5 of 22 patients), vs 2% (2 of 89 patients) in the high- and low-risk patient subsets, respectively (p less than 0.001). Thus, in patients who underwent evaluation 3 weeks after a clinically uncomplicated MI, exercise radionuclide ventriculography contributed independent prognostic information to that provided by symptom-limited treadmill testing and was superior to exercise thallium scintigraphy for this purpose.

  5. Optical bedside monitoring of cerebral perfusion: technological and methodological advances applied in a study on acute ischemic stroke

    NASA Astrophysics Data System (ADS)

    Steinkellner, Oliver; Gruber, Clemens; Wabnitz, Heidrun; Jelzow, Alexander; Steinbrink, Jens; Fiebach, Jochen B.; MacDonald, Rainer; Obrig, Hellmuth

    2010-11-01

    We present results of a clinical study on bedside perfusion monitoring of the human brain by optical bolus tracking. We measure the kinetics of the contrast agent indocyanine green using time-domain near-IR spectroscopy (tdNIRS) in 10 patients suffering from acute unilateral ischemic stroke. In all patients, a delay of the bolus over the affected when compared to the unaffected hemisphere is found (mean: 1.5 s, range: 0.2 s to 5.2 s). A portable time-domain near-IR reflectometer is optimized and approved for clinical studies. Data analysis based on statistical moments of time-of-flight distributions of diffusely reflected photons enables high sensitivity to intracerebral changes in bolus kinetics. Since the second centralized moment, variance, is preferentially sensitive to deep absorption changes, it provides a suitable representation of the cerebral signals relevant for perfusion monitoring in stroke. We show that variance-based bolus tracking is also less susceptible to motion artifacts, which often occur in severely affected patients. We present data that clearly manifest the applicability of the tdNIRS approach to assess cerebral perfusion in acute stroke patients at the bedside. This may be of high relevance to its introduction as a monitoring tool on stroke units.

  6. Assessment of single vessel coronary artery disease: results of exercise electrocardiography, thallium-201 myocardial perfusion imaging and radionuclide angiography

    SciTech Connect

    Port, S.C.; Oshima, M.; Ray, G.; McNamee, P.; Schmidt, D.H.

    1985-07-01

    The sensitivity of the commonly used stress tests for the diagnosis of coronary artery disease was analyzed in 46 patients with significant occlusion (greater than or equal to 70% luminal diameter obstruction) of only one major coronary artery and no prior myocardial infarction. In all patients, thallium-201 perfusion imaging (both planar and seven-pinhole tomographic) and 12 lead electrocardiography were performed during the same graded treadmill exercise test and radionuclide angiography was performed during upright bicycle exercise. Exercise rate-pressure (double) product was 22,307 +/- 6,750 on the treadmill compared with 22,995 +/- 5,622 on the bicycle (p = NS). Exercise electrocardiograms were unequivocally abnormal in 24 patients (52%). Qualitative planar thallium images were abnormal in 42 patients (91%). Quantitative analysis of the tomographic thallium images were abnormal in 41 patients (89%). An exercise ejection fraction of less than 0.56 or a new wall motion abnormality was seen in 30 patients (65%). Results were similar for the right (n = 11) and left anterior descending (n = 28) coronary arteries while all tests but the planar thallium imaging showed a lower sensitivity for isolated circumflex artery disease (n = 7). The specificity of the tests was 72, 83, 89 and 72% for electrocardiography, planar thallium imaging, tomographic thallium imaging and radionuclide angiography, respectively. The results suggest that exercise thallium-201 perfusion imaging is the most sensitive noninvasive stress test for the diagnosis of single vessel coronary artery disease.

  7. Osmotic drug delivery to ischemic hindlimbs and perfusion of vasculature with microfil for micro-computed tomography imaging.

    PubMed

    Liu, Xiaobing; Terry, Toya; Pan, Su; Yang, Zhongwei; Willerson, James T; Dixon, Richard A F; Liu, Qi

    2013-06-29

    Preclinical research in animal models of peripheral arterial disease plays a vital role in testing the efficacy of therapeutic agents designed to stimulate microcirculation. The choice of delivery method for these agents is important because the route of administration profoundly affects the bioactivity and efficacy of these agents(1,2). In this article, we demonstrate how to locally administer a substance in ischemic hindlimbs by using a catheterized osmotic pump. This pump can deliver a fixed volume of aqueous solution continuously for an allotted period of time. We also present our mouse model of unilateral hindlimb ischemia induced by ligation of the common femoral artery proximal to the origin of profunda femoris and epigastrica arteries in the left hindlimb. Lastly, we describe the in vivo cannulation and ligation of the infrarenal abdominal aorta and perfusion of the hindlimb vasculature with Microfil, a silicone radiopaque casting agent. Microfil can perfuse and fill the entire vascular bed (arterial and venous), and because we have ligated the major vascular conduit for exit, the agent can be retained in the vasculature for future ex vivo imaging with the use of small specimen micro-CT(3).

  8. Computed tomography perfusion imaging may predict cognitive impairment in patients with first-time anterior circulation transient ischemic attack.

    PubMed

    Wang, Jun; Li, Yunming; Zheng, Bo; Wang, Jian; Wang, Zhiqiang; Duan, Dan; Li, Yuxia; Wang, Qingsong

    2016-04-01

    To determine whether computed tomography perfusion imaging (CTPI)-derived parameters are associated with vascular cognitive impairment (VCI) in patients with transient ischemic attack (TIA). Patients with first-time anterior circulation TIA (diagnosed within 24 h of onset) and normal cognition, treated between August 2009 and August 2014 at the Department of Neurology of Chengdu Military General Hospital, China, were analyzed retrospectively. Patients underwent whole-brain CTPI within 1 week of TIA to detect cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT) and time to peak (TTP) in the ischemic region. Based on cognitive function assessment 4 weeks after TIA, using the Montreal cognitive assessment (MoCA) and mini mental state examination, the patients were divided into control and VCI groups. CTPI parameters and other clinical data were compared between groups, and Spearman's correlation analysis used to identify associations between cognitive scores and CTPI parameters in the VCI group. 50 patients (25 per group; aged 55-72 years) were included. Patient age, gender, smoking status, alcohol consumption, educational level, time from TIA onset to admission, time from TIA onset to CTPI, and prevalence of hypertension, diabetes mellitus, hyperlipidemia, atrial fibrillation and hyperhomocysteinemia did not differ between groups. Both groups showed TTP and MTT prolongation, CBF reduction, but no change in CBV in the ischemic region; these changes were significantly larger in the VCI group (P < 0.05). MTT correlated negatively with MoCA score (r = -0.51, P = 0.009). CTPI could facilitate early diagnosis of VCI in patients with anterior circulation TIA.

  9. Attempt to rescue discarded human liver grafts by end ischemic hypothermic oxygenated machine perfusion.

    PubMed

    Vekemans, K; van Pelt, J; Komuta, M; Wylin, T; Heedfeld, V; Detry, O; Monbaliu, D; Pirenne, J

    2011-11-01

    In a porcine liver transplant model, a brief period of oxygenated hypothermic machine perfusion (HMP) at the end of simple cold storage (SCS) has been shown to improve the viability of damaged liver grafts. To test the clinical validity of this strategy, we randomized SCS-discarded human liver grafts to either 4 hours of HMP (n = 13) or an additional 4 hours of SCS (n = 14). All livers were then warm reperfused to mimic ischemia-reperfusion injury ex vivo. The settings for HMP were: portal vein: 3 mm Hg, 300 mL/min and hepatic artery: 20 mm Hg, pO(2): 300 mm Hg. Perfusion used Kidney Machine Perfusion Solution at 4°C to 8°C. During warm reperfusion, aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) values were higher (P < .015) among the SCS versus HMP methods at all times. The AST slope was lower in HMP versus SCS (P = .01). The LDH slope tended to be lower for HMP versus SCS (P = .07). Morphological scores were not different between HMP and SCS. At the start of warm reperfusion, MAPK was lower in HMP versus SCS (P = .02). Endothelin-1 (EDN1) and ICAM-1 tended to be lower in HMP versus SCS (P = .1 and .07, respectively). No difference was noted in MAPK, EDN1, and ICAM-1 after 60 or 120 minutes of warm reperfusion. In conclusion, HMP down-regulated MAPK and tended to reduce EDN1 and ICAM-1 mRNA in human liver grafts. During warm reperfusion, HMP versus SCS livers showed reduced AST and LDH release but no morphological difference. Further optimization of liver HMP may require different timing/duration of perfusion and/or an higher perfusion temperature.

  10. A mismatch between the abnormalities in diffusion- and susceptibility-weighted magnetic resonance imaging may represent an acute ischemic penumbra with misery perfusion.

    PubMed

    Fujioka, Masayuki; Okuchi, Kazuo; Iwamura, Asami; Taoka, Toshiaki; Siesjö, Bo K

    2013-11-01

    Susceptibility-weighted imaging (SWI) has recently attracted attention for its ability to investigate acute stroke pathophysiology. SWI detects an increased ratio of deoxyhemoglobin to oxyhemoglobin in cerebral venous compartments, which can illustrate cerebral misery perfusion with a compensatory increase of oxygen extraction fraction in the hypoperfused brain. In this study we make the first case report of blunt cervical trauma leading to a stroke, demonstrating the disparity between diffusion-weighted imaging (DWI) and SWI changes, or DWI-SWI mismatch, in the acute ischemic brain. The area of mismatch between a smaller DWI cytotoxic edema and a larger SWI misery perfusion in our patient matured into a complete infarction with time. The DWI-SWI mismatch may signify the presence of an ischemic penumbra, and provide information about viability of the brain tissue at risk of potential infarction if without early reperfusion.

  11. Pharmacological and other nonexercise alternatives to exercise testing to evaluate myocardial perfusion and left ventricular function with radionuclides

    SciTech Connect

    DePuey, E.G.; Rozanski, A. )

    1991-04-01

    Pharmacological vasodilatation with either dipyridamole or adenosine is a safe and accurate alternative to exercise testing to diagnose coronary artery disease with thallium 201 myocardial perfusion imaging. The technique also provides important prognostic information with regard to future cardiac events in patients undergoing diagnostic testing, in those evaluated preoperatively, and in those with recent myocardial infarctions. Multigated equilibrium and first-pass radionuclide ventriculography also are well suited to evaluate the effects of interventional procedures. Success has been achieved using this methodology in a variety of interventions including conventional exercise testing, pharmacological stress testing, atrial pacing, assessment of myocardial viability with nitroglycerin, mental stress testing, and ambulatory monitoring of left ventricular ejection fraction. 67 references.

  12. Mismatch of Low Perfusion and High Permeability Predicts Hemorrhagic Transformation Region in Acute Ischemic Stroke Patients Treated with Intra-arterial Thrombolysis

    PubMed Central

    Chen, Hui; Liu, Nan; Li, Ying; Wintermark, Max; Jackson, Alan; Wu, Bing; Su, Zihua; Chen, Fei; Hu, Jun; Zhang, Yongwei; Zhu, Guangming

    2016-01-01

    This study sought to determine whether the permeability related parameter Ktrans, derived from computed tomography perfusion (CTP) imaging, can predict hemorrhagic transformation (HT) in patients with acute ischemic stroke who receive intra-arterial thrombolysis. Data from patients meeting the criterion were examined. CTP was performed and Ktrans maps were used to assess the permeability values in HT and non-HT regions. A receiver operating characteristic (ROC) curve was calculated, showing the sensitivity and specificity of Ktrans for predicting HT risk. Composite images were produced to illustrate the spatial correlations among perfusion, permeability changes and HT. This study examined 41 patients. Twenty-six patients had hemorrhagic infarction and 15 had parenchymal hemorrhage. The mean Ktrans value in HT regions was significantly lower than that in the non-HT regions (0.26 ± 0.21/min vs. 0.78 ± 0.64/min; P < 0.001). The ROC curve analysis identified an optimal cutoff value of 0.334/min for Ktrans to predict HT risk. Composite images suggested ischemic regions with low permeability, or the mismatch area of low perfusion and high permeability, more likely have HT. HT regions after intra-arterial thrombolysis had lower permeability values on Ktrans maps. The mismatch area of lower perfusion and higher permeability are more likely to develop HT. PMID:27302077

  13. External quantification of myocardial perfusion by exponential infusion of positron-emitting radionuclides.

    PubMed

    Hack, S N; Eichling, J O; Bergmann, S R; Welch, M J; Sobel, B E

    1980-11-01

    A technique was developed and evaluated using the exponential infusion of positron-emitting diffusible tracers to quantitate myocardial perfusion. The approach employs a parameter that rapidly reaches a constant value as a function of tracer delivery rate, isotope decay constant, and the monotonically increasing tissue radioactivity. Isolated rabbit hearts with controlled flow were used to evaluate the approach, because tracer kinetics in such preparations mimic those in vivo. Accordingly, exponential infusions of H2 15O and [11C]butanol were administered to 25 isolated rabbit hearts perfused with Krebs-Henseleit solution (KH) alone or KH enriched with erythrocytes (KH-RBC, hematocrit = 40). With flow varied from 1.2 to 5 ml/g per min in eight KH hearts infused with H2 15O, actual and estimated flow correlated closely (r = 0.95, n = 52 determinations). For the KH-RBC hearts, flow was varied from 0.3 to 1.5 ml/g per min. Actual and estimated flow correlated significantly for both the 14 KH-RBC hearts infused with H2 15O (r = 0.90, n = 89 determinations) and the 3 KH-RBC hearts infused with [11C]butanol (r = 0.93, n = 13 determinations). In addition, the required exponentially increasing arterial tracer concentrations were shown to be attainable in vivo in dogs and rhesus monkeys after intravenous exponential administrations of tracer. The results suggest that the approach developed employing exponential tracer infusion permits accurate measurement of myocardial perfusion and that it should prove useful in the noninvasive measurement of regional myocardial perfusion in vivo by positron emission tomography.

  14. Reversibility of intrapulmonary arteriovenous shunts in liver cirrhosis documented by serial radionuclide perfusion lung scans

    SciTech Connect

    Chen, N.S.; Barnett, C.A.; Farrer, P.A.

    1984-05-01

    Using serial perfusion lung scans, the opening up and closure of right-to-left intrapulmonary arteriovenous shunts has been documented over a period of several weeks in a patient with chronic alcoholic liver disease. The presence of the shunts correlates well with the severity of hypoxemia and the presence of nodular mottling on chest radiographs. The time course of these changes with clinical status suggests lability and the functional nature of these shunts.

  15. Multimodal CT techniques for cerebrovascular and hemodynamic evaluation of ischemic stroke: occlusion, collaterals, and perfusion.

    PubMed

    Jia, Baixue; Scalzo, Fabien; Agbayani, Elijah; Woolf, Graham W; Liu, Liping; Miao, Zhongrong; Liebeskind, David S

    2016-05-01

    Neuroimaging of cerebrovascular status and hemodynamics has vastly improved our understanding of stroke mechanisms and provided information for therapeutic decision-making. CT techniques are the most commonly used techniques due to wide availability, rapid acquisition and acceptable tolerance. Numerous multimodal CT techniques have been developed in the last few years. We summarize and explain the various multimodal CT acquisition techniques within three categories based on the scanning mode, namely static mode (single-phase CTA), multiple static mode (multi-phase CTA) and continuous mode (CT perfusion and dynamic CTA). Post-processing methods based on different acquisition modes are also introduced in an easy manner by focusing on the information extracted and products generated. We also describe the applications for these techniques along with their advantages and disadvantages. PMID:26967556

  16. Is there more valuable information in PWI datasets for a voxel-wise acute ischemic stroke tissue outcome prediction than what is represented by typical perfusion maps?

    NASA Astrophysics Data System (ADS)

    Forkert, Nils Daniel; Siemonsen, Susanne; Dalski, Michael; Verleger, Tobias; Kemmling, Andre; Fiehler, Jens

    2014-03-01

    The acute ischemic stroke is a leading cause for death and disability in the industry nations. In case of a present acute ischemic stroke, the prediction of the future tissue outcome is of high interest for the clinicians as it can be used to support therapy decision making. Within this context, it has already been shown that the voxel-wise multi-parametric tissue outcome prediction leads to more promising results compared to single channel perfusion map thresholding. Most previously published multi-parametric predictions employ information from perfusion maps derived from perfusion-weighted MRI together with other image sequences such as diffusion-weighted MRI. However, it remains unclear if the typically calculated perfusion maps used for this purpose really include all valuable information from the PWI dataset for an optimal tissue outcome prediction. To investigate this problem in more detail, two different methods to predict tissue outcome using a k-nearest-neighbor approach were developed in this work and evaluated based on 18 datasets of acute stroke patients with known tissue outcome. The first method integrates apparent diffusion coefficient and perfusion parameter (Tmax, MTT, CBV, CBF) information for the voxel-wise prediction, while the second method employs also apparent diffusion coefficient information but the complete perfusion information in terms of the voxel-wise residue functions instead of the perfusion parameter maps for the voxel-wise prediction. Overall, the comparison of the results of the two prediction methods for the 18 patients using a leave-one-out cross validation revealed no considerable differences. Quantitatively, the parameter-based prediction of tissue outcome led to a mean Dice coefficient of 0.474, while the prediction using the residue functions led to a mean Dice coefficient of 0.461. Thus, it may be concluded from the results of this study that the perfusion parameter maps typically derived from PWI datasets include all

  17. Effectiveness of skin perfusion pressure monitoring during surgery for an ischemic steal syndrome associated refractory ulcer.

    PubMed

    Okubo, Kentaro; Sato, Takashi; Matsubara, Chieko; Tsuboi, Masato; Ishii, Yasuo; Tojimbara, Tamotsu

    2015-01-01

    We describe an 80-year-old man with end-stage renal disease due to type 2 diabetes who had been maintained on hemodialysis for 9 years. He developed refractory ulcers from an abraded wound in the right hand of his access arm. The arteriovenous fistula (AVF) was located between the right brachial artery and the median antecubital vein draining into the cephalic vein and the deep veins close to the elbow. The blood flow of the right brachial artery measured by using Doppler ultrasonography was 920 ml/min. On the contrary, the radial and ulnar arteries were poorly palpable near the wrist, and ultrasonography could not be performed accurately because of a high degree of calcification. The skin perfusion pressure (SPP) of the first finger on the affected side decreased to 22 mmHg. However, the SPP improved to approximately 40 mmHg upon blocking an inflow into the deep vein. According to SPP data, only a communicating branch of the deep vein was ligated, and the AVF itself was preserved. One month after surgery, the skin ulcer healed, and maintenance hemodialysis was performed by using the preserved cephalic vein for blood access.In conclusion, we successfully treated a refractory wound associated with steal syndrome, without terminating the AVF. SPP-guided surgery may be safe and effective to adjust the blood flow in patients with AVF having steal syndrome.

  18. A Simple Geometric Assessment of Perfusion Lesion Volume at Hyperacute Stage of Ischemic Stroke in Patients with Symptomatic Steno-Occlusion of Major Cerebral Arteries and Risk of Subsequent Cerebral Ischemic Events.

    PubMed

    Kang, Jihoon; Jung, Cheolkyu; Kim, Nayoung; Son, Yoo Ri; Choi, Byungse; Kim, Jae-Hyoung; Lee, Ji Sung; Lee, Juneyoung; Lee, Jun; Jang, Myung Suk; Yang, Mi Hwa; Han, Moon-Ku; Bae, Hee-Joon

    2015-12-01

    Our objective is to elucidate the association of baseline perfusion lesion volume on perfusion-weighted magnetic resonance imaging (PWI) obtained at hyperacute stage of ischemic stroke with subsequent cerebral ischemic events (SIEs) in patients with symptomatic steno-occlusion of major cerebral arteries. Using a prospective stroke registry database, patients arriving within 24 hours of onset with symptomatic steno-occlusion of major supratentorial cerebral arteries were identified. On baseline PWI, time-to-peak lesion volume (TTP-LV) was determined by a simple geometric method and dichotomized into the highest tertile (large) and the other tertiles (small to medium) according to the vascular territory of occluded arteries. Primary outcome was a time to SIE up to 1 year after stroke onset. A total of 385 patients (a median time delay from onset to arrival, 2.2 hours) were enrolled. During the first year of stroke, the SIE rate of the large TTP-LV group was twice that of the small-to-medium TTP-LV group (35.7% versus 17.4%; P < .001). Large TTP-LV independently raised the hazard of SIE (hazard ratio, 2.24; 95% confidence interval, 1.45-3.44). This study demonstrates that TTP-LV on PWI measured through a simple geometric method at an emergency setting can be used to predict progression or recurrence of ischemic stroke in patients with symptomatic steno-occlusion of major cerebral arteries.

  19. Myocardial perfusion and contraction in acute ischemia and chronic ischemic heart disease.

    PubMed

    Canty, John M; Suzuki, Gen

    2012-04-01

    A large body of evidence has demonstrated that there is a close coupling between regional myocardial perfusion and contractile function. When ischemia is mild, this can result in the development of a new balance between supply and energy utilization that allows the heart to adapt for a period of hours over which myocardial viability can be maintained, a phenomenon known as "short-term hibernation". Upon reperfusion after reversible ischemia, regional myocardial function remains depressed. The "stunned myocardium" recovers spontaneously over a period of hours to days. The situation in myocardium subjected to chronic repetitive ischemia is more complex. Chronic dysfunction can initially reflect repetitive stunning with insufficient time for the heart to recover between episodes of spontaneous ischemia. As the frequency and/or severity of ischemia increases, the heart undergoes a series of adaptations which downregulate metabolism to maintain myocyte viability at the expense of contractile function. The resulting "hibernating myocardium" develops regional myocyte cellular hypertrophy as a compensatory response to ischemia-induced apoptosis along with a series of molecular adaptations that while regional, are similar to global changes found in advanced heart failure. As a result, flow-function relations become independently affected by tissue remodeling and interventions that stimulate myocyte regeneration. Similarly, chronic vascular remodeling may alter flow regulation in a fashion that increases myocardial vulnerability to ischemia. Here we review our current understanding of myocardial flow-function relations during acute ischemia in normal myocardium and highlight newly identified complexities in their interpretation in viable chronically dysfunctional myocardium with myocyte cellular and molecular remodeling. This article is part of a Special Issue entitled "Coronary Blood Flow".

  20. Successful outcome after endovascular thrombolysis for acute ischemic stroke with basis on perfusion-diffusion mismatch after 24 h of symptoms onset

    PubMed Central

    Mattei, Tobias A.; Rehman, Azeem A.; Goulart, Carlos R.; Sória, Marília G.; Rizelio, Vanessa; Meneses, Murilo S.

    2016-01-01

    Background: Although intravenous thrombolysis is the Food and Drug Administration-approved treatment for acute ischemic stroke (AIS) within 3 h, combined intravenous and intra-arterial thrombolysis with endovascular techniques may be able to extend this traditional time window. Case Description: We present the clinical evolution of a 45-year-old male presenting with acute left hemiparesis. Magnetic resonance imaging revealed a small diffusion restriction at the right basal ganglia with perfusion compromise in the entire right middle cerebral artery (MCA) territory. Angiography revealed a complete occlusion of MCA at its M1 segment. The patient underwent endovascular mechanical thrombectomy with additional intra-arterial thrombolysis more than 24 hours after the onset of the initial symptoms and experienced complete vessel recanalization. At 1 year, the patient had global independence with minor residual motor impairment in the left arm. Conclusions: We report the case of a successful thrombolytic therapy following AIS performed more than 24 h after the initial symptoms based on the presence of a perfusion-diffusion mismatch. This report is expected to stimulate the development of future prospective studies with special focus on the role of perfusion-diffusion mismatch in patient selection for treatment of AIS, especially in those presenting outside the traditional time window. PMID:27313971

  1. [Rest gated-SPECT myocardial perfusion post (99m)Tc-MIBI injection in a patient with acute chest pain and with no medical history of ischemic heart disease].

    PubMed

    Negre-Busó, M; Muntaner-Muñoz, L; Rubió-Rodríguez, A; Marin-Buriticá, A; Ferran-Sureda, N; Bassaganyas-Vilarrasa, J

    2015-01-01

    Gated-SPECT myocardial perfusion imaging is a widely used technique indicated for assessment of patients with no clear diagnosis of ischemic heart disease. Early rest gated-SPECT myocardial perfusion study in patients with acute chest pain has high sensitivity and high negative predictive value for ruling out coronary disease. We report a case of a patient admitted for the study of her chest pain. She underwent a myocardial perfusion stress-rest whose interpretation could have been equivocal due to the clinical status of the patient during the injection of the radiotracer. PMID:25759109

  2. Stress cardiac MR imaging: the role of stress functional assessment and perfusion imaging in the evaluation of ischemic heart disease.

    PubMed

    Al Sayari, Saeed; Kopp, Sebastien; Bremerich, Jens

    2015-03-01

    Stress cardiac magnetic resonance imaging can provide valuable information for the diagnosis and management of ischemic heart disease (IHD). It plays an important role in the initial diagnosis in patients with acute chest pain, in the diagnosis of complications post myocardial infarction (MI), in the assessment of the right ventricle after an acute MI, to detect complications due to or after interventions, in prediction of myocardial recovery, to detect inducible ischemia in patients with known IHD, in differentiating ischemic from non-ischemic dilated cardiomyopathy, and in risk stratification.

  3. Stress cardiac MR imaging: the role of stress functional assessment and perfusion imaging in the evaluation of ischemic heart disease.

    PubMed

    Al Sayari, Saeed; Kopp, Sebastien; Bremerich, Jens

    2015-03-01

    Stress cardiac magnetic resonance imaging can provide valuable information for the diagnosis and management of ischemic heart disease (IHD). It plays an important role in the initial diagnosis in patients with acute chest pain, in the diagnosis of complications post myocardial infarction (MI), in the assessment of the right ventricle after an acute MI, to detect complications due to or after interventions, in prediction of myocardial recovery, to detect inducible ischemia in patients with known IHD, in differentiating ischemic from non-ischemic dilated cardiomyopathy, and in risk stratification. PMID:25727000

  4. Simultaneous Tc-99m/I-123 dual-radionuclide myocardial perfusion/innervation imaging using Siemens IQ-SPECT with SMARTZOOM collimator

    NASA Astrophysics Data System (ADS)

    Du, Yong; Bhattacharya, Manojeet; Frey, Eric C.

    2014-06-01

    Simultaneous dual-radionuclide myocardial perfusion/innervation SPECT imaging can provide important information about the mismatch between scar tissue and denervated regions. The Siemens IQ-SPECT system developed for cardiac imaging uses a multifocal SMARTZOOM collimator to achieve a four-fold sensitivity for the cardiac region, compared to a typical parallel-hole low-energy high-resolution collimator, but without the data truncation that can result with conventional converging-beam collimators. The increased sensitivity allows shorter image acquisition times or reduced patient dose, making IQ-SPECT ideal for simultaneous dual-radionuclide SPECT, where reduced administrated activity is desirable in order to reduce patient radiation exposure. However, crosstalk is a major factor affecting the image quality in dual-radionuclide imaging. In this work we developed a model-based method that can estimate and compensate for the crosstalk in IQ-SPECT data. The crosstalk model takes into account interactions in the object and collimator-detector system. Scatter in the object was modeled using the effective source scatter estimation technique (ESSE), previously developed to model scatter with parallel-hole collimators. The geometric collimator-detector response was analytically modeled in the IQ-SPECT projector. The estimated crosstalk was then compensated for in an iterative reconstruction process. The new method was validated with data from both Monte Carlo simulations and physical phantom experiments. The results showed that the estimated crosstalk was in good agreement with simulated and measured results. After model-based compensation the images from simultaneous dual-radionuclide acquisitions were similar in quality to those from single-radionuclide acquisitions that did not have crosstalk contamination. The proposed model-based method can be used to improve simultaneous dual-radionuclide images acquired using IQ-SPECT. This work also demonstrates that ESSE scatter

  5. Coronary Computed Tomography Versus Radionuclide Myocardial Perfusion Imaging in Chest Pain Patients Admitted to Telemetry: A Randomized, Controlled Trial

    PubMed Central

    Levsky, Jeffrey M.; Spevack, Daniel M.; Travin, Mark I.; Menegus, Mark A.; Huang, Paul W.; Clark, Elana T.; Kim, Choo-won; Hirschhorn, Esther; Freeman, Katherine D.; Tobin, Jonathan N.; Haramati, Linda B.

    2016-01-01

    BACKGROUND Coronary computed tomography angiography plays an expanding role managing symptomatic patients with suspected coronary artery disease. Prospective intermediate-term outcomes are lacking. OBJECTIVE To compare coronary CT angiography with conventional non-invasive testing. DESIGN Randomized, controlled comparative effectiveness trial. SETTING Telemetry-monitored wards of one inner-city medical center. PATIENTS 400 acute chest pain patients (mean age 57); 63% women; 54% Hispanic, 37% African-American; low socioeconomic status. INTERVENTION Coronary CT angiography (CT) or radionuclide stress myocardial perfusion imaging (MPI). MEASUREMENTS The primary outcome was cardiac catheterization not leading to revascularization within one year. Secondary outcomes included length of stay, resource utilization and patient experience. Safety outcomes included death, major cardiovascular events and radiation exposure. RESULTS 30(15%) CT patients and 32(16%) MPI patients underwent cardiac catheterization within one year, of which 15(7.5%) and 20(10%), respectively, were not revascularized (-2.5% difference, 95%CI −8.6%–+3.5%; hazard ratio 0.77, 95%CI 0.40–1.49, p=0.44). Median length of stay was 28.9 hours for CT and 30.4 hours for MPI (p=0.057). Median follow-up was 40.4 months. For CT and MPI, the incidences of death (0.5% vs 3%, p=0.12), non-fatal cardiovascular events (4.5% vs 4.5%), re-hospitalization (43% vs 49%), emergency visit (63% vs 58%) and outpatient cardiology visit (23% vs 21%) were not different. Long-term, all-cause radiation was lower for CT (24 vs 29 milliSieverts, p<0.001). More CT patients graded their experience favorably (p=0.001) and would undergo the exam again (p=0.003). LIMITATIONS Single site study; primary outcome dependent on clinical management decisions. CONCLUSIONS There were no significant differences between CT and MPI in outcomes or resource utilization over 40 months. CT had lower associated radiation and was more positively

  6. SU-C-201-04: Quantification of Perfusion Heterogeneity Based On Texture Analysis for Fully Automatic Detection of Ischemic Deficits From Myocardial Perfusion Imaging

    SciTech Connect

    Fang, Y; Huang, H; Su, T

    2015-06-15

    Purpose: Texture-based quantification of image heterogeneity has been a popular topic for imaging studies in recent years. As previous studies mainly focus on oncological applications, we report our recent efforts of applying such techniques on cardiac perfusion imaging. A fully automated procedure has been developed to perform texture analysis for measuring the image heterogeneity. Clinical data were used to evaluate the preliminary performance of such methods. Methods: Myocardial perfusion images of Thallium-201 scans were collected from 293 patients with suspected coronary artery disease. Each subject underwent a Tl-201 scan and a percutaneous coronary intervention (PCI) within three months. The PCI Result was used as the gold standard of coronary ischemia of more than 70% stenosis. Each Tl-201 scan was spatially normalized to an image template for fully automatic segmentation of the LV. The segmented voxel intensities were then carried into the texture analysis with our open-source software Chang Gung Image Texture Analysis toolbox (CGITA). To evaluate the clinical performance of the image heterogeneity for detecting the coronary stenosis, receiver operating characteristic (ROC) analysis was used to compute the overall accuracy, sensitivity and specificity as well as the area under curve (AUC). Those indices were compared to those obtained from the commercially available semi-automatic software QPS. Results: With the fully automatic procedure to quantify heterogeneity from Tl-201 scans, we were able to achieve a good discrimination with good accuracy (74%), sensitivity (73%), specificity (77%) and AUC of 0.82. Such performance is similar to those obtained from the semi-automatic QPS software that gives a sensitivity of 71% and specificity of 77%. Conclusion: Based on fully automatic procedures of data processing, our preliminary data indicate that the image heterogeneity of myocardial perfusion imaging can provide useful information for automatic determination

  7. Beneficial Effect of Short Pretransplant Period of Hypothermic Pulsatile Perfusion of the Warm-Ischemic Kidney after Cold Storage: Experimental Study

    PubMed Central

    Humanes, Blanca; Jado, Juan Carlos; Mojena, Marina; González-Nicolás, María Ángeles; del Cañizo, Juan Francisco; Lledó-García, Enrique

    2016-01-01

    Warm ischemia (WI) produces a significant deleterious effect in potential kidney grafts. Hypothermic machine perfusion (HMP) seems to improve immediate graft function after transplant. Our aim was to analyze the effect of short pretransplant periods of pulsatile HMP on histology and renal injury in warm-ischemic kidneys. Twelve minipigs were used. WI was achieved in the right kidney by applying a vascular clamp for 45 min. After nephrectomy, autotransplant was performed following one of two strategies: cold storage of the kidneys or cold storage combined with perfusion in pulsatile HMP. The graft was removed early to study renal morphology, inflammation (fibrosis), and apoptosis. Proinflammatory activity and fibrosis were less pronounced after cold storage of the kidneys with HMP than after cold storage only. The use of HMP also decreased apoptosis compared with cold storage only. The detrimental effects on cells of an initial and prolonged period of WI seem to improve with a preservation protocol that includes a short period of pulsatile HMP after cold storage and immediately before the transplant, in comparison with cold storage only. PMID:27556029

  8. Interhemispheric Cerebral Blood Flow Balance during Recovery of Motor Hand Function after Ischemic Stroke—A Longitudinal MRI Study Using Arterial Spin Labeling Perfusion

    PubMed Central

    Missimer, John; Schroth, Gerhard; Hess, Christian W.; Sturzenegger, Matthias; Wang, Danny J. J.; Weder, Bruno; Federspiel, Andrea

    2014-01-01

    Background Unilateral ischemic stroke disrupts the well balanced interactions within bilateral cortical networks. Restitution of interhemispheric balance is thought to contribute to post-stroke recovery. Longitudinal measurements of cerebral blood flow (CBF) changes might act as surrogate marker for this process. Objective To quantify longitudinal CBF changes using arterial spin labeling MRI (ASL) and interhemispheric balance within the cortical sensorimotor network and to assess their relationship with motor hand function recovery. Methods Longitudinal CBF data were acquired in 23 patients at 3 and 9 months after cortical sensorimotor stroke and in 20 healthy controls using pulsed ASL. Recovery of grip force and manual dexterity was assessed with tasks requiring power and precision grips. Voxel-based analysis was performed to identify areas of significant CBF change. Region-of-interest analyses were used to quantify the interhemispheric balance across nodes of the cortical sensorimotor network. Results Dexterity was more affected, and recovered at a slower pace than grip force. In patients with successful recovery of dexterous hand function, CBF decreased over time in the contralesional supplementary motor area, paralimbic anterior cingulate cortex and superior precuneus, and interhemispheric balance returned to healthy control levels. In contrast, patients with poor recovery presented with sustained hypoperfusion in the sensorimotor cortices encompassing the ischemic tissue, and CBF remained lateralized to the contralesional hemisphere. Conclusions Sustained perfusion imbalance within the cortical sensorimotor network, as measured with task-unrelated ASL, is associated with poor recovery of dexterous hand function after stroke. CBF at rest might be used to monitor recovery and gain prognostic information. PMID:25191858

  9. Quantitative analysis of the impact of total ischemic time on myocardial perfusion and clinical outcome in patients with ST-elevation myocardial infarction.

    PubMed

    Fokkema, Marieke L; Wieringa, Wouter G; van der Horst, Iwan C; Boersma, Eric; Zijlstra, Felix; de Smet, Bart J

    2011-12-01

    Early reperfusion of the infarct-related coronary artery is an important issue in improvement of outcomes after ST-segment elevation myocardial infarction (STEMI). In this study, the clinical significance of total ischemic time on myocardial reperfusion and clinical outcomes was evaluated in patients with STEMI treated with primary percutaneous coronary intervention and thrombus aspiration and additional triple-antiplatelet therapy. Total ischemic time was defined as time from symptom onset to first intracoronary therapy (first balloon inflation or thrombus aspiration). All patients with STEMI treated with primary percutaneous coronary intervention with total ischemic times ≥30 minutes and <24 hours from 2005 to 2008 were selected. Ischemic times were available in 1,383 patients, of whom 18.4% presented with total ischemic times ≤2 hours, 31.2% >2 to 3 hours, 26.8% >3 to 5 hours, and 23.5% >5 hours. Increased ischemic time was associated with age, female gender, hypertension, and diabetes. Patients with total ischemic times <5 hours more often had myocardial blush grade 3 (40% to 45% vs 22%, p <0.001) and complete ST-segment resolution (55% to 60% vs 42%, p = 0.002) than their counterparts with total ischemic times >5 hours. In addition, patients with total ischemic times ≤5 hours had lower 30-day mortality (1.5% vs 4.0%, p = 0.032) than patients with total ischemic times >5 hours. In conclusion, in this contemporary cohort of patients with STEMI treated with primary percutaneous coronary intervention, triple-antiplatelet therapy, and thrombus aspiration, short ischemic time was associated with better myocardial reperfusion and decreased mortality. After a 5-hour period in which outcomes remain relatively stable, myocardial reperfusion becomes suboptimal and mortality increases. PMID:21906710

  10. Myocardial perfusion imaging for detection of silent myocardial ischemia

    SciTech Connect

    Beller, G.A.

    1988-04-21

    Despite the widespread use of the exercise stress test in diagnosing asymptomatic myocardial ischemia, exercise radionuclide imaging remains useful for detecting silent ischemia in numerous patient populations, including those who are totally asymptomatic, those who have chronic stable angina, those who have recovered from an episode of unstable angina or an uncomplicated myocardial infarction, and those who have undergone angioplasty or received thrombolytic therapy. Studies show that thallium scintigraphy is more sensitive than exercise electrocardiography in detecting ischemia, i.e., in part, because perfusion defects occur more frequently than ST depression and before angina in the ischemic cascade. Thallium-201 scintigraphy can be performed to differentiate a true- from a false-positive exercise electrocardiographic test in patients with exercise-induced ST depression and no angina. The development of technetium-labeled isonitriles may improve the accuracy of myocardial perfusion imaging. 11 references.

  11. Prevalence and pattern of abnormal myocardial perfusion in patients with isolated coronary artery ectasia: study by 99mTc-sestamibi radionuclide scintigraphy.

    PubMed

    Ismail, Ahmed M; Rayan, Mona; Adel, Amr; Demerdash, Salah; Atef, Mohamed; Abdallah, Mohamed; Nammas, Wail

    2014-02-01

    We explored the prevalence and pattern of abnormal myocardial perfusion in patients with isolated coronary artery ectasia (CAE), as demonstrated by (99m)Tc-sestamibi scintigraphy. Prospectively, we enrolled 35 patients with angiographically documented CAE and no significant coronary obstruction, who underwent elective coronary angiography. Patients underwent Stress-rest (99m)Tc-sestamibi scintigraphy within 4 days of coronary angiography. They were divided into 2 groups: group I: with normal perfusion scan; and group II: with reversible perfusion defects. The mean age was 49.6 ± 6.9 years; 34 (97.1 %) were males. Seventy-nine (75.2 %) arteries were affected by CAE. Among 79 arteries affected by CAE, affection was diffuse in 37 (46.8 %). Thirteen (37.1 %) patients had normal perfusion scan (group I), whereas 22 (62.9 %) had reversible perfusion defects (group II). Among 22 patients with reversible perfusion defects, 20 (90.9 %) had mild and 2 (9.1 %) had moderate ischemia. Among 49 myocardial segments with reversible perfusion defects, 22 (44.9 %) were basal, 18 (36.7 %) mid-, and 9 (18.4 %) apical segments. Diffuse CAE was significantly more prevalent in group II versus group I, in all 3 major coronary arteries (p < 0.05 for all). In patients with isolated CAE who underwent elective coronary angiography, reversible perfusion defects demonstrated by (99m)Tc-sestamibi scintigraphy were rather prevalent, mostly mild, more likely to affect the basal and mid-segments of the myocardium, and more frequently associated with diffuse ectasia.

  12. The study of cerebral ischemic reversibility: Part II. Preliminary preoperative results of fluoromethane positron emission tomographic determination of perfusion reserve in patients with carotid TIA and stroke.

    PubMed

    Levine, R L; Sunderland, J J; Rowe, B R; Nickles, R J

    1986-01-01

    Symmetries and asymmetries in regional cerebral blood flow (rCBF) determinations are reported in eleven patients with symptomatic carotid artery occlusive disease. Flourine-18-fluoromethane rCBF values are obtained by means of a noninvasive positron emission tomographic (PET) technique during room air (RA) and following induced hypercapnia (CO2). Areas of abnormal CO2 reactivity predict both the hemodynamic significance of the vascular lesion in question and the areas most vulnerable for ischemic infarction. This data is intended to be preliminary in nature; future expansions of this data base will be made to include rCBF/CO2 estimations, rCBF/glucose metabolism determinations, and rCBF/"reserve" evaluations over time and following brain-specific therapies. Once established, the potential viability and reversibility of these ischemic, uninfarcted or minimally infarcted areas can then be reestablished over time, thus providing a quantitative measure of the natural history of flow/metabolic coupling or uncoupling. PMID:3502524

  13. Comparison of endocardial electromechanical mapping with radionuclide perfusion imaging to assess myocardial viability and severity of myocardial ischemia in angina pectoris.

    PubMed

    Fuchs, S; Hendel, R C; Baim, D S; Moses, J W; Pierre, A; Laham, R J; Hong, M K; Kuntz, R E; Pietrusewicz, M; Bonow, R O; Mintz, G S; Leon, M B; Kornowski, R

    2001-04-01

    The assessment of left ventricular electromechanical activity using a novel, nonfluoroscopic 3-dimensional mapping system demonstrates considerable differences in electrical and mechanical activities within regions of myocardial infarction or ischemia. We sought to determine whether these changes correlate with indexes of myocardial perfusion, viability, or ischemia. A 12-segment comparative analysis was performed in 61 patients (45 men, 61 +/- 12 years old) with class III to IV angina, having reversible and/or fixed myocardial perfusion defects on single-photon emission computed tomographic perfusion imaging. A dual-isotope protocol was used, consisting of rest and 4-hour redistribution thallium images followed by adenosine technetium-99m sestamibi imaging. Average rest endocardial unipolar voltage (UpV) and local shortening (LS) mapping values were compared with visually derived perfusion scores. There was gradual and proportional reduction in regional UpV and LS in relation to thallium-201 uptake score at rest (p = 0.0001 and p = 0.0002, respectively) and redistribution studies (p = 0.0001 and p = 0.003, respectively). UpV > or = 7.4 mV and LS > or = 5.0% had a sensitivity of 78% and 65%, respectively, with a specificity of 68% and 67% for detecting viable myocardium. UpV values of 12.3 and 5.4 mV had 90% specificity and sensitivity, respectively, to predict viable tissue. UpV, but not LS, values differentiated between normal segments and those with adenosine-induced severe perfusion defects (11.8 +/- 5.3 vs 8.8 +/- 4.1 mV, p = 0.005). Catheter-based left ventricular assessment of electromechanical activity correlates with the degree of single-photon emission computed tomographic perfusion abnormality and can identify myocardial viability with a greater accuracy than myocardial ischemia.

  14. MR Assessment of Myocardial Perfusion, Viability, and Function after Intramyocardial Transfer of VM202, a New Plasmid Human Hepatocyte Growth Factor in Ischemic Swine Myocardium1

    PubMed Central

    Saeed, Maythem; Martin, Alastair; Ursell, Phillip; Do, Loi; Bucknor, Matt; Higgins, Charles B.; Saloner, David

    2008-01-01

    Purpose: VM202, a newly constructed plasmid human hepatocyte growth factor, was transferred intramyocardially after infarction for the purpose of evaluating this strategy as a therapeutic approach for protection from left ventricular (LV) remodeling. Materials and Methods: The institutional animal care and use committee approved this study. Pigs underwent coronary artery occlusion and reperfusion and served as either control (n = 8) or VM202-treated (n = 8) animals. VM202 was transferred intramyocardially into four infarcted and four periinfarcted sites. Cardiac magnetic resonance (MR) imaging (cine, perfusion, delayed enhancement) was performed in acute (3 days) and chronic (50 days ± 3 [standard error of the mean]) infarction. Histopathologic findings were used to characterize and quantify neovascularization. The t test was utilized to compare treated and control groups and to assess changes over time. Results: In acute infarction, MR imaging estimates of function, perfusion, and viability showed no difference between the groups. In chronic infarction, however, VM202 increased maximum signal intensity and upslope at first-pass perfusion imaging and reduced infarct size at perfusion and delayed-enhancement imaging. These changes were associated with a decrease in end-diastolic (2.15 mL/kg ± 0.12 to 1.73 mL/kg ± 0.10, P < .01) and end-systolic (1.33 mL/kg ± 0.07 to 0.92 mL/kg ± 0.08, P < .001) volumes and an increase in ejection fraction (38.2% ± 1.3 to 47.0% ± 1.8, P < .001). In contrast, LV function deteriorated further in control animals. Compared with control animals, VM202-treated animals revealed peninsulas and/or islands of viable myocardium in infarcted and periinfarcted regions and greater number of capillaries (218 per square millimeter ± 19 vs 119 per square millimeter ± 17, P < .05) and arterioles (21 per square millimeter ± 4 vs 3 per square millimeter ± 1, P < .001). Conclusion: Intramyocardial transfer of VM202 improved myocardial

  15. Effect of Diltiazem on Coronary Artery Flow and Myocardial Perfusion in Patients With Isolated Coronary Artery Ectasia and Either Stable Angina Pectoris or Positive Myocardial Ischemic Stress Test.

    PubMed

    Ozcan, Ozgur Ulas; Atmaca, Yusuf; Goksuluk, Huseyin; Akbulut, Irem Muge; Ozyuncu, Nil; Ersoy, Nedret; Erol, Cetin

    2015-10-15

    Isolated coronary artery ectasia (CAE) may be associated with stable or unstable coronary events despite the absence of epicardial coronary stenosis. Impaired coronary flow dynamics and myocardial perfusion have been demonstrated in stable patients with ectatic coronary arteries. We aimed to assess whether epicardial flow and tissue-level perfusion would be improved by diltiazem in myocardial regions subtended by the ectatic coronary arteries in patients with isolated CAE. A total of 60 patients with isolated CAE were identified of 9,780 patients who underwent elective coronary angiography. Patients were randomized to 5 mg of intracoronary diltiazem or saline. Coronary blood flow of the microvascular network was assessed using myocardial blush grade (MBG) technique. The thrombolysis in myocardial infarction (TIMI) flow grade and TIMI frame count (TFC) were used to assess epicardial coronary flow. MBG (from 2.4 to 2.6, p = 0.02), TIMI flow grades (from 2.4 to 2.8, p <0.001), and TFC (from 35 to 26, p <0.001) were significantly improved after diltiazem, whereas no significant change was noticed after saline (from 2.4 to 2.4, p = 0.86 for MBG; from 2.3 to 2.3, p = 0.71 for TIMI flow grade; and from 35 to 33, p = 0.43 for TFC). Diltiazem provided amelioration of the altered coronary flow dynamics, which was suggested as the pathophysiological influence of CAE. In conclusion, the favorable effects of the diltiazem on myocardial perfusion were observed at both epicardial and tissue levels.

  16. TLR4 Deters Perfusion Recovery and Upregulates Toll-like Receptor 2 (TLR2) in Ischemic Skeletal Muscle and Endothelial Cells

    PubMed Central

    Xu, Jia; Benabou, Kelly; Cui, Xiangdong; Madia, Marissa; Tzeng, Edith; Billiar, Timothy; Watkins, Simon; Sachdev, Ulka

    2015-01-01

    Toll-like receptors (TLRs) play an important role in regulating muscle regeneration and angiogenesis in response to ischemia. TLR2 knockout mice exhibit pronounced skeletal muscle necrosis and abnormal vessel architecture after femoral artery ligation, suggesting that TLR2 signaling is protective during ischemia. TLR4, an important receptor in inflammatory signaling, has been shown to regulate TLR2 expression in other systems. We hypothesize that a similar relationship between TLR4 and TLR2 may exist in hindlimb ischemia in which TLR4 upregulates TLR2, a mediator of angiogenesis and perfusion recovery. We examined the expression of TLR2 in unstimulated and in TLR-agonist treated endothelial cells (ECs). TLR2 expression (low in control ECs) was upregulated by lipopolysaccharide, the danger signal high mobility group box-1, and hypoxia in a TLR4-dependent manner. Endothelial tube formation on Matrigel as well as EC permeability was assessed as in vitro measures of angiogenesis. Time-lapse imaging demonstrated that ECs lacking TLR4 formed more tubes, whereas TLR2 knockdown ECs exhibited attenuated tube formation. TLR2 also mediated EC permeability, an initial step during angiogenesis, in response to high-mobility group box-1 (HMGB1) that is released by cells during hypoxic injury. In vivo, ischemia-induced upregulation of TLR2 required intact TLR4 signaling that mediated systemic inflammation, as measured by local and systemic IL-6 levels. Similar to our in vitro findings, vascular density and limb perfusion were both enhanced in the absence of TLR4 signaling, but not if TLR2 was deleted. These findings indicate that TLR2, in the absence of TLR4, improves angiogenesis and perfusion recovery in response to ischemia. PMID:26181630

  17. Study of cerebral ischemic reversibility: Part II. Preliminary preoperative results of fluoromethane positron emission tomographic determination of perfusion reserve in patients with carotid TIA and stroke

    SciTech Connect

    Levine, R.L.; Sunderland, J.J.; Rowe, B.R.; Nickles, R.J.

    1986-01-01

    Symmetries and asymmetries in regional cerebral blood flow (rCBF) determinations are reported in eleven patients with symptomatic carotid artery occlusive disease. Flourine-18-fluoromethane rCBF values are obtained by means of a noninvasive positron emission tomographic (PET) technique during room air (RA) and following induced hypercapnia (CO/sub 2/). Areas of abnormal CO/sub 2/ reactivity predict both the hemodynamic significance of the vascular lesion in question and the areas most vulnerable for ischemic infarction. This data is intended to be preliminary in nature; future expansions of this data base will be made to include rCBF/CO/sub 2/ estimations, rCBF/glucose metabolism determinations, and rCBF/reserve evaluations over time and following brain-specific therapies. Once established, the potential viability and reversibility of these ischemic, uninfarcted or minimally infarcted areas can then be reestablished over time, thus providing a quantitative measure of the natural history of flow/metabolic coupling or uncoupling.

  18. Radionuclide surveillance of the allografted pancreas

    SciTech Connect

    George, E.A.; Salimi, Z.; Carney, K.; Castaneda, M.; Garvin, P.J.

    1988-04-01

    To determine the value of scintigraphy to detect posttransplantation complications of the allografted pancreas, we retrospectively reviewed 209 scintigrams obtained with /sup 99m/Tc-sulfur colloid (/sup 99m/Tc-SC) and /sup 99m/Tc-glucoheptonate (/sup 99m/Tc-GH). The scintigraphic studies were performed in 37 recipients of simultaneous renal and pancreatic allografts harvested from the same donor. /sup 99m/Tc-SC was used as an indicator of thrombotic vasculitis; pancreatic perfusion and blood-pool parameters were monitored with /sup 99m/Tc-GH. In 11 of the 37 recipients, scintigraphic abnormalities suggested posttransplantation infarction. Recurrent episodes of acute rejection of the pancreatic allograft, which always coincided with acute rejection of the renal allograft, were monitored in 24 recipients. Rejection-induced ischemic pancreatitis was suggested in 12 of the 24 recipients and persisted in 10 recipients for several weeks after improvement of renal allograft rejection. Pancreatic atrophy was suggested scintigraphically in 16 of the 24 recipients with recurrent episodes of rejection. Spontaneous pancreatic-duct obstruction and obstructive pancreatitis were associated with a scintigraphic pattern similar to that of rejection-induced ischemic pancreatitis. We concluded that the specific radionuclides used in this series are useful for the surveillance and assessment of posttransplantation pancreatic infarction, acute rejection, pancreatitis, and atrophy

  19. Ischemic Stroke

    MedlinePlus

    A stroke is a medical emergency. There are two types - ischemic and hemorrhagic. Ischemic stroke is the most common type. It is usually ... are at risk for having a more serious stroke. Symptoms of stroke are Sudden numbness or weakness ...

  20. Video instrumentation for radionuclide angiocardiography.

    NASA Technical Reports Server (NTRS)

    Kriss, J. P.

    1973-01-01

    Two types of videoscintiscopes for performing radioisotopic angiocardiography with a scintillation camera are described, and use of these instruments in performing clinical studies is illustrated. Radionuclide angiocardiography is a simple, quick and accurate procedure recommended as a screening test for patients with a variety of congenital and acquired cardiovascular lesions. When performed in conjunction with coronary arterial catheterization, dynamic radionuclide angiography may provide useful information about regional myocardial perfusion. Quantitative capabilities greatly enhance the potential of this diagnostic tool.

  1. Radionuclide Therapy

    NASA Astrophysics Data System (ADS)

    Zalutsky, M. R.

    Radionuclide therapy utilizes unsealed sources of radionuclides as a treatment for cancer or other pathological conditions such as rheumatoid arthritis. Radionuclides that decay by the emission of β and α particles, as well as those that emit Auger electrons, have been used for this purpose. In this chapter, radiochemical aspects of radionuclide therapy, including criteria for radionuclide selection, radionuclide production, radiolabeling chemistry, and radiation dosimetry are discussed.

  2. Brain perfusion: computed tomography and magnetic resonance techniques.

    PubMed

    Copen, William A; Lev, Michael H; Rapalino, Otto

    2016-01-01

    Cerebral perfusion imaging provides assessment of regional microvascular hemodynamics in the living brain, enabling in vivo measurement of a variety of different hemodynamic parameters. Perfusion imaging techniques that are used in the clinical setting usually rely upon X-ray computed tomography (CT) or magnetic resonance imaging (MRI). This chapter reviews CT- and MRI-based perfusion imaging techniques, with attention to image acquisition, clinically relevant aspects of image postprocessing, and fundamental differences between CT- and MRI-based techniques. Correlations with cerebrovascular physiology and potential clinical applications of perfusion imaging are reviewed, focusing upon the two major classes of neurologic disease in which perfusion imaging is most often performed: primary perfusion disorders (including ischemic stroke, transient ischemic attack, and reperfusion syndrome), and brain tumors.

  3. Clinical Decision Making With Myocardial Perfusion Imaging in Patients With Known or Suspected Coronary Artery Disease

    PubMed Central

    Cremer, Paul; Hachamovitch, Rory; Tamarappoo, Balaji

    2015-01-01

    Myocardial perfusion imaging (MPI) to diagnose coronary artery disease (CAD) is best performed in patients with intermediate pretest likelihood of disease; unfortunately, pretest likelihood is often overestimated, resulting in the inappropriate use of perfusion imaging. A good functional capacity often predicts low risk, and MPI for diagnosing CAD should be reserved for individuals with poor exercise capacity, abnormal resting electrocardiography, or an intermediate or high probability of CAD. With respect to anatomy-based testing, coronary CT angiography has a good negative predictive value, but stenosis severity correlates poorly with ischemia. Therefore decision making with respect to revascularization may be limited when a purely noninvasive anatomical test is used. Regarding perfusion imaging, the diagnostic accuracies of SPECT, PET, and cardiac magnetic resonance are similar, though fewer studies are available with cardiac magnetic resonance. PET coronary flow reserve may offer a negative predictive value sufficiently high to exclude severe CAD such that patients with mild to moderate reversible perfusion defects can forego invasive angiography. In addition, combined anatomical and perfusion-based imaging may eventually offer a definitive evaluation for diagnosing CAD, even in higher risk patients. Any remarkable findings on single-photon emission computed tomography and PET MPI studies are valuable for prognostication. Furthermore, assessment of myocardial blood flow with PET is particularly powerful for prognostication as it reflects the end result of many processes that lead to atherosclerosis. Decision making with respect to revascularization is limited for cardiac MRI and PET MPI. In contrast, retrospective radionuclide studies have identified an ischemic threshold, but randomized trials are needed. In patients with at least moderately reduced left ventricular systolic function, viable myocardium as assessed by PET or MRI, appears to identify patients

  4. Radionuclide trap

    DOEpatents

    McGuire, Joseph C.

    1978-01-01

    The deposition of radionuclides manganese-54, cobalt-58 and cobalt-60 from liquid sodium coolant is controlled by providing surfaces of nickel or high nickel alloys to extract the radionuclides from the liquid sodium, and by providing surfaces of tungsten, molybdenum or tantalum to prevent or retard radionuclide deposition.

  5. Tissue-specific sparse deconvolution for brain CT perfusion.

    PubMed

    Fang, Ruogu; Jiang, Haodi; Huang, Junzhou

    2015-12-01

    Enhancing perfusion maps in low-dose computed tomography perfusion (CTP) for cerebrovascular disease diagnosis is a challenging task, especially for low-contrast tissue categories where infarct core and ischemic penumbra usually occur. Sparse perfusion deconvolution has been recently proposed to effectively improve the image quality and diagnostic accuracy of low-dose perfusion CT by extracting the complementary information from the high-dose perfusion maps to restore the low-dose using a joint spatio-temporal model. However the low-contrast tissue classes where infarct core and ischemic penumbra are likely to occur in cerebral perfusion CT tend to be over-smoothed, leading to loss of essential biomarkers. In this paper, we propose a tissue-specific sparse deconvolution approach to preserve the subtle perfusion information in the low-contrast tissue classes. We first build tissue-specific dictionaries from segmentations of high-dose perfusion maps using online dictionary learning, and then perform deconvolution-based hemodynamic parameters estimation for block-wise tissue segments on the low-dose CTP data. Extensive validation on clinical datasets of patients with cerebrovascular disease demonstrates the superior performance of our proposed method compared to state-of-art, and potentially improve diagnostic accuracy by increasing the differentiation between normal and ischemic tissues in the brain. PMID:26055434

  6. Tissue-specific sparse deconvolution for brain CT perfusion.

    PubMed

    Fang, Ruogu; Jiang, Haodi; Huang, Junzhou

    2015-12-01

    Enhancing perfusion maps in low-dose computed tomography perfusion (CTP) for cerebrovascular disease diagnosis is a challenging task, especially for low-contrast tissue categories where infarct core and ischemic penumbra usually occur. Sparse perfusion deconvolution has been recently proposed to effectively improve the image quality and diagnostic accuracy of low-dose perfusion CT by extracting the complementary information from the high-dose perfusion maps to restore the low-dose using a joint spatio-temporal model. However the low-contrast tissue classes where infarct core and ischemic penumbra are likely to occur in cerebral perfusion CT tend to be over-smoothed, leading to loss of essential biomarkers. In this paper, we propose a tissue-specific sparse deconvolution approach to preserve the subtle perfusion information in the low-contrast tissue classes. We first build tissue-specific dictionaries from segmentations of high-dose perfusion maps using online dictionary learning, and then perform deconvolution-based hemodynamic parameters estimation for block-wise tissue segments on the low-dose CTP data. Extensive validation on clinical datasets of patients with cerebrovascular disease demonstrates the superior performance of our proposed method compared to state-of-art, and potentially improve diagnostic accuracy by increasing the differentiation between normal and ischemic tissues in the brain.

  7. The Effects of Methylene Blue on Autophagy and Apoptosis in MRI-Defined Normal Tissue, Ischemic Penumbra and Ischemic Core

    PubMed Central

    Jiang, Zhao; Watts, Lora Talley; Huang, Shiliang; Shen, Qiang; Rodriguez, Pavel; Chen, Chunhua; Zhou, Changman; Duong, Timothy Q.

    2015-01-01

    Methylene blue (MB) USP, which has energy-enhancing and antioxidant properties, is currently used to treat methemoglobinemia and cyanide poisoning in humans. We recently showed that MB administration reduces infarct volume and behavioral deficits in rat models of ischemic stroke and traumatic brain injury. This study reports the underlying molecular mechanisms of MB neuroprotection following transient ischemic stroke in rats. Rats were subjected to transient (60-mins) ischemic stroke. Multimodal MRI during the acute phase and at 24hrs were used to define three regions of interest (ROIs): i) the perfusion-diffusion mismatch salvaged by reperfusion, ii) the perfusion-diffusion mismatch not salvaged by reperfusion, and iii) the ischemic core. The tissues from these ROIs were extracted for western blot analyses of autophagic and apoptotic markers. The major findings were: 1) MB treatment reduced infarct volume and behavioral deficits, 2) MB improved cerebral blood flow to the perfusion-diffusion mismatch tissue after reperfusion and minimized harmful hyperperfusion 24hrs after stroke, 3) MB inhibited apoptosis and enhanced autophagy in the perfusion-diffusion mismatch, 4) MB inhibited apoptotic signaling cascades (p53-Bax-Bcl2-Caspase3), and 5) MB enhanced autophagic signaling cascades (p53-AMPK-TSC2-mTOR). MB induced neuroprotection, at least in part, by enhancing autophagy and reducing apoptosis in the perfusion-diffusion mismatch tissue following ischemic stroke. PMID:26121129

  8. Neurovascular Regulation in the Ischemic Brain

    PubMed Central

    Jackman, Katherine

    2015-01-01

    Abstract Significance: The brain has high energetic requirements and is therefore highly dependent on adequate cerebral blood supply. To compensate for dangerous fluctuations in cerebral perfusion, the circulation of the brain has evolved intrinsic safeguarding measures. Recent Advances and Critical Issues: The vascular network of the brain incorporates a high degree of redundancy, allowing the redirection and redistribution of blood flow in the event of vascular occlusion. Furthermore, active responses such as cerebral autoregulation, which acts to maintain constant cerebral blood flow in response to changing blood pressure, and functional hyperemia, which couples blood supply with synaptic activity, allow the brain to maintain adequate cerebral perfusion in the face of varying supply or demand. In the presence of stroke risk factors, such as hypertension and diabetes, these protective processes are impaired and the susceptibility of the brain to ischemic injury is increased. One potential mechanism for the increased injury is that collateral flow arising from the normally perfused brain and supplying blood flow to the ischemic region is suppressed, resulting in more severe ischemia. Future Directions: Approaches to support collateral flow may ameliorate the outcome of focal cerebral ischemia by rescuing cerebral perfusion in potentially viable regions of the ischemic territory. Antioxid. Redox Signal. 22, 149–160. PMID:24328757

  9. Developing a tissue perfusion sensor.

    PubMed

    Harvey, S L R; Parker, K H; O'Hare, D

    2007-01-01

    The development of a electrochemical tissue perfusion sensor is presented. The sensor is a platinum/platinum ring-disc microelectrode that relies on the principle of collector-generator to monitor mass transport within its vicinity. Tissue perfusion is a mass transport mechanism that describes the movement of respiratory gases, nutrients and metabolites in tissue. The sensor's capability of detecting perfusion at the cellular level in a continuous fashion is unique. This sensor will provide insight into the way nutrients and metabolites are transported in tissue especially in cases were perfusion is low such as in wounds or ischemic tissue. We present experimental work for the development and testing of the sensors in vitro. Experimental flow recordings in free steam solutions as well as the flow through tissue-like media are shown. Tests on post operative human tissue are also presented. The sensor's feature such as the continuous recoding capacities, spatial resolution and the measurement range from ml/min to microl/min are highlighted. PMID:18002549

  10. Ischemic postconditioning protects against ischemic brain injury by up-regulation of acid-sensing ion channel 2a

    PubMed Central

    Duanmu, Wang-sheng; Cao, Liu; Chen, Jing-yu; Ge, Hong-fei; Hu, Rong; Feng, Hua

    2016-01-01

    Ischemic postconditioning renders brain tissue tolerant to brain ischemia, thereby alleviating ischemic brain injury. However, the exact mechanism of action is still unclear. In this study, a rat model of global brain ischemia was subjected to ischemic postconditioning treatment using the vessel occlusion method. After 2 hours of ischemia, the bilateral common carotid arteries were blocked immediately for 10 seconds and then perfused for 10 seconds. This procedure was repeated six times. Ischemic postconditioning was found to mitigate hippocampal CA1 neuronal damage in rats with brain ischemia, and up-regulate acid-sensing ion channel 2a expression at the mRNA and protein level. These findings suggest that ischemic postconditioning up-regulates acid-sensing ion channel 2a expression in the rat hippocampus after global brain ischemia, which promotes neuronal tolerance to ischemic brain injury. PMID:27212927

  11. Ischemic Colitis

    PubMed Central

    FitzGerald, James F.; Hernandez III, Luis O.

    2015-01-01

    Most clinicians associate ischemic colitis with elderly patients who have underlying cardiovascular comorbidities. While the majority of cases probably occur in this population, the disease can present in younger patients as a result of different risk factors, making the diagnosis challenging. While a majority of patients respond to medical management, surgery is required in approximately 20% of the cases and is associated with high morbidity and mortality. PMID:26034405

  12. Radionuclide cisternogram

    MedlinePlus

    ... please enable JavaScript. A radionuclide cisternogram is a nuclear scan test. It is used to diagnose problems ... damage. The amount of radiation used during the nuclear scan is very small. Almost all of the ...

  13. Hyperspectral imaging of ischemic wounds

    NASA Astrophysics Data System (ADS)

    Gnyawali, Surya C.; Elgharably, Haytham; Melvin, James; Huang, Kun; Bergdall, Valerie; Allen, David W.; Hwang, Jeeseong; Litorja, Maritoni; Shirley, Eric; Sen, Chandan K.; Xu, Ronald

    2012-03-01

    Optical imaging has the potential to achieve high spatial resolution and high functional sensitivity in wound assessment. However, clinical acceptance of many optical imaging devices is hampered by poor reproducibility, low accuracy, and lack of biological interpretation. We developed an in vivo model of ischemic flap for non-contact assessment of wound tissue functional parameters and spectral characteristics. The model was created by elevating the bipedicle skin flaps of a domestic pig from the underlying vascular bed and inhibiting graft bed reperfusion by a silastic sheet. Hyperspectral imaging was carried out on the ischemic flap model and compared with transcutaneous oxygen tension and perfusion measurements at different positions of the wound. Hyperspectral images have also been captured continuously during a post-occlusive reactive hyperemia (PORH) procedure. Tissue spectral characteristics obtained by hyperspectral imaging correlated well with cutaneous tissue oxygen tension, blood perfusion, and microscopic changes of tissue morphology. Our experiments not only demonstrated the technical feasibility for quantitative assessment of chronic wound but also provided a potential digital phantom platform for quantitative characterization and calibration of medical optical devices.

  14. An update on brain imaging in transient ischemic attack.

    PubMed

    Souillard-Scemama, R; Tisserand, M; Calvet, D; Jumadilova, D; Lion, S; Turc, G; Edjlali, M; Mellerio, C; Lamy, C; Naggara, O; Meder, J-F; Oppenheim, C

    2015-02-01

    Neuroimaging is critical in the evaluation of patients with transient ischemic attack (TIA) and MRI is the recommended modality to image an ischemic lesion. The presence of a diffusion (DWI) lesion in a patient with transient neurological symptoms confirms the vascular origin of the deficit and is predictive of a high risk of stroke. Refinement of MR studies including high resolution DWI and perfusion imaging using either MRI or CT further improve the detection of ischemic lesions. Rapid etiological work-up includes non-invasive imaging of cervical and intracranial arteries to search for symptomatic stenosis/occlusion associated with an increased risk of stroke.

  15. Noninvasive assessment of changes in myocardial perfusion and ventricular performance following exercise training

    SciTech Connect

    Tubau, J.; Witztum, K.; Froelicher, V.; Jensen, D.; Atwood, E.; McKirnan, M.D.; Reynolds, J.; Ashburn, W.

    1982-08-01

    Seventeen coronary patients (CAD) underwent /sup 201/Tl treadmill and radionuclide (RNV) ejection fraction supine bicycle testing before and after 5.6 +/- 1.6 (mean +/- SD) months of an exercise program. Thallium data were assessed both using analog images and a computerized circumferential profile technique. Patients exercised on the treadmill to a higher workload after the exercise program, but achieved a similar pressure-rate product. When interpreting the analog thallium images, only 50% agreement was obtained for the assessment of changes in myocardial perfusion (pre/post-training). The computer technique, however, had low inter-intraobserver variability (6%) and better agreement (90.5%). Using the circumferential profile method, five patients improved (a total of 11 regions) and one patient worsened (with two regions). Before the exercise program, the ejection fraction (EF) response to supine bike exercise was normal (an increase greater than 11%) in four, flat in seven, and severely abnormal (a decrease of more than 4%) in six patients. After the exercise program, even though achieving similar or higher pressure-rate products, six patients improved their EF response, nine did not change, and two worsened. Of the five patients who improved their thallium images, one improved his EF response, two remained normal, and two did not change. One patient worsened both his thallium study and the EF response after the exercise program. Changes in thallium exercise images and the EF response to supine exercise occurred in our patients after an exercise program, but were not always concordant. Indeed, of five patients with exercise-induced ischemic ST changes before and after training, the EF response improved in three whereas myocardial perfusion was unchanged. Reasons for this lack of agreement are discussed, and have been considered in the planning of a randomized trial of the effects of an exercise program on myocardial perfusion and function.

  16. White Matter Ischemic Changes in Hyperacute Ischemic Stroke

    PubMed Central

    Trouard, Theodore P; Lafleur, Scott R.; Krupinski, Elizabeth A.; Salamon, Noriko; Kidwell, Chelsea S.

    2015-01-01

    Background and Purpose— The purpose of this study was to evaluate changes in fractional anisotropy (FA), as measured by diffusion tensor imaging, of white matter (WM) infarction and hypoperfusion in patients with acute ischemic stroke using a quantitative voxel-based analysis. Methods— In this prospective study, diffusion tensor imaging and dynamic susceptibility contrast perfusion sequences were acquired in 21 patients with acute ischemic stroke who presented within 6 hours of symptom onset. The coregistered FA, apparent diffusion coefficient, and dynamic susceptibility contrast time to maximum (Tmax) maps were used for voxel-based quantification using a region of interest approach in the ipsilateral affected side and in the homologous contralateral WM. The regions of WM infarction versus hypoperfusion were segmented using a threshold method. Data were analyzed by regression and ANOVA. Results— There was an overall significant mean difference (P<0.001) for the apparent diffusion coefficient, Tmax, and FA values between the normal, hypoperfused, and infarcted WM. The mean±SD of FA was significantly higher (P<0.001) in hypoperfused WM (0.397±0.019) and lower (P<0.001) in infarcted WM (0.313±0.037) when compared with normal WM (0.360±0.020). Regression tree analysis of hypoperfused WM showed the largest mean FA difference at Tmax above versus below 5.4 s with a mean difference of 0.033 (P=0.0096). Conclusions— Diffusion tensor imaging-FA was decreased in regions of WM infarction and increased in hypoperfused WM in patients with hyperacute acute ischemic stroke. The significantly increased FA values in the hypoperfused WM with Tmax≥5.4 s are suggestive of early ischemic microstructural changes. PMID:25523053

  17. Assessment of Ischemic Cardiomyopathy Using Cardiovascular Magnetic Resonance Imaging: A Pictorial Review

    PubMed Central

    Olivas-Chacon, Cristina Ivette; Mullins, Carola; Solberg, Agnieszka; Akle, Nassim; Calleros, Jesus E; Ramos-Duran, Luis R

    2015-01-01

    Ischemic heart disease is the leading cause of death worldwide. In the last two decades, cardiovascular magnetic resonance imaging (CMRI) has emerged as the primary imaging tool in the detection and prognostic assessment of ischemic heart disease. In a single study, CMRI allows evaluation of not only myocardial wall perfusion, but also the presence, acuity, and extent of myocardial ischemia and infarction complications. Also, rest and stress perfusion imaging can accurately depict inducible ischemia secondary to significant coronary artery stenosis. We present a pictorial review of the assessment of ischemic cardiomyopathy with an emphasis on CMRI features. PMID:26085960

  18. Microfluidic perfusion culture.

    PubMed

    Hattori, Koji; Sugiura, Shinji; Kanamori, Toshiyuki

    2014-01-01

    Microfluidic perfusion culture is a novel technique to culture animal cells in a small-scale microchamber with medium perfusion. Polydimethylsiloxane (PDMS) is the most popular material to fabricate a microfluidic perfusion culture chip. Photolithography and replica molding techniques are generally used for fabrication of a microfluidic perfusion culture chip. Pressure-driven perfusion culture system is convenient technique to carry out the perfusion culture of animal cells in a microfluidic device. Here, we describe a general theory on microfluid network design, microfabrication technique, and experimental technique for pressure-driven perfusion culture in an 8 × 8 microchamber array on a glass slide-sized microchip made out of PDMS. PMID:24297421

  19. Ischemic preconditioning protects against ischemic brain injury

    PubMed Central

    Ma, Xiao-meng; Liu, Mei; Liu, Ying-ying; Ma, Li-li; Jiang, Ying; Chen, Xiao-hong

    2016-01-01

    In this study, we hypothesized that an increase in integrin αvβ3 and its co-activator vascular endothelial growth factor play important neuroprotective roles in ischemic injury. We performed ischemic preconditioning with bilateral common carotid artery occlusion for 5 minutes in C57BL/6J mice. This was followed by ischemic injury with bilateral common carotid artery occlusion for 30 minutes. The time interval between ischemic preconditioning and lethal ischemia was 48 hours. Histopathological analysis showed that ischemic preconditioning substantially diminished damage to neurons in the hippocampus 7 days after ischemia. Evans Blue dye assay showed that ischemic preconditioning reduced damage to the blood-brain barrier 24 hours after ischemia. This demonstrates the neuroprotective effect of ischemic preconditioning. Western blot assay revealed a significant reduction in protein levels of integrin αvβ3, vascular endothelial growth factor and its receptor in mice given ischemic preconditioning compared with mice not given ischemic preconditioning 24 hours after ischemia. These findings suggest that the neuroprotective effect of ischemic preconditioning is associated with lower integrin αvβ3 and vascular endothelial growth factor levels in the brain following ischemia. PMID:27335560

  20. Effect of diltiazem on myocardial infarct size estimated by enzyme release, serial thallium-201 single-photon emission computed tomography and radionuclide angiography

    SciTech Connect

    Zannad, F.; Amor, M.; Karcher, G.; Maurin, P.; Ethevenot, G.; Sebag, C.; Bertrand, A.; Pernot, C.; Gilgenkrantz, J.M.

    1988-06-01

    Diltiazem is a calcium antagonist with demonstrated experimental cardioprotective effects. Its effects on myocardial infarct size were studied in 34 patients admitted within 6 hours after the first symptoms of acute myocardial infarction. These patients were randomized, double-blind to placebo or diltiazem (10-mg intravenous bolus followed by 15 mg/hr intravenous infusion during 72 hours, followed by 4 X 60 mg during 21 days). Myocardial infarct size was assessed by plasma creatine kinase and creatine kinase-MB indexes, perfusion defect scores using single-photon emission computed tomography with thallium-201 and left ventricular ejection fraction measured by radionuclide angiography. Tomographic and angiographic scanning was performed serially before randomization, after 48 hours and 21 days later. Groups were comparable in terms of age, sex, inclusion time and baseline infarct location and size. Results showed no difference in creatine kinase and creatine kinase-MB data between controls and treated patients, a significant decrease in the perfusion defect scores in the diltiazem group (+0.1 +/- 3.0 placebo vs -2.2 +/- 1.9 diltiazem, p less than 0.02) and a better ejection fraction recovery in the diltiazem group (-4.2 +/- 7.4 placebo vs +7.7 +/- 11.2 diltiazem, p less than 0.05). Myocardial infarct size estimates from perfusion defect scores and enzyme data were closely correlated. These preliminary results suggest that diltiazem may reduce ischemic injury in acute myocardial infarction.

  1. Radionuclide removal

    SciTech Connect

    Sorg, T.J.

    1991-01-01

    The U.S. Environmental Protection Agency proposed new and revised regulations on radionuclide contaminants in drinking water in June 1991. During the 1980's, the Drinking Water Research Division, USEPA conducted a research program to evaluate various technologies to remove radium, uranium and radon from drinking water. The research consisted of laboratory and field studies conducted by USEPA, universities and consultants. The paper summarizes the results of the most significant projects completed. General information is also presented on the general chemistry of the three radionuclides. The information presented indicates that the most practical treatment methods for radium are ion exchange and lime-soda softening and reverse osmosis. The methods tested for radon are aeration and granular activated carbon and the methods for uranium are anion exchange and reverse osmosis.

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

    PubMed Central

    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

  3. Pulmonary ventilation/perfusion scan

    MedlinePlus

    V/Q scan; Ventilation/perfusion scan; Lung ventilation/perfusion scan ... A pulmonary ventilation/perfusion scan is actually two tests. They may be done separately or together. During the perfusion scan, a health care ...

  4. [Neuroimaging of the penumbra in ischemic stroke].

    PubMed

    Maksimova, M Iu; Korobkova, D Z; Krotenkova, M V

    2013-01-01

    Brain ischemia has been recently a central problem in basic and applied studies in angioneurology. The latest investigations that give an insight into a relationship between metabolic changes and cerebral blood flow and make it possible to study ischemia at the molecular level and its changes over time have promoted the accumulation of fundamentally new facts and some reappraisal of existing ideas. Ischemic semishadow or penumbra is one of the most important presently studied phenomena. Detection of penumbra signs suggests that it is expedient to evaluate cerebral blood flow and metabolism when planning treatment (thrombolysis or neuroprotective therapy) and that it is important to predict the severity of ischemic stroke. Positron emission tomography (PET) is the reference method for detecting the penumbra; however, its application is limited in clinical practice. Computed tomography (CT) perfusion and perfusion MRI, a combination of diffusion-weighted and perfusion MRI, single-photon emission CT, and xenon-enhanced CT are most frequently used to evaluate a cerebral ischemia area and its blood flow. However, there are no standardized approaches to quantifying the thresholds for cerebral blood flow or unified algorithms for penumbra verification, which calls for further investigations. PMID:25702445

  5. Analysis of first-pass myocardial perfusion MRI using independent component analysis

    NASA Astrophysics Data System (ADS)

    Milles, Julien; van der Geest, Rob J.; Jerosch-Herold, Michael; Reiber, Johan H. C.; Lelieveldt, Boudewijn P. F.

    2006-03-01

    Myocardial perfusion MRI has emerged as a suitable imaging technique for the detection of ischemic regions of the heart. However, manual post-processing is labor intensive, seriously hampering its daily clinical use. We propose a novel, data driven analysis method based on Independent Component Analysis (ICA). By performing ICA on the complete perfusion sequence, physiologically meaningful feature images, representing events occurring during the perfusion sequence, can be factored out. Results obtained using our method are compared with results obtained using manual contouring by a medical expert. The estimated weight functions are correlated against the perfusion time-intensity curves from manual contours, yielding promising results.

  6. Radionuclide evaluation of lung trauma

    SciTech Connect

    Lull, R.J.; Tatum, J.L.; Sugerman, H.J.; Hartshorne, M.F.; Boll, D.A.; Kaplan, K.A.

    1983-07-01

    Nuclear medicine imaging procedures can play a significant role in evaluating the pulmonary complications that are seen in trauma patients. A quantitative method for measuring increased pulmonary capillary permeability that uses Tc-99m HSA allows early diagnosis of acute respiratory distress syndrome (ARDS) and accurately differentiates this condition from pneumonia or cardiogenic pulmonary edema. This technique may be of great value in following the response to therapy. The use of 133Xe to diagnose inhalation injury remains an important diagnostic tool, particularly at hospitals with specialized burn units. Regional decreases in ventilation-perfusion images reliably localize aspirated foreign bodies. Radionuclide techniques that are used to demonstrate gastropulmonary aspiration remain controversial and require further clinical evaluation. Pulmonary perfusion imaging, although nonspecific, may provide the earliest clue for correct diagnosis of fat embolism, air embolism, contusion, or laceration. Furthermore, the possibility of perfusion abnormality due to these uncommon conditions must be remembered whenever trauma patients are evaluated for pulmonary thromboembolism with scintigraphy. Occasionally, liver or spleen scintigraphy may be the most appropriate procedure when penetrating chest trauma also involves these subdiaphragmatic organs.

  7. Drug Delivery to the Ischemic Brain

    PubMed Central

    Thompson, Brandon J.; Ronaldson, Patrick T.

    2014-01-01

    Cerebral ischemia occurs when blood flow to the brain is insufficient to meet metabolic demand. This can result from cerebral artery occlusion that interrupts blood flow, limits CNS supply of oxygen and glucose, and causes an infarction/ischemic stroke. Ischemia initiates a cascade of molecular events inneurons and cerebrovascular endothelial cells including energy depletion, dissipation of ion gradients, calcium overload, excitotoxicity, oxidative stress, and accumulation of ions and fluid. Blood-brain barrier (BBB) disruption is associated with cerebral ischemia and leads to vasogenic edema, a primary cause of stroke-associated mortality. To date, only a single drug has received US Food and Drug Administration (FDA) approval for acute ischemic stroke treatment, recombinant tissue plasminogen activator (rt-PA). While rt-PA therapy restores perfusion to ischemic brain, considerable tissue damage occurs when cerebral blood flow is re-established. Therefore, there is a critical need for novel therapeutic approaches that can “rescue” salvageable brain tissue and/or protect BBB integrity during ischemic stroke. One class of drugs that may enable neural cell rescue following cerebral ischemia/reperfusion injury is the HMG-CoA reductase inhibitors (i.e., statins). Understanding potential CNS drug delivery pathways for statins is critical to their utility in ischemic stroke. Here, we review molecular pathways associated with cerebral ischemia and novel approaches for delivering drugs to treat ischemic disease. Specifically, we discuss utility of endogenous BBB drug uptake transporters such as organic anion transporting polypeptides (OATPs/Oatps) and nanotechnology-based carriers for optimization of CNS drug delivery. Overall, this chapter highlights state-of-the-art technologies that may improve pharmacotherapy of cerebral ischemia. PMID:25307217

  8. Radionuclide salivary gland imaging

    SciTech Connect

    Mishkin, F.S.

    1981-10-01

    Salivary gland imaging with 99mTc as pertechnetate provides functional information concerning trapping and excretion of the parotid and submandibular glands. Anatomic information gained often adds little to clinical evaluation. On the other hand, functional information may detect subclinical involvement, which correlates well with biopsy of the minor labial salivary glands. Salivary gland abnormalities in systemic disease such as sarcoidosis, rheumatoid arthritis, lupus erythematosus, and other collagenvascular disorders may be detected before they result in the clinical manifestaions of Sjoegren's syndrome. Such glands, after initially demonstrating increased trapping in the acute phase, tend to have decreased trapping and failure to discharge pertechnetate in response to an appropriate physiologic stimulus. Increased uptake of gallium-67 citrate often accompanies these findings. Inflammatory parotitis can be suspected when increased perfusion is evident on radionuclide angiography with any agent. The ability of the salivary gland image to detect and categorize mass lesions, which result in focal areas of diminished activity such as tumors, cysts, and most other masses, is disappointing, while its ability to detect and categorize Warthin's tumor, which concentrates pertechnetate, is much more valuable, although not specific.

  9. Intracoronary Delivery of Mitochondria to the Ischemic Heart for Cardioprotection.

    PubMed

    Cowan, Douglas B; Yao, Rouan; Akurathi, Vamsidhar; Snay, Erin R; Thedsanamoorthy, Jerusha K; Zurakowski, David; Ericsson, Maria; Friehs, Ingeborg; Wu, Yaotang; Levitsky, Sidney; Del Nido, Pedro J; Packard, Alan B; McCully, James D

    2016-01-01

    We have previously shown that transplantation of autologously derived, respiration-competent mitochondria by direct injection into the heart following transient ischemia and reperfusion enhances cell viability and contractile function. To increase the therapeutic potential of this approach, we investigated whether exogenous mitochondria can be effectively delivered through the coronary vasculature to protect the ischemic myocardium and studied the fate of these transplanted organelles in the heart. Langendorff-perfused rabbit hearts were subjected to 30 minutes of ischemia and then reperfused for 10 minutes. Mitochondria were labeled with 18F-rhodamine 6G and iron oxide nanoparticles. The labeled mitochondria were either directly injected into the ischemic region or delivered by vascular perfusion through the coronary arteries at the onset of reperfusion. These hearts were used for positron emission tomography, microcomputed tomography, and magnetic resonance imaging with subsequent microscopic analyses of tissue sections to confirm the uptake and distribution of exogenous mitochondria. Injected mitochondria were localized near the site of delivery; while, vascular perfusion of mitochondria resulted in rapid and extensive dispersal throughout the heart. Both injected and perfused mitochondria were observed in interstitial spaces and were associated with blood vessels and cardiomyocytes. To determine the efficacy of vascular perfusion of mitochondria, an additional group of rabbit hearts were subjected to 30 minutes of regional ischemia and reperfused for 120 minutes. Immediately following regional ischemia, the hearts received unlabeled, autologous mitochondria delivered through the coronary arteries. Autologous mitochondria perfused through the coronary vasculature significantly decreased infarct size and significantly enhanced post-ischemic myocardial function. In conclusion, the delivery of mitochondria through the coronary arteries resulted in their rapid

  10. Intracoronary Delivery of Mitochondria to the Ischemic Heart for Cardioprotection

    PubMed Central

    Cowan, Douglas B.; Yao, Rouan; Akurathi, Vamsidhar; Snay, Erin R.; Thedsanamoorthy, Jerusha K.; Zurakowski, David; Ericsson, Maria; Friehs, Ingeborg; Wu, Yaotang; Levitsky, Sidney; del Nido, Pedro J.; Packard, Alan B.

    2016-01-01

    We have previously shown that transplantation of autologously derived, respiration-competent mitochondria by direct injection into the heart following transient ischemia and reperfusion enhances cell viability and contractile function. To increase the therapeutic potential of this approach, we investigated whether exogenous mitochondria can be effectively delivered through the coronary vasculature to protect the ischemic myocardium and studied the fate of these transplanted organelles in the heart. Langendorff-perfused rabbit hearts were subjected to 30 minutes of ischemia and then reperfused for 10 minutes. Mitochondria were labeled with 18F-rhodamine 6G and iron oxide nanoparticles. The labeled mitochondria were either directly injected into the ischemic region or delivered by vascular perfusion through the coronary arteries at the onset of reperfusion. These hearts were used for positron emission tomography, microcomputed tomography, and magnetic resonance imaging with subsequent microscopic analyses of tissue sections to confirm the uptake and distribution of exogenous mitochondria. Injected mitochondria were localized near the site of delivery; while, vascular perfusion of mitochondria resulted in rapid and extensive dispersal throughout the heart. Both injected and perfused mitochondria were observed in interstitial spaces and were associated with blood vessels and cardiomyocytes. To determine the efficacy of vascular perfusion of mitochondria, an additional group of rabbit hearts were subjected to 30 minutes of regional ischemia and reperfused for 120 minutes. Immediately following regional ischemia, the hearts received unlabeled, autologous mitochondria delivered through the coronary arteries. Autologous mitochondria perfused through the coronary vasculature significantly decreased infarct size and significantly enhanced post-ischemic myocardial function. In conclusion, the delivery of mitochondria through the coronary arteries resulted in their rapid

  11. Role of Extracranial Carotid Duplex and Computed Tomography Perfusion Scanning in Evaluating Perfusion Status of Pericarotid Stenting

    PubMed Central

    Lin, Chih-Ming; Chang, Yu-Jun; Liu, Chi-Kuang; Yu, Cheng-Sheng

    2016-01-01

    Carotid stenting is an effective treatment of choice in terms of treating ischemic stroke patients with concomitant carotid stenosis. Though computed tomography perfusion scan has been recognized as a standard tool to monitor/follow up this group of patients, not everyone could endure due to underlying medical illness. In contrast, carotid duplex is a noninvasive assessment tool and could track patient clinical condition in real time. In this study we found that “resistance index” of the carotid ultrasound could detect flow changes before and after the stenting procedure, thus having great capacity to replace the role of computed tomography perfusion exam. PMID:27051669

  12. Prognostic value of radionuclide exercise testing after myocardial infarction

    SciTech Connect

    Schocken, D.D.

    1984-08-01

    Abnormal systolic ventricular function and persistent ischemia are sensitive indicators of poor prognosis following myocardial infarction. The use of exercise improves the utility of both radionuclide ventriculography and myocardial perfusion scintigraphy in the identification of postinfarction patients at high risk of subsequent cardiac events. 51 references.

  13. Ischemic optic neuropathy.

    PubMed

    Athappilly, Geetha; Pelak, Victoria S; Mandava, Naresh; Bennett, Jeffrey L

    2008-10-01

    Ischemic optic neuropathy is the most frequent cause of vision loss in middle age. Clinical and laboratory research studies have begun to clarify the natural history, clinical presentation, diagnostic criteria and pathogenesis of various ischemic nerve injuries. As a result, physicians are acquiring new tools to aid in the diagnosis and potential treatment of ischemic nerve injury. The aim of this review is to examine recent data on anterior and posterior ischemic optic neuropathy and to provide a framework for physicians to manage and counsel affected individuals. PMID:18826805

  14. Hepatic Perfusion Therapy.

    PubMed

    Rajeev, Rahul; Gamblin, T Clark; Turaga, Kiran K

    2016-04-01

    Isolated hepatic perfusion uses the unique vascular supply of hepatic malignancies to deliver cytotoxic chemotherapy. The procedure involves vascular isolation of the liver and delivery of chemotherapy via the hepatic artery and extraction from retrohepatic vena cava. Benefits of hepatic perfusion have been observed in hepatic metastases of ocular melanoma and colorectal cancer and primary hepatocellular carcinoma. Percutaneous and prophylactic perfusions are avenues of ongoing research.

  15. Cerebrospinal fluid may mediate CNS ischemic injury

    PubMed Central

    Wang, Yanming F; Gwathmey, Judith K; Zhang, Guorong; Soriano, Sulpicio G; He, Shunli; Wang, Yanguang

    2005-01-01

    Background The central nervous system (CNS) is extremely vulnerable to ischemic injury. The details underlying this susceptibility are not completely understood. Since the CNS is surrounded by cerebrospinal fluid (CSF) that contains a low concentration of plasma protein, we examined the effect of changing the CSF in the evolution of CNS injury during ischemic insult. Methods Lumbar spinal cord ischemia was induced in rabbits by cross-clamping the descending abdominal aorta for 1 h, 2 h or 3 h followed by 7 d of reperfusion. Prior to ischemia, rabbits were subjected to the following procedures; 1) CSF depletion, 2) CSF replenishment at 0 mmHg intracranial pressure (ICP), and 3) replacement of CSF with 8% albumin- or 1% gelatin-modified artificial CSF, respectively. Motor function of the hind limbs and histopathological changes of the spinal cord were scored. Post-ischemic microcirculation of the spinal cord was visualized by fluorescein isothiocyanate (FITC) albumin. Results The severity of histopathological damage paralleled the neurological deficit scores. Paraplegia and associated histopathological changes were accompanied by a clear post-ischemic deficit in blood perfusion. Spinal cord ischemia for 1 h resulted in permanent paraplegia in the control group. Depletion of the CSF significantly prevented paraplegia. CSF replenishment with the ICP reduced to 0 mmHg, did not prevent paraplegia. Replacement of CSF with albumin- or gelatin-modified artificial CSF prevented paraplegia in rabbits even when the ICP was maintained at 10–15 mmHg. Conclusion We conclude that the presence of normal CSF may contribute to the vulnerability of the spinal cord to ischemic injury. Depletion of the CSF or replacement of the CSF with an albumin- or gelatin-modified artificial CSF can be neuroprotective. PMID:16174300

  16. Transient Ischemic Attack

    MedlinePlus

    Transient Ischemic Attack TIA , or transient ischemic attack, is a "mini stroke" that occurs when a blood clot blocks an artery for a short time. The only ... TIA is that with TIA the blockage is transient (temporary). TIA symptoms occur rapidly and last a ...

  17. Fast nonlinear regression method for CT brain perfusion analysis.

    PubMed

    Bennink, Edwin; Oosterbroek, Jaap; Kudo, Kohsuke; Viergever, Max A; Velthuis, Birgitta K; de Jong, Hugo W A M

    2016-04-01

    Although computed tomography (CT) perfusion (CTP) imaging enables rapid diagnosis and prognosis of ischemic stroke, current CTP analysis methods have several shortcomings. We propose a fast nonlinear regression method with a box-shaped model (boxNLR) that has important advantages over the current state-of-the-art method, block-circulant singular value decomposition (bSVD). These advantages include improved robustness to attenuation curve truncation, extensibility, and unified estimation of perfusion parameters. The method is compared with bSVD and with a commercial SVD-based method. The three methods were quantitatively evaluated by means of a digital perfusion phantom, described by Kudo et al. and qualitatively with the aid of 50 clinical CTP scans. All three methods yielded high Pearson correlation coefficients ([Formula: see text]) with the ground truth in the phantom. The boxNLR perfusion maps of the clinical scans showed higher correlation with bSVD than the perfusion maps from the commercial method. Furthermore, it was shown that boxNLR estimates are robust to noise, truncation, and tracer delay. The proposed method provides a fast and reliable way of estimating perfusion parameters from CTP scans. This suggests it could be a viable alternative to current commercial and academic methods. PMID:27413770

  18. CT perfusion: principles, applications, and problems

    NASA Astrophysics Data System (ADS)

    Lee, Ting-Yim

    2004-10-01

    The fast scanning speed of current slip-ring CT scanners has enabled the development of perfusion imaging techniques with intravenous injection of contrast medium. In a typical CT perfusion study, contrast medium is injected and rapid scanning at a frequency of 1-2 Hz is used to monitor the first circulation of the injected contrast medium through a 1-2 cm thick slab of tissue. From the acquired time-series of CT images, arteries can be identified within the tissue slab to derive the arterial contrast concentration curve, Ca(t) while each individual voxel produces a tissue residue curve, Q(t) for the corresponding tissue region. Deconvolution between the measured Ca(t) and Q(t) leads to the determination of cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) in brain studies. In this presentation, an important application of CT perfusion in acute stroke studies - the identification of the ischemic penumbra via the CBF/CBV mismatch and factors affecting the quantitative accuracy of deconvolution, including partial volume averaging, arterial delay and dispersion are discussed.

  19. Hyperpolarized 129Xe magnetic resonance imaging of a rat model of transient Ischemic Stroke

    NASA Astrophysics Data System (ADS)

    Walvick, Ronn P.; Bastan, Birgul; Reno, Austin; Mansour, Joey; Sun, Yanping; Zhou, Xin; Mazzani, Mary; Fisher, Marc; Sotak, Christopher H.; Albert, Mitchell S.

    2009-02-01

    Ischemic stroke accounts for nearly 80% of all stroke cases. Although proton diffusion and perfusion magnetic resonance imaging (MRI) are the gold standards in ischemic stroke diagnostics, the use of hyperpolarized 129Xe MRI has a potential role to contribute to the diagnostic picture. The highly lipophilic hyperpolarized 129Xe can be non-invasively delivered via inhalation into the lungs where it is dissolved into the blood and delivered to other organs such as the brain. As such, we expect hyperpolarized 129Xe to act as a perfusion tracer which will result in a signal deficit in areas of blood deprived tissue. In this work, we present imaging results from an animal model of transient ischemic stroke characterized through 129Xe MRI. In this model, a suture is used to occlude the middle cerebral artery (MCA) in the rat brain, thus causing an ischemic event. After a period of MCA occlusion, the suture can then be removed to reperfuse the ischemic area. During the ischemic phase of the stroke, a signal void was observed in the MCA territory; which was subsequently restored by normal 129Xe MRI signal once perfusion was reinstated. Further, a higher resolution one-dimensional chemical shift image shows a sharp signal drop in the area of ischemia. Validation of ischemic damage was shown through both proton diffusion-weighted MRI (DWI) and by 2,3,5-triphenyltetrazoliumchloride (TTC) staining. The results show the potential of 129Xe to act as a perfusion tracer; information that may add to the diagnostic and prognostic utility of the clinical picture of stroke.

  20. Gallbladder radionuclide scan

    MedlinePlus

    Radionuclide - gallbladder; Gallbladder scan; Biliary scan; Cholescintigraphy: HIDA; Hepatobiliary nuclear imaging scan ... small amount of morphine. This can help the radionuclide get into the gallbladder. The morphine may cause ...

  1. In vivo characterization of ischemic small intestine using bioimpedance measurements.

    PubMed

    Strand-Amundsen, R J; Tronstad, C; Kalvøy, H; Gundersen, Y; Krohn, C D; Aasen, A O; Holhjem, L; Reims, H M; Martinsen, Ø G; Høgetveit, J O; Ruud, T E; Tønnessen, T I

    2016-02-01

    The standard clinical method for the assessment of viability in ischemic small intestine is still visual inspection and palpation. This method is non-specific and unreliable, and requires a high level of clinical experience. Consequently, viable tissue might be removed, or irreversibly damaged tissue might be left in the body, which may both slow down patient recovery. Impedance spectroscopy has been used to measure changes in electrical parameters during ischemia in various tissues. The physical changes in the tissue at the cellular and structural levels after the onset of ischemia lead to time-variant changes in the electrical properties. We aimed to investigate the use of bioimpedance measurement to assess if the tissue is ischemic, and to assess the ischemic time duration. Measurements were performed on pigs (n = 7) using a novel two-electrode setup, with a Solartron 1260/1294 impedance gain-phase analyser. After induction of anaesthesia, an ischemic model with warm, full mesenteric arterial and venous occlusion on 30 cm of the jejunum was implemented. Electrodes were placed on the serosal surface of the ischemic jejunum, applying a constant voltage, and measuring the resulting electrical admittance. As a control, measurements were done on a fully perfused part of the jejunum in the same porcine model. The changes in tan δ (dielectric parameter), measured within a 6 h period of warm, full mesenteric occlusion ischemia in seven pigs, correlates with the onset and duration of ischemia. Tan δ measured in the ischemic part of the jejunum differed significantly from the control tissue, allowing us to determine if the tissue was ischemic or not (P < 0.0001, F = (1,75.13) 188.19). We also found that we could use tan δ to predict ischemic duration. This opens up the possibility of real-time monitoring and assessment of the presence and duration of small intestinal ischemia. PMID:26805916

  2. Radionuclide Ventriculography or Radionuclide Angiography (MUGA Scan)

    MedlinePlus

    ... Attack Heart Failure Myocardial Perfusion Imaging (MPI) Single Photon Emission Computed Tomography (SPECT) Positron Emission Tomography (PET) ... today ! Popular Articles 1 Understanding Blood Pressure Readings 2 Sodium and Salt 3 Low Blood Pressure 4 ...

  3. Radionuclide deposition control

    DOEpatents

    Brehm, William F.; McGuire, Joseph C.

    1980-01-01

    The deposition of radionuclides manganese-54, cobalt-58 and cobalt-60 from liquid sodium coolant is controlled by providing surfaces of nickel or high nickel alloys to extract the radionuclides from the liquid sodium, and by providing surfaces of tungsten, molybdenum or tantalum to prevent or retard radionuclide deposition.

  4. Perioperative ischemic injury after coronary bypass graft surgery

    SciTech Connect

    Li, W.; Hanelin, L.G.; Riggins, R.C.; Agnew, R.C.; Annest, L.S.; Anderson, R.P.

    1985-07-01

    Two hundred twelve patients who underwent isolated coronary bypass graft surgery were prospectively evaluated for perioperative ischemic injury. All patients underwent preoperative and postoperative testing with technetium 99m pyrophosphate first-pass ventriculography combined with myocardial uptake scans, 12-lead electrocardiography, and serial creatinine phosphokinase MB determination. Fifteen percent of the patients had ischemic injury with at least two test results positive, but only 4 percent had positive results of all three tests. No single test proved adequate. Enzyme levels were highly sensitive and had value as a screening test. The electrocardiogram was specific but only moderately sensitive. The single best test was the radionuclide scan with good sensitivity and no false-positive results. All three tests are required to rigorously diagnose ischemic injury.

  5. Quantitative radionuclide angiocardiography

    SciTech Connect

    Scholz, P.M.; Rerych, S.K.; Moran, J.F.; Newman, G.E.; Douglas, J.M.; Sabiston, D.C. Jr.; Jones, R.H.

    1980-01-01

    This study introduces a new method for calculating actual left ventricular volumes and cardiac output from data recorded during a single transit of a radionuclide bolus through the heart, and describes in detail current radionuclide angiocardiography methodology. A group of 64 healthy adults with a wide age range were studied to define the normal range of hemodynamic parameters determined by the technique. Radionuclide angiocardiograms were performed in patients undergoing cardiac catherization to validate the measurements. In 33 patients studied by both techniques on the same day, a close correlation was documented for measurement of ejection fraction and end-diastolic volume. To validate the method of volumetric cardiac output calcuation, 33 simultaneous radionuclide and indocyanine green dye determinations of cardiac output were performed in 18 normal young adults. These independent comparisons of radionuclide measurements with two separate methods document that initial transit radionuclide angiocardiography accurately assesses left ventricular function.

  6. Cardiac Magnetic Resonance Imaging in Ischemic Heart Disease

    PubMed Central

    Florian, A.; Jurcut, R.; Ginghina, C.; Bogaert, J.

    2011-01-01

    Cardiac magnetic resonance imaging (MRI) has emerged as a prime player in the clinical and preclinical detection of ischemic heart disease (IHD) as well in the prognosis assessment by offering a comprehensive approach for all spectrums of coronary artery disease (CAD) patients. The aim of this review is to provide the reader a state–of–the art on how the newest cardiac MRI techniques can be used to study IHD patients. In patients with suspected/stable CAD, functional and perfusion imaging both at rest and during vasodilatatory stress (adenosine, dypiridamole)/dobutamine stress can accurately depict ischemic myocardium secondary to significant coronary artery stenosis. In patients with acute MI, MRI is a robust tool for differentiating and sizing the jeopardized and the infarcted myocardium by using a combination of functional, edema, perfusion and Gd contrast imaging. Moreover, important prognostic factors like myocardial salvage, the presence of microvascular obstruction (MVO), post reperfusion myocardial hemorrhage, RV involvement and infarct related complications can be assessed in the same examination. In patients with chronic ischemic cardiomyopathy, the role of the MRI extends from diagnosis by means of Gadolinium contrast scar imaging to therapy and prognosis by functional assessment and viability testing with rest and dobutamine stress imaging. In all the circumstances mentioned, MRI derived information has been proven valuable in every day clinical decision making and prognosis assessment. Thus, MRI is becoming more and more an accepted alternative to other imaging modalities both in the acute and chronic setting. PMID:22514564

  7. Ex vivo lung perfusion.

    PubMed

    Reeb, Jeremie; Cypel, Marcelo

    2016-03-01

    Lung transplantation is an established life-saving therapy for patients with end-stage lung disease. Unfortunately, greater success in lung transplantation is hindered by a shortage of lung donors and the relatively poor early-, mid-, and long-term outcomes associated with severe primary graft dysfunction. Ex vivo lung perfusion has emerged as a modern preservation technique that allows for a more accurate lung assessment and improvement in lung quality. This review outlines the: (i) rationale behind the method; (ii) techniques and protocols; (iii) Toronto ex vivo lung perfusion method; (iv) devices available; and (v) clinical experience worldwide. We also highlight the potential of ex vivo lung perfusion in leading a new era of lung preservation. PMID:26700566

  8. Isolated lung perfusion.

    PubMed

    Cypel, Marcelo; Keshavjee, Shaf

    2012-01-01

    Isolated lung perfusion (ILP) has been historically used as a method to study basic lung physiologic concepts using animal models. More recently, ILP has been applied in lung transplantation and thoracic oncology. In lung transplantation, ILP has been used to assess physiological integrity of donor lungs after the organ is removed from the donor. This procedure is called Ex vivo Lung Perfusion (EVLP), and it has also been proposed as a method for active treatment and repair of injured unsuitable donor organs ex vivo. In oncology, ILP is an attractive method to deliver high dose chemotherapy to treat pulmonary metastatic disease. Since the lung vasculature is isolated in vivo, this technique is called in vivo lung perfusion (IVLP). This review will focus on the rationale, technical aspects, experimental and clinical experience of EVLP and IVLP. A perspective on the future use of these techniques is described. PMID:22202033

  9. Myocardial perfusion echocardiography and coronary microvascular dysfunction

    PubMed Central

    Barletta, Giuseppe; Del Bene, Maria Riccarda

    2015-01-01

    Our understanding of coronary syndromes has evolved in the last two decades out of the obstructive atherosclerosis of epicardial coronary arteries paradigm to include anatomo-functional abnormalities of coronary microcirculation. No current diagnostic technique allows direct visualization of coronary microcirculation, but functional assessments of this circulation are possible. This represents a challenge in cardiology. Myocardial contrast echocardiography (MCE) was a breakthrough in echocardiography several years ago that claimed the capability to detect myocardial perfusion abnormalities and quantify coronary blood flow. Research demonstrated that the integration of quantitative MCE and fractional flow reserve improved the definition of ischemic burden and the relative contribution of collaterals in non-critical coronary stenosis. MCE identified no-reflow and low-flow within and around myocardial infarction, respectively, and predicted the potential functional recovery of stunned myocardium using appropriate interventions. MCE exhibited diagnostic performances that were comparable to positron emission tomography in microvascular reserve and microvascular dysfunction in angina patients. Overall, MCE improved echocardiographic evaluations of ischemic heart disease in daily clinical practice, but the approval of regulatory authorities is lacking. PMID:26730291

  10. Preparation of Radiopharmaceuticals Labeled with Metal Radionuclides

    SciTech Connect

    Welch, M.J.

    2012-02-16

    The overall goal of this project was to develop methods for the production of metal-based radionuclides, to develop metal-based radiopharmaceuticals and in a limited number of cases, to translate these agents to the clinical situation. Initial work concentrated on the application of the radionuclides of Cu, Cu-60, Cu-61 and Cu-64, as well as application of Ga-68 radiopharmaceuticals. Initially Cu-64 was produced at the Missouri University Research Reactor and experiments carried out at Washington University. A limited number of studies were carried out utilizing Cu-62, a generator produced radionuclide produced by Mallinckrodt Inc. (now Covidien). In these studies, copper-62-labeled pyruvaldehyde Bis(N{sup 4}-methylthiosemicarbazonato)-copper(II) was studied as an agent for cerebral myocardial perfusion. A remote system for the production of this radiopharmaceutical was developed and a limited number of patient studies carried out with this agent. Various other copper radiopharmaceuticals were investigated, these included copper labeled blood imaging agents as well as Cu-64 labeled antibodies. Cu-64 labeled antibodies targeting colon cancer were translated to the human situation. Cu-64 was also used to label peptides (Cu-64 octriatide) and this is one of the first applications of a peptide radiolabeled with a positron emitting metal radionuclide. Investigations were then pursued on the preparation of the copper radionuclides on a small biomedical cyclotron. A system for the production of high specific activity Cu-64 was developed and initially the Cu-64 was utilized to study the hypoxic imaging agent Cu-64 ATSM. Utilizing the same target system, other positron emitting metal radionuclides were produced, these were Y-86 and Ga-66. Radiopharmaceuticals were labeled utilizing both of these radionuclides. Many studies were carried out in animal models on the uptake of Cu-ATSM in hypoxic tissue. The hypothesis is that Cu-ATSM retention in vivo is dependent upon the

  11. Effect of Dipyridamole Injected for Myocardial Perfusion Imaging on Blood Glucose Concentration; A Preliminary Study

    PubMed Central

    Arabi, Mohsen; Akhavein, Alireza; Seyedabadi, Mohammad; Eftekhari, Mansooreh; Javadi, Hamid; Nabipour, Iraj; Assadi, Majid

    2016-01-01

    Introduction Dipyridamole inhibits adenosine reuptake and increases cyclic Adenosine Monophosphate (cAMP) levels in platelets, erythrocytes and endothelial cells, all of which influence blood glucose. Acute hyperglycaemia reduces endothelium-dependent vasodilation and suppresses coronary microcirculation; which, in theory, can alter the outcome of a radionuclide scan. Aim The present study was conducted with the aim to investigate the changes in blood glucose level of patients receiving dipyridamole for cardiac scan. Materials and Methods A total of 293 patients (85 men and 208 women, age: 60.59±10.43 years) were included in the study. Fasting Blood Glucose (FBG) was measured before and 8 min after dipyridamole (0.568 mg/kg) injection during myocardial perfusion imaging. The data in different groups were analysed by paired t-test. Results There was not a significant difference between first (106.89 ± 19.21mg/dL) and second (107.98 ± 17.57 mg/dL) FBG measurements (p= 0.293). However, when the patients were grouped based on the quartiles of first measurement, there was an increase in FBG following dipyridamole injection in the first quartile (mean difference: 7.15±21.27 mg/dL, p<0.01); in contrast, FBG levels showed a significant decrease after dipyridamole administration in the 4th quartile (mean difference: -9.53±18.20 mg/dL, p<0.001). The differences in 2nd and 3rd quartiles were negligible. The patients were divided into normal, ischemic and fixed lesions based on the outcome of scans, then the possible correlation of dipyridamole-induced FBG alteration and scan results were investigated. There were no significant difference between the FBG values before and after dipyridamole injection and the final outcome of scan. Conclusion The effects of dipyridamole on blood glucose highly depend on the initial blood glucose level. PMID:27656528

  12. Ischemic Nerve Block.

    ERIC Educational Resources Information Center

    Williams, Ian D.

    This experiment investigated the capability for movement and muscle spindle function at successive stages during the development of ischemic nerve block (INB) by pressure cuff. Two male subjects were observed under six randomly ordered conditions. The duration of index finger oscillation to exhaustion, paced at 1.2Hz., was observed on separate…

  13. Evaluation of ischemic heart disease and viability by cardiac MRI.

    PubMed

    Bhatia, Mona

    2014-01-01

    In ischemic heart disease, cardiac MRI, besides being the gold standard for evaluation of quantitative ventricular function, enables evaluation of myocardial wall thickness, T2-weighted imaging for myocardial edema and infarct quantification and transmurality. Delayed hyperenhancement sequences are highly predictive of scar formation, being associated with myocyte necrosis. The extent and transmurality of delayed hyperenhancement has prognostic implications and is inversely proportional to the degree of functional recovery after acute myocardial infarction. A greater transmural extent of infarction (eg, hyperenhancement involving >50% of the wall thickness) can predict regions that are less likely to improve in function after therapy. The ultimate focus of MRI in ischemic heart disease is in diagnosis, quantification of myocardium at risk, salvageable myocardium, perfusion defects and differentiation of viable myocardium from non viable myocardium to enable prognostication.

  14. Automated core-penumbra quantification in neonatal ischemic brain injury.

    PubMed

    Ghosh, Nirmalya; Yuan, Xiangpeng; Turenius, Christine I; Tone, Beatriz; Ambadipudi, Kamalakar; Snyder, Evan Y; Obenaus, Andre; Ashwal, Stephen

    2012-12-01

    Neonatal hypoxic-ischemic brain injury (HII) and arterial ischemic stroke (AIS) result in irreversibly injured (core) and salvageable (penumbral) tissue regions. Identification and reliable quantification of salvageable tissue is pivotal to any effective and safe intervention. Magnetic resonance imaging (MRI) is the current standard to distinguish core from penumbra using diffusion-perfusion mismatch (DPM). However, subtle MR signal variations between core-penumbral regions make their visual delineation difficult. We hypothesized that computational analysis of MRI data provides a more accurate assessment of core and penumbral tissue evolution in HII/AIS. We used two neonatal rat-pup models of HII/AIS (unilateral and global hypoxic-ischemia) and clinical data sets from neonates with AIS to test our noninvasive, automated computational approach, Hierarchical Region Splitting (HRS), to detect and quantify ischemic core-penumbra using only a single MRI modality (T2- or diffusion-weighted imaging, T2WI/DWI). We also validated our approach by comparing core-penumbral images (from HRS) to DPM with immunohistochemical validation of HII tissues. Our translational and clinical data results showed that HRS could accurately and reliably distinguish the ischemic core from penumbra and their spatiotemporal evolution, which may aid in the vetting and execution of effective therapeutic interventions as well as patient selection.

  15. How to Perfuse: Concepts of Cerebral Protection during Arch Replacement

    PubMed Central

    Habertheuer, Andreas; Wiedemann, Dominik; Kocher, Alfred; Laufer, Guenther; Vallabhajosyula, Prashanth

    2015-01-01

    Arch surgery remains undoubtedly among the most technically and strategically challenging endeavors in cardiovascular surgery. Surgical interventions of thoracic aneurysms involving the aortic arch require complete circulatory arrest in deep hypothermia (DHCA) or elaborate cerebral perfusion strategies with varying degrees of hypothermia to achieve satisfactory protection of the brain from ischemic insults, that is, unilateral/bilateral antegrade cerebral perfusion (ACP) and retrograde cerebral perfusion (RCP). Despite sophisticated and increasingly individualized surgical approaches for complex aortic pathologies, there remains a lack of consensus regarding the optimal method of cerebral protection and circulatory management during the time of arch exclusion. Many recent studies argue in favor of ACP with various degrees of hypothermic arrest during arch reconstruction and its advantages have been widely demonstrated. In fact ACP with more moderate degrees of hypothermia represents a paradigm shift in the cardiac surgery community and is widely adopted as an emergent strategy; however, many centers continue to report good results using other perfusion strategies. Amidst this important discussion we review currently available surgical strategies of cerebral protection management and compare the results of recent European multicenter and single-center data. PMID:26713319

  16. Recombinant human erythropoietin stimulates angiogenesis and healing of ischemic skin wounds.

    PubMed

    Buemi, Michele; Galeano, Mariarosaria; Sturiale, Alessio; Ientile, Riccardo; Crisafulli, Costantino; Parisi, Alessandra; Catania, MariaAntonietta; Calapai, Gioacchino; Impalà, Patrizia; Aloisi, Carmela; Squadrito, Francesco; Altavilla, Domenica; Bitto, Alessandra; Tuccari, Giovanni; Frisina, Nicola

    2004-08-01

    Wound healing in ischemic tissues such as flap margins due to inadequate blood supply is still a source of considerable morbidity in surgical practice. Adequate tissue perfusion is particularly important in wound healing. We investigated the effects of recombinant human erythropoietin (rHuEPO) on wound healing in an ischemic skin wound model. Sixty-three Sprague-Dawley rats were used. Normal incisional wound and H-shaped double flaps were used as the wound models. Animals were treated with rHuEPO (400 IU/kg) or its vehicle. Rats were killed on different days (3, 5, and 10 days after skin injury) and the wounded skin tissues were used for immunohistochemistry and for analysis of vascular endothelial growth factor content and collagen content. Tissue transglutaminase immunostaining of histological specimens was used as a vascular marker to determine the level of microvessel density. The results showed a higher level of vascular endothelial growth factor protein and an increased microvessel density in ischemic wounds with rHuEPO treatment than the normal incisional wounds and ischemic control wounds. Collagen content was higher in the incisional wounds and in the ischemic wounds with rHuEPO treatment compared with the ischemic control wounds. Our results suggest that erythropoietin may be an effective therapeutic approach in improving healing in ischemic skin wounds.

  17. Radionuclides in US coals

    SciTech Connect

    Bisselle, C. A.; Brown, R. D.

    1984-03-01

    The current state of knowledge with respect to radionuclide concentrations in US coals is discussed. Emphasis is placed on the levels of uranium in coal (and lignite) which are considered to represent a concern resulting from coal combustion; areas of the US where such levels have been found; and possible origins of high radionuclide levels in coal. The report reviews relevant studies and presents new data derived from a computerized search of radionuclide content in about 4000 coal samples collected throughout the coterminous US. 103 references, 5 figures, 5 tables.

  18. Astrocyte-mediated ischemic tolerance.

    PubMed

    Hirayama, Yuri; Ikeda-Matsuo, Yuri; Notomi, Shoji; Enaida, Hiroshi; Kinouchi, Hiroyuki; Koizumi, Schuichi

    2015-03-01

    Preconditioning (PC) using a preceding sublethal ischemic insult is an attractive strategy for protecting neurons by inducing ischemic tolerance in the brain. Although the underlying molecular mechanisms have been extensively studied, almost all studies have focused on neurons. Here, using a middle cerebral artery occlusion model in mice, we show that astrocytes play an essential role in the induction of brain ischemic tolerance. PC caused activation of glial cells without producing any noticeable brain damage. The spatiotemporal pattern of astrocytic, but not microglial, activation correlated well with that of ischemic tolerance. Interestingly, such activation in astrocytes lasted at least 8 weeks. Importantly, inhibiting astrocytes with fluorocitrate abolished the induction of ischemic tolerance. To investigate the underlying mechanisms, we focused on the P2X7 receptor as a key molecule in astrocyte-mediated ischemic tolerance. P2X7 receptors were dramatically upregulated in activated astrocytes. PC-induced ischemic tolerance was abolished in P2X7 receptor knock-out mice. Moreover, our results suggest that hypoxia-inducible factor-1α, a well known mediator of ischemic tolerance, is involved in P2X7 receptor-mediated ischemic tolerance. Unlike previous reports focusing on neuron-based mechanisms, our results show that astrocytes play indispensable roles in inducing ischemic tolerance, and that upregulation of P2X7 receptors in astrocytes is essential. PMID:25740510

  19. Use of diffusion and perfusion magnetic resonance imaging as a tool in acute stroke clinical trials

    PubMed Central

    Warach, Steven

    2001-01-01

    In light of the slow progress in developing effective therapies for ischemic stroke, magnetic resonance imaging techniques have emerged as new tools in stroke clinical trials. Rapid imaging with magnetic resonance imaging, diffusion weighted imaging, perfusion imaging and angiography are being incorporated into phase II and phase III stroke trials to optimize patient selection based on positive imaging diagnosis of the ischemic pathophysiology specifically related to a drug's mechanism of action and as a direct biomarker of the effect of a treatment's effect on the brain. PMID:11806771

  20. Association between retinal hemorrhagic pattern and macular perfusion status in eyes with acute branch retinal vein occlusion

    PubMed Central

    Muraoka, Yuki; Uji, Akihito; Tsujikawa, Akitaka; Murakami, Tomoaki; Ooto, Sotaro; Suzuma, Kiyoshi; Takahashi, Ayako; Iida, Yuto; Miwa, Yuko; Hata, Masayuki; Yoshimura, Nagahisa

    2016-01-01

    This prospective study included 63 eyes with acute branch retinal vein occlusion (BRVO) to evaluate the retinal hemorrhagic patterns at the posterior poles and explore their clinical relevance in macular perfusion differentiation. Retinal hemorrhagic patterns and macular perfusion status were evaluated via fundus photography and fluorescein angiography, respectively. Macular perfusion was judged as nonischemic in 30, ischemic in 28, and undeterminable in 5 among the 63 eyes. Predominant hemorrhagic patterns were flame-shaped in 39 (67.2%) and non-flame-shaped in 19 (32.8%) eyes. All 39 eyes with a flame-shaped hemorrhage showed a nonischemic macula. Of the 19 eyes classified as having a non-flame-shaped hemorrhage, 13 (68.4%) had an ischemic macula and 6 (31.6%) had a nonischemic macula (P < 0.001). Parallelism in eyes with a flame-shaped hemorrhage was higher than in those with a non-flame-shaped hemorrhage (P < 0.001), and in those with a nonischemic macula versus those with an ischemic macula (P < 0.001). The area under the curve for parallelism was 0.975 (P < 0.001), suggesting an accurate diagnostic parameter for macular perfusion differentiation. In conclusion, we objectively evaluated retinal hemorrhagic patterns at the posterior pole in BRVO using the parallelism method, which was useful in differentiating macular perfusion status. PMID:27334338

  1. Use of Doppler ultrasound in the management of uteroplacental perfusion during cardiopulmonary bypass in pregnancy.

    PubMed

    Mandel, D C; Pryde, P G; Shah, D M; Iruretagoyena, J I

    2016-08-01

    Cardiopulmonary bypass, the extreme of non-obstetric surgery during pregnancy, presents unique challenges to minimize maternal and fetal risk. We present our experience with a woman who was diagnosed with a left atrial myxoma following an ischemic cerebrovascular accident. We discuss clinical management specific to cardiopulmonary bypass during pregnancy and delivery in the context of a multidisciplinary team approach. We recommend using intermittent Doppler ultrasound as a non-invasive real-time assessment of uteroplacental perfusion during non-obstetric surgery in pregnancy. Monitoring of perfusion facilitates active feedback for appropriate in utero resuscitation in these cases. PMID:27021885

  2. Radionuclide Behavior in Containments.

    2000-02-14

    MATADOR analyzes the transport and deposition of radionuclides as vapor or aerosol through Light Water Reactor (LWR) containments during severe accidents and calculates environmental release fractions of radionuclides as a function of time. It is intended for use in system risk studies. The principal output is information on the timing and magnitude of radionuclide releases to the environment as a result of severely degraded core accidents. MATADOR considers the transport of radionuclides through the containmentmore » and their removal by natural deposition and the operation of engineered safety systems such as sprays. Input data on the source term from the primary system, the containment geometry, and thermal-hydraulic conditions are required.« less

  3. Radionuclides in Diagnosis.

    ERIC Educational Resources Information Center

    Williams, E. D.

    1989-01-01

    Discussed is a radionuclide imaging technique, including the gamma camera, image analysis computer, radiopharmaceuticals, and positron emission tomography. Several pictures showing the use of this technique are presented. (YP)

  4. Acute ischemic stroke update.

    PubMed

    Baldwin, Kathleen; Orr, Sean; Briand, Mary; Piazza, Carolyn; Veydt, Annita; McCoy, Stacey

    2010-05-01

    Stroke is the third most common cause of death in the United States and is the number one cause of long-term disability. Legislative mandates, largely the result of the American Heart Association, American Stroke Association, and Brain Attack Coalition working cooperatively, have resulted in nationwide standardization of care for patients who experience a stroke. Transport to a skilled facility that can provide optimal care, including immediate treatment to halt or reverse the damage caused by stroke, must occur swiftly. Admission to a certified stroke center is recommended for improving outcomes. Most strokes are ischemic in nature. Acute ischemic stroke is a heterogeneous group of vascular diseases, which makes targeted treatment challenging. To provide a thorough review of the literature since the 2007 acute ischemic stroke guidelines were developed, we performed a search of the MEDLINE database (January 1, 2004-July 1, 2009) for relevant English-language studies. Results (through July 1, 2009) from clinical trials included in the Internet Stroke Center registry were also accessed. Results from several pivotal studies have contributed to our knowledge of stroke. Additional data support the efficacy and safety of intravenous alteplase, the standard of care for acute ischemic stroke since 1995. Due to these study results, the American Stroke Association changed its recommendation to extend the time window for administration of intravenous alteplase from within 3 hours to 4.5 hours of symptom onset; this recommendation enables many more patients to receive the drug. Other findings included clinically useful biomarkers, the role of inflammation and infection, an expanded role for placement of intracranial stents, a reduced role for urgent carotid endarterectomy, alternative treatments for large-vessel disease, identification of nontraditional risk factors, including risk factors for women, and newly published pediatric stroke guidelines. In addition, new devices for

  5. Method and apparatus for separating radionuclides from non-radionuclides

    DOEpatents

    Harp, Richard J.

    1990-01-01

    In an apparatus for separating radionuclides from non-radionuclides in a mixture of nuclear waste, a vessel is provided wherein the mixture is heated to a temperature greater than the temperature of vaporization for the non-radionuclides but less than the temperature of vaporization for the radionuclides. Consequently the non-radionuclides are vaporized while the non-radionuclides remain the solid or liquid state. The non-radionuclide vapors are withdrawn from the vessel and condensed to produce a flow of condensate. When this flow decreases the heat is reduced to prevent temperature spikes which might otherwise vaporize the radionuclides. The vessel is removed and capped with the radioactive components of the apparatus and multiple batches of the radionuclide residue disposed therein. Thus the vessel ultimately provides a burial vehicle for all of the radioactive components of the process.

  6. Simultaneous technetium-99m MIBI angiography and myocardial perfusion imaging

    SciTech Connect

    Baillet, G.Y.; Mena, I.G.; Kuperus, J.H.; Robertson, J.M.; French, W.J.

    1989-01-01

    Resting first-pass radionuclide angiography (FPRNA) was performed with the myocardial perfusion agent technetium-99m MIBI. In 27 patients, it was compared with technetium-99m diethylenetriamine pentaacetic acid FPRNA. A significant correlation was present in left (r = 0.93, p less than 0.001) as well as right (r = 0.92, p less than 0.001) ventricular ejection fraction measured with both radiopharmaceuticals. In 13 patients, MIBI derived segmental wall motion was compared with contrast ventriculography. A high correlation was present (p less than 0.001), and qualitative agreement was found in 38/52 segments. In 19 patients with myocardial infarction a significant correlation was present between MIBI segmental wall motion and perfusion scores (p less than 0.001). In ten patients with a history of myocardial infarction, 18 myocardial segments demonstrated diseased coronary vessels and impaired wall motion at contrast angiography. These segments were all identified by the MIBI wall motion and perfusion study. We conclude that MIBI is a promising agent for simultaneous evaluation of cardiac function and myocardial perfusion at rest.

  7. Pilocarpine-Induced Status Epilepticus in Rats Involves Ischemic and Excitotoxic Mechanisms

    PubMed Central

    Fabene, Paolo Francesco; Merigo, Flavia; Galiè, Mirco; Benati, Donatella; Bernardi, Paolo; Farace, Paolo; Nicolato, Elena; Marzola, Pasquina; Sbarbati, Andrea

    2007-01-01

    The neuron loss characteristic of hippocampal sclerosis in temporal lobe epilepsy patients is thought to be the result of excitotoxic, rather than ischemic, injury. In this study, we assessed changes in vascular structure, gene expression, and the time course of neuronal degeneration in the cerebral cortex during the acute period after onset of pilocarpine-induced status epilepticus (SE). Immediately after 2 hr SE, the subgranular layers of somatosensory cortex exhibited a reduced vascular perfusion indicative of ischemia, whereas the immediately adjacent supragranular layers exhibited increased perfusion. Subgranular layers exhibited necrotic pathology, whereas the supergranular layers were characterized by a delayed (24 h after SE) degeneration apparently via programmed cell death. These results indicate that both excitotoxic and ischemic injuries occur during pilocarpine-induced SE. Both of these degenerative pathways, as well as the widespread and severe brain damage observed, should be considered when animal model-based data are compared to human pathology. PMID:17971868

  8. Amelioration of myocardial ischemic reperfusion injury with Calendula officinalis.

    PubMed

    Ray, Diptarka; Mukherjee, Subhendu; Falchi, Mario; Bertelli, Aldo; Das, Dipak K

    2010-12-01

    Calendula officinalis of family Asteraceae, also known as marigold, has been widely used from time immemorial in Indian and Arabic cultures as an anti-inflammatory agent to treat minor skin wound and infections, burns, bee stings, sunburn and cancer. At a relatively high dose, calendula can lower blood pressure and cholesterol. Since inflammatory responses are behind many cardiac diseases, we sought to evaluate if calendula could be cardioprotective against ischemic heart disease Two groups of hearts were used: the treated rat hearts were perfused with calendula solution at 50 mM in KHB buffer (in mM: sodium chloride 118, potassium chloride 4.7, calcium chloride 1.7, sodium bicarbonate 25, potassium biphosphate 0.36, magnesium sulfate 1.2, and glucose 10) for 15 min prior to subjecting the heart to ischemia, while the control group was perfused with the buffer only. Calendula achieved cardioprotection by stimulating left ventricular developed pressure and aortic flow as well as by reducing myocardial infarct size and cardiomyocyte apoptosis. Cardioprotection appears to be achieved by changing ischemia reperfusion-mediated death signal into a survival signal by modulating antioxidant and anti-inflammatory pathways as evidenced by the activation of Akt and Bcl2 and depression of TNFα. The results further strengthen the concept of using natural products in degeneration diseases like ischemic heart disease.

  9. Perfusion Bioreactor Module

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R.

    1990-01-01

    Perfusion bioreactor module, self-contained, closed-loop cell-culture system that operates in microgravity or on Earth. Equipment supports growth or long-term maintenance of cultures of human or other fragile cells for experiments in basic cell biology or process technology. Designed to support proliferation (initially at exponential rates of growth) of cells in complex growth medium and to maintain confluent cells in defined medium under conditions optimized to permit or encourage selected functions of cells, including secretion of products of cells into medium.

  10. [Evaluation of a new technique of extracorporeal perfusion of the swine liver on a swine-primate model].

    PubMed

    Beaufigeau, M; Wolf, P; Azimzadeh, A; Godfrin, Y; Beller, J P; Boudjema, K; Jaeck, D; Kieny, R; Cinqualbre, J

    1996-01-01

    With the increasing success of liver transplantation there is an urgent need for developing an artificial liver support system to be used in patients with liver failure. An extracorporeal porcine liver perfusion machine was successfully tested in animals with experimental liver failure. Livers were flushed, removed from 35 kg pigs and placed in a heated sterile cassette. The portal vein and the hepatic artery of the graft were connected to the arterial system of the animals. The perfusion pressure of the hepatic artery was regulated via a pressure-flow computerized feed-back device. The venous flow was reinfused from the hepatic veins of the graft to the jugular vein of the animals. The experimental work consisted in two steps: 1. evaluation of clinical and biological consequences of liver perfusion in healthy animals (Group A = pigs, n = 3; group B = primates, n = 3); 2. evaluation of the efficiency of the liver perfusion in animals with ischemic liver failure (Groupe D = pigs, n = 6). The control group (Group C = pigs, n = 7) consisted of pigs with ischemic liver failure without hepatic support. No major clinical or biological adverse effects are reported in groups A and B excepted a thrombocytmia and a marked increase in serum transaminases levels in group B. Liver function as assessed by the bile flow was good in both groups. Comatose pigs with ischemic hepatic failure (group D) recovered a subnormal neurological status in five out of six cases. Serum ammoniemia level were significantly decreased (from 1076 +/- 163 to 255 +/- 32 umol/l). A decrease in serum bilirubine levels and an improvement in the coagulation profile were observed in the perfused animals. Pigs and primates tolerated the perfusion procedure well and beneficial effects were observed in perfused pigs with experimental liver failure.

  11. Myocardial contrast echocardiography to assess perfusion in a mouse model of ischemia/reperfusion injury

    NASA Astrophysics Data System (ADS)

    Hossack, John A.; Li, Yinbo; Christensen, Jonathan P.; Yang, Zequan; French, Brent A.

    2004-04-01

    Noninvasive approaches for measuring anatomical and physiological changes resulting from myocardial ischemia / reperfusion injury in the mouse heart have significant value since the mouse provides a practical, low-cost model for modeling human heart disease. In this work, perfusion was assessed before, during and after an induced closed- chest, coronary ischemic event. Ultrasound contrast agent, similar to MP1950, in a saline suspension, was injected via cannulated carotid artery as a bolus and imaged using a Siemens Sequoia 512 scanner and a 15L8 intraoperative transducer operating in second harmonic imaging mode. Image sequences were transferred from the scanner to a PC for analysis. Regions of interest were defined in septal and anterior segments of the myocardium. During the ischemic event, when perfusion was diminished in the anterior segment, mean video intensity in the affected segment was reduced by one half. Furthermore, following reperfusion, hyperemia (enhanced blood flow) was observed in the anterior segment. Specifically, the mean video intensity in the affected segment was increased by approximately 50% over the original baseline level prior to ischemia. Following the approach of Kaul et al., [1], gamma variate curves were fitted to the time varying level of mean video intensity. This foundation suggests the possibility of quantifying myocardial blood flow in ischemic regions of a mouse heart using automated analysis of contrast image data sets. An improved approach to perfusion assessment using the destruction-reperfusion approach [2] is also presented.

  12. Intravascular Perfusion of Carbon Black Ink Allows Reliable Visualization of Cerebral Vessels

    PubMed Central

    Hasan, Mohammad R.; Herz, Josephine; Hermann, Dirk M.; Doeppner, Thorsten R.

    2013-01-01

    The anatomical structure of cerebral vessels is a key determinant for brain hemodynamics as well as the severity of injury following ischemic insults. The cerebral vasculature dynamically responds to various pathophysiological states and it exhibits considerable differences between strains and under conditions of genetic manipulations. Essentially, a reliable technique for intracranial vessel staining is essential in order to study the pathogenesis of ischemic stroke. Until recently, a set of different techniques has been employed to visualize the cerebral vasculature including injection of low viscosity resin, araldite F, gelatin mixed with various dyes1 (i.e. carmine red, India ink) or latex with2 or without3 carbon black. Perfusion of white latex compound through the ascending aorta has been first reported by Coyle and Jokelainen3. Maeda et al.2 have modified the protocol by adding carbon black ink to the latex compound for improved contrast visualization of the vessels after saline perfusion of the brain. However, inefficient perfusion and inadequate filling of the vessels are frequently experienced due to high viscosity of the latex compound4. Therefore, we have described a simple and cost-effective technique using a mixture of two commercially available carbon black inks (CB1 and CB2) to visualize the cerebral vasculature in a reproducible manner5. We have shown that perfusion with CB1+CB2 in mice results in staining of significantly smaller cerebral vessels at a higher density in comparison to latex perfusion5. Here, we describe our protocol to identify the anastomotic points between the anterior (ACA) and middle cerebral arteries (MCA) to study vessel variations in mice with different genetic backgrounds. Finally, we demonstrate the feasibility of our technique in a transient focal cerebral ischemia model in mice by combining CB1+CB2-mediated vessel staining with TTC staining in various degrees of ischemic injuries. PMID:23328838

  13. Effect of zinc supplements in the attenuated cardioprotective effect of ischemic preconditioning in hyperlipidemic rat heart.

    PubMed

    Kansal, Sunil Kumar; Jyoti, Uma; Sharma, Samridhi; Kaura, Arun; Deshmukh, Rahul; Goyal, Sandeep

    2015-06-01

    Hyperlipidemia is regarded as independent risk factor in the development of ischemic heart disease, and it can increase the myocardial susceptibility to ischemia-/reperfusion (I/R)-induced injury. Hyperlipidemia attenuates the cardioprotective response of ischemic preconditioning (IPC). The present study investigated the effect of zinc supplements in the attenuated cardioprotective effect of ischemic preconditioning in hyperlipidemic rat hearts. Hyperlipidemia was induced in rat by feeding high-fat diet (HFD) for 6 weeks then the serum lipid profile was observed. In experiment, the isolated Langendorff rat heart preparation was subjected to 4 cycles of ischemic preconditioning (IPC), then 30 min of ischemia followed by 120 min of reperfusion. Myocardial infarct size was elaborated morphologically by triphenyltetrazolium chloride (TTC) staining and biochemically by lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) release from coronary effluent and left ventricular collagen content. However, the effect of zinc supplement, i.e., zinc pyrithione (10 μM) perfused during reperfusion for 120 min, significantly abrogated the attenuated cardioprotective effect of ischemic preconditioning in hyperlipidemic rat heart whereas administration of chelator of this zinc ionophore, i.e., N,N,N',N'-tetrakis(2-pyridylmethyl)ethylene diamine (TPEN; 10 μM), perfused during reperfusion 2 min before the perfusion of zinc pyrithione abrogated the cardioprotective effect of zinc supplement during experiment in hyperlipidemic rat heart. Thus, the administration of zinc supplements limits the infarct size, LDH, and CK-MB and enhanced the collagen level which suggests that the attenuated cardioprotective effect of IPC in hyperlipidemic rat is due to zinc loss during reperfusion caused by ischemia/reperfusion. PMID:25743572

  14. Lung Ventilation/Perfusion Scan

    MedlinePlus

    ... from the NHLBI on Twitter. What Is a Lung Ventilation/Perfusion Scan? A lung ventilation/perfusion scan, or VQ scan, is a ... that measures air and blood flow in your lungs. A VQ scan most often is used to ...

  15. Ex-vivo lung perfusion.

    PubMed

    Van Raemdonck, Dirk; Neyrinck, Arne; Cypel, Marcelo; Keshavjee, Shaf

    2015-06-01

    This review outlines the new and promising technique of ex vivo lung perfusion and its clinical potential to increase the number of transplantable lungs and to improve the early and late outcome after transplantation. The rationale, the experimental background, the technique and protocols, and available devices for ex vivo lung perfusion are discussed. The current clinical experience worldwide and ongoing clinical trials are reviewed.

  16. Initial Radionuclide Inventories

    SciTech Connect

    Miller, H

    2005-07-12

    The purpose of this analysis is to provide an initial radionuclide inventory (in grams per waste package) and associated uncertainty distributions for use in the Total System Performance Assessment for the License Application (TSPA-LA) in support of the license application for the repository at Yucca Mountain, Nevada. This document is intended for use in postclosure analysis only. Bounding waste stream information and data were collected that capture probable limits. For commercially generated waste, this analysis considers alternative waste stream projections to bound the characteristics of wastes likely to be encountered using arrival scenarios that potentially impact the commercial spent nuclear fuel (CSNF) waste stream. For TSPA-LA, this radionuclide inventory analysis considers U.S. Department of Energy (DOE) high-level radioactive waste (DHLW) glass and two types of spent nuclear fuel (SNF): CSNF and DOE-owned (DSNF). These wastes are placed in two groups of waste packages: the CSNF waste package and the codisposal waste package (CDSP), which are designated to contain DHLW glass and DSNF, or DHLW glass only. The radionuclide inventory for naval SNF is provided separately in the classified ''Naval Nuclear Propulsion Program Technical Support Document'' for the License Application. As noted previously, the radionuclide inventory data presented here is intended only for TSPA-LA postclosure calculations. It is not applicable to preclosure safety calculations. Safe storage, transportation, and ultimate disposal of these wastes require safety analyses to support the design and licensing of repository equipment and facilities. These analyses will require radionuclide inventories to represent the radioactive source term that must be accommodated during handling, storage and disposition of these wastes. This analysis uses the best available information to identify the radionuclide inventory that is expected at the last year of last emplacement, currently identified as

  17. Initial Radionuclide Inventories

    SciTech Connect

    H. Miller

    2004-09-19

    The purpose of this analysis is to provide an initial radionuclide inventory (in grams per waste package) and associated uncertainty distributions for use in the Total System Performance Assessment for the License Application (TSPA-LA) in support of the license application for the repository at Yucca Mountain, Nevada. This document is intended for use in postclosure analysis only. Bounding waste stream information and data were collected that capture probable limits. For commercially generated waste, this analysis considers alternative waste stream projections to bound the characteristics of wastes likely to be encountered using arrival scenarios that potentially impact the commercial spent nuclear fuel (CSNF) waste stream. For TSPA-LA, this radionuclide inventory analysis considers U.S. Department of Energy (DOE) high-level radioactive waste (DHLW) glass and two types of spent nuclear fuel (SNF): CSNF and DOE-owned (DSNF). These wastes are placed in two groups of waste packages: the CSNF waste package and the codisposal waste package (CDSP), which are designated to contain DHLW glass and DSNF, or DHLW glass only. The radionuclide inventory for naval SNF is provided separately in the classified ''Naval Nuclear Propulsion Program Technical Support Document'' for the License Application. As noted previously, the radionuclide inventory data presented here is intended only for TSPA-LA postclosure calculations. It is not applicable to preclosure safety calculations. Safe storage, transportation, and ultimate disposal of these wastes require safety analyses to support the design and licensing of repository equipment and facilities. These analyses will require radionuclide inventories to represent the radioactive source term that must be accommodated during handling, storage and disposition of these wastes. This analysis uses the best available information to identify the radionuclide inventory that is expected at the last year of last emplacement, currently identified as

  18. Radionuclide studies in impotence

    SciTech Connect

    Hilson, A.J.; Lewis, C.A. )

    1991-04-01

    Impotence may be of physiological origin with causes including vascular or neurological pathology. Alternatively, it may be of psychogenic origin. Clinicians can distinguish between psychological and organic impotence by observing nocturnal penile tumescence. Non-radionuclide investigations for organic impotence include penile plethysmography or pulse Doppler analysis for arterial supply, cavernosometry for venous drainage, and biothesiometry or evoked potentials for neurological pathology. Radionuclide studies are primarily based on the use of technetium 99m-pertechnetate, 99mTc-red blood cells, or xenon 133 to study the blood flow, with or without pharmacological intervention, commonly papaverine. 26 references.

  19. Imaging acute ischemic stroke.

    PubMed

    González, R Gilberto; Schwamm, Lee H

    2016-01-01

    Acute ischemic stroke is common and often treatable, but treatment requires reliable information on the state of the brain that may be provided by modern neuroimaging. Critical information includes: the presence of hemorrhage; the site of arterial occlusion; the size of the early infarct "core"; and the size of underperfused, potentially threatened brain parenchyma, commonly referred to as the "penumbra." In this chapter we review the major determinants of outcomes in ischemic stroke patients, and the clinical value of various advanced computed tomography and magnetic resonance imaging methods that may provide key physiologic information in these patients. The focus is on major strokes due to occlusions of large arteries of the anterior circulation, the most common cause of a severe stroke syndrome. The current evidence-based approach to imaging the acute stroke patient at the Massachusetts General Hospital is presented, which is applicable for all stroke types. We conclude with new information on time and stroke evolution that imaging has revealed, and how it may open the possibilities of treating many more patients. PMID:27432672

  20. PERFUSION FOR MYOCARDIAL REVASCULARIZATION WITHOUT AN ARTIFICIAL OXYGENATOR (New Method to Reduce Surgical Morbidity)

    PubMed Central

    De Moraes, Domingos Junqueira; Abilio, Fued Michel; Cunha, Marcos; Feitosa, Lionicio A.; Aragão, Esmeraldino; Cysne, Eumenes; Vieira, Roberto; Glavam, Haroldo C. C.; Zaniolo, Waldomiro; Netto, Mario Salles; Villela, Ronaldo De A.; Labrunie, Pierre

    1979-01-01

    Thirteen patients were submitted to direct myocardial revascularization (saphenous vein graft) without the use of an artificial oxygenator. The perfusion was done by a left ventricle-to-aorta bypass and autogenous oxygenation. Most patients had three grafts implanted plus endarterectomy of the distal right coronary artery. There was one hospital death that was apparently not related to the method used. Perfusion time ranged from 45 minutes to 4 hours. Body temperature during perfusion was kept between 25 and 30° C. Perfusion flow was maintained between 25 to 50 ml per kg of body weight per minute. Ischemic, hypothermic cardiac arrest was employed. We demonstrated for the first time that perfusion for this kind of heart surgery could be done with no artificial oxygenators and, apparently, is safer for the patients. There were no bleeding problems even in perfusions as long as 4 hours. There was no respiratory dysfunction, and artificial respiration was used for only 6 to 12 hours. The patients awoke at the end of surgery with no signs or symptoms of central nervous system damage, and vasopressor drugs were rarely used after surgery. Although the experience is very small, it suggests that many postoperative problems, especially those related to bleeding and respiratory dysfunction may be reduced or eliminated by this new method. PMID:15216319

  1. Cerebral perfusion imaging with bolus harmonic imaging (Honorable Mention Poster Award)

    NASA Astrophysics Data System (ADS)

    Kier, Christian; Toth, Daniel; Meyer-Wiethe, Karsten; Schindler, Angela; Cangur, Hakan; Seidel, Gunter; Aach, Til

    2005-04-01

    Fast visualisation of cerebral microcirculation supports diagnosis of acute stroke. However, the commonly used CT/MRI-based methods are time consuming, costly and not applicable to every patient. The bolus perfusion harmonic imaging (BHI) method is an ultrasound imaging technique which makes use of the fact, that ultrasound contrast agents unlike biological tissues resonate at harmonic frequencies. Exploiting this effect, the contrast between perfused and non-perfused areas can be improved. Thus, BHI overcomes the low signal-to-noise ratio of transcranial ultrasound and the high impedance of the skull. By analysing image sequences, visualising the qualitative characteristics of an US contrast agent bolus injection becomes possible. The analysis consists of calculating four perfusion-related parameters, Local Peak Intensity, Time To Peak, Area Under Curve, and Average Rising, from the time/intensity curve and providing them as colour-coded images. For calculating these parameters the fundamental assumption is that image intensity corresponds to contrast agent concentration which in turn shows the perfusion of the corresponding brain region. In a clinical study on patients suffering from acute ischemic stroke it is shown that some of the parameters correlate significantly to the infarction area. Thus, BHI becomes a less time-consuming and inexpensive bedside method for diagnosis of cerebral perfusion deficits.

  2. Magnetic Resonance Imaging in Acute Ischemic Stroke Treatment

    PubMed Central

    Kim, Bum Joon; Kang, Hyun Goo; Kim, Hye-Jin; Ahn, Sung-Ho; Kim, Na Young; Warach, Steven

    2014-01-01

    Although intravenous administration of tissue plasminogen activator is the only proven treatment after acute ischemic stroke, there is always a concern of hemorrhagic risk after thrombolysis. Therefore, selection of patients with potential benefits in overcoming potential harms of thrombolysis is of great importance. Despite the practical issues in using magnetic resonance imaging (MRI) for acute stroke treatment, multimodal MRI can provide useful information for accurate diagnosis of stroke, evaluation of the risks and benefits of thrombolysis, and prediction of outcomes. For example, the high sensitivity and specificity of diffusion-weighted image (DWI) can help distinguish acute ischemic stroke from stroke-mimics. Additionally, the lesion mismatch between perfusion-weighted image (PWI) and DWI is thought to represent potential salvageable tissue by reperfusion therapy. However, the optimal threshold to discriminate between benign oligemic areas and the penumbra is still debatable. Signal changes of fluid-attenuated inversion recovery image within DWI lesions may be a surrogate marker for ischemic lesion age and might indicate risks of hemorrhage after thrombolysis. Clot sign on gradient echo image may reflect the nature of clot, and their location, length and morphology may provide predictive information on recanalization by reperfusion therapy. However, previous clinical trials which solely or mainly relied on perfusion-diffusion mismatch for patient selection, failed to show benefits of MRI-based thrombolysis. Therefore, understanding the clinical implication of various useful MRI findings and comprehensively incorporating those variables into therapeutic decision-making may be a more reasonable approach for expanding the indication of acute stroke thrombolysis. PMID:25328872

  3. New objective criterion for determining, noninvasively, the healing potential of an ischemic ulcer

    SciTech Connect

    Siegel, M.E.; Stewart, C.A.; Wagner, W.; Sakimura, I.

    1981-02-01

    Peripheral vascular perfusion studies using intravenously administered thallium-201 were performed on 13 patients suffering from ischemic ulcer of the lower extermities. Scintillation camera views and point counting over the lesion and adjacent region were utilized to define qualitatively and quantitatively the relative hyperemia of the lesion. The preliminary findings demonstrate that when the relative hyperemia was equal to or greater than 1.5, 100% (seven of seven) went on to heal their ulcer with conservative management. Of those without this degree of hyperemia, 83% (five of six) will require amputation. Based on this limited series, noninvasive assessment of the relative hyperemia of an ischemic ulcer using thallium-201 is a new, useful, and objective indicator of the healing potential of a so-called ischemic ulcer.

  4. Myogenic tone as a therapeutic target for ischemic stroke.

    PubMed

    Palomares, Sara M; Cipolla, Marilyn J

    2014-01-01

    Ischemic stroke causes vascular paralysis and impaired autoregulation in the brain, the degree of which is dependent on the depth and duration of ischemia and reperfusion (I/R). Ischemic stroke also impairs the myogenic response of middle cerebral arteries (MCA) that may be an underlying mechanism by which autoregulation is impaired. Myogenic responses are affected by I/R through several mechanisms, including production of peroxynitrite, depolymerization of F-actin in vascular smooth muscle, and circulating vasoactive factors. The vascular endothelium is also significantly affected during focal ischemia that has a particularly large influence on vascular tone in the cerebral circulation. Endothelial nitric oxide (NO) and endothelin-1 (ET-1) are important endothelium-dependent vasoactive substances that can influence the level of myogenic tone in cerebral arteries and arterioles that are significantly affected during ischemic stroke. Unlike MCA, brain penetrating arterioles have considerable myogenic tone that appears less affected by focal ischemia. The persistent tone of brain parenchymal arterioles during focal ischemia could contribute to perfusion deficit and infarct expansion. These arterioles within the cerebral cortex are also unique from MCA in that they constrict to small- and intermediate- conductance calcium-activated potassium channel (SKCa and IKCa, respectively) inhibition, suggesting basal endothelium-derived hyperpolarizing factor (EDHF) is preserved during focal ischemia. This review will highlight our current understanding of the effects of I/R on myogenic response in both MCA and parenchymal arterioles and discuss underlying mechanisms by which focal ischemia affects myogenic tone in these different vascular segments.

  5. Drag-Reducing Polymer Enhances Microvascular Perfusion in the Traumatized Brain with Intracranial Hypertension.

    PubMed

    Bragin, Denis E; Thomson, Susan; Bragina, Olga; Statom, Gloria; Kameneva, Marina V; Nemoto, Edwin M

    2016-01-01

    Current treatments for traumatic brain injury (TBI) have not focused on improving microvascular perfusion. Drag-reducing polymers (DRP), linear, long-chain, blood-soluble, nontoxic macromolecules, may offer a new approach to improving cerebral perfusion by primary alteration of the fluid dynamic properties of blood. Nanomolar concentrations of DRP have been shown to improve hemodynamics in animal models of ischemic myocardium and ischemic limb, but have not yet been studied in the brain. We recently demonstrated that DRP improved microvascular perfusion and tissue oxygenation in a normal rat brain. We hypothesized that DRP could restore microvascular perfusion in hypertensive brain after TBI. Using in vivo two-photon laser scanning microscopy we examined the effect of DRP on microvascular blood flow and tissue oxygenation in hypertensive rat brains with and without TBI. DRP enhanced and restored capillary flow, decreased microvascular shunt flow, and, as a result, reduced tissue hypoxia in both nontraumatized and traumatized rat brains at high intracranial pressure. Our study suggests that DRP could constitute an effective treatment for improving microvascular flow in brain ischemia caused by high intracranial pressure after TBI. PMID:27165871

  6. Drag-Reducing Polymer Enhances Microvascular Perfusion in the Traumatized Brain with Intracranial Hypertension.

    PubMed

    Bragin, Denis E; Thomson, Susan; Bragina, Olga; Statom, Gloria; Kameneva, Marina V; Nemoto, Edwin M

    2016-01-01

    Current treatments for traumatic brain injury (TBI) have not focused on improving microvascular perfusion. Drag-reducing polymers (DRP), linear, long-chain, blood-soluble, nontoxic macromolecules, may offer a new approach to improving cerebral perfusion by primary alteration of the fluid dynamic properties of blood. Nanomolar concentrations of DRP have been shown to improve hemodynamics in animal models of ischemic myocardium and ischemic limb, but have not yet been studied in the brain. We recently demonstrated that DRP improved microvascular perfusion and tissue oxygenation in a normal rat brain. We hypothesized that DRP could restore microvascular perfusion in hypertensive brain after TBI. Using in vivo two-photon laser scanning microscopy we examined the effect of DRP on microvascular blood flow and tissue oxygenation in hypertensive rat brains with and without TBI. DRP enhanced and restored capillary flow, decreased microvascular shunt flow, and, as a result, reduced tissue hypoxia in both nontraumatized and traumatized rat brains at high intracranial pressure. Our study suggests that DRP could constitute an effective treatment for improving microvascular flow in brain ischemia caused by high intracranial pressure after TBI.

  7. [Examination of Visual Effect in Low-dose Cerebral CT Perfusion Phantom Image Using Iterative Reconstruction].

    PubMed

    Ohmura, Tomomi; Lee, Yongbum; Takahashi, Noriyuki; Sato, Yuichiro; Ishida, Takato; Toyoshima, Hideto

    2015-11-01

    CT perfusion (CTP) is obtained cerebrovascular circulation image for assessment of stroke patients; however, at the expense of increased radiation dose by dynamic scan. Iterative reconstruction (IR) method is possible to decrease image noise, it has the potential to reduce radiation dose. The purpose of this study is to assess the visual effect of IR method by using a digital perfusion phantom. The digital perfusion phantom was created by reconstructed filtered back projection (FBP) method and IR method CT images that had five exposure doses. Various exposure dose cerebral blood flow (CBF) images were derived from deconvolution algorithm. Contrast-to-noise ratio (CNR) and visual assessment were compared among the various exposure dose and each reconstructions. Result of low exposure dose with IR method showed, compared with FBP method, high CNR in severe ischemic area, and visual assessment was significantly improvement. IR method is useful for improving image quality of low-dose CTP. PMID:26596197

  8. Myocardial perfusion assessment with contrast echocardiography

    NASA Astrophysics Data System (ADS)

    Desco, Manuel; Ledesma-Carbayo, Maria J.; Santos, Andres; Garcia-Fernandez, Miguel A.; Marcos-Alberca, Pedro; Malpica, Norberto; Antoranz, Jose C.; Garcia-Barreno, Pedro

    2001-05-01

    Assessment of intramyocardial perfusion by contrast echocardiography is a promising new technique that allows to obtain quantitative parameters for the assessment of ischemic disease. In this work, a new methodology and a software prototype developed for this task are presented. It has been validated with Coherent Contrast Imaging (CCI) images acquired with an Acuson Sequoia scanner. Contrast (Optison microbubbles) is injected continuously during the scan. 150 images are acquired using low mechanical index U/S pulses. A burst of high mechanical index pulses is used to destroy bubbles, thus allowing to detect the contrast wash-in. The stud is performed in two conditions: rest and pharmacologically induced stress. The software developed allows to visualized the study (cine) and to select several ROIs within the heart wall. The position of these ROIs along the cardiac cycle is automatically corrected on the basis of the gradient field, and they can also be manually corrected in case the automatic procedure fails. Time curves are analyzed according to a parametric model that incorporates both contrast inflow rate and cyclic variations. Preliminary clinical results on 80 patients have allowed us to identify normal and pathological patterns and to establish the correlation of quantitative parameters with the real diagnosis.

  9. Ex vivo lung perfusion.

    PubMed

    Machuca, Tiago N; Cypel, Marcelo

    2014-08-01

    Lung transplantation (LTx) is an established treatment option for eligible patients with end-stage lung disease. Nevertheless, the imbalance between suitable donor lungs available and the increasing number of patients considered for LTx reflects in considerable waitlist mortality. Among potential alternatives to address this issue, ex vivo lung perfusion (EVLP) has emerged as a modern preservation technique that allows for more accurate lung assessment and also improvement of lung function. Its application in high-risk donor lungs has been successful and resulted in safe expansion of the donor pool. This article will: (I) review the technical details of EVLP; (II) the rationale behind the method; (III) report the worldwide clinical experience with the EVLP, including the Toronto technique and others; (IV) finally, discuss the growing literature on EVLP application for donation after cardiac death (DCD) lungs. PMID:25132972

  10. Ex vivo lung perfusion

    PubMed Central

    Machuca, Tiago N.

    2014-01-01

    Lung transplantation (LTx) is an established treatment option for eligible patients with end-stage lung disease. Nevertheless, the imbalance between suitable donor lungs available and the increasing number of patients considered for LTx reflects in considerable waitlist mortality. Among potential alternatives to address this issue, ex vivo lung perfusion (EVLP) has emerged as a modern preservation technique that allows for more accurate lung assessment and also improvement of lung function. Its application in high-risk donor lungs has been successful and resulted in safe expansion of the donor pool. This article will: (I) review the technical details of EVLP; (II) the rationale behind the method; (III) report the worldwide clinical experience with the EVLP, including the Toronto technique and others; (IV) finally, discuss the growing literature on EVLP application for donation after cardiac death (DCD) lungs. PMID:25132972

  11. [Cerebrolysin for acute ischemic stroke].

    PubMed

    iganshina, L E; Abakumova, T R

    2013-01-01

    The review discusses existing evidence of benefits and risks of cerebrolysin--a mixture of low-molecular-weight peptides and amino acids derived from pigs' brain tissue with proposed neuroprotective and neurotrophic properties, for acute ischemic stroke. The review presents results of systematic search and analysis of randomised clinical trials comparing cerebrolysin with placebo in patients with acute ischemic stroke. Only one trial was selected as meeting quality criteria. No difference in death and adverse events between cerebrolysin and placebo was established. The authors conclude about insufficiency of evidence to evaluate the effect of cerebrolysin on survival and dependency in people with acute ischemic stroke.

  12. Remote Ischemic Conditioning

    PubMed Central

    Heusch, Gerd; Bøtker, Hans Erik; Przyklenk, Karin; Redington, Andrew; Yellon, Derek

    2014-01-01

    In remote ischemic conditioning (RIC) brief, reversible episodes of ischemia with reperfusion in one vascular bed, tissue or organ confer a global protective phenotype and render remote tissues and organs resistant to ischemia/reperfusion injury. The peripheral stimulus can be chemical, mechanical or electrical and involves activation of peripheral sensory nerves. The signal transfer to the heart or other organs is through neuronal and humoral communications. Protection can be transferred, even across species, with plasma-derived dialysate and involves nitric oxide, stromal derived factor-1α, microRNA-144, but also other, not yet identified factors. Intracardiac signal transduction involves: adenosine, bradykinin, cytokines, and chemokines, which activate specific receptors; intracellular kinases; and mitochondrial function. RIC by repeated brief inflation/deflation of a blood pressure cuff protects against endothelial dysfunction and myocardial injury in percutaneous coronary interventions, coronary artery bypass grafting and reperfused acute myocardial infarction. RIC is safe and effective, noninvasive, easily feasible and inexpensive. PMID:25593060

  13. Ischemic bowel disease

    PubMed Central

    Castelli, M. F.; Qizilbash, A. H.; Salem, S.; Fyshe, T. G.

    1974-01-01

    The clinical, radiologic and pathologic features of 25 cases of ischemic bowel disease are presented. The majority of patients presented with the triad of abdominal pain, diarrhea and vomiting. In 13 patients the diarrhea was associated with the passage of bright red blood per rectum. There were 10 cases of infarction, 11 of enterocolitis and 4 had resulted in stricture formation. In five cases of enterocolitis the lesion was transient; symptoms improved with conservative medical management and the radiologic findings returned to normal. Barium enema examination yielded abnormal findings in the majority of the cases in which it was performed. Plain films of the abdomen, however, were not helpful. The actual mortality in this group of patients was 44%, 80% in those with infarction of the bowel and 20% in the other two groups. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5FIG. 6FIG. 7 PMID:4419659

  14. [Extracorporeal perfusion of the sheep rumen].

    PubMed

    Leng, L; Bajo, M; Várady, J; Szányiová, M

    1977-06-01

    We constructed a modified perfusion apparatus and elaborated a method of extracorporal perfusion of the rumen of sheep. As perfusates we used the bovine plasma diluted in a ratio of 1:1 of an isotonic sodium chloride (NaCl) solution and the whole autologous blood. Transaminases GOT and GPT, ammonia and pH were determined in the perfusate. The different perfusions were evaluated according to previously determined perfusion conditions and criteria. A subject for discussion is the question of suitability of the parameters under examination for judging the state of the perfused organ. The described method is suitable for the study of metabolical processes in the rumen wal.

  15. Distributed perfusion educational model: a shift in perfusion economic realities.

    PubMed

    Austin, Jon W; Evans, Edward L; Hoerr, Harry R

    2005-12-01

    In recent years, a steady decline in the number of perfusion education programs in the United States has been noted. At the same time, there has been a parallel decline in the number of students graduated from perfusion educational programs in the United States. Also, as noted by several authors, there has been an increase in demand for perfusion graduates. The decline in programs and graduates has also been noted in anesthesia and surgical residency programs. The shift is caused by a combination of economic and clinical factors. First, decreased reimbursement has led to reallocation of hospital resources. Second, the original enthusiasm for beating heart coronary artery bypass surgery was grossly overestimated and has led to further reallocation of hospital resources and denigration of cardiopulmonary bypass. This paper describes two models of perfusion education programs: serial perfusion education model (SPEM) and the distributed perfusion education model (DPEM). Arguments are presented that the SPEM has some serious limitations and challenges for long-term economic survival. The authors feel the DPEM along with dependence on tuition funding can survive the current clinical and economic conditions and allow the profession to adapt to changes in scope of practice. PMID:16524152

  16. EBS Radionuclide Transport Abstraction

    SciTech Connect

    J. Prouty

    2006-07-14

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment (TSPA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers advective transport and diffusive transport

  17. Preterm Hypoxic–Ischemic Encephalopathy

    PubMed Central

    Gopagondanahalli, Krishna Revanna; Li, Jingang; Fahey, Michael C.; Hunt, Rod W.; Jenkin, Graham; Miller, Suzanne L.; Malhotra, Atul

    2016-01-01

    Hypoxic–ischemic encephalopathy (HIE) is a recognizable and defined clinical syndrome in term infants that results from a severe or prolonged hypoxic–ischemic episode before or during birth. However, in the preterm infant, defining hypoxic–ischemic injury (HII), its clinical course, monitoring, and outcomes remains complex. Few studies examine preterm HIE, and these are heterogeneous, with variable inclusion criteria and outcomes reported. We examine the available evidence that implies that the incidence of hypoxic–ischemic insult in preterm infants is probably higher than recognized and follows a more complex clinical course, with higher rates of adverse neurological outcomes, compared to term infants. This review aims to elucidate the causes and consequences of preterm hypoxia–ischemia, the subsequent clinical encephalopathy syndrome, diagnostic tools, and outcomes. Finally, we suggest a uniform definition for preterm HIE that may help in identifying infants most at risk of adverse outcomes and amenable to neuroprotective therapies. PMID:27812521

  18. Simultaneous individually controlled upper and lower body perfusion for valve-sparing root and total aortic arch replacement: a case study.

    PubMed

    Fernandes, Philip; Mayer, Rick; Adams, Corey; Chu, Michael W A

    2011-12-01

    Optimal perfusion strategies for extensive aortic resection in patients with mega-aortic syndromes include: tailored myocardial preservation, antegrade cerebral perfusion, controlled hypothermia and selective organ perfusion. Typically, the aortic arch resection and elephant trunk procedure are performed under hypothermic circulatory arrest with myocardial and cerebral protection. However, mesenteric and systemic ischemia occur during circulatory arrest and commonly rely upon deep hypothermia alone for metabolic protection. We hypothesized that simultaneously controlled mesenteric and systemic perfusion can attenuate some of the metabolic debt accrued during circulatory arrest, which may help improve perioperative outcomes. The perfusion strategy consisted of delivering a 1 to 3 liter per minute flow at 25 degrees C to the head/upper body via right axillary graft and simultaneous perfusion to the lower body/ mesenteric organs of 1 to 3 liters per minute at 30 degrees C via a right femoral arterial graft. We describe our technique of simultaneous mesenteric, systemic, cerebral and myocardial perfusion, and protection utilized for a young male patient with Marfan's syndrome, while undergoing a valve sparing root replacement, total arch replacement and elephant trunk reconstruction. This perfusion technique allowed us to deliver differential flow rates and temperatures to the upper and lower body (cold head/warm lower body perfusion) to minimize ischemic debt and quickly reverse metabolic derangements. PMID:22416605

  19. Ex-vivo lung perfusion.

    PubMed

    Van Raemdonck, Dirk; Neyrinck, Arne; Cypel, Marcelo; Keshavjee, Shaf

    2015-06-01

    This review outlines the new and promising technique of ex vivo lung perfusion and its clinical potential to increase the number of transplantable lungs and to improve the early and late outcome after transplantation. The rationale, the experimental background, the technique and protocols, and available devices for ex vivo lung perfusion are discussed. The current clinical experience worldwide and ongoing clinical trials are reviewed. PMID:24629039

  20. Radionuclide bone imaging

    SciTech Connect

    Bassett, L.W.; Gold, R.H.; Webber, M.M.

    1981-12-01

    Radionuclide bone imaging of the skeleton, now well established as the most important diagnostic procedure in detecting bone metastases, is also a reliable method for the evaluation of the progression or regression of metastatic bone disease. The article concentrates on the technetium-99m agents and the value of these agents in the widespread application of low-dose radioisotope scanning in such bone diseases as metastasis, osteomyelitis, trauma, osteonecrosis, and other abnormal skeletal conditions.

  1. Radionuclide therapy beyond radioiodine.

    PubMed

    Gabriel, Michael

    2012-10-01

    For decades, Iodine-131 has been used for the treatment of patients with thyroid cancer. In recent years, increasingly, other radiopharmaceuticals are in clinical use in the treatment of various malignant diseases. Although in principle these therapies-as in all applications of radionuclides-special radiation protection measures are required, a separate nuclear medicine therapy department is not necessary in many cases due to the lower or lack of gamma radiation. In the following article, four different radionuclide therapies are more closely presented which are emerging in the last years. One of them is the "Peptide Receptor Radionuclide Therapy," the so-called PRRT in which radiolabeled somatostatin (SST)-receptor(R) ligands are used in patients with neuroendocrine tumors. On the basis of radiolabeled antibodies against CD20-positive cells, the so-called radioimmunotherapy is used in the treatment of certain forms of malignant lymphoma. In primary or secondary liver tumors, the (90)Y-labeled particles can be administered. Last but not the least, the palliative approach of bone-seeking radiopharmaceuticals is noted in patients with painful bone metastases.

  2. Hydrostatic determinants of cerebral perfusion

    SciTech Connect

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

    1986-05-01

    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.

  3. Metabolic profiling during ex vivo machine perfusion of the human liver

    PubMed Central

    Bruinsma, Bote G.; Sridharan, Gautham V.; Weeder, Pepijn D.; Avruch, James H.; Saeidi, Nima; Özer, Sinan; Geerts, Sharon; Porte, Robert J.; Heger, Michal; van Gulik, Thomas M.; Martins, Paulo N.; Markmann, James F.; Yeh, Heidi; Uygun, Korkut

    2016-01-01

    As donor organ shortages persist, functional machine perfusion is under investigation to improve preservation of the donor liver. The transplantation of donation after circulatory death (DCD) livers is limited by poor outcomes, but its application may be expanded by ex vivo repair and assessment of the organ before transplantation. Here we employed subnormothermic (21 °C) machine perfusion of discarded human livers combined with metabolomics to gain insight into metabolic recovery during machine perfusion. Improvements in energetic cofactors and redox shifts were observed, as well as reversal of ischemia-induced alterations in selected pathways, including lactate metabolism and increased TCA cycle intermediates. We next evaluated whether DCD livers with steatotic and severe ischemic injury could be discriminated from ‘transplantable’ DCD livers. Metabolomic profiling was able to cluster livers with similar metabolic patterns based on the degree of injury. Moreover, perfusion parameters combined with differences in metabolic factors suggest variable mechanisms that result in poor energy recovery in injured livers. We conclude that machine perfusion combined with metabolomics has significant potential as a clinical instrument for the assessment of preserved livers. PMID:26935866

  4. Catestatin improves post-ischemic left ventricular function and decreases ischemia/reperfusion injury in heart.

    PubMed

    Penna, Claudia; Alloatti, Giuseppe; Gallo, Maria Pia; Cerra, Maria Carmela; Levi, Renzo; Tullio, Francesca; Bassino, Eleonora; Dolgetta, Serena; Mahata, Sushil K; Tota, Bruno; Pagliaro, Pasquale

    2010-11-01

    The Chromogranin A (CgA)-derived anti-hypertensive peptide catestatin (CST) antagonizes catecholamine secretion, and is a negative myocardial inotrope acting via a nitric oxide-dependent mechanism. It is not known whether CST contributes to ischemia/reperfusion injury or is a component of a cardioprotective response to limit injury. Here, we tested whether CST by virtue of its negative inotropic activity improves post-ischemic cardiac function and cardiomyocyte survival. Three groups of isolated perfused hearts from adult Wistar rats underwent 30-min ischemia and 120-min reperfusion (I/R, Group 1), or were post-conditioned by brief ischemic episodes (PostC, 5-cycles of 10-s I/R at the beginning of 120-min reperfusion, Group 2), or with exogenous CST (75 nM for 20 min, CST-Post, Group-3) at the onset of reperfusion. Perfusion pressure and left ventricular pressure (LVP) were monitored. Infarct size was evaluated with nitroblue-tetrazolium staining. The CST (5 nM) effects were also tested in simulated ischemia/reperfusion experiments on cardiomyocytes isolated from young-adult rats, evaluating cell survival with propidium iodide labeling. Infarct size was 61 ± 6% of risk area in hearts subjected to I/R only. PostC reduced infarct size to 34 ± 5%. Infarct size in CST-Post was 36 ± 3% of risk area (P < 0.05 respect to I/R). CST-Post reduced post-ischemic rise of diastolic LVP, an index of contracture, and significantly improved post-ischemic recovery of developed LVP. In isolated cardiomyocytes, CST increased the cell viability rate by about 65% after simulated ischemia/reperfusion. These results suggest a novel cardioprotective role for CST, which appears mainly due to a direct reduction of post-ischemic myocardial damages and dysfunction, rather than to an involvement of adrenergic terminals and/or endothelium.

  5. Denervation in Femoral Artery-Ligated Hindlimbs Diminishes Ischemic Recovery Primarily via Impaired Arteriogenesis

    PubMed Central

    Qin, Yuansen; Liu, Ruiming; Wang, Huijin; Zhou, Yu; Wang, Shenming; Hu, Zuojun

    2016-01-01

    Aims Multiple factors regulate arteriogenesis. Peripheral nerves play a crucial role in vascular remodeling, but the function of peripheral nerves during arteriogenesis is obscure. Our study investigated the contribution of denervation to arteriogenesis during post-ischemic recovery from hindlimb femoral artery ligation. Methods and Results Sprague-Dawley rats were randomly allocated into four groups of normal control (NC), hindlimb ischemia (HI), hindlimb ischemia with denervation (HID) and hindlimb simple denervation (HD). Hindlimb ischemic recovery was assessed by clinical assessment and tibialis anterior muscle remodeling on day 28 post-surgery. Blood flow was determined by laser Doppler imaging on day 0, 3, 7, 14 and 28 post-surgery. Collateral number of hindlimb was observed by angiography and gracilis muscles were tested by immunostaining on day 7 and 28 post-surgery. Angiogenesis was accessed by counting CD31 positive capillaries in tibialis anterior muscles on day 28 post-surgery. Group HID showed impaired ischemic recovery compared with the other 3 groups and impaired blood flow recovery compared with group HI on day 28 post-surgery. The collateral number and capillary density of group HID were lower than group HI. The collateral diameter of both group HID and group HI significantly increased compared with group NC. However, the lumen diameter was much narrower and the vessel wall was much thicker in group HID than group HI. We also demonstrated that the thickened neointima of collaterals in group HID comprised of smooth muscle cells and endothelial cells. Conclusions Denervation of the ligated femoral artery in the hindlimb impairs ischemic recovery via impaired perfusion. The possible mechanisms of impaired perfusion are lower collateral number, lower capillary density and most likely narrower lumen, which damage ischemic recovery. This study illustrates the crucial role of peripheral nerves in arteriogenesis using a model combined ischemia with

  6. Twelve-Hour Hypothermic Machine Perfusion for Donor Heart Preservation Leads to Improved Ultrastructural Characteristics Compared to Conventional Cold Storage.

    PubMed

    Michel, Sebastian G; La Muraglia, Glenn M; Madariaga, Maria Lucia L; Titus, James S; Selig, Martin K; Farkash, Evan A; Allan, James S; Anderson, Lisa M; Madsen, Joren C

    2015-01-01

    BACKGROUND Hypothermic machine perfusion of donor hearts has the theoretical advantage of continuous aerobic metabolism and washes out toxic metabolic byproducts. Here, we studied the effect of hypothermic machine perfusion on cardiac myocyte integrity when hearts are preserved for longer ischemic times (12 hours). MATERIAL AND METHODS Pig hearts were harvested and stored in Celsior® solution for 12 hours using either conventional cold storage on ice (12 h CS, n=3) or pulsatile perfusion with the Paragonix Sherpa Perfusion™ Cardiac Transport System at different flow rates (12 h PP, n=3 or 12 h PP low flow, n=2). After cold preservation, hearts were reperfused using an LV isovolumic Langendorff system. Controls (n=3) were reperfused immediately after organ harvest. Biopsies were taken from the apex of the left ventricle before storage, after storage and after reperfusion to measure ATP and endothelin-1 content in the tissue. TUNEL staining for signs of apoptosis and electron microscopy of the donor hearts were performed. RESULTS 12 h PP hearts showed significantly more weight gain than 12 h CS and controls after preservation. Pulsatile perfused hearts showed less ATP depletion, lower endothelin-1 levels and less apoptosis after preservation compared to CS. Electron microscopy showed damaged muscle fibers, endothelial cell rupture, and injury of mitochondria in the 12 h CS group, while machine perfusion could preserve the cell structures. CONCLUSIONS Hypothermic machine perfusion of donor hearts can preserve the cell structures better than conventional cold storage in prolonged ischemic times. Hypothermic pulsatile perfusion may therefore enable longer preservation times of donor hearts. Whether this method is able to avoid primary graft failure after orthotopic heart transplantation remains to be evaluated in further studies.

  7. Prognostic accuracy of cerebral blood flow measurement by perfusion computed tomography, at the time of emergency room admission, in acute stroke patients.

    PubMed

    Wintermark, Max; Reichhart, Marc; Thiran, Jean-Philippe; Maeder, Philippe; Chalaron, Marc; Schnyder, Pierre; Bogousslavsky, Julien; Meuli, Reto

    2002-04-01

    The purpose of this study was to determine the prognostic accuracy of perfusion computed tomography (CT), performed at the time of emergency room admission, in acute stroke patients. Accuracy was determined by comparison of perfusion CT with delayed magnetic resonance (MR) and by monitoring the evolution of each patient's clinical condition. Twenty-two acute stroke patients underwent perfusion CT covering four contiguous 10mm slices on admission, as well as delayed MR, performed after a median interval of 3 days after emergency room admission. Eight were treated with thrombolytic agents. Infarct size on the admission perfusion CT was compared with that on the delayed diffusion-weighted (DWI)-MR, chosen as the gold standard. Delayed magnetic resonance angiography and perfusion-weighted MR were used to detect recanalization. A potential recuperation ratio, defined as PRR = penumbra size/(penumbra size + infarct size) on the admission perfusion CT, was compared with the evolution in each patient's clinical condition, defined by the National Institutes of Health Stroke Scale (NIHSS). In the 8 cases with arterial recanalization, the size of the cerebral infarct on the delayed DWI-MR was larger than or equal to that of the infarct on the admission perfusion CT, but smaller than or equal to that of the ischemic lesion on the admission perfusion CT; and the observed improvement in the NIHSS correlated with the PRR (correlation coefficient = 0.833). In the 14 cases with persistent arterial occlusion, infarct size on the delayed DWI-MR correlated with ischemic lesion size on the admission perfusion CT (r = 0.958). In all 22 patients, the admission NIHSS correlated with the size of the ischemic area on the admission perfusion CT (r = 0.627). Based on these findings, we conclude that perfusion CT allows the accurate prediction of the final infarct size and the evaluation of clinical prognosis for acute stroke patients at the time of emergency evaluation. It may also provide

  8. CAD system for automatic analysis of CT perfusion maps

    NASA Astrophysics Data System (ADS)

    Hachaj, T.; Ogiela, M. R.

    2011-03-01

    In this article, authors present novel algorithms developed for the computer-assisted diagnosis (CAD) system for analysis of dynamic brain perfusion, computer tomography (CT) maps, cerebral blood flow (CBF), and cerebral blood volume (CBV). Those methods perform both quantitative analysis [detection and measurement and description with brain anatomy atlas (AA) of potential asymmetries/lesions] and qualitative analysis (semantic interpretation of visualized symptoms). The semantic interpretation (decision about type of lesion: ischemic/hemorrhagic, is the brain tissue at risk of infraction or not) of visualized symptoms is done by, so-called, cognitive inference processes allowing for reasoning on character of pathological regions based on specialist image knowledge. The whole system is implemented in.NET platform (C# programming language) and can be used on any standard PC computer with.NET framework installed.

  9. EBS Radionuclide Transport Abstraction

    SciTech Connect

    J.D. Schreiber

    2005-08-25

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in ''Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration'' (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment for the license application (TSPA-LA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA-LA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers

  10. Ischemic Stroke after Heart Transplantation

    PubMed Central

    Acampa, Maurizio; Lazzerini, Pietro Enea; Guideri, Francesca; Tassi, Rossana; Martini, Giuseppe

    2016-01-01

    Cerebrovascular complications after orthotopic heart transplantation (OHT) are more common in comparison with neurological sequelae subsequent to routine cardiac surgery. Ischemic stroke and transient ischemic attack (TIA) are more common (with an incidence of up to 13%) than intracranial hemorrhage (2.5%). Clinically, ischemic stroke is manifested by the appearance of focal neurologic deficits, although sometimes a stroke may be silent or manifests itself by the appearance of encephalopathy, reflecting a diffuse brain disorder. Ischemic stroke subtypes distribution in perioperative and postoperative period after OHT is very different from classical distribution, with different pathogenic mechanisms. Infact, ischemic stroke may be caused by less common and unusual mechanisms, linked to surgical procedures and to postoperative inflammation, peculiar to this group of patients. However, many strokes (40%) occur without a well-defined etiology (cryptogenic strokes). A silent atrial fibrillation (AF) may play a role in pathogenesis of these strokes and P wave dispersion may represent a predictor of AF. In OHT patients, P wave dispersion correlates with homocysteine plasma levels and hyperhomocysteinemia could play a role in the pathogenesis of these strokes with multiple mechanisms increasing the risk of AF. In conclusion, stroke after heart transplantation represents a complication with considerable impact not only on mortality but also on subsequent poor functional outcome. PMID:26915504

  11. Radionuclide Sensors for Water Monitoring

    SciTech Connect

    Grate, Jay W.; Egorov, Oleg B.; DeVol, Timothy A.

    2005-09-01

    Radionuclide contamination in the soil and groundwater at U.S. Department of Energy (DOE) sites is a severe problem that requires monitoring and remediation. Radionuclide measurement techniques are needed to monitor surface waters, groundwater, and process waters. Typically, water samples are collected and transported to an analytical laboratory, where costly radiochemical analyses are performed. To date, there has been very little development of selective radionuclide sensors for alpha- and beta-emitting radionuclides such as 90Sr, 99Tc, and various actinides of interest.

  12. History of medical radionuclide production.

    PubMed

    Ice, R D

    1995-11-01

    Radionuclide production for medical use originally was incidental to isotope discoveries by physicists and chemists. Once the available radionuclides were identified they were evaluated for potential medical use. Hevesy first used 32P in 1935 to study phosphorous metabolism in rats. Since that time, the development of cyclotrons, linear accelerators, and nuclear reactors have produced hundreds of radionuclides for potential medical use. The history of medical radionuclide production represents an evolutionary, interdisciplinary development of applied nuclear technology. Today the technology is represented by a mature industry and provides medical benefits to millions of patients annually.

  13. Osteopetrosis: radiological & radionuclide imaging.

    PubMed

    Sit, Cherry; Agrawal, Kanhaiyalal; Fogelman, Ignac; Gnanasegaran, Gopinath

    2015-01-01

    Osteopetrosis is a rare inherited bone disease where bones harden and become abnormally dense. While the diagnosis is clinical, it also greatly relies on appearance of the skeleton radiographically. X-ray, radionuclide bone scintigraphy and magnetic resonance imaging have been reported to identify characteristics of osteopetrosis. We present an interesting case of a 59-year-old man with a history of bilateral hip fractures. He underwent (99m)Tc-methylene diphosphonate whole body scan supplemented with single-photon emission computed tomography/computed tomography of spine, which showed increased uptake in the humeri, tibiae and femora, which were in keeping with osteopetrosis.

  14. 3D imaging of myocardial perfusion and coronary tree morphology from a single rotational angiogram

    NASA Astrophysics Data System (ADS)

    Lauritsch, Günter; Rohkohl, Christopher; Hornegger, Joachim; Sinha, Anil-Martin; Brachmann, Johannes; Rieber, Johannes; Rittger, Harald

    2011-03-01

    Diagnosis and treatment of coronary heart disease are performed in the catheter laboratory using an angiographic X-ray C-arm system. The morphology of the coronary tree and potentially ischemic lesions are determined in 2D projection views. The hemodynamic impact of the lesion would be valuable information for treatment decision. Using other modalities for functional imaging is disrupting the clinical workflow since the patient has to be transferred from the catheter laboratory to another scanner, and back to the catheter laboratory for performing the treatment. In this work a novel technology is used for simultaneous 3D imaging of first pass perfusion and the morphology of the coronary tree from a single rotational angiogram. A selective, single shot of contrast agent of less than 20ml directly into the coronaries is sufficient for a proper contrast resolution. Due to the long acquisition time cardiac motion has to be considered. A novel reconstruction technique for estimation and compensation of cardiac motion from the acquired projection data is used. The overlay of the 3D structure of the coronary tree and the perfusion image shows the correlation of myocardial areas and the associated coronary sections supporting that region. In a case example scar lesions caused by a former myocardial infarct are investigated. A first pass perfusion defect is found which is validated by a late enhancement magnetic resonance image. No ischemic defects are found. The non vital regions are still supported by the coronary vasculature.

  15. Study of possible mechanism of protective effect of phosphocreatine on ischemic myocardium

    SciTech Connect

    Preobrazhenskii, A.N.; Dzhavadov, S.A.; Saks, V.A.

    1986-10-20

    The accumulation of (/sup 32/P)phosphocreatine by control and isolated perfused ischemic rat hearts was studied. It was found that at phosphocreatine concentrations of 0.5-10 mM in the perfusing solution the rate of phosphocreatine accumulation was twice as high in hearts subjected to ischemia for 35 min as in the control hearts and constituted 182 nmoles/min/g dry weight tissue at a phosphocreatine concentrations in the perfusate of 10 mM. 5'-Nucleotidase and phosphatase activities were found in the crude plasma membrane fraction from rat hearts. The pH-dependence of the activity of these enzymes was studied. The 5'-nucleotidase activity decreased 4- to 5-fold with a drop in the pH from 8.0 to 6.0. The phosphatase activity of the preparations increased 2-fold with a drop in the pH from 8.0 to 6.0. The 5'-nucleotidase activity was inhibited by 10 mM phosphocreatine in the presence of 5 mM Mg/sup 2 +/, and the degree of the inhibition depended on the pH. Maximum inhibition by phosphocreatine (58%) was observed at pH 6.0. The inhibition of phosphatase by phosphocreatine did not depend on the pH and reached 20% in the presence of 10 mM phosphocreatine. Some possible mechanisms of the protective effect of phosphocreatine on an ischemic myocardium are discussed.

  16. Direct effects of smoking on the heart: silent ischemic disturbances of coronary flow

    SciTech Connect

    Deanfield, J.E.; Shea, M.J.; Wilson, R.A.; Horlock, P.; de Landsheere, C.M.; Selwyn, A.P.

    1986-05-01

    Cigarette smoking is strongly associated with ischemic heart disease and acute coronary events. The effect of smoking a single cigarette on regional myocardial perfusion was studied in 13 chronic smokers with typical stable angina pectoris using positron emission tomography and rubidium-82 (/sup 82/Rb). Findings were compared with the effects of physical exercise. After exercise, 8 patients (61%) had angina, ST depression and abnormal regional myocardial perfusion. Uptake of /sup 82/Rb increased from 49 +/- 8 to 60 +/- 7 in remote myocardium, but decreased from 46 +/- 3 to 37 +/- 5 in an ischemic area. The remaining 5 patients (39%) had homogeneous increases in /sup 82/Rb uptake without angina or ST depression. After smoking, 6 of the 8 patients with positive exercise test responses had a decrease in /sup 82/Rb uptake, from 47 +/- 3 to 35 +/- 6 in the same segment of myocardium affected during exercise. However, in contrast to exercise, the events during smoking were largely silent. The absolute decreases in regional /sup 82/Rb uptake after smoking occurred at significantly lower levels of myocardial oxygen demand than after exercise. This suggests that an impairment of coronary blood supply is responsible. Thus, in smokers with coronary artery disease, each cigarette can cause profound silent disturbances of regional myocardial perfusion that are likely to occur frequently during daily life. Such repeated insults may represent an important mechanism linking smoking with coronary events.

  17. Targeted radionuclide therapy

    SciTech Connect

    Williams, Lawrence E.; DeNardo, Gerald L.; Meredith, Ruby F.

    2008-07-15

    Targeted radionuclide therapy (TRT) seeks molecular and functional targets within patient tumor sites. A number of agents have been constructed and labeled with beta, alpha, and Auger emitters. Radionuclide carriers spanning a broad range of sizes; e.g., antibodies, liposomes, and constructs such as nanoparticles have been used in these studies. Uptake, in percent-injected dose per gram of malignant tissue, is used to evaluate the specificity of the targeting vehicle. Lymphoma (B-cell) has been the primary clinical application. Extension to solid tumors will require raising the macroscopic absorbed dose by several-fold over values found in present technology. Methods that may effect such changes include multistep targeting, simultaneous chemotherapy, and external sequestration of the agent. Toxicity has primarily involved red marrow so that marrow replacement can also be used to enhance future TRT treatments. Correlation of toxicities and treatment efficiency has been limited by relatively poor absorbed dose estimates partly because of using standard (phantom) organ sizes. These associations will be improved in the future by obtaining patient-specific organ size and activity data with hybrid SPECT/CT and PET/CT scanners.

  18. Targeted radionuclide therapy

    PubMed Central

    Williams, Lawrence E.; DeNardo, Gerald L.; Meredith, Ruby F.

    2008-01-01

    Targeted radionuclide therapy (TRT) seeks molecular and functional targets within patient tumor sites. A number of agents have been constructed and labeled with beta, alpha, and Auger emitters. Radionuclide carriers spanning a broad range of sizes; e.g., antibodies, liposomes, and constructs such as nanoparticles have been used in these studies. Uptake, in percent-injected dose per gram of malignant tissue, is used to evaluate the specificity of the targeting vehicle. Lymphoma (B-cell) has been the primary clinical application. Extension to solid tumors will require raising the macroscopic absorbed dose by several-fold over values found in present technology. Methods that may effect such changes include multistep targeting, simultaneous chemotherapy, and external sequestration of the agent. Toxicity has primarily involved red marrow so that marrow replacement can also be used to enhance future TRT treatments. Correlation of toxicities and treatment efficiency has been limited by relatively poor absorbed dose estimates partly because of using standard (phantom) organ sizes. These associations will be improved in the future by obtaining patient-specific organ size and activity data with hybrid SPECT∕CT and PET∕CT scanners. PMID:18697529

  19. [Pregnancy and acute ischemic stroke].

    PubMed

    Bereczki, Dániel

    2016-05-15

    Pregnancy-related ischemic strokes play an important role in both maternal and fetal morbidity and mortality. Changes in hemostaseology and hemodynamics as well as risk factors related to or independent from pregnancy contribute to the increased stroke-risk during gestation and the puerperium. Potential teratogenic effects make diagnostics, acute therapy and prevention challenging. Because randomized, controlled trials are not available, a multicenter registry of patients with gestational stroke would be desirable. Until definite guidelines emerge, management of acute ischemic stroke during pregnancy remains individual, involving experts and weighing the risks and benefits.

  20. Ischemic hepatitis after percutaneous nephrolitotomy: A case report

    PubMed Central

    Temiz, Mustafa Zafer; Yuruk, Emrah; Teberik, Kutlu; Akbas, Burcu Kadriye; Piroglu, Mustafa Devrim; Oztorun, Hande Selvi; Kandirali, Engin

    2014-01-01

    INTRODUCTION Ischemic hepatitis (IH) is the necrosis of the centrilobular hepatocytes of liver and is secondary to liver hypoperfusion in most of the cases. The diagnosis is usually based on biochemical findings due to the absence of symptoms and signs. Although the disease course is often mild, and sometimes is even not diagnosed, the outcome is poor if the etiology of hypotension and liver anoxia is not promptly corrected. PRESENTATION OF CASE A 64-year-old patient who underwent percutaneous nephrolithotomy (PNL) for right renal pelvic stone developed acute IH at first postoperative day as a result of hemorrhage related severe hypotension. After restoring hemodynamic parameters, she completely recovered 2 weeks after the operation. DISCUSSION IH is a frequent cause of marked serum aminotransferase elevation and most commonly occurs as a result of arterial hypoxemia and insufficient hepatic perfusion. Although no specific treatment of IH exists, stabilizing the hemodynamic parameters of the patient resolves the problem in most of the cases. CONCLUSION This case is presented to demonstrate that ischemic hepatitis should be kept in mind if severe hemorrhage occurs during PNL. PMID:25437690

  1. Subnormothermic Perfusion in the Isolated Rat Liver Preserves the Antioxidant Glutathione and Enhances the Function of the Ubiquitin Proteasome System

    PubMed Central

    Alva, Norma; Sanchez-Nuño, Sergio; Dewey, Shannamar; Gomes, Aldrin V.

    2016-01-01

    The reduction of oxidative stress is suggested to be one of the main mechanisms to explain the benefits of subnormothermic perfusion against ischemic liver damage. In this study we investigated the early cellular mechanisms induced in isolated rat livers after 15 min perfusion at temperatures ranging from normothermia (37°C) to subnormothermia (26°C and 22°C). Subnormothermic perfusion was found to maintain hepatic viability. Perfusion at 22°C raised reduced glutathione levels and the activity of glutathione reductase; however, lipid and protein oxidation still occurred as determined by malondialdehyde, 4-hydroxynonenal-protein adducts, and advanced oxidation protein products. In livers perfused at 22°C the lysosomal and ubiquitin proteasome system (UPS) were both activated. The 26S chymotrypsin-like (β5) proteasome activity was significantly increased in the 26°C (46%) and 22°C (42%) groups. The increased proteasome activity may be due to increased Rpt6 Ser120 phosphorylation, which is known to enhance 26S proteasome activity. Together, our results indicate that the early events produced by subnormothermic perfusion in the liver can induce oxidative stress concomitantly with antioxidant glutathione preservation and enhanced function of the lysosomal and UPS systems. Thus, a brief hypothermia could trigger antioxidant mechanisms and may be functioning as a preconditioning stimulus. PMID:27800122

  2. Assessment of cardiac function using myocardial perfusion imaging technique on SPECT with 99mTc sestamibi

    NASA Astrophysics Data System (ADS)

    Gani, M. R. A.; Nazir, F.; Pawiro, S. A.; Soejoko, D. S.

    2016-03-01

    Suspicion on coronary heart disease can be confirmed by observing the function of left ventricle cardiac muscle with Myocardial Perfusion Imaging techniques. The function perfusion itself is indicated by the uptake of radiopharmaceutical tracer. The 31 patients were studied undergoing the MPI examination on Gatot Soebroto Hospital using 99mTc-sestamibi radiopharmaceutical with stress and rest conditions. Stress was stimulated by physical exercise or pharmacological agent. After two hours, the patient did rest condition on the same day. The difference of uptake percentage between stress and rest conditions will be used to determine the malfunction of perfusion due to ischemic or infarct. Degradation of cardiac function was determined based on the image-based assessment of five segments of left ventricle cardiac. As a result, 8 (25.8%) patients had normal myocardial perfusion and 11 (35.5%) patients suspected for having partial ischemia. Total ischemia occurred to 8 (25.8%) patients with reversible and irreversible ischemia and the remaining 4 (12.9%) patients for partial infarct with characteristic the percentage of perfusion ≤50%. It is concluded that MPI technique of image-based assessment on uptake percentage difference between stress and rest conditions can be employed to predict abnormal perfusion as complementary information to diagnose the cardiac function.

  3. Laser speckle contrast imaging identifies ischemic areas on gastric tube reconstructions following esophagectomy

    PubMed Central

    Milstein, Dan M.J.; Ince, Can; Gisbertz, Suzanne S.; Boateng, Kofi B.; Geerts, Bart F.; Hollmann, Markus W.; van Berge Henegouwen, Mark I.; Veelo, Denise P.

    2016-01-01

    Abstract Gastric tube reconstruction (GTR) is a high-risk surgical procedure with substantial perioperative morbidity. Compromised arterial blood supply and venous congestion are believed to be the main etiologic factors associated with early and late anastomotic complications. Identifying low blood perfusion areas may provide information on the risks of future anastomotic leakage and could be essential for improving surgical techniques. The aim of this study was to generate a method for gastric microvascular perfusion analysis using laser speckle contrast imaging (LSCI) and to test the hypothesis that LSCI is able to identify ischemic regions on GTRs. Patients requiring elective laparoscopy-assisted GTR participated in this single-center observational investigation. A method for intraoperative evaluation of blood perfusion and postoperative analysis was generated and validated for reproducibility. Laser speckle measurements were performed at 3 different time pointes, baseline (devascularized) stomach (T0), after GTR (T1), and GTR at 20° reverse Trendelenburg (T2). Blood perfusion analysis inter-rater reliability was high, with intraclass correlation coefficients for each time point approximating 1 (P < 0.0001). Baseline (T0) and GTR (T1) mean blood perfusion profiles were highest at the base of the stomach and then progressively declined towards significant ischemia at the most cranial point or anastomotic tip (P < 0.01). After GTR, a statistically significant improvement in mean blood perfusion was observed in the cranial gastric regions of interest (P < 0.05). A generalized significant decrease in mean blood perfusion was observed across all GTR regions of interest during 20° reverse Trendelenburg (P < 0.05). It was feasible to implement LSCI intraoperatively to produce blood perfusion assessments on intact and reconstructed whole stomachs. The analytical design presented in this study resulted in good reproducibility of gastric perfusion

  4. Noise characteristics of CT perfusion imaging: how does noise propagate from source images to final perfusion maps?

    NASA Astrophysics Data System (ADS)

    Li, Ke; Chen, Guang-Hong

    2016-03-01

    Cerebral CT perfusion (CTP) imaging is playing an important role in the diagnosis and treatment of acute ischemic strokes. Meanwhile, the reliability of CTP-based ischemic lesion detection has been challenged due to the noisy appearance and low signal-to-noise ratio of CTP maps. To reduce noise and improve image quality, a rigorous study on the noise transfer properties of CTP systems is highly desirable to provide the needed scientific guidance. This paper concerns how noise in the CTP source images propagates to the final CTP maps. Both theoretical deviations and subsequent validation experiments demonstrated that, the noise level of background frames plays a dominant role in the noise of the cerebral blood volume (CBV) maps. This is in direct contradiction with the general belief that noise of non-background image frames is of greater importance in CTP imaging. The study found that when radiation doses delivered to the background frames and to all non-background frames are equal, lowest noise variance is achieved in the final CBV maps. This novel equality condition provides a practical means to optimize radiation dose delivery in CTP data acquisition: radiation exposures should be modulated between background frames and non-background frames so that the above equality condition is satisïnAed. For several typical CTP acquisition protocols, numerical simulations and in vivo canine experiment demonstrated that noise of CBV can be effectively reduced using the proposed exposure modulation method.

  5. Reactor-Produced Medical Radionuclides

    SciTech Connect

    Mirzadeh, Saed; Mausner, Leonard; Garland, Marc A

    2011-01-01

    The therapeutic use of radionuclides in nuclear medicine, oncology and cardiology is the most rapidly growing use of medical radionuclides. Since most therapeutic radionuclides are neutron rich and decay by beta emission, they are reactor-produced. This chapter deals mainly with production approaches with neutrons. Neutron interactions with matter, neutron transmission and activation rates, and neutron spectra of nuclear reactors are discussed in some detail. Further, a short discussion of the neutron-energy dependence of cross sections, reaction rates in thermal reactors, cross section measurements and flux monitoring, and general equations governing the reactor production of radionuclides are presented. Finally, the chapter is concluded by providing a number of examples encompassing the various possible reaction routes for production of a number of medical radionuclides in a reactor.

  6. Genetic susceptibility to ischemic stroke

    PubMed Central

    Meschia, James F.; Worrall, Bradford B.; Rich, Stephen S.

    2014-01-01

    Clinicians who treat patients with stroke need to be aware of several single-gene disorders that have ischemic stroke as a major feature, including sickle cell disease, Fabry disease, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, and retinal vasculopathy with cerebral leukodystrophy. The reported genome-wide association studies of ischemic stroke and several related phenotypes (for example, ischemic white matter disease) have shown that no single common genetic variant imparts major risk. Larger studies with samples numbering in the thousands are ongoing to identify common variants with smaller effects on risk. Pharmacogenomic studies have uncovered genetic determinants of response to warfarin, statins and clopidogrel. Despite increasing knowledge of stroke genetics, incorporating this new knowledge into clinical practice remains a challenge. The goals of this article are to review common single-gene disorders relevant to ischemic stroke, summarize the status of candidate gene and genome-wide studies aimed at discovering genetic stroke risk factors, and to briefly discuss pharmacogenomics related to stroke treatment. PMID:21629240

  7. [Phenomenon of heart ischemic postconditioning].

    PubMed

    Maslov, L N; Mrochek, A G; Hanus, L; Pei, J -M; Zhang, Y; Wang, H; Naryzhnaia, N V

    2012-08-01

    Authors of review analyzed papers on problem of heart ischemic postconditioning. In the review, it was demonstrated that postconditioning decreased an infarct size, prevented cardiomyocytes apoptosis, improved cardiac contractility in reperfusion period, augmented cardiac tolerance to arrhythmogenic impact ofreperfusion, prevented neutrophil invasion into the reperfused heart, abolished reperfusion endothelial dysfunction and suppressed reperfusion oxidative stress in myocardium. PMID:23155619

  8. End-ischemic reconditioning of liver allografts: Controlling the rewarming.

    PubMed

    Hoyer, Dieter Paul; Paul, Andreas; Luer, Sebastian; Reis, Henning; Efferz, Patrik; Minor, Thomas

    2016-09-01

    Different nonhypothermic preservation modalities have shown beneficial effects in liver transplantation models. This study compares controlled oxygenated rewarming (COR) to normothermic machine perfusion (NMP) to resuscitate liver grafts following cold storage (CS). Porcine livers were preserved for 18 hours by CS. Before reperfusion, the grafts were put on a machine perfusion device (Liver Assist) for 3 hours and were randomly assigned to COR (n = 6) or NMP (n = 5) and compared to standard CS. COR was carried out with the new Custodiol-N solution, slowly increasing temperature from 8 °C to 20 °C during the first 90 minutes. NMP was carried out with diluted autologous blood at 37 °C for 3 hours. In both cases, the perfusate was oxygenated to partial pressure of oxygen > 500 mm Hg. Then liver viability was tested for 180 minutes during in vitro isolated sanguineous reperfusion. Activity of the mitochondrial caspase 9 was lower after COR. Measurement of tissue adenosine triphosphate and total adenine nucleotides at the end of the reconditioning period showed better energetic recovery after COR. COR also resulted in significantly lower enzyme leakage and higher bile production (P < 0.05) during reperfusion. This first comparison of COR and NMP as end-ischemic reconditioning modalities demonstrates superior results in terms of mitochondrial integrity resulting in better energetic recovery, less hepatocellular injury, and ultimately superior function in favor of COR. Liver Transplantation 22 1223-1230 2016 AASLD. PMID:27398813

  9. APT radionuclide production experiment

    SciTech Connect

    Ullmann, J.L.; Gavron, A.; King, J.D.

    1994-07-02

    Tritium ({sup 3}H, a heavy isotope of hydrogen) is produced by low energy neutron-induced reactions on various elements. One such reaction is n+{sup 3}He {yields}>{sup 3}H+{sup 1}H in which {sup 3}He is transmuted to tritium. Another reaction, which has been used in reactor production of tritium, is the n+{sup 6}Li {yields}> {sup 3}H+{sup 4}He reaction. Accelerator Production of Tritium relies on a high-energy proton beam to produce these neutrons using the spallation reaction, in which high-energy proton beam to produce these neutrons using the spallation reaction, in which high-energy protons reacting with a heavy nucleus produce a shower of low-energy neutrons and a lower-mass residual nucleus. It is important to quantify the residual radionuclides produced in the spallation target for two reasons. From an engineering point of view, one must understand short-lived isotopes that may contribute to decay heat. From a safety viewpoint, one must understand what nuclei and decay gammas are produced in order to design adequate shielding, to estimate ultimate waste disposal problems, and to predict possible effects due to accidental dispersion during operation. The authors have performed an experiment to measure the production of radioisotopes in stopping-length W and Pb targets irradiated by a 800 MeV proton beam, and are comparing the results to values obtained from calculations using LAHET and MCNP. The experiment was designed to pay particular attention to the short half-life radionuclides, which have not been previously measured. In the following, they present details of the experiment, explain how they analyzed the data and obtain the results, how they perform the calculations, and finally, how the experimental data agree with the calculations.

  10. Artificial tissues in perfusion culture.

    PubMed

    Sittinger, M; Schultz, O; Keyszer, G; Minuth, W W; Burmester, G R

    1997-01-01

    In the stagnant environment of traditional culture dishes it is difficult to generate long term experiments or artificial tissues from human cells. For this reason a perfusion culture system with a stable supply of nutrients was developed. Human chondrocytes were seeded three-dimensionally in resorbable polymer fleeces. The cell-polymer tissues were then mounted in newly developed containers (W.W. Minuth et al, Biotechniques, 1996) and continuously perfused by fresh medium for 40 days. Samples from the effluate were analyzed daily, and the pH of the medium and glucose concentration remained stable during this period. The lactid acid concentration increased from 0.17 mg/ml to 0.35 mg/ml, which was influenced by the degradation of the resorbable polymer fibers used as three dimensional support material for the cells. This perfusion system proved to be reliable especially in long term cultures. Any components in the culture medium of the cells could be monitored without disturbances as caused by manual medium replacement. These results suggest the described perfusion culture system to be a valuable and convenient tool for many applications in tissue engineering, especially in the generation of artificial connective tissue.

  11. Protein nitration impairs the myogenic tone of rat middle cerebral arteries in both ischemic and nonischemic hemispheres after ischemic stroke.

    PubMed

    Coucha, Maha; Li, Weiguo; Johnson, Maribeth H; Fagan, Susan C; Ergul, Adviye

    2013-12-01

    The myogenic response is crucial for maintaining vascular resistance to achieve constant perfusion during pressure fluctuations. Reduced cerebral blood flow has been reported in ischemic and nonischemic hemispheres after stroke. Ischemia-reperfusion injury and the resulting oxidative stress impair myogenic responses in the ischemic hemisphere. Yet, the mechanism by which ischemia-reperfusion affects the nonischemic side is still undetermined. The goal of the present study was to determine the effect of ischemia-reperfusion injury on the myogenic reactivity of cerebral vessels from both hemispheres and whether protein nitration due to excess peroxynitrite production is the underlying mechanism of loss of tone. Male Wistar rats were subjected to sham operation or 30-min middle cerebral artery occlusion/45-min reperfusion. Rats were administered saline, the peroxynitrite decomposition catalyst 5,10,15,20-tetrakis(4-sulfonatophenyl)prophyrinato iron (III), or the nitration inhibitor epicatechin at reperfusion. Middle cerebral arteries isolated from another set of control rats were exposed to ex vivo oxygen-glucose deprivation with and without glycoprotein 91 tat (NADPH oxidase inhibitor) or N(ω)-nitro-l-arginine methyl ester. Myogenic tone and nitrotyrosine levels were determined. Ischemia-reperfusion injury impaired the myogenic tone of vessels in both hemispheres compared with the sham group (P < 0.001). Vessels exposed to ex vivo oxygen-glucose deprivation experienced a similar loss of myogenic tone. Inhibition of peroxynitrite parent radicals significantly improved the myogenic tone. Peroxynitrite scavenging or inhibition of nitration improved the myogenic tone of vessels from ischemic (P < 0.001 and P < 0.05, respectively) and nonischemic (P < 0.01 and P < 0.05, respectively) hemispheres. Nitration was significantly increased in both hemispheres versus the sham group and was normalized with epicatechin treatment. In conclusion, ischemia-reperfusion injury impairs

  12. MicroRNAs in vascular tissue engineering and post-ischemic neovascularization☆

    PubMed Central

    Caputo, Massimo; Saif, Jaimy; Rajakaruna, Cha; Brooks, Marcus; Angelini, Gianni D.; Emanueli, Costanza

    2015-01-01

    Increasing numbers of paediatric patients with congenital heart defects are surviving to adulthood, albeit with continuing clinical needs. Hence, there is still scope for revolutionary new strategies to correct vascular anatomical defects. Adult patients are also surviving longer with the adverse consequences of ischemic vascular disease, especially after acute coronary syndromes brought on by plaque erosion and rupture. Vascular tissue engineering and therapeutic angiogenesis provide new hope for these patients. Both approaches have shown promise in laboratory studies, but have not yet been able to deliver clear evidence of clinical success. More research into biomaterials, molecular medicine and cell and molecular therapies is necessary. This review article focuses on the new opportunities offered by targeting microRNAs for the improved production and greater empowerment of vascular cells for use in vascular tissue engineering or for increasing blood perfusion of ischemic tissues by amplifying the resident microvascular network. PMID:25980937

  13. Usefulness of cardiac MRI in the prognosis and follow-up of ischemic heart disease.

    PubMed

    Hidalgo, A; Pons-Lladó, G

    2015-01-01

    Cardiac magnetic resonance imaging (MRI) is an important tool that makes it possible to evaluate patients with cardiovascular disease; in addition to infarction and alterations in myocardial perfusion, cardiac MRI is useful for evaluating other phenomena such as microvascular obstruction and ischemia. The main prognostic factors in cardiac MRI are ventricular dysfunction, necrosis in late enhancement sequences, and ischemia in stress sequences. In acute myocardial infarction, cardiac MRI can evaluate the peri-infarct zone and quantify the size of the infarct. Furthermore, cardiac MRI's ability to detect and evaluate microvascular obstruction makes it a fundamental tool for establishing the prognosis of ischemic heart disease. In patients with chronic ischemic heart disease, cardiac MRI can detect ischemia induced by pharmacological stress and can diagnose infarcts that can be missed on other techniques. PMID:25648795

  14. Usefulness of cardiac MRI in the prognosis and follow-up of ischemic heart disease.

    PubMed

    Hidalgo, A; Pons-Lladó, G

    2015-01-01

    Cardiac magnetic resonance imaging (MRI) is an important tool that makes it possible to evaluate patients with cardiovascular disease; in addition to infarction and alterations in myocardial perfusion, cardiac MRI is useful for evaluating other phenomena such as microvascular obstruction and ischemia. The main prognostic factors in cardiac MRI are ventricular dysfunction, necrosis in late enhancement sequences, and ischemia in stress sequences. In acute myocardial infarction, cardiac MRI can evaluate the peri-infarct zone and quantify the size of the infarct. Furthermore, cardiac MRI's ability to detect and evaluate microvascular obstruction makes it a fundamental tool for establishing the prognosis of ischemic heart disease. In patients with chronic ischemic heart disease, cardiac MRI can detect ischemia induced by pharmacological stress and can diagnose infarcts that can be missed on other techniques.

  15. Cardioprotection by remote ischemic preconditioning of the rat heart is mediated by extracellular vesicles.

    PubMed

    Giricz, Zoltán; Varga, Zoltán V; Baranyai, Tamás; Sipos, Péter; Pálóczi, Krisztina; Kittel, Ágnes; Buzás, Edit I; Ferdinandy, Péter

    2014-03-01

    Remote ischemic preconditioning (RIPC) of the heart is exerted by brief ischemic insults affected on a remote organ or a remote area of the heart before a sustained cardiac ischemia. To date, little is known about the inter-organ transfer mechanisms of cardioprotection by RIPC. Exosomes and microvesicles/microparticles are vesicles of 30-100 nm and 100-1000 nm in diameter, respectively (collectively termed extracellular vesicles [EVs]). Their content of proteins, mRNAs and microRNAs, renders EV ideal conveyors of inter-organ communication. However, whether EVs are involved in RIPC, is unknown. Therefore, here we investigated whether (1) IPC induces release of EVs from the heart, and (2) EVs are necessary for cardioprotection by RIPC. Hearts of male Wistar rats were isolated and perfused in Langendorff mode. A group of donor hearts was exposed to 3 × 5-5 min global ischemia and reperfusion (IPC) or 30 min aerobic perfusion, while coronary perfusates were collected. Coronary perfusates of these hearts were given to another set of recipient isolated hearts. A group of recipient hearts received IPC effluent depleted of EVs by differential ultracentrifugation. Infarct size was determined after 30 min global ischemia and 120 min reperfusion. The presence or absence of EVs in perfusates was confirmed by dynamic light scattering, the EV marker HSP60 Western blot, and electron microscopy. IPC markedly increased EV release from the heart as assessed by HSP60. Administration of coronary perfusate from IPC donor hearts attenuated infarct size in non-preconditioned recipient hearts (12.9 ± 1.6% vs. 25.0 ± 2.7%), similarly to cardioprotection afforded by IPC (7.3 ± 2.7% vs. 22.1 ± 2.9%) on the donor hearts. Perfusates of IPC hearts depleted of EVs failed to exert cardioprotection in recipient hearts (22.0 ± 2.3%). This is the first demonstration that EVs released from the heart after IPC are necessary for cardioprotection by RIPC, evidencing the importance of vesicular

  16. Principles of Antegrade Cerebral Perfusion During Arch Reconstruction in Newborns/Infants

    PubMed Central

    Fraser, Charles D.; Andropoulos, Dean B.

    2008-01-01

    Antegrade cerebral perfusion (ACP) is a cardiopulmonary bypass technique that uses special cannulation procedures to perfuse only the brain during neonatal and infant aortic arch reconstruction. It is used in lieu of deep hypothermic circulatory arrest (DHCA), and thus has the theoretical advantage of protecting the brain from hypoxic ischemic injury. Despite this, recent comparative studies have demonstrated no difference in neurodevelopmental outcomes with ACP vs. DHCA for neonatal arch repair. This article presents animal and human data demonstrating that ACP flows less than 30 ml/kg/min are inadequate for many patients, and may be the explanation for lack of outcome difference vs. DHCA. A technique for ACP, its physiologic basis, and a neuromonitoring strategy are presented, and then the results of an outcome study are reviewed demonstrating that with ACP technique at higher flows of 50–80 ml/kg/min guided by neuromonitoring, periventricular leukomalacia (PVL) is eliminated on postoperative brain MRI after neonatal cardiac surgery. PMID:18396227

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

    PubMed Central

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

    2015-01-01

    Rationale Collaterals lessen tissue injury in occlusive disease. However, aging causes progressive decline in their number and smaller diameters in those that remain (collateral rarefaction), beginning at 16 months-age in mice (ie, middle age), and worse ischemic injury—effects that are accelerated in even 3 months-old eNOS−/− mice. These findings have found indirect support in recent human studies. Objective We sought to determine if other cardiovascular risk factors (CVRFs) associated with endothelial dysfunction cause collateral rarefaction, investigate possible mechanisms, and test strategies for prevention. Methods and Results Mice with nine different models of CVRFs of 4–12 months-age were assessed for number and diameter of native collaterals in skeletal muscle and brain, and for collateral-dependent perfusion and ischemic injury after arterial occlusion. Hypertension caused collateral rarefaction whose severity increased with duration and level of hypertension, accompanied by greater hindlimb ischemia and cerebral infarct volume. Chronic treatment of wildtype mice with L-NG-nitro-arginine methylester caused similar rarefaction and worse ischemic injury that were not prevented by lowering arterial pressure with hydralazine. Metabolic syndrome, hypercholesterolemia, diabetes mellitus, and obesity also caused collateral rarefaction. Neither chronic statin treatment nor exercise training lessened hypertension-induced rarefaction. Conclusion Chronic CVRF presence caused collateral rarefaction and worse ischemic injury, even at relatively young ages. Rarefaction was associated with increased proliferation rate of collateral endothelial cells, effects that may promote accelerated endothelial cell senescence. PMID:25862671

  18. Therapeutic angiogenesis in ischemic muscles after local injection of fragmented fibers with loaded traditional Chinese medicine

    NASA Astrophysics Data System (ADS)

    Li, Huiyan; Wan, Huiying; Xia, Tian; Chen, Maohua; Zhang, Yun; Luo, Xiaoming; Li, Xiaohong

    2015-07-01

    Therapeutic angiogenesis remains the most effective method to re-establish a proper blood flow in ischemic tissues. There is a great clinical need to identify an injectable format to achieve a well accumulation following local administration and a sustained delivery of biological factors at the ischemic sites. In the current study, fragmented nanofibers with loaded traditional Chinese medicines, astragaloside IV (AT), the main active ingredient of astragalus, and ferulic acid (FA), the main ingredient of angelica, were proposed to promote the microvessel formation after intramuscular injection into ischemic hindlimbs. Fragmented fibers with average lengths of 5 (FF-5), 20 (FF-20) and 80 μm (FF-80) were constructed by the cryocutting of aligned electrospun fibers. Their dispersion in sodium alginate solution (0.2%) indicated good injectability. After injection into the quadriceps muscles of the hindlimbs, FF-20 and FF-80 fiber fragments showed higher tissue retentions than FF-5, and around 90% of the injected doses were determined after 7 days. On a hindlimb ischemia model established by ligating the femoral arteries, intramuscular injection of the mixtures of FA-loaded and AT-loaded FF-20 fiber fragments substantially reduced the muscle degeneration with minimal fibrosis formation, significantly enhanced the neovessel formation and hindlimb perfusion in the ischemic tissues, and efficiently promoted the limb salvage with few limb losses. Along with the easy manipulation and lower invasiveness for in vivo administration, fragmented fibers should become potential drug carriers for disease treatment, wound recovery and tissue repair after local injection.

  19. Promoting blood vessel growth in ischemic diseases: challenges in translating preclinical potential into clinical success

    PubMed Central

    Dragneva, Galina; Korpisalo, Petra; Ylä-Herttuala, Seppo

    2013-01-01

    Angiogenic therapy, which involves the use of an exogenous stimulus to promote blood vessel growth, is an attractive approach for the treatment of ischemic diseases. It has been shown in animal models that the stimulation of blood vessel growth leads to the growth of the whole vascular tree, improvement of ischemic tissue perfusion and improved muscle aerobic energy metabolism. However, very few positive results have been gained from Phase 2 and 3 clinical angiogenesis trials. Many reasons have been given for the failures of clinical trials, including poor transgene expression (in gene-therapy trials) and instability of the vessels induced by therapy. In this Review, we discuss the selection of preclinical models as one of the main reasons why clinical translation has been unsuccessful thus far. This issue has received little attention, but could have had dramatic implications on the expectations of clinical trials. We highlight crucial differences between human patients and animal models with regards to blood flow and pressure, as well as issues concerning the chronic nature of ischemic diseases in humans. We use these as examples to demonstrate why the results from preclinical trials might have overestimated the efficacy of angiogenic therapies developed to date. We also suggest ways in which currently available animal models of ischemic disease could be improved to better mimic human disease conditions, and offer advice on how to work with existing models to avoid overestimating the efficacy of new angiogenic therapies. PMID:23471910

  20. Does machine perfusion decrease ischemia reperfusion injury?

    PubMed

    Bon, D; Delpech, P-O; Chatauret, N; Hauet, T; Badet, L; Barrou, B

    2014-06-01

    In 1990's, use of machine perfusion for organ preservation has been abandoned because of improvement of preservation solutions, efficient without perfusion, easy to use and cheaper. Since the last 15 years, a renewed interest for machine perfusion emerged based on studies performed on preclinical model and seems to make consensus in case of expanded criteria donors or deceased after cardiac death donations. We present relevant studies highlighted the efficiency of preservation with hypothermic machine perfusion compared to static cold storage. Machines for organ preservation being in constant evolution, we also summarized recent developments included direct oxygenation of the perfusat. Machine perfusion technology also enables organ reconditioning during the last hours of preservation through a short period of perfusion on hypothermia, subnormothermia or normothermia. We present significant or low advantages for machine perfusion against ischemia reperfusion injuries regarding at least one primary parameter: risk of DFG, organ function or graft survival.

  1. Sodium efflux from perfused giant algal cells.

    PubMed

    Clint, G M; Macrobbie, E A

    1987-06-01

    Internodal cells of the giant alga Chara corallina were perfused internally to replace the native cytoplasm, tonoplast and vacuole with artificial cytoplasm. Sodium efflux from perfused cells, measured by including (22)Na in the perfusion media, was increased by increasing the internal sodium concentration and by decreasing the external pH, and was inhibited by external application of the renal diuretic amiloride. The sodium efflux was markedly ATP-dependent, with a 50-fold decrease in efflux observed after perfusion with media lacking ATP. Efflux in the presence of ATP was reduced by 33% by inclusion of 10 μM N,N'-dicyclohexylcarbodiimide in the perfusion medium. The membrane potential of the perfused cells approximated that of intact cells from the same culture. It is suggested that sodium efflux in perfused Chara cells proceeds via a secondary antiporter with protons, regulated by ATP in a catalytic role and with the proton motive force acting as the energy source.

  2. Radionuclide therapy for arthritic knees

    SciTech Connect

    Doepel, L.K.

    1985-02-08

    A new radionuclide therapeutic approach for rheumatoid arthritis of the knee is described. This therapy combines a short-lived radionuclide with a carrier whose physical and chemical characteristics aid retention of the radioactive particles within the joint. Joining a radionuclide to a particulate carrier had not been explored previously as a potential method for inhibiting radiation leakage. The treatment couples the rare earth element dysprosium 165 to ferric hydroxide in macroaggregate form (size range: 3 to 10 ..mu..m). After the relatively inert iron complex penetrates the synovium, it causes cell death. Macrophages and phagocytes clear away the cellular debris, essentially eliminating the synovium.

  3. In vivo perfusion assessment of an anastomosis surgery on porcine intestinal model (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Le, Hanh N. D.; Opferman, Justin; Decker, Ryan; Cheon, Gyeong W.; Kim, Peter C. W.; Kang, Jin U.; Krieger, Axel

    2016-04-01

    Anastomosis, the connection of two structures, is a critical procedure for reconstructive surgery with over 1 million cases/year for visceral indication alone. However, complication rates such as strictures and leakage affect up to 19% of cases for colorectal anastomoses and up to 30% for visceral transplantation anastomoses. Local ischemia plays a critical role in anastomotic complications, making blood perfusion an important indicator for tissue health and predictor for healing following anastomosis. In this work, we apply a real time multispectral imaging technique to monitor impact on tissue perfusion due to varying interrupted suture spacing and suture tensions. Multispectral tissue images at 470, 540, 560, 580, 670 and 760 nm are analyzed in conjunction with an empirical model based on diffuse reflectance process to quantify the hemoglobin oxygen saturation within the suture site. The investigated tissues for anastomoses include porcine small (jejunum and ileum) and large (transverse colon) intestines. Two experiments using interrupted suturing with suture spacing of 1, 2, and 3 mm and tension levels from 0 N to 2.5 N are conducted. Tissue perfusion at 5, 10, 20 and 30 min after suturing are recorded and compared with the initial normal state. The result indicates the contrast between healthy and ischemic tissue areas and assists the determination of suturing spacing and tension. Therefore, the assessment of tissue perfusion will permit the development and intra-surgical monitoring of an optimal suture protocol during anastomosis with less complications and improved functional outcome.

  4. Initial testing of a 3D printed perfusion phantom using digital subtraction angiography

    NASA Astrophysics Data System (ADS)

    Wood, Rachel P.; Khobragade, Parag; Ying, Leslie; Snyder, Kenneth; Wack, David; Bednarek, Daniel R.; Rudin, Stephen; Ionita, Ciprian N.

    2015-03-01

    Perfusion imaging is the most applied modality for the assessment of acute stroke. Parameters such as Cerebral Blood Flow (CBF), Cerebral Blood volume (CBV) and Mean Transit Time (MTT) are used to distinguish the tissue infarct core and ischemic penumbra. Due to lack of standardization these parameters vary significantly between vendors and software even when provided with the same data set. There is a critical need to standardize the systems and make them more reliable. We have designed a uniform phantom to test and verify the perfusion systems. We implemented a flow loop with different flow rates (250, 300, 350 ml/min) and injected the same amount of contrast. The images of the phantom were acquired using a Digital Angiographic system. Since this phantom is uniform, projection images obtained using DSA is sufficient for initial validation. To validate the phantom we measured the contrast concentration at three regions of interest (arterial input, venous output, perfused area) and derived time density curves (TDC). We then calculated the maximum slope, area under the TDCs and flow. The maximum slope calculations were linearly increasing with increase in flow rate, the area under the curve decreases with increase in flow rate. There was 25% error between the calculated flow and measured flow. The derived TDCs were clinically relevant and the calculated flow, maximum slope and areas under the curve were sensitive to the measured flow. We have created a systematic way to calibrate existing perfusion systems and assess their reliability.

  5. Spontaneous changes in /sup 201/Tl myocardial perfusion imaging after myocardial infarction

    SciTech Connect

    Buda, A.J.; Dubbin, J.D.; MacDonald, I.L.; Strauss, H.D.; Orr, S.A.; Meindok, H.

    1982-12-01

    To examine regional myocardial perfusion after myocardial infarction, 26 patients underwent exercise electrocardiographic testing with /sup 201/Tl myocardial perfusion imaging 3 weeks and 3 months after infarction. At 3 weeks, 9 of 26 patients (35%) had myocardial ischemia by exercise electrocardiographic testing, whereas 18 of 26 (69%) had ischemia by /sup 201/Tl imaging. The /sup 201/Tl scintigrams were scored by dividing each image, in 3 views, into 5 segments, using a 5-point scoring scheme. The exercise /sup 201/Tl score was 44.3 +/- 1.2 and increased to 47.3 +/- 1.2 in the redistribution study (p less than 0.001). Three months after infarction, although there was a significantly greater rate-pressure product which would predict a larger ischemic defect and a decrease in the stress /sup 201/Tl score, the stress score was improved (48.3 +/- 1.1, p less than 0.001). The redistribution score was similar, that is, 48.9 +/- 1.0. The improvement in /sup 201/Tl myocardial perfusion was associated with a loss of stress-induced ischemia in 8 patients (30%). These results indicate that spontaneous improvements in /sup 201/Tl myocardial perfusion imaging may occur after myocardial infarction.

  6. AUGMENTATION OF LIMB PERFUSION AND REVERSAL OF TISSUE ISCHEMIA PRODUCED BY ULTRASOUND-MEDIATED MICROBUBBLE CAVITATION

    PubMed Central

    Belcik, J. Todd; Mott, Brian H.; Xie, Aris; Zhao, Yan; Kim, Sajeevani; Lindner, Nathan J.; Ammi, Azzdine; Linden, Joel M.; Lindner, Jonathan R.

    2015-01-01

    Background Ultrasound can increase tissue blood flow in part through the intravascular shear produced by oscillatory pressure fluctuations. We hypothesized that ultrasound-mediated increases in perfusion can be augmented by microbubble contrast agents that undergo ultrasound-mediated cavitation, and sought to characterize the biologic mediators. Methods and Results Contrast ultrasound perfusion imaging of hindlimb skeletal muscle and femoral artery diameter measurement were performed in non-ischemic mice after unilateral 10 min exposure to intermittent ultrasound alone (mechanical index [MI] 0.6 or 1.3) or ultrasound with lipid microbubbles (2×108 I.V.). Studies were also performed after inhibiting shear- or pressure-dependent vasodilator pathways, and in mice with hindlimb ischemia. Ultrasound alone produced a 2-fold increase (p<0.05) in muscle perfusion regardless of ultrasound power. Ultrasound-mediated augmentation in flow was greater with microbubbles (3-fold and 10-fold higher than control for MI 0.6 and 1.3, respectively; p<0.05), as was femoral artery dilation. Inhibition of endothelial nitric oxide synthase (eNOS) attenuated flow augmentation produced by ultrasound and microbubbles by 70% (p<0.01), whereas inhibition of adenosine-A2a receptors and epoxyeicosatrienoic acids had minimal effect. Limb nitric oxide (NO) production and muscle phospho-eNOS increased in a stepwise fashion by ultrasound and ultrasound with microbubbles. In mice with unilateral hindlimb ischemia (40–50% reduction in flow), ultrasound (MI 1.3) with microbubbles increased perfusion by 2-fold to a degree that was greater than the control non-ischemic limb. Conclusions Increases in muscle blood flow during high-power ultrasound are markedly amplified by the intravascular presence of microbubbles and can reverse tissue ischemia. These effects are most likely mediated by cavitation-related increases in shear and activation of eNOS. PMID:25834183

  7. Diffusion–Perfusion Mismatch: An Opportunity for Improvement in Cortical Function

    PubMed Central

    Motta, Melissa; Ramadan, Amanda; Hillis, Argye E.; Gottesman, Rebecca F.; Leigh, Richard

    2015-01-01

    Objective: There has been controversy over whether diffusion–perfusion mismatch provides a biomarker for the ischemic penumbra. In the context of clinical stroke trials, regions of the diffusion–perfusion mismatch that do not progress to infarct in the absence of reperfusion are considered to represent “benign oligemia.” However, at least in some cases (particularly large vessel stenosis), some of this hypoperfused tissue may remain dysfunctional for a prolonged period without progressing to infarct and may recover function if eventually reperfused. We hypothesized that patients with persistent diffusion–perfusion mismatch using a hypoperfusion threshold of 4–5.9 s delay on time-to-peak (TTP) maps at least sometimes have persistent cognitive deficits relative to those who show some reperfusion of this hypoperfused tissue. Methods: We tested this hypothesis in 38 patients with acute ischemic stroke who had simple cognitive tests (naming or line cancelation) and MRI with diffusion and perfusion imaging within 24 h of onset and again within 10 days, most of whom had large vessel stenosis or occlusion. Results: A persistent perfusion deficit of 4–5.9 s delay in TTP on follow up MRI was associated with a persistent cognitive deficit at that time point (p < 0.001). When we evaluated only patients who did not have infarct growth (n = 14), persistent hypoperfusion (persistent mismatch) was associated with a lack of cognitive improvement compared with those who had reperfused. The initial volume of hypoperfusion did not correlate with the later infarct volume (progression to infarct), but change in volume of hypoperfusion correlated with change in cognitive performance (p = 0.0001). Moreover, multivariable regression showed that the change in volume of hypoperfused tissue of 4–5.9 s delay (p = 0.002), and change in volume of ischemic tissue on diffusion weighted imaging (p = 0.02) were independently associated with change in

  8. Subendocardial segment length shortening at lateral margins of ischemic myocardium in dogs

    SciTech Connect

    Gallagher, K.P.; Gerren, R.A.; Choy, M.; Stirling, M.C.; Dysko, R.C. )

    1987-10-01

    The lateral borders of an infarcted area are sharply delineated in terms of perfusion, but functional impairment extends a limited distance into adjacent nonischemic myocardium. To determine the distribution of functional impairment the authors arrayed three ultrasonic dimension gauges to measure two subendocardial segment lengths in series. The center crystal, placed at the perfusion boundary (PB) between left anterior descending and circumflex arteries, radiated ultrasound to receiver crystals 7-17 mm to either side of the PB. The locations of the functional measurements relative to the PB were determined with myocardial blood flow (tracer-labeled microsphere) maps constructed from multiple small tissue samples obtained circumferentially. On the ischemic side of the PB, dL decreased from 2.24 {plus minus} 0.54 to 0.42 {plus minus} 0.39 mm. By adding the data from the two segments in series, a combined measurement of dL across heterogeneously perfused myocardium was derived that decreased by 38% from control. The level of shortening represented an integral of normal and abnormal motion that was proportional to the mean reduction in blood flow ({minus}44%) in all of the muscle spanned by the crystals. They conclude that subendocardial segment lengths average shortening in the muscle they subtend when arrayed across the perfusion boundary.

  9. Distribution of lung blood on modified bilateral Glenn shunt evaluated by Tc-99m-MAA lung perfusion scintigraphy

    PubMed Central

    Si, Biao; Luan, Zhao-sheng; Wang, Tong-jian; Ning, Yan-song; Li, Na; Zhu, Meng; Liu, Zhong-min; Ding, Guang-hong; Qiao, Bin

    2016-01-01

    Abstract The aim of the present study was to determine the distribution of lung blood in a modified bilateral Glenn procedure designed in our institute with lung perfusion scintigraphy. Sixteen consecutive patients who underwent modified bilateral Glenn operation from 2011 to 2014 were enrolled in the study. The control group consisted of 7 patients who underwent bidirectional Glenn shunt. Radionuclide lung perfusion scintigraphy was performed using Tc-99m-macro aggregated albumin (MAA) in all patients. For the patients in modified bilateral Glenn group, the time at which the radioactivity accumulation peaked did not differ significantly between the right and left lung field (t = 0.608, P = 0.554). The incidence of perfusion abnormality in each lung lobe also did not differ significantly (P = 0.426 by Fisher exact test). The radioactive counts were higher in the right lung than in the left lung, but the difference was not statistically significant (t = 1.502, P = 0.157). Radioactive perfusion in the lower lung field was significantly greater than that in the upper field (t = 4.368, P < 0.001). Compared with that in the bidirectional Glenn group, the ratio of radioactivity in the right lung to that in left lung was significantly lower in the modified bilateral Glenn group (t = 3.686, P = 0.002). Lung perfusion scintigraphy confirmed the benefit of the modified bilateral Glenn shunt with regard to more balanced blood perfusion in both lungs. PMID:27661042

  10. Radionuclide Retention in Concrete Wasteforms

    SciTech Connect

    Bovaird, Chase C.; Jansik, Danielle P.; Wellman, Dawn M.; Wood, Marcus I.

    2011-09-30

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. The information present in the report provides data that (1) measures the effect of concrete wasteform properties likely to influence radionuclide migration; and (2) quantifies the rate of carbonation of concrete materials in a simulated vadose zone repository.

  11. Drift-Scale Radionuclide Transport

    SciTech Connect

    J. Houseworth

    2004-09-22

    The purpose of this model report is to document the drift scale radionuclide transport model, taking into account the effects of emplacement drifts on flow and transport in the vicinity of the drift, which are not captured in the mountain-scale unsaturated zone (UZ) flow and transport models ''UZ Flow Models and Submodels'' (BSC 2004 [DIRS 169861]), ''Radionuclide Transport Models Under Ambient Conditions'' (BSC 2004 [DIRS 164500]), and ''Particle Tracking Model and Abstraction of Transport Process'' (BSC 2004 [DIRS 170041]). The drift scale radionuclide transport model is intended to be used as an alternative model for comparison with the engineered barrier system (EBS) radionuclide transport model ''EBS Radionuclide Transport Abstraction'' (BSC 2004 [DIRS 169868]). For that purpose, two alternative models have been developed for drift-scale radionuclide transport. One of the alternative models is a dual continuum flow and transport model called the drift shadow model. The effects of variations in the flow field and fracture-matrix interaction in the vicinity of a waste emplacement drift are investigated through sensitivity studies using the drift shadow model (Houseworth et al. 2003 [DIRS 164394]). In this model, the flow is significantly perturbed (reduced) beneath the waste emplacement drifts. However, comparisons of transport in this perturbed flow field with transport in an unperturbed flow field show similar results if the transport is initiated in the rock matrix. This has led to a second alternative model, called the fracture-matrix partitioning model, that focuses on the partitioning of radionuclide transport between the fractures and matrix upon exiting the waste emplacement drift. The fracture-matrix partitioning model computes the partitioning, between fractures and matrix, of diffusive radionuclide transport from the invert (for drifts without seepage) into the rock water. The invert is the structure constructed in a drift to provide the floor of the

  12. Tissue pertechnetate and iodinated contrast material ischemic stroke

    SciTech Connect

    Anderson, D.C.; Coss, D.T.; Jacobson, R.L.; Meyer, M.W.

    1980-11-01

    Isotope uptake during static radionuclide scanning and contrast enhancement during CT scanning, which may result from similar pathophysiologic mechanisms after ischemic infarction, were investigated in an animal model. Infarction was produced by transorbital occlusion of the middle cerebral artery in cats killed one, 2, 4, 8, or 16 days later. Sodium pertechnetate containing technetium-99m and 30% methylglucamine iothalamate labeled with I-125 were administered intravenously 60 and 15 min respectively prior to sacrifice. A coronal section through the infarct was parceled into 30 portions which were assayed for concentration of each isotope. Adjacent brain was prepared for histopathologic correlation. Concentrations of the 2 materials were highest in infarcted brain at 4 and 8 days. Strong positive correlation was found between tissue concentrations of the 2 materials in all brain samples. Elevated tissue levels correlated with necrosis, macrophage infiltration, and vascular hyperplasia. The results support the probability that radionuclide scan positivity and CT contrast enhancement reflect the same pathophysiologic development, probably extravasation of the respective labels, after schemic stroke.

  13. Arterial spin labeling-fast imaging with steady-state free precession (ASL-FISP): a rapid and quantitative perfusion technique for high-field MRI.

    PubMed

    Gao, Ying; Goodnough, Candida L; Erokwu, Bernadette O; Farr, George W; Darrah, Rebecca; Lu, Lan; Dell, Katherine M; Yu, Xin; Flask, Chris A

    2014-08-01

    Arterial spin labeling (ASL) is a valuable non-contrast perfusion MRI technique with numerous clinical applications. Many previous ASL MRI studies have utilized either echo-planar imaging (EPI) or true fast imaging with steady-state free precession (true FISP) readouts, which are prone to off-resonance artifacts on high-field MRI scanners. We have developed a rapid ASL-FISP MRI acquisition for high-field preclinical MRI scanners providing perfusion-weighted images with little or no artifacts in less than 2 s. In this initial implementation, a flow-sensitive alternating inversion recovery (FAIR) ASL preparation was combined with a rapid, centrically encoded FISP readout. Validation studies on healthy C57/BL6 mice provided consistent estimation of in vivo mouse brain perfusion at 7 and 9.4 T (249 ± 38 and 241 ± 17 mL/min/100 g, respectively). The utility of this method was further demonstrated in the detection of significant perfusion deficits in a C57/BL6 mouse model of ischemic stroke. Reasonable kidney perfusion estimates were also obtained for a healthy C57/BL6 mouse exhibiting differential perfusion in the renal cortex and medulla. Overall, the ASL-FISP technique provides a rapid and quantitative in vivo assessment of tissue perfusion for high-field MRI scanners with minimal image artifacts.

  14. Ischemic preconditioning enhances integrity of coronary endothelial tight junctions

    SciTech Connect

    Li, Zhao; Jin, Zhu-Qiu

    2012-08-31

    Highlights: Black-Right-Pointing-Pointer Cardiac tight junctions are present between coronary endothelial cells. Black-Right-Pointing-Pointer Ischemic preconditioning preserves the structural and functional integrity of tight junctions. Black-Right-Pointing-Pointer Myocardial edema is prevented in hearts subjected to ischemic preconditioning. Black-Right-Pointing-Pointer Ischemic preconditioning enhances translocation of ZO-2 from cytosol to cytoskeleton. -- Abstract: Ischemic preconditioning (IPC) is one of the most effective procedures known to protect hearts against ischemia/reperfusion (IR) injury. Tight junction (TJ) barriers occur between coronary endothelial cells. TJs provide barrier function to maintain the homeostasis of the inner environment of tissues. However, the effect of IPC on the structure and function of cardiac TJs remains unknown. We tested the hypothesis that myocardial IR injury ruptures the structure of TJs and impairs endothelial permeability whereas IPC preserves the structural and functional integrity of TJs in the blood-heart barrier. Langendorff hearts from C57BL/6J mice were prepared and perfused with Krebs-Henseleit buffer. Cardiac function, creatine kinase release, and myocardial edema were measured. Cardiac TJ function was evaluated by measuring Evans blue-conjugated albumin (EBA) content in the extravascular compartment of hearts. Expression and translocation of zonula occludens (ZO)-2 in IR and IPC hearts were detected with Western blot. A subset of hearts was processed for the observation of ultra-structure of cardiac TJs with transmission electron microscopy. There were clear TJs between coronary endothelial cells of mouse hearts. IR caused the collapse of TJs whereas IPC sustained the structure of TJs. IR increased extravascular EBA content in the heart and myocardial edema but decreased the expression of ZO-2 in the cytoskeleton. IPC maintained the structure of TJs. Cardiac EBA content and edema were reduced in IPC hearts. IPC

  15. Arterial ischemic stroke in HIV

    PubMed Central

    Bryer, Alan; Lucas, Sebastian; Stanley, Alan; Allain, Theresa J.; Joekes, Elizabeth; Emsley, Hedley; Turnbull, Ian; Downey, Colin; Toh, Cheng-Hock; Brown, Kevin; Brown, David; Ison, Catherine; Smith, Colin; Corbett, Elizabeth L.; Nath, Avindra; Heyderman, Robert S.; Connor, Myles D.; Solomon, Tom

    2016-01-01

    HIV infection, and potentially its treatment, increases the risk of an arterial ischemic stroke. Multiple etiologies and lack of clear case definitions inhibit progress in this field. Several etiologies, many treatable, are relevant to HIV-related stroke. To fully understand the mechanisms and the terminology used, a robust classification algorithm to help ascribe the various etiologies is needed. This consensus paper considers the strengths and limitations of current case definitions in the context of HIV infection. The case definitions for the major etiologies in HIV-related strokes were refined (e.g., varicella zoster vasculopathy and antiphospholipid syndrome) and in some instances new case definitions were described (e.g., HIV-associated vasculopathy). These case definitions provided a framework for an algorithm to help assign a final diagnosis, and help classify the subtypes of HIV etiology in ischemic stroke. PMID:27386505

  16. Anthropogenic radionuclides in the environment

    SciTech Connect

    Hu, Q; Weng, J; Wang, J

    2007-11-15

    Studies of radionuclides in the environment have entered a new era with the renaissance of nuclear energy and associated fuel reprocessing, geological disposal of high-level nuclear wastes, and concerns about national security with respect to nuclear non-proliferation. This work presents an overview of anthropogenic radionuclide contamination in the environment, as well as the salient geochemical behavior of important radionuclides. We first discuss the following major anthropogenic sources and current development that contribute to the radionuclide contamination of the environment: (1) nuclear weapons program; (2) nuclear weapons testing; (3) nuclear power plants; (4) commercial fuel reprocessing; (5) geological repository of high-level nuclear wastes, and (6) nuclear accidents. Then, we summarize the geochemical behavior for radionuclides {sup 99}Tc, {sup 129}I, and {sup 237}Np, because of their complex geochemical behavior, long half-lives, and presumably high mobility in the environment. Biogeochemical cycling and environment risk assessment must take into account speciation of these redox-sensitive radionuclides.

  17. Hyperacute management of ischemic stroke.

    PubMed

    Song, Sarah

    2013-11-01

    Stroke is a devastating disease and currently the fourth leading cause of death in this country. Acute ischemic stroke is an emergency and requires effective triage, diagnosis, and critical management. The hyperacute management of ischemic stroke begins in the field, with recognition of stroke symptoms by emergency medical systems (EMS) personnel. The EMS is an important component to an effective stroke system of care, which also includes primary stroke centers, routing protocols for acute ischemic stroke, and telemedicine. Following the arrival of a potential stroke patient to the emergency room setting, patients should be stabilized and undergo assessment for potential intravenous alteplase (IV tPA) treatment. Assessments include diagnostic tests, neuroimaging, and standardized stroke evaluations. After these assessments have been performed, IV tPA, the only medication for acute stroke approved by the U.S. Food and Drug Administration, can be considered using a variety of inclusion and exclusion criteria. Previously time restrictions limited the usage of IV tPA to 3 hours, but this time window has now been extended for eligible candidates to 4.5 hours. The administration of IV tPA has specific requirements for monitoring and should be standardized via protocol across hospitals.

  18. [Ischemic cerebrovascular accidents in childhood].

    PubMed

    Pascual Pascual, S I; Pascual Castroviejo, I; Vélez, A

    1988-04-01

    Authors review 53 children, aged 0 to 14 years, affected with cerebrovascular ischemic strokes. Largest aetiological groups were: a) congenital heart disease, 16 patients; b) arteritis of unknown cause, 11; c) idiopathic arterial occlusion without arteritis images on angiography, 7; d) moyamoya disease, 6; and d) local or systemic infections, 5. The mode of onset was as completed stroke in 72% and stroke in evolution in 24%. After acute stage 17.6% of patients presented other definitive strokes, 11.7% suffered only transient ischemic strokes (TIA), and 4% reversible ischemic neurologic deficits (RIND). Mean follow-up was 4.36 years, 9.8% of patients died, 11.8% recovered completely and 52.9% improved after initial stroke. Poor global evolution was associated with heart disease (p less than 0.05) and with onset of strokes before age 2 (p less than 0.05). Most important sequelae, besides motor impairment, were epilepsy (49%) and mental retardation (50% got less than IQ 80). Late epilepsy was associated with seizures at onset (p less than 0.05). Clinical factors of adverse mental development were: a) seizures at onset, b) late epilepsy and c) stroke before age 2. 66% of cases had two or more arterial lesions in the same or in different arterial trees. Therefore, embolic and arteritic factors probably play an important role in infancy and childhood stroke. PMID:3400936

  19. Intestinal perfusion monitoring using photoplethysmography

    NASA Astrophysics Data System (ADS)

    Akl, Tony J.; Wilson, Mark A.; Ericson, M. Nance; Coté, Gerard L.

    2013-08-01

    In abdominal trauma patients, monitoring intestinal perfusion and oxygen consumption is essential during the resuscitation period. Photoplethysmography is an optical technique potentially capable of monitoring these changes in real time to provide the medical staff with a timely and quantitative measure of the adequacy of resuscitation. The challenges for using optical techniques in monitoring hemodynamics in intestinal tissue are discussed, and the solutions to these challenges are presented using a combination of Monte Carlo modeling and theoretical analysis of light propagation in tissue. In particular, it is shown that by using visible wavelengths (i.e., 470 and 525 nm), the perfusion signal is enhanced and the background contribution is decreased compared with using traditional near-infrared wavelengths leading to an order of magnitude enhancement in the signal-to-background ratio. It was further shown that, using the visible wavelengths, similar sensitivity to oxygenation changes could be obtained (over 50% compared with that of near-infrared wavelengths). This is mainly due to the increased contrast between tissue and blood in that spectral region and the confinement of the photons to the thickness of the small intestine. Moreover, the modeling results show that the source to detector separation should be limited to roughly 6 mm while using traditional near-infrared light, with a few centimeters source to detector separation leads to poor signal-to-background ratio. Finally, a visible wavelength system is tested in an in vivo porcine study, and the possibility of monitoring intestinal perfusion changes is showed.

  20. Prediction of Revascularization after Myocardial Perfusion SPECT by Machine Learning in a Large Population

    PubMed Central

    Arsanjani, Reza; Dey, Damini; Khachatryan, Tigran; Shalev, Aryeh; Hayes, Sean W.; Fish, Mathews; Nakanishi, Rine; Germano, Guido; Berman, Daniel S.; Slomka, Piotr

    2016-01-01

    Objective We aimed to investigate if early revascularization in patients with suspected coronary artery disease (CAD) can be effectively predicted by integrating clinical data and quantitative image features derived from perfusion SPECT (MPS) by machine learning (ML) approach. Methods 713 rest 201Thallium/stress 99mTechnetium MPS studies with correlating invasive angiography (372 revascularization events (275 PCI / 97 CABG) within 90 days after MPS (91% within 30 days) were considered. Transient ischemic dilation (TID), stress combined supine/prone total perfusion deficit (TPD), quantitative rest and stress TPD, exercise ejection fraction, and end-systolic volume along with clinical parameters including patient gender, history of hypertension and diabetes mellitus, ST-depression on baseline ECG, ECG and clinical response during stress, and post-ECG probability by boosted ensemble ML algorithm (LogitBoost) to predict revascularization events. These features were selected using an automated feature selection algorithm from all available clinical and quantitative data (33 parameters). 10-fold cross-validation was utilized to train and test the prediction model. The prediction of revascularization by ML algorithm was compared to standalone measures of perfusion and visual analysis by two experienced readers utilizing all imaging, quantitative, and clinical data. Results The sensitivity of machine learning (73.6±4.3%) for prediction of revascularization was similar to one reader (73.9±4.6%) and standalone measures of perfusion (75.5±4.5%). The specificity of machine learning (74.7±4.2%) was also better than both expert readers (67.2±4.9% and 66.0±5.0%, P < 0.05), but was similar to ischemic TPD (68.3±4.9%, P < 0.05). The Receiver-Operator-Characteristics areas-under-curve for machine learning (0.81±0.02) was similar to reader 1 (0.81±0.02) but superior to reader 2 (0.72±0.02, P < 0.01) and standalone measure of perfusion (0.77±0.02, P < 0.01). Conclusion ML

  1. Functional recovery of hibernating myocardium after coronary bypass surgery: Does it coincide with improvement in perfusion

    SciTech Connect

    Takeishi, Y.; Tono-oka, I.; Kubota, I.; Ikeda, K.; Masakane, I.; Chiba, J.; Abe, S.; Tsuiki, K.; Komatani, A.; Yamaguchi, I. )

    1991-09-01

    To determine the relationship between functional recovery and improvement in perfusion after coronary artery bypass graft surgery (CABG), 49 patients were studied. Radionuclide angiography was performed before, 1 month after, and 6 to 12 months after CABG to evaluate regional wall motion. Exercise thallium-201 myocardial perfusion imaging was done before and 1 month after CABG to assess regional perfusion. Preoperative asynergy was observed in 108 segments, and 74 of them showed an improvement in wall motion 1 month after CABG (segment A). Sixty-six of these segments (89%) were associated with an improvement in perfusion. Eight segments that had not improved 1 month after CABG demonstrated a delayed recovery of wall motion 6 to 12 months after CABG (segment B). However, seven of eight segments (88%) already showed an improvement in perfusion 1 month after CABG. A total of 82 segments exhibited functional recovery after CABG and were considered hibernating segments. In the preoperative study segment B more frequently had areas of akinesis or dyskinesis than segment A (75% vs 34%, p less than 0.05). The mean percent thallium-201 uptake in segment B was lower than that in segment A (74% {plus minus} 9% vs 83% {plus minus} 8%, p less than 0.05). Functional recovery of hibernating myocardium usually coincided with an improvement in perfusion. However, delayed functional recovery after reperfusion was observed in some instances. Severe asynergy and severe thallium-201 defects were more frequently observed in these segments with delayed recovery. Hibernating myocardium might remain stunned during those recovery periods.

  2. Echocardiographic assessment of ischemic mitral regurgitation.

    PubMed

    Dudzinski, David M; Hung, Judy

    2014-01-01

    Ischemic mitral regurgitation is an important consequence of LV remodeling after myocardial infarction. Echocardiographic diagnosis and assessment of ischemic mitral regurgitation are critical to gauge its adverse effects on prognosis and to attempt to tailor rational treatment strategy. There is no single approach to the echocardiographic assessment of ischemic mitral regurgitation: standard echocardiographic measures of mitral regurgitation severity and of LV dysfunction are complemented by assessments of displacement of the papillary muscles and quantitative indices of mitral valve deformation. Development of novel approaches to understand mitral valve geometry by echocardiography may improve understanding of the mechanism, clinical trajectory, and reparability of ischemic mitral regurgitation.

  3. Ultrasound perfusion signal processing for tumor detection

    NASA Astrophysics Data System (ADS)

    Kim, MinWoo; Abbey, Craig K.; Insana, Michael F.

    2016-04-01

    Enhanced blood perfusion in a tissue mass is an indication of neo-vascularity and a sign of a potential malignancy. Ultrasonic pulsed-Doppler imaging is a preferred modality for noninvasive monitoring of blood flow. However, the weak blood echoes and disorganized slow flow make it difficult to detect perfusion using standard methods without the expense and risk of contrast enhancement. Our research measures the efficiency of conventional power-Doppler (PD) methods at discriminating flow states by comparing measurement performance to that of an ideal discriminator. ROC analysis applied to the experimental results shows that power Doppler methods are just 30-50 % efficient at perfusion flows less than 1ml/min, suggesting an opportunity to improve perfusion assessment through signal processing. A new perfusion estimator is proposed by extending the statistical discriminator approach. We show that 2-D perfusion color imaging may be enhanced using this approach.

  4. Semi-quantitative assessment of tibial blood flow and distribution in response to surgical intervention using first pass radionuclide angiography and intravascular vital dye.

    PubMed

    Field, J R; Lord, P; Maaripuu, E; Sumner-Smith, G

    1999-12-01

    The acute vascular response in bone to surgical trauma was investigated utilizing a sheep model. Blood flow and distribution were determined using two methods; perfusion of the vasculature with an intravascular vital dye (Disulphine blue) prior to euthanasia and by radionuclide angiography (RNA) before and after each surgical intervention. The pattern of Disulphine blue distribution provided a good indication of local perfusion and response to surgical trauma (drilling holes). Radionuclide angiography provided a dynamic image of the vascular response to surgical trauma. The generation of time activity curves of the first pass of radionuclide bolus enabled calculation of the relative blood flow through selected regions. For both techniques areas of ischaemia were apparent which were directly related to the location of screw holes. We conclude that factors other than bone plate contact influence the ischaemia that develops in bone subsequent to the application of bone plates.

  5. The cerebral imaging using vessel-around method in the perfusion CT of the human brain

    NASA Astrophysics Data System (ADS)

    Ahn, Choong-Il; Choi, Seung-Wook; Park, Seung-Chul; Shin, Yeong-Gil; Kim, Jae-Hyoung; Chong, Gi-Bong

    2005-04-01

    Perfusion CT has been successfully used as a functional imaging technique for diagnosis of patients with hyperacute stroke. However, the commonly used methods based on curve-fitting are time consuming. Numerous researchers have investigated to what extent Perfusion CT can be used for the quantitative assessment of cerebral ischemia and to rapidly obtain comprehensive information regarding the extent of ischemic damage in acute stroke patients. The aim of this study is to propose an alternative approach to rapidly obtain the brain perfusion mapping and to show the proposed cerebral flow imaging of the vessel and tissue in human brain be reliable and useful. Our main design concern was algorithmic speed, robustness and automation in order to allow its potential use in the emergency situation of acute stroke. To obtain a more effective mapping, we analyzed the signal characteristics of Perfusion CT and defined the vessel-around model which includes the vessel and tissue. We proposed a nonparametric vessel-around approach which automatically discriminates the vessel and tissue around vessel from non-interested brain matter stratifying the level of maximum enhancement of pixel-based TAC. The stratification of pixel-based TAC was executed using the mean and standard deviation of the signal intensity of each pixel and mapped to the cerebral flow imaging. The defined vessel-around model was used to show the cerebral flow imaging and to specify the area of markedly reduced perfusion with loss of function of still viable neurons. Perfusion CT is a fast and practical technique for routine clinical application. It provides substantial and important additional information for the selection of the optimal treatment strategy for patients with hyperacute stroke. The vessel-around approach reduces the computation time significantly when compared with the perfusion imaging using the GVF. The proposed cerebral imaging shows reliable results which are validated by physicians and

  6. Intravenous Administration of Endothelial Colony-Forming Cells Overexpressing Integrin β1 Augments Angiogenesis in Ischemic Legs.

    PubMed

    Goto, Kazuko; Takemura, Genzou; Takahashi, Tomoyuki; Okada, Hideshi; Kanamori, Hiromitsu; Kawamura, Itta; Watanabe, Takatomo; Morishita, Kentaro; Tsujimoto, Akiko; Miyazaki, Nagisa; Ushikoshi, Hiroaki; Kawasaki, Masanori; Mikami, Atsushi; Kosai, Ken-ichiro; Minatoguchi, Shinya

    2016-02-01

    When injected directly into ischemic tissue in patients with peripheral artery disease, the reparative capacity of endothelial progenitor cells (EPCs) appears to be limited by their poor survival. We, therefore, attempted to improve the survival of transplanted EPCs through intravenous injection and gene modification. We anticipated that overexpression of integrin β1 will enable injected EPCs to home to ischemic tissue, which abundantly express extracellular matrix proteins, the ligands for integrins. In addition, integrin β1 has an independent angiogenesis-stimulating function. Human endothelial colony-forming cells (ECFCs; late-outgrowth EPCs) were transduced using a lentiviral vector encoding integrin β1 (ITGB1) or enhanced green fluorescent protein (GFP). We then locally or systemically injected phosphate-buffered saline or the genetically modified ECFCs (GFP-ECFCs or ITGB1-ECFCs; 1 × 10(5) cells each) into NOD/Shi-scid, IL-2Rγnull mice whose right femoral arteries had been occluded 24 hours earlier. Upregulation of extracellular matrix proteins, including fibronectin, was apparent in the ischemic legs. Four weeks later, blood perfusion of the ischemic limb was significantly augmented only in the ITGB1-ECFC group. Scanning electron microscopy of vascular casts revealed increases in the perfused blood vessels in the ischemic legs of mice in the ITGB1-ECFC group and significant increases in the density of both capillaries and arterioles. Transplanted ECFC-derived vessels accounted for 28% ± 4.2% of the vessels in the ITGB1-ECFC group, with no cell fusion. Intravenous administration of ECFCs engineered to home to ischemic tissue appears to efficiently mediate therapeutic angiogenesis in a mouse model of peripheral artery disease. Significance: The intravenous administration of endothelial colony-forming cells (ECFCs) genetically modified to overexpress integrin β1 effectively stimulated angiogenesis in ischemic mouse hindlimbs. Transplanted ECFCs were

  7. Intravenous Administration of Endothelial Colony-Forming Cells Overexpressing Integrin β1 Augments Angiogenesis in Ischemic Legs.

    PubMed

    Goto, Kazuko; Takemura, Genzou; Takahashi, Tomoyuki; Okada, Hideshi; Kanamori, Hiromitsu; Kawamura, Itta; Watanabe, Takatomo; Morishita, Kentaro; Tsujimoto, Akiko; Miyazaki, Nagisa; Ushikoshi, Hiroaki; Kawasaki, Masanori; Mikami, Atsushi; Kosai, Ken-ichiro; Minatoguchi, Shinya

    2016-02-01

    When injected directly into ischemic tissue in patients with peripheral artery disease, the reparative capacity of endothelial progenitor cells (EPCs) appears to be limited by their poor survival. We, therefore, attempted to improve the survival of transplanted EPCs through intravenous injection and gene modification. We anticipated that overexpression of integrin β1 will enable injected EPCs to home to ischemic tissue, which abundantly express extracellular matrix proteins, the ligands for integrins. In addition, integrin β1 has an independent angiogenesis-stimulating function. Human endothelial colony-forming cells (ECFCs; late-outgrowth EPCs) were transduced using a lentiviral vector encoding integrin β1 (ITGB1) or enhanced green fluorescent protein (GFP). We then locally or systemically injected phosphate-buffered saline or the genetically modified ECFCs (GFP-ECFCs or ITGB1-ECFCs; 1 × 10(5) cells each) into NOD/Shi-scid, IL-2Rγnull mice whose right femoral arteries had been occluded 24 hours earlier. Upregulation of extracellular matrix proteins, including fibronectin, was apparent in the ischemic legs. Four weeks later, blood perfusion of the ischemic limb was significantly augmented only in the ITGB1-ECFC group. Scanning electron microscopy of vascular casts revealed increases in the perfused blood vessels in the ischemic legs of mice in the ITGB1-ECFC group and significant increases in the density of both capillaries and arterioles. Transplanted ECFC-derived vessels accounted for 28% ± 4.2% of the vessels in the ITGB1-ECFC group, with no cell fusion. Intravenous administration of ECFCs engineered to home to ischemic tissue appears to efficiently mediate therapeutic angiogenesis in a mouse model of peripheral artery disease. Significance: The intravenous administration of endothelial colony-forming cells (ECFCs) genetically modified to overexpress integrin β1 effectively stimulated angiogenesis in ischemic mouse hindlimbs. Transplanted ECFCs were

  8. Prediction of postoperative pulmonary function following thoracic operations. Value of ventilation-perfusion scanning

    SciTech Connect

    Bria, W.F.; Kanarek, D.J.; Kazemi, H.

    1983-08-01

    Surgical resection of lung cancer is frequently required in patients with severely impaired lung function resulting from chronic obstructive pulmonary disease. Twenty patients with obstructive lung disease and cancer (mean preoperative forced expiratory volume in 1 second (FEV1) . 1.73 L) were studied preoperatively and postoperatively by spirometry and radionuclide perfusion, single-breath ventilation, and washout techniques to test the ability of these methods to predict preoperatively the partial loss of lung function by the resection. Postoperative FEV1 and forced vital capacity (FVC) were accurately predicted by the formula: postoperative FEV1 (or FVC) . preoperative FEV1 X percent function of regions of lung not to be resected (r . 0.88 and 0.95, respectively). Ventilation and perfusion scans are equally effective in prediction. Washout data add to the sophistication of the method by permitting the qualitative evaluation of ventilation during tidal breathing. Criteria for patients requiring the study are suggested.

  9. Pioglitazone after Ischemic Stroke or Transient Ischemic Attack

    PubMed Central

    Kernan, W.N.; Viscoli, C.M.; Furie, K.L.; Young, L.H.; Inzucchi, S.E.; Gorman, M.; Guarino, P.D.; Lovejoy, A.M.; Peduzzi, P.N.; Conwit, R.; Brass, L.M.; Schwartz, G.G.; Adams, H.P.; Berger, L.; Carolei, A.; Clark, W.; Coull, B.; Ford, G.A.; Kleindorfer, D.; O’Leary, J.R.; Parsons, M.W.; Ringleb, P.; Sen, S.; Spence, J.D.; Tanne, D.; Wang, D.; Winder, T.R.

    2016-01-01

    BACKGROUND Patients with ischemic stroke or transient ischemic attack (TIA) are at increased risk for future cardiovascular events despite current preventive therapies. The identification of insulin resistance as a risk factor for stroke and myocardial infarction raised the possibility that pioglitazone, which improves insulin sensitivity, might benefit patients with cerebrovascular disease. METHODS In this multicenter, double-blind trial, we randomly assigned 3876 patients who had had a recent ischemic stroke or TIA to receive either pioglitazone (target dose, 45 mg daily) or placebo. Eligible patients did not have diabetes but were found to have insulin resistance on the basis of a score of more than 3.0 on the homeostasis model assessment of insulin resistance (HOMA-IR) index. The primary outcome was fatal or nonfatal stroke or myocardial infarction. RESULTS By 4.8 years, a primary outcome had occurred in 175 of 1939 patients (9.0%) in the pioglitazone group and in 228 of 1937 (11.8%) in the placebo group (hazard ratio in the pioglitazone group, 0.76; 95% confidence interval [CI], 0.62 to 0.93; P = 0.007). Diabetes developed in 73 patients (3.8%) and 149 patients (7.7%), respectively (hazard ratio, 0.48; 95% CI, 0.33 to 0.69; P<0.001). There was no significant between-group difference in all-cause mortality (hazard ratio, 0.93; 95% CI, 0.73 to 1.17; P = 0.52). Pioglitazone was associated with a greater frequency of weight gain exceeding 4.5 kg than was placebo (52.2% vs. 33.7%, P<0.001), edema (35.6% vs. 24.9%, P<0.001), and bone fracture requiring surgery or hospitalization (5.1% vs. 3.2%, P = 0.003). CONCLUSIONS In this trial involving patients without diabetes who had insulin resistance along with a recent history of ischemic stroke or TIA, the risk of stroke or myocardial infarction was lower among patients who received pioglitazone than among those who received placebo. Pioglitazone was also associated with a lower risk of diabetes but with higher risks of

  10. Sanguineous normothermic machine perfusion improves hemodynamics and biliary epithelial regeneration in DCD porcine livers

    PubMed Central

    Liu, Qiang; Nassar, Ahmed; Farias, Kevin; Buccini, Laura; Baldwin, William; Mangino, Martin; Bennett, Ana; O'Rourke, Colin; Okamoto, Toshiro; Uso, Teresa Diago; Fung, John; Abu-Elmagd, Kareem; Miller, Charles; Quintini, Cristiano

    2014-01-01

    The effect of normothermic machine perfusion (NMP) on post-reperfusion hemodynamics and extrahepatic biliary duct histology of donors after cardiac death (DCD) livers after transplantation has not been addressed thoroughly and represented the object of this study. Ten livers (n=5/group) with 60’ of warm ischemia were preserved by cold storage (CS) or sanguineous NMP for 10 hours, and then reperfused for 24 hours with whole blood in an isolated perfusion system to simulate transplantation. In our experiment, arterial and portal venous flows were stable in NMP group during the entire simulated reperfusion, while decreased dramatically in CS group after 16 hours post-reperfusion (P<.05), findings consistent with severe parenchymal injury. Similarly, significant differences existed between CS and NMP group on hepatocellular enzyme release, bile volume produced, and enzyme released into bile (P<.05). On histology CS livers presented with diffuse hepatocyte congestion, necrosis, intraparenchymal hemorrhage, denudated biliary epithelium and submucosal bile duct necrosis, while NMP liver showed very mild injury in liver parenchyma and biliary architecture. Most importantly, Ki67 staining in extrahepatic bile duct showed biliary epithelial regeneration. Our findings advance the knowledge of post-reperfusion events that characterize DCD livers and propose NMP as a beneficial preservation modality able to improve biliary regeneration after a major ischemic event, which may prevent in clinical transplantation the development of ischemic cholangiopathy. PMID:24805852

  11. Radionuclide injury to the lung.

    PubMed Central

    Dagle, G E; Sanders, C L

    1984-01-01

    Radionuclide injury to the lung has been studied in rats, hamsters, dogs, mice and baboons. Exposure of the lung to high dose levels of radionuclides produces a spectrum of progressively more severe functional and morphological changes, ranging from radiation pneumonitis and fibrosis to lung tumors. These changes are somewhat similar for different species. Their severity can be related to the absorbed radiation dose (measured in rads) produced by alpha, beta or gamma radiation emanating from various deposited radionuclides. The chemicophysical forms of radionuclides and spatial-temporal factors are also important variables. As with other forms of injury to the lung, repair attempts are highlighted by fibrosis and proliferation of pulmonary epithelium. Lung tumors are the principal late effect observed in experimental animals following pulmonary deposition of radionuclides at dose levels that do not result in early deaths from radiation pneumonitis or fibrosis. The predominant lung tumors described have been of epithelial origin and have been classified, in decreasing frequency of occurrence, as adenocarcinoma, bronchioloalveolar carcinoma, epidermoid carcinomas and combined epidermoid and adenocarcinoma. Mesothelioma and fibrosarcoma have been observed in rats, but less commonly in other species. Hemangiosarcomas were frequency observed in dogs exposed to beta-gamma emitters, and occasionally in rats exposed to alpha emitters. These morphologic changes in the lungs of experimental animals were reviewed and issues relevant to the prediction of human hazards discussed. PMID:6376095

  12. Radionuclide Retention in Concrete Wasteforms

    SciTech Connect

    Wellman, Dawn M.; Jansik, Danielle P.; Golovich, Elizabeth C.; Cordova, Elsa A.

    2012-09-24

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of LLW and MLLW, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

  13. Determination of skeletal muscle perfusion using arterial spin labeling NMRI: validation by comparison with venous occlusion plethysmography.

    PubMed

    Raynaud, J S; Duteil, S; Vaughan, J T; Hennel, F; Wary, C; Leroy-Willig, A; Carlier, P G

    2001-08-01

    T(1)-based determination of perfusion was performed with the high temporal and spatial resolution that monitoring of exercise physiology requires. As no data were available on the validation of this approach in human muscles, T(1)-based NMRI of perfusion was compared to standard strain-gauge venous occlusion plethysmography performed simultaneously within a 4 T magnet. Two different situations were investigated in 21 healthy young volunteers: 1) a 5-min ischemia of the leg, or 2) a 2-3 min ischemic exercise consisting of a plantar flexion on an amagnetic ergometer. Leg perfusion was monitored over 5-15 min of the recovery phase, after the air-cuff arterial occlusion had been released. The interesting features of the sequence were the use of a saturation-recovery module for the introduction of a T(1) modulation and of single-shot spin echo for imaging. Spatial resolution was 1.7 x 2.0 mm and temporal resolution was 2 s. For data analysis, ROIs were traced on different muscles and perfusion was calculated from the differences in muscle signal intensity in successive images. To allow comparison with the global measurement of perfusion by plethysmography, the T(1)-based NMR measurements in exercising muscles were rescaled to the leg cross-section. The perfusion measurements obtained by plethysmography and NMRI were in close agreement with a correlation coefficient between 0.87 and 0.92. This indicates that pulsed arterial techniques provide determination of muscle perfusion not only with superior spatial and temporal resolution but also with exactitude.

  14. A New Ischemic Model Using a Radiofrequency Wire Electrode in a Rabbit Hindlimb

    SciTech Connect

    Baik, Hye Won Kwak, Byung Kook; Shim, Hyung Jin; Kim, Yang Soo; Lee, Jong Beom; Kim, Kun Sang

    2008-07-15

    The purpose of this study was to establish an ischemic rabbit hindlimb model using a radiofrequency (RF) wire electrode. We inserted a polytetrafluoroethylene-coated wire with a 2-cm exposed tip into the left superficial femoral artery of seven New Zealand white rabbits and performed RF ablation (RFA) while pulling the wire back. We assessed the clinical findings, angiography, computed tomography perfusion, and permeability surface until 6 weeks after RFA. The angiography demonstrated complete obstruction from the proximal external iliac artery to the distal superficial femoral artery and showed a gradual increment in the angiogenic score, which represents the degree of angiogenesis (r = 0.86, p < 0.0001). The left-to-right ratios of the computed tomography perfusion and permeability surface were significantly reduced after 4 days (p < 0.05), and then they gradually increased with time. We conclude that endovascular RFA using an RF wire electrode is a reproducible and measurable way to create an ischemic rabbit hindlimb model.

  15. Characterization of stroke lesions using a histogram-based data analysis including diffusion- and perfusion-weighted imaging

    NASA Astrophysics Data System (ADS)

    Grzesik, Alexander; Bernarding, Johannes; Braun, Juergen; Koennecke, Hans-Christian; Wolf, Karl J.; Tolxdorff, Thomas

    2000-04-01

    Diffusion- and perfusion-weighted magnetic resonance imaging (DWI, PWI) allows the diagnosis of ischemic brain injury at a time when ischemic lesions may not yet be detectable in computer tomography or T2-weighted (T2w) MRI. However, regions with pathologic apparent diffusion coefficients (ADC) do not necessarily match with regions of prolonged mean transit times (MTT) or pathologic relative cerebral blood flow (rCBF). Mismatching parts are thought to correlate with tissues that can be saved by appropriate treatment. Ten patients with cerebral ischemia underwent standard T1w and T2w imaging as well as single-shot echo planar imaging (EPI) DWI, and PWI. Multidimensional histograms were constructed from T2w images, DWI, ADC, rCBF, and MTT maps. After segmenting different tissues, signal changes of ischemic tissues relative to unaffected parenchyma were calculated. Combining different information allowed the segmentation of lesions and unaffected tissues. Acute infarcts exhibited decreased ADC values as well as hypo- and hyperperfused areas. Correlating ADC, T2w, and rCBF with clinical symptoms allowed the estimation of age and perfusion state of the lesions. Combining DWI, PWI, and standard imaging overcomes strongly fluctuating parameters such as ADC values. A multidimensional parameter-set characterizes unaffected and pathologic tissues which may help in the evaluation of new therapeutic strategies.

  16. The effect of Ligustrum delavayanum on isolated perfused rat heart

    PubMed Central

    Stankovičová, Tatiana; Frýdl, Miroslav; Kubicová, Mária; Baróniková, Slávka; Nagy, Milan; Grančai, Daniel; Švec, Pavel

    2001-01-01

    BACKGROUND: Extract of ligustrum leaves (Ligustrum delavayanum Hariot [Oleaceae]) is well known in traditional Chinese medicine. One of the active components, oleuropein, displays vasodilating and hypotensive effects. OBJECTIVE: To analyze the effect of 0.008% lyophilized extract of ligustrum dissolved in 0.5% ethanol on heart function. ANIMALS AND METHODS: Experiments were done on isolated rat hearts perfused by the Langendorff method in control conditions and during ischemic-reperfusion injury. RESULTS: Application of ligustrum induced positive inotropic and vasodilating effects in spontaneously beating hearts. Pretreatment of the hearts with ligustrum reduced left ventricular diastolic pressure measured during reperfusion and improved left ventricular contraction compared with hearts without any pretreatment. Ligustrum significantly suppressed the incidence and duration of cardiac reperfusion arrhythmias, expressed as G-score, from 7.40±0.58 in nontreated rats to 1.97±0.50. DISCUSSION: Application of ligustrum or ethanol alone induced changes in coordination between atria and ventricles during ischemia-reperfusion injury. The ‘g-score’, a new parameter summing the incidence and duration of atrioventricular blocks, atrioventricular dissociation and cardiac arrest, is introduced. The g-scores with ligustrum pretreatment were higher during ischemia than during reperfusion. Ethanol significantly depressed myocardial contractility and coronary flow, and nonsignificantly decreased heart rate of isolated rat hearts. Electrical changes observed during coronary reperfusion in the presence of ethanol were accompanied by deterioration of contractile function. CONCLUSIONS: Ligustrum had a significant protective effect on rat myocardium against ischemic-reperfusion injury. Ethanol partially attenuated the protective effect of ligustrum. PMID:20428448

  17. Human islet isolation--a prospective randomized comparison of pancreatic vascular perfusion with hyperosmolar citrate or University of Wisconsin solution.

    PubMed

    Robertson, G S; Chadwick, D; Thirdborough, S; Swift, S; Davies, J; James, R; Bell, P R; London, N J

    1993-09-01

    University of Wisconsin solution has become the most commonly used vascular perfusate during multiorgan donation world-wide. In the UK however, hyperosmolar citrate remains in common use. The purpose of this prospective randomized study was to compare the effect of systemic perfusion with UW or HOC on subsequent islet yield and purification for pancreata with short cold ischemic times. Seven pancreata were randomized to each group, with the donor age, pancreas weight, and period of cold ischemia being similar in both. Perfusion with UW was shown to inhibit collagenase digestion, and a higher concentration of this enzyme was needed to achieve comparable numbers of islets with good separation of exocrine and islet tissue after a similar period of digestion. There were no differences in the number, size, purity, or viability of islets between the two groups. In conclusion, UW solution offers no benefits over HOC for pancreata with short cold ischemic times, and because of its expense and need to use greater amounts of collagenase enzyme, we continue to use HOC.

  18. Human islet isolation--a prospective randomized comparison of pancreatic vascular perfusion with hyperosmolar citrate or University of Wisconsin solution.

    PubMed

    Robertson, G S; Chadwick, D; Thirdborough, S; Swift, S; Davies, J; James, R; Bell, P R; London, N J

    1993-09-01

    University of Wisconsin solution has become the most commonly used vascular perfusate during multiorgan donation world-wide. In the UK however, hyperosmolar citrate remains in common use. The purpose of this prospective randomized study was to compare the effect of systemic perfusion with UW or HOC on subsequent islet yield and purification for pancreata with short cold ischemic times. Seven pancreata were randomized to each group, with the donor age, pancreas weight, and period of cold ischemia being similar in both. Perfusion with UW was shown to inhibit collagenase digestion, and a higher concentration of this enzyme was needed to achieve comparable numbers of islets with good separation of exocrine and islet tissue after a similar period of digestion. There were no differences in the number, size, purity, or viability of islets between the two groups. In conclusion, UW solution offers no benefits over HOC for pancreata with short cold ischemic times, and because of its expense and need to use greater amounts of collagenase enzyme, we continue to use HOC. PMID:8212148

  19. Intestinal perfusion monitoring using photoplethysmography

    PubMed Central

    Wilson, Mark A.; Ericson, M. Nance; Coté, Gerard L.

    2013-01-01

    Abstract. In abdominal trauma patients, monitoring intestinal perfusion and oxygen consumption is essential during the resuscitation period. Photoplethysmography is an optical technique potentially capable of monitoring these changes in real time to provide the medical staff with a timely and quantitative measure of the adequacy of resuscitation. The challenges for using optical techniques in monitoring hemodynamics in intestinal tissue are discussed, and the solutions to these challenges are presented using a combination of Monte Carlo modeling and theoretical analysis of light propagation in tissue. In particular, it is shown that by using visible wavelengths (i.e., 470 and 525 nm), the perfusion signal is enhanced and the background contribution is decreased compared with using traditional near-infrared wavelengths leading to an order of magnitude enhancement in the signal-to-background ratio. It was further shown that, using the visible wavelengths, similar sensitivity to oxygenation changes could be obtained (over 50% compared with that of near-infrared wavelengths). This is mainly due to the increased contrast between tissue and blood in that spectral region and the confinement of the photons to the thickness of the small intestine. Moreover, the modeling results show that the source to detector separation should be limited to roughly 6 mm while using traditional near-infrared light, with a few centimeters source to detector separation leads to poor signal-to-background ratio. Finally, a visible wavelength system is tested in an in vivo porcine study, and the possibility of monitoring intestinal perfusion changes is showed. PMID:23942635

  20. A Generator-Produced Gallium-68 Radiopharmaceutical for PET Imaging of Myocardial Perfusion

    PubMed Central

    Sharma, Vijay; Sivapackiam, Jothilingam; Harpstrite, Scott E.; Prior, Julie L.; Gu, Hannah; Rath, Nigam P.; Piwnica-Worms, David

    2014-01-01

    Lipophilic cationic technetium-99m-complexes are widely used for myocardial perfusion imaging (MPI). However, inherent uncertainties in the supply chain of molybdenum-99, the parent isotope required for manufacturing 99Mo/99mTc generators, intensifies the need for discovery of novel MPI agents incorporating alternative radionuclides. Recently, germanium/gallium (Ge/Ga) generators capable of producing high quality 68Ga, an isotope with excellent emission characteristics for clinical PET imaging, have emerged. Herein, we report a novel 68Ga-complex identified through mechanism-based cell screening that holds promise as a generator-produced radiopharmaceutical for PET MPI. PMID:25353349

  1. Quantitative myocardial perfusion imaging in a porcine ischemia model using a prototype spectral detector CT system

    NASA Astrophysics Data System (ADS)

    Fahmi, Rachid; Eck, Brendan L.; Levi, Jacob; Fares, Anas; Dhanantwari, Amar; Vembar, Mani; Bezerra, Hiram G.; Wilson, David L.

    2016-03-01

    We optimized and evaluated dynamic myocardial CT perfusion (CTP) imaging on a prototype spectral detector CT (SDCT) scanner. Simultaneous acquisition of energy sensitive projections on the SDCT system enabled projection-based material decomposition, which typically performs better than image-based decomposition required by some other system designs. In addition to virtual monoenergetic, or keV images, the SDCT provided conventional (kVp) images, allowing us to compare and contrast results. Physical phantom measurements demonstrated linearity of keV images, a requirement for quantitative perfusion. Comparisons of kVp to keV images demonstrated very significant reductions in tell-tale beam hardening (BH) artifacts in both phantom and pig images. In phantom images, consideration of iodine contrast to noise ratio and small residual BH artifacts suggested optimum processing at 70 keV. The processing pipeline for dynamic CTP measurements included 4D image registration, spatio-temporal noise filtering, and model-independent singular value decomposition deconvolution, automatically regularized using the L-curve criterion. In normal pig CTP, 70 keV perfusion estimates were homogeneous throughout the myocardium. At 120 kVp, flow was reduced by more than 20% on the BH-hypo-enhanced myocardium, a range that might falsely indicate actionable ischemia, considering the 0.8 threshold for actionable FFR. With partial occlusion of the left anterior descending (LAD) artery (FFR  <  0.8), perfusion defects at 70 keV were correctly identified in the LAD territory. At 120 kVp, BH affected the size and flow in the ischemic area; e.g. with FFR ≈ 0.65, the anterior-to-lateral flow ratio was 0.29  ±  0.01, over-estimating stenosis severity as compared to 0.42  ±  0.01 (p  <  0.05) at 70 keV. On the non-ischemic inferior wall (not a LAD territory), the flow ratio was 0.50  ±  0.04 falsely indicating an actionable ischemic condition in a healthy

  2. Quantitative myocardial perfusion imaging in a porcine ischemia model using a prototype spectral detector CT system.

    PubMed

    Fahmi, Rachid; Eck, Brendan L; Levi, Jacob; Fares, Anas; Dhanantwari, Amar; Vembar, Mani; Bezerra, Hiram G; Wilson, David L

    2016-03-21

    We optimized and evaluated dynamic myocardial CT perfusion (CTP) imaging on a prototype spectral detector CT (SDCT) scanner. Simultaneous acquisition of energy sensitive projections on the SDCT system enabled projection-based material decomposition, which typically performs better than image-based decomposition required by some other system designs. In addition to virtual monoenergetic, or keV images, the SDCT provided conventional (kVp) images, allowing us to compare and contrast results. Physical phantom measurements demonstrated linearity of keV images, a requirement for quantitative perfusion. Comparisons of kVp to keV images demonstrated very significant reductions in tell-tale beam hardening (BH) artifacts in both phantom and pig images. In phantom images, consideration of iodine contrast to noise ratio and small residual BH artifacts suggested optimum processing at 70 keV. The processing pipeline for dynamic CTP measurements included 4D image registration, spatio-temporal noise filtering, and model-independent singular value decomposition deconvolution, automatically regularized using the L-curve criterion. In normal pig CTP, 70 keV perfusion estimates were homogeneous throughout the myocardium. At 120 kVp, flow was reduced by more than 20% on the BH-hypo-enhanced myocardium, a range that might falsely indicate actionable ischemia, considering the 0.8 threshold for actionable FFR. With partial occlusion of the left anterior descending (LAD) artery (FFR < 0.8), perfusion defects at 70 keV were correctly identified in the LAD territory. At 120 kVp, BH affected the size and flow in the ischemic area; e.g. with FFR ≈ 0.65, the anterior-to-lateral flow ratio was 0.29 ± 0.01, over-estimating stenosis severity as compared to 0.42 ± 0.01 (p < 0.05) at 70 keV. On the non-ischemic inferior wall (not a LAD territory), the flow ratio was 0.50 ± 0.04 falsely indicating an actionable ischemic condition in a healthy territory. This ratio was 1.00 ± 0.08 at 70 ke

  3. Radionuclides in Chesapeake Bay sediments

    NASA Technical Reports Server (NTRS)

    Cressy, P. J., Jr.

    1976-01-01

    Natural and manmade gamma-ray emitting radionuclides were measured in Chesapeake Bay sediments taken near the Calvert Cliffs Nuclear Power Plant site. Samples represented several water depths, at six locations, for five dates encompassing a complete seasonal cycle. Radionuclide contents of dry sediments ranged as follows: Tl-208, 40 to 400 pCi/kg; Bi-214, 200 to 800 pCi/kg; K, 0.04 to 2.1 percent; Cs-137 5 to 1900 pCi/kg; Ru106, 40 to 1000 pCikg Co60, 1 to 27 pCi/kg. In general, radionuclide contents were positively correlated with each other and negatively correlated with sediment grain size.

  4. Using Flat-Panel Perfusion Imaging to Measure Cerebral Hemodynamics

    PubMed Central

    Lin, Chung-Jung; Guo, Wan-Yuo; Chang, Feng-Chi; Hung, Sheng-Che; Chen, Ko-Kung; Yu, Deuerling-Zheng; Wu, Chun-Hsien Frank; Liou, Jy-Kang Adrian

    2016-01-01

    Abstract Flat-detector CT perfusion (FD-CTP) imaging has demonstrated efficacy in qualitatively accessing the penumbra in acute stroke equivalent to that of magnetic resonance perfusion (MRP). The aim of our study was to evaluate the feasibility of quantifying oligemia in the brain in patients with carotid stenosis. Ten patients with unilateral carotid stenosis of >70% were included. All MRPs and FD-CTPs were performed before stenting. Region-of-interests (ROIs) including middle cerebral artery territory at basal ganglia level on both stenotic and contralateral sides were used for quantitative analysis. Relative time to peak (rTTP) was defined as TTP of the stenotic side divided by TTP of the contralateral side, and so as relative cerebral blood volume (rCBV), relative mean transit time (rMTT), and relative cerebral blood flow (rCBF). Absolute and relative TTP, CBV, MTT, CBF between two modalities were compared. For absolute quantitative analysis, the correlation of TTP was highest (r = 0.56), followed by CBV (r = 0.47), MTT (r = 0.47), and CBF (r = 0.43); for relative quantitative analysis, rCBF was the highest (r = 0.79), followed by rTTP (r = 0.75) and rCBV (r = 0.50). We confirmed that relative quantitative assessment of FD-CTP is feasible in chronic ischemic disease. Absolute quantitative measurements between MRP and FD-CTP only expressed moderate correlations. Optimization of acquisitions and algorithms is warranted to achieve better quantification. PMID:27196456

  5. Remote Ischemic Conditioning: Its Benefits and Limitations.

    PubMed

    Kloner, Robert A

    2016-03-01

    This editorial describes benefits and limitations of remote ischemic conditioning. Remote ischemic conditioning was shown to reduce myocardial intact size in at least 4 sizeable clinical trials of acute myocardial infarction. It was not effective in recent studies of cardiac surgery. Reasons for these differences are discussed.

  6. Cerebral ischemic stroke: is gender important?

    PubMed Central

    Gibson, Claire L

    2013-01-01

    Cerebral stroke continues to be a major cause of death and the leading cause of long-term disability in developed countries. Evidence reviewed here suggests that gender influences various aspects of the clinical spectrum of ischemic stroke, in terms of influencing how a patients present with ischemic stroke through to how they respond to treatment. In addition, this review focuses on discussing the various pathologic mechanisms of ischemic stroke that may differ according to gender and compares how intrinsic and hormonal mechanisms may account for such gender differences. All clinical trials to date investigating putative neuroprotective treatments for ischemic stroke have failed, and it may be that our understanding of the injury cascade initiated after ischemic injury is incomplete. Revealing aspects of the pathophysiological consequences of ischemic stroke that are gender specific may enable gender relevant and effective neuroprotective strategies to be identified. Thus, it is possible to conclude that gender does, in fact, have an important role in ischemic stroke and must be factored into experimental and clinical investigations of ischemic stroke. PMID:23756694

  7. Current trends in the management of acute ischemic stroke.

    PubMed

    Paramasivam, Srinivasan

    2015-01-01

    Stroke is the leading cause of disability and most of the cases are those of ischemic stroke. Management strategies especially for large vessel occlusive stroke have undergone a significant change in the recent years that include widespread use of thrombolytic medications followed by endovascular clot removal. For successful treatment by endovascular thrombectomy, the important factors are patient selection based on clinical criterion including age, time of onset, premorbid clinical condition, co-morbidities, National Institute of Health Stroke Scale, and imaging criterion including computed tomography (CT) head, CT angiogram and CT perfusion. Patients presenting within 4.5 hours of onset are considered for intravenous (IV) recombinant tissue plasminogen activator treatment. Mechanical clot retrieval devices have evolved over the past decade. The Mechanical Embolus Removal in Cerebral Ischemia device was approved first followed by the penumbra revascularization system. They have proven in various studies to improve recanalization with acceptable rates of symptomatic intra-cerebral hemorrhage. Introduction of stent retrievers has led to a new era in the interventional management of acute ischemic stroke (AIS). Recent trials namely MRCLEAN, ESCAPE, SWIFT PRIMEs, and EXTEND-IA have used the stent retriever predominantly and have shown unequivocal benefit in the outcome at 90 days for AIS patients with large vessel occlusion. More recently, a new catheter namely 5 MAX ACE was introduced along with improvement in the suction device. This has led to a direct aspiration first pass technique resulting in faster recanalization. Advancements in the endovascular management of AIS with large vessel occlusion have resulted in a paradigm shift in the way this disease is managed. Improvements in patient selection using clinical and imaging criterion along with technical and technological advancements in mechanical thrombectomy have made possible a significantly improved outcome

  8. Current trends in the management of acute ischemic stroke.

    PubMed

    Paramasivam, Srinivasan

    2015-01-01

    Stroke is the leading cause of disability and most of the cases are those of ischemic stroke. Management strategies especially for large vessel occlusive stroke have undergone a significant change in the recent years that include widespread use of thrombolytic medications followed by endovascular clot removal. For successful treatment by endovascular thrombectomy, the important factors are patient selection based on clinical criterion including age, time of onset, premorbid clinical condition, co-morbidities, National Institute of Health Stroke Scale, and imaging criterion including computed tomography (CT) head, CT angiogram and CT perfusion. Patients presenting within 4.5 hours of onset are considered for intravenous (IV) recombinant tissue plasminogen activator treatment. Mechanical clot retrieval devices have evolved over the past decade. The Mechanical Embolus Removal in Cerebral Ischemia device was approved first followed by the penumbra revascularization system. They have proven in various studies to improve recanalization with acceptable rates of symptomatic intra-cerebral hemorrhage. Introduction of stent retrievers has led to a new era in the interventional management of acute ischemic stroke (AIS). Recent trials namely MRCLEAN, ESCAPE, SWIFT PRIMEs, and EXTEND-IA have used the stent retriever predominantly and have shown unequivocal benefit in the outcome at 90 days for AIS patients with large vessel occlusion. More recently, a new catheter namely 5 MAX ACE was introduced along with improvement in the suction device. This has led to a direct aspiration first pass technique resulting in faster recanalization. Advancements in the endovascular management of AIS with large vessel occlusion have resulted in a paradigm shift in the way this disease is managed. Improvements in patient selection using clinical and imaging criterion along with technical and technological advancements in mechanical thrombectomy have made possible a significantly improved outcome

  9. A Multimodality Imaging Approach for Serial Assessment of Regional Changes in Lower Extremity Arteriogenesis and Tissue Perfusion in a Porcine Model of Peripheral Arterial Disease

    PubMed Central

    Stacy, Mitchel R.; Yu, Da Yu; Maxfield, Mark W.; Jaba, Irina M.; Jozwik, Bartosz P.; Zhuang, Zhen W.; Lin, Ben A.; Hawley, Christi L.; Caracciolo, Christopher M.; Pal, Prasanta; Tirziu, Daniela; Sampath, Smita; Sinusas, Albert J.

    2014-01-01

    Background A standard quantitative imaging approach to evaluate peripheral arterial disease (PAD) does not exist. Quantitative tools for evaluating arteriogenesis in vivo are not readily available and the feasibility of monitoring serial regional changes in lower extremity perfusion has not been examined. Methods and Results Serial changes in lower extremity arteriogenesis and muscle perfusion were evaluated following femoral artery occlusion in a porcine model using SPECT/CT imaging with post-mortem validation of in vivo findings using gamma counting, post-mortem imaging, and histological analysis. Hybrid thallium-201 (201Tl) SPECT/CT imaging was performed in pigs (n=8) at baseline, immediately post-occlusion, and at 1 and 4 weeks post-occlusion. CT imaging was used to identify muscle regions of interest in the ischemic (I) and non-ischemic (NI) hindlimbs for quantification of regional changes in CT defined arteriogenesis and quantification of 201Tl perfusion. Four weeks post-occlusion, post-mortem tissue 201Tl activity was measured by gamma counting and immunohistochemistry was performed to assess capillary density. Relative 201Tl retention (I/NI) was reduced immediately post-occlusion in distal and proximal muscles and remained lower in calf and gluteus muscles 4 weeks later. Analysis of CT angiography revealed collateralization at 4 weeks within proximal muscles (p<0.05). SPECT perfusion correlated with tissue gamma counting at 4 weeks (p=0.01). Increased capillary density was seen within the ischemic calf at 4 weeks (p=0.004). Conclusions 201Tl SPECT/CT imaging permits serial, regional quantification of arteriogenesis and resting tissue perfusion following limb ischemia. This approach may be effective for detection of disease and monitoring therapy in PAD. PMID:24170237

  10. Extinct radionuclides. [in solar system

    NASA Technical Reports Server (NTRS)

    Podosek, F. A.; Swindle, T. D.

    1988-01-01

    Extinct radionuclides, or radioactive isotopes with lifetimes of the order of 1 to 100 Myr that are now extinct in the solar system are discussed. Evidence is presented for the presence of such radionuclides in the early solar system, including Al-26, Mn-53, Pd-107, I-129, Pu-244, and Sm-146. It is suggested that the abundances of these species provide constraints on nucleosynthetic time scales and the history of solar system materials before they became the solar system. The shortest-lived species is Al-26, which may have been sufficiently abundant to be the major heat source for meteorite parent-body metamorphism or igneous differentiation.

  11. Real-time ultrasound perfusion imaging in acute stroke: assessment of cerebral perfusion deficits related to arterial recanalization.

    PubMed

    Bolognese, Manuel; Artemis, Dimitrios; Alonso, Angelika; Hennerici, Michael G; Meairs, Stephan; Kern, Rolf

    2013-05-01

    We investigated whether real-time ultrasound perfusion imaging (rt-UPI) is able to detect perfusion changes related to arterial recanalization in the acute phase of middle cerebral artery (MCA) stroke. Twenty-four patients with acute territorial MCA stroke were examined with rt-UPI and transcranial color-coded duplex ultrasound (TCCD). Ultrasound studies were consecutively performed within 24 h and 72-96 h after stroke onset. Real-time UPI parameters of bolus kinetics (time to peak, rt-TTP) and of refill kinetics (plateau A and slope β of the exponential replenishment curve) were calculated from regions of interest of ischemic versus normal brain tissue; these parameters were compared between early and follow-up examinations in patients who recanalized. At the early examination, there was a delay of rt-TTP in patients with MCA occlusion (rt-TTP [s]: 13.09 ± 3.21 vs. 10.16 ± 2.6; p = 0.01) and a lower value of the refill parameter β (β [1/s]: 0.62 ± 0.34 vs. 1.09 ± 0.58; p = 0.01) in ischemic compared with normal brain tissue, whereas there were no differences of the parameters A and Axβ. At follow-up, the delay of rt-TTP was reversible once recanalization of an underlying MCA obstruction was demonstrated: rt-TTP [s], 13.09 ± 3.21 at 24 h versus 10.95 ± 1.5 at 72-96 h (p = 0.03). Correspondingly, β showed a higher slope than at the first examination: β [1/s]: 0.55 ± 0.29 at 24 h versus 0.71 ± 0.27 at 72-96 h (p = 0.04). We conclude that real-time UPI can detect hemodynamic impairment in acute MCA occlusion and subsequent improvement following arterial recanalization. This offers the chance for bedside monitoring of the hemodynamic compromise (e.g. during therapeutic interventions such as systemic thrombolysis).

  12. Carbonic Anhydrase Protects Fatty Liver Grafts against Ischemic Reperfusion Damage

    PubMed Central

    Bejaoui, Mohamed; Pantazi, Eirini; De Luca, Viviana; Panisello, Arnau; Folch-Puy, Emma; Hotter, Georgina; Capasso, Clemente; T. Supuran, Claudiu; Rosselló-Catafau, Joan

    2015-01-01

    Carbonic anhydrases (CAs) are ubiquitous metalloenzymes that catalyze the reversible hydration of carbon dioxide to bicarbonate and a proton. CAs are involved in numerous physiological and pathological processes, including acid-base homeostasis, electrolyte balance, oxygen delivery to tissues and nitric oxide generation. Given that these processes are found to be dysregulated during ischemia reperfusion injury (IRI), and taking into account the high vulnerability of steatotic livers to preservation injury, we hypothesized a new role for CA as a pharmacological agent able to protect against ischemic damage. Two different aspects of the role of CA II in fatty liver grafts preservation were evaluated: 1) the effect of its addition to Institut Georges Lopez (IGL-1) storage solution after cold ischemia; 2) and after 24h of cold storage followed by two hours of normothermic ex-vivo perfusion. In all cases, liver injury, CA II protein concentration, CA II mRNA levels and CA II activity were determined. In case of the ex-vivo perfusion, we further assessed liver function (bile production, bromosulfophthalein clearance) and Western blot analysis of phosphorylated adenosine monophosphate activated protein kinase (AMPK), mitogen activated protein kinases family (MAPKs) and endoplasmic reticulum stress (ERS) parameters (GRP78, PERK, IRE, eIF2α and ATF6). We found that CA II was downregulated after cold ischemia. The addition of bovine CA II to IGL-1 preservation solution efficiently protected steatotic liver against cold IRI. In the case of reperfusion, CA II protection was associated with better function, AMPK activation and the prevention of ERS and MAPKs activation. Interestingly, CA II supplementation was not associated with enhanced CO2 hydration. The results suggest that CA II modulation may be a promising target for fatty liver graft preservation. PMID:26225852

  13. Human Urinary Kallidinogenase Promotes Angiogenesis and Cerebral Perfusion in Experimental Stroke

    PubMed Central

    Chen, Yanting; Zhang, Meijuan; Qian, Lai; Chen, Yan; Wu, Zhengzheng; Xu, Yun; Li, Jingwei

    2015-01-01

    Angiogenesisis a key restorative mechanism in response to ischemia, and pro-angiogenic therapy could be beneficial in stroke. Accumulating experimental and clinical evidence suggest that human urinary kallidinogenase (HUK) improves stroke outcome, but the underlying mechanisms are not clear. The aim of current study was to verify roles of HUK in post-ischemic angiogenesis and identify relevant mediators. In rat middle cerebral artery occlusion (MCAO) model, we confirmed that HUK treatment could improve stroke outcome, indicated by reduced infarct size and improved neurological function. Notably, the 18F-FDG micro-PET scan indicated that HUK enhanced cerebral perfusion in rats after MCAO treatment. In addition, HUK promotespost-ischemic angiogenesis, with increased vessel density as well as up-regulated VEGF andapelin/APJ expression in HUK-treated MCAO mice. In endothelial cell cultures, induction of VEGF and apelin/APJ expression, and ERK1/2 phosphorylation by HUK was further confirmed. These changes were abrogated by U0126, a selective ERK1/2 inhibitor. Moreover, F13A, a competitive antagonist of APJ receptor, significantly suppressed HUK-induced VEGF expression. Furthermore, angiogenic functions of HUK were inhibited in the presence of selective bradykinin B1 or B2 receptor antagonist both in vitro and in vivo. Our findings indicate that HUK treatment promotes post-ischemic angiogenesis and cerebral perfusion via activation of bradykinin B1 and B2 receptors, which is potentially due to enhancement expression of VEGF and apelin/APJ in ERK1/2 dependent way. PMID:26222055

  14. Changes in rest and exercise myocardial perfusion and left ventricular function 3 to 26 weeks after clinically uncomplicated acute myocardial infarction: effects of exercise training

    SciTech Connect

    Hung, J.; Gordon, E.P.; Houston, N.; Haskell, W.L.; Goris, M.L.; DeBusk, R.F.

    1984-11-01

    The effects of exercise training on exercise myocardial perfusion and left ventricular (LV) function in the first 6 months after clinically uncomplicated acute myocardial infarction (AMI) were assessed in 53 consecutive men aged 55 +/- 9 years. Symptom-limited treadmill exercise with thallium myocardial perfusion scintigraphy and symptom-limited upright bicycle ergometry with equilibrium gated radionuclide ventriculography were performed 3, 11 and 26 weeks after AMI by 23 men randomized to training and 30 randomized to no training. Peak cycle capacity increased in both groups between 3 and 26 weeks (p less than 0.01), but reached higher levels in trained than in untrained patients (803 +/- 149 vs 648 +/- 182 kg-m/min, p less than 0.01). Reversible thallium perfusion defects were significantly more frequent at 3 than at 26 weeks: 59% and 36% of patients, respectively (p less than 0.05), without significant inter-group differences. Values of LV ejection fraction at rest, submaximal and peak exercise did not change significantly in either group. The increase in functional capacity, i.e., peak treadmill or bicycle workload, that occurred 3 to 26 weeks after infarction was significantly correlated with the increase in peak exercise heart rate (p less than 0.001), but not with changes in myocardial perfusion or LV function determined by radionuclide techniques. Changes in myocardial perfusion or LV function do not appear to account for the improvement in peak functional capacity that occurs within the first 6 months after clinically uncomplicated AMI.

  15. Long term perfusion system supporting adipogenesis.

    PubMed

    Abbott, Rosalyn D; Raja, Waseem K; Wang, Rebecca Y; Stinson, Jordan A; Glettig, Dean L; Burke, Kelly A; Kaplan, David L

    2015-08-01

    Adipose tissue engineered models are needed to enhance our understanding of disease mechanisms and for soft tissue regenerative strategies. Perfusion systems generate more physiologically relevant and sustainable adipose tissue models, however adipocytes have unique properties that make culturing them in a perfusion environment challenging. In this paper we describe the methods involved in the development of two perfusion culture systems (2D and 3D) to test their applicability for long term in vitro adipogenic cultures. It was hypothesized that a silk protein biomaterial scaffold would provide a 3D framework, in combination with perfusion flow, to generate a more physiologically relevant sustainable adipose tissue engineered model than 2D cell culture. Consistent with other studies evaluating 2D and 3D culture systems for adipogenesis we found that both systems successfully model adipogenesis, however 3D culture systems were more robust, providing the mechanical structure required to contain the large, fragile adipocytes that were lost in 2D perfused culture systems. 3D perfusion also stimulated greater lipogenesis and lipolysis and resulted in decreased secretion of LDH compared to 2D perfusion. Regardless of culture configuration (2D or 3D) greater glycerol was secreted with the increased nutritional supply provided by perfusion of fresh media. These results are promising for adipose tissue engineering applications including long term cultures for studying disease mechanisms and regenerative approaches, where both acute (days to weeks) and chronic (weeks to months) cultivation are critical for useful insight. PMID:25843606

  16. Sumatriptan and cerebral perfusion in healthy volunteers.

    PubMed

    Scott, A K; Grimes, S; Ng, K; Critchley, M; Breckenridge, A M; Thomson, C; Pilgrim, A J

    1992-04-01

    1. The effect of sumatriptan on regional cerebral perfusion was studied in healthy volunteers. 2. Intravenous sumatriptan (2 mg) had no detectable effect on regional cerebral perfusion as measured using a SPECT system with 99technetiumm labelled hexemethylpropyleneamineoxime. 3. Sumatriptan had no effect on pulse, blood pressure or ECG indices. 4. All six volunteers experienced minor adverse effects during the intravenous infusion.

  17. Personality factors correlate with regional cerebral perfusion.

    PubMed

    O'Gorman, R L; Kumari, V; Williams, S C R; Zelaya, F O; Connor, S E J; Alsop, D C; Gray, J A

    2006-06-01

    There is an increasing body of evidence pointing to a neurobiological basis of personality. The purpose of this study was to investigate the biological bases of the major dimensions of Eysenck's and Cloninger's models of personality using a noninvasive magnetic resonance perfusion imaging technique in 30 young, healthy subjects. An unbiased voxel-based analysis was used to identify regions where the regional perfusion demonstrated significant correlation with any of the personality dimensions. Highly significant positive correlations emerged between extraversion and perfusion in the basal ganglia, thalamus, inferior frontal gyrus and cerebellum and between novelty seeking and perfusion in the cerebellum, cuneus and thalamus. Strong negative correlations emerged between psychoticism and perfusion in the basal ganglia and thalamus and between harm avoidance and perfusion in the cerebellar vermis, cuneus and inferior frontal gyrus. These observations suggest that personality traits are strongly associated with resting cerebral perfusion in a variety of cortical and subcortical regions and provide further evidence for the hypothesized neurobiological basis of personality. These results may also have important implications for functional neuroimaging studies, which typically rely on the modulation of cerebral hemodynamics for detection of task-induced activation since personality effects may influence the intersubject variability for both task-related activity and resting cerebral perfusion. This technique also offers a novel approach for the exploration of the neurobiological correlates of human personality.

  18. Long term perfusion system supporting adipogenesis

    PubMed Central

    Abbott, Rosalyn D.; Raja, Waseem K.; Wang, Rebecca Y.; Stinson, Jordan A.; Glettig, Dean L.; Burke, Kelly A.; Kaplan, David L.

    2015-01-01

    Adipose tissue engineered models are needed to enhance our understanding of disease mechanisms and for soft tissue regenerative strategies. Perfusion systems generate more physiologically relevant and sustainable adipose tissue models, however adipocytes have unique properties that make culturing them in a perfusion environment challenging. In this paper we describe the methods involved in the development of two perfusion culture systems (2D and 3D) to test their applicability for long term in vitro adipogenic cultures. It was hypothesized that a silk protein biomaterial scaffold would provide a 3D framework, in combination with perfusion flow, to generate a more physiologically relevant sustainable adipose tissue engineered model than 2D cell culture. Consistent with other studies evaluating 2D and 3D culture systems for adipogenesis we found that both systems successfully model adipogensis, however 3D culture systems were more robust, providing the mechanical structure required to contain the large, fragile adipocytes that were lost in 2D perfused culture systems. 3D perfusion also stimulated greater lipogenesis and lipolysis and resulted in decreased secretion of LDH compared to 2D perfusion. Regardless of culture configuration (2D or 3D) greater glycerol was secreted with the increased nutritional supply provided by perfusion of fresh media. These results are promising for adipose tissue engineering applications including long term cultures for studying disease mechanisms and regenerative approaches, where both acute (days to weeks) and chronic (weeks to months) cultivation are critical for useful insight. PMID:25843606

  19. Long term perfusion system supporting adipogenesis.

    PubMed

    Abbott, Rosalyn D; Raja, Waseem K; Wang, Rebecca Y; Stinson, Jordan A; Glettig, Dean L; Burke, Kelly A; Kaplan, David L

    2015-08-01

    Adipose tissue engineered models are needed to enhance our understanding of disease mechanisms and for soft tissue regenerative strategies. Perfusion systems generate more physiologically relevant and sustainable adipose tissue models, however adipocytes have unique properties that make culturing them in a perfusion environment challenging. In this paper we describe the methods involved in the development of two perfusion culture systems (2D and 3D) to test their applicability for long term in vitro adipogenic cultures. It was hypothesized that a silk protein biomaterial scaffold would provide a 3D framework, in combination with perfusion flow, to generate a more physiologically relevant sustainable adipose tissue engineered model than 2D cell culture. Consistent with other studies evaluating 2D and 3D culture systems for adipogenesis we found that both systems successfully model adipogenesis, however 3D culture systems were more robust, providing the mechanical structure required to contain the large, fragile adipocytes that were lost in 2D perfused culture systems. 3D perfusion also stimulated greater lipogenesis and lipolysis and resulted in decreased secretion of LDH compared to 2D perfusion. Regardless of culture configuration (2D or 3D) greater glycerol was secreted with the increased nutritional supply provided by perfusion of fresh media. These results are promising for adipose tissue engineering applications including long term cultures for studying disease mechanisms and regenerative approaches, where both acute (days to weeks) and chronic (weeks to months) cultivation are critical for useful insight.

  20. In-vivo regional myocardial perfusion measurements in a porcine model by ECG-gated multislice computed tomography

    NASA Astrophysics Data System (ADS)

    Stantz, Keith M.; Liang, Yun; Meyer, Cristopher A.; Teague, Shawn; Stecker, Michael; Hutchins, Gary; McLennan, Gordon; Persohn, Scott

    2003-05-01

    Purpose: To evaluate whether functional multi-slice computed tomography (MSCT) can identify regional areas of normally perfused and ischemic myocardium in a porcine model. Material and Methods: Three out bred pigs, two of which had ameroids surgically implanted to constrict flow within the LAD and LCx coronary arteries, were injected with 25 mL of iopromide (Isovue) at a rate of 5 mL/second via the femoral or jugular vein. Sixty axial scans along the short axis of the heart was acquired on a 16-slice CT scanner (Philips MX8000-IDT) triggered at end-diastole of the cardiac cycle and acquiring an image within 270 msec. A second series of scans were taken after an intravenous injection of a vasodilator, 150 μg/kg/min of adenosine. ROIs were drawn around the myocardial tissue and the resulting time-density curves were used to extract perfusion values. Results: Determination of the myocardial perfusion and fractional blood volume implementing three different perfusion models. A 5-point averaging or 'smoothing' algorithm was employed to effectively filter the data due to its noisy nature. The (preliminary) average perfusion and fractional blood volume values over selected axial slices for the pig without an artificially induced stenosis were measured to be 84 +/- 22 mL/min/100g-tissue and 0.17 +/- 0.04 mL/g-tissue, the former is consistent with PET scan and EBCT results. The pig with a stenosis in the left LAD coronary artery showed a reduced global perfusion value -- 45 mL/min/100g-tissue. Correlations in regional perfusion values relative to the stenosis were weak. During the infusion of adenosine, averaged perfusion values for the three subjects increased by 46 (+/-45) percent, comparable to increases measured with PET. Conclusion: Quantifying global perfusion values using MDCT appear encouraging. Future work will focus resolving the systematic effects from noise due to signal fluctuation from the porcine tachyardia (80-93 BPM) and provide a more robust measurement

  1. [Assessing myocardial perfusion with positron emission tomography].

    PubMed

    vom Dahl, J

    2001-11-01

    Positron emission tomography (PET) of the heart has gained widespread scientific and clinical acceptance with regard to two indications: 1) The detection of perfusion abnormalities by qualitative and semiquantitative analyses of perfusion images at rest and during physical or pharmacological stress using well-validated perfusion tracers, such as N-13 ammonia, Rb-82 rubidium chloride, or O-15 labeled water. 2) Viability imaging of myocardial regions with reduced contractility by combining perfusion measurements with substrate metabolism as assessed from F-18 deoxyglucose utilization. This overview summarizes the use of PET as a perfusion imaging method. With a sensitivity > 90% in combination with high specificity, PET is today the best-validated available nuclear imaging technique for the diagnosis of coronary artery disease (CAD). The short half-life of the perfusion tracers in combination with highly sophisticated hard- and software enables rapid PET studies with high patient throughput. The high diagnostic accuracy and the methological advantages as compared to conventional scintigraphy allows one to use PET perfusion imaging to detect subtle changes in the perfusion reserve for the detection of CAD in high risk but asymptomatic patients as well as in patients with proven CAD undergoing various treatment forms such as risk factor reduction or coronary revascularization. In patients following orthotopic heart transplantation, evolving transplant vasculopathy can be detected at an early stage. Quantitative PET imaging at rest allows for detection of myocardial viability since cellular survival is based on maintenance of a minimal perfusion and structural changes correlate to the degree of perfusion reduction. Furthermore, quantitative assessment of the myocardial perfusion reserve detects the magnitude and competence of collaterals in regions with occluded epicardial collaterals and, thus, imaging of several coronary distribution territories in one noninvasive

  2. Radionuclide labeled lymphocytes for therapeutic use

    DOEpatents

    Srivastava, S.C.; Fawwaz, R.A.; Richards, P.

    1983-05-03

    Lymphocytes labelled with ..beta..-emitting radionuclides are therapeutically useful, particularly for lymphoid ablation. They are prepared by incubation of the lymphocytes with the selected radionuclide-oxine complex.

  3. Conditions and processes affecting radionuclide transport

    USGS Publications Warehouse

    Simmons, Ardyth M.; Neymark, Leonid A.

    2012-01-01

    Understanding of unsaturated-zone transport is based on laboratory and field-scale experiments. Fractures provide advective transport pathways. Sorption and matrix diffusion may contribute to retardation of radionuclides. Conversely, sorption onto mobile colloids may enhance radionuclide transport.

  4. Ischemic preconditioning and clinical scenarios

    PubMed Central

    Narayanan, Srinivasan V.; Dave, Kunjan R.; Perez-Pinzon, Miguel A.

    2013-01-01

    Purpose of review Ischemic preconditioning (IPC) is gaining attention as a novel neuroprotective therapy and could provide an improved mechanistic understanding of tolerance to cerebral ischemia. The purpose of this article is to review the recent work in the field of IPC and its applications to clinical scenarios. Recent findings The cellular signaling pathways that are activated following IPC are now better understood and have enabled investigators to identify several IPC mimetics. Most of these studies were performed in rodents, and efficacy of these mimetics remains to be evaluated in human patients. Additionally, remote ischemic preconditioning (RIPC) may have higher translational value than IPC. Repeated cycles of temporary ischemia in a remote organ can activate protective pathways in the target organ, including the heart and brain. Clinical trials are underway to test the efficacy of RIPC in protecting brain against subarachnoid hemorrhage. Summary IPC, RIPC, and IPC mimetics have the potential to be therapeutic in various clinical scenarios. Further understanding of IPC-induced neuroprotection pathways and utilization of clinically relevant animal models are necessary to increase the translational potential of IPC in the near future. PMID:23197083

  5. Peroxisomal Biogenesis in Ischemic Brain

    PubMed Central

    Young, Jennifer M.; Nelson, Jonathan W.; Cheng, Jian; Zhang, Wenri; Mader, Sarah; Davis, Catherine M.; Morrison, Richard S.

    2015-01-01

    Abstract Aims: Peroxisomes are highly adaptable and dynamic organelles, adjusting their size, number, and enzyme composition to changing environmental and metabolic demands. We determined whether peroxisomes respond to ischemia, and whether peroxisomal biogenesis is an adaptive response to cerebral ischemia. Results: Focal cerebral ischemia induced peroxisomal biogenesis in peri-infarct neurons, which was associated with a corresponding increase in peroxisomal antioxidant enzyme catalase. Peroxisomal biogenesis was also observed in primary cultured cortical neurons subjected to ischemic insult induced by oxygen-glucose deprivation (OGD). A catalase inhibitor increased OGD-induced neuronal death. Moreover, preventing peroxisomal proliferation by knocking down dynamin-related protein 1 (Drp1) exacerbated neuronal death induced by OGD, whereas enhancing peroxisomal biogenesis pharmacologically using a peroxisome proliferator-activated receptor-alpha agonist protected against neuronal death induced by OGD. Innovation: This is the first documentation of ischemia-induced peroxisomal biogenesis in mammalian brain using a combined in vivo and in vitro approach, electron microscopy, high-resolution laser-scanning confocal microscopy, and super-resolution structured illumination microscopy. Conclusion: Our findings suggest that neurons respond to ischemic injury by increasing peroxisome biogenesis, which serves a protective function, likely mediated by enhanced antioxidant capacity of neurons. Antioxid. Redox Signal. 22, 109–120. PMID:25226217

  6. An in vivo autotransplant model of renal preservation: cold storage versus machine perfusion in the prevention of ischemia/reperfusion injury.

    PubMed

    La Manna, Gaetano; Conte, Diletta; Cappuccilli, Maria Laura; Nardo, Bruno; D'Addio, Francesca; Puviani, Lorenza; Comai, Giorgia; Bianchi, Francesca; Bertelli, Riccardo; Lanci, Nicole; Donati, Gabriele; Scolari, Maria Piera; Faenza, Alessandro; Stefoni, Sergio

    2009-07-01

    There is increasing proof that organ preservation by machine perfusion is able to limit ischemia/reperfusion injury in kidney transplantation. This study was designed to compare the efficiency in hypothermic organ preservation by machine perfusion or cold storage in an animal model of kidney autotransplantation. Twelve pigs underwent left nephrectomy after warm ischemic time; the organs were preserved in machine perfusion (n = 6) or cold storage (n = 6) and then autotransplanted with immediate contralateral nephrectomy. The following parameters were compared between the two groups of animals: hematological and urine indexes of renal function, blood/gas analysis values, histological features, tissue adenosine-5'-triphosphate (ATP) content, perforin gene expression in kidney biopsies, and organ weight changes were compared before and after preservation. The amount of cellular ATP was significantly higher in organs preserved by machine perfusion; moreover, the study of apoptosis induction revealed an enhanced perforin expression in the kidneys, which underwent simple hypothermic preservation compared to the machine-preserved ones. Organ weight was significantly decreased after cold storage, but it remained quite stable for machine-perfused kidneys. The present model seems to suggest that organ preservation by hypothermic machine perfusion is able to better control cellular impairment in comparison with cold storage.

  7. Clinically-relevant reperfusion in acute ischemic stroke MTT performs better than Tmax and TTP

    PubMed Central

    Kong, Linglong; Zhu, Hongtu; Vo, Katie D.; Powers, William J.; Lin, Weili; Lee, Jin-Moo

    2014-01-01

    Background While several MRI parameters are used to assess tissue perfusion during hyperacute stroke, it is unclear which is optimal for measuring clinically-relevant reperfusion. We directly compared MTT prolongation (MTTp), TTP, and time-to-maximum (Tmax) to determine which best predicted neurological improvement and tissue salvage following early reperfusion. Methods Acute ischemic stroke patients underwent three MRI's: <4.5hr (tp1), at 6hr (tp2), and at 1 month after onset. Perfusion deficits at tp1 and tp2 were defined by MTTp, TTP, or Tmax beyond four commonly-used thresholds. Percent reperfusion (%Reperf) was calculated for each parameter and threshold. Regression analysis was used to fit %Reperf for each parameter and threshold as a predictor of neurological improvement [defined as admission National Institutes of Health Stroke Scale (NIHSS) – 1 month NIHSS (ΔNIHSS)] after adjusting for baseline clinical variables. Volume of reperfusion, for each parameter and threshold, was correlated with tissue salvage, defined as tp1 perfusion deficit volume – final infarct volume. Results 50 patients were scanned at 2.7 hours and 6.2 hours after stroke onset. %Reperf predicted ΔNIHSS for all MTTp thresholds, for Tmax > 6s and > 8s, but for no TTP thresholds. Tissue salvage significantly correlated with reperfusion for all MTTp thresholds and with Tmax > 6s, while there was no correlation with any TTP threshold. Among all parameters, reperfusion defined by MTTp was most strongly associated with ΔNIHSS (MTTp>3s, p=0.0002) and tissue salvage (MTTp> 3s and 4s, P<0.0001). Conclusion MTT-defined reperfusion was the best predictor of neurological improvement and tissue salvage in hyperacute ischemic stroke. PMID:24500786

  8. High-Performance Upconversion Nanoprobes for Multimodal MR Imaging of Acute Ischemic Stroke.

    PubMed

    Wang, Jing; Zhang, Hua; Ni, Dalong; Fan, Wenpei; Qu, Jianxun; Liu, Yanyan; Jin, Yingying; Cui, Zhaowen; Xu, Tianyong; Wu, Yue; Bu, Wenbo; Yao, Zhenwei

    2016-07-01

    Multimodal magnetic resonance (MR) imaging, including MR angiography (MRA) and MR perfusion (MRP), plays a critical role in the diagnosis and surveillance of acute ischemic stroke. However, these techniques are hindered by the low T1 relaxivity, short circulation time, and high leakage rate from vessels of clinical Magnevist. To address these problems, nontoxic polyethylene glycol (PEG)ylated upconversion nanoprobes (PEG-UCNPs) are synthesized and first adopted for excellent MRA and MRP imaging, featuring high diagnostic sensitivity toward acute ischemic stroke in high-resolution imaging. The investigations show that the agent possesses superior advantages over clinical Magnevist, such as much higher relaxivity, longer circulation time, and lower leakage rate, which guarantee much better imaging efficiency. Remarkably, an extremely small dosage (5 mg Gd kg(-1) ) of PEG-UCNPs provides high-resolution MRA imaging with the vascular system delineated much clearer than the Magnevist with clinical dosage as high as 108 mg Gd kg(-1) . On the other hand, the long circulation time of PEG-UCNPs enables the surveillance of the progression of ischemic stroke using MRA or MRP. Once translated, these PEG-UCNPs are expected to be a promising candidate for substituting the clinical Magnevist in MRA and MRP, which will significantly lengthen the imaging time window and improve the overall diagnostic efficiency. PMID:27219071

  9. Percutaneous isolated limb perfusion with thrombolytics for severe limb ischemia.

    PubMed

    Ali, Ahsan T; Kalapatapu, Venkat R; Bledsoe, Shelly; Moursi, Mohammed M; Eidt, John F

    2005-01-01

    Patients with severe tibioperoneal disease are poor candidates for a distal bypass. Absence of a distal target, lack of conduit, or multiple medical problems can make these patients a prohibitive risk for revascularization. Acute on chronic ischemia in this group poses a greater challenge. Thrombolytic therapy for acute ischemia can be prolonged and carries a significant risk of bleeding if continued beyond 24 hours. However, if the ischemic limbs can be isolated from the systemic circulation, a higher dose of the lytic agent can be given with lower risk. These are the initial results of a series of 10 patients who underwent percutaneous isolated limb perfusion with a high dose of thrombolytics for severe ischemia. Ten patients (lower extremity 8 and upper extremity 2) presented with severe limb-threatening ischemia. Mean ankle/brachial index (ABI) was 0.15 for the lower extremity, and there were no recordable digital pressures in patients with upper extremity ischemia. No distal target was visible on the initial arteriogram. These patients were then taken to the operating room, and under anesthesia, catheters were placed in an antegrade fashion via femoral approach in the popliteal artery and vein percutaneously. For upper extremity, the catheters were placed in the brachial artery and vein. A proximal tourniquet was then applied. This isolated the limb from the systemic circulation. Heparinized saline was infused through the arterial catheter while the venous catheter was left open. A closed loop or an isolated limb perfusion was confirmed when effluent became clear coming out of the venous port. A high dose of thrombolytic agent (urokinase 500,000 to 1,000,000 U) was infused into the isolated limb via the arterial catheter and drained out of the venous catheter. After 45 minutes, arterial flow was reestablished. In 4 patients, Reopro((R)) was used in addition to thrombolytics. Postprocedure angiograms showed minimal changes, but patients exhibited marked

  10. Early radionuclide scans for risk assessment in suspected acute myocardial infarction.

    PubMed Central

    Norris, S. L.; Haywood, L. J.; Sobel, E.; Hung, G. L.; deGuzman, M.; Siegel, M.

    1997-01-01

    First-day thallium-201 myocardial perfusion scans and technetium-99m RBC gated scintiangiography were performed during the initial clinical and prognostic evaluation of 69 patients with suspected acute myocardial infarction. Patients were monitored for clinical course, diagnosis confirmation, and use of specialty services (cardiac catheterization, percutaneous balloon angioplasty, and cardiac surgery) during hospitalization. Myocardial infarction, confirmed in 20 patients, was associated with significantly more left ventricular dilatation, lower ejection fractions, lower peak left ventricular filling rates, wall motion abnormalities, and thallium-201 perfusion defects than nonmyocardial infarction patients. Among all patients, left ventricular dilatation carried a relative risk of myocardial infarction of 5.8; low ejection fraction and right ventricular dilatation were strongly associated with myocardial infarction. A logistic model for congestive heart failure included: left ventricular dilation, lower mean left ventricular filling rates and time to peak filling rates, and abnormal thallium-201 lung:heart uptakes. Among nonmyocardial infarction patients, subsequent cardiac catheterization was predicted by the presence of anterior thallium-201 perfusion defects, Killip functional class II-III, and ischemia on ECG. These findings suggest that early detection of myocardial perfusion defects and cardiac dysfunction by radionuclide scans enhances initial evaluation of suspected acute myocardial infarction patients. Additional studies are needed to confirm these findings. PMID:9433058

  11. Comparison of radionuclide and enzymatic estimate of infarct size in patients with acute myocardial infarction

    SciTech Connect

    Hirsowitz, G.S.; Lakier, J.B.; Marks, D.S.; Lee, T.G.; Goldberg, A.D.; Goldstein, S.

    1983-06-01

    A comparison was made of the estimated size of the myocardial infarction occurring in 26 patients with a first infarction using creatine kinase (CK) enzyme release between radionuclide gated blood pool measurement of total and regional ventricular function and thallium-201 scintigraphic measurement of myocardial perfusion defects. Creatine kinase estimates of infarct size (enzymatic infarct size) correlated closely with the percent of abnormal contracting regions, left ventricular ejection fraction and thallium-201 estimates of percent of abnormal perfusion area (r . 0.78, 0.69 and 0.74, respectively, p less than 0.01). A close correlation also existed between percent abnormal perfusion area and percent of abnormal contracting regions (r . 0.81, p less than 0.01) and left ventricular ejection fraction (r . 0.69, p less than 0.01). Enzymatic infarct size was larger in anterior (116 +/- 37 CK-g-Eq) than inferior (52 +/- 29 CK-g-Eq) myocardial infarction (p less than 0.01) and was associated with significantly more left ventricular functional impairment as determined by left ventricular ejection fraction (33 +/- 7 versus 60 +/- 10%) (p less than 0.01) and percent abnormal perfusion area (58 +/- 14 versus 13 +/- 12) (p less than 0.01). No significant correlation was observed between enzymatic infarct size and right ventricular ejection fraction. These different methods of estimating infarct size correlated closely with each other in these patients with a first uncomplicated myocardial infarction.

  12. Tumor immunotargeting using innovative radionuclides.

    PubMed

    Kraeber-Bodéré, Françoise; Rousseau, Caroline; Bodet-Milin, Caroline; Mathieu, Cédric; Guérard, François; Frampas, Eric; Carlier, Thomas; Chouin, Nicolas; Haddad, Ferid; Chatal, Jean-François; Faivre-Chauvet, Alain; Chérel, Michel; Barbet, Jacques

    2015-01-01

    This paper reviews some aspects and recent developments in the use of antibodies to target radionuclides for tumor imaging and therapy. While radiolabeled antibodies have been considered for many years in this context, only a few have reached the level of routine clinical use. However, alternative radionuclides, with more appropriate physical properties, such as lutetium-177 or copper-67, as well as alpha-emitting radionuclides, including astatine-211, bismuth-213, actinium-225, and others are currently reviving hopes in cancer treatments, both in hematological diseases and solid tumors. At the same time, PET imaging, with short-lived radionuclides, such as gallium-68, fluorine-18 or copper-64, or long half-life ones, particularly iodine-124 and zirconium-89 now offers new perspectives in immuno-specific phenotype tumor imaging. New antibody analogues and pretargeting strategies have also considerably improved the performances of tumor immunotargeting and completely renewed the interest in these approaches for imaging and therapy by providing theranostics, companion diagnostics and news tools to make personalized medicine a reality. PMID:25679452

  13. Tumor Immunotargeting Using Innovative Radionuclides

    PubMed Central

    Kraeber-Bodéré, Françoise; Rousseau, Caroline; Bodet-Milin, Caroline; Mathieu, Cédric; Guérard, François; Frampas, Eric; Carlier, Thomas; Chouin, Nicolas; Haddad, Ferid; Chatal, Jean-François; Faivre-Chauvet, Alain; Chérel, Michel; Barbet, Jacques

    2015-01-01

    This paper reviews some aspects and recent developments in the use of antibodies to target radionuclides for tumor imaging and therapy. While radiolabeled antibodies have been considered for many years in this context, only a few have reached the level of routine clinical use. However, alternative radionuclides, with more appropriate physical properties, such as lutetium-177 or copper-67, as well as alpha-emitting radionuclides, including astatine-211, bismuth-213, actinium-225, and others are currently reviving hopes in cancer treatments, both in hematological diseases and solid tumors. At the same time, PET imaging, with short-lived radionuclides, such as gallium-68, fluorine-18 or copper-64, or long half-life ones, particularly iodine-124 and zirconium-89 now offers new perspectives in immuno-specific phenotype tumor imaging. New antibody analogues and pretargeting strategies have also considerably improved the performances of tumor immunotargeting and completely renewed the interest in these approaches for imaging and therapy by providing theranostics, companion diagnostics and news tools to make personalized medicine a reality. PMID:25679452

  14. Natural radionuclide accumulation by raindrops

    NASA Astrophysics Data System (ADS)

    Gusev, Anatoly; Martin, Inacio; Shkevov, Rumen; Alves, Mauro

    2016-07-01

    The laboratory of environmental radiation of ITA (São José dos Campos, 23°11'11″S, 45°52'43″W, 650 MAMSL) performs simultaneous monitoring of a natural radiation background and meteorological parameters. A time resolution of up to 1 minute allows a detailed comparison of changes in meteorological parameters with those of a concentration of ambient radon progenies in the atmosphere. Results of a study of variation of a fallout of radon progenies ^{214}Pb and ^{214}Bi concomitanting rainfalls are present. The radionuclide fallout rate is reconstructed from the observed gamma rate through a simulation of the first kind Volterra integral equation with difference kernel, determined by ratio of precipitating rates of 214Pb and 214Bi and their decay half times. An original straightforward step-by-step procedure was used for the numerical solution of the equation. The radionuclide concentration in the rainwater is calculated as a ratio of the reconstructed fallout to the measured rainfall. It was observed that the radionuclide fallout rate increases as the rainfall one in approximately power 0.6, i.e. the same as the mean raindrop volume. The concentration thereafter decreases as the rainfall rate in power 0.4. A numerical simulation of the process of accumulation of the radionuclides during diffusion and coalescence drop growth and aerosol scavenging during a passage from a cloud to the ground was performed. The results of the simulations agree with the experimental data.

  15. Centrifugal pump support for distal aortic perfusion during repair of traumatic thoracic aortic injury.

    PubMed

    Walls, Joseph T; Curtis, Jack J; McKenney-Knox, Charlotte A; Schmaltz, Richard A

    2002-11-01

    Paraplegia from ischemic injury of the spinal cord and renal failure from inadequate perfusion of the kidneys may occur from aortic cross-clamping during repair of traumatic thoracic aortic injuries. After Institutional Review Board approval, we retrospectively reviewed the charts of 26 patients surgically treated for traumatic transection of the descending thoracic aorta during a 14 year period (1987-2001), using centrifugal pump (Sarns) support for distal aortic perfusion. The study group comprised 19 males and 7 females, whose ages ranged from 15 to 69 years. For all but 1 patient, who fell from a flagpole, the injuries were incurred in motor vehicle accidents. Aortic cross-clamp time lasted between 5 to 78 min (median = 40 min). Mean arterial pressure ranged from 50 to 80 mm Hg (median = 70 mm Hg). All patients survived operation without developing paraplegia or renal failure. Distal centrifugal pump perfusion during repair of traumatic injury of the descending thoracic aorta is a valuable adjunct during surgical treatment and aids in preservation of spinal cord and renal function.

  16. Dynamic CT myocardial perfusion imaging: detection of ischemia in a porcine model with FFR verification

    NASA Astrophysics Data System (ADS)

    Fahmi, Rachid; Eck, Brendan L.; Vembar, Mani; Bezerra, Hiram G.; Wilson, David L.

    2014-03-01

    Dynamic cardiac CT perfusion (CTP) is a high resolution, non-invasive technique for assessing myocardial blood ow (MBF), which in concert with coronary CT angiography enable CT to provide a unique, comprehensive, fast analysis of both coronary anatomy and functional ow. We assessed perfusion in a porcine model with and without coronary occlusion. To induce occlusion, each animal underwent left anterior descending (LAD) stent implantation and angioplasty balloon insertion. Normal ow condition was obtained with balloon completely de ated. Partial occlusion was induced by balloon in ation against the stent with FFR used to assess the extent of occlusion. Prospective ECG-triggered partial scan images were acquired at end systole (45% R-R) using a multi-detector CT (MDCT) scanner. Images were reconstructed using FBP and a hybrid iterative reconstruction (iDose4, Philips Healthcare). Processing included: beam hardening (BH) correction, registration of image volumes using 3D cubic B-spline normalized mutual-information, and spatio-temporal bilateral ltering to reduce partial scan artifacts and noise variation. Absolute blood ow was calculated with a deconvolutionbased approach using singular value decomposition (SVD). Arterial input function was estimated from the left ventricle (LV) cavity. Regions of interest (ROIs) were identi ed in healthy and ischemic myocardium and compared in normal and occluded conditions. Under-perfusion was detected in the correct LAD territory and ow reduction agreed well with FFR measurements. Flow was reduced, on average, in LAD territories by 54%.

  17. Using intraoperative laser angiography to safeguard nipple perfusion in nipple-sparing mastectomies

    PubMed Central

    Dua, Monica M.; Bertoni, Danielle M.; Nguyen, Dung; Meyer, Shannon; Gurtner, Geoffrey C.

    2015-01-01

    The superior aesthetic outcomes of nipple-sparing mastectomies (NSM) explain their increased use and rising popularity. Fortunately, cancer recurrences involving the nipple-areolar complex (NAC) have been reassuringly low in the range of 1%. Technical considerations and challenges of this procedure are centered on nipple ischemia and necrosis. Patient selection, reconstructive strategies and incision placement have lowered ischemic complications. In this context, rates of full NAC necrosis are 3% or less. The emergence of noninvasive tissue angiography provides surgeons with a practical tool to assess real-time breast skin and NAC perfusion. Herein, we review our classification system of NAC perfusion patterns defined as V1 (from subjacent breast), V2 (surrounding skin), and V3 (combination of V1 + V2). Additionally, we describe the benefits of a first stage operation to devascularize the NAC as a means of improving blood flow to the NAC in preparation for NSM, helping extend the use of NSM to more women. Intraoperative evaluation of skin perfusion allows surgeons to detect ischemia and modify the operative approach to optimize outcomes. PMID:26645004

  18. Multimodal imaging of ischemic wounds

    NASA Astrophysics Data System (ADS)

    Zhang, Shiwu; Gnyawali, Surya; Huang, Jiwei; Liu, Peng; Gordillo, Gayle; Sen, Chandan K.; Xu, Ronald

    2012-12-01

    The wound healing process involves the reparative phases of inflammation, proliferation, and remodeling. Interrupting any of these phases may result in chronically unhealed wounds, amputation, or even patient death. Quantitative assessment of wound tissue ischemia, perfusion, and inflammation provides critical information for appropriate detection, staging, and treatment of chronic wounds. However, no method is available for noninvasive, simultaneous, and quantitative imaging of these tissue parameters. We integrated hyperspectral, laser speckle, and thermographic imaging modalities into a single setup for multimodal assessment of tissue oxygenation, perfusion, and inflammation characteristics. Advanced algorithms were developed for accurate reconstruction of wound oxygenation and appropriate co-registration between different imaging modalities. The multimodal wound imaging system was validated by an ongoing clinical trials approved by OSU IRB. In the clinical trial, a wound of 3mm in diameter was introduced on a healthy subject's lower extremity and the healing process was serially monitored by the multimodal imaging setup. Our experiments demonstrated the clinical usability of multimodal wound imaging.

  19. TECHNOLOGIES FOR RADON AND RADIONUCLIDE REMOVAL

    EPA Science Inventory

    This paper provides a summary of the technologies that are currently being used to remove radionuclides from drinking water. The radionuclides that are featured are the radionuclides currently regulated by EPA; radium, radon and uranium. Tehnologies effective for removal of eac...

  20. [Role of Radionuclide Technologies in Medicine].

    PubMed

    Chernyaev, A P; Belousov, A V; Varzar, S M; Borchegovskaya, P Y; Nikolaeva, A A; Krusanov, G A

    2016-01-01

    The paper describes the role of radionuclide technologies among the nuclear-physical methods used in medicine. The condition and prospects of the development of nuclear technology with use of radionuclides in medicine, and in particular, the method of brachytherapy are analyzed. The analysis of the current state of applying radionuclide facilities in medicine is provided.

  1. Measurement of radionuclides in waste packages

    DOEpatents

    Brodzinski, Ronald L.; Perkins, Richard W.; Rieck, Henry G.; Wogman, Ned A.

    1986-01-01

    A method is described for non-destructively assaying the radionuclide content of solid waste in a sealed container by analysis of the waste's gamma-ray spectrum and neutron emissions. Some radionuclides are measured by characteristic photopeaks in the gamma-ray spectrum; transuranic nuclides are measured by neutron emission rate; other radionuclides are measured by correlation with those already measured.

  2. Measurement of radionuclides in waste packages

    DOEpatents

    Brodzinski, R.L.; Perkins, R.W.; Rieck, H.G.; Wogman, N.A.

    1984-09-12

    A method is described for non-destructively assaying the radionuclide content of solid waste in a sealed container by analysis of the waste's gamma-ray spectrum and neutron emissions. Some radionuclides are measured by characteristic photopeaks in the gamma-ray spectrum; transuranic nuclides are measured by neutron emission rate; other radionuclides are measured by correlation with those already measured.

  3. Topical use of Rectogesic® and Emla® to improve cutaneous blood perfusion following thermal injury. A comparative experimental study.

    PubMed

    Tagkalakis, P; Dionyssopoulos, A; Karkavelas, G; Demiri, E

    2015-06-30

    Early post-burn ischemic necrosis of the skin is of particular interest in modern burn research. The purpose of this study was to test the hypothesis that blood perfusion could be improved by the topical application of vasoactive substances. A sample of 55 wistar rats was used to investigate the effect of 0,4% nitroglycerin ointment (Rectogesic(®)) comparatively to no application and placebo. The beneficiary action of 5% prilocaine/lidocaine cream (EMLA(®)) in burn blood perfusion was also tested comparatively to Rectogesic(®). Both preparations were tested respectively to non burned controls. Laser Doppler assessment of blood flow at 15, 30, 45, 60, 120 and 180 minutes after preparation application, demonstrated that the use of Rectogesic(®) improved perfusion at all measurements compared to placebo and to no preparation application (p&0,05). There was no statistical significant difference in the effect of the two preparations. PMID:27252612

  4. Topical use of Rectogesic® and Emla® to improve cutaneous blood perfusion following thermal injury. A comparative experimental study

    PubMed Central

    Tagkalakis, P.; Dionyssopoulos, A.; Karkavelas, G.; Demiri, E.

    2015-01-01

    Summary Early post-burn ischemic necrosis of the skin is of particular interest in modern burn research. The purpose of this study was to test the hypothesis that blood perfusion could be improved by the topical application of vasoactive substances. A sample of 55 wistar rats was used to investigate the effect of 0,4% nitroglycerin ointment (Rectogesic®) comparatively to no application and placebo. The beneficiary action of 5% prilocaine/lidocaine cream (EMLA®) in burn blood perfusion was also tested comparatively to Rectogesic®. Both preparations were tested respectively to non burned controls. Laser Doppler assessment of blood flow at 15, 30, 45, 60, 120 and 180 minutes after preparation application, demonstrated that the use of Rectogesic® improved perfusion at all measurements compared to placebo and to no preparation application (p&0,05). There was no statistical significant difference in the effect of the two preparations. PMID:27252612

  5. Radionuclide evaluation of left-ventricular function in chronic Chagas' cardiomyopathy

    SciTech Connect

    Arreaza, N.; Puigbo, J.J.; Acquatella, H. Casal, H.; Giordano, H.; Valecillos, R.; Mendoza, I.; Perez, J.F.; Hirschhaut, E.; Combellas, I.

    1983-07-01

    Left-ventricular ejection fraction (LVEF) and abnormalities of regional wall motion (WMA) were studied by means of radionuclide ventriculography in 41 patients prospectively diagnosed as having chronic Chagas' disease. Thirteen patients were asymptomatic (ASY), 16 were arrhythmic (ARR), and 12 had congestive heart failure (CHF). Mean LVEF was normal in ASY but markedly depressed in CHF. Regional WMAs were minimal in ASY and their severity increased in ARR. Most CHFs (75%) had diffuse hypokinesia of the left ventricle. Seven patients had a distinct apical aneurysm. Correlation between radionuclide and contrast ventriculography data was good in 17 patients. Selective coronary arteriography showed normal arteries in all patients. Therefore, chronic Chagas' heart disease joins ischemic heart disease as a cause of regional WMA.

  6. Protective effect of active perfusion in porcine models of acute myocardial ischemia.

    PubMed

    Feng, Zanxiang; Mao, Zhifu; Dong, Shengjun; Liu, Baohui

    2016-10-01

    in maintaining myocardial perfusion and alleviating ischemic injury when compared with traditional shunt perfusion. PMID:27573177

  7. Myocardial Perfusion MRI Using SW-CG-HYPR in Canine with Stenotic Coronary Arteries

    PubMed Central

    Ge, Lan; Kino, Aya; Lee, Daniel; Dharmakumar, Rohan; Carr, James C.; Li, Debiao

    2010-01-01

    Purpose First-pass perfusion MRI is a promising technique for detecting ischemic heart disease. However, the diagnostic value of the method is limited by the low spatial coverage, resolution, SNR, and cardiac motion related image artifacts. A combination of sliding window and CG-HYPR method has been proposed in healthy volunteer studies to reduce the acquisition window for each slice while maintaining the temporal resolution of one frame per heartbeat in myocardial perfusion MR imaging. This method allows for improved spatial coverage, resolution and SNR. Materials and Methods In this study, we use a controlled animal model to test whether the myocardial territory supplied by a stenotic coronary artery can be detected accurately by SW-CG-HYPR perfusion method under pharmacological stress. Results Results from six mongrel dogs (15–25 kg) studies demonstrate the feasibility of SW-CG-HYPR to detect regional perfusion defects. Using this method, the acquisition time per cardiac cycle was reduced by a factor of 4, and the spatial coverage was increased from 2–3 to 6 slices as compared to the conventional techniques including both turbo-FLASH and EPI. The SNR of the healthy myocardium at peak enhancement with SW-CG-HYPR (12.68±2.46) is significantly higher (p<0.01) than the turbo-FLASH (8.65±1.93) and EPI (5.48±1.24). The spatial resolution of SW-CG-HYPR images is 1.2×1.2×8.0 mm3, which is better than the turbo-FLASH (1.8×1.8×8.0 mm3) and EPI (2.0×1.8×8.0 mm3). Conclusion SW-CG-HYPR is a promising technique for myocardial perfusion MRI. This technique provides higher image quality with respect to significantly improved SNR and spatial resolution of the myocardial perfusion images, which might improve myocardial perfusion imaging in a clinical setting. PMID:20861770

  8. Protective effect of active perfusion in porcine models of acute myocardial ischemia

    PubMed Central

    Feng, Zanxiang; Mao, Zhifu; Dong, Shengjun; Liu, Baohui

    2016-01-01

    ischemic injury when compared with traditional shunt perfusion. PMID:27573177

  9. Real-time monitoring of nitric oxide in ischemic myocardium using an NO-selective electrode calibrated by electron spin resonance.

    PubMed

    Takahashi, Shun-suke; Omori, Yoichi; Miyazaki, Hiroyuki; Yoshino, Fumihiko; Shoji, Hirofumi; Lee, Masaichi-Chang-il; Todoki, Kazuo; Kamibayashi, Masato; Murakami, Eiichi

    2003-11-21

    Using a Langendorff-perfused rat heart preparation and selective electrodes, we determined nitric oxide (NO) and oxygen levels in cardiac tissue. An NO-selective electrode that was calibrated by electron spin resonance (ESR) spectroscopy was inserted into the middle of the myocardium in the left ventricle. Simultaneously, we used an O2-selective electrode to measure the partial pressure of oxygen (pO2) in the perfusate, Krebs-Henseleit (K-H) solution, that was ejected from the heart. After 30 min of aerobic control perfusion, hearts were subjected to 30 min of global ischemia followed by 30 min of reperfusion. Under ischemic conditions, with a gradually decreasing pO2, NO detected by an NO-sensitive electrode within the myocardium was gradually increased. The maximum concentration increases in NO and decreases in pO2 during global ischemia were +10.200 +/- 1.223 microM and -58.608 +/- 4.123 mmHg, respectively. NO and pO2 levels both recovered to pre-ischemia baseline values when perfusion was restarted after global ischemia (reperfusion). The presence of Nomega-nitro-L-arginine methyl ester (L-NAME, 10 mM), a NOS inhibitor, prevented ischemia/reperfusion-induced changes in NO. This study shows that an NO-selective electrode that is calibrated by ESR can provide accurate, real-time monitoring of cardiac NO in normal and ischemic myocardium.

  10. Inhibition of Notch signaling by Dll4-Fc promotes reperfusion of acutely ischemic tissues

    SciTech Connect

    Liu, Ren; Trindade, Alexandre; Sun, Zhanfeng; Kumar, Ram; Weaver, Fred A.; Krasnoperov, Valery; Naga, Kranthi; Duarte, Antonio; Gill, Parkash S.

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer Low dose Dll4-Fc increases vascular proliferation and overall perfusion. Black-Right-Pointing-Pointer Low dose Dll4-Fc helps vascular injury recovery in hindlimb ischemia model. Black-Right-Pointing-Pointer Low dose Dll4-Fc helps vascular injury recovery in skin flap model. Black-Right-Pointing-Pointer Dll4 heterozygous deletion promotes vascular injury recovery. Black-Right-Pointing-Pointer Dll4 overexpression delays vascular injury recovery. -- Abstract: Notch pathway regulates vessel development and maturation. Dll4, a high-affinity ligand for Notch, is expressed predominantly in the arterial endothelium and is induced by hypoxia among other factors. Inhibition of Dll4 has paradoxical effects of reducing the maturation and perfusion in newly forming vessels while increasing the density of vessels. We hypothesized that partial and/or intermittent inhibition of Dll4 may lead to increased vascular response and still allow vascular maturation to occur. Thus tissue perfusion can be restored rapidly, allowing quicker recovery from ischemia or tissue injury. Our studies in two different models (hindlimb ischemia and skin flap) show that inhibition of Dll4 at low dose allows faster recovery from vascular and tissue injury. This opens a new possibility for Dll4 blockade's therapeutic application in promoting recovery from vascular injury and restoring blood supply to ischemic tissues.

  11. Ischemic perinatal stroke: challenge and opportunities.

    PubMed

    Raju, Tonse N K

    2008-08-01

    The second highest risk group for developing a cerebral stroke is the perinatal period, generally defined as 20 weeks of gestation through 28th postnatal day of age. In this commentary, a brief overview of ischemic perinatal strokes is presented. Ischemic perinatal stroke (IPS) occurs at a rate of 1 : 2300 to 1 : 5000 births, accounting for 30% of children with hemiplegic cerebral palsy (CP). Thus, IPS is the most common known cause for CP [1-3]. Although they occur frequently, much remains to be studied about perinatal strokes in general and the ischemic variety in particular. PMID:18705894

  12. Quantification of myocardial salvage by myocardial perfusion SPECT and cardiac magnetic resonance--reference standards for ECG development.

    PubMed

    Engblom, Henrik; Aletras, Anthony H; Heiberg, Einar; Arheden, Håkan; Carlsson, Marcus

    2014-01-01

    In order to determine the cardioprotective efficacy of acute reperfusion therapy, assessed as myocardial salvage, in patients with acute coronary occlusion, the final myocardial infarct (MI) size needs to be related to the amount of ischemic myocardium during coronary occlusion, referred to as the myocardium at risk (MaR). There are currently several imaging approaches available for quantification of both MI size and MaR in vivo of which some have been validated both in pre-clinical and clinical settings. These methods often involve the use of either myocardial perfusion SPECT or cardiac magnetic resonance (CMR). These imaging methods could potentially be used to further develop and validate ECG methods for determination of MI size and MaR. Therefore, the aim of the present review is to give an overview of myocardial perfusion SPECT and CMR methods available for assessment of myocardial salvage by determination of MI size and MaR.

  13. Identification of CSF fistulas by radionuclide counting

    SciTech Connect

    Yamamoto, Y.; Kunishio, K.; Sunami, N.; Yamamoto, Y.; Satoh, T.; Suga, M.; Asari, S. )

    1990-07-01

    A radionuclide counting method, performed with the patient prone and the neck flexed, was used successfully to diagnose CSF rhinorrhea in two patients. A normal radionuclide ratio (radionuclide counts in pledget/radionuclide counts in 1-ml blood sample) was obtained in 11 normal control subjects. Significance was determined to be a ratio greater than 0.37. Use of radionuclide counting method of determining CSF rhinorrhea is recommended when other methods have failed to locate a site of leakage or when posttraumatic meningitis suggests subclinical CSF rhinorrhea.

  14. Non-invasive measurement of coronary flow reserve: uniqueness of radionuclide methods and alternative techniques.

    PubMed

    Bauckneht, Matteo; Piva, Roberta; Ferrarazzo, Giulia; Ceriani, Valentina; Buschiazzo, Ambra; Morbelli, Silvia; Marini, Cecilia; Sambuceti, Gianmario

    2016-12-01

    Over the last several decades, radionuclide Myocardial Perfusion Imaging (MPI) has been a mainstay for the evaluation of coronary artery disease (CAD), based on the assumption that a detailed knowledge of stenosis localization and severity is not sufficient for clinical decision making. Furthermore, radionuclide MPI diagnostic accuracy has been implemented by the assessment of Coronary Flow Reserve (CFR) and Myocardial Blood Flow (MBF), as quantitative indexes of stenosis severity and surrogates of total ischaemic burden. Several considerations indicate that these measurement actually improve description of coronary physiology with respect to conventional qualitative image analysis. However, several alternative approaches have been optimized and increasingly proposed to achieve this task in the clinical setting. The aim of the present narrative review is to discuss strengths and weaknesses of the various cardiac modalities proposed to define CFR and MBF in the era of multi-modality imaging. PMID:27611708

  15. Non-invasive measurement of coronary flow reserve: uniqueness of radionuclide methods and alternative techniques.

    PubMed

    Bauckneht, Matteo; Piva, Roberta; Ferrarazzo, Giulia; Ceriani, Valentina; Buschiazzo, Ambra; Morbelli, Silvia; Marini, Cecilia; Sambuceti, Gianmario

    2016-12-01

    Over the last several decades, radionuclide Myocardial Perfusion Imaging (MPI) has been a mainstay for the evaluation of coronary artery disease (CAD), based on the assumption that a detailed knowledge of stenosis localization and severity is not sufficient for clinical decision making. Furthermore, radionuclide MPI diagnostic accuracy has been implemented by the assessment of Coronary Flow Reserve (CFR) and Myocardial Blood Flow (MBF), as quantitative indexes of stenosis severity and surrogates of total ischaemic burden. Several considerations indicate that these measurement actually improve description of coronary physiology with respect to conventional qualitative image analysis. However, several alternative approaches have been optimized and increasingly proposed to achieve this task in the clinical setting. The aim of the present narrative review is to discuss strengths and weaknesses of the various cardiac modalities proposed to define CFR and MBF in the era of multi-modality imaging.

  16. Lasers in the treatment of ischemic heart disease in China

    NASA Astrophysics Data System (ADS)

    Zhang, Yongzhen; Chen, Mingzhe

    2000-10-01

    Myocardial revascularization by laser is a new treatment modality for chronic, severe, refractory angina in the patients with coronary heart disease that is not amenable to angioplasty (PTCA) or bypass surgery (CABG). Transmyocardial revascularization (TMR), typically requiring open thoracotomy, uses laser to create channels that would directly carry blood from left ventricular cavity into the ischemic myocardium. Current data indicate that TMR may provide these patients with improvement in angina severity, quality of life, and myocardial perfusion. The greatest potential future use of TMR is as an adjunct to CABG in patients with disease that prevents bypass grafting due to lack of distal targets or a conduit. Recently, as percutaneous (catheter-based) myocardial revascularization (PMR) has been developed with laser technology that permits the creation of channels from the endocardial surface of the left ventricle. The early results with PMR seem encouraging. Randomized clinical trial has demonstrated symptomatic improvement and increased exercise capacity. The risk: benefit ratio for PMR appears to be much more favorable than that for TMR. The mechanisms of action of them have not yet been clearly elucidated, and several theories have been proposed, including channel patency, angiogenesis, denervation, and placebo effect. The challenge of TMR/PMR is related to improvement of perioperative outcomes and long-term survival without worsening of left ventricular function. In future, it may be feasible to combine TMR/PMR with intramyocardial delivery of angiogenic growth factors to induce further new blood vessel formation.

  17. Applications of laser in ischemic heart disease in China

    NASA Astrophysics Data System (ADS)

    Chen, Mingzhe; Zhang, Yongzhen

    1999-09-01

    Current data demonstrate that laser coronary angioplasty is most useful in complex lesions not well suited for percutaneous transluminal coronary angioplasty (PTCA). It is not `stand-alone' procedure, and should be considered an adjunct to PTCA or stenting. To date, there are not data supporting reduction of restenosis. Direct myocardial revascularization (DMR), either transmyocardial revascularization (TMR) or percutaneous (catheter-based) myocardial revascularization (PMR), uses laser to create channels between ischemic myocardium and left ventricular cavity. Candidates include patients with chronic, severe, refractory angina and those unable to undergo angioplasty or bypass surgery because conduits or acceptable target vessels are lacking. Although the mechanisms of action of DMR have not yet been clearly elucidated, but several theories have been proposed, including channel patency, angiogenesis, and denervation. TMR, typically requiring open thoracotomy, is effective for improving myocardial perfusion and reducing angina. Pilot studies demonstrate that clinical application of PMR is feasible and safe and effective for decreasing angina. Late sequelae also remain to be determined. An ongoing randomized clinical trial is comparing PMR with conventional medical therapy in patients with severe, refractory angina and disease unamenable to angioplasty or bypass surgery.

  18. The cyclooxygenase-2 selective inhibitor, etodolac, but not aspirin reduces neovascularization in a murine ischemic hind limb model.

    PubMed

    Tanaka, Kohei; Yamamoto, Yasutaka; Tsujimoto, Shunsuke; Uozumi, Naonori; Kita, Yoshihiro; Yoshida, Akio; Shimizu, Takao; Hisatome, Ichiro

    2010-02-10

    Cyclooxygenase inhibitors are often prescribed to relieve severe ischemic leg pain in critical ischemic limb patients. Prescription of high doses of aspirin and selective cyclooxygenase-2 inhibitors is reported to increase cardiovascular events through suppression of the vasodilative prostanoid prostaglandin I(2) in endothelium. Here, we evaluated the influence of aspirin and etodolac, a selective cyclooxygenase-2 inhibitor, on neovascularization using a murine ischemia hind limb model. C57BL/6J mice were treated with aspirin or etodolac for twenty-eight days after induction of ischemia. We exploited a concentration of the agents that suppressed cyclooxygenase activity efficiently, especially in prostaglandin I(2) production. Recovery of limb blood perfusion and capillary density in ischemic limbs was significantly suppressed by etodolac treatment when compared to the aspirin treated group and untreated group. Production of 6-keto prostaglandin F(1alpha) and prostaglandin E(2) was lower in the aspirin treated group when compared with the etodolac-treated group. Also, these concentrations were lower in both treatment groups compared with the untreated group. Immunohistochemical analysis suggested cyclooxygenase-2 was expressed in endothelium but not in inflammatory cells in ischemic tissue from the acute to chronic phase. Cyclooxygenase-1 was expressed strongly in inflammatory cells in the acute phase. Furthermore, bone marrow-derived mononuclear cell transplantation improved neovascularization, whereas aspirin and etodolac did not inhibit these effects. Production of arachidonic acid metabolites by transplanted cells was independent of the improvement of neovascularization. In conclusion, cyclooxygenase-2 inhibition reduces ischemia-induced neovascularization. PMID:19879866

  19. Local Injection of Deferoxamine Improves Neovascularization in Ischemic Diabetic Random Flap by Increasing HIF-1α and VEGF Expression

    PubMed Central

    Zhang, Yun; Xiong, Zhuyou; Li, Guangzao; Cui, Lei

    2014-01-01

    Background Although the systemic administration of deferoxamine (DFO) is protective in experimental models of normal ischemic flap and diabetic wound, its effect on diabetic flap ischemia using a local injection remains unknown. Objective To explore the feasibility of local injection of DFO to improve the survival of ischemic random skin flaps in streptozotocin (STZ)-induced diabetic mice. Methods Ischemic random skin flaps were made in 125 mice. Animals were divided into the DFO-treated (n = 20), PBS-treated (n = 16) and untreated (n = 16) groups. Surviving area, vessel density, and expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α (HIF-1α) were evaluated on the seventh day after local injection. Results The viability of DFO-treated flap was significantly enhanced, with increased regional blood perfusion and capillary density compared with those in the two control groups. Fluorescence-activated cell sorting (FACS) analysis demonstrated a marked increase in systemic Flk-1+/CD11b− endothelial progenitor cells (EPCs) in DFO-treated mice. Furthermore, the expression of VEGF and HIF-1α was increased not only in diabetic flap tissue, but also in dermal fibroblasts cultured under hyperglycemic and hypoxic conditions. Conclusions Local injection of DFO could exert preventive effects against skin flap necrosis in STZ-induced diabetic mice by elevating the expression of HIF-1α and VEGF, increased EPC mobilization, which all contributed to promote ischemic diabetic flap survival. PMID:24963878

  20. Early whole-brain CT perfusion for detection of patients at risk for delayed cerebral ischemia after subarachnoid hemorrhage.

    PubMed

    Malinova, Vesna; Dolatowski, Karoline; Schramm, Peter; Moerer, Onnen; Rohde, Veit; Mielke, Dorothee

    2016-07-01

    OBJECT This prospective study investigated the role of whole-brain CT perfusion (CTP) studies in the identification of patients at risk for delayed ischemic neurological deficits (DIND) and of tissue at risk for delayed cerebral infarction (DCI). METHODS Forty-three patients with aneurysmal subarachnoid hemorrhage (aSAH) were included in this study. A CTP study was routinely performed in the early phase (Day 3). The CTP study was repeated in cases of transcranial Doppler sonography (TCD)-measured blood flow velocity (BFV) increase of > 50 cm/sec within 24 hours and/or on Day 7 in patients who were intubated/sedated. RESULTS Early CTP studies revealed perfusion deficits in 14 patients, of whom 10 patients (72%) developed DIND, and 6 of these 10 patients (60%) had DCI. Three of the 14 patients (21%) with early perfusion deficits developed DCI without having had DIND, and the remaining patient (7%) had neither DIND nor DCI. There was a statistically significant correlation between early perfusion deficits and occurrence of DIND and DCI (p < 0.0001). A repeated CTP was performed in 8 patients with a TCD-measured BFV increase > 50 cm/sec within 24 hours, revealing a perfusion deficit in 3 of them (38%). Two of the 3 patients (67%) developed DCI without preceding DIND and 1 patient (33%) had DIND without DCI. In 4 of the 7 patients (57%) who were sedated and/or comatose, additional CTP studies on Day 7 showed perfusion deficits. All 4 patients developed DCI. CONCLUSIONS Whole-brain CTP on Day 3 after aSAH allows early and reliable identification of patients at risk for DIND and tissue at risk for DCI. Additional CTP investigations, guided by TCD-measured BFV increase or persisting coma, do not contribute to information gain.

  1. Cochlear perfusion with a viscous fluid.

    PubMed

    Wang, Yi; Olson, Elizabeth S

    2016-07-01

    The flow of viscous fluid in the cochlea induces shear forces, which could provide benefit in clinical practice, for example to guide cochlear implant insertion or produce static pressure to the cochlear partition or wall. From a research standpoint, studying the effects of a viscous fluid in the cochlea provides data for better understanding cochlear fluid mechanics. However, cochlear perfusion with a viscous fluid may damage the cochlea. In this work we studied the physiological and anatomical effects of perfusing the cochlea with a viscous fluid. Gerbil cochleae were perfused at a rate of 2.4 μL/min with artificial perilymph (AP) and sodium hyaluronate (Healon, HA) in four different concentrations (0.0625%, 0.125%, 0.25%, 0.5%). The different HA concentrations were applied either sequentially in the same cochlea or individually in different cochleae. The perfusion fluid entered from the round window and was withdrawn from basal scala vestibuli, in order to perfuse the entire perilymphatic space. Compound action potentials (CAP) were measured after each perfusion. After perfusion with increasing concentrations of HA in the order of increasing viscosity, the CAP thresholds generally increased. The threshold elevation after AP and 0.0625% HA perfusion was small or almost zero, and the 0.125% HA was a borderline case, while the higher concentrations significantly elevated CAP thresholds. Histology of the cochleae perfused with the 0.0625% HA showed an intact Reissner's membrane (RM), while in cochleae perfused with 0.125% and 0.25% HA RM was torn. Thus, the CAP threshold elevation was likely due to the broken RM, likely caused by the shear stress produced by the flow of the viscous fluid. Our results and analysis indicate that the cochlea can sustain, without a significant CAP threshold shift, up to a 1.5 Pa shear stress. Beside these finding, in the 0.125% and 0.25% HA perfusion cases, a temporary CAP threshold shift was observed, perhaps due to the presence and

  2. Cochlear perfusion with a viscous fluid.

    PubMed

    Wang, Yi; Olson, Elizabeth S

    2016-07-01

    The flow of viscous fluid in the cochlea induces shear forces, which could provide benefit in clinical practice, for example to guide cochlear implant insertion or produce static pressure to the cochlear partition or wall. From a research standpoint, studying the effects of a viscous fluid in the cochlea provides data for better understanding cochlear fluid mechanics. However, cochlear perfusion with a viscous fluid may damage the cochlea. In this work we studied the physiological and anatomical effects of perfusing the cochlea with a viscous fluid. Gerbil cochleae were perfused at a rate of 2.4 μL/min with artificial perilymph (AP) and sodium hyaluronate (Healon, HA) in four different concentrations (0.0625%, 0.125%, 0.25%, 0.5%). The different HA concentrations were applied either sequentially in the same cochlea or individually in different cochleae. The perfusion fluid entered from the round window and was withdrawn from basal scala vestibuli, in order to perfuse the entire perilymphatic space. Compound action potentials (CAP) were measured after each perfusion. After perfusion with increasing concentrations of HA in the order of increasing viscosity, the CAP thresholds generally increased. The threshold elevation after AP and 0.0625% HA perfusion was small or almost zero, and the 0.125% HA was a borderline case, while the higher concentrations significantly elevated CAP thresholds. Histology of the cochleae perfused with the 0.0625% HA showed an intact Reissner's membrane (RM), while in cochleae perfused with 0.125% and 0.25% HA RM was torn. Thus, the CAP threshold elevation was likely due to the broken RM, likely caused by the shear stress produced by the flow of the viscous fluid. Our results and analysis indicate that the cochlea can sustain, without a significant CAP threshold shift, up to a 1.5 Pa shear stress. Beside these finding, in the 0.125% and 0.25% HA perfusion cases, a temporary CAP threshold shift was observed, perhaps due to the presence and

  3. Temperature controlled machine perfusion system for liver.

    PubMed

    Obara, H; Matsuno, N; Shigeta, T; Hirano, T; Enosawa, S; Mizunuma, H

    2013-06-01

    Organ preservation using machine perfusion is an effective method compared with conventional preservation techniques using static cold storage. A newly developed MP preservation system to control perfusate temperatures from hypothermic to subnormothermic conditions is introduced. This system is useful not only for liver preservation, but also for evaluation of graft viability for recovery. This novel method has been proposed for preservation of porcine liver grafts. An innovative preservation system is especially important to obtain viable organs from extended criteria or donation after cardiac death donors. In this study, we introduce a new machine perfusion preservation system (NES-01) to evaluate graft viability for recovery of liver functions, using porcine grafts.

  4. Vascular regeneration effect of adipose-derived stem cells with light-emitting diode phototherapy in ischemic tissue.

    PubMed

    Park, In-Su; Mondal, Arindam; Chung, Phil-Sang; Ahn, Jin Chul

    2015-02-01

    The objective of this study was to investigate the effects on the vascular regeneration of adipose-derived stem cells (ASCs) by using red light-emitting diode (LED) irradiation in ischemic hind limbs. Low-level light therapy (LLLT) has been shown to enhance proliferation and cytokine secretion of a number of cells. ASCs are an attractive cell source for vascular tissue engineering. This approach is hindered because transplanted ASCs decline rapidly in the recipient tissue. Ischemic hind limbs were treated with LLLT from an LED array (660 nm) at an irradiance of 50 mW/cm(2) and a radiant exposure of 30 J/cm(2). LLLT, ASC transplantation, and ASC transplantation with LLLT (ASC + LLLT) were applied to ischemic limbs, and cell survival and differentiation, and secretion of vascular endothelial growth factor and basic fibroblast growth factor of the ASCs were evaluated by immunostaining and Western blot analyses. Vascular regeneration was assessed by immunostaining and hematoxylin and eosin staining. In the ASC + LLLT group, the survival of ASCs was increased due to the decreased apoptosis of ASCs. The secretion of growth factors was stimulated in this group compared with ASCs alone. The ASC + LLLT group displayed improved treatment efficacy including neovascularization and tissue regeneration compared with ASCs alone. In particular, quantitative analysis of laser Doppler blood perfusion image ratio showed that blood perfusion was enhanced significantly (p < 0.05) by ASC + LLLT treatment. These data suggest that LLLT is an effective biostimulator of ASCs in vascular regeneration, which enhances the survival of ASCs and stimulates the secretion of growth factors in ischemic limbs.

  5. Patterns of disturbed myocardial perfusion in patients with coronary artery disease. Regional myocardial perfusion in angina pectoris

    SciTech Connect

    Selwyn, A.P.; Forse, G.; Fox, K.; Jonathan, A.; Steiner, R.

    1981-07-01

    Fifty patients who presented with angina pectoris were studied to examine the disturbances of regional myocardial perfusion during stress. Each patient underwent 16-point precordial mapping of the ECG during an exercise test, and coronary and left ventricular angiography. Regional myocardial perfusion was assessed using an atrial pacing test and a short-lived radionuclide, krypton-81m. Eleven patients had negative exercise tests and uniform increases in myocardial activity of krypton-81m of 98 +/- 18.0% during pacing. Ten patients performed 30,000-43,000 J in positive exercise tests. These patients showed abnormal coronary anatomy and increases in myocardial activity of krypton-81m to remote and jeopardized myocardium at the onset of pacing. However, further pacing produced a decrease in activity in the affected segment of 68.0 +/- 9.0% accompanied by ST-segment depression and angina. Twelve patients achieved 26,000-32,000 J in positive exercise tests and had significant coronary artery disease. Atrial pacing produced increased activity of krypton-81m to remote myocardium. The jeopardized segment at first showed no change and then a decrease in regional activity of krypton-81m (89.0 +/- 17%) accompanied by ST-segment depression and chest pain. Seventeen patients achieved only 7000-22,000 J in positive exercise tests. These patients showed abnormal coronary anatomy and developed decreases in regional activity of krypton-81m to the affected segment of myocardium starting at the onset of atrial pacing and decreasing by 88 +/- 0 7.0% below control. We conclude that different patterns of disturbed myocardial distribution of krypton-81m are present during stress-induced ischemia in patients with coronary artery disease. There was a close temporal relationship between these disturbances and ST-segment depression.

  6. Morbidity of ischemic heart disease in early breast cancer 15-20 years after adjuvant radiotherapy

    SciTech Connect

    Gyenes, G.; Rutqvist, L.E. ); Fornander, T.; Carlens, P.

    1994-03-30

    The purpose of this study was to assess the cardiac side effects, primarily the occurrence of ischemic heart disease, in symptom-free patients with early breast cancer treated with radiotherapy. Thirty-seven survivors of a former randomized study of early breast cancer were examined. Twenty patients irradiated pre- or postoperatively for left sided disease (study group patients) were compared with 17 controls who were either treated for right sided disease, or were nonirradiated patients. Radiotherapy was randomized in the original study; either tangential field [sup 60]Co, or electron-therapy was delivered. Echocardiography and bicycle ergometry stress test with [sup 99m]Tc SestaMIBI myocardial perfusion scintigraphy were carried out and the patients' major risk factors for ischemic heart disease were also listed. Our results showed a significant difference between the scintigraphic findings of the two groups. Five of the 20 study group patients (25%), while none of the 17 controls exhibited some kind of significant defects on scintigraphy, indicating ischemic heart disease (p < 0.05). No deterioration in left ventricular systolic and/or diastolic function could be detected by echocardiography. Radiotherapy for left sided breast cancer with the mentioned treatment technique may present as an independent risk factor in the long-term development of ischemic heart disease, while left ventricular dysfunction could not be related to the previous irradiation. The authors emphasize the need to optimize adjuvant radiotherapy for early breast cancer by considering the dose both to the heart as well as the cancer. 39 refs., 4 tabs.

  7. Pertussis toxin reduces calcium influx to protect ischemic stroke in a middle cerebral artery occlusion model.

    PubMed

    Tang, Zhiwei; Li, Shiping; Han, Pengcheng; Yin, Junxiang; Gan, Yan; Liu, Qingwei; Wang, Jinkun; Wang, Chongqian; Li, Yu; Shi, Jiong

    2015-12-01

    Increased calcium influx secondary to glutamate induced excitotoxicity initiates and potentiates devastating pathological changes following ischemic stroke. Pertussis toxin (PTx), a G-protein blocker, is known to suppress intracellular calcium accumulation. We hypothesize that PTx can protect against stroke by blocking calcium influx. In a permanent middle cerebral artery occlusion model, PTx (1000 ng) was given intraperitoneally 30 min after inducing stroke. Magnetic Resonance Imaging of perfusion and T2-weighted brain scans were obtained to evaluate cerebral blood flow (CBF) and infarct volume. Primary neuronal culture was used to test glutamate induced excitotoxicity and calcium influx. We established a non-linear exponential curve model to minimize variations in animal cerebrovasculature. A reduction of 40-60% in relative CBF was a critical window where infarct volume started to increase as rCBF reduced. PTx showed maximal effects in reducing infarct volume at this window. In vitro studies further demonstrated PTx increased neuronal cell survival by decreasing glutamate-induced calcium influx into neurons and preventing neurons from apoptosis. PTx salvages the ischemic penumbra by blocking calcium influx. This provides us a new mechanism upon which experimental therapies can be explored to treat ischemic stroke. In ischemic stroke, excessive glutamate binds to AMPA receptor that depolarizes calcium channel and/ or NMDA receptor. Both of them allow calcium to enter the cell. The overload of calcium triggers cellular cascade that includes Caspase activation and release, leading to pre-mature cell death. We have demonstrated that PTx, a G-protein inhibitor, blocks calcium entry which in turn prevents further cellular damage.

  8. Activation of Hypoxia Response in Endothelial Cells Contributes to Ischemic Cardioprotection

    PubMed Central

    Kerkelä, Risto; Karsikas, Sara; Szabo, Zoltan; Serpi, Raisa; Magga, Johanna; Gao, Erhe; Alitalo, Kari; Anisimov, Andrey; Sormunen, Raija; Pietilä, Ilkka; Vainio, Laura; Koch, Walter J.; Kivirikko, Kari I.; Myllyharju, Johanna

    2013-01-01

    Small-molecule inhibition of hypoxia-inducible factor prolyl 4-hydroxylases (HIF-P4Hs) is being explored for the treatment of anemia. Previous studies have suggested that HIF-P4H-2 inhibition may also protect the heart from an ischemic insult. Hif-p4h-2gt/gt mice, which have 76 to 93% knockdown of Hif-p4h-2 mRNA in endothelial cells, fibroblasts, and cardiomyocytes and normoxic stabilization of Hif-α, were subjected to ligation of the left anterior descending coronary artery (LAD). Hif-p4h-2 deficiency resulted in increased survival, better-preserved left ventricle (LV) systolic function, and a smaller infarct size. Surprisingly, a significantly larger area of the LV remained perfused during LAD ligation in Hif-p4h-2gt/gt hearts than in wild-type hearts. However, no difference was observed in collateral vessels, while the size of capillaries, but not their number, was significantly greater in Hif-p4h-2gt/gt hearts than in wild-type hearts. Hif-p4h-2gt/gt mice showed increased cardiac expression of endothelial Hif target genes for Tie-2, apelin, APJ, and endothelial nitric oxide (NO) synthase (eNOS) and increased serum NO concentrations. Remarkably, blockage of Tie-2 signaling was sufficient to normalize cardiac apelin and APJ expression and resulted in reversal of the enlarged-capillary phenotype and ischemic cardioprotection in Hif-p4h-2gt/gt hearts. Activation of the hypoxia response by HIF-P4H-2 inhibition in endothelial cells appears to be a major determinant of ischemic cardioprotection and justifies the exploration of systemic small-molecule HIF-P4H-2 inhibitors for ischemic heart disease. PMID:23775121

  9. Identification of ischemic and hibernating myocardium: feasibility of post-exercise F-18 deoxyglucose positron emission tomography

    SciTech Connect

    Marwick, T.H.; MacIntyre, W.J.; Salcedo, E.E.; Go, R.T.; Saha, G.; Beachler, A. )

    1991-02-01

    The identification of ischemic and hibernating myocardium facilitates the selection of patients most likely to benefit from revascularization. This study examined the feasibility of metabolic imaging, using post-exercise F-18 deoxyglucose positron emission tomography (FDG-PET) for the diagnosis of both ischemia and hibernation in 27 patients with known coronary anatomy. Normal post-exercise FDG uptake was defined in each patient by reference to normal resting perfusion and normal coronary supply. Abnormal elevation of FDG (ischemia or hibernation) was compared in 13 myocardial segments in each patient, with the results of dipyridamole stress perfusion imaging performed by rubidium-82 positron emission tomography (Rb-PET). Myocardial ischemia was diagnosed by either FDG-PET or Rb-PET in 34 segments subtended by significant local coronary stenoses. Increased FDG uptake was present in 32/34 (94%) and a reversible perfusion defect was identified by Rb-PET in 22/34 (65%, p less than .01). In 3 patients, ischemia was identified by metabolic imaging alone. In 16 patients with previous myocardial infarction, perfusion defects were present at rest in 89 regions, 30 of which (34%) demonstrated increased FDG uptake, consistent with the presence of hibernation. Increased post-exercise FDG uptake appears to be a sensitive indicator of ischemia and myocardial hibernation. Increased post-exercise FDG uptake, appears to be a sensitive indicator of ischemia and myocardial hibernation. This test may be useful in selecting post-infarction patients for revascularization.

  10. Diluted Blood Reperfusion as a Model for Transplantation of Ischemic Rat Livers: ALT is a Direct Indicator of Viability

    PubMed Central

    Uygun, Korkut; Tolboom, Herman; Izamis, Maria-Louisa; Uygun, Basak; Sharma, Nripen; Yagi, Hiroshi; Soto-Gutierrez, Alejandro; Hertl, Martin; Berthiaume, François; Yarmush, Martin L.

    2010-01-01

    Donors after Cardiac Death present a significant pool of untapped organs for transplantation, and use of machine perfusion strategies has been an active focus area in experimental transplantation. However, despite two decades of research, a gold standard is yet to emerge for machine perfusion systems and protocols. Whole blood reperfusion has been used as a surrogate for organ transplantation, especially as a model for the short-term response post transplantation, for optimization of perfusion systems. While it is known that there is a strong correlation between liver function in whole-blood reperfusion and survival, the exact nature of these correlations, and to what extent they can be considered as an indicator of viability for transplantation/recipient survival, remain unclear. In this work, we demonstrate that diluted whole-blood reperfusion can be used as a direct model for transplantation of ischemic rat liver grafts. Moreover, it was shown that recipient survival can be predicted based simply on the value of ALT during perfusion, and quantitative criteria of viability was developed for use in this animal model. These results indicate that in the rat model graft survival is highly correlated to hepatocellular damage. PMID:20832525

  11. Radionuclide synovectomy - essentials for rheumatologists.

    PubMed

    Chojnowski, Marek M; Felis-Giemza, Anna; Kobylecka, Małgorzata

    2016-01-01

    Radionuclide synovectomy is a minimally invasive method of treating persistent joint inflammation. It involves intra-articular injection of radioactive colloids which induce necrosis and fibrosis of hypertrophic synovial membrane. The most common indication for radiosynovectomy is rheumatoid arthritis, although patients with seronegative spondyloarthropathies, unclassified arthritis, haemophilic arthropathy and other less common arthropathies can also benefit from this method. Radiosynovectomy is safe, well tolerated and efficacious. About 70-80% of patients respond well to the therapy. However, the therapeutic effects are considerably worse in patients with co-existent osteoarthritis and advanced joint degeneration. Despite its advantages, radionuclide synovectomy is not performed as often as it could be, so greater knowledge and understanding of this method are needed. The authors present the most important facts about radiosynovectomy that may help rheumatologists in their daily clinical practice. PMID:27504020

  12. Molecular Mechanisms of Renal Ischemic Conditioning Strategies.

    PubMed

    Kierulf-Lassen, Casper; Nieuwenhuijs-Moeke, Gertrude J; Krogstrup, Nicoline V; Oltean, Mihai; Jespersen, Bente; Dor, Frank J M F

    2015-01-01

    Ischemia-reperfusion injury is the leading cause of acute kidney injury in a variety of clinical settings such as renal transplantation and hypovolemic and/or septic shock. Strategies to reduce ischemia-reperfusion injury are obviously clinically relevant. Ischemic conditioning is an inherent part of the renal defense mechanism against ischemia and can be triggered by short periods of intermittent ischemia and reperfusion. Understanding the signaling transduction pathways of renal ischemic conditioning can promote further clinical translation and pharmacological advancements in this era. This review summarizes research on the molecular mechanisms underlying both local and remote ischemic pre-, per- and postconditioning of the kidney. The different types of conditioning strategies in the kidney recruit similar powerful pro-survival mechanisms. Likewise, renal ischemic conditioning mobilizes many of the same protective signaling pathways as in other organs, but differences are recognized. PMID:26330099

  13. Novel therapeutic strategies for ischemic heart disease.

    PubMed

    Perricone, Adam J; Vander Heide, Richard S

    2014-11-01

    Despite significant advances in the physician's ability to initiate myocardial reperfusion and salvage heart tissue, ischemic heart disease remains one of the leading causes of death in the United States. Consequently, alternative therapeutic strategies have been intensively investigated, especially methods of enhancing the heart's resistance to ischemic cell death - so called "cardioprotective" interventions. However, although a great deal has been learned regarding the methods and mechanisms of cardioprotective interventions, an efficacious therapy has yet to be successfully implemented in the clinical arena. This review discusses the current understanding of cardioprotection in the context of ischemic heart disease pathophysiology, highlighting those elements of ischemic heart disease pathophysiology that have received less attention as potential targets of cardioprotective intervention.

  14. Histopathologic studies of ischemic optic neuropathy.

    PubMed Central

    Knox, D L; Kerrison, J B; Green, W R

    2000-01-01

    PURPOSE: To define the histopathologic features of eyes in which a pathologic diagnosis of ischemic optic neuropathy had been made in the years 1951 through 1998. METHODS: The following data were documented: age of patient, race, sex, source of tissue, cause of death, clinical history, interval from loss of vision to death, enucleation, exenteration, and biopsy. The histopathologic criteria for diagnosis of ischemic optic neuropathy were the presence of localized ischemic edema, cavernous degeneration, or an area of atrophy located superior or inferior in the optic nerve. Cases with history of abrupt loss of vision were combined with reports from the literature to construct a time table of histopathologic features and associated conditions. RESULTS: Ischemic optic neuropathy was present in 193 eyes. There were 88 females and 65 males. The average age was 71.6 years. Ischemic edema without (early) and with (later) gitter macrophages was present in 26 (13.5%). Cavernous degeneration was present in 69 nerves (36%). Mucopolysaccharide (MPS) was present in 37 cavernous lesions 1 month or longer after loss of vision. Cavernous lesions were seen in 3 eyes in which peripapillary retinal nerve fiber layer hemorrhage had been observed prior to death. Atrophic lesions, the most common pattern, were observed in 133 optic nerves (66.8%). More than 1 ischemic lesion was seen in 38 optic nerves (19.7%). Bilateral ischemic lesions were seen in 50 (35.2%) of 142 paired eyes. CONCLUSIONS: Ischemic optic nerve lesions are initially acellular and later show macrophage infiltration. Cavernous lesions with MPS are present 4 weeks or longer after vision loss. The location of MPS posteriorly and along the internal margin suggests that MPS is produced at the edges of lesions. Progressive vision loss in ischemic optic neuropathy may be secondary to compression of intact nerve from ischemic edema and cavernous swelling, or a second ischemic lesion. Images FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5

  15. Natural chelates for radionuclide decorporation

    DOEpatents

    Premuzic, E.T.

    1983-08-25

    This invention relates to the method and resulting chelates of desorbing a radionuclide selected from thorium, uranium, and plutonium containing cultures in a bioavailable form involving pseudomonas or other microorganisms. A preferred microorganism is Pseudomonas aeruginosa which forms multiple chelates with thorium in the range of molecular weight 1000 to 1000 and also forms chelates with uranium of molecular weight in the area of 100 to 1000 and 1000 to 2000.

  16. Chernobyl radionuclide distribution and migration.

    PubMed

    Izrael, Yury A

    2007-11-01

    The accident at Unit No. 4 of the Chernobyl Nuclear Power Plant on 26 April 1986 presented severe challenges in radiation protection. Early activity measurements defined the contaminated areas in order to determine what persons should be evacuated on the basis of the exposure limit at that time of 100 mSv (10 rem) for accidents. The immediate definition of these areas was accomplished with specially equipped aircraft capable of measuring external gamma-exposure rate and radionuclide spectra. Over time, maps of 137Cs contamination (the most important long-lived radionuclide) have become more and more sophisticated and have been used for further determinations of the control of the consequences of the accident. About 70% of the total release of 137Cs was deposited in Belarus, the Russian Federation, and Ukraine; but there was also widespread deposition throughout the countries of Western Europe. Two atlases of contamination throughout Europe were prepared, and the Russian atlas included data on other radionuclides and on external gamma-exposure rates. The radiocesiums behaved as volatile radionuclides because of the volatility of cesium. In contrast to the typical pattern after nuclear weapons tests, 90Sr behaved only as a refractory element, as its volatile precursors krypton and rubidium had already decayed within the reactor. Nearly all of the refractory elements (strontium, plutonium, etc.) released by the accident were confined to the 30-km zone around the reactor. A proposal is made to develop a more complete atlas of 137Cs deposition from the accident that would include the entire Northern Hemisphere. Water was not an important vector of exposure to human beings following the accident. PMID:18049217

  17. Serial myocardial perfusion imaging: defining a significant change and targeting management decisions.

    PubMed

    Iskandrian, Ami E; Hage, Fadi G; Shaw, Leslee J; Mahmarian, John J; Berman, Daniel S

    2014-01-01

    Myocardial perfusion imaging (MPI) with gated single-photon emission tomography provides important information on the extent and severity of myocardial perfusion abnormalities, including myocardial ischemia. The availability of software for automated quantitative assessment of myocardial perfusion in an objective and more reproducible manner than visual assessment has allowed MPI to be particularly effective in serial evaluation. Serial testing using MPI is widely used in guiding patient care despite the lack of well-defined appropriateness use criteria. This should not be surprising because ischemic heart disease is a life-long malady subject to dynamic changes throughout its natural course and particularly following man-made interventions that may improve or worsen the disease process, such as medical therapy and coronary revascularization. Serial MPI has filled an important clinical gap by providing crucial information for managing patients with changes in clinical presentations or in anticipation of such changes in patients with stable symptoms. In the research arena, serial MPI has been widely applied in randomized controlled trials to study the impact of various medical and interventional therapies on myocardial perfusion, as well as the relative merits of new imaging procedures (hardware and/or software), radiotracers, and stressor agents. Serial testing, however, unlike initial or 1-time testing, has more stringent requirements and is subject to variability because of technical, procedural, interpretational, and biological factors. The intrinsic variability of MPI becomes important in interpreting serial tests in order to define a true change in a given patient and to guide clinical decision making. The purpose of this first comprehensive review on this subject is to illustrate where serial MPI may be useful clinically and in research studies, and to highlight strategies for addressing the various issues that are unique to serial testing in order to derive

  18. [Stunned myocardium after acute ischemic stroke].

    PubMed

    Varela, Daniel; Díaz, Fernanda; Hlavnicka, Alejandro; Wainsztein, Néstor; Leiguarda, Ramón

    2006-01-01

    The so-called stunned myocardium, defined as transitory myocardial contractile dysfunction, has been clearly demonstrated in diverse clinical situations. However, stunned myocardium related to ischemic stroke has been poorly identified. We describe two patients with diagnosis of acute ischemic stroke who developed eletrocardiographic changes, cardiac enzyme increasing levels and myocardial dysfunction secondary to abnormal cardiac wall motion. At the same time the patients developed acute lung injury with rapid resolution, perhaps as a consequence of neurocardiogenic components.

  19. Adiposity and ischemic and hemorrhagic stroke

    PubMed Central

    Kroll, Mary E.; Green, Jane; Beral, Valerie; Sudlow, Cathie L.M.; Brown, Anna; Kirichek, Oksana; Price, Alison; Yang, TienYu Owen

    2016-01-01

    Objective: To compare associations of body mass index (BMI) with ischemic stroke and hemorrhagic stroke risk, and to review the worldwide evidence. Methods: We recruited 1.3 million previously stroke-free UK women between 1996 and 2001 (mean age 57 years [SD 5]) and followed them by record linkage for hospital admissions and deaths. We used Cox regression to estimate adjusted relative risks for ischemic and hemorrhagic (intracerebral or subarachnoid hemorrhage) stroke in relation to BMI. We conducted a meta-analysis of published findings from prospective studies on these associations. Results: During an average follow-up of 11.7 years, there were 20,549 first strokes, of which 9,993 were specified as ischemic and 5,852 as hemorrhagic. Increased BMI was associated with an increased risk of ischemic stroke (relative risk 1.21 per 5 kg/m2 BMI, 95% confidence interval 1.18–1.23, p < 0.0001) but a decreased risk of hemorrhagic stroke (relative risk 0.89 per 5 kg/m2 BMI, 0.86–0.92, p < 0.0001). The BMI-associated trends for ischemic and hemorrhagic stroke were significantly different (heterogeneity: p < 0.0001) but were not significantly different for intracerebral hemorrhage (n = 2,790) and subarachnoid hemorrhage (n = 3,062) (heterogeneity: p = 0.5). Published data from prospective studies showed consistently greater BMI-associated relative risks for ischemic than hemorrhagic stroke with most evidence (prior to this study) coming from Asian populations. Conclusions: In UK women, higher BMI is associated with increased risk of ischemic stroke but decreased risk of hemorrhagic stroke. The totality of the available published evidence suggests that BMI-associated risks are greater for ischemic than for hemorrhagic stroke. PMID:27605176

  20. Chinese Herbal Products for Ischemic Stroke.

    PubMed

    Hung, I-Ling; Hung, Yu-Chiang; Wang, Lin-Yi; Hsu, Sheng-Feng; Chen, Hsuan-Ju; Tseng, Ying-Jung; Kuo, Chun-En; Hu, Wen-Long; Li, Tsai-Chung

    2015-01-01

    Traditional Chinese herbal products (CHPs) have been described in ancient medicine systems as treatments for various stroke-associated ailments. This study is aimed to investigate the prescription patterns and combinations of CHPs for ischemic stroke in Taiwan. Prescriptions of CHPs for ischemic stroke were obtained from the National Health Insurance Research Database (NHIRD) of Taiwan. Every prescription with a leading diagnosis of ischemic stroke made during 2000-2010 was analyzed. Descriptive statistics were applied to the pattern of co-prescriptions. Multiple logistic regression models were used to assess demographic and risk factors that are correlated with CHP use. The dataset of inpatient claims data contained information on 15,896 subjects who experienced ischemic stroke from 2000 to 2010. There was an average of 5.82 CHPs in a single prescription for subjects with ischemic stroke. Bu-yang-huan-wu-tang (BYHWT) (40.32%) was by far the most frequently prescribed formula CHP for ischemic stroke, and the most commonly used combination of two-formula-CHP was BYHWT with Shu-jin-huo-xue-tang (SJHXT) (4.40%). Dan Shen (16.50%) was the most commonly used single CHP for ischemic stroke, and the most commonly used combination of two single CHPs was Shi Chang Pua with Yuan Zhi (4.79%). We found that BYHWT and Dan Shen were the most frequently prescribed formula and single CHP for ischemic stroke, respectively. These results provide information about individualized therapy and may contribute to further pharmacologic experiments and clinical trials. PMID:26477801

  1. Microcirculation Perfusion Monitor on the Back of the Health Volunteers

    PubMed Central

    Li, Yanqi; Li, Xiaomei; Zhou, Dan; Wang, Kang; Liu, Yangyang; Guo, Yi; Qiu, Shuang; Zhai, Tianchen; Liu, Shuang; Liu, Jingjing; Ming, Dong

    2013-01-01

    Objective. To observe the dermal microcirculation blood perfusion characterization of meridians channels (acupoints). Methods. 20 healthy human subjects were monitored using Pericam Perfusion Speckle Imager (PSI) for the changes in dermal microcirculation blood perfusion on governor meridian and other respective dermal regions as a control. Result. The microcirculation blood perfusion on Governor Meridian is higher than its control area. Conclusion. The dermal microcirculation blood perfusion on certain parts of Governor Meridian of healthy human subjects showed specifics. PMID:24371463

  2. Luminal distension as a possible consequence of experimental intestinal perfusion

    PubMed Central

    Wingate, David; Hyams, Ashley; Phillips, Sidney

    1974-01-01

    In an experimental jejunal perfusion study, distress in healthy subjects occurred during eight out of 16 perfusions in which intestinal secretion was provoked. Calculation demonstrates the volumetric consequences of inadequate recovery of secretory perfusates, and analysis of the perfusion studies shows that distress was significantly associated with poor recovery of the perfusate. These observations are pertinent to increasing interest in the phenomenon of intestinal fluid secretion. PMID:4435588

  3. Radionuclide behavior in the environment

    SciTech Connect

    Tveten, U. )

    1991-09-01

    The purpose of this report is to document the results of the following task: Review for quality and consistency the available data on measurements of initial ground contamination of Chernobyl radionuclides in various parts of Norway and subsequent concentrations of these radionuclides in various environmental media as functions of time. Utilize the data obtained to verify the existing models, or to improve them, for describing radionuclide behavior in the environment. Some of the processes standard were: migration into soil; weathering; resuspension; food-chain contamination; and loss or reconcentration by run-off. The task performed within this contract has been to use post-Chernobyl data from Norway to verify or find areas for possible improvement in the chronic exposure pathway models utilized in MACCS. Work has consisted mainly of collecting and evaluating post-Chernobyl information from Norway or other countries when relevant; but has also included experimental work performed specifically for the current task. In most connections the data available show the models and data in MACCS to be appropriate. A few areas where the data indicate that the MACCS approach is faulty or inadequate are, however, pointed out in the report. These should be examined carefully, and appropriate modifications should eventually be made. 14 refs., 12 figs., 22 tabs.

  4. Distribution of lung blood on modified bilateral Glenn shunt evaluated by Tc-99m-MAA lung perfusion scintigraphy: A retrospective study.

    PubMed

    Si, Biao; Luan, Zhao-Sheng; Wang, Tong-Jian; Ning, Yan-Song; Li, Na; Zhu, Meng; Liu, Zhong-Min; Ding, Guang-Hong; Qiao, Bin

    2016-09-01

    The aim of the present study was to determine the distribution of lung blood in a modified bilateral Glenn procedure designed in our institute with lung perfusion scintigraphy. Sixteen consecutive patients who underwent modified bilateral Glenn operation from 2011 to 2014 were enrolled in the study. The control group consisted of 7 patients who underwent bidirectional Glenn shunt. Radionuclide lung perfusion scintigraphy was performed using Tc-99m-macro aggregated albumin (MAA) in all patients. For the patients in modified bilateral Glenn group, the time at which the radioactivity accumulation peaked did not differ significantly between the right and left lung field (t = 0.608, P = 0.554). The incidence of perfusion abnormality in each lung lobe also did not differ significantly (P = 0.426 by Fisher exact test). The radioactive counts were higher in the right lung than in the left lung, but the difference was not statistically significant (t = 1.502, P = 0.157). Radioactive perfusion in the lower lung field was significantly greater than that in the upper field (t = 4.368, P < 0.001). Compared with that in the bidirectional Glenn group, the ratio of radioactivity in the right lung to that in left lung was significantly lower in the modified bilateral Glenn group (t = 3.686, P = 0.002). Lung perfusion scintigraphy confirmed the benefit of the modified bilateral Glenn shunt with regard to more balanced blood perfusion in both lungs. PMID:27661042

  5. Distribution of lung blood on modified bilateral Glenn shunt evaluated by Tc-99m-MAA lung perfusion scintigraphy: A retrospective study.

    PubMed

    Si, Biao; Luan, Zhao-Sheng; Wang, Tong-Jian; Ning, Yan-Song; Li, Na; Zhu, Meng; Liu, Zhong-Min; Ding, Guang-Hong; Qiao, Bin

    2016-09-01

    The aim of the present study was to determine the distribution of lung blood in a modified bilateral Glenn procedure designed in our institute with lung perfusion scintigraphy. Sixteen consecutive patients who underwent modified bilateral Glenn operation from 2011 to 2014 were enrolled in the study. The control group consisted of 7 patients who underwent bidirectional Glenn shunt. Radionuclide lung perfusion scintigraphy was performed using Tc-99m-macro aggregated albumin (MAA) in all patients. For the patients in modified bilateral Glenn group, the time at which the radioactivity accumulation peaked did not differ significantly between the right and left lung field (t = 0.608, P = 0.554). The incidence of perfusion abnormality in each lung lobe also did not differ significantly (P = 0.426 by Fisher exact test). The radioactive counts were higher in the right lung than in the left lung, but the difference was not statistically significant (t = 1.502, P = 0.157). Radioactive perfusion in the lower lung field was significantly greater than that in the upper field (t = 4.368, P < 0.001). Compared with that in the bidirectional Glenn group, the ratio of radioactivity in the right lung to that in left lung was significantly lower in the modified bilateral Glenn group (t = 3.686, P = 0.002). Lung perfusion scintigraphy confirmed the benefit of the modified bilateral Glenn shunt with regard to more balanced blood perfusion in both lungs.

  6. Ex vivo lung perfusion and reconditioning.

    PubMed

    Yeung, Jonathan C; Cypel, Marcelo; Massad, Ehab; Keshavjee, Shaf

    2011-01-01

    Normothermic ex vivo lung perfusion can act as a platform for the evaluation and repair of donor lungs. An acellular hyperosmolar solution is perfused anterograde through the donor lungs at 40% of the estimated cardiac output. Following oxygenation of the perfusate by the lung, it passes through a hollow fiber oxygenator supplied with a hypoxic gas mixture to remove oxygen and to maintain physiological carbon dioxide levels. Flow through a heat exchanger to maintain normothermia and a leukocyte filter to remove demarginated leukocytes completes the circuit. Lung function can be measured by the difference in PO2 between the perfusate postlung and postmembrane and by physiological parameters. Utilization of this method of ex vivo donor lung evaluation should reduce concerns of primary graft dysfunction and increase utilization rates of donor lungs. PMID:24412979

  7. Noninvasive methods of measuring bone blood perfusion

    PubMed Central

    Dyke, J.P.; Aaron, R.K.

    2010-01-01

    Measurement of bone blood flow and perfusion characteristics in a noninvasive and serial manner would be advantageous in assessing revascularization after trauma and the possible risk of avascular necrosis. Many disease states, including osteoporosis, osteoarthritis, and bone neoplasms, result in disturbed bone perfusion. A causal link between bone perfusion and remodeling has shown its importance in sustained healing and regrowth following injury. Measurement of perfusion and permeability within the bone was performed with small and macromolecular contrast media, using dynamic contrast-enhanced magnetic resonance imaging in models of osteoarthritis and the femoral head. Bone blood flow and remodeling was estimated using 18F-Fluoride positron emission tomography in fracture healing and osteoarthritis. Multimodality assessment of bone blood flow, permeability, and remodeling by using noninvasive imaging techniques may provide information essential in monitoring subsequent rates of healing and response to treatment as well as identifying candidates for additional therapeutic or surgical interventions. PMID:20392223

  8. Bubble dynamics in perfused tissue undergoing decompression.

    PubMed

    Meisel, S; Nir, A; Kerem, D

    1981-02-01

    A mathematical model describing bubble dynamics in a perfused tissue undergoing decompression is presented, taking into account physical expansion and inward diffusion from surrounding supersaturated tissue as growth promoting factors and tissue gas elimination by perfusion, tissue elasticity, surface tension and inherent unsaturation as resolving driving forces. The expected behavior after a step reduction of pressure of a bubble initially existing in the tissue, displaying both growth and resolution has been demonstrated. A strong perfusion-dependence of bubble resolution time at low perfusion rates is apparent. The model can account for various exposure pressures and saturation fractions of any inert gas-tissue combination for which a set of physical and physiological parameters is available.

  9. Myocardial ischemic protection in natural mammalian hibernation.

    PubMed

    Yan, Lin; Kudej, Raymond K; Vatner, Dorothy E; Vatner, Stephen F

    2015-03-01

    Hibernating myocardium is an important clinical syndrome protecting the heart with chronic myocardial ischemia, named for its assumed resemblance to hibernating mammals in winter. However, the effects of myocardial ischemic protection have never been studied in true mammalian hibernation, which is a unique strategy for surviving extreme winter environmental stress. The goal of this investigation was to test the hypothesis that ischemic stress may also be protected in woodchucks as they hibernate in winter. Myocardial infarction was induced by coronary occlusion followed by reperfusion in naturally hibernating woodchucks in winter with and without hibernation and in summer, when not hibernating. The ischemic area at risk was similar among groups. Myocardial infarction was significantly less in woodchucks in winter, whether hibernating or not, compared with summer, and was similar to that resulting after ischemic preconditioning. Whereas several genes were up or downregulated in both hibernating woodchuck and with ischemic preconditioning, one mechanism was unique to hibernation, i.e., activation of cAMP-response element binding protein (CREB). When CREB was upregulated in summer, it induced protection similar to that observed in the woodchuck heart in winter. The cardioprotection in hibernation was also mediated by endothelial nitric oxide synthase, rather than inducible nitric oxide synthase. Thus, the hibernating woodchuck heart is a novel model to study cardioprotection for two major reasons: (1) powerful cardioprotection occurs naturally in winter months in the absence of any preconditioning stimuli, and (2) it resembles ischemic preconditioning, but with novel mechanisms, making this model potentially useful for clinical translation.

  10. Myocardial ischemic protection in natural mammalian hibernation.

    PubMed

    Yan, Lin; Kudej, Raymond K; Vatner, Dorothy E; Vatner, Stephen F

    2015-03-01

    Hibernating myocardium is an important clinical syndrome protecting the heart with chronic myocardial ischemia, named for its assumed resemblance to hibernating mammals in winter. However, the effects of myocardial ischemic protection have never been studied in true mammalian hibernation, which is a unique strategy for surviving extreme winter environmental stress. The goal of this investigation was to test the hypothesis that ischemic stress may also be protected in woodchucks as they hibernate in winter. Myocardial infarction was induced by coronary occlusion followed by reperfusion in naturally hibernating woodchucks in winter with and without hibernation and in summer, when not hibernating. The ischemic area at risk was similar among groups. Myocardial infarction was significantly less in woodchucks in winter, whether hibernating or not, compared with summer, and was similar to that resulting after ischemic preconditioning. Whereas several genes were up or downregulated in both hibernating woodchuck and with ischemic preconditioning, one mechanism was unique to hibernation, i.e., activation of cAMP-response element binding protein (CREB). When CREB was upregulated in summer, it induced protection similar to that observed in the woodchuck heart in winter. The cardioprotection in hibernation was also mediated by endothelial nitric oxide synthase, rather than inducible nitric oxide synthase. Thus, the hibernating woodchuck heart is a novel model to study cardioprotection for two major reasons: (1) powerful cardioprotection occurs naturally in winter months in the absence of any preconditioning stimuli, and (2) it resembles ischemic preconditioning, but with novel mechanisms, making this model potentially useful for clinical translation. PMID:25613166

  11. [Ocular ischemic syndrome--a case report].

    PubMed

    Zemba, M; Avram, Corina Ioana; Ochinciuc, Uliana; Stamate, Alina Cristina; Camburu, Raluca Lăcrămioara

    2013-01-01

    Ocular ischemic syndrome, also known as hypoperfusion/ hypotensive retinopathy or as ischemic oculopathy is a rare ocular disease determined by chronic arterial hypoperfusion through central retinal artery, posterior and anterior ciliary arteries. It is bilateral in 20% of the cases. Most often it appears due to severe occlusion of the carotid arteries (ICA, MCA>ECA), described in 1963 by Kearns and Hollenhorst. Occasionally it can be determined by the obstruction of ophtalmic artery or some arterities (Takayasu, giant cell arteritis). The risk factors are: age between 50-80 years, males (M:F = 2:1), arterial hypertension, diabetes, coronary diseases (5% of the cases develop ocular ischemic syndrome), vascular stroke, hemodialysis. The case we present is of an 63 years old man known with primary arterial hypertension, hypercholesterolemia, diabetes type 2 non insulin dependent and diagnosticated with ischemic cerebral stroke and bilateral obstruction of internal carotid arteries in march 2010, who is presenting for visual impairment in both eyes. The imaging investigations show important carotid occlusion and at the ophthalmologic evaluation there are ocular hypertension and rubeosis iridis at the right eye, optic atrophy at both eyes (complete in the right eye and partial in the left eye), with superior altitudinal visual field defect in left eye. The following diagnosis was established: Chronic ocular ischemic syndrome in both eyes with Neovascular glaucoma at the right eye, Anterior ischemic optic neuropathy at the left eye and laser panphotocoagulation at the right eye was started. PMID:24386788

  12. [Ocular ischemic syndrome--a case report].

    PubMed

    Zemba, M; Avram, Corina Ioana; Ochinciuc, Uliana; Stamate, Alina Cristina; Camburu, Raluca Lăcrămioara

    2013-01-01

    Ocular ischemic syndrome, also known as hypoperfusion/ hypotensive retinopathy or as ischemic oculopathy is a rare ocular disease determined by chronic arterial hypoperfusion through central retinal artery, posterior and anterior ciliary arteries. It is bilateral in 20% of the cases. Most often it appears due to severe occlusion of the carotid arteries (ICA, MCA>ECA), described in 1963 by Kearns and Hollenhorst. Occasionally it can be determined by the obstruction of ophtalmic artery or some arterities (Takayasu, giant cell arteritis). The risk factors are: age between 50-80 years, males (M:F = 2:1), arterial hypertension, diabetes, coronary diseases (5% of the cases develop ocular ischemic syndrome), vascular stroke, hemodialysis. The case we present is of an 63 years old man known with primary arterial hypertension, hypercholesterolemia, diabetes type 2 non insulin dependent and diagnosticated with ischemic cerebral stroke and bilateral obstruction of internal carotid arteries in march 2010, who is presenting for visual impairment in both eyes. The imaging investigations show important carotid occlusion and at the ophthalmologic evaluation there are ocular hypertension and rubeosis iridis at the right eye, optic atrophy at both eyes (complete in the right eye and partial in the left eye), with superior altitudinal visual field defect in left eye. The following diagnosis was established: Chronic ocular ischemic syndrome in both eyes with Neovascular glaucoma at the right eye, Anterior ischemic optic neuropathy at the left eye and laser panphotocoagulation at the right eye was started.

  13. The direct incorporation of perfusion defect information to define ischemia and infarction in a finite element model of the left ventricle.

    PubMed

    Veress, Alexander I; Fung, George S K; Lee, Taek-Soo; Tsui, Benjamin M W; Kicska, Gregory A; Paul Segars, W; Gullberg, Grant T

    2015-05-01

    This paper describes the process in which complex lesion geometries (specified by computer generated perfusion defects) are incorporated in the description of nonlinear finite element (FE) mechanical models used for specifying the motion of the left ventricle (LV) in the 4D extended cardiac torso (XCAT) phantom to simulate gated cardiac image data. An image interrogation process was developed to define the elements in the LV mesh as ischemic or infarcted based upon the values of sampled intensity levels of the perfusion maps. The intensity values were determined for each of the interior integration points of every element of the FE mesh. The average element intensity levels were then determined. The elements with average intensity values below a user-controlled threshold were defined as ischemic or infarcted depending upon the model being defined. For the infarction model cases, the thresholding and interrogation process were repeated in order to define a border zone (BZ) surrounding the infarction. This methodology was evaluated using perfusion maps created by the perfusion cardiac-torso (PCAT) phantom an extension of the 4D XCAT phantom. The PCAT was used to create 3D perfusion maps representing 90% occlusions at four locations (left anterior descending (LAD) segments 6 and 9, left circumflex (LCX) segment 11, right coronary artery (RCA) segment 1) in the coronary tree. The volumes and shapes of the defects defined in the FE mechanical models were compared with perfusion maps produced by the PCAT. The models were incorporated into the XCAT phantom. The ischemia models had reduced stroke volume (SV) by 18-59 ml. and ejection fraction (EF) values by 14-50% points compared to the normal models. The infarction models, had less reductions in SV and EF, 17-54 ml. and 14-45% points, respectively. The volumes of the ischemic/infarcted regions of the models were nearly identical to those volumes obtained from the perfusion images and were highly correlated (R

  14. Vicarious Audiovisual Learning in Perfusion Education

    PubMed Central

    Rath, Thomas E.; Holt, David W.

    2010-01-01

    Abstract: 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 standalone 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 < .05). The same was true for test #2 where video learners (n = 10) had an average score of 77% while text learners (n = 9) scored 60% (p < .05). Survey results indicated video learners were more satisfied with their learning module than text learners. Vicarious 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

  15. Pancreas transplants: Evaluation using perfusion scintigraphy

    SciTech Connect

    Kuni, C.C.; du Cret, R.P.; Boudreau, R.J.

    1989-07-01

    To determine the value of scintigraphic perfusion studies in evaluating pancreas transplant patients, we reviewed 56 of these studies in 22 patients who had 27 transplants. Seventeen patients underwent two or more studies. The perfusion studies were performed with 20 mCi (740 MBq) of 99mTc-DTPA injected as a bolus followed by eight to 16 serial 2-sec images and a 500,000-count immediate static image. Images were evaluated for (1) the time and intensity of pancreatic peak radioactivity relative to the time and intensity of the iliac arterial peak; (2) relative pancreatic to iliac arterial intensity on the static image; and (3) size, homogeneity, and definition of the pancreas. Clinical diagnoses at the time of scintigraphy of normal function (n = 36), rejection (n = 13), pancreatitis (n = 6), or arterial thrombosis (n = 1) were based on insulin requirement, urine amylase, serum glucose, serum amylase, response to therapy, cultures, CT, MR, sonography, scintigraphy with 67Ga or 111In-WBCs, percutaneous drainage results, angiography, surgery, and pathologic examination of resected transplants. Three 99mTc-DTPA perfusion studies showed no pancreatic perfusion, four showed decreasing perfusion on serial studies, and five showed progressive loss of definition of the pancreas on serial studies. Of the three patients with no detectable perfusion, one had a normally functioning transplant, one had arterial thrombosis with transplant infarction, and one had severe rejection with minimal function. Decreasing perfusion was associated with rejection in three patients and pancreatitis in one. Decreasing definition was seen in four patients with rejection and one with pancreatitis. We conclude that perfusion scintigraphy is useful, primarily when performed serially, although nonspecific for evaluating pancreas transplants.

  16. Improved exercise myocardial perfusion during lidoflazine therapy

    SciTech Connect

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

    1983-11-01

    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.

  17. Radionuclide daughter inventory generator code: DIG

    SciTech Connect

    Fields, D.E.; Sharp, R.D.

    1985-09-01

    The Daughter Inventory Generator (DIG) code accepts a tabulation of radionuclide initially present in a waste stream, specified as amounts present either by mass or by activity, and produces a tabulation of radionuclides present after a user-specified elapsed time. This resultant radionuclide inventory characterizes wastes that have undergone daughter ingrowth during subsequent processes, such as leaching and transport, and includes daughter radionuclides that should be considered in these subsequent processes or for inclusion in a pollutant source term. Output of the DIG code also summarizes radionuclide decay constants. The DIG code was developed specifically to assist the user of the PRESTO-II methodology and code in preparing data sets and accounting for possible daughter ingrowth in wastes buried in shallow-land disposal areas. The DIG code is also useful in preparing data sets for the PRESTO-EPA code. Daughter ingrowth in buried radionuclides and in radionuclides that have been leached from the wastes and are undergoing hydrologic transport are considered, and the quantities of daughter radionuclide are calculated. Radionuclide decay constants generated by DIG and included in the DIG output are required in the PRESTO-II code input data set. The DIG accesses some subroutines written for use with the CRRIS system and accesses files containing radionuclide data compiled by D.C. Kocher. 11 refs.

  18. Perfusion visualization and analysis for pulmonary embolism

    NASA Astrophysics Data System (ADS)

    Vaz, Michael S.; Kiraly, Atilla P.; Naidich, David P.; Novak, Carol L.

    2005-04-01

    Given the nature of pulmonary embolism (PE), timely and accurate diagnosis is critical. Contrast enhanced high-resolution CT images allow physicians to accurately identify segmental and sub-segmental emboli. However, it is also important to assess the effect of such emboli on the blood flow in the lungs. Expanding upon previous research, we propose a method for 3D visualization of lung perfusion. The proposed method allows users to examine perfusion throughout the entire lung volume at a single glance, with areas of diminished perfusion highlighted so that they are visible independent of the viewing location. This may be particularly valuable for better accuracy in assessing the extent of hemodynamic alterations resulting from pulmonary emboli. The method also facilitates user interaction and may help identify small peripheral sub-segmental emboli otherwise overlooked. 19 patients referred for possible PE were evaluated by CT following the administration of IV contrast media. An experienced thoracic radiologist assessed the 19 datasets with 17 diagnosed as being positive for PE with multiple emboli. Since anomalies in lung perfusion due to PE can alter the distribution of parenchymal densities, we analyzed features collected from histograms of the computed perfusion maps and demonstrate their potential usefulness as a preliminary test to suggest the presence of PE. These histogram features also offer the possibility of distinguishing distinct patterns associated with chronic PE and may even be useful for further characterization of changes in perfusion or overall density resulting from associated conditions such as pneumonia or diffuse lung disease.

  19. Effect of beam hardening on transmural myocardial perfusion quantification in myocardial CT imaging

    NASA Astrophysics Data System (ADS)

    Fahmi, Rachid; Eck, Brendan L.; Levi, Jacob; Fares, Anas; Wu, Hao; Vembar, Mani; Dhanantwari, Amar; Bezerra, Hiram G.; Wilson, David L.

    2016-03-01

    The detection of subendocardial ischemia exhibiting an abnormal transmural perfusion gradient (TPG) may help identify ischemic conditions due to micro-vascular dysfunction. We evaluated the effect of beam hardening (BH) artifacts on TPG quantification using myocardial CT perfusion (CTP). We used a prototype spectral detector CT scanner (Philips Healthcare) to acquire dynamic myocardial CTP scans in a porcine ischemia model with partial occlusion of the left anterior descending (LAD) coronary artery guided by pressure wire-derived fractional flow reserve (FFR) measurements. Conventional 120 kVp and 70 keV projection-based mono-energetic images were reconstructed from the same projection data and used to compute myocardial blood flow (MBF) using the Johnson-Wilson model. Under moderate LAD occlusion (FFR~0.7), we used three 5 mm short axis slices and divided the myocardium into three LAD segments and three remote segments. For each slice and each segment, we characterized TPG as the mean "endo-to-epi" transmural flow ratio (TFR). BH-induced hypoenhancement on the ischemic anterior wall at 120 kVp resulted in significantly lower mean TFR value as compared to the 70 keV TFR value (0.29+/-0.01 vs. 0.55+/-0.01 p<1e-05). No significant difference was measured between 120 kVp and 70 keV mean TFR values on segments moderately affected or unaffected by BH. In the entire ischemic LAD territory, 120 kVp mean endocardial flow was significantly reduced as compared to mean epicardial flow (15.80+/-10.98 vs. 40.85+/-23.44 ml/min/100g; p<1e-04). At 70 keV, BH was effectively minimized resulting in mean endocardial MBF of 40.85+/-15.3407 ml/min/100g vs. 74.09+/-5.07 ml/min/100g (p=0.0054) in the epicardium. We also found that BH artifact in the conventional 120 kVp images resulted in falsely reduced MBF measurements even under non-ischemic conditions.

  20. Methods of separating short half-life radionuclides from a mixture of radionuclides

    DOEpatents

    Bray, L.A.; Ryan, J.L.

    1998-09-15

    The present invention is a method of obtaining a radionuclide product selected from the group consisting of {sup 223}Ra and {sup 225}Ac, from a radionuclide ``cow`` of {sup 227}Ac or {sup 229}Th respectively. The method comprises the steps of (a) permitting ingrowth of at least one radionuclide daughter from said radionuclide ``cow`` forming an ingrown mixture; (b) insuring that the ingrown mixture is a nitric acid ingrown mixture; (c) passing the nitric acid ingrown mixture through a first nitrate form ion exchange column which permits separating the ``cow`` from at least one radionuclide daughter; (d) insuring that the at least one radionuclide daughter contains the radionuclide product; (e) passing the at least one radionuclide daughter through a second ion exchange column and separating the at least one radionuclide daughter from the radionuclide product and (f) recycling the at least one radionuclide daughter by adding it to the ``cow``. In one embodiment the radionuclide ``cow`` is the {sup 227}Ac, the at least one daughter radionuclide is a {sup 227}Th and the product radionuclide is the {sup 223}Ra and the first nitrate form ion exchange column passes the {sup 227}Ac and retains the {sup 227}Th. In another embodiment the radionuclide ``cow`` is the {sup 229}Th, the at least one daughter radionuclide is a {sup 225}Ra and said product radionuclide is the {sup 225}Ac and the {sup 225}Ac and nitrate form ion exchange column retains the {sup 229}Th and passes the {sup 225}Ra/Ac. 8 figs.

  1. Methods of separating short half-life radionuclides from a mixture of radionuclides

    DOEpatents

    Bray, Lane A.; Ryan, Jack L.

    1998-01-01

    The present invention is a method of obtaining a radionuclide product selected from the group consisting of .sup.223 Ra and .sup.225 Ac, from a radionuclide "cow" of .sup.227 Ac or .sup.229 Th respectively. The method comprises the steps of a) permitting ingrowth of at least one radionuclide daughter from said radionuclide "cow" forming an ingrown mixture; b) insuring that the ingrown mixture is a nitric acid ingrown mixture; c) passing the nitric acid ingrown mixture through a first nitrate form ion exchange column which permits separating the "cow" from at least one radionuclide daughter; d) insuring that the at least one radionuclide daughter contains the radionuclide product; e) passing the at least one radionuclide daughter through a second ion exchange column and separating the at least one radionuclide daughter from the radionuclide product and f) recycling the at least one radionuclide daughter by adding it to the "cow". In one embodiment the radionuclide "cow" is the .sup.227 Ac, the at least one daughter radionuclide is a .sup.227 Th and the product radionuclide is the .sup.223 Ra and the first nitrate form ion exchange column passes the .sup.227 Ac and retains the .sup.227 Th. In another embodiment the radionuclide "cow"is the .sup.229 Th, the at least one daughter radionuclide is a .sup.225 Ra and said product radionuclide is the .sup.225 Ac and the .sup.225 Ac and nitrate form ion exchange column retains the .sup.229 Th and passes the .sup.225 Ra/Ac.

  2. Technical aspects of MR perfusion.

    PubMed

    Sourbron, Steven

    2010-12-01

    The most common methods for measuring perfusion with MRI are arterial spin labelling (ASL), dynamic susceptibility contrast (DSC-MRI), and T(1)-weighted dynamic contrast enhancement (DCE-MRI). This review focuses on the latter approach, which is by far the most common in the body and produces measures of capillary permeability as well. The aim is to present a concise but complete overview of the technical issues involved in DCE-MRI data acquisition and analysis. For details the reader is referred to the references. The presentation of the topic is essentially generic and focuses on technical aspects that are common to all DCE-MRI measurements. For organ-specific problems and illustrations, we refer to the other papers in this issue. In Section 1 "Theory" the basic quantities are defined, and the physical mechanisms are presented that provide a relation between the hemodynamic parameters and the DCE-MRI signal. Section 2 "Data acquisition" discusses the issues involved in the design of an optimal measurement protocol. Section 3 "Data analysis" summarizes the steps that need to be taken to determine the hemodynamic parameters from the measured data. PMID:20363574

  3. Myocardial apoptosis and injury of donor hearts kept in completely beating status with normothermic blood perfusion for transplants

    PubMed Central

    Kuang, Jun; Sun, Yanpeng; Wang, Wei; Ke, Han; Ye, Hong

    2015-01-01

    Objective: Normothermic blood perfusion is the developing trend of donor heart preservation. Theoretically, donor hearts preserved in a beating status may be the perfect method to reduce time-dependent ischemic injury, resuscitate marginal hearts expanding the donor pool and potentially improve the function of isolated hearts. In this study, to investigate the protective effect of normothermic blood perfusion, we maintained the donor hearts in a beating status and compared the changes of myocardial apoptosis and injury with standard hypothermic and static storage. Methods: Thirty rat hearts were preserved in static cold storage (Group A, n=10, stored in 4°C histidine-tryptophan-ketoglutarate solution), or in static normothermic blood perfusion (Group B, n=10, perfused with normothermic blood) or in beating status (Group C, n=10, perfused continuously with normothermic blood) for 9 hours. Myocardial injury markers including creatine kinase-MB (CK-MB) and cardiac troponin I (cTnI), myocardial metabolic rate related indicators including Methane Dicarboxylic Aldehyde (MDA) and Adenosine Triphosphate (ATP) were investigated before and after preservation. And also TUNEL staining and mRNA and protein expression of apoptosis markers such as Bax, Bcl-2, Caspase-3 and Cleaved Caspase-3 were used to evaluated the degree of myocardial apoptosis. Results: It is found that the levels of CK-MB and cTnI in Group C were significantly lower than those of Group A and Group B (P<0.05). However, there was no significant statistical difference of ATP content among three groups. When compared with Group A and B, the quality of MDA in Group C was obviously lower. In addition, it showed that a remarkable reduction in TUNEL-positive nuclear staining in Group C but higher in other two groups. And inhibited apoptosis was also confirmed by the results of mRNA and protein expression of apoptosis markers including Bax and Bcl-2. Conclusions: It is an effective and appropriate approach to

  4. Microbial Transformations of Actinides and Other Radionuclides

    SciTech Connect

    Francis,A.J.; Dodge, C. J.

    2009-01-07

    Microorganisms can affect the stability and mobility of the actinides and other radionuclides released from nuclear fuel cycle and from nuclear fuel reprocessing plants. Under appropriate conditions, microorganisms can alter the chemical speciation, solubility and sorption properties and thus could increase or decrease the concentrations of radionuclides in solution in the environment and the bioavailability. Dissolution or immobilization of radionuclides is brought about by direct enzymatic action or indirect non-enzymatic action of microorganisms. Although the physical, chemical, and geochemical processes affecting dissolution, precipitation, and mobilization of radionuclides have been extensively investigated, we have only limited information on the effects of microbial processes and biochemical mechanisms which affect the stability and mobility of radionuclides. The mechanisms of microbial transformations of the major and minor actinides U, Pu, Cm, Am, Np, the fission products and other radionuclides such as Ra, Tc, I, Cs, Sr, under aerobic and anaerobic conditions in the presence of electron donors and acceptors are reviewed.

  5. Targeted Radionuclide Therapy of Human Tumors

    PubMed Central

    Gudkov, Sergey V.; Shilyagina, Natalya Yu.; Vodeneev, Vladimir A.; Zvyagin, Andrei V.

    2015-01-01

    Targeted radionuclide therapy is one of the most intensively developing directions of nuclear medicine. Unlike conventional external beam therapy, the targeted radionuclide therapy causes less collateral damage to normal tissues and allows targeted drug delivery to a clinically diagnosed neoplastic malformations, as well as metastasized cells and cellular clusters, thus providing systemic therapy of cancer. The methods of targeted radionuclide therapy are based on the use of molecular carriers of radionuclides with high affinity to antigens on the surface of tumor cells. The potential of targeted radionuclide therapy has markedly grown nowadays due to the expanded knowledge base in cancer biology, bioengineering, and radiochemistry. In this review, progress in the radionuclide therapy of hematological malignancies and approaches for treatment of solid tumors is addressed. PMID:26729091

  6. Targeted Radionuclide Therapy of Human Tumors.

    PubMed

    Gudkov, Sergey V; Shilyagina, Natalya Yu; Vodeneev, Vladimir A; Zvyagin, Andrei V

    2015-12-28

    Targeted radionuclide therapy is one of the most intensively developing directions of nuclear medicine. Unlike conventional external beam therapy, the targeted radionuclide therapy causes less collateral damage to normal tissues and allows targeted drug delivery to a clinically diagnosed neoplastic malformations, as well as metastasized cells and cellular clusters, thus providing systemic therapy of cancer. The methods of targeted radionuclide therapy are based on the use of molecular carriers of radionuclides with high affinity to antigens on the surface of tumor cells. The potential of targeted radionuclide therapy has markedly grown nowadays due to the expanded knowledge base in cancer biology, bioengineering, and radiochemistry. In this review, progress in the radionuclide therapy of hematological malignancies and approaches for treatment of solid tumors is addressed.

  7. Chemical speciation of radionuclides migrating in groundwaters

    SciTech Connect

    Robertson, D.; Schilk, A.; Abel, K.; Lepel, E.; Thomas, C.; Pratt, S.; Cooper, E.; Hartwig, P.; Killey, R.

    1994-04-01

    In order to more accurately predict the rates and mechanisms of radionuclide migration from low-level waste disposal facilities via groundwater transport, ongoing studies are being conducted at field sites at Chalk River Laboratories to identify and characterize the chemical speciation of mobile, long-lived radionuclides migrating in groundwaters. Large-volume water sampling techniques are being utilized to separate and concentrate radionuclides into particular, cationic, anionic, and nonionic chemical forms. Most radionuclides are migrating as soluble, anionic species that appear to be predominantly organoradionuclide complexes. Laboratory studies utilizing anion exchange chromatography have separated several anionically complexed radionuclides, e.g., {sup 60}Co and {sup 106}Ru, into a number of specific compounds or groups of compounds. Further identification of the anionic organoradionuclide complexes is planned utilizing high resolution mass spectrometry. Large-volume ultra-filtration experiments are characterizing the particulate forms of radionuclides being transported in these groundwaters.

  8. Colloid labelled with radionuclide and method

    DOEpatents

    Atcher, R.W.; Hines, J.J.

    1990-11-13

    A ferric hydroxide colloid having an alpha-emitting radionuclide essentially on the outer surfaces and a method of forming same. The method includes oxidizing a ferrous hydroxide to ferric hydroxide in the presence of a preselected radionuclide to form a colloid having the radionuclide on the outer surface thereof, and thereafter washing the colloid, and suspending the washed colloid in a suitable solution. The labelled colloid is useful in cancer therapy and for the treatment of inflamed joints. No Drawings

  9. Colloid labelled with radionuclide and method

    DOEpatents

    Atcher, Robert W.; Hines, John J.

    1990-01-01

    A ferric hydroxide colloid having an alpha-emitting radionuclide essentially on the outer surfaces and a method of forming same. The method includes oxidizing a ferrous hydroxide to ferric hydroxide in the presence of a preselected radionuclide to form a colloid having the radionuclide on the outer surface thereof, and thereafter washing the colloid, and suspending the washed colloid in a suitable solution. The labelled colloid is useful in cancer therapy and for the treatment of inflamed joints.

  10. Method of making colloid labeled with radionuclide

    DOEpatents

    Atcher, Robert W.; Hines, John J.

    1991-01-01

    A ferric hydroxide colloid having an alpha-emitting radionuclide essentially on the outer surfaces and a method of forming same. The method includes oxidizing a ferrous hydroxide to ferric hydroxide in the presence of a preselected radionuclide to form a colloid having the radionuclide on the outer surface thereof, and thereafter washing the colloid, and suspending the washed colloid in a suitable solution. The labelled colloid is useful in cancer therapy and for the treatment of inflamed joints.

  11. Effects of Steroid Hormones on Sex Differences in Cerebral Perfusion.

    PubMed

    Ghisleni, Carmen; Bollmann, Steffen; Biason-Lauber, Anna; Poil, Simon-Shlomo; Brandeis, Daniel; Martin, Ernst; Michels, Lars; Hersberger, Martin; Suckling, John; Klaver, Peter; O'Gorman, Ruth L

    2015-01-01

    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.

  12. Radionuclide renography predicts functional changes in patients with renal artery involvement by Takayasu's arteritis

    SciTech Connect

    Cuocolo, A.; McCarthy, K.E.; Sandrock, D.; Miller, D.L.; Neumann, R.D. )

    1989-01-01

    Renovascular hypertension is a major complication of Takayasu's arteritis, which contributes to the high mortality associated with the disease. We studied 5 patients affected by different degrees of Takayasu's arteritis to assess the usefulness of radionuclide renography in evaluating renal perfusion and function, and to predict changes induced by the disease before and after therapeutic interventions. Computer-assisted dynamic renal imaging with Tc-99m diethylenetriaminepentaacetic acid (DPTA) and I-131 orthoiodohippurate (OIH), and renal arteriography were concurrently performed in all patients. Two patients with hemodynamically insignificant renal artery stenosis showed normal perfusion and function by renography. Three patients had significant renal artery stenosis and functional changes on renography. Subsequently, two of these patients had successful therapy (one had bilateral renal artery bypass grafts, and the other had renal artery angioplasty), and both showed functional improvement at renography. Our results demonstrate that radionuclide renography is valuable in the assessment of functional changes induced by Takayasu's arteritis as well as for determining the response to therapeutic interventions.

  13. Ion binding compounds, radionuclide complexes, methods of making radionuclide complexes, methods of extracting radionuclides, and methods of delivering radionuclides to target locations

    DOEpatents

    Chen, Xiaoyuan; Wai, Chien M.; Fisher, Darrell R.

    2000-01-01

    The invention pertains to compounds for binding lanthanide ions and actinide ions. The invention further pertains to compounds for binding radionuclides, and to methods of making radionuclide complexes. Also, the invention pertains to methods of extracting radionuclides. Additionally, the invention pertains to methods of delivering radionuclides to target locations. In one aspect, the invention includes a compound comprising: a) a calix[n]arene group, wherein n is an integer greater than 3, the calix[n]arene group comprising an upper rim and a lower rim; b) at least one ionizable group attached to the lower rim; and c) an ion selected from the group consisting of lanthanide and actinide elements bound to the ionizable group. In another aspect, the invention includes a method of extracting a radionuclide, comprising: a) providing a sample comprising a radionuclide; b) providing a calix[n]arene compound in contact with the sample, wherein n is an integer greater than 3; and c) extracting radionuclide from the sample into the calix[n]arene compound. In yet another aspect, the invention includes a method of delivering a radionuclide to a target location, comprising: a) providing a calix[n]arene compound, wherein n is an integer greater than 3, the calix[n]arene compound comprising at least one ionizable group; b) providing a radionuclide bound to the calix[n]arene compound; and c) providing an antibody attached to the calix[n]arene compound, the antibody being specific for a material found at the target location.

  14. Therapy for incorporated radionuclides: scope and need

    SciTech Connect

    Smith, V.H.

    1981-03-01

    In the United States the recent termination of funding for research on therapy for incorporated radionuclides has virtually halted progress on improved or new agents and procedures for removing radioactivity from the body. Research was eliminated, but is still needed on new removal agents, improved delivery system, in vitro test systems, and the toxicology of treatments. For many radionuclides, no adequate therapy exists. The relationship between radionuclide removal and reduction in cancer risk is still unanswered. Without proper research support, needed improvements in the treatment for incorporated radionuclides in the US are uncertain.

  15. Early Recovery of Regional Performance in Salvaged Ischemic Myocardium following Coronary Artery Occlusion in the Dog

    PubMed Central

    Darsee, John R.; Kloner, Robert A.; Braunwald, Eugene

    1981-01-01

    Although numerous agents have been shown experimentally to protect ischemic myocardium, a critical unanswered question is whether function is preserved in the salvaged tissue. Accordingly, 38 openchest dogs had measurements of percent segment length shortening (%SS) and velocity of segment length shortening either in midmyocardial or subepicardial and subendocardial ischemic segments before and after 60 min of left anterior descending coronary artery occlusion during 5 h of reperfusion; 10 additional dogs were subjected to 3 h of coronary occlusion followed by 72 h of reperfusion. 15 min after coronary artery occlusion, radiolabeled microspheres were injected into the left atrium for measurement of regional myocardial blood flow, and dogs were treated with 1 mg/kg i.v. (n = 23) of an anti-inflammatory drug, flurbiprofen or an equal volume of saline (n = 25). The ischemic myocardium-at-risk for necrosis was determined by injecting methylene blue dye into the left atrium with the coronary artery reoccluded at the end of the reperfusion period, slicing the left ventricle into thin transverse sections, and measuring the areas of each slice that were not perfused (pink unstained tissue) by methylene blue. The quantity of necrotic tissue in each transverse section was measured by planimetry after incubation of the slices in triphenyltetrazolium chloride, and by direct histological examination in dogs with 72 h of reperfusion. Regional myocardial blood flow of the ischemic segments between the ultrasonic dimension crystals was similar in treated (0.34±0.03 ml/min per g) and control dogs (0.35±0.03 ml/min per g). In saline-treated control dogs subjected to a l-h coronary occlusion, 17.9±1.8% of the myocardium-at-risk became necrotic but in flurbiprofen-treated dogs none of the tissue became necrotic. In saline-treated dogs passive lengthening of the previously ischemic segments persisted through 5 h of reperfusion in all three regions of myocardium after a 1-h coronary

  16. Acute gangrenous cholecystitis: radionuclide diagnosis

    SciTech Connect

    Brachman, M.B.; Tanasescu, D.E.; Ramanna, L.; Waxman, A.D.

    1984-04-01

    Radionuclide hepatobiliary imaging with Tc-99m IDA is a useful procedure for the diagnosis of acute cholecystitis. Visualization of the gallbladder essentially rules out acute cholecystitis. Nonvisualization suggest acute cholecystitis but may also be associated with chronic gallbladder disease or other conditions. The authors recently observed five patients in whom a rim of increased parenchymal liver activity was seen adjacent to the gallbladder fossa. All five patients had acute gangrenous cholecystitis. The rim of increased activity appears to be a useful secondary sign of acute cholecystitis.

  17. Treatment of infrapopliteal critical limb ischemia in 2013: the wound perfusion approach.

    PubMed

    Bunte, Matthew C; Shishehbor, Mehdi H

    2013-06-01

    The primary goals of treatment for critical limb ischemia (CLI) are alleviation of ischemic rest pain, healing of arterial insufficiency ulcers, and improving quality of life. These goals are directed toward preventing limb loss and CLI-related mortality. Arterial revascularization serves as the foundation of a contemporary approach to promote amputation-free survival. Mounting evidence supports a wound-directed angiosome revascularization approach, increasingly achieved with endovascular techniques. Innovations in technology and wound-perfusion strategy have advanced patient care and are accelerating the pace of CLI treatment. The evolving angiosome revascularization approach has been augmented with a multidisciplinary wound care strategy that deserves particular emphasis. These state-of-the-art advances in CLI management are reported herein with considerations for the future treatment of CLI.

  18. Regulation of coronary blood flow in health and ischemic heart disease.

    PubMed

    Duncker, Dirk J; Koller, Akos; Merkus, Daphne; Canty, John M

    2015-01-01

    The major factors determining myocardial perfusion and oxygen delivery have been elucidated over the past several decades, and this knowledge has been incorporated into the management of patients with ischemic heart disease (IHD). The basic understanding of the fluid mechanical behavior of coronary stenoses has also been translated to the cardiac catheterization laboratory where measurements of coronary pressure distal to a stenosis and coronary flow are routinely obtained. However, the role of perturbations in coronary microvascular structure and function, due to myocardial hypertrophy or coronary microvascular dysfunction, in IHD is becoming increasingly recognized. Future studies should therefore be aimed at further improving our understanding of the integrated coronary microvascular mechanisms that control coronary blood flow, and of the underlying causes and mechanisms of coronary microvascular dysfunction. This knowledge will be essential to further improve the treatment of patients with IHD.

  19. Cardiac MRI and Ischemic Heart Disease: Role in Diagnosis and Risk Stratification.

    PubMed

    Sawlani, Rahul N; Collins, Jeremy D

    2016-05-01

    Cardiac magnetic resonance imaging (CMRI) has been under development for the past four decades and has more recently become an essential tool in the evaluation of ischemic heart disease (IHD). It is the reference standard for quantification of both right and left ventricular volume and function and, after landmark work published in the New England Journal of Medicine in 2000, has proven effective in identifying hibernating myocardium, or hypokinetic myocardium that will recover after revascularization. More recent literature continues to support both delayed enhancement imaging and CMRI stress perfusion as essential tools in evaluating IHD. This review will briefly address the basics of CMRI and the scientific literature supporting the use of CMRI in IHD. It will then address more recent clinical studies establishing the clinical utility of CMRI in IHD, followed by a discussion of future directions in CMRI. PMID:26980317

  20. Effects of isoproterenol on the metabolism of normal and ischemic heart.

    PubMed

    Andrieu, J L; Vial, C; Font, B; Goldschmidt, D; Ollagnier, M; Faucon, G

    1980-04-01

    A study has been made of the simultaneous evolution of cardiac activity and metabolism in the dog heart in situ, during the perfusion of isoproterenol in a dose comparable to therapeutic doses (1 micrograms x kg-1 x min-1, 30 min). A total cardiopulmonary by-pass system allowed of taking the repeated myocardial tissue samples necessary for the determination of the main energetic substrate and high-energy phosphate content. Samples were taken from subendocardial and subepicardial layers separately. The acceleration of heart rate due to isoproterenol was quickly regressive but, in the well-irrigated heart, the drug elicited a rapid fall in glycogen content and a considerable rise in lactate content, a slower reduction in free fatty acid concentration restricted to the subendocardial layer, and no significant variation of creatine phosphate or ATP. In the ischemic heart, isoproterenol aggravated the glycolysis disturbances without completely losing its effects on lipolysis when the ischemia was not too marked.

  1. Clusterin: a protective mediator for ischemic cardiomyocytes?

    PubMed

    Krijnen, P A J; Cillessen, S A G M; Manoe, R; Muller, A; Visser, C A; Meijer, C J L M; Musters, R J P; Hack, C E; Aarden, L A; Niessen, H W M

    2005-11-01

    We examined the relationship between clusterin and activated complement in human heart infarction and evaluated the effect of this protein on ischemic rat neonatal cardiomyoblasts (H9c2) and isolated adult ventricular rat cardiomyocytes as in vitro models of acute myocardial infarction. Clusterin protects cells by inhibiting complement and colocalizes with complement on jeopardized human cardiomyocytes after infarction. The distribution of clusterin and complement factor C3d was evaluated in the infarcted human heart. We also analyzed the protein expression of clusterin in ischemic H9c2 cells. The binding of endogenous and purified human clusterin on H9c2 cells was analyzed by flow cytometry. Furthermore, the effect of clusterin on the viability of ischemically challenged H9c2 cells and isolated adult ventricular rat cardiomyocytes was analyzed. In human myocardial infarcts, clusterin was found on scattered, morphologically viable cardiomyocytes within the infarcted area that were negative for complement. In H9c2 cells, clusterin was rapidly expressed after ischemia. Its expression was reduced after reperfusion. Clusterin bound to single annexin V-positive or annexin V and propidium iodide-positive H9c2 cells. Clusterin inhibited ischemia-induced death in H9c2 cells as well as in isolated adult ventricular rat cardiomyocytes in the absence of complement. We conclude that ischemia induces the upregulation of clusterin in ischemically challenged, but viable, cardiomyocytes. Our data suggest that clusterin protects cardiomyocytes against ischemic cell death via a complement-independent pathway.

  2. [Experimental model of ocular ischemic diseases].

    PubMed

    Kiseleva, T N; Chudin, A V

    2014-01-01

    The review presents the most common methods of modeling of retinal ischemia in vitro (chemical ischemia with iodoacetic acid, incubation of the retinal pigment epithelium cells with oligomycin, deprivation of oxygen and glucose) and in vivo (a model with increased intraocular pressure, cerebral artery occlusion, chronic ligation of the carotid arteries, photocoagulation of the retinal vessels, occlusion of the central retinal artery, endothelin-1 administration). Modeling ischemic injury in rats is the most frequently used method in studies, because the blood supply of their eyes is similar to blood flow in the human eyes. Each method has its own advantages and disadvantages. Application of methods depends on the purpose of the experimental study. Currently model of ocular ischemic disease can be obtained easily by injecting vasoconstrictive drug endothelin-1. It is the most widely used method of high intraocular pressure induced ocular ischemic damage similar to glaucoma, occlusion of central retinal artery or ophthalmic artery in human. The development of experimental models of ocular ischemic diseases and detailed investigation of mechanisms of impairment of microcirculation are useful for improve the efficiency of diagnostic and treatment of ischemic diseases of retina and optic nerve. PMID:25971134

  3. Hypothermia for hypoxic–ischemic encephalopathy

    PubMed Central

    Cotten, C Michael; Shankaran, Seetha

    2010-01-01

    Moderate to severe hypoxic–ischemic injury in newborn infants, manifested as encephalopathy immediately or within hours after birth, is associated with a high risk of either death or a lifetime with disability. In recent multicenter clinical trials, hypothermia initiated within the first 6 postnatal hours has emerged as a therapy that reduces the risk of death or impairment among infants with hypoxic–ischemic encephalopathy. Prior to hypothermia, no therapies directly targeting neonatal encephalopathy secondary to hypoxic–ischemic injury had convincing evidence of efficacy. Hypothermia therapy is now becoming increasingly available at tertiary centers. Despite the deserved enthusiasm for hypothermia, obstetric and neonatology caregivers, as well as society at large, must be reminded that in the clinical trials more than 40% of cooled infants died or survived with impairment. Although hypothermia is an evidence-based therapy, additional discoveries are needed to further improve outcome after HIE. In this article, we briefly present the epidemiology of neonatal encephalopathy due to hypoxic–ischemic injury, describe the rationale for the use of hypothermia therapy for hypoxic–ischemic encephalopathy, and present results of the clinical trials that have demonstrated the efficacy of hypothermia. We also present findings noted during and after these trials that will guide care and direct research for this devastating problem. PMID:20625441

  4. Mechanism of ischemic contracture in ferret hearts: relative roles of [Ca2+]i elevation and ATP depletion.

    PubMed

    Koretsune, Y; Marban, E

    1990-01-01

    When coronary perfusion is interrupted, the diastolic force generated by the myocardium first falls but eventually increases. The delayed rise in force, ischemic contracture, has been attributed either to ATP depletion or to elevation of the intracellular free calcium concentration ([Ca2+]i). To distinguish between these possibilities, we measured [Ca2+]i and ATP concentration [( ATP]) in ferret hearts using nuclear magnetic resonance (NMR) spectroscopy. Mean time-average [Ca2+]i and [ATP] equaled 0.25 microM and 2.7 mumol/g wet wt, respectively, under control perfusion conditions. [Ca2+]i increased and [ATP] fell during total global ischemia. Although [Ca2+]i exceeded the usual systolic levels of 1.7 microM within 20-25 min of ischemia and reached a steady level between 2 and 3 microM by 30-35 min, force only began to rise after 40 min. In contrast, the time required for [ATP] to fall to less than 10% of control levels coincided closely with the onset of contracture. Ischemia in the presence of iodoacetate, an inhibitor of glycolysis, led to a precipitous fall in [ATP] and a concomitant rise in force, both of which preceded any elevation of [Ca2+]i. Thus changes in [Ca2+]i are neither sufficient nor necessary for the initiation of ischemic contracture. We conclude that ATP depletion is primary and that the rise in resting force reflects the formation of rigor cross bridges.

  5. [Echocardiographic evaluation of ischemic cardiopathy].

    PubMed

    Asin Cardiel, E; Yuste, P; Señor, J; Palma, J; Martínez-Bordiu, C

    1976-01-01

    We studied a group of patients with ischemic heart disease divided into two groups: Group I coronary insufficiency. Group II myocardial infaction. We centered the work on the following aspects: analysis of the contractility; evaluation of the movement of the ventricular wall and of the septum; movement of the mitral valve; diagnosis of ventricular dyskinesias, akinesias, and hypokinesias. The patients in group I did not show significant alterations in the values of the ejection fraction and speed of circunferential shortening. The mean values of these parimeters are significantly less than the group of patients with infarcts, and 41% of these patients have EF less than 50% and Vcf less than 0.9. We did not find a correlation between these perimeters and the localization of the infarct. The velocity of the posterior ventricular wall was disminished in both groups of patients. The amplitude of movement of the posterior wall was reduced in the group of patients with infarctions. These parimeters were more altered in the posterior infarcts than in those with anterior localization and they are more an index of the state of the posterior wall than of the ventricular contractility considered overall, contary to mitral descriptions. In 3 cases of acute infarct we found paradoxical movement of the septum, which normalized itself in one patient in 6 months. In 6 other patients with old infarct we observed localized dyskinesias of the septum and of the free wall of the left ventricle. The mitral valve appears altered in a great proportion of coronary patients the most notorious characteristics being: a decrease in the EF pendent; an increase of the F index. These findings are considered in relation with the ventricular pressures and with the degree of distensibility of the left ventricle.

  6. Perfusion harmonic imaging of the human brain

    NASA Astrophysics Data System (ADS)

    Metzler, Volker H.; Seidel, Guenter; Wiesmann, Martin; Meyer, Karsten; Aach, Til

    2003-05-01

    The fast visualisation of cerebral microcirculation supports diagnosis of acute cerebrovascular diseases. However, the commonly used CT/MRI-based methods are time consuming and, moreover, costly. Therefore we propose an alternative approach to brain perfusion imaging by means of ultrasonography. In spite of the low signal/noise-ratio of transcranial ultrasound and the high impedance of the skull, flow images of cerebral blood flow can be derived by capturing the kinetics of appropriate contrast agents by harmonic ultrasound image sequences. In this paper we propose three different methods for human brain perfusion imaging, each of which yielding flow images indicating the status of the patient's cerebral microcirculation by visualising local flow parameters. Bolus harmonic imaging (BHI) displays the flow kinetics of bolus injections, while replenishment (RHI) and diminution harmonic imaging (DHI) compute flow characteristics from contrast agent continuous infusions. RHI measures the contrast agents kinetics in the influx phase and DHI displays the diminution kinetics of the contrast agent acquired from the decay phase. In clinical studies, BHI- and RHI-parameter images were found to represent comprehensive and reproducible distributions of physiological cerebral blood flow. For DHI it is shown, that bubble destruction and hence perfusion phenomena principally can be displayed. Generally, perfusion harmonic imaging enables reliable and fast bedside imaging of human brain perfusion. Due to its cost efficiency it complements cerebrovascular diagnostics by established CT/MRI-based methods.

  7. Real time cardiac radionuclide imaging

    SciTech Connect

    Jarkewicz, G.G.

    1986-04-29

    A data acquisition system is described for use in radionuclide cardiac imaging of a patient having been administered a myocardium specific radionuclide, comprising: (a) means for monitoring the electrical activity of the heart; (b) first temporary storage means for accumulating respective pages of data corresponding to nuclear events during each cardiac cycle; (c) means, responsive to the means for monitoring, for determining the time duration of each successive cardiac cycle; (d) means for comparing each determined duration of a cardiac cycle with a preselected time duration range; (e) second temporary storage means; and (f) means for conditionally transferring pages of data from the first temporary storage means to the second temporary storage means if the measured duration associated with each page has predetermined correspondence with the preselected duration range, whereby pages of data having the predetermined correspondence may be collated into a quasi-real time study, while pages of data having different correspondence with the preselected time duration range are discarded from the study.

  8. Hysterosalpingo-radionuclide scintigraphy (HERS)

    SciTech Connect

    Iturralde, M.; Venter, P.F.

    1981-10-01

    A radionuclide procedure, hysterosalpingo-radionuclide scintigraphy (HERS), was designed to evaluate the migration of a particulate radioactive tracer from the vagina to the peritoneal cavity and ovaries as well as to image and functionally outline the patency of the pathways between these two extremes of the female reproductive system. Technetium-99m human albumin microspheres (99mTc-HAM) were deposited in the posterior fornices of patients who were divided into two specific groups. Group I consisted of patients who were to undergo different elective gynecologic operations, in which besides obtaining sequential images, radioactivity levels were measured in the removed organs and tissues. Group II consisted of patients referred by the Infertility Clinic for evaluation of their reproductive system pathways patency. In this latter group, HERS was compared with contrast hysterosalpingography (HSG) and peritoneoscopy (PCP). The results obtained from measurements of radioactivity levels on the removed surgical specimens and comparison with other conventional gynecologic diagnostic procedures provide accurate evidence of the migration of 99mTc-HAM from the vagina, through the uterus and tubes, to the peritoneal cavity and ovaries, and show that HERS is a simple noninvasive method for functionally imaging and assessing the patency of the female reproductive system pathways.

  9. Combination therapy with normobaric oxygen (NBO) plus thrombolysis in experimental ischemic stroke

    PubMed Central

    Fujiwara, Norio; Murata, Yoshihiro; Arai, Ken; Egi, Yasuhiro; Lu, Jie; Wu, Ona; Singhal, Aneesh B; Lo, Eng H

    2009-01-01

    Background The widespread use of tissue plasminogen activator (tPA), the only FDA-approved acute stroke treatment, remains limited by its narrow therapeutic time window and related risks of brain hemorrhage. Normobaric oxygen therapy (NBO) may be a useful physiological strategy that slows down the process of cerebral infarction, thus potentially allowing for delayed or more effective thrombolysis. In this study we investigated the effects of NBO started simultaneously with intravenous tPA, in spontaneously hypertensive rats subjected to embolic middle cerebral artery (MCA) stroke. After homologous clot injection, animals were randomized into different treatment groups: saline injected at 1 hour; tPA at 1 hour; saline at 1 hour plus NBO; tPA at 1 hour plus NBO. NBO was maintained for 3 hours. Infarct volume, brain swelling and hemorrhagic transformation were quantified at 24 hours. Outcome assessments were blinded to therapy. Results Upon clot injection, cerebral perfusion in the MCA territory dropped below 20% of pre-ischemic baselines. Both tPA-treated groups showed effective thrombolysis (perfusion restored to nearly 100%) and smaller infarct volumes (379 ± 57 mm3 saline controls; 309 ± 58 mm3 NBO; 201 ± 78 mm3 tPA; 138 ± 30 mm3 tPA plus NBO), showing that tPA-induced reperfusion salvages ischemic tissue and that NBO does not significantly alter this neuroprotective effect. NBO had no significant effect on hemorrhagic conversion, brain swelling, or mortality. Conclusion NBO can be safely co-administered with tPA. The efficacy of tPA thrombolysis is not affected and there is no induction of brain hemorrhage or edema. These experimental results require clinical confirmation. PMID:19604385

  10. Implantation of a Novel Allogeneic Mesenchymal Precursor Cell Type in Patients with Ischemic Cardiomyopathy Undergoing Coronary Artery Bypass Grafting: an Open Label Phase IIa Trial.

    PubMed

    Anastasiadis, Kyriakos; Antonitsis, Polychronis; Westaby, Stephen; Reginald, Ajan; Sultan, Sabena; Doumas, Argirios; Efthimiadis, George; Evans, Martin John

    2016-06-01

    Heart failure is a life-limiting condition affecting over 40 million patients worldwide. Ischemic cardiomyopathy (ICM) is the most common cause. This study investigates in situ cardiac regeneration utilizing precision delivery of a novel mesenchymal precursor cell type (iMP) during coronary artery bypass surgery (CABG) in patients with ischemic cardiomyopathy (LVEF < 40 %). The phase IIa safety study was designed to enroll 11 patients. Preoperative scintigraphy imaging (SPECT) was used to identify hibernating myocardium not suitable for conventional myocardial revascularization for iMP implantation. iMP cells were implanted intramyocardially in predefined viable peri-infarct areas that showed poor perfusion, which could not be grafted due to poor target vessel quality. Postoperatively, SPECT was then used to identify changes in scar area. Intramyocardial implantation of iMP cells with CABG was safe with preliminary evidence of efficacy of improved myocardial contractility and perfusion of nonrevascularized territories resulting in a significant reduction in left ventricular scar area at 12 months after treatment. Clinical improvement was associated with a significant improvement in quality of life at 6 months posttreatment in all patients. The results suggest the potential for in situ myocardial regeneration in ischemic heart failure by delivery of iMP cells. PMID:27037806

  11. [Absorption of amino acids from the perfused ovine rumen].

    PubMed

    L' Leng; Tomás, J; Várady, J; Szányiová, M

    1978-06-01

    The experiments with extracoroporeal perfusion of sheep rumen were performed [Leng et al., 1977]. Bovine plasma, diluted in a 1:1ratio with an isotonic solution of sodium chloride, was used for four perfusions, and autologous blood was used for two perfusions in the course of 150 minutes. After 60 minutes perfusion 20 g enzymatic casein hydrolyzate were applied to the rumen. The levels of free amino acids in the perfusate were recorded after 60 minutes' perfusion [the first phase of perfusion] and at the end of the experiment [the second phase]. The levels of lysine, aspartic acid and glutamic acid increased after perfusions with bovine plasma during the first phase, the levels of glutamic acid, phenylalanine, and in one case of alanine, increased after perfusions with autologus blood. Simultaneously the level of valine decreased after perfusions with bovine plasma, and after perfusions with blood the levels of arginine and valine, and/or lysine, dropped. During the second phase of perfusion, the levels of all the observed amino acids except methionine [bovine plasma], and/or orginine and methionine [blood] rose in the perfusate. The experiments showed that the level of amino acids in the rumen content presented a decisive factor affecting amino acid absorption from the rumen into the blood. Transformation of the amino acids during their passage through the remen wall may be assumed, and glutamic acid is one of the chief products of this process.

  12. Cardiac magnetic resonance determinants of functional mitral regurgitation in ischemic and non ischemic left ventricular dysfunction.

    PubMed

    Fernández-Golfín, Covadonga; De Agustin, Alberto; Manzano, M Carmen; Bustos, Ana; Sánchez, Tibisay; Pérez de Isla, Leopoldo; Fuentes, Manuel; Macaya, Carlos; Zamorano, José

    2011-04-01

    Functional mitral regurgitation (FMR) is frequent in left ventricular (LV) dilatation/dysfunction. Echocardiographic predictors of FMR are known. However, cardiac magnetic resonance (CMR) predictors of FMR have not been fully addressed. The aim of the study was to evaluate CMR mitral valve (MV) parameters associated with FMR in ischemic and non ischemic LV dysfunction. 80 patients with LV ejection fraction below 45% and/or left ventricular dilatation of ischemic and non ischemic etiology were included. Cine-MR images (steady state free-precession) were acquired in a short-axis and 4 chambers views where MV evaluation was performed. Delayed enhancement was performed as well. Significant FMR was established as more than mild MR according to the echocardiographic report. Mean age was 59 years, males 79%. FMR was detected in 20 patients (25%) Significant differences were noted in LV functional parameters and in most MV parameters according to the presence of significant FMR. However, differences were noted between ischemic and non ischemic groups. In the first, differences in most MV parameters remained significant while in the non ischemic, only systolic and diastolic interpapillary muscle distance (1.60 vs. 2.19 cm, P = 0.001; 2. 51 vs. 3.04, P = 0.008) were predictors of FMR. FMR is associated with a more severe LV dilatation/dysfunction in the overall population. CMR MV parameters are associated with the presence of significant FMR and are different between ischemic and non ischemic patients. CMR evaluation of these patients may help in risk stratification as well as in surgical candidate selection.

  13. Spectroscopic Monitoring of Kidney Tissue Ischemic Injury

    SciTech Connect

    Demos, S G; Fitzgerald, J T; Michalopoulou, A P; Troppmann, C

    2004-03-11

    Noninvasive evaluation of tissue viability of donor kidneys used for transplantation is an issue that current technology is not able to address. In this work, we explore optical spectroscopy for its potential to assess the degree of ischemic damage in kidney tissue. We hypothesized that ischemic damage to kidney tissue will give rise to changes in its optical properties which in turn may be used to asses the degree of tissue injury. The experimental results demonstrate that the autofluorescence intensity of the injured kidney is decreasing as a function of time exposed to ischemic injury. Changes were also observed in the NIR light scattering intensities most probably arising from changes due to injury and death of the tissue.

  14. Resilience in Patients with Ischemic Heart Disease

    PubMed Central

    de Lemos, Conceição Maria Martins; Moraes, David William; Pellanda, Lucia Campos

    2016-01-01

    Background Resilience is a psychosocial factor associated with clinical outcomes in chronic diseases. The relationship between this protective factor and certain diseases, such heart diseases, is still under-explored. Objective The present study sought to investigate the frequency of resilience in individuals with ischemic heart disease. Method This was a cross-sectional study with 133 patients of both genders, aged between 35 and 65 years, treated at Rio Grande do Sul Cardiology Institute - Cardiology University Foundation, with a diagnosis of ischemic heart disease during the study period. Sixty-seven patients had a history of acute myocardial infarction. The individuals were interviewed and evaluated by the Wagnild & Young resilience scale and a sociodemographic questionnaire. Results Eighty-one percent of patients were classified as resilient according to the scale. Conclusion In the sample studied, resilience was identified in high proportion among patients with ischemic heart disease. PMID:26815312

  15. Cerebrovascular arteriopathy (arteriosclerosis) and ischemic childhood stroke.

    PubMed

    Daniels, S R; Bates, S; Lukin, R R; Benton, C; Third, J; Glueck, C J

    1982-01-01

    The aim of this report is to describe the intracranial cerebrovascular abnormalities and clinical status of 8 children who had familial lipoprotein disorders and evidence of thromboembolic cerebrovascular disease. Six of the 8 children had low levels of plasma high density lipoprotein cholesterol, two had high triglyceride levels, and all came from kindreds characterized by familial lipoprotein abnormalities and premature cardio- and/or cerebrovascular atherosclerosis. Vascular occlusion, irregularities of the arterial lumen, beading, tortuosity, and evidence of collateralization were consistently noted. We speculate that cerebrovascular arteriosclerosis in pediatric ischemic stroke victims who have familial lipoprotein abnormalities may be related to lipoprotein-mediated endothelial damage and thrombosis formation, or to the failure to restore endothelial cells' integrity following damage. The apparent association of lipoproteins and strokes in children and their families merits further exploration, particularly when assessing cerebral angiograms in pediatric ischemic stroke victims. In children with unexplained ischemic cerebrovascular accidents, the diagnostic possibility of occlusive arteriosclerosis with thrombosis must be entertained.

  16. [Vascular brain lesions and ischemic heart disease].

    PubMed

    Levin, G Z

    1979-01-01

    The role of essential hypertension in the pathogenesis of cerebral vessel disorders (not only hemorrhagic, but also ischemic) is greater than in the pathogenesis of the heart ischemic disease. An analysis of the evidences left by ancient doctors, when compared with statistical data of our time, gives one grounds to believe that cerebral hemorrhages have been a rather common disease, at least, since the time of the antique civilization of Greece and Rome, whereas ischemic heart disease has become a widespread disease among the population of the developed countries only in our time. This makes it possible to assume that the role of essential hypertension and that of atherosclerosis are not equal in the "diseases of civilization", if the diseases of today's developed society are meant.

  17. The association of migraine with ischemic stroke.

    PubMed

    Kurth, Tobias

    2010-03-01

    Migraine is a common, chronic-intermittent primary headache disorder affecting mostly women. The migraine pathophysiology involves both the neuronal and vascular systems, and in some patients, transient neurologic symptoms occur, which are known as migraine aura. A large body of literature supports an association between migraine and ischemic stroke, which is apparent mostly in young women with migraine with aura. Further increased risks have been observed particularly in smokers and women who use oral contraceptives. The vast majority of individual studies, as well as a recent meta-analysis, did not find an association between migraine without aura and ischemic stroke. Although there are several hypotheses about potential biological mechanisms linking migraine with aura to ischemic stroke, the precise causes remain unclear. Because the absolute risk of stroke is considerably low in patients with migraine, the vast majority of migraine patients will not experience a stroke event because of the migraine.

  18. Modeling Radionuclide Decay Chain Migration Using HYDROGEOCHEM

    NASA Astrophysics Data System (ADS)

    Lin, T. C.; Tsai, C. H.; Lai, K. H.; Chen, J. S.

    2014-12-01

    Nuclear technology has been employed for energy production for several decades. Although people receive many benefits from nuclear energy, there are inevitably environmental pollutions as well as human health threats posed by the radioactive materials releases from nuclear waste disposed in geological repositories or accidental releases of radionuclides from nuclear facilities. Theoretical studies have been undertaken to understand the transport of radionuclides in subsurface environments because that the radionuclide transport in groundwater is one of the main pathway in exposure scenarios for the intake of radionuclides. The radionuclide transport in groundwater can be predicted using analytical solution as well as numerical models. In this study, we simulate the transport of the radionuclide decay chain using HYDROGEOCHEM. The simulated results are verified against the analytical solution available in the literature. Excellent agreements between the numerical simulation and the analytical are observed for a wide spectrum of concentration. HYDROGECHEM is a useful tool assessing the ecological and environmental impact of the accidental radionuclide releases such as the Fukushima nuclear disaster where multiple radionuclides leaked through the reactor, subsequently contaminating the local groundwater and ocean seawater in the vicinity of the nuclear plant.

  19. Cardiac tissue engineering using perfusion bioreactor systems

    PubMed Central

    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

  20. Rest and exercise electrocardiograms and radionuclides in patients presenting for cardiac rehabilitation

    SciTech Connect

    Froelicher, V.F.; Sebrechts, C.; Streitwiesser, D.; Battler, A.; McKirnan, M.D.; Ashburn, W.

    1981-03-01

    The rest and exercise ECG, /sup 201/thallium myocardial scintigram (/sup 201/T1), and radionuclide ventriculography are noninvasive procedures which can be used to evaluate myocardial damage and ischemia. To compare these procedures and to obtain baseline information, 85 male patients with coronary heart disease were evaluated prior to beginning an exercise program. Findings at rest included Q waves or bundle branch block in 54%; 47% had /sup 201/T1 redistribution defects and 33% an abnormal ejection fraction (EF). Of the 39 patients with normal ECGs, 31 had no /sup 201/T1 defects and only of these 31 (3%) had an abnormal EF. Abnormal EF or /sup 201/T1 redistribution defects did not occur in patients without a history of myocardial infarction. Abnormal resting EF occurred in 63% of patients with abnormal versus 7% of those with normal /sup 201/T1 redistribution scans. Exercise test results included an abnormal ST-segment response in 80%, an abnormal EF response in 65%, and a /sup 201/T1 ischemic defect in 37%. Twenty patients had exercise-induced ST elevation, and this phenomenon was more related to ventricular aneurysms than to ischemia. /sup 201/Thallium imaging, radionuclide ventriculography, and the ECG provide results regarding myocardial damage that agree by more than chance, while the exercise induced ST-segment changes did not agree with the radionuclide indications of exercise-induced ischemia.

  1. Ischemic changes on rubidium-82 positron emission tomography imaging are associated with left ventricular functional and volumetric change independent of metabolic properties and echocardiographic functional variables in ischemic cardiomyopathy.

    PubMed

    Wong, Raymond C; Cerqueira, Manuel D; Brunken, Richard C

    2012-08-01

    Positron emission tomography (PET) imaging allows identification of stress-induced ischemia and myocardial viability in patients with ischemic cardiomyopathy. We assessed the left ventricular (LV) functional response to vasodilator stress in patients with advanced ischemic cardiomyopathy undergoing pharmacologic stress (PET) perfusion and metabolic imaging. Additionally, we aimed to determine if mitral regurgitation (MR), right ventricular (RV) dysfunction and diastolic function influenced the observed LV responses to pharmacologic stress. In 161 patients (81% men; 65 ± 13 years), PET and echocardiography were performed within a week for noninvasive evaluation of myocardial ischemia and viability (scored using 17-segment model), as well as ventricular and valvular function. Patients were stratified based on ischemic defects in any segments versus hibernation/scar defects only. The LV volumes, EF by gating and transient ischemic dilatation (TID) index were generated automatically. Wall thickening (WT) scores were determined visually. The subgroup with reversible/ischemic segments on PET imaging (N = 55) exhibited greater end-systolic (ESV) and end-diastolic volume (EDV) enlargement during stress (13 ± 22 and 16 ± 43 ml increase respectively, vs. 0 ± 18 ml [P < 0.0001] and 2 ± 24 ml [P = 0.01]), a decrease in LVEF during stress (mean -3% vs. +2%), and greater TID indices (mean 1.13 ± 0.18 vs. 1.02 ± 0.12) compared to hibernation/scar only (N = 92). In addition, mean WT scores during stress declined significantly only in the ischemic subgroup (P < 0.0001 for regional LAD, non-LAD and global wall thickening scores). The prevalence and the severity of MR and RV dysfunction did not differ between groups. By univariate analysis, global and LAD territory segmental ischemia, global sum stress score (SSS), TID index, resting EF, ESV enlargement during stress, as well as global WT changes correlated with post-stress LVEF decline. Multivariate predictors included SSS

  2. Neural Stem Cells and Ischemic Brain

    PubMed Central

    Zhang, Zhenggang; Chopp, Michael

    2016-01-01

    Stroke activates neural stem cells in the ventricular-subventricular zone (V/SVZ) of the lateral ventricle, which increases neuroblasts and oligodendrocyte progenitor cells (OPCs). Within the ischemic brain, neural stem cells, neuroblasts and OPCs appear to actively communicate with cerebral endothelial cells and other brain parenchymal cells to mediate ischemic brain repair; however, stroke-induced neurogenesis unlikely plays any significant roles in neuronal replacement. In this mini-review, we will discuss recent findings how intercellular communications between stroke-induced neurogenesis and oligodendrogenesis and brain parenchymal cells could potentially facilitate brain repair processes. PMID:27488979

  3. Ischemic Gastropathic Ulcer Mimics Gastric Cancer

    PubMed Central

    Daher, Saleh; Lahav, Ziv; Rmeileh, Ayman Abu; Mizrahi, Meir

    2016-01-01

    Gastric ulcer due to mesenteric ischemia is a rare clinical finding. As a result, few reports of ischemic gastric ulcers have been reported in the literature. The diagnosis of ischemic gastropathy is seldom considered in patients presenting with abdominal pain and gastric ulcers. In this case report, we describe a patient with increasing abdominal pain, weight loss, and gastric ulcers, who underwent extensive medical evaluation and whose symptoms were resistant to medical interventions. Finally he was diagnosed with chronic mesenteric ischemia, and his clinical and endoscopic abnormalities resolved after surgical revascularization of both the superior mesenteric artery and the celiac trunk. PMID:27579191

  4. Panic attack triggering myocardial ischemia documented by myocardial perfusion imaging study. A case report

    PubMed Central

    2012-01-01

    Background Chest pain, a key element in the investigation of coronary artery disease is often regarded as a benign prognosis when present in panic attacks. However, panic disorder has been suggested as an independent risk factor for long-term prognosis of cardiovascular diseases and a trigger of acute myocardial infarction. Objective Faced with the extreme importance in differentiate from ischemic to non-ischemic chest pain, we report a case of panic attack induced by inhalation of 35% carbon dioxide triggering myocardial ischemia, documented by myocardial perfusion imaging study. Discussion Panic attack is undoubtedly a strong component of mental stress. Patients with coronary artery disease may present myocardial ischemia in mental stress response by two ways: an increase in coronary vasomotor tone or a sympathetic hyperactivity leading to a rise in myocardial oxygen consumption. Coronary artery spasm was presumed to be present in cases of cardiac ischemia linked to panic disorder. Possibly the carbon dioxide challenge test could trigger myocardial ischemia by the same mechanisms. Conclusion The use of mental stress has been suggested as an alternative method for myocardial ischemia investigation. Based on translational medicine objectives the use of CO2 challenge followed by Sestamibi SPECT could be a useful method to allow improved application of research-based knowledge to the medical field, specifically at the interface of PD and cardiovascular disease. PMID:22999016

  5. Induction and Assessment of Ischemia-reperfusion Injury in Langendorff-perfused Rat Hearts

    PubMed Central

    Herr, Daniel J.; Aune, Sverre E.; Menick, Donald R.

    2015-01-01

    The biochemical events surrounding ischemia reperfusion injury in the acute setting are of great importance to furthering novel treatment options for myocardial infarction and cardiac complications of thoracic surgery. The ability of certain drugs to precondition the myocardium against ischemia reperfusion injury has led to multiple clinical trials, with little success. The isolated heart model allows acute observation of the functional effects of ischemia reperfusion injury in real time, including the effects of various pharmacological interventions administered at any time-point before or within the ischemia-reperfusion injury window. Since brief periods of ischemia can precondition the heart against ischemic injury, in situ aortic cannulation is performed to allow for functional assessment of non-preconditioned myocardium. A saline filled balloon is placed into the left ventricle to allow for real-time measurement of pressure generation. Ischemic injury is simulated by the cessation of perfusion buffer flow, followed by reperfusion. The duration of both ischemia and reperfusion can be modulated to examine biochemical events at any given time-point. Although the Langendorff isolated heart model does not allow for the consideration of systemic events affecting ischemia and reperfusion, it is an excellent model for the examination of acute functional and biochemical events within the window of ischemia reperfusion injury as well as the effect of pharmacological intervention on cardiac pre- and postconditioning. The goal of this protocol is to demonstrate how to perform in situ aortic cannulation and heart excision followed by ischemia/reperfusion injury in the Langendorff model. PMID:26274877

  6. Inventory of radionuclides for the Great Lakes

    SciTech Connect

    1997-12-31

    This report uses a material balance approach to describe the quantities and composition of reported releases of radionuclides to air and water, and the distribution of these nuclides in atmospheric, aquatic, and biotic compartments of the Great Lakes ecosystem. The primary sources considered are discharges from nuclear fuel cycle facilities in the Great Lakes Basin. Other sources include commercial, industrial, medical, and research institutions. Radionuclide inventories are first presented by source, both natural and anthropogenic, then by geographical and environmental distribution. The concluding section discusses the adequacy of radionuclide monitoring, the need for a reassessment of environmental monitoring of nuclear facilities, radionuclide data reporting, harmonization of monitoring and data reporting, biological transfer factors for lake systems, and radionuclides of concern. A glossary is included.

  7. Detecting low levels of radionuclides in fluids

    DOEpatents

    Patch, Keith D.; Morgan, Dean T.

    2000-01-01

    An apparatus and method for detecting low levels of one or more radionuclides in a fluid sample uses a substrate that includes an ion exchange resin or other sorbent material to collect the radionuclides. A collecting apparatus includes a collecting chamber that exposes the substrate to a measured amount of the fluid sample such that radionuclides in the fluid sample are collected by the ion exchange resin. A drying apparatus, which can include a drying chamber, then dries the substrate. A measuring apparatus measures emissions from radionuclides collected on the substrate. The substrate is positioned in a measuring chamber proximate to a detector, which provides a signal in response to emissions from the radionuclides. Other analysis methods can be used to detect non-radioactive analytes, which can be collected with other types of sorbent materials.

  8. Perfusion safety: new initiatives and enduring principles.

    PubMed

    Kurusz, M

    2011-09-01

    Perfusion safety has been studied and discussed extensively for decades. Many initiatives occurred through efforts of professional organizations to achieve recognition, establish accreditation and certification, promote consensus practice guidelines, and develop peer-reviewed journals as sources for dissemination of clinical information. Newer initiatives have their basis in other disciplines and include systems approach, Quality Assurance/Quality Improvement processes, error recognition, evidence-based methodologies, registries, equipment automation, simulation, and the Internet. Use of previously established resources such as written protocols, checklists, safety devices, and enhanced communication skills has persisted to the present in promoting perfusion safety and has reduced current complication rates to negligible levels.

  9. Normothermic ex vivo perfusion prevents lung injury compared to extended cold preservation for transplantation.

    PubMed

    Cypel, M; Rubacha, M; Yeung, J; Hirayama, S; Torbicki, K; Madonik, M; Fischer, S; Hwang, D; Pierre, A; Waddell, T K; de Perrot, M; Liu, M; Keshavjee, S

    2009-10-01

    Treatment of injured donor lungs ex vivo to accelerate organ recovery and ameliorate reperfusion injury could have a major impact in lung transplantation. We have recently demonstrated a feasible technique for prolonged (12 h) normothermic ex vivo lung perfusion (EVLP). This study was performed to examine the impact of prolonged EVLP on ischemic injury. Pig donor lungs were cold preserved in Perfadex for 12 h and subsequently divided into two groups: cold static preservation (CSP) or EVLP at 37 degrees C with Steen solution for a further 12 h (total 24 h preservation). Lungs were then transplanted and reperfused for 4 h. EVLP preservation resulted in significantly better lung oxygenation (PaO(2) 531 +/- 43 vs. 244 +/- 49 mmHg, p < 0.01) and lower edema formation rates after transplantation. Alveolar epithelial cell tight junction integrity, evaluated by zona occludens-1 protein staining, was disrupted in the cell membranes after prolonged CSP but not after EVLP. The maintenance of integrity of barrier function during EVLP translates into significant attenuation of reperfusion injury and improved graft performance after transplantation. Integrity of functional metabolic pathways during normothermic perfusion was confirmed by effective gene transfer and GFP protein synthesis by lung alveolar cells. In conclusion, EVLP prevents ongoing injury associated with prolonged ischemia and accelerates lung recovery. PMID:19663886

  10. Performance comparison between static and dynamic cardiac CT on perfusion quantitation and patient classification tasks

    NASA Astrophysics Data System (ADS)

    Bindschadler, Michael; Modgil, Dimple; Branch, Kelley R.; La Riviere, Patrick J.; Alessio, Adam M.

    2015-03-01

    Cardiac CT acquisitions for perfusion assessment can be performed in a dynamic or static mode. In this simulation study, we evaluate the relative classification and quantification performance of these modes for assessing myocardial blood flow (MBF). In the dynamic method, a series of low dose cardiac CT acquisitions yields data on contrast bolus dynamics over time; these data are fit with a model to give a quantitative MBF estimate. In the static method, a single CT acquisition is obtained, and the relative CT numbers in the myocardium are used to infer perfusion states. The static method does not directly yield a quantitative estimate of MBF, but these estimates can be roughly approximated by introducing assumed linear relationships between CT number and MBF, consistent with the ways such images are typically visually interpreted. Data obtained by either method may be used for a variety of clinical tasks, including 1) stratifying patients into differing categories of ischemia and 2) using the quantitative MBF estimate directly to evaluate ischemic disease severity. Through simulations, we evaluate the performance on each of these tasks. The dynamic method has very low bias in MBF estimates, making it particularly suitable for quantitative estimation. At matched radiation dose levels, ROC analysis demonstrated that the static method, with its high bias but generally lower variance, has superior performance in stratifying patients, especially for larger patients.

  11. Circular tomosynthesis for neuro perfusion imaging on an interventional C-arm

    NASA Astrophysics Data System (ADS)

    Claus, Bernhard E.; Langan, David A.; Al Assad, Omar; Wang, Xin

    2015-03-01

    There is a clinical need to improve cerebral perfusion assessment during the treatment of ischemic stroke in the interventional suite. The clinician is able to determine whether the arterial blockage was successfully opened but is unable to sufficiently assess blood flow through the parenchyma. C-arm spin acquisitions can image the cerebral blood volume (CBV) but are challenged to capture the temporal dynamics of the iodinated contrast bolus, which is required to derive, e.g., cerebral blood flow (CBF) and mean transit time (MTT). Here we propose to utilize a circular tomosynthesis acquisition on the C-arm to achieve the necessary temporal sampling of the volume at the cost of incomplete data. We address the incomplete data problem by using tools from compressed sensing and incorporate temporal interpolation to improve our temporal resolution. A CT neuro perfusion data set is utilized for generating a dynamic (4D) volumetric model from which simulated tomo projections are generated. The 4D model is also used as a ground truth reference for performance evaluation. The performance that may be achieved with the tomo acquisition and 4D reconstruction (under simulation conditions, i.e., without considering data fidelity limitations due to imaging physics and imaging chain) is evaluated. In the considered scenario, good agreement between the ground truth and the tomo reconstruction in the parenchyma was achieved.

  12. NIR fluorescent image-based evaluation of gastric tube perfusion after esophagectomy in preclinical model (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kim, Minji; Quan, Yuhua; Han, Kook Nam; Choi, Byeong Hyun; Choi, Yeonho; Kim, Hyun Koo; Kim, Beop-Min

    2016-03-01

    This study was to evaluate the feasibility of near infrared (NIR) fluorescent images as a tool for evaluating the perfusion of the gastric tube after esophagectomy. In addition, we investigated the time required to acquire enough signal to confirm the presence of ischemia in gastric tube after injection of indocyanine green (ICG) through peripheral versus and central venous route. 4 porcine underwent esophagogastrostomy and their right gastric arteries were ligated to mimic ischemic condition of gastric tube. ICG (0.6mg/kg) was intravenously injected and the fluorescence signal-to-background ratios (SBR) were measured by using the custom-built intraoperative color and fluorescence imaging system (ICFIS). We evaluated perfusion of gastric tubes by comparing their SBR with esophageal SBR. In ischemic models, SBR of esophagus was higher than that of gastric tube (2.8+/-0.54 vs. 1.7+/-0.37, p<0.05). It showed high esophagus-stomach signal to signal ratio. (SSR, 1.8+/-0.76). We also could observe recovery of blood perfusion in few minutes after releasing the ligation of right gastric artery. In addition, in comparison study according to the injection route of ICG, The time to acquire signal stabilization was faster in central than in peripheral route (119 +/- 65.1 seconds in central route vs. 295+/-130.4 in peripheral route, p<0.05). NIR fluorescent images could provide the real-time information if there was ischemia or not in gastric tube during operation. And, central injection of ICG might give that information faster than peripheral route.

  13. Liver free fatty acid (FFA) accumulation as an indicator of ischemic injury during cold preservation

    SciTech Connect

    Nemoto, E.M.; Kang, Y.; DeWolf, A.M.; Lin, M.R.; Bleyaert, A.L.; Winter, P.M.

    1987-05-01

    Reliable assessment of hepatic viability prior to harvest and transplant could improve graft success and aid in evaluating the efficacy of liver preservation techniques. Hepatic tissue metabolites, protein (Pr) synthesis, and ATP have been studied, but none reliably correlate with hepatic viability. Therefore, they studied changes in liver FFA relative to changes in ATP and Pr synthesis during cold ischemic preservation. Rats mechanically ventilated on 0.5% isoflurane/70% N/sub 2/O/30% O/sub 2/ were heparinized and their livers perfused with air-equilibrated Euro-Collins solution (ECS) at 0-4/sup 0/C and kept on ice. A piece of the liver was removed after 0, 2, 6, 8, 12, 24, 36 and 48 h of preservation for ATP and FFA analysis. A portion of the liver was sliced (250 ..mu..m thick) and incubated in vitro for /sup 14/C-lysine incorporation in albumin. ATP, FFA and Pr synthesis were unchanged in the first 8 h, but markedly decreased between 8 and 12 h with little change thereafter. In contrast, between 8 and 48 h, arachidonic and stearic acids increased by 5 and 2-fold, respectively. Changes in ATP and Pr synthesis correlate with the empirically derived clinical maximum of 8 to 12 h preservation. FFA accumulation appears to reflect hepatic ischemic injury and may be a means of evaluating the quality of a donor liver.

  14. Mechanism of antifibrillatory action of Org 7797 in regionally ischemic pig heart.

    PubMed

    Janse, M J; Wilms-Schopman, F; Opthof, T

    1990-04-01

    Org 7797 is effective against ventricular fibrillation (VF) induced during ischemia. In Langendorff-perfused pig hearts, application of three premature stimuli to nonischemic myocardium between 3 and 5 min after coronary occlusion always resulted in VF in the absence of drug. In no instance when Org 7797 was present (2-10 microM) could VF be induced, although sustained and nonsustained ventricular tachycardias (VTs) could still be initiated in about two thirds of treated hearts. We determined the effects of Org 7797 on wavelength in normal and ischemic myocardium during regular driving at a cycle length of 350 ms. Wavelength, the algebraic product of conduction velocity and refractory period, is considered a useful parameter in assessing efficacy of antiarrhythmic agents in preventing reentrant arrhythmias. Conduction velocity was obtained by analyzing the spread of activation under 121 unipolar electrodes (1 mm apart) placed around a central stimulus electrode. Refractory periods were determined with premature test stimuli at an intensity of twice diastolic threshold. Both in normal and ischemic myocardium Org 7797 (5-10 microM) produced a marked shortening of wavelength. This should predispose to reentry. However, Org 7797 prolonged the refractory period at the fastest possible driving rate from 154 to 247 ms and attenuated (5 microM) or prevented (10 microM) shortening of the refractory period during application of subsequent premature stimuli. The antifibrillatory effect of the drug may be explained by prolongation of wavelength at very short cycles.

  15. Ischemic post-conditioning to counteract intestinal ischemia/reperfusion injury

    PubMed Central

    Guan, Yan-Fang; Pritts, Timothy A; Montrose, Marshall H

    2010-01-01

    Intestinal ischemia is a severe disorder with a variety of causes. Reperfusion is a common occurrence during treatment of acute intestinal ischemia but the injury resulting from ischemia/reperfusion (IR) may lead to even more serious complications from intestinal atrophy to multiple organ failure and death. The susceptibility of the intestine to IR-induced injury (IRI) appears from various experimental studies and clinical settings such as cardiac and major vascular surgery and organ transplantation. Whereas oxygen free radicals, activation of leukocytes, failure of microvascular perfusion, cellular acidosis and disturbance of intracellular homeostasis have been implicated as important factors in the pathogenesis of intestinal IRI, the mechanisms underlying this disorder are not well known. To date, increasing attention is being paid in animal studies to potential pre- and post-ischemia treatments that protect against intestinal IRI such as drug interference with IR-induced apoptosis and inflammation processes and ischemic pre-conditioning. However, better insight is needed into the molecular and cellular events associated with reperfusion-induced damage to develop effective clinical protection protocols to combat this disorder. In this respect, the use of ischemic post-conditioning in combination with experimentally prolonged acidosis blocking deleterious reperfusion actions may turn out to have particular clinical relevance. PMID:21607154

  16. Endovascular ischemic stroke models of adult rhesus monkeys: a comparison of two endovascular methods

    PubMed Central

    Wu, Di; Chen, Jian; Wang, Bincheng; Zhang, Mo; Shi, Jingfei; Ma, Yanhui; Zhu, Zixin; Yan, Feng; He, Xiaoduo; Li, Shengli; Dornbos III, David; Ding, Yuchuan; Ji, Xunming

    2016-01-01

    To further investigate and improve upon current stroke models in nonhuman primates, infarct size, neurologic function and survival were evaluated in two endovascular ischemic models in sixteen rhesus monkeys. The first method utilized a micro-catheter or an inflatable balloon to occlude the M1 segment in six monkeys. In the second model, an autologous clot was injected via a micro-catheter into the M1 segment in ten monkeys. MRI scanning was performed on all monkeys both at baseline and 3 hours after the onset of ischemia. Spetzler neurologic functions were assessed post-operatively, and selective perfusion deficits were confirmed by DSA and MRI in all monkeys. Animals undergoing micro-catheter or balloon occlusion demonstrated more profound hemiparesis, larger infarct sizes, lower Spetzler neurologic scores and increased mortality compared to the thrombus occlusion group. In animals injected with the clot, there was no evidence of dissolution, and the thrombus was either near the injection site (M1) or flushed into the superior division of the MCA (M2). All animals survived the M2 occlusion. M1 occlusion with thrombus generated 50% mortality. This study highlighted clinically important differences in these two models, providing a platform for further study of a translational thromboembolic model of acute ischemic stroke. PMID:27534985

  17. Ranolazine and Ivabradine: two different modalities to act against ischemic heart disease.

    PubMed

    Cacciapuoti, Federico

    2016-04-01

    Among the innovative drugs recently introduced for the management of chronic stable angina, Ranolazine and ivabradine represent two most true innovations. In fact, even if both drugs act by reducing myocardial work and thus oxygen consumption, this happens by a peculiar mechanism unlike that of conventional antischemic drugs. Ranolazine mediates its antianginal effects by the inhibition of cardiac late sodium current. This improves myocardial relaxation favoring myocardial perfusion. Ivabradine is a selective If channel blocker and acts by reducing firing rate of pacemaker cells in the sinoatrial node, without affecting the duration of action potential. The reduction of heart rate causes a reduction of left ventricular end diastolic pressure and increases the time useful to coronary flow by a prolongation of the diastole. A body of evidence found that two drugs are useful in ischemic patients whether at rest or during exercise. In addition, they can be used in monotherapy or in association with other conventional anti-ischemic drugs. The two medications could be used with advantage also in microvascular angina when standard therapy is ineffective. Thus, the two drugs represent an adjunctive and powerful therapeutic modality for the treatment of chronic stable angina, especially when conventional antianginal drugs were insufficient or inadequate. PMID:26944071

  18. Bone marrow and bone marrow derived mononuclear stem cells therapy for the chronically ischemic myocardium

    SciTech Connect

    Waksman, Ron; Baffour, Richard

    2003-09-01

    Bone marrow stem cells have been shown to differentiate into various phenotypes including cardiomyocytes, vascular endothelial cells and smooth muscle. Bone marrow stem cells are mobilized and home in to areas of injured myocardium where they are involved in tissue repair. In addition, bone marrow secretes multiple growth factors, which are essential for angiogenesis and arteriogenesis. In some patients, these processes are not enough to avert clinical symptoms of ischemic disease. Therefore, in vivo administration of an adequate number of stem cells would be a significant therapeutic advance. Unfractionated bone marrow derived mononuclear stem cells, which contain both hematopoietic and nonhematopoietic cells may be more appropriate for cell therapy. Studies in animal models suggest that implantation of different types of stem cells improve angiogenesis and arteriogenesis, tissue perfusion as well as left ventricular function. Several unanswered questions remain. For example, the optimal delivery approach, dosage and timing of the administration of cell therapy as well as durability of improvements need to be studied. Early clinical studies have demonstrated safety and feasibility of various cell therapies in ischemic disease. Randomized, double blind and placebo-controlled clinical trials need to be completed to determine the effectiveness of stem cell.

  19. Generation of in vivo activating factors in the ischemic intestine by pancreatic enzymes

    NASA Astrophysics Data System (ADS)

    Mitsuoka, Hiroshi; Kistler, Erik B.; Schmid-Schönbein, Geert W.

    2000-02-01

    One of the early events in physiological shock is the generation of activators for leukocytes, endothelial cells, and other cells in the cardiovascular system. The mechanism by which these activators are produced has remained unresolved. We examine here the hypothesis that pancreatic digestive enzymes in the ischemic intestine may be involved in the generation of activators during intestinal ischemia. The lumen of the small intestine of rats was continuously perfused with saline containing a broadly acting pancreatic enzyme inhibitor (6-amidino-2-naphthyl p-guanidinobenzoate dimethanesulfate, 0.37 mM) before and during ischemia of the small intestine by splanchnic artery occlusion. This procedure inhibited activation of circulating leukocytes during occlusion and reperfusion. It also prevented the appearance of activators in portal venous and systemic artery plasma and attenuated initiating symptoms of multiple organ injury in shock. Intestinal tissue produces only low levels of activators in the absence of pancreatic enzymes, whereas in the presence of enzymes, activators are produced in a concentration- and time-dependent fashion. The results indicate that pancreatic digestive enzymes in the ischemic intestine serve as an important source for cell activation and inflammation, as well as multiple organ failure.

  20. Ischemic penumbra in acute stroke: Demonstration by PET with fluorine-18 fluoromisonidazole

    SciTech Connect

    Yeh, S.H.; Liu, R.S.; Hu, H.H.

    1994-05-01

    Ischemic penumbra (IP) in acute stroke has gained clinical interest since tissue functions may be recovered if perfusion can be reestablished. However, such therapeutic intervention is {open_quotes}blind{close_quotes} since clinical examination can not distinguish IP from developing infarction. In vivo demonstration of IP may have significance for stroke patient management. This study was a preliminary evaluation of detecting IP in vivo by F-18 fluoromisonidazole ([F-18]-FMISO), a hypoxic imaging agent. Static PET imaging was performed after IV injection of 370 MBq of [F-18]-FMISO at 20 and 120 min. Tomograms were reconstructed and evaluated visually in correlation with CT or MR scans. In acute stroke, patients (pts) were called back for the second PET study one month after the initial study. CT was used for confirming infarction. In 6 pts with acute cerebral infarction, three of them had intense [F-18]-FMISO retention in the penumbra surrounding the central, eclipse-like zone of absent radio-activity (infarction) at 2 hr in the acute state, and the penumbra disappeared in association with increased area of infarction on CT in one case in the chronic state. In five pts with chronic infarction, all had no penumbra of [F-18]-FMISO retention. In summary, our preliminary results demonstrate the feasibility of using [F-18]-FMISO PET to detect ischemic penumbra in vivo.

  1. Effects of laser acupuncture on blood perfusion rate

    NASA Astrophysics Data System (ADS)

    Wang, Xian-ju; Zeng, Chang-chun; Liu, Han-ping; Liu, Song-hao; Liu, Liang-gang

    2006-09-01

    Based on Pennes equation, the influences of the intensity and the impulse frequency of laser acupuncture on the point tissues' blood flow perfusion rate are discussed. We find that the blood perfusion rate of point tissue increases with the intensity of laser acupuncture increasing. After impulse laser acupuncture the point tissue blood perfusion rate increase little, but after continuum laser acupuncture the point tissues blood perfusion rate increase much.

  2. [Design of the Rolling Type Nasal Feeding Perfusion Apparatus].

    PubMed

    Yu, Dong; Yang, Yonghuan; Hu, Huiqin; Luo, Hongjun; Feng, Yunhao; Hao, Xiali

    2015-09-01

    At present, the existing problem in nasal feeding perfusion apparatus is laborious and instability. Designing the rolling type perfusion apparatus by using a roller pump, the problem is solved. Compared with the traditional perfusion apparatus, the advantage lies in liquid carrying only need once and simulating human swallowing process. Through testing and verification, the apparatus can be used in nasal feeding perfusion for elderly or patients.

  3. Detection of cardiac allograft rejection using radionuclide techniques

    SciTech Connect

    Addonizio, L.J. )

    1990-09-01

    The results of the investigations in the search for a radionuclide technique to detect rejection have, thus far, not found any method that can be applied clinically. Functional studies are not sensitive enough, unless further work on the quantitative volume changes shows consistent correlation. Routine myocardial imaging agents such as {sup 67}Ga, {sup 99}TcPP, or the perfusion agent, {sup 201}Tl are clearly not specific enough to detect rejection until the grafts are nearly lost. Radiolabeled lymphocyte studies show promise, in that lymphocytes are intimately involved in the rejection process. However, there needs to be further research to determine if the specificity of the technique can isolate those patients who require treatment. The data involving labeled antimyosin antibody fragments indicate that they can specifically detect myocyte necrosis that occurs on the microscopic level. However, it may also be too sensitive a technique for transplanted hearts, which are so immunologically active at baseline to determine when treatment is necessary.30 references.

  4. Transverse section radionuclide scanning system

    DOEpatents

    Kuhl, David E.; Edwards, Roy Q.

    1976-01-01

    This invention provides a transverse section radionuclide scanning system for high-sensitivity quantification of brain radioactivity in cross-section picture format in order to permit accurate assessment of regional brain function localized in three-dimensions. High sensitivity crucially depends on overcoming the heretofore known raster type scanning, which requires back and forth detector movement involving dead-time or partial enclosure of the scan field. Accordingly, this invention provides a detector array having no back and forth movement by interlaced detectors that enclose the scan field and rotate as an integral unit around one axis of rotation in a slip ring that continuously transmits the detector data by means of laser emitting diodes, with the advantages that increased amounts of data can be continuously collected, processed and displayed with increased sensitivity according to a suitable computer program.

  5. Radionuclides in surface and groundwater

    USGS Publications Warehouse

    Campbell, Kate M.

    2009-01-01

    Unique among all the contaminants that adversely affect surface and water quality, radioactive compounds pose a double threat from both toxicity and damaging radiation. The extreme energy potential of many of these materials makes them both useful and toxic. The unique properties of radioactive materials make them invaluable for medical, weapons, and energy applications. However, mining, production, use, and disposal of these compounds provide potential pathways for their release into the environment, posing a risk to both humans and wildlife. This chapter discusses the sources, uses, and regulation of radioactive compounds in the United States, biogeochemical processes that control mobility in the environment, examples of radionuclide contamination, and current work related to contaminated site remediation.

  6. Cosmogenic radionuclides in stone meteorites

    NASA Technical Reports Server (NTRS)

    Cressy, P. J., Jr.

    1976-01-01

    This document presents the techniques and compilation of results of cosmogenic Al-26 measurements at Goddard Space Flight Center on 91 samples of 76 stone meteorites. Short-lived radionuclides, including Na-22, Sc-46, Mn-54, and Co-60, were measured in 13 of these meteorites. About one-third of these data has not previously been published. The results are discussed briefly in terms of (1) depletion of Al-26 and natural potassium due to weathering, (2) possible exposure of several chondrites to an unusually high cosmic-ray flux, (3) comparison of Al-26, Na-22, Sc-46, and Mn5-54 in chondrites with the spallation Ne-22/Ne-21 ratio as a shielding indicator, and (4) comparison of (Al-26)-(Ne-22)/Ne-21 data for achondrite classes with the chondrite trend.

  7. Fatty acid nitroalkenes induce resistance to ischemic cardiac injury by modulating mitochondrial respiration at complex II

    PubMed Central

    Koenitzer, Jeffrey R.; Bonacci, Gustavo; Woodcock, Steven R.; Chen, Chen-Shan; Cantu-Medellin, Nadiezhda; Kelley, Eric E.; Schopfer, Francisco J.

    2015-01-01

    Nitro-fatty acids (NO2-FA) are metabolic and inflammatory-derived electrophiles that mediate pleiotropic signaling actions. It was hypothesized that NO2-FA would impact mitochondrial redox reactions to induce tissue-protective metabolic shifts in cells. Nitro-oleic acid (OA-NO2) reversibly inhibited complex II-linked respiration in isolated rat heart mitochondria in a pH-dependent manner and suppressed superoxide formation. Nitroalkylation of Fp subunit was determined by BME capture and the site of modification by OA-NO2 defined by mass spectrometric analysis. These effects translated into reduced basal and maximal respiration and favored glycolytic metabolism in H9C2 cardiomyoblasts as assessed by extracellular H+ and O2 flux analysis. The perfusion of NO2-FA induced acute cardioprotection in an isolated perfused heart ischemia/reperfusion (IR) model as evidenced by significantly higher rate-pressure products. Together these findings indicate that NO2-FA can promote cardioprotection by inducing a shift from respiration to glycolysis and suppressing reactive species formation in the post-ischemic interval. PMID:26722838

  8. Factors affecting regional pulmonary blood flow in chronic ischemic heart disease

    SciTech Connect

    Pistolesi, M.; Miniati, M.; Bonsignore, M.; Andreotti, F.; Di Ricco, G.; Marini, C.; Rindi, M.; Biagini, A.; Milne, E.N.; Giuntini, C.

    1988-07-01

    To assess the effect of left heart disease on pulmonary blood flow distribution, we measured mean pulmonary arterial and wedge pressures, cardiac output, pulmonary vascular resistance, pulmonary blood volume, and arterial oxygen tension before and after treatment in 13 patients with longstanding ischemic heart failure and pulmonary edema. Pulmonary edema was evaluated by a radiographic score, and regional lung perfusion was quantified on a lung scan by the upper to lower third ratio (U:L ratio) of pulmonary blood flow per unit of lung volume. In all cases, redistribution of lung perfusion toward the apical regions was observed; this pattern was not affected by treatment. After treatment, pulmonary vascular pressures, resistance, and edema were reduced, while pulmonary blood volume did not change. At this time, pulmonary vascular resistance showed a positive correlation with the U:L ratio (r = 0.78; P less than 0.01), whereas no correlation was observed between U:L ratio and wedge pressure, pulmonary edema, or arterial oxygen tension. Hence, redistribution of pulmonary blood flow, in these patients, reflects chronic structural vascular changes prevailing in the dependent lung regions.

  9. The effects of cilostazol on tissue oxygenation upon an ischemic-reperfusion injury in the mouse cerebrum.

    PubMed

    Morikawa, Takayuki; Hattori, Katsuji; Kajimura, Mayumi; Suematsu, Makoto

    2010-01-01

    Although cilostazol, an inhibitor of cyclic nucleotide phosphodiesterase 3 (PDE3), is known to exert a potent antiplatelet function by raising intracellular cAMP concentration, its effect on cerebral microcirculation upon an ischemic insult is not clearly understood. To examine effects of cilostazol on the global ischemic injury in the brain, we first measured the plasma leakage using modified Miles assay after mice had been subjected to 60 min of a bilateral common carotid artery (BCCA) occlusion followed by reperfusion for 4 h. Oral treatment with cilostazol (30 mg/kg) significantly increased plasma leakage. This result led us to examine if the treatment with cilostazol recruits more capillaries leading to an increase in surface area for exchange and oxygen transport to tissues. To do so, we simultaneously measured degrees of tissue hypoxia and vessel perfusion. Pimonidazol was injected intraperitoneally 1 h before sacrifice and capillary patency was assessed by fluorescein isothiocyanate-labeled Lycopersicon esculentum lectin bound to the endothelial surface. Treatment with cilostazol markedly increased the capillary patency which was accompanied by a reduction in the hypoxic area. Although the treatment with cilostazol caused an increase in the flux of plasma proteins across endothelial barrier that may imply an adverse role after a BCCA occlusion, this increase in protein leakage was attributable to the increased surface area for exchange which in turn brought about a reduction in tissue hypoxia. Taken together cilostazol appears to produce a protective effect against the ischemic-reperfusion injury.

  10. Deficiency in the inner mitochondrial membrane peptidase 2-like (Immp21) gene increases ischemic brain damage and impairs mitochondrial function

    PubMed Central

    Ma, Yi; Mehta, Suresh L.; Lu, Baisong; Andy Li, P.

    2011-01-01

    Mitochondrial dysfunction plays an important role in mediating ischemic brain damage. Immp2l is an inner mitochondrial membrane peptidase that processes mitochondrial proteins cytochrome c1 (Cyc1). Homozygous mutation of Immp2l (Immp2lTg(Tyr)979Ove or Immp2l−/−) elevates mitochondrial membrane potential, increases superoxide (•O2−) production in the brain and impairs fertility. The objectives of this study are to explore the effects of heterozygous mutation of lmmp2l (Immp2l+/−) on ischemic outcome and to determine the influence of Immp2l deficiency on brain mitochondria after stroke. Male Immp2l+/− and wild-type (WT) mice were subjected to 1-h focal cerebral ischemia. Their brains were harvested after 5 and 24-h of reperfusion. The results showed that infarct volume and DNA oxidative damage significantly increased in the Immp2l+/− mice. There were no obvious cerebral vasculature abnormalities between the two types of mice viewed by Indian ink perfusion. The increased damage in Immp2l+/− mice was associated with early increase in •O2− production. Mitochondrial respiratory rate, total mitochondrial respiratory capacity and mitochondrial respiratory complex activities were decreased at 5-h of recirculation in Immp2l+/− mice compared to WT mice. Our results suggest that lmmp2l deficiency increases ischemic brain damage by enhancing •O2− production and damaging mitochondrial functional performance. PMID:21824519

  11. A limited role for regulatory T cells in post-ischemic neovascularization.

    PubMed

    Hellingman, A A; van der Vlugt, L E P M; Lijkwan, M A; Bastiaansen, A J N M; Sparwasser, T; Smits, H H; Hamming, J F; Quax, P H A

    2012-02-01

    Recently, it was demonstrated that arteriogenesis is enhanced in mice deficient in regulatory T cells (CD4(+) CD25(+) FoxP3(+) T cell), which can suppress effector T cell responses. The present study investigates the effects of these regulatory T cells on arteriogenesis in more detail by either specific expanding or depleting regulatory T cells. Hind limb ischemia was induced by electro-coagulation of the femoral artery in mice. Regulatory T cells were either expanded by injecting mice with a complex of interleukin (IL)-2 with the IL-2 monoclonal antibody JES6-1, or depleted by anti-CD25 antibody or diphtheria toxin injections in DEREG mice (depletion of regulatory T cells). Blood flow restoration was monitored using laser Doppler perfusion imaging. Collateral arteries were visualized by immunohistochemistry. Regulatory T cell expansion led to a moderate though significant suppression of blood flow restoration after ischemia induction. Surprisingly, depletion of regulatory T cells resulted in minor increase on blood flow recovery. However, collateral and capillary densities in the post-ischemic skeletal muscle were significantly increased in DEREG mice depleted for regulatory T cells. The presence of regulatory T cells after ischemia induction when analysed in non-depleted DEREG mice could be demonstrated by green fluorescent protein staining only in lymph nodes in the ischemic area, and not in the ischemic muscle tissue. The current study demonstrates that, even under conditions of major changes in regulatory T cell content, the contribution of regulatory T cells to the regulation of the arteriogenic response is only moderate. PMID:21426486

  12. A limited role for regulatory T cells in post-ischemic neovascularization

    PubMed Central

    Hellingman, AA; van der Vlugt, LEPM; Lijkwan, MA; Bastiaansen, AJNM; Sparwasser, T; Smits, HH; Hamming, JF; Quax, PHA

    2012-01-01

    Abstract Recently, it was demonstrated that arteriogenesis is enhanced in mice deficient in regulatory T cells (CD4+CD25+FoxP3+ T cell), which can suppress effector T cell responses. The present study investigates the effects of these regulatory T cells on arteriogenesis in more detail by either specific expanding or depleting regulatory T cells. Hind limb ischemia was induced by electro-coagulation of the femoral artery in mice. Regulatory T cells were either expanded by injecting mice with a complex of interleukin (IL)-2 with the IL-2 monoclonal antibody JES6–1, or depleted by anti-CD25 antibody or diphtheria toxin injections in DEREG mice (depletion of regulatory T cells). Blood flow restoration was monitored using laser Doppler perfusion imaging. Collateral arteries were visualized by immunohistochemistry. Regulatory T cell expansion led to a moderate though significant suppression of blood flow restoration after ischemia induction. Surprisingly, depletion of regulatory T cells resulted in minor increase on blood flow recovery. However, collateral and capillary densities in the post-ischemic skeletal muscle were significantly increased in DEREG mice depleted for regulatory T cells. The presence of regulatory T cells after ischemia induction when analysed in non-depleted DEREG mice could be demonstrated by green fluorescent protein staining only in lymph nodes in the ischemic area, and not in the ischemic muscle tissue. The current study demonstrates that, even under conditions of major changes in regulatory T cell content, the contribution of regulatory T cells to the regulation of the arteriogenic response is only moderate. PMID:21426486

  13. A limited role for regulatory T cells in post-ischemic neovascularization.

    PubMed

    Hellingman, A A; van der Vlugt, L E P M; Lijkwan, M A; Bastiaansen, A J N M; Sparwasser, T; Smits, H H; Hamming, J F; Quax, P H A

    2012-02-01

    Recently, it was demonstrated that arteriogenesis is enhanced in mice deficient in regulatory T cells (CD4(+) CD25(+) FoxP3(+) T cell), which can suppress effector T cell responses. The present study investigates the effects of these regulatory T cells on arteriogenesis in more detail by either specific expanding or depleting regulatory T cells. Hind limb ischemia was induced by electro-coagulation of the femoral artery in mice. Regulatory T cells were either expanded by injecting mice with a complex of interleukin (IL)-2 with the IL-2 monoclonal antibody JES6-1, or depleted by anti-CD25 antibody or diphtheria toxin injections in DEREG mice (depletion of regulatory T cells). Blood flow restoration was monitored using laser Doppler perfusion imaging. Collateral arteries were visualized by immunohistochemistry. Regulatory T cell expansion led to a moderate though significant suppression of blood flow restoration after ischemia induction. Surprisingly, depletion of regulatory T cells resulted in minor increase on blood flow recovery. However, collateral and capillary densities in the post-ischemic skeletal muscle were significantly increased in DEREG mice depleted for regulatory T cells. The presence of regulatory T cells after ischemia induction when analysed in non-depleted DEREG mice could be demonstrated by green fluorescent protein staining only in lymph nodes in the ischemic area, and not in the ischemic muscle tissue. The current study demonstrates that, even under conditions of major changes in regulatory T cell content, the contribution of regulatory T cells to the regulation of the arteriogenic response is only moderate.

  14. Illicit Trafficking of Natural Radionuclides

    SciTech Connect

    Friedrich, Steinhaeusler; Lyudmila, Zaitseva

    2008-08-07

    Natural radionuclides have been subject to trafficking worldwide, involving natural uranium ore (U 238), processed uranium (yellow cake), low enriched uranium (<20% U 235) or highly enriched uranium (>20% U 235), radium (Ra 226), polonium (Po 210), and natural thorium ore (Th 232). An important prerequisite to successful illicit trafficking activities is access to a suitable logistical infrastructure enabling an undercover shipment of radioactive materials and, in case of trafficking natural uranium or thorium ore, capable of transporting large volumes of material. Covert en route diversion of an authorised uranium transport, together with covert diversion of uranium concentrate from an operating or closed uranium mines or mills, are subject of case studies. Such cases, involving Israel, Iran, Pakistan and Libya, have been analyzed in terms of international actors involved and methods deployed. Using international incident data contained in the Database on Nuclear Smuggling, Theft and Orphan Radiation Sources (DSTO) and international experience gained from the fight against drug trafficking, a generic Trafficking Pathway Model (TPM) is developed for trafficking of natural radionuclides. The TPM covers the complete trafficking cycle, ranging from material diversion, covert material transport, material concealment, and all associated operational procedures. The model subdivides the trafficking cycle into five phases: (1) Material diversion by insider(s) or initiation by outsider(s); (2) Covert transport; (3) Material brokerage; (4) Material sale; (5) Material delivery. An Action Plan is recommended, addressing the strengthening of the national infrastructure for material protection and accounting, development of higher standards of good governance, and needs for improving the control system deployed by customs, border guards and security forces.

  15. Illicit Trafficking of Natural Radionuclides

    NASA Astrophysics Data System (ADS)

    Friedrich, Steinhäusler; Lyudmila, Zaitseva

    2008-08-01

    Natural radionuclides have been subject to trafficking worldwide, involving natural uranium ore (U 238), processed uranium (yellow cake), low enriched uranium (<20% U 235) or highly enriched uranium (>20% U 235), radium (Ra 226), polonium (Po 210), and natural thorium ore (Th 232). An important prerequisite to successful illicit trafficking activities is access to a suitable logistical infrastructure enabling an undercover shipment of radioactive materials and, in case of trafficking natural uranium or thorium ore, capable of transporting large volumes of material. Covert en route diversion of an authorised uranium transport, together with covert diversion of uranium concentrate from an operating or closed uranium mines or mills, are subject of case studies. Such cases, involving Israel, Iran, Pakistan and Libya, have been analyzed in terms of international actors involved and methods deployed. Using international incident data contained in the Database on Nuclear Smuggling, Theft and Orphan Radiation Sources (DSTO) and international experience gained from the fight against drug trafficking, a generic Trafficking Pathway Model (TPM) is developed for trafficking of natural radionuclides. The TPM covers the complete trafficking cycle, ranging from material diversion, covert material transport, material concealment, and all associated operational procedures. The model subdivides the trafficking cycle into five phases: (1) Material diversion by insider(s) or initiation by outsider(s); (2) Covert transport; (3) Material brokerage; (4) Material sale; (5) Material delivery. An Action Plan is recommended, addressing the strengthening of the national infrastructure for material protection and accounting, development of higher standards of good governance, and needs for improving the control system deployed by customs, border guards and security forces.

  16. Targeted Radionuclide Therapy of Melanoma.

    PubMed

    Norain, Abdullah; Dadachova, Ekaterina

    2016-05-01

    An estimated 60,000 individuals in the United States and 132,000 worldwide are yearly diagnosed with melanoma. Until recently, treatment options for patients with stages III-IV metastatic disease were limited and offered marginal, if any, improvement in overall survival. The situation changed with the introduction of B-RAF inhibitors and anti-cytotoxic T-lymphocyte antigen 4 and anti-programmed cell death protein 1 immunotherapies into the clinical practice. With only some patients responding well to the immune therapies and with very serious side effects and high costs of immunotherapy, there is still room for other approaches for the treatment of metastatic melanoma. Targeted radionuclide therapy of melanoma could be divided into the domains of radioimmunotherapy (RIT), radiolabeled peptides, and radiolabeled small molecules. RIT of melanoma is currently experiencing a renaissance with the clinical trials of alpha-emitter (213)Bi-labeled and beta-emitter (188)Rhenium-labeled monoclonal antibodies in patients with metastatic melanoma producing encouraging results. The investigation of the mechanism of efficacy of melanoma RIT points at killing of melanoma stem cells by RIT and involvement of immune system such as complement-dependent cytotoxicity. The domain of radiolabeled peptides for targeted melanoma therapy has been preclinical so far, with work concentrated on radiolabeled peptide analogues of melanocyte-stimulating hormone receptor and on melanin-binding peptides. The field of radiolabeled small molecule produced radioiodinated benzamides that cross the cellular membrane and bind to the intracellular melanin. The recent clinical trial demonstrated measurable antitumor effects and no acute or midterm toxicities. We are hopeful that the targeted radionuclide therapy of metastatic melanoma would become a clinical reality as a stand-alone therapy or in combination with the immunotherapies such as anti-PD1 programmed cell death protein 1 monoclonal antibodies

  17. An alternative method for neonatal cerebro-myocardial perfusion.

    PubMed

    Luciani, Giovanni Battista; De Rita, Fabrizio; Faggian, Giuseppe; Mazzucco, Alessandro

    2012-05-01

    Several techniques have already been described for selective cerebral perfusion during repair of aortic arch pathology in children. One method combining cerebral with myocardial perfusion has also been proposed. A novel technique is reported here for selective and independent cerebro-myocardial perfusion for neonatal and infant arch surgery. Technical aspects and potential advantages are discussed.

  18. Role of hypothermic machine perfusion in liver transplantation.

    PubMed

    Schlegel, Andrea; Dutkowski, Philipp

    2015-06-01

    Machine liver perfusion has significantly evolved during the last ten years to optimize extended criteria liver grafts and to address the worldwide organ shortage. This review gives an overview on available ex vivo and in vivo data on hypothermic machine liver perfusion. We discuss also possible protective pathways and show most recent clinical applications of hypothermic machine liver perfusion in human.

  19. Robust Low-dose CT Perfusion Deconvolution via Tensor Total-Variation Regularization

    PubMed Central

    Zhang, Shaoting; Chen, Tsuhan; Sanelli, Pina C.

    2016-01-01

    Acute brain diseases such as acute strokes and transit ischemic attacks are the leading causes of mortality and morbidity worldwide, responsible for 9% of total death every year. ‘Time is brain’ is a widely accepted concept in acute cerebrovascular disease treatment. Efficient and accurate computational framework for hemodynamic parameters estimation can save critical time for thrombolytic therapy. Meanwhile the high level of accumulated radiation dosage due to continuous image acquisition in CT perfusion (CTP) raised concerns on patient safety and public health. However, low-radiation leads to increased noise and artifacts which require more sophisticated and time-consuming algorithms for robust estimation. In this paper, we focus on developing a robust and efficient framework to accurately estimate the perfusion parameters at low radiation dosage. Specifically, we present a tensor total-variation (TTV) technique which fuses the spatial correlation of the vascular structure and the temporal continuation of the blood signal flow. An efficient algorithm is proposed to find the solution with fast convergence and reduced computational complexity. Extensive evaluations are carried out in terms of sensitivity to noise levels, estimation accuracy, contrast preservation, and performed on digital perfusion phantom estimation, as well as in-vivo clinical subjects. Our framework reduces the necessary radiation dose to only 8% of the original level and outperforms the state-of-art algorithms with peak signal-to-noise ratio improved by 32%. It reduces the oscillation in the residue functions, corrects over-estimation of cerebral blood flow (CBF) and under-estimation of mean transit time (MTT), and maintains the distinction between the deficit and normal regions. PMID:25706579

  20. An overview of antithrombotics in ischemic stroke.

    PubMed

    Schweickert, Patricia A; Gaughen, John R; Kreitel, Elizabeth M; Shephard, Timothy J; Solenski, Nina J; Jensen, Mary E

    2016-06-19

    The use of antithrombotic medications is an important component of ischemic stroke treatment and prevention. This article reviews the evidence for best practices for antithrombotic use in stroke with focused discussion on the specific agents used to treat and prevent stroke. PMID:27153001

  1. Gene Therapy For Ischemic Heart Disease

    PubMed Central

    Lavu, Madhav; Gundewar, Susheel; Lefer, David J.

    2010-01-01

    Current pharmacologic therapy for ischemic heart disease suffers multiple limitations such as compliance issues and side effects of medications. Revascularization procedures often end with need for repeat procedures. Patients remain symptomatic despite maximal medical therapy. Gene therapy offers an attractive alternative to current pharmacologic therapies and may be beneficial in refractory disease. Gene therapy with isoforms of growth factors such as VEGF, FGF and HGF induces angiogenesis, decreases apoptosis and leads to protection in the ischemic heart. Stem cell therapy augmented with gene therapy used for myogenesis has proven to be beneficial in numerous animal models of myocardial ischemia. Gene therapy coding for antioxidants, eNOS, HSP, mitogen-activated protein kinase and numerous other anti apoptotic proteins have demonstrated significant cardioprotection in animal models. Clinical trials have demonstrated safety in humans apart from symptomatic and objective improvements in cardiac function. Current research efforts are aimed at refining various gene transfection techniques and regulation of gene expression in vivo in the heart and circulation to improve clinical outcomes in patients that suffer from ischemic heart disease. In this review article we will attempt to summarize the current state of both preclinical and clinical studies of gene therapy to combat myocardial ischemic disease. PMID:20600100

  2. Systemic corticosteroids in nonarteritic ischemic optic neuropathy

    PubMed Central

    Al-Zubidi, Nagham; Zhang, Jason; Spitze, Arielle; Lee, Andrew G

    2014-01-01

    Nonarteritic ischemic optic neuropathy (NAION) is one of the most prevalent optic nerve disorders seen in ophthalmic practice. The role of corticosteroid therapy in NAION remains a highly controversial area of debate in ophthalmology. This brief review will provide an overview of the current clinical evidence on this topic as well as some comment on the medical debate. PMID:25449939

  3. Is oxidative stress primarily involved in reperfusion injury of the ischemic heart

    SciTech Connect

    Nohl, H.; Stolze, K.; Napetschnig, S.; Ishikawa, T. )

    1991-01-01

    Reperfusion injury of ischemic organs is suggested to result from metabolic derangements initiating an imbalanced formation of free oxygen radicals. Most investigators in this field have used the spin-trap 5,5'-dimethyl-N-pyrroline-N-oxide (DMPO) to stabilize these short-lived radicals and make them visible by means of the electron spin resonance (ESR) technique. ESR signals obtained from intravascular DMPO were reported to indicate the formation of free OH. radicals and, in some cases, also carbon-centered radicals. We were unable to confirm these findings. Carbon-centered radicals were not obtained irrespectively of conditions studied, while oxygen-centered DMPO-adducts could only be detected in minor amounts. Instead, we observed an ascorbyl-related ESR signal. The addition of ethylenediaminetetraacetic acid (EDTA), which was used by many investigators in this field, was found to greatly influence ESR-spectra of the reperfusion fluid. The ascorbyl radical concentration was clearly reduced and the DMPO-OH. adduct became more prominent. The addition of iron further stimulated this change eliciting a Fenton-type reaction responsible for DMPO-OH.-related ESR spectra in the perfusate after ischemia. Accordingly, we observed the release of iron and ascorbic acid into the perfusate as a consequence of ischemia. We could demonstrate that iron in the presence of ascorbate and EDTA causes both types of radicals detected in the perfusate. DMPO-OH. generation in the presence of EDTA was found to result from free OH. radicals that were not generated in the absence of EDTA.

  4. Asynchronicity of facial blood perfusion in migraine.

    PubMed

    Zaproudina, Nina; Teplov, Victor; Nippolainen, Ervin; Lipponen, Jukka A; Kamshilin, Alexei A; Närhi, Matti; Karjalainen, Pasi A; Giniatullin, Rashid

    2013-01-01

    Asymmetrical changes in blood perfusion and asynchronous blood supply to head tissues likely contribute to migraine pathophysiology. Imaging was widely used in order to understand hemodynamic variations in migraine. However, mapping of blood pulsations in the face of migraineurs has not been performed so far. We used the Blood Pulsation Imaging (BPI) technique, which was recently developed in our group, to establish whether 2D-imaging of blood pulsations parameters can reveal new biomarkers of migraine. BPI characteristics were measured in migraineurs during the attack-free interval and compared to healthy subjects with and without a family history of migraine. We found a novel phenomenon of transverse waves of facial blood perfusion in migraineurs in contrast to healthy subjects who showed synchronous blood delivery to both sides of the face. Moreover, the amplitude of blood pulsations was symmetrically distributed over the face of healthy subjects, but asymmetrically in migraineurs and subjects with a family history of migraine. In the migraine patients we found a remarkable correlation between the side of unilateral headache and the direction of the blood perfusion wave. Our data suggest that migraine is associated with lateralization of blood perfusion and asynchronous blood pulsations in the facial area, which could be due to essential dysfunction of the autonomic vascular control in the face. These findings may further enhance our understanding of migraine pathophysiology and suggest new easily available biomarkers of this pathology. PMID:24324592

  5. Simplified prototyping of perfusable polystyrene microfluidics

    PubMed Central

    Tran, Reginald; Ahn, Byungwook; R. Myers, David; Qiu, Yongzhi; Sakurai, Yumiko; Moot, Robert; Mihevc, Emma; Trent Spencer, H.; Doering, Christopher; A. Lam, Wilbur

    2014-01-01

    Cell culture in microfluidic systems has primarily been conducted in devices comprised of polydimethylsiloxane (PDMS) or other elastomers. As polystyrene (PS) is the most characterized and commonly used substrate material for cell culture, microfluidic cell culture would ideally be conducted in PS-based microsystems that also enable tight control of perfusion and hydrodynamic conditions, which are especially important for culture of vascular cell types. Here, we report a simple method to prototype perfusable PS microfluidics for endothelial cell culture under flow that can be fabricated using standard lithography and wet laboratory equipment to enable stable perfusion at shear stresses up to 300 dyn/cm2 and pumping pressures up to 26 kPa for at least 100 h. This technique can also be extended to fabricate perfusable hybrid PS-PDMS microfluidics of which one application is for increased efficiency of viral transduction in non-adherent suspension cells by leveraging the high surface area to volume ratio of microfluidics and adhesion molecules that are optimized for PS substrates. These biologically compatible microfluidic devices can be made more accessible to biological-based laboratories through the outsourcing of lithography to various available microfluidic foundries. PMID:25379106

  6. Nuclear cardiology: Myocardial perfusion and function

    SciTech Connect

    Seldin, D.W. )

    1991-08-01

    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.

  7. Oxidant stress and damage in post-ischemic mouse hearts: effects of adenosine.

    PubMed

    Hack, Benjamin; Witting, Paul K; Rayner, Benjamin S; Stocker, Roland; Headrick, John P

    2006-07-01

    Despite the general understanding that ischemia-reperfusion (I/R) promotes oxidant stress, specific contributions of oxidant stress or damage to myocardial I/R injury remain poorly defined. Moreover, whether endogenous 'cardioprotectants' such as adenosine act via limiting this oxidant injury is unclear. Herein we characterized effects of 20 min ischemia and 45 min reperfusion on cardiovascular function, oxidative stress and damage in isolated perfused mouse hearts (with glucose or pyruvate as substrate), and examined whether 10 microM adenosine modified these processes. In glucose-perfused hearts post-ischemic contractile function was markedly impaired (< 50% of pre-ischemia), cell damage assessed by lactate dehydrogenase (LDH) release was increased (12 +/- 2 IU/g vs. 0.2 +/- 0.1 IU/g in normoxic hearts), endothelial-dependent dilation in response to ADP was impaired while endothelial-independent dilation in response to nitroprusside was unaltered. Myocardial oxidative stress increased significantly, based on decreased glutathione redox status ([GSSG]/[GSG + GSSH] = 7.8 +/- 0.3% vs. 1.3 +/- 0.1% in normoxic hearts). Tissue cholesterol, native cholesteryl esters (CE) and the lipid-soluble antioxidant alpha-tocopherol (alpha-TOH, the most biologically active form of vitamin E) were unaffected by I/R, whereas markers of primary lipid peroxidation (CE-derived lipid hydroperoxides and hydroxides; CE-O(O)H) increased significantly (14 +/- 2 vs. 2 +/- 1 pmol/mg in normoxic hearts). Myocardial alpha -tocopherylquinone (alpha-TQ; an oxidation product of alpha -TOH) also increased (10.3 +/- 1.0 vs. 1.7 +/- 0.2 pmol/mg in normoxic hearts). Adenosine treatment improved functional recovery and vascular function, and limited LDH efflux. These effects were associated with an anti-oxidant effect of adenosine, as judged by inhibition of I/R-mediated changes in glutathione redox status (by 60%), alpha-TQ (80%) and CE-O(O)H (100%). Provision of 10 mM pyruvate as sole substrate (to

  8. Comparative study of DSC-PWI and 3D-ASL in ischemic stroke patients.

    PubMed

    Zhang, Shui-xia; Yao, Yi-hao; Zhang, Shun; Zhu, Wen-jie; Tang, Xiang-yu; Qin, Yuan-yuan; Zhao, Ling-yun; Liu, Cheng-xia; Zhu, Wen-zhen

    2015-12-01

    The purpose of this study was to quantitatively analyze the relationship between three dimensional arterial spin labeling (3D-ASL) and dynamic susceptibility contrast-enhanced perfusion weighted imaging (DSC-PWI) in ischemic stroke patients. Thirty patients with ischemic stroke were included in this study. All subjects underwent routine magnetic resonance imaging scanning, diffusion weighted imaging (DWI), magnetic resonance angiography (MRA), 3D-ASL and DSC-PWI on a 3.0T MR scanner. Regions of interest (ROIs) were drawn on the cerebral blood flow (CBF) maps (derived from ASL) and multi-parametric DSC perfusion maps, and then, the absolute and relative values of ASL-CBF, DSC-derived CBF, and DSC-derived mean transit time (MTT) were calculated. The relationships between ASL and DSC parameters were analyzed using Pearson's correlation analysis. Receiver operative characteristic (ROC) curves were performed to define the thresholds of relative value of ASL-CBF (rASL) that could best predict DSC-CBF reduction and MTT prolongation. Relative ASL better correlated with CBF and MTT in the anterior circulation with the Pearson correlation coefficients (R) values being 0.611 (P<0.001) and-0.610 (P<0.001) respectively. ROC curves demonstrated that when rASL ≤0.585, the sensitivity, specificity and accuracy for predicting ROIs with rCBF<0.9 were 92.3%, 63.6% and 76.6% respectively. When rASL ≤0.952, the sensitivity, specificity and accuracy for predicting ROIs rMTT>1.0 were 75.7%, 89.2% and 87.8% respectively. ASL-CBF map has better linear correlations with DSC-derived parameters (DSC-CBF and MTT) in anterior circulation in ischemic stroke patients. Additionally, when rASL is lower than 0.585, it could predict DSC-CBF decrease with moderate accuracy. If rASL values range from 0.585 to 0.952, we just speculate the prolonged MTT.

  9. Despite Normal Arteriogenic and Angiogenic Responses, Hindlimb Perfusion Recovery and Necrotic and Fibro-Adipose Tissue Clearance Are Impaired in MMP9 Deficient Mice

    PubMed Central

    Meisner, Joshua K.; Annex, Brian H.; Price, Richard J.

    2014-01-01

    Objective: The relative contributions of arteriogenesis, angiogenesis, and ischemic muscle tissue composition toward reperfusion after arterial occlusion are largely unknown. Differential loss of bone marrow-derived cell (BMC) matrix metalloproteinase 9 (MMP9), which has been implicated in all of these processes, was used to assess the relative contributions of these processes during limb reperfusion. Methods: We compared collateral growth (arteriogenesis), capillary growth (angiogenesis), and ischemic muscle tissue composition after femoral artery ligation in FVB/NJ mice that had been reconstituted with bone marrow from wild-type or MMP9−/− mice. Results: Laser Doppler perfusion imaging confirmed decreased reperfusion capacity in mice with BMC-specific loss of MMP9; however, collateral arteriogenesis was not affected. Furthermore, when accounting for the fact that muscle tissue composition changes markedly with ischemia (i.e. necrotic, fibro-adipose, and regenerating tissue regions are present), angiogenesis was also unaffected. Instead, BMC-specific loss of MMP9 caused an increase in the proportion of necrotic and fibro-adipose tissue, which showed the strongest correlation with poor perfusion recovery. Similarly, the reciprocal loss of MMP9 from non-BMCs showed similar deficits in perfusion and tissue composition without affecting arteriogenesis. Conclusions: By concurrently analyzing arteriogenesis, angiogenesis, and ischemic tissue composition, we determined that the loss of BMC or non- BMC derived MMP9 impairs necrotic and fibro-adipose tissue clearance after femoral artery ligation, despite normal arteriogenic and angiogenic vascular growth. These findings imply that therapeutic revascularization strategies for treating PAD may benefit from additionally targeting necrotic tissue clearance and/or skeletal muscle regeneration. PMID:24582703

  10. Comparing Normothermic Machine Perfusion Preservation With Different Perfusates on Porcine Livers From Donors After Circulatory Death.

    PubMed

    Liu, Q; Nassar, A; Farias, K; Buccini, L; Mangino, M J; Baldwin, W; Bennett, A; O'Rourke, C; Iuppa, G; Soliman, B G; Urcuyo-Llanes, D; Okamoto, T; Uso, T D; Fung, J; Abu-Elmagd, K; Miller, C; Quintini, C

    2016-03-01

    The utilization of normothermic machine perfusion (NMP) may be an effective strategy to resuscitate livers from donation after circulatory death (DCD). There is no consensus regarding the efficacy of different perfusates on graft and bile duct viability. The aim of this study was to compare, in an NMP porcine DCD model, the preservation potential of three different perfusates. Twenty porcine livers with 60 min of warm ischemia were separated into four preservation groups: cold storage (CS), NMP with Steen solution (Steen; XVIVO Perfusion Inc., Denver, CO), Steen plus red blood cells (RBCs), or whole blood (WB). All livers were preserved for 10 h and reperfused to simulate transplantation for 24 h. During preservation, the NMP with Steen group presented the highest hepatocellular injury. At reperfusion, the CS group had the lowest bile production and the worst hepatocellular injury compared with all other groups, followed by NMP with Steen; the Steen plus RBC and WB groups presented the best functional and hepatocellular injury outcomes, with WB livers showing lower aspartate aminotransferase release and a trend toward better results for most parameters. Based on our results, a perfusate that contains an oxygen carrier is most effective in a model of NMP porcine DCD livers compared with Steen solution. Specifically, WB-perfused livers showed a trend toward better outcomes compared with Steen plus RBCs. PMID:26663737

  11. 2009 LANL radionuclide air emissions report

    SciTech Connect

    Fuehne, David P.

    2010-06-01

    The emissions of radionuclides from Department of Energy Facilities such as Los Alamos National Laboratory (LANL) are regulated by the Amendments to the Clean Air Act of 1990, National Emissions Standards for Hazardous Air Pollutants (40 CFR 61 Subpart H). These regulations established an annual dose limit of 10 mrem to the maximally exposed member of the public attributable to emissions of radionuclides. This document describes the emissions of radionuclides from LANL and the dose calculations resulting from these emissions for calendar year 2009. This report meets the reporting requirements established in the regulations.

  12. 2008 LANL radionuclide air emissions report

    SciTech Connect

    Fuehne, David P.

    2009-06-01

    The emissions of radionuclides from Department of Energy Facilities such as Los Alamos National Laboratory (LANL) are regulated by the Amendments to the Clean Air Act of 1990, National Emissions Standards for Hazardous Air Pollutants (40 CFR 61 Subpart H). These regulations established an annual dose limit of 10 mrem to the maximally exposed member of the public attributable to emissions of radionuclides. This document describes the emissions of radionuclides from LANL and the dose calculations resulting from these emissions for calendar year 2008. This report meets the reporting requirements established in the regulations.

  13. 2010 LANL radionuclide air emissions report /

    SciTech Connect

    Fuehne, David P.

    2011-06-01

    The emissions of radionuclides from Department of Energy Facilities such as Los Alamos National Laboratory (LANL) are regulated by the Amendments to the Clean Air Act of 1990, National Emissions Standards for Hazardous Air Pollutants (40 CFR 61 Subpart H). These regulations established an annual dose limit of 10 mrem to the maximally exposed member of the public attributable to emissions of radionuclides. This document describes the emissions of radionuclides from LANL and the dose calculations resulting from these emissions for calendar year 2010. This report meets the reporting requirements established in the regulations.

  14. Conus Medullaris Syndrome following Radionuclide Cisternography.

    PubMed

    Choi, Jay Chol

    2014-01-01

    Radionuclide cisternography is generally considered to be a safe procedure without significant neurological complications. However, in this report we present a patient who developed conus medullaris syndrome following radionuclide cisternography. A 46-year-old woman underwent lumbar puncture followed by radionuclide cisternography with the diagnosis of hydrocephalus. After the cisternography, she developed voiding difficulty with perineal sensory loss. Lumbar MRI revealed a high signal intensity lesion on T2-weighted images at the level of conus medullaris. Considering its clinical course and MRI findings, a spinal cord infarction is highly suggested as a cause of the conus medullaris lesion in this patient.

  15. Bed-side assessment of cerebral perfusion in stroke patients based on optical monitoring of a dye bolus by time-resolved diffuse reflectance.

    PubMed

    Liebert, A; Wabnitz, H; Steinbrink, J; Möller, M; Macdonald, R; Rinneberg, H; Villringer, A; Obrig, H

    2005-01-15

    We present a minimally invasive optical method, that is, multi-channel time-domain diffuse near-infrared reflectometry of the head to assess cerebral blood perfusion that is applicable at the bed-side and repetitively at short intervals. Following intravenous injection of an ICG bolus, its transit through intra- and extracerebral tissue is monitored based on changes in moments of distributions of times of flight of photons, recorded with a 4-channel instrument simultaneously on both hemispheres. In healthy volunteers, we found that variance of distributions of times of flight of photons is well suited to assess latency and initial slope of the increase in absorption of intracerebral tissue due to the bolus. We successfully applied our method in two patients demonstrating a reversible cerebral perfusion deficit in an ischemic stroke patient who was treated by thrombolysis and in another patient with a permanent impaired unilateral perfusion due to ipsilateral internal carotid artery occlusion. In either case, we observed a difference in bolus transit time between the hemispheres. In the stroke patient, this difference resolved when re-evaluated 1 day after thrombolysis. The study demonstrates the necessity of a technique with sub-nanosecond time resolution to allow for depth discrimination if clinical perfusion monitoring of cerebrovascular diseases is addressed by optical methods. PMID:15627584

  16. Prediction of Flow-Limiting Fractional Flow Reserve in Patients With Stable Coronary Artery Disease Based on Quantitative Myocardial Perfusion Imaging.

    PubMed

    Tanaka, Haruki; Takahashi, Teruyuki; Kozono, Nami; Tanakamaru, Yoshiki; Ohashi, Norihiko; Yasunobu, Yuji; Tanaka, Koichi; Okada, Takenori; Kaseda, Shunichi; Nakanishi, Toshio; Kihara, Yasuki

    2016-05-01

    Although fractional flow reserve (FFR) and myocardial perfusion imaging (MPI) findings fundamentally differ, several cohort studies have revealed that these findings correlate. Here, we investigated whether flow-limiting FFR could be predicted from adenosine stress thallium-201 MPI with single-photon emission computed tomography (SPECT) findings derived from 84 consecutive, prospectively identified patients with stable coronary artery disease and 212 diseased vessels. Among them, FFR was measured in 136 diseased vessels (64%). The findings were compared with regional perfusion abnormalities including stress total perfusion defect (TPD) - rest TPD determined using quantitative perfusion single-photon emission computed tomography software. The FFR inversely correlated the most accurately with stress TPD - rest TPD (r = -0.552, p <0.001). Predictors of major vessels of interest comprising FFR <0.80, included stress TPD - rest TPD, the transient ischemic dilation ratio, left ventricular ejection fraction at rest and beta blockers for left anterior descending artery (LAD) regions, and stress TPD - rest TPD, left ventricular mass, left ventricular ejection fraction at rest, right coronary artery lesions, the transient ischemic dilation ratio, and age for non-LAD regions. The diagnostic accuracy of formulas to predict major vessels of interest with FFR <0.80 was high (sensitivity, specificity and accuracy for LAD and non-LAD: 84%, 87% and 86%, and 75%, 93% and 87%, respectively). In conclusion, although somewhat limited by a sample size and a single-center design, flow-limiting FFR could be predicted from MPI findings with a defined probability. A cohort study might validate our results and provide a novel adjunctive tool with which to diagnose functionally significant coronary artery disease from MPI findings. PMID:26970815

  17. Radionuclide angiography for assessment of hyperthyroidism

    SciTech Connect

    Lee, V.W.; Welji, A.N.; Shapiro, J.H.; Angtuaco, E.

    1982-01-01

    A retrospective study of 66 radionuclide angiograms of the thyroid showed that a simple visual inspection of the images is highly accurate for diagnosing hyperthyroidism. Mathematical analysis with computers is not necessary.

  18. Radionuclide carriers for targeting of cancer

    PubMed Central

    Sofou, Stavroula

    2008-01-01

    This review describes strategies for the delivery of therapeutic radionuclides to tumor sites. Therapeutic approaches are summarized in terms of tumor location in the body, and tumor morphology. These determine the radionuclides of choice for suggested targeting ligands, and the type of delivery carriers. This review is not exhaustive in examples of radionuclide carriers for targeted cancer therapy. Our purpose is two-fold: to give an integrated picture of the general strategies and molecular constructs currently explored for the delivery of therapeutic radionuclides, and to identify challenges that need to be addressed. Internal radiotherapies for targeting of cancer are at a very exciting and creative stage. It is expected that the current emphasis on multidisciplinary approaches for exploring such therapeutic directions should enable internal radiotherapy to reach its full potential. PMID:18686778

  19. System and method for assaying a radionuclide

    SciTech Connect

    Cadieux, James R; King, III, George S; Fugate, Glenn A

    2014-12-23

    A system for assaying a radionuclide includes a liquid scintillation detector, an analyzer connected to the liquid scintillation detector, and a delay circuit connected to the analyzer. A gamma detector and a multi-channel analyzer are connected to the delay circuit and the gamma detector. The multi-channel analyzer produces a signal reflective of the radionuclide in the sample. A method for assaying a radionuclide includes selecting a sample, detecting alpha or beta emissions from the sample with a liquid scintillation detector, producing a first signal reflective of the alpha or beta emissions, and delaying the first signal a predetermined time. The method further includes detecting gamma emissions from the sample, producing a second signal reflective of the gamma emissions, and combining the delayed first signal with the second signal to produce a third signal reflective of the radionuclide.

  20. Dosimetry and Case Studies for Selected Radionuclides

    SciTech Connect

    Leggett, Richard Wayne

    2009-01-01

    This is a comprehensive review and analysis of biokinetic and dosimetric information for those radionuclides most likely to be involved in accidental exposures to workers or members of the public or used in radiological terrorism.

  1. Long lived gamma emitting radionuclides in incense.

    PubMed

    Alrefae, Tareq

    2013-10-01

    A study of long-lived gamma emitters in incense was performed. The incense samples originated from seven different countries, and the investigated radionuclides were Ra, Ra, and K. Gamma spectroscopy revealed the presence of all three investigated radionuclides in all samples. Interestingly, the activity concentrations revealed a clear bimodal distribution that distinguished samples that were natural incense from others that were processed incense. The activity concentrations in the latter group were found to be one order of magnitude greater than in the former group. Consequently, the estimated annual effective dose from the latter group was one order of magnitude higher than that of the former group. Nonetheless, the doses from both groups were found to be some three orders of magnitude less than the average worldwide exposure to inhaled natural radionuclides. This finding suggests the radiological safety of incense for the investigated radionuclides.

  2. Cardiac-Specific Deletion of the Pdha1 Gene Sensitizes Heart to Toxicological Actions of Ischemic Stress.

    PubMed

    Sun, Wanqing; Quan, Nanhu; Wang, Lin; Yang, Hui; Chu, Dongyang; Liu, Quan; Zhao, Xuezhong; Leng, Jiyan; Li, Ji

    2016-05-01

    Pyruvate dehydrogenase (PDH) plays a key role in aerobic energy metabolism and occupies a central crossroad between glycolysis and the tricarboxylic acid cycle. We generated inducible cardiac-specific PDH E1α knockout (CreER(T2)-PDH(flox/flox)) mice that demonstrated a high mortality rate. It was hypothesized that PDH modulating cardiac glucose metabolism is crucial for heart functions under normal physiological and/or stress conditions. The myocardial infarction was conducted by a ligation of the left anterior descending coronary arteries. Cardiac PDH E1α deficiency caused large myocardial infarcts size and macrophage infiltration in the hearts (P < .01 vs wild-type [WT]). Wheat germ agglutinin and Masson trichrome staining revealed significantly increased hypertrophy and fibrosis in PDH E1α-deficient hearts (P < .05 vs WT). Measurements of heart substrate metabolism in an ex vivo working heart perfusion system demonstrated a significant impairment of glucose oxidation in PDH E1α-deficient hearts during ischemia/reperfusion (P < .05 vs WT). Dichloroacetate, a PDH activator, increased glucose oxidation in WT hearts during ischemia/reperfusion and reduced myocardial infarct size in WT, but not in PDH E1α-deficient hearts. Immunoblotting results demonstrated that cardiac PDH E1α deficiency leads to an impaired ischemic AMP-activated protein kinase activation through Sestrin2-liver kinase B1 interaction which is responsible for an increased susceptibility of PDH E1α-deficient heart to ischemic insults. Thus, cardiac PDH E1α deficiency impairs ischemic AMP-activated protein kinase signaling and sensitizes hearts to the toxicological actions of ischemic stress.

  3. Radionuclide scintigraphy of bacterial nephritis

    SciTech Connect

    Conway, J.J.; Weiss, S.C.; Shkolnik, A.; Yogev, R.; Firlit, C.; Traisman, E.S.

    1984-01-01

    Pyelonephritis is a leading cause of renal failure and is expected to cost as much as three billion dollars in 1984. The diagnosis of urinary tract infection is usually not difficult. However, localization of the infection within the renal parenchyma as opposed to the collecting system is much more difficult. Flank pain, fever, bacteiuria and evidence of parenchymal involvement by intravenous urography may be absent or unrecognized particularly in the infant. Ultrasound and Nuclear Medicine are advocated as better methods to define parenchymal involvement. Such definition is important in the consideration of treatment since parenchymal involvement of the kidney carries a much more ominous potential outcome than infection restricted to within the collecting system. 38 children with a clinical diagnosis of urinary tract infection were studied. 26 of the patients demonstrated abnormal renal parenchymal findings with Gallium-67 Citrate or Tc-99m Glucoheptonate scintigraphy. Intravenous urography was notably ineffective with only 5 of the 20 interpreted as abnormal due to parenchymal disease or decreased function. 11 were entirely normal while only 5 demonstrated scars or hydronephrosis. Only 10 of 17 patients demonstrated intranvesicoureteral reflux on x-ray or nuclear cystography. Ultrasound depicted 6 of 20 patients as having parenchymal abnormalities. Seven were normal. Nonspecific findings such as dilitation of the renal pelvis or renal enlargement was noted in 11 of the 20 patients. Radionuclide Scintigraphy is the most efficacious modality to detect since acute bacterial nephritis.

  4. Radionuclides in an underground environment

    SciTech Connect

    Thompson, J.L.

    1996-08-01

    In the 100 years since Becquerel recognized radioactivity, mankind has been very successful in producing large amounts of radioactive materials. We have been less successful in reaching a consensus on how to dispose of the billions of curies of fission products and transuranics resulting from nuclear weapons testing, electrical power generation, medical research, and a variety of other human endeavors. Many countries, including the United States, favor underground burial as a means of disposing of radioactive wastes. There are, however, serious questions about how such buried wastes may behave in the underground environment and particularly how they might eventually contaminate water, air and soil resources on which we are dependent. This paper describes research done in the United States in the state of Nevada on the behavior of radioactive materials placed underground. During the last thirty years, a series of ``experiments`` conducted for other purposes (testing of nuclear weapons) have resulted in a wide variety of fission products and actinides being injected in rock strata both above and below the water table. Variables which seem to control the movement of these radionuclides include the physical form (occlusion versus surface deposition), the chemical oxidation state, sorption by mineral phases of the host rock, and the hydrologic properties of the medium. The information gained from these studies should be relevant to planning for remediation of nuclear facilities elsewhere in the world and for long-term storage of nuclear wastes.

  5. Biodecontamination of radionuclide contaminated concrete

    SciTech Connect

    Hamilton, M.A.; Rogers, R.D.; Benson, J.

    1996-10-01

    Within the nuclear industry, there are literally hundreds of square miles of radionuclide contaminated concrete surfaces. A novel technology for biologically decontaminating concrete is being developed. The technology exploits a naturally occurring phenomenon referred to as microbially influenced degradation (MID) in which bacteria produce acids that dissolve the cement matrix of the concrete. Accelerated testing in laboratory conditions was conducted. The bacteria Thiobacillus thiooxidans, supplied from a continuous flow bioreactor, was applied to an exposed concrete surface. A control chamber exposing concrete to sterile media was operated under the same conditions. One hundred percent of surrogate cobalt contamination was recovered from the Thiobacillus treated concrete and 1 mm thickness of concrete material was removed in 60 days. Prototype chambers that can be mounted directly to concrete surfaces have been designed to allow control of environmental conditions to promote MID after inoculation of the surface with bacteria. Studies to determine optimum source and quantity of reduced sulfur, bacterial species or consortia best suited for rapid MID, and methods of application and delivery of bacteria and nutrients will be discussed.

  6. Treatment of radionuclide contaminated soils

    SciTech Connect

    Pettis, S.A.; Kallas, A.J.; Kochen, R.L.; McGlochlin, S.C.

    1988-06-01

    Rockwell, International, Rocky Flats Plants, is committed to remediating within the scope of RCRA/CERCLA, Solid Waste Managements Units (SWMUs) at Rocky Flats found to be contaminated with hazardous substances. SWMUs fund to have radionuclide (uranium, plutonium, and/or americium) concentrations in the soils and/or groundwater that exceed background levels or regulatory limits will also be included in this remediation effort. This paper briefly summarizes past and present efforts by Rockwell International, Rocky Flats Plant, to identify treatment technologies appropriate for remediating actinide contaminated soils. Many of the promising soil treatments evaluated in Rocky Flats' laboratories during the late 1970's and early 1980's are currently being revisited. These technologies are generally directed toward substantially reducing the volume of contaminated soils, with the subsequent intention of disposing of a small remaining concentrated fraction of contaminated soil in a facility approved to receive radioactive wastes. Treatment processes currently will be treated to remove actinides, and recycled back to the process. Past investigations have included evaluations of dry screening, wet screening, scrubbing, ultrasonics, chemical oxidation, calcination, desliming, flotation, and heavy-liquid density separation. 8 refs., 2 figs.

  7. Solubility limits on radionuclide dissolution

    SciTech Connect

    Kerrisk, J.F.

    1984-12-31

    This paper examines the effects of solubility in limiting dissolution rates of a number of important radionuclides from spent fuel and high-level waste. Two simple dissolution models were used for calculations that would be characteristics of a Yucca Mountain repository. A saturation-limited dissolution model, in which the water flowing through the repository is assumed to be saturated with each waste element, is very conservative in that it overestimates dissolution rates. A diffusion-limited dissolution model, in which element-dissolution rates are limited by diffusion of waste elements into water flowing past the waste, is more realistic, but it is subject to some uncertainty at this time. Dissolution rates of some elements (Pu, Am, Sn, Th, Zr, Sm) are always limited by solubility. Dissolution rates of other elements (Cs, Tc, Np, Sr, C, I) are never solubility limited; their release would be limited by dissolution of the bulk waste form. Still other elements (U, Cm, Ni, Ra) show solubility-limited dissolution under some conditions. 9 references, 3 tables.

  8. (Radiological assessments of radionuclide releases)

    SciTech Connect

    Hoffman, F.O.

    1990-12-28

    As a consequence of the Chernobyl accident, data have been obtained throughout the Northern Hemisphere on the concentrations of radionuclides in air, vegetation, soil, water, and foodstuffs that could be important means of human exposure. At the IAEA's invitation, the traveler reviewed recently published data and handbook summaries. The traveler evaluated the need for revising the default values recommended in Chapter 5, Terrestrial and Aquatic Food Chain Transport,'' of IAEA Safety Series No. 57. All attempts at revision were made to keep the mathematical complexity of the models to a minimum without substantial underestimation of dose to critical population subgroups. The traveler also served as chairman of the Multiple Pathways Working Group of the Coordinated Research Program on VAMP. This group has been established to test predictions of models assessing multiple exposure pathways potentially leading to human exposure to {sup 137}Cs. Testing is carried out for major components of assessment models that predict deposition, environmental transport, food chain bioaccumulation, and subsequent uptake and retention in the human body and dose due to exposure to external gamma radiation.

  9. Alchemy with short-lived radionuclides

    SciTech Connect

    Rubio, F.F.; Finn, R.D.; Gilson, A.J.

    1981-04-01

    A variety of short-lived radionuclides are produced and subsequently incorporated into radiopharmaceutical compounds in the radionuclide production program currently being conducted at the Cyclotron Facility of Mount Sinai Medical Center. The recovery of high specific activity oxygen-15 labelled water prepared by means of an inexpensive system operating in conjunction with an on-line radiogas target routinely utilized for oxygen-15 labelled carbon dioxide studies is currently receiving particular attention.

  10. Myocardial metabolism, perfusion, wall motion and electrical activity in Duchenne muscular dystrophy

    SciTech Connect

    Perloff, J.K.; Henze, E.; Schelbert, H.R.

    1982-01-01

    The cardiomyopathy of Duchenne's muscular dystrophy originates in the posterobasal left ventricle and extends chiefly to the contiguous lateral wall. Ultrastructural abnormalities in these regions precede connective tissue replacement. We postulated that a metabolic fault coincided with or antedated the subcellular abnormality. Accordingly, regional left ventricular metabolism, perfusion and wall motion were studied using positron computed tomography and metabolic isotopes supplemented by thallium perfusion scans, equilibrium radionuclide angiography and M-mode and two-dimensional echocardiography. To complete the assessment, electrocardiograms, vectorcardiograms, 24 hour taped electrocardiograms and chest x-rays were analyzed. Positron computed tomography utilizing F-18 2-fluoro 2-deoxyglucose (FDG) provided the first conclusive evidence supporting the hypothesis of a premorphologic regional metabolic fault. Thus, cardiac involvement in duchenne dystrophy emerges as a unique form of heart disease, genetically targeting specific regions of ventricular myocardium for initial metabolic and subcellular changes. Reported ultrastructural abnormalities of the impulse and conduction systems provide, at least in part, a basis for the clinically observed sinus node, intraatrial, internodal, AV nodal and infranodal disorders.

  11. Luminal perfusion of isolated gastric glands.

    PubMed

    Waisbren, S J; Geibel, J; Boron, W F; Modlin, I M

    1994-04-01

    We have extended to rabbit gastric glands the technique for perfusing single isolated renal tubules. We isolated glands by hand dissection and used concentric glass pipettes to hold them and perfuse their lumina. Parietal cells (PCs), which tended to be located toward the gland opening, were identified by their pyramidal shape, large size, and autofluorescence. Chief cells (CCs) were identified by their round shape and smaller size. In some experiments, we perfused the lumen with hydroxypyrenetrisulfonate, a pH-sensitive fluorophore, at pH 7.4 and used digital image processing to monitor luminal pH (pH1). Solutions were buffered with N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid to pH 7.4 at 37 degrees C. With fast perfusion, we found no evidence of decreased pH1, even with stimulation by 10 microM carbachol. With slow perfusion, pH1 often fell below the dye's sensitive range (pH < 5), especially at low perfusate buffering power. In other experiments, we loaded cells with the pH-sensitive dye 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein and monitored intracellular pH (pHi) in multiple individual PCs and CCs in a single gland. Mean pHi was 7.21 +/- 0.02 (n = 136 cells) for PCs and 7.27 +/- 0.03 (n = 103) for CCs. To examine the response to decreased pH1 and basolateral pH (pHb), we lowered pHb to 6.4 or lowered pH1 to 3.4 or 1.4. Lowering pHb to 6.4 for approximately 1 min caused pHi to fall reversibly by 0.39 +/- 0.05 (n = 53) in PCs and 0.58 +/- 0.03 (n = 50) in CCs. Lowering pH1 to 3.4 or 1.4 caused no significant pHi changes in PCs (n = 38 and 82) or in CCs (n = 44 and 77). Carbachol did not affect the response to changes in pH1 or pHb. We conclude that the apical surfaces of PCs and CCs are unusually resistant to extreme pH gradients.

  12. Caffeine intake inverts the effect of adenosine on myocardial perfusion during stress as measured by T1 mapping.

    PubMed

    Kuijpers, Dirkjan; Prakken, Niek H; Vliegenthart, Rozemarijn; van Dijkman, Paul R M; van der Harst, Pim; Oudkerk, Matthijs

    2016-10-01

    Caffeine intake before adenosine stress myocardial perfusion imaging may cause false negative findings. We hypothesized that the antagonistic effect of caffeine can be measured by T1 relaxation times in rest and adenosine stress cardiac magnetic resonance imaging (CMR), as T1 mapping techniques are sensitive to changes in myocardial blood volume. We prospectively analyzed 105 consecutive patients with adenosine stress perfusion CMR on a 1.5-T MRI system. Rest and stress T1 mapping was performed using Modified Look-Locker Inversion recovery. T1 reactivity was defined as difference in T1rest and T1stress (∆T1). Fifteen patients drank coffee within 4 h of CMR (<4H caffeine group), and 10 patients had coffee the day before (>8H caffeine group). Comparison was made to patients without self-reported coffee intake: 50 with normal CMR (control group), 18 with myocardial ischemia, and 12 with myocardial infarction. The national review board approved the study; all patients gave written informed consent. The <4H caffeine group showed inverted ∆T1 of -7.8 % (T1rest 975 ± 42 ms, T1stress 898 ± 51 ms, p < 0.0005). The >8H caffeine group showed reduced T1 reactivity (1.8 %; T1rest 979 ms, T1stress 997 ms) compared to the controls (4.3 %; T1rest 977 ± 40 ms, T1stress 1018 ± 40 ms), p < 0.0005. Ischemic and infarcted myocardium showed minimal T1 reactivity (0.2 and 0.3 %, respectively). Caffeine intake inverts the adenosine effect during stress perfusion CMR as measured by T1 mapping. T1 reactivity can assess the adequacy of adenosine-induced stress in perfusion CMR. PMID:27473274

  13. Real-time cine and myocardial perfusion with treadmill exercise stress cardiovascular magnetic resonance in patients referred for stress SPECT

    PubMed Central

    2010-01-01

    Background To date, stress cardiovascular magnetic resonance (CMR) has relied on pharmacologic agents, and therefore lacked the physiologic information available only with exercise stress. Methods 43 patients age 25 to 81 years underwent a treadmill stress test incorporating both Tc99m SPECT and CMR. After rest Tc99m SPECT imaging, patients underwent resting cine CMR. Patients then underwent in-room exercise stress using a partially modified treadmill. 12-lead ECG monitoring was performed throughout. At peak stress, Tc99m was injected and patients rapidly returned to their prior position in the magnet for post-exercise cine and perfusion imaging. The patient table was pulled out of the magnet for recovery monitoring. The patient was sent back into the magnet for recovery cine and resting perfusion followed by delayed post-gadolinium imaging. Post-CMR, patients went to the adjacent SPECT lab to complete stress nuclear imaging. Each modality's images were reviewed blinded to the other's results. Results Patients completed on average 9.3 ± 2.4 min of the Bruce protocol. Stress cine CMR was completed in 68 ± 14 sec following termination of exercise, and stress perfusion CMR was completed in 88 ± 8 sec. Agreement between SPECT and CMR was moderate (κ = 0.58). Accuracy in eight patients who underwent coronary angiography was 7/8 for CMR and 5/8 for SPECT (p = 0.625). Follow-up at 6 months indicated freedom from cardiovascular events in 29/29 CMR-negative and 33/34 SPECT-negative patients. Conclusions Exercise stress CMR including wall motion and perfusion is feasible in patients with suspected ischemic heart disease. Larger clinical trials are warranted based on the promising results of this pilot study to allow comparative effectiveness studies of this stress imaging system vs. other stress imaging modalities. PMID:20624294

  14. Characterization of bone perfusion by dynamic contrast-enhanced magnetic resonance imaging and positron emission tomography in the Dunkin-Hartley guinea pig model of advanced osteoarthritis.

    PubMed

    Dyke, Jonathan P; Synan, Michael; Ezell, Paula; Ballon, Douglas; Racine, Jennifer; Aaron, Roy K

    2015-03-01

    This study characterizes changes in subchondral bone circulation in OA and examines relationships to bone structure and cartilage degeneration in Dunkin-Hartley guinea pigs. We have used dynamic contrast-enhanced MRI (DCE-MRI) and PET, with pharmacokinetic modeling, to characterize subchondral bone perfusion. Assessments are made of perfusion kinetics and vascular permeability by MRI, and blood volume and flow, and radionuclide incorporation into bone, by PET. These parameters are compared to cartilage lesion severity and bone histomorphometry. Assessments of intraosseous thrombi are made morphologically. Prolonged signal enhancement during the clearance phase of MRI correlated with OA severity and suggested venous stasis. Vascular permeability was not increased indicating that transvascular migration of contrast agent was not responsible for signal enhancement. Intraosseous thrombi were not observed. Decreased perfusion associated with severe OA was confirmed by PET and was associated with reduced radionuclide incorporation and osteoporosis. MRI and PET can be used to characterize kinetic parameters of circulation in OA and correlate them with subchondral bone metabolism of interest to the pathophysiology of OA. The significance of these observations may lie in alterations induced in the expression of cytokines by OA osteoblasts that are related to bone remodeling and cartilage breakdown.

  15. Characterization of Bone Perfusion by Dynamic Contrast-Enhanced Magnetic Resonance Imaging and Positron Emission Tomography in the Dunkin-Hartley Guinea Pig Model of Advanced Osteoarthritis

    PubMed Central

    Dyke, Jonathan P.; Synan, Michael; Ezell, Paula; Ballon, Douglas; Racine, Jennifer; Aaron, Roy K.

    2014-01-01

    Purpose This study characterizes changes in subchondral bone circulation in OA and examines relationships to bone structure and cartilage degeneration in Dunkin-Hartley guinea pigs. Methods We have used dynamic contrast-enhanced MRI (DCE-MRI) and PET, with pharmacokinetic modeling, to characterize subchondral bone perfusion. Assessments are made of perfusion kinetics and vascular permeability by MRI, and blood volume and flow, and radionuclide incorporation into bone, by PET. These parameters are compared to cartilage lesion severity and bone histomorphometry. Assessments of intraosseous thrombi are made morphologically. Results Prolonged signal enhancement during the clearance phase of MRI correlated with OA severity and suggested venous stasis. Vascular permeability was not increased indicating that transvascular migration of contrast agent was not responsible for signal enhancement. Intraosseous thrombi were not observed. Decreased perfusion associated with severe OA was confirmed by PET and was associated with reduced radionuclide incorporation and osteoporosis. Discussion MRI and PET can be used to characterize kinetic parameters of circulation in OA and correlate them with subchondral bone metabolism of interest to the pathophysiology of OA. The significance of these observations may lie in alterations induced in the expression of cytokines by OA osteoblasts that are related to bone remodeling and cartilage breakdown. PMID:25410523

  16. Guidelines for clinical use of cardiac radionuclide imaging, December 1986. A report of the American College of Cardiology/American Heart Association Task Force on Assessment of Cardiovascular Procedures (Subcommittee on Nuclear Imaging).

    PubMed

    1986-12-01

    This report describes the nuclear cardiology procedures available for use as diagnostic techniques in patients with definite or suspected cardiovascular disease. The usefulness of myocardial imaging, radionuclide angiocardiography, and other radionuclide cardiovascular imaging techniques is classified within specific disease states. The clinical utility of each technique is graded from I to IV, depending on the clinical importance of the technique (I equals most important; IV equals not indicated). A grade of V is given for methods now considered to be in their research phase. The usefulness of these methods is discussed in patients with acute ischemic heart disease, chronic ischemic heart disease, valvular heart disease, pulmonary vascular disease, and hypertensive heart disease. Selected references are provided.

  17. AdVEGF-All6A+ Preconditioning of Murine Ischemic Skin Flaps Is Comparable to Surgical Delay

    PubMed Central

    Gersch, Robert P.; Fourman, Mitchell S.; Phillips, Brett T.; Nasser, Ahmed; McClain, Steve A.; Khan, Sami U.; Dagum, Alexander B.

    2015-01-01

    Background: Surgical flap delay is commonly used in preconditioning reconstructive flaps to prevent necrosis. However, staged procedures are not ideal. Pharmacologic up-regulation of angiogenic and arteriogenic factors before flap elevation poses a nonsurgical approach to improve flap survival. Methods: Male Sprague Dawley rats were divided into control (n = 16), surgical delay (Delay), AdNull, AdEgr-1, and AdVEGF (n ≥ 9/group) groups. Delay rats had a 9 cm × 3 cm cranial based pedicle skin flap incised 10 days prior to elevation. Adenoviral groups received 28 intradermal injections (109 pu/animal total) throughout the distal two thirds of the flap 1 week prior to elevation. At postoperative day (POD) 0 flaps were elevated and silicone sheeting was placed between flap and wound bed. Perfusion analysis in arbitrary perfusion units of the ischemic middle third of the flap using laser Doppler imaging was conducted preoperatively and on POD 0, 3, and 7. Clinical and histopathologic assessments of the skin flaps were performed on POD 7. Results: AdVEGF (50.8 ± 10.9 APU) and AdEgr-1 (39.3 ± 10.6 APU) perfusion levels were significantly higher than controls (16.5 ± 4.2 APU) on POD 7. Delay models were equivalent to controls (25.9 ± 6.8 APU). AdVEGF and Delay animals showed significantly more viable surface area on POD 7 (14.4 ± 1.3 cm2, P < 0.01 and 12.4 ± 1.2 cm2, P < 0.05, respectively) compared with Controls (8.7 ± 0.7 cm2). Conclusions: AdVEGF preconditioning resulted in flap survival comparable to surgical delay. Adenoviral preconditioning maintained perfusion levels postoperatively while surgical delay did not. PMID:26495207

  18. Role of thioredoxin-1 in ischemic preconditioning, postconditioning and aged ischemic hearts.

    PubMed

    D'Annunzio, Veronica; Perez, Virginia; Boveris, Alberto; Gelpi, Ricardo J; Poderoso, Juan J

    2016-07-01

    Thioredoxin is one of the most important cellular antioxidant systems known to date, and is responsible of maintaining the reduced state of the intracellular space. Trx-1 is a small cytosolic protein whose transcription is induced by stress. Therefore it is possible that this antioxidant plays a protective role against the oxidative stress caused by an increase of reactive oxygen species concentration, as occurs during the reperfusion after an ischemic episode. However, in addition to its antioxidant properties, it is able to activate other cytoplasmic and nuclear mediators that confer cardioprotection. It is remarkable that Trx-1 also participates in myocardial protection mechanisms such as ischemic preconditioning and postconditioning, activating proteins related to cellular survival. In this sense, it has been shown that Trx-1 inhibition abolished the preconditioning cardioprotective effect, evidenced through apoptosis and infarct size. Furthermore, ischemic postconditioning preserves Trx-1 content at reperfusion, after ischemia. However, comorbidities such as aging can modify this powerful cellular defense leading to decrease cardioprotection. Even ischemic preconditioning and postconditioning protocols performed in aged animal models failed to decrease infarct size. Therefore, the lack of success of antioxidants therapies to treat ischemic heart disease could be solved, at least in part, avoiding the damage of Trx system. PMID:26987940

  19. Aspirin resistant patients with recent ischemic stroke.

    PubMed

    Castilla-Guerra, L; Navas-Alcántara, M S; Fernández-Moreno, M C

    2014-04-01

    Some patients with a recent ischemic stroke who are being treated with aspirin as an antiaggregant suffer a new ischemic stroke. These patients (15-25%) have been called unresponsive to aspirin or aspirin resistant. The aspirin-resistant patients have a four-time greater risk of suffering a stroke. Furthermore, these strokes are generally more severe, with increased infarct volume and greater risk of recurrence. There is currently no ideal laboratory test to detect the resistance to the antiaggregant effect of aspirin. The study of resistance to aspirin would only be indicated in selected cases. In these patients, one should first rule out any "pseudo-resistance" to aspirin (lack of compliance, concomitant treatments that interfere with the action of the aspirin). PMID:24211052

  20. Isolated naratriptan-associated ischemic colitis

    PubMed Central

    Nissan, George; Chaudhry, Priyanka; Rangasamy, Priya; Mudrovich, Steven

    2016-01-01

    We report a 41-year-old woman who developed histology- and colonoscopy-proven ischemic colitis with the use of naratriptan not exceeding the maximum 2 doses a day and 3 days per week and without a known medical or cardiovascular history. By exclusion of other causes of colonic ischemia, naratriptan was considered the sole causal agent. Discontinuation of naratriptan resulted in a complete clinical recovery. To date, our patient is the youngest known patient to develop ischemic colitis on isolated naratriptan in the setting of no known medical risk factors or predisposing medical condition. Even though triptans are commonly used for the abortive treatment of migraine headaches, such a reported side effect is rare; however, careful assessment and individual patient-based treatment is advised.

  1. [Cerebral infarction and transient ischemic attack].

    PubMed

    Sahara, Noriyuki; Kuwashiro, Takahiro; Okada, Yasushi

    2016-04-01

    Japanese Guidelines for the Management of Stroke 2015 was published. Here, we describe several points revised from the 2009 edition about "Cerebral infarction and transient ischemic attack (TIA)". The revision points are as follows; 1. Extension of possible time window of intravenous recombinant tissue-plasminogen activator treatment (from within 3 hours to within 4.5 hours); 2. Antiplatelet therapy in acute stage (dual antiplatelet therapy (DAPT) for non-cardioembolic ischemic stroke or TIA); 3. Endovascular recanalization therapy in acute stage; 4. Antiplatelet therapy in chronic stage (Cilostazol is recommended similar to aspirin or clopidogrel); 5. Non-vitamin K antagonist oral anticoagulants (NOACs) for non-valvular atrial fibrillation (NVAF) stroke or TIA patients; 6. Management of TIA. We explain the revised points of the guideline in the text.

  2. [Ischemic cholangiopathy induced by extended burns].

    PubMed

    Cohen, Laurence; Angot, Emilie; Goria, Odile; Koning, Edith; François, Arnaud; Sabourin, Jean-Christophe

    2013-04-01

    Ischemic cholangiopathy is a recently described entity occurring mainly after hepatic grafts. Very few cases after intensive care unit (ICU) for extended burn injury were reported. We report the case of a 73-year-old woman consulting in an hepatology unit, for a jaundice appearing during a hospitalisation in an intensive care unit and increasing from her leaving from ICU, where she was treated for an extended burn injury. She had no pre-existing biological features of biliary disease. Biological tests were normal. Magnetic resonance imaging acquisitions of biliary tracts pointed out severe stenosing lesions of diffuse cholangiopathy concerning intrahepatic biliary tract, mainly peri-hilar. Biopsie from the liver confirmed the diagnosis, showing a biliary cirrhosis with bile infarcts. This case is the fourth case of ischemic cholangiopathy after extended burn injury, concerning a patient without a prior history of hepatic or biliary illness and appearing after hospitalisation in intensive care unit.

  3. Isolated naratriptan-associated ischemic colitis

    PubMed Central

    Nissan, George; Chaudhry, Priyanka; Rangasamy, Priya; Mudrovich, Steven

    2016-01-01

    We report a 41-year-old woman who developed histology- and colonoscopy-proven ischemic colitis with the use of naratriptan not exceeding the maximum 2 doses a day and 3 days per week and without a known medical or cardiovascular history. By exclusion of other causes of colonic ischemia, naratriptan was considered the sole causal agent. Discontinuation of naratriptan resulted in a complete clinical recovery. To date, our patient is the youngest known patient to develop ischemic colitis on isolated naratriptan in the setting of no known medical risk factors or predisposing medical condition. Even though triptans are commonly used for the abortive treatment of migraine headaches, such a reported side effect is rare; however, careful assessment and individual patient-based treatment is advised. PMID:27695179

  4. [Cerebral infarction and transient ischemic attack].

    PubMed

    Sahara, Noriyuki; Kuwashiro, Takahiro; Okada, Yasushi

    2016-04-01

    Japanese Guidelines for the Management of Stroke 2015 was published. Here, we describe several points revised from the 2009 edition about "Cerebral infarction and transient ischemic attack (TIA)". The revision points are as follows; 1. Extension of possible time window of intravenous recombinant tissue-plasminogen activator treatment (from within 3 hours to within 4.5 hours); 2. Antiplatelet therapy in acute stage (dual antiplatelet therapy (DAPT) for non-cardioembolic ischemic stroke or TIA); 3. Endovascular recanalization therapy in acute stage; 4. Antiplatelet therapy in chronic stage (Cilostazol is recommended similar to aspirin or clopidogrel); 5. Non-vitamin K antagonist oral anticoagulants (NOACs) for non-valvular atrial fibrillation (NVAF) stroke or TIA patients; 6. Management of TIA. We explain the revised points of the guideline in the text. PMID:27333757

  5. Imaging of drug effects in perfused liver

    NASA Astrophysics Data System (ADS)

    Dammann, Marc; Mahlke, Christine; Kessler, Manfred D.

    2002-06-01

    Various medications affect the systemic circulation and organ oxygenation causing dilatation or constriction of blood vessels. Imminent liver failure can be generated by reduced perfusion of different origins. In this case hepatic vasodilatation would be a therapeutical approach for improving patient's condition. Our examinations have been performed in perfused rat liver using spectrometric methods. Two defined areas of the liver were measured punctually. We compared the influence of Tetramethylpyrazine and Glyceroltrinitrate on hemoglobin oxygenation (HbO2) and concentration (Hb-conc.) in rat liver after application of Norepinephrine, which caused a mid decrease in hemoglobin oxygenation of 47,9 %. Both increased the HbO2, but differed from each other in manner of time and extent. Tetramethylpyrazine indicated a longer effect than Glyceroltrinitrate. Furthermore, HbO2 and Hb-conc. showed a conversed relation. From the shape of the absorption spectra it is possible to derive the oxygenation of hemoglobin.

  6. Ischemic Colitis in an Endurance Runner

    PubMed Central

    Grames, Chase; Berry-Cabán, Cristóbal S.

    2012-01-01

    A 20-year-old female running the Marine Corps Marathon developed diarrhea at mile 12. After finishing the race she noted that she was covered in bloody stool. A local emergency department suspected ischemic colitis. After discharge, her primary care physician instructed her to discontinue the use of all nonsteroidal anti-inflammatory drugs. Her symptoms resolved and she returned to running without any complications. This paper describes the pathophysiology, diagnostic approach, and management options. PMID:23091744

  7. The evolution of perfusion education in America.

    PubMed

    Toomasian, John M; Searles, Bruce; Kurusz, Mark

    2003-07-01

    Clinical cardiopulmonary perfusion has evolved significantly during its 50 years. The science, technology and educational processes related to cardiopulmonary bypass have undergone continual change and metamorphosis. Perfusionists were initially trained on the job or in the laboratory, but with the advent of myocardial revascularization and the explosion in cardiac surgery, the need for formal educational training programs became apparent. The American Society of Extracorporeal Technology began the arduous processes of credentialing and developing certification guidelines that have continued under the American Board of Cardiovascular Perfusion. Licensure has also been adopted in many states during the past 10 years where nearly 50% of all perfusionists are covered by some legislative act. One additonal challenge has been developing minimal standards in which perfusionists practice. The initial standards included the use of a checklist and have evolved to monitoring and recording the significant events and parameters of each clinical procedure. The education of perfusionists will continue to be a challenge related primarily to reduced fiscal resources, the applicant pool and the ever-changing demands for extracorporeal circulation services. According to demographic and census information, it is expected the overall number of cardiovascular interventions will increase dramatically towards the latter end of the current decade in the US. The question arises as to what role perfusionists will play, as treatment strategies continue to change. If the number of education programs and new graduates continue to decline, the total number of perfusionists will decline, especially as many senior perfusionists leave the field or retire. It may be difficult to predict the total number of cardiovascular interventions that will be required in the next several years. However, if the total number of cardiovascular interventions that require perfusion services increase as a function

  8. White matter injury in ischemic stroke.

    PubMed

    Wang, Yuan; Liu, Gang; Hong, Dandan; Chen, Fenghua; Ji, Xunming; Cao, Guodong

    2016-06-01

    Stroke is one of the major causes of disability and mortality worldwide. It is well known that ischemic stroke can cause gray matter injury. However, stroke also elicits profound white matter injury, a risk factor for higher stroke incidence and poor neurological outcomes. The majority of damage caused by stroke is located in subcortical regions and, remarkably, white matter occupies nearly half of the average infarct volume. Indeed, white matter is exquisitely vulnerable to ischemia and is often injured more severely than gray matter. Clinical symptoms related to white matter injury include cognitive dysfunction, emotional disorders, sensorimotor impairments, as well as urinary incontinence and pain, all of which are closely associated with destruction and remodeling of white matter connectivity. White matter injury can be noninvasively detected by MRI, which provides a three-dimensional assessment of its morphology, metabolism, and function. There is an urgent need for novel white matter therapies, as currently available strategies are limited to preclinical animal studies. Optimal protection against ischemic stroke will need to encompass the fortification of both gray and white matter. In this review, we discuss white matter injury after ischemic stroke, focusing on clinical features and tools, such as imaging, manifestation, and potential treatments. We also briefly discuss the pathophysiology of WMI and future research directions. PMID:27090751

  9. Endovascular treatment of acute ischemic stroke.

    PubMed

    Leslie-Mazwi, Thabele; Rabinov, James; Hirsch, Joshua A

    2016-01-01

    Endovascular thrombectomy is an effective treatment for major acute ischemic stroke syndromes caused by major anterior circulation artery occlusions (commonly referred to as large vessel occlusion) and is superior to intravenous thrombolysis and medical management. Treatment should occur as quickly as is reasonably possible. All patients with moderate to severe symptoms (National Institutes of Health stroke scale >8) and a treatable occlusion should be considered. The use of neuroimaging is critical to exclude hemorrhage and large ischemic cores. Very shortly after stroke onset (<3 hours) computed tomography (CT) and CT angiography provide sufficient information to proceed; diffusion magnetic resonance imaging (MRI) is less reliable during this early stage. After 3 hours from onset diffusion MRI is the most reliable method to define ischemic core size and should be used in centers that can offer it rapidly. Recanalization is highly effective with a stentriever or using a direct aspiration technique, with the patient awake or under conscious sedation rather than general anesthesia, if it may be performed safely. After thrombectomy the patient should be admitted to an intensive care setting and inpatient rehabilitation undertaken as soon as feasible. Patient outcomes should be assessed at 3 months, preferably using the modified Rankin score. PMID:27430469

  10. White matter injury in ischemic stroke.

    PubMed

    Wang, Yuan; Liu, Gang; Hong, Dandan; Chen, Fenghua; Ji, Xunming; Cao, Guodong

    2016-06-01

    Stroke is one of the major causes of disability and mortality worldwide. It is well known that ischemic stroke can cause gray matter injury. However, stroke also elicits profound white matter injury, a risk factor for higher stroke incidence and poor neurological outcomes. The majority of damage caused by stroke is located in subcortical regions and, remarkably, white matter occupies nearly half of the average infarct volume. Indeed, white matter is exquisitely vulnerable to ischemia and is often injured more severely than gray matter. Clinical symptoms related to white matter injury include cognitive dysfunction, emotional disorders, sensorimotor impairments, as well as urinary incontinence and pain, all of which are closely associated with destruction and remodeling of white matter connectivity. White matter injury can be noninvasively detected by MRI, which provides a three-dimensional assessment of its morphology, metabolism, and function. There is an urgent need for novel white matter therapies, as currently available strategies are limited to preclinical animal studies. Optimal protection against ischemic stroke will need to encompass the fortification of both gray and white matter. In this review, we discuss white matter injury after ischemic stroke, focusing on clinical features and tools, such as imaging, manifestation, and potential treatments. We also briefly discuss the pathophysiology of WMI and future research directions.

  11. Cardioprotection by remote ischemic conditioning: Mechanisms and clinical evidences

    PubMed Central

    Aimo, Alberto; Borrelli, Chiara; Giannoni, Alberto; Pastormerlo, Luigi Emilio; Barison, Andrea; Mirizzi, Gianluca; Emdin, Michele; Passino, Claudio

    2015-01-01

    In remote ischemic conditioning (RIC), several cycles of ischemia and reperfusion render distant organ and tissues more resistant to the ischemia-reperfusion injury. The intermittent ischemia can be applied before the ischemic insult in the target site (remote ischemic preconditioning), during the ischemic insult (remote ischemic perconditioning) or at the onset of reperfusion (remote ischemic postconditioning). The mechanisms of RIC have not been completely defined yet; however, these mechanisms must be represented by the release of humoral mediators and/or the activation of a neural reflex. RIC has been discovered in the heart, and has been arising great enthusiasm in the cardiovascular field. Its efficacy has been evaluated in many clinical trials, which provided controversial results. Our incomplete comprehension of the mechanisms underlying the RIC could be impairing the design of clinical trials and the interpretation of their results. In the present review we summarize current knowledge about RIC pathophysiology and the data about its cardioprotective efficacy. PMID:26516416

  12. Myocardial perfusion imaging with dual energy CT.

    PubMed

    Jin, Kwang Nam; De Cecco, Carlo N; Caruso, Damiano; Tesche, Christian; Spandorfer, Adam; Varga-Szemes, Akos; Schoepf, U Joseph

    2016-10-01

    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.

  13. Inhomogeneity of pulmonary perfusion during sustained microgravity

    NASA Technical Reports Server (NTRS)

    Prisk, G. Kim; Guy, Harold J. B.; Elliott, Ann R.; West, John B.

    1994-01-01

    The effects of gravity on the inhomogeneity of pulmonary perfusion in man were studied by performing hyperventilation-breathhold single-breath measurements before, during and after 9 days of continuous exposure to microgravity. In microgravity the indicators of inhomogeneity of perfusion, especially the size of cardiogenic oscillations in expired CO2 and the height of phase 4, were both markedly reduced. Cardiogenic oscillations were reduced to approximately 60 of their preflight standing size, while the height of phase 4 was between 0 and -8% (a terminal fall became a small terminal rise) of preflights standing. The terminal change in CO2 was nearly abolished in microgravity indicating more uniformity of blood flow between lung units that close at the end of expiration and units that remain open. This may result from the disappearance of gravity-dependent topographical inequality of blood flow. The residual cardiographic oscillations in expired CO2 imply a persisting inhomogeneity of perfusion in the absence of gravity at a level larger than acinar.

  14. Noncontact blood perfusion mapping in clinical applications

    NASA Astrophysics Data System (ADS)

    Iakovlev, Dmitry; Dwyer, Vincent; Hu, Sijung; Silberschmidt, Vadim

    2016-04-01

    Non-contact imaging photoplethysmography (iPPG) to detect pulsatile blood microcirculation in tissue has been selected as a successor to low spatial resolution and slow scanning blood perfusion techniques currently employed by clinicians. The proposed iPPG system employs a novel illumination source constructed of multiple high power LEDs with narrow spectral emission, which are temporally modulated and synchronised with a high performance sCMOS sensor. To ensure spectrum stability and prevent thermal wavelength drift due to junction temperature variations, each LED features a custom-designed thermal management system to effectively dissipate generated heat and auto-adjust current flow. The use of a multi-wavelength approach has resulted in simultaneous microvascular perfusion monitoring at various tissue depths, which is an added benefit for specific clinical applications. A synchronous detection algorithm to extract weak photoplethysmographic pulse-waveforms demonstrated robustness and high efficiency when applied to even small regions of 5 mm2. The experimental results showed evidences that the proposed system could achieve noticeable accuracy in blood perfusion monitoring by creating complex amplitude and phase maps for the tissue under examination.

  15. Perfusion computed tomography in renal cell carcinoma

    PubMed Central

    Das, Chandan J; Thingujam, Usha; Panda, Ananya; Sharma, Sanjay; Gupta, Arun Kumar

    2015-01-01

    Various imaging modalities are available for the diagnosis, staging and response evaluation of patients with renal cell carcinoma (RCC). While contrast enhanced computed tomography (CT) is used as the standard of imaging for size, morphological evaluation and response assessment in RCC, a new functional imaging technique like perfusion CT (pCT), goes down to the molecular level and provides new perspectives in imaging of RCC. pCT depicts regional tumor perfusion and vascular permeability which are indirect parameters of tumor angiogenesis and thereby provides vital information regarding tumor microenvironment. Also response evaluation using pCT may predate the size criteria used in Response Evaluation Criteria in Solid Tumors, as changes in the perfusion occurs earlier following tissue kinase inhibitors before any actual change in size. This may potentially help in predicting prognosis, better selection of therapy and more accurate and better response evaluation in patients with RCC. This article describes the techniques and role of pCT in staging and response assessment in patients with RCCs. PMID:26217456

  16. Regulation of skeletal muscle perfusion during exercise

    NASA Technical Reports Server (NTRS)

    Delp, M. D.; Laughlin, M. H.

    1998-01-01

    For exercise to be sustained, it is essential that adequate blood flow be provided to skeletal muscle. The local vascular control mechanisms involved in regulating muscle perfusion during exercise include metabolic control, endothelium-mediated control, propagated responses, myogenic control, and the muscle pump. The primary determinant of muscle perfusion during sustained exercise is the metabolic rate of the muscle. Metabolites from contracting muscle diffuse to resistance arterioles and act directly to induce vasodilation, or indirectly to inhibit noradrenaline release from sympathetic nerve endings and oppose alpha-adrenoreceptor-mediated vasoconstriction. The vascular endothelium also releases vasodilator substances (e.g., prostacyclin and nitric oxide) that are prominent in establishing basal vascular tone, but these substances do not appear to contribute to the exercise hyperemia in muscle. Endothelial and smooth muscle cells may also be involved in propagating vasodilator signals along arterioles to parent and daughter vessels. Myogenic autoregulation does not appear to be involved in the exercise hyperemia in muscle, but the rhythmic propulsion of blood from skeletal muscle veins facilitates venous return to the heart and muscle perfusion. It appears that the primary determinants of sustained exercise hyperemia in skeletal muscle are metabolic vasodilation and increased vascular conductance via the muscle pump. Additionally, sympathetic neural control is important in regulating muscle blood flow during exercise.

  17. Cellular Basis of Anoxic-Ischemic Brain Injury

    PubMed Central

    Bronshvag, Michael M.

    1978-01-01

    Anoxic-ischemic cerebral disease is an important primary cause of morbidity and mortality, and also complicates a number of systemic diseases. Its clinical manifestations, such as hemiparesis and coma, represent cellular injury sustained by the complex, inhomogeneous brain. An understanding of the nature and pattern of anoxic-ischemic cerebral injury, and of the logical basis for avenues of therapy, is necessary to the management of patients with the various anoxic-ischemic disorders. PMID:685270

  18. Radionuclide scrotal imaging: further experience with 210 patients. Part I. Anatomy, pathophysiology, and methods

    SciTech Connect

    Chen, D.C.P.; Holder, L.E.; Melloul, M.

    1983-08-01

    Ten years' experience with radionuclide scrotal imaging (RSI) to evaluate perfusion of the scrotal contents has confirmed the value of this examination. In 1973, Nadel et al. first proposed using sodium pertechnetate (Tc-99m) to diagnose testicular torsion. By the end of 1982, more than thirty articles have been published on this topic, with most emphasizing the usefulness of RSI in managing patients with acute scrotal pain. The present communication describes our findings in 210 patients, not previously reported. There were four groups with relatively distinct clinical presentations: (a) acute scrotal pain, (b) chronic scrotal pain, (c) scrotal injury, and (d) scrotal mass. The anatomic and pathophysiologic bases for the scan findings will be emphasized. We discuss the staging of testicular torsion; viability of the compromised testicle; variability in the presentation of acute infection; anatomy of trauma, varicocele, and inguinal hernia; and the correlation with scrotal sonography.

  19. A direct comparison of the sensitivity of