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Sample records for mucosal blood perfusion

  1. 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.

  2. 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

  3. 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. PMID:23958351

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. Evaluation of intestinal absorption and mucosal toxicity using two promoters. II. Rat instillation and perfusion studies.

    PubMed

    Maher, Sam; Wang, Xuexuan; Bzik, Victoria; McClean, Siobhan; Brayden, David J

    2009-11-01

    We compared the effectiveness of two absorption promoters, sodium caprate (C(10)) and melittin, in increasing the bioavailability (F) of poorly absorbed paracellular flux markers across the intestinal mucosae of rats in situ, together with examination of their effects on morphology. C(10) (100 mM) and melittin (50 microM) significantly increased absorption of FITC-dextran-4 kDa (FD4) following jejunal and colonic instillations. F of FD4 following jejunal instillations with C(10) was increased from 0.07% to 2.3%, while it was increased from 0.07% to 0.53% in the presence of melittin. F of FD4 following colonic instillations with C(10) was increased from 1% to 33% while melittin increased it from 1% to 7%. F of FD70 was unchanged in colonic instillations in the presence of either of the two agents, indicating size limitations of the permeability enhancement effects. In rat jejunal perfusions, C(10) (50 mM) and melittin (50 microM) significantly increased [(14)C]-mannitol permeability by 9- and 1.9-fold respectively. C(10) was more effective than melittin in increasing fluxes in all models. Histology of intestinal sections exposed to either promoter showed mild mucosal damage at those concentrations effective at promoting absorption. Electron microscopy revealed epithelial cell damage induced by both enhancers accompanied by truncation of microvilli, and sloughing. Overall, both melittin and C(10) improved bioavailability of polar sugars across the jejunum and colon of rats in situ, which was associated with some degree of mucosal damage. PMID:19664704

  11. Reflectance Photoplethysmography as Noninvasive Monitoring of Tissue Blood Perfusion.

    PubMed

    Abay, Tomas Ysehak; Kyriacou, Panayiotis A

    2015-09-01

    In the last decades, photoplethysmography (PPG) has been used as a noninvasive technique for monitoring arterial oxygen saturation by pulse oximetry (PO), whereas near-infrared spectroscopy (NIRS) has been employed for monitoring tissue blood perfusion. While NIRS offers more parameters to evaluate oxygen delivery and consumption in deep tissues, PO only assesses the state of oxygen delivery. For a broader assessment of blood perfusion, this paper explores the utilization of dual-wavelength PPG by using the pulsatile (ac) and continuous (dc) PPG for the estimation of arterial oxygen saturation (SpO2) by conventional PO. Additionally, the Beer-Lambert law is applied to the dc components only for the estimation of changes in deoxyhemoglobin (HHb), oxyhemoglobin (HbO2), and total hemoglobin (tHb) as in NIRS. The system was evaluated on the forearm of 21 healthy volunteers during induction of venous occlusion (VO) and total occlusion (TO). A reflectance PPG probe and NIRS sensor were applied above the brachioradialis, PO sensors were applied on the fingers, and all the signals were acquired simultaneously. While NIRS and forearm SpO2 indicated VO, SpO2 from the finger did not exhibit any significant drop from baseline. During TO, all the indexes indicated the change in blood perfusion. HHb, HbO2, and tHb changes estimated by PPG presented high correlation with the same parameters obtained by NIRS during VO (r(2) = 0.960, r(2) = 0.821, and r(2) = 0.974, respectively) and during TO (r(2) = 0.988, r(2) = 0.940, and r(2) = 0.938, respectively). The system demonstrated the ability to extract valuable information from PPG signals for a broader assessment of tissue blood perfusion. PMID:25838515

  12. Tonometry revisited: perfusion-related, metabolic, and respiratory components of gastric mucosal acidosis in acute cardiorespiratory failure.

    PubMed

    Jakob, Stephan M; Parviainen, Ilkka; Ruokonen, Esko; Kogan, Alexander; Takala, Jukka

    2008-05-01

    Mucosal pH (pHi) is influenced by local perfusion and metabolism (mucosal-arterial pCO2 gradient, DeltapCO2), systemic metabolic acidosis (arterial bicarbonate), and respiration (arterial pCO2). We determined these components of pHi and their relation to outcome during the first 24 h of intensive care. We studied 103 patients with acute respiratory or circulatory failure (age, 63+/-2 [mean+/-SEM]; Acute Physiology and Chronic Health Evaluation II score, 20+/-1; Sequential Organ Failure Assessment score, 8+/-0). pHi, and the effects of bicarbonate and arterial and mucosal pCO2 on pHi, were assessed at admission, 6, and 24 h. pHi was reduced (at admission, 7.27+/-0.01) due to low arterial bicarbonate and increased DeltapCO2. Low pHi (<7.32) at admission (n=58; mortality, 29% vs. 13% in those with pHi>or=7.32 at admission; P=0.061) was associated with an increased DeltapCO2 in 59% of patients (mortality, 47% vs. 4% for patients with low pHi and normal DeltapCO2; P=0.0003). An increased versus normal DeltapCO2, regardless of pHi, was associated with increased mortality at admission (51% vs. 5%; P<0.0001; n=39) and at 6 h (34% vs. 13%; P=0.016; n=45). A delayed normalization or persistently low pHi (n=47) or high DeltapCO2 (n=25) was associated with high mortality (low pHi [34%] vs. high DeltapCO2 [60%]; P=0.046). In nonsurvivors, hypocapnia increased pHi at baseline, 6, and 24 h (all Pperfusion and is associated with high mortality. Arterial bicarbonate contributes more to pHi than the DeltapCO2 but is not associated with mortality. Hyperventilation partly masks mucosal acidosis. Inadequate tissue perfusion may persist despite stable hemodynamics and contributes to poor outcome. PMID:18004228

  13. Noninvasive Blood Perfusion Measurements of an Isolated Rat Liver and an Anesthetized Rat Kidney

    PubMed Central

    Mudaliar, Ashvinikumar V.; Ellis, Brent E.; Ricketts, Patricia L.; Lanz, Otto I.; Lee, Charles Y.; Diller, Thomas E.; Scott, Elaine P.

    2008-01-01

    A simple, cost effective, and noninvasive blood perfusion system is tested in animal models. The system uses a small sensor to measure the heat transfer response to a thermal event (convective cooling) imposed on the tissue surface. Heat flux data are compared with a mathematical model of the tissue to estimate both blood perfusion and thermal contact resistance between the tissue and the probe. The perfusion system was evaluated for repeatability and sensitivity using isolated rat liver and exposed rat kidney tests. Perfusion in the isolated liver tests was varied by controlling the flow of the perfusate into the liver, and the perfusion in the exposed kidney tests was varied by temporarily occluding blood flow through the renal artery and vein. The perfusion estimated by the convective perfusion probe was in good agreement with that of the metered flow of the perfusate into the liver model. The liver tests indicated that the probe can be used to detect small changes in perfusion (0.005 ml/ml/s). The probe qualitatively tracked the changes in the perfusion in the kidney model due to occlusion of the renal artery and vein. PMID:19045542

  14. Endoscopic measurements of canine colonic mucosal blood flow using hydrogen gas clearance

    SciTech Connect

    Soybel, D.I.; Wan, Y.L.; Ashley, S.W.; Yan, Z.Y.; Ordway, F.S.; Cheung, L.Y.

    1987-04-01

    We have examined the feasibility of hydrogen (H/sub 2/) clearance for endoscopic measurements of colonic mucosal blood flow in anesthetized dogs. In 6 animals, measurements of H2 clearance did not differ significantly in different regions of the sigmoid colon and they were highly reproducible on different days. In a total of 12 dogs, measurements of H2 clearance correlated closely with those obtained using radioactive microspheres under resting conditions and, in 4 dogs, during infusion of vasopressin. In 8 dogs, ligation of the major arteries supplying the sigmoid colon resulted in an acute 60% decrease in sigmoid mucosal blood flow; however, in 5 animals that survived the procedure, mucosal blood flow returned nearly to control levels as early as 3 days after operation. Endoscopic H/sub 2/ clearance thus appears to be feasible for measuring mucosal blood flow in the colon. Serial measurements of H/sub 2/ clearance may prove useful in characterizing the role of mucosal blood flow in the pathogenesis of various forms of human colonic disease.

  15. Gastric mucosal blood flow during pentagastrin- and histamine-stimulated acid secretion in the rat

    PubMed Central

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

    1973-01-01

    1. Gastric mucosal blood flow was studied in the rat by means of a [14C]-aniline clearance technique. 2. There was a significant correlation between clearance and stimulated acid secretion. 3. No significant difference was found in the relationship between clearance and acid secretion during submaximal stimulation with either pentagastrin or histamine. 4. Estimates of mucosal blood flow per unit acid secretion by [14C]-aniline clearance in the rat were similar to those reported with aminopyrine clearance in the dog and cat. PMID:4777713

  16. 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. PMID:26899317

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

    PubMed

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

    2016-02-01

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

  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. [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. PMID:23469557

  1. Strong mucosal immune responses in SIV infected macaques contribute to viral control and preserved CD4+ T-cell levels in blood and mucosal tissues

    PubMed Central

    2011-01-01

    Background Since there is still no protective HIV vaccine available, better insights into immune mechanism of persons effectively controlling HIV replication in the absence of any therapy should contribute to improve further vaccine designs. However, little is known about the mucosal immune response of this small unique group of patients. Using the SIV-macaque-model for AIDS, we had the rare opportunity to analyze 14 SIV-infected rhesus macaques durably controlling viral replication (controllers). We investigated the virological and immunological profile of blood and three different mucosal tissues and compared their data to those of uninfected and animals progressing to AIDS-like disease (progressors). Results Lymphocytes from blood, bronchoalveolar lavage (BAL), and duodenal and colonic biopsies were phenotypically characterized by polychromatic flow cytometry. In controllers, we observed higher levels of CD4+, CD4+CCR5+ and Gag-specific CD8+ T-cells as well as lower immune activation in blood and all mucosal sites compared to progressors. However, we could also demonstrate that immunological changes are distinct between these three mucosal sites. Intracellular cytokine staining demonstrated a significantly higher systemic and mucosal CD8+ Gag-specific cellular immune response in controllers than in progressors. Most remarkable was the polyfunctional cytokine profile of CD8+ lymphocytes in BAL of controllers, which significantly dominated over their blood response. The overall suppression of viral replication in the controllers was confirmed by almost no detectable viral RNA in blood and all mucosal tissues investigated. Conclusion A strong and complex virus-specific CD8+ T-cell response in blood and especially in mucosal tissue of SIV-infected macaques was associated with low immune activation and an efficient suppression of viral replication. This likely afforded a repopulation of CD4+ T-cells in different mucosal compartments to almost normal levels. We

  2. Markedly Decreased Blood Perfusion of Pancreatic Islets Transplanted Intraportally Into the Liver

    PubMed Central

    Henriksnäs, Johanna; Lau, Joey; Zang, Guangxiang; Berggren, Per-Olof; Köhler, Martin; Carlsson, Per-Ola

    2012-01-01

    Experimental studies indicate low revascularization of intraportally transplanted islets. This study aimed to quantify, for the first time, the blood perfusion of intrahepatically transplanted islets and elucidate necessary factors for proper islet graft revascularization at this site. Yellow chameleon protein 3.0 islets expressing fluorescent protein in all cells were transplanted. Graft blood perfusion was determined by microspheres. The vascular density and relative contribution of donor blood vessels in revascularization was evaluated using islets expressing green fluorescent protein under the Tie-2 promoter. Blood perfusion of intrahepatic islets was as a mean only 5% of that of native islets at 1-month posttransplantation. However, there was a marked heterogeneity where blood perfusion was less decreased in islets transplanted without prior culture and in many cases restored in islets with disrupted integrity. Analysis of vascular density showed that distorted islets were well revascularized, whereas islets still intact at 1-month posttransplantation were almost avascular. Few donor endothelial cells were observed in the new islet vasculature. The very low blood perfusion of intraportally transplanted islets is likely to predispose for ischemia and hamper islet function. Since donor endothelial cells do not expand posttransplantation, disruption of islet integrity is necessary for revascularization to occur by recipient blood vessels. PMID:22315321

  3. 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 5minutes, 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 30minutes. 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. PMID:26809237

  4. SPECT Myocardial Blood Flow Quantitation Concludes Equivocal Myocardial Perfusion SPECT Studies to Increase Diagnostic Benefits.

    PubMed

    Chen, Lung-Ching; Lin, Chih-Yuan; Chen, Ing-Jou; Ku, Chi-Tai; Chen, Yen-Kung; Hsu, Bailing

    2016-01-01

    Recently, myocardial blood flow quantitation with dynamic SPECT/CT has been reported to enhance the detection of coronary artery disease in human. This advance has created important clinical applications to coronary artery disease diagnosis and management for areas where myocardial perfusion PET tracers are not available. We present 2 clinical cases that undergone a combined test of 1-day rest/dipyridamole-stress dynamic SPECT and ECG-gated myocardial perfusion SPECT scans using an integrated imaging protocol and demonstrate that flow parameters are capable to conclude equivocal myocardial perfusion SPECT studies, therefore increasing diagnostic benefits to add value in making clinical decisions. PMID:26053731

  5. 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. PMID:8727573

  6. A low-cost, small volume circuit for autologous blood normothermic perfusion of rabbit organs.

    PubMed

    Worner, Murray; Poore, Samuel; Tilkorn, Daniel; Lokmic, Zerina; Penington, Anthony J

    2014-04-01

    We have designed a laboratory extracorporeal normothermic blood perfusion system for whole organs (e.g., kidney) that achieves pulsatile flow, low levels of hemolysis, and a blood priming volume of 60 mL or less. Using this uniquely designed extracorporeal circuit, we have achieved perfusion of two isolated ex vivo constructs. In the first experiment, we successfully perfused a rabbit epigastric flap based on the femoral vessels. In the second experiment, we were able to perfuse the isolated rabbit kidney for 48 h (range for all kidneys was 12-48 h) with excellent urine output, normal arterial blood gasses at 24 h, and normal ex vivo kidney histology at the conclusion of the experiments. These parameters have not been achieved before with any known or previously published laboratory extracorporeal circuits. The study has implications for prolonged organ perfusion prior to transplantation and for tissue engineering of vascularized tissues, such as by the perfusion of decellularized organs. PMID:23981068

  7. 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. PMID:24788075

  8. 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

  9. The Effects of Scraping Therapy on Local Temperature and Blood Perfusion Volume in Healthy Subjects

    PubMed Central

    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. PMID:22666292

  10. 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

  11. Ocular perfusion pressure and ocular blood flow in glaucoma.

    PubMed

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

    2013-02-01

    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

  12. Bridging mucosal vessels associated with rhythmically oscillating blood flow in murine colitis.

    PubMed

    Turhan, Aslihan; Konerding, Moritz A; Tsuda, Akira; Ravnic, Dino J; Hanidziar, Dusan; Lin, Miao; Mentzer, Steven J

    2008-01-01

    Oscillatory blood flow in the microcirculation is generally considered to be the result of cardiopulmonary influences or active vasomotion. In this report, we describe rhythmically oscillating blood flow in the bridging vessels of the mouse colon that appeared to be independent of known biological control mechanisms. Corrosion casting and scanning electron microscopy of the mouse colon demonstrated highly branched bridging vessels that connected the submucosal vessels with the mucosal plexus. Because of similar morphometric characteristics (19 +/- 11 microm vs. 28 +/- 16 microm), bridging arterioles and venules were distinguished by tracking fluorescent nanoparticles through the microcirculation using intravital fluorescence videomicroscopy. In control mice, the blood flow through the bridging vessels was typically continuous and unidirectional. In contrast, two models of chemically induced inflammation (trinitrobenzenesulfonic acid and dextran sodium sulfate) were associated with a twofold reduction in flow velocity and the prominence of rhythmically oscillating blood flow. The blood oscillation was characterized by tracking the bidirectional displacement of fluorescent nanoparticles. Space-time plots and particle tracking of the oscillating segments demonstrated an oscillation frequency between 0.2 and 5.1 cycles per second. Discrete Fourier transforms demonstrated a power spectrum composed of several base frequencies. These observations suggest that inflammation-inducible changes in blood flow patterns in the murine colon resulted in both reduced blood flow velocity and rhythmic oscillations within the bridging vessels of the mouse colon. PMID:18085623

  13. 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

  14. Effects of vascular elastosis on uterine blood flow and perfusion in anesthetized mares.

    PubMed

    Esteller-Vico, A; Liu, I K M; Vaughan, B; Steffey, E P; Brosnan, R J

    2015-04-01

    In the uterus of the mare, data obtained using transrectal Doppler ultrasonography indicate that uterine blood flow (UBF) is dynamic and changes throughout the estrous cycle. Degenerative lesions in the uterus are associated with subfertility and infertility. Among these lesions, vascular elastosis has been reported in aged, multiparous, and infertile mares. Angiosis of the uterine vasculature could potentially compromise UBF. The objectives of this experiment are to determine levels of UBF and perfusion of reproductively healthy mares and compare them to levels of subfertile/infertile mares affected by uterine vascular elastosis. Twenty mares were classified on the basis of degree of vascular degeneration and stage of cycle. A fluorescent microsphere technique was used to measure reproductive organ perfusion, where microspheres were injected into the left ventricle of the heart and became trapped in capillary beds in proportion to blood flow and tissue perfusion. The reproductive tract was removed, sectioned, and the fluorescent intensity evaluated to measure blood flow and perfusion. Additionally, full-thickness samples of the uterine wall were examined postmortem to further assess the degree of vascular degeneration in all layers of uterine wall. The mean value of uterine perfusion for the control mares during estrus (n = 5) was higher (P < 0.01) than that during diestrus (n = 5); 17.6 and 11.9 mL/min/100g, respectively. For the subfertile/infertile mares, the mean value of tissue perfusion was not different (P > 0.05) during estrus (n = 5) and diestrus (n = 5); 5.9 and 7.2 mL/min/100g, respectively. Uterine perfusion in subfertile/infertile mares affected by elastosis was lower than that of control mares during both estrus (P < 0.01) and diestrus (P < 0.01). The differences in baseline levels of perfusion between the control and elastosis groups indicate that elastosis of the uterine vasculature is associated with decreased uterine perfusion

  15. Use of autologous blood as part of the perfusate for cardiopulmonary bypass: a priming technique.

    PubMed

    Myers, G J; Legare, J F; Sullivan, J A; Leadon, R B; Johnstone, R; Swyer, W; Squires, C; Power, C; Hirsch, G M

    2002-05-01

    In an attempt to replace the oncotic and protein coating capabilities of serum albumin in the perfusate, we established a priming protocol that used autologous blood as part of the perfusate solution. Prior to March 1, 1999, our standard priming protocol was 1650 ml of crystalloid with 250 ml of 5% serum albumin and 5,000 units of heparin. After removing albumin from our prime, our standard protocol was altered to include 40 ml of the patient's autologous blood in 1,800 ml of crystalloid and 10,000 units of heparin. To determine the intraoperative effects of using albumin/crystalloid primes (Group A), autologous blood/crystalloid primes (Group B) and crystalloid primes (Group C), a total of 178 patients were sequentially evaluated. Intraoperative parameters evaluated were total protein (TP), colloid osmotic pressure (COP), platelets (Plts) and fluid requirements during cardiopulmonary bypass (CPB). During an overlapping 12-month period of time, 1,092 consecutive cardiac surgical cases using CPB (584 albumin prime; 508 autologous blood prime) were evaluated for clinical outcomes in terms of mortality and length of hospitalization. In addition, over a period of 15 months, 1,458 patients in both the autologous blood/crystalloid group and the crystalloid only group were evaluated for the incidence of high-pressure excursions (HPE) after going on bypass. Comparative reviews of TP, COP and Plts demonstrated no significant difference 10 min after the start of bypass between Groups A and B. However, in Group C, there was a statistically significant increase in the intraoperative fluid requirements during CPB, compared to both of the other groups. There was no significant difference in the incidence of HPE, with an occurrence of 1.04% in the crystalloid only group and 1.11% in the autologous blood/crystalloid group. Autologous blood perfusates were identical to albumin perfusates in their platelet protection and reduction of fluid shifts during the intraoperative period

  16. 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.

  17. Treatment of blood flow abnormality using mucosal delivery of nitric oxide.

    PubMed

    Lee, Chi H

    2011-06-01

    This review focuses on clinical application of intravaginal formulations containing nitric oxide (NO). Poly(D,L-lactic acid-co-glycolic acid)-based microparticles or nanoparticles encapsulated with nitric oxide prodrugs, such as diethylenetriamine diazeniumdiolate and S-nitrosoglutathione, have been developed for the treatment of blood flow abnormality in various diseases including diabetes. Advanced nanotechnology allows for production of novel formulations with the capability of long-term protection, preserving the integrity of the NO donors, and delivering NO in a controlled and sustained release manner at the mucosal sites. The gene expressions of MAPK and PKC in the vaginal mucosa upon exposure to microparticles were evaluated for the mechanistic study involved with blood flow changes. The blood flow changes and protein expression of the vaginal mucosa upon exposure to intravaginal formulations containing NO donors supported that NO therapy would be suitable for the treatment of blood flow abnormality. This review subsequently would help to establish a scientific foundation for clinical trials of intravaginal NO delivery systems in humans. PMID:25788240

  18. 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.

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

    PubMed Central

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

    2011-01-01

    AIM: 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. METHODS: 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. RESULTS: 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). CONCLUSION: The intestinal mucosal permeability is increased obviously in TBI rats. Decrease of intestinal motility and IMBF occur early in TBI

  20. Optic Nerve Head Blood Flow Response to Reduced Ocular Perfusion Pressure by alteration of either the Blood Pressure or Intraocular Pressure

    PubMed Central

    Wang, Lin; Cull, Grant A; Fortune, Brad

    2015-01-01

    Purpose To test the hypothesis that blood flow autoregulation in the optic nerve head has less reserve to maintain normal blood flow in the face of blood pressure-induced ocular perfusion pressure decrease than a similar magnitude intraocular pressure-induced ocular perfusion pressure decrease. Materials and Methods Twelve normal nonhuman primates were anesthetized by continuous intravenous infusion of pentobarbital. Optic nerve blood flow was monitored by laser speckle flowgraphy. In the first group of animals (n=6), the experimental eye intraocular pressure was maintained at 10 mmHg using a saline reservoir connected to the anterior chamber. The blood pressure was gradually reduced by a slow injection of pentobarbital. In the second group (n=6), the intraocular pressure was slowly increased from 10 mmHg to 50 mmHg by raising the reservoir. In both experimental groups, optic nerve head blood flow was measured continuously. The blood pressure and intraocular pressure were simultaneously recorded in all experiments. Results The optic nerve head blood flow showed significant difference between the two groups (P = 0.021, repeat measures analysis of variance). It declined significantly more in the blood pressure group compared to the intraocular pressure group when the ocular perfusion pressure was reduced to 35 mmHg (P<0.045) and below. There was also a significant interaction between blood flow changes and the ocular perfusion pressure treatment (P=0.004, adjusted Greenhouse & Geisser univariate test), indicating the gradually enlarged blood flow difference between the two groups was due to the ocular perfusion pressure decrease. Conclusions The results show that optic nerve head blood flow is more susceptible to an ocular perfusion pressure decrease induced by lowering the blood pressure compared with that induced by increasing the intraocular pressure. This blood flow autoregulation capacity vulnerability to low blood pressure may provide experimental evidence

  1. 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.

  2. Anastomotic leakage in rectal cancer surgery: The role of blood perfusion

    PubMed Central

    Rutegård, Martin; Rutegård, Jörgen

    2015-01-01

    Anastomotic leakage after anterior resection for rectal cancer remains a common and often devastating complication. Preoperative risk factors for anastomotic leakage have been studied extensively and are used for patient selection, especially whether to perform a diverting stoma or not. From the current literature, data suggest that perfusion in the rectal stump rather than in the colonic limb may be more important for the integrity of the colorectal anastomosis. Moreover, available research suggests that the mid and upper rectum is considerably more vascularized than the lower part, in which the posterior compartment seems most vulnerable. These data fit neatly with the observation that anastomotic leaks are far more frequent in patients undergoing total compared to partial mesorectal excision, and also that most leaks occur dorsally. Clinical judgment has been shown to ineffectively assess anastomotic viability, while promising methods to measure blood perfusion are evolving. Much interest has recently been turned to near-infrared light technology, enhanced with fluorescent agents, which enables intraoperative perfusion assessment. Preliminary data are promising, but large-scale controlled trials are lacking. With maturation of such technology, perfusion measurements may in the future inform the surgeon whether anastomoses are at risk. In high colorectal anastomoses, anastomotic revision might be feasible, while a diverting stoma could be fashioned selectively instead of routinely for low anastomoses. PMID:26649151

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

    NASA Astrophysics Data System (ADS)

    Baba, J. S.; Akl, T. J.; Coté, G. L.; Wilson, M. A.; Ericson, M. N.

    2011-03-01

    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.

  4. 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)

  5. 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.

  6. Assessment of myocardial blood perfusion improved by CD151 in a pig myocardial infarction model

    PubMed Central

    Zuo, Hou-juan; Liu, Zheng-xiang; Liu, Xiao-chun; Yang, Jun; Liu, Tao; Wen, Sha; Wang, Dao-wen; Zhang, Xin

    2009-01-01

    Aim: To appraise the efficacy of CD151-induced myocardial therapeutic angiogenesis in a pig myocardial infarction model. Methods: CD151 and anti-CD151 were constructed into the recombinant adeno-associated virus (rAAV) vector. All 26 pigs were subjected to coronary artery ligation or no surgery. Eight weeks after coronary artery ligation, the expression of CD151 was measured by Western blot and immunostaining. Capillary density was evaluated using immunostaining for von Willebrand factor (vWF). 13N-labeled NH3 positron emission computed tomography ([13N]NH3 PET) was measured to assess regional myocardial perfusion and the defect area. Results: CD151 gene delivery could increase the expression of CD151 at protein level. Over-expression of CD151 increased the density of total capillaries in the ischemic myocardium, significantly improved the blood perfusion and reduced the defect area percentage. Conclusion: This study demonstrated that the rAAV-mediated CD151 gene delivery promoted efficient neovascularization and increased the blood perfusion after myocardial infarction in pigs. PMID:19079294

  7. Modulation of Perfusion and Oxygenation by Red Blood Cell Oxygen Affinity during Acute Anemia

    PubMed Central

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

    2008-01-01

    Responses to exchange transfusion using red blood cells (RBCs) with modified hemoglobin (Hb) oxygen (O2) 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-O2 affinity. In vitro P50s (partial pressure of O2 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 Po2 levels were measured. RBcs with P50 of 45 mm Hg increased tissue Po2 and decreased O2 delivery (Do2) and extraction (Vo2) and RBCs with P50 of 60 mmHg reduced FCD, microvascular flow, tissue Po2, Do2 and Vo2. Erythrocytes with increased Hb-O2 affinity maintained hemodynamic conditions, Do2 and decreased tissue Po2. This study shows that in an anemic condition, maximal tissue Po2 does not correspond to maximal Do2 and Vo2. PMID:17884988

  8. 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.

  9. 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. PMID:26632263

  10. Effect of prostaglandins on the blood-aqueous barrier of the perfused cat eye.

    PubMed

    van Alphen, G W; Wilhelm, P

    1978-01-01

    With a technique of direct visualization of the arterially perfused cat eye, the pressure head may be chosen so that fluorescein added to the perfusate just barely stains the ciliary processes. After addition of PGE1, PGE2, PGF2alpha arachidonic acid, or indomethacin, with or without PG's, no more dye emerged from the processes. The addition of acetylcholine in the eserinized eye floods the processes with dye, apparently affecting the pore size of the blood-aqueous barrier; PG's may slightly inhibit, rather than facilitate, the emergence of fluorescein from the processes. It is speculated that in the cat PG's elevate pressure and protein content by backflow from the circle of Hovius, which is the equivalent of Schlemm's canal. PMID:621127

  11. Differential regulation of human T cell responsiveness by mucosal versus blood monocytes.

    PubMed

    Qiao, L; Braunstein, J; Golling, M; Schürmann, G; Autschbach, F; Möller, P; Meuer, S

    1996-04-01

    Human intestinal T lymphocytes are constantly exposed to a large number of foreign antigens without developing a systemic immune response. One crucial mechanisms leading to this intestinal hyporesponsiveness is based on impaired signal transduction through the T cell receptor/CD3 complex in lamina propria T lymphocytes (LP-T). In this study, we addressed the question whether a lack of co-stimulatory/progression signals might also contribute to LP-T hyporesponsiveness. To this end, isolated human monocyte populations from the intestinal lamina propria were obtained and their phenotypes as well as their capacity to promote T cell activation studied. Here, we demonstrate that lamina propria macrophages (LP-MO), in contrast to peripheral blood monocytes (PB-MO), do not support proliferation of either LP-T or PB-T. This may be due to the low expression of ligands (CD54, CD58, CD80) for the T cell accessory receptors CD11/18, CD2 and CD28/CTLA-4 on mucosal macrophages. Thus, down-regulation of both recognition/competence and co-stimulatory/progression signals contribute to intestinal hypo- or unresponsiveness. PMID:8625989

  12. 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.

  13. Effect of spinal cord compression on local vascular blood flow and perfusion capacity.

    PubMed

    Alshareef, Mohammed; Krishna, Vibhor; Ferdous, Jahid; Alshareef, Ahmed; Kindy, Mark; Kolachalama, Vijaya B; Shazly, Tarek

    2014-01-01

    Spinal cord injury (SCI) can induce prolonged spinal cord compression that may result in a reduction of local tissue perfusion, progressive ischemia, and potentially irreversible tissue necrosis. Due to the combination of risk factors and the varied presentation of symptoms, the appropriate method and time course for clinical intervention following SCI are not always evident. In this study, a three-dimensional finite element fluid-structure interaction model of the cervical spinal cord was developed to examine how traditionally sub-clinical compressive mechanical loads impact spinal arterial blood flow. The spinal cord and surrounding dura mater were modeled as linear elastic, isotropic, and incompressible solids, while blood was modeled as a single-phased, incompressible Newtonian fluid. Simulation results indicate that anterior, posterior, and anteroposterior compressions of the cervical spinal cord have significantly different ischemic potentials, with prediction that the posterior component of loading elevates patient risk due to the concomitant reduction of blood flow in the arterial branches. Conversely, anterior loading compromises flow through the anterior spinal artery but minimally impacts branch flow rates. The findings of this study provide novel insight into how sub-clinical spinal cord compression could give rise to certain disease states, and suggest a need to monitor spinal artery perfusion following even mild compressive loading. PMID:25268384

  14. Effect of Spinal Cord Compression on Local Vascular Blood Flow and Perfusion Capacity

    PubMed Central

    Alshareef, Mohammed; Krishna, Vibhor; Ferdous, Jahid; Alshareef, Ahmed; Kindy, Mark; Kolachalama, Vijaya B.; Shazly, Tarek

    2014-01-01

    Spinal cord injury (SCI) can induce prolonged spinal cord compression that may result in a reduction of local tissue perfusion, progressive ischemia, and potentially irreversible tissue necrosis. Due to the combination of risk factors and the varied presentation of symptoms, the appropriate method and time course for clinical intervention following SCI are not always evident. In this study, a three-dimensional finite element fluid-structure interaction model of the cervical spinal cord was developed to examine how traditionally sub-clinical compressive mechanical loads impact spinal arterial blood flow. The spinal cord and surrounding dura mater were modeled as linear elastic, isotropic, and incompressible solids, while blood was modeled as a single-phased, incompressible Newtonian fluid. Simulation results indicate that anterior, posterior, and anteroposterior compressions of the cervical spinal cord have significantly different ischemic potentials, with prediction that the posterior component of loading elevates patient risk due to the concomitant reduction of blood flow in the arterial branches. Conversely, anterior loading compromises flow through the anterior spinal artery but minimally impacts branch flow rates. The findings of this study provide novel insight into how sub-clinical spinal cord compression could give rise to certain disease states, and suggest a need to monitor spinal artery perfusion following even mild compressive loading. PMID:25268384

  15. Contrast-enhanced ultrasonography to assess blood perfusion of skeletal muscles in normal dogs.

    PubMed

    Oh, Juyeon; Jeon, Sunghoon; Choi, Jihye

    2015-07-01

    This study evaluated perfusion of skeletal muscle using contrast enhanced ultrasonography in humerus, radius, femur and tibia in normal dogs. Contrast enhanced ultrasonography for each region was performed after injecting 0.5 mL and 1 mL of contrast medium (SonoVue) in every dog. Blood perfusion was assessed quantitatively by measuring the peak intensity, time to the peak intensity and area under the curve from the time-intensity curve. Vascularization in skeletal muscle was qualitatively graded with a score of 0-3 according to the number of vascular signals. A parabolic shape of time-intensity curve was observed from muscles in normal dogs, and time to the peak intensity, the peak intensity and area under the curve of each muscle were not significantly different according to the appendicular regions examined and the dosage of contrast agent administered. This study reports that feasibility of contrast enhanced ultrasonography for assessment of the muscular perfusion in canine appendicular regions. PMID:25754794

  16. Contrast-enhanced ultrasonography to assess blood perfusion of skeletal muscles in normal dogs

    PubMed Central

    OH, Juyeon; JEON, Sunghoon; CHOI, Jihye

    2015-01-01

    This study evaluated perfusion of skeletal muscle using contrast enhanced ultrasonography in humerus, radius, femur and tibia in normal dogs. Contrast enhanced ultrasonography for each region was performed after injecting 0.5 mL and 1 mL of contrast medium (SonoVue) in every dog. Blood perfusion was assessed quantitatively by measuring the peak intensity, time to the peak intensity and area under the curve from the time–intensity curve. Vascularization in skeletal muscle was qualitatively graded with a score of 0–3 according to the number of vascular signals. A parabolic shape of time–intensity curve was observed from muscles in normal dogs, and time to the peak intensity, the peak intensity and area under the curve of each muscle were not significantly different according to the appendicular regions examined and the dosage of contrast agent administered. This study reports that feasibility of contrast enhanced ultrasonography for assessment of the muscular perfusion in canine appendicular regions. PMID:25754794

  17. Blood flow redistribution and ventilation-perfusion mismatch during embolic pulmonary arterial occlusion

    PubMed Central

    Burrowes, K. S.; Clark, A. R.; Tawhai, M. H.

    2011-01-01

    Acute pulmonary embolism causes redistribution of blood in the lung, which impairs ventilation/perfusion matching and gas exchange and can elevate pulmonary arterial pressure (PAP) by increasing pulmonary vascular resistance (PVR). An anatomically-based multi-scale model of the human pulmonary circulation was used to simulate pre- and post-occlusion flow, to study blood flow redistribution in the presence of an embolus, and to evaluate whether reduction in perfused vascular bed is sufficient to increase PAP to hypertensive levels, or whether other vasoconstrictive mechanisms are necessary. A model of oxygen transfer from air to blood was included to assess the impact of vascular occlusion on oxygen exchange. Emboli of 5, 7, and 10 mm radius were introduced to occlude increasing proportions of the vasculature. Blood flow redistribution was calculated after arterial occlusion, giving predictions of PAP, PVR, flow redistribution, and micro-circulatory flow dynamics. Because of the large flow reserve capacity (via both capillary recruitment and distension), approximately 55% of the vasculature was occluded before PAP reached clinically significant levels indicative of hypertension. In contrast, model predictions showed that even relatively low levels of occlusion could cause localized oxygen deficit. Flow preferentially redistributed to gravitationally non-dependent regions regardless of occlusion location, due to the greater potential for capillary recruitment in this region. Red blood cell transit times decreased below the minimum time for oxygen saturation (<0.25 s) and capillary pressures became high enough to initiate cell damage (which may result in edema) only after ~80% of the lung was occluded. PMID:22140626

  18. Differential Blood and Mucosal Immune Responses against an HIV-1 Vaccine Administered via Inguinal or Deltoid Injection

    PubMed Central

    Price, Charles; Hultin, Lance E.; Elliott, Julie; Hultin, Patricia M.; Shih, Roger; Hausner, Mary Ann; Ng, Hwee L.; Hoffman, Jennifer; Jamieson, Beth D.

    2014-01-01

    Mucosal immunity is central to sexual transmission and overall pathogenesis of HIV-1 infection, but the ability of vaccines to induce immune responses in mucosal tissue compartments is poorly defined. Because macaque vaccine studies suggest that inguinal (versus limb) vaccination may better target sexually-exposed mucosa, we performed a randomized, double-blinded, placebo-controlled Phase I trial in HIV-1-uninfected volunteers, using the recombinant Canarypox (CP) vaccine vCP205 delivered by different routes. 12 persons received vaccine and 6 received placebo, divided evenly between deltoid-intramuscular (deltoid-IM) or inguinal-subcutaneous (inguinal-SC) injection routes. The most significant safety events were injection site reactions (Grade 3) in one inguinal vaccinee. CP-specific antibodies were detected in the blood of all 12 vaccinees by Day 24, while HIV-1-specific antibodies were observed in the blood and gut mucosa of 1/9 and 4/9 evaluated vaccinees respectively, with gut antibodies appearing earlier in inguinal vaccinees (24–180 versus 180–365 days). HIV-1-specific CD8+ T lymphocytes (CTLs) were observed in 7/12 vaccinees, and blood and gut targeting were distinct. Within blood, both deltoid and inguinal responders had detectable CTL responses by 17–24 days; inguinal responders had early responses (within 10 days) while deltoid responders had later responses (24–180 days) in gut mucosa. Our results demonstrate relative safety of inguinal vaccination and qualitative or quantitative compartmentalization of immune responses between blood and gut mucosa, and highlight the importance of not only evaluating early blood responses to HIV-1 vaccines but also mucosal responses over time. Trial Registration ClinicalTrials.gov NCT00076817 PMID:24558403

  19. 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

  20. 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.

  1. The functional state of the isolated rabbit kidney perfused with autologous blood.

    PubMed

    Cuypers, Y; Vandenreyt, I; Bipat, R; Toelsie, J; Van Damme, B; Steels, P

    2000-08-01

    This report describes the technique and procedure for perfusing an isolated rabbit kidney with 25 ml heparinized autologous blood in a closed circuit including a pump and an oxygenator. The duration of the operative ischaemia was 5-8 min; the perfusion lasted 2.5 hours. An additional infusion was made to compensate for urinary losses. Renal blood flow increased progressively from 2.01+/-0.1 to 2.65+/-0.22* ml/g kidney weight (kw) per min (*P<0.05). Between the first (P1) and the last (P4) urine collection period the glomerular filtration rate (GFR) fell from 288+/-25 to 217+/-38* microl/g kw per min, urine flow from 5.58+/-1.13 to 4.91+/-0.75 microl/g kw per min, Na+ excretion from 1.07+/-0.19 to 0.63+/-0.12* micromol/g kw per min, K+ excretion from 0.46+/-0.03 to 0.28+/-0.05* micromol/g kw per min, P excretion from 2.5+/-0.2 to 2.0+/-0.5 microg/g kw per min, Ca excretion from 0.4+/-0.1 to 0.12+/-0.05* microg/g kw per min, creatinine excretion from 6.94+/-0.32 to 5.68+/-0.54 microg/g kw per min, glucose excretion from 18.2+/-3.2 to 1.6+/-0.5* microg/g kw per min, the free water clearance (CH2O) from -6.57+/-0.85 to -5.10+/-1.31 microl/g kw per min and urine osmolality from 600+/-52 to 590+/-105 mOsm/kg, urea excretion from 0.75+/-0.16 to 0.95+/-0.13 micromol/g kw per min. Excretion of glucose, P or Ca was observed only above a given plasma threshold value, and no transport maximum was found for glucose or P. Ca reabsorption paralleled the Na reabsorption. The proximal tubule pressure, measured within the 1st h of perfusion, was 12.5+/-1.1 mm Hg. Histological examination at the end of the perfusion showed dilatation of the tubules as in the non-perfused kidneys, and the presence of numerous bacteria. Hypertonic urine (380-1110 mOsm/kg) was observed in the presence of vasopressin, in the latter's absence the urine was hypotonic urine (206-278 mOsm/kg). There was no correlation between renal plasma flow and the GFR. CH2O increased with increasing filtered Na+ load. In

  2. Brief ex vivo perfusion with heparinized and/or citrated whole blood enhances tolerance of free muscle flaps to prolonged ischemia.

    PubMed

    Fowler, J D; Li, X; Cooley, B C

    1999-01-01

    This study investigated the use of heparinized and/or citrated whole blood as a perfusate for enhancing muscle tolerance to warm ischemia. Unilateral cutaneous trunci muscle flaps were harvested from Sprague-Dawley rats and stored for 10 hr at 22-24 degrees C prior to transplantation to the groin. One group served as a non-perfused control. In three experimental groups, the flaps were hand-perfused ex vivo with 1.0 ml of heparinized, citrated, or heparinized and citrated autogenous whole blood at physiological pressures. Perfusion was administered over a 10-min period 5 hr into the ischemic period. Flaps were revascularized on the femoral vessels and then harvested 48 hr following revascularization. Tissue injury was assessed by calculation of flap weight change (indicator of tissue edema), histochemical evaluation of muscle dehydrogenase activity (nitroblue tetrazolium assay), and light microscopy. All perfused groups had significantly higher muscle dehydrogenase activity compared with non-perfused controls (P < 0.005). Perfusion with combined heparin-citrated blood was significantly more protective than perfusion with either anticoagulant alone (P < 0.025). The only statistically significant reduction in percent flap edema was seen in the combined heparin-citrate perfusion of flaps compared with nonperfused controls (P < 0.05). Histologic evaluation confirmed a reduction in tissue edema in the perfused flaps. We conclude that mid-ischemic perfusion with heparinized and/or citrated blood limits the deleterious effects of extended warm ischemia. PMID:10231122

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

    PubMed

    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

  4. 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

  5. Absolute quantification of cerebral blood flow in neurologically normal volunteers: dynamic-susceptibility contrast MRI-perfusion compared with computed tomography (CT)-perfusion.

    PubMed

    Ziegelitz, Doerthe; Starck, Göran; Mikkelsen, Irene K; Tullberg, Mats; Edsbagge, Mikael; Wikkelsö, Carsten; Forssell-Aronson, Eva; Holtås, Stig; Knutsson, Linda

    2009-07-01

    To improve the reproducibility of arterial input function (AIF) registration and absolute cerebral blood flow (CBF) quantification in dynamic-susceptibility MRI-perfusion (MRP) at 1.5T, we rescaled the AIF by use of a venous output function (VOF). We compared CBF estimates of 20 healthy, elderly volunteers, obtained by computed tomography (CT)-perfusion (CTP) and MRP on two consecutive days. MRP, calculated without the AIF correction, did not result in any significant correlation with CTP. The rescaled MRP showed fair to moderate correlation with CTP for the central gray matter (GM) and the whole brain. Our results indicate that the method used for correction of partial volume effects (PVEs) improves MRP experiments by reducing AIF-introduced variance at 1.5T. PMID:19253361

  6. Three-dimensional analysis for radio-frequency ablation of liver tumor with blood perfusion effect.

    PubMed

    Sheu, Tony W H; Chou, C W; Tsai, S F; Liang, P C

    2005-08-01

    Increase of temperature above 50 approximately 60 degrees C for few minutes by the emitted radio-frequency (RF) energy has been shown to be able to denaturate the intracellular proteins and destruct membranes of tumor cells. To improve the efficacy of this thermal therapy, it is important to investigate factors that may affect the RF heating characteristics for the hepatocellular carcinoma and metastatic liver tumors. In order to make sure the applied RF energy is adequate to ablate the target tumor, a 3D thermoelectric analysis for the system consisting of liver, liver arteries and 4 mm diameter tumor is conducted. The effect of blood perfusion is addressed in this study. PMID:16298845

  7. 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. PMID:24125196

  8. Protective effects of Ankaferd blood stopper on aspirin-induced oxidative mucosal damage in a rat model of gastric injury.

    PubMed

    Hasgul, Rukiye; Uysal, Sema; Haltas, Hacer; Akyol, Sumeyye; Yuksel, Yasemin; Gurel, Ayse; Armutcu, Ferah

    2014-11-01

    The exposure of gastric mucosa to damaging factors, such as ethanol and some therapeutic drugs, produces pathological changes: inflammatory process, hemorrhagic erosions and even acute ulcers. Ankaferd blood stopper (ABS) comprises a standardized mixture of five different plant extracts. The purpose of our present investigations is to explain the participation of reactive oxygen species in acute gastric mucosal damage by acetylsalicylic acid (ASA) and the effects of new hemostatic agent ABS. Experiments were carried out on 23 male Wistar rats. To assess gastric mucosal damage, biochemical and histopathological data were used. The colorimetric assays were used to determine the malondialdehyde (MDA) and superoxide dismutase (SOD) activity. The level of myeloperoxidase (MPO) activity, the level of nitric oxide (NO) and the proinflammatory cytokine tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent assay technique. We demonstrated that the biological effects of ROS were estimated by measuring the tissue and plasma levels of MDA, the products of lipid peroxidation, as well as the activity of SOD and the scavenger of ROS produced by ASA in the experiment group. Moreover, it was found that MPO activity as well as NO and TNF-α levels also demonstrated significant improvement by ABS treatment. The pathogenesis of experimental ASA-induced mucosal damage in rat stomach includes the generation of ROS that seems to play an important role, due to the generation of lipid peroxides, accompanied by the impairment of antioxidative enzyme activity of cells. ABS appeared to attenuate the oxidative and inflammatory changes caused by ASA-induced gastric mucosal damage in rats. PMID:23114375

  9. The effect of prolonged perfusion with a membrane oxygenator (PPMO) on white blood cells.

    PubMed

    Bergman, P; Belboul, A; Friberg, L G; al-Khaja, N; Mellgren, G; Roberts, D

    1994-01-01

    Preserving the rheological properties of whole blood cells is vital for their smooth passage in the capillaries without causing blockage and disturbances in the microcirculation. To evaluate the effect of mechanical trauma on the rheology of white blood cells during prolonged perfusion with membrane oxygenation (PPMO), 16 in vitro experiments were conducted for 72 hours. The St George Carrimed Filtrometer was used to estimate the plasma white cell filtration rates (P-WFR). Also an in vitro estimation of the ability of individual cells to pass through capillaries, the white blood cell clogging rate (WBC-CR), the number of clogging particles (WBC-CP), the total white blood cell count (T-WBC) and two in vitro estimations to assess the effect of aggregates and stiff cells in blocking the microcirculation were performed. The traumatized white cells reduced their mean P-WFR by 37% +/- 9, 72% +/- 2 and 76% +/- 2 at 24, 48 and 72 hours respectively (p < 0.001). The mean WBC-CR was increased to 15.2 +/- 1.5, 32.6 +/- 2.2 and 40.3 +/- 8.3 x 10(2)%/ml at 24, 48 and 72 hours respectively (p < 0.001). The mean WBC-CP was increased to 6.6 +/- 1.5, 9.7 +/- 1.2 and 13.9 +/- 2.1 x 10(6)/ml at 24 hours (p < 0.05), 48 and 72 hours respectively (p < 0.001). The T-WBC was decreased to 55% +/- 0.3, 23% +/- 0.2 and 14% +/- 0.1 and 14% +/- 0.1 at 24, 48 and 72 hours respectively (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8161866

  10. 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. PMID:23347012

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

    PubMed Central

    Chiquet, Christophe; Godin-Ribuot, Diane; Amoos, Serge; Loeuillet, Corinne; Bernabei, Mario; Geiser, Martial

    2015-01-01

    Purpose Noninvasive techniques for ocular blood perfusion assessment are of crucial importance for exploring microvascular alterations related to systemic and ocular diseases. However, few techniques adapted to rodents are available and most are invasive or not specifically focused on the optic nerve head (ONH), choroid or retinal circulation. Here we present the results obtained with a new rodent-adapted compact fundus camera based on laser Doppler flowmetry (LDF). Methods A confocal miniature flowmeter was fixed to a specially designed 3D rotating mechanical arm and adjusted on a rodent stereotaxic table in order to accurately point the laser beam at the retinal region of interest. The linearity of the LDF measurements was assessed using a rotating Teflon wheel and a flow of microspheres in a glass capillary. In vivo reproducibility was assessed in Wistar rats with repeated measurements (inter-session and inter-day) of retinal arteries and ONH blood velocity in six and ten rats, respectively. These parameters were also recorded during an acute intraocular pressure increase to 150 mmHg and after heart arrest (n = 5 rats). Results The perfusion measurements showed perfect linearity between LDF velocity and Teflon wheel or microsphere speed. Intraclass correlation coefficients for retinal arteries and ONH velocity (0.82 and 0.86, respectively) indicated strong inter-session repeatability and stability. Inter-day reproducibility was good (0.79 and 0.7, respectively). Upon ocular blood flow cessation, the retinal artery velocity signal substantially decreased, whereas the ONH signal did not significantly vary, suggesting that it could mostly be attributed to tissue light scattering. Conclusion We have demonstrated that, while not adapted for ONH blood perfusion assessment, this device allows pertinent, stable and repeatable measurements of retinal blood perfusion in rats. PMID:26226150

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

    PubMed Central

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

    2005-01-01

    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. PMID:16306271

  13. 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

  14. CT perfusion cerebral blood volume does not always predict infarct core in acute ischemic stroke.

    PubMed

    d'Esterre, Christopher D; Roversi, Gloria; Padroni, Marina; Bernardoni, Andrea; Tamborino, Carmine; De Vito, Alessandro; Azzini, Cristiano; Marcello, Onofrio; Saletti, Andrea; Ceruti, Stefano; Lee, Ting Yim; Fainardi, Enrico

    2015-10-01

    We investigated the practical clinical utility of the CT perfusion (CTP) cerebral blood volume (CBV) parameter for differentiating salvageable from non-salvageable tissue in acute ischemic stroke (AIS). Fifty-five patients with AIS were imaged within 6 h from onset using CTP. Admission CBV defect (CBVD) volume was outlined using previously established gray and white matter CBV thresholds for infarct core. Admission cerebral blood flow (CBF) hypoperfusion and CBF/CBV mismatch were visually evaluated. Truncation of the ischemic time-density curve (ITDC) and hypervolemia status at admission, recanalization at 24-h CT angiography, hemorrhagic transformation (HT) at 24 h and/or 7-day non-contrast CT (NCCT), final infarct volume as indicated by 3-month NCCT defect (NCCTD) and 3-month modified Rankin Score were determined. Patients with recanalization and no truncation had the highest correlation (R = 0.81) and regression slope (0.80) between CBVD and NCCTD. Regression slopes were close to zero for patients with admission hypervolemia with/without recanalization. Hypervolemia underestimated (p = 0.02), while recanalization and ITDC truncation overestimated (p = 0.03) the NCCTD. Among patients with confirmed recanalization at 24 h, 38 % patients had an admission CBF/CBV mismatch within normal appearing areas on respective NCCT. 83 % of these patients developed infarction in admission hypervolemic CBF/CBV mismatch tissue. A reduction in CBV is a valuable predictor of infarct core when the acquisition of ITDC data is complete and hypervolemia is absent within the tissue destined to infarct. Raised or normal CBV is not always indicative of salvageable tissue, contrary to the current definition of penumbra. PMID:25981225

  15. 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. PMID:3171254

  16. Effects of thromboxane A2 analogue on vascular resistance distribution and permeability in isolated blood-perfused dog lungs.

    PubMed

    Shibamoto, T; Wang, H G; Yamaguchi, Y; Hayashi, T; Saeki, Y; Tanaka, S; Koyama, S

    1995-01-01

    This study was designed to determine the effects of thromboxane A2 (TxA2) on the distribution of vascular resistance, lung weight, and microvascular permeability in isolated dog lungs perfused at a constant pressure with autologous blood. The stable TxA2 analogue (STA2; 30 micrograms, n = 5) caused an increase in pulmonary capillary pressure (Pc) assessed as double-occlusion pressure to 14.0 +/- 0.4 mmHg from the baseline of 7.9 +/- 0.3 mmHg with progressive lung weight gain. Pulmonary vascular resistance increased threefold exclusively due to pulmonary venoconstriction. Pulmonary venoconstriction was confirmed in lungs perfused in a reverse direction from the pulmonary vein to the artery (n = 5), as evidenced by marked precapillary vasoconstriction and a sustained lung weight loss. Furthermore, in lungs perfused at a constant blood flow (n = 5), STA2 also caused selective pulmonary venoconstriction. Vascular permeability measured by the capillary filtration coefficient and the isogravimetric Pc at 30 and 60 min after STA2 infusion did not change significantly from baseline in any lungs studied. Moreover, elevation of Pc by raising the venous reservoir of the intact lobes (n = 5) to the same level as the STA2 lungs caused a greater or similar weight gain compared with the STA2 lungs. Thus, we conclude that TxA2 constricts selectively the pulmonary vein resulting in an increase in Pc and lung weight gain without significant changes in vascular permeability in isolated blood-perfused dog lungs. PMID:7564480

  17. Parametric investigation of heating due to magnetic fluid hyperthermia in a tumor with blood perfusion

    NASA Astrophysics Data System (ADS)

    Liangruksa, Monrudee; Ganguly, Ranjan; Puri, Ishwar K.

    2011-03-01

    Magnetic fluid hyperthermia (MFH) is a cancer treatment that can selectively elevate the tumor temperature without significantly damaging the surrounding healthy tissue. Optimal MFH design requires a fundamental parametric investigation of the heating of soft materials by magnetic fluids. We model the problem of a spherical tumor and its surrounding healthy tissue that are heated by exciting a homogeneous dispersion of magnetic nanoparticles infused only into the tumor with an external AC magnetic field. The key dimensionless parameters influencing thermotherapy are the Péclet, Fourier, and Joule numbers. Analytical solutions for transient and steady hyperthermia provide correlations between these parameters and the portions of tumor and healthy tissue that are subjected to a threshold temperature beyond which they are damaged. Increasing the ratio of the Fourier and Joule numbers also increases the tumor temperature, but doing so can damage the healthy tissue. Higher magnetic heating is required for larger Péclet numbers due to the larger convection heat loss that occurs through blood perfusion. A comparison of the model predictions with previous experimental data for MFH applied to rabbit tumors shows good agreement. The optimal MFH conditions are identified based on two indices, the fraction IT of the tumor volume in which the local temperature is above a threshold temperature and the ratio IN of the damaged normal tissue volume to the tumor tissue volume that also lies above it. The spatial variation in the nanoparticle concentration is also considered. A Gaussian distribution provides efficacy while minimizing the possibility of generating a tumor hot spot. Varying the thermal properties of tumor and normal tissue alters ITand IN but the nature of the temperature distribution remains unchanged.

  18. Paradox: increased blood perfusion to the face enhances protection against frostbite while it lowers wind chill equivalent temperatures

    NASA Astrophysics Data System (ADS)

    Shitzer, Avraham

    2007-05-01

    A model of facial heat exchange in cold and windy environments is presented. The tissue is depicted as a hollow cylinder and the model includes heat conduction and heat transport by blood circulation from the warmer core. A steady-state solution facilitating the estimation of wind chill equivalent temperature (WCET) as a function of the effective wind velocity, air temperature and blood perfusion rate was obtained. The results quantify and demonstrate the elevation of skin temperatures caused by increased flow of warmer blood from the inner core to the face. Elevated facial temperatures, while enhancing protection against frostbite and other cold-related injuries, also increase heat loss to the colder environment. Paradoxically, such elevated facial temperatures cause WCETs, as estimated by the prevailing definition, to attain lower rather than higher values, indicating, in fact, increased risk of frostbite. The results of this study should be useful in understanding and quantifying the effects of blood perfusion in protection against cold-related injuries. They should also be considered in the re-evaluation and re-formulation of the concept of wind chill, which has been a useful cold weather indicator for decades.

  19. Paradox: increased blood perfusion to the face enhances protection against frostbite while it lowers wind chill equivalent temperatures.

    PubMed

    Shitzer, Avraham

    2007-05-01

    A model of facial heat exchange in cold and windy environments is presented. The tissue is depicted as a hollow cylinder and the model includes heat conduction and heat transport by blood circulation from the warmer core. A steady-state solution facilitating the estimation of wind chill equivalent temperature (WCET) as a function of the effective wind velocity, air temperature and blood perfusion rate was obtained. The results quantify and demonstrate the elevation of skin temperatures caused by increased flow of warmer blood from the inner core to the face. Elevated facial temperatures, while enhancing protection against frostbite and other cold-related injuries, also increase heat loss to the colder environment. Paradoxically, such elevated facial temperatures cause WCETs, as estimated by the prevailing definition, to attain lower rather than higher values, indicating, in fact, increased risk of frostbite. The results of this study should be useful in understanding and quantifying the effects of blood perfusion in protection against cold-related injuries. They should also be considered in the re-evaluation and re-formulation of the concept of wind chill, which has been a useful cold weather indicator for decades. PMID:17333290

  20. Variability in platelet responses to collagen--comparison between whole blood perfusions, traditional platelet function tests and PFA-100.

    PubMed

    Lepäntalo, A; Beer, J H; Siljander, P; Syrjälä, M; Lassila, R

    2001-07-15

    The purpose of this study was to determine if the results obtained in platelet function tests and whole blood perfusions are associated with those in platelet function analyser (PFA)-100. We used collagen type I monomers and fibrils to analyse the distinct roles of glycoprotein (GP) Ia/IIa and other collagen receptors in flowing blood under a high shear rate (1600/s) and in aggregation studies. Also, anticoagulation [citrate vs. D-phenylalanyl-1-prolyl-1 arginine chloromethyl ketone (PPACK)] was varied to enhance the functions of GP Ia/IIa, since it has been shown that the cation-poor environment of citrated blood impairs GP Ia/IIa-dependent platelet recruitment. Large interindividual variability (45-fold) was detected in deposition of platelets in whole blood perfusions over collagen monomers, whereas this variation was only fourfold in fibrils. In PFA, this variation was reduced to 2.5-fold. However, platelet deposition on monomers is associated with epinephrine-enhanced PFA (r=-.49, P<.03), whereas platelet deposition on fibrils is correlated with adenosine diphosphate (ADP)-enhanced PFA (r=-.47, P<.05), suggesting a distinct synergism between epinephrine and monomers (GP Ia/IIa) as well as ADP with fibrils (other collagen receptors). Donors with 807 C/C polymorphism of GP Ia (n=14) had longer lag phase in aggregation experiments compared with C/T (n=7) both by monomers and fibrils (P<.04), but these polymorphisms with their mild impact on GP Ia/IIa activity did not markedly differ in other tests. In conclusion, the results obtained in perfusion studies and PFA experiments correlated, but PFA fails to reveal the large-scale variability related to collagen-induced platelet responses. PMID:11457470

  1. Mucosal Blood Group Antigen Expression Profiles and HIV Infections: A Study among Female Sex Workers in Kenya

    PubMed Central

    Chanzu, Nadia Musimbi; Mwanda, Walter; Oyugi, Julius; Anzala, Omu

    2015-01-01

    Background The ABO blood group antigens are carbohydrate moieties expressed on human red blood cells however; these antigens can also be expressed on some other cells particularly the surface of epithelial cells and may be found in mucosal secretions. In many human populations 80% secrete ABO antigens (termed ‘secretors’) while 20% do not (termed ‘non-secretors’). Furthermore, there are disease conditions that are associated with secretor status. Objective To investigate correlations between secretor status and HIV infection among female sex workers in Nairobi, Kenya. Methodology This cross-sectional study recruited 280 female sex workers aged 18–65 years from the Pumwani Majengo cohort, Kenya. Blood typing was determined by serological techniques using monoclonal antibodies to the ABO blood group antigens. Secretor phenotyping was determined using anti-H specific lectins specific to salivary, vaginal and cervical blood group H antigen using the agglutination inhibition technique and correlated to individual HIV sero-status. Participants were additionally screened for Bacterial vaginosis, Neisseria gonorrhoea and Trichomonas vaginalis. Results Out of the 280 participants, 212 (75.7%) were secretors and 68 (24.3%) were non-secretors. The incidence of all infections: HIV, Bacterial vaginosis, Neisseria gonorrhoea and Trichomonas vaginalis was higher among secretors compared to non-secretors. However, this difference was only statistically significant for HIV infection incidence rates: HIV infected secretors (83.7%) versus HIV un-infected secretors (71.8%) (p = 0.029) Based on ABO phenotype stratification, the incidence of HIV infection was higher among blood group A secretors (26/52 = 50%), in comparison to B (12/39 = 33.3%: p = 0.066), AB (3/9 = 33.3%: p = 0.355), and O secretors (36/112 = 32.1%: p = 0.028). Conclusion This is the first report to document the variable expression of the ABH blood group antigens profiling secretor and non-secretor phenotypes

  2. Abolished ventilation and perfusion of lung caused by blood clot in the left main bronchus: auto-downregulation of pulmonary arterial blood supply.

    PubMed

    Afzelius, P; Bergmann, A; Henriksen, J H

    2015-01-01

    It is generally assumed that the lungs possess arterial autoregulation associated with bronchial obstruction. A patient with pneumonia and congestive heart failure unexpectedly developed frequent haemoptysis. High-resolution CT and diagnostic CT were performed as well as ventilation/perfusion (V/Q) scintigraphy with single-photon emission CT (SPECT)/CT. V/Q SPECT/CT demonstrated abolished ventilation due to obstruction of the left main bronchus and markedly reduced perfusion of the entire left lung, a condition that was completely reversed after removal of a blood clot. We present the first pictorially documented case of hypoxia-induced pulmonary vasoconstriction and flow shift in a main pulmonary artery due to a complete intrinsic obstruction of the ipsilateral main bronchus. The condition is reversible, contingent on being relieved within a few days. PMID:26374773

  3. Comparison of blood flow models and acquisitions for quantitative myocardial perfusion estimation from dynamic CT.

    PubMed

    Bindschadler, Michael; Modgil, Dimple; Branch, Kelley R; La Riviere, Patrick J; Alessio, Adam M

    2014-04-01

    Myocardial blood flow (MBF) can be estimated from dynamic contrast enhanced (DCE) cardiac CT acquisitions, leading to quantitative assessment of regional perfusion. The need for low radiation dose and the lack of consensus on MBF estimation methods motivates this study to refine the selection of acquisition protocols and models for CT-derived MBF. DCE cardiac CT acquisitions were simulated for a range of flow states (MBF = 0.5, 1, 2, 3 ml (min g)(-1), cardiac output = 3, 5, 8 L min(-1)). Patient kinetics were generated by a mathematical model of iodine exchange incorporating numerous physiological features including heterogenenous microvascular flow, permeability and capillary contrast gradients. CT acquisitions were simulated for multiple realizations of realistic x-ray flux levels. CT acquisitions that reduce radiation exposure were implemented by varying both temporal sampling (1, 2, and 3 s sampling intervals) and tube currents (140, 70, and 25 mAs). For all acquisitions, we compared three quantitative MBF estimation methods (two-compartment model, an axially-distributed model, and the adiabatic approximation to the tissue homogeneous model) and a qualitative slope-based method. In total, over 11 000 time attenuation curves were used to evaluate MBF estimation in multiple patient and imaging scenarios. After iodine-based beam hardening correction, the slope method consistently underestimated flow by on average 47.5% and the quantitative models provided estimates with less than 6.5% average bias and increasing variance with increasing dose reductions. The three quantitative models performed equally well, offering estimates with essentially identical root mean squared error (RMSE) for matched acquisitions. MBF estimates using the qualitative slope method were inferior in terms of bias and RMSE compared to the quantitative methods. MBF estimate error was equal at matched dose reductions for all quantitative methods and range of techniques evaluated. This

  4. Comparison of blood flow models and acquisitions for quantitative myocardial perfusion estimation from dynamic CT

    NASA Astrophysics Data System (ADS)

    Bindschadler, Michael; Modgil, Dimple; Branch, Kelley R.; La Riviere, Patrick J.; Alessio, Adam M.

    2014-04-01

    Myocardial blood flow (MBF) can be estimated from dynamic contrast enhanced (DCE) cardiac CT acquisitions, leading to quantitative assessment of regional perfusion. The need for low radiation dose and the lack of consensus on MBF estimation methods motivates this study to refine the selection of acquisition protocols and models for CT-derived MBF. DCE cardiac CT acquisitions were simulated for a range of flow states (MBF = 0.5, 1, 2, 3 ml (min g)-1, cardiac output = 3, 5, 8 L min-1). Patient kinetics were generated by a mathematical model of iodine exchange incorporating numerous physiological features including heterogenenous microvascular flow, permeability and capillary contrast gradients. CT acquisitions were simulated for multiple realizations of realistic x-ray flux levels. CT acquisitions that reduce radiation exposure were implemented by varying both temporal sampling (1, 2, and 3 s sampling intervals) and tube currents (140, 70, and 25 mAs). For all acquisitions, we compared three quantitative MBF estimation methods (two-compartment model, an axially-distributed model, and the adiabatic approximation to the tissue homogeneous model) and a qualitative slope-based method. In total, over 11 000 time attenuation curves were used to evaluate MBF estimation in multiple patient and imaging scenarios. After iodine-based beam hardening correction, the slope method consistently underestimated flow by on average 47.5% and the quantitative models provided estimates with less than 6.5% average bias and increasing variance with increasing dose reductions. The three quantitative models performed equally well, offering estimates with essentially identical root mean squared error (RMSE) for matched acquisitions. MBF estimates using the qualitative slope method were inferior in terms of bias and RMSE compared to the quantitative methods. MBF estimate error was equal at matched dose reductions for all quantitative methods and range of techniques evaluated. This suggests that

  5. Inosculation of blood vessels allows early perfusion and vitality of bladder grafts--implications for bioengineered bladder wall.

    PubMed

    Osborn, Stephanie L; So, Michelle; Hambro, Shannon; Nolta, Jan A; Kurzrock, Eric A

    2015-06-01

    Bioengineered bladder tissue is needed for patients with neurogenic bladder disease as well as for cancer. Current technologies in bladder tissue engineering have been hampered by an inability to efficiently initiate blood supply to the graft, ultimately leading to complications that include graft contraction, ischemia, and perforation. To date, the biological mechanisms of vascularization on transplant have not been suitably investigated for urologic tissues. To better understand the mechanisms of neovascularization on bladder wall transplant, a chimeric mouse model was generated such that angiogenesis and vasculogenesis could be independently assessed in vivo. Green fluorescence protein (GFP) transgenic mice received bone marrow transplants from β-galactosidase (LacZ) transgenic animals and then subsequent bladder wall transplants from wild-type donor mice. Before euthanization, the aorta was infused with fluorescent microbeads (fluorospheres) to identify perfused vessels. The contributions of GFP (angiogenesis) and LacZ (vasculogenesis) to the formation of CD31-expressing blood vessels within the wild-type graft were evaluated by immunohistochemistry at different time points and locations within the graft (proximal, middle, and distal) to provide a spatiotemporal analysis of neovascularization. The GFP index, a measure of angiogenic host ingrowth, was significantly higher at proximal versus mid or distal regions in animals 2-16 weeks post-transplant. However, GFP index did not increase over time in any area. Within 7 days post-transplant, perfusion of primarily wild-type, donor blood vessels in the most distal areas of the graft was observed by intraluminal fluorospheres. In addition, chimeric host-donor (GFP-wild type) blood vessels were evident in proximal areas. The contribution of vasculogenesis to vascularization of the graft was limited, as LacZ cells were not specifically associated with the endothelial cells of blood vessels, but rather found primarily

  6. 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.

  7. 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. PMID:20006720

  8. Evidence of an association between cardiac-locomotor synchronization and lower leg muscle blood perfusion during walking

    PubMed Central

    Takeuchi, Shinta; Nishida, Yusuke; Mizushima, Takashi

    2015-01-01

    [Purpose] The purpose of this study was to investigate whether the occurrence of cardiac-locomotor synchronization (CLS) improves lower leg muscle blood perfusion during walking. [Subjects and Methods] Eleven healthy men were studied while performing two treadmill protocols. The CLS protocol involved subjects walking at the frequency of their heart rate (HR) to induce CLS. The free protocol (reference) involved subjects walking at a self-selected cadence. The treadmill load was identical in the two protocols. Electrocardiographic signals for HR, foot switch signals for step rate and near-infrared spectroscopy (NIRS) signals for total haemoglobin (total Hb) in the lower leg muscles were measured continuously for 10 min after HR reached a steady state. [Results] The mean HR and mean step rate did not differ between the CLS and free protocols. However, total Hb was significantly higher in the CLS protocol than in the free protocol. The rate of increase in total Hb positively correlated with the strength of CLS. [Conclusion] These results suggest that the occurrence of CLS enhances lower leg muscle blood perfusion by increasing the strength of CLS during walking. PMID:26180328

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

    PubMed Central

    Song, Xiao-jing; Zhang, Dong; Wang, Shu-you; Li, Shun-yue

    2014-01-01

    The study was conducted to observe the effect of electroacupuncture (EA) on hepatic blood perfusion (HBP) and vascular regulation. We investigated 60 male anesthetized mice under the following 3 conditions: without EA stimulation (control group); EA stimulation at Zusanli (ST36 group); EA stimulation at nonacupoint (NA group) during 30 min. The HBP was measured using the laser speckle perfusion imaging (LSPI). The level of nitric oxide (NO), endothelin-1 (ET-1), and noradrenaline (NE) in liver tissue was detected by biochemical methods. Results were as follows. At each time point, HBP increase in ST36 group was higher than that in the NA group in anesthetized mice. HBP gradually decreased during 30 min in control group. The level of NO in ST36 group was higher than that in NA group. The level of both ET-1 and NE was the highest in control group, followed by NA group and ST36 group. It is concluded that EA at ST36 could increase HBP possibly by increasing the blood flow velocity (BFV), changing vascular activity, increasing the level of NO, and inhibiting the level of ET-1 in liver tissue. PMID:25140188

  10. 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.

  11. Blood Pressure is Associated With Cerebral Blood Flow Alterations in Patients With T2DM as Revealed by Perfusion Functional MRI

    PubMed Central

    Xia, Wenqing; Rao, Hengyi; Spaeth, Andrea M.; Huang, Rong; Tian, Sai; Cai, Rongrong; Sun, Jie; Wang, Shaohua

    2015-01-01

    Abstract Type 2 diabetes mellitus (T2DM) and hypertension are both associated with cognitive impairment and brain function abnormalities. We investigated whether abnormal cerebral blood flow (CBF) patterns exists in T2DM patients and possible relationships between aberrant CBF and cognitive performance. Furthermore, we examined the influence of hypertension on CBF alterations in T2DM patients. T2DM patients (n = 38) and non-T2DM subjects (n = 40) were recruited from clinics, hospitals, and normal community health screenings. Cerebral blood flow images were collected and analyzed using arterial spin labeling perfusion functional magnetic resonance imaging (fMRI). Regions with major CBF differences between T2DM patients and non-T2DM controls were detected via 1-way ANOVA. The interaction effects between hypertension and T2DM for CBF alterations were also examined. Correlation analyses illustrated the association between CBF values and cognitive performance and between CBF and blood pressure. Compared with non-T2DM controls, T2DM patients exhibited decreased CBF, primarily in the visual area and the default mode network (DMN); decreased CBF in these regions was correlated with cognitive performance. There was a significant interaction effect between hypertension and diabetes for CBF in the precuneus and the middle occipital gyrus. Additionally, blood pressure correlated negatively with CBF in T2DM patients. T2DM patients exhibited reduced CBF in the visual area and DMN. Hypertension may facilitate a CBF decrease in the setting of diabetes. T2DM patients may benefit from blood pressure control to maintain their brain perfusion through CBF preservation. PMID:26632913

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

    PubMed

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

    2015-06-30

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

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

    PubMed Central

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

    2015-01-01

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

  14. Effects of chronic nitric oxide synthase inhibition in cold-restraint and ethanol-induced gastric mucosal damage in rats.

    PubMed

    Qiu, B S; Pfeiffer, C J; Cho, C H

    1996-01-01

    Gastric actions of Nw-nitro-1-arginine methyl ester (L-NAME) were investigated in rats, as this agent is a reliable nitric oxide synthase inhibitor L-NAME solutions were placed in subcutaneous osmotic minipumps which continuously released L-NAME at 0.1, 1.0, 10, or 40 mg/kg/day. L-NAME dose and time-dependently enhanced stress-induced gastric ulceration but did not affect mucosal mast cell population. Ulcerogenic actions of L-NAME were reversed by L-arginine but not by D-arginine. Ten L-NAME treatment also enhanced the ethanol-induced gastric mucosal damage, depressed gastric mucosal blood flow but did not alter gastric mucus, secretory volume, or acid output. It is concluded that in the present models, chronic nitric oxide synthase inhibition enhanced ulcerogenesis by decreasing mucosal resistance due to reduced mucosal blood perfusion. This implicates nitric oxide as a mucosal defense factor which acts in part by maintaining mucosal blood flow. PMID:8626050

  15. Temperature-dependent versus constant-rate blood perfusion modelling in ferromagnetic thermoseed hyperthermia: results with a model of the human prostate.

    PubMed

    Tompkins, D T; Vanderby, R; Klein, S A; Beckman, W A; Steeves, R A; Frye, D M; Paliwal, B R

    1994-01-01

    Finite-element solutions to the Pennes bioheat equation are obtained with a model of a tumour-containing, human prostate and surrounding normal tissues. Simulations of ferromagnetic hyperthermia treatments are conducted on the tissue model in which the prostate is implanted with an irregularly spaced array of thermoseeds. Several combinations of thermoseed temperatures with different Curie points are investigated. Non-uniform, constant-rate blood perfusion models are studied and compared with temperature-dependent descriptions of blood perfusion. Blood perfusions in the temperature-dependent models initially increase with tissue temperature and then decrease at higher temperatures. Simulations with temperature-dependent versus constant-rate blood perfusion models reveal significant differences in temperature distributions in and surrounding the tumour-containing prostate. Results from the simulations include differences (between temperature-dependent and constant-rate models) in (1) the percentage of normal tissue volume and tumour volume at temperatures > 42 degrees C, and (2) temperature descriptors in the tumour (subscript t) and normal (subscript n) tissues including Tmax.t, Tmin.t and Tmax.n. Isotherms and grey-scale contours in the tumour and surrounding normal tissues are presented for four simulations that model a combination of high-temperature thermoseeds. Several simulations show that Tmin.t is between 1.7 and 2.6 degrees C higher and Tmax.n is between 2.1 and 3.3 degrees C higher with a temperature-dependent versus a comparable constant-rate blood perfusion model. The same simulations reveal that the percentages of tumour volume at temperatures > 42 degrees C are between 0 and 68% higher with the temperature-dependent versus the constant-rate perfusion model over all seed combinations studied. In summary, a numerical method is presented which makes it possible to investigate temperature-dependent, continuous functions of blood perfusion in simulations

  16. 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. PMID:24614360

  17. 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

  18. 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. PMID:11702193

  19. [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. PMID:27349086

  20. 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. PMID:23955835

  1. Regional intestinal blood flow and nitric oxide synthase inhibition during sepsis in the rat.

    PubMed Central

    Klemm, K; Moody, F G

    1998-01-01

    OBJECTIVE: Regional circulatory changes in intestinal mucosa were evaluated after the onset of septic shock and the effect of nitric oxide (NO) inhibition on mucosal blood flow was investigated at different locations along the intestine. SUMMARY BACKGROUND DATA: The response of intestinal blood flow to different physiologic and pharmacologic stimuli is known to vary along the intestine, but limited data are available on regional alterations in intestinal blood flow during septic shock. These regional variations in intestinal blood flow could become important because NO inhibition might restore the circulation of one segment of the gut or exacerbate ischemia that may be occurring concomitantly in another segment of the intestine. METHODS: Mucosal blood flow was studied with fluorescent microspheres in conscious unrestrained rats before and 2, 4, and 6 hours after lipopolysaccharide (LPS, 20 mg/kg intraperitoneally) induced sepsis in the presence and absence of the nitric oxide synthase inhibitor N(G)-nitro-L-argininemethylester (L-NAME, 5 mg/kg subcutaneously). RESULTS: Control mucosal blood flow was significantly higher in the ileum than in the duodenum, jejunum, or colon. During LPS-induced sepsis, mucosal blood flow to the ileum decreased and perfusion to the remaining gut was preserved. This was accompanied by hypotension throughout the experiment. L-NAME administration during sepsis prevented hypotension and decreased mucosal blood flow to all segments of small intestine at 2 hours. In this group, mucosal blood flow to the proximal small intestine but not to the ileum returned to baseline levels at 4 and 6 hours. L-NAME alone decreased mucosal blood flow to the small intestine throughout the experiment. CONCLUSIONS: This study indicates that mucosal blood flow alterations during septic shock vary along the intestine, with a significant change only in the ileum, suggesting that perfusion in the small intestine is dependent on physiologic NO production. PMID

  2. 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

  3. 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

  4. Cyclic Helix B Peptide in Preservation Solution and Autologous Blood Perfusate Ameliorates Ischemia-Reperfusion Injury in Isolated Porcine Kidneys

    PubMed Central

    Yang, Cheng; Hosgood, Sarah A.; Meeta, Patel; Long, Yaqiu; Zhu, Tongyu; Nicholson, Michael L.; Yang, Bin

    2015-01-01

    Background There is a critical need to better preserve isolated organs before transplantation. We developed a novel nonerythropoiesis cyclic helix B peptide (CHBP) derived from erythropoietin, which has potent tissue protection and prolonged serum stability. The renoprotection and potential mechanism of CHBP were evaluated in a kidney preservation model. Materials and Methods Porcine kidneys (n = 5) subjected to 20-minute warm ischemia were retrieved and flushed with hyperosmolar citrate to mimic deceased donation. The kidneys and autologous blood ± 10.56 nmol/L CHBP were placed in cold storage (CS) for 18 hours. These kidneys were then normothermically hemoreperfused for 3 hours using an isolated organ perfusion system. The renal function and structure, apoptosis, inflammation, and expression of caspase-3 and heat shock protein 70 (HSP70) were assessed. Results Cyclic helix B peptide significantly increased the renal blood flow, oxygen consumption, and urine output during reperfusion, but decreased serum potassium and renal tissue damage. Apoptotic cells were significantly decreased in the tubular areas, but increased in the lumens and interstitial areas in the post-CS and postreperfused kidneys, whereas myeloperoxidase+ cells were reduced. In addition, the expression of both caspase-3 precursor and active subunits was downregulated by CHBP in reperfused kidneys. However, HSP70 was upregulated in the post-CS and postreperfused kidneys treated with CHBP. Conclusions Cyclic helix B peptide administered into preservation and reperfusion solutions ameliorated renal ischemia-reperfusion injury, which might be associated with decreased apoptosis, inflammation and caspase-3, but increased HSP70. This novel preservation approach using CHBP may be applied in a porcine kidney transplant model and potential human donor kidney preservation.

  5. 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.

  6. 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. PMID:17438835

  7. 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

  8. 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

  9. A perfusion chamber developed to investigate platelet interaction in flowing blood with human vessel wall cells, their extracellular matrix, and purified components.

    PubMed

    Sakariassen, K S; Aarts, P A; de Groot, P G; Houdijk, W P; Sixma, J J

    1983-10-01

    A flat perfusion chamber was developed to study the interaction of blood platelets in flowing blood with cultured human vessel wall cells, their connective tissue matrix, and isolated connective tissue components at defined shear rate conditions. A cover slip covered with endothelial cells or extracellular matrix components was introduced into the chamber. Laser-Doppler velocimetry showed a symmetrical flow profile at flow rates between 50 and 150 ml/min (wall shear rate 300 to 1100 sec-1). Platelet deposition was estimated by using blood platelets labeled with indium-111 or by a morphometric method. Blood platelets did not adhere to endothelial cells at wall shear rates of 765 sec-1 and the endothelial cells remained attached for at least 10 min of perfusion. In preconfluent cultures of endothelial cells, blood platelets adhered to extracellular material in areas between the cells. Removal of endothelial cells by treatment with 0.5% Triton X-100 induced increased platelet adherence with a preference for certain, as yet unidentified, fibrillar structures of the extracellular matrix. Platelet adherence to equine collagen was also studied after coating the cover slips by spraying of small collagen droplets followed by air drying. Platelet adherence and the subsequent platelet aggregate formation occurred predominantly along visible collagen fibers. These studies showed that this perfusion chamber has a laminar and symmetrical flow allowing qualitative and quantitative investigation of platelet interaction with endothelial cells, their extracellular matrix, and pure connective tissue components. A variety of wall shear rates and exposure times can be applied at controlled conditions without removing cells or extracellular material. PMID:6619647

  10. Effects of hydrochloric acid on duodenal and jejunal mucosal permeability in the rat

    SciTech Connect

    Nylander, O.; Kvietys, P.; Granger, D.N. )

    1989-10-01

    The effects of various concentrations of hydrochloric acid (1, 5, 10, and 100 mM) on mucosal permeability and acid disappearance (H+-dis) in duodenum and jejunum were studied in anesthetized rats. Mucosal permeability was assessed by measuring blood-to-lumen clearance of 51Cr-labeled EDTA (ED-Cl). Luminal alkalinization (LA) and H+-dis were determined by backtitration. ED-Cl was stable during saline perfusion and was not affected by changes in intestinal blood flow. Basal ED-Cl was four times higher in duodenum than in jejunum. Mucosal permeability of both duodenum and jejunum was not altered by 1 mM HCl. However, 5 mM HCl induced a 3.3-fold increase (P less than 0.001) in ED-Cl in jejunum but was without effect in duodenum. A 15-fold increase in ED-Cl was obtained in jejunum and a doubling (P less than 0.001) in ED-Cl was observed in duodenum when HCl concentration was increased to 10 mM HCl. One hundred millimolar HCl induced large increases of ED-Cl in both segments. The twofold increase of ED-Cl in response to 10 mM HCl in duodenum was completely reversible, whereas ED-Cl in jejunum was three to four times higher (P less than 0.05) than preacid levels 60 min after cessation of acid perfusion. The net increase in jejunal ED-Cl obtained after acid exposure was closely correlated (r = 0.99) with the net increase in LA, indicating leakage of interstitial fluid into the luminal solution. LA (saline perfusion) and H+-dis (HCl perfusion) were significantly higher in duodenum than in jejunum.

  11. NADH fluorescence/UV reflectance ratio provides a semi-quantitative measure for NADH fluorometry of blood-perfused rat heart

    NASA Astrophysics Data System (ADS)

    Coremans, J. M. C. C.; Ince, C.; Bruining, Hajo A.; Puppels, Gerwin J.

    1996-12-01

    A procedure for semi-quantitative analysis of NADH fluorescence image is presented which enables non-invasive monitoring of the metabolic state of tissue in vivo. In blood perfused tissue, the NADH fluorescence intensity can be disturbed by movement and by hemodynamic and oximetric effects. These factors alter the tissue absorbance of UV excitation light and thereby the NADH fluorescence excitation efficiency. Combination of the theories of front- face fluorimetry and Kubelka and Munk for description of NADH fluorescence (FNADH) and UV reflectance (R365d) of optically thick samples, predicts that the FNADH/R365d ratio provides adequate compensation for changes in tissue absorbance. The validity of this correction procedure is verified in tissue phantoms, in Langendorff perfused rat hearts and for rat hearts in vivo. Movement artifacts were eliminated using a CCD video camera with a biprism configuration for simultaneous measurement of fluorescence and reflectance images. Therefore, the FNADH/Rd ratio can be used to monitor the metabolic state of blood perfused tissue.

  12. Mucosal immunoglobulins.

    PubMed

    Woof, Jenny M; Mestecky, Jiri

    2005-08-01

    Due to their vast surface area, the mucosal surfaces of the body represent a major site of potential attack by invading pathogens. The secretions that bathe mucosal surfaces contain significant levels of immunoglobulins (Igs), which play key roles in immune defense of these surfaces. IgA is the predominant antibody class in many external secretions and has many functional attributes, both direct and indirect, that serve to prevent infective agents such as bacteria and viruses from breaching the mucosal barrier. This review details current understanding of the structural and functional characteristics of IgA, including interaction with specific receptors (such as Fc(alpha)RI, Fc(alpha)/microR, and CD71) and presents examples of the means by which certain pathogens circumvent the protective properties of this important Ig. PMID:16048542

  13. Detection and analysis of temperature-sensitive dermal blood perfusion dynamics and distribution by a hybrid camera system.

    PubMed

    Blanik, N; Paul, M; Blazek, V; Leonhardt, S

    2015-08-01

    In this paper we present an application of two optical imaging modalities for non-invasive assessment of dermal perfusion. This hybrid setup consists of a photo-plethysmographic camera sensing in the visible spectrum and a thermal camera sensing in the infrared-C-band. This allows to combine the information of both sources complementarily: The extracted perfusion index as well as the skin surface temperature. The feasibility of the presented system is tested in two studies with local temperature stress on the forehead of a subject. In the first, a local cooling on the subject's forehead is monitored and further analyzed. In the second, skin perfusion reactions to heat are considered. For both experiments the results are compared to baseline measurements and non-affected areas in the field of view of the cameras. As results, the dependencies between temperature and perfusion change are presented. Further, influences of the stressor can be visualized in functional mappings of calculated perfusion indices. For the performed test, a linear correlation between temperature and perfusion change is obtained. PMID:26736773

  14. 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. PMID:20544714

  15. The effect of high- and low-frequency H-wave therapy upon skin blood perfusion: evidence of frequency-specific effects.

    PubMed

    McDowell, B C; McElduff, C; Lowe, A S; Walsh, D M; Baxter, G D

    1999-11-01

    The current study was designed to assess the putative physiological effects of H-wave therapy (HWT, a mode of therapeutic electro-stimulation) on skin blood flow in humans and to determine the relevance of frequency to any such effects. Laser Doppler flowmetry was used to record changes in blood perfusion on the dominant forearm of healthy human volunteers (n=36), who were each assigned, under randomized double blind conditions, to one of three experimental groups: placebo or HWT at 2 or 60 Hz. HWT stimulation was applied for 20 min, during which time concomitant skin temperature was recorded using three surface skin thermistors. Statistical analysis of perfusion measurement and skin temperature changes pre-, during and for up to 18 min post-HWT stimulation showed a highly significant increase in skin blood flow in the 2 Hz group when compared to placebo and 60 Hz (Pblood flow, a finding relevant for clinicians working in the field of tissue repair. PMID:10583337

  16. 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

  17. 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

    2015-11-01

    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.

  18. 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.

  19. Visualization of hypertrophied papillary muscle mimicking left ventricular mass on gated blood pool and T1-201 myocardial perfusion imaging

    SciTech Connect

    Bunko, H.; Nakajima, K.; Tonami, N.; Asanoi, H.; Hisada, K.

    1981-12-01

    A sixty-year old man with acute myocardial infarction was incidentally found to have a hypertrophied anterolateral papillary muscle (ALPPM) of the left ventricle on gated blood pool (GBP) and T1-201 myocardial perfusion images. Hypertrophy of the ALPPM was visualized as a movable defect in the lateral basal area on GBP imaging throughout the cardiac cycle and on the TI-201 study as a radionuclide accumulating structure, consistent with the defect in the GBP. A combination of these findings may suggest the presence of a hypertrophied papillary muscle of the left ventricle.

  20. 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. PMID:9052297

  1. 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 Central

    WANG, CHUAN; CHEN, YING-GE; GAO, JIAN-LI; LYU, GUI-YUAN; SU, JIE; ZHANG, QI; JI, XIN; YAN, JI-ZHONG; QIU, QIAO-LI; ZHANG, YUE-LI; LI, LIN-ZI; XU, HAN-TING; CHEN, SU-HONG

    2015-01-01

    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. PMID:26622565

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. [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. PMID:17176901

  5. Lung Ventilation/Perfusion Scan

    MedlinePlus

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

  6. 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

  7. 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. PMID:24462603

  8. Non-invasive and quantitative evaluation of peripheral vascular resistances in rats by combined NMR measurements of perfusion and blood pressure using ASL and dynamic angiography.

    PubMed

    Ménard, Jacques C; Giacomini, Eric; Baligand, Céline; Fromes, Yves; Carlier, Pierre G

    2010-02-01

    The in vivo determination of peripheral vascular resistances (VR) is crucial for the assessment of arteriolar function. It requires simultaneous determination of organ perfusion (F) and arterial blood pressure (BP). A fully non-invasive method was developed to measure systolic and diastolic BP in the caudal artery of rats based on dynamic NMR angiography. A good agreement was found between the NMR approach and the gold standard techniques (linear regression slope = 0.98, R(2) = 0.96). This method and the ASL-MRI measurement of skeletal muscle perfusion were combined into one single NMR experiment to quantitatively evaluate the local vascular resistances in the calf muscle of anaesthetized rats, in vivo and non-invasively 1) at rest: VR = 7.0 +/- 1.0 mmHg x min 100 g x ml(-1), F = 13 +/- 3 ml min(-1) x 100 g(-1) and mean BP (MBP) = 88 +/- 10 mmHg; 2) under vasodilator challenge (milrinone): VR = 3.7 +/- 1.1 mmHg min x 100 g ml(-1), F = 21 +/- 4 ml min(-1) x 100 g(-1) and MBP = 75 +/- 14 mmHg; 3) under vasopressor challenge (norepinephrine): VR = 9.8 +/- 1.2 mmHg min 100 g ml(-1), F = 14 +/- 3 ml min(-1) x 100 g(-1) and MBP = 137 +/- 2 mmHg. PMID:19795372

  9. Improvements in the Quantitative Assessment of Cerebral Blood Volume and Flow with the Removal of Vessel Voxels from MR Perfusion Images

    PubMed Central

    Teng, Michael Mu Huo; Cho, I-Chieh; Kao, Yi-Hsuan; Chuang, Chi-Shuo; Chiu, Fang-Ying; Chang, Feng-Chi

    2013-01-01

    Objective. To improve the quantitative assessment of cerebral blood volume (CBV) and flow (CBF) in the brain voxels from MR perfusion images. Materials and Methods. Normal brain parenchyma was automatically segmented with the time-to-peak criteria after cerebrospinal fluid removal and preliminary vessel voxel removal. Two scaling factors were calculated by comparing the relative CBV and CBF of the segmented normal brain parenchyma with the absolute values in the literature. Using the scaling factors, the relative values were converted to the absolute CBV and CBF. Voxels with either CBV > 8 mL/100 g or CBF > 100 mL/100 g/min were characterized as vessel voxels and were excluded from the quantitative measurements. Results. The segmented brain parenchyma with normal perfusion was consistent with the angiographic findings for each patient. We confirmed the necessity of dual thresholds including CBF and CBV for proper removal of vessel voxels. The scaling factors were 0.208 ± 0.041 for CBV, and 0.168 ± 0.037, 0.172 ± 0.037 for CBF calculated using standard and circulant singular value decomposition techniques, respectively. Conclusion. The automatic scaling and vessel removal techniques provide an alternative method for obtaining improved quantitative assessment of CBV and CBF in patients with thromboembolic cerebral arterial disease. PMID:23586033

  10. 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. PMID:23737171

  11. Importance of capillary perfusion.

    PubMed

    Hardaway, R M

    1979-11-01

    Perfusion is more critical than oxygen in the maintenance of cell viability. A high hematocrit or high fibrinogen level increases blood viscosity and predisposes to disseminated intravascular coagulation. It is recommended that a hematocrit of about 30 be maintained in periods of circulatory stress such as shock or extracorporeal circulation. PMID:495856

  12. 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. PMID:25160672

  13. Oral mucositis - self-care

    MedlinePlus

    Cancer treatment - mucositis; Cancer treatment - mouth pain; Cancer treatment - mouth sores; Chemotherapy - mucositis; Chemotherapy - mouth pain; Chemotherapy - mouth sores; Radiation therapy - mucositis; Radiation therapy - mouth pain; Radiation ...

  14. Electroencephalography reveals lower regional blood perfusion and atrophy of the temporoparietal network associated with memory deficits and hippocampal volume reduction in mild cognitive impairment due to Alzheimer’s disease

    PubMed Central

    Moretti, Davide Vito

    2015-01-01

    Background An increased electroencephalographic (EEG) upper/lower alpha power ratio has been associated with less regional blood perfusion, atrophy of the temporoparietal region of the brain, and reduction of hippocampal volume in subjects affected by mild cognitive impairment due to Alzheimer’s disease as compared with subjects who do not develop the disease. Moreover, EEG theta frequency activity is quite different in these groups. This study investigated the correlation between biomarkers and memory performance. Methods EEG α3/α2 power ratio and cortical thickness were computed in 74 adult subjects with prodromal Alzheimer’s disease. Twenty of these subjects also underwent assessment of blood perfusion by single-photon emission computed tomography (SPECT). Pearson’s r was used to assess the correlation between cortical thinning, brain perfusion, and memory impairment. Results In the higher α3/α2 frequency power ratio group, greater cortical atrophy and lower regional perfusion in the temporoparietal cortex was correlated with an increase in EEG theta frequency. Memory impairment was more pronounced in the magnetic resonance imaging group and SPECT groups. Conclusion A high EEG upper/low alpha power ratio was associated with cortical thinning and less perfusion in the temporoparietal area. Moreover, atrophy and less regional perfusion were significantly correlated with memory impairment in subjects with prodromal Alzheimer’s disease. The EEG upper/lower alpha frequency power ratio could be useful for identifying individuals at risk for progression to Alzheimer’s dementia and may be of value in the clinical context. PMID:25750526

  15. 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.

  16. 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

  17. Engineering a Dual-Layer Chitosan-Lactide Hydrogel To Create Endothelial Cell Aggregate-Induced Microvascular Networks In Vitro and Increase Blood Perfusion In Vivo.

    PubMed

    Kim, Sungwoo; Kawai, Toshiyuki; Wang, Derek; Yang, Yunzhi

    2016-08-01

    Here, we report the use of chemically cross-linked and photo-cross-linked hydrogels to engineer human umbilical vein endothelial cell (HUVEC) aggregate-induced microvascular networks to increase blood perfusion in vivo. First, we studied the effect of chemically cross-linked and photo-cross-linked chitosan-lactide hydrogels on stiffness, degradation rates, and HUVEC behaviors. The photo-cross-linked hydrogel was relatively stiff (E = ∼15 kPa) and possessed more compact networks, denser surface texture, and lower enzymatic degradation rates than the relatively soft, chemically cross-linked hydrogel (E = ∼2 kPa). While both hydrogels exhibited nontoxicity, the soft chemically cross-linked hydrogels expedited the formation of cell aggregates compared to the photo-cross-linked hydrogels. Cells on the less stiff, chemically cross-linked hydrogels expressed more matrix metalloproteinase (MMP) activity than the stiffer, photo-cross-linked hydrogel. This difference in MMP activity resulted in a more dramatic decrease in mechanical stiffness after 3 days of incubation for the chemically cross-linked hydrogel, as compared to the photo-cross-linked one. After determining the physical and biological properties of each hydrogel, we accordingly engineered a dual-layer hydrogel construct consisting of the relatively soft, chemically cross-linked hydrogel layer for HUVEC encapsulation, and the relatively stiff, acellular, photo-cross-linked hydrogel for retention of cell-laden microvasculature above. This dual-layer hydrogel construct enabled a lasting HUVEC aggregate-induced microvascular network due to the combination of stable substrate, enriched cell adhesion molecules, and extracellular matrix proteins. We tested the dual-layer hydrogel construct in a mouse model of hind-limb ischemia, where the HUVEC aggregate-induced microvascular networks significantly enhanced blood perfusion rate to ischemic legs and decreased tissue necrosis compared with both no treatment and

  18. Computational micro-scale model of control of extravascular water and capillary perfusion in the air blood barrier.

    PubMed

    Mazzuca, Enrico; Aliverti, Andrea; Miserocchi, Giuseppe

    2016-07-01

    A computational model of a morphologically-based alveolar capillary unit (ACU) in the rabbit is developed to relate lung fluid balance to mechanical forces between capillary surface and interstitium during development of interstitial edema. We hypothesize that positive values of interstitial liquid pressure Pliq impact on capillary transmural pressure and on blood flow. ACU blood flow, capillary recruitment and filtration are computed by modulating vascular and interstitial pressures. Model results are compared with experimental data of Pliq increasing from ~-10 (control) up to ~4cmH2O in two conditions, hypoxia and collagenase injection. For hypoxia exposure, fitting data requires a linear increase in hydraulic conductivity Lp and capillary pressure PC, that fulfils the need of increase in oxygen delivery. For severe fragmentation of capillary endothelial barrier (collagenase injection), fitting requires a rapid increase in both hydraulic and protein permeability, causing ACU de-recruitment, followed by an increase in PC as a late response to restore blood flow. In conclusion, the model allows to describe the lung adaptive response to edemagenic perturbations; the increase in Pliq, related to the low interstitial compliance, provides an efficient control of extravascular water, by limiting microvascular filtration. PMID:27059893

  19. Hydrostatic determinants of cerebral perfusion

    SciTech Connect

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

    1986-05-01

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

  20. 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 Central

    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.

    2014-01-01

    Background 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. Methods 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 1 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 hours 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. Results Each increase in the number of genetic modifications was associated with additional prolongation of lung xenograft survival. Lungs that exhibited survival to 4 hours 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. Conclusion 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

  1. 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

  2. Mucosal dendritic cells shape mucosal immunity

    PubMed Central

    Chang, Sun-Young; Ko, Hyun-Jeong; Kweon, Mi-Na

    2014-01-01

    Dendritic cells (DCs) are key modulators that shape the immune system. In mucosal tissues, DCs act as surveillance systems to sense infection and also function as professional antigen-presenting cells that stimulate the differentiation of naive T and B cells. On the basis of their molecular expression, DCs can be divided into several subsets with unique functions. In this review, we focus on intestinal DC subsets and their function in bridging the innate signaling and adaptive immune systems to maintain the homeostasis of the intestinal immune environment. We also review the current strategies for manipulating mucosal DCs for the development of efficient mucosal vaccines to protect against infectious diseases. PMID:24626170

  3. 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.

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

    PubMed Central

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

    2014-01-01

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

  5. Myocardial perfusion imaging using contrast echocardiography.

    PubMed

    Pathan, Faraz; Marwick, Thomas H

    2015-01-01

    Microbubbles are an excellent intravascular tracer, and both the rate of myocardial opacification (analogous to coronary microvascular perfusion) and contrast intensity (analogous to myocardial blood volume) provide unique insights into myocardial perfusion. A strong evidence base has been accumulated to show comparability with nuclear perfusion imaging and incremental diagnostic and prognostic value relative to wall motion analysis. This technique also provides the possibility to measure myocardial perfusion at the bedside. Despite all of these advantages, the technique is complicated, technically challenging, and has failed to scale legislative and financial hurdles. The development of targeted imaging and therapeutic interventions will hopefully rekindle interest in this interesting modality. PMID:25817740

  6. Chlamydia trachomatis Antibody Testing in Vaginal Mucosal Material versus Blood Samples of Women Attending a Fertility Clinic and an STI Clinic

    PubMed Central

    van den Broek, Ingrid V. F.; Land, Jolande A.; van Bergen, Jan E. A. M.; Morré, Servaas A.; van der Sande, Marianne A. B.

    2014-01-01

    Background. Chlamydia infections often follow an asymptomatic course but may damage the reproductive tract. Chlamydia antibodies in serum are used as markers for past infections and can relate to tubal pathology and infertility. This “proof of principle” study aimed to assess whether Chlamydia antibodies are detectable in easier to obtain, noninvasive, vaginal mucosa samples and relate to current or past infection. Methods. We compared outcomes of Chlamydia IgG and IgA antibody tests in serum and vaginal mucosal swabs in (a) 77 women attending a fertility clinic, of whom 25 tested positive for serum-IgG and (b) 107 women visiting an STI centre, including 30 Chlamydia PCR-positive subjects. Results. In the STI clinic, active Chlamydia infections were linked to serum-IgG and serum-IgA (P < 0.001) and mucosa-IgA (P < 0.001), but not mucosa-IgG. In the fertility clinic, mucosa-IgG had stronger correlations with serum-IgG (P = 0.02) than mucosa-IgA (P = 0.06). Women with tubal pathology or Chlamydia history more commonly had serum-IgG and mucosa-IgA (both P < 0.001), whereas this link was weaker for mucosa-IgG (P = 0.03). Conclusion. Chlamydia IgG and IgA are detectable in vaginal mucosal material. Serum-IgG had stronger associations with current or past infections. Mucosa-IgA also showed associations with (past) infection and complications. IgA presence in vaginal mucosa warrants further epidemiological studies. PMID:24757446

  7. 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.

  8. Blood

    MedlinePlus

    ... solid part of your blood contains red blood cells, white blood cells, and platelets. Red blood cells (RBC) deliver oxygen from your lungs to your tissues and organs. White blood cells (WBC) fight infection and are part of your ...

  9. 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. PMID:21492942

  10. Why mucosal health?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Autoradiographic study of the regional distribution of gastric blood flow in portal hypertensive rats

    SciTech Connect

    Geraghty, J.G.; Angerson, W.J.; Carter, D.C. )

    1989-11-01

    This study measures regional gastric blood flow in portal hypertensive rats at three separate periods after portal vein ligation using quantitative autoradiography with 14C-labeled iodoantipyrine. The level of corpus mucosal blood flow was significantly reduced in 3-day portal vein-ligated animals compared with sham-operated control animals (30.4 +/- 2.3 vs. 47.1 +/- 5.6 ml/100 g.min). There was no significant difference in corpus mucosal blood flow between portal vein-ligated and sham-operated animals at 7- and 28-day periods, although the level of perfusion was higher in the 28-day portal vein-ligated group. There was no significant difference in antral mucosal or muscle blood flow between portal hypertensive and control animals at any of the study periods. We conclude that the acute period after portal vein ligation is associated with a reduced corpus mucosal microcirculation but that this effect is not sustained in portal hypertensive animals studied at later intervals after portal vein ligation.

  12. 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. PMID:26980755

  13. Gasoline-induced mucositis

    SciTech Connect

    Hoffman, D.L.; Swanson, B.Z. Jr.; Lutins, N.D.

    1980-02-01

    Gasoline-induced mucositis may become more common because of fuel shortages or increased fuel cost. Dentists should, therefore, consider this oral irritant in the differential diagnosis of oral lesions.

  14. Mucosal Health in Aquaculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Nasal mucosal biopsy

    MedlinePlus

    Biopsy - nasal mucosa; Nose biopsy ... to fast for a few hours before the biopsy. ... Nasal mucosal biopsy is usually done when abnormal tissue is seen during examination of the nose. It may also be done ...

  16. Mucosal delivery of vaccines.

    PubMed

    Del Giudice, G; Pizza, M; Rappuoli, R

    1999-09-01

    Oral delivery represents one of the most pursued approaches for large-scale human vaccination. Due to the different characteristics of mucosal immune response, as compared with systemic response, oral immunization requires particular methods of antigen preparation and selective strategies of adjuvanticity. In this paper, we describe the preparation and use of genetically detoxified bacterial toxins as mucosal adjuvants and envisage the possibility of their future exploitation for human oral vaccines. PMID:10525451

  17. 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…

  18. 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

  19. Blood

    MedlinePlus

    ... fight infection and are part of your body's defense system. Platelets help blood to clot when you have a cut or wound. Bone marrow, the spongy material inside your bones, makes new blood cells. Blood cells ...

  20. Pulmonary perfusion during anesthesia and mechanical ventilation.

    PubMed

    Hedenstierna, G

    2005-06-01

    Cardiac output and the pulmonary perfusion can be affected by anesthesia and by mechanical ventilation. The changes contribute to impeded oxygenation of the blood. The major determinant of perfusion distribution in the lung is the relation between alveolar and pulmonary capillary pressures. Perfusion increases down the lung, due to hydrostatic forces. Since atelectasis is located in dependent lung regions, perfusion of non-ventilated lung parenchyma is common, producing shunt of around 8-10% of cardiac output. In addition, non-gravitational inhomogeneity of perfusion, that can be greater than the gravitational inhomogeneity, adds to impeded oxygenation of blood. Essentially all anaesthetics exert some, although mild, cardiodepressant action with one exception, ketamine. Ketamine may also increase pulmonary artery pressure, whereas other agents have little effect on pulmonary vascular tone. Mechanical ventilation impedes venous return and pushes blood flow downwards to dependent lung regions, and the effect may be striking with higher levels of PEEP. During one-lung anesthesia, there is shunt blood flow both in the non-ventilated and the ventilated lung, and shunt can be much larger in the ventilated lung than thought of. Recruitment manoeuvres shall be directed to the ventilated lung and other physical and pharmacological measures can be taken to manipulate blood flow in one lung anesthesia. PMID:15886595

  1. Tissue blood flow mapping

    NASA Astrophysics Data System (ADS)

    Nilsson, G. E.

    1997-01-01

    The operating principles of Laser Doppler Perfusion Imaging (LDPI) for visualization of the tissue blood perfusion are explained. Using this emerging technology skin perfusion has been investigated in healthy volunteers and in patients with various conditions that affect skin blood flow. LDPI is anticipated to be particularly useful in evaluation of peripheral circulation in diabetics, as an objective tool in irritancy patch testing, assessment of burnt skin and visualization of spot-wise hyperperfusion in breast skin in association with carcinoma.

  2. Pulmonary ventilation/perfusion scan

    MedlinePlus

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

  3. Retrograde heart perfusion: the Langendorff technique of isolated heart perfusion.

    PubMed

    Bell, Robert M; Mocanu, Mihaela M; Yellon, Derek M

    2011-06-01

    In the late 19th century, a number of investigators were working on perfecting isolated heart model, but it was Oscar Langendorff who, in 1895, pioneered the isolated perfused mammalian heart. Since that time, the Langendorff preparation has evolved and provided a wealth of data underpinning our understanding of the fundamental physiology of the heart: its contractile function, coronary blood flow regulation and cardiac metabolism. In more recent times, the procedure has been used to probe pathophysiology of ischaemia/reperfusion and disease states, and with the dawn of molecular biology and genetic manipulation, the Langendorff perfused heart has remained a stalwart tool in the study of the impact upon the physiology of the heart by pharmacological inhibitors and targeted deletion or up-regulation of genes and their impact upon intracellular signalling and adaption to clinically relevant stressful stimuli. We present here the basic structure of the Langendorff system and the fundamental experimental rules which warrant a viable heart preparation. In addition, we discuss the use of the isolated retrograde perfused heart in the model of ischaemia-reperfusion injury ex-vivo, and its applicability to other areas of study. The Langendorff perfusion apparatus is highly adaptable and this is reflected not only in the procedure's longevity but also in the number of different applications to which it has been turned. PMID:21385587

  4. Respiratory mucosal permeability in asthma

    SciTech Connect

    Elwood, R.K.; Kennedy, S.; Belzberg, A.; Hogg, J.C.; Pare, P.D.

    1983-09-01

    The permeability of respiratory mucosa to technetium-labeled diethylenetriamine pentacetic acid (/sup 99m/Tc-DTPA) was measured in 10 clinically stable chronic asthmatics and the results were compared with those in 9 nonasthmatic control subjects. Nonspecific bronchial reactivity was measured using methacholine, and the PC20 was calculated. The intrapulmonary distribution and dose of the inhaled /sup 99m/Tc-DTPA was determined by a gamma camera and the half-life of the aerosolized label in the lung was calculated. The accumulation of radioactivity in the blood was monitored and a permeability index was calculated at 10, 25, and 60 min after aerosolization. Despite marked differences in airway reactivity, no differences in either parameter of permeability could be detected between the asthmatics and the control group. It is concluded that clinically stable asthmatics do not demonstrate increase mucosal permeability to small solutes when compared with normal subjects.

  5. Clinical Neuroimaging Using Arterial Spin-Labeled Perfusion MRI

    PubMed Central

    Wolf, Ronald L.; Detre, John A.

    2007-01-01

    SUMMARY The two most common methods for measuring perfusion with MRI are based on dynamic susceptibility contrast (DSC) and arterial spin labeling (ASL). Although clinical experience to date is much more extensive with DSC perfusion MRI, ASL methods offer several advantages. The primary advantages are that completely noninvasive absolute cerebral blood flow (CBF) measurements are possible with relative insensitivity to permeability, and that multiple repeated measurements can be obtained to evaluate one or more interventions or to perform perfusion-based functional MRI. ASL perfusion and perfusion-based fMRI methods have been applied in many clinical settings, including acute and chronic cerebrovascular disease, CNS neoplasms, epilepsy, aging and development, neurodegenerative disorders, and neuropsychiatric diseases. Recent technical advances have improved the sensitivity of ASL perfusion MRI, and increasing use is expected in the coming years. This review focuses on ASL perfusion MRI and applications in clinical neuroimaging. PMID:17599701

  6. A Phantom Tissue System for the Calibration of Perfusion Measurements

    PubMed Central

    Mudaliar, Ashvinikumar V.; Ellis, Brent E.; Ricketts, Patricia L.; Lanz, Otto I.; Scott, Elaine P.; Diller, Thomas E.

    2008-01-01

    A convenient method for testing and calibrating surface perfusion sensors has been developed. A phantom tissue model is used to simulate the nondirectional blood flow of tissue perfusion. A computational fluid dynamics (CFD) model was constructed in Fluent® to design the phantom tissue and validate the experimental results. The phantom perfusion system was used with a perfusion sensor based on clearance of thermal energy. A heat flux gage measures the heat flux response of tissue when a thermal event (convective cooling) is applied. The blood perfusion and contact resistance are estimated by a parameter estimation code. From the experimental and analytical results, it was concluded that the probe displayed good measurement repeatability and sensitivity. The experimental perfusion measurements in the tissue were in good agreement with those of the CFD models and demonstrated the value of the phantom tissue system. PMID:19045509

  7. 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.

  8. A method of thymic perfusion and its evaluation

    PubMed Central

    Ekwueme, O.

    1973-01-01

    The development and evaluation of a method of isolated ex vivo perfusion of the rabbit thymus using diluted autologous blood is described. The data indicate that the viability of the preparation is maintained at a satisfactory level during the period of perfusion. These results suggest that the isolated perfused thymus would be a useful new approach to studies of thymus function. ImagesFig. 2Fig. 8Fig. 9Fig. 10Fig. 11 PMID:4747584

  9. 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

  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.

  11. Perfusion CT imaging of the liver: review of clinical applications

    PubMed Central

    Oğul, Hayri; Kantarcı, Mecit; Genç, Berhan; Pirimoğlu, Berhan; Çullu, Neşat; Kızrak, Yeşim; Yılmaz, Ömer; Karabulut, Nevzat

    2014-01-01

    Perfusion computed tomography (CT) has a great potential for determining hepatic and portal blood flow; it offers the advantages of quantitative determination of lesion hemodynamics, distinguishing malignant and benign processes, as well as providing morphological data. Many studies have reported the use of this method in the assessment of hepatic tumors, hepatic fibrosis associated with chronic liver disease, treatment response following radiotherapy and chemotherapy, and hepatic perfusion changes after radiological or surgical interventions. The main goal of liver perfusion imaging is to improve the accuracy in the characterization of liver disorders. In this study, we reviewed the clinical application of perfusion CT in various hepatic diseases. PMID:24834487

  12. 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.

  13. 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.

  14. Perfusion harmonic imaging of the human brain

    NASA Astrophysics Data System (ADS)

    Metzler, Volker H.; Seidel, Guenter; Wiesmann, Martin; Meyer, Karsten; Aach, Til

    2003-05-01

    The fast visualisation of cerebral microcirculation supports diagnosis of acute cerebrovascular diseases. However, the commonly used CT/MRI-based methods are time consuming and, moreover, costly. Therefore we propose an alternative approach to brain perfusion imaging by means of ultrasonography. In spite of the low signal/noise-ratio of transcranial ultrasound and the high impedance of the skull, flow images of cerebral blood flow can be derived by capturing the kinetics of appropriate contrast agents by harmonic ultrasound image sequences. In this paper we propose three different methods for human brain perfusion imaging, each of which yielding flow images indicating the status of the patient's cerebral microcirculation by visualising local flow parameters. Bolus harmonic imaging (BHI) displays the flow kinetics of bolus injections, while replenishment (RHI) and diminution harmonic imaging (DHI) compute flow characteristics from contrast agent continuous infusions. RHI measures the contrast agents kinetics in the influx phase and DHI displays the diminution kinetics of the contrast agent acquired from the decay phase. In clinical studies, BHI- and RHI-parameter images were found to represent comprehensive and reproducible distributions of physiological cerebral blood flow. For DHI it is shown, that bubble destruction and hence perfusion phenomena principally can be displayed. Generally, perfusion harmonic imaging enables reliable and fast bedside imaging of human brain perfusion. Due to its cost efficiency it complements cerebrovascular diagnostics by established CT/MRI-based methods.

  15. Augmentation of the gastric mucosal defense mechanism induced by KW-5805, a novel antiulcer agent.

    PubMed

    Tanaka, H; Kosaka, N; Tomaru, A; Shuto, K; Ogihara, T; Sato, N

    1989-01-01

    KW-5805 (a new antiulcer agent), given p. o. at 30 mg/kg to rats, significantly increased the amount of gastric adherent mucus and mucosal glycoproteins. Gastric mucosal glucosamine synthetase activity was significantly enhanced by KW-5805 (30 mg/kg, p. o.). KW-5805 (10, 30 mg/kg, p. o.) significantly suppressed the decrease of gastric mucosal blood volume and oxygen sufficiency induced by hemorrhagic shock. The agent also significantly inhibited the extravasation of Evans blue into the gastric mucosa after ischemia-reinfusion. In conclusion, KW-5805 increased biosynthesis, storage and secretion of gastric mucus and improved the gastric mucosal hemodynamics. PMID:2595291

  16. 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.

  17. Comparing Normothermic Machine Perfusion Preservation With Different Perfusates on Porcine Livers From Donors After Circulatory Death.

    PubMed

    Liu, Q; Nassar, A; Farias, K; Buccini, L; Mangino, M J; Baldwin, W; Bennett, A; O'Rourke, C; Iuppa, G; Soliman, B G; Urcuyo-Llanes, D; Okamoto, T; Uso, T D; Fung, J; Abu-Elmagd, K; Miller, C; Quintini, C

    2016-03-01

    The utilization of normothermic machine perfusion (NMP) may be an effective strategy to resuscitate livers from donation after circulatory death (DCD). There is no consensus regarding the efficacy of different perfusates on graft and bile duct viability. The aim of this study was to compare, in an NMP porcine DCD model, the preservation potential of three different perfusates. Twenty porcine livers with 60 min of warm ischemia were separated into four preservation groups: cold storage (CS), NMP with Steen solution (Steen; XVIVO Perfusion Inc., Denver, CO), Steen plus red blood cells (RBCs), or whole blood (WB). All livers were preserved for 10 h and reperfused to simulate transplantation for 24 h. During preservation, the NMP with Steen group presented the highest hepatocellular injury. At reperfusion, the CS group had the lowest bile production and the worst hepatocellular injury compared with all other groups, followed by NMP with Steen; the Steen plus RBC and WB groups presented the best functional and hepatocellular injury outcomes, with WB livers showing lower aspartate aminotransferase release and a trend toward better results for most parameters. Based on our results, a perfusate that contains an oxygen carrier is most effective in a model of NMP porcine DCD livers compared with Steen solution. Specifically, WB-perfused livers showed a trend toward better outcomes compared with Steen plus RBCs. PMID:26663737

  18. Experience with registered mucosal vaccines.

    PubMed

    Dietrich, Guido; Griot-Wenk, Monika; Metcalfe, Ian C; Lang, Alois B; Viret, Jean-François

    2003-01-30

    Most pathogens gain access to their host through mucosal surfaces. It is therefore desirable to develop vaccination strategies that lead to mucosal immune responses. Ideally, a vaccine should be administered mucosally in order to elicit mucosal protection. Several attenuated live viral and bacterial pathogens are registered as oral vaccines for human use, including the oral polio vaccine (Sabin) as well as attenuated strains of Salmonella typhi and Vibrio cholerae. These attenuated bacterial live vaccines-S. typhi Ty21a as well as V. cholerae CVD 103-HgR-are employed as vaccines against typhoid and cholera, respectively. In this manuscript, we review the immune responses that are induced by these vaccines, with a focus on mucosal immunity. PMID:12531339

  19. 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. PMID:21741878

  20. Absolute Cerebral Blood Flow Infarction Threshold for 3-Hour Ischemia Time Determined with CT Perfusion and 18F-FFMZ-PET Imaging in a Porcine Model of Cerebral Ischemia

    PubMed Central

    Cockburn, Neil; Kovacs, Michael

    2016-01-01

    CT Perfusion (CTP) derived cerebral blood flow (CBF) thresholds have been proposed as the optimal parameter for distinguishing the infarct core prior to reperfusion. Previous threshold-derivation studies have been limited by uncertainties introduced by infarct expansion between the acute phase of stroke and follow-up imaging, or DWI lesion reversibility. In this study a model is proposed for determining infarction CBF thresholds at 3hr ischemia time by comparing contemporaneously acquired CTP derived CBF maps to 18F-FFMZ-PET imaging, with the objective of deriving a CBF threshold for infarction after 3 hours of ischemia. Endothelin-1 (ET-1) was injected into the brain of Duroc-Cross pigs (n = 11) through a burr hole in the skull. CTP images were acquired 10 and 30 minutes post ET-1 injection and then every 30 minutes for 150 minutes. 370 MBq of 18F-FFMZ was injected ~120 minutes post ET-1 injection and PET images were acquired for 25 minutes starting ~155–180 minutes post ET-1 injection. CBF maps from each CTP acquisition were co-registered and converted into a median CBF map. The median CBF map was co-registered to blood volume maps for vessel exclusion, an average CT image for grey/white matter segmentation, and 18F-FFMZ-PET images for infarct delineation. Logistic regression and ROC analysis were performed on infarcted and non-infarcted pixel CBF values for each animal that developed infarct. Six of the eleven animals developed infarction. The mean CBF value corresponding to the optimal operating point of the ROC curves for the 6 animals was 12.6 ± 2.8 mL·min-1·100g-1 for infarction after 3 hours of ischemia. The porcine ET-1 model of cerebral ischemia is easier to implement then other large animal models of stroke, and performs similarly as long as CBF is monitored using CTP to prevent reperfusion. PMID:27347877

  1. 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.

  2. Reduced gastric acid production in burn shock period and its significance in the prevention and treatment of acute gastric mucosal lesions.

    PubMed

    Zhu, Li; Yang, Zhong-Cheng; Li, Ao; Cheng, De-Chang

    2000-02-01

    AIM:To investigate the changes of gastric acid production and its mechanism in shock period of severe burn in rats.METHODS:A rat model with 30% TBSA full thickness burn injury was employed and the gastric acid production,together with gastric mucosal blood flow (GMBF) and energy charge (EC) were measured serially within 48h postburn.RESULTS:The gastric acid production in the acute shock period was markedly inhibited after severe burn injury.At the 3rd h postburn,the gastric juice volume, total acidity and acid output were already significantly decreased (P < 0.01 =, and reached the lowest point, 0.63mL/L ± 0.20mL/L, 10.81mmol/L ± 2.58mmol/L and 2.23mmol/h ± 0.73mmol/h respectively, at the 12th h postburn. Although restored to some degree 24h after thermal injury, the variables above were still statistically lower, compared with those of control animals at the 48th h postburn. The GMBF and EC were also significantly reduced after severe burns, consistent with the trend of gastric acid production changes.CONCLUSION:Gastric acid production, as well as GMBF and EC was predominantly decreased in the early postburn stage, suggesting that gastric mucosal ischemia and hypoxia with resultant disturbance in energy metabolism, but not gastric acid proper, might be the decisive factor in the pathogenesis of AGML after thermal injury, and that the preventive use of anti-acid drugs during burn shock period was unreasonable in some respects. Therefore, taking effective measures to improve gastric mucosal blood perfusion as early as possible postburn might be more preferable for the AGML prevention and treatment. PMID:11819529

  3. Perfusion and ventilation of isolated canine lungs

    PubMed Central

    Otto, T. J.; Trenkner, M.; Stopczyk, A.; Gawdziński, M.; Chełstowska, B.

    1968-01-01

    In order to evaluate methods of preserving lungs for use in transplantation, experiments on 28 mongrel dogs were carried out. Two methods were tried—first, mechanical respiration of isolated lungs under deep hypothermia, with the vascular bed filled with blood; and, secondly, the perfusion of isolated lungs with the aid of a modified DeWall's apparatus. Allogenic transplantations of lungs preserved in both ways were carried out. Gasometric and histological examinations of preserved lungs, before and after transplantation, were performed. The best results were obtained with perfusion under hypothermic conditions; ventilation without perfusion resulted in failure. Lung transplantation was successful when, after being preserved, the lung remained unchanged. Major discrepancies between the macroscopic and microscopic findings in preserved lungs were observed. An original classification of the changes occurring in preserved lungs is proposed. PMID:4886091

  4. 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

  5. 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

    Carulli, Giovanni; Rocco, Melania; Panichi, Alessia; Chios, Chiara Feira; Ciurli, Ester; Mannucci, Chiara; Sordi, Elisabetta; Caracciolo, Francesco; Papineschi, Federico; Benedetti, Edoardo; Petrini, Mario

    2013-01-25

    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

  6. Towards robust deconvolution of low-dose perfusion CT: sparse perfusion deconvolution using online dictionary learning.

    PubMed

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

    2013-05-01

    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

  7. 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

  8. The effects of perfusion conditions on melphalan distribution in the isolated perfused rat hindlimb bearing a human melanoma xenograft.

    PubMed

    Wu, Z Y; Smithers, B M; Parsons, P G; Roberts, M S

    1997-01-01

    An isolated rat hindlimb perfusion model carrying xenografts of the human melanoma cell line MM96 was used to study the effects of perfusion conditions on melphalan distribution. Krebs-Henseleit buffer and Hartmann's solution containing 4.7% bovine serum albumin (BSA) or 2.8% dextran 40 were used as perfusates. Melphalan concentrations in perfusate, tumour nodules and normal tissues were measured using high-performance liquid chromatography (HPLC). Increasing the perfusion flow rates (from 4 to 8 ml min(-1)) resulted in higher tissue blood flow (determined with 51Cr-labelled microspheres) and melphalan uptake by tumour and normal tissues. The distribution of melphalan within tumour nodules and normal tissues was similar for both Krebs-Henseleit buffer and Hartmann's solution; however, tissue concentrations of melphalan were significantly higher for a perfusate containing 2.8% dextran 40 than for one containing 4.7% BSA. The melphalan concentration in the tumour was one-third of that found in the skin if the perfusate contained 4.7% BSA. In conclusion, this study has shown that a high perfusion flow enhances the delivery of melphalan into implanted tumour nodules and normal tissues, and a perfusate with low melphalan binding (no albumin) is preferred for maximum uptake of drug by the tumour. PMID:9099965

  9. A prospective, randomized study of cryotherapy during administration of high-dose melphalan to decrease the severity and duration of oral mucositis in patients with multiple myeloma undergoing autologous peripheral blood stem cell transplantation.

    PubMed

    Lilleby, K; Garcia, P; Gooley, T; McDonnnell, P; Taber, R; Holmberg, L; Maloney, D G; Press, O W; Bensinger, W

    2006-06-01

    Forty patients with multiple myeloma scheduled to receive melphalan 200 mg/m(2) followed by autologous stem cell transplantation were randomly assigned to receive oral cryotherapy or room temperature normal saline rinses 30 min before and for 6 h after high-dose therapy. Patients were evaluated for the development of mucositis using the National Cancer Institute grading system as well as evaluation of secondary measures such as days of total parenteral nutrition (TPN), narcotic use, hospitalization, weight loss and resumption of oral caloric intake for 28 days after transplant. Patients self-scored their pain, swallowing, drinking, eating, sleeping and taste alterations for 28 days. The primary end point of this trial was the incidence of grades 3-4 mucositis. Compared to the normal saline group, patients using cryotherapy experienced less grade 3-4 mucositis, 14 vs 74%, P=0.0005. Patients receiving cryotherapy also had statistically lower uses of narcotics and TPN, although there were no differences in length of hospitalization or weight loss. Patient-reported pain was significantly lower and activities were significantly better in the cryotherapy group. PMID:16633359

  10. 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

  11. 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).

  12. Radionuclide cerebral perfusion imaging: Normal pattern

    SciTech Connect

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

    1991-12-31

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

  13. Cerebral blood flow in patients with peritoneal dialysis by an easy Z-score imaging system for brain perfusion single-photon emission tomography.

    PubMed

    Isshiki, Rei; Kobayashi, Shuzo; Iwagami, Masao; Tsutumi, Daimu; Mochida, Yasuhiro; Ishioka, Kunihiro; Oka, Machiko; Maesato, Kyoko; Moriya, Hidekazu; Ohtake, Takayasu; Hidaka, Sumi

    2014-06-01

    Cognitive impairment has long been recognized as a complication of chronic kidney disease. However, there is little information available regarding regional cerebral blood flow (rCBF) in patients with peritoneal dialysis (PD). Therefore, we evaluated rCBF using brain single photon emission computed tomography (SPECT). We conducted a cross-sectional study in our hospital. Eighteen consecutive PD patients who could visit the hospital by themselves without any history of stroke were examined by Technetium-99 m-labeled ethylcrysteinate dimer brain SPECT. An easy Z-score imaging system (eZIS) was used to compare rCBF in PD patients with those in age-matched healthy controls. We also evaluated cognitive dysfunction with the mini-mental state examination (MMSE) questionnaire. Only one patient showed an MMSE score of 18 points, and the remaining 14 patients were considered as normal (MMSE ≥ 27), and three patients were considered to have mild cognitive impairment (24 ≤ MMSE ≤ 26). In all patients, rCBF in the posterior cingulated gyri, precunei, and parietal cortices was significantly decreased. The ratio of the reduction of rCBF in each region relative to that of rCBF across the whole brain correlated positively with the PD duration (r = 0.559; P < 0.05). The serum β2-microglobulin level was significantly higher in patients who had a higher ratio of rCBF reduction compared with those with lower ratios. In conclusion, all PD patients in the present study had decreased rCBF irrespective of MMSE scores. PMID:24965295

  14. Gastric mucosal injury in systemic lupus erythematosus patients receiving pulse methylprednisolone therapy

    PubMed Central

    Luo, Jiing-Chyuan; Chang, Full-Young; Chen, Tseng-Shing; Ng, Yee-Yung; Lin, Han-Chieh; Lu, Ching-Liang; Chen, Chih-Yen; Lin, Hsiao-Yi; Lee, Shou-Dong

    2009-01-01

    AIMS Whether glucocorticoids induce gastric mucosal injury remains uncertain. We investigated whether very high-dose steroids caused gastric mucosal injury in systemic lupus erythematous (SLE) patients and evaluated the possible risk factors for mucosal injury. METHODS In this prospective paired study, 67 SLE patients who had received pulse methylprednisolone therapy were enrolled. Each patient underwent endoscopic examination and tissue and blood sampling before and after pulse steroid therapy. Mucosal injury was diagnosed if the follow-up injury scale was higher than the initial scale. Examined parameters included Helicobacter pylori infection, cyclooxygenase (COX)-1 and COX-2 activity, and current nonsteroidal anti-inflammatory drug (NSAID) usage including aspirin. RESULTS Eleven (16.4%) of 67 cases who developed gastric mucosal injury after pulse therapy had significantly higher rates of peptic ulcer history, NSAID/aspirin use, lower gastric thromboxane B2 and prostaglandin E2 levels when compared with cases without gastric mucosal injury (P < 0.05). Infection by H. pylori was not a risk factor for gastric mucosal injury. Multivariate logistic regression analysis showed that NSAID/aspirin use was the only risk factor for gastric mucosal injury in these patients (odds ratio 26.99, 95% confidence interval 4.91, 148.57, P < 0.0001). Pulse steroid therapy alone did not induce gastric mucosal injury in fifty SLE patients without taking any NSAID/aspirin. CONCLUSIONS Use of NSAIDs/aspirin, but not H. pylori infection, increases gastric mucosal injury in SLE patients receiving pulse methylprednisolone therapy. Very high-dose steroids de novo seem not to induce gastric mucosal injury in these patients. A larger case-controlled study enrolling a heterogeneous population is needed to clarify the role of glucocorticoids in gastric mucosal injury. PMID:19694746

  15. Cheek mucosa territories perfused by perforators from the facial artery.

    PubMed

    Coronel-Banda, M E; Serra-Renom, J M; Lorente, M; Larrea-Terán, W P

    2015-01-01

    The cutaneous areas perfused by the cutaneous perforators of the facial artery have been well defined. However, the oral mucosal areas perfused by perforators of the facial artery have not been described. We studied 20 hemifaces from 10 cadavers. Perforators between the branching off sites of the labial arteries larger than 0.5 mm were selected and their diameters were measured; the distance between their exit point over the facial artery and the branching-off point from the superior labial artery was also measured. The selected perforators were injected with 1 ml of diluted ink. Both labial arteries were ligated to limit the study to the mucosal perforators from the facial artery. Seventy-four perforators from 20 hemifaces were studied; the mean diameter was 0.58 mm and the mean number per artery was 3.7. The total stained area, a triangle-shaped zone on the cheek, was determined. The more constant perforators larger than 0.5 mm were localized next to the branching-off site of the superior labial artery. With this information, flaps based on the mucosal perforators from the facial artery could be designed. PMID:25218801

  16. 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.

  17. 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

  18. 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.

  19. Perfusion CT imaging of treatment response in oncology.

    PubMed

    Prezzi, Davide; Khan, Aisha; Goh, Vicky

    2015-12-01

    Perfusion CT was first described in the 1970s but has become accepted as a clinical technique in recent years. In oncological practice Perfusion CT allows the downstream effects of therapies on the tumour vasculature to be monitored. From the dynamic changes in tumour and vascular enhancement following intravenous iodinated contrast agent administration, qualitative and quantitative parameters may be derived that reflect tumour perfusion, blood volume, and microcirculatory changes with treatment. This review outlines the mechanisms of action of available therapies and state-of-the-art imaging practice. PMID:25864440

  20. 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. PMID:27198192

  1. Perfusion of nonventilated lung: failure of hypoxic vasoconstriction

    SciTech Connect

    Sostman, H.D.; Neumann, R.D.; Gottschalk, A.; Greenspan, R.H.

    1983-07-01

    Alveolar hypoxia is a well established cause of regional vasoconstriction such that nonventilated segments are not perfused. The paradoxical situation of retained perfusion of nonventilated lung has seldom been discussed. Three clinical examples are illustrated. In each case coexistent chronic obstructive lung disease may have contributed to this unexpected finding by reducing pulmonary vascular capacity such that blood flow diversion from hypoxic segments was not possible.

  2. 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

  3. EFFECT ON PERFUSION VALUES OF SAMPLING INTERVAL OF CT PERFUSION ACQUISITIONS IN NEUROENDOCRINE LIVER METASTASES AND NORMAL LIVER

    PubMed Central

    Ng, Chaan S.; Hobbs, Brian P.; Wei, Wei; Anderson, Ella F.; Herron, Delise H.; Yao, James C.; Chandler, Adam G.

    2014-01-01

    Objective To assess the effects of sampling interval (SI) of CT perfusion acquisitions on CT perfusion values in normal liver and liver metastases from neuroendocrine tumors. Methods CT perfusion in 16 patients with neuroendocrine liver metastases were analyzed by distributed parameter modeling to yield tissue blood flow, blood volume, mean transit time, permeability, and hepatic arterial fraction, for tumor and normal liver. CT perfusion values for the reference sampling interval of 0.5s (SI0.5) were compared with those of SI datasets of 1s, 2s, 3s and 4s, using mixed-effects model analyses. Results Increases in SI beyond 1s were associated with significant and increasing departures of CT perfusion parameters from reference values at SI0.5 (p≤0.0009). CT perfusion values deviated from reference with increasing uncertainty with increasing SIs. Findings for normal liver were concordant. Conclusion Increasing SIs beyond 1s yield significantly different CT perfusion parameter values compared to reference values at SI0.5. PMID:25626401

  4. 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

    2016-01-01

    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

  5. 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

  6. 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.

  7. Ex vivo lung perfusion.

    PubMed

    Reeb, Jeremie; Cypel, Marcelo

    2016-03-01

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

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

    SciTech Connect

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

    1984-01-01

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

  9. Jejunal Perfusion of Simple and Conjugated Folates in Tropical Sprue

    PubMed Central

    Corcino, José J.; Reisenauer, Ann M.; Halsted, Charles H.

    1976-01-01

    Absorption of labeled simple 3′,5′,9′-3H pteroylmonoglutamate, ([3H]PG-1) and conjugated pteroyl-μ[14C]glutamyl-γ-hexaglutamate, ([14C]PG-7) folates was assessed in six patients with tropical sprue, before and after 6 mo of treatment, utilizing jejunal perfusion and urinary recovery techniques. Degradation products of [14C]PG-7 which were produced during perfusion were identified by DEAE-cellulose column chromatography. Jejunal mucosal activities of folate conjugase, lactase, sucrase, and maltase were measured in every patient. Malabsorption of both [3H]PG-1 and [14C]PG-7 was found in every untreated patient, with significant improvement after therapy. The urinary excretion of 3H and 14C paralleled the luminal disappearance of both isotopes. The chromatographic patterns of intraluminal degradation products of [14C]PG-7 obtained during perfusion did not differ from those previously found in normal subjects and were similar in studies performed before and after treatment. The activity of folate conjugase was increased in the mucosa of the untreated patients when compared to the post-treatment levels while the activities of mucosal lactase, sucrase, and maltase were originally low and increased significantly after therapy. These observations suggest that folate conjugase originates at a different mucosal locus than the brush border disaccharidases, and are consistent with previous evidence that folate conjugase is an intracellular enzyme. The present studies have demonstrated unequivocal malabsorption of both simple and conjugated folates in tropical sprue. In tropical sprue, folate malabsorption is the reflection of impaired folate transport and not of impaired hydrolysis. PMID:16695965

  10. Immediate effect of benzalkonium chloride in decongestant nasal spray on the human nasal mucosal temperature.

    PubMed

    Lindemann, J; Leiacker, R; Wiesmiller, K; Rettinger, G; Keck, T

    2004-08-01

    Benzalkonium chloride is a preservative commonly used in nasal decongestant sprays. It has been suggested that benzalkonium chloride may be harmful to the nasal mucosa. Decongestion with the vasoconstrictor xylometazoline containing benzalkonium chloride has been shown to cause a significant reduction of the nasal mucosal temperature. The purpose of the present study was to determine the short-term influence of xylometazoline nasal spray with and without benzalkonium chloride on the nasal mucosal temperature. Healthy volunteers (30) were included in the study. Fifteen volunteers received xylometazoline nasal spray (1.0 mg/mL) containing benzalkonium chloride (0.1 mg/mL) and 15 age-matched subjects, received xylometazoline nasal spray without benzalkonium chloride. Using a miniaturized thermocouple the septal mucosal temperature was continuously measured at defined intranasal detection sites before and after application of the nasal spray. The mucosal temperature values did not significantly differ between the group receiving xylometazoline containing benzalkonium chloride and the group receiving xylometazoline spray without benzalkonium chloride before and after decongestion (P > 0.05). In both study groups septal mucosal temperatures significantly decreased after decongestion (P < 0.05) because of a reduction of the nasal mucosal blood flow following vasoconstriction. This study indicates that benzalkonium chloride itself does not seem to influence nasal blood flow and nasal mucosal temperature in topical nasal decongestants. PMID:15270822

  11. Seatbelt syndrome with gastric mucosal breaks and intra-gastric wall air leakage.

    PubMed

    Mori, Hirohito; Tsushimi, Takaaki; Kobara, Hideki; Nishiyama, Noriko; Fujihara, Shintaro; Matsunaga, Tae; Ayaki, Maki; Chiyo, Taiga; Masaki, Tsutomu

    2015-01-01

    As numerous reports were published regarding the so-called seatbelt syndrome involved in car crashes, most of them were mentioned about small intestine, duodenum and colon perforations and solid organ bleeding. No reports have been published regarding multiple gastric mucosal tears with intra-gastric wall air leakage with massive bleeding. A 65-year-old woman was admitted after a motor vehicle crash. She vomited massive fresh blood. Gastric mucosal breaks, approximately 5 cm in length, were observed. Computed tomography imaging revealed multiple gastric mucosal breaks. We report a rare case wherein a traffic accident caused a serious condition associated with massive digestive bleeding. PMID:26466695

  12. C-Reactive Protein Levels and Radiation-Induced Mucositis in Patients With Head-and-Neck Cancer

    SciTech Connect

    Ki, Yongkan; Kim, Wontaek Nam, Jiho; Kim, Donghyun; Park, Dahl; Kim, Dongwon

    2009-10-01

    Purpose: To evaluate the relationship between C-reactive protein (CRP) levels or the erythrocyte sedimentation rate (ESR) and the grade of acute radiation-induced mucositis in patients with head-and-neck cancer. Methods and Materials: This study was performed in 40 patients who received intensity-modulated radiation therapy as a radical treatment of primary laryngo-pharyngeal cancer. Serum CRP level and ESR were initially checked on the day of radiotherapy simulation and were measured every week during the irradiation schedule and two times biweekly after radiotherapy. Mucosal reactions were evaluated by radiation oncologists on days of blood sampling. Results: The distribution of the most severe mucositis was Grade I mucositis in 10% of the patients, Grade II in 60% of the patients and Grade III in 30% of the patients. Statistical analysis indicated a significant rise in the CRP level (p < 0.001) according to radiation fraction number and grade of mucositis. A change of the mean CRP level was correlated with progression of mean grade of mucositis according to fraction number. The ESR did not show any statistically significant relationship with radiotherapy fraction number and grade of acute mucositis. Conclusions: There was a significant correlation between the presence of acute mucositis and CRP level in this study. The CRP level could be conveniently determined along with evaluation of mucosal reactions during or after radiotherapy to provide further information on radiation-induced mucositis.

  13. Intestinal mucosal tolerance and impact of gut microbiota to mucosal tolerance

    PubMed Central

    Chistiakov, Dimitry A.; Bobryshev, Yuri V.; Kozarov, Emil; Sobenin, Igor A.; Orekhov, Alexander N.

    2015-01-01

    The mucosal barriers are very sensitive to pathogenic infection, thereby assuming the capacity of the mucosal immune system to induce protective immunity to harmful antigens and tolerance against harmless substances. This review provides current information about mechanisms of induction of mucosal tolerance and about impact of gut microbiota to mucosal tolerance. PMID:25628617

  14. Development of an Ex Vivo, Beating Heart Model for CT Myocardial Perfusion

    PubMed Central

    Pelgrim, Gert Jan; Das, Marco; Haberland, Ulrike; Slump, Cees; Handayani, Astri; van Tuijl, Sjoerd; Stijnen, Marco; Klotz, Ernst; Oudkerk, Matthijs; Wildberger, Joachim E.; Vliegenthart, Rozemarijn

    2015-01-01

    Objective. To test the feasibility of a CT-compatible, ex vivo, perfused porcine heart model for myocardial perfusion CT imaging. Methods. One porcine heart was perfused according to Langendorff. Dynamic perfusion scanning was performed with a second-generation dual source CT scanner. Circulatory parameters like blood flow, aortic pressure, and heart rate were monitored throughout the experiment. Stenosis was induced in the circumflex artery, controlled by a fractional flow reserve (FFR) pressure wire. CT-derived myocardial perfusion parameters were analysed at FFR of 1 to 0.10/0.0. Results. CT images did not show major artefacts due to interference of the model setup. The pacemaker-induced heart rhythm was generally stable at 70 beats per minute. During most of the experiment, blood flow was 0.9–1.0 L/min, and arterial pressure varied between 80 and 95 mm/Hg. Blood flow decreased and arterial pressure increased by approximately 10% after inducing a stenosis with FFR ≤ 0.50. Dynamic perfusion scanning was possible across the range of stenosis grades. Perfusion parameters of circumflex-perfused myocardial segments were affected at increasing stenosis grades. Conclusion. An adapted Langendorff porcine heart model is feasible in a CT environment. This model provides control over physiological parameters and may allow in-depth validation of quantitative CT perfusion techniques. PMID:26185756

  15. 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

  16. 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.

  17. Parallel perfusion imaging processing using GPGPU

    PubMed Central

    Zhu, Fan; Gonzalez, David Rodriguez; Carpenter, Trevor; Atkinson, Malcolm; Wardlaw, Joanna

    2012-01-01

    Background and purpose The objective of brain perfusion quantification is to generate parametric maps of relevant hemodynamic quantities such as cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) that can be used in diagnosis of acute stroke. These calculations involve deconvolution operations that can be very computationally expensive when using local Arterial Input Functions (AIF). As time is vitally important in the case of acute stroke, reducing the analysis time will reduce the number of brain cells damaged and increase the potential for recovery. Methods GPUs originated as graphics generation dedicated co-processors, but modern GPUs have evolved to become a more general processor capable of executing scientific computations. It provides a highly parallel computing environment due to its large number of computing cores and constitutes an affordable high performance computing method. In this paper, we will present the implementation of a deconvolution algorithm for brain perfusion quantification on GPGPU (General Purpose Graphics Processor Units) using the CUDA programming model. We present the serial and parallel implementations of such algorithms and the evaluation of the performance gains using GPUs. Results Our method has gained a 5.56 and 3.75 speedup for CT and MR images respectively. Conclusions It seems that using GPGPU is a desirable approach in perfusion imaging analysis, which does not harm the quality of cerebral hemodynamic maps but delivers results faster than the traditional computation. PMID:22824549

  18. Spatial distribution of ventilation and perfusion: mechanisms and regulation.

    PubMed

    Glenny, Robb W; Robertson, H Thomas

    2011-01-01

    With increasing spatial resolution of regional ventilation and perfusion, it has become more apparent that ventilation and blood flow are quite heterogeneous in the lung. A number of mechanisms contribute to this regional variability, including hydrostatic gradients, pleural pressure gradients, lung compressibility, and the geometry of the airway and vascular trees. Despite this marked heterogeneity in both ventilation and perfusion, efficient gas exchange is possible through the close regional matching of the two. Passive mechanisms, such as the shared effect of gravity and the matched branching of vascular and airway trees, create efficient gas exchange through the strong correlation between ventilation and perfusion. Active mechanisms that match local ventilation and perfusion play little if no role in the normal healthy lung but are important under pathologic conditions. PMID:23737178

  19. Tissue distribution of exogenous amino acids during transport across the vascularly perfused anuran small intestine.

    PubMed Central

    Cheeseman, C I; King, I; Smith, M W

    1983-01-01

    Microdensitometric analysis of autoradiographs has been used to measure the distribution and intracellular concentration of L-leucine and L-lysine during transport across the vascularly perfused small intestine of Rana pipiens. L-leucine was not accumulated in the mucosal epithelium to a concentration higher than that in the lumen under steady-state conditions, whereas L-lysine was concentrated on average three- to four-fold. 2. At the end of 30 min loading, the majority of both amino acids were found in the mucosal epithelium and the villous core, although significant amounts were also present in the muscle. Lysine showed a gradient of accumulation within the mucosal epithelium along the length of the villous folds, the highest concentrations being achieved in the cells near the tip. Leucine showed no such gradient under steady-state conditions. 3. Superfusion of the mucosal surface of the tissue with leucine for only 3 min did reveal a gradient for uptake into the mucosal epithelium, although it was still not as steep as that seen for lysine. 4. The presence of leucine in the vascular bed while lysine was perfused through the lumen significantly lowered the concentration of lysine in the mucosal epithelium and villous core and eliminated the concentration gradient in the mucosal epithelium seen along the villous fold. 5. When leucine was perfused on its own through the vascular bed, the uptake into the muscle was greatly increased compared to when the amino acid was presented from the lumen. At the same time, the uptake into the mucosal epithelium was reduced by 45%. 6. Analysis of the tissue content of leucine after loading for 30 min from the lumen and then washing out the amino acid for 15 min showed that the mucosal epithelium, villous core and muscle had contributed 74%, 17% and 9% respectively to the total amino acid lost from the tissue. 7. These results are discussed with regard to the significance of the exit mechanisms for these amino acids and the

  20. Regional Myocardial Perfusion Rates in Patients with Coronary Artery Disease

    PubMed Central

    Cannon, Paul J.; Dell, Ralph B.; Dwyer, Edward M.

    1972-01-01

    Regional myocardial perfusion rates were estimated from the myocardial washout of 133Xenon in 24 patients with heart disease whose coronary arteriograms were abnormal and 17 similar subjects whose coronary arteriograms were judged to be normal. Disappearance rates of 133Xe from multiple areas of the heart were monitored externally with a multiple-crystal scintillation camera after the isotope had been injected into a coronary artery and local myocardial perfusion rates were calculated by the Kety formula. The mean myocardial perfusion rates in the left ventricle exceeded those in the right ventricle or atrial regions in subjects without demonstrable coronary artery disease. In this group there was a significant lack of homogeneity of local perfusion rates in left ventricular myocardium; the mean coefficient of variation of left ventricular local perfusion rates was 15.8%. In the patients with radiographically demonstrable coronary artery disease, a variety of myocardial perfusion patterns were observed. Local capillary blood flow rates were depressed throughout the myocardium of patients with diffuse coronary disease but were subnormal only in discrete myocardial regions of others with localized occlusive disease. Local myocardial perfusion rates were similar to those found in the group with normal coronary arteriograms in patients with slight degrees of coronary disease and in those areas of myocardium distal to marked coronary constrictions or occlusions which were well supplied by collateral vessels. In subjects with right coronary disease, the mean right ventricular perfusion rates were significantly subnormal; in seven subjects of this group perfusion of the inferior left ventricle by a dominant right coronary artery was absent or depressed. The average mean left ventricular perfusion rate of 12 subjects with significant disease of two or more branches of the left coronary artery was significantly lower than that of the group with normal left coronary

  1. Metabolism, sperm and fluid production of the isolated perfused testis of the sheep and goat

    PubMed Central

    Linzell, J. L.; Setchell, B. P.

    1969-01-01

    1. A total of nineteen ram and three goat testes have been perfused in isolation at 34-35° C for 3½-9 hr with heparinized blood and an added 5-HT antagonist (bromolysergic acid diethylamide) and their function compared with that of the normal ram testes in vivo. 2. The metabolism of the perfused testes and the testes in vivo was similar but blood flow through the perfused testes was two to three times normal. 3. Vasoconstriction was produced by adrenaline and noradrenaline (10-20 μg I.A.) and by electrical stimulation of nerves in the spermatic cord or of the lumbar sympathetic chain; these responses were abolished or reduced by phenoxybenzamine. 4. Flow of fluid from the rete testis continued only if ischaemia was reduced to a minimum and glucose concentration in the blood perfusing the testis was kept above about 25 mg/100 ml.; the fluid secreted during perfusion was of normal composition. 5. The perfused testis showed no evidence of autoregulation and the flow of fluid was not affected by changes in perfusion pressure. 6. When the temperature of three testes was raised to 40° C for 2 hr, metabolism increased but blood flow was unaltered; the flow of fluid and the concentration of spermatozoa decreased during heating. 7. The testes perfused at normal scrotal temperatures (34-35° C) were histologically normal but some abnormalities were observed in the heated testes. ImagesFig. 3Fig. 4 PMID:5773547

  2. 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

  3. 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

  4. 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

  5. Dendritic cell-targeting DNA-based mucosal adjuvants for the development of mucosal vaccines

    PubMed Central

    Kataoka, Kosuke; Fujihashi, Kohtaro

    2009-01-01

    In order to establish effective mucosal immunity against various mucosal pathogens, vaccines must be delivered via the mucosal route and contain effective adjuvant(s). Since mucosal adjuvants can simply mix with the antigen, it is relatively easy to adapt them for different types of vaccine development. Even in simple admixture vaccines, the adjuvant itself must be prepared without any complications. Thus, CpG oligodeoxynucleotides or plasmids encoding certain cDNA(s) would be potent mucosal adjuvant candidates when compared with other substances that can be used as mucosal adjuvants. The strategy of a DNA-based mucosal adjuvant facilitates the targeting of mucosal dendritic cells, and thus is an effective and safe approach. It would also provide great flexibility for the development of effective vaccines for various mucosal pathogens. PMID:19722892

  6. 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.

  7. Mucosal immunologic responses in cholera patients in Bangladesh.

    PubMed

    Uddin, Taher; Harris, Jason B; Bhuiyan, Taufiqur Rahman; Shirin, Tahmina; Uddin, Muhammad Ikhtear; Khan, Ashraful Islam; Chowdhury, Fahima; LaRocque, Regina C; Alam, Nur Haque; Ryan, Edward T; Calderwood, Stephen B; Qadri, Firdausi

    2011-03-01

    Vibrio cholerae O1 causes dehydrating diarrhea with a high mortality rate if untreated. The infection also elicits long-term protective immunity. Since V. cholerae is noninvasive, mucosal immunity is likely important for protection. In this study, we compared humoral immune responses in the duodenal mucosa and blood of cholera patients at different time points after the onset of disease and compared them with those of healthy controls (HCs). Immune responses to lipopolysaccharide (LPS) and the recombinant cholera toxin B subunit (rCTB) were assessed by enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot (ELISPOT) assay. Significant increases in V. cholerae LPS-specific IgA and IgG antibody levels were seen in duodenal extracts on day 30, but the levels decreased to baseline by day 180; plasma V. cholerae LPS-specific IgA levels remained elevated longer. Levels of mucosal CTB antibodies also peaked on day 30, but the increase reached statistical significance only for IgG. A significant correlation was found between the CTB antibody-secreting cell (ASC) response in the circulatory system on day 7 and subsequent CTB-specific IgA levels in duodenal extracts on day 30 and the numbers of CTB-specific IgA ASCs in duodenal tissues on day 180. The proportion (0.07%) of mucosal V. cholerae LPS IgA ASCs peaked on day 30 and remained elevated through day 180 compared to that of HCs (P = 0.03). These results suggest that protective immunity against V. cholerae is not likely mediated by the constitutive secretion of antibodies at the mucosal surface; our results are consistent with those of other studies that suggest instead that anamnestic immune responses of mucosal lymphocytes may play a major role in protection against cholera. PMID:21248157

  8. 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

  9. 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

  10. 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

  11. 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 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

  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. Renal perfusion scintiscan

    MedlinePlus

    ... to take a blood pressure medicine called an ACE inhibitor. The drug may be taken by mouth, or ... the test. If you are currently taking an ACE inhibitor for high blood pressure , you may be asked ...

  14. Parametric perfusion imaging based on low-cost ultrasound platform.

    PubMed

    Gu, Xiaolin; Zhong, Hui; Wan, Mingxi; Hu, Xiaowen; Lv, Dan; Shen, Liang; Zhang, Xiaomei

    2010-01-01

    In this study, we attempted to implement parametric perfusion imaging to quantify blood perfusion based on modified low-cost ultrasound platform. A novel ultrasound contrast-specific imaging method called pulse-inversion harmonic sum-squared-differences (PIHSSD) was proposed for improving the sensitivity for detecting contrast agents and the accuracy of parametric perfusion imaging, which combined pulse-inversion harmonic (PIH) with pulse-inversion sum-squared-differences (PISSD) threshold-based decision. PIHSSD method just involved simple operations including addition and multiplication and was easy to realize. The sequences of contrast images without logarithmic compression were used to acquire time intensity curves (TICs) from numerous equal-sized regions-of-interest (ROI) covering the entire image plane. Parametric perfusion images were obtained based on the parameters extracted from the TICs, including peak value (PV), area under curve (AUC), mean transit time (MTT), peak value time (PVT), peak width (PW) and climbing rate (CR). Flow phantom was used for validation and the results suggested that PIHSSD method provided 9.6 to 20.3 dB higher contrast-to-tissue ratio (CTR) than PIH method. The results of the experiments of rabbit kidney also showed that the CTR of PIHSSD images was higher than that of PIH images, and the parametric perfusion images based on PIHSSD method provided more accurate quantification of blood perfusion compared with those based on PIH and PISSD methods. It demonstrated that the parametric perfusion imaging achieved good performance though implemented on low-cost ultrasound platform. (E-mail: mxwan@mail.xjtu.edu.cn). PMID:19931972

  15. [Pulmonary ventilation/perfusion ratio].

    PubMed

    Guenard, H

    1987-01-01

    The ratios of ventilatory (V) and perfusion (Q) flow rates in the lung are to a large extent responsible for the efficiency of gas exchange. In a simplified monocompartmental model of the lung, the arterial partial pressure of a given gas (Pa) is a function of several factors: the solubility of this gas in blood, its venous and inspired partial pressures and the V/Q ratio. In a multicompartemental model, the mean arterial partial pressure of the gas is a function of the individual values of Pa in each compartment as well as the distribution of V/Q ratios in the lung and the relationship between the concentration and the partial pressure of the gas. The heterogeneity of the distribution of V/Q results from those of both V and Q. Two factors are mainly responsible for this heterogeneity: the gravity and the morphometric characteristics of bronchi and vessels. V/Q ratios are partially controlled at least in low V/Q compartments since hypoxia in these compartments leads to pulmonary arteriolar vasoconstriction. However lungs V/Q ratios range from 0.1 to 10 with a mode around 1. Age, muscular exercise, posture, accelerations, anesthesia, O2 breathing, pulmonary pathology are factors which may alter the distribution of V/Q ratios. PMID:3332289

  16. Voice Disorders in Mucosal Leishmaniasis

    PubMed Central

    Ruas, Ana Cristina Nunes; Lucena, Márcia Mendonça; da Costa, Ananda Dutra; Vieira, Jéssica Rafael; de Araújo-Melo, Maria Helena; Terceiro, Benivaldo Ramos Ferreira; de Sousa Torraca, Tania Salgado; de Oliveira Schubach, Armando; Valete-Rosalino, Claudia Maria

    2014-01-01

    Introduction Leishmaniasis is considered as one of the six most important infectious diseases because of its high detection coefficient and ability to produce deformities. In most cases, mucosal leishmaniasis (ML) occurs as a consequence of cutaneous leishmaniasis. If left untreated, mucosal lesions can leave sequelae, interfering in the swallowing, breathing, voice and speech processes and requiring rehabilitation. Objective To describe the anatomical characteristics and voice quality of ML patients. Materials and Methods A descriptive transversal study was conducted in a cohort of ML patients treated at the Laboratory for Leishmaniasis Surveillance of the Evandro Chagas National Institute of Infectious Diseases - Fiocruz, between 2010 and 2013. The patients were submitted to otorhinolaryngologic clinical examination by endoscopy of the upper airways and digestive tract and to speech-language assessment through directed anamnesis, auditory perception, phonation times and vocal acoustic analysis. The variables of interest were epidemiologic (sex and age) and clinic (lesion location, associated symptoms and voice quality. Results 26 patients under ML treatment and monitored by speech therapists were studied. 21 (81%) were male and five (19%) female, with ages ranging from 15 to 78 years (54.5+15.0 years). The lesions were distributed in the following structures 88.5% nasal, 38.5% oral, 34.6% pharyngeal and 19.2% laryngeal, with some patients presenting lesions in more than one anatomic site. The main complaint was nasal obstruction (73.1%), followed by dysphonia (38.5%), odynophagia (30.8%) and dysphagia (26.9%). 23 patients (84.6%) presented voice quality perturbations. Dysphonia was significantly associated to lesions in the larynx, pharynx and oral cavity. Conclusion We observed that vocal quality perturbations are frequent in patients with mucosal leishmaniasis, even without laryngeal lesions; they are probably associated to disorders of some resonance

  17. Ocular Blood Flow Autoregulation Mechanisms and Methods

    PubMed Central

    Luo, Xue; Shen, Yu-meng; Jiang, Meng-nan; Lou, Xiang-feng; Shen, Yin

    2015-01-01

    The main function of ocular blood flow is to supply sufficient oxygen and nutrients to the eye. Local blood vessels resistance regulates overall blood distribution to the eye and can vary rapidly over time depending on ocular need. Under normal conditions, the relation between blood flow and perfusion pressure in the eye is autoregulated. Basically, autoregulation is a capacity to maintain a relatively constant level of blood flow in the presence of changes in ocular perfusion pressure and varied metabolic demand. In addition, ocular blood flow dysregulation has been demonstrated as an independent risk factor to many ocular diseases. For instance, ocular perfusion pressure plays key role in the progression of retinopathy such as glaucoma and diabetic retinopathy. In this review, different direct and indirect techniques to measure ocular blood flow and the effect of myogenic and neurogenic mechanisms on ocular blood flow are discussed. Moreover, ocular blood flow regulation in ocular disease will be described. PMID:26576295

  18. Static and dynamic assessment of myocardial perfusion by computed tomography.

    PubMed

    Danad, Ibrahim; Szymonifka, Jackie; Schulman-Marcus, Joshua; Min, James K

    2016-08-01

    Recent developments in computed tomography (CT) technology have fulfilled the prerequisites for the clinical application of myocardial CT perfusion (CTP) imaging. The evaluation of myocardial perfusion by CT can be achieved by static or dynamic scan acquisitions. Although both approaches have proved clinically feasible, substantial barriers need to be overcome before its routine clinical application. The current review provides an outline of the current status of CTP imaging and also focuses on disparities between static and dynamic CTPs for the evaluation of myocardial blood flow. PMID:27013250

  19. Vascular Tissue Engineering: Building Perfusable Vasculature for Implantation

    PubMed Central

    Gui, Liqiong; Niklason, Laura E.

    2014-01-01

    Tissue and organ replacement is required when there are no alternative therapies available. Although vascular tissue engineering was originally developed to meet the clinical demands of small-diameter vascular conduits as bypass grafts, it has evolved into a highly advanced field where perfusable vasculatures are generated for implantation. Herein, we review several cutting-edge techniques that have led to implantable human blood vessels in clinical trials, the novel approaches that build complex perfusable microvascular networks in functional tissues, the use of stem cells to generate endothelial cells for vascularization, as well as the challenges in bringing vascular tissue engineering technologies into the clinics. PMID:24533306

  20. Sublingual microvascular perfusion is altered during normobaric and hyperbaric hyperoxia.

    PubMed

    Milstein, Dan M J; Helmers, Renée; Hackmann, Sanne; Belterman, Charly N W; van Hulst, Robert A; de Lange, Jan

    2016-05-01

    Hyperoxia and hyperbaric oxygen therapy can restore oxygen tensions in tissues distressed by ischemic injury and poor vascularization and is believed to also yield angiogenesis and regulate tissue perfusion. The aim of this study was to develop a model in which hyperoxia-driven microvascular changes could be quantified and to test the hypothesis that microcirculatory responses to both normobaric (NB) and hyperbaric (HB) hyperoxic maneuvers are reversible. Sublingual mucosa microcirculation vessel density, proportion of perfused vessels, vessel diameters, microvascular flow index, macrohemodynamic, and blood gas parameters were examined in male rabbits breathing sequential O2/air mixtures of 21%, 55%, 100%, and return to 21% during NB (1.0bar) and HB (2.5bar) conditions. The results indicate that NB hyperoxia (55% and 100%) produced significant decreases in microvascular density and vascular diameters (p<0.01 and p<0.05, respectively) accompanied by significant increases in systolic and mean arterial blood pressure (p<0.05, respectively) with no changes in blood flow indices when compared to NB normoxia. HB normoxia/hyperoxia resulted in significant decreases in microvascular density (p<0.05), a transient rise in systolic blood pressure at 55% (p<0.01), and no changes in blood vessel diameter and blood flow indices when compared to NB hyperoxia. All microcirculation parameters reverted back to normal values upon return to NB normoxia. We conclude that NB/HB hyperoxia-driven changes elicit reversible physiological control of sublingual mucosa blood perfusion in the presence of steady cardiovascular function and that the absence of microvascular vasoconstriction during HB conditions suggests a beneficial mechanism associated with maintaining peak tissue perfusion states. PMID:26851620

  1. Modelling Brain Temperature and Perfusion for Cerebral Cooling

    NASA Astrophysics Data System (ADS)

    Blowers, Stephen; Valluri, Prashant; Marshall, Ian; Andrews, Peter; Harris, Bridget; Thrippleton, Michael

    2015-11-01

    Brain temperature relies heavily on two aspects: i) blood perfusion and porous heat transport through tissue and ii) blood flow and heat transfer through embedded arterial and venous vasculature. Moreover brain temperature cannot be measured directly unless highly invasive surgical procedures are used. A 3D two-phase fluid-porous model for mapping flow and temperature in brain is presented with arterial and venous vessels extracted from MRI scans. Heat generation through metabolism is also included. The model is robust and reveals flow and temperature maps in unprecedented 3D detail. However, the Karmen-Kozeny parameters of the porous (tissue) phase need to be optimised for expected perfusion profiles. In order to optimise the K-K parameters a reduced order two-phase model is developed where 1D vessels are created with a tree generation algorithm embedded inside a 3D porous domain. Results reveal that blood perfusion is a strong function of the porosity distribution in the tissue. We present a qualitative comparison between the simulated perfusion maps and those obtained clinically. We also present results studying the effect of scalp cooling on core brain temperature and preliminary results agree with those observed clinically.

  2. Dynamic CT head phantom for perfusion and angiography studies

    NASA Astrophysics Data System (ADS)

    Russell, K.; Blazeski, A.; Dannecker, K.; Lee, Q. Y.; Holscher, C.; Donahue, C.; van Kampen, W.

    2010-03-01

    Contrast imaging is a compelling enhancement for the portable, flat panel-based brain CT scanner currently under development at Xoran. Due to the relative low temporal resolution of flat panel detectors, enabling tomographic imaging on such platform requires optimizing the imaging and injection protocols. A dynamic CT head phantom was designed to facilitate this task. The Dynamic Perfusion and Angiography Model (PAM), mimics tissue attenuation in CT images, provides physiological timing for angiography and perfusion studies, and moves fluid with properties similar to those of blood. The design consists of an arterial system, which contains bifurcating vessels that feed into perfusion chambers, mimicking blood flow through capillaries and smaller vessels, and a venous system, which is symmetrical to the arterial side and drains the perfusion chambers. The variation of geometry and flow rate in the phantom provides the physiological total time that fluid spends in the head, and the difference in material densities correlates to CT numbers for biological tissues. This paper discusses the design of Dynamic PAM and shows experimental results demonstrating its ability to realistically simulate blood flow. Results of dynamic imaging studies of the phantom are also presented.

  3. Eosinophils in mucosal immune responses

    PubMed Central

    Travers, J; Rothenberg, M E

    2015-01-01

    Eosinophils, multifunctional cells that contribute to both innate and adaptive immunity, are involved in the initiation, propagation and resolution of immune responses, including tissue repair. They achieve this multifunctionality by expression of a diverse set of activation receptors, including those that directly recognize pathogens and opsonized targets, and by their ability to store and release preformed cytotoxic mediators that participate in host defense, to produce a variety of de novo pleotropic mediators and cytokines and to interact directly and indirectly with diverse cell types, including adaptive and innate immunocytes and structural cells. Herein, we review the basic biology of eosinophils and then focus on new emerging concepts about their role in mucosal immune homeostasis, particularly maintenance of intestinal IgA. We review emerging data about their development and regulation and describe new concepts concerning mucosal eosinophilic diseases. We describe recently developed therapeutic strategies to modify eosinophil levels and function and provide collective insight about the beneficial and detrimental functions of these enigmatic cells. PMID:25807184

  4. Diagnosing acute lacunar infarction using CT perfusion.

    PubMed

    Cao, Wenjie; Yassi, Nawaf; Sharma, Gagan; Yan, Bernard; Desmond, Patricia M; Davis, Stephen M; Campbell, Bruce C V

    2016-07-01

    The value of CT perfusion (CTP) in detecting acute lacunar infarcts (LACI) has not been well established. We tested the sensitivity of CTP for LACI. CTP maps of consecutive stroke patients from 2009-2013 were examined. MRI diffusion imaging was used to identify those with LACI. Two stroke neurologists independently evaluated the CTP maps for evidence of a perfusion lesion in a deep perforating artery territory. Cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT) and time to maximum (Tmax) maps were first examined in isolation and then in combination. Inter-observer agreement was measured using Cohen's κ. The lesions identified were later confirmed against the diffusion MRI reference and the sensitivity and specificity of CTP maps calculated. A total of 63 patient scans were analysed. There were 32 patients with MRI-confirmed LACI within the coverage of CTP; 18 in the striatum, 10 thalamic, and four in the corona radiata. Another 31 patients had normal MRI. Inter-rater agreement was good (κ=0.83). Sensitivity (blinded consensus) was highest for MTT (56.2%) compared to Tmax (25%, p<0.001), CBV (9.3%, p=0.021) and CBF (43.7%, p<0.001). MTT maps enable detection of a significant proportion of LACI using CTP. PMID:26899357

  5. Blue Laser Light Increases Perfusion of a Skin Flap Via Release of Nitric Oxide from Hemoglobin

    PubMed Central

    Mittermayr, Rainer; Osipov, Anatoly; Piskernik, Christina; Haindl, Susanne; Dungel, Peter; Weber, Carina; Vladimirov, Yuri A; Redl, Heinz; Kozlov, Andrey V

    2007-01-01

    It has recently been shown that nitrosyl complexes of hemoglobin (NO-Hb) are sensitive to low-level blue laser irradiation, suggesting that laser irradiation can facilitate the release of biologically active nitric oxide (NO), which can affect tissue perfusion. The aim of this study was to evaluate the therapeutic value of blue laser irradiation for local tissue perfusion after surgical intervention. Blood was withdrawn from a rat, exposed to NO and infused back to the same rat or used for in vitro experiments. In vitro, an increase of NO-Hb levels (electron paramagnetic resonance spectroscopy) up to 15 μM in rat blood did not result in the release of detectable amounts of NO (NO selective electrode). Blue laser irradiation of NO-Hb in blood caused decomposition of NO-Hb complexes and release of free NO. Systemic infusion of NO-Hb in rats affected neither systemic circulation (mean arterial pressure) nor local tissue perfusion (Doppler blood flow imaging system). In contrast, a clear enhancement of local tissue perfusion was observed in epigastric flap when elevated NO-Hb levels in blood were combined with local He-Cd laser irradiation focused on the left epigastric artery. The enhancement of regional tissue perfusion was not accompanied by any detectable changes in systemic circulation. This study demonstrates that blue laser irradiation improves local tissue perfusion in a controlled manner stimulating NO release from NO-Hb complexes. PMID:17515954

  6. Measuring perfusion with light (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Jansen, Sanne M. A.; de Bruin, Daniel M.; Faber, Dirk J.; van Leeuwen, Ton G.

    2016-03-01

    There is no gold standard test for perfusion evaluation in surgery. Optical Imaging techniques are able to image tissue at high resolution and in real-time. Laser Speckle Contrast Imaging, Optical Coherence Tomography, Sidestream Darkfield and Incident Darkfield all use the interaction of light with tissue to create an image. To test their feasibility and explore validity in a controlled setting, we created a phantom with the optical properties of tissue and microvascular channels of 30-400 micrometer. With a Hamilton Syringe Pump we mimicked blood flow velocities of 0-20 mm/sec. Images of all different modalities at different blood flow velocities were compared in terms of imaging depth, resoluation and hemodynamic parameters.

  7. Whole ovine ovaries as a model for human: perfusion with cryoprotectants in vivo and in vitro.

    PubMed

    Isachenko, Vladimir; Rahimi, Gohar; Dattena, Maria; Mallmann, Peter; Baikoshkarova, Saltanat; Kellerwessel, Elisabeth; Otarbaev, Marat; Shalakhmetova, Tamara; Isachenko, Evgenia

    2014-01-01

    These experiments were performed to test the perfusion of ovine as a model for human ovaries by cryoprotectants in vivo at high temperature when the permeability of capillaries is high and when blood is insensibly replaced by the solution of cryoprotectants. By our hypothetical supposition, ovaries could be saturated by cryoprotectants before their surgical removal. The objective was to examine the effectiveness of perfusion of ovine ovaries with vascular pedicle in vivo and in vitro. Arteria ovarica was cannuled and ovaries were perfused by Leibovitz L-15 medium + 100 IU/mL heparin + 5% bovine calf serum + 6% dimethyl sulfoxide + 6% ethylene glycol + 0.15 M sucrose + Indian ink in vivo and in vitro. In the first and second cycle of experiments, ovaries (n = 13 and n = 23) were perfused in vivo and in vitro, respectively, during 60 min with the rate of perfusion 50 mL/h (0.8 mL/min). It was established with in vivo perfusion that only about 10% of ovarian tissues were perfused due to an appearance of multiple anastomoses when the perfusion medium goes from arteria ovarica to arteria uterina without inflow into the ovaries. It was concluded that in vitro perfusion of ovine intact ovaries with vascular pedicle by freezing medium is more effective than this manipulation performed in vivo. PMID:24701576

  8. The Effect of Peritoneal Air Exposure on Intestinal Mucosal Barrier

    PubMed Central

    Bao, Jun; Tan, Shanjun; Yu, Wenkui; Lin, Zhiliang; Dong, Yi; Chen, Qiyi; Shi, Jialiang; Duan, Kaipeng; Bai, Xiaowu; Xu, Lin; Li, Jieshou

    2014-01-01

    Background. Damage of the intestinal mucosa barrier may result in intestinal bacterial and endotoxin translocation, leading to local and systemic inflammation. The present study was designed to investigate whether peritoneal air exposure induces damage of intestinal mucosal barrier. Methods. Sprague-Dawley rats (weighing 210 to 230 g) were randomized into five groups (6/group): a control group, a sham group, and three exposure groups with peritoneal air exposure for 1, 2, and 3 h, respectively. At 24 h after surgery, blood and terminal ileum were sampled. The serum D-lactate levels were determined using an ELISA kit. The intestinal permeability was determined by measuring the intestinal clearance of FITC-dextran (FD4). The histopathological changes in terminal ileum were also assessed. Results. Compared with the controls, peritoneal air exposure caused an increase in both serum D-lactate level and intestinal FD4 clearance, which were proportional to the length of peritoneal air exposure and correlated to Chiu's scores, indices for intestinal mucosal injury. Edema and inflammatory cells were also observed in mucosa and submucosa of ileum in three exposure groups. Conclusions. Peritoneal air exposure could induce damage to the intestinal mucosal barrier, which is proportional to the time length of peritoneal air exposure. PMID:25210511

  9. Ex vivo lung perfusion.

    PubMed

    Machuca, Tiago N; Cypel, Marcelo

    2014-08-01

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

  10. Ex vivo lung perfusion

    PubMed Central

    Machuca, Tiago N.

    2014-01-01

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

  11. Biology and Mucosal Immunity to Myxozoans

    PubMed Central

    Gómez, Daniela; Bartholomew, Jerri; Sunyer, J. Oriol

    2014-01-01

    Myxozoans are among the most abundant parasites in nature. Their life cycles involve two hosts: an invertebrate, usually an annelid, and a vertebrate, usually a fish. They affect fish species in their natural habitats but also constitute a menace for fish aquaculture. Using different strategies they are able to parasitize and cause damage in multiple organs, including mucosal tissues, which they use also as portals of entry. In fish, the main mucosal sites include the intestine, skin and gills. Recently the finding of a specific mucosal immunoglobulin in teleost (IgT), analogous to mammalian IgA, and the capacity of fish to develop a specific mucosal immune response against different pathogens, has highlighted the importance of studying immune responses at mucosal sites. In this review, we describe the major biological characteristics of myxozoan parasites and present the data available regarding immune responses for species that infect mucosal sites. As models for mucosal immunity we review the responses to Enteromyxum spp. and Ceratomyxa shasta, both of which parasitize the intestine. The immune response at the skin and gills is also described, as these mucosal tissues are used by myxozoans as attaching surfaces and portal of entry, and some species also parasitize these sites. Finally, the development of immunoprophylactic strategies is discussed. PMID:23994774

  12. New technique for retrograde cerebral perfusion during arch aneurysm repair.

    PubMed

    Bartoccioni, S; Lanzillo, G; deJong, A A; Fiaschini, P; Martinelli, G; Fedeli, C; Di Lazarro, D; Mercati, U

    1995-09-01

    Many techniques are used to reduce brain damage during surgery for dissecting aneurysms of the ascending aorta and arch. Recently, new techniques of protection were proposed, consistent with hypothermic circulatory arrest in association with retrograde cerebral perfusion via superior vena cava. We propose a simple, time-saving method, which does not require any manipulation of the heart. We use a multilumen cannula for cardioplegia (D 860-DIDECO FUNDARO') with pressure transducer. This cannula is inserted in superior vena cava by means of a simple purse-string, and linked to the arterial line with a "Y" derivation, allowing retrograde perfusion of the brain and monitoring the perfusion pressure at every moment. The superior vena cava placed downstream from the cannula is closed by a small vascular clamp, to avoid blood reflux in the right atrium. This method is time- and money-saving, is readily available, and can be prepared whenever necessary, also in the middle of the surgical procedure. PMID:7488786

  13. Coronary artery occlusion extends perfusion territory boundaries through microvascular collaterals.

    PubMed

    Cicutti, N; Rakusan, K; Downey, H F

    1994-01-01

    Simultaneous in vivo infusions of two different colored 10 microns microsphere suspensions into the left anterior descending (LAD; red spheres) and left circumflex (LCx; blue spheres) coronary arteries of nine anesthetized dogs identified a specific region of canine myocardium perfused by both arterial branches. Subsequently, the LAD was ligated and a third (green) set of micropheres was infused into the patent LCx artery. Analysis of 40 microns serial sections of tissue revealed interface zones with capillaries perfused by both arteries. The first zone, defined as the Interface Transistion Zone (ITZ) was formed by an intermingling of microvessels supplied by the parent arteries of the adjacent perfusion territories; it separated tissue containing only one or the other colored microspheres. Another zone, defined as the Boundary Watershed Zone was located within the ITZ and had capillaries containing both red and blue microspheres. The width of ITZ was 53377 +/- 817 microns (mean +/- SD), and the width of the BWZ was 3358 +/- 618 microns. Green microspheres, infused into the LCx following coronary occlusion were also found in the ITZ and BWZ. Furthermore, capillaries perfused exclusively by the LAD before occlusion (tissue with red but not blue microspheres) adjacent to the perfusion interface contained green microspheres as well as red/green aggregates, indicating lateral extension of the LCx perfusion territory. This extension of the LCx territory was quantitated by comparing the location at which densities of green microspheres or green/red aggregates decreased abruptly compared to the location of the original ITZ and BWZ boundaries, respectively. Results showed that LAD occlusion caused a 24% expansion of the ITZ and a 48% expansion of the BWZ. In addition, all expansions were significantly greater in subepicardial compared to subendocardial regions (p < 0.001). These results clearly demonstrate the capability of microvascular anastomoses in providing blood flow

  14. An altered intestinal mucosal microbiome in HIV-1 infection is associated with mucosal and systemic immune activation and endotoxemia.

    PubMed

    Dillon, S M; Lee, E J; Kotter, C V; Austin, G L; Dong, Z; Hecht, D K; Gianella, S; Siewe, B; Smith, D M; Landay, A L; Robertson, C E; Frank, D N; Wilson, C C

    2014-07-01

    Human immunodeficiency virus-1 (HIV-1) infection disrupts the intestinal immune system, leading to microbial translocation and systemic immune activation. We investigated the impact of HIV-1 infection on the intestinal microbiome and its association with mucosal T-cell and dendritic cell (DC) frequency and activation, as well as with levels of systemic T-cell activation, inflammation, and microbial translocation. Bacterial 16S ribosomal DNA sequencing was performed on colon biopsies and fecal samples from subjects with chronic, untreated HIV-1 infection and uninfected control subjects. Colon biopsies of HIV-1-infected subjects had increased abundances of Proteobacteria and decreased abundances of Firmicutes compared with uninfected donors. Furthermore at the genus level, a significant increase in Prevotella and decrease in Bacteroides was observed in HIV-1-infected subjects, indicating a disruption in the Bacteroidetes bacterial community structure. This HIV-1-associated increase in Prevotella abundance was associated with increased numbers of activated colonic T cells and myeloid DCs. Principal coordinates analysis demonstrated an HIV-1-related change in the microbiome that was associated with increased mucosal cellular immune activation, microbial translocation, and blood T-cell activation. These observations suggest that an important relationship exists between altered mucosal bacterial communities and intestinal inflammation during chronic HIV-1 infection. PMID:24399150

  15. An altered intestinal mucosal microbiome in HIV-1 infection is associated with mucosal and systemic immune activation and endotoxemia

    PubMed Central

    Dillon, SM; Lee, EJ; Kotter, CV; Austin, GL; Dong, Z; Hecht, DK; Gianella, S; Siewe, B; Smith, DM; Landay, AL; Robertson, CE; Frank, DN; Wilson, CC

    2014-01-01

    HIV-1 infection disrupts the intestinal immune system, leading to microbial translocation and systemic immune activation. We investigated the impact of HIV-1 infection on the intestinal microbiome and its association with mucosal T cell and dendritic cell (DC) frequency and activation, as well as with levels of systemic T cell activation, inflammation and microbial translocation. Bacterial 16S ribosomal DNA sequencing was performed on colon biopsies and fecal samples from subjects with chronic, untreated HIV-1 infection and uninfected control subjects. Colon biopsies of HIV-1 infected subjects had increased abundances of Proteobacteria and decreased abundances of Firmicutes compared to uninfected donors. Furthermore at the genus level, a significant increase in Prevotella and decrease in Bacteroides was observed in HIV-1 infected subjects, indicating a disruption in the Bacteroidetes bacterial community structure. This HIV-1-associated increase in Prevotella abundance was associated with increased numbers of activated colonic T cells and myeloid DCs. Principal coordinates analysis demonstrated an HIV-1-related change in the microbiome that was associated with increased mucosal cellular immune activation, microbial translocation and blood T cell activation. These observations suggest that an important relationship exists between altered mucosal bacterial communities and intestinal inflammation during chronic HIV-1 infection. PMID:24399150

  16. Evaluation of CT Perfusion Biomarkers of Tumor Hypoxia

    PubMed Central

    Qi, Qi; Yeung, Timothy Pok Chi; Lee, Ting-Yim; Bauman, Glenn; Crukley, Cathie; Morrison, Laura; Hoffman, Lisa; Yartsev, Slav

    2016-01-01

    Background Tumor hypoxia is associated with treatment resistance to cancer therapies. Hypoxia can be investigated by immunohistopathologic methods but such procedure is invasive. A non-invasive method to interrogate tumor hypoxia is an attractive option as such method can provide information before, during, and after treatment for personalized therapies. Our study evaluated the correlations between computed tomography (CT) perfusion parameters and immunohistopathologic measurement of tumor hypoxia. Methods Wistar rats, 18 controls and 19 treated with stereotactic radiosurgery (SRS), implanted with the C6 glioma tumor were imaged using CT perfusion on average every five days to monitor tumor growth. A final CT perfusion scan and the brain were obtained on average 14 days (8–22 days) after tumor implantation. Tumor hypoxia was detected immunohistopathologically with pimonidazole. The tumor, necrotic, and pimonidazole-positive areas on histology samples were measured. Percent necrotic area and percent hypoxic areas were calculated. Tumor volume (TV), blood flow (BF), blood volume (BV), and permeability-surface area product (PS) were obtained from the CT perfusion studies. Correlations between CT perfusion parameters and histological parameters were assessed by Spearman’s ρ correlation. A Bonferroni-corrected P value < 0.05 was considered significant. Results BF and BV showed significant correlations with percent hypoxic area ρ = -0.88, P < 0.001 and ρ = -0.81, P < 0.001, respectively, for control animals and ρ = -0.7, P < 0.001 and ρ = -0.6, P = 0.003, respectively, for all animals, while TV and BV were correlated (ρ = -0.64, P = 0.01 and ρ = -0.43, P = 0.043, respectively) with percent necrotic area. PS was not correlated with either percent necrotic or percent hypoxic areas. Conclusions Percent hypoxic area provided significant correlations with BF and BV, suggesting that CT perfusion parameters are potential non-invasive imaging biomarkers of tumor

  17. Influence of Thin Slice Reconstruction on CT Brain Perfusion Analysis

    PubMed Central

    Bennink, Edwin; Oosterbroek, Jaap; Horsch, Alexander D.; Dankbaar, Jan Willem; Velthuis, Birgitta K.; Viergever, Max A.; de Jong, Hugo W. A. M.

    2015-01-01

    Objectives Although CT scanners generally allow dynamic acquisition of thin slices (1 mm), thick slice (≥5 mm) reconstruction is commonly used for stroke imaging to reduce data, processing time, and noise level. Thin slice CT perfusion (CTP) reconstruction may suffer less from partial volume effects, and thus yield more accurate quantitative results with increased resolution. Before thin slice protocols are to be introduced clinically, it needs to be ensured that this does not affect overall CTP constancy. We studied the influence of thin slice reconstruction on average perfusion values by comparing it with standard thick slice reconstruction. Materials and Methods From 50 patient studies, absolute and relative hemisphere averaged estimates of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and permeability-surface area product (PS) were analyzed using 0.8, 2.4, 4.8, and 9.6 mm slice reconstructions. Specifically, the influence of Gaussian and bilateral filtering, the arterial input function (AIF), and motion correction on the perfusion values was investigated. Results Bilateral filtering gave noise levels comparable to isotropic Gaussian filtering, with less partial volume effects. Absolute CBF, CBV and PS were 22%, 14% and 46% lower with 0.8 mm than with 4.8 mm slices. If the AIF and motion correction were based on thin slices prior to reconstruction of thicker slices, these differences reduced to 3%, 4% and 3%. The effect of slice thickness on relative values was very small. Conclusions This study shows that thin slice reconstruction for CTP with unaltered acquisition protocol gives relative perfusion values without clinically relevant bias. It does however affect absolute perfusion values, of which CBF and CBV are most sensitive. Partial volume effects in large arteries and veins lead to overestimation of these values. The effects of reconstruction slice thickness should be taken into account when absolute perfusion values are

  18. The effect of honey on mucositis induced by chemoradiation in head and neck cancer.

    PubMed

    Maiti, Pradip Kumar; Ray, Amitabh; Mitra, Tarak Nath; Jana, Utpal; Bhattacharya, Jibak; Ganguly, Subir

    2012-07-01

    The aim of this study was to evaluate the effect of pure natural honey on radiation-induced mucositis. Fifty-five patients diagnosed with head and neck cancer requiring radiation to the oropharyngeal mucosal area were divided into two groups (study arm-28 and control arm-27) to receive either chemoradiation or chemoradiation plus topical application of honey. Patients were treated using a telecobalt machine at 2 Gy per day, five times a week up to a total dose of 66 Gy. in the study arm, patients were advised to take 20 ml of honey 15 minutes before, 15 minutes after and similar amount at bed time. Patients were evaluated every week for the development of radiation mucositis using the WHO grading system. There was significant reduction in the symptomatic grades 3 and 4 mucositis in honey-treated patients compared to controls ie, 18% versus 41% for grade 3 and 4% versus 22% for grade 4 mucositis. Seventy-one per cent of patients treated with topical honey showed no change or a positive gain in body weight. In the control group also 22% had no weight loss, though none showed weight gain. Furthermore, it didn't affect blood sugar level when initial fasting blood sugar level was < 150 mg%. Honey is a cheap, simple, easily available and effective agent in reducing radiation-induced mucositis. Within the limits of this study the results showed the application of natural honey is effective in managing radiation induced mucositis, which warrants further multicentric randomised trials to validate the findings. PMID:23520669

  19. Modelling of temperature and perfusion during scalp cooling

    NASA Astrophysics Data System (ADS)

    Janssen, F. E. M.; Van Leeuwen, G. M. J.; Van Steenhoven, A. A.

    2005-09-01

    Hair loss is a feared side effect of chemotherapy treatment. It may be prevented by cooling the scalp during administration of cytostatics. The supposed mechanism is that by cooling the scalp, both temperature and perfusion are diminished, affecting drug supply and drug uptake in the hair follicle. However, the effect of scalp cooling varies strongly. To gain more insight into the effect of cooling, a computer model has been developed that describes heat transfer in the human head during scalp cooling. Of main interest in this study are the mutual influences of scalp temperature and perfusion during cooling. Results of the standard head model show that the temperature of the scalp skin is reduced from 34.4 °C to 18.3 °C, reducing tissue blood flow to 25%. Based upon variations in both thermal properties and head anatomies found in the literature, a parameter study was performed. The results of this parameter study show that the most important parameters affecting both temperature and perfusion are the perfusion coefficient Q10 and the thermal resistances of both the fat and the hair layer. The variations in the parameter study led to skin temperature ranging from 10.1 °C to 21.8 °C, which in turn reduced relative perfusion to 13% and 33%, respectively.

  20. Protective effect of coadministered superoxide dismutase and catalase against stress-induced gastric mucosal lesions.

    PubMed

    Ohta, Yoshiji; Nishida, Keiji

    2003-08-01

    gastric mucosal lesion formation and the levels of serum and gastric mucosal parameters studied. 4. These results indicate that coadministered native SOD and catalase protect against gastric mucosal lesions in rats with WIR stress and suggest that this protective effect of coadministered native SOD and catalase could be due to their activity to scavenge XO-derived active oxygen species that are increased in the blood. PMID:12890175

  1. Treatment of oral mucositis due to chemotherapy

    PubMed Central

    Bagán-Sebastián, José V

    2016-01-01

    Introduction The management of oral mucositis is a challenge, due to its complex biological nature. Over the last 10 years, different strategies have been developed for the management of oral mucositis caused by chemotherapy in cancer patients. Material and Methods An exhaustive search was made of the PubMed-Medline, Cochrane Library and Scopus databases, crossing the key words “oral mucositis”, “prevention” and “treatment” with the terms “chemotherapy” and “radiotherapy” by means of the boolean operators “AND” and “NOT”. A total of 268 articles were obtained, of which 96 met the inclusion criteria. Results Several interventions for the prevention of oral mucositis, such as oral hygiene protocols, amifostine, benzidamine, calcium phosphate, cryotherapy and iseganan, among others, were found to yield only limited benefits. Other studies have reported a decrease in the appearance and severity of mucositis with the use of cytoprotectors (sucralfate, oral glutamine, hyaluronic acid), growth factors, topical polyvinylpyrrolidone, and low power laser irradiation. Conclusions Very few interventions of confirmed efficacy are available for the management of oral mucositis due to chemotherapy. However, according to the reviewed literature, the use of palifermin, cryotherapy and low power laser offers benefits, reducing the incidence and severity of oral mucositis – though further studies are needed to confirm the results obtained. Key words:Chemotherapy-Induced Oral Mucositis Treatment. PMID:27034762

  2. Ventilation-perfusion scintiscanning in tropical pulmonary eosinophilia.

    PubMed

    Ray, D; Jayachandran, C A

    1993-08-01

    We report the findings of ventilation and perfusion scintiscanning performed in three untreated patients with acute tropical pulmonary eosinophilia (TPE). In a 26-year-old man whose arterial blood gas values were normal, the lung scan showed normal radioactivity. The scintigrams of a 20-year-old woman who had hypoxemia and hypercapnea showed gross ventilation defects of both lungs that were mainly mismatched; changes in the perfusion scan were minimal. Scintiscanning in a 14-year-old girl who had moderate arterial hypoxia and mild hypocapnea, on the other hand, showed ventilation defects in both lungs, more marked in left lung; multiple matching ventilation-perfusion defects were also seen; however, the V/Q defects did not appear to be equally matched. The scintigraphic findings were compatible with arterial blood gas status of the individual patients and consistent with the notion that a disturbed ventilation-perfusion relationship may be responsible for hypoxemia in some of the patients with TPE. PMID:8339640

  3. Susceptibility-Based Analysis Of Dynamic Gadolinium Bolus Perfusion MRI

    PubMed Central

    Bonekamp, David; Barker, Peter B.; Leigh, Richard; van Zijl, Peter C.M.; Li, Xu

    2014-01-01

    Purpose An algorithm is developed for the reconstruction of dynamic, gadolinium (Gd) bolus MR perfusion images of the human brain, based on quantitative susceptibility mapping (QSM). Methods The method is evaluated in 5 perfusion scans obtained from 4 different patients scanned at 3T, and compared to the conventional analysis based on changes in the transverse relaxation rate ΔR2* and to theoretical predictions. QSM images were referenced to ventricular CSF for each dynamic of the perfusion sequence. Results Images of cerebral blood flow and blood volume were successfully reconstructed from the QSM-analysis, and were comparable to those reconstructed using ΔR2*. The magnitudes of the Gd-associated susceptibility effects in gray and white matter were consistent with theoretical predictions. Conclusion QSM-based analysis may have some theoretical advantages compared to ΔR2*, including a simpler relationship between signal change and Gd concentration. However, disadvantages are its much lower contrast-to-noise ratio, artifacts due to respiration and other effects, and more complicated reconstruction methods. More work is required to optimize data acquisition protocols for QSM-based perfusion imaging. PMID:24604343

  4. Pulsatile roller pump perfusion is safe in high risk patients.

    PubMed

    Kocakulak, M; Küçükaksu, S; Pişkin, E

    2004-05-01

    In this study, controllability, safety, blood cell depletion, and hemolysis of a pulsatile roller pump in high-risk patients was evaluated. Sarns 8000 roller pump (Sams, Terumo CVS, Ann Arbor, MI, USA) with a pulsatile control module was used as arterial pump in a clinical setting. Forty patients undergoing elective open heart surgery with high-risk either having chronically obstructive pulmonary disease or chronic renal failure were randomly included in the study to be operated on using pulsatile perfusion or non-pulsatile perfusion. Blood samples were withdrawn at induction of anesthesia, at the time of aortic clamping and de-clamping and at 1 hour and 24 hours following cessation of the bypass. Hematocrit and plasma free hemoglobin values were measured. We observed that the pulsatile roller pump perfusion and the extracorporeal circuit used in the clinical study is safe in high-risk patients undergoing cardiopulmonary bypass. We did not face any emboli, hemolysis, or technical problems. Pulsatile roller pump perfusion with Sarns 8000 heart-lung machine is a simple and reliable technique and can be easily applied during open heart surgery. PMID:15202823

  5. Local Control of Blood Flow

    ERIC Educational Resources Information Center

    Clifford, Philip S.

    2011-01-01

    Organ blood flow is determined by perfusion pressure and vasomotor tone in the resistance vessels of the organ. Local factors that regulate vasomotor tone include myogenic and metabolic autoregulation, flow-mediated and conducted responses, and vasoactive substances released from red blood cells. The relative importance of each of these factors…

  6. The mucosal immune system for vaccine development.

    PubMed

    Lamichhane, Aayam; Azegamia, Tatsuhiko; Kiyonoa, Hiroshi

    2014-11-20

    Mucosal surfaces are continuously exposed to the external environment and therefore represent the largest lymphoid organ of the body. In the mucosal immune system, gut-associated lymphoid tissues (GALTs), including Peyer's patches and isolated lymphoid follicles, play an important role in the induction of antigen-specific immune responses in the gut. GALTs have unique organogenesis characteristics and interact with the network of dendritic cells and T cells for the simultaneous induction and regulation of IgA responses and oral tolerance. In these lymphoid tissues, antigens are up taken by M cells in the epithelial layer, and antigen-specific immune responses are subsequently initiated by GALT cells. Nasopharynx- and tear-duct-associated lymphoid tissues (NALTs and TALTs) are key organized lymphoid structures in the respiratory tract and ocular cavities, respectively, and have been shown to interact with each other. Mucosal surfaces are also characterized by host-microbe interactions that affect the genesis and maturation of mucosa-associated lymphoid tissues and the induction and regulation of innate and acquired mucosal immune responses. Because most harmful pathogens enter the body through mucosal surfaces by ingestion, inhalation, or sexual contact, the mucosa is a candidate site for vaccination. Mucosal vaccination has some physiological and practical advantages, such as decreased costs and reduced risk of needle-stick injuries and transmission of bloodborne diseases, and it is painless. Recently, the application of modern bioengineering and biochemical engineering technologies, including gene transformation and manipulation systems, resulted in the development of systems to express vaccine antigens in transgenic plants and nanogels, which will usher in a new era of delivery systems for mucosal vaccine antigens. In this review, based on some of our research group's thirty seven years of progress and effort, we highlight the unique features of mucosal immune

  7. A study on cerebral hemodynamic analysis of moyamoya disease by using perfusion MRI

    NASA Astrophysics Data System (ADS)

    Dong, Kyung-Rae; Goo, Eun-Hoe; Lee, Jae-Seung; Chung, Woon-Kwan

    2013-10-01

    This study examined the clinical applications of perfusion magnetic resonance imaging (MRI) in patients with moyamoya disease (MMD). Twenty-two patients with moyamoya disease (9 men and 13 women) with a mean age of 9.3 years (range: 4-22 years) were enrolled in this study. Perfusion MRI was performed by scanning the patients7.5 cm upward from the base of the cerebellum before their being process for post-treatment. The scan led to the acquisition of the following four map images: the cerebral blood volume (CBV), the cerebral blood flow (CBF), the mean transit time (MTT) for the contrast medium, and the time to peak (TTP) for the contrast medium. The lesions were assessed using the CBV, the CBF, the MTT and the TTP maps of perfusion MRI; the MTT and the TTP were measured in the lesion areas, as well as in the normal and the symmetric areas. Perfusion defects were recognizable in all four perfusion MRI maps, and the MTT and the TTP showed a conspicuous delay in the parts where perfusion defects were recognized. The MTT and the TTP images of perfusion MRI reflected a significant correlation between the degrees of stenosis and occlusion in the posterior cerebral artery (PCA), as well as the development of collateral vessels. The four perfusion MRI maps could be used to predict the degrees of stenosis and occlusion in the posterior circulation, as well as the development of the collateral vessels, which enabled a hemodynamic evaluation of the parts with perfusion defects. Overall, perfusion MRI is useful for the diagnosis and the treatment of moyamoya disease and can be applied to clinical practice.

  8. Palliation of radiation-related mucositis

    SciTech Connect

    Rothwell, B.R.; Spektor, W.S.

    1990-01-01

    Oral mucositis associated with head and neck radiotherapy can substantially hinder completion of cancer therapy. Alleviation of this often severe stomatitis can provide enhanced patient comfort and facilitate appropriate care. A double-blind format was used in a pilot project to measure, against a control rinse, the effectiveness of an oral rinse consisting of hydrocortisone, nystatin, tetracycline, and diphenhydramine in controlling radiation-related mucositis. A combination of clinical evaluation and patient responses to a questionnaire was used to judge the results of the topical medications. Patients using the experimental medication developed less mucositis than did patients in the control group.

  9. Oral mucositis. A complication of radiotherapy

    SciTech Connect

    Rider, C.A. )

    1990-11-01

    Oral mucositis is a complication of head and neck radiotherapy. It is understood what causes the inflammation and what biological tissue changes occur, however, a definite cure for oral mucositis has not yet been found. Supportive treatments, analgesics, antimicrobials and anti-inflammatory agents have been prescribed, none of which has been a thorough measure of treatment. An effective cure for oral mucositis is still in the midst of scientific research. In the interim local palliative treatments will help to alleviate the patients', debilitating symptoms.

  10. Monitoring Microcirculatory Blood Flow with a New Sublingual Tonometer in a Porcine Model of Hemorrhagic Shock

    PubMed Central

    Palágyi, Péter; Kaszaki, József; Rostás, Andrea; Érces, Dániel; Németh, Márton; Boros, Mihály; Molnár, Zsolt

    2015-01-01

    Tissue capnometry may be suitable for the indirect evaluation of regional hypoperfusion. We tested the performance of a new sublingual capillary tonometer in experimental hemorrhage. Thirty-six anesthetized, ventilated mini pigs were divided into sham-operated (n = 9) and shock groups (n = 27). Hemorrhagic shock was induced by reducing mean arterial pressure (MAP) to 40 mmHg for 60 min, after which fluid resuscitation started aiming to increase MAP to 75% of the baseline value (60–180 min). Sublingual carbon-dioxide partial pressure was measured by tonometry, using a specially coiled silicone rubber tube. Mucosal red blood cell velocity (RBCV) and capillary perfusion rate (CPR) were assessed by orthogonal polarization spectral (OPS) imaging. In the 60 min shock phase a significant drop in cardiac index was accompanied by reduction in sublingual RBCV and CPR and significant increase in the sublingual mucosal-to-arterial PCO2 gap (PSLCO2 gap), which significantly improved during the 120 min resuscitation phase. There was significant correlation between PSLCO2 gap and sublingual RBCV (r = −0.65, p < 0.0001), CPR (r = −0.64, p < 0.0001), central venous oxygen saturation (r = −0.50, p < 0.0001), and central venous-to-arterial PCO2 difference (r = 0.62, p < 0.0001). This new sublingual tonometer may be an appropriate tool for the indirect evaluation of circulatory changes in shock. PMID:26504837

  11. Monitoring Microcirculatory Blood Flow with a New Sublingual Tonometer in a Porcine Model of Hemorrhagic Shock.

    PubMed

    Palágyi, Péter; Kaszaki, József; Rostás, Andrea; Érces, Dániel; Németh, Márton; Boros, Mihály; Molnár, Zsolt

    2015-01-01

    Tissue capnometry may be suitable for the indirect evaluation of regional hypoperfusion. We tested the performance of a new sublingual capillary tonometer in experimental hemorrhage. Thirty-six anesthetized, ventilated mini pigs were divided into sham-operated (n = 9) and shock groups (n = 27). Hemorrhagic shock was induced by reducing mean arterial pressure (MAP) to 40 mmHg for 60 min, after which fluid resuscitation started aiming to increase MAP to 75% of the baseline value (60-180 min). Sublingual carbon-dioxide partial pressure was measured by tonometry, using a specially coiled silicone rubber tube. Mucosal red blood cell velocity (RBCV) and capillary perfusion rate (CPR) were assessed by orthogonal polarization spectral (OPS) imaging. In the 60 min shock phase a significant drop in cardiac index was accompanied by reduction in sublingual RBCV and CPR and significant increase in the sublingual mucosal-to-arterial PCO2 gap (PSLCO2 gap), which significantly improved during the 120 min resuscitation phase. There was significant correlation between PSLCO2 gap and sublingual RBCV (r = -0.65, p < 0.0001), CPR (r = -0.64, p < 0.0001), central venous oxygen saturation (r = -0.50, p < 0.0001), and central venous-to-arterial PCO2 difference (r = 0.62, p < 0.0001). This new sublingual tonometer may be an appropriate tool for the indirect evaluation of circulatory changes in shock. PMID:26504837

  12. Perfusion Angiography in Acute Ischemic Stroke.

    PubMed

    Scalzo, Fabien; Liebeskind, David S

    2016-01-01

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

  13. Perfusion Angiography in Acute Ischemic Stroke

    PubMed Central

    Liebeskind, David S.

    2016-01-01

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

  14. Optimization of arterial spin labeling MRI for quantitative tumor perfusion in a mouse xenograft model.

    PubMed

    Rajendran, Reshmi; Liang, Jieming; Tang, Mei Yee Annie; Henry, Brian; Chuang, Kai-Hsiang

    2015-08-01

    Perfusion is an important biomarker of tissue function and has been associated with tumor pathophysiology such as angiogenesis and hypoxia. Arterial spin labeling (ASL) MRI allows noninvasive and quantitative imaging of perfusion; however, the application in mouse xenograft tumor models has been challenging due to the low sensitivity and high perfusion heterogeneity. In this study, flow-sensitive alternating inversion recovery (FAIR) ASL was optimized for a mouse xenograft tumor. To assess the sensitivity and reliability for measuring low perfusion, the lumbar muscle was used as a reference region. By optimizing the number of averages and inversion times, muscle perfusion as low as 32.4 ± 4.8 (mean ± standard deviation) ml/100 g/min could be measured in 20 min at 7 T with a quantification error of 14.4 ± 9.1%. Applying the optimized protocol, heterogeneous perfusion ranging from 49.5 to 211.2 ml/100 g/min in a renal carcinoma was observed. To understand the relationship with tumor pathology, global and regional tumor perfusion was compared with histological staining of blood vessels (CD34), hypoxia (CAIX) and apoptosis (TUNEL). No correlation was observed when the global tumor perfusion was compared with these pathological parameters. Regional analysis shows that areas of high perfusion had low microvessel density, which was due to larger vessel area compared with areas of low perfusion. Nonetheless, these were not correlated with hypoxia or apoptosis. The results suggest that tumor perfusion may reflect certain aspect of angiogenesis, but its relationship with other pathologies needs further investigation. PMID:26104980

  15. Heterogeneity of cortical lesions in multiple sclerosis: an MRI perfusion study

    PubMed Central

    Peruzzo, Denis; Castellaro, Marco; Calabrese, Massimiliano; Veronese, Elisa; Rinaldi, Francesca; Bernardi, Valentina; Favaretto, Alice; Gallo, Paolo; Bertoldo, Alessandra

    2013-01-01

    In this study, dynamic susceptibility contrast-magnetic resonance imaging (DSC-MRI) was used to quantify the cerebral blood flow (CBF), the cerebral blood volume (CBV), and the mean transit time (MTT) and to analyze the changes in cerebral perfusion associated with the cortical lesions in 44 patients with relapsing-remitting multiple sclerosis. The cortical lesions showed a statistically significant reduction in CBF and CBV compared with the normal-appearing gray matter, whereas there were no significant changes in the MTT. The reduced perfusion suggests a reduction of metabolism because of the loss of cortical neurons. A small population of outliers showing an increased CBF and/or CBV has also been detected. The presence of hyperperfused outliers may imply that perfusion could evolve during inflammation. These findings show that perfusion is altered in cortical lesions and that DSC-MRI can be a useful tool to investigate more deeply the evolution of cortical lesions in multiple sclerosis. PMID:23250108

  16. MR Perfusion Imaging in Acute Ischemic Stroke

    PubMed Central

    Copen, William A.; Schaefer, Pamela W.; Wu, Ona

    2011-01-01

    MR perfusion imaging offers the potential for measuring brain perfusion in acute stroke patients, at a time when treatment decisions based upon these measurements may affect outcomes dramatically. Rapid advancements in both acute stroke therapy and perfusion imaging techniques have resulted in continuing redefinition of the role that perfusion imaging should play in patient management. This review first discusses the basic pathophysiology of acute stroke, with specific attention to alterations in the various perfusion-related parameters that can be studied by MR perfusion imaging. Although these parameters are sometimes treated as somewhat interchangeable, they reveal greatly different information about brain perfusion. Therefore, subsequent discussion of the utility of different kinds of perfusion images focuses on the differences between them, as well as important artifacts that can complicate their interpretation. Finally, research on the continually evolving role of MR perfusion imaging in acute stroke care is summarized. PMID:21640299

  17. Role of dynamic CT perfusion study in evaluating various intracranial space-occupying lesions

    PubMed Central

    Kamble, Ravindra B; Jayakumar, Peruvumba N; Shivashankar, Ravishankar

    2015-01-01

    Aims: Differentiating intracranial mass lesions on CT scan is challenging. The purpose of our study was to determine the perfusion parameters in various intracranial space-occupying lesions (ICSOL), differentiate benign and malignant lesions, and differentiate between grades of gliomas. Materials and Methods: We performed CT perfusion (CTP) in 64 patients, with age ranging from 17 to 68 years, having space-occupying lesions in brain and calculated relative cerebral blood flow (rCBF) and relative cerebral blood volume (rCBV). Results: We found significantly lower perfusion in low-grade gliomas as compared to high-grade tumors, lymphoma, and metastases. Similarly in infective lesions, TWT and abscesses showed significantly lower perfusion compared to TOT. In ring enhancing lesions, capsule of TWT showed significantly lower perfusion as compared to abscesses, TOT, and metastases. Conclusion: Thus, in conclusion, infective lesions can be differentiated from tumors like lymphomas, high-grade gliomas, or metastases based on perfusion parameters. The cut off value of rCBV 1.64 can be used to differentiate between low grade and high grade gliomas. However, depending only on perfusion parameters, differentiation between the tumors like lymphomas, high-grade gliomas, and metastases may not be possible. PMID:25969639

  18. Clearance of Immunoreactive Somatostatin by Perfused Rat Liver

    PubMed Central

    Sacks, Harold; Terry, L. Cass

    1981-01-01

    Other investigators have demonstrated that concentrations of immunoreactive somatostatin (IRS) are higher in blood from the hepatic portal vein or its tributaries than in blood from the hepatic or peripheral systemic veins of man and animals. This suggests that there is hepatic extraction of IRS from the portal system in vivo. In the rat, portal vein plasma IRS is reported to be heterogeneous and to contain, in part, a 1,600 mol wt form of IRS which is immunochemically similar to synthetic somatostatin and not significantly bound to high molecular weight plasma protein. Our study was undertaken to determine directly whether unbound synthetic cyclic somatostatin was cleared by the rat liver perfused through the hepatic portal vein in vitro with a recirculating, plasma-free, erythrocyte-containing perfusate. At 37°C and pH 7.40, perfusate IRS, at initial concentrations (1,728 pg/ml) within the range previously reported in rat portal venous blood, was removed by the liver at a rate commensurate with first-order kinetics. Hepatic clearance was 0.84±0.04 ml/min per g postperfusion wet weight (SE). Hepatic extraction was 36±2%, and t½ was 20.0±1.3 min. Recovery of IRS from the perfusate without the liver was >85%, excluding significant degradation by the medium. Clearance, extraction, and t½ of IRS were not changed by an unphysiologic IRS concentration (621,500 pg/ml), or by pharmacologic concentrations of insulin (8.2 μM) or glucagon (2.9 μM). The t½ was prolonged significantly to 28.2±1.9 and 45.6±4.7 min during perfusions at liver temperatures of 25° and 16°C, respectively. At 37°C, the t½ was also significantly increased to 28.7±3.2 and 24.2±1.1 min at perfusate pH 7.06 and 6.78, respectively. These studies indicate that the rat liver clears unbound IRS from the perfusate by a first-order kinetic process that is (a) unsaturable at pharmacologic concentrations, (b) temperature-sensitive and, to a lesser extent, influenced by lowered pH, and (c) not

  19. Mucosal Antibodies Induced by Intranasal but Not Intramuscular Immunization Block Norovirus GII.4 Virus-Like Particle Receptor Binding.

    PubMed

    Tamminen, Kirsi; Malm, Maria; Vesikari, Timo; Blazevic, Vesna

    2016-06-01

    Noroviruses (NoVs) account for the majority of diagnosed cases of viral acute gastroenteritis worldwide. Virus-like particle (VLP)-based vaccines against NoV are currently under development. Serum antibodies that block the binding of NoV VLPs to histo-blood group antigens, the putative receptors for NoV, correlate with protection against NoV infection. The role of functional mucosal antibodies in protection is largely unknown, even though the intestinal mucosa is the entry port for NoV. Balb/c mice were immunized intramuscularly (IM) or intranasally (IN) with NoV GII.4 VLPs, and systemic and mucosal blocking antibody responses were studied. IN immunization elicited NoV-specific serum and mucosal IgG and IgA antibodies, whereas IM immunized animals completely lacked IgA. Both immunization routes induced similar blocking activity in serum but only IN route generated blocking antibodies in mucosa. The level of IgA in the mucosal (nasal) lavages strongly correlated (r = 0.841) with the blocking activity, suggesting that IgA, but not IgG, is the major NoV blocking antibody on mucosal surfaces. The results indicate that only mucosal immunization route induces the development of functional anti-NoV IgA on mucosal surface. PMID:27135874

  20. Microbiota and Mucosal Immunity in Amphibians

    PubMed Central

    Colombo, Bruno M.; Scalvenzi, Thibault; Benlamara, Sarah; Pollet, Nicolas

    2015-01-01

    We know that animals live in a world dominated by bacteria. In the last 20 years, we have learned that microbes are essential regulators of mucosal immunity. Bacteria, archeas, and viruses influence different aspects of mucosal development and function. Yet, the literature mainly covers findings obtained in mammals. In this review, we focus on two major themes that emerge from the comparative analysis of mammals and amphibians. These themes concern: (i) the structure and functions of lymphoid organs and immune cells in amphibians, with a focus on the gut mucosal immune system; and (ii) the characteristics of the amphibian microbiota and its influence on mucosal immunity. Lastly, we propose to use Xenopus tadpoles as an alternative small-animal model to improve the fundamental knowledge on immunological functions of gut microbiota. PMID:25821449

  1. Exploiting Mucosal Immunity for Antiviral Vaccines.

    PubMed

    Iwasaki, Akiko

    2016-05-20

    Mucosal surfaces provide a remarkably effective barrier against potentially dangerous pathogens. Therefore, enhancing mucosal immunity through vaccines-strengthening that first line of defense-holds significant promise for reducing the burden of viral diseases. The large and varied class of viral pathogens, however, continues to present thorny challenges to vaccine development. Two primary difficulties exist: Viruses exhibit a stunning diversity of strategies for evading the host immune response, and even when we understand the nature of effective immune protection against a given virus, eliciting that protection is technically challenging. Only a few mucosal vaccines have surmounted these obstacles thus far. Recent developments, however, could greatly improve vaccine design. In this review, we first sketch out our understanding of mucosal immunity and then compare the herpes simplex virus, human immunodeficiency virus, and influenza virus to illustrate the distinct challenges of developing successful vaccines and to outline potential solutions. PMID:27168245

  2. Localized Pemphigus Vegetans without Mucosal Involvement

    PubMed Central

    Jain, VK; Jindal, N; Imchen, S

    2014-01-01

    Pemphigus vegetans is a rare variant of pemphigus vulgaris. A 62-year-old woman presented with erythematous moist vegetative plaque on the left breast and left groin. There was no mucosal involvement. Histopathological and direct immunofluorescence findings were suggestive of pemphigus vegetans. She showed excellent response to oral steroids. Literature is scarcely available on the limited involvement with pemphigus vegetans without mucosal involvement. PMID:24700958

  3. Murine CMV infection induces the continuous production of mucosal resident T cells

    PubMed Central

    Smith, Corinne J.; Caldeira-Dantas, Sofia; Turula, Holly; Snyder, Christopher M.

    2015-01-01

    Summary Cytomegalovirus (CMV) is a herpesvirus that persists for life and maintains extremely large numbers of T cells with select specificities in circulation. However, it is unknown how viral persistence impacts T cell populations in mucosal sites. We found that many murine (M)CMV-specific CD8s in mucosal tissues became resident memory T cells (TRM). These cells adopted an intraepithelial localization in the salivary gland that correlated with, but did not depend on, expression of the integrin CD103. MCMV-specific TRM cells formed early after infection and spleen-localized cells had reduced capacities to become TRM at late times. Surprisingly however, small numbers of new TRM cells were formed from the circulating pool throughout infection, favoring populations maintained at high levels in the blood and shifting the immunodominance within the TRM populations over time. These data show that mucosal TRM populations can be dynamically maintained by a persistent infection. PMID:26526996

  4. Intragastric inulin as a measure of mucosal damage caused by aspirin

    SciTech Connect

    Wittmers, L.E. Jr.; Anderson, L.A.; Fall, M.M.; Alich, A.A. )

    1990-11-01

    In an attempt to find a method of gastric mucosal damage assessment that yields consistent results, the experiments presented here employed the measurement of the movement of inulin out of the gastric contents into the stomach wall and vascular compartment as an estimate of mucosal damage. Anesthetized male Sprague-Dawley rats were functionally nephrectomized and were administered a control or test solution containing 3H-inulin. The test solutions contained one of three doses of aspirin. Blood samples were taken at 15-min intervals over a 90-min exposure period. The stomach was removed from the animal and full-thickness tissue samples taken for measurement of 3H-inulin content. When the gastric mucosa was exposed to the test agents, there was a significantly greater accumulation of inulin in the body and antrum as well as in the plasma when compared to controls. We conclude that intragastric inulin can be employed to estimate gastric mucosal damage.

  5. Effects of intraepithelial lymphocyte-derived cytokines on intestinal mucosal barrier function.

    PubMed

    Qiu, Yuan; Yang, Hua

    2013-10-01

    The mucosal surface of the gastrointestinal tract directly interacts with the mucosal lumen, which is continuously exposed to foreign antigens. Specialized intraepithelial lymphocytes (IELs), located between the basolateral surfaces of the epithelial cells, are important as the first line of defense against microbes as well as for their role in the maintenance of epithelial barrier homeostasis. Although IELs are mainly composed of T cells, they are phenotypically and functionally distinct from T cells in peripheral blood or the spleen. Not only are IELs stimulated by the antigens of the intestinal lumen but are they also stimulated by regulatory immune cells. The integrity of the intestinal mucosal barrier is closely tied to the IEL function. Cytokines produced by IELs modulate the cellular functions that trigger the downstream signaling pathways and mediate the barrier homeostasis. In this review, we will address the broad spectrum of cytokines that are derived from IELs and the functional regulation of these cytokines on the intestinal barrier. PMID:23692551

  6. Lactose maldigestion during methotrexate-induced gastrointestinal mucositis in a rat model.

    PubMed

    Fijlstra, M; Rings, E H H M; Verkade, H J; van Dijk, T H; Kamps, W A; Tissing, W J E

    2011-02-01

    Patients with chemotherapy-induced gastrointestinal mucositis suffer from anorexia, diarrhea, and stomach pain, often causing weight loss and malnutrition. When the intestinal function during mucositis would be known, a rational feeding strategy might improve the nutritional state, accelerate recuperation, and increase survival of mucositis patients. We developed a methotrexate (MTX)-induced mucositis rat model to study nutrient digestion and absorption. To determine lactose digestion and absorption of its derivative glucose during mucositis, we injected Wistar rats intravenously with MTX (60 mg/kg) or 0.9% NaCl (controls). Four days later, we orally administered trace amounts of [1-(13)C]lactose and [U-(13)C]glucose and quantified the appearance of labeled glucose in the blood for 3 h. Finally, we determined plasma citrulline level and harvested the small intestine to assess histology, myeloperoxidase level, glycohydrolase activity, immunohistochemical protein, and mRNA expression. MTX-treated rats showed profound villus atrophy and epithelial damage. During the experimental period, the absorption of lactose-derived [1-(13)C]glucose was 4.2-fold decreased in MTX-treated rats compared with controls (P < 0.01). Lactose-derived [1-(13)C]glucose absorption correlated strongly with villus length (rho = 0.86, P < 0.001) and with plasma citrulline level (rho = 0.81, P < 0.001). MTX treatment decreased jejunal lactase activity (19.5-fold, P < 0.01) and immunohistochemical protein and mRNA expression (39.7-fold, P < 0.01) compared with controls. Interestingly, MTX treatment did not affect the absorption of [U-(13)C]glucose during the experimental period. We conclude that lactose digestion is severely decreased during mucositis while glucose absorption is still intact, when supplied in trace amounts. Plasma citrulline level might be a useful objective, noninvasive marker for lactose maldigestion during mucositis in clinic. PMID:21088238

  7. Intestinal inflammation and mucosal barrier function.

    PubMed

    Sánchez de Medina, Fermín; Romero-Calvo, Isabel; Mascaraque, Cristina; Martínez-Augustin, Olga

    2014-12-01

    Intestinal mucosal barrier function is the capacity of the intestine to provide adequate containment of luminal microorganisms and molecules while preserving the ability to absorb nutrients. The central element is the epithelial layer, which physically separates the lumen and the internal milieu and is in charge of vectorial transport of ions, nutrients, and other substances. The secretion of mucus-forming mucins, sIgA, and antimicrobial peptides reinforces the mucosal barrier on the extraepithelial side, while a variety of immune cells contributes to mucosal defense in the inner side. Thus, the mucosal barrier is of physical, biochemical, and immune nature. In addition, the microbiota may be viewed as part of this system because of the mutual influence occurring between the host and the luminal microorganisms. Alteration of the mucosal barrier function with accompanying increased permeability and/or bacterial translocation has been linked with a variety of conditions, including inflammatory bowel disease. Genetic and environmental factors may converge to evoke a defective function of the barrier, which in turn may lead to overt inflammation of the intestine as a result of an exacerbated immune reaction toward the microbiota. According to this hypothesis, inflammatory bowel disease may be both precipitated and treated by either stimulation or downregulation of the different elements of the mucosal barrier, with the outcome depending on timing, the cell type affected, and other factors. In this review, we cover briefly the elements of the barrier and their involvement in functional defects and the resulting phenotype. PMID:25222662

  8. Role of bombesin on gut mucosal growth.

    PubMed Central

    Chu, K U; Evers, B M; Ishizuka, J; Townsend, C M; Thompson, J C

    1995-01-01

    OBJECTIVE: The authors examined the effects of exogenous bombesin (BBS) on gut mucosal growth in chow-fed rats and the mucosal regeneration after gut atrophy brought about by feeding an elemental diet and after intestinal injury produced by methotrexate (MTX). SUMMARY BACKGROUND DATA: Bombesin is one of many gastrointestinal peptides implicated in the regulation of gut mucosal growth. Although BBS is known to stimulate growth of normal pancreatic tissue, the trophic effect of BBS on gut mucosa is less clear and its exact role in gut mucosal regeneration and repair is not known. METHODS: Rats were fed a regular chow diet (control) or an elemental diet plus either saline or BBS (10 micrograms/kg). In another experiment, rats fed a chow diet and treated with saline or BBS were given MTX (20 micrograms/kg) or a single intraperitoneal injection. In all experiments, small and large bowel mucosa and pancreas were removed and analyzed for BBS-mediated proliferation. RESULTS: Bombesin produced significant mucosal proliferation of the small bowel at day 14, but not at day 7, in rats fed regular chow. In contrast, BBS treatment for 7 days produced significant proliferation in both the atrophic and injured gut mucosa of rats given elemental diet or MTX. CONCLUSIONS: Bombesin may be an important enterotrophic factor for normal mucosal proliferation and may be clinically beneficial as an agent to restore or maintain gut mucosa during periods of atrophy or injury. PMID:7618976

  9. Mucosal Immunology of HIV Infection

    PubMed Central

    Xu, Huanbin; Wang, Xiaolei; Veazey, Ronald S.

    2013-01-01

    Summary Recent advances in the immunology, pathogenesis, and prevention of human immunodeficiency virus (HIV) infection continue to reveal clues to the mechanisms involved in the progressive immunodeficiency attributed to infection but more importantly have shed light on the correlates of immunity to infection and disease progression. HIV selectively infects, eliminates, and/or dysregulates several key cells of the human immune system, thwarting multiple arms of the host immune response, and inflicting severe damage to mucosal barriers, resulting in tissue infiltration of ‘symbiotic’ intestinal bacteria and viruses that essentially become opportunistic infections promoting systemic immune activation. This leads to activation and recruitment or more target cells for perpetuating HIV infection, resulting in persistent, high level viral replication in lymphoid tissues, rapid evolution of resistant strains, and continued evasion of immune responses. However, vaccine studies and studies of spontaneous controllers are finally providing correlates of immunity from protection and disease progression, including virus-specific CD4+ T-cell responses, binding antibodies, innate immune responses, and generation of antibodies with potent antibody-dependent cell-mediated cytotoxicity activity. Emerging correlates of immunity indicate that prevention of HIV infection may be possible through effective vaccine strategies that protect and stimulate key regulatory cells and immune responses in susceptible hosts. Further, immune therapies specifically directed towards boosting specific aspects of the immune system may eventually lead to a cure for HIV-infected patients. PMID:23772612

  10. Photoacoustic perfusion measurements: a comparison with power Doppler in phantoms

    NASA Astrophysics Data System (ADS)

    Heres, H. M.; Arabul, M. Ü.; Tchang, B. C.; van de Vosse, F. N.; Rutten, M. C.; Lopata, R. G.

    2015-03-01

    Ultrasound-based measurements using Doppler, contrast, and more recently photoacoustics (PA), have emerged as techniques for tissue perfusion measurements. In this study, the feasibility of in vitro perfusion measurements with a fully integrated, hand-held, photoacoustic probe was investigated and compared to Power Doppler (PD). Three cylindrical polyvinyl alcohol (PVA) phantoms were made (diameter = 15 mm) containing 100, 200 and 400 parallel polysulfone tubes (diameter = 0.2 mm), resulting in a perfused cross-sectional area of 1.8, 3.6 and 7.1% respectively. Each phantom was perfused with porcine blood (15 mL/min). Cross-sectional PA images (λ = 805nm, frame rate = 10Hz) and PD images (PRF = 750Hz) were acquired with a MyLab One and MyLab 70 scanner (Esaote, NL), respectively. Data were averaged over 70 frames. The average PA signal intensity was calculated in a region-of-interest of 4 mm by 6 mm. The percentage of colored PD pixels was measured in the entire phantom region. The average signal intensity of the PA images increased linearly with perfusion density, being 0.54 (+/- 0.01), 0.56 (+/- 0.01), 0.58 (+/- 0.01) with an average background signal of 0.53 in the three phantoms, respectively. For PD, the percentage of colored pixels in the phantom area (1.5% (+/- 0.2%), 4.4% (+/- 0.2%), 13.7% (+/- 0.8%)) also increased linearly. The preliminary results suggest that PA, like PD, is capable of detecting an increase of blood volume in tissue. In the future, in vivo measurements will be explored, although validation will be more complex.

  11. Laser Doppler imaging of myocardial perfusion during coronary bypass surgery

    NASA Astrophysics Data System (ADS)

    Wardell, Karin; Hermansson, Ulf; Nilsson, Gert E.; Casimir-Ahn, Henrik

    2000-05-01

    Laser Doppler perfusion imaging has been used to assess the myocardium perfusion on the arrested heart during bypass surgery. Twenty-two patients undergoing coronary artery bypass grafting, including usage of the left internal thoracic artery, were included in the study. The anticipated perfusion increase following declamping of the internal thoracic artery was investigated by mapping areas at the size of 10 cm X 11 cm, (n equals 11) and 7 cm X 5 cm (n equals 11). The larger images allowed quantification of blood flow in different regions of the myocardium. The size of the affected area was 32.2 +/- 12.9 cm2 with a total increase of 3.17 +/- 0.75 a.u. (range 0 - 10 a.u.). Corresponding values for areas surrounding the vessels and areas defined as the larger vessels in the myocardium were 29.0 +/- 10.9 cm2 (2.85 +/- 0.57 a.u.) and 3.5 +/- 2.8 cm2 (6.78 +/- 0.18 a.u.). All subjects but two showed a substantial blood flow increase (> 2 a.u.) after release of the clamp. Six subjects had a total increase of at least 4 a.u. Correlation analysis between areas including various number of sites showed an r equals 0.91 (p < 0,0001) or better. In conclusion, laser Doppler perfusion imaging can easily be used intraoperatively in conjunction with bypass surgery. It enables immediate assessment of both the increase and spatial distribution of myocardial perfusion following declamping of an arterial graft.

  12. Increased Mucosal CD4+ T Cell Activation in Rhesus Macaques following Vaccination with an Adenoviral Vector

    PubMed Central

    Bukh, Irene; Calcedo, Roberto; Roy, Soumitra; Carnathan, Diane G.; Grant, Rebecca; Qin, Qiuyue; Boyd, Surina; Ratcliffe, Sarah J.; Veeder, Christin L.; Bellamy, Scarlett L.; Betts, Michael R.

    2014-01-01

    ABSTRACT The possibility that vaccination with adenovirus (AdV) vectors increased mucosal T cell activation remains a central hypothesis to explain the potential enhancement of HIV acquisition within the Step trial. Modeling this within rhesus macaques is complicated because human adenoviruses, including human adenovirus type 5 (HAdV-5), are not endogenous to macaques. Here, we tested whether vaccination with a rhesus macaque-derived adenoviral vector (simian adenovirus 7 [SAdV-7]) enhances mucosal T cell activation within rhesus macaques. Following intramuscular SAdV-7 vaccination, we observed a pronounced increase in SAdV-7-specific CD4+ T cell responses in peripheral blood and, more dramatically, in rectal mucosa tissue. Vaccination also induced a significant increase in the frequency of activated memory CD4+ T cells in SAdV-7- and HAdV-5-vaccinated animals in the rectal mucosa but not in peripheral blood. These fluctuations within the rectal mucosa were also associated with a pronounced decrease in the relative frequency of naive resting CD4+ T cells. Together, these results indicate that peripheral vaccination with an AdV vector can increase the activation of mucosal CD4+ T cells, potentially providing an experimental model to further evaluate the role of host-vector interactions in increased HIV acquisition after AdV vector vaccination. IMPORTANCE The possibility that vaccination with a human adenovirus 5 vector increased mucosal T cell activation remains a central hypothesis to explain the potential enhancement of human immunodeficiency virus (HIV) acquisition within the Step trial. In this study, we tested whether vaccination with a rhesus macaque-derived adenoviral vector in rhesus macaques enhances mucosal CD4+ T cell activation, the main cell target of simian immunodeficiency virus (SIV)/HIV. The results showed that vaccination with an adenoviral vector indeed increases activation of mucosal CD4+ T cells and potentially increases susceptibility to SIV

  13. SALSA: A Regulator of the Early Steps of Complement Activation on Mucosal Surfaces

    PubMed Central

    Reichhardt, Martin Parnov; Meri, Seppo

    2016-01-01

    Complement is present mainly in blood. However, following mechanical damage or inflammation, serous exudates enter the mucosal surfaces. Here, the complement proteins interact with other endogenous molecules to keep microbes from entering the parenteral tissues. One of the mucosal proteins known to interact with the early complement components of both the classical and the lectin pathway is the salivary scavenger and agglutinin (SALSA). SALSA is also known as deleted in malignant brain tumors 1 and gp340. It is found both attached to the epithelium and secreted into the surrounding fluids of most mucosal surfaces. SALSA has been shown to bind directly to C1q, mannose-binding lectin, and the ficolins. Through these interactions SALSA regulates activation of the complement system. In addition, SALSA interacts with surfactant proteins A and D, secretory IgA, and lactoferrin. Ulcerative colitis and Crohn’s disease are examples of diseases, where complement activation in mucosal tissues may occur. This review describes the latest advances in our understanding of how the early complement components interact with the SALSA molecule. Furthermore, we discuss how these interactions may affect disease propagation on mucosal surfaces in immunological and inflammatory diseases. PMID:27014265

  14. [Immunoglobulin for prevention of radiogenic mucositis].

    PubMed

    Mose, S; Adamietz, I A; Thilmann, C; Saran, F; Heyd, R; Knecht, R; Böttcher, H D

    1995-07-01

    Among various therapies administered during radiation-induced mucositis, treatment with immunoglobulin has proven clinically successful. In this study the efficacy of prophylactic applications of immunoglobulin was investigated from January 1992 through August 1993. Forty-two patients with histologically-proven head and neck cancer were given postoperative radiation treatment. In cases with macroscopic tumor residues or inoperability, combined radio-chemotherapy was given. This included 51.3 Gy at 1.9 Gy 5x/week, boosted to 10-26 Gy at 2 Gy 5x/week and carboplatin 60 mg/m2 at days 1-5 and 29-33. Panthenol (4x10 ml/day) and nystatin (4 x 1 ml/day) were given to 20 patients as prophylactic treatment for mucositis. Twenty-two subsequent patients also received intramuscular 800 mg (5 ml) human immunoglobulin (1x/week). According to the Seegenschmiedt/Sauer classification the extent of mucositis was determined 3x/week. Comparison of the distribution of maximal mucositis revealed a slightly more severe mucosal reaction in the control group (n.s.). Analysis of the mean degree of mucositis in both groups demonstrated statistically significant differences (p = 0.031) related to the whole collective and patients receiving concomitant chemotherapy while no effect of immunoglobulin was found in patients treated by radiation alone. In the immunoglobulin-treated-group, the time from the beginning of therapy to the first interruption was prolonged 5 days (37.5 +/- 13.1 vs. 42.7 +/- 13.3 days), but this difference was not significant. Although prophylactic application of immunoglobulin seemed to lower the degree of radiation-induced mucositis, this effect was less significant when compared to the immunoglobulin given in a therapeutic manner. PMID:7672999

  15. Perfusion imaging with non-contrast ultrasound

    NASA Astrophysics Data System (ADS)

    Tierney, Jaime E.; Dumont, Douglas M.; Byram, Brett C.

    2016-04-01

    A Doppler ultrasound clutter filter that enables estimation of low velocity blood flow could considerably improve ultrasound as a tool for clinical diagnosis and monitoring, including for the evaluation of vascular diseases and tumor perfusion. Conventional Doppler ultrasound is currently used for visualizing and estimating blood flow. However, conventional Doppler is limited by frame rate and tissue clutter caused by involuntary movement of the patient or sonographer. Spectral broadening of the clutter due to tissue motion limits ultrasound's ability to detect blood flow less than about 5mm/s at an 8MHz center frequency. We propose a clutter filtering technique that may increase the sensitivity of Doppler measurements to at least as low as 0.41mm/s. The proposed filter uses an adaptive demodulation scheme that decreases the bandwidth of the clutter. To test the performance of the adaptive demodulation method at removing sonographer hand motion, six volunteer subjects acquired data from a basic quality assurance phantom. Additionally, to test initial in vivo feasibility, an arterial occlusion reactive hyperemia study was performed to assess the efficiency of the proposed filter at preserving signals from blood velocities 2mm/s or greater. The hand motion study resulted in initial average bandwidths of 577Hz (28.5mm/s), which were decreased to 7.28Hz (0.36mm/s) at -60 dB at 3cm using our approach. The in vivo power Doppler study resulted in 15.2dB and 0.15dB dynamic ranges between the lowest and highest blood flow time points for the proposed filter and conventional 50Hz high pass filter, respectively.

  16. Impact of Mucosal Inflammation on Oral Simian Immunodeficiency Virus Transmission

    PubMed Central

    Chen, Hui-Ling; Hodara, Vida L.; Chu, Lianrui; Parodi, Laura M.; Smith, Lisa M.; Sexton, Valerie; Cappelli, David; Sodora, Donald L.

    2013-01-01

    Mucosal tissues are the primary route of transmission for most respiratory and sexually transmitted diseases, including human immunodeficiency virus (HIV). There is epidemiological evidence that genital mucosal inflammation leads to enhanced HIV type 1 (HIV-1) transmission. The objective of this study was to assess the influence of periodontal inflammation on oral HIV transmission using a nonhuman primate model of teeth ligature-induced periodontitis. Simian immunodeficiency virus (SIV) was nontraumatically applied to the gingiva after moderate gingivitis was identified through clinical and immunologic analyses (presence of inflammatory cytokines). Overall oral SIV infection rates were similar in the gingivitis-induced and control groups (5 infections following 12 SIV administrations for each), although more macaques were infected with multiple viral variants in the gingivitis group. SIV infection also affected the levels of antiviral and inflammatory cytokines in the gingival crevicular fluid, and a synergistic effect was observed, with alpha interferon and interferon-inducible protein 10 undergoing significant elevations following SIV infection in macaques with gingivitis compared to controls. These increases in antiviral and inflammatory immune modulators in the SIV-infected gingivitis macaques could also be observed in blood plasma, although the effects at both compartments were generally restricted to the acute phase of the infection. In conclusion, while moderate gingivitis was not associated with increased susceptibility to oral SIV infection, it resulted in elevated levels of cytokines in the oral mucosa and plasma of the SIV-infected macaques. These findings suggest a synergy between mucosal inflammation and SIV infection, creating an immune milieu that impacts the early stages of the SIV infection with potential implications for long-term pathogenesis. PMID:23175379

  17. Technical Pitfalls of Signal Truncation in Perfusion MRI of Glioblastoma

    PubMed Central

    Wong, Kelvin K.; Fung, Steve H.; New, Pamela Z.; Wong, Stephen T. C.

    2016-01-01

    Dynamic susceptibility contrast (DSC) perfusion-weighted imaging (PWI) is widely used in clinical settings for the radiological diagnosis of brain tumor. The signal change in brain tissue in gradient echo-based DSC PWI is much higher than in spin echo-based DSC PWI. Due to its exquisite sensitivity, gradient echo-based sequence is the preferred method for imaging of all tumors except those near the base of the skull. However, high sensitivity also comes with a dynamic range problem. It is not unusual for blood volume to increase in gene-mediated cytotoxic immunotherapy-treated glioblastoma patients. The increase of fractional blood volume sometimes saturates the MRI signal during first-pass contrast bolus arrival and presents signal truncation artifacts of various degrees in the tumor when a significant amount of blood exists in the image pixels. It presents a hidden challenge in PWI, as this signal floor can be either close to noise level or just above and can go no lower. This signal truncation in the signal intensity time course is a significant issue that deserves attention in DSC PWI. In this paper, we demonstrate that relative cerebral blood volume and relative cerebral blood flow (rCBF) are underestimated due to signal truncation in DSC perfusion, in glioblastoma patients. We propose the use of second-pass tissue residue function in rCBF calculation using least-absolute-deviation deconvolution to avoid the underestimation problem. PMID:27531989

  18. Technical Pitfalls of Signal Truncation in Perfusion MRI of Glioblastoma.

    PubMed

    Wong, Kelvin K; Fung, Steve H; New, Pamela Z; Wong, Stephen T C

    2016-01-01

    Dynamic susceptibility contrast (DSC) perfusion-weighted imaging (PWI) is widely used in clinical settings for the radiological diagnosis of brain tumor. The signal change in brain tissue in gradient echo-based DSC PWI is much higher than in spin echo-based DSC PWI. Due to its exquisite sensitivity, gradient echo-based sequence is the preferred method for imaging of all tumors except those near the base of the skull. However, high sensitivity also comes with a dynamic range problem. It is not unusual for blood volume to increase in gene-mediated cytotoxic immunotherapy-treated glioblastoma patients. The increase of fractional blood volume sometimes saturates the MRI signal during first-pass contrast bolus arrival and presents signal truncation artifacts of various degrees in the tumor when a significant amount of blood exists in the image pixels. It presents a hidden challenge in PWI, as this signal floor can be either close to noise level or just above and can go no lower. This signal truncation in the signal intensity time course is a significant issue that deserves attention in DSC PWI. In this paper, we demonstrate that relative cerebral blood volume and relative cerebral blood flow (rCBF) are underestimated due to signal truncation in DSC perfusion, in glioblastoma patients. We propose the use of second-pass tissue residue function in rCBF calculation using least-absolute-deviation deconvolution to avoid the underestimation problem. PMID:27531989

  19. Pharmacokinetics of Antiretrovirals in Mucosal Tissue

    PubMed Central

    Cottrell, M.L.; Srinivas, N.; Kashuba, A.D.M.

    2015-01-01

    Introduction In the absence of an HIV vaccine or cure, antiretroviral (ARV) based prevention strategies are being investigated to reduce HIV incidence. These prevention strategies depend on achieving effective drug concentrations at the site HIV exposure which is most commonly the mucosal tissues of the lower gastrointestinal tract and the female genital tract. Areas covered This article collates all known data regarding drug exposure in these vulnerable mucosal tissues, and reviews important mechanisms of ARV drug distribution. Research papers and abstracts describing antiretroviral pharmacokinetics in the female genital tract and lower gastrointestinal mucosal tissues available in MEDLINE® or presented at scientific conferences prior to December 2014 are reviewed in detail. Important influences on ARV mucosal tissue distribution, including protein binding, active drug transport, and endogenous hormones, are also reviewed. Expert opinion ARVs exhibit highly variable pharmacokinetics in mucosal tissues. In general, antiretroviral exposure is higher in the lower gastrointestinal tract compared to the female genital tract, but concentrations required for protective efficacy are largely unknown. The expected site of HIV exposure represents an important consideration when designing and optimizing antiretroviral based prevention strategies. PMID:25797064

  20. Developing a tissue perfusion sensor.

    PubMed

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

    2007-01-01

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

  1. The effect of Aloe vera A. Berger (Liliaceae) on gastric acid secretion and acute gastric mucosal injury in rats.

    PubMed

    Yusuf, Sadiq; Agunu, Abdulkarim; Diana, Mshelia

    2004-07-01

    The effect of varying doses of ethanol extract of Aloe vera (Liliaceae) on acute gastric mucosal lesions induced by 0.6 M HCl and acid output was studied in the pylorus ligated and lumen perfuse rats, respectively. Acid secretion was determined by titration of the collected gastric juice to pH 7.0. Intraperitoneal injection of Aloe vera, dose dependently inhibited gastric acid secretion. The plant was more active as a gastroprotective agent at lower concentration against mucosal injury induced by 0.6 M HCl. In conclusion, Aloe vera is endowed with gastric acid anti-secretory activity and could protect the gastric mucosa at low concentrations against injurious agents. PMID:15182901

  2. Mucosal immune function comparison between amenorrheic and eumenorrheic distance runners.

    PubMed

    Shimizu, Kazuhiro; Suzuki, Natsumi; Nakamura, Mariko; Aizawa, Katsuji; Imai, Tomoko; Suzuki, Satomi; Eda, Nobuhiko; Hanaoka, Yukichi; Nakao, Kikuko; Suzuki, Naoto; Mesaki, Noboru; Kono, Ichiro; Akama, Takao

    2012-05-01

    This study examined the effects of amenorrhea on mucosal immune function and susceptibility to upper respiratory tract infection (URTI) in elite female distance runners. Based on their menstrual cycles during the prior year, 21 elite, collegiate, female distance runners were designated as eumenorrheic runners (ERs; n = 8; 19.9 ± 0.8 years) or amenorrheic runners (ARs; n n = 13; 20.0 ± 0.3 years). Resting saliva and blood samples were collected in the morning. The secretory immunoglobulin A (SIgA) concentration was measured using enzyme-linked immunosorbent assay. The SIgA secretion rate was calculated. Serum 17β-estradiol concentrations and serum progesterone concentrations were measured using radioimmunoassay. Subjects reported the appearance of URTI symptoms (sore throat, headache, runny nose, coughing, or fever), if any, during the prior month. The serum estradiol concentration and salivary SIgA secretion rate were significantly lower for ARs than for ERs (p < 0.05). Serum progesterone concentration was not significantly different between groups. Higher frequencies of headache, runny nose, coughing, and fever were observed in ARs than in ERs. Results show that athletic amenorrhea with low estrogen might accelerate downregulation of mucosal immune function in athletes and enhance susceptibility to infection. PMID:22516912

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

    PubMed Central

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

    2016-01-01

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

  4. Deeper Penetration of Erythrocytes into the Endothelial Glycocalyx Is Associated with Impaired Microvascular Perfusion

    PubMed Central

    Lee, Dae Hyun; Dane, Martijn J. C.; van den Berg, Bernard M.; Boels, Margien G. S.; van Teeffelen, Jurgen W.; de Mutsert, Renée; den Heijer, Martin; Rosendaal, Frits R.; van der Vlag, Johan; van Zonneveld, Anton Jan; Vink, Hans; Rabelink, Ton J.

    2014-01-01

    Changes in endothelial glycocalyx are one of the earliest changes in development of cardiovascular disease. The endothelial glycocalyx is both an important biological modifier of interactions between flowing blood and the vessel wall, and a determinant of organ perfusion. We hypothesize that deeper penetration of erythrocytes into the glycocalyx is associated with reduced microvascular perfusion. The population-based prospective cohort study (the Netherlands Epidemiology of Obesity [NEO] study) includes 6,673 middle-aged individuals (oversampling of overweight and obese individuals). Within this cohort, we have imaged the sublingual microvasculature of 915 participants using sidestream darkfield (SDF) imaging together with a recently developed automated acquisition and analysis approach. Presence of RBC (as a marker of microvascular perfusion) and perfused boundary region (PBR), a marker for endothelial glycocalyx barrier properties for RBC accessibility, were assessed in vessels between 5 and 25 µm RBC column width. A wide range of variability in PBR measurements, with a mean PBR of 2.14 µm (range: 1.43–2.86 µm), was observed. Linear regression analysis showed a marked association between PBR and microvascular perfusion, reflected by RBC filling percentage (regression coefficient β: −0.034; 95% confidence interval: −0.037 to −0.031). We conclude that microvascular beds with a thick (“healthy”) glycocalyx (low PBR), reflects efficient perfusion of the microvascular bed. In contrast, a thin (“risk”) glycocalyx (high PBR) is associated with a less efficient and defective microvascular perfusion. PMID:24816787

  5. Restricted passage of insulin across capillary endothelium in perfused rat adipose tissue

    SciTech Connect

    Chernick, S.S.; Gardiner, R.J.; Scow, R.O. )

    1987-11-01

    Passage of insulin across capillary endothelium was monitored in perfused rat parametrial adipose tissue by the effect of intra-arterially infused insulin on oxidation of (U-{sup 14}C)glucose to CO{sub 2}. Glucose oxidation was constant at 34 nmol C {center dot} g{sup {minus}1} {center dot} min{sup {minus}1} for 90 min in tissues perfused with 0 or 50 {mu}U/ml. The rate of oxidation was doubled in 90 min at 100 {mu}U/ml and maximal in 40 min at 200 {mu}U/ml and in 20-30 min at 500 {mu}U/ml. The slow decline in oxidation rate when insulin infusion was stopped suggested that insulin was sequestered in the tissue. Although half-maximal response to insulin occurred in perfused tissues at 100 {mu}U/ml, it occurred at 8 {mu}U/ml in incubated adipocytes and at 30 {mu}U/ml in incubated tissue. In addition, the time required for maximal response to insulin was longer in perfused adipose tissue than in incubated cells and tissues. The data indicate that the transfer of insulin from blood to parenchymal cells in perfused tissue was restricted. The minimal amount of insulin needed for a response by adipocytes in perfused tissue was estimated at be <1% of that in blood. The findings are consistent with the concept that insulin is transferred across capillary endothelium by a receptor-mediated process.

  6. Perfusion Magnetic Resonance Imaging: A Comprehensive Update on Principles and Techniques

    PubMed Central

    Li, Ka-Loh; Ostergaard, Leif; Calamante, Fernando

    2014-01-01

    Perfusion is a fundamental biological function that refers to the delivery of oxygen and nutrients to tissue by means of blood flow. Perfusion MRI is sensitive to microvasculature and has been applied in a wide variety of clinical applications, including the classification of tumors, identification of stroke regions, and characterization of other diseases. Perfusion MRI techniques are classified with or without using an exogenous contrast agent. Bolus methods, with injections of a contrast agent, provide better sensitivity with higher spatial resolution, and are therefore more widely used in clinical applications. However, arterial spin-labeling methods provide a unique opportunity to measure cerebral blood flow without requiring an exogenous contrast agent and have better accuracy for quantification. Importantly, MRI-based perfusion measurements are minimally invasive overall, and do not use any radiation and radioisotopes. In this review, we describe the principles and techniques of perfusion MRI. This review summarizes comprehensive updated knowledge on the physical principles and techniques of perfusion MRI. PMID:25246817

  7. Computed Tomography Perfusion Assessment of Radiation Therapy Effects on Spinal Cord Hemodynamics

    SciTech Connect

    Spampinato, Maria Vittoria; Bisdas, Sotirios; Sharma, Anand K.; McDonald, Daniel; Strojan, Primoz; Rumboldt, Zoran

    2010-07-01

    Purpose: We used computed tomography (CT) perfusion to evaluate the acute and late effect of radiation therapy (RT) on spinal cord (SC) hemodynamics in patients without symptoms of myelopathy. We hypothesized that SC perfusion could be acutely altered during RT. Methods and Materials: We analyzed neck CT perfusion studies of 36 head-and-neck cancer patients (N1), 16 of whom had previously undergone RT. In a separate group of 6 patients (N2), CT perfusion studies were obtained before RT, after 40 Gy, and after treatment completion. Results: In the N1 group, SC blood flow (BF), blood volume (BV), mean transit time (MTT), and capillary permeability (CP) maps were not significantly different between RT-treated and RT-naive patients. In the N2 group, BF and CP were significantly increased during treatment compared with the baseline and post-RT studies. Conclusions: Radiation therapy of the head and neck may cause transient perturbations of SC perfusion that seem to reverse after treatment. There are no definite chronic effects of RT on SC perfusion observeable at the typical doses administered during treatment of head and neck malignancies.

  8. [Direct and indirect mucosal wave imaging techniques].

    PubMed

    Krasnodębska, Paulina; Szkiełkowska, Agata

    2016-04-01

    The vocal folds play a key role in the process of phonation. Cyclical movements of the vocal folds model a space called glottis, what leads to voice formation. The space contains surface between the vocal folds and the inner surface of the arytenoid cartilages. The best indicator of the vocal folds vibratory function is the mucosal wave. The presence and size of the mucosal wave is widely recognized as an indicator of tension and plasticity of vocal folds. It is also essential in the process of creating a proper, resonant voice. In the article, current knowledge of mucosal wave imaging techniques is given. Imaging can be carried out directly and indirectly. Among the direct methods, the following are distinguished: laryngostroboscopy, laryngovideostroboscopy, videokymography and high-speed digital imaging. Indirect methods include: electroglottography, photoglottography and ultrasonography. PMID:27137829

  9. Novel vaccine development strategies for inducing mucosal immunity

    PubMed Central

    Fujkuyama, Yoshiko; Tokuhara, Daisuke; Kataoka, Kosuke; Gilbert, Rebekah S; McGhee, Jerry R; Yuki, Yoshikazu; Kiyono, Hiroshi; Fujihashi, Kohtaro

    2012-01-01

    To develop protective immune responses against mucosal pathogens, the delivery route and adjuvants for vaccination are important. The host, however, strives to maintain mucosal homeostasis by responding to mucosal antigens with tolerance, instead of immune activation. Thus, induction of mucosal immunity through vaccination is a rather difficult task, and potent mucosal adjuvants, vectors or other special delivery systems are often used, especially in the elderly. By taking advantage of the common mucosal immune system, the targeting of mucosal dendritic cells and microfold epithelial cells may facilitate the induction of effective mucosal immunity. Thus, novel routes of immunization and antigen delivery systems also show great potential for the development of effective and safe mucosal vaccines against various pathogens. The purpose of this review is to introduce several recent approaches to induce mucosal immunity to vaccines, with an emphasis on mucosal tissue targeting, new immunization routes and delivery systems. Defining the mechanisms of mucosal vaccines is as important as their efficacy and safety, and in this article, examples of recent approaches, which will likely accelerate progress in mucosal vaccine development, are discussed. PMID:22380827

  10. Noninvasive testing of cerebral perfusion reserve prior to coronary artery bypass graft surgery

    SciTech Connect

    Levine, R.L.; Lagreze, H.L.; Berkoff, H.A.; Turnipseed, W.D.; Hanson, J.M.; Sunderland, J.J.; Nickles, R.J.; Rowe, B.R.

    1988-05-01

    Cerebral perfusion reserve testing using fluorine-18-fluoromethane and positron emission tomographic brain scanning to define cerebral blood flow abnormalities was performed in 5 patients being considered for combined coronary and carotid reconstructive surgery. Blood flow testing during normocapnia and following hypercapnia was utilized in these patients to determine the hemodynamic significance of known extracranial carotid artery occlusive lesions. Reserve diminution in 2 of these patients prompted combined surgery, whereas normal reserve values in the other 3 prompted coronary surgery alone. Results obtained in this preliminary series show how preoperative noninvasive testing of cerebral perfusion reserve adds to the diagnostic evaluation of patients with widespread vascular disease.

  11. Inhomogeneity of pulmonary perfusion during sustained microgravity on SLS-1.

    PubMed

    Prisk, G K; Guy, H J; Elliott, A R; West, J B

    1994-04-01

    We studied the effects of gravity on the inhomogeneity of pulmonary perfusion in humans by performing hyperventilation-breath-hold single-breath measurements before, during, and after 9 days of continuous exposure to microgravity during the Spacelab Life Sciences-1 (SLS-1) mission. In microgravity the indicators of inhomogeneity of perfusion, especially the size of cardiogenic oscillations in expired CO2 and the height of phase IV, were markedly reduced. Cardiogenic oscillations were reduced to approximately 60% of their preflight standing size, and the height of phase IV was between 0 and -8% (a terminal fall became a small terminal rise) of the preflight standing value. The terminal change in expired CO2 was nearly abolished in microgravity, indicating more uniformity of blood flow between lung units that close and those that remain open at the end of expiration. A possible explanation of this observation is the disappearance of gravity-dependent topographic inequality of blood flow. The residual cardiogenic oscillations in expired CO2 imply a persisting inhomogeneity of perfusion in the absence of gravity, probably in lung regions that are not within the same acinus. PMID:8045853

  12. Inhomogeneity of pulmonary perfusion during sustained microgravity on SLS-1

    NASA Technical Reports Server (NTRS)

    Prisk, G. Kim; Guy, Harold J. B.; Elliott, Ann R.; West, John B.

    1994-01-01

    We studied the effects of gravity on the inhomogeneity of pulmonary perfusion in humans by performing hyperventilation-breath-hold single-breath measurements before, during, and after 9 days of continuous exposure to microgravity during the Spacelab Life Sciences-1 (SLS-1) mission. In microgravity the indicators of inhomogeneity of perfusion, especially the size of cardiogenic oscillations in expired CO2 and the height of phase IV, were markedly reduced. Cardiogenic oscillations were reduced to approximately 60% of their preflight standing size, and the height of phase IV was between 0 and -8% (a terminal fall became a small terminal rise) of the preflight standing value. The terminal change in expired CO2 was nearly abolished in microgravity, indicating more uniformity of blood flow between lung units that close and those that remain open at the end of expiration. A possible explanation of this observation is the disappearance of gravity-dependent topographic inequality of blood flow. The residual cardiogenic oscillations in expired CO2 imply a persisting inhomogeneity of perfusion in the absence of gravity, probably in lung regions that are not within the same acinus.

  13. Mapping resting-state functional connectivity using perfusion MRI

    PubMed Central

    Chuang, Kai-Hsiang; van Gelderen, Peter; Merkle, Hellmut; Bodurka, Jerzy; Ikonomidou, Vasiliki N.; Koretsky, Alan P.; Duyn, Jeff H.; Talagala, S. Lalith

    2008-01-01

    Resting-state, low frequency (< 0.08 Hz) fluctuations of blood oxygenation level dependent (BOLD) magnetic resonance signal have been shown to exhibit high correlation among functionally connected regions. However, correlations of cerebral blood flow (CBF) fluctuations during the resting state have not been extensively studied. The main challenges of using arterial spin labeling perfusion magnetic resonance imaging to detect CBF fluctuations are low sensitivity, low temporal resolution, and contamination from BOLD. This work demonstrates CBF-based quantitative functional connectivity mapping by combining continuous arterial spin labeling (CASL) with a neck labeling coil and a multi-channel receiver coil to achieve high perfusion sensitivity. In order to reduce BOLD contamination, the CBF signal was extracted from the CASL signal time course by high frequency filtering. This processing strategy is compatible with sinc interpolation for reducing the timing mismatch between control and label images and has the flexibility of choosing an optimal filter cutoff frequency to minimize BOLD fluctuations. Most subjects studied showed high CBF correlation in bilateral sensorimotor areas with good suppression of BOLD contamination. Root-mean-square CBF fluctuation contributing to bilateral correlation was estimated to be 29% ± 19% (N = 13) of the baseline perfusion, while BOLD fluctuation was 0.26% ± 0.14% of the mean intensity (at 3T and 12.5 ms echo time). PMID:18314354

  14. MR mapping of temperature and perfusion for hyperthermia therapy

    NASA Astrophysics Data System (ADS)

    Wlodarczyk, Waldemar; Vlad, Julia; Lange, Thomas; Wust, Peter; Felix, Roland

    2001-05-01

    The promising results, recently obtained in phantom experiments employing the MR-based proton resonance frequency (PRF) method as a non-invasive tool for the temperature monitoring of hyperthermia therapy, are not easily reproduced in vivo. One of the reasons is the impact of perfusion changes on the PRF-measured temperature. In our experiments in vivo, heat was supplied on one side of the volunteers knee or pelvis by a rubber hose with circulating warm water (50iC). The PRF method was calibrated by the constant temperature sensitivity of pure water of 0.011 ppm/iC. MR mapping of perfusion changes was based on T2*-weighted tracking of the first-pass kinetics of contrast agent. The hemodynamic parameters of regional blood volume (rBV) and mean transit time (MTT) were extracted by fitting pixel-by-pixel the first- pass kinetics to the gamma-variate model. Special attention was directed to improve a quality of the automatic non-linear fit at low signal-to-noise values. The distributions of PRF- based temperature changes show large areas of apparently high temperature elevations (exceeding 10iC) in regions close to the heat source, and others with just as large temperature decays in more distant regions. Areas of apparently high temperature elevations correlate with areas of blood flow increase and vice versa. In conclusion, the visible heat- induced PRF changes in vivo are primarily perfusion changes, which mask the much smaller true temperature changes.

  15. Oral mucosal diseases: evaluation and management.

    PubMed

    Stoopler, Eric T; Sollecito, Thomas P

    2014-11-01

    Oral mucosal diseases encompass several common conditions that affect the general population. Some of these disorders present with signs and symptoms that are pathognomonic for the condition, whereas others present with similar features that can make clinical diagnosis difficult to achieve. It is important for physicians to have a clear understanding of these disorders to provide appropriate care to patients. This article reviews clinical aspects of common oral mucosal disorders, including candidiasis, herpes simplex viral infections, aphthous stomatitis, lichen planus, pemphigus vulgaris, and mucous membrane pemphigoid. PMID:25443679

  16. Oral mucositis in myelosuppressive cancer therapy.

    PubMed

    Epstein, J B; Schubert, M M

    1999-09-01

    Because the etiology of mucositis is multifactorial , approaches to prevention and management have also been multifactorial. Effective prevention and management of mucositis will reduce the pain and suffering experienced during cancer treatment. Oropharyngeal pain in cancer patients frequently requires systemic analgesics, adjunctive medications, physical therapy, and psychologic therapy in addition to oral care and topical treatments. Good oral hygiene reduces the severity of oral mucositis and does not increase the risk of bacteremia. Current approaches to management include frequent oral rinsing with saline or bicarbonate rinses, maintaining excellent oral hygiene, and using topical anesthetics and analgesics. Cryotherapy is a potential adjunctive approach in some cases. There are a number of approaches that appear to represent viable candidates for further study. Biologic response modifiers offer the potential for prevention and for acceleration of healing. Various cytokines will enter clinical trials in the near future; these offer the potential for reduction of epithelial cell sensitivity to the toxic effects of cancer therapy or for stimulation of repair of the damaged tissue. Other approaches include the use of medications to reduce exposure of the oral mucosa to chemotherapeutic drugs that are secreted in saliva. Antimicrobial approaches have met with conflicting results, little effect being seen with chlorhexidine and systemic antimicrobials in the prevention of mucositis in radiation patients. In patients with BMT and patients with leukemia, chlorhexidine may not be effective in preventing mucositis, although there may be reduction in oral colonization by Candida. Initial studies of topical antimicrobials that affect the gram-negative oral flora have shown reductions in ulcerative mucositis during radiation therapy but have not been assessed in leukemia/BMT. Among other approaches that require further study are low-energy lasers and anti

  17. Duodenal mucosal T cell subpopulation and bacterial cultures in acquired immune deficiency syndrome.

    PubMed

    Budhraja, M; Levendoglu, H; Kocka, F; Mangkornkanok, M; Sherer, R

    1987-05-01

    Enteric infections, chronic diarrhea frequently with no obvious etiology, and weight loss cause major morbidity and mortality in acquired immune deficiency syndrome (AIDS). Alterations in mucosal immunity may explain the increased incidence of enteric infections, and contamination of the upper small intestine with bacteria may be the cause of weight loss observed in these patients. To test this hypothesis we studied the mucosal T lymphocyte subset in duodenal mucosal biopsies in 14 AIDS and seven control patients. Duodenal fluid was also cultured for aerobic and anaerobic bacteria. There was a significant decrease among leu-3a T cells (helper/inducer) subset in AIDS. The proportion of mucosal T cells reacting with leu-2a (cytotoxic/suppressor) was significantly increased in AIDS patients. These patients also had a significant reversal of the normal mucosal helper/suppressor T cell ratio. There was no change in the number of leu-7 cells (cells mediate natural killer and antibody-dependent cellular cytotoxicity) as compared to controls. All patients with diarrhea and three of five patients without diarrhea had bacteria in their duodenal fluid. Mean number of organisms was 4.5 X 10(4)/ml. Cultures were negative in all control subjects. The results reveal that the abnormalities of T cell subpopulation in the blood of AIDS patients also occur in their duodenal mucosa. This immunological abnormality is associated with the bacterial colonization of upper gastrointestinal tract which may explain the diarrhea and weight loss observed in majority of our patients. The results also indicate that increased incidence of enteric infections in AIDS may be explained on the basis of altered mucosal immunity. PMID:2953237

  18. Diurnal Curve of the Ocular Perfusion Pressure

    PubMed Central

    Moreira, TCA; Bezerra, BSP; Vianello, MP; Corradi, J; Dorairaj, SK; Prata, TS

    2016-01-01

    ABSTRACT Purpose: To describe the diurnal variation of the ocular perfusion pressure (OPP) in normal, suspects and glaucoma patients. Materials and methods: Seventy-nine subjects were enrolled in a prospective study. The diurnal curve of intraocular pressure (IOP) was performed and blood pressure measurements were obtained. Each participant was grouped into one of the following based upon the clinical evaluation of the optic disk, IOP and standard achromatic perimetry (SAP): 18 eyes were classified as normal (normal SAP, normal optic disk evaluation and IOP < 21 mm Hg in two different measurements), 30 eyes as glaucoma suspect (GS) (normal SAP and mean deviation (MD), C/D ration > 0.5 or asymmetry > 0.2 and/or ocular hypertension), 31 eyes as early glaucoma (MD < -6 dB, glaucomatous optic neuropathy and SAP and MDs on SAP. Standard achromatic perimetry was performed with the Octopus 3.1.1 Dynamic 24-2 program. Intraocular pressure and blood pressure measurements were taken at 6 am, 9 am, 12, 3 and 6 pm. The patients stayed in the seated position for 5 minutes prior to blood pressure measurements. Results: The mean IOP values in all groups did not follow any regular pattern. The peak IOP was found to be greater in suspect [18.70 ± 3.31 (mm Hg ± SD)] and glaucoma (18.77 ± 4.30 mm Hg) patients as compared to normal subjects (16.11 ± 2.27 mm Hg). In studying the diurnal variation of the OPP, we found lower values at 3 pm in normals (34.21 ± 2.07 mm Hg), at 9 am in suspects (54.35 ± 3.32 mm Hg) and at 12 pm in glaucoma patients (34.84 ± 1.44 mm Hg). Conclusion: Each group has a specific OPP variation during the day with the most homogeneous group being the suspect one. It is important to keep studying the IOP and OPP variation for increased comprehension of the pathophysiology of glaucomatous optic neuropathy. How to cite this article: Kanadani FN, Moreira TCA, Bezerra BSP, Vianello MP, Corradi J, Dorairaj SK, Prata TS. Diurnal Curve of the Ocular Perfusion

  19. New Trends in Radionuclide Myocardial Perfusion Imaging

    PubMed Central

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

    2016-01-01

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

  20. {sup 99m}Tc radiopharmaceuticals for brain perfusion imaging

    SciTech Connect

    Deutsch, E.; Volkert, W.A.

    1991-12-31

    It is well established that small, neutral, lipophilic technetium complexes can diffuse into the brain and then be trapped intracellularly by a variety of mechanisms. A more detailed understanding of the structural and chemical parameters which promote efficient diffusion into the brain, and which underlie the trapping mechanisms, will be necessary to delineate the clinical relevance of current agents, and to design improved technetium 99 pharmaceuticals. Current technetium 99 brain-perfusion imaging agents do not show ideal characteristics of brain uptake and retention. Furthermore, significant fractions of the technetium 99 complexes are lost between site of injection and the brain. Thus, it is difficult to use these current agents to quantitate regional cerebral blood flow. Nevertheless, these agents are proving extremely valuable for the SPECT evaluation of abnormalities in brain perfusion patients with neurological disorders.

  1. Scalable Approach for Extrusion and Perfusion of Tubular, Heterotypic Biomaterials

    NASA Astrophysics Data System (ADS)

    Jeronimo, Mark David

    Soft material tubes are critical in the vasculature of mammalian tissues, forming networks of blood vessels and airways. Homogeneous and heterogeneous hydrogel tubes were extruded in a one-step process using a three layer microfluidic device. Co-axial cylindrical flow of crosslinking solutions and an alginate matrix is generated by a radial arrangement of microfluidic channels at the device's vertical extrusion outlet. The flow is confined and begins a sol-gel transition immediately as it extrudes at velocities upwards of 4 mm/s. This approach allows for predictive control over the dimensions of the rapidly formed tubular structures for outer diameters from 600 microm to 3 mm. A second microfluidic device hosts tube segments for controlled perfusion and pressurization using a reversible vacuum seal. On-chip tube deflection is observed and modeled as a measure of material compliance and circumferential elasticity. I anticipate applications of these devices for perfusion cell culture of cell-laden hydrogel tubes.

  2. Cardiac PET Perfusion: Prognosis, Risk Stratification, Clinical Management

    PubMed Central

    Dorbala, Sharmila; Di Carli, Marcelo F.

    2014-01-01

    Myocardial perfusion imaging (MPI) with positron emission tomography (PET) has expanded significantly over the past decade. With the wider availability of PET scanners and the routine use of quantitative blood flow imaging, the clinical use of PET MPI is expected to increase further. PET MPI is a powerful tool to identify risk, to quantify risk, and to guide therapy in patients with known or suspected coronary artery disease (CAD). A large body of evidence supports the prognostic value of PET MPI and ejection fraction in intermediate to high risk subjects, in women, in obese individuals and in post coronary artery bypass grafting (CABG) individuals. A normal perfusion study indicates low risk (< 1% annualized rate of cardiac events of cardiac death and non-fatal myocardial infarction), while an abnormal study indicates high risk. With accurate risk stratification, high quality images, and quantitation PET MPI may transform the management of patients with known or suspected CAD. PMID:25234079

  3. Plasma Cell Mucositis of Oro- and Hypopharynx: A Case Report

    PubMed Central

    Puvanendran, Mark; Lieder, Anja; Issing, Wolfgang

    2012-01-01

    Objective. To raise awareness of plasma cell mucositis as a rare differential diagnosis for oral mucosal ulceration and its macroscopic similarity to malignancy. Method. We report a patient who presented with oral features suggestive of malignancy. A biopsy revealed plasma cell mucositis. Results. The patient successfully had a full excision of one lesion and a spontaneous resolution of the other. Conclusion. With the increasing incidence of oral mucosal pathology, physicians should be aware of this differential diagnosis. PMID:22953106

  4. Inosculation and perfusion of pre-vascularized tissue patches containing aligned human microvessels after myocardial infarction.

    PubMed

    Riemenschneider, Sonja B; Mattia, Donald J; Wendel, Jacqueline S; Schaefer, Jeremy A; Ye, Lei; Guzman, Pilar A; Tranquillo, Robert T

    2016-08-01

    A major goal of tissue engineering is the creation of pre-vascularized tissues that have a high density of organized microvessels that can be rapidly perfused following implantation. This is especially critical for highly metabolic tissues like myocardium, where a thick myocardial engineered tissue would require rapid perfusion within the first several days to survive transplantation. In the present work, tissue patches containing human microvessels that were either randomly oriented or aligned were placed acutely on rat hearts post-infarction and for each case it was determined whether rapid inosculation could occur and perfusion of the patch could be maintained for 6 days in an infarct environment. Patches containing self-assembled microvessels were formed by co-entrapment of human blood outgrowth endothelial cells and human pericytes in fibrin gel. Cell-induced gel contraction was mechanically-constrained resulting in samples with high densities of microvessels that were either randomly oriented (with 420 ± 140 lumens/mm(2)) or uniaxially aligned (with 940 ± 240 lumens/mm(2)) at the time of implantation. These patches were sutured onto the epicardial surface of the hearts of athymic rats following permanent ligation of the left anterior descending artery. In both aligned and randomly oriented microvessel patches, inosculation occurred and perfusion of the transplanted human microvessels was maintained, proving the in vivo vascularization potential of these engineered tissues. No difference was found in the number of human microvessels that were perfused in the randomly oriented (111 ± 75 perfused lumens/mm(2)) and aligned (173 ± 97 perfused lumens/mm(2)) patches. Our results demonstrate that tissue patches containing a high density of either aligned or randomly oriented human pre-formed microvessels achieve rapid perfusion in the myocardial infarct environment - a necessary first-step toward the creation of a thick, perfusable heart patch. PMID

  5. The imaging of myocardial perfusion with 81mKr during coronary arteriography.

    PubMed

    Kleynhans, P H; Lötter, M G; van Aswegen, A; Herbst, C P; Marx, J D; Minnaar, P C

    1982-01-01

    The use of 81mKr was investigated for imaging myocardial perfusion during coronary arteriography using conventional catheters. When the significance of stenosis judged by arteriography is unclear, the effect on tissue perfusion can be established and the contribution to collateral flow by each artery separately evaluated. The distribution of 81mKr, due to its 13-s half-life, represents regional blood flow. In order to evaluate interventions, studies can be repeated at a low radiation risk to patients. A sterile pyrogen-free 81Rb-81Kr generator was developed. With slow infusion, inadequate mixing and streaming takes place due to laminar flow in coronary arteries. Fast intermittent 3-ml 81Kr-dextrose bolus injections convincingly eliminated streaming artefacts. Imaging was performed in 13 patients with a mobile scintillation camera and digital imaging system. Blood flow was calculated using the inert gas washout technique. There was good correlation (r = 0.91) between coronary blood flow determinations using 81mKr and 133Xe respectively. The perfusion images correlated well with the coronary angiograms. Total coronary arterial occlusions as demonstrated by arteriography were all shown as perfusion defects during rest. During atrial pacing myocardial flow was increased two-fold in normal coronary arteries and to a lesser extent in arteries with significant disease. The most critical lesion in a branch of a left coronary artery leads to a redistribution of perfusion during pacing. PMID:7128629

  6. The effect of the non-steroidal anti-inflammatory drug choline magnesium trisalicylate on gastric mucosal cell exfoliation.

    PubMed

    Mitchell, K G; Hearns, J; Crean, G P

    1984-01-01

    Gastric mucosal cell exfoliation was measured in 10 normal subjects taking choline magnesium trisalicylate (CMT), aspirin and placebo. Both drugs resulted in significantly elevated rates of exfoliation although the serum salicylate levels achieved with aspirin were lower than those achieved by CMT. Side-effects of tinnitus, nausea and increased faecal blood loss were more common while subjects were taking CMT. PMID:6691886

  7. Vasomotor tone does not affect perfusion heterogeneity and gas exchange in normal primate lungs during normoxia

    NASA Technical Reports Server (NTRS)

    Glenny, R. W.; Robertson, H. T.; Hlastala, M. P.

    2000-01-01

    To determine whether vasoregulation is an important cause of pulmonary perfusion heterogeneity, we measured regional blood flow and gas exchange before and after giving prostacyclin (PGI(2)) to baboons. Four animals were anesthetized with ketamine and mechanically ventilated. Fluorescent microspheres were used to mark regional perfusion before and after PGI(2) infusion. The lungs were subsequently excised, dried inflated, and diced into approximately 2-cm(3) pieces (n = 1,208-1,629 per animal) with the spatial coordinates recorded for each piece. Blood flow to each piece was determined for each condition from the fluorescent signals. Blood flow heterogeneity did not change with PGI(2) infusion. Two other measures of spatial blood flow distribution, the fractal dimension and the spatial correlation, did not change with PGI(2) infusion. Alveolar-arterial O(2) differences did not change with PGI(2) infusion. We conclude that, in normal primate lungs during normoxia, vasomotor tone is not a significant cause of perfusion heterogeneity. Despite the heterogeneous distribution of blood flow, active regulation of regional perfusion is not required for efficient gas exchange.

  8. Mechanisms of Neonatal Mucosal Antibody Protection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Following an abrupt transition at birth from the sterile uterus to an environment with abundant commensal and pathogenic microbes, neonatal mammals are protected by maternal antibodies at mucosal surfaces. We show in mice that different antibody isotypes work in distinct ways to protect the neonatal...

  9. New frontiers in mucosal health in aquaculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The dramatic decline in sequencing costs brought about by a shift in the last 5-10 years to massively parallel sequencing platforms has far-reaching consequences for the study of mucosal health in aquaculture. Transcriptome sequencing and gene expression profiling (RNA-seq) offer a rapid approach t...

  10. CpG DNA as mucosal adjuvant.

    PubMed

    McCluskie, M J; Davis, H L

    1999-09-01

    We have previously found synthetic oligodeoxynucleotides (ODN) containing immunostimulatory CpG motifs to be a potent adjuvant to protein administered by intramuscular injection or intranasal inhalation to BALB/c mice. Herein we have further evaluated the potential of CpG ODN as a mucosal adjuvant to purified hepatitis B surface antigen (HBsAg) when administered alone or with cholera toxin (CT). CpG ODN and CT both augmented systemic (humoral and cellular) and mucosal immune responses against HBsAg, and these could be further enhanced with higher doses of adjuvant or boosting. Overall, antibody isotypes with CT alone were predominantly IgG1 (Th2-like) whereas they were predominantly IgG2a (Th1-like) with CpG ODN alone or in combination with CT. Results from this study indicate that stimulatory CpG ODN are promising new adjuvants for mucosal vaccination strategies, whether used alone or in combination with other mucosal adjuvants. PMID:10506647

  11. Pancreatic blood flow in experimental acute pancreatitis

    SciTech Connect

    Berry, A.R.; Millar, A.M.; Taylor, T.V.

    1982-05-01

    The etiology and pathogenesis of acute necrotizing hemorrhagic pancreatitis remain controversial. Recent work has suggested that an early fall in pancreatic blood flow, causing ischemia, may be the initiating factor. Using an established rat model of hemorrhagic pancreatitis and the fractional indicator distribution technique with /sup 86/RbCl, pancreatic blood flow and tissue perfusion have been measured at various times in the condition. Six groups of ten rats were studied: control sham operation and pancreatitis groups were sacrificed at 1, 6, and 24 hr. Pancreatic blood flow (% of cardiac output) and perfusion (blood flow/g tissue) were measured. Blood flow was increased by a maximum of 53% at 1 hr (P less than 0.001) and remained elevated for 24 hr, and perfusion was increased by a maximum of 70% (P less than 0.001) at 1 hr and remained elevated at 6 hr. Pancreatic perfusion declines after 6 hr due to increasing gland edema. The results demonstrate a significant increase in pancreatic blood flow and perfusion in experimentally induced acute pancreatitis, suggesting a primary inflammatory response, and refute the ischemic etiological theory.

  12. Mucosal vaccines: non toxic derivatives of LT and CT as mucosal adjuvants.

    PubMed

    Pizza, M; Giuliani, M M; Fontana, M R; Monaci, E; Douce, G; Dougan, G; Mills, K H; Rappuoli, R; Del Giudice, G

    2001-03-21

    Most vaccines are still delivered by injection. Mucosal vaccination would increase compliance and decrease the risk of spread of infectious diseases due to contaminated syringes. However, most vaccines are unable to induce immune responses when administered mucosally, and require the use of strong adjuvant on effective delivery systems. Cholera toxin (CT) and Escherichia coli enterotoxin (LT) are powerful mucosal adjuvants when co-administered with soluble antigens. However, their use in humans is hampered by their extremely high toxicity. During the past few years, site-directed mutagenesis has permitted the generation of LT and CT mutants fully non toxic or with dramatically reduced toxicity, which still retain their strong adjuvanticity at the mucosal level. Among these mutants, are LTK63 (serine-to-lysine substitution at position 63 in the A subunit) and LTR72 (alanine-to-arginine substitution at position 72 in the A subunit). The first is fully non toxic, whereas the latter retains some residual enzymatic activity. Both of them are extremely active as mucosal adjuvants, being able to induce very high titers of antibodies specific for the antigen with which they are co-administered. Both mutants have now been tested as mucosal adjuvants in different animal species using a wide variety of antigens. Interestingly, mucosal delivery (nasal or oral) of antigens together with LTK63 or LTR72 mutants also conferred protection against challenge in appropriate animal models (e.g. tetanus, Helicobacter pylori, pertussis, pneumococci, influenza, etc). In conclusion, these LTK63 and LTR72 mutants are safe adjuvants to enhance the immunogenicity of vaccines at the mucosal level, and will be tested soon in humans. PMID:11257389

  13. Ex vivo lung graft perfusion.

    PubMed

    Briot, Raphaël; Gennai, Stéphane; Maignan, Maxime; Souilamas, Redha; Pison, Christophe

    2016-04-01

    This review proposes an update of the state of the art and the ongoing clinical trials of ex vivo lung perfusion for lung transplantation in patients. Ex vivo lung perfusion techniques (EVLP) can be used to evaluate a lung graft outside of the body. The goal of EVLP is to study the functional status of lung grafts that were first rejected for transplantation because they did not match all criteria for a conventional transplantation. After an EVLP evaluation, some of these lungs may be requalified for a possible transplantation in patients. This article proposes an overview of the developments of EVLP techniques. During EVLP, the perfusion and ventilation of the isolated lung preparation are very progressive in order to avoid oedema due to ischaemia-reperfusion injuries. Lung evaluation is mainly based on gasometric (PaO2/FiO2) and rheological criteria (low pulmonary arterial resistance). Several series of patients transplanted with EVLP evaluated lungs have been recently published with promising results. EVLP preparations also allow a better understanding of the physiopathology and treatments of ischaemia-reperfusion injuries. Organ procurements from "non-heart-beating" donors will probably require a wider application of these ex vivo techniques. The development of semi-automated systems might facilitate the clinical use of EVLP techniques. PMID:26746565

  14. Effects of lung ventilation–perfusion and muscle metabolism–perfusion heterogeneities on maximal O2 transport and utilization

    PubMed Central

    Cano, I; Roca, J; Wagner, P D

    2015-01-01

    Previous models of O2 transport and utilization in health considered diffusive exchange of O2 in lung and muscle, but, reasonably, neglected functional heterogeneities in these tissues. However, in disease, disregarding such heterogeneities would not be justified. Here, pulmonary ventilation–perfusion and skeletal muscle metabolism–perfusion mismatching were added to a prior model of only diffusive exchange. Previously ignored O2 exchange in non-exercising tissues was also included. We simulated maximal exercise in (a) healthy subjects at sea level and altitude, and (b) COPD patients at sea level, to assess the separate and combined effects of pulmonary and peripheral functional heterogeneities on overall muscle O2 uptake ( and on mitochondrial (). In healthy subjects at maximal exercise, the combined effects of pulmonary and peripheral heterogeneities reduced arterial () at sea level by 32 mmHg, but muscle by only 122 ml min−1 (–3.5%). At the altitude of Mt Everest, lung and tissue heterogeneity together reduced by less than 1 mmHg and by 32 ml min−1 (–2.4%). Skeletal muscle heterogeneity led to a wide range of potential among muscle regions, a range that becomes narrower as increases, and in regions with a low ratio of metabolic capacity to blood flow, can exceed that of mixed muscle venous blood. For patients with severe COPD, peak was insensitive to substantial changes in the mitochondrial characteristics for O2 consumption or the extent of muscle heterogeneity. This integrative computational model of O2 transport and utilization offers the potential for estimating profiles of both in health and in diseases such as COPD if the extent for both lung ventilation–perfusion and tissue metabolism–perfusion heterogeneity is known. PMID:25640017

  15. Management of Mucositis During Chemotherapy: From Pathophysiology to Pragmatic Therapeutics.

    PubMed

    Van Sebille, Ysabella Z A; Stansborough, Romany; Wardill, Hannah R; Bateman, Emma; Gibson, Rachel J; Keefe, Dorothy M

    2015-11-01

    Chemotherapy-induced mucositis is a common condition caused by the breakdown of the mucosal barrier. Symptoms can include pain, vomiting and diarrhoea, which can often necessitate chemotherapy treatment breaks or dose reductions, thus compromising survival outcomes. Despite the significant impact of mucositis, there are currently limited clinically effective pharmacological therapies for the pathology. New emerging areas of research have been proposed to play key roles in the development of mucositis, providing rationale for potential new therapeutics for the prevention, treatment or management of chemotherapy-induced mucositis. This review aims to address these new areas of research and to comment on the therapeutics arising from them. PMID:26384312

  16. Simultaneous Noninvasive Determination of Regional Myocardial Perfusion and Oxygen Content in Rabbits: Toward Direct Measurement of Myocardial Oxygen Consumption at MR Imaging1

    PubMed Central

    Reeder, Scott B.; Holmes, A. Alexander; McVeigh, Elliot R.; Forder, John R.

    2007-01-01

    PURPOSE To determine whether myocardial arterial perfusion and oxygen concentration can be quantified simultaneously from the same images by using spin labeling and the blood oxygenation level-dependent (BOLD) effect with fast spin-echo (SE) imaging. MATERIALS AND METHODS A T2-weighted fast SE pulse sequence was written to image isolated, arrested, blood-perfused rabbit hearts (n = 6) at 4.7 T. Perfusion images with intensity in units of milliliters per minute per gram that covered the entire left ventricle with 0.39 × 0.39 × 3.00-mm resolution were obtained in less than 15 minutes with a 32-fold reduction in imaging time from that of a previous study. Estimates of oxygen concentration were made from the same images acquired for calculation of perfusion images. RESULTS Estimates of regional myocardial oxygen content could be made from the perfusion images; this demonstrated the feasibility of three-dimensional calculation of regional oxygen consumption, which requires concomitant measurement of both oxygen content and flow. Fast SE imaging was shown to bas sensitive to hemoglobin desaturation as standard SE imaging. Perfusion abnormalities and oxygen deficits were easily identified and verified qualitatively with gadopentetate dimeglumine on both perfusion and BOLD images obtained after coronary arterial ligation. CONCLUSION T2-weighted fast SE imaging combined with perfusion-sensitive spin labeling can be used to measure myocardial arterial perfusion and oxygen concentration. This provides the groundwork for calculation of regional myocardial oxygen consumption. PMID:10478241

  17. Effects of estradiol on uterine perfusion in anesthetized cyclic mares affected with uterine vascular elastosis.

    PubMed

    Esteller-Vico, A; Liu, I K M; Vaughan, B; Steffey, E P; Brosnan, R J

    2016-01-01

    Uterine vascular elastosis in mares is characterized by degeneration of uterine vasculature through thickening of the elastin layers. Factors commonly associated with this degeneration include age, parity, and chronic uterine endometritis. Affected mares have also been shown to exhibit decreases in uterine blood flow and perfusion of the uterus. Due to the increased thickness of the elastin layers, we hypothesize that vasodilatation of the uterine vasculature is also impaired. To test the functionality of these vessels, we evaluated the vasodilatory effects of estradiol on the uterine vascular bed in mares with normal vasculature and mares with severe elastosis. Both groups were tested in estrus and diestrus. Fluorescent microspheres were used to determine basal blood perfusion, followed by the intravenous administration of 1.0 μg/kg of 17β-estradiol. After 90 min, perfusion was measured once again to determine the vascular response to estradiol. Control mares in estrus displayed a significant increase in total uterine blood flow after the administration of estradiol when compared to baseline levels. No other group had a significant increase in total blood flow and perfusion after estradiol administration. The administration of estradiol in control mares induced regional increases in perfusion in the uterine horns and uterine body during estrus and only in the uterine horns during diestrus. Mares affected by elastosis exhibited no regional differences in perfusion levels post-estradiol administration. The difference in the vasodilatory response induced by estradiol between reproductively healthy mares and mares affected with elastosis indicates that the functionality of the affected vessels is compromised. PMID:26642749

  18. Ectopic Osteogenesis of Macroscopic Tissue Constructs Assembled from Human Mesenchymal Stem Cell-Laden Microcarriers through In Vitro Perfusion Culture

    PubMed Central

    Chen, Maiqin; Zhou, Min; Ye, Zhaoyang; Zhou, Yan; Tan, Wen-Song

    2014-01-01

    We had previously demonstrated the feasibility of preparing a centimeter-sized bone tissue construct by following a modular approach. In the present study, the objectives were to evaluate osteogenesis and tissue formation of human amniotic mesenchymal stem cells-laden CultiSpher S microcarriers during in vitro perfusion culture and after subcutaneous implantation. Microtissues were prepared in dynamic culture using spinner flasks in 28 days. In comparison with 1-week perfusion culture, microtissues became more obviously fused, demonstrating significantly higher cellularity, metabolic activity, ALP activity and calcium content while maintaining cell viability after 2-week perfusion. After subcutaneous implantation in nude mice for 6 and 12 weeks, all explants showed tight contexture, suggesting profound tissue remodeling in vivo. In addition, 12-week implantation resulted in slightly better tissue properties. However, in vitro perfusion culture time exerted great influence on the properties of corresponding explants. Degradation of microcarriers was more pronounced in the explants of 2-week perfused macrotissues compared to those of 1-week perfusion and directly implanted microtissues. Moreover, more blood vessel infiltration and bone matrix deposition with homogeneous spatial distribution were found in the explants of 2-week perfused macrotissues. Taken together, in vitro perfusion culture time is critical in engineering bone tissue replacements using such a modular approach, which holds great promise for bone regeneration. PMID:25275528

  19. Estimating a regional ventilation-perfusion index

    PubMed Central

    Muller, P A; Li, T; Isaacson, D; Newell, J C; Saulnier, G J; Kao, Tzu-Jen; Ashe, Jeffrey

    2015-01-01

    This is a methods paper, where an approximation to the local ventilation-perfusion ratio is derived. This approximation, called the ventilation-perfusion index since it is not exactly the physiological ventilation-perfusion ratio, is calculated using conductivity reconstructions obtained using electrical impedance tomography. Since computation of the ventilation-perfusion index only requires knowledge of the internal conductivity, any conductivity reconstruction method may be used. The method is explained, and results are presented using conductivities obtained from two EIT systems, one using an iterative method and the other a linearization method. PMID:26006279

  20. Uterine perfusion model for analyzing barriers to transport in fibroids.

    PubMed

    Stirland, Darren L; Nichols, Joseph W; Jarboe, Elke; Adelman, Marisa; Dassel, Mark; Janát-Amsbury, Margit-Maria; Bae, You Han

    2015-09-28

    This project uses an ex vivo human perfusion model for studying transport in benign, fibrous tumors. The uterine arteries were cannulated to perfuse the organ with a buffer solution containing blood vessel stain and methylene blue to analyze intratumoral transport. Gross examination revealed tissue expansion effects and a visual lack of methylene blue in the fibroids. Some fibroids exhibited regions with partial methylene blue penetration into the tumor environment. Histological analysis comparing representative sections of fibroids and normal myometrium showed a smaller number of vessels with decreased diameters within the fibroid. Imaging of fluorescently stained vessels exposed a stark contrast between fluorescence within the myometrium and relatively little within the fibroid tissues. Imaging at higher magnification revealed that fibroid blood vessels were indeed perfused and stained with the lipophilic membrane dye; however, the vessels were only the size of small capillaries and the blood vessel coverage was only 12% that of the normal myometrium. The majority of sampled fibroids had a strong negative correlation (Pearson's r=-0.68 or beyond) between collagen and methylene blue staining. As methylene blue was able to passively diffuse into fibroid tissue, the true barrier to transport in these fibroids is likely high interstitial fluid pressure, correlating with high collagen content and solid stress observed in the fibroid tissue. Fibroids had an average elevated interstitial fluid pressure of 4mmHg compared to -1mmHg in normal myometrium. Our findings signify relationships between drug distribution in fibroids and between vasculature characteristics, collagen levels, and interstitial fluid pressure. Understanding these barriers to transport can lead to developments in drug delivery for the treatment of uterine fibroids and tumors of similar composition. PMID:26184049

  1. Effects of some anesthetic agents on skin microcirculation evaluated by laser Doppler perfusion imaging in mice

    PubMed Central

    2013-01-01

    Background Anesthetic agents alter microcirculation, influencing tissue oxygenation and delivery of vital substrates. Laser Doppler perfusion imaging is a widespread technique in the field of microvascular research that can evaluate noninvasively and in real time the effects of environmental conditions, physical manipulations, diseases and treatments on peripheral perfusion. This study aims to evaluate laser Doppler perfusion imaging as a means to detect changes in skin microcirculation induced by some popular anesthetic agents in a murine model. Twenty-four age- and gender-matched healthy CD1 mice were examined by laser Doppler perfusion imaging. The skin microcirculatory response was measured at the level of plantar surfaces during isoflurane anesthesia with or without subsequent dexmedetomidine or acepromazine. At the end of the procedure, dexmedetomidine was reversed by atipamezole administration. Results In all mice, skin blood flow under isoflurane anesthesia did not show significant differences over time (P = 0.1). The serial perfusion pattern and values following acepromazine or dexmedetomidine administration differed significantly (P < 0.05). Conclusions We standardized a reliable laser Doppler perfusion imaging protocol to non-invasively assess changes in skin microcirculation induced by anesthesia in mice, considering the advantages and drawbacks of this technique and its translational value. PMID:24341447

  2. Evaluation of pulmonary perfusion in lung regions showing isolated xenon-133 ventilation washout defects

    SciTech Connect

    Bushnell, D.L.; Sood, K.B.; Shirazi, P.; Pal, I. )

    1990-08-01

    Xenon-133 washout phase imaging is often used to help determine whether the etiology of a perfusion defect is embolic or due to pulmonary parenchymal pathology, such as chronic obstructive pulmonary disease. This study was designed to evaluate the pulmonary blood flow patterns associated with isolated defects on xenon washout images. Scintigraphic lung studies were reviewed until 100 cases with abnormal ventilation results were obtained. Ventilation abnormalities were compared with the corresponding perfusion scan results at the same anatomic site. Of the 208 individual lung regions with xenon abnormalities, 111 showed isolated washout defects (that is, with normal washin). Ninety-four of these 111 sites showed either normal perfusion or a small, nonsegmental corresponding perfusion defect. Three segmental perfusion defects were noted in association with isolated xenon retention. In each of these cases, however, the patient was felt actually to have pulmonary embolism. Thus, it is recommended that, for interpretation of scintigraphic images in the assessment of pulmonary embolism, lung pathology associated with isolated xenon retention not be considered a potential cause for large or segmental perfusion defects.

  3. Surface fluorescence studies of tissue mitochondrial redox state in isolated perfused rat lungs.

    PubMed

    Staniszewski, Kevin; Audi, Said H; Sepehr, Reyhaneh; Jacobs, Elizabeth R; Ranji, Mahsa

    2013-04-01

    We designed a fiber-optic-based optoelectronic fluorometer to measure emitted fluorescence from the auto-fluorescent electron carriers NADH and FAD of the mitochondrial electron transport chain (ETC). The ratio of NADH to FAD is called the redox ratio (RR = NADH/FAD) and is an indicator of the oxidoreductive state of tissue. We evaluated the fluorometer by measuring the fluorescence intensities of NADH and FAD at the surface of isolated, perfused rat lungs. Alterations of lung mitochondrial metabolic state were achieved by the addition of rotenone (complex I inhibitor), potassium cyanide (KCN, complex IV inhibitor) and/or pentachlorophenol (PCP, uncoupler) into the perfusate recirculating through the lung. Rotenone- or KCN-containing perfusate increased RR by 21 and 30%, respectively. In contrast, PCP-containing perfusate decreased RR by 27%. These changes are consistent with the established effects of rotenone, KCN, and PCP on the redox status of the ETC. Addition of blood to perfusate quenched NADH and FAD signal, but had no effect on RR. This study demonstrates the capacity of fluorometry to detect a change in mitochondrial redox state in isolated perfused lungs, and suggests the potential of fluorometry for use in in vivo experiments to extract a sensitive measure of lung tissue health in real-time. PMID:23238793

  4. Acute changes in liver tumour perfusion measured non-invasively with arterial spin labelling

    PubMed Central

    Johnson, S Peter; Ramasawmy, Rajiv; Campbell-Washburn, Adrienne E; Wells, Jack A; Robson, Mathew; Rajkumar, Vineeth; Lythgoe, Mark F; Pedley, R Barbara; Walker-Samuel, Simon

    2016-01-01

    Background: Non-invasive measures of tumour vascular perfusion are desirable, in order to assess response to vascular targeting (or modifying) therapies. In this study, hepatic arterial spin labelling (ASL) magnetic resonance imaging (MRI) was investigated to measure acute changes in perfusion of colorectal cancer in the liver, in response to vascular disruption therapy with OXi4503. Methods: SW1222 and LS174T tumours were established in the liver of MF1 nu/nu mice via intrasplenic injection. Perfusion and R2* MRI measurements were acquired with an Agilent 9.4T horizontal bore scanner, before and at 90 min after 40 mg kg−1 OXi4503. Results: A significant decrease in SW1222 tumour perfusion was observed (−43±33%, P<0.005). LS174T tumours had a significantly lower baseline level of perfusion. Intrinsic susceptibility MRI showed a significant increase in R2* in LS174T tumours (28±25%, P<0.05). An association was found between the change in tumour perfusion and the proximity to large vessels, with pre-treatment blood flow predictive of subsequent response. Histological evaluation confirmed the onset of necrosis and evidence of heterogeneous response between tumour deposits. Conclusions: Hepatic ASL-MRI can detect acute response to targeted tumour vascular disruption entirely non-invasively. Hepatic ASL of liver tumours has potential for use in a clinical setting. PMID:27031853

  5. The effect of transdermal nicotine on digital perfusion in reformed habitual smokers.

    PubMed

    Fulcher, S M; Koman, L A; Smith, B P; Holden, M; Smith, T L

    1998-09-01

    The effects of transdermal nicotine-assisted smoking cessation on digital perfusion and health-related quality of life were assessed in 10 chronic smokers. Components of digital blood flow were evaluated by digital temperature and laser Doppler fluxmetry before, during, and after a standardized cold challenge. Nutritional flow was measured by vital capillaroscopy; a quantitative perfusion profile was obtained by laser Doppler perfusion imaging. A battery of validated measures were used to evaluate health-related quality of life. The microvascular response of smokers was evaluated before smoking cessation and at 2 and 7 days after smoking cessation and was compared with the response of nonsmoking controls. Results demonstrated that a (1) cutaneous microvascular perfusion was lower in smokers than nonsmokers, (2) the acute administration of transdermal nicotine did not decrease cutaneous perfusion, (3) smoking cessation and transdermal nicotine normalized digital microvascular perfusion by 7 days, and (4) transdermal nicotine and smoking cessation did not negatively impact health-related quality of life. PMID:9763251

  6. EFFECT OF VENTILATION AND PERFUSION IMBALANCE ON INERT GAS REBREATHING VARIABLES

    EPA Science Inventory

    The effects of ventilation-to-perfusion (Va/Qc) maldistribution within the lungs on measured multiple gas rebreathing variables were studied in 14 dogs. The rebreathing method (using He, C18C, and C2H2) allows for measurements of pulmonary capillary blood flow (Qc), diffusing cap...

  7. Acute effect of a high nitrate diet on brain perfusion in older adults

    PubMed Central

    Presley, Tennille D.; Morgan, Ashley R.; Bechtold, Erika; Clodfelter, William; Dove, Robin W.; Jennings, Janine M.; Kraft, Robert A.; King, S. Bruce; Laurienti, Paul J.; Rejeski, W. Jack; Burdette, Jonathan H.; Kim-Shapiro, Daniel B.; Miller, Gary D.

    2010-01-01

    Aims Poor blood flow and hypoxia/ischemia contribute to many disease states and may also be a factor in the decline of physical and cognitive function in aging. Nitrite has been discovered to be a vasodilator that is preferentially harnessed in hypoxia. Thus, both infused and inhaled nitrite are being studied as therapeutic agents for a variety of diseases. In addition, nitrite derived from nitrate in the diet has been shown to decrease blood pressure and improve exercise performance. Thus, dietary nitrate may also be important when increased blood flow in hypoxic or ischemic areas is indicated. These conditions could include age-associated dementia and cognitive decline. The goal of this study was to determine if dietary nitrate would increase cerebral blood flow in older adults. Methods and Results In this investigation we administered a high vs. low nitrate diet to older adults (74.7 ± 6.9 years) and measured cerebral perfusion using arterial spin labeling magnetic resonance imaging. We found that the high nitrate diet did not alter global cerebral perfusion, but did lead to increased regional cerebral perfusion in frontal lobe white matter, especially between the dorsolateral prefrontal cortex and anterior cingulate cortex. Conclusion These results suggest that dietary nitrate may be useful in improving regional brain perfusion in older adults in critical brain areas known to be involved in executive functioning. PMID:20951824

  8. Mucosal immunity: its role in defense and allergy.

    PubMed

    Tlaskalová-Hogenová, Helena; Tucková, Ludmila; Lodinová-Zádniková, Rája; Stepánková, Renata; Cukrowska, Bozena; Funda, David P; Striz, Ilja; Kozáková, Hana; Trebichavský, Ilja; Sokol, Dan; Reháková, Zuzana; Sinkora, Jirí; Fundová, Petra; Horáková, Dana; Jelínková, Lenka; Sánchez, Daniel

    2002-06-01

    The interface between the organism and the outside world, which is the site of exchange of nutrients, export of products and waste components, must be selectively permeable and at the same time, it must constitute a barrier equipped with local defense mechanisms against environmental threats (e.g. invading pathogens). The boundaries with the environment (mucosal and skin surfaces) are therefore covered with special epithelial layers which support this barrier function. The immune system, associated with mucosal surfaces covering the largest area of the body (200-300 m(2)), evolved mechanisms discriminating between harmless antigens and commensal microorganisms and dangerous pathogens. The innate mucosal immune system, represented by epithelial and other mucosal cells and their products, is able to recognize the conserved pathogenic patterns on microbes by pattern recognition receptors such as Toll-like receptors, CD14 and others. As documented in experimental gnotobiotic models, highly protective colonization of mucosal surfaces by commensals has an important stimulatory effect on postnatal development of immune responses, metabolic processes (e.g. nutrition) and other host activities; these local and systemic immune responses are later replaced by inhibition, i.e. by induction of mucosal (oral) tolerance. Characteristic features of mucosal immunity distinguishing it from systemic immunity are: strongly developed mechanisms of innate defense, the existence of characteristic populations of unique types of lymphocytes, colonization of the mucosal and exocrine glands by cells originating from the mucosal organized tissues ('common mucosal system') and preferential induction of inhibition of the responses to nondangerous antigens (mucosal tolerance). Many chronic diseases, including allergy, may occur as a result of genetically based or environmentally induced changes in mechanisms regulating mucosal immunity and tolerance; this leads to impaired mucosal barrier

  9. Perfusion analyses in advanced breast carcinoma during hyperthermia.

    PubMed

    Lagendijk, J J; Hofman, P; Schipper, J

    1988-01-01

    Blood flow in tumours and healthy tissue determines the ability of obtaining satisfactory temperature distributions in clinical hyperthermia, as well as the success of hyperthermia and radiation treatment. During the hyperthermia treatment, diagnostic data related to tissue blood flow can be determined by analysing the relationship between the amount of power absorbed in the tissue and the resulting temperature rise. The interpretation of the perfusion data (PERF) is highly complicated by the lack of an adequate theory to describe the heat transport in vascularized tissues. In vascularized breast tissues about 10 times as much power is needed to maintain therapeutic temperatures as is necessary in a stationary breast phantom. This large difference in maintenance power levels indicates the extreme importance of blood flow in tissue heat transport. PERF has been determined in 23 patients with advanced breast tumours. In this series (a) perfusion typically did not change during the stationary part of the individual hyperthermic sessions, (b) minimum tumour PERF was not related to tumour volume, and (c) there was no relation between tumour PERF and the ability to heat tumours. PERF can both increase and decrease after successful hyperthermia. PMID:3292667

  10. Noninvasive cerebral perfusion imaging in high-risk neonates.

    PubMed

    Goff, Donna A; Buckley, Erin M; Durduran, Turgut; Wang, Jiongjong; Licht, Daniel J

    2010-02-01

    Advances in medical and surgical care of the high-risk neonate have led to increased survival. A significant number of these neonates suffer from neurodevelopmental delays and failure in school. The focus of clinical research has shifted to understanding events contributing to neurological morbidity in these patients. Assessing changes in cerebral oxygenation and regulation of cerebral blood flow (CBF) is important in evaluating the status of the central nervous system. Traditional CBF imaging methods fail for both ethical and logistical reasons. Optical near infrared spectroscopy (NIRS) is increasingly being used for bedside monitoring of cerebral oxygenation and blood volume in both very low birth weight infants and neonates with congenital heart disease. Although trends in CBF may be inferred from changes in cerebral oxygenation and/or blood volume, NIRS does not allow a direct measure of CBF in these populations. Two relatively new modalities, arterial spin-labeled perfusion magnetic resonance imaging and optical diffuse correlation spectroscopy, provide direct, noninvasive measures of cerebral perfusion suitable for the high-risk neonates. Herein we discuss the instrumentation, applications, and limitations of these noninvasive imaging techniques for measuring and/or monitoring CBF. PMID:20109972

  11. Permissive hypotension does not reduce regional organ perfusion compared to normotensive resuscitation: animal study with fluorescent microspheres

    PubMed Central

    2012-01-01

    Introduction The objective of this study was to investigate regional organ perfusion acutely following uncontrolled hemorrhage in an animal model that simulates a penetrating vascular injury and accounts for prehospital times in urban trauma. We set forth to determine if hypotensive resuscitation (permissive hypotension) would result in equivalent organ perfusion compared to normotensive resuscitation. Methods Twenty four (n=24) male rats randomized to 4 groups: Sham, No Fluid (NF), Permissive Hypotension (PH) (60% of baseline mean arterial pressure - MAP), Normotensive Resuscitation (NBP). Uncontrolled hemorrhage caused by a standardised injury to the abdominal aorta; MAP was monitored continuously and lactated Ringer’s was infused. Fluorimeter readings of regional blood flow of the brain, heart, lung, kidney, liver, and bowel were obtained at baseline and 85 minutes after hemorrhage, as well as, cardiac output, lactic acid, and laboratory tests; intra-abdominal blood loss was assessed. Analysis of variance was used for comparison. Results Intra-abdominal blood loss was higher in NBP group, as well as, lower hematocrit and hemoglobin levels. No statistical differences in perfusion of any organ between PH and NBP groups. No statistical difference in cardiac output between PH and NBP groups, as well as, in lactic acid levels between PH and NBP. NF group had significantly higher lactic acidosis and had significantly lower organ perfusion. Conclusions Hypotensive resuscitation causes less intra-abdominal bleeding than normotensive resuscitation and concurrently maintains equivalent organ perfusion. No fluid resuscitation reduces intra-abdominal bleeding but also significantly reduces organ perfusion. PMID:23531188

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

    SciTech Connect

    Goliaei, B.

    1980-08-01

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

  13. Controlled oxygenated rewarming of cold stored liver grafts by thermally graduated machine perfusion prior to reperfusion.

    PubMed

    Minor, T; Efferz, P; Fox, M; Wohlschlaeger, J; Lüer, B

    2013-06-01

    The quality of cold-stored livers declines with the extension of ischemic time, increasing the risk of primary dys or nonfunction. A new concept to rescue preserved marginal liver grafts by gentle oxygenated warming-up prior to blood reperfusion was investigated. Porcine livers were preserved by cold storage (CS) in modified HTK-solution for 18 h. Some grafts were subsequently subjected to 90 min of controlled oxygenated rewarming (COR) by machine perfusion with gradual increase of perfusate temperature up to 20°C or simple oxygenated machine perfusion in hypothermia (HMP) or subnormothermia (SNP). Graft viability was assessed thereafter by 4 h of normothermic blood reperfusion ex vivo. Endischemic tissue energetics were significantly improved by COR or SNP and to a notably lesser extent by HMP. COR significantly reduced cellular enzyme loss, gene expression and perfusate activities of TNF-alpha, radical mediated lipid peroxidation (LPO) and increase of portal vascular perfusion resistance upon reperfusion, while HMP or SNP were less protective. Only COR resulted in significantly more bile production than after CS. Histological injury score and caspase 3-activation were significantly lower after COR than after CS. Oxygenated rewarming prior to reperfusion seems to be a promising technique to improve subsequent organ recovery upon reperfusion of long preserved liver grafts. PMID:23617781

  14. Optimization of isolated perfused/ventilated mouse lung to study hypoxic pulmonary vasoconstriction

    PubMed Central

    Yoo, Hae Young; Zeifman, Amy; Ko, Eun A.; Smith, Kimberly A.; Chen, Jiwang; Machado, Roberto F.; Zhao, You-Yang; Minshall, Richard D.; Yuan, Jason X.-J.

    2013-01-01

    Hypoxic pulmonary vasoconstriction (HPV) is a compensatory physiological mechanism in the lung that optimizes the matching of ventilation to perfusion and thereby maximizes gas exchange. Historically, HPV has been primarily studied in isolated perfused/ventilated lungs; however, the results of these studies have varied greatly due to different experimental conditions and species. Therefore, in the present study, we utilized the mouse isolated perfused/ventilated lung model for investigation of the role of extracellular Ca2+ and caveolin-1 and endothelial nitric oxide synthase expression on HPV. We also compared HPV using different perfusate solutions: Physiological salt solution (PSS) with albumin, Ficoll, rat blood, fetal bovine serum (FBS), or Dulbecco's Modified Eagle Medium (DMEM). After stabilization of the pulmonary arterial pressure (PAP), hypoxic (1% O2) and normoxic (21% O2) gases were applied via a ventilator in five-minute intervals to measure HPV. The addition of albumin or Ficoll with PSS did not induce persistent and strong HPV with or without a pretone agent. DMEM with the inclusion of FBS in the perfusate induced strong HPV in the first hypoxic challenge, but the HPV was neither persistent nor repetitive. PSS with rat blood only induced a small increase in HPV amplitude. Persistent and repetitive HPV occurred with PSS with 20% FBS as perfusate. HPV was significantly decreased by the removal of extracellular Ca2+ along with addition of 1 mM EGTA to chelate residual Ca2+ and voltage-dependent Ca2+ channel blocker (nifedipine 1 μM). PAP was also reactive to contractile stimulation by high K+ depolarization and U46619 (a stable analogue of thromboxane A2). In summary, optimal conditions for measuring HPV were established in the isolated perfused/ventilated mouse lung. Using this method, we further confirmed that HPV is dependent on Ca2+ influx. PMID:24015341

  15. True versus mild hyperthermia during isolated hepatic perfusion: effects on melphalan pharmacokinetics and liver function.

    PubMed

    Pilati, Pierluigi; Mocellin, Simone; Rossi, Carlo R; Ori, Carlo; Innocente, Federico; Scalerta, Romano; Ceccherini, Mauro; Da Pian, Pier Paolo; Nitti, Donato; Lise, Mario

    2004-08-01

    Hyperthermic antiblastic isolated hepatic perfusion (IHP) with melphalan has been recently proposed as an alternative therapeutic option for patients with unresectable liver tumors. Although melphalan-heat antiblastic synergism is at a maximum at temperatures higher than 41 degrees C, IHP has so far been performed in humans at lower temperatures. In this experimental work, we compared IHP under mild versus true hyperthermic conditions in terms of drug pharmacokinetics and liver function. Ten pigs were submitted to IHP with melphalan 1.5 mg/kg at a mean temperature of 40 degrees C (group A, n = 5) or 42 degrees C (group B, n = 5). After a 60-minute perfusion, a 15-minute washout was performed. Perfusate-to-plasma leakage was monitored using scintigraphy. Throughout perfusion, samples from the systemic blood, perfusate, and liver parenchyma were obtained to measure melphalan concentrations. Liver function was assessed using standard blood tests and the indocyanine green-based test. No deaths related to the IHP procedure were recorded. All animals had transient liver function impairment, with all liver function test results returning to normal within the observation period. At histologic examination, liver damage was similar under both hyperthermic conditions. Melphalan levels in the perfusate were not significantly different in the two study groups (the mean perfusate/plasma area under the curve from 0 to 60 minutes ratios were 463 and 501, respectively). These results correlated well with those obtained using the scintigraphic method. Liver drug concentrations remained unchanged after true hyperthermia IHP. Under true hyperthermic conditions, neither an increase in liver parenchyma toxicity nor changes in melphalan pharmacokinetics were observed. These findings support the use of true hyperthermia in the clinical setting to exploit fully the antitumor synergism between melphalan and heat. PMID:15457357

  16. Correlation of magnetic resonance signal characteristics and perfusion parameters assessed by volume perfusion computed tomography in hepatocellular carcinoma: Impact on lesion characterization

    PubMed Central

    Grözinger, Gerd; Bitzer, Michael; Syha, Roland; Ketelsen, Dominik; Nikolaou, Konstantin; Lauer, Ulrich; Horger, Marius

    2016-01-01

    AIM To find out if magnetic resonance (MR)-signal characteristics of hepatocellular carcinomas (HCC) correlate with perfusion parameters assessed by volume perfusion computed tomography (VPCT). METHODS From October 2009 to January 2014, 26 (mean age, 69.3 years) patients with 36 HCC lesions who underwent both VPCT and MR liver imaging were analysed. We compared signal intensity in the T1w- and T2w-images and wash-in/wash-out kinetics on post-contrast MR images with mean values of blood flow (BF, mL/100 mL per minute), blood volume (BV, mL/100 mL), k-trans (mL/100 mL per minute), arterial liver perfusion (mL/100 mL per minute), portal venous perfusion and hepatic perfusion index (HPI, %) obtained by VPCT. Signal intensity on magnetic resonance imaging (MRI) was classified hyper/iso/hypointense compared with surrounding liver parenchyma. RESULTS Signal intensity on native T1w- and T2w-images was hyper/iso/hypo in 4/16/16 and 21/14/1 lesions, respectively. Wash-in and wash-out contrast kinetics were found on MRI in 33 of 36 lesions (91.7%) and 25 of 36 lesions (69.4%), respectively. The latter was observed significantly more often in higher graded lesions (P < 0.005). HPI was 94.7% ± 6.5%. There was no significant relationship between lesion’s MR-signal intensity, MR signal combinations, size and any of the VPCT-perfusion parameters. However HPI was constantly high in all HCC lesions. CONCLUSION VPCT parameters add limited value to MR-lesion characterization. However in HCC lesions with atypical MR signal characteristics HPI can add a parameter to ensure HCC diagnosis. PMID:27551338

  17. Hypothermia improves oral and gastric mucosal microvascular oxygenation during hemorrhagic shock in dogs.

    PubMed

    Vollmer, Christian; Schwartges, Ingo; Swertz, Meike; Beck, Christopher; Bauer, Inge; Picker, Olaf

    2013-01-01

    Hypothermia is known to improve tissue function in different organs during physiological and pathological conditions. The aim of this study was to evaluate the effects of hypothermia on oral and gastric mucosal microvascular oxygenation (μHbO2) and perfusion (μflow) under physiological and hemorrhagic conditions. Five dogs were repeatedly anesthetized. All animals underwent each experimental protocol (randomized cross-over design): hypothermia (34°C), hypothermia during hemorrhage, normothermia, and normothermia during hemorrhage. Microcirculatory and hemodynamic variables were recorded. Systemic (DO2) and oral mucosal (μDO2) oxygen delivery were calculated. Hypothermia increased oral μ HbO2 with no effect on gastric μHbO2. Hemorrhage reduced oral and gastric μHbO2 during normothermia (-36 ± 4% and -27 ± 7%); however, this effect was attenuated during additional hypothermia (-15 ± 5% and -11 ± 5%). The improved μ HbO2 might be based on an attenuated reduction in μ flow during hemorrhage and additional hypothermia (-51 ± 21 aU) compared to hemorrhage and normothermia (-106 ± 19 aU). μDO2 was accordingly attenuated under hypothermia during hemorrhage whereas DO2 did not change. Thus, in this study hypothermia alone improves oral μHbO2 and attenuates the effects of hemorrhage on oral and gastric μ HbO2. This effect seems to be mediated by an increased μDO2 on the basis of increased μ flow. PMID:24327826

  18. Mucosal malignant melanoma of the maxillary sinus.

    PubMed

    Norhafizah, M; Mustafa, W M B W; Sabariah, A R; Shiran, M S; Pathmanathan, R

    2010-09-01

    Mucosal malignant melanoma (MMM) is an aggressive tumour occurring in the upper respiratory tract. It is rare compared to malignant melanoma of the skin. We report a case of a 53-year-old man with left paranasal swelling. A biopsy showed high-grade spindle cell tumour. Subsequently a subtotal maxillectomy was performed. Histopathological examination revealed a hypercellular tumour composed of mixed spindle and epitheloid cells with very occasional intracytoplasmic melanin pigment. The malignant cells were immunopositive for vimentin, S-100 protein and HMB-45. It was diagnosed as mucosal malignant melanoma (MMM). This article illustrates a rare case of MMM where the diagnosis may be missed or delayed without proper histopathological examination that include meticulous search for melanin pigment and appropriate immunohistochemical stains to confirm the diagnosis. Malignant melanoma can mimic many other types of high-grade malignancy and should be considered as a differential diagnosis in many of these instances. PMID:21939172

  19. Probiotics as Antifungals in Mucosal Candidiasis.

    PubMed

    Matsubara, Victor H; Bandara, H M H N; Mayer, Marcia P A; Samaranayake, Lakshman P

    2016-05-01

    Candidais an opportunistic pathogen that causes mucosal and deep systemic candidiasis. The emergence of drug resistance and the side effects of currently available antifungals have restricted their use as long-term prophylactic agents for candidal infections. Given this scenario, probiotics have been suggested as a useful alternative for the management of candidiasis. We analyzed the available data on the efficacy of probiotics in candidal colonization of host surfaces. A number of well-controlled studies indicate that probiotics, particularly lactobacilli, suppressCandidagrowth and biofilm development in vitro.A few clinical trials have also shown the beneficial effects of probiotics in reducing oral, vaginal, and enteric colonization byCandida; alleviation of clinical signs and symptoms; and, in some cases, reducing the incidence of invasive fungal infection in critically ill patients. Probiotics may serve in the future as a worthy ally in the battle against chronic mucosal candidal infections. PMID:26826375

  20. Dopaminergic Therapy Modulates Cortical Perfusion in Parkinson Disease With and Without Dementia According to Arterial Spin Labeled Perfusion Magnetic Resonance Imaging

    PubMed Central

    Lin, Wei-Che; Chen, Pei-Chin; Huang, Yung-Cheng; Tsai, Nai-Wen; Chen, Hsiu-Ling; Wang, Hung-Chen; Lin, Tsu-Kung; Chou, Kun-Hsien; Chen, Meng-Hsiang; Chen, Yi-Wen; Lu, Cheng-Hsien

    2016-01-01

    Abstract Arterial spin labeling (ASL) magnetic resonance imaging analyses allow for the quantification of altered cerebral blood flow, and provide a novel means of examining the impact of dopaminergic treatments. The authors examined the cerebral perfusion differences among 17 Parkinson disease (PD) patients, 17 PD with dementia (PDD) patients, and 17 healthy controls and used ASL-MRI to assess the effects of dopaminergic therapies on perfusion in the patients. The authors demonstrated progressive widespread cortical hypoperfusion in PD and PDD and robust effects for the dopaminergic therapies. Specifically, dopaminergic medications further decreased frontal lobe and cerebellum perfusion in the PD and PDD groups, respectively. These patterns of hypoperfusion could be related to cognitive dysfunctions and disease severity. Furthermore, desensitization to dopaminergic therapies in terms of cortical perfusion was found as the disease progressed, supporting the concept that long-term therapies are associated with the therapeutic window narrowing. The highly sensitive pharmaceutical response of ASL allows clinicians and researchers to easily and effectively quantify the absolute perfusion status, which might prove helpful for therapeutic planning. PMID:26844450

  1. Myocardial perfusion echocardiography and coronary microvascular dysfunction

    PubMed Central

    Barletta, Giuseppe; Del Bene, Maria Riccarda

    2015-01-01

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

  2. Myocardial perfusion echocardiography and coronary microvascular dysfunction.

    PubMed

    Barletta, Giuseppe; Del Bene, Maria Riccarda

    2015-12-26

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

  3. Effects of cold atmospheric plasma on mucosal tissue culture

    NASA Astrophysics Data System (ADS)

    Welz, Christian; Becker, Sven; Li, Yang-Fang; Shimizu, Tetsuji; Jeon, Jin; Schwenk-Zieger, Sabina; Thomas, Hubertus M.; Isbary, Georg; Morfill, Gregor E.; Harréus, Ulrich; Zimmermann, Julia L.

    2013-01-01

    Thermal plasmas have been commonly used in medical applications such as plasma ablation and blood coagulation. Newer developments show that plasmas can be generated with ion temperatures close to room temperature: these non-thermal or so-called cold atmospheric plasmas (CAPs) therefore open up a wide range of further biomedical applications. Based on the understanding of the bactericidal, virucidal and fungicidal properties of CAPs, information about the effects of CAP on mucosal cells and tissue is still lacking. Therefore this study focuses on the interaction of CAP with healthy head and neck mucosal cells on a molecular level. To analyse this interaction in detail, fresh tissue samples from healthy nasal and pharyngeal mucosa were harvested during surgery, assembled to a three-dimensional tissue culture model (mini organ cultures) and treated with CAP for different treatment times. Effects on the viability, necrosis induction and mutagenic activity were evaluated with the trypan blue exclusion test, Annexin-V/PI staining and alkaline microgel electrophoresis (comet assay). Trypan blue exclusion test revealed that the CAP treatment significantly decreases the cell viability for all tested treatment times (5, 10, 30, 60 and 120 s p < 0.05), but only a treatment time of 120 s showed a cytotoxic effect as the viability dropped below 90%. Annexin-V/PI staining revealed a significant increase in necrosis in CAP treated pharyngeal tissue cultures for treatment times of 60 and 120 s (p < 0.05). For nasal tissue this effect was already detected for a 30 s treatment (p < 0.05). Comet assay analysis showed no mutagenic effects after exposure to CAP.

  4. Cough-induced Tracheobronchial Mucosal Bleeding.

    PubMed

    Hira, Harmanjit Singh

    2011-01-01

    A 56-year-old man presented with moderate hemoptysis. It was preceded by a severe bout of cough. Flexible bronchoscopy showed diffuse tracheobronchial mucosal petechiae and bleeding. The patient was not suffering with any coagulopathies. He did not receive antiplatelet drugs. Hemoptysis resolved with cough suppressant. Subsequent bronchoscopy revealed the complete resolution of petechiae. The mechanism of bleeding after the bout of coughing is discussed. PMID:23169019

  5. The microbiome and regulation of mucosal immunity.

    PubMed

    McDermott, Andrew J; Huffnagle, Gary B

    2014-05-01

    The gastrointestinal tract is a mucosal surface constantly exposed to foreign antigens and microbes, and is protected by a vast array of immunologically active structures and cells. Epithelial cells directly participate in immunological surveillance and direction of host responses in the gut and can express numerous pattern recognition receptors, including Toll-like receptor 5 (TLR5), TLR1, TLR2, TLR3, TLR9, and nucleotide oligomerization domain 2, as well as produce chemotactic factors for both myeloid and lymphoid cells following inflammatory stimulation. Within the epithelium and in the underlying lamina propria resides a population of innate lymphoid cells that, following stimulation, can become activated and produce effector cytokines and exert both protective and pathogenic roles during inflammation. Lamina propria dendritic cells play a large role in determining whether the response to a particular antigen will be inflammatory or anti-inflammatory. It is becoming clear that the composition and metabolic activity of the intestinal microbiome, as a whole community, exerts a profound influence on mucosal immune regulation. The microbiome produces short-chain fatty acids, polysaccharide A, α-galactosylceramide and tryptophan metabolites, which can induce interleukin-22, Reg3γ, IgA and interleukin-17 responses. However, much of what is known about microbiome-host immune interactions has come from the study of single bacterial members of the gastrointestinal microbiome and their impact on intestinal mucosal immunity. Additionally, evidence continues to accumulate that alterations of the intestinal microbiome can impact not only gastrointestinal immunity but also immune regulation at distal mucosal sites. PMID:24329495

  6. Nitric oxide as a mediator of gastrointestinal mucosal injury?—Say it ain't so

    PubMed Central

    Kubes, Paul

    1995-01-01

    Nitric oxide has been suggested as a contributor to tissue injury in various experimental models of gastrointestinal inflammation. However, there is overwhelming evidence that nitric oxide is one of the most important mediators of mucosal defence, influencing such factors as mucus secretion, mucosal blood flow, ulcer repair and the activity of a variety of mucosal immunocytes. Nitric oxide has the capacity to down-regulate inflammatory responses in the gastrointestinal tract, to scavenge various free radical species and to protect the mucosa from injury induced by topical irritants. Moreover, questions can be raised regarding the evidence purported to support a role for nitric oxide in producing tissue injury. In this review, we provide an overview of the evidence supporting a role for nitric oxide in protecting the gastrointestinal tract from injury. PMID:18475671

  7. Electroporation mediated DNA vaccination directly to a mucosal surface results in improved immune responses

    PubMed Central

    Kichaev, Gleb; Mendoza, Janess M; Amante, Dinah; Smith, Trevor RF; McCoy, Jay R; Sardesai, Niranjan Y; Broderick, Kate E

    2013-01-01

    In vivo electroporation (EP) has been shown to be a highly efficient non-viral method for enhancing DNA vaccine delivery and immunogenicity, when the site of immunization is the skin or muscle of animals and humans. However, the route of entry for many microbial pathogens is via the mucosal surfaces of the human body. We have previously reported on minimally invasive, surface and contactless EP devices for enhanced DNA delivery to dermal tissue. Robust antibody responses were induced following vaccine delivery in several tested animal models using these devices. Here, we investigated extending the modality of the surface device to efficiently deliver DNA vaccines to mucosal tissue. Initially, we demonstrated reporter gene expression in the epithelial layer of buccal mucosa in a guinea pig model. There was minimal tissue damage in guinea pig mucosal tissue resulting from EP. Delivery of a DNA vaccine encoding influenza virus nucleoprotein (NP) of influenza H1N1 elicited robust and sustained systemic IgG antibody responses following EP-enhanced delivery in the mucosa. Upon further analysis, IgA antibody responses were detected in vaginal washes and sustained cellular immune responses were detected in animals immunized at the oral mucosa with the surface EP device. This data confirms that DNA delivery and EP targeting mucosal tissue directly results in both robust and sustainable humoral as well as cellular immune responses without tissue damage. These responses are seen both in the mucosa and systemically in the blood. Direct DNA vaccine delivery enhanced by EP in mucosa may have important clinical applications for delivery of prophylactic and therapeutic DNA vaccines against diseases such as HIV, HPV and pneumonia that enter at mucosal sites and require both cellular and humoral immune responses for protection. PMID:23954979

  8. Electroporation mediated DNA vaccination directly to a mucosal surface results in improved immune responses.

    PubMed

    Kichaev, Gleb; Mendoza, Janess M; Amante, Dinah; Smith, Trevor R F; McCoy, Jay R; Sardesai, Niranjan Y; Broderick, Kate E

    2013-10-01

    In vivo electroporation (EP) has been shown to be a highly efficient non-viral method for enhancing DNA vaccine delivery and immunogenicity, when the site of immunization is the skin or muscle of animals and humans. However, the route of entry for many microbial pathogens is via the mucosal surfaces of the human body. We have previously reported on minimally invasive, surface and contactless EP devices for enhanced DNA delivery to dermal tissue. Robust antibody responses were induced following vaccine delivery in several tested animal models using these devices. Here, we investigated extending the modality of the surface device to efficiently deliver DNA vaccines to mucosal tissue. Initially, we demonstrated reporter gene expression in the epithelial layer of buccal mucosa in a guinea pig model. There was minimal tissue damage in guinea pig mucosal tissue resulting from EP. Delivery of a DNA vaccine encoding influenza virus nucleoprotein (NP) of influenza H1N1 elicited robust and sustained systemic IgG antibody responses following EP-enhanced delivery in the mucosa. Upon further analysis, IgA antibody responses were detected in vaginal washes and sustained cellular immune responses were detected in animals immunized at the oral mucosa with the surface EP device. This data confirms that DNA delivery and EP targeting mucosal tissue directly results in both robust and sustainable humoral as well as cellular immune responses without tissue damage. These responses are seen both in the mucosa and systemically in the blood. Direct DNA vaccine delivery enhanced by EP in mucosa may have important clinical applications for delivery of prophylactic and therapeutic DNA vaccines against diseases such as HIV, HPV and pneumonia that enter at mucosal sites and require both cellular and humoral immune responses for protection. PMID:23954979

  9. Multiple intestinal 'loops' provide an in vivo model to analyse multiple mucosal immune responses.

    PubMed

    Gerdts, V; Uwiera, R R; Mutwiri, G K; Wilson, D J; Bowersock, T; Kidane, A; Babiuk, L A; Griebel, P J

    2001-10-01

    Mucosal immunity plays an important role in preventing disease but the induction of protective mucosal immune responses remains a significant challenge. We describe a novel in vivo model to analyze the induction of multiple mucosal immune responses in the small intestine. A sterile segment of intestine ('intestinal-segment'; 2-3 m long) was surgically prepared in the jejunum of 4-6-month-old lambs. This 'intestinal-segment' was then subdivided into consecutive segments, designated as 'loops' (15-20 cm long), that included a Peyer's patch (PP), or 'interspaces' (15-70 cm long), that lacked a visible PP. All 'loops' were sterile when collected 1-4 weeks post-surgery and there was no macroscopic or histological evidence of altered lymph or blood flow. Flow cytometric analysis of cells isolated from PP, mucosal epithelium (IEL) and the lamina propria (LPL) revealed no significant alterations in the cell populations present in 'loop' tissues. The functional integrity of M-cell antigen uptake in sterile intestinal 'loops' was evaluated by comparing the immune response induced by varying doses of soluble versus particulate porcine serum albumin (PSA formulated in alginate microspheres). A dose-dependent, PSA-specific antibody-secreting cell response was restricted to PP present in 'loops' injected with particulate PSA. These observations suggested that PP present in sterile 'loops' were functional and this conclusion was confirmed by detecting cholera toxin-specific antibody-secreting cells and secreted antibody in PP and intestinal contents, respectively, of immunized 'loops.' Thus, each 'loop' provided an independent site to analyze antigen-uptake and the induction of mucosal immune responses by a variety of antigen or vaccine formulations. PMID:11516752

  10. Quantification of brain perfusion with tracers retained by the brain

    SciTech Connect

    Pupi, A.; Bacciottini, L.; De Cristofaro, M.T.R.; Formiconi, A.R.; Castagnoli, A.

    1991-12-31

    Almost a decade ago, tracers, labelled with {sup 123}I and {sup 99m}Tc, that are retained by the brain, started to be used for studies of regional brain perfusion (regional cerebral blood flow, rCBF). To date, these tracers have been used for brain perfusion imaging with SPECT in brain disorders as well as for physiological activation protocols. Only seldom, however, have they been used in protocols that quantitatively measure rCBF. Nevertheless, comparative studies with perfusion reference tracers have repeatedly demonstrated that the brain uptake of these brain-retained tracers is correlated to perfusion, the major determinant of the distribution of these tracers in the brain. The brain kinetics of {sup 99m}Tc HMPAO, which is the tracer most commonly used, was described with a two-compartment tissue model. The theoretical approach, which is, in itself, sufficient for modeling quantitative measurements with {sup 99m}Tc HMPAO, initially suggested the possibility of empirically narrowing the distance between the brain`s regional uptake of the tracer and rCBF with a linearization algorithm which uses the cerebellum as the reference region. The value of this empirical method is hampered by the fact that the cerebellum can be involved in cerebrovascular disease (i.e. cerebellar diaschisis) as well as in several other brain disorders (e.g. anxiety, and dementia of the Alzheimer type). It also was proposed that different reference regions (occipital, whole slice, or whole brain) should be selected in relation to the brain disorder under study. However, this approach does not solve the main problem because it does not equip us with a reliable tool to evaluate rCBF with a high predictive value, and, at the same time, to reduce intersubject variability. The solution would be to measure a quantitative parameter which directly reflects rCBF, such as the unidirectional influx constant of the freely diffusible flow-limited tracers. 45 refs., 3 figs., 1 tab.

  11. Topical cocaine for relief of mucosal pain.

    PubMed

    Newport, Kristina; Coyne, Patrick

    2010-06-01

    Painful mucosal lesions negatively affect quality of life. When located in the oral cavity, they can cause pain that interferes with speech and swallowing. Acute pain from intra-oral lesions is difficult to treat with conventional methods such as systemic opioids or viscous lidocaine. These cases exemplify a safe, fast and effective method for treating painful mouth lesions that are not responsive to standard treatments. Mr. D and Mr. G had from painful oral lesions caused by squamous cell carcinoma. Severe pain interfered with their ability to speak and swallow, resulting in poor nutrition and dehydration. 4% liquid cocaine, self-applied topically to the open mouth sores, resulted in relief within minutes in both cases. Repeated dosing every six hours allowed both patients to restart oral nutrition without any reported side effects. Topical cocaine has not been described for repeated dosing for oral or other mucosal pain. Potential side effects of mucosal administration include gingival recession and erythematous lesions. If the recommended topical doses are exceeded, liquid cocaine may be absorbed systemically causing a stimulant response or addiction. When used appropriately, however, this intervention can result in a dramatic improvement in quality of life and functional status. PMID:20504138

  12. Collaborative studies in mucosal immunology in Goroka.

    PubMed

    Clancy, Robert

    2010-01-01

    A collaborative program between the Papua New Guinea (PNG) Institute of Medical Research and the Hunter Mucosal Group has completed studies relevant to protection of the airways against bacterial infection. Specifically, these studies addressed the mucosal capacity to produce local immunoglobulins and the capacity of the airways to respond to an oral vaccine containing inactivated nontypeable Haemophilus influenzae (NTHi). The mucosal IgA response to NTHi antigens was blunted in both children and adults in PNG compared with that found in Australian children and adults, whose airways are colonized only intermittently. Despite this, when oral NTHi is given to Papua New Guinean adults with chronic airways disease, it is followed by a significant (50%) reduction in incidence of acute bronchitic episodes, and a 3-log reduction in density of colonization, which persisted about 10 months. The implications of these key findings are discussed with respect to both mechanism and wider control of pathology emanating from abnormal airways colonization in a PNG environment. PMID:23163182

  13. Oral mucosal manifestations of autoimmune skin diseases.

    PubMed

    Mustafa, Mayson B; Porter, Stephen R; Smoller, Bruce R; Sitaru, Cassian

    2015-10-01

    A group of autoimmune diseases is characterised by autoantibodies against epithelial adhesion structures and/or tissue-tropic lymphocytes driving inflammatory processes resulting in specific pathology at the mucosal surfaces and the skin. The most frequent site of mucosal involvement in autoimmune diseases is the oral cavity. Broadly, these diseases include conditions affecting the cell-cell adhesion causing intra-epithelial blistering and those where autoantibodies or infiltration lymphocytes cause a loss of cell-matrix adhesion or interface inflammation. Clinically, patients present with blistering, erosions and ulcers that may affect the skin as well as further mucosal surfaces of the eyes, nose and genitalia. While the autoimmune disease may be suspected based on clinical manifestations, demonstration of tissue-bound and circulating autoantibodies, or lymphocytic infiltrates, by various methods including histological examination, direct and indirect immunofluorescence microscopy, immunoblotting and quantitative immunoassay is a prerequisite for definitive diagnosis. Given the frequency of oral involvement and the fact that oral mucosa is the initially affected site in many cases, the informed practitioner should be well acquainted with diagnostic and therapeutic aspects of autoimmune dermatosis with oral involvement. This paper reviews the pathogenesis and clinical presentation of these conditions in the oral cavity with a specific emphasis on their differential diagnosis and current management approaches. PMID:26117595

  14. Chitosan-based mucosal adjuvants: Sunrise on the ocean.

    PubMed

    Xia, Yufei; Fan, Qingze; Hao, Dongxia; Wu, Jie; Ma, Guanghui; Su, Zhiguo

    2015-11-01

    Mucosal vaccination, which is shown to elicit systemic and mucosal immune responses, serves as a non-invasive and convenient alternative to parenteral administration, with stronger capability in combatting diseases at the site of entry. The exploration of potent mucosal adjuvants is emerging as a significant area, based on the continued necessity to amplify the immune responses to a wide array of antigens that are poorly immunogenic at the mucosal sites. As one of the inspirations from the ocean, chitosan-based mucosal adjuvants have been developed with unique advantages, such as, ability of mucosal adhesion, distinct trait of opening the junctions to allow the paracellular transport of antigen, good tolerability and biocompatibility, which guaranteed the great potential in capitalizing on their application in human clinical trials. In this review, the state of art of chitosan and its derivatives as mucosal adjuvants, including thermo-sensitive chitosan system as mucosal adjuvant that were newly developed by author's group, was described, as well as the clinical application perspective. After a brief introduction of mucosal adjuvants, chitosan and its derivatives as robust immune potentiator were discussed in detail and depth, in regard to the metabolism, safety profile, mode of actions and preclinical and clinical applications, which may shed light on the massive clinical application of chitosan as mucosal adjuvant. PMID:26271831

  15. Long term perfusion system supporting adipogenesis

    PubMed Central

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

    2015-01-01

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

  16. Replacing the acetyl linkage in aspirin with choline and magnesium moieties reduces the occurrence of gastric mucosal injury.

    PubMed

    Danesh, B J; Nelson, L M; Russell, R I; Docherty, C

    1987-02-01

    The acetyl moiety in aspirin (acetyl salicylic acid: ASA) is considered to play a major part in the pathogenesis of ASA-induced mucosal injury. At equivalent salicylate doses and pH values, the induction of acute gastric mucosal haemorrhagic erosions in rats by ASA and choline magnesium trisalicylate (CMT), a new non-acetylated salicylate, with and without the potentiating damaging effect of taurodeoxycholic acid (TDCA) were compared. Test solutions were administered by per oral intubation to five groups of fasting Sprague-Dawley rats (n = 24). Gastric mucosa were examined after 4 hours and mucosal injury assessed by a lesion-scoring system. The incidence and severity (median lesion scores with quartiles) of the lesions were 83% and 13 (7:20) respectively for ASA (128 mg kg-1) compared with 17% and 0 (0:0) for CMT (128 mg kg-1) (P less than 0.001 and P less than 0.001). TDCA increased mucosal damage to 100% and 29 (20:34) for ASA compared with 30% and 0 (0:4) for CMT (P less than 0.001) and P less than 0.001). Serum salicylate levels (median values of 1.4 for ASA and 1.5 mmol litre-1 for CMT) were not significantly different. It is concluded that replacing the acetyl moiety in ASA with choline and magnesium moieties reduces the ASA-induced mucosal injury, without affecting blood salicylate concentrations. PMID:2979212

  17. IL-17-producing innate lymphoid cells are restricted to mucosal tissues and are depleted in SIV-infected macaques

    PubMed Central

    Xu, Huanbin; Wang, Xiaolei; Liu, David X.; Moroney-Rasmussen, Terri; Lackner, Andrew A.; Veazey, Ronald S.

    2013-01-01

    SUMMARY Innate lymphoid cells (ILCs) are an emerging subset of lymphocytes involved in surveillance against virally infected cells. Here we show CD3−CD8high lymphocytes in macaque blood include major subsets of ILCs including NK cells expressing CD16, NKp46 and NKG2A, but also populations of ILCs in mucosal tissues having different properties. One ILC subset secreted IL-17 (ILC17), but these were restricted to mucosal tissues. Some mucosal ILC17 cells expressed classical NK-cell markers, but little NKG2A or NKG2D. Some ILC17 cells secreted IL-22 and TNF-α, but few produced IFN-γ or contained granzyme B. IL-17 production by ILCs was induced by IL-6, TGF-β and IL-23. Further, SIV infection resulted in a significant loss of ILC17 cells, especially in the jejunum, which persisted throughout SIV infection. These findings ILC17 cells may be involved in innate mucosal immune responses, and their loss may contribute to loss of intestinal mucosal integrity and disease progression in HIV/SIV infection. PMID:22669579

  18. Effect of glucagon and pentagastrin on gastric mucosal potential difference in man.

    PubMed Central

    Tarnawski, A; Ivey, K J; McGuigan, J E; England, J

    1978-01-01

    Glucagon given as an intravenous injection of 2 mg (0.57 mmol) or as constant intravenous infusion of 1.64 microgram/kg/h (0.47 nmol/kg/h) significantly increased gastric mucosal potential difference (PD) in man. Pentagastrin infusion of 2 microgram/kg/h (2.8 nmol/kg/h) dramatically reduced gastric PD in man. The effect of each of these hormones on PD was reversed by the administration of the other. Changes in PD induced by one hormone were not associated with reductions in blood levels of the other. There was an approximate correlation between changes in PD and pH of gastric aspirates, however, the patterns of PD and pH changes were at times dissimilar. This study indicates that administration of gastrointestinal hormones significantly alters gastric mucosal PD in man. PMID:33874

  19. Roles of M cells in infection and mucosal vaccines

    PubMed Central

    Wang, Miao; Gao, Zeqian; Zhang, Zhongwang; Pan, Li; Zhang, Yongguang

    2014-01-01

    The mucosal immune system plays a crucial part in the control of infection. Exposure of humans and animals to potential pathogens generally occurs through mucosal surfaces, thus, strategies that target the mucosa seem rational and efficient vaccination measures. Vaccination through the mucosal immune system can induce effective systemic immune responses simultaneously with mucosal immunity compared with parenteral vaccination. M cells are capable of transporting luminal antigens to the underlying lymphoid tissues and can be exploited by pathogens as an entry portal to invade the host. Therefore, targeting M-cell-specific molecules might enhance antigen entry, initiate the immune response, and induce protection against mucosal pathogens. Here, we outline our understanding of the distribution and function of M cells, and summarize the advances in mucosal vaccine strategies that target M cells. PMID:25483705

  20. Mucosal vaccines: novel advances in technology and delivery.

    PubMed

    Yuki, Yoshikazu; Kiyono, Hiroshi

    2009-08-01

    Mucosal vaccines are considered the most suitable type of vaccines to combat emerging and re-emerging infectious diseases because of their ability to induce both mucosal and systemic immunity. Considerable advances have been made toward the development of mucosal vaccines against influenza virus and rotavirus. Many additional mucosal vaccines are in development, including vaccines against cholera, typhoid, traveler's diarrhea and respiratory infections. In addition to oral and nasal vaccines, transcutaneous (or skin patch) and sublingual immunizations are now part of a new generation of mucosal vaccines. Furthermore, a rice-based oral vaccine (MucoRice) has been receiving global attention as a new form of cold chain-free vaccine, because it is stable at room temperature for a prolonged period. This review describes recent developments in mucosal vaccines with promising preclinical and clinical results. PMID:19627189

  1. Antibodies and Their Receptors: Different Potential Roles in Mucosal Defense

    PubMed Central

    Horton, Rachel E.; Vidarsson, Gestur

    2013-01-01

    Over recent years it has become increasingly apparent that mucosal antibodies are not only restricted to the IgM and IgA isotypes, but that also other isotypes and particularly IgG can be found in significant quantities at some mucosal surfaces, such as in the genital tract. Their role is more complex than traditionally believed with, among other things, the discovery of novel function of mucosal immunoglobulin receptors. A thorough knowledge in the source and function and mucosal immunoglobulins is particularly important in development of vaccines providing mucosal immunity, and also in the current climate of microbicide development, to combat major world health issues such as HIV. We present here a comprehensive review of human antibody mediated mucosal immunity. PMID:23882268

  2. Comparison of Indocyanine Green Angiography and Laser Speckle Contrast Imaging for the Assessment of Vasculature Perfusion

    PubMed Central

    Towle, Erica L.; Richards, Lisa M.; Kazmi, S. M. Shams; Fox, Douglas J.; Dunn, Andrew K.

    2013-01-01

    BACKGROUND Assessment of the vasculature is critical for overall success in cranial vascular neurological surgery procedures. Although several methods of monitoring cortical perfusion intraoperatively are available, not all are appropriate or convenient in a surgical environment. Recently, 2 optical methods of care have emerged that are able to obtain high spatial resolution images with easily implemented instrumentation: indocyanine green (ICG) angiography and laser speckle contrast imaging (LSCI). OBJECTIVE To evaluate the usefulness of ICG and LSCI in measuring vessel perfusion. METHODS An experimental setup was developed that simultaneously collects measurements of ICG fluorescence and LSCI in a rodent model. A 785-nm laser diode was used for both excitation of the ICG dye and the LSCI illumination. A photothrombotic clot model was used to occlude specific vessels within the field of view to enable comparison of the 2 methods for monitoring vessel perfusion. RESULTS The induced blood flow change demonstrated that ICG is an excellent method for visualizing the volume and type of vessel at a single point in time; however, it is not always an accurate representation of blood flow. In contrast, LSCI provides a continuous and accurate measurement of blood flow changes without the need of an external contrast agent. CONCLUSION These 2 methods should be used together to obtain a complete understanding of tissue perfusion. PMID:22843129

  3. Labetalol does not decrease placental perfusion in the hypertensive term-pregnant rat.

    PubMed

    Ahokas, R A; Mabie, W C; Sibai, B M; Anderson, G D

    1989-02-01

    The acute effect of labetalol hydrochloride, a combined nonspecific beta-adrenergic and postsynaptic alpha 1-adrenergic blocker, on maternal hemodynamics and organ perfusion was investigated in 10 hypertensive, term-pregnant, spontaneously hypertensive rats with the use of the radioactive-labeled microsphere technique. The normal fall in blood pressure during pregnancy was prevented by the reduction of litter size to two conceptuses on day 7 of gestation. Labetalol (1 to 6 mg/kg) effectively lowered mean arterial pressure 22% by decreasing cardiac output 16%; total peripheral resistance was not significantly decreased. Thus, the blood pressure lowering effect of labetalol was due primarily to its beta-adrenergic blocking effect. Regional flows to the carcass and splanchnic circulation were decreased 19% and 15%, respectively, after labetalol administration. Uterine wall and ovarian perfusion were significantly reduced, but placental perfusion was not significantly altered. Because labetalol lowers blood pressure without reducing placental perfusion, it may be a useful alternative to hydralazine for the treatment of hypertensive emergencies in pregnancy. PMID:2916636

  4. Enhanced Th1/Th17 Functions of CD161+ CD8+ T Cells in Mucosal Tissues of Rhesus Macaques

    PubMed Central

    2016-01-01

    Expression of the C-type lectin-like receptor CD161 by human T cells is associated with type-17 responses, which play critical regulatory roles in immunity and inflammation at mucosal sites. However, the functions of CD161-expressing T cells in macaques, the pre-clinical model of several human diseases, remain unknown. This study examined the phenotypic and functional characteristics of CD161+ T cells in peripheral blood, mucosal tissues and lymph nodes of rhesus macaques. Majority of CD161-expressing T cells in peripheral blood and lung/intestinal mucosal tissues of rhesus macaques were found to be CD8+CD4– in phenotype. There was a significant enrichment of CD161+CD8+ T cells in the lungs and colonic mucosa (16.1%±6.6 and 16.8%±5.7) in comparison to peripheral blood (4.2%±1.2) and mesenteric lymph nodes (1.3%±0.8). Regardless of the tissue compartment, CD161+CD8+ T cells mainly comprised of γδ T cells and TCR Vα7.2+ MAIT cells (up to 80%), and displayed Th1 and Th17 cytokine responses to mitogen stimulation. Mucosal CD161+CD8+ T cells were characterized by very high expression of CD69, a recent activation marker that is preferentially expressed on tissue resident cells. Furthermore, lung and colonic mucosal CD161+CD8+ T cells showed enhanced IFN-γ, IL-17, and Perforin production in comparison to those in blood. Thus, macaque CD161+CD8+ T cells represent mucosal tissue-homing innate-like CD8+ T-cell populations with Th1/Th17 type cytokine and cytotoxic effector functions that can potentially enhance the recruitment of adaptive immune cells and control initial pathogen burden/dissemination in tissues. Analysis of their role in early immune responses to mucosal pathogens will be valuable in the design of vaccines and therapeutics. PMID:27309719

  5. Concurrent Mucosal Melanoma and Angiofibroma of the Nose

    PubMed Central

    Hwang, Jae Hyung; Ha, Jin Bu; Lee, Junguee; Lee, Joohyung

    2016-01-01

    Malignant melanoma rarely develops in the paranasal sinuses, and generally has a poor prognosis. However, mucosal melanoma can masquerade both clinically and histopathologically as a benign lesion, rendering accurate early diagnosis difficult. On the other hand, angiofibroma, a benign tumor, is more easily diagnosed than a mucosal melanoma, because the former exhibits specific histopathological features. No cases of concurrent angiofibroma and mucosal melanoma have been reported to date. We describe such a case below. PMID:27095516

  6. Mucosal-associated invariant T cell alterations in obese and type 2 diabetic patients

    PubMed Central

    Magalhaes, Isabelle; Pingris, Karine; Poitou, Christine; Bessoles, Stéphanie; Venteclef, Nicolas; Kiaf, Badr; Beaudoin, Lucie; Da Silva, Jennifer; Allatif, Omran; Rossjohn, Jamie; Kjer-Nielsen, Lars; McCluskey, James; Ledoux, Séverine; Genser, Laurent; Torcivia, Adriana; Soudais, Claire; Lantz, Olivier; Boitard, Christian; Aron-Wisnewsky, Judith; Larger, Etienne; Clément, Karine; Lehuen, Agnès

    2015-01-01

    Obesity and type 2 diabetes (T2D) are associated with low-grade inflammation, activation of immune cells, and alterations of the gut microbiota. Mucosal-associated invariant T (MAIT) cells, which are innate-like T cells that recognize bacterial ligands, are present in blood and enriched in mucosal and inflamed tissues. Here, we analyzed MAIT cells in the blood and adipose tissues of patients with T2D and/or severe obesity. We determined that circulating MAIT cell frequency was dramatically decreased in both patient groups, and this population was even undetectable in some obese patients. Moreover, in both patient groups, circulating MAIT cells displayed an activated phenotype that was associated with elevated Th1 and Th17 cytokine production. In obese patients, MAIT cells were more abundant in adipose tissue than in the blood and exhibited a striking IL-17 profile. Bariatric surgery in obese patients not only improved their metabolic parameters but also increased circulating MAIT cell frequency at 3 months after surgery. Similarly, cytokine production by blood MAIT cells was strongly decreased after surgery. This study reveals profound MAIT cell abnormalities in patients harboring metabolic disorders, suggesting their potential role in these pathologies. PMID:25751065

  7. Blood transfusion before radiation for malignancies

    SciTech Connect

    Hunt, T.K. )

    1989-10-27

    This editorial discusses the situation of administering blood to patients prior to radiotherapy in an attempt to increase tissue/tumor oxygen tension. The author believes that since the rate at which tumor cells consume oxygen is highly variable, the aim of achieving high cellular oxygen tension may be met better by maintaining a high blood perfusion rate. Blood volume can be maintained without relying on transfusion, and safer alternatives are available.

  8. High-resolution renal perfusion mapping using contrast-enhanced ultrasonography in ischemia-reperfusion injury monitors changes in renal microperfusion.

    PubMed

    Fischer, Krisztina; Meral, F Can; Zhang, Yongzhi; Vangel, Mark G; Jolesz, Ferenc A; Ichimura, Takaharu; Bonventre, Joseph V

    2016-06-01

    Alterations in renal microperfusion play an important role in the development of acute kidney injury with long-term consequences. Here we used contrast-enhanced ultrasonography as a novel method for depicting intrarenal distribution of blood flow. After infusion of microbubble contrast agent, bubbles were collapsed in the kidney and postbubble destruction refilling was measured in various regions of the kidney. Local perfusion was monitored in vivo at 15, 30, 45, 60 minutes and 24 hours after 28 minutes of bilateral ischemia in 12 mice. High-resolution, pixel-by-pixel analysis was performed on each imaging clip using customized software, yielding parametric perfusion maps of the kidney, representing relative blood volume in each pixel. These perfusion maps revealed that outer medullary perfusion decreased disproportionately to the reduction in the cortical and inner medullary perfusion after ischemia. Outer medullary perfusion was significantly decreased by 69% at 60 minutes postischemia and remained significantly less (40%) than preischemic levels at 24 hours postischemia. Thus, contrast-enhanced ultrasonography with high-resolution parametric perfusion maps can monitor changes in renal microvascular perfusion in space and time in mice. This novel technique can be translated to clinical use in man. PMID:27165821

  9. The role of perfusion in the oxygen extraction capability of skin and skeletal muscle.

    PubMed

    Thorn, Clare E; Shore, Angela C

    2016-05-15

    Oxygen extraction (OE) by all cells is dependent on an adequate supply of oxygen in proximal blood vessels and the cell's need and ability to uptake that oxygen. Here the role of blood flow in regulating OE in skin and skeletal muscle was investigated in lean and obese men. OE was derived by two optical reflectance spectroscopy techniques: 1) from the rate of fall in mean blood saturation during a 4 min below knee arterial occlusion, and thus no blood flow, in calf skin and skeletal muscle and 2) in perfused, unperturbed skin, using the spontaneous falls in mean blood saturation induced by vasomotion in calf and forearm skin of 24 subjects, 12 lean and 12 obese. OE in perfused skin was significantly higher in lean compared with obese subjects in forearm (Mann-Whitney, P < 0.004) and calf (P < 0.001) and did not correlate with OE in unperfused skin (ρ = -0.01, P = 0.48). With arterial occlusion and thus no blood flow, skin OE in lean and obese subjects no longer differed (P = 0.23, not significant). In contrast in skeletal muscle with arterial occlusion and no blood flow, the difference in OE between lean and obese subjects occurred, with obese subjects exhibiting significantly higher OE (P < 0.012). The classic model of metabolic blood flow regulation to support oxygen extraction is evident in perfused skin; OE is perturbed without blood flow and reduced in obesity. In resting skeletal muscle other mechanism(s), independent of blood flow, are implicated in oxygen extraction. PMID:27016577

  10. Brain perfusion in acute and chronic hyperglycemia in rats

    SciTech Connect

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

    1989-08-01

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

  11. Microbiota and their role in the pathogenesis of oral mucositis.

    PubMed

    Vanhoecke, B; De Ryck, T; Stringer, A; Van de Wiele, T; Keefe, D

    2015-01-01

    Oral mucositis in patients undergoing cancer therapy is a significant problem. Its prevalence ranges between 20 and 100%, depending on treatment type and protocols and patient-based variables. Mucositis is self-limiting when uncomplicated by infection. Unfortunately, the incidence of developing a local or systemic infection during the course of the treatment is very high. At this stage, it is unclear which role oral microbiota play in the onset, duration, and severity of oral mucositis. Nevertheless, there is growing interest in this underexplored topic, and new studies are being undertaken to unravel their impact on the pathogenesis of mucositis. PMID:24456144

  12. Mucosal and systemic adjuvant activity of alphavirus replicon particles

    NASA Astrophysics Data System (ADS)

    Thompson, Joseph M.; Whitmore, Alan C.; Konopka, Jennifer L.; Collier, Martha L.; Richmond, Erin M. B.; Davis, Nancy L.; Staats, Herman F.; Johnston, Robert E.

    2006-03-01

    Vaccination represents the most effective control measure in the fight against infectious diseases. Local mucosal immune responses are critical for protection from, and resolution of, infection by numerous mucosal pathogens. Antigen processing across mucosal surfaces is the natural route by which mucosal immunity is generated, as peripheral antigen delivery typically fails to induce mucosal immune responses. However, we demonstrate in this article that mucosal immune responses are evident at multiple mucosal surfaces after parenteral delivery of Venezuelan equine encephalitis virus replicon particles (VRP). Moreover, coinoculation of null VRP (not expressing any transgene) with inactivated influenza virions, or ovalbumin, resulted in a significant increase in antigen-specific systemic IgG and fecal IgA antibodies, compared with antigen alone. Pretreatment of VRP with UV light largely abrogated this adjuvant effect. These results demonstrate that alphavirus replicon particles possess intrinsic systemic and mucosal adjuvant activity and suggest that VRP RNA replication is the trigger for this activity. We feel that these observations and the continued experimentation they stimulate will ultimately define the specific components of an alternative pathway for the induction of mucosal immunity, and if the activity is evident in humans, will enable new possibilities for safe and inexpensive subunit and inactivated vaccines. vaccine vector | Venezuelan equine encephalitis virus | viral immunology | RNA virus

  13. CAD system for automatic analysis of CT perfusion maps

    NASA Astrophysics Data System (ADS)

    Hachaj, T.; Ogiela, M. R.

    2011-03-01

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

  14. Active skin perfusion and thermoregulatory response in the hand following nerve injury and repair in human upper extremities.

    PubMed

    Deng, Aidong; Liu, Dan; Gu, Chen; Gu, Xiaosong; Gu, Jianhui; Hu, Wen

    2016-01-01

    Cutaneous vasoconstriction/vasodilatation occurs in response to whole body and local cooling/heating, and the vasomotor activities play a pivotal role in thermal control of the human body. The mechanisms underlying regulation of skin blood flow involve both neurogenic and humeral/local chemical influence, contributing to the initial response to thermal stimuli and the prolonged phase of response, respectively. Previous studies have suggested the impairment of cutaneous thermal regulation after nerve injury. However, the evidence regarding how the skin perfusion and thermoregulatory response evolve after nerve injury and repair remains limited. Here we observed, by utilizing laser-Doppler perfusion imaging, baseline skin perfusion and perfusion change in response to thermal stimuli after median and ulnar nerve injury, and the results showed that baseline perfusion in autonomous skin area profoundly decreased and active rewarming after clod stress dramatically diminished before sensory recovery of the skin became detectable. In addition, baseline cutaneous perfusion was recovered as the skin regained touch sensation, and exhibited positive correlation to touch sensibility of the skin. These data indicate that both active perfusion and thermoregulatory response of the skin are markedly compromised during skin denervation and can be recovered by re-innervation. This suggests the importance of timely repair of injured nerve, especially in the practice of replantation. PMID:26529641

  15. Modeling laser speckle imaging of perfusion in the skin (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Regan, Caitlin; Hayakawa, Carole K.; Choi, Bernard

    2016-02-01

    Laser speckle imaging (LSI) enables visualization of relative blood flow and perfusion in the skin. It is frequently applied to monitor treatment of vascular malformations such as port wine stain birthmarks, and measure changes in perfusion due to peripheral vascular disease. We developed a computational Monte Carlo simulation of laser speckle contrast imaging to quantify how tissue optical properties, blood vessel depths and speeds, and tissue perfusion affect speckle contrast values originating from coherent excitation. The simulated tissue geometry consisted of multiple layers to simulate the skin, or incorporated an inclusion such as a vessel or tumor at different depths. Our simulation used a 30x30mm uniform flat light source to optically excite the region of interest in our sample to better mimic wide-field imaging. We used our model to simulate how dynamically scattered photons from a buried blood vessel affect speckle contrast at different lateral distances (0-1mm) away from the vessel, and how these speckle contrast changes vary with depth (0-1mm) and flow speed (0-10mm/s). We applied the model to simulate perfusion in the skin, and observed how different optical properties, such as epidermal melanin concentration (1%-50%) affected speckle contrast. We simulated perfusion during a systolic forearm occlusion and found that contrast decreased by 35% (exposure time = 10ms). Monte Carlo simulations of laser speckle contrast give us a tool to quantify what regions of the skin are probed with laser speckle imaging, and measure how the tissue optical properties and blood flow affect the resulting images.

  16. TISSUE ENGINEERING PERFUSABLE CANCER MODELS

    PubMed Central

    Fong, E.L.; Santoro, M.; Farach-Carson, M.C.; Kasper, F.K.; Mikos, A.G.

    2014-01-01

    The effect of fluid flow on cancer progression is currently not well understood, highlighting the need for perfused tumor models to close this gap in knowledge. Enabling biological processes at the cellular level to be modeled with high spatiotemporal control, microfluidic tumor models have demonstrated applicability as platforms to study cell-cell interactions, effect of interstitial flow on tumor migration and the role of vascular barrier function. To account for the multi-scale nature of cancer growth and invasion, macroscale models are also necessary. The consideration of fluid dynamics within tumor models at both the micro- and macroscopic levels may greatly improve our ability to more fully mimic the tumor microenvironment. PMID:24634812

  17. A comparative analysis of the dependences of the hemodynamic parameters on changes in ROI's position in perfusion CT scans

    NASA Astrophysics Data System (ADS)

    Choi, Yong-Seok; Cho, Jae-Hwan; Namgung, Jang-Sun; Kim, Hyo-Jin; Yoon, Dae-Young; Lee, Han-Joo

    2013-05-01

    This study performed a comparative analysis of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and mean time-to-peak (TTP) obtained by changing the region of interest's (ROI) anatomical positions, during CT brain perfusion. We acquired axial source images of perfusion CT from 20 patients undergoing CT perfusion exams due to brain trauma. Subsequently, the CBV, CBF, MTT, and TTP values were calculated through data-processing of the perfusion CT images. The color scales for the CBV, CBF, MTT, and TTP maps were obtained using the image data. Anterior cerebral artery (ACA) was taken as the standard ROI for the calculations of the perfusion values. Differences in the hemodynamic average values were compared in a quantitative analysis by placing ROI and the dividing axial images into proximal, middle, and distal segments anatomically. By performing the qualitative analysis using a blind test, we observed changes in the sensory characteristics by using the color scales of the CBV, CBF, and MTT maps in the proximal, middle, and distal segments. According to the qualitative analysis, no differences were found in CBV, CBF, MTT, and TTP values of the proximal, middle, and distal segments and no changes were detected in the color scales of the the CBV, CBF, MTT, and TTP maps in the proximal, middle, and distal segments. We anticipate that the results of the study will useful in assessing brain trauma patients using by perfusion imaging.

  18. Supra-plasma expanders: the future of treating blood loss and anemia without red cell transfusions?

    PubMed

    Tsai, Amy G; Vázquez, Beatriz Y Salazar; Hofmann, Axel; Acharya, Seetharama A; Intaglietta, Marcos

    2015-01-01

    Oxygen delivery capacity during profoundly anemic conditions depends on blood's oxygen-carrying capacity and cardiac output. Oxygen-carrying blood substitutes and blood transfusion augment oxygen-carrying capacity, but both have given rise to safety concerns, and their efficacy remains unresolved. Anemia decreases oxygen-carrying capacity and blood viscosity. Present studies show that correcting the decrease of blood viscosity by increasing plasma viscosity with newly developed plasma expanders significantly improves tissue perfusion. These new plasma expanders promote tissue perfusion, increasing oxygen delivery capacity without increasing blood oxygen-carrying capacity, thus treating the effects of anemia while avoiding the transfusion of blood. PMID:25871869

  19. Rapid casting of patterned vascular networks for perfusable engineered three-dimensional tissues

    NASA Astrophysics Data System (ADS)

    Miller, Jordan S.; Stevens, Kelly R.; Yang, Michael T.; Baker, Brendon M.; Nguyen, Duc-Huy T.; Cohen, Daniel M.; Toro, Esteban; Chen, Alice A.; Galie, Peter A.; Yu, Xiang; Chaturvedi, Ritika; Bhatia, Sangeeta N.; Chen, Christopher S.

    2012-09-01

    In the absence of perfusable vascular networks, three-dimensional (3D) engineered tissues densely populated with cells quickly develop a necrotic core. Yet the lack of a general approach to rapidly construct such networks remains a major challenge for 3D tissue culture. Here, we printed rigid 3D filament networks of carbohydrate glass, and used them as a cytocompatible sacrificial template in engineered tissues containing living cells to generate cylindrical networks that could be lined with endothelial cells and perfused with blood under high-pressure pulsatile flow. Because this simple vascular casting approach allows independent control of network geometry, endothelialization and extravascular tissue, it is compatible with a wide variety of cell types, synthetic and natural extracellular matrices, and crosslinking strategies. We also demonstrated that the perfused vascular channels sustained the metabolic function of primary rat hepatocytes in engineered tissue constructs that otherwise exhibited suppressed function in their core.

  20. Optimization of perfusion CT protocol for imaging of extracranial head and neck tumors.

    PubMed

    Bisdas, Sotirios; Foo, Chuan Zhi; Thng, Choon Hua; Vogl, Thomas J; Koh, Tong San

    2009-10-01

    The in vivo assessment of physiological processes associated with microcirculation in the head and neck tissue by means of perfusion computed tomography is widely used in the management of patients with head and neck tumors. However, there is no systematic consideration of the total acquisition duration and placement of the scans. A simulation study for optimizing perfusion studies of extracranial head and neck tumors, with considerations of reducing radiation dose while maintaining accuracy of the perfusion parameters, is demonstrated here. The suggested that dual-phase optimized protocols may provide reliable estimations of the permeability surface area product as well as blood flow and volume without additional radiation burden and serious patient discomfort. These optimized protocols can potentially be useful in the clinical setting of examining patients with extracranial head and neck tumors. PMID:18454289

  1. Dependence of Brain Intravoxel Incoherent Motion Perfusion Parameters on the Cardiac Cycle

    PubMed Central

    Federau, Christian; Hagmann, Patric; Maeder, Philippe; Müller, Markus; Meuli, Reto; Stuber, Matthias; O’Brien, Kieran

    2013-01-01

    Measurement of microvascular perfusion with Intravoxel Incoherent Motion (IVIM) MRI is gaining interest. Yet, the physiological influences on the IVIM perfusion parameters (“pseudo-diffusion” coefficient D*, perfusion fraction f, and flow related parameter fD*) remain insufficiently characterized. In this article, we hypothesize that D* and fD*, which depend on blood speed, should vary during the cardiac cycle. We extended the IVIM model to include time dependence of D* = D*(t), and demonstrate in the healthy human brain that both parameters D* and fD* are significantly larger during systole than diastole, while the diffusion coefficient D and f do not vary significantly. The results non-invasively demonstrate the pulsatility of the brain’s microvasculature. PMID:24023649

  2. Topical protection of human esophageal mucosal integrity.

    PubMed

    Woodland, P; Batista-Lima, F; Lee, C; Preston, S L; Dettmar, P; Sifrim, D

    2015-06-15

    Patients with nonerosive reflux disease exhibit impaired esophageal mucosal integrity, which may underlie enhanced reflux perception. In vitro topical application of an alginate solution can protect mucosal biopsies against acid-induced changes in transepithelial electrical resistance (TER). We aimed to confirm this finding in a second model using 3D cell cultures and to assess prolonged protection in a biopsy model. We assessed the protective effect of a topically applied alginate solution 1 h after application. 3D cell cultures were grown by using an air-liquid interface and were studied in Ussing chambers. The apical surface was "protected" with 200 μl of either alginate or viscous control or was unprotected. The tissue was exposed to pH 3 + bile acid solution for 30 min and TER change was calculated. Distal esophageal mucosal biopsies were taken from 12 patients and studied in Ussing chambers. The biopsies were coated with either alginate or viscous control solution. The biopsies were then bathed in pH 7.4 solution for 1 h. The luminal chamber solution was replaced with pH 2 solution for 30 min. Percentage changes in TER were recorded. In five biopsies fluorescein-labeled alginate solution was used to allow immunohistological localization of the alginate after 1 h. In the cell culture model, alginate solution protected tissue against acid-induced change in TER. In biopsies, 60 min after protection with alginate solution, the acidic exposure caused a -8.3 ± 2.2% change in TER compared with -25.1 ± 4.5% change after protection with the viscous control (P < 0.05). Labeled alginate could be seen coating the luminal surface in all cases. In vitro, alginate solutions can adhere to the esophageal mucosa for up to 1 h and exert a topical protectant effect. Durable topical protectants can be further explored as first-line/add-on therapies for gastroesophageal reflux disease. PMID:25907692

  3. Multiscale modeling of mucosal immune responses

    PubMed Central

    2015-01-01

    Computational modeling techniques are playing increasingly important roles in advancing a systems-level mechanistic understanding of biological processes. Computer simulations guide and underpin experimental and clinical efforts. This study presents ENteric Immune Simulator (ENISI), a multiscale modeling tool for modeling the mucosal immune responses. ENISI's modeling environment can simulate in silico experiments from molecular signaling pathways to tissue level events such as tissue lesion formation. ENISI's architecture integrates multiple modeling technologies including ABM (agent-based modeling), ODE (ordinary differential equations), SDE (stochastic modeling equations), and PDE (partial differential equations). This paper focuses on the implementation and developmental challenges of ENISI. A multiscale model of mucosal immune responses during colonic inflammation, including CD4+ T cell differentiation and tissue level cell-cell interactions was developed to illustrate the capabilities, power and scope of ENISI MSM. Background Computational techniques are becoming increasingly powerful and modeling tools for biological systems are of greater needs. Biological systems are inherently multiscale, from molecules to tissues and from nano-seconds to a lifespan of several years or decades. ENISI MSM integrates multiple modeling technologies to understand immunological processes from signaling pathways within cells to lesion formation at the tissue level. This paper examines and summarizes the technical details of ENISI, from its initial version to its latest cutting-edge implementation. Implementation Object-oriented programming approach is adopted to develop a suite of tools based on ENISI. Multiple modeling technologies are integrated to visualize tissues, cells as well as proteins; furthermore, performance matching between the scales is addressed. Conclusion We used ENISI MSM for developing predictive multiscale models of the mucosal immune system during gut

  4. Research controversies in management of oral mucositis.

    PubMed

    Biron, P; Sebban, C; Gourmet, R; Chvetzoff, G; Philip, I; Blay, J Y

    2000-01-01

    The management of mucositis is the subject of many controversies, and the optimal treatment is still not known. Several evaluation scoring systems have been described, but no one of these is appropriate to all clinical situations: a simple scale such as that devised by the WHO can be used routinely, and more sophisticated ones can be implemented by trained experimenters working in research. We have considered the impact of each of the treatments currently available on each stage of mucositis. In attempts at prevention, self-care, in the sense of oral hygiene, must remain atraumatic. It is probably advisable to differentiate patients with good previous oral care, in whom tooth brushing is beneficial, from others, in whom the risk of hemorrhage and infection excludes any brushing. Before the dosage of chemotherapy is reduced, the curative or palliative intent of the strategy must be carefully evaluated. In the vascular phase protection of the proliferating cells is attempted by means of vasoconstriction (cryotherapy), cytoprotection (prostaglandin E2 and other antioxidants) or epithelial cell-inhibiting factors such as TGF-B3. Treatments applied in the epithelial phase are directed at increasing the cell proliferation to accelerate epithelial restoration by sucralfate and several growth factors: hematopoietic GF, which has demonstrated a direct effect on the mucosa (GM-CSF), or epithelial growth factors such as keratinocyte GF. In the ulcerative and bacteriological phase attempts are made to attenuate sepsis by means of antiseptics (chlorhexidine), amphotericin B and antiviral agents or antibiotic lozenges. In the healing phase application of the low-energy helium-neon laser has demonstrably been followed by a later time of onset, less pronounced peak severity and shorter duration of oral mucositis. After cancer treatment, oral hygiene, inhibition of oral flora, and pain relief are the main goals. Physiopathogen-specific treatment is the next step, with the emphasis

  5. Gastric Mucosal Protection by Aegle Marmelos Against Gastric Mucosal Damage: Role of Enterochromaffin Cell and Serotonin

    PubMed Central

    Singh, Purnima; Dutta, Shubha R.; Guha, Debjani

    2015-01-01

    Background/Aims: Serotonin (5-hydroxytryptamine; 5-HT) released from enterochromaffin (EC) cells in gastric mucosa inhibits gastric acidity by increasing the gastric mucus secretion. In the present study, we evaluated the effect of aqueous extract of Aegle marmelos (AM) ripe fruit pulp (250 mg/kg body weight) on mean ulcer index (MUI), EC cells, 5-HT content, and adherent mucosal thickness of ulcerated gastric tissue in adult albino rats. Material and Methods: Ulceration was induced by using aspirin (500 mg/kg, p.o.), cerebellar nodular lesion and applying cold-restraint stress. Results: In all cases increased MUI in gastric tissue along with decreased EC cell count was observed with concomitant decrease of 5-HT content and adherent mucosal thickness (P < 0.05). Pretreatment with AM for 14 days decreased MUI, increased EC cell count, and 5-HT content as well as adherent mucosal thickness in all ulcerated group (P < 0.05). Conclusion: AM produces gastric mucosal protection mediated by increased EC cell count and 5-HT levels. PMID:25672237

  6. Evaluation of a suspicious oral mucosal lesion.

    PubMed

    Williams, P Michele; Poh, Catherine F; Hovan, Allan J; Ng, Samson; Rosin, Miriam P

    2008-04-01

    Dentists who encounter a change in the oral mucosa of a patient must decide whether the abnormality requires further investigation. In this paper, we describe a systematic approach to the assessment of oral mucosal conditions that are thought likely to be premalignant or an early cancer. These steps, which include a comprehensive history, step-by-step clinical examination (including use of adjunctive visual tools), diagnostic testing and formulation of diagnosis, are routinely used in clinics affiliated with the British Columbia Oral Cancer Prevention Program (BC OCPP) and are recommended for consideration by dentists for use in daily practice. PMID:18387268

  7. Peptic activity and gastroduodenal mucosal damage.

    PubMed Central

    Raufman, J. P.

    1996-01-01

    This contribution reviews briefly the history of the discovery and characterization of peptic activity; secretory models and current concepts regarding the regulation of pepsinogen secretion; and evidence that pepsin is a necessary co-factor for gastroduodenal mucosal injury. Several animal studies indicate that peptic activity is required for acid- and nonsteroidal anti-inflammatory drug-induced gastroduodenal ulceration. A more vigorous approach to the development of anti-peptic drugs for the treatment of peptic ulcer disease is encouraged. Images Figure 1 PMID:9041694

  8. Mucosal Lesions in an Allergy Practice.

    PubMed

    Kohorst, John J; Bruce, Alison J; Torgerson, Rochelle R

    2016-04-01

    The diagnosis and treatment of mucosal disease with an allergic pathogenesis are challenging. Oral allergy is often a hypersensitivity reaction with variable symptoms and physical exam findings. Clinical diagnosis requires a history of prior allergen exposure, a delay from exposure to clinical findings, and improvement following allergen removal. The past decades have seen great contributions to the field of oral allergy. The aim of this review is to provide an approach to the diagnosis and treatment of oral dermatologic disease with a focus on diseases with an investigated allergic pathogenesis. PMID:26922434

  9. Human Circulating Antibody-Producing B Cell as a Predictive Measure of Mucosal Immunity to Poliovirus

    PubMed Central

    Verma, Harish; Sharma, Prashant; Yang, Jae Seung; Saletti, Giulietta; Ahmad, Mohammad; Bahl, Sunil K.; Wierzba, Thomas F.; Nandy, Ranjan K.; Deshpande, Jagadish M.; Sutter, Roland W.; Czerkinsky, Cecil

    2016-01-01

    Background The “gold standard” for assessing mucosal immunity after vaccination with poliovirus vaccines consists in measuring virus excretion in stool after challenge with oral poliovirus vaccine (OPV). This testing is time and resource intensive, and development of alternative methods is a priority for accelerating polio eradication. We therefore evaluated circulating antibody-secreting cells (ASCs) as a potential means to evaluate mucosal immunity to poliovirus vaccine. Methods 199 subjects, aged 10 years, and previously immunized repeatedly with OPV, were selected. Subjects were assigned to receive either a booster dose of inactivated poliovirus vaccine (IPV), bivalent OPV (bOPV), or no vaccine. Using a micro-modified whole blood-based ELISPOT assay designed for field setting, circulating poliovirus type-specific IgA- and IgG-ASCs, including gut homing α4β7+ ASCs, were enumerated on days 0 and 7 after booster immunization. In addition, serum samples collected on days 0, 28 and 56 were tested for neutralizing antibody titers against poliovirus types 1, 2, and 3. Stool specimens were collected on day 28 (day of bOPV challenge), and on days 31, 35 and 42 and processed for poliovirus isolation. Results An IPV dose elicited blood IgA- and IgG-ASC responses in 84.8 to 94.9% of subjects, respectively. In comparison, a bOPV dose evoked corresponding blood ASC responses in 20.0 to 48.6% of subjects. A significant association was found between IgA- and IgG-ASC responses and serum neutralizing antibody titers for poliovirus type 1, 2, 3 (p<0.001). In the IPV group, α4β7+ ASCs accounted for a substantial proportion of IgA-ASCs and the proportion of subjects with a positive α4β7+ IgA-ASC response to poliovirus types 1, 2 and 3 was 62.7%, 89.8% and 45.8%, respectively. A significant association was observed between virus excretion and α4β7+ IgA- and/or IgG-ASC responses to poliovirus type 3 among immunized children; however, only a weak association was found for

  10. Cortical perfusion index: A predictor of acute rejection in transplanted kidneys

    SciTech Connect

    Atkins, H.L.; Oster, Z.H.; Anaise, D.; Wein, S.; Waltzer, W.; Gonder, A.; Cooch, E.; Rapaport, F.T.

    1985-05-01

    The presently available non-invasive methods for the diagnosis of acute rejection crisis (ARC) of renal transplants are not satisfactory. However, the need for such a test is of paramount clinical importance. A prospective study of 74 post-transplantation events in renal allograft recipients was performed. Clinical, surgical exploration and biopsy data were correlated with TC-99m DTPA scintigraphy using the following indices: Global perfusion index (GPI), cortical perfusion index (CPI), medullary perfusion index (MPI), the peak-to-plateau ratio (P/P), iliac artery peak to renal peak time (delta-P) and washout half-time (T1/2). Of the 74 events, 24 were proven to be due to acute rejection crisis (ARC), 13 were of ureteral obstruction, 18 various nephropathies and 19 in stable renal transplant function. The P/P, delta-P and T1/2 were not good predictors of ARC; the sensitivity was 79%, 79% and 80% respectively. The sensitivity of the GPI was 58% and the specificity was 87%. The cortical perfusion index rated better: specificity=84% and sensitivity=87%. However, the best indicator of ARC seemed to be the percent increase in cortical perfusion index over previous values obtained during stable graft function. Thus the sensitivity was found to be 91% and specificity was 96%. The difference between global and cortical perfusion indices reflects shunting of blood for cortex to medulla. This study suggest that the cortical perfusion index (CPI) and the percent increase in CPI can be used to non-invasively diagnose acute renal allograft rejection.

  11. Synergistic Effects of Hemoglobin and Tumor Perfusion on Tumor Control and Survival in Cervical Cancer

    SciTech Connect

    Mayr, Nina A. Wang, Jian Z.; Zhang Dongqing; Montebello, Joseph F.; Grecula, John C.; Lo, Simon S.; Fowler, Jeffery M.; Yuh, William T.C.

    2009-08-01

    Purpose: The tumor oxygenation status is likely influenced by two major factors: local tumor blood supply (tumor perfusion) and its systemic oxygen carrier, hemoglobin (Hgb). Each has been independently shown to affect the radiotherapy (RT) outcome in cervical cancer. This study assessed the effect of local tumor perfusion, systemic Hgb levels, and their combination on the treatment outcome in cervical cancer. Methods and Materials: A total of 88 patients with cervical cancer, Stage IB2-IVA, who were treated with RT/chemotherapy, underwent serial dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) before RT, at 20-22 Gy, and at 45-50 Gy. The DCE-MRI perfusion parameters, mean and lowest 10th percentile of the signal intensity distribution in the tumor pixels, and the Hgb levels, including pre-RT, nadir, and mean Hgb (average of weekly Hgb during RT), were correlated with local control and disease-specific survival. The median follow-up was 4.6 years. Results: Local recurrence predominated in the group with both a low mean Hgb (<11.2 g/dL) and low perfusion (lowest 10th percentile of signal intensity <2.0 at 20-22 Gy), with a 5-year local control rate of 60% vs. 90% for all other groups (p = .001) and a disease-specific survival rate of 41% vs. 72% (p = .008), respectively. In the group with both high mean Hgb and high perfusion, the 5-year local control rate and disease-specific survival rate was 100% and 78%, respectively. Conclusion: These results suggest that the compounded effects of Hgb level and tumor perfusion during RT influence the radioresponsiveness and survival in cervical cancer patients. The outcome was worst when both were impaired. The management of Hgb may be particularly important in patients with low tumor perfusion.

  12. Evaluation of Face Lift Skin Perfusion and Epinephrine Effect Using Laser Fluorescence Imaging

    PubMed Central

    2015-01-01

    Background: Face lift dissections are believed to compromise skin flap circulation, possibly leading to wound healing complications. To reduce blood loss, plastic surgeons commonly inject a solution of local anesthetic that contains epinephrine. However, the effect of surgery on skin perfusion and the degree of vasoconstriction caused by the epinephrine have not been quantitated. Little information is available to guide the selection of epinephrine concentration. Methods: Nine consecutive patients undergoing a deep-plane face lift were asked to participate in this prospective study. All patients consented (inclusion rate, 100%). The SPY Elite Intraoperative Perfusion System was used to quantitate perfusion. Measurements were made at 5 sites on both sides of the face and the neck. A nondissected temple site served as a reference. Three patients received no epinephrine in their local anesthetic solution, 3 patients received 1:800,000 epinephrine, and 3 patients were injected with 1:300,000 epinephrine. Results: All 9 patients were female nonsmokers. There was no reduction in skin perfusion measurements after surgery. In patients treated with 1:800,000 and 1:300,000 epinephrine, 4 sites showed significantly (P < 0.05) decreased perfusion compared with the no-epinephrine group. Combined perfusion data were almost 50% reduced, but the difference was nonsignificant, likely because of the small sample sizes. One patient developed a hematoma. Two of the 3 patients who received no epinephrine developed extensive bruising. Conclusions: A deep-plane face lift dissection does not impair skin flap perfusion. Both 1:300,000 epinephrine and 1:800,000 epinephrine concentrations are effective in producing intraoperative vasoconstriction. PMID:26495197

  13. Mucosal Imprinting of Vaccine-Induced CD8+ T Cells Is Crucial to Inhibit the Growth of Mucosal Tumors

    PubMed Central

    Sandoval, Federico; Bureau, Michel-Francis; Freyburger, Ludovic; Clement, Olivier; Marcheteau, Elie; Gey, Alain; Fraisse, Guillaume; Bouguin, Cécilia; Merillon, Nathalie; Dransart, Estelle; Tran, Thi; Quintin-Colonna, Françoise; Autret, Gwennhael; Thiebaud, Marine; Suleman, Muhammad; Riffault, Sabine; Wu, Tzyy-Choou; Launay, Odile; Danel, Claire; Taieb, Julien; Richardson, Jennifer; Zitvogel, Laurence; Fridman, Wolf H.; Johannes, Ludger; Tartour, Eric

    2014-01-01

    Although many human cancers are located in mucosal sites, most cancer vaccines are tested against subcutaneous tumors in preclinical models. We therefore wondered whether mucosa-specific homing instructions to the immune system might influence mucosal tumor outgrowth. We showed that the growth of orthotopic head and neck or lung cancers was inhibited when a cancer vaccine was delivered by the intranasal mucosal route but not the intramuscular route. This antitumor effect was dependent on CD8+ T cells. Indeed, only intranasal vaccination elicited mucosal-specific CD8+ T cells expressing the mucosal integrin CD49a. Blockade of CD49a decreased intratumoral CD8+ T cell infiltration and the efficacy of cancer vaccine on mucosal tumor. We then showed that after intranasal vaccination, dendritic cells from lung parenchyma, but not those from spleen, induced the expression of CD49a on cocultured specific CD8+ T cells. Tumor-infiltrating lymphocytes from human mucosal lung cancer also expressed CD49a, which supports the relevance and possible extrapolation of these results in humans. We thus identified a link between the route of vaccination and the induction of a mucosal homing program on induced CD8+ T cells that controlled their trafficking. Immunization route directly affected the efficacy of the cancer vaccine to control mucosal tumors. PMID:23408053

  14. Ventilation-perfusion imaging in pulmonary papillomatosis

    SciTech Connect

    Espinola, D.; Rupani, H.; Camargo, E.E.; Wagner, H.N. Jr.

    1981-11-01

    Three children with laryngeal papillomas involving the lungs had serial ventilation-perfusion scintigrams to assess results of therapy designed to reduce the bronchial involvement. Different imaging patterns were observed depending on size, number, and location of lesions. In early parenchymal involvement a ventilation-perfusion mismatch was seen. The initial and follow-up studies correlated well with clinical and radiographic findings. This noninvasive procedure is helpful in evaluating ventilatory and perfusion impairment in these patients as well as their response to treatment.

  15. Cochlear perfusion with a viscous fluid.

    PubMed

    Wang, Yi; Olson, Elizabeth S

    2016-07-01

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

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

    PubMed

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

    2016-06-01

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

  17. Quantification of myocardial perfusion based on signal intensity of flow sensitized MRI

    NASA Astrophysics Data System (ADS)

    Abeykoon, Sumeda B.

    The quantitative assessment of perfusion is important for early recognition of a variety of heart diseases, determination of disease severity and their cure. In conventional approach of measuring cardiac perfusion by arterial spin labeling, the relative difference in the apparent T1 relaxation times in response to selective and non-selective inversion of blood entering the region of interest is related to perfusion via a two-compartment tissue model. But accurate determination of T1 in small animal hearts is difficult and prone to errors due to long scan times. The purpose of this study is to develop a fast, robust and simple method to quantitatively assess myocardial perfusion using arterial spin labeling. The proposed method is based on signal intensities (SI) of inversion recovery slice-select, non-select and steady-state images. Especially in this method data are acquired at a single inversion time and at short repetition times. This study began by investigating the accuracy of assessment of perfusion using a two compartment system. First, determination of perfusion by T1 and SI were implemented to a simple, two-compartment phantom model. Mathematical model developed for full spin exchange models (in-vivo experiments) by solving a modified Bloch equation was modified to develop mathematical models (T1 and SI) for a phantom (zero spin exchange). The phantom result at different flow rates shows remarkable evidence of accuracy of the two-compartment model and SI, T1 methods: the SI method has less propagation error and less scan time. Next, twelve healthy C57BL/6 mice were scanned for quantitative perfusion assessment and three of them were repeatedly scanned at three different time points for a reproducibility test. The myocardial perfusion of healthy mice obtained by the SI-method, 5.7+/-1.6 ml/g/min, was similar (p=0.38) to that obtained by the conventional T1 method, 5.6+/- 2.3 ml/g/min. The reproducibility of the SI method shows acceptable results: the

  18. Renal blood flow and oxygenation drive nephron progenitor differentiation.

    PubMed

    Rymer, Christopher; Paredes, Jose; Halt, Kimmo; Schaefer, Caitlin; Wiersch, John; Zhang, Guangfeng; Potoka, Douglas; Vainio, Seppo; Gittes, George K; Bates, Carlton M; Sims-Lucas, Sunder

    2014-08-01

    During kidney development, the vasculature develops via both angiogenesis (branching from major vessels) and vasculogenesis (de novo vessel formation). The formation and perfusion of renal blood vessels are vastly understudied. In the present study, we investigated the regulatory role of renal blood flow and O2 concentration on nephron progenitor differentiation during ontogeny. To elucidate the presence of blood flow, ultrasound-guided intracardiac microinjection was performed, and FITC-tagged tomato lectin was perfused through the embryo. Kidneys were costained for the vasculature, ureteric epithelium, nephron progenitors, and nephron structures. We also analyzed nephron differentiation in normoxia compared with hypoxia. At embryonic day 13.5 (E13.5), the major vascular branches were perfused; however, smaller-caliber peripheral vessels remained unperfused. By E15.5, peripheral vessels started to be perfused as well as glomeruli. While the interior kidney vessels were perfused, the peripheral vessels (nephrogenic zone) remained unperfused. Directly adjacent and internal to the nephrogenic zone, we found differentiated nephron structures surrounded and infiltrated by perfused vessels. Furthermore, we determined that at low O2 concentration, little nephron progenitor differentiation was observed; at higher O2 concentrations, more differentiation of the nephron progenitors was induced. The formation of the developing renal vessels occurs before the onset of blood flow. Furthermore, renal blood flow and oxygenation are critical for nephron progenitor differentiation. PMID:24920757

  19. Renal blood flow and oxygenation drive nephron progenitor differentiation

    PubMed Central

    Rymer, Christopher; Paredes, Jose; Halt, Kimmo; Schaefer, Caitlin; Wiersch, John; Zhang, Guangfeng; Potoka, Douglas; Vainio, Seppo; Gittes, George K.; Bates, Carlton M.

    2014-01-01

    During kidney development, the vasculature develops via both angiogenesis (branching from major vessels) and vasculogenesis (de novo vessel formation). The formation and perfusion of renal blood vessels are vastly understudied. In the present study, we investigated the regulatory role of renal blood flow and O2 concentration on nephron progenitor differentiation during ontogeny. To elucidate the presence of blood flow, ultrasound-guided intracardiac microinjection was performed, and FITC-tagged tomato lectin was perfused through the embryo. Kidneys were costained for the vasculature, ureteric epithelium, nephron progenitors, and nephron structures. We also analyzed nephron differentiation in normoxia compared with hypoxia. At embryonic day 13.5 (E13.5), the major vascular branches were perfused; however, smaller-caliber peripheral vessels remained unperfused. By E15.5, peripheral vessels started to be perfused as well as glomeruli. While the interior kidney vessels were perfused, the peripheral vessels (nephrogenic zone) remained unperfused. Directly adjacent and internal to the nephrogenic zone, we found differentiated nephron structures surrounded and infiltrated by perfused vessels. Furthermore, we determined that at low O2 concentration, little nephron progenitor differentiation was observed; at higher O2 concentrations, more differentiation of the nephron progenitors was induced. The formation of the developing renal vessels occurs before the onset of blood flow. Furthermore, renal blood flow and oxygenation are critical for nephron progenitor differentiation. PMID:24920757

  20. Repeatability and reproducibility of optic nerve head perfusion measurements using optical coherence tomography angiography

    NASA Astrophysics Data System (ADS)

    Chen, Chieh-Li; Bojikian, Karine D.; Xin, Chen; Wen, Joanne C.; Gupta, Divakar; Zhang, Qinqin; Mudumbai, Raghu C.; Johnstone, Murray A.; Chen, Philip P.; Wang, Ruikang K.

    2016-06-01

    Optical coherence tomography angiography (OCTA) has increasingly become a clinically useful technique in ophthalmic imaging. We evaluate the repeatability and reproducibility of blood perfusion in the optic nerve head (ONH) measured using optical microangiography (OMAG)-based OCTA. Ten eyes from 10 healthy volunteers are recruited and scanned three times with a 68-kHz Cirrus HD-OCT 5000-based OMAG prototype system (Carl Zeiss Meditec Inc., Dublin, California) centered at the ONH involving two separate visits within six weeks. Vascular images are generated with OMAG processing by detecting the differences in OCT signals between consecutive B-scans acquired at the same retina location. ONH perfusion is quantified as flux, vessel area density, and normalized flux within the ONH for the prelaminar, lamina cribrosa, and the full ONH. Coefficient of variation (CV) and intraclass correlation coefficient (ICC) are used to evaluate intravisit and intervisit repeatability, and interobserver reproducibility. ONH perfusion measurements show high repeatability [CV≤3.7% (intravisit) and ≤5.2% (intervisit)] and interobserver reproducibility (ICC≤0.966) in all three layers by three metrics. OCTA provides a noninvasive method to visualize and quantify ONH perfusion in human eyes with excellent repeatability and reproducibility, which may add additional insight into ONH perfusion in clinical practice.

  1. Self-driven perfusion culture system using a paper-based double-layered scaffold.

    PubMed

    Ozaki, Ai; Arisaka, Yoshinori; Takeda, Naoya

    2016-01-01

    Shear stress caused by fluid flow is known to promote tissue development from cells in vivo. Therefore, perfusion cultures have been studied to investigate the mechanisms involved and to fabricate engineered tissues in vitro, particularly those that include blood vessels. Microfluidic devices, which function with fine machinery of chambers and microsyringes for fluid flow and have small culture areas, are conventionally used for perfusion culture. In contrast, we have developed a self-driven perfusion culture system by using a paper-based double-layered scaffold as the fundamental component. Gelatin microfibers were electrospun onto a paper material to prepare the scaffold system, in which the constant perfusion of the medium and the scaffold for cell adhesion/proliferation were functionally divided into a paper and a gelatin microfiber layer, respectively. By applying both the capillary action and siphon phenomenon of the paper-based scaffold, which bridged two medium chambers at different height levels, a self-driven medium flow was achieved and the flow rate was also stable, constant, and quantitatively controllable. Moreover, the culture area was enlargeable to the cm(2) scale. The endothelial cells cultivated on this system oriented along the medium-flow direction, suggesting that the shear stress caused by medium flow was effectively applied. This perfusion culture system is expected to be useful for fabricating three-dimensional and large engineered tissues in the future. PMID:27550929

  2. Tissue distribution of oxacillin and ampicillin in the isolated perfused bovine udder.

    PubMed

    Ehinger, A M; Kietzmann, M

    2000-04-01

    In vivo, tissue distribution of intra-mammarily administered antibiotics is mostly only assessed by sampling milk and blood. Therefore, the described study analysed whether measurement of tissue concentrations makes sense in vitro instead. Isolated bovine udders were perfused with gassed and warmed Tyrode solution. To four front and rear quarters each, 1000 mg oxacillin in 7.5 ml vehicle was administered intracisternally, completely formulated as sodium monohydrate in two lactation ointments (with or without sodium dodecylsulphate) or 80% as benzathine salt in a dry-off ointment. Over 3 h, perfusate and glandular tissue from different locations were sampled and analysed by high pressure liquid chromatography. With increasing vertical distance to the teat base, the tissue concentration of antibiotics decreased. With the lactation ointment containing sodium dodecylsulphate, lower oxacillin concentrations were reached in glandular tissue and lymph nodes compared to those without. The ointments led to a higher recovery of oxacillin in glandular tissue than in perfusate. Aluminium monostearate in the dry-off ointment caused an even poorer absorption of oxacillin into perfusate. The isolated perfused bovine udder is suitable to study the tissue distribution of antibiotics, since the results were mainly comparable with the few existing in vivo studies and show the influence of different formulations. PMID:10842465

  3. Changes in lung composition and regional perfusion and tissue distribution in patients with ARDS

    PubMed Central

    Dakin, Jonathan; Jones, Andrew T; Hansell, David M; Hoffman, Eric A; Evans, Timothy W

    2011-01-01

    Background & objective ARDS is characterised by bilateral pulmonary infiltrates and refractory hypoxemia attributed to V/Q mismatch. We used dynamic CT to characterise changes in lung composition, regional perfusion and tissue distribution in patients with ARDS in comparison to healthy subjects. Methods The Fick principle was applied to serial attenuation measurements constructed from sequential CT images acquired during the passage of a bolus of iodinated contrast medium in healthy subjects (n=3) and patients with ARDS (n=11). Perfusion was calculated by the Mullani-Gould method and mapped throughout both lungs. Gradients of perfusion and tissue density against vertical height were constructed. Results In comparison to normal individuals, the tissue component of lungs from patients with ARDS was significantly increased (p<0.05). Blood fraction was unchanged. There was a discernable gradient in tissue density from non dependent to dependent regions in the patients with ARDS that was significantly different from controls. The proportion of perfusion applied to consolidated areas (ie shunt) correlated significantly (p<0.05) with the severity of hypoxaemia. Conclusions In patients with ARDS there are changes in both lung composition and the distribution of tissue and perfusion that may account in part for the physiological changes that define the syndrome. PMID:21883676

  4. Designer blood vessels and therapeutic revascularization

    PubMed Central

    Berglund, Joseph D; Galis, Zorina S

    2003-01-01

    Inadequate vascular perfusion leads to fatal heart attacks, chronic ulcers, and other serious clinical conditions. The body's capacity to restore vascular perfusion through angiogenesis and arteriogenesis is often impaired by pre-existing disease, and availability of native replacements for nonfunctional arteries is limited in many patients. Thus, recreating blood vessels of various calibres through novel engineering technologies has emerged as a radical option among therapeutic strategies for revascularization. Ranging from artificial, recycled or reassembled natural conduits to sophisticated microdevices, we refer to these as ‘designer blood vessels'. Our common efforts to continuously improve vascular replacement design have provided many clues about our own blood vessels, but nature's ability to create nonthrombogenic, immunocompatible, strong, yet biologically responsive blood vessels remains unparalleled. Just as art reproductions never equal the original masterpiece, designer blood vessels may never attain nature's perfection. Nevertheless, they will provide a valuable option as long as they come close enough and are available to many. PMID:14534146

  5. Blood Disorders

    MedlinePlus

    ... and protein. Over half of your blood is plasma. The solid part of your blood contains red blood cells, white blood cells and platelets. Blood disorders affect one or more parts of the blood and prevent ...

  6. Gastrointestinal mucosal barrier function and diseases.

    PubMed

    Oshima, Tadayuki; Miwa, Hiroto

    2016-08-01

    The gastrointestinal mucosal barrier plays an essential role in the separation of the inside of the body from the outside environment. Tight junctions (TJs) are the most important component for construction of a constitutive barrier of epithelial cells, and they regulate the permeability of the barrier by tightly sealing the cell-cell junctions. TJ proteins are represented by claudins, occludin, junctional adhesion molecules, and scaffold protein zonula occludens. Among these TJ proteins, claudins are the major components of TJs and are responsible for the barrier and the polarity of the epithelial cells. Gastrointestinal diseases including reflux esophagitis, inflammatory bowel disease, functional gastrointestinal disorders, and cancers may be regulated by these molecules, and disruption of their functions leads to chronic inflammatory conditions and chronic or progressive disease. Therefore, regulation of the barrier function of epithelial cells by regulating the expression and localization of TJ proteins is a potential new target for the treatment of these diseases. Treatment strategies for these diseases might thus be largely altered if symptom generation and/or immune dysfunction could be regulated through improvement of mucosal barrier function. Since TJ proteins may also modify tumor infiltration and metastasis, other important goals include finding a good TJ biomarker of cancer progression and patient prognosis, and developing TJ protein-targeted therapies that can modify patient prognosis. This review summarizes current understanding of gastrointestinal barrier function, TJ protein expression, and the mechanisms underlying epithelial barrier dysregulation in gastrointestinal diseases. PMID:27048502

  7. Canine oral mucosal mast cell tumours.

    PubMed

    Elliott, J W; Cripps, P; Blackwood, L; Berlato, D; Murphy, S; Grant, I A

    2016-03-01

    Mast cell tumours (MCTs) are the most common cutaneous tumours of dogs, however rarely they can arise from the oral mucosa. This subset of MCT is reported to demonstrate a more aggressive clinical course than those tumours on the haired skin and the authors hypothesised that dogs with oral, mucosal MCT would have a high incidence of local lymph node metastasis at presentation and that this would be a negative prognostic factor. An additional hypothesis was that mitotic index (MI) would be prognostic. This retrospective study examines 33 dogs with MCTs arising from the oral mucosa. The results suggest that oral mucosal MCTs in the dog have a high incidence of lymph node metastasis at diagnosis (55%) which results in a poor prognosis. MI and nodal metastasis is highly prognostic. Loco-regional progression is common in these patients and dogs with adequate local control of their tumour had an improved outcome. Despite a more aggressive clinical course, treatment can result in protracted survivals, even when metastasis is present. PMID:24215587

  8. Optic nerve head perfusion in normal eyes and eyes with glaucoma using optical coherence tomography-based microangiography

    PubMed Central

    Chen, Chieh-Li; Bojikian, Karine D.; Gupta, Divakar; Wen, Joanne C.; Zhang, Qinqin; Xin, Chen; Kono, Rei; Mudumbai, Raghu C.; Johnstone, Murray A.; Chen, Philip P.

    2016-01-01

    Background To investigate the differences of perfusion in the optic nerve head (ONH) between normal and glaucomatous eyes using optical microangiography (OMAG) based optical coherence tomography (OCT) angiography technique. Methods One eye from each subject was scanned with a 68 kHz Cirrus 5000 HD-OCT-based OMAG prototype system centered at the ONH (Carl Zeiss Meditec Inc, Dublin, CA, USA). Microvascular images were generated from the OMAG dataset by detecting the differences in OCT signal between consecutive B-scans. The pre-laminar layer (preLC) was isolated by a semi-automatic segmentation program. En face OMAG images for preLC were generated using signals with highest blood flow signal intensity. ONH perfusion was quantified as flux, vessel area density, and normalized flux within the ONH. Standard t-tests were performed to analyze the ONH perfusion differences between normal and glaucomatous eyes. Linear regression models were constructed to analyze the correlation between ONH perfusion and other clinical measurements. Results Twenty normal and 21 glaucoma subjects were enrolled. Glaucomatous eyes had significantly lower ONH perfusion in preLC in all three perfusion metrics compared to normal eyes (P≤0.0003). Significant correlations between ONH perfusion and disease severity as well as structural changes were detected in glaucomatous eyes (P≤0.012). Conclusions ONH perfusion detected by OMAG showed significant differences between glaucoma and normal controls and was significantly correlated with disease severity and structural defects in glaucomatous eyes. ONH perfusion measurement using OMAG may provide useful information for detection and monitoring of glaucoma. PMID:27190764

  9. Isolated total lung perfusion as a means to deliver organ-specific chemotherapy: long-term studies in animals

    SciTech Connect

    Johnston, M.R.; Christensen, C.W.; Minchin, R.F.; Rickaby, D.A.; Linehan, J.H.; Schuller, H.M.; Boyd, M.R.; Dawson, C.A.

    1985-07-01

    The objectives of this study were to develop a surgical procedure that would allow for bilateral isolated lung perfusion in vivo as a means of delivering organ-specific chemotherapy and to evaluate the influence of the procedure on certain pulmonary physiologic parameters. The sterile surgical procedure that was carried out in dogs involved the setting up of two separate perfusion circuits. Once standard systemic cardiopulmonary bypass was established, a second circuit was devised to perfuse the lungs by placing an inflow cannula into the main pulmonary artery and collecting venous effluent in the left atrium. Cross-contamination between perfusion circuits was determined in acute studies with labeled plasma protein or red blood cells and was found to be in an acceptable range if the aorta was cross-clamped and the heart arrested. Only about 0.4 ml/min of pulmonary perfusate leaked into the systemic circulation, indicating that systemic toxicity should not be a major concern when chemotherapy agents are added to the pulmonary perfusate. Chronic studies demonstrated that hemodynamic parameters, lung water, pulmonary endothelial serotonin extraction, and histologic findings all showed minimal changes after 50 minutes of isolated lung perfusion. Five days after perfusion, lung dynamic compliance and peak serotonin extraction showed significant decreases. However, all of the measured parameters had returned toward baseline levels by the end of the 8-week postoperative study period. The procedure offers significant advantages over the previously described single lung perfusion and may provide a method of delivering immediate high-concentration adjuvant chemotherapy to coincide with resection of primary or metastatic lung tumors.

  10. Amelioration of Chemotherapy-Induced Intestinal Mucositis by Orally Administered Probiotics in a Mouse Model

    PubMed Central

    Jiang, Chun-Bin; Cheng, Mei-Lien; Liu, Chia-Yuan; Chang, Szu-Wen; Chiang Chiau, Jen-Shiu; Lee, Hung-Chang

    2015-01-01

    Background and Aims Intestinal mucositis is a frequently encountered side effect in oncology patients undergoing chemotherapy. No well-established or up to date therapeutic strategies are available. To study a novel way to alleviate mucositis, we investigate the effects and safety of probiotic supplementation in ameliorating 5-FU-induced intestinal mucositis in a mouse model. Methods Seventy-two mice were injected saline or 5-Fluorouracil (5-FU) intraperitoneally daily. Mice were either orally administrated daily saline, probiotic suspension of Lactobacillus casei variety rhamnosus (Lcr35) or Lactobacillus acidophilus and Bifidobacterium bifidum (LaBi). Diarrhea score, pro-inflammatory cytokines serum levels, intestinal villus height and crypt depth and total RNA from tissue were assessed. Samples of blood, liver and spleen tissues were assessed for translocation. Results Marked diarrhea developed in the 5-FU groups but was attenuated after oral Lcr35 and LaBi administrations. Diarrhea scores decreased significantly from 2.64 to 1.45 and 0.80, respectively (P<0.001). Those mice in 5-FU groups had significantly higher proinflammatory cytokine levels (TNF-α: 234.80 vs. 29.10, P<0.001, IL-6: 25.13 vs. 7.43, P<0.001, IFN-γ: 22.07 vs. 17.06, P = 0.137). A repairing of damage in jejunal villi was observed following probiotics administration. We also found TNF-α, IL-1β and IL-6 mRNA expressions were up-regulated in intestinal mucositis tissues following 5-FU treatment (TNF-α: 4.35 vs. 1.18, IL-1β: 2.29 vs. 1.07, IL-6: 1.49 vs. 1.02) and that probiotics treatment suppressed this up-regulation (P<0.05). No bacterial translocation was found in this study. Conclusions In conclusion, our results show that oral administration of probiotics Lcr35 and LaBi can ameliorate chemotherapy-induced intestinal mucositis in a mouse model. This suggests probiotics may serve as an alternative therapeutic strategy for the prevention or management of chemotherapy-induced mucositis in

  11. Luminal distension as a possible consequence of experimental intestinal perfusion

    PubMed Central

    Wingate, David; Hyams, Ashley; Phillips, Sidney

    1974-01-01

    In an experimental jejunal perfusion study, distress in healthy subjects occurred during eight out of 16 perfusions in which intestinal secretion was provoked. Calculation demonstrates the volumetric consequences of inadequate recovery of secretory perfusates, and analysis of the perfusion studies shows that distress was significantly associated with poor recovery of the perfusate. These observations are pertinent to increasing interest in the phenomenon of intestinal fluid secretion. PMID:4435588

  12. Comparison of Two Algorithms for Analysis of Perfusion Computed Tomography Data for Evaluation of Cerebral Microcirculation in Chronic Subdural Hematoma.

    PubMed

    Trofimov, Alexey O; Kalentiev, George; Voennov, Oleg; Yuriev, Michail; Agarkova, Darya; Trofimova, Svetlana; Bragin, Denis E

    2016-01-01

    The aim of this work was comparison of two algorithms of perfusion computed tomography (PCT) data analysis for evaluation of cerebral microcirculation in the perifocal zone of chronic subdural hematoma (CSDH). Twenty patients with CSDH after polytrauma were included in the study. The same PCT data were assessed quantitatively in cortical brain region beneath the CSDH (zone 1), and in the corresponding contralateral brain hemisphere (zone 2) without and with the use of perfusion calculation mode excluding vascular pixel 'Remote Vessels' (RV); 1st and 2nd analysis method, respectively. Comparison with normal values for perfusion indices in the zone 1 in the 1st analysis method showed a significant (p < 0.01) increase in CBV and CBF, and no significant increase in MTT and TTP. Use of the RV mode (2nd analysis method) showed no statistically reliable change of perfusion parameters in the microcirculatory blood flow of the 2nd zone. Maintenance of microcirculatory blood flow perfusion reflects the preservation of cerebral blood flow autoregulation in patients with CSDH. PMID:27526170

  13. 1H nuclear magnetic resonance studies of sarcoplasmic oxygenation in the red cell-perfused rat heart.

    PubMed

    Jelicks, L A; Wittenberg, B A

    1995-05-01

    The proximal histidine N delta H proton of deoxymyoglobin experiences a large hyperfine shift resulting in its 1H nuclear magnetic resonance (NMR) signal appearing at approximately 76 ppm (at 35 degrees C), downfield of the diamagnetic spectral region. 1H NMR of this proton is used to monitor sarcoplasmic oxygen pressure in isolated perfused rat heart. This method monitors intracellular oxygenation in the whole heart and does not reflect oxygenation in a limited region. The deoxymyoglobin resonance intensity is reduced upon conversion of myoglobin to the ferric form by sodium nitrite. 1H resonances of the N delta H protons of the alpha and beta subunits of bovine deoxyhemoglobin do not interfere with the measurement of myoglobin deoxygenation in blood-perfused rat heart. We find that steady-state myoglobin deoxygenation is increased progressively (and reversibly) as oxygenation of the perfusing medium is decreased in both saline and red blood cell-perfused hearts at constant work output. An eightfold increase in the heart rate of the blood-perfused heart resulted in no change in the deoxymyoglobin signal intensity. Intracellular PO2 of myoglobin-containing cells is maintained remarkably constant in changing work states. PMID:7612857

  14. Preoperative mucosal tolerance to brain antigens and a neuroprotective immune response following surgical brain injury

    PubMed Central

    Ayer, Robert E.; Jafarian, Nazanin; Chen, Wanqiu; Applegate, Richard L.; Colohan, Austin R. T.; Zhang, John H.

    2015-01-01

    Object Intracranial surgery causes cortical injury from incisions, hemorrhage, retraction, and electrocautery. The term “surgical brain injury” (SBI) has been developed to categorize this injury inherent to the procedure. Neuroinflammation plays a significant role in SBI. Traditional antiinflammatory therapies are often limited by their immunosuppressive side effects and poor CNS penetration. This study uses mucosal tolerance to develop an immune system that is tolerant to brain myelin basic protein (MBP) so that inflammation can be suppressed in a timely and site-specific manner following surgical disruption of the blood-brain barrier. Methods A standard SBI model using CD57 mice was used. Nasopharyngeal mucosa was exposed to vehicle, ovalbumin, or MBP to develop mucosal tolerance to these antigens. Immunological tolerance to MBP was confirmed in vivo through hypersensitivity testing. Neurological scores, cerebral edema, and interleukin (IL)–1β and transforming growth factor (TGF)–β1 cytokine levels were measured 48 hours postoperatively. Results Hypersensitivity testing confirmed the development of immune tolerance to MBP. Myelin basic protein– tolerant mice demonstrated reduced neurological injury, less cerebral edema, decreased levels of IL-1β, and increased levels of TGFβ1 following SBI. Conclusions Developing preoperative immunological tolerance to brain antigens through mucosal tolerance provides neuroprotection, reduces brain edema, and modulates neuroinflammation following SBI. PMID:22017304

  15. Perfusion education and training in Europe.

    PubMed

    Merkle, Frank

    2006-01-01

    Perfusion education and training varies considerably throughout Europe. Unlike in the US, where a common curriculum for perfusion education has been established, each European country has its own education system. This fact is further complicated by a multitude of national languages and cultures. Thus, perfusion education programmes vary, not only in content, but also in their academic levels. This article aims to give a comprehensive overview of the situation in each of the 20 member states of the European Board of Cardiovascular Perfusion (EBCP). The EBCP delegates were polled for a description of the process of training and education of clinical perfusionists in their respective countries. Following the initial delegate poll in 2001, an update of the material was performed in spring 2005. In summary, training of clinical perfusionists in Europe varies considerably between countries. A professional body is necessary to oversee the training process and to guarantee a minimum level of clinical competency for cardiovascular perfusionists. PMID:16485693

  16. Perioperative Blood Pressure Control and Management.

    PubMed

    Duke-Novakovski, Tanya; Carr, Anthony

    2015-09-01

    Blood pressure monitoring and management is a vital part of the perianesthetic period. Disturbances in blood pressure, especially hypotension, can have significant impacts on the well-being of small animal patients. There are a variety of mechanisms present to control blood pressure, including ultra-short-, short-, and long-term mechanisms. Several conditions can contribute to decreased blood pressure, including anesthetics, tension pneumothorax, intermittent positive pressure ventilation, hypoxemia, hypercapnia, surgical positioning, and abdominal distension. If hypotension is encountered, the initial response is to provide appropriate fluid therapy. If this is inadequate, other interventions can be used to increase blood pressure and thereby increase perfusion. PMID:26076581

  17. Cytokine Production and Antigen Recognition by Human Mucosal Homing Conjunctival Effector Memory CD8+ T Cells

    PubMed Central

    Williams, Geraint P.; Pachnio, Annette; Long, Heather M.; Rauz, Saaeha; Curnow, S. John

    2014-01-01

    Purpose. Conjunctival epithelial T cells are dominated by CD3+CD56-TCRαβ+CD8αβ+ lymphocytes. In this study we explored the antigen experience status, mucosal homing phenotype, cytokine expression, and viral antigen recognition of conjunctival epithelial CD8+ T cells from healthy individuals. Methods. Following ocular surface impression cytology, conjunctival cells were recovered by gentle agitation and analyzed by flow cytometry for cell surface markers, cytokine production (stimulated by phorbol 12-myristate 13-acetate [PMA]/ionomycin), and Epstein-Barr virus (EBV)/cytomegalovirus (CMV) immunodominant epitope recognition using major histocompatibility complex (MHC) class I peptide tetramers. Results. In contrast to peripheral blood, conjunctival epithelial CD8+ T cells were dominantly CD45RA−CCR7− effector memory cells, and the vast majority expressed the mucosal homing integrin αEβ7. Conjunctival memory CD8+ T cells maintained effector functions with the ability to secrete IFN-γ and expression of Granzyme B, although they expressed significantly reduced amounts per cell compared to peripheral blood T cells. Interestingly, herpetic virus-specific CD8+ T cells recognizing epitopes derived from EBV and CMV could be detected in the conjunctival cells of healthy virus carriers, although they were generally at lower frequencies than in the peripheral blood of the same donor. Virus-specific conjunctival CD8+ T cells were dominated by CD45RA−CCR7− effector memory cells that expressed αEβ7. Conclusions. These data demonstrate that the majority of conjunctival epithelial CD8+ T cells are mucosal homing αEβ7+ effector memory T cells, which can recognize viral epitopes and are capable of secreting Granzyme B and IFN-γ. PMID:25395484

  18. Evidence for Early Local Viral Replication and Local Production of Antiviral Immunity upon Mucosal Simian-Human Immunodeficiency Virus SHIV89.6 Infection in Macaca nemestrina

    PubMed Central

    Ambrose, Zandrea; Larsen, Kay; Thompson, Jannelle; Stevens, Yvonne; Finn, Eric; Hu, Shiu-Lok; Bosch, Marnix L.

    2001-01-01

    Transmission of human immunodeficiency virus type 1 (HIV-1) is largely a result of heterosexual exposure, leading many investigators to evaluate mucosal vaccines for protection against intravaginal (i.vag.) transmission in macaque models of AIDS. Relatively little is known, however, about the dynamics of viral replication and the ensuing immune response following mucosal infection. We have utilized a simian-human immunodeficiency virus (SHIV) to study the differences in viremia, CD4 T-cell percentages, and mucosal and systemic anti-SHIV humoral and cellular immune responses during primary infection of animals infected either intravenously (i.v.) or i.vag. Positive viral cocultures, peripheral blood mononuclear cell viral load peaks, and CD4 cell declines were delayed by 1 week in the i.vag. inoculated animals compared to the animals infected i.v., demonstrating delayed viral spreading to the periphery. In contrast, mucosal anti-SHIV antibody levels were greater in magnitude and arose more rapidly and mucosal CD8+ T-cell responses were enhanced in the i.vag. group animals, whereas both the magnitudes and times of onset of systemic immune responses for the animals in the two groups did not differ. These observations demonstrate that compartmentalization of viral replication and induction of local antiviral immunity occur in the genital tract early after i.vag. but not i.v. inoculation. Induction of mucosal immunity to target this local, contained replication should be a goal in HIV vaccine development. PMID:11507204

  19. Gut dendritic cell activation links an altered colonic microbiome to mucosal and systemic T-cell activation in untreated HIV-1 infection.

    PubMed

    Dillon, S M; Lee, E J; Kotter, C V; Austin, G L; Gianella, S; Siewe, B; Smith, D M; Landay, A L; McManus, M C; Robertson, C E; Frank, D N; McCarter, M D; Wilson, C C

    2016-01-01

    HIV-1-associated disruption of intestinal homeostasis is a major factor contributing to chronic immune activation and inflammation. Dendritic cells (DCs) are crucial in maintaining intestinal homeostasis, but the impact of HIV-1 infection on intestinal DC number and function has not been extensively studied. We compared the frequency and activation/maturation status of colonic myeloid DC (mDC) subsets (CD1c(+) and CD1c(neg)) and plasmacytoid DCs in untreated HIV-1-infected subjects with uninfected controls. Colonic mDCs in HIV-1-infected subjects had increased CD40 but decreased CD83 expression, and CD40 expression on CD1c(+) mDCs positively correlated with mucosal HIV-1 viral load, with mucosal and systemic cytokine production, and with frequencies of activated colon and blood T cells. Percentage of CD83(+)CD1c(+) mDCs negatively correlated with frequencies of interferon-γ-producing colon CD4(+) and CD8(+) T cells. CD40 expression on CD1c(+) mDCs positively associated with abundance of high prevalence mucosal Prevotella copri and Prevotella stercorea but negatively associated with a number of low prevalence mucosal species, including Rumminococcus bromii. CD1c(+) mDC cytokine production was greater in response to in vitro stimulation with Prevotella species relative to R. bromii. These findings suggest that, during HIV infection, colonic mDCs become activated upon exposure to mucosal pathobiont bacteria leading to mucosal and systemic immune activation. PMID:25921339

  20. Gut Dendritic Cell Activation Links an Altered Colonic Microbiome to Mucosal and Systemic T Cell Activation in Untreated HIV-1 infection

    PubMed Central

    Dillon, SM; Lee, EJ; Kotter, CV; Austin, GL; Gianella, S; Siewe, B; Smith, DM; Landay, AL; McManus, MC; Robertson, CE; Frank, DN; McCarter, MD; Wilson, CC

    2015-01-01

    HIV-1-associated disruption of intestinal homeostasis is a major factor contributing to chronic immune activation and inflammation. Dendritic cells (DCs) are crucial in maintaining intestinal homeostasis, but the impact of HIV-1 infection on intestinal DC number and function has not been extensively studied. We compared the frequency and activation/maturation status of colonic myeloid DC (mDC) subsets (CD1c+ and CD1cneg) and plasmacytoid DCs in untreated HIV-1-infected subjects with uninfected controls. Colonic mDCs in HIV-1-infected subjects had increased CD40 but decreased CD83 expression, and CD40 expression on CD1c+ mDCs positively correlated with mucosal HIV-1 viral load, with mucosal and systemic cytokine production, and with frequencies of activated colon and blood T cells. Percent of CD83+CD1c+ mDCs negatively correlated with frequencies of IFN-γ-producing colon CD4+ and CD8+ T cells. CD40 expression on CD1c+ mDCs positively associated with abundance of high prevalence mucosal Prevotella copri and P. stercorea, but negatively associated with a number of low prevalence mucosal species including Rumminococcus bromii. CD1c+ mDC cytokine production was greater in response to in vitro stimulation with Prevotella species relative to R. bromii. These findings suggest that during HIV infection, colonic mDCs become activated upon exposure to mucosal pathobiont bacteria leading to mucosal and systemic immune activation. PMID:25921339

  1. OCT visualization of acute radiation mucositis: pilot study

    NASA Astrophysics Data System (ADS)

    Gladkova, Natalia; Maslennikova, Anna; Terentieva, Anna; Fomina, Yulia; Khomutinnikova, Nina; Balalaeva, Irina; Vyseltseva, Yulia; Larin, Roman; Kornoukhova, Natalia; Shakhov, Andrey; Shakhova, Natalia; Gelikonov, Grigory; Kamensky, Vladislav; Feldchtein, Felix

    2005-08-01

    We present pilot results in optical coherence tomography (OCT) visualization of normal mucosa radiation damage. 15 patients undergoing radiation treatment of head and neck cancer were enrolled. OCT was used to monitor the mucositis development during and after treatment. OCT can see stages of radiation mucositis development, including hidden ones, before any clinical manifestations.

  2. Induction of mucosal immunity through systemic immunization: Phantom or reality?

    PubMed

    Su, Fei; Patel, Girishchandra B; Hu, Songhua; Chen, Wangxue

    2016-04-01

    Generation of protective immunity at mucosal surfaces can greatly assist the host defense against pathogens which either cause disease at the mucosal epithelial barriers or enter the host through these surfaces. Although mucosal routes of immunization, such as intranasal and oral, are being intensely explored and appear promising for eliciting protective mucosal immunity in mammals, their application in clinical practice has been limited due to technical and safety related challenges. Most of the currently approved human vaccines are administered via systemic (such as intramuscular and subcutaneous) routes. Whereas these routes are acknowledged as being capable to elicit antigen-specific systemic humoral and cell-mediated immune responses, they are generally perceived as incapable of generating IgA responses or protective mucosal immunity. Nevertheless, currently licensed systemic vaccines do provide effective protection against mucosal pathogens such as influenza viruses and Streptococcus pneumoniae. However, whether systemic immunization induces protective mucosal immunity remains a controversial topic. Here we reviewed the current literature and discussed the potential of systemic routes of immunization for the induction of mucosal immunity. PMID:26752023

  3. Effects of mucosal loading on vocal fold vibration

    NASA Astrophysics Data System (ADS)

    Tao, Chao; Jiang, Jack J.

    2009-06-01

    A chain model was proposed in this study to examine the effects of mucosal loading on vocal fold vibration. Mucosal loading was defined as the loading caused by the interaction between the vocal folds and the surrounding tissue. In the proposed model, the vocal folds and the surrounding tissue were represented by a series of oscillators connected by a coupling spring. The lumped masses, springs, and dampers of the oscillators modeled the tissue properties of mass, stiffness, and viscosity, respectively. The coupling spring exemplified the tissue interactions. By numerically solving this chain model, the effects of mucosal loading on the phonation threshold pressure, phonation instability pressure, and energy distribution in a voice production system were studied. It was found that when mucosal loading is small, phonation threshold pressure increases with the damping constant Rr, the mass constant Rm, and the coupling constant Rμ of mucosal loading but decreases with the stiffness constant Rk. Phonation instability pressure is also related to mucosal loading. It was found that phonation instability pressure increases with the coupling constant Rμ but decreases with the stiffness constant Rk of mucosal loading. Therefore, it was concluded that mucosal loading directly affects voice production.

  4. Acute appendicitis following endoscopic mucosal resection of cecal adenoma.

    PubMed

    Nemoto, Yukako; Tokuhisa, Junya; Shimada, Nagasato; Gomi, Tatsuya; Maetani, Iruru

    2015-07-21

    Endoscopic mucosal resection (EMR) allows the removal of flat or sessile lesions, laterally spreading tumors, and carcinoma of the colon or the rectum limited to the mucosa or the superficial submucosa. Acute appendicitis is the most common abdominal emergency requiring emergency surgery, and it is also a rare complication of diagnostic colonoscopy and therapeutic endoscopy, including EMR. In the case presented here, a 53-year-old female underwent colonoscopy due to a positive fecal occult blood test and was diagnosed with cecal adenoma. She was referred to our hospital and admitted for treatment. The patient had no other symptoms. EMR was performed, and 7 h after the surgery, the patient experienced right -lower abdominal pain. Laboratory tests performed the following day revealed a WBC count of 16000/mm(3), a neutrophil count of 14144/mm(3), and a C-reactive protein level of 2.20 mg/dL, indicating an inflammatory response. Computed tomography also revealed appendiceal wall thickening and swelling, so acute appendicitis following EMR was diagnosed. Antibiotics were initiated leading to total resolution of the symptoms, and the patient was discharged on the sixth post-operative day. Pathological analysis revealed a high-grade cecal tubular adenoma. Such acute appendicitis following EMR is extremely rare, and EMR of the cecum may be a rare cause of acute appendicitis. PMID:26217100

  5. Endoscopic mucosal resection of early stage colon neuroendocrine carcinoma.

    PubMed

    Yamasaki, Yasushi; Uedo, Noriya; Ishihara, Ryu; Tomita, Yasuhiko

    2015-01-01

    Early stage colorectal neuroendocrine carcinoma is rare. A small colon tumour was found in a 56-year-old man during diagnostic colonoscopy performed after a positive faecal occult blood test, and he was referred for treatment. A slightly reddish superficial elevated lesion with a shallow depression 10 mm in size was found in the transverse colon. Magnifying narrow-band imaging revealed disrupted irregular microvessels and the absence of a surface pattern in the depressed area. En bloc endoscopic mucosal resection (EMR) of the tumour was undertaken. The tumour was positive for chromogranin A and synaptophysin, and had a mitotic rate of >20/10 high-power fields and a Ki-67 proliferative index of >50%; it was diagnosed as a neuroendocrine carcinoma. The tumour minimally invaded the submucosa (300 μm) without lymphovascular involvement. The patient was followed up carefully, and at 1 year after EMR, no recurrence was found using colonoscopy and CT scans. PMID:25737221

  6. Acute appendicitis following endoscopic mucosal resection of cecal adenoma

    PubMed Central

    Nemoto, Yukako; Tokuhisa, Junya; Shimada, Nagasato; Gomi, Tatsuya; Maetani, Iruru

    2015-01-01

    Endoscopic mucosal resection (EMR) allows the removal of flat or sessile lesions, laterally spreading tumors, and carcinoma of the colon or the rectum limited to the mucosa or the superficial submucosa. Acute appendicitis is the most common abdominal emergency requiring emergency surgery, and it is also a rare complication of diagnostic colonoscopy and therapeutic endoscopy, including EMR. In the case presented here, a 53-year-old female underwent colonoscopy due to a positive fecal occult blood test and was diagnosed with cecal adenoma. She was referred to our hospital and admitted for treatment. The patient had no other symptoms. EMR was performed, and 7 h after the surgery, the patient experienced right -lower abdominal pain. Laboratory tests performed the following day revealed a WBC count of 16000/mm3, a neutrophil count of 14144/mm3, and a C-reactive protein level of 2.20 mg/dL, indicating an inflammatory response. Computed tomography also revealed appendiceal wall thickening and swelling, so acute appendicitis following EMR was diagnosed. Antibiotics were initiated leading to total resolution of the symptoms, and the patient was discharged on the sixth post-operative day. Pathological analysis revealed a high-grade cecal tubular adenoma. Such acute appendicitis following EMR is extremely rare, and EMR of the cecum may be a rare cause of acute appendicitis. PMID:26217100

  7. Myocardial perfusion imaging with 201Tl.

    PubMed

    Pagnanelli, Robert A; Basso, Danny A

    2010-03-01

    The object of this review is to provide information about (201)Tl-thallous chloride in radionuclide myocardial perfusion imaging. This technique has experienced a recent resurgence because of the shortage of (99m)Tc. After reading this article, the technologist will be able to describe the properties and uptake mechanism of (201)Tl, the procedure for myocardial perfusion imaging with this agent, and the advantages and disadvantages of thallium, compared with the technetium agents. PMID:20159930

  8. Improved exercise myocardial perfusion during lidoflazine therapy

    SciTech Connect

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

    1983-11-01

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

  9. Mucosal Correlates of Protection in HIV-1-Exposed Seronegative Persons

    PubMed Central

    Shen, Ruizhong; Smith, Phillip D.

    2014-01-01

    Resistance to HIV-1 infection in HIV-1-exposed seronegative (HESN) persons offers a promising opportunity to identify mechanisms of “natural” protection. Unique features of the mucosa in particular may contribute to this protection. Here we highlight several key issues pertaining to the mucosal correlates of protection in HESN persons, including humoral immune responses, mechanisms of mucosal HIV-1-neutralization, immune cell activation, and role of the microbiota in mucosal responses. We also discuss mucosal model systems that can be used to investigate the mechanisms of resistance in HESN subjects. A clear understanding of the mucosal correlates of protection against HIV-1 in HESN persons will provide critical new insights for the development of effective vaccine and microbicide strategies for the prevention of HIV-1 transmission. PMID:24428610

  10. Dynamic chest radiography with a flat-panel detector (FPD): ventilation-perfusion study

    NASA Astrophysics Data System (ADS)

    Tanaka, R.; Sanada, S.; Fujimura, M.; Yasui, M.; Tsuji, S.; Hayashi, N.; Okamoto, H.; Nanbu, Y.; Matsui, O.

    2011-03-01

    Pulmonary ventilation and blood flow are reflected in dynamic chest radiographs as changes in X-ray translucency, i.e., pixel values. This study was performed to investigate the feasibility of ventilation-perfusion (V/Q) study based on the changes in pixel value. Sequential chest radiographs of a patient with ventilation-perfusion mismatch were obtained during respiration using a dynamic flat-panel detector (FPD) system. The lung area was recognized and average pixel value was measured in each area, tracking and deforming the region of interest. Inter-frame differences were then calculated, and the absolute values were summed in each respiratory phase. The results were visualized as ventilation, blood flow, V/Q ratio distribution map and compared to distribution of radioactive counts on ventilation and perfusion scintigrams. In the results, abnormalities were appeared as a reduction of changes in pixel values, and a correlation was observed between the distribution of changes in pixel value and those of radioactivity counts (Ventilation; r=0.78, Perfusion; r=0.77). V/Q mismatch was also indicated as mismatch of changes in pixel value, and a correlation with V/Q calculated by radioactivity counts (r=0.78). These results indicated that the present method is potentially useful for V/Q study as an additional examination in conventional chest radiography.

  11. Measurement of both left ventricular function and regional myocardial perfusion with 133Xe in dogs.

    PubMed

    Ruddy, T D; Yasuda, T; Barlai-Kovach, M; Nedelman, M A; Moore, R H; Alpert, N M; Correia, J A; Newell, J B; Okada, R D; Boucher, C A

    1987-01-01

    A technique to measure left ventricular (LV) function and myocardial perfusion was validated in 12 dogs. 133Xe in saline was injected into the left atrium (LA) or LV and two data sets were obtained using gamma camera imaging: 1) A first pass gated scan for LV function; followed by 2) Sequential images for regional myocardial perfusion. LV ejection fraction and wall motion measurements from the 133Xe blood pool images were compared to ejection fraction (r = 0.88, P less than 0.01) and wall motion (r = 0.83, P less than 0.01) data from 99mTc labeled blood pool scans. The perfusion measurements obtained with the 133Xe method were compared to microsphere data (r = 0.79, P less than 0.01). Measurements after LV 133Xe injection were similar to data following LA injection. Thus, quantitative assessment of global LV function, regional wall motion and myocardial perfusion is possible with LA or LV 133Xe injection and gamma camera imaging. PMID:3569342

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

    PubMed Central

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

    2015-01-01

    Perfusion imaging is the most applied modality for the assessment of acute stroke. Parameters such as Cerebral Blood Flow (CBF), Cerebral Blood volume (CBV) and Mean Transit Time (MTT) are used to distinguish the tissue infarct core and ischemic penumbra. Due to lack of standardization these parameters vary significantly between vendors and software even when provided with the same data set. There is a critical need to standardize the systems and make them more reliable. We have designed a uniform phantom to test and verify the perfusion systems. We implemented a flow loop with different flow rates (250, 300, 350 ml/min) and injected the same amount of contrast. The images of the phantom were acquired using a Digital Angiographic system. Since this phantom is uniform, projection images obtained using DSA is sufficient for initial validation. To validate the phantom we measured the contrast concentration at three regions of interest (arterial input, venous output, perfused area) and derived time density curves (TDC). We then calculated the maximum slope, area under the TDCs and flow. The maximum slope calculations were linearly increasing with increase in flow rate, the area under the curve decreases with increase in flow rate. There was 25% error between the calculated flow and measured flow. The derived TDCs were clinically relevant and the calculated flow, maximum slope and areas under the curve were sensitive to the measured flow. We have created a systematic way to calibrate existing perfusion systems and assess their reliability. PMID:26633914

  13. Functional cluster analysis of CT perfusion maps: a new tool for diagnosis of acute stroke?

    PubMed

    Baumgartner, Christian; Gautsch, Kurt; Böhm, Christian; Felber, Stephan

    2005-09-01

    CT perfusion imaging constitutes an important contribution to the early diagnosis of acute stroke. Cerebral blood flow (CBF), cerebral blood volume (CBV) and time-to-peak (TTP) maps are used to estimate the severity of cerebral damage after acute ischemia. We introduce functional cluster analysis as a new tool to evaluate CT perfusion in order to identify normal brain, ischemic tissue and large vessels. CBF, CBV and TTP maps represent the basis for cluster analysis applying a partitioning (k-means) and density-based (density-based spatial clustering of applications with noise, DBSCAN) paradigm. In patients with transient ischemic attack and stroke, cluster analysis identified brain areas with distinct hemodynamic properties (gray and white matter) and segmented territorial ischemia. CBF, CBV and TTP values of each detected cluster were displayed. Our preliminary results indicate that functional cluster analysis of CT perfusion maps may become a helpful tool for the interpretation of perfusion maps and provide a rapid means for the segmentation of ischemic tissue. PMID:15827821

  14. Methodology for ventilation/perfusion SPECT.

    PubMed

    Bajc, Marika; Neilly, Brian; Miniati, Massimo; Mortensen, Jan; Jonson, Björn

    2010-11-01

    Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas over radiolabeled liquid aerosols are not restricted to the presence of obstructive lung disease. Radiolabeled macroaggregated human albumin is the imaging agent of choice for perfusion scintigraphy. An optimal combination of nuclide activities and acquisition times for ventilation and perfusion, collimators, and imaging matrix yields an adequate V/Q SPECT study in approximately 20 minutes of imaging time. The recommended protocol based on the patient remaining in an unchanged position during the initial ventilation study and the perfusion study allows presentation of matching ventilation and perfusion slices in all projections as well as in rotating volume images based upon maximum intensity projections. Probabilistic interpretation of V/Q SPECT should be replaced by a holistic interpretation strategy on the basis of all relevant information about the patient and all ventilation/perfusion patterns. PE is diagnosed when there is more than one subsegment showing a V/Q mismatch representing an anatomic lung unit. Apart from pulmonary embolism, other pathologies should be identified and reported, for example, obstructive disease, heart failure, and pneumonia. Pitfalls exist both with respect to imaging technique and scan interpretation. PMID:20920632

  15. Blood sugar test - blood

    MedlinePlus

    ... drink a certain amount of glucose ( oral glucose tolerance test ) How the Test will Feel When the ... a fasting blood glucose, HbA1c test , or glucose tolerance test , depending on your random blood glucose test ...

  16. Selected contribution: redistribution of pulmonary perfusion during weightlessness and increased gravity

    NASA Technical Reports Server (NTRS)

    Glenny, R. W.; Lamm, W. J.; Bernard, S. L.; An, D.; Chornuk, M.; Pool, S. L.; Wagner, W. W. Jr; Hlastala, M. P.; Robertson, H. T.

    2000-01-01

    To compare the relative contributions of gravity and vascular structure to the distribution of pulmonary blood flow, we flew with pigs on the National Aeronautics and Space Administration KC-135 aircraft. A series of parabolas created alternating weightlessness and 1.8-G conditions. Fluorescent microspheres of varying colors were injected into the pulmonary circulation to mark regional blood flow during different postural and gravitational conditions. The lungs were subsequently removed, air dried, and sectioned into approximately 2 cm(3) pieces. Flow to each piece was determined for the different conditions. Perfusion heterogeneity did not change significantly during weightlessness compared with normal and increased gravitational forces. Regional blood flow to each lung piece changed little despite alterations in posture and gravitational forces. With the use of multiple stepwise linear regression, the contributions of gravity and vascular structure to regional perfusion were separated. We conclude that both gravity and the geometry of the pulmonary vascular tree influence regional pulmonary blood flow. However, the structure of the vascular tree is the primary determinant of regional perfusion in these animals.

  17. Protective effect of histamine microinjected into cerebellar fastigial nucleus on stress gastric mucosal damage in rats.

    PubMed

    Qiao, Xiao; Yang, Jun; Fei, Su-Juan; Zhu, Jin-Zhou; Zhu, Sheng-Ping; Liu, Zhang-Bo; Li, Ting-Ting; Zhang, Jian-Fu

    2015-12-10

    In the study, we investigated the effect of histamine microinjected into cerebellar fastigial nucleus (FN) on stress gastric mucosal damage (SGMD), and its mechanisms in rats. The model of SGMD was established by restraining and water (21±1°C)-immersion for 3h. The gastric mucosal damage index (GMDI) indicated the severity of gastric mucosal damage. Histamine or receptor antagonist was microinjected into the FN. The decussation of superior cerebellar peduncle (DSCP) and the lateral hypothalamic area (LHA) were destroyed, respectively. The pathological changes of gastric mucosa were evaluated using biological signal acquisition system, Laser-Doppler flowmeter, and western blotting. We found that the microinjection of histamine (0.05, 0.5, and 5μg) into FN significantly attenuated the SGMD, in a dose-dependent manner, whereas, the microinjection of histamine H2 receptor antagonist, ranitidine, and glutamic acid decarboxylase antagonist, 3-mercaptopropionic acid (3-MPA) exacerbated the SGMD. The protective effect of histamine on SGMD was abolished by electrical lesion of DSCP or chemical ablation of LHA. The microinjection of histamine decreased the discharge frequency of the greater splanchnic nerve, and the gastric mucosal blood flow was increased. In addition, the cellular proliferation was enhanced, but the cellular apoptosis was reduced in the gastric mucosa. Also the pro-apoptosis protein, Bax, and caspase-3 were down-regulated, and the anti-apoptosis protein, Bcl-2 was up-regulated following microinjection of histamine. In conclusion, the FN participated in the regulation of SGMD after histamine microinjected into FN, and cerebellar-hypothalamic circuits (include: DSCP, LHA) contribute to the process, which may provide a new therapeutic strategy for SGMD. PMID:26474912

  18. Patterns of postictal cerebral perfusion in idiopathic generalized epilepsy: a multi-delay multi-parametric arterial spin labelling perfusion MRI study

    PubMed Central

    Chen, Guangxiang; Lei, Du; Ren, Jiechuan; Zuo, Panli; Suo, Xueling; Wang, Danny J. J.; Wang, Meiyun; Zhou, Dong; Gong, Qiyong

    2016-01-01

    The cerebral haemodynamic status of idiopathic generalized epilepsy (IGE) is a very complicated process. Little attention has been paid to cerebral blood flow (CBF) alterations in IGE detected by arterial spin labelling (ASL) perfusion magnetic resonance imaging (MRI). However, the selection of an optimal delay time is difficult for single-delay ASL. Multi-delay multi-parametric ASL perfusion MRI overcomes the limitations of single-delay ASL. We applied multi-delay multi-parametric ASL perfusion MRI to investigate the patterns of postictal cerebral perfusion in IGE patients with absence seizures. A total of 21 IGE patients with absence seizures and 24 healthy control subjects were enrolled. IGE patients exhibited prolonged arterial transit time (ATT) in the left superior temporal gyrus. The mean CBF of IGE patients was significantly increased in the left middle temporal gyrus, left parahippocampal gyrus and left fusiform gyrus. Prolonged ATT in the left superior temporal gyrus was negatively correlated with the age at onset in IGE patients. This study demonstrated that cortical dysfunction in the temporal lobe and fusiform gyrus may be related to epileptic activity in IGE patients with absence seizures. This information can play an important role in elucidating the pathophysiological mechanism of IGE from a cerebral haemodynamic perspective. PMID:27374369

  19. Hypothermic machine perfusion of the liver and the critical balance between perfusion pressures and endothelial injury.

    PubMed

    't Hart, N A; van der Plaats, A; Leuvenink, H G D; van Goor, H; Wiersema-Buist, J; Verkerke, G J; Rakhorst, G; Ploeg, R J

    2005-01-01

    Hypothermic machine perfusion (HMP) provides better protection against cold ischemic injury than cold storage in marginal donor kidneys. Also, in liver transplantation a switch from static cold storage to HMP could be beneficial as it would allow longer preservation times and the use of marginal donors. A critical question concerning application of HMP in liver preservation is the crucial balance between perfusion pressure and occurrence of endothelial injury. Rat livers were cold-perfused for 24 hours to study perfusion pressures for both hepatic artery and portal vein. Cold storage served as control and was compared to HMP-preserved livers using a mean arterial perfusion pressure of 25 mm Hg and a portal perfusion pressure of 4 mm Hg (25% of normothermic liver circulation) and to HMP at 50 mm Hg and 8 mm Hg perfusion, respectively (50% of normothermic liver circulation). UW solution was enriched with 14.9 micromol/L propidium iodide (PI) to stain for dead cells and with an additional 13.5 micromol/L acridine orange to stain for viable hepatocytes. A low PI-positive cell count was found using HMP at 25% of normal circulation compared to cold storage. The PI count was high for the HMP group perfused at just 50% of normal circulation compared to HMP at 25% and compared to cold storage. In summary, for liver HMP, perfusion at 25% showed complete perfusion with minimal cellular injury. HMP using perfusion pressures of 25 mm Hg for the hepatic artery and 4 mm Hg for the portal vein is feasible without induction of endothelial injury. PMID:15808634

  20. Venovenous perfusion in ECMO for newborn respiratory insufficiency. A clinical comparison with venoarterial perfusion.

    PubMed Central

    Klein, M D; Andrews, A F; Wesley, J R; Toomasian, J; Nixon, C; Roloff, D; Bartlett, R H

    1985-01-01

    Venoarterial (VA) extracorporeal membrane oxygenation (ECMO) has been successful in the treatment of newborns less than 1 week of age and greater than 2000 gm birthweight with respiratory failure resistant to current medical and surgical management. While VA ECMO supports the heart as well as the lungs, it has the disadvantage of requiring carotid artery ligation and the possibility of perfusing air bubbles or particles into the arterial tree. We have treated 11 newborns with respiratory failure with venovenous (VV) ECMO returning the oxygenated blood to a cannula in the distal iliac vein. We compared these patients with 16 patients treated during the same period of time with VA ECMO. Three of the 11 VV patients required conversion to VA ECMO because of inadequate oxygenation and unstable hemodynamic situations. Ten of the 11 VV patients survived. Eleven of the 16 VA patients survived. The better survival in these patients treated with VV ECMO is attributed to their more favorable initial condition compared to patients treated with VA ECMO. The disadvantages of VV ECMO include a longer operative time to place the cannulas, groin wound problems, and persistent leg swelling along with the necessity to convert some patients to VA ECMO. Although this experience demonstrates that newborns with severe respiratory failure can be supported with VV ECMO, the complications and lack of practical advantages over VA lead us to recommend VA ECMO for routine clinical use at present. PMID:3977454

  1. Autologous Transplantation of Oral Mucosal Epithelial Cell Sheets Cultured on an Amniotic Membrane Substrate for Intraoral Mucosal Defects

    PubMed Central

    Amemiya, Takeshi; Nakamura, Takahiro; Yamamoto, Toshiro; Kinoshita, Shigeru; Kanamura, Narisato

    2015-01-01

    The human amniotic membrane (AM) is a thin intrauterine placental membrane that is highly biocompatible and possesses anti-inflammatory and anti-scarring properties. Using AM, we developed a novel method for cultivating oral mucosal epithelial cell sheets. We investigated the autologous transplantation of oral mucosal epithelial cells cultured on AM in patients undergoing oral surgeries. We obtained specimens of AM from women undergoing cesarean sections. This study included five patients without any history of a medical disorder who underwent autologous cultured oral epithelial transplantation following oral surgical procedures. Using oral mucosal biopsy specimens obtained from these patients, we cultured oral epithelial cells on an AM carrier. We transplanted the resultant cell sheets onto the oral mucosal defects. Patients were followed-up for at least 12 months after transplantation. After 2–3 weeks of being cultured on AM, epithelial cells were well differentiated and had stratified into five to seven layers. Immunohistochemistry revealed that the cultured cells expressed highly specific mucosal epithelial cell markers and basement membrane proteins. After the surgical procedures, no infection, bleeding, rejection, or sheet detachment occurred at the reconstructed sites, at which new oral mucous membranes were evident. No recurrence was observed in the long-term follow-up, and the postoperative course was excellent. Our results suggest that AM-cultured oral mucosal epithelial cell sheets represent a useful biomaterial and feasible method for oral mucosal reconstruction. However, our primary clinical study only evaluated their effects on a limited number of small oral mucosal defects. PMID:25915046

  2. Endothelium-dependent relaxation of blood vessels

    SciTech Connect

    Hynes, M.R.

    1987-01-01

    Dilation of blood vessels in response to a large number of agents has been shown to be dependent on an intact vascular endothelium. The present studies examine some aspects of endothelium-dependent vasodilation in blood vessels of the rabbit and rat. Using the rabbit ear artery and the subtype-selective muscarinic antagonist pirenzepine, muscarinic receptors of the endothelium and smooth muscle cells were shown to be of the low affinity M/sub 2/ subtype. Inhibition of (/sup 3/H)(-)quinuclidinyl benzilate was used to determine affinity for the smooth muscle receptors while antagonism of methacholine induced vasodilation yielded the endothelial cell receptor affinity. The effect of increasing age (1-27 months) on endothelium-dependent relaxation was studied in aortic rings, perfused tail artery and perfused mesenteric bed of the Fisher 344 rat. The influence of endothelium on contractile responses was examined using the perfused caudal artery.

  3. The release and vascular action of bradykinin in the isolated perfused bovine udder

    PubMed Central

    Zeitlin, I J; Eshraghi, H R

    2002-01-01

    It has been postulated that the mammary kinin system may play a role in modulating mammary blood flow. Until the present study, the local release of bradykinin (BK) or other kinin system constituents into the mammary vasculature had not been reported and there were also conflicting findings on the action of BK on udder vasculature. Udders were removed from healthy lactating cows at slaughter. Pairs of ipsilateral quarters were perfused with Tyrode solution through the external pudendalis artery and drained via the cranial superficial epigastric vein. Mammary secretion was collected through teat cannulae. The perfusion pressure was linearly related to perfusate flux between 60 and 210 ml min−1 and the flow rate was adjusted (110-150 ml min−1) to give a basal pressure of 85 mmHg. PO2, PCO2 and pH in the venous effluent perfusate stabilised at 157 ± 10 mmHg, 50.1 ± 2.4 mmHg and 7.1 ± 0.03, respectively. The venous effluent contained immunoreactive BK and BK precursor, tissue kallikrein activity, and bradykinin-destroying enzyme. The concentration of BK stabilised at 378 ± 48 pg (ml perfusate)−1, that of trypsin-activated BK precursor was 679 ± 59 pg BK equivalents ml−1 and that of tissue kallikrein, measured as cleavage of d-Val.Leu.Arg-p-nitroanilide (d-Val.Leu.Arg-pNA), was 5.5 ± 1.7 nmol p-NA h−1 ml−1. Arterial infusion of phenylephrine (0.49-490 μM) produced increases in perfusion pressure (vasoconstriction). Acetylcholine (ACh) (0.55-55 μM) and BK (0.1-10 μM) produced only vasodilatation. BK (EC50 = 1.00±0.04 μM) was a more potent vasodilator than ACh (EC50 = 9.57±0.49 μM). The basal BK concentration was 250 times below the threshold for vasoactivity. The udder produced a milk-like secretion, which was dependent on perfusate flow and contained a concentration of BK which remained unchanged from 60 to 180 min of perfusion (231 ± 31 pg ml−1) unlike that in the venous effluent which doubled between 60 and 120 min. Thus, in addition to its

  4. Cyclosporin metabolism by human gastrointestinal mucosal microsomes.

    PubMed Central

    Webber, I R; Peters, W H; Back, D J

    1992-01-01

    The in vitro metabolism of the immunosuppressant cyclosporin (CsA) by human gastrointestinal mucosal microsomes has been studied. Macroscopically normal intestinal (n = 4) and liver (n = 2) tissue was obtained from kidney transplant donors, and microsomes prepared. Intestinal metabolism was most extensive with duodenal protein (15% conversion to metabolites M1/M17 after 2 h incubation at 37 degrees C; metabolite measurement by h.p.l.c). Western blotting confirmed the presence of P-4503A (enzyme subfamily responsible for CsA metabolism) in duodenum and ileum tissue, but not in colon tissue. The results of this study indicate that the gut wall may play a role in the first-pass metabolism of CsA, and could therefore be a contributory factor to the highly variable oral bioavailability of CsA. PMID:1389941

  5. Head and neck mucosal melanoma: a review.

    PubMed

    Lourenço, Silvia V; Fernandes, Juliana D; Hsieh, Ricardo; Coutinho-Camillo, Claudia M; Bologna, Sheyla; Sangueza, Martin; Nico, Marcello M S

    2014-07-01

    Head and neck mucosal melanoma (MM) is an aggressive and rare neoplasm of melanocytic origin. To date, few retrospective series and case reports have been reported on MM. This article reviews the current evidence on head and neck MM and the molecular pathways that mediate the pathogenesis of this disease. Head and neck MM accounts for 0.7%-3.8% of all melanomas and involve (in decreasing order of frequency) the sinonasal cavity, oral cavity, pharynx, larynx, and upper esophagus. Although many studies have examined MM of the head and neck and the underlying molecular pathways, individual genetic and molecular alterations were less investigated. Further studies are needed to complement existing data and to increase our understanding of melanocytes tumorigenesis. PMID:24423929

  6. Effects of Steroid Hormones on Sex Differences in Cerebral Perfusion

    PubMed Central

    Ghisleni, Carmen; Bollmann, Steffen; Biason-Lauber, Anna; Poil, Simon-Shlomo; Brandeis, Daniel; Martin, Ernst; Michels, Lars; Hersberger, Martin; Suckling, John

    2015-01-01

    Sex differences in the brain appear to play an important role in the prevalence and progression of various neuropsychiatric disorders, but to date little is known about the cerebral mechanisms underlying these differences. One widely reported finding is that women demonstrate higher cerebral perfusion than men, but the underlying cause of this difference in perfusion is not known. This study investigated the putative role of steroid hormones such as oestradiol, testosterone, and dehydroepiandrosterone sulphate (DHEAS) as underlying factors influencing cerebral perfusion. We acquired arterial spin labelling perfusion images of 36 healthy adult subjects (16 men, 20 women). Analyses on average whole brain perfusion levels included a multiple regression analysis to test for the relative impact of each hormone on the global perfusion. Additionally, voxel-based analyses were performed to investigate the sex difference in regional perfusion as well as the correlations between local perfusion and serum oestradiol, testosterone, and DHEAS concentrations. Our results replicated the known sex difference in perfusion, with women showing significantly higher global and regional perfusion. For the global perfusion, DHEAS was the only significant predictor amongst the steroid hormones, showing a strong negative correlation with cerebral perfusion. The voxel-based analyses revealed modest sex-dependent correlations between local perfusion and testosterone, in addition to a strong modulatory effect of DHEAS in cortical, subcortical, and cerebellar regions. We conclude that DHEAS in particular may play an important role as an underlying factor driving the difference in cerebral perfusion between men and women. PMID:26356576

  7. Topical and mucosal liposomes for vaccine delivery.

    PubMed

    Romero, Eder Lilia; Morilla, Maria Jose

    2011-01-01

    Mucosal (and in minor extent transcutanous) stimulation can induce local or distant mucosa secretory IgA. Liposomes and other vesicles as mucosal and transcutaneous adjuvants are attractive alternatives to parenteral vaccination. Liposomes can be massively produced under good manufacturing practices and stored for long periods, at high antigen/vesicle mass ratios. However, their uptake by antigen-presenting cells (APC) at the inductive sites remains as a major challenge. As neurotoxicity is a major concern in intranasal delivery, complexes between archaeosomes and calcium as well as cationic liposomes complexed with plasmids encoding for antigenic proteins could safely elicit secretory and systemic antigen-specific immune responses. Oral bilosomes generate intense immune responses that remain to be tested against challenge, but the admixing with toxins or derivatives is mandatory to reduce the amount of antigen. Most of the current experimental designs, however, underestimate the mucus blanket 100- to 1000-fold thicker than a 100-nm diameter liposome, which has first to be penetrated to access the underlying M cells. Overall, designing mucoadhesive chemoenzymatic resistant liposomes, or selectively targeted to M cells, has produced less relevant results than tailoring the liposomes to make them mucus penetrating. Opposing, the nearly 10 µm thickness stratum corneum interposed between liposomes and underlying APC can be surpassed by ultradeformable liposomes (UDL), with lipid matrices that penetrate up to the limit with the viable epidermis. UDL made of phospholipids and detergents, proved to be better transfection agents than conventional liposomes and niosomes, without the toxicity of ethosomes, in the absence of classical immunomodulators. PMID:21360692

  8. Infection and mucosal injury in cancer treatment.

    PubMed

    Khan, S A; Wingard, J R

    2001-01-01

    The oral and gastrointestinal mucosa acts as an important mechanical barrier that prevents local or systemic invasion by microorganisms. Cytotoxic chemotherapy-induced mucosal injury (MI) of oral cavity and intestinal epithelium occurs in many patients treated for malignancy. Compromise of the mucosal barrier can contribute to local invasion by colonizing microorganisms and, subsequently, to systemic infection. Historically, gram-negative bacteremia has been the most problematic bacterial infection in neutropenic patients, but its incidence has reduced over time because of the use of prophylactic antibiotics. There has been a shift in the type of infecting organisms responsible for bacteremia in these patients, from predominantly gram-negative organisms to gram-positive cocci. The viridans group of streptococci is composed of the most frequent bacterial pathogens associated with MI. When speciated, oral colonizers such as Streptococcus mitis, Streptococcus oralis, and Streptococcus sangulis II are the most frequently identified pathogens. Other systemic infections caused by vancomycin-resistant enterococci, Stenotrophomonas maltophilia, and Candida species have also been associated with MI after cancer treatment. Infection can also exacerbate MI after cancer treatment. The best recognized example is herpes simplex virus type 1 (HSV-1). Latent virus is frequently reactivated in HSV-seropositive patients; this reactivation leads to stomatitis, which can be indistinguishable from MI caused by cytoreductive therapies. Antiviral prophylaxis or treatment can control the virus-induced MI and bring about overall amelioration of MI. Recognition of this infectious cause of MI is important in order for clinicians to anticipate and minimize oral toxicity and to facilitate optimal delivery of the antineoplastic regimen. PMID:11694563

  9. Tissue Thermal Property Reconstruction by Stopping Heating And Perfusion

    NASA Astrophysics Data System (ADS)

    Sumi, C.; Uchida, T.; Ooba, T.; Inoue, K.

    In this paper, we report robust noninvasive techniques for reconstructing the thermal properties of living tissues, such as thermal conductivity, thermal capacity and thermal diffusivity, for the diagnosis, monitoring and planning of thermal treatments such as high-intensity focus ultrasound (HIFU). Internal tissue temperature distributions can be measured using ultrasonic imaging or magnetic resonance imaging. Provided that the reference thermal properties of living tissues are given in the region of interest (ROI) as initial conditions, we can determine thermal property distributions by solving bioheat transfer equations as simultaneous first-order partial differential equations having temperature distributions as inhomogeneous coefficients. By using the reported technique, the perfusion by blood flow and thermal sources or sinks can also be reconstructed. However, in this study, we perform reconstruction after stopping heating and perfusion; only the thermal properties of living tissues can be reconstructed under such conditions. Simulations were conducted to verify the feasibility of the reconstruction. A minimally invasive thermal treatment will be realized by using our proposed reconstruction technique.

  10. In situ measurements of magnetic nanoparticles after placenta perfusion

    NASA Astrophysics Data System (ADS)

    Müller, Robert; Gläser, Marcus; Göhner, Claudia; Seyfarth, Lydia; Schleussner, Ekkehard; Hofmann, Andreas; Fritzsche, Wolfgang

    2015-04-01

    Nanoparticles (NP) present promising tools for medical applications. However, the investigation of their spatial and temporal distribution is hampered by missing in-situ particle detection and quantification technologies. The placenta perfusion experiment represents an interesting model for the study of the particle distribution at a biological barrier. It allows the ex-vivo investigation of the permeability of the placenta for materials of interest. We introduce an approach based on a magnetic system for an in situ measurement of the concentration of magnetic NPs in such an experiment. A previously off-line utilized magnetic readout device (sensitivity of ≈10-8 Am2) was used for long term measurements of magnetic NP of 100-150 nm size range in a closed circuit of a placenta perfusion. It represents a semiquantitative approach. The behavior of particles in the placenta and in the measurement system was studied, as well as the influence of particle surface modifications. The results suggest a transfer of a low amount of particles from the maternal to the fetal blood circuit.

  11. Iterative blind deconvolution in magnetic resonance brain perfusion imaging.

    PubMed

    Grüner, Renate; Taxt, Torfinn

    2006-04-01

    In first pass magnetic resonance brain perfusion imaging, arterial input functions are used in the deconvolution of the observed contrast concentrations to obtain quantitative hemodynamic parameters. Ideally, arterial input functions should be measured in each imaged voxel to eliminate the effects of delay and dispersion of the contrast agent from the injection site. An approach based on iterative blind deconvolution with the Richardson-Lucy algorithm is proposed for the simultaneous estimation of voxel-specific arterial input functions and voxel-specific tissue residue functions. An extended contrast concentration model was used to separate the first pass bolus from additional recirculation and leakage signals. The extended model was evaluated using in vivo data. Computer simulations examined the feasibility of iterative blind deconvolution in perfusion imaging. Preliminary in vivo results from a patient with fibromuscular dysplasia showed territories with delayed/dispersed arterial input functions that coincided with the location of territories supplied by collateral circulation as described from the complete radiologic examination. Higher flow values and shorter mean transit times compared to conventional methods were obtained in these areas, suggesting that the effects of dispersion were minimized. The in vivo estimated arterial input functions visualized the patient's blood supply patterns as a function of time. PMID:16526016

  12. Bayesian hemodynamic parameter estimation by bolus tracking perfusion weighted imaging.

    PubMed

    Boutelier, Timothé; Kudo, Koshuke; Pautot, Fabrice; Sasaki, Makoto

    2012-07-01

    A delay-insensitive probabilistic method for estimating hemodynamic parameters, delays, theoretical residue functions, and concentration time curves by computed tomography (CT) and magnetic resonance (MR) perfusion weighted imaging is presented. Only a mild stationarity hypothesis is made beyond the standard perfusion model. New microvascular parameters with simple hemodynamic interpretation are naturally introduced. Simulations on standard digital phantoms show that the method outperforms the oscillating singular value decomposition (oSVD) method in terms of goodness-of-fit, linearity, statistical and systematic errors on all parameters, especially at low signal-to-noise ratios (SNRs). Delay is always estimated sharply with user-supplied resolution and is purely arterial, by contrast to oSVD time-to-maximum TMAX that is very noisy and biased by mean transit time (MTT), blood volume, and SNR. Residue functions and signals estimates do not suffer overfitting anymore. One CT acute stroke case confirms simulation results and highlights the ability of the method to reliably estimate MTT when SNR is low. Delays look promising for delineating the arterial occlusion territory and collateral circulation. PMID:22410325

  13. Perfusion measures from dynamic ICG scanning laser ophthalmoscopy

    NASA Astrophysics Data System (ADS)

    Larkin, Sean; Invernizzi, Alessandro; Beecher, David; Staurenghi, Giovanni; Holmes, Tim

    2010-02-01

    Movies acquired from fundus imaging using Indocyanine Green (ICG) and a scanning laser ophthalmoscope provide information for identifying vascular and other retinal abnormalities. Today, the main limitation of this modality is that it requires esoteric training for interpretation. A straightforward interpretation of these movies by objective measurements would aid in eliminating this training barrier. A software program has been developed and tested that produces and visualizes 2D maps of perfusion measures. The program corrects for frame-to-frame misalignment caused by eye motion, including rigid misalignment and warp. The alignment method uses a cross-correlation operation that automatically detects the distance due to motion between adjacent frames. The d-ICG movie is further corrected by removing flicker and vignetting artifacts. Each pixel in the corrected movie sequence is fit with a least-squares spline to yield a smooth intensity temporal profile. From the dynamics of these intensity curves, several perfusion measures are calculated. The most effective of these measures include a metric that represents the amount of time required for a vessel to fill with dye, a metric that represents the diffusion of dye, and a metric that is affected by local blood volume. These metrics are calculated from movies acquired before and after treatment for a neovascular condition. A comparison of these before and after measures may someday provide information to the clinician that helps them to evaluate disease progression and response to treatment.

  14. GPU-accelerated voxelwise hepatic perfusion quantification.

    PubMed

    Wang, H; Cao, Y

    2012-09-01

    Voxelwise quantification of hepatic perfusion parameters from dynamic contrast enhanced (DCE) imaging greatly contributes to assessment of liver function in response to radiation therapy. However, the efficiency of the estimation of hepatic perfusion parameters voxel-by-voxel in the whole liver using a dual-input single-compartment model requires substantial improvement for routine clinical applications. In this paper, we utilize the parallel computation power of a graphics processing unit (GPU) to accelerate the computation, while maintaining the same accuracy as the conventional method. Using compute unified device architecture-GPU, the hepatic perfusion computations over multiple voxels are run across the GPU blocks concurrently but independently. At each voxel, nonlinear least-squares fitting the time series of the liver DCE data to the compartmental model is distributed to multiple threads in a block, and the computations of different time points are performed simultaneously and synchronically. An efficient fast Fourier transform in a block is also developed for the convolution computation in the model. The GPU computations of the voxel-by-voxel hepatic perfusion images are compared with ones by the CPU using the simulated DCE data and the experimental DCE MR images from patients. The computation speed is improved by 30 times using a NVIDIA Tesla C2050 GPU compared to a 2.67 GHz Intel Xeon CPU processor. To obtain liver perfusion maps with 626 400 voxels in a patient's liver, it takes 0.9 min with the GPU-accelerated voxelwise computation, compared to 110 min with the CPU, while both methods result in perfusion parameters differences less than 10(-6). The method will be useful for generating liver perfusion images in clinical settings. PMID:22892645

  15. FATTY ACID CHAIN-ELONGATION IN PERFUSED RAT HEART: SYNTHESIS OF STEAROYLCARNITINE FROM PERFUSED PALMITATE

    PubMed Central

    Kerner, Janos; Minkler, Paul E.; Lesnefsky, Edward J.; Hoppel, Charles L.

    2009-01-01

    Rat hearts perfused for up to 60 min in the working mode with palmitate, but not with glucose, resulted in substantial formation of palmitoylcarnitine and stearoylcarnitine. To test whether lipolysis of endogenous lipids was responsible for the increased stearoylcarnitine content or whether some of the perfused palmitate underwent chain elongation, hearts were perfused with hexadecanoic-16,16,16-d3 acid (M+3). The pentafluorophenacyl ester of deuterium labeled stearoylcarnitine had an M+3 (639.4 m/z) compared to the unlabeled M+0 (636.3 m/z) consistent with a direct chain elongation of the perfused palmitate. Furthermore, the near equal isotope enrichment of palmitoyl- (90.2 ± 5.8 %) and stearoylcarnitine (78.0 ± 7.1 %) suggest that both palmitoyl- and stearoyl-CoA have ready access to mitochondrial carnitine palmitoyltransferase and that most of the stearoylcarnitine is derived from the perfused palmitate. PMID:17761175

  16. Quantitative Perfusion and Permeability Biomarkers in Brain Cancer from Tomographic CT and MR Images

    PubMed Central

    Eilaghi, Armin; Yeung, Timothy; d’Esterre, Christopher; Bauman, Glenn; Yartsev, Slav; Easaw, Jay; Fainardi, Enrico; Lee, Ting-Yim; Frayne, Richard

    2016-01-01

    Dynamic contrast-enhanced perfusion and permeability imaging, using computed tomography and magnetic resonance systems, are important techniques for assessing the vascular supply and hemodynamics of healthy brain parenchyma and tumors. These techniques can measure blood flow, blood volume, and blood–brain barrier permeability surface area product and, thus, may provide information complementary to clinical and pathological assessments. These have been used as biomarkers to enhance the treatment planning process, to optimize treatment decision-making, and to enable monitoring of the treatment noninvasively. In this review, the principles of magnetic resonance and computed tomography dynamic contrast-enhanced perfusion and permeability imaging are described (with an emphasis on their commonalities), and the potential values of these techniques for differentiating high-grade gliomas from other brain lesions, distinguishing true progression from posttreatment effects, and predicting survival after radiotherapy, chemotherapy, and antiangiogenic treatments are presented. PMID:27398030

  17. Ultrasound Contrast Materials in Cardiovascular Medicine: from Perfusion Assessment to Molecular Imaging

    PubMed Central

    Klibanov, Alexander L

    2013-01-01

    Ultrasound imaging is widely used in cardiovascular diagnostics. Contrast agents expand the range of tasks that ultrasound can perform. In the clinic in US, endocardial border delineation and left ventricle opacification have been an approved indication for more than a decade. However, myocardial perfusion contrast ultrasound studies are still at the clinical trials stage. Blood pool contrast and perfusion in other tissues might be an easier indication to achieve: general blood pool ultrasound contrast is in wider use in Europe, Canada, Japan, and China. Targeted (molecular) contrast microbubbles will be the next generation of ultrasound imaging probes, capable of specific delineation of the areas of disease by adherence to molecular targets. The shell of targeted microbubbles (currently in the preclinical research and early stage clinical trials) is decorated with the ligands (antibodies, peptides or mimetics, hormones, carbohydrates) that ensure firm binding to the molecular markers of disease. PMID:23913363

  18. The influence of acute or chronic nicotine treatment on ethanol-induced gastric mucosal damage in rats.

    PubMed

    Cho, C H; Chen, B W; Hui, W M; Lam, S K

    1990-01-01

    The influences of acute or chronic nicotine pretreatment on ethanol-induced changes on gastric secretion, mucosal blood flow (GMBF), and glandular mucosal damage were studied in anesthetized rats. Ethanol administration decreased gastric acid secretion and GMBF, which were accompanied by a marked increase in gastric mucosal damage. Acute nicotine incubation 2 or 4 mg dose-dependently elevated both the titratable acid in the luminal solution and the gastric secretory volume; it also prevented the depressive action on GMBF and gastric mucosal damage in ethanol-treated animals. Chronic nicotine treatment for 10 days reduced the inhibitory action of ethanol on gastric acid secretion; the higher dose (25 micrograms/ml drinking water) potentiated the decrease of GMBF and the ulcerogenic property of ethanol. However, chronic treatment with the lower dose (5 micrograms/ml drinking water) had the opposite effects; it also markedly increased the gastric secretory volume. It is concluded that acute nicotine pretreatment elevates, whereas chronic nicotine pretreatment differentially affects GMBF. These effects could account for their protective or preventive actions on ethanol ulceration. The increase in nonacid gastric secretory volume by nicotine could partially explain its antiulcer effect. Furthermore, the acid secretory state of the stomach appears unrelated to the ulcerogenic property of ethanol. PMID:2295286

  19. Protective effect of histamine microinjected into the cerebellar fastigial nucleus on stress-induced gastric mucosal damage in rats

    PubMed Central

    Qiao, Xiao; Tang, Xiaolong; Zhang, Jianfu; Chen, Ke; Zhang, Yanming; Wang, Changcheng; Fei, Sujuan; Zhu, Jinzhou; Zhu, Shengping; Liu, Zhangbo; Li, Tingting; Lv, Shengxiang; Liang, Yong

    2015-01-01

    Aims: We investigated the effffects and the possible mechanism of microinjection of histamine into cerebellar fastigial nucleus (FN) on stress-induced gastric mucosal damage (SGMD) in rats. The effect of microinjection of histamine into FN on SGMD was observed. Methods: The model of SGMD was established by restraint and water (21 ± 1°C)-immersion (RWI) for 3 h in rats. The gastric mucosal damage index indicated the severity of SGMD. Western blotting was performed to assess gastric mucosal cell apoptosis and proliferation. Results: We observed that histamine microinjection into the FN markedly attenuated SGMD in a dose-dependent manner, and was prevented by pre-treatment with the ranitidine (a selective histamine H2 receptor antagonist) into the FN. The effect of histamine was abolished by pre-treatment with 3-MPA (a glutamic acid decarboxylase antagonist) into the FN. There was a decrease in the discharge frequency of greater splanchnic nerve, and an increase in gastric mucosal blood flow after histamine injection into the FN. Additionally, anti-apoptotic and anti-oxidative factors of gastric mucosa might be involved in this process. Conclusion: The exogenous histamine in FN participates in the regulation of SGMD, and our results may help to provide new ideas on the treatment of gastroenterological diseases. PMID:26550464

  20. Prophylaxis of mucosal toxicity by oral propantheline and cryotherapy in children with malignancies undergoing myeloablative chemo-radiotherapy.

    PubMed

    Sato, Atsushi; Saisho-Hattori, Takako; Koizumi, Yoshitsugu; Minegishi, Masayoshi; Iinuma, Kazuie; Imaizumi, Masue

    2006-12-01

    Mucosal toxicity is an incapacitating complication of intensive chemo-radiotherapy for children with malignant disorders, and is physically and psychologically distressful. It is therefore important to minimize mucosal toxicity in those patients. In this report, the effects of the combined prophylaxis of oral cooling (cryotherapy) and administration of propantheline, an anticholinergic drug, were studied in patients (aged 2-16 year) with acute leukemias or solid tumors, who underwent myeloablative chemo-radiotherapy and autologous peripheral blood stem cell rescue from 1993 to 1997. Patients were pretreated with the combined prophylaxis (n = 12) or single prophylaxis (n = 5), or left untreated (n = 7). The combined prophylaxis significantly reduced the severe mucositis (combined, 8.3%; single, 20.0%; and untreated, 42.9%) and severe diarrhea (combined, 16.7%; single, 60.0%; and untreated, 57.1%). Moreover, the combined prophylaxis tended to shorten the periods of febrile episodes defined as temperature > 38 degrees C (combined, 3.8 days; single, 4.6 days; and untreated, 5.6 days). Therefore, the combination of propantheline and oral cryotherapy may be feasible and effective for reduction of mucosal toxicity in patients with malignancy who undergo high-dose chemotherapy. PMID:17146197