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Sample records for mucosal blood perfusion

  1. Mucosal blood flow measurements using laser Doppler perfusion monitoring

    PubMed Central

    Hoff, Dag Arne Lihaug; Gregersen, Hans; Hatlebakk, Jan Gunnar

    2009-01-01

    Perfusion of individual tissues is a basic physiological process that is necessary to sustain oxygenation and nutrition at a cellular level. Ischemia, or the insufficiency of perfusion, is a common mechanism for tissue death or degeneration, and at a lower threshold, a mechanism for the generation of sensory signalling including pain. It is of considerable interest to study perfusion of peripheral abdominal tissues in a variety of circumstances. Microvascular disease of the abdominal organs has been implicated in the pathogenesis of a variety of disorders, including peptic ulcer disease, inflammatory bowel disease and chest pain. The basic principle of laser Doppler perfusion monitoring (LDPM) is to analyze changes in the spectrum of light reflected from tissues as a response to a beam of monochromatic laser light emitted. It reflects the total local microcirculatory blood perfusion, including perfusion in capillaries, arterioles, venules and shunts. During the last 20-25 years, numerous studies have been performed in different parts of the gastrointestinal (GI) tract using LDPM. In recent years we have developed a multi-modal catheter device which includes a laser Doppler probe, with the intent primarily to investigate patients suffering from functional chest pain of presumed oesophageal origin. Preliminary studies show the feasibility of incorporating LDPM into such catheters for performing physiological studies in the GI tract. LDPM has emerged as a research and clinical tool in preference to other methods; but, it is important to be aware of its limitations and account for them when reporting results. PMID:19132770

  2. Enhancement of gastric mucosal blood flow with sulglycotide.

    PubMed

    Guslandi, M; Sorghi, M; Tittobello, A

    1994-01-01

    Twelve patients with dyspepsia whose gastric abnormalities ranged from diffuse reddening of the mucosa to multiple erosions were treated for 4 weeks with oral sulglycotide, a sulphated glycopeptide with known gastroprotective and ulcer-healing properties. Before and after treatment, gastric mucosal blood flow was assessed by means of laser Doppler flowmetry. A significant (P < 0.01) increase in mucosal perfusion was observed after sulglycotide treatment, suggesting that enhancement of mucosal blood flow may contribute to the therapeutic properties of the drug.

  3. Esophageal blood flow in the cat. Normal distribution and effects of acid perfusion

    SciTech Connect

    Hollwarth, M.E.; Smith, M.; Kvietys, P.R.; Granger, D.N.

    1986-03-01

    The radioactive microsphere technique was used to estimate blood flow to different regions of the esophagus and to adjacent regions of the stomach before and after perfusion of the esophagus with hydrochloric acid (pH 1.5) for 5 min. Under resting conditions total blood flow, as well as blood flow to the mucosal-submucosal layer and the muscular layer, to both sphincters was significantly higher than to the esophageal body. Blood flow to the adjacent regions of the stomach was significantly higher than esophageal blood flow. Acid perfusion resulted in a large increase in total blood flow in both sphincters and the lower esophageal body. Gastric blood flow was not altered by acid perfusion. The esophageal hyperemia resulted primarily from an increase in blood flow to the muscular layer; mucosal-submucosal blood flow was increased only in the lower esophageal sphincter. The present study indicates that short periods (5 min) of gastroesophageal reflux may increase esophageal blood flow.

  4. Gastric bicarbonate secretion, acid secretion, and mucosal blood flow during influence of pentagastrin and omeprazole in the cat.

    PubMed

    Guttu, K; Røsok, B; Gislason, H; Fändriks, L; Svanes, K; Grønbech, J E

    1991-04-01

    In this study secretion of bicarbonate and acid and mucosal blood flow were determined simultaneously in cats. The gastric lumen of anesthetized cats was continuously perfused with isotonic saline. Secretion of HCO-3 and H+ was calculated from continuous measurements of pH and PCO2 in the perfusate. Mucosal blood was measured by means of radiolabeled microspheres. Under resting acid secretory conditions, bicarbonate secretion into the gastric lumen averaged 1.0 mumol/min. Somewhat surprising, both omeprazole (4 mg/kg as bolus) and pentagastrin (16 micrograms/kg.h intravenously) significantly reduced the HCO-3 secretion. Omeprazole did not influence mucosal blood flow, whereas corpus mucosal blood flow increased during pentagastrin stimulation. Under resting acid secretory conditions and during omeprazole treatment there was a close linear relationship between acid and bicarbonate secretion. No such relationship was found during pentagastrin stimulation of the mucosa. No consistent relationship was obtained between blood flow and bicarbonate secretion in normal gastric mucosa.

  5. 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.

  6. Asynchronicity of Facial Blood Perfusion in Migraine

    PubMed Central

    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

  7. Dexmedetomidine decreases the oral mucosal blood flow.

    PubMed

    Kawaai, Hiroyoshi; Yoshida, Kenji; Tanaka, Eri; Togami, Kohei; Tada, Hitoshi; Ganzberg, Steven; Yamazaki, Shinya

    2013-12-01

    There is an abundance of blood vessels in the oral cavity, and intraoperative bleeding can disrupt operations. There have been some interesting reports about constriction of vessels in the oral cavity, one of which reported that gingival blood flow in cats is controlled by sympathetic α-adrenergic fibres that are involved with vasoconstriction. Dexmedetomidine is a sedative and analgesic agent that acts through the α-2 adrenoceptor, and is expected to have a vasoconstrictive action in the oral cavity. We have focused on the relation between the effects of α-adrenoceptors by dexmedetomidine and vasoconstriction in oral tissues, and assessed the oral mucosal blood flow during sedation with dexmedetomidine. The subjects comprised 13 healthy male volunteers, sedated with dexmedetomidine in a loading dose of 6 μg/kg/h for 10 min and a continuous infusion of 0.7 μg/kg/h for 32 min. The mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), stroke volume (SV), systemic vascular resistance (SVR), and palatal mucosal blood flow (PMBF) were measured at 0, 5, 10, 12, 22, and 32 min after the start of the infusion. The HR, CO, and PBMF decreased significantly during the infusion even though there were no differences in the SV. The SVR increased significantly but the PMBF decreased significantly. In conclusion, PMBF was reduced by the mediating effect of dexmedetomidine on α-2 adrenoceptors.

  8. Hyperenteroglucagonaemia and small intestinal mucosal growth after colonic perfusion of glucose in rats.

    PubMed Central

    Miazza, B M; Al-Mukhtar, M Y; Salmeron, M; Ghatei, M A; Felce-Dachez, M; Filali, A; Villet, R; Wright, N A; Bloom, S R; Crambaud, J C

    1985-01-01

    Beside intraluminal factors, humoral agents play an important role in intestinal adaptation. Enteroglucagon, the mucosal concentration of which is maximal in the terminal ileum and colon, is the strongest candidate for the role of small intestinal mucosal growth factor. The present experiment was designed to study the role of colonic enteroglucagon in stimulating mucosal growth in rats with a normal small intestine. After eight days of glucose large bowel perfusion, enteroglucagon plasma concentrations were 120.7 +/- SEM 9.2 pmol/l, versus 60.1 +/- 6.8 in mannitol perfused control rats (p less than 0.001). Gastrin, cholecystokinin, neurotensin, pancreatic glucagon, and insulin plasma concentrations were unchanged. Crypt cell proliferation, measured by the vincristine metaphase arrest technique, increased significantly in the small intestine of glucose perfused animals (p less than 0.005-0.001) in comparison with the controls. This resulted in a greater mucosal mass in both proximal and distal small bowel: mucosal wet weight, DNA, protein and alpha D-glucosidase per unit length intestine were all significantly higher (p less than 0.05-0.001) than in mannitol perfused rats. Our data, therefore, support the hypothesis that enteroglucagon is an enterotrophic factor and stress the possible role of the colon in the regulation of small bowel trophicity. PMID:3996942

  9. Fluorescence endoscopic imaging for evaluation of gastric mucosal blood flow: a preliminary study

    NASA Astrophysics Data System (ADS)

    Bocquillon, Nicolas; Mordon, Serge R.; Mathieu, D.; Maunoury, Vincent; Marechal, Xavier-Marie; Neviere, Remi; Wattel, Francis; Chopin, Claude

    1999-02-01

    Microcirculatory disorders of the gastrointestinal tract appear to be a major compound of the multiple organ dysfunction syndrome secondary to sepsis or septic shock. A better analysis of mucosal hypoperfusion in critically ill patients with sepsis may be helpful for the comprehension of this high mortality-associated syndrome. Fluorescence endoscopy has been recognized as a non-invasive method for both spatial and temporal evaluation of gastrointestinal mucosal perfusion. We performed this imaging technique during routine gastric endoscopy in patients with sepsis criteria. The study included gastric observation and appearance time of gastric fluorescence after an intravenous 10% sodium - fluorescein bolus. Qualitative analysis of high fluorescence areas was compared with mucosal blood flow measurements by laser - Doppler flowmetry. We concluded that the fluorescence endoscopic imaging in critically ill patients with sepsis may reveal spacial and temporal differences in the mucosal microcirculation distribution.

  10. The oral mucosal surface and blood vessels

    PubMed Central

    2013-01-01

    Introduction Detailed information about the size of the oral mucosa is scarce in the literature, and those studies that do exist do not take into account the size of the tongue or the enlargement of the surface by the papillae. Because of the various functions of the oral mucosa in the maintenance of oral health, knowledge of its true size may provide a better understanding of the physiology of the oral cavity and some oral diseases and direct future therapeutic strategies. The aim of this study was to determine the total size of the oral mucosa. Methods Five human adult cadaver heads were cut in the median sagittal plane, and the total area of the oral surface was determined using silicon casts. The surface of the tongue was measured with quantitative profilometry. Photographs of oral blood vessels were taken in different areas of the oral mucosa of adult test subjects using intravital microscopy, and the pictures were compared with vessel casts of the oral mucosal capillaries of a maccaca fasciculrais monkey, which was studied using a scanning electron microscope. Results The results showed that the dorsal side of the tongue comprises a large proportion of the total oral mucosal surface. The surface area of the epithelium increases moving from anterior to posterior on the tongue, and the number of underlying blood vessels increases proportionally. Conclusions It can be concluded that the back of the tongue plays an important role in the oral resorption of drugs. Clinical relevance: The results may be of relevance for the delivery and development of oral drug application. PMID:23497446

  11. 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.

  12. 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.

  13. Sensory neurons signal for an increase in rat gastric mucosal blood flow in the face of pending acid injury.

    PubMed

    Holzer, P; Livingston, E H; Guth, P H

    1991-08-01

    Disruption of the gastric mucosal barrier is quickly followed by an increase in gastric mucosal blood flow, which is thought to be a defensive reaction to prevent further injury. This study examined how this increase in blood flow is brought about. When the stomach of urethane-anesthetized rats was perfused with 0.15N HCl, disruption of the gastric mucosal barrier with 15% ethanol increased the disappearance of acid from the gastric lumen and enhanced gastric mucosal blood flow. This increase in blood flow was blocked by local arterial infusion of tetrodotoxin (60 ng/min) to the stomach and by chemical ablation of capsaicin-sensitive sensory neurons. Inhibition of the blood flow increase was associated with exaggeration of gross and histological injury to the mucosa. IV injection of atropine (0.2 mg/kg) or pyrilamine (2 mg/kg) did not affect blood flow increase in response to barrier disruption, whereas morphine injection (2 mg/kg) inhibited it. The current findings show that the increase in gastric mucosal blood flow that follows disruption of the gastric mucosal barrier in the presence of acid is mediated by sensory neurons that seem to monitor acid back-diffusion and in turn signal for a protective increase in blood flow.

  14. Hemangioma of the tongue demonstrating a perfusion blood pool mismatch

    SciTech Connect

    Front, D.; Groshar, D.; Israel, O.; Robinson, E.

    1986-02-01

    Perfusion blood pool mismatch using Tc-99m labeled red blood cells (RBCs) in a hemangioma of the tongue is described. The method is useful in the evaluation of size of the residual blood pool after irradiation of the tumor.

  15. Maintenance of superior mesenteric arterial perfusion prevents increased intestinal mucosal permeability in endotoxic pigs

    SciTech Connect

    Fink, M.P.; Kaups, K.L.; Wang, H.L.; Rothschild, H.R. )

    1991-08-01

    Lipopolysaccharide increases intestinal mucosal permeability to hydrophilic compounds such as chromium 51-labeled edetate (51Cr-EDTA). The authors sought to determine whether this phenomenon is partly mediated by lipopolysaccharide-induced mesenteric hypoperfusion. They assessed permeability in an isolated segment of ileum by measuring plasma-to-lumen clearances (C) for two probes, 51Cr-EDTA and urea, and expressing the results as a ratio (CEDTA/CUREA). In control pigs (n = 6) resuscitated with Ringer's lactate (RL), mucosal permeability was unchanged during the 210-minute period of observation. In pigs (n = 7) infused with lipopolysaccharide (50 micrograms/kg) and similarly resuscitated with RL, mesenteric perfusion (Qsma) decreased significantly and permeability increased progressively and significantly. When endotoxic pigs (n = 6) were resuscitated with a regimen (RL plus hetastarch plus dobutamine) that preserved normal Qsma, lipopolysaccharide-induced mucosal hyperpermeability was prevented. Resuscitation of endotoxic pigs (n = 6) with RL plus hetastarch provided intermediate protection against both mesenteric hypoperfusion and increased permeability. These data suggest that diminished Qsma contributes to impaired ileal mucosal barrier function in experimental endotoxicosis.

  16. Intragastric capsaicin enhances rat gastric acid elimination and mucosal blood flow by afferent nerve stimulation.

    PubMed Central

    Lippe, I. T.; Pabst, M. A.; Holzer, P.

    1989-01-01

    1. This study investigated the effects of intragastric capsaicin on acid output, clearance of aniline, potential difference, and morphology of the mucosa in the rat stomach. The experiments were carried out on rats anaesthetized with urethane in which the stomachs were continuously perfused with saline. 2. When the stomach was perfused with normal saline (pH approximately 6), intragastric capsaicin (32-640 microM) had no effect on the output of titratable acid. In contrast, when acid output was stimulated by pentagastrin or when the stomach was perfused with acid saline (pH 3), capsaicin reduced acid output. Acid loss which occurred during perfusion with saline of pH 2 was not significantly increased by capsaicin. This suggests that capsaicin does not enhance acid back-diffusion but facilitates acid elimination by other means. 3. The gastric clearance of [14C]-aniline, which is an indirect index of gastric mucosal blood flow, was estimated while the stomach was perfused with saline of pH 3. The clearance of aniline rose by 50-60% following intragastric administration of capsaicin (160 microM) whereas the mean arterial blood pressure was increased by about 2.5 mmHg only. Combined pretreatment of the rats with atropine, phentolamine, and propranolol did not alter the effect of capsaicin on the gastric clearance of aniline. 4. The gastric potential difference was not altered by capsaicin (160 microM) administered together with saline of pH 3. This and the finding that there were no signs of mucosal damage by light and scanning electron microscopy indicate that intragastric capsaicin does not irritate the gastric mucosa. 5. The effects of intragastric capsaicin on gastric acid output and aniline clearance and on blood pressure were absent in rats in which capsaicin-sensitive afferent neurones had been ablated by neonatal treatment with a neurotoxic dose of capsaicin, which indicates that they result from stimulation of afferent nerve endings in the stomach. It is

  17. The effect of ice packs upon nasal mucosal blood flow.

    PubMed

    Porter, M; Marais, J; Tolley, N

    1991-01-01

    The effect on nasal mucosal blood flow of ice packs on the forehead and ice packs within the mouth was investigated in 16 healthy subjects. The laser Doppler flowmeter was used to record changes in blood flow to the inferior turbinate, as measured by change in the flux. Ice packs within the mouth produced a significant decrease in nasal mucosal blood flow (p less than 0.05). The average fall was 23% (SEM 5.9) compared with the control measurements. No significant change was recorded following the application of ice packs to the forehead. The results of this study question the scientific rationale behind the use of forehead ice packs in clinical practice.

  18. Regional gastric mucosal blood flow measurements by hydrogen gas clearance in the anesthetized rat and rabbit.

    PubMed

    Leung, F W; Guth, P H; Scremin, O U; Golanska, E M; Kauffman, G L

    1984-07-01

    Hydrogen gas clearance using 3% hydrogen in air and platinum contact electrodes was employed for measuring antral and corpus mucosal blood flow in anesthetized animals. Significantly greater antral than corpus mucosal blood flow was consistently demonstrated. Corpus but not antral mucosal blood flow showed a significant dose-related increase with intravenous pentagastrin. Vasopressin induced a significant dose-related decrease in both antral and corpus mucosal blood flow. Simultaneous measurement of basal corpus mucosal blood flow by hydrogen gas clearance and of gastric mucosal blood flow by aminopyrine clearance gave similar values, but the changes with intravenous pentagastrin or vasopressin measured by aminopyrine clearance were of a much higher order of magnitude. Hydrogen gas clearance, however, reflected changes in left gastric artery blood flow much more closely than did aminopyrine clearance. Therefore, we conclude that the hydrogen gas clearance technique as described is valid for measuring regional gastric mucosal blood flow. It is safe and has potential application in human studies.

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

    PubMed Central

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

    2009-01-01

    Skin blood perfusion and oxygenation depends upon cardiovascular, hormonal and circulatory health in humans and provides socio-sexual signals of underlying physiology, dominance and reproductive status in some primates. We allowed participants to manipulate colour calibrated facial photographs along empirically-measured oxygenated and deoxygenated blood colour axes both separately and simultaneously, to optimise healthy appearance. Participants increased skin blood colour, particularly oxygenated, above basal levels to optimise healthy appearance. We show, therefore, that skin blood perfusion and oxygenation influence perceived health in a way that may be important to mate choice. PMID:19337378

  20. Mucosal adaptation to aspirin induced gastric damage in humans. Studies on blood flow, gastric mucosal growth, and neutrophil activation.

    PubMed Central

    Konturek, J W; Dembinski, A; Stoll, R; Domschke, W; Konturek, S J

    1994-01-01

    The gastropathy associated with the ingestion of non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin is a common side effect of this class of drugs, but the precise mechanisms by which they cause mucosal damage have not been fully explained. During continued use of an injurious substance, such as aspirin, the extent of gastric mucosal damage decreases and this phenomenon is named gastric adaptation. To assess the extent of mucosal damage by aspirin and subsequent adaptation the effects of 14 days of continuous, oral administration of aspirin (2 g per day) to eight healthy male volunteers was studied. To estimate the rate of mucosal damage, gastroscopy was performed before (day 0) and at days 3, 7, 14 of aspirin treatment. Gastric microbleeding and gastric mucosal blood flow were measured using laser Doppler flowmeter and mucosal biopsy specimens were taken for the estimation of tissue DNA synthesis and RNA and DNA concentration. In addition, the activation of neutrophils in peripheral blood was assessed by measuring their ability to associate with platelets. Aspirin induced acute damage mainly in gastric corpus, reaching at day 3 about 3.5 on the endoscopic Lanza score but lessened to about 1.5 at day 14 pointing to the occurrence of gastric adaptation. Mucosal blood flow increased at day 3 by about 50% in the gastric corpus and by 88% in the antrum. The in vitro DNA synthesis and RNA concentration, an index of mucosal growth, were reduced at day 3 but then increased to reach about 150% of initial value at the end of aspirin treatment. It is concluded that the treatment with aspirin in humans induces gastric adaptation to this agent, which entails the increase in mucosal blood flow, the rise in neutrophil activation, and the enhancement in mucosal growth. PMID:7959223

  1. Melatonin pretreatment improves gastric mucosal blood flow and maintains intestinal barrier function during hemorrhagic shock in dogs.

    PubMed

    Vollmer, Christian; Weber, Andreas P M; Wallenfang, Martin; Hoffmann, Till; Mettler-Altmann, Tabea; Truse, Richard; Bauer, Inge; Picker, Olaf; Mathes, Alexander M

    2017-05-01

    Melatonin improves hepatic perfusion after hemorrhagic shock and may reduce stress-induced gastric lesions. This study was designed to investigate whether pretreatment with melatonin may influence gastric mucosal microcirculatory perfusion (μflow), oxygenation (μHbO2 ), or intestinal barrier function during physiological and hemorrhagic conditions in dogs. In a randomized crossover study, five anesthetized foxhounds received melatonin 100 μg kg(-1) or vehicle (ethanol 5%) intravenously in the absence or presence of hemorrhagic shock (60 minutes, -20% blood volume). Systemic hemodynamic variables, gastric mucosal perfusion, and oxygenation were recorded continuously; intestinal barrier function was assessed intermittently via xylose absorption. During hemorrhagic shock, melatonin significantly attenuated the decrease in μflow, compared with vehicle (-19±9 vs -43±10 aU, P<.05), without influence on μHbO2 . A significant increase in xylose absorption was detected during hemorrhage in vehicle-treated dogs, compared with sham-operated animals (13±2 vs 8±1 relative amounts, P<.05); this was absent in melatonin-treated animals (6±1 relative amounts). Melatonin did not influence macrocirculation. Melatonin improves regional blood flow suggesting improved oxygen delivery in gastric mucosa during hemorrhagic shock. This could provide a mechanism for the observed protection of intestinal barrier function in dogs. © 2017 John Wiley & Sons Ltd.

  2. Assessment of differential pulmonary blood flow using perfusion magnetic resonance imaging: comparison with radionuclide perfusion scintigraphy.

    PubMed

    Molinari, Francesco; Fink, Christian; Risse, Frank; Tuengerthal, Siegfried; Bonomo, Lorenzo; Kauczor, Hans-Ulrich

    2006-08-01

    We sought to assess the agreement between lung perfusion ratios calculated from pulmonary perfusion magnetic resonance imaging (MRI) and those calculated from radionuclide (RN) perfusion scintigraphy. A retrospective analysis of MR and RN perfusion scans was conducted in 23 patients (mean age, 60 +/- 14 years) with different lung diseases (lung cancer = 15, chronic obstructive pulmonary disease = 4, cystic fibrosis = 2, and mesothelioma = 2). Pulmonary perfusion was assessed by a time-resolved contrast-enhanced 3D gradient-echo pulse sequence using parallel imaging and view sharing (TR = 1.9 milliseconds; TE = 0.8 milliseconds; parallel imaging acceleration factor = 2; partition thickness = 4 mm; matrix = 256 x 96; in-plane spatial resolution = 1.87 x 3.75 mm; scan time for each 3D dataset = 1.5 seconds), using gadolinium-based contrast agents (injection flow rate = 5 mL/s, dose = 0.1 mmol/kg of body weight). The peak concentration (PC) of the contrast agent bolus, the pulmonary blood flow (PBF), and blood volume (PBV) were computed from the signal-time curves of the lung. Left-to-right ratios of pulmonary perfusion were calculated from the MR parameters and RN counts. The agreement between these ratios was assessed for side prevalence (sign test) and quantitatively (Deming-regression). MR and RN ratios agreed on side prevalence in 21 patients (91%) with PC, in 20 (87%) with PBF, and in 17 (74%) with PBV. The MR estimations of left-to-right perfusion ratios correlated significantly with those of RN perfusion scans (P < 0.01). The correlation was higher using PC (r = 0.67) and PBF (r = 0.66) than using PBV (r = 0.50). The MR ratios computed from PBF showed the highest accuracy, followed by those from PC and PBV. Independently from the MR parameter used, in some patients the quantitative difference between the MR and RN ratios was not negligible. Pulmonary perfusion MRI can be used to assess the differential blood flow of the lung. Further studies in a larger group

  3. Nasal mucosal blood flow after intranasal allergen challenge

    SciTech Connect

    Holmberg, K.; Bake, B.; Pipkorn, U.

    1988-03-01

    The nasal mucosal blood flow in patients with allergic rhinitis was determined at nasal allergen challenges with the /sup 133/Xenon washout method. Determinations were made in 12 subjects before and 15 minutes after challenge with diluent and increasing doses of allergen. The time course was followed in eight subjects by means of repeated measurements during 1 hour after a single allergen dose. Finally, the blood flow was measured after unilateral allergen challenge in the contralateral nasal cavity. A dose-dependent decrease in blood flow was found after nasal challenge with increasing doses of allergens, whereas challenge with diluent alone did not induce any changes. The highest allergen dose, which also induced pronounced nasal symptoms, resulted in a decrease in blood flow of 25% (p less than 0.001). The time-course study demonstrated a maximum decrease in blood flow 10 to 20 minutes after challenge and then a gradual return to baseline. Unilateral allergen challenge resulted in a decrease in blood flow in the contralateral, unchallenged nasal cavity, suggesting that part of the allergen-induced changes in blood flow were reflex mediated.

  4. Endoscopic measurements of gastric mucosal blood flow in dogs.

    PubMed

    Ashley, S W; Yan, Z Y; Soybel, D I; Cheung, L Y

    1985-05-01

    The feasibility and validity of endoscopic measurements of gastric mucosal blood flow (GMBF) using 3% H2 gas clearance were investigated in the intact stomach of anesthetized dogs. Platinum electrodes were lengthened and modified to permit passage through the instrument channel of a standard gastroscope. In five anesthetized dogs, antral mucosal blood flow (103.2 +/- 5.3 ml/min/100 g tissue) was significantly higher (P less than 0.05) than that in the corpus (66.9 +/- 7.1 ml/min/100 g tissue). Histamine stimulation selectively increased flow in the corpus to 134.5 +/- 7.5 ml/min/100 g tissue. Comparison of endoscopic GMBF measurements in these five dogs on 2 different days revealed a close correlation (r = 0.87, P less than 0.001). Endoscopic H2 clearance measurements obtained in five awake dogs were not significantly different from those obtained during pentobarbitol anesthesia. In 12 dogs, GMBF determined by endoscopic H2 gas clearance showed a good agreement (r = 0.91, P less than 0.001) with that measured by radioactive microspheres. These two methods also demonstrated comparable changes in GMBF induced by intravenous infusion of histamine and vasopressin. It was concluded that 3% H2 gas clearance can be used to accurately and reproducibly measure GMBF through the endoscope, a unique advantage of this method for potential clinical use.

  5. Blood-brain barrier permeability imaging using perfusion computed tomography

    PubMed Central

    Avsenik, Jernej; Bisdas, Sotirios; Popovic, Katarina Surlan

    2015-01-01

    Background. The blood-brain barrier represents the selective diffusion barrier at the level of the cerebral microvascular endothelium. Other functions of blood-brain barrier include transport, signaling and osmoregulation. Endothelial cells interact with surrounding astrocytes, pericytes and neurons. These interactions are crucial to the development, structural integrity and function of the cerebral microvascular endothelium. Dysfunctional blood-brain barrier has been associated with pathologies such as acute stroke, tumors, inflammatory and neurodegenerative diseases. Conclusions. Blood-brain barrier permeability can be evaluated in vivo by perfusion computed tomography - an efficient diagnostic method that involves the sequential acquisition of tomographic images during the intravenous administration of iodinated contrast material. The major clinical applications of perfusion computed tomography are in acute stroke and in brain tumor imaging. PMID:26029020

  6. Scaling of cerebral blood perfusion in primates and marsupials.

    PubMed

    Seymour, Roger S; Angove, Sophie E; Snelling, Edward P; Cassey, Phillip

    2015-08-01

    The evolution of primates involved increasing body size, brain size and presumably cognitive ability. Cognition is related to neural activity, metabolic rate and rate of blood flow to the cerebral cortex. These parameters are difficult to quantify in living animals. This study shows that it is possible to determine the rate of cortical brain perfusion from the size of the internal carotid artery foramina in skulls of certain mammals, including haplorrhine primates and diprotodont marsupials. We quantify combined blood flow rate in both internal carotid arteries as a proxy of brain metabolism in 34 species of haplorrhine primates (0.116-145 kg body mass) and compare it to the same analysis for 19 species of diprotodont marsupials (0.014-46 kg). Brain volume is related to body mass by essentially the same exponent of 0.70 in both groups. Flow rate increases with haplorrhine brain volume to the 0.95 power, which is significantly higher than the exponent (0.75) expected for most organs according to 'Kleiber's Law'. By comparison, the exponent is 0.73 in marsupials. Thus, the brain perfusion rate increases with body size and brain size much faster in primates than in marsupials. The trajectory of cerebral perfusion in primates is set by the phylogenetically older groups (New and Old World monkeys, lesser apes) and the phylogenetically younger groups (great apes, including humans) fall near the line, with the highest perfusion. This may be associated with disproportionate increases in cortical surface area and mental capacity in the highly social, larger primates.

  7. Blood perfusion construction for infrared face recognition based on bio-heat transfer.

    PubMed

    Xie, Zhihua; Liu, Guodong

    2014-01-01

    To improve the performance of infrared face recognition for time-lapse data, a new construction of blood perfusion is proposed based on bio-heat transfer. Firstly, by quantifying the blood perfusion based on Pennes equation, the thermal information is converted into blood perfusion rate, which is stable facial biological feature of face image. Then, the separability discriminant criterion in Discrete Cosine Transform (DCT) domain is applied to extract the discriminative features of blood perfusion information. Experimental results demonstrate that the features of blood perfusion are more concentrative and discriminative for recognition than those of thermal information. The infrared face recognition based on the proposed blood perfusion is robust and can achieve better recognition performance compared with other state-of-the-art approaches.

  8. Evaluation of mast cells, eosinophils, blood capillaries in oral lichen planus and oral lichenoid mucositis.

    PubMed

    Reddy, D Santhosh; Sivapathasundharam, B; Saraswathi, T R; SriRam, G

    2012-01-01

    Mast cells are granule containing secretory cells present in oral mucosal and connective tissue environment. Oral lichen planus and oral lichenoid lesions are commonly occurring oral diseases and have some similarity clinically and histologically. Both are characterized by an extensive sub epithelial infiltrate of T cells, together with mast cells, eosinophils and blood capillaries. In this study mast cell and eosinophil densities along with number of blood capillaries were studied to find out if they could aid in histopathological distinction between oral lichen planus and lichenoid mucositis. To enumerate mast cells and compare the status of Mast Cells (Intact or Degranulated) in Lichen planus, Lichenoid mucositis and normal buccal mucosa in tissue sections stained with Toluidine Blue, and also to enumerate Eosinophils and blood capillaries in tissue sections stained with H and E. The study group included 30 cases each of oral lichen planus and oral lichenoid mucositis. 10 cases of clinically normal oral buccal mucosa formed the control group. All the sections were stained with Toluidine blue and H and E separately. Histopathological analysis was done using binocular light microscope equipped with square ocular grid to standardize the field of evaluation. The result of the study showed. · Significant increase in number of mast cells in oral lichen planus and oral lichenoid mucositis compared to normal buccal mucosa. · Significant increase of intact mast cells suepithelially within the inflammatory cell infiltrate in oral lichen planus compared to oral lichenoid mucositis. · Significant increase of degranulated mast cells in oral lichenoid mucositis to oral lichen planus, and increase in number of eosinophil densities in oral lichenoid mucositis compared to oral lichen planus. · Significant increase in number of capillaries in oral lichenoid mucositis compared to oral lichen planus. The findings of increased number of intact mast cells sub epithelially in oral

  9. Nickel-Related Intestinal Mucositis in IBS-Like Patients: Laser Doppler Perfusion Imaging and Oral Mucosa Patch Test in Use.

    PubMed

    Borghini, Raffaele; Puzzono, Marta; Rosato, Edoardo; Di Tola, Marco; Marino, Mariacatia; Greco, Francesca; Picarelli, Antonio

    2016-09-01

    Nickel (Ni) is often the trigger of irritable bowel syndrome (IBS)-like gastrointestinal disorders: its ingestion may cause allergic contact mucositis, identifiable by means of oral mucosa patch test (omPT). OmPT effectiveness has been proven, but it is still an operator-dependent method. Laser Doppler perfusion imaging (LDPI) was tested to support omPT in Ni allergic contact mucositis diagnosis. Group A: 22 patients with intestinal/systemic symptoms related to the ingestion of Ni-containing foods. Group B: 12 asymptomatic volunteers. Ni-related symptoms and their severity were tested by a questionnaire. All patients underwent Ni omPT with clinical evaluation at baseline (T0), after 30 min (T1), after 2 h (T2), and after 24-48 h (T3). LDPI was performed to evaluate the mean mucosal perfusion at T0, T1, and T2. Statistical analysis was performed by ANOVA test and Bonferroni multiple-comparison test. All 22 Ni-sensitive patients (group A) presented oral mucosa hyperemia and/or edema at T2. Eight out of the same 22 patients presented a local delayed vesicular reaction at T3 (group A1), unlike the remaining 14 out of 22 patients (group A2). All 12 patients belonging to control group B did not show any alteration. The mean mucosal perfusion calculated with LDPI showed an increase in both subgroups A1 and A2. In group B, no significant perfusion variations were observed. LDPI may support omPT for diagnostic purposes in Ni allergic contact mucositis. This also applies to symptomatic Ni-sensitive patients without aphthous stomatitis after 24-48 h from omPT and that could risk to miss the diagnosis.

  10. Effects of blood perfusion rate on the optimization of RF-capacitive hyperthermia.

    PubMed

    Fujita, S; Tamazawa, M; Kuroda, K

    1998-09-01

    The effects of the blood perfusion rate on the optimization of heating conditions in radio-frequency capacitive hyperthermia were examined using numerical simulations. When the blood perfusion rate in the tumor was smaller than approximately one-half that of normal tissues, optimal selective heating of the tumor was obtained.

  11. PulseCam: high-resolution blood perfusion imaging using a camera and a pulse oximeter.

    PubMed

    Kumar, Mayank; Suliburk, James; Veeraraghavan, Ashok; Sabharwal, Ashutosh

    2016-08-01

    Measuring blood perfusion is important in medical care as an indicator of injury and disease. However, currently available devices to measure blood perfusion like laser Doppler flowmetry are bulky, expensive, and cumbersome to use. An alternative low-cost and portable camera-based blood perfusion measurement system has recently been proposed, but such camera-only system produces noisy low-resolution blood perfusion maps. In this paper, we propose a new multi-sensor modality, named PulseCam, for measuring blood perfusion by combining a traditional pulse oximeter with a video camera in a unique way to provide low noise and high-resolution blood perfusion maps. Our proposed multi-sensor modality improves per pixel signal to noise ratio of measured perfusion map by up to 3 dB and improves the spatial resolution by 2 - 3 times compared to best known camera-only methods. Blood perfusion measured in the palm using our PulseCam setup during a post-occlusive reactive hyperemia (PORH) test replicates standard PORH response curve measured using laser Doppler flowmetry device but with much lower cost and a portable setup making it suitable for further development as a clinical device.

  12. Retrobulbar blood flow and ophthalmic perfusion in maximum dynamic exercise.

    PubMed

    Kozobolis, Vassilios P; Detorakis, Efstathios T; Konstas, Anastasios G; Achtaropoulos, Athanassios K; Diamandides, Evangelos D

    2008-03-01

    To study the effects of maximum dynamic physical exercise on retrobulbar blood flow and ocular perfusion pressure (OPP). Thirty male subjects undergoing routine periodic medical evaluation were included. All participants underwent cardiac stress test according to a standard protocol. Before the test, the intraocular pressure was measured and colour Doppler imaging was performed with a 7.5 MHz linear probe, to record peak systolic velocity (PSV), end diastolic velocity and resistivity index at the ophthalmic artery (OA), central retinal artery (CRA) and nasal and temporal branches of short posterior ciliary arteries (SPCA). The same measurements were repeated 1 and 30 min after the test. OPP and PSV at the OA were significantly higher at the 1-min interval, compared with the pretest scores (P = 0.01, in both cases), whereas the respective differences on the 30-min interval were statistically not significant. On the contrary, PSV at the CRA and SPCA were not significantly changed on the same intervals. Differences between pretest and post-test scores for end diastolic velocity and resistivity index were statistically not significant for all examined vessels. Maximal physical exercise increases OPP and blood flow at the OA without affecting blood flow at the CRA and SPCA, implying that auto-regulative mechanisms are active in both retinal and choroidal circulations.

  13. Infrared face recognition based on modified blood perfusion model and 2DLDA in DWT domain

    NASA Astrophysics Data System (ADS)

    Wu, Shiqian; Liang, Wei; Fang, Zhijun; Yang, Jucheng; Yuan, Jiasheng

    2009-10-01

    A efficient method for infrared face recognition by modified blood perfusion model of human face and 2DLDA in DWT domain is proposed. Then we demonstrate from the theoretical that the 2DLDA subspace projection result remains the same with the original data are transformed using the wavelet transformation. The experiments conducted illustrate that the method proposed in this paper has better performance. While the recognition rate wasn't decrease based on modified blood perfusion model compared to blood perfusion model obviously and have even lightly improved in some cases.

  14. Blood leakage and melphalan leakage from the perfusion circuit during regional hyperthermic perfusion for malignant melanoma

    SciTech Connect

    Hafstroem, L.; Hugander, A.; Joensson, P.E.; Westling, H.; Ehrsson, H.

    1984-06-01

    In regional hyperthermic perfusion with melphalan for patients with malignant melanoma of the leg, plasma leakage between the perfusion circuit and the systemic circulation was 4-7 ml X min-1. The melphalan concentration in the perfusate was biphasic, with half-lives of 8-12 mins for the initial phase and 19-28 mins for the second phase, after the first dose. After a second dose, the corresponding values were 11-13 and 26-34 mins. The highest concentration in general circulation was 0.38 micrograms X ml-1.

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

    PubMed

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

    2016-01-01

    Victims of severe accidental hypothermia are prone to fluid extravasation but rarely develop lung edema. We hypothesize that combined hypothermia-induced increase in pulmonary vascular resistance (PVR) and a concomitant fall in cardiac output protect the lungs against edema development. Our aim was to explore in hypothermic-isolated blood-perfused rat lungs whether perfusion at constant pressure influences fluid filtration differently from perfusion at constant flow. Isolated blood-perfused rat lungs were hanging freely in a weight transducer for measuring weight changes (ΔW). Fluid filtration coefficient (Kfc), was determined by transiently elevating left atrial pressure (Pla) by 5.8 mmHg two times each during normothermia (37°C) and during hypothermia (15°C). The lung preparations were randomized to two groups. One group was perfused with constant flow (Constant flow group) and the other group with constant pulmonary artery pressure (Constant PPA group). Microvascular pressure (Pmv) was determined before and during elevation of Pla (ΔPmv) by means of the double occlusion technique. Kfc was calculated with the formula Kfc = ΔW/ΔPmv/min. All Kfc values were normalized to predicted lung weight (PLW), which was based on body weight (BW) according to the formula: PLW = 0.0053 BW - 0.48 and presented as KfcPLW in mg/min/mmHg/g. At cessation, bronchoalveolar lavage (BAL) fluid/perfusate protein concentration (B/P) ratio was determined photometrically. Data were analyzed with parametric or non-parametric tests as appropriate. p < 0.05 considered as significant. Perfusate flow remained constant in the Constant flow group, but was more than halved during hypothermia in the Constant PPA group concomitant with a more fold increase in PVR. In the Constant flow group, KfcPLW and B/P ratio increased significantly by more than 10-fold during hypothermia concerted by visible signs of edema in the trachea. Hemoglobin and hematocrit increased within the

  16. Effect of enhanced red blood cell aggregation on blood flow resistance in an isolated-perfused guinea pig heart preparation.

    PubMed

    Yalcin, Ozlem; Meiselman, Herbert J; Armstrong, Jonathan K; Baskurt, Oguz K

    2005-01-01

    The role of red blood cell (RBC) aggregation as a determinant of in vivo blood flow is still unclear. This study was designed to investigate the influence of a well-controlled enhancement of RBC aggregation on blood flow resistance in an isolated-perfused heart preparation. Guinea pig hearts were perfused through a catheter inserted into the root of the aorta using a pressure servo-controlled pump system that maintained perfusion pressures of 30 to 100 mmHg. The hearts were beating at their intrinsic rates and pumping against the perfusion pressure. RBC aggregation was increased by Pluronic (F98) coating of RBC at a concentration 0.025 mg/ml, corresponding to about a 100% increment in RBC aggregation as measured by erythrocyte sedimentation rate. Isolated heart preparations were perfused with 0.40 l/l hematocrit unmodified guinea pig blood and with Pluronic-coated RBC suspensions in autologous plasma. At high perfusion pressures there were no significant differences between the flow resistance values for the two perfusates, with differences in flow resistance only becoming significant at lower perfusion pressures. These results can be interpreted to reflect the shear dependence of RBC aggregation: higher shear forces associated with higher perfusion pressures should have dispersed RBC aggregates resulting in blood flow resistances similar to control values. Experiments repeated in preparations in which the smooth muscle tone was inhibited by pre-treatment with papaverine indicated that significant effects of enhanced RBC aggregation could be detected at higher perfusion pressures, underlining the compensatory role of vasomotor control mechanisms.

  17. Mucosal acid causes gastric mucosal microcirculatory disturbance in nonsteroidal anti-inflammatory drug-treated rats.

    PubMed

    Funatsu, Toshiyuki; Chono, Koji; Hirata, Takuya; Keto, Yoshihiro; Kimoto, Aishi; Sasamata, Masao

    2007-01-05

    The mechanism by which nonsteroidal anti-inflammatory drugs (NSAIDs) suppress gastric mucosal blood flow is not fully understood, although the depletion of mucosal prostaglandin E2 has been proposed as one possible explanation. We investigated the role of gastric acid on gastric mucosal blood flow in NSAID-treated rats. A rat stomach was mounted in an ex vivo chamber, and gastric mucosal blood flow was measured sequentially in a 5-mm2 area of the gastric corpus using a scanning laser Doppler perfusion image system. Results showed that diclofenac (5 mg/kg s.c.) and indomethacin (10 mg/kg s.c.) did not affect gastric mucosal blood flow, although both strongly decreased mucosal prostaglandin E2 when saline was instilled into the gastric chamber. On replacement of the saline in the chamber with 100 mM hydrochloric acid, these drugs caused a decrease in gastric mucosal blood flow levels within 30 min. The specific cyclooxygenase (COX)-2 inhibitors celecoxib (50 mg/kg s.c.) and rofecoxib (25 mg/kg s.c.) did not affect mucosal prostaglandin E2 level, nor did they decrease gastric mucosal blood flow, even when hydrochloric acid was added to the chamber. Furthermore, measurement of vasoconstrictive factors present in the mucosa showed that endothelin-1 levels increased after administration of diclofenac s.c. in the presence of intragastric hydrochloric acid. This indicates that the presence of mucosal hydrochloric acid plays an important role in the NSAID-induced decrease in gastric mucosal blood flow, while the COX-1-derived basal prostaglandin E2, which is unlikely to control gastric mucosal blood flow itself, protects microcirculatory systems from mucosal hydrochloric acid.

  18. Lack of correlation between fecal blood loss and drug-induced gastric mucosal lesions

    SciTech Connect

    Hedenbro, J.L.; Wetterberg, P.; Vallgren, S.; Bergqvist, L.

    1988-05-01

    Increased fecal blood loss was produced in healthy volunteers by the administration of two nonsteroidal anti-inflammatory drugs (NSAID), naproxen or fenflumizole. Basal as well as drug-induced gastrointestinal blood loss was measured using /sup 51/Cr erythrocyte labeling. Median rise in daily fecal blood loss was 432%. All subjects were endoscoped at the initiation and at the completion of the study. Endoscopic findings were assessed quantitatively by two observers in two different ways. All subjects but three had gastric mucosal lesions at follow-up endoscopy. There was a good correlation between the endoscopic assessments but no statistical correlation between the endoscopic assessment and the increase in fecal blood loss. The data suggest that factors other than gastric mucosal lesions have to be taken into account when investigating NSAID-induced gastrointestinal bleeding.

  19. Blood perfusion and pH monitoring in organs by laser-induced fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Vari, Sandor G.; Papazoglou, Theodore G.; Pergadia, Vani R.; Stavridi, Marigo; Snyder, Wendy J.; Papaioannou, Thanassis; Duffy, J. T.; Weiss, Andrew B.; Thomas, Reem; Grundfest, Warren S.

    1994-01-01

    Sensitivity of laser-induced fluorescence spectroscopy (LIFS) in detecting a change in tissue pH, and blood perfusion was determined. Rabbits were anesthetized, paralyzed, and mechanically ventilated. The arterial and venous blood supplies of the kidney were isolated and ligated to alter the perfusion. The femoral artery was cannulated to extract samples for blood gas analysis. A 308-nm XeCl was used as an excitation source. A 600 micrometers core diameter fiber was used for fluorescence acquisition, and the spectra analyzed by an optical multichannel analyzer (EG & G, OMA III). the corresponding intensity ratio R equals INADH / ICOLL was used as an index for respiratory acidosis. Blood perfusion was assessed using the following algorithm: (IELAS minus ICOLL) divided by (INADH minus ICOLL). The intensity ratio linearly decreased with the reduction of blood perfusion. When we totally occluded the artery the ratio decreased tenfold when compared to the ratio of a fully perfused kidney. Results of monitoring blood acidosis by laser-induced fluorescence spectroscopy shows a significant trend between pH and intensity ratio. Since all the slopes were negative, there is an obvious significant correlation between the pH and NADH.COLLAGEN RATIO. Blue-light-induced fluorescence measurements and ratio fluorometry is a sensitive method for monitoring blood perfusion and acidity or alkalinity of an organ.

  20. Role of capsaicin sensitive nerves in epidermal growth factor effects on gastric mucosal injury and blood flow

    PubMed Central

    Kang, J; Teng, C; Chen, F; Wee, A

    1998-01-01

    Background—Epidermal growth factor (EGF) and capsaicin protect against experimental gastric mucosal injury. Capsaicin exerts its gastroprotective effect by stimulating afferent neurones leading to release of calcitonin gene related peptide (CGRP) which causes gastric hyperaemia. EGF also causes gastric hyperaemia but whether it acts via capsaicin sensitive neurones is unknown. 
Aims—To assess the influence of: (1) capsaicin desensitisation on EGF effects on gastric mucosal injury and gastric mucosal blood flow; and (2) close arterial infusion of hCGRP8-37, a CGRP antagonist, on EGF effects on gastric mucosal blood flow. 
Methods—The absolute ethanol induced gastric mucosal injury model in the rat was used. Gastric mucosal damage was assessed by planimetry and light microscopy. Gastric mucosal blood flow was measured by laser Doppler flowmetry in a gastric chamber preparation. 
Results—Capsaicin desensitisation abolished the gastroprotective and gastric hyperaemic effects of EGF. Close arterial infusion of hCGRP8-37 antagonised the hyperaemic effect of both capsaicin and EGF. 
Conclusion—Results show that EGF may exert its gastroprotective and gastric hyperaemic effects via capsaicin sensitive afferent neurones. 

 Keywords: capsaicin; epidermal growth factor; gastric mucosal injury; gastric mucosal blood flow; calcitonin gene related peptide antagonist; rat PMID:9577339

  1. Gastric intramucosal acidosis in mechanically ventilated patients: role of mucosal blood flow.

    PubMed

    Elizalde, J I; Hernández, C; Llach, J; Montón, C; Bordas, J M; Piqué, J M; Torres, A

    1998-05-01

    To investigate whether gastric intramucosal acidosis is associated with a decreased gastric mucosal blood flow in mechanically ventilated patients. Prospective, clinical investigation. University hospital intensive care unit. Seventeen mechanically ventilated patients with stable hemodynamic status. Gastric tonometry and endoscopic assessment of mucosal blood flow. Six patients had gastric intramucosal acidosis (intramucosal pH [pHi] of 7.24 +/- 0.06), whereas the remaining 11 patients had pHi values within the normal range (7.44 +/- 0.01). No differences were found between intramucosal acidotic and nonacidotic patients with respect to their general and hemodynamic characteristics. Patients with intramucosal acidosis had a lower gastric mucosal blood flow, as assessed by laser-Doppler flowmetry, than nonacidotic patients (1.4 +/- 0.1 vs. 2.1 +/- 0.2 volts, respectively; p < .05). Reflectance spectrophotometry disclosed that patients with low gastric pHi had also a significantly (p < .05) lower hemoglobin content index (61 +/- 4 arbitrary units) than patients with normal pHi (81 +/- 3 arbitrary units), whereas oxygen saturation index was similar for both groups. Our results support the hypothesis that gastric mucosal hypoperfusion underlies the development of intramucosal acidosis in mechanically ventilated patients.

  2. Mucosal adaptation to indomethacin induced gastric damage in man--studies on morphology, blood flow, and prostaglandin E2 metabolism.

    PubMed Central

    Shorrock, C J; Rees, W D

    1992-01-01

    The effect of 28 days' continuous administration of oral indomethacin on gastroduodenal morphology, gastric mucosal blood flow, and gastric mucosal prostaglandin E2 (PGE2) metabolism in man was studied to define further the mechanisms of mucosal injury induced by indomethacin. Indomethacin caused acute gastroduodenal damage in all cases, which was maximal at 24 hours of administration. With continued intake, mucosal adaptation occurs resulting in resolution of endoscopic mucosal damage. At the time of maximal mucosal damage, gastric mucosal blood flow was significantly reduced compared with values before treatment (p less than 0.001 in fundus and p less than 0.002 in antrum), with good correlation between the severity of damage and the magnitude of the reduction in blood flow (r = 0.76). Mucosal recovery was associated with a return of the blood flow to normal. PGE2 in mucosal homogenate was significantly reduced by indomethacin in both the fundus (p less than 0.01) and antrum (p less than 0.01) after 24 hours but there was no correlation between the magnitude of this reduction and the severity of mucosal damage (r = -0.34). Despite mucosal recovery by 28 days, PGE2 values remained significantly below those before treatment in both the fundus (p less than 0.01) and antrum (p less than 0.01). The PGE2 degradation capacity was not influenced by indomethacin. In conclusion, mucosal adaptation to acute damage by indomethacin occurs in man and seems independent of local PGE2 metabolism. PMID:1541410

  3. [Study on optimal selection of structure of vaneless centrifugal blood pump with constraints on blood perfusion and on blood damage indexes].

    PubMed

    Hu, Zhaoyan; Pan, Youlian; Chen, Zhenglong; Zhang, Tianyi; Lu, Lijun

    2012-12-01

    This paper is aimed to study the optimal selection of structure of vaneless centrifugal blood pump. The optimal objective is determined according to requirements of clinical use. Possible schemes are generally worked out based on structural feature of vaneless centrifugal blood pump. The optimal structure is selected from possible schemes with constraints on blood perfusion and blood damage indexes. Using an optimal selection method one can find the optimum structure scheme from possible schemes effectively. The results of numerical simulation of optimal blood pump showed that the method of constraints of blood perfusion and blood damage is competent for the requirements of selection of the optimal blood pumps.

  4. Measuring blood delivery to solitary pulmonary nodules using perfusion magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Zheng, Wei; Wang, Zhifeng; Shen, Li; Gao, Ling; Ford, James C.; Makedon, Fillia S.; Pearlman, Justin D.

    2006-03-01

    With perfusion magnetic resonance imaging (pMRI), perfusion describes the amount of blood passing through a block of tissue in a certain period of time. In pMRI, the tissue having more blood passing through will show higher intensity value as more contrast-labeled blood arrives. Perfusion reflects the delivery of essential nutrients to a block of tissue, and is an important parameter for the tissue status. Considering solitary pulmonary nodules (SPN), perfusion differences between malignant and benign nodules have been studied by different techniques. Much effort has been put into its characterization. In this paper, we proposed and implemented extraction of the SPN time intensity profile to measure blood delivery to solitary pulmonary nodules, describing their perfusion effects. In this method, a SPN time intensity profile is created based on intensity values of the solitary pulmonary nodule in lung pMRI images over time. This method has two steps: nodule tracking and profile clustering. Nodule tracking aligns the solitary pulmonary nodule in pMRI images taken at different time points, dealing with nodule movement resulted from breathing and body movement. Profile clustering implements segmentation of the nodule region and extraction of the time intensity profile of a solitary pulmonary nodule. SPN time intensity profiles reflect patterns of blood delivery to solitary pulmonary nodules, giving us a description of perfusion effect and indirect evidence of tumor angiogenesis. Analysis on SPN time intensity profiles will help the diagnosis of malignant nodules for early lung cancer detection.

  5. Over-vibration induced blood perfusion and vascular permeability changes may lead to vocal edema.

    PubMed

    Wang, Jiajia; Devine, Erin; Fang, Rui; Jiang, Jack J

    2017-01-01

    To observe blood perfusion and vascular permeability changes under varying vibration frequency exposures. Animal model. Blood perfusion was measured using laser Doppler flowmetry in eight rabbit auricular vessels (four rabbits) under nonvibration, and 62.5-Hz/1-mm, 125-Hz/1-mm, and 250-Hz/0.5-mm vibration frequency/amplitude exposures. Another 12 rabbits were randomly divided into vibration only and vibration with histamine groups. After 3 hours of continuous 125-Hz, 1-mm amplitude vibration of the auricle, vascular permeability was analyzed by absorbance of Evans blue-albumin complex. Significantly lower blood perfusion was observed in the vibration group, compared with no vibration exposure controls. Blood perfusion decreased 29 ± 16% as the vibration frequency was increased from 62.5 Hz to 125 Hz with the vibration amplitude constant at 1 mm. When the frequency was increased from 125 Hz to 250 Hz, while the amplitude was decreased from 1 mm to 0.5 mm, blood flow perfusion further decreased 29 ± 29%, and the decline tendency in blood perfusion showed no significant difference (P = .992). Meanwhile, in the vibration with histamine group, vascular permeability of the vibrated ears increased significantly compared to the nonvibrated ears (P = .005). Overvibration of the vocal folds due to voice overuse or abuse may significantly reduce blood perfusion, and increase vascular permeability in the vocal fold in inflammatory situations, which may lead to the formation of vocal edema. NA Laryngoscope, 127:148-152, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  6. Numerical simulation of blood flow in femoral perfusion: comparison between side-armed femoral artery perfusion and direct femoral artery perfusion.

    PubMed

    Kitamura, Shingo; Shirota, Minori; Fukuda, Wakako; Inamura, Takao; Fukuda, Ikuo

    2016-12-01

    Computational numerical analysis was performed to elucidate the flow dynamics of femoral artery perfusion. Numerical simulation of blood flow was performed from the right femoral artery in an aortic model. An incompressible Navier-Stokes equation and continuity equation were solved using computed flow dynamics software. Three different perfusion models were analyzed: a 4.0-mm cannula (outer diameter 15 French size), a 5.2-mm cannula (18 French size) and an 8-mm prosthetic graft. The cannula was inserted parallel to the femoral artery, while the graft was anastomosed perpendicular to the femoral artery. Shear stress was highest with the 4-mm cannula (172 Pa) followed by the graft (127 Pa) and the 5.2-mm cannula (99 Pa). The cannula exit velocity was high, even when the 5.2-mm cannula was used. Although side-armed perfusion with an 8-mm graft generated a high shear stress area near the point of anastomosis, flow velocity at the external iliac artery was decreased. The jet speed decreased due to the Coanda effect caused by the recirculation behind sudden expansion of diameter, and the flow velocity maintains a constant speed after the reattachment length of the flow. This study showed that iliac artery shear stress was lower with the 5.2-mm cannula than with the 4-mm cannula when used for femoral perfusion. Side-armed graft perfusion generates a high shear stress area around the anastomotic site, but flow velocity in the iliac artery is slower in the graft model than in the 5.2-mm cannula model.

  7. Quantitative assessment of angiogenesis, perfused blood vessels and endothelial tip cells in the postnatal mouse brain.

    PubMed

    Wälchli, Thomas; Mateos, José María; Weinman, Oliver; Babic, Daniela; Regli, Luca; Hoerstrup, Simon P; Gerhardt, Holger; Schwab, Martin E; Vogel, Johannes

    2015-01-01

    During development and in various diseases of the CNS, new blood vessel formation starts with endothelial tip cell selection and vascular sprout migration, followed by the establishment of functional, perfused blood vessels. Here we describe a method that allows the assessment of these distinct angiogenic steps together with antibody-based protein detection in the postnatal mouse brain. Intravascular and perivascular markers such as Evans blue (EB), isolectin B4 (IB4) or laminin (LN) are used alongside simultaneous immunofluorescence on the same sections. By using confocal laser-scanning microscopy and stereological methods for analysis, detailed quantification of the 3D postnatal brain vasculature for perfused and nonperfused vessels (e.g., vascular volume fraction, vessel length and number, number of branch points and perfusion status of the newly formed vessels) and characterization of sprouting activity (e.g., endothelial tip cell density, filopodia number) can be obtained. The entire protocol, from mouse perfusion to vessel analysis, takes ∼10 d.

  8. Low perfusion index affects the difference in glucose level between capillary and venous blood

    PubMed Central

    Acar, Nurdan; Ozcelik, Hamit; Cevik, Arif Alper; Ozakin, Engin; Yorulmaz, Goknur; Kebapci, Nur; Bilge, Ugur; Bilgin, Muzaffer

    2014-01-01

    Aim In emergency cases, finger stick testing is primarily used to check the blood glucose value of patients since it takes longer to obtain the venous value. In critical patients, under conditions that cause an increase in metabolic state and level of stress, there occurs considerable difference in glucose levels between capillary and venous measurements. This study aimed to investigate the comparability of capillary and venous glucose values, according to the perfusion index level obtained with the Masimo Radical-7® device, in critical patients aged 18 years and over. Method We conducted this prospective and observational study in the emergency department of the Eskisehir Osmangazi University hospital between November 3, 2008 and February 2, 2009. Results The blood glucose of 300 critical patients was checked by finger stick in the emergency unit. The participants with normal vital signs had perfusion index between 0 and 5; the results obtained by the two methods were more consistent for perfusion index values of 6 and over. The results were most consistent in aged participants with normal vital sign findings and low perfusion index and in young patients with high perfusion index. In the cases where at least one of the vital signs was abnormal, the glucose values obtained by the two methods were more consistent when the perfusion index was 6 or over. In this group, independently from the perfusion index value, the consistency was higher in younger patients compared with aged patients. Conclusion In the emergency department, perfusion index value measured by Masimo Radical-7 and capillary blood glucose levels can serve in blood sugar management in critically ill patients. PMID:25429227

  9. Shape matters: the effect of red blood cell shape on perfusion of an artificial microvascular network.

    PubMed

    Piety, Nathaniel Z; Reinhart, Walter H; Pourreau, Patrick H; Abidi, Rajaa; Shevkoplyas, Sergey S

    2016-04-01

    The shape of human red blood cells (RBCs) deteriorates progressively throughout hypothermic storage, with echinocytosis being the most prevalent pathway of this morphologic lesion. As a result, each unit of stored blood contains a heterogeneous mixture of cells in various stages of echinocytosis and normal discocytes. Here we studied how the change in shape of RBCs following along the path of the echinocytic transformation affects perfusion of an artificial microvascular network (AMVN). Blood samples were obtained from healthy consenting volunteers. RBCs were leukoreduced, resuspended in saline, and treated with various concentrations of sodium salicylate to induce shape changes approximating the stages of echinocytosis experienced by RBCs during hypothermic storage (e.g., discocyte, echinocyte I, echinocyte II, echinocyte III, spheroechinocyte, and spherocyte). The AMVN perfusion rate was measured for 40% hematocrit suspensions of RBCs with different shapes. The AMVN perfusion rates for RBCs with discocyte and echinocyte I shapes were similar, but there was a significant decline in the AMVN perfusion rate between RBCs with shapes approximating each subsequent stage of echinocytosis. The difference in AMVN perfusion between discocytes and spherocytes (the last stage of the echinocytic transformation) was 34%. The change in shape of RBCs from normal discocytes progressively through various stages of echinocytosis to spherocytes produced a substantial decline in the ability of these cells to perfuse an AMVN. Echinocytosis induced by hypothermic storage could therefore be responsible for a similarly substantial impairment of deformability previously observed for stored RBCs. © 2015 AABB.

  10. Lumped-parameter tissue temperature-blood perfusion model of a cold-stressed fingertip.

    PubMed

    Shitzer, A; Stroschein, L A; Gonzalez, R R; Pandolf, K B

    1996-05-01

    A lumped-parameter model of a fingertip is presented. The semispherical model includes the effects of heat storage, heat exchange with the environment, and heat transport by blood perfusion. The thermal insulation on the surface of the fingertip is represented by the overall heat transfer coefficient that is calculated by common engineering formulas. The model is solved analytically for the simple case of constant blood perfusion rate. The general case of variable blood perfusion rates is solved by an Euler finite difference technique. At this stage, the model does not include active control mechanisms of blood perfusion. Thus the effects of cold-induced vasodilatation have to be superimposed and are modeled by symmetrical triangular waveforms because these were found to best depict the behavior of fingers exposed to cold environments. Results of this model were compared with experimental data obtained in two separate studies. One included 60-min infrared thermograms of the dorsal surface of bare hands of sedentary subjects horizontally suspended on a fish net in a 0 degree C environment. Another study, on gloved finger temperatures, involved 0 and -6.7 degrees C environments. Fingertip (nail bed) temperatures of both these studies were compared with model predictions. Blood perfusion rates were assumed and adjusted within physiologically reasonable limits. Comparison of measured and computed temperature records showed very good conformity in both cases studied.

  11. Relative indexes of cutaneous blood perfusion measured by real-time laser Doppler imaging (LDI) in healthy volunteers.

    PubMed

    Seyed Jafari, S Morteza; Schawkat, Megir; Van De Ville, Dimitri; Shafighi, Maziar

    2014-07-01

    We used real-time LDI to study regional variations in microcirculatory perfusion in healthy candidates to establish a new methodology for global perfusion body mapping that is based on intra-individual perfusion index ratios. Our study included 74 (37 female) healthy volunteers aged between 22 and 30 years (mean 24.49). Imaging was performed using a recent microcirculation-imaging camera (EasyLDI) for different body regions of each volunteer. The perfusion values were reported in Arbitrary Perfusion Units (APU). The relative perfusion indexes for each candidate's body region were then obtained by normalization with the perfusion value of the forehead. Basic parameters such as weight, height, and blood pressure were also measured and analyzed. The highest mean perfusion value was reported in the forehead area (259.21APU). Mean perfusion in the measured parts of the body correlated positively with mean forehead value, while there was no significant correlation between forehead blood perfusion values and room temperature, BMI, systolic blood pressure and diastolic blood pressure (p=0.420, 0.623, 0.488, 0.099, respectively). Analysis of the data showed that perfusion indexes were not significantly different between male and female volunteers except for the ventral upper arm area (p=.001). LDI is a non-invasive, fast technique that opens several avenues for clinical applications. The mean perfusion indexes are useful in clinical practice for monitoring patients before and after surgical interventions. Perfusion values can be predicted for different body parts for patients only by taking the forehead perfusion value and using the perfusion index ratios to obtain expected normative perfusion values. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Muscle Tissue Saturation Compared With Muscle Tissue Perfusion During Low Blood Flows: An Experimental Study.

    PubMed

    Thomassen, Sisse Anette; Kjærgaard, Benedict; Olsen Alstrup, Aage Kristian; Munk, Ole Lajord; Frøkiær, Jørgen; Larsson, Anders; Rasmussen, Bodil Steen

    2017-03-22

    To investigate whether changes in muscle tissue perfusion measured with positron emission tomography would be reflected by parallel changes in muscle tissue oxygen saturation (StO2) measured using near-infrared spectroscopy during high and low blood flow levels achieved using cardiopulmonary bypass (CPB) in an animal model. A prospective, randomized study. Research laboratory, single institution. Eight pigs (69-71 kg). In anesthetized pigs, normothermic CPB was established with a blood flow of 60 mL/kg/min for 1 hour. Thereafter, a low blood flow of either 47.5 or 35 mL/kg/min was applied for 1 hour followed by a blood flow of 60 mL/kg/min for an additional hour. Regional StO2 was measured continuously by placing a near-infrared spectroscopy electrode on the skin above the gracilis muscle of the noncannulated back leg. Muscle tissue perfusion was measured using positron emission tomography with (15)O-labeled water during spontaneous circulation and the different CPB blood flows. Systemic oxygen consumption was estimated by measurement of venous saturation and lactate levels. The results showed profound systemic ischemia during low CPB blood flow. StO2 remained high until muscle tissue perfusion decreased to about 50%, after which StO2 paralleled the linear decrease in muscle tissue perfusion. In an experimental CPB animal model, StO2 was stable until muscle tissue perfusion was reduced by about 50%, and at lower blood flow levels, there was almost a linear relationship between StO2 and muscle tissue perfusion. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. In vitro fabrication of functional three-dimensional tissues with perfusable blood vessels

    PubMed Central

    Sekine, Hidekazu; Shimizu, Tatsuya; Sakaguchi, Katsuhisa; Dobashi, Izumi; Wada, Masanori; Yamato, Masayuki; Kobayashi, Eiji; Umezu, Mitsuo; Okano, Teruo

    2013-01-01

    In vitro fabrication of functional vascularized three-dimensional tissues has been a long-standing objective in the field of tissue engineering. Here we report a technique to engineer cardiac tissues with perfusable blood vessels in vitro. Using resected tissue with a connectable artery and vein as a vascular bed, we overlay triple-layer cardiac cell sheets produced from coculture with endothelial cells, and support the tissue construct with media perfused in a bioreactor. We show that endothelial cells connect to capillaries in the vascular bed and form tubular lumens, creating in vitro perfusable blood vessels in the cardiac cell sheets. Thicker engineered tissues can be produced in vitro by overlaying additional triple-layer cell sheets. The vascularized cardiac tissues beat and can be transplanted with blood vessel anastomoses. This technique may create new opportunities for in vitro tissue engineering and has potential therapeutic applications. PMID:23360990

  14. Pattern of brain blood perfusion in tinnitus patients using technetium-99m SPECT imaging

    PubMed Central

    Mahmoudian, Saeid; Farhadi, Mohammad; Gholami, Saeid; Saddadi, Fariba; Karimian, Ali Reza; Mirzaei, Mohammad; Ghoreyshi, Esmaeel; Ahmadizadeh, Majid; Lenarz, Thomas

    2012-01-01

    Background and Purpose: Tinnitus is associated with an increased activity in central auditory system as demonstrated by neuroimaging studies. Brain perfusion scanning using single photon emission computed tomography (SPECT) was done to understand the pattern of brain blood perfusion of tinnitus subjects and find the areas which are mostly abnormal in these patients. Materials and Methods: A number of 122 patients with tinnitus were enrolled to this cross-sectional study. They underwent SPECT and magnetic resonance imaging (MRI) of brain, and the images were fused to find the regions with abnormal perfusion. Results: SPECT scan results were abnormal in 101 patients (83%). Most patients had bilateral abnormal perfusion (N = 65, 53.3%), and most subjects had abnormality in middle-temporal gyrus (N = 83, 68%) and temporoparietal cortex (N = 46, 37.7%). Patients with multifocal involvement had the least mean age than other 2 groups (patients with no abnormality and unifocal abnormality) (P value = 0.045). Conclusions: Brain blood perfusion pattern differs in patient with tinnitus than others. These patients have brain perfusion abnormality, mostly in auditory gyrus (middle temporal) and associative cortex (temporoparietal cortex). Multifocal abnormalities might be due to more cognitive and emotional brain centers involvement due to tinnitus or more stress and anxiety of tinnitus in the young patients. PMID:23267375

  15. Role of gastric blood flow, neutrophil infiltration, and mucosal cell proliferation in gastric adaptation to aspirin in the rat.

    PubMed Central

    Konturek, S J; Brzozowski, T; Stachura, J; Dembinski, A; Majka, J

    1994-01-01

    Gastric mucosa exhibits the ability to adapt to ulcerogenic action of aspirin but the mechanism of this phenomenon is unknown. In this study, acute gastric lesions were produced by single or repeated doses of acidified aspirin in rats with intact or resected salivary glands and with intact or suppressed synthase of nitric oxide. A single oral dose of aspirin produced a dose dependent increase in gastric lesions accompanied by considerable blood neutrophilia and mucosal neutrophil infiltration, significant reduction in gastric blood flow, and almost complete suppression of biosynthesis of prostaglandins. After rechallenge with aspirin, the mucosal damage became smaller and progressively declined with repeated aspirin insults. Gastric adaptation to aspirin was accompanied by a significant rise in gastric blood flow, reduction in both blood neutrophilia and mucosal neutrophil infiltration, and a remarkable increase in mucosal cell regeneration and mucosal content of epidermal growth factor. Salivectomy, which reduced the mucosal content of epidermal growth factor, aggravated the initial mucosal damage induced by the first exposure to acidified aspirin but did not prevent the adaptation of this mucosa to repeated aspirin insults. Pretreatment with NG-nitro-L-arginine (L-NNA), a specific inhibitor of nitric oxide synthase, eliminated the hyperaemic response to repeated aspirin but did not abolish the development of adaptation to aspirin showing that the maintenance of the gastric blood flow plays little part in this adaptation. In conclusion, the stomach adapts readily to repeated aspirin insults and this is accompanied by a considerable reduction in blood neutrophilia and the severity of neutrophil infiltration and by an extensive proliferation of mucosal cells possibly involving epidermal growth factor. PMID:7525421

  16. Nifedipine improves blood flow and oxygen supply, but not steady-state oxygenation of tumours in perfusion pressure-controlled isolated limb perfusion.

    PubMed

    Thews, O; Hummel, M; Kelleher, D K; Lecher, B; Vaupel, P

    2002-12-02

    Isolated limb perfusion allows the direct application of therapeutic agents to a tumour-bearing extremity. The present study investigated whether the dihydropyridine-type Ca(2+)-channel blocker nifedipine could improve blood flow and oxygenation status of experimental tumours during isolated limb perfusion. Perfusion was performed by cannulation of the femoral artery and vein in rats bearing DS-sarcoma on the hind foot dorsum. Perfusion rate was adjusted to maintain a perfusion pressure of 100-140 mmHg throughout the experiment. Following equilibration, nifedipine was continuously infused for 30 min (8.3 microg min(-1) kg(-1) BW). During constant-pressure isolated limb perfusion, nifedipine can significantly increase perfusion rate (+100%) and RBC flux (+60%) through experimental leg tumours. "Steal phenomena" in favour of the surrounding normal tissue and oedema formation were not observed. Despite the increased oxygen availability (+63%) seen upon application of this calcium channel blocker, nifedipine does not result in a substantial reduction of tumour hypoxia, most probably due to an increase in O(2) uptake with rising O(2) supply to the tumour-bearing hind limb. Nifedipine application during isolated limb perfusion can enhance tumour microcirculation and may therefore promote the delivery (pharmacokinetics) of anti-cancer drugs to the tumour and by this improve the efficacy of pressure-controlled isolated limb perfusion.

  17. Prevention of blood cell adhesion in porous inner wall of double-layered tube by saline perfusion.

    PubMed

    Kim, S S; Park, J B

    1993-01-01

    A double-layered tube consisting of a porous inner tube and a solid outer tube was used to perfuse isotonic saline solution into blood to prevent blood cell adhesion. Polystyrene/poly(styrene-co-butadiene) (PS-SBR) porous tubes were made using a dipping method. Citrated canine blood was circulated for 30 min with the flow rate of 100 ml/min using an in vitro blood circulation setup which makes nonpulsatile blood flow. Blood cell adhesion in the PS/SBR porous tubes decreased with increased saline perfusion rate regardless of changes in variables such as tube porosities, tube materials, and perfusion materials. The relationship between blood cell adhesion and perfusion rate was semi-logarithmic. Blood cell adhesion was relatively high in the more porous tube (65% sugar tube), compared to the less porous tube (55% sugar tube) for an identical saline perfusion rate. The blood cell adhesion in the sulfonated PS/SBR porous tube was less than that in the nonsulfonated (control) PS/SBR porous tube. The blood cell adhesion was also decreased by citrate perfusion. The results of this study indicates that the saline perfusion method can be used to prevent blood cell adhesion in the blood lines of extracorporeal circulation systems (such as hemodialysis and heart-lung machines) if certain technical problems involving the surface roughness can be resolved.

  18. Three-dimensional optical micro-angiography maps directional blood perfusion deep within microcirculation tissue beds in vivo

    NASA Astrophysics Data System (ADS)

    Wang, Ruikang K.

    2007-12-01

    Optical micro-angiography (OMAG) is a recently developed method of imaging localized blood perfusion at capillary level resolution within microcirculatory beds. This paper reports that the OMAG is capable of directional blood perfusion mapping in vivo. This is achieved simply by translating the mirror located in the reference arm back and forth while 3D imaging is performed. The mirror which moves toward the incident beam gives the blood perfusion that flows away from the beam direction and vice versa. The approach is experimentally demonstrated by imaging of a flow phantom and then cerebro-vascular perfusion of a live mouse with cranium intact.

  19. The effects of scraping therapy on local temperature and blood perfusion volume in healthy subjects.

    PubMed

    Xu, Qin-Yan; Yang, Jin-Sheng; Zhu, Bing; Yang, Li; Wang, Ying-Ying; Gao, Xin-Yan

    2012-01-01

    Objective. We aim to study the therapeutic effects of scraping by investigating the changes of temperature and local blood perfusion volume in healthy subjects after scraping stimulation, and to explore the mechanism of scraping stimulation from the points of microcirculation and energy metabolism. Methods. Twenty-three health subjects were included in this study. Local blood perfusion volume and body surface temperature was detected at 5 min before scraping stimulation, 0, 15, 30, 60 and 90 min after scraping using Laser Doppler imager and infrared thermograph. Results. Significant increase was noted in the blood perfusion volume in the scraping area within 90 minutes compared to the baseline level and non-scraping area (P < 0.001). Compared with non-scraping area, an increase of body temperature with an average of 1°C was observed after scraping stimulation (P < 0.01). Conclusion. Scraping can significantly improve the blood perfusion volume and increase the temperature in the scraping area, promoting the local blood circulation and energy metabolism.

  20. Ocular perfusion pressure and ocular blood flow in glaucoma

    PubMed Central

    Cherecheanu, A Popa; Garhofer, G; Schmidl, D; Werkmeister, R; Schmetterer, L

    2013-01-01

    Glaucoma is a progressive optic neuropathy of unknown origin. It has been hypothesized that a vascular component is involved in glaucoma pathophysiology. This hypothesis has gained support from studies showing that reduced ocular perfusion pressure is a risk factor for the disease. The exact nature of the involvement is, however, still a matter of debate. Based on recent evidence we propose a model including primary and secondary insults in glaucoma. The primary insult appears to happen at the optic nerve head. Increased intraocular pressure and ischemia at the post-laminar optic nerve head affects retinal ganglion cell axons. Modulating factors are the biomechanical properties of the tissues and cerebrospinal fluid pressure. After this primary insult retinal ganglion cells function at a reduced energy level and are sensitive to secondary insults. These secondary insults may happen if ocular perfusion pressure falls below the lower limit of autoregulation or if neurovascular coupling fails. Evidence for both faulty autoregulation and reduced hyperemic response to neuronal stimulation has been provided in glaucoma patients. The mechanisms appear to involve vascular endothelial dysfunction and impaired astrocyte-vessel signaling. A more detailed understanding of these pathways is required to direct neuroprotective strategies via the neurovascular pathway. PMID:23009741

  1. Selective renal blood perfusion induces renal tubules injury in a porcine model.

    PubMed

    Kalder, Johannes; Kokozidou, Maria; Keschenau, Paula; Tamm, Miriam; Greiner, Andreas; Koeppel, Thomas A; Tolba, Rene; Jacobs, Michael J

    2016-03-01

    Extracorporeal circulation is routinely used in thoracoabdominal aortic aneurysm repair to preserve blood perfusion. Despite this protective measure, acute and chronic kidney disorders can develop. Therefore, the aim of this study was to establish a new large-animal model to assess the efficacy of selective renal perfusion (SRP) with extracorporeal circulation in a setting of thoracoabdominal aortic aneurysm repair. Eighteen pigs underwent a thoracolaparotomy, during with the aorta and renal arteries were exposed. The animals were divided into three cohorts of six pigs each: cohort I--control; cohort II--thoracic aortic clamping with distal aortic perfusion (DAP) using a roller pump; and cohort III--thoracic aortic clamping with DAP plus SRP. Kidney metabolism, kidney injury, and red blood cell damage were measured by oxygen extraction ratio (O2ER), neutrophil gelatinase-associated lipocalin, a marker for acute kidney damage, and serum free hemoglobin. With normal mean arterial blood pressures, flow rates in the renal arteries during perfusion decreased to 75% (group II) with DAP and to 50% (group III) with SRP compared with the control animals (group I; P = .0279 for I vs II; P = .0002 for I vs III). Microcirculation, measured by microspheres, did not differ significantly among the groups. In contrast, O2ER (P = .0021 for I vs III) and neutrophil gelatinase-associated lipocalin (P = .0083 for I vs III) levels were significantly increased in group III, whereas free hemoglobin was increased in groups II and III (P = .0406 for I vs II; P = .0018 for I vs III). SRP with a roller pump induces kidney tubule injury. Thus, distal aortic and SRP in our model does not provide adequate kidney protection. Furthermore, the perfusion system provokes red blood cell damage with increased free hemoglobin. Hence, the SRP perfusion technique should be revised and tested. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  2. Skin blood perfusion and cellular response to insertion of insulin pen needles with different diameters.

    PubMed

    Præstmark, Kezia Ann; Jensen, Casper Bo; Stallknecht, Bente; Madsen, Nils Berg; Kildegaard, Jonas

    2014-07-01

    Today most research on pen needle design revolves around pain perception statements through clinical trials, but these are both costly, timely, and require high sample sizes. The purpose of this study was to test if tissue damage, caused by different types of needles, can be assessed by evaluating skin blood perfusion response around needle insertion sites. Three common sized pen needles of 28G, 30G, and 32G as well as hooked 32G needles, were inserted into the neck skin of pigs and then removed. Laser Speckle Contrast Analysis was used to measure skin blood perfusion for 20 minutes after the insertions. Seven pigs were included in the study and a total of 118 randomized needle insertions were conducted. Histology was made of tissue samples inserted with 18G, 28G, and 32G needles, and stained to quantify red and white blood cell response. Based on area under curve, calculated for each individual blood perfusion recording and grouped according to needle type, skin blood perfusion response relates to needle diameter. The response was significantly higher after insertions with 28G and hooked 32G needles than with 30G (P < .05) and 32G (P < .01) needles. Histology results were not significant, but there was a trend of an increased response with increasing needle diameter. Skin blood perfusion response to pen needle insertions rank according to needle diameter, and the tissue response caused by hooked 32G needles corresponds to that of 28G needles. The relation between needle diameter and trauma when analyzing histology was also suggested. © 2014 Diabetes Technology Society.

  3. [Microvascular consequences of low distal blood perfusion rates].

    PubMed

    Merlen, J F

    1985-01-01

    It is classical, in obstructive arterial disease, to be most concerned with the truncal arteries, although nutrition and exchanges occur at the level of the terminal vessels. The most important events occur in the muscles and in the skin, at the extremity of the limb and one wonders whether "ischaemic disease" could perhaps be summarized as the result of low perfusion rates. The laws of hydraulics are unusual in this situation, the microcirculation is autonomous and autoregulated. The architectonics are also unusual: the distribution into asymmetrical parallel networks explains the heterogeneity of the distribution in which stasis, conglutination and red cell rigidity, interstitial flooding and the rheological consequences play a major though unequal role in the skin and the muscle. The problems of the haematocrit, viscosity, surface tension or interface and the electrostatic potentials are more important at this level and they determine the therapeutic decisions.

  4. Decreased Cerebral Blood Flow in Chronic Pediatric Mild TBI: An MRI Perfusion Study

    PubMed Central

    Wang, Yang; West, John D.; Bailey, Jessica N.; Westfall, Daniel R.; Xiao, Hui; Arnold, Todd W.; Kersey, Patrick A.; Saykin, Andrew J.; McDonald, Brenna C.

    2015-01-01

    We evaluated cerebral blood flow (CBF) in chronic pediatric mild traumatic brain injury (mTBI) using arterial spin labeling (ASL) magnetic resonance imaging perfusion. mTBI patients showed lower CBF than controls in bilateral frontotemporal regions, with no between-group cognitive differences. Findings suggest ASL may be useful to assess functional abnormalities in pediatric mTBI. PMID:25649779

  5. The relationship between red blood cell deformability metrics and perfusion of an artificial microvascular network

    PubMed Central

    Sosa, Jose M.; Nielsen, Nathan D.; Vignes, Seth M.; Chen, Tanya G.; Shevkoplyas, Sergey S.

    2013-01-01

    The ability of red blood cells (RBC) to undergo a wide range of deformations while traversing the microvasculature is crucial for adequate perfusion. Interpretation of RBC deformability measurements performed in vitro in the context of microvascular perfusion has been notoriously difficult. This study compares the measurements of RBC deformability performed using micropore filtration and ektacytometry with the RBC ability to perfuse an artificial microvascular network (AMVN). Human RBCs were collected from healthy consenting volunteers, leukoreduced, washed and exposed to graded concentrations (0% – 0.08%) of glutaraldehyde (a non-specific protein cross-linker) and diamide (a spectrin-specific protein cross-linker) to impair the deformability of RBCs. Samples comprising cells with two different levels of deformability were created by adding non-deformable RBCs (hardened by exposure to 0.08% glutaraldehyde) to the sample of normal healthy RBCs. Ektacytometry indicated a nearly linear decline in RBC deformability with increasing glutaraldehyde concentration. Micropore filtration showed a significant reduction only for concentrations of glutaraldehyde higher than 0.04%. Neither micropore filtration nor ektacytometry measurements could accurately predict the AMVN perfusion. Treatment with diamide reduced RBC deformability as indicated by ektacytometry, but had no significant effect on either micropore filtration or the AMVN perfusion. Both micropore filtration and ektacytometry showed a linear decline in effective RBC deformability with increasing fraction of non-deformable RBCs in the sample. The corresponding decline in the AMVN perfusion plateaued above 50%, reflecting the innate ability of blood flow in the microvasculature to bypass occluded capillaries. Our results suggest that in vitro measurements of RBC deformability performed using either micropore filtration or ektacytometry may not represent the ability of same RBCs to perfuse microvascular networks

  6. The relationship between red blood cell deformability metrics and perfusion of an artificial microvascular network.

    PubMed

    Sosa, Jose M; Nielsen, Nathan D; Vignes, Seth M; Chen, Tanya G; Shevkoplyas, Sergey S

    2014-01-01

    The ability of red blood cells (RBC) to undergo a wide range of deformations while traversing the microvasculature is crucial for adequate perfusion. Interpretation of RBC deformability measurements performed in vitro in the context of microvascular perfusion has been notoriously difficult. This study compares the measurements of RBC deformability performed using micropore filtration and ektacytometry with the RBC ability to perfuse an artificial microvascular network (AMVN). Human RBCs were collected from healthy consenting volunteers, leukoreduced, washed and exposed to graded concentrations (0-0.08%) of glutaraldehyde (a non-specific protein cross-linker) and diamide (a spectrin-specific protein cross-linker) to impair the deformability of RBCs. Samples comprising cells with two different levels of deformability were created by adding non-deformable RBCs (hardened by exposure to 0.08% glutaraldehyde) to the sample of normal healthy RBCs. Ektacytometry indicated a nearly linear decline in RBC deformability with increasing glutaraldehyde concentration. Micropore filtration showed a significant reduction only for concentrations of glutaraldehyde higher than 0.04%. Neither micropore filtration nor ektacytometry measurements could accurately predict the AMVN perfusion. Treatment with diamide reduced RBC deformability as indicated by ektacytometry, but had no significant effect on either micropore filtration or the AMVN perfusion. Both micropore filtration and ektacytometry showed a linear decline in effective RBC deformability with increasing fraction of non-deformable RBCs in the sample. The corresponding decline in the AMVN perfusion plateaued above 50%, reflecting the innate ability of blood flow in the microvasculature to bypass occluded capillaries. Our results suggest that in vitro measurements of RBC deformability performed using either micropore filtration or ektacytometry may not represent the ability of same RBCs to perfuse microvascular networks. Further

  7. Separating blood and water: Perfusion and free water elimination from diffusion MRI in the human brain.

    PubMed

    Rydhög, Anna S; Szczepankiewicz, Filip; Wirestam, Ronnie; Ahlgren, André; Westin, Carl-Fredrik; Knutsson, Linda; Pasternak, Ofer

    2017-08-01

    The assessment of the free water fraction in the brain provides important information about extracellular processes such as atrophy and neuroinflammation in various clinical conditions as well as in normal development and aging. Free water estimates from diffusion MRI are assumed to account for freely diffusing water molecules in the extracellular space, but may be biased by other pools of molecules in rapid random motion, such as the intravoxel incoherent motion (IVIM) of blood, where water molecules perfuse in the randomly oriented capillary network. The goal of this work was to separate the signal contribution of the perfusing blood from that of free-water and of other brain diffusivities. The influence of the vascular compartment on the estimation of the free water fraction and other diffusivities was investigated by simulating perfusion in diffusion MRI data. The perfusion effect in the simulations was significant, especially for the estimation of the free water fraction, and was maintained as long as low b-value data were included in the analysis. Two approaches to reduce the perfusion effect were explored in this study: (i) increasing the minimal b-value used in the fitting, and (ii) using a three-compartment model that explicitly accounts for water molecules in the capillary blood. Estimation of the model parameters while excluding low b-values reduced the perfusion effect but was highly sensitive to noise. The three-compartment model fit was more stable and additionally, provided an estimation of the volume fraction of the capillary blood compartment. The three-compartment model thus disentangles the effects of free water diffusion and perfusion, which is of major clinical importance since changes in these components in the brain may indicate different pathologies, i.e., those originating from the extracellular space, such as neuroinflammation and atrophy, and those related to the vascular space, such as vasodilation, vasoconstriction and capillary density

  8. Blood temperature and perfusion to exercising and non‐exercising human limbs

    PubMed Central

    Calbet, José A. L.; Boushel, Robert; Helge, Jørn W.; Søndergaard, Hans; Munch‐Andersen, Thor; van Hall, Gerrit; Mortensen, Stefan P.; Secher, Niels H.

    2015-01-01

    New Findings What is the central question of this study? Temperature‐sensitive mechanisms are thought to contribute to blood‐flow regulation, but the relationship between exercising and non‐exercising limb perfusion and blood temperature is not established. What is the main finding and its importance? The close coupling among perfusion, blood temperature and aerobic metabolism in exercising and non‐exercising extremities across different exercise modalities and activity levels and the tight association between limb vasodilatation and increases in plasma ATP suggest that both temperature‐ and metabolism‐sensitive mechanisms are important for the control of human limb perfusion, possibly by activating ATP release from the erythrocytes. Temperature‐sensitive mechanisms may contribute to blood‐flow regulation, but the influence of temperature on perfusion to exercising and non‐exercising human limbs is not established. Blood temperature (T B), blood flow and oxygen uptake (V˙O2) in the legs and arms were measured in 16 healthy humans during 90 min of leg and arm exercise and during exhaustive incremental leg or arm exercise. During prolonged exercise, leg blood flow (LBF) was fourfold higher than arm blood flow (ABF) in association with higher T B and limb V˙O2. Leg and arm vascular conductance during exercise compared with rest was related closely to T B (r 2 = 0.91; P < 0.05), plasma ATP (r 2 = 0.94; P < 0.05) and limb V˙O2 (r 2 = 0.99; P < 0.05). During incremental leg exercise, LBF increased in association with elevations in T B and limb V˙O2, whereas ABF, arm T B and V˙O2 remained largely unchanged. During incremental arm exercise, both ABF and LBF increased in relationship to similar increases in V˙O2. In 12 trained males, increases in femoral T B and LBF during incremental leg exercise were mirrored by similar pulmonary artery T B and cardiac output dynamics, suggesting that processes in active limbs dominate central

  9. Effect of treppe on isovolumic function in the isolated blood-perfused mouse heart.

    PubMed

    Brooks, W W; Apstein, C S

    1996-08-01

    The effects of treppe on left ventricular function in the isolated mouse heart perfused with physiological buffer or with erythrocyte-rich buffer were compared. Left ventricular systolic and diastolic pressures were measured in the isovolumically contracting (balloon in the left ventricle) mouse hearts. Hearts were isolated from 12 adult Swiss-Webster mice and perfused at constant pressure (approximately 85 mmHg) via the aorta. Perfusate consisted of non-recirculating oxygenated Krebs-Henseleit (KH) solution without or with washed cow red blood cells at a hematocrit of 20% (KH-RBC20). The measured ionized calcium concentration of the perfusates were adjusted to 2.2 mmol/l and the temperature held constant at 37 degrees C. Left ventricular systolic pressure, its derivative and diastolic pressures were recorded via a pressure transducer attached to a small latex balloon which was placed in the left ventricle through a left atrial incision. The balloon volume was adjusted to achieve an end-diastolic pressure of 4-8 mmHg. Left ventricular (LV) developed pressure averaged 111 +/- 4 (mean +/- S.E.M.) with KH alone and 108 +/- 4 mmHg with KH-RBC20 while the coronary flows were 3.1 +/- 0.18 and 0.95 +/- 0.15 ml/min respectively. In both KH solution alone and KH-RBC20, developed pressure remained relatively stable from 3 to 5 Hz while +/- dp/dt increased approximately 10% above values observed at 3 Hz. During KH perfusion with increasing stimulation rates, left ventricular pressure and +/- dP/dt, to a lesser extent, decreased while end-diastolic pressure markedly increased at stimulation rates higher than 5 Hz. However, KH-RBC20 perfusion prevented the marked increase in diastolic pressure with increasing stimulation rates (from 5 to 10 Hz). No significant difference in left ventricular developed pressure or +/dP/dt response to treppe were in evidence between groups. These results demonstrate that diastolic function of the isovolumically contracting mouse heart is sensitive

  10. Optical microangiography reveals collateral blood perfusion dynamics in mouse cerebral cortex after focal stroke

    NASA Astrophysics Data System (ADS)

    Baran, Utku; Li, Yuandong; Wang, Ruikang K.

    2015-03-01

    Arteriolo-arteriolar anastomosis's role in regulating blood perfusion through penetrating arterioles during stroke is yet to be discovered. We apply ultra-high sensitive optical microangiography (UHS-OMAG) and Doppler optical microangiography (DOMAG) techniques to evaluate vessel diameter and red blood cell velocity changes in large number of pial and penetrating arterioles in relation with arteriolo-arteriolar anastomosis (AAA) during and after focal stroke. Thanks to the high sensitivity of UHS-OMAG, we were able to image pial microvasculature up to capillary level through a cranial window (9 mm2), and DOMAG provided clear image of penetrating arterioles up to 500μm depth. Results showed that penetrating arterioles close to a strong AAA connection dilate whereas penetrating arterioles constrict significantly in weaker AAA regions. These results suggest that AAA plays a major role in active regulation of the pial arterioles, and weaker AAA connections lead to poor blood perfusion to penumbra through penetrating arterioles.

  11. [Effect of vinylsorb SS on the morphology and coagulability of blood during perfusion in vitro].

    PubMed

    Jurkowski, P; Cwiklińska-Jurkowska, M; Kotschy, M; Zekanowska, E

    1993-01-01

    In the paper the changes appearing in in vitro during perfusion of citrated blood through a column filled with Vinylsorb SS in temperature of 22 and 37 degrees C were evaluated. In both temperatures there was a slight decrease of the number of leucocytes and thrombocytes, both in the examined and the control system. The remaining number of thrombocytes ensured hemostasia. The authors think that the main factor causing decrease of the number of morphotic elements of blood as well as activating slightly coagulation system was the effect of drains, a peristaltic pump, blood container and perfusion column and not the sorbent. Vinylsorb turned out to be a good and safe sorbent which should be applied in the process of hemoperfusion in people.

  12. The blood perfusion and NADH/FAD content combined analysis in patients with diabetes foot

    NASA Astrophysics Data System (ADS)

    Dremin, Victor V.; Sidorov, Victor V.; Krupatkin, Alexander I.; Galstyan, Gagik R.; Novikova, Irina N.; Zherebtsova, Angelina I.; Zherebtsov, Evgeny A.; Dunaev, Andrey V.; Abdulvapova, Zera N.; Litvinova, Karina S.; Rafailov, Ilya E.; Sokolovski, Sergei G.; Rafailov, Edik U.

    2016-03-01

    Skin blood microcirculation and the metabolism activity of tissue were examined on the patients with type 2 diabetes. Laser Doppler flowmetry (LDF) with 1064 nm laser light source and fluorescence spectroscopy (FS) with excitation light of 365 nm and 450 nm have been used to monitor the blood perfusion and the content of coenzymes NADH and FAD. Concluding, the proposed combined LDF and tissue FS approach allows to identify the significant violations in the blood microcirculation and metabolic activity for type 2 diabetes patients.

  13. Photoacoustic imaging of blood perfusion in tissue and phantoms

    NASA Astrophysics Data System (ADS)

    Pilatou, Magdalena C.; Kolkman, Roy G. M.; Hondebrink, Erwin; Bolt, Rene A.; de Mul, Frits F. M.

    2001-06-01

    To localize and monitor the blood content in tissue we developed a very sensitive photo-acoustical detector. PVDF has been used as piezo-electric material. In this detector also fibers for the illumination of the sample are integrated. Resolution is about 20 (m in depth and about 50-100 m laterally). We use 532 nm light. We will show how photoacoustics can be used for measuring the thickness of tissue above bone. We will also report measurements on tissue phantoms: e.g. a vessel delta from the epigastric artery branching of a Wistar rat, filled with an artificial blood-resembling absorber. The measurements have been carried out on phantoms containing vessels at several depths. Signal processing was enhanced by Fourier processing of the data.

  14. Increased blood-brain barrier permeability on perfusion CT might predict malignant middle cerebral artery infarction.

    PubMed

    Bektas, Hesna; Wu, Tzu-Ching; Kasam, Mallikarjunarao; Harun, Nusrat; Sitton, Clark W; Grotta, James C; Savitz, Sean I

    2010-11-01

    Perfusion CT has been used to assess the extent of blood-brain barrier breakdown. The purpose of this study was to determine the predictive value of blood-brain barrier permeability measured using perfusion CT for development of malignant middle cerebral artery infarction requiring hemicraniectomy (HC). We retrospectively identified patients from our stroke registry who had middle cerebral artery infarction and were evaluated with admission perfusion CT. Blood-brain barrier permeability and cerebral blood volume maps were generated and infarct volumes calculated. Clinical and radiographic characteristics were compared between those who underwent HC versus those who did not undergo HC. One hundred twenty-two patients (12 HC, 110 no HC) were identified. Twelve patients who underwent HC had developed edema, midline shift, or infarct expansion. Infarct permeability area, infarct cerebral blood volume area, and infarct volumes were significantly different (P < 0.018, P < 0.0211, P < 0.0001, P < 0.0014) between HC and no HC groups. Age (P = 0.03) and admission National Institutes of Health Stroke Scale (P = 0.0029) were found to be independent predictors for HC. Using logistic regression modeling, there was an association between increased infarct permeability area and HC. The OR for HC based on a 5-, 10-, 15-, or 20-cm² increase in infarct permeability area were 1.179, 1.390, 1.638, or 1.932, respectively (95% CI, 1.035 to 1.343, 1.071 to 1.804, 1.108 to 2.423, 1.146 to 3.255, respectively). Increased infarct permeability area is associated with an increased likelihood for undergoing HC. Because early HC for malignant middle cerebral artery infarction has been associated with better outcomes, the infarct permeability area on admission perfusion CT might be a useful tool to predict malignant middle cerebral artery infarction and need for HC.

  15. A weighted block-PCA infrared face recognition method based on blood perfusion image

    NASA Astrophysics Data System (ADS)

    Xie, Zhihua; Liu, Guodong; Wu, Shiqian; Fang, Zhijun

    2009-10-01

    In this paper, a novel method for infrared face recognition based on blood perfusion is proposed in this paper. Firstly, thermal images are converted into blood perfusion domain to enlarge between-class distance and lessen within-class distance, which makes full use of the biological feature of the human face. Based on the ratio of between-class distance to within-class distance (Ratio of Distance (RD)) in sub-blocks, block-PCA is utilized to get the local discrimination information, which can solve the small sample size problem (the null space problem). Finally, The FLD is applied to the holistic features combined by the extracted coefficients from the information of all sub-blocks. The experiments illustrate that the block-PCA+FLD doesn't discard the useful discriminant information in the holistic characters and the method proposed in this paper has better performance compared with traditional methods.

  16. Hepatic Blood Perfusion Estimated by Dynamic Contrast-Enhanced Computed Tomography in Pigs Limitations of the Slope Method

    PubMed Central

    Winterdahl, Michael; Sørensen, Michael; Keiding, Susanne; Mortensen, Frank V.; Alstrup, Aage K. O.; Hansen, Søren B.; Munk, Ole L.

    2012-01-01

    Objective To determine whether dynamic contrast-enhanced computed tomography (DCE-CT) and the slope method can provide absolute measures of hepatic blood perfusion from hepatic artery (HA) and portal vein (PV) at experimentally varied blood flow rates. Materials and Methods Ten anesthetized 40-kg pigs underwent DCE-CT during periods of normocapnia (normal flow), hypocapnia (decreased flow), and hypercapnia (increased flow), which was induced by adjusting the ventilation. Reference blood flows in HA and PV were measured continuously by surgically-placed ultrasound transit-time flowmeters. For each capnic condition, the DCE-CT estimated absolute hepatic blood perfusion from HA and PV were calculated using the slope method and compared with flowmeter based absolute measurements of hepatic perfusions and relative errors were analyzed. Results The relative errors (mean±SEM) of the DCE-CT based perfusion estimates were −21±23% for HA and 81±31% for PV (normocapnia), 9±23% for HA and 92±42% for PV (hypocapnia), and 64±28% for HA and −2±20% for PV (hypercapnia). The mean relative errors for HA were not significantly different from zero during hypo- and normocapnia, and the DCE-CT slope method could detect relative changes in HA perfusion between scans. Infusion of contrast agent led to significantly increased hepatic blood perfusion, which biased the PV perfusion estimates. Conclusions Using the DCE-CT slope method, HA perfusion estimates were accurate at low and normal flow rates whereas PV perfusion estimates were inaccurate and imprecise. At high flow rate, both HA perfusion estimates were significantly biased. PMID:22836307

  17. Sequential feline esophageal nutrient blood flow: perfusion measurements in vivo.

    PubMed

    Harell, G S; Anderson, M F; Bradley, B; Zboralske, F F

    1976-01-01

    The utilization of a catheter semiconductor beta detector (CASRAD) to perform in vivo, sequential, esophageal nutrient blood flow distribution studies in cats is described. A diffusable radioisotope, Rubidium 86 (86Rb), was injected intravenously and the CASRAD placed within the esophageal lumen. The distribution of 86Rb remained stable within the feline esophagus for sufficient time to allow for counting at 1.5 cm levels in the esophagus. The accuracy limitations of the CASRAD system were assessed by comparing the in vivo, recorded distribution of 86Rb with the esophageal distribution of 86Rb as determined by a well-type scintillation counter. The distribution throughout most of the esophagus was similar by both techniques. Sequential esophageal studies performed with the CASRAD showed less variability than existed in the biological differences between cats and the methodology of obtaining and counting tissue by well-type scintillation counter (mean coefficient of variation 11.6% versus coefficient of variation 23.1%).

  18. The effects of botulinum toxin type A on muscle blood perfusion and metabolism.

    PubMed

    Matic, Damir B; Lee, Ting Y; Wells, R Glenn; Gan, Bing S

    2007-12-01

    Botulinum toxin type A is approved by the U.S. Food and Drug Administration for the treatment of facial rhytides. However, the complete spectrum of action of botulinum toxin A has not yet been completely defined. Little is known about the metabolism of muscle after botulinum toxin A injection. This information may give insight into the additional effects botulinum toxin A may have on muscle. The authors assessed the influence of botulinum toxin A on the metabolism of muscle using dynamic investigative techniques. Twenty New Zealand White rabbits were divided into control, paralysis, and sham groups. Masseter muscle paralysis was achieved with botulinum toxin A. Dynamic computed tomographic and positron emission tomographic scans were obtained. Masseter muscle blood flow, blood volume, permeability surface, and mean transit time and glucose uptake were measured. Eighteen animals completed the study. Masseter blood perfusion showed consistent results across all parameters. Blood flow, blood volume, and permeability surface were significantly increased at weeks 4 and 8 on the paralyzed side. Mean transit time at week 4 was decreased on the paralyzed side. Positron emission tomographic scans showed that injected muscles in the botulinum toxin A group tended to have increased glucose uptake compared with untreated muscles. Botulinum toxin A injection increases muscle blood perfusion parameters and glucose uptake for a transient period. This increase is similar in duration to the known interval of botulinum toxin A-induced paralysis. These changes have been identified in a dynamic fashion and may represent changes in calcitonin gene-related peptide release.

  19. Influence of red blood cell aggregation on perfusion of an artificial microvascular network.

    PubMed

    Reinhart, Walter H; Piety, Nathaniel Z; Shevkoplyas, Sergey S

    2017-07-01

    RBCs suspended in plasma form multicellular aggregates under low-flow conditions, increasing apparent blood viscosity at low shear rates. It has previously been unclear, however, if RBC aggregation affects microvascular perfusion. Here, we analyzed the impact of RBC aggregation on perfusion and 'capillary' hematocrit in an AMVN at driving pressures ranging from 5 to 60 cm H2 O to determine if aggregation could improve tissue oxygenation. RBCs were suspended at 30% hematocrit in either 46.5 g/L dextran 40 (D40, non-aggregating medium) or 35 g/L dextran 70 (D70, aggregating medium) solutions with equal viscosity. Aggregation was readily observed in the AMVN for RBCs suspended in D70 at driving pressures ≤40 cm H2 O. The AMVN perfusion rate was the same for RBCs suspended in aggregating and non-aggregating medium, at both 'venular' and 'capillary' level. Estimated 'capillary' hematocrit was higher for D70 suspensions than for D40 suspensions at intermediate driving pressures (5-40 cm H2 O). We conclude that although RBC aggregation did not affect the AMVN perfusion rate independently of the driving pressure, a higher hematocrit in the 'capillaries' of the network for D70 suspensions suggested a better oxygen transport capacity in the presence of RBC aggregation. © 2016 John Wiley & Sons Ltd.

  20. [Changes in palmar skin blood flow, perfusion index and temperature during endoscopic thoracic sympathectomy].

    PubMed

    Asano, Maiko; Tanaka, Motoshige; Kusaka, Hitomi; Sakai, Masato; Minami, Toshiaki

    2010-12-01

    In endoscopic thoracic sympathectomy (ETS), it is required to perform accurate cautery of the sympathetic trunk. Monitoring of palmar skin blood flow and temperature has been used to assess the efficacy of ETS. This study investigated whether Perfusion Index (PI) is useful in assessing palmar skin blood flow and temperature in ETS. We studied 5 patients (1 man, 4 women) with palmar hyperhidrosis who had undergone a total of 10 ETS procedures. We measured skin blood flow, temperature and PI during ETS and evaluated the results. Significant correlations were found between increases in skin blood flow and PI after ETS in cases with the palmar skin temperature just before ETS of below 35 degrees C. In these cases, we can substitute increases in PI with increases in skin blood flow during ETS.

  1. Electrocardiogram frequency change by extracorporeal blood perfusion in a swine ventricular fibrillation model

    PubMed Central

    2013-01-01

    Background Extracorporeal cardiopulmonary resuscitation (ECPR) refers to the application of extracorporeal blood circulation with oxygenation as a resuscitation tool. The objective of this study is to observe the frequency component changes in the electrocardiogram (ECG) by ECPR during prolonged ventricular fibrillation (VF). Methods Six swine were prepared as a VF model. Extracorporeal blood circulation with a pulsatile blood pump and oxygenator was set up for the model. ECG signals were measured for 13 min during VF and analyzed using frequency analysis methods. The median frequency (MF), dominant frequency (DF), and amplitude spectrum area (AMSA) were calculated from a spectrogram obtained using short-time Fourier transform (STFT). Results MF decreased from 11 Hz at the start to 9 Hz at 2 min after VF and then increased to 11 Hz at 4.5 min after VF. DF started at 7 Hz and increased to 11 Hz within the first min and decreased to 9 Hz at 2 min, then increased to 12 Hz at 4.5 min after VF. Both frequency components decreased gradually from 4.5 min until 10 min after VF. After the oxygenated blood perfusion was initiated, both MF and DF increased remarkably and exceeded 12 and 14 Hz, respectively. Similarly, AMSA decreased gradually for the first 10 min, but increased remarkably and varied beyond 13 mV∙Hz after the oxygenated blood supply started. Remarkable frequency increases in ECG due to the oxygenated blood perfusion during ECPR were observed in the swine VF model. Conclusions The ECG frequency analysis during ECPR can give the resuscitation provider important information about the cardiac perfusion status and the appropriateness of the ECPR setup as well as the prediction of defibrillation success. PMID:24274395

  2. Validation of diffuse correlation spectroscopy for muscle blood flow with concurrent arterial spin labeled perfusion MRI

    NASA Astrophysics Data System (ADS)

    Yu, Guoqiang; Floyd, Thomas F.; Durduran, Turgut; Zhou, Chao; Wang, Jiongjiong; Detre, John A.; Yodh, Arjun G.

    2007-02-01

    Calf blood flow was measured simultaneously in healthy human subjects (n = 7) during cuff inflation and deflation using near-infrared diffuse correlation spectroscopy (DCS) and arterial spin labeled perfusion MRI (ASL-MRI). The DCS and ASL-MRI data exhibited highly correlated absolute and relative dynamic flow responses in each individual (p < 0.001). Peak flow variations during hyperemia were also significantly correlated, though more for relative (p = 0.003) than absolute (p = 0.016) flow. Repeated measurement variation was less than 8% for both modalities. The results provide much needed quantitative blood flow validation of the diffuse optical correlation method in humans.

  3. Effects of intestinal mucosal blood flow and motility on intestinal mucosa.

    PubMed

    Wang, Yan-Bin; Liu, Jing; Yang, Zhao-Xu

    2011-02-07

    To investigate the role of intestinal mucosal blood flow (IMBF) and motility in the damage of intestinal mucosal barrier in rats with traumatic brain injury. Sixty-four healthy male Wistar rats were divided randomly into two groups: traumatic brain injury (TBI) group (n=32), rats with traumatic brain injury; and control group (n=32), rats with sham-operation. Each group was divided into four subgroups (n=8) as 6, 12, 24 and 48 h after operation. Intestinal motility was measured by the propulsion ratio of a semi-solid colored marker (carbon-ink). IMBF was measured with the laser-Doppler technique. Endotoxin and D-xylose levels in plasma were measured to evaluate the change of intestinal mucosal barrier function following TBI. The level of endotoxin was significantly higher in TBI group than in the control group at each time point (0.382±0.014 EU/mL vs 0.102±0.007 EU/mL, 0.466±0.018 EU/mL vs 0.114±0.021 EU/mL, 0.478±0.029 EU/mL vs 0.112±0.018 EU/mL and 0.412±0.036 EU/mL vs 0.108±0.011 EU/mL, P<0.05). D-xylose concentrations in plasma in TBI group were significantly higher than in the control group (6.68±2.37 mmol/L vs 3.66±1.07 mmol/L, 8.51±2.69 mmol /L vs 3.15±0.95 mmol/L, 11.68±3.24 mmol/L vs 3.78±1.12 mmol/L and 10.23±2.83 mmol/L vs 3.34±1.23 mmol/ L, P<0.05). The IMBF in TBI group was significantly lower than that in the control group (38.5±2.8 PU vs 45.6±4.6 PU, 25.2±3.1 PU vs 48.2±5.3 PU, 21.5±2.7 PU vs 44.9±2.8 PU, 29. 4±3.8 PU vs 46.7±3.2 PU) (P<0.05). Significant decelerations of intestinal propulsion ratio in TBI groups were found compared with the control group (0.48%±0.06% vs 0.62%±0.03%, 0.37%±0.05% vs 0.64%±0.01%, 0.39%±0.07% vs 0.63%±0.05% and 0.46%±0.03% vs 0.65%±0.02%) (P<0.05). The intestinal mucosal permeability is increased obviously in TBI rats. Decrease of intestinal motility and IMBF occur early in TBI, both are important pathogenic factors for stress-related damage of the intestinal mucosal barrier in TBI.

  4. Investigation of source-detector separation optimization for an implantable perfusion and oxygenation sensor for liver blood vessels

    SciTech Connect

    Baba, Justin S; Akl, Tony; Cote, Gerard L.; Wilson, Mark A.; Ericson, Milton Nance

    2011-01-01

    An implanted system is being developed to monitor transplanted liver health during the critical 7-10 day period posttransplantation. The unit will monitor organ perfusion and oxygen consumption using optically-based probes placed on both the inflow and outflow blood vessels, and on the liver parenchymal surface. Sensing probes are based on a 3- wavelength LED source and a photodiode detector. Sample diffuse reflectance is measured at 735, 805, and 940 nm. To ascertain optimal source-to-photodetector spacing for perfusion measurement in blood vessels, an ex vivo study was conducted. In this work, a dye mixture simulating 80% blood oxygen saturation was developed and perfused through excised porcine arteries while collecting data for various preset probe source-to-photodetector spacings. The results from this study demonstrate a decrease in the optical signal with decreasing LED drive current and a reduction in perfusion index signal with increasing probe spacing. They also reveal a 2- to 4-mm optimal range for blood vessel perfusion probe source-to-photodetector spacing that allows for sufficient perfusion signal modulation depth with maximized signal to noise ratio (SNR). These findings are currently being applied to guide electronic configuration and probe placement for in vivo liver perfusion porcine model studies.

  5. Rectal Mucosal Microvascular Blood Supply Increase Is Associated with Colonic Neoplasia

    PubMed Central

    Gomes, Andrew J.; Roy, Hemant K.; Turzhitsky, Vladimir; Kim, Young; Rogers, Jeremy D.; Ruderman, Sarah; Stoyneva, Valentina; Goldberg, Michael J.; Bianchi, Laura K.; Yen, Eugene; Kromine, Alexey; Jameel, Mohammed; Backman, Vadim

    2009-01-01

    Purpose Endoscopic examination has proven effective in both detecting and preventing colorectal cancer; however, only about a quarter of eligible patients undergo screening. Even if the compliance rate increased, limited endoscopic capacity and cost would be prohibitive. There is a need for an accurate method to target colonoscopy to those most at risk of harboring colonic neoplasia. Exploiting field carcinogenesis seems to be a promising avenue. Our group recently reported that an early increase in blood supply (EIBS) is a reliable marker of field carcinogenesis in experimental models. We now investigate whether in situ detection of EIBS in the rectum can predict neoplasia elsewhere in the colon. Experimental Design We developed a novelpolarization-gated spectroscopy fiber-optic probe that allows depth-selective interrogation of microvascular blood content. Using the probe, we examined the blood content in vivo from the rectal mucosa of 216 patients undergoing screening colonoscopy. Results Microvascular blood content was increased by ~ 50% in the endoscopically normal rectal mucosa of patients harboring advanced adenomas when compared with neoplasia-free patients irrespective of lesion location. Demographic factors and nonneoplastic lesions did not confound this observation. Logistic regression using mucosal oxyhemoglobin concentration and patient age resulted in a sensitivity of 83%, a specificity of 82%, and an area under the receiver operating characteristic curve of 0.88 for the detection of advanced adenomas. Conclusions Increased microvascular blood supply in the normal rectal mucosa is associated with the presence of clinically significant neoplasia elsewhere in the colon, supporting the development of rectal EIBS as a colon cancer risk-stratification tool. PMID:19383816

  6. Cerebral blood flow is an earlier indicator of perfusion abnormalities than cerebral blood volume in Alzheimer's disease.

    PubMed

    Lacalle-Aurioles, María; Mateos-Pérez, José M; Guzmán-De-Villoria, Juan A; Olazarán, Javier; Cruz-Orduña, Isabel; Alemán-Gómez, Yasser; Martino, María-Elena; Desco, Manuel

    2014-04-01

    The purpose of this study was to elucidate whether cerebral blood flow (CBF) can better characterize perfusion abnormalities in predementia stages of Alzheimer's disease (AD) than cerebral blood volume (CBV) and whether cortical atrophy is more associated with decreased CBV or with decreased CBF. We compared measurements of CBV, CBF, and mean cortical thickness obtained from magnetic resonance images in a group of healthy controls, patients with mild cognitive impairment (MCI) who converted to AD after 2 years of clinical follow-up (MCI-c), and patients with mild AD. A significant decrease in perfusion was detected in the parietal lobes of the MCI-c patients with CBF parametric maps but not with CBV maps. In the MCI-c group, a negative correlation between CBF values and cortical thickness in the right parahippocampal gyrus suggests an increase in CBF that depends on cortical atrophy in predementia stages of AD. Our study also suggests that CBF deficits appear before CBV deficits in the progression of AD, as CBV abnormalities were only detected at the AD stage, whereas CBF changes were already detected in the MCI stage. These results confirm the hypothesis that CBF is a more sensitive parameter than CBV for perfusion abnormalities in MCI-c patients.

  7. Cerebral blood flow is an earlier indicator of perfusion abnormalities than cerebral blood volume in Alzheimer's disease

    PubMed Central

    Lacalle-Aurioles, María; Mateos-Pérez, José M; Guzmán-De-Villoria, Juan A; Olazarán, Javier; Cruz-Orduña, Isabel; Alemán-Gómez, Yasser; Martino, María-Elena; Desco, Manuel

    2014-01-01

    The purpose of this study was to elucidate whether cerebral blood flow (CBF) can better characterize perfusion abnormalities in predementia stages of Alzheimer's disease (AD) than cerebral blood volume (CBV) and whether cortical atrophy is more associated with decreased CBV or with decreased CBF. We compared measurements of CBV, CBF, and mean cortical thickness obtained from magnetic resonance images in a group of healthy controls, patients with mild cognitive impairment (MCI) who converted to AD after 2 years of clinical follow-up (MCI-c), and patients with mild AD. A significant decrease in perfusion was detected in the parietal lobes of the MCI-c patients with CBF parametric maps but not with CBV maps. In the MCI-c group, a negative correlation between CBF values and cortical thickness in the right parahippocampal gyrus suggests an increase in CBF that depends on cortical atrophy in predementia stages of AD. Our study also suggests that CBF deficits appear before CBV deficits in the progression of AD, as CBV abnormalities were only detected at the AD stage, whereas CBF changes were already detected in the MCI stage. These results confirm the hypothesis that CBF is a more sensitive parameter than CBV for perfusion abnormalities in MCI-c patients. PMID:24424381

  8. Laser speckle contrast imaging of skin blood perfusion responses induced by laser coagulation

    SciTech Connect

    Ogami, M; Kulkarni, R; Wang, H; Reif, R; Wang, R K

    2014-08-31

    We report application of laser speckle contrast imaging (LSCI), i.e., a fast imaging technique utilising backscattered light to distinguish such moving objects as red blood cells from such stationary objects as surrounding tissue, to localise skin injury. This imaging technique provides detailed information about the acute perfusion response after a blood vessel is occluded. In this study, a mouse ear model is used and pulsed laser coagulation serves as the method of occlusion. We have found that the downstream blood vessels lacked blood flow due to occlusion at the target site immediately after injury. Relative flow changes in nearby collaterals and anastomotic vessels have been approximated based on differences in intensity in the nearby collaterals and anastomoses. We have also estimated the density of the affected downstream vessels. Laser speckle contrast imaging is shown to be used for highresolution and fast-speed imaging for the skin microvasculature. It also allows direct visualisation of the blood perfusion response to injury, which may provide novel insights to the field of cutaneous wound healing. (laser biophotonics)

  9. Labetalol decreases cerebral perfusion pressure without negatively affecting cerebral blood flow in hypertensive gravidas.

    PubMed

    Belfort, Michael A; Tooke-Miller, Cathy; Allen, John C; Dizon-Townson, Donna; Varner, Michael A

    2002-01-01

    To research the cerebral hemodynamic effects of labetalol in pregnant women with hypertension. Prospective observational study. Tertiary Care Medical Center. Pregnant patients with hypertension. Transcranial Doppler (TCD) ultrasound was used to measure the blood velocity in the middle cerebral arteries (MCA) of eight pregnant patients with hypertension, before and after the administration of a 200 mg oral dose of labetalol. Five patients had severe preeclampsia, and three had chronic hypertension with superimposed preeclampsia. MCA blood velocity and systemic blood pressure were measured simultaneously at the baseline, and at 60 and 180 min after labetalol. Selected cerebral hemodynamic parameters were compared with normative curves. Values outside of the 5th and 95th percentiles were regarded as abnormal. Cerebral perfusion pressure (CPP), resistance area product (RAP), and cerebral flow index (CFI). Patient age, gestational age, and parity were similar to those of the normal women from whom the normative data were obtained. Women with hypertension had higher baseline CPP, MAP, and RAP than normal pregnant women, but their CFI was within the normal range. Labetalol reduced the CPP, as well as the systolic, diastolic, and mean BP significantly at 60 and 180 min without significantly affecting the heart rate, MCA velocities, RAP, or CFI. Labetalol effectively reduces CPP, without affecting cerebral perfusion, primarily by a decrease in systemic blood pressure. This makes it an ideal agent for blood pressure control in severely hypertensive pregnant women.

  10. Laser speckle contrast imaging of skin blood perfusion responses induced by laser coagulation

    NASA Astrophysics Data System (ADS)

    Ogami, M.; Kulkarni, R.; Wang, H.; Reif, R.; Wang, R. K.

    2014-08-01

    We report application of laser speckle contrast imaging (LSCI), i.e., a fast imaging technique utilising backscattered light to distinguish such moving objects as red blood cells from such stationary objects as surrounding tissue, to localise skin injury. This imaging technique provides detailed information about the acute perfusion response after a blood vessel is occluded. In this study, a mouse ear model is used and pulsed laser coagulation serves as the method of occlusion. We have found that the downstream blood vessels lacked blood flow due to occlusion at the target site immediately after injury. Relative flow changes in nearby collaterals and anastomotic vessels have been approximated based on differences in intensity in the nearby collaterals and anastomoses. We have also estimated the density of the affected downstream vessels. Laser speckle contrast imaging is shown to be used for highresolution and fast-speed imaging for the skin microvasculature. It also allows direct visualisation of the blood perfusion response to injury, which may provide novel insights to the field of cutaneous wound healing.

  11. Effects of shear forces and pressure on blood vessel function and metabolism in a perfusion bioreactor.

    PubMed

    Hoenicka, Markus; Wiedemann, Ludwig; Puehler, Thomas; Hirt, Stephan; Birnbaum, Dietrich E; Schmid, Christof

    2010-12-01

    Bovine saphenous veins (BSV) were incubated in a perfusion bioreactor to study vessel wall metabolism and wall structure under tissue engineering conditions. Group 1 vessels were perfused for 4 or 8 days. The viscosity of the medium was increased to that of blood in group 2. Group 3 vessels were additionally strained with luminal pressure. Groups 1-d through 3-d were similar except that BSV were endothelium-denuded before perfusion. Groups 1-a through 3-a used native vessels at elevated flow rates. Group 3 vessels responded significantly better to noradrenaline on day 4, whereas denuded vessels showed attenuated responses (p < 0.001). Tetrazolium dye reduction did not depend on perfusion conditions or time except for denuded vessels. pO₂ gradients across the vessels were independent of time and significantly higher in group 2 (p < 0.001). BSV converted glucose stoichiometrically to lactate except vessels of groups 3, 1-d, and 3-d which released more lactate than glucose could supply (p < 0.001). Group 1 vessels as well as all vessels perfused with elevated flow rates showed a loss of endothelial cells after 4 days, whereas group 2 and 3 vessels retained most of the endothelium. These data suggest that vessel metabolism was not limited by oxygen supply. Shear forces did not affect glucose metabolism but increased oxygen consumption and endothelial cell survival. Luminal pressure caused the utilization of energy sources other than glucose, as long as the endothelium was intact. Therefore, vessel metabolism needs to be monitored during tissue engineering procedures which challenge the constructs with mechanical stimuli.

  12. Cryotherapy-Induced Persistent Vasoconstriction After Cutaneous Cooling: Hysteresis Between Skin Temperature and Blood Perfusion.

    PubMed

    Khoshnevis, Sepideh; Craik, Natalie K; Matthew Brothers, R; Diller, Kenneth R

    2016-03-01

    The goal of this study was to investigate the persistence of cold-induced vasoconstriction following cessation of active skin-surface cooling. This study demonstrates a hysteresis effect that develops between skin temperature and blood perfusion during the cooling and subsequent rewarming period. An Arctic Ice cryotherapy unit (CTU) was applied to the knee region of six healthy subjects for 60 min of active cooling followed by 120 min of passive rewarming. Multiple laser Doppler flowmetry perfusion probes were used to measure skin blood flow (expressed as cutaneous vascular conductance (CVC)). Skin surface cooling produced a significant reduction in CVC (P < 0.001) that persisted throughout the duration of the rewarming period. In addition, there was a hysteresis effect between CVC and skin temperature during the cooling and subsequent rewarming cycle (P < 0.01). Mixed model regression (MMR) showed a significant difference in the slopes of the CVC-skin temperature curves during cooling and rewarming (P < 0.001). Piecewise regression was used to investigate the temperature thresholds for acceleration of CVC during the cooling and rewarming periods. The two thresholds were shown to be significantly different (P = 0.003). The results show that localized cooling causes significant vasoconstriction that continues beyond the active cooling period despite skin temperatures returning toward baseline values. The significant and persistent reduction in skin perfusion may contribute to nonfreezing cold injury (NFCI) associated with cryotherapy.

  13. Cryotherapy-Induced Persistent Vasoconstriction After Cutaneous Cooling: Hysteresis Between Skin Temperature and Blood Perfusion

    PubMed Central

    Khoshnevis, Sepideh; Craik, Natalie K.; Matthew Brothers, R.; Diller, Kenneth R.

    2016-01-01

    The goal of this study was to investigate the persistence of cold-induced vasoconstriction following cessation of active skin-surface cooling. This study demonstrates a hysteresis effect that develops between skin temperature and blood perfusion during the cooling and subsequent rewarming period. An Arctic Ice cryotherapy unit (CTU) was applied to the knee region of six healthy subjects for 60 min of active cooling followed by 120 min of passive rewarming. Multiple laser Doppler flowmetry perfusion probes were used to measure skin blood flow (expressed as cutaneous vascular conductance (CVC)). Skin surface cooling produced a significant reduction in CVC (P < 0.001) that persisted throughout the duration of the rewarming period. In addition, there was a hysteresis effect between CVC and skin temperature during the cooling and subsequent rewarming cycle (P < 0.01). Mixed model regression (MMR) showed a significant difference in the slopes of the CVC–skin temperature curves during cooling and rewarming (P < 0.001). Piecewise regression was used to investigate the temperature thresholds for acceleration of CVC during the cooling and rewarming periods. The two thresholds were shown to be significantly different (P = 0.003). The results show that localized cooling causes significant vasoconstriction that continues beyond the active cooling period despite skin temperatures returning toward baseline values. The significant and persistent reduction in skin perfusion may contribute to nonfreezing cold injury (NFCI) associated with cryotherapy. PMID:26632263

  14. Modulation of perfusion and oxygenation by red blood cell oxygen affinity during acute anemia.

    PubMed

    Cabrales, Pedro; Tsai, Amy G; Intaglietta, Marcos

    2008-03-01

    Responses to exchange transfusion using red blood cells (RBCs) with modified hemoglobin (Hb) oxygen (O(2)) affinity were studied in the hamster window chamber model during acute anemia to determine its role on microvascular perfusion and tissue oxygenation. Allosteric effectors were introduced in the RBCs by electroporation. Inositol hexaphosphate (IHP) and 5-hydroxymethyl-2-furfural (5HMF) were used to decrease and increase Hb-O(2) affinity. In vitro P50s (partial pressure of O(2) at 50% Hb saturation) were modified to 10, 25, 45, and 50 mm Hg (normal P50 is 32 mm Hg). Allosteric effectors also decreased the Hill coefficient. Anemic condition was induced by isovolemic hemodilution exchanges using 6% dextran 70 kD to 18% hematocrit (Hct). Modified RBCs (at 18% Hct in 5% albumin solution) were infused by exchange transfusion of 35% of blood volume. Systemic parameters, microvascular perfusion, capillary perfusion (functional capillary density, FCD), and microvascular Po(2) levels were measured. RBcs with P50 of 45 mm Hg increased tissue Po(2) and decreased O(2) delivery (Do(2)) and extraction (Vo(2)) and RBCs with P50 of 60 mmHg reduced FCD, microvascular flow, tissue Po(2), Do(2) and Vo(2). Erythrocytes with increased Hb-O(2) affinity maintained hemodynamic conditions, Do(2) and decreased tissue Po(2). This study shows that in an anemic condition, maximal tissue Po(2) does not correspond to maximal Do(2) and Vo(2).

  15. Longterm treatment with endothelin receptor antagonist bosentan and iloprost improves fingertip blood perfusion in systemic sclerosis.

    PubMed

    Cutolo, Maurizio; Ruaro, Barbara; Pizzorni, Carmen; Ravera, Francesca; Smith, Vanessa; Zampogna, Giuseppe; Paolino, Sabrina; Seriolo, Bruno; Cimmino, Marco; Sulli, Alberto

    2014-05-01

    To evaluate the longterm effects of endothelin-1 (ET-1) antagonism on peripheral blood perfusion (PBP) in patients with systemic sclerosis (SSc). Twenty-six patients with SSc already receiving cyclic intravenous iloprost (ILO) for severe Raynaud phenomenon were enrolled. Thirteen patients continued the treatment for a further 3 years (ILO group) and 13 patients, because of the appearance of digital ulcers, received in addition bosentan (BOS; 125 mg twice/day) for 3 years (ILO + BOS group). Both PBP at fingertips and nailfold microangiopathy were evaluated yearly by laser Doppler flowmetry and nailfold videocapillaroscopy, respectively. A progressive significant increase of PBP was observed in the ILO + BOS group during the 3 followup years (p = 0.0007, p = 0.0002, p = 0.01, respectively). In contrast, an insignificant progressive decrease of PBP was observed in the ILO group. Difference of perfusion between the PBP evaluations at basal temperature and at 36 °C (to test capillary dilation capacity), was found progressively decreased during the 3-year followup only in the ILO group (p = 0.05, p = 0.26, p = 0.09, respectively). A progressive increase of nailfold capillary number was observed only in the ILO + BOS group after 2 and 3 years of followup (p = 0.05). Longterm treatment of SSc patients with ET-1 antagonism, in combination with ILO, seems to increase fingertip blood perfusion, as well as both capillary dilation capacity and number.

  16. Mastication induces long-term increases in blood perfusion of the trigeminal principal nucleus.

    PubMed

    Viggiano, A; Manara, R; Conforti, R; Paccone, A; Secondulfo, C; Lorusso, L; Sbordone, L; Di Salle, F; Monda, M; Tedeschi, G; Esposito, F

    2015-12-17

    Understanding mechanisms for vessel tone regulation within the trigeminal nuclei is of great interest because some headache syndromes are due to dysregulation of such mechanisms. Previous experiments on animal models suggest that mastication may alter neuron metabolism and blood supply in these nuclei. To investigate this hypothesis in humans, arterial spin-labeling magnetic resonance imaging (MRI) was used to measure blood perfusion within the principal trigeminal nucleus (Vp) and in the dorsolateral-midbrain (DM, including the mesencephalic trigeminal nucleus) in healthy volunteers, before and immediately after a mastication exercise consisting of chewing a gum on one side of the mouth for 1 h at 1 bite/s. The side preference for masticating was evaluated with a chewing test and the volume of the masseter muscle was measured on T1-weighted MRI scans. The results demonstrated that the mastication exercise caused a perfusion increase within the Vp, but not in the DM. This change was correlated to the preference score for the side where the exercise took place. Moreover, the basal Vp perfusion was correlated to the masseter volume. These results indicate that the local vascular tone of the trigeminal nuclei can be constitutively altered by the chewing practice and by strong or sustained chewing.

  17. Design and testing of diffuse reflectance sensor for continuous monitoring of cutaneous blood perfusion

    NASA Astrophysics Data System (ADS)

    Zakharov, P.; Talary, M. S.; Caduff, A.

    2009-07-01

    A dual-wavelength reflectance optical sensor for monitoring cutaneous blood perfusion is presented as a part of multisensor glucose monitoring system. A Monte-Carlo simulation of partial differential pathlengths has been used for the optimization of the distance from light source to detector. The simulation indicated that the light pathlength within the upper vascularised skin layers increases before reaching saturation at separation distances larger than 3 mm. Thus the sensor sensitivity does not benefit from larger source-detector distances. At the same time with a higher separation of the detector from the source, the intensity exponentially decreases while undesirable sensitivity to the muscle perfusion increases. The hardware prototype has been developed based on the simulation findings and tested in a laboratory setting and in a home use study by patients with diabetes. For both testing procedures the optical sensor demonstrated high sensitivity to perfusion changes. The effect of initial cutaneous blood increase under the sensor has been observed which can be associated with pressure-induced vasodilation as a response to the sensor application.

  18. Increased brainstem perfusion, but no blood-brain barrier disruption, during attacks of migraine with aura.

    PubMed

    Hougaard, Anders; Amin, Faisal M; Christensen, Casper E; Younis, Samaira; Wolfram, Frauke; Cramer, Stig P; Larsson, Henrik B W; Ashina, Messoud

    2017-06-01

    See Moskowitz (doi:10.1093/brain/awx099) for a scientific commentary on this article.The migraine aura is characterized by transient focal cortical disturbances causing dramatic neurological symptoms that are usually followed by migraine headache. It is currently not understood how the aura symptoms are related to the headache phase of migraine. Animal studies suggest that cortical spreading depression, the likely mechanism of migraine aura, causes disruption of the blood-brain barrier and noxious stimulation of trigeminal afferents leading to activation of brainstem nuclei and triggering of migraine headache. We used the sensitive and validated technique of dynamic contrast-enhanced high-field magnetic resonance imaging to simultaneously investigate blood-brain barrier permeability and tissue perfusion in the brainstem (at the level of the lower pons), visual cortex, and brain areas of the anterior, middle and posterior circulation during spontaneous attacks of migraine with aura. Patients reported to our institution to undergo magnetic resonance imaging during the headache phase after presenting with typical visual aura. Nineteen patients were scanned during attacks and on an attack-free day. The mean time from attack onset to scanning was 7.6 h. We found increased brainstem perfusion bilaterally during migraine with aura attacks. Perfusion also increased in the visual cortex and posterior white matter following migraine aura. We found no increase in blood-brain barrier permeability in any of the investigated regions. There was no correlation between blood-brain barrier permeability, brain perfusion, and time from symptom onset to examination or pain intensity. Our findings demonstrate hyperperfusion in brainstem during the headache phase of migraine with aura, while the blood-brain barrier remains intact during attacks of migraine with aura. These data thus contradict the preclinical hypothesis of cortical spreading depression-induced blood-brain barrier

  19. Perfusion-diffusion compartmental models describe cerebral helium kinetics at high and low cerebral blood flows in sheep.

    PubMed

    Doolette, David J; Upton, Richard N; Grant, Cliff

    2005-03-01

    This study evaluated the relative importance of perfusion and diffusion mechanisms in compartmental models of blood:tissue helium exchange in the brain. Helium has different physiochemical properties from previously studied gases, and is a common diluent gas in underwater diving where decompression schedules are based on theoretical models of inert gas kinetics. Helium kinetics across the cerebrum were determined during and after 15 min of helium inhalation, at separate low and high steady states of cerebral blood flow in seven sheep under isoflurane anaesthesia. Helium concentrations in arterial and sagittal sinus venous blood were determined using gas chromatographic analysis, and sagittal sinus blood flow was monitored continuously. Parameters and model selection criteria of various perfusion-limited or perfusion-diffusion compartmental models of the brain were estimated by simultaneous fitting of the models to the sagittal sinus helium concentrations for both blood flow states. Purely perfusion-limited models fitted the data poorly. Models that allowed a diffusion-limited exchange of helium between a perfusion-limited tissue compartment and an unperfused deep compartment provided better overall fit of the data and credible parameter estimates. Fit to the data was also improved by allowing countercurrent diffusion shunt of helium between arterial and venous blood. These results suggest a role of diffusion in blood:tissue helium equilibration in brain.

  20. Magnetic resonance perfusion imaging of resting-state cerebral blood flow in preclinical Huntington's disease

    PubMed Central

    Wolf, Robert C; Grön, Georg; Sambataro, Fabio; Vasic, Nenad; Wolf, Nadine D; Thomann, Philipp A; Saft, Carsten; Landwehrmeyer, G Bernhard; Orth, Michael

    2011-01-01

    Magnetic resonance imaging (MRI) of the brain could be a powerful tool for discovering early biomarkers in clinically presymptomatic carriers of the Huntington's disease gene mutation (preHD). The aim of this study was to investigate the sensitivity of resting-state perfusion MRI in preHD and to identify neural changes, which could serve as biomarkers for future clinical trials. Differences in regional cerebral blood flow (rCBF) in 18 preHD and 18 controls were assessed with a novel MRI method based on perfusion images obtained with continuous arterial spin labeling. High-resolution structural data were collected to test for changes of brain volume. Compared with controls, preHD individuals showed decreased rCBF in medial and lateral prefrontal regions and increased rCBF in the precuneus. PreHD near to symptom onset additionally showed decreased rCBF in the putamen and increased rCBF in the hippocampus. Network analyses revealed an abnormal lateral prefrontal pattern in preHD far and near to motor onset. These data suggest early changes of frontostriatal baseline perfusion in preHD independent of substantial reductions of gray matter volume. This study also shows the feasibility of detecting neural changes in preHD with a robust MRI technique that would be suitable for longitudinal multisite application. PMID:21559028

  1. Relationship between caffeine-induced changes in resting cerebral perfusion and blood oxygenation level-dependent signal.

    PubMed

    Laurienti, Paul J; Field, Aaron S; Burdette, Jonathan H; Maldjian, Joseph A; Yen, Yi-Fen; Moody, Dixon M

    2003-09-01

    Recent interest has emerged in the use of pharmacologic methods to maximize blood oxygenation level-dependent (BOLD) signal intensity changes in functional MR imaging (fMRI). Adenosine antagonists, such as caffeine and theophylline, have been identified as potential agents for this purpose. The present study was designed to determine whether caffeine-induced decreases in cerebral perfusion result in enhanced BOLD responses to visual and auditory stimuli. MR imaging was used to measure resting cerebral perfusion and stimulus-induced BOLD signal intensity changes in 19 patients. We evaluated the relationship between resting cerebral perfusion and the magnitude of BOLD signal intensity induced by visual and auditory stimulation under caffeine and placebo conditions. The data showed that changes in resting cerebral perfusion produced by caffeine are not a consistent predictor of BOLD signal intensity magnitude. Although all cerebral perfusion was reduced in all study participants in response to caffeine, only 47% of the participants experienced BOLD signal intensity increase. This finding was independent of the participants' usual caffeine consumption. The data presented herein show that the relationship between resting cerebral perfusion and the magnitude of BOLD signal intensity is complex. It is not possible to consistently enhance BOLD signal intensity magnitude by decreasing resting perfusion with caffeine. Future studies aimed at evaluating the relationship between perfusion and BOLD signal intensity changes should seek a means to selectively modulate known components of the neural and vascular responses independently.

  2. Tumor volume, luxury perfusion, and regional blood volume changes in man visualized by subtraction computerized tomography.

    PubMed

    Penn, R D; Walser, R; Kurtz, D; Ackerman, L

    1976-04-01

    Computer and photographic methods for producing subtractions of computerized axial tomographic (CAT) scans have been developed. By subtracting point for point a normal scan from one taken after intravenous infusion of contrast material, a picture of the contrast in the cerebral vessels is created. By this method, tumor size and degree of vascularity may be assessed. Furthermore, abnormalities in perfusion and changes in blood volume due to mass effects and edema may be detected. Subtracting scans should add to the diagnostic potential of CAT and provide a noninvasive way to study vascular changes in cerebral disease.

  3. Evaluation of hemangiomas with technetium 99m-labeled RBCs: the perfusion-blood pool mismatch

    SciTech Connect

    Front, D.; Israel, O.; Joachims, H.; Brown, Y.; Eliachar, I.

    1983-03-18

    A case report is presented of a woman with a tumor mass in the nasopharynx. Early and delayed scintigraphy with Technetium 99m-labeled RBCs showed a large area of increased uptake which was later shown to be a hemangioma by contrast angiography. The perfusion-blood pool mismatch observed in hemangiomas is characteristic of these lesions and has not been described in any other abnormalities. The Tc-RBC using both early and delayed scintigraphy is a simple, noninvasive method for assessing the vascular characteristics of these tumors. (JMT)

  4. Adrenergic mechanism responsible for pathological alteration in gastric mucosal blood flow in rats with ulcer bleeding

    NASA Astrophysics Data System (ADS)

    Semyachkina-Glushkovskaya, O. V.; Pavlov, A. N.; Semyachkin-Glushkovskiy, I. A.; Gekalyuk, A. S.; Ulanova, M. V.; Lychagov, V. V.; Tuchin, V. V.

    2014-09-01

    The adrenergic system plays an important role in regulation of central and peripheral circulation in normal state and during hemorrhage. Because the impaired gastric mucosal blood flow (GMBF) is the major cause of gastroduodenal lesions, including ulcer bleeding (UB), we studied the adrenergic mechanism responsible for regulation of GMBF in rats with a model of stress-induced UB (SUB) using the laser Doppler flowmetry (LDF). First, we examined the effect of adrenaline on GMBF in rats under normal state and during UB. In all healthy animals the submucosal adrenaline injection caused a decrease in local GMBF. During UB the submucosal injection of adrenaline was accompanied by less pronounced GMBF suppression in 30,3% rats with SUB vs. healthy ones. In 69,7% rats with SUB we observed the increase in local GMBF after submucosal injection of adrenaline. Second, we studied the sensitivity of gastric β2-adrenoreceptors and the activity of two factors which are involved in β2-adrenomediated vasorelaxation-KATP -channels and NO. The effects of submucosal injection of isoproterenol, ICI118551 and glybenclamide on GMBF as well as NO levels in gastric tissue were significantly elevated in rats with SUB vs. healthy rats. Thus, our results indicate that high activation of gastric β2-adrenoreceptors associated with the increased vascular KATP -channels activity and elevated NO production is the important adrenergic mechanism implicated in the pathogenesis of UB.

  5. Effects of cold dry air nasal stimulation on airway mucosal blood flow in humans.

    PubMed

    Le Merre, C; Isber, J; Chediak, A D; Wanner, A

    2003-10-01

    Several studies have demonstrated that nasal challenges can induce reflex responses in the respiratory system. Some authors have described bronchoconstriction and modification of the pattern of breathing following nasal challenges by irritants and cold air. We propose to determine the effect of nasal stimulation with cold dry air on airway mucosal blood flow (Qaw) in the proximal tracheal bronchial tree of healthy humans. Nine healthy subjects participated in the study. Baseline measurement Qaw, nasal airway resistance (NAR) and airway caliber by specific airways conductance (SGaw) were followed by nasal challenge with cold dry air. Qaw, NAR and Sgaw were determined after the challenge. In those subjects in which a significant decline in Qaw was recorded the protocol was repeated after pretreatment with nasal anesthesia using topical lidocaine. Cold dry air challenge produced a significant decrease in mean Qaw for the nine subjects and this response was abolished by pretreatment with nasal anesthesia using topical lidocaine. There was no significant change in Sgaw and NAR after the challenge and topical lidocaine anesthesia. Our data indicates that nasal stimulation with cold dry air leads to a reduction in Qaw and that this effect may be mediated by a nasal reflex.

  6. Drug delivery in overcoming the blood-brain barrier: role of nasal mucosal grafting.

    PubMed

    Marianecci, Carlotta; Rinaldi, Federica; Hanieh, Patrizia Nadia; Di Marzio, Luisa; Paolino, Donatella; Carafa, Maria

    2017-01-01

    The blood-brain barrier (BBB) plays a fundamental role in protecting and maintaining the homeostasis of the brain. For this reason, drug delivery to the brain is much more difficult than that to other compartments of the body. In order to bypass or cross the BBB, many strategies have been developed: invasive techniques, such as temporary disruption of the BBB or direct intraventricular and intracerebral administration of the drug, as well as noninvasive techniques. Preliminary results, reported in the large number of studies on the potential strategies for brain delivery, are encouraging, but it is far too early to draw any conclusion about the actual use of these therapeutic approaches. Among the most recent, but still pioneering, approaches related to the nasal mucosa properties, the permeabilization of the BBB via nasal mucosal engrafting can offer new potential opportunities. It should be emphasized that this surgical procedure is quite invasive, but the implication for patient outcome needs to be compared to the gold standard of direct intracranial injection, and evaluated whilst keeping in mind that central nervous system diseases and lysosomal storage diseases are chronic and severely debilitating and that up to now no therapy seems to be completely successful.

  7. The effects of E and A prostaglandins on gastric mucosal blood flow and acid secretion in the rat

    PubMed Central

    Main, I. H. M.; Whittle, B. J. R.

    1973-01-01

    1. The effects of prostaglandins E1, E2, A1 and A2 on gastric acid secretion and mucosal blood flow were studied by means of a [14C]-aniline clearance technique in the anaesthetized rat. 2. During intravenous administration of these prostaglandins, in doses which almost completely inhibited pentagastrin- and histamine-induced acid secretion, a fall in clearance was observed. 3. Clearance per unit acid secretion increased during prostaglandin administration, precluding a primary reduction in mucosal blood flow as the mechanism of the antisecretory action. 4. Prostaglandins increased clearance during basal secretion, indicating a direct vasodilator effect on the gastric mucosa. 5. The possibility that endogenous prostaglandins contribute to functional vasodilatation in the gastric mucosa and that exogenous prostaglandins may be of clinical value in the treatment of peptic ulcer is discussed. PMID:4149696

  8. Insulin resistance is associated with lower arterial blood flow and reduced cortical perfusion in cognitively asymptomatic middle-aged adults.

    PubMed

    Hoscheidt, Siobhan M; Kellawan, J Mikhail; Berman, Sara E; Rivera-Rivera, Leonardo A; Krause, Rachel A; Oh, Jennifer M; Beeri, Michal S; Rowley, Howard A; Wieben, Oliver; Carlsson, Cynthia M; Asthana, Sanjay; Johnson, Sterling C; Schrage, William G; Bendlin, Barbara B

    2016-01-01

    Insulin resistance (IR) is associated with poor cerebrovascular health and increased risk for dementia. Little is known about the unique effect of IR on both micro- and macrovascular flow particularly in midlife when interventions against dementia may be most effective. We examined the effect of IR as indexed by the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) on cerebral blood flow in macro- and microvessels utilizing magnetic resonance imaging (MRI) among cognitively asymptomatic middle-aged individuals. We hypothesized that higher HOMA-IR would be associated with reduced flow in macrovessels and lower cortical perfusion. One hundred and twenty cognitively asymptomatic middle-aged adults (57 ± 5 yrs) underwent fasting blood draw, phase contrast-vastly undersampled isotropic projection reconstruction (PC VIPR) MRI, and arterial spin labeling (ASL) perfusion. Higher HOMA-IR was associated with lower arterial blood flow, particularly within the internal carotid arteries (ICAs), and lower cerebral perfusion in several brain regions including frontal and temporal lobe regions. Higher blood flow in bilateral ICAs predicted greater cortical perfusion in individuals with lower HOMA-IR, a relationship not observed among those with higher HOMA-IR. Findings provide novel evidence for an uncoupling of macrovascular blood flow and microvascular perfusion among individuals with higher IR in midlife.

  9. The complex interaction between ocular perfusion pressure and ocular blood flow - relevance for glaucoma.

    PubMed

    Schmidl, Doreen; Garhofer, Gerhard; Schmetterer, Leopold

    2011-08-01

    Glaucoma is an optic neuropathy of unknown origin. The most important risk factor for the disease is an increased intraocular pressure (IOP). Reducing IOP is associated with reduced progression in glaucoma. Several recent large scale trials have indicated that low ocular perfusion pressure (OPP) is a risk factor for the incidence, prevalence and progression of the disease. This is a strong indicator that vascular factors are involved in the pathogenesis of the disease, a hypothesis that was formulated 150 years ago. The relation between OPP and blood flow to the posterior pole of the eye is, however, complex, because of a phenomenon called autoregulation. Autoregulatory processes attempt to keep blood flow constant despite changes in OPP. Although autoregulation has been observed in many experiments in the ocular vasculature the mechanisms underlying the vasodilator and vasoconstrictor responses in face of changes in OPP remain largely unknown. There is, however, recent evidence that the human choroid regulates its blood flow better during changes in blood pressure induced by isometric exercise than during changes in IOP induced by a suction cup. This may have consequences for our understanding of glaucoma, because it indicates that blood flow regulation is strongly dependent not only on OPP, but also on the level of IOP itself. Indeed there is data indicating that reduction of IOP by pharmacological intervention improves optic nerve head blood flow regulation independently of an ocular vasodilator effect.

  10. Blood Perfusion in Microfluidic Models of Pulmonary Capillary Networks: Role of Geometry and Hematocrit

    NASA Astrophysics Data System (ADS)

    Stauber, Hagit; Waisman, Dan; Sznitman, Josue; Technion-IIT Team; Department of Neonatology Carmel Medical Center; Faculty of Medicine-Technion IIT Collaboration

    2015-11-01

    Microfluidic platforms are increasingly used to study blood microflows at true physiological scale due to their ability to overcome manufacturing obstacle of complex anatomical morphologies, such as the organ-specific architectures of the microcirculation. In the present work, we utilize microfluidic platforms to devise in vitro models of the underlying pulmonary capillary networks (PCN), where capillary lengths and diameters are similar to the size of RBCs (~ 5-10 μm). To better understand flow characteristics and dispersion of red blood cells (RBCs) in PCNs, we have designed microfluidic models of alveolar capillary beds inspired by the seminal ``sheet flow'' model of Fung and Sobin (1969). Our microfluidic PCNs feature confined arrays of staggered pillars with diameters of ~ 5,7 and 10 μm, mimicking the dense structure of pulmonary capillary meshes. The devices are perfused with suspensions of RBCs at varying hematocrit levels under different flow rates. Whole-field velocity patterns using micro-PIV and single-cell tracking using PTV are obtained with fluorescently-labelled RBCs and discussed. Our experiments deliver a real-scale quantitative description of RBC perfusion characteristics across the pulmonary capillary microcirculation.

  11. Quantifying Single Microvessel Permeability in Isolated Blood-perfused Rat Lung Preparation

    PubMed Central

    Kandasamy, Kathirvel; Parthasarathi, Kaushik

    2014-01-01

    The isolated blood-perfused lung preparation is widely used to visualize and define signaling in single microvessels. By coupling this preparation with real time imaging, it becomes feasible to determine permeability changes in individual pulmonary microvessels. Herein we describe steps to isolate rat lungs and perfuse them with autologous blood. Then, we outline steps to infuse fluorophores or agents via a microcatheter into a small lung region. Using these procedures described, we determined permeability increases in rat lung microvessels in response to infusions of bacterial lipopolysaccharide. The data revealed that lipopolysaccharide increased fluid leak across both venular and capillary microvessel segments. Thus, this method makes it possible to compare permeability responses among vascular segments and thus, define any heterogeneity in the response. While commonly used methods to define lung permeability require postprocessing of lung tissue samples, the use of real time imaging obviates this requirement as evident from the present method. Thus, the isolated lung preparation combined with real time imaging offers several advantages over traditional methods to determine lung microvascular permeability, yet is a straightforward method to develop and implement. PMID:25045895

  12. Comparable Cerebral Blood Flow in Both Hemispheres During Regional Cerebral Perfusion in Infant Aortic Arch Surgery.

    PubMed

    Rüffer, André; Tischer, Philip; Münch, Frank; Purbojo, Ariawan; Toka, Okan; Rascher, Wolfgang; Cesnjevar, Robert Anton; Jüngert, Jörg

    2017-01-01

    Cerebral protection during aortic arch repair can be provided by regional cerebral perfusion (RCP) through the innominate artery. This study addresses the question of an adequate bilateral blood flow in both hemispheres during RCP. Fourteen infants (median age 11 days [range, 3 to 108]; median weight, 3.6 kg [range, 2.8 to 6.0 kg]) undergoing RCP (flow rate 54 to 60 mL · kg(-1) · min(-1)) were prospectively included. Using combined transfontanellar/transtemporal two- and three-dimensional power/color Doppler sonography, cerebral blood flow intensity in the main cerebral vessels was displayed. Mean time average velocities were measured with combined pulse-wave Doppler in the basilar artery, and both sides of the internal carotid, anterior, and medial cerebral arteries. In addition, bifrontal regional cerebral oximetry (rSO2) was assessed. Comparing both hemispheres, measurements were performed at target temperature (28°C) during full-flow total body perfusion (TBP) and RCP. A regular circle of Willis with near-symmetric blood flow intensity to both hemispheres was visualized in all infants during both RCP and TBP. In the left internal carotid artery, blood flow direction was mixed (retrograde, n = 5; antegrade, n = 8) during TBP and retrograde during RCP. Comparison between sides showed comparable cerebral time average velocities and rSO2, except for higher time average velocities in the right internal carotid artery (TBP p = 0.019, RCP p = 0.09). Unilateral comparison between perfusion methods revealed significantly higher rSO2 in the right hemisphere during TBP (82% ± 9%) compared with RCP (74% ± 11%, p = 0.036). Bilateral assessment of cerebral rSO2 and time average velocity in the main great cerebral vessels suggests that RCP is associated with near-symmetric blood flow intensity to both hemispheres. Further neurodevelopmental studies are necessary to verify RCP for neuroprotection during aortic arch repair. Copyright © 2017 The Society of Thoracic

  13. 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

  14. Do you mind if I vape? Immediate effects of electronic cigarettes on perfusion in buccal mucosal tissue--a pilot study.

    PubMed

    Reuther, William J; Hale, Beverley; Matharu, Jas; Blythe, John N; Brennan, Peter A

    2016-04-01

    The association between smoking and postoperative complications is compounded in patients who have oral and maxillofacial operations by an additional local effect, and patients often continue to smoke after operation despite advice to stop. Recent studies have suggested that nicotine may reduce inflammation and improve angiogenesis, so topical application may be beneficial for smokers. The electronic cigarette is increasing in popularity and more patients ask whether they can vape after operation. We investigated the effect of electronic cigarettes (of which half contained nicotine and half did not) on blood flow in the buccal mucosa in 10 volunteers immediately after vaping. Smokers were excluded as this was considered an additional variable in a small pilot study and our Trust has a no-smoking policy. After vaping for 5 minutes, capillary blood flow was measured in the buccal mucosa at 5-minute intervals using a laser Doppler probe, and the results were expressed as arbitrary perfusion units. There was a wide variation in results and a small but significant rise (p=0.008) as a result of nicotine vaping, but these fell to the same levels as before within 30 minutes. Electronic cigarettes may have an effect on blood flow to the oral mucosa, although further studies are needed to show whether they improve healing time after operation. Additional work is also needed to compare them with cigarettes.

  15. Paeonol Protects Rat Heart by Improving Regional Blood Perfusion during No-Reflow

    PubMed Central

    Ma, Lina; Chuang, Chia-Chen; Weng, Weiliang; Zhao, Le; Zheng, Yongqiu; Zhang, Jinyan; Zuo, Li

    2016-01-01

    No-reflow phenomenon, defined as inadequate perfusion of myocardium without evident artery obstruction, occurs at a high incidence after coronary revascularization. The mechanisms underlying no-reflow is only partially understood. It is commonly caused by the swelling of endothelial cells, neutrophil accumulation, and vasoconstriction, which are all related to acute inflammation. Persistent no-reflow can lead to hospitalization and mortality. However, an effective preventive intervention has not yet been established. We have previously found that paeonol, an active extraction from the root of Paeonia suffruticosa, can benefit the heart function by inhibiting tissue damage after ischemia, reducing inflammation, and inducing vasodilatation. To further investigate the potential cardioprotective action of paeonol on no-reflow, healthy male Wistar rats were randomly divided into four groups: sham, ischemia-reperfusion (I/R) injury (left anterior descending coronary artery was ligated for 4 h followed by reperfusion for 8 h), and I/R injury pretreated with paeonol at two different doses. Real-time myocardial contrast echocardiography was used to monitor regional blood perfusion and cardiac functions. Our data indicated that paeonol treatment significantly reduces myocardial infarct area and no-reflow area (n = 8; p < 0.05). Regional myocardial perfusion (A·β) and cardiac functions such as ejection fraction, stroke volume, and fractional shortening were elevated by paeonol (n = 8; p < 0.05). Paeonol also lowered the serum levels of lactate dehydrogenase, creatine kinase, cardiac troponin T, and C-reactive protein, as indices of myocardial injury. Paeonol exerts beneficial effects on attenuating I/R-associated no-reflow injuries, and may be considered as a potential preventive treatment for cardiac diseases or post-coronary revascularization in which no-reflow often occurs. PMID:27493631

  16. Multislice Analysis of Blood Flow Values in CT Perfusion Studies of Lung Cancer

    PubMed Central

    Malavasi, Silvia; Barone, Domenico; Gavelli, Giampaolo

    2017-01-01

    Objectives. Tumour heterogeneity represents a key issue in CT perfusion (CTp), where all studies are usually based on global mean or median values of perfusion maps, often computed on whole tumour. We sought to determine whether, and to what extent, such global values can be representative of tumour heterogeneity, with respect to single slices, and could be used for therapy assessment. Materials and Methods. Twelve patients with one primary non-small cell lung cancer lesion were enrolled in this study, for a total amount of 26 CTp examinations and 118 slices. Mean and median blood flow (BF) values, calculated voxel-based, were computed on each slice and the whole tumour. To measure functional heterogeneity, entropy was calculated on BF values as well. Results. Most of the slices were not represented by the global BF values computed on the whole tumour. In addition, there are a number of lesions having equivalent global BF values, but they are composed of slices having very different heterogeneity distributions, that is, entropy values. Conclusions. Global mean/median BF values of the single slices separately should be considered for clinical assessment, only if interpreted through entropy computed on BF values. The numerical equivalence between global BF values of different lesions may correspond to different clinical status, thus inducing possible errors in choice of therapy when considering global values only. PMID:28164118

  17. Cerebral blood volume imaging by flat detector computed tomography in comparison to conventional multislice perfusion CT.

    PubMed

    Struffert, Tobias; Deuerling-Zheng, Yu; Kloska, Stephan; Engelhorn, Tobias; Boese, Jan; Zellerhoff, Michael; Schwab, Stefan; Doerfler, Arnd

    2011-04-01

    We tested the hypothesis that Flat Detector computed tomography (FD-CT) with intravenous contrast medium would allow the calculation of whole brain cerebral blood volume (CBV) mapping (FD-CBV) and would correlate with multislice Perfusion CT (PCT). Twenty five patients were investigated with FD-CBV and PCT. Correlation of the CBV maps of both techniques was carried out with measurements from six anatomical regions from both sides of the brain. Mean values of each region and the correlation coefficient were calculated. Bland-Altman analysis was performed to compare the two different imaging techniques. The image and data quality of both PCT and FD-CBV were suitable for evaluation in all patients. The mean CBV values of FD-CBV and PCT showed only minimal differences with overlapping standard deviation. The correlation coefficient was 0.79 (p < 0.01). Bland-Altman analysis showed a mean difference of -0.077 ± 0.48 ml/100 g between FD-CBV and PCT CBV measurements, indicating that FD-CBV values were only slightly lower than those of PCT. CBV mapping with intravenous contrast medium using Flat Detector CT compared favourably with multislice PCT. The ability to assess cerebral perfusion within the angiographic suite may improve the management of ischaemic stroke and evaluation of the efficacy of dedicated therapies.

  18. Quantification of blood perfusion using 3D power Doppler: an in-vitro flow phantom study

    NASA Astrophysics Data System (ADS)

    Raine-Fenning, N. J.; Ramnarine, K. V.; Nordin, N. M.; Campbell, B. K.

    2004-01-01

    Three-dimensional (3D) power Doppler data is increasingly used to assess and quantify blood flow and tissue perfusion. The objective of this study was to assess the validity of common 3D power Doppler ‘vascularity’ indices by quantification in well characterised in-vitro flow models. A computer driven gear pump was used to circulate a steady flow of a blood mimicking fluid through various well characterised flow phantoms to investigate the effect of the number of flow channels, flow rate, depth dependent tissue attenuation, blood mimic scatter particle concentration and ultrasound settings. 3D Power Doppler data were acquired with a Voluson 530D scanner and 7.5 MHz transvaginal transducer (GE Kretz). Virtual Organ Computer-aided Analysis software (VOCAL) was used to quantify the vascularisation index (VI), flow index (FI) and vascularisation-flow index (VFI). The vascular indices were affected by many factors, some intuitive and some with more complex or unexpected relationships (e.g. VI increased linearly with an increase in flow rate, blood mimic scatter particle concentration and number of flow channels, and had a complex dependence on pulse repetition frequency). Use of standardised settings and appropriate calibration are required in any attempt at relating ‘vascularity indices’ with flow.

  19. Tissue perfusion in neonates undergoing open-heart surgery using autologous umbilical cord blood or donor blood components.

    PubMed

    Chasovskyi, K; Fedevych, O; McMullan, D M; Mykychak, Y; Vorobiova, G; Zhovnir, V; Yemets, I

    2015-09-01

    This study evaluates the hemoglobin-oxygen relationship and tissue perfusion during cardiopulmonary bypass (CPB) in neonates undergoing open-heart surgery using autologous umbilical cord blood or donor blood components. We compared perioperative hematocrit (Hct), fetal hemoglobin (HbF), p(50)O(2), pH, pCO(2), serum lactate, duration of mechanical ventilation and intensive care unit (ICU) length of stay in neonates undergoing open-heart surgery using autologous umbilical cord blood (Group I, N=45) or donor blood components (Group II, N=65). The groups were similar with respect to diagnosis, weight, type of procedure, duration of CPB and duration of myocardial ischemia. Mean p(50)O(2) was significantly lower in Group I during CPB (19.7 vs. 22.3 mmHg, p=0.004) and at the end of CPB (20.1 vs. 22.8 mmHg, p=0.003). Median peak lactate during CPB was higher in Group I (4.8 vs. 2.2 mmol/l, p<0.001). Carbon dioxide tension was identified as an independent predictor of higher p(50)O(2) during CPB in Group I (β=0.88, p=0.002), but not Group II. Bodyweight, Hct, duration of CPB, pre-CPB lactate level and pCO(2) affected peak lactate level during CPB. Although mean duration of ventilation was longer in Group II (mean 51 vs. 43, p=0.004), the groups experienced similar duration of ICU stay (5.8 vs. 5.9 days, p=0.280). Despite the fact that the oxyhemoglobin dissociation curve is shifted leftward in patients who receive autologous umbilical cord blood, tissue oxygen delivery appears to be preserved in neonates who undergo open-heart surgery using autologous umbilical cord blood. © The Author(s) 2014.

  20. An original versatile nonocclusive pressure-regulated blood roller pump for extracorporeal perfusion.

    PubMed

    Durandy, Yves; Wang, Shigang; Ündar, Akif

    2014-06-01

    Currently, only a small number of centrifugal pumps are being used for hemodynamic and/or respiratory support, but all of them have limitations. This article aims to present the Rhône-Poulenc 06 nonocclusive pressure-regulated blood pump. This pump was developed in France in the 1970s and used for decades in perfusion for cardiopulmonary bypass procedures, cardiac or lung assist as well as venovenous bypass during liver transplant. The intrinsic properties of this pump allowed us to describe a new technique for extracorporeal lung support in the 1980s, using a single cannula tidal flow venovenous bypass. This pump compared favorably with conventional pumps in terms of flow and pressure, hemolysis, pulsatility, safety, and cost-effectiveness. We believe that this simple pump could be an alternative to more sophisticated and expensive devices.

  1. Application of near-infrared spectroscopy in monitoring blood perfusion in digital replantation

    NASA Astrophysics Data System (ADS)

    Mao, Jian-Min; Wright, Leigh P.; Elmandjra, Mohamed

    2005-04-01

    Using a near-infrared optical device developed by ViOptix, Inc., a clinical study on post-operative non-invasive monitoring of finger blood perfusion has been conducted for 48 patients undergoing digital replantation at the California Pacific Medical Center. The study showed that non-survival digits have their tissue oxygen saturation (StO2) values significantly lower than those for the controls in general, but survival digits did not. Further, the StO2 values can be used to define a survival index, in terms of which a digit survival criterion was tentatively suggested. Applying the criterion to the 64 digits (with 3 of them non-survival) involved in the clinical study, the sensitivity and the specificity were high. Therefore the device may have potential to be used in post-operative monitoring for digit replantation.

  2. Cerebral blood flow imaging in arteriovenous malformation complicated by normal perfusion pressure breakthrough.

    PubMed

    Ogasawara, K; Yoshida, K; Otawara, Y; Kobayashi, M; Yasuda, S; Doi, M; Ogawa, A

    2001-12-01

    A patient with normal perfusion pressure breakthrough (NPPB) after surgical removal of an arteriovenous malformation (AVM) was evaluated using single photon emission computed tomography cerebral blood flow (CBF) imaging. A 48-year-old man suffered consciousness disturbance because of an intraventricular hemorrhage and underwent ventricular drainage. Cerebral angiography showed a medium-sized AVM in the left parietal lobe. Three months after the ictus, a left parietal craniotomy was performed and total removal of the AVM was achieved. A brain region adjacent to the AVM with preoperative decreased vasoreactivity to acetazolamide showed marked hyperperfusion after AVM excision. Hemorrhage subsequently occurred in this area. CBF mapping seems to offer a noninvasive method for the preoperative identification of AVM patients at risk for NPPB, and to allow for early postoperative diagnosis of NPPB.

  3. Effects of permanent magnets on resting skin blood perfusion in healthy persons assessed by laser Doppler flowmetry and imaging.

    PubMed

    Mayrovitz, H N; Groseclose, E E; Markov, M; Pilla, A A

    2001-10-01

    Effects on skin blood perfusion of permanent ceramic magnets [0.1 T (1000 G) surface field], individually (disk shaped, 4 cm diameter x 1 cm thick) or in the form of a 11 x 7 in pad ( approximately 28 x 17.8 cm) with an array of 16 rectangular magnets (4.5 x 2.2 cm), were investigated in 16 female volunteers (27.4 +/- 1.7 years, range 21-48 years) using three separate protocols. In protocol A, a disk magnet was placed on the palmar surface of the hand in contact with the thenar eminence (n = 5). In protocol B, the magnet was placed on the hand dorsum overlying the thenar eminence (n = 5). In protocol C, the entire palm and fingers rested on the magnetic pad (n = 6). Magnets were in place for 36 min on one hand, and a sham was in place on the other hand. Blood perfusion was measured on the middle finger dorsum by laser Doppler flowmetry (LDF) and on the index finger by laser Doppler imaging (LDI). Perfusion measurements were simultaneously taken in sham and magnet exposed hands, before and during the entire magnet exposure interval. Magnetic field effects were tested by comparing skin blood perfusion sequences in magnet and sham exposed regions. Results showed no significant changes in either LDF or LDI perfusion at magnet or sham sites during exposure, nor were there any significant differences between sham and magnet sites for any protocol. Measurements of skin temperature at the LDF measurement sites also showed no significant change. It is concluded that in the healthy subjects studied with normal, unstressed circulation, magnets of the type and for the duration used, showed no detectible effect on skin blood perfusion in the anatomical area studied.

  4. Blood perfusion of the contralateral testis evaluated with contrast-enhanced ultrasound in rabbits with unilateral testicular torsion.

    PubMed

    Chen, Lin; Zhan, Wei-Wei; Shen, Zhou-Jun; Rui, Wen-Bin; Lv, Chen; Chen, Man; Zhou, Jian-Qiao; Zhou, Ping; Zhou, Mi; Zhu, Ying

    2009-03-01

    The changes of blood perfusion of contralateral testis after unilateral testicular torsion remain controversial. In this study, 28 New Zealand white male rabbits were randomly divided into five groups. Group A (n = 8), the control group, underwent a sham operation on the unilateral testis without inducing testicular torsion. In groups B, C, and D (n = 5 each), unilateral testicular torsion was induced, and, after 3, 6 or 24 h, respectively, detorsion was performed. In group E (n = 5), permanent unilateral testicular torsion was applied. Contrast-enhanced ultrasound was used to observe the blood perfusion of the contralateral testis at the following stages: pre-torsion (preopration), immediately post-torsion (postopration), pre-detorsion, immediately post-detorsion, and late-stage post-detorsion (6-12 h post-detorsion in groups B-D) or at a similar time point (15-21 h post-torsion in group E). Time-intensity curves were generated, and the following parameters were derived and analyzed: arrival time, time to peak intensity, peak intensity, and half-time of the descending peak intensity. The analysis revealed that blood perfusion of the contralateral testis increased immediately after testicular torsion on the opposite side (P < 0.05), which increased with prolonged testicular torsion of the other testis. This research demonstrated that contrast-enhanced ultrasound was valuable in evaluating blood perfusion of the contralateral testis after unilateral testicular torsion.

  5. Spatio-temporal cerebral blood flow perfusion patterns in cortical spreading depression

    NASA Astrophysics Data System (ADS)

    Verisokin, Andrey Yu.; Verveyko, Darya V.; Postnov, Dmitry E.

    2017-04-01

    Cortical spreading depression (CSD) is an example of one of the most common abnormalities in biophysical brain functioning. Despite the fact that there are many mathematical models describing the cortical spreading depression (CSD), most of them do not take into consideration the role of redistribution of cerebral blood flow (CBF), that results in the formation of spatio-temporal patterns. The paper presents a mathematical model, which successfully explains the CBD role in the CSD process. Numerical study of this model has revealed the formation of stationary dissipative structures, visually analogous to Turing structures. However, the mechanism of their formation is not diffusion. We show these structures occur due to another type of spatial coupling, that is related to tissue perfusion rate. The proposed model predicts that at similar state of neurons the distribution of blood flow and oxygenation may by different. Currently, this effect is not taken into account when the Blood oxygen-level dependent (BOLD) contrast imaging used in functional magnetic resonance imaging (fMRI). Thus, the diagnosis on the BOLD signal can be ambiguous. We believe that our results can be used in the future for a more correct interpretation of the data obtained with fMRI, NIRS and other similar methods for research of the brain activity.

  6. Perfusion-weighted imaging and dynamic 4D angiograms for the estimation of collateral blood flow in lacunar infarction.

    PubMed

    Förster, Alex; Mürle, Bettina; Böhme, Johannes; Al-Zghloul, Mansour; Kerl, Hans U; Wenz, Holger; Groden, Christoph

    2016-10-01

    Although lacunar infarction accounts for approximately 25% of ischemic strokes, collateral blood flow through anastomoses is not well evaluated in lacunar infarction. In 111 lacunar infarction patients, we analyzed diffusion-weighted images, perfusion-weighted images, and blood flow on dynamic four-dimensional angiograms generated by use of Signal Processing In NMR-Software. Blood flow was classified as absent (type 1), from periphery to center (type 2), from center to periphery (type 3), and combination of type 2 and 3 (type 4). On diffusion-weighted images, lacunar infarction was found in the basal ganglia (11.7%), internal capsule (24.3%), corona radiata (30.6%), thalamus (24.3%), and brainstem (9.0%). In 58 (52.2%) patients, perfusion-weighted image showed a circumscribed hypoperfusion, in one (0.9%) a circumscribed hyperperfusion, whereas the remainder was normal. In 36 (62.1%) patients, a larger perfusion deficit (>7 mm) was observed. In these, blood flow was classified type 1 in four (11.1%), 2 in 17 (47.2%), 3 in 9 (25.0%), and 4 in six (16.7%) patients. Patients with lacunar infarction in the posterior circulation more often demonstrated blood flow type 2 and less often type 3 (p = 0.01). Detailed examination and graduation of blood flow in lacunar infarction by use of dynamic four-dimensional angiograms is feasible and may serve for a better characterization of this stroke subtype.

  7. Acute baclofen diminishes resting baseline blood flow to limbic structures: A perfusion fMRI study

    PubMed Central

    Franklin, Teresa R.; Shin, Joshua; Jagannathan, Kanchana; Suh, Jesse J.; Detre, John A.; O’Brien, Charles P.; Childress, Anna Rose

    2012-01-01

    Background Preclinical and clinical evidence show that the GABA B agonist, baclofen is a promising treatment for addictive disorders; however, until recently its mechanism of action in the human brain was unknown. In previous work we utilized a laboratory model that included a medication versus placebo regimen to examine baclofen’s actions on brain circuitry. Perfusion fMRI [measure of cerebral blood flow (CBF)] data acquired ‘at rest’ before and on the last day of the 21-day medication regimen showed that baclofen diminished CBF bilaterally in the VS, insula and medial orbitofrontal cortex (mOFC). In the present study, we hypothesized that a single dose of baclofen would have effects similar to repeated dosing. Methods To test our hypothesis, in a crossover design, CBF data were acquired using pseudo continuous arterial spin labeled (pCASL) perfusion fMRI. Subjects were either un-medicated or were administered a 20 mg dose of baclofen approximately 110 min prior to scanning. Results Acute baclofen diminished mOFC, amygdala, and ventral anterior insula CBF without causing sedation (family-wise error corrected at p = 0.001). Conclusions Results demonstrate that similar to repeated dosing, an acute dose of baclofen blunts the ‘limbic’ substrate that is hyper-responsive to drugs and drug cues. Smokers often manage their craving and can remain abstinent for extended periods after quitting, however the risk of eventual relapse approaches 90%. Given that chronic medication may not be a practical solution to the long-term risk of relapse, acute baclofen may be useful on an ‘as-needed’ basis to block craving during ‘at risk’ situations. PMID:22513380

  8. d-Amino Acid Levels in Perfused Mouse Brain Tissue and Blood: A Comparative Study.

    PubMed

    Weatherly, Choyce A; Du, Siqi; Parpia, Curran; Santos, Polan T; Hartman, Adam L; Armstrong, Daniel W

    2017-02-16

    The l-enantiomer is the predominant type of amino acid in all living systems. However, d-amino acids, once thought to be "unnatural", have been found to be indigenous even in mammalian systems and increasingly appear to be functioning in essential biological and neurological roles. Both d- and l-amino acid levels in the hippocampus, cortex, and blood samples from NIH Swiss mice are reported. Perfused brain tissues were analyzed for the first time, thereby eliminating artifacts due to endogenous blood, and decreased the mouse-to-mouse variability in amino acid levels. Total amino acid levels (l- plus d-enantiomers) in brain tissue are up to 10 times higher than in blood. However, all measured d-amino acid levels in brain tissue are typically ∼10 to 2000 times higher than blood levels. There was a 13% reduction in almost all measured d-amino acid levels in the cortex compared to those in the hippocampus. There is an approximate inverse relationship between the prevalence of an amino acid and the percentage of its d-enantiomeric form. Interestingly, glutamic acid, unlike all other amino acids, had no quantifiable level of its d-antipode. The bioneurological reason for the unique and conspicuous absence/removal of this d-amino acid is yet unknown. However, results suggest that d-glutamate metabolism is likely a unidirectional process and not a cycle, as per the l-glutamate/glutamine cycle. The results suggest that there might be unreported d-amino acid racemases in mammalian brains. The regulation and function of specific other d-amino acids are discussed.

  9. Blood pressure reduction does not reduce perihematoma oxygenation: a CT perfusion study.

    PubMed

    Kate, Mahesh P; Hansen, Mikkel B; Mouridsen, Kim; Østergaard, Leif; Choi, Victor; Gould, Bronwen E; McCourt, Rebecca; Hill, Michael D; Demchuk, Andrew M; Coutts, Shelagh B; Dowlatshahi, Dariush; Emery, Derek J; Buck, Brian H; Butcher, Kenneth S

    2014-01-01

    Blood pressure (BP) reduction after intracerebral hemorrhage (ICH) is controversial, because of concerns that this may cause critical reductions in perihematoma perfusion and thereby precipitate tissue damage. We tested the hypothesis that BP reduction reduces perihematoma tissue oxygenation.Acute ICH patients were randomized to a systolic BP target of <150 or <180 mm Hg. Patients underwent CT perfusion (CTP) imaging 2 hours after randomization. Maps of cerebral blood flow (CBF), maximum oxygen extraction fraction (OEF(max)), and the resulting maximum cerebral metabolic rate of oxygen (CMRO2(max)) permitted by local hemodynamics, were calculated from raw CTP data.Sixty-five patients (median (interquartile range) age 70 (20)) were imaged at a median (interquartile range) time from onset to CTP of 9.8 (13.6) hours. Mean OEF(max) was elevated in the perihematoma region (0.44±0.12) relative to contralateral tissue (0.36±0.11; P<0.001). Perihematoma CMRO2(max) (3.40±1.67 mL/100 g per minute) was slightly lower relative to contralateral tissue (3.63±1.66 mL/100 g per minute; P=0.025). Despite a significant difference in systolic BP between the aggressive (140.5±18.7 mm Hg) and conservative (163.0±10.6 mm Hg; P<0.001) treatment groups, perihematoma CBF was unaffected (37.2±11.9 versus 35.8±9.6 mL/100 g per minute; P=0.307). Similarly, aggressive BP treatment did not affect perihematoma OEF(max) (0.43±0.12 versus 0.45±0.11; P=0.232) or CMRO2(max) (3.16±1.66 versus 3.68±1.85 mL/100 g per minute; P=0.857). Blood pressure reduction does not affect perihematoma oxygen delivery. These data support the safety of early aggressive BP treatment in ICH.

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

    PubMed

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

    2014-04-01

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

  11. Optical micro-angiography images structural and functional cerebral blood perfusion in mice with cranium left intact.

    PubMed

    Jia, Yali; Wang, Ruikang K

    2011-01-01

    Alteration in regional cerebral blood flow (CBF) is the direct result of changes in neuronal activity. It is crucial to monitor the spatio-temporal characteristics of cerebro-vascular blood perfusion in the studies of cerebral diseases. Optical micro-angiography (OMAG) is a recently developed imaging technique capable of resolving 3D distribution of dynamic blood perfusion at a capillary level resolution within microcirculatory beds in vivo. The authors report the applications of OMAG in mouse ischemic stroke model. The study demonstrates that OMAG is a useful method capable of providing in vivo serial assessment of 3D cerebro-vascular pathophysiology with high sensitivity, and therefore, has the potential for use in the study of brain disorders and repairs.

  12. Effect of 13-NLE-motilin on gastric secretion, serum gastrin level and mucosal blood flow in dogs.

    PubMed Central

    Konturek, S J; Dembinski, A; Krol, R; Wünsch, E

    1977-01-01

    1. In dogs with gastric fistulas and vagally innervated fundic and antral pouches, 13-norleucine-motilin (13-nle-motilin), a synthetic analogue of motilin, infused intravenously in graded doses produced a dose-dependent increase in gastric acid and pepsin outputs. 2. The motilin-induced stimulation of gastric secretion occurred independently of antral pH and was not accompanied by any alteration in the serum gastrin level suggesting that motilin did not affect the release of gastrin. 3. When infused intravenously in a constant dose against a constant background stimulation with pentagastrin or histamine 13-nle-motilin inhibited both acid and pepsin secretion from the main stomach and fundic pouch. 4. The inhibitory effect of 13-nle-motilin was always associated with a marked reduction in mucosal blood flow but without any change in the ratio of aminopyrine concentration in the gastric juice and blood plasma indicating that this peptide primarily affected gastric secretion but did not limit the gastric mucosal microcirculation. PMID:321755

  13. Comparison of microsphere-equivalent blood flow (15O-water PET) and relative perfusion (99mTc-tetrofosmin SPECT) in myocardium showing metabolism-perfusion mismatch.

    PubMed

    Schaefer, Wolfgang M; Nowak, Bernd; Kaiser, Hans-Juergen; Koch, Karl-Christian; Block, Stephan; vom Dahl, Juergen; Buell, Udalrich

    2003-01-01

    Myocardial perfusion imaging with (99m)Tc-tetrofosmin is based on the assumption of a linear correlation between myocardial blood flow (MBF) and tracer uptake. However, it is known that (99m)Tc-tetrofosmin uptake is directly related to energy-dependent transport processes, such as Na(+)/H(+) ion channel activity, as well as cellular and mitochondrial membrane potentials. Therefore, cellular alterations that affect these energy-dependent transport processes ought to influence (99m)Tc-tetrofosmin uptake independently of blood flow. Because metabolism ((18)F-FDG)-perfusion ((99m)Tc-tetrofosmin) mismatch myocardium (MPMM) reflects impaired but viable myocardium showing cellular alterations, MPMM was chosen to quantify the blood flow-independent effect of cellular alterations on (99m)Tc-tetrofosmin uptake. Therefore, we compared microsphere-equivalent MBF (MBF_micr; (15)O-water PET) and (99m)Tc-tetrofosmin uptake in MPMM and in "normal" myocardium. Forty-two patients with severe coronary artery disease, referred for myocardial viability diagnostics, were examined using (18)F-FDG PET and (99m)Tc-tetrofosmin perfusion SPECT. Relative (18)F-FDG and (99m)Tc-tetrofosmin uptake values were calculated using 18 segments per patient. Normal myocardium and MPMM myocardium were classified using a previously validated (99m)Tc-tetrofosmin SPECT/(18)F-FDG PET score. In addition, (15)O-water PET was performed to assess kinetic-modeled MBF (MBF_kin), the water-perfusable tissue fraction (PTF), and the resulting MBF_micr (MBF_kin x PTF), which is comparable to tracer uptake values. (99m)Tc-tetrofosmin uptake and MBF_micr values were calculated for all normal and MPMM segments and averaged within their respective classifications. Mean relative (99m)Tc-tetrofosmin uptake was 86% +/- 1% in normal myocardium and 56% +/- 1% in MPMM, showing a significant difference (P < 0.001), as was expected from the classification. Contrary to these findings, mean MBF_micr in MPMM myocardium was 0

  14. Reducing body fat with altitude hypoxia training in swimmers: role of blood perfusion to skeletal muscles.

    PubMed

    Chia, Michael; Liao, Chin-An; Huang, Chih-Yang; Lee, Wen-Chih; Hou, Chien-Wen; Yu, Szu-Hsien; Harris, M Brennan; Hsu, Tung-Shiung; Lee, Shin-Da; Kuo, Chia-Hua

    2013-02-28

    Swimmers tend to have greater body fat than athletes from other sports. The purpose of the study was to examine changes in body composition after altitude hypoxia exposure and the role of blood distribution to the skeletal muscle in swimmers. With a constant training volume of 12.3 km/day, young male swimmers (N = 10, 14.8 ± 0.5 years) moved from sea-level to a higher altitude of 2,300 meters. Body composition was measured before and after translocation to altitude using dual-energy X-ray absorptiometry (DXA) along with 8 control male subjects who resided at sea level for the same period of time. To determine the effects of hypoxia on muscle blood perfusion, total hemoglobin concentration (THC) was traced by near-infrared spectroscopy (NIRS) in the triceps and quadriceps muscles under glucose-ingested and insulin-secreted conditions during hypoxia exposure (16% O2) after training. While no change in body composition was found in the control group, subjects who trained at altitude had unequivocally decreased fat mass (-1.7 ± 0.3 kg, -11.4%) with increased lean mass (+0.8 ± 0.2 kg, +1.5%). Arterial oxygen saturation significantly decreased with increased plasma lactate during hypoxia recovery mimicking 2,300 meters at altitude (~93% versus ~97%). Intriguingly, hypoxia resulted in elevated muscle THC, and sympathetic nervous activities occurred in parallel with greater-percent oxygen saturation in both muscle groups. In conclusion, the present study provides evidence that increased blood distribution to the skeletal muscle under postprandial condition may contribute to the reciprocally increased muscle mass and decreased body mass after a 3-week altitude exposure in swimmers.

  15. Effects on resting cerebral blood flow and functional connectivity induced by metoclopramide: a perfusion MRI study in healthy volunteers.

    PubMed

    Fernández-Seara, María A; Aznárez-Sanado, Maite; Mengual, Elisa; Irigoyen, Jaione; Heukamp, Franz; Pastor, María A

    2011-08-01

    BACKGROUND AND PURPOSE The substituted benzamide, metoclopramide, is a dopamine receptor antagonist and is widely prescribed in the symptomatic treatment of nausea and vomiting, although it can cause adverse motor and non-motor side effects. The effects of metoclopramide on brain metabolism have not been investigated to date. EXPERIMENTAL APPROACH To determine the effects of metoclopramide on brain function, cerebral perfusion changes after a single oral dose were assessed in healthy volunteers using magnetic resonance imaging (MRI) techniques. Arterial spin labelling (ASL) perfusion MRI was used to measure cerebral blood flow before and after metoclopramide. Blood haemodynamics in the vertebral and internal carotid arteries were evaluated using phase-contrast MRI. KEY RESULTS Metoclopramide altered haemodynamics in the carotid arteries and the cerebral perfusion. Perfusion increased bilaterally in the putamen, consistent with antagonism of dopamine D(2) receptors by metoclopramide and possibly related to its motor side effects. In contrast, reduced perfusion was observed in the insular cortices and anterior temporal lobes. In addition, functional connectivity between the insular cortex and the dorsolateral prefrontal cortex was decreased. These cortical changes affecting neural circuits between high-order association areas may underlie certain neuropsychiatric conditions occasionally reported after metoclopramide administration. CONCLUSIONS AND IMPLICATIONS The present results show the sensitivity of ASL to detect small changes in regional blood flow, closely related to brain function, after a single pharmacological challenge, highlighting the potential of this technique for human pharmacological studies. © 2011 FUNDACIÓN PARA LA INVESTIGACIÓN MÉDICA APLICADA. British Journal of Pharmacology © 2011 The British Pharmacological Society.

  16. Effects on resting cerebral blood flow and functional connectivity induced by metoclopramide: a perfusion MRI study in healthy volunteers

    PubMed Central

    Fernández-Seara, María A; Aznárez-Sanado, Maite; Mengual, Elisa; Irigoyen, Jaione; Heukamp, Franz; Pastor, María A

    2011-01-01

    BACKGROUND AND PURPOSE The substituted benzamide, metoclopramide, is a dopamine receptor antagonist and is widely prescribed in the symptomatic treatment of nausea and vomiting, although it can cause adverse motor and non-motor side effects. The effects of metoclopramide on brain metabolism have not been investigated to date. EXPERIMENTAL APPROACH To determine the effects of metoclopramide on brain function, cerebral perfusion changes after a single oral dose were assessed in healthy volunteers using magnetic resonance imaging (MRI) techniques. Arterial spin labelling (ASL) perfusion MRI was used to measure cerebral blood flow before and after metoclopramide. Blood haemodynamics in the vertebral and internal carotid arteries were evaluated using phase-contrast MRI. KEY RESULTS Metoclopramide altered haemodynamics in the carotid arteries and the cerebral perfusion. Perfusion increased bilaterally in the putamen, consistent with antagonism of dopamine D2 receptors by metoclopramide and possibly related to its motor side effects. In contrast, reduced perfusion was observed in the insular cortices and anterior temporal lobes. In addition, functional connectivity between the insular cortex and the dorsolateral prefrontal cortex was decreased. These cortical changes affecting neural circuits between high-order association areas may underlie certain neuropsychiatric conditions occasionally reported after metoclopramide administration. CONCLUSIONS AND IMPLICATIONS The present results show the sensitivity of ASL to detect small changes in regional blood flow, closely related to brain function, after a single pharmacological challenge, highlighting the potential of this technique for human pharmacological studies. LINKED ARTICLES This article is part of a themed section on Imaging. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2011.163.issue-8BJP has previously published an Imaging in Pharmacology themed section, edited by A Davenport and C

  17. Luxury perfusion syndrome confirmed by sequential studies of regional cerebral blood flow and volume after extracranial to intracranial bypass surgery: case report.

    PubMed

    Higashi, S; Matsuda, H; Fujii, H; Ito, H; Yamashita, J

    1989-07-01

    We report a case of luxury perfusion syndrome with temporary neurological deterioration after extracranial to intracranial bypass surgery. A preoperative computed tomographic scan showed no detectable infarct, and the measurement of regional cerebral blood flow showed severe depression of ipsilateral hemispheric perfusion. The patient developed temporary neurological deterioration after bypass surgery, with no recognizable pathological signs on postoperative computed tomographic and angiographic studies. Regional cerebral blood flow and volume were more elevated during the period of neurological deterioration than after the subsequent recovery. This strongly suggests that excessive blood flow directed into chronically ischemic brain through a graft may induce a luxury perfusion syndrome resulting in neurological deterioration.

  18. Permeabilization of the blood-brain barrier via mucosal engrafting: implications for drug delivery to the brain.

    PubMed

    Bleier, Benjamin S; Kohman, Richie E; Feldman, Rachel E; Ramanlal, Shreshtha; Han, Xue

    2013-01-01

    Utilization of neuropharmaceuticals for central nervous system(CNS) disease is highly limited due to the blood-brain barrier(BBB) which restricts molecules larger than 500Da from reaching the CNS. The development of a reliable method to bypass the BBB would represent an enormous advance in neuropharmacology enabling the use of many potential disease modifying therapies. Previous attempts such as transcranial catheter implantation have proven to be temporary and associated with multiple complications. Here we describe a novel method of creating a semipermeable window in the BBB using purely autologous tissues to allow for high molecular weight(HMW) drug delivery to the CNS. This approach is inspired by recent advances in human endoscopic transnasal skull base surgical techniques and involves engrafting semipermeable nasal mucosa within a surgical defect in the BBB. The mucosal graft thereby creates a permanent transmucosal conduit for drugs to access the CNS. The main objective of this study was to develop a murine model of this technique and use it to evaluate transmucosal permeability for the purpose of direct drug delivery to the brain. Using this model we demonstrate that mucosal grafts allow for the transport of molecules up to 500 kDa directly to the brain in both a time and molecular weight dependent fashion. Markers up to 40 kDa were found within the striatum suggesting a potential role for this technique in the treatment of Parkinson's disease. This proof of principle study demonstrates that mucosal engrafting represents the first permanent and stable method of bypassing the BBB thereby providing a pathway for HMW therapeutics directly into the CNS.

  19. Relationships among ventilation-perfusion distribution, multiple inert gas methodology and metabolic blood-gas tensions.

    PubMed

    Lee, A S; Patterson, R W; Kaufman, R D

    1987-12-01

    The retention equations upon which the Multiple Inert Gas Method is based are derived from basic principles using elementary algebra. It is shown that widely disparate distributions produce indistinguishable sets of retentions. The limits of resolution of perfused compartments in the VA/Q distribution obtainable by the use of the multiple inert gas method are explored mathematically, and determined to be at most shunt and two alveolar compartments ("tripartite" distribution). Every continuous distribution studied produced retentions indistinguishable from those of its unique "matching" tripartite distribution. When a distribution is minimally specified, it is unique. Any additional specification (increased resolution--more compartments) of the distribution results in the existence of an infinitude of possible distributions characterized by indistinguishable sets of retention values. No further increase in resolution results from the use of more tracers. When sets of retention values were extracted from published multiple inert gas method continuous distributions, and compared with the published "measured" retention sets, substantial differences were found. This illustrates the potential errors incurred in the practical, in vivo application of the multiple inert gas method. In preliminary studies, the tripartite distribution could be determined with at least comparable accuracy by blood-gas (oxygen, carbon dioxide) measurements.

  20. Perfusion functional MRI reveals cerebral blood flow pattern under psychological stress

    NASA Astrophysics Data System (ADS)

    Wang, Jiongjiong; Rao, Hengyi; Wetmore, Gabriel S.; Furlan, Patricia M.; Korczykowski, Marc; Dinges, David F.; Detre, John A.

    2005-12-01

    Despite the prevalence of stress in everyday life and its impact on happiness, health, and cognition, little is known about the neural substrate of the experience of everyday stress in humans. We use a quantitative and noninvasive neuroimaging technique, arterial spin-labeling perfusion MRI, to measure cerebral blood flow (CBF) changes associated with mild to moderate stress induced by a mental arithmetic task with performance monitoring. Elicitation of stress was verified by self-report of stress and emotional state and measures of heart rate and salivary-cortisol level. The change in CBF induced by the stress task was positively correlated with subjective stress rating in the ventral right prefrontal cortex (RPFC) and left insula/putamen area. The ventral RPFC along with right insula/putamen and anterior cingulate showed sustained activation after task completion in subjects reporting a high stress level during arithmetic tasks. Additionally, variations of baseline CBF in the ventral RPFC and right orbitofrontal cortex were found to correlate with changes in salivary-cortisol level and heart rate caused by undergoing stress tasks. We further demonstrated that the observed right prefrontal activation could not be attributed to increased cognitive demand accompanying stress tasks and extended beyond neural pathways associated with negative emotions. Our results provide neuroimaging evidence that psychological stress induces negative emotion and vigilance and that the ventral RPFC plays a key role in the central stress response. anterior cingulate cortex | arterial spin labeling | right prefrontal cortex

  1. The relationship between digital perfusion pressure and hoof lamellar blood flow in isoflurane-anesthetized horses.

    PubMed

    Brosnan, Robert J; Steffey, Eugene P; Esteller-Vico, Alejandro; Vaughan, Betsy; Liu, Irwin K

    2011-02-01

    Digital perfusion pressure (DPP) equals mean arterial pressure (MAP) at the hoof coronet minus digital interstitial pressure (DIP) within the hoof. To test whether lamellar blood flow (LBF) changes proportionately to DPP, anesthesia was induced and maintained with isoflurane in six horses to target a MAP of 60 mmHg. Arterial, venous, and hoof interstitial pressures were measured in each pelvic limb. LBF was measured using fluorescent microspheres during dobutamine infusions targeting either 60 (low), 80 (medium), or 100 (high) mmHg MAP. Following euthanasia, hoof lamina was collected for microsphere isolation. To reduce intra-individual variability, medium and high pressures and flows were divided by their respective low pressure and flow baseline values, yielding indexed variables of ΔLBF and ΔDPP. The ΔLBF correlated negatively with the ΔDPP. We conclude that LBF was not solely determined by passive pressure-flow relationships and that systemic hypertension may not effectively increase dermal LBF in horses. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. Thermal behavior of human eye in relation with change in blood perfusion, porosity, evaporation and ambient temperature.

    PubMed

    Rafiq, Aasma; Khanday, M A

    2016-12-01

    Extreme environmental and physiological conditions present challenges for thermal processes in body tissues including multi-layered human eye. A mathematical model has been formulated in this direction to study the thermal behavior of the human eye in relation with the change in blood perfusion, porosity, evaporation and environmental temperatures. In this study, a comprehensive thermal analysis has been performed on the multi-layered eye using Pennes' bio-heat equation with appropriate boundary and interface conditions. The variational finite element method and MATLAB software were used for the solution purpose and simulation of the results. The thermoregulatory effect due to blood perfusion rate, porosity, ambient temperature and evaporation at various regions of human eye was illustrated mathematically and graphically. The main applications of this model are associated with the medical sciences while performing laser therapy and other thermoregulatory investigation on human eye.

  3. Epoxyeicosatrienoic acids mediate insulin-mediated augmentation in skeletal muscle perfusion and blood volume

    PubMed Central

    Shim, Chi Young; Kim, Sajeevani; Chadderdon, Scott; Wu, Melinda; Qi, Yue; Xie, Aris; Alkayed, Nabil J.; Davidson, Brian P.

    2014-01-01

    Skeletal muscle microvascular blood flow (MBF) increases in response to physiological hyperinsulinemia. This vascular action of insulin may facilitate glucose uptake. We hypothesized that epoxyeicosatrienoic acids (EETs), a family of arachadonic, acid-derived, endothelium-derived hyperpolarizing factors, are mediators of insulin's microvascular effects. Contrast-enhanced ultrasound (CEU) was performed to quantify skeletal muscle capillary blood volume (CBV) and MBF in wild-type and obese insulin-resistant (db/db) mice after administration of vehicle or trans-4-[4-(3-adamantan-1-ylureido)cyclohexyloxy]benzoic acid (t-AUCB), an inhibitor of soluble epoxide hydrolase that converts EETs to less active dihydroxyeicosatrienoic acids. Similar studies were performed in rats pretreated with l-NAME. CEU was also performed in rats undergoing a euglycemic hyperinsulinemic clamp, half of which were pretreated with the epoxygenase inhibitor MS-PPOH to inhibit EET synthesis. In both wild-type and db/db mice, intravenous t-AUCB produced an increase in CBV (65–100% increase at 30 min, P < 0.05) and in MBF. In db/db mice, t-AUCB also reduced plasma glucose by ∼15%. In rats pretreated with l-NAME, t-AUCB after produced a significant ≈20% increase in CBV, indicating a component of vascular response independent of nitric oxide (NO) production. Hyperinsulinemic clamp produced a time-dependent increase in MBF (19 ± 36 and 76 ± 49% at 90 min, P = 0.026) that was mediated in part by an increase in CBV. Insulin-mediated changes in both CBV and MBF during the clamp were blocked entirely by MS-PPOH. We conclude that EETs are a mediator of insulin-mediated augmentation in skeletal muscle perfusion and are involved in regulating changes in CBV during hyperinsulinemia. PMID:25336524

  4. Oxygen saturation, red blood cell tissue fraction and speed resolved perfusion - A new optical method for microcirculatory assessment.

    PubMed

    Jonasson, Hanna; Fredriksson, Ingemar; Pettersson, Anders; Larsson, Marcus; Strömberg, Tomas

    2015-11-01

    We have developed a new fiber-optic system that combines diffuse reflectance spectroscopy (DRS) and laser Doppler Flowmetry (LDF) for a multi-modal assessment of the microcirculation. Quantitative data is achieved with an inverse Monte Carlo algorithm based on an individually adaptive skin model. The output parameters are calculated from the model and given in absolute units: hemoglobin oxygen saturation (%), red blood cell (RBC) tissue fraction (%), and the speed resolved RBC perfusion separated into three speed regions; 0-1mm/s, 1-10mm/s and above 10mm/s (% mm/s). The aim was to explore microcirculatory parameters using the new optical method, integrating DRS and LDF in a joint skin model, during local heating of the dorsal foot and venous and arterial occlusion of the forearm in 23 healthy subjects (age 20-28years). There were differences in the three speed regions in regard to blood flow changes due to local heating, where perfusion for high speeds increased the most. There was also a high correlation between changes in oxygenation and changes in perfusion for higher speeds. Oxygen saturation at baseline was 44% on foot, increasing to 83% at plateau after heating. The larger increase in perfusion for higher speeds than for lower speeds together with the oxygenation increase during thermal provocation, shows a local thermoregulatory blood flow in presumably arteriolar dermal vessels. In conclusion, there are improved possibilities to assess microcirculation using integrated DRS and LDF in a joint skin model by enabling both oxygenation and speed resolved blood flow assessment simultaneously and in the same skin site. Output parameters in absolute units may also yield new insights about the microcirculatory system. Copyright © 2015. Published by Elsevier Inc.

  5. Recovery of mucosal-associated invariant T cells after myeloablative chemotherapy and autologous peripheral blood stem cell transplantation.

    PubMed

    Novak, Jan; Dobrovolny, Jan; Brozova, Jitka; Novakova, Lucie; Kozak, Tomas

    2016-11-01

    Immune reconstitution after high-dose chemotherapy and stem cell transplantation plays a key role in restoring immunocompetence including defense against infection, immune regulation, and onco-immune surveillance. In this work, we examined the recovery of mucosal-associated invariant T (MAIT) cells, recently discovered innate-like T cells, after various types of myeloablative chemotherapy and autologous peripheral blood stem cell transplantation in 29 patients. We show that MAIT cells are relatively resistant to myeloablative conditioning. The median amount of MAIT cells rises to 43 % around day +30 and is sustained through further measurements on days +60 and +100. Moreover, MAIT cell recovery reaches 100 % of pre-treatment values in 33 % of patients already by day +60. The only factor affecting recovery of MAIT cells is age, younger age being associated with earlier MAIT cell recovery. The pre-treatment quantity of MAIT cells carries a prognostic impact on the early post-transplantation course. Patients with high levels of MAIT cells pre-treatment have significantly lower peak CRP levels (79.45 vs. 150 mg/L) post-treatment, reflecting a clinical trend of less severe infectious complications (less febrile days and less days on intravenous antibiotics). Altogether these data suggest that a high proportion of MAIT cells survive myeloablative chemotherapy and maintain their capacity to fight against infections probably on mucosal surfaces.

  6. Transient finite element analysis of thermal methods used to estimate SAR and blood flow in homogeneously and nonhomogeneously perfused tumour models.

    PubMed

    Wong, T Z; Mechling, J A; Jones, E L; Strohbehn, J W

    1988-01-01

    A two-dimensional time-dependent finite element model was developed to evaluate thermal techniques for estimating blood flow and specific absorption rate (SAR). In these computer simulations, homogeneously and nonhomogeneously perfused tumour models were heated by a 915 MHz interstitial microwave antenna array. Representative blood flow values were assigned within the tumour, and the applied SAR distribution was based on a previously developed antenna theory. SAR values were estimated from the power-on transient temperatures, and blood flow values were estimated from thermal clearance data after power was discontinued. These estimated parameters were then compared to the known 'true' blood flow and SAR values throughout the treatment region. SAR values could be predicted with reasonable accuracy throughout most of the heated region independent of local blood flow. For a homogeneous model, thermal clearance was found to yield reasonably accurate blood flow estimates at high perfusion rates and less accurate estimates at lower perfusion rates. However, for the inhomogeneous model, the blood perfusion estimates were generally poor, and an average blood flow value for the tumour was obtained with little ability to resolve the differences in perfusion between regions. Using temperatures observed early in the cool-down curve resulted in improved spatial resolution, but increased the contribution of thermal conduction to the blood flow estimates. A single time-constant exponential thermal decay curve was found to be a necessary but not sufficient condition for reliable blood flow estimates using this technique.

  7. Mapping of cerebro-vascular blood perfusion in mice with skin and skull intact by Optical Micro-AngioGraphy at 1.3 mum wavelength.

    PubMed

    Wang, Ruikang K; Hurst, Sawan

    2007-09-03

    Optical micro-angiography (OMAG) was developed to achieve volumetric imaging of the microstructures and dynamic cerebrovascular blood perfusion in mice with capillary level resolution and high signal-to-background ratio. In this paper, we present a high-speed and high-sensitivity OMAG imaging system by using an InGaAs line scan camera and broadband light source at 1.3 mum wavelength for enhanced imaging depth in tissue. We show that high quality imaging of cerebrovascular blood perfusion down to capillary level resolution with the intact skin and cranium are obtained in vivo with OMAG, without the interference from the blood perfusion in the overlaying skin. The results demonstrate the potential of 1.3 mum OMAG for high-speed and high-sensitivity imaging of blood perfusion in human and small animal studies.

  8. Myocardial perfusion quantification using the T1 -based FAIR-ASL method: the influence of heart anatomy, cardiopulmonary blood flow and look-locker readout.

    PubMed

    Kampf, Thomas; Helluy, Xavier; Gutjahr, Fabian T; Winter, Patrick; Meyer, Cord B; Jakob, Peter M; Bauer, Wolfgang R; Ziener, Christian H

    2014-05-01

    The quantification of myocardial perfusion using a Look-Locker flow-sensitive alternating inversion recovery- arterial spin labeling experiment is considered. Due to the anatomy of the heart, a substantial but unintended partial inversion of the inflowing blood occurs during the slice-selective inversion. Both, the partial inversion as well as the Look-Locker pulse train, influence the myocardial perfusion quantification and are addressed in this work. The mean relaxation time approximation is used to calculate the monoexponential relaxation time of the signal in perfused tissue under Look-Locker readout. The left ventricular blood serves as an approximation of the inflowing blood in the description of FAIR-ASL measurements with global and slice-selective inversion to correctly quantify the myocardial perfusion. The analysis shows that the myocardial perfusion can be overestimated if the T1 -based quantification method is not adapted respecting the Look-Locker pulse train explicitly. Additionally, it turns out that without correction for the partial inversion of the blood pool during the slice-selective inversion the myocardial perfusion is underestimated. It is shown that the Look-Locker readout as well as the nonideal slice-selective inversion experiment have a considerable influence and have to be included properly to correctly quantify myocardial perfusion. Copyright © 2013 Wiley Periodicals, Inc.

  9. The lognormal perfusion model for disruption replenishment measurements of blood flow: in vivo validation.

    PubMed

    Hudson, John M; Leung, Kogee; Burns, Peter N

    2011-10-01

    Dynamic contrast enhanced ultrasound (DCE-US) is evolving as a promising tool to noninvasively quantify relative tissue perfusion in organs and solid tumours. Quantification using the method of disruption replenishment is best performed using a model that accurately describes the replenishment of microbubble contrast agents through the ultrasound imaging plane. In this study, the lognormal perfusion model was validated using an exposed in vivo rabbit kidney model. Compared against an implanted transit time flow meter, longitudinal relative flow measurement was (×3) less variable and correlated better when quantification was performed with the lognormal perfusion model (Spearman r = 0.90, 95% confidence interval [CI] = 0.05) vs. the prevailing mono-exponential model (Spearman r = 0.54, 95% CI = 0.18). Disruption-replenishment measurements using the lognormal perfusion model were reproducible in vivo to within 12%.

  10. Correlations between skin blood perfusion values and nailfold capillaroscopy scores in systemic sclerosis patients.

    PubMed

    Ruaro, B; Sulli, A; Pizzorni, C; Paolino, S; Smith, V; Cutolo, M

    2016-05-01

    To correlate blood perfusion (BP) values assessed by laser speckle contrast analysis (LASCA) in selected skin areas of hands and face with nailfold capillary damage scores in systemic sclerosis (SSc) patients. Seventy SSc patients (mean SSc duration 6 ± 5 years) and 70 volunteer healthy subjects were enrolled after informed consent. LASCA was performed at different areas of the face (forehead, tip of nose, zygomas and perioral region) and at dorsal and volar regions of hands. Microvascular damage was assessed and scored by nailfold videocapillaroscopy (NVC) and the microangiopathy evolution score (MES) was calculated. SSc patients showed a significantly lower BP than healthy subjects at fingertips, periungual areas and palm of hands (p<0.0001), but not at the level of face and dorsum of hands. A gradual decrease of BP at fingertips, periungual and palm areas, was found in SSc patients with progressive severity of NVC patterns of microangiopathy ("early", "active", or "late") (p<0.01). A negative correlation was observed between MES and BP values, as well as between loss of capillaries and BP, at the same areas (p<0.001 and p<0.01, respectively). Patients with diffuse cutaneous SSc (dcSSc) showed lower BP than those with limited cutaneous SSc (p<0.04). LASCA detects a significant reduction of BP only in those areas usually affected by Raynaud's phenomenon (fingertips, periungual and palm areas), especially in dcSSc patients, and BP values significantly correlate with the nailfold capillaroscopy scores of microangiopathy. Copyright © 2016. Published by Elsevier Inc.

  11. Three distinct phases of VF during global ischemia in the isolated blood-perfused pig heart.

    PubMed

    Huizar, Jose F; Warren, Mark D; Shvedko, Alexander G; Kalifa, Jérôme; Moreno, Javier; Mironov, Sergey; Jalife, José; Zaitsev, Alexey V

    2007-09-01

    Changes in ventricular fibrillation (VF) organization occurring after the onset of global ischemia are relevant to defibrillation and survival but remain poorly understood. We hypothesized that ischemia-specific dynamic instability of the action potential (AP) causes a loss of spatiotemporal periodicity of propagation and broadening of the electrocardiogram (ECG) frequency spectrum during VF in the ischemic myocardium. We recorded voltage-sensitive fluorescence of di-4-ANEPPS (anterior left ventricle, 35 x 35 mm, 64 x 64 pixels) and the volume-conducted ECG in six blood-perfused hearts during 10 min of VF and global ischemia. We used coefficient of variation (CV) to estimate variability of AP amplitude, AP duration, and diastolic interval (CV-APA, CV-APD, and CV-DI, respectively). We computed excitation median frequency (Median_F), spectral width of the AP and ECG (SpW-AP and SpW-ECG, respectively), wavebreak incidence (WBI), and recurrence of propagation direction (RPD). We found three distinct phases of local VF dynamics: "relatively periodic" (

  12. Oral mucosal blood flow, plasma epinephrine and haemodynamic responses after injection of lidocaine with epinephrine during midazolam sedation and isoflurane anaesthesia.

    PubMed

    Homma, Y; Ichinohe, T; Kaneko, Y

    1999-04-01

    We have investigated the relationship between oral mucosal blood flow and plasma epinephrine concentration, and the effects of conscious sedation vs general anaesthesia on haemodynamic responses after submucosal epinephrine injection in 14 subjects. The same seven patients were studied both as controls and after sedation. For sedation, midazolam i.v. was used. Another seven patients underwent orthognathic surgery with isoflurane anaesthesia. All subjects received a submucosal injection of epinephrine 0.8 microgram kg-1, given as 2% lidocaine hydrochloride with epinephrine 12.5 micrograms ml-1. Baseline mucosal blood flow and peak increase in plasma epinephrine concentration in the general anaesthesia and sedation groups were approximately 2.0 and 1.5 times, respectively, higher than those in the control group. Mean plasma epinephrine concentration reached a maximum 3 min after administration of epinephrine in all groups. Overall, there was a significant correlation (r = 0.65) between baseline mucosal blood flow and the maximum increase in plasma epinephrine concentration. There were no differences in haemodynamic changes except for heart rate, between the three groups. These results suggest that plasma epinephrine concentration after submucosal injection depends on the initial mucosal blood flow in the injected area. Haemodynamic changes, except heart rate, in the sedation and general anaesthesia groups were similar despite different changes in maximum plasma epinephrine concentration.

  13. Blood perfusion values of laser speckle contrast imaging and laser Doppler flowmetry: is a direct comparison possible?

    PubMed

    Binzoni, Tiziano; Humeau-Heurtier, Anne; Abraham, Pierre; Mahe, Guillaume

    2013-05-01

    Laser Doppler flowmetry (LDF) and laser speckle contrast imaging (LSCI) allow the monitoring of microvascular blood perfusion. The relationship between the measurements obtained by these two techniques remains unclear. In the present contribution, we demonstrate, experimentally and theoretically, that skin blood flow measurements obtained by LDF and LSCI techniques cannot be compared directly even after "classical" normalization procedure. This technical problem is generated by the nonlinear relationship existing between LDF and LSCI flow data. The experiments have been performed on five healthy voluntary subjects (forearm) by using repeated ischemia/reperfusion cycles to induce the necessary skin blood flow changes. LDF and LSCI data were simultaneously acquired on the same region of interest. Considering the importance of this problem from the clinical point of view, it is concluded that the definition of new corrected algorithms for LSCI is probably a mandatory step that must be taken into account if LDF and LSCI blood flow have to be compared.

  14. TIPS bilateral noise reduction in 4D CT perfusion scans produces high-quality cerebral blood flow maps

    NASA Astrophysics Data System (ADS)

    Mendrik, Adriënne M.; Vonken, Evert-jan; van Ginneken, Bram; de Jong, Hugo W.; Riordan, Alan; van Seeters, Tom; Smit, Ewoud J.; Viergever, Max A.; Prokop, Mathias

    2011-07-01

    Cerebral computed tomography perfusion (CTP) scans are acquired to detect areas of abnormal perfusion in patients with cerebrovascular diseases. These 4D CTP scans consist of multiple sequential 3D CT scans over time. Therefore, to reduce radiation exposure to the patient, the amount of x-ray radiation that can be used per sequential scan is limited, which results in a high level of noise. To detect areas of abnormal perfusion, perfusion parameters are derived from the CTP data, such as the cerebral blood flow (CBF). Algorithms to determine perfusion parameters, especially singular value decomposition, are very sensitive to noise. Therefore, noise reduction is an important preprocessing step for CTP analysis. In this paper, we propose a time-intensity profile similarity (TIPS) bilateral filter to reduce noise in 4D CTP scans, while preserving the time-intensity profiles (fourth dimension) that are essential for determining the perfusion parameters. The proposed TIPS bilateral filter is compared to standard Gaussian filtering, and 4D and 3D (applied separately to each sequential scan) bilateral filtering on both phantom and patient data. Results on the phantom data show that the TIPS bilateral filter is best able to approach the ground truth (noise-free phantom), compared to the other filtering methods (lowest root mean square error). An observer study is performed using CBF maps derived from fifteen CTP scans of acute stroke patients filtered with standard Gaussian, 3D, 4D and TIPS bilateral filtering. These CBF maps were blindly presented to two observers that indicated which map they preferred for (1) gray/white matter differentiation, (2) detectability of infarcted area and (3) overall image quality. Based on these results, the TIPS bilateral filter ranked best and its CBF maps were scored to have the best overall image quality in 100% of the cases by both observers. Furthermore, quantitative CBF and cerebral blood volume values in both the phantom and the

  15. TIPS bilateral noise reduction in 4D CT perfusion scans produces high-quality cerebral blood flow maps.

    PubMed

    Mendrik, Adriënne M; Vonken, Evert-jan; van Ginneken, Bram; de Jong, Hugo W; Riordan, Alan; van Seeters, Tom; Smit, Ewoud J; Viergever, Max A; Prokop, Mathias

    2011-07-07

    Cerebral computed tomography perfusion (CTP) scans are acquired to detect areas of abnormal perfusion in patients with cerebrovascular diseases. These 4D CTP scans consist of multiple sequential 3D CT scans over time. Therefore, to reduce radiation exposure to the patient, the amount of x-ray radiation that can be used per sequential scan is limited, which results in a high level of noise. To detect areas of abnormal perfusion, perfusion parameters are derived from the CTP data, such as the cerebral blood flow (CBF). Algorithms to determine perfusion parameters, especially singular value decomposition, are very sensitive to noise. Therefore, noise reduction is an important preprocessing step for CTP analysis. In this paper, we propose a time-intensity profile similarity (TIPS) bilateral filter to reduce noise in 4D CTP scans, while preserving the time-intensity profiles (fourth dimension) that are essential for determining the perfusion parameters. The proposed TIPS bilateral filter is compared to standard Gaussian filtering, and 4D and 3D (applied separately to each sequential scan) bilateral filtering on both phantom and patient data. Results on the phantom data show that the TIPS bilateral filter is best able to approach the ground truth (noise-free phantom), compared to the other filtering methods (lowest root mean square error). An observer study is performed using CBF maps derived from fifteen CTP scans of acute stroke patients filtered with standard Gaussian, 3D, 4D and TIPS bilateral filtering. These CBF maps were blindly presented to two observers that indicated which map they preferred for (1) gray/white matter differentiation, (2) detectability of infarcted area and (3) overall image quality. Based on these results, the TIPS bilateral filter ranked best and its CBF maps were scored to have the best overall image quality in 100% of the cases by both observers. Furthermore, quantitative CBF and cerebral blood volume values in both the phantom and the

  16. Distinct aging profiles of CD8+ T cells in blood versus gastrointestinal mucosal compartments

    PubMed Central

    Ramirez, Christina M.; Hultin, Lance; Hausner, Mary Ann; Hultin, Patricia; Elliott, Julie; Yang, Otto O.; Anton, Peter A.; Jamieson, Beth D.; Effros, Rita B.

    2017-01-01

    A hallmark of human immunosenescence is the accumulation of late-differentiated memory CD8+ T cells with features of replicative senescence, such as inability to proliferate, absence of CD28 expression, shortened telomeres, loss of telomerase activity, enhanced activation, and increased secretion of inflammatory cytokines. Importantly, oligoclonal expansions of these cells are associated with increased morbidity and mortality risk in elderly humans. Currently, most information on the adaptive immune system is derived from studies using peripheral blood, which contains approximately only 2% of total body lymphocytes. However, most lymphocytes reside in tissues. It is not clear how representative blood changes are of the total immune status. This is especially relevant with regard to the human gastrointestinal tract (GALT), a major reservoir of total body lymphocytes (approximately 60%) and an anatomical region of high antigenic exposure. To assess how peripheral blood T cells relate to those in other locations, we compare CD8+ T cells from peripheral blood and the GALT, specifically rectosigmoid colon, in young/middle age, healthy donors, focusing on phenotypic and functional alterations previously linked to senescence in peripheral blood. Overall, our results indicate that gut CD8+ T cells show profiles suggestive of greater differentiation and activation than those in peripheral blood. Specifically, compared to blood from the same individual, the gut contains significantly greater proportions of CD8+ T cells that are CD45RA- (memory), CD28-, CD45RA-CD28+ (early memory), CD45RA-CD28- (late memory), CD25-, HLA-DR+CD38+ (activated) and Ki-67+ (proliferating); ex vivo CD3+ telomerase activity levels are greater in the gut as well. However, gut CD8+ T cells may not necessarily be more senescent, since they expressed significantly lower levels of CD57 and PD-1 on CD45RO+ memory cells, and had in vitro proliferative dynamics similar to that of blood cells. Compartment

  17. Distinct aging profiles of CD8+ T cells in blood versus gastrointestinal mucosal compartments.

    PubMed

    Dock, Jeffrey; Ramirez, Christina M; Hultin, Lance; Hausner, Mary Ann; Hultin, Patricia; Elliott, Julie; Yang, Otto O; Anton, Peter A; Jamieson, Beth D; Effros, Rita B

    2017-01-01

    A hallmark of human immunosenescence is the accumulation of late-differentiated memory CD8+ T cells with features of replicative senescence, such as inability to proliferate, absence of CD28 expression, shortened telomeres, loss of telomerase activity, enhanced activation, and increased secretion of inflammatory cytokines. Importantly, oligoclonal expansions of these cells are associated with increased morbidity and mortality risk in elderly humans. Currently, most information on the adaptive immune system is derived from studies using peripheral blood, which contains approximately only 2% of total body lymphocytes. However, most lymphocytes reside in tissues. It is not clear how representative blood changes are of the total immune status. This is especially relevant with regard to the human gastrointestinal tract (GALT), a major reservoir of total body lymphocytes (approximately 60%) and an anatomical region of high antigenic exposure. To assess how peripheral blood T cells relate to those in other locations, we compare CD8+ T cells from peripheral blood and the GALT, specifically rectosigmoid colon, in young/middle age, healthy donors, focusing on phenotypic and functional alterations previously linked to senescence in peripheral blood. Overall, our results indicate that gut CD8+ T cells show profiles suggestive of greater differentiation and activation than those in peripheral blood. Specifically, compared to blood from the same individual, the gut contains significantly greater proportions of CD8+ T cells that are CD45RA- (memory), CD28-, CD45RA-CD28+ (early memory), CD45RA-CD28- (late memory), CD25-, HLA-DR+CD38+ (activated) and Ki-67+ (proliferating); ex vivo CD3+ telomerase activity levels are greater in the gut as well. However, gut CD8+ T cells may not necessarily be more senescent, since they expressed significantly lower levels of CD57 and PD-1 on CD45RO+ memory cells, and had in vitro proliferative dynamics similar to that of blood cells. Compartment

  18. Dynamic subcortical blood flow during male sexual activity with ecological validity: a perfusion fMRI study.

    PubMed

    Georgiadis, Janniko R; Farrell, Michael J; Boessen, Ruud; Denton, Derek A; Gavrilescu, Maria; Kortekaas, Rudie; Renken, Remco J; Hoogduin, Johannes M; Egan, Gary F

    2010-03-01

    This study used arterial spin labeling (ASL) fMRI to measure brain perfusion in a group of healthy men under conditions that closely resembled customary sexual behavior. Serial perfusion measures for 30 min during two self-limited periods of partnered penis stimulation, and during post-stimulatory periods, revealed novel sexual activity-related cerebral blood flow (rCBF) changes, mainly in subcortical parts of the brain. Ventral pallidum rCBF was highest during the onset of penile erection, and lowest after the termination of penis stimulation. The perceived level of sexual arousal showed the strongest positive association with rCBF in the right basal forebrain. In addition, our results demonstrate that distinct subregions of the hypothalamus and cingulate cortex subserve opposite functions during human male sexual behavior. The lateral hypothalamus and anterior part of the middle cingulate cortex showed increased rCBF correlated with penile erection. By contrast, the anteroventral hypothalamus and subgenual anterior cingulate cortex exhibited rCBF changes correlated with penile detumescence after penile stimulation. Continuous rapid and high-resolution brain perfusion imaging during normal sexual activity has provided novel insights into the central mechanisms that control male sexual arousal. Copyright (c) 2009 Elsevier Inc. All rights reserved.

  19. Preserving low perfusion during surgical liver blood inflow control prevents hepatic microcirculatory dysfunction and irreversible hepatocyte injury in rats.

    PubMed

    Li, Chong-Hui; Chen, Yong-Wei; Chen, Yong-Liang; Yao, Li-Bin; Ge, Xin-Lan; Pan, Ke; Zhang, Ai-Qun; Dong, Jia-Hong

    2015-09-24

    Hepatic ischaemia/reperfusion (I/R) injury is of primary concern during liver surgery. We propose a new approach for preserving low liver blood perfusion during hepatectomy either by occlusion of the portal vein (OPV) while preserving hepatic artery flow or occlusion of the hepatic artery while limiting portal vein (LPV) flow to reduce I/R injury. The effects of this approach on liver I/R injury were investigated. Rats were randomly assigned into 4 groups: sham operation, occlusion of the portal triad (OPT), OPV and LPV. The 7-day survival rate was significantly improved in the OPV and LPV groups compared with the OPT group. Microcirculatory liver blood flow recovered rapidly after reperfusion in the OPV and LPV groups but decreased further in the OPT group. The OPV and LPV groups also showed much lower ALT and AST levels, Suzuki scores, inflammatory gene expression levels, and parenchymal necrosis compared with the OPT group. An imbalance between the expression of vasoconstriction and vasodilation genes was observed in the OPT group but not in the OPV or LPV group. Therefore, preserving low liver blood perfusion by either the OPV or LPV methods during liver surgery is very effective for preventing hepatic microcirculatory dysfunction and hepatocyte injury.

  20. Three-dimensional MR pulmonary perfusion imaging and angiography with an injection of a new blood pool contrast agent B-22956/1.

    PubMed

    Zheng, J; Carr, J; Harris, K; Saker, M B; Cavagna, F M; Maggioni, F; Laub, G; Li, D; Finn, J P

    2001-10-01

    Initial evaluation of a new blood pool agent, B-22956/1, for pulmonary imaging was performed in five domestic pigs with artificial embolism. Pre-embolism 3D pulmonary perfusion images were first acquired by injecting an extravascular agent, gadoteridol. The pulmonary arteries of the pigs were then occluded by the artificial emboli. Post-embolism perfusion scans were subsequently performed by injecting B-22956/1. Additional post-embolism high-spatial-resolution angiograms were also acquired. Parenchyma perfusion deficits were well depicted in the post-embolism perfusion maps. The post-embolism angiography clearly revealed the location and extent of the filling defects in the pulmonary vessels. Signal intensities of perfusion maps on the normal parenchyma were significantly improved (30%) by using B-22956/1, in comparison with perfusion images using gadoteridol (P < 0.01). Many pulmonary angiograms with approximately equal contrast could be obtained even at 22 minutes after the injection of B-22956/1. Our initial results indicate that blood pool agent B-22956/1 may provide opportunities for whole-lung-coverage perfusion mapping and additional high-resolution target angiograms after a single injection.

  1. Quantification of lung perfusion blood volume (lung PBV) by dual-energy CT in pulmonary embolism before and after treatment: preliminary results.

    PubMed

    Nagayama, Hiroki; Sueyoshi, Eijun; Hayashida, Takeshi; Ashizawa, Kazuto; Sakamoto, Ichiro; Uetani, Masataka

    2013-01-01

    The purpose was to investigate the quantification of lung perfusion blood volume (PBV) by dual-energy computed tomography (CT) in patients with pulmonary embolism (PE) before and after treatment. Twenty-five patients with PE underwent dual-energy CT angiography before and after treatment. In all 25 patients, pulmonary CT confirmed that there was no PE after treatment. This preliminary study demonstrated the possibility that quantification of lung PBV may reflect parenchymal arterial perfusion before and after treatment, including the compensatory increase of lung perfusion.

  2. Use of laser speckle contrast imaging to reveal changes in temperature and blood perfusion in the skin of healthy subjects after administration of heated moxa sticks and daiwenjiu ointment.

    PubMed

    Xu, Qingyan; Yang, Jinsheng; Wang, Liang; Deng, Zi; Wang, Yingying; Yang, Li; Wu, Peng; Li, Liang

    2014-08-01

    To investigate the influence of heated moxa sticks ("moxibustion") and Daiwenjiu ointment (DO) on changes in temperature and blood perfusion volume on the skin of the backs of healthy subjects. DO was spread on the left side of the body, and the right side of the body was treated with a heated moxa stick. Images denoting blood perfusion and body temperature were collected 7-8 cm lateral to the spinous process of the sixth thoracic vertebra using laser speckle contrast imaging (LSCI). Data obtained from eight-frame images were analyzed and used to calculate the mean blood perfusion volume. Simultaneously, blood-perfusion images were collected from the body surface and used to compare the change in blood flow on the body surface and the actual position of imaging. After moxibustion, a rapid increase in blood perfusion volume and body temperature was noted in the local skin surface. The maximum blood perfusion volume and body temperature was noted at 20 min (P < 0.05). At 80-110 min after the spreading of DO, a gradual increase was noted in blood perfusion volume (P < 0.05) and body temperature (P < 0.05) compared with the baseline level. The maximum blood perfusion volume was at 110 min. Using LSCI, these data revealed a rapid and sharp increase in blood perfusion volume and body temperature after treatment with moxibustion, but the respective changes seen in the DO group were gradual and moderate.

  3. Perfusion vs. oxygen delivery in transfusion with “fresh” and “old” red blood cells: The experimental evidence

    PubMed Central

    Tsai, Amy G.; Hofmann, Axel; Cabrales, Pedro; Intaglietta, Marcos

    2010-01-01

    We review the experimental evidence showing systemic and microvascular effects of blood transfusions instituted to support the organism in extreme hemodilution and hemorrhagic shock, focusing on the use of fresh vs. stored blood as a variable. The question: “What does a blood transfusion remedy?” was analyzed in experimental models addressing systemic and microvascular effects showing that oxygen delivery is not the only function that must be addressed. In extreme hemodilution and hemorrhagic shock blood transfusions simultaneously restore blood viscosity and oxygen carrying capacity, the former being critically needed for reestablishing a functional mechanical environment of the microcirculation, necessary for obtaining adequate capillary blood perfusion. Increased oxygen affinity due to 2,3 DPG depletion is shown to have either no effect or a positive oxygenation effect, when the transfused red blood cells (RBCs) do not cause additional flow impairment due to structural malfunctions including increased rigidity and release of hemoglobin. It is concluded that fresh RBCs are shown to be superior to stored RBCs in transfusion, however increased oxygen affinity may be a positive factor in hemorrhagic shock resuscitation. Although experimental studies seldom reproduce emergency and clinical conditions, nonetheless they serve to explore fundamental physiological mechanisms in the microcirculation that cannot be directly studied in humans. PMID:20646963

  4. Modeling of a three-source perfusion and blood oxygenation sensor for transplant monitoring using multilayer Monte Carlo code

    NASA Astrophysics Data System (ADS)

    Ibey, Bennett L.; Lee, Seungjoon; Ericson, M. Nance; Wilson, Mark A.; Cote, Gerard L.

    2004-06-01

    A Multi-Layer Monte Carlo (MLMC) model was developed to predict the results of in vivo blood perfusion and oxygenation measurement of transplanted organs as measured by an indwelling optical sensor. A sensor has been developed which uses three-source excitation in the red and infrared ranges (660, 810, 940 nm). In vitro data was taken using this sensor by changing the oxygenation state of whole blood and passing it through a single-tube pump system wrapped in bovine liver tissue. The collected data showed that the red signal increased as blood oxygenation increased and infrared signal decreased. The center wavelength of 810 nanometers was shown to be quite indifferent to blood oxygenation change. A model was developed using MLMC code that sampled the wavelength range from 600-1000 nanometers every 6 nanometers. Using scattering and absorption data for blood and liver tissue within this wavelength range, a five-layer model was developed (tissue, clear tubing, blood, clear tubing, tissue). The theoretical data generated from this model was compared to the in vitro data and showed good correlation with changing blood oxygenation.

  5. [Blood perfusion in different facial acupoint areas and its changes after acupuncture stimulation of Hegu (LI 4) displayed by laser Doppler imager in healthy volunteers].

    PubMed

    Wang, Shu-You; Qu, Xiao-Xiao; Song, Xiao-Jing; Li, Shun-Yue; Ma, Hui-Min; Zhang, Dong

    2012-12-01

    To observe the blood perfusion levels in different facial acupoint regions and changes after acupuncture stimulation of Hegu (LI 4). Thirty healthy volunteer subjects were equally divided into control group and acupuncture group. Blood perfusion levels of different facial acupoint areas were detected using a Laser Doppler Imager. Acupuncture stimulation was applied to bilateral Hegu (LI 4) by using two filiform needles which were manipulated for a while till "Deqi", followed by keeping them in position for 30 min. The needles were then manipulated once again every 10 min. The blood perfusion levels of facial acupoint regions were from 0.73 to 1.17 PU in healthy volunteers, with relatively higher levels being in Juliao (ST 3), Kouheliao (LI 19), Sibai (ST 2) and Chengqi (ST 1) regions and relatively lower levels in Xiaguan (ST 7), Qianzheng (Ex-HN) and Sizhukong (TE 23) regions, but without significant difference between the isonym acupoint areas of the bilateral face in the control group. Following acupuncture stimulation of bilateral Hegu (LI 4), the blood perfusion volumes were remarkably increased in the acupoint regions on bilateral sides of the face (P < 0.05, P < 0.01). Acupuncture of Hegu (LI 4) can effectively increase blood perfusion volume of the acupoint areas of the bilateral face in healthy volunteers.

  6. Impact of Ivabradine on Central Aortic Blood Pressure and Myocardial Perfusion in Patients With Stable Coronary Artery Disease.

    PubMed

    Dillinger, Jean-Guillaume; Maher, Vincent; Vitale, Cristiana; Henry, Patrick; Logeart, Damien; Manzo Silberman, Stephane; Allée, Guillaume; Levy, Bernard I

    2015-12-01

    Treatment of hypertensive patients with β-blockers reduces heart rate and decreases central blood pressure less than other antihypertensive drugs, implying that reducing heart rate without altering brachial blood pressure could increase central blood pressure, explaining the increased cardiovascular risk reported with β-blocker. We describe a randomized, double-blind study to explore whether heart rate reduction with the If inhibitor ivabradine had an impact on central blood pressure. We included 12 normotensive patients with stable coronary artery disease, heart rate ≥70 bpm (sinus rhythm), and stable background β-blocker therapy. Patients received ivabradine 7.5 mg BID or matched placebo for two 3-week periods with a crossover design and evaluation by aplanation tonometry. Treatment with ivabradine was associated with a significant reduction in resting heart rate after 3 weeks versus no change with placebo (-15.8±7.7 versus +0.3±5.8 bpm; P=0.0010). There was no relevant between-group difference in change in central aortic systolic blood pressure (-4.0±9.6 versus +2.4±12.0 mm Hg; P=0.13) or augmentation index (-0.8±10.0% versus +0.3±7.6%; P=0.87). Treatment with ivabradine was associated with a modest increase in left ventricular ejection time (+18.5±17.8 versus +2.8±19.3 ms; P=0.074) and a prolongation of diastolic perfusion time (+215.6±105.3 versus -3.0±55.8 ms with placebo; P=0.0005). Consequently, ivabradine induced a pronounced increase in Buckberg index, an index of myocardial viability (+39.3±27.6% versus -2.5±13.5% with placebo; P=0.0015). In conclusion, heart rate reduction with ivabradine does not increase central aortic blood pressure and is associated with a marked prolongation of diastolic perfusion time and an improvement in myocardial perfusion index. URL: https://www.clinicaltrialsregister.eu. Unique identifier: 2011-004779-35. © 2015 American Heart Association, Inc.

  7. (Semi-)quantitative analysis of reduced nicotinamide adenine dinucleotide fluorescence images of blood-perfused rat heart.

    PubMed Central

    Coremans, J M; Ince, C; Bruining, H A; Puppels, G J

    1997-01-01

    In vivo analysis of the metabolic state of tissue by means of reduced nicotinamide adenine dinucleotide (NADH) fluorimetry is disturbed by tissue movements and by hemodynamic and oximetric effects. These factors cause changes in the absorption of ultraviolet (UV) excitation light by the tissue. Many different methods have been used in the literature to compensate measured NADH fluorescence intensities for these effects. In this paper we show on theoretical grounds that the ratio of NADH fluorescence intensity and UV diffuse reflectance intensity provides a (semi-)quantitative measure of tissue NADH concentrations. This result is corroborated by experiments with tissue phantoms in which absorption and back-scattering properties were varied. Furthermore, we have verified the validity of this compensation method in isolated Langendorff-perfused rat heart preparations. In this preparation oximetric effects (of blood and tissue) are the major determinants of the metabolism-dependent UV diffuse reflectance change. Hemodynamic effects accompanying compensatory vasodilation are negligible. Movement artifacts were eliminated by simultaneously recording fluorescence and reflectance images, using a CCD camera with a biprism configuration. The results show that the NADH fluorescence/UV reflectance ratio can be used to monitor the mitochondrial redox state of the surface of intact blood-perfused myocardium. Images FIGURE 1 FIGURE 3 FIGURE 4 PMID:9083689

  8. A high performance biometric signal and image processing method to reveal blood perfusion towards 3D oxygen saturation mapping

    NASA Astrophysics Data System (ADS)

    Imms, Ryan; Hu, Sijung; Azorin-Peris, Vicente; Trico, Michaël.; Summers, Ron

    2014-03-01

    Non-contact imaging photoplethysmography (PPG) is a recent development in the field of physiological data acquisition, currently undergoing a large amount of research to characterize and define the range of its capabilities. Contact-based PPG techniques have been broadly used in clinical scenarios for a number of years to obtain direct information about the degree of oxygen saturation for patients. With the advent of imaging techniques, there is strong potential to enable access to additional information such as multi-dimensional blood perfusion and saturation mapping. The further development of effective opto-physiological monitoring techniques is dependent upon novel modelling techniques coupled with improved sensor design and effective signal processing methodologies. The biometric signal and imaging processing platform (bSIPP) provides a comprehensive set of features for extraction and analysis of recorded iPPG data, enabling direct comparison with other biomedical diagnostic tools such as ECG and EEG. Additionally, utilizing information about the nature of tissue structure has enabled the generation of an engineering model describing the behaviour of light during its travel through the biological tissue. This enables the estimation of the relative oxygen saturation and blood perfusion in different layers of the tissue to be calculated, which has the potential to be a useful diagnostic tool.

  9. Potential of optical microangiography to monitor cerebral blood perfusion and vascular plasticity following traumatic brain injury in mice in vivo

    NASA Astrophysics Data System (ADS)

    Jia, Yali; Alkayed, Nabil; Wang, Ruikang K.

    2009-07-01

    Optical microanglography (OMAG) is a recently developed imaging modality capable of volumetric imaging of dynamic blood perfusion, down to capillary level resolution, with an imaging depth up to 2.00 mm beneath the tissue surface. We report the use of OMAG to monitor the cerebral blood flow (CBF) over the cortex of mouse brain upon traumatic brain injury (TBI), with the cranium left intact, for a period of two weeks on the same animal. We show the ability of OMAG to repeatedly image 3-D cerebral vasculatures during pre- and post-traumatic phases, and to visualize the changes of regulated CBF and the vascular plasticity after TBI. The results indicate the potential of OMAG to explore the mechanism involved in the rehabilitation of TBI.

  10. The measurement of dog gastric mucosal blood flow by radioactive aniline clearance compared with amidopyrine clearance

    PubMed Central

    Curwain, B. P.; Holton, Pamela

    1973-01-01

    1. Methods for the estimation of radioactive aniline in body fluids are described. The recovery of aniline added to blood, plasma and gastric juice was over 90% of the recovery from saline. 2. In the doses used aniline caused methaemoglobinaemia of 5-11% of total haemoglobin. No other effect was detected. Gastric secretion was also unaffected. 3. Aniline clearance increased in parallel with acid secretion from Heidenhain pouches in conscious dogs and in anaesthetized dogs. In conscious dogs the ratio of aniline clearance to acid secretion was significantly higher for histamine stimulation than for pentagastrin stimulation. 4. Aniline and amidopyrine clearances were compared simultaneously in the same dogs. Aniline clearance was about 80% of amidopyrine clearance. 5. The proportion of aniline bound to plasma proteins was measured by two methods and found to be 25%. When aniline clearance was corrected for plasma binding, aniline and amidopyrine clearances were equal. PMID:4689959

  11. Improved cerebral oxygen saturation and blood flow pulsatility with pulsatile perfusion during pediatric cardiopulmonary bypass.

    PubMed

    Su, Xiaowei W; Guan, Yulong; Barnes, Mollie; Clark, J Brian; Myers, John L; Undar, Akif

    2011-08-01

    Brain monitoring techniques near-infrared spectroscopy (NIRS) and transcranial Doppler (TCD) ultrasound were used in pediatric patients undergoing cardiopulmonary bypass for congenital heart defect (CHD) repair to analyze the effect of pulsatile or nonpulsatile flow on brain protection. Regional cerebral oxygen saturation (rSO2) and cerebrovascular pulsatility index (PI) were measured by NIRS and TCD, respectively, in 111 pediatric patients undergoing bypass for CHD repair randomized to pulsatile (n = 77) or nonpulsatile (n = 34) perfusion. No significant differences in demographic and intraoperative data, including surgical risk stratification, existed between groups. Patients undergoing pulsatile perfusion had numerically lower decreases in rSO2 from baseline for all time points analyzed compared with the nonpulsatile group, with significant ∼12% lower decreases at 40 and 60 min after crossclamp. Patients undergoing pulsatile perfusion had numerically lower decreases in PI from baseline for the majority of time points compared with the nonpulsatile group, with significant ∼30% lower decreases between 5 and 40 min after crossclamp. Pulsatile flow has advantages over nonpulsatile flow as measured by NIRS and TCD, especially at advanced time points, which may improve postoperative neurodevelopmental outcomes.

  12. Microfluidic assay of platelet deposition on collagen by perfusion of whole blood from healthy individuals taking aspirin.

    PubMed

    Li, Ruizhi; Fries, Susanne; Li, Xuanwen; Grosser, Tilo; Diamond, Scott L

    2013-08-01

    Microfluidic devices can create hemodynamic conditions for platelet assays. We validated an 8-channel device in a study of interdonor response to acetylsalicylic acid (ASA, aspirin) with whole blood from 28 healthy individuals. Platelet deposition was assessed before treatment or 24 h after ingestion of 325 mg ASA. Whole blood (plus 100 μmol/L H-d-Phe-Pro-Arg-chloromethylketone to inhibit thrombin) was further treated ex vivo with ASA (0-500 μmol/L) and perfused over fibrillar collagen for 300 s at a venous wall shear rate (200 s(-1)). Ex vivo ASA addition to blood drawn before aspirin ingestion caused a reduction in platelet deposition [half-maximal inhibitory concentration (IC50) approximately 10-20 μmol/L], especially between 150 and 300 s of perfusion, when secondary aggregation mediated by thromboxane was expected. Twenty-seven of 28 individuals displayed smaller deposits (45% mean reduction; range 10%-90%; P < 0.001) from blood obtained 24 h after ASA ingestion (no ASA added ex vivo). In replicate tests, an R value to score secondary aggregation [deposition rate from 150 to 300 s normalized by rate from 60 to 150 s] showed R < 1 in only 2 of 28 individuals without ASA ingestion, with R > 1 in only 3 of 28 individuals after 500 μmol/L ASA addition ex vivo. At 24 h after ASA ingestion, 21 of 28 individuals displayed poor secondary aggregation (R < 1) without ex vivo ASA addition, whereas the 7 individuals with residual secondary aggregation (R > 1) displayed insensitivity to ex vivo ASA addition. Platelet deposition was not correlated with platelet count. Ex vivo ASA addition caused similar inhibition at venous and arterial wall shear rates. Microfluidic devices quantified platelet deposition after ingestion or ex vivo addition of aspirin.

  13. Comparison of Cerebral Oxygen Saturation and Cerebral Perfusion Computed Tomography in Cerebral Blood Flow in Patients with Brain Injury.

    PubMed

    Trofimov, Alexey O; Kalentiev, George; Voennov, Oleg; Grigoryeva, Vera

    2016-01-01

    The purpose of this study was to determine the relationship between cerebral tissue oxygen saturation and cerebral blood volume in patients with traumatic brain injury. Perfusion computed tomography of the brain was performed in 25 patients with traumatic brain injury together with simultaneous SctO2 level measurement using cerebral near-infrared oxymetry. The mean age of the injured persons was 34.5±15.6 years (range 15-65); 14 men, 11 women. The Injury Severity Score (ISS) values were 44.4±9.7 (range 25-81). The Glasgow Coma Score (GCS) mean value before the study was 10.6±2.1 (range 5-13). SctO2 ranged from 51 to 89%, mean 62±8.2%. Cerebral blood volume (CBV) values were 2.1±0.67 ml/100 g (min 1.1; max 4.3 ml/100 g). Cerebral blood flow (CBF) was 31.99±13.6 ml/100 g×min. Mean transit time (MTT) values were 5.7±4.5 s (min 2.8; max 34.3 s). The time to peak (TTP) was 22.2±3.1 s. A statistically significant correlation was found between SctO2 level and cerebral blood volume (CBV) level (R=0.9; p<0.000001). No other significant correlations were found between brain tissue oxygenation and other parameters of brain perfusion.

  14. Mucosal vaccines

    PubMed Central

    Nizard, Mevyn; Diniz, Mariana O; Roussel, Helene; Tran, Thi; Ferreira, Luis CS; Badoual, Cecile; Tartour, Eric

    2014-01-01

    The mucosal immune system displays several adaptations reflecting the exposure to the external environment. The efficient induction of mucosal immune responses also requires specific approaches, such as the use of appropriate administration routes and specific adjuvants and/or delivery systems. In contrast to vaccines delivered via parenteral routes, experimental, and clinical evidences demonstrated that mucosal vaccines can efficiently induce local immune responses to pathogens or tumors located at mucosal sites as well as systemic response. At least in part, such features can be explained by the compartmentalization of mucosal B and T cell populations that play important roles in the modulation of local immune responses. In the present review, we discuss molecular and cellular features of the mucosal immune system as well as novel immunization approaches that may lead to the development of innovative and efficient vaccines targeting pathogens and tumors at different mucosal sites. PMID:25424921

  15. Antegrade selective cerebral perfusion combined with deep hypothermic circulatory arrest on cerebral circulation: comparison between pulsatile and nonpulsatile blood flows.

    PubMed

    Soeda, Masao

    2007-04-01

    In aortic arch surgeries, antegrade selective cerebral perfusion (SCP) combined with deep hypothermic circulatory arrest (DHCA) has been recently widely used in institutions as one of the most reliable methods for cerebral protection. However, some studies reported a 3.7-9.3% incidence of postoperative cerebral complications. To perform antegrade SCP more safely, we sought to examine the impact of pulsatile flow perfusion during DHCA on cerebral tissue metabolism, focusing on physiological effects of pulsatile flow perfusion. Sixteen pigs were divided into 2 groups. In each group, antegrade SCP combined with DHCA was conducted. During circulatory arrest, for SCP, a pulsatile flow (group P) and a nonpulsatile flow (group N) were used. We compared results between group P and group N. Jugular venous oxygen saturation (SjO(2)) and cerebral tissue oxygen partial pressure (PtO(2)) were measured at baseline, and continuously throughout the extracorporeal circulation. Hematocrit (Ht), and concentrations of S-100 protein and CK-BB in blood and the cerebrospinal fluid (CSF) were measured at baseline (before the beginning of extracorporeal circulation), following SCP, and after rewarming. Following rewarming, each brain under perfused fixation was removed, and histopathological examinations were conducted using Kluver-Barrera and Tunnel staining methods, electron micrograph. SjO(2) was found to be within normal ranges until after SCP, but decreased with rewarming in both groups. In Group N, changes in SjO(2) were significant, with a decrease to < or =50%. In Group N, concentrations of S-100 protein and CK-BB in CSF after SCP and after rewarming were significantly higher than those in Group P. The time needed for rewarming to 36 degrees C in Group P was shorter than that in Group N. Our results suggest that the pulsatile flow circulation method shows cerebral protection effects with increasing blood flow in small cerebral tissues. In addition, it is effective for improving the

  16. 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.

  17. Comparison of the Effect of Vessel Size Imaging and Cerebral Blood Volume Derived from Perfusion MR Imaging on Glioma Grading.

    PubMed

    Kang, H-Y; Xiao, H-L; Chen, J-H; Tan, Y; Chen, X; Xie, T; Fang, J-Q; Wang, S; Yang, Y; Zhang, W-G

    2016-01-01

    Vascular proliferation is a major criterion for grading gliomas on the basis of histology. Relative cerebral blood volume can provide pathophysiologic information about glioma grading. Vessel size imaging, in some animals, can be used to estimate the microvascular caliber of a glioma, but its clinical use remains unclear. Herein, we aimed to compare the predictive power of relative cerebral blood volume and vessel size imaging in glioma grading, with grading based on histology. Seventy patients with glioma participated in the study; 30 patients underwent MR perfusion imaging with a spin-echo sequence and vessel size imaging with a gradient-echo and spin-echo sequence successively at 24-hour intervals before surgery. We analyzed the vessel size imaging values and relative cerebral blood volume of differently graded gliomas. The microvessel parameters were histologically evaluated and compared with those on MR imaging. The cutoff values of vessel size imaging and relative cerebral blood volume obtained from receiver operating characteristic curve analyses were used to predict glioma grading in another 40 patients. Vessel size imaging values and relative cerebral blood volume were both increased in high-grade gliomas compared with low-grade gliomas (P < .01). Moreover, vessel size imaging values had higher specificity and sensitivity in differentiating high-grade from low-grade gliomas compared with relative cerebral blood volume. In addition, a significant correlation was observed between vessel size imaging values and microvessel diameters (r > 0.8, P < .05) and between relative cerebral blood volume and microvessel area (r = 0.6579, P < .05). Most important, the use of vessel size imaging cutoff values to predict glioma grading was more accurate (100%) than use of relative cerebral blood volume (85%) values. Vessel size imaging can provide more accurate information on glioma grading and may serve as an effective biomarker for the prognosis of patients with gliomas

  18. PLASMA EXPANDER AND BLOOD STORAGE EFFECTS ON CAPILLARY PERFUSION IN TRANSFUSION FOLLOWING HEMORRHAGE

    PubMed Central

    Hightower, C. Makena; Salazar Vázquez, Beatriz Y.; Cabrales, Pedro; Tsai, Amy G.; Acharya, Seetharama A.; Intaglietta, Marcos

    2014-01-01

    BACKGROUND Treating hemorrhage with blood transfusions in subjects previously hemodiluted with different colloidal plasma expanders, using fresh autologous blood or 2-weeks stored blood, allows identifying the interaction between type of plasma expander and differences in blood storage. STUDY DESIGN AND METHODS Studies used the hamster window chamber model. Fresh autologous plasma, 130 kDa starch based plasma expander (HES), or 4% polyethylene glycol conjugated albumin (PEG-Alb) were used for 20% of blood volume hemodilution. Hemodilution was followed by a 55% by blood volume 40 min hemorrhagic shock period, treated with transfusion of fresh or 2-weeks stored blood. Outcome was evaluated one hour post blood transfusion in terms of microvascular and systemic parameters. RESULTS Results were principally dependent on the type of colloidal solution used during hemodilution, 4% PEG-Alb yielding the best microvascular recovery evaluated in terms of the functional capillary density. This result was consistent whether fresh blood or stored blood was used in treating the subsequent shock period. Fresh blood results were significantly better in systemic and microvascular terms relative to stored blood. HES and fresh plasma hemodilution yielded less favorable results, a difference that was enhanced when fresh vs. stored blood were compared in their efficacy of correcting the subsequent hemorrhage. CONCLUSION The type of plasma expander used for hemodilution influences the short term outcome of subsequent volume resuscitation using blood transfusion; 4% PEG-Alb providing the most favorable outcome by comparison to HES or fresh plasma. PMID:22554380

  19. Effect of combined VEGF165/ SDF-1 gene therapy on vascular remodeling and blood perfusion in cerebral ischemia.

    PubMed

    Hu, Guo-Jie; Feng, Yu-Gong; Lu, Wen-Peng; Li, Huan-Ting; Xie, Hong-Wei; Li, Shi-Fang

    2016-12-16

    OBJECTIVE Therapeutic neovascularization is a promising strategy for treating patients after an ischemic stroke; however, single-factor therapy has limitations. Stromal cell-derived factor 1 (SDF-1) and vascular endothelial growth factor (VEGF) proteins synergistically promote angiogenesis. In this study, the authors assessed the effect of combined gene therapy with VEGF165 and SDF-1 in a rat model of cerebral infarction. METHODS An adenoviral vector expressing VEGF165 and SDF-1 connected via an internal ribosome entry site was constructed (Ad- VEGF165-SDF-1). A rat model of middle cerebral artery occlusion (MCAO) was established; either Ad- VEGF165-SDF-1 or control adenovirus Ad- LacZ was stereotactically microinjected into the lateral ventricle of 80 rats 24 hours after MCAO. Coexpression and distribution of VEGF165 and SDF-1 were examined by reverse-transcription polymerase chain reaction, Western blotting, and immunofluorescence. The neurological severity score of each rat was measured on Days 3, 7, 14, 21, and 28 after MCAO. Angiogenesis and vascular remodeling were evaluated via bromodeoxyuridine and CD34 immunofluorescence labeling. Relative cerebral infarction volumes were determined by T2-weighted MRI and triphenyltetrazolium chloride staining. Cerebral blood flow, relative cerebral blood volume, and relative mean transmit time were assessed using perfusion-weighted MRI. RESULTS The Ad- VEGF165-SDF-1 vector mediated coexpression of VEGF165 and SDF-1 in multiple sites around the ischemic core, including the cortex, corpus striatum, and hippocampal granular layer. Coexpression of VEGF165 and SDF-1 improved neural function, reduced cerebral infarction volume, increased microvascular density and promoted angiogenesis in the ischemic penumbra, and improved cerebral blood flow and perfusion. CONCLUSIONS Combined VEGF165 and SDF-1 gene therapy represents a potential strategy for improving vascular remodeling and recovery of neural function after cerebral

  20. Countercurrent transfer of dopamine from venous blood in the cavernous sinus to the arterial blood supplying the brain - the perfused rabbit head as an experimental model.

    PubMed

    Muszak, J; Krzymowski, T; Gilun, P; Stefanczyk-Krzymowska, S

    2014-10-01

    The objective of the current study was to check whether countercurrent transfer of dopamine occurs in the cavernous sinus of the rabbit and whether the rabbit can be used as an animal model to study cavernous sinus function. After exsanguination of the animal, oxygenated and warmed (37°C) Hanseneleit-Krebs buffer with autologous or homologous blood (in a 3:1 or 1:1 ratio) was pumped through both common carotid arteries into the head (60 ml/min; 80-100 mm Hg) and radiolabeled dopamine (3(H)-DA, 10 μCi) was infused into the cavernous sinus through the angular oculi vein. Cerebral blood from the basilar artery was collected from the cannulated vertebral artery during 3(H)-DA infusion and for 10 minutes after completion of infusion. Selected brain tissue samples were collected after completion of the head perfusion. It was demonstrated that dopamine can penetrate from the rabbit's cavernous sinus to the internal carotid artery supplying the brain. Dopamine permeation was greater when the rabbit head was perfused with buffer and blood in a 3:1 ratio than with 1:1 (P<0.01). When the head was perfused with buffer and blood in a 3:1 ratio, significant radioactivity was found in samples collected from the brain basilar artery during and after 3(H)-DA infusion (P<0.001). The radioactivity was identified as 34.13 ± 2.7% unmetabolized 3(H)-DA and 65.9 ± 2.7% its metabolites. Significant radioactivity was also found in some brain tissue samples in both groups (P<0.05). The concentration of free radiolabeled dopamine particles in the dialysate of blood plasma and plasma diluted with buffer did not differ significantly. Because the structures of the cavernous sinus and cavernous fragment of the internal carotid artery of the rabbit are similar to those in humans, it suggests that rabbits can serve as a model for experimental physiological studies of cavernous sinus function and retrograde dopamine transfer in the cavernous sinus should be considered as an important link in

  1. Pseudo-continuous arterial spin labeling imaging of cerebral blood perfusion asymmetry in drug-naïve patients with first-episode major depression

    PubMed Central

    Chen, Guangdong; Bian, Haiman; Jiang, Deguo; Cui, Mingwei; Ji, Shengzhang; Liu, Mei; Lang, Xu; Zhuo, Chuanjun

    2016-01-01

    Many previous studies have reported that regional cerebral blood flow (rCBF) aberrations may be one of the pathological characteristics of depression and rCBF has demonstrated a certain degree of asymmetry. However, studies investigating the cerebral blood perfusion asymmetry changes of drug-naïve patients experiencing their first episode of major depression using pseudo-continuous arterial spin labeling (pCASL) are rare. Ten drug-naïve patients experiencing their first major depression episode and 15 healthy volunteers were enrolled in the current study. A novel pCASL method was applied to whole brain MRI scans of all of the samples. The Statistics Parameter Mapping and Relative Expression Software Tool software packages were used for the pre-processing and statistical analysis of the two sets of images, and the differences in the cerebral blood perfusion at the whole brain level were compared between the two groups. Compared with the healthy control group, the cerebral perfusion of the depression patients showed an asymmetric pattern. Decreased cerebral blood perfusion regions were primarily located in the left hemisphere, specifically in the left temporal lobe, frontal lobe and cingulate cortex [P<0.05 and cluster size ≥30 with false discovery rate (FDR) correction]. Simultaneously, increased perfusion regions were predominantly located in the right hemisphere, specifically in the right cerebellum, thalamus, frontal lobe and anterior cingulate cortex (P<0.05 and cluster size ≥30, with FDR correction). Thus, pCASL may characterize the alterations in cerebral blood perfusion of patients with depression. PMID:28101340

  2. Observation of Microvascular Perfusion in the Hegu (LI4) Acupoint Area after Deqi Acupuncture at Quchi (LI11) Acupoint Using Speckle Laser Blood Flow Scanning Technology.

    PubMed

    Huang, Tao; Yang, Li-Jian; Zhang, Wei-Bo; Jia, Shu-Yong; Tian, Yu-Ying; Wang, Guan-Jun; Mu, Xiang; Wang, Lu; Litscher, Gerhard

    2012-01-01

    The aim of this study was to investigate the traditional meridian theory using speckle laser blood flow scanning technology to observe microcirculation of the Hegu acupoint area after acupuncture stimulation on distant points. An observational study was conducted to observe the microvascular perfusion of Hegu (LI4) and control points after acupuncturing Quchi (LI11). Thirty healthy volunteers (mean age 31.6 ± 8.7 years) received deqi acupuncture on Quchi (LI11, right side), and simultaneously changes in microvascular perfusion of Sanjian (LI3), Hegu (LI4), Yangxi (LI5), and two control points were observed before, during, and after needling using a MOOR speckle laser. The results showed that the changes in microvascular perfusion of the observed points are not regular. After correction, the experiment showed that the blood perfusion on 3 meridian acupoints was increased while the perfusion on 2 control points was decreased following acupuncture stimulation, the changes at Hegu (LI4) being the statistically most significant ones. Deqi acupuncture can help in regulating the body's blood flow, with a certain degree of meridian specificity.

  3. Observation of Microvascular Perfusion in the Hegu (LI4) Acupoint Area after Deqi Acupuncture at Quchi (LI11) Acupoint Using Speckle Laser Blood Flow Scanning Technology

    PubMed Central

    Huang, Tao; Yang, Li-Jian; Zhang, Wei-Bo; Jia, Shu-Yong; Tian, Yu-Ying; Wang, Guan-Jun; Mu, Xiang; Wang, Lu; Litscher, Gerhard

    2012-01-01

    The aim of this study was to investigate the traditional meridian theory using speckle laser blood flow scanning technology to observe microcirculation of the Hegu acupoint area after acupuncture stimulation on distant points. An observational study was conducted to observe the microvascular perfusion of Hegu (LI4) and control points after acupuncturing Quchi (LI11). Thirty healthy volunteers (mean age 31.6 ± 8.7 years) received deqi acupuncture on Quchi (LI11, right side), and simultaneously changes in microvascular perfusion of Sanjian (LI3), Hegu (LI4), Yangxi (LI5), and two control points were observed before, during, and after needling using a MOOR speckle laser. The results showed that the changes in microvascular perfusion of the observed points are not regular. After correction, the experiment showed that the blood perfusion on 3 meridian acupoints was increased while the perfusion on 2 control points was decreased following acupuncture stimulation, the changes at Hegu (LI4) being the statistically most significant ones. Deqi acupuncture can help in regulating the body's blood flow, with a certain degree of meridian specificity. PMID:23258991

  4. Pulse-pressure-enhancing controller for better physiologic perfusion of rotary blood pumps based on speed modulation.

    PubMed

    Huang, Feng; Ruan, Xiaodong; Fu, Xin

    2014-01-01

    Sufficient pulsation is important for physiologic perfusion if adequate flow is to be guaranteed. A fuzzy control method for rotary blood pumps using active speed modulation is proposed in this article. It maintains the mean aortic pressure to provide sufficient perfusion while it simultaneously enhances the pulse pressure. The controller uses the indices extracted from the aortic pressure as feedback to determine the amplitude and offset of the rectangular speed modulation waveform, which is synchronous with the cardiac cycle. An additional algorithm is included to prevent regurgitation. The controller is tested both in a baroreflex-cardiovascular model and in a preliminary in vitro experiment. Simulation results demonstrate that the controller is able to increase the pulse pressure to approximately 20 mm Hg and at the same time maintains the mean pressure at 100 mm Hg, when heart failure occurs. It is also quite robust under various physiologic disturbances. Experimental results show that the speed modulation can be implemented in real pumps and that the controller is feasible in practice.

  5. Effects of cardioplegia induced by a Young's solution (YNG solution) on the blood-perfused canine papillary muscle preparation.

    PubMed

    Satoh, H; Ohkubo, K; Suzuki, K; Katano, Y; Otorii, T; Kawada, T; Yoshida, S; Imai, S

    1984-03-01

    Experiments were carried out in the blood-perfused canine papillary muscle preparation to evaluate the protective effect of a cardioplegic solution, Young's solution (YNG solution), on the myocardial function. Both in spontaneously contracting preparations and in electrically paced (2 Hz) preparations, the time to the cardiac arrest and the time to the maximum blood flow were found to be significantly shorter when the cardiac arrest was induced with cardioplegic solutions than when it was induced with the cold modified Krebs-Ringer's solution (cold cardioplegia). The maximum blood flow of the paced preparation tended to be greater with cardioplegic solutions. The time to resumption of regular contractions was significantly shorter with YNG solution as compared with cold cardioplegia. The developed tension and the blood flow at the time of resumption of the regular contractions tended to approach the control value more quickly with YNG solution, as compared with other cardioplegic solutions and cold cardioplegia. It is concluded that YNG solution represents an optimal cardioplegic solution.

  6. Intravital lectin perfusion analysis of vascular permeability in human micro- and macro- blood vessels.

    PubMed

    Debbage, P L; Sölder, E; Seidl, S; Hutzler, P; Hugl, B; Ofner, D; Kreczy, A

    2001-10-01

    We previously applied intravital lectin perfusion in mouse models to elucidate mechanisms underlying vascular permeability. The present work transfers this technique to human models, analysing vascular permeability in macro- and microvessels. Human vascular endothelial surface carbohydrate biochemistry differs significantly from its murine counterpart, lacking alpha-galactosyl epitopes and expressing the L-fucose moiety in the glycocalyx; the poly-N-lactosamine glycan backbone is common to all mammals. We examined extensively lectin binding specificities in sections and in vivo, and then applied the poly-N-lactosamine-specific lectin LEA and the L-fucose-specific lectin UEA-I in human intravital perfusions. Transendothelial transport differed in macrovessels and microvessels. In microvessels of adult human fat tissue, rectal wall and rectal carcinomas, slow transendothelial transport by vesicles was followed by significant retention at the subendothelial basement membrane; paracellular passage was not observed. Passage time exceeded 1 h. Thus we found barrier mechanisms resembling those we described previously in murine tissues. In both adult and fetal macrovessels, the vena saphena magna and the umbilical vein, respectively, rapid passage across the endothelial lining was observed, the tracer localising completely in the subendothelial tissues within 15 min; vesicular transport was more rapid than in microvessels, and retention at the subendothelial basement membrane briefer.

  7. Comparative imaging of differential pulmonary blood flow in patients with congenital heart disease: magnetic resonance imaging versus lung perfusion scintigraphy.

    PubMed

    Roman, Kevin S; Kellenberger, Christian J; Farooq, Saqba; MacGowan, Christopher K; Gilday, David L; Yoo, Shi-Joon

    2005-03-01

    Lung perfusion scintigraphy is considered the gold standard to assess differential pulmonary blood flow while magnetic resonance (MR) has been shown to be an accurate alternative in some studies. The purpose of the study was to assess the accuracy of phase contrast magnetic resonance (PC-MR) in measuring pulmonary blood flow ratio compared with lung perfusion scintigraphy in patients with complex pulmonary artery anatomy or pulmonary hypertension and to document reasons for discrepant results. We identified 25 cases of congenital heart disease between January 2000 and 2003, in whom both techniques of assessing pulmonary blood flow were performed within a 6-month period without an interim surgical or transcatheter intervention. The study group included cases with branch pulmonary artery stenosis, intracardiac shunts, single ventricle circulation, pulmonary venous anomalies and conotruncal defects. The mean age at study was 5.7 years (range 0.33-12) with a mean weight of 20.3 kg (range 6.5-53.6). The two methods were compared using a Bland-Altman analysis, and the Pearson correlation coefficient was calculated using the lung scan as the gold standard. Discrepant results were examined by reviewing the source images to elucidate reasons for error by MR. Bland-Altman analysis comparing right pulmonary artery (RPA) blood flow percentage, as measured by each modality, showed a mean difference of 1.43+/-9.8 (95% limits of agreement: -17.8, 20.6) with a correlation coefficient of r=0.84, P<0.0001. In six (24%) cases a large difference (>10%) was found with a mean difference between techniques of 17.9%. The reasons for discrepant results included MR artifacts, dephasing owing to turbulent flow, site of data acquisition and lobar lung collapse. When using PC-MR to assess pulmonary blood flow ratio, important technical errors occur in a significant proportion of patients who have abnormal pulmonary artery anatomy or pulmonary hypertension. If these technical errors are avoided

  8. Modulation of resting brain cerebral blood flow by the GABA B agonist, baclofen: A longitudinal perfusion fMRI study

    PubMed Central

    Franklin, Teresa R.; Wang, Ze; Sciortino, Nathan; Harper, Derek; Li, Yin; Hakun, Jonathan; Kildea, Susan; Kampman, Kyle; Ehrman, Ron; Detre, John A.; O’Brien, Charles P.; Childress, Anna Rose

    2011-01-01

    Background Preclinical studies confirm that the GABA B agonist, baclofen blocks dopamine release in the reward-responsive ventral striatum (VS) and medial prefrontal cortex, and consequently, blocks drug motivated behavior. Its mechanism in humans is unknown. Here, we used continuous arterial spin labeled (CASL) perfusion fMRI to examine baclofen’s effects on blood flow in the human brain. Methods Twenty-one subjects (all smokers, 12 females) were randomized to receive either baclofen (80 mg/day; N = 10) or placebo (N = 11). A five minute quantitative perfusion fMRI resting baseline (RB) scan was acquired at two time points; prior to the dosing regimen (Time 1) and on the last day of 21 days of drug administration (Time 2). SPM2 was employed to compare changes in RB from Time 1 to 2. Results Baclofen diminished cerebral blood flow (CBF) in the VS and mOFC and increased it in the lateral OFC, a region involved in suppressing previously rewarded behavior. CBF in bilateral insula was also blunted by baclofen (T values ranged from −11.29 to 15.3 at p = 0.001, 20 contiguous voxels). CBF at Time 2 was unchanged in placebo subjects. There were no differences between groups in side effects or cigarettes smoked per day (at either time point). Conclusions Baclofen’s modulatory actions on regions involved in motivated behavior in humans are reflected in the resting state and provide insight into the underlying mechanism behind its potential to block drug-motivated behavior, in preclinical studies, and its putative effectiveness as an anti-craving/anti-relapse agent in humans. PMID:21333466

  9. Intraoperative blood pressure and cerebral perfusion: strategies to clarify hemodynamic goals.

    PubMed

    Williams, Monica; Lee, Jennifer K

    2014-07-01

    Blood pressure can vary considerably during anesthesia. If blood pressure falls outside the limits of cerebrovascular autoregulation, children can become at risk of cerebral ischemic or hyperemic injury. However, the blood pressure limits of autoregulation are unclear in infants and children, and these limits can shift after brain injury. This article will review autoregulation, considerations for the hemodynamic management of children with brain injuries, and research on autoregulation monitoring techniques.

  10. Assay of lysergic acid diethylamide and its passage from blood into the perfused cerebral ventricles

    PubMed Central

    Dras̆koci, M.

    1960-01-01

    On the isolated rat uterus, lysergic acid diethylamide had an oxytocic action in a concentration of 2×10-8; in smaller concentrations (10-9 to 10-10), which had no stimulating effect of their own, it potentiated acetylcholine-induced contractions. This potentiating effect was made the basis for assaying minute amounts of lysergic acid diethylamide. The method was used to assay this substance in plasma of cats during its intravenous infusion at a rate of 10 μg./min./kg. During these infusions 0.4 to 2 ng./min. of lysergic acid diethylamide passed into the cerebral ventricles perfused with a salt solution of a composition resembling that of cerebrospinal fluid. PMID:13818017

  11. Rapid onset of perfused blood vessels after implantation of ECFCs and MPCs in collagen, PuraMatrix and fibrin provisional matrices.

    PubMed

    Allen, Patrick; Kang, Kyu-Tae; Bischoff, Joyce

    2015-05-01

    We developed an in vivo vascularization model in which human endothelial colony-forming cells (ECFCs) and human mesenchymal progenitor cells (MPCs) form blood vessel networks when co-injected (ECFC + MPC) into nude mice in rat tail type I collagen, bovine fibrin or synthetic peptide PuraMatrix matrices. We used three approaches to determine the onset of functional vascularization when ECFC + MPC suspended in these matrices were implanted in vivo. The first was immunohistochemistry to detect vessels lined by human endothelial cells and filled with red blood cells. The second was in vivo vascular staining by tail vein injection of a mixture of Ulex europaeus agglutinin I (UEA-I), a lectin specific for human endothelium, and Griffonia simplicifolia isolectin B4 (GS-IB4 ), a lectin specific for rodent endothelium. The third approach employed contrast-enhanced ultrasound to measure the perfusion volumes of implants in individual animals over time. Human endothelial-lined tubular structures were detected in vivo on days 1 and 2 after implantation, with perfused human vessels detected on days 3 and 4. Contrast-enhanced ultrasound revealed significant perfusion of ECFC + MPC/collagen implants on days 1-4, at up to 14% perfused vascular volume. ECFC + MPC implanted in fibrin and PuraMatrix matrices also supported perfusion at day 1, as assessed by ultrasound (at 12% and 23% perfused vascular volume, respectively). This model demonstrates that ECFC + MPC suspended in any of the three matrices initiated a rapid onset of vascularization. We propose that ECFC + MPC delivered in vivo provide a means to achieve rapid perfusion of tissue-engineered organs or for in situ tissue repair.

  12. The effect of blood perfusion rate on the temperature distributions induced by multiple, scanned and focused ultrasonic beams in dogs' kidneys in vivo.

    PubMed

    Hynynen, K; DeYoung, D; Kundrat, M; Moros, E

    1989-01-01

    The effect of blood perfusion rate on the temperature distribution during scanned, focused ultrasound hyperthermia was investigated using an in vivo dog kidney model. The results showed that the ultrasound beams could penetrate through the body wall without severe distortion, and that they could be used to induce controlled temperature elevations in the target volume. The blood perfusion rate of the heated tissue significantly modified the temperature distribution and the temperatures achieved in the kidney with no flow were about five times higher than in the case with full flow for the same applied acoustic power. It was also demonstrated that the power deposition pattern produced by scanned focused ultrasonic fields could be modified to give an acceptable temperature distribution in different perfusion situations. Similar trends were also obtained by using the bioheat transfer equation to simulate the experiment. Both the magnitude of the temperature elevations and the effect of perfusion on the temperature distributions obtained in the experiments were in agreement with the simulations. The main difference occurred at high perfusion rates where the experiments showed significant temperature elevation outside of the scanned volume and the simulation results predicted hardly any temperature increase 5 mm outside the scan. These observations indicate that both the theoretical power calculation programme and the temperature simulations will have value in the design of optimal heating systems, treatment planning and in the retrospective of the achieved temperature distributions.

  13. [Abnormal cerebral blood flow distributions during the post-ictal phase of febrile status epilepticus in three pediatric patients measured by arterial spin labeling perfusion MRI].

    PubMed

    Hirano, Keiko; Fukuda, Tokiko

    2016-05-01

    The ability to visualize brain perfusion is important for identifying epileptic foci. We present three pediatric cases showing asymmetrical cerebral blood flow (CBF) distributions during the post-ictal phase of febrile status epilepticus measured by arterial spin labeling (ASL) perfusion MRI. During the acute phase, regional CBF measurements in the areas considered including epileptic foci were higher than in the corresponding area of the contralateral hemisphere, though the exact quantitative value varied between cases. We could not identify the correct epileptogenic foci, because those ASL images were taken after the prolonged and extraordinary activation of neurons in the affected area. During the recovery phase, the differences reduced and the average regional CBF measurement was 54.6 ± 6.1 ml/100 g per minute, which was a little less than the number of previous ASL studies. ASL perfusion MRI imaging provides a method for evaluating regional CBF by using magnetically labeled arterial blood water as an endogenous tracer. With this technique, we can repeatedly evaluate both the brain structure and the level of perfusion at the same time. ASL is noninvasive and easily accessible, and therefore it could become a routine tool for assessment of perfusion in daily practice of pediatric neurology.

  14. The relationship between exercise-induced muscle fatigue, arterial blood flow and muscle perfusion after 56 days local muscle unloading.

    PubMed

    Weber, Tobias; Ducos, Michel; Mulder, Edwin; Beijer, Åsa; Herrera, Frankyn; Zange, Jochen; Degens, Hans; Bloch, Wilhelm; Rittweger, Jörn

    2014-05-01

    In the light of the dynamic nature of habitual plantar flexor activity, we utilized an incremental isokinetic exercise test (IIET) to assess the work-related power deficit (WoRPD) as a measure for exercise-induced muscle fatigue before and after prolonged calf muscle unloading and in relation to arterial blood flow and muscle perfusion. Eleven male subjects (31 ± 6 years) wore the HEPHAISTOS unloading orthosis unilaterally for 56 days. It allows habitual ambulation while greatly reducing plantar flexor activity and torque production. Endpoint measurements encompassed arterial blood flow, measured in the femoral artery using Doppler ultrasound, oxygenation of the soleus muscle assessed by near-infrared spectroscopy, lactate concentrations determined in capillary blood and muscle activity using soleus muscle surface electromyography. Furthermore, soleus muscle biopsies were taken to investigate morphological muscle changes. After the intervention, maximal isokinetic torque was reduced by 23·4 ± 8·2% (P<0·001) and soleus fibre size was reduced by 8·5 ± 13% (P = 0·016). However, WoRPD remained unaffected as indicated by an unchanged loss of relative plantar flexor power between pre- and postexperiments (P = 0·88). Blood flow, tissue oxygenation, lactate concentrations and EMG median frequency kinematics during the exercise test were comparable before and after the intervention, whereas the increase of RMS in response to IIET was less following the intervention (P = 0·03). In conclusion, following submaximal isokinetic muscle work exercise-induced muscle fatigue is unaffected after prolonged local muscle unloading. The observation that arterial blood flow was maintained may underlie the unchanged fatigability.

  15. Assessment of the selectivity of OPC-2009, a new β2-adrenoceptor stimulant, by the use of the blood-perfused trachea in situ and of the isolated blood-perfused papillary muscle of the dog

    PubMed Central

    Himori, N.; Taira, N.

    1977-01-01

    1 The potency and selectivity of 5-(1-hydroxy-2-isopropylamino)butyl-8-hydroxy carbostyril hydrochloride hemihydrate (OPC-2009), a new β2-adrenoceptor stimulant, was compared with those of isoprenaline, trimetoquinol and salbutamol by the use of blood-perfused tracheal preparations in situ and of blood-perfused papillary muscle preparations of the dog. All drugs were injected intra-arterially. 2 All the four drugs decreased tracheal intraluminal pressure (tracheal relaxation) and increased tracheal blood flow in a dose-dependent manner. The four drugs produced a dose-dependent increase in developed tension of papillary muscles. In both preparations the duration of action of isoprenaline and salbutamol was short, whereas that of OPC-2009 and trimetoquinol was long. These effects were antagonized by propranolol. 3 Dose-response curves to the four drugs for tracheal relaxation were almost parallel. OPC-2009 was 2.4 times more potent, and trimetoquinol and salbutamol were 2.2 and 6.2 times less potent than isoprenaline in causing tracheal relaxation. 4 Dose-response curves to the four drugs for tracheal vasodilatation were also parallel. OPC-2009, trimetoquinol and salbutamol were 3.9, 6.7 and 23 times less potent than isoprenaline. 5 Slopes of the dose-response curves to the four drugs for increased developed tension were not parallel; that of OPC-2009 was the least steep, whereas that of isoprenaline was the steepest. Trimetoquinol, salbutamol and OPC-2009 were about 18, 570 and 2400 times less potent than isoprenaline. 6 Selectivity calculated from relative potencies indicate that OPC-2009 was about 6000 times, salbutamol about 92 times and trimetoquinol about 8.2 times more selective than isoprenaline for tracheal smooth muscle as compared to ventricular muscle. 7 The high potency and selectivity of OPC-2009 for tracheal smooth muscle and its long duration of action suggest its potential usefulness for treatment of bronchial asthma. 8 The present results are also

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

    PubMed

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

    2017-03-01

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

  17. 3D pulmonary perfusion MRI and MR angiography of pulmonary embolism in pigs after a single injection of a blood pool MR contrast agent.

    PubMed

    Fink, Christian; Ley, Sebastian; Puderbach, Michael; Plathow, Christian; Bock, Michael; Kauczor, Hans-Ulrich

    2004-07-01

    The purpose of this study was to assess the feasibility of contrast-enhanced 3D perfusion MRI and MR angiography (MRA) of pulmonary embolism (PE) in pigs using a single injection of the blood pool contrast Gadomer. PE was induced in five domestic pigs by injection of autologous blood thrombi. Contrast-enhanced first-pass 3D perfusion MRI (TE/TR/FA: 1.0 ms/2.2 ms/40 degrees; voxel size: 1.3 x 2.5 x 4.0 mm3; TA: 1.8 s per data set) and high-resolution 3D MRA (TE/TR/FA: 1.4 ms/3.4 ms/40 degrees; voxel size: 0.8 x 1.0 x 1.6 mm3) was performed during and after a single injection of 0.1 mmol/kg body weight of Gadomer. Image data were compared to pre-embolism Gd-DTPA-enhanced MRI and post-embolism thin-section multislice CT (n = 2). SNR measurements were performed in the pulmonary arteries and lung. One animal died after induction of PE. In all other animals, perfusion MRI and MRA could be acquired after a single injection of Gadomer. At perfusion MRI, PE could be detected by typical wedge-shaped perfusion defects. While the visualization of central PE at MRA correlated well with the CT, peripheral PE were only visualized by CT. Gadomer achieved a higher peak SNR of the lungs compared to Gd-DTPA (21 +/- 8 vs. 13 +/- 3). Contrast-enhanced 3D perfusion MRI and MRA of PE can be combined using a single injection of the blood pool contrast agent Gadomer.

  18. Small-Scale Perfusion Bioreactor of Red Blood Cells for Dynamic Studies of Cellular Pathways: Proof-of-Concept.

    PubMed

    Prudent, Michel; Stauber, Frédéric; Rapin, Alexis; Hallen, Sonia; Pham, Nicole; Abonnenc, Mélanie; Marvin, Laure; Rochat, Bertrand; Tissot, Jean-Daniel; Lion, Niels

    2016-01-01

    To date, the development of bioreactors for the study of red blood cells (RBCs, daily transfused in the case of disease or hemorrhage) has focused on hematopoietic stem cells. Despite the fact that mature RBCs are enucleated and do not expand, they possess complex cellular and metabolic pathways, as well as post-translation modification signaling and gas-exchange regulation. In order to dynamically study the behavior of RBCs and their signaling pathways under various conditions, a small-scale perfusion bioreactor has been developed. The most advanced design developed here consists of a fluidized bed of 7.6 mL containing 3·10(9) cells and perfused at 8.5 μL/min. Mimicking RBC storage conditions in transfusion medicine, as a proof-of-concept, we investigated the ex vivo aging of RBCs under both aerobic and anaerobic conditions. Hence, RBCs stored in saline-adenine-glucose-mannitol (SAGM) were injected in parallel into two bioreactors and perfused with a modified SAGM solution over 14 days at room temperature under air or argon. The formation of a fluidized bed enabled easy sampling of the extracellular medium over the storage period used for the quantitation of glucose consumption and lactate production. Hemolysis and microvesiculation increased during aging and were reduced under anaerobic (argon) conditions, which is consistent with previously reported findings. Glucose and lactate levels showed expected trends, i.e., decreased and increased during the 2-week period, respectively; whereas extracellular glucose consumption was higher under aerobic conditions. Metabolomics showed depletion of glycolsis and pentose phosphate pathway metabolites, and an accumulation of purine metabolite end-products. This novel approach, which takes advantage of a fluidized bed of cells in comparison to traditional closed bags or tubes, does not require agitation and limit shear stress, and constantly segragates extracellular medium from RBCs. It thus gives access to several

  19. Small-Scale Perfusion Bioreactor of Red Blood Cells for Dynamic Studies of Cellular Pathways: Proof-of-Concept

    PubMed Central

    Prudent, Michel; Stauber, Frédéric; Rapin, Alexis; Hallen, Sonia; Pham, Nicole; Abonnenc, Mélanie; Marvin, Laure; Rochat, Bertrand; Tissot, Jean-Daniel; Lion, Niels

    2016-01-01

    To date, the development of bioreactors for the study of red blood cells (RBCs, daily transfused in the case of disease or hemorrhage) has focused on hematopoietic stem cells. Despite the fact that mature RBCs are enucleated and do not expand, they possess complex cellular and metabolic pathways, as well as post-translation modification signaling and gas-exchange regulation. In order to dynamically study the behavior of RBCs and their signaling pathways under various conditions, a small-scale perfusion bioreactor has been developed. The most advanced design developed here consists of a fluidized bed of 7.6 mL containing 3·109 cells and perfused at 8.5 μL/min. Mimicking RBC storage conditions in transfusion medicine, as a proof-of-concept, we investigated the ex vivo aging of RBCs under both aerobic and anaerobic conditions. Hence, RBCs stored in saline-adenine-glucose-mannitol (SAGM) were injected in parallel into two bioreactors and perfused with a modified SAGM solution over 14 days at room temperature under air or argon. The formation of a fluidized bed enabled easy sampling of the extracellular medium over the storage period used for the quantitation of glucose consumption and lactate production. Hemolysis and microvesiculation increased during aging and were reduced under anaerobic (argon) conditions, which is consistent with previously reported findings. Glucose and lactate levels showed expected trends, i.e., decreased and increased during the 2-week period, respectively; whereas extracellular glucose consumption was higher under aerobic conditions. Metabolomics showed depletion of glycolsis and pentose phosphate pathway metabolites, and an accumulation of purine metabolite end-products. This novel approach, which takes advantage of a fluidized bed of cells in comparison to traditional closed bags or tubes, does not require agitation and limit shear stress, and constantly segragates extracellular medium from RBCs. It thus gives access to several difficult

  20. Resting Cerebral Blood Flow Alterations in Chronic Traumatic Brain Injury: An Arterial Spin Labeling Perfusion fMRI Study

    PubMed Central

    Whyte, John; Patel, Sunil; Avants, Brian; Europa, Eduardo; Wang, Jiongjiong; Slattery, John; Gee, James C.; Coslett, H. Branch; Detre, John A.

    2010-01-01

    Abstract Non-invasive measurement of resting state cerebral blood flow (CBF) may reflect alterations of brain structure and function after traumatic brain injury (TBI). However, previous imaging studies of resting state brain in chronic TBI have been limited by several factors, including measurement in relative rather than absolute units, use of crude spatial registration methods, exclusion of subjects with substantial focal lesions, and exposure to ionizing radiation, which limits repeated assessments. This study aimed to overcome those obstacles by measuring absolute CBF with an arterial spin labeling perfusion fMRI technique, and using an image preprocessing protocol that is optimized for brains with mixed diffuse and focal injuries characteristic of moderate and severe TBI. Resting state CBF was quantified in 27 individuals with moderate to severe TBI in the chronic stage, and 22 demographically matched healthy controls. In addition to global CBF reductions in the TBI subjects, more prominent regional hypoperfusion was found in the posterior cingulate cortices, the thalami, and multiple locations in the frontal cortices. Diffuse injury, as assessed by tensor-based morphometry, was mainly associated with reduced CBF in the posterior cingulate cortices and the thalami, where the greatest volume losses were detected. Hypoperfusion in superior and middle frontal cortices, in contrast, was associated with focal lesions. These results suggest that structural lesions, both focal and diffuse, are the main contributors to the absolute CBF alterations seen in chronic TBI, and that CBF may serve as a tool to assess functioning neuronal volume. We also speculate that resting reductions in posterior cingulate perfusion may reflect alterations in the default-mode network, and may contribute to the attentional deficits common in TBI. PMID:20528163

  1. The impact of temperature and pump flow rate during selective cerebral perfusion on regional blood flow in piglets.

    PubMed

    Wang, Jian; Ginther, Richard M; Riegel, Matthew; Huang, Rong; Sharma, Mahesh S; Guleserian, Kristine J; Forbess, Joseph M

    2013-01-01

    Ideal temperature and flow rate for selective cerebral perfusion (SCP) are not known. We examined regional organ perfusion in a piglet SCP model. Three groups underwent SCP at 30 mL/kg/min at different temperatures (15°C, 25°C, and 32°C) and 4 groups remained at 25°C for SCP at different flow rates (10, 30, 50 and 75 mL/kg/min). Fluorescent microspheres were injected at 5 minutes of normothermic cardiopulmonary bypass (CPB), immediately before SCP, SCP 45 minutes, SCP 90 minutes, and 2 hours after CPB. Brain and lower body organs were collected to examine regional blood flow (RBF, mL/min/g). At 2 hours after CPB, RBF of the 32°C group was higher than that of the 15°C group (P < .05) at the caudate nucleus and hippocampus; RBF of the 32°C group was higher than that of the 25°C and 15°C groups (P < .05) at the neocortex. No significant difference in RBF was observed among any of the 25°C groups at different flow rates. Also, there was no significant difference between the RBF to the left and right sides of brain in either the temperature or flow rate groups. RBF did significantly increase with temperature in the liver and quadriceps during SCP (P < .05). At the kidney, RBF at SCP 90 minutes was significantly higher than that at SCP 45 minutes when all temperature groups were combined (P < .05). SCP at 32°C provides higher brain RBF 2 hours after CPB. Increasing SCP flow rate does not increase RBF significantly at 25°C. Higher temperature during SCP results in improved RBF to the liver and quadriceps. Copyright © 2013. Published by Mosby, Inc.

  2. Quantitative cerebral blood flow mapping and functional connectivity of postherpetic neuralgia pain: a perfusion fMRI study.

    PubMed

    Liu, Jing; Hao, Ying; Du, Minyi; Wang, Xiaoying; Zhang, Jue; Manor, Brad; Jiang, Xuexiang; Fang, Wenxue; Wang, Dongxin

    2013-01-01

    This article investigates the effects of postherpetic neuralgia (PHN) on resting-state brain activity utilizing arterial spin labeling (ASL) techniques. Features of static and dynamic cerebral blood flow (CBF) were analyzed to reflect the specific brain response to PHN pain. Eleven consecutive patients suffering from PHN and 11 age- and gender-matched control subjects underwent perfusion functional magnetic resonance imaging brain scanning during the resting state. Group comparison was conducted to detect the regions with significant changes of CBF in PHN patients. Then we chose those regions that were highly correlated with the self-reported pain intensity as "seeds" to calculate the functional connectivity of both groups. Absolute CBF values of these regions were also compared across PHN patients and control subjects. Significant increases in CBF of the patient group were observed in left striatum, right thalamus, left primary somatosensory cortex (S1), left insula, left amygdala, left primary somatomotor cortex, and left inferior parietal lobule. Significant decreases in CBF were mainly located in the frontal cortex. Regional CBF in the left caudate, left insula, left S1, and right thalamus was highly correlated with the pain intensity, and further comparison showed that the regional CBF in these regions is significantly higher in PHN groups. Functional connectivity results demonstrated that the reward circuitry involved in striatum, prefrontal cortex, amygdala, and parahippocampal gyrus and the circuitry among striatum, thalamus, and insula were highly correlated with each element in PHN patients. In addition, noninvasive brain perfusion imaging at rest may provide novel insights into the central mechanisms underlying PHN pain.

  3. Resting cerebral blood flow alterations in chronic traumatic brain injury: an arterial spin labeling perfusion FMRI study.

    PubMed

    Kim, Junghoon; Whyte, John; Patel, Sunil; Avants, Brian; Europa, Eduardo; Wang, Jiongjiong; Slattery, John; Gee, James C; Coslett, H Branch; Detre, John A

    2010-08-01

    Non-invasive measurement of resting state cerebral blood flow (CBF) may reflect alterations of brain structure and function after traumatic brain injury (TBI). However, previous imaging studies of resting state brain in chronic TBI have been limited by several factors, including measurement in relative rather than absolute units, use of crude spatial registration methods, exclusion of subjects with substantial focal lesions, and exposure to ionizing radiation, which limits repeated assessments. This study aimed to overcome those obstacles by measuring absolute CBF with an arterial spin labeling perfusion fMRI technique, and using an image preprocessing protocol that is optimized for brains with mixed diffuse and focal injuries characteristic of moderate and severe TBI. Resting state CBF was quantified in 27 individuals with moderate to severe TBI in the chronic stage, and 22 demographically matched healthy controls. In addition to global CBF reductions in the TBI subjects, more prominent regional hypoperfusion was found in the posterior cingulate cortices, the thalami, and multiple locations in the frontal cortices. Diffuse injury, as assessed by tensor-based morphometry, was mainly associated with reduced CBF in the posterior cingulate cortices and the thalami, where the greatest volume losses were detected. Hypoperfusion in superior and middle frontal cortices, in contrast, was associated with focal lesions. These results suggest that structural lesions, both focal and diffuse, are the main contributors to the absolute CBF alterations seen in chronic TBI, and that CBF may serve as a tool to assess functioning neuronal volume. We also speculate that resting reductions in posterior cingulate perfusion may reflect alterations in the default-mode network, and may contribute to the attentional deficits common in TBI.

  4. Near-infrared spectroscopy and indocyanine green derived blood flow index for noninvasive measurement of muscle perfusion during exercise.

    PubMed

    Habazettl, Helmut; Athanasopoulos, Dimitris; Kuebler, Wolfgang M; Wagner, Harrieth; Roussos, Charis; Wagner, Peter D; Ungruhe, Juergen; Zakynthinos, Spyros; Vogiatzis, Ioannis

    2010-04-01

    Near-infrared spectroscopy (NIRS) with the tracer indocyanine green (ICG) may be used for measuring muscle blood flow (MBF) during exercise, if arterial ICG concentration is measured simultaneously. Although pulse dye densitometry allows for noninvasive measurement of arterial dye concentration, this technique is sensitive to motion and may not be applicable during exercise. The aim of this study was to evaluate a noninvasive blood flow index (BFI), which is derived solely from the muscle ICG concentration curve. In 10 male cyclists 5 mg ICG were injected into an antecubital vein at rest and during cycling at 30, 60, 70, 80, 90, and 100% of previously determined maximal work load. Simultaneously blood was withdrawn through a photodensitometer at 20 ml/min from the radial artery to measure arterial ICG concentration. To measure muscle tissue ICG concentrations, two sets of NIRS optodes were positioned on the skin, one over the left seventh intercostal space and the other over the left vastus lateralis muscle. MBF was calculated from the arterial and muscle concentration data according to Fick's principle. BFI was calculated solely from the muscle concentration curve as ICG concentration difference divided by rise time between 10 and 90% of peak. During exercise mean BFI values changed similarly to MBF in both intercostal and quadriceps muscles and showed excellent correlations with MBF: r = 0.98 and 0.96, respectively. Individual data showed some scattering among BFI and MBF values but still reasonable correlations of BFI with MBF: r = 0.73 and 0.72 for intercostal and quadriceps muscles, respectively. Interobserver variability, as analyzed by Bland-Altman plots, was considerably less for BFI than MBF. These data suggest that BFI can be used for measuring changes in muscle perfusion from rest to maximal exercise. Although absolute blood flow cannot be determined, BFI has the advantages of being essentially noninvasive and having low interobserver variability.

  5. Multiparametric assessment of vascular function in peripheral artery disease: dynamic measurement of skeletal muscle perfusion, blood-oxygen-level dependent signal, and venous oxygen saturation.

    PubMed

    Englund, Erin K; Langham, Michael C; Ratcliffe, Sarah J; Fanning, Molly J; Wehrli, Felix W; Mohler, Emile R; Floyd, Thomas F

    2015-04-01

    Endothelial dysfunction present in patients with peripheral artery disease may be better understood by measuring the temporal dynamics of blood flow and oxygen saturation during reactive hyperemia than by conventional static measurements. Perfusion, Intravascular Venous Oxygen saturation, and T2* (PIVOT), a recently developed MRI technique, was used to measure the response to an ischemia-reperfusion paradigm in 96 patients with peripheral artery disease of varying severity and 10 healthy controls. Perfusion, venous oxygen saturation SvO2, and T2* were each quantified in the calf at 2-s temporal resolution, yielding a dynamic time course for each variable. Compared with healthy controls, patients had a blunted and delayed hyperemic response. Moreover, patients with lower ankle-brachial index had (1) a more delayed reactive hyperemia response time, manifesting as an increase in time to peak perfusion in the gastrocnemius, soleus, and peroneus muscles, and in the anterior compartment, (2) an increase in the time to peak T2* measured in the soleus muscle, and (3) a prolongation of the posterior tibial vein SvO2 washout time. Intrasession and intersession repeatability were also assessed. Results indicated that time to peak perfusion and time to peak T2* were the most reliable extracted time course metrics. Perfusion, dynamic SvO2, and T2* response times after induced ischemia are highly correlated with peripheral artery disease severity. Combined imaging of peripheral microvascular blood flow and dynamics of oxygen saturation with Perfusion, intravascular SvO2, and T2* may be a useful tool to investigate the pathophysiology of peripheral artery disease. © 2015 American Heart Association, Inc.

  6. More accurate quantification of pulmonary blood flow by magnetic resonance imaging than by lung perfusion scintigraphy in patients with fontan circulation.

    PubMed

    Fratz, Sohrab; Hess, John; Schwaiger, Markus; Martinoff, Stefan; Stern, Heiko C

    2002-09-17

    Quantitative evaluation of pulmonary perfusion using lung perfusion scintigraphy in patients with atriopulmonary anastomosis (APA) or total cavopulmonary connection (TCPC) or partial cavopulmonary connection (PCPC) is difficult because of preferential draining of the venae cavae to one lung. Scintigraphy is the gold standard. Phase-velocity MRI (PV-MRI) is a new technique for determining pulmonary perfusion. The aim of this study was therefore to determine whether PV-MRI is more accurate than scintigraphy for quantitative evaluation of pulmonary perfusion ratios in patients with APA, TCPC, or PCPC. We studied 15 patients with APA, TCPC, or PCPC (16+/-7 years old, 4 female). Twelve patients (15+/-8 years old, 3 female) with a single pulmonary blood source supplied by a subpulmonary ventricle, ensuring complete mixing of the radioactive tracer before entering the pulmonary circulation, served as controls. Pulmonary scintigraphy and PV-MRI were performed in all patients. Bland-Altman analysis showed a clinically unacceptable difference of 7.1% right pulmonary blood flow (27.2% upper and -13.0% lower limit of agreement) between the two methods in the study group. The two methods agreed excellently in the control group (difference, 1.6%; 4.0% upper and -7.2% lower limit of agreement), showing that the bad agreement in the study group was caused by the problems encountered using pulmonary scintigraphy in patients with APA, TCPC, or PCPC. Because of preferential caval flow into either lung, PV-MRI is more accurate for evaluating pulmonary perfusion ratios than lung perfusion scintigraphy in patients with Fontan-like circulation.

  7. Modeling and optimization of Look-Locker spin labeling for measuring perfusion and transit time changes in activation studies taking into account arterial blood volume.

    PubMed

    Francis, S T; Bowtell, R; Gowland, P A

    2008-02-01

    This work describes a new compartmental model with step-wise temporal analysis for a Look-Locker (LL)-flow-sensitive alternating inversion-recovery (FAIR) sequence, which combines the FAIR arterial spin labeling (ASL) scheme with a LL echo planar imaging (EPI) measurement, using a multireadout EPI sequence for simultaneous perfusion and T*(2) measurements. The new model highlights the importance of accounting for the transit time of blood through the arteriolar compartment, delta, in the quantification of perfusion. The signal expected is calculated in a step-wise manner to avoid discontinuities between different compartments. The optimal LL-FAIR pulse sequence timings for the measurement of perfusion with high signal-to-noise ratio (SNR), and high temporal resolution at 1.5, 3, and 7T are presented. LL-FAIR is shown to provide better SNR per unit time compared to standard FAIR. The sequence has been used experimentally for simultaneous monitoring of perfusion, transit time, and T*(2) changes in response to a visual stimulus in four subjects. It was found that perfusion increased by 83 +/- 4% on brain activation from a resting state value of 94 +/- 13 ml/100 g/min, while T*(2) increased by 3.5 +/- 0.5%. (c) 2008 Wiley-Liss, Inc.

  8. Response of Blood Perfusion at ST 36 Acupoint after Drinking Cold Glucose or Saline Injection.

    PubMed

    Wang, Guangjun; Jia, Shuyong; Li, Hongyan; Wang, Ze; Tian, Yuying; Zhang, Weibo

    2017-01-01

    Skin blood flux (SkBF) changes caused by drinking cold water are generally associated with vagal tone and osmotic factors in digestive system. According to acupuncture theory, change of SkBF at ST 36 might reflect the functional changes of digestive system. The aim of this study is to analyze the changes of SkBF after drinking 3°C 0.9% saline or 5% glucose injection by monitor blood flux at bilateral ST 36. The results indicated that, after drinking different cold water, the change ratio of SkBF at right side ST 36 has been different. Because all solutions have the same temperature (3°C) and both saline and glucose solution have the same osmolality, suggesting that the SkBF changes resulting from drinking cold water are not regulated just by the vagal tone and osmolality, there must have been other factors. These results have not been consistent with the frequency domain results of heart rate variability (HRV) analysis. Coherence analysis of blood flux signals at bilateral ST 36 indicated that there have been different coherence-frequency curves among different groups in special frequency bands, which suggested that coherence analysis might provide a potential tool to evaluate different status.

  9. Improving cerebral blood flow quantification for arterial spin labeled perfusion MRI by removing residual motion artifacts and global signal fluctuations.

    PubMed

    Wang, Ze

    2012-12-01

    Denoising is critical to improving the quality and stability of cerebral blood flow (CBF) quantification in arterial spin labeled (ASL) perfusion magnetic resonance imaging (MRI) due to the intrinsic low signal-to-noise-ratio (SNR) of ASL data. Previous studies have been focused on reducing the spatial or temporal noise using standard filtering techniques, and less attention has been paid to two global nuisance effects, the residual motion artifacts and the global signal fluctuations. Since both nuisances affect the whole brain, removing them in advance should enhance the CBF quantification quality for ASL MRI. The purpose of this paper was to assess this potential benefit. Three methods were proposed to suppress each or both of the two global nuisances. Their performances for CBF quantification were validated using ASL data acquired from 13 subjects. Evaluation results showed that covarying out both global nuisances significantly improved temporal SNR and test-retest stability of CBF measurement. Although the concept of removing both nuisances is not technically novel per se, this paper clearly showed the benefits for ASL CBF quantification. Dissemination of the proposed methods in a free ASL data processing toolbox should be of interest to a broad range of ASL users.

  10. Perfusion computed tomography of intracranial meningiomas: In vivo correlation of cerebral blood volume and vascular permeability.

    PubMed

    Granata, Francesca; Morabito, Rosa; Alafaci, Concetta; Barresi, Valeria; Tomasello, Francesco; Vinci, Sergio; Mormina, Enricomaria; Calamuneri, Alessandro; Grasso, Giovanni; Salpietro, Francesco Maria; Longo, Marcello

    2015-06-01

    A noninvasive method to predict the grade of a meningioma would be desirable since it would anticipate information about tumour nature, recurrence and improve tumour management and outcomes. The aim of the present study was to assess the ability of perfusion computed tomography (PCT) technique in predicting the meningioma grade before surgery. Data from PCT, such as cerebral blood volume (CBV) and permeability surface (PS), were correlated with immunohistolopathological information. Twenty-three patients with a diagnosis of intracranial meningioma underwent PCT for pre-surgical evaluation of CBV and PS. During surgery, samples from the centre and periphery of the tumour were obtained. Two correspondent regions of interest (ROIs) were drawn on CBV and PS maps. Central and peripheral CBV and PS mean values were calculated. PCT parameters were correlated to CD-34 and endoglin. There was a positive correlation between PS and CD-34. No correlation was found between PS values and endoglin, CBV values and CD-34 and endoglin values. Our findings suggest that PCT may support conventional morphological imaging in predicting meningioma grading before surgery. © The Author(s) 2015.

  11. Increased blood-brain barrier permeability on perfusion computed tomography predicts hemorrhagic transformation in acute ischemic stroke.

    PubMed

    Ozkul-Wermester, Ozlem; Guegan-Massardier, Evelyne; Triquenot, Aude; Borden, Alaina; Perot, Guillaume; Gérardin, Emmanuel

    2014-01-01

    Perfusion computed tomography (CT) is capable of measuring the permeability surface product (PS). PS reflects the permeability of the blood-brain barrier, involved in the pathophysiology of hemorrhagic transformation (HT) of ischemic stroke. The aim of our study was to determine if an increased PS can predict HT. A total of 86 patients with ischemic stroke were included. They underwent multimodality CT, including the measurement of PS. We compared the clinical and radiological characteristics of patients who developed HT to those who did not, using univariate analysis. Multivariate regression analyses were then used to determine HT predictors. HT was observed in 27 patients (31%). Infarct PS was significantly associated with HT (p = 0.047), as were atrial fibrillation (p = 0.03), admission National Institute of Health Stroke Scale score (p = 0.02), infarct volume (p = 0.0004), presence of large-vessel occlusion (p = 0.0005) and a poorer collateral status (p = 0.003). Using logistic regression modeling, an infarct PS >0.84 ml/100 g/min was an independent predictor of HT (OR 28, 95% CI 1.75-452.98; p = 0.02). Other independent predictors of HT were infarct volume and a history of atrial fibrillation. Our findings suggest that infarct PS can be a predictor of HT and may help clinicians to improve patient care around thrombolysis decisions in the acute phase of ischemic stroke. © 2014 S. Karger AG, Basel.

  12. Additive global cerebral blood flow normalization in arterial spin labeling perfusion imaging.

    PubMed

    Stewart, Stephanie B; Koller, Jonathan M; Campbell, Meghan C; Perlmutter, Joel S; Black, Kevin J

    2015-01-01

    To determine how different methods of normalizing for global cerebral blood flow (gCBF) affect image quality and sensitivity to cortical activation, pulsed arterial spin labeling (pASL) scans obtained during a visual task were normalized by either additive or multiplicative normalization of modal gCBF. Normalization by either method increased the statistical significance of cortical activation by a visual stimulus. However, image quality was superior with additive normalization, whether judged by intensity histograms or by reduced variability within gray and white matter.

  13. Assessment of cerebral blood perfusion reserve with acetazolamide using 3D spiral ASL MRI: Preliminary experience in pediatric patients.

    PubMed

    Hu, Houchun H; Li, Zhiqiang; Pokorney, Amber L; Chia, Jonathan M; Stefani, Niccolo; Pipe, James G; Miller, Jeffrey H

    2017-01-01

    To demonstrate the clinical feasibility of a new non-Cartesian cylindrically-distributed spiral 3D pseudo-continuous arterial spin labeling (pCASL) magnetic resonance imaging (MRI) pulse sequence in pediatric patients in quantifying cerebral blood flow (CBF) response to an acetazolamide (ACZ) vasodilator challenge. MRI exams were performed on two 3 Tesla Philips Ingenia systems using 32 channel head coil arrays. After local institutional review board approval, the 3D spiral-based pCASL technique was added to a standard brain MRI exam and evaluated in 13 pediatric patients (average age: 11.7±6.4years, range: 1.4-22.2years). All patients were administered ACZ for clinically indicated reasons. Quantitative whole-brain CBF measurements were computed pre- and post-ACZ to assess cerebrovascular reserve. 3D spiral pCASL data were successfully reconstructed in all 13 cases. In 11 patients, CBF increased 2.8% to 93.2% after administration of ACZ. In the two remaining patients, CBF decreased by 2.4 to 6.0% after ACZ. The group average change in CBF due to ACZ was approximately 25.0% and individual changes were statistically significant (p<0.01) in all patients using a paired t-test analysis. CBF perfusion data were diagnostically useful in supporting conventional MR angiography and clinical findings. 3D cylindrically-distributed spiral pCASL MRI provides a robust approach to assess cerebral blood flow and reserve in pediatric patients. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. The influence of local pressure on evaluation parameters of skin blood perfusion and fluorescence

    NASA Astrophysics Data System (ADS)

    Zherebtsov, E. A.; Kandurova, K. Y.; Seryogina, E. S.; Kozlov, I. O.; Dremin, V. V.; Zherebtsova, A. I.; Dunaev, A. V.; Meglinski, I.

    2017-03-01

    This article presents the results of the study of the pressure applied on optical diagnostic probes as a significant factor affecting the results of measurements. During stepwise increasing and decreasing of local pressure on skin we conducted measurements using the methods of laser Doppler flowmetry and fluorescence spectroscopy. It was found out that pressure on optical probe has sufficient impact on skin microcirculation to affect registered fluorescence intensity. Data obtained in this study are of interest for design and development of diagnostic technologies for wearable devices. This data will also inform further investigation into issues of compensation of blood absorption influence on fluorescence spectrum, allowing increased accuracy and reproducibility of measurements by fluorescence spectroscopy methods in optical diagnosis.

  15. Dynamic markers based on blood perfusion fluctuations for selecting skin melanocytic lesions for biopsy

    NASA Astrophysics Data System (ADS)

    Lancaster, Gemma; Stefanovska, Aneta; Pesce, Margherita; Marco Vezzoni, Gian; Loggini, Barbara; Pingitore, Raffaele; Ghiara, Fabrizio; Barachini, Paolo; Cervadoro, Gregorio; Romanelli, Marco; Rossi, Marco

    2015-08-01

    Skin malignant melanoma is a highly angiogenic cancer, necessitating early diagnosis for positive prognosis. The current diagnostic standard of biopsy and histological examination inevitably leads to many unnecessary invasive excisions. Here, we propose a non-invasive method of identification of melanoma based on blood flow dynamics. We consider a wide frequency range from 0.005-2 Hz associated with both local vascular regulation and effects of cardiac pulsation. Combining uniquely the power of oscillations associated with individual physiological processes we obtain a marker which distinguishes between melanoma and atypical nevi with sensitivity of 100% and specificity of 90.9%. The method reveals valuable functional information about the melanoma microenvironment. It also provides the means for simple, accurate, in vivo distinction between malignant melanoma and atypical nevi, and may lead to a substantial reduction in the number of biopsies currently undertaken.

  16. Lithium microdialysis and its use for monitoring of stomach and colon submucosal blood perfusion--a pilot study using ischemic preconditioning in rats.

    PubMed

    Cibicek, Norbert; Micuda, Stanislav; Chládek, Jaroslav; Zivný, Pavel; Zadák, Zdenek; Cermáková, Eva; Palicka, Vladimír

    2006-01-01

    During shock, exposure of gut to ischemia determines patient's survival. Ischemic preconditioning (ISP) elevates nitric oxide and blood perfusion, whereby it protects organs against subsequent severe ischemia/reperfusion. Using appropriate flow marker, microdialysis may serve to monitor interstitial microcirculation. Hence, our aim was to test the reliability of lithium as a flow marker (lithium microdialysis, LM) on an ISP model. Rats were divided into three groups. Two (ischemic and preconditioned) groups underwent 30 min celiac artery occlusion (CAO) with 2.5 h reperfusion. 25 min before CAO, the latter experienced 5 min ischemia. Sham-operated animals served as controls. LM in stomach and colon submucosa, serum nitric oxide, hepatic and pancreatic enzymes were measured. In stomach, LM indicated a decrease in blood perfusion evoked by CAO (p < 0.01) in both experimental groups. During reperfusion, the ischemic animals showed a restoration of microcirculation, unlike the preconditioned ones, whose blood perfusion failed to regenerate (p < 0.001). For any group, LM showed no microcirculation modification in colon. Serum analytes remained unchanged. We conclude that LM appears to be a potentially suitable indicator of gastrointestinal interstitial microcirculation. However, we failed to demonstrate any beneficial effect of ISP on pancreas, systemic nitric oxide and local/remote microcirculation within studied organs.

  17. A postoperative analysis of perfusion dynamics in deep inferior epigastric perforator flap breast reconstruction: a noninvasive quantitative measurement of flap oxygen saturation and blood flow.

    PubMed

    Rahmanian-Schwarz, Afshin; Rothenberger, Jens; Amr, Amro; Jaminet, Patrick; Schaller, Hans-Eberhard

    2012-11-01

    The blood supply of microvascular free flaps is rated as very critical, particularly in the first postoperative days. Only a timely recognition of a complication and its treatment can ensure the survival of the flap. To quantify the postoperative perfusion dynamics, we measured the oxygen supply and blood flow of the deep inferior epigastric perforator (DIEP) flaps. A total of 23 patients undergoing DIEP flap breast reconstruction were involved in this study. Noninvasive measurements were performed with the O2C-device, which combines the determination of hemoglobin oxygenation and blood flow using white light and laser light. The first measurement was performed immediately after the flap anastomosis. Further measurements were carried out on the first, third, fifth, and seventh postoperative days. The preoperative value represents our baseline. With the exception of the third day, all postoperative measurements were above the baseline. On the third postoperative day, there was a decrease in the cutaneous oxygen saturation of 22% and a decrease in blood flow of 18% on average, regardless of the individual fluctuations of patient's blood pressure. The postoperative perfusion characteristics of the DIEP flap showed a critical drop in the cutaneous oxygen supply and blood flow on the third postoperative day. This represents a potential risk and should be considered in the postoperative management of the DIEP flap.

  18. Assessment of a protocol for routine simultaneous myocardial blood flow measurement and standard myocardial perfusion imaging with rubidium-82 on a high count rate positron emission tomography system.

    PubMed

    Tout, Deborah; Tonge, Christine M; Muthu, Sivakumar; Arumugam, Parthiban

    2012-11-01

    High count rate positron emission tomography (PET) systems offer the potential for accurate myocardial blood flow (MBF) quantification during first-pass dynamic imaging in conjunction with standard rubidium-82 (Rb-82) PET myocardial perfusion imaging (MPI). We investigate the feasibility of this using a Siemens Biograph mCT. Current routine clinical PET MPI is performed with 1480 MBq (40 mCi) Rb-82. Dynamic first-pass images from 217 consecutive patients were reviewed for evidence of detector saturation, indicating that count rate limits had been exceeded. Phantom acquisitions in the presence of high count rates were performed to assess the effect of detector saturation on quantitative accuracy. Accurate MBF quantification and perfusion imaging using current protocols was successful in 85% of clinical cases. Detector block saturation was observed in 15% of cases, and phantom acquisitions indicate that saturation may have an adverse effect on quantitative accuracy. Visualization of transit or pooling of Rb-82 in the vessels in the axilla was the most consistent feature when saturation occurred. Reduction of administered activity to 1110 MBq (30 mCi) and subsequent evaluation of 159 patients ensured successful MBF quantification while maintaining good diagnostic quality perfusion imaging in 99% of cases. MBF quantification and good-quality standard perfusion imaging can be performed on a high count rate PET system using a single-acquisition protocol. The administered activity requires optimization and we recommend 1110 MBq for PET MPI with a Biograph mCT.

  19. Psychiatric profiles and patterns of cerebral blood flow in focal epilepsy: interactions between depression, obsessionality, and perfusion related to the laterality of the epilepsy.

    PubMed Central

    Schmitz, E B; Moriarty, J; Costa, D C; Ring, H A; Ell, P J; Trimble, M R

    1997-01-01

    OBJECTIVES: In a study of patients with focal epilepsy the hypothesis was explored that different measurements of psychopathology are related to specific distributions of cerebral perfusion. METHODS: Forty patients had SPECT performed with (99m)Tc-HMPAO. In addition, patients received a psychiatric evaluation with the following psychiatric questionnaires: the Beck depression inventory, the Leyton obsessionality inventory, the Bear-Fedio questionnaire, and the social stress and support interview. Patients were analysed in two groups according to the laterality of the epilepsy. Nine patients were excluded based on poor quality scans (n = 1), unlateralised epilepsy (n = 4), and left or ambidextrous handedness (n = 4). RESULTS: There were no overall differences between the left and right epilepsy groups on measures of psychopathology. Associations were found between scores on some of the rating scales and regional cerebral blood flow. Specifically, for patients with left sided epilepsy, higher scores on the Beck depression inventory were associated with lower contralateral temporal and bilateral frontal perfusion, and higher occipital perfusion. For patients with right sided epilepsy higher scores on the Leyton obsessionality inventory were associated with increased perfusion in ipsilateral temporal, thalamic, and basal ganglia regions and bilateral frontal regions. CONCLUSION: The results do not support the notion that lateralised epileptogenic lesions are associated with different levels of depression, obsessionality, or personality traits. They support the view that certain psychopathological symptom patterns are related to specific regional dysfunctions depending on the laterality of a hemispheric lesion. PMID:9153601

  20. Laser Doppler perfusion imaging of skin blood flow using red and near-infrared sources.

    PubMed

    Abbot, N C; Ferrell, W R; Lockhart, J C; Lowe, J G

    1996-12-01

    At present, scanning laser Doppler imaging uses a 633-nm helium-neon laser (RED) as the only light source, but this restricts its ability to measure blood flow (i) at darkly pigmented skin and (ii) from deeper or subdermal structures. Because near-infrared (NIR) light is known to penetrate deeper into tissue and to be less absorbed than RED, two imagers were adapted to include a NIR laser diode source (one of 830 nm for UK studies; one of 780 nm for leprosy field trials) in parallel with the existing RED source. In human hands representing a range of skin pigmentations, RED scans were unobtainable at the darkest areas of skin, but intact NIR scans could be collected in all cases. In experiments at the rat knee and the dorsal human hand, NIR and RED values were similar on normal skin. Over underlying vessels, however, NIR values greatly exceeded RED values, an effect abolished by occlusion. Similarly, in patients with leprosy and in healthy controls in Spain, fingerpulp NIR values exceeded RED values to the greatest degree when thermoregulatory flow was highest, i.e., when the deeper-lying arteriovenous anastomoses were open. Over areas of experimental inflammation, NIR gave higher values and also exhibited a greater degree of spatial heterogeneity than RED. We conclude that some current limitations of laser Doppler imaging technology can be overcome by the use of NIR laser diode sources.

  1. Validation of Perfusion Quantification with 3D Gradient Echo Dynamic Contrast-Enhanced Magnetic Resonance Imaging Using a Blood Pool Contrast Agent in Skeletal Swine Muscle.

    PubMed

    Hindel, Stefan; Sauerbrey, Anika; Maaß, Marc; Maderwald, Stefan; Schlamann, Marc; Lüdemann, Lutz

    2015-01-01

    The purpose of our study was to validate perfusion quantification in a low-perfused tissue by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with shared k-space sampling using a blood pool contrast agent. Perfusion measurements were performed in a total of seven female pigs. An ultrasonic Doppler probe was attached to the right femoral artery to determine total flow in the hind leg musculature. The femoral artery was catheterized for continuous local administration of adenosine to increase blood flow up to four times the baseline level. Three different stable perfusion levels were induced. The MR protocol included a 3D gradient-echo sequence with a temporal resolution of approximately 1.5 seconds. Before each dynamic sequence, static MR images were acquired with flip angles of 5°, 10°, 20°, and 30°. Both static and dynamic images were used to generate relaxation rate and baseline magnetization maps with a flip angle method. 0.1 mL/kg body weight of blood pool contrast medium was injected via a central venous catheter at a flow rate of 5 mL/s. The right hind leg was segmented in 3D into medial, cranial, lateral, and pelvic thigh muscles, lower leg, bones, skin, and fat. The arterial input function (AIF) was measured in the aorta. Perfusion of the different anatomic regions was calculated using a one- and a two-compartment model with delay- and dispersion-corrected AIFs. The F-test for model comparison was used to decide whether to use the results of the one- or two-compartment model fit. Total flow was calculated by integrating volume-weighted perfusion values over the whole measured region. The resulting values of delay, dispersion, blood volume, mean transit time, and flow were all in physiologically and physically reasonable ranges. In 107 of 160 ROIs, the blood signal was separated, using a two-compartment model, into a capillary and an arteriolar signal contribution, decided by the F-test. Overall flow in hind leg muscles, as measured by the

  2. Validation of Perfusion Quantification with 3D Gradient Echo Dynamic Contrast-Enhanced Magnetic Resonance Imaging Using a Blood Pool Contrast Agent in Skeletal Swine Muscle

    PubMed Central

    Hindel, Stefan; Sauerbrey, Anika; Maaß, Marc; Maderwald, Stefan; Schlamann, Marc; Lüdemann, Lutz

    2015-01-01

    The purpose of our study was to validate perfusion quantification in a low-perfused tissue by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with shared k-space sampling using a blood pool contrast agent. Perfusion measurements were performed in a total of seven female pigs. An ultrasonic Doppler probe was attached to the right femoral artery to determine total flow in the hind leg musculature. The femoral artery was catheterized for continuous local administration of adenosine to increase blood flow up to four times the baseline level. Three different stable perfusion levels were induced. The MR protocol included a 3D gradient-echo sequence with a temporal resolution of approximately 1.5 seconds. Before each dynamic sequence, static MR images were acquired with flip angles of 5°, 10°, 20°, and 30°. Both static and dynamic images were used to generate relaxation rate and baseline magnetization maps with a flip angle method. 0.1 mL/kg body weight of blood pool contrast medium was injected via a central venous catheter at a flow rate of 5 mL/s. The right hind leg was segmented in 3D into medial, cranial, lateral, and pelvic thigh muscles, lower leg, bones, skin, and fat. The arterial input function (AIF) was measured in the aorta. Perfusion of the different anatomic regions was calculated using a one- and a two-compartment model with delay- and dispersion-corrected AIFs. The F-test for model comparison was used to decide whether to use the results of the one- or two-compartment model fit. Total flow was calculated by integrating volume-weighted perfusion values over the whole measured region. The resulting values of delay, dispersion, blood volume, mean transit time, and flow were all in physiologically and physically reasonable ranges. In 107 of 160 ROIs, the blood signal was separated, using a two-compartment model, into a capillary and an arteriolar signal contribution, decided by the F-test. Overall flow in hind leg muscles, as measured by the

  3. Melatonin inhibits alcohol-induced increases in duodenal mucosal permeability in rats in vivo.

    PubMed

    Sommansson, Anna; Saudi, Wan Salman Wan; Nylander, Olof; Sjöblom, Markus

    2013-07-01

    Increased intestinal permeability is often associated with epithelial inflammation, leaky gut, or other pathological conditions in the gastrointestinal tract. We recently found that melatonin decreases basal duodenal mucosal permeability, suggesting a mucosal protective mode of action of this agent. The aim of the present study was to elucidate the effects of melatonin on ethanol-, wine-, and HCl-induced changes of duodenal mucosal paracellular permeability and motility. Rats were anesthetized with thiobarbiturate and a ~30-mm segment of the proximal duodenum was perfused in situ. Effects on duodenal mucosal paracellular permeability, assessed by measuring the blood-to-lumen clearance of ⁵¹Cr-EDTA, motility, and morphology, were investigated. Perfusing the duodenal segment with ethanol (10 or 15% alcohol by volume), red wine, or HCl (25-100 mM) induced concentration-dependent increases in paracellular permeability. Luminal ethanol and wine increased, whereas HCl transiently decreased duodenal motility. Administration of melatonin significantly reduced ethanol- and wine-induced increases in permeability by a mechanism abolished by the nicotinic receptor antagonists hexamethonium (iv) or mecamylamine (luminally). Signs of mucosal injury (edema and beginning of desquamation of the epithelium) in response to ethanol exposure were seen only in a few villi, an effect that was histologically not changed by melatonin. Melatonin did not affect HCl-induced increases in mucosal permeability or decreases in motility. Our results show that melatonin reduces ethanol- and wine-induced increases in duodenal paracellular permeability partly via an enteric inhibitory nicotinic-receptor dependent neural pathway. In addition, melatonin inhibits ethanol-induced increases in duodenal motor activity. These results suggest that melatonin may serve important gastrointestinal barrier functions.

  4. Short-term effects of brimonidine/timolol and dorzolamide/timolol on ocular perfusion pressure and blood flow in glaucoma.

    PubMed

    Siesky, Brent; Harris, Alon; Ehrlich, Rita; Cantor, Louis; Shoja, Mohammadali M; Rusia, Deepam; Hollander, David A; Abrams, Leslie; Williams, Julia M; Shoshani, Yochai

    2012-01-01

    To examine the comparative short-term effects of brimonidine/timolol and dorzolamide/timolol on ocular perfusion pressure and retrobulbar blood flow in patients with primary open angle glaucoma (OAG). In a prospective, randomized, double-blind, crossover study, intraocular pressure (IOP), blood pressure (BP), ocular perfusion pressure (OPP), and retrobulbar hemodynamics were assessed in 15 patients with OAG (mean age 68.1 years, eight women) with well controlled IOP. IOP was measured by Goldman applanation tonometery and color Doppler imaging was utilized to assess the retrobulbar blood vessels before and 1 month after treatment with topical brimonidine/timolol and dorzolamide/timolol. Statistical analysis was performed by Friedman two-way analysis of variance by ranks and post-hoc Wilcoxon signed rank test for multiple comparisons with Holm's sequential Bonferroni procedure. P values <0.05 were considered statistically significant. The Friedman test and subsequent post-hoc analysis indicated that IOP, BP, OPP, and retrobulbar blood flow velocities did not significantly differ between brimonidine/timolol and dorzolamide/timolol after 1-month treatment administration in patients with OAG and well controlled IOP. In this cohort of patients with OAG, short-term treatment with brimonidine/timolol and dorzolamide/timolol results in similar effects on OPP and retrobulbar blood flow velocities.

  5. Simultaneous myocardial strain and dark-blood perfusion imaging using a displacement-encoded MRI pulse sequence.

    PubMed

    Le, Yuan; Stein, Ashley; Berry, Colin; Kellman, Peter; Bennett, Eric E; Taylor, Joni; Lucas, Katherine; Kopace, Rael; Chefd'Hotel, Christophe; Lorenz, Christine H; Croisille, Pierre; Wen, Han

    2010-09-01

    The purpose of this study is to develop and evaluate a displacement-encoded pulse sequence for simultaneous perfusion and strain imaging. Displacement-encoded images in two to three myocardial slices were repeatedly acquired using a single-shot pulse sequence for 3 to 4 min, which covers a bolus infusion of Gadolinium contrast. The magnitudes of the images were T(1) weighted and provided quantitative measures of perfusion, while the phase maps yielded strain measurements. In an acute coronary occlusion swine protocol (n = 9), segmental perfusion measurements were validated against microsphere reference standard with a linear regression (slope 0.986, R(2) = 0.765, Bland-Altman standard deviation = 0.15 mL/min/g). In a group of ST-elevation myocardial infarction patients (n = 11), the scan success rate was 76%. Short-term contrast washout rate and perfusion are highly correlated (R(2) = 0.72), and the pixelwise relationship between circumferential strain and perfusion was better described with a sigmoidal Hill curve than linear functions. This study demonstrates the feasibility of measuring strain and perfusion from a single set of images.

  6. Simultaneous Myocardial Strain and Dark-Blood Perfusion Imaging Using a Displacement-Encoded MRI Pulse Sequence

    PubMed Central

    Le, Yuan; Stein, Ashley; Berry, Colin; Kellman, Peter; Bennett, Eric E.; Taylor, Joni; Lucas, Katherine; Kopace, Rael; Chefd’Hotel, Christophe; Lorenz, Christine H.; Croisille, Pierre; Wen, Han

    2010-01-01

    The purpose of this study is to develop and evaluate a displacement-encoded pulse sequence for simultaneous perfusion and strain imaging. Displacement-encoded images in 2–3 myocardial slices were repeatedly acquired using a single shot pulse sequence for 3 to 4 minutes, which covers a bolus infusion of Gd. The magnitudes of the images were T1 weighted and provided quantitative measures of perfusion, while the phase maps yielded strain measurements. In an acute coronary occlusion swine protocol (n=9), segmental perfusion measurements were validated against microsphere reference standard with a linear regression (slope 0.986, R2 = 0.765, Bland-Altman standard deviation = 0.15 ml/min/g). In a group of ST-elevation myocardial infarction(STEMI) patients (n=11), the scan success rate was 76%. Short-term contrast washout rate and perfusion are highly correlated (R2=0.72), and the pixel-wise relationship between circumferential strain and perfusion was better described with a sigmoidal Hill curve than linear functions. This study demonstrates the feasibility of measuring strain and perfusion from a single set of images. PMID:20544714

  7. Effects of preoperative administration of ketoprofen on whole blood platelet aggregation, buccal mucosal bleeding time, and hematologic indices in dogs undergoing elective ovariohysterectomy.

    PubMed

    Lemke, Kip A; Runyon, Caroline L; Horney, Barbara S

    2002-06-15

    To determine effects of preoperative administration of ketoprofen on whole blood platelet aggregation, buccal mucosal bleeding time, and hematologic indices in dogs after elective ovariohysterectomy. Randomized, masked clinical trial. 22 healthy dogs. 60 minutes before induction of anesthesia, 11 dogs were given 0.9% NaCl solution (control), and 11 dogs were given ketoprofen (2 mg/kg [0.9 mg/lb], IM). Thirty minutes before induction of anesthesia, glycopyrrolate (0.01mg/kg [0.005 mg/lb]), acepromazine (0.05 mg/kg [0.02 mg/lb]), and butorphanol (0.2 mg/kg 10.09 mg/lb]) were given IM to all dogs. Anesthesia was induced with thiopental (5 to 10 mg/kg [2.3 to 4.5 mg/lb], IV) and maintained with isoflurane (1 to 3%). Ovariohysterectomy was performed and butorphanol (0.1 mg/kg [0.05 mg/lb], IV) was given 15 minutes before completion of surgery. Blood samples for measurement of variables were collected at intervals before and after surgery. In dogs given ketoprofen, platelet aggregation was decreased 95 +/- 10% and 80 +/- 35% (mean +/- SD) immediately after surgery and 24 hours after surgery, respectively, compared with preoperative values. At both times, mean values in dogs given ketoprofen differed significantly from those in control dogs. Significant differences between groups were not observed for mucosal bleeding time or hematologic indices. Preoperative administration of ketoprofen inhibited platelet aggre gation but did not alter bleeding time. Ketoprofen can be given before surgery to healthy dogs undergoing elective ovariohysterectomy, provided that dogs are screened for potential bleeding problems before surgery and monitored closely after surgery.

  8. Effect of cardiopulmonary bypass on gastrointestinal perfusion and function.

    PubMed

    Gaer, J A; Shaw, A D; Wild, R; Swift, R I; Munsch, C M; Smith, P L; Taylor, K M

    1994-02-01

    Gastric mucosal tonometry was used to determine the adequacy of gastrointestinal perfusion in 10 patients undergoing elective myocardial revascularization. Patients were prospectively randomized to receive either pulsatile or nonpulsatile flow during cardiopulmonary bypass. All patients showed a reduction in gastric mucosal perfusion during bypass, manifested by a reduction in the gastric mucosal pH, which occurred independently of variations in the arterial pH. In the group of patients receiving nonpulsatile flow, this reduction was significantly greater (p < 0.05). Cardiopulmonary bypass using nonpulsatile flow is associated with the development of a gastric mucosal acidosis, which may have implications for the development of postoperative complications.

  9. Optimization of dual-saturation single bolus acquisition for quantitative cardiac perfusion and myocardial blood flow maps.

    PubMed

    Sánchez-González, Javier; Fernandez-Jiménez, Rodrigo; Nothnagel, Nils D; López-Martín, Gonzalo; Fuster, Valentin; Ibañez, Borja

    2015-02-19

    In-vivo quantification of cardiac perfusion is of great research and clinical value. The dual-bolus strategy is universally used in clinical protocols but has known limitations. The dual-saturation acquisition strategy has been proposed as a more accurate alternative, but has not been validated across the wide range of perfusion rates encountered clinically. Dual-saturation acquisition also lacks a clinically-applicable procedure for optimizing parameter selection. Here we present a comprehensive validation study of dual-saturation strategy in vitro and in vivo. The impact of saturation time and profile ordering in acquisitions was systematically analyzed in a phantom consisting of 15 tubes containing different concentrations of contrast agent. In-vivo experiments in healthy pigs were conducted to evaluate the effect of R2* on the definition of the arterial input function (AIF) and to evaluate the relationship between R2* and R1 variations during first-pass of the contrast agent. Quantification by dual-saturation perfusion was compared with the reference-standard dual-bolus strategy in 11 pigs with different grades of myocardial perfusion. Adequate flow estimation by the dual-saturation strategy is achieved with myocardial tissue saturation times around 100 ms (always <30 ms of AIF), with the lowest echo time, and following a signal model for contrast conversion that takes into account the residual R2* effect and profile ordering. There was a good correlation and agreement between myocardial perfusion quantitation by dual-saturation and dual-bolus techniques (R(2) = 0.92, mean difference of 0.1 ml/min/g; myocardial perfusion ranges between 0.18 and 3.93 ml/min/g). The dual-saturation acquisition strategy produces accurate estimates of absolute myocardial perfusion in vivo. The procedure presented here can be applied with minimal interference in standard clinical procedures.

  10. Brain luxury perfusion during cardiopulmonary bypass in humans. A study of the cerebral blood flow response to changes in CO2, O2, and blood pressure.

    PubMed

    Henriksen, L

    1986-06-01

    CBF and related parameters were studied in 68 patients before, during, and following cardiopulmonary bypass. CBF was measured using the intraarterial 133Xe injection method. The extracorporeal circuit was nonpulsatile with a bubble oxygenator administering 3-5% CO2 in the main group of hypercapnic patients (n = 59) and no CO2 in a second group of hypocapnic patients. In the hypercapnic patients, marked changes in CBF occurred during bypass. Evidence was found of a brain luxury perfusion that could not be related to the effect of CO2 per se. Mean CBF was 29 ml/100 g/min just before bypass, 49 ml/100 g/min at steady-state hypothermia (27 degrees C), reached a maximum of 73 ml/100 g/min during the rewarming phase (32 degrees C), fell to 56 ml/100 g/min at steady-state normothermic bypass (37 degrees C), and was 48 ml/100 g/min shortly after bypass was stopped. Addition of CO2 evoked systemic vasodilation with low blood pressure and a rebound hyperemia. The hypocapnic group responded more physiologically to the induced changes in hematocrit (Htc) and temperature, CBF being 25, 23, 25, 34, and 35 ml/100 g/min, respectively, during the five corresponding periods. Carbon dioxide was an important regulator of CBF during all phases of cardiac surgery, the responsiveness of CBF being approximately 4% for each 1-mm Hg change of PaCO2. The level of MABP was important for the CO2 response. At low blood pressure states, the CBF responsiveness to changes in PaCO2 was almost abolished. An optimal level of PaCO2 during hypothermic bypass of approximately 25 mm Hg (at actual temperature) is recommended. A normal autoregulatory response of CBF to changes in blood pressure was found during and following bypass. The lower limit of autoregulation was at pressure levels of approximately 50-60 mm Hg. CBF autoregulation was almost abolished at PaCO2 levels of greater than 50 mm Hg. The degree of hemodilution neither affected the CO2 response nor impaired CBF autoregulation, although, as

  11. [Preliminary study on assessment of lexiscan-induced blood-brain barrier opening and its level by CT perfusion imaging].

    PubMed

    Duan, Y; Yang, B Q; Chang, C C; Zhou, J; Li, H Y; Xu, Z H; Wang, Z W; Li, D Y

    2016-09-20

    Objective: To evaluate the level of lexiscan-induced blood-brain barrier opening of healthy rabbits via CT perfusion weighted imaging (PWI) scan. Methods: Between November 2014 and May 2015, thirty New Zealand white rabbits were randomly assigned into three groups: the experimental group A1 which received one injection of lexiscan(1 ml/kg); the experimental group A2 which received three times injection of lexiscan(total dose: 1.5 ml/kg), finished within 15 minutes; the control group B which was injected the same volume normal saline(1 ml/kg), after 30 minutes, CT PWI scan was performed. Then cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT) and permeability surface(PS) of the region of interest of each group were acquired and compared statistically. Five cases of each group were injected with 2% Evans blue intravenously posterior to imaging. After one hour of infusion, all the animals were killed. Their brains were examined for the determination of Evans blue distribution. Results: Both the values of CBF and CBV and the staining with Evans blue of the group A1(CBF: (89.88±2.21), (81.42±4.28) ml·(100 g)(-1)·min(-1); CBV: (3.97±0.43), (3.66±0.16) ml/g)and group A2 (CBF: (75.16±0.84), (63.66±7.21) ml·(100 g)(-1)·min(-1); CBV: (4.07±0.01), (3.75±0.05) ml/g) were higher than those of the group B(CBF: (20.08±5.08), (14.58±8.62) ml·(100 g)(-1)·min(-1); CBV: (0.85±0.04), (0.65±0.17) ml/g), the differences were all statistically significant (all P<0.01). While there was no statistically difference between group A1 and group A2(P>0.05). The value of PS of the group A2((22.43±8.09), (20.20±7.01)ml·(100 g)(-1)·min(-1) )was higher than that of group A1((13.82±4.44), (10.12±2.44)ml·(100 g)(-1)·min(-1)) and group B(0.00, 0.00)(the lowest one), the differences were all statistically significant(all P<0.01). The value of MTT of the group A1((2.50±0.82, 2.47±0.10) s) had no statistical difference with group A2 and group B

  12. Influence of antihypertensive therapy on cerebral perfusion in patients with metabolic syndrome: relationship with cognitive function and 24-h arterial blood pressure monitoring.

    PubMed

    Efimova, Nataliya Y; Chernov, Vladimir I; Efimova, Irina Y; Lishmanov, Yuri B

    2015-08-01

    To investigate the regional cerebral blood flow, cognitive function, and parameters of 24-h arterial blood pressure monitoring in patients with metabolic syndrome before and after combination antihypertensive therapy. The study involved 54 patients with metabolic syndrome (MetS) investigated by brain single-photon emission computed tomography, 24-h blood pressure monitoring (ABPM), and comprehensive neuropsychological testing before and after 24 weeks of combination antihypertensive therapy. Patients with metabolic syndrome had significantly poorer regional cerebral blood flow compared with control group: by 7% (P = 0.003) in right anterior parietal cortex, by 6% (P = 0.028) in left anterior parietal cortex, by 8% (P = 0.007) in right superior frontal lobe, and by 10% (P = 0.00002) and 7% (P = 0.006) in right and left temporal brain regions, correspondingly. The results of neuropsychological testing showed 11% decrease in mentation (P = 0.002), and 19% (P = 0.011) and 20% (P = 0.009) decrease in immediate verbal and visual memory in patients with MetS as compared with control group. Relationships between the indices of ABPM, cerebral perfusion, and cognitive function were found. Data showed an improvement of regional cerebral blood flow, ABPM parameters, and indicators of cognitive functions after 6 months of antihypertensive therapy in patients with MetS. The study showed the presence of diffuse disturbances in cerebral perfusion is associated with cognitive disorders in patients with metabolic syndrome. Combination antihypertensive treatment exerts beneficial effects on the 24-h blood pressure profile, increases cerebral blood flow, and improves cognitive function in patients with MetS. © 2015 John Wiley & Sons Ltd.

  13. Compilation of basal metabolic and blood perfusion rates in various multi-compartment, whole-body thermoregulation models.

    PubMed

    Shitzer, Avraham; Arens, Edward; Zhang, Hui

    2016-07-01

    The assignments of basal metabolic rates (BMR), basal cardiac output (BCO), and basal blood perfusion rates (BBPR) were compared in nine multi-compartment, whole-body thermoregulation models. The data are presented at three levels of detail: total body, specific body regions, and regional body tissue layers. Differences in the assignment of these quantities among the compared models increased with the level of detail, in the above order. The ranges of variability in the total body BMR was 6.5 % relative to the lowest value, with a mean of 84.3 ± 2 W, and in the BCO, it was 8 % with a mean of 4.70 ± 0.13 l/min. The least variability among the body regions is seen in the combined torso (shoulders, thorax, and abdomen: ±7.8 % BMR and ±5.9 % BBPR) and in the combined head (head, face, and neck ±9.9 % BMR and ±10.9 % BBPR), determined by the ratio of the standard deviation to the mean. Much more variability is apparent in the extremities with the most showing in the BMR of the feet (±117 %), followed by the BBPR in the arms (±61.3 %). In the tissue layers, most of the bone layers were assigned zero BMR and BBPR, except in the shoulders and in the extremities that were assigned non-zero values in a number of models. The next lowest values were assigned to the fat layers, with occasional zero values. Skin basal values were invariably non-zero but involved very low values in certain models, e.g., BBPR in the feet and the hands. Muscle layers were invariably assigned high values with the highest found in the thorax, abdomen, and legs. The brain, lung, and viscera layers were assigned the highest of all values of both basal quantities with those of the brain layers showing rather tight ranges of variability in both basal quantities. Average basal values of the "time-seasoned" models presented in this study could be useful as a first step in future modeling efforts subject to appropriate adjustment of values to conform to most recently available and

  14. Compilation of basal metabolic and blood perfusion rates in various multi-compartment, whole-body thermoregulation models

    NASA Astrophysics Data System (ADS)

    Shitzer, Avraham; Arens, Edward; Zhang, Hui

    2016-07-01

    The assignments of basal metabolic rates (BMR), basal cardiac output (BCO), and basal blood perfusion rates (BBPR) were compared in nine multi-compartment, whole-body thermoregulation models. The data are presented at three levels of detail: total body, specific body regions, and regional body tissue layers. Differences in the assignment of these quantities among the compared models increased with the level of detail, in the above order. The ranges of variability in the total body BMR was 6.5 % relative to the lowest value, with a mean of 84.3 ± 2 W, and in the BCO, it was 8 % with a mean of 4.70 ± 0.13 l/min. The least variability among the body regions is seen in the combined torso (shoulders, thorax, and abdomen: ±7.8 % BMR and ±5.9 % BBPR) and in the combined head (head, face, and neck ±9.9 % BMR and ±10.9 % BBPR), determined by the ratio of the standard deviation to the mean. Much more variability is apparent in the extremities with the most showing in the BMR of the feet (±117 %), followed by the BBPR in the arms (±61.3 %). In the tissue layers, most of the bone layers were assigned zero BMR and BBPR, except in the shoulders and in the extremities that were assigned non-zero values in a number of models. The next lowest values were assigned to the fat layers, with occasional zero values. Skin basal values were invariably non-zero but involved very low values in certain models, e.g., BBPR in the feet and the hands. Muscle layers were invariably assigned high values with the highest found in the thorax, abdomen, and legs. The brain, lung, and viscera layers were assigned the highest of all values of both basal quantities with those of the brain layers showing rather tight ranges of variability in both basal quantities. Average basal values of the "time-seasoned" models presented in this study could be useful as a first step in future modeling efforts subject to appropriate adjustment of values to conform to most recently available and reliable data.

  15. The effects of progressive anemia on jejunal mucosal and serosal tissue oxygenation in pigs.

    PubMed

    Haisjackl, M; Luz, G; Sparr, H; Germann, R; Salak, N; Friesenecker, B; Deusch, E; Meusburger, S; Hasibeder, W

    1997-03-01

    Anemia may promote intestinal hypoxia. We studied the effects of progressive isovolemic hemodilution on jejunal mucosal (Po2muc), and serosal tissue oxygen tension (Po2ser, Clark-type surface electrodes), mucosal microvascular hemoglobin oxygen saturation (Hbo2muc), and hematocrit (Hctmuc; tissue reflectance spectophotometry) in a jejunal segment. Twelve domestic pigs were anesthetized, paralyzed, and mechanically ventilated. Laparatomy was performed, arterial supply of a jejunal segment isolated, and constant pressure pump perfused. Seven animals were progressively hemodiluted to systemic hematocrits (Hctsys) of 20%, 15%, 10%, and 6%. Baseline for Po2muc, Po2ser and Hbo2muc was 23.5 +/- 2.1 mm Hg, 57.5 +/- 4 mm Hg, and 47.0% +/- 6.4% which were not different from the five controls. Despite a significant increase in jejunal blood flow, jejunal oxygen delivery decreased and oxygen extraction ratio increased significantly at Hctsys 10% and 6%. Po2ser decreased significantly below or at Hctsys of 15%, whereas Po2muc and Hbo2muc were maintained to Hctsys of 10%, but less than 10% Hbo2muc and mesenteric venous pH decreased significantly, implying that physiological limits of jejunal microvascular adaptation to severe anemia were reached. Decrease of Hctmuc was less pronounced than Hctsys. In conclusion, redistribution of jejunal blood flow and an increase in the ratio of mucosal to systemic hematocrit are the main mechanisms maintaining mucosal oxygen supply during progressive anemia.

  16. Peripheral blood lymphocyte typing as a useful tool to objectify the oral mucosa patch test in the diagnosis of allergic contact mucositis to nickel.

    PubMed

    Di Tola, Marco; Amodeo, Rachele; Marino, Mariacatia; Tabacco, Fabio; Casale, Rossella; Bove, Maurizio; Rossi, Alfredo; Cardelli, Patrizia; Picarelli, Antonio

    2014-06-01

    Nickel (Ni) exposure through the intestinal mucosa may cause a hypersensitivity reaction recently defined as allergic contact mucositis (ACM). This condition is identifiable by the oral mucosa patch test (omPT), a qualitative and subjective examination that requires clinical expertise. Our aim was to evaluate if a peripheral blood lymphocyte typing performed before and after the omPT for Ni may be able to objectify this examination for diagnostic purposes. Thirty patients with symptoms referable to the ingestion of Ni-rich foods were subjected to omPT for Ni. Before and after the omPT, each patient underwent blood sampling for the typing of total lymphocytes and their subsets (T, T helper or Th, T cytotoxic or Tc, B, natural killer or NK). Statistical analysis was performed by Student t test and receiver operating characteristic (ROC) curve analysis. According to the omPT outcomes, 18 patients were defined as Ni-sensitive and the remaining 12 as controls. In Ni-sensitive patients, the number of total, T, Th, Tc, and B lymphocytes/μL whole blood increased after the omPT (p<0.0001 for the first three, p=0.0004 and p=0.0001 for the last two lymphocyte types). No omPT-dependent lymphocyte increase was observed in controls. The post/pre omPT cell ratio, especially if calculated for Th lymphocytes, appears to be an effective index for diagnostic purposes (sensitivity=100%, specificity=83.3%, Youden index=0.833, area under curve (AUC)=0.926, p<0.0001). In conclusion, the peripheral blood lymphocyte typing with calculation of post/pre omPT cell ratio has the potential to support the omPT in diagnosing ACM, with the advantage of providing quantitative and objective data.

  17. The effects of oral administration of Yunnan Baiyao on blood coagulation in beagle dogs as measured by kaolin-activated thromboelastography and buccal mucosal bleeding times.

    PubMed

    Frederick, Jami; Boysen, Søren; Wagg, Catherine; Chalhoub, Serge

    2017-01-01

    We examined the effects of oral administration of Yunnan Baiyao (YB) on hemostasis by measuring buccal mucosal bleeding times (BMBTs) and doing citrated kaolin-activated whole-blood thromboelastography (TEG). In a randomized controlled crossover trial 8 beagle dogs were given either placebo or 1000 mg of YB orally every 12 h for 5 consecutive treatments. Blood was drawn 24 h before treatment and 2 and 24 h after the last treatment, and the BMBT was measured in each sample in duplicate. The TEG analysis was done in duplicate 60 ± 5 min after sample collection. There were no adverse effects of treatment and no significant differences between the control and treatment BMBTs or TEG parameters at any time point. Significant differences were found between baseline and 24 h after the last treatment within the treatment group for the TEG parameters LY30 and LY60 and within the control group for the TEG parameters MA, G, LY30, and LY60. Thus, at the dose and frequency of administration in this study YB did not appear to have any clinically significant effects on the measured coagulation parameters. The differences within the treatment group were likely due to analytic error since similar differences were seen in the control group. Further studies with a larger sample, as well as more direct measures of platelet function, are needed.

  18. T2-prepared steady-state free precession blood oxygen level-dependent MR imaging of myocardial perfusion in a dog stenosis model.

    PubMed

    Shea, Steven M; Fieno, David S; Schirf, Brian E; Bi, Xiaoming; Huang, Jie; Omary, Reed A; Li, Debiao

    2005-08-01

    To assess the ability of a T2-prepared steady-state free precession blood oxygen level-dependent (BOLD) magnetic resonance (MR) imaging sequence to depict changes in myocardial perfusion during stress testing in a dog stenosis model. Study was approved by the institutional Animal Care and Use Committee. A hydraulic occluder was placed in the left circumflex coronary artery (LCX) in 10 dogs. Adenosine was administered intravenously to increase coronary blood flow, and stenosis was achieved in the LCX with the occluder. A T2-prepared two-dimensional steady-state free precession sequence was used for BOLD imaging at a spatial resolution of 1.5 x 1.2 x 5.0 mm3, and first-pass perfusion images were acquired for visual comparison. Microspheres were injected to provide regional perfusion information. Mixed-effect regression analysis was performed to assess normalized MR signal intensity ratios and microsphere-measured perfusion differences. For the same data, 95% prediction intervals were calculated to determine the smallest perfusion change detectable. Means +/- standard deviations were calculated for myocardial regional comparison data. A two-tailed Student t test was used to determine if significant differences (P < .01) existed between different myocardial regions. Under maximal adenosine stress, MR clearly depicted stenotic regions and showed regional signal differences between the left anterior descending coronary artery (LAD)-fed myocardium and the stenosed LCX-fed myocardium. Visual comparisons with first-pass images were also excellent. Regional MR signal intensity differences between LAD and LCX-fed myocardium (1.24 +/- 0.08) were significantly different (P < .01) from differences between LAD and septal-fed myocardium (1.02 +/- 0.07), which was in agreement with microsphere-measured flow differences (LAD/LCX, 3.38 +/- 0.83; LAD/septal, 1.26 +/- 0.49). The linear mixed-effect regression model showed good correlation (R = 0.79) between MR differences and

  19. Measurement of myocardial blood flow by cardiovascular magnetic resonance perfusion: comparison of distributed parameter and Fermi models with single and dual bolus.

    PubMed

    Papanastasiou, Giorgos; Williams, Michelle C; Kershaw, Lucy E; Dweck, Marc R; Alam, Shirjel; Mirsadraee, Saeed; Connell, Martin; Gray, Calum; MacGillivray, Tom; Newby, David E; Semple, Scott Ik

    2015-02-17

    Mathematical modeling of cardiovascular magnetic resonance perfusion data allows absolute quantification of myocardial blood flow. Saturation of left ventricle signal during standard contrast administration can compromise the input function used when applying these models. This saturation effect is evident during application of standard Fermi models in single bolus perfusion data. Dual bolus injection protocols have been suggested to eliminate saturation but are much less practical in the clinical setting. The distributed parameter model can also be used for absolute quantification but has not been applied in patients with coronary artery disease. We assessed whether distributed parameter modeling might be less dependent on arterial input function saturation than Fermi modeling in healthy volunteers. We validated the accuracy of each model in detecting reduced myocardial blood flow in stenotic vessels versus gold-standard invasive methods. Eight healthy subjects were scanned using a dual bolus cardiac perfusion protocol at 3T. We performed both single and dual bolus analysis of these data using the distributed parameter and Fermi models. For the dual bolus analysis, a scaled pre-bolus arterial input function was used. In single bolus analysis, the arterial input function was extracted from the main bolus. We also performed analysis using both models of single bolus data obtained from five patients with coronary artery disease and findings were compared against independent invasive coronary angiography and fractional flow reserve. Statistical significance was defined as two-sided P value < 0.05. Fermi models overestimated myocardial blood flow in healthy volunteers due to arterial input function saturation in single bolus analysis compared to dual bolus analysis (P < 0.05). No difference was observed in these volunteers when applying distributed parameter-myocardial blood flow between single and dual bolus analysis. In patients, distributed parameter

  20. Glucagon-like peptide-2 (GLP-2) increases small intestinal blood flow and mucosal growth in ruminating calves

    USDA-ARS?s Scientific Manuscript database

    Glucagon-like peptide-2 (GLP-2), increases small intestinal mass and blood flow in non-ruminants, but its effect in ruminants is unknown. Eight Holstein calves with an ultrasonic flow probe around the superior mesenteric artery (SMA), and catheters in the carotid artery and mesenteric vein, were pa...

  1. Enteral arginine does not increase superior mesenteric arterial blood flow and but induces mucosal growth in neonatal pigs

    USDA-ARS?s Scientific Manuscript database

    Arginine is an essential amino acid in neonates synthesized by gut epithelial cells and a precursor for nitric oxide (NO) that regulates vasodilatation and blood flow. Arginine supplementation has been shown to improve intestinal integrity in ischemia-reperfusion models and low plasma levels are ass...

  2. Low local blood perfusion, high white blood cell and high platelet count are associated with primary tumor growth and lung metastasis in a 4T1 mouse breast cancer metastasis model.

    PubMed

    Wang, Chuan; Chen, Ying-Ge; Gao, Jian-Li; Lyu, Gui-Yuan; Su, Jie; Zhang, Q I; Ji, Xin; Yan, Ji-Zhong; Qiu, Qiao-Li; Zhang, Yue-Li; Li, Lin-Zi; Xu, Han-Ting; Chen, Su-Hong

    2015-08-01

    It was originally thought that no single routine blood test result would be able to indicate whether or not a patient had cancer; however, several novel studies have indicated that the median survival and prognosis of cancer patients were markedly associated with the systemic circulation features of cancer patients. In addition, certain parameters, such as white blood cell (WBC) count, were largely altered in malignant tumors. In the present study, routine blood tests were performed in order to observe the change of blood cells in tumor-bearing mice following the implantation of 4T1 breast cancer cells into the mammary fat pad; in addition, blood flow in breast tumor sites was measured indirectly using laser Doppler perfusion imaging (LDPI), in an attempt to explain the relevance between the blood circulation features and the growth or metastasis of breast cancer in mice model. The LDPI and blood test results indicated that the implantation of 4T1 breast cancer cells into BALB/c mice led to thrombosis as well as high WBC count, high platelet count, high plateletcrit and low blood perfusion. Following implantation of the 4T1 cells for four weeks, the lung metastatic number was determined and the Pearson correlation coefficient revealed that the number of visceral lung metastatic sites had a marked negative association with the ratio of basophils (BASO%; r=-0.512; P<0.01) and the mean corpuscular hemoglobin was significantly correlated with primary tumor weight (r=0.425; P<0.05). In conclusion, the results of the present study demonstrated that tumor growth led to thrombosis and acute anemia in mice; in addition, when blood BASO% was low, an increased number of lung metastases were observed in tumor-bearing mice.

  3. Nitric oxide generation by endothelial cells exposed to shear stress in glass tubes perfused with red blood cell suspensions: role of aggregation.

    PubMed

    Yalcin, Ozlem; Ulker, Pinar; Yavuzer, Ugur; Meiselman, Herbert J; Baskurt, Oguz K

    2008-05-01

    Endothelial function is modulated by wall shear stress acting on the vessel wall, which is determined by fluid velocity and the local viscosity near the vessel wall. Red blood cell (RBC) aggregation may affect the local viscosity by favoring axial migration. The aim of this study was to investigate the role of RBC aggregation, with or without altered plasma viscosity, in the mechanically induced nitric oxide (NO)-related mechanisms of endothelial cells. Human umbilical vein endothelial cells (HUVEC) were cultured on the inner surface of cylindrical glass capillaries that were perfused with RBC suspensions having normal and increased aggregation at a nominal shear stress of 15 dyn/cm(2). RBC aggregation was enhanced by two different approaches: 1) poloxamer-coated RBC suspended in normal, autologous plasma, resulting in enhanced aggregation but unchanged plasma viscosity and 2) normal RBC suspended in autologous plasma containing 0.5% dextran (mol mass 500 kDa), with a similar level of RBC aggregation but higher plasma viscosity. Compared with normal cells in unmodified plasma, perfusion with suspensions of poloxamer-coated RBC in normal plasma resulted in decreased levels of NO metabolites and serine 1177 phosphorylation of endothelial nitric oxide synthase (eNOS). Perfusion with normal RBC in plasma containing dextran resulted in a NO level that remained elevated, whereas only a modest decrease of phosphorylated eNOS level was observed. The results of this study suggest that increases of RBC aggregation tendency affect endothelial cell functions by altering local blood composition, especially if the alterations of RBC aggregation are due to modified cellular properties and not to plasma composition changes.

  4. Development of pulmonary blood flow evaluation method with a dynamic flat-panel detector: quantitative correlation analysis with findings on perfusion scan.

    PubMed

    Tanaka, Rie; Sanada, Shigeru; Fujimura, Masaki; Yasui, Masahide; Hayashi, Norio; Tsuji, Shiro; Okamoto, Hiroyuki; Nanbu, Yuko; Matsui, Osamu

    2010-01-01

    Pulmonary blood flow is reflected in dynamic chest radiographs as changes in X-ray translucency, i.e., pixel values. Thus, decreased blood flow should be observed as a reduction of the variation of X-ray translucency. We performed the present study to investigate the feasibility of pulmonary blood flow evaluation with a dynamic flat-panel detector (FPD). Sequential chest radiographs of 14 subjects were obtained with a dynamic FPD system. The changes in pixel value in each local area were measured and mapped on the original image by use of a gray scale in which small and large changes were shown in white and black, respectively. The resulting images were compared to the findings in perfusion scans. The cross-correlation coefficients of the changes in pixel value and radioactivity counts in each local area were also computed. In all patients, pulmonary blood flow disorder was indicated as a reduction of changes in pixel values on the mapping image, and a correlation was observed between the distribution of changes in pixel value and those in radioactivity counts (0.7 blood flow. The present method is potentially useful for evaluating pulmonary blood flow as an additional examination in conventional chest radiography.

  5. Comparison of Intraocular Pressure, Blood Pressure, Ocular Perfusion Pressure and Blood Flow Fluctuations During Dorzolamide Versus Timolol Add-On Therapy in Prostaglandin Analogue Treated Glaucoma Subjects

    PubMed Central

    Januleviciene, Ingrida; Siaudvytyte, Lina; Diliene, Vaida; Barsauskaite, Ruta; Paulaviciute-Baikstiene, Daiva; Siesky, Brent; Harris, Alon

    2012-01-01

    Objective: To compare the effects of dorzolamide and timolol add-on therapy in open-angle glaucoma (OAG) patients previously treated with prostaglandin analogue (Pg), by evaluating fluctuations in the intraocular (IOP), blood (BP), ocular perfusion pressures (OPP) and retrobulbar blood flow (RBF) parameters. Methods: 35 OAG patients (35 eyes), 31 women (88.6%) age 63.3 (8.9) years were evaluated in a 3 month randomized, cross-over, single-masked study. During the experiments BP, heart rate, IOP and OPP were assessed 4 times per day (8–12–16–20 h). RBF was measured twice per day (8–20 h) using Color Doppler imaging in the ophthalmic (OA), central retinal (CRA), nasal (nSPCA) and temporal (tSPCA) posterior ciliary arteries. In each vessel, peak systolic velocity (PSV) and end-diastolic velocity (EDV) were assessed and vascular resistance (RI) calculated. Results: Both add-on therapies lowered IOP in a statistically significant manner from 15.7 ± 2.4 mmHg at latanoprost baseline to 14.9 ± 2.2 mmHg using dorzolamide (p < 0.001) and 14.2 ± 1.9 mmHg using timolol (p < 0.001). The IOP lowering effect was statistically significant at 20 h, favoring timolol as compared to dorzolamide (1.4 ± 2.4 vs. 0.2 ± 2.1 mmHg), (p < 0.05). Dorzolamide add-on therapy showed smaller IOP (2.0 ± 1.4), SPP (13.3 ± 7.9), systolic BP (13.5 ± 8.7) and diastolic BP (8.4 ± 5.4) fluctuations as compared to both latanoprost baseline or timolol add-on therapies. Higher difference between morning and evening BP was correlated to decreased evening CRA EDV in the timolol group (c = −0.41; p = 0.01). With increased MAP in the morning or evening hours, we found increased evening OA RI in timolol add-on group (c = 0.400, p = 0.02; c = 0.513, p = 0.002 accordingly). Higher MAP fluctuations were related to impaired RBF parameters during evening hours-decreased CRA EDV (c = −0.408; p = 0.01), increased CRA RI (c = 0.576; p < 0.001) and tSPCA RI (c = 0.356; p = 0.04) in the dorzolamide

  6. [Effect of changes in airway pressure and the inspiratory volume on the fluid filtration rate and pulmonary artery pressure in isolated rabbit lungs perfused with blood and acellular solution].

    PubMed

    Crespo, Astrid; Novoa, Eva; Urich, Daniela; Trejo, Humberto; Pezzulo, Alejandro; Sznajder, Jacob I; Livia, Fernández; Sánchez-de León, Roberto

    2006-12-01

    It has been reported that ventilation with large tidal volumes causes pulmonary edema in rats by the stimulation and release of proinflammatory mediators. Our objective was to determine the level at which volutrauma induced by changes in Airway Pressure (PAW) and Inspiratory Volume (VI) produce significant changes on the Fluid Filtration Rate (FFR) and Pulmonary Artery Pressure (PAP) in lungs perfused with blood (cellular groups) or with a buffer-albumin solution (acellular groups), with a Positive End Expiratory Pressure (PEEP) 0 or 2 cmH2O and to study the effect of a vasodilator with antiinflammatory properties (fenoterol) in blood-perfused groups. Three experimental groups were used: the cellular groups studied the effect of increased PAW and IV in isolated lungs perfused with blood and PEEP 0 and 2; the acellular groups studied the increased PAW and IV in isolated lungs perfused with a buffer-albumin solution and PEEP 0 and 2; The fenoterol group studied the effect of increased PAW and IV in isolated lungs perfused with blood + fenoterol and PEEP 2. The results show that an increase of FFR is produced earlier in acellular groups than in cellular ones and that the damage in cellular groups is microscopically and macroscopically inferior when compared to acellular groups. Fenoterol did not inhibit edema formation, and that PEEP 2, both in the cellular and the acellular groups, has a protective effect. We propose the possible existence of mediators with protective effects against the formation of pulmonary edema in the blood. These data suggest that volutrauma induced pulmonary edema has a predominantly traumatic origin when the lungs are perfused with blood.

  7. Dutch perfusion incident survey.

    PubMed

    Groenenberg, Ingrid; Weerwind, Patrick W; Everts, Peter A M; Maessen, Jos G

    2010-09-01

    Cardiopulmonary bypass procedures remain complex, involving many potential risks. Therefore, a nationwide retrospective study was conducted to gain insight into the number of incidents and accidents in Dutch adult perfusion practice. An anonymous postal survey (85 questions about hardware, disposables, fluids and medication, air emboli, anticoagulation, practice, and safety measures) was sent to all Dutch perfusionists involved in adult cardiovascular perfusion during 2006 and 2007. To guarantee complete anonymity, respondents were asked to return the survey to a notary who discarded personal information. The net response rate was 72% and covered 23,500 perfusions. Individual respondents performed 240 ± 103 perfusions during the 2-year study period and had 13.8 ± 8.7 years of practical experience. The incident rate was 1 per 15.6 perfusions and the adverse event rate was 1 per 1,236 perfusions. The three most reported incidents were: (1) persistent inability to raise the activated coagulation time above 400s during perfusion (184 incidents); (2) an allergic or anaphylactic reaction to drugs, fluids, or blood products (114 incidents); and (3) clotting formation in the extracorporeal circuit (74 incidents). Furthermore, pre-bypass safety measures showed no statistically significant association with the reported incidents. In comparison with data from the recent literature, the reported number of incidents is high. Nevertheless, the adverse outcome rate is well matched to other published surveys. The relatively high response rate conveys the impression that the Dutch perfusionist is vigilant and willing to report incidents. Hence, a web-based Dutch perfusion incident registration system is recommended.

  8. Distribution of perfusion.

    PubMed

    Glenny, Robb; Robertson, H Thomas

    2011-01-01

    Local driving pressures and resistances within the pulmonary vascular tree determine the distribution of perfusion in the lung. Unlike other organs, these local determinants are significantly influenced by regional hydrostatic and alveolar pressures. Those effects on blood flow distribution are further magnified by the large vertical height of the human lung and the relatively low intravascular pressures in the pulmonary circulation. While the distribution of perfusion is largely due to passive determinants such as vascular geometry and hydrostatic pressures, active mechanisms such as vasoconstriction induced by local hypoxia can also redistribute blood flow. This chapter reviews the determinants of regional lung perfusion with a focus on vascular tree geometry, vertical gradients induced by gravity, the interactions between vascular and surrounding alveolar pressures, and hypoxic pulmonary vasoconstriction. While each of these determinants of perfusion distribution can be examined in isolation, the distribution of blood flow is dynamically determined and each component interacts with the others so that a change in one region of the lung influences the distribution of blood flow in other lung regions. © 2011 American Physiological Society.

  9. Functional changes in patients with internet addiction disclosed by adenosine stressed cerebral blood flow perfusion imaging (99m)Tc-ECD SPET.

    PubMed

    Liu, Guobing; Han, Lei; Hu, Yan; Xiao, Jie; Li, Yanli; Tan, Hui; Zhang, Yiqiu; Cheng, Dengfeng; Shi, Hongcheng

    2016-01-01

    To investigate the abnormal cerebral blood flow (CBF) perfusion in patients with internet addiction (IA) and its possible association with IA severity. Thirty-five adolescents who met the criteria for IA and 12 matched healthy volunteers were recruited for (99m)Tc-ethylcysteinate dimer based CBF perfusion imaging with single photon emission tomography (SPET) both at rest and in adenosine-stressed state. Regional CBF (rCBF) was measured and compared between IA subjects and the controls. Correlation analysis between those abnormal rCBF in adenosine-stressed state and the duration of IA was performed. At the resting state, the IA individuals showed significantly increased rCBF in the left mid-frontal gyrus and left angular gyrus, but significantly decreased in the left paracentral lobule, compared to the controls. In adenosine-stressed state, more cerebral regions with abnormal rCBF were identified. Specifically, increased rCBF was identified in the right paracentral lobule, right mid-frontal gyrus and left superior temporal gyrus, while decreased rCBF were demonstrated in right transverse temporal gyrus, left inferior frontal gyrus and left precuneus. Those rCBF in rCBF-increased regions in stress state were positively correlated with the duration of IA, while those in rCBF-decreased regions were negatively correlated with the duration of IA. We present specific functional changes in behaviour that may appear in IA patients related to the CBF findings in IA patients. Adenosine can be used as a pharmacological agent for stress CBF perfusion imaging in patients with IA, by which more cerebral regions of abnormal rCBF can be identified compared to the state at rest. These abnormal rCBF may indicate the neurological mechanism in IA patients.

  10. Arterial Spin-Labeled Perfusion Combined with Segmentation Techniques to Evaluate Cerebral Blood Flow in White and Gray Matter of Children with Sickle Cell Anemia

    PubMed Central

    Helton, Kathleen J.; Paydar, Amir; Glass, John; Weirich, Eric M.; Hankins, Jane; Li, Chin-Shang; Smeltzer, Matthew P.; Wang, Winfred C.; Ware, Russell E.; Ogg, Robert J.

    2015-01-01

    Background Changes in cerebral perfusion are an important feature of the pathophysiology of sickle cell anemia (SCA); cerebrovascular ischemia occurs frequently and leads to neurocognitive deficits, silent infarcts, and overt stroke. Non-invasive MRI methods to measure cerebral blood flow (CBF) by arterial spin labeling (ASL) afford new opportunities to characterize disease- and therapy-induced changes in cerebral hemodynamics in patients with SCA. Recent studies have documented elevated gray matter (GM) CBF in untreated children with SCA, but no measurements of white matter (WM) CBF have been reported. Procedures Pulsed ASL with automated brain image segmentation-classification techniques were used to determine the CBF in GM, WM, and abnormal white matter (ABWM) of 21 children with SCA, 18 of whom were receiving hydroxyurea therapy. Results GM and WM CBF were highly associated (R2 =.76, p< 0.0001) and the GM to WM CBF ratio was 1.6 (95% confidence interval: 1.43-1.83). Global GM CBF in our treated cohort was 87 ± 24 mL/min/100 g, a value lower than previously reported in untreated patients with SCA. CBF was elevated in normal appearing WM (43 ± 14 mL/min/100 g) but decreased in ABWM (6 ± 12 mL/min/100 g), compared to published normal pediatric controls. Hemispheric asymmetry in CBF was noted in most patients. Conclusions These perfusion measurements suggest that hydroxyurea may normalize GM CBF in children with SCA, but altered perfusion in WM may persist. This novel combined approach for CBF quantification will facilitate prospective studies of cerebral vasculopathy in SCA, particularly regarding the effects of treatments such as hydroxyurea. PMID:18937311

  11. The Effects of Oral Cryotherapy on Chemotherapy-Induced Oral Mucositis in Patients Undergoing Autologous Transplantation of Blood Stem Cells: A Clinical Trial

    PubMed Central

    Askarifar, Marzieh; Lakdizaji, Sima; Ramzi, Mani; Rahmani, Azad; Jabbarzadeh, Faranak

    2016-01-01

    Background Oral mucositis is one of the irritating side effects of chemotherapy in patients undergoing bone marrow transplantation. However, up until now, the common methods of oral mucositis therapy have failed to show significant effects. Objectives The aim of this study was to investigate the effects of local cryotherapy on the intensity of chemotherapy-induced oral mucositis in autologous bone marrow transplantation patients. Patients and Methods In this single, blinded, randomized clinical trial, 29 patients undergoing stem cell transplantation in Iran were selected by convenience sampling, and randomly allocated to control (n = 13) and intervention groups (n = 16). In the intervention group, cryotherapy was applied, while the control group received a normal saline mouthwash. The severity of the mucositis and neutrophil rate were investigated in five periods, based on the world health organization (WHO) scales. The data were analyzed using descriptive statistics, the Mann-Whitney test, repeated measures analysis of variance (ANOVA), and linear regression. Results In both groups, the mucositis reached its peak intensity on the 7th day, and the least intensity was obtained on the 21st day. The neutrophil rate reached the minimum value on the 7th day, then increased up to the 21st day. The two groups showed no significant differences between the mucositis severity on the 14th and 21st days (P = 0.164), while the severity of the mucositis in the cryotherapy group was significantly less than that in the saline mouthwash group (1.81 < 2.54 and 0.13 < 0.92, respectively) on the 7th and 14th days (P < 0.05). There was no significant difference in the neutrophil rate between the groups. Conclusions The results showed that cryotherapy is more effective than the saline mouthwash in reducing the severity of mucositis. This method is recommended for the prevention of mucositis in bone marrow transplantation. PMID:27257512

  12. 3D discrete angiogenesis dynamic model and stochastic simulation for the assessment of blood perfusion coefficient and impact on heat transfer between nanoparticles and malignant tumors.

    PubMed

    Yifat, Jonathan; Gannot, Israel

    2015-03-01

    Early detection of malignant tumors plays a crucial role in the survivability chances of the patient. Therefore, new and innovative tumor detection methods are constantly searched for. Tumor-specific magnetic-core nano-particles can be used with an alternating magnetic field to detect and treat tumors by hyperthermia. For the analysis of the method effectiveness, the bio-heat transfer between the nanoparticles and the tissue must be carefully studied. Heat diffusion in biological tissue is usually analyzed using the Pennes Bio-Heat Equation, where blood perfusion plays an important role. Malignant tumors are known to initiate an angiogenesis process, where endothelial cell migration from neighboring vasculature eventually leads to the formation of a thick blood capillary network around them. This process allows the tumor to receive its extensive nutrition demands and evolve into a more progressive and potentially fatal tumor. In order to assess the effect of angiogenesis on the bio-heat transfer problem, we have developed a discrete stochastic 3D model & simulation of tumor-induced angiogenesis. The model elaborates other angiogenesis models by providing high resolution 3D stochastic simulation, capturing of fine angiogenesis morphological features, effects of dynamic sprout thickness functions, and stochastic parent vessel generator. We show that the angiogenesis realizations produced are well suited for numerical bio-heat transfer analysis. Statistical study on the angiogenesis characteristics was derived using Monte Carlo simulations. According to the statistical analysis, we provide analytical expression for the blood perfusion coefficient in the Pennes equation, as a function of several parameters. This updated form of the Pennes equation could be used for numerical and analytical analyses of the proposed detection and treatment method.

  13. Contrast-enhanced ultrasound assessment of muscle blood perfusion of extremities that underwent crush injury: an animal experiment.

    PubMed

    Lv, Faqin; Tang, Jie; Luo, Yukun; Ban, Yu; Wu, Rong; Tian, Jiangke; Yu, Tengfei; Xie, Xia; Li, Tanshi

    2013-01-01

    This research aimed to study the assessment of local muscle microcirculation perfusion of extremities that underwent crush injuries by using contrast-enhanced ultrasonography (CEUS). A total of 28 New Zealand rabbits were anesthetized by using intramuscular pentobarbital sodium (30 mg/kg). A balloon cuff device was used to create crush injuries to the left hind leg of each rabbit with a force of 18.6 kPa. CEUS was performed at the 0.5th, 2nd, 6th,24th, and 72nd hour after the release of the crush pressure. Peak intensity (PI) of the crushed regions was compared with those of the uncrushed regions and before the creation of crush injury. Receiver operating characteristic analysis was used to determine the diagnostic value of PI for the crushed region. During the 72nd hour after the release of the crush pressure, 5 of the 28 rabbits died, and thus, their statistics were eliminated from the experiment. At different time points after the release of the crush pressure, the crushed regions in all 23 survivals showed quick and high enhancement, and their intensities were higher than those of the un crushed region in the arterial phase. The time-intensity curves of the crushed regions all appeared as rapid lift-gradual drop. PIs were obviously higher in the crushed regions than in the uncrushed regions and than those before the creation of crush injury ( p G 0.001). Receiver operating characteristic curves showed that extremity crush injury was diagnosed by using PI value. CEUS presents that the microcirculation perfusion of the crushed muscle increased obviously after the release of the crush pressure.PIs evaluated quantitatively the microcirculation perfusion changes. It may suggest a potential alternative for evaluating microcirculation abnormality of the muscle crush injury to the extremities.

  14. Effects of calcium infusion on secretion and motor activity of totally isolated canine stomach perfused with homologous blood.

    PubMed

    Kowalewski, K; Kolodej, A

    1976-01-01

    Isolated, ex vivo perfused, canine stomachs were used for this study. Gastric secretion, myoelectrical activity and mechanical activity were recorded during stimulation of gastric function with pentagastrin or histamine alone or combined with calcium gluconate. Secretagogues and calcium were infused into the gastric arterial circulation. Hypercalcemia induced significant inhibition of pentagastrin, stimulated gastric secretion, but did not affect the secretion stimulated by histamine. Hypercalcemia also induced an increase of frequency of cycles of electrical control activity and a decrease of mechanical activity of the gastric antrum. The effect of hypercalcemia on gastric motor function was similar in the nonstimulated stomach and during the infusion of secretagogues used in this experiment.

  15. The Ethanol-Induced Stimulation of Rat Duodenal Mucosal Bicarbonate Secretion In Vivo Is Critically Dependent on Luminal Cl–

    PubMed Central

    Sommansson, Anna; Wan Saudi, Wan Salman; Nylander, Olof; Sjöblom, Markus

    2014-01-01

    Alcohol may induce metabolic and functional changes in gastrointestinal epithelial cells, contributing to impaired mucosal barrier function. Duodenal mucosal bicarbonate secretion (DBS) is a primary epithelial defense against gastric acid and also has an important function in maintaining the homeostasis of the juxtamucosal microenvironment. The aim in this study was to investigate the effects of the luminal perfusion of moderate concentrations of ethanol in vivo on epithelial DBS, fluid secretion and paracellular permeability. Under thiobarbiturate anesthesia, a ∼30-mm segment of the proximal duodenum with an intact blood supply was perfused in situ in rats. The effects on DBS, duodenal transepithelial net fluid flux and the blood-to-lumen clearance of 51Cr-EDTA were investigated. Perfusing the duodenum with isotonic solutions of 10% or 15% ethanol-by-volume for 30 min increased DBS in a concentration-dependent manner, while the net fluid flux did not change. Pre-treatment with the CFTR inhibitor CFTRinh172 (i.p. or i.v.) did not change the secretory response to ethanol, while removing Cl− from the luminal perfusate abolished the ethanol-induced increase in DBS. The administration of hexamethonium (i.v.) but not capsazepine significantly reduced the basal net fluid flux and the ethanol-induced increase in DBS. Perfusing the duodenum with a combination of 1.0 mM HCl and 15% ethanol induced significantly greater increases in DBS than 15% ethanol or 1.0 mM HCl alone but did not influence fluid flux. Our data demonstrate that ethanol induces increases in DBS through a mechanism that is critically dependent on luminal Cl− and partly dependent on enteric neural pathways involving nicotinic receptors. Ethanol and HCl appears to stimulate DBS via the activation of different bicarbonate transporting mechanisms. PMID:25033198

  16. The ethanol-induced stimulation of rat duodenal mucosal bicarbonate secretion in vivo is critically dependent on luminal Cl-.

    PubMed

    Sommansson, Anna; Wan Saudi, Wan Salman; Nylander, Olof; Sjöblom, Markus

    2014-01-01

    Alcohol may induce metabolic and functional changes in gastrointestinal epithelial cells, contributing to impaired mucosal barrier function. Duodenal mucosal bicarbonate secretion (DBS) is a primary epithelial defense against gastric acid and also has an important function in maintaining the homeostasis of the juxtamucosal microenvironment. The aim in this study was to investigate the effects of the luminal perfusion of moderate concentrations of ethanol in vivo on epithelial DBS, fluid secretion and paracellular permeability. Under thiobarbiturate anesthesia, a ∼30-mm segment of the proximal duodenum with an intact blood supply was perfused in situ in rats. The effects on DBS, duodenal transepithelial net fluid flux and the blood-to-lumen clearance of 51Cr-EDTA were investigated. Perfusing the duodenum with isotonic solutions of 10% or 15% ethanol-by-volume for 30 min increased DBS in a concentration-dependent manner, while the net fluid flux did not change. Pre-treatment with the CFTR inhibitor CFTRinh172 (i.p. or i.v.) did not change the secretory response to ethanol, while removing Cl- from the luminal perfusate abolished the ethanol-induced increase in DBS. The administration of hexamethonium (i.v.) but not capsazepine significantly reduced the basal net fluid flux and the ethanol-induced increase in DBS. Perfusing the duodenum with a combination of 1.0 mM HCl and 15% ethanol induced significantly greater increases in DBS than 15% ethanol or 1.0 mM HCl alone but did not influence fluid flux. Our data demonstrate that ethanol induces increases in DBS through a mechanism that is critically dependent on luminal Cl- and partly dependent on enteric neural pathways involving nicotinic receptors. Ethanol and HCl appears to stimulate DBS via the activation of different bicarbonate transporting mechanisms.

  17. A new method for determining blood-brain barrier integrity based on intracardiac perfusion of an Evans Blue-Hoechst cocktail.

    PubMed

    del Valle, Jaume; Camins, Antoni; Pallàs, Mercè; Vilaplana, Jordi; Pelegrí, Carme

    2008-09-15

    A new method for determining brain regions with blood-brain barrier (BBB) alterations is described. In this method, mice were perfused intracardially with Evans Blue (EB) and Hoechst tracers added in a standard formaldehyde fixative solution. This cocktail method was tested after a localized cryolesion induced in the brain had produced an edematous brain region with disrupted BBB in the animals. The results were then compared with the intravenous and intraperitoneal administration of the tracers prior to intracardiac perfusion. When using the cocktail method, red EB fluorescence locates the cryoinjured brain region while the Hoechst tracer stains the nuclei in that same region. EB and Hoechst fluorescence can also be observed in the choroid plexus and circumventricular organs, where there is no functional BBB. The cocktail gives more intense EB staining in zones of disrupted BBB than that given by traditional methods which use this tracer. The Hoechst tracer is also more useful when administered in the cocktail, since when administrated intravenously it stains all the brain nuclei. The cocktail method permits the immunostaining of brain sections, enabling researchers to characterize and analyze structural and cellular changes in regions where BBB disturbances are present. Thus, immunohistochemistry has been used here to determine the nature of intense EB fluorescent cells that appear in the perilesional rim, which were identified here as neuronal cells.

  18. Effect of ethanol on jejunal regional blood flow in the rabbit.

    PubMed

    Buell, M G; Beck, I T

    1983-01-01

    The effects of intraluminal ethanol perfusion (3.0% and 6.0% vt/vol) on mucosal morphology, water transport, and regional blood flow were examined in in vivo jejunal segments of pentobarbital-anesthetized rabbits. Compared with control segments, ethanol-perfused segments exhibited morphological alterations of the mucosa consisting of subepithelial fluid accumulation (bleb formation), exfoliation of enterocytes, and vascular congestion. The prevalence of epithelial damage was significantly increased in the segments perfused with 6% ethanol. Net water transport was significant (p less than 0.025) depressed in segments perfused with 3.0% and 6.0% wt/vol ethanol. In animals in which the control segment was absorbing water, ethanol led to a depression in net water absorption or to the reversal of absorption to net secretion. In animals in which the control segment exhibited secretion, ethanol led to an enhanced net secretion. Blood flow through the total jejunal wall and through the luminal layer (consisting of mucosa plus submucosa) was significantly (p less than 0.05) increased by the presence of 3.0% and 6.0% wt/vol ethanol in the intestinal lumen. Blood flow in the external layer of the jejunum (consisting of muscularis plus serosa) did not change significantly. It therefore appears that the ethanol-induced alterations in jejunal mucosal morphology and water transport are accompanied by a localized mucosal or submucosal hyperemia, or both. However, a direct cause and effect relationship between these remains to be established.

  19. Longitudinal Assessment of Renal Perfusion and Oxygenation in Transplant Donor-Recipient Pairs Using Arterial Spin Labeling and Blood Oxygen Level-Dependent Magnetic Resonance Imaging.

    PubMed

    Niles, David J; Artz, Nathan S; Djamali, Arjang; Sadowski, Elizabeth A; Grist, Thomas M; Fain, Sean B

    2016-02-01

    The aims of this study were to assess renal function in kidney transplant recipients and their respective donors over 2 years using arterial spin labeling (ASL) and blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) and to prospectively evaluate the effect of losartan on functional MRI measures in recipients. The study included 15 matched pairs of renal transplant donors and recipients. Arterial spin labeling and BOLD MRI of the kidneys were performed on donors before transplant surgery (baseline) and on both donors and recipients at 3 months, 1 year, and 2 years after transplant. After 3 months, 7 of the 15 recipients were prescribed 25 to 50 mg/d losartan for the remainder of the study. A linear mixed-effects model was used to evaluate perfusion, R2*, estimated glomerular filtration rate, and fractional excretion of sodium for changes across time or associated with losartan treatment. In donors, cortical perfusion in the remaining kidney decreased by 50 ± 19 mL/min per 100 g (11.8%) between baseline and 2 years (P < 0.05), while cortical R2* declined modestly by 0.7 ± 0.3 s-1 (5.6%; P < 0.05). In transplanted kidneys, cortical perfusion decreased markedly by 141 ± 21 mL/min per 100 g (34.2%) between baseline and 2 years (P < 0.001), while medullary R2* declined by 1.5 ± 0.8 s-1 (8.3%; P = 0.06). Single-kidney estimated glomerular filtration rate increased between baseline and 2 years by 17.7 ± 2.7 mL/min per 1.73 m (40.3%; P < 0.0001) in donors and to 14.6 ± 4.3 mL/min per 1.73 m (33.3%; P < 0.01) in recipients. Cortical perfusion at 1 and 2 years in recipients receiving 25 to 50 mg/d losartan was 62 ± 24 mL/min per 100 g higher than recipients not receiving the drug (P < 0.05). No significant effects of losartan were observed for any other markers of renal function. The results suggest an important role for noninvasive functional monitoring with ASL and BOLD MRI in kidney transplant recipients and donors, and they indicate a potentially

  20. Cerebral perfusion pressure, and not cerebral blood flow, may be the critical determinant of intracranial injury in preeclampsia: a new hypothesis.

    PubMed

    Belfort, Michael A; Varner, Michael W; Dizon-Townson, Donna S; Grunewald, Charlotta; Nisell, Henry

    2002-09-01

    The relationship between cerebral perfusion pressure (CPP) and cerebral blood flow is unclear in preeclampsia. Our objective was to clarify this issue by comparing normal pregnant women to those with mild and severe preeclampsia. Patients with mild (n = 72) and severe (n = 120) preeclampsia underwent transcranial Doppler (TCD) imaging of the maternal middle cerebral artery (MCA). At the same time, blood pressure was taken with a Dinamap monitor (Dinamap; Criticon Inc, Tampa, Fla). CPP, resistance area product (RAP), and the cerebral flow index (CFI) were calculated by standard formulas. Data were plotted on normative curves for pregnancy (5% and 95%) and compared by chi(2) and Mann-Whitney U tests. CFI is usually normal in both severe (75%) and mild (72%) cases. If CFI is abnormal in severe cases, it may be either increased (14%) or decreased (10%), although in mild cases almost all abnormal CFI (25%) is lower than normal. In those cases with low or normal CFI, severe cases are associated with a significantly higher CPP, RAP, and MAP than mild cases (P <.05), although the CFI is not significantly different. A significant proportion of severe cases have high CPP (52%), whereas in mild cases the CPP is almost always normal (87%). Overall, in severe cases the RAP is abnormally high, although it is within the normal range in mild cases. One of the fundamental differences between mild and severe cases relates to the degree of cerebral perfusion pressure that the MCAs are subjected to. Because most preeclamptic women, regardless of degree of severity, have a normal CFI, it appears that autoregulation is generally intact. Because women with severe cases are more prone to cerebral catastrophe than those with mild preeclampsia, uncontrolled CPP may cause barotrauma and vessel damage, leading to hypertensive encephalopathy and overperfusion injury. Therapeutic strategies that ensure reduction of the CPP with maintenance of the CFI seem most likely to prevent the cerebral

  1. Extracorporeal shock-wave therapy enhanced wound healing via increasing topical blood perfusion and tissue regeneration in a rat model of STZ-induced diabetes.

    PubMed

    Kuo, Yur-Ren; Wang, Chun-Ting; Wang, Feng-Sheng; Chiang, Yuan-Cheng; Wang, Ching-Jen

    2009-01-01

    Extracorporeal shock-wave therapy (ESWT) has a significant positive effect in accelerating chronic wound healing. However, the bio-mechanisms operating during ESWT of wounds remain unclear. This study investigated the effectiveness of ESWT in the enhancement of diabetic wound healing. A dorsal skin defect (area, 6 x 5 cm) in a streptozotocin-induced diabetes rodent model was used. Fifty male Wistar rats were divided into five groups. Group I consisted of nondiabetic control; group II included diabetic control receiving no ESWT; group III included rats that underwent one session of ESWT (ESW-1) on day 3 (800 impulses at 0.09 mJ/mm(2)) postwounding; group IV included rats that underwent two sessions of ESWT (ESW-2) on days 3 and 7; and group V included rats that underwent three sessions of ESWT (ESW-3) on days 3, 7, and 10. The wound healing was assessed clinically. Blood perfusion scan was performed with laser Doppler. The VEGF, eNOS, and PCNA were analyzed with immunohistochemical stain. The results revealed that the wound size was significantly reduced in the ESWT-treated rats, especially in the ESW-2 and ESW-3 groups, as compared with the control (p<0.01). Blood perfusion was significantly increased after ESWT compared with the controls. Histological findings revealed a significant reduction in the topical pro-inflammatory reaction in the ESWT group as compared with the control. In immunohistochemical stain, significant increases in VEGF, eNOS, and PCNA expressions were observed in the ESWT group, especially in the ESW-2 and ESW-3 groups, as compared with the control. In conclusion, treatment with an optimal session of ESWT significantly enhanced diabetic wound healing associated with increased neo-angiogenesis and tissue regeneration, and topical anti-inflammatory response.

  2. Underestimation of myocardial blood flow by dynamic perfusion CT: Explanations by two-compartment model analysis and limited temporal sampling of dynamic CT.

    PubMed

    Ishida, Masaki; Kitagawa, Kakuya; Ichihara, Takashi; Natsume, Takahiro; Nakayama, Ryohei; Nagasawa, Naoki; Kubooka, Makiko; Ito, Tatsuro; Uno, Mio; Goto, Yoshitaka; Nagata, Motonori; Sakuma, Hajime

    2016-01-01

    Previous studies using dynamic perfusion CT and volume perfusion CT (VPCT) software consistently underestimated the stress myocardial blood flow (MBF) in normal myocardium to be 1.1-1.4 ml/min/g, whilst the O 15-water PET studies demonstrated the normal stress MBF of 3-5 ml/min/g. We hypothesized that the MBF determined by VPCT (MBF-VPCT) is actually presenting the blood-to-myocardium transfer constant, K1. In this study, we determined K1 using Patlak plot (K1-Patlak) and compared the results with MBF-VPCT. 17 patients (66 ± 9 years, 7 males) with suspected coronary artery disease (CAD) underwent stress dynamic perfusion CT, followed by rest coronary CT angiography (CTA). Arterial input and myocardial output curves were analyzed with Patlak plot to quantify myocardial K1. Significant CAD was defined as >50% stenosis on CTA. A simulation study was also performed to investigate the influence of limited temporal sampling in dynamic CT acquisition on K1 using the undersampling data generated from MRI. There were 3 patients with normal CTA, 7 patients with non-significant CAD, and 7 patients with significant CAD. K1-patlak was 0.98 ± 0.35 (range 0.22-1.67) ml/min/g, whereas MBF-VPCT was 0.83 ± 0.23 (range 0.34-1.40) ml/min/g. There was a linear relationship between them: (MBF-VPCT) = 0.58 x (K1-patlak) + 0.27 (r(2) = 0.65, p < 0.001). The simulation study done on MRI data demonstrated that Patlak plot substantially underestimated true K1 by 41% when true K1 was 2.0 ml/min/g with the temporal sampling of 2RR for arterial input and 4RR for myocardial output functions. The results of our study are generating hypothesis that MBF-VPCT is likely to be calculating K1-patlak equivalent, not MBF. In addition, these values may be substantially underestimated because of limited temporal sampling rate. Copyright © 2016 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

  3. [Mucosal immune system and mucosal vaccine].

    PubMed

    Yanagita, M; Hiroi, T; Kiyono, H

    1997-02-01

    In the recent years, mucosal immune system is recognized as the new world in the area of immunology. The host is continuously exposed to the numerous numbers of environmental antigens via the mucosa and the skin. A total surface area of the mucosa is approximately 200 times larger than that of the skin, and the former surface area contains a large numbers of lymphoid cells (> 10(11)). In order to provide an effective defence for the host by vaccine, it is logical to consider the mucosal immune system. According to the new informations obtained by the modern cellular and molecular immunobiological knowledges and approaches, the concept of the mucosal immune system has been rapidly proceeded to apply for the development of mucosal vaccine. In this report, we have reviewed and discussed the recent progress in the characterization of mucosal immune system and the development of mucosal vaccine.

  4. Identification of hemodynamically compromised regions by means of cerebral blood volume mapping utilizing computed tomography perfusion imaging.

    PubMed

    Takahashi, Satoshi; Tanizaki, Yoshio; Akaji, Kazunori; Kimura, Hiroaki; Katano, Takehiro; Suzuki, Kentaro; Mochizuki, Yoichi; Shidoh, Satoka; Nakazawa, Masaki; Yoshida, Kazunari; Mihara, Ban

    2017-04-01

    The aim of the study was to evaluate the potential role of computed tomography perfusion (CTP) imaging in identifying hemodynamically compromised regions in patients with occlusive cerebrovascular disease. Twelve patients diagnosed with either occlusion or severe stenosis of the internal carotid artery or the M1 portion of the middle cerebral artery underwent CTP imaging. The data was analyzed by an automated ROI-determining software. Patients were classified into two subgroups: an asymptomatic group consisting of three patients in whom perfusion pressure distal to the site of occlusion/stenosis (PPdis) could be maintained in spite of the arterial occlusion/stenosis, and a symptomatic group consisting of nine patients in whom PPdis could not be maintained enough to avoid watershed infarction. Four CTP-related parameters were independently compared between the two groups. Significant differences were determined using a two-sample t-test. When statistically significant differences were identified, cut-off points were calculated using ROC curves. Analysis revealed statistically significant differences between the asymptomatic and symptomatic subgroups only in the measure of relCBV (p=0.028). Higher relCBV values were observed in the symptomatic subgroup. ROC curve analysis revealed 1.059 to be the optimal relCBV cut-off value for distinguishing between the asymptomatic and symptomatic subgroups. The data revealed that, in patients whose PPdis is maintained, relCBV remains around 1.00. Conversely, in patients whose PPdis decreased, relCBV increased. From these findings, we conclude that elevation of relCBV as observed using CTP imaging accurately reflects the extent of compensatory vasodilatation involvement and can identify hemodynamically compromised regions.

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

    PubMed Central

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

    2016-01-01

    Objectives Angiogenesis and anti-angiogenetic medications play an important role in progression and therapy of glioblastoma. In this context, in vivo characterization of the blood-brain-barrier and tumor vascularization may be important for individual prognosis and therapy optimization. Methods We analyzed perfusion and capillary permeability of C6-gliomas in rats at different stages of tumor-growth by contrast enhanced MRI and dynamic susceptibility contrast (DSC) MRI at 7 Tesla. The analyses included maps of relative cerebral blood volume (CBV) and signal recovery derived from DSC data over a time period of up to 35 days after tumor cell injections. Results In all rats tumor progression was accompanied by temporal and spatial changes in CBV and capillary permeability. A leakage of the blood-brain barrier (slow contrast enhancement) was observed as soon as the tumor became detectable on T2-weighted images. Interestingly, areas of strong capillary permeability (fast signal enhancement) were predominantly localized in the center of the tumor. In contrast, the tumor rim was dominated by an increased CBV and showed the highest vessel density compared to the tumor center and the contralateral hemisphere as confirmed by histology. Conclusion Substantial regional differences in the tumor highlight the importance of parameter maps in contrast or in addition to region-of-interest analyses. The data vividly illustrate how MRI including contrast-enhanced and DSC-MRI may contribute to a better understanding of tumor development. PMID:28005983

  6. Monitoring stroke progression: in vivo imaging of cortical perfusion, blood-brain barrier permeability and cellular damage in the rat photothrombosis model.

    PubMed

    Schoknecht, Karl; Prager, Ofer; Vazana, Udi; Kamintsky, Lyn; Harhausen, Denise; Zille, Marietta; Figge, Lena; Chassidim, Yoash; Schellenberger, Eyk; Kovács, Richard; Heinemann, Uwe; Friedman, Alon

    2014-11-01

    Focal cerebral ischemia is among the main causes of death and disability worldwide. The ischemic core often progresses, invading the peri-ischemic brain; however, assessing the propensity of the peri-ischemic brain to undergo secondary damage, understanding the underlying mechanisms, and adjusting treatment accordingly remain clinically unmet challenges. A significant hallmark of the peri-ischemic brain is dysfunction of the blood-brain barrier (BBB), yet the role of disturbed vascular permeability in stroke progression is unclear. Here we describe a longitudinal in vivo fluorescence imaging approach for the evaluation of cortical perfusion, BBB dysfunction, free radical formation and cellular injury using the photothrombosis vascular occlusion model in male Sprague Dawley rats. Blood-brain barrier dysfunction propagated within the peri-ischemic brain in the first hours after photothrombosis and was associated with free radical formation and cellular injury. Inhibiting free radical signaling significantly reduced progressive cellular damage after photothrombosis, with no significant effect on blood flow and BBB permeability. Our approach allows a dynamic follow-up of cellular events and their response to therapeutics in the acutely injured cerebral cortex.

  7. Comparison of plaque accumulation and soft-tissue blood flow with the use of full-arch implant-supported fixed prostheses with mucosal surfaces of different materials: a randomized clinical study.

    PubMed

    Kanao, Masato; Nakamoto, Tetsuji; Kajiwara, Norihiro; Kondo, Yusuke; Masaki, Chihiro; Hosokawa, Ryuji

    2013-10-01

    The aims of this clinical study were to determine differences in plaque accumulation and to compare the effects of reinforced composite resin and titanium on peri-implant soft-tissue and residual-ridge inflammation. A total of 19 subjects were enrolled in this clinical trial; 10 jaws had implant-supported fixed prostheses with composite resin mucosal surfaces, 11 jaws had titanium prostheses fabricated by computer-aided design/computer-aided manufacture (CAD/CAM), and 6 jaws had acrylic resin prostheses. Plaque area indexes (PAIs) were calculated on the mucosal surfaces of prostheses, and blood flow in the mucosa was captured with two-dimensional laser speckle imaging to evaluate residual-ridge inflammation. Subjects were educated about oral hygiene and reevaluated after 3 months. The PAI was significantly lower on titanium mucosal surfaces than on reinforced composite resin surfaces at the initial and second measurements (initial, P = 0.0052; second, P = 0.0044). Self-curing acrylic resin surfaces did not show any significant difference when compared with reinforced resin or titanium. Blood flow was significantly lower in mucosa contacting titanium surfaces than in mucosa contacting reinforced composite resin surfaces at the initial measurement (P = 0.0330). Although subjects were instructed about plaque control after the initial measurement, PAIs indicated that the difference between the two materials could not be overcome. In terms of oral hygiene and mucosal inflammation, titanium was superior to reinforced composite resin in implant-supported fixed prostheses for edentulous subjects, and the short-term use of acrylic resin was superior to the use of reinforced composite resin. © 2012 John Wiley & Sons A/S.

  8. Effects of balanced hydroxyethyl starch solutions on gut mucosal microcirculation and exhaled nitric oxide in septic rats: A randomised, animal study.

    PubMed

    Langanke, Kristina; Hinkelmann, Jürgen; Fischer, Lars G; Van Aken, Hugo K; Sielenkamper, Andreas W; Ertmer, Christian; Freise, Hendrik

    2013-08-01

    Balanced hydroxyethyl starch (HES) solutions with a molecular weight of 130 kDa (tetrastarches) are frequently used in clinical practice. These solutions are derived either from waxy maize or potato starch and they are not bioequivalent. Investigation of the effects of waxy maize-derived and potato-derived starches on intestinal microcirculation and pulmonary inflammation in experimental sepsis. A randomised (three groups), blinded animal study. Animal experimental facility in a university hospital. Twenty-one male Sprague-Dawley rats weighing 275 to 300 g. Sepsis was induced by caecal ligation and puncture. Animals received balanced crystalloid infusion (6 ml kg h) for 23 h followed by randomised 1 h bolus infusion (30 ml kg h) of crystalloid: balanced crystalloid solution or waxy maize starch: 6% wt/vol HES 130/0.4 or potato starch: 6% wt/vol HES 130/0.42. Results are presented as median (interquartiles). Using intravital microscopy, mucosal perfusion was assessed by intercapillary area (ICA) between all perfused capillaries (ICAtotal) and continuously perfused capillaries only (ICAcont). Mucosal blood flow was calculated from arteriolar diameter and red blood cell velocity. Intestinal wall 3-nitrotyrosine (3-NTint) content and exhaled nitric oxide (exNO), to indicate pulmonary inflammation, were measured. Both tetrastarches improved capillary perfusion compared to the crystalloid group, as indicated by reduced ICAtotal [crystalloid 1054 (905 to 1211) μm; waxy maize starch 789 (744 to 940) μm, P <0.05; potato starch 674 (536 to 693) μm, P < 0.05] and reduced ICAcont [crystalloid 1060 (996 to 1340) μm; waxy maize starch 860 (793 to 975) μm, P <0.05; potato starch 701 (558 to 728) μm, P <0.05]. Mucosal blood flow and systemic blood pressure did not differ significantly between groups. 3-NTint was comparable among all groups. exNO was significantly reduced from 11.1 (5.0 to 16.5) ppb to 4.2 (4.0 to 4.8) ppb in the waxy

  9. 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.

  10. Cerebral Blood Volume Analysis in Glioblastomas Using Dynamic Susceptibility Contrast-Enhanced Perfusion MRI: A Comparison of Manual and Semiautomatic Segmentation Methods

    PubMed Central

    Jung, Seung Chai; Choi, Seung Hong; Yeom, Jeong A.; Kim, Ji-Hoon; Ryoo, Inseon; Kim, Soo Chin; Shin, Hwaseon; Lee, A. Leum; Yun, Tae Jin; Park, Chul-Kee; Sohn, Chul-Ho; Park, Sung-Hye

    2013-01-01

    Purpose To compare the reproducibilities of manual and semiautomatic segmentation method for the measurement of normalized cerebral blood volume (nCBV) using dynamic susceptibility contrast-enhanced (DSC) perfusion MR imaging in glioblastomas. Materials and Methods Twenty-two patients (11 male, 11 female; 27 tumors) with histologically confirmed glioblastoma (WHO grade IV) were examined with conventional MR imaging and DSC imaging at 3T before surgery or biopsy. Then nCBV (means and standard deviations) in each mass was measured using two DSC MR perfusion analysis methods including manual and semiautomatic segmentation method, in which contrast-enhanced (CE)-T1WI and T2WI were used as structural imaging. Intraobserver and interobserver reproducibility were assessed according to each perfusion analysis method or each structural imaging. Interclass correlation coefficient (ICC), Bland-Altman plot, and coefficient of variation (CV) were used to evaluate reproducibility. Results Intraobserver reproducibilities on CE-T1WI and T2WI were ICC of 0.74–0.89 and CV of 20.39–36.83% in manual segmentation method, and ICC of 0.95–0.99 and CV of 8.53–16.19% in semiautomatic segmentation method, repectively. Interobserver reproducibilites on CE-T1WI and T2WI were ICC of 0.86–0.94 and CV of 19.67–35.15% in manual segmentation method, and ICC of 0.74–1.0 and CV of 5.48–49.38% in semiautomatic segmentation method, respectively. Bland-Altman plots showed a good correlation with ICC or CV in each method. The semiautomatic segmentation method showed higher intraobserver and interobserver reproducibilities at CE-T1WI-based study than other methods. Conclusion The best reproducibility was found using the semiautomatic segmentation method based on CE-T1WI for structural imaging in the measurement of the nCBV of glioblastomas. PMID:23950891

  11. Blood circulation in the fingers is aggravated after creating a vascular access for dialysis: assessment using skin perfusion pressure.

    PubMed

    Sato, Makoto; Tahara, Shinya; Sugiyama, Daisuke; Terashi, Hiroto

    2014-10-01

    Internal vascular shunts for haemodialysis can cause different complications. One of the most serious complications is steal syndrome, which can result in disturbed peripheral circulation causing finger necrosis and lead to amputation. Thus, prevention of these complications is important. Measurement of skin perfusion pressure (SPP) has been used in various clinical settings, including wound-healing management, and its usefulness has been increasingly unveiled. The present study was undertaken to evaluate changes in haemodynamics after internal shunt creation by measuring SPP of the thumb and the little finger before and after surgery in five patients undergoing shunt surgery using the radial artery and the cephalic vein. The study revealed average changes of -22.8 mmHg in thumb SPP. The change in the thumb was statistically significant (p < 0.05). If the effect of surgery and the threshold for wound healing are taken into account, the present results indicate the necessity to pay extra attention to fingers with extremely low preoperative SPP values. For the prevention of serious disturbances of peripheral circulation (e.g. steal syndrome), routine preoperative SPP measurement seems effective for screening of high-risk patients.

  12. Diagnostic Accuracy of Endocardial-to-Epicardial Myocardial Blood Flow Ratio for the Detection of Significant Coronary Artery Disease With Dynamic Myocardial Perfusion Dual-Source Computed Tomography.

    PubMed

    Goto, Yoshitaka; Kitagawa, Kakuya; Uno, Mio; Nakamori, Shiro; Ito, Tatsuro; Nagasawa, Naoki; Dohi, Kaoru; Sakuma, Hajime

    2017-04-25

    Previous dynamic stress computed tomography perfusion (CTP) studies used absolute myocardial blood flow (MBF in mL/100 g/min) as a threshold to discriminate flow-limiting coronary artery disease (CAD), but absolute MBF can be vary because of multiple factors. The aim of this study was to compare the diagnostic performance of absolute MBF and the transmural perfusion ratio (TPR) for the detection of flow-limiting CAD, and to clarify the influence of CT delayed enhancement (CTDE) on the diagnostic performance of CTP.Methods and Results:We retrospectively enrolled 51 patients who underwent dual-source CTP and invasive coronary angiography (ICA). TPR was defined as the endocardial MBF of a specific segment divided by the mean of the epicardial MBF of all segments. Flow-limiting CAD was defined as luminal diameter stenosis >90% on ICA or a lesion with fractional flow reserve ≤0.8. Segmental presence and absence of myocardial scar was determined by CTDE. The area under the receiver-operating characteristics curve (AUC) of TPR was significantly greater than that of MBF for the detection of flow-limiting CAD (0.833 vs. 0.711, P=0.0273). Myocardial DE was present in 27 of the 51 patients and in 34 of 143 territories. When only territories containing DE were considered, the AUC of TPR decreased to 0.733. TPR calculated from absolute MBF demonstrated higher diagnostic performance for the discrimination of flow-limiting CAD when compared with absolute MBF itself.

  13. Vaccination strategies for mucosal immune responses.

    PubMed

    Ogra, P L; Faden, H; Welliver, R C

    2001-04-01

    Mucosal administration of vaccines is an important approach to the induction of appropriate immune responses to microbial and other environmental antigens in systemic sites and peripheral blood as well as in most external mucosal surfaces. The development of specific antibody- or T-cell-mediated immunologic responses and the induction of mucosally induced systemic immunologic hyporesponsiveness (oral or mucosal tolerance) depend on complex sets of immunologic events, including the nature of the antigenic stimulation of specialized lymphoid structures in the host, antigen-induced activation of different populations of regulatory T cells (Th1 versus Th2), and the expression of proinflammatory and immunoregulatory cytokines. Availability of mucosal vaccines will provide a painless approach to deliver large numbers of vaccine antigens for human immunization. Currently, an average infant will receive 20 to 25 percutaneous injections for vaccination against different childhood infections by 18 months of age. It should be possible to develop for human use effective, nonliving, recombinant, replicating, transgenic, and microbial vector- or plant-based mucosal vaccines to prevent infections. Based on the experience with many dietary antigens, it is also possible to manipulate the mucosal immune system to induce systemic tolerance against environmental, dietary, and possibly other autoantigens associated with allergic and autoimmune disorders. Mucosal immunity offers new strategies to induce protective immune responses against a variety of infectious agents. Such immunization may also provide new prophylactic or therapeutic avenues in the control of autoimmune diseases in humans.

  14. Vaccination Strategies for Mucosal Immune Responses

    PubMed Central

    Ogra, Pearay L.; Faden, Howard; Welliver, Robert C.

    2001-01-01

    Mucosal administration of vaccines is an important approach to the induction of appropriate immune responses to microbial and other environmental antigens in systemic sites and peripheral blood as well as in most external mucosal surfaces. The development of specific antibody- or T-cell-mediated immunologic responses and the induction of mucosally induced systemic immunologic hyporesponsiveness (oral or mucosal tolerance) depend on complex sets of immunologic events, including the nature of the antigenic stimulation of specialized lymphoid structures in the host, antigen-induced activation of different populations of regulatory T cells (Th1 versus Th2), and the expression of proinflammatory and immunoregulatory cytokines. Availability of mucosal vaccines will provide a painless approach to deliver large numbers of vaccine antigens for human immunization. Currently, an average infant will receive 20 to 25 percutaneous injections for vaccination against different childhood infections by 18 months of age. It should be possible to develop for human use effective, nonliving, recombinant, replicating, transgenic, and microbial vector- or plant-based mucosal vaccines to prevent infections. Based on the experience with many dietary antigens, it is also possible to manipulate the mucosal immune system to induce systemic tolerance against environmental, dietary, and possibly other autoantigens associated with allergic and autoimmune disorders. Mucosal immunity offers new strategies to induce protective immune responses against a variety of infectious agents. Such immunization may also provide new prophylactic or therapeutic avenues in the control of autoimmune diseases in humans. PMID:11292646

  15. Oleic acid-induced mucosal injury in developing piglet intestine.

    PubMed

    Velasquez, O R; Henninger, K; Fowler, M; Tso, P; Crissinger, K D

    1993-03-01

    A role for luminal nutrients, in particular products of lipid digestion, in the pathogenesis of mucosal injury to developing intestine has been postulated. We evaluated changes in mucosal permeability and light and electron microscopic histology induced by luminal perfusion with the long-chain fatty acid oleate in developing piglet intestine as a function of age and concentration of the fatty acid. 51Cr-labeled EDTA plasma-to-lumen clearance was measured in jejunum and ileum of 1-day-, 3-day-, 2-wk-, and 1-mo-old piglets during sequential perfusion with saline control (20 min); 0, 1, 5, and 10 mM oleic acid/10 mM taurocholate in saline (20 min); and normal saline (60 min). The jejunum of piglets < or = 2 wk showed significantly greater increases in mucosal permeability compared with 1-mo-old animals after perfusion with oleic acid. This effect was dependent on the luminal concentration of the fatty acid and was associated with mucosal injury evident under light and electron microscopy. In contrast, the overall response in ileum was more attenuated compared with jejunum. Thus oleic acid, a common dietary fatty acid, induces dose- and age-dependent injury in developing piglet intestine. Investigation of the mechanisms of this injury may provide the basis for dietary modifications directed at decreasing the risk of mucosal injury during enteral feeding in neonatal intestine.

  16. Quantitative pixelwise myocardial perfusion maps from first-pass perfusion MRI.

    PubMed

    Weng, A M; Ritter, C O; Beer, M; Hahn, D; Köstler, H

    2014-07-01

    To calculate and evaluate absolute quantitative myocardial perfusion maps from rest first-pass perfusion MRI. 10 patients after revascularization of myocardial infarction underwent cardiac rest first-pass perfusion MRI. Additionally, perfusion examinations were performed in 12 healthy volunteers. Quantitative myocardial perfusion maps were calculated by using a deconvolution technique, and results were compared were the findings of a sector-based quantification. Maps were typically calculated within 3 min per slice. For the volunteers, myocardial blood flow values of the maps were 0.51 ± 0.16 ml g(-1) per minute, whereas sector-based evaluation delivered 0.52 ± 0.15 ml g(-1) per minute. A t-test revealed no statistical difference between the two sets of values. For the patients, all perfusion defects visually detected in the dynamic perfusion series could be correctly reproduced in the maps. Calculation of quantitative perfusion maps from myocardial perfusion MRI examinations is feasible. The absolute quantitative maps provide additional information on the transmurality of perfusion defects compared with the visual evaluation of the perfusion series and offer a convenient way to present perfusion MRI findings. Voxelwise analysis of myocardial perfusion helps clinicians to assess the degree of tissue damage, and the resulting maps are a good tool to present findings to patients.

  17. Comparison of cerebral blood flow data obtained by computed tomography (CT) perfusion with that obtained by xenon CT using 320-row CT.

    PubMed

    Takahashi, Satoshi; Tanizaki, Yoshio; Kimura, Hiroaki; Akaji, Kazunori; Kano, Tadashige; Suzuki, Kentaro; Takayama, Youhei; Kanzawa, Takao; Shidoh, Satoka; Nakazawa, Masaki; Yoshida, Kazunari; Mihara, Ban

    2015-03-01

    Cerebral blood flow (CBF) data obtained by computed tomography perfusion (CTP) imaging have been shown to be qualitative data rather than quantitative, in contrast with data obtained by other imaging methods, such as xenon CT (XeCT) imaging. Thus, interpatient comparisons of CBF values themselves obtained by CTP may be inaccurate. In this study, we have compared CBF ratios as well as CBF values obtained from CTP-CBF data to those obtained from XeCT-CBF data for the same patients to determine CTP-CBF parameters that can be used for interpatient comparisons. The data used in the present study were obtained as volume data using 320-row CT. The volume data were applied to an automated region of interest-determining software (3DSRT, version 3.5.2 ) and converted to 59 slices of 2 mm interval standardized images. In the present study, we reviewed 10 patients with occlusive cerebrovascular diseases (CVDs) undergoing both CTP and XeCT in the same period. Our study shows that ratios of CBF measurements, such as hemodynamic stress distribution (perforator-to-cortical flow ratio of middle cerebral artery [MCA] region) or the left/right ratio for the region of the MCA, calculated using CTP data have been shown to correlate well with the same ratios calculated using XeCT data. These results suggest that such CBF ratios could be useful for generating interpatient comparisons of CTP-CBF data obtained by 320-row CT among patients with occlusive CVD.

  18. Meta-analysis of the independent and cumulative effects of multiple genetic modifications on pig lung xenograft performance during ex vivo perfusion with human blood.

    PubMed

    Harris, Donald G; Quinn, Kevin J; French, Beth M; Schwartz, Evan; Kang, Elizabeth; Dahi, Siamak; Phelps, Carol J; Ayares, David L; Burdorf, Lars; Azimzadeh, Agnes M; Pierson, Richard N

    2015-01-01

    Genetically modified pigs are a promising potential source of lung xenografts. Ex vivo xenoperfusion is an effective platform for testing the effect of new modifications, but typical experiments are limited by testing of a single genetic intervention and small sample sizes. The purpose of this study was to analyze the individual and aggregate effects of donor genetic modifications on porcine lung xenograft survival and injury in an extensive pig lung xenoperfusion series. Data from 157 porcine lung xenoperfusion experiments using otherwise unmodified heparinized human blood were aggregated as either continuous or dichotomous variables. Lungs were wild type in 17 perfusions (11% of the study group), while 31 lungs (20% of the study group) had one genetic modification, 40 lungs (39%) had 2, and 47 lungs (30%) had 3 or more modifications. The primary endpoint was functional lung survival to 4 h of perfusion. Secondary analyses evaluated previously identified markers associated with known lung xenograft injury mechanisms. In addition to comparison among all xenografts grouped by survival status, a subgroup analysis was performed of lungs incorporating the GalTKO.hCD46 genotype. Each increase in the number of genetic modifications was associated with additional prolongation of lung xenograft survival. Lungs that exhibited survival to 4 h generally had reduced platelet activation and thrombin generation. GalTKO and the expression of hCD46, HO-1, hCD55, or hEPCR were associated with improved survival. hTBM, HLA-E, and hCD39 were associated with no significant effect on the primary outcome. This meta-analysis of an extensive lung xenotransplantation series demonstrates that increasing the number of genetic modifications targeting known xenogeneic lung injury mechanisms is associated with incremental improvements in lung survival. While more detailed mechanistic studies are needed to explore the relationship between gene expression and pathway-specific injury and explore

  19. Study of Stress Induced Failure of the Blood-gas Barrier and the Epithelial-epithelial Cells Connections of the Lung of the Domestic Fowl, Gallus gallus Variant Domesticus after Vascular Perfusion

    PubMed Central

    Maina, John N; Jimoh, Sikiru A

    2013-01-01

    Complete blood-gas barrier breaks (BGBBs) and epithelial-epithelial cells connections breaks (E-ECCBs) were enumerated in the lungs of free range chickens, Gallus gallus variant domesticus after vascular perfusion at different pressures. The E-ECCBs surpassed the BGBBs by a factor of ~2. This showed that the former parts of the gas exchange tissue were structurally weaker or more vulnerable to failure than the latter. The differences in the numbers of BGBBs and E-ECCBs in the different regions of the lung supplied with blood by the 4 main branches of the pulmonary artery (PA) corresponded with the diameters of the blood vessels, the angles at which they bifurcated from the PA, and the positions along the PA where they branched off. Most of the BGBBs and the E-ECCBs occurred in the regions supplied by the accessory- and the caudomedial branches: the former is the narrowest branch and the first blood vessel to separate from the PA while the latter is the most direct extension of the PA and is the widest. The E-ECCBs appeared to separate and fail from tensing of the blood capillary walls, as the perfusion- and intramural pressures increased. Compared to the mammalian lungs on which data are available, i.e., those of the rabbit, the dog, and the horse, the blood-gas barrier of the lung of free range chickens appears to be substantially stronger for its thinness. PMID:25288905

  20. Validation of color Doppler ultrasonography for evaluating the uterine blood flow and perfusion during late normal pregnancy and uterine torsion in buffaloes.

    PubMed

    Hussein, Hassan A

    2013-04-15

    placentomal blood perfusion. In conclusion, depicting blood flow within the middle uterine artery using color Doppler sonography could be helpful in correct diagnosis of duration and degree of uterine torsion and concurrently predicting the viability of the fetus and dam.

  1. AUR memorial award--1988. MRI enhancement of perfused tissues using chromium labeled red blood cells as an intravascular contrast agent

    SciTech Connect

    Eisenberg, A.D.; Conturo, T.E.; Price, R.R.; Holburn, G.E.; Partain, C.L.; James, A.E. Jr. )

    1989-10-01

    It has been demonstrated that chromium (Cr) labeling significantly decreases the relaxation times of packed red blood cells (RBCs). In this study, the spin-lattice relaxation time (T1) of human red cells was shortened from 836 ms to 29 ms and the spin-spin relaxation time (T2) shortened from 134 ms to 18 ms, when the cells were labeled at a Cr incubation concentration of 50 mM. Labeling of canine cells at 50 mM resulted in a T1 of 36 ms and a T2 of 26 ms. A labeling concentration of 10 mM produced similar relaxation enhancement, with uptake of 47% of the available Cr, and was determined to be optimal. The enhancement of longitudinal and transverse relaxation rates (1/T1,-1/T2) per amount of hemoglobin-bound Cr are 6.9 s-1 mM-1 and 9.8 s-1 mM-1 respectively, different from those of a pure Cr+3 solution. Labeling cells at 10 mM decreased the survival half-time in vivo from 16.6 days to 4.7 days in dogs. No difference in red cell survival was found with the use of hetero-transfusion versus auto-transfusion of labeled RBCs. Significant shortening of the T1 (912 ms to 266 ms, P = .03) and T2 (90 ms to 70 ms, P = .006) of spleen and the T1 (764 ms to 282 ms, P = .005) and the T2 (128 ms to 86 ms, P = .005) of liver occurred when 10% of the RBC mass of dogs was exchanged with Cr labeled cells. Liver and spleen spin density changes (P greater than 0.23) and muscle spin density and relaxation changes (P greater than 0.4) were insignificant. The in vivo T1 of a canine spleen which had been infarcted did not change following transfusion with labeled cells, where the T1 of liver did shorten. We believe this preliminary study suggests that Cr labeled red cells may have the potential to become an intravascular magnetic resonance imaging contrast agent.

  2. Myocardial perfusion with rubidium-82. III. Theory relating severity of coronary stenosis to perfusion deficit

    SciTech Connect

    Mullani, N.A.

    1984-11-01

    The relation between the quantitative perfusion deficit, as measured by emission computerized tomography, and the severity of coronary artery stenosis is important for the noninvasive clinical evaluation of coronary artery disease in man. Positron emission tomography allows direct noninvasive measurement of myocardial perfusion and quantification of the size of the perfusion defect. Given this important imformation, a mathematical model has been derived to gauge the severity of a coronary stenosis from quantitative perfusion measurements in the normal and poststenotic regions of the heart. The theoretical basis is presented for relating regional myocardial perfusion and regional perfusion resistance to total, coronary blood flow and resistance at normal resting flow and during maximal coronary vasodilation. The concept of perfusion reserve is presented as a clinical measure of the severity of a stenosis.

  3. [Perfusion magnetic resonance imaging for high grade astrocytomas: Can cerebral blood volume, peak height, and percentage of signal intensity recovery distinguish between progression and pseudoprogression?].

    PubMed

    Martínez-Martínez, A; Martínez-Bosch, J

    2014-01-01

    To study the usefulness of common MRI perfusion parameters for identifying pseudoprogression in high grade astrocytomas. This retrospective case-control study compared the relative cerebral blood volume (rCBV), the relative percentage of signal intensity recovery (rPSR), and the relative peak height (rPH) recorded in a sample of 17 cases of anaplastic astrocytomas and gliomas considered to be undergoing pseudoprogression by biopsy or follow-up with those recorded in a sample of histologically similar tumors that were treated and considered to be undergoing progression by histologic study or follow-up. We evaluated the accuracy of these parameters and the correlations among them. Statistical significance was set at P<.05. The rCBV, rPSR, and rPH were significantly different between the two groups (P=.001). The cutoff values rPH=1.37, rCBV=0.9, and rPSR=99% yielded sensitivity (S)=88% and specificity (Sp)=82.2% for rPH, S=100% and Sp=100% for rCBV, and S=100% and Sp=70.6% for rPSR, respectively. We found negative correlations between rPRS and rPH (-0.76) and between rPRS and rCBV (-0.81) and a high positive correlation between rPH and rCBV (0.87). The variables rPH and rCBV were useful for differentiating between pseudoprogression and true progression in our sample. The variable rPRS was also very sensitive, although the overlap in the values between samples make it less useful a priori. Copyright © 2012 SERAM. Published by Elsevier Espana. All rights reserved.

  4. Monte Carlo estimation of scatter effects on quantitative myocardial blood flow and perfusable tissue fraction using 3D-PET and 15O-water

    NASA Astrophysics Data System (ADS)

    Hirano, Yoshiyuki; Koshino, Kazuhiro; Watabe, Hiroshi; Fukushima, Kazuhito; Iida, Hidehiro

    2012-11-01

    In clinical cardiac positron emission tomography using 15O-water, significant tracer accumulation is observed not only in the heart but also in the liver and lung, which are partially outside the field-of-view. In this work, we investigated the effects of scatter on quantitative myocardium blood flow (MBF) and perfusable tissue fraction (PTF) by a precise Monte Carlo simulation (Geant4) and a numerical human model. We assigned activities to the heart, liver, and lung of the human model with varying ratios of organ activities according to an experimental time activity curve and created dynamic sinograms. The sinogram data were reconstructed by filtered backprojection. By comparing a scatter-corrected image (SC) with a true image (TRUE), we evaluated the accuracy of the scatter correction. TRUE was reconstructed using a scatter-eliminated sinogram, which can be obtained only in simulations. A scatter-uncorrected image (W/O SC) and an attenuation-uncorrected image (W/O AC) were also constructed. Finally, we calculated MBF and PTF with a single tissue-compartment model for four types of images. As a result, scatter was corrected accurately, and MBFs derived from all types of images were consistent with the MBF obtained from TRUE. Meanwhile, the PTF of only the SC was in agreement with the PTF of TRUE. From the simulation results, we concluded that quantitative MBF is less affected by scatter and absorption in 3D-PET using 15O-water. However, scatter correction is essential for accurate PTF.

  5. Changes in pulse rate, respiratory rate, blood oxygenation, perfusion index, skin conductance, and their variability induced during and after grounding human subjects for 40 minutes.

    PubMed

    Chevalier, Gaetan

    2010-01-01

    Previous studies have shown that grounding produces quantifiable physiologic changes. This study was set up to reproduce and expand earlier electrophysiologic and physiologic parameters measured immediately after grounding with improved methodology and state-of-the-art equipment. A multiparameter double-blind experiment was conducted with 14 men and 14 women (age range: 18-80) in relatively good health. Subjects were screened for health problems using a commonly used health questionnaire. They were seated in a comfortable recliner and measured during 2-hour grounding sessions, leaving time for signals to stabilize before, during, and after grounding (40 minutes for each period). Sham 2-hour grounding sessions were also recorded with the same subjects as controls. This report presents results for 5 of the 18 parameters measured. The parameters reported here are: skin conductance (SC), blood oxygenation (BO), respiratory rate (RR), pulse rate (PR), and perfusion index (PI). This study was performed in a rented facility in Encinitas, California. The facility was chosen in a quiet area for its very low electromagnetic noise. For each session, statistical analyses were performed on four 10-minute segments: before and after grounding (sham grounding for control session) and before and after ungrounding (sham ungrounding). There was an immediate decrease in SC at grounding and an immediate increase at ungrounding on all subjects. RR increased during grounding, and the effect lasted after ungrounding. RR variance increased immediately after grounding then decreased. BO variance decreased during grounding, followed by a dramatic increase after ungrounding. PR and PI variances increased toward the end of the grounding period, and this change persisted after ungrounding. These results warrant further research to determine how grounding affects the body. Grounding could become important for relaxation, health maintenance and disease prevention.

  6. Why mucosal health?

    USDA-ARS?s Scientific Manuscript database

    Aquaculture species depend more heavily on mucosal barriers than their terrestrial agricultural counterparts as they are continuously interacting with the aquatic microbiota. Unlike classical immune centers, such as the spleen and kidney, the accessibility of mucosal surfaces through immersion/dip t...

  7. Herbs in Oral Mucositis

    PubMed Central

    Baharvand, Maryam; Jafari, Soudeh

    2017-01-01

    Oral mucositis is an inflammatory mucosal destruction as a result of chemotherapy and/or radiation therapy, which in severe cases can impair patients’ quality of life. Moreover, mucosal infection and/or systemic involvement due to compromised immunity leads to delay or discontinuation of the treatment. Many strategies and agents have been suggested for the management of this condition. Because of their lower side effects compared to chemical drugs, general interest in evaluating therapeutic effects of herbs has been increased intensively. Herbal plants apply their effect through different mechanisms of action: antioxidant, analgesic, anti-inflammatory, antifungal, antiseptic, and anticarcinogenic activity. Recently, various natural agents in plants have been noticed in mucositis, which may improve the symptoms through different interventions. The purpose of this review is to focus on the preventive or therapeutic use of herbal medicine to alleviate oral mucositis. PMID:28511530

  8. Radiation Induced Oral Mucositis

    PubMed Central

    PS, Satheesh Kumar; Balan, Anita; Sankar, Arun; Bose, Tinky

    2009-01-01

    Patients receiving radiotherapy or chemotherapy will receive some degree of oral mucositis The incidence of oral mucositis was especially high in patients: (i) With primary tumors in the oral cavity, oropharynx, or nasopharynx; (ii) who also received concomitant chemotherapy; (iii) who received a total dose over 5,000 cGy; and (iv) who were treated with altered fractionation radiation schedules. Radiation-induced oral mucositis affects the quality of life of the patients and the family concerned. The present day management of oral mucositis is mostly palliative and or supportive care. The newer guidelines are suggesting Palifermin, which is the first active mucositis drug as well as Amifostine, for radiation protection and cryotherapy. The current management should focus more on palliative measures, such as pain management, nutritional support, and maintenance, of good oral hygiene PMID:20668585

  9. Role of collateral blood flow in the apparent disparity between the extent of abnormal wall thickening and perfusion defect size during acute myocardial infarction and demand ischemia.

    PubMed

    Leong-Poi, Howard; Coggins, Matthew P; Sklenar, Jiri; Jayaweera, Ananda R; Wang, Xin-Qun; Kaul, Sanjiv

    2005-02-15

    The aim of this study was to test the hypothesis that the apparent disparity between the circumferential extent of abnormal wall thickening (WT) and that of infarct size (IS) at rest or size of ischemic zone (IZ) during demand ischemia (DI) is principally due to the effects of collateral blood flow (CollBF). A disparity has been reported between the circumferential extent of abnormal WT and that of IS at rest or IZ size during DI. Wall thickening and CollBF were measured in 18 dogs: at 6 h after coronary occlusion (Group 1, n = 6), and during 40 microg x kg x min(-1) of dobutamine in the presence of either one-vessel (Group 2, n = 6) or two-vessel stenosis (Group 3, n = 6). The apparent overestimation of the IS by the circumferential extent of abnormal WT was due to intermediate levels of CollBF in border zones within the risk area that had escaped necrosis. Although reduced, WT in these regions was commensurate with the level of flow. Similarly, during DI, regions within the IZ exhibiting the worst WT in Group 2 and 3 dogs were those not supplied by CollBF. The regions supplied by CollBF had intermediate WT, which was also commensurate with the level of flow. Only in two Group 3 dogs was tethering seen in small, normally perfused regions that were interspersed between two large IZ. Excluding these few tethered regions, data from different myocardial regions (infarcted, ischemic, CollBF dependent, and normal) were described by a single relation: y = 57(1 - e([-0.72(x - 0.06)])) (r = 0.80, p < 0.001). Myocardial regions at the margins of ischemic territories contribute to the apparent disparity between the circumferential extent of abnormal WT and IS or IZ during DI. In most circumstances, these regions are supplied by collaterals and their WT is commensurate with the degree of myocardial blood flow. The apparent disparity between the circumferential extent of WT and ischemia is rarely due to myocardial tethering, which is seen only in some instances of multi

  10. Mucosal vaccination: lung versus nose.

    PubMed

    Vujanic, Ana; Sutton, Philip; Snibson, Kenneth J; Yen, Hung-Hsun; Scheerlinck, Jean-Pierre Y

    2012-07-15

    The induction of potent mucosal immune responses able to prevent the establishment of infection at the onset of mucosal pathogen colonisation represents a desirable but challenging goal for vaccine development. Here we compare nasal vaccine delivery with intra-pulmonary vaccination using a sheep lymphatic cannulation model. Our results demonstrate that nasal delivery of a non-infective ISCOMATRIX(®) influenza vaccine does not induce primary immune responses in the lymph draining the nasal lymph nodes, suggesting that local immune responses in the lymph nodes draining the nasal cavity are relatively weak. However, this mode of delivery can boost existing immunity in the nasal lymph. Using the same adjuvant we were able to induce very potent immune responses in both blood and bronchoalveolar lavage (BAL), following intra-pulmonary delivery of ISCOMATRIX(®) influenza vaccine, even when very small doses of antigen were employed. Lung delivery could also induce comparable immune responses against other recombinant antigens mixed with ISCOMATRIX(®) adjuvant and could therefore become a method of choice for the induction of immunity to mucosal pathogens infecting the lower respiratory tract. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Combination of blood flow asymmetry in the cerebral and cerebellar hemispheres on brain perfusion SPECT predicts 5-year outcome in patients with symptomatic unilateral major cerebral artery occlusion.

    PubMed

    Nomura, Jun-ichi; Ogasawara, Kuniaki; Saito, Hideo; Terasaki, Kazunori; Matsumoto, Yoshiyasu; Takahashi, Yoshihiro; Ogasawara, Yasushi; Saura, Hiroaki; Yoshida, Koji; Sato, Yuiko; Kubo, Yoshitaka; Ogawa, Akira

    2014-03-01

    Misery perfusion increases the risk of stroke recurrence in patients with symptomatic major cerebral artery occlusion. The ratio of brain perfusion contralateral-to-affected asymmetry in the cerebellar hemisphere to brain perfusion affected-to-contralateral asymmetry in the cerebral hemisphere (CblPR/CbrPR) indicates affected-to-contralateral asymmetry of oxygen extraction fraction (OEF) in the cerebral hemisphere. The purpose of the present study was to determine whether the CblPR/CbrPR on brain perfusion single-photon emission computed tomography (SPECT) predicts 5-year outcomes in patients with symptomatic unilateral occlusion of the middle cerebral artery (MCA) or internal carotid artery (ICA). Brain perfusion was assessed using N-isopropyl-p-[123I]-iodoamphetamine (123I-IMP) SPECT in 70 patients. A region of interest (ROI) was manually placed in the bilateral MCA territories and in the bilateral cerebellar hemispheres, and the CblPR/CbrPR was calculated. All patients were prospectively followed for 5 years. The primary end points were stroke recurrence or death. A total of 17 patients exhibited the primary end points, 11 of whom experienced subsequent ipsilateral strokes. Multivariate analysis revealed that only high CblPR/CbrPR was significantly associated with the development of the primary end point or subsequent ipsilateral strokes (95% confidential limits [CIs], 1.130-3.145; P  =  0.0114 or 95% CIs, 2.558-5.140; P  =  0.0045, respectively). The CblPR/CbrPR provided 65% (11/17) or 91% (10/11) sensitivity and 88% (47/53) or 88% (52/59) specificity in predicting the primary end point or subsequent ipsilateral strokes, respectively. The CblPR/CbrPR on brain perfusion SPECT predicts 5-year outcomes in patients with symptomatic unilateral occlusion of the MCA or ICA.

  12. Mucosal and cutaneous capnometry for the assessment of tissue hypoperfusion.

    PubMed

    Mallat, Jihad; Vallet, Benoit

    2017-10-04

    In critically ill patients, tissue hypoperfusion is an important cause leading to multi- organ dysfunction and death, and it cannot always be detected by measuring standard global hemodynamic and oxygen-derived parameters. Gastric intramucosal PCO2 as measured by gastric tonometry has been recognized to be of clinical value as a prognostic factor, in assessing the effects of particular therapeutic interventions, and as an end-point of resuscitation. However, this technique has several limitations that have hampered its implementation in clinical practice. The sublingual tissue bed has been shown to be damaged in models of shock, and microcirculatory changes in this area may indicate imminent changes in other important organs. The measurement of sublingual mucosal PCO2 (PslCO2) by sublingual capnography is technically simple, noninvasive and gives near instantaneous results. Clinical studies have established that high PslCO2 values and, more especially, high PslCO2 gap (PslCO2 - arterial PCO2) values are correlated with impaired microcirculatory blood flow and a poor outcome in critically ill patients. Sublingual capnography seems to be the ideal noninvasive monitoring tool to evaluate the severity of shock states and the adequacy of tissue perfusion. However, clinical studies are needed to determine the clinical utility of PslCO2 gap monitoring as end-point target to guide resuscitation in critically ill patients.

  13. Impact of carbon dioxide tension during cardiopulmonary bypass on tissue perfusion in neonates undergoing cardiac surgery using autologous umbilical cord blood.

    PubMed

    Chasovskyi, Kyrylo; Yemets, Illya

    2016-07-01

    Previously, we reported that the oxyhemoglobin dissociation curve is shifted leftward in patients who receive autologous umbilical cord blood (UCB) during neonatal open heart surgery. In this study, we assessed whether allowing the pCO2 to rise during hypothermic cardiopulmonary perfusion would shift the curve back to the right and improve tissue oxygenation. The study population included prenatally diagnosed patients with transposition of the great arteries. The study cohort was divided into two groups and consisted of early patients originally managed with lower pCO2 levels (Group I, n=42, 2009-12) and later patients subsequently managed with higher pCO2 levels (Group II, n=38, 2012-14). Patients received similar volumes of collected autologous UCB (Group I, 80 ml; Group II, 75ml, p=0.207) with a similar mean level of HbF during CPB (Group I, 90±8%; Group II, 87±9%, p=0.310). Higher levels of pCO2 during CPB (Group I, 31 mmHg; Group II, 37 mmHg, p=0.011) resulted in a rightward shift of the oxyhemoglobin dissociation curve (increased p50O2) (Group I, 19.5±3.4 mmHg; Group II, 22.5±2.2 mmHg, p=0.011). The use of a higher pCO2 strategy was associated with decreased serum lactate during CPB (Group I, 4.7±2 mmol/l; Group II, 2.8±1.4 mmol/l, p=0.001), decreased duration of mechanical ventilation (Group I, 46h; Group II, 22h, p<0.001) and decreased of length of intensive care unit (ICU) stay (Group I, 7.6±2.6, Group II, 5.6±2.2, p=0.003) CONCLUSIONS: A higher pCO2 during CPB in neonates who underwent open heart surgery using UCB resulted in a rightward shift of the oxyhemoglobin dissociation curve and was associated with improved serum lactate levels. © The Author(s) 2015.

  14. Mucosal Health in Aquaculture

    USDA-ARS?s Scientific Manuscript database

    Abstract The mucosal surfaces (skin, gill, and intestine) constitute the first line of defense against pathogen invasion while simultaneously carrying out a diverse array of other critical physiological processes, including nutrient absorption, osmoregulation, and waste excretion. Aquaculture specie...

  15. Magnetic Resonance Perfusion Imaging in the Study of Language

    ERIC Educational Resources Information Center

    Hillis, Argye E.

    2007-01-01

    This paper provides a brief review of various uses of magnetic resonance perfusion imaging in the investigation of brain/language relationships. The reviewed studies illustrate how perfusion imaging can reveal areas of brain where dysfunction due to low blood flow is associated with specific language deficits, and where restoration of blood flow…

  16. Magnetic Resonance Perfusion Imaging in the Study of Language

    ERIC Educational Resources Information Center

    Hillis, Argye E.

    2007-01-01

    This paper provides a brief review of various uses of magnetic resonance perfusion imaging in the investigation of brain/language relationships. The reviewed studies illustrate how perfusion imaging can reveal areas of brain where dysfunction due to low blood flow is associated with specific language deficits, and where restoration of blood flow…

  17. Visceral and mucosal involvement in neonatal haemangiomatosis.

    PubMed

    Maruani, A; Piram, M; Sirinelli, D; Herbreteau, D; Saliba, E; Machet, M C; Lorette, G

    2012-10-01

    Two types of neonatal haemangiomatosis (NH) are distinguished: diffuse which is associated with a high rate of mortality linked to mucosal/visceral involvement, and benign. First, this study aimed to examine the frequency of mucosal and visceral (especially hepatic) involvement in NH, according to skin extension, and second, it aimed to examine clinical, pathological (with glucose transporter 1 (GLUT-1) immunostaining), and imaging features of NH, including follow-up data. This was a descriptive retrospective study carried out in the University Hospital Center of Tours, France. The study included 19 patients with cutaneous NH (number of skin haemangiomas ranging from 5 to >100). Mucosal involvement was observed in 32% of all cases (100% and 19% in diffuse and other cutaneous cases respectively) and hepatic involvement in 42% (67% and 38% respectively). The number of hepatic haemangiomas ranged from 1 to >10. Half of the hepatic haemangiomas cases exhibited increased hepatic arterial blood flow. Mucosal and hepatic involvement was frequent in cases with a high number of cutaneous haemangiomas (>100), but only frequency of mucosal involvement was statistically significant (P = 0.021). © 2011 The Authors. Journal of the European Academy of Dermatology and Venereology © 2011 European Academy of Dermatology and Venereology.

  18. The role of cognitive group therapy and happiness training on cerebral blood flow using 99mTc-ECD brain perfusion SPECT: a quasi-experimental study of depressed patients.

    PubMed

    Azizi, M; Bahrieniain, S A; Baghdasarians, A; Emamipur, S; Azizmohammadi, Z; Qutbi, S M; Javadi, H; Assadi, M; Asli, I N

    2014-01-01

    The purpose of this study is to investigate the impact of cognitive group therapy and happiness training objectively in the local cerebral blood flow of patients with major depression (MD). The present research is semi-experimental to pre- and post-test with a control group. Three groups were formed, and this number was incorporated in each group: 12 patients were chosen randomly; the first group of depressed patients benefited from the combination of pharmacotherapy and sessions of cognitive group therapy; the second group used a combination of pharmacotherapy and sessions of happiness training; and a third group used only pharmacotherapy. We compared cognitive-behavioural therapy and happiness training efficacy with only pharmacotherapy in MD patients. We performed brain perfusion SPECT in each group, before and after each trial. The study was conducted on 36 patients with MD (32 women and 4 men; mean age: 41.22 ± 9.08; range: 27-65 years). There were significant differences regarding the two trial effects into two experimental groups (p < 0/001) before and after trials, while such differences were not significant in the control group (p > 0.05). In addition, there was significant difference among the regional cerebral blood flow in the frontal and prefrontal regions into two experimental groups before and after trials (p < 0/001), while such differences were not significant in the control group (p > 0.05). This study demonstrated decreased cerebral perfusion in the frontal regions in MD patients, which increased following cognitive group therapy and happiness training. Because of its availability, low costs, easy performance, and the objective semi-quantitative information supplied, brain perfusion SPECT scanning might be useful to assess the diagnosis and therapy efficacy. Further exploration is needed to validate its clinical role.

  19. [An approach for comparative quantification of myocardial blood flow (O-15-H2O-PET), perfusion (Tc-99m-tetrofosmin-SPECT) and metabolism (F-18-FDG-PET)].

    PubMed

    Schäfer, W M; Nowak, B; Kaiser, H J; Block, S; Koch, K C; vom Dahl, J; Büll, U

    2001-10-01

    In the present study a new approach has been developed for comparative quantification of absolute myocardial blood flow (MBF), myocardial perfusion, and myocardial metabolism in short-axis slices. 42 patients with severe CAD, referred for myocardial viability diagnostics, were studied consecutively with 0-15-H2O PET (H2O-PET) (twice), Tc-99m-Tetrofosmin SPECT (TT-SPECT) and F-18-FDG PET (FDG-PET). All data sets were reconstructed using attenuation correction and reoriented into short axis slices. Each heart was divided into three representative slices (base, midventricular, apex) and 18 ROIs were defined on the FDG PET images and transferred to the corresponding H2O-PET and TT-SPECT slices. TT-SPECT and FDG-PET data were normalized to the ROI showing maximum perfusion. MBF was calculated for all left-ventricular ROIs using a single-compartment-model fitting the dynamic H2O-PET studies. Microsphere equivalent MBF (MBF_micr) was calculated by multiplying MBF and tissue-fraction, a parameter which was obtained by fitting the dynamic H2O-PET studies. To reduce influence of viability only well perfused areas (> 70% TT-SPECT) were used for comparative quantification. First and second mean global MBF values were 0.85 ml x min-1 x g-1 and 0.84 ml x min-1 x g-1, respectively, with a repeatability coefficient of 0.30 ml x min-1 x g-1. After sectorization mean MBF_micr was between 0.58 ml x min-1 x ml-1 and 0.68 ml x min-1 x ml-1 in well perfused areas. Corresponding TT-SPECT values ranged from 83% to 91%, and FDG-PET values from 91% to 103%. All procedures yielded higher values for the lateral than the septal regions. Comparative quantification of MBF, MBF_micr, TT-SPECT perfusion and FDG-PET metabolism can be done with the introduced method in short axis slices. The obtained values agree well with experimentally validated values of MBF and MBF_micr.

  20. In Acute Stroke, Can CT Perfusion-Derived Cerebral Blood Volume Maps Substitute for Diffusion-Weighted Imaging in Identifying the Ischemic Core?

    PubMed Central

    Copen, William A.; Morais, Livia T.; Wu, Ona; Schwamm, Lee H.; Schaefer, Pamela W.; González, R. Gilberto; Yoo, Albert J.

    2015-01-01

    Background and Purpose In the treatment of patients with suspected acute ischemic stroke, increasing evidence suggests the importance of measuring the volume of the irreversibly injured “ischemic core.” The gold standard method for doing this in the clinical setting is diffusion-weighted magnetic resonance imaging (DWI), but many authors suggest that maps of regional cerebral blood volume (CBV) derived from computed tomography perfusion imaging (CTP) can substitute for DWI. We sought to determine whether DWI and CTP-derived CBV maps are equivalent in measuring core volume. Methods 58 patients with suspected stroke underwent CTP and DWI within 6 hours of symptom onset. We measured low-CBV lesion volumes using three methods: “objective absolute,” i.e. the volume of tissue with CBV below each of six published absolute thresholds (0.9–2.5 mL/100 g), “objective relative,” whose six thresholds (51%-60%) were fractions of mean contralateral CBV, and “subjective,” in which two radiologists (R1, R2) outlined lesions subjectively. We assessed the sensitivity and specificity of each method, threshold, and radiologist in detecting infarction, and the degree to which each over- or underestimated the DWI core volume. Additionally, in the subset of 32 patients for whom follow-up CT or MRI was available, we measured the proportion of CBV- or DWI-defined core lesions that exceeded the follow-up infarct volume, and the maximum amount by which this occurred. Results DWI was positive in 72% (42/58) of patients. CBV maps’ sensitivity/specificity in identifying DWI-positive patients were 100%/0% for both objective methods with all thresholds, 43%/94% for R1, and 83%/44% for R2. Mean core overestimation was 156–699 mL for objective absolute thresholds, and 127–200 mL for objective relative thresholds. For R1 and R2, respectively, mean±SD subjective overestimation were -11±26 mL and -11±23 mL, but subjective volumes differed from DWI volumes by up to 117 and 124

  1. Effects of different types of hydroxyethyl starch (HES) on microcirculation perfusion and tissue oxygenation in patients undergoing liver surgery.

    PubMed

    Cui, Yinghua; Sun, Bo; Wang, Changsong; Liu, Shujuan; Li, Peng; Shi, Jinghui; Li, Enyou

    2014-01-01

    To compare the effects of hydroxyethyl starch (HES) 130/0.4 and HES 200/0.5, which have different molecular weights and degrees of substitution, on microcirculation perfusion and tissue oxygenation in patients undergoing liver surgery. Thirty patients with an American Society of Anesthesiologists status I/II who were scheduled for liver surgery were randomly divided into two groups: one received an intraoperative HES 130/0.4 infusion equal to the amount of blood loss (HES 130/0.4 group, n=15), and the other received HES 200/0.5 equal to the amount of blood loss (HES 200/0.5 group, n=15). Gastric mucosal perfusion and tissue oxygenation were monitored by measuring the gastric mucosal pH (pHi), which was determined using a carbon dioxide tonometer inserted through a nasogastric tube. Gastric mucosal pHi , hemodynamic parameters, body temperature, and blood gas parameters were recorded upon entering the operating room, before skin incision, one hour and two hours after skin incision, and at the end of surgery. The intraoperative pHi decreased in both groups of patients, but the decline in the HES 130/0.4 group was smaller than that of the HES 200/0.5 group. The pHi of the HES 130/0.4 group was significantly higher than that of the HES 200/0.5 group two hours after skin incision and at the end of surgery (P<0.05). A multivariate analysis showed that the type of colloid used intraoperatively was the only variant that affected pHi (F=0.626, P<0.05). Moreover, there were good correlation between pHi at the end of surgery and the length of postoperative hospital stay (r=-0.536, P<0.05) and the time intervals from surgery to the passage of flatus (r=-0.547, P<0.05). Compared with HES 200/0.5, the use of HES 130/0.4 (with a relatively lower molecular weight and lower degree of substitution) could significantly improve internal organ perfusion and tissue oxygenation in patients undergoing liver surgery with a relatively large amount of blood loss.

  2. Timing of postexercise carbohydrate-protein supplementation: roles of gastrointestinal blood flow and mucosal cell damage on gastric emptying in humans.

    PubMed

    Kashima, Hideaki; Harada, Nao; Miyamoto, Kanae; Fujimoto, Masaki; Fujita, Chiaki; Endo, Masako Yamaoka; Kobayashi, Toshio; Miura, Akira; Fukuba, Yoshiyuki

    2017-09-01

    It is well known that protein ingestion immediately after exercise greatly stimulates muscle protein synthesis during the postexercise recovery phase. However, immediately after strenuous exercise, the gastrointestinal (GI) mucosa is frequently injured by hypoperfusion in the organ/tissue, possibly resulting in impaired GI function (e.g., gastric emptying; GE). The aim of this study was to examine the effect of GI blood flow on the GE rate. Eight healthy young subjects performed an intermittent supramaximal cycling exercise for 30 min, which consisted of a 120% V̇o2peak for 20 s, followed by 20 W for 40 s. The subjects ingested 300 ml of a nutrient drink containing carbohydrate-protein at either 5 min postexercise in one trial (PE-5) or 30 min postexercise in another trial (PE-30). In the control trial (Con), the subjects ingested the same drink without exercise. The celiac artery blood flow (CABF) and superior mesenteric artery blood flow (SMABF) and GE rate were assessed by ultrasonography. Before drink ingestion in PE-5, CABF significantly decreased from baseline, whereas in PE-30, it returned to baseline. Following drink ingestion in PE-5, CABF did not change from baseline, but it significantly increased in PE-30 and Con. SMABF increased significantly later in PE-5 than in PE-30 and Con. The GE rate was consistently slower in PE-5 than in PE-30 and Con. In conclusion, the CABF response after exercise seems to modulate the subsequent GE rate and SMABF response.NEW & NOTEWORTHY A carbohydrate-protein drink was ingested at either 5 min (i.e., profoundly decreased celiac artery blood flow; CABF) or 30 min (i.e., already recovered CABF) postexercise. In the 5-min postexercise trial, the gastric emptying (GE) rate and superior mesenteric artery blood flow (SMABF) response were slower than those in the 30-min postexercise trial. The GE rate and SMABF response may be altered depending on the postexercise CABF response. Copyright © 2017 the American Physiological

  3. Experimental study on the fine structure of chicken liver parenchyme with special references to extrasinusoidal macrophages and sinusoidal blood cells. Part 2. Sinusoidal blood cells in normal and India ink perfused livers.

    PubMed

    Ohata, M; Ito, T

    1986-06-01

    Leucocytes and thrombocytes in the chicken liver sinusoids were observed under normal conditions and after intravenous India ink perfusion. The monocytes exhibited conspicuous phagocytic activity. At 30 min or earlier and 4 hr after the perfusion, they ingested considerable amounts of the carbon particles, which were deposited in small vacuoles and/or lysosomes. In this study we revealed two transitional forms of the monocyte changing into the Kupffer cell. In one transitional form, which already at 15 min after the perfusion stored considerable amounts of the particles, the ectoplasmic layer was partly differentiated and projected many pseudopodia into the sinusoid. At 48 hr after the perfusion, the other transitional form was attached by its wide basal surface to the endothelial linig and projected well-developed pseudopodia into the sinusoid like the Kupffer cell without, however, storing the carbon particles. These findings are thought to suggest the transformation of the monocytes into the Kupffer cells. Thus we came to the assumption that the Kupffer cells might be replenished: by self-proliferation; by the macrophages from the hepatic parenchyme into the sinusoid; or by transformation from the monocytes circulating into the sinusoid (the "triple origin" as opposed to the "dual origin" of the Kupffer cell). In the earliest stage after India ink perfusion, the thrombocytes exhibited the most striking reaction comparable to the Kupffer cells toward which they were assembled. The India ink particles were taken up into the "surface connected canalicular system" (SCS), which thickened and made vacuolar expansions as the amount of the particles was increased. At 4 hr after perfusion, the particles disappeared from the majority of the thrombocytes, leaving an empty SCS. The India ink particle uptake and storage by the thrombocyte were thought to be temporary phenomena, different from the true phagocytosis of the macrophages.

  4. Cytokines and mucosal immunity.

    PubMed

    Bamias, Giorgos; Arseneau, Kristen O; Cominelli, Fabio

    2014-11-01

    Cytokines are integral mediators for maintaining intestinal mucosal homeostasis, as well as prominent effector molecules during chronic gut inflammatory diseases. This review focuses on recent studies of the role of specific cytokines in mucosal immunity. Dichotomous, or even opposing, functions have been described for several cytokines involved in intestinal innate immunity (most notably for members of the interleukin-1 family), which depend on the specific inflammatory conditions within the intestinal mucosa. For example, both interleukin-1α and interleukin-33 exhibit 'alarmin'-type properties that can signal tissue or cell damage, which further add to their well described proinflammatory roles. Costimulatory molecules of the tumor necrosis factor/tumor necrosis factor receptor superfamily, such as TNF-like cytokine 1A and LIGHT, are actively involved in mucosal proinflammatory pathways, but also may exert protection against infectious agents to facilitate recovery from acute inflammation. Finally, innate lymphoid cells are increasingly recognized as important cellular sources of pivotal mucosal cytokines, including the interleukin-23/T helper 17 cytokine, interleukin-22. Elucidating the complexity of cytokine signaling within the normal mucosa and during acute and chronic inflammation will be a pivotal step toward understanding the pathogenesis of immune-mediated gut diseases and developing effective therapies to treat them.

  5. Severity assessment of pulmonary embolism using dual energy CT - correlation of a pulmonary perfusion defect score with clinical and morphological parameters of blood oxygenation and right ventricular failure.

    PubMed

    Thieme, Sven F; Ashoori, Nima; Bamberg, Fabian; Sommer, Wieland H; Johnson, Thorsten R C; Leuchte, Hanno; Becker, Alexander; Maxien, Daniel; Helck, Andreas D; Behr, Jürgen; Reiser, Maximilian F; Nikolaou, Konstantin

    2012-02-01

    To correlate a Dual Energy (DE)-based visual perfusion defect scoring system with established CT-based and clinical parameters of pulmonary embolism (PE) severity. In 63 PE patients, DE perfusion maps were visually scored for perfusion defects (P-score). Vascular obstruction was quantified using the Mastora score. Both scores were correlated with short-axis diameters of the right and left ventricle, their ratio (RV/LV ratio), width of the pulmonary trunk, a number of clinical parameters and each other. Univariate and multivariate analyses were performed. Times to generate both scores were recorded. After univariate and multivariate analysis, a significant (p < 0.05) correlation with the P-score was shown for the Mastora score (r = 0.65), RV/LV ratio (r = 0.47), width of the pulmonary trunk (r = 0.26), troponin I (r = 0.43) and PaO(2) (r = -0.50). For the left ventricular diameter, only univariate analysis showed a significant correlation. Mastora score correlated significantly with RV/LV ratio (r = 0.36), width of the pulmonary trunk (r = 0.27), PaO(2) (r = -0.41) and troponin I (r = 0.37). Mean time for generating the P-score was significantly shorter than for the Mastora score. A DE-based P-score correlates with a number of parameters of PE severity. It might be easier and faster to perform than some traditional CT scoring methods for vascular obstruction.

  6. Organic Nitrate Maintains Bone Marrow Blood Perfusion in Ovariectomized Female Rats: A Dynamic, Contrast-Enhanced Magnetic Resonance Imaging (MRI) Study

    PubMed Central

    Wang, Yi-Xiang J.; Ko, Chun Hay; Griffith, James F.; Deng, Min; Wong, Hing Lok; Gu, Tao; Huang, Yu

    2012-01-01

    This study investigated the effects of nitrate on bone mineral density (BMD) and bone marrow perfusion in ovariectomized (OVX) female rats, and also the effects of nitrate on in vitro osteoblastic activity and osteoclastic differentiation of murine monocyte/macrophage RAW 264.7 cells. Female Sprague–Dawley rats were divided into OVX + nitrate group (isosorbide-5-mononitrate, ISM, 150 mg/kg/ day b.i.d), OVX + vehicle group, and control group. Lumbar spine CT bone densitometry and perfusion MRI were performed on the rats at baseline and week 8 post-OVX. The OVX rats’ BMD decreased by 22.5% ± 5.7% at week 8 (p < 0.001); while the OVX + ISM rats’ BMD decreased by 13.1% ± 2.7% (p < 0.001). The BMD loss difference between the two groups of rats was significant (p = 0.018). The OVX rats’ lumbar vertebral perfusion MRI maximum enhancement (Emax) decreased by 10.3% ± 5.0% at week 8 (p < 0.005), while in OVX + ISM rats, the Emax increased by 5.5% ± 6.9% (p > 0.05). The proliferation of osteoblast-like UMR-106 cells increased significantly with ISM treatment at 0.78 µM to 50 μM. Treatment of UMR-106 cells with ISM also stimulated the BrdU uptake. After the RAW 264.7 cells were co-treated with osteoclastogenesis inducer RANKL and 6.25 μM ~ 100 μM of ISM for 3 days, a trend of dose-dependent increase of osteoclast number was noted. PMID:24300395

  7. Prevention of acute gastric mucosal lesions by Solcoseryl.

    PubMed

    Brzozowski, T; Radecki, T; Sendur, R; Gustaw, P; Konturek, S J

    1987-04-01

    Solcoseryl, a deproteinized extract from calf blood containing various biologically active substances, has been reported to promote the healing of skin wounds and gastric ulceration In this study, the gastroprotective effects of Solcoseryl vis-a-vis acute gastric mucosal damage were examined in rats. Solcoseryl significantly reduced the formation of acute lesions induced by intragastric application of absolute ethanol or acidified taurocholate and by water immersion and restraint stress, but failed to affect those caused by acidified aspirin. Since Solcoseryl did not offer protection in the absence of mucosal prostaglandins (PG) e.g. in aspirin-induced gastric damage, it is likely that PG may be involved in the observed gastroprotective activity of the drug. Solcoseryl failed to affect gastric acid or pepsin secretion, but increased mucosal blood flow. Thus PG generated by Solcoseryl might contribute to the maintenance of the observed mucosal microcirculation and the prevention of lesion formation by corrosive substances and stress conditions.

  8. The Mouse Isolated Perfused Kidney Technique.

    PubMed

    Czogalla, Jan; Schweda, Frank; Loffing, Johannes

    2016-11-17

    The mouse isolated perfused kidney (MIPK) is a technique for keeping a mouse kidney under ex vivo conditions perfused and functional for 1 hr. This is a prerequisite for studying the physiology of the isolated organ and for many innovative applications that may be possible in the future, including perfusion decellularization for kidney bioengineering or the administration of anti-rejection or genome-editing drugs in high doses to prime the kidney for transplantation. During the time of the perfusion, the kidney can be manipulated, renal function can be assessed, and various pharmaceuticals administered. After the procedure, the kidney can be transplanted or processed for molecular biology, biochemical analysis, or microscopy. This paper describes the perfusate and the surgical technique needed for the ex vivo perfusion of mouse kidneys. Details of the perfusion apparatus are given and data are presented showing the viability of the kidney's preparation: renal blood flow, vascular resistance, and urine data as functional, transmission electron micrographs of different nephron segments as morphological readouts, and western blots of transport proteins of different nephron segments as molecular readout.

  9. Measurement of continuous distributions of ventilation-perfusion ratios - Theory

    NASA Technical Reports Server (NTRS)

    Wagner, P. D.; Saltzman, H. A.; West, J. B.

    1974-01-01

    The resolution of the technique considered is sufficient to describe smooth distributions containing blood flow to unventilated regions (shunt), ventilation to unperfused regions (dead space), and up to three additional modes over the range of finite ventilation-perfusion ratios. In particular, areas whose ventilation-perfusion ratios are low can be separated from unventilated regions and those whose ventilation-perfusion ratios are high can similarly be distinguished from unperfused areas.

  10. Measurement of continuous distributions of ventilation-perfusion ratios - Theory

    NASA Technical Reports Server (NTRS)

    Wagner, P. D.; Saltzman, H. A.; West, J. B.

    1974-01-01

    The resolution of the technique considered is sufficient to describe smooth distributions containing blood flow to unventilated regions (shunt), ventilation to unperfused regions (dead space), and up to three additional modes over the range of finite ventilation-perfusion ratios. In particular, areas whose ventilation-perfusion ratios are low can be separated from unventilated regions and those whose ventilation-perfusion ratios are high can similarly be distinguished from unperfused areas.

  11. Temporal and concentration effects of isoflurane anaesthesia on intestinal tissue oxygenation and perfusion in horses.

    PubMed

    Hopster, K; Hopster-Iversen, C; Geburek, F; Rohn, K; Kästner, S B R

    2015-07-01

    The aim of this study was to assess the effect of duration of anaesthesia and concentration of isoflurane on global perfusion as well as intestinal microperfusion and oxygenation. Nine Warmblood horses were premedicated with xylazine; anaesthesia was induced with midazolam and ketamine, and maintained with isoflurane. Horses were ventilated to normocapnia. During 7 h of anaesthesia, mean arterial blood pressures (MAP), heart rate, central venous pressure, pulmonary artery pressure, expiratory isoflurane concentration (ETIso) and cardiac output using lithium dilution were measured; cardiac index (CI) was calculated. Intestinal microperfusion and oxygenation were measured using laser Doppler flowmetry and white-light spectrophotometry. Surface probes were placed via median laparotomy on the serosal and mucosal site of the jejunum and the pelvic flexion of the colon. After 3 h of constant ETIso (1.4%), ETIso was increased in 0.2% increments up to 2.4%, followed by a decrease to 1.2% and an increase to 1.4%. The CI and MAP decreased continuously with increasing ETIso to 40 ± 5 mL/kg/min and 52 ± 8 mmHg, respectively. Microperfusion and oxygenation remained unchanged until an ETIso of 2.0% resulted in CI and MAP of 48 ± 5 mL/kg/min and 62 ± 6 mmHg, respectively, and then decreased rapidly. When ETIso decreased back to baseline, CI, MAP, microperfusion and oxygenation recovered to baseline. Isoflurane concentration but not duration of isoflurane anaesthesia influenced central and intestinal oxygenation and perfusion in healthy horses. Under isoflurane, intestinal perfusion appeared to be preserved until a threshold MAP or blood flow was reached.

  12. Sex differences and effects of oestrogen in rat gastric mucosal defence.

    PubMed

    Shore, Richard; Björne, Håkan; Omoto, Yoko; Siemiatkowska, Anna; Gustafsson, Jan-Åke; Lindblad, Mats; Holm, Lena

    2017-01-21

    To evaluate sex differences and the effects of oestrogen administration in rat gastric mucosal defence. Sex differences in gastric mucus thickness and accumulation rate, absolute gastric mucosal blood flow using microspheres, the integrity of the gastric mucosal epithelium in response to a chemical irritant and the effects of oestrogen administration on relative gastric mucosal blood flow in an acute setting was assessed in an in vivo rat experimental model. Subsequently, sex differences in the distribution of oestrogen receptors and calcitonin gene related peptide in the gastric mucosa of animals exposed to oestrogen in the above experiments was evaluated using immunohistochemistry. The absolute blood flow in the GI-tract was generally higher in males, but only significantly different in the corpus part of the stomach (1.12 ± 0.12 mL/min•g in males and 0.51 ± 0.03 mL/min•g in females) (P = 0.002). After removal of the loosely adherent mucus layer the thickness of the firmly adherent mucus layer in males and females was 79 ± 1 µm and 80 ± 3 µm respectively. After 60 min the mucus thickness increased to 113 ± 3 µm in males and 121 ± 3 µm in females with no statistically significant difference seen between the sexes. Following oestrogen administration (0.1 followed by 1 µg/kg•min), mean blood flow in the gastric mucosa decreased by 31% [68 ± 13 perfusion units (PFU)] in males which was significantly different compared to baseline (P = 0.02). In females however, mean blood flow remained largely unchanged with a 4% (5 ± 33 PFU) reduction. The permeability of the gastric mucosa increased to a higher level in females than in males (P = 0.01) after taurocholate challenge. However, the calculated mean clearance increase did not significantly differ between the sexes [0.1 ± 0.04 to 1.1 ± 0.1 mL/min•100 g in males and 0.4 ± 0.3 to 2.1 ± 0.3 mL/min•100 g in females (P = 0.065)]. There were no significant differences between 17β-Estradiol treated

  13. Sex differences and effects of oestrogen in rat gastric mucosal defence

    PubMed Central

    Shore, Richard; Björne, Håkan; Omoto, Yoko; Siemiatkowska, Anna; Gustafsson, Jan-Åke; Lindblad, Mats; Holm, Lena

    2017-01-01

    AIM To evaluate sex differences and the effects of oestrogen administration in rat gastric mucosal defence. METHODS Sex differences in gastric mucus thickness and accumulation rate, absolute gastric mucosal blood flow using microspheres, the integrity of the gastric mucosal epithelium in response to a chemical irritant and the effects of oestrogen administration on relative gastric mucosal blood flow in an acute setting was assessed in an in vivo rat experimental model. Subsequently, sex differences in the distribution of oestrogen receptors and calcitonin gene related peptide in the gastric mucosa of animals exposed to oestrogen in the above experiments was evaluated using immunohistochemistry. RESULTS The absolute blood flow in the GI-tract was generally higher in males, but only significantly different in the corpus part of the stomach (1.12 ± 0.12 mL/min•g in males and 0.51 ± 0.03 mL/min•g in females) (P = 0.002). After removal of the loosely adherent mucus layer the thickness of the firmly adherent mucus layer in males and females was 79 ± 1 µm and 80 ± 3 µm respectively. After 60 min the mucus thickness increased to 113 ± 3 µm in males and 121 ± 3 µm in females with no statistically significant difference seen between the sexes. Following oestrogen administration (0.1 followed by 1 µg/kg•min), mean blood flow in the gastric mucosa decreased by 31% [68 ± 13 perfusion units (PFU)] in males which was significantly different compared to baseline (P = 0.02). In females however, mean blood flow remained largely unchanged with a 4% (5 ± 33 PFU) reduction. The permeability of the gastric mucosa increased to a higher level in females than in males (P = 0.01) after taurocholate challenge. However, the calculated mean clearance increase did not significantly differ between the sexes [0.1 ± 0.04 to 1.1 ± 0.1 mL/min•100 g in males and 0.4 ± 0.3 to 2.1 ± 0.3 mL/min•100 g in females (P = 0.065)]. There were no significant differences between 17

  14. Evaluation of Laser Speckle Contrast Imaging for the Assessment of Oral Mucosal Blood Flow following Periodontal Plastic Surgery: An Exploratory Study

    PubMed Central

    Molnár, Eszter; Molnár, Bálint; Lohinai, Zsolt; Tóth, Zsuzsanna; Benyó, Zoltán; Hricisák, Laszló; Windisch, Péter

    2017-01-01

    The laser speckle contrast imaging (LSCI) is proved to be a reliable tool in flap monitoring in general surgery; however, it has not been evaluated in oral surgery yet. We applied the LSCI to compare the effect of a xenogeneic collagen matrix (Geistlich Mucograft®) to connective tissue grafts (CTG) on the microcirculation of the modified coronally advanced tunnel technique (MCAT) for gingival recession coverage. Gingival microcirculation and wound fluid were measured before and after surgery for six months at twenty-seven treated teeth. In males, the flap microcirculation was restored within 3 days for both grafts followed by a hyperemic response. During the first 8 days the blood flow was higher at xenogeneic graft comparing to the CTG. In females, the ischemic period lasted for 7–12 days depending on the graft and no hyperemic response was observed. Females had more intense and prolonged wound fluid production. The LSCI method is suitable to capture the microcirculatory effect of the surgical intervention in human oral mucosa. The application of xenogeneic collagen matrices as a CTG substitute does not seem to restrain the recovery of graft bed circulation. Gender may have an effect on postoperative circulation and inflammation. PMID:28232940

  15. Evaluation of Laser Speckle Contrast Imaging for the Assessment of Oral Mucosal Blood Flow following Periodontal Plastic Surgery: An Exploratory Study.

    PubMed

    Molnár, Eszter; Molnár, Bálint; Lohinai, Zsolt; Tóth, Zsuzsanna; Benyó, Zoltán; Hricisák, Laszló; Windisch, Péter; Vág, János

    2017-01-01

    The laser speckle contrast imaging (LSCI) is proved to be a reliable tool in flap monitoring in general surgery; however, it has not been evaluated in oral surgery yet. We applied the LSCI to compare the effect of a xenogeneic collagen matrix (Geistlich Mucograft®) to connective tissue grafts (CTG) on the microcirculation of the modified coronally advanced tunnel technique (MCAT) for gingival recession coverage. Gingival microcirculation and wound fluid were measured before and after surgery for six months at twenty-seven treated teeth. In males, the flap microcirculation was restored within 3 days for both grafts followed by a hyperemic response. During the first 8 days the blood flow was higher at xenogeneic graft comparing to the CTG. In females, the ischemic period lasted for 7-12 days depending on the graft and no hyperemic response was observed. Females had more intense and prolonged wound fluid production. The LSCI method is suitable to capture the microcirculatory effect of the surgical intervention in human oral mucosa. The application of xenogeneic collagen matrices as a CTG substitute does not seem to restrain the recovery of graft bed circulation. Gender may have an effect on postoperative circulation and inflammation.

  16. Digestive physiology of the pig symposium: involvement of gut chemosensing in the regulation of mucosal barrier function and defense mechanisms.

    PubMed

    Kaji, I; Akiba, Y; Kaunitz, J D

    2013-05-01

    Meal ingestion is followed by release of numerous hormones from enteroendocrine cells interspersed among the epithelial cells lining the intestine. Recently, the de-orphanization of G protein-coupled receptor (GPCR)-type nutrient receptors, expressed on the apical membranes of enteroendocrine cells, has suggested a plausible mechanism whereby luminal nutrients trigger the release of gut hormones. Activation of nutrient receptors triggers intracellular signaling mechanisms that promote exocytosis of hormone-containing granules into the submucosal space. Hormones released by foregut enteroendocrine cells include the glucagon-like peptides (GLP) affecting glycemic control (GLP-1) and releasing pro-proliferative, hypertrophy-inducing growth factors (GLP-2). The foregut mucosa, being exposed to pulses of concentrated HCl, is protected by a system of defense mechanisms, which includes epithelial bicarbonate and mucus secretion and augmentation of mucosal blood flow. We have reported that luminal co-perfusion of AA with nucleotides in anesthetized rats releases GLP-2 into the portal vein, associated with increased bicarbonate and mucus secretion and mucosal blood flow. The GLP-2 increases bicarbonate secretion via release of vasoactive intestinal peptide (VIP) from myenteric nerves. Luminal bile acids also release gut hormones due to activation of the bile-acid receptor known as G Protein-Coupled Receptor (GPR) 131, G Protein Bile Acid Receptor (GPBAR) 1, or Takeda G Protein-Coupled Receptor (TGR) 5, also expressed on enteroendocrine cells. The GLP are metabolized by dipeptidyl peptidase IV (DPPIV), an enzyme of particular interest to pharmaceutical, because its inhibition increases plasma concentrations of GLP-1 to treat diabetes. We have also reported that DPPIV inhibition enhances the secretory effects of nutrient-evoked GLP-2. Understanding the release mechanism and the metabolic pathways of gut hormones is of potential utility to the formulation of feedstuff

  17. Blood

    MedlinePlus

    ... The liquid part, called plasma, is made of water, salts, and protein. Over half of your blood is plasma. The solid part of your blood contains red blood cells, white blood cells, and platelets. Red ...

  18. Salicylic acid analogues as chemical exchange saturation transfer MRI contrast agents for the assessment of brain perfusion territory and blood-brain barrier opening after intra-arterial infusion.

    PubMed

    Song, Xiaolei; Walczak, Piotr; He, Xiaowei; Yang, Xing; Pearl, Monica; Bulte, Jeff Wm; Pomper, Martin G; McMahon, Michael T; Janowski, Mirosław

    2016-07-01

    The blood-brain barrier (BBB) is a major obstacle for drug delivery to the brain. Predicted, focal opening of the BBB through intra-arterial infusion of hyperosmolar mannitol is feasible, but there is a need to facilitate imaging techniques (e.g. MRI) to guide interventional procedures and assess the outcomes. Here, we show that salicylic acid analogues (SAA) can depict the brain territory supplied by the catheter and detect the BBB opening, through chemical exchange saturation transfer (CEST) MRI. Hyperosmolar SAA solutions themselves are also capable of opening the BBB, and, when multiple SAA agents were co-injected, their locoregional perfusion could be differentiated. © The Author(s) 2016.

  19. Mucosal melanoma: an update.

    PubMed

    Ballester Sánchez, R; de Unamuno Bustos, B; Navarro Mira, M; Botella Estrada, R

    2015-03-01

    Mucosal melanoma is a rare melanoma subtype that differs from the cutaneous form of the tumor in its biology, clinical manifestations, and management. Diagnosis is usually late due to a lack of early or specific signs and the location of lesions in areas that are difficult to access on physical examination. Surgical excision is the treatment of choice for localized disease. The value of sentinel lymph node biopsy and lymphadenectomy is still unclear. Radiotherapy can be used as adjuvant therapy for the control of local disease. c-KIT mutations are more common than in other types of melanoma and this has led to significant advances in the use of imatinib for the treatment of metastatic mucosal melanoma. Copyright © 2014 Elsevier España, S.L.U. and AEDV. All rights reserved.

  20. Optical Microangiography: High-Definition Magnification Colonoscopy with Narrow Band Imaging (NBI) for Visualizing Mucosal Capillaries and Red Blood Cells in the Large Intestine.

    PubMed

    Yao, Kenshi; Anagnostopoulos, George K; Jawhari, Aida U; Kaye, Philip V; Hawkey, Chris J; Ragunath, Krish

    2008-06-01

    Recent advances in zoom endoscopy have enabled the subepithelial capillary network (SECN) in different organs of the gastrointestinal tract to be visualized. Ex vivo studies have suggested that the SECN demonstrates a honeycomb-like structure in the large intestine, but this has not yet been visualized in vivo. The high clarity and resolution of narrow-band imaging (NBI) may allow visualization at the single red-blood-cell (RBC) level and more accurate visualization of the SECN. We investigated whether high-definition magnification colonoscopy with NBI is useful for visualizing capillaries and RBCs in the large intestine. Sixteen patients with bowel symptoms undergoing routine colonoscopy with normal findings in a tertiary referral academic gastroenterology and endoscopy unit were included in the study. Total colonoscopies were performed using a high-definition magnification colonoscope (CF-H260AZI, Olympus, Tokyo) and a prototype high-definition electronic endoscopy system capable of NBI. Each part of the large intestine (cecum, ascending, transverse, descending, and sigmoid colon, and rectum) was observed at the maximum magnification with white-light imaging (WLI) and NBI. The normal honeycomb-like SECN and RBC movement by high-definition magnification colonoscopy with either WLI or NBI was prospectively successfully visualized for each part of the large intestine. In all subjects, high-definition magnification colonoscopy with NBI allowed the visualization of a honeycomb-like SECN together with RBC movement in each segment of the large intestine except for the rectum. In contrast, with WLI alone, neither this SECN structure nor RBC movement could be detected. High-definition magnification colonoscopy with NBI could be a new optical method for facilitating noninvasive investigations of both the microvascular architecture and microcirculation without the need for contrast materials.

  1. Simultaneous in vivo measurements of intranasal air and mucosal temperature.

    PubMed

    Wiesmiller, Kerstin; Keck, Tilman; Leiacker, Richard; Lindemann, Jörg

    2007-06-01

    Nasal cavity volume and blood temperature along the nasal airways, reflecting the mucosal temperature, are considered to be the most important predictors of nasal air conditioning. The purpose of this study was to simultaneously in vivo measure intranasal air as well as mucosal temperature for the first time. Fifteen healthy subjects were enrolled into the study. Two combined miniaturized thermocouples were used for simultaneous recording of intranasal air and mucosal temperature within the anterior turbinate area close to the head of the middle turbinate without interruption of nasal breathing. The highest air and mucosal temperature values were detected at the end of expiration, the lowest values at the end of inspiration. The difference was statistically significant (P < 0.05). The mean mucosal temperature ranged from 30.2 +/- 0.9 to 32.2 +/- 0.8 degrees C. The mean air temperature ranged from 28.5 +/- 1.2 to 34.1 +/- 0.7 degrees C. The mean differences between air and mucosal temperature were 1.7 +/- 0.5 degrees C after inspiration and 1.9 +/- 0.7 degrees C after expiration. Simultaneous measurements of intranasal air and mucosal temperature are practicable. The detected temperature gradient between air and mucosa confirm a relevant heat exchange during inspiration and expiration. This gradient between air and mucosa is obligatory for heat and water exchange to ensure adequate nasal air conditioning.

  2. The human milk oligosaccharide 2'-fucosyllactose attenuates the severity of experimental necrotising enterocolitis by enhancing mesenteric perfusion in the neonatal intestine.

    PubMed

    Good, Misty; Sodhi, Chhinder P; Yamaguchi, Yukihiro; Jia, Hongpeng; Lu, Peng; Fulton, William B; Martin, Laura Y; Prindle, Thomas; Nino, Diego F; Zhou, Qinjie; Ma, Congrong; Ozolek, John A; Buck, Rachael H; Goehring, Karen C; Hackam, David J

    2016-10-01

    Necrotising enterocolitis (NEC) is a common disease in premature infants characterised by intestinal ischaemia and necrosis. The only effective preventative strategy against NEC is the administration of breast milk, although the protective mechanisms remain unknown. We hypothesise that an abundant human milk oligosaccharide (HMO) in breast milk, 2'-fucosyllactose (2'FL), protects against NEC by enhancing intestinal mucosal blood flow, and we sought to determine the mechanisms underlying this protection. Administration of HMO-2'FL protected against NEC in neonatal wild-type mice, resulted in a decrease in pro-inflammatory markers and preserved the small intestinal mucosal architecture. These protective effects occurred via restoration of intestinal perfusion through up-regulation of the vasodilatory molecule endothelial nitric oxide synthase (eNOS), as administration of HMO-2'FL to eNOS-deficient mice or to mice that received eNOS inhibitors did not protect against NEC, and by 16S analysis HMO-2'FL affected the microbiota of the neonatal mouse gut, although these changes do not seem to be the primary mechanism of protection. Induction of eNOS by HMO-2'FL was also observed in cultured endothelial cells, providing a link between eNOS and HMO in the endothelium. These data demonstrate that HMO-2'FL protects against NEC in part through maintaining mesenteric perfusion via increased eNOS expression, and suggest that the 2'FL found in human milk may be mediating some of the protective benefits of breast milk in the clinical setting against NEC.

  3. Blood

    MedlinePlus

    ... that die or are lost from the body. White Blood Cells White blood cells (WBCs, and also ... of severe pain. previous continue Diseases of the White Blood Cells Neutropenia (pronounced: new-truh-PEE-nee- ...

  4. Field evaluation of Calypte's AWARE blood serum plasma (BSP) and oral mucosal transudate (OMT) rapid tests for detecting antibodies to HIV-1 and 2 in plasma and oral fluid.

    PubMed

    Alemnji, George A; Ngulefac, Gisele A; Ndumbe, Peter M; Asonganyi, Tazoacha

    2009-03-19

    As programs to prevent and care for HIV-infected persons are scaled-up in Africa, there is the need for continuous evaluation of the performance of test kits that could best support these programs. The present study evaluated the sensitivity, specificity, ease of use, and cost of AWARE Blood Serum Plasma (BSP) and Oral Mucosal Transudate (OMT) Rapid HIV-1/2 test kits using real-time and archived samples of HIV-infected persons from Cameroon. Matched whole blood and OMT specimens were collected prospectively from HIV-positive and HIV-negative persons from different regions of Cameroon and tested using the AWARE BSP and OMT test kits, respectively. These results were compared to the gold standard that included a combination of Determine HIV-1/2 and Enzygnost HIV-1/2. The BSP Rapid test kit was further evaluated using well characterized panels of HIV-2 and HIV-1 group O samples. Cost and end-user analysis of the OMT test kit was done by comparing its actual cost, consumables, safety, bench time and manipulation with other test kits. Of the 732 matched samples, 412 (56.3%) and 320 (43.7%) were from females and males, respectively. Of these samples, 23 (3.1%) gave discordant results between Determine HIV-1/2 and Enzygnost HIV1/2 and were excluded from the analysis. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the AWARE BSP were 100%. The AWARE OMT had 98.8% sensitivity, 98.9% specificity, 98.0% PPV and 99.4% NPV. The results of a well-characterized archived panel of HIV-2 (n=7) and HIV-1 group O (n=3) samples using the AWARE BSP Rapid test kit gave 100% concordance. Total per patient cost of the AWARE OMT rapid test kit was US dollars 4.72 compared to a mean cost of US dollars 7.33 +/- 0.11 for the other test kits. Both the AWARE BSP and OMT Rapid test kits demonstrated high sensitivities and specificities on all samples tested and were well adapted for use in resource-constrained settings with high HIV

  5. Field Evaluation of Calypte’s AWARE™ Blood Serum Plasma (BSP) and Oral Mucosal Transudate (OMT) Rapid Tests for Detecting Antibodies to HIV-1 and 2 in Plasma and Oral Fluid

    PubMed Central

    Alemnji, George A; Ngulefac, Gisele A; Ndumbe, Peter M; Asonganyi, Tazoacha

    2009-01-01

    As programs to prevent and care for HIV-infected persons are scaled-up in Africa, there is the need for continuous evaluation of the performance of test kits that could best support these programs. The present study evaluated the sensitivity, specificity, ease of use, and cost of AWARE ™ Blood Serum Plasma (BSP) and Oral Mucosal Transudate (OMT) Rapid HIV-1/2 test kits using real-time and archived samples of HIV-infected persons from Cameroon. Matched whole blood and OMT specimens were collected prospectively from HIV-positive and HIV-negative persons from different regions of Cameroon and tested using the AWARE ™ BSP and OMT test kits, respectively. These results were compared to the gold standard that included a combination of Determine HIV-1/2 and Enzygnost HIV-1/2. The BSP Rapid test kit was further evaluated using well characterized panels of HIV-2 and HIV-1 group O samples. Cost and end-user analysis of the OMT test kit was done by comparing its actual cost, consumables, safety, bench time and manipulation with other test kits. Of the 732 matched samples, 412 (56.3%) and 320 (43.7%) were from females and males, respectively. Of these samples, 23 (3.1%) gave discordant results between Determine HIV-1/2 and Enzygnost HIV1/2 and were excluded from the analysis. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the AWARE™ BSP were 100%. The AWARE™ OMT had 98.8% sensitivity, 98.9% specificity, 98.0% PPV and 99.4% NPV. The results of a well-characterized archived panel of HIV-2 (n=7) and HIV-1 group O (n=3) samples using the AWARE™ BSP Rapid test kit gave 100% concordance. Total per patient cost of the AWARE OMT rapid test kit was US$4.72 compared to a mean cost of US $7.33 ± 0.11 for the other test kits. Both the AWARE™ BSP and OMT Rapid test kits demonstrated high sensitivities and specificities on all samples tested and were well adapted for use in resource-constrained settings with high HIV

  6. 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.

  7. 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.

  8. Effects of Topical Bimatoprost 0.01% and Timolol 0.5% on Circadian IOP, Blood Pressure and Perfusion Pressure in Patients with Glaucoma or Ocular Hypertension: A Randomized, Double Masked, Placebo-Controlled Clinical Trial

    PubMed Central

    Tanga, Lucia; Berardo, Francesca; Ferrazza, Manuela; Michelessi, Manuele; Roberti, Gloria

    2015-01-01

    Purpose To compare the 24-hour (24h) effects on intraocular pressure (IOP) and cardiovascular parameters of timolol 0.5% and bimatoprost 0.01% in open angle glaucoma and ocular hypertensive subjects. Methods In this prospective, randomized, double masked, crossover, clinical trial, after washout from previous medications enrolled subjects underwent 24h IOP, blood pressure (BP) and heart rate (HR) measurements and were randomized to either topical bimatoprost 0.01% at night plus placebo in the morning or to timolol 0.5% bid. After 8 weeks of treatment a second 24h assessment of IOP, BP and HR was performed and then subjects switched to the opposite treatment for additional 8 weeks when a third 24h assessment was performed. The primary endpoint was the comparison of the mean 24h IOP after each treatment. Secondary endpoints included the comparisons of IOP at each timepoint of the 24h curve and the comparison of BP, HR, ocular perfusion pressure and tolerability. Results Mean untreated 24h IOP was 20.3 mmHg (95%CI 19.0 to 21.6). Mean 24h IOP was significantly lower after 8 weeks of treatment with bimatoprost 0.01% than after 8 weeks of treatment with timolol 0.5% bid (15.7 vs 16.8 mmHg, p = 0.0003). Mean IOP during the day hours was significantly reduced from baseline by both drugs while mean IOP during the night hours was reduced by -2.3 mmHg (p = 0.0002) by bimatoprost 0.01% plus placebo and by -1.1 mmHg by timolol 0.5% bid (p = 0.06). Timolol 0.5% significantly reduced the mean 24h systolic BP from baseline, the diastolic BP during the day hours, the HR during the night hours, and the mean 24h systolic ocular perfusion pressure. Conclusion Both Bimatoprost 0.01% and Timolol 0.5% are effective in reducing the mean 24h IOP from an untreated baseline but Bimatoprost 0.01% is more effective than timolol 0.5% throughout the 24h. Timolol 0.5% effect on IOP is reduced during the night hours and is associated with reduced BP, HR and ocular perfusion pressure. Trial

  9. Myocardial perfusion grade, myocardial salvage indices and long-term mortality in patients with acute myocardial infarction and full restoration of epicardial blood flow after primary percutaneous coronary intervention.

    PubMed

    Ndrepepa, Gjin; Mehilli, Julinda; Tiroch, Klaus; Fusaro, Massimiliano; Kufner, Sebastian; Ellert, Julia; Goedel, Julia; Schömig, Albert; Kastrati, Adnan

    2010-07-01

    The relationship between microcirculatory myocardial perfusion grade (MPG), myocardial salvage and long-term mortality after acute ST-segment elevation myocardial infarction (STEMI) and full restoration of epicardial blood flow by primary percutaneous coronary intervention (PCI) remains poorly understood. This study included 1213 patients with STEMI and Thrombolysis in Myocardial Infarction (TIMI) grade-3 flow after primary PCI. The MPG was determined and paired scintigraphic studies (before and 7-14 days after the intervention) were performed. The primary outcome was 5-year mortality. The MPG was 0-1 in 217 patients, 2 in 195, and 3 in 801. In patients with an MPG of 0-1, 2 and 3, respectively, the median infarct size was 13% (interquartile range [IQR] 5.6-28%), 12% (IQR 4-27%) and 7% (IQR 1-19%) of the left ventricle, respectively (P< .001), the myocardial salvage index (i.e. the proportion of the initial area at risk that recovered) was 0.44 (IQR 0.22-0.73), 0.46 (IQR 0.25-0.75) and 0.58 (IQR 0.31-0.85), respectively (P< .001), and the Kaplan-Meier estimated 5-year mortality was 16.6% (i.e. 28 deaths), 15.3% (i.e. 25 deaths) and 7.8% (i.e. 48 deaths), respectively. The odds ratio (OR) for death for an MPG of 0-1 vs. 3 was 2.32 (95% confidence interval [CI] 1.42-3.8; P< .001) and for an MPG of 2 vs. 3, 2.3 (95% CI 1.38-3.85; P=.001). The Cox proportional hazards model identified MPG as independently associated with mortality at 5 years: the hazard ratio for an MPG of 3 vs. 0-2 was 0.65 (95% CI 0.41-0.97; P=.037). In patients with STEMI and TIMI grade-3 flow after primary PCI, suboptimal microcirculatory myocardial perfusion (i.e. MPG < or =2) was associated with poorer myocardial salvage, a larger infarct, and higher 5-year mortality than observed in patients whose tissue perfusion was reestablished (i.e. MPG=3).

  10. Kidneys From α1,3-Galactosyltransferase Knockout/Human Heme Oxygenase-1/Human A20 Transgenic Pigs Are Protected From Rejection During Ex Vivo Perfusion With Human Blood

    PubMed Central

    Ahrens, Hellen E.; Petersen, Björn; Ramackers, Wolf; Petkov, Stoyan; Herrmann, Doris; Hauschild-Quintern, Janet; Lucas-Hahn, Andrea; Hassel, Petra; Ziegler, Maren; Baars, Wiebke; Bergmann, Sabine; Schwinzer, Reinhard; Winkler, Michael; Niemann, Heiner

    2015-01-01

    Background Multiple modifications of the porcine genome are required to prevent rejection after pig-to-primate xenotransplantation. Here, we produced pigs with a knockout of the α1,3-galactosyltransferase gene (GGTA1-KO) combined with transgenic expression of the human anti-apoptotic/anti-inflammatory molecules heme oxygenase-1 and A20, and investigated their xenoprotective properties. Methods The GGTA1-KO/human heme oxygenase-1 (hHO-1)/human A20 (hA20) transgenic pigs were produced in a stepwise approach using zinc finger nuclease vectors targeting the GGTA1 gene and a Sleeping Beauty vector coding for hA20. Two piglets were analyzed by quantitative reverse-transcription polymerase chain reaction, flow cytometry, and sequencing. The biological function of the genetic modifications was tested in a 51Chromium release assay and by ex vivo kidney perfusions with human blood. Results Disruption of the GGTA1 gene by deletion of few basepairs was demonstrated in GGTA1-KO/hHO-1/hA20 transgenic pigs. The hHO-1 and hA20 mRNA expression was confirmed by quantitative reverse-transcription polymerase chain reaction. Ex vivo perfusion of 2 transgenic kidneys was feasible for the maximum experimental time of 240 minutes without symptoms of rejection. Conclusions Results indicate that GGTA1-KO/hHO-1/hA20 transgenic pigs are a promising model to alleviate rejection and ischemia-reperfusion damage in porcine xenografts and could serve as a background for further genetic modifications toward the production of a donor pig that is clinically relevant for xenotransplantation. PMID:27500225

  11. CAD of myocardial perfusion

    NASA Astrophysics Data System (ADS)

    Storm, Corstiaan J.; Slump, Cornelis H.

    2007-03-01

    Our purpose is in the automated evaluation of the physiological relevance of lesions in coronary angiograms. We aim to extract as much as possible quantitative information about the physiological condition of the heart from standard angiographic image sequences. Coronary angiography is still the gold standard for evaluating and diagnosing coronary abnormalities as it is able to locate precisely the coronary artery lesions. The dimensions of the stenosis can be assessed nowadays successfully with image processing based Quantitative Coronary Angiography (QCA) techniques. Our purpose is to assess the clinical relevance of the pertinent stenosis. We therefore analyze the myocardial perfusion as revealed in standard angiographic image sequences. In a Region-of-Interest (ROI) on the angiogram (without an overlaying major blood vessel) the contrast is measured as a function of time (the so-called time-density curve). The required hyperemic state of exercise is induced artificially by the injection of a vasodilator drug e.g. papaverine. In order to minimize motion artifacts we select based on the recorded ECG signal end-diastolic images in both a basal and a hyperemic run in the same projection to position the ROI. We present the development of the algorithms together with results of a small study of 20 patients which have been catheterized following the standard protocol.

  12. Perfusion phantom: An efficient and reproducible method to simulate myocardial first-pass perfusion measurements with cardiovascular magnetic resonance.

    PubMed

    Chiribiri, Amedeo; Schuster, Andreas; Ishida, Masaki; Hautvast, Gilion; Zarinabad, Niloufar; Morton, Geraint; Otton, James; Plein, Sven; Breeuwer, Marcel; Batchelor, Philip; Schaeffter, Tobias; Nagel, Eike

    2013-03-01

    The aim of this article is to describe a novel hardware perfusion phantom that simulates myocardial first-pass perfusion allowing comparisons between different MR techniques and validation of the results against a true gold standard. MR perfusion images were acquired at different myocardial perfusion rates and variable doses of gadolinium and cardiac output. The system proved to be sensitive to controlled variations of myocardial perfusion rate, contrast agent dose, and cardiac output. It produced distinct signal intensity curves for perfusion rates ranging from 1 to 10 mL/mL/min. Quantification of myocardial blood flow by signal deconvolution techniques provided accurate measurements of perfusion. The phantom also proved to be very reproducible between different sessions and different operators. This novel hardware perfusion phantom system allows reliable, reproducible, and efficient simulation of myocardial first-pass MR perfusion. Direct comparison between the results of image-based quantification and reference values of flow and myocardial perfusion will allow development and validation of accurate quantification methods.

  13. Effect of spinal cord compression on local vascular blood flow and perfusion capacity by Alshareef M, Krishna V, Ferdous J, Aishareef A, Kindy M, Kolachalama VB, et al.

    PubMed Central

    Epstein, Nancy E.

    2016-01-01

    Background: Different degrees of blood flow/vascular compromise occur with anterior, posterior, or circumferential spinal cord compression/spinal cord injury (SCI). SCI is also divided into primary and secondary injury. Primary SCI refers to the original neurological damage to tissues, whereas secondary injury reflects interruption of normal blood flow leading to further inflammatory response/other local changes which contribute to additional neurological injury. Methods: The authors developed a quantitative “3-D finite element fluid structure interaction model” of spinal cord blood flow to better document the mechanisms of secondary ischemic damage occurring in the spinal cord anteriorly, posteriorly, or circumferentially. This included assessment of the anterior spinal artery (ASA) and five arterial branches (L1, L2, L3, R1, R2), but excluded the microvasculature. Results: Different locations of cord compression resulted in alternative patterns of spinal cord ischemia. Anterior spinal artery (ASA) flow was substantially reduced by direct anterior compression, but resulted in the least vascular compromise. Alternatively, posterior compression resulted in a significant and critical reduction of distal ASA blood flow and, therefore, correlated with the greatest susceptibility to acute ischemia. Counterintuitively, they concluded “at equivalent degrees of dural occlusion, the loss of branch blood flow under anterior posterior compression was intermediate to predictions for purely posterior or anterior loading.” Conclusion: Utilizing a computational three-dimensional model, Alshareef et al. observed that anterior cervical cord compression resulted in the least severe compromise of ASA blood flow to the spinal cord, whereas posterior cord compression/SCI maximally reduced distal ASA blood flow potentiating acute ischemia. Therefore, the latter warranted the earliest surgical intervention. PMID:27843686

  14. Characterization of intestinal collateral blood flow in the developing piglet.

    PubMed

    Crissinger, K D; Granger, D N

    1988-10-01

    Interest in the pathogenesis of neonatal necrotizing enterocolitis has prompted study of the intestinal circulation in developing animals. It is conceivable that poorly developed collateral channels may predispose the neonatal intestine to ischemic insults. We therefore characterized intestinal collateral blood flow in anesthetized and ventilated 1-day and 1-month-old piglets. Intestinal blood flow was measured with radioactive microspheres (15 micron diameter) before and after either 1) total occlusion of the superior mesenteric artery (SMA) or 2) occlusion of a distal (jejunoileal) branch of the SMA. After total SMA occlusion in 1-day and 1-month-old piglets, perfusion of the intestine via collaterals from the celiac and inferior mesenteric arteries was not evident. Jejunal, ileal, and colonic (except rectal) blood flows fell to zero 30 min after ligation of the SMA. Ligation of a distal branch of the SMA in 1-month-old animals significantly reduced total wall (by 25%) and mucosal/submucosal (by 25%) blood flows in the occluded segment. Similar experiments in 1-day-old piglets produced significantly greater reduction in total (70%) and mucosa/submucosa (70%) blood flows. Muscle/serosa blood flows in both groups were not significantly different from control values. In conclusion, collateral perfusion of the intestine via the celiac and inferior mesenteric arteries is insignificant during acute SMA occlusion in the developing piglet. Although there is significant collateral blood flow within the SMA vascular network, perfusion between adjacent gut segments is less effective in preventing intestinal ischemia after occlusion of a branch of the SMA in neonates than in 1-month-old piglets.

  15. Organizing a mucosal defense.

    PubMed

    Newberry, Rodney D; Lorenz, Robin G

    2005-08-01

    Gastrointestinal associated lymphoid tissue can be divided into loosely organized effector sites, which include the lamina propria and intraepithelial lymphocytes, and more organized structures, such as mesenteric lymph nodes (LNs), Peyer's patches (PPs), isolated lymphoid follicles, and cryptopatches (CPs). These organized structures in the gastrointestinal tract have been hypothesized to play the role of primary lymphoid organ, supporting the extrathymic development of T lymphocytes (CPs), secondary lymphoid organs involved in the induction of the mucosal immune response (PPs), and tertiary lymphoid structures whose function is still under debate (isolated lymphoid follicles). The most widely studied lymphoid structure found in the small intestine is the PP. PPs are secondary lymphoid structures, and their development and function have been extensively investigated. However, single lymphoid aggregates resembling PPs have been also described in humans and in the murine small intestines. These isolated lymphoid follicles have both germinal centers and an overlying follicle-associated epithelium, suggesting that they also can function as inductive sites for the mucosal immune response. This review compares and contrasts the development and function of the four main organized gastrointestinal lymphoid tissues: CPs, isolated lymphoid follicles, PPs, and mesenteric LNs.

  16. Mucosal biofilms of Candida albicans.

    PubMed

    Ganguly, Shantanu; Mitchell, Aaron P

    2011-08-01

    Biofilms are microbial communities that form on surfaces and are embedded in an extracellular matrix. C. albicans forms pathogenic mucosal biofilms that are evoked by changes in host immunity or mucosal ecology. Mucosal surfaces are inhabited by many microbial species; hence these biofilms are polymicrobial. Several recent studies have applied paradigms of biofilm analysis to study mucosal C. albicans infections. These studies reveal that the Bcr1 transcription factor is a master regulator of C. albicans biofilm formation under diverse conditions, though the most relevant Bcr1 target genes can vary with the biofilm niche. An important determinant of mucosal biofilm formation is the interaction with host defenses. Finally, studies of interactions between bacterial species and C. albicans provide insight into the communication mechanisms that endow polymicrobial biofilms with unique properties.

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

    PubMed

    Othman, Ahmed E; Afat, Saif; Nikoubashman, Omid; Müller, Marguerite; Schubert, Gerrit Alexander; Bier, Georg; Brockmann, Marc A; Wiesmann, Martin; Brockmann, Carolin

    2016-08-01

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

  18. Imaging of myocardial perfusion with magnetic resonance.

    PubMed

    Barkhausen, Jörg; Hunold, Peter; Jochims, Markus; Debatin, Jörg F

    2004-06-01

    Coronary artery disease (CAD) is currently the leading cause of death in developed nations. Reflecting the complexity of cardiac function and morphology, noninvasive diagnosis of CAD represents a major challenge for medical imaging. Although coronary artery stenoses can be depicted with magnetic resonance (MR) and computed tomography (CT) techniques, its functional or hemodynamic impact frequently remains elusive. Therefore, there is growing interest in other, target organ-specific parameters such as myocardial function at stress and first-pass myocardial perfusion imaging to assess myocardial blood flow. This review explores the pathophysiologic background, recent technical developments, and current clinical status of first-pass MR imaging (MRI) of myocardial perfusion.

  19. Effect of carbachol on intestinal mucosal blood flow, activity of Na+-K+-ATPase, expression of aquaporin-1, and intestinal absorption rate during enteral resuscitation of burn shock in rats.

    PubMed

    Bao, Chengmei; Hu, Sen; Zhou, Guoyong; Tian, Yijun; Wu, Yan; Sheng, Zhiyong

    2010-01-01

    We investigated the effect of carbachol (CAR, a cholinergic agent) on intestinal mucosal blood flow (IMBF), activity of Na-K-ATPase, expression of aquaporin (AQP)-1, and intestinal absorption rate during enteral resuscitation of a 35%TBSA scald in rats with a glucose electrolyte solution (GES). One hundred male Wistar rats were randomly divided into five groups: sham scald (N group); scald without fluid resuscitation (S group); scald resuscitated with enteral GES alone (GES group); scald resuscitated with enteral CAR alone (CAR group); and scald resuscitated with enteral CAR plus GES (GES/CAR group). The rats were inflicted 35%TBSA third degree of scald injury on the back with boiling water (100 degrees C, 15 seconds) in all groups, except the sham scald group. A catheter was inserted into the proximal duodenum (5 cm distal to pylorus) and distal ileum (5 cm proximal to cecum), of each rats through laparotomy, thus a segment of intestine was virtually isolated to form a loop for inlet and outlet of introduced fluid. In N, GES, and GES/CAR groups, fluids were introduced 30 minutes after scald injury. The speed of fluid infusion was 4 ml/kg/1%TBSA for 4 hours. CAR (60 microg/kg) was injected into the intestinal lumen at 30-minute after injury in CAR and GES/CAR groups. At 2 and 4 hours after scald, intestinal absorption rate of water and Na, and IMBF were determined, respectively. Then, animals were killed, and specimens of intestinal tissue were obtained for the determination of the activity of Na-K-ATPase, hematoxylin-eosin coloring, and expression of AQP-1. The intestinal absorption rate was reduced markedly in GES group compared with sham scald group at 2 and 4 hours after scald, and absorption rate of small intestine in GES/CAR was significantly higher than that in GES group (P < .05). It was also found that there was significant decrease in IMBF, activity of Na-K-ATPase, and expression of AQP-1 in scald group compared with the sham group. However, in GES

  20. Abdominal perfusion computed tomography.

    PubMed

    Ogul, Hayri; Bayraktutan, Ummugulsum; Kizrak, Yesim; Pirimoglu, Berhan; Yuceler, Zeynep; Sagsoz, M Erdem; Yilmaz, Omer; Aydinli, Bulent; Ozturk, Gurkan; Kantarci, Mecit

    2013-02-01

    The purpose of this article is to provide an up to date review on the spectrum of applications of perfusion computed tomography (CT) in the abdomen. New imaging techniques have been developed with the objective of obtaining a structural and functional analysis of different organs. Recently, perfusion CT has aroused the interest of many researchers who are studying the applicability of imaging modalities in the evaluation of abdominal organs and diseases. Per-fusion CT enables fast, non-invasive imaging of the tumor vascular physiology. Moreover, it can act as an in vivo biomarker of tumor-related angiogenesis.

  1. Abdominal Perfusion Computed Tomography

    PubMed Central

    Ogul, Hayri; Bayraktutan, Ummugulsum; Kizrak, Yesim; Pirimoglu, Berhan; Yuceler, Zeynep; Sagsoz, M. Erdem; Yilmaz, Omer; Aydinli, Bulent; Ozturk, Gurkan; Kantarci, Mecit

    2013-01-01

    The purpose of this article is to provide an up to date review on the spectrum of applications of perfusion computed tomography (CT) in the abdomen. New imaging techniques have been developed with the objective of obtaining a structural and functional analysis of different organs. Recently, perfusion CT has aroused the interest of many researchers who are studying the applicability of imaging modalities in the evaluation of abdominal organs and diseases. Per-fusion CT enables fast, non-invasive imaging of the tumor vascular physiology. Moreover, it can act as an in vivo biomarker of tumor-related angiogenesis. PMID:25610249

  2. Sodium alginate inhibits methotrexate-induced gastrointestinal mucositis in rats.

    PubMed

    Yamamoto, Atsuki; Itoh, Tomokazu; Nasu, Reishi; Kajiwara, Eiji; Nishida, Ryuichi

    2013-01-01

    Gastrointestinal mucositis is one of the most prevalent side effects of chemotherapy. Methotrexate is a pro-oxidant compound that depletes dihydrofolate pools and is widely used in the treatment of leukemia and other malignancies. Through its effects on normal tissues with high rates of proliferation, methotrexate treatment leads to gastrointestinal mucositis. In rats, methotrexate-induced gastrointestinal mucositis is histologically characterized by crypt loss, callus fusion and atrophy, capillary dilatation, and infiltration of mixed inflammatory cells. The water-soluble dietary fiber sodium alginate (AL-Na) is derived from seaweed and has demonstrated muco-protective and hemostatic effects on upper gastrointestinal ulcers. In the present study, we evaluated the effects of AL-Na on methotrexate-induced small intestinal mucositis in rats. Animals were subcutaneously administered methotrexate at a dosage of 2.5 mg/kg once daily for 3 d. Rats were treated with single oral doses of AL-Na 30 min before and 6 h after methotrexate administration. On the 4th day, small intestines were removed and weighed. Subsequently, tissues were stained with hematoxylin-eosin and bromodeoxyuridine. AL-Na significantly prevented methotrexate-induced small intestinal mucositis. Moreover, AL-Na prevented decreases in red blood cell numbers, hemoglobin levels, and hematocrit levels. These results suggest the potential of AL-Na as a therapy for methotrexate-induced small intestinal mucositis.

  3. Oral mucositis in children suffering from acute lymphoblastic leukaemia.

    PubMed

    Pels, Elżbieta

    2012-01-01

    Oral mucositis is the most commonly reported side effect observed in neoplastic patients treated with chemotherapy and radiotherapy of the head and neck region as well as in patients who have received a haematopoietic stem cell transplant. The aim of the study was to assess the oral mucosa status in children with acute lymphoblastic leukaemia (ALL) during antineoplastic therapy. The clinical examination included 78 children aged 2-18 with ALL. The clinical examination was conducted using the dental preset tray. The condition of the oral mucosa was determined using the WHO scale for oral mucositis. In the first period of antineoplastic therapy the pathological lesions of the oral mucosa of the mucositis type were observed among the examined patients. The lesions had various levels of intensity. Pain was found to be the primary symptom of oral mucositis. In this study the following were observed: local erythema of the oral mucosa in 35%, white pseudomembranous lesions in 18%, erosions in 40% and oral ulcerative lesions in 4% of patients who underwent the antineoplastic therapy. Oral mucositis was observed in 3.17% of children after 6 months of chemotherapy. Local treatment of oral mucositis with polyantibiotic-antifungal mixture, supporting antifungal systemic treatment, and improving the overall peripheral blood conditions in children suffering from acute lymphoblastic leukaemia improve the condition of the oral mucosa.

  4. Berberine Reduces Uremia-Associated Intestinal Mucosal Barrier Damage.

    PubMed

    Yu, Chao; Tan, Shanjun; Zhou, Chunyu; Zhu, Cuilin; Kang, Xin; Liu, Shuai; Zhao, Shuang; Fan, Shulin; Yu, Zhen; Peng, Ai; Wang, Zhen

    2016-11-01

    Berberine is one of the main active constituents of Rhizoma coptidis, a traditional Chinese medicine, and has long been used for the treatment of gastrointestinal disorders. The present study was designed to investigate the effects of berberine on the intestinal mucosal barrier damage in a rat uremia model induced by the 5/6 kidney resection. Beginning at postoperative week 4, the uremia rats were treated with daily 150 mg/kg berberine by oral gavage for 6 weeks. To assess the intestinal mucosal barrier changes, blood samples were collected for measuring the serum D-lactate level, and terminal ileum tissue samples were used for analyses of intestinal permeability, myeloperoxidase activity, histopathology, malondialdehyde (MDA) level, and superoxide dismutase (SOD) activity. Berberine treatment resulted in significant decreases in the serum D-lactate level, intestinal permeability, intestinal myeloperoxidase activity, and intestinal mucosal and submucosal edema and inflammation, and the Chiu's scores assessed for intestinal mucosal injury. The intestinal MDA level was reduced and the intestinal SOD activity was increased following berberine treatment. In conclusion, berberine reduces intestinal mucosal barrier damage induced by uremia, which is most likely due to its anti-oxidative activity. It may be developed as a potential treatment for preserving intestinal mucosal barrier function in patients with uremia.

  5. Oral mucositis in children suffering from acute lymphoblastic leukaemia

    PubMed Central

    2012-01-01

    Aim of the study Oral mucositis is the most commonly reported side effect observed in neoplastic patients treated with chemotherapy and radiotherapy of the head and neck region as well as in patients who have received a haematopoietic stem cell transplant. The aim of the study was to assess the oral mucosa status in children with acute lymphoblastic leukaemia (ALL) during antineoplastic therapy. Material and methods The clinical examination included 78 children aged 2-18 with ALL. The clinical examination was conducted using the dental preset tray. The condition of the oral mucosa was determined using the WHO scale for oral mucositis. Results In the first period of antineoplastic therapy the pathological lesions of the oral mucosa of the mucositis type were observed among the examined patients. The lesions had various levels of intensity. Pain was found to be the primary symptom of oral mucositis. In this study the following were observed: local erythema of the oral mucosa in 35%, white pseudomembranous lesions in 18%, erosions in 40% and oral ulcerative lesions in 4% of patients who underwent the antineoplastic therapy. Oral mucositis was observed in 3.17% of children after 6 months of chemotherapy. Conclusion Local treatment of oral mucositis with polyantibiotic-antifungal mixture, supporting antifungal systemic treatment, and improving the overall peripheral blood conditions in children suffering from acute lymphoblastic leukaemia improve the condition of the oral mucosa. PMID:23788849

  6. Variability in quantitative cardiac magnetic resonance perfusion analysis

    PubMed Central

    Bratis, K.

    2013-01-01

    By taking advantage of its high spatial resolution, noninvasive and nontoxic nature first-pass perfusion cardiovascular magnetic resonance (CMR) has rendered an indispensable tool for the noninvasive detection of reversible myocardial ischemia. A potential advantage of perfusion CMR is its ability to quantitatively assess perfusion reserve within a myocardial segment, as expressed semi- quantitatively by myocardial perfusion reserve index (MPRI) and fully- quantitatively by absolute myocardial blood flow (MBF). In contrast to the high accuracy and reliability of CMR in evaluating cardiac function and volumes, perfusion CMR is adversely affected by multiple potential reasons during data acquisition as well as post-processing. Various image acquisition techniques, various contrast agents and doses as well as variable blood flow at rest as well as variable reactions to stress all influence the acquired data. Mechanisms underlying the variability in perfusion CMR post processing, as well as their clinical significance, are yet to be fully elucidated. The development of a universal, reproducible, accurate and easily applicable tool in CMR perfusion analysis remains a challenge and will substantially enforce the role of perfusion CMR in improving clinical care. PMID:23825774

  7. Hypersensitivity to acid is associated with impaired esophageal mucosal integrity in patients with gastroesophageal reflux disease with and without esophagitis.

    PubMed

    Weijenborg, Pim W; Smout, André J P M; Verseijden, Caroline; van Veen, Henk A; Verheij, Joanne; de Jonge, Wouter J; Bredenoord, Albert J

    2014-08-01

    Increased esophageal sensitivity and impaired mucosal integrity have both been described in patients with gastroesophageal reflux disease, but the relationship between hypersensitivity and mucosal integrity is unclear. The aim of the present study was to investigate acid sensitivity in patients with erosive and nonerosive reflux disease and control subjects to determine the relation with functional esophageal mucosal integrity changes as well as to investigate cellular mechanisms of impaired mucosal integrity in these patients. In this prospective experimental study, 12 patients with nonerosive reflux disease, 12 patients with esophagitis grade A or B, and 11 healthy control subjects underwent an acid perfusion test and upper endoscopy. Mucosal integrity was measured during endoscopy by electrical tissue impedance spectroscopy and biopsy specimens were analyzed in Ussing chambers for transepithelial electrical resistance, transepithelial permeability and gene expression of tight junction proteins and filaggrin. Patients with nonerosive reflux disease and esophagitis were more sensitive to acid perfusion compared with control subjects, having a shorter time to perception of heartburn and higher perceived intensity of heartburn. In reflux patients, enhanced acid sensitivity was associated with impairment of in vivo and vitro esophageal mucosal integrity. Mucosal integrity was significantly impaired in patients with esophagitis, displaying higher transepithelial permeability and lower extracellular impedance. Although no significant differences in the expression of tight junction proteins were found in biopsies among patient groups, mucosal integrity parameters in reflux patients correlated negatively with the expression of filaggrin. In conclusion, sensitivity to acid is enhanced in patients with gastroesophageal reflux disease, irrespective of the presence of erosions, and is associated with impaired esophageal mucosal integrity. Mucosal integrity of the esophagus

  8. 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

  9. Canine gastric mucosal vasodilation with prostaglandins and histamine analogs

    SciTech Connect

    Gerber, J.G.; Nies, A.S.

    1982-10-01

    The effect of direct intragastric artery infusion of prostaglandins E2 and I2, arachidonic acid, dimaprit (histamine H2 agonist), and 2',2'-pyridylethylamine (histamine H1 agonist) on gastric mucosal blood flow was examined in dogs to elucidate the relationship between gastric secretory state and mucosal blood flow in dogs. These compounds were chosen because of their diverse effect on gastric acid secretion. Gastric fundus blood flow was measured both electromagnetically with a flow probe around the left gastric artery which supplies the fundus almost exclusively, and by the radioactive microsphere technique. Intraarterial infusion of all the compounds resulted in gastric mucosal vasodilation even though PGE2, PGI2, and arachidonic acid inhibit gastric acid secretion, dimaprit stimulated gastric acid secretion, and 2',2'-pyridylethylamine does not affect gastric acid secretion. There was total agreement in the blood flow measurements by the two different techniques. Our data suggest that gastric acid secretion and gastric vasodilation are independently regulated. In addition, the validity of the studies in which the aminopyrine clearance indicates that prostaglandins are mucosal vasoconstrictors needs to be questioned because of the reliance of those measurements on the secretory state of the stomach.

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

    PubMed

    Lum, Mark A; Martin, Alastair J; Alexander, Matthew D; McCoy, David B; Cooke, Daniel L; Lillaney, Prasheel; Moftakhar, Parham; Amans, Matthew R; Settecase, Fabio; Nicholson, Andrew; Dowd, Christopher F; Halbach, Van V; Higashida, Randall T; McDermott, Michael W; Saloner, David; Hetts, Steven W

    2016-01-01

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

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

    PubMed Central

    Martin, Alastair J.; Alexander, Matthew D.; McCoy, David B.; Cooke, Daniel L.; Lillaney, Prasheel; Moftakhar, Parham; Amans, Matthew R.; Settecase, Fabio; Nicholson, Andrew; Dowd, Christopher F.; Halbach, Van V.; Higashida, Randall T.; McDermott, Michael W.; Saloner, David; Hetts, Steven W.

    2016-01-01

    Background and Purpose To evaluate the ability of IA MR perfusion to characterize meningioma blood supply. Methods Studies were performed in a suite comprised of an x-ray angiography unit and 1.5T MR scanner that permitted intraprocedural patient movement between the imaging modalities. Patients underwent intra-arterial (IA) and intravenous (IV) T2* dynamic susceptibility MR perfusion immediately prior to meningioma embolization. Regional tumor arterial supply was characterized by digital subtraction angiography and classified as external carotid artery (ECA) dural, internal carotid artery (ICA) dural, or pial. MR perfusion data regions of interest (ROIs) were analyzed in regions with different vascular supply to extract peak height, full-width at half-maximum (FWHM), relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and mean transit time (MTT). Linear mixed modeling was used to identify perfusion curve parameter differences for each ROI for IA and IV MR imaging techniques. IA vs. IV perfusion parameters were also directly compared for each ROI using linear mixed modeling. Results 18 ROIs were analyzed in 12 patients. Arterial supply was identified as ECA dural (n = 11), ICA dural (n = 4), or pial (n = 3). FWHM, rCBV, and rCBF showed statistically significant differences between ROIs for IA MR perfusion. Peak Height and FWHM showed statistically significant differences between ROIs for IV MR perfusion. RCBV and MTT were significantly lower for IA perfusion in the Dural ECA compared to IV perfusion. Relative CBF in IA MR was found to be significantly higher in the Dural ICA region and MTT significantly lower compared to IV perfusion. PMID:27802268

  12. Myocardial perfusion as an indicator of graft patency after coronary artery bypass surgery. [Thallium 201

    SciTech Connect

    Kolibash, A.J.; Call, T.D.; Bush, C.A.; Tetalman, M.R.; Lewis, R.P.

    1980-05-01

    Stress and resting myocardial perfusion were assessed in 38 patients who received 96 grafts. Stress perfusion was evaluated with thallium-201 and resting myocardial blood flow distribution with radiolabeled particles. When both stress and rest perfusion were normal, graft patency was 82% (51 of 62 grafts). Graft patency was also high (81%, 13 of 16) in areas where stress perfusion abnormalities resolved or become less apparent at rest. However, when stress perfusion defects remained unchanged at rest, the graf was likely to be occuluded (73%, 11 of 15). Maintenance of normal rest perfusion or improvement of rest perfusion postoperatively was also associated with a high graft patency rate (80%, 35 of 44), whereas the development of new rest perfusion defects postoperatively implied graft occlusion (86%, six of seven).

  13. Pancreatic perfusion and subsequent response to glucose in healthy individuals and patients with type 1 diabetes.

    PubMed

    Carlbom, Lina; Espes, Daniel; Lubberink, Mark; Eriksson, Olof; Johansson, Lars; Jansson, Leif; Korsgren, Olle; Ahlström, Håkan; Carlsson, Per-Ola

    2016-09-01

    The aim of this study was to investigate pancreatic perfusion and its response to a glucose load in patients with type 1 diabetes mellitus compared with non-diabetic ('healthy') individuals. Eight individuals with longstanding type 1 diabetes and ten sex-, age- and BMI-matched healthy controls underwent dynamic positron emission tomography scanning with (15)O-labelled water before and after intravenous administration of glucose. Perfusion in the pancreas was measured. Portal and arterial hepatic perfusion were recorded as references. Under fasting conditions, total pancreatic perfusion was on average 23% lower in the individuals with diabetes compared with healthy individuals. Glucose increased total pancreatic and portal hepatic blood perfusion in healthy individuals by 48% and 38%, respectively. In individuals with diabetes there was no significant increase in either total pancreatic or portal hepatic perfusion. Individuals with type 1 diabetes have reduced basal pancreatic perfusion and a severely impaired pancreatic and splanchnic perfusion response to intravenous glucose stimulation.

  14. Evaluation of the effect of elevated intraocular pressure and reduced ocular perfusion pressure on retinal capillary bed filling and total retinal blood flow in rats by OMAG/OCT.

    PubMed

    Zhi, Zhongwei; Cepurna, William; Johnson, Elaine; Jayaram, Hari; Morrison, John; Wang, Ruikang K

    2015-09-01

    To determine if retinal capillary filling is preserved in the face of acutely elevated intraocular pressure (IOP) in anesthetized rats, despite a reduction in total retinal blood flow (RBF), using optical microangiography/optical coherence tomography (OMAG/OCT). OMAG provided the capability of depth-resolved imaging of the retinal microvasculature down to the capillary level. Doppler OCT was applied to measure the total RBF using an enface integration approach. The microvascular pattern, capillary density, and total RBF were monitored in vivo as the IOP was increased from 10 to 100mmHg in 10mmHg intervals and returned back to 10mmHg. In animals with mean arterial pressure (MAP) of 102±4mmHg (n=10), when IOP was increased from 0 to 100mmHg, the capillary density remained at or above 80% of baseline for the IOP up to 60mmHg [or ocular perfusion pressure (OPP) at 40mmHg]. This was then decreased, achieving 60% of baseline at IOP 70mmHg and OPP of 30mmHg. Total RBF was unaffected by moderate increases in IOP up to 30mmHg, beyond which total RBF decreased linearly, reaching 50% of baseline at IOP 60mmHg and OPP 40mmHg. Both capillary density and total RBF were totally extinguished at 100mmHg, but fully recovered when IOP returned to baseline. By comparison, a separate group of animals with lower MAP (mean=75±6mmHg, n=7) demonstrated comparable decreases in both capillary filling and total RBF at IOPs that were 20mmHg lower than in the initial group. Both were totally extinguished at 80mmHg, but fully recovered when IOP returned to baseline. Relationships of both parameters to OPP were unchanged. Retinal capillary filling and total RBF responses to IOP elevation can be monitored non-invasively by OMAG/OCT and both are influenced by OPP. Retinal capillary filling was relatively preserved down to a perfusion pressure of 40mmHg, despite a linear reduction in total RBF. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Mucosal vaccines: the promise and the challenge.

    PubMed

    Neutra, Marian R; Kozlowski, Pamela A

    2006-02-01

    Most infectious agents enter the body at mucosal surfaces and therefore mucosal immune responses function as a first line of defence. Protective mucosal immune responses are most effectively induced by mucosal immunization through oral, nasal, rectal or vaginal routes, but the vast majority of vaccines in use today are administered by injection. As discussed in this Review, current research is providing new insights into the function of mucosal tissues and the interplay of innate and adaptive immune responses that results in immune protection at mucosal surfaces. These advances promise to accelerate the development and testing of new mucosal vaccines against many human diseases including HIV/AIDS.

  16. Gastroduodenal Mucosal Defense Mechanisms

    PubMed Central

    Said, Hyder; Kaji, Izumi; Kaunitz, Jonathan D.

    2015-01-01

    Purpose of Review To highlight recent developments in the field of gastroduodenal mucosal defense with emphasis on lumen-gut interactions. Recent Findings There has been a growing interest in the physiological functions of luminal chemosensors present from tongue to colon that detect organic molecules in the luminal content associated with nutrient ingestion, usually associated with specialized cells, in particular the enteroendocrine cells. These receptors transduce the release of peptide hormones, in particular proglucagon-derived products such as the glucagon-like-peptides (GLPs), which have profound effects on gut function and on metabolism. Luminal chemosensors transduce GLP release in response to changes in the cellular environment, as part of the mechanism of nutrient chemosensing. GLP-2 has important trophic effects on the intestinal mucosa, including increasing the proliferation rate of stem cells and reducing transmucosal permeability to ions and small molecules, in addition to increasing the rate of duodenal bicarbonate secretion. GLP-1, although traditionally considered an incretin that enhances the effect of insulin on peripheral tissues, also has trophic effects on the intestinal epithelium. Summary A better understanding of the mechanisms that mediate GLP release can further illuminate the importance of nutrient chemosensing as an important component of the mechanism that mediates the trophic effects of luminal nutrients. GLP-1 and -2 are already in clinical use for the treatment of diabetes and intestinal failure. Improved understanding of the control of their release and their end-organ effects will identify new clinical indications and interventions that enhance their release. PMID:26376476

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

    PubMed

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

    2016-02-01

    The objective of this study was to observe the change in blood perfusion of liver cancer following argon-helium knife treatment with functional computer tomography perfusion imaging. Twenty-seven patients with primary liver cancer treated with argon-helium knife and were included in this study. Plain computer tomography (CT) and computer tomography perfusion (CTP) imaging were conducted in all patients before and after treatment. Perfusion parameters including blood flows, blood volume, hepatic artery perfusion fraction, hepatic artery perfusion, and hepatic portal venous perfusion were used for evaluating therapeutic effect. All parameters in liver cancer were significantly decreased after argon-helium knife treatment (p < 0.05 to all). Significant decrease in hepatic artery perfusion was also observed in pericancerous liver tissue, but other parameters kept constant. CT perfusion imaging is able to detect decrease in blood perfusion of liver cancer post-argon-helium knife therapy. Therefore, CTP imaging would play an important role for liver cancer management followed argon-helium knife therapy.

  18. Treatment of Oral Mucositis in Hematologic Patients Undergoing Autologous or Allogeneic Transplantation of Peripheral Blood Stem Cells: a Prospective, Randomized Study with a Mouthwash Containing Camelia Sinensis Leaf Extract

    PubMed Central

    Carulli, Giovanni; Rocco, Melania; Panichi, Alessia; Chios, Chiara Feira; Ciurli, Ester; Mannucci, Chiara; Sordi, Elisabetta; Caracciolo, Francesco; Papineschi, Federico; Benedetti, Edoardo; Petrini, Mario

    2013-01-01

    Oral mucositis is an important side effect of hematopoietic stem cell transplantation (HCST), mainly due to toxicity of conditioning regimens. It produces significant pain and morbidity. The present study reports a prospective, randomized, non-blinded study testing the efficacy of a new mouthwash, called Baxidil Onco® (Sanitas Farmaceutici Srl, Tortona, Italy) in 60 hematologic patients undergoing HCST (28 autologous, 32 allogeneic). Baxidil Onco®, used three times a day from Day -1 to Day +30, in addition to standard prophylactic schedules, was administered to 14 patients undergoing autologous and 14 patients undergoing allogeneic HCST. The remaining 32 patients (14 autologous and 18 HCST) were treated only with standard prophylactic schedules and served as control. In our study, the overall incidence of oral mucositis, measured according to the World Health Organization 0-4 scale, was 50% in the Baxidl Onco® group versus 82% in the control group (P=0.022). In addition, a significant reduction in scale 2-4 oral mucositis was observed in the Baxidil Onco® group (25% vs 56.2%; P=0.0029). The results obtained indicate that incidence, severity and duration of oral mucositis induced by conditioning regimens for HCST can be significantly reduced by oral rinsing with Baxidil Onco®, in addition to the standard prophylaxis scheme. Since Camelia Sinensin extract, which is used to produce green tea, is the main agent in this mouthwash, we hypothesize that the anti-oxidative properties of polyphenolic compounds of tea might exert protective effects on oral mucosa. PMID:23888242

  19. Maximal perfusion of skeletal muscle in man.

    PubMed Central

    Andersen, P; Saltin, B

    1985-01-01

    Five subjects exercised with the knee extensor of one limb at work loads ranging from 10 to 60 W. Measurements of pulmonary oxygen uptake, heart rate, leg blood flow, blood pressure and femoral arterial-venous differences for oxygen and lactate were made between 5 and 10 min of the exercise. Flow in the femoral vein was measured using constant infusion of saline near 0 degrees C. Since a cuff was inflated just below the knee during the measurements and because the hamstrings were inactive, the measured flow represented primarily the perfusion of the knee extensors. Blood flow increased linearly with work load right up to an average value of 5.7 l min-1. Mean arterial pressure was unchanged up to a work load of 30 W, but increased thereafter from 100 to 130 mmHg. The femoral arterial-venous oxygen difference at maximum work averaged 14.6% (v/v), resulting in an oxygen uptake of 0.80 l min-1. With a mean estimated weight of the knee extensors of 2.30 kg the perfusion of maximally exercising skeletal muscle of man is thus in the order of 2.5 l kg-1 min-1, and the oxygen uptake 0.35 l kg-1 min-1. Limitations in the methods used previously to determine flow and/or the characteristics of the exercise model used may explain why earlier studies in man have failed to demonstrate the high perfusion of muscle reported here. It is concluded that muscle blood flow is closely related to the oxygen demand of the exercising muscles. The hyperaemia at low work intensities is due to vasodilatation, and an elevated mean arterial blood pressure only contributes to the linear increase in flow at high work rates. The magnitude of perfusion observed during intense exercise indicates that the vascular bed of skeletal muscle is not a limiting factor for oxygen transport. PMID:4057091

  20. Mathematical Modelling of a Brain Tumour Initiation and Early Development: A Coupled Model of Glioblastoma Growth, Pre-Existing Vessel Co-Option, Angiogenesis and Blood Perfusion.

    PubMed

    Cai, Yan; Wu, Jie; Li, Zhiyong; Long, Quan

    2016-01-01

    We propose a coupled mathematical modelling system to investigate glioblastoma growth in response to dynamic changes in chemical and haemodynamic microenvironments caused by pre-existing vessel co-option, remodelling, collapse and angiogenesis. A typical tree-like architecture network with different orders for vessel diameter is designed to model pre-existing vasculature in host tissue. The chemical substances including oxygen, vascular endothelial growth factor, extra-cellular matrix and matrix degradation enzymes are calculated based on the haemodynamic environment which is obtained by coupled modelling of intravascular blood flow with interstitial fluid flow. The haemodynamic changes, including vessel diameter and permeability, are introduced to reflect a series of pathological characteristics of abnormal tumour vessels including vessel dilation, leakage, angiogenesis, regression and collapse. Migrating cells are included as a new phenotype to describe the migration behaviour of malignant tumour cells. The simulation focuses on the avascular phase of tumour development and stops at an early phase of angiogenesis. The model is able to demonstrate the main features of glioblastoma growth in this phase such as the formation of pseudopalisades, cell migration along the host vessels, the pre-existing vasculature co-option, angiogenesis and remodelling. The model also enables us to examine the influence of initial conditions and local environment on the early phase of glioblastoma growth.

  1. Mathematical Modelling of a Brain Tumour Initiation and Early Development: A Coupled Model of Glioblastoma Growth, Pre-Existing Vessel Co-Option, Angiogenesis and Blood Perfusion

    PubMed Central

    Cai, Yan; Wu, Jie; Li, Zhiyong; Long, Quan

    2016-01-01

    We propose a coupled mathematical modelling system to investigate glioblastoma growth in response to dynamic changes in chemical and haemodynamic microenvironments caused by pre-existing vessel co-option, remodelling, collapse and angiogenesis. A typical tree-like architecture network with different orders for vessel diameter is designed to model pre-existing vasculature in host tissue. The chemical substances including oxygen, vascular endothelial growth factor, extra-cellular matrix and matrix degradation enzymes are calculated based on the haemodynamic environment which is obtained by coupled modelling of intravascular blood flow with interstitial fluid flow. The haemodynamic changes, including vessel diameter and permeability, are introduced to reflect a series of pathological characteristics of abnormal tumour vessels including vessel dilation, leakage, angiogenesis, regression and collapse. Migrating cells are included as a new phenotype to describe the migration behaviour of malignant tumour cells. The simulation focuses on the avascular phase of tumour development and stops at an early phase of angiogenesis. The model is able to demonstrate the main features of glioblastoma growth in this phase such as the formation of pseudopalisades, cell migration along the host vessels, the pre-existing vasculature co-option, angiogenesis and remodelling. The model also enables us to examine the influence of initial conditions and local environment on the early phase of glioblastoma growth. PMID:26934465

  2. Quantitative myocardial perfusion SPECT.

    PubMed

    Tsui, B M; Frey, E C; LaCroix, K J; Lalush, D S; McCartney, W H; King, M A; Gullberg, G T

    1998-01-01

    In recent years, there has been much interest in the clinical application of attenuation compensation to myocardial perfusion single photon emission computed tomography (SPECT) with the promise that accurate quantitative images can be obtained to improve clinical diagnoses. The different attenuation compensation methods that are available create confusion and some misconceptions. Also, attenuation-compensated images reveal other image-degrading effects including collimator-detector blurring and scatter that are not apparent in uncompensated images. This article presents basic concepts of the major factors that degrade the quality and quantitative accuracy of myocardial perfusion SPECT images, and includes a discussion of the various image reconstruction and compensation methods and misconceptions and pitfalls in implementation. The differences between the various compensation methods and their performance are demonstrated. Particular emphasis is directed to an approach that promises to provide quantitative myocardial perfusion SPECT images by accurately compensating for the 3-dimensional (3-D) attenuation, collimator-detector response, and scatter effects. With advances in the computer hardware and optimized implementation techniques, quantitatively accurate and high-quality myocardial perfusion SPECT images can be obtained in clinically acceptable processing time. Examples from simulation, phantom, and patient studies are used to demonstrate the various aspects of the investigation. We conclude that quantitative myocardial perfusion SPECT, which holds great promise to improve clinical diagnosis, is an achievable goal in the near future.

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

    PubMed Central

    Baker, Robert A.; Newland, Richard F.; Fenton, Carmel; McDonald, Michael; Willcox, Timothy W.; Merry, Alan F.

    2012-01-01

    Abstract: Improving and understanding clinical practice is an appropriate goal for the perfusion community. The Perfusion Downunder Collaboration has established a multi-center perfusion focused database aimed at achieving these goals through the development of quantitative quality indicators for clinical improvement through benchmarking. Data were collected using the Perfusion Downunder Collaboration database from procedures performed in eight Australian and New Zealand cardiac centers between March 2007 and February 2011. At the Perfusion Downunder Meeting in 2010, it was agreed by consensus, to report quality indicators (QI) for glucose level, arterial outlet temperature, and pCO2 management during cardiopulmonary bypass. The values chosen for each QI were: blood glucose ≥4 mmol/L and ≤10 mmol/L; arterial outlet temperature ≤37°C; and arterial blood gas pCO2 ≥ 35 and ≤45 mmHg. The QI data were used to derive benchmarks using the Achievable Benchmark of Care (ABC™) methodology to identify the incidence of QIs at the best performing centers. Five thousand four hundred and sixty-five procedures were evaluated to derive QI and benchmark data. The incidence of the blood glucose QI ranged from 37–96% of procedures, with a benchmark value of 90%. The arterial outlet temperature QI occurred in 16–98% of procedures with the benchmark of 94%; while the arterial pCO2 QI occurred in 21–91%, with the benchmark value of 80%. We have derived QIs and benchmark calculations for the management of several key aspects of cardiopulmonary bypass to provide a platform for improving the quality of perfusion practice. PMID:22730861

  4. Human males and females body thermoregulation: perfusion effect analysis.

    PubMed

    Acharya, Saraswati; Gurung, D B; Saxena, V P

    2014-10-01

    Skin temperature is a common physiological parameter that reflects thermal responses. Blood perfusion is an important part of the physiological processes that the human body undergoes in order to maintain homeostasis. This study focuses on the effect of perfusion on the temperature distribution in human males and females body in different thermal environment. The study has been carried out for one dimensional steady cases using finite element method. The input parameter of the model is the blood perfusion or volumetric flow rate within the tissue. The appropriate physical and physiological parameters together with suitable boundary conditions that affect the heat regulations have been incorporated in the model. The study is to have a better understanding that how does thermoregulation change in human males and females skin layered due to perfusion. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Mucosal iron in the control of iron absorption in a rat intestinal transplant model

    SciTech Connect

    Adams, P.C.; Zhong, R.; Haist, J.; Flanagan, P.R.; Grant, D.R. )

    1991-02-01

    Isogeneic intestinal transplantation of iron-loaded and iron-deficient intestine into iron-deficient rats was performed in 20 Lewis rats to isolate the effect of intestinal mucosal iron on iron absorption. Rats were iron loaded with three weekly IM injections of 50 mg of iron dextran and were rendered iron deficient with an iron-deficient diet for 3 weeks. Iron status was assessed by hepatic and gut mucosal iron determination. Uptake and transfer of 59Fe-ascorbate was measured in an isolated perfused segment of transplanted intestine 48 hours after transplantation. The mean rate of uptake of 59Fe from an iron-loaded intestine (mean mucosal iron concentration, 7.97 +/- 2.02 mumol/g) was 431 +/- 27 nmol/30 min, and from an iron-deficient intestine (mean mucosal iron concentration, 1.35 +/- .84 mumol/g), 743 +/- 222 nmol/30 min (P less than 0.001). The mean transfer of 59Fe from the mucosal cell to the body through an iron-loaded intestine was 63 +/- 22 nmol/30 min, and through an iron-deficient intestine was 86 +/- 32 nmol/30 min (P less than 0.05). These results suggest that the gut mucosal iron concentration regulates the uptake and transfer of iron in the intestine.

  6. Contactless mapping of rhythmical phenomena in tissue perfusion using PPGI

    NASA Astrophysics Data System (ADS)

    Huelsbusch, Markus; Blazek, Vladimir

    2002-04-01

    This paper presents the experimental setup and preliminary results of a near infrared CCD camera based Photoplethysmography Imaging (PPGI) system, which has been shown to be suitable for contactless and spatially resolved assessment of rhythmical blood volume changes in the skin. To visualize the complex rhythmical patterns in the dermal perfusion the Wavelet Transform is utilized. It is able to jointly assess time and frequency behavior of signals and thus allows to analyze instationary oscillations and variabilities in the different human rhythmics. The presented system is expected to provide new insights into the functional sequences of physiological tissue perfusion as well as of the perfusion status in ulcer formation and wound healing.

  7. Luxury perfusion phenomenon in acute herpes simplex virus encephalitis.

    PubMed

    Tanaka, M; Uesugi, M; Igeta, Y; Kondo, S; Sun, X; Hirai, S

    1995-02-01

    In a patient with acute herpes simplex virus (HSV) encephalitis, positron emission tomography (PET) demonstrated increased cerebral blood flow in the affected temporal lobe accompanied by reduction in the cerebral oxygen extraction fraction and the cerebral metabolic rate of oxygen, i.e., luxury perfusion. Follow-up PET studies showed reduction in cerebral perfusion until it was more closely coupled with oxygen metabolism after the resolution of the acute inflammation. These findings support previous single photon emission computed tomographic data and provide a pathophysiological background for the occurrence of hyperperfusion in HSV encephalitis. This is an interesting example of the luxury perfusion phenomenon occurring in a disease other than cerebral ischemia.

  8. Dual-energy perfusion-CT of pancreatic adenocarcinoma.

    PubMed

    Klauss, M; Stiller, W; Pahn, G; Fritz, F; Kieser, M; Werner, J; Kauczor, H U; Grenacher, L

    2013-02-01

    To evaluate the feasibility of dual-energy CT (DECT)-perfusion of pancreatic carcinomas for assessing the differences in perfusion, permeability and blood volume of healthy pancreatic tissue and histopathologically confirmed solid pancreatic carcinoma. 24 patients with histologically proven pancreatic carcinoma were examined prospectively with a 64-slice dual source CT using a dynamic sequence of 34 dual-energy (DE) acquisitions every 1.5s (80 ml of iodinated contrast material, 370 mg/ml, flow rate 5 ml/s). 80 kV(p), 140 kV(p), and weighted average (linearly blended M0.3) 120 kV(p)-equivalent dual-energy perfusion image data sets were evaluated with a body-perfusion CT tool (Body-PCT, Siemens Medical Solutions, Erlangen, Germany) for estimating perfusion, permeability, and blood volume values. Color-coded parameter maps were generated. In all 24 patients dual-energy CT-perfusion was. All carcinomas could be identified in the color-coded perfusion maps. Calculated perfusion, permeability and blood volume values were significantly lower in pancreatic carcinomas compared to healthy pancreatic tissue. Weighted average 120 kV(p)-equivalent perfusion-, permeability- and blood volume-values determined from DE image data were 0.27 ± 0.04 min(-1) vs. 0.91 ± 0.04 min(-1) (p<0.0001), 0.5 ± 0.07 *0.5 min(-1) vs. 0.67 ± 0.05 *0.5 min(-1) (p=0.06) and 0.49 ± 0.07 min(-1) vs. 1.28 ± 0.11 min(-1) (p<0.0001). Compared with 80 and 140 kV(p) the standard deviations of the kV(p)120 kV(p)-equivalent values were manifestly smaller. Dual-energy CT-perfusion of the pancreas is feasible. The use of DECT improves the accuracy of CT-perfusion of the pancreas by fully exploiting the advantages of enhanced iodine contrast at 80 kV(p) in combination with the noise reduction at 140 kV(p). Therefore using dual-energy perfusion data could improve the delineation of pancreatic carcinomas. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  9. 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.

  10. Mucosal integrity and sensitivity to acid in the proximal esophagus in patients with gastroesophageal reflux disease.

    PubMed

    van Hoeij, Froukje B; Weijenborg, Pim W; van den Bergh Weerman, Marius A; van den Wijngaard, René M J G J; Verheij, J; Smout, André J P M; Bredenoord, Albert J

    2016-07-01

    Acid reflux episodes that extend to the proximal esophagus are more likely to be perceived. This suggests that the proximal esophagus is more sensitive to acid than the distal esophagus, which could be caused by impaired mucosal integrity in the proximal esophagus. Our aim was to explore sensitivity to acid and mucosal integrity in different segments of the esophagus. We used a prospective observational study, including 12 patients with gastroesophageal reflux disease (GERD). After stopping acid secretion-inhibiting medication, two procedures were performed: an acid perfusion test and an upper endoscopy with electrical tissue impedance spectroscopy and esophageal biopsies. Proximal and distal sensitivity to acid and tissue impedance were measured in vivo, and mucosal permeability and epithelial intercellular spaces at different esophageal levels were measured in vitro. Mean lag time to heartburn perception was much shorter after proximal acid perfusion (0.8 min) than after distal acid perfusion (3.9 min) (P = 0.02). Median in vivo tissue impedance was significantly lower in the distal esophagus (4,563 Ω·m) compared with the proximal esophagus (8,170 Ω·m) (P = 0.002). Transepithelial permeability, as measured by the median fluorescein flux was significantly higher in the distal (2,051 nmol·cm(-2)·h(-1)) than in the proximal segment (368 nmol·cm(-2)·h(-1)) (P = 0.033). Intercellular space ratio and maximum heartburn intensity were not significantly different between the proximal and distal esophagus. In GERD patients off acid secretion-inhibiting medication, acid exposure in the proximal segment of the esophagus provokes symptoms earlier than acid exposure in the distal esophagus, whereas mucosal integrity is impaired more in the distal esophagus. These findings indicate that the enhanced sensitivity to proximal reflux episodes is not explained by increased mucosal permeability. Copyright © 2016 the American Physiological Society.

  11. Blood

    MedlinePlus

    ... spans vary from a few days to months. New cells are constantly being formed in the bone marrow. ... the bloodstream and are constantly being replaced by new cells. Blood also contains important proteins called clotting factors , ...

  12. Assessment of lung tumor response by perfusion CT.

    PubMed

    Coche, E

    2013-01-01

    Perfusion CT permits evaluation of lung cancer angiogenesis and response to therapy by demonstrating alterations in lung tumor vascularity. It is advocated that perfusion CT performed shortly after initiating therapy may provide a better evaluation of physiological changes rather than the conventional size assessment obtained with RECIST. The radiation dose,the volume of contrast medium delivered to the patient and the reproducibility of blood flow parameters remain an issue for this type of investigation.

  13. Pancreas tumor model in rabbit imaged by perfusion CT scans

    NASA Astrophysics Data System (ADS)

    Gunn, Jason; Tichauer, Kenneth; Moodie, Karen; Kane, Susan; Hoopes, Jack; Stewart, Errol E.; Hadway, Jennifer; Lee, Ting-Yim; Pereira, Stephen P.; Pogue, Brian W.

    2013-03-01

    The goal of this work was to develop and validate a pancreas tumor animal model to investigate the relationship between photodynamic therapy (PDT) effectiveness and photosensitizer drug delivery. More specifically, this work lays the foundation for investigating the utility of dynamic contrast enhanced blood perfusion imaging to be used to inform subsequent PDT. A VX2 carcinoma rabbit cell line was grown in the tail of the pancreas of three New Zealand White rabbits and approximately 3-4 weeks after implantation the rabbits were imaged on a CT scanner using a contrast enhanced perfusion protocol, providing parametric maps of blood flow, blood volume, mean transit time, and vascular permeability surface area product.

  14. [Portable peristaltic perfusion pumps].

    PubMed

    Magallón Pedrera, I; Soto Torres, I

    1999-11-01

    Portable peristaltic perfusion pumps allow one to administer pharmaceuticals in hospitals as well as in primary health care centers and furthermore these pumps present multiple advantages for patients and their families since they make it possible to carry out treatment in a patient's home while at the same time lowering the costs involved. The authors analyze the most out standing aspects of portable peristaltic perfusion pumps along with their characteristics, installation, programming, and how to turn them on; in addition, the authors list the maintenance care which these pumps require.

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

    PubMed Central

    Fichter, Andreas M.; Ritschl, Lucas M.; Borgmann, Anna; Humbs, Martin; Luppa, Peter B.; Wolff, Klaus-Dietrich; Mücke, Thomas

    2016-01-01

    Background Extracorporeal perfusion (ECP) might prolong the vital storage capabilities of composite free flaps, potentially opening a wide range of clinical applications. Aim of the study was the development a validated low-cost extracorporeal perfusion model for further research in small animal free flaps. Methods After establishing optimal perfusion settings, a specially designed extracorporeal perfusion system was evaluated during 8-hour perfusion of rat epigastric flaps followed by microvascular free flap transfer. Controls comprised sham-operation, ischemia and in vivo perfusion. Flaps and perfusate (diluted blood) were closely monitored by blood gas analysis, combined laser Doppler flowmetry and remission spectroscopy and Indocyanine-Green angiography. Evaluations were complemented by assessment of necrotic area and light microscopy at day 7. Results ECP was established and maintained for 8 hours with constant potassium and pH levels. Subsequent flap transfer was successful. Notably, the rate of necrosis of extracorporeally perfused flaps (27%) was even lower than after in vivo perfusion (49%), although not statistically significant (P = 0,083). After sham-operation, only 6% of the total flap area became necrotic, while 8-hour ischemia led to total flap loss (98%). Angiographic and histological findings confirmed these observations. Conclusions Vital storage capabilities of microvascular flaps can be prolonged by temporary ECP. Our study provides important insights on the pathophysiological processes during extracorporeal tissue perfusion and provides a validated small animal perfusion model for further studies. PMID:26808996

  16. Mucosal barrier injury, fever and infection in neutropenic patients with cancer: introducing the paradigm febrile mucositis.

    PubMed

    van der Velden, Walter J F M; Herbers, Alexandra H E; Netea, Mihai G; Blijlevens, Nicole M A

    2014-11-01

    Infection remains one of the most prominent complications after cytotoxic treatment for cancer. The connection between neutropenia and both infections and fever has long been designated as 'febrile neutropenia', but treatment with antimicrobial agents and haematopoietic growth factors has failed to significantly reduce its incidence. Moreover, emerging antimicrobial resistance is becoming a concern that necessitates the judicious use of available antimicrobial agents. In addition to neutropenia, patients who receive cytotoxic therapy experience mucosal barrier injury (MBI) or 'mucositis'. MBI creates a port-de-entrée for resident micro-organisms to cause blood stream infections and contributes directly to the occurrence of fever by disrupting the highly regulated host-microbe interactions, which, even in the absence of an infection, can result in strong inflammatory reactions. Indeed, MBI has been shown to be a pivotal factor in the occurrence of inflammatory complications after cytotoxic therapy. Hence, the concept 'febrile neutropenia' alone may no longer suffice and a new concept 'febrile mucositis' should be recognized as the two are at least complementary. This review we summarizes the existing evidence for both paradigms and proposes new therapeutic approaches to tackle the perturbed host-microbe interactions arising from cytotoxic therapy-induced tissue damage in order to reduce fever in neutropenic patients with cancer. © 2014 John Wiley & Sons Ltd.

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

    PubMed

    Sefić Pašić, Irmina; Pašić, Anes; Kristić, Spomenka; Beganović, Adnan; Čarovac, Aladin; Džananović, Amra; Lincender, Lidija; Vegar Zubović, Sandra

    2015-08-01

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

  18. Influence of tissue movements on laser Doppler perfusion imaging

    NASA Astrophysics Data System (ADS)

    Karlsson, Daniel M.; Larsson, Marcus; Stroemberg, Tomas; Wardell, Karin

    2002-05-01

    The microvascular perfusion can be measured using laser Doppler blood flowmetry (LDF), a technique sensitive to the concentration of moving blood cells and their velocity. However, movements of the tissue itself can cause artifacts in the perfusion readings. In a clinical situation, these movement induced artifacts may arise from patient movements or from movements of internal organs e.g. the intestines or the beating heart. Therefore, we have studied how a well-controlled tissue movement affects the LDF signals during different flow conditions and for different surface structures. Tissue perfusion was recorded non-touch in one point using a laser Doppler perfusion imager. During the measurements the object was placed on a shaker that generated the movement (both horizontal and vertical). Measurements were carried out both on DELRIN (polyacetal plastic) and the fingertip, for a wide range of velocities (0-3 cm/s). The influence of the microvascular perfusion was evaluated by occluding the brachial artery as well as blood emptying the finger and by using a flow model. The LDF signals were correlated to the movement. In vivo measurements showed that velocities above 0.8 cm/s gave a significant contribution to the perfusion signal. Corresponding velocities for the DELRIN piece were higher (1.4 - 2.6 cm/s), and dependent on the surface structures and reflecting properties. By reducing the amount of specular reflection the movement influence was substantially lowered.

  19. Vitamin D and mucosal immune function

    PubMed Central

    Sun, Jun

    2010-01-01

    Purpose of review Significant advances have been made in the characterization of Vitamin D and the Vitamin D receptor (VDR) in immune function. The studies of signaling pathways involved in the response to infection and inflammation have led to a more detailed understanding of the cellular response to Vitamin D through VDR. This review summarizes recent progress in understanding how Vitamin D contributes to mucosal immune function, particularly in relation to the molecular mechanisms by which Vitamin D and VDR influence mucosal immunity, bacterial infection, and inflammation. Recent findings Recently, it was shown that Vitamin D modulates the T cell antigen receptor, further demonstrating that Vitamin D has a nonclassical role in immunoregulation. The anti-inflammation and anti-infection functions for Vitamin D are newly identified and highly significant activities. Vitamin D/VDR have multiple critical functions in regulating the response to intestinal homeostasis, tight junctions, pathogen invasion, commensal bacterial colonization, antimicrobe peptide secretion, and mucosal defense. Interestingly, microorganisms modulate the VDR signaling pathway. Summary Vitamin D is known as a key player in calcium homeostasis and electrolyte and blood pressure regulation. Recently, important progress has been made in understanding how the noncanonical activities of Vitamin D influence the pathogenesis and prevention of human disease. Vitamin D and VDR are directly involved in T cell antigen receptor signaling. The involvement of Vitamin D/VDR in anti-inflammation and anti-infection represents a newly identified and highly significant activity for VDR. Studies have indicated that the dysregulation of VDR may lead to exaggerated inflammatory responses, raising the possibility that defects in Vitamin D and VDR signaling transduction may be linked to bacterial infection and chronic inflammation. Further characterization of Vitamin D/VDR will help elucidate the pathogenesis of

  20. Biology of HIV Mucosal Transmission

    PubMed Central

    Wu, Li

    2008-01-01

    Purpose of review HIV-1 mucosal transmission plays a critical role in HIV-1 infection and AIDS pathogenesis. This review summarizes the latest advances in biological studies of HIV-1 mucosal transmission, highlighting the implications of these studies in the development of microbicides to prevent HIV-1 transmission. Recent findings New studies of initial HIV-1 infection using improved culture models updated the current view of mucosal transmission. Mechanistic studies enhanced our understanding of cell-cell transmission of HIV-1 mediated by the major target cells, including dendritic cells, CD4+ T cells, and macrophages. Increasing evidence indicated the significance of host factors and immune responses in HIV-1 mucosal infection and transmission. Summary Recent progress in HIV-1 mucosal infection and transmission enriches our knowledge of virus-host interactions and viral pathogenesis. Functional studies of HIV-1 interactions with host cells can provide new insights into the design of more effective approaches to combat HIV-1 infection and AIDS. PMID:18802490

  1. Omics in fish mucosal immunity.

    PubMed

    Salinas, Irene; Magadán, Susana

    2017-10-01

    The mucosal immune system of fish is a complex network of immune cells and molecules that are constantly surveilling the environment and protecting the host from infection. A number of "omics" tools are now available and utilized to understand the complexity of mucosal immune systems in non-traditional animal models. This review summarizes recent advances in the implementation of "omics" tools pertaining to the four mucosa-associated lymphoid tissues in teleosts. Genomics, transcriptomics, proteomics, and "omics" in microbiome research require interdisciplinary collaboration and careful experimental design. The data-rich datasets generated are proving really useful at discovering new innate immune players in fish mucosal secretions, identifying novel markers of specific mucosal immune responses, unraveling the diversity of the B and T cell repertoires and characterizing the diversity of the microbial communities present in teleost mucosal surfaces. Bioinformatics, data analysis and storage platforms should be developed to facilitate rapid processing of large datasets, especially when mammalian tools such as bioinformatics analysis software are not available in fishes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. 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.

  3. 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.

  4. Perfusion and diffusion limitations in middle ear gas exchange: the exchange of CO2 as a test case.

    PubMed

    Marcusohn, Yael; Ar, Amos; Dirckx, Joris J J

    2010-06-14

    A long standing debate on perfusion/diffusion limitations in the context of middle ear (ME) gas exchange was revisited using data obtained from previous iso-pressure gas-exchange measurements in different mammals. We tried to determine whether the exchange of CO(2) in the ME is limited by perfusion or by diffusion by comparing the mass specific cardiac output (msQ) and the mass specific initial CO(2) flow rate into air-washed MEs (msV(i) CO(2)) of rabbits and rats. Based on previously published allometry at rest, the msQ was 0.154 mL/(min g) in rabbits (mean body weight: 2800 g) and 0.259 mL/(min g) in rats (mean body weight: 179.1 g); msV(i) CO(2) (Delta t=0) was 0.109+/-0.047 microL/(h g) in rabbits (n=16) and 0.170+/-0.094 microL/(h g) in rats (n=9). Similar ratios were found when an allometric comparison was made between the ratio of msV(i) CO(2) (Delta t=0) (approximately 0.64), and the ratio of msQs (approximately 0.59) in rabbits and rats. If the active mucosal surface areas of MEs of rabbits and rats are directly proportional to their masses as are the masses of their hearts and if their msQs are proportional to the rates of blood flows in the ME mucosa, these results support the assumption that the exchange of CO(2) in the ME of mammals is mainly perfusion (and not diffusion) dependent.

  5. Warm vs. cold perfusion techniques to rescue rodent liver grafts.

    PubMed

    Schlegel, Andrea; Kron, Philipp; Graf, Rolf; Dutkowski, Philipp; Clavien, Pierre-Alain

    2014-12-01

    A variety of liver perfusion techniques have been proposed to protect liver grafts prior to implantation. We compared hypothermic and normothermic oxygenated perfusion techniques in a rat liver transplant model, using higher risk grafts obtained after cardiac arrest (DCD). Rat livers were subjected to 30 or 60 min in situ warm ischemia, without application of heparin. Livers were excised and stored for 4 h at 4°C, mimicking DCD organ procurement, followed by conventional organ transport. In experimental groups, DCD liver grafts received a 4 h normothermic oxygenated perfusion through the portal vein and the hepatic artery instead of cold storage. The perfusate consisted of either full blood or leukocyte-depleted blood (normothermic groups). Other livers underwent hypothermic oxygenated perfusion (HOPE) for 1 h after warm ischemia and 4 h cold storage (HOPE group). Liver injury was assessed during machine perfusion and after isolated liver reperfusion, and by orthotopic liver transplantation (OLT). DCD livers, subjected to normothermic perfusion, disclosed reduced injury and improved survival compared to cold storage after limited warm ischemia of 30 min (70%; 7/10), but failed to protect from lethal injury in grafts exposed to 60 min warm ischemia (0%; 0/10). This finding was consistent with Kupffer and endothelial cell activation in cold stored and normothermic perfused livers. In contrast, HOPE protected from hepatocyte and non-parenchymal cell injury and led to 90% (9/10) and 63% (5/8) animal survival after 30 and 60 min of donor warm ischemia, respectively. This is the first evidence that HOPE is superior to normothermic oxygenated perfusion in a clinically relevant model through modulation of the innate immunity and endothelial cell activation. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  6. Helminths and mucosal immune modulation.

    PubMed

    Weinstock, Joel V

    2006-08-01

    Geographic and ethnic variations in ulcerative colitis and Crohn's disease frequency suggest that environmental factors affect disease risk. Prevention of parasitic worms (helminths) through improved hygiene may be one factor leading to the increased disease prevalence. Helminths alter host mucosal and systemic immunity. Animals exposed to helminths are protected from experimental colitis and other immunological diseases, and helminthic colonization can be used to treat ongoing murine and human disease. Helminths induce mucosal T cells to make Th2 and regulatory cytokines. Helminth-induced mucosal IL4, TGFbeta, and IL10 likely are part of the protective process. Helminths affect pathways of innate immunity like TLR4 expression and function. Worms also induce various regulatory-type T-cell subsets in the gut that limit effector T-cell growth and function. These effects of once ever-present helminths may have protected people from immune-mediated illnesses like inflammatory bowel disease.

  7. A reappraisal of retrograde cerebral perfusion

    PubMed Central

    2013-01-01

    Brain protection during aortic arch surgery by perfusing cold oxygenated blood into the superior vena cava was first reported by Lemole et al. In 1990 Ueda and associates first described the routine use of continuous retrograde cerebral perfusion (RCP) in thoracic aortic surgery for the purpose of cerebral protection during the interval of obligatory interruption of anterograde cerebral flow. The beneficial effects of RCP may be its ability to sustain brain hypothermia during hypothermic circulatory arrest (HCA) and removal of embolic material from the arterial circulation of the brain. RCP can offer effective brain protection during HCA for about 40 to 60 minutes. Animal experiments revealed that RCP provided inadequate cerebral perfusion and that neurological recovery was improved with selective antegrade cerebral perfusion (ACP), however, both RCP and ACP provide comparable clinical outcomes regarding both the mortality and stroke rates by risk-adjusted and case-matched comparative study. RCP still remains a valuable adjunct for brain protection during aortic arch repair in particular pathologies and patients. PMID:23977600

  8. Coupling between resting cerebral perfusion and EEG.

    PubMed

    O'Gorman, R L; Poil, S-S; Brandeis, D; Klaver, P; Bollmann, S; Ghisleni, C; Lüchinger, R; Martin, E; Shankaranarayanan, A; Alsop, D C; Michels, L

    2013-07-01

    While several studies have investigated interactions between the electroencephalography (EEG) and functional magnetic resonance imaging BOLD signal fluctuations, less is known about the associations between EEG oscillations and baseline brain haemodynamics, and few studies have examined the link between EEG power outside the alpha band and baseline perfusion. Here we compare whole-brain arterial spin labelling perfusion MRI and EEG in a group of healthy adults (n = 16, ten females, median age: 27 years, range 21-48) during an eyes closed rest condition. Correlations emerged between perfusion and global average EEG power in low (delta: 2-4 Hz and theta: 4-7 Hz), middle (alpha: 8-13 Hz), and high (beta: 13-30 Hz and gamma: 30-45 Hz) frequency bands in both cortical and sub-cortical regions. The correlations were predominately positive in middle and high-frequency bands, and negative in delta. In addition, central alpha frequency positively correlated with perfusion in a network of brain regions associated with the modulation of attention and preparedness for external input, and central theta frequency correlated negatively with a widespread network of cortical regions. These results indicate that the coupling between average EEG power/frequency and local cerebral blood flow varies in a frequency specific manner. Our results are consistent with longstanding concepts that decreasing EEG frequencies which in general map onto decreasing levels of activation.

  9. Mucosal immunoglobulins at respiratory surfaces mark an ancient association that predates the emergence of tetrapods.

    PubMed

    Xu, Zhen; Takizawa, Fumio; Parra, David; Gómez, Daniela; von Gersdorff Jørgensen, Louise; LaPatra, Scott E; Sunyer, J Oriol

    2016-02-12

    Gas-exchange structures are critical for acquiring oxygen, but they also represent portals for pathogen entry. Local mucosal immunoglobulin responses against pathogens in specialized respiratory organs have only been described in tetrapods. Since fish gills are considered a mucosal surface, we hypothesized that a dedicated mucosal immunoglobulin response would be generated within its mucosa on microbial exposure. Supporting this hypothesis, here we demonstrate that following pathogen exposure, IgT(+) B cells proliferate and generate pathogen-specific IgT within the gills of fish, thus providing the first example of locally induced immunoglobulin in the mucosa of a cold-blooded species. Moreover, we demonstrate that gill microbiota is predominantly coated with IgT, thus providing previously unappreciated evidence that the microbiota present at a respiratory surface of a vertebrate is recognized by a mucosal immunoglobulin. Our findings indicate that respiratory surfaces and mucosal immunoglobulins are part of an ancient association that predates the emergence of tetrapods.

  10. Mucosal immunoglobulins at respiratory surfaces mark an ancient association that predates the emergence of tetrapods

    PubMed Central

    Xu, Zhen; Takizawa, Fumio; Parra, David; Gómez, Daniela; von Gersdorff Jørgensen, Louise; LaPatra, Scott E.; Sunyer, J. Oriol

    2016-01-01

    Gas-exchange structures are critical for acquiring oxygen, but they also represent portals for pathogen entry. Local mucosal immunoglobulin responses against pathogens in specialized respiratory organs have only been described in tetrapods. Since fish gills are considered a mucosal surface, we hypothesized that a dedicated mucosal immunoglobulin response would be generated within its mucosa on microbial exposure. Supporting this hypothesis, here we demonstrate that following pathogen exposure, IgT+ B cells proliferate and generate pathogen-specific IgT within the gills of fish, thus providing the first example of locally induced immunoglobulin in the mucosa of a cold-blooded species. Moreover, we demonstrate that gill microbiota is predominantly coated with IgT, thus providing previously unappreciated evidence that the microbiota present at a respiratory surface of a vertebrate is recognized by a mucosal immunoglobulin. Our findings indicate that respiratory surfaces and mucosal immunoglobulins are part of an ancient association that predates the emergence of tetrapods. PMID:26869478

  11. Three-dimensional tumor perfusion reconstruction using fractal interpolation functions.

    PubMed

    Craciunescu, O I; Das, S K; Poulson, J M; Samulski, T V

    2001-04-01

    It has been shown that the perfusion of blood in tumor tissue can be approximated using the relative perfusion index determined from dynamic contrast-enhanced magnetic resonance imaging (DE-MRI) of the tumor blood pool. Also, it was concluded in a previous report that the blood perfusion in a two-dimensional (2-D) tumor vessel network has a fractal structure and that the evolution of the perfusion front can be characterized using invasion percolation. In this paper, the three-dimensional (3-D) tumor perfusion is reconstructed from the 2-D slices using the method of fractal interpolation functions (FIF), i.e., the piecewise self-affine fractal interpolation model (PSAFIM) and the piecewise hidden variable fractal interpolation model (PHVFIM). The fractal models are compared to classical interpolation techniques (linear, spline, polynomial) by means of determining the 2-D fractal dimension of the reconstructed slices. Using FIFs instead of classical interpolation techniques better conserves the fractal-like structure of the perfusion data. Among the two FIF methods, PHVFIM conserves the 3-D fractality better due to the cross correlation that exists between the data in the 2-D slices and the data along the reconstructed direction. The 3-D structures resulting from PHVFIM have a fractal dimension within 3%-5% of the one reported in literature for 3-D percolation. It is, thus, concluded that the reconstructed 3-D perfusion has a percolation-like scaling. As the perfusion term from bio-heat equation is possibly better described by reconstruction via fractal interpolation, a more suitable computation of the temperature field induced during hyperthermia treatments is expected.

  12. Dynamic perfusion CT in brain tumors.

    PubMed

    Yeung, Timothy Pok Chi; Bauman, Glenn; Yartsev, Slav; Fainardi, Enrico; Macdonald, David; Lee, Ting-Yim

    2015-12-01

    Dynamic perfusion CT (PCT) is an imaging technique for assessing the vascular supply and hemodynamics of brain tumors by measuring blood flow, blood volume, and permeability-surface area product. These PCT parameters provide information complementary to histopathologic assessments and have been used for grading brain tumors, distinguishing high-grade gliomas from other brain lesions, differentiating true progression from post-treatment effects, and predicting prognosis after treatments. In this review, the basic principles of PCT are described, and applications of PCT of brain tumors are discussed. The advantages and current challenges, along with possible solutions, of PCT are presented. Copyright © 2015. Published by Elsevier Ireland Ltd.

  13. Lesion area detection using source image correlation coefficient for CT perfusion imaging.

    PubMed

    Fan Zhu; Rodriguez Gonzalez, David; Carpenter, Trevor; Atkinson, Malcolm; Wardlaw, Joanna

    2013-09-01

    Computer tomography (CT) perfusion imaging is widely used to calculate brain hemodynamic quantities such as cerebral blood flow, cerebral blood volume, and mean transit time that aid the diagnosis of acute stroke. Since perfusion source images contain more information than hemodynamic maps, good utilization of the source images can lead to better understanding than the hemodynamic maps alone. Correlation-coefficient tests are used in our approach to measure the similarity between healthy tissue time-concentration curves and unknown curves. This information is then used to differentiate penumbra and dead tissues from healthy tissues. The goal of the segmentation is to fully utilize information in the perfusion source images. Our method directly identifies suspected abnormal areas from perfusion source images and then delivers a suggested segmentation of healthy, penumbra, and dead tissue. This approach is designed to handle CT perfusion images, but it can also be used to detect lesion areas in magnetic resonance perfusion images.

  14. A rat model against chemotherapy plus radiation-induced oral mucositis

    PubMed Central

    Patel, Alkesh; Rajesh, S.; Chandrashekhar, V.M.; Rathnam, Shivprakash; Shah, Karishma; Mallikarjuna Rao, C.; Nandakumar, K.

    2013-01-01

    Objectives Present study was aimed at developing an experimental model of oral mucositis in rats using a combination of chemotherapeutic agent and radiation. Study design Female Wistar rats (150–200 g) were divided into 3 groups (n = 6). Rats in group 1 (normal control) and group 2 (mucositis control) were treated with vehicle. Rats in group 3 were treated with l-glutamine (1 g/kg, p.o.; 15 days) before and after mucositis induction. Oral mucositis was induced by busulfan (6 mg/kg, p.o.; 4 days) and the tongue exposed to infrared (IR) radiation of intensity 40 mV/cm2 for 5 s on the 1st, 4th and 10th days of challenge using a tail flick apparatus. Parameters monitored were body weight, food intake, blood count and survival. Oral mucositis score (OMS) was recorded daily. Histological changes of the irradiated tongue were assessed by hematoxylin and eosin staining. Results Busulfan and IR radiation significantly reduced body weight and food intake of the mucositis control group as compared to normal control. Clear ulceration of the tongue reflected in the OMS. Histopathology of the tongue revealed intense lymphocytic infiltration, decreased thickness of squamous epithelial cell layer, decrease in number of blood vessels, and necrosis of cells along with pseudo-membrane formation in the mucositis control group. These findings suggested that oral mucositis was successfully induced and treatment with l-glutamine partially reversed these conditions. Conclusion Oral mucositis was established successfully in rats by the combination of chemotherapeutic agent and IR radiation. This may be a useful model for screening drugs in the treatment of oral mucositis. PMID:24227960

  15. The Therapeutic Effect of PLAG against Oral Mucositis in Hamster and Mouse Model

    PubMed Central

    Lee, Ha-Reum; Yoo, Nina; Kim, Joo Heon; Sohn, Ki-Young; Kim, Heung-Jae; Kim, Myung-Hwan; Han, Mi Young; Yoon, Sun Young; Kim, Jae Wha

    2016-01-01

    Chemotherapy-induced mucositis can limit the effectiveness of cancer therapy and increase the risk of infections. However, no specific therapy for protection against mucositis is currently available. In this study, we investigated the therapeutic effect of PLAG (1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol, acetylated diglyceride) in 5-fluorouracil (5-FU)-induced oral mucositis animal models. Hamsters were administered 5-FU (80 mg/kg) intraperitoneally on days 0, 6, and 9. The animals’ cheek pouches were then scratched equally with the tip of an 18-gage needle on days 1, 2, and 7. PLAG was administered daily at 250 mg/kg/day. PLAG administration significantly reduced 5-FU/scratching-induced mucositis. Dramatic reversal of weight loss in PLAG-treated hamsters with mucositis was observed. Histochemical staining data also revealed newly differentiated epidermis and blood vessels in the cheek pouches of PLAG-treated hamsters, indicative of recovery. Whole blood analyses indicated that PLAG prevents 5-FU-induced excessive neutrophil transmigration to the infection site and eventually stabilizes the number of circulating neutrophils. In a mouse mucositis model, mice with 5-FU-induced disease treated with PLAG exhibited resistance to body-weight loss compared with mice that received 5-FU or 5-FU/scratching alone. PLAG also dramatically reversed mucositis-associated weight loss and inhibited mucositis-induced inflammatory responses in the tongue and serum. These data suggest that PLAG enhances recovery from 5-FU-induced oral mucositis and may therefore be a useful therapeutic agent for treating side effects of chemotherapy, such as mucositis and cachexia. PMID:27800302

  16. Immunoglobulin Responses at the Mucosal Interface

    PubMed Central

    Chen, Kang; Chorny, Alejo

    2011-01-01

    Mucosal surfaces are colonized by large communities of commensal bacteria and represent the primary site of entry for pathogenic agents. To prevent microbial intrusion, mucosal B cells release large amounts of immunoglobulin (Ig) molecules through multiple follicular and extrafollicular pathways. IgA is the most abundant antibody isotype in mucosal secretions and owes its success in frontline immunity to its ability to undergo transcytosis across epithelial cells. In addition to translocating IgA onto the mucosal surface, epithelial cells educate the mucosal immune system as to the composition of the local microbiota and instruct B cells to initiate IgA responses that generate immune protection while preserving immune homeostasis. Here we review recent advances in our understanding of the cellular interactions and signaling pathways governing IgA production at mucosal surfaces and discuss new findings on the regulation and function of mucosal IgD, the most enigmatic isotype of our mucosal antibody repertoire. PMID:21219173

  17. Mast cells mediate acid-induced augmentation of opossum esophageal blood flow via histamine and nitric oxide.

    PubMed

    Feldman, M J; Morris, G P; Dinda, P K; Paterson, W G

    1996-01-01

    Increased esophageal blood flow during reflux episodes may play an important role in mucosal resistance to injury, although the mechanism remains unclear. Decreased stainable mast cells and increased luminal histamine release during acid exposure has been previously documented. Therefore, the role of mast cells, nerves, histamine, and nitric oxide in mediating increased blood flow during acid challenge of the distal esophagus was investigated. The effects of the mast cell stabilizers disodium cromoglycate and doxantrazole, the neurotoxin tetrodotoxin, the histamine H1 receptor antagonist promethazine, and the NO synthase inhibitor N omega-nitro-L-arginine methyl ester were examined by monitoring opossum esophageal histamine release and blood flow during perfusion with 100 mmol/L HCl. Luminal acid challenge significantly increased both histamine release and blood flow (P < 0.05). Disodium cromoglycate, promethazine, and N omega-nitro-L-arginine methyl ester attenuated the increase in blood flow to basal (saline-perfused) levels. Tetrodotoxin did not prevent an acute increase in blood flow that rapidly returned to baseline, likely from the ensuing hypotension. These findings provide evidence that mast cell-derived histamine, acting through an NO-dependent mechanism, plays a central role in the response of the esophageal microcirculation to luminal acid.

  18. Immunology of Gut Mucosal Vaccines

    PubMed Central

    Pasetti, Marcela F.; Simon, Jakub K.; Sztein, Marcelo B.; Levine, Myron M.

    2011-01-01

    Summary Understanding the mechanisms underlying the induction of immunity in the gastrointestinal mucosa following oral immunization and the cross-talk between mucosal and systemic immunity should expedite the development of vaccines to diminish the global burden caused by enteric pathogens. Identifying an immunological correlate of protection in the course of field trials of efficacy, animal models (when available), or human challenge studies is also invaluable. In industrialized country populations, live attenuated vaccines (e.g. polio, typhoid, and rotavirus) mimic natural infection and generate robust protective immune responses. In contrast, a major challenge is to understand and overcome the barriers responsible for the diminished immunogenicity and efficacy of the same enteric vaccines in underprivileged populations in developing countries. Success in developing vaccines against some enteric pathogens has heretofore been elusive (e.g. Shigella). Different types of oral vaccines can selectively or inclusively elicit mucosal secretory immunoglobulin A and serum immunoglobulin G antibodies and a variety of cell-mediated immune responses. Areas of research that require acceleration include interaction between the gut innate immune system and the stimulation of adaptive immunity, development of safe yet effective mucosal adjuvants, better understanding of homing to the mucosa of immunologically relevant cells, and elicitation of mucosal immunologic memory. This review dissects the immune responses elicited in humans by enteric vaccines. PMID:21198669

  19. Quantitative measurement of tissue perfusion and diffusion in vivo.

    PubMed

    Chenevert, T L; Pipe, J G; Williams, D M; Brunberg, J A

    1991-01-01

    Magnetic resonance imaging techniques designed for sensitivity to microscopic motions of water diffusion and blood flow in the capillary network are also exceptionally sensitive to bulk motion properties of the tissue, which may lead to contrast artifact and large quantitative errors. The magnitude of bulk motion error that exists in human brain perfusion/diffusion imaging and the inability of cardiac gating to adequately control this motion are demonstrated by direct measurement of phase stability of voxels localized in the brain. Two methods are introduced to reduce bulk motion phase error. The first, a postprocessing phase correction algorithm, reduces coarse phase error but is inadequate by itself for quantitative perfusion/diffusion MRI. The second method employs orthogonal slice selection gradients to define a column of tissue in the object, from which echoes may be combined in a phase-insensitive manner to measure more reliably the targeted signal attenuation. Applying this acquisition technique and a simplistic model of perfusion and diffusion signal attenuations yields an estimated perfusion fraction of 3.4 +/- 1.1% and diffusion coefficient of 1.1 +/- 0.2 x 10(-5) cm2/s in the white matter of one normal volunteer. Successful separation of perfusion and diffusion effects by this technique is supported in a dynamic study of calf muscle. Periods of normal blood flow, low flow, and reactive hyperemia are clearly distinguished in the quantitative perfusion results, whereas measured diffusion remained nearly constant.

  20. Pulmonary artery perfusion versus no pulmonary perfusion during cardiopulmonary bypass in patients with COPD: a randomised clinical trial

    PubMed Central

    Buggeskov, Katrine B; Sundskard, Martin M; Jonassen, Thomas; Andersen, Lars W; Secher, Niels H; Ravn, Hanne B; Steinbrüchel, Daniel A; Jakobsen, Janus C; Wetterslev, Jørn

    2016-01-01

    Introduction Absence of pulmonary perfusion during cardiopulmonary bypass (CPB) may be associated with reduced postoperative oxygenation. Effects of active pulmonary artery perfusion were explored in patients with chronic obstructive pulmonary disease (COPD) undergoing cardiac surgery. Methods 90 patients were randomised to receive pulmonary artery perfusion during CPB with either oxygenated blood (n=30) or histidine-tryptophan-ketoglutarate (HTK) solution (n=29) compared with no pulmonary perfusion (n=31). The coprimary outcomes were the inverse oxygenation index compared at 21 hours after starting CPB and longitudinally in a mixed-effects model (MEM). Secondary outcomes were tracheal intubation time, serious adverse events, mortality, days alive outside the intensive care unit (ICU) and outside the hospital. Results 21 hours after starting CPB patients receiving pulmonary artery perfusion with normothermic oxygenated blood had a higher oxygenation index compared with no pulmonary perfusion (mean difference (MD) 0.94; 95% CI 0.05 to 1.83; p=0.04). The blood group had also a higher oxygenation index both longitudinally (MEM, p=0.009) and at 21 hours (MD 0.99; CI 0.29 to 1.69; p=0.007) compared with the HTK group. The latest result corresponds to a difference in the arterial partial pressure of oxygen of 23 mm Hg with a median fraction of inspired oxygen of 0.32. Yet the blood or HTK groups did not demonstrate a longitudinally higher oxygenation index compared with no pulmonary perfusion (MEM, p=0.57 and 0.17). Similarly, at 21 hours there was no difference in the oxygenation index between the HTK group and those no pulmonary perfusion (MD 0.06; 95% CI −0.73 to 0.86; p=0.87). There were no statistical significant differences between the groups for the secondary outcomes. Discussion Pulmonary artery perfusion with normothermic oxygenated blood during cardiopulmonary bypass appears to improve postoperative oxygenation in patients with COPD undergoing

  1. The Perfusion Downunder collaborative database project.

    PubMed

    Newland, Richard; Baker, Robert A; Stanley, Rebecca; Place, Katherine; Willcox, Timothy W

    2008-09-01

    The Perfusion Downunder Collaboration provides research infrastructure and support to the Australian and New Zealand perfusion community, with the objective of determining best practices and producing relevant research publications. The Perfusion Downunder Collaborative Database (PDUCD) has been created for the purpose of collecting a dataset for cardiopulmonary bypass (CPB) procedures that includes integration with commercially available CPB data collection software. Initial testing of the PDUCD involved collection of data from four Australian and New Zealand hospitals from March to July 2007. Data from 513 procedures were compared with the concurrent Australasian Society of Cardiac and Thoracic Surgeons (ASCTS) database report to assess the validity of the collected data. Demographic, preoperative, and procedural variables were comparable between databases. Perfusion variables showed a median nasopharyngeal temperature of 36.7degrees C at separation from CPB (range, 35.3-37.5 degrees C), which was similar to maximum nasopharyngeal temperature (median, 36.8 degrees C). Median arterial flow and mean arterial pressure were 4.2 L/min and 57.2 mmHg, respectively. Control charts indicate a central tendency of 12.5 minutes for mean arterial pressure < 50 mmHg and 3.5 minutes for arterial flow < 1.6 L/min/m2 (cumulative time). There was no difference in median minimum and maximum blood glucose between diabetic and nondiabetic patients during CPB with 40% of patients receiving insulin. Median minimum and maximum activated clotting time (ACT) during CPB was 581 and 692 seconds, respectively. Outcome data for isolated coronary artery bypass grafting were similar for mortality (only) (both 1.8%). Initial data collection showed concurrent validity compared with the ASCTS database. The inclusion of a large quantity of calculated CPB variables in the dataset highlights the benefits of electronic data collection as a research tool within a collaborative research network and the

  2. 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.

  3. 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.

  4. 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.

  5. Perfusion abnormalities in hemimegalencephaly.

    PubMed

    Wintermark, P; Roulet-Perez, E; Maeder-Ingvar, M; Moessinger, A C; Gudinchet, F; Meuli, R

    2009-04-01

    Cerebrovascular changes are rarely discussed in patients with hemimegalencephaly. These alterations have previously been associated with epileptical activity. We report the case of a 36-week gestation neonate presenting with total right hemimegalencephaly, as demonstrated by a magnetic resonance imaging (MRI) performed in the first days of life. Perfusion-weighted imaging displayed a clear hypervascularization of the right hemisphere. Diffusion-tensor imaging showed an arrangement of white matter fibers concentrically around the ventricle on the right hemisphere. AngioMRI showed an obvious asymmetry in the size of the middle cerebral arteries, with the right middle cerebral artery being prominent. The baby was free of clinical seizures during his first week of life. An electroencephalogram at that time displayed an asymmetric background activity, but no electrical seizures. Perfusion anomalies in hemimegalencephaly may not necessarily be related to epileptical activity, but may be related to vessel alterations. (c) Georg Thieme Verlag KG Stuttgart, New York.

  6. USE OF A PROGRAMMABLE CALCULATOR IN CARDIOPULMONARY PERFUSION.

    PubMed

    Mills, J David; Tallent, Jerome H.

    1978-06-01

    This study describes a hand-held, battery-powered, programmable instrument (Calculator Model SR-52) that can be taken directly into the operating room by cardiopulmonary perfusionists. Three programs are described in detail: 1) Cardiopulmonary perfusion parameters and estimated blood volume; 2) blood gas parameters and saturations, with temperature corrections; and 3) cardiopulmonary oxygen transfer and oxygenator efficiency. This inexpensive calculator allows perfusion personnel to manipulate easily-derived data into values which heretofore have required elaborate nomograms or special slide rules-or were not available within a reasonable computational time.

  7. Esophageal acid sensitivity and mucosal integrity in patients with functional heartburn.

    PubMed

    Weijenborg, P W; Smout, A J P M; Bredenoord, A J

    2016-11-01

    Patients with functional heartburn (FH) experience troublesome heartburn that is not related to gastroesophageal reflux. The etiology of the heartburn sensation in FH patients is unknown. In patients with reflux disease, esophageal hypersensitivity seems associated with impaired mucosal integrity. We aimed to determine esophageal sensitivity and mucosal integrity in FH and non-erosive reflux disease (NERD) patients. In this prospective experimental study, we performed an acid perfusion test and upper endoscopy with biopsies in 12 patients with NERD and nine patients with FH. Mucosal integrity was measured during endoscopy using electrical tissue impedance spectroscopy and biopsy specimens were analyzed in Ussing chambers for transepithelial electrical resistance and transepithelial permeability. Lag time to heartburn perception was significantly longer in FH patients (median 12 min) than in NERD patients (median 3 min). Once perceived, intensity of heartburn was scored equal with median visual analog scale 6.5 and 7.1 respectively. Esophageal mucosal integrity was also comparable between FH and NERD patients, both in vivo extracellular impedance and ex vivo transepithelial resistance and permeability were similar. Patients with FH did not show acid hypersensitivity as seen in patients with NERD. However, once perceived, intensity of heartburn is similar. Esophageal mucosal integrity is similar between NERD and FH patients, and is therefore unlikely to be the underlying cause of the observed difference in esophageal acid perception. © 2016 John Wiley & Sons Ltd.

  8. Effect of cardiac dysrhythmia on cerebral perfusion.

    PubMed

    Sand, B J; Rose, H B; Barker, W F

    1976-07-01

    Extracranial carotid arterial obstructive disease has been the entity most commonly associated with transient cerebrovascular insufficiency. A nonobstructive, frequently overlooked cause of cerebral ischemia is cardiac dysrhythmia. We have explored this by observations of experimental animals and of man. Blood flow and pressure in the carotid arteries of dogs were shown to be decreased by mechnically induced premature ventricular contractions. The significance of the cardiogenic contribution to altered cerebrovascular perfusion was studied by ocular and brachial plethysmography in 210 patients suspected by history of having carotid arterial insufficiency. Of the 210 patients, 62 demonstrated abnormal ocular plethysmographic recordings, and of those, nine had dysrhythmias associated with significant deficits of ocular perfusion. Five patients whose recordings were technically suitable for publication are presented to demonstrate the bizarre ocular plethysmographic recordings seen during the dysrhythmic cycle.

  9. 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.

  10. The human milk oligosaccharide 2′-fucosyllactose attenuates the severity of experimental necrotising enterocolitis by enhancing mesenteric perfusion in the neonatal intestine

    PubMed Central

    Good, Misty; Sodhi, Chhinder P.; Yamaguchi, Yukihiro; Jia, Hongpeng; Lu, Peng; Fulton, William B.; Martin, Laura Y.; Prindle, Thomas; Nino, Diego F.; Zhou, Qinjie; Ma, Congrong; Ozolek, John A.; Buck, Rachael H.; Goehring, Karen C.; Hackam, David J.

    2016-01-01

    Necrotising enterocolitis (NEC) is a common disease in premature infants characterised by intestinal ischaemia and necrosis. The only effective preventative strategy against NEC is the administration of breast milk, although the protective mechanisms remain unknown. We hypothesise that an abundant human milk oligosaccharide (HMO) in breast milk, 2′-fucosyllactose (2′FL), protects against NEC by enhancing intestinal mucosal blood flow, and we sought to determine the mechanisms underlying this protection. Administration of HMO-2′FL protected against NEC in neonatal wild-type mice, resulted in a decrease in pro-inflammatory markers and preserved the small intestinal mucosal architecture. These protective effects occurred via restoration of intestinal perfusion through up-regulation of the vasodilatory molecule endothelial nitric oxide synthase (eNOS), as administration of HMO-2′FL to eNOS-deficient mice or to mice that received eNOS inhibitors did not protect against NEC, and by 16S analysis HMO-2′FL affected the microbiota of the neonatal mouse gut, although these changes do not seem to be the primary mechanism of protection. Induction of eNOS by HMO-2′FL was also observed in cultured endothelial cells, providing a link between eNOS and HMO in the endothelium. These data demonstrate that HMO-2′FL protects against NEC in part through maintaining mesenteric perfusion via increased eNOS expression, and suggest that the 2′FL found in human milk may be mediating some of the protective benefits of breast milk in the clinical setting against NEC. PMID:27609061

  11. Primary mucosal melanomas: a comprehensive review

    PubMed Central

    Mihajlovic, Marija; Vlajkovic, Slobodan; Jovanovic, Predrag; Stefanovic, Vladisav

    2012-01-01

    Primary mucosal melanomas arise from melanocytes located in mucosal membranes lining respiratory, gastrointestinal and urogenital tract. Although a majority of mucosal melanomas originate from the mucosa of the nasal cavity and accessory sinuses, oral cavity, anorectum, vulva and vagina, they can arise in almost any part of mucosal membranes. Most of mucosal melanomas occur in occult sites, which together with the lack of early and specific signs contribute to late diagnosis, and poor prognosis. Because of their rareness the knowledge about their pathogenesis and risk factors is insufficient, and also there are not well established protocols for staging and treatment of mucosal melanomas. Surgery is the mainstay of treatment, with trends toward more conservative treatment since radical surgery did not show an advantage for survival. Radiotherapy can provide better local control in some locations, but did not show improvement in survival. There is no effective systemic therapy for these aggressive tumors. Compared with cutaneous and ocular melanoma, mucosal melanomas have lowest percent of five-year survival. Recently revealed molecular changes underlying mucosal melanomas offer new hope for development of more effective systemic therapy for mucosal melanomas. Herein we presented a comprehensive review of various locations of primary melanoma along mucosal membranes, their epidemiological and clinical features, and treatment options. We also gave a short comparison of some characteristics of cutaneous and mucosal melanomas. PMID:23071856

  12. The Mucosal Immune System of Teleost Fish

    PubMed Central

    Salinas, Irene

    2015-01-01

    Teleost fish possess an adaptive immune system associated with each of their mucosal body surfaces. Evidence obtained from mucosal vaccination and mucosal infection studies reveal that adaptive immune responses take place at the different mucosal surfaces of teleost. The main mucosa-associated lymphoid tissues (MALT) of teleosts are the gut-associated lymphoid tissue (GALT), skin-associated lymphoid tissue (SALT), the gill-associated lymphoid tissue (GIALT) and the recently discovered nasopharynx-associated lymphoid tissue (NALT). Teleost MALT includes diffuse B cells and T cells with specific phenotypes different from their systemic counterparts that have co-evolved to defend the microbe-rich mucosal environment. Both B and T cells respond to mucosal infection or vaccination. Specific antibody responses can be measured in the gills, gut and skin mucosal secretions of teleost fish following mucosal infection or vaccination. Rainbow trout studies have shown that IgT antibodies and IgT+ B cells are the predominant B cell subset in all MALT and respond in a compartmentalized manner to mucosal infection. Our current knowledge on adaptive immunity in teleosts is limited compared to the mammalian literature. New research tools and in vivo models are currently being developed in order to help reveal the great intricacy of teleost mucosal adaptive immunity and help improve mucosal vaccination protocols for use in aquaculture. PMID:26274978

  13. [Melphalan pharmacokinetics during isolated limb regional perfusion in patients with skin melanoma and soft tissue sarcoma].

    PubMed

    Gafton, G I; Senchik, K Yu; Petrov, V G; V V Semiglazov; N V Tatyanicheva; V G Bespalov; Semiletova, Yu V; Gafton, I G; Zinoviev, G V; Kireeva, G S

    2015-01-01

    The study of pharmacokinetics of melphalan in the perfusate and blood plasma during isolated limb regional perfusion (ILRP) was carried out in patients with melanoma (n=21) and soft tissue sarcoma (n = 24). Melphalan was administered as 10 mg/l for a lower extremity and 13 mg/l for a upper extremity. Quantification of melphalan in perfusate and blood samples was performed by means of liquid chromatography/tandem mass spectrometry. 30 samples of the perfusate and 27 venous blood samples were analyzed. During the first 5 minutes of ILRP concentration of melphalan in the perfusate decreased to 13.2% of the initial value, and by the end of perfusion (60 minutes) it was 3.3%. The amount of melphalan in the blood plasma of the patients by the end of ILRP wasn't higher than 1.6% from the administered dose. That demonstrates minor systemic absorption of the drug during ILRP. Moreover melphalan concentration in the blood plasma during the perfusion was in average 0.015-0.223 mg/l which is significantly lower compared to the blood plasma concentrations after intravenous administration of melphalan. Thus ILRP procedure provided 97% of the melphalan dose accumulation in the soft tissues of a limb and in tumor tissues. Also pharmacokinetic advantage of melphalan over systemic administration of the drug was shown.

  14. Cold Crystalloid Perfusion Provides Cardiac Preservation Superior to Cold Storage for Donation After Circulatory Death.

    PubMed

    Choong, Jonathan W; Ou, Ruchong; Lim, Yi Wee; Rosenfeldt, Franklin L

    2016-03-01

    We previously showed that donation after circulatory death (DCD) canine hearts can be resuscitated if perfused with warm blood. However, clinical application of this technique is complex and difficult. We have developed a simplified system of cold crystalloid perfusion and compared it with standard cold storage for DCD heart preservation. Anesthetized greyhounds underwent 30 minutes DCD by withdrawal of ventilation followed by assignment to either 4 hours of perfusion (n = 6) or cold storage (n = 7). Nonpreserved hearts (n = 5) served as a normal reference group. Perfusion hearts were reperfused with a protective solution then perfused for 4 hours with a novel oxygenated, nutrient-containing solution at 20 mL/min at 4°C to 10°C. Cold storage hearts were flushed with St Thomas' cardioplegic solution and stored in ice. After preservation, the recovery of the hearts was assessed on a blood-perfused working heart rig. During preservation, perfusion hearts consumed oxygen (0.09 ± 0.01 mL/100 g per minute) and showed decreasing lactate production in the perfusate (initial: 0.031 ± 0.004 vs final: 0.007 ± 0.002 mmol/min; P = 0.001). After preservation, compared to cold storage hearts, perfusion hearts had higher cardiac output (P = 0.004), LV dP/dt max (P = 0.003) and myocardial oxygen efficiency (P = 0.01), with lower blood perfusate lactate (P = 0.007). Hemodynamic values of perfused hearts reached 60% or more those in the normal reference group. Continuous cold crystalloid perfusion in a canine model of DCD: (1) facilitates aerobic metabolism and resuscitates the DCD heart, (2) provides functional and metabolic recovery superior to cold storage, (3) shows promise for improved clinical preservation of DCD and marginal donor hearts.

  15. Perfusion Based Cell Culture Chips

    NASA Astrophysics Data System (ADS)

    Heiskanen, A.; Emnéus, J.; Dufva, M.

    Performing cell culture in miniaturized perfusion chambers gives possibilities to experiment with cells under near in vivo like conditions. In contrast to traditional batch cultures, miniaturized perfusion systems provide precise control of medium composition, long term unattended cultures and tissue like structuring of the cultures. However, as this chapter illustrates, many issues remain to be identified regarding perfusion cell culture such as design, material choice and how to use these systems before they will be widespread amongst biomedical researchers.

  16. Australian and New Zealand Perfusion Survey: Management and Procedure

    PubMed Central

    Tuble, Sigrid C.; Willcox, Timothy W.; Baker, Robert A.

    2009-01-01

    Abstract: In this report, we will discuss management and procedural aspects of perfusion practice. This report allows us to compare and contrast recent trends and changes in perfusion with historic practices. A survey comprised of 233 single-answer and 12 open-ended questions was sent by e-mail to senior perfusionists or individuals in charge of perfusion in 40 hospital groups. The survey encompasses a review of the perfusion practices for the calendar year of 2003, and respondents were required to answer the survey based on the predominant practice in their institutions. Standard management of routine adult cardiopulmonary bypass (CPB) in 2003 consisted of perfusion strategies that achieved a target temperature of 32.0°C (range, 28.0–35.0°C), a flow index of 2.4 L/min/m2 (range, 1.6–3.0 L/min/m2) during normothermia and 1.8 L/min/m2 (range, 1.2–3.0 L/min/m2) during hypothermia, and a pressure during CPB between 50 (range, 30–65 mmHg) and 70 mmHg (range, 60–95 mmHg). Myocardial protection with blood cardioplegia was used in 77% of the 20,688 CPB cases, whereas in 53% cases, cardiotomy blood was never processed. Pre-operatively, 76% of perfusion groups assessed their patients (21% directly with the patient), and 85% responded that perfusionists performed or participated in a formal pre-bypass checklist. The majority of the perfusion groups used a handwritten perfusion record (62%), 12% used an electronic perfusion record, and 26% used both, whereas more than one half of the groups were involved in quality assurance (79%), incident reporting (74%), audits (62%), research (53%), participating in interdisciplinary meetings (53%), and morbidity and mortality meetings (65%). Only 26% conducted formal perfusion team meetings. This report outlines the status of clinical management and procedural performance for perfusion practices in Australia and New Zealand in 2003. Awareness of these trends will allow perfusionists to assess both individual practices and

  17. Use of Inert Gases to Study the Interaction of Blood Flow and Diffusion during Passive Absorption from the Gastrointestinal Tract of the Rat

    PubMed Central

    Levitt, Michael D.; Levitt, David G.

    1973-01-01

    Measurement of the relative absorption rates of inert gases (H2, He, CH4, SF6, and 133Xe) was used to investigate the interaction between diffusion and blood flow during passive absorption from the stomach, small bowel, and colon of the rat. If uptake is blood flow limited, the gases should be absorbed in proportion to their solubilities in blood, but if diffusion limited, uptake should be proportional to the diffusion rate of the gases in mucosal tissues. The observed absorption data were fitted to a series of models of interaction between perfusion and diffusion. A simple model accurately predicted the absorption rates of the gases from all segments of bowel. In this model, gas is absorbed into two distinct blood flows: one which flows in proximity to the lumen and completely equilibrates with the lumen, and a second which is sufficiently rapid and distant from the lumen that its gas uptake is entirely diffusion limited. The fraction of the total absorption attributable to the equilibrating flow can be readily calculated and equalled 93%, 77%, and 33% for the small bowel, colon, and stomach, respectively. Thus the rate of passive absorption of gases from the small bowel is limited almost entirely by the blood flow to the mucosa, and absorption from the stomach is largely limited by the diffusion rate of the gases. The flow which equilibrates with the lumen can be quantitated, and this flow may provide a useful measure of “effective” mucosal blood flow. Images PMID:4719667

  18. A comparative study of lingual mucosal graft urethroplasty with buccal mucosal graft urethroplasty in urethral stricture disease: An institutional experience

    PubMed Central

    Pal, Dilip Kumar; Gupta, Depak Kumar; Ghosh, Bastab; Bera, Malay Kumar

    2016-01-01

    Aims: A prospective study to compare the outcomes of lingual versus buccal mucosal graft urethroplasty in patients with long segment anterior urethral strictures disease. Materials and Methods: The study included 30 patients for buccal mucosal graft urethroplasty (group I) and 30 patients for lingual mucosal graft urethroplasty (group II) for treatment of long segment (>3 cm) incomplete anterior urethral stricture disease using single-stage dorsal onlay free oral mucosal graft urethroplasty by Barbagli's technique between February 2013 to September 2014. All patients underwent complete evaluation of the stricture including inspection of the oral cavity. Results: The results of urethroplasty in between two group were not significant (P > 0.05) in terms of Qmax (P = 0.63), mean postoperative AUA symptom score (P = 0.83), operative time (P = 0.302) intra operative blood loss (P = 0.708), duration of postoperative hospitalization (P = 0.83), but slurring of speech complications was seen in group II, but not in group I. Long-term complications of salivary disturbance, tightness of the mouth, persistent pain at graft site, perioral numbness, seen only in group I (BMGU). Conclusion: LMG urethroplasty is an excellent alternative to BMG urethroplasty with comparable results of urethroplasty and minimal donor site complications. PMID:27141184

  19. Comparison of computed tomography perfusion and magnetic resonance imaging perfusion-diffusion mismatch in ischemic stroke.

    PubMed

    Campbell, Bruce C V; Christensen, Søren; Levi, Christopher R; Desmond, Patricia M; Donnan, Geoffrey A; Davis, Stephen M; Parsons, Mark W

    2012-10-01

    Perfusion imaging has the potential to select patients most likely to respond to thrombolysis. We tested the correspondence of computed tomography perfusion (CTP)-derived mismatch with contemporaneous perfusion-diffusion magnetic resonance imaging (MRI). Acute ischemic stroke patients 3 to 6 hours after onset had CTP and perfusion-diffusion MRI within 1 hour, before thrombolysis. Relative cerebral blood flow (relCBF) and time to peak of the deconvolved tissue residue function (Tmax) were calculated. The diffusion lesion (diffusion-weighted imaging) was registered to the CTP slabs and manually outlined to its maximal visual extent. Volumetric accuracy of CT-relCBF infarct core (compared with diffusion-weighted imaging) was tested. To reduce false-positive low CBF regions, relCBF core was restricted to voxels within a relative time-to-peak (relTTP) >4 seconds for lesion region of interest. The MR-Tmax >6 seconds perfusion lesion was automatically segmented and registered to CTP. Receiver-operating characteristic analysis determined the optimal CT-Tmax threshold to match MR-Tmax >6 seconds. Agreement of these CT parameters with MR perfusion-diffusion mismatch in coregistered slabs was assessed (mismatch ratio >1.2, absolute mismatch >10 mL, infarct core <70 mL). In analysis of 49 patients (mean onset to CT, 213 minutes; mean CT to MR, 31 minutes), constraining relCBF <31% within the automated relTTP perfusion lesion region of interest reduced the median magnitude of volumetric error (vs diffusion-weighted imaging) from 47.5 mL to 15.8 mL (P<0.001). The optimal CT-Tmax threshold to match MR-Tmax >6 seconds was 6.2 seconds (95% confidence interval, 5.6-7.3 seconds; sensitivity, 91%; specificity, 70%; area under the curve, 0.87). Using CT-Tmax >6 seconds "penumbra" and relTTP-constrained relCBF "core," CT-based and MRI-based mismatch status was concordant in 90% (kappa=0.80). Quantitative CTP mismatch classification using relCBF and Tmax is similar to perfusion

  20. NOTE: Estimating perfusion using microCT to locate microspheres

    NASA Astrophysics Data System (ADS)

    Marxen, M.; Paget, C.; Yu, L. X.; Henkelman, R. M.

    2006-01-01

    The injection of microspheres into the blood stream has been a common method to measure the spatial distribution of blood flow (perfusion). A technique to conduct this kind of measurement in small animal organs is presented using silver-coated microspheres with a diameter of 16 µm and high-resolution computed tomography (microCT) to detect individual microspheres. Phantom experiments demonstrate the detectability of individual spheres. The distribution of microspheres within a rat heart is given as an example. Using non-destructive, three-dimensional imaging for microsphere detection avoids the cumbersome dissection of the organ into samples or slices and their subsequent registration. The detection of individual spheres allows high-resolution measurements of perfusion and arbitrary definition of regions of interest. These, in turn, allow for accurate statistical analysis of perfusion such as relative dispersion curves.

  1. Regional pulmonary perfusion following human heart-lung transplantation

    SciTech Connect

    Lisbona, R.; Hakim, T.S.; Dean, G.W.; Langleben, D.; Guerraty, A.; Levy, R.D. )

    1989-08-01

    Ventilation and perfusion scans were obtained in six subjects who had undergone heart-lung transplantation with consequent denervation of the cardiopulmonary axis. Two of the subjects had developed obliterative bronchiolitis, which is believed to be a form of chronic rejection. Their pulmonary function tests demonstrated airflow obstruction and their scintigraphic studies were abnormal. In the remaining four subjects without obstructive airways disease, ventilation and planar perfusion scans were normal. Single photon emission computed tomography imaging of pulmonary perfusion in these patients revealed a layered distribution of blood flow indistinguishable from that of normal individuals. It is concluded that neurogenic mechanisms have little influence on the pattern of local pulmonary blood flow at rest.

  2. Cyclo-oxygenase isozymes in mucosal ulcerogenic and functional responses following barrier disruption in rat stomachs

    PubMed Central

    Hirata, Takuya; Ukawa, Hideki; Yamakuni, Hisashi; Kato, Shinichi; Takeuchi, Koji

    1997-01-01

    We examined the effects of selective and nonselective cyclo-oxygenase (COX) inhibitors on various functional changes in the rat stomach induced by topical application of taurocholate (TC) and investigated the preferential role of COX isozymes in these responses. Rat stomachs mounted in ex vivo chambers were perfused with 50 mM HCl and transmucosal potential difference (p.d.), mucosal blood flow (GMBF), luminal acid loss and luminal levels of prostaglandin E2 (PGE2) were measured before, during and after exposure to 20 mM TC. Mucosal application of TC in control rats caused a reduction in p.d., followed by an increase of luminal acid loss and GMBF, and produced only minimal damage in the mucosa 2 h later. Pretreatment with indomethacin (10 mg kg−1, s.c.), a nonselective COX-1 and COX-2 inhibitor, attenuated the gastric hyperaemic response caused by TC without affecting p.d. and acid loss, resulting in haemorrhagic lesions in the mucosa. In contrast, selective COX-2 inhibitors, such as NS-398 and nimesulide (10 mg kg−1, s.c.), had no effect on any of the responses induced by TC and did not cause gross damage in the mucosa. Luminal PGE2 levels were markedly increased during and after exposure to TC and this response was significantly inhibited by indomethacin but not by either NS-398 or nimesulide. The expression of COX-1-mRNA was consistently detected in the gastric mucosa before and after TC treatment, while a faint expression of COX-2-mRNA was detected only 2 h after TC treatment. Both NS-398 and nimesulide significantly suppressed carrageenan-induced rat paw oedema, similar to indomethacin. These results confirmed a mediator role for prostaglandins in the gastric hyperaemic response following TC-induced barrier disruption, and suggest that COX-1 but not COX-2 is a key enzyme in maintaining ‘housekeeping' functions in the gastric mucosa under both normal and adverse conditions. PMID:9351500

  3. Cryopreservation of Human Mucosal Leukocytes

    PubMed Central

    Shu, Zhiquan; Levy, Claire N.; Ferre, April L.; Hartig, Heather; Fang, Cifeng; Lentz, Gretchen; Fialkow, Michael; Kirby, Anna C.; Adams Waldorf, Kristina M.; Veazey, Ronald S.; Germann, Anja; von Briesen, Hagen; McElrath, M. Juliana; Dezzutti, Charlene S.; Sinclair, Elizabeth; Baker, Chris A. R.; Shacklett, Barbara L.; Gao, Dayong; Hladik, Florian

    2016-01-01

    Background Understanding how leukocytes in the cervicovaginal and colorectal mucosae respond to pathogens, and how medical interventions affect these responses, is important for developing better tools to prevent HIV and other sexually transmitted infections. An effective cryopreservation protocol for these cells following their isolation will make studying them more feasible. Methods and Findings To find an optimal cryopreservation protocol for mucosal mononuclear leukocytes, we compared cryopreservation media and procedures using human vaginal leukocytes and confirmed our results with endocervical and colorectal leukocytes. Specifically, we measured the recovery of viable vaginal T cells and macrophages after cryopreservation with different cryopreservation media and handling procedures. We found several cryopreservation media that led to recoveries above 75%. Limiting the number and volume of washes increased the fraction of cells recovered by 10–15%, possibly due to the small cell numbers in mucosal samples. We confirmed that our cryopreservation protocol also works well for both endocervical and colorectal leukocytes. Cryopreserved leukocytes had slightly increased cytokine responses to antigenic stimulation relative to the same cells tested fresh. Additionally, we tested whether it is better to cryopreserve endocervical cells on the cytobrush or in suspension. Conclusions Leukocytes from cervicovaginal and colorectal tissues can be cryopreserved with good recovery of functional, viable cells using several different cryopreservation media. The number and volume of washes has an experimentally meaningful effect on the percentage of cells recovered. We provide a detailed, step-by-step protocol with best practices for cryopreservation of mucosal leukocytes. PMID:27232996

  4. Mucosal immunology of food allergy.

    PubMed

    Berin, M Cecilia; Sampson, Hugh A

    2013-05-06

    Food allergies are increasing in prevalence at a higher rate than can be explained by genetic factors, suggesting a role for as yet unidentified environmental factors. In this review, we summarize the state of knowledge about the healthy immune response to antigens in the diet and the basis of immune deviation that results in immunoglobulin E (IgE) sensitization and allergic reactivity to foods. The intestinal epithelium forms the interface between the external environment and the mucosal immune system, and emerging data suggest that the interaction between intestinal epithelial cells and mucosal dendritic cells is of particular importance in determining the outcome of immune responses to dietary antigens. Exposure to food allergens through non-oral routes, in particular through the skin, is increasingly recognized as a potentially important factor in the increasing rate of food allergy. There are many open questions on the role of environmental factors, such as dietary factors and microbiota, in the development of food allergy, but data suggest that both have an important modulatory effect on the mucosal immune system. Finally, we discuss recent developments in our understanding of immune mechanisms of clinical manifestations of food allergy. New experimental tools, particularly in the field of genomics and the microbiome, are likely to shed light on factors responsible for the growing clinical problem of food allergy.

  5. Cryopreservation of Human Mucosal Leukocytes.

    PubMed

    Hughes, Sean M; Shu, Zhiquan; Levy, Claire N; Ferre, April L; Hartig, Heather; Fang, Cifeng; Lentz, Gretchen; Fialkow, Michael; Kirby, Anna C; Adams Waldorf, Kristina M; Veazey, Ronald S; Germann, Anja; von Briesen, Hagen; McElrath, M Juliana; Dezzutti, Charlene S; Sinclair, Elizabeth; Baker, Chris A R; Shacklett, Barbara L; Gao, Dayong; Hladik, Florian

    2016-01-01

    Understanding how leukocytes in the cervicovaginal and colorectal mucosae respond to pathogens, and how medical interventions affect these responses, is important for developing better tools to prevent HIV and other sexually transmitted infections. An effective cryopreservation protocol for these cells following their isolation will make studying them more feasible. To find an optimal cryopreservation protocol for mucosal mononuclear leukocytes, we compared cryopreservation media and procedures using human vaginal leukocytes and confirmed our results with endocervical and colorectal leukocytes. Specifically, we measured the recovery of viable vaginal T cells and macrophages after cryopreservation with different cryopreservation media and handling procedures. We found several cryopreservation media that led to recoveries above 75%. Limiting the number and volume of washes increased the fraction of cells recovered by 10-15%, possibly due to the small cell numbers in mucosal samples. We confirmed that our cryopreservation protocol also works well for both endocervical and colorectal leukocytes. Cryopreserved leukocytes had slightly increased cytokine responses to antigenic stimulation relative to the same cells tested fresh. Additionally, we tested whether it is better to cryopreserve endocervical cells on the cytobrush or in suspension. Leukocytes from cervicovaginal and colorectal tissues can be cryopreserved with good recovery of functional, viable cells using several different cryopreservation media. The number and volume of washes has an experimentally meaningful effect on the percentage of cells recovered. We provide a detailed, step-by-step protocol with best practices for cryopreservation of mucosal leukocytes.

  6. Mucosal Immunology of Food Allergy

    PubMed Central

    Berin, M. Cecilia; Sampson, Hugh A.

    2013-01-01

    Food allergies are increasing in prevalence at a higher rate than can be explained by genetic factors, suggesting a role for as yet unidentified environmental factors. In this review, we summarize the state of knowledge about the healthy immune response to antigens in the diet and the basis of immune deviation that results in IgE sensitization and allergic reactivity to foods. The intestinal epithelium forms the interface between the external environment and the mucosal immune system, and emerging data suggest that the interaction between intestinal epithelial cells and mucosal dendritic cells is of particular importance in determining the outcome of immune responses to dietary antigens. Exposure to food allergens through non-oral routes, in particular through the skin, is increasingly recognized as a potentially important factor in the increasing rate of food allergy. There are many open questions on the role of environmental factors such as dietary factors and microbiota in the development of food allergy, but data suggest that both have an important modulatory effect on the mucosal immune system. Finally, we discuss recent developments in our understanding of immune mechanisms of clinical manifestations of food allergy. New experimental tools, particularly in the field of genomics and microbiome, are likely to shed light on factors responsible for the growing clinical problem of food allergy. PMID:23660362

  7. Vestibuloplasty: allograft versus mucosal graft.

    PubMed

    Hashemi, H M; Parhiz, A; Ghafari, S

    2012-04-01

    The aim of the present study was to compare the application of alloderm and mucosal graft for vestibuloplasty. This randomized controlled trial with split mouth design was carried out on 20 edentulous patients. Patients underwent vestibuloplasty surgery with the Clark technique. Half of the prepared bed in each patient was covered with alloderm and the other half with mucosal graft. Vestibule depth (width of fixed tissue) and relapse in the two sides immediately after surgery, and 1, 3 and 6 months after surgery were measured and compared. Statistical analysis was carried out using the Kolmogorov-Smirnov, Student's paired t and Friedman tests. The width of the fixed tissue in the alloderm graft at 1, 3 and 6 month intervals was significantly lower than that in the autograft (P<0.05). The difference in relapse between the two grafts was not statistically significant at any time. The results of the study suggest that alloderm is as effective as mucosal grafts in vestibuloplasty. Copyright © 2011 International Association of Oral and Maxillofacial Surgeons. All rights reserved.

  8. 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.

  9. Whole-Brain Computed Tomographic Perfusion Imaging in Acute Cerebral Venous Sinus Thrombosis

    PubMed Central

    Mokin, Maxim; Ciambella, Chelsey C.; Masud, Muhammad W.; Levy, Elad I.; Snyder, Kenneth V.; Siddiqui, Adnan H.

    2016-01-01

    Background Acute cerebral venous sinus thrombosis (VST) can be difficult to diagnose because of its diverse clinical presentation. The utility of perfusion imaging for diagnosing VST is not well understood. Summary We retrospectively reviewed cases of acute VST in patients who underwent whole-brain (320-detector-row) computed tomographic (CT) perfusion imaging in combination with craniocervical CT venography. Perfusion maps that were analyzed included cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time, and time to peak. Among the 10 patients with acute VST included in this study, 9 had perfusion abnormalities. All perfusion abnormalities were localized in areas adjacent to the occluded sinus and did not match typical anterior or posterior circulation arterial territories. Bilateral perfusion deficits were seen in 4 cases. In 2 cases, parenchymal hemorrhage was diagnosed on noncontrast CT imaging; in those cases, focal CBV and CBF were reduced. Key Messages Whole-brain CT perfusion imaging with 320-detector-row scanners can further assist in establishing the diagnosis of VST by detecting perfusion abnormalities corresponding to venous and not arterial territories. CT perfusion could assist in the differentiation between focal reversible changes, such as those caused by vasogenic edema, and irreversible changes due to infarction. PMID:27051406

  10. The influence of decompressive craniectomy for major stroke on early cerebral perfusion.

    PubMed

    Slotty, Philipp Jörg; Kamp, Marcel Alexander; Beez, Thomas; Beenen, Henrieke; Steiger, Hans-Jakob; Turowski, Bernd; Hänggi, Daniel

    2015-07-01

    Multiple trials have shown improved survival and functional outcome in patients treated with decompressive craniectomy (DC) for brain swelling following major stroke. It has been assumed that decompression induces an improvement in cerebral perfusion. This observational study directly measured cerebral perfusion before and after decompression. Sixteen patients were prospectively examined with perfusion CT within 6 hours prior to surgery and 12 hours after surgery. Preoperative and postoperative perfusion measurements were compared and correlated. Following DC there was a significant increase in cerebral blood flow in all measured territories and additionally an increase in cerebral blood volume in the penumbra (p = 0.03). These changes spread as far as the contralateral hemisphere. No significant changes in mean transit time or Tmax (time-to-peak residue function) were observed. The presurgical perfusion abnormalities likely reflected local pressure-induced hypoperfusion with impaired autoregulation. The improvement in perfusion after decompression implied an increase in perfusion pressure, likely linked to partial restoration of autoregulation. The increase in perfusion that was observed might partially be responsible for improved clinical outcome following decompressive surgery for major stroke. The predictive value of perfusion CT on outcome needs to be evaluated in larger trials.

  11. Haemoculture of Leishmania (Viannia) braziliensis from two cases of mucosal leishmaniasis: re-examination of haematogenous dissemination.

    PubMed

    Martinez, J E; Alba; Arias, L; Escobar, M A; Saravia, N G

    1992-01-01

    Leishmania parasites were isolated from peripheral blood leucocytes of 2 patients with mucosal disease among a total of 23 parasitologically confirmed cases of leishmaniasis. One had had mucosal leishmaniasis for 4 years and active pulmonary tuberculosis was also diagnosed. The other patient presented a cutaneous lesion on his right leg of 3 months duration and asymptomatic mucosal involvement. He had received intravenous antimonials before isolation of parasites. Both patients had positive indirect fluorescent antibody and Montenegro skin tests. L. (Viannia) braziliensis was isolated from both patients. This culture of parasites from leucocytes provided direct evidence for metastatic spread of Leishmania via the blood.

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

    PubMed Central

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

    2016-01-01

    Preservation of myocardial perfusion during surgery is particularly important in patients with increased risk for perioperative complications, such as diabetes. Volatile anesthetics, like sevoflurane, have cardiodepressive effects and may aggravate cardiovascular complications. We investigated the effect of sevoflurane on myocardial perfusion and function in prediabetic rats. Rats were fed a western diet (WD; n = 18) or control diet (CD; n = 18) for 8 weeks and underwent (contrast) echocardiography to determine perfusion and function during baseline and sevoflurane exposure. Myocardial perfusion was estimated based on the product of microvascular filling velocity and blood volume. WD-feeding resulted in a prediabetic phenotype characterized by obesity, hyperinsulinemia, hyperlipidemia, glucose intolerance, and hyperglycemia. At baseline, WD-feeding impaired myocardial perfusion and systolic function compared to CD-feeding. Exposure of healthy rats to sevoflurane increased the microvascular filling velocity without altering myocardial perfusion but impaired systolic function. In prediabetic rats, sevoflurane did also not affect myocardial perfusion; however, it further impaired systolic function. Diet-induced prediabetes is associated with impaired myocardial perfusion and function in rats. While sevoflurane further impaired systolic function, it did not affect myocardial perfusion in prediabetic rats. Our findings suggest that sevoflurane anesthesia leads to uncoupling of myocardial perfusion and function, irrespective of the metabolic state. PMID:26824042

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

    PubMed

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

    2016-01-01

    Preservation of myocardial perfusion during surgery is particularly important in patients with increased risk for perioperative complications, such as diabetes. Volatile anesthetics, like sevoflurane, have cardiodepressive effects and may aggravate cardiovascular complications. We investigated the effect of sevoflurane on myocardial