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Sample records for mucosal blood perfusion

  1. Enhancement of gastric mucosal blood flow with sulglycotide.

    PubMed

    Guslandi, M; Sorghi, M; Tittobello, A

    1994-01-01

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

  2. 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.

  3. Asynchronicity of facial blood perfusion in migraine.

    PubMed

    Zaproudina, Nina; Teplov, Victor; Nippolainen, Ervin; Lipponen, Jukka A; Kamshilin, Alexei A; Närhi, Matti; Karjalainen, Pasi A; Giniatullin, Rashid

    2013-01-01

    Asymmetrical changes in blood perfusion and asynchronous blood supply to head tissues likely contribute to migraine pathophysiology. Imaging was widely used in order to understand hemodynamic variations in migraine. However, mapping of blood pulsations in the face of migraineurs has not been performed so far. We used the Blood Pulsation Imaging (BPI) technique, which was recently developed in our group, to establish whether 2D-imaging of blood pulsations parameters can reveal new biomarkers of migraine. BPI characteristics were measured in migraineurs during the attack-free interval and compared to healthy subjects with and without a family history of migraine. We found a novel phenomenon of transverse waves of facial blood perfusion in migraineurs in contrast to healthy subjects who showed synchronous blood delivery to both sides of the face. Moreover, the amplitude of blood pulsations was symmetrically distributed over the face of healthy subjects, but asymmetrically in migraineurs and subjects with a family history of migraine. In the migraine patients we found a remarkable correlation between the side of unilateral headache and the direction of the blood perfusion wave. Our data suggest that migraine is associated with lateralization of blood perfusion and asynchronous blood pulsations in the facial area, which could be due to essential dysfunction of the autonomic vascular control in the face. These findings may further enhance our understanding of migraine pathophysiology and suggest new easily available biomarkers of this pathology.

  4. 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

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

    PubMed

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

    1991-04-01

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

  6. 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.

  7. 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.

  8. 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.

  9. The oral mucosal surface and blood vessels

    PubMed Central

    2013-01-01

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

  10. 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.

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

    SciTech Connect

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

    1986-02-01

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

  12. 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.

  13. Skin blood perfusion and oxygenation colour affect perceived human health.

    PubMed

    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.

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

    PubMed

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

    1984-07-01

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

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

    PubMed Central

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

    1994-01-01

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

  16. 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.

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-08-01

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

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

    PubMed

    Fujita, S; Tamazawa, M; Kuroda, K

    1998-09-01

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

  20. 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.

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

    PubMed

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

    2005-01-01

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

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

    PubMed

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

    2007-01-05

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

  3. 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.

  4. [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.

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

    PubMed Central

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

    1998-01-01

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

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

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

    NASA Astrophysics Data System (ADS)

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

    2006-03-01

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

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

    PubMed

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

    2016-12-01

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

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

    PubMed

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

    2015-01-01

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

  9. 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.

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

    NASA Astrophysics Data System (ADS)

    Wang, Ruikang K.

    2007-12-01

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

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

    PubMed

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

    2002-12-02

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

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

    PubMed

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

    2012-01-01

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

  13. 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

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

    PubMed Central

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

    1994-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

    Brooks, W W; Apstein, C S

    1996-08-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

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

    PubMed

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

    2016-09-19

    Red blood cells (RBCs) suspended in plasma form multicellular aggregates under low flow conditions, increasing apparent blood viscosity at low shear rates. It has previously been unclear, however, if RBC aggregation affects microvascular perfusion. Here we analyzed the impact of RBC aggregation on perfusion and 'capillary' hematocrit in an artificial microvascular network (AMVN) at driving pressures ranging from 5 to 60 cmH2 O to determine if aggregation could improve tissue oxygenation. RBCs were suspended at 30% hematocrit in either 46.5 g/L dextran 40 (D40, non-aggregating medium) or 35 g/L dextran 70 (D70, aggregating medium) solutions with equal viscosity. Aggregation was readily observed in the AMVN for RBCs suspended in D70 at driving pressures ≤ 40 cmH2 O. The AMVN perfusion rate was the same for RBCs suspended in aggregating and non-aggregating medium, at both 'venular' and 'capillary' level. Estimated 'capillary' hematocrit was higher for D70 suspensions than for D40 suspensions at intermediate driving pressures (5 - 40 cm H2 O). We conclude that although RBC aggregation did not affect the AMVN perfusion rate independently of the driving pressure, a higher hematocrit in the 'capillaries' of the network for D70 suspensions suggested a better oxygen transport capacity in the presence of RBC aggregation. This article is protected by copyright. All rights reserved.

  20. 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.

  1. 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.

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

    SciTech Connect

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

    2011-01-01

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

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

    PubMed

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

    2014-04-01

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

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

    PubMed Central

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

    2014-01-01

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

  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. 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)

  7. 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.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2008-03-01

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

  10. 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.

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

    PubMed

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

    2015-12-17

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

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

    PubMed

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

    1976-04-01

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

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

    SciTech Connect

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

    1983-03-18

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed

    Schmidl, Doreen; Garhofer, Gerhard; Schmetterer, Leopold

    2011-08-01

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

  16. 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.

  17. 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

  18. 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.

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

    PubMed

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

    2003-10-01

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

  20. 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

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

    NASA Astrophysics Data System (ADS)

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

    2004-01-01

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

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

    PubMed Central

    Malavasi, Silvia; Barone, Domenico; Gavelli, Giampaolo

    2017-01-01

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

  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 5 minutes, capillary blood flow was measured in the buccal mucosa at 5-minute intervals using a laser Doppler probe, and the results were expressed as arbitrary perfusion units. There was a wide variation in results and a small but significant rise (p=0.008) as a result of nicotine vaping, but these fell to the same levels as before within 30 minutes. Electronic cigarettes may have an effect on blood flow to the oral mucosa, although further studies are needed to show whether they improve healing time after operation. Additional work is also needed to compare them with cigarettes.

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

    PubMed

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

    2001-10-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2005-04-01

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

  6. 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.

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

    PubMed

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

    2009-03-01

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

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

    PubMed

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

    2016-10-01

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

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

    PubMed

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

    2017-02-16

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

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

    PubMed

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

    2014-01-01

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

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

    PubMed

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

    2014-04-01

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

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

    PubMed

    Jia, Yali; Wang, Ruikang K

    2011-01-01

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

  13. 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.

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

    PubMed

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

    1989-07-01

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

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

    PubMed Central

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

    1977-01-01

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

  16. 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

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

    PubMed

    Rafiq, Aasma; Khanday, M A

    2016-12-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2015-11-01

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

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

    PubMed

    Wang, Ruikang K; Hurst, Sawan

    2007-09-03

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

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

    PubMed

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

    2013-01-01

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

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

    PubMed

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

    2016-11-01

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

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

    PubMed

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

    2011-10-01

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

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

    PubMed

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

    2007-09-01

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

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

    PubMed

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

    2013-05-01

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

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

    PubMed

    Homma, Y; Ichinohe, T; Kaneko, Y

    1999-04-01

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

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

    PubMed

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

    2015-09-24

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

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

    PubMed

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

    2001-10-01

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

  9. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  11. Distribution of lung blood on modified bilateral Glenn shunt evaluated by Tc-99m-MAA lung perfusion scintigraphy: A retrospective study.

    PubMed

    Si, Biao; Luan, Zhao-Sheng; Wang, Tong-Jian; Ning, Yan-Song; Li, Na; Zhu, Meng; Liu, Zhong-Min; Ding, Guang-Hong; Qiao, Bin

    2016-09-01

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

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

    PubMed

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

    2016-12-16

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

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

    PubMed

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

    2014-10-01

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

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

    PubMed Central

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

    2016-01-01

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

  15. 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.

  16. 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

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

    PubMed

    Williams, Monica; Lee, Jennifer K

    2014-07-01

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

  18. 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.

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

    PubMed

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

    1989-01-01

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

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

    PubMed

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

    2014-05-01

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

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

    PubMed

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

    2017-03-01

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

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

    PubMed Central

    Himori, N.; Taira, N.

    1977-01-01

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

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

    PubMed

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

    2004-07-01

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

  4. 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

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

    PubMed

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

    2010-04-01

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

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

    PubMed

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

    2010-08-01

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

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

    PubMed

    Wang, Ze

    2012-12-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed

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

    2013-07-01

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

  10. 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.

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

    PubMed Central

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

    2010-01-01

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

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

    PubMed

    Henriksen, L

    1986-06-01

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

  13. 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.

  14. 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.

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

    PubMed

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

    2014-06-01

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

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

    PubMed

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

    2017-01-01

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

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

    PubMed

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

    2015-08-01

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

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

    PubMed

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

    2008-05-01

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

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

    PubMed

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

    2010-01-01

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

  20. 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...

  1. 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...

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

    PubMed Central

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

    2015-01-01

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

  3. 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.

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

    PubMed

    Kowalewski, K; Kolodej, A

    1976-01-01

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

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

    PubMed

    Buell, M G; Beck, I T

    1983-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  8. 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.

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

    PubMed

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

    2017-04-01

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

  10. 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.

  11. Renal perfusion scintiscan

    MedlinePlus

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

  12. 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

  13. Quantification of pulmonary blood flow (PBF): validation of perfusion MRI and nonlinear contrast agent (CA) dose correction with H(2)15O positron emission tomography (PET).

    PubMed

    Neeb, Daniel; Kunz, Rainer Peter; Ley, Sebastian; Szábo, Gábor; Strauss, Ludwig G; Kauczor, Hans-Ulrich; Kreitner, Karl-Friedrich; Schreiber, Laura Maria

    2009-08-01

    Validation of quantification of pulmonary blood flow (PBF) with dynamic, contrast-enhanced MRI is still missing. A possible reason certainly lies in difficulties based on the nonlinear dependence of signal intensity (SI) from contrast agent (CA) concentration. Both aspects were addressed in this study. Nine healthy pigs were examined by first-pass perfusion MRI using gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) and H(2)(15)O positron emission tomography (PET) imaging. Calculations of hemodynamic parameters were based on a one-compartment model (MR) and a two-compartment model (PET). Simulations showed a significant error when assuming a linear relation between MR SI and CA dose in the arterial input function (AIF), even at low doses of 0.025 mmol/kg body weight (BW). To correct for nonlinearity, a calibration curve was calculated on the basis of the signal equation. The required accuracy of equation parameters (like longitudinal relaxation time) was evaluated. Error analysis estimates <5% over-/underestimation of the corrected SI. Comparison of PET and MR flow values yielded a significant correlation (P < 0.001) in dorsal regions where signal-to-noise ratio (SNR) was sufficient. Changes in PBF due to the correction method were significant (P < 0.001) and resulted in a better agreement: mean values (standard deviation) in units of ml/min/100 ml lung tissue were 59 (15) for PET, 112 (28) for uncorrected MRI, and 80 (21) for corrected MRI.

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

    PubMed

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

    2015-03-01

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

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

    PubMed

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

    1993-03-01

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

  16. 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

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

    PubMed

    Hussein, Hassan A

    2013-04-15

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

  18. 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.

  19. 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.

  20. 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 therapy - mouth ...

  1. 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...

  2. Radiation Induced Oral Mucositis

    PubMed Central

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

    2009-01-01

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

  3. 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…

  4. 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...

  5. 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

  6. Effects of different types of hydroxyethyl starch (HES) on microcirculation perfusion and tissue oxygenation in patients undergoing liver surgery.

    PubMed

    Cui, Yinghua; Sun, Bo; Wang, Changsong; Liu, Shujuan; Li, Peng; Shi, Jinghui; Li, Enyou

    2014-01-01

    To compare the effects of hydroxyethyl starch (HES) 130/0.4 and HES 200/0.5, which have different molecular weights and degrees of substitution, on microcirculation perfusion and tissue oxygenation in patients undergoing liver surgery. Thirty patients with an American Society of Anesthesiologists status I/II who were scheduled for liver surgery were randomly divided into two groups: one received an intraoperative HES 130/0.4 infusion equal to the amount of blood loss (HES 130/0.4 group, n=15), and the other received HES 200/0.5 equal to the amount of blood loss (HES 200/0.5 group, n=15). Gastric mucosal perfusion and tissue oxygenation were monitored by measuring the gastric mucosal pH (pHi), which was determined using a carbon dioxide tonometer inserted through a nasogastric tube. Gastric mucosal pHi , hemodynamic parameters, body temperature, and blood gas parameters were recorded upon entering the operating room, before skin incision, one hour and two hours after skin incision, and at the end of surgery. The intraoperative pHi decreased in both groups of patients, but the decline in the HES 130/0.4 group was smaller than that of the HES 200/0.5 group. The pHi of the HES 130/0.4 group was significantly higher than that of the HES 200/0.5 group two hours after skin incision and at the end of surgery (P<0.05). A multivariate analysis showed that the type of colloid used intraoperatively was the only variant that affected pHi (F=0.626, P<0.05). Moreover, there were good correlation between pHi at the end of surgery and the length of postoperative hospital stay (r=-0.536, P<0.05) and the time intervals from surgery to the passage of flatus (r=-0.547, P<0.05). Compared with HES 200/0.5, the use of HES 130/0.4 (with a relatively lower molecular weight and lower degree of substitution) could significantly improve internal organ perfusion and tissue oxygenation in patients undergoing liver surgery with a relatively large amount of blood loss.

  7. Organic Nitrate Maintains Bone Marrow Blood Perfusion in Ovariectomized Female Rats: A Dynamic, Contrast-Enhanced Magnetic Resonance Imaging (MRI) Study

    PubMed Central

    Wang, Yi-Xiang J.; Ko, Chun Hay; Griffith, James F.; Deng, Min; Wong, Hing Lok; Gu, Tao; Huang, Yu

    2012-01-01

    This study investigated the effects of nitrate on bone mineral density (BMD) and bone marrow perfusion in ovariectomized (OVX) female rats, and also the effects of nitrate on in vitro osteoblastic activity and osteoclastic differentiation of murine monocyte/macrophage RAW 264.7 cells. Female Sprague–Dawley rats were divided into OVX + nitrate group (isosorbide-5-mononitrate, ISM, 150 mg/kg/ day b.i.d), OVX + vehicle group, and control group. Lumbar spine CT bone densitometry and perfusion MRI were performed on the rats at baseline and week 8 post-OVX. The OVX rats’ BMD decreased by 22.5% ± 5.7% at week 8 (p < 0.001); while the OVX + ISM rats’ BMD decreased by 13.1% ± 2.7% (p < 0.001). The BMD loss difference between the two groups of rats was significant (p = 0.018). The OVX rats’ lumbar vertebral perfusion MRI maximum enhancement (Emax) decreased by 10.3% ± 5.0% at week 8 (p < 0.005), while in OVX + ISM rats, the Emax increased by 5.5% ± 6.9% (p > 0.05). The proliferation of osteoblast-like UMR-106 cells increased significantly with ISM treatment at 0.78 µM to 50 μM. Treatment of UMR-106 cells with ISM also stimulated the BrdU uptake. After the RAW 264.7 cells were co-treated with osteoclastogenesis inducer RANKL and 6.25 μM ~ 100 μM of ISM for 3 days, a trend of dose-dependent increase of osteoclast number was noted. PMID:24300395

  8. The Mouse Isolated Perfused Kidney Technique.

    PubMed

    Czogalla, Jan; Schweda, Frank; Loffing, Johannes

    2016-11-17

    The mouse isolated perfused kidney (MIPK) is a technique for keeping a mouse kidney under ex vivo conditions perfused and functional for 1 hr. This is a prerequisite for studying the physiology of the isolated organ and for many innovative applications that may be possible in the future, including perfusion decellularization for kidney bioengineering or the administration of anti-rejection or genome-editing drugs in high doses to prime the kidney for transplantation. During the time of the perfusion, the kidney can be manipulated, renal function can be assessed, and various pharmaceuticals administered. After the procedure, the kidney can be transplanted or processed for molecular biology, biochemical analysis, or microscopy. This paper describes the perfusate and the surgical technique needed for the ex vivo perfusion of mouse kidneys. Details of the perfusion apparatus are given and data are presented showing the viability of the kidney's preparation: renal blood flow, vascular resistance, and urine data as functional, transmission electron micrographs of different nephron segments as morphological readouts, and western blots of transport proteins of different nephron segments as molecular readout.

  9. Measurement of continuous distributions of ventilation-perfusion ratios - Theory

    NASA Technical Reports Server (NTRS)

    Wagner, P. D.; Saltzman, H. A.; West, J. B.

    1974-01-01

    The resolution of the technique considered is sufficient to describe smooth distributions containing blood flow to unventilated regions (shunt), ventilation to unperfused regions (dead space), and up to three additional modes over the range of finite ventilation-perfusion ratios. In particular, areas whose ventilation-perfusion ratios are low can be separated from unventilated regions and those whose ventilation-perfusion ratios are high can similarly be distinguished from unperfused areas.

  10. Blood

    MedlinePlus

    ... The liquid part, called plasma, is made of water, salts, and protein. Over half of your blood is plasma. The solid part of your blood contains red blood cells, white blood cells, and platelets. Red ...

  11. Temporal and concentration effects of isoflurane anaesthesia on intestinal tissue oxygenation and perfusion in horses.

    PubMed

    Hopster, K; Hopster-Iversen, C; Geburek, F; Rohn, K; Kästner, S B R

    2015-07-01

    The aim of this study was to assess the effect of duration of anaesthesia and concentration of isoflurane on global perfusion as well as intestinal microperfusion and oxygenation. Nine Warmblood horses were premedicated with xylazine; anaesthesia was induced with midazolam and ketamine, and maintained with isoflurane. Horses were ventilated to normocapnia. During 7 h of anaesthesia, mean arterial blood pressures (MAP), heart rate, central venous pressure, pulmonary artery pressure, expiratory isoflurane concentration (ETIso) and cardiac output using lithium dilution were measured; cardiac index (CI) was calculated. Intestinal microperfusion and oxygenation were measured using laser Doppler flowmetry and white-light spectrophotometry. Surface probes were placed via median laparotomy on the serosal and mucosal site of the jejunum and the pelvic flexion of the colon. After 3 h of constant ETIso (1.4%), ETIso was increased in 0.2% increments up to 2.4%, followed by a decrease to 1.2% and an increase to 1.4%. The CI and MAP decreased continuously with increasing ETIso to 40 ± 5 mL/kg/min and 52 ± 8 mmHg, respectively. Microperfusion and oxygenation remained unchanged until an ETIso of 2.0% resulted in CI and MAP of 48 ± 5 mL/kg/min and 62 ± 6 mmHg, respectively, and then decreased rapidly. When ETIso decreased back to baseline, CI, MAP, microperfusion and oxygenation recovered to baseline. Isoflurane concentration but not duration of isoflurane anaesthesia influenced central and intestinal oxygenation and perfusion in healthy horses. Under isoflurane, intestinal perfusion appeared to be preserved until a threshold MAP or blood flow was reached.

  12. Prevention of acute gastric mucosal lesions by Solcoseryl.

    PubMed

    Brzozowski, T; Radecki, T; Sendur, R; Gustaw, P; Konturek, S J

    1987-04-01

    Solcoseryl, a deproteinized extract from calf blood containing various biologically active substances, has been reported to promote the healing of skin wounds and gastric ulceration In this study, the gastroprotective effects of Solcoseryl vis-a-vis acute gastric mucosal damage were examined in rats. Solcoseryl significantly reduced the formation of acute lesions induced by intragastric application of absolute ethanol or acidified taurocholate and by water immersion and restraint stress, but failed to affect those caused by acidified aspirin. Since Solcoseryl did not offer protection in the absence of mucosal prostaglandins (PG) e.g. in aspirin-induced gastric damage, it is likely that PG may be involved in the observed gastroprotective activity of the drug. Solcoseryl failed to affect gastric acid or pepsin secretion, but increased mucosal blood flow. Thus PG generated by Solcoseryl might contribute to the maintenance of the observed mucosal microcirculation and the prevention of lesion formation by corrosive substances and stress conditions.

  13. Sex differences and effects of oestrogen in rat gastric mucosal defence

    PubMed Central

    Shore, Richard; Björne, Håkan; Omoto, Yoko; Siemiatkowska, Anna; Gustafsson, Jan-Åke; Lindblad, Mats; Holm, Lena

    2017-01-01

    AIM To evaluate sex differences and the effects of oestrogen administration in rat gastric mucosal defence. METHODS Sex differences in gastric mucus thickness and accumulation rate, absolute gastric mucosal blood flow using microspheres, the integrity of the gastric mucosal epithelium in response to a chemical irritant and the effects of oestrogen administration on relative gastric mucosal blood flow in an acute setting was assessed in an in vivo rat experimental model. Subsequently, sex differences in the distribution of oestrogen receptors and calcitonin gene related peptide in the gastric mucosa of animals exposed to oestrogen in the above experiments was evaluated using immunohistochemistry. RESULTS The absolute blood flow in the GI-tract was generally higher in males, but only significantly different in the corpus part of the stomach (1.12 ± 0.12 mL/min•g in males and 0.51 ± 0.03 mL/min•g in females) (P = 0.002). After removal of the loosely adherent mucus layer the thickness of the firmly adherent mucus layer in males and females was 79 ± 1 µm and 80 ± 3 µm respectively. After 60 min the mucus thickness increased to 113 ± 3 µm in males and 121 ± 3 µm in females with no statistically significant difference seen between the sexes. Following oestrogen administration (0.1 followed by 1 µg/kg•min), mean blood flow in the gastric mucosa decreased by 31% [68 ± 13 perfusion units (PFU)] in males which was significantly different compared to baseline (P = 0.02). In females however, mean blood flow remained largely unchanged with a 4% (5 ± 33 PFU) reduction. The permeability of the gastric mucosa increased to a higher level in females than in males (P = 0.01) after taurocholate challenge. However, the calculated mean clearance increase did not significantly differ between the sexes [0.1 ± 0.04 to 1.1 ± 0.1 mL/min•100 g in males and 0.4 ± 0.3 to 2.1 ± 0.3 mL/min•100 g in females (P = 0.065)]. There were no significant differences between 17

  14. Evaluation of Laser Speckle Contrast Imaging for the Assessment of Oral Mucosal Blood Flow following Periodontal Plastic Surgery: An Exploratory Study.

    PubMed

    Molnár, Eszter; Molnár, Bálint; Lohinai, Zsolt; Tóth, Zsuzsanna; Benyó, Zoltán; Hricisák, Laszló; Windisch, Péter; Vág, János

    2017-01-01

    The laser speckle contrast imaging (LSCI) is proved to be a reliable tool in flap monitoring in general surgery; however, it has not been evaluated in oral surgery yet. We applied the LSCI to compare the effect of a xenogeneic collagen matrix (Geistlich Mucograft®) to connective tissue grafts (CTG) on the microcirculation of the modified coronally advanced tunnel technique (MCAT) for gingival recession coverage. Gingival microcirculation and wound fluid were measured before and after surgery for six months at twenty-seven treated teeth. In males, the flap microcirculation was restored within 3 days for both grafts followed by a hyperemic response. During the first 8 days the blood flow was higher at xenogeneic graft comparing to the CTG. In females, the ischemic period lasted for 7-12 days depending on the graft and no hyperemic response was observed. Females had more intense and prolonged wound fluid production. The LSCI method is suitable to capture the microcirculatory effect of the surgical intervention in human oral mucosa. The application of xenogeneic collagen matrices as a CTG substitute does not seem to restrain the recovery of graft bed circulation. Gender may have an effect on postoperative circulation and inflammation.

  15. Evaluation of Laser Speckle Contrast Imaging for the Assessment of Oral Mucosal Blood Flow following Periodontal Plastic Surgery: An Exploratory Study

    PubMed Central

    Molnár, Eszter; Molnár, Bálint; Lohinai, Zsolt; Tóth, Zsuzsanna; Benyó, Zoltán; Hricisák, Laszló; Windisch, Péter

    2017-01-01

    The laser speckle contrast imaging (LSCI) is proved to be a reliable tool in flap monitoring in general surgery; however, it has not been evaluated in oral surgery yet. We applied the LSCI to compare the effect of a xenogeneic collagen matrix (Geistlich Mucograft®) to connective tissue grafts (CTG) on the microcirculation of the modified coronally advanced tunnel technique (MCAT) for gingival recession coverage. Gingival microcirculation and wound fluid were measured before and after surgery for six months at twenty-seven treated teeth. In males, the flap microcirculation was restored within 3 days for both grafts followed by a hyperemic response. During the first 8 days the blood flow was higher at xenogeneic graft comparing to the CTG. In females, the ischemic period lasted for 7–12 days depending on the graft and no hyperemic response was observed. Females had more intense and prolonged wound fluid production. The LSCI method is suitable to capture the microcirculatory effect of the surgical intervention in human oral mucosa. The application of xenogeneic collagen matrices as a CTG substitute does not seem to restrain the recovery of graft bed circulation. Gender may have an effect on postoperative circulation and inflammation. PMID:28232940

  16. Blood

    MedlinePlus

    ... that die or are lost from the body. White Blood Cells White blood cells (WBCs, and also ... of severe pain. previous continue Diseases of the White Blood Cells Neutropenia (pronounced: new-truh-PEE-nee- ...

  17. The human milk oligosaccharide 2'-fucosyllactose attenuates the severity of experimental necrotising enterocolitis by enhancing mesenteric perfusion in the neonatal intestine.

    PubMed

    Good, Misty; Sodhi, Chhinder P; Yamaguchi, Yukihiro; Jia, Hongpeng; Lu, Peng; Fulton, William B; Martin, Laura Y; Prindle, Thomas; Nino, Diego F; Zhou, Qinjie; Ma, Congrong; Ozolek, John A; Buck, Rachael H; Goehring, Karen C; Hackam, David J

    2016-10-01

    Necrotising enterocolitis (NEC) is a common disease in premature infants characterised by intestinal ischaemia and necrosis. The only effective preventative strategy against NEC is the administration of breast milk, although the protective mechanisms remain unknown. We hypothesise that an abundant human milk oligosaccharide (HMO) in breast milk, 2'-fucosyllactose (2'FL), protects against NEC by enhancing intestinal mucosal blood flow, and we sought to determine the mechanisms underlying this protection. Administration of HMO-2'FL protected against NEC in neonatal wild-type mice, resulted in a decrease in pro-inflammatory markers and preserved the small intestinal mucosal architecture. These protective effects occurred via restoration of intestinal perfusion through up-regulation of the vasodilatory molecule endothelial nitric oxide synthase (eNOS), as administration of HMO-2'FL to eNOS-deficient mice or to mice that received eNOS inhibitors did not protect against NEC, and by 16S analysis HMO-2'FL affected the microbiota of the neonatal mouse gut, although these changes do not seem to be the primary mechanism of protection. Induction of eNOS by HMO-2'FL was also observed in cultured endothelial cells, providing a link between eNOS and HMO in the endothelium. These data demonstrate that HMO-2'FL protects against NEC in part through maintaining mesenteric perfusion via increased eNOS expression, and suggest that the 2'FL found in human milk may be mediating some of the protective benefits of breast milk in the clinical setting against NEC.

  18. Mucosal melanoma: an update.

    PubMed

    Ballester Sánchez, R; de Unamuno Bustos, B; Navarro Mira, M; Botella Estrada, R

    2015-03-01

    Mucosal melanoma is a rare melanoma subtype that differs from the cutaneous form of the tumor in its biology, clinical manifestations, and management. Diagnosis is usually late due to a lack of early or specific signs and the location of lesions in areas that are difficult to access on physical examination. Surgical excision is the treatment of choice for localized disease. The value of sentinel lymph node biopsy and lymphadenectomy is still unclear. Radiotherapy can be used as adjuvant therapy for the control of local disease. c-KIT mutations are more common than in other types of melanoma and this has led to significant advances in the use of imatinib for the treatment of metastatic mucosal melanoma.

  19. 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.

  20. 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.

  1. 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

  2. Kidneys From α1,3-Galactosyltransferase Knockout/Human Heme Oxygenase-1/Human A20 Transgenic Pigs Are Protected From Rejection During Ex Vivo Perfusion With Human Blood

    PubMed Central

    Ahrens, Hellen E.; Petersen, Björn; Ramackers, Wolf; Petkov, Stoyan; Herrmann, Doris; Hauschild-Quintern, Janet; Lucas-Hahn, Andrea; Hassel, Petra; Ziegler, Maren; Baars, Wiebke; Bergmann, Sabine; Schwinzer, Reinhard; Winkler, Michael; Niemann, Heiner

    2015-01-01

    Background Multiple modifications of the porcine genome are required to prevent rejection after pig-to-primate xenotransplantation. Here, we produced pigs with a knockout of the α1,3-galactosyltransferase gene (GGTA1-KO) combined with transgenic expression of the human anti-apoptotic/anti-inflammatory molecules heme oxygenase-1 and A20, and investigated their xenoprotective properties. Methods The GGTA1-KO/human heme oxygenase-1 (hHO-1)/human A20 (hA20) transgenic pigs were produced in a stepwise approach using zinc finger nuclease vectors targeting the GGTA1 gene and a Sleeping Beauty vector coding for hA20. Two piglets were analyzed by quantitative reverse-transcription polymerase chain reaction, flow cytometry, and sequencing. The biological function of the genetic modifications was tested in a 51Chromium release assay and by ex vivo kidney perfusions with human blood. Results Disruption of the GGTA1 gene by deletion of few basepairs was demonstrated in GGTA1-KO/hHO-1/hA20 transgenic pigs. The hHO-1 and hA20 mRNA expression was confirmed by quantitative reverse-transcription polymerase chain reaction. Ex vivo perfusion of 2 transgenic kidneys was feasible for the maximum experimental time of 240 minutes without symptoms of rejection. Conclusions Results indicate that GGTA1-KO/hHO-1/hA20 transgenic pigs are a promising model to alleviate rejection and ischemia-reperfusion damage in porcine xenografts and could serve as a background for further genetic modifications toward the production of a donor pig that is clinically relevant for xenotransplantation. PMID:27500225

  3. 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.

  4. Perfusion phantom: An efficient and reproducible method to simulate myocardial first-pass perfusion measurements with cardiovascular magnetic resonance.

    PubMed

    Chiribiri, Amedeo; Schuster, Andreas; Ishida, Masaki; Hautvast, Gilion; Zarinabad, Niloufar; Morton, Geraint; Otton, James; Plein, Sven; Breeuwer, Marcel; Batchelor, Philip; Schaeffter, Tobias; Nagel, Eike

    2013-03-01

    The aim of this article is to describe a novel hardware perfusion phantom that simulates myocardial first-pass perfusion allowing comparisons between different MR techniques and validation of the results against a true gold standard. MR perfusion images were acquired at different myocardial perfusion rates and variable doses of gadolinium and cardiac output. The system proved to be sensitive to controlled variations of myocardial perfusion rate, contrast agent dose, and cardiac output. It produced distinct signal intensity curves for perfusion rates ranging from 1 to 10 mL/mL/min. Quantification of myocardial blood flow by signal deconvolution techniques provided accurate measurements of perfusion. The phantom also proved to be very reproducible between different sessions and different operators. This novel hardware perfusion phantom system allows reliable, reproducible, and efficient simulation of myocardial first-pass MR perfusion. Direct comparison between the results of image-based quantification and reference values of flow and myocardial perfusion will allow development and validation of accurate quantification methods.

  5. Effect of spinal cord compression on local vascular blood flow and perfusion capacity by Alshareef M, Krishna V, Ferdous J, Aishareef A, Kindy M, Kolachalama VB, et al.

    PubMed Central

    Epstein, Nancy E.

    2016-01-01

    Background: Different degrees of blood flow/vascular compromise occur with anterior, posterior, or circumferential spinal cord compression/spinal cord injury (SCI). SCI is also divided into primary and secondary injury. Primary SCI refers to the original neurological damage to tissues, whereas secondary injury reflects interruption of normal blood flow leading to further inflammatory response/other local changes which contribute to additional neurological injury. Methods: The authors developed a quantitative “3-D finite element fluid structure interaction model” of spinal cord blood flow to better document the mechanisms of secondary ischemic damage occurring in the spinal cord anteriorly, posteriorly, or circumferentially. This included assessment of the anterior spinal artery (ASA) and five arterial branches (L1, L2, L3, R1, R2), but excluded the microvasculature. Results: Different locations of cord compression resulted in alternative patterns of spinal cord ischemia. Anterior spinal artery (ASA) flow was substantially reduced by direct anterior compression, but resulted in the least vascular compromise. Alternatively, posterior compression resulted in a significant and critical reduction of distal ASA blood flow and, therefore, correlated with the greatest susceptibility to acute ischemia. Counterintuitively, they concluded “at equivalent degrees of dural occlusion, the loss of branch blood flow under anterior posterior compression was intermediate to predictions for purely posterior or anterior loading.” Conclusion: Utilizing a computational three-dimensional model, Alshareef et al. observed that anterior cervical cord compression resulted in the least severe compromise of ASA blood flow to the spinal cord, whereas posterior cord compression/SCI maximally reduced distal ASA blood flow potentiating acute ischemia. Therefore, the latter warranted the earliest surgical intervention. PMID:27843686

  6. Characterization of intestinal collateral blood flow in the developing piglet.

    PubMed

    Crissinger, K D; Granger, D N

    1988-10-01

    Interest in the pathogenesis of neonatal necrotizing enterocolitis has prompted study of the intestinal circulation in developing animals. It is conceivable that poorly developed collateral channels may predispose the neonatal intestine to ischemic insults. We therefore characterized intestinal collateral blood flow in anesthetized and ventilated 1-day and 1-month-old piglets. Intestinal blood flow was measured with radioactive microspheres (15 micron diameter) before and after either 1) total occlusion of the superior mesenteric artery (SMA) or 2) occlusion of a distal (jejunoileal) branch of the SMA. After total SMA occlusion in 1-day and 1-month-old piglets, perfusion of the intestine via collaterals from the celiac and inferior mesenteric arteries was not evident. Jejunal, ileal, and colonic (except rectal) blood flows fell to zero 30 min after ligation of the SMA. Ligation of a distal branch of the SMA in 1-month-old animals significantly reduced total wall (by 25%) and mucosal/submucosal (by 25%) blood flows in the occluded segment. Similar experiments in 1-day-old piglets produced significantly greater reduction in total (70%) and mucosa/submucosa (70%) blood flows. Muscle/serosa blood flows in both groups were not significantly different from control values. In conclusion, collateral perfusion of the intestine via the celiac and inferior mesenteric arteries is insignificant during acute SMA occlusion in the developing piglet. Although there is significant collateral blood flow within the SMA vascular network, perfusion between adjacent gut segments is less effective in preventing intestinal ischemia after occlusion of a branch of the SMA in neonates than in 1-month-old piglets.

  7. Imaging of myocardial perfusion with magnetic resonance.

    PubMed

    Barkhausen, Jörg; Hunold, Peter; Jochims, Markus; Debatin, Jörg F

    2004-06-01

    Coronary artery disease (CAD) is currently the leading cause of death in developed nations. Reflecting the complexity of cardiac function and morphology, noninvasive diagnosis of CAD represents a major challenge for medical imaging. Although coronary artery stenoses can be depicted with magnetic resonance (MR) and computed tomography (CT) techniques, its functional or hemodynamic impact frequently remains elusive. Therefore, there is growing interest in other, target organ-specific parameters such as myocardial function at stress and first-pass myocardial perfusion imaging to assess myocardial blood flow. This review explores the pathophysiologic background, recent technical developments, and current clinical status of first-pass MR imaging (MRI) of myocardial perfusion.

  8. Abdominal perfusion computed tomography.

    PubMed

    Ogul, Hayri; Bayraktutan, Ummugulsum; Kizrak, Yesim; Pirimoglu, Berhan; Yuceler, Zeynep; Sagsoz, M Erdem; Yilmaz, Omer; Aydinli, Bulent; Ozturk, Gurkan; Kantarci, Mecit

    2013-02-01

    The purpose of this article is to provide an up to date review on the spectrum of applications of perfusion computed tomography (CT) in the abdomen. New imaging techniques have been developed with the objective of obtaining a structural and functional analysis of different organs. Recently, perfusion CT has aroused the interest of many researchers who are studying the applicability of imaging modalities in the evaluation of abdominal organs and diseases. Per-fusion CT enables fast, non-invasive imaging of the tumor vascular physiology. Moreover, it can act as an in vivo biomarker of tumor-related angiogenesis.

  9. Abdominal Perfusion Computed Tomography

    PubMed Central

    Ogul, Hayri; Bayraktutan, Ummugulsum; Kizrak, Yesim; Pirimoglu, Berhan; Yuceler, Zeynep; Sagsoz, M. Erdem; Yilmaz, Omer; Aydinli, Bulent; Ozturk, Gurkan; Kantarci, Mecit

    2013-01-01

    The purpose of this article is to provide an up to date review on the spectrum of applications of perfusion computed tomography (CT) in the abdomen. New imaging techniques have been developed with the objective of obtaining a structural and functional analysis of different organs. Recently, perfusion CT has aroused the interest of many researchers who are studying the applicability of imaging modalities in the evaluation of abdominal organs and diseases. Per-fusion CT enables fast, non-invasive imaging of the tumor vascular physiology. Moreover, it can act as an in vivo biomarker of tumor-related angiogenesis. PMID:25610249

  10. Organizing a mucosal defense.

    PubMed

    Newberry, Rodney D; Lorenz, Robin G

    2005-08-01

    Gastrointestinal associated lymphoid tissue can be divided into loosely organized effector sites, which include the lamina propria and intraepithelial lymphocytes, and more organized structures, such as mesenteric lymph nodes (LNs), Peyer's patches (PPs), isolated lymphoid follicles, and cryptopatches (CPs). These organized structures in the gastrointestinal tract have been hypothesized to play the role of primary lymphoid organ, supporting the extrathymic development of T lymphocytes (CPs), secondary lymphoid organs involved in the induction of the mucosal immune response (PPs), and tertiary lymphoid structures whose function is still under debate (isolated lymphoid follicles). The most widely studied lymphoid structure found in the small intestine is the PP. PPs are secondary lymphoid structures, and their development and function have been extensively investigated. However, single lymphoid aggregates resembling PPs have been also described in humans and in the murine small intestines. These isolated lymphoid follicles have both germinal centers and an overlying follicle-associated epithelium, suggesting that they also can function as inductive sites for the mucosal immune response. This review compares and contrasts the development and function of the four main organized gastrointestinal lymphoid tissues: CPs, isolated lymphoid follicles, PPs, and mesenteric LNs.

  11. Effect of carbachol on intestinal mucosal blood flow, activity of Na+-K+-ATPase, expression of aquaporin-1, and intestinal absorption rate during enteral resuscitation of burn shock in rats.

    PubMed

    Bao, Chengmei; Hu, Sen; Zhou, Guoyong; Tian, Yijun; Wu, Yan; Sheng, Zhiyong

    2010-01-01

    We investigated the effect of carbachol (CAR, a cholinergic agent) on intestinal mucosal blood flow (IMBF), activity of Na-K-ATPase, expression of aquaporin (AQP)-1, and intestinal absorption rate during enteral resuscitation of a 35%TBSA scald in rats with a glucose electrolyte solution (GES). One hundred male Wistar rats were randomly divided into five groups: sham scald (N group); scald without fluid resuscitation (S group); scald resuscitated with enteral GES alone (GES group); scald resuscitated with enteral CAR alone (CAR group); and scald resuscitated with enteral CAR plus GES (GES/CAR group). The rats were inflicted 35%TBSA third degree of scald injury on the back with boiling water (100 degrees C, 15 seconds) in all groups, except the sham scald group. A catheter was inserted into the proximal duodenum (5 cm distal to pylorus) and distal ileum (5 cm proximal to cecum), of each rats through laparotomy, thus a segment of intestine was virtually isolated to form a loop for inlet and outlet of introduced fluid. In N, GES, and GES/CAR groups, fluids were introduced 30 minutes after scald injury. The speed of fluid infusion was 4 ml/kg/1%TBSA for 4 hours. CAR (60 microg/kg) was injected into the intestinal lumen at 30-minute after injury in CAR and GES/CAR groups. At 2 and 4 hours after scald, intestinal absorption rate of water and Na, and IMBF were determined, respectively. Then, animals were killed, and specimens of intestinal tissue were obtained for the determination of the activity of Na-K-ATPase, hematoxylin-eosin coloring, and expression of AQP-1. The intestinal absorption rate was reduced markedly in GES group compared with sham scald group at 2 and 4 hours after scald, and absorption rate of small intestine in GES/CAR was significantly higher than that in GES group (P < .05). It was also found that there was significant decrease in IMBF, activity of Na-K-ATPase, and expression of AQP-1 in scald group compared with the sham group. However, in GES

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

    PubMed Central

    Martin, Alastair J.; Alexander, Matthew D.; McCoy, David B.; Cooke, Daniel L.; Lillaney, Prasheel; Moftakhar, Parham; Amans, Matthew R.; Settecase, Fabio; Nicholson, Andrew; Dowd, Christopher F.; Halbach, Van V.; Higashida, Randall T.; McDermott, Michael W.; Saloner, David; Hetts, Steven W.

    2016-01-01

    Background and Purpose To evaluate the ability of IA MR perfusion to characterize meningioma blood supply. Methods Studies were performed in a suite comprised of an x-ray angiography unit and 1.5T MR scanner that permitted intraprocedural patient movement between the imaging modalities. Patients underwent intra-arterial (IA) and intravenous (IV) T2* dynamic susceptibility MR perfusion immediately prior to meningioma embolization. Regional tumor arterial supply was characterized by digital subtraction angiography and classified as external carotid artery (ECA) dural, internal carotid artery (ICA) dural, or pial. MR perfusion data regions of interest (ROIs) were analyzed in regions with different vascular supply to extract peak height, full-width at half-maximum (FWHM), relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and mean transit time (MTT). Linear mixed modeling was used to identify perfusion curve parameter differences for each ROI for IA and IV MR imaging techniques. IA vs. IV perfusion parameters were also directly compared for each ROI using linear mixed modeling. Results 18 ROIs were analyzed in 12 patients. Arterial supply was identified as ECA dural (n = 11), ICA dural (n = 4), or pial (n = 3). FWHM, rCBV, and rCBF showed statistically significant differences between ROIs for IA MR perfusion. Peak Height and FWHM showed statistically significant differences between ROIs for IV MR perfusion. RCBV and MTT were significantly lower for IA perfusion in the Dural ECA compared to IV perfusion. Relative CBF in IA MR was found to be significantly higher in the Dural ICA region and MTT significantly lower compared to IV perfusion. PMID:27802268

  13. 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.

  14. Berberine Reduces Uremia-Associated Intestinal Mucosal Barrier Damage.

    PubMed

    Yu, Chao; Tan, Shanjun; Zhou, Chunyu; Zhu, Cuilin; Kang, Xin; Liu, Shuai; Zhao, Shuang; Fan, Shulin; Yu, Zhen; Peng, Ai; Wang, Zhen

    2016-11-01

    Berberine is one of the main active constituents of Rhizoma coptidis, a traditional Chinese medicine, and has long been used for the treatment of gastrointestinal disorders. The present study was designed to investigate the effects of berberine on the intestinal mucosal barrier damage in a rat uremia model induced by the 5/6 kidney resection. Beginning at postoperative week 4, the uremia rats were treated with daily 150 mg/kg berberine by oral gavage for 6 weeks. To assess the intestinal mucosal barrier changes, blood samples were collected for measuring the serum D-lactate level, and terminal ileum tissue samples were used for analyses of intestinal permeability, myeloperoxidase activity, histopathology, malondialdehyde (MDA) level, and superoxide dismutase (SOD) activity. Berberine treatment resulted in significant decreases in the serum D-lactate level, intestinal permeability, intestinal myeloperoxidase activity, and intestinal mucosal and submucosal edema and inflammation, and the Chiu's scores assessed for intestinal mucosal injury. The intestinal MDA level was reduced and the intestinal SOD activity was increased following berberine treatment. In conclusion, berberine reduces intestinal mucosal barrier damage induced by uremia, which is most likely due to its anti-oxidative activity. It may be developed as a potential treatment for preserving intestinal mucosal barrier function in patients with uremia.

  15. Sodium alginate inhibits methotrexate-induced gastrointestinal mucositis in rats.

    PubMed

    Yamamoto, Atsuki; Itoh, Tomokazu; Nasu, Reishi; Kajiwara, Eiji; Nishida, Ryuichi

    2013-01-01

    Gastrointestinal mucositis is one of the most prevalent side effects of chemotherapy. Methotrexate is a pro-oxidant compound that depletes dihydrofolate pools and is widely used in the treatment of leukemia and other malignancies. Through its effects on normal tissues with high rates of proliferation, methotrexate treatment leads to gastrointestinal mucositis. In rats, methotrexate-induced gastrointestinal mucositis is histologically characterized by crypt loss, callus fusion and atrophy, capillary dilatation, and infiltration of mixed inflammatory cells. The water-soluble dietary fiber sodium alginate (AL-Na) is derived from seaweed and has demonstrated muco-protective and hemostatic effects on upper gastrointestinal ulcers. In the present study, we evaluated the effects of AL-Na on methotrexate-induced small intestinal mucositis in rats. Animals were subcutaneously administered methotrexate at a dosage of 2.5 mg/kg once daily for 3 d. Rats were treated with single oral doses of AL-Na 30 min before and 6 h after methotrexate administration. On the 4th day, small intestines were removed and weighed. Subsequently, tissues were stained with hematoxylin-eosin and bromodeoxyuridine. AL-Na significantly prevented methotrexate-induced small intestinal mucositis. Moreover, AL-Na prevented decreases in red blood cell numbers, hemoglobin levels, and hematocrit levels. These results suggest the potential of AL-Na as a therapy for methotrexate-induced small intestinal mucositis.

  16. Oral mucositis in children suffering from acute lymphoblastic leukaemia

    PubMed Central

    2012-01-01

    Aim of the study Oral mucositis is the most commonly reported side effect observed in neoplastic patients treated with chemotherapy and radiotherapy of the head and neck region as well as in patients who have received a haematopoietic stem cell transplant. The aim of the study was to assess the oral mucosa status in children with acute lymphoblastic leukaemia (ALL) during antineoplastic therapy. Material and methods The clinical examination included 78 children aged 2-18 with ALL. The clinical examination was conducted using the dental preset tray. The condition of the oral mucosa was determined using the WHO scale for oral mucositis. Results In the first period of antineoplastic therapy the pathological lesions of the oral mucosa of the mucositis type were observed among the examined patients. The lesions had various levels of intensity. Pain was found to be the primary symptom of oral mucositis. In this study the following were observed: local erythema of the oral mucosa in 35%, white pseudomembranous lesions in 18%, erosions in 40% and oral ulcerative lesions in 4% of patients who underwent the antineoplastic therapy. Oral mucositis was observed in 3.17% of children after 6 months of chemotherapy. Conclusion Local treatment of oral mucositis with polyantibiotic-antifungal mixture, supporting antifungal systemic treatment, and improving the overall peripheral blood conditions in children suffering from acute lymphoblastic leukaemia improve the condition of the oral mucosa. PMID:23788849

  17. Hypersensitivity to acid is associated with impaired esophageal mucosal integrity in patients with gastroesophageal reflux disease with and without esophagitis.

    PubMed

    Weijenborg, Pim W; Smout, André J P M; Verseijden, Caroline; van Veen, Henk A; Verheij, Joanne; de Jonge, Wouter J; Bredenoord, Albert J

    2014-08-01

    Increased esophageal sensitivity and impaired mucosal integrity have both been described in patients with gastroesophageal reflux disease, but the relationship between hypersensitivity and mucosal integrity is unclear. The aim of the present study was to investigate acid sensitivity in patients with erosive and nonerosive reflux disease and control subjects to determine the relation with functional esophageal mucosal integrity changes as well as to investigate cellular mechanisms of impaired mucosal integrity in these patients. In this prospective experimental study, 12 patients with nonerosive reflux disease, 12 patients with esophagitis grade A or B, and 11 healthy control subjects underwent an acid perfusion test and upper endoscopy. Mucosal integrity was measured during endoscopy by electrical tissue impedance spectroscopy and biopsy specimens were analyzed in Ussing chambers for transepithelial electrical resistance, transepithelial permeability and gene expression of tight junction proteins and filaggrin. Patients with nonerosive reflux disease and esophagitis were more sensitive to acid perfusion compared with control subjects, having a shorter time to perception of heartburn and higher perceived intensity of heartburn. In reflux patients, enhanced acid sensitivity was associated with impairment of in vivo and vitro esophageal mucosal integrity. Mucosal integrity was significantly impaired in patients with esophagitis, displaying higher transepithelial permeability and lower extracellular impedance. Although no significant differences in the expression of tight junction proteins were found in biopsies among patient groups, mucosal integrity parameters in reflux patients correlated negatively with the expression of filaggrin. In conclusion, sensitivity to acid is enhanced in patients with gastroesophageal reflux disease, irrespective of the presence of erosions, and is associated with impaired esophageal mucosal integrity. Mucosal integrity of the esophagus

  18. 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).

  19. 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.

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

    PubMed

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

    2016-02-01

    The objective of this study was to observe the change in blood perfusion of liver cancer following argon-helium knife treatment with functional computer tomography perfusion imaging. Twenty-seven patients with primary liver cancer treated with argon-helium knife and were included in this study. Plain computer tomography (CT) and computer tomography perfusion (CTP) imaging were conducted in all patients before and after treatment. Perfusion parameters including blood flows, blood volume, hepatic artery perfusion fraction, hepatic artery perfusion, and hepatic portal venous perfusion were used for evaluating therapeutic effect. All parameters in liver cancer were significantly decreased after argon-helium knife treatment (p < 0.05 to all). Significant decrease in hepatic artery perfusion was also observed in pericancerous liver tissue, but other parameters kept constant. CT perfusion imaging is able to detect decrease in blood perfusion of liver cancer post-argon-helium knife therapy. Therefore, CTP imaging would play an important role for liver cancer management followed argon-helium knife therapy.

  1. Mathematical Modelling of a Brain Tumour Initiation and Early Development: A Coupled Model of Glioblastoma Growth, Pre-Existing Vessel Co-Option, Angiogenesis and Blood Perfusion

    PubMed Central

    Cai, Yan; Wu, Jie; Li, Zhiyong; Long, Quan

    2016-01-01

    We propose a coupled mathematical modelling system to investigate glioblastoma growth in response to dynamic changes in chemical and haemodynamic microenvironments caused by pre-existing vessel co-option, remodelling, collapse and angiogenesis. A typical tree-like architecture network with different orders for vessel diameter is designed to model pre-existing vasculature in host tissue. The chemical substances including oxygen, vascular endothelial growth factor, extra-cellular matrix and matrix degradation enzymes are calculated based on the haemodynamic environment which is obtained by coupled modelling of intravascular blood flow with interstitial fluid flow. The haemodynamic changes, including vessel diameter and permeability, are introduced to reflect a series of pathological characteristics of abnormal tumour vessels including vessel dilation, leakage, angiogenesis, regression and collapse. Migrating cells are included as a new phenotype to describe the migration behaviour of malignant tumour cells. The simulation focuses on the avascular phase of tumour development and stops at an early phase of angiogenesis. The model is able to demonstrate the main features of glioblastoma growth in this phase such as the formation of pseudopalisades, cell migration along the host vessels, the pre-existing vasculature co-option, angiogenesis and remodelling. The model also enables us to examine the influence of initial conditions and local environment on the early phase of glioblastoma growth. PMID:26934465

  2. Mathematical Modelling of a Brain Tumour Initiation and Early Development: A Coupled Model of Glioblastoma Growth, Pre-Existing Vessel Co-Option, Angiogenesis and Blood Perfusion.

    PubMed

    Cai, Yan; Wu, Jie; Li, Zhiyong; Long, Quan

    2016-01-01

    We propose a coupled mathematical modelling system to investigate glioblastoma growth in response to dynamic changes in chemical and haemodynamic microenvironments caused by pre-existing vessel co-option, remodelling, collapse and angiogenesis. A typical tree-like architecture network with different orders for vessel diameter is designed to model pre-existing vasculature in host tissue. The chemical substances including oxygen, vascular endothelial growth factor, extra-cellular matrix and matrix degradation enzymes are calculated based on the haemodynamic environment which is obtained by coupled modelling of intravascular blood flow with interstitial fluid flow. The haemodynamic changes, including vessel diameter and permeability, are introduced to reflect a series of pathological characteristics of abnormal tumour vessels including vessel dilation, leakage, angiogenesis, regression and collapse. Migrating cells are included as a new phenotype to describe the migration behaviour of malignant tumour cells. The simulation focuses on the avascular phase of tumour development and stops at an early phase of angiogenesis. The model is able to demonstrate the main features of glioblastoma growth in this phase such as the formation of pseudopalisades, cell migration along the host vessels, the pre-existing vasculature co-option, angiogenesis and remodelling. The model also enables us to examine the influence of initial conditions and local environment on the early phase of glioblastoma growth.

  3. Quantitative myocardial perfusion SPECT.

    PubMed

    Tsui, B M; Frey, E C; LaCroix, K J; Lalush, D S; McCartney, W H; King, M A; Gullberg, G T

    1998-01-01

    In recent years, there has been much interest in the clinical application of attenuation compensation to myocardial perfusion single photon emission computed tomography (SPECT) with the promise that accurate quantitative images can be obtained to improve clinical diagnoses. The different attenuation compensation methods that are available create confusion and some misconceptions. Also, attenuation-compensated images reveal other image-degrading effects including collimator-detector blurring and scatter that are not apparent in uncompensated images. This article presents basic concepts of the major factors that degrade the quality and quantitative accuracy of myocardial perfusion SPECT images, and includes a discussion of the various image reconstruction and compensation methods and misconceptions and pitfalls in implementation. The differences between the various compensation methods and their performance are demonstrated. Particular emphasis is directed to an approach that promises to provide quantitative myocardial perfusion SPECT images by accurately compensating for the 3-dimensional (3-D) attenuation, collimator-detector response, and scatter effects. With advances in the computer hardware and optimized implementation techniques, quantitatively accurate and high-quality myocardial perfusion SPECT images can be obtained in clinically acceptable processing time. Examples from simulation, phantom, and patient studies are used to demonstrate the various aspects of the investigation. We conclude that quantitative myocardial perfusion SPECT, which holds great promise to improve clinical diagnosis, is an achievable goal in the near future.

  4. Luxury perfusion phenomenon in acute herpes simplex virus encephalitis.

    PubMed

    Tanaka, M; Uesugi, M; Igeta, Y; Kondo, S; Sun, X; Hirai, S

    1995-02-01

    In a patient with acute herpes simplex virus (HSV) encephalitis, positron emission tomography (PET) demonstrated increased cerebral blood flow in the affected temporal lobe accompanied by reduction in the cerebral oxygen extraction fraction and the cerebral metabolic rate of oxygen, i.e., luxury perfusion. Follow-up PET studies showed reduction in cerebral perfusion until it was more closely coupled with oxygen metabolism after the resolution of the acute inflammation. These findings support previous single photon emission computed tomographic data and provide a pathophysiological background for the occurrence of hyperperfusion in HSV encephalitis. This is an interesting example of the luxury perfusion phenomenon occurring in a disease other than cerebral ischemia.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. Assessment of lung tumor response by perfusion CT.

    PubMed

    Coche, E

    2013-01-01

    Perfusion CT permits evaluation of lung cancer angiogenesis and response to therapy by demonstrating alterations in lung tumor vascularity. It is advocated that perfusion CT performed shortly after initiating therapy may provide a better evaluation of physiological changes rather than the conventional size assessment obtained with RECIST. The radiation dose,the volume of contrast medium delivered to the patient and the reproducibility of blood flow parameters remain an issue for this type of investigation.

  10. 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

  11. [Portable peristaltic perfusion pumps].

    PubMed

    Magallón Pedrera, I; Soto Torres, I

    1999-11-01

    Portable peristaltic perfusion pumps allow one to administer pharmaceuticals in hospitals as well as in primary health care centers and furthermore these pumps present multiple advantages for patients and their families since they make it possible to carry out treatment in a patient's home while at the same time lowering the costs involved. The authors analyze the most out standing aspects of portable peristaltic perfusion pumps along with their characteristics, installation, programming, and how to turn them on; in addition, the authors list the maintenance care which these pumps require.

  12. Gastroduodenal Mucosal Defense Mechanisms

    PubMed Central

    Said, Hyder; Kaji, Izumi; Kaunitz, Jonathan D.

    2015-01-01

    Purpose of Review To highlight recent developments in the field of gastroduodenal mucosal defense with emphasis on lumen-gut interactions. Recent Findings There has been a growing interest in the physiological functions of luminal chemosensors present from tongue to colon that detect organic molecules in the luminal content associated with nutrient ingestion, usually associated with specialized cells, in particular the enteroendocrine cells. These receptors transduce the release of peptide hormones, in particular proglucagon-derived products such as the glucagon-like-peptides (GLPs), which have profound effects on gut function and on metabolism. Luminal chemosensors transduce GLP release in response to changes in the cellular environment, as part of the mechanism of nutrient chemosensing. GLP-2 has important trophic effects on the intestinal mucosa, including increasing the proliferation rate of stem cells and reducing transmucosal permeability to ions and small molecules, in addition to increasing the rate of duodenal bicarbonate secretion. GLP-1, although traditionally considered an incretin that enhances the effect of insulin on peripheral tissues, also has trophic effects on the intestinal epithelium. Summary A better understanding of the mechanisms that mediate GLP release can further illuminate the importance of nutrient chemosensing as an important component of the mechanism that mediates the trophic effects of luminal nutrients. GLP-1 and -2 are already in clinical use for the treatment of diabetes and intestinal failure. Improved understanding of the control of their release and their end-organ effects will identify new clinical indications and interventions that enhance their release. PMID:26376476

  13. 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.

  14. Perfusion and diffusion limitations in middle ear gas exchange: the exchange of CO2 as a test case.

    PubMed

    Marcusohn, Yael; Ar, Amos; Dirckx, Joris J J

    2010-06-14

    A long standing debate on perfusion/diffusion limitations in the context of middle ear (ME) gas exchange was revisited using data obtained from previous iso-pressure gas-exchange measurements in different mammals. We tried to determine whether the exchange of CO(2) in the ME is limited by perfusion or by diffusion by comparing the mass specific cardiac output (msQ) and the mass specific initial CO(2) flow rate into air-washed MEs (msV(i) CO(2)) of rabbits and rats. Based on previously published allometry at rest, the msQ was 0.154 mL/(min g) in rabbits (mean body weight: 2800 g) and 0.259 mL/(min g) in rats (mean body weight: 179.1 g); msV(i) CO(2) (Delta t=0) was 0.109+/-0.047 microL/(h g) in rabbits (n=16) and 0.170+/-0.094 microL/(h g) in rats (n=9). Similar ratios were found when an allometric comparison was made between the ratio of msV(i) CO(2) (Delta t=0) (approximately 0.64), and the ratio of msQs (approximately 0.59) in rabbits and rats. If the active mucosal surface areas of MEs of rabbits and rats are directly proportional to their masses as are the masses of their hearts and if their msQs are proportional to the rates of blood flows in the ME mucosa, these results support the assumption that the exchange of CO(2) in the ME of mammals is mainly perfusion (and not diffusion) dependent.

  15. Coupling between resting cerebral perfusion and EEG.

    PubMed

    O'Gorman, R L; Poil, S-S; Brandeis, D; Klaver, P; Bollmann, S; Ghisleni, C; Lüchinger, R; Martin, E; Shankaranarayanan, A; Alsop, D C; Michels, L

    2013-07-01

    While several studies have investigated interactions between the electroencephalography (EEG) and functional magnetic resonance imaging BOLD signal fluctuations, less is known about the associations between EEG oscillations and baseline brain haemodynamics, and few studies have examined the link between EEG power outside the alpha band and baseline perfusion. Here we compare whole-brain arterial spin labelling perfusion MRI and EEG in a group of healthy adults (n = 16, ten females, median age: 27 years, range 21-48) during an eyes closed rest condition. Correlations emerged between perfusion and global average EEG power in low (delta: 2-4 Hz and theta: 4-7 Hz), middle (alpha: 8-13 Hz), and high (beta: 13-30 Hz and gamma: 30-45 Hz) frequency bands in both cortical and sub-cortical regions. The correlations were predominately positive in middle and high-frequency bands, and negative in delta. In addition, central alpha frequency positively correlated with perfusion in a network of brain regions associated with the modulation of attention and preparedness for external input, and central theta frequency correlated negatively with a widespread network of cortical regions. These results indicate that the coupling between average EEG power/frequency and local cerebral blood flow varies in a frequency specific manner. Our results are consistent with longstanding concepts that decreasing EEG frequencies which in general map onto decreasing levels of activation.

  16. A reappraisal of retrograde cerebral perfusion

    PubMed Central

    2013-01-01

    Brain protection during aortic arch surgery by perfusing cold oxygenated blood into the superior vena cava was first reported by Lemole et al. In 1990 Ueda and associates first described the routine use of continuous retrograde cerebral perfusion (RCP) in thoracic aortic surgery for the purpose of cerebral protection during the interval of obligatory interruption of anterograde cerebral flow. The beneficial effects of RCP may be its ability to sustain brain hypothermia during hypothermic circulatory arrest (HCA) and removal of embolic material from the arterial circulation of the brain. RCP can offer effective brain protection during HCA for about 40 to 60 minutes. Animal experiments revealed that RCP provided inadequate cerebral perfusion and that neurological recovery was improved with selective antegrade cerebral perfusion (ACP), however, both RCP and ACP provide comparable clinical outcomes regarding both the mortality and stroke rates by risk-adjusted and case-matched comparative study. RCP still remains a valuable adjunct for brain protection during aortic arch repair in particular pathologies and patients. PMID:23977600

  17. Blood

    MedlinePlus

    ... increased red blood cell destruction can affect teens: G6PD deficiency. G6PD is an enzyme that helps to protect ... can cause red cells to hemolyze, or burst. G6PD deficiency is a common hereditary disease among people of ...

  18. Lesion area detection using source image correlation coefficient for CT perfusion imaging.

    PubMed

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

    2013-09-01

    Computer tomography (CT) perfusion imaging is widely used to calculate brain hemodynamic quantities such as cerebral blood flow, cerebral blood volume, and mean transit time that aid the diagnosis of acute stroke. Since perfusion source images contain more information than hemodynamic maps, good utilization of the source images can lead to better understanding than the hemodynamic maps alone. Correlation-coefficient tests are used in our approach to measure the similarity between healthy tissue time-concentration curves and unknown curves. This information is then used to differentiate penumbra and dead tissues from healthy tissues. The goal of the segmentation is to fully utilize information in the perfusion source images. Our method directly identifies suspected abnormal areas from perfusion source images and then delivers a suggested segmentation of healthy, penumbra, and dead tissue. This approach is designed to handle CT perfusion images, but it can also be used to detect lesion areas in magnetic resonance perfusion images.

  19. Vitamin D and mucosal immune function

    PubMed Central

    Sun, Jun

    2010-01-01

    Purpose of review Significant advances have been made in the characterization of Vitamin D and the Vitamin D receptor (VDR) in immune function. The studies of signaling pathways involved in the response to infection and inflammation have led to a more detailed understanding of the cellular response to Vitamin D through VDR. This review summarizes recent progress in understanding how Vitamin D contributes to mucosal immune function, particularly in relation to the molecular mechanisms by which Vitamin D and VDR influence mucosal immunity, bacterial infection, and inflammation. Recent findings Recently, it was shown that Vitamin D modulates the T cell antigen receptor, further demonstrating that Vitamin D has a nonclassical role in immunoregulation. The anti-inflammation and anti-infection functions for Vitamin D are newly identified and highly significant activities. Vitamin D/VDR have multiple critical functions in regulating the response to intestinal homeostasis, tight junctions, pathogen invasion, commensal bacterial colonization, antimicrobe peptide secretion, and mucosal defense. Interestingly, microorganisms modulate the VDR signaling pathway. Summary Vitamin D is known as a key player in calcium homeostasis and electrolyte and blood pressure regulation. Recently, important progress has been made in understanding how the noncanonical activities of Vitamin D influence the pathogenesis and prevention of human disease. Vitamin D and VDR are directly involved in T cell antigen receptor signaling. The involvement of Vitamin D/VDR in anti-inflammation and anti-infection represents a newly identified and highly significant activity for VDR. Studies have indicated that the dysregulation of VDR may lead to exaggerated inflammatory responses, raising the possibility that defects in Vitamin D and VDR signaling transduction may be linked to bacterial infection and chronic inflammation. Further characterization of Vitamin D/VDR will help elucidate the pathogenesis of

  20. Biology of HIV Mucosal Transmission

    PubMed Central

    Wu, Li

    2008-01-01

    Purpose of review HIV-1 mucosal transmission plays a critical role in HIV-1 infection and AIDS pathogenesis. This review summarizes the latest advances in biological studies of HIV-1 mucosal transmission, highlighting the implications of these studies in the development of microbicides to prevent HIV-1 transmission. Recent findings New studies of initial HIV-1 infection using improved culture models updated the current view of mucosal transmission. Mechanistic studies enhanced our understanding of cell-cell transmission of HIV-1 mediated by the major target cells, including dendritic cells, CD4+ T cells, and macrophages. Increasing evidence indicated the significance of host factors and immune responses in HIV-1 mucosal infection and transmission. Summary Recent progress in HIV-1 mucosal infection and transmission enriches our knowledge of virus-host interactions and viral pathogenesis. Functional studies of HIV-1 interactions with host cells can provide new insights into the design of more effective approaches to combat HIV-1 infection and AIDS. PMID:18802490

  1. 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

  2. Mucosal immunoglobulins at respiratory surfaces mark an ancient association that predates the emergence of tetrapods.

    PubMed

    Xu, Zhen; Takizawa, Fumio; Parra, David; Gómez, Daniela; von Gersdorff Jørgensen, Louise; LaPatra, Scott E; Sunyer, J Oriol

    2016-02-12

    Gas-exchange structures are critical for acquiring oxygen, but they also represent portals for pathogen entry. Local mucosal immunoglobulin responses against pathogens in specialized respiratory organs have only been described in tetrapods. Since fish gills are considered a mucosal surface, we hypothesized that a dedicated mucosal immunoglobulin response would be generated within its mucosa on microbial exposure. Supporting this hypothesis, here we demonstrate that following pathogen exposure, IgT(+) B cells proliferate and generate pathogen-specific IgT within the gills of fish, thus providing the first example of locally induced immunoglobulin in the mucosa of a cold-blooded species. Moreover, we demonstrate that gill microbiota is predominantly coated with IgT, thus providing previously unappreciated evidence that the microbiota present at a respiratory surface of a vertebrate is recognized by a mucosal immunoglobulin. Our findings indicate that respiratory surfaces and mucosal immunoglobulins are part of an ancient association that predates the emergence of tetrapods.

  3. Quantitative measurement of tissue perfusion and diffusion in vivo.

    PubMed

    Chenevert, T L; Pipe, J G; Williams, D M; Brunberg, J A

    1991-01-01

    Magnetic resonance imaging techniques designed for sensitivity to microscopic motions of water diffusion and blood flow in the capillary network are also exceptionally sensitive to bulk motion properties of the tissue, which may lead to contrast artifact and large quantitative errors. The magnitude of bulk motion error that exists in human brain perfusion/diffusion imaging and the inability of cardiac gating to adequately control this motion are demonstrated by direct measurement of phase stability of voxels localized in the brain. Two methods are introduced to reduce bulk motion phase error. The first, a postprocessing phase correction algorithm, reduces coarse phase error but is inadequate by itself for quantitative perfusion/diffusion MRI. The second method employs orthogonal slice selection gradients to define a column of tissue in the object, from which echoes may be combined in a phase-insensitive manner to measure more reliably the targeted signal attenuation. Applying this acquisition technique and a simplistic model of perfusion and diffusion signal attenuations yields an estimated perfusion fraction of 3.4 +/- 1.1% and diffusion coefficient of 1.1 +/- 0.2 x 10(-5) cm2/s in the white matter of one normal volunteer. Successful separation of perfusion and diffusion effects by this technique is supported in a dynamic study of calf muscle. Periods of normal blood flow, low flow, and reactive hyperemia are clearly distinguished in the quantitative perfusion results, whereas measured diffusion remained nearly constant.

  4. Pulmonary artery perfusion versus no pulmonary perfusion during cardiopulmonary bypass in patients with COPD: a randomised clinical trial

    PubMed Central

    Buggeskov, Katrine B; Sundskard, Martin M; Jonassen, Thomas; Andersen, Lars W; Secher, Niels H; Ravn, Hanne B; Steinbrüchel, Daniel A; Jakobsen, Janus C; Wetterslev, Jørn

    2016-01-01

    Introduction Absence of pulmonary perfusion during cardiopulmonary bypass (CPB) may be associated with reduced postoperative oxygenation. Effects of active pulmonary artery perfusion were explored in patients with chronic obstructive pulmonary disease (COPD) undergoing cardiac surgery. Methods 90 patients were randomised to receive pulmonary artery perfusion during CPB with either oxygenated blood (n=30) or histidine-tryptophan-ketoglutarate (HTK) solution (n=29) compared with no pulmonary perfusion (n=31). The coprimary outcomes were the inverse oxygenation index compared at 21 hours after starting CPB and longitudinally in a mixed-effects model (MEM). Secondary outcomes were tracheal intubation time, serious adverse events, mortality, days alive outside the intensive care unit (ICU) and outside the hospital. Results 21 hours after starting CPB patients receiving pulmonary artery perfusion with normothermic oxygenated blood had a higher oxygenation index compared with no pulmonary perfusion (mean difference (MD) 0.94; 95% CI 0.05 to 1.83; p=0.04). The blood group had also a higher oxygenation index both longitudinally (MEM, p=0.009) and at 21 hours (MD 0.99; CI 0.29 to 1.69; p=0.007) compared with the HTK group. The latest result corresponds to a difference in the arterial partial pressure of oxygen of 23 mm Hg with a median fraction of inspired oxygen of 0.32. Yet the blood or HTK groups did not demonstrate a longitudinally higher oxygenation index compared with no pulmonary perfusion (MEM, p=0.57 and 0.17). Similarly, at 21 hours there was no difference in the oxygenation index between the HTK group and those no pulmonary perfusion (MD 0.06; 95% CI −0.73 to 0.86; p=0.87). There were no statistical significant differences between the groups for the secondary outcomes. Discussion Pulmonary artery perfusion with normothermic oxygenated blood during cardiopulmonary bypass appears to improve postoperative oxygenation in patients with COPD undergoing

  5. 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.

  6. The Therapeutic Effect of PLAG against Oral Mucositis in Hamster and Mouse Model

    PubMed Central

    Lee, Ha-Reum; Yoo, Nina; Kim, Joo Heon; Sohn, Ki-Young; Kim, Heung-Jae; Kim, Myung-Hwan; Han, Mi Young; Yoon, Sun Young; Kim, Jae Wha

    2016-01-01

    Chemotherapy-induced mucositis can limit the effectiveness of cancer therapy and increase the risk of infections. However, no specific therapy for protection against mucositis is currently available. In this study, we investigated the therapeutic effect of PLAG (1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol, acetylated diglyceride) in 5-fluorouracil (5-FU)-induced oral mucositis animal models. Hamsters were administered 5-FU (80 mg/kg) intraperitoneally on days 0, 6, and 9. The animals’ cheek pouches were then scratched equally with the tip of an 18-gage needle on days 1, 2, and 7. PLAG was administered daily at 250 mg/kg/day. PLAG administration significantly reduced 5-FU/scratching-induced mucositis. Dramatic reversal of weight loss in PLAG-treated hamsters with mucositis was observed. Histochemical staining data also revealed newly differentiated epidermis and blood vessels in the cheek pouches of PLAG-treated hamsters, indicative of recovery. Whole blood analyses indicated that PLAG prevents 5-FU-induced excessive neutrophil transmigration to the infection site and eventually stabilizes the number of circulating neutrophils. In a mouse mucositis model, mice with 5-FU-induced disease treated with PLAG exhibited resistance to body-weight loss compared with mice that received 5-FU or 5-FU/scratching alone. PLAG also dramatically reversed mucositis-associated weight loss and inhibited mucositis-induced inflammatory responses in the tongue and serum. These data suggest that PLAG enhances recovery from 5-FU-induced oral mucositis and may therefore be a useful therapeutic agent for treating side effects of chemotherapy, such as mucositis and cachexia. PMID:27800302

  7. USE OF A PROGRAMMABLE CALCULATOR IN CARDIOPULMONARY PERFUSION.

    PubMed

    Mills, J David; Tallent, Jerome H.

    1978-06-01

    This study describes a hand-held, battery-powered, programmable instrument (Calculator Model SR-52) that can be taken directly into the operating room by cardiopulmonary perfusionists. Three programs are described in detail: 1) Cardiopulmonary perfusion parameters and estimated blood volume; 2) blood gas parameters and saturations, with temperature corrections; and 3) cardiopulmonary oxygen transfer and oxygenator efficiency. This inexpensive calculator allows perfusion personnel to manipulate easily-derived data into values which heretofore have required elaborate nomograms or special slide rules-or were not available within a reasonable computational time.

  8. Imaging of drug effects in perfused liver

    NASA Astrophysics Data System (ADS)

    Dammann, Marc; Mahlke, Christine; Kessler, Manfred D.

    2002-06-01

    Various medications affect the systemic circulation and organ oxygenation causing dilatation or constriction of blood vessels. Imminent liver failure can be generated by reduced perfusion of different origins. In this case hepatic vasodilatation would be a therapeutical approach for improving patient's condition. Our examinations have been performed in perfused rat liver using spectrometric methods. Two defined areas of the liver were measured punctually. We compared the influence of Tetramethylpyrazine and Glyceroltrinitrate on hemoglobin oxygenation (HbO2) and concentration (Hb-conc.) in rat liver after application of Norepinephrine, which caused a mid decrease in hemoglobin oxygenation of 47,9 %. Both increased the HbO2, but differed from each other in manner of time and extent. Tetramethylpyrazine indicated a longer effect than Glyceroltrinitrate. Furthermore, HbO2 and Hb-conc. showed a conversed relation. From the shape of the absorption spectra it is possible to derive the oxygenation of hemoglobin.

  9. Effect of cardiac dysrhythmia on cerebral perfusion.

    PubMed

    Sand, B J; Rose, H B; Barker, W F

    1976-07-01

    Extracranial carotid arterial obstructive disease has been the entity most commonly associated with transient cerebrovascular insufficiency. A nonobstructive, frequently overlooked cause of cerebral ischemia is cardiac dysrhythmia. We have explored this by observations of experimental animals and of man. Blood flow and pressure in the carotid arteries of dogs were shown to be decreased by mechnically induced premature ventricular contractions. The significance of the cardiogenic contribution to altered cerebrovascular perfusion was studied by ocular and brachial plethysmography in 210 patients suspected by history of having carotid arterial insufficiency. Of the 210 patients, 62 demonstrated abnormal ocular plethysmographic recordings, and of those, nine had dysrhythmias associated with significant deficits of ocular perfusion. Five patients whose recordings were technically suitable for publication are presented to demonstrate the bizarre ocular plethysmographic recordings seen during the dysrhythmic cycle.

  10. The human milk oligosaccharide 2′-fucosyllactose attenuates the severity of experimental necrotising enterocolitis by enhancing mesenteric perfusion in the neonatal intestine

    PubMed Central

    Good, Misty; Sodhi, Chhinder P.; Yamaguchi, Yukihiro; Jia, Hongpeng; Lu, Peng; Fulton, William B.; Martin, Laura Y.; Prindle, Thomas; Nino, Diego F.; Zhou, Qinjie; Ma, Congrong; Ozolek, John A.; Buck, Rachael H.; Goehring, Karen C.; Hackam, David J.

    2016-01-01

    Necrotising enterocolitis (NEC) is a common disease in premature infants characterised by intestinal ischaemia and necrosis. The only effective preventative strategy against NEC is the administration of breast milk, although the protective mechanisms remain unknown. We hypothesise that an abundant human milk oligosaccharide (HMO) in breast milk, 2′-fucosyllactose (2′FL), protects against NEC by enhancing intestinal mucosal blood flow, and we sought to determine the mechanisms underlying this protection. Administration of HMO-2′FL protected against NEC in neonatal wild-type mice, resulted in a decrease in pro-inflammatory markers and preserved the small intestinal mucosal architecture. These protective effects occurred via restoration of intestinal perfusion through up-regulation of the vasodilatory molecule endothelial nitric oxide synthase (eNOS), as administration of HMO-2′FL to eNOS-deficient mice or to mice that received eNOS inhibitors did not protect against NEC, and by 16S analysis HMO-2′FL affected the microbiota of the neonatal mouse gut, although these changes do not seem to be the primary mechanism of protection. Induction of eNOS by HMO-2′FL was also observed in cultured endothelial cells, providing a link between eNOS and HMO in the endothelium. These data demonstrate that HMO-2′FL protects against NEC in part through maintaining mesenteric perfusion via increased eNOS expression, and suggest that the 2′FL found in human milk may be mediating some of the protective benefits of breast milk in the clinical setting against NEC. PMID:27609061

  11. 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.

  12. 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

  13. 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

  14. 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

  15. 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.

  16. 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

  17. Cyclo-oxygenase isozymes in mucosal ulcerogenic and functional responses following barrier disruption in rat stomachs

    PubMed Central

    Hirata, Takuya; Ukawa, Hideki; Yamakuni, Hisashi; Kato, Shinichi; Takeuchi, Koji

    1997-01-01

    We examined the effects of selective and nonselective cyclo-oxygenase (COX) inhibitors on various functional changes in the rat stomach induced by topical application of taurocholate (TC) and investigated the preferential role of COX isozymes in these responses. Rat stomachs mounted in ex vivo chambers were perfused with 50 mM HCl and transmucosal potential difference (p.d.), mucosal blood flow (GMBF), luminal acid loss and luminal levels of prostaglandin E2 (PGE2) were measured before, during and after exposure to 20 mM TC. Mucosal application of TC in control rats caused a reduction in p.d., followed by an increase of luminal acid loss and GMBF, and produced only minimal damage in the mucosa 2 h later. Pretreatment with indomethacin (10 mg kg−1, s.c.), a nonselective COX-1 and COX-2 inhibitor, attenuated the gastric hyperaemic response caused by TC without affecting p.d. and acid loss, resulting in haemorrhagic lesions in the mucosa. In contrast, selective COX-2 inhibitors, such as NS-398 and nimesulide (10 mg kg−1, s.c.), had no effect on any of the responses induced by TC and did not cause gross damage in the mucosa. Luminal PGE2 levels were markedly increased during and after exposure to TC and this response was significantly inhibited by indomethacin but not by either NS-398 or nimesulide. The expression of COX-1-mRNA was consistently detected in the gastric mucosa before and after TC treatment, while a faint expression of COX-2-mRNA was detected only 2 h after TC treatment. Both NS-398 and nimesulide significantly suppressed carrageenan-induced rat paw oedema, similar to indomethacin. These results confirmed a mediator role for prostaglandins in the gastric hyperaemic response following TC-induced barrier disruption, and suggest that COX-1 but not COX-2 is a key enzyme in maintaining ‘housekeeping' functions in the gastric mucosa under both normal and adverse conditions. PMID:9351500

  18. Time course of a new ultrashort-acting beta-adrenoceptor-blocking drug, ONO-1101: comparison with those of esmolol and propranolol by using the canine isolated, blood-perfused heart preparations.

    PubMed

    Motomura, S; Hagihara, A; Narumi, Y; Hashimoto, K

    1998-03-01

    Time courses of beta-adrenoceptor-blocking actions of ONO-1101, a new cardioselective beta-blocker, were compared with those of esmolol and propranolol by using the isolated, blood-perfused sinoatrial node (SAN) and papillary muscle (PM) preparations of dogs. ONO-1101 per se given intraarterially (i.a.) in each nutrient artery did not affect basal sinoatrial rates (SARs; 99 +/- 2 beats/min, n = 7) in the SAN and developed tension (DT; 3.2 +/- 0.7 g, n = 7) of the PM preparations. Norepinephrine (NE) injected i.a. into the each artery induced increases in SAR (42 +/- 6 beats/min at 0.051 +/- 0.014 microg) and PMDT (2.9 +/- 0.4 g at 0.048 +/- 0.011 microg). The i.a. injections of NE were repeated every 3 min after i.v. bolus injections of ONO- 1101 into the support dog. NE-induced increases in SAR and PMDT were maximally inhibited 3 to 6 min after the i.v. injections of ONO-1101. Maximal percentage inhibitions by ONO-1101 of NE-induced increases in SAR were 54 +/- 6, 78 +/- 3, and 96 +/- 2% at 0.01, 0.1, and 1 mg/kg of the drug, respectively. Similarly, maximal percentage inhibitions by ONO-1101 of NE-induced increases in PMDT were 50 +/- 12, 93 +/- 2, and 100% +/- 0, respectively. The inhibition was quickly recovered; times required for 50% recovery (RT1/2) were 12 +/- 3. 17 +/- 3, and 32 +/- 10 min in the SAN preparation, and 13 +/- 3, 16 +/- 2, and 39 +/- 11 min in the PM preparations, after i.v. injections of 0.01, 0.1, and 1 mg/kg of ONO-1101, respectively. In comparison, maximal percentage inhibitions by esmolol of NE-induced increases in SAR were 45 +/- 5, 79 +/- 6, and 96 +/- 2%, and those in PMDT were 34 +/- 4, 75 +/- 5, and 97 +/- 1%, whereas the RT1/2 values were 11 +/- 2, 15 +/- 4, and 40 +/- 12 min in the SAN preparation, and 10 +/- 2, 16 +/- 7, and 27 +/- 6 min in the PM preparations, after i.v. injections of 0.01, 0.1, and 1 mg/kg of esmolol, respectively. In contrast, the maximal percentage inhibitions by an i.v. bolus injection of 0.1 mg/kg of

  19. 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

  20. Intrahemispheric Perfusion in Chronic Stroke-Induced Aphasia

    PubMed Central

    Walenski, Matthew; Chen, YuFen; Caplan, David; Rapp, Brenda; Grunewald, Kristin; Nunez, Mia; Zinbarg, Richard; Parrish, Todd B.

    2017-01-01

    Stroke-induced alterations in cerebral blood flow (perfusion) may contribute to functional language impairments and recovery in chronic aphasia. Using MRI, we examined perfusion in the right and left hemispheres of 35 aphasic and 16 healthy control participants. Across 76 regions (38 per hemisphere), no significant between-subjects differences were found in the left, whereas blood flow in the right was increased in the aphasic compared to the control participants. Region-of-interest (ROI) analyses showed a varied pattern of hypo- and hyperperfused regions across hemispheres in the aphasic participants; however, there were no significant correlations between perfusion values and language abilities in these regions. These patterns may reflect autoregulatory changes in blood flow following stroke and/or increases in general cognitive effort, rather than maladaptive language processing. We also examined blood flow in perilesional tissue, finding the greatest hypoperfusion close to the lesion (within 0–6 mm), with greater hypoperfusion in this region compared to more distal regions. In addition, hypoperfusion in this region was significantly correlated with language impairment. These findings underscore the need to consider cerebral perfusion as a factor contributing to language deficits in chronic aphasia as well as recovery of language function. PMID:28357141

  1. 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).

  2. Harmonic analysis of perfusion pumps.

    PubMed

    Dougherty, F Carroll; Donovan, F M; Townsley, Mary I

    2003-12-01

    The controversy over the use of nonpulsatile versus pulsatile pumps for maintenance of normal organ function during ex vivo perfusion has continued for many years, but resolution has been limited by lack of a congruent mathematical definition of pulsatility. We hypothesized that the waveform frequency and amplitude, as well as the underlying mean distending pressure are all key parameters controlling vascular function. Using discrete Fourier Analysis, our data demonstrate the complexity of the pulmonary arterial pressure waveform in vivo and the failure of commonly available perfusion pumps to mimic in vivo dynamics. In addition, our data show that the key harmonic signatures are intrinsic to the perfusion pumps, are similar for flow and pressure waveforms, and are unchanged by characteristics of the downstream perfusion circuit or perfusate viscosity.

  3. Monitoring perfusion changes in laser-treated tumors using laser doppler flowmetry

    NASA Astrophysics Data System (ADS)

    Deans, Abby; Hess, Linda; Koss, Michael; Liu, Hong; Chen, Wei R.

    2006-02-01

    Laser Doppler perfusion monitors are effect tools in understanding blood flow in many different types of biological studies. Because the low-intensity lasers used in Doppler perfusion measurements must interact with moving blood cells, the depth of probe-able tissue is limited to the volume of tissue within the hemisphere of radius ~1mm from the probe tip. In addition, heterogeneities in surface perfusion make precise probe placement very important if one is comparing successive measurements. Consequently, useful tissue perfusion measurements have been difficult to obtain, especially in deep tissues. In this study, a new method was developed for monitoring deep-tissue blood perfusion directionally with the Laserflo laser Doppler perfusion probe. The probe was inserted just under the skin superficially to a rat prostatic tumor through the shaft of a 16-gauge needle, which was modified to allow the probe to be exposed without extending beyond the beveled needle tip. Perfusion measurements of the tumor surface or the skin were made by rotating the bevel to face either inside or outside. Using this technique, tumor tissue can be differentiated from either skin or muscle. To study the responses of tumor to light stimulation, an 805nm biomedical treatment laser was used to irradiate the tumor. The perfusion of the tumor surface was shown to decrease slightly with short treatment laser applications (1W for 30 seconds or 1 minute). After a longer treatment session (5 minutes), the perfusion of the tumor tissue increased significantly. However, with an even longer (10 minutes) treatment, the perfusion of the tumor surface was shown to decrease once again. This trend indicates that before laser heating becomes significant, the perfusion decreases for as yet poorly understood reasons. When laser heating becomes significant, after the five-minute session, the perfusion increases dramatically, corresponding to the expected dilation of blood vessels during tissue heating. After

  4. Mucosal immunology of food allergy.

    PubMed

    Berin, M Cecilia; Sampson, Hugh A

    2013-05-06

    Food allergies are increasing in prevalence at a higher rate than can be explained by genetic factors, suggesting a role for as yet unidentified environmental factors. In this review, we summarize the state of knowledge about the healthy immune response to antigens in the diet and the basis of immune deviation that results in immunoglobulin E (IgE) sensitization and allergic reactivity to foods. The intestinal epithelium forms the interface between the external environment and the mucosal immune system, and emerging data suggest that the interaction between intestinal epithelial cells and mucosal dendritic cells is of particular importance in determining the outcome of immune responses to dietary antigens. Exposure to food allergens through non-oral routes, in particular through the skin, is increasingly recognized as a potentially important factor in the increasing rate of food allergy. There are many open questions on the role of environmental factors, such as dietary factors and microbiota, in the development of food allergy, but data suggest that both have an important modulatory effect on the mucosal immune system. Finally, we discuss recent developments in our understanding of immune mechanisms of clinical manifestations of food allergy. New experimental tools, particularly in the field of genomics and the microbiome, are likely to shed light on factors responsible for the growing clinical problem of food allergy.

  5. Cryopreservation of Human Mucosal Leukocytes

    PubMed 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

  6. Survey of pre-inflammation cytokines levels in radiotherapy-induced-mucositis.

    PubMed

    Seyyednejad, Farshad; Rezaee, Amirreza; Haghi, Sarvar; Goldust, Mohamad

    2012-11-15

    Mucositis is a toxic side effect of anti-cancer treatments and is a major focus in cancer research. Pro-inflammatory cytokines have previously been implicated in the pathophysiology of chemotherapy-induced mucositis. The aim of this study was to detect a correlation between serum cytokine levels in head and neck (H and N) cancer patients receiving combined chemo-radiation therapy. Thirty patients with H and N epithelial cancer were recruited to this study. All patients received radiotherapy to the H and N region with doses ranging from 50-70 Gray (Gy). Chemotherapy with cisplatin, carboplatin, 5-fluorouracil and taxanes was given to high-risk patients, using standard chemotherapy protocols. Patients were evaluated for mucositis according to WHO common toxicity criteria and blood samples were drawn for inflammatory (IL-1 and TNF-a) and before and during treatment. The mucositis evaluation demonstrated mucositis grade IV in 33.3% of the patients after the 3rd treatment week. At the end of treatment, the number of patients with grade IV mucositis was less. IL-1 and TNF-alpha did not show any correlation with PEG tube installation. The level of cytokines measured before and during therapy showed decreased TNF-alpha especially after the third week of therapy. No relationship between IL-1 and TNF-alpha, level and mucositis grade was shown.

  7. Mucosal injury induced by ischemia and reperfusion in the piglet intestine: Influences of age and feeding

    SciTech Connect

    Crissinger, K.D.; Granger, D.N. )

    1989-10-01

    The pathogenesis of neonatal necrotizing enterocolitis is unknown, but enteral alimentation, infectious agents, and mesenteric ischemia have been frequently invoked as primary initiators of the disease. To define the vulnerability of the intestinal mucosa to ischemia and reperfusion in the developing piglet, we evaluated changes in mucosal permeability using plasma-to-lumen clearance of chromium 51-labeled ethylenediaminetetraacetic acid in the ileum of anesthetized 1-day-, 3-day-, 2-wk-, and 1-mo-old piglets as a function of (a) duration of intestinal ischemia (20, 40, or 60 min of total superior mesenteric artery occlusion), (b) feeding status (fasted or nursed), and (c) composition of luminal perfusate (balanced salt solution vs. predigested cow milk-based formula). Baseline chromium 51-labeled ethylenediaminetetraacetic acid clearance was not significantly altered by ischemia, irrespective of duration, or feeding in all age groups. However, clearances were significantly elevated during reperfusion after 1 h of total intestinal ischemia in all age groups, whether fasted or fed. Reperfusion-induced increases in clearance did not differ among age groups when the bowel lumen was perfused with a balanced salt solution. However, luminal perfusion with formula resulted in higher clearances in 1-day-old piglets compared with all older animals. Thus, the neonatal intestine appears to be more vulnerable to mucosal injury induced by ischemia and reperfusion in the presence of formula than the intestine of older animals.

  8. A New Apparatus and Surgical Technique for the Dual Perfusion of Human Tumor Xenografts in Situ in Nude Rats

    PubMed Central

    Dauchy, Robert T; Dauchy, Erin M; Mao, Lulu; Belancio, Victoria P; Hill, Steven M; Blask, David E

    2012-01-01

    We present a new perfusion system and surgical technique for simultaneous perfusion of 2 tissue-isolated human cancer xenografts in nude rats by using donor blood that preserves a continuous flow. Adult, athymic nude rats (Hsd:RH-Foxn1rnu) were implanted with HeLa human cervical or HT29 colon adenocarcinomas and grown as tissue-isolated xenografts. When tumors reached an estimated weight of 5 to 6 g, rats were prepared for perfusion with donor blood and arteriovenous measurements. The surgical procedure required approximately 20 min to complete for each tumor, and tumors were perfused for a period of 150 min. Results showed that tumor venous blood flow, glucose uptake, lactic acid release, O2 uptake and CO2 production, uptake of total fatty acid and linoleic acid and conversion to the mitogen 13-HODE, cAMP levels, and activation of several marker kinases were all well within the normal physiologic, metabolic, and signaling parameters characteristic of individually perfused xenografts. This new perfusion system and technique reduced procedure time by more than 50%. These findings demonstrate that 2 human tumors can be perfused simultaneously in situ or ex vivo by using either rodent or human blood and suggest that the system may also be adapted for use in the dual perfusion of other organs. Advantages of this dual perfusion technique include decreased anesthesia time, decreased surgical manipulation, and increased efficiency, thereby potentially reducing the numbers of laboratory animals required for scientific investigations. PMID:22546915

  9. Systemic and Mucosal Differences in HIV Burden, Immune and Therapeutic Responses

    PubMed Central

    Wahl, Sharon M.; Redford, Maryann; Christensen, Shawna; Mack, Wendy; Cohn, Jon; Janoff, Edward N.; Mestecky, Jiri; Jenson, Hal B.; Navazesh, Mahvash; Cohen, Mardge; Reichelderfer, Patricia; Kovacs, Andrea

    2011-01-01

    Background Mucosal tissues represent major targets for HIV transmission, but differ in susceptibility and reservoir function by unknown mechanisms. Methods In a cross-sectional study, HIV RNA and infectious virus were compared between oral and genital compartments and blood in HIV-infected women, in association with clinical parameters, co-pathogens and putative innate and adaptive HIV inhibitors. Results HIV RNA was detectable in 24.5% of women from all 3 compartments, whereas 45% had RNA in only one or two sites. By comparison, infectious HIV, present in blood of the majority, was rare in mucosal sites. Innate mediators, SLPI and TSP, were highest in mucosae. Highly active antiretroviral therapy (HAART) was associated with an 80% decreased probability of shedding. Multivariate logistic regression models revealed that mucosal HIV RNA was associated with higher plasma RNA, infectious virus, and total mucosal IgA, but not IgG. There was a 37-fold increased probability of detecting RNA in both genital and oral specimens (P=0.008;P=0.02, respectively) among women in highest vs lowest IgA tertiles. Conclusions Mucosal sites exhibit distinct characteristics of infectious HIV, viral shedding and responses to therapy, dependent upon both systemic and local factors. Of the putative innate and adaptive mucosal defense factors examined, only IgA was associated with HIV RNA shedding. However, rather than being protective, there was a striking increase in probability of detectable HIV RNA shedding in women with highest total IgA. PMID:21239996

  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. Diffusion, Perfusion, and Histopathologic Characteristics of Desmoplastic Infantile Ganglioglioma

    PubMed Central

    Ho, Chang Y; Gener, Melissa; Bonnin, Jose; Kralik, Stephen F

    2016-01-01

    We present a case series of a rare tumor, the desmoplastic infantile ganglioglioma (DIG) with MRI diffusion and perfusion imaging quantification as well as histopathologic characterization. Four cases with pathologically-proven DIG had diffusion weighted imaging (DWI) and two of the four had dynamic susceptibility contrast imaging. All four tumors demonstrate DWI findings compatible with low-grade pediatric tumors. For the two cases with perfusion imaging, a higher relative cerebral blood volume was associated with higher proliferation index on histopathology for one of the cases. Our results are discussed in conjunction with a literature review. PMID:27761184

  12. 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.

  13. 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.

  14. Cerebral-Body Perfusion Model

    DTIC Science & Technology

    1990-07-01

    compared to the 0.5g curve) fall in flow. Fig. 9b, showing the 5g case, strongly suggests a possible, so-called, " luxury perfusion ", in which natural...as the luxury perfusion situation which bypasses the flow with the nutrients it carries (through newly opened collaterals) and result in a "blackout...89-0054 CEREBRAL-BODY PERFUSION MODEL S. Sorek’, J. Bear2, and M., Feinsod3 in Collaboration with K. Allen4, L. Bunt5 and S. Ben-IHaiM6 July 1990

  15. Anatomical route of invasion and protective mucosal immunity in Trypanosoma cruzi conjunctival infection.

    PubMed

    Giddings, O K; Eickhoff, C S; Smith, T J; Bryant, L A; Hoft, D F

    2006-10-01

    Trypanosoma cruzi is a protozoan parasite that can initiate mucosal infection after conjunctival exposure. The anatomical route of T. cruzi invasion and spread after conjunctival parasite contamination remains poorly characterized. In the present work we have identified the sites of initial invasion and replication after contaminative conjunctival challenges with T. cruzi metacyclic trypomastigotes using a combination of immunohistochemical and real-time PCR confirmatory techniques in 56 mice between 3 and 14 days after challenge. Our results demonstrate that the predominant route of infection involves drainage of parasites through the nasolacrimal duct into the nasal cavity. Initial parasite invasion occurs within the ductal and respiratory epithelia. After successive waves of intracellular replication and cell-to-cell spread, parasites drain via local lymphatic channels to lymph nodes and then disseminate through the blood to distant tissues. This model of conjunctival challenge was used to identify immune responses associated with protection against mucosal infection. Preceding mucosal infection induces mucosal immunity, resulting in at least 50-fold reductions in recoverable tissue parasite DNA in immune mice compared to controls 10 days after conjunctival challenge (P < 0.05). Antigen-specific gamma interferon production by T cells was increased at least 100-fold in cells harvested from immune mice (P < 0.05). Mucosal secretions containing T. cruzi-specific secretory immunoglobulin A harvested from immune mice were shown to protect against mucosal parasite infection (P < 0.05), demonstrating that mucosal antibodies can play a role in T. cruzi immunity. This model provides an important tool for detailed studies of mucosal immunity necessary for the development of mucosal vaccines.

  16. Hyperaemic changes in forearm skin perfusion and RBC concentration after increasing occlusion times.

    PubMed

    Farnebo, Simon; Thorfinn, Johan; Henricson, Joakim; Tesselaar, Erik

    2010-12-01

    Tissue occlusion and the hyperaemic response upon reperfusion can be used as a tool to assess microvascular function in various vascular diseases. Currently, laser Doppler flowmetry (LDF) is applied most often to measure hyperaemic responses. In this study, we have applied tissue viability imaging (TiVi) and LDF to measure the change in red blood cell concentration and perfusion in the skin after occlusions of the forearm with increasing duration. We have found that there is a strong correlation between the changes in perfusion and red blood cell (RBC) concentration during post-occlusive hyperaemia (perfusion: r=0.80; RBC concentration: r=0.94). This correlation increases with longer occlusion durations (1, 5 and 10min). Furthermore, for both perfusion and RBC concentration, the maximum responses (perfusion: r(2)=0.59; RBC concentration: r(2)=0.78) and the recovery times (perfusion: r(2)=0.62; RBC concentration: r(2)=0.91) increase linearly with the duration of the occlusion. Maximum responses and recovery times were more reproducible for RBC concentration (as measured with TiVi) than for perfusion (as measured with LDF). These results show that perfusion and RBC concentration are related during post-occlusive hyperaemia and that TiVi can be used as a tool in the assessment of hyperaemic responses that has advantages in terms of reproducibility, sensitivity and ease of use.

  17. 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.

  18. The Development of an AIDS Mucosal Vaccine

    PubMed Central

    Tang, Xian; Chen, Zhiwei

    2010-01-01

    It is well known that mucosal tissues contain the largest surface area of the human body and are the front line of natural host defense against various pathogens. In fact, more than 80% of infectious disease pathogens probably gain entry into the susceptible human hosts through open mucosal surfaces. Human immunodeficiency virus type one (HIV-1), a mainly sexually transmitted virus, also primarily targets the vaginal and gastrointestinal mucosa as entry sites for viral transmission, seeding, replication and amplification. Since HIV-1 establishes its early replication in vaginal or rectal mucosal tissues, the induction of sufficient mucosal immunity at the initial site of HIV-1 transmission becomes essential for a protective vaccine. However, despite the fact that current conventional vaccine strategies have remained unsuccessful in preventing HIV-1 infection, sufficient financial support and resources have yet to be given to develop a vaccine able to elicit protective mucosal immunity against sexual transmissions. Interestingly, Chinese ancestors invented variolation through intranasal administration about one thousand years ago, which led to the discovery of a successful smallpox vaccine and the final eradication of the disease. It is the hope for all mankind that the development of a mucosal AIDS vaccine will ultimately help control the AIDS pandemic. In order to discover an effective mucosal AIDS vaccine, it is necessary to have a deep understanding of mucosal immunology and to test various mucosal vaccination strategies. PMID:21994611

  19. Topical therapy for mucosal yeast infections.

    PubMed

    Summers, Paul R

    2011-01-01

    Mucosal yeast infection is best understood as a consequence of compromised mucosal cell-mediated and innate immunity. Defense against oral candidiasis is dominantly cell mediated. The innate immune system may play the main role in regulating vulvovaginal yeast infection. Conditions that compromise cell-mediated immunity such as leukemia, severe illness and HIV infection must be considered as predisposing factors for recurrent oral candidiasis. Compromise of vaginal innate immunity due to mucosal allergy or due to a genetic defect such as mannose-binding lectin deficiency contributes to chronic vulvovaginal yeast infection. Treatment of cofactors must be considered in order to achieve control in recurrent mucosal yeast infection.

  20. 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

  1. Humoral Control of Regional Blood Flow in Hemorrhagic Shock in Non-Resuscitated and Resuscitated Animals.

    DTIC Science & Technology

    1987-07-17

    to perfusion with autologous normal (non-shock) blood. This increased resistance could be eliminated with phentolamine . However, oxygen consumption...perfusion with normal blood of 2.1 resistance units during perfusion with shock blood (pɘ.001). In a total of 17 phentolamine treated pig limbs...mL/min for normal blood and 1.4 mL/min for shock blood. None of these differences was statistically significant. The findings show that phentolamine

  2. Blue laser light increases perfusion of a skin flap via release of nitric oxide from hemoglobin.

    PubMed

    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 microM 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.

  3. Pulmonary ventilation/perfusion scan

    MedlinePlus

    ... JavaScript. A pulmonary ventilation/perfusion scan involves two nuclear scan tests to measure breathing (ventilation) and circulation ( ... In: Mettler FA, Guiberteau MJ, eds. Essentials of Nuclear Medicine Imaging . 6th ed. Philadelphia, PA: Elsevier Saunders; ...

  4. A novel extracorporeal kidney perfusion system: a concept model.

    PubMed

    Szajer, Michael; Shah, Gaurang; Kittur, Dilip; Searles, Bruce; Li, Lu; Bruch, David; Darling, Edward

    2004-01-01

    The number of patients awaiting kidney transplantation has more than doubled in the past decade while the number of available donor organs has seen only a modest increase, leading to a critical shortage of organs. In response to this extreme shortage, the criteria for accepting organs have been modified to include marginal donors such as non-heart beating donors (NHBD). In these kidneys, determining viability is important for success of transplantation. Therefore, a study was undertaken to develop a system that would allow the extracorporeal assessment of function and compatibility of the donor organ before the patient is exposed to the risks associated with surgery. Following bilateral nephrectomy, the kidneys of 10 pigs (approximately 30 kg) were connected to a commercially available hypothermic pulsatile kidney perfusion apparatus. This system was modified to allow for normothermic pulsatile renal perfusion using the potential recipient's blood, via vascular access. These kidneys were perfused with the animal's blood for a minimum of two hours while various parameters were monitored. Perfusion pressures were kept between 60 and 90 mmHg, which correlated to flows between 70 and 150 mL/min. A decrease in perfusion pressure with a concomitant rise in flow over the two-hour period served as a good predictor of a viable and compatible graft. The modified kidney preservation system allows the normothermic, pulsatile extracorporeal perfusion of donor kidneys with the ability to monitor resistance to flow and urine production. This model also allows observation of the kidney for signs of hyperacute rejection. Further research needs to be conducted in order to determine if the system represents a methodology to increase the pool of available donor organs.

  5. Cardiac Magnetic Resonance Myocardial Perfusion Reserve Index Is Reduced in Women With Coronary Microvascular Dysfunction: A National Heart, Lung and Blood Institute-Sponsored Study From the Women's Ischemia Syndrome Evaluation (WISE)

    PubMed Central

    Thomson, Louise E.J.; Wei, Janet; Agarwal, Megha; Haft-Baradaran, Afsaneh; Shufelt, Chrisandra; Mehta, Puja K.; Gill, Edward; Johnson, B. Delia; Kenkre, Tanya; Handberg, Eileen; Li, Debiao; Sharif, Behzad; Berman, Daniel S.; Petersen, John; Pepine, Carl J.; Bairey Merz, C. Noel

    2015-01-01

    Background Women with signs and symptoms of ischemia and no obstructive coronary artery disease often have coronary microvascular dysfunction (CMD), diagnosed by invasive coronary reactivity testing (CRT). While traditional noninvasive stress imaging is often normal in CMD, cardiac magnetic resonance imaging (CMRI) may be able to detect CMD in this population. Methods and Results Vasodilator stress CMRI was performed in 118 women with suspected CMD who had undergone CRT and 21 asymptomatic reference subjects. Semi quantitative evaluation of the first-pass perfusion images was completed to determine myocardial perfusion reserve index (MPRI). The relationship between CRT findings and MPRI was examined by Pearson correlations, logistic regression and sensitivity/specificity. Symptomatic women had lower mean pharmacologic stress MPRI compared to reference subjects (1.71±0.43 vs. 2.23±0.37, p<0.0001). Lower MPRI was predictive of one or more abnormal CRT variables (OR = 0.78 [0.70, 0.88], p<0.0001, c-statistic 0.78 [0.68, 0.88]). An MPRI threshold of 1.84 predicted CRT abnormality with sensitivity 73% and specificity 74%. Conclusions Noninvasive CMRI MPRI can detect CMD defined by invasive CRT. Further work is aimed to optimize the non-invasive identification and management of CMD patients. PMID:25801710

  6. BOLD-Perfusion Coupling during Monocular and Binocular Stimulation

    PubMed Central

    Gauthier, Claudine; Hoge, Richard D.

    2008-01-01

    Previous studies have suggested that during selective activation of a subset of the zones comprising a columnar system in visual cortex, perfusion increases uniformly in all columns of the system, while increases in oxidative metabolism occur predominantly in the activated columns. This could lead to disproportionately large blood oxygenation level-dependent (BOLD) signal increases for a given flow increase during monocular (relative to binocular) stimulation, due to contributions from columns which undergo large increases in perfusion with little or no change in oxidative metabolism. In the present study, we sought to test this hypothesis by measuring BOLD-perfusion coupling ratios in spatially averaged signals over V1 during monocular and binocular visual stimulation. It was found that, although withholding input to one eye resulted in statistically significant decreases in BOLD and perfusion signals in primary visual cortex, the ratio between BOLD and perfusion increases did not change significantly. These results do not support a gross mismatch between spatial patterns of flow and metabolism response during monocular stimulation. PMID:18350120

  7. Modelling of temperature and perfusion during scalp cooling.

    PubMed

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

    2005-09-07

    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 degrees C to 18.3 degrees 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 degrees C to 21.8 degrees C, which in turn reduced relative perfusion to 13% and 33%, respectively.

  8. 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.

  9. Brain perfusion asymmetry in patients with oral somatic delusions.

    PubMed

    Umezaki, Yojiro; Katagiri, Ayano; Watanabe, Motoko; Takenoshita, Miho; Sakuma, Tomomi; Sako, Emi; Sato, Yusuke; Toriihara, Akira; Uezato, Akihito; Shibuya, Hitoshi; Nishikawa, Toru; Motomura, Haruhiko; Toyofuku, Akira

    2013-06-01

    Oral cenesthopathy is a somatic delusion or hallucination involving the oral area and is categorized as a delusional disorder, somatic type. The pathophysiology of this intractable condition remains obscure. In this study, we clarified the pathophysiology of oral cenesthopathy by evaluating regional brain perfusion. We performed single photon emission computed tomography (SPECT) using (99m)Tc-ethylcysteinate dimer in 16 subjects (cenesthopathy:control = 8:8). The SPECT images were visually assessed qualitatively, and quantitative analyses were also performed using a three-dimensional stereotactic region-of-interest template. The visual assessment revealed a right > left perfusion asymmetry in broad areas of the brain among the patients. The quantitative analysis confirmed that the regional cerebral blood flow values on the right side were significantly larger than those on the left side for most areas of the brain in the patients. A comparison of the R/(R + L) ratios in both groups confirmed the significant brain perfusion asymmetry between the two sides in the callosomarginal, precentral, and temporal regions in the patients. Qualitative evaluation of the SPECT images revealed right > left brain perfusion asymmetry in broad regions of the brain. Moreover, the quantitative analyses confirmed the perfusion asymmetry between the two sides in the frontal and temporal areas. Those may provide the key for elucidation of the pathophysiology of oral cenesthopathy.

  10. Mucosal immunity and probiotics in fish.

    PubMed

    Lazado, Carlo C; Caipang, Christopher Marlowe A

    2014-07-01

    Teleost mucosal immunity has become the subject of unprecedented research studies in recent years because of its diversity and defining characteristics. Its immune repertoire is governed by the mucosa-associated lymphoid tissues (MALT) which are divided into gut-associated lymphoid tissues (GALT), skin-associated lymphoid tissues (SALT), and gill-associated lymphoid tissues (GIALT). The direct contact with its immediate environment makes the mucosal surfaces of fish susceptible to a wide variety of pathogens. The inherent immunocompetent cells and factors in the mucosal surfaces together with the commensal microbiota have pivotal role against pathogens. Immunomodulation is a popular prophylactic strategy in teleost and probiotics possess this beneficial feature. Most of the studies on the immunomodulatory properties of probiotics in fish mainly discussed their impacts on systemic immunity. In contrast, few of these studies discussed the immunomodulatory features of probiotics in mucosal surfaces and are concentrated on the influences in the gut. Significant attention should be devoted in understanding the relationship of mucosal immunity and probiotics as the present knowledge is limited and are mostly based on extrapolations of studies in humans and terrestrial vertebrates. In the course of the advancement of mucosal immunity and probiotics, new perspectives in probiotics research, e.g., probiogenomics have emerged. This review affirms the relevance of probiotics in the mucosal immunity of fish by revisiting and bridging the current knowledge on teleost mucosal immunity, mucosal microbiota and immunomodulation of mucosal surfaces by probiotics. Expanding the knowledge of immunomodulatory properties of probiotics especially on mucosal immunity is essential in advancing the use of probiotics as a sustainable and viable strategy for successful fish husbandry.

  11. Modulation of gut mucosal biofilms.

    PubMed

    Kleessen, Brigitta; Blaut, Michael

    2005-04-01

    Non-digestible inulin-type fructans, such as oligofructose and high-molecular-weight inulin, have been shown to have the ability to alter the intestinal microbiota composition in such a way that members of the microbial community, generally considered as health-promoting, are stimulated. Bifidobacteria and lactobacilli are the most frequently targeted organisms. Less information exists on effects of inulin-type fructans on the composition, metabolism and health-related significance of bacteria at or near the mucosa surface or in the mucus layer forming mucosa-associated biofilms. Using rats inoculated with a human faecal flora as an experimental model we have found that inulin-type fructans in the diet modulated the gut microbiota by stimulation of mucosa-associated bifidobacteria as well as by partial reduction of pathogenic Salmonella enterica subsp. enterica serovar Typhimurium and thereby benefit health. In addition to changes in mucosal biofilms, inulin-type fructans also induced changes in the colonic mucosa stimulating proliferation in the crypts, increasing the release of mucins, and altering the profile of mucin components in the goblet cells and epithelial mucus layer. These results indicate that inulin-type fructans may stabilise the gut mucosal barrier. Dietary supplementation with these prebiotics could offer a new approach to supporting the barrier function of the mucosa.

  12. Antimicrobials, mucosal coating agents, anesthetics, analgesics, and nutritional supplements for alimentary tract mucositis.

    PubMed

    Barasch, Andrei; Elad, Sharon; Altman, Arnold; Damato, Kathryn; Epstein, Joel

    2006-06-01

    This review focuses on the value of several groups of agents for the prevention and treatment of mucositis. The review refers to alimentary mucositis as a generalized term that includes oral mucositis and gastrointestinal mucositis. This paper is part of the systematic review made by the mucositis study group which operates in the Multinational Association of Supportive Care in Cancer (MASCC)/International Society of Oral Oncology (ISOO). Several new guidelines are suggested in this review as an update to the primary systematic review that was published by the same group in 2004.

  13. Localized Pemphigus Vegetans without Mucosal Involvement.

    PubMed

    Jain, Vk; Jindal, N; Imchen, S

    2014-03-01

    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.

  14. 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

  15. Mucosal Wave Measurement and Visualization Techniques

    PubMed Central

    Krausert, Christopher R.; Olszewski, Aleksandra E.; Taylor, Lindsay N.; McMurray, James S.; Dailey, Seth H.; Jiang, Jack J.

    2010-01-01

    Organized vibration of the vocal folds is critical to high quality voice production. When the vocal folds oscillate, the superficial tissue of the vocal fold is displaced in a wave-like fashion, creating the so called “mucosal wave”. Because the mucosal wave is dependent on vocal fold structure, physical alterations of that structure cause mucosal wave abnormalities. Visualization and quantification of mucosal wave properties have become useful parameters in diagnosing and managing vocal fold pathology. Mucosal wave measurement provides information about vocal fold characteristics that cannot be determined with other assessment techniques. Here, we discuss the benefits, disadvantages, and clinical applicability of the different mucosal wave measurement techniques, such as electroglottography (EGG), photoglottography (PGG), and ultrasound and visualization techniques that include videokymography (VKG), stroboscopy, and high-speed digital imaging (HSDI). The various techniques and their specific uses are reviewed with the intention of helping researchers and clinicians choose a method for a given situation and understand its limitations as well as its potential applications. Recent applications of these techniques for quantitative assessment demonstrate that additional research must be conducted to realize the full potential of these tools. Evaluations of existing research and recommendations for future research are given to promote both the quantitative study of the mucosal wave through accurate and standardized measurement of mucosal wave parameters and the development of reliable methods with which physicians can diagnose vocal disorders. PMID:20471798

  16. Mucosal Immunosenescence In The Gastrointestinal Tract

    PubMed Central

    Sato, Shintaro; Kiyono, Hiroshi; Fujihashi, Kohtaro

    2014-01-01

    It has been shown that pathogen-specific secretory IgA (SIgA) antibody (Ab) is the major player at mucosal surfaces for host defense. However, alterations in the mucosal immune system occur in advanced aging which results in a failure of induction of SIgA Abs for protection from infectious diseases. Signs of mucosal senescence first appear in the gut immune system. Further, changes in the intestinal microbiota most likely influence mucosal immunity. To overcome the immunological aging decline in mucosal immunity, several adjuvant systems including mucosal dendritic cell (DC) targeting have been shown to be attractive and effective immunological strategies. Similarly, antigen (Ag) uptake-M cells are ideal targets for facilitating Ag-specific mucosal immune responses. However, the numbers of M cells are reduced in aged mice. In this regard, Spi-B, an essential transcription factor for the functional and structural differentiation of M cells could be a potent strategy for the induction of effective mucosal immunity in aging. PMID:25531743

  17. Impaired Tissue Oxygenation in Metabolic Syndrome Requires Increased Microvascular Perfusion Heterogeneity.

    PubMed

    Mason McClatchey, P; Wu, Fan; Olfert, I Mark; Ellis, Christopher G; Goldman, Daniel; Reusch, Jane E B; Frisbee, Jefferson C

    2017-02-01

    Metabolic syndrome (MS) in obese Zucker rats (OZR) is associated with impaired skeletal muscle performance and blunted hyperemia. Studies suggest that reduced O2 diffusion capacity is required to explain compromised muscle performance and that heterogeneous microvascular perfusion distribution is critical. We modeled tissue oxygenation during muscle contraction in control and OZR skeletal muscle using physiologically realistic relationships. Using a network model of Krogh cylinders with increasing perfusion asymmetry and increased plasma skimming, we predict increased perfusion heterogeneity and decreased muscle oxygenation in OZR, with partial recovery following therapy. Notably, increasing O2 delivery had less impact on VO2 than equivalent decreases in O2 delivery, providing a mechanism for previous empirical work associating perfusion heterogeneity and impaired O2 extraction. We demonstrate that increased skeletal muscle perfusion asymmetry is a defining characteristic of MS and must be considered to effectively model and understand blood-tissue O2 exchange in this model of human disease.

  18. Protective effect of Matricaria chamomilla on ethanol-induced acute gastric mucosal injury in rats.

    PubMed

    Cemek, Mustafa; Yilmaz, Ezgi; Büyükokuroğlu, Mehmet Emin

    2010-07-01

    The antiulcerogenic and antioxidant properties of Matricaria chamomilla L. (Compositae) hydroalcoholic extract (MCE) on ethanol-induced gastric mucosal injury were investigated in rats. After the induction of gastric mucosal injury, all groups were sacrificed; the gastric ulcer index was calculated, and malondialdehyde (MDA) and reduced glutathione (GSH) in whole blood and gastric tissue, and serum ascorbic acid, retinol, and beta-carotene levels were measured in all groups. Pretreatment with MCE at some doses significantly reduced gastric lesions. Again, some doses of MCE significantly reduced the MDA, and significantly increased GSH levels in gastric tissue or whole blood. Serum beta-carotene and retinol levels were significantly higher in the 200 mg/kg MCE-administered group with respect to control. As a result, MCE clearly has a protective effect against ethanol-induced gastric mucosal lesions, and this effect, at least in part, depends upon the reduction in lipid peroxidation and augmentation in antioxidant activity.

  19. Mucosal vaccines: a paradigm shift in the development of mucosal adjuvants and delivery vehicles.

    PubMed

    Srivastava, Atul; Gowda, Devegowda Vishakante; Madhunapantula, SubbaRao V; Shinde, Chetan G; Iyer, Meenakshi

    2015-04-01

    Mucosal immune responses are the first-line defensive mechanisms against a variety of infections. Therefore, immunizations of mucosal surfaces from which majority of infectious agents make their entry, helps to protect the body against infections. Hence, vaccinization of mucosal surfaces by using mucosal vaccines provides the basis for generating protective immunity both in the mucosal and systemic immune compartments. Mucosal vaccines offer several advantages over parenteral immunization. For example, (i) ease of administration; (ii) non-invasiveness; (iii) high-patient compliance; and (iv) suitability for mass vaccination. Despite these benefits, to date, only very few mucosal vaccines have been developed using whole microorganisms and approved for use in humans. This is due to various challenges associated with the development of an effective mucosal vaccine that can work against a variety of infections, and various problems concerned with the safe delivery of developed vaccine. For instance, protein antigen alone is not just sufficient enough for the optimal delivery of antigen(s) mucosally. Hence, efforts have been made to develop better prophylactic and therapeutic vaccines for improved mucosal Th1 and Th2 immune responses using an efficient and safe immunostimulatory molecule and novel delivery carriers. Therefore, in this review, we have made an attempt to cover the recent advancements in the development of adjuvants and delivery carriers for safe and effective mucosal vaccine production.

  20. Mucosal vaccines: novel strategies and applications for the control of pathogens and tumors at mucosal sites.

    PubMed

    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.

  1. Visualization of myocardial perfusion derived from coronary anatomy.

    PubMed

    Termeer, Maurice; Oliván Bescós, Javier; Breeuwer, Marcel; Vilanova, Anna; Gerritsen, Frans; Gröller, M Eduard; Nagel, Eike

    2008-01-01

    Visually assessing the effect of the coronary artery anatomy on the perfusion of the heart muscle in patients with coronary artery disease remains a challenging task. We explore the feasibility of visualizing this effect on perfusion using a numerical approach. We perform a computational simulation of the way blood is perfused throughout the myocardium purely based on information from a three-dimensional anatomical tomographic scan. The results are subsequently visualized using both three-dimensional visualizations and bull's eye plots, partially inspired by approaches currently common in medical practice. Our approach results in a comprehensive visualization of the coronary anatomy that compares well to visualizations commonly used for other scanning technologies. We demonstrate techniques giving detailed insight in blood supply, coronary territories and feeding coronary arteries of a selected region. We demonstrate the advantages of our approach through visualizations that show information which commonly cannot be directly observed in scanning data, such as a separate visualization of the supply from each coronary artery. We thus show that the results of a computational simulation can be effectively visualized and facilitate visually correlating these results to for example perfusion data.

  2. Evaluation of Perfusion Quantification Methods with Ultrasound Contrast Agents in a Machine-Perfused Pig Liver.

    PubMed

    Averkiou, M; Keravnou, C P; Izamis, M L; Leen, E

    2016-05-03

    Purpose: To evaluate dynamic contrast-enhanced ultrasound (DCEUS) as a tool for measuring blood flow in the macro- and microcirculation of an ex-vivo machine-perfused pig liver and to confirm the ability of DCEUS to accurately detect induced flow rate changes so that it could then be used clinically for monitoring flow changes in liver tumors. Materials and Methods: Bolus injections of contrast agents in the hepatic artery (HA) and portal vein (PV) were administered to 3 machine-perfused pig livers. Flow changes were induced by the pump of the machine perfusion system. The induced flow rates were of clinical relevance (150 - 400 ml/min for HA and 400 - 1400 ml/min for PV). Quantification parameters from time-intensity curves [rise time (RT), mean transit time (MTT), area under the curve (AUC) and peak intensity (PI)] were extracted in order to evaluate whether the induced flow changes were reflected in these parameters. Results: A linear relationship between the image intensity and the microbubble concentration was confirmed first, while time parameters (RT and MMT) were found to be independent of concentration. The induced flow changes which propagated from the larger vessels to the parenchyma were reflected in the quantification parameters. Specifically, RT, MTT and AUC correlated with flow rate changes. Conclusion Machine-perfused pig liver is an excellent test bed for DCEUS quantification approaches for the study of the hepatic vascular networks. DCEUS quantification parameters (RT, MTT, and AUC) can measure relative flow changes of about 20 % and above in the liver vasculature. DCEUS quantification is a promising tool for real-time monitoring of the vascular network of tumors.

  3. Mucositis management in patients with cancer.

    PubMed

    Keefe, Dorothy M K

    2006-04-01

    Mucositis is an important toxicity to be aware of in anticancer therapy. It contributes to a reduction in cure rates from cancer. Until recently, it has been poorly understood and therefore has not been well managed. It causes patient distress, delays in treatment administration, and reductions in dose intensity, and it costs the health-care system a large amount of money. Mucositis has traditionally been associated more with hematologic malignancies than with solid tumors, because the incidence of severe mucositis has been much higher with the high-dose chemotherapy regimens used in hematologic malignancies. However, the chemotherapy used in solid tumors also causes mucositis and deserves further study. The separation between oral and gastrointestinal mucositis is potentially false and is being removed, with much research now investigating the entire alimentary canal. There are similarities and differences between radiation therapy- and chemotherapy-induced mucositis, and these have implications for treatment and prevention scheduling and type. Risk prediction is another area that requires more work, but there is real hope that, in the future, we might be able to predict who will suffer from mucositis and in which parts of the alimentary canal, thus enabling us to appropriately target the newer antimucotoxic therapies. The Mucositis Study Goup of the Multinational Association for Supportive Care in Cancer has recently published management guidelines for oral and gastrointestinal mucositis and is in the process of updating them. The guidelines serve as an excellent starting place for future mucositis research because they not only review the available treatments but also discuss mechanisms and epidemiology.

  4. 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.

  5. 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

  6. Intestinal mucosal atrophy and adaptation.

    PubMed

    Shaw, Darcy; Gohil, Kartik; Basson, Marc D

    2012-11-28

    Mucosal adaptation is an essential process in gut homeostasis. The intestinal mucosa adapts to a range of pathological conditions including starvation, short-gut syndrome, obesity, and bariatric surgery. Broadly, these adaptive functions can be grouped into proliferation and differentiation. These are influenced by diverse interactions with hormonal, immune, dietary, nervous, and mechanical stimuli. It seems likely that clinical outcomes can be improved by manipulating the physiology of adaptation. This review will summarize current understanding of the basic science surrounding adaptation, delineate the wide range of potential targets for therapeutic intervention, and discuss how these might be incorporated into an overall treatment plan. Deeper insight into the physiologic basis of adaptation will identify further targets for intervention to improve clinical outcomes.

  7. Intestinal mucosal atrophy and adaptation

    PubMed Central

    Shaw, Darcy; Gohil, Kartik; Basson, Marc D

    2012-01-01

    Mucosal adaptation is an essential process in gut homeostasis. The intestinal mucosa adapts to a range of pathological conditions including starvation, short-gut syndrome, obesity, and bariatric surgery. Broadly, these adaptive functions can be grouped into proliferation and differentiation. These are influenced by diverse interactions with hormonal, immune, dietary, nervous, and mechanical stimuli. It seems likely that clinical outcomes can be improved by manipulating the physiology of adaptation. This review will summarize current understanding of the basic science surrounding adaptation, delineate the wide range of potential targets for therapeutic intervention, and discuss how these might be incorporated into an overall treatment plan. Deeper insight into the physiologic basis of adaptation will identify further targets for intervention to improve clinical outcomes. PMID:23197881

  8. A poroelastic model valid in large strains with applications to perfusion in cardiac modeling

    NASA Astrophysics Data System (ADS)

    Chapelle, D.; Gerbeau, J.-F.; Sainte-Marie, J.; Vignon-Clementel, I. E.

    2009-12-01

    This paper is motivated by the modeling of blood flows through the beating myocardium, namely cardiac perfusion. As in other works, perfusion is modeled here as a flow through a poroelastic medium. The main contribution of this study is the derivation of a general poroelastic model valid for a nearly incompressible medium which experiences finite deformations. A numerical procedure is proposed to iteratively solve the porous flow and the nonlinear poroviscoelastic problems. Three-dimensional numerical experiments are presented to illustrate the model. The first test cases consist of typical poroelastic configurations: swelling and complete drainage. Finally, a simulation of cardiac perfusion is presented in an idealized left ventricle embedded with active fibers. Results show the complex temporal and spatial interactions of the muscle and blood, reproducing several key phenomena observed in cardiac perfusion.

  9. Omeprazole promotes proximal duodenal mucosal bicarbonate secretion in humans.

    PubMed

    Mertz-Nielsen, A; Hillingsø, J; Bukhave, K; Rask-Madsen, J

    1996-01-01

    The proton pump inhibitor, omeprazole, surprisingly resulted in higher rates of proximal duodenal mucosal bicarbonate secretion than previously reported using an H2 receptor antagonist for gastric acid inhibition. Gastroduodenal perfusions were performed in healthy volunteers to evaluate whether this incidental finding is explained by more potent gastric acid inhibition by omeprazole or might be caused by the different mode of drug action. Basal and stimulated gastric and duodenal bicarbonate secretion rates were measured in the same subjects in control experiments (n = 17) and after pretreatment with high dose omeprazole (n = 17) and ranitidine (n = 9), respectively, by use of a technique permitting simultaneous measurements. Concentrations of bicarbonate were measured in the respective effluents by the method of back titration. Both omeprazole and ranitidine completely inhibited gastric acid secretion (pH 6.9 v 6.8; p > 0.05). Omeprazole caused higher rates of basal (mean (SEM)) (597 (48) v 351 (39) mumol/h; p < 0.02) and vagally stimulated (834 (72) v 474 (66) mumol/h; p < 0.02), but not acid stimulated (3351 (678) v 2550 (456) mumol/h; p > 0.05) duodenal bicarbonate secretion compared with control experiments. Also the combination of omeprazole and ranitidine increased (p = 0.05) duodenal bicarbonate secretion, while ranitidine alone caused no change in either basal or stimulated secretion. In the stomach basal as well as vagally stimulated bicarbonate secretion was independent of the means of acid inhibition. These results show that the proton pump inhibitor, omeprazole, promotes proximal duodenal mucosal bicarbonate secretion apparently independent of its gastric acid inhibitory effect. The mechanism of action remains speculative.

  10. Omeprazole promotes proximal duodenal mucosal bicarbonate secretion in humans.

    PubMed Central

    Mertz-Nielsen, A; Hillingsø, J; Bukhave, K; Rask-Madsen, J

    1996-01-01

    The proton pump inhibitor, omeprazole, surprisingly resulted in higher rates of proximal duodenal mucosal bicarbonate secretion than previously reported using an H2 receptor antagonist for gastric acid inhibition. Gastroduodenal perfusions were performed in healthy volunteers to evaluate whether this incidental finding is explained by more potent gastric acid inhibition by omeprazole or might be caused by the different mode of drug action. Basal and stimulated gastric and duodenal bicarbonate secretion rates were measured in the same subjects in control experiments (n = 17) and after pretreatment with high dose omeprazole (n = 17) and ranitidine (n = 9), respectively, by use of a technique permitting simultaneous measurements. Concentrations of bicarbonate were measured in the respective effluents by the method of back titration. Both omeprazole and ranitidine completely inhibited gastric acid secretion (pH 6.9 v 6.8; p > 0.05). Omeprazole caused higher rates of basal (mean (SEM)) (597 (48) v 351 (39) mumol/h; p < 0.02) and vagally stimulated (834 (72) v 474 (66) mumol/h; p < 0.02), but not acid stimulated (3351 (678) v 2550 (456) mumol/h; p > 0.05) duodenal bicarbonate secretion compared with control experiments. Also the combination of omeprazole and ranitidine increased (p = 0.05) duodenal bicarbonate secretion, while ranitidine alone caused no change in either basal or stimulated secretion. In the stomach basal as well as vagally stimulated bicarbonate secretion was independent of the means of acid inhibition. These results show that the proton pump inhibitor, omeprazole, promotes proximal duodenal mucosal bicarbonate secretion apparently independent of its gastric acid inhibitory effect. The mechanism of action remains speculative. PMID:8566861

  11. Mucosal Vaccine Development Based on Liposome Technology

    PubMed Central

    Norling, Karin; Bally, Marta; Höök, Fredrik

    2016-01-01

    Immune protection against infectious diseases is most effective if located at the portal of entry of the pathogen. Hence, there is an increasing demand for vaccine formulations that can induce strong protective immunity following oral, respiratory, or genital tract administration. At present, only few mucosal vaccines are found on the market, but recent technological advancements and a better understanding of the principles that govern priming of mucosal immune responses have contributed to a more optimistic view on the future of mucosal vaccines. Compared to live attenuated vaccines, subcomponent vaccines, most often protein-based, are considered safer, more stable, and less complicated to manufacture, but they require the addition of nontoxic and clinically safe adjuvants to be effective. In addition, another limiting factor is the large antigen dose that usually is required for mucosal vaccines. Therefore, the combination of mucosal adjuvants with the recent progress in nanoparticle technology provides an attractive solution to these problems. In particular, the liposome technology is ideal for combining protein antigen and adjuvant into an effective mucosal vaccine. Here, we describe and discuss recent progress in nanoparticle formulations using various types of liposomes that convey strong promise for the successful development of the next generation of mucosal vaccines. PMID:28127567

  12. 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

  13. A Generic Bioheat Transfer Thermal Model for a Perfused Tissue

    PubMed Central

    Vaughan, J. Thomas

    2009-01-01

    A thermal model was needed to predict temperatures in a perfused tissue, which satisfied the following three criteria. One, the model satisfied conservation of energy. Two, the heat transfer rate from blood vessels to tissue was modeled without following a vessel path. Three, the model applied to any unheated and heated tissue. To meet these criteria, a generic bioheat transfer model (BHTM) was derived here by conserving thermal energy in a heated, vascularized, finite tissue and by making a few simplifying assumptions. Two linear, coupled differential equations were obtained with the following two variables: tissue volume averaged temperature and blood volume averaged temperature. The generic model was compared to the widely employed, empirical Pennes’ BHTM. The comparison showed that the Pennes’ perfusion term wCp(1−ε) should be interpreted as a local vasculature dependent heat transfer coefficient term. Suggestions are presented for further adaptations of the general BHTM for specific tissues using imaging techniques and numerical simulations. PMID:19640142

  14. Vasopressin, Sepsis, and Renal Perfusion - A VASST Deficit in Our Understanding

    DTIC Science & Technology

    2014-06-01

    JUN 2014 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Vasopressin, Sepsis, and Renal PerfusionâA VASST Deficit in Our...vasoconstric- tion within the renal vascular bed as evidenced by decreased renal blood flow (RBF) in vivo and increased renal vascular perfusion...decrease in renal per- fusion could potentially result in acute kidney injury (AKI), a syndrome that has been associated with increased mortality in the

  15. Animal models of mucositis: implications for therapy.

    PubMed

    Bowen, Joanne M; Gibson, Rachel J; Keefe, Dorothy M K

    2011-01-01

    Alimentary mucositis is a major acute complication in the clinical setting, occurring in a large percentage of patients undergoing cytotoxic therapy. One of the major problems with alimentary mucositis is that the underlying mechanisms behind its development are not entirely understood, which makes it extremely difficult to develop effective interventions. Animal models provide a critical source of knowledge when sampling from patients is unavailable or interventions are yet to be fully tested. This review focuses on the animal models used to increase our understanding of the mechanisms of mucositis and translate new antimucotoxic agents into clinical trials.

  16. 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.

  17. Viable neurons with luxury perfusion in hydrocephalus.

    PubMed

    Wong, C Y; Luciano, M G; MacIntyre, W J; Brunken, R C; Hahn, J F; Go, R T

    1997-09-01

    A woman with hydrocephalus due to aqueductal stenosis had functional imaging of cerebral perfusion and metabolism to demonstrate the effects of endoscopic third ventriculostomy--a new form of internal surgical shunting. Technetium-99m-ECD SPECT and 18F-FDG PET showed regional luxury perfusion at the left frontal region. Three months after a successful third ventriculostomy, a repeated imaging of cerebral perfusion and metabolism showed resolution of luxury perfusion and global improvement of both perfusion and metabolism. This concurred with postoperative clinical improvement. The paired imaging of cerebral perfusion and metabolism provides more information than just imaging perfusion or metabolism. Thus, the detection of perfusion and metabolism mismatch may open a new window of opportunity for surgical intervention.

  18. Targeting Mucosal Healing in Crohn's Disease

    PubMed Central

    Kakkar, Aarti; Wasan, Sharmeel K.

    2011-01-01

    The goal of medical treatment for Crohn's disease includes improving patients' quality of life while reducing the need for hospitalization and surgery. The current medical armamentarium includes 5-aminosalicylates, corticosteroids, immunomodulators, and biologic agents. In the past, response to treatment was measured by clinical improvement in symptoms; however, with the advent of disease-modifying medications, mucosal healing has emerged as an increasingly important goal of therapy. Mucosal healing, or endoscopic remission, is associated with increased rates of clinical remission, fewer hospitalizations, and fewer abdominal surgeries. Both the immunomodulator and biologic classes of medications are effective at inducing mucosal healing. Despite several limitations, mucosal healing has become a desirable and valid measure of disease activity. PMID:21869869

  19. Microbiota and mucosal immunity in amphibians.

    PubMed

    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.

  20. A regenerative approach towards mucosal fenestration closure.

    PubMed

    Gandi, Padma; Anumala, Naveen; Reddy, Amarender; Chandra, Rampalli Viswa

    2013-06-06

    Mucosal fenestration is an opening or an interstice through the oral mucosa. A lesion which occurs with greater frequency than generally realised, its occurrence is attributed to a myriad of causes. Mucogingival procedures including connective tissue grafts, free gingival grafts and lateral pedicle grafts are generally considered to be the treatment of choice in the closure of a mucosal fenestration. More often, these procedures are performed in conjunction with other procedures such as periradicular surgery and with bone grafts. However, the concomitant use of gingival grafts and bone grafts in mucosal fenestrations secondary to infections in sites exhibiting severe bone loss is highly debatable. In this article, we report two cases of mucosal fenestrations secondary to trauma and their management by regenerative periodontal surgery with the placement of guided tissue regeneration membrane and bone graft. The final outcome was a complete closure of the fenestration in both the cases.

  1. 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

  2. Mucosal Vaccination against Tuberculosis Using Inert Bioparticles

    PubMed Central

    Reljic, Rajko; Sibley, Laura; Huang, Jen-Min; Pepponi, Ilaria; Hoppe, Andreas; Hong, Huynh A.

    2013-01-01

    Needle-free, mucosal immunization is a highly desirable strategy for vaccination against many pathogens, especially those entering through the respiratory mucosa, such as Mycobacterium tuberculosis. Unfortunately, mucosal vaccination against tuberculosis (TB) is impeded by a lack of suitable adjuvants and/or delivery platforms that could induce a protective immune response in humans. Here, we report on a novel biotechnological approach for mucosal vaccination against TB that overcomes some of the current limitations. This is achieved by coating protective TB antigens onto the surface of inert bacterial spores, which are then delivered to the respiratory tract. Our data showed that mice immunized nasally with coated spores developed humoral and cellular immune responses and multifunctional T cells and, most importantly, presented significantly reduced bacterial loads in their lungs and spleens following pathogenic challenge. We conclude that this new vaccine delivery platform merits further development as a mucosal vaccine for TB and possibly also other respiratory pathogens. PMID:23959722

  3. Effects of long chain fatty acids on solute absorption: perfusion studies in the human jejunum.

    PubMed Central

    Ammon, H V; Thomas, P J; Phillips, S F

    1977-01-01

    Perfusion studies were performed in healthy volunteers to test the hypothesis that net fluid secretion induced by fatty acids is accompanied by parallel reduction in solute transport. Ricinoleic acid provoked a marked net secretion of fluid and concomitantly inhibited the absorption of all solutes tested; these included glucose, xylose, L-leucine, L-lysine, Folic acid, and 2-mono-olein. Oleic acid also reduced net fluid and solute transport, but was less potent in reducing solute absorption than was ricinoleic acid. When fluid secretion was induced osmotically with mannitol, glucose and xylose absorption was not affected. The mechanism for this generalised effect of fatty acids on solute absorption is uncertain, possibly nonspecific, and might be related to mucosal damage and altered mucosal permeability induced by these agents. PMID:590838

  4. Cholecystokinin but not ghrelin stimulates mucosal bicarbonate secretion in rat duodenum: independence of feeding status and cholinergic stimuli.

    PubMed

    Sjöblom, Markus; Lindqvist, Ramin; Bengtsson, Magnus W; Jedstedt, Gunilla; Flemström, Gunnar

    2013-05-10

    Cholecystokinin (CCK) is an important regulator of food digestion but its influence on small intestinal secretion has received little attention. We characterized effects of CCK-8, ghrelin and some related peptides on duodenal HCO3(-) secretion in vivo and demonstrated CCK-induced calcium signaling in acutely isolated enterocytes. A segment of proximal duodenum with intact blood supply was cannulated in situ in anaesthetized rats. Mucosal HCO3(-) secretion was continuously recorded (pH-stat). Peptides were administrated to the duodenum by close intra-arterial infusion. Clusters of duodenal enterocytes were attached to the bottom of a perfusion chamber. The intracellular calcium concentration ([Ca(2+)]i) was examined by dual-wavelength imaging. CCK-8 (3.0, 15 and 60 pmol/kg,h) caused dose-dependent increases (p<0.01) in duodenal alkaline secretion in both overnight fasted and continuously fed animals. The CCK1R-antagonist devazepide but neither the CCK2R-antagonist YMM022 nor the melatonin MT2-selective antagonist luzindole inhibited the rise in secretion. Atropine decreased sensitivity to CCK-8. The appetite-related peptide ghrelin was without effect on the duodenal secretion in fasted as well as fed animals. Superfusion with CCK-8 (1.0-50 nM) induced [Ca(2+)]i signaling in acutely isolated duodenal enterocytes. After an initial peak response, [Ca(2+)]i returned to near basal values within 3-5min. Devazepide but not YMM022 inhibited this [Ca(2+)]i response. Low doses of CCK-8 stimulate duodenal alkaline secretion and induce enterocyte [Ca(2+)]i signaling by an action at CCK1 receptors. The results point to importance of CCK in the rapid postprandial rise in mucosa-protective duodenal secretion.

  5. Perfusion decellularization of whole organs.

    PubMed

    Guyette, Jacques P; Gilpin, Sarah E; Charest, Jonathan M; Tapias, Luis F; Ren, Xi; Ott, Harald C

    2014-01-01

    The native extracellular matrix (ECM) outlines the architecture of organs and tissues. It provides a unique niche of composition and form, which serves as a foundational scaffold that supports organ-specific cell types and enables normal organ function. Here we describe a standard process for pressure-controlled perfusion decellularization of whole organs for generating acellular 3D scaffolds with preserved ECM protein content, architecture and perfusable vascular conduits. By applying antegrade perfusion of detergents and subsequent washes to arterial vasculature at low physiological pressures, successful decellularization of complex organs (i.e., hearts, lungs and kidneys) can be performed. By using appropriate modifications, pressure-controlled perfusion decellularization can be achieved in small-animal experimental models (rat organs, 4-5 d) and scaled to clinically relevant models (porcine and human organs, 12-14 d). Combining the unique structural and biochemical properties of native acellular scaffolds with subsequent recellularization techniques offers a novel platform for organ engineering and regeneration, for experimentation ex vivo and potential clinical application in vivo.

  6. 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.

  7. Polyamines and Gut Mucosal Homeostasis

    PubMed Central

    Timmons, Jennifer; Chang, Elizabeth T.; Wang, Jian-Ying; Rao, Jaladanki N.

    2012-01-01

    The epithelium of gastrointestinal (GI) mucosa has the most rapid turnover rate of any tissue in the body and its integrity is preserved through the dynamic balance between cell migration, proliferation, growth arrest and apoptosis. To maintain tissue homeostasis of the GI mucosa, the rates of epithelial cell division and apoptosis must be highly regulated by various extracellular and intracellular factors including cellular polyamines. Natural polyamines spermidine, spermine and their precursor putrescine, are organic cations in eukaryotic cells and are implicated in the control of multiple signaling pathways and distinct cellular functions. Normal intestinal epithelial growth depends on the available supply of polyamines to the dividing cells in the crypts, and polyamines also regulate intestinal epithelial cell (IEC) apoptosis. Although the specific molecular processes controlled by polyamines remains to be fully defined, increasing evidence indicates that polyamines regulate intestinal epithelial integrity by modulating the expression of various growth-related genes. In this review, we will extrapolate the current state of scientific knowledge regarding the roles of polyamines in gut mucosal homeostasis and highlight progress in cellular and molecular mechanisms of polyamines and their potential clinical applications. PMID:25237589

  8. Evaluation of anterior mediastinal solid tumors by CT perfusion: a preliminary study

    PubMed Central

    Bakan, Selim; Kandemirli, Sedat Giray; Dikici, Atilla Süleyman; Erşen, Ezel; Yıldırım, Onur; Samancı, Cesur; Batur, Şebnem; Olgun, Deniz Çebi; Kantarcı, Fatih; Akman, Canan

    2017-01-01

    PURPOSE We aimed to assess the role of computed tomography (CT) perfusion in differentiation of thymoma from thymic hyperplasia, lymphoma, thymic carcinoma, and lung cancer invading anterior mediastinum. METHODS In this study, 25 patients with an anterior mediastinal lesion underwent CT perfusion imaging from January 2015 to February 2016. Diagnoses included thymoma (n=7), thymic hyperplasia (n=8), lymphoma (n=4), thymic carcinoma (n=3), and invasive lung cancer (n=3). Lymphoma, thymic carcinoma, and lung cancer were grouped as malignant tumors for statistical analysis. Values for blood flow, blood volume, and permeability surface were measured in CT perfusion. RESULTS Blood flow and blood volume values were higher in thymoma in comparison to thymic hyperplasia; however, the difference was not statistically significant. Blood volume values were significantly higher in thymoma (mean, 11.4 mL/100 mL; range, 5.2–20.2 mL/100 mL) compared with lymphoma (mean, 5.3 mL/100 mL; range, 2.5–7.2 mL/100 mL) (P = 0.023). Blood flow and blood volume values were significantly higher in thymoma compared with non-thymoma malignant tumors (P = 0.025). CONCLUSION CT perfusion is helpful in differentiating thymoma from non-thymoma malignancies including lymphoma, thymic carcinoma, and invasive lung cancer involving the anterior mediastinum. PMID:27924778

  9. Thallium-201 myocardial perfusion imaging in myocarditis

    SciTech Connect

    Tamaki, N.; Yonekura, Y.; Kadota, K.; Kambara, H.; Torizuka, K.

    1985-08-01

    TI-201 myocardial perfusion imaging was performed in six patients with clinically documented myocarditis. Each case manifested electrocardiographic abnormalities with elevation of serum cardiac enzymes and no significant stenosis of the coronary arteries observed on angiogram. Resting TI-201 images were visually assessed by three observers. Focal perfusion defects were observed in three cases (50%), among which two showed multiple perfusion defects. Emission computed tomography using TI-201 clearly delineated multifocal lesions in the first case. On the other hand, no significant perfusion defects were noted in the remaining three cases. Thus, myocarditis should be considered as one of the disease entities that may produce perfusion defects on TI-201 myocardial imaging.

  10. 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.

  11. 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…

  12. Does machine perfusion decrease ischemia reperfusion injury?

    PubMed

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

    2014-06-01

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

  13. 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

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

    PubMed

    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.

  15. 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.

  16. 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

  17. 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

  18. Parkinson's disease-related perfusion and glucose metabolic brain patterns identified with PCASL-MRI and FDG-PET imaging

    PubMed Central

    Teune, Laura K.; Renken, Remco J.; de Jong, Bauke M.; Willemsen, Antoon T.; van Osch, Matthias J.; Roerdink, Jos B.T.M.; Dierckx, Rudi A.; Leenders, Klaus L.

    2014-01-01

    Introduction Under normal conditions, the spatial distribution of resting cerebral blood flow and cerebral metabolic rate of glucose are closely related. A relatively new magnetic resonance (MR) technique, pseudo-continuous arterial spin labeling (PCASL), can be used to measure regional brain perfusion. We identified a Parkinson's disease (PD)-related perfusion and metabolic covariance pattern in the same patients using PCASL and FDG-PET imaging and assessed (dis)similarities in the disease-related pattern between perfusion and metabolism in PD patients. Methods Nineteen PD patients and seventeen healthy controls underwent [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging. Of 14 PD patients and all healthy controls PCASL-MRI could be obtained. Data were analyzed using scaled subprofile model/principal component analysis (SSM/PCA). Results Unique Parkinson's disease-related perfusion and metabolic covariance patterns were identified using PCASL and FDG-PET in the same patients. The PD-related metabolic covariance brain pattern is in high accordance with previously reports. Also our disease-related perfusion pattern is comparable to the earlier described perfusion pattern. The most marked difference between our perfusion and metabolic patterns is the larger perfusion decrease in cortical regions including the insula. Conclusion We identified PD-related perfusion and metabolic brain patterns using PCASL and FDG-PET in the same patients which were comparable with results of existing research. In this respect, PCASL appears to be a promising addition in the early diagnosis of individual parkinsonian patients. PMID:25068113

  19. Viability of the vascularly perfused, recirculating rat intestine and intestine-liver preparations

    SciTech Connect

    Hirayama, H.; Xu, X.; Pang, K.S. )

    1989-08-01

    Function and stability of vascularly perfused, recirculating in situ rat intestine (I) and intestine-liver (IL) preparations were evaluated in fasted and nonfasted rats because these techniques may be readily applied in drug metabolism studies. The rat intestine was perfused with blood medium (7.5 ml/min) via the superior mesenteric artery, with the venous outflow draining into the portal vein, which, together with hepatic arterial flow (2.5 ml/min), constituted the total blood flow (10 ml/min) to the liver. Maintenance of intestinal membrane integrity was observed. Rapid ({sup 14}C)glucose absorption against a concentration gradient and a lack of ({sup 3}H)-polyethylene glycol 4000 (PEG 4000, less than 4%) and Evans blue absorption by the recirculating I and IL preparations resulted after bolus injections of these markers into the pyloric end of the duodenum. Other indexes that revealed stable intestinal and liver functions were the following: preservation of reservoir perfusate volume, constancy in perfusion pressure, bile flow, and hemoglobin concentrations, evidence of intestinal glucose utilization and liver glucose production, and a lack of significant leakage of serum glutamic oxalic transaminase. The intestine and liver consumed oxygen at relatively constant rates, but the consumption rates for the fasted tissues (I or L) were significantly higher than those for nonfasted tissues. These results indicate that the vascularly perfused I and IL preparations were maintained in a viable and stable state for a 2-h perfusion period.

  20. 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

  1. 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.

  2. 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.

  3. Transplacental transfer of nitrosodimethylamine in perfused human placenta.

    PubMed

    Annola, K; Heikkinen, A T; Partanen, H; Woodhouse, H; Segerbäck, D; Vähäkangas, K

    2009-03-01

    Nitrosodimethylamine (NDMA) is a carcinogenic compound present in tobacco smoke and food such as cured meat, smoked fish and beer. The O(6)-methylguanine formed in human cord blood in mothers highly exposed to such products implicates NDMA exposure of the fetus. Dual recirculating human placental perfusion was used to get direct evidence of the transplacental transfer of NDMA and DNA adduct formation in perfused human placenta. Eleven placentas from normal full-term pregnancies were collected immediately after delivery and an isolated lobule was perfused with 1 or 5 microM of (14)C-NDMA with a reference substance, antipyrine (0.1mg/ml) added to the maternal circulation. Perfusate samples were collected from both maternal and fetal circulations every half an hour for the first two hours and once per hour from thereon. NDMA was analyzed by scintillation counting and antipyrine by high performance liquid chromatography. The transfer of NDMA was comparable to that of antipyrine and probably occurred through passive diffusion, with the concentrations in maternal and fetal sides equilibrating in 2-3h. No indication of any effect by efflux transporters on NDMA kinetics was noticed in the experiments utilizing Caco-2 or MDCK- MDCKII-MDR1 cell culture monolayer in a transwell system, either. Furthermore, no NDMA-DNA-adducts were found after the perfusions and no DNA-binding of NDMA was seen in in vitro incubations with human placental microsomes from 8 additional placentas. Thus, our study demonstrates that the human fetus can be exposed to NDMA from the maternal circulation. According to this study and the literature, NDMA is not metabolized in full-term human placenta from healthy non-smoking, non-drinking mothers. It remains to be studied whether NDMA concentrations high enough to evoke fetal toxicity can be obtained from dietary sources.

  4. Cardiovascular tissue engineering I. Perfusion bioreactors: a review.

    PubMed

    Mironov, Vladimir; Kasyanov, Vladimir A; Yost, Michael J; Visconti, Richard; Twal, Waleed; Trusk, Thomas; Wen, Xuejun; Ozolanta, Iveta; Kadishs, Arnolds; Prestwich, Glenn D; Terracio, Louis; Markwald, Roger R

    2006-01-01

    Tissue engineering is a fast-evolving field of biomedical science and technology with future promise to manufacture living tissues and organs for replacement, repair, and regeneration of diseased organs. Owing to the specific role of hemodynamics in the development, maintenance, and functioning of the cardiovascular system, bioreactors are a fundamental of cardiovascular tissue engineering. The development of perfusion bioreactor technology for cardiovascular tissue engineering is a direct sequence of previous historic successes in extracorporeal circulation techniques. Bioreactors provide a fluidic environment for tissue engineered tissue and organs, and guarantee their viability, maturation, biomonitoring, testing, storage, and transportation. There are different types of bioreactors and they vary greatly in their size, complexity, and functional capabilities. Although progress in design and functional properties of perfusion bioreactors for tissue engineered blood vessels, heart valves, and myocardial patches is obvious, there are some challenges and insufficiently addressed issues, and room for bioreactor design improvement and performance optimization. These challenges include creating a triple perfusion bioreactor for vascularized tubular tissue engineered cardiac construct; designing and manufacturing fluidics-based perfused minibioreactors; incorporation of systematic mathematical modeling and computer simulation based on computational fluid dynamics into the bioreactor designing process; and development of automatic systems of hydrodynamic regime control. Designing and engineering of built-in noninvasive biomonitoring systems is another important challenge. The optimal and most efficient perfusion and conditioning regime, which accelerates tissue maturation of tissue-engineered constructs also remains to be determined. This is a first article in a series of reviews on critical elements of cardiovascular tissue engineering technology describing the current

  5. 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

  6. Tissue perfusion measurements: multiple-exposure laser speckle analysis generates laser Doppler-like spectra.

    PubMed

    Thompson, Oliver B; Andrews, Michael K

    2010-01-01

    Variations in skin perfusion are easily detected by laser speckle contrast maps, but a robust interpretation of the information has been lacking. We show that multiple-exposure laser speckle methods produce the same spectral information as laser Doppler methods when applied to targets with embedded moving scatterers. This enables laser speckle measurements to be interpreted more quantitatively. We do this by using computer simulation of speckle data, and by experimental measurements on Brownian motion and skin perfusion using a laser Doppler system and a multiple-exposure laser speckle system. The power spectral density measurements of the light fluctuations derived using both techniques are exactly equivalent. Dermal perfusion can therefore be measured by laser Doppler or laser speckle contrast methods. In particular, multiexposure laser speckle can be rapidly processed to generate a full-field map of the perfusion index proportional to the concentration and mean velocity of red blood cells.

  7. 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

  8. Early Support of Intracranial Perfusion

    DTIC Science & Technology

    2013-10-01

    automated real-time vital signs monitoring data” was funded by USAF (MSA); UM PI: Deborah Stein  The project, titled “Noninvasive intracranial pressure ...scoring of cerebral perfusion pressure and intracranial pressure provides a Brain Trauma Index that predicts outcome in patients with severe TBI... intracranial pressure dose index: Dynamic 3-D scoring in the assessment of Traumatic Brain Injury Proceedings of American Association for the Surgery of

  9. 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.

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

    SciTech Connect

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

    1989-02-01

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

  11. Quantitative myocardial perfusion measurement using CT perfusion: a validation study in a porcine model of reperfused acute myocardial infarction.

    PubMed

    So, Aaron; Hsieh, Jiang; Li, Jian-Ying; Hadway, Jennifer; Kong, Hua-Fu; Lee, Ting-Yim

    2012-06-01

    We validated a CT perfusion technique with beam hardening (BH) correction for quantitative measurement of myocardial blood flow (MBF). Acute myocardial infarction (AMI) was created in four pigs by occluding the distal LAD for 1 h followed by reperfusion. MBF was measured from dynamic contrast enhanced CT (DCE-CT) scanning of the heart, with correction of cardiac motion and BH, before ischemic insult and on day 7, 10 and 14 post. On day 14 post, radiolabeled microspheres were injected to measure MBF and the results were compared with those measured by CT perfusion. Excised hearts were stained with 2,3,5-triphenyltetrazolium chloride (TTC) to determine the relationship between MBF measured by CT Perfusion and myocardial viability. MBF measured by CT perfusion was strongly correlated with that by microspheres over a wide range of MBF values (R = 0.81, from 25 to 225 ml min(-1) 100 g(-1)). While MBF in the LAD territory decreased significantly from 98.4 ± 2.5 ml min(-1) 100 g(-1) at baseline to 32.2 ± 9.1 ml min(-1) 100 g(-1), P < 0.05 at day 7 and to 49.4 ± 9.3 ml min(-1) 100 g(-1), P < 0.05 at day 14, the decrease in remote myocardium (LCx territory) from baseline (103.9 ± 1.9 ml min(-1) 100 g(-1)) was minimal throughout the study (90.6 ± 5.1 ml min(-1) 100 g(-1) on day 14 post, P > 0.05). TTC staining confirmed incomplete infarction in the LAD territory and no infarction in the LCx territory. Microvascular obstruction in infarcted tissue resulted in no-reflow and hence persistently low MBF in the reperfused LAD territory which contained a mixture of viable and non-viable tissue. CT perfusion measurement of MBF was accurate and correlated well with histology and microspheres measurements.

  12. Molecular and Cellular Basis of Microvascular Perfusion Deficits Induced by Clostridium perfringens and Clostridium septicum

    PubMed Central

    Hickey, Michael J.; Kwan, Rain Y. Q.; Awad, Milena M.; Kennedy, Catherine L.; Young, Lauren F.; Hall, Pam; Cordner, Leanne M.; Lyras, Dena; Emmins, John J.; Rood, Julian I.

    2008-01-01

    Reduced tissue perfusion leading to tissue ischemia is a central component of the pathogenesis of myonecrosis caused by Clostridium perfringens. The C. perfringens α-toxin has been shown capable of inducing these changes, but its potential synergy with perfringolysin O (θ-toxin) is less well understood. Similarly, Clostridium septicum is a highly virulent causative agent of spontaneous gas gangrene, but its effect on the microcirculation has not been examined. Therefore, the aim of this study was to use intravital microscopy to examine the effects of C. perfringens and C. septicum on the functional microcirculation, coupled with the use of isogenic toxin mutants to elucidate the role of particular toxins in the resultant microvascular perfusion deficits. This study represents the first time this integrated approach has been used in the analysis of the pathological response to clostridial toxins. Culture supernatants from wild-type C. perfringens induced extensive cell death within 30 min, as assessed by in vivo uptake of propidium iodide. Furthermore, significant reductions in capillary perfusion were observed within 60 min. Depletion of either platelets or neutrophils reduced the alteration in perfusion, consistent with a role for these blood-borne cells in obstructing perfusion. In addition, mutation of either the α-toxin or perfringolysin O structural genes attenuated the reduction in perfusion, a process that was reversed by genetic complementation. C. septicum also induced a marked reduction in perfusion, with the degree of microvascular compromise correlating with the level of the C. septicum α-toxin. Together, these data indicate that as a result of its ability to produce α-toxin and perfringolysin O, C. perfringens rapidly induces irreversible cellular injury and a marked reduction in microvascular perfusion. Since C. septicum induces a similar reduction in microvascular perfusion, it is postulated that this function is central to the pathogenesis of

  13. Mucosal Immunity and Candida albicans Infection

    PubMed Central

    Moyes, David L.; Naglik, Julian R.

    2011-01-01

    Interactions between mucosal surfaces and microbial microbiota are key to host defense, health, and disease. These surfaces are exposed to high numbers of microbes and must be capable of distinguishing between those that are beneficial or avirulent and those that will invade and cause disease. Our understanding of the mechanisms involved in these discriminatory processes has recently begun to expand as new studies bring to light the importance of epithelial cells and novel immune cell subsets such as Th17 T cells in these processes. Elucidating how these mechanisms function will improve our understanding of many diverse diseases and improve our ability to treat patients suffering from these conditions. In our voyage to discover these mechanisms, mucosal interactions with opportunistic commensal organisms such as the fungus Candida albicans provide insights that are invaluable. Here, we review current knowledge of the interactions between C. albicans and epithelial surfaces and how this may shape our understanding of microbial-mucosal interactions. PMID:21776285

  14. C. albicans Colonization of Human Mucosal Surfaces

    PubMed Central

    Southern, Peter; Horbul, Julie; Maher, Diane; Davis, Dana A.

    2008-01-01

    Background Candida albicans is a low level commensal organism in normal human populations with the continuous potential to expand and cause a spectrum of clinical conditions. Methodology/Principal Findings Using ex vivo human organ cultures and populations of primary human cells, we have developed several related experimental systems to examine early-stage interactions between C. albicans and mucosal surfaces. Experiments have been conducted both with exogenously added C. albicans and with overtly normal human mucosal surfaces supporting pre-existing infections with natural isolates of Candida. Under different culture conditions, we have demonstrated the formation of C. albicans colonies on human target cells and filament formation, equivalent to tissue invasion. Conclusions/Significance These organ culture systems provide a valuable new resource to examine the molecular and cellular basis for Candida colonization of human mucosal surfaces. PMID:18446191

  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.

  16. Patient directed perfusion pressure on bypass, an analogy from electrical engineering--a new concept.

    PubMed

    Warwick, Richard; Poole, Robert; Palmer, Kenneth; Johnson, Ian; Poullis, Michael

    2010-03-01

    Organ ischemia, particularly mesenteric and renal, can occur despite a seemingly adequate perfusion flow and pressure during a period of cardiopulmonary bypass. The blood pressure to run bypass at remains a contentious issue. We present the concept that perfusion pressure during cardiopulmonary bypass should be patient specific, depending on an individual's resting pre-procedural blood pressure. Four simulated arterial traces with variable morphology, but identical systolic and diastolic blood pressures, were analyzed to calculate the medical mean, arithmetic mean, and root mean square of the blood pressure tracing. Using the standard medical formula for calculation of mean blood pressure, you can potentially underestimate perfusion pressure by 12 mmHg in a normotensive subject. The root mean square pressure calculates the equivalent non pulsatile pressure that will deliver the same hydraulic power to the circulation as its pulsatile equivalent. Patient specific perfusion pressures, calculated via root mean square may potentially help reduce the incidence of organ ischemia during cardiopulmonary bypass. Clinical trials are needed to confirm or refute this concept.

  17. Patient Directed Perfusion Pressure on Bypass, an Analogy from Electrical Engineering—A New Concept

    PubMed Central

    Warwick, Richard; Poole, Robert; Palmer, Kenneth; Johnson, Ian; Poullis, Michael

    2010-01-01

    Abstract: Organ ischemia, particularly mesenteric and renal, can occur despite a seemingly adequate perfusion flow and pressure during a period of cardiopulmonary bypass. The blood pressure to run bypass at remains a contentious issue. We present the concept that perfusion pressure during cardiopulmonary bypass should be patient specific, depending on an individual’s resting pre-procedural blood pressure. Four simulated arterial traces with variable morphology, but identical systolic and diastolic blood pressures, were analyzed to calculate the medical mean, arithmetic mean, and root mean square of the blood pressure tracing. Using the standard medical formula for calculation of mean blood pressure, you can potentially underestimate perfusion pressure by 12 mmHg in a normotensive subject. The root mean square pressure calculates the equivalent non pulsatile pressure that will deliver the same hydraulic power to the circulation as its pulsatile equivalent. Patient specific perfusion pressures, calculated via root mean square may potentially help reduce the incidence of organ ischemia during cardiopulmonary bypass. Clinical trials are needed to confirm or refute this concept. PMID:20437793

  18. 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.

  19. Ultrasound perfusion analysis combining bolus-tracking and burst-replenishment.

    PubMed

    Jirik, Radovan; Nylund, Kim; Gilja, Odd H; Mezl, Martin; Harabis, Vratislav; Kolar, Radim; Standara, Michal; Taxt, Torfinn

    2013-02-01

    A new signal model and processing method for quantitative ultrasound perfusion analysis is presented, called bolus-and-burst. The method has the potential to provide absolute values of blood flow, blood volume, and mean transit time. Furthermore, it provides an estimate of the local arterial input function which characterizes the arterial tree, allowing accurate estimation of the bolus arrival time. The method combines two approaches to ultrasound perfusion analysis: bolus-tracking and burst-replenishment. A pharmacokinetic model based on the concept of arterial input functions and tissue residue functions is used to model both the bolus and replenishment parts of the recording. The pharmacokinetic model is fitted to the data using blind deconvolution. A preliminary assessment of the new perfusion-analysis method is presented on clinical recordings.

  20. Regulation of intestinal blood flow.

    PubMed

    Matheson, P J; Wilson, M A; Garrison, R N

    2000-09-01

    The gastrointestinal system anatomically is positioned to perform two distinct functions: to digest and absorb ingested nutrients and to sustain barrier function to prevent transepithelial migration of bacteria and antigens. Alterations in these basic functions contribute to a variety of clinical scenarios. These primary functions intrinsically require splanchnic blood flow at both the macrovascular and microvascular levels of perfusion. Therefore, a greater understanding of the mechanisms that regulate intestinal vascular perfusion in the normal state and during pathophysiological conditions would be beneficial. The purpose of this review is to summarize the current understanding regarding the regulatory mechanisms of intestinal blood flow in fasted and fed conditions and during pathological stress.

  1. Contributions of Neutrophils to Resolution of Mucosal Inflammation

    PubMed Central

    Colgan, Sean P.; Ehrentraut, Stefan F.; Glover, Louise E.; Kominsky, Douglas J.; Campbell, Eric L.

    2014-01-01

    Neutrophil (PMN) recruitment from the blood stream into surrounding tissues involves a regulated series of events central to acute responses in host defense. Accumulation of PMN within mucosal tissues have historically been considered pathognomonic features of both acute and chronic inflammatory conditions. Historically PMNs have been deemed necessary but detrimental when recruited, given the potential for tissue damage that results from a variety of mechanisms. Recent work, however, has altered our preconcieved notions of PMN contributions to inflammatory processes. In particular, significant evidence implicates a central role for the PMN in triggering inflammatory resolution. Such mechanisms involve both metabolic and biochemical crosstalk pathways during the intimate interactions of PMN with other cell types at inflammatory sites. Here, we highlight several recent examples of how PMN coordinate the resolution of ongoing inflammation, with a particular focus on the gastrointestinal mucosa. PMID:22968707

  2. Role of oxygen radicals and neutrophils in hemorrhagic shock-induced gastric mucosal injury

    SciTech Connect

    Smith, S.M.

    1987-01-01

    The role of oxygen radicals and neutrophils was examined in ischemia-reperfusion injury to the gastric mucosa in male Sprague-Dawley rats. Gastric mucosal clearance of /sup 51/Cr-labelled red blood cells was measured during a 30 minute control period, 30 minute ischemic period, and a 60 minute reperfusion period. In untreated rats, a dramatic rise in the leakage of /sup 51/Cr-labeled red blood cells into the gastric lumen was observed only during the reperfusion period. Ischemia-reperfusion was also associated with the formation of both grossly visible and histologically demonstrable mucosal lesions. Pretreatment with dimethylsulfoxide or deferoxamine largely prevented gastric bleeding and gross lesion formation, indicating that the hydroxyl radical, generated by the iron-catalyzed Haber-Weiss reaction, is the primary cytotoxic oxygen species involved in ischemia-reperfusion injury.

  3. Concomitant early mucosal and cutaneous leishmaniasis in Brazil.

    PubMed

    Boaventura, Viviane S; Cafe, Virginia; Costa, Jackson; Oliveira, Fabiano; Bafica, Andre; Rosato, Andrea; de Freitas, Luiz A R; Brodskyn, Claudia; Barral-Netto, Manoel; Barral, Aldina

    2006-08-01

    Mucosal leishmaniasis (ML) is often clinically silent until reaching a highly advanced state. In this prospective study, 6 of 220 patients with early cutaneous leishmaniasis were diagnosed with mucosal involvement by otorhinolaryngological examination (a rate similar to the reported rate of late ML). Detection of early ML may represent an important strategy in preventing severe mucosal destruction in human leishmaniasis.

  4. Assessment of the intrapulmonary ventilation-perfusion distribution after the Fontan procedure for complex cardiac anomalies: Relation to pulmonary hemodynamics

    SciTech Connect

    Matsushita, T.; Matsuda, H.; Ogawa, M.; Ohno, K.; Sano, T.; Nakano, S.; Shimazaki, Y.; Nakahara, K.; Arisawa, J.; Kozuka, T. )

    1990-03-15

    In 12 patients who underwent the Fontan procedure for complex cardiac anomalies, lung scanning with xenon-133 was performed to assess the intrapulmonary ventilation-perfusion distribution, and comparison was made with a control group. All data were then analyzed in relation to either pre- or postoperative pulmonary hemodynamic data. In ventilation scans, the intrapulmonary distribution in the right lung was almost normal. In perfusion scans, an abnormal increased upper to lower lobe perfusion ratio greater than the normal value found in the control group was noted in seven patients (58.3%). There was a significant correlation (p less than 0.02) between the upper to lower lobe perfusion ratio and postoperative pulmonary vascular resistance. Furthermore, this perfusion ratio correlated inversely with the preoperative (p less than 0.005) and postoperative (p less than 0.02) right pulmonary artery area index, defined as the ratio of cross-sectional area to the normal value. Of five patients with less than 90% arterial oxygen saturation, four showed an abnormal distribution of pulmonary blood flow greater than the normal perfusion ratio. No patient had evidence of a pulmonary arteriovenous fistula by the echocardiographic contrast study. These results suggest that abnormal distribution of pulmonary blood flow to the upper lung segment may develop in patients after the Fontan procedure, and that insufficient size of the pulmonary artery before operation and the consequent postoperative elevation of pulmonary vascular resistance may be responsible for this perfusion abnormality.

  5. 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.

  6. Mucosal melanoma of the head and neck.

    PubMed

    Ascierto, Paolo Antonio; Accorona, Remo; Botti, Gerardo; Farina, Davide; Fossati, Piero; Gatta, Gemma; Gogas, Helen; Lombardi, Davide; Maroldi, Roberto; Nicolai, Piero; Ravanelli, Marco; Vanella, Vito

    2017-04-01

    Mucosal melanoma of the head and neck is a very rare and aggressive malignancy with a very poor prognosis. The nasal cavity, paranasal sinuses, and oral cavity are the most common locations. One-, 3- and 5-year survival rates between 2000 and 2007 were 63%, 30% and 20%, respectively. Cigarette smoking seems to be a risk factor even though the evidence for this is very low. Clinical signs and symptoms are usually nonspecific. While surgery is considered the mainstay of treatment for most mucosal melanomas of the head and neck region, radiotherapy has a role in local control of the disease after surgery. Many new treatment options in the last years, in particular targeted therapies (i.e. inhibitors of c-KIT, NRAS/MEK or BRAF) and immunotherapies (anti CTLA-4 and anti PD-1/PD-L1 antibodies), have changed the history of cutaneous melanoma. Despite the different biology, mucosal melanoma is currently treated in the same way as cutaneous melanoma; however, patients with mucosal melanoma were excluded from the majority of recent clinical trials. Recent molecular findings offer new hope for the development of more effective systemic therapy.

  7. Characterization of Mucosal Candida albicans Biofilms

    PubMed Central

    Dongari-Bagtzoglou, Anna; Kashleva, Helena; Dwivedi, Prabhat; Diaz, Patricia; Vasilakos, John

    2009-01-01

    C. albicans triggers recurrent infections of the alimentary tract mucosa that result from biofilm growth. Although the ability of C. albicans to form a biofilm on abiotic surfaces has been well documented in recent years, no information exists on biofilms that form directly on mucosal surfaces. The objectives of this study were to characterize the structure and composition of Candida biofilms forming on the oral mucosa. We found that oral Candida biofilms consist of yeast, hyphae, and commensal bacteria, with keratin dispersed in the intercellular spaces. Neutrophils migrate through the oral mucosa and form nests within the biofilm mass. The cell wall polysaccharide β-glucan is exposed during mucosal biofilm growth and is more uniformly present on the surface of biofilm organisms invading the oral mucosa. We conclude that C. albicans forms complex mucosal biofilms consisting of both commensal bacterial flora and host components. These discoveries are important since they can prompt a shift of focus for current research in investigating the role of Candida-bacterial interactions in the pathogenesis of mucosal infections as well as the role of β-glucan mediated signaling in the host response. PMID:19956771

  8. The paradoxical vascular interactions between endothelin-1 and calcitonin gene-related peptide in the rat gastric mucosal microcirculation.

    PubMed Central

    Lopez-Belmonte, J.; Whittle, B. J.

    1993-01-01

    1. The interactions between local intra-arterial infusion of endothelin-1 (ET-1) and rat alpha-calcitonin gene-related peptide (alpha-CGRP) on gastric mucosal damage and blood flow have been investigated in the pentobarbitone-anaesthetized rat. 2. Close-arterial infusion of ET-1 (2-200 pmol kg-1 min-1) induced a significant and dose-dependent increase in gastric mucosal haemorrhagic injury. 3. Close-arterial infusion of the higher doses of ET-1 (100 and 200 pmol kg-1 min-1) resulted in a biphasic effect on mucosal blood flow, as determined by laser Doppler flowmetry (LDF). This consisted of an initial transient increase followed by a pronounced and sustained fall in LDF. 4. Local microvascular constriction may thus contribute to the mechanisms underlying the gastric injury induced by these higher doses of ET-1. 5. However, close-arterial infusion of lower doses of ET-1 (2-50 pmol kg-1 min-1), that also provoked substantial mucosal damage, induced only a sustained and significant mucosal hyperaemia, which may be secondary to microvascular injury. 6. Concurrent dose-arterial administration of rat alpha-CGRP (50 pmol kg-1 min-1) significantly inhibited the extent of gastric mucosal injury induced by ET-1 (5 pmol kg-1 min-1). 7. Furthermore, concurrent close-arterial infusion of this dose of alpha-CGRP, which itself increased mucosal LDF, significantly inhibited the hyperaemic response induced by close-arterial infusion of ET-1 (5 pmol kg-1 min-1).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8220913

  9. Ventilation and perfusion magnetic resonance imaging of the lung

    PubMed Central

    Bauman, Grzegorz; Eichinger, Monika

    2012-01-01

    Summary A close interaction between the respiratory pump, pulmonary parenchyma and blood circulation is essential for a normal lung function. Many pulmonary diseases present, especially in their initial phase, a variable regional impairment of ventilation and perfusion. In the last decades various techniques have been established to measure the lung function. Besides the global pulmonary function tests (PFTs) imaging techniques gained increasing importance to detect local variations in lung function, especially for ventilation and perfusion assessment. Imaging modalities allow for a deeper regional insight into pathophysiological processes and enable improved planning of invasive procedures. In contrast to computed tomography (CT) and the nuclear medicine techniques, magnetic resonance imaging (MRI), as a radiation free imaging modality gained increasing importance since the early 1990 for the assessment of pulmonary function. The major inherent problems of lung tissue, namely the low proton density and the pulmonary and cardiac motion, were overcome in the last years by a constant progress in MR technology. Some MR techniques are still under development, a process which is driven by scientific questions regarding the physiology and pathophysiology of pulmonary diseases, as well as by the need for fast and robust clinically applicable imaging techniques as safe therapy monitoring tools. MRI can be considered a promising ionizing-free alternative to techniques like CT or nuclear medicine techniques for the evaluation of lung function. The goal of this article is to provide an overview on selected MRI techniques for the assessment of pulmonary ventilation and perfusion. PMID:22802864

  10. 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

  11. MR pulmonary angiography and perfusion imaging: recent advances.

    PubMed

    Hatabu, H

    1997-10-01

    Recent advances in MR pulmonary angiography and MR perfusion imaging are reviewed, focusing on two principal areas of technical development: (1) the availability of MR scanners equipped with enhanced gradient systems; and (2) new trends in MR angiography using gadolinium contrast agents or labeling of blood with an inversion recovery radiofrequency pulse in place of the more traditional methods using naturally flowing spins as the source of intravascular signal. These recent developments in MR have significant potential for clinical imaging of the pulmonary vasculature, particularly for the diagnosis of pulmonary embolism, and are now opening windows to functional MR imaging of the lung.

  12. Criteria for viability assessment of discarded human donor livers during ex vivo normothermic machine perfusion.

    PubMed

    Sutton, Michael E; op den Dries, Sanna; Karimian, Negin; Weeder, Pepijn D; de Boer, Marieke T; Wiersema-Buist, Janneke; Gouw, Annette S H; Leuvenink, Henri G D; Lisman, Ton; Porte, Robert J

    2014-01-01

    Although normothermic machine perfusion of donor livers may allow assessment of graft viability prior to transplantation, there are currently no data on what would be a good parameter of graft viability. To determine whether bile production is a suitable biomarker that can be used to discriminate viable from non-viable livers we have studied functional performance as well as biochemical and histological evidence of hepatobiliary injury during ex vivo normothermic machine perfusion of human donor livers. After a median duration of cold storage of 6.5 h, twelve extended criteria human donor livers that were declined for transplantation were ex vivo perfused for 6 h at 37 °C with an oxygenated solution based on red blood cells and plasma, using pressure controlled pulsatile perfusion of the hepatic artery and continuous portal perfusion. During perfusion, two patterns of bile flow were identified: (1) steadily increasing bile production, resulting in a cumulative output of ≥ 30 g after 6 h (high bile output group), and (2) a cumulative bile production <20 g in 6 h (low bile output group). Concentrations of transaminases and potassium in the perfusion fluid were significantly higher in the low bile output group, compared to the high bile output group. Biliary concentrations of bilirubin and bicarbonate were respectively 4 times and 2 times higher in the high bile output group. Livers in the low bile output group displayed more signs of hepatic necrosis and venous congestion, compared to the high bile output group. In conclusion, bile production could be an easily assessable biomarker of hepatic viability during ex vivo machine perfusion of human donor livers. It could potentially be used to identify extended criteria livers that are suitable for transplantation. These ex vivo findings need to be confirmed in a transplant experiment or a clinical trial.

  13. Association of frontal gray matter volume and cerebral perfusion in heroin addiction: a multimodal neuroimaging study.

    PubMed

    Denier, Niklaus; Schmidt, André; Gerber, Hana; Schmid, Otto; Riecher-Rössler, Anita; Wiesbeck, Gerhard A; Huber, Christian G; Lang, Undine E; Radue, Ernst-Wilhelm; Walter, Marc; Borgwardt, Stefan

    2013-01-01

    Structure and function are closely related in the healthy human brain. In patients with chronic heroin exposure, brain imaging studies have identified long-lasting changes in gray matter (GM) volume. More recently, we showed that acute application of heroin in dependent patients results in hypoperfusion of fronto-temporal areas compared with the placebo condition. However, the relationship between structural and cerebral blood flow (CBF) changes in heroin addiction has not yet been investigated. Moreover, it is not known whether there is any interaction between the chronic structural changes and the short and long-term effects on perfusion caused by heroin. Using a double-blind, within-subject design, heroin or placebo (saline) was administered to 14 heroin-dependent patients from a stable heroin-assisted treatment program, in order to observe acute short-term effects. Arterial spin labeling (ASL) was used to calculate perfusion quantification maps in both treatment conditions, while Voxel-Based Morphometry (VBM) was conducted to calculate regional GM density. VBM and ASL data were used to calculate homologous correlation fields by Biological Parametric Mapping (BPM) and a whole-brain Pearson r correlation. We correlated each perfusion condition (heroin and placebo) separately with a VBM sample that was identical for the two treatment conditions. It was assumed that heroin-associated perfusion is manifested in short-term effects, while placebo-associated perfusion is more related to long-term effects. In order to restrict our analyses to fronto-temporal regions, we used an explicit mask for our analyses. Correlation analyses revealed a significant positive correlation in frontal areas between GM and both perfusion conditions (heroin and placebo). Heroin-associated perfusion was also negatively correlated with GM in the inferior temporal gyrus on both hemispheres. These findings indicate that, in heroin-dependent patients, low GM volume is positively associated with

  14. Technetium myocardial perfusion agents: an introduction

    SciTech Connect

    English, R.J.; Kozlowski, J.; Tumeh, S.S.; Holman, B.L.

    1987-09-01

    This is the third in a series of four Continuing Education articles on developing radiopharmaceuticals. After reading this article, the reader should be able to: 1) understand the basic concepts of myocardial perfusion imaging; and 2) discuss the advantages of the technetium myocardial perfusion complexes over thallium-201.

  15. Luxury perfusion following anterior ischemic optic neuropathy.

    PubMed

    Friedland, S; Winterkorn, J M; Burde, R M

    1996-09-01

    We present five patients who developed luxury perfusion following anterior ischemic optic neuropathy in whom fluorescein angiography was misinterpreted as "capillary hemangioma" or neovascularization of the disc. In each case, the segment of disc hyperemia corresponded to a spared region of visual field. Luxury perfusion represents a reparative autoregulatory reaction to ischemia.

  16. 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

  17. Comparison of Regional Brain Perfusion Levels in Chronically Smoking and Non-Smoking Adults

    PubMed Central

    Durazzo, Timothy C.; Meyerhoff, Dieter J.; Murray, Donna E.

    2015-01-01

    Chronic cigarette smoking is associated with numerous abnormalities in brain neurobiology, but few studies specifically investigated the chronic effects of smoking (compared to the acute effects of smoking, nicotine administration, or nicotine withdrawal) on cerebral perfusion (i.e., blood flow). Predominately middle-aged male (47 ± 11 years of age) smokers (n = 34) and non-smokers (n = 27) were compared on regional cortical perfusion measured by continuous arterial spin labeling magnetic resonance studies at 4 Tesla. Smokers showed significantly lower perfusion than non-smokers in the bilateral medial and lateral orbitofrontal cortices, bilateral inferior parietal lobules, bilateral superior temporal gyri, left posterior cingulate, right isthmus of cingulate, and right supramarginal gyrus. Greater lifetime duration of smoking (adjusted for age) was related to lower perfusion in multiple brain regions. The results indicated smokers showed significant perfusion deficits in anterior cortical regions implicated in the development, progression, and maintenance of all addictive disorders. Smokers concurrently demonstrated reduced blood flow in posterior brain regions that show morphological and metabolic aberrations as well as elevated beta amyloid deposition demonstrated by those with early stage Alzheimer disease. The findings provide additional novel evidence of the adverse effects of cigarette smoking on the human brain. PMID:26193290

  18. 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)

  19. 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.

  20. Chromium absorption in the vascularly perfused rat intestine

    SciTech Connect

    Dowling, H.J.; Offenbacher, E.G.; Pi-Sunyer, F.X.

    1986-03-01

    The mechanism of chromium (Cr) absorption by the rat small intestine was investigated using a double perfusion technique wherein the luman of the small intestine and the vasculature supplying it were separately perfused. The intestinal perfusate (IP) was a nutrient-rich tissue culture medium (TCM) with added inorganic Cr and /sup 51/Cr. The vascular perfusate (VP) was a Krebs-Ringer bicarbonate solution (KRB) containing 4.7% dextran, 0.1% glucose and 5% human serum. Cr absorption was calculated by the amount of /sup 51/Cr detected in the VP. To determine the transport mechanism for Cr, its absorption into the VP was measured at various Cr concentrations of the IP ranging from 10-400 ppb CrCl/sub 3/. The amount of Cr absorbed into the blood rose linearly with the intestinal Cr concentration suggesting a process of simple diffusion. Manipulations of the VP and IP constituents were made to investigate their effects on Cr absorption. When serum was omitted from the VP, Cr adsorption was suppressed, suggesting that serum component(s) are necessary for optimal Cr absorption. When either of 2 plasma transport proteins (apo-transferrin, albumin) were added to the serum-free VP at physiological levels, Cr absorption returned to, but did not exceed, control levels. When the TCM was replaced with a KRB solution; Cr absorption was suppressed indicating that there are nutrient(s) of the TCM which facilitate Cr absorption. Further suppression occurred when a Cr concentration gradient opposing Cr absorption was created (IP at 100 ppb Cr, VP at 400 ppb Cr).

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

    PubMed

    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

    2016-02-01

    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.

  2. 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.

  3. 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

  4. [Compromized myocardial perfusion in arrhythmias (author's transl)].

    PubMed

    Simon, H; Neumann, G; Felix, R; Hedde, H; Schaede, A; Thurn, P; Winkler, C

    1977-09-15

    In 7 patients with arrhythmias of various origin the myocardial scintigram displayed either a diffuse or circumscript defect of the perfusion. The coronary arteriogram was normal in all patients. The localized defect of the perfusion in 2 patients was in the region of the upper part of the interventricular septum. Both had a left bundle brunch block. A correlation between the perfusion defect and the electrophysiological abnormality seems probable. The perfusion defect in one of the patients is most probably caused by a previous myocarditis followed by fibrous changes. In the other 6 patients the cause for the perfusion defect is not obvious. A history of myocarditis is missing. The presence of "small vessel disease" in those patients has however to be considered. Our results point to the relation between an abnormality of the microcirculation and arrhythmias in younger patients.

  5. Characterising the mucosal and systemic immune responses to experimental human hookworm infection.

    PubMed

    Gaze, Soraya; McSorley, Henry J; Daveson, James; Jones, Di; Bethony, Jeffrey M; Oliveira, Luciana M; Speare, Richard; McCarthy, James S; Engwerda, Christian R; Croese, John; Loukas, Alex

    2012-02-01

    The mucosal cytokine response of healthy humans to parasitic helminths has never been reported. We investigated the systemic and mucosal cytokine responses to hookworm infection in experimentally infected, previously hookworm naive individuals from non-endemic areas. We collected both peripheral blood and duodenal biopsies to assess the systemic immune response, as well as the response at the site of adult worm establishment. Our results show that experimental hookworm infection leads to a strong systemic and mucosal Th2 (IL-4, IL-5, IL-9 and IL-13) and regulatory (IL-10 and TGF-β) response, with some evidence of a Th1 (IFN-γ and IL-2) response. Despite upregulation after patency of both IL-15 and ALDH1A2, a known Th17-inducing combination in inflammatory diseases, we saw no evidence of a Th17 (IL-17) response. Moreover, we observed strong suppression of mucosal IL-23 and upregulation of IL-22 during established hookworm infection, suggesting a potential mechanism by which Th17 responses are suppressed, and highlighting the potential that hookworms and their secreted proteins offer as therapeutics for human inflammatory diseases.

  6. New generation of oral mucosal vaccines targeting dendritic cells

    PubMed Central

    Owen, Jennifer L.; Sahay, Bikash; Mohamadzadeh, Mansour

    2013-01-01

    As most infectious organisms gain entry at mucosal surfaces, there is a great deal of interest in developing vaccines that elicit effective mucosal immune responses against pathogen challenge. Targeted vaccination is one of the most effective methods available to prevent and control infectious diseases. Mucosal vaccines can offer lower costs, better accessibility, needle free delivery, and a higher capacity for mass immunizations during pandemics. Both local mucosal immunity and robust systemic responses can be achieved through mucosal vaccination. Recent progress in understanding the molecular and cellular components of the mucosal immune system have allowed for the development of a novel mucosal vaccine platform utilizing specific dendritic cell-targeting peptides and orally administered lactobacilli to elicit efficient antigen specific immune responses against infections, including B. anthracis in experimental models of disease. PMID:23835515

  7. New generation of oral mucosal vaccines targeting dendritic cells.

    PubMed

    Owen, Jennifer L; Sahay, Bikash; Mohamadzadeh, Mansour

    2013-12-01

    As most infectious organisms gain entry at mucosal surfaces, there is a great deal of interest in developing vaccines that elicit effective mucosal immune responses against pathogen challenge. Targeted vaccination is one of the most effective methods available to prevent and control infectious diseases. Mucosal vaccines can offer lower costs, better accessibility, needle free delivery, and a higher capacity for mass immunizations during pandemics. Both local mucosal immunity and robust systemic responses can be achieved through mucosal vaccination. Recent progress in understanding the molecular and cellular components of the mucosal immune system have allowed for the development of a novel mucosal vaccine platform utilizing specific dendritic cell-targeting peptides and orally administered lactobacilli to elicit efficient antigen specific immune responses against infections, including Bacillus anthracis in experimental models of disease.

  8. Quantitative Perfusion Analysis of First-Pass Contrast Enhancement Kinetics: Application to MRI of Myocardial Perfusion in Coronary Artery Disease

    PubMed Central

    Shah, Binita; Storey, Pippa; Iqbal, Sohah; Slater, James; Axel, Leon

    2016-01-01

    Purpose Perfusion analysis from first-pass contrast enhancement kinetics requires modeling tissue contrast exchange. This study presents a new approach for numerical implementation of the tissue homogeneity model, incorporating flexible distance steps along the capillary (NTHf). Methods The proposed NTHf model considers contrast exchange in fluid packets flowing along the capillary, incorporating flexible distance steps, thus allowing more efficient and stable calculations of the transit of tracer through the tissue. We prospectively studied 8 patients (62 ± 13 years old) with suspected CAD, who underwent first-pass perfusion CMR imaging at rest and stress prior to angiography. Myocardial blood flow (MBF) and myocardial perfusion reserve index (MPRI) were estimated using both the NTHf and the conventional adiabatic approximation of the TH models. Coronary artery lesions detected at angiography were clinically assigned to one of three categories of stenosis severity (‘insignificant’, ‘mild to moderate’ and ‘severe’) and related to corresponding myocardial territories. Results The mean MBF (ml/g/min) at rest/stress and MPRI were 0.80 ± 0.33/1.25 ± 0.45 and 1.68 ± 0.54 in the insignificant regions, 0.74 ± 0.21/1.09 ± 0.28 and 1.54 ± 0.46 in the mild to moderate regions, and 0.79 ± 0.28/0.63 ± 0.34 and 0.85 ± 0.48 in the severe regions, respectively. The correlation coefficients of MBFs at rest/stress and MPRI between the NTHf and AATH models were r = 0.97/0.93 and r = 0.91, respectively. Conclusions The proposed NTHf model allows efficient quantitative analysis of the transit of tracer through tissue, particularly at higher flow. Results of initial application to MRI of myocardial perfusion in CAD are encouraging. PMID:27583385

  9. Perfusion estimation using contrast enhanced three-dimensional subharmonic ultrasound imaging: an in vivo study

    PubMed Central

    Sridharan, Anush; Eisenbrey, John R.; Liu, Ji-Bin; Machado, Priscilla; Halldorsdottir, Valgerdur G.; Dave, Jaydev K.; Zhao, Hongjia; He, Yu; Park, Suhyun; Dianis, Scott; Wallace, Kirk; Thomenius, Kai E.; Forsberg, Flemming

    2013-01-01

    Objectives The ability to estimate tissue perfusion (in mL/min/g) in vivo using contrast-enhanced three-dimensional (3D) harmonic and subharmonic ultrasound imaging was investigated. Materials and Methods A Logiq 9 scanner (GE Healthcare, Milwaukee, WI) equipped with a 4D10L probe was modified to perform 3D harmonic imaging (HI; ftransmit = 5 MHz and freceive = 10 MHz) and subharmonic imaging (SHI; ftransmit= 5.8 MHz and freceive= 2.9 MHz). In vivo imaging was performed in the lower pole of both kidneys in five open-abdomen canines after injection of the ultrasound contrast agent (UCA) Definity (Lantheus Medical Imaging, N Billerica, MA). The canines received a 5 μL/kg bolus injection of Definity for HI and a 20 μL/kg bolus for SHI in triplicate for each kidney. Ultrasound data acquisition was started just prior to injection of UCA (in order to capture the wash-in) and continued until washout. A microvascular staining technique based on stable (non-radioactive) isotope-labeled microspheres (Biophysics Assay Laboratory Inc, Worcester, MA) was used to quantify the degree of perfusion in each kidney (the reference standard). Ligating a surgically exposed branch of the renal arteries induced lower perfusion rates. This was followed by additional contrast-enhanced imaging and microsphere injections to measure post-ligation perfusion. Slice data were extracted from the 3D ultrasound volumes and used to generate time-intensity curves off-line in the regions corresponding to the tissue samples used for microvascular staining. The mid-line plane was also selected from the 3D volume (as a quasi-2D image) and compared to the 3D imaging modes. Perfusion was estimated from the initial slope of the fractional blood volume uptake (for both HI and SHI) and compared to the reference standard using linear regression analysis. Results Both 3D HI and SHI were able to provide visualization of flow and, thus, perfusion in the kidneys. However, SHI provided near complete tissue

  10. The role of volume perfusion CT in the diagnosis of pathologies of the pancreas.

    PubMed

    Grözinger, G; Grözinger, A; Horger, M

    2014-12-01

    The review discusses the potential role of volume perfusion CT (VPCT) in the diagnosis and follow-up of different pathologies of the pancreas. VPCT enables a differentiation of different pancreatic tumors like adenocarcinoma or neuroendocrine tumors based on functional parameters like blood flow, blood volume and permeability. Furthermore, the article discusses the potential indications for VPCT imaging of inflammatory diseases of the pancreas such as acute or chronic pancreatitis and autoimmune pancreatitis.

  11. The asymmetric facial skin perfusion distribution of Bell's palsy discovered by laser speckle imaging technology.

    PubMed

    Cui, Han; Chen, Yi; Zhong, Weizheng; Yu, Haibo; Li, Zhifeng; He, Yuhai; Yu, Wenlong; Jin, Lei

    2016-01-01

    Bell's palsy is a kind of peripheral neural disease that cause abrupt onset of unilateral facial weakness. In the pathologic study, it was evidenced that ischemia of facial nerve at the affected side of face existed in Bell's palsy patients. Since the direction of facial nerve blood flow is primarily proximal to distal, facial skin microcirculation would also be affected after the onset of Bell's palsy. Therefore, monitoring the full area of facial skin microcirculation would help to identify the condition of Bell's palsy patients. In this study, a non-invasive, real time and full field imaging technology - laser speckle imaging (LSI) technology was applied for measuring facial skin blood perfusion distribution of Bell's palsy patients. 85 participants with different stage of Bell's palsy were included. Results showed that Bell's palsy patients' facial skin perfusion of affected side was lower than that of the normal side at the region of eyelid, and that the asymmetric distribution of the facial skin perfusion between two sides of eyelid is positively related to the stage of the disease (P <  0.001). During the recovery, the perfusion of affected side of eyelid was increasing to nearly the same with the normal side. This study was a novel application of LSI in evaluating the facial skin perfusion of Bell's palsy patients, and we discovered that the facial skin blood perfusion could reflect the stage of Bell's palsy, which suggested that microcirculation should be investigated in patients with this neurological deficit. It was also suggested LSI as potential diagnostic tool for Bell's palsy.

  12. Lowering Perfusate Temperature From 37°C to 32°C Diminishes Function in a Porcine Model of Ex Vivo Kidney Perfusion

    PubMed Central

    Adams, Thomas D.; Patel, Meeta; Hosgood, Sarah A.; Nicholson, Michael L.

    2017-01-01

    Background Ex vivo perfusion (EVP) is a novel method of preservation. However, optimal perfusion conditions remain undetermined. Reducing the temperature of the perfusate to subnormothermia may be beneficial during EVP and improve early graft function. The aim of this study was to investigate whether subnormothermia would influence the conditioning effect of EVP when compared with normothermic perfusion, and standard cold static storage (CS). Methods Porcine kidneys underwent static CS for 23 hours followed by 1 hour of EVP using leukocyte-depleted blood at a mean temperature of 32°C or 37°C. After this, kidneys were reperfused with whole autologous blood at 37°C for 3 hours to assess renal function and injury. These were compared with a control group that underwent 24 hours CS. Results During EVP, kidneys perfused at 37°C had a higher level of renal blood flow and oxygen consumption compared with EVP at 32°C (P = 0.001, 0.002). During reperfusion, 32°C EVP kidneys had lower creatinine clearance and urine output than control (P = 0.023, 0.011) and a higher fractional excretion of sodium, serum potassium, and serum aspartate transaminase than 37°C EVP kidneys (P = 0.01, 0.023, 0.009). Conclusions Tubular and renal functions were better preserved by a near-physiological temperature of 37°C during 1 hour of EVP, when compared to EVP at 32°C or cold storage. PMID:28361124

  13. Neonatal aortic arch hemodynamics and perfusion during cardiopulmonary bypass.

    PubMed

    Pekkan, Kerem; Dur, Onur; Sundareswaran, Kartik; Kanter, Kirk; Fogel, Mark; Yoganathan, Ajit; Undar, Akif

    2008-12-01

    The objective of this study is to quantify the detailed three-dimensional (3D) pulsatile hemodynamics, mechanical loading, and perfusion characteristics of a patient-specific neonatal aortic arch during cardiopulmonary bypass (CPB). The 3D cardiac magnetic resonance imaging (MRI) reconstruction of a pediatric patient with a normal aortic arch is modified based on clinical literature to represent the neonatal morphology and flow conditions. The anatomical dimensions are verified from several literature sources. The CPB is created virtually in the computer by clamping the ascending aorta and inserting the computer-aided design model of the 10 Fr tapered generic cannula. Pulsatile (130 bpm) 3D blood flow velocities and pressures are computed using the commercial computational fluid dynamics (CFD) software. Second order accurate CFD settings are validated against particle image velocimetry experiments in an earlier study with a complex cardiovascular unsteady benchmark. CFD results in this manuscript are further compared with the in vivo physiological CPB pressure waveforms and demonstrated excellent agreement. Cannula inlet flow waveforms are measured from in vivo PC-MRI and 3 kg piglet neonatal animal model physiological experiments, distributed equally between the head-neck vessels and the descending aorta. Neonatal 3D aortic hemodynamics is also compared with that of the pediatric and fetal aortic stages. Detailed 3D flow fields, blood damage, wall shear stress (WSS), pressure drop, perfusion, and hemodynamic parameters describing the pulsatile energetics are calculated for both the physiological neonatal aorta and for the CPB aorta assembly. The primary flow structure is the high-speed canulla jet flow (approximately 3.0 m/s at peak flow), which eventually stagnates at the anterior aortic arch wall and low velocity flow in the cross-clamp pouch. These structures contributed to the reduced flow pulsatility (85%), increased WSS (50%), power loss (28%), and blood

  14. The Role of B7 Ligand Interactions During an In Vivo Mucosal Immune Response

    DTIC Science & Technology

    1998-07-22

    cell expansio~ elevated blood eosinophils ~and increased intestinal mucosal mast cells. Similarly, both Abs blocked MLN and Peyer’s Patch’s patch cytokine...29 I. <:elliabeling and analysis 29 J. ImmllDohistologica1 analysis 30 K. Quantitation ofserum immunoglobulins 31 L. Eosinophil counts 31 M...44 Figure S. The combination ofanti-B7-1 and anti-B7-2 mAbs treatment is required to inhibit elevations in intestinal MMC and blood eosinophils on day

  15. 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.

  16. Luxury perfusion syndrome in cerebral vascular disease evaluated with technetium-99m HM-PAO.

    PubMed

    Spreafico, G; Cammelli, F; Gadola, G; Freschi, R; Zancaner, F

    1987-03-01

    A recently developed Tc-99m radiocompound, hexamethylpropyleneamine oxime (Tc-99m HM-PAO), exhibits favorable properties for regional cerebral blood flow study in man. The authors present a case of luxury perfusion syndrome observed in a 72-year-old patient with acute stroke and a right-sided hemiplegia, documented by planar scintigraphy and SPECT study in correlation with CT scan. The metabolic basis of this phenomenon is discussed and the usefulness of assessing regional brain perfusion by Tc-99m HM-PAO with conventional nuclear medicine equipment is underlined.

  17. Perfusion Imaging with a Freely Diffusible Hyperpolarized Contrast Agent

    PubMed Central

    Grant, Aaron K.; Vinogradov, Elena; Wang, Xiaoen; Lenkinski, Robert E.; Alsop, David C.

    2011-01-01

    Contrast agents that can diffuse freely into or within tissue have numerous attractive features for perfusion imaging. Here we present preliminary data illustrating the suitability of hyperpolarized 13C labeled 2-methylpropan-2-ol (also known as dimethylethanol, tertiary butyl alcohol and tert-butanol) as a freely diffusible contrast agent for magnetic resonance perfusion imaging. Dynamic 13C images acquired in rat brain with a balanced steady-state free precession (bSSFP) sequence following administration of hyperpolarized 2-methylpropan-2-ol show that this agent can be imaged with 2–4s temporal resolution, 2mm slice thickness, and 700 micron in-plane resolution while retaining adequate signal-to-noise ratio. 13C relaxation measurements on 2-methylpropan-2-ol in blood at 9.4T yield T1=46±4s and T2=0.55±0.03s. In the rat brain at 4.7T, analysis of the temporal dynamics of the bSSFP image intensity in tissue and venous blood indicate that 2-methylpropan-2-ol has a T2 of roughly 2–4s and a T1 of 43±24s. In addition, the images indicate that 2-methylpropan-2-ol is freely diffusible in brain and hence has a long residence time in tissue; this in turn makes it possible to image the agent continuously for tens of seconds. These characteristics show that 2-methylpropan-2-ol is a promising agent for robust and quantitative perfusion imaging in the brain and body. PMID:21432901

  18. Peripheral Arterial Disease Assessment Wall, Perfusion, and Spectroscopy

    PubMed Central

    Kramer, Christopher M.

    2010-01-01

    Introduction Peripheral arterial disease (PAD) is characterized by lower limb arterial obstruction due to atherosclerosis and is increasingly common. Presently used methods for diagnosis and follow-up as well as for assessment of novel therapies are limited. Materials and Methods Three distinct magnetic resonance examinations were developed. The first was high-resolution black-blood atherosclerotic plaque imaging of the superficial femoral artery using a surface coil and flow saturation. Second, first-pass contrast-enhanced dual-contrast perfusion imaging of the calf muscle was performed at peak exercise using a magnetic resonance (MR)–compatible pedal ergometer. Lastly, 31P MR spectroscopy was also performed at peak exercise to measure phosphocreatine (PCr) recovery kinetics. Results Seventeen patients (age, 63 ± 10 yrs) with mild to moderate PAD were studied with black-blood atherosclerotic plaque imaging. Mean atherosclerotic plaque volume measured was 7.27 ± 3.73 cm3. Eleven patients (age, 61 ± 11 yrs) with mild to moderate symptomatic PAD and 22 normal control subjects were studied with first-pass contrast-enhanced perfusion imaging. Perfusion index was stepwise increased from patients to normal subjects with matched workload to normal subjects at maximal exercise. For PCr recovery kinetics, 20 patients with mild to moderate PAD and 14 controls were studied. The median recovery time constant of PCr was 34.7 seconds in the controls and 91.0 seconds in the PAD patients (P < 0.0001). Conclusions Three distinct MR examinations of different aspects of peripheral arterial disease have been developed and tested and shown to differentiate patients with mild to moderate PAD from normal controls. Taken together, these tests are potential quantitative end points for clinical trials of novel therapies in PAD. PMID:18025990

  19. Stability of radiomic features in CT perfusion maps.

    PubMed

    Bogowicz, M; Riesterer, O; Bundschuh, R A; Veit-Haibach, P; Hüllner, M; Studer, G; Stieb, S; Glatz, S; Pruschy, M; Guckenberger, M; Tanadini-Lang, S

    2016-12-21

    This study aimed to identify a set of stable radiomic parameters in CT perfusion (CTP) maps with respect to CTP calculation factors and image discretization, as an input for future prognostic models for local tumor response to chemo-radiotherapy. Pre-treatment CTP images of eleven patients with oropharyngeal carcinoma and eleven patients with non-small cell lung cancer (NSCLC) were analyzed. 315 radiomic parameters were studied per perfusion map (blood volume, blood flow and mean transit time). Radiomics robustness was investigated regarding the potentially standardizable (image discretization method, Hounsfield unit (HU) threshold, voxel size and temporal resolution) and non-standardizable (artery contouring and noise threshold) perfusion calculation factors using the intraclass correlation (ICC). To gain added value for our model radiomic parameters correlated with tumor volume, a well-known predictive factor for local tumor response to chemo-radiotherapy, were excluded from the analysis. The remaining stable radiomic parameters were grouped according to inter-parameter Spearman correlations and for each group the parameter with the highest ICC was included in the final set. The acceptance level was 0.9 and 0.7 for the ICC and correlation, respectively. The image discretization method using fixed number of bins or fixed intervals gave a similar number of stable radiomic parameters (around 40%). The potentially standardizable factors introduced more variability into radiomic parameters than the non-standardizable ones with 56-98% and 43-58% instability rates, respectively. The highest variability was observed for voxel size (instability rate  >97% for both patient cohorts). Without standardization of CTP calculation factors none of the studied radiomic parameters were stable. After standardization with respect to non-standardizable factors ten radiomic parameters were stable for both patient cohorts after correction for inter-parameter correlations. Voxel size

  20. Stability of radiomic features in CT perfusion maps

    NASA Astrophysics Data System (ADS)

    Bogowicz, M.; Riesterer, O.; Bundschuh, R. A.; Veit-Haibach, P.; Hüllner, M.; Studer, G.; Stieb, S.; Glatz, S.; Pruschy, M.; Guckenberger, M.; Tanadini-Lang, S.

    2016-12-01

    This study aimed to identify a set of stable radiomic parameters in CT perfusion (CTP) maps with respect to CTP calculation factors and image discretization, as an input for future prognostic models for local tumor response to chemo-radiotherapy. Pre-treatment CTP images of eleven patients with oropharyngeal carcinoma and eleven patients with non-small cell lung cancer (NSCLC) were analyzed. 315 radiomic parameters were studied per perfusion map (blood volume, blood flow and mean transit time). Radiomics robustness was investigated regarding the potentially standardizable (image discretization method, Hounsfield unit (HU) threshold, voxel size and temporal resolution) and non-standardizable (artery contouring and noise threshold) perfusion calculation factors using the intraclass correlation (ICC). To gain added value for our model radiomic parameters correlated with tumor volume, a well-known predictive factor for local tumor response to chemo-radiotherapy, were excluded from the analysis. The remaining stable radiomic parameters were grouped according to inter-parameter Spearman correlations and for each group the parameter with the highest ICC was included in the final set. The acceptance level was 0.9 and 0.7 for the ICC and correlation, respectively. The image discretization method using fixed number of bins or fixed intervals gave a similar number of stable radiomic parameters (around 40%). The potentially standardizable factors introduced more variability into radiomic parameters than the non-standardizable ones with 56-98% and 43-58% instability rates, respectively. The highest variability was observed for voxel size (instability rate  >97% for both patient cohorts). Without standardization of CTP calculation factors none of the studied radiomic parameters were stable. After standardization with respect to non-standardizable factors ten radiomic parameters were stable for both patient cohorts after correction for inter-parameter correlations. Voxel size

  1. CpG oligodeoxynucleotides as mucosal adjuvants

    PubMed Central

    Iho, Sumiko; Maeyama, Jun-ichi; Suzuki, Fumiko

    2015-01-01

    Bacterial DNA comprising palindromic sequences and containing unmethylated CpG is recognized by toll-like receptor 9 of plasmacytoid dendritic cells (pDCs) and induces the production of interferon-α and chemokines, leading to the activation of a Th1 immune response. Therefore, synthetic equivalents of bacterial DNA (CpG oligodeoxynucleotides) have been developed for clinical applications. They are usually phosphorothioated for in vivo use; this approach also leads to adverse effects as reported in mouse models.Mucosal vaccines that induce both mucosal and systemic immunity received substantial attention in recent years. For their development, phosphodiester-linked oligodeoxynucleotides, including the sequence of a palindromic CpG DNA may be advantageous as adjuvants because their target pDCs are present right there, in the mucosa of the vaccination site. In addition, the probability of adverse effects is believed to be low. Here, we review the discovery of such CpG oligodeoxynucleotides and their possible use as mucosal adjuvants. PMID:25751765

  2. Hitting the mucosal road in tolerance induction.

    PubMed

    Wiedermann, Ursula

    2009-01-01

    Within the last decades a dramatic increase in allergic diseases has been recognized in the Westernized societies, leading to the fact that meanwhile 25-30% of the population is afflicted by allergic disorders. Besides a hereditary disposition, other factors, including a reduced microbial contact early in life or changes in nutrition, might also have influenced this epidemiological development. So far the only causative treatment against type-I allergies is specific immunotherapy. In young and monosensitized patients this treatment is highly efficacious, while there are clear limitations in older or multisensitized patients. Allergy research therefore aims at establishing new and more efficacious treatment strategies in prophylactic as well as therapeutic settings. Our research programs focus on the development of novel allergy vaccines based on the induction of mucosal tolerance. In different mouse models of respiratory allergy mucosal treatment with genetically engineered allergen constructs proved to prevent the development of allergic mono- and multisensitivities. The additional use of mucosal adjuvants seems particularly important to improve therapeutic treatment approaches. Recent studies on the inverse relation of certain parasite infections and the development of allergy prompted us to search for selected parasitic molecules with immunosuppressive properties as potential adjuvant systems for novel allergy vaccines. An overview of our recent studies will be given.

  3. Dermoscopic appearance of an amelanotic mucosal melanoma

    PubMed Central

    Blum, Andreas; Beck-Zoul, Ulrike; Held, Laura; Haase, Sylvie

    2016-01-01

    Background Hypomelanotic or amelanotic melanomas are challenging to identify, especially at mucosal sites. The dermoscopic clues to the diagnosis of mucosal melanomas have been reported to be structureless zones with the presence of blue, gray, or white colors. Case A female in her seventies noted a new lesion on the inside of her right labia that first appeared two months prior. Her past medical history was significant for rheumatoid arthritis requiring ongoing treatment with methotrexate for 20 years and adalimumab for 10 years. After no response to two weeks of local treatment for suspected herpes simplex infection, her gynecologist performed a skin biopsy. Based on the histopathological diagnosis of an amelanotic melanoma (Breslow thickness of 1.3 mm) the patient was referred to dermatology for further assessment. Polarized dermoscopy revealed a distinct asymmetric, sharply demarcated homogenous white papule (4 × 5 mm) as well as polymorphous vessels. Conclusion Dermoscopy may aid in the diagnosis of amelanotic mucosal melanomas. Our case revealed a structureless white area and polymorphous vessels. Additional clues to the diagnosis were the advanced age of the patient and the clinical presentation of a new lesion. PMID:27867742

  4. 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.

  5. Age, gender, dentures and oral mucosal disorders.

    PubMed

    MacEntee, M I; Glick, N; Stolar, E

    1998-03-01

    The numbers of participants over 75 years of age in previous studies of oral health have not been sufficient to permit a full investigation of the influence of age on the mouth. In this study a disproportionate stratified random sample of 255 independent elders was selected from a list of urban voters to provide similar numbers of men and women in three age groups. The subjects were interviewed and examined, and nearly half of them had mucosal disorders. There was a significant (P < 0.05) association between mucosal lesions and the use of dentures and tobacco, whereas stomatitis, denture-related hyperplasia and angular cheilitis in particular were associated significantly with men and with the use of defective dentures. Logistic regression revealed that neither age alone nor the quality of dentures predispose to mucosal lesions, but that the odds of finding stomatitis, denture-related hyperplasia and angular cheilitis in particular increased about three-fold in denture-users, and almost doubled in men.

  6. Mucosal perforators from the facial artery.

    PubMed

    Coronel-Banda, Mauricio E; Serra-Renom, Jose M; Lorente, Marian; Larrea-Terán, Wendy P

    2014-07-01

    The cutaneous perforators of the facial artery have been well described, but to our knowledge the oral mucosal perforators have not. We studied 10 facial arteries from 10 hemifaces in 5 cadavers. The arteries were injected with latex, and we studied all perforators that extended from the facial artery and headed directly to the oral mucosa. The diameter and length of the facial artery and its mucosal perforators were measured and compared. We found 52 oral mucosal perforators in the 10 facial arteries injected with latex. Their mean (SD) diameter was 0.5 (0.2) mm and the mean (SD) number/facial artery was 5.2 (1.1). Their mean (SD) length was 16.4 (5.3) mm. Most of those to the cheek were localised between the branching-off points of the inferior and superior labial arteries. The facial artery has perforators to the oral mucosa of the cheek, most of them between the points at which the labial arteries emerge.

  7. DRAG REDUCING POLYMER ENCHANCES MICROVASCULAR PERFUSION IN THE TRAUMATIZED BRAIN WITH INTRACRANIAL HYPERTENSION

    PubMed Central

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

    2016-01-01

    SUMMARY Current treatments for traumatic brain injury (TBI) have not focused on improving microvascular perfusion. Drag-reducing polymers (DRP), linear, long-chain, blood soluble non-toxic macromolecules, may offer a new approach to improving cerebral perfusion by primary alteration of the fluid dynamic properties of blood. Nanomolar concentrations of DRP have been shown to improve hemodynamics in animal models of ischemic myocardium and limb, but have not yet been studied in the brain. Recently, we demonstrated that that DRP improved microvascular perfusion and tissue oxygenation in a normal rat brain. We hypothesized that DRP could restore microvascular perfusion in hypertensive brain after TBI. Using the in-vivo 2-photon laser scanning microscopy we examined the effect of DRP on microvascular blood flow and tissue oxygenation in hypertensive rat brains with and without TBI. DRP enhanced and restored capillary flow, decreased microvascular shunt flow and, as a result, reduced tissue hypoxia in both un-traumatized and traumatized rat brains at high ICP. Our study suggests that DRP could be an effective treatment for improving microvascular flow in brain ischemia caused by high ICP after TBI. PMID:27165871

  8. 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.

  9. Gut permeability and mucosal inflammation: bad, good or context dependent.

    PubMed

    Ahmad, R; Sorrell, M F; Batra, S K; Dhawan, P; Singh, A B

    2017-03-01

    Inflammatory bowel disease (IBD) is a multifactorial disease. A breach in the mucosal barrier, otherwise known as "leaky gut," is alleged to promote mucosal inflammation by intensifying immune activation. However, interaction between the luminal antigen and mucosal immune system is necessary to maintain mucosal homeostasis. Furthermore, manipulations leading to deregulated gut permeability have resulted in susceptibility in mice to colitis as well as to creating adaptive immunity. These findings implicate a complex but dynamic association between mucosal permeability and immune homeostasis; however, they also emphasize that compromised gut permeability alone may not be sufficient to induce colitis. Emerging evidence further supports the role(s) of proteins associated with the mucosal barrier in epithelial injury and repair: manipulations of associated proteins also modified epithelial differentiation, proliferation, and apoptosis. Taken together, the role of gut permeability and proteins associated in regulating mucosal inflammatory diseases appears to be more complex than previously thought. Herein, we review outcomes from recent mouse models where gut permeability was altered by direct and indirect effects of manipulating mucosal barrier-associated proteins, to highlight the significance of mucosal permeability and the non-barrier-related roles of these proteins in regulating chronic mucosal inflammatory conditions.

  10. 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.

  11. 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

  12. Genetically modified enterotoxigenic Escherichia coli vaccines induce mucosal immune responses without inflammation

    PubMed Central

    Daley, Alexandra; Randall, Roger; Darsley, Michael; Choudhry, Naheed; Thomas, Nicola; Sanderson, Ian R; Croft, Nick M; Kelly, Paul

    2007-01-01

    Objective Enterotoxigenic Escherichia coli (ETEC) is a major cause of acute diarrhoea in children in the developing world, in travellers and in the military. Safe, effective vaccines could reduce morbidity and mortality. As immunity to ETEC is strain specific, the ability to create vaccines in vitro which express multiple antigens would be desirable. It was hypothesised that three genetically attenuated ETEC strains, one with a genetic addition, would be immunogenic and safe, and they were evaluated in the first licensed UK release of genetically modified oral vaccines. Methods Phase 1 studies of safety and immunogenicity were carried out at a Teaching Hospital in London. Varying oral doses of any of three oral vaccines, or placebo, were administered to volunteers of both sexes (n = 98). Peripheral blood responses were measured as serum antibodies (IgG or IgA) by ELISA, antibody‐secreting cell (ASC) responses by enzyme‐linked immunospot (ELISPOT), and antibody in lymphocyte supernatant (ALS) by ELISA. Mucosal antibody secretion was measured by ELISA for specific IgG and IgA in whole gut lavage fluids (WGLFs). Results Significant mucosal IgA responses were obtained to colonisation factors CFA/I, CS1, CS2 and CS3, both when naturally expressed and when genetically inserted. Dose–response relationships were most clearly evident in the mucosal IgA in WGLF. Vaccines were well tolerated and did not elicit interleukin (IL) 8 or IL6 secretion in WGLF. Conclusions Genetically modified ETEC vaccines are safe and induce significant mucosal IgA responses to important colonisation factors. Mucosal IgA responses were clearly seen in WGLF, which is useful for evaluating oral vaccines. PMID:17566016

  13. Involvement of oxidative stress and mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in inflammatory bowel disease

    PubMed Central

    Tanida, Satoshi; Mizoshita, Tsutomu; Mizushima, Takashi; Sasaki, Makoto; Shimura, Takaya; Kamiya, Takeshi; Kataoka, Hiromi; Joh, Takashi

    2011-01-01

    The pathophysiology of inflammatory bowel disease involves excessive immune effects of inflammatory cells against gut microbes. In genetically predisposed individuals, these effects are considered to contribute to the initiation and perpetuation of mucosal injury. Oxidative stress is a fundamental tissue-destructive mechanisms that can occur due to the reactive oxygen species and reactive nitrogen metabolites which are released in abundance from numerous inflammatory cells that have extravasated from lymphatics and blood vessels to the lamina propria. This extravasation is mediated by interactions between adhesion molecules including mucosal addressin cell adhesion molecule-1 and vascular cell adhesion molecule-1 on the surface of lymphocytes or neutrophils and their ligands on endothelial cells. Thus, reactive oxygen species and adhesion molecules play an important role in the development of inflammatory bowel disease. The present review focuses on the involvement of oxidative stress and adhesion molecules, in particular mucosal addressin cell adhesion molecule-1, in inflammatory bowel disease. PMID:21373262

  14. 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

  15. The correlation of contrast-enhanced ultrasound and MRI perfusion quantitative analysis in rabbit VX2 liver cancer.

    PubMed

    Xiang, Zhiming; Liang, Qianwen; Liang, Changhong; Zhong, Guimian

    2014-12-01

    Our objective is to explore the value of liver cancer contrast-enhanced ultrasound (CEUS) and MRI perfusion quantitative analysis in liver cancer and the correlation between these two analysis methods. Rabbit VX2 liver cancer model was established in this study. CEUS was applied. Sono Vue was applied in rabbits by ear vein to dynamically observe and record the blood perfusion and changes in the process of VX2 liver cancer and surrounding tissue. MRI perfusion quantitative analysis was used to analyze the mean enhancement time and change law of maximal slope increasing, which were further compared with the pathological examination results. Quantitative indicators of liver cancer CEUS and MRI perfusion quantitative analysis were compared, and the correlation between them was analyzed by correlation analysis. Rabbit VX2 liver cancer model was successfully established. CEUS showed that time-intensity curve of rabbit VX2 liver cancer showed "fast in, fast out" model while MRI perfusion quantitative analysis showed that quantitative parameter MTE of tumor tissue increased and MSI decreased: the difference was statistically significant (P < 0.01). The diagnostic results of CEUS and MRI perfusion quantitative analysis were not significantly different (P > 0.05). However, the quantitative parameter of them were significantly positively correlated (P < 0.05). CEUS and MRI perfusion quantitative analysis can both dynamically monitor the liver cancer lesion and surrounding liver parenchyma, and the quantitative parameters of them are correlated. The combined application of both is of importance in early diagnosis of liver cancer.

  16. 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.

  17. 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.

  18. 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.

  19. Feasibility of quantitative lung perfusion by 4D CT imaging by a new dynamic-scanning protocol in an animal model

    NASA Astrophysics Data System (ADS)

    Wang, Yang; Goldin, Jonathan G.; Abtin, Fereidoun G.; Brown, Matt; McNitt-Gray, Mike

    2008-03-01

    The purpose of this study is to test a new dynamic Perfusion-CT imaging protocol in an animal model and investigate the feasibility of quantifying perfusion of lung parenchyma to perform functional analysis from 4D CT image data. A novel perfusion-CT protocol was designed with 25 scanning time points: the first at baseline and 24 scans after a bolus injection of contrast material. Post-contrast CT scanning images were acquired with a high sampling rate before the first blood recirculation and then a relatively low sampling rate until 10 minutes after administrating contrast agent. Lower radiation techniques were used to keep the radiation dose to an acceptable level. 2 Yorkshire swine with pulmonary emboli underwent this perfusion- CT protocol at suspended end inspiration. The software tools were designed to measure the quantitative perfusion parameters (perfusion, permeability, relative blood volume, blood flow, wash-in & wash-out enhancement) of voxel or interesting area of lung. The perfusion values were calculated for further lung functional analysis and presented visually as contrast enhancement maps for the volume being examined. The results show increased CT temporal sampling rate provides the feasibility of quantifying lung function and evaluating the pulmonary emboli. Differences between areas with known perfusion defects and those without perfusion defects were observed. In conclusion, the techniques to calculate the lung perfusion on animal model have potential application in human lung functional analysis such as evaluation of functional effects of pulmonary embolism. With further study, these techniques might be applicable in human lung parenchyma characterization and possibly for lung nodule characterization.

  20. 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.

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

    PubMed

    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.

  2. Rapid casting of patterned vascular networks for perfusable engineered 3D tissues

    PubMed Central

    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.

    2012-01-01

    In the absence of perfusable vascular networks, three-dimensional (3D) engineered tissues densely populated with cells quickly develop a necrotic core [1]. Yet the lack of a general approach to rapidly construct such networks remains a major challenge for 3D tissue culture [2–4]. Here, we 3D printed rigid filament networks of carbohydrate glass, and used them as a cytocompatible sacrificial template in engineered tissues containing living cells to generate cylindrical networks which 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 (ECMs), 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. PMID:22751181

  3. 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

  4. Brain/language relationships identified with diffusion and perfusion MRI: Clinical applications in neurology and neurosurgery.

    PubMed

    Hillis, Argye E

    2005-12-01

    Diffusion and perfusion MRI have contributed to stroke management by identifying patients with tissue "at risk" for further damage in acute stroke. However, the potential usefulness of these imaging modalities, along with diffusion tensor imaging, can be expanded by using these imaging techniques with concurrent assessment of language and other cognitive skills to identify the specific cognitive deficits that are associated with diffusion and perfusion abnormalities in particular brain regions. This paper illustrates how this combined behavioral and imaging methodology can yield information that is useful for predicting specific positive effects of intervention to restore blood flow in hypoperfused regions of brain identified with perfusion MRI, and for predicting negative effects of resection of particular brain regions or fiber bundles. Such data allow decisions about neurological and neurosurgical interventions to be based on specific risks and benefits in terms of functional consequences.

  5. Starter Feeding Supplementation Alters Colonic Mucosal Bacterial Communities and Modulates Mucosal Immune Homeostasis in Newborn Lambs

    PubMed Central

    Liu, Junhua; Bian, Gaorui; Sun, Daming; Zhu, Weiyun; Mao, Shengyong

    2017-01-01

    This study aims to investigate the effect of starter feeding supplementation on colonic mucosal bacterial communities and on mucosal immune homeostasis in pre-weaned lambs. We selected eight pairs of 10-day-old lamb twins. One twin was fed breast milk (M, n = 8), while the other was fed breast milk plus starter (M+S, n = 8). The lambs were sacrificed at 56 days age. Colonic content was collected to determine the pH and the concentrations of volatile fatty acids (VFA) and lactate. The colonic mucosa was harvested to characterize the bacterial communities using Illumina MiSeq sequencing and to determine mRNA expression levels of cytokines and toll-like receptors (TLR) using quantitative real-time PCR. The results show that starter feeding decreased luminal pH and increased the concentrations of acetate, propionate, butyrate, total VFA, and lactate in the colon. The principal coordinate analysis (PCA) and analysis of molecular variance show that starter feeding supplementation significantly affected the colonic mucosal bacterial communities with a higher relative abundance of the dominant taxa unclassified S24-7, Oscillibacter, Prevotella, Parabacteroides, Bifidobacterium, Ruminobacter, and Succinivibrio, and a lower proportion of unclassified Ruminococcaceae, RC9_gut_group, Blautia, Phocaeicola, Phascolarctobacterium, unclassified BS11_gut_group, unclassified family_XIII, and Campylobacter in lambs. Meanwhile, starter feeding decreased mRNA expression of TLR4 and cytokines TNF-α and IFN-γ in colonic tissue. Furthermore, the changes in the colonic mucosal mRNA expression of TLR and cytokines were associated with changes in mucosal bacterial composition. These findings may provide new insights into colonic mucosal bacteria and immune homeostasis in developing lambs. PMID:28382025

  6. 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.

  7. Clinical relevance of circulating mucosal-associated invariant T cell levels and their anti-cancer activity in patients with mucosal-associated cancer

    PubMed Central

    Jin, Hye-Mi; Park, Ki-Jeong; Kim, Tae-Jong; Kwon, Yong-Soo; Kee, Hae Jin; Kim, Jung-Chul; Kee, Seung-Jung; Park, Yong-Wook

    2016-01-01

    Mucosal-associated invariant T (MAIT) cells are an antimicrobial MR1-restricted T cell subset and play an important role in immune defense response to bacteria. However, little is known about the role of MAIT cells in cancer. The aims of this study were to examine the level and function of MAIT cells in cancer patients and to evaluate the clinical relevance of MAIT cell levels. Ninety-nine patients with cancer and 20 healthy controls were included in this study. Circulating MAIT cell levels were significantly reduced in patients with mucosal-associated cancers (MACs), such as gastric, colon and lung cancers, but their capacities for IFN-γ, IL-17, or TNF-α production were preserved. This MAIT cell deficiency was significantly correlated with N staging and carcinoembryonic antigen level. Percentages of MAIT cells were significantly higher in cancer tissue than in peripheral blood and immunofluorescent labeling showed MAIT cell infiltration into colon cancer tissues. Circulating MAIT cells exhibited high levels of CCR6 and CXCR6, and their corresponding chemokines, such as CCL20 and CXCL16, were strongly expressed in colon cancer tissues. Activated MAIT cells not only had lymphokine-activated killer activity, but they also had direct cytotoxicity on K562 cells via degranulation of granzyme B and perforin. This study primarily demonstrates that circulating MAIT cells are reduced in MAC patients due to migration to mucosal cancer tissues and they have the potential to kill cancer cells. In addition, this circulating MAIT cell deficiency is related to the degree of cancer progression in mucosal tissues. PMID:27517754

  8. 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

  9. 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.

  10. 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.

  11. 320-row CT renal perfusion imaging in patients with aortic dissection: A preliminary study

    PubMed Central

    Liu, Dongting; Liu, Jiayi; Wen, Zhaoying; Li, Yu; Sun, Zhonghua; Xu, Qin; Fan, Zhanming

    2017-01-01

    Objective To investigate the clinical value of renal perfusion imaging in patients with aortic dissection (AD) using 320-row computed tomography (CT), and to determine the relationship between renal CT perfusion imaging and various factors of aortic dissection. Methods Forty-three patients with AD who underwent 320-row CT renal perfusion before operation were prospectively enrolled in this study. Diagnosis of AD was confirmed by transthoracic echocardiography. Blood flow (BF) of bilateral renal perfusion was measured and analyzed. CT perfusion imaging signs of AD in relation to the type of AD, number of entry tears and the false lumen thrombus were observed and compared. Results The BF values of patients with type A AD were significantly lower than those of patients with type B AD (P = 0.004). No significant difference was found in the BF between different numbers of intimal tears (P = 0.288), but BF values were significantly higher in cases with a false lumen without thrombus and renal arteries arising from the true lumen than in those with thrombus (P = 0.036). The BF values measured between the true lumen, false lumen and overriding groups were different (P = 0.02), with the true lumen group having the highest. Also, the difference in BF values between true lumen and false lumen groups was statistically significant (P = 0.016), while no statistical significance was found in the other two groups (P > 0.05). The larger the size of intimal entry tears, the greater the BF values (P = 0.044). Conclusions This study shows a direct correlation between renal CT perfusion changes and AD, with the size, number of intimal tears, different types of AD, different renal artery origins and false lumen thrombosis, significantly affecting the perfusion values. PMID:28182709

  12. Evolution of pulmonary perfusion defects demonstrated with contrast-enhanced dynamic MR perfusion imaging.

    PubMed

    Howarth, N R; Beziat, C; Berthezène, Y

    1999-01-01

    Pulmonary perfusion defects can be demonstrated with contrast-enhanced dynamic MR perfusion imaging. We present the case of a patient with a pulmonary artery sarcoma who presented with a post-operative pulmonary embolus and was followed in the post-operative period with dynamic contrast-enhanced MR perfusion imaging. This technique allows rapid imaging of the first passage of contrast material through the lung after bolus injection in a peripheral vein. To our knowledge, this case report is the first to describe the use of this MR technique in showing the evolution of peripheral pulmonary perfusion defects associated with pulmonary emboli.

  13. Buccal mucosal graft in reconstructive urology: uses beyond urethral stricture.

    PubMed

    Pandey, Abhishek; Dican, Razvan; Beier, Jörn; Keller, Hansjörg

    2014-07-01

    The use of buccal mucosal grafts for the reconstruction of urethral strictures is an established procedure. Because of its robustness, the buccal mucosal graft could also potentially provide an alternative for other indications in reconstructive urology. We report here six consecutive patients who received a buccal mucosal graft for ureteral strictures, glans reconstruction and stoma stenosis. The follow up for all patients ranged from 26 to 50 months. The buccal mucosal graft showed excellent functional results for the ureteral strictures and stenosis from ureterocutaneostomy. For glans reconstructions, the buccal mucosal grafts delivered excellent cosmetic and functional results without causing meatal stenosis. We conclude the buccal mucosal graft can be used in reconstructive surgery beyond the reconstruction of urethral strictures.

  14. Reproducibility and variability of very low dose hepatic perfusion CT in metastatic liver disease

    PubMed Central

    Topcuoğlu, Osman Melih; Karçaaltıncaba, Muşturay; Akata, Deniz; Özmen, Mustafa Nasuh

    2016-01-01

    PURPOSE We aimed to determine the intra- and interobserver agreement on the software analysis of very low dose hepatic perfusion CT (pCT). METHODS A total of 53 pCT examinations were obtained from 21 patients (16 men, 5 women; mean age, 60.4 years) with proven liver metastasis from various primary cancers. The pCT examinations were analyzed by two readers independently and perfusion parameters were noted for whole liver, whole metastasis, metastasis wall, and normal-looking liver (liver tissue without metastasis) in regions of interest (ROIs). Readers repeated the analysis after an interval of one month. Intra- and interobserver agreements were assessed with intraclass correlation coefficients (ICC) and Bland-Altman statistics. RESULTS The mean ICCs of all ROIs between readers were 0.91, 0.93, 0.86, 0.45, 0.53, and 0.66 for blood flow (BF), blood volume (BV), permeability, arterial liver perfusion (ALP), portal venous perfusion (PVP) and hepatic perfusion index (HPI), respectively. The mean ICCs of all ROIs between readings were 0.86, 0.91, 0.81, 0.53, 0.56, and 0.71 for BF, BV, permeability, ALP, PVP, and HPI, respectively. There was greater agreement on the parameters measured for the whole metastasis than on the parameters measured for the metastasis wall. The effective dose of all perfusion CT studies was 2.9 mSv. CONCLUSION There is greater intra- and interobserver agreement for BF and BV than for permeability, ALP, PVP, and HPI at very low dose hepatic pCT. Permeability, ALP, PVP, and HPI parameters cannot be used in clinical practice for hepatic pCT with an effective dose of 2.9 mSv. PMID:27759566

  15. 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.

  16. 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.

  17. [99mTc-ECD dynamic SPECT in "luxury perfusion" of subacute stroke].

    PubMed

    Ogasawara, K; Fujiwara, S; Yoshimoto, T

    1995-11-01

    To evaluate the cerebral pharmacokinetics of 99mTc-ethyl cysteinate dimer (99mTc-ECD) at blood flow levels beyond the normal range, we investigated "luxury perfusion" in subacute stroke, ictal hyperperfusion in epilepsy and post-decompressive hyperemia in head trauma. All 7 patients showed a hyperactive area on SPECT studies using 99mTc-HM-PAO. 99mTc-ECD static image demonstrated a hyperactive area in both epilepsy and head trauma, and a hypoactive area in "luxury perfusion." On the dynamic SPECT of 99mTc-ECD in both epilepsy and head trauma, brain distribution of the tracer was determined within 2 min. postinjection and remained stable for up to 1 hour; however, "luxury perfusion" area showed a change from initial hyperactivity to late hypoactivity with the passage of time. The time activity curve in "luxury perfusion" area demonstrated a steep decrease of counts/pixel for up to 4-5 minutes postinjection, and a moderate decrease in the following phase. The early wash-out mechanism of 99mTc-ECD from "luxury perfusion" area can be described by a biexponential function including an initial steep decrease representing the rapid loss of the lipophilic complexes which were not metabolized in injured brain tissue.

  18. Characterization of renal parenchymal perfusion during experimental infrarenal aortic clamping and declamping with enhanced thermodiffusion electrodes.

    PubMed

    Kraus, T; Mehrabi, A; Angelescu, M; Golling, M; Allenberg, J R; Klar, E

    2001-07-01

    Despite multiple previous experimental and clinical investigations, it has not been fully clarified until now whether infrarenal aortic cross-clamping (IRAC) induces a significant disturbance of renal parenchymal perfusion. Most renal cortical flow data collected thus far have been heterogenous because of inherent limitations of available measurement technology. The enhanced thermal diffusion (TD) electrode is a newly developed and previously validated prototype device that allows continuous quantification of parenchymal kidney perfusion after local probe implantation. We monitored renal perfusion during experimental IRAC with TD for the first time, thereby also evaluating the potential applicability of the method in clinical aortic surgery. IRAC (20 min) followed by sudden declamping was performed in pigs under general anesthesia (n = 14). Renal cortical blood flow (RCBF) was continuously quantified by TD, total aortic flow (TABF) and renal artery flow (RABF) were measured by ultrasonic flow probes, and parameters of systemic circulation were determined by Swan-Ganz catheter. Our results showed that kidney perfusion can be continuously quantified using TD electrodes during experimental aortic surgery in a porcine model. IRAC does not lead to a significant impairment of RCBF in young pigs as measured by TD. Renal perfusion appears to be predominantly pressure driven. Consequently, abrubt aortic declamping can bring about prolonged renal ischemia. Transfer of the TD method to RCBF monitoring during clinical aortic surgery appears to be feasible and should be investigated in selected cases.

  19. Evidence for a common mucosal immune system in the pig.

    PubMed

    Wilson, Heather L; Obradovic, Milan R

    2015-07-01

    The majority of lymphocytes activated at mucosal sites receive instructions to home back to the local mucosa, but a portion also seed distal mucosa sites. By seeding distal sites with antigen-specific effector or memory lymphocytes, the foundation is laid for the animal's mucosal immune system to respond with a secondary response should to this antigen be encountered at this site in the future. The common mucosal immune system has been studied quite extensively in rodent models but less so in large animal models such as the pig. Reasons for this paucity of reported induction of the common mucosal immune system in this species may be that distal mucosal sites were examined but no induction was observed and therefore it was not reported. However, we suspect that the majority of investigators simply did not sample distal mucosal sites and therefore there is little evidence of immune response induction in the literature. It is our hope that more pig immunologists and infectious disease experts who perform mucosal immunizations or inoculations on pigs will sample distal mucosal sites and report their findings, whether results are positive or negative. In this review, we highlight papers that show that immunization/inoculation using one route triggers mucosal immune system induction locally, systemically, and within at least one distal mucosal site. Only by understanding whether immunizations at one site triggers immunity throughout the common mucosal immune system can we rationally develop vaccines for the pig, and through these works we can gather evidence about the mucosal immune system that may be extrapolated to other livestock species or humans.

  20. 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

  1. 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.

  2. 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

  3. Blood sugar test - blood

    MedlinePlus

    ... sugar; Blood sugar level; Fasting blood sugar; Glucose test; Diabetic screening - blood sugar test; Diabetes - blood sugar test ... The test may be done in the following ways: After you have not eaten anything for at least 8 ...

  4. Gut mucosal immunostimulation by lactic acid bacteria.

    PubMed

    Vitiñi, E; Alvarez, S; Medina, M; Medici, M; de Budeguer, M V; Perdigón, G

    2000-12-01

    The beneficial properties of lactic acid bacteria (LAB) on human health have been frequently demonstrated. The interaction of LAB with the lymphoid cells associated to the gut to activate the mucosal immune system and the mechanisms by which they can exert an adjuvant effect is still unclear, as well as if this property is common for all the LAB. We studied the influence of the oral administration of different geneous of LAB such as Lactobacillus casei, L. acidophilus, L. rhamnosus, L. delbrueckii subsp. bulgaricus, L. plantarum, Lactococcus lactis and Streptococcus thermophilus. We determined if the LAB assayed were able to stimulate the specific, the non-specific immune response (inflammatory response), or both. We demonstrated that all the bacteria assayed were able to increase the number of IgA producing cells associated to the lamina propria of small intestine. This effect was dose dependent. The increase in IgA+ producing cells was not always correlated with an increase in the CD4+ T cell number, indicating that some LAB assayed only induced clonal expansion of B cells triggered to produce IgA. Most of them, induced an increase in the number of cells involved in the inflammatory immune response. CD8+ T cell were diminished or not affected, with exception of L. plantarum that induced an increase at low dose. This fact would mean that LAB are unable to induce cytotoxicity mechanisms. We demonstrated the importance in the selection of LAB to be used as gut mucosal adjuvant. The different behaviours observed among them on the gut mucosal immune response, specially those that induce inflammatory immune response, show that not all the LAB can be used as oral adjuvant and that the beneficial effect of them can not generalized to genous or specie. The immunoadjuvant capacity would be a property of the strain assayed.

  5. Glycerol monolaurate prevents mucosal SIV transmission

    PubMed Central

    Li, Qingsheng; Estes, Jacob D.; Schlievert, Patrick M.; Duan, Lijie; Brosnahan, Amanda J.; Southern, Peter J.; Reilly, Cavan S.; Peterson, Marnie L.; Schultz-Darken, Nancy; Brunner, Kevin G.; Nephew, Karla R.; Pambuccian, Stefan; Lifson, Jeffrey D.; Carlis, John V.; Haase, Ashley T.

    2009-01-01

    While there has been great progress in treating HIV-1 infection1, preventing transmission has thus far proven an elusive goal. Indeed, recent trials of a candidate vaccine and microbicide have been disappointing, both for want of efficacy and concerns about increased rates of transmission2–4. Nonetheless, studies of vaginal transmission in the SIV-rhesus macaque model point to opportunities in the earliest stages of infection where a vaccine or microbicide might be protective, by limiting the expansion of infected founder populations at the portal of entry5, 6. Here we show in this SIV-macaque model, that an outside-in endocervical mucosal signalling system, involving MIP-3α, plasmacytoid dendritic cells and CCR5+cell-attracting chemokines produced by these cells, in combination with the innate immune and inflammatory responses to infection in both cervix and vagina, recruit CD4+T cells to fuel this obligate expansion. We then show that glycerol monolaurate, a widely used antimicrobial compound 7 with inhibitory activity against production of MIP-3α and other proinflammatory cytokines8, can inhibit mucosal signalling and the innate and inflammatory response to HIV-1 and SIV in vitro, and in vivo can protect rhesus macaques from acute infection despite repeated intra-vaginal exposure to high doses of SIV. This novel approach, plausibly linked to interfering with innate host responses that recruit the target cells necessary to establish systemic infection, opens a promising new avenue for development of effective interventions to block HIV-1 mucosal transmission. PMID:19262509

  6. 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

  7. Glycerol monolaurate prevents mucosal SIV transmission.

    PubMed

    Li, Qingsheng; Estes, Jacob D; Schlievert, Patrick M; Duan, Lijie; Brosnahan, Amanda J; Southern, Peter J; Reilly, Cavan S; Peterson, Marnie L; Schultz-Darken, Nancy; Brunner, Kevin G; Nephew, Karla R; Pambuccian, Stefan; Lifson, Jeffrey D; Carlis, John V; Haase, Ashley T

    2009-04-23

    Although there has been great progress in treating human immunodeficiency virus 1 (HIV-1) infection, preventing transmission has thus far proven an elusive goal. Indeed, recent trials of a candidate vaccine and microbicide have been disappointing, both for want of efficacy and concerns about increased rates of transmission. Nonetheless, studies of vaginal transmission in the simian immunodeficiency virus (SIV)-rhesus macaque (Macacca mulatta) model point to opportunities at the earliest stages of infection in which a vaccine or microbicide might be protective, by limiting the expansion of infected founder populations at the portal of entry. Here we show in this SIV-macaque model, that an outside-in endocervical mucosal signalling system, involving MIP-3alpha (also known as CCL20), plasmacytoid dendritic cells and CCR5(+ )cell-attracting chemokines produced by these cells, in combination with the innate immune and inflammatory responses to infection in both cervix and vagina, recruits CD4(+) T cells to fuel this obligate expansion. We then show that glycerol monolaurate-a widely used antimicrobial compound with inhibitory activity against the production of MIP-3alpha and other proinflammatory cytokines-can inhibit mucosal signalling and the innate and inflammatory response to HIV-1 and SIV in vitro, and in vivo it can protect rhesus macaques from acute infection despite repeated intra-vaginal exposure to high doses of SIV. This new approach, plausibly linked to interfering with innate host responses that recruit the target cells necessary to establish systemic infection, opens a promising new avenue for the development of effective interventions to block HIV-1 mucosal transmission.

  8. 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

  9. Oral lichen planus and lichenoid mucositis.

    PubMed

    De Rossi, Scott S; Ciarrocca, Katharine

    2014-04-01

    Oral lichen planus (OLP) is commonly found in middle-aged women. Although the cause is unknown, research points to several complex immunologic events and cells that are responsible for the inflammatory destruction and chronicity of these lesions. Biopsy for histologic diagnosis is recommended. The mainstay of treatment remains topical corticosteroids; however, newer therapies such as immunomodulating agents are available for recalcitrant lesions. In cases of lichenoid mucositis or reactions, treatment should be directed at identifying and removing the presumed cause. Given the apparent risk of squamous cell carcinoma in these patients, frequent follow-up and repeat biopsy are vital.

  10. 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

  11. The efficiency of granulocyte colony-stimulating factor in hemorrhagic mucositis and febrile neutropenia resulted from methotrexate toxicity.

    PubMed

    Ozkol, Hatice Uce; Toptas, Tayfur; Calka, Omer; Akdeniz, Necmettin

    2015-01-01

    Methotrexate (MTX) remains one of the most frequently used anti-metabolite agents in dermatology. MTX is an analog of folate that competitively and irreversibly inhibits dihydrofolate reductase. Oral mucositis is a common side effect of chemotherapy drugs and is characterized by erythema, pain, poor oral intake, pseudomembranous destruction, open ulceration and hemorrhage of the oral mucosa. In this paper, we report a 32-year-old female with a case of mucositis due to MTX intoxication that resulted from an overdose for rheumatoid arthritis. The patient had abdominal pain, vomiting, and nausea. During follow-up, the patient's white blood cell count was found to be 0.9 × 10(9)/L (4-10 × 10(9)/L). The patient developed fever exceeding 40 °C. The patient was consulted to the hematology service. They suggested using granulocyte colony-stimulating factor for febrile neutropenia. On the fifth day of treatment, the white blood cell count reached 5.3 × 10(9)/L and the patient's fever and mucositis started to resolve. Here, we presented a case of hemorrhagic mucositis and febrile neutropenia resulted from high-dose MTX that responded very well to granulocyte colony-stimulating factor treatment and we reviewed the literature.

  12. Rhubarb extract partially improves mucosal integrity in chemotherapy-induced intestinal mucositis

    PubMed Central

    Bajic, Juliana E; Eden, Georgina L; Lampton, Lorrinne S; Cheah, Ker Y; Lymn, Kerry A; Pei, Jinxin V; Yool, Andrea J; Howarth, Gordon S

    2016-01-01

    AIM To investigate the effects of orally gavaged aqueous rhubarb extract (RE) on 5-fluorouracil (5-FU)-induced intestinal mucositis in rats. METHODS Female Dark Agouti rats (n = 8/group) were gavaged daily (1 mL) with water, high-dose RE (HDR; 200 mg/kg) or low-dose RE (LDR; 20mg/kg) for eight days. Intestinal mucositis was induced (day 5) with 5-FU (150 mg/kg) via intraperitoneal injection. Intestinal tissue samples were collected for myeloperoxidase (MPO) activity and histological examination. Xenopus oocytes expressing aquaporin 4 water channels were prepared to examine the effect of aqueous RE on cell volume, indicating a potential mechanism responsible for modulating net fluid absorption and secretion in the gastrointestinal tract. Statistical significance was assumed at P < 0.05 by one-way ANOVA. RESULTS Bodyweight was significantly reduced in rats administered 5-FU compared to healthy controls (P < 0.01). Rats administered 5-FU significantly increased intestinal MPO levels (≥ 307%; P < 0.001), compared to healthy controls. However, LDR attenuated this effect in 5-FU treated rats, significantly decreasing ileal MPO activity (by 45%; P < 0.05), as compared to 5-FU controls. 5-FU significantly reduced intestinal mucosal thickness (by ≥ 29% P < 0.001) as compared to healthy controls. LDR significantly increased ileal mucosal thickness in 5-FU treated rats (19%; P < 0.05) relative to 5-FU controls. In xenopus oocytes expressing AQP4 water channels, RE selectively blocked water influx into the cell, induced by a decrease in external osmotic pressure. As water efflux was unaltered by the presence of extracellular RE, the directional flow of water across the epithelial barrier, in the presence of extracellular RE, indicated that RE may alleviate water loss across the epithelial barrier and promote intestinal health in chemotherapy-induced intestinal mucositis. CONCLUSION In summary, low dose RE improves selected parameters of mucosal integrity and reduces ileal

  13. The development of mucosal vaccines for both mucosal and systemic immune induction and the roles played by adjuvants

    PubMed Central

    2017-01-01

    Vaccination is the most successful immunological practice that improves the quality of human life and health. Vaccine materials include antigens of pathogens and adjuvants potentiating the effectiveness of vaccination. Vaccines are categorized using various criteria, including the vaccination material used and the method of administration. Traditionally, vaccines have been injected via needles. However, given that most pathogens first infect mucosal surfaces, there is increasing interest in the establishment of protective mucosal immunity, achieved by vaccination via mucosal routes. This review summarizes recent developments in mucosal vaccines and their associated adjuvants. PMID:28168169

  14. Perfusion deconvolution in DSC-MRI with dispersion-compliant bases.

    PubMed

    Pizzolato, Marco; Boutelier, Timothé; Deriche, Rachid

    2017-02-01

    Perfusion imaging of the brain via Dynamic Susceptibility Contrast MRI (DSC-MRI) allows tissue perfusion characterization by recovering the tissue impulse response function and scalar parameters such as the cerebral blood flow (CBF), blood volume (CBV), and mean transit time (MTT). However, the presence of bolus dispersion causes the data to reflect macrovascular properties, in addition to tissue perfusion. In this case, when performing deconvolution of the measured arterial and tissue concentration time-curves it is only possible to recover the effective, i.e. dispersed, response function and parameters. We introduce Dispersion-Compliant Bases (DCB) to represent the response function in the presence and absence of dispersion. We perform in silico and in vivo experiments, and show that DCB deconvolution outperforms oSVD and the state-of-the-art CPI+VTF techniques in the estimation of effective perfusion parameters, regardless of the presence and amount of dispersion. We also show that DCB deconvolution can be used as a pre-processing step to improve the estimation of dispersion-free parameters computed with CPI+VTF, which employs a model of the vascular transport function to characterize dispersion. Indeed, in silico results show a reduction of relative errors up to 50% for dispersion-free CBF and MTT. Moreover, the DCB method recovers effective response functions that comply with healthy and pathological scenarios, and offers the advantage of making no assumptions about the presence, amount, and nature of dispersion.

  15. The relationship between local scalp skin temperature and cutaneous perfusion during scalp cooling.

    PubMed

    Janssen, Francis-Paul E M; Rajan, Vinayakrishnan; Steenbergen, Wiendelt; van Leeuwen, Gerard M J; van Steenhoven, Anton A

    2007-08-01

    Cooling the scalp during administration of chemotherapy can prevent hair loss. It reduces both skin blood flow and hair follicle temperature, thus affecting drug supply and drug effect in the hair follicle. The extent to which these mechanisms contribute to the hair preservative effect of scalp cooling remains unknown. The purpose of this study was to establish a relationship between local scalp skin temperature and cutaneous blood flow during scalp cooling. We measured skin temperature and cutaneous perfusion during a cooling and re-warming experiment. Experiments on a single subject showed that the measurements were reproducible and that the response was identical for the two positions that were measured. Inter-subject variability was investigated on nine subjects. We found that for the first 10 degrees C of cooling, perfusion of the scalp skin decreases to below 40%. Perfusion can be further reduced to below 30% by a few degrees more cooling, but a plateau is reached after that. We found that a generally accepted relation in thermal physiology between temperature and perfusion (i.e. Q(10) relation) does not describe the data well, but we found an alternative relation that describes the average behavior significantly better.

  16. 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.

  17. 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

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  19. Effect of carotid occlusion and of perfusion pressure on renal function in conscious dogs.

    PubMed

    Gross, R; Kirchheim, H; Ruffmann, K

    1981-06-01

    We studied the effect of bilateral common carotid occlusion (implanted pneumatic cuffs) on renal blood flow (electromagnetic flowmeter) and renal function (implanted ureteral catheter) in nine chronically instrumented, conscious dogs on a high sodium diet (14 mmol/kg body weight per day). By means of suprarenal aortic constriction (pneumatic cuff) the influence of renal perfusion pressure was investigated. There was no change in renal blood flow or glomerular filtration rate (inulin clearance) with either reflexly increasing (+49.6%) or constant renal perfusion pressure. Carotid occlusion caused an increase of urine output by 80.5% and of sodium excretion by 85.3% due to a fall in fractional sodium reabsorption (-0.9%) when renal perfusion pressure was allowed to rise. Neither an increase of diuresis or sodium excretion nor an antinatriuresis was observed when renal perfusion pressure was kept constant during carotid occlusion. We conclude that, in conscious dogs at rest, the moderate sympathetic activation associated with carotid occlusion is too small to induce renal sympathetic vasoconstriction or antinatriuresis. The "carotid sinus polyuria" is a pressure-diuresis.

  20. Acute radiation effects on cutaneous microvasculature: evaluation with a laser Doppler perfusion monitor

    SciTech Connect

    Amols, H.I.; Goffman, T.E.; Komaki, R.; Cox, J.D.

    1988-11-01

    Laser Doppler perfusion monitoring is a noninvasive technique for measuring blood flow in epidermal microvasculature that makes use of the frequency shift of light reflected from red blood cells. Measurements in patients undergoing radiation therapy show increases in blood flow of ten to 25 times baseline at doses above 50 Gy, and increases are observed with doses as low as 2 Gy. Follow-up measurements show rapid decreases in flow levels after completion of therapy, but levels remain elevated even at 1 year.

  1. GPU-accelerated voxelwise hepatic perfusion quantification.

    PubMed

    Wang, H; Cao, Y

    2012-09-07

    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.

  2. 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.

  3. Effects of renal perfusion pressure on renal medullary hydrogen peroxide and nitric oxide production.

    PubMed

    Jin, Chunhua; Hu, Chunyan; Polichnowski, Aaron; Mori, Takefumi; Skelton, Meredith; Ito, Sadayoshi; Cowley, Allen W

    2009-06-01

    Studies were designed to determine the effects of increases of renal perfusion pressure on the production of hydrogen peroxide (H(2)O(2)) and NO(2)(-)+NO(3)(-) within the renal outer medulla. Sprague-Dawley rats were studied with either the renal capsule intact or removed to ascertain the contribution of changes of medullary blood flow and renal interstitial hydrostatic pressure on H(2)O(2) and NO(2)(-)+NO(3)(-) production. Responses to three 30-minute step changes of renal perfusion pressure (from approximately 85 to approximately 115 to approximately 145 mm Hg) were studied using adjustable aortic occluders proximal and distal to the left renal artery. Medullary interstitial H(2)O(2) determined by microdialysis increased at each level of renal perfusion pressure from 640 to 874 to 1593 nmol/L, as did H(2)O(2) urinary excretion rates, and these responses were significantly attenuated by decapsulation. Medullary interstitial NO(2)(-)+NO(3)(-) increased from 9.2 to 13.8 to 16.1 mumol/L, with parallel changes in urine NO(2)(-)+NO(3)(-), but decapsulation did not significantly blunt these responses. Over the range of renal perfusion pressure, medullary blood flow (laser-Doppler flowmetry) rose approximately 30% and renal interstitial hydrostatic pressure rose from 7.8 to 19.7 cm H(2)O. Renal interstitial hydrostatic pressure and the natriuretic and diuretic responses were significantly attenuated with decapsulation, but medullary blood flow was not affected. The data indicate that pressure-induced increases of H(2)O(2) emanated largely from increased tubular flow rates to the medullary thick-ascending limbs of Henle and NO largely from increased medullary blood flow to the vasa recta. The parallel pressure-induced increases of H(2)O(2) and NO indicate a participation in shaping the "normal" pressure-natriuresis relationship and explain why an imbalance in either would affect the blood pressure salt sensitivity.

  4. Regulation of Coronary Blood Flow.

    PubMed

    Goodwill, Adam G; Dick, Gregory M; Kiel, Alexander M; Tune, Johnathan D

    2017-03-16

    The heart is uniquely responsible for providing its own blood supply through the coronary circulation. Regulation of coronary blood flow is quite complex and, after over 100 years of dedicated research, is understood to be dictated through multiple mechanisms that include extravascular compressive forces (tissue pressure), coronary perfusion pressure, myogenic, local metabolic, endothelial as well as neural and hormonal influences. While each of these determinants can have profound influence over myocardial perfusion, largely through effects on end-effector ion channels, these mechanisms collectively modulate coronary vascular resistance and act to ensure that the myocardial requirements for oxygen and substrates are adequately provided by the coronary circulation. The purpose of this series of Comprehensive Physiology is to highlight current knowledge regarding the physiologic regulation of coronary blood flow, with emphasis on functional anatomy and the interplay between the physical and biological determinants of myocardial oxygen delivery. © 2017 American Physiological Society. Compr Physiol 7:321-382, 2017.

  5. Iron medication-induced gastric mucosal injury.

    PubMed

    Zhang, Xuchen; Ouyang, Jie; Wieczorek, Rosemary; DeSoto, Fidelina

    2009-01-01

    Severe gastrointestinal erosion, ulcer, necrosis and strictures after an acute iron overdose are well described. However, gastric mucosal injury in patients receiving therapeutic iron has received only scant recognition despite its wide use. We report a case of iron medication-induced gastric mucosal injury in a 76-year-old male who presented with iron deficiency anemia and had been taking ferrous sulfate tablet for 4 years. Esophagogastroduodenoscopy (EGD) revealed a pale, villous appearing flat lesion along the lesser curvature of gastric body. Histopathologic examination of EGD biopsies of the flat lesion showed brown crystalline materials deposited in the lamina propria of gastric mucosa, which was accompanied with fibrosis, chronic inflammation, and foreign body reaction. The crystalline materials were covered and admixed with gastric epithelium. Prussian blue iron stain confirmed that the brown crystalline materials were iron. The iron and hemosiderin accumulation was also seen in cytoplasm of epithelial cells and lumen of fundic gastric glands. The recognition and reporting by pathologists of iron-induced changes in EGD biopsies will alert clinicians to this underrecognized but easily correctable complication by alternative forms of iron therapy, such as liquid preparation.

  6. Th17 cells and Mucosal Host Defense

    PubMed Central

    Aujla, Shean J.; Dubin, Patricia J.; Kolls, Jay K.

    2008-01-01

    Th17 cells are a new lineage of T-cells that are controlled by the transcription factor RORγt and develop independent of GATA-3, T-bet, Stat 4 and Stat 6. Novel effector molecules produced by these cells include IL-17A, IL-17F, IL-22, and IL-26. IL-17RA binds IL-17A and IL-17F and is critical for host defense against extracellular planktonic bacteria by regulating chemokine gradients for neutrophil emigration into infected tissue sites as well as host granulopoiesis. Moreover IL-17 and IL-22 regulate the production of antimicrobial proteins in mucosal epithelium. Although TGF-β1 and IL-6 have been shown to be critical for development of Th17 cells from naïve precursors, IL-23 is also important in regulating IL-17 release in mucosal tissues in response to infectious stimuli. Compared to Th1 cells, IL-23 and IL-17 show limited roles in controlling host defense against primary infections with intracellular bacteria such as Mycobacterium tuberculosis suggesting a predominate role of the Th17 lineage in host defense against extracellular pathogens. However in the setting of chronic biofilm infections, as that occurs with Cystic Fibrosis or bronchetctasis, Th17 cells may be key contributors of tissue injury. PMID:18054248

  7. Validation of minimally invasive measurement of myocardial perfusion using electron beam computed tomography and application in human volunteers

    PubMed Central

    Bell, M; Lerman, L; Rumberger, J

    1999-01-01

    OBJECTIVES—To measure myocardial perfusion using an estimate of intramyocardial vascular volume obtained by electron beam computed tomography (EBCT) in an animal model; to assess the feasibility and validity of measuring regional myocardial perfusion in human volunteers using the techniques developed and validated in the animal studies.
METHODS—Measurements of myocardial perfusion with EBCT employing intravenous contrast injections were compared with radioactive microsphere measurements (flow 57 to 346 ml/100 g/min) in seven closed chest dogs. Fourteen human volunteers then underwent EBCT scans using intravenous contrast injections.
RESULTS—Mean (SEM) global intramyocardial vascular volume by EBCT was 7.6 (1.1)%. The correlation between global EBCT (y) and microsphere (x) perfusion was y = 0.59x + 15.56 (r = 0.86) before, and y = 0.72x + 6.06 (r = 0.88) after correcting for intramyocardial vascular volume. Regional perfusion correlation was y = 0.75x + 23.84 (r = 0.82). Corresponding improvements in agreement between the two techniques were also seen using Bland-Altman plots. In the human subjects, mean resting global myocardial flow was 98 (6) ml/100 g/min, with homogeneous flow across all regions. In 10 of these subjects, perfusion was studied during coronary vasodilatation using intravenous adenosine. Global flow increased from 93 (5) ml/100 g/min at rest to 250 (19) ml/100 g/min during adenosine (p < 0.001), with an average perfusion reserve ratio of 2.8 (0.2). Similar changes in regional perfusion were observed and were uniform throughout all regions, with a mean regional perfusion reserve ratio of 2.8 (0.3).
CONCLUSIONS—Accounting for intramyocardial vascular volume improves the accuracy of EBCT measurements of myocardial perfusion when using intravenous contrast injections. The feasibility of providing accurate measurements of global and regional myocardial perfusion and perfusion reserve in people using this

  8. Blood typing

    MedlinePlus

    ... ABO blood typing; Blood group; Anemia - immune hemolytic blood type; ABO blood type; A blood type; AB blood type; O blood type ... The 2 steps above can accurately determine your blood type. Rh typing uses a method similar to ABO ...

  9. 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.

  10. Thermal tests for laser Doppler perfusion measurements in Raynaud's syndrome

    NASA Astrophysics Data System (ADS)

    Kacprzak, Michal; Skora, A.; Obidzinska, J.; Zbiec, A.; Maniewski, Roman; Staszkiewicz, W.

    2004-07-01

    The laser Doppler method offers a non-invasive, real time technique for monitoring of blood perfusion in microcirculation. In practical measurements the perfusion index is given only in relative values. Thus, accurate and reproducible results can be only obtained when using a well controlled stimulation test. The aim of this study was evaluation of the thermal stimulation test, which is frequently used to investigate microcirculation in patients with Raynaud's syndrome. Three types of thermal tests, in which air or water with temperature in range 5°C - 40°C were used. Ten normal volunteers and fifteen patients with clinical symptoms of the primary Raynaud's syndrome were enrolled in this study. To estimate skin microcirculation changes during the thermal test, the multichannel laser Doppler system and laser Doppler scanner were used. The obtained results were analyzed from the point of view of the efficiency of these methods and the thermal provocative tests in differentiation of normal subjects and patient with Raynaud's syndrome.

  11. Minimally invasive treatment of oral ranula with a mucosal tunnel.

    PubMed

    Jia, T; Xing, L; Zhu, F; Jin, X; Liu, L; Tao, J; Chen, Y; Gao, Z; Zhang, H

    2015-02-01

    We have developed a new method for minimally-invasive treatment of uncomplicated oral ranulas using a mucosal tunnel, and we report the clinical outcome. We constructed a mucosal tunnel for each of 35 patients who presented with an oral ranula, by making 2 parallel incisions across the top of the protruding ranula 2-3mm apart, and dissected the soft tissue along the incisions to its wall. The fluid was removed and the cavity irrigated with normal saline. The wall of the ranula was not treated. The first mucosal tunnel was made by suturing the base of the mucosal strip to the deepest part of the wall of the ranula. The mucosal base of the tunnel and the deepest part of the base of the ranula were fixed with absorbable sutures. The two external edges of the incisions were sutured together to form the second mucosal tunnel, and apposing sutures were inserted between the two parallel incisions to form two natural mucosal tunnels. The duration of follow-up ranged from 1 to 5 years. One patient was lost to follow-up and 34 patients were cured. Outcomes were satisfactory without relapse during the follow-up period and the patients were satisfied with the outcome. The mucosal tunnel is a safe, effective, simple, and minimally-invasive treatment for oral ranula.

  12. Induction of mucosal immunity through systemic immunization: Phantom or reality?

    PubMed Central

    Su, Fei; Patel, Girishchandra B.; Hu, Songhua; Chen, Wangxue

    2016-01-01

    ABSTRACT 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

  13. 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.

  14. Quantitative evaluation of mucosal vascular contrast in narrow band imaging using Monte Carlo modeling

    NASA Astrophysics Data System (ADS)

    Le, Du; Wang, Quanzeng; Ramella-Roman, Jessica; Pfefer, Joshua

    2012-06-01

    Narrow-band imaging (NBI) is a spectrally-selective reflectance imaging technique for enhanced visualization of superficial vasculature. Prior clinical studies have indicated NBI's potential for detection of vasculature abnormalities associated with gastrointestinal mucosal neoplasia. While the basic mechanisms behind the increased vessel contrast - hemoglobin absorption and tissue scattering - are known, a quantitative understanding of the effect of tissue and device parameters has not been achieved. In this investigation, we developed and implemented a numerical model of light propagation that simulates NBI reflectance distributions. This was accomplished by incorporating mucosal tissue layers and vessel-like structures in a voxel-based Monte Carlo algorithm. Epithelial and mucosal layers as well as blood vessels were defined using wavelength-specific optical properties. The model was implemented to calculate reflectance distributions and vessel contrast values as a function of vessel depth (0.05 to 0.50 mm) and diameter (0.01 to 0.10 mm). These relationships were determined for NBI wavelengths of 410 nm and 540 nm, as well as broadband illumination common to standard endoscopic imaging. The effects of illumination bandwidth on vessel contrast were also simulated. Our results provide a quantitative analysis of the effect of absorption and scattering on vessel contrast. Additional insights and potential approaches for improving NBI system contrast are discussed.

  15. Mass Cytometry of the Human Mucosal Immune System Identifies Tissue- and Disease-Associated Immune Subsets.

    PubMed

    van Unen, Vincent; Li, Na; Molendijk, Ilse; Temurhan, Mine; Höllt, Thomas; van der Meulen-de Jong, Andrea E; Verspaget, Hein W; Mearin, M Luisa; Mulder, Chris J; van Bergen, Jeroen; Lelieveldt, Boudewijn P F; Koning, Frits

    2016-05-17

    Inflammatory intestinal diseases are characterized by abnormal immune responses and affect distinct locations of the gastrointestinal tract. Although the role of several immune subsets in driving intestinal pathology has been studied, a system-wide approach that simultaneously interrogates all major lineages on a single-cell basis is lacking. We used high-dimensional mass cytometry to generate a system-wide view of the human mucosal immune system in health and disease. We distinguished 142 immune subsets and through computational applications found distinct immune subsets in peripheral blood mononuclear cells and intestinal biopsies that distinguished patients from controls. In addition, mucosal lymphoid malignancies were readily detected as well as precursors from which these likely derived. These findings indicate that an integrated high-dimensional analysis of the entire immune system can identify immune subsets associated with the pathogenesis of complex intestinal disorders. This might have implications for diagnostic procedures, immune-monitoring, and treatment of intestinal diseases and mucosal malignancies.

  16. Recent progress in HIV vaccines inducing mucosal immune responses.

    PubMed

    Pavot, Vincent; Rochereau, Nicolas; Lawrence, Philip; Girard, Marc P; Genin, Christian; Verrier, Bernard; Paul, Stéphane

    2014-07-31

    In spite of several attempts over many years at developing a HIV vaccine based on classical strategies, none has convincingly succeeded to date. As HIV is transmitted primarily by the mucosal route, particularly through sexual intercourse, understanding antiviral immunity at mucosal sites is of major importance. An ideal vaccine should elicit HIV-specific antibodies and mucosal CD8⁺ cytotoxic T-lymphocyte (CTL) as a first line of defense at a very early stage of HIV infection, before the virus can disseminate into the secondary lymphoid organs in mucosal and systemic tissues. A primary focus of HIV preventive vaccine research is therefore the induction of protective immune responses in these crucial early stages of HIV infection. Numerous approaches are being studied in the field, including building upon the recent RV144 clinical trial. In this article, we will review current strategies and briefly discuss the use of adjuvants in designing HIV vaccines that induce mucosal immune responses.

  17. HIV and mucosal barrier interactions: consequences for transmission and pathogenesis.

    PubMed

    Burgener, Adam; McGowan, Ian; Klatt, Nichole R

    2015-10-01

    The mucosal barrier plays an integral function in human health as it is the primary defense against pathogens, and provides a critical transition between the external environment and the human internal body. In the context of HIV infection, the most relevant mucosal surfaces include those of the gastrointestinal (GI) and genital tract compartments. Several components help maintain the effectiveness of this mucosal surface, including the physical anatomy of the barrier, cellular immunity, soluble factors, and interactions between the epithelial barrier and the local microenvironment, including mucus and host microbiota. Any defects in barrier integrity or function can rapidly lead to an increase in acquisition risk, or with established infection may result in increased pathogenesis, morbidities, or mortality. Indeed, a key feature to all aspects of HIV infection from transmission to pathogenesis is disruption and/or dysfunction of mucosal barriers. Herein, we will detail the host-pathogen relationship of HIV and mucosal barriers in both of these scenarios.

  18. Brain perfusion and markers of neurodegeneration in rapid eye movement sleep behavior disorder.

    PubMed

    Vendette, Mélanie; Gagnon, Jean-François; Soucy, Jean-Paul; Gosselin, Nadia; Postuma, Ronald B; Tuineag, Maria; Godin, Isabelle; Montplaisir, Jacques

    2011-08-01

    Potential early markers of neurodegeneration such as subtle motor signs, reduced color discrimination, olfactory impairment, and brain perfusion abnormalities have been reported in idiopathic rapid eye movement sleep behavior disorder, a risk factor for Parkinson's disease and Lewy body dementia. The aim of this study was to reproduce observations of regional cerebral blood flow abnormalities in a larger independent sample of patients and to explore correlations between regional cerebral blood flow and markers of neurodegeneration. Twenty patients with idiopathic rapid eye movement sleep behavior disorder and 20 healthy controls were studied by single-photon emission computerized tomography. Motor examination, color discrimination, and olfactory identification were examined. Patients with rapid eye movement sleep behavior disorder showed decreased regional cerebral blood flow in the frontal cortex and in medial parietal areas and increased regional cerebral blood flow in subcortical regions including the bilateral pons, putamen, and hippocampus. In rapid eye movement sleep behavior disorder, brain perfusion in the frontal cortex and occipital areas was associated with poorer performance in the color discrimination test. Moreover, a relationship between loss of olfactory discrimination and regional cerebral blood flow reduction in the bilateral anterior parahippocampal gyrus, a region known to be involved in olfactory functions, was found. This study provides further evidence of regional cerebral blood flow abnormalities in rapid eye movement sleep behavior disorder that are similar to those seen in Parkinson's disease and Lewy body dementia. Moreover, regional cerebral blood flow anomalies were associated with markers of neurodegeneration.

  19. 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.

  20. 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.

  1. Systemic uptake of buprenorphine by cats after oral mucosal administration.

    PubMed

    Robertson, S A; Taylor, P M; Sear, J W

    2003-05-31

    The plasma concentration of buprenorphine was measured by radioimmunoassay in six female cats after the administration of 0.01 mg/kg (0.033 ml/kg) buprenorphine hydrochloride solution into the side of the cat's mouth. Blood samples were taken through a preplaced jugular catheter before and one, two, four, six, 10, 15, 30, 45 and 60 minutes, and two, four, six, 12 and 24 hours after the dose was administered. The buprenorphine was accepted well by all the cats and did not cause salivation or vomiting. Its median peak plasma concentration was 7.5 ng/ml and was reached after 15 minutes. The pharmacokinetic data were similar to the pharmacokinetic data obtained after the intramuscular and intravenous administration of buprenorphine to cats from the same colony, suggesting that the mucosal route of administration should be as effective as intravenous and intramuscular injections. In addition, the pH of the oral cavity of 26 cats was measured with pH paper, and 100 cat owners were asked their preferred method of administering drugs to cats. The pH of the cats' mouths was between 8 and 9, and the technique preferred by the cat owners was the use of drops placed in the mouth.

  2. Endoscopic mucosal resection of early stage colon neuroendocrine carcinoma

    PubMed Central

    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

  3. 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

  4. 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

  5. Verapamil prevents silent myocardial perfusion abnormalities during exercise in asymptomatic patients with hypertrophic cardiomyopathy

    SciTech Connect

    Udelson, J.E.; Bonow, R.O.; O'Gara, P.T.; Maron, B.J.; Van Lingen, A.; Bacharach, S.L.; Epstein, S.E.

    1989-05-01

    Recent studies indicate that reversible 201Tl perfusion defects, compatible with silent myocardial ischemia, commonly develop during exercise in asymptomatic or mildly symptomatic patients with hypertrophic cardiomyopathy (HCM). To determine whether this represents a dynamic process that may be modified favorably by medical therapy, we studied 29 asymptomatic or minimally symptomatic patients with HCM, aged 12-55 years (mean, 28), with exercise 201Tl emission computed tomography under control conditions and again after 1 week of oral verapamil (mean dosage, 453 mg/day). Treadmill time increased slightly during verapamil (21.0 +/- 3.6 to 21.9 +/- 2.7 minutes, p less than 0.005), but peak heart rate-blood pressure product was unchanged (26.3 +/- 6.0 X 10(3)) compared with 25.0 +/- 6.4 X 10(3). Two midventricular short-axis images per study were divided into five regions each, and each of these 10 regions was then analyzed on a 0-2 scale by three observers blinded with regard to the patients' therapy. Average regional scores of 1.5 or less were considered to represent perfusion defects, and a change in regional score of 0.5 or more was considered to constitute a significant change. During control studies, 15 patients (52%) developed perfusion defects with exercise (average, 3.7 regions per patient). In 14 of these patients, all perfusion defects completely reversed after 3 hours of rest; one patient had fixed defects. After administration of verapamil, exercise perfusion scores improved in 10 of the 14 patients (71%) with reversible defects; there was overall improvement in 34 of 50 (68%) regions with initially reversible perfusion defects.

  6. The effect of perfusion flow on oxidative metabolism during cardiopulmonary bypass.

    PubMed

    Baraka, A

    1993-06-01

    The influence of perfusion flow rate on whole-body oxygen consumption (VO2), central venous hemoglobin oxygen saturation (SVO2), and central venous arterial oxygen tension (PVO2) during hypothermic hemodilutional nonpulsatile cardiopulmonary bypass was investigated in 20 patients undergoing coronary artery bypass grafting. In 10 patients, the perfusion flow was 2.4 L.min-1 x m-2 (Group I), whereas a flow of 1.2 L.min-1 x m-2 was used in the other 10 patients (Group II). When the body temperature was 29.7 +/- 1.2 degrees C (Group I) and 29.6 +/- 0.8 degrees C (Group II), mixed venous and arterial blood were sampled simultaneously, and whole-body oxygen consumption was calculated. Data collected during hypothermia were compared with the corresponding values achieved after rewarming to 37 degrees C. In both groups, the whole-body oxygen consumption during hypothermia was lower by about 45% than the VO2 after rewarming. However, SVO2 during the low perfusion flow was not significantly different from SVO2 after rewarming, whereas the temperature-corrected PVO2 was significantly lower. In contrast, the high-perfusion flow provided luxury perfusion as evident by the high SVO2, and maintained the temperature-corrected PVO2 within the normothermic range. Thus, maintenance of the normothermic perfusion flow rate during moderate hypothermic hemodilutional cardiopulmonary bypass may provide a safety margin that may compensate for unexpected increase of oxygen consumption or decrease of oxygen delivery.

  7. The mesenterially perfused rat small intestine: A versatile approach for pharmacological testings.

    PubMed

    Schreiber, Dominik; Klotz, Markus; Laures, Kerstin; Clasohm, Jasmin; Bischof, Michael; Schäfer, Karl-Herbert

    2014-05-01

    Pharmaceutical compounds enter the body via several major natural gateways; i.e. the lung, the skin and the gastrointestinal tract. Drug application during surgical operations can lead to severe impairment of gastrointestinal motility, which can contribute to a paralytic ileus. Here we investigated an ex vivo perfused small intestine model that allows us to ascertain the influence of pharmaceuticals upon the gut. Corresponding segments from the proximal jejunum of adult rats were used. Their mesenteric arteries and veins were cannulated and the jejunal segment excised. The individual segments were placed in a custom designed perfusion chamber and perfusion performed through the intestinal lumen as well as the mesenteric superior artery. Three test drugs, which are commonly used in anesthesiology; i.e. pentobarbital, propofol and ketamine were administered via the blood vessels. Their effects upon gastrointestinal motility patterns were evaluated by optical measurements. Longitudinal and pendular movements were distinguishable and separately analyzed. Pharmacological effects of the individual substances could be investigated. Propofol (50-200 μg/ml) was found to decrease intestinal motility, especially longitudinal movements in a dose dependent manner. Pentobarbital decreased intestinal motility only at high concentrations, above 2.5 mg/ml. A dose of 2.5 mg/ml lead to an increase in longitudinal- and pendular movements in comparison to control, while ketamine (2.5-10 mg/ml) did not alter intestinal motility at all. Histological examination of the perfused segments revealed only minor changes in tissue morphology after perfusion. The perfusion approach shown here allows for the identification of compounds which interfere with gut motility in a highly sophisticated way. It is suitable for characterization of drug and dose specific changes in motility patterns and can be used in drug development and preclinical studies.

  8. Differential Activation of Pontomedullary Nuclei by Acid Perfusion of Different Regions of the Esophagus

    PubMed Central

    Lang, Ivan M.; Medda, Bidyut K.; Shaker, Reza

    2010-01-01

    The objective of this study was to determine the brain stem nuclei and physiological responses activated by esophageal acidification. The effects of perfusion of the cervical (ESOc), or thoracic (ESOt) esophagus with PBS or HCl on c-fos immunoreactivity of the brain stem or on physiological variables, and the effects of vagotomy were examined in anesthetized cats. We found that acidification of the ESOc increased the number of c-fos positive neurons in the area postrema (AP), vestibular nucleus (VN), parabrachial nucleus (PBN), nucleus ambiguus (NA), dorsal motor nucleus (DMN), and all subnuclei of the nucleus tractus solitarius (NTS), but one. Acidification of the ESOt activated neurons in the central (CE), caudal (CD), dorsomedial (DM), dorsolateral (DL), ventromedial (VM) subnuclei of NTS, and the DMN. Vagotomy blocked all c-fos responses to acid perfusion of the whole esophagus (ESOw). Perfusion of the ESOc or ESOt with PBS activated secondary peristalsis (2P), but had no effect on blood pressure, heart rate, or respiratory rate. Perfusion of the ESOc, but not ESOt, with HCL activated pharyngeal swallowing (PS), profuse salivation, or physiological correlates of emesis. Vagotomy blocked all physiological effects of ESOw perfusion. We conclude that acidification of the ESOc and ESOt activate different sets of pontomedullary nuclei and different physiological responses. The NTSce, NTScom, NTSdm, and DMN are associated with activation of 2P, the NTSim and NTSis, are associated with activation of PS, and the AP, VN, and PBN are associated with activation of emesis and perhaps nausea. All responses to esophageal fluid perfusion or acidification are mediated by the vagus nerves. PMID:20655885

  9. Myocardial perfusion scintigraphy: the evidence

    PubMed Central

    Anagnostopoulos, C.; Cerqueira, M.; Ell, P. J.; Flint, E. J.; Harbinson, M.; Kelion, A. D.; Al-Mohammad, A.; Prvulovich, E. M.; Shaw, L. J.; Tweddel, A. C.

    2003-01-01

    This review summarises the evidence for the role of myocardial perfusion scintigraphy (MPS) in patients with known or suspected coronary artery disease. It is the product of a consensus conference organised by the British Cardiac Society, the British Nuclear Cardiology Society and the British Nuclear Medicine Society and is endorsed by the Royal College of Physicians of London and the Royal College of Radiologists. It was used to inform the UK National Institute of Clinical Excellence in their appraisal of MPS in patients with chest pain and myocardial infarction. MPS is a well-established, non-invasive imaging technique with a large body of evidence to support its effectiveness in the diagnosis and management of angina and myocardial infarction. It is more accurate than the exercise ECG in detecting myocardial ischaemia and it is the single most powerful technique for predicting future coronary events. The high diagnostic accuracy of MPS allows reliable risk stratification and guides the selection of patients for further interventions, such as revascularisation. This in turn allows more appropriate utilisation of resources, with the potential for both improved clinical outcomes and greater cost-effectiveness. Evidence from modelling and observational studies supports the enhanced cost-effectiveness associated with MPS use. In patients presenting with stable or acute chest pain, strategies of investigation involving MPS are more cost-effective than those not using the technique. MPS also has particular advantages over alternative techniques in the management of a number of patient subgroups, including women, the elderly and those with diabetes, and its use will have a favourable impact on cost-effectiveness in these groups. MPS is already an integral part of many clinical guidelines for the investigation and management of angina and myocardial infarction. However, the technique is underutilised in the UK, as judged by the inappropriately long waiting times and by

  10. 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

  11. Cardiac tissue engineering using perfusion bioreactor systems

    PubMed Central

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

    2009-01-01

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

  12. Canine Autoanticoagulation during Extracorporeal Perfusion.

    DTIC Science & Technology

    1979-12-19

    eviscerated as .o’: atr midline laparatomy, the celiac , superior and inerior ee ..: re ligated and divided between ligatures and the following x-azr C...extreme care taken to prevent loss of blood. In half of the experiments, the hepatic artery was maintained. patent by sectioning the celiac artery distal...to the origin of the hepatic artery; in the other half, the celiac artery was divided near its origin at the aorta, thus preventing flow via the

  13. CT Perfusion with Acetazolamide Challenge in C6 Gliomas and Angiogenesis

    PubMed Central

    Feng, Xiao-Yuan; Qiang, Jin-Wei; Zhang, Jia-wen; Wang, Yong-gang; Liu, Ying

    2015-01-01

    Background This study was performed to investigate the correlation between CT perfusion with acetazolamide challenge and angiogenesis in C6 gliomas. Methods Thirty-two male Sprague-Dawley rats were evaluated. The rats were divided randomly to four groups: eight rats with orthotopically implanted C6 gliomas at 10-days old (Group A), eight rats with gliomas at 14-days old (Group B), eight rats with gliomas at 18-days old (Group C), eight rats with orthotopically injected normal saline served as controls. CT perfusion was performed before and after administration of acetazolamide. Changes in perfusion parameters due to acetazolamide administration were calculated and analyzed. Results Elevated carbon dioxide partial pressure and decreased pH were found in all 32 rats post acetazolamide challenge (P<0.01). Cerebral blood flowpre-challenge was increased in group C (95.0±2.5 ml/100g/min), as compared to group B (80.1±11.3 ml/100g/min) and group A (63.1±2.1 ml/100g/min). Cerebral blood flow percentage changes were detected with a reduction in group C (54.2±4.8%) as compared to controls (111.3±22.2%). Cerebral blood volume pre-challenge was increased in group C (50.8±1.7ml/100g), as compared to group B (45.7±1.9 ml/100g) and group A (38.2±0.8 ml/100g). Cerebral blood volume percentage changes were decreased in group C (23.5±4.6%) as compared to controls (113.5±30.4%). Angiogenesis ratio = [(CD105-MVD) / (FVIII-MVD)] ×100%. Positive correlations were observed between CD105-microvessel density, angiogenesis ratio, vascular endothelial growth factor, proliferation marker and cerebral blood flowpre-challenge, cerebral blood volume pre-challenge. Negative correlations were observed between CD105-microvessel density and cerebral blood flow percentage changes (P<0.01, correlation coefficient r=-0.788), cerebral blood volume percentage changes (P<0.01, r=-0.703). Negative correlations were observed between angiogenesis ratio, vascular endothelial growth factor

  14. 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.

  15. Absorption of Bupivacaine after Administration of a Lozenge as Topical Treatment for Pain from Oral Mucositis.

    PubMed

    Mogensen, Stine; Sverrisdóttir, Eva; Sveinsdóttir, Kolbrún; Treldal, Charlotte; Jensen, Kenneth; Jensen, Anders Bonde; Kristensen, Claus Andrup; Jacobsen, Jette; Kreilgaard, Mads; Petersen, Janne; Andersen, Ove

    2017-01-01

    The aim was to investigate systemic exposure after administration of a novel bupivacaine lozenge in healthy individuals with normal mucosa and in head and neck cancer (HNC) patients with oral mucositis. A lozenge containing 5, 10, 25 and 50 mg bupivacaine, respectively, was administered as single dose to 10 healthy individuals, and a lozenge containing 25 mg bupivacaine was administered as single dose to 10 HNC patients with oral mucositis and as multiple doses to five patients with HNC. Blood samples were collected for 6 hr from the healthy individuals and 3 hr from the patients with HNC, respectively, after administration. The plasma concentration-time profiles of bupivacaine were fitted to pharmacokinetic models using nonlinear mixed-effects modelling, evaluating demographics and health status as covariates. The population pharmacokinetics (PK) of bupivacaine lozenge was best described by a two-compartment distribution model with absorption transit compartments. All the observed plasma concentrations were well below the bupivacaine concentrations (2000-2250 ng/ml) which have caused toxic symptoms. The PK model suggested that relative bioavailability was two times higher in HNC patients with oral mucositis grade 1-2 and three times higher in HNC patients with oral mucositis grade 3-4 than in the healthy individuals. Simulations showed that the plasma concentrations would be below the toxic limit after repeated dosing every second hour with 25 mg bupivacaine for five days. The 25-mg bupivacaine lozenges were safe without systemic toxic levels of bupivacaine or risk of side effects. Based on PK simulations of repeated doses of 25 mg every two hours for 16 hr a day, the lozenges can be administered with minimum risk of exceeding the toxic limit.

  16. Induction of Influenza-Specific Mucosal Immunity by an Attenuated Recombinant Sendai Virus

    PubMed Central

    Le, Thuc-vy L.; Mironova, Elena; Garcin, Dominique; Compans, Richard W.

    2011-01-01

    Background Many pathogens initiate infection at the mucosal surfaces; therefore, induction of mucosal immune responses is a first level of defense against infection and is the most powerful means of protection. Although intramuscular injection is widely used for vaccination and is effective at inducing circulating antibodies, it is less effective at inducing mucosal antibodies. Methodology/Principal Findings Here we report a novel recombinant, attenuated Sendai virus vector (GP42-H1) in which the hemagglutinin (HA) gene of influenza A virus was introduced into the Sendai virus genome as an additional gene. Infection of CV-1 cells by GP42-H1 resulted in cell surface expression of the HA protein. Intranasal immunization of mice with 1,000 plaque forming units (pfu) of GP42-H1 induced HA-specific IgG and IgA antibodies in the blood, brochoalveolar lavage fluid, fecal pellet extracts and saliva. The HA-specific antibody titer induced by GP42-H1 closely resembles the titer induced by sublethal infection by live influenza virus; however, in contrast to infection by influenza virus, immunization with GP42-H1 did not result in disease symptoms or the loss of body weight. In mice that were immunized with GP42-H1 and then challenged with 5LD50 (1250 pfu) of influenza virus, no significant weight loss was observed and other visual signs of morbidity were not detected. Conclusions These results demonstrate that the GP42-H1 Sendai virus recombinant is able to confer full protection from lethal infection by influenza virus, supporting the conclusion that it is a safe and effective mucosal vaccine vector. PMID:21533151

  17. Retinal research using the perfused mammalian eye.

    PubMed

    Niemeyer, G

    2001-05-01

    The effort to isolate and maintain alive in vitro an intact mammalian eye is rewarded by the full control provided over the arterial input and exclusion of systemic regulatory or compensatory mechanisms. Electrical recording of typical light-evoked field potentials from retina and optic nerve can be complemented by single-cell recording. Thus, light-induced electrical activity reflects the function of the retinal pigment epithelium, of the layers of the retina and of the ganglion cells or their axons. Retinal function in vitro is documented by electrophysiological and morphological methods revealing subtle features of retinal information processing as well as optic nerve signals that approach-at threshold stimulus intensity-the human psychophysical threshold. Such sensitivity of third-order retinal neurons is described for the first time. This well controlled in vitro preparation has been used successfully for biophysical, metabolic and pharmacological studies. Examples are provided that demonstrate the marked sensibility of the rod system to changes in glucose supply. Moreover, histochemical identification of glycogen stores revealed labeling of the second- and third-order neurons subserving the rod system, in addition to labeling of Müller (glial) cells in the cat retina. The glycogen content of the cat retina is augmented by prolonged anesthesia, largely depleted by ischemia after enucleation and enhanced by insulin. Pharmacological experiments using agonists and antagonists of putative retinal neurotransmitters are summarized and outlined using the muscarinic cholinergic agonist QNB as an example. Actions and uptake of the neuromodulator adenosine are presented in detail, including inhibitory effects on physiologically characterized ganglion cells. Neuronal effects of adenosine are distinguished from those resulting from vasodilatation and from glycogenolysis induced by the neuromodulator. To open the blood-retina barrier, a hyperosmotic challenge can be

  18. Dissociative Part-Dependent Resting-State Activity in Dissociative Identity Disorder: A Controlled fMRI Perfusion Study

    PubMed Central

    Schlumpf, Yolanda R.; Reinders, Antje A. T. S.; Nijenhuis, Ellert R. S.; Luechinger, Roger; van Osch, Matthias J. P.; Jäncke, Lutz

    2014-01-01

    Background In accordance with the Theory of Structural Dissociation of the Personality (TSDP), studies of dissociative identity disorder (DID) have documented that two prototypical dissociative subsystems of the personality, the “Emotional Part” (EP) and the “Apparently Normal Part” (ANP), have different biopsychosocial reactions to supraliminal and subliminal trauma-related cues and that these reactions cannot be mimicked by fantasy prone healthy controls nor by actors. Methods Arterial spin labeling perfusion MRI was used to test the hypotheses that ANP and EP in DID have different perfusion patterns in response to rest instructions, and that perfusion is different in actors who were instructed to simulate ANP and EP. In a follow-up study, regional cerebral blood flow of DID patients was compared with the activation pattern of healthy non-simulating controls. Results Compared to EP, ANP showed elevated perfusion in bilateral thalamus. Compared to ANP, EP had increased perfusion in the dorsomedial prefrontal cortex, primary somatosensory cortex, and motor-related areas. Perfusion patterns for simulated ANP and EP were different. Fitting their reported role-play strategies, the actors activated brain structures involved in visual mental imagery and empathizing feelings. The follow-up study demonstrated elevated perfusion in the left temporal lobe in DID patients, whereas non-simulating healthy controls had increased activity in areas which mediate the mental construction of past and future episodic events. Conclusion DID involves dissociative part-dependent resting-state differences. Compared to ANP, EP activated brain structures involved in self-referencing and sensorimotor actions more. Actors had different perfusion patterns compared to genuine ANP and EP. Comparisons of neural activity for individuals with DID and non-DID simulating controls suggest that the resting-state features of ANP and EP in DID are not due to imagination. The findings are

  19. Assessing the adequacy of myocardial perfusion in man: anatomic and functional techniques

    SciTech Connect

    Miller, S.W.; Boucher, C.A.

    1985-12-01

    The dynamic nature of the coronary vasculature and its stenoses frequently requires more than a subjective anatomic visualization to evaluate potential myocardial ischemia. Although coronary arteriography can assess stenoses of no hemodynamic importance (less than 20 per cent diameter reduction) and lesions that severely impair blood flow (greater than 80 per cent diameter reduction). Most coronary stenoses fall between these two extremes. Quantitative arteriography and radioisotope perfusion studies can improve the accuracy of predicting myocardial ischemia.

  20. Computed tomography perfusion and computed tomography angiography for prediction of clinical outcomes in ischemic stroke patients after thrombolysis

    PubMed Central

    Pan, Jia-wei; Yu, Xiang-rong; Zhou, Shu-yi; Wang, Jian-hong; Zhang, Jun; Geng, Dao-ying; Zhang, Tian-yu; Cheng, Xin; Ling, Yi-feng; Dong, Qiang

    2017-01-01

    Cerebral blood perfusion and cerebrovascular lesions are important factors that can affect the therapeutic efficacy of thrombolysis. At present, the majority of studies focus on assessing the accuracy of lesion location using imaging methods before treatment, with less attention to predictions of outcomes after thrombolysis. Thus, in the present study, we assessed the efficacy of combined computed tomography (CT) perfusion and CT angiography in predicting clinical outcomes after thrombolysis in ischemic stroke patients. The study included 52 patients who received both CT perfusion and CT angiography. Patients were grouped based on the following criteria to compare clinical outcomes: (1) thrombolytic and non-thrombolytic patients, (2) thrombolytic patients with CT angiography showing the presence or absence of a vascular stenosis, (3) thrombolytic patients with CT perfusion showing the presence or absence of hemodynamic mismatch, and (4) different CT angiography and CT perfusion results. Short-term outcome was assessed by the 24-hour National Institution of Health Stroke Scale score change. Long-term outcome was assessed by the 3-month modified Rankin Scale score. Of 52 ischemic stroke patients, 29 were treated with thrombolysis and exhibited improved short-term outcomes compared with those without thrombolysis treatment (23 patients). Patients with both vascular stenosis and blood flow mismatch (13 patients) exhibited the best short-term outcome, while there was no correlation of long-term outcome with CT angiography or CT perfusion findings. These data suggest that combined CT perfusion and CT angiography are useful for predicting short-term outcome, but not long-term outcome, after thrombolysis. PMID:28250755

  1. Mucosal drug delivery: membranes, methodologies, and applications.

    PubMed

    Song, Yifan; Wang, Yiping; Thakur, Rashmi; Meidan, Victor M; Michniak, Bozena

    2004-01-01

    In recent years, extensive research into novel forms of drug delivery has suggested that mucosal approaches offer a promising therapeutic alternative, especially for systemically acting drugs. Transmucosal drug delivery offers many benefits, including noninvasive administration, convenience, rapid onset, as well as elimination of hepatic first-pass metabolism. The investigated absorptive surfaces consist of the nasal, buccal, ocular, vaginal, and rectal mucosae. Among these, the nasal and buccal routes have proved the most promising to date. The bioavailability achieved mainly depends upon the pathophysiological state of the mucosa and the properties of both the drug and delivery systems. Various agents can increase the efficacy of transmucosal drug delivery. These include cyclodextrins, bile salts, surfactants, fusidic acid derivatives, microspheres, liposomes, and bioadhesive agents. The mechanisms of action, effectiveness, and toxicity profiles of these enhancers have been investigated extensively in both animal and human models.

  2. 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

  3. Mucosal cytokine network in inflammatory bowel disease

    PubMed Central

    Andoh, Akira; Yagi, Yuhki; Shioya, Makoto; Nishida, Atsushi; Tsujikawa, Tomoyuki; Fujiyama, Yoshihide

    2008-01-01

    Inflammatory bowel disease (IBD), ulcerative colitis (UC) and Crohn’s disease (CD) are characterized by ongoing mucosal inflammation in which dysfunction of the host immunologic response against dietary factors and commensal bacteria is involved. The chronic inflammatory process leads to disruption of the epithelial barrier, and the formation of epithelial ulceration. This permits easy access for the luminal microbiota and dietary antigens to cells resident in the lamina propria, and stimulates further pathological immune cell responses. Cytokines are essential mediators of the interactions between activated immune cells and non-immune cells, including epithelial and mesenchymal cells. The clinical efficacy of targeting TNF-α clearly indicates that cytokines are the therapeutic targets in IBD patients. In this manuscript, we focus on the biological activities of recently-reported cytokines [Interleukin (IL)-17 cytokine family, IL-31 and IL-32], which might play a role through interaction with TNF-α in the pathophysiology of IBD. PMID:18777592

  4. Matching of postcontraction perfusion to oxygen consumption across submaximal contraction intensities in exercising humans

    PubMed Central

    Elder, Christopher P.; Donahue, Manus J.; Damon, Bruce M.

    2015-01-01

    Studying the magnitude and kinetics of blood flow, oxygen extraction, and oxygen consumption at exercise onset and during the recovery from exercise can lead to insights into both the normal control of metabolism and blood flow and the disturbances to these processes in metabolic and cardiovascular diseases. The purpose of this study was to examine the on- and off-kinetics for oxygen delivery, extraction, and consumption as functions of submaximal contraction intensity. Eight healthy subjects performed four 1-min isometric dorsiflexion contractions, with two at 20% MVC and two at 40% MVC. During one contraction at each intensity, relative perfusion changes were measured by using arterial spin labeling, and the deoxyhemoglobin percentage (%HHb) was estimated using the spin- and gradient-echo sequence and a previously published empirical calibration. For the whole group, the mean perfusion did not increase during contraction. The %HHb increased from ∼28 to 38% during contractions of each intensity, with kinetics well described by an exponential function and mean response times (MRTs) of 22.7 and 21.6 s for 20 and 40% MVC, respectively. Following contraction, perfusion increased ∼2.5-fold. The %HHb, oxygen consumption, and perfusion returned to precontraction levels with MRTs of 27.5, 46.4, and 50.0 s, respectively (20% MVC), and 29.2, 75.3, and 86.0 s, respectively (40% MVC). These data demonstrate in human subjects the varied recovery rates of perfusion and oxygen consumption, along with the similar rates of %HHb recovery, across these exercise intensities. PMID:26066829

  5. Matching of postcontraction perfusion to oxygen consumption across submaximal contraction intensities in exercising humans.

    PubMed

    Buck, Amanda K W; Elder, Christopher P; Donahue, Manus J; Damon, Bruce M

    2015-08-01

    Studying the magnitude and kinetics of blood flow, oxygen extraction, and oxygen consumption at exercise onset and during the recovery from exercise can lead to insights into both the normal control of metabolism and blood flow and the disturbances to these processes in metabolic and cardiovascular diseases. The purpose of this study was to examine the on- and off-kinetics for oxygen delivery, extraction, and consumption as functions of submaximal contraction intensity. Eight healthy subjects performed four 1-min isometric dorsiflexion contractions, with two at 20% MVC and two at 40% MVC. During one contraction at each intensity, relative perfusion changes were measured by using arterial spin labeling, and the deoxyhemoglobin percentage (%HHb) was estimated using the spin- and gradient-echo sequence and a previously published empirical calibration. For the whole group, the mean perfusion did not increase during contraction. The %HHb increased from ∼28 to 38% during contractions of each intensity, with kinetics well described by an exponential function and mean response times (MRTs) of 22.7 and 21.6 s for 20 and 40% MVC, respectively. Following contraction, perfusion increased ∼2.5-fold. The %HHb, oxygen consumption, and perfusion returned to precontraction levels with MRTs of 27.5, 46.4, and 50.0 s, respectively (20% MVC), and 29.2, 75.3, and 86.0 s, respectively (40% MVC). These data demonstrate in human subjects the varied recovery rates of perfusion and oxygen consumption, along with the similar rates of %HHb recovery, across these exercise intensities.

  6. Isolat